JPH0566237U - Control device for internal combustion engine - Google Patents

Abstract

(57) [Summary] [Object] The present invention relates to a control device for an internal combustion engine, and an object thereof is to make it possible to significantly improve the HC emission amount during deceleration operation. [Configuration] A phase variable timing mechanism 7 for changing the phase of the opening / closing timing of at least one of an intake valve and an exhaust valve
In the internal combustion engine having No. 1, the deceleration operation state detection means 61 for detecting a deceleration operation state in which the load level of the internal combustion engine is lower than the set load and the rotation speed of the internal combustion engine is higher than the set rotation speed, and the deceleration operation state detection means 61. When the deceleration operation state is detected by, the opening / closing timing phase of the intake valve or the exhaust valve is changed by the phase variable timing mechanism 71 so that the overlap section of the intake valve and the exhaust valve becomes shorter than in other operating states. An opening / closing timing control means 62 for controlling the operation is provided.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

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

[0002]

[Prior Art]

 Conventionally, an automobile engine has been operated in various states such as start-up, warm-up, steady state, acceleration and deceleration. For example, when operating in a deceleration state (low load, high rotation) Due to the decrease in density and the increase in internal EGR, there are cases where combustion is not established, and the fuel injected by this is discharged as HC (hydrocarbons). And such a problem is remarkable especially at low temperature.

[0003]

[Problems to be solved by the device]

 Therefore, it has been conventionally proposed to perform fuel cut or lean air-fuel ratio during deceleration operation, but due to problems such as drivability and engine stall, it is impossible to perform fuel cut during full deceleration operation. Therefore, new measures to replace or be added to this are needed.

The present invention was devised under such circumstances, and it is an object of the present invention to provide a control device for an internal combustion engine, which is capable of significantly improving the HC emission amount during deceleration operation.

[0005]

[Means for Solving the Problems]

 Therefore, the control device for an internal combustion engine of the present invention is an internal combustion engine equipped with a phase variable timing mechanism that changes the phase of the opening and closing timing of at least one of the intake valve and the exhaust valve, and the load level of the internal combustion engine is greater than the set load. When the deceleration operation state is detected by the deceleration operation state detection means that detects a deceleration operation state in which the rotation speed of the internal combustion engine is higher than the set rotation speed, On the other hand, an opening / closing timing control means for controlling the opening / closing timing phase changing operation of the intake valve or the exhaust valve by the phase variable timing mechanism is provided so that the overlap section of the intake valve and the exhaust valve becomes shorter. It is characterized by that (claim 1).

Further, the control device for an internal combustion engine of the present invention is configured so that when the internal combustion engine is a spark ignition type internal combustion engine and the deceleration operation state is detected by the deceleration operation state detection means, another operation is performed. It is characterized in that a spark energy increasing means for increasing spark energy for ignition is provided as compared with the case of the state (claim 2).

[0007]

[Action]

 In the control device for an internal combustion engine according to the present invention (claim 1), when the deceleration operation state is detected by the deceleration operation state detection means, the opening / closing timing control means compares the intake valve with other operation states. Also, the opening / closing timing phase changing operation of the intake valve or the exhaust valve by the phase variable timing mechanism is controlled so that the overlap section of the exhaust valve becomes short.

Further, in the control device for an internal combustion engine according to the present invention (Claim 2), when the deceleration operation state is detected by the deceleration operation state detection means, the spark energy increase means compares the deceleration operation state with other operation states. , The spark energy for ignition is increased.

[0009]

【Example】

 An embodiment of the present invention will be described below with reference to the drawings. FIGS. 1 to 8 show a control device for a spark ignition type engine as an embodiment of the present invention. FIG. 2 is an overall control block diagram, FIG. 3 is an overall configuration diagram showing the engine system, FIG. 4 is an electric circuit diagram of the ignition device, FIG. 5 is a flow chart for explaining the control routine, and FIGS. Is also a diagram for explaining the operation thereof, and FIG. 9 is a flow chart for explaining the dwell angle control routine.

Now, the engine system controlled by the present device is as shown in FIG. 3. In FIG. 3, the engine EG has an intake passage 2 and an exhaust passage 3 communicating with the combustion chamber 1, The intake passage 2 and the combustion chamber 1 are controlled to communicate with each other by an intake valve 4, and the exhaust passage 3 and the combustion chamber 1 are controlled to communicate with each other by an exhaust valve 5. 2a is a surge tank.

