JP2003035178A - Valve timing control device for internal combustion engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a valve timing control device for an internal combustion engine capable of optimally performing the advance angle control of an intake valve closing timing, only when a prescribed negative pressure is needed in a negative pressure tank, without needing to provide a pressure sensor therein. SOLUTION: Brake conditions in Fig. 12 (c) are detected, and when a bake is applied and the pressure inside an intake pipe in Fig. 12 (e) is at a positive pressure side rather than the prescribed negative pressure, the closing position of the intake valve is advanced, so as to be shown as a point B in Fig. 12 (d). Since an intake air amount blown back from the inside of a combustion chamber to the intake pipe is reduced by advancing, the pressure inside the intake pipe is changed to the negative pressure side rather than the prescribed negative pressure. In other words, since the pressure inside the intake pipe is made negative accordingly, when the brake is applied, the negative pressure is introduced into a brake tank, only when it is necessary.

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 equipped with a variable valve timing mechanism for turning on and off a brake.
The present invention relates to a valve timing control device for an internal combustion engine that variably controls valve timing based on OFF.

[0002]

2. Description of the Related Art Conventionally, a valve timing control device for changing the valve timing of an internal combustion engine according to the operating state of the internal combustion engine has been known (for example, Japanese Patent Laid-Open No. 59-119).
No. 007). That is, for example, this device delays the closing timing of the intake valve when the load of the internal combustion engine is low to reduce intake pumping loss and improve fuel efficiency.

Generally, in a vehicle brake system, a negative pressure in an intake pipe is introduced into a brake booster (negative pressure tank),
This negative pressure is used to double the brake pedal force of the driver. By the way, if the closing timing of the intake valve is retarded, the negative pressure in the intake pipe becomes small. When the negative pressure in the intake pipe becomes small, the negative pressure in the negative pressure tank is consumed when the brake is used, and the negative pressure is not introduced. I can't get pressure. If the brake is used in this state, the driver needs a large pedaling force, which deteriorates the feeling of use of the brake. To solve this problem,
Japanese Patent No. 3129802 discloses a technique of outputting a control signal to a valve timing control device to advance the closing timing of the intake valve timing when it is determined that the pressure in the negative pressure tank is on the positive pressure side with respect to a predetermined pressure. Has been done.

[0004]

However, in the above-mentioned conventional technique, the tank internal pressure sensor is used to detect the negative pressure in the negative pressure tank, which may increase the cost. Also, in this technique, as a substitute for the tank internal pressure sensor, the pressure is detected by the pressure sensor in the intake pipe, and when the detected pressure becomes a positive pressure side from a predetermined negative pressure, the closing timing of the intake valve may be advanced. It is disclosed.
However, in this case, when the intake pipe pressure becomes more positive than the predetermined negative pressure, the closing timing of the intake valve is always advanced, so that, for example, the delay of the intake opening timing for the purpose of reducing pumping loss is delayed. The frequency of performing the angle control decreases, and there is a possibility that desired performance cannot be satisfied.

In addition to this, when the control for retarding the intake valve is performed, if the intake pipe internal pressure does not reach a desired negative pressure, the same problem as described above occurs. For example,
Japanese Patent Application 2000-368501 proposed by our inventors
The technique of No. 1 is a technique of executing the technique of retarding the intake valve open position when the control is executed during the early warm-up of the catalyst. First, in the catalyst early warm-up technology, by retarding the ignition timing at cold start of the internal combustion engine, the propagation speed of combustion is slowed down, and afterburning is performed in the exhaust passage, the catalyst is quickly raised. We are carrying out warm. Usually, in the idle operation state, the target rotation speed is set, and the rotation speed is controlled to reach this target rotation speed. In this idle operation state, when the catalyst is being warmed up early, the ignition timing is retarded, resulting in insufficient torque. This shortage of torque is compensated by increasing the intake air amount. For this reason,
When the ignition timing retard control is executed, the pressure in the intake pipe increases as the intake air amount increases.

At the time of ignition retard control for early catalyst warm-up, the technology of Japanese Patent Application No. 2000-368501 improves the intake flow velocity and promotes atomization of injected fuel.
With the aim of improving combustion, the pressure in the intake pipe,
The opening timing of the intake valve is retarded in order to increase the pressure difference with the pressure in the combustion chamber. However, even if an attempt is made to improve combustion, the pressure in the intake pipe does not always reach a desired negative pressure due to the ignition timing retardation for early warm-up of the catalyst, and in the technique of the above publication, the intake valve is always advanced. The problem of being lost appears remarkably.

That is, in the above-mentioned conventional method, when the pressure sensor in the negative pressure tank is eliminated and the intake valve closing timing advance control is performed on the basis of the pressure in the intake pipe, in particular, the catalyst is warmed up early. As described above, when the pressure in the intake pipe is on the positive pressure side of the desired pressure, the closing timing of the intake valve is advanced, and retard control of the intake valve for the purpose of improving combustion cannot be performed. There is a problem.

Therefore, in the present invention, it is not necessary to provide a pressure sensor in the negative pressure tank, and the advance control of the closing timing of the intake valve is optimally performed only when a predetermined negative pressure is required in the negative pressure tank. It is an object of the present invention to provide a valve timing control device for an internal combustion engine capable of implementing the above.

[0009]

According to the invention of claim 1, there is provided a variable intake valve timing mechanism for variably setting the relative position of the intake valve with respect to the crankshaft of the internal combustion engine,
In a valve timing control device for an internal combustion engine, which calculates the closed position of the intake valve according to the operating state of the internal combustion engine, and controls the closed position of the intake valve based on the calculation result, the closed position of the intake valve is And a first advance control means for advancing the closed position of the intake valve based on the operating state of the brake when the position is retarded from the control position of the bottom dead center.

Normally, the negative pressure in the brake tank is only consumed when the brake is used. Therefore, by advancing the closed position of the intake valve based on the operating state of the brake, the blowback to the intake pipe is suppressed and the pressure in the intake pipe is reduced to a negative pressure only when the negative pressure is consumed. Therefore, the negative pressure can be introduced into the brake tank only when the negative pressure is required. Therefore, the intake pipe pressure can be maintained at a negative pressure only when a negative pressure is required in the brake tank without providing a pressure sensor in the brake tank, and thus, for example, to suppress pumping loss or to improve combustion. Therefore, the retard control of the intake valve closing position can be appropriately performed.

Further, usually, because of early warm-up of the catalyst, when the ignition timing is retarded by the ignition timing control means, the torque due to combustion decreases. At this time, the intake air amount control means increases the intake air amount to compensate for the shortage of the torque in order to maintain the target rotation speed. Therefore, by increasing the amount of intake air, the pressure in the intake pipe becomes close to atmospheric pressure, so if the brake is used and negative pressure is consumed while the ignition timing is retarded, the next time The driver feels a sense of discomfort because a large pedaling force is required when using the brake.

