JPH10270010A - Storage battery with protection device - Google Patents

Abstract

(57) [Summary] [Purpose] Even if a fault that causes an overcurrent occurs on either the load side or the storage battery side, the current is reliably shut off to minimize the spread of damage to the load side and the storage battery. It is intended to provide a storage battery with a protection device that can be stopped as easily as possible. [Structure] A protection device having a function of interrupting a current when an overcurrent occurs is directly incorporated into a current extraction terminal of a storage battery, or a small-diameter portion which is cut off by a Joule heat generated by an overcurrent in the current extraction terminal. Provide.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a highly safe storage battery incorporating a protection device.

[0002]

2. Description of the Related Art Storage batteries are widely used in various devices such as gasoline vehicles and electric vehicles. The storage battery has a configuration in which a plurality of electrode groups are immersed in an electrolyte filled in a synthetic resin case, these electrode groups are electrically connected, and the current extraction terminals are led out of the case. Specifically, as shown in FIG.
A configuration in which a positive electrode current extraction terminal 2a and a negative electrode current extraction terminal 2b are arranged on the upper surface of the substrate so as to be separated from each other is known as a typical example. Such a storage battery a may be used alone, or may be used in combination of two or more in order to obtain necessary electric power. Particularly, in an electric vehicle, an electric carrier, or the like, the storage battery a is required to drive an electric motor. In order to obtain a voltage, a plurality of them are connected in series as shown in FIG. 5 and used in a casing b.

In such a storage battery a, the current extraction terminal 2
When a circuit abnormality or the like occurs between the terminals a and 2b and the load increases, the reaction between the electrolyte and the electrode plate intensifies and the current extraction terminals 2a and 2b
It is known that an overcurrent flows between b and as a result, the resin case 1 cannot withstand the expansion pressure of the gas generated from the electrolyte, and the electrolyte leaks or flammable gas is generated. These are recognized as problems to be solved because they cause serious accidents such as explosions and fires, as well as damage to the storage batteries.

A countermeasure against such a problem according to the prior art is to provide a protection device for interrupting the current when an overcurrent flows on the load side to which power is supplied or between the load side and the storage battery. Was. For example, in a case where an additional voltage taken out of storage batteries connected in series like an electric vehicle is supplied to an electric motor, as shown in FIG. 6, a load side c including an electric motor d and a casing b containing a storage battery group are provided. A protective device such as a fuse e or a circuit breaker is provided between the two, or a protective device (not shown) is provided at some suitable places inside the load side c.

[0005]

However, such a measure can cope with a failure occurring inside the load, but cannot deal with a failure occurring outside the load, that is, the storage battery. . For example, in the example shown in FIG. 6, it is a reality that there is no defense against a failure in the casing b. According to the inventor's experience, a significant part of the cause of battery damage and fire accidents is a short circuit between the current extraction terminals 2a and 2b of each storage battery or between current extraction terminals of adjacent storage batteries. I know that. These are storage batteries a due to the impact of a collision or the like.
The more frequent occurrence is caused by a work error during maintenance and inspection of the storage battery.
Work in the narrow casing b is apt to be erroneous, and connection is apt to be erroneous after inspection, which is a factor that cannot be ignored in the accident. The present invention has been made in view of such a situation, and it is possible to cope with a circuit abnormality on the load side, and also to supply a current immediately even when a circuit abnormality on the storage battery side, for example, a short circuit between terminals occurs. It is intended to propose a technology capable of stopping and protecting the storage battery and the load side.

[0006]

SUMMARY OF THE INVENTION The present inventor has worked on solving the above problems, and as a result of various studies, it has been found that it is preferable to provide a protection device having a function of cutting off excess current at a position closest to a power generation source. I came to the conclusion. In the course of the study, it was considered to provide a protection device between one end of a plurality of connected storage batteries and a current extraction unit provided in a casing that accommodates these storage battery groups. Judgment was not possible, and the above conclusion was reached.
Then, as a result of examining a specific place where the protection device is provided, it was concluded that providing the protection device at the current extraction terminal (terminal) is optimal.

