JP4526221B2

JP4526221B2 - Inverter transformer

Info

Publication number: JP4526221B2
Application number: JP2001554359A
Authority: JP
Inventors: 忠行伏見
Original assignee: Sumida Corp
Current assignee: Sumida Corp
Priority date: 2000-01-20
Filing date: 2001-01-19
Publication date: 2010-08-18
Anticipated expiration: 2021-01-19

Description

技術分野
本発明は、放電灯点灯用のＤＣ／ＡＣインバータ回路に使用されるインバータトランスの構造に関するものである。さらに詳しくは、本発明は、製造が容易であると共に、一対のコア同士の接合部から磁束が外部に漏洩するのを防止できるインバータトランスの構造に関するものである。
背景技術
従来、液晶表示装置のバックライト等に用いる放電灯点灯用のＤＣ／ＡＣインバータ回路に用いられるトランスとして、一般的に１次巻線と２次巻線を、磁性体からなる一対のコアで挟持し、所定の電磁結合を行わせるようにしたものが知られている。またこのようなインバータトランスは設置される場所が狭い間隔のところであり薄型のものが求められる。従来のこの種のトランスとして、例えば、１次巻線は高周波を発生する発振回路（インバータ）の出力端に接続され、２次巻線はバラストコンデンサー等を介して放電灯に接続されている構造のものが知られており、また、バラストコンデンサーの部分をチョークコイルに置き換えた構造のものも知られている。
１次巻線と２次巻線と、互いに対向して配置されて閉磁路を形成する一対のコアとを備え、１次巻線と２次巻線とコアとによって電磁結合を形成する従来一般に用いられているインバータトランスとしては、例えば図１の断面図で示したような構造のものがある。図１において、１０１はＥ型コアを示し、７０１，６０１はそれぞれ前記Ｅ型コアの側脚１０３に巻線した１次巻線および２次巻線である。
２０１はＥ型コア１０１に対向して配置されるＩ型コアであり、Ｅ型コア１０１の中央脚１０２とＩ型コア２０１との間、およびＥ型コアの側脚１０３とＩ型コア２０１との間にギャップ２０２が形成されている。このＥ型コアの側脚１０３とＩ型コア２０１との間のギャップには通常、絶縁材料からなるスペーサー２０３が挟みこまれ、Ｅ型コア１０１とＩ型コア２０１はスペーサー２０３を通して閉磁回路を形成している。このような構造のトランスでは、スペーサー２０３の厚みを変えることによって閉磁回路の磁気抵抗を変化させ、１次巻線７０１と２次巻線６０１の結合度を調整することができる。しかしながら、結合度を調整するには種々の厚みのスペーサーを準備し、所望する結合度によって使い分けする必要があり、部品の点数が増える上に組立て作業が煩雑になる。またスペーサーには厚みがあるためにトランスの高さ寸法を低くすることができず薄型のものを作製し難い欠点がある。さらに、上記構造の場合にはスペーサー２０３の部分から磁束が外部に漏れ、トランスに近接した電子部品や周辺機器などに磁気的な悪影響を与える危険性がある。
特開平１０−３３５１５７号公報には、１次巻線と２次巻線の結合係数の調整を容易にしたインバータトランスとして、閉磁回路を形成する一対のコアと、１次巻線と２次巻線とを備えてなり、一対のコアのうち、下側のコアは、四角形の平板状の部分とその両端部に一体成形された二つの円柱状の突出部とからなり、各突出部にはボビンの巻軸を取りつけ、二つの巻軸にそれぞれ１次巻線、２次巻線を巻回し、１次巻線の一部を２次巻線の上に巻回して構成したものが開示されている。
また特開２０００−１２４０４５号公報には、多灯用のインバータトランスとして、１次巻線を中心にして対称の位置に、同一巻数の第１、第２の２次巻線をそれぞれ配置し、１次巻線と第１の２次巻線、１次巻線と第２の２次巻線とをそれぞれ略同一の結合度で電磁結合させた１個のインバータトランスで複数の出力が得られるように構成したものが開示されている。
これらの発明はいずれも、１次巻線と２次巻線とを並列に配置した構成となっている。特開平１０−３３５１５７号発明においては、１次巻線の一部を２次巻線の上に巻回するように構成してあるため、低圧側の巻線すなわち１次巻線の引出し線が、高電圧側の巻線すなわち２次巻線と交叉して配置されることになり、その結果、各巻線における絶縁性を高めなければトランス性能に支障をきたす虞がある。また、同発明においてはコアの接合部から磁束が外部に漏れる虞があるという欠点もある。
一方、特開２０００−１２４０４５号発明においては、１次巻線を中心に、その両側に２次巻線が配置されているため、１次巻線と第１の２次巻線、１次巻線と第２の２次巻線において、それぞれの１次巻線と２次巻線との間の結合係数の調整を行うことが難しいという欠点がある。
特開２０００−６８１３２号公報には、外形寸法が大きく幅の狭い部分に取り付ける形状としたインバータトランスとして、ボビンの巻軸の横断面の外形を長円形とし、幅が狭い側をボビンのベース部の端子が取り付けられた側面側に向けて巻軸をベース部に一体成形し、一方のコアの中央部に断面が長円形の中央脚を、四隅に外脚をそれぞれ形成し、中央脚を前記巻軸の孔に挿入し、外脚を他方のコアに突き合わせてなる構造のものが開示されている。この特開２０００−６８１３２号発明においてはコアの側面部は開放状態となっているため磁束の漏洩の虞があり、周辺の電子部品や電子機器に磁気的な悪影響を与える虞がある。
