DE10332825A1 - Motor vehicle internal combustion engine valve timing control has variable valve timing and adjustable exhaust valve opening with respect to crankshaft - Google Patents

Abstract

The motor vehicle internal combustion engine control has ECU control, for a variable valve timing drive (30,31) which uses a pump power parameter to define the operating upper and lower ranges. The ECU can also control a variable valve timing limiter control (130) which controls the outlet valve opening with respect to the crank angle. The valve opening can be varied on the ignition and exhaust strokes.

Description

The present invention relates to a control device for an internal combustion engine.

In the past few years, one increased number of vehicles and internal combustion engines with a device for variable valve timing, which is a valve timing amount any intake valve and / or exhaust valve, such as one Valve timing, a stroke amount, an angle of action (valve opening duration) varied.

In general, such Variable valve control device a target control amount of the intake valve and / or the exhaust valve based on the control motor operating state using an illustration or selected and becomes the actual valve timing amount of the intake valve and / or the exhaust valve controlled such that it matches its target valve control amount to the target performance to achieve the internal combustion engine.

For example, in the state with extremely low load, the valve opening timing (valve opening time) the intake valve is controlled to match a target valve opening position the one at a delayed Side of the top dead center of the intake stroke, so that a corresponding piston is in a cylinder before opening the Intake valve at the intake stroke moves down to the cylinder pressure decrease a negative value. That way at the time the valve opening of the intake valve increases the flow rate of the intake air by the flow characteristics to improve the gas mixture in the cylinder so that the combustion is stabilized in the cylinder. Furthermore, at the time the low load by introducing the valve opening timing of the intake valve to the target valve opening position, the nearby top dead center of the intake stroke is set, a decrease (Amount of negative pressure) decreased in the cylinder pressure at the intake stroke, thereby improving fuel consumption. such Control gears are, for example, in Japanese Unexamined Patent Publication No. 2001-263105 disclosed.

However, in the above device for variable valve timing, the actual valve timing amount of the intake valve and / or the exhaust valve controlled such that it matches the target valve control amount to the target performance to achieve the internal combustion engine. So if a mistake regarding a measurement of a sensor (such as a stroke sensor, one actual Stroke amount) becomes relatively large or if there is an error regarding a learned value of a reference position (e.g. the most delayed Angle position of valve timing) of the valve timing amount becomes relatively large can be the actual valve timing amount cannot be controlled exactly so that it matches the target valve control amount. For one In such a case, the target performance of the internal combustion engine cannot be achieved. If further in the case where the sensor to measure the actual Valve control amount is used, the sensor malfunction is subject to variable valve control operation carried out become.

Another valve timing control device for an internal combustion engine is disclosed, for example, in Japanese Unexamined Patent Publication No. 5-118232. This laid-open publication discloses a technique for achieving both the reduction in fuel consumption (improvement in fuel consumption) and a reduction in NO _x (nitrogen oxide) without providing exhaust gas recirculation (EGR) on the internal combustion engine.

In this publication, by controlling the opening / closing timing of an intake valve and the opening / closing timing of an exhaust valve, the fuel consumption in the medium to high fuel range is improved while obtaining the required target residual exhaust gas flow rate, particularly the required target flow rate of the internal EGR, that is required to reduce the NO _x in the entire load range. However, in the above technique, fuel combustion is deteriorated by increasing the flow rate of the internal EGR in the low load range of the internal combustion engine. As a result, fuel consumption cannot be improved and emissions can be worsened.

The present invention is based on addressed the above disadvantages. So it's a job of the present invention, a control device for an internal combustion engine to be able to provide a valve timing amount of at least one of an intake valve and an exhaust valve to steer to an appropriate corresponding value that allows that a target performance the internal combustion engine is achieved.

It is another object of the present invention to provide a control device for an internal combustion engine, which is able to reduce fuel consumption without that deterioration in fuel consumption in the low load range the corresponding internal combustion engine is caused.

The above tasks to solve the present invention, is a control device for an internal combustion engine is provided which has a variable valve mechanism having a valve timing amount of at least either an intake valve or an exhaust valve of the internal combustion engine changes. The Control device has a cylinder pressure measuring device, a pumping loss calculation device and a pump loss control device. The cylinder pressure measuring device is for measuring or estimating a cylinder pressure in at least one cylinder of the internal combustion engine intended. The pump loss calculation device is for calculation of a pumping loss or a pumping loss parameter of the internal combustion engine provided based on a cylinder pressure of the cylinder, which is measured or set by the cylinder pressure device. At this point, the pumping loss parameter correlates with the pumping loss point. The pump loss control device is for controlling the variable Valve mechanism provided such that the pumping loss parameter essentially coincides with a corresponding, predetermined target value.

To the tasks of the present To solve invention a control device for an internal combustion engine is also provided. The control device has a control mechanism for a variable Valve timing, a crank angle measuring device and a Crank angle calculation device. The control mechanism for the variable valve timing varies at least either a valve opening time or a valve closing time an exhaust valve of the internal combustion engine. The crank angle measuring device is provided for measuring a crank angle of the internal combustion engine. The crank angle calculator is for calculating one first crank angle or a second crank angle of the crankshaft as a target crank angle based on at least one operating parameter of the Internal combustion engine provided. Here is the first crank angle Crank angle in which a pressure of a combustion chamber of the internal combustion engine at a combustion cycle of the internal combustion engine to a level slight holds above a negative pressure range. Likewise, the second crank angle at which the pressure of the combustion chamber is essentially at ambient pressure in a subsequent exhaust stroke of the internal combustion engine after the Falling pressure of the combustion chamber in a negative pressure range restored at the combustion stroke of the internal combustion engine becomes. The valve timing controller is up to Control the control mechanism of the variable valve timing provided such that a valve opening crank angle of the crankshaft, which is measured by the crank angle measuring device and at which the outlet valve is open at the time the valve opens, essentially coincides with the target crank angle, which is calculated by the crank angle calculation device.

To achieve the object of the present invention to solve, a control device for an internal combustion engine is also provided. The control device has a control mechanism variable valve timing, a crank angle measuring device, a combustion chamber pressure measuring device and a valve timing control device on. The control device of the variable valve timing varies at least one of a valve opening time and a valve closing time Exhaust valve of the internal combustion engine. The crank angle measuring device is for measuring a crank angle of a crankshaft of the internal combustion engine intended. The combustion chamber pressure measuring device is for direct measurement a pressure of a combustion chamber of the combustion mode. The valve timing control device is for controlling the control mechanism the variable valve timing is provided such that the valve opening time the exhaust valve with either a first time or a second time coincides which are detected by the combustion chamber pressure measuring device. Here The first time is a time when the pressure of the combustion chamber in a combustion cycle of the internal combustion engine in a negative Print area falls. Likewise, the second time is a time when the pressure the combustion chamber to an ambient pressure at a following exhaust stroke of the internal combustion engine after the Pressure of the combustion chamber in the negative pressure range in the combustion cycle the internal combustion engine is restored.

The invention is shared with additional Tasks, features, and their benefits best from the following Description, the attached claims and the associated Understand drawings.

1 10 is a schematic view of an engine control system according to a first embodiment of the present invention;

2 Fig. 4 is a front view of a variable intake valve lift mechanism;

3 Fig. 12 is a schematic view showing operation of the variable intake valve lift mechanism in a large lift mode;

4 Fig. 11 is a schematic view showing operation of the variable intake valve lift mechanism in a small lift mode;

5 Fig. 12 is a valve lift characteristic view showing successive changes in the valve lift amount by the variable intake valve lift mechanism shows;

6 Fig. 14 is a flowchart showing a pump loss control basic routine according to the first embodiment;

7 Fig. 11 is a schematic view showing a map of an intake valve lift shift amount ΔVVLin;

8th FIG. 12 is a schematic view showing a map of intake valve timing advance angle ΔVVTin;

9 Fig. 11 is a schematic view showing a map of an exhaust valve lift shift amount ΔVVLex;

10 Fig. 11 is a schematic view showing an illustration of an exhaust valve timing advance angle ΔVVTex;

11 Fig. 12 is a graph of individual characteristics showing the manner of correcting a valve lift amount of an intake valve, a valve lift amount of an exhaust valve, and a timing;

12 Fig. 14 is a flowchart showing an actual pumping loss calculation routine according to the first embodiment;

13 Fig. 12 is a pressure indicator diagram exemplifying a relationship between the cylinder pressure C and the cylinder volume V for describing a way of calculating the actual pumping loss according to the first embodiment;

14 Fig. 14 is a flowchart showing a target pumping loss calculation routine according to the first embodiment;

15 Figure 12 is a schematic diagram showing a target pump loss TGINLOSS;

16 Fig. 12 is a timing chart showing an exemplary pumping loss control amount according to the first embodiment;

17 Fig. 14 is a flowchart showing an actual pumping loss calculation routine according to a second embodiment;

18 Fig. 12 is a pressure indicator diagram exemplifying a relationship between the cylinder pressure CP and the cylinder volume V for describing a way to calculate the actual pumping loss according to the second embodiment;

19 12 is a schematic view showing an internal combustion engine having an internal combustion engine valve timing control device according to a third embodiment of the present invention;

20 Fig. 12 is a characteristic diagram showing changes in the pressure of a combustion chamber in a low load area of the internal combustion engine;

21 Fig. 12 is a partially enlarged diagram showing an area A of 20 shows;

22 Fig. 12 is a characteristic diagram showing changes in the pressure of the combustion chamber in the medium to high load range of the internal combustion engine;

23 FIG. 12 is a flowchart showing advance control operation performed by an ECU through a variable valve timing control mechanism in the engine valve timing control device according to the third embodiment;

24 FIG. 11 is a flowchart showing a deceleration control operation performed by the ECU through the variable valve timing control mechanism in the engine valve timing control device according to the third embodiment;

25 12 is a schematic view showing an internal combustion engine having an internal combustion engine valve timing control device according to a fourth embodiment of the present invention;

26 FIG. 12 is a flowchart showing advance control operation performed by an ECU through a variable valve timing control mechanism in the engine valve timing control device according to the fourth embodiment;

27 FIG. 12 is a flowchart showing a deceleration control operation performed by the ECU through the variable valve timing control mechanism in the engine valve timing device according to the fourth embodiment, and FIG

28 FIG. 12 is a characteristic diagram showing a relationship between a valve opening time and a fuel consumption, which indicates a decrease in fuel consumption in an advance control operation and a deceleration control operation according to the third embodiment and the fourth embodiment.

