JP2004104911A

JP2004104911A - Electric connection box

Info

Publication number: JP2004104911A
Application number: JP2002263312A
Authority: JP
Inventors: Mitsuo Tanaka; 田中　光男
Original assignee: Furukawa Electric Co Ltd
Current assignee: Furukawa Electric Co Ltd
Priority date: 2002-09-09
Filing date: 2002-09-09
Publication date: 2004-04-02
Anticipated expiration: 2022-09-09
Also published as: JP4115209B2

Abstract

<P>PROBLEM TO BE SOLVED: To provide an electric connection box high in reliability without causing the separation of the connecting part of a terminal and a circuit board due to the influence of a temperature. <P>SOLUTION: The electric connection box 1 comprises boxes 2, 5 and 6, the electric circuit boards 30 housed in the boxes, a plurality of terminals T that are joined to the electric circuit boards at one-side ends and extruded outside the boxes at other ends, and terminal holders 31 that are fixed to the electric circuit boards and press-hold the terminals. A terminal hole formed at each box and makes the other end of the terminal protrude outside the box is formed such that at least two adjacent terminals are protruded from at least one terminal hole 21. <P>COPYRIGHT: (C)2004,JPO

Description

【０００１】
【発明が属する技術分野】
本発明は、例えば車両のバッテリ（電源）と車両に搭載される種々の電気機器との接続途中に使用される電気接続箱に関する。
【０００２】
【従来の技術】
従来から、例えば車両のバッテリとオルタネータやヒータ、ファン等の車両に搭載される電気機器との間は複雑に分岐したワイヤハーネスで電気的に接続されている。そして、バッテリから供給される電力をこれらの電気機器に分配することと、これらの電気機器を過電流から保護することを目的として、電気接続箱がバッテリと電気機器との間のワイヤハーネスに接続されている。
【０００３】
かかる電気接続箱は、筐体を構成する樹脂製のハウジング、アッパーケース、ロアケース、アッパーカバー及びロアカバーと、ロアケースとアッパーケースとの間に収容され、リレー等の電気部品を備えた基板アッシーと、複数の独立した電気回路を構成するバスバーと、独立した電気回路のそれぞれに介在される回路保護用のヒューズ等を備えている。
【０００４】
そして、図５に示すように基板アッシーの電気回路基板１３０には信号系の電気回路や電力制御系の電気回路など様々な回路が形成され（図５には各回路は図示せず）、各回路ごとにＬ字状に折曲された複数の端子Ｔが接合されている。すなわち、端子Ｔの一辺側端部が各回路パターンにはんだ接合され、端子Ｔの他辺は、電気回路基板１３０に固着された直方体形状の端子保持ハウジング１３１に圧入されている。また、ロアケース１２には、図６に示すように各端子Ｔに対応する端子孔１２１が形成されている。そして、端子Ｔの他辺側端部は、図７に示すように端子Ｔごとに各端子孔１２１からそれぞれロアケース１２の外部に突出している。外部に突出した端子Ｔはそれぞれコネクタを介してワイヤハーネス等に接続されるようになっている。
【０００５】
なお、電気接続箱のアッパーケースに形成された各端子孔から２つ以上の端子Ｔを、ヒューズハウジングを介して外部に突出させる構成を有した電気接続箱も従来から公知である（例えば、特許文献１参照。）
【特許文献１】
特開２０００−２８７３３７号公報（第２−３頁、図１）
【発明が解決しようとする課題】