Therefore, as in the invention of claim 2, a target rotational speed setting means for setting a target rotational speed of the internal combustion engine,
Intake air amount control means for controlling the rotation speed by increasing the intake air amount by opening the throttle valve so that the target rotation speed is reached when the rotation speed is reduced;
A catalytic converter provided in the exhaust pipe, ignition timing control means for controlling the ignition timing according to the operating state of the internal combustion engine, and variable intake valve timing for variably setting the relative position of the intake valve with respect to the crankshaft of the internal combustion engine. A valve timing control device for an internal combustion engine, comprising a mechanism, which calculates a closed position of the intake valve according to an operating state of the internal combustion engine, and controls the closed position of the intake valve based on a result of the calculation. The control means is configured to include means for retarding the ignition timing from the ignition timing set based on a normal operating state in order to quickly raise the temperature of the catalytic converter when the internal combustion engine is cold started. A first advance angle for advancing the closed position of the intake valve based on an operating state of a brake when the closed position of the intake valve is retarded from a bottom dead center And a control means.

As a result, when the ignition timing retard control is executed, the position of the intake valve is advanced based on the state of the brake, so that the blowback to the intake pipe can be suppressed. Therefore, when it is necessary to introduce a negative pressure into the brake tank, the pressure in the intake pipe can be made negative, and the inside of the brake tank is appropriately maintained at a negative pressure, and, for example, pumping loss is suppressed. Therefore, the retard control of the intake valve closing position for improving combustion can be appropriately performed even during the early catalyst warm-up.

Further, the larger the retard amount of the ignition timing, the more the pressure in the intake pipe becomes close to the atmospheric pressure. Therefore, as in the invention of claim 3, the ignition timing by the ignition timing control means, or the ignition timing. The negative pressure in the intake pipe can be accurately maintained by setting the advance amount of the intake valve closing position based on the retard amount when the intake valve is retarded.

Further, according to the invention of claim 4, there is provided pressure detecting means for detecting the pressure in the intake pipe of the internal combustion engine, and the advance angle control means is adapted to detect the pressure in the intake pipe detected by the pressure detecting means. When the pressure is higher than the predetermined negative pressure, the closed position of the intake valve is advanced based on the state of the brake.

Thus, when the pressure in the intake pipe is higher than the negative pressure required in the brake tank, the internal pressure of the intake pipe is increased only when the negative pressure needs to be introduced into the brake tank based on the state of the brake. The pressure can be negative.

At this time, as in the fifth aspect of the present invention, the first advance angle control means, based on the pressure detected by the pressure detection means, advances the amount of advance of the closed position of the intake valve. By setting, the negative pressure in the intake pipe can be accurately maintained.

According to a sixth aspect of the present invention, the first advance angle control means advances the closed position of the intake valve when the brake is turned on, and a predetermined period after the brake is turned off. After that, the advance of the closed position of the intake valve is ended.

As a result, the closed position of the intake valve is appropriately maintained on the advance side until the negative pressure is introduced into the brake tank.

According to the seventh aspect of the present invention, the first advance angle control means advances the closed position of the intake valve to a position where the piston provided in the internal combustion engine is near the bottom dead center.

As a result, the period during which the intake valve is open after bottom dead center is suppressed, so that the intake air supplied into the combustion chamber can be suppressed from being blown back into the intake pipe, and the inside of the intake pipe can be suppressed. Can be held at negative pressure.

By the way, when the so-called valve overlap amount increases while the intake valve and the exhaust valve are open at the same time, the combustion gas generated by combustion remains in the combustion chamber. It is known that combustion becomes unstable when the residual amount of combustion gas increases. Therefore, as in the invention of claim 8, the first advance angle control means advances the closed position of the intake valve so that the period in which the exhaust valve and the intake valve are simultaneously opened is a predetermined period or less. Then, it is possible to prevent the combustion from becoming unstable.

Further, in the invention of claim 9, the first advance angle control means advances the closed position of the intake valve based on the state of the brake when a predetermined condition is satisfied.

For example, the invention according to claim 10 is provided with a rotation speed detecting means for detecting the rotation speed of the internal combustion engine, and the predetermined condition is that the rotation speed detected by the rotation speed detecting means is a predetermined rotation speed. In the following cases, it is advisable to advance the closed position of the intake valve based on the state of the brake.

According to the invention of claim 11, an engine water temperature detecting means for detecting the cooling water temperature of the internal combustion engine, and / or
Alternatively, an intake air temperature detecting means for detecting the temperature of intake air taken into the combustion chamber of the internal combustion engine is provided, and the predetermined condition is
The cooling water temperature and / or the intake air temperature is equal to or higher than a predetermined temperature.

That is, when the cooling water temperature or the intake air temperature is below a predetermined temperature, the friction of the piston is large,
Under this condition, the first advance angle control may be prohibited.

According to a twelfth aspect of the present invention, the intake valve closing position is advanced before the ignition timing is retarded by the ignition timing control means after the internal combustion engine is started. Two advance angle control means are provided.

Thus, for example, when the ignition timing is retarded for early warm-up of the catalyst when the pressure in the intake pipe reaches a predetermined negative pressure, the closed position of the intake valve is advanced at the time of starting. As a result, the pressure in the intake pipe can be quickly made negative. Therefore, the ignition timing retard for the early warm-up of the catalyst can be promptly executed after the internal combustion engine is started.

According to the thirteenth aspect of the present invention, the combustion state detecting means for detecting the combustion state of the internal combustion engine is provided, and the first advance control means stabilizes the combustion state detected by the combustion state detecting means. During this period, the closed position of the intake valve is advanced based on the braking state.

As a result, when the combustion state is deteriorated, the closed position of the intake valve is not advanced, so that the deterioration of the combustion state can be suppressed.

In the fourteenth aspect of the present invention, the combustion state detecting means detects the combustion state of the internal combustion engine based on the fluctuation of the rotation speed or the fluctuation of the torque of the internal combustion engine. It can be detected accurately.

According to a fifteenth aspect of the present invention, there is provided combustion stabilizing means for stabilizing combustion when the combustion state detected by the combustion state detecting means is unstable.
The combustion stabilizing means is an air-fuel ratio weak rich control means for controlling the air-fuel ratio due to combustion of the internal combustion engine to be slightly rich, an ignition timing control means for advancing the ignition timing of the internal combustion engine by a predetermined amount, and closing of the intake valve. Combustion is stabilized by providing at least one of a retard control means for retarding the position and an intake valve lift control means for controlling the lift of the intake valve to be large.

As a result, when the combustion state deteriorates, it is possible to stabilize the combustion state using any one or more of the above means, and it is possible to suppress the deterioration of the drivability.

[0034]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS <First Embodiment> An embodiment of the present invention will be described in detail below with reference to the drawings.

FIG. 1 is a schematic configuration diagram showing a double overhead cam type internal combustion engine to which a valve timing control device for an internal combustion engine according to an embodiment of the present invention is applied and its peripheral equipment.

In FIG. 1, 1 is an internal combustion engine, 2 is a rotation angle θ of a crankshaft 31 as a drive shaft of the internal combustion engine 1.
A crank angle sensor for detecting a crk signal, 3 is a water temperature sensor for detecting a cooling water temperature Thw signal of the internal combustion engine 1, and 4 is a rotation angle θcam signal of a cam shaft 33 as a driven shaft on the intake valve 32 side of the internal combustion engine 1. The cam angle sensor 5 for calculating the relative rotation angle (displacement angle) from the phase difference from the rotation angle θcrk signal from the crank angle sensor 2 is a throttle opening degree for detecting the throttle opening degree TA signal of the throttle valve 14. It is a sensor.

