JP3228000B2 - Engine starter - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an engine starting device for discharging an electric double layer capacitor to drive a starter and start an engine.

[0002]

2. Description of the Related Art In a vehicle such as a delivery vehicle which repeatedly starts and stops frequently, the number of starts is increased. Generally, the engine of a vehicle is started by instantaneously flowing a large current from a battery to a starter. Since the current from the battery is generated by a chemical reaction, frequent withdrawal of large instantaneous currents shortens the life of the battery.

[0003] Therefore, there is an engine starter in which a large-capacity capacitor (for example, an electric double layer capacitor) is provided in parallel with a battery, the capacitor is charged once from the battery, and is discharged from the capacitor to a starter at the time of starting. Proposed (eg, Japanese Patent Application No. 63-3298)
No. 64). Also, an engine starter has been proposed in which, when the voltage specification of the starter is higher than the battery voltage, the battery voltage is boosted to charge the capacitor (for example, Japanese Patent Application Laid-Open No. 2-259277).

FIG. 3 shows such a conventional engine starting device. 3, reference numeral 1 denotes a key switch unit, and 1-1.
Is a key switch, 1-2 is a switch, 2 is a battery, 3
Is a booster circuit, 4 is a starter relay, 5 and 6 are resistors, 7,
8 is a condenser, 9 is a generator section, 10 is an engine 11
Is a starter. The capacitors 7 and 8 are large-capacity capacitors, for example, electric double-layer capacitors are used.

[0005] The generator unit 9 is mechanically connected to the engine 10, and is driven by the engine 10 to generate power.
During traveling, the capacitors 7 and 8 are charged, and power is supplied to a vehicle load (not shown). The voltage of the battery 2 is boosted by the booster circuit 3 and the capacitors 7, 8
Is charged. The resistors 5 and 6 are voltage balancing resistors for preventing the charging voltages of the capacitors 7 and 8 from becoming unbalanced. Without this resistance, the charging voltage of a particular capacitor would be excessive and could be damaged.

The switch 1-2 of the key switch section 1 is a switch for sending an operation signal to the booster circuit 3. The booster circuit 3 starts the boosting operation in response to the operation signal.
The activation signal is issued shortly before starting. The reason is,
This is because, if the booster circuit 3 is always operated to keep the capacitors 7 and 8 in a charged state, the capacitors 7 and 8 are gradually discharged and power is wasted.

FIG. 2 is a diagram showing an example of a booster circuit.
This is a known DC-DC conversion circuit. In FIG. 2, 3-1 is an input terminal, 3-2 is an oscillation circuit, 3-3 is a switching transistor, 3-4 is a step-up transformer,
5 is a rectifier circuit, and 3-6 is an output terminal. Input terminal 3-
1, a battery voltage is applied.

When an operation signal from the switch 1-2 is given to the oscillation circuit 3-2, the switching transistor 3-
3 turns on and off. The alternating current generated when the battery voltage is turned on and off by the switching transistor 3-3 is supplied to the primary winding of the step-up transformer 3-4. A boosted alternating current is generated in the secondary winding of the step-up transformer 3-4, and is rectified by the rectifier circuit 3-5. The voltage output from the output terminal 3-6 is used for charging the capacitors 7, 8.

Next, the starting operation of the engine starting device shown in FIG. 3 will be described. Prior to starting, the switch 1-2 is turned on. The booster circuit 3 starts operating to charge the capacitors 7 and 8. When the charging is completed, the ST terminal of the key switch 1-1 is turned on. Then, the starter relay 4 is turned on, and the starter 1 is supplied from the capacitors 7 and 8.
1, a discharge current flows, and the engine 10 is started.

[0010] Conventional documents relating to the above-described engine starting device include, for example, Japanese Patent Application Laid-Open No. 2-2592.
No. 77, Japanese Patent Application Laid-Open No. 5-99105, and the like.

[0011]

[Problems to be solved by the invention]

(Problem) In the above-described conventional engine starting device, since the voltage balancing resistors 5 and 6 are always connected in parallel to the capacitors 7 and 8, the capacitors 7 and 8 are charged from the generator unit 9 during traveling. However, after that, there is a problem that the battery is gradually discharged through the resistors 5 and 6.

(Explanation of Problems) When the vehicle starts running, the capacitors 7, 8 discharged at the time of starting are charged by the power generation in the generator unit 9. However, between the time the engine is stopped and the next start, the charged electric charge is gradually discharged through the resistors 5 and 6 connected in parallel. In this case, energy that has been charged is lost, which is not preferable in terms of energy efficiency. If the amount of discharge is large, the amount of charge to be charged from the battery 2 at the next start must be increased, which leads to consumption of the battery. An object of the present invention is to solve such a problem.

[0013]

In order to solve the above-mentioned problems, the present invention comprises a plurality of capacitors each having a voltage-balancing resistor connected in parallel and connected in series,
An engine starting device that starts an engine by discharging a charge charged in the capacitor to a starter,
Switch means are connected in series to each of the resistors, and the switch means is turned on only when charging the capacitor from a battery or a generator unit.

[0014]

[Operation] A resistor for voltage balance is connected in parallel to each of the capacitors connected in series via switch means. When the capacitor is being charged from the battery or the generator, the switch is turned on to connect a resistor in parallel.
The switch is turned off to release the parallel connection. By doing so, it is possible to balance the charging voltage at the time of charging, and to prevent discharging when the battery is left in a charged state.

[0015]

Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 shows an engine starting device according to the present invention. Reference numerals correspond to those in FIG.
14 and 15 are diodes. The configuration differs from the conventional example of FIG. 3 in that the resistors 5 and 6 are connected in parallel to the capacitors 7 and 8 only when charging is being performed.

