JP2004234885A

JP2004234885A - Screw terminal structure

Info

Publication number: JP2004234885A
Application number: JP2003018832A
Authority: JP
Inventors: Hiroshi Yokota; 浩横田
Original assignee: Matsushita Electric Works Ltd
Current assignee: Panasonic Electric Works Co Ltd
Priority date: 2003-01-28
Filing date: 2003-01-28
Publication date: 2004-08-19

Abstract

<P>PROBLEM TO BE SOLVED: To provide a screw terminal structure capable of effectively preventing the fall of a screw terminal and free from damage to the screw terminal and a terminal pedestal. <P>SOLUTION: The screw terminal structure is provided with a screw terminal 9, a terminal pedestal 13 on which the screw terminal 9 is screwed down through a terminal plate 12, and a terminal pedestal cover 14 arranged surrounding the terminal pedestal 13. The terminal pedestal cover 14 has a partition wall 16 covering an outside part in the proceeding and receding direction of the screw terminal 9, and the partition wall 16 has a through-hole 17 trough which the screw terminal 9 can pass while the terminal plate 12 can not pass, and at the same time, a distance from the inner face of the partition wall 16 to the terminal pedestal 13 is set almost the same as a length from the tip of a screw of the screw terminal 9 to the outer face of the terminal plate 12. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

【０００１】
【発明の属する技術分野】
本発明はネジ端子構造に係り、特には、検知器等で利用されるネジ端子構造に関する。
【０００２】
【従来の技術】
従来から、火災の発生や人の存在等を検知する検知器のうちには電池を電源としたものがあり、その一例としては、図７で開放状態を示すような検知器５１が知られている。この検知器５１は例えば火災報知器であり、一端部同士が互いに連結されたカバー５２を具備してなるベース本体５３は、その底面部そのものが取付ネジを使用したうえで建物の天井面や壁面等のような取付面に固定される。
【０００３】
そして、ベース本体５３の内部には、電池５４を収納する電池ホルダや、検知手段として機能する電子回路部品等を搭載した回路基板５５，５６が設けられており、ベース本体５３の開放面は開閉自在なカバー５２により閉塞されている。また、ベース本体５３内には、警報ブザー等のような外部機器との連絡用信号線等である電線５７が引き込まれており、電線引込用の開口５８を通って引き込まれた電線５７の内端部は、ベース本体５３の底面部に配置されたネジ端子５９を使用して回路基板５６に固定されている。
【０００４】
