JP4040569B2 - Engine automatic start / stop control device - Google Patents

Description

  The present invention relates to an engine automatic start / stop control device that automatically stops or automatically restarts an engine of a vehicle under a predetermined condition.

In recent years, for the purpose of reducing exhaust gas and reducing fuel consumption, vehicles have been developed that automatically stop the engine when the vehicle is stopped, that is, idle stop (see, for example, Patent Document 1). In this type of vehicle, for example, when the driver operates the accelerator during automatic stop, the engine is automatically restarted. Specifically, the crankshaft is rotated by a starter, and the air-fuel mixture is drawn into the engine, and then the air-fuel mixture is ignited by a spark plug.
Japanese Patent Laid-Open No. 11-257123

However, when the engine is automatically restarted, the driver may feel uncomfortable if the air-fuel mixture is ignited and the time required to restart the engine is long after the driver performs an accelerator operation. . For this reason, it is desired to restart the engine promptly at the time of automatic restart.
This invention is made in view of such a subject, and aims at improving the restartability of an engine.

The invention according to claim 1 of the present invention for solving the above-described problems is an engine automatic start / stop control for automatically stopping and automatically restarting a single-cylinder engine (for example, the engine E of the embodiment) according to the driving state of the vehicle. In the apparatus, when the engine is automatically restarted, after energization of the ignition coil (for example, the ignition coil 15 of the embodiment) connected to the ignition plug (for example, the ignition plug 14 of the embodiment) of the engine is started. An automatic engine start / stop control device comprising automatic restart control means (for example, ECU 16 of the embodiment, steps S3 and S4) for operating the engine start device (for example, the starter 26 of the embodiment), did.
According to this engine automatic start / stop control device, energization to the ignition coil is started before the starter is operated when a predetermined automatic restart condition is satisfied during automatic engine stop. As a result, the current necessary for spark discharge from the spark plug can be supplied to the ignition coil until the ignition timing for igniting the air-fuel mixture is reached. Therefore, the air-fuel mixture can be reliably ignited in the first compression stroke at the time of automatic restart.

According to a second aspect of the present invention, in the engine automatic start / stop control device according to the first aspect, when the engine is automatically stopped, a crankshaft (for example, the crankshaft 10 of the embodiment) provided in the engine is compressed. It has stop position control means (for example, air control valve 9 of embodiment, ECU16) which stops at the rotation position equivalent to a stroke, It is characterized by the above-mentioned.
According to this engine automatic start / stop control device, the crankshaft is stopped at the rotational position corresponding to the compression stroke by the stop position control means, so that the time until the ignition timing is reached after the engine is automatically restarted is shortened. be able to. Even in such a case, as described above, the automatic restart control means energizes the ignition coil with a current that enables spark discharge by the spark plug until the ignition timing is reached.

According to a third aspect of the present invention, there is provided an automatic engine start / stop control device for automatically stopping and restarting a single cylinder engine in accordance with a driving state of a vehicle, and information relating to a rotational position of a crankshaft when the engine is automatically stopped. When the storage means (for example, the external memory 30 of the embodiment) and the engine are automatically restarted, the crankshaft is rotated from the rotational position of the crankshaft at the time of automatic stop to the rotational position corresponding to the ignition timing. When calculating means (for example, ECU 16 of the embodiment, step S14) for calculating the time required for rotation, and the time calculated by the calculating means is shorter than the time required for energizing the ignition coil, Automatic operation of starting the engine starting device after energizing the ignition coil connected to the ignition plug of the engine Having a starting control means and the engine automatic start stop control apparatus according to claim.
In this engine automatic start / stop control device, the rotational position of the crankshaft is stored when the engine is automatically stopped, the time is calculated up to the ignition timing based on this, the timing to start energizing the ignition coil, and the starter is operated. Control the timing. Here, the information related to the rotational position of the crankshaft may be the rotational position of the crankshaft itself or the engine stroke (for example, the intake stroke) estimated from the rotational position of the crankshaft. In addition, when there is a margin in the time from the automatic engine restart to the ignition timing, the starter may be operated first, or the starter may be operated and the ignition coil may be energized at the same time. .