(First embodiment)

A first embodiment of the present invention will be described with reference to FIG 1 to 16 described. First, an engine control system of the present embodiment is shown schematically with reference to FIG 1 described. An air purifier 13 is at an upstream end of an inlet pipe 12 an internal combustion engine (internal combustion engine 11 ) arranged. An air flow meter 14 is downstream of the air purifier 13 arranged to measure an amount of intake air (hereinafter referred to as "intake air flow rate"). A throttle valve 15 and a throttle valve position sensor 16 are downstream of the air flow meter 14 arranged. A degree of opening (valve position) of the throttle valve 15 is, for example, by a direct current motor (DC motor) posed. The throttle valve position sensor 16 measures the degree of opening of the throttle valve 15 ,

There is also an expansion tank 17 downstream of the throttle valve 15 arranged. An inlet pipe pressure sensor 18 is at the expansion tank 17 provided to a pressure (hereinafter referred to as an "intake pipe pressure") within the intake pipe 12 to eat. An intake manifold 19 is with the expansion tank 17 connected to the air each cylinder 43 of the internal combustion engine 11 supply. A fuel injector 20 is at an intake port of the intake manifold 19 from each cylinder 43 intended for injecting fuel. There are also spark plugs 21 on a cylinder head of the internal combustion engine 11 arranged so that each spark plug 21 on the corresponding one of the cylinders 43 is provided to a gas mixture in the corresponding one of the cylinders 43 to ignite by a spark discharge.

A variable intake valve lift mechanism 30 is on the intake valves 28 of the internal combustion engine 11 for varying an amount of valve lift (hereinafter referred to as "a valve lift amount") of the intake valves 28 and a variable exhaust valve lift mechanism 31 is on the exhaust valves 29 of the internal combustion engine 11 for varying a valve lift amount of the exhaust valves 29 intended. Furthermore, there is a variable intake valve timing mechanism (not shown) on the intake valves 28 to vary a valve timing (an opening timing and a closing timing) of the intake valves 28 intended. There is also a variable exhaust valve timing mechanism (not shown) on the exhaust valves 28 to vary valve timing (opening timing and closing timing) of the exhaust valves 29 intended.

A catalytic converter 23 , such as a three-way catalytic converter, is in an exhaust pipe 22 of the internal combustion engine 11 used to reduce emissions, such as CO, HC, NO _x , in the exhaust gases. An exhaust gas sensor (for example, an air-fuel ratio sensor or an oxygen sensor) 24 is upstream of the catalytic converter 23 arranged to measure an air-fuel ratio of the exhaust gas or a rich / lean condition of the exhaust gas. A coolant temperature sensor 25 and a crank angle sensor 26 are on the cylinder block of the internal combustion engine 11 arranged. The coolant temperature sensor 25 measures the coolant temperature. The crank angle sensor 26 outputs a pulse signal only when the crankshaft of the internal combustion engine 11 rotates through a predetermined crank angle (e.g., 30 degrees crank angle). The crank angle and the engine speed are determined based on the output signal of the crank angle sensor 26 determined.

Furthermore, at least one of the cylinders 23 of the internal combustion engine 11 a cylinder pressure sensor (cylinder pressure measuring device) 42 for measuring the pressure inside the cylinder 43 provided (hereinafter referred to as a "cylinder pressure" or a "displayed pressure"). Alternatively, the spark plug 21 from at least one of the cylinders 43 be replaced by a spark plug which has a cylinder pressure sensor.

Outputs from various sensors described above become an engine control circuit (hereinafter referred to as an "ECU") 27 fed. The ECU 27 has a microcomputer as its main component. The ECU 27 controls a fuel injection amount from each fuel injection valve 20 and an ignition timing of each spark plug 21 based on the current engine operating condition when executing various engine control programs stored in an internal ROM (storage medium).

The structure of the variable intake valve lift mechanism 30 is with reference to the Fig. 2 described. The structure of the variable exhaust valve lift mechanism 31 is substantially the same as that of the variable intake valve lift mechanism 30 and is therefore not described for simplification.

With reference to 2 is a link lever 34 between a rocker arm 33 and a camshaft 32 arranged the corresponding inlet valve 28 drives. A tax wave 35 by an engine 43 , such as a stepper motor, is above the link lever 34 arranged. An eccentric cam 36 is rotatable in one piece with the control shaft 35 connected. The link lever 34 is pivotally or tiltably supported by a support shaft, not shown, at a point which is eccentric to the axis of rotation of the eccentric cam 36 is. A toggle cam 38 is at the center of the link lever 34 provided, and a side surface of the tilt cam 38 is engaged with an outer peripheral surface of a cam 37 that on the camshaft 32 is provided. A pressure cam 39 is at a lower end of the link lever 34 intended. A lower end surface of the pressure cam 39 is engaged with an upper end face of a roller 40 that are in the middle of the rocker arm 33 is arranged.

If with the construction of the cams described above 37 by the rotation of the camshaft 32 is rotated, the toggle cam follows 38 of the link lever 34 the outer peripheral surface of the cam 37 and moves accordingly to the left and to the right so that the entire link lever 34 in 2 tilts left and right. If the link lever 34 tilts left and right, the pressure cam moves 39 left and right. So the role moves 40 of rocker 33 in a vertical direction in 2 up and down in that it is the lower end face of the pressure cam 39 follows, and the rocker arm swings 33 thus in the vertical direction or tilts in the same. Due to the rocking motion of the rocker arm 33 the inlet valve moves 28 up and down.

If the eccentric cam 36 by the rotation of the control valves 35 is rotated, the position of the support shaft of the link lever 34 emotional. Thus an output contact point varies ( 3 and 4 ) between the pressure cam 39 and the link lever 34 and the role 40 the rocker arm 33 , As in 2 shown further has the lower end surface of the pressure cam 39 of the link lever 34 a curved base surface 39a on the left side of the lower end surface of the pressure cam 39 on. The curved base surface 39a has a curvature that is an amount of depression of the rocker arm 33 equals 0 (especially the valve lift amount of the intake valve 28 makes 0). The lower end surface of the pressure cam 39 also has a curved printing surface 39b on that has a curvature, the increasing changes in the amount of depression of the rocker arm 33 from the curved base end face 39a towards right in 2 caused (especially increasing changes in the valve lift amount of the intake valve 28 caused).

3 Fig. 14 shows a large lift mode of the variable intake valve lift mechanism 30 at which the valve lift amount of the intake valve 28 is relatively large. In the operating mode with a large stroke, the output contact point between the pressure cam 39 of the link lever 34 and the role 40 the rocker arm 33 in the right direction in 3 by turning the control shaft 35 postponed. In this way, an engagement area of the lower end surface of the pressure cam becomes 39 that with the role 40 engages when the pressure cam 39 left and right by turning the cam 39 is moved in the right direction from 3 postponed. Thus, a maximum amount of depression of the rocker arm 33 increases so that the maximum valve lift amount of the intake valve 28 is increased, and becomes a depressing period during which the rocker arm 33 is depressed, increased accordingly by a valve opening period of the intake valve 28 to increase.

On the other hand, in a low lift mode in which the valve lift amount intake valve 28 is relatively small, the output contact point between the pressure cam 39 of the link lever 34 and the role 40 the rocker arm 33 by the rotation of the control shaft 35 in the left direction in 4 postponed. In this way, the engagement area of the lower end surface of the pressure cam 39 with the role 40 engages when the pressure cam 39 left and right by turning the cam 37 is moved, moved in the left direction. Thus, the maximum amount of depression of the rocker arm 33 reduced so that the maximum valve lift amount of the intake valve 38 is decreased, and becomes the depression period during which the rocker arm 33 is depressed, accordingly, reduced by a valve opening period of the intake valve 28 to reduce.

With the variable intake valve lift mechanism 30 , as in 5 both the maximum valve lift amount and the valve opening period (hereinafter simply referred to as a "valve lift amount") of the intake valves 28 of all cylinders 43 successively by turning the control shaft 35 by the engine 41 can be varied to the output contact point between the pressure cam 39 of the link lever 34 and the role 40 the rocker arm 33 to postpone.

The ECU 27 successively changes the valve lift amount of each intake valve 28 to control the intake air flow rate by controlling the variable intake valve lift mechanism 30 based on, for example, accelerator pedal position or engine operating condition when executing a variable valve timing program (not shown) stored in the ROM. In a system included in the variable intake valve lift mechanism 30 and a variable intake valve timing mechanism, the intake air flow rate can be controlled by successively changing both the valve lift amount and the valve timing.