上述のように、外部接続を行なう端子Ｔは端子保持ハウジング１３１を介して回路基板１３０に固定され、その端部はロアケース１２の端子孔１２１から突出している。そして、端子孔１２１は端子１本に対し１個の孔が対応して形成される構成をとっているので各構成要素の熱膨張率の違いに起因する問題が生じていた。
【０００６】
具体的には、電気回路基板１３０は心材としてアルミニウムを使用し、端子保持ハウジング１３１はＰＢＴ（ポリブチレンテレフタレート）を使用し、端子孔１２１の形成されたロアケース１２にはナイロン系樹脂が使用されている。すなわち、これら全て熱膨張率が異なる構成要素でできている。ここで、２部品（２つの構成要素）の熱膨脹差を互いに吸収しあうことは可能だが、電気回路基板１３０、端子保持ハウジング１３１、及びロアケース１２の３部品（３つの構成要素）の熱膨脹差を合わせることは各部品の機能やコスト面から考えると難しい。そして、端子Ｔが上述の各構成要素によって寸法的に拘束されているので、各構成要素間の熱膨脹差で端子Ｔと回路基板１３０とのはんだ接合部への応力集中が生じ、はんだ部にクラックが発生して電気回路が不導通となる恐れがある。その為、端子保持ハウジング１３１をコネクタ（図示せず）に結合可能なものとし、電気回路基板に直接設けるやり方もあるが、接続するコネクタの数や種類が増えてコストアップとなり好ましくない。
【０００７】
一方、後者の従来構造、すなわち電気接続箱の筐体に形成された各端子孔から２つ以上の端子を、ヒューズハウジングを介して外部に突出させるタイプのものは、端子の基端部がバスバーと一体化するか圧接接続部を介して電線と接続されている構成を有しているので、前者の従来構造のように端子基端部が回路基板に直接はんだ接合されておらず、上述したような不都合は生じない。すなわち、上述のような解決すべき技術的課題を有さない構造であり、本発明の技術的課題を解決できる構造ではない。
【０００８】
本発明の目的は、温度の影響によって端子と回路基板とのはんだ接合部が剥離することのない信頼性の高い電気接続箱を提供することにある。
【０００９】
【課題を解決するための手段】
上述の課題を解決するために、本発明にかかる電気接続箱は、筐体と
当該筐体内部に収容された電気回路基板と、一端が電気回路基板に直接接合され、他端が筐体外部に突出した複数の端子と、電気回路基板に固定され、端子を圧入保持する端子ホルダとを備えた電気接続箱において、端子他端を外部に突出させる筐体の端子孔は、少なくとも１つの端子孔が少なくとも２つの隣接する端子を突出させている。
【００１０】
従来のように一つの端子に対して一つの端子孔が筐体に形成されているのではなく、端子孔から少なくとも二つの隣接する端子を突出させるように端子孔が形成されているので、筐体と端子とが干渉して端子と電気回路基板との接合部に過大な応力が作用することによる当該接合部の剥離を防止する。また、このような端子接合部の剥離を阻止するために電気回路基板に装着する端子ホルダの数や種類を増やす必要がない。
【００１１】
また、本発明の請求項２に記載の電気接続箱は、請求項１に記載の電気接続箱において、端子が細長板状の端子からなり、端子孔から突出する少なくとも２つの隣接する端子は端子の幅方向に隣接した端子である。
【００１２】
端子が細長板形状を有しているので端子幅方向の剛性が高く、端子がその幅方向において筐体と干渉すると、これに伴う応力が電気回路基板と端子との接合部に直接作用して当該接合部の剥離を招く。しかしながら、筐体の端子孔は端子幅方向に隣接する少なくとも二つの端子を突出するようになっているので、かかる端子幅方向における端子と筐体との干渉を防止し、過大な応力が端子と電気回路基板との接合部に作用することなく当該接合部の剥離を回避する。
【００１３】
また、本発明の請求項３に記載の電気接続箱は、請求項１又は請求項２に記載の電気接続箱において、電気回路基板、端子保持部、及び筐体の熱膨張率が互いに異なっている。
【００１４】
電気回路基板、電気回路基板に固定された端子保持部、これらの回路基板や端子保持部によって拘束された端子の端部を突出させる筐体が互いに異なる熱膨脹率を有している。しかしながら、端子孔は少なくとも二つの隣接する端子を突出させるようになっているので、電気接続箱の温度上昇に伴い各構成要素の寸法関係がずれて端子と筐体の端子孔との位置関係が変化しても、端子と筐体との干渉が起こりにくい。従って、かかる干渉に伴う端子と電気回路基板との接合部への応力集中を阻止し、当該接合部の剥離を回避する。
【００１５】
また、本発明の請求項４に記載の電気接続箱は、請求項３に記載の電気接続箱において、筐体の熱膨張率が端子保持部や電気回路基板の熱膨張率に比べて大きい。
【００１６】
筐体の熱膨張率が端子保持部や電気回路基板の熱膨張率に比べて大きいと、従来型の電気接続箱では端子端部が筐体の熱膨張により端子幅方向に大きく偏移され、これにより端子と電気回路基板との接合部に過大なねじりモーメントを発生させて端子接合部のはんだ剥離を引き起こしていたが、請求項４に記載の本発明の場合、端子孔が少なくとも二つの隣接する端子を突出させるようになっているので、筐体の熱膨張による端子の幅方向への偏移を生じさせることがなく、その結果、端子と電気回路基板との接合部に過大なねじりモーメントを発生させずに済み、端子接合部のはんだ剥離を回避できる。
