JP5594174B2 - Power supply device for internal combustion engine - Google Patents

Description

  The present invention relates to a power supply device for an internal combustion engine that is suitable for use in a fuel injection type small outboard motor that has no electric switch and that has an electric start device.

  Vehicles such as automobiles and motorcycles are provided with a main switch. By turning off the main switch after the engine is stopped, dark current from the battery to the engine control unit (hereinafter referred to as ECU) can be cut off. it can. For example, Patent Document 1 discloses a vehicle power supply device including a main switch. Patent Document 1 includes a battery relay and a starter relay, and opens the battery relay at the time of kick start to disconnect the battery from the engine load, and switches the starter relay to disconnect the battery from the generator (the generator is connected to the engine load). The structure which connects to (1) is disclosed. Also, a configuration is disclosed in which, when starting the starter motor, the battery relay is closed to connect the battery to the engine load, and the starter relay is switched to connect the battery to the generator (disconnect the generator from the engine load). . Here too, as with a general vehicle, the battery is disconnected from the ECU by turning off the main switch.

  On the other hand, some small outboard motors do not have a main switch. Some small outboard motors that do not include a main switch are equipped with an electric start device that includes a battery and a starter motor. In this case, the engine is started by operating either a starter switch or a recoil starter. Since the engine stop switch is provided, the engine can be stopped.

  Here, in the case of the carburetor type, since the fuel is supplied from the fuel tank of the hull to the carburetor of the outboard motor by manually operating the squeeze pump, an electric fuel pump is unnecessary. Further, since it does not have an injector, the engine load only includes an ignition control device such as a CDI unit, and a battery is not used as a power source. However, in the case of the fuel injection type, a battery is required as a power source of the ECU for driving control of the fuel pump and the injector. Therefore, when the main switch is not provided, a dark current flows from the battery to the ECU when the engine is stopped, and the battery may run out.

JP 2002-98032 A

  Even in a fuel injection type small outboard motor that does not have a main switch and is equipped with an electric start device, it is necessary to cut off the dark current from the battery to the ECU when the engine is stopped. In this case, as shown in FIG. 8, the electrical connection between the battery and the ECU is completely disconnected, and the starter circuit and the charge coil for charging the battery are connected to the battery, while the charge coil is connected to the ECU. A configuration in which electrically independent power supply coils (hereinafter referred to as ECU charge coils) are connected is conceivable. The exciter coil is a coil that supplies electricity for engine ignition.

  However, the configuration in which the charge coil and the ECU charge coil (which also supplies power to the engine load such as a fuel pump and an injector) are separated in this way is not suitable for a small outboard motor because the generator becomes large. . The charging coil for charging the battery is required to have a high characteristic in the generated current. However, as shown in FIG. 9, if priority is given to increasing the maximum value of the generated current, the rise of the generated current is delayed. For this reason, the cranking rotational speed at the time of electric start is low, and electric power necessary for starting cannot be secured. The power generation current in the low engine speed range becomes small, and no power is generated in the extremely low engine speed range. Even with such charge coil characteristics, if power is supplied from the battery to the ECU when the engine is started, current shortage before the rise of the generated current can be compensated. If the electrical connection is cut off, power supply from the battery to the ECU becomes impossible. Therefore, an ECU charge coil having different characteristics from the charge coil is required separately. Since the ECU drives and controls engine loads such as a fuel pump and an injector, an ECU charge coil having a characteristic capable of generating predetermined power even in a low engine speed range is required. In order to increase the amount of power generation in the low engine speed range, it is necessary to increase the number of turns of the coil. Therefore, the ECU charge coil becomes large and is not suitable for a small outboard motor.

  The present invention has been made in view of the above points, and it is an object of the present invention to cut off dark current from the battery to the engine control unit while electrically connecting the battery and the ECU.

The power supply device for an internal combustion engine of the present invention includes an alternator, a rectifier connected to the alternator, a battery connected to the alternator via the rectifier, and a connection between the alternator and the battery in the rectifier. An internal combustion engine power supply device comprising an engine control unit connected in between, and an engine load connected to the engine control unit , wherein the rectifier includes a control circuit driven by the generated power of the alternator, The engine control unit is arranged in the rectifier or between the connection of the rectifier and the engine control unit, and when the control circuit detects the power generation of the alternator, is controlled by the control circuit and from the battery to the engine control unit. to allow the supply of power to the, of the internal combustion engine Rolling a first cutoff means when stopping to cut off the power supply to the engine control unit from the battery, the voltage of the battery exceeds a threshold value, the power is controlled by the control circuit to the battery from the alternator And a second shut-off means for allowing supply .
In this case, the first shut-off means is a first FET disposed between the alternator and the battery in the rectifier between the connection of the engine control unit and the battery side. It may be. The first FET includes a diode arranged such that a source is connected to the alternator side and a drain is connected to the battery side, and a current flows only from the source side to the drain side.
The first blocking means may be a relay disposed between the connection of the rectifier and the engine control unit.
The second shut-off means may be a second FET disposed between the first shut-off means in the rectifier and the battery . The second FET includes a diode that is arranged in such a manner that a source is connected to the battery side and a drain is connected to the alternator side, and a current flows only from the source side to the drain side.

