JP4479689B2 - Control device for internal combustion engine - Google Patents

Description

  The present invention relates to a control device for an internal combustion engine including an intake flow control valve that generates in-cylinder flow in a combustion chamber and variable valve means that can vary the overlap period of the intake and exhaust valves.

  A technique is known in which an intake air flow intake flow path is provided in an intake flow path leading to a combustion chamber of an internal combustion engine so as to be freely opened and closed separately from a throttle valve for controlling the intake air amount. The intake flow control valve is provided so as to generate in-cylinder flow such as a tumble flow or a swirl flow in the combustion chamber by operating in the direction of narrowing the intake flow passage area. This intake flow control valve is operated when the in-cylinder flow is weak and combustion tends to become unstable, such as when the engine is idling or partial after starting, and the in-cylinder flow is strengthened to improve the stability of the combustion. It is improving. Patent document 1 is mentioned as a well-known example which reinforces in-cylinder flow using such an intake flow control valve. In Patent Document 1, an intake flow control valve is operated when starting an internal combustion engine.

JP-A-9-112283

  If the valve overlap amount can be increased by using variable valve means that can change the opening and closing timing of the intake and exhaust valves when the internal combustion engine is cold-started, the internal EGR amount increases and the exhaust gas is discharged from the internal combustion engine. It is possible to reduce harmful components in exhaust gas. However, during idling in cold conditions, combustion fluctuations are large, and if the valve overlap amount is increased to easily increase the internal EGR amount, the combustion becomes unstable and causes vibration and misfire. In view of this, it is difficult to increase the valve overlap amount, and it is difficult to reduce exhaust gas.

  Therefore, it is conceivable to add an intake flow control valve to an internal combustion engine equipped with variable valve means and operate it at the time of starting to enhance the in-cylinder flow in the combustion chamber to improve combustion stability. It is difficult to improve exhaust gas purification performance while obtaining drivability simply by providing the means and the configuration of the intake flow control valve. That is, the increase in the internal EGR amount due to the operation of the variable valve means makes combustion unstable, and the generation of the in-cylinder flow due to the operation of the intake flow control valve promotes combustion. For this reason, in order to improve drivability and exhaust gas performance, the operation order and stop order of both are very important elements. Even if the order of the operation and stop of each means is determined, these are mechanical structures, so it is necessary to take into account such things as operation delay and failure.

  An object of the present invention is to provide a control device for an internal combustion engine that can reduce exhaust gas while obtaining drivability by using variable valve means and an intake flow control valve.

In order to achieve the above-mentioned object, the invention of claim 1 is provided in an open air passage in the combustion chamber of the internal combustion engine through an intake port so as to be openable and closable. Both the intake valve and the exhaust valve are in an open state by changing the opening / closing timing of at least one of an intake flow control valve that causes in-cylinder flow, an intake valve that opens and closes the intake port, and an exhaust valve that opens and closes the exhaust port. Variable valve means for changing the valve overlap period, adjustment valve operation determination means for determining the operation state of the intake flow rate adjustment valve, start determination means for determining the start state of the internal combustion engine, intake flow control valve, and the variable Control means for controlling the operation of the valve means, and the control means determines the start state of the internal combustion engine and the operation state of the intake flow control valve by signals from the start determination means and the adjustment valve operation determination means And detects each actuates the intake flow control valve after starting the detection, after detecting the operation, actuates the variable valve means in a direction in which the valve overlap is extended, the elapsed time after start is set in advance predetermined After the time has elapsed, the variable valve means is operated so as to narrow the valve overlap, and then the operation of the intake flow control valve is stopped .

According to the second aspect of the present invention, the intake air is provided in the combustion passage of the internal combustion engine through the intake port so as to be freely opened and closed, and operates in the direction of narrowing the intake passage to cause in-cylinder flow in the combustion chamber. By changing the opening / closing timing of at least one of the flow control valve, the intake valve that opens and closes the intake port, and the exhaust valve that opens and closes the exhaust port, the valve overlap period in which both the intake valve and the exhaust valve are open is changed. Variable valve means, adjustment valve operation determination means for determining the operation state of the intake flow rate adjustment valve, start determination means for determining the start state of the internal combustion engine, control means for controlling the operation of the intake flow control valve and the variable valve means When the spark plug to perform ignition in the combustion chamber, having an ignition timing control means for adjusting the ignition timing by the spark plug, the control means, and a regulating valve operation determination unit start decision means The signal detects the start state of the internal combustion engine and the operating state of the intake flow control valve, and after the start is detected, the intake flow control valve is operated. After detecting the operation, the valve overlap of the variable valve means is expanded. The ignition timing control means is controlled so that the ignition timing by the spark plug is retarded after the start determination is detected , and the valve overlap is made after a predetermined time has elapsed after the start. After the variable valve means is operated so as to be narrowed, the operation of the intake flow control valve is stopped .

