JP3946361B2 - Control device for electromagnetically driven valve for internal combustion engine - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a control device for an electromagnetically driven valve for an internal combustion engine, and more particularly to a control technique for an intake / exhaust valve during cranking.
[0002]
[Prior art]
Conventionally, an electromagnetically driven valve having a configuration in which an intake / exhaust valve elastically supported by a spring at a neutral position is displaced between a fully closed position and a fully open position by electromagnetic force is known. The starting method is employed in which the intake and exhaust valves are sequentially displaced from the neutral position to the fully closed position by a method of exciting the natural vibration of the spring mass system after cranking is started.
[0003]
[Problems to be solved by the invention]
However, as described above, the starting method to be displaced successively fully closed position the intake and exhaust valves during cranking, that cranking rotation speed, the compression work occurs before reaching a predetermined speed obtained sustained rotation Therefore, the rise of the cranking rotation speed becomes dull, resulting in a problem that the time required for starting becomes longer and the power consumption of the starter motor increases.
[0004]
The present invention has been made in view of the above problems, the cranking rotation speed, to provide a control apparatus for an internal combustion engine for an electromagnetically driven valve that can reduce the compression work to reach a rotational speed sustained rotation is obtained Accordingly, it is an object to increase the cranking rotation speed with good response to shorten the starting time and reduce the power consumption of the starter motor.
[0005]
[Means for Solving the Problems]
Therefore, the invention according to claim 1 is for an internal combustion engine configured to elastically support the intake / exhaust valve in a neutral position by an elastic body and to displace the intake / exhaust valve to a fully open position or a fully closed position by electromagnetic force. a control apparatus for an electromagnetically driven valve, is displaced to the fully open position from the neutral position at least one of the intake valves at the beginning of startup and the exhaust valve, is held in the fully open position until it reaches a predetermined cranking rotation speed, the The intake / exhaust valve is displaced to the fully closed position at the end of the intake stroke in each cylinder after reaching a predetermined cranking rotational speed .
[0006]
According to such a configuration, the intake and exhaust valves that have been held in the fully opened position in order from the cylinder that first enters the intake stroke after reaching the predetermined cranking rotation speed are all set at the crank angle position that ends the intake stroke. The closed position is controlled so that the intake and exhaust valves are both closed in the compression stroke following the intake stroke.
[0007]
According to a second aspect of the present invention, the intake / exhaust valve is elastically supported by the elastic body in the neutral position, and the intake / exhaust valve is displaced to the fully open position or the fully closed position by electromagnetic force. A control device for a drive valve, wherein at the start of starting, at least one of an intake valve and an exhaust valve is displaced from a neutral position to a fully open position and held at a fully open position until a predetermined cranking rotational speed is reached. The exhaust valve is displaced to the fully closed position at the start timing of the intake stroke in each cylinder after the cranking rotation speed is reached, and the intake valve is displaced to the fully closed position at the end timing of the intake stroke.
[0008]
According to such a configuration, the exhaust valve is controlled to the fully closed position at the start timing of the intake stroke in order from the cylinder that becomes the intake stroke first after reaching the predetermined cranking rotation speed, and at the end timing of the intake stroke. Is fully closed.
[0009]
The invention according to claim 3 is configured such that the displacement from the neutral position to the fully open position is performed when the ignition switch is turned on. According to this configuration, when the ignition switch is turned on, that is, before the starter motor is turned on, the intake / exhaust valve is controlled to be displaced from the neutral position to the fully opened position.
[0010]
The invention according to claim 4 is configured such that the displacement from the neutral position to the fully open position is performed by exciting the natural vibration of the elastic mass system by the electromagnetic force. According to such a configuration, the electromagnetic force in the valve opening direction and the electromagnetic force in the valve closing direction are alternately generated so that the vibration matching the natural frequency of the elastic body mass system of the electromagnetically driven valve is generated by the electromagnetic force. The amplitude of the exhaust valve is gradually increased, and finally suctioned and held at the fully open position.
[0011]
According to a fifth aspect of the present invention, the control for displacing to the fully closed position is configured to start from a time point before the required fully closed timing by a time required for displacement to the fully closed position. According to such a configuration, there is a delay time from the start of the control for displacing to the fully closed position until the intake and exhaust valves are actually fully closed. Control for displacing to the closed position is started, and the displacement to the fully closed position is terminated when the requested timing is reached .
