JP3021739B2 - Engine output control device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE intake by this invention operating conditions
Switching the operation mode of at least one of the valve and the exhaust valve
The present invention relates to an output control device for an engine having a mechanism for controlling an engine.

[0002]

2. Description of the Related Art A valve train for driving an intake and exhaust valve of an engine is set so as to obtain an optimal valve timing in accordance with an output characteristic required by the engine.

However, the required valve timing differs depending on the operating conditions of the engine. For example, in a low load range, the valve lift and the valve opening period are both small, whereas in a high load range, a large valve lift and the valve opening period are required. Is done. In the case of an engine having a wide range of operating conditions, such as an automobile engine, it is very difficult to determine the valve timing in which operating region, and in any case, it is not possible to achieve optimum matching under all operating conditions.

Therefore, as disclosed in Japanese Patent Application Laid-Open No. 63-167016, a plurality of cams having different cam characteristics (cam profiles) are provided, and the cams are switched according to the operating conditions. There has been proposed a variable valve operating device capable of operating at a timing.

[0005] This is to switch between a low-speed cam having a high torque in a low rotation range and a high-speed cam having a high torque characteristic in a high rotation range according to operating conditions. It is to try to make it. In addition, it has been proposed to provide a fuel efficiency cam having excellent fuel efficiency characteristics in a partial load range to improve fuel efficiency in a partial load range.

[0006]

By the way, when the cam is switched, even if the throttle opening does not change, the intake charging efficiency of the cylinder greatly changes depending on the cam characteristics. The fuel supply amount and the ignition timing are simultaneously changed for all cylinders so that the air-fuel ratio becomes flat before and after the switching and that the maximum torque is obtained after the switching also by the change in the intake charging efficiency.

On the other hand, when the switching operation condition is determined, the cam switching is performed by driving the cam switching actuators of the respective cylinders at the same time. Takes a certain amount of time, and there is also a range in which switching cannot be performed depending on the crank angle. Therefore, cam switching is not always completed in all cylinders at the same time, and is often performed at intervals for each cylinder.

When the switching timing is shifted between the cylinders in this way, there are cylinders in which the changed fuel supply amount or the ignition timing does not match the actual cam state before all the cylinders are switched.

For example, as output cams, two output cams having a characteristic that emphasizes a full-open output (torque) in a low rotational speed region and a high rotational speed region (or a single cam having a characteristic that emphasizes an output in a full rotational speed region) are used. Output cam) and a fuel efficiency cam that emphasizes fuel efficiency in the partial load range, the switching from the fuel efficiency cam to the output cam is performed even after the switching since the intake charging efficiency of the output cam is relatively high. To maintain the same air-fuel ratio, the fuel supply is increased. However, in the cylinder in which the actual cam is in the fuel efficiency cam before switching, the amount of fuel is too large and the air-fuel ratio shifts to the rich side, so that the air-fuel ratio varies among the cylinders and the exhaust composition of the entire cylinder deteriorates. is there.

Further, when the fuel supply amount is the same before and after the switching, it is necessary to switch the ignition timing to the minimum advance value at which the maximum torque can be obtained, that is, the so-called MBT even after the switching to the output cam. Later, the ignition timing must be advanced by the amount that the air-fuel ratio shifts to the lean side to improve the combustion state. However, in the cylinder in which the actual cam is the fuel efficiency cam before switching, combustion proceeds too much due to the advance of the ignition timing, and M
BT or knocking occurs. Conversely, when switching to the fuel-efficient cam, in a cylinder in which the actual cam is the output cam before switching, the ignition timing deviates from the MBT and the maximum torque cannot be obtained.

[0011] Such a problem is caused only by switching the cam.
Not all valves of a specific cylinder
Operation can be selectively stopped or cylinder operation can be stopped.
It also occurs in such things as stopping. The present invention is, in synchronism with the cylinder in the actual valve operating mode switching timing, by changing to suit the fuel supply amount and the ignition timing to a valve operation mode after switching, for each cylinder valve
An object of the present invention is to provide a device that prevents a cylinder in which required fuel or ignition timing does not match an actual valve operation mode even when operation mode switching is performed at different timings. And

Therefore, the first invention, as shown in FIG.
A plurality of valve operation modes 1 having different output characteristics, and means 2 for determining selection / switching of the valve operation mode according to the operation state
And at least one of the intake valve or exhaust valve is selected
In engines with a switching mechanism 3 for switching the valve operating mode, and means for determining 4 the timing is switched with the valve operation mode in each cylinder, the valve operating mode in synchronism with the switching timing, valve operation after switching to each cylinder Dynamics
And means 5 for changing the fuel supply amount or the ignition timing corresponding as.

