JP3256260B2 - A method for detecting the power generation work of an alternator for idle speed control - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for detecting a power generation work of an alternator which is mounted on an engine of a car or the like and generates electric power sufficient to charge a battery.

[0002]

2. Description of the Related Art In recent automobiles, an alternator driven by using a part of the power of an engine is used for a battery charging system, and the output voltage of the alternator is used as an IC.
Generally, the adjustment is performed by a regulator. With such an alternator, the load on the engine differs between during power generation and when it is not.
Therefore, in controlling the engine, the power generation work of the alternator is detected, and the engine is controlled in consideration of the detected value.

In order to detect the power generation work of the alternator, the output current of the alternator may be measured. For example, the output current of the alternator is detected by current detecting means, for example, a current sensor, as in an engine speed control device disclosed in JP-A-2-146241.

[0004]

However, when the current sensor is used as described above, a microcomputer in the control device for controlling the engine is used in common to calculate the power generation work amount. Even if it is not necessary to provide the power generation work amount calculation means, it is not preferable because the manufacturing cost increases due to the current sensor. Also, usually, the alternator is configured so as to output a direct current with a built-in rectifying diode therein.For example, when a current transformer capable of detecting a current in a non-contact manner is used, a current transformer is used. It was necessary to prepare an alternator capable of incorporating a transformer, or to modify the alternator to provide an AC output, and it was difficult to configure the alternator at low cost.

[0005] An object of the present invention is to solve such a problem.

[0006]

In order to achieve the above object, the present invention takes the following measures. That is, the method of detecting the power generation work of the alternator for controlling the idle speed according to the present invention is a method of detecting the power generation work of the alternator driven by using a part of the power of the engine having the ignition plug. For each fixed section defined by a crank angle position including at least one ignition timing, the energizing time and the disconnection time of the field coil of the alternator are measured, and the total time of the energizing time and the disconnection time is measured. Calculate the amount of power generation work from the ratio of energization time, and calculate the ignition
When the ratio of the suspension coil is large, the idle rotation speed is corrected and controlled based on the calculated power generation work ,
The percentage of the ignition coil that occupies the entire electrical load
If the result is small, the calculated power generation work is smoothed.
The idle rotation speed is corrected and controlled based on the value obtained as described above. Furthermore, in order to improve the follow-up performance in the case of a large load change, when the value obtained by the smoothing process continuously increases or decreases a plurality of times, the calculated power generation work amount before the smoothing process is used. It is preferable that the idle speed be corrected and controlled based on the idle speed.

[0007]

With such a configuration, the energizing and disconnecting time of the field coil of the alternator is measured for each fixed section defined by the crank angle position including the ignition timing at least once. Since the amount of power generation work is detected from the time taken, it is not necessary to add a means for detecting the output current to the alternator, and the configuration can be made inexpensively. Moreover, since detecting the power generation amount of work in certain sections including the ignition timing, the ignition coil is a significant electrical loads, in other words the other
The electrical load of the
At the time of idle speed control in which the ratio of energy is large, such an influence as a load on the ignition coil can be reflected in real time. Further, if the ratio of the ignition coil for the entire electrical load is small, for example, when the ignition coil and the turn indicator or the headlights are turned on, since the process moderation calculation results, the influence of the ignition coil Even if the fluctuation due to the load fluctuation is large, the fluctuation can be absorbed, and the fluctuation of the idle speed can be prevented from changing little by little. Further, claim 2
According to the invention, when the value obtained by the averaging process is continuously increased or decreased a plurality of times, the idle speed is controlled by the power generation work calculated before the averaging process. In addition, it is possible to improve the followability when the load fluctuation is large.

[0008]

An embodiment of the present invention will be described below with reference to the drawings.

In FIG. 1, 1 is an alternator and 2 is an I
C regulator, 3 battery, 4 electronic control unit (E
/ G ECU).

The alternator 1 includes three stator coils L1 to L wound in a groove of the stator and connected in a three-phase star connection.
3 and a field coil Lf wound in a rotor rotatably supported inside the stator. The three-phase AC output from the stator coils L1 to L3 is full-wave rectified by diodes D1 to D6. Output. The cathodes of the diodes D1, D3, and D5 are connected to the positive electrode of the battery 3 and to the charging terminal B of the IC regulator 2. Also, diodes D2, D4, D6
Anode is grounded.

