JP2000228225A - Direct current power supply device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To short-circuit both electrodes of a battery by a conductive member to prevent leakage to the outside when water enters of a battery case by surrounding plural high voltage power supplies formed by plural batteries with the conductive member. SOLUTION: To drive a motor of an electric vehicle, plural batteries are connected in series to form a battery block of sealed structure, and plural blocks are connected in series to from a set battery 10 for obtaining high voltage of 200-300 V. The set battery is stored in a resin-made waterproof insulating box 12, and power is supplied to the outside by an output line 14. Further, the insulating box 12 is surrounded with a net-like conductive net 16 made of copper. When water enters the insulating box 12 by some cause, both electrodes of the battery are short-circuited through the conductive net 16. Thus, at the time of submersion or the like, the current can be prevented from leaking out in a simple constitution. The conductive net 16 is put in a floating state by a frame or the like, where by the conductive net 16 is also functioned as a shield.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a DC power supply for driving a motor, and more particularly to a countermeasure against flooding in a high-voltage DC power supply mounted on an electric vehicle.

[0002]

2. Description of the Related Art Conventionally, electric vehicles, hybrid vehicles and the like are equipped with a battery as a power supply for driving a motor. In particular, this battery must drive a high-output motor, and a battery that outputs a high voltage is used.
Usually, a battery in which a plurality of battery cells are connected in series and an output of 200 to 300 V is obtained is used.

When an electric vehicle or the like equipped with such a power supply device is flooded and the power supply device is immersed in water, a short circuit may occur. Therefore, there are various proposals as a countermeasure against this leakage. For example, Japanese Patent Application Laid-Open No. 9-107628
In the publication, when water is flooded, water is positively introduced into the waterproof case using a float valve to prevent leakage to the outside.

[0004]

However, in this conventional example, a device for introducing water into the battery case using a float valve or the like is required, and the device is complicated and large. There was a point.

[0005] The present invention has been made in view of the above problems, and has as its object to provide a DC power supply device that can take measures against flooding with a simple configuration.

[0006]

SUMMARY OF THE INVENTION The present invention relates to a DC power supply for driving a motor, comprising a plurality of battery cells connected in series to output a high voltage. A conductive member arranged to surround the power supply,
It is characterized by having. By providing the conductive member in this manner, when the battery is immersed, the conductive member causes a short circuit between the two electrodes of the battery, and the possibility of current flowing to the outside can be reduced.

[0007]

Embodiments of the present invention (hereinafter referred to as embodiments) will be described below with reference to the drawings.

FIG. 1 is a schematic diagram showing the configuration of the embodiment. The battery 10 includes a plurality of battery cells. Normally, a plurality of battery cells are connected in series to form a sealed battery block, and a plurality of battery blocks are connected in series to obtain a battery (assembled battery) 10 having a predetermined output voltage. The battery pack 10 is a secondary battery, for example, a nickel-metal hydride battery or the like.

The battery pack 10 is housed in an insulating box 12 made of resin. This insulation box 12
Is waterproof, prevents water or the like from entering, and prevents the occurrence of a battery short circuit.

An output line 14 connected to both terminals of the battery pack 10 is drawn out of the insulating box 12 and connected to a motor via an inverter or the like. Note that the output line 14 is also coated with an insulating material.

In such an assembled battery 10, a problem such as electric leakage does not normally occur, but if the insulated box 12 is damaged for some reason and is flooded, the assembled battery 10 is not damaged.
Current may flow to the outside.

If a short circuit occurs between the positive and negative electrodes of the battery pack 10,
The power stored in the battery pack 10 is consumed between the positive and negative electrodes, and no current flows outside, and there is no problem. However, if water is flooded in a state where the output line 14 of one positive electrode is broken, current may flow outside through the flooded water (for example, seawater).

In this embodiment, the insulating box 12
Is surrounded by a conductive member (conductive net) 16.
The conductive net 16 can be formed using, for example, a copper wire. Therefore, when the above-mentioned inundation occurs, the probability that both electrodes are short-circuited via the conductive net 16 becomes very high. Thus, with a simple configuration, it is possible to prevent the current from the battery pack 10 from flowing outside.

Here, the conductive net 16 is not connected to a frame or the like, but is preferably in a floating state. Thus, when the conductive net 16 is immersed in seawater or the like, the conductive net 16 functions as a shield.

Further, by connecting the conductive net 16, frame and the like to the cathode of the battery 10, the conductive net 1
It is also possible to set 6 to be always 0 potential so that no current flows to the outside. In this case, special measures are required to prevent the occurrence of electric leakage during normal use.

The conductive net 16 can be formed, for example, in a string shape as shown in FIG. With such a configuration, the conductive net 16 can be made relatively lightweight.
Further, even in a situation in which the insulating box 12 is broken by an impact, it is unlikely that all of the conductive nets 16 will be cut, and the outflow of current using the conductive nets 16 to the outside is maintained. The entire conductive net 16 may be a mesh-like or a plate-like.
Further, it is preferable to use a bare wire or a porous coating that allows easy passage of water so as to easily come into contact with water from the outside. In addition, other good conductors such as aluminum besides copper can be used for the conductive net 16.

[0017]

As described above, by providing a conductive member, the possibility of short-circuiting between the two electrodes of the battery due to the presence of the conductive member when water is immersed can be reduced.

[Brief description of the drawings]

FIG. 1 is a diagram illustrating a configuration of an embodiment.

FIG. 2 is a diagram showing a configuration of a conductive net.

[Explanation of symbols]

10 batteries (assembled batteries), 12 insulation boxes, 14 output wires, 16 conductive nets.

Claims (1)

[Claims] 1. A DC power supply for driving a motor, comprising: a plurality of battery cells connected in series; a high-voltage DC power supply for outputting a high voltage; and a conductive element arranged to surround the high-voltage DC power supply. A DC power supply, comprising: a conductive member.