According to the first aspect of the present invention, the automatic restart control means operates the starter after energizing the ignition coil with the necessary current when the engine is automatically restarted. Can be ignited. Therefore, the restartability of the engine is improved. In addition, since it is possible to always ensure the time for supplying the necessary current to the ignition coil, transistor ignition is possible, and the number of components of the ignition device can be reduced and the price can be reduced.
According to the second aspect of the invention, in addition to the effect of the first aspect, the crankshaft is stopped at the rotational position corresponding to the compression stroke at the time of automatic stop, so that the engine is easily started at the time of automatic restart.
According to the invention described in claim 3, the rotational position of the crankshaft at the time of automatic stop is stored, and when the time for energizing the current necessary for the ignition coil is insufficient, Since the starter is operated, ignition can be reliably performed in the first compression stroke. Therefore, the restartability of the engine is improved. In addition, since it is possible to always ensure the time for supplying the necessary current to the ignition coil, transistor ignition is possible, and the number of components of the ignition device can be reduced and the price can be reduced.

The best mode for carrying out the invention will be described in detail with reference to the drawings.
FIG. 1 shows a schematic configuration of an engine automatic start / stop control apparatus according to the first embodiment.
The engine automatic start / stop control device in this embodiment controls automatic stop and automatic restart of a single-cylinder engine E of a motorcycle.
An intake passage 2 is connected to the intake port 1 of the engine E. The intake passage 2 includes an air cleaner 3 on the upstream side. A throttle valve 4, an intake pressure sensor 5, and an injector 6 for fuel injection are sequentially provided at the subsequent stage of the air cleaner 3. A throttle angle sensor 7 for detecting the opening degree is attached to the throttle valve 4. The intake passage 2 is provided with a bypass passage 8 that bypasses the throttle valve 4 from upstream to downstream. The bypass passage 8 is provided with a solenoid-type air control valve 9 so that the amount of air flowing through the bypass passage 8 can be controlled.

The engine E is attached with a crank angle sensor 11 that detects a rotational position of the crankshaft 10 (hereinafter referred to as a crank position). The crank angle sensor 11 is an electromagnetic pickup that outputs a pulse signal each time the teeth of the pulsar rotor 12 that rotates integrally with the crankshaft 10 pass. In addition, the pulsar rotor 12 in this embodiment has a configuration in which 15 teeth are provided in order at positions where the outer periphery is equally divided, and the remaining 3 teeth are omitted. This missing portion is used as a reference for the crank position.
Further, a spark plug 14 for igniting the air-fuel mixture is attached to the combustion chamber 13 of the engine E. An ignition coil (ignition device) 15 is connected to the ignition plug 14.

  An ECU (electronic control unit) 16 that mainly controls the engine E includes a CPU (central processing unit), a memory, and the like. As shown in FIG. 2, on the input side of the ECU 16, there are a crank angle sensor 11, a throttle opening sensor 7, an intake pressure sensor 5, a power source voltmeter 21, a brake switch (brake SW) 22, and a side stand switch (side stand SW). ) 24 is connected. Further, an injector 6, an ignition coil 15, an air control valve 9, and a starter relay 25 are connected to the output side of the ECU 16. Further, the ECU 16 is connected to an external memory 30 and can store predetermined information. The external memory 30 stores, for example, data on the time required for energizing the ignition coil 15. As will be described later, the ECU 16 functions as an automatic restart control means for controlling the energization timing to the ignition coil 15 and the operation timing of the starter 26. Further, in cooperation with the air control valve 9, it functions as an automatic stop control means for automatically stopping the crankshaft 10 at a predetermined rotational position.

Next, an example of the operation of the engine E will be described with reference to the timing chart of FIG. Note that FIG. 3 shows that the stroke, the output of the crank angle sensor 11 and the stage set based on the stroke, and the energization of the ignition coil in the engine operating continuously over time. It is illustrated.
As shown in FIG. 3, the engine E is a four-cycle engine that sequentially repeats an intake stroke, a compression stroke, an expansion stroke, and an exhaust stroke. The pulse signal output from the crank angle sensor 11 with the rotation of the crankshaft 10 is output every time the crankshaft 10 rotates 20 °. Note that there is a region where no pulse is generated in the compression stroke and the exhaust stroke, and this corresponds to a portion where the teeth of the pulsar rotor 12 are missing.