A second aspect of the present invention, as shown in Figure 2, a plurality of valve operating mode 1 having different output characteristics, a means 2 determines selection and switching of the valve operation mode according to the operating state, intake
A valve selected for at least one of a pneumatic valve and an exhaust valve
In an engine provided with a switching mechanism 3 for switching to an operation mode , means 4 for determining the timing at which the valve operation mode is switched for each cylinder, and a shift in intake charging efficiency before and after the switching in synchronization with the valve operation mode switching timing. Means 6 for changing the fuel supply amount corresponding to the valve operation mode after switching for each cylinder in accordance with

As shown in FIG. 3, the third invention comprises a plurality of valve operating modes 1 having different output characteristics, and means 2 for determining selection / switching of the valve operating mode according to the operating state.
At least one of the intake valve and the exhaust valve is
In engines with a switching mechanism for switching the blanking operation mode, means for determining the timing is switched with the valve operation mode in each cylinder, in synchronization with the valve operation mode switching timing, the deviation of intake air charging efficiency after before switching Accordingly, a means 7 for changing the fuel supply amount and the ignition timing corresponding to the valve operation mode after switching for each cylinder is provided.

[0015]

According to the first aspect, the valve is operated according to the operating state.
When the mode switching is commanded, the actual switching timing of the valve operating mode is determined for each cylinder, and one of the fuel and ignition timing is changed for each cylinder according to the switching timing.

[0016] Therefore, even when the switching timing of the valve operation mode is performed at intervals between the cylinders, the mismatch between the required fuel or ignition timing and the actual state of the valve operation mode is reliably avoided.

According to the second aspect of the present invention, the required air-fuel ratio is obtained by changing the efficiency of charging the fresh air into the cylinder even under the same rotational speed and suction negative pressure with the switching of the valve operation mode. However, when the fuel supply amount is changed in accordance with the difference between the intake charging efficiency before and after the switching, the fuel corresponding to the intake charging efficiency after the switching is given, and the fuel and valve operation are performed. air-fuel ratio of the cylinders variation due to the mismatch between the actual state of the embodiment is reliably avoided.

According to the third aspect of the present invention, if only the fuel supply amount is changed according to the difference in the intake air charging efficiency before and after the switching of the valve operation mode,
If the ignition timing is further changed, the ignition timing correctly corresponding to the intake air charging efficiency after the switching is given.

[0019]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS First, FIGS. 4 and 5 show a specific configuration of a variable valve apparatus.
No. 117261 has already been proposed.

Reference numeral 21 designates a fuel-consumption-oriented cam profile in which both the cam lift and the lift section are small.
A cam (fuel consumption cam) 22 is set to a cam profile that generates a high torque in a low rotation range, and a second cam (low-speed output cam) having a cam lift relatively larger than the first cam 21 and a high rotation cam 23. A third cam (high-speed output cam) which is set to a cam profile that generates a high torque in the region and has a cam lift and a lift section larger than the second cam 22 is provided in parallel on the same cam shaft.

Reference numeral 24 denotes a suction / exhaust valve (an intake valve or an exhaust valve). Reference numeral 25 denotes a main rocker arm which is always in contact with the first cam 21 via a roller 26. Opening and closing the exhaust valve 24;

The main rocker arm 25 has a shaft 3
Two sub rocker arms 2 that swing around 0
8 and 29 are supported in parallel with the roller 26, and one sub rocker arm 28 contacts the second cam 22 and the other sub rocker arm 29 contacts the third cam 23.

When the sub rocker arms 28 and 29 are not engaged with the main rocker arm 25, they are urged by the lost motion spring 31 so as to always contact the second and third cams 22 and 23. It moves (oscillates) independently of the arm 25.

