JPH08162078A - Battery pack and its manufacture - Google Patents

Abstract

PURPOSE: To provide a battery pack capable of being easily manufactured by use of widely available and inexpensive parts in which highly reliable explosion-proof property can be provided, and the internal structure can be miniaturized together with simplification, and a method for manufacturing it. CONSTITUTION: After a set battery 30 consisting of a plurality of batteries 31 and a power limiting circuit 40 having a plurality of resistors 42 on a printed board 41 are assembled together, and mounted on a case body 10, a case lid body 20 is fixed to the case body 10 to cover the set battery 30 and the power limiting circuit 40, and terminals 43a, 43b connected to the set battery 30 through the power limiting circuit 40 are opposed to the outer surface of the case body 10. An elastomer 50 is then injected through an injection hole 15 formed in the case body 10, and filled in a space S around the resistors 42 of the power limiting circuit 40 to cover the resistors 42, so that they are isolated from the outer part, and the backlash of the resistors 42 is suppressed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a battery pack which is detachably and replaceably assembled to a portable wireless device or the like and a manufacturing method thereof, and more particularly to an explosion-proof battery pack and a manufacturing method thereof.

[Prior art]

In portable radios and the like used in an environment where flammable solvents and the like are mixed, it is indispensable to suppress the generation of sparks and temperature rise that cause explosion. Composed of explosion-proof structure. Conventionally, as an explosion-proof battery pack of this type, one power limiting element such as a power winding resistor or a power metal film resistor is connected in series to a battery and housed in the housing, and the outer surface of the housing is connected. It is known that a terminal connected to a battery through a power limiting element is exposed.

[0003]

However, in the above-mentioned conventional explosion-proof battery pack, the power limiting element such as a resistor is firmly fixed to the battery or the housing to prevent rattling or the like which causes sparks. There is a problem that a fixture for fixing the power limiting element is indispensable because it must be suppressed, the internal structure becomes complicated, and the number of assembling steps during manufacturing also increases. Particularly, in the above-mentioned conventional explosion-proof battery pack, since only one power limiting element is used, usable resistors are limited to special resistors such as an axial lead type having a large size. There is a problem that it is difficult to obtain the container itself, which causes adverse effects such as delay in delivery time, causes an increase in size of the housing, and also concentrates the generated heat, and it is difficult to obtain a satisfactory heat dissipation characteristic.

On the other hand, the latter problem may be solved by connecting small power limiting elements in parallel, but when a plurality of power limiting elements are used, mutual interference must be prevented, The former problem becomes noticeable. The present invention has been made in view of the above problems, and provides a battery pack that can be simplified in internal structure, can be downsized, and has a large degree of freedom in designing a housing, and the like. The purpose of the present invention is to make it possible to manufacture this battery pack using widely distributed general-purpose components.

[0005]

In order to achieve the above object, a battery pack according to a first aspect of the invention is a power limiter having a power limiting element in a housing constructed by assembling a case body and a case lid. A battery containing a battery and a battery, the terminal of which the power limiter is connected in series to the battery is exposed to the outer surface of the housing, and the power limit of at least the inner surface of the housing and the power limiter in the housing. An elastomer was filled between the element and the elastomer to coat the power limiting element.

The battery pack according to a second aspect of the present invention is configured such that the power limiting element is formed by connecting in parallel a plurality of resistors arranged on a substrate at intervals.

Further, in the method for manufacturing a battery pack according to the invention of claim 3, the substrate on which the power limiting element is mounted is assembled to the battery, the battery assembled with the substrate is attached to the case body, and then the case is mounted. A case lid that covers the battery and the power limiting element is fixed to the main body, and then an elastomer is injected from an injection port formed in at least one of the case main body and the case lid to attach the elastomer to the power limiting element. After filling around, the injection port was closed with a plug member.

[0008]

In the battery pack according to the present invention, the elastomer is filled around the power limiting element such as a resistor,
Since this elastomer isolates the power limiting element from the outside, a highly reliable explosion-proof property is achieved, and since the elastomer suppresses rattling of the power limiting element, a fixing tool is not required to prevent rattling of the power limiting element. The internal structure can be simplified and the number of assembling steps at the time of manufacturing can be reduced.

In the battery pack according to the second aspect of the invention, since a plurality of small resistors and the like are connected in parallel,
It is possible to use a small-sized inexpensive resistor that is widely distributed, and to disperse the heat generated by these power limiters, to obtain excellent heat dissipation characteristics, and further to reduce the size of the entire battery pack.

In the battery pack manufacturing method according to the third aspect of the present invention, the assembly (manufacturing) can be performed without considering the fixing of the power limiting element, and the case body covers the battery and the power limiting element. Since the elastomer is injected and filled around the power limiting element with the case lid fixed, molding of the elastomer or the like is unnecessary and the filling operation can be easily performed.

