JP2001248464A - Internal combustion engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To perform an exhaust emission control measure before a catalyst activating temperature. SOLUTION: In this internal combustion engine provided with a plurality of electromagnetic driving type intake valves and exhaust valves on cylinders, atomization of fuel is promoted by generation of swirl flow due to partial intake when a part of the plurality of intake valves are closed or lift amount is reduced when the temperature of an exhaust emission control catalyst is below a prescribed value and exhaust emission control performance is low during a cold operation. Therefore, combustion of fuel is stabilized and emission is reduced, and thereby a problem in exhaust emission control is reduced, even if the temperature of the catalyst is not sufficiently raised.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an internal combustion engine having an exhaust purification catalyst in an exhaust passage, and more particularly to an internal combustion engine having not only one intake and exhaust valve but also a plurality of intake and exhaust valves.

[0002]

2. Description of the Related Art Generally, an internal combustion engine is provided with an exhaust gas purifying catalyst in an exhaust passage in order to purify exhaust gas. Oxidation catalysts, three-way catalysts, selective reduction type lean NOx catalysts, occlusion reduction type lean NOx catalysts, and the like are known as exhaust purification catalysts. For example, oxidation catalysts are formed on the surface of granular alumina called catalyst pellets. Noble metal such as palladium (Pd) or palladium + platinum (Pt) that acts is thinly adhered. CO and H in the exhaust gas
C is oxidized to harmless CO ₂ and H ₂ O.

[0003] A three-way catalyst uses platinum (P) on the surface of alumina.
t) + rhodium (Rh) or platinum (Pt) + rhodium (Rh) + palladium (Pd), etc., which are thinly adhered. The three components CO, HC and NOx in the exhaust gas are as follows: The reaction is simultaneously reduced.

(O ₂ , NOx) + (CO, HC, H ₂ ) →
The N ₂ + H ₂ O + CO ₂ selective reduction type lean NOx catalyst is a catalyst that reduces or decomposes NOx in an oxygen-excess atmosphere (lean atmosphere) and in the presence of hydrocarbons (HC). And a catalyst in which a transition metal such as Cu is ion-exchanged and a noble metal is supported in zeolite or alumina. The selective reduction type NOx catalyst is
If the catalyst bed temperature is in the catalyst purification window, the air-fuel ratio of the inflowing exhaust gas is a lean atmosphere, and HC, preferably HC which has been thermally decomposed and has a reduced molecular size, is present in the exhaust gas. Part of the HC is partially oxidized to generate active species, and the active species reacts with NOx in the exhaust gas to produce NOx
To N ₂ , H ₂ O, CO _{2 and the} like.

[0005] The lean NOx storage reduction catalyst uses, for example, alumina as a carrier, and on the carrier, for example, an alkali metal such as potassium K, sodium Na, lithium Li or cesium Cs, or an alkaline earth such as barium Ba or calcium Ca. , Lanthanum La, and at least one selected from rare earths such as yttrium Y, and a noble metal such as platinum Pt. When the ratio of air and fuel (hydrocarbon) supplied to the engine intake passage and the exhaust passage upstream of the NOx catalyst is referred to as the air-fuel ratio of the exhaust gas flowing into the NOx catalyst, the NOx catalyst generates When the fuel ratio is lean, NOx is absorbed, and when the oxygen concentration in the inflowing exhaust gas decreases, the absorbed NOx is released.

[0006]

These catalysts are activated in a predetermined temperature range and can purify exhaust gas. The temperature region is called a catalyst window.

During a cold operation such as when the internal combustion engine is started, the temperature of the catalyst is not raised, and the temperature of the catalyst does not reach the inside of the catalyst window, which is an activation region. on the other hand,
When exhaust gas containing HC, NOx, etc. is discharged due to poor combustion stability, such as at the time of starting, if the catalyst temperature is low, even if such exhaust gas is supplied to the catalyst, it cannot be sufficiently purified.

[0008] The present invention has been made in view of such a point, and when the temperature of the catalyst is not sufficiently raised,
It is an object to reduce the generation of HC, NOx and the like.

[0009]

Means for Solving the Problems To achieve the above object, the internal combustion engine of the present invention employs the following means. That is, the present invention relates to an internal combustion engine having an exhaust purification catalyst in an exhaust passage, an intake valve and an exhaust valve in a cylinder, and at least two intake valves of the intake valve and the exhaust valve. When the temperature of the catalyst is equal to or lower than a predetermined value, valve control means is provided for performing lift control on a part of the plurality of intake valves to an arbitrary position during a period from less than the opening degree of the other intake valves to a fully closed state. It is characterized by the following.

That is, by setting the opening of some of the intake valves to be smaller than the opening of the other intake valves, or by setting the opening to zero (fully closed), the flow of intake air entering the cylinder is controlled, and the swirl is controlled. A flow was created.

In the present invention, at least two of the intake valves and the exhaust valves are provided in the cylinder. That is,
A cylinder having two intake valves and one exhaust valve, a cylinder having two intake valves and two exhaust valves, a cylinder having three intake valves and two exhaust valves, and the like can be given as examples.

In the present invention, the control of the opening of a valve to an arbitrary position during a period from less than the opening of another valve to a fully closed state is referred to as lift control. In the case of a cylinder having two intake valves and one exhaust valve, one of the intake valves is to be controlled. In the case of a cylinder having two intake valves and two exhaust valves, either one of the intake valves or one of the exhaust valves, or both the one intake valve and the one exhaust valve are to be controlled. A cylinder with three intake valves and two exhaust valves also has three of the three intake valves:
One or two are lift-controlled, or one of the two exhaust valves is lift-controlled.

That is, the present invention includes a case where two or more exhaust valves are provided in addition to the intake valve. At this time, the valve control means controls the intake air when the temperature of the exhaust purification catalyst is lower than a predetermined value. It is preferable that a part of each of the valve and the exhaust valve is lift-controlled.

For example, in an internal combustion engine provided with two sets of intake valves and exhaust valves facing each other as the plurality of intake valves and exhaust valves, one set of one set is provided by the valve control means. Preferably, lift control is performed on at least one of the intake valve and the same set of exhaust valves facing the intake valve.

As described above, by controlling the lift of at least a part of the intake valve and the exhaust valve, a swirl flow is generated by the intake and exhaust, and the atomization of the fuel is promoted. As a result, the combustion of the fuel is stabilized, and the emission is reduced. Therefore, even if the temperature of the catalyst is not sufficiently raised, the problem in purifying the exhaust gas is reduced. In addition, since the exhaust heat can be concentrated and guided to the catalyst, warm-up is quickened. Further, since the fuel cell can be operated with a small amount of fuel, fuel efficiency is improved.

