Battery device

The battery apparatus according to the present invention has the structure in which a lid is engaged with a battery storage to cover a storage portion storing a battery unit via a first fixing means employing a simple structure. Further, the battery storage is formed of the frame and a closing unit engaged via a second fixing means only employing a simple structure.Furthermore, since the battery storage, or the lid, or the closing unit is formed of metal; and the thickness thereof is made thinner, the capacity of the storage portion can be increased to the extent of the reduction in the thickness, whereby the amount of electricity can be increased.

CROSS REFERENCES TO RELATED APPLICATIONS

This application claims priority to Japanese Patent Application Number JP2002-060694, filed Mar. 6, 2002 which is incorporated herein by reference.

TECHNICAL FIELD

The present invention relates to a battery apparatus used, for example, as a power source for a mobile phone unit or other electronic equipment, in which a battery unit containing an element of generating power is stored in a storage portion formed by overlapping a battery storage and a lid.

BACKGROUND OF THE INVENTION

As a first example of a battery apparatus having such structure, a battery apparatus having, for example, the structure shown inFIG. 8has been conventionally known. A battery apparatus1shown inFIG. 8includes a battery unit2having a power-generating element, a battery storage3having a storage portion5in which the battery unit2is stored, and a lid4to close the storage portion5of the battery storage3.

The battery apparatus1is used, for example, as a power source for a mobile phone unit, and the battery unit2has an arched-shape due to the limitation of the space to be stored in the mobile phone unit. As the battery unit2, for example, polymer secondary cell is employed. The battery storage3for storing the battery unit2, and the lid4are formed of synthetic resin such as polycarbonate (PC).

On the periphery of the battery storage3surrounding the storage portion5, a step portion is circumferentially provided. On the other hand, a corresponding step portion engaged with that step portion of the battery storage3is provided on the periphery of the lid4. By engaging the step portion of the lid4with that of the battery storage3, the positions of the battery storage3and the lid4are determined to each other and the battery storage3and lid4are overlapped in a predetermined state. Contacting portions of the battery storage3and the lid4are joined, for example, by bonding means such as ultrasonic deposition, and the battery storage3and the lid4are connected to be integrally formed.

Two electrode terminals2a,2bare lead out from the battery unit2and are connected to a circuit substrate6aof a control circuit6provided for controlling discharge, charge, and so on of the battery unit2. To the circuit substrate6a, there are connected a pair of terminals3a,3bprovided on the battery storage3, through which the circuit substrate is connected to the outside. Numeral7denotes an insulating board functioning as a partition to separate the battery unit2and the controlling circuit6. Further, numeral8adenotes double-faced tape for fixing the battery unit2in the lid4, and numeral8bdenotes a double-faced tape for fixing the battery unit2in the battery storage3.

However, with respect to the conventional battery apparatus1having such structure, since the battery storage3and the lid4are both formed of synthetic resin, it is difficult to meet the demand of providing a thinner battery storage3and lid4, and therefore there was a problem in which capacity of the power-generating element can not be increased in the case where the outside dimensions are unchanged.

For example, with respect to a mobile phone unit, while a smaller unit body is strongly requested, such demand as to be able to use the unit as long as possible has been extremely great. Therefore, there is a strong desire to obtain a mobile phone unit in which only the capacity of a power-generating element is made to be large enough to discharge for a long period of time without changing the outside dimensions of the battery apparatus1.

However, in the above-mentioned battery apparatus1, since the battery storage3and the lid4are both formed of synthetic resin that has problems in pliability, strength, and the like, it is difficult to reduce the thickness of the battery storage3and the lid4.

In order to solve the above problems, as shown inFIG. 9, there has been provided a battery apparatus10with an improved structure. In the battery apparatus10, only a battery storage11and a lid12are improved and no other constituents are modified. Accordingly, hereupon only the battery storage11and the lid12will be explained, and to other constituents the same numerals are given and the explanation thereof is omitted.

The battery storage11of the battery apparatus10is composed of a frame13in which a large square opening11ais provided on the lower surface portion thereof and a closing unit14which is integrally provided with the frame13to close the opening11a. Similarly, the lid12is composed of a frame15in which a large square opening12ais provided on the upper surface portion thereof and a closing unit16which is integrally provided with the frame15to close the opening12a. While the frames13and15are formed of synthetic resin, the closing units14and16are formed of metal, and by employing what is called insert molding the frames and closing units are integrally formed.

