JP2004362873A

JP2004362873A - Method of manufacturing battery pack

Info

Publication number: JP2004362873A
Application number: JP2003157997A
Authority: JP
Inventors: Takashi Sumida; 孝志隅田; Tatsuya Kamata; 龍也鎌田; Koichi Ozaki; 康一尾崎; Yasuaki Wakizaka; 恭明脇阪; Yoshitaka Matsuda; 喜隆松田
Original assignee: Hitachi Maxell Ltd
Current assignee: Maxell Holdings Ltd
Priority date: 2003-06-03
Filing date: 2003-06-03
Publication date: 2004-12-24
Anticipated expiration: 2023-06-03
Also published as: JP4349514B2

Abstract

<P>PROBLEM TO BE SOLVED: To surely prevent an external output terminal from being sealed by a resin mold, in a method of manufacturing a battery pack in which electrical components are integrally formed on the peripheral surface of a unit cell with the resin mold. <P>SOLUTION: In the cavity 26 of dies 24, 25 for forming the resin mold 2, an intermediate assembly 19, in which the electrical components are temporarily fitted to the unit cell 1, is set so as to be movable forward. When molten resin is injected into the cavity 26, the intermediate assembly 19 is pushed to move forward by injection pressure of the molten resin, and the resin mold 2 is formed while the outsides of the front faces of the external output terminals 3, 4 are sealed by an inner wall face of the cavity 26. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

【０００１】
【発明の属する技術分野】
本発明は、角箱状の素電池と、この素電池の外周側面に付設され、素電池の前面側に配置される外部出力端子を含む電装品と、素電池に電装品を一体化する樹脂モールドとからなる電池パックの製造方法に関する。
【０００２】
【従来の技術】
特許文献１では、素電池に前記電装品が仮組み付設された中間組立品を金型のキャビティにセットし、キャビティに溶融樹脂を注入して樹脂モールドを成形し、樹脂モールドで素電池と電装品とを一体化した電池パックを製造することが開示されている。そこでは、金型のキャビティに臨む内壁面に、電装品の外部出力端子に突き当たる突部を設け、樹脂モールドを成形したとき、該突部で外部出力端子が外部に臨む窓口を形成している。
【０００３】
【特許文献１】
特開２００２−１３４０７７号公報（段落番号００２１−００２２、図３）
【特許文献２】
特開２００３−８６１５９号公報（段落番号００６６、図１５）
【０００４】
【発明が解決しようとする課題】
金型のキャビティに中間組立品をセットする際に、キャビティの内壁面と中間組立品との間には、溶融樹脂が流れて樹脂モールドを成形するための隙間を要するため、キャビティには中間組立品が位置決めピンで支持されることになる。一方で金型内への中間組立品の装着の容易化を図る必要がある。そのため、キャビティにセットした状態において、中間組立品に融通ガタがあり、溶融樹脂の注入時にキャビティ内で中間組立品がズレ動き、前記外部出力端子の前面外側に溶融樹脂が回り込んで目塞ぎするおそれがある。これを防止するために、キャビティに中間組立品をガチッと位置決め固定すると、金型への中間組立品の装着作業、および金型からの製品電池パックの取り出しが困難なものになり、ここに問題があった。
【０００５】
そこで本発明の目的は、成形金型のキャビティに先の中間組立品を遊動ガタを以て容易に装着できる電池パックの製造方法を提供することにある。
