JP4799641B2 - Engine starter - Google Patents

Description

  The present invention relates to an engine starter that starts an engine with a starter motor.

  When starting the engine, energize the coil of the starter switch, close the internal contact of the starter switch to supply power from the vehicle power supply to the starter motor, generate rotational torque in the starter motor, and engage the meshed pinion gear. The torque of the starter motor is transmitted to the engine crankshaft via the ring gear to start the engine. At this time, when the starter switch is closed, the starter motor is still in a stationary state and no back electromotive force is generated. Therefore, an inrush current of several hundred to several hundreds of amps flows due to an extremely small starter internal resistance. Due to this current, the terminal voltage of the vehicular power supply decreases due to the internal specific resistance, and a voltage drop occurs.

  For this reason, in starting the engine, there has been a problem of causing a momentary interruption when using other electric devices of the vehicle such as a stereo, a navigation system, and an air conditioner due to a voltage drop of the power source for the vehicle due to the current at the start of the starter motor. This momentary interruption is not particularly a problem when starting an ordinary engine, but in vehicles equipped with an idling stop function, an instantaneous interruption occurs when restarting after idling stop. The situation was uncomfortable. Therefore, in order to avoid this instantaneous interruption, measures are taken to prevent a decrease in the voltage of the vehicle power supply by providing a backup power supply or mounting a boosting DC / DC converter.

  Furthermore, in the conventional engine starter disclosed in Patent Document 1, a motor having a series winding coil and a shunt coil, a starting resistor connected in series with an armature of the motor, and a field current of the shunt coil A control element for controlling the motor is provided, and the motor is energized via a starting resistor when the engine is started. As a result, the starting current (rush current) to the motor is reduced, and the voltage drop of the battery is suppressed to 2V or less. In addition, since a high torque type motor is employed, even if the starting current of the motor is small, it is possible to secure the torque necessary for getting over the first top dead center. Furthermore, after overcoming the first top dead center, the cranking speed necessary for starting the engine can be ensured by controlling the field current of the shunt coil to obtain high rotation characteristics. As a result, a voltage drop exceeding 2 V is not generated when the engine is started, and the engine can be started without instantaneous interruption.

  Moreover, in the conventional internal combustion engine starter disclosed in Patent Document 2, the starter includes a DC motor having a multi-turn motor, a capacitor connected in series with a shunt coil, and a first energization direction and a capacitor for charging the capacitor. An H-type control device that switches between the second energization direction for discharging from the coil to the shunt coil. The energization direction is switched to the first energization direction when the DC motor is started, and the energization direction is switched from the first energization direction to the second energization direction by the H-type control device when the DC motor is started. Thereby, the voltage drop of the main power supply accompanying the start of the DC motor can be compensated, and the required torque of the starter can be ensured. As a result, the main power supply capacity is not increased, the main power supply voltage is not boosted by the booster, and the voltage drop of the main power supply accompanying the start of the DC motor is compensated for, thus realizing a starter without instantaneous interruption. is doing.

JP 2004-308645 A JP 2005-105861 A

  However, the engine starting device disclosed in Patent Document 1 requires a switch control device that connects a starting resistor to suppress a voltage drop at the start and short-circuits the starting resistor, and the voltage drop at the start is 2 V or less. Therefore, there is a problem that the control device and the program need to be created for this control, and the engine start circuit becomes complicated.

  In addition, in the internal combustion engine starting device disclosed in Patent Document 2, in order to suppress a voltage drop at the start, a capacitor is charged in advance and the charging power is discharged at the start to compensate for the voltage drop of the main power supply. Therefore, it is necessary to add a large-capacity capacitor that can store the necessary power as an auxiliary power source, and an H-type control device that is a means for switching the energization direction in order to switch the charging / discharging of the capacitor by the control element. There was a problem of complicated control. Further, in an operating environment in which it is necessary to frequently start and stop, there is a problem that it is necessary to discharge without being fully charged, and there is a possibility that the performance may not be sufficiently exhibited.

  The present invention has been made to solve the above-described problems, has a simple circuit configuration, does not require a control device or an auxiliary power supply, and does not cause an instantaneous interruption of an in-vehicle electric device. An object of the present invention is to provide an engine starter having excellent stability and reliability for starting.