In order to selectively engage the sub rocker arms 28 and 29 with the main rocker arm 25, first, a cylindrical pin 32 is provided at the swinging portion of one of the sub rocker arms 28, and the main rocker arm 25, a pin 34 is coaxially arranged with the pin 32 so as to be slidable in the direction of the camshaft.
4 are normally urged by the return spring 36 and held in the state shown in FIG. 4 and disengaged from the main rocker arm 25, but the hydraulic chamber 3 in which the pin 34 is accommodated is provided.
When the pressurized oil is led to the passage 8 through the passage 40, the pins 32 and 3
4 is pushed out by a predetermined amount, and the sub rocker arm 28 is pushed out.
Are adapted to engage with the main rocker arm 25.

The reason that the sub rocker arm 28 is integrated with the main rocker arm 25 is that the first cam 21 and the second
When the cam 22 is in the base circle, the first
The valve timing is switched according to the second cam 22 having a larger lift than the cam 21.

That is, the characteristic of the first cam 21 focusing on fuel consumption is switched to the characteristic of the second cam 22 focusing on output in a low rotation range.

The other sub-rocker arm 29 is similarly constructed, and when pressure oil is guided to the hydraulic chamber 39 via the passage 41, the pins 35 and 33 are pushed out against the return spring 37, Sub rocker arm 2
9 engages with the main rocker arm 25,
The valve timing is switched so as to depend on the third cam 23 having a larger lift and lift section than the first cam 21 in the same manner as described above, so that a characteristic that emphasizes output in a high rotation range is obtained.

FIG. 6 shows the first cam 21 to the third cam 2.
3 shows valve lift characteristics up to 3. The full-open output characteristics when each cam is used are as shown in FIG. 7. According to the first cam, although the generated torque is low, the fuel efficiency is good and the second cam is good.
The cam has the highest maximum torque in the low rotation range, and the third cam 23 generates less torque in the low rotation range than the second cam 22 but has the largest torque in the high rotation range.

By the way, switching from the first cam 21 to the second and third cams 22 and 23 and vice versa.
A control unit 51 as shown in FIG. 8 is provided to control the switching from 2, 23 to the first cam 21,
The optimum cam is selected according to the operating condition.

The selection of this cam in the control unit 51 is based on the characteristics shown in FIG. 7, and when the required torque and rotation speed are in the area of the first cam 21 which is a fuel-efficient cam, this cam is used. When the accelerator opening increases and the required torque goes out of the area of the fuel consumption cam and moves to the area of the second cam 22, which is a low-speed output cam, for example, the fuel-saving cam is switched to the low-speed output cam, and the rotation speed is changed. Rises from low to high rpm,
It is switched to the third cam 23 which is a high-speed output cam.

For this reason, as shown in FIG. 8, the control unit 51 includes a crank angle sensor 52 for detecting an engine speed and a crank angle position, and an accelerator operation amount sensor for detecting an operation amount (depressed amount) of an accelerator pedal. 53, a signal from an air flow sensor 54 for detecting the intake air amount is input, and based on these signals, when the timing for switching the cam is determined as described above, the two hydraulic chambers 38, 39
The operation of the solenoid valves 45 and 46 for switching the hydraulic pressure to the pressure is controlled.

When the solenoid valve 45 is opened, pressure oil from the oil pump is led to the hydraulic chamber 38 to operate the second cam 22, and the third cam 23 is operated by opening the other solenoid valve 46. The pressure oil is led to the hydraulic chamber 39.

Actually, since it takes a certain time from the command of the cam switching to the actual completion of the switching, the switching has already been performed by the time the cam switching is completed in all the cylinders. Cylinders and cylinders that have not yet been switched are mixed.

By the way, the charging efficiency of fresh air into the cylinder changes greatly with the switching of the cams, and the required amount of fuel supplied between the output cam and the fuel-saving cam is different. When the fuel amount is changed to a value suitable for the cam after the switching, the fuel amount is too large or insufficient than the required value in the cylinders for which the cam switching has not been completed, and the air-fuel ratio varies.

Therefore, in order to avoid such a phenomenon,
The control unit 51 is configured to execute the change of the fuel supply amount injected from the injector 59 in synchronization with the timing at which the cam is actually switched for each cylinder. This ensures that the variance is not prevented.

In addition to the engine parameters for determining the cam switching area, the control unit 51 includes, as a parameter necessary for determining that the cam has been actually switched, the intake manifold of the intake manifold. Suction negative pressure sensor 62 for detecting the pressure, in-cylinder pressure sensor 63 for detecting the pressure in the cylinder, and the hydraulic chambers 38 and 39
Pressure sensor 6 that detects the actuator oil pressure acting on the
By inputting these engine parameters correlated with the cam switching from the torque sensor 65 or the like for detecting the driving torque of the camshaft 4, or the like, and comparing the engine parameters with the previously obtained fluctuation characteristics caused by the cam switching,
The actual cam switching timing is determined for each cylinder.