  Such a pulse signal is input to the ECU 16. The ECU 16 counts the number of teeth from the acquired pulse signal with reference to a portion where the teeth of the pulsar rotor 12 are missing. As shown in FIG. 3, the count value (hereinafter referred to as a stage) ranges from 0 to 35, and 14 to 16 and 32 to 34 correspond to portions where teeth are missing. Further, while the stage is in the compression stroke from 33 to 1, the ECU 16 starts energizing the primary side of the ignition coil 15 (ON), whereby the current necessary for ignition is connected to the ignition coil 15. Become so. This current is cut off (OFF) when the count value reaches 1, and the spark plug 14 is sparked by the high voltage generated on the secondary side of the ignition coil 15 at this time, and the mixing in the combustion chamber 13 is performed. Qi is ignited. The ignition timing is when the energization of the ignition coil 15 is turned off. Further, the time (dwell time) from when the energization to the ignition coil 15 is turned on to when it is turned off is usually several milliseconds to several tens of milliseconds, and varies depending on the rotational speed of the engine E. The distinction between the compression stroke and the exhaust stroke is determined by monitoring the rotation of the camshaft (not shown) and the fluctuation of the intake pressure in addition to the output of the crank angle sensor 11.

Further, a process for automatically stopping or automatically restarting the engine E will be described.
The automatic stop start condition is a condition in which the vehicle stops and the engine E enters an idle state. Such a start condition is predetermined for each vehicle and is, for example, a logical product of the conditions listed below. That is, the engine speed detected by the throttle angle sensor 11 is about 1200 rpm, the throttle opening is fully closed, the intake pressure is idle intake pressure, and the voltage value of the power supply voltmeter is the operation of the engine E. It is a voltage indicating the inside, the brake switch 22 is ON (a state where the brake is held), and the side stand switch 24 is ON (a state where the side stand is raised).

  When the automatic stop start condition is satisfied, for example, the ECU 16 stops energization to the ignition circuit 15 to stop ignition and stop fuel injection. When the crankshaft 10 that rotates by inertia enters the rotational position corresponding to the intake stroke, the air control valve 9 of the bypass passage 8 of the intake passage 2 is opened, and the air-fuel mixture is supplied to the combustion chamber 13. Inhale. The air sucked into the combustion chamber 13 together with the fuel acts to stop the piston 17 from rising, and as a result, the engine E stops in the middle of the compression stroke.

  The automatic restart condition, that is, the automatic stop release condition is, for example, that the throttle opening sensor 7 detects a predetermined throttle opening, and the other sensors 4, 11 and 21 and switches shown in FIG. The conditions 22 and 24 are the same as the conditions at the time of automatic stop. The predetermined throttle opening is an opening at which it can be considered that the driver's intention to drive the vehicle appears.

  Here, when the automatic restart start condition is satisfied, if the rotational position of the crankshaft 10 during automatic stop is between 34 and 1 on the stage of FIG. When restarted, it is not possible to secure time for energizing the ignition coil 15 with a necessary current. As a specific example, when the stage at the automatic stop position is 34, the ignition timing comes after the elapse of 3 stages. Therefore, when the ignition coil 15 is energized when the engine E is restarted, It is not possible to secure the time for four stages necessary for energizing the coil 15. For this reason, although the mixture is sucked into the combustion chamber 13 before the engine E is automatically stopped, the mixture cannot be ignited in this compression stroke, and the engine E is continuously rotated by the starter 26. In this compression stroke, the air-fuel mixture is ignited, and it takes a long time until the automatic restart is actually completed after the automatic restart condition is satisfied. In order to eliminate such inconvenience, in this embodiment, the energization timing to the ignition coil 15 and the operation timing of the starter 26 are adjusted. Such control will be described below with reference mainly to the flowchart of FIG.