According to a third aspect of the present invention, there is provided an intake pressure detecting means for detecting the pressure in the intake flow path, and the adjustment valve operation determining means is detected by the intake pressure detecting means after the signal for operating the intake flow control valve is output. It is characterized in that it is determined that the intake flow rate adjusting valve has been activated when the pressure in the intake flow path is increased above a predetermined level .

According to a fourth aspect of the present invention, there is provided a rotation detecting means for detecting the number of revolutions of the internal combustion engine, and the adjustment valve operation determining means is the rotation detected by the rotation detecting means after the signal for operating the intake flow control valve is output. It is characterized in that it is determined that the intake flow rate adjusting valve is activated when the number rises above a predetermined rotational speed .

According to the fifth aspect of the present invention , the intake air that can be opened and closed in the intake passage that communicates with the combustion chamber of the internal combustion engine via the intake port and that operates in the direction of narrowing the intake passage causes the in-cylinder flow in the combustion chamber. By changing the opening / closing timing of at least one of the flow control valve, the intake valve that opens and closes the intake port, and the exhaust valve that opens and closes the exhaust port, the valve overlap period in which both the intake valve and the exhaust valve are open is changed. Variable valve means, adjustment valve operation determination means for determining the operation state of the intake flow rate adjustment valve, start determination means for determining the start state of the internal combustion engine, control means for controlling the operation of the intake flow control valve and variable valve means When provided with a rotation detecting means for detecting a rotational speed of the internal combustion engine, the control means by a signal from a start decision means regulating valve operation determination means and the starting state of the internal combustion engine intake flow control valve And detects the operating state, respectively, to actuate the intake flow control valve after starting the detection, after detecting the operation, actuates the variable valve means in a direction in which the valve overlap is extended, regulating valve operation determination means, After the signal for activating the intake flow control valve is output, it is determined that the intake flow rate adjusting valve is activated when the rotation speed detected by the rotation detecting means rises to a predetermined rotation speed or more.
According to the sixth aspect of the present invention, intake air is provided in the combustion passage of the internal combustion engine through the intake port so as to be openable and closable, and operates in the direction of narrowing the intake passage to cause in-cylinder flow in the combustion chamber. By changing the opening / closing timing of at least one of the flow control valve, the intake valve that opens and closes the intake port, and the exhaust valve that opens and closes the exhaust port, the valve overlap period in which both the intake valve and the exhaust valve are open is changed. Variable valve means, adjustment valve operation determination means for determining the operation state of the intake flow rate adjustment valve, start determination means for determining the start state of the internal combustion engine, control means for controlling the operation of the intake flow control valve and variable valve means An ignition plug for igniting the combustion chamber, ignition timing control means for adjusting the ignition timing by the ignition plug, and rotation detection means for detecting the rotational speed of the internal combustion engine. Detects the start state of the internal combustion engine and the operation state of the intake flow control valve based on signals from the start determination means and the adjustment valve operation determination means, and operates the intake flow control valve after detecting the start, and detects its operation. After that, the variable valve means is operated in the direction in which the valve overlap is expanded, and the ignition timing control means is controlled so as to retard the ignition timing by the ignition plug after the start determination is detected. After the signal for activating the flow control valve is output, it is determined that the intake flow rate adjusting valve is activated when the number of rotations detected by the rotation detecting means rises above a predetermined number of rotations.

  According to the present invention, when the control unit detects the start state of the internal combustion engine and the operation state of the intake flow control valve by signals from the start determination unit and the adjustment valve operation determination unit, the intake flow control valve After the operation is detected and the operation is detected, the variable valve means is operated in the direction of expanding the valve overlap. Therefore, the combustion is promoted by the in-cylinder flow strengthened by the intake flow control valve and the combustion temperature rises. Since the amount increases, vibration and misfire engine stall can be prevented and drivability can be reduced while maintaining drivability.

  According to the present invention, since the ignition timing control means is controlled so as to retard the ignition timing by the spark plug after the start determination is detected by the control means, the exhaust gas temperature rises, so that the temperature raising performance of the catalyst is further enhanced. Can do.