[0011]

Embodiments of the present invention will be described below with reference to the drawings. 1 to 5 show a battery pack according to an embodiment of the present invention, FIG. 1 is an exploded perspective view, FIG. 2 is a plan view, FIG. 3 is a sectional view taken along the line AA of FIG. 2, and FIG. 2 is a sectional view taken along the line BB of FIG. 2, and FIG. 5 is an electric circuit diagram.

In FIGS. 1 to 4, 10 is a case body having a substantially rectangular flat plate shape, and 20 is a case lid body having a substantially rectangular tube shape with one surface opened. The case body 10 and the case lid body 20 are denoted by A.
It is molded by injection molding of BS resin. The case main body 10 has a fitting projection 11 formed on the inner peripheral edge thereof, and a rectangular recess 12 formed on one side of the inner surface. The recess 12 penetrates the front and back sides to form two terminal lead-out holes 13, 14 And the injection hole 15 opens. An outer surface of one side of the case lid 20 projects and a lock hole 21 is formed in the projecting portion, and a lock button 23 for fixing to a wireless device main body or the like is accommodated in the lock hole 21 by a spring 22. To be done. The case body 10 and the case lid body 20 have the opening edge portions of the case lid body 20 fitted to the fitting protrusions 11 of the case body 10 to form the assembled battery 3
0 and an output limiting circuit (output limiter) 40 are included in a battery pack housing. In FIG. 1, 19 is a plug member that closes the injection hole 15, and the injection hole 15 is closed by the plug member 19 after the injection of the elastomer, as described later.

The assembled battery 30 is composed of four rectangular parallelepiped batteries 3.
1a, b, c, d (hereinafter represented by numbers without subscripts)
And the batteries 31 are connected in series (see FIG. 5). In this battery pack 30, three batteries 31a, 31b, 31c, 31c, 31c, 31c, 31c, 31c, 31c, 31c, 31c, 31c, 31c, 31c, 31c, 31c, 31c, 31d are arranged in a plane shape, and a battery 31d is arranged on the battery 31a.
A space S accommodating the output limiting circuit 40 is defined between the batteries 31b and 31c and the case lid 20. The electrode plate 32 is formed into a plate shape from fiber, FRP, or the like, and its ends are fixed to the electrodes or the like of the adjacent batteries 31, respectively. The electrode plate 32 may be provided with a conductive foil or the like on one surface so that the batteries 30 can be electrically connected. Needless to say, the batteries 31 can be connected in parallel. It is possible, and the number of batteries 31 can be arbitrarily determined.

In the space S, the batteries 31b of the assembled battery 30,
An output limiting circuit 40 is provided on c via an insulating plate 49, and the elastomer 5 is provided around the output limiting circuit 40.
Zeros are filled. The output limiting circuit 40 includes the printed circuit board 4
Five metal film fixed resistors (output limiting element) 42 in 1
a, b, c, d, e and two terminals 43a, b (represented by numbers without subscripts as necessary) are provided,
Two portions of the conductive portion (the insulating portion is shown by hatching) are connected to the plus and minus electrodes of the assembled battery 30 by the lead members 47, respectively. The metal film resistors 42 are arranged side by side on the printed circuit board 41 with a predetermined space therebetween, and are connected in parallel with each other (see FIG. 5). The terminals 43a and 43b are
The side portions of the battery 31c are extended in parallel to the case body 10 side with a gap and are exposed to the outside through the terminal lead-out holes 13 and 14 described above. A battery 31c is provided between these terminals 43a and 43b.
A gap (for convenience, referred to as a communication passage) that communicates the injection hole 15 and the space S described above is formed in the side portion of.

The output limiting circuit 40 described above is composed of five metal film fixed resistors 42. However, the metal film fixed resistors 42 can be replaced by other winding resistors or the like. The number can also be arbitrarily set within a range of 2 or more. Further, although illustration and detailed description are omitted, it is possible to open a hole for venting air at the time of filling the elastomer 50 at a position opposite to the injection hole 15 in the space S described above. Further, the injection port 15 described above can be formed in the case lid body 20 or can be formed in both the case body 10 and the case lid body 20.

The elastomer 50 is made of a thermoplastic elastomer such as a styrene type, an olefin type or a vinyl chloride type, and is preferably made of a silicone type having excellent thermal conductivity, and preferably has a large heat capacity. Is composed of. The elastomer 50 is filled in the space S and covers the front and back of the printed circuit board 41 of the output limiting circuit 40, in particular, the metal film fixed resistor 42 thereof. As will be described later in detail, the elastomer 50 is injected from the injection hole 15 and filled in the space S via the communication passage between the terminals 43a and 43b described above.

In the figure, 18 is a lid member made of ABS resin or the like, and 27 and 28 are spacers made of Bakelite or the like.