  In order to solve the above-described problems, an engine starter according to the present invention includes a resistor, a resistor, and a resistor in an engine starter that supplies power from a power source to drive a starter motor by operating a starter circuit including a starter switch. A short circuit composed of a short circuit switch connected in parallel with the body and closed by the drive coil is inserted between the power source and the starter motor, and one end of the drive coil of the short circuit switch is connected to the starter switch and the short circuit switch. The other end of the drive coil is grounded.

  According to the present invention, when the engine is started, first, the resistor installed between the power source and the starter motor is energized, starting at a low current, and after a predetermined delay time, automatically with a short-circuit switch, By short-circuiting this resistor, the voltage drop at the start of the start is suppressed, and a remarkable effect is achieved such that the engine can be started without causing an instantaneous interruption to the on-vehicle electric device.

It is a figure which shows the circuit structure of the engine starting apparatus in embodiment. It is a figure which shows the other circuit structure of the engine starting apparatus in embodiment. It is a figure which shows the further another circuit structure of the engine starting apparatus in embodiment. It is a figure which shows the circuit structure of a normal engine starting device.

  Hereinafter, an engine starter according to an embodiment of the present invention will be described with reference to FIGS.

  In FIG. 1, an engine starter 1 includes a starter motor 2 that starts an engine (not shown), a battery 3 that is a power source 3 that supplies power to the starter motor 2, and a battery 3 that starts the starter motor 2. The start switch 4 connected, the starter switch 5a connected in series between the starter motor 2 and the battery 3, and the short-circuit switch 6a and the short-circuit switch 6a are connected in parallel with the short-circuit switch 6a. The resistor 7 is connected between the terminal A and the ground terminal C, and the drive coil 6b of the short-circuit switch 6a that closes the short-circuit switch 6a (the circuit constituted by the short-circuit switch 6a and the drive coil 6b is a short circuit) The starter switch 4 and the terminal D on the starter switch 5a side of the short-circuit switch 6a. Is connected between the starter switch 4 and the ground terminal C, and is held between the starter switch 5a and the holding coil 5c (starter switch 5a and its drive coil 5b). And a circuit constituted by the holding coil 5c is referred to as a starting circuit).

  FIG. 4 illustrates a normal engine starter that does not take measures to suppress voltage drop during engine start. In response to the engine start request, the start switch 4 is closed, and the starter switch 5a is closed by the drive coil 5b of the starter switch 5a from the battery 3 via the start switch 4, the current is supplied to the starter motor 2, and the starter motor 2 is supplied. Starts rotating. A large current flows as the starter motor 2 is started, so that the voltage of the battery 3 is lowered, and there is a possibility that an electrical device such as a navigation system may be momentarily interrupted. In particular, in a vehicle or the like equipped with an idling stop function, an instantaneous interruption occurs when restarting after idling stop.

Next, the operation of the engine starter according to the embodiment will be described with reference to FIG.
First, as a first step of engine start, the start switch 4 is closed in response to an engine start request, and the drive coil 5b and the holding coil 5c of the starter switch 5a are energized from the battery 3 via the start switch 4, and further the resistor 7, the current A is supplied to the starter motor 2, and the starter motor 2 starts to rotate. Subsequently, as a second step, when the drive coil 5b and the holding coil 5c are energized, the plunger of the starter switch 5a is driven and the starter switch 5a is closed. Here, the holding coil 5c is connected to the start switch 4, the battery 3, and the ground terminal C, and the starter switch 5a is kept closed when energized. As a result, rotational torque is generated in the starter motor 2 and the meshed pinion gear starts to move toward the ring gear provided on the crankshaft of the engine. When the starter switch 5a is closed, the current Ia flowing through the drive coil 5b is almost extinguished and becomes the current Ib flowing through the starter switch 5a and the resistor 7 closed from the battery 3. Here, the holding coil 5c is connected to the start switch 4, the battery 3, and the ground terminal C, and the starter switch 5a is kept closed when energized. Further, as a third step, the short-circuit switch 6a is closed by energizing the drive coil 6b of the short-circuit switch 6a connected in parallel to the resistor 7 by the current Ib following the current Ia. 7, the current Ib flowing through 7 is almost extinguished, and a normal starter current is supplied to the starter motor 2, and the rotational force of the starter motor 2 is transmitted to the engine crankshaft to start the engine.