検知器５１におけるネジ端子構造は、図８で拡大して示すように、ネジ端子５９と、このネジ端子５９のネジ部に外嵌された端子板６０と、ネジ端子５９が端子板６０を挟んで螺合される端子台６１、つまり、ネジ端子５９のネジ部（雄ネジ）を螺合させるためのネジ孔（雌ネジ）が形成された端子台６１とを備えている。そして、ここでの端子台６１は回路基板５６で支持されたうえ、電子回路部品等と接続されている。なお、この種のネジ端子構造を有する検知器５１の他の具体例としては、既に各種のものが周知となっている（例えば、特許文献１）。
【０００５】
【特許文献１】
特開昭６３−２７６８８０号公報
【０００６】
【発明が解決しようとする課題】
ところで、前記従来構成とされた検知器５１のネジ端子構造にあっては、端子板６０と端子台６１との間に電線５７の内端部を配置したうえでネジ端子５９を締め付けて電線５７を拘束する一方、このネジ端子５９を緩めて電線５７の内端部を端子板６０及び端子台６１間から離脱させることが行われる。このとき、緩められたネジ端子５９が端子台６１から脱落するのでは、紛失の恐れがあるばかりか、電線５７の着脱作業に支障をきたしてしまう。
【０００７】
そこで、従来のネジ端子構造においては、緩められたネジ端子５９が端子台６１から脱落するのを防止するため、図８で示すように、端子台６１に螺合されたネジ端子５９のネジ部の先端をスピニング加工やカシメ加工によって拡張変形させることが実行されている。しかしながら、狭隘なスペースしか確保できない状態下でネジ端子５９のネジ部を拡張変形させる作業は大変に困難であり、コストアップを招くことが避けられなかった。
【０００８】
また、ネジ部が拡張変形させられたネジ端子５９を緩める場合には、その拡張変形部分が端子台６１のネジ孔と螺合して損傷させるばかりか、ネジ部の拡張変形部分がネジ孔と強固に螺合しあっているにも拘わらず、ネジ端子５９を緩めるために過度の外力を加える結果としてネジ端子５９そのものを損傷してしまうことも起こっていた。
【０００９】
本発明はこのような不都合に鑑みて創案されたものであって、ネジ端子の脱落を有効に防止することが可能であり、しかも、ネジ端子及び端子台の損傷を招くことがないネジ端子構造の提供を目的としている。
【００１０】
【課題を解決するための手段】
請求項１に記載の発明に係るネジ端子構造は、ネジ端子と、該ネジ端子が端子板を挟んで螺合される端子台と、該端子台を取り囲んで配置される端子台カバーとを備えてなるものであって、前記端子台カバーは前記ネジ端子の進退方向の外方を覆う隔壁を有しており、かつ、該隔壁には前記ネジ端子の挿通を許容する一方で前記端子板の挿通を不可とする貫通孔が形成されているとともに、前記隔壁の内面から前記端子台の外面までの間隔は前記ネジ端子のネジ部の先端から前記端子板の外面までの長さと略同一に設定されていることを特徴とする。
【００１１】
請求項２に記載の発明に係るネジ端子構造は請求項１に記載したものであり、前記ネジ端子の頭部は、前記隔壁の厚みよりも十分に大きい高さを有していることを特徴とする。
【００１２】
請求項３に記載の発明に係るネジ端子構造は請求項１または請求項２に記載したものであり、前記ネジ端子のネジ部の先端と前記端子台に形成されたネジ孔との各々には、互いに当接しあう面取り部が形成されていることを特徴とする。
【００１３】
請求項４に記載の発明に係るネジ端子構造は請求項１〜請求項３のいずれかに記載したものであり、前記ネジ端子のネジ部の先端には、前記ネジ孔よりも小径の突起部が形成されていることを特徴とする。
【００１４】
【発明の実施の形態】
図１は本実施の形態に係る検知器の全体構造を分解して示す斜視図、図２はベース本体のネジ端子構造を示す要部斜視図であり、図３は検知器のネジ端子構造のみを拡大して示す断面図である。また、図４は検知器のネジ端子構造を拡大して示す要部説明図、図５は変形例に係るネジ端子構造を拡大して示す要部説明図であり、図６は検知器が備えているカバー本体の全体構造を示す斜視図である。
【００１５】
本実施の形態に係る検知器１は例えば火災報知器であり、図１で示すように、建物の天井面や壁面等のような取付面に取り付けて固定されるベース本体２と、回動操作によりベース本体２と着脱自在に連結されるカバー本体３とを備えている。ここでのベース本体２は絶縁性合成樹脂等からなる略円形状の有底筒形容器であり、その底面部の外周縁沿いには所定厚みの周縁壁４が所定高さで立設されている。
