JPH05106539A - Starter for automobile - Google Patents

Abstract

(57) [Summary] (Correction) [Purpose] To provide a compact starting device for an automobile with excellent startability. A storage battery 1 and an electric double layer capacitor 2 connected in parallel via a diode 3 are provided, and the diode 3
Indicates that the positive electrode is connected to the positive terminal of the storage battery 1 and the negative electrode is connected to the positive terminal of the electric double layer capacitor 2, and the ignition 4 is connected to the capacitor 2.
The load other than the ignition 4 is the starting device for a vehicle that is connected in parallel to the storage battery 1.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a starting device for an automobile.

[0002]

2. Description of the Related Art In recent automobiles, the load on storage batteries has been alleviated due to remarkable improvements in electrical components. In particular, the alternator, which is the power generation section, is remarkably improved, and the storage battery is always charged even when idling unless the maximum load on the vehicle is applied. For this reason, in Europe and the United States, when displaying the performance of storage batteries, the
CCA (cold cranking current) is used instead of capacitance display. This shows how large a discharge can be made within 30 seconds immediately after the discharge. As described above, as long as the starting performance can be secured, the alternator bears all the power supply to the load when the engine is rotating, so that a storage battery having a particularly large capacity is unnecessary.

Since CCA tends to be emphasized in Japan as well, the CCA is improved by reducing the pitch between electrode plates to reduce the internal resistance. According to this, the storage battery performance can be improved and the weight of the storage battery can be reduced. In addition to this, there are some that employ a dual power supply system. This is to separately provide a storage battery dedicated to starting and a storage battery dedicated to load so that the starting storage battery is always maintained in an optimum state of full weight. In addition, an electric double layer capacitor has also been experimentally developed as a starting storage battery.

[0004]

However, in the case where the pitch between the electrode plates is made small and the internal resistance is made small, the electrode plate and the separator are made thin, so that the service life becomes proportionally short. There is a point. Although the two-system power supply system is very reliable, it has the drawback of being inferior in weight efficiency and volumetric efficiency due to the need to install a storage battery for load, and therefore it has been put to practical use even though it is said to be an ideal system. Absent. In the case of using the electric double layer capacitor together, most of the starting current is carried by the capacitors connected in parallel when the starting storage battery is deteriorated, and thus it is required that the capacitor can discharge a large current of 200 to 300 A for 1 second. To be done. This capacitor requires a capacity of several farads per discharge. Even if an electric double layer capacitor having a high capacity density is applied, a space for a storage battery for starting is required, which is larger than the storage battery space of a two-system power system. With the recent high performance of automobiles,
Since the inside of the bonnet is densely packed with various devices, the increase in space is a disadvantage in the situation where compactness is required.

The present invention has been made to solve the above problems, and an object of the present invention is to provide a compact starting device for an automobile, which is excellent in startability.

[0006]

Therefore, a storage battery and an electric double layer capacitor connected in parallel via a diode are provided, and the diode has a positive electrode at the positive terminal of the storage battery and a negative electrode at the positive terminal of the electric double layer capacitor. Those connected, the ignition is connected to the capacitor, the load other than the ignition is connected in parallel to the storage battery, by solving the above problems by providing a starting device for automobiles Is.

[0007]

The starting characteristic is determined by the engine speed at the time of starting and the voltage applied to the ignition. The conventional so-called single power supply system is currently widely used in automobiles, and the on-vehicle full load is supplied from one storage battery (6 cells). Therefore, when the storage battery voltage drops due to the large current discharge at the time of starting, various load voltages connected in parallel to the storage battery also drop to the same potential. This voltage is 7
When it becomes V or less, engine start becomes impossible due to a decrease in engine speed and a decrease in ignition applied voltage. However, as a result of the experiment, about 1
It has been found that when the voltage of 2V is applied by another power source, the engine can be started even if the storage battery pressure at the time of starting is reduced to 3 to 4V. The present invention was made based on such findings.

The present invention will be described in detail below with reference to specific examples. FIG. 1 is a circuit configuration diagram showing an embodiment of the present invention.
1 is a storage battery, 2 is an electric double layer capacitor, 3 is a reverse current element diode, 4 is an ignition, 5 is an alternator, 6
Is a starter, and 7 is an on-vehicle load other than the above. The double-layer capacitor 2 is in parallel with the storage battery 1, and the diode 3 serving as a reverse current element is inserted between the double-layer capacitor 2 and the storage battery 1 to form a circuit in which the electric double-layer capacitor 2 is constantly peak-charged.

The load flowing to the ignition 4 is about 2 to 3 A, and the internal resistance of the ignition is 1
2V and the ignition current is 2A
That is, V / 2A = 6Ω. Further, when the capacity of the electric double layer capacitor 2 is 0.5 F (farad), the time constant becomes about 3 seconds. Assuming that the starting time is 0.1 seconds, the voltage of the electric double layer capacitor 2 does not discharge to the storage battery side because the backflow element 3 is interposed, and the voltage before the discharge of the storage battery is maintained at about 12V. As described above, the engine can be started if the starting voltage is 3 to 4 V or more even if the storage battery is in the end of life state and 7 V or more required for starting cannot be secured. Thus, stabilizing the ignition power supply is very effective in improving the starting performance.

The withstand voltage of the electric double layer capacitor is 1.5V.
It is as low as ~ 3.0V, and when adopted in the present invention, the maximum voltage is 15V in the battery charger for the automobile, so 6
It is necessary to stack an electric double layer capacitor of 8 cells. The conventional one that also uses the electric double layer capacitor for starting requires 200 to 300 A for the starting current, and requires a capacitance of several farads to maintain this current. However, according to the present invention, the ignition is performed. It is only necessary to keep the load 2-3A. The discharge current from the capacitor is about 1/100 that of the conventional one, and the capacitor volume is 1/4, which makes it possible to greatly reduce the size. This volume corresponds to 1/6 of the starting storage battery.

FIG. 2 (a) shows the starting characteristics of the storage battery in the end-of-life state of the conventional single power supply system. The solid line shows the storage battery voltage, and the dotted line shows the ignition load voltage, both of which have synchronized voltage characteristics. In this case, starting was impossible because both voltages were about 5V. FIG. 2 (b) is a diagram showing the starting characteristics of the vehicle starter according to this embodiment, and the storage battery voltage is shown in FIG. 2 (a).
Although it has dropped to about 5V as in the above, the ignition voltage is maintained at a high voltage of 11V, so that the engine can be started.

[0012]

The starting voltage of an automobile was considered to be 7 V or higher. However, like the automobile starter according to the present invention, by backing up the ignition load with a capacitor, the engine can be started even if the starting voltage of the storage battery drops to 3 to 4 V, which is compact and excellent in startability. It has become possible to provide a starting device for an automobile.

[Brief description of drawings]

FIG. 1 is a circuit configuration diagram showing an embodiment of the present invention.

FIG. 2 is a diagram showing a starting characteristic.

[Explanation of symbols]

 1 Storage Battery 2 Electric Double Layer Capacitor 3 Diode 4 Ignition

Claims (1)

[Claims] 1. A storage battery 1 and an electric double layer capacitor 2 connected in parallel via a diode 3, the diode 3 having a positive electrode at the positive terminal of the storage battery 1,
The negative electrode is connected to the positive terminal of the electric double layer capacitor 2, the ignition 4 is connected to the capacitor 2, and the vehicle-mounted loads other than the ignition 4 are connected in parallel to the storage battery 1. A car starter.