Reference numeral 6 denotes an intake pressure sensor (intake air amount signal detected by an air flow meter or the like and engine speed N for detecting an intake pressure (intake air pressure) Pm signal to the internal combustion engine 1.
The intake air pressure may be calculated based on e. ), 7 are installed in the middle of the oil passage, and the oil temperature Th of the hydraulic oil is
An oil temperature sensor that detects an o signal, 8 is an accelerator opening sensor that detects an accelerator opening AP signal as an accelerator operation amount, and 9 is a hydraulic control valve (Oil-flow Control Valve: hereinafter) that adjusts and controls the hydraulic pressure of hydraulic oil. , OCV), 10 is an intake valve as an actuator that controls the camshaft 33 to a target relative rotation angle (target displacement angle) that is a target phase difference with the crankshaft 31 by the hydraulic pressure adjusted by the OCV 9. The hydraulic variable valve timing control mechanism (Va
riable valve timing cont
roll MechaniSm: hereinafter referred to as VVT).

[0038] This VVT is configured as an operating mechanism,
Reference numeral 11 is an oil strainer for sucking up working oil from the oil pan of the internal combustion engine 1, 12 is an oil pump for pumping working oil, and 13 is an actuator for driving a throttle valve 14 in an electronic throttle system.
The C motor, 20 detects the operating state of the internal combustion engine 1 based on input signals from various sensors, calculates an optimum control value,
An ECU that outputs a drive signal to the OCV 9 and the DC motor 13
(Electronic Control Unit:
Electronic control unit).

Next, the electrical configuration of the ECU 20 will be described. The ECU 20 is a C as a well-known central processing unit.
PU (not shown), ROM storing control program
(Not shown), RAM (not shown) for storing various data, cooling water temperature Thw signal from water temperature sensor 3, throttle opening TA signal from throttle opening sensor 5, intake pressure signal from intake pressure sensor 6 Pm, an oil temperature Tho signal from the oil temperature sensor 7, and an A / D conversion circuit (not shown) for converting each analog signal of the accelerator opening AP signal from the accelerator opening sensor 8 into a digital signal, the crank angle sensor 2 A waveform shaping circuit 25 for shaping the rotation angle θcrk signal from the motor and the rotation angle θcam signal from the cam angle sensor 4,
The drive signal IDOCV based on the Duty (duty ratio) control value DOCV of the OCV calculated by the CPU 21 based on these various information is OCV9, and the drive signal ITAEX based on the output throttle opening TAEX is the DC motor 1
3 is configured as a logical operation circuit including an output circuit 26 for outputting to each.

The control program of the valve timing control device for the internal combustion engine according to the present embodiment having the above-described configuration will be described in detail with reference to FIGS. The flowchart of FIG. 2 is a main program of the present embodiment, and is a program that is started, for example, every 180 ° CA in synchronization with the rotation of the crankshaft 31. First,
In step S100, E is determined as the start determination of the internal combustion engine.
Engine rotation speed Ne calculated by calculation of CU20
However, for example, it is determined whether or not 400 rpm is exceeded.
Here, if the speed does not exceed 400 rpm, this routine is finished as it is. On the other hand, the engine speed Ne is 40
When the start determination is made that the internal combustion engine has started, the engine speed exceeds 0 rpm, and the process proceeds to step S200. Step S20
At 0, it is determined whether or not it is the execution condition of the first idle. Here, the fast idle is the conventionally known idle operation in which the engine speed Ne is set to be higher than the normal idle speed at the cold start. The conditions for executing the first idle include, for example, (1) the engine speed Ne is equal to or lower than a predetermined speed (2) the cooling water temperature Thw detected by the water temperature sensor is equal to or higher than the predetermined temperature 1 (3) the cooling water temperature detected by the water temperature sensor. Thw is a predetermined temperature of 2 or lower (4) The intake air temperature is a predetermined temperature of 3 or higher.

Under the condition (1), the engine speed Ne being equal to or lower than the predetermined speed as the first idle means that the engine speed is slightly higher than the normal idle speed, that is, the engine speed is low. This is because the fast idle is performed even in the load region. The conditions (2) and (4) are conditions for prohibiting the fast idle at an extremely low temperature as an operating condition that increases friction. The condition (3) is a condition for indicating that the engine is cold started. (Predetermined temperature 1, predetermined temperature 3 <predetermined temperature 2) If such a fast / idle execution condition is satisfied, the intake valve closing control 1 is executed in step S300 to end the present routine. If the execution condition is not satisfied, the intake valve closing control 2 is performed in step S400, and the present routine is ended. When the first / idle execution condition is satisfied, ignition timing retard control is executed as described later. And intake valve closed position control 1
Is for setting the target intake valve closed position for improving the intake flow velocity and the combustion stability when the first idle execution condition is satisfied. Further, the intake valve closed position 2 is the control when the fast / idle execution condition is not satisfied, and the intake valve 32 is advanced to the inside of the brake tank during the period from the start determination to the satisfaction of the fast / idle execution condition. The control is performed to introduce a desired negative pressure to the engine, and when the other fast idle execution conditions are not satisfied, that is, in the operating state after the end of the catalyst early warm-up, the normal intake air according to the operating state is The valve closing position control is executed. The intake valve closing position control 1 and the intake valve closing control 2 will be described later in detail by using the subroutines of FIGS. 5 and 6.

Next, using the flowchart of FIG.
The air-fuel ratio control program according to the present embodiment will be described. This program is a program that is started every 180 ° CA, for example, in synchronization with the rotation of the crankshaft 31. First, in step S501, as the start determination of the internal combustion engine, it is determined whether the engine rotation speed Ne is, for example, 400 rpm or more. here,
When it is determined that the engine rotation speed Ne is 400 rpm or less, this program is not executed and the process ends. On the other hand, when the engine rotation speed Ne is 400 rpm or more, the process proceeds to step S502. Step S50
2, the operating conditions include, for example, the engine cooling water temperature Thw detected by the water temperature sensor 3, the engine rotation speed Ne,
The intake pressure Pm detected by the intake pressure sensor 6 (an intake air amount sensor may be separately provided to detect the intake air amount Ga) and the like are read.

Then, in step S503, it is determined whether or not the first idle execution condition is satisfied. The first / idle execution condition may be the same as that in step S200 of the flowchart of FIG. Here, when the execution condition is not satisfied, the target air-fuel ratio is set based on the operating condition. As the setting of this target air-fuel ratio, a conventionally known method may be used and the air-fuel ratio may be set according to the operating region. For example, the air-fuel ratio may be set to lean in a low load region such as during steady running, and the air-fuel ratio may be set to rich in an operating state such as a transient state to improve torque. In this way, in the operating region other than the fast idle, the routine is finished by the conventionally known method of setting the target air-fuel ratio.