  According to the present invention, after the elapsed time after starting by the control means has passed a predetermined time, the variable valve means is operated so as to narrow the valve overlap, and then the operation of the intake flow control valve is stopped. Therefore, the amount of internal EGR changes while maintaining the state where combustion is promoted by the in-cylinder flow strengthened by the intake flow control valve, so that the stability of combustion can be maintained, and in particular, vibration and misfire engine stall can be prevented. Drivability can be maintained.

According to the present invention, after the signal for operating the intake flow control valve is output, when the pressure in the intake flow path detected by the intake pressure detection means for detecting the pressure in the intake flow path rises above a predetermined level, , when the rotational speed detected by the rotation detecting means for detecting a rotational speed of the internal combustion engine rises above Jo Tokoro rotational speed, the intake flow control valve is determined to have operated, are used in the existing internal combustion engine The detection means can reliably determine the operating state of the intake flow rate adjusting valve, and the number of parts can be reduced.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In FIG. 1, reference numeral 1 denotes an engine which is an internal combustion engine. The engine 1 is configured as an engine that injects fuel into an intake port 11 located at the tip of an intake passage 12, and a DOHC 4-valve type is adopted as a valve operating mechanism. A cylinder head 2 is mounted on an upper portion of a cylinder block 2a constituting the engine 1. The intake side valve mechanism 50 includes an intake valve 7a for opening and closing an intake port 11 formed in the cylinder head 2 so as to communicate the intake passage 12 and the combustion chamber 40, and a rocker (not shown) at the upper end of the intake valve 7a. The intake camshaft 21 is formed with an intake cam 3a that abuts via an arm, and a known valve spring that biases the intake valve 7a in the valve closing direction. The exhaust-side valve mechanism 51 includes an exhaust valve 7b that opens and closes the exhaust port 17 formed in the cylinder head 2 so as to communicate with the combustion chamber 40, and an exhaust that abuts the upper end of the exhaust valve 7b via a rocker arm (not shown). The exhaust camshaft 22 is formed with a cam 3b, and a known valve spring that biases the exhaust valve 7b in the valve closing direction.

  Timing pulleys 4a and 4b are mounted on the ends of the intake camshaft 21 and the exhaust camshaft 22, respectively. These timing pulleys 4a and 4b are connected to the crankshaft 6 via a timing belt (not shown). The timing pulleys 4 a and 4 b and the camshafts 21 and 22 are rotationally driven as the crankshaft 6 rotates, and the intake and exhaust valves 7 a and 7 b are opened and closed in synchronization with the rotation of the engine 1 by the camshafts 21 and 22. Driven.

  Between the camshaft 21 and the timing pulley 4a, a valve timing variable mechanism 8a (hereinafter referred to as "VVT8a") is provided as variable valve means for displacing the phase of the opening / closing timing of the intake valve 7a. The configuration of the VVT 8a is a so-called vane type variable valve timing mechanism, and an advance side hydraulic chamber and a retard side hydraulic pressure (not shown) that variably adjust the phase between the camshaft 21 provided with the intake cam 3a and the timing pulley 4a. By switching the hydraulic oil supplied from the oil pump 10 of the engine 1 to the chamber by an oil control valve (hereinafter referred to as “OCV”) 9 a serving as an operation control member, the phase with respect to the crank angle of the camshaft 21 is changed. It is a known configuration that controls to adjust the opening and closing timing of the intake valve 7a.

  In the vehicle interior, an input / output device (not shown), a storage device (ROM, RAM, etc.) used for storing control programs, control maps, etc., a central processing unit (CPU), an ECU as a control means provided with a timer counter, etc. An engine control unit (hereinafter referred to as “ECU”) 31 is installed and performs overall control of the engine 1.

  The cylinder head 2 has an electromagnetic fuel injection valve 15 as fuel injection means for injecting fuel into the intake port 11, and an ignition plug 19 as ignition means for facing the combustion chamber 40 and igniting the combustion chamber 40. Is provided. The spark plug 19 is connected to the ECU 31 via an ignition timing control means 27 that adjusts the ignition timing. The ignition plug 19 is controlled by the ECU 31 and ignites when an ignition signal output from the ignition timing control means 27 is applied.

