JP2001351594A - Pack battery - Google Patents

Abstract

PROBLEM TO BE SOLVED: To accurately detect water penetration into a pack battery by means of a water detection seal. SOLUTION: A battery main body 20 and a protection circuit 30 for the battery main body 20 are housed inside a case 10, and the water detection seal 33 whose color changes when it gets wet with water is arranged in a circuit base board 31 of the protection circuit 30. In the case 10, an observation hole 18 is formed in the position matching the water detection seal 33 and closed by a translucent protection seal 34. Because the water detection seal 33 is positioned on the circuit base board 31, water penetration to the protection circuit 30 can be surely detected.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a battery pack capable of detecting inundation.

[0002]

2. Description of the Related Art For example, a secondary battery used in a portable telephone or the like has a battery body and a protection circuit integrally housed in an outer case for convenience of handling. However, since mobile devices such as mobile phones are often used outdoors, there is a possibility that rainwater may enter the battery pack when it rains. It is also conceivable that a mobile phone or a battery pack may be dropped into water due to careless handling. In such a case, if water enters the battery pack, an electrical short circuit occurs in the protection circuit, and an unexpected situation such as abnormal heat generation of the battery may occur.

[0003] In recent years, in order to detect the presence or absence of water in the battery pack, for example, as disclosed in Japanese Patent Application Laid-Open No. H11-144695, a water detection method in which the battery body in the outer case is discolored by being wetted with water. There is provided a battery pack having a structure in which an observation hole for observing a state of a water detection seal is formed in an outer case while attaching a seal. According to this, for example, when water enters the battery pack by dropping the mobile phone into water, the water adheres to the water detection seal of the battery body and changes its color, and this is observed from the outside to detect the inundation. Therefore, accident prevention measures such as battery replacement can be taken.

[0004]

However, considering the situation where water enters the battery pack, water is often flooded near the terminal for connecting the battery body to the outside. Portions of the outer case other than the terminals can be easily and completely sealed by, for example, ultrasonic welding of plastic, but the terminal portion must be exposed to the outside, so there is a slight gap between the outer case and the outer case. This is because water is easily generated from here.

However, in the conventional battery pack, since a water detection sticker is attached to the battery body, even if a small amount of water is generated near the terminal and the water adheres to the protection circuit near the terminal, the water is still absorbed by the battery. If the water detection seal does not reach the water detection seal of the main body, the water detection seal does not change its color. For this reason, the user judges that the inundation has not occurred, and there is a concern that an unexpected situation such as abnormal heat generation of the battery pack may be caused.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a battery pack that can reliably detect inundation that may lead to an abnormal situation.

[0007]

According to a first aspect of the present invention, there is provided a battery pack comprising a battery body and a protection circuit for the battery in an outer case.
The circuit board of the protection circuit is provided with a water detection seal that changes color when wet with water, and an observation hole is formed in the outer case at a position corresponding to the water detection seal, and the observation hole is formed with a light-transmitting protective seal. It has a feature in that it is configured to be covered by.

[0008] The invention of claim 2 is characterized in that a plurality of electrodes connected to a battery main body are arranged on the circuit board, and a water detection seal is provided between the electrodes. According to a third aspect of the present invention, in the first or second aspect, an adhesive for sticking to the outer case is applied to an outer peripheral portion of the protective seal, and a non-transparent material is applied corresponding to an application area of the adhesive. The feature is that the optical part is formed.

The invention according to claim 4 is characterized in that the water detection seal is integrated with the protection seal with an extra water gap.

[0010]

According to the first aspect of the present invention, since the water detection seal is provided on the circuit board of the protection circuit, it is possible to reliably detect water infiltration into the protection circuit. In addition, since the observation hole of the outer case is covered with a protective seal, when the battery pack is removed from the device body, wet fingers accidentally touch the water detection seal and the water detection seal may be discolored by mistake. This can be reliably prevented.

According to the second aspect of the present invention, since the water detection seal is provided between the electrodes, more accurate water infiltration is performed in accordance with the fact that water easily enters the outer case from the electrode portion. The detection can be performed and the safety is enhanced. According to the third aspect of the present invention, since the protective seal is stuck to the outer case with an adhesive, the assembling work can be performed efficiently, and the adhesive applied portion, which tends to irregularly reflect white from the outside, is not translucent. Since it can be hidden by the part, the degree of discoloration of the water detection seal can be reliably observed. According to the fourth aspect of the present invention, since the water detection seal and the protection seal are integrated in advance, the assembling work becomes more efficient, and water adheres to the water detection seal from a finger during the assembling work. Can be reliably prevented.