  According to the present invention, since the shut-off means for shutting off the power supply from the battery to the engine control unit when the operation of the internal combustion engine is stopped is provided, the battery and the ECU are electrically connected, while the darkness from the battery to the engine control unit is established. The current can be cut off and the battery can be prevented from running out.

1 is a circuit diagram illustrating a configuration of a power supply device for an internal combustion engine according to a first embodiment. FIG. It is a side view which shows the example of the outboard motor carrying the electric power supply apparatus of the internal combustion engine of this invention. FIG. 3 is a plan view showing around an engine of an outboard motor. FIG. 3 is a right side view showing the periphery of the engine of the outboard motor. It is a flowchart which shows the operation | movement at the time of the electric start of the electric power supply apparatus of the internal combustion engine which concerns on 1st Embodiment. 4 is a flowchart showing an operation at the time of manual start of the power supply device for the internal combustion engine according to the first embodiment. It is a circuit diagram which shows the structure of the electric power supply apparatus of the internal combustion engine which concerns on 2nd Embodiment. It is a figure which shows the structure which connects a charge coil to a battery and connects ECU charge coil electrically independent from the charge coil to ECU. It is a characteristic view which shows the relationship between the engine speed in a charge coil and ECU charge coil, and generated electric current.

Preferred embodiments of the present invention will be described below with reference to the accompanying drawings.
(First embodiment)
First, an example of an outboard motor equipped with the power supply device for an internal combustion engine of the present invention will be described with reference to FIG. As necessary, the front of the outboard motor is indicated by an arrow Fr and the rear is indicated by an arrow Rr. The front of the outboard motor is a direction in which the hull advances forward in a state where the outboard motor is attached to the hull.

  As shown in FIG. 2, the outboard motor is attached in an upright state via a clamp bracket 101 to a transom board of a hull (not shown). An engine 103 which is an internal combustion engine and an oil pan 104 below the engine cover 102 are accommodated in the engine cover 102 above the outboard motor. The engine 103 may be, for example, a water-cooled four-cycle multi-cylinder engine, and is a so-called vertical type engine in which a crankshaft is disposed substantially vertically.

  A drive shaft housing 105 is installed below the engine cover 102. A drive shaft 106 is disposed substantially vertically in the drive shaft housing 105, and its upper end is connected to the lower end of the crankshaft. The drive shaft 106 extends downward in the drive shaft housing 105 and is linked to a bevel gear 108 and a propeller shaft 109 in a gear case 107 provided at the lower portion of the drive shaft housing 105. Thereby, the rotation of the drive shaft 106 is transmitted to the propeller shaft 109 to drive the propeller 110.

  A steering handle 111 extends forward from the front of the engine 103. When the boat operator turns the steering handle 111 in the horizontal direction, the steering angle of the outboard motor is changed, and the traveling direction of the hull can be changed. A throttle grip 112 for adjusting engine output is provided at the tip of the steering handle 111.

  The clamp bracket 101 rotatably supports the outboard motor about the tilt shaft 113 as a rotation center. Therefore, in a state where the clamp bracket 101 is fixed to the transom board, it is possible to perform a so-called tilt-up operation in which the outboard motor is rotated in the direction of the arrow with the tilt shaft 113 as the center of rotation to be lifted from the water.

  FIG. 1 is a circuit diagram showing a configuration of a power supply device for an internal combustion engine according to the first embodiment. The alternator 1 is connected to the positive terminal of the battery 3 via the regulated rectifier 2. The regulated rectifier 2 feeds the battery 3 with full-wave rectification of the three-phase alternating current generated by the alternator 1. The regulated rectifier 2 includes a control circuit 2a that is driven by the generated power of the alternator 1. When the voltage of the battery 3 is measured and becomes a reference voltage (generally 14.5 ± 0.5V) or more, the thyristor is turned on. Turn on to limit power supply to the battery 3.

