JP2005146945A - Engine automatic stop and start device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an automatic stop and start device capable of reducing burden of a starter and a battery by shortening the time required for restarting an engine from an idle stop condition. <P>SOLUTION: In an engine automatic stop and start controller for performing idle stop of the engine and restarting the engine from idle stop in accordance with an operation condition of a vehicle, a storage means for storing information related to a crank position at step S301 for determining idle stop conditions of the engine based on signals from various sensors to store the information related to the crank position in the storage means when the engine performs idle stop based on the results of determination at step S301. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to an engine automatic stop / start device.

In recent years, vehicles equipped with an engine automatic stop / start device have been known from the viewpoint of environmental considerations and energy saving (see, for example, Patent Document 1).
This engine automatic stop / start device idles the engine when the vehicle stops at a traffic light or when waiting for a signal or in order to reduce exhaust gas consumption or fuel consumption. Thus, the engine is restarted.
Japanese Patent Laid-Open No. 11-257123

  The above-described automatic engine stop / start device is excellent in that it can suppress fuel consumption due to useless idling, but information on the crank position is reset when the engine is stopped, so that the engine stroke is grasped at the time of restart. It is necessary to rotate the engine a few times. Therefore, it is necessary to perform the above-described cranking every time the engine is restarted from the idle stop, and there is a problem that the fuel consumption is deteriorated correspondingly and the burden on the starter is increased and the deterioration of the battery is promoted.

  Therefore, the present invention provides an automatic engine stop / start device that reduces the time required for restarting the engine from the idle stop state to reduce the burden on the starter and the battery.

According to the first aspect of the present invention, there is provided an engine automatic stop / start control apparatus that performs an idle stop and restart from an idle stop of an engine (for example, the engine E in the embodiment) in accordance with a driving state of the vehicle. Idle stop determination means (for example, step S301, step S601 in the embodiment) for determining the engine idle stop condition based on a signal from the sensor, and storage means (for example, in the embodiment, for example) An external memory 19) is provided, and information on the crank position is stored in the storage means when the engine is idle stopped based on the determination result of the idle stop determination means.
With this configuration, it is possible to accurately grasp the ignition and fuel injection timings when the engine is restarted.

According to a second aspect of the present invention, when restarting the engine from an idle stop, ignition and fuel injection control are started based on information on a crank position stored in the storage means.
With such a configuration, it is possible to reliably ignite in the first compression stroke.

The invention described in claim 3 is characterized in that the stored information is corrected immediately before ignition or fuel injection to the engine.
With this configuration, it is possible to perform ignition and fuel injection at an appropriate timing from the first rotation when the engine is restarted.

According to a fourth aspect of the present invention, a control circuit (for example, an implementation) that continues to supply power to the inside during the idling stop so that information relating to the crank position can be detected and the storage information of the storage means is retained. A power supply control circuit 14) according to the present embodiment is provided.
With this configuration, even if the crank position changes due to the inertial force after the engine is stopped, the crank position can be detected by the control circuit and the position information can be retained.

  In addition, as described in claim 5, the information on the crank position includes crank angle information and engine stroke information.

  According to the invention described in claim 1, since it is possible to accurately grasp the ignition and fuel injection timing at the time of engine restart, the drive time of the starter at the time of engine restart can be greatly shortened. The fuel efficiency is improved, the burden on the starter is reduced, and the battery can be prevented from deteriorating.

  According to the second aspect of the present invention, in addition to the effect of the first aspect, it is possible to surely ignite in the first compression stroke. There is an effect that can be done.

  According to the invention described in claim 3, in addition to the effect of claim 1 or 2, it is possible to perform ignition and fuel injection at an appropriate timing from the first rotation when the engine is restarted. As a result, the engine can be started quickly.

  According to the invention described in claim 4, in addition to the effect of any one of claims 1 to 3, even if the crank position is changed by inertial force after the engine is stopped, the crank position is detected by the control circuit and this is detected. Therefore, accurate crank position information after the engine is stopped can be obtained regardless of the idle stop time.