特開２０００−２４３６３３号公報には、従来の１次巻線と２次巻線とを上下に配置した構造のトランスを薄型化するためのボビンを開示している。すなわち同号公報には、ベース部の上面に一体成形された円筒状の巻軸を備えたボビンであって、該巻軸の外側の位置に該巻軸と同心円状の円筒形の第２の巻軸を設け、この第２の巻軸の上端に、外側に張り出した鍔を形成したインバータトランス用のボビンが開示されている。
この特開２０００−２４３６３３号発明は、２次巻線を中心軸側に配置し、１次巻線を外側に同心状に配置した構成を有する。しかしながら同号公報の図３にみられるように同号発明においては１次巻線は外部に露出した状態で配置されており、そのため、磁束が外部に漏れ、周辺の電子部品や電子機器に磁気的な悪影響を与える虞がある。さらにはボビンに端子部が一体的に形成されていることから巻線をボビンに巻回する際の作業性が悪いという欠点も有する。
本発明は、高さ寸法を低くして薄型化を図ったインバータトランスを提供することを目的とする。
また本発明は、部品点数が少なく、組立て容易なインバータトランスを提供することを目的とする。
更に本発明は、一対のコア同士の接合部から磁束が外部に漏れる虞のないインバータトランスを提供することを目的とする。
本発明の他の目的は、１次巻線と２次巻線との間の磁気的結合度を容易に調整することができるインバータトランスを提供することにある。
発明の開示
本発明は同一平面上に配置された１次巻線および２次巻線と、互いに対向して配置されて閉磁路を形成する一対のコアとを備えたインバータトランスであり、一対のコアの内、少なくとも一方のコアは溝形成コアとして構成される。この溝形成コアは、中央脚と外周壁とを有すると共に、該中央脚と外周壁との間に隔壁を有し、中央脚と隔壁との間および隔壁と外周壁との間にそれぞれ溝部を同心状に形成してなるものである。この溝形成コアの各溝部には、１次巻線、２次巻線がそれぞれ同心状に配置されている。
他方のコアは平板状の板状コアでも、或いは上記した溝形成コアであってもよい。すなわち、本発明において一対のコアは、溝形成コアと板状コアとの組み合わせでも或いは溝形成コア同士の組み合わせでもよい。
本発明において、２次巻線は、溝形成コアの中央脚と隔壁との間の溝部に配置され、１次巻線は隔壁と外周壁との間の溝部に２次巻線と同心状に配置されている。
溝形成コアに対向して配置される板状コアの両側面部には絶縁材料からなる端子板がそれぞれ設けられており、溝形成コアの各溝部に１次巻線、２次巻線をそれぞれ配置した後、板状コアを取り付けるに当たり、溝形成コアの外周壁が板状コアと端子板に蜜に接合するように該板状コアを取り付ける。溝形成コアと板状コアとが組み合わさった状態において、溝形成コア内部は密閉された状態となる。またこのとき板状コアと溝形成コアの中央脚および隔壁との間にギャップが形成される。
本発明において、２次巻線を主巻線と補助巻線とに分割して形成することができる。この場合、主巻線は、溝形成コアの中央脚と隔壁との間の溝部に配置され、補助巻線は隔壁を介して隔壁と外周壁との間の溝部に主巻線と同心状に配置される。また１次巻線は補助巻線が配置される溝部において、補助巻線の外側に隣接して、主巻線、補助巻線と同心状に配置される。
このように２次巻線を主巻線と補助巻線とに分割して形成する場合において、主巻線をボビンに巻回した形で溝部に配置し、補助巻線と１次巻線はそれぞれボビンレスの形態で溝部に配置することができる。この場合、ボビンは端子板に一体的に設けられていることが好ましい。
本発明は、インバータトランスにおいて一対のコアの相互間にギャップを形成する手段としてスペーサーを用いないので該トランスの高さ寸法を低くすることができる。またスペーサを不要とすることにより部品点数が減少し、組立て工程を簡略化することができ、製造時の作業性を向上することができる。
また、本発明においては、ギャップが溝形成コアの外周壁と、板状コアおよび該板状コアに取り付けられた端子板とによって閉塞されて形成されており、このためギャップ部分から磁束が外部に漏れることがない。従って本発明によれば、インバータトランスの周辺に配置される電子部品やインバータトランスを組み込んだ機器の周辺に置かれた他の電子機器に対して、漏れ磁束による磁気的な悪影響を及ぼす虞がない。
さらに、本発明は２次巻線を主巻線と補助巻線とに分割し、主巻線と補助巻線を隔壁を介して相互に分離して配置すると共に、１次巻線を補助巻線に隣接して配置したので、補助巻線の巻線数を変えることにより１次巻線と２次巻線の結合度の程度を容易に調整することができる。
発明を実施するための最良の形態
以下に、本発明について図面を参照して詳細に説明する。
図２は本発明に係るインバータトランスの外観斜視図を示し、図３は平面図、図４は底面図を示す。図５は、本発明の第１の実施態様を示す図３のＡ−Ａ線断面図である。図６は、本発明の第１の実施態様を示す底面側からみた分解斜視図を示す。また図７〜図１０は、本発明の第２の実施態様、すなわち２次巻線を主巻線と補助巻線とに分割して用いる態様を示す。図７は、本発明の第２の実施態様を示す図３のＡ−Ａ線断面図であり、図８は本発明の第２の実施態様について底面側からみた分解斜視図であり、図９は本発明においてボビンが端子板と一体化された状態を示す側面図である。図１０は本発明の第２の実施態様における電気結線図を示す。