The IC regulator 2 has its power input terminal IG connected to its positive electrode for monitoring the terminal voltage of the battery 3, its field coil control terminal F connected to the field coil Lf of the alternator 1, and its electronic control. The phase signal input terminal P is connected to the stator coil L1. The two transistors Tr1 and Tr2 of the IC regulator 2 are turned on / off by a signal output from the IC 2a, and perform a known regulation operation by turning on / off one of the transistors Tr1. In other words, in this embodiment, by turning on the transistor Tr1, an exciting current flows through the field coil Lf of the alternator 1 (corresponding to the output of the ON signal Son to the electronic control unit 4). Stator coils L1 to L of alternator 1
3 to generate electric current. Further, a charging lamp (not shown) (connected to the terminal L) is turned on by turning on the other transistor Tr2.
That is, ON / OFF of the transistor Tr1 controls the power generation of the alternator 1 so that the terminal voltage of the battery 3 becomes constant, and is set to the terminal voltage of the battery 3 input to the power input terminal IG and the IC 2a. The target voltage is compared with a target voltage (for example, 14.5 V). If the terminal voltage is lower than the target voltage, the terminal is turned on, and if the terminal voltage is higher, the terminal is turned off. As described above, when the transistor Tr1 is turned on, the on signal Son is output from the field coil control terminal F to the electronic control unit 4, and when the transistor Tr1 is turned off, the off signal S is output.
off is output. The diode D1
A series-connected body 5 composed of two diodes D7 and D8 provided in parallel to .about.D6 is a neutral point diode, and reduces potential fluctuations generated at the neutral points of the stator coils L1 to L3 when the alternator 1 operates. To achieve effective use of energy.

The electronic control unit 4 is mainly composed of a microcomputer. One port of the input interface is connected to a field coil control terminal F of the IC regulator 2, and the other port is connected to the vehicle speed. Sensors for controlling the engine, such as sensors and crank angle reference position sensors built in the distributor, are connected. The electronic control unit 4 includes:
Energizing time To of the field coil Lf of the alternator 1
n and the power-off time Toff, and the power-on time Ton
Energizing time To with respect to the total time of
A program for calculating the power generation work amount FDUTY by calculating the ratio of n is included.

In the above configuration, detection of the power generation work amount FDUTY of the alternator 1 is performed based on an ON / OFF ratio of the FDUTY signal composed of the ON signal Son and the OFF signal Soff per unit time. Specifically, the time from the top dead center TDC of the piston to the next top dead center TDC is defined as one unit time. This is because the energy consumed by the ignition plug in an idling state or a state with a small electric load is larger than that consumed by the electronic control unit 4, the fuel injection valve or the fuel pump, and the FDUTY from the field coil control terminal F. The on / off switching timing of the signal is substantially synchronized with the ignition timing. The detection of the top dead center TDC is performed using an N (cylinder discrimination) signal indicating the compression top dead center output from the crank angle reference position sensor. Then, the electronic control unit 4 turns ON / OFF the duration of the FDUTY signal from the field coil control terminal F, which is input to the input interface by the built-in counter, tonα, toffα (α).
Is a positive integer). In this case, there are two counters for individually measuring the respective durations tonα and toffα, and each counter can count and accumulate the time and is cleared at the timing of the top dead center TDC. I do. This duration tonα, t
As shown in FIG. 2, the measurement of offα is performed in a section MP between the top dead center TDC and the next top dead center TDC, during which the sum of the duration tonα of the ON signal Son and the OFF signal S
The sum of the duration time toffα of the off time is used as a power generation work amount to be described later as an energization time Ton of the field coil Lf and a power cutoff time Toff.

The power generation work amount FDUTY of the alternator 1
Is a crank that includes at least one ignition timing
Time Tm of section MP that is a fixed section defined by the angular position
It is detected by the ratio of the energization time Ton to p (= Ton + Toff), and is calculated by the following equation. FDUTY (%) = Ton x 100 / Tmp = Ton x 100 / (Ton + Toff)

In the case shown in FIG. 2, an ON signal Son is output in response to ignition (indicated by an arrow I in the figure), and the alternator 1 generates power each time.
There is an intermediate timing from the previous ignition to the next ignition in the middle of this, and in that portion, the off signal Soff is output, and the alternator 1 may stop generating power.
The electronic control unit 4 determines the duration of the ON signal Son and the OFF signal Soff output from the IC regulator 2.
tonα and toffα are counted by a counter. In this case, the counter uses the top dead center TDC
Is received, the duration ton1 of the ON signal Son1 is measured, then the duration toff of the OFF signal Soff is measured, and the duration ton2 of the ON signal Son2 is measured as the next top dead center TDC. Clock until signal is input. And the obtained signals Son
1, Son2, Soff duration ton1, ton
2, the power generation work amount FDUTY of the alternator 1 is calculated as follows. Ton = t on1 + t on2 Toff = t off FDUTY (%) = Ton × 100 / (Ton + Toff) = (t on1 + t on2) × 100 / (t on1 + t on2 + t off)

By repeatedly performing these calculations, the amount of power generation work FDUTY of the alternator 1 during operation of the engine is performed.
Is detected in real time. Detected power generation work F
DUTY is used for engine idling control and the like.