【０００６】
そのうえで、本発明の目的は、樹脂モールドの成形時に、前記電装品の外部出力端子の前面外側が樹脂モールドで覆われることを確実に防止できる電池パックの製造方法を得るにある。
【０００７】
【課題を解決するための手段】
本発明は、図１に示すごとく角箱状の素電池１と、この素電池１の外周側面に付設され、素電池１の前面側に配置される外部出力端子３・４を含む電装品と、素電池１に電装品を一体化する樹脂モールド２とからなる電池パックの製造方法において、図４および図５に示すごとく樹脂モールド２を成形するための金型２４・２５のキャビティ２６に、素電池１に電装品が仮組み付設された中間組立品１９をセットし、キャビティ２６に溶融樹脂を注入する際に、溶融樹脂の注入圧で中間組立品１９を前方に押圧し、キャビティ２６の内壁面で外部出力端子３・４の前面外側をここに前記溶融樹脂が回り込まないように塞いだ状態で樹脂モールド２を成形するようにしたことを特徴とする。ここでは、溶融樹脂の注入圧で中間組立品１９を動かすことなく前方に押し付ける場合と、中間組立品１９を前方に押し動かす場合とが含まれる。
【０００８】
前記キャビティ２６に溶融樹脂を注入するために、金型２４・２５に設けるべき樹脂注入ゲート２７は、溶融樹脂の注入圧で中間組立品１９を前方へ押し動かし可能な位置にあればよく、典型的には素電池１の後側面に臨むよう位置設定することができる。樹脂注入ゲート２７の数は任意に選べる。
【０００９】
前記樹脂モールド２は、図１に示すごとく素電池１の外周側面の全周にわたって成形することができるし、図１１に示すごとく素電池１の外周側面のうち前後側面と左右の一方の横側面とにわたって成形されていてもよい。もちろん、素電池の上下面を含めてこれの全体をスッポリと樹脂モールド２で被覆してもよい。
【００１０】
前記電装品は、図２に示すごとく前記外部出力端子３・４の前面に前記溶融樹脂が回り込むのを防ぐための保護カバー２０を含んでおり、前記キャビティ２６に溶融樹脂を注入したときに、保護カバー２０の外側前面をキャビティ２６の内壁面に密着状に押し付けることができる。この保護カバー２０には、外部出力端子３・４に対応する窓口２１・２２を設けておくことになる。
【００１１】
【発明の作用効果】
本発明方法によれば、金型のキャビティに中間組立品が前方への移動を許す融通ガタを以てセットされる。樹脂注入ゲートからキャビティに溶融樹脂を注入すると、溶融樹脂の注入圧で金型内の中間組立品を前方へ押圧する。これで電装品の外部出力端子がキャビティの内壁面で塞がれるので、外部出力端子が樹脂モールドで覆われることを確実に防止できる。金型のキャビティには中間組立品を融通ガタを以て位置決めセットすればよいので、金型内への中間組立品の装着、および金型からの製品電池パックの取り出しも容易に行える。
【００１２】
【発明の実施の形態】
図１ないし図３は本発明が対象とする電池パックＰを示しており、扁平角箱状の素電池１と、この素電池１の外周側面に付設される電装品と、素電池１に電装品を一体化する樹脂モールド２とからなる。ここでは素電池１の前面において、電装品に含まれる外部出力端子３・４を外部に臨むよう設けた点が注目されるべきである。
【００１３】
素電池１は、上下面が実質的に平坦面に形成され、上下厚み寸法が小さくて前後方向に長い長方形の扁平角箱状に仕上がっており、素電池１の外周側面に電装品が配されている。樹脂モールド２は、前記電装品と素電池１の上下面を除く外周側面とを覆っている。樹脂モールド２は、ポリアミド樹脂、スチレン系エラストマ樹脂およびエチレン・酢酸ビニル（ＥＶＡ）系やポリウレタン（ＰＵＲ）系のホットメルト樹脂などで成形される。
【００１４】
図２において素電池１は、外装缶５の内部に電極体と電解液とを封入した充放電が可能な二次電池、例えばリチウムイオン電池からなり、外装缶５の前面を塞ぐ封口板６の中央に正極端子７を備えている。外装缶５はニッケル板やアルミニウム板などを深絞り加工して形成してあり、それ自体が負極側の出力端子を兼ねる。前記電極体はＬｉＣｏＯ_２を活物質とする正極シートと、黒鉛を活物質とする負極シートとをセパレータを挟んで渦巻状に巻回し、全体を偏平に押し潰して形成してある。
【００１５】
電装品は、素電池１の前面側に配置される保護回路モジュール９と、素電池１の後面側に配置されるポリスイッチ１０と、これら両者９・１０、および先の正極端子７と保護回路モジュール９とをそれぞれ接続する長短２種のリード線１１・１２とを有する。
【００１６】
保護回路モジュール９は、素電池１の充放電電流を制御する保護回路が埋設された左右横長のプラスチック成形品からなり、左右端から後ろ向きに帯状の接続リード１３・１４がそれぞれ導出されている。先の保護回路は素電池１の過放電や過充電を防止する。保護回路モジュール９の前面外側には、正極側の外部出力端子３と、負極側の外部出力端子４とが配設されている。
【００１７】