各図において、１は本発明の溝形成コア、４は溝形成コアの外周壁、８は板状コア、１０ａ、１０ｂは絶縁材料からなる端子板をそれぞれ示し、１１ａ、１１ｂは端子板に植設された、１次巻線７または２次巻線６のリード端末を接続する外部接続端子である。外部接続端子１１ａには１次巻線７のリード端末７ａが接続されており、外部接続端子１１ｂには、リード引出し溝１２を通して２次巻線６のリード端末６ａが接続されている。本発明の溝形成コア１は、一方の面に中央脚２および外周壁４を有して開口しており、中央脚２と外周壁４との間に隔壁３が設けられている。該隔壁３と中央脚２との間に溝部６１を、該隔壁３と外周壁４との間に溝部７１を設けてある。図５、図６に示されるように溝部６１には２次巻線６が収納され、溝部７１には１次巻線７が収納される。１次巻線７のリード端末７ａは溝部７１に連接して設けられた扇状の溝５を通して外部接続端子１１ａに接続されている。このように溝部７１に連接して溝５を設けたので、１次巻線７のリード端末７ａを外部接続端子１１ａに接続する作業が容易となると共に、溝５は外部接続端子１１ａにリード端末７ａを接続するための案内通路としての機能を有する。
溝形成コア１に対向して配置される板状コア８の両側面部には絶縁材料からなる端子板１０ａ、１０ｂがそれぞれ設けられている。すなわち、板状コア８の一方の側面部は平坦形状の側面部であり、他方の側面部は窪み部１７を有する側面部となっている。平坦形状の側面部には端子板１０ａが装着され、窪み部１７を有する側面部には、該窪み部１７に対応した突出部１８を有する端子板１０ｂが装着されている。１３は突出部１８の一部を切り欠いて設けた段部である。このように板状コア８はその両側面部に装着される端子板１０ａ、１０ｂによって挟持されて該端子板１０ａ、１０ｂと結合一体化される。
板状コア８の１つの側面部に窪み部１７が設けられ、端子板１０ｂには突出部１８が設けられているため、板状コア８と端子板１０ｂとの結合に当たってその位置決めが容易となる。また端子板１０ｂの突出部１８には段部１３が設けられているため、２次巻線のリード端末６ａを外部接続端子１１ｂに接続する当たり、その作業が容易となる。
端子板１０ａ，１０ｂと結合一体化された板状コア８は、溝形成コア１の開口面と接合される。本発明における端子板１０ａ、１０ｂは、板状コア８よりも厚く構成されており、それにより溝形成コア１の中央脚２および隔壁３と板状コアとの間にギャップ９が形成されるようにしてある。端子板に形成された切欠部１５に溝形成コアの外周壁４を嵌め込み、外周壁４を端子板１０ａ、１０ｂに接合する。溝形成コア１の外周壁４は板状コア８と端子板１０ａ、１０ｂに密に接合し、溝形成コア１の内部は密閉された状態となる。そのためこの構造においては磁束が外部に漏れることがない。溝形成コア１の中央脚２および隔壁３と板状コア８との間に形成されたギャップ９を通して閉磁路が形成される。
本発明は、同一平面上に配置された１次巻線および２次巻線と、互いに対向して配置されて閉磁路を形成する一対のコアとを備えたトランスにおいて、少なくとも一方のコアは、中央脚２と外周壁４とを有すると共に、該中央脚２と外周壁４との間に隔壁３が設けられ、中央脚２と隔壁３との間および隔壁３と外周壁４との間にそれぞれ溝部６１，７１が同心状に形成され、１次巻線と２次巻線が前記コアの溝部６１，７１に同心状に配置されている構成を有する。
本発明の第１の実施態様は、図５および図６に見られるように、１次巻線７および２次巻線６は扁平でかつボビンレスの巻線として配置され、２次巻線６は、前記溝形成コア１の中央脚２と隔壁３との間の溝部６１に配置され、１次巻線７は隔壁３と外周壁４との間の溝部７１に同心状に配置されている。
本発明の第２の実施態様は、図７および図８にみられるように、２次巻線６を主巻線６ｍと補助巻線６ｓとに分割して形成され、主巻線６ｍは、溝形成コア１の中央脚２と隔壁３との間の溝部６１に配置され、補助巻線６ｓは隔壁３を介して隔壁３と外周壁４との間の溝部７１に配置されるとともに、該溝部７１において、該補助巻線６ｓの外側に隣接して、１次巻線７が同心状に配置されている。本発明において、１次巻線７および２次巻線６は扁平に形成され、ボビンレスとして配置してもよく、あるいはボビンに巻回して配置することもできる。本発明において１次巻線または２次巻線をボビンに巻回して配置する場合、第１の実施態様においては、通常、２次巻線をボビンに巻回し、１次巻線はボビンレスとして配置される。第２の実施態様においては、通常、２次巻線の主巻線６ｍをボビン１４に巻回し、補助巻線６ｓおよび１次巻線７はボビンレスとして配置され、補助巻線６ｓおよび１次巻線７は溝形成コア１に設けられた隔壁３と外周壁４との間に形成された溝部７１に、補助巻線６ｓを内側とし１次巻線７を外側として隣接して配置される。すなわち、溝形成コア１の中央脚２を中心にして主巻線６ｍ、補助巻線６ｓ、１次巻線７が順次同心状に配置されている。したがって、１次巻線７は２次巻線の一部を構成する補助巻線６ｓと強く結合し、主巻線６ｍとは弱く結合するために結合度の調整は、補助巻線６ｓの巻線数を変えることによって容易に行うことができる。
本発明においては、上記板状コアに替えて溝形成コアを使用することも出来る。この場合は、溝形成コアの中央脚および隔壁の高さを外周壁の高さよりも低くし溝形成コアの開口面を突き合わせて対向する中央脚および隔壁の間にギャップを形成し、溝形成コアの外周壁同士を接合して閉塞した状態として配置される。
本発明において、２次巻線をボビン１４に巻回して溝部６１に配置するように構成することにより巻線を溝部６１に配置するに当たり、その作業が容易となる。ボビンには、溝形成コアの中央脚２への挿入孔１６が設けられており、ボビンは挿入孔１６により中央脚２に装着して溝部６１に配置される。また図９に示したようにボビン１４と端子板１０ｂとを一体化した場合は、組立て部品数を減らすことができる上に、組立て時の作業性をより一層向上することができる。