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment in which the present invention is applied to a battery pack for a portable telephone will be described below with reference to FIGS.

As shown in FIG. 2, the battery pack has a flat rectangular battery body 20 and a protective circuit 3 inside an outer case 10 as shown in FIG.
0 is accommodated. The outer case 10 is located on the back of a mobile phone (not shown) and is slightly rounded,
It is configured as a two-piece type with a painted plastic bottom plate 11 and a plastic lid 12 that covers it.
Both are hermetically combined by, for example, ultrasonic welding. The case 12 includes a battery accommodating section 13 accommodating the battery main body 20 and a protection circuit accommodating section 1 connected thereto.
4 are integrally formed, and an engaging portion 15 is formed at an end of the lid portion 12 for attachment to a mobile phone.

The protection circuit 30 is configured by mounting various electronic components on a circuit board 31 and has a function of interrupting an abnormal current during charging / discharging of the battery body 20 as is well known.
It is electrically connected to the battery body 20. Further, on the circuit board 31, for example, three electrodes 32 are formed on the upper side (upper side in FIGS. 2 and 3) by plating, and the protection circuit accommodating portion 14 of the outer case 10 has An electrode window 16 is formed at a corresponding position. As a result, when the battery pack is mounted on the mobile phone, a power supply terminal (not shown) of the mobile phone contacts the electrode 32 through the electrode window 16, and the mobile phone and the battery main body 20 are connected thereto.
Are electrically connected.

The circuit board 31 has the electrodes 3
A water detection seal 33 is attached between the two. The water detection seal 33 is a well-known material having a property that the surface is discolored when water adheres, and the discolored surface is attached upward. On the other hand, the outer case 10
The observation hole 18 is located in the protection circuit housing portion 14 between the electrode windows 16 and at a position corresponding to the water detection seal 33.
The water detection seal 33 can be observed from outside the outer case 10 through the observation hole 18.

A guide ridge 19 is provided on the outer periphery of the observation hole 18 so as to form a substantially U-shape, and a protective seal 34 is located inside the guide ridge 19. The protective seal 34 is formed in a rectangular shape with a transparent plastic film having a light-transmitting property, for example, and is adhered and fixed to the outer case 10 by an adhesive (not shown) applied in a frame shape on the outer peripheral portion. The non-light-transmitting portion 34A is formed by printing black paint on the protective seal 34 so as to overlap the application region of the adhesive (see FIG. 1).

In the above configuration, if the battery pack is immersed in water due to the mobile phone being wetted by rain or dropped in water, the inside of the outer case 10 is inserted from the gap between the electrode window 16 and the electrode 32 into the inside. Water may enter. This water spreads along the surface of the circuit board 31 on which the electrodes 32 are formed, and eventually spreads on the components and circuit patterns of the protection circuit 30, corroding them and causing an electrical short circuit. May be.

However, in the present embodiment, the circuit board 31
When the water adheres to the water, the water detection seal 33 is provided very close to the electrode 32, so that the water first adheres here. As a result, the water detection seal 33 is discolored when wet with water, and then keeps its discolored state even when dried. Since this state can be observed from the outside through the observation hole 18, it is possible to accurately determine whether or not the protection circuit 30 is wet with water. In this regard, in the conventional battery pack in which the water detection seal is provided on the battery main body, even if the water that has entered from the electrode portion adheres to the protection circuit but does not adhere to the water detection seal, the intrusion of water cannot be reliably detected. Although there was a possibility, in the present embodiment, since the water detection seal 33 exists in the protection circuit 30 itself, it is possible to accurately determine whether the protection circuit 30 is flooded.

In addition, in order to improve the assembling workability,
In view of the fact that the protective seal 34 is stuck to the exterior case 10 with an adhesive, the non-light-transmitting portion 34A made of black paint is formed corresponding to the portion where the adhesive is applied, so that white irregular reflection occurs from the outside. The viable adhesive-applied portion can be hidden by the non-light-transmitting portion 34A. Thus, it is possible to prevent the visibility from being deteriorated due to the irregular reflection, to surely observe the degree of discoloration of the water detection seal 33, and it is possible to more accurately determine the inundation.