ポリスイッチ１０は、素電池１の温度が設定値を越える場合に素電池１の電流を遮断するために設けてあり、その一端に接続リード１７を有する。保護回路モジュール９およびポリスイッチ１０の上下厚み寸法は、素電池１の厚み寸法よりわずかに小さく設定してある。リード線１１・１２および接続リード１３・１４・１７は、それぞれ銅、あるいはアルミニウムなどの導電性金属の薄シートを帯状に切断して形成してあり、その上下幅寸法は保護回路モジュール９の上下厚み寸法より小さく設定してある。
【００１８】
素電池１の外周側面に前記電装品を仮組み付設して、図３の中間組立品１９を得る。電装品は、別に保護カバー２０を備えており、この保護カバー２０は保護回路モジュール９の前面外側に装着される。詳しくは、保護回路モジュール９の左右両端の接続リード１３・１４に、左側の短いリード線１２と右側の長いリード線１１とをそれぞれスポット溶接し、さらに長いリード線１１の後端にポリスイッチ１０の接続リード１７をスポット溶接して、電装品をひとつながりにする。
【００１９】
次に、短いリード線１２を封口板６に絶縁性の両面テープを介して貼り付けたのち、短いリード線１２を正極端子７にスポット溶接する。同様に、長いリード線１１を絶縁性の両面テープを介して素電池１の左横側面に貼り付け、さらにポリスイッチ１０を素電池１の後側面に絶縁性の両面テープを介して貼り付け、その貼着面を外装缶５にスポット溶接する。
【００２０】
保護カバー２０は左右方向に長い帯板状のプラスチック成形品からなり、図２に示すごとく、保護回路モジュール９の正負の外部出力端子３・４に対応する窓口２１・２２を貫通状に設けてある。外部出力端子３・４が各窓口２１・２２に嵌り込む状態で、保護カバー２０を保護回路モジュール９の外側前面に貼り付けることにより中間組立品１９をつくる。
【００２１】
（実施例１）図４および図５は中間組立品１９に樹脂モールド２を成形する金型の実施例１を示す。この成形金型は、第１金型（固定金型）２４と、第２金型（可動金型）２５とを含み、両金型２４・２５の内部に形成したキャビティ２６に素電池１を位置決め装着したのち、キャビティ２６に樹脂注入ゲート２７から溶融樹脂を注入する。成形金型には、溶融樹脂が供給されるスプルー２８と、このスプルー２８と樹脂注入ゲート２７とを接続するランナ２９とが設けられており、溶融樹脂はスプルー２８、ランナ２９、樹脂注入ゲート２７を介してキャビティ２６に流れる。
【００２２】
樹脂注入ゲート２７は、キャビティ２６にセットした素電池１の後側面の中央に対向する位置に配されている。樹脂注入ゲート２７からキャビティ２６内への溶融樹脂の注入圧力は、注入速度の点からは高い方がよいが、過度に高いと素電池１の破損を招くため、１〜１０ＭＰａ、より好ましくは、１〜５ＭＰａの範囲に設定する。前記溶融樹脂の温度は２００℃程度に設定する。
【００２３】
第１金型２４のキャビティ２６に中間組立品１９を装着した状態においては、図４に示すごとく保護カバー２０の前方外面がキャビティ２６の内壁面の前面部分に近接対向している。この際、素電池１は、キャビティ２６内に設けたピン３０で左右横側面および後側面が位置決めされるが、ピン３０と素電池１との間に僅かな隙間が存在し、また保護カバー２０の外側前面とこれに対向するキャビティ２６の内壁面との間にもわずかに隙間が存在している。
【００２４】
樹脂注入ゲート２７から溶融樹脂を素電池１の後ろ側に注入すると、溶融樹脂の注入圧力で中間組立品１９の全体が前方に向けて押され、場合によっては押し動かされる。これで保護カバー２０の外側前面がキャビティ２６の内壁面に密着状に押し付けられて、中間組立品１９がキャビティ２６内において遊動不能に位置決め保持される。この状態において、溶融樹脂は素電池１の後側方の隙間から左右側方の隙間に流れ込み、溶融樹脂の一部が最終的に保護カバー２０の左右端部の外側にまで回り込む。
【００２５】
保護カバー２０の外側前面はキャビティ２６の内壁面に密着しているので、キャビティ２６に中間組立品１９を装着した際に、保護カバー２０の前面とキャビティ２６の内壁面との間に隙間が存在していても、保護カバー２０の窓口２１・２２まわりにまでは溶融樹脂が入り込まない。従って、保護回路モジュール９の正負の外部出力端子３・４を露出させる窓口２１・２２が溶融樹脂すなわち樹脂モールド２で塞がれることを確実に防止できる。
【００２６】
溶融樹脂が固化したのち、第２金型２５を第１金型２４から分離し、さらに素電池１を第２金型２５から突き出し操作することにより、素電池１の外周側面に電装品が樹脂モールド２で一体化された図１の製品電池パックＰを得た。
【００２７】
（実施例２）図６ないし図８は実施例１の保護カバー２０を省略した本発明の実施例２を示しており、キャビティ２６の内壁面に、中間組立品１９の外部出力端子３・４の前面外側を直接に受ける突部３１・３１が形成されている。具体的には該当の突部３１・３１が金型２４・２５に出退自在に設けた中子で構成されている。
【００２８】