【００１６】
このベース本体２は、底面部の開口５を挿通する取付用ネジにより底面部の背面が取付面に当接した状態で固定されるものであり、その底面部の表面には、警報ブザー等である外部機器との連絡用信号線等のような電線６を収納するための配線スペース７が設けられている。そして、ベース本体２の周方向に沿う所定位置には電線引込用の開口８が形成されており、外部から開口８を通って配線スペース７へと引き込まれた電線６の内端部は、ベース本体２の底面部に配置されたネジ端子９を使用して回路基板１０（図２（Ｂ）参照）に固定される。
【００１７】
また、このベース本体２の底面部に立設された周縁壁４の周方向に沿う所定位置、つまり、互いに対称となる位置それぞれにはカバー係止片１１が形成されており、これら一対のカバー係止片１１は底面部の内方へと突出している。なお、本実施の形態では、開口５，８及びカバー係止片１１が対応する位置ごとに設けられているが、このような必然性はなく、互いに異なる位置に設けられていてもよい。
【００１８】
この検知器１におけるネジ端子構造は、図２（Ａ）で組立状態を示し、かつ、図２（Ｂ）で分解状態を示すように、ネジ端子９と、このネジ端子９のネジ部に外嵌された端子板１２と、ネジ端子９が端子板１２を挟み込んで螺合される端子台１３と、この端子台１３を取り囲んで配置される端子台カバー１４とを備えている。このとき、ネジ端子９のネジ部（雄ネジ）を螺合させるためのネジ孔（雌ネジ）が形成された絶縁性合成樹脂製の端子台１３は回路基板１０に固定される一方、端子台カバー１４は端子台１３に螺合させられたネジ端子９及び端子板１２をも取り囲んだ状態で回路基板１０に外嵌されている。
【００１９】
すなわち、このネジ端子構造では、端子板１２と端子台１３との間に電線６の内端部を配置したうえでネジ端子９を締め付けて電線６を拘束する一方、このネジ端子９を緩めるのに伴って電線６の内端部を端子板１２及び端子台１３間から離脱させることが行われる。なお、回路基板１０にはいわゆる鰐口構造を有する一対の接続端子１５も配設されており、各接続端子１５はネジ端子９のそれぞれと個別的に導通している。
【００２０】
さらに、この際、図３（Ａ）でネジ端子を締め付けた状態を示し、図３（Ｂ）及び図４でネジ端子を緩めた状態を示すように、端子台カバー１４はネジ端子９の進退方向の外方を覆う隔壁１６を有しており、この隔壁１６にはネジ端子９の頭部の挿通をも許容する一方で端子板１２の挿通を不可とする貫通孔１７が形成されている。また、このとき、隔壁１６の内面から前記端子台１３の外面までの間隔は、ネジ端子９のネジ部の先端から端子板１２の外面までの長さと略同一に設定されている。
【００２１】
本実施の形態に係るネジ端子構造を採用している場合、図４で示すように、電線６の内端部を端子板１２及び端子台１３間から離脱させるためにネジ端子９を緩めても、緩められたネジ端子９のネジ部に外嵌された端子板１２が端子台カバー１４の隔壁１６に形成された貫通孔１７を挿通し得ないため、このネジ端子９が端子台１３から脱落することはなくなる。また、隔壁１６の内面から前記端子台１３の外面までの間隔と、ネジ端子９のネジ部の先端から端子板１２の外面までの長さとが略同一とされているので、ネジ端子９を緩めていくと、端子台カバー１４の隔壁１６に端子板１２が当接した時点では、ネジ端子９のネジ部が端子台１３のネジ孔から確実に退出していることになり、ネジ部やネジ孔の損傷は起こり得ない。
【００２２】
ところで、以上説明したネジ端子構造のみに限られることはなく、図５で示すようなネジ端子構造、つまり、変形例に係る各種のネジ端子構造を採用することも可能である。まず、図５（Ａ）で示すように、ネジ端子９の頭部は、端子カバー１４の隔壁１６が有する厚みよりも十分に大きい高さを有していることが好ましい。このような構造であれば、隔壁１６の内面から前記端子台１３の外面までの間隔が、ネジ端子９のネジ部の先端から端子板１２の外面までの長さよりも多少大きくても、緩め続けることによってネジ端子９のネジ部を端子台１３のネジ孔から確実に退出することとなる。
【００２３】