【００１７】
【発明の実施の形態】
以下、本発明の一実施形態にかかる電気接続箱について図面に基づいて説明する。
【００１８】
本発明の一実施形態にかかる電気接続箱１は、図１に示すように、樹脂製のロアケース２と、ロアケース内部に装着される基板アッシー３と、独立した電気回路を構成するバスバー４と、ヒューズＨａ，Ｈｂ・・が実装されるアッパーケース５と、アッパーケース５に被着されるアッパーカバー６等を備えている。
【００１９】
基板アッシー３は、図１及び図２に示すように、複数のリレー及びコネクタがそれぞれ装着される電気回路基板３０と、当該回路基板３０の上縁に沿って固定された端子保持ハウジング（ヒューズホルダハウジング）３１と、当該回路基板３０の下縁に沿って固定された端子保持ハウジング（基板コネクタハウジング）３２と、これらの端子保持ハウジング３１，３２に一部が圧入され一端が電気回路基板３０にはんだ接合された複数のＬ字型端子Ｔとを備えている。一方、ロアケース２には、図３に示すように当該端子Ｔの他端（先端）を突出させる端子孔２１（図１では図示せず）が形成されている。
【００２０】
尚、電気回路基板３０は芯材がアルミニウムでできており、端子保持ハウジング３２はＰＢＴ（ポリブチレンテレフタレート）でできており、ロアケース２はナイロン系の樹脂材でできている。すなわち、電気回路基板３０、端子保持ハウジング３２、及びロアケース２は全て異なる熱膨脹係数を有し、ロアケース２の熱膨張係数が最も大きく、電気回路基板３０の熱膨張係数が最も小さくなっている。
【００２１】
ロアケースの端子孔２１は、図３に示すように、マトリックス状の配された複数の細長の孔からなる。そして、それぞれの孔には図４に示すように端子幅方向に隣接した４つの端子先端部が突出した状態で電気接続箱が組み付けられる。各端子Ｔは、図２に示すようにＬ字型に折曲された細長の金属板からなり、一端が電気回路基板３０の端子挿通孔（図示せず）に挿通されるとともに当該挿通部がはんだ接合されている（図２中、はんだ接合部Ｓ参照）。そして、電気回路基板３０には細長の直方体形状からなる端子保持ハウジング３２が固着され、当該ハウジング３２に各端子Ｔの長辺側中央部が圧入されている。端子Ｔは端子保持ハウジング３２から一部が図中上方に突出し、ロアケース２の細長の端子孔２１を貫通して端子幅方向に隣接する４本の端子端部が全て一つの端子孔２１から外部に突出している。尚、ロアケース２から突出した端子Ｔの端部は図示しないコネクタに接続され、ワイヤハーネス（図示せず）と電気的に接続されるようになっている。
【００２２】
このように、端子Ｔは従来の電気接続箱のように端子ごとに一つの端子孔１２１から突出されるのではなく、複数の（本実施形態では４本の）端子Ｔが一つの端子孔２１から突出されているので、端子Ｔと端子孔２１との間の寸法関係に余裕をもつことができる。従って、内部発熱等により電気接続箱１が温度上昇することで、電気回路基板３０、端子保持ハウジング３２、ロアケース２との間で熱膨張係数の違いに基づく寸法関係のずれが生じても、端子Ｔと端子孔２１とが干渉することがない。
【００２３】
なお、ロアケース２は、コスト上の理由でナイロン系樹脂を使用しており、熱膨張係数が他の構成要素に較べて大きく、このような寸法関係のずれが生じ易い。しかしながら、上述の構成をとることで端子Ｔと端子孔２１とが干渉しにくく、端子Ｔと電気回路基板３０との端子接合部への応力集中によるはんだ剥離等を防止することができる。
【００２４】
端子Ｔは細長の板状体であるので端子幅方向の剛性が高い。そのため、端子幅方向がロアケース２と干渉すると、これに伴う応力が電気回路基板３０と端子Ｔとの接合部に直接作用して当該接合部に過大なねじりモーメントを発生させ、はんだ接合部の剥離を招く。しかしながら、ロアケース２の端子孔２１は端子幅方向に隣接する４本の端子Ｔを突出させているので、かかる端子幅方向において端子Ｔがロアケース２と干渉することがない。その結果、過大な応力が端子Ｔと電気回路基板３０との接合部に作用することもなく、当該接合部のはんだ剥離を確実に防止することができる。
【００２５】
一方、端子孔２１は従来の端子孔１２１に比べて大きく形成されているので、ロアケース２を成型する際、金型のピンを従来のロアケース１２のように多数必要としない。また、成型精度も従来ほど厳密に要求されないので、生産性が向上するとともに金型製造のコストダウンを図ることができる。
【００２６】
なお、上述の実施形態のように１つの端子孔から端子を突出させる本数は４本に限定されず、２本以上の端子であれば端子接合部のはんだ剥離防止の効果を奏する。
【００２７】
また、全ての端子孔から端子Ｔを２本以上突出させる必要は必ずしもなく、特に各構成要素の熱膨張率の違いに基づく干渉が生じ易い部分にこのような端子孔を形成しただけでも効果を上げることができる。