  The delay time is determined by the time from when the starter switch 5a is closed and the current flows to the starter motor 2 through the resistor 7 until the starter motor 2 starts to rotate until a predetermined number of rotations is reached. The predetermined number of revolutions depends on how much voltage drop is allowed. That is, the delay time may be increased if the target voltage drop amount of the power supply may be set large, or the delay time may be reduced if the voltage drop amount may be set small. The allowable power supply voltage drop must be within a range that does not cause an on-vehicle electrical device to be momentarily interrupted. The delay time and the resistance value of the resistor are set by the internal resistance of the battery, the starter motor specification (internal resistance), the wiring resistance and the target engine.

  In this case, the ignition key entered by the driver at the first start and the parallel circuit of the switch controlled by the control unit (ECU) at the restart when the engine start request after the idling stop is generated are simplified. It is represented by a start switch.

  According to the configuration of such an embodiment, in the first step, the drive coil 5b, the resistor 7 and each wiring resistance exist on the circuit, and in the second step, the resistor 7 and each wiring resistance, In the step, each wiring resistance exists, and the electrical resistance decreases in three stages. Furthermore, since the starter motor 2 starts rotating by the current Ia and the current Ib before the third step, the counter electromotive voltage of the starter is increased and the current is suppressed, so that particularly expensive control devices, DC / DC converters, etc. Even if it is not used, the voltage drop of the power source can be suppressed.

  As described above, in the engine starter according to the embodiment, when starting the starter motor, first, the resistor installed between the power source and the starter motor is energized, and after a predetermined delay time, automatically with a short-circuit switch. By short-circuiting the resistor, the initial current is reduced, the voltage drop is suppressed, and the engine can be started without instantaneously interrupting the on-vehicle electric device.

  In the circuit diagram of FIG. 1 showing the engine starter according to the embodiment of the present invention, the current of the drive coil 6b is supplied from the terminal A, whereby the short-circuit switch 6a is closed and the resistor 7 is short-circuited. 2, the current of the drive coil 6b of the short-circuit switch 6a may be supplied from the terminal B as shown in the circuit diagram of the engine starter in FIG. In this case, the voltage applied to the drive coil 6b is low immediately after the starter switch 5a starts operating, and the rotation of the starter motor 2 is increased, and the short-circuit switch 6a is activated after the voltage at the terminal B is increased by the induced voltage. Further, a delay in the operation time occurs in the closing of the short-circuit switch 6a, which facilitates the rotation of the starter motor 2 and is advantageous in suppressing the voltage drop of the power source.

  In the circuit diagram of the engine starter shown in FIG. 3, the starter circuit 5 including the starter switch 5a is installed on the starter motor 2 side, and the short circuit 6 for short-circuiting the resistor 7 is installed on the battery 3 side. As in the embodiment shown in FIG. 1, the same effect as that when the short circuit 6 is installed on the starter motor 2 side can be obtained. Furthermore, in this arrangement, the connection between the starter circuit 5 and the starter motor 2 is the same as that of the conventional device shown in FIG. 4, so that standardization of the production facility can be achieved and a short circuit can be retrofitted without disconnecting the conventional device. 6 can be connected.

  Moreover, in the figure, the same code | symbol shows the same or an equivalent part.

DESCRIPTION OF SYMBOLS 1 Engine starter 2 Starter motor 3 Battery 4 Start switch 5 Start circuit 5a Starter switch 5b Drive coil 6 Short circuit 6a Short switch 6b Drive coil 7 Resistor

Claims (1)

In an engine starter that drives a starter motor by supplying electric power from a power source by operating a starter circuit constituted by a starter switch,
A short circuit comprising a resistor and a short circuit switch connected in parallel with the resistor and closed by a drive coil , the starter switch and the short circuit switch are connected in series, and the power source and the An engine which is inserted between a starter motor, one end of a drive coil of the short-circuit switch is connected to the starter motor side of the starter switch, and the other end of the drive coil is grounded Starter.