この実施例２では、樹脂注入ゲート２７から溶融樹脂が素電池１の後ろ側に注入されると、溶融樹脂の注入圧力で中間組立品１９の全体を前方側に押し動かし、正負の外部出力端子３・４の外側前面が突部３１・３１の突端面に密着状に押し付けられ、この状態で溶融樹脂がキャビティ２６に充填されて樹脂モールド２が成形される。保護回路モジュール９の前面とこれに対向するキャビティ２６の内壁面との間にも溶融樹脂が回り込み、金型から取り出した製品電池パックＰには、図８に示すごとく前記突部３１・３１が存在していた部位に外部出力端子３・４が外部に臨む窓口が形成されたものとなる。なお、その他の点は実施例１と同じであるので、同じ部材には同じ符号を付してその説明を省略する。
【００２９】
（実施例３）図９は本発明の実施例３を示す。この実施例３の金型では、実施例１のゲート（第１ゲート）２７に加え、更に素電池１の左右横側方に臨む第２ゲート３４・３４をそれぞれ配置する。
【００３０】
第２ゲート３４・３４は、左右の第２ランナ３５・３５を介して実施例１のランナ（第１ランナ）２９に通じており、溶融樹脂はスプルー２８、第１ランナ２９および第２ランナ３５を介して各第２ゲート３４へも流れる。
【００３１】
実施例３では、スプルー２８からの溶融樹脂が第１ゲート２７へ到達した時点において、各第２ゲート３４へはまだ到達していない。従って、先に第１ゲート２７から素電池１の後ろ側に溶融樹脂が注入され、この注入圧力で素電池１が前方に向けて押される。これにより、先の実施例１と同じ要領で保護カバー２０の外側前面がキャビティ２６の前壁に密着状に押し付けられる。この状態において、溶融樹脂は、素電池１の後方の隙間から左右側方の隙間に流れ込むとともに、各第２ゲート３４からも素電池１の左右側方の隙間に流れ込む。
【００３２】
実施例３では、左右に第２ゲート３４・３４を配置した分だけ、溶融樹脂が素電池１の左右横側方へ迅速、かつバランスよく流入し、成形精度および成形サイクルを高めることができる。その他の構成は実施例１と同じであるから同一部材には同一符号を付してその説明を省略する。
【００３３】
（実施例４）図１０および図１１は本発明の実施例４を示しており、樹脂モールド２が素電池１の外周側面のうち、前後側面および右横側面を覆うコ字状に成形されている。この場合の樹脂注入ゲート２７は、素電池１の右横側面に臨むよう配置する。ここでの樹脂注入ゲート２７は、素電池１の後方側への距離が素電池１の前方側への距離よりも短くなる位置に設定する。他は実施例１と同じであるので、同じ部材に同じ符号を付して説明を省略する。
【００３４】
実施例４では、樹脂注入ゲート２７からの溶融樹脂は素電池１の後ろ側と前側とに分かれて流入する。この際、溶融樹脂は先に素電池１の後ろ側に到達し、この際の注入圧力で中間組立品１９を前方側に向けて押し動かす。これにより、保護カバー２０の外側前面がキャビティ２６の前壁に密着状に押し付けられる。この状態において、更なる溶融樹脂が、遅れて素電池１の前側方にも流れて素電池１の前後および右側方を覆うことになる。これによれば、樹脂注入ゲート２７からの溶融樹脂が、素電池１の後ろ側と前側とに迅速に行き渡って、成形サイクルの短縮化を図れる。
【００３５】
先の保護回路は実施例で説明した機能を持つものに限定されず、電池パックの用途に応じて必要な回路に構成することができる。例えばリード線１１・１２は、線状の導線であってもよい。
【図面の簡単な説明】
【図１】電池パックの斜視図
【図２】素電池と電装品との分解斜視図
【図３】中間組立品の斜視図
【図４】実施例１の金型構造を示す横断平面図
【図５】実施例１の金型構造を示す縦断側面図
【図６】実施例２の金型構造を示す要部の横断平面図
【図７】実施例２の金型構造を示す要部の縦断側面図
【図８】実施例２の電池パックの斜視図
【図９】実施例３の金型構造を示す横断平面図
【図１０】実施例４の金型構造を示す横断平面図
【図１１】実施例４の電池パックの斜視図
【符号の説明】
１素電池
２樹脂モールド
３正極側の外部出力端子
４負極側の外部出力端子
９保護回路モジュール
１９中間組立品
２０保護カバー
２１・２２窓口
２４第１金型
２５第２金型
２６キャビティ
２７樹脂注入ゲート[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention provides a square box-shaped unit cell, an electrical component attached to an outer peripheral side surface of the unit cell, and an external component including an external output terminal arranged on a front side of the unit cell, and a resin for integrating the electrical component with the unit cell. The present invention relates to a method for manufacturing a battery pack including a mold.