本発明の作用を、本発明の第１の実施態様を示す図５により説明する。１次巻線７に電流を流すと、磁束は、溝形成コア１の中央脚２−外周壁４−板状コア８−ギャップ９−中央脚２を循環する点線ａで示す経路と、中央脚２−隔壁３−ギャップ９−板状コア８−ギャップ９−中央脚２を循環する点線ｂで示す経路とに分岐して発生し、磁束は２次巻線６と鎖交するので２次巻線６の両端には昇圧された電圧が発生する。このとき、２次巻線６は、１次巻線７の内側に同心状に配置されているので、磁束はすべて２次巻線と鎖交する。したがって、１次巻線と２次巻線の結合が強くなる。
第２の実施態様における磁束の循環経路は、基本的には第１の実施態様の場合と同じであるが、主巻線６ｍと補助巻線６ｓとに分割された２次巻線のそれぞれが溝形成コア１の隔壁３を介して磁気的に分離された構成となっているために、補助巻線６ｓの巻線数を変えることにより１次巻線７と２次巻き線６との電磁的結合度を容易に調整することができる。
産業上の利用可能性
本発明のインバータトランスは製造容易であり、１次巻線と２次巻線との間の磁気的結合度を容易に調整することができ、且つ一対のコア同士の接合部から磁束が外部に漏れる虞がないという利点を有するものであり、放電灯点灯用のＤＣ／ＡＣインバータ回路に使用した場合、特に利用価値が大きく、実益大なるものである。
【図面の簡単な説明】
図１は従来使用されているインバータトランスの断面図、図２は本発明のインバータトランスの外観斜視図、図３は本発明のインバータトランスの平面図、図４は本発明のインバータトランスの底面図、図５は本発明の第１の実施態様を示す図３のＡ−Ａ線断面図、図６は本発明の第１の実施態様を示す底面側からみた分解斜視図、図７は本発明の第２の実施態様を示す図３のＡ−Ａ線断面図、図８は本発明の第２の実施態様を示す底面側からみた分解斜視図、図９は本発明の第２の実施態様においてボビンと端子板とを一体化した状態を示す側面図、図１０は本発明の第２の実施態様における電気結線図である。TECHNICAL FIELD The present invention relates to an inverter transformer used in a DC / AC inverter circuit for lighting a discharge lamp. More specifically, the present invention relates to a structure of an inverter transformer that is easy to manufacture and can prevent magnetic flux from leaking to the outside from a joint portion between a pair of cores.
BACKGROUND ART Conventionally, as a transformer used in a DC / AC inverter circuit for lighting a discharge lamp used for a backlight of a liquid crystal display device, a primary winding and a secondary winding are generally made of a pair of magnetic cores. Is known in which a predetermined electromagnetic coupling is performed. In addition, such inverter transformers are required to be installed at narrow intervals and thin. As a conventional transformer of this type, for example, a primary winding is connected to an output terminal of an oscillation circuit (inverter) that generates a high frequency, and a secondary winding is connected to a discharge lamp via a ballast capacitor or the like. In addition, a structure in which the ballast capacitor portion is replaced with a choke coil is also known.
In general, a primary winding, a secondary winding, and a pair of cores that are arranged opposite to each other to form a closed magnetic circuit are provided, and electromagnetic coupling is formed by the primary winding, the secondary winding, and the core. As an inverter transformer used, for example, there is one having a structure as shown in the sectional view of FIG. In FIG. 1, reference numeral 101 denotes an E-type core, and reference numerals 701 and 601 denote a primary winding and a secondary winding wound around the side leg 103 of the E-type core, respectively.