The lift control by the valve control means includes, when the intake valve and / or the exhaust valve are fully closed, reducing the lift amount of the intake valve or the exhaust valve. This can be easily performed when the intake valve and the exhaust valve are constituted by electromagnetically driven valves driven by electromagnetic drive. In this case, it is of course possible to positively control the electromagnetic drive valve to energize and perform lift control.However, when the electromagnetic drive valve is not energized, the initial position of the valve is fully closed or half open with a smaller opening degree than full open. When the electromagnetically driven valve is configured to be in a state, the lift control can be performed by a non-energized control. Here, the lift control by the non-energization control is simply referred to as pause control.

In the case where the valve is held in the fully closed state in the lift control, if the valve is an electromagnetically driven valve, only a holding current is required, and other driving currents are not required, and power can be saved. In addition, when the electromagnetically driven valve that performs lift control to the fully closed position is provided with a permanent magnet that holds the valve at the fully closed position, the fully closed control can be performed with lower power consumption.

It is to be noted that the present invention relates to an internal combustion engine provided with an exhaust gas purifying catalyst, when the temperature of the exhaust gas purifying catalyst is lower than a predetermined temperature.
Although the intake and exhaust valves are controlled, this control can be applied when starting the internal combustion engine.

That is, in an internal combustion engine having an intake valve and an exhaust valve in a cylinder, and having at least two intake valves out of the intake valve and the exhaust valve, the intake valve and the exhaust valve are:
An electromagnetically driven valve that is driven by electromagnetic drive, and includes valve control means for performing lift control on a part of the plurality of intake valves during cranking of the internal combustion engine.

By performing lift control on a part of the intake valve during cranking for starting, a swirl flow is generated, and atomization of fuel is promoted, so that the startability of the internal combustion engine is improved. When holding the valve in the fully closed state in the lift control, if the electromagnetically driven valve is used, only the holding current is unnecessary, and other drive currents are not required, so that power can be saved. Using a type with a permanent magnet that holds the valve in the fully closed position reduces the valve drive power and reduces battery
Sufficient power can be supplied to the starter for starting the engine, the cranking speed can be increased, and the startability of the engine can be improved.

In the case of this control, the present invention can be implemented by adding various limiting elements similar to the control based on the catalyst temperature described above. That is, two or more exhaust valves may be provided, and the valve control means may lift control a part of the intake valve and the exhaust valve when the temperature of the exhaust purification catalyst is equal to or lower than a predetermined value.

Further, the plurality of intake valves and exhaust valves are provided with two sets of intake valves and exhaust valves facing each other,
The valve control means may perform lift control on at least one of one set of intake valves and the other set of exhaust valves opposed thereto.

It should be noted that whether or not cranking is being performed can be determined depending on the case where the engine speed is, for example, 400 rpm or less. Further, the present invention provides an internal combustion engine having a plurality of cylinders and an exhaust purification catalyst in an exhaust passage, wherein when the temperature of the exhaust purification catalyst is equal to or lower than a predetermined value, some of the plurality of cylinders The fuel cell system further comprises a deactivated cylinder control means for deactivating the combustion of the cylinder.

If the deactivated cylinder control is performed when the catalyst temperature has not reached the activation temperature, the operating state of the combustion cylinder is increased such that the engine load increases and the intake air increases to withstand the load. In addition, the combustion efficiency is increased, the combustion speed is increased, and the generation of emission is improved, so that the problem of emission of exhaust gas before the activation of the catalyst can be reduced.

In addition, since the load on the combustion cylinder is increased, the temperature of the combustion chamber wall and the bore wall is quickly increased, thereby facilitating warm-up and, consequently, increasing the catalyst temperature. Further, in order to suppress the exhaust emission to a predetermined value, it is necessary to increase the amount of the noble metal to be carried on the catalyst. However, due to the above effect, the amount of the noble metal carried can be reduced, and the cost can be reduced.

Further, it is more effective to provide a lean burn control means for performing lean burn of the cylinder when the temperature of the exhaust gas purifying catalyst is equal to or lower than a predetermined value. This is because the lean combustion can suppress the generation of HC and NOx.

Finally, the components described above can be combined with each other as far as possible.

[0028]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A specific embodiment of an internal combustion engine having an electromagnetically driven valve according to the present invention will be described below with reference to the drawings.

FIG. 1 is a diagram showing a schematic configuration of an internal combustion engine having an electromagnetically driven valve according to the present invention. The internal combustion engine 1 shown in FIG. 1 includes a plurality of cylinders 21 and each cylinder 21
This is a four-cycle gasoline engine equipped with a fuel injection valve 32 for directly injecting fuel into the inside.

The internal combustion engine 1 includes a cylinder block 1b in which a plurality of cylinders 21 and a cooling water passage 1c are formed, and a cylinder head 1a fixed on the cylinder block 1b.

A crankshaft 23 as an engine output shaft is rotatably supported on the cylinder block 1b.
The crankshaft 23 is connected to a piston 22 slidably mounted in each cylinder 21.

Above the piston 22, a piston 2
2 and a combustion chamber 24 surrounded by the wall surface of the cylinder head 1a. An ignition plug 25 is attached to the cylinder head 1a so as to face the combustion chamber 24.
An igniter 25 a for applying a drive current to the ignition plug 25 is connected to the ignition plug 25.

In the cylinder head 1a, the open ends of the two intake ports 26 and the two exhaust ports 27 are formed so as to face the combustion chamber 24, and the injection holes thereof face the combustion chamber 24. A fuel injection valve 32 is attached.

Each open end of the intake port 26 is opened and closed by an intake valve 28 supported on the cylinder head 1a so as to be able to move forward and backward.
It is opened and closed by an electromagnetic drive mechanism 30 (hereinafter, referred to as an intake-side electromagnetic drive mechanism 30) provided on the cylinder head 1a.

Each open end of the exhaust port 27 is opened and closed by an exhaust valve 29 supported on the cylinder head 1a so as to be able to advance and retreat. These exhaust valves 29 are provided on the cylinder head 1a. It is opened and closed by a drive mechanism 31 (hereinafter, referred to as an exhaust-side electromagnetic drive mechanism 31).

Here, a specific configuration of the intake-side electromagnetic drive mechanism 30 and the exhaust-side electromagnetic drive mechanism 31 will be described. still,
Since the intake-side electromagnetic drive mechanism 30 and the exhaust-side electromagnetic drive mechanism 31 have the same configuration, only the intake-side electromagnetic drive mechanism 30 will be described as an example.

As shown in FIG. 2, the intake-side electromagnetic drive mechanism 30 is a casing 300 made of a non-magnetic material and formed in a cylindrical shape.
It has. The housing 300 has a first soft magnetic material having an outer diameter substantially equal to the inner diameter of the housing 300.
The core 301 and the second core 302 are arranged in series with a predetermined gap.