The best mode for carrying out the invention will be described in detail with reference to the drawings. Note that the engine automatic start / stop control device in the first embodiment controls, for example, idle stop and restart from idle stop of a single-cylinder engine E of a motorcycle.
As shown in FIG. 1, 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. The throttle valve 4 is provided with a throttle opening sensor 7 for detecting the opening. 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 secondary air valve 9 which is a solenoid type air control valve so that the amount of air flowing through the bypass passage 8 can be controlled.

Further, a crank angle sensor 11 that detects a rotational position of the crankshaft 10 (hereinafter referred to as a crank position) is attached to the engine E. 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.
The pulsar rotor 12 is provided with teeth at, for example, a position obtained by dividing the outer periphery into 18 equal parts, and a missing portion corresponding to three teeth is formed at one place. This missing area is used as a reference for the crank position.

The ECU 13 that is an electronic control unit of the engine E includes a power supply control circuit (control circuit) 14 and a CPU (not shown) that is a central processing unit, and is connected to a battery (BATT) 15 that is a power source of the ECU 13. Has been. The power supply control circuit 14 controls the internal power supply of the ECU 13. Specifically, the power supply from the battery 15 to the CPU is controlled by the ECU 13 even after the external power supply of the ECU 13 is cut off. Can be continued.
A crank angle sensor 11, a throttle opening sensor 7, an intake pressure sensor 5, a power supply voltmeter 21, a brake switch 22, a seat sensor 23, and a side stand switch 24 are connected to the input side of the ECU 13. In addition, an injector 6, an ignition circuit 16, a secondary air valve 9, and a starter relay 17 are connected to the output side of the ECU 13.
The ignition circuit 16 is connected to the spark plug 20 and applies a high voltage to the electrode of the spark plug 20 to ignite the air-fuel mixture compressed in the compression stroke described later.

  The starter relay 17 is connected to a starter motor M for starting the engine E, and drives and controls the starter motor M by turning on and off the power of the starter motor M. The starter motor M is configured to rotate the crankshaft via a gear (not shown).

Furthermore, an external memory (storage means) 19 is connected to the ECU 13. The external memory 19 stores information on a stage number or engine stroke, which will be described later, based on the signal from the crank angle sensor 11.
The ECU 13 functions as a means for determining whether or not the engine E can be automatically stopped, and a means for performing correction based on the notch position, as will be described later.

Next, an example of the operation in the engine E will be described with reference to the time chart of FIG.
The engine E is a four-cycle engine that sequentially repeats four strokes including an intake stroke, a compression stroke, an expansion stroke, and an exhaust stroke. The crankshaft 10 is configured to rotate twice (720 ° rotation) in the four strokes.
The pulse signal of the crank angle sensor 11 corresponds to the tooth position of the pulsar rotor 12 (for example, a position obtained by dividing the outer periphery into 18 equal parts), and the crankshaft 10 rotates 20 ° (= 18/360). Output every time. A region where no pulse signal is generated exists in the compression stroke and the exhaust stroke, and this corresponds to the missing portion of the pulsar rotor 12 described above.

  In the ECU 13, numbers (stage numbers) corresponding to the pulse signals (18 pulses × 2 = 36 pulses) for four strokes of the engine, that is, two rotations of the pulsar rotor 12 are sequentially assigned from 0 to 35. Count. The 14th to 16th stages (60 °, 3 pulses) corresponding to the missing part are counted as the 14th stage, and similarly, the 32nd to 34th stages are also counted as the 32nd stage. Then, the stage number is corrected when the 14th stage and the 32nd stage (reference stage) are counted.

  Specifically, when the engine is completely stopped at the 27th stage (indicated by a broken line and an arrow in the figure), after the engine stop command from the ECU 13, the engine is cut in fuel and the ignition is turned off. Continue engine rotation for a while. The signal level of the pulse signal decreases as the stop of the engine E approaches, that is, as the rotational speed of the pulsar rotor 12 decreases. Then, the ECU 13 cannot read the pulse signal before the engine E is completely stopped. Therefore, the ECU 13 recognizes a stage number slightly deviated from the 27th stage (for example, the 1st to 2nd stages) although the engine is actually stopped at the 27th stage.