FIG. 9 shows the control unit 51
FIG. 4 is a flowchart showing a fuel control operation performed based on the determination result of the cam switching timing for each cylinder. The operation will be described with reference to the flowchart. Here, a description will be specifically given at the time of switching from the fuel efficiency cam to the output cam.

In steps 1 and 2, the intake air amount Qa is read from the air flow sensor 54, and the rotational speed N is read from the output of the crank angle sensor 52. From these values, the basic injection pulse width Tp common to all cylinders is calculated by the following equation. It is calculated by an equation (step 3). Tp = K · (Qa / N) (1)

Here, the value of Tp corresponds to the amount of fuel per cylinder required for one combustion cycle for the fuel-efficient cam to obtain the required air-fuel ratio (the stoichiometric air-fuel ratio in the three-way catalyst system).

Then, it is determined based on FIG. 7 whether or not the operating state has reached the switching area of the cam, and if the necessity of the switching is determined, it is determined whether or not the fuel consumption cam is switched to the output cam (step). 4).

Since it is time to switch from the fuel consumption cam to the output cam, the process proceeds to steps 5 to 8, and the switching timing is determined for each cylinder.

Here, taking a four-cylinder engine as an example, the cylinder is switched from the first cylinder for simplicity.
Assuming that the switching is performed in the order of the cylinder number, "0" is stored as an initial value in the memory storing the number of switching cylinders (switching cylinder number), and "1" is stored in the memory at the timing when the first cylinder is switched. In the following, "2" is set when the second cylinder is switched, and "3" is set when the third cylinder is switched.
However, "4" enters at the timing when the fourth cylinder is switched.

As will be described later, in order to calculate the fuel supply amount for each cylinder in synchronization with the cam switching timing for each cylinder, the cylinder injection numbers 1 to 4 are assigned, and the basic injection for each cylinder is added. The pulse width is distinguished by T1 ■ T4.

When the number of switched cylinders is determined in step 5 and none of the cylinders is switched, the basic injection pulse width at this time may be the same for all cylinders. That is, Tn = Tp (step 9). Where n is a cylinder number 1 to 4
Is the number.

Since there is a response delay of the actuator and the like from the time when the cam switching is instructed until the time when the cam is actually switched, step 9 is performed during this time.

Thereafter, when it is determined that the cam is actually switched in the first cylinder based on the fact that the number of switched cylinders has become "1", the basic injection pulse width T1 for the first cylinder is calculated by the following equation. (Steps 6 and 10). T1 = Tp ・ (ηb / ηa) (2)

Here, ηa is the charging efficiency for the cam before switching (that is, the fuel consumption cam), and ηb is the charging efficiency for the cam after switching (that is, the output cam). Although the efficiency of charging air into the cylinder is increased due to the switching of the cam and the amount of air entering the cylinder is increased, if the same fuel amount as before the switching is injected from the injector 59, the air-fuel ratio is leaner than the required value. In order to avoid this, an extra amount of fuel is injected corresponding to the charging efficiency ratio (shift) before and after switching. Note that a difference in filling efficiency can be used.

On the other hand, when only the first cylinder is switched, the other three cylinders (second to fourth cylinders) have not been switched yet.
The basic injection pulse widths T2 to T4 are calculated for one cylinder. T2 = T3 = T4 = (4Tp-T1) / 3 (3)

Here, it is not assumed that T2 = T3 = T4 = Tp. That is, to obtain the required air-fuel ratio, 1
The fuel equivalent required for the combustion cycle is 4 Tp,
The remainder after subtracting the fuel for the first cylinder from this
This is for equally distributing the three cylinders. That is, if Tp is assigned to a cylinder that has not been switched even though a cam switching command has been issued, the air-fuel ratio shifts to the rich side in all cylinders. By reducing the amount of fuel supplied to the remaining cylinders by injecting extra fuel into the set cylinders,
This is to ensure that it does not deviate from the required air-fuel ratio.