The present invention completed on the basis of such an idea is characterized in that a protection device having a function of interrupting excessive current is provided directly on a current extraction terminal. One is a method in which a protection device is incorporated inside the current extraction terminal, and the other is a method in which the shape of the current extraction terminal is devised to give the current extraction terminal a function as a practical protection device. The invention according to claim 1 is characterized in that a protection device for blocking the passage of a current taken out through the current taking-out terminal is incorporated inside the current taking-out terminal of the storage battery. A second aspect of the present invention is characterized in that a fuse is used as the protection device in the first aspect. A third aspect of the present invention is characterized in that a circuit breaker is used as the protection device in the first aspect. Claim 4 is intended to exert a protection function against overcurrent by devising the shape of the current extraction terminal, and when an overcurrent exceeding a predetermined value flows to the root of the current extraction terminal of the storage battery. In addition, a small-diameter portion that is blown out by Joule heat generated in the portion is provided. In the configuration of the fourth aspect, there is a possibility that the blown terminal head may re-contact the current extraction terminal remaining on the storage battery side. In order to prevent this, another portion of the current extraction terminal which has an inner diameter substantially matching the outer diameter of the narrow portion of the current extraction terminal and is located above and below the small diameter portion. It is preferable to interpose an annular insulating member having an outer diameter larger than the outer diameter of the small diameter portion.

[0008]

In the storage battery with a protection device according to the present invention, the protection device provided at the current extraction terminal of the storage battery is provided regardless of whether a fault that causes an overcurrent occurs on the load side of the electric motor or the like or on the storage battery side. In operation, the supply of electric current to the load side is interrupted to prevent further damage from spreading to the load side and the storage battery. When a plurality of storage batteries are connected as in an electric vehicle, the safety of the whole system is maintained by the operation of any one of the plurality of storage batteries. In addition, since the protection device is provided directly at the current extraction terminal closest to the power generation source, the protection device operates even when the current extraction terminals are directly short-circuited, and can reliably prevent the failure from expanding. it can. When the protection device is a fuse as in claim 2,
When the fuse is blown, the current is cut off, and restoration is performed by replacing the blown fuse. Further, when the protection device is a circuit breaker, the current is cut off by operating the circuit breaker, and the recovery is performed by lowering or pushing down the switch of the circuit breaker to the power supply side. Further, in the case where the current extraction terminal is provided with a small-diameter portion that is blown by an overcurrent as in claim 4,
If an overcurrent that is equal to or more than a predetermined value designed in advance flows, the small diameter portion is blown by Joule heat, and the current is interrupted. In this case, recovery is performed by replacing the blown storage battery.
If the current extraction terminal is configured to be replaceable,
This can be dealt with simply by replacing the current extraction terminal without discarding the storage battery. Further, when an annular insulating member is interposed in the small-diameter portion as in claim 5, the fused terminal head is prevented from coming into contact with the current extraction terminal remaining on the storage battery side, and the current interruption is ensured. Be transformed into

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The details of the present invention will now be described with reference to the illustrated embodiments. The present invention is characterized in that a function of interrupting an overcurrent is provided to a current extraction terminal itself of a storage battery, and according to the form, a method of incorporating a protection device inside the current extraction terminal and a method of devising a shape of the current extraction terminal itself. , And two types. First, an embodiment of the system will be described.

FIGS. 1 and 2 show a case where a protection device is incorporated in a current extraction terminal. In FIG. 1 and FIG. 2, current extraction terminals indicated by reference numerals 10 and 20 are current extraction terminals 2a in FIG.
(Positive electrode) or 2b (negative electrode). The protection device may be provided only on one of the positive electrode and the negative electrode of the current extraction terminal. FIG. 1 shows a case where a fuse 11 is used as a protection device. The current capacity of the fuse is set to the maximum current capacity of the device to be mounted or a value obtained by multiplying the maximum current capacity by a safety factor. The fuse 11 is installed in the current extracting terminal 10 in a replaceable state so that the fuse 11 can be replaced when it is blown. Various specific embodiments of the incorporation are conceivable. For example, as shown in FIG. 1, the current extraction terminal 10 may be configured to be separated into a pole 13 and a terminal head 17, and a fuse 11 may be interposed between the pole 13 and the terminal head 17. Can be 1 is formed with a vertical hole 14 for receiving the lower half including one contact 11b of the fuse 11 at the upper end of a pole 13 penetrating a single lid 12 of a storage battery. Around the periphery, a Teflon thread bush 15 with an external thread cut on the outer peripheral surface is attached.
A vertical hole 18 that receives the upper half of the terminal head 17 including the other contact 11 a of the fuse 11 is formed in the terminal head 17 externally fitted to the pole 13. A female screw corresponding to the male screw is engraved on the inner peripheral surface of the terminal head 17. To assemble the current extracting terminal 10, the fuse 11 is inserted into the vertical hole 14 of the pole 13 on which the Teflon thread bush 15 is mounted via the spring 9 and pushed in against the elastic restoring force of the spring 9. Teflon thread bush 15 and Teflon washer 16 (hereinafter referred to as Teflon washer 1)
6) is interposed and the terminal head 17 is externally fitted to the pole 13. Also, a Teflon washer 19 is interposed between the terminal head 17 and the single lid 12. When the single lid 12 is made of a synthetic resin, the Teflon washer 19 is not necessarily required. The reason why Teflon is used for the thread bush and the washer is that it has excellent insulation and heat resistance, and other materials having the same characteristics may be used. The storage battery having such a current extraction terminal 10 is used alone, or a plurality of storage batteries are connected in series to obtain a required voltage. If an overcurrent exceeding the current capacity of the fuse 11 occurs due to a circuit failure or the like in the storage battery, the fuse 11 is immediately blown, interrupting the current, and preventing damage from spreading to other storage batteries or the load side. I do. Therefore, the worst case can be done with only one storage battery. When the storage battery is not damaged, the terminal is removed and the fuse 11 is replaced when the storage battery is not damaged, and when the storage battery is damaged, the storage battery is replaced. .

FIG. 2 shows a case in which a circuit breaker 21 is incorporated as a protection device, and when an overcurrent occurs, the push button 22 projects outward from the top surface of the terminal head 27 by spring pressure. Circuit breaker 2
Reference numeral 1 denotes one contact 2 as in the case of the fuse 11.
A vertical hole 28 whose upper half including 1b is formed in the terminal head 27.
The lower half including the other contact 21 a is positioned in a vertical hole 24 formed in the pole 23.
In the example shown in the figure, the circuit breaker 21 is fixed.
Although it is directly performed by the screw part formed on the outer peripheral surface,
Separately, an intervening member for mounting or fixing by another method is appropriately adopted. When an overcurrent occurs, the storage battery having the current extracting terminal
Jumps out from the top surface of the terminal head 27 and the current is cut off. The recovery is performed by pressing the push button 22. In the figure, reference numeral 29 denotes a Teflon washer 29 interposed between the single lid 12 and the terminal head 27.

In the above-described configuration, a protection device such as a fuse or a circuit breaker is incorporated in the current extraction terminal. However, the one shown in FIG. 3A is designed to reduce overcurrent by devising the shape of the current extraction terminal itself. The current interrupt function for
This is a case in which the current extraction terminal itself has a function as a protection device. That is, in this embodiment, the narrow portion 34 is provided at the boundary between the pole 33, which is the base of the current extraction terminal, and the terminal head 37 connected to the pole. The diameter r of the small-diameter portion 34 is set such that the small-diameter portion 34 is melted by Joule heat generated when an overcurrent exceeding a predetermined value passes. An insulating ring 35 made of Teflon is provided around the small-diameter portion 34 so that the blown terminal head 37 does not contact the pole 33 remaining on the storage battery side. The size of the insulating ring 35 is set such that the inner diameter thereof substantially matches the diameter r of the small-diameter portion 34 and the outer diameter R of the insulating ring 35 from the viewpoint of reliably preventing contact between the blown terminal head 37 and the pole 33. It is preferable to set the current extraction terminals located above and below the reduced diameter portion to be larger than the maximum outer diameters of the other portions of the current extraction terminals, namely, the fused terminal head 37 and the pole 33 remaining on the storage battery side. . As shown in FIG. 3B, the insulating ring 35 is provided with a cut-out portion 35b as shown in FIG. 3B so that the insulating ring 35 can be easily attached to the small-diameter portion 34. Conceivable. In the storage battery according to this embodiment, when an overcurrent flows, the small-diameter portion 34 is melted and cut off by the Joule heat generated thereby. The current value when the terminal head 37 is blown can be controlled by changing the thickness of the small-diameter portion 34, but the material may be changed to make the fusing easier.