  When the engine is restarted from a state where the external memory 19 stores a stage number slightly deviating from the 27th stage, the reference stage provided immediately before the ignition range (1st to 5th stages) in the compression stroke is The stage number is counted and the stage number is corrected.

Next, a process for automatically stopping the engine E will be described with reference to FIG.
First, in step S300, information from various sensors connected to the ECU 13 is read. Next, in step S301, it is determined by referring to the information in step S300 whether an idle stop condition is satisfied. When the determination result is “YES” (established), the process proceeds to step S302, and when the determination result is “NO” (not established), the process proceeds to step S305.

In step S302, the engine E is stopped because the idle stop condition is satisfied in step S301. Next, in step S303, reading of the pulse signal of the crank angle sensor 11 is continued in the ECU 13 until the engine E is completely stopped, and the process proceeds to step S304.
In step S304, the pulse signal of the last crank angle sensor 11 immediately before the engine E stops is read, the stage number corresponding to this pulse signal is stored in the external memory 19, and the process is terminated.
In step S305, since the conditions for idling stop are not satisfied, normal injection / ignition control is performed and the process is terminated.

Next, signal processing in the case of automatic restart from a state where idling is stopped in the intake or compression stroke will be described based on FIG.
First, in step S401, the ECU 13 reads the stage number stored in step S304 described above. In step S402, the starter motor M starts rotating, and at the same time, counting is started as a continuation of the stage number read in step S401, and the process proceeds to step S403. In step S403, the stage number error is corrected at the 32nd stage, which is the reference stage immediately before the compression stroke. In step S404, the engine E is ignited based on the stage number corrected in step S403.

Next, signal processing in the case of automatic restart from a state where idling is stopped in the expansion or exhaust stroke will be described based on FIG.
First, in step S501, the ECU 13 reads the stage number stored in step S304 described above. In step S502, at the same time when the starter motor M starts rotating, the stage number is counted as a continuation of the stage number read in step S501, and the process proceeds to step S503. In step S503, the stage number error is corrected in the 32nd stage, which is the reference stage immediately before the compression stroke. In step S504, fuel is injected into the intake port of the engine E based on the stage number corrected in step S503.

  According to the first embodiment described above, the step S301 for determining the idle stop condition based on the signals from the various sensors and the external memory 19 for storing the stage number when the engine E is stopped are provided. When the engine E stops idling based on the determination result, the stage number is stored in the external memory 19 so that the ignition and fuel injection timing at the restart from the idling stop can be accurately grasped. It becomes possible.

Further, when restarting the engine E from the idle stop, it is possible to ignite based on the stage number stored in the external memory 19, so that it is possible to prevent erroneous explosions at every ignition of the engine E. it can.
Then, by correcting the stage number in steps S403 and S503, it becomes possible to perform ignition and fuel injection at an appropriate timing from the first rotation when the engine E is restarted, thereby improving fuel efficiency and promptly. The engine E can be restarted.

  In addition, by providing the power supply control circuit 14 that can continuously detect the stage number and keep the stage number stored in the external memory 19 during the idle stop. Even if the crank position changes due to inertial force after the engine E stops and the stage number shifts, the power supply control circuit 14 can detect the crank position, count the stage number, and hold the stage number. Therefore, an accurate stage number after the engine E is stopped can be grasped regardless of the idle stop time.

Next, a second embodiment of the present invention will be described based on the flowchart of FIG. 6 with reference to FIGS. 1 to 5 (excluding FIG. 3).
Since the second embodiment is different only in the flowchart of FIG. 3 of the first embodiment described above, other description is omitted. This process also shows the process when the engine is stopped as in the first embodiment, but the stage number used in the process of step S304 in the first embodiment is replaced with the engine process. It is stored in the external memory 19. The following will be described in order.