[0012]
【The invention's effect】
According to the first and second aspects of the present invention, the compression work until the cranking rotation speed reaches the rotation speed at which the continuous rotation can be obtained can be positively reduced. The start-up time can be shortened by shortening the start-up time and the power consumption of the starter motor can be reduced, and the cranking rotation speed is unnecessary even after reaching the rotation speed at which continuous rotation is obtained. There is an effect that it is possible to ignite and burn sequentially from the combustible cylinder while avoiding the generation of compression work.
[0013]
According to the third aspect of the invention, by causing displacement in the fully open position during ON of the ignition switch, there is an effect that can be easily be held in the fully open position the intake and exhaust valves from the cranking start.
[0014]
According to the fourth aspect of the invention, there is an effect that the displacement from the neutral position of the intake / exhaust valve to the fully open position can be performed with a small amount of electric power.
[0015]
According to the fifth aspect of the present invention, when the intake and exhaust valves are sequentially displaced to the fully closed position after reaching the cranking rotation speed, the intake and exhaust valves can be displaced to the fully closed position without delaying the required fully closed timing. There is an effect that can be done.
[0016]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a diagram showing a system configuration of an internal combustion engine. A throttle valve 3 is provided in an intake passage 2 of a four-cycle internal combustion engine 1, and an auxiliary air passage 4 that bypasses the throttle valve 3 is provided. The auxiliary air passage 4 is provided with an electromagnetic auxiliary air control valve 5.
[0017]
The internal combustion engine 1 controls the opening / closing timing of the intake valve 12 by, for example, an electromagnetic valve device (electromagnetically driven valve) 13, which will be described later, and takes in the intake air at atmospheric pressure while reducing the intake air amount without a throttle valve. In the case of an engine that can be controlled (for example, a Miller cycle engine), the throttle valve 3, the auxiliary air passage 4, and the auxiliary air control valve 5 can be omitted.
[0018]
Further, an electromagnetic fuel injection valve 6 is provided for each cylinder in the intake port portion of the intake passage 2, and fuel (gasoline) is supplied to the engine by the fuel injection valve 6. Signals are input from various sensors to the control unit 7 incorporating the microcomputer. Specifically, a crank angle sensor 8 that outputs a reference angle signal Ref for each reference piston position and a unit angle signal Pos for each unit crank angle is provided, whereby the piston position can be detected, and the engine The rotational speed Ne can be calculated. The crank angle sensor 8 is a sensor for detecting a detected portion formed on a signal plate that rotates twice per rotation of the engine (crankshaft), and the reference angle signal Ref has, for example, a pulse width that is different for each cylinder. The cylinder is discriminated by outputting the above signal. However, the configuration for cylinder discrimination is not limited to the above.
[0019]
Further, an air flow meter 9 for detecting the intake air flow rate Qa of the engine, a throttle sensor 10 for detecting the opening degree TVO of the throttle valve 3, a water temperature sensor 11 for detecting the cooling water temperature Tw of the engine 1, and the like are provided. The control unit 7 controls the fuel injection by the fuel injection valve 6 based on the engine operating conditions detected by the various sensors, and controls the ignition timing by the spark plug 17 and the electromagnetic valve devices 13 and 15 to be described later. Control.
[0020]
Further, the engine 1 is provided with an electromagnetic valve device 13 that drives the intake valve 12 to open and close, and an electromagnetic valve device 15 that drives the exhaust valve 14 to open and close. The configuration of the electromagnetic valve devices (electromagnetically driven valves) 13 and 15 is shown in FIG. In FIG. 2, the electromagnetic valve devices 13, 15 are provided integrally with a non-magnetic material housing 21 provided on the cylinder head and a stem 31 of the intake / exhaust valves 12, 14 so as to freely move within the housing 21. The armature 22 to be stored and the armature 22 are fixedly disposed in the housing 21 at a position facing the upper surface of the armature 22 so as to exert an electromagnetic force for sucking the armature 22 and closing the intake / exhaust valves 12 and 14. The valve closing electromagnet 23 and an opening that is fixedly disposed in the housing 21 at a position facing the lower surface of the armature 22 so as to exert an electromagnetic force that attracts the armature 22 and opens the intake / exhaust valves 12 and 14. Electromagnet 24 for valve, valve closing side return spring 25 (elastic body) for urging the armature 22 toward the valve closing direction of the intake / exhaust valves 12, 14, and toward the valve opening direction of the intake / exhaust valves 12, 14 Opening side return spring 26 (elastic body) that urges the armature 22 Configured to include a. When both the valve closing electromagnet 23 and the valve opening electromagnet 24 are turned off, the intake / exhaust valves 12 and 14 are elastically supported at a neutral position between the fully opened position and the fully closed position. Thus, the spring force of the valve closing side return spring 25 and the valve opening side return spring 26 is set.