  A DC power terminal 4a of the ECU 4 is connected to a branch point A between the alternator 1 and the battery 3 in the regulated rectifier 2. An engine load 5 such as a DC-CDI (Capacitor Discharge Ignition), a fuel pump, an injector, an ISC (Idle Speed Control) valve, and various sensors is connected to the power output terminal 4b of the ECU 4. In this embodiment, since DC-CDI driven by a direct current is used as the ignition control device, an exciter coil is unnecessary. Further, a notification device 6 such as an indicator lamp or a buzzer is connected to the ECU 4.

  A starter motor 7 and a starter circuit 8 for switching on / off of power supply from the battery 3 to the starter motor 7 are connected to the battery 3 in parallel. The starter circuit 8 is a series connection of a start switch 9, a neutral switch 10 for detecting the neutral state of the transmission, and a starter relay 11 in this order from the positive terminal side of the battery 3. The start switch 9 is normally open and is closed when there is an ON operation by the operator. Neutral switch 10 is normally open and closes in the neutral state of the transmission. The starter relay 11 is normally open and is closed by energizing the coil.

  Further, a marine load 12 such as a light or a fish finder is connected in parallel to the battery 3.

  Here, between the connection between the alternator 1 in the regulated rectifier 2 and the battery 3 and closer to the battery 3 than the branch point A, that is, between the connection between the battery 3 and the DC power supply terminal 4 a of the ECU 4, FET 13 is arranged. The first FET 13 is arranged in such a manner that the source is connected to the alternator 1 side and the drain is connected to the battery 3 side. The first FET 13 is normally open and is controlled by the control circuit 2 a of the regulated rectifier 2. More specifically, the control circuit 2a is connected to the alternator 1, and when power generation of the alternator 1 is detected, the control circuit 2a controls the first FET 13 to allow a current to flow between the drain and the source.

  The first FET 13 includes a parasitic diode 13a that allows current to flow only from the source side to the drain side.

  When the operation of the engine 103 is stopped, the first FET 13 is opened, and since the parasitic diode 13a is present, the power supply from the battery 3 to the ECU 4 is cut off.

  A second FET 14 is disposed between the alternator 1 in the regulated rectifier 2 and the battery 3 and closer to the battery 3 than the first FET 13. The second FET 14 is arranged in such a manner that the source is connected to the battery 3 side and the drain is connected to the alternator 1 side, that is, opposite to the first FET 13. The second FET 14 is normally open and is controlled by the control circuit 2 a of the regulated rectifier 2. More specifically, the control circuit 2a controls the second FET 14 when the voltage of the battery 3 exceeds a threshold value (for example, about 13.5 ± 0.5V lower than the reference voltage 14.5 ± 0.5V). , Allowing a current to flow between the drain and the source.

  The second FET 14 includes a parasitic diode 14a that allows current to flow only from the source side to the drain side.

  FIG. 3 is a plan view showing the periphery of the engine 103 of the outboard motor, and FIG. 4 is a right side view. With reference to these FIG. 3 and FIG. 4, the example of arrangement | positioning structure of the main components shown in FIG. 1 is demonstrated. As shown in FIG. 4, a flywheel magnet 117 is fixed to the upper end side of the crankshaft 116. A charge coil 118 is fixed around the crankshaft 116 in the upper part of the engine 103 so as to be enclosed in a flywheel magnet 117. The alternator 1 includes the flywheel magnet 117 and the charge coil 118, and the charge coil AC is generated by the rotation of the flywheel magnet 117. Moreover, although illustration is abbreviate | omitted, the flywheel magnet cover which contains the flywheel magnet 117 is attached, and the recoil starter is attached to the flywheel magnet cover. The recoil starter rotates the flywheel magnet 117 when the starter grip 119 (see FIG. 1) is pulled, and starts the engine 103 by rotating the crankshaft 116.

  A starter motor 7 is mounted on the front portion of the engine 103 via a bracket 120. A battery cable 121 extends from the front of the engine 103 on the lower side of the starter motor 7 and is connected to the battery 3 installed on the hull side.

  The ECU 4 is held by the holder 122 on the right side of the engine 103. Further, a regulated rectifier 2 is disposed behind the ECU 4.

  Below, operation | movement of the electric power supply apparatus of the internal combustion engine which concerns on 1st Embodiment is demonstrated. First, the operation at the time of electric start will be described with reference to the flowchart of FIG. When the transmission is in a neutral state, that is, when the neutral switch 10 is closed (step S1), when the operator turns on the start switch 9, the start switch 9 is closed (step S2). . Therefore, the coil of the starter relay 11 is energized from the battery 3 via the start switch 9 and the neutral switch 10. As a result, the movable contact of the starter relay 11 moves to electrically connect the two fixed contacts (step S3), and the starter motor 7 is driven by the power supply from the battery 3 (step S4).