Further, inFIG. 9, a numeral9adenotes a double-face tape also functioning as an insulating tape provided between the battery unit2and the lid12. Further, a numeral9bdenotes a double-face tape also functioning as an insulating tape provided between the battery unit2and the battery storage11.

According to the battery apparatus10which includes the battery storage11and the lid12having such structure, if the outside dimensions are identical and each member has the same strength, members formed of metal can be made extremely thinner compared to those formed of synthetic resin. Accordingly, with respect to the battery storage11and the lid12, a capacity of the storage portion5can be made larger to the amount of decrease in the thickness of the closing units14and16which are formed of metal. Consequently, the thickness of the battery unit2can increase as much as the capacity of the storage portion5increases, thereby increasing the capacity of the battery unit2to obtain a larger amount of electricity.

However, in the above-mentioned improved battery apparatus10, since the insert molding is required to fabricate both the battery storage11and the lid12, it is necessary to prepare a molding die having a complicated structure, which causes problems of increasing production cost and requiring much time and work in a production process.

The present invention is made in light of the above problems and provides a battery apparatus, in which a lid that closes the end of an opening of a storage portion of a battery storage, or a closing unit that closes the bottom of the battery storage is formed to be capable of being engaged with the battery storage; means for fixing the lid to the battery storage or for fixing the closing unit to the lid is provided to firmly fix the lid to the battery storage, or to firmly fix the closing unit to the lid to be integrally formed, respectively, preventing each member from being separated; and a capacity of the storage portion is made as large as possible to increase the capacity of the battery unit and thus increase the amount of electricity.

SUMMARY OF THE INVENTION

A battery apparatus according to the present invention includes: a battery unit which contains a power-generating element, a battery storage having a storage portion in which the battery unit is stored, and a lid which closes the end of an opening of the storage portion of the battery storage, wherein a first fixing means for enabling the lid to be engaged with the battery storage and for fixing the lid to the battery storage is provided.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Hereinafter, embodiments of the present invention will be explained referring to the attached drawings.

As shown inFIG. 1, a battery apparatus20showing an embodiment of the present invention includes: a battery unit21in which a power-generating element is contained, a frame22having a storage portion29in which the battery unit21is stored, an upper case23that is a specific example of a lid which closes the upper surface, that is, a one surface side of the storage portion29of the frame22, a lower case24that is a specific example of a closing unit which closes the lower surface, that is, the other surface side of the storage portion29of the frame22, upper and lower insulating sheets25and26, a control circuit27, an insulating plate28, and the likes.

As the battery unit21, for example, a nonaqueous electrolytic secondary battery (such as a polymer secondary battery, lithium ion secondary battery, or the like) can be applied. There is provided the battery unit21in which, for example, through a separating member formed of polymer film a positive electrode and a positive collector are lapped over a negative electrode and a negative collector to be contained in a covering member formed of a laminated film of aluminum foil and plastic, and in vacuum the periphery of the covering member is subjected to the thermal deposition to be sealed. From the covering member, an electrode terminal21aconnected to the positive collector and an electrode terminal21bconnected to the negative collector are lead out.

The battery unit21has a rectangular-shaped plane, on a side in a longitudinal direction of which a U-shaped circuit storage portion30formed by utilizing a part of the covering member subjected to the thermal deposition is provided. In the circuit storage portion30, a control circuit27is stored in a space divided by an insulating plate28formed of an insulative plastic sheet or the like. The control circuit27includes a circuit substrate31provided with a predetermined circuit pattern, and to the circuit substrate31the terminals21aand21bof positive and negative electrodes are connected. Further, on both the surfaces of the circuit substrate31various kinds of electronic components32are mounted so that the charge, discharge and so on of the battery unit21are controlled for the safety and to prevent irreversible breakdown of the electrodes caused by overcharge and over discharge.