The intake passage 2 is provided with an air cleaner 6, a throttle valve 7 and an electromagnetic fuel injection valve (injector) 8 in this order from the upstream side, and the exhaust passage 3 is provided from the upstream side. A catalytic converter (three-way catalyst) 9 for purifying exhaust gas and a muffler (silencer) not shown are provided in that order. The injectors 8 are provided in the intake manifold portion by the number of cylinders. Now, assuming that the engine EG of this embodiment is an in-line four-cylinder engine, four injectors 8 are provided. That is, it can be said that the engine is a so-called multi-point fuel injection (MPI) system engine.

Further, the throttle valve 7 is connected to an accelerator pedal via a wire cable so that the opening degree changes according to the amount of depression of the accelerator pedal. It can also be opened / closed by an ISC motor), which allows the opening of the throttle valve 7 to be changed without idling the accelerator pedal when idling.

Further, each cylinder is provided with an ignition plug 18 toward the combustion chamber 1, and each ignition plug 18 is connected to a distributor 54 as shown in FIG. It is connected to the coil device 51. Then, a high voltage is generated in the ignition coil device 51 by the off operation of the power transistor circuit 52 with the ignition coil device 51, and any of the four spark plugs 18 connected to the distributor 54 is sparked. Is becoming. The ignition coil device 51 starts charging when the power transistor in the power transistor circuit 52 is turned on. Here, the ignition plug 18, the distributor 54, the ignition coil device 51, and the power transistor circuit 52 constitute the ignition device 50.

With such a configuration, the air taken in through the air cleaner 6 according to the opening degree of the throttle valve 7 is mixed in the intake manifold portion with the fuel from the injector 8 so as to have an appropriate air-fuel ratio, and the combustion chamber 1 After the ignition plug 18 is ignited at an appropriate timing in the inside of the exhaust gas, the mixture is burned to generate engine torque, and then the mixture is discharged as exhaust gas into the exhaust passage 3 and the catalytic converter 9 converts the exhaust gas in the exhaust gas. After the three harmful components of CO, HC and NOx are purified, they are silenced by the muffler and released to the atmosphere side.

Further, a phase variable tag for changing the phase of the opening / closing timing of one or both of the intake valve 4 and the exhaust valve 5 as shown in FIGS. 6 (a) to (c) or 7 (a) to (c). An imming mechanism 71 is provided, and in order to obtain any one of the characteristics shown in FIGS. 6A to 6C, for example, Japanese Utility Model Publication No. 61-145806, Japanese Utility Model Publication No. 61-179307, The variable valve timing device described in Japanese Utility Model Laid-Open No. 61-27908 may be used. To obtain any of the characteristics shown in FIGS. 7A to 7C, for example, Japanese Patent Laid-Open No. 61-250312. The variable valve timing device described in Japanese Unexamined Patent Publication, etc. may be used.

A specific example of opening / closing timing for realizing the characteristics of FIGS. 7A to 7C is shown in Table 1 below, for example.

[0017]

[Table 1]

It should be noted that IO (intake valve open) and EC (exhaust valve closed) are values based on the top dead center TDC, and IC (intake valve closed) and EO (exhaust valve open) are based on the bottom dead center BDC. It is the value. Therefore, the relationship among these IO (intake valve open), IC (intake valve closed), EO (exhaust valve open), EC (exhaust valve closed) is shown in FIG. Further, various sensors are provided to control the engine EG. First, on the intake passage 2 side, as shown in FIG. 3, an air flow sensor 11 for detecting the intake air amount from the Karman vortex information, an intake temperature sensor 12 for detecting the intake air temperature, and an atmospheric pressure are provided in the air cleaner installation portion. An atmospheric pressure sensor 13 for detecting the throttle valve is provided, and a potentiometer-type throttle sensor 14 for detecting the opening degree of the throttle valve 7 and an idle switch 15 for detecting an idling state are provided in a portion where the throttle valve is provided. And a motor position sensor for detecting the position of the ISC motor.

On the exhaust passage 3 side, an oxygen concentration sensor (O ₂ sensor) 17 for detecting the oxygen concentration (O ₂ concentration) in the exhaust gas is provided on the upstream side of the catalytic converter 9 near the combustion chamber 1. Is provided. Further, as another sensor, a water temperature sensor 19 for detecting an engine cooling water temperature is provided, and a crank angle sensor 21 for detecting a crank angle (this crank angle sensor 21 is an engine speed sensor for detecting an engine speed N). In the following, the crank angle sensor 21 may be referred to as an engine speed sensor, if necessary, and the TDC sensor 22 for detecting the top dead center of the first cylinder (reference cylinder), respectively. 54.