[0013]

The storage battery with a protection device according to the present invention is either a protection device incorporated inside the current extraction terminal of the storage battery or is blown by Joule heat generated when an overcurrent flows at the root of the current extraction terminal. The configuration was such that a small diameter portion was provided. As described above, in the present invention, since the protection device is provided at the current extraction terminal itself of the storage battery that is the power generation source, the location of the failure that causes the overcurrent is either the load side or the storage battery side. Also acts reliably to protect the devices and storage batteries connected to the load side. In particular, when storage batteries are connected in series, since a protection device is provided for each storage battery, even in the worst case, only one storage battery can be damaged, and the damage can be prevented from spreading. Therefore, the leakage of the electrolyte and the generation of flammable gas, which have conventionally occurred due to the short circuit between the terminals during the maintenance and inspection of the storage battery, are eliminated, and the spread to a serious accident can be prevented.

In the storage battery with the protection device according to the third aspect, since the circuit breaker is also used as the protection device, the recovery after the current interruption is easy.

According to a fourth aspect of the present invention, there is provided a storage battery with a protection device, wherein a small-diameter portion is provided at a root portion of a current extraction terminal, and the small-diameter portion is blown off by Joule heat generated when an overcurrent flows. Therefore, a storage battery with a simple configuration and excellent safety can be provided with little increase in manufacturing cost.

[Brief description of the drawings]

FIG. 1 is a sectional view of an essential part showing an embodiment in which a fuse is incorporated in a current extraction terminal.

FIG. 2 is a sectional view of a main part showing an embodiment in which a circuit breaker is incorporated in a current extraction terminal.

FIG. 3A is a sectional view of a main part showing an embodiment in which a small-diameter portion is formed at the root of a current extraction terminal, and FIG. 3B is a plan view showing an example of an insulating ring used in the embodiment.

FIG. 4 is a perspective view showing the appearance of a storage battery.

FIG. 5 is an explanatory view showing a power supply in which a plurality of storage batteries connected in series are housed in a casing.

FIG. 6 is a circuit diagram showing an outline of a conventional example in which a protection device is provided between a storage battery connected in series and a system including a load such as an electric motor.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Resin case 2a Positive current extracting terminal 2b Negative current extracting terminal a Storage battery b Casing c Load side d Electric motor e Fuse 9 Spring 10, 20 Current extracting terminal 11 Fuse 11a, 11b Contact 12 Single cover 13 Pole pole 14 Vertical hole 15 Teflon thread bush 16 Teflon washer 18 Vertical hole 19 Teflon washer 21 Circuit breaker 21 a, 21 b Contact 22 Push button 24 Vertical hole 27 Terminal head 28 Vertical hole 29 Teflon washer 33 Polar column 34 Small diameter portion 35 Insulation ring 35 b Notch 37 Terminal head

Claims (5)

[Claims] 1. A storage battery with a protection device, wherein a protection device for blocking the passage of a current taken out through the current extraction terminal is incorporated inside a current extraction terminal of the storage battery. 2. The storage battery with a protection device according to claim 1, wherein the protection device is a fuse. 3. The protection device according to claim 1, wherein the protection device is a circuit breaker. 4. A protection device characterized in that a small-diameter portion is provided at a root portion of a current extraction terminal of a storage battery when an overcurrent exceeding a predetermined value flows and is melted by Joule heat generated in the portion. Attached storage battery. 5. An outer diameter of the current extraction terminal having an inner diameter substantially corresponding to an outer diameter of the small-diameter portion, and an outer diameter larger than the outer diameter of another portion of the current extraction terminal located above and below the small-diameter portion. The storage battery with a protection device according to claim 4, wherein an annular insulating member having the small diameter portion is interposed.