The frame22is formed of a frame-shaped member capable of completely containing the battery unit21, in which the storage portion29is composed of a square-shaped opening provided through the top and bottom surfaces. Specifically, the frame22includes long side portions22a,22bprovided parallel to oppose each other, and short side portions22-c,22dprovided parallel to oppose each other extending in the direction intersecting the long sides. The frame22is shaped like an arch which is curved corresponding to the shape of the battery unit21with the upper surface thereof protruding convexly and the lower surface thereof being bent concavely.

The upper case23is dome-shaped, whose upper surface is curved like an arch corresponding to the shape of the upper surface of the frame22. The upper case23has an upper surface portion23athat closes one end of the opening, which constitutes one surface of the storage portion29of the frame22, and long side surface portions23b,23cand short side surface portions23d,23ethat continue to the four sides of the upper surface portion23a, respectively. Further, on respective side surface portions23bto23eof the upper case23an appropriate number of fixing pieces33are provided. In this embodiment, there are provided four fixing pieces33on each of the long side surface portions23b,23c, one fixing piece33on one of the short side surface portions, that is, the short side surface portion23d, and two fixing pieces33on the other short side surface portion23e. Furthermore, in each of the fixing pieces33there is provided an oblong-shaped engaging hole33awhich represents a specific example of a concave portion.

The lower case24has a convexly curved lower surface corresponding to the shape of the lower surface of the frame22. The lower case24has a lower surface portion24athat closes the other end of the opening, which constitutes another surface of the storage portion29of the frame22, and long side surface portions24b,24cand short side surface portions24d,24ewhich continue to four sides of the lower surface portion24a, respectively. Further, on respective side surface portions24bto24eof the lower case24an appropriate number of fixing pieces34are provided. In this embodiment, there are provided three fixing pieces34on each of the long side surface portions24b,24c, two fixing pieces34are provided on one of the short side surface portions, that is, the short side surface portion24d, and one fixing piece34on the other short side surface portion24eof the lower case24. Furthermore, in each of the fixing pieces34there is provided an oblong-shaped engaging hole34awhich represents a specific example of a concave portion.

In addition, on the inside surfaces of the four sides of the frame22, that is, long side portions22a,22band short side portions22c,22d, engaging hooks35,36representing a specific example of a convex portion that each constitute first fixing means and second fixing means by being combined with the engaging hole33ain the fixing piece33of the upper case23and being combined with the engaging hole34ain the fixing piece34of the lower case24, respectively, and peaked portions37,38supporting the base portions of respective fixing pieces33,34which are engaged with those engaging hooks35,36are provided in number equal to that of the corresponding fixing pieces33,34.

In a plurality of the engaging hooks35,36, the engaging hooks35are to fix the fixing pieces33of the upper case23, and, as shown inFIG. 5, have a hook-shape in which the upper surface thereof is inclined corresponding to the upper fixing piece33that is inserted downward, and the lower surface thereof is plane. Above the upper engaging hooks35, upper peaked portions37protruding like overhangs are each provided. Further, in each of the upper peaked portions37there is provided a slit37athrough which the upper fixing portion33is made to pass.

On the other hand, the other engaging hooks36are to fix the fixing pieces34of the lower case24, and, as shown inFIG. 4, have a hook-shape in which the lower surface thereof is inclined corresponding to the lower fixing piece34that is inserted upward, and the upper surface thereof is plane. Under the lower engaging hooks36lower peaked portions38of protruding edges are each provided. Further, in each of the lower peaked portions38there is provided a slit38athrough which the lower fixing portion34is made to pass.

Specifically, in the two long side portions22a,22bof the frame22there are provided four engaging hooks35and four peaked portions37corresponding to the fixing pieces33of the upper case23, and three engaging hooks36and three peaked portions38corresponding to the fixing pieces34of the lower case24. Further, in one of the short side portions, that is, the short side portion22cof the frame22there are provided one engaging hook35and one peaked portion37corresponding to the fixing piece33of the upper case23, and two engaging hooks36and two peaked portions38corresponding to the fixing pieces34of the lower case24are provided. Then, in the other short side portion22dof the frame22there are provided two engaging hooks35and two peaked portions37corresponding to the fixing pieces33of the upper case23, and one engaging hook36and one peaked portion38corresponding to the fixing pieces34of the lower case24.