A portion of the first core 301 facing the predetermined gap holds a first electromagnetic coil 303, and a portion of the second core 302 facing the first electromagnetic coil 303 is Second electromagnetic coil 304
Is gripped.

In the predetermined gap, the housing 300
Is provided with a plunger 305 made of a disk-shaped soft magnetic material having an outer diameter substantially equal to the inner diameter of the plunger. The plunger 305 is supported by a first spring 306 held in a hollow portion of the first core 301 and a second spring 307 held in a hollow portion of the second core 302 so as to be able to advance and retreat in the axial direction. I have.

The first spring 306 and the second spring 306
The urging force of the spring 307 causes the plunger 305 to move between the first core 301 and the second core in the predetermined gap.
It is set to be balanced when it is at an intermediate position with respect to the core 302.

On the other hand, the intake valve 28 has a valve body 28x that opens and closes the intake port 26 by sitting on or off a valve seat 200 provided at the open end of the intake port 26 in the combustion chamber 24, and a tip portion thereof. And a cylindrical valve shaft 28y fixed to the valve body 28x.

The valve shaft 28y is connected to the cylinder head 1
a is supported by a cylindrical valve guide 201 provided at a. The base end of the valve shaft 28y extends into the housing 300 of the intake-side electromagnetic drive mechanism 30, and is fixed to the plunger 305 via the hollow portion of the second core 302.

The length of the valve shaft 28y in the axial direction is determined by the fact that the plunger 305
When held at an intermediate position between the core 301 and the second core 302, that is, when the plunger 305 is in a neutral state, the valve body 28x is positioned between the fully open side displacement end and the fully closed side displacement end. It is set to be held at a position (hereinafter, referred to as a middle-open position).

In the intake-side electromagnetic drive mechanism 30 configured as described above, when the exciting current is not applied to the first electromagnetic coil 303 and the second electromagnetic coil 304, the plunger 305 is in the neutral state, and Accompanying valve 2
8x is held in the middle open position.

When an exciting current is applied to the first electromagnetic coil 303 of the intake-side electromagnetic drive mechanism 30, the first core 30
An electromagnetic force is generated between the first and first electromagnetic coils 303 and the plunger 305 in a direction to displace the plunger 305 toward the first core 301.

On the other hand, the second electromagnetic drive mechanism 30 of the intake side
When an exciting current is applied to the electromagnetic coil 304, the second core 302, the second electromagnetic coil 304, and the plunger 305
Between the plunger 305 and the second core 30.
An electromagnetic force is generated in the direction of displacing to the two sides.

Therefore, in the intake-side electromagnetic drive mechanism 30, the exciting current is alternately applied to the first electromagnetic coil 303 and the second electromagnetic coil 304, whereby the plunger 30 is driven.
5, the valve body 28a is driven to open and close. At this time, by changing the timing of applying the exciting current to the first electromagnetic coil 303 and the second electromagnetic coil 304 and the magnitude of the exciting current, the opening / closing timing of the intake valve 28 can be controlled.

Returning to FIG. 1, each intake port 26 of the internal combustion engine 1 is connected to the cylinder head 1a of the internal combustion engine 1.
Is connected to each branch pipe of the intake branch pipe 33 attached to the suction pipe. The intake branch pipe 33 is connected to a surge tank 34 for suppressing pulsation of intake air. An intake pipe 35 is connected to the surge tank 34. The intake pipe 35 is provided with an air cleaner box 3 for removing dust and dirt during intake.
6 is connected.

The intake pipe 35 is provided with an air flow meter 44 for outputting an electric signal corresponding to the mass of the air flowing through the intake pipe 35 (mass of the intake air).
A throttle valve 39 for adjusting the flow rate of intake air flowing through the intake pipe 35 is provided at a position downstream of the air flow meter 44 in the intake pipe 35.

The throttle valve 39 includes a throttle actuator 40 comprising a stepper motor or the like for driving the opening and closing of the throttle valve 39 in accordance with the magnitude of the applied power.
A throttle position sensor 41 for outputting an electric signal corresponding to the opening of the throttle valve 39; and an accelerator position sensor mechanically connected to an accelerator pedal 42 for outputting an electric signal corresponding to the operation amount of the accelerator pedal 42. 43 are attached.

A vacuum sensor 50 for outputting an electric signal corresponding to the pressure of the surge tank 34 is attached to the surge tank 34. On the other hand, each exhaust port 27 of the internal combustion engine 1 communicates with each branch pipe of the exhaust branch pipe 45 attached to the cylinder head 1a. The exhaust branch pipe 45 is connected to the exhaust pipe 4 via an exhaust purification catalyst 46.
The exhaust pipe 47 is connected downstream to a muffler (not shown).

The exhaust branch pipe 45 has an air-fuel ratio of the exhaust gas flowing through the exhaust branch pipe 45, in other words, an exhaust purification catalyst 46.
An air-fuel ratio sensor 48 that outputs an electric signal corresponding to the air-fuel ratio of the exhaust gas flowing into the air-fuel ratio is attached.

The exhaust gas purifying catalyst 46 includes, for example, hydrocarbons (HC) contained in the exhaust gas when the air-fuel ratio of the exhaust gas flowing into the exhaust gas purifying catalyst 46 is a predetermined air-fuel ratio near the stoichiometric air-fuel ratio. Carbon oxide (CO), nitrogen oxide (NOx)
When the air-fuel ratio of the exhaust gas flowing into the exhaust purification catalyst 46 is a lean air-fuel ratio, the three-way catalyst stores nitrogen oxides (NOx) contained in the exhaust gas, and the air-fuel ratio of the inflowing exhaust gas becomes stoichiometric. When the fuel ratio or the rich air-fuel ratio is attained, the occlusion-reduction type NOx catalyst that reduces and purifies while releasing the stored nitrogen oxides (NOx), and the air-fuel ratio of the exhaust gas flowing into the exhaust purification catalyst 46 becomes an oxygen excess state When there is a predetermined reducing agent, nitrogen oxides (NOx) in the exhaust gas are reduced.
It is a selective reduction type NOx catalyst to be purified, or a catalyst obtained by appropriately combining the various catalysts described above.

A catalyst temperature sensor 49 for outputting an electric signal corresponding to the bed temperature of the exhaust purification catalyst 46 is attached to the exhaust purification catalyst 46 described above. The internal combustion engine 1
Is a crank position sensor 51 including a timing rotor 51a attached to an end of the crankshaft 23, an electromagnetic pickup 51b attached to a cylinder block 1b near the timing rotor 51a, and a cooling unit formed inside the internal combustion engine 1. A water temperature sensor 52 attached to the cylinder block 1b for detecting the temperature of the cooling water flowing through the water channel 1c is provided.

An electronic control unit (ECU) 20 for controlling the operation state of the internal combustion engine 1 is provided in the internal combustion engine 1 having the above-described configuration.