また、図５（Ｂ）で示すように、ネジ端子９のネジ部の先端と、端子台１３に形成されたネジ孔との各々に対し、互いに当接しあう面取り部を形成しておいてもよい。さらに、図５（Ｃ）で示すように、ネジ端子９のネジ部の先端に対し、ネジ孔よりも小径の突起部１９を形成してもよい。これらの構造であれば、ネジ端子９のネジ部が端子台１３のネジ孔に導入され易くなる。すなわち、変形例に係るネジ端子構造を採用している場合には、構成部品それぞれの寸法精度が多少粗くとも構わず、構成部品の製作コストを低減し得る。
【００２４】
一方、検知器１が備えているカバー本体３は、絶縁性合成樹脂等からなる略円形状の中空容器であり、ベース本体２よりも若干大径とされている。このカバー本体３には検知手段となる各種の電子回路部品等が内蔵されており、図６で示すように、ベース本体２と対面するカバー本体３の背面には、交換可能な電源供給用の電池２１が着脱自在として収納されている。
【００２５】
そして、このカバー本体３には、ベース本体２の接続端子１５で挟持されるのに伴って個別的に導通する一対の接続接点２２が設けられており、これらの接続接点２２は検知手段である各種の電子回路部品と導通している。また、カバー本体３の周方向に沿う所定位置には、ベース本体２の周縁壁４に形成されたカバー係止片１１と係合しあう一対のベース係止片２３が形成されている。
【００２６】
従って、ベース本体２と対向させられたカバー本体３を回動操作すると、カバー本体３のベース係止片２３とベース本体２のカバー係止片１１とが係合しあう結果、カバー本体３はベース本体２に対して連結される。このとき、接続接点２２のそれぞれは各接続端子１５で挟持されて導通することになり、電池２１を収納しているカバー本体３の開放面はベース本体２でもって閉塞される。なお、図中の符号２４は引き紐、２５は警報音停止ボタンであり、この警報音停止ボタン２５は動作確認時や警報停止時に使用される。
【００２７】
なお、本実施の形態に係る検知器１が火災報知器に限定されず、人の存在等を検知するものであってもよい。また、本実施の形態で説明したネジ端子構造の適用範囲が検知器１のみに限られることはなく、他の装置や機器に対しても適用可能となることは勿論である
【００２８】
【発明の効果】
請求項１記載の発明に係るネジ端子構造であれば、ネジ端子のネジ部に外嵌された端子板が端子台カバーの隔壁に形成された貫通孔を挿通し得ないため、緩められたネジ端子が端子台から脱落することはなくなるという効果が得られる。また、隔壁の内面から端子台の外面までの間隔と、ネジ端子のネジ部の先端から端子板の外面までの長さとが略同一であるため、ネジ端子を緩めた結果として端子板が隔壁に当接した時点では、ネジ端子のネジ部が端子台から確実に退出していることになり、ネジ端子や端子台の損傷が起こらないという利点も確保される。
【００２９】
請求項２〜請求項４のいずれかに記載したネジ端子構造であれば、ネジ端子の脱落を有効に防止することが可能であり、しかも、ネジ端子及び端子台の損傷を招くことがないばかりか、ネジ端子構造の構成部品それぞれの寸法精度が多少粗くとも何ら差し支えなく、これら構成部品の製作コストを低減することができるという効果が得られる。
【図面の簡単な説明】
【図１】本実施の形態に係る検知器の全体構造を分解して示す斜視図である。
【図２】本実施の形態に係る検知器が備えるベース本体のネジ端子構造を示す要部斜視図である。
【図３】本実施の形態に係る検知器のネジ端子構造を拡大して示す断面図である。
【図４】本実施の形態に係る検知器のネジ端子構造を拡大して示す要部説明図である。
【図５】変形例に係るネジ端子構造を拡大して示す要部説明図である。
【図６】本実施の形態に係る検知器が備えているカバー本体の全体構造を示す斜視図である。
【図７】従来の形態に係る検知器の全体構造を示す斜視図である。
【図８】従来の形態に係る検知器のネジ端子構造を拡大して示す要部説明図である。
【符号の説明】
１検知器
９ネジ端子
１２端子板
１３端子台
１４端子台カバー
１６隔壁
１７貫通孔
１９突起部[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a screw terminal structure, and more particularly, to a screw terminal structure used in a detector or the like.