[0002]
[Prior art]
In Patent Document 1, an intermediate assembly in which the above-mentioned electrical components are temporarily assembled in a unit cell is set in a cavity of a mold, and a molten resin is injected into the cavity to form a resin mold. It is disclosed to manufacture a battery pack integrated with a product. There, on the inner wall surface facing the cavity of the mold, a projection is provided which abuts the external output terminal of the electrical component, and when the resin mold is molded, the projection forms a window where the external output terminal faces the outside. .
[0003]
[Patent Document 1]
JP-A-2002-134077 (Paragraph Nos. 0021-0022, FIG. 3)
[Patent Document 2]
JP-A-2003-86159 (paragraph number 0066, FIG. 15)
[0004]
[Problems to be solved by the invention]
When the intermediate assembly is set in the cavity of the mold, a gap is required between the inner wall surface of the cavity and the intermediate assembly to allow the molten resin to flow and form a resin mold. The product will be supported by the positioning pins. On the other hand, it is necessary to facilitate mounting of the intermediate assembly into the mold. Therefore, when the intermediate assembly is set in the cavity, there is a backlash in the intermediate assembly, the intermediate assembly shifts in the cavity when the molten resin is injected, and the molten resin wraps around the front outside of the external output terminal and plugs. There is a risk. If the intermediate assembly is positioned and fixed in the cavity to prevent this, the work of mounting the intermediate assembly into the mold and removing the product battery pack from the mold becomes difficult. was there.
[0005]
Therefore, an object of the present invention is to provide a method of manufacturing a battery pack in which the intermediate assembly can be easily mounted with a loose play in a cavity of a molding die.
[0006]
In addition, an object of the present invention is to provide a method for manufacturing a battery pack that can reliably prevent the outside of the front surface of the external output terminal of the electrical component from being covered with the resin mold when the resin mold is molded.
[0007]
[Means for Solving the Problems]
The present invention relates to an electrical component including a rectangular box-shaped unit cell 1 as shown in FIG. 1 and external output terminals 3 and 4 attached to the outer peripheral side surface of the unit cell 1 and arranged on the front side of the unit cell 1. In a method for manufacturing a battery pack comprising a resin mold 2 for integrating electric components with the unit cell 1, a cavity 26 of a mold 24, 25 for molding the resin mold 2 as shown in FIGS. The intermediate assembly 19 in which the electrical components are temporarily assembled is set in the unit cell 1, and when the molten resin is injected into the cavity 26, the intermediate assembly 19 is pressed forward by the injection pressure of the molten resin, and It is characterized in that the resin mold 2 is molded in a state in which the outside of the front surfaces of the external output terminals 3 and 4 is closed on the inner wall surface so that the molten resin does not flow around here. Here, a case where the intermediate assembly 19 is pressed forward without moving by the injection pressure of the molten resin and a case where the intermediate assembly 19 is pushed forward are included.
[0008]
In order to inject the molten resin into the cavity 26, the resin injection gate 27 to be provided in the molds 24 and 25 only needs to be at a position where the intermediate assembly 19 can be pushed forward by the injection pressure of the molten resin. Specifically, the position can be set so as to face the rear side surface of the unit cell 1. The number of the resin injection gates 27 can be arbitrarily selected.
[0009]
The resin mold 2 can be formed over the entire outer peripheral side surface of the unit cell 1 as shown in FIG. 1, or as shown in FIG. And may be formed over. Of course, the whole of the unit, including the upper and lower surfaces of the unit cell, may be covered with the resin mold and the resin mold 2.
[0010]
The electrical component includes a protective cover 20 for preventing the molten resin from flowing around the front surfaces of the external output terminals 3 and 4 as shown in FIG. 2, and when the molten resin is injected into the cavity 26, The outer front surface of the protective cover 20 can be pressed in close contact with the inner wall surface of the cavity 26. In the protective cover 20, windows 21 and 22 corresponding to the external output terminals 3 and 4 are provided.
[0011]
Effects of the Invention
According to the method of the present invention, the intermediate assembly is set in the mold cavity with a flexible play that allows forward movement. When the molten resin is injected into the cavity from the resin injection gate, the intermediate assembly in the mold is pressed forward by the injection pressure of the molten resin. As a result, the external output terminal of the electrical component is closed by the inner wall surface of the cavity, so that the external output terminal can be reliably prevented from being covered with the resin mold. Since the intermediate assembly may be positioned and set in the cavity of the mold with a play, the mounting of the intermediate assembly into the mold and the removal of the product battery pack from the mold can be easily performed.