The ECU 20 includes a throttle position sensor 41, an accelerator position sensor 43, an air flow meter 44, an air-fuel ratio sensor 48, and a catalyst temperature sensor 4.
9, various sensors such as a vacuum sensor 50, a crank position sensor 51, and a water temperature sensor 52 are connected via electric wiring, and output signals of the sensors are input to the ECU 20.

The ECU 20 includes an igniter 25a,
The intake-side electromagnetic drive mechanism 30, the exhaust-side electromagnetic drive mechanism 31, the fuel injection valve 32, and the like are connected via electric wiring.
The value 0 allows the igniter 25a, the intake-side electromagnetic drive mechanism 30, the exhaust-side electromagnetic drive mechanism 31, and the fuel injection valve 32 to be controlled using the output signal values of various sensors as parameters.

Here, as shown in FIG. 3, the ECU 20 controls the CPs connected to each other by a bidirectional bus 400.
It has a U 401, a ROM 402, a RAM 403, a backup RAM 404, an input port 405 and an output port 406, and has an A / D converter (A / D) 407 connected to the input port 405.

The input port 405 receives an output signal of a sensor that outputs a digital signal, such as the crank position sensor 51, and outputs the output signal to the C port.
The data is transmitted to the PU 401 or the RAM 403.

The input port 405 outputs analog signal type signals such as a throttle position sensor 41, an accelerator position sensor 43, an air flow meter 44, an air-fuel ratio sensor 48, a catalyst temperature sensor 49, a vacuum sensor 50, and a water temperature sensor 52. Output signals of the sensors to be input through the A / D 407, and those output signals
The data is transmitted to the PU 401 and the RAM 403.

The output port 406 is connected to the CPU 40
1 is transmitted to the igniter 25a, the intake-side electromagnetic drive mechanism 30, the exhaust-side electromagnetic drive mechanism 31, and the fuel injection valve 32.

The ROM 402 includes a fuel injection amount control routine for determining the fuel injection amount, a fuel injection timing control routine for determining the fuel injection timing, and the opening of the intake valve for determining the opening timing of the intake valve 28. Valve timing control routine,
Exhaust valve opening timing control routine for determining the valve opening timing of the exhaust valve 29, ignition timing control routine for determining the ignition timing of the spark plug 25 of each cylinder 21, throttle valve 39
In addition to an application program such as a throttle opening control routine for determining the opening of the vehicle, an exciting current is applied to the intake-side electromagnetic drive mechanism 30 and the exhaust-side electromagnetic drive mechanism 31 to control the suspension of the intake valve and the exhaust valve or An intake / exhaust valve control routine program as valve control means for performing lift control is stored.

The ROM 402 stores various control maps in addition to the application programs described above. The control map includes, for example, a fuel injection amount control map indicating a relationship between the operating state of the internal combustion engine 1 and the fuel injection amount, a fuel injection timing control map indicating a relationship between the operating state of the internal combustion engine 1 and the fuel injection timing, An intake valve opening / closing timing control map showing the relationship between the operating state of the internal combustion engine 1 and the opening / closing timing of the intake valve 28, an exhaust valve opening / closing timing control map showing the relationship between the operating state of the internal combustion engine 1 and the opening / closing timing of the exhaust valve 29, Internal combustion engine 1
Current amount control map showing the relationship between the operating state of the engine and the amount of exciting current to be applied to the intake-side electromagnetic drive mechanism 30 and the exhaust-side electromagnetic drive mechanism 31; the operating state of the internal combustion engine 1 and each ignition plug 2
And a throttle opening control map showing the relationship between the operating state of the internal combustion engine 1 and the opening of the throttle valve 39, and the like.

The RAM 403 stores an output signal of each sensor, a calculation result of the CPU 401, and the like. The calculation result is, for example, an engine speed calculated based on an output signal of the crank position sensor 51. The RAM
The various data stored in 403 is rewritten to the latest data every time the crank position sensor 51 outputs a signal.

The backup RAM 45 is a non-volatile memory that retains data even after the operation of the internal combustion engine 1 is stopped, and stores learning values for various controls. The CPU
401 operates according to the application program stored in the ROM 402 to execute the control of the intake and exhaust valves according to the present invention in addition to the fuel injection control, the intake valve opening and closing control, the exhaust valve opening and closing control, the ignition control, and the like. That is, CPU
By executing the intake / exhaust valve control routine program on 401, the valve control means of the present invention is realized.

Hereinafter, control of the intake and exhaust valves according to the present embodiment will be described. <Example of lift control of intake and exhaust valves>
The routine is executed at a predetermined time interval. When this routine is started, first, in step 100, the engine speed ne, the throttle opening th, the accelerator opening, and the like are read, and then, in step 101, the reading is performed. It is determined whether the engine speed is equal to or less than 400 rpm.

If it is 400 rpm or less, it is regarded that cranking is being performed, and in step 102, the opening / closing timing of the intake / exhaust valve (valve timing VT) is calculated. Here, the torque is calculated from the engine speed ne, the throttle opening th, or the accelerator opening read in step 100, and the valve timing corresponding to the calculation result is calculated from a predetermined map. Next, step 103
Then, based on the calculation result, the opening / closing control of the intake valve and the exhaust valve is performed, and a part of the intake valve and the exhaust valve are closed.

Here, as shown in FIG. 4, one of the two intake valves 28a and 28b arranged in parallel is one of the intake valves 28a and 28b.
Is closed, and two parallel exhaust valves 29
a and 29b, the exhaust valve 29b which is diagonally opposed to the closed intake valve 28a is closed. In FIG. 4, ● indicates closed and ○ indicates open.

As a result, in the intake stroke of the internal combustion engine,
When the other intake valve opens, one intake valve remains closed, and when one exhaust valve opens during the exhaust stroke,
The other exhaust valve remains closed. Therefore, when the internal combustion engine shifts from the exhaust stroke to the intake stroke, the intake and exhaust form a swirl flow. When the swirl flow is formed in the exhaust stroke, the swirl flow in the cylinder functions as a so-called priming of the swirl flow in the intake stroke when shifting to the subsequent intake stroke, so the intake swirl flow in the intake stroke is more It is formed smoothly.

When such a swirl flow is formed, the fuel injected into the intake air is evenly atomized by the swirl flow. Thereafter, the fuel is ignited at a predetermined ignition timing in accordance with the ignition control. However, since the fuel is uniformly atomized, the fuel ignition becomes easy even in a cold state, and the engine startability is improved. Further, since the fuel is uniformly atomized by the swirl flow, the combustion becomes good and the exhaust emission is reduced.