【００２８】
更に、端子は必ずしも板状体でなくても良く、断面円形の細長棒状部材を端子として使用しても良い。しかしながら、端子を板状体とし、この端子の幅方向に２つ以上の端子を突出させる端子孔をロアケースに形成することで、上述した端子と電気回路基板との接合部に作用するねじりモーメントの発生を効果的に阻止できる。
【００２９】
また、端子孔は必ずしもロアケースに形成する必要はなく、アッパーケース等、電気接続箱の筐体を構成する部分に形成してあれば良い。
【００３０】
更にまた、ロアケース、端子保持ハウジング、電気回路基板の各材質は上述した材質に限定される必要はないが、ロアケースの材質を、熱膨張係数が他の構成要素の材質よりも大きいものとした場合、ロアケースを一般に廉価に成型できるとともに上述のような端子孔の存在により端子と電気回路基板の接合部の剥離を効果的に防止できる。
【００３１】
【発明の効果】
以上説明したように、本発明にかかる電気接続箱は、従来のように一つの端子に対して一つの端子孔が筐体に形成されているのではなく、端子孔から少なくとも二つの隣接する端子を突出させるように端子孔が形成されている。従って、筐体と端子とが干渉して端子と電気回路基板との接合部に過大な応力が作用することによる当該接合部の剥離を防止することができる。また、このような端子接合部の剥離を阻止するために電気回路基板に装着する端子ホルダの数や種類を増やす必要がない。
【００３２】
また、端子が細長板形状を有していると端子幅方向の剛性が高くなるので、端子がその幅方向において筐体と干渉するとこれに伴う応力が電気回路基板と端子との接合部に直接作用して当該接合部の剥離を招く。しかしながら、本発明の請求項２に記載の電気接続箱は、筐体の端子孔は端子幅方向に隣接する少なくとも二つの端子を突出するようになっているので、かかる端子幅方向における筐体との干渉を防止し、過大な応力が端子と電気回路基板との接合部に作用することなく当該接合部の剥離を回避する。
【００３３】
また、本発明の請求項３に記載の電気接続箱は、電気回路基板、電気回路基板に固定された端子保持部、これらの回路基板や端子保持部によって拘束された端子の端部を突出させる筐体が互いに異なる熱膨脹率を有している。しかしながら、端子孔は少なくとも二つの隣接する端子を突出させるようになっているので、電気接続箱の温度上昇に伴い各構成要素の寸法関係がずれて端子と筐体の端子孔との位置関係が変化しても端子と筐体との干渉が起こりにくい。従って、かかる干渉に伴う端子と電気回路基板との接合部への応力集中を阻止し、当該接合部の剥離を回避することができる。
【００３４】
また、筐体の熱膨張率が端子保持部や電気回路基板の熱膨張率に比べて大きいと、従来型電気接続箱の構成では端子端部が筐体の熱膨張により端子幅方向に大きく偏移され、これにより端子と電気回路基板との接合部に過大なねじりモーメントを発生させて端子接合部のはんだ剥離を引き起こしていた。しかしながら、本発明の請求項４に記載の電気接続箱の場合、端子孔が少なくとも二つの隣接する端子を突出させるようになっているので、筐体の熱膨張による端子の幅方向への偏移を生じさせることがなく、その結果、端子と電気回路基板との接合部に過大なねじりモーメントを発生させずに済み、端子接合部のはんだ剥離を回避できる。
【図面の簡単な説明】
【図１】本発明の一実施形態にかかる電気接続箱の分解斜視図である。
【図２】図１の電気接続箱を組み付けた状態を部分的に破断してロアケース側から見て示す拡大斜視図である。
【図３】図１のロアケースを裏側から見て部分的に拡大して示す斜視図である。
【図４】図３のロアケースから端子が突出した状態を示す斜視図である。
【図５】従来の電気接続箱を組み付けた状態を一部破断してロアケース側から見て示す拡大斜視図である。
【図６】従来の電気接続箱のロアケースを裏側から見て部分的に拡大して示す斜視図である。
【図７】図６のロアケースから端子が突出した状態を示す斜視図である。
【符号の説明】
１　　電気接続箱
２　　ロアケース
３　　基板アッシー
４　　バスバー
５　　アッパーケース
６　　アッパーカバー
１２　　ロアケース
２１　　端子孔
３０　　電気回路基板
３１　　端子保持ハウジング（ヒューズホルダハウジング）
３２　　端子保持ハウジング（基板コネクタハウジング）
１２１　　端子孔
１３０　　電気回路基板
１３１　　端子保持ハウジング
Ｈａ，Ｈｂ・・　　ヒューズ
Ｓ　　はんだ接合部
Ｔ　　端子[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an electric connection box used during connection between a battery (power supply) of a vehicle and various electric devices mounted on the vehicle, for example.