The ECU 27 any corresponding pumping loss control routine (described below) leads to calculating an actual intake pumping loss INLOSS ( 13 ) and an actual exhaust pump loss EXLOSS ( 13 ) based on the cylinder pressure CP (displayed pressure) by the cylinder pressure sensor 42 is measured. The actual intake pump loss (INLOSS) occurs at the intake stroke of the internal combustion engine 11 and the actual exhaust pumping loss (EXLOSS) occurs from a last part of the exhaust stroke to a first part of the exhaust stroke of the engine 11 on. The valve lift amount VVLin and the valve timing VVTin of the intake valve 28 are corrected such that the actual inlet pumping loss INLOSS essentially coincides with a target inlet pumping loss (predetermined target value) TGINLOSS. Likewise, the valve lift amount VVLex and the valve timing VVTex of the exhaust valve 29 corrected such that the actual outlet pumping loss EXLOSS essentially coincides with a target outlet pumping loss (predetermined target value) TGEXLOSS.

Each routine of the pumping loss control operation of the first embodiment executed by the ECU 27 is described in more detail ben.

(Pumping loss control routine basis)

A pump loss control base routine that is in 6 is performed periodically upon turning on an ignition switch (not shown) and serves as a pump loss control device of the present invention. When the pump loss control basic routine is initiated, it is first determined whether the variable valve timing operation is currently at step 101 is carried out. If it is determined that the variable valve timing operation is not currently at step 101 is performed, the present routine ends.

On the other hand, if it is determined that the variable valve timing operation is currently at step 101 control is passed to step 102 further. At step 102 the cylinder pressure CP, through the cylinder pressure sensor 42 is measured, read. Then at step 102 an actual pumping loss calculation routine (described below) of 12 is performed to calculate the actual intake pumping loss INLOSS that occurs on the intake stroke to calculate the actual exhaust pumping loss EXLOSS that occurs from the expansion stroke to the exhaust stroke.

The control then proceeds to step 104 further. At step 104 becomes a target pumping loss calculation routine (described below by 14 ) to calculate the target inlet pumping loss TGINLOSS and the target outlet pumping loss TGEXLOSS. Then at step 105 a deviation ΔINLOSS between the actual inlet pumping loss INLOSS and the target inlet pumping loss TGINLOSS and a deviation ΔEXLOSS between the actual outlet pumping loss EXLOSS and the target outlet pumping loss TGEXLOSS calculated by the following equations:
ΔINLOSS = INLOSS - TGINLOSS
ΔEXLOSS = EXLOSS - TGEXLOSS

Control next goes to step 106 further. At step 106 becomes an illustration of 7 which points to a corresponding required shift amount (hereinafter referred to as an "intake valve shift amount" ΔVVLin from the intake valve lift amount VVLin to obtain the intake valve lift shift amount ΔVVLin which corresponds to the deviation ΔINLOSS between the current actual intake pumping loss INLOSS and the target intake pumping loss TGINLOSS. Then, the intake valve lift amount VVLin is corrected based on the intake valve lift shift amount ΔVVLin by the following equation:
VVLin = VVLin + ΔVVLin

Here is the illustration of 7 showing the intake valve lift shift amount ΔVVLin is constructed as follows. If the deviation ΔINLOSS between the actual intake pump loss INLOSS and the target intake loss TGINLOSS is 0, the intake valve lift displacement amount DVVLin becomes 0. If the deviation ΔINLOSS of 0 is further increased, the intake valve lift displacement amount ΔVVLin is increased. Also, when the deviation ΔINLOSS is reduced, the intake valve lift shift amount ΔVVLin is reduced below 0.

Control next goes to step 107 further. At step 107 becomes an illustration of 8th , which shows a required advance angle ΔVVTin (hereinafter referred to as an "intake valve timing advance angle") from the intake valve timing VVTin, to obtain the intake valve timing advance angle ΔVVTin which corresponds to the deviation ΔINLOSS between the current actual intake pumping loss INLOSS and the TGLOSSpump. Then, the intake valve timing VVTin is corrected based on the intake valve timing advance angle ΔVVTin by the following equation:
VVTin = VVTin + ΔVVTin

Here is the illustration of 8th that shows the intake valve timing advance angle ΔVVTin is constructed as follows. If the deviation ΔINLOSS between the actual intake pumping loss INLOSS and the target intake pumping loss TGINLOSS is 0, the intake valve timing advance angle ΔVVTin becomes 0. Furthermore, if the deviation ΔINLOSS of 0 is increased, the intake valve timing advance angle ΔVVTin is increased. Likewise, if the deviation ΔINLOSS is reduced from 0, the intake valve timing advance angle ΔVVTin is reduced below 0.

Then control goes to step 108 further. At step 108 becomes an illustration of 9 , which shows a corresponding required shift amount (hereinafter referred to as an "exhaust valve lift shift amount") ΔVVLex from the exhaust valve lift amount VVLx, to obtain the exhaust valve lift shift amount ΔVVLex which corresponds to the deviation ΔEXLOSS between the current actual exhaust pumping loss EXLOSS and the exhaust pumping loss TGEXLO. Then, the exhaust valve lift amount VVLex is corrected based on the exhaust valve lift shift amount ΔVVLex by the following equation:
VVLex = VVLex + ΔVVLex

Here is the illustration of 9 showing the exhaust valve lift shift amount ΔVVLex is constructed as follows. If the deviation ΔEXLOSS between the actual exhaust point loss EXLOSS and the target exhaust point loss TGEXLOSS is less than or equal to 0, the exhaust valve lift displacement amount ΔVVLex becomes 0. Furthermore, when the deviation ΔEXLOSS is increased from 0, the exhaust valve lift displacement amount ΔVVLex is decreased below 0. Control next goes to step 109 further. At step 109 becomes an illustration of 10 , which shows a required advance angle ΔVVTex (hereinafter referred to as an "exhaust valve timing advance angle") from the exhaust valve timing VVTex, to obtain the exhaust valve timing advance angle ΔVVTex, which corresponds to the deviation ΔEXLOSS between the current actual exhaust pump loss EXLOSS T and the target exhaust point loss. Then, the exhaust valve timing of the VVTex is corrected based on the exhaust valve timing advance angle ΔVVTex by the following equation:
VVTex = VVTex + ΔVVTex

Here is the illustration of 10 that shows the exhaust valve timing advance angle ΔVVTex is constructed as follows. If the deviation ΔEXLOSS between the actual exhaust point loss EXLOSS and the target exhaust pump loss TGEXLOSS is less than or equal to 0, the exhaust valve timing advance angle ΔVVTex becomes 0. If the deviation ΔEXLOSS of 0 is further increased, the exhaust valve timing advance angle ΔVVTex is reduced below 0.

If so, as in 11 As shown, the deviation ΔINLOSS is increased from 0 (in particular, when the actual intake pumping loss of the INLOSS is increased relative to the target intake pumping loss TGINLOSS), the intake valve lift amount VVLin is increased and the intake valve timing of the VVTin is presented (in particular, the valve opening timing of the intake valve is presented 29 presented. In this way, a decrease (amount of negative pressure) in the cylinder CP during the intake stroke is reduced, so that a size of a negative pressure area ( 13 ), where each cylinder pressure CP is negative relative to the exhaust pressure and which is forward in and around the intake stroke, to reduce the actual intake pumping loss INLOSS.

On the other hand, if the deviation ΔINLOSS is reduced below 0 (especially when the actual intake pumping loss INLOSS is reduced relative to the target intake pumping loss TGINLOSS), the intake valve lift amount VVLin is decreased and the intake valve timing VVTin is delayed (in particular, the valve opening timing of the intake valve 28 ) Is delayed.

In this way, a decrease (amount of a negative pressure) of the cylinder pressure CP during the intake stroke is increased, so that the size of the negative pressure area ( 13 ) at which each cylinder pressure CP is negative relative to the exhaust pressure and which is present in and around the intake stroke is increased to increase the actual intake pumping loss INLOSS.

Furthermore, if the deviation ΔEXLOSS is increased from 0 (in particular, if the actual exhaust pumping loss EXLOSS is increased relative to the target exhaust pumping loss TGEXLOSS), the exhaust valve lift amount VVLex is decreased and the exhaust valve timing VVTex is delayed (in particular, the valve timing of the exhaust valve 29 ) Is delayed. In this way, the cylinder pressure CP is reduced during the outlet part of the exhaust stroke, so that the size of the negative pressure area ( 13 ) at which each cylinder pressure CP is negative relative to the exhaust pressure and which exists between the last part of the expansion stroke and the first part of the exhaust stroke, to reduce the actual exhaust pumping loss EXLOSS.

(Calculation routine of the actual Pumping loss)

A calculation routine of the actual pumping loss, which in 12 is a subroutine as in step 103 of 6 called and executed. The actual pumping loss calculation routine serves as a pumping loss calculator of the present invention.

When the actual pumping loss calculation routine is initiated, a current crank angle is determined based on the output signal of the crank angle sensor 26 is determined at step 201 read. Then control goes to step 202 further. At step 202 a cylinder pressure CP (θ), which corresponds to the current crank angle θ, is read in, and a cylinder volume V (θ), which corresponds to the current crank angle θ, is calculated and read (in particular stored).

The control then proceeds to step 203 further. At step 203 A crank angle θ1 of the compression stroke and a crank angle θ2 of the exhaust stroke are described in the manner described below with reference to FIG 13 obtained, which shows a pressure indicator diagram (PV diagram) indicating a relationship between the cylinder pressure C and the cylinder volume V.

Here, the crank angle θ1 is as one Defines crank angle that is present when a line of the displaying Pressure of the compression stroke a line of the displayed pressure of the Exhaust stroke cuts. The crank angle θ2 is as a crank angle defined that exists when the line of the displayed pressure of the exhaust stroke is the line of the displayed pressure of the compression stroke cuts.