Reference numeral 201 denotes an I-type core disposed opposite to the E-type core 101, between the central leg 102 of the E-type core 101 and the I-type core 201, and between the side legs 103 of the E-type core and the I-type core 201. A gap 202 is formed between the two. A spacer 203 made of an insulating material is usually sandwiched in the gap between the side leg 103 of the E type core and the I type core 201, and the E type core 101 and the I type core 201 form a closed magnetic circuit through the spacer 203. is doing. In the transformer having such a structure, the coupling resistance between the primary winding 701 and the secondary winding 601 can be adjusted by changing the magnetic resistance of the closed magnetic circuit by changing the thickness of the spacer 203. However, in order to adjust the degree of coupling, it is necessary to prepare spacers of various thicknesses and use them properly depending on the degree of coupling desired, which increases the number of parts and makes the assembly work complicated. Further, since the spacer has a thickness, the height of the transformer cannot be lowered, and it is difficult to produce a thin one. Further, in the case of the above structure, there is a risk that magnetic flux leaks from the portion of the spacer 203 to adversely affect the electronic components and peripheral devices close to the transformer.
Japanese Patent Laid-Open No. 10-335157 discloses a pair of cores forming a closed magnetic circuit, a primary winding, and a secondary winding as an inverter transformer that facilitates adjustment of the coupling coefficient between the primary winding and the secondary winding. The lower core of the pair of cores is composed of a rectangular flat plate portion and two columnar protrusions integrally formed at both ends thereof, and each protrusion has Disclosed is a structure in which a bobbin winding shaft is attached, a primary winding and a secondary winding are wound on two winding shafts, respectively, and a part of the primary winding is wound on the secondary winding. ing.
JP 2000-124045 discloses a multi-lamp inverter transformer in which first and second secondary windings having the same number of turns are arranged at symmetrical positions around the primary winding, A plurality of outputs can be obtained by one inverter transformer in which the primary winding and the first secondary winding, and the primary winding and the second secondary winding are electromagnetically coupled with substantially the same degree of coupling. What is configured as described above is disclosed.
In any of these inventions, the primary winding and the secondary winding are arranged in parallel. In the invention of Japanese Patent Laid-Open No. 10-335157, since a part of the primary winding is wound on the secondary winding, the low-voltage side winding, that is, the lead wire of the primary winding is provided. As a result, the transformer performance may be hindered unless the insulation of each winding is increased. In addition, in the present invention, there is a drawback that magnetic flux may leak to the outside from the joint portion of the core.
On the other hand, in the invention of Japanese Patent Laid-Open No. 2000-124045, since the secondary winding is arranged on both sides of the primary winding, the primary winding, the first secondary winding, and the primary winding. The line and the second secondary winding have the disadvantage that it is difficult to adjust the coupling coefficient between the respective primary and secondary windings.
Japanese Patent Laid-Open No. 2000-68132 discloses an inverter transformer having a shape that is attached to a narrow portion having a large outer dimension, and the outer shape of the cross section of the bobbin winding shaft is an oval, and the narrow side is the base portion of the bobbin. The winding shaft is formed integrally with the base portion toward the side surface to which the terminal is attached, the central leg having an elliptical cross section is formed at the center of one core, and the outer legs are formed at the four corners. A structure having a structure in which an outer leg is butted against the other core is disclosed. In this Japanese Patent Application Laid-Open No. 2000-68132, the side surface of the core is in an open state, so there is a risk of leakage of magnetic flux, and there is a risk of adversely affecting the surrounding electronic components and electronic devices.
Japanese Laid-Open Patent Publication No. 2000-243633 discloses a bobbin for thinning a transformer having a structure in which a conventional primary winding and secondary winding are vertically arranged. That is, the publication discloses a bobbin provided with a cylindrical winding shaft integrally formed on the upper surface of a base portion, and a cylindrical second concentric with the winding shaft at a position outside the winding shaft. A bobbin for an inverter transformer is disclosed in which a winding shaft is provided and a flange protruding outward is formed at the upper end of the second winding shaft.
The invention of Japanese Patent Laid-Open No. 2000-243633 has a configuration in which the secondary winding is disposed on the central axis side and the primary winding is disposed concentrically on the outside. However, as shown in FIG. 3 of the same publication, in the invention of the same publication, the primary winding is disposed so as to be exposed to the outside, so that the magnetic flux leaks to the outside, and the surrounding electronic components and electronic equipment are magnetically affected. Adverse effects may occur. Furthermore, since the terminal portion is integrally formed on the bobbin, there is a disadvantage that workability when winding the winding around the bobbin is poor.
SUMMARY OF THE INVENTION An object of the present invention is to provide an inverter transformer that is reduced in height and reduced in thickness.
Another object of the present invention is to provide an inverter transformer which has a small number of parts and can be easily assembled.
Furthermore, an object of the present invention is to provide an inverter transformer in which magnetic flux does not leak to the outside from a joint portion between a pair of cores.
Another object of the present invention is to provide an inverter transformer capable of easily adjusting the degree of magnetic coupling between a primary winding and a secondary winding.