As shown inFIG. 4, the upper engaging hooks35and lower engaging hooks36are set at an approximately equal height, and are alternately disposed. Accordingly, when the upper case23and lower case24are attached to the frame22including such upper and lower engaging hooks35,37, the upper fixing pieces33and the lower fixing pieces34are joined to be engaged such that the pieces are meshed with each other, and disposed alternately.

Further, on both sides of the short side portion22dof the frame22there are integrally formed a pair of supporting portions40,41which hold both ends of the circuit substrate31of the above-mentioned control circuit27. As shown inFIGS. 2 and 3, the pair of supporting portions40,41is engaged with a pair of holes bored on the circuit substrate31to support the both ends of the circuit substrate31, so that the circuit substrate31is disposed to divide the circuit storage portion30of the battery unit21into upper and lower parts. As a result, an appropriate space is provided above and under the circuit substrate31, so that on both surfaces of the circuit substrate31desired electronic components can be mounted.

Therefore, according to the above embodiment, compared to the case where electronic components are mounted on only one surface of a circuit substrate, approximately twice the number of electronic components can be mounted on the circuit substrate. Accordingly, the circuit substrate is efficiently used, and larger number of mechanical structures can be mounted to improve a safety circuit and so on.

Although as the material for the frame22having the above-described structure, for example, polycarbonate (PC) can be employed, needless to say other engineering plastics can also be used as well as metal and other materials than plastics. Further, though stainless steel (such as SUS304 or the like), for example, is preferable as the material for the upper case23and lower case24, needless to say other metals can also be applied.

One of the insulating sheets, that is, the insulating sheet25is provided between the battery unit21and the upper case23to ensure the insulation; and though the sheet is preferably made of polyester, other sheet-shaped insulating members such as other plastics, paper, and other materials can also be applied. On the other hand, the other insulating sheet26provided between the battery unit21and the lower case24has a function of not only ensuring the insulation but also fixing the battery unit21. Therefore, on a surface of the lower insulating sheet26an adhesive layer is provided by, for example, coating the surface with adhesive to bond the adhesive layer with the battery unit21. By means of the lower insulating sheet26, the movement of the battery unit21can be restrained or prevented, and the battery unit is prevented from being lopsided.

The battery apparatus20having the above structure can be manufactured, for example, through the following assembly process. First, the lower case24is attached to the frame22. In this embodiment, the lower surface of the frame22is opposed to the side of the lower case24, from which the fixing pieces34are protruded, and a number of fixing pieces34are inserted upward into the storage portion29composed of the opening of the frame22. Specifically, each of the fixing pieces34is individually inserted and pressed into the slit38aof the corresponding lower peaked portion38provided on the lower surface side of the frame22. Thus, with respect to each fixing piece34, the tip thereof slides along a slope portion to climb over the lower engaging hook36, and the lower engaging hook36enters the engaging hole34aprovided in each fixing piece34.

As a result, as shown inFIG. 4, the engaging holes34aof the lower fixing pieces34and the lower engaging hooks36of the frame22are engaged to form the second fixing means, through which the lower case24is fixed to the frame22and assembled. In the storage portion29of the frame22, whose lower surface is closed by the lower case24, there is stored the battery unit21to which the control circuit27and the insulating plate28are attached in advance. At that time, the lower insulating sheet26is bonded with the lower surface of the battery unit21to be integrally provided. Then, on the upper surface of the battery unit21the upper insulating sheet25is disposed.

Next, the upper case23is attached to the frame22. In this embodiment, the storage portion29of the frame22is opposed to the side of the upper case23, from which the fixing pieces33are protruded. Then, each of the fixing pieces33of the upper case23is individually inserted and pressed into the slit37aof the corresponding upper peaked portion37provided on the upper surface side of the frame22. Thus, with respect to each fixing piece33, the tip thereof slides along a slope portion to climb over the upper engaging hook35, and the upper engaging hook35enters the engaging hole33aprovided in each fixing piece33.

As a result, as shown inFIGS. 4 and 5, the engaging holes33aof the upper fixing pieces33and the upper engaging hooks35of the frame22are engaged to form the first fixing means, through which the upper case23is fixed to the frame22and assembled. Accordingly, the upper surface of the storage portion29of the frame22is closed by the upper case23, thereby completing the assembly process of the battery apparatus20.