By the way, the detection signal from the sensor is input to the electronic control unit (ECU) 23. The ECU 23 is also supplied with a voltage signal from a vehicle speed sensor 20 for detecting a vehicle speed, a battery sensor 25 for detecting a voltage of a battery 24 (see FIG. 2), and a signal from a cranking switch 26. The hardware configuration of the ECU 23 is as shown in FIG. 2. The ECU 23 has a CPU 27 as its main part, and the CPU 27 is provided with an intake air temperature sensor 12, an atmospheric pressure sensor 13, a throttle sensor 14, an O sensor. ₂ The detection signals from the sensor 17, the water temperature sensor 19 and the battery sensor 25 are input via the input interface 28 and the A / D converter 30, and detected by the idle switch 15, the vehicle speed sensor 20 and the cranking switch 26. Signals are input via the input interface 29, and detection signals from the air flow sensor 11, the crank angle sensor 21, and the TDC sensor 22 are directly input to the input port.

Further, the CPU 27 stores, via the bus line, a ROM 31 that stores program data and fixed value data, a RAM 32 that is updated and sequentially rewritten, and a memory that stores the battery 24 while the battery 24 is connected. Data is exchanged with a battery backup RAM (BURAM) 33 that is backed up by holding the contents.

The data in the RAM 32 are erased and reset when the ignition switch is turned off. Further, the CPU 27 outputs a fuel injection control signal via the injector driver 34 to sequentially drive the four injectors 8 and outputs an ignition timing control signal to the ignition device 50 via the ignition triber 53. The four ignition plugs 18 are sequentially sparked, and the phase variable timing control signal is output to the phase variable timing mechanism 71 via the driver 70.

At this time, the control mode based on the phase variable timing control signal output from the ECU 23 is as follows. That is, when a deceleration operating state in which the load level of the engine EG is lower than the set load and the engine speed is higher than the set rotational speed is detected, the intake valve 4 and the exhaust valve 5 are overlapped more than in other operating states. The opening / closing timing phase changing operation of the intake valve 4 or the exhaust valve 5 by the phase variable timing mechanism 71 is controlled so that the section becomes short.

Therefore, as shown in FIG. 1, the ECU 23 of the deceleration operation state detecting means 61 for detecting the deceleration operation state in which the load level of the engine EG is lower than the set load and the engine speed is higher than the set speed. When the deceleration operation state is detected by the function and the deceleration operation state detection means 51, the overlap variable section of the intake valve 4 and the exhaust valve 5 is shortened as compared with the case of other operation states, so that the variable phase timing mechanism is provided. The function of the opening / closing timing control means 62 for controlling the opening / closing timing phase changing operation of the intake valve 4 or the exhaust valve 5 by 71 is provided.

Also, as shown in FIG. 1, when the deceleration operation state detection means 61 detects the deceleration operation state, the ECU 23 produces spark energy for ignition as compared with other operation states. It also has the function of the spark energy increasing means 63 for increasing the spark energy. Next, a specific example for increasing the spark energy for ignition as described above will be described. That is, in this embodiment, as described above, the CPU 27 outputs the ignition timing control signal to the power transistor circuit 52 via the ignition driver 53, and further the ignition coil device 51 to the four ignition plugs via the distributor 50. 18 is sequentially sparked, and in this case, the ignition driver 53 has an on-timing setting counter 531, an ignition timing setting counter 532, an RS flip-flop 533, and an AND as shown in FIG. It is configured to include a gate 534 and a delay circuit (delay) 535.

Here, the on-timing setting counter 531 and the ignition timing setting counter 532 are counters that are triggered by a signal from the CPU 27 to start the countdown, and preset values M1 and M2 (M1>) from the CPU 27, respectively. M2) is input, and when it is counted down to a value corresponding to the preset values M1 and M2 and becomes zero, a pulse signal to that effect is output.

The flip-flop 533 is a signal output when the on-timing setting counter 531 is zero, and is output when the ignition timing setting counter 532 is zero. The flip-flop is reset, and the output of the flip-flop 533 turns on / off the power transistors 52a and 52b of the power transistor circuit 52.