On the other hand, in step S503, first
If the idle execution condition is satisfied, step S50
Go to 4. In step S504, the target air-fuel ratio is set to weak lean. This is for the purpose of reducing emissions at the time of starting and is for reducing the fuel injection amount. Next, in step S505, it is determined whether the engine rotation speed Ne is stable. The reason for determining the stability of the engine rotation speed Ne is that the air-fuel ratio is controlled to be lean and that the torque fluctuation is likely to occur due to the retardation of the ignition timing, which will be described later, which may worsen the drivability. is there. Here, as a method for determining whether the engine rotation speed Ne is stable, as shown in FIG. 9A, there is a determination value indicating that the engine rotation speed Ne is not stable according to the engine rotation speed Ne. It is determined that the rotation speed Ne is not stable depending on whether the deviation ΔNe of the rotation speed Ne according to the rotation speed Ne is larger than the determination value. Incidentally, this determination value becomes larger as the engine rotation speed Ne is higher.

As another method, as shown in FIG. 9B, the engine torque fluctuation is detected, and the engine rotation speed Ne, the torque fluctuation, and the same judgment value as in FIG. 9A are detected. It may be determined based on the engine speed Ne that the engine speed Ne is not stable.

Thus, in step S505,
When the engine rotation speed Ne is stable, the target air-fuel ratio set in step S504 is ended, and this routine is ended with the target lean air-fuel ratio. On the other hand, if it is determined in step S505 that the engine rotation speed Ne is unstable, the process proceeds to step S506 and step S506.
The weak lean target air-fuel ratio set in 504 is changed to a weak rich air-fuel ratio, and this routine is ended. in this way,
When the operation of the internal combustion engine is controlled by the lean air-fuel ratio, and when the ignition timing retard control for the catalyst early warm-up described later is being executed, the rotation speed Ne is likely to become unstable. The rotation speed Ne is stabilized by setting the air-fuel ratio to be slightly rich.

Next, the ignition timing control of this embodiment will be described with reference to the flowchart of FIG. This ignition timing control program calculates the ignition timing according to the operating condition when the fast / idle execution condition is not satisfied, and delays the ignition timing to retard the internal combustion engine when the fast / idle execution condition is satisfied. Slow down the combustion,
This is a control for promptly raising the temperature of the catalyst by supplying high temperature exhaust gas to the catalyst.

Note that this program is a program that is started, for example, every 180 ° CA in synchronization with the rotation of the crankshaft 31. First, in step S501, the engine speed N is determined as the start determination of the internal combustion engine.
For example, it is determined whether e is 400 rpm or more. Here, if it is determined that the engine rotation speed Ne is 400 rpm or less, the program is not executed and the process ends. On the other hand, the engine speed Ne is 400r
If it is pm or more, the process proceeds to step S512. In step S512, as operating conditions, for example, the engine cooling water temperature Thw detected by the water temperature sensor 3, the engine rotation speed Ne, and the intake pressure Pm detected by the intake pressure sensor 6 are used.
(An intake air amount sensor may be separately provided to detect the intake air amount Ga.) And the like are read. Then, step S513
Then, the first idle execution condition is determined. The execution condition of the first idle is the same condition as step S200 in FIG.

If the execution condition is not satisfied,
In step S517, the ignition timing is calculated based on the operating conditions read in step S512. The calculation of the ignition timing in this step may be performed by a method well known in the art, and the engine rotation speed Ne and the intake pressure P of the internal combustion engine may be calculated.
The ignition timing may be set by a map or the like based on m (or the intake air amount Ga). As described above, in the operation other than the fast idle, the normal ignition timing is set by the map or the like, and the present routine is finished.

On the other hand, when the fast idle execution condition of step S513 is satisfied, step S514
Then, the ignition timing retard control for early catalyst warm-up is executed. By retarding the ignition timing from the normal ignition timing by, for example, about 10 ° CA, the combustion in the internal combustion engine 1 is slowed down, and the high temperature exhaust gas is positively discharged into the exhaust pipe, whereby the catalyst Promote temperature rise. Then, in step S515, the following condition determination is performed. The condition is whether the engine rotation speed Ne is stable or the engine rotation speed Ne is stable (the same determination as in step S505 of the flowchart in FIG. 4), and whether the weak rich control is being performed as the air-fuel ratio control. is there. When this condition is not established, this routine is finished as it is. On the other hand, when the above condition is satisfied, the fluctuation of the rotation speed Ne cannot be suppressed even though the air-fuel ratio is made slightly rich. Therefore, the routine proceeds to step S506, where the ignition timing is advanced to stabilize the combustion. Control is performed.

As described above, in the air-fuel ratio control program and the ignition timing control program, when it is determined that the execution conditions are the fast idle execution conditions, the ignition timing retard control for the catalyst early warm-up is executed. The air-fuel ratio is set to be slightly lean and the air-fuel ratio is controlled to reduce emissions. At this time, the stability of the engine rotation speed Ne is determined based on the engine rotation speed Ne and ΔNe.
At this time, when a rotation fluctuation that deteriorates the drivability occurs, first, the rotation fluctuation is suppressed by performing the air-fuel ratio weak enrichment control. Further, when the rotation fluctuation cannot be suppressed by the weak enrichment control of the air-fuel ratio, the ignition timing advance control is performed to stabilize the combustion. This is because priority is given to the early temperature rise of the catalyst.

Next, as a subroutine of step S300 in FIG. 2, the program of the intake valve closing position control 1 will be described in detail with reference to the flowchart of FIG. This program is a subroutine that is activated when the process of step S300 in FIG. 2 is performed. First, in step S301, the engine cooling water temperature Thw detected by the water temperature sensor 3, the engine rotation speed Ne, and the intake pressure Pm detected by the intake pressure sensor 6 are set as operating conditions.
(An intake air amount sensor may be separately provided to detect the intake air amount Ga.) And the like are read. Then, the target intake valve closed position (VTcl1) is calculated based on the detected operating condition. As a calculation method, VTcl1 is read from the engine rotation speed Ne and the intake pressure Pm using the map of FIG. Since the target intake valve closed position VTcl1 at this time is in the fast idle, the intake valve closed position VTcl1 is retarded as compared with the steady operation in FIG. 11B as shown in FIG. 11A. Set on the side. Since the map of FIG. 7 is similar to the map used in the flowchart of FIG. 6, here, 1 corresponds to the symbol * of VTcl * in FIG. 7.

When the target intake valve open position VTcl1 is calculated, the routine proceeds to step S303, where it is judged if the brake is on. If it is determined that the brake is on, then the flow proceeds to step S304. In step S304, it is determined whether the pressure Pm in the intake pipe detected by the intake pressure sensor 3 is more positive than the predetermined negative pressure 1. If it is determined that the pressure is on the negative pressure side of the predetermined negative pressure 1, the process proceeds to step S309, the previous control intake valve position VTRcl is input to the current control intake valve position VTRcl (n), and this routine is ended. . On the other hand, in step S304, when the intake pressure Pm is on the positive pressure side of the predetermined negative pressure 1, the process proceeds to step S305 and subsequent steps, and a process for setting the pressure in the intake pipe to the negative pressure side of the predetermined negative pressure 1 is performed. carry out.