  A throttle valve 14 in the intake passage 12 and an intake flow control valve (hereinafter referred to as “FCV”) that generates a tumble flow that is a form of in-cylinder flow in the combustion chamber 40 by operating in a direction to narrow the intake passage 12. ) 37). The throttle valve 14 is connected to an accelerator pedal 34 via a wire (not shown) or an electronic control mechanism, and its opening degree is adjusted according to the depression amount of the accelerator pedal 34. The FCV 37 is supported in an intake passage 12 positioned between the fuel injection valve 15 and the throttle valve 14 so as to be freely opened and closed by a flange (not shown). The FCV 37 is connected to an electromagnetic actuator 38 as a driving means, and normally occupies a standby position where it does not enter the intake flow path 14 as shown in FIG. 1, and when the electromagnetic actuator 38 is driven, it operates in a direction of narrowing the flow path. As shown in FIG. 2, it occupies an entry position for entering the intake flow path 12.

  In this embodiment, when the FCV 37 occupies the intrusion position shown in FIG. 2, a tumble flow that rotates vertically in the counterclockwise direction in FIG. It is configured as follows. The electromagnetic actuator 38 is provided with an adjustment valve opening sensor 39 that detects the opening of the FCV 37 as an adjustment valve operation determining means for determining the operation state of the FCV 37.

  As the engine 1 is started, intake air is introduced from the air cleaner 13 as the piston 16 reciprocates up and down in FIG. After the flow rate is adjusted according to the opening degree of the valve 14, it is mixed with the fuel injected from the fuel injection valve 15, and flows into the cylinder 2b via the intake port 11 when the intake valve 7a is opened. The fuel injection valve 15 is set with a fuel injection amount corresponding to the operating state of the engine 1 and applies a fuel injection signal from the ECU 31 to execute fuel injection at an optimal timing for combustion. Further, the ignition plug 19 is ignited at an optimum timing by setting an ignition timing corresponding to the operating state of the engine 1 and applying an ignition signal from the ignition timing ignition timing control means 27.

  In the exhaust passage 18 connected to the exhaust port 17, exhaust gas after combustion in the combustion chamber 40 is discharged from the exhaust port 17 as the piston 16 rises when the exhaust valve 7b is opened, and the exhaust passage 18 The catalyst is discharged to the outside through a three-way catalyst 20 as a catalyst provided above and a silencer (not shown).

  As shown in FIG. 3, on the input side of the ECU 31, a cam angle sensor 28 for detecting the rotation angle of the camshaft 21, a crank angle sensor 32 as crank angle detecting means for detecting the crank angle of the crankshaft 6, an engine load A throttle opening sensor 33 as load detecting means for detecting the opening of the throttle valve 14, a water temperature sensor 36 for detecting the water temperature of the engine 1, an adjustment valve opening sensor 39, and a timer (not shown) are connected. The OCV 9a, the fuel injection valve 15, the ignition timing control means 27, and the electromagnetic actuator 38 are connected to the output side of the ECU 31, and the ECU 31 functions as a control means for controlling the operation of the intake flow control valve 27 and the OCV 9a.

  In this embodiment, it is assumed that the crankshaft 6 rotates twice for a series of four strokes of an intake stroke, a compression stroke, an expansion stroke, and an exhaust stroke in the engine 1, and the crank angle sensor 32 has a rate of 30 ° CA per pulse. The crank angle is detected. The ECU 31 calculates the engine speed Ne from the pulse from the crank angle sensor 32, determines the fuel injection amount and the ignition timing based on the detection information from each sensor, the fuel injection valve 15 and the ignition timing ignition timing control means. 27 is driven and controlled. That is, the ECU 31 determines the fuel injection amount from the fuel injection valve 15 and the ignition timing for the spark plug 19 based on the crank angle signal from the crank angle sensor 32 and the load information from the throttle opening sensor 33. A map (not shown) is set in a ROM (not shown), and the fuel injection amount and ignition timing are appropriately controlled based on the map information.

  In the ROM of the ECU 31, angle information θ1 and θ2 when the FCV 37 occupies the intrusion position and the standby position, water temperature information WT1 for determining the state of the engine 1 such as cold state and warm state, idle rotation Rotation information Ne1 indicating that the rotation range is low, and predetermined elapsed time information T1 after cold start is preset.