Next, in step 101, if the read engine speed is not less than 400 rpm, then in step 104, the catalyst temperature is read. Next, step 1
At step 05, it is determined whether or not the catalyst temperature is equal to or lower than a predetermined activation temperature. If the catalyst temperature is equal to or lower than the predetermined activation temperature, the process proceeds to step 106, and similarly to step 102, the opening / closing timing of the intake / exhaust valve ( Calculation of valve timing VT). Thereafter, in step 103, the opening and closing control of the intake valve and the exhaust valve is performed based on the calculated result, and a part of the intake valve and the exhaust valve are closed as described above.

Therefore, the swirl flow is formed as described above, and the fuel injected during the intake is atomized uniformly by the swirl flow. After that, according to the ignition control,
Although the fuel is ignited at a predetermined ignition timing, since the fuel is uniformly atomized, the combustion becomes good and the exhaust emission decreases. Therefore, even if the temperature of the catalyst is lower than the activation temperature, there is no problem in purifying the exhaust gas.

Finally, if it is determined in step 104 that the catalyst temperature is not lower than the predetermined activation temperature, that is, if the catalyst has reached the predetermined activation temperature range, the process proceeds to step 107, where the intake / exhaust gas is exhausted in the same manner as in step 102. Calculate the valve opening / closing timing (valve timing VT). Then step 1
At 08, based on the calculated result, the opening / closing control of the intake valve and the exhaust valve in the case of the normal operation is performed.

Here, one of the exhaust valves is fully closed, but only one of the intake valves may be fully closed and both exhaust valves may be opened and closed. However, in the above example in which one of the exhaust valves is fully closed, the swirl flow is more easily formed. In addition, dispersion of exhaust heat is prevented, and warming up of the catalyst is expedited.

In the above example, step 103
Although one of the intake valves or the exhaust valves is controlled to be fully closed, the swirl flow is similarly controlled even if the lift amount is smaller than the opening / closing stroke amount of the other intake valve or the exhaust valve, for example, a half-open state, instead of being fully closed. Can be formed.

For the above control, for example, the control pattern is as follows. In Table 1, ● indicates fully closed, ○ indicates fully open, and Δ indicates half open.

[0077]

[Table 1] In the above control, a control range in relation to the catalyst temperature is shown in the figure.

In this figure, the horizontal axis represents time, and the vertical axis represents catalyst temperature. After a lapse of a predetermined time after the start of the engine, the catalyst temperature exceeds the activation temperature. The control of the present invention
It is understood from this figure that the process is executed after the engine is started until the catalyst temperature reaches the catalyst activation temperature.

<Other Example 1> The above example is a control example in the case where two intake valves and two exhaust valves are provided, respectively. Three valves,
Similar control can be performed when two exhaust valves are provided.

First, FIG. 7 shows an example in which two intake valves and one exhaust valve are provided. In this case, when the same condition as the above example is satisfied, that is, at the time of cranking or when the catalyst temperature has not reached the predetermined temperature, one of the intake valves 28a is closed, or the lift amount is set to the other intake valve. Valve 28b
Less.

Next, FIG. 8 shows an example in which three intake valves and two exhaust valves are provided. In this case as well, if the same conditions as in the above example are satisfied, that is, at the time of cranking or when the catalyst temperature has not reached the predetermined temperature, the same control is performed, but the control pattern is as follows. Can be exemplified. In Table 2, ● is fully closed, ○ is fully open, △
Is half-open (the lift amount is smaller than full opening and larger than small opening),
▲ indicates a small opening with a smaller lift than half opening.

[0082]

[Table 2] Further, as is apparent from FIG. 2, the electromagnetically driven valve used in this example is of a type in which the valve is in a half-open state in a rest state, that is, when neither the first electromagnetic coil 303 nor the second electromagnetic coil 304 is energized. The valve.

On the other hand, if an electromagnetically driven valve that is fully closed in the rest state is used, an intake valve and an exhaust valve are provided for each cylinder.
In the case of an example in which two are provided, the following control is performed. In Table 3, ● indicates fully closed and ○ indicates fully open.

[0084]

[Table 3] In such an example, in this control, since the electromagnetically driven valve is stopped, power consumption can be reduced accordingly.

Further, in the example where one exhaust valve is used, the exhaust heat can be concentrated at one source of the exhaust heat, so that the dispersion of the exhaust heat is prevented and the warm-up property of the catalyst can be improved. it can.

The control shown in Table 3 becomes possible even if the valve is of the type that is half-open in the rest state, if it can be kept fully closed (the valve does not move) during the rest. In this case, the power is larger than when no power is supplied, but the power can be saved significantly as compared with the case where the switching operation is performed only by the holding current.

<Other Example 2> As an example of an electromagnetically driven valve used in the present invention, a type in which a valve is held in a fully closed state by a permanent magnet is used for valve fully closed control as lift control of the present invention. It can be used favorably.

As such an electromagnetically driven valve, for example, the one disclosed in Japanese Patent No. 2915426 can be used. It has the configuration shown in FIG. In FIG. 9, the actuator of the valve 123 includes an armature 127 that can reciprocate coaxially with the valve stem 129 for opening and closing the valve. The armature 127 is provided with a suction disk 102 made of soft magnetic steel.
05 and 106 can be moved. Armature 127
Are biased toward the neutral position by springs 111 and 112, and are mechanically connected to these springs via webs 113. The springs 111 and 112 always function as means for urging the armature 127 in a direction away from the position of FIG. 9 attracted by the magnet 105 and the position attracted by the magnet 106. In the state of FIG. 9, the spring 111 is compressed,
12 is extended, but the armature 1 is changed from the state of FIG.
During the stroke of the armature 127 that attracts 27 to the magnet 106, the compressed spring 111 is expanded, and the expanded spring 112 is compressed.

The armature is connected to the damping piston 114 via a lost motion coupling, so that the valve system 129 towards the stroke limit can be rapidly decelerated by the displacement of the fluid in the chamber 139.

The permanent magnet 105 acting on the disk 102
The suction force causes the disc to be held at the raised position, that is, the valve closing position. Similarly, the permanent magnet 106
, And the disc is held at the lowered position in FIG. 9, that is, the valve open position. When releasing the attraction force, a neutralizing magnetic field is generated in the coils 103, 104 superposed on the permanent magnets 105, 106. In operation, one of the coils is energized to counteract the attraction to the disk 102 by the associated magnet and free the disk. As a result, the armature 127 is connected to the springs 111 and 11 in the outer casing 120.
2 accelerates sharply. When the armature 127 passes the neutral position, the springs 111, 112 begin to reduce the valve speed, but when the disk 102 approaches the opposite hand magnet, the large attraction force of the magnet causes the springs 111, 1
Overcome the deceleration force of 12. This large suction force tends to cause an impact state on the suction disk 102, which is mitigated by the deceleration of the armature and the valve by the shock absorber in the outer casing 120.