The crank angle θ1 and the crank angle θ2 that meet the following two conditions are obtained as follows:
the cylinder pressure CP (θ1) measured in the compression stroke is equal to the cylinder pressure CP (θ2) measured at the exhaust stroke and
the cylinder volume V (θ1) measured on the compression stroke equals the cylinder volume V (θ2) measured on the exhaust stroke.

The control then proceeds to step 204 further. At step 204 the cylinder pressures CP (θ) measured between the crank angle θ2 and the crank angle θ1 are summed, and the size of the negative pressure area where the cylinder pressure CP is negative relative to the exhaust pressure, the exhaust pressure is substantially equal to the ambient pressure) and which is present in and around the compression stroke is obtained and used as the actual inlet pumping loss INLOSS (pumping loss parameter), which is expressed as follows:

However, it should be noted that to that Time of the reduction in the cylinder volume V (in particular at Time of the exhaust stroke and at the time of the compression stroke) the cylinder pressures CP as negative values are summed (especially CP - CP). The real one INLOSS inlet pumping loss is obtained as an absolute value (positive Value).

The control then proceeds to step 205 further. At step 205 it is determined whether the crank angle gives θ3, θ4, which are respectively measured on the expansion stroke and are measured on the exhaust stroke and meet the following two conditions:
the cylinder pressure CP (θ3) measured on the expansion stroke is equal to the cylinder pressure CP (θ4) measured on the exhaust stroke, and
the cylinder volume V (θ3) measured at the expansion stroke is equal to the cylinder volume V (θ4) measured at the exhaust stroke.

In this way, it is determined whether the line of the displayed pressure of the expansion stroke and the line of the displayed pressure of the exhaust stroke are in the pressure indicator diagram of FIG 13 cut, which shows the relationship between the cylinder pressure CP and the cylinder volume V.

When it is determined that there are crank angles θ3, θ4 (especially when it is determined that the line of the displayed pressure of the expansion stroke and the line of the displayed pressure of the exhaust stroke intersect) at step 205 , the control proceeds to step 206 further. At step 206 the cylinder pressures CP (θ) measured between the crank angle θ3 and the crank angle θ4 are summed up and become a dimension of the negative pressure area at each cylinder pressure CP relative to the exhaust pressure and which is negative between the last part of the expansion stroke and the first part of the exhaust stroke is obtained and is expressed as the actual exhaust pumping loss EXLOSS, which is expressed as follows:

However, it should be noted that the Time of reduction in cylinder volume V (especially at that Time of the exhaust stroke), the cylinder pressures CP are summed as negative values (CP = - CP applies in particular). The real one Outlet pumping loss EXLOSS is obtained as an absolute value (more positive Value).

(Nominal pumping loss calculation routine)

A target pumping loss calculation routine that is in 14 is a subroutine shown in step 104 of 6 called and executed. When the target pumping loss calculation routine is initiated, for example, an engine speed NE and an intake air flow rate GA become the engine operating state information at step 301 read.

The control then proceeds to step 302 further.

At step 302 The target intake pumping loss TGINLOSS, which corresponds to the current engine operating condition (in particular, the engine speed NE and the intake air flow rate GA), is obtained by searching a map of the target intake pumping loss TGINLOSS, which is shown in FIG 15 is shown. In the illustration of the target inlet pump loss TGINLOSS, which in 15 is shown, the target intake pumping loss TGINLOSS is set or selected to minimize the actual intake pumping loss INLOSS within an allowable range that is allowed in the current engine operating condition.

Then control goes to step 303 further. At step 303 the target outlet pumping loss TGEXLOSS is set to 0.

An example of the pumping loss control operation of the first embodiment is described with reference to a timing chart of FIG 16 described.

The actual intake pump loss INLOSS and the actual exhaust pump loss EXLOSS become every cycle (every 720 degrees crank angle) of the internal combustion engine 11 calculated based on the cylinder pressures CP by the cylinder pressure sensor 42 be measured.

The intake valve lift amount VVLin and the intake valve timing VVTin are calculated based on the deviation ΔINLOSS between the actual intake pump loss INLOSS and the Corrected target inlet pumping loss TGINLOSS to bring the actual inlet pumping loss INLOSS closer to the target inlet pumping loss TGINLOSS. Furthermore, the exhaust valve lift amount VVLex and the exhaust valve timing VVTex are corrected based on the deviation ΔEXLOSS between the exhaust pump loss EXLOSS and the target exhaust pump loss TGEXLOSS to approximate the actual exhaust pump loss EXLOSS to the target exhaust pump loss TGEXLOSS.

As described above, the first embodiment is based on the fact that the engine performance is dependent on the pumping loss of the engine 11 varied. Thus, in the first embodiment, the valve control amount (valve lift amount and valve timing) from the intake valve 28 and from each exhaust valve 29 corrected such that the actual intake pumping loss INLOSS and the actual exhausting pumping loss EXLOSS obtained based on the cylinder pressures CP coincide with the target intake pumping loss TGINLOSS and the target exhaust pumping loss TGEXLOSS, respectively. Thus, the valve timing amount of each intake valve 28 and from each exhaust valve 29 are controlled such that the pumping loss of the internal combustion engine 11 is set so that the target performance of the internal combustion engine 11 is achieved. Therefore, even if a measurement error of the stroke sensor that measures the actual stroke amount or an error in a learned value of the most retarded angular position of the valve timing becomes relatively large, the valve timing amount of each intake valve becomes 28 and from each exhaust valve 29 controlled so that they correspond to an appropriate value, which allows the target performance of the internal combustion engine 11 is achieved.

Furthermore, the cylinder pressure sensor is in the first exemplary embodiment 42 on at least the cylinder 43 of the internal combustion engine 11 provided so that the actual cylinder pressure CP is exactly the same as the cylinder pressure 42 can be measured. As a result, the accuracy of the actual intake pumping loss INLOSS and the actual exhausting pumping loss EXLOSS calculated based on the measured cylinder pressures CP can be improved.

Likewise, in the pressure indicator diagram of the first embodiment, which is the relationship between the cylinder pressure CP and the cylinder volume V shows the size of the vacuum area, in which each cylinder pressure CP is negative relative to the outlet pressure and that is present in and around the intake stroke than the actual one INLOSS inlet pumping loss calculated. Furthermore, the vacuum area, in which each cylinder pressure CP is negative relative to the outlet pressure between the last part of the expansion stroke and the first part of the exhaust stroke is present as an actual exhaust pump loss EXLOSS is calculated. As a result, the actual intake pumping loss INLOSS and the actual Outlet pumping losses are calculated to be relatively accurate across the whole Return the amount of the pumping loss.

Furthermore, in the first embodiment, the target intake pumping loss TGINLOSS is set or selected to minimize the actual intake pumping loss INLOSS within the allowable range that is allowed in the engine operating state. Thus, the actual intake pumping loss INLOSS can be minimized to improve fuel consumption while maintaining the proper operating condition without adversely affecting the operation of the internal combustion engine 11 caused.

In the first embodiment, when the actual intake pumping loss INLOSS is controlled, the valve timing amount of the intake valve becomes 28 varied. Furthermore, when the actual exhaust pumping loss is controlled EXLOSS, the valve control amount of the exhaust valve becomes 29 varied. Thus, the actual inlet pumping loss INLOSS and the actual outlet pumping loss EXLOSS can be controlled independently and the actual outlet pumping loss INLOSS and the actual outlet pumping loss EXLOSS can be controlled relatively accurately to the target inlet pumping loss TGINLOSS and the target outlet pumping loss TGEXLOSS, respectively.

(Second embodiment)

In the first embodiment the size of the vacuum area, in which each cylinder pressure CP is negative relative to the outlet pressure and is present in and around the intake stroke than the actual one INLOSS inlet pumping loss calculated (pumping loss parameter).

In the second embodiment, which in the 17 and 18 is shown, a difference between the exhaust pressure and the cylinder pressure CP at a predetermined crank angle (hereinafter referred to as a "target valve opening position θtg of the intake valve 28 "referred to) calculated in the intake stroke as the actual intake pump loss INLOSS (pump loss parameter).

(Calculation routine of the actual Pumping loss)

At the in 17 of the actual pumping loss calculation routine shown in the second embodiment becomes a target valve opening position θtg of the intake valve 28 at step 401 read. Then control goes to step 402 further, at which a crank angle θ5 ( 18 ) is calculated. The crank angle θ5 is defined as a crank angle that is present in the exhaust stroke if the following condition is met:
the cylinder pressure V (θtg) at the target valve opening position θtg of the intake valve 28 equal to the cylinder pressure V (θ5) on the exhaust stroke.

The control then proceeds to step 403 further. At step 403 becomes the difference between the cylinder pressure CP (θ5) at the crank angle θ5 at the exhaust stroke and the cylinder pressure CP (θtg) at the target valve opening position θtg of the intake valve 28 calculated at the intake stroke and as the actual intake pump loss INLOSS ( 18 ), which is expressed as follows:
INLOSS = CP (θ5) - CP (θtg)

Furthermore, in the second embodiment the target inlet pumping loss TGINLOSS set or selected to the actual INLOSS inlet pumping loss greater or equal to a predetermined value.

As described above, in the second embodiment, the difference between the exhaust pressure and the cylinder pressure CP at the predetermined crank angle (specifically, the target valve opening position θtg of the intake valve 28 ) calculated as the actual inlet pumping loss INLOSS. Thus, a computational load imposed by the ECU 27 for calculating the actual intake pumping loss INLOSS is reduced compared to the case where the size of the negative pressure area in which the cylinder pressure CP is negative relative to the exhaust pressure is calculated as the actual intake pumping loss INLOSS.