At the cam switching timing of the second cylinder (step 7), the basic injection pulse width T given to the second cylinder
2 becomes the same as the first cylinder (step 12), and 4
The fuel obtained by excluding Tp from the cylinders 1 and 2 is distributed to the remaining two cylinders (step 13). This can be expressed as follows: T2 = T1 = TpＴ (ηb / ηa) (4) T3 = T4 = (4Tp−2T1) / 2 (5)

Similarly, when the third cylinder is switched, the following equation is used: T1 = T2 = T3 = Tp ・ (ηb / ηa) (6) T4 = 4Tp-3T1 (7) (Step 8, 14, 15).

The cam switching for all the cylinders is completed at the cam switching timing of the fourth cylinder. Therefore, the basic injection pulse width given at this time becomes the same again for the four cylinders as in the following equation: Tn = Tpp (ηb / ηa) (step 1)
6).

In this way, by providing the fuel supply amount corresponding to the cam after switching in accordance with the switching timing for each cylinder, even when the cam switching is not performed simultaneously between the cylinders, the required air-fuel ratio can be reduced. The cylinders that have shifted are eliminated, and the remainder obtained by subtracting the amount of fuel supplied to the already switched cylinders from the fuel amount of all cylinders required to obtain the required air-fuel ratio is transferred to the cylinders that have not yet been switched. By distributing, variation in the air-fuel ratio can be avoided even for the entire cylinder.

Next, FIGS. 10 and 11 show another embodiment in which the ignition timing is also changed in accordance with the basic injection pulse width T1 to T4 for each cylinder calculated as described above. It is. The same parts as those in FIG. 9 are denoted by the same reference numerals.

As the ignition advance value ADV (ignition timing), a so-called MBT is selected (if the MBT seems to cause knocking, it is retarded to a position where knocking does not occur).
It is read out with reference to a map from the rotational speed N and the basic injection pulse width Tp at that time, but as described above, the basic injection pulse widths T1 to T4 which differ according to the cam switching timing for each cylinder are calculated. However, if the ignition timing is the same for all cylinders, cylinders that deviate from MBT and cylinders that cause knocking occur.

Therefore, the above basic injection pulse widths T1 to T4
, The ignition advance value ADV1 ■ ADV4 is obtained for each cylinder (steps 21 to 34). ADV
1 to 4 attached to are cylinder numbers.

For example, when the first cylinder is switched to the output cam, the basic injection pulse width is different between the first cylinder and the remaining three second to fourth cylinders (steps 10 and 11). Is the ignition advance value ADVb determined from T1 and N
(= ADV1) for the remaining three cylinders, an ignition advance value ADVc (= ADV2 = ADV3 = A) determined from T2 and N.
DV4) is obtained by referring to the map (steps 23 to 26). At this time, ADV1 <ADV2, and
In the first cylinder switched to the output cam, the fuel supply amount is increased more than the remaining cylinders that remain the fuel-efficient cam,
By igniting late, the maximum torque is obtained while avoiding knocking even in the first cylinder. Of course, the maximum torque can be obtained with the remaining three cylinders.

In this way, by changing the ignition timing in accordance with the cam switching timing for each cylinder, the required ignition timing does not coincide with the actual cam state during the cam switching, so that knocking occurs or the maximum It is possible to prevent the occurrence of a cylinder in which torque cannot be obtained.

The map of the ignition advance value to be referred to is N
And a conventional map using Tp as a parameter.

In the following embodiment, both the fuel supply amount and the ignition timing are changed in accordance with the cam switching timing for each cylinder. However, as a counterpart to the previous embodiment, only the ignition timing is changed for each cylinder. It is also conceivable to change it in accordance with the switching timing.

Although the embodiment has been described with reference to switching from the fuel-saving cam to the output cam, the present invention can be applied to the opposite case.

Finally, the correspondence between the flowcharts of FIGS. 9 to 11 and FIGS. 1 to 3 is as follows. Step 4 is the cam selection / switching determining means 2, steps 5 to 8 are the cam switching timing determining means 4, and steps 9 to 16 are the fuel / ignition timing changing means 5 and the fuel supply amount changing means 6, steps 9-1.
6, 21 to 34 fulfill the respective functions of the fuel / ignition timing changing means 7.

[0063] Thus the first invention, Bal by cylinders
The switching timing of the valve operating mode is determined, and the valve operation after switching for each cylinder is synchronized in synchronization with the switching timing.
In order to change the fuel supply amount or ignition timing corresponding to the mode ,
Even when the switching timing of the valve actuation mode is performed at a time between the cylinders, the required fuel and the ignition timing and Bal
Inconsistency with the actual state of the brake operation mode can be reliably avoided.