In step S305, the advance amount θ1 of the intake valve closed position is calculated. Here, the advance angle θ1 may be a fixed value or may be variably set according to the ignition timing as shown in the map shown in FIG. In the map of FIG. 10A, the advance amount θ1 is set according to the ignition timing, and the larger the ignition timing is, the larger the advance amount is set.
Further, in the map of FIG. 10B, the advance amount θ1 of the intake valve closed position is set based on the retard amount of the ignition timing with respect to the normal control position. In this map, the larger the retard amount of the ignition timing is, the larger the advance amount θ1 is set. That is, in the map of FIG. 10, the larger the retard amount of the ignition timing is, the more the combustion torque becomes insufficient. Therefore, in order to maintain the target rotation speed at the time of the first idle, the intake air amount is increased to eliminate the torque shortage. try to. Therefore, the amount of intake air in the intake pipe increases, and the pressure in the intake pipe tends to become more positive than the predetermined negative pressure.Therefore, when the ignition timing retard amount is large, the intake valve closed position advance amount is set to a large value. Good to do.

In this way, the advance amount θ of the intake valve closed position
When 1 is set, the process proceeds to step S306. Step S
At 306, the previous value VTRcl (n of the control intake valve closed position)
The predetermined value α1 is added to -1), and the process proceeds to step S307. In step S307, it is determined whether or not the control intake valve closed position this time exceeds the target intake valve closed position VTcl plus the advance amount θ1 calculated in step S305. Here, if the value does not exceed the value obtained by adding the advance amount θ1 to the target intake valve closed position VTcl, this routine is finished as it is. On the other hand, if it is determined that the control intake valve closed position VTRcl exceeds the value obtained by adding the advance amount θ1 to the target intake valve closed position VTcl, the process proceeds to step S308, and the target intake valve closed position VTRcl (n) is set to the target intake valve closed position VTRcl (n). A value obtained by adding the advance amount θ1 to the closed position VTcl is input, and this routine is ended.

On the other hand, if it is determined in step S303 that the brake is not on, the process proceeds to step S310 and the subsequent steps. In step S310, first, it is determined whether or not it is immediately after the brake is switched from on to off. Here, when it is determined that it is immediately after the brake is switched from on to off, the counter C is set to a predetermined value in step S311. The counter C controls the control intake valve closed position VTR set in step S308 or step S309 for a predetermined period after the brake is turned off.
It is a counter for maintaining cl (n-1). When the counter C is set to the predetermined value, the process proceeds to step S312, and the control intake valve closing position VTRcl (n) is set as the previous value VTRcl (n-1) of the control intake valve closing position VTRcl.
Is set and this routine ends.

After the brake is switched from on to off, it is determined in step S310 that the brake is off, and the process proceeds to step S314. Step S31
In step 4, the counter C is decremented and step S
Proceed to 314. In step S314, the predetermined value α2 is subtracted from the control intake valve closed position VTRcl, and then step S31
Go to 5. In step S315, it is determined whether the counter C has reached 0. By this determination, the counter C is 0
If not, the process proceeds to step S312, and the control intake valve closing position VTRcl (n) is set as the control intake valve closing position V.
The previous value VTRcl (n-1) of TRcl is set, and this routine ends. On the other hand, when the counter C has reached 0, the process proceeds to step S317, and the target intake valve closed position VT
cl is compared with the control intake valve closed position VTRcl (n). Here, if the control valve closing position VTRcl (n) calculated in step S314 is larger, the present routine is ended as it is, and if the target intake valve closing position VTRcl is larger, the control valve closing this time is performed. Position VTRcl
The target intake valve closed position VTcl is set in (n), and this routine is ended.

Next, the subroutine of step S400 in FIG. 2, that is, the intake valve closing position control 2 will be described in detail with reference to the flowchart shown in FIG. This program is for the intake valve 3 when the first idle execution condition is not satisfied.
In the period from the start determination of the internal combustion engine is performed until the first idle execution condition is satisfied, the target intake valve closed position set according to the operating condition is advanced to advance the internal control of the intake pipe. The pressure is maintained at a predetermined negative pressure of 2 or less. On the other hand, when the conditions are other than the above conditions, the control is to set the target intake valve closed position that is set according to the operating conditions. Note that this program is a subroutine that is activated when the process of step S400 in FIG. 2 is performed.

First, in step S401, as operating conditions, for example, the engine cooling water temperature Thw detected by the water temperature sensor 3, the engine rotation speed Ne, and the intake pressure Pm detected by the intake pressure sensor 6 (an intake amount sensor is separately provided). hand,
The intake air amount Ga may be detected. ) Etc. are read. Then, in step S402, the target intake valve closed position (VTcl1) is calculated based on the detected operating condition. As a calculation method, VTcl1 is read from the engine rotation speed Ne and the intake pressure Pm using the map of FIG. Note that the map of FIG. 7 is similar to the map used in the flowchart of FIG. 5, so here the VT in FIG.
The symbol * of cl * corresponds to 2.

When the target intake valve open position VTcl2 is calculated, the routine proceeds to step S403, where it is judged if a predetermined period has elapsed from the start judgment of the internal combustion engine. Here, if it is determined that the predetermined period has not elapsed from the start determination,
It proceeds to step S404. In step S404, it is determined whether the pressure Pm in the intake pipe detected by the intake pressure sensor 3 is more positive than the predetermined negative pressure 2. Here, if it is determined that the pressure is on the negative pressure side of the predetermined negative pressure 2, the process proceeds to step S409, and the control intake valve position VTRcl of this time.
The previous control intake valve position VTRcl (n-1) is input to (n) and this routine ends. On the other hand, step S40
In 4, when the intake pressure Pm is on the positive pressure side of the predetermined negative pressure 2, the processing proceeds to step S405 and subsequent steps, and processing for making the pressure in the intake pipe lower than the predetermined negative pressure 2 is performed.

In step S405, the advance amount θ2 of the intake valve closed position is calculated. Here, in the flowchart of FIG. 5, the advance amount θ of the intake valve closed position is set according to the retard amount of the ignition timing.
2 was variably set, but since this program is the control that is performed between the start determination and the start of the first idle execution, the advance angle θ2 based on the ignition timing.
Need not be set.

In this way, the advance angle θ of the intake valve closed position
When 2 is set, the process proceeds to step S406. Step S
At 406, the previous value VTRcl (n of the control intake valve closed position)
The predetermined value α3 is added to -1), and the process proceeds to step S407. In step S407, it is determined whether or not the current control intake valve closed position exceeds the target intake valve closed position VTcl2 plus the advance amount θ1 calculated in step S405. Here, the target intake valve closed position VTcl2 is advanced to the advancing amount θ2.
If it does not exceed the value obtained by adding, the present routine is terminated. On the other hand, if it is determined that the control intake valve closed position VTRcl exceeds the value obtained by adding the advance amount θ2 to the target intake valve closed position VTcl, the process proceeds to step S308, and the control intake valve closed position VTRcl (n) is set to the target intake valve closed position VTRcl (n). Closed position VTcl
A value obtained by adding the advance angle θ2 is input to and the present routine ends.