First, the ECU 16 reads information from the various sensors 4, 7, 11, 21 and the switches 22, 24 (step S 1), and when the above-described automatic restart condition is satisfied (YES in step S 2), the ECU 16 Then, energization to the ignition coil 15 is started (step S3). Further, when a predetermined time (for example, several milliseconds to several tens of milliseconds) elapses, the ECU 16 energizes the starter relay 25 (step S4), and rotates the starter 26 (see FIG. 1).
As shown in FIG. 1, when the starter 26 rotates, the crankshaft 10 is rotated accordingly. In this embodiment, since the crankshaft 10 is stopped in the compression stroke, the piston 17 compresses the air-fuel mixture in the combustion chamber 13 by the rotation of the crankshaft 10. When the predetermined ignition timing is reached, the ignition coil 15 is already in an ignitable state. Therefore, when the ECU 16 cuts off the power supply to the ignition coil 15, a high voltage is generated and the spark plug 14 is discharged. . Accordingly, the air-fuel mixture is ignited at a predetermined ignition timing, and the engine E is restarted quickly.

  If the automatic restart condition is not satisfied (NO in step S2), the process here is terminated. In this case, the process shown in FIG. 4 is repeatedly performed at predetermined time intervals until the automatic restart condition is satisfied.

  According to this embodiment, the starter 26 is operated after energization of the ignition coil 15 is started. Therefore, when the crankshaft is rotated, the time from the automatic restart to the ignition timing is very short. Even if it exists, the time required for ignition can be secured. Therefore, the air-fuel mixture can be reliably ignited in the first compression stroke at the time of automatic restart. For this reason, there are many components and it is not necessary to perform expensive CDI (capacity discharge ignition), and there are few components and inexpensive transistor ignition is attained. Further, since the ignition can be surely performed in the first compression stroke immediately after the automatic restart is started, there is an advantage that the operation time of the starter 26 can be shortened.

  The engine automatic start / stop control device may be configured such that the ECU 16 and the air control valve 9 do not automatically stop the engine E during the compression stroke. In this case, the crankshaft 10 may stop at a rotational position corresponding to the intake stroke, the exhaust stroke, or the like. However, by energizing the ignition coil 15 prior to the starter 26 being started, Can be reliably ignited.

Next, a second embodiment of the present invention will be described in detail with reference to the drawings. In addition, the same code | symbol is attached | subjected to the component same as 1st Embodiment, and the overlapping description is abbreviate | omitted.
The engine automatic start / stop control device in this embodiment is characterized in that the start timing of the starter 26 is changed in accordance with the rotational position of the crankshaft 10 at the time of automatic stop. Therefore, the stage at the time of automatic stop is stored in the external memory 30 (see FIG. 2).

  In the engine automatic start / stop control device, the ECU 16 automatically stops the engine E when the automatic stop start condition is satisfied. In this case, for example, the energization to the ignition coil 15 is stopped and the fuel supply is stopped. Then, the ECU 16 stores the count value (stage) of the crank position at the time of automatic stop in the external memory 30.

  Then, the processing when the engine E is restarted after the automatic stop is to make the ignition coil 15 operable until the ignition timing, as in the first embodiment described above. This will be described below with reference to the flowchart of FIG.

First, the ECU 16 reads information from the various sensors 4, 7, 11, 21 and the switches 22, 24 (step S 1), and determines whether or not the above automatic restart start condition is satisfied (step S 2).
If automatic restart is possible (YES in step S2), the ECU 16 reads from the external memory 30 a stage corresponding to the crank position when the engine E is automatically stopped (step S13). Then, the time required for the crankshaft 10 to rotate from the crank position at the time of automatic stop to the crank position corresponding to the ignition timing is calculated (step S14).