When the flip-flop 533 is reset, the power transistors 52a and 52b of the power transistor circuit 52 are turned off, and when the flip-flop 533 is set, the power transistors 52a and 52b of the power transistor circuit 52 are turned on. Therefore, the counter 531 determines the ignition coil charging timing, and the counter 532 determines the ignition timing timing. Since the charging is generally performed after ignition, preset values M1 and M2 (M1> M2) are set so that the output pulse is first output from the counter 532 and then the output pulse is output from the counter 531. There is.

Therefore, the preset values M1 and M2 have information of the primary side energization time (dwell angle) for spark ignition to the ignition coil device 51. Further, the AND gate 534 outputs the spark energy increase control signal from the CPU 27 (this control signal is "1" when it is desired to increase the spark energy, and "0" otherwise) and the output of the flip-flop 533. , And receives the signal delayed by the delay circuit 535 to perform a logical product operation.

Further, the power transistor circuit 52 includes the two power transistors 52a and 52b as described above, and one power transistor 52a is connected to the output terminal of the flip-flop 533 and the other power transistor 5a. 2b is connected to the output terminal of the AND gate 534. The ignition coil device 51 also includes two ignition coils 51a and 51b. One ignition coil 51a is connected to one power transistor 52a, and the other ignition coil 51b is connected to the other power transistor 52b. There is.

The ignition coils 51a and 51b are connected to the ignition plug 18 via the distributors via the backflow prevention diodes D1 and D2, respectively. Therefore, when it is not desired to increase the spark energy, the AND gate 534 is turned off by the "0" signal from the CPU 27, the power transistor 52b and the ignition coil 51b are deactivated, and one power transistor is turned off. Only 52a and ignition coil 51a are activated. As a result, the spark plug 18 can be operated with normal spark energy.

On the other hand, when it is desired to increase the spark energy, the AND gate 534 is turned on when the output of the flip-flop 533 is input by the “1” signal from the CPU 27. As a result, when the output of the flip-flop 533 is output, first the power transistor 52a and the ignition coil 51a are activated to spark the spark plug 18, but after a predetermined delay time, the other power transistor 52b, The ignition coil 51b also operates, and the spark plug 18 continues to spark. As a result, the spark energy can be increased more than the normal spark energy to operate the spark plug 18.

Next, the control routine in this embodiment will be described with reference to FIG. First, in step A1, the temperature condition is checked based on whether the engine cooling water temperature Tw is lower than a predetermined value Tws. If Tw <Tws, the volume efficiency Ev having the engine load information is set in step A2. It is determined whether or not it is smaller than a value Evs (this Evs is a value of about 550 mHg when converted to the manifold negative pressure).

If Ev <Evs, it is determined in step A3 whether the engine speed N is higher than a set value N s (this Ns is a value of about 1000 rpm, for example). If N> Ns, that is, if the engine is in the deceleration operation state in which the load level of the engine is lower than the set load and the engine speed is higher than the set speed, a spark energy large command is issued in step A4. Specifically, the CPU 27 outputs a "1" signal to the AND gate 534 of the ignition driver 53.

After that, in step A6, it is determined whether or not the set time has elapsed since the overlap large command was issued, based on whether or not the timer value T ₁ has become zero. This is a determination step for considering the mechanical characteristics when switching the phase variable timing mechanism 71 that changes the phase of the valve opening / closing timing. If the set time has elapsed, it is determined in step A8 whether the flag FLG is 1 and whether the previous state was the spark energy normal command. If so. That is, if the transition state from the spark energy normal state to the spark energy large state is in a transitional state, the timer value T ₂ is set to the set value T ₂ s in step A10, and then the phase variable timing mechanism 71 is set in step A11. If the flag FLG is not "1", that is, if the previous state is not the spark energy normal command while issuing the small overlap command, step A10 is skipped, and the small overlap command is issued to the phase variable timing mechanism 71 in step A11. Give out. After that, the flag FLG is set to 0 (step A12).

As a result, when the deceleration operation state is detected, the intake valve 4 by the phase variable timing mechanism 71 is set so that the overlap section of the intake valve 4 and the exhaust valve 5 becomes shorter than in the other operation states. Alternatively, since the opening / closing timing phase changing operation of the exhaust valve 5 is controlled, the increase of the internal EGR amount can be prevented and the HC emission amount can be reduced.