On the other hand, when it is determined in step S403 that the predetermined period has elapsed from the start determination of the internal combustion engine, the target intake valve closed position VTcl2 is compared with the control intake valve closed position VTRcl in step S410. Here, if it is determined that the target intake valve closed position VTcl2 is smaller,
It proceeds to step S411. In step S411, a value obtained by subtracting the predetermined value α4 from the previous (n-1) of the control intake valve closed position VTRcl (n) is set to the control intake valve closed position VTRc of this time.
This is set as l (n) and this routine ends. on the other hand,
When the target intake valve closed position VTcl2 is larger than the control intake valve closed position VTRcl, the target intake valve closed position VTcl is set as the current value of the control intake valve closed position VTRcl.
Is set and this routine ends.

A time chart of the present embodiment performed according to the above processing procedure will be described with reference to FIGS. 11 and 12. FIG. 12A shows the engine rotation speed Ne. As the start determination of the internal combustion engine, for example, 400 rp
After exceeding m, the pressure in the intake pipe shown in FIG.
When it is on the positive pressure side of the predetermined pressure 2 shown by the alternate long and short dash line in the same figure, the target intake valve closed position VTcl is set to a value advanced from the normal intake valve closed position. Since the actual intake valve 32 is controlled by the control intake valve closed position VTRcl (n), when the target intake valve closed position is switched, it gradually follows the target intake valve closed position VTcl2 (by a predetermined value).

As described above, in the present embodiment, the intake pipe internal pressure is the predetermined negative pressure 2 during the period from the start determination until the intake pipe internal pressure becomes the predetermined negative pressure 2 and the first idle execution condition is satisfied. The intake valve closed position VTcl is advanced by a predetermined advance amount θ2 so as to be on the negative pressure side.
Then, at the point A in FIG. 12, if the above conditions (1) to (4) are satisfied as the execution conditions of the first idle,
As shown in FIG. 12 (b), ignition timing retard control for early catalyst warm-up is executed. At this time, as shown by point A in FIGS.
By retarding from the steady running state of 1 (b), a differential pressure is generated between the intake pipe and the combustion chamber before the intake valve 32 opens, and the intake flow velocity of the air flowing into the combustion chamber is improved.
Since the intake flow velocity is improved, the air-fuel ratio can be made weaker lean, and the fuel injection amount is reduced and corrected for the air-fuel ratio weak lean control.

However, if the intake valve 32 is retarded as shown in FIG. 11 (a), the intake valve 3 will be exceeded even if the bottom dead center BDC is exceeded.
2 becomes long, the intake air once supplied to the combustion chamber is blown back to the intake pipe,
As shown from point A onward in (e), the intake pipe pressure becomes more positive than the predetermined negative pressure. Here, B in FIG.
If the intake valve closed position is left in the retard position when the brake is turned on by the driver as shown by the point, the intake pipe internal pressure Pm becomes a predetermined negative pressure as in the prior art shown in FIG. Since it is on the positive pressure side rather than 1, B in FIG.
As shown after the point, the negative pressure in the brake tank is consumed. As described above, by retarding the closed position of the intake valve 32 during the early warm-up of the catalyst, the pressure Pm in the intake pipe becomes greater than the predetermined negative pressure 1, so that the brake is used once. Then, the inside of the brake tank does not reach a predetermined negative pressure, and a large pedal force is required when the driver uses the brake next time.

However, in this embodiment, as shown in FIG.
As shown in (c) and point B of FIG. 12 (d), the intake valve 32
By advancing the closed position of the engine from the closed position at the time of first idle, it is possible to prevent the intake air once supplied to the combustion chamber from being blown back into the intake pipe. A pressure on the negative pressure side of the pressure can be introduced. Then, at the point C in FIG. 12C, the pressure in the brake tank is set to a predetermined value by holding the intake valve closed position at the advanced position for a predetermined period from the brake being turned off to the point C in the figure. The pressure is set on the negative pressure side rather than the negative pressure, and the intake valve closed position is returned to the original position at point D in the figure. As a result, the intake pipe pressure Pm from point B to point D in FIG. 12 (e) can be maintained at a value on the negative pressure side than the predetermined negative pressure 1, and as shown in FIG. The pressure of can be kept negative at all times.

At this time, since the overlap amount is increased by advancing the intake valve closed position, the amount of combustion gas remaining in the combustion chamber (hereinafter, the amount of internal EGR gas) may increase. However, in the present embodiment, considering the stability of combustion based on the engine rotation speed Ne,
When the combustion becomes unstable, the stability of the combustion is restored by weakly enriching the air-fuel ratio. Further, the ignition timing is advanced to restore the combustion stability only when the combustion stability cannot be restored by only weakening the air-fuel ratio. In this way, when there is concern about deterioration of combustion, priority is given to weak enrichment control of the air-fuel ratio,
The early warm-up of the catalyst by the ignition timing retard control is continued. Therefore, even if the combustion becomes unstable, within the range where the stability of the combustion can be restored by the weak enrichment control of the air-fuel ratio,
Since the early warm-up of the catalyst is not stopped, the temperature of the catalyst can be raised early and the deterioration of combustion can be suppressed.

As described above, in the present embodiment, the pressure on the negative pressure side of the predetermined negative pressure in the brake tank is always maintained in response to the driver's brake request without providing a sensor for detecting the pressure in the brake tank. Therefore, it is possible to prevent the driver from feeling uncomfortable when using the brake. Further, the intake valve closed position is advanced only when it is necessary to introduce a negative pressure into the brake tank according to the on / off state of the brake, so that the intake pipe internal pressure Pm is unnecessarily set to a negative pressure. Is suppressed.

In this embodiment, the advance angle amount θ1 / predetermined negative pressure 1 used in the intake valve closed position control 1 and the advance angle amount θ2 / predetermined negative pressure used in the intake valve closed position control 2 are used. Although 2 is a different value, the same value may be used. Also,
Advancement angle θ1 ・ θ set by intake valve closing position control 1.2
Predetermined values α1 and α3 for gradually advancing with respect to 2
May be the same as the predetermined values α2 and α4 for gradually retarding.

In the present embodiment, the first advance angle control means is shown in the flow chart of FIG. 5, the second advance angle control means is shown in the flow chart of FIG. 6, and the intake air amount control means is set to the target rotation in the idle operation state. The means for controlling the intake air amount by adjusting the throttle valve in order to make the rotation speed follow the rotation speed, the ignition timing control means in the flow chart of FIG. 4, the pressure detection means in the intake pressure sensor 6, and the rotation speed detection means in the rotation speed detection means. The crank angle sensor 2 and the engine water temperature detecting means are the water temperature sensor 3
In addition, the intake air temperature detecting means is a temperature sensor (not shown) provided in the intake pressure sensor 6, the combustion state detecting means is step S505 of FIG. 3 and step S515 of FIG. 4, and the air-fuel ratio weak rich control means is the step of FIG. In step S506, the ignition timing advance control means executes step S5 in the flowchart of FIG.
The retard control means corresponds to means for retarding the intake valve closing position so that the valve overlap amount is reduced when it is detected that combustion has become unstable due to the advance of the intake valve. ,Function.

<Second Embodiment> In the first embodiment, when the brake is turned on as the brake operation state, the closed position of the intake valve 32 is advanced to set the pressure in the intake pipe to a predetermined value. Although the negative pressure was maintained, in the present embodiment, the negative pressure is consumed during the use of the brake, and the driver does not need a large stepping force. , Implement control so that the feeling of use of the brake does not deteriorate.