  When the starter motor 7 is driven, the alternator 1 generates power, so that the generated power of the alternator 1 is supplied to the ECU 4 via the branch point A. Further, since the alternator 1 generates power, the control circuit 2a of the regulated rectifier 2 controls the first FET 13 to allow a current to flow between the drain and source (step S5). Thereby, electric power is also supplied from the battery 3 to the ECU 4 via the parasitic diode 14a of the second FET 14 and the first FET 13 (step S6). The ECU 4 receives power supply from the alternator 1 and the battery 3, applies a power output to the engine load 5, and starts the engine 103 (step S7). Generally, a small low-power motor is used for a starter motor mounted on a small outboard motor. Therefore, the cranking speed at the electric start is about 400 rpm, which is lower than the cranking speed at the manual start. . Therefore, the power generated by the alternator 1 at the time of cranking may not be able to secure the power necessary for starting the engine 103. Therefore, at the time of electric start, electric power is also supplied from the battery 3 to the ECU 4 to start the engine 103.

  After that, when the boat operator turns off the start switch 9, that is, releases the on operation (step S8), the start switch 9 is opened and the starter motor 7 is stopped (step S9).

  When the start of the engine 103 is completed as described above and the ECU 4 is in a normal operation state, the ECU 4 receives power supply from the alternator 1 and applies a power output to the engine load 5.

  During normal operation, the second FET 14 is controlled according to the voltage of the battery 3 by the control circuit 2 a of the regulated rectifier 2. That is, if the voltage of the battery 3 exceeds a threshold value (for example, about 13.5 ± 0.5 V lower than the reference voltage 14.5 ± 0.5 V) (step S10), the control circuit 2a determines the second FET 14 To allow a current to flow between the drain and the source (step S11). Thereby, the electric power generated by the alternator 1 is supplied to the battery 3 to charge the battery 3 (step S12).

  However, even during normal operation, when the voltage of the battery 3 becomes equal to or lower than the threshold value (step S10), the control circuit 2a controls the second FET 14 so that no current flows between the drain and the source (step S13). ), The battery 3 is not charged. This is for avoiding a decrease in the amount of power output to the engine load 5 as a result of the generated power of the alternator 1 being used to charge the battery 3 when the voltage of the battery 3 is extremely low. . Even when current is prevented from flowing between the drain and source in the second FET 14, the battery 3 can supply power to the ECU 4 via the parasitic diode 14 a of the second FET 14 and the first FET 13. It is. When the voltage of the battery 3 is low and the battery 3 is not charged in this way, the indicator lamp is turned on, flashed, or an alarm sound such as a buzzer sound is generated to notify the operator of the fact. Or output.

  Note that the processing in steps S10 to S13 is periodically performed, for example, during normal operation. When the ship operator turns on the stop switch 15 during normal operation, the ECU 4 stops ignition and fuel injection, and the operation of the engine 103 stops.

  Next, the operation at the time of manual start will be described with reference to the flowchart of FIG. At the time of manual start, since the operator does not turn on the start switch 9, the start switch 9 is opened. Further, the manual start cannot be performed unless the transmission is in the neutral state, and the neutral switch 10 is closed. When the crankshaft is rotated by a recoil starter or the like by the manual start operation of the boat operator (step S21), the generated power of the alternator 1 is supplied to the ECU 4 via the branch point A. Further, since the alternator 1 generates power, the control circuit 2a of the regulated rectifier 2 controls the second FET 14 to allow a current to flow between the drain and the source. Thereby, electric power is also supplied from the battery 3 to the ECU 4 via the parasitic diode 14a of the second FET 14 and the first FET 13 (step S22). The ECU 4 receives power supply from the alternator 1 and the battery 3, applies a power output to the engine load 5, and starts the engine 103 (step S23). Thus, since electric power is also supplied from the battery 3 at the time of a manual start, the engine 103 can be reliably started even if the tensile force is insufficient and the generated power of the alternator 1 is insufficient.

  When the start of the engine 103 is completed as described above and the ECU 4 is in a normal operation state, the ECU 4 receives power supply from the alternator 1 and applies a power output to the engine load 5. Although omitted in FIG. 6, in this case as well, as described in steps S <b> 10 to S <b> 13 of FIG. 5, the control circuit 2 a controls the second FET 14 if the voltage of the battery 3 exceeds the threshold value, When the battery 3 is charged by the generated power of the alternator 1 and the voltage of the battery 3 becomes equal to or lower than the threshold value, the second FET 14 is controlled and the battery 3 is not charged.