Further, when the deceleration operation state is detected, the spark energy for ignition is increased as compared with the case of other operation states, so that the combustion can be improved and further Reduction of HC is expected. By the way, if Tw ≧ Tw in step A1, or Ev ≧ Evs in step A2, or N ≦ Ns in step A3, a spark energy normal command is issued in step A5. Specifically, the CPU 27 outputs a "0" signal to the AND gate 534 of the ignition driver 53.

After that, in step A7, it is determined whether or not the set time has elapsed since the overlap small command was issued, based on whether or not the timer value T ₂ has become zero. Similar to the process of step A6, this process is also a determination step for considering the mechanical characteristic when the phase variable timing mechanism 71 for changing the phase of the valve opening / closing timing is switched.

If the set time has elapsed, it is determined in step A9 whether the flag FLG is 0 and whether the previous state was the spark energy large command. If so. That is, if it is in the transitional state of switching from the large spark energy state to the normal spark energy state, the timer value T ₁ is set to the set value T ₁ s in step A13, and then the phase variable timing mechanism 71 is set in step A14. While issuing a large overlap command to set the overlap amount to the normal size, if the flag FLG is not 0, that is, if the previous state is not a large spark energy command, jump step A13 and step. At A14, a large overlap command is issued to the phase variable timing mechanism 71. After that, the flag FLG is set to 1 (step A15).

As described above, during other operations including the idle operation state, the overlap section is returned to the normal size, so that it is possible to prevent the output reduction, reduce the NOx generation amount, etc. It is also possible to reduce the load on the battery by making the battery normal. If NO in step A6, the process of step A9 and subsequent steps is continued, and if NO in step A7, the process of step A8 and subsequent steps are continued.

Further, in the flowchart shown in FIG. 5, the temperature condition (step A1) may be deleted so that the overlap is always reduced and the spark energy is increased during the deceleration operation, and when the variable valve timing is performed. When using the one using hydraulic pressure, the temperature condition is judged between step A4 and step A6 instead of step A1 or in addition to step A1, and the variable valve timing may cause malfunction. When the temperature is low (Tw <Tw1: but Tw1 <Tws), only the spark energy increase may be executed during the deceleration operation, and the overlap amount may be kept large as usual. If necessary, the variable phase timing mechanism 71 may be further controlled in an operating state other than the deceleration operation.

Further, in the above case, as the spark energy increasing means, the ignition device 50 having the two sets of power transistors 52a and 52b and the ignition coils 51a and 51b is used. In addition to using the systems 51a and 52a, both ignition systems 51a, 51b, 51b and 52b were used when the spark energy increased, but the ignition device 50 having one power transistor 52a and the ignition coil 51a or An ignition device 50 having two sets of power transistors 52a and 52b and ignition coils 51a and 51b is used, and when the spark energy is normal, a normal energization time is set. An energization time longer than the power application time may be set. That is, the increase / decrease of spark energy may be controlled by the dwell angle control.

A method for controlling the increase / decrease in spark energy by performing such dwell angle control will be described below with reference to FIG. First, in step B1, it is determined whether or not there is a spark energy large command, and if it is a spark energy normal command, in step B2 the basic energization time θ ₁ is set and this is set to θ, while spark energy If it is a large command, in step B3, θ ₂ larger than the basic energization time θ ₁ is set, and this is set as θ.

Then, after steps B2 and B3, θ + θ _{VB is set} to θ _{out in} step B4. Here, θ _VB is a battery voltage correction value. After that, in step B5, it is determined whether or not θ _out > θ _max (θ _max is a maximum value that θ _out can take and is a value determined from the engine speed and the like). If not, in step B7, the on timing of the power transistor 52a (or 52a, 52b) is set based on θ _out . If θ _out > θ _{max is} not set, then in step B6, θ _out = θ _max is set, and then in step B7, on-timing of the power transistor 52a (or 52a, 52b) is set based on θ _out. To do.

As a result, when the spark energy is normal, the normal energization time can be set, and when the spark energy is increased, the energization time longer than the normal energization time can be set, thereby improving combustion. Furthermore, it is expected that HC will be reduced. Although not shown in the figure for fuel injection control (injector drive time control), means for setting the fuel injection time for the injector 8 according to the engine operating state is provided. A desired air-fuel ratio control is executed by sequentially injecting a desired amount of fuel by the four injectors 8 based on a signal from the injection time setting means.