In the present embodiment, as the intake valve closed position control performed according to the operation state of the brake, a control which replaces the intake valve closed position control 1 of the first embodiment will be described. Hereinafter, a detailed description will be given with reference to the flowchart of FIG.
The program of FIG. 13 is the intake valve closed position control 1, and the same processing steps as those in the first embodiment are designated by the same reference numerals and the description thereof will be omitted. This program is a program that is started every 180 ° CA, for example, in synchronization with the rotation of the crankshaft 31.

First, in step S301, the operating condition is read, and in step S302, the target intake valve closed position VTcl1 corresponding to the operating condition is calculated. Then, in step S601, it is determined whether or not a brake flag Fb, which will be described later, is 1 as a flag indicating the operation state of the brake. If the brake flag Fb is not 1, this routine ends. On the other hand, when the brake flag Fb is 1, the process proceeds to step S602. Here, the brake flag Fb is a flag that is held at 1 after the brake is switched from on to off until a predetermined period set later is ended, and this predetermined period is step S602.
It is set to execute the process of.

In step S602, a predetermined value is set in the counter C in order to set a predetermined period for carrying out the following processing. Then, in step S603, the counter C is decremented and the process proceeds to step S304. In step S304, it is determined whether the pressure in the intake pipe is smaller than the predetermined value 1. That is, it is determined whether the pressure in the intake pipe is the positive pressure side or the negative pressure side with respect to the predetermined negative pressure. If it is on the positive pressure side of the predetermined negative pressure, step S305
~ As the process of step S308, the advance control of the intake valve 32 is performed, and this routine ends. This process is repeatedly performed until the pressure in the intake pipe is closer to the negative pressure side than the predetermined negative pressure. Then, when the intake valve position VTRcl advances by the target advance amount θ1, it is maintained at that opening.

On the other hand, if the intake negative pressure Pm is on the negative pressure side with respect to the predetermined negative pressure, the counter C is counted at step S604.
Is determined to be less than 0. When the counter C is greater than 0, in order to maintain the negative pressure in the intake pipe, in step S312, the previous intake valve closed position VTRcl (n
-1) is set to the intake valve closing position VTR (n) of this time, and this routine is finished. When the counter C has a value smaller than 0, the negative pressure tank is filled with a desired negative pressure, and therefore the intake valve closed position VTRcl is set to the target intake valve closed position VTcl1 by the processing of step S314 and thereafter. To gradually retard.

As described above, in the present embodiment, during the predetermined period after the brake is switched from ON to OFF,
Since the control for introducing a desired negative pressure to the negative pressure tank is performed, a large pedaling force is not required when the driver uses the brake next time. Therefore, also in the present embodiment, the intake pipe pressure can be maintained at a negative pressure only when a negative pressure is required in the brake tank without providing a pressure sensor in the brake tank, so that, for example, pumping loss can be suppressed. Therefore, retardation control of the intake valve closing position for improving combustion can be appropriately performed.

In the present embodiment, the first advance angle control means corresponds to the flowchart of FIG. 13 and functions.

(Other Embodiments) In the present embodiment, intake is performed when a valve timing mechanism having a conventionally known opening / closing timing and lift or a mechanism for varying the working angle is adopted as the valve timing mechanism. The valve closing position control will be described. As such a valve timing mechanism, for example, an electromagnetically driven intake / exhaust valve valve timing mechanism is known.

Generally, an electromagnetically driven intake / exhaust valve (not shown) sucks an armature provided in the middle of the intake valve or exhaust valve shaft by energizing an electromagnetic core equipped with a solenoid. As a result, the open / close position of the intake valve or the exhaust valve can be set independently and arbitrarily. In other words, by freely setting the open / close position and its working angle, optimum intake / exhaust can be achieved according to the operating conditions.

This embodiment will be described with reference to the time chart of FIG. As described in the first embodiment and the second embodiment, in the first embodiment and the second embodiment, the intake valve closed position is controlled according to the operating state of the brake. In this embodiment, a method of controlling the intake valve position of the intake valve position when a valve timing mechanism capable of changing the lift amount and / or the working angle is used will be described. First, according to the time chart of FIG. 14, the opening / closing position of the intake valve shown by the dotted line in the figure is the value when the ignition timing retard control is performed as the catalyst early warm-up under the fast idle execution condition. The amount of lift and the open / close position are shown. At this time, as in the first embodiment or the second embodiment, the intake valve is controlled according to the operating state of the brake as shown by the solid line in the figure. According to FIG. 14, the air blown back into the intake pipe is reduced by advancing the position of the intake valve relative to BDC. At this time, a period in which the intake valve open position is opened simultaneously with the exhaust valve, that is, a so-called overlap amount is considered. That is, since the amount of combustion gas remaining in the combustion chamber increases as the overlap amount increases, combustion becomes unstable. Therefore, in the open position of the intake valve, stable combustion can be realized by eliminating the overlap amount in order to prevent the combustion from becoming unstable. Note that the intake air amount decreases as the intake valve open position and close position approach each other, but as a countermeasure against this, the intake air amount is decreased by increasing the intake valve lift amount as shown in the figure. Can be prevented.

In the present embodiment, the electromagnetically driven intake / exhaust valve has been described as an example. However, in the case where only the open / close position of the intake valve can be variably set, the open position is to reduce the combustion gas remaining in the combustion chamber. It can be set for the purpose. Further, the lift amount may be increased for the purpose of reducing the pressure in the intake pipe by increasing the intake air amount.

In the present embodiment, the lift amount control means is used to prevent the combustion from becoming unstable due to the decrease in the intake air amount, or the pressure in the intake pipe is increased by increasing the intake air amount. It is used as a means to reduce.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram according to the present embodiment.

FIG. 2 is a main routine according to the first embodiment.

FIG. 3 is a flowchart showing air-fuel ratio control according to the first embodiment.

FIG. 4 is a flowchart showing ignition timing control according to the first embodiment.

FIG. 5 is a flowchart showing intake valve closed position control performed based on a brake state according to the first embodiment.

FIG. 6 is a flowchart showing the intake valve closed position control from the time of starting according to the first embodiment.

FIG. 7 is a map for calculating an intake valve closed position based on a rotation speed and an intake pipe pressure.

FIG. 8 is a map for setting the closed position of the intake valve based on the pressure in the intake pipe.

FIG. 9 is a map for determining combustion stability based on rotation fluctuations according to rotation speed.

FIG. 10 is a map for setting the advance amount according to the ignition timing.

FIG. 11 is a time chart for explaining the intake valve closed position for each operating state.

FIG. 12 is a time chart for explaining the first embodiment.

FIG. 13 is a program showing the intake valve closing position control according to the second embodiment.

FIG. 14 is a time chart showing intake valve closed position control according to another embodiment.

[Explanation of symbols]

1 ... internal combustion engine, 3 ... Water temperature sensor, 5 ... Throttle opening sensor, 6 ... Intake pressure sensor, 7 ... Oil temperature sensor, 8 ... accelerator sensor, 9 ... OCV, 10 ... Valve timing mechanism, 14 ... Throttle valve, 20 ... ECU, 32 ... Intake valve.