Further, in the second embodiment, the target intake pumping loss TGINLOSS is set or selected to be the actual intake pumping loss INLOSS, particularly the difference between the exhaust pressure and the cylinder pressure CP (θtg) at the target valve opening position θtg of the intake valve 28 greater than or equal to the predetermined value. Thus, a flow rate of intake air at the time of opening the intake valve 28 be increased to include the flow characteristics of the fuel mixture in the cylinder 43 to improve fuel stabilization.

However, in the second embodiment the target inlet pump loss TGINLOSS can be set or selected, the actual inlet pumping loss INLOSS (the difference between the outlet pressure and the cylinder pressure CP at the predetermined crank angle) minimal or relatively small within the allowable Make range that in the operating state of the internal combustion engine permissible is.

In the first embodiment the target inlet pumping loss TGINLOSS can be set or selected, to the actual INLOSS inlet pumping loss (the size of the vacuum area, at which each cylinder pressure CP is negative relative to the outlet pressure is bigger than or to make the same as the predetermined value.

In each of the first embodiment and the second embodiment, the target pumping loss can be set or selected to be the actual pumping loss at the time of deceleration of the engine 11 to increase. In this way, the engine braking performance at the time of deceleration of the engine 11 can be improved by increasing the pumping loss. Furthermore, at the time of the deceleration engine, it tends 11 the intake air flow rate to decrease, causing deterioration in fuel consumption. However, increasing the pumping loss stabilizes fuel combustion. Thus, the drivability can be improved and the stopping of the internal combustion engine can be restricted.

In each of the first embodiment and the second embodiment, the cylinder pressure is detected by the cylinder pressure sensor 42 measured. Alternatively, the cylinder pressure may be based on the valve timing amount (valve lift amount and valve timing) of the intake valve 28 and the exhaust valve 29 , the pressure in the intake pipe and / or the intake air flow rate can be estimated.

In each of the first embodiment and the second embodiment, the present invention is carried out in the system that includes the variable intake valve lift mechanism 30 , the variable exhaust valve lift mechanism 31 , the variable intake valve timing mechanism and the variable exhaust valve timing mechanism all include. However, the present invention may be implemented in a system that includes at least one of the variable intake valve lift mechanism 30 , from the variable exhaust valve lift mechanism 31 , of the variable intake valve timing mechanism and the variable exhaust valve timing mechanism.

In each of the first embodiment and the second embodiment The present invention is implemented in a system that the intake air flow rate through the variable intake valve control operation controls. However, the present invention can be carried out in a system the intake air flow rate by a throttle valve control operation controls.

(Third embodiment)

19 FIG. 12 shows an internal combustion engine having an internal combustion engine valve timing control device (or simply referred to as a control device) according to a third embodiment of the present invention.

With reference to 19 is an inlet passage (inlet pipe) 111 with the power machine 110 connected. An air purifier 112 , an air flow meter 113 , a throttle valve 114 , an intake air temperature sensor 116 and an injector (fuel injector) 118 are in this order in a flow direction of the intake air in the intake passage 111 arranged. The air purifier 112 removes foreign matter and dust from the intake air in the intake air passage 111 , The air flow meter 113 measures the intake air flow rate QA. The throttle valve 114 controls the intake air flow rate QA. The intake air temperature sensor 116 measures the temperature (hereinafter referred to as the intake air temperature) THA of the intake air through an expansion tank 115 stepped through, restricting sudden increases in intake air. The injector 118 injects fuel to an appropriate inlet port 117 on. According to an opening / closing timing of the intake valve 119 becomes a fuel mixture, which is a mixture of air coming from the intake passage 111 is supplied and the fuel is from the injector 118 is fed through the inlet port 117 into a combustion chamber 122 performed between a cylinder block 120 and a corresponding piston 121 the internal combustion engine 110 is defined. The fuel mixture that the combustion chamber 122 is supplied, is spark ignition of the fuel mixture by a spark plug 123 burned and thereupon becomes an outlet passage (outlet pipe) 126 through an outlet port 125 based on an opening / closing timing of an exhaust valve 124 pushed out.

A variable valve timing control mechanism 130 which is an electromagnetic actuator 131 that is capable of opening / closing timing (an opening timing and a closing timing) of the exhaust valve 124 is to vary with the outlet valve 124 of the present embodiment. Furthermore, the variable valve timing control mechanism 130 a valve lift sensor 132 the valve lift amount VL of the exhaust valve 124 measures. The internal combustion engine 110 also has a crank angle sensor 128 on a crank angle CA, in particular an angle of rotation of a crankshaft, 127 measures.

The intake air flow rate QA of the air flow meter 113 , the intake air temperature THA of the intake air temperature sensor 116 , the valve lift amount VL of the valve lift sensor 132 and the crank angle CA of the crank angle sensor 128 become an electronic control unit (ECU) 114 fed. The ECU 140 is constructed as a logical operating circuit comprising a CPU, ROM, RAM, backup RAM, input / output circuit and bus lines. The CPU serves as a central process unit that performs various arithmetic calculations. The ROM stores control programs and control maps. The RAM stores various data. The ECU 140 gives various control signals, such as a control signal for the injector 118 to indicate the fuel injection amount TAU, a control signal to the spark plug 123 for indicating the ignition timing Ig and a valve drive signal VD of the exhaust valve 124 to the electromagnetic actuator 131 from.

Next, changes in pressure P from the combustion chamber 122 with respect to the valve opening durations of the intake valve 119 and the exhaust valve 124 with reference to the 20-22 described. It shows 20 a characteristic diagram, the changes in the pressure P of the combustion chamber 122 in the low load range of the internal combustion engine 110 displays. 21 shows a partially enlarged diagram showing a region A of 20 shows. For comparison shows 22 a characteristic diagram, the changes in the pressure P of the combustion chamber 122 in the medium to high load range of the internal combustion engine 110 shows.

As in 22 shown changes in the medium to high load range of the internal combustion engine 110 the pressure P of the combustion chamber 122 with reference to the crank angle (degrees CA or degrees KW), which is the angle of rotation of the crankshaft 127 the internal combustion engine 110 is, as is indicated by a solid, bold line. That means that in the medium to high load range of the internal combustion engine 110 the pressure P of the combustion chamber 122 is never reduced to a negative pressure range below the ambient pressure at the combustion stroke and the exhaust stroke or after the top dead center (TDC or OT).

On the other hand, as in the 20 and 21 shown changes in the low load range of the internal combustion engine 110 the pressure P of the combustion chamber 122 with respect to the crank angle (degree CA or degree KW) in a way that is indicated by a solid, bold line. That is, in the low load range of the internal combustion engine 110 there is a vacuum period during which the pressure P of the combustion chamber 122 is reduced below the vacuum, in the combustion cycle or after TDC or OT. At the valve opening period of the standard control operation during the vacuum period, the exhaust valve is 124 placed in an open state. Thus, a pumping loss occurs as an outlet loss at the time of burning the burned gas from the combustion chamber 122 on what a deterioration in fuel consumption in the low load range of the internal combustion engine 110 caused.

Thus, in the present embodiment, eliminating the pumping loss, which is an exhaust loss in the low load area of the internal combustion engine 110 occurs, the variable valve time voting mechanism 130 , the valve opening timing (valve opening timing) in the valve opening period of the exhaust valve 124 changes to change the behavior of the pressure P of the combustion chamber 122 used, which is observed during the standard control (in particular the normal control) and by the bold, solid line in 21 is indicated, by an advance control operation or a delay control operation. That is, by the advance control operation, an "STD point" representing the valve opening timing in the valve opening period of the exhaust valve 124 in the standard control mode, an "S point" (imagined angle) is introduced at which the pressure P of the combustion chamber 122 falls to a level slightly above the vacuum range at the combustion stroke, as by a solid, dotted line in 21 is indicated. Furthermore, the deceleration control operation becomes the valve opening timing in the valve opening period of the exhaust valve 124 to a "T-point" (delayed angle) at which the pressure P of the combustion chamber 122 is essentially restored to the ambient pressure in the following exhaust stroke after the pressure P of the combustion chamber 122 falls into the negative pressure range at the previous combustion stroke, as by a bold chain line in 21 is indicated.

The advance control operation by the ECU 140 through the variable valve timing control mechanism 130 in the engine valve timing control mechanism 130 in the engine valve timing control device according to the third embodiment of the present invention will be described with reference to a flowchart of FIG 23 in connection with the 21 and 22 described. This advance control routine is carried out by the ECU 140 repeated at predetermined time intervals.

In 23 will step first 1101 the intake air flow rate QA (g / sec) through the air flow meter 113 read. Control next goes to step 1102 further. At step 1102 the intake air temperature THA (degrees Celsius) through the intake air temperature sensor 116 read. Then control goes to step 1103 further. At step 1103 the engine speed NE (rpm) is determined on the basis of the crank angle CA or KW, which is determined by the crank angle sensor 128 is received and read. Then control goes to step 1104 further. At step 1104 becomes the fuel injection amount TAU, which corresponds to the current operating state of the internal combustion engine 110 corresponds, calculated. The control then proceeds to step 1105 further. At step 1105 becomes the ignition timing (ignition timing) Ig, which is the current operating state of the internal combustion engine 110 corresponds, calculated.