[0002]
[Prior art]
2. Description of the Related Art Conventionally, for example, a battery of a vehicle and electrical devices mounted on the vehicle such as an alternator, a heater, and a fan are electrically connected to each other by a complicatedly branched wire harness. The electric connection box is connected to the wiring harness between the battery and the electric device for the purpose of distributing the electric power supplied from the battery to these electric devices and protecting these electric devices from overcurrent. Have been.
[0003]
Such an electric connection box is a resinous housing that forms the housing, an upper case, a lower case, an upper cover and a lower cover, and a board assembly that is housed between the lower case and the upper case and includes electrical components such as a relay. It has a bus bar that constitutes a plurality of independent electric circuits, and a fuse for circuit protection interposed in each of the independent electric circuits.
[0004]
Then, as shown in FIG. 5, various circuits such as a signal system electric circuit and a power control system electric circuit are formed on the electric circuit board 130 of the board assembly (each circuit is not shown in FIG. 5). A plurality of terminals T bent in an L-shape are joined for each circuit. That is, one side end of the terminal T is soldered to each circuit pattern, and the other side of the terminal T is pressed into a rectangular parallelepiped terminal holding housing 131 fixed to the electric circuit board 130. Further, terminal holes 121 corresponding to the terminals T are formed in the lower case 12 as shown in FIG. The other side end of the terminal T protrudes from the terminal hole 121 to the outside of the lower case 12 for each terminal T as shown in FIG. The terminals T protruding to the outside are each connected to a wire harness or the like via a connector.
[0005]
An electric connection box having a configuration in which two or more terminals T are projected outside through a fuse housing from each terminal hole formed in an upper case of the electric connection box is also known in the related art. Reference 1)
[Patent Document 1]
JP-A-2000-287337 (page 2-3, FIG. 1)
[Problems to be solved by the invention]
As described above, the terminal T for external connection is fixed to the circuit board 130 via the terminal holding housing 131, and its end protrudes from the terminal hole 121 of the lower case 12. Since the terminal hole 121 has a structure in which one hole is formed corresponding to one terminal, a problem arises due to a difference in the coefficient of thermal expansion of each component.
[0006]
Specifically, the electric circuit board 130 uses aluminum as a core material, the terminal holding housing 131 uses PBT (polybutylene terephthalate), and the lower case 12 in which the terminal holes 121 are formed is made of nylon resin. I have. That is, all of them are made of constituent elements having different coefficients of thermal expansion. Here, although it is possible to mutually absorb the thermal expansion difference of two parts (two components), the thermal expansion difference of three parts (three components) of the electric circuit board 130, the terminal holding housing 131, and the lower case 12 is determined. It is difficult to match them from the viewpoint of the function and cost of each part. Since the terminal T is dimensionally constrained by the above-described components, stress concentration occurs in a solder joint between the terminal T and the circuit board 130 due to a difference in thermal expansion between the components, and cracks occur in the solder. May occur and the electrical circuit may become non-conductive. Therefore, there is a method in which the terminal holding housing 131 is connectable to a connector (not shown) and is provided directly on the electric circuit board. However, the number and types of connectors to be connected increase, which is not preferable because the cost increases.
[0007]
On the other hand, the latter conventional structure, that is, a type in which two or more terminals are protruded to the outside through a fuse housing from each terminal hole formed in the housing of the electric junction box, has a base end portion of the bus bar. And the terminal base end is not directly solder-joined to the circuit board as in the former conventional structure, as described above. Such inconvenience does not occur. That is, the structure does not have the technical problem to be solved as described above, and is not a structure that can solve the technical problem of the present invention.
[0008]
An object of the present invention is to provide a highly reliable electric junction box in which a solder joint between a terminal and a circuit board does not peel due to the influence of temperature.