According to a second aspect of the present invention, changing the fuel supply amount corresponding to the valve operating mode after switching in synchronization with the switching timing of the valve operating mode for each cylinder is based on the intake charging efficiency before and after switching. Since the fuel injection is performed according to the shift, the fuel corresponding to the intake air charging efficiency after switching can be provided correctly, and the fuel and the valve
It is possible to reliably avoid a variation in the air-fuel ratio between the cylinders and a deterioration in the exhaust gas composition due to a mismatch between the actual operation state and the actual state.

In the third aspect of the present invention, not only the fuel but also the ignition timing is changed in accordance with the difference in the intake charging efficiency between before and after the switching of the valve operation mode , so that even when the valve operation mode is switched at different timings, It is possible to prevent occurrence of knocking or occurrence of a cylinder in which the maximum torque cannot be obtained.

[Brief description of the drawings]

FIG. 1 is a diagram corresponding to a claim of the first invention.

FIG. 2 is a diagram corresponding to claims of the second invention.

FIG. 3 is a diagram corresponding to claims of the third invention.

FIG. 4 is a plan view showing an embodiment of the present invention.

FIG. 5 is a sectional view taken along line XX of FIG. 4;

FIG. 6 is a characteristic diagram of a valve lift.

FIG. 7 is a characteristic diagram of a fully open output when each cam is used.

FIG. 8 is a block diagram of a control system.

FIG. 9 is a flowchart showing a control operation executed by the control unit.

FIG. 10 is a flowchart illustrating a control operation performed by a control unit according to another embodiment.

FIG. 11 is a flowchart showing a control operation executed by a control unit of another embodiment.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 cam 2 cam selection / switching determination means 3 cam switching mechanism 4 cam switching timing determination means 5 fuel / ignition timing changing means 6 fuel supply amount changing means 7 fuel / ignition timing changing means 21 first cam (fuel consumption cam) 22 second Cam (output cam) 23 Third cam (output cam) 24 Intake / exhaust valve 25 Main rocker arm 28, 29 Sub rocker arm 45, 46 Solenoid valve 51 Control unit 52 Crank angle sensor (engine speed sensor) 53 Accelerator operation amount Sensor 54 Airflow sensor 59 Injector 60 Ignition device 62 Suction negative pressure sensor 63 In-cylinder pressure sensor 64 Oil pressure sensor 65 Torque sensor

──────────────────────────────────────────────────の Continuation of the front page (51) Int.Cl. ⁷ identification code FI F02P 5/15 F02P 5/15 A (58) Field surveyed (Int.Cl. ⁷ , DB name) F02D 41/00-45 / 00 F02D 13/02

Claims (3)

(57) [Claims] A plurality of valve operating modes having different output characteristics, means for determining selection / switching of a valve operating mode according to an operating state, and a valve operating mode in which at least one of an intake valve and an exhaust valve is selected. Means for determining the switching timing of the valve operation mode for each cylinder in an engine having a switching mechanism for switching, and fuel supply corresponding to the valve operation mode after switching for each cylinder in synchronization with the valve operation mode switching timing Means for changing the amount or the ignition timing. A plurality of valve operating modes having different output characteristics, means for determining selection / switching of the valve operating mode according to an operating state, and at least one of an intake valve and an exhaust valve.
In engines with a switching mechanism for switching a selected valve operating mode, means for determining the timing is switched with the valve operation mode in each cylinder, the valve operation kinetics
Like in synchronization with the switching timing, in accordance with the deviation of the intake air charging efficiency after before switching, output control of the engine, characterized in that it comprises a means for changing the fuel supply amount corresponding to the valve operation mode after switching to each cylinder apparatus. 3. A plurality of valve operating modes having different output characteristics, means for determining selection / switching of a valve operating mode according to an operating state, and at least one of an intake valve and an exhaust valve.
In engines with a switching mechanism for switching a selected valve operating mode, means for determining the timing is switched with the valve operation mode in each cylinder, the valve operation kinetics
Engine, characterized in that it comprises like in synchronization with the switching timing, in accordance with the deviation of the intake air charging efficiency after before switching, and means for changing the ignition timing and fuel supply amount corresponding to the valve operation mode after switching to each cylinder Output control device.