[0002]
[Prior art]
2. Description of the Related Art Conventionally, some of the detectors that detect the occurrence of a fire, the presence of a person, and the like use a battery as a power supply. As an example, a detector 51 that indicates an open state in FIG. 7 is known. I have. The detector 51 is, for example, a fire alarm, and a base body 53 having a cover 52 having one end connected to each other is mounted on a ceiling surface or a wall surface of a building on the bottom surface itself using mounting screws. And so on.
[0003]
Further, inside the base body 53, there are provided a battery holder for housing the battery 54, and circuit boards 55 and 56 on which electronic circuit components and the like functioning as detecting means are mounted. It is closed by a flexible cover 52. Also, in the base body 53, an electric wire 57, such as a signal line for communication with an external device such as an alarm buzzer, is drawn in, and among the electric wires 57 drawn through the wire drawing opening 58, The end is fixed to the circuit board 56 using a screw terminal 59 arranged on the bottom of the base body 53.
[0004]
The screw terminal structure of the detector 51 is, as shown in an enlarged manner in FIG. 8, a screw terminal 59, a terminal plate 60 externally fitted to a screw portion of the screw terminal 59, and the screw terminal 59 sandwiching the terminal plate 60. , That is, a terminal block 61 in which a screw hole (female screw) for screwing a screw portion (male screw) of the screw terminal 59 is formed. The terminal block 61 is supported by a circuit board 56 and connected to electronic circuit components and the like. As other specific examples of the detector 51 having this kind of screw terminal structure, various types are already known (for example, Patent Document 1).
[0005]
[Patent Document 1]
JP-A-63-276880
[Problems to be solved by the invention]
By the way, in the screw terminal structure of the detector 51 having the conventional configuration, the inner end of the electric wire 57 is disposed between the terminal plate 60 and the terminal block 61, and the screw terminal 59 is tightened. While the screw terminal 59 is loosened, the inner end of the electric wire 57 is detached from between the terminal plate 60 and the terminal block 61. At this time, if the loosened screw terminals 59 fall off from the terminal block 61, they may not only be lost but also hinder the work of attaching and detaching the electric wires 57.
[0007]
Therefore, in the conventional screw terminal structure, as shown in FIG. 8, in order to prevent the loosened screw terminal 59 from falling off from the terminal block 61, the screw portion of the screw terminal 59 screwed to the terminal block 61 is used. Is performed to expand and deform the tip of the substrate by spinning or caulking. However, it is very difficult to expand and deform the screw portion of the screw terminal 59 in a state where only a narrow space can be secured, and it is inevitable that the cost is increased.
[0008]
When the screw terminal 59 whose screw portion is expanded and deformed is loosened, not only the expanded deformed portion is screwed and damaged with the screw hole of the terminal block 61 but also the expanded deformed portion of the screw portion is screwed with the screw hole. In spite of being screwed firmly, the screw terminal 59 itself may be damaged as a result of applying an excessive external force to loosen the screw terminal 59.
[0009]
The present invention has been made in view of such an inconvenience, and a screw terminal structure capable of effectively preventing a screw terminal from falling off and not causing damage to the screw terminal and the terminal block. The purpose is to provide.
[0010]
[Means for Solving the Problems]
The screw terminal structure according to the first aspect of the present invention includes a screw terminal, a terminal block to which the screw terminal is screwed with a terminal plate interposed therebetween, and a terminal block cover arranged to surround the terminal block. Wherein the terminal block cover has a partition wall that covers the outside of the screw terminal in the reciprocating direction, and the partition wall allows the screw terminal to pass therethrough, while the terminal plate covers the screw terminal. A through hole that prevents insertion is formed, and the distance from the inner surface of the partition to the outer surface of the terminal block is set to be substantially the same as the length from the tip of the screw portion of the screw terminal to the outer surface of the terminal plate. It is characterized by having been done.