[0009]
[Means for Solving the Problems]
In order to solve the above-described problems, an electric connection box according to the present invention includes a housing, an electric circuit board housed in the housing, one end directly connected to the electric circuit board, and the other end connected to the outside of the housing. A terminal hole of a housing for projecting the other end of the terminal to the outside, wherein the terminal hole has at least one terminal. A hole projects at least two adjacent terminals.
[0010]
Unlike the conventional case, one terminal hole is formed in the housing for one terminal, but terminal holes are formed so that at least two adjacent terminals protrude from the terminal holes. This prevents peeling of the joint due to excessive stress acting on the joint between the terminal and the electric circuit board due to interference between the body and the terminal. Further, it is not necessary to increase the number and types of terminal holders mounted on the electric circuit board in order to prevent such peeling of the terminal joint.
[0011]
The electric connection box according to claim 2 of the present invention is the electric connection box according to claim 1, wherein the terminal is formed of an elongated plate-shaped terminal, and at least two adjacent terminals protruding from the terminal hole are terminals. Are terminals adjacent in the width direction.
[0012]
Since the terminal has an elongated plate shape, the rigidity in the terminal width direction is high, and when the terminal interferes with the housing in the width direction, the stress accompanying it directly acts on the joint between the electric circuit board and the terminal. The peeling of the joint is caused. However, since the terminal hole of the housing projects at least two terminals adjacent in the terminal width direction, interference between the terminal and the housing in the terminal width direction is prevented, and excessive stress is applied to the terminal. Avoiding separation of the joint without acting on the joint with the electric circuit board.
[0013]
According to a third aspect of the present invention, in the electrical junction box according to the first or second aspect, the thermal expansion coefficients of the electrical circuit board, the terminal holding portion, and the housing are different from each other. I have.
[0014]
The electric circuit board, the terminal holding portions fixed to the electric circuit board, and the housings that project the ends of the terminals restrained by the circuit boards and the terminal holding portions have different thermal expansion rates. However, since the terminal holes allow at least two adjacent terminals to protrude, the dimensional relationship between the components is shifted with the rise in the temperature of the electric connection box, and the positional relationship between the terminals and the terminal holes of the housing is reduced. Even if it changes, interference between the terminal and the housing hardly occurs. Therefore, stress concentration on the joint between the terminal and the electric circuit board due to the interference is prevented, and peeling of the joint is avoided.
[0015]
Also, in the electric connection box according to claim 4 of the present invention, in the electric connection box according to claim 3, the thermal expansion coefficient of the housing is larger than that of the terminal holding portion or the electric circuit board.
[0016]
If the coefficient of thermal expansion of the housing is larger than the coefficient of thermal expansion of the terminal holding portion or the electric circuit board, the terminal end of the conventional electrical connection box is greatly shifted in the terminal width direction due to the thermal expansion of the housing. As a result, an excessive torsional moment is generated at the joint between the terminal and the electric circuit board to cause solder peeling at the terminal joint. In the case of the present invention according to claim 4, the terminal hole has at least two adjacent holes. The terminal is designed to protrude, so that the terminal does not shift in the width direction due to thermal expansion of the housing. As a result, an excessive torsional moment is generated at the joint between the terminal and the electric circuit board. Is not generated, and solder peeling at the terminal joint can be avoided.
[0017]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, an electric junction box according to an embodiment of the present invention will be described with reference to the drawings.
[0018]
As shown in FIG. 1, an electric connection box 1 according to one embodiment of the present invention includes a resin lower case 2, a board assembly 3 mounted inside the lower case, and a bus bar 4 forming an independent electric circuit. An upper case 5 on which the fuses Ha, Hb,... Are mounted, an upper cover 6 attached to the upper case 5, and the like are provided.
[0019]
As shown in FIGS. 1 and 2, the board assembly 3 includes an electric circuit board 30 on which a plurality of relays and connectors are mounted, and a terminal holding housing (fuse holder) fixed along an upper edge of the circuit board 30. Housing) 31, a terminal holding housing (board connector housing) 32 fixed along the lower edge of the circuit board 30, a part of the terminal holding housing 31, 32 is press-fitted, and one end is connected to the electric circuit board 30. And a plurality of L-shaped terminals T which are joined by soldering. On the other hand, the lower case 2 is formed with a terminal hole 21 (not shown in FIG. 1) for projecting the other end (tip) of the terminal T as shown in FIG.
[0020]
The core of the electric circuit board 30 is made of aluminum, the terminal holding housing 32 is made of PBT (polybutylene terephthalate), and the lower case 2 is made of a nylon resin material. That is, the electric circuit board 30, the terminal holding housing 32, and the lower case 2 all have different coefficients of thermal expansion, the lower case 2 has the largest coefficient of thermal expansion, and the electric circuit board 30 has the smallest coefficient of thermal expansion.