Further, since the observation hole 18 is covered with the protective seal 34, even if wet fingers touch the observation hole 18 portion or a small amount of raindrops adhere to the observation hole 18 during normal handling of the battery pack, the water detection seal is provided. No water adheres to the surface 33, and erroneous detection can be reliably prevented. Also,
The observation hole 18 is provided on the lid 12 side of the outer case 10, and the lid 12 side is a mounting surface for the mobile phone. Therefore, when the battery pack is mounted on the mobile phone,
The observation hole 18 (protective seal 34) does not appear in the appearance, and does not impair the appearance of the mobile phone.

FIGS. 4 and 5 show another embodiment of the present invention. This is different from the above-described embodiment in that the water detection seal 33 is integrated with the back surface of the protective seal 34 by bonding, and the other parts are the same. Here, a wide and shallow groove 34B is formed on the back surface of the protective seal 34, and a water detection seal 33 is adhered so as to close the groove 34B. Therefore, the water detection seal 3
A gap 36 through which water can enter is formed between the discolored surface 3 and the back surface of the protective seal 34. According to this configuration,
Water detection seal 33 and protective seal 3 when assembling the battery pack
4 can be integrally treated as one component, which is advantageous in terms of component management and assembling man-hours, and enables cost reduction.

The technical scope of the present invention is not limited by the above-described embodiments, and for example, the following ones are also included in the technical scope of the present invention. (1) In the above embodiment, an example is shown in which the present invention is applied to a battery pack that is detachably attached to a mobile phone.
It may be mounted on another electric device such as a player, a portable MD player, a digital still camera, or a digital video camera. (2) In the above embodiment, the battery body 20 is a lithium ion battery. However, the present invention is not limited to this, and another type of secondary battery such as a nickel cadmium battery or a nickel hydride battery may be used.

[Brief description of the drawings]

FIG. 1 is a partially exploded perspective view of a battery pack according to an embodiment of the present invention.

FIG. 2 is a partial cross-sectional view of the battery pack taken along line BB in FIG. 1;

FIG. 3 is a partial cross-sectional view taken along line AA of FIG. 1;

FIG. 4 is a perspective view of a water detection seal and a protection seal showing another embodiment of the present invention.

FIG. 5 is an enlarged sectional view of the same.

[Explanation of symbols]

 Reference Signs List 10 outer case 11 bottom plate 12 lid 14 protection circuit housing 16 electrode window 18 observation hole 19 guide ridge 20 battery body 30 protection circuit 31 Circuit board 32 ... Electrode 33 ... Water detection seal 34 ... Protective seal 34A ... Non-light-transmitting part 34B ... Groove

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Minoru Kobayashi 5th, Ichidandancho, Kisho-in, Minami-ku, Kyoto, Japan Inside GE Melcotec Co., Ltd. (72) Inventor Seiji Ioka 2-chome 2, Marunouchi, Chiyoda-ku, Tokyo No. 3 Mitsubishi Electric Corporation (72) Inventor Hirokazu Ishida 2-3-2 Marunouchi, Chiyoda-ku, Tokyo F-term (reference) 5H040 AA18 AA19 AS12 AY04 DD01 DD26 LL06

Claims (4)

[Claims] 1. A battery pack comprising a battery body and a protection circuit for the battery in an outer case, wherein a water detection seal that changes color when wetted with water is provided on a circuit board of the protection circuit. Wherein an observation hole is formed at a position corresponding to the water detection seal, and the observation hole is covered with a light-transmitting protective seal. 2. The circuit board according to claim 1, wherein a plurality of electrodes connected to the battery body are arranged on the circuit board, and the water detection seal is provided between the electrodes.
The battery pack described. 3. An outer peripheral portion of the protective seal is coated with an adhesive to be attached to the outer case, and a non-light-transmitting portion is formed corresponding to a region where the adhesive is applied. The battery pack according to claim 1 or 2, wherein 4. The battery pack according to claim 1, wherein the water detection seal is integrated with the protective seal with an inundation gap therebetween.