DISCLOSURE OF THE INVENTION The present invention is an inverter transformer comprising a primary winding and a secondary winding arranged on the same plane, and a pair of cores arranged opposite to each other to form a closed magnetic circuit. At least one of the cores is configured as a groove-forming core. The groove-forming core has a central leg and an outer peripheral wall, and has a partition wall between the central leg and the outer peripheral wall, and has groove portions between the central leg and the partition wall and between the partition wall and the outer peripheral wall. It is formed concentrically. In each groove portion of the groove forming core, a primary winding and a secondary winding are concentrically arranged.
The other core may be a flat plate-shaped core or the groove-forming core described above. That is, in the present invention, the pair of cores may be a combination of a groove-forming core and a plate-like core or a combination of groove-forming cores.
In the present invention, the secondary winding is disposed in a groove portion between the central leg of the groove-forming core and the partition wall, and the primary winding is concentric with the secondary winding in the groove portion between the partition wall and the outer peripheral wall. Has been placed.
Terminal plates made of an insulating material are respectively provided on both side portions of the plate-like core arranged opposite to the groove-forming core, and a primary winding and a secondary winding are arranged in each groove portion of the groove-forming core. After that, when attaching the plate-like core, the plate-like core is attached so that the outer peripheral wall of the groove-forming core is joined to the plate-like core and the terminal plate. In the state where the groove-forming core and the plate-like core are combined, the inside of the groove-forming core is sealed. At this time, a gap is formed between the plate-shaped core and the central leg of the groove-forming core and the partition wall.
In the present invention, the secondary winding can be divided into a main winding and an auxiliary winding. In this case, the main winding is disposed in the groove between the central leg of the groove-forming core and the partition, and the auxiliary winding is concentrically with the main winding in the groove between the partition and the outer peripheral wall via the partition. Be placed. Further, the primary winding is disposed concentrically with the main winding and the auxiliary winding adjacent to the outside of the auxiliary winding in the groove portion where the auxiliary winding is disposed.
Thus, when the secondary winding is divided into the main winding and the auxiliary winding, the main winding is wound around the bobbin and arranged in the groove, and the auxiliary winding and the primary winding are Each can be arranged in the groove in the form of a bobbinless. In this case, the bobbin is preferably provided integrally with the terminal board.
Since the present invention does not use a spacer as a means for forming a gap between a pair of cores in an inverter transformer, the height dimension of the transformer can be reduced. Further, by eliminating the need for spacers, the number of parts can be reduced, the assembly process can be simplified, and workability during manufacturing can be improved.
Further, in the present invention, the gap is formed by being closed by the outer peripheral wall of the groove-forming core, the plate-like core, and the terminal plate attached to the plate-like core. There is no leakage. Therefore, according to the present invention, there is no possibility of adversely affecting the magnetic components due to the leakage magnetic flux to the electronic components arranged around the inverter transformer and other electronic devices placed around the equipment incorporating the inverter transformer. .
Further, according to the present invention, the secondary winding is divided into a main winding and an auxiliary winding, the main winding and the auxiliary winding are separated from each other via a partition wall, and the primary winding is arranged as an auxiliary winding. Since it is arranged adjacent to the wire, the degree of coupling between the primary winding and the secondary winding can be easily adjusted by changing the number of auxiliary windings.
BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail with reference to the drawings.
2 is an external perspective view of the inverter transformer according to the present invention, FIG. 3 is a plan view, and FIG. 4 is a bottom view. 5 is a cross-sectional view taken along line AA of FIG. 3 showing the first embodiment of the present invention. FIG. 6 shows an exploded perspective view of the first embodiment of the present invention as seen from the bottom side. 7 to 10 show a second embodiment of the present invention, that is, a mode in which the secondary winding is divided into a main winding and an auxiliary winding. 7 is a cross-sectional view taken along line AA of FIG. 3 showing the second embodiment of the present invention, and FIG. 8 is an exploded perspective view of the second embodiment of the present invention as seen from the bottom side. FIG. 4 is a side view showing a state in which the bobbin is integrated with the terminal board in the present invention. FIG. 10 shows an electrical connection diagram in the second embodiment of the present invention.
In each figure, 1 is a groove-forming core of the present invention, 4 is an outer peripheral wall of the groove-forming core, 8 is a plate-like core, 10a and 10b are terminal plates made of an insulating material, and 11a and 11b are planted on the terminal plate. An external connection terminal for connecting a lead terminal of the primary winding 7 or the secondary winding 6 provided. The lead terminal 7a of the primary winding 7 is connected to the external connection terminal 11a, and the lead terminal 6a of the secondary winding 6 is connected to the external connection terminal 11b through the lead extraction groove 12. The groove-forming core 1 of the present invention is opened with a central leg 2 and an outer peripheral wall 4 on one surface, and a partition wall 3 is provided between the central leg 2 and the outer peripheral wall 4. A groove portion 61 is provided between the partition wall 3 and the central leg 2, and a groove portion 71 is provided between the partition wall 3 and the outer peripheral wall 4. As shown in FIGS. 5 and 6, the secondary winding 6 is stored in the groove 61, and the primary winding 7 is stored in the groove 71. The lead terminal 7 a of the primary winding 7 is connected to the external connection terminal 11 a through the fan-shaped groove 5 provided to be connected to the groove 71. Since the groove 5 is provided in such a manner as being connected to the groove portion 71, the work of connecting the lead terminal 7a of the primary winding 7 to the external connection terminal 11a is facilitated, and the groove 5 is connected to the external connection terminal 11a. It has a function as a guide passage for connecting 7a.