[0012]
BEST MODE FOR CARRYING OUT THE INVENTION
FIGS. 1 to 3 show a battery pack P to which the present invention is applied. The battery pack P has a flat rectangular box shape, electrical components attached to the outer peripheral side surface of the unit battery 1, and electrical components mounted on the unit battery 1. And a resin mold 2 for integrating products. Here, it should be noted that the external output terminals 3 and 4 included in the electric component are provided on the front surface of the unit cell 1 so as to face the outside.
[0013]
The unit cell 1 is formed into a rectangular flat rectangular box whose upper and lower surfaces are formed substantially flat, and whose vertical thickness is small and long in the front-rear direction. Electrical components are arranged on the outer peripheral side surface of the unit cell 1. ing. The resin mold 2 covers the electrical components and the outer peripheral side surface excluding the upper and lower surfaces of the unit cell 1. The resin mold 2 is formed from a polyamide resin, a styrene-based elastomer resin, an ethylene / vinyl acetate (EVA) -based or polyurethane (PUR) -based hot melt resin, or the like.
[0014]
In FIG. 2, the unit cell 1 is composed of a chargeable / dischargeable secondary battery in which an electrode body and an electrolyte are sealed inside an outer can 5, for example, a lithium ion battery, and a sealing plate 6 for closing the front surface of the outer can 5. A positive terminal 7 is provided at the center. The outer can 5 is formed by deep drawing a nickel plate, an aluminum plate, or the like, and also serves as an output terminal on the negative electrode side. The electrode body is formed by spirally winding a positive electrode sheet using LiCoO ₂ as an active material and a negative electrode sheet using graphite as an active material with a separator interposed therebetween, and crushing the whole flat.
[0015]
The electrical components are a protection circuit module 9 disposed on the front side of the unit cell 1, a polyswitch 10 disposed on the rear side of the unit cell 1, both of these, and the positive terminal 7 and the protection circuit. It has two types of long and short lead wires 11 and 12 for connecting to the module 9 respectively.
[0016]
The protection circuit module 9 is made of a left-right horizontally long plastic molded product in which a protection circuit for controlling the charging / discharging current of the unit cell 1 is embedded, and strip-shaped connection leads 13 and 14 are respectively drawn backward from left and right ends. The above protection circuit prevents overdischarge and overcharge of the unit cell 1. The external output terminal 3 on the positive electrode side and the external output terminal 4 on the negative electrode side are provided outside the front surface of the protection circuit module 9.
[0017]
The polyswitch 10 is provided to cut off the current of the unit cell 1 when the temperature of the unit cell 1 exceeds a set value, and has a connection lead 17 at one end. The upper and lower thickness dimensions of the protection circuit module 9 and the polyswitch 10 are set slightly smaller than the thickness dimension of the unit cell 1. The lead wires 11 and 12 and the connection leads 13, 14 and 17 are formed by cutting a thin sheet of a conductive metal such as copper or aluminum into a strip shape. It is set smaller than the thickness dimension.
[0018]
The electrical component is temporarily assembled on the outer peripheral side surface of the unit cell 1 to obtain an intermediate assembly 19 shown in FIG. The electrical component has a separate protective cover 20, which is mounted on the outside of the front surface of the protective circuit module 9. Specifically, the short lead wire 12 on the left and the long lead wire 11 on the right are spot-welded to the connection leads 13 and 14 at both left and right ends of the protection circuit module 9, respectively. Are connected by spot welding to connect the electrical components to one another.
[0019]
Next, after attaching the short lead wire 12 to the sealing plate 6 via an insulating double-sided tape, the short lead wire 12 is spot-welded to the positive electrode terminal 7. Similarly, a long lead wire 11 is attached to the left lateral side of the unit cell 1 via an insulating double-sided tape, and a polyswitch 10 is attached to the rear side of the unit cell 1 via an insulating double-sided tape. The sticking surface is spot-welded to the outer can 5.
[0020]
The protective cover 20 is formed of a strip-shaped plastic molded product that is long in the left-right direction. As shown in FIG. 2, windows 21 and 22 corresponding to the positive and negative external output terminals 3 and 4 of the protective circuit module 9 are provided in a penetrating manner. is there. In a state where the external output terminals 3 and 4 are fitted into the windows 21 and 22, the intermediate cover 19 is formed by attaching the protective cover 20 to the outer front surface of the protective circuit module 9.
[0021]
(Embodiment 1) FIGS. 4 and 5 show Embodiment 1 of a mold for molding the resin mold 2 on the intermediate assembly 19. This molding die includes a first die (fixed die) 24 and a second die (movable die) 25, and the unit cell 1 is placed in a cavity 26 formed inside both dies 24. After the positioning and mounting, the molten resin is injected into the cavity 26 from the resin injection gate 27. The molding die is provided with a sprue 28 to which the molten resin is supplied, and a runner 29 connecting the sprue 28 and the resin injection gate 27. The molten resin is supplied to the sprue 28, the runner 29, and the resin injection gate 27. Through the cavity 26.