In this embodiment, it is assembled in the following procedure. First, the output limiting circuit 40 is attached to the assembled battery 30.
Assemble and wire. That is, the printed circuit board 41 on which the metal film fixed resistor 42 of the output limiting circuit 40 is mounted.
Are mounted on the batteries 31b and 31c, and the lead member 45 is soldered to the conductive portion of the printed circuit board 41 to be connected to the assembled battery 30. At this time, the printed circuit board 41 is mounted on the battery pack 30.
It suffices to place it on the insulating plate 49, but the substrate 41 can be fixed to the assembled battery 30.

Next, the assembled battery 30 to which the output limiting circuit 40 is assembled is attached to the case body 10, and then the case lid 20 is fixed to the case body 10. That is, an adhesive is applied to the ridges 11 and the like of the case main body 20, the opening of the case lid 20 is fitted into the ridges 11 and the ridges 11 are bonded by the adhesive. Next, the elastomer 50 is injected from the injection port 15 of the case body 10. Here, the elastomer 50 injected from the injection port 15 flows into the space S through the communication path between the terminals 43a and 43b, fills the space S, and the substrate 41 of the output limiting circuit 40 and the metal film fixed resistor. 42 is coated. Then, the plug member 19 is fitted into the injection port 15 to close the injection port 15. Therefore, the elastomer 50 can be manufactured without considering molding or the like, and the manufacturing can be performed easily and with a small number of steps.

In the battery pack manufactured as described above, the five metal film fixing resistors 42 are pressed by the elastomer 50 filled in the space S to prevent mutual interference, rattling, etc. It is possible to reliably prevent the occurrence of sparks due to rattling, etc.
Further, since the metal film fixed resistor 42 is isolated from the outside by the elastomer 50, highly reliable explosion-proof property is obtained,
Further, since the metal fitting for fixing the metal film fixed resistor 42 is unnecessary, the number of parts can be reduced, the internal structure can be simplified, and the assembly is easy as described above.

In addition, since this battery pack uses five metal film fixed resistors 42 connected in parallel, the heat generated by the output limiting circuit 40 can be dispersed and excellent heat dissipation characteristics can be obtained. Further, the battery pack can be miniaturized. A large degree of freedom can be obtained in the design of the shape, and the widely distributed resistor 42 can be used, so that the delivery time can be shortened and the cost can be reduced.

[0022]

As described above, according to the first aspect of the invention, the elastomer filled around the power limiting element such as the resistor isolates the power limiting element from the outside.
A highly reliable explosion-proof property is achieved, and rattling of the power limiting element can be suppressed.A fixing tool is not required to prevent rattling of the power limiting element, and the internal structure can be simplified.
Furthermore, the effect that the number of assembling steps at the time of manufacturing can be reduced can be obtained.

According to the second aspect of the invention, since a plurality of small-sized resistors and the like are connected in parallel, a widely distributed small-sized and inexpensive resistor can be used, which shortens the delivery time and lowers the cost. Further, it is possible to disperse the heat generated by these resistors and the like, to obtain excellent heat dissipation characteristics, and further, it is possible to obtain the effect of downsizing the battery pack as a whole.

According to the third aspect of the invention, the assembly can be performed without considering the fixing of the power limiting element, and
Since the elastomer is injected and filled around the power limiting element with the lid member that covers the battery and the power limiting element fixed to the case body, molding of the elastomer is not necessary and the filling work can be performed easily, and the battery pack can be manufactured. It is possible to obtain the effect that it can be easily performed with a small number of steps.

[Brief description of drawings]

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

FIG. 2 is a plan view of the battery pack.

FIG. 3 is a sectional view taken on line AA of FIG. 2;

FIG. 4 is a sectional view taken along the line BB of FIG.

FIG. 5 is an electric circuit diagram of the battery pack.

[Explanation of symbols]

 10 Case Main Body 15 Injection Port 19 Plug Member 20 Case Lid 30 Battery Assembly 31 Battery 32 Electrode Plate 40 Output Limiting Circuit (Output Limiter) 41 Printed Circuit Board 42 Metal Film Fixing Resistor 43 Terminal 50 Elastomer S Space

Claims (3)

[Claims] 1. A power limiter having a power limiting element and a battery are housed in a housing formed by assembling a case body and a case lid, and the battery is connected to the power limiter in series. In the battery pack in which the terminals are exposed to the outer surface of the housing, an elastomer is filled in the housing between at least the inner surface of the housing and the power limiting element of the power limiter, and the power limiting element is covered with the elastomer. A battery pack characterized by the above. 2. The power pack according to claim 1, wherein the power limiter is formed by connecting in parallel a plurality of resistors arranged at intervals on a substrate. 3. A substrate on which a power limiting element is mounted is assembled to a battery, the battery on which the substrate is assembled is attached to a case body, and then a case lid for fixing the battery and the power limiting element is fixed to the case body. Then, after injecting an elastomer from an injection port formed in at least one of the case main body and the case lid to fill the elastomer around the power limiting element, the injection port is closed with a plug member. A method of manufacturing a battery pack, comprising: