JP2002031021A - Engine power generation system and its controller - Google Patents

Abstract

(57) [Problem] To provide a small engine power generation system having high power generation efficiency and a controller thereof. A generator 2 driven by an engine 1 is provided.
And a starter motor 8 for cranking the engine 1
And a controller 4 for supplying a drive voltage depending on electric power supplied from the generator 2 and the battery 5 to an electric load including the starter motor 8, and the controller 4 supplies ignition energy to an ignition coil 5 of the engine. The controller 4 includes an igniter 43, and a drive obtained by connecting a power supply line of a generator and a power supply line of a battery in parallel so that the drive voltage of the igniter 43 does not decrease when the starter motor 8 is driven. Supply the voltage to the power line of the igniter.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an engine power generation system for rotating a generator by an engine and a controller thereof, and more particularly to an engine power generation system for starting an engine by a starter motor and a controller thereof.

[0002]

2. Description of the Related Art In recent years, in order to improve the power generation efficiency of an engine generator, on-timing for starting power supply from the igniter to the primary side of the ignition coil, and shutting off power supply from the igniter to reduce the ignition coil The off timing for generating a high voltage to the next side is controlled by a microcomputer (CPU).

Here, the microcomputer detects that the engine rotation angle has reached a predetermined angle based on the output signal of the pulsar coil, and calculates the on-timing and the off-timing from this time based on the engine speed and the like. Further, the igniter is driven from the ON timing to the OFF timing to supply ignition energy to the primary side of the ignition coil.

On the other hand, in an engine generator in which the engine is started by a starter motor, when the starter motor is driven at the time of starting the engine, power consumption is instantaneously increased due to generation of an inrush current and the battery voltage is temporarily reduced.
For this reason, in the power generation system that supplies power to the microcomputer from a battery, the operation of the microcomputer may become unstable when the engine is started, or the microcomputer may be reset.

In order to solve such a problem, in a conventional engine generator, an exciter winding is provided separately from the main winding in the generator, and power is supplied to the microcomputer from the exciter winding. Was.

[0006]

The drive time of the igniter also depends on its power supply voltage. If the drive time of the igniter, that is, the interval between the ON timing and the OFF timing becomes longer because the power supply voltage is low, the CPU can calculate. Time will be short. As a result, the CPU cannot calculate the timings accurately, and it is difficult to improve the power generation efficiency.

On the other hand, if power is supplied to the microcomputer from the exciter winding, the power supply voltage of the microcomputer does not decrease even when the engine is started by the starter motor. However, in order to generate the operation-guaranteed voltage of the microcomputer even at the cranking rotation speed at the time of engine start, the size of the exciter winding must be increased, and an excessive voltage is generated when the engine rotates at a high speed.

An object of the present invention is to solve the above-mentioned problems of the prior art and to provide a small-sized engine power generation system having high power generation efficiency and a controller thereof.

[0009]

Means for Solving the Problems In order to achieve the above object, the present invention is characterized in that the following means are taken.

(1) The engine power generation system according to the present invention comprises: a generator driven by the engine; a starter motor for cranking the engine; and a starter motor having a drive voltage dependent on the power supplied from the generator and the battery. And a controller for controlling an electric load, the controller including a voltage drop suppressing unit for suppressing a drive voltage drop when the starter motor is driven.

(2) The controller of the engine power generation system according to the present invention supplies a drive voltage depending on the power supplied from the engine generator and the battery to the starter motor of the engine, and suppresses a decrease in the drive voltage when the starter motor is driven. It is characterized by including voltage drop suppressing means.

According to each of the above-mentioned features, even if the power consumption of the battery increases and the battery voltage decreases when the starter motor is driven, the drive voltage supplied to the electric load by the controller does not decrease. As a result, the voltage applied by the controller to the ignition coil can be maintained high, and the ignition energy can be supplied from the controller to the primary side of the ignition coil in a short time. Therefore, sufficient time for the CPU of the controller to calculate the ignition timing and the like can be sufficiently secured, and an engine power generation system with high power generation efficiency can be realized.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail with reference to the drawings. FIG. 1 is a block diagram of an engine power generation system according to an embodiment of the present invention. The power generator 2 is driven by an engine 1, a transformer 3 that reduces an output voltage of the generator 2, and an output from the transformer 3. Generated voltage V
The main components are a controller 4 to which the gene and the output voltage Vbatt of the battery 5 are supplied, an ignition coil 6 and an ignition plug 7 driven by the controller 4, and a starter motor 8 for cranking the engine 1.

The controller 4 includes a rectifier circuit 41 for rectifying the generated voltage Vgene supplied from the transformer 3, an igniter 43 for supplying ignition energy to the temporary side of the ignition coil 6 and a power supply 44 thereof, and a starter motor 8. A driver 45 for supplying a drive current to the engine 1, a temperature sensor 48 for detecting the temperature of the engine 1, a pulsar coil 49 for detecting a rotation angle of the engine 1, and the igniter 43 and the driver 45 based on the engine temperature and the engine rotation angle. 46 for controlling power supply and its power supply 47
And a limiting circuit 42 for limiting the output voltage and output current of the rectifier circuit 41.

FIG. 2 shows an igniter 4 according to this embodiment.
3 (voltage at point A in FIG. 1) and engine speed Ne
FIG. 3 is a diagram showing the relationship with
Is the ON time of the igniter 43 in the present embodiment,
FIG. 9 is a diagram showing a comparison with a conventional technique.

In the engine power generation system shown in FIG. 1, the engine 1 is cranked by the starter motor 8 at the time of starting. However, as shown in FIG.
Is lower than the engine speed after the complete explosion. For this reason, conventionally, the generator 2 is equipped with a relatively large exciter coil so that the generator 2 can generate the required ignition voltage Vmin even at the cranking speed Nc. Therefore, when the engine reaches a high rotation state, an excessive voltage is generated.

On the other hand, the generator 2 of this embodiment is provided with an exciter coil smaller than the conventional one, so that no excessive voltage is generated even when the engine reaches a high rotation state. At the ranking rotation speed Nc, the generated voltage Vgene falls below the required ignition voltage Vmin.

However, in this embodiment, since the power supply line of the battery is connected in parallel with the power supply line of the generator via the rectifier circuit 41, the power supply line of the igniter power supply 44 (point A in FIG. 1) , The higher voltage of the generated voltage Vgene and the battery voltage Vbatt is supplied. Therefore, during cranking, the generated voltage Vge
When ne falls below the battery voltage Vbatt, the igniter power supply 4
The battery voltage Vbatt is applied to the power supply line 4 via the diode D2. Therefore, a voltage higher than the battery voltage Vbatt is always applied to the power supply line of the igniter power supply 44.

On the other hand, when the engine is started and the engine speed Ne increases, the output voltage Vgene of the rectifier circuit 41 increases in response. When the output voltage Vgene of the rectifier circuit 41 exceeds the battery voltage Vbatt, the generated voltage gene is applied to the power supply line of the igniter power supply 44 via the diode D1. Therefore, as the engine speed increases, the igniter power supply 44
Therefore, the on-time of the igniter 43 can be shortened as the engine speed increases.

As described above, according to the present embodiment, the battery voltage batt is supplied to the power supply line of the igniter power supply 44 during the cranking period when the engine speed is low, and the power generation voltage Vgene is supplied after the engine is started. Therefore, the igniter power supply 44 can be used without increasing the size of the exciter coil.
A predetermined drive voltage can be supplied regardless of the engine speed. Therefore, as shown in FIG. 3, the ON time of the ignition coil can be shortened even in the cranking period when the engine speed is low, and the time for the CPU 46 to calculate the ignition timing and the like can be sufficiently ensured. And the power generation efficiency is improved.

Next, a drive control method of the starter motor 8 in the present embodiment will be described. In the present embodiment, starter control for reducing the power consumption of the starter motor 8 is performed at the beginning of cranking.

The driver 45 of the controller 4 has a power F
Including the ET 45a, the CPU 46 variably controls the power consumption of the starter motor 8 by PWM controlling the gate voltage of the power FET 45a. That is, the CPU 46 is configured as shown in FIG.
As shown in the figure, the duty ratio of the pulse signal applied to the gate of the power FET 45a is changed from 40% to 10% for a predetermined period (1 second in this embodiment) after the start of cranking.
Gradually increase to 0%.

FIGS. 5 and 6 are diagrams showing a change in the starter current Im and a change in the power supply line voltage (point B in FIG. 1) of the CPU 46 by the above-described starter control in comparison with the prior art.

According to the present embodiment, since the duty ratio of the pulse signal applied to the gate of the power FET 45a becomes small at the beginning of cranking, it is possible to suppress the peak of the starter current Im as shown in FIG. it can. Therefore, as shown in FIG. 6, the drive voltage of the CPU 46 at the beginning of cranking can be maintained at a reset voltage or higher.

Next, a burnout prevention system for the starter motor 8 according to the present embodiment will be described. Driver 45
The source / drain voltage VSD of the power FET 45a and the starter current Im have a unique relationship as shown in FIG. 7, and the source / drain voltage VSD can represent the starter current Im.

Therefore, in this embodiment, the power FET 45
a, the CPU 46 constantly monitors the source / drain voltage VSD, and when the voltage VSD reaches an overcurrent level, the power FET
45a is shut off to stop driving the starter motor 8.

[0027]

(1) According to the present invention, the driving voltage supplied from the igniter of the controller to the primary side of the ignition coil does not decrease even if the power consumption of the battery increases when the starter motor is driven. Therefore, the ON time of the igniter can be shortened even during the cranking period by the starter motor. Therefore, it is possible to ensure a sufficient time for the CPU to calculate the ignition timing and the like, and to accurately calculate the time, thereby providing an engine power generation system with high power generation efficiency and its controller.

(2) According to the present invention, during the cranking period, the drive current of the starter motor is reduced to reduce the power consumption of the battery and to suppress the power supply voltage drop in the controller. The drive voltage can always be maintained at the reset voltage or higher.

[Brief description of the drawings]

FIG. 1 is a block diagram of an engine power generation system according to an embodiment of the present invention.

FIG. 2 is a diagram showing a relationship between an engine speed and a power supply voltage of an igniter according to the present invention in comparison with a related art.

FIG. 3 is a diagram showing a relationship between an engine speed and an igniter on-time according to the present invention in comparison with the related art.

FIG. 4 is a diagram for explaining starter control according to the present invention.

FIG. 5 is a diagram comparing the change over time of the starter current according to the present invention with that of the prior art.

FIG. 6 is a diagram showing a relationship between an engine speed and a power supply voltage of a CPU according to the present invention in comparison with a related art.

FIG. 7 shows a power F for switching the starter current Im.
FIG. 5 is a diagram showing a relationship between a source / drain voltage VSD of ET and a starter current Im.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Engine, 2 ... Generator, 3 ... Transformer, 4 ... Controller, 5 ... Battery, 6 ... Ignition coil, 7 ... Ignition plug, 8 ... Starter motor, 48 ... Temperature sensor, 49 ... Pulser coil

Continued on the front page (72) Inventor Koichi Asai 1-4-1 Chuo, Wako-shi, Saitama F-term in Honda R & D Co., Ltd. (Reference) 3G019 AC01 BA07 DA04 DC03 EB01 EB09 GA01 GA11 3G093 AA16 CA01 DA01 DA04 DB23 EA12 EB00 EC01 FA14 FB05 5G060 AA03 AA04 AA08 CA08 DA01

Claims (8)

[Claims] 1. A generator driven by an engine, a starter motor for cranking the engine, and an electric load including the starter motor controlled by a driving voltage depending on electric power supplied from the generator and a battery. An engine power generation system, comprising: a controller; and the controller includes a voltage drop suppression unit that suppresses a drive voltage drop when the starter motor is driven. 2. The controller according to claim 1, wherein the controller includes an igniter for supplying ignition energy to an ignition coil of the engine, and the voltage drop suppressing unit is configured to connect a power supply line of the generator and a power supply line of a battery in parallel. The engine power generation system according to claim 1, wherein a voltage is supplied to a power supply line of the igniter. 3. The engine power generation system according to claim 1, wherein the voltage drop suppressing unit variably controls a duty ratio of a drive voltage supplied to the starter motor. 4. The method according to claim 1, wherein the voltage drop suppressing unit sets the duty ratio of the drive voltage supplied to the starter motor to a small value when the starter motor is started, and thereafter gradually increases the duty ratio with time. 4. The engine power generation system according to 3. 5. A controller for an engine power generation system that supplies a drive voltage dependent on electric power supplied from a generator and a battery to an electric load including a starter motor, wherein a voltage drop that suppresses a drive voltage drop when the starter motor is driven is provided. A controller for an engine power generation system, characterized by including a suppression means. 6. The controller includes an igniter for supplying ignition energy to an ignition coil of an engine, and the voltage drop suppressing unit includes a drive voltage obtained by connecting a power supply line of a generator and a power supply line of a battery in parallel. Is supplied to a power supply line of the igniter. 7. The controller according to claim 5, wherein the voltage drop suppressing unit variably controls a duty ratio of a drive voltage supplied to the starter motor. 8. The method according to claim 1, wherein said voltage drop suppressing means sets a duty ratio of a drive voltage supplied to said starter motor to a small value when the starter motor is started, and thereafter gradually increases as time elapses. 8. The controller of the engine power generation system according to 7.