  As described above, the fuel injection type small outboard motor without the main switch and equipped with the electric start device includes the first FET 13 that cuts off the power supply from the battery 3 to the ECU 4 when the operation of the engine 103 is stopped. Therefore, the dark current from the battery 3 to the ECU 4 can be cut off, and the battery can be prevented from running out.

  Further, since the electrical connection between the battery 3 and the ECU 4 is not completely disconnected, but the battery 3 and the ECU 4 are electrically connected, it is not necessary to separately provide an ECU charge coil, and the large size of the outboard motor Can be avoided.

  Further, since the second FET 14 for controlling the charging of the battery 3 is provided in the regulated rectifier 2 and is controlled not by the ECU 4 but by the control circuit 2a of the regulated rectifier 2, the ECU 4 There is no need to perform voltage detection, and the input / output terminal of the ECU 4 can be earned and used for other purposes.

(Second Embodiment)
FIG. 7 is a circuit diagram illustrating a configuration of a power supply device for an internal combustion engine according to the second embodiment. In addition, the same code | symbol is attached | subjected to the same component as 1st Embodiment, and the detailed description is abbreviate | omitted. In the second embodiment, a relay 16 is provided between the regulated rectifier 2 and the ECU 4 in place of the first FET 13. The relay 16 is normally open and is controlled by the control circuit 2 a of the regulated rectifier 2. That is, since the relay 16 is opened when the operation of the engine 103 is stopped, the power supply from the battery 3 to the ECU 4 is interrupted. The control circuit 2a is connected to the alternator 1, and when power generation of the alternator 1 is detected, the coil of the relay 16 is energized to allow power supply from the alternator 1 and the battery 3 to the ECU 4.

  The operations at the start and normal operation of the engine 103 are the same as those in the first embodiment, and a detailed description thereof is omitted here.

  Also in the second embodiment, since there is no main switch and the fuel injection-type small outboard motor equipped with the electric start device is provided with the relay 16 for cutting off the power supply from the battery 3 to the ECU 4, the battery 3 to the ECU 4 is provided. The dark current can be cut off and the battery can be prevented from running out. In the second embodiment, since a relay cheaper than the FET is used, the cost can be reduced.

  As mentioned above, although this invention was demonstrated with various embodiment, this invention is not limited only to these embodiment, A change etc. are possible within the scope of the present invention.

  1: alternator, 2: regulated rectifier, 3: battery, 4: ECU, 5: engine load, 6: notification device, 7: starter motor, 8: starter circuit, 9: start switch, 10: neutral switch, 11 : Starter relay, 12: Ship load, 13: First FET, 13a: Parasitic diode, 14: Second FET, 14a: Parasitic diode, 15: Stop switch, 16: Relay

Claims (6)

Alternator,
A rectifier connected to the alternator;
A battery connected to the alternator via the rectifier;
An engine control unit connected between the alternator and the battery in the rectifier;
An internal combustion engine power supply device comprising an engine load connected to the engine control unit,
The rectifier includes a control circuit that is driven by the generated power of the alternator,
The engine control unit is arranged in the rectifier or between the connection of the rectifier and the engine control unit, and when the control circuit detects the power generation of the alternator, is controlled by the control circuit and from the battery to the engine control unit. a first cutoff means to permit the power supply, during operation of the internal combustion engine is stopped to cut off the power supply to the engine control unit from said battery to,
An internal combustion engine power supply apparatus comprising: a second shut-off unit that is controlled by the control circuit to allow power supply from the alternator to the battery when the voltage of the battery exceeds a threshold value . The first shut-off means is a first FET disposed between the alternator in the rectifier and the battery and located closer to the battery than a position where the engine control unit is connected. The power supply device for an internal combustion engine according to claim 1 , wherein the power supply device is an internal combustion engine. The first FET is a source to the alternator side, are arranged in the form of a drain connected to the battery side, claim 2, characterized in that from the source side comprising a diode passing a current only in the drain side A power supply device for an internal combustion engine according to claim 1. 2. The power supply device for an internal combustion engine according to claim 1 , wherein the first shut-off unit is a relay disposed between the connection of the rectifier and the engine control unit. The said 2nd interruption | blocking means is 2nd FET arrange | positioned between the connection of the said 1st interruption | blocking means in the said rectifier , and the said battery, The any one of Claim 1 thru | or 4 characterized by the above-mentioned. The power supply device for an internal combustion engine according to the item. Said second FET is a source to the battery side, is arranged in the form of a drain connected to the alternator side, claim 5, characterized in that from the source side comprising a diode passing a current only in the drain side A power supply device for an internal combustion engine according to claim 1.

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