Terminal plates 10a and 10b made of an insulating material are respectively provided on both side portions of the plate-like core 8 disposed to face the groove-forming core 1. That is, one side surface portion of the plate-shaped core 8 is a flat side surface portion, and the other side surface portion is a side surface portion having a recess portion 17. A terminal plate 10 a is attached to the flat side surface portion, and a terminal plate 10 b having a protrusion 18 corresponding to the recess portion 17 is attached to the side surface portion having the recess portion 17. Reference numeral 13 denotes a stepped portion provided by cutting out a part of the protruding portion 18. In this way, the plate-like core 8 is sandwiched and integrated with the terminal plates 10a and 10b by being sandwiched by the terminal plates 10a and 10b mounted on both side portions thereof.
Since the concave portion 17 is provided in one side surface portion of the plate-shaped core 8 and the protruding portion 18 is provided in the terminal plate 10b, the positioning is facilitated when the plate-shaped core 8 and the terminal plate 10b are coupled. . Further, since the protruding portion 18 of the terminal plate 10b is provided with the stepped portion 13, the work is facilitated when the lead terminal 6a of the secondary winding is connected to the external connection terminal 11b.
The plate-like core 8 joined and integrated with the terminal plates 10 a and 10 b is joined to the opening surface of the groove-forming core 1. The terminal plates 10a and 10b in the present invention are configured to be thicker than the plate-like core 8, so that a gap 9 is formed between the central leg 2 of the groove-forming core 1 and the partition wall 3 and the plate-like core. It is. The outer peripheral wall 4 of the groove-forming core is fitted into the notch 15 formed in the terminal plate, and the outer peripheral wall 4 is joined to the terminal plates 10a and 10b. The outer peripheral wall 4 of the groove-forming core 1 is closely joined to the plate-like core 8 and the terminal plates 10a and 10b, and the inside of the groove-forming core 1 is sealed. Therefore, magnetic flux does not leak outside in this structure. A closed magnetic path is formed through the center leg 2 of the groove-forming core 1 and the gap 9 formed between the partition wall 3 and the plate-like core 8.
The present invention provides a transformer comprising a primary winding and a secondary winding arranged on the same plane, and a pair of cores arranged opposite to each other to form a closed magnetic circuit, wherein at least one of the cores is In addition to the central leg 2 and the outer peripheral wall 4, a partition wall 3 is provided between the central leg 2 and the outer peripheral wall 4, and between the central leg 2 and the partition wall 3 and between the partition wall 3 and the outer peripheral wall 4. Each of the groove portions 61 and 71 is formed concentrically, and the primary winding and the secondary winding are concentrically arranged in the groove portions 61 and 71 of the core.
In the first embodiment of the present invention, as seen in FIGS. 5 and 6, the primary winding 7 and the secondary winding 6 are arranged as flat and bobbinless windings, and the secondary winding 6 The primary winding 7 is concentrically disposed in the groove 71 between the partition wall 3 and the outer peripheral wall 4, and is disposed in the groove portion 61 between the central leg 2 of the groove-forming core 1 and the partition wall 3.
As shown in FIGS. 7 and 8, the second embodiment of the present invention is formed by dividing the secondary winding 6 into a main winding 6m and an auxiliary winding 6s. The auxiliary winding 6s is disposed in the groove portion 71 between the partition wall 3 and the outer peripheral wall 4 through the partition wall 3, and is disposed in the groove portion 61 between the central leg 2 of the groove forming core 1 and the partition wall 3. In the groove portion 71, the primary winding 7 is disposed concentrically adjacent to the outside of the auxiliary winding 6s. In the present invention, the primary winding 7 and the secondary winding 6 are formed flat and may be disposed as a bobbin-less, or may be disposed by being wound around a bobbin. In the present invention, when the primary winding or the secondary winding is arranged around the bobbin, in the first embodiment, the secondary winding is usually wound around the bobbin and the primary winding is arranged as a bobbin-less. Is done. In the second embodiment, the main winding 6m of the secondary winding is usually wound around the bobbin 14, the auxiliary winding 6s and the primary winding 7 are arranged as bobbinless, and the auxiliary winding 6s and the primary winding are arranged. The wire 7 is disposed adjacent to a groove portion 71 formed between the partition wall 3 and the outer peripheral wall 4 provided in the groove forming core 1 with the auxiliary winding 6s as the inner side and the primary winding 7 as the outer side. That is, the main winding 6m, the auxiliary winding 6s, and the primary winding 7 are sequentially arranged concentrically around the central leg 2 of the groove forming core 1. Therefore, the primary winding 7 is strongly coupled to the auxiliary winding 6s constituting a part of the secondary winding and is weakly coupled to the main winding 6m. This can be done easily by changing the number of lines.
In the present invention, a groove-forming core can be used instead of the plate-like core. In this case, the height of the central leg and the partition wall of the groove forming core is made lower than the height of the outer peripheral wall, the gap is formed between the opposing central leg and the partition wall by facing the opening surface of the groove forming core. The outer peripheral walls are joined and closed.