─────────────────────────────────────────────────── ─── Continued Front Page (51) Int.Cl. ⁷ Identification Code FI Theme Coat (Reference) F02D 13/02 F02D 13/02 J 3G301 41/04 305 41/04 305A 320 320 41/06 320 41/06 320 43/00 301 43/00 301B 301Z 45/00 362 45/00 362J F02P 5/15 F02P 5/15 F EF Term (Reference) 3G018 AB02 AB17 BA34 CA06 CA19 DA75 EA02 EA09 EA11 EA17 EA21 EA26 EA31 EA32 EA32 EA33 EA33 EA32 EA33 EA33 EA33 EA33 EA33 EA33 EA33 FA01 FA07 GA01 GA03 GA12 GA14 3G022 CA01 CA02 CA05 DA01 DA02 GA01 GA05 GA08 GA09 GA20 3G084 BA17 BA23 CA01 CA02 DA04 DA05 DA13 EB11 FA06 FA10 FA20 FA33 FA34 FA38 3G092 AA01 AA11 BA02 BA02 BA04 BA09 DA01 DA08 DA10 DD03 EA01 EA02 DD04 EA01 EA02 FA03 FA04 FA06 FA15 FA34 GA01 GA02 GA13 HA04Z HA05Z HA06Z HA13X HA13Z HE01Z HE03Z HE05Z HE08Z HF08Z HF25Z 3G09 3 AA01 AA05 BA03 BA14 BA15 CA01 CA02 CB07 DA01 DA05 DA06 DA07 DB15 EC04 FA04 FB01 FB02 FB03 FB07 3G301 HA01 HA19 JA03 JA04 JA20 KA01 KA02 LA07 MA01 NC02 ND01 NE01 NE06 NE11 NE12 NE13 PA07Z PA10Z PA10 PE09 PE05 PE05 PE05 PE05 PE05 PE05 PE05 PE05

Claims (15)

[Claims] 1. A variable intake valve timing mechanism that variably sets a relative position of an intake valve with respect to a crankshaft of an internal combustion engine, calculates a closed position of the intake valve according to an operating state of the internal combustion engine, and performs this calculation. In a valve timing control device for an internal combustion engine that controls a closed position of the intake valve based on a result, when the closed position of the intake valve is retarded from a bottom dead center, based on an operating state of a brake, A valve timing control device for an internal combustion engine, comprising: first advance control means for advancing a closed position of an intake valve. 2. A target rotation speed setting means for setting a target rotation speed of an internal combustion engine, and a throttle valve is opened to increase an intake air amount so that the target rotation speed is reached when the rotation speed is lowered. Intake air amount control means for controlling the rotation speed,
A catalytic converter provided in the exhaust pipe, ignition timing control means for controlling the ignition timing according to the operating state of the internal combustion engine, and variable intake valve timing for variably setting the relative position of the intake valve with respect to the crankshaft of the internal combustion engine. A valve timing control device for an internal combustion engine, comprising: a mechanism for calculating a closed position of the intake valve according to an operating state of the internal combustion engine, and controlling the closed position of the intake valve based on a result of the calculation. The control means is configured to include means for retarding the ignition timing with respect to the ignition timing set based on a normal operating state in order to quickly raise the temperature of the catalytic converter when the internal combustion engine is cold started. A first advance for advancing the closed position of the intake valve based on the operation state of the brake when the closed position of the intake valve is retarded from the bottom dead center. The valve timing control apparatus for an internal combustion engine, characterized by a control unit. 3. The closing position of the intake valve based on an ignition timing by the ignition timing control means or a retard amount when the ignition timing is retarded. 4. The amount of advance angle is set.
A valve timing control device for an internal combustion engine according to item 1. 4. The pressure detecting means for detecting the pressure in the intake pipe of the internal combustion engine, wherein the first advance control means is such that the pressure in the intake pipe detected by the pressure detecting means is lower than a predetermined negative pressure. When the positive pressure side is also on the positive pressure side, the closed position of the intake valve is advanced based on the operating state of the brake.
The valve timing control device for an internal combustion engine according to claim 3. 5. The first advance control means sets the advance amount of the closed position of the intake valve based on the pressure detected by the pressure detection means.
A valve timing control device for an internal combustion engine according to item 1. 6. The first advance control means advances the closed position of the intake valve when the brake is turned on,
The advance of the closed position of the intake valve is ended after a predetermined period of time after the brake is turned off.
A valve timing control device for an internal combustion engine according to claim 5. 7. The first advance control means advances the closed position of the intake valve to a position where a piston provided in the internal combustion engine is near bottom dead center. The valve timing control device for an internal combustion engine according to claim 6. 8. The first advance control means advances the closed position of the intake valve so that a period in which the exhaust valve and the intake valve are simultaneously opened is a predetermined period or less. The valve timing control device for an internal combustion engine according to claim 1. 9. The first advance angle control means advances the closed position of the intake valve based on the state of the brake when a predetermined condition is satisfied. Item 9. A valve timing control device for an internal combustion engine according to any one of items 8. 10. A rotation speed detecting means for detecting a rotation speed of the internal combustion engine is provided, wherein the predetermined condition is a state of the brake when the rotation speed detected by the rotation speed detecting means is equal to or lower than a predetermined rotation speed. 10. The valve timing control device for an internal combustion engine according to claim 9, wherein the closing position of the intake valve is advanced based on the above. 11. An engine water temperature detecting means for detecting a cooling water temperature of the internal combustion engine, and / or an intake air temperature detecting means for detecting an intake air temperature sucked into a combustion chamber of the internal combustion engine, wherein the predetermined condition is: 11. The valve timing control device for an internal combustion engine according to claim 9, wherein the cooling water temperature and / or the intake air temperature is equal to or higher than a predetermined temperature. 12. A second advance control means for advancing the closed position of the intake valve after the internal combustion engine is started and before the ignition timing is retarded by the ignition timing control means. The valve timing control device for an internal combustion engine according to claim 2, wherein the valve timing control device is an internal combustion engine valve timing control device. 13. A combustion state detecting means for detecting a combustion state of an internal combustion engine, wherein the first advance angle control means is provided when the combustion state detected by the combustion state detecting means is stable. The valve timing control device for an internal combustion engine according to any one of claims 1 to 12, wherein the closed position of the intake valve is advanced based on the braking state. 14. The combustion state detecting means detects the combustion state of the internal combustion engine on the basis of a rotational speed variation or a torque variation of the internal combustion engine.
The valve timing control device for an internal combustion engine according to item 3. 15. A combustion stabilizing means for stabilizing combustion when the combustion state detected by the combustion state detecting means is unstable, wherein the stabilizing means determines an air-fuel ratio by combustion of an internal combustion engine. Air-fuel ratio weak rich control means for controlling to a weak rich, ignition timing advance control means for advancing the ignition timing of the internal combustion engine by a predetermined amount,
Retardation control means for retarding the closed position of the intake valve,
The intake valve lift amount control means for controlling the lift amount of the intake valve to be increased, and at least one of them is provided to stabilize combustion of the internal combustion engine. 15. The valve timing control device for an internal combustion engine according to any one of 14.