[0021]
In the above configuration, for example, when fully closed, the energization to the valve opening electromagnet 24 is stopped, the valve closing electromagnet 23 is energized to generate electromagnetic force, and the armature 22 is attracted to the valve closing electromagnet 23. When opening the valve from the fully closed position, the energization to the valve closing electromagnet 23 is stopped, the valve element is moved in the valve opening direction by the reaction force of the valve opening side return spring 26, and this movement is performed. The coming valve element is energized to the valve opening electromagnet 24 to generate electromagnetic force, and the armature 22 is attracted to the valve opening electromagnet 24 and held in the fully opened position.
[0022]
Furthermore, when closing the valve from the state held in this fully open position, the energization to the electromagnet 24 for valve opening is stopped, and the valve body is moved in the valve closing direction by the reaction force of the valve closing side return spring 25, The moving valve body is energized to the valve closing electromagnet 23 to generate an electromagnetic force, and the armature 22 is attracted to the valve closing electromagnet 23 and held in the fully closed position. By repeating such an operation periodically, a function as a valve gear for an internal combustion engine is exhibited.
[0023]
Here, the control of the electromagnetic valve devices (electromagnetically driven valves) 13 and 15 at the start of the engine 1 will be described according to the flowchart of FIG. 3 with reference to the time chart of FIG. In the flowchart of FIG. 3, in S1, it is determined whether the ignition switch is ON or OFF, and when the ignition switch is turned ON, the process proceeds to S2.
[0024]
In S2, initialization control for displacing all of the intake / exhaust valves 12, 14 from the neutral position to the fully open position is performed, and the fully open position is held until the fully closed control described later is performed. The initialization control is performed by alternately energizing the valve closing electromagnet 23 and the valve opening electromagnet 24 at a cycle according to the natural frequency of the spring mass system of the electromagnetic valve devices 13 and 15. It is preferable to use a method of gradually increasing the amplitude of the body and finally attracting it to the fully open position. If the configuration utilizes the resonance phenomenon as described above, the power required for initialization can be reduced.
[0025]
However, a configuration may be adopted in which only the valve opening electromagnet 24 is energized and displaced from the neutral position to the fully open position at once. When the displacement to the fully open position is completed, it is determined whether or not the starter motor is driven in S3. When the starter motor is driven and cranking is started, the process proceeds to S4 and cylinder determination using the crank angle sensor 8 is performed. I do.
[0026]
In the next S5, it is determined whether or not the engine rotational speed is equal to or higher than a reference rotational speed (predetermined cranking rotational speed) stored in advance. The reference rotational speed is the minimum rotational speed at which the engine 1 can be continuously rotated by the occurrence of the first explosion, and the intake and exhaust valves 12 and 14 are kept fully open until the reference rotational speed is reached. Wait.
[0027]
If it is determined in S5 that the engine rotational speed is equal to or higher than the reference rotational speed, the process proceeds to S6, and the cylinder that reaches the next intake stroke (fuel injection timing) is determined. Then, the process proceeds from S1 to S7 in order from the first cylinder in the intake stroke, and the intake and exhaust valves 12 and 14 that have been held in the fully open position are controlled so as to be in the fully closed position at the crank angle position where the intake stroke is completed. In the compression stroke following the intake stroke, the intake and exhaust valves 12 and 14 are both closed. It is assumed that the fuel injection is started sequentially from the cylinder determined to have the next intake stroke in S6.
[0028]
The displacement to the fully closed position stops the energization of the valve opening electromagnet 24, moves the valve body in the valve closing direction by the reaction force of the valve closing side return spring 25, and closes the moving valve body. It is done by energizing the valve electromagnet 23 to generate electromagnetic force and attracting the armature 22 to the valve close electromagnet 23, but in order to displace from the fully open position to the fully closed position, a response delay occurs, Control for displacing to the fully closed position is started from a time point before the response delay time before the crank angle position at which the intake stroke is completed.