Then control goes to step 1106 further. At step 1106 becomes the pressure P of the combustion chamber 122 at the combustion stroke of the internal combustion engine 110 calculated based on various operating parameters such as the intake air flow rate QA, the intake air temperature THA, the fuel injection amount TAU, the ignition timing Ig. Likewise, the crank angle (first crank angle) at which the pressure P of the combustion chamber 122 falls to a level slightly above the negative pressure range, in particular to the ambient pressure in the combustion cycle of the internal combustion engine 110 falls, calculated as the target crank angle TGCA. Then control goes to step 1107 further. At step 1107 it is determined whether the pressure P of the combustion chamber 122 at the combustion stroke of the internal combustion engine 110 becomes negative. If the answer to the request at step 1107 "NO" is when, in particular, the pressure P of the combustion chamber 122 not with the combustion stroke of the internal combustion engine 110 In other words, the operating state of the internal combustion engine becomes negative 110 is in a medium to high load range, the control proceeds to step 1108 further. At step 1108 is the standard control operation of the crank angle (valve opening crank angle) CA or KW, at which the exhaust valve 124 at the valve opening time in the valve opening period of the exhaust valve 124 is opened, controlled so that it coincides with the "STD point" that is in 22 is shown and the current routine ends.

On the other hand, if the answer to the request at step 1107 "YES" is when, in particular, the operating state of the internal combustion engine 110 is in the low load range by the pressure P of the combustion chamber 122 at the combustion stroke of the internal combustion engine 110 If the control becomes negative, the control proceeds to step 1109 further. At step 1109 becomes the valve drive signal VD, which is the valve opening timing of the exhaust valve 124 so that it agrees with the target crank angle TGCA that at step 1106 is calculated, issued. Control next goes to step 1110 further. At step 1110 becomes the current valve lift amount VL of the exhaust valve 124 through the valve lift sensor 132 read. This valve lift amount VL by the valve lift sensor 132 is obtained to detect an abnormality in the opening / closing timing of the exhaust valve 124 and / or an abnormality of the valve lift amount VL of the exhaust valve 124 used.

Control next goes to step 1111 further. At step 111 the current crank angle CA or KW by the crank angle sensor 128 read. Then control goes to step 1112 further. At step 1112 it is determined whether the exhaust valve 124 is open at the target crank angle TGCA at the time of valve opening. If the answer to the request at step 1112 "YES" is, in particular, if the target crank angle TCA, that at step 1106 is calculated, coincides with the current crank angle CA or KW, which at step 1111 is read, it is determined that the exhaust valve 124 at the appropriate opening time, the current routine is opened and ended without modifying the valve drive signal VD.

On the other hand, if the answer to the request at step 1112 "NO" is, if in particular the target crank angle TGCA, that at step 1106 is calculated, does not match the current crank angle CA or KW, which at step 1111 the controller goes to step 1113 further. At step 1113 it is determined whether the current crank angle (valve opening crank angle) CA or KW at which the exhaust valve 124 at the valve opening time in the valve opening period of the exhaust valve 124 is opened, is located on the advance side of the target crank angle TGCA, in particular whether the crank angle (valve opening crank angle) CA or KW is earlier than the target crank angle TGCA. If the answer to the request at step 1113 "YES" if, in particular, the current crank angle CA or KW at which the exhaust valve 124 at the valve opening timing of the exhaust valve 124 is open, is located on the advance side of the target crank angle TGCA, the control proceeds to step 1114 further. At step 1114 the valve drive signal VD is delayed for delaying the crank angle CA or KW by a predetermined angle and the current routine ends.

On the other hand, if the answer to the request at step 1113 "NO" is when, in particular, the current crank angle (valve crank angle) CA or KW at which the exhaust valve 124 at the valve opening timing of the exhaust valve 124 is open, is located on the deceleration side of the target crank angle TGCA, the control proceeds to step 1115 further. At step 1115 the valve drive signal VD is advanced by a predetermined angular amount to advance the crank angle CA or KW and the current routine ends. Through the advance control routine described above, the crank angle (valve opening crank angle) CA or KW at which the exhaust valve 124 at the valve opening time of the exhaust valve 124 is opened on the "S point" in 21 placed; in particular, it coincides with the target crank angle TGCA.

As described above, the engine valve timing control device of the previous embodiment has the variable valve timing control mechanism 130 , the crank angle sensor 128 and the ECU 140 serving as a crank angle calculator and a valve timing controller. The valve timing control mechanism 130 can adjust the opening / closing timing (the opening time and the closing time) of the exhaust valve 124 the internal combustion engine 110 to change. The crank angle sensor 128 serves as a crank angle measuring device for measuring or detecting the crank angle CA or KW, which is the angle of rotation of the crankshaft 127 the internal combustion engine 110 is. The crank angle calculation device is provided for calculating the crank angle (first crank angle) at which the pressure P of the combustion chamber 122 to a level slightly above the negative pressure range in the combustion cycle of the internal combustion engine 110 falls as the target crank angle TGCA based on the various operating parameters. The valve timing control device is for controlling the variable valve timing control mechanism 130 such that the crank angle (valve opening crank angle) CA or KW by the crank angle sensor 128 is measured, and in which the exhaust valve 124 is opened at the time the valve opens, essentially coincides with the desired crank angle TGCA, which is calculated by the crank angle calculation device. Furthermore, the engine timing control device uses the load of the engine 110 (the load is determined based on the intake air flow rate QA or the intake air pressure) and the engine speed NE as an operating parameter.

That is, the crank angle (first crank angle) at which the pressure P of the combustion chamber 122 to the level slightly above the negative pressure range in the combustion cycle of the internal combustion engine 110 falls as the target crank angle TGCA based on the load of the internal combustion engine 110 (wherein the load is calculated based on the intake air flow rate QA or the intake air pressure) and the engine speed NE. Then the variable valve timing control mechanism 130 controlled such that the crank angle (valve opening crank angle) CA or KW at which the exhaust valve 124 at the valve opening timing of the exhaust valve 124 is opened, essentially corresponds to the calculated target crank angle TGCA. In this way, the pressure P of the combustion chamber is prevented 122 in the low load range of the internal combustion engine 110 falls in the negative pressure range. Thus, the pumping loss, which is the exhaust gas loss or the exhaust loss, can be eliminated. As a result, the deterioration of the combustion is restricted in the low load range of the internal combustion engine, and thus the fuel consumption is reduced.

Next is the delay control operation by the ECU 140 through the variable valve timing control mechanism 130 is performed on the engine valve timing control apparatus according to the third embodiment of the present invention, with reference to a flowchart of FIG 24 combined with 21 described. This deceleration control routine is carried out by the ECU 140 repeated at predetermined time intervals.

With reference to 24 are the steps 1201-1205 . 1207 . 1208 . 1210-1215 essentially the same as the steps 1101-1105 . 1107 . 1108 . 1110-1115 and are therefore not described further.

At step 1206 becomes the pressure P of the combustion chamber 122 at the combustion stroke of the internal combustion engine 110 calculated based on the various operating parameters such as the intake air flow rate QA, the intake air temperature THA, the fuel injection amount TAU, ignition timing Ig. Likewise, the crank angle (second crank angle) at which the pressure P of the combustion chamber 122 essentially on the ambient pressure at the exhaust stroke of the internal combustion engine 110 is restored after the pressure P of the combustion chamber 122 in the negative pressure range in the previous combustion cycle of the internal combustion engine 110 fell, calculated as the target crank angle TGCA. Next is at step 1209 the valve drive signal VD, which is the valve opening timing of the exhaust valve 124 sets so that it matches the target crank angle TGCA, which at step 1206 is calculated, issued. Through the deceleration control routine described above, the crank angle (valve opening crank angle) CA or KW at which the exhaust valve falls 124 at the valve opening time in the valve opening period of the exhaust valve 124 is opened, together with the target crank angle TGCR, in particular on the "T-point" in 21 set.

As described above, the engine valve timing control device of the present embodiment has the variable valve timing control mechanism 130 , the crank angle sensor 128 and the ECU 140 serving as a crank angle calculator and a valve timing controller. The valve timing control mechanism 130 can adjust the opening / closing timing (the opening time and the closing time) of the exhaust valve 124 the internal combustion engine 110 to change. The crank angle sensor 128 serves as a crank angle measuring device for measuring or for detecting the crank angle CA or KW, which is the angle of rotation of the crankshaft 127 the internal combustion engine 110 is. The crank angle calculation device is provided for calculating the crank angle (second crank angle) at which the pressure P of the combustion chamber 122 essentially on the ambient pressure at the exhaust stroke of the internal combustion engine 110 is restored after the pressure P of the combustion chamber 122 in the negative pressure range during the combustion cycle of the internal combustion engine 110 falls as the target crank angle TGCA based on the various operating parameters. The valve timing control device is for controlling the variable valve timing control mechanism 130 , such that the crank angle (valve opening crank angle) CA or KW by the crank angle sensor 128 is measured and in which the exhaust valve 124 at the valve opening time of the exhaust valve 124 is opened, essentially coincides with the desired crank angle TGCA, which is calculated by the crank angle calculation device. Furthermore, the engine valve timing control device of the present embodiment uses the load of the engine 110 (the load is determined based on the intake air flow rate QA or the intake air pressure) and the engine speed NE as an operating parameter.

That is, the crank angle (second crank angle) at which the pressure P of the combustion chamber 122 is essentially restored to the ambient pressure at the exhaust stroke after the pressure P of the combustion chamber 122 has fallen into the negative pressure range in the preceding combustion cycle, as the target crank angle TGCA based on the load of the internal combustion engine 110 (the load is determined based on the intake air flow rate QA or the intake air pressure) and the engine speed NE is calculated. Then the variable valve timing control mechanism 130 controlled such that the crank angle (valve opening crank angle) CA or KW at which the exhaust valve 124 at the valve opening time of the exhaust valve 124 is opened, essentially corresponds to the calculated target crank angle TGCA. In this way, the low load range of the internal combustion engine 110 the valve opening time of the exhaust valve 124 placed out of the vacuum period during which the pressure P of the combustion chamber 122 is in the vacuum range. Thus, the pumping loss, which is the outlet loss, can be eliminated. As a result, the deterioration of the combustion is restricted in the low load range of the internal combustion engine, and thus the fuel consumption is reduced.