[0022]
The resin injection gate 27 is disposed at a position facing the center of the rear side surface of the unit cell 1 set in the cavity 26. The injection pressure of the molten resin from the resin injection gate 27 into the cavity 26 is preferably higher from the viewpoint of the injection speed, but if it is excessively high, the unit cell 1 may be damaged. It is set in the range of 1 to 5 MPa. The temperature of the molten resin is set to about 200 ° C.
[0023]
When the intermediate assembly 19 is mounted in the cavity 26 of the first mold 24, the front outer surface of the protective cover 20 is in close proximity to the front surface of the inner wall surface of the cavity 26 as shown in FIG. At this time, the left and right lateral sides and the rear side of the unit cell 1 are positioned by the pins 30 provided in the cavity 26. However, there is a slight gap between the pins 30 and the unit cell 1, and the protection cover 20 There is also a slight gap between the outside front surface of the cavity and the inner wall surface of the cavity 26 facing the outside front surface.
[0024]
When the molten resin is injected from the resin injection gate 27 to the rear side of the unit cell 1, the whole of the intermediate assembly 19 is pushed forward by the injection pressure of the molten resin, and in some cases, is pushed and moved. As a result, the outer front surface of the protective cover 20 is pressed against the inner wall surface of the cavity 26 in close contact, and the intermediate assembly 19 is non-movably positioned and held in the cavity 26. In this state, the molten resin flows from the rear side gap of the unit cell 1 into the left and right side gaps, and a part of the molten resin finally reaches the outside of the left and right ends of the protective cover 20.
[0025]
Since the outer front surface of the protective cover 20 is in close contact with the inner wall surface of the cavity 26, there is a gap between the front surface of the protective cover 20 and the inner wall surface of the cavity 26 when the intermediate assembly 19 is mounted in the cavity 26. Even if it does, the molten resin does not enter around the windows 21 and 22 of the protective cover 20. Therefore, the windows 21 and 22 for exposing the positive and negative external output terminals 3 and 4 of the protection circuit module 9 can be reliably prevented from being blocked by the molten resin, that is, the resin mold 2.
[0026]
After the molten resin is solidified, the second mold 25 is separated from the first mold 24, and the unit 1 is pushed out from the second mold 25, so that the electrical component is formed on the outer peripheral side surface of the unit 1 The product battery pack P of FIG. 1 integrated with the mold 2 was obtained.
[0027]
(Embodiment 2) FIGS. 6 to 8 show Embodiment 2 of the present invention in which the protective cover 20 of Embodiment 1 is omitted, and the external output terminals 3 and 4 of the intermediate assembly 19 are provided on the inner wall surface of the cavity 26. Are formed to directly receive the outer side of the front surface. Specifically, the corresponding protruding portions 31 are constituted by cores provided in the molds 24 and 25 so as to be able to move back and forth.
[0028]
In the second embodiment, when the molten resin is injected from the resin injection gate 27 to the rear side of the unit cell 1, the entire intermediate assembly 19 is pushed forward by the injection pressure of the molten resin, and the positive and negative external output terminals are set. The outer front surfaces of the protrusions 3 and 4 are pressed against the protruding end surfaces of the protruding portions 31 and 31 in this state. In this state, the cavity 26 is filled with the molten resin and the resin mold 2 is formed. The molten resin also wraps around between the front surface of the protection circuit module 9 and the inner wall surface of the cavity 26 opposed thereto, and the product battery pack P taken out of the mold has the protrusions 31 as shown in FIG. A window in which the external output terminals 3 and 4 face the outside is formed in the existing portion. Since other points are the same as those of the first embodiment, the same members are denoted by the same reference numerals and description thereof will be omitted.
[0029]
Third Embodiment FIG. 9 shows a third embodiment of the present invention. In the mold of the third embodiment, in addition to the gate (first gate) 27 of the first embodiment, second gates 34, 34 facing the left and right sides of the unit cell 1 are arranged.
[0030]
The second gates 34 communicate with the runner (first runner) 29 of the first embodiment via left and right second runners 35 and 35, and the molten resin is sprue 28, the first runner 29 and the second runner 35. , And also flows to each second gate 34.