In the present invention, the secondary winding is wound around the bobbin 14 and disposed in the groove portion 61, whereby the work is facilitated when the winding is disposed in the groove portion 61. The bobbin is provided with an insertion hole 16 into the central leg 2 of the groove-forming core, and the bobbin is attached to the central leg 2 through the insertion hole 16 and disposed in the groove 61. Further, when the bobbin 14 and the terminal board 10b are integrated as shown in FIG. 9, the number of parts to be assembled can be reduced and the workability at the time of assembly can be further improved.
The operation of the present invention will be described with reference to FIG. 5 showing the first embodiment of the present invention. When a current is passed through the primary winding 7, the magnetic flux passes through the center leg 2 of the groove-forming core 1, the outer peripheral wall 4, the plate-like core 8, the gap 9, and the path indicated by the dotted line a that circulates through the center leg 2. 2-partition 3-gap 9-plate core 8-gap 9-branch to the path indicated by the dotted line b circulating through the center leg 2, and the magnetic flux is linked to the secondary winding 6, so secondary winding A boosted voltage is generated at both ends of the line 6. At this time, since the secondary winding 6 is disposed concentrically inside the primary winding 7, all the magnetic fluxes are linked to the secondary winding. Accordingly, the coupling between the primary winding and the secondary winding is strengthened.
The magnetic flux circulation path in the second embodiment is basically the same as in the first embodiment, but each of the secondary windings divided into the main winding 6m and the auxiliary winding 6s Since the structure is magnetically separated through the partition wall 3 of the groove-forming core 1, the electromagnetic force between the primary winding 7 and the secondary winding 6 can be changed by changing the number of auxiliary windings 6s. The degree of mechanical coupling can be easily adjusted.
Industrial Applicability The inverter transformer of the present invention is easy to manufacture, the degree of magnetic coupling between the primary winding and the secondary winding can be easily adjusted, and a pair of cores are joined together. This has the advantage that the magnetic flux does not leak to the outside from the part, and when used in a DC / AC inverter circuit for lighting a discharge lamp, the utility value is particularly great and the profit is large.
[Brief description of the drawings]
1 is a cross-sectional view of a conventional inverter transformer, FIG. 2 is an external perspective view of the inverter transformer of the present invention, FIG. 3 is a plan view of the inverter transformer of the present invention, and FIG. 4 is a bottom view of the inverter transformer of the present invention. 5 is a cross-sectional view taken along line AA of FIG. 3 showing the first embodiment of the present invention, FIG. 6 is an exploded perspective view of the first embodiment of the present invention viewed from the bottom side, and FIG. 7 is the present invention. 3 is a sectional view taken along line AA in FIG. 3 showing the second embodiment of the present invention, FIG. 8 is an exploded perspective view showing the second embodiment of the present invention from the bottom side, and FIG. 9 is the second embodiment of the present invention. FIG. 10 is a side view showing a state in which the bobbin and the terminal plate are integrated in FIG. 10, and FIG.

Claims

In a transformer comprising a primary winding and a secondary winding arranged on the same plane, and a pair of cores arranged opposite to each other to form a closed magnetic circuit,
At least one of the cores forming the closed magnetic path has a central leg and an outer peripheral wall, and has a partition wall between the central leg and the outer peripheral wall, between the central leg and the partition wall, and between the partition wall and the outer peripheral wall. A groove-forming core formed by concentrically forming a groove between each of the two, a secondary winding is disposed in the groove formed between the central leg and the partition, and the partition and the outer peripheral wall A primary winding is disposed in the groove formed between the core and a gap is formed between the core disposed opposite to the groove forming core and the central leg and the partition wall of the groove forming core. An inverter transformer characterized by

2. The pair of cores that are arranged to face each other and form a closed magnetic circuit include a groove-forming core and a plate-like core that is arranged to face the groove-forming core. Inverter transformer.

The inverter transformer according to claim 2, wherein terminal plates made of an insulating material are provided on both side surfaces of the plate-like core disposed to face the groove-forming core.

4. The inverter transformer according to claim 3, wherein the outer peripheral wall of the groove-forming core is closely joined to the plate-like core and the terminal plate, and the inside of the groove-forming core is sealed.

The secondary winding is divided into a main winding and an auxiliary winding, and the main winding is disposed in a groove portion between the central leg of the groove forming core and the partition, and the auxiliary winding is interposed via the partition. It is arranged concentrically with the main winding in the groove between the partition wall and the outer peripheral wall, and the primary winding is concentric with the main winding and the auxiliary winding adjacent to the outside of the auxiliary winding in the groove. The inverter transformer according to claim 1, wherein the inverter transformer is arranged in a shape.

The secondary winding is formed by dividing it into a main winding and an auxiliary winding, and the main winding is wound around the bobbin and arranged in the groove between the central leg of the groove forming core and the partition wall. The winding is disposed in a groove between the partition wall and the outer peripheral wall concentrically with the main winding through the partition wall in the form of a bobbin, in which the primary winding is adjacent to the outside of the auxiliary winding. 2. The inverter transformer according to claim 1, wherein the inverter transformer is concentrically arranged with a main winding and an auxiliary winding in a bobbin-less form.

The inverter transformer according to claim 6, wherein the bobbin is integrally provided on the terminal board.