  In the present embodiment, when the cold start of the engine 1 is determined based on the water temperature information detected from the water temperature sensor 36 and the rotation information detected from the crank angle sensor 32, the ECU 31 performs the electromagnetic actuator 38 after the cold start determination. , The FCV 37 is actuated, and after the actuation is detected, the OCV 9a of the VVT 8a is actuated in the direction in which the valve overlap expands, and the elapsed time after the start is measured with a timer, and the measured value T is preset. After the predetermined time T1 has elapsed, the OCV 9a is operated so as to narrow the valve overlap (VOL), and thereafter, the electromagnetic actuator 38 is stopped and the intake flow control valve 27 is stopped.

  An example of the processing operation by the control device having such a configuration will be described with reference to the flowchart shown in FIG. The flowchart in FIG. 4 is executed by the ECU 31 when the engine is started. In step S1 of FIG. 4, information from various sensors is captured. This includes FCV 37 opening information θ, water temperature information WT1, and rotation information Ne1 output from the adjustment valve opening sensor 39.

  In step S2, the temperature information T from the water temperature sensor 36 is compared with the water temperature information WT1, and it is determined whether or not the engine is in cold start. If the temperature information T is less than the water temperature information WT1, the cooling is performed. The process proceeds to step S3 as a start, and when the temperature information T has reached the water temperature information WT1, this control is finished.

  In step S3, the engine speed Ne is compared with the rotation information Ne1, and it is determined whether or not the engine 1 is in the low speed region. If the engine speed Ne is less than the rotation information Ne1, the process proceeds to step S4, assuming that the engine speed Ne is at the rotation information Ne1, and if the engine speed Ne has reached the rotation information Ne1, this control is performed. Finish.

  When a signal for operating the FCV 37 is output in step S4, the process proceeds to step S5. In step S5, the opening information θ of the FCV 37 and the angle information θ1 are compared to determine whether the FCV 37 has occupied the intrusion position (whether the FCV 37 has been fully closed). Here, when the opening degree information θ from the adjustment valve opening degree sensor 39 is the angle information θ1, the process proceeds to step S6, the VOL expansion flag is turned on and the process proceeds to step S8, and the opening degree information θ is not the angle information θ1. In step S7, the VOL expansion flag is turned off, and the flow advances to step S8.

  In step S8, it is determined whether or not the VOL expansion flag is turned on. If the VOL expansion flag is turned on, the process proceeds to step S9 to perform a valve overlap (VOL) expansion operation, and the VOL expansion flag is not turned on. In this case, the process proceeds to step S10 to cancel the valve overlap (VOL) expansion operation. That is, in step S9, the OCV 9a operates in a direction to increase the valve overlap (VOL), and in step S10, the OCV 9a operates in a direction to return the expanded valve overlap (VOL).

  In step S11, the measurement time T measured by the timer measured from the start of the cold start is compared with the predetermined elapsed time information T1. Then, the process returns to step S8 until the measured time T reaches the predetermined elapsed time information T1, and when the measured time T reaches the predetermined elapsed time information T1, the cold start is canceled and the process proceeds to step S12.

  In step S12, the OCV 9a is operated in a direction to return the expanded valve overlap (VOL) to the base, and the process proceeds to step S13. In step S13, the drive of the electromagnetic actuator 38 is stopped, the operation of the FCV 37 is stopped, and the operation is returned to the standby position to finish this control.

  As described above, according to the configuration of the present embodiment, when the engine 1 is cold-started and in the low rotation range, the electromagnetic actuator 38 of the FCV 37 is driven to move the FCV 37 toward the intrusion position shown in FIG. When the position (fully closed position) is occupied, the VVT 8a is operated in the direction in which the valve overlap expands. Therefore, the valve overlap expands after the combustion in the combustion chamber 40 is stabilized by the tumble flow enhanced by the FCV 37. Since the amount of internal EGR increases, vibration and misfire engine stall can be prevented, and exhaust gas can be reduced while maintaining drivability.

  Further, after the elapsed time T after the start has passed a predetermined time T1, the VVT 8a is operated so as to narrow the valve overlap, the drive of the electromagnetic actuator 38 is stopped, and the operation of the FCV 37 is stopped. Since it returns to the standby position, the internal EGR amount is reduced in a state where combustion in the combustion chamber 40 is promoted by the tumble flow generated by the FCV 37, so that the stability of combustion can be maintained, and particularly vibration and misfire engine stalls are caused. It can be prevented and drivability can be maintained.

  FIG. 5 shows a second embodiment. In this embodiment, control for retarding the ignition timing by the spark plug 19 after the start determination is detected is added to the function of the ECU 31 used in the first embodiment. Hereinafter, the control unit of the second embodiment will be described as the ECU 310.