[0046]

[Effect of the device]

 As described above in detail, according to the control device for an internal combustion engine (claim 1) of the present invention, an internal combustion engine having a phase variable timing mechanism for changing the phase of the opening / closing timing of at least one of the intake valve and the exhaust valve. , A deceleration operation state detecting means for detecting a deceleration operation state in which the load level of the internal combustion engine is lower than a set load and the rotation speed of the internal combustion engine is higher than a set rotation speed, and the deceleration operation state detection means When the state is detected, the opening / closing timing phase of the intake valve or the exhaust valve by the phase variable timing mechanism is set so that the overlap section of the intake valve and the exhaust valve becomes shorter than in other operating states. With a simple configuration in which the opening / closing timing control means for controlling the changing operation is provided, it is possible to prevent an increase in the internal EGR amount, thereby reducing the HC emission amount There is an advantage that you can.

Further, in the control device for an internal combustion engine of the present invention (claim 2), when the internal combustion engine is a spark ignition type internal combustion engine, and the deceleration operation state is detected by the deceleration operation state detection means, Compared to other operating conditions, the spark energy increasing means for increasing the spark energy for ignition is provided, so that the combustion can be improved and further reduction of HC can be expected. is there.

[Brief description of drawings]

FIG. 1 is a control block diagram of a main part in a control device for an internal combustion engine as an embodiment of the present invention.

FIG. 2 is an overall control block diagram of a control device for an internal combustion engine as an embodiment of the present invention.

FIG. 3 is an overall configuration diagram showing an engine system having the present device.

FIG. 4 is an electric circuit diagram of an ignition device according to an embodiment of the present invention.

FIG. 5 is a flowchart illustrating a control routine according to an embodiment of the present invention.

FIG. 6 is a view for explaining the operation of the embodiment of the present invention.

FIG. 7 is a view for explaining the operation of the embodiment of the present invention.

FIG. 8 is a view for explaining the operation of the embodiment of the present invention.

FIG. 9 is a flowchart illustrating a dwell angle control routine according to an embodiment of the present invention.

[Explanation of symbols]

1 Combustion Chamber 2 Intake Passage 2a Surge Tank 3 Exhaust Passage 4 Intake Valve 5 Exhaust Valve 6 Air Cleaner 7 Throttle Valve 8 Electromagnetic Valve (Injector) 9 Catalytic Converter 11 Air Flow Sensor 12 Intake Air Temperature Sensor 13 Atmospheric Pressure Sensor 14 Throttle Sensor 15 Idle Switch 17 O ₂ sensor 18 Spark plug 19 Water temperature sensor 20 Vehicle speed sensor 21 Crank angle sensor (engine speed sensor) 22 TDC sensor 23 Electronic control unit (ECU) 24 Battery 25 Battery sensor 26 Cranking switch 27 CPU 28, 29 Input interface 30 A / D converter 31 ROM 32 RAM 33 Battery backup RAM (BURAM) 34 Injector driver 50 Ignition device 51 Ignition coil device 51a, 51b Ignition coil Second ignition timing control power transistor circuits 52a, 52b power transistor 53 ignition driver 54 Distributor 70 driver 71 phase variable timing mechanism 531 for on-timing setting counter 532 ignition timing setting counter 533 RS flip-flop 534 the AND gate 535 delay circuits EG engine

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification code Office reference number FI technical display location F02P 9/00 305 A 8923-3G

Claims (2)

[Scope of utility model registration request] 1. An internal combustion engine having a phase variable timing mechanism for changing the opening / closing timing of at least one of an intake valve and an exhaust valve, wherein the load level of the internal combustion engine is lower than a set load and the rotational speed of the internal combustion engine is low. A deceleration operation state detecting means for detecting a deceleration operation state that becomes higher than a set speed, and when the deceleration operation state is detected by the deceleration operation state detection means, the intake valve and the exhaust gas are compared with those in other operation states. An internal combustion engine, comprising: an opening / closing timing control means for controlling an opening / closing timing phase changing operation of the intake valve or the exhaust valve by the phase variable timing mechanism so that the overlap section of the valve becomes short. Control device. 2. When the internal combustion engine is a spark ignition type internal combustion engine, and when the deceleration operation state is detected by the deceleration operation state detection means, spark energy for ignition is compared to when it is in another operation state. 2. The control device for an internal combustion engine according to claim 1, further comprising a spark energy increasing means for increasing the engine.