Fourth Embodiment

25 FIG. 12 shows an internal combustion engine having an internal combustion engine valve timing control device according to a fourth embodiment of the present invention. In In the fourth embodiment, components that are similar to those in the third embodiment are designated by the same reference numerals and will not be described further.

In the present embodiment, as in 25 is shown is a cylinder pressure sensor 129 on a side wall of the cylinder block 120 the internal combustion engine 110 arranged and is in the combustion chamber 122 placed. Furthermore, the air flow meter 113 and the intake air temperature sensor 116 of the third embodiment, which in 19 from the inlet passage 111 away. That is, in the present embodiment, the pressure P of the combustion chamber 122 directly through the cylinder pressure sensor 129 can be measured so that it is not necessary the pressure P of the combustion chamber 122 based on the operating parameters such as the intake air flow rate QA by the air flow meter 113 is detected, and the intake air temperature THA by the intake air temperature sensor 116 is obtained to calculate.

The advance control operation by the ECU 140 through the variable valve timing control mechanism 130 in the engine valve timing control apparatus according to the fourth embodiment of the present invention will be described with reference to a flowchart of FIG 26 in Fig. with 21 described. This advance control routine is carried out by the ECU 140 repeated at predetermined time intervals.

With reference to 26 will at step 1301 the current crank angle CA or KW by the crank angle sensor 128 read. Control next goes to step 1302 further. At step 1302 it is determined whether the crank angle (valve opening crank angle) CA or KW, which in step 1301 is read, CA or KW is on the advance side of the crank angle (standard value opening crank angle), in particular the "STD point" of 21 where the exhaust valve 124 at the valve opening time of the valve opening period of the exhaust valve 124 in the standard control operation of the exhaust valve 124 located. If the answer to the request at step 1302 "NO" is when it is determined in particular that the crank angle CA or KW is the same as at step 1301 is read, is located on the deceleration side of the crank angle (standard valve opening crank angle) CA or KW, in particular the "STD point" of 21 , the control proceeds to step 1303 further. At step 1303 becomes the exhaust valve 124 is placed in the open state and the current routine is ended.

On the other hand, if the answer to the request at step 1302 Is "YES"; if it is determined in particular that the crank angle CA or KW, which at step 1301 is read, CA or KW is on the advance side of the crank angle (standard valve opening crank angle), in particular the "STD point" of 21 , the control proceeds to step 1304 further. At step 1304 becomes the pressure (cylinder pressure) P of the combustion chamber 122 through the cylinder pressure sensor 129 read. Then control goes to step 1305 further. At step 1305 it is determined whether the cylinder pressure P, which in step 1304 is read in, less than or equal to a reference pressure Pth ( 21 ) is. The reference pressure Pth is taken into consideration in consideration of a response delay from, for example, the variable valve timing control mechanism 130 determined. If the answer to the request from step 1305 "NO" is when, in particular, it is determined that the cylinder pressure P, which at step 1304 is still larger than the reference pressure Pth, the control returns to step 1301 back to repeat the same process.

On the other hand, if the answer to the request at step 1305 "YES" is, in particular, when it is determined that the cylinder pressure P, which at step 1304 is read in, less than or equal to the reference pressure Pth, the control proceeds to step 1306 further. At step 1306 the valve drive signal VD is output such that the exhaust valve 124 is placed in the open state and the routine is ended. Through the advance control routine described above, the crank angle (valve opening crank angle) at which the exhaust valve 124 at the valve opening time of the valve opening period of the exhaust valve 124 is opened, set so that it with the "S point" of 21 matches.

As described above, the engine valve timing control device of the present embodiment has the variable valve timing control mechanism 130 , the crank angle sensor 128 , the cylinder pressure sensor 129 and the ECU 140 that serve as a valve timing control device. The valve timing control mechanism 130 can adjust the opening / closing timing (the opening time and the closing time) of the exhaust valve 124 the internal combustion engine 110 to change. The crank angle sensor 128 serves as a crank angle measuring device for measuring or detecting the crank angle CA or KW, which is the angle of rotation of the crankshaft 127 the internal combustion engine 110 is. The cylinder pressure sensor 129 serves as a combustion chamber pressure measuring device for directly measuring the pressure of the internal combustion, as cylinder pressure P. The valve timing control device is for controlling the variable valve timing control mechanism 130 provided such that the valve opening time of the exhaust valve 124 essentially coincides with the point in time (first point in time) by the cylinder pressure sensor 129 he and where the cylinder pressure P is in the negative pressure range during the combustion cycle of the internal combustion engine 110 falls.

That is, the time (first time) at which the pressure P of the combustion chamber 122 in the negative pressure range at the combustion stroke of the internal combustion engine 110 falls through the cylinder pressure sensor 129 is detected and the variable valve timing control mechanism 130 is controlled such that the valve opening time of the exhaust valve 124 essentially coincides with this point in time (first point in time). In this way the pressure P of the combustion chamber drops 122 in the low load range of the internal combustion engine 110 not in the vacuum area. Thus, the pumping loss, which is the outlet loss, can be eliminated. As a result, the deterioration of combustion is restricted in the low load range of the internal combustion engine, and thus the fuel consumption is reduced.

Next, a deceleration control operation performed by the ECU 140 through the variable valve timing control mechanism 130 is performed on the engine valve timing control apparatus according to the fourth embodiment of the present invention, with reference to a flowchart of FIG 27 combined with 21 described. This deceleration control routine is carried out by the ECU 140 repeated at predetermined time intervals.

With reference to 27 is the current crank angle CA or KW by the crank angle sensor 128 at step 1401 read. Control next goes to step 1402 further. At step 1402 it is determined whether the internal combustion engine 110 in the combustion stroke based on the crank angle CA or KW, which is at step 1401 is read. If the answer to the request at step 1402 "No is; if in particular the internal combustion engine 110 is in the exhaust stroke, control proceeds to step 1403 further. At step 1403 becomes the exhaust valve 124 is placed in the open state and the current routine is ended.

On the other hand, if the answer to the request at step 1402 "YES" is when, in particular, the internal combustion engine 110 is in the combustion stroke, control proceeds to step 1404 further. At step 1404 the cylinder pressure (pressure in the combustion chamber 122 ) P by the cylinder pressure sensor 129 read. Control next goes to step 1405 further. At step 1405 it is determined whether the cylinder pressure P, which in step 1404 is read in, is equal to or less than a reference pressure, such as the ambient pressure. If the answer to the request at step 1405 "No is; if in particular the cylinder pressure P is still above the ambient pressure, control returns to step 1401 back to repeat the same process.

On the other hand, if the answer to the request at step 1405 "YES", in particular, if the cylinder pressure P is equal to or less than the ambient pressure, control goes to step 1406 continue to the exhaust valve 124 in the open state at or after bottom dead center (BDC or UT) from 21 to place. At step 1406 becomes the current crank angle CA by the crank angle sensor 128 read. Then control goes to step 1407 further. At step 1407 it is determined whether the internal combustion engine 110 is in the exhaust stroke, based on the crank angle CA that at step 1406 is read. If the answer to the request at step 1407 "No is; if in particular the internal combustion engine 110 control is still in the combustion stroke, control returns to step 1406 back to repeat the same process.

If there is the answer to the request at step 1407 Is "YES"; if in particular the internal combustion engine 110 is in the exhaust stroke, control proceeds to step 1408 further. At step 1408 is the cylinder pressure P by the cylinder pressure sensor 129 read. Control next goes to step 1409 further. At step 1409 it is determined whether the cylinder pressure P is equal to or greater than the ambient pressure. If the answer to the request at step 1409 If the cylinder pressure P is lower than the ambient pressure (reference pressure), the control returns to step 1408 back to repeat the same process.

On the other hand, if the answer to the request at step 1409 Is "YES"; if, in particular, the cylinder pressure P is equal to or greater than the ambient pressure, the control proceeds to step 1410 further. At step 1410 the valve drive signal VD is output such that the exhaust valve 124 is set in the open state and the current routine is ended. Through the deceleration control routine, the crank angle (valve opening crank angle) CA or KW at which the exhaust valve 124 at the valve opening time of the valve opening period of the exhaust valve 124 is opened, set so that it with the "T point" of 21 matches.

As described above, the engine valve timing control device of the present embodiment has the variable valve timing control mechanism 130 , the crank angle sensor 128 , the cylinder pressure sensor 129 and the ECU 140 serving as a valve timing control device. The valve timing control mechanism 130 can adjust the opening / closing timing (the opening timing and the closing timing) of the exhaust valve 124 the focal combustion engine 110 to change. The crank angle sensor 128 serves as a crank angle measuring device for measuring or detecting the crank angle CA or KW, which is the angle of rotation of the crankshaft 127 the internal combustion engine 110 is. The cylinder pressure sensor 129 serves as a combustion chamber pressure measuring device for directly measuring the pressure of the combustion chamber 122 as cylinder pressure P. The valve timing control means is for controlling the variable valve timing control mechanism 130 provided such that a valve opening time of the exhaust valve 124 essentially coincides with the point in time (second point in time) by the cylinder pressure sensor 129 is detected and at which the pressure P of the combustion chamber 122 essentially on the ambient pressure at the exhaust stroke of the internal combustion engine 110 is restored after the pressure P of the combustion chamber 122 in the negative pressure range in the previous combustion cycle of the internal combustion engine 110 falls.