  In the ROM (not shown) of the ECU 310, angle information θ1 and θ2 when the FCV 37 occupies the intrusion position and the standby position, water temperature information WT1 for determining the status of the engine 1 such as cold and hot, The rotation information Ne1 indicating the low rotation range including the idle rotation and the predetermined elapsed time information T1 after the cold start are preset.

  In this embodiment, when the cold start of the engine 1 is determined based on the water temperature information detected from the water temperature sensor 36 and the rotation information detected from the crank angle sensor 32, the ECU 310 performs the electromagnetic actuator 38 after the cold start determination. Is operated to operate the FCV 37, and after detecting the operation, the OCV 9a of the VVT 8a is operated in the direction in which the valve overlap is expanded, the ignition timing by the spark plug 19 is retarded, and the elapsed time after starting is set by a timer. After the measurement time T has passed a predetermined time T1, the OCV 9a is actuated so as to narrow the valve overlap (VOL), and then the electromagnetic actuator 38 is stopped to stop the intake flow control valve 27. Control to stop operation.

  An example of the processing operation by the control device having such a configuration will be described with reference to the flowchart shown in FIG. The flowchart in FIG. 6 is executed by the ECU 310 shown in FIG. 5 when the engine is started. In step V1 in FIG. 6, information from various sensors is captured. This includes FCV 37 opening information θ, water temperature information WT1, and rotation information Ne1 output from the adjustment valve opening sensor 39.

  In step V2, the temperature information T from the water temperature sensor 36 is compared with the water temperature information WT1, and it is determined whether or not the engine is cold start. If the temperature information T is less than the water temperature information WT1, the cooling information As a start, the process proceeds to step V3. When the temperature information T reaches the water temperature information WT1, this control is finished.

  In step V3, the engine speed Ne is compared with the rotation information Ne1, and it is determined whether or not the engine 1 is in the low speed region. If the engine speed Ne is less than the rotation information Ne1, the process proceeds to step V4 assuming that the engine speed Ne is in the low rotation area. If the engine speed Ne has reached the rotation information Ne1, the control is performed as not being in the low rotation area. Finish.

  In Step V4, when a signal for operating the FCV 37 is output, the process proceeds to Step V5. In step V5, the opening information θ of the FCV 37 and the angle information θ1 are compared to determine whether the FCV 37 has occupied the intrusion position (whether the FCV 37 is fully closed). Here, when the opening degree information θ from the adjusting valve opening degree sensor 39 is the angle information θ1, the process proceeds to step V6, the catalyst temperature increase flag is turned on and the process proceeds to step V7, and the opening degree information θ is not the angle information θ1. In this case, the process proceeds to step V7, the catalyst temperature raising flag is turned off, and the process proceeds to step V8.

  In step V8, it is determined whether or not the catalyst temperature raising flag is turned on. If it is turned on, the process proceeds to step V9 to perform a valve overlap (VOL) expansion operation, and in step V10, the ignition timing is set. The ignition timing control means 27 is controlled so as to retard. If the catalyst temperature raising flag is not turned on, the process proceeds to step V11 to cancel the valve overlap (VOL) expansion operation. That is, in step V9, the OCV 9a operates in a direction to increase the valve overlap (VOL), and in step V11, the OCV 9a operates in a direction to return the expanded valve overlap (VOL).

  In Step V12, the measurement time T measured by the timer measured from the start of the cold start is compared with the predetermined elapsed time information T1. Then, the process returns to step V8 until the measurement time T reaches the predetermined elapsed time information T1, and when the measurement time T reaches the predetermined elapsed time information T1, the cold start is canceled and the process proceeds to step V13.

  In Step V13, the OCV 9a is operated in a direction to restore the enlarged valve overlap (VOL), and the process proceeds to Step S14. In step S14, the driving of the electromagnetic actuator 38 is stopped, the operation of the FCV 37 is stopped, and the operation is returned to the standby position to finish this control.

  As described above, according to the configuration of the present embodiment, when the engine 1 is cold-started and in the low rotation range, the electromagnetic actuator 38 of the FCV 37 is driven to move the FCV 37 toward the intrusion position shown in FIG. When the position (fully closed position) is occupied, the VVT 8a is operated in the direction in which the valve overlap expands. Therefore, after the combustion in the combustion chamber 40 is promoted by the tumble flow generated by the FCV 37 and the combustion is stabilized. Since the valve overlap is expanded and the amount of internal EGR is increased, vibration and misfire engine stall can be prevented, and exhaust gas can be reduced while maintaining drivability.