That is, the relay contacts of the relays 12 and 13 are
They are connected in series with the resistors 5 and 6, respectively, and are turned on only when charging from the battery 2 or the generator unit 9 and turned off when not charging. The charge from the battery 2 is detected by turning on the switch 1-2, and the charge from the generator unit 9 is detected by the output voltage of the L terminal.

Specifically, when the switch 1-2 is turned on, the connection configuration is such that an energizing current flows through the relay coils of the relays 12 and 13, and the output voltage appears when the generator unit 9 starts generating power. Terminals (later shown in FIG. 4) are connected to the relay coils of relays 12,13. The diodes 14 and 15 in these connection paths are for preventing a current from flowing in the reverse direction. In addition, it can be said that the diodes 14 and 15 form an OR circuit.

FIG. 4 is a diagram showing an example of the configuration of the generator unit 9. 9-1 is a power generation coil, 9-2 is a field coil, 9
-3 is a rectifier circuit, 9-4 is a regulator, L is an L terminal,
B is an output terminal, and F is a field terminal. Generating coil 9-1
Is rectified by the rectifier circuit 9-3, and the rectified output is taken out from the two terminals B and L. The output from the L terminal is also sent to the regulator 9-4. In the present invention, the voltage at the L terminal is also used for energizing the relay coils of the relays 12 and 13 in FIG.

Next, the operation will be described. At the time of starting, first, the switch 1-2 is turned on. Then, an operation signal is sent to the booster circuit 3 to start the boosting operation and the relay 1
An energizing current is supplied to 2,13. The relay contacts of the relays 12 and 13 are turned on, and the resistors 5 and 6 are connected in parallel to the capacitors 7 and 8. Therefore, during charging with the output voltage of the booster circuit 3, the voltage balance of the capacitors 7, 8 is maintained, and the voltage of one of the capacitors does not become abnormally high. When charging from the battery 2, there is no other way to operate the booster circuit 3, so that it can be detected by turning on the switch 1-2. Therefore, the current from the switch 1-2 flows to the relays 12 and 13 via the diode 14.

When it is considered that the capacitors 7 and 8 are sufficiently charged, the ST terminal of the key switch 1-1 is turned on, and the starter relay 4 is turned on. Capacitors 7, 8
Flows through the starter 11, and the engine 10 is started. When the engine 10 is started, the generator unit 9 starts generating power.

After the start of the engine, both the ST terminal and the switch 1-2 are turned off. When the switch 1-2 is turned off, charging from the battery 2 is stopped, but at the same time, the energization of the relays 12, 13 is also stopped, and the resistors 5, 6 are disconnected from the parallel connection. On the other hand, the capacitors 7 and 8 are charged by the voltage generated by the generator unit 9. At this time, the current from the L terminal of the generator section 9 is applied to the relays 12, 1
The current flows to 3 and is energized, and the resistors 5 and 6 are again connected in parallel. When the switch 1-2 is turned off slightly later, the current from the L terminal is already flowing when the switch 1-2 is turned off. Therefore, the resistors 5 and 6 are connected in parallel. Maintain the state as it is continuously.

When the vehicle is stopped and the power generation of the generator unit 9 is stopped, there is no current from the L terminal.
2, 13 are deactivated and the resistors 5, 6 are disconnected from the parallel connection. Since there is no discharge path via the resistors 5 and 6, the discharge of the capacitors 7 and 8 is reduced. for that reason,
Even if the time until the next start is long, most of the charged energy can be retained.

In the above-described embodiment, a relay is used as a switch for disconnecting the resistors 5 and 6, but other switch such as a semiconductor switch may be used. In addition, the voltage at the L terminal is focused on as a target for detecting the power generation state of the generator unit 9. However, since it is only necessary to detect the power generation state, another amount of electricity (voltage or current of another part) is detected. It is also possible to target. If the voltage specification of the starter is such that it can be directly driven by the battery voltage, the booster circuit 3 is unnecessary.

[0024]

As described above, according to the engine starting apparatus of the present invention, a resistor for voltage balance is connected in parallel to each of the series-connected capacitors for driving the starter through the switch means. When the capacitor is being charged from the battery or the generator, the switch is turned on to connect the resistor in parallel, and when the battery is not charged, the switch is turned off to release the parallel connection. I do. Therefore, the voltage can be balanced at the time of charging, and the discharge can be prevented when the battery is left in the charged state.

[Brief description of the drawings]

FIG. 1 shows an engine starter according to the present invention.

FIG. 2 illustrates an example of a booster circuit.

FIG. 3 shows a conventional engine starting device.

FIG. 4 is a diagram showing an example of a configuration of a generator unit.

[Explanation of symbols]

1. Key switch section 1-1 Key switch 1-2
Switch, 3 battery, 3 booster circuit, 3-1 input terminal, 3-2 oscillator circuit, 3-3 switching transistor, 3-4 booster transformer, 3-5 rectifier circuit, 3
-6: output terminal, 4: starter relay, 5, 6: resistor,
7, 8: condenser, 9: generator unit, 9-1: power generation coil, 9-2: field coil, 9-3: rectifier circuit, 9-4:
Regulator, 10 engine, 11 starter, 1
2,13 ... relay, 14,15 ... diode

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-63-314132 (JP, A) JP-A-3-159528 (JP, A) JP-A-2-271072 (JP, A) 37873 (JP, U) (58) Field surveyed (Int. Cl. ⁷ , DB name) F02N 11/08

Claims (1)

(57) [Claims] 1. An engine starting device, comprising: a plurality of capacitors connected in parallel with a resistor for voltage balance; a plurality of capacitors connected in series; and starting an engine by discharging a charge charged in the capacitors to a starter. An engine starting device, wherein switch means is connected in series to each of the resistors, and the switch means is turned on only when charging the capacitor from a battery or a generator unit.