The springs 111 and 112 have non-linear characteristics, and the spring force is larger than that of the linear characteristic in accordance with the attraction force characteristics of the attraction magnet. This non-linear spring force characteristic allows for more rapid acceleration and deceleration of the valve, which can increase its average speed and reduce response time.

<Embodiment of Inactive Cylinder Control> Here, in order to solve the problems of the present invention, in an internal combustion engine having a plurality of cylinders and an exhaust gas purification catalyst in an exhaust passage, the temperature of the exhaust gas purification catalyst is set to a predetermined value. An embodiment will be described in which a stop cylinder control means for stopping the combustion of some of the plurality of cylinders when the value is equal to or less than the value is provided.

By stopping the fuel injection and ignition for some of the cylinders, it is possible to realize the deactivated cylinder control for deactivating the cylinder. According to the idle cylinder control, the fuel consumption is improved by stopping the fuel injection and reducing the pumping loss in the idle cylinder.

First, an example of the idle cylinder control by the idle cylinder control means will be described. In the example shown below, the deactivated cylinder control means is realized by the ECU deactivating the cylinder at the timing shown in FIGS. 10 to 12 according to a program. In the time charts shown in FIG. 10 and subsequent figures, “IN” and “Ex” represent an intake valve and an exhaust valve, respectively.

(Embodiment 1 of Inactive Cylinder Control) The example shown in FIG. 10 shows the inactive cylinder control in a four-cylinder internal combustion engine.
This is an example in which the idle cylinder is fixed to, for example, # 1 cylinder and # 4 cylinder.

In FIG. 10, the horizontal axis represents the crank angle of the internal combustion engine, and the top dead center (TDC) and bottom dead center (BD) of the piston of each cylinder.
C), and the number of the cylinder in which the explosion occurs is displayed at the top of the figure.

In this embodiment, during execution of the deactivated cylinder control,
Ignition is stopped in the deactivated cylinders # 1 and # 4, and as indicated by hatching in FIGS. 10A and 10D, respectively, for a predetermined period from before the bottom dead center (BDC). The exhaust valve is opened. During operation of the internal combustion engine, the exhaust passage is filled with exhaust gas having a pressure substantially equal to the atmosphere F. For this reason, when the exhaust valve is opened as described above, the exhaust gas is re-inhaled from the exhaust passage into the combustion chamber, so that the in-cylinder pressure of the inactive cylinder substantially increases to the atmospheric pressure.
Then, when the exhaust valve is closed while the piston is displaced toward the top dead center, the exhaust gas re-inhaled into the combustion chamber is compressed. For this reason, after the exhaust valve is closed, the cylinder pressure of the # 4 cylinder, which is the idle cylinder, increases, and the difference in the internal pressure between the # 3 cylinder and the # 4 cylinder decreases. As a result, the vibration of the internal combustion engine is suppressed to a small value.

In this example, the intake valve and the exhaust valve of the deactivated cylinder may be kept closed, but in this case, the vibration of the engine becomes larger than in the case of the above example. (Embodiment 2 of Inactive Cylinder Control) FIG. 11 shows that the intake valve and the exhaust valve are kept closed while the piston makes one reciprocation from the bottom dead center where the combustion stroke ends in each cylinder to the next bottom dead center. 5 is a time chart in a case where cylinders are sequentially stopped.

The operation example shown in FIG. 11 realizes the deactivated cylinder control by operating the internal combustion engine in six cycles, and is a method of sequentially changing the deactivated cylinder. Hereinafter, the idle cylinder control for sequentially changing the idle cylinder by operating the internal combustion engine for 6 cycles is referred to as 6-cycle idle cylinder control.

For example, in the # 1 cylinder shown in FIG.
The intake stroke and the compression stroke are performed in sections Tl and T2, respectively, and the combustion stroke is performed in the subsequent section T3. In sections T4 and T5 following the section T3, the intake valve and the exhaust valve are kept closed, and the # 1 cylinder is stopped. In the rest periods T4 and T5, the piston is displaced toward the top dead center and the bottom dead center, respectively, so that the combustion chamber 26 is compressed and expanded while being shut off from both the intake port 22 and the exhaust port 24. You. After the exhaust stroke is performed by opening the exhaust valve in a section T6 following the section T5, the intake, compression, explosion, pause (compression), pause (expansion), and exhaust strokes are performed again. Done. Similarly, in other cylinders, immediately after the end of the combustion stroke, while the piston makes one reciprocation between the bottom dead center and the top dead center, the intake valve and the exhaust valve are held closed so that intake and compression are performed. , Explosion, rest (compression), rest (expansion), and exhaust strokes are realized. That is, in the six-cycle inactive cylinder control shown in FIG. 11, the internal combustion engine is operated in six cycles of intake, compression, explosion, inactivity (compression), inactivity (expansion), and exhaust. One cylinder, # 3 cylinder, # 2 cylinder, and # 4 cylinder are sequentially changed.

As can be seen from FIG. 11, the explosion of the # 3 cylinder is performed 180 ° CA later than the # 1 cylinder, and
The cylinder explosion occurs 360 ° CA later than the # 3 cylinder. In addition, the explosion of the # 4 cylinder is 180 times more than that of the # 2 cylinder.
° CA delayed, and the # 1 cylinder explosion was # 4
This is performed 360 ° CA later than the cylinder. Therefore,
On the basis of the case where combustion is sequentially performed in each cylinder at every 180 ° CA, in the combustion order of # 1 cylinder → # 3 cylinder → # 2 cylinder → # 4 cylinder, between # 3 cylinder and # 2 cylinder, and ,
The combustion is stopped between the # 4 cylinder and the # 1 cylinder, respectively.

(Embodiment 3 of Inactive Cylinder Control) FIG. 12 is a time chart showing still another inactive cylinder control. As shown by hatching in FIGS. 12C and 12D, in the # 3 cylinder and # 4 cylinder, the exhaust valve is opened during the suspension period after the end of the combustion stroke.

In the idle period of the # 3 cylinder and the # 4 cylinder, the in-cylinder pressure does not increase even if the piston is displaced toward the top dead center by opening the exhaust valve. Therefore, as shown in FIG. 13A, when the in-cylinder pressure rises due to the explosion of the # 2 cylinder near the time point tl, the in-cylinder pressure of the inactive # 3 cylinder is prevented from rising. Similarly, when the in-cylinder pressure increases due to the explosion of the # 1 cylinder near the time point t4, the in-cylinder pressure of the inactive # 4 cylinder is prevented from increasing. That is, the peak of the in-cylinder pressure in each cylinder occurs independently. As a result, as shown in FIG. 13B, the peak value of the combined in-cylinder pressure is kept substantially constant, and the vibration of the internal combustion engine is suppressed.