According to the battery apparatus20, after the positions of the upper case23and the lower case24are determined with respect to the frame22, respective cases23and24are pressed toward the frame22side, so that the upper case23and the lower case24can be fixed to the frame22easily and rapidly. Further, when the upper case23and the lower case24are once attached, the first and second fixing means, through which both the cases are respectively fixed, are formed between each of the cases and the frame22, and since each of the engaging hooks35and36serves as a stopper for preventing falling-off, there is no possibility that the upper case23and the lower case24disengage from the frame22, thereby enabling the original assembled state to be maintained.

Further, since the upper case23and the lower case24are formed of metal, particularly formed of stainless steel, while the strength of each case is maintained to a predetermined degree, the thickness thereof can be made as thin as possible. Therefore, a capacity of the storage portion29can be increased to the extent of the decrease in thickness of each case. Accordingly, a capacity of the battery unit21can be increased corresponding to the increase in the capacity of the storage portion29, whereby the amount of electricity such as generated, charged and the like of the battery unit21can be increased.

FIGS. 6 and 7show another embodiment of the above-described first and second fixing means. In this embodiment, while upper and lower engaging hooks35,36, and the engaging holes33a,34aprovided in the upper and lower fixing pieces33,34of the above-described first embodiment are not provided, in each of the fixing pieces33,34of the upper case23and the lower case24there are provided projections43,44representing a second embodiment of the convex portions constituting one member of the fixing means, and the concave portions, to which the above projections are engaged, are provided by using the inside surface of the peaked portions37,38.

In the fixing pieces33,34of the upper case23and lower case24, the projections43,44are respectively formed by cutting parts of the fixing pieces33,34to the inside. As shown inFIG. 7, in the upper fixing piece33of the upper case23there is provided a cut-out portion in which three other sides than the end side are cut out in a U-shape, and the free end of the cut-out portion is bent toward the inside, thereby forming each of the projections43,44having an appropriate resilience. Since the other structure is the same as the above-described embodiment, the same numerals are given to the corresponding parts and the explanation thereof will be omitted.

The second embodiment of the battery apparatus20having such structure can be manufactured similarly to the first embodiment. Specifically, since the upper case23and the lower case24are sequentially assembled with respect to the frame22in a similar order, the assembly can be executed easily and rapidly. In this embodiment, for example, when the fixing piece33of the upper case23(the lower case24in similar manner) is inserted through the slit37aof the upper peaked portion37of the frame22, the projection43(the projection44in similar manner) is resiliently deformed with its own resilience and returns to the original shape after passing through the upper peaked portion37.

According to the above structure, as shown in enlarged scale inFIG. 7, the tip of the projection43is engaged with the inside surface of the upper peaked portion37. Accordingly, the upper case23is firmly fixed to the frame22and is prevented from being disengaged. Similar effectiveness to that of the above-described first embodiment is obtained when the upper case23and lower case24having such fixing means are employed, and therefore the amount of electricity of the battery unit21can be increased.

Having described above, the present invention is not limited to the aforementioned embodiments, and in the above embodiments, though, for example, there was explained an example in which the second battery having a cross section of the arched shape is employed, needless to say batteries having other cross sections such as a rectangular shape, an elliptic (oval shape) shape and other appropriate shapes can be applied. Further, although as the battery unit an example of a polymer secondary battery in which power-generating element is contained and sealed in an aluminum laminated film is applied to the above embodiment, a secondary battery in other shapes and structures can also be applied.

Furthermore, though in the above-described embodiments there was explained an example in which engaging hooks35,36having a cross section of a triangle shape are employed as the convex portion, other shapes such as a semi-circle, hemi-sphere, conical shape and so on can also be employed. Moreover, the frame can also be formed with metal similar to the upper and lower cases, and can be formed such that the fixing pieces are also provided on the frame with a convex portion being provided in one of the fixing pieces and with a concave portion being provided in the other fixing pieces.

Furthermore, in the above embodiments, though the frame22and the lower case24are formed of separate members and the lower case24is integrally assembled with the frame22, it is also possible to originally provide the frame and lower case using a single member and only the upper case is subsequently attached.

Accordingly, the present invention can be variously modified without departing from the gist thereof.