[0029]
For cylinders in which the intake / exhaust valves 12 and 14 are displaced to the fully closed position as described above, the process proceeds to S8, and thereafter, the normal open / close switching control according to the intake / compression / expansion / exhaust stroke is shifted. To. In S9, it is determined whether or not the transition to the normal control has been completed for all the cylinders. If the transition to the normal control has not been completed for all the cylinders, the process returns to S6 to enter the next intake stroke. Is determined, and the intake and exhaust valves 12 and 14 held in the fully open position are displaced to the fully closed position.
[0030]
As described above, if the intake and exhaust valves 12 and 14 are held in the fully open position until the reference rotational speed is reached, the compression work is reduced, the rise of the cranking rotational speed is accelerated, and the starting time is shortened. As a result, the power consumption of the starter motor is reduced. Further, even when the reference rotational speed is reached, all cylinders are not displaced to the fully closed position all at once, but are sequentially displaced to the fully closed position for each cylinder, so that unnecessary compression work can be avoided.
[0031]
In the above description, the intake and exhaust valves 12 and 14 are simultaneously displaced to the fully closed position at the end timing of the intake stroke from the cylinder that reaches the intake stroke after reaching the reference rotation speed. Thus, the exhaust valve 14 can be controlled to the fully closed position, and the intake valve 12 can be controlled to be fully closed at the end of the intake stroke . The timing at which the intake / exhaust valves 12, 14 are displaced from the neutral position to the fully open position may be when the starter motor is ON.
[0032]
Furthermore, when the ignition switch is turned on or the starter motor is turned on, cranking is started with only the intake valve 12 being moved from the neutral position to the fully open position, and then the exhaust valve 14 is displaced from the neutral position to the fully opened position. Also good. Also, with only the intake valve 12 in the fully open position, the exhaust valve is held in the neutral position, and after reaching the reference rotational speed, the intake valve 12 is displaced from the fully open position to the fully closed position. The displacement from the neutral position to the fully closed position may be performed. With this configuration, power consumption for driving to the fully open position can be distributed or reduced, and battery consumption can be suppressed.
[Brief description of the drawings]
FIG. 1 is a system configuration diagram of an engine in an embodiment.
FIG. 2 is a longitudinal sectional view showing details of an electromagnetic valve device in an embodiment.
FIG. 3 is a flowchart showing intake / exhaust valve control at start-up in the embodiment.
FIG. 4 is a time chart showing the characteristics of intake / exhaust valve control at the start in the embodiment.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Internal combustion engine 7 ... Control unit 8 ... Crank angle sensor
12… Intake valve
13 ... Electromagnetic valve device (for intake valve)
14 ... Exhaust valve
15 ... Electromagnetic valve device (for exhaust valve)

Claims (5)

A control device for an electromagnetically driven valve for an internal combustion engine configured to elastically support an intake / exhaust valve at a neutral position by an elastic body and to displace the intake / exhaust valve to a fully open position or a fully closed position by electromagnetic force. ,
At the start of starting, at least one of the intake valve and the exhaust valve is displaced from the neutral position to the fully open position, and held at the fully open position until reaching a predetermined cranking rotational speed,
A control device for an electromagnetically driven valve for an internal combustion engine , wherein the intake / exhaust valve is displaced to a fully closed position at an end timing of an intake stroke in each cylinder after reaching the predetermined cranking rotational speed . A control device for an electromagnetically driven valve for an internal combustion engine configured to elastically support an intake / exhaust valve at a neutral position by an elastic body and to displace the intake / exhaust valve to a fully open position or a fully closed position by electromagnetic force. ,
At the start of starting, at least one of the intake valve and the exhaust valve is displaced from the neutral position to the fully open position, and held at the fully open position until reaching a predetermined cranking rotational speed,
The exhaust valve is displaced to the fully closed position at the start timing of the intake stroke in each cylinder after reaching the predetermined cranking rotational speed, and the intake valve is displaced to the fully closed position at the end timing of the intake stroke. A control device for an electromagnetically driven valve for an internal combustion engine. The control device for an electromagnetically driven valve for an internal combustion engine according to claim 1 or 2, wherein the displacement from the neutral position to the fully open position is performed when an ignition switch is turned on. The electromagnetic drive for an internal combustion engine according to any one of claims 1 to 3 , wherein the displacement from the neutral position to the fully open position is performed by exciting a natural vibration of an elastic body mass system by the electromagnetic force. Valve control device. Wherein the control for displacing the fully closed position, in any one of claims 1-4, characterized in that to start from the time just before the time required for the displacement of the fully closed position than the full closing timing required The control apparatus of the electromagnetically driven valve for internal combustion engines of description.

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