[0031]
In the third embodiment, when the molten resin from the sprue 28 reaches the first gate 27, it has not yet reached each second gate 34. Accordingly, the molten resin is first injected from the first gate 27 to the rear side of the unit cell 1, and the injection pressure pushes the unit cell 1 forward. Thus, the outer front surface of the protective cover 20 is pressed against the front wall of the cavity 26 in the same manner as in the first embodiment. In this state, the molten resin flows from the rear gap of the unit cell 1 to the left and right side gaps, and also flows from the second gates 34 to the left and right side gaps of the unit cell 1.
[0032]
In the third embodiment, the molten resin flows into the left and right sides of the unit cell 1 quickly and in a well-balanced manner by the arrangement of the second gates 34 on the left and right, so that the molding accuracy and the molding cycle can be improved. The other configuration is the same as that of the first embodiment, so that the same members are denoted by the same reference numerals and description thereof will be omitted.
[0033]
Fourth Embodiment FIGS. 10 and 11 show a fourth embodiment of the present invention, in which a resin mold 2 is formed into a U-shape that covers the front and rear sides and the right side of the outer peripheral side of the unit cell 1. I have. In this case, the resin injection gate 27 is disposed so as to face the right lateral side of the unit cell 1. Here, the resin injection gate 27 is set at a position where the distance to the rear side of the unit cell 1 is shorter than the distance to the front side of the unit cell 1. The other parts are the same as those in the first embodiment, and the same members are denoted by the same reference numerals and description thereof will be omitted.
[0034]
In the fourth embodiment, the molten resin from the resin injection gate 27 flows into the rear side and the front side of the unit cell 1 separately. At this time, the molten resin reaches the rear side of the unit cell 1 first and pushes the intermediate assembly 19 toward the front side by the injection pressure at this time. As a result, the outer front surface of the protective cover 20 is pressed against the front wall of the cavity 26 in close contact. In this state, further molten resin also flows to the front side of the unit cell 1 with a delay, and covers the front, rear, and right sides of the unit cell 1. According to this, the molten resin from the resin injection gate 27 quickly spreads to the rear side and the front side of the unit cell 1, and the molding cycle can be shortened.
[0035]
The protection circuit described above is not limited to those having the functions described in the embodiments, and can be configured as necessary circuits according to the use of the battery pack. For example, the leads 11 and 12 may be linear conductors.
[Brief description of the drawings]
FIG. 1 is a perspective view of a battery pack. FIG. 2 is an exploded perspective view of a unit cell and electrical components. FIG. 3 is a perspective view of an intermediate assembly. FIG. 4 is a cross-sectional plan view showing a mold structure of the first embodiment. FIG. 5 is a vertical sectional side view showing a mold structure of the first embodiment. FIG. 6 is a cross-sectional plan view of a main part showing a mold structure of the second embodiment. FIG. FIG. 8 is a perspective view of a battery pack according to a second embodiment. FIG. 9 is a cross-sectional plan view illustrating a mold structure according to a third embodiment. FIG. 10 is a cross-sectional plan view illustrating a mold structure according to a fourth embodiment. 11 is a perspective view of a battery pack according to a fourth embodiment.
DESCRIPTION OF SYMBOLS 1 Unit cell 2 Resin mold 3 Positive side external output terminal 4 Negative side external output terminal 9 Protection circuit module 19 Intermediate assembly 20 Protective covers 21 and 22 Window 24 First mold 25 Second mold 26 Cavity 27 Resin injection Gate

Claims

A square box-shaped unit cell, an electrical component attached to an outer peripheral side surface of the unit cell, and including an external output terminal disposed on a front side of the unit cell, and a resin mold for integrating the electrical component with the unit cell In a method for manufacturing a battery pack comprising:
In a cavity of a mold for molding a resin mold, an intermediate assembly in which the electric component is temporarily attached to the unit cell is set,
When injecting the molten resin into the cavity, press the intermediate assembly forward with the injection pressure of the molten resin,
A method for manufacturing a battery pack, characterized in that the resin mold is formed in a state in which the front surface of the external output terminal is closed on the inner wall surface of the cavity so that the molten resin does not flow around the terminal.

The method for manufacturing a battery pack according to claim 1, wherein the resin injection gate of the mold is positioned so as to face a rear surface of the unit cell.

The method for manufacturing a battery pack according to claim 1, wherein the resin mold is formed over the entire outer peripheral side surface of the unit cell.

3. The method for manufacturing a battery pack according to claim 1, wherein the resin mold is formed over the front and rear sides and one of the left and right lateral sides of the outer peripheral side surface of the unit cell. 4.

The electrical component includes a protective cover for preventing the molten resin from wrapping around the front surface of the external output terminal,
2. The method according to claim 1, wherein when the molten resin is injected into the cavity, an outer front surface of the protective cover is pressed against an inner wall surface of the cavity in an intimate manner. 3.