(Embodiment of the present invention based on idle cylinder control)
The vibrations of the internal combustion engine in the above three cylinder control modes have different results. However, when the temperature of the catalyst is not sufficiently raised, the cylinder control means is used to reduce the generation of HC, NOx and the like. It is effective to suspend the combustion of some of the plurality of cylinders.

Hereinafter, an embodiment of the present invention based on deactivated cylinder control will be described with reference to FIG. First, step 201
It is determined whether or not the catalyst temperature has reached the activation temperature. If the catalyst temperature has reached the activation temperature, in step 202, normal operation control of the engine after warm-up is performed.

On the other hand, if it is determined in step 201 that the catalyst temperature is equal to or lower than the predetermined activation temperature, the routine proceeds to step 203, where the above-described deactivated cylinder control is performed. As described above, when the deactivated cylinder control is performed when the catalyst temperature has not reached the activation temperature, there are the following merits.

As the efficiency is improved, the fuel consumption is improved, and the amount of emission generated is reduced because the fuel consumption is small. As for the combustion cylinder, an engine load becomes high, and an operation state such as an increase in intake air to withstand the load is performed. Therefore, the combustion efficiency is increased, and emission is improved.

That is, when the idle cylinder control is performed, the amount of generated HC is smaller than in the case of the all-cylinder operation, so that the problem of the exhaust gas emission before the catalyst is activated can be reduced. In addition, since the combustion efficiency of the combustion cylinder is increased, the temperature of the combustion chamber wall and the bore wall is quickly increased, so that the warm-up can be promoted and the catalyst temperature can be promoted.

Further, in order to suppress the exhaust emission to a predetermined value, it is necessary to increase the amount of the noble metal to be carried on the catalyst. However, due to the above effects, the amount of the noble metal carried can be reduced, and the cost can be reduced. it can.

(Embodiment of the Present Invention Based on Inactive Cylinder Control and Lift Control) Next, an embodiment in which lift control of intake and exhaust valves is added in addition to inactive cylinder control will be described with reference to FIG.

First, at step 201, it is determined whether or not the engine coolant temperature is equal to or lower than a predetermined temperature. If this temperature is equal to or lower than the predetermined temperature, it is determined that the catalyst temperature has not yet reached the activation temperature, and if the cooling water temperature is higher than the predetermined temperature, it is determined that the catalyst temperature has reached the activation temperature.

If the temperature of the cooling water is higher than the predetermined temperature, it is determined that the catalyst temperature has reached the activation temperature. Therefore, in step 202, normal operation control of the engine after warm-up is performed.

On the other hand, if it is determined in step 201 that the cooling water temperature is equal to or lower than the predetermined temperature, that is, if it is determined that the catalyst temperature is equal to or lower than the predetermined activation temperature, the process proceeds to step 203, Perform cylinder control.

During this time, with respect to the working cylinder in the operating state, one of the two intake valves is stopped in a fully closed state, and the other intake valve is opened later than usual timing (see FIGS. 10 to 12). 204a). The exhaust valve is opened later than usual (step 204b).

As described above, when the catalyst temperature has not reached the activation temperature, the merit of performing the deactivated cylinder control is as follows.
This is the same as described in the previous embodiment. Here, further, by performing the lift control of the intake valve in step 204a, the swirl flow is formed as described above, and the fuel injected during the intake is evenly atomized by the swirl flow. After that, the fuel is ignited at a predetermined ignition timing according to the ignition control. However, since the fuel is uniformly atomized, the combustion becomes good and the exhaust emission decreases. Therefore, even if the temperature of the catalyst is lower than the activation temperature, there is no problem in purifying the exhaust gas.

(Embodiment of the Present Invention Based on Inactive Cylinder Control and Lift Control) Next, in addition to the inactive cylinder control and the lift control of the intake and exhaust valves, the air-fuel ratio control of the combustion cylinder is performed, so that the temperature of the exhaust purification catalyst is reduced. An embodiment in which emission is suppressed when the value is equal to or less than a predetermined value will be described.

As shown in FIG. 16, when the air-fuel ratio is made lean, HC, CO and NOx decrease. Therefore, a lean burn control means for performing the lean burn operation of the engine when the temperature of the exhaust purification catalyst is equal to or lower than a predetermined value is provided. This means is also realized by the ECU.

When this control is applied to the example of FIG. 15, FIG.
It looks like 7. Here, Step 201, Step 2
02, step 203, step 204a, step 2
04b is the same as described above, and a description thereof will be omitted.

In this example, after step 204a, lean burn control is executed (step 205). When the catalyst temperature reaches the activation temperature, the lean combustion is terminated, and the stoichiometric operation (operation at the stoichiometric air-fuel ratio) can be performed.

The lean burn control may be combined only with the deactivated cylinder control, or may be combined with only the lift control. Since the exhaust emission is improved by the lean burn control, the above-mentioned effect is further enhanced, and even if the catalyst is at or below the activation temperature, there is no problem in exhaust purification.

[0121]

According to the present invention, there is provided an internal combustion engine having an exhaust gas purification catalyst in an exhaust passage, an intake valve and an exhaust valve in a cylinder, and at least two or more intake valves of the intake valve and the exhaust valve. When the temperature of the exhaust gas purifying catalyst is equal to or lower than a predetermined value and the exhaust gas purifying ability is low, a part of the plurality of intake valves is closed or the lift amount is reduced, or the valve is stopped for that purpose (hereinafter, referred to as "the following"). Therefore, a swirl flow due to the intake air is generated, and the atomization of the fuel is promoted. This stabilizes fuel combustion and reduces emissions, so even if the catalyst is not sufficiently heated,
Problems in exhaust gas purification are reduced.

In the case where a plurality of exhaust valves are provided, in the exhaust stroke, if a part of the exhaust valves is stopped, the formation of a swirl flow in the intake air is promoted. Heat can be concentrated and catalyst warm-up is accelerated.

Such control can be performed more effectively than when an electromagnetically driven valve driven by electromagnetic drive is used as the intake valve and the exhaust valve. If this control is used at the time of cranking of the internal combustion engine, at the time of cranking for starting, a part of the intake valve is stopped, etc., so that a swirl flow is generated and the atomization of fuel is promoted. The startability of the engine is improved.

When using an electromagnetically driven valve that is fully closed at rest, power can be saved by resting, and from this viewpoint, startability can be improved.
Further, according to the present invention, when the catalyst temperature has not reached the activation temperature, the deactivated cylinder control is performed, so that the amount of generated HC can be reduced as compared with the case of all-cylinder operation. Emission problems can be reduced.

Further, by adding the lean burn control to these, the generation of HC can be suppressed and the effect can be further increased.

[Brief description of the drawings]

FIG. 1 is a diagram showing an outline of an internal combustion engine according to the present invention.