  Further, since the ignition timing control means 27 is controlled so as to retard the ignition timing by the spark plug 19 after confirming the operation of the FCV 37, the exhaust gas temperature rises, and the temperature rise performance of the three-way catalyst 20 is the first embodiment. Than can be raised.

  In the first and second embodiments, the operation of the FCV 37 is directly detected using the adjustment valve opening sensor 39 that detects the opening θ of the FCV 37 as the adjustment valve operation determination means. However, it is not limited to such a form. For example, a switch that operates when the FCV 37 occupies the intrusion position may be provided, and this switch may be used as the adjustment valve operation determination means.

  When the FCV 37 occupies the intrusion position, the flow path is narrowed and the pressure in the intake flow path 12 becomes high. Therefore, as shown in FIG. 1, the pressure sensor 60 serves as an intake pressure detection means for detecting the pressure in the intake flow path 12. The output AP is taken in by the ECUs 31 and 310 from the sensor 60, and the average pressure AP1 in the intake passage 12 when the FCV 37 occupies the intrusion position is stored in the ROM in advance and detected by the pressure sensor 60. If the pressure AP in the intake passage 12 is greater than the predetermined pressure AP1, it may be determined that the FCV 37 has been activated. That is, steps S5 and V5 in FIGS. 4 and 6 may be performed in this manner.

  When the FCV 37 occupies the intrusion position, the flow path is narrowed and the tumble flow is strengthened and combustion is promoted. Therefore, the engine speed Ne increases, so the engine speed Ne2 when the FCV 37 occupies the intrusion position is calculated. It is stored in advance in the ROM, and the engine speed Ne is detected using the crank angle sensor 32 as the rotation detecting means. When the detected speed Ne is higher than the predetermined speed Ne2, the FCV 37 is activated. You may judge. That is, steps S5 and V5 in FIGS. 4 and 6 may be performed in this manner.

  By estimating that the FCV 37 has indirectly occupied the intrusion position from parameters that correlate with the operation status of the FCV 37, existing sensors can be used, and costs can be reduced.

It is a figure which shows schematic structure of the internal combustion engine concerning the 1st Embodiment of this invention, and its control means. It is an enlarged view which shows the non-operation state and operation state of an intake air flow control valve. It is a block diagram which shows the structure of a control means. It is a flowchart of control concerning a 1st embodiment. It is a block diagram of the control means concerning the 2nd one embodiment of the present invention. It is a flowchart of control concerning a 2nd embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Internal combustion engine 7a Intake valve 7b Exhaust valve 8a Variable valve means 11 Intake port 12 Intake flow path 17 Exhaust port 19 Spark plug 27 Ignition timing control means 31, 310 Control means 32 Rotation detection means 36 Start determination means 37 Intake flow control valve 39 Adjusting valve operation determining means 40 Combustion chamber 60 Intake pressure detecting means P1 Predetermined pressure T Elapsed time T1 Predetermined time Ne2 Predetermined speed

Claims (6)