That is, the time (second time) at which the pressure P of the combustion chamber 122 essentially on the ambient pressure at the exhaust stroke of the internal combustion engine 110 is restored after the pressure P of the combustion chamber 122 in the negative pressure range in the previous combustion cycle of the internal combustion engine 110 fell through the cylinder pressure sensor 129 is recorded. The variable valve timing control mechanism 130 is controlled so that the valve opening timing of the exhaust valve 124 coincides with this time (second time). In this way, the low load range of the internal combustion engine 110 the valve opening time of the exhaust valve 124 placed out of the vacuum period during which the pressure P of the combustion chamber 122 is in the vacuum area. Thus, a pumping loss, which is the outlet loss, can be eliminated. As a result, the deterioration of the combustion is restricted in the low load range of the internal combustion engine, and thus the fuel consumption is reduced.

The advantage of reducing fuel consumption in the above-mentioned embodiments is explained with reference to the characteristic diagram of FIG 28 described the relationship between the valve opening timing in the valve opening period of the exhaust valve 124 and the fuel consumption (g / min). The characteristic diagram of 28 is obtained under the following conditions. The internal combustion engine 110 namely has a total displacement of 1.5 liters with four in series with a compression ratio of ε = 10.5, and the internal combustion engine 110 is operated under the conditions of 1000 (rpm), zero (no load) (Nm) and an oil / water temperature of 80 ° C.

As in 28 is shown by the advance control operation, which introduces the valve opening timing in the valve opening period, in the standard control operation of the exhaust valve 124 is used, the crank angle (degree CA or degree KW) is set to the best position or the best angle ("S-Punkt6" in 21 ). Thus, the fuel consumption can be reduced by 2% compared to the fuel consumption at the "STD point", which is the valve opening timing of the valve opening period in the standard control operation. As in 28 is further shown by the delay control operation that delays the valve opening timing of the valve opening period that in the standard control operation of the exhaust valve 124 is used, the crank angle (degree CA or degree KW) is set to the best deceleration position or the best deceleration angle ("T point" in 21 ). Thus, the fuel consumption can be reduced by 5% compared to the fuel consumption at the "STD point" which is the valve opening timing at the valve opening period in the standard control operation.

In the above-mentioned embodiments is the invention with reference to the control operations of the Exhaust valve of a single cylinder described. The present However, invention is not limited to this. In the event that the internal combustion engine has a plurality of cylinders, control operations similar to those discussed above on each of the cylinders in the same Dimensions are applied to similar benefits to achieve the ones discussed above.

Additional advantages and modifications will be apparent to those skilled in the art. The invention in its more general meaning is therefore not on specific details, limits the illustrative device and explanatory examples that are shown and described.

In one aspect, the ECU controls 27 . 140 a variable valve mechanism 30 . 31 such that a pumping loss parameter essentially coincides with a corresponding, predetermined target value. In another aspect, the ECU 27 . 140 a variable valve timing control mechanism 130 control such that a valve opening crank angle of a crankshaft 127 where an exhaust valve 124 is opened at the time the valve opens, essentially coincides with a desired crank angle. The target crank angle can be one of a first and a second crank angle. The first crank angle is a crank angle at which a pressure of a combustion chamber 122 drops to a level slightly above a negative pressure range in one combustion cycle. The second crank angle is a crank angle at which the pressure of the combustion chamber 122 is essentially restored to an ambient pressure on the following exhaust stroke after the pressure falls into the negative pressure range the combustion cycle has fallen.

Claims (11)

Control device for an internal combustion engine ( 11 ) that have a variable valve mechanism ( 30 . 31 ) that has a valve timing amount of at least one of an intake valve ( 28 ) or an exhaust valve ( 29 ) of the internal combustion engine ( 11 ) changes, characterized in that the control device has the following: a cylinder pressure measuring device ( 43 ) for measuring or estimating a cylinder pressure in at least one cylinder ( 43 ) of the internal combustion engine ( 11 ); a pump loss calculation device ( 201-206 ) to calculate either a pumping loss or a pumping loss parameter of the internal combustion engine ( 11 ) based on a cylinder pressure of the cylinder ( 43 ) by the cylinder pressure measuring device ( 42 ) is measured or estimated, the pumping loss parameter correlating with the pumping loss, and a pumping loss control device ( 101-109 ) to control the variable valve mechanism ( 30 . 31 ) such that the pumping loss parameter essentially coincides with a corresponding, predetermined target value. Control device according to claim 1, characterized in that the cylinder pressure measuring device ( 42 ) a cylinder pressure sensor ( 42 ) that is attached to at least one cylinder ( 43 ) of the internal combustion engine ( 11 ) is provided. Control device according to claim 1 or 2, characterized in that the pumping loss calculation device ( 201-206 ) a size of a negative pressure area of a pressure indicator diagram in which a cylinder pressure of the cylinder ( 43 ) by the cylinder pressure measuring device ( 42 ) is measured or estimated relative to an exhaust pressure is calculated, the pressure indicator diagram showing a relationship between a cylinder pressure of the cylinder ( 43 ) and a cylinder volume of the cylinder ( 43 ) and the pumping loss calculator ( 201-206 ) the size of the vacuum range is calculated as the pumping loss parameter. Control device according to claim 1 or 2, characterized in that the pumping loss calculation device ( 201-206 ) a difference between an exhaust pressure and a cylinder pressure of the cylinder ( 43 ) by the cylinder pressure measuring device ( 42 ) is measured or estimated, calculated at a predetermined crank angle, and wherein the pumping loss calculator ( 201-206 ) the difference is calculated as the pumping loss parameter. Control device according to one of claims 1-4, characterized in that the target value of the pumping loss parameter is selected so that the pumping loss parameter is minimized within a permissible range, which is in an operating state of the internal combustion engine ( 11 ) is permitted. Control device according to one of claims 1 - 4, characterized in that the setpoint of the pumping loss parameter is selected so the pumping loss parameter is equal to or greater than becomes a predetermined value. Control device according to one of claims 1-6, characterized in that the pumping loss control device ( 101-109 ) the valve timing amount of the intake valve ( 28 ) changes when the pumping loss control device ( 101-109 ) controls a pumping loss that occurs on an intake stroke, the pumping loss control device ( 101-109 ) the valve timing amount of the exhaust valve ( 29 ) changes when the pumping loss control device ( 101-109 ) controls a pumping loss that occurs from an expansion stroke to an exhaust stroke. Control device according to one of claims 1-7, characterized in that the target value of the pumping loss parameter is selected so that the pumping loss parameter during a deceleration operation of the internal combustion engine ( 11 ) elevated. Control device for an internal combustion engine ( 110 ), characterized in that the control device comprises: a variable valve timing control mechanism ( 130 ), which at least either a valve opening time or a valve closing time of an exhaust valve ( 124 ) of the internal combustion engine ( 110 ) varies; a crank angle measuring device ( 128 ) for measuring a crank angle of a crankshaft ( 127 ) of the internal combustion engine ( 110 ); a crank angle calculation device ( 140 ) to calculate either a first crank angle or a second crank angle of the crankshaft ( 127 ) as the desired crank angle on the basis of at least one operating parameter of the internal combustion engine ( 110 ), the first crank angle being a crank angle at which a pressure of a combustion chamber ( 122 ) of the internal combustion engine ( 110 ) during a combustion cycle of the internal combustion engine ( 110 ) falls to a level slightly above a vacuum range, and wherein the second crank angle is a crank angle at which the pressure of the combustion chamber ( 122 ) essentially to an ambient pressure in a subsequent exhaust stroke of the internal combustion engine ( 110 ) is restored after the pressure of the combustion chamber ( 122 ) in the vacuum range during the combustion cycle of the internal combustion engine ( 110 ) has fallen; a valve timing control device ( 140 ) to control the variable valve timing control mechanism ( 130 ) such that a valve opening crank angle of the crankshaft ( 127 ) by the crank angle measuring device ( 128 ) is measured and in which the outlet valve ( 124 ) is opened at the time the valve opens, essentially coincides with the target crank angle, which is determined by the crank angle calculation device ( 140 ) is calculated. The control device according to claim 9, wherein the at least one operating parameter comprises at least one of the following: an intake air flow rate from the internal combustion engine ( 110 ); a load of the internal combustion engine ( 110 ) based on an intake air pressure of the internal combustion engine ( 110 ) is determined; an engine speed of the internal combustion engine ( 110 ). Control device for an internal combustion engine ( 110 ), characterized in that the control device comprises: a variable valve timing control mechanism ( 130 ), which has at least either a valve opening time or a valve closing time of an exhaust valve ( 124 ) of the internal combustion engine ( 110 ) varies; a crank angle measuring device ( 128 ) for measuring a crank angle of a crankshaft ( 127 ) of the internal combustion engine ( 110 ); a combustion chamber pressure measuring device ( 129 ) for direct measurement of a combustion chamber pressure ( 122 ) of the internal combustion engine ( 110 ) and a valve timing controller ( 140 ) to control the variable valve timing control mechanism ( 130 ) such that the valve opening time of the exhaust valve ( 124 ) essentially coincides with either a first point in time or a second point in time, which is determined by the combustion chamber pressure measuring device ( 129 ) are recorded, the first point in time being a point in time at which the pressure of the combustion chamber ( 122 ) in a combustion cycle of the internal combustion engine ( 110 ) falls within a vacuum range, and the second point in time is a point in time at which the pressure of the combustion chamber ( 122 ) essentially to the ambient pressure in a subsequent exhaust stroke of the internal combustion engine ( 110 ) is restored after the pressure of the combustion chamber ( 122 ) in the vacuum range in the combustion cycle of the internal combustion engine ( 110 ) has fallen.