[0021]
As shown in FIG. 3, the terminal hole 21 of the lower case is composed of a plurality of elongated holes arranged in a matrix. Then, as shown in FIG. 4, the electric junction box is assembled with the four terminal tips adjacent to each other in the terminal width direction projecting into the respective holes. Each terminal T is formed of an elongated metal plate bent into an L shape as shown in FIG. 2, and one end is inserted into a terminal insertion hole (not shown) of the electric circuit board 30 and the insertion portion is Solder joint (see solder joint S in FIG. 2). An elongated rectangular parallelepiped terminal holding housing 32 is fixed to the electric circuit board 30, and the center of the long side of each terminal T is pressed into the housing 32. A part of the terminal T protrudes upward in the drawing from the terminal holding housing 32, and penetrates the elongated terminal hole 21 of the lower case 2, and all four terminal ends adjacent to each other in the terminal width direction are outside the one terminal hole 21. It protrudes. The end of the terminal T protruding from the lower case 2 is connected to a connector (not shown) and is electrically connected to a wire harness (not shown).
[0022]
As described above, the terminals T do not protrude from one terminal hole 121 for each terminal as in a conventional electric connection box, but a plurality of (four in the present embodiment) terminals T are connected to one terminal hole 21. , The terminal T and the terminal hole 21 can have a sufficient dimensional relationship. Therefore, even if the temperature of the electric connection box 1 rises due to internal heat generation or the like, a deviation in the dimensional relationship between the electric circuit board 30, the terminal holding housing 32, and the lower case 2 based on the difference in the thermal expansion coefficient occurs. T and the terminal hole 21 do not interfere.
[0023]
The lower case 2 uses a nylon-based resin for cost reasons, has a larger coefficient of thermal expansion than other components, and such a dimensional relationship easily shifts. However, by adopting the above configuration, the terminal T and the terminal hole 21 hardly interfere with each other, and it is possible to prevent solder peeling or the like due to stress concentration on the terminal joint between the terminal T and the electric circuit board 30.
[0024]
Since the terminal T is a slender plate, the terminal T has high rigidity in the terminal width direction. Therefore, when the terminal width direction interferes with the lower case 2, the resulting stress directly acts on the joint between the electric circuit board 30 and the terminal T, causing an excessive torsional moment at the joint, and peeling of the solder joint. Invite. However, since the terminal holes 21 of the lower case 2 project four terminals T adjacent in the terminal width direction, the terminals T do not interfere with the lower case 2 in the terminal width direction. As a result, an excessive stress does not act on the joint between the terminal T and the electric circuit board 30, and it is possible to reliably prevent the peeling of the solder at the joint.
[0025]
On the other hand, since the terminal hole 21 is formed larger than the conventional terminal hole 121, the molding of the lower case 2 does not require a large number of mold pins unlike the conventional lower case 12. Further, since the molding accuracy is not strictly required as in the conventional case, the productivity can be improved and the cost of manufacturing the mold can be reduced.
[0026]
Note that the number of terminals that protrude from one terminal hole as in the above-described embodiment is not limited to four, and if two or more terminals are used, an effect of preventing solder peeling at the terminal joint portion can be obtained.
[0027]
Further, it is not always necessary to protrude two or more terminals T from all the terminal holes. In particular, even if such a terminal hole is formed in a portion where interference based on the difference in the coefficient of thermal expansion of each component is likely to occur, the effect is obtained. Can be raised.
[0028]
Further, the terminal does not necessarily have to be a plate-like body, and an elongated rod-shaped member having a circular cross section may be used as the terminal. However, by forming the terminal into a plate-like body and forming a terminal hole for projecting two or more terminals in the width direction of the terminal in the lower case, the torsional moment acting on the joint between the terminal and the electric circuit board described above can be reduced. Generation can be effectively prevented.
[0029]
In addition, the terminal holes do not necessarily need to be formed in the lower case, but may be formed in portions such as the upper case that constitute the housing of the electric connection box.
[0030]
Furthermore, each material of the lower case, the terminal holding housing, and the electric circuit board does not need to be limited to the above-described materials, but the material of the lower case has a larger coefficient of thermal expansion than the material of other components. In addition, the lower case can be generally formed at a low cost, and the presence of the terminal holes as described above can effectively prevent the joint between the terminal and the electric circuit board from peeling off.