FIG. 2 is a view showing an electromagnetically driven valve as an intake valve and an exhaust valve according to the present invention.

FIG. 3 is a block diagram showing an ECU.

FIG. 4 is a diagram showing an arrangement of a 4-valve intake valve and an exhaust valve.

FIG. 5 is a flowchart showing an intake / exhaust valve control routine of the present invention.

FIG. 6 is a graph showing a control range of the present invention.

FIG. 7 is a diagram showing an arrangement of a three-valve intake valve and an exhaust valve.

FIG. 8 is a diagram showing an arrangement of a 5-valve intake valve and an exhaust valve.

FIG. 9 is a diagram showing an example of an electromagnetically driven valve capable of holding a fully closed / fully opened state with a permanent magnet.

FIG. 10 is a diagram showing a first embodiment of the deactivated cylinder control.

FIG. 11 is a diagram showing a second embodiment of the deactivated cylinder control.

FIG. 12 is a diagram showing a third embodiment of the deactivated cylinder control.

FIG. 13 is a diagram illustrating an engine vibration state according to a third embodiment of the stopped cylinder control.

FIG. 14 is a flowchart showing an embodiment of the present invention based on idle cylinder control.

FIG. 15 is a flowchart showing an embodiment of the present invention by idle cylinder control and lift control.

FIG. 16 is a graph showing the emission characteristics of HC, CO, and NOx depending on the air-fuel ratio.

FIG. 17 is a flowchart illustrating an embodiment of the present invention in which air-fuel ratio control is added to idle cylinder control and lift control.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Internal combustion engine 20 ... ECU (Realize valve control means, deactivated cylinder control means, lean burn control means) 21 ... Cylinder 28 ... Intake valve 29 ... Exhaust valve 30, 31 ... Electromagnetic drive mechanism 46 ... Exhaust purification catalyst 401 ... CPU

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) F01N 3/20 F01N 3/20 D 3/24 3/24 R F02D 13/06 F02D 13/06 E 17 / 02 17/02 U 41/02 301 41/02 301C 41/04 305 41/04 305A 45/00 301 45/00 301D (72) Inventor Shoji Katsumada 1 Toyota Town, Toyota City, Aichi Prefecture Inside Toyota Motor Corporation (72) Inventor Keiji Yoeda 1 Toyota Town, Toyota City, Aichi Prefecture, Toyota Motor Corporation (72) Inventor Hideyuki Nishida 1 Toyota Town, Toyota City, Aichi Prefecture, Toyota Motor Corporation (72) Inventor Kazuhiko Shiratani Toyota Motor Co., Ltd. 1 Toyota Town, Toyota City, Aichi Prefecture (72) Inventor Tomomi Yamada 1 Toyota Motor Corporation Toyota City, Toyota City, Aichi Prefecture FTA 3G018 AA05 AB09 AB17 BA38 CA12 DA26 DA36 DA41 DA43 DA65 EA02 EA17 EA21 EA26 EA33 EA35 FA01 FA06 FA08 FA11 FA16 FA25 FA26 GA08 GA09 GA11 GA31 GA32 3G084 AA03 BA09 BA23 CA01 DA10 FA07 FA10 FA11 FA27 A29 A3A3A3 AB05 AB06 BA03 BA14 BA15 BA19 BA32 CB02 CB03 CB05 CB06 CB07 CB08 DB10 EA01 EA05 EA06 EA07 EA16 EA18 EA31 EA34 3G092 AA01 AA06 AA09 AA11 AA14 CA04 DA01 HA02 HA03 HA01 HA02 HA03 JA25 JA26 KA01 LA07 LB04 MA01 NE15 PA01Z PA07Z PA11Z PD03Z PD12Z PF03Z

Claims (11)

[Claims] 1. An internal combustion engine having an exhaust purification catalyst in an exhaust passage, an intake valve and an exhaust valve in a cylinder, and at least two intake valves of the intake valve and the exhaust valve. When the temperature of the catalyst is equal to or lower than a predetermined value, valve control means is provided for performing lift control on a part of the plurality of intake valves to an arbitrary position during a period from less than the opening degree of the other intake valves to a fully closed state. An internal combustion engine characterized by the following. 2. The exhaust valve is provided with two or more exhaust valves, and when the temperature of the exhaust gas purification catalyst is equal to or lower than a predetermined value, the valve control means controls a part of the intake valve and the exhaust valve to another intake valve or an exhaust valve. 2. The internal combustion engine according to claim 1, wherein the lift control is performed at an arbitrary position during a period from a time when the valve is less than an opening degree to a fully closed state. 3. The plurality of intake valves and exhaust valves are provided with two sets each including an intake valve and an exhaust valve facing each other, and the valve control means includes one set of intake valves and one set thereof facing each other. 2. The internal combustion engine according to claim 1, wherein at least one of the other set of exhaust valves is lift-controlled. 4. The valve control means according to claim 1, wherein said intake valve and / or exhaust valve are fully closed.
3. The internal combustion engine according to any one of 3. 5. The internal combustion engine according to claim 1, wherein the intake valve and the exhaust valve are electromagnetically driven valves driven by electromagnetic driving. 6. An intake valve and an exhaust valve are provided in a cylinder, and
In an internal combustion engine provided with at least two or more intake valves of an intake valve and an exhaust valve, the intake valve and the exhaust valve are electromagnetically driven valves that are driven by electromagnetic drive, An internal combustion engine comprising valve control means for performing lift control of a part of an intake valve to an arbitrary position during a period from the opening degree of another intake valve to a fully closed state. 7. The exhaust valve is provided with two or more exhaust valves, and the valve control means causes a part of the intake valve and the exhaust valve to be connected to another intake valve or an exhaust valve when the temperature of the exhaust purification catalyst is equal to or lower than a predetermined value. 7. The internal combustion engine according to claim 6, wherein the lift control is performed to an arbitrary position during a period from a time when the valve is less than an opening degree to a fully closed state. 8. The plurality of intake valves and exhaust valves are provided with two pairs of intake valves and exhaust valves facing each other, and the valve control means includes one set of intake valves and one pair thereof. 8. The internal combustion engine according to claim 7, wherein at least one of the other set of exhaust valves is lift-controlled. 9. The internal combustion engine according to claim 6, wherein the valve control means stops the intake valve and / or the exhaust valve in a closed state. 10. In an internal combustion engine having a plurality of cylinders and an exhaust purification catalyst in an exhaust passage, when the temperature of the exhaust purification catalyst is equal to or lower than a predetermined value, a part of the plurality of cylinders is selected. An internal combustion engine comprising a deactivated cylinder control means for deactivating combustion of a fuel cell. 11. The lean combustion control means according to claim 1, further comprising a lean burn control means for lean burn of the cylinder when the temperature of the exhaust purification catalyst is lower than a predetermined value. Internal combustion engine.