An intake flow control valve that is provided in an intake passage that communicates with the combustion chamber of the internal combustion engine via an intake port so as to be openable and closable, and that generates an in-cylinder flow in the combustion chamber by operating in a direction to narrow the intake passage;
Variable valve means for changing a valve overlap period in which both the intake valve and the exhaust valve are open by changing the opening / closing timing of at least one of the intake valve for opening / closing the intake port and the exhaust valve for opening / closing the exhaust port When,
Adjusting valve operation determining means for determining an operating state of the intake flow rate adjusting valve;
Start determination means for determining a start state of the internal combustion engine;
Control means for controlling the operation of the intake flow control valve and the variable valve means,
The control means detects a start state of the internal combustion engine and an operation state of the intake flow control valve based on signals from the start determination means and the adjustment valve operation determination means, and after the start is detected, the intake flow control valve After detecting the operation, the variable valve means is operated in a direction in which the valve overlap expands , and the valve overlap is narrowed after an elapse time after starting a predetermined time. Thus, after the variable valve means is operated, the operation of the intake flow control valve is stopped . An intake flow control valve that is provided in an intake passage that communicates with the combustion chamber of the internal combustion engine via an intake port so as to be openable and closable, and that generates an in-cylinder flow in the combustion chamber by operating in a direction to narrow the intake passage;
Variable valve means for changing a valve overlap period in which both the intake valve and the exhaust valve are open by changing the opening / closing timing of at least one of the intake valve for opening / closing the intake port and the exhaust valve for opening / closing the exhaust port When,
Adjusting valve operation determining means for determining an operating state of the intake flow rate adjusting valve;
Start determination means for determining a start state of the internal combustion engine;
Control means for controlling the operation of the intake flow control valve and the variable valve means;
An ignition plug for igniting in the combustion chamber, and an ignition timing control means for adjusting an ignition timing by the ignition plug;
The control means detects a start state of the internal combustion engine and an operation state of the intake flow control valve based on signals from the start determination means and the adjustment valve operation determination means, and after the start is detected, the intake flow control valve After the operation is detected, the variable valve means is operated in a direction in which the valve overlap is expanded, and the ignition timing control means is set so as to retard the ignition timing by the spark plug after the start determination is detected. And , after the elapsed time after starting a predetermined time after starting, the variable valve means is operated so as to narrow the valve overlap, and then the operation of the intake flow control valve is stopped. A control device for an internal combustion engine. The control device for an internal combustion engine according to claim 1 or 2,
Intake pressure detection means for detecting the pressure in the intake flow path,
The adjustment valve operation determination means adjusts the intake flow rate when the pressure in the intake flow path detected by the intake pressure detection means rises above a predetermined level after a signal for operating the intake flow control valve is output. A control device for an internal combustion engine, characterized in that it is determined that a valve is operated . The control device for an internal combustion engine according to claim 1, 2, or 3,
A rotation detecting means for detecting the rotation speed of the internal combustion engine;
The adjustment valve operation determining means operates when the rotation speed detected by the rotation detection means rises above a predetermined rotation speed after a signal for operating the intake flow control valve is output. A control apparatus for an internal combustion engine, characterized in that it is determined that An intake flow control valve that is provided in an intake passage that communicates with the combustion chamber of the internal combustion engine via an intake port so as to be openable and closable, and that generates an in-cylinder flow in the combustion chamber by operating in a direction to narrow the intake passage;
Variable valve means for changing a valve overlap period in which both the intake valve and the exhaust valve are open by changing the opening / closing timing of at least one of the intake valve for opening / closing the intake port and the exhaust valve for opening / closing the exhaust port When,
Adjusting valve operation determining means for determining an operating state of the intake flow rate adjusting valve;
Start determination means for determining a start state of the internal combustion engine;
Control means for controlling the operation of the intake flow control valve and the variable valve means;
A rotation detecting means for detecting the rotation speed of the internal combustion engine;
The control means detects a start state of the internal combustion engine and an operation state of the intake flow control valve based on signals from the start determination means and the adjustment valve operation determination means, and after the start is detected, the intake flow control valve After detecting the operation, the variable valve means is operated in the direction in which the valve overlap is expanded,
The adjustment valve operation determining means operates when the rotation speed detected by the rotation detection means rises above a predetermined rotation speed after a signal for operating the intake flow control valve is output. A control apparatus for an internal combustion engine, characterized in that it is determined that An intake flow control valve that is provided in an intake passage that communicates with the combustion chamber of the internal combustion engine via an intake port so as to be openable and closable, and that generates an in-cylinder flow in the combustion chamber by operating in a direction to narrow the intake passage;
Variable valve means for changing a valve overlap period in which both the intake valve and the exhaust valve are open by changing the opening / closing timing of at least one of the intake valve for opening / closing the intake port and the exhaust valve for opening / closing the exhaust port When,
Adjusting valve operation determining means for determining an operating state of the intake flow rate adjusting valve;
Start determination means for determining a start state of the internal combustion engine;
Control means for controlling the operation of the intake flow control valve and the variable valve means;
An ignition plug that performs ignition in the combustion chamber; ignition timing control means that adjusts an ignition timing by the ignition plug;
A rotation detecting means for detecting the rotation speed of the internal combustion engine;
The control means detects a start state of the internal combustion engine and an operation state of the intake flow control valve based on signals from the start determination means and the adjustment valve operation determination means, and after the start is detected, the intake flow control valve After the operation is detected, the variable valve means is operated in a direction in which the valve overlap is expanded, and the ignition timing control means is set so as to retard the ignition timing by the spark plug after the start determination is detected. Control
The adjustment valve operation determining means operates when the rotation speed detected by the rotation detection means rises above a predetermined rotation speed after a signal for operating the intake flow control valve is output. A control apparatus for an internal combustion engine, characterized in that it is determined that

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