[0031]
【The invention's effect】
As described above, the electrical junction box according to the present invention is different from the conventional one in that one terminal hole is not formed in the housing for one terminal, but at least two adjacent terminals are formed from the terminal hole. Are formed so as to protrude. Therefore, it is possible to prevent the joint and the terminal from peeling off due to excessive stress acting on the joint between the terminal and the electric circuit board due to interference between the housing and the terminal. Further, it is not necessary to increase the number and types of terminal holders mounted on the electric circuit board in order to prevent such peeling of the terminal joint.
[0032]
In addition, if the terminal has an elongated plate shape, the rigidity in the terminal width direction increases, so if the terminal interferes with the housing in the width direction, the accompanying stress directly applies to the joint between the electric circuit board and the terminal. It acts to cause peeling of the joint. However, in the electrical junction box according to claim 2 of the present invention, the terminal hole of the housing projects at least two terminals adjacent to each other in the terminal width direction. To prevent separation of the joint without excessive stress acting on the joint between the terminal and the electric circuit board.
[0033]
In the electric connection box according to the third aspect of the present invention, an electric circuit board, a terminal holding portion fixed to the electric circuit board, and an end of a terminal restrained by the circuit board or the terminal holding portion are protruded. The housings have different coefficients of thermal expansion. However, since the terminal holes allow at least two adjacent terminals to protrude, the dimensional relationship between the components is shifted with the rise in the temperature of the electric connection box, and the positional relationship between the terminals and the terminal holes of the housing is reduced. Even if it changes, interference between the terminal and the housing does not easily occur. Therefore, it is possible to prevent the concentration of stress on the joint between the terminal and the electric circuit board due to the interference, and to avoid the separation of the joint.
[0034]
In addition, if the thermal expansion coefficient of the housing is larger than the thermal expansion coefficients of the terminal holding portion and the electric circuit board, the terminal ends of the conventional electric connection box are largely biased in the terminal width direction due to the thermal expansion of the housing. As a result, an excessive torsional moment is generated at the joint between the terminal and the electric circuit board, thereby causing solder peeling at the terminal joint. However, in the case of the electric connection box according to the fourth aspect of the present invention, the terminal holes project at least two adjacent terminals, so that the terminals are shifted in the width direction due to thermal expansion of the housing. As a result, it is not necessary to generate an excessive torsional moment at the joint between the terminal and the electric circuit board, and it is possible to avoid solder peeling at the terminal joint.
[Brief description of the drawings]
FIG. 1 is an exploded perspective view of an electric junction box according to an embodiment of the present invention.
FIG. 2 is an enlarged perspective view showing a state in which the electric junction box of FIG. 1 is assembled, partially cut away and viewed from a lower case side.
FIG. 3 is a partially enlarged perspective view of the lower case of FIG. 1 as viewed from the back side.
FIG. 4 is a perspective view showing a state where a terminal protrudes from a lower case of FIG. 3;
FIG. 5 is an enlarged perspective view showing a state in which a conventional electric connection box is assembled, partially cut away and viewed from a lower case side.
FIG. 6 is a partially enlarged perspective view of a lower case of a conventional electric connection box viewed from the back side.
FIG. 7 is a perspective view showing a state where a terminal protrudes from a lower case of FIG. 6;
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Electric connection box 2 Lower case 3 Board assembly 4 Bus bar 5 Upper case 6 Upper cover 12 Lower case 21 Terminal hole 30 Electric circuit board 31 Terminal holding housing (fuse holder housing)
32 Terminal holding housing (board connector housing)
121 Terminal hole 130 Electric circuit board 131 Terminal holding housing Ha, Hb Fuse S Solder joint T Terminal

Claims

A housing;
An electric circuit board housed inside the housing,
A plurality of terminals having one end directly joined to the electric circuit board and the other end protruding outside the housing;
In an electric connection box fixed to the electric circuit board and provided with a terminal holder for press-fitting and holding the terminal,
An electric connection box, wherein at least one terminal hole protrudes at least two adjacent terminals in the terminal hole of the housing that causes the other end of the terminal to protrude to the outside.

2. The electric connection box according to claim 1, wherein the terminal is an elongated plate-shaped terminal, and the at least two adjacent terminals protruding from the terminal hole are terminals adjacent in a width direction of the terminal. 3. .

The electrical junction box according to claim 1, wherein the thermal expansion coefficients of the electric circuit board, the terminal holding unit, and the housing are different from each other.

The electrical junction box according to claim 3, wherein the thermal expansion coefficient of the housing is larger than the thermal expansion coefficients of the terminal holding unit and the electric circuit board.