If the time to ignition calculated in step S14 is shorter than the time required to energize the ignition coil 15 with the current required for ignition of the air-fuel mixture (YES in step S15), the ignition coil 15 is first applied. Is started (step S16). Then, after a predetermined time (for example, several milliseconds to several tens of milliseconds) has elapsed, the starter relay 25 is energized (step S17). As a result, the starter 26 (see FIG. 1) operates and the crankshaft 10 rotates.
On the other hand, if the time to ignition calculated in step S14 is longer than the time required to energize the ignition coil 15 with the current required for ignition of the air-fuel mixture (NO in step S15), the starter relay 25 is supplied. Simultaneously with the energization, the energization of the ignition coil 15 is started (step S18).
When the crankshaft 10 rotated by the starter 26 is rotated to a position corresponding to the ignition timing, the ECU 16 cuts off the current that has been previously supplied to the ignition coil 15 to generate a high voltage and ignite the air-fuel mixture. To do. Thereby, the engine E restarts rapidly.

  If the automatic restart condition is not satisfied (NO in step S2), the process here is terminated. In this case, the process as shown in FIG. 5 is repeatedly performed at predetermined time intervals until the automatic restart condition is satisfied.

According to this embodiment, when the engine E is automatically restarted, the ECU 16 calculates the time from the restart of the engine E to the ignition timing, and supplies the ignition coil 15 with a current necessary for ignition. When it is determined that there is not enough time to start, the starter 26 is operated after energization of the ignition coil 15 is started, so that the time required for ignition can be secured, and the first time during automatic restart It is possible to ignite reliably in the compression stroke. Therefore, there are few components and inexpensive transistor ignition is possible.
Further, when the ECU 16 determines that the time for energizing the ignition coil 15 can be secured, the starter 26 is immediately operated, so that the ECU 16 can operate at an appropriate timing according to the rotational position of the crankshaft 10 at the time of automatic stop. The engine E can be automatically restarted quickly. Here, as shown in step S18 of FIG. 4, the ignition coil 15 is energized simultaneously with the starter relay 25. However, the ignition coil 15 may be energized after the starter relay 25 is energized. .

The present invention can be widely applied without being limited to the above-described embodiments.
For example, the ECU 16 controls the energization timing to the ignition coil 15 and the energization timing to the starter relay 25 based on the stage value of the rotational position of the crankshaft 10 at the time of automatic stop (for example, step S15), the stroke specified from the stage or the like is stored in the external memory 30, and when the stroke at the time of automatic stop is the compression stroke, the ignition coil 15 is energized first, and the stroke of the other strokes In this case, the starter relay 25 may be energized immediately.

It is a schematic block diagram of the engine automatic start / stop control device in the embodiment of the present invention. It is a figure which shows an example of ECU and the apparatus connected to ECU. It is a timing chart which shows operation | movement of an engine. It is a flowchart which shows the process of an engine automatic start / stop control apparatus. It is a flowchart which shows the process of an engine automatic start / stop control apparatus.

Explanation of symbols

9 Air control valve (stop position control means)
10 crankshaft 14 spark plug 15 ignition coil 16 ECU (automatic restart control means, stop position control means)
26 Starter (starting device)
30 External memory S3 Step of starting energization of ignition coil S4 Step of starting energization of starter relay S14 Step of calculating crank position and time until ignition when engine E is automatically stopped

Claims (3)

In the engine automatic start / stop control device for automatically stopping and automatically restarting the single cylinder engine according to the driving state of the vehicle,
In order to automatically restart the engine, the engine automatic control system has an automatic restart control means for operating the engine starting device after energizing the ignition coil connected to the ignition plug of the engine. Start / stop control device. The engine automatic start / stop control device according to claim 1, further comprising stop position control means for stopping a crankshaft provided in the engine at a rotational position corresponding to a compression stroke when the engine is automatically stopped. . In the engine automatic start / stop control device for automatically stopping and automatically restarting the single cylinder engine according to the driving state of the vehicle,
Storage means for storing information related to the rotational position of the crankshaft when the engine is automatically stopped, and a rotational position corresponding to the ignition timing from the rotational position of the crankshaft when the engine is automatically restarted. Calculating means for calculating the time required for the crankshaft to rotate, and when the time calculated by the calculating means is shorter than the time required for energizing the ignition coil to the ignition plug of the engine An engine automatic start / stop control device comprising: an automatic restart control means for operating the engine start device after energization of the connected ignition coil is started.

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