  First, in step S600, information from various sensors connected to the ECU 13 is read. Next, in step S601, it is determined by referring to the information in step S600 whether an idle stop condition is satisfied. If the determination result is “YES” (established), the process proceeds to step S602. If the determination result is “NO” (not established), the process proceeds to step S605.

In step S602, the engine E is stopped because the idle stop condition is satisfied in step S601. Next, in step S603, reading of the pulse signal of the crank angle sensor 11 is continued in the ECU 13 until the engine E is completely stopped, and the process proceeds to step S604.
In step S604, the pulse signal of the last crank angle sensor 11 immediately before the engine E stops is read, the engine stroke is determined from the stage number corresponding to this pulse signal, and the engine stroke is stored in the external memory 19 for processing. Exit.
In step S605, since the conditions for idling stop are not satisfied, normal injection / ignition control is performed and the process is terminated.

  Therefore, according to the second embodiment, as in the first embodiment described above, step S601 for determining an idle stop condition based on signals from various sensors and the engine stroke at the time when the engine E is stopped. Is stored in the external memory 19 when the engine E is idling stopped based on the determination result of step S601. It is possible to accurately grasp the ignition and fuel injection timing.

Further, when the engine E is restarted from the idle stop, it is possible to ignite based on the engine stroke stored in the external memory 19, so that it is possible to prevent an accidental explosion caused by each ignition of the engine E. it can.
And by correcting the engine stroke in step S403 and step S503, it becomes possible to perform ignition and fuel injection at an appropriate timing from the first rotation when the engine E is restarted. The engine E can be restarted.

Further, the power supply control circuit 14 is provided which can detect the engine stroke by continuously supplying power to the inside during the idling stop and holds the engine stroke information stored in the external memory 19. Therefore, even if the crank position changes due to the inertial force after the engine E stops and the engine stroke shifts, the power supply control circuit 14 can detect the crank position and hold the engine stroke. Regardless of the stop time, an accurate engine stroke after the engine E is stopped can be grasped.
In particular, in the second embodiment, the capacity of the external memory 19 can be reduced because only the engine stroke number has to be used as compared with the first embodiment, which requires a number for each stage. In addition, the processing can be simplified.

  The present invention is not limited to the above-described embodiment. For example, the external memory 19 connected to the ECU 13 may be built in the ECU 13. The power supply control circuit 14 built in the ECU 13 may be externally connected.

It is a system configuration figure in a first embodiment of the present invention. It is a time chart in 1st embodiment of this invention. It is a flowchart of the engine stop process in 1st embodiment of this invention. It is a flowchart of the process at the time of engine starting in the intake or compression stroke in 1st embodiment of this invention. 6 is a flowchart corresponding to FIG. 4 during an expansion or exhaust stroke in the first embodiment of the present invention. 4 is a flowchart corresponding to FIG. 3 in the second embodiment of the present invention.

Explanation of symbols

E Engine 10 Crankshaft 14 Power supply control circuit (control circuit)
19 External memory (storage means)
Step S301, Step S601 Idle stop determination means

Claims (5)

  Idle stop determination means for determining an engine idle stop condition on the basis of signals from various sensors in an engine automatic stop / start control device that performs engine idle stop and restart from idle stop in accordance with the driving state of the vehicle And storage means for storing information relating to the crank position, wherein the information relating to the crank position is stored in the storage means when the engine is idle stopped based on the determination result of the idle stop determination means. Engine automatic stop start control device.   2. The engine automatic stop / start control device according to claim 1, wherein ignition and fuel injection control are started based on information related to a crank position stored in the storage means when the engine is restarted from an idle stop. 3. .   The engine automatic stop / start control apparatus according to claim 1 or 2, wherein the stored information is corrected immediately before ignition or fuel injection to the engine.   2. A control circuit is provided, wherein during the idling stop, a power supply to the inside is continued to enable detection of information relating to the crank position and to hold the storage information of the storage means. Item 4. The engine automatic stop / start control device according to any one of Items 3 to 4. The engine automatic stop / start control device according to any one of claims 1 to 4, wherein the information on the crank position includes crank angle information or engine stroke information.

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