In the detection of the power generation work amount FDUTY described above, an ignition coil is mainly used as an electric load. However, when another electric load, such as a turn signal indicator or a headlight, is turned on, the entire electric load is detected. As shown in FIG. 3, there is a possibility that the ratio of the ignition coil to the power generation work amount FDUTY (hereinafter referred to as a detected direct value DFD) is increased or decreased every time the detected value of the power generation work amount FDUTY is detected. It becomes difficult. Therefore, an averaging process is performed using the following equation in order to absorb variations in the detected direct value DFD.

FDUTY _n (%) = FDUTY _n + (FDUTY _n−1 −FDUTY _n ) / N where N is a smoothed number, FDUTY _n is the power generation work amount detected this time, and FDUTY _{n −1} is the last time detected. Power generation work.

When the averaging process is performed as described above, FIG.
As shown in the figure, the averaged power generation work FDAV indicates that the detected direct value DFD suddenly becomes 100%,
While the value is close to 0%, it is a value that does not greatly differ from the value detected last time.
Change becomes small and becomes stable. Therefore,
When this is used for controlling the engine, since the detected power generation work amount FDUTY does not suddenly change, smooth control can be performed without, for example, changing the idling speed every moment.

The present invention is not limited to the embodiment described above. For example, when averaging the power generation work amount FDUTY, as described above, instead of calculating by FDUTY _n (%) = FDUTY _n + (FDUTY _n-1 -FDUTY _n ) / N, the following expression FDUTY _n (% _{) = FDUTY n + FDUTY n-} 1 + ...... + FDUTY nN / ( or may be computed by n +1).

In each of the above embodiments, the detection of the power generation work FDUTY or the averaged power generation work FDAV has been described. However, the power generation work FDUTY of the alternator 1 is used for controlling the engine. In this case, the change state of the detected direct value DFD may be determined, and the power generation work FDUTY and the averaged power generation work FDAV may be selected and used based on the result. For example, as shown in FIG. 4 (a), when the detected direct value DFD varies, the averaged power generation work FDAV increases once but decreases with the next value falling below it. Therefore, in such a case, the averaged power generation work FDAV is used. Conversely, when the averaged power generation work amount FDAV continuously increases as shown in FIG.
Since the actual electric load fluctuates, for example , it is determined that the averaged power generation work amount FDAV has increased twice in succession, and in that case, the power generation work amount FDUTY which is a detected direct value is used. And With such a configuration, the power generation work of the alternator 1 can be stably detected, and the responsiveness of the detection can be improved.

In addition, the configuration of each section is not limited to the illustrated example, and various modifications can be made without departing from the spirit of the present invention.

[0023]

As described in detail above, the present invention measures the energization and disconnection time of the field coil of the alternator and detects the amount of power generation work from the ratio of the measured time. There is no need to attach a means for detection to the alternator, and no wiring or the like is required, so that the configuration can be made inexpensively.
Moreover, since the power generation work amount is detected in a certain section including the ignition timing, it is possible to reflect the influence of the load of the ignition coil in real time during idle speed control in which the ignition coil becomes a large electric load. it can. In addition, electrical loads
The ratio of the ignition coil to the whole is small
In some cases, the result of the operation is smoothed and
Since idle speed control is performed based on the value, the ignition
The effect of the application coil is small, and the variation due to load fluctuation
Can be absorbed even if the
Small changes in the number of turns can be prevented.

[Brief description of the drawings]

FIG. 1 is a schematic electric circuit diagram showing one embodiment of the present invention.

FIG. 2 is a waveform chart showing detection timing in the embodiment.

FIG. 3 is an operation explanatory view of the embodiment.

FIG. 4 is an operation explanatory view of another embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Alternator 2 ... IC regulator 3 ... Battery 4 ... Electronic control device Lf ... Field coil

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) H02J ⁷ /14-7/24 F02D 29/00-29/06 F02D 43/00-45/00 395 H02P 9 / 00-9/48

Claims (2)

(57) [Claims] 1. A method for detecting a power generation work amount of an alternator driven by using a part of power of an engine having an ignition plug, wherein ignition timing is defined by a crank angle position including at least one time. for each given interval, measures the energizing time of the alternator field coil and deenergized time, calculates the power generation workload from the ratio of conduction time to the total time between the vent charging time and deenergized time, electrostatic
Ratio of ignition coil to total air load
Is large, the idle speed is corrected and controlled based on the calculated power generation work amount, and the ignition
If the ratio of the cushion coil is small,
Based on the value obtained by smoothing the generated power work
A method for detecting the power generation work of an alternator for idle speed control, characterized by correcting and controlling the engine speed. 2. The method according to claim 1, wherein the value obtained by the smoothing processing is continuously increased plural times.
When ascending or descending, calculate the calculated
2. The method according to claim 1, wherein the idling speed is corrected and controlled based on the amount of electric work .