[0011]
The screw terminal structure according to a second aspect of the present invention is the screw terminal structure according to the first aspect, wherein a head of the screw terminal has a height sufficiently larger than a thickness of the partition wall. And
[0012]
A screw terminal structure according to a third aspect of the present invention is the screw terminal structure according to the first or second aspect, wherein each of a tip of a screw portion of the screw terminal and a screw hole formed in the terminal block is provided. And a chamfered portion that abuts each other is formed.
[0013]
A screw terminal structure according to a fourth aspect of the present invention is the screw terminal structure according to any one of the first to third aspects, wherein a protrusion having a diameter smaller than that of the screw hole is provided at a tip of a screw portion of the screw terminal. Is formed.
[0014]
BEST MODE FOR CARRYING OUT THE INVENTION
FIG. 1 is an exploded perspective view showing the entire structure of a detector according to the present embodiment, FIG. 2 is a perspective view showing a main part of a screw terminal structure of a base body, and FIG. 3 is only a screw terminal structure of the detector. It is sectional drawing which expands and shows. 4 is an enlarged view of a main part of a detector, showing a screw terminal structure, FIG. 5 is an enlarged view of a main part of a screw terminal structure according to a modification, and FIG. FIG. 3 is a perspective view showing the entire structure of a cover main body.
[0015]
The detector 1 according to the present embodiment is, for example, a fire alarm, and as shown in FIG. 1, a base body 2 fixed by being attached to a mounting surface such as a ceiling surface or a wall surface of a building; And a cover main body 3 detachably connected to the base main body 2. The base body 2 here is a substantially circular bottomed cylindrical container made of an insulating synthetic resin or the like, and a peripheral wall 4 having a predetermined thickness is erected at a predetermined height along the outer peripheral edge of the bottom surface. I have.
[0016]
The base body 2 is fixed in a state where the back surface of the bottom portion is in contact with the mounting surface by a mounting screw inserted through the opening 5 in the bottom portion, and an alarm buzzer or the like is provided on the surface of the bottom portion. A wiring space 7 for accommodating an electric wire 6 such as a signal line for communication with a certain external device is provided. An opening 8 for drawing in the electric wire is formed at a predetermined position along the circumferential direction of the base body 2, and the inner end of the electric wire 6 drawn into the wiring space 7 from the outside through the opening 8 is connected to the base. It is fixed to a circuit board 10 (see FIG. 2B) using screw terminals 9 arranged on the bottom surface of the main body 2.
[0017]
Further, cover locking pieces 11 are formed at predetermined positions along the circumferential direction of the peripheral wall 4 erected on the bottom surface of the base body 2, that is, at positions symmetrical to each other. The locking piece 11 protrudes inward from the bottom surface. In the present embodiment, the openings 5 and 8 and the cover locking pieces 11 are provided at corresponding positions. However, there is no necessity, and they may be provided at different positions.
[0018]
The screw terminal structure of the detector 1 is, as shown in FIG. 2 (A) in an assembled state and in FIG. 2 (B) in an exploded state, a screw terminal 9 and a screw portion of the screw terminal 9. The terminal block 12 includes a fitted terminal plate 12, a terminal block 13 to which the screw terminals 9 are screwed while sandwiching the terminal plate 12, and a terminal block cover 14 arranged so as to surround the terminal block 13. At this time, the terminal block 13 made of insulating synthetic resin and having a screw hole (female screw) for screwing the screw portion (male screw) of the screw terminal 9 is fixed to the circuit board 10, while the terminal block is fixed. The cover 14 is fitted over the circuit board 10 so as to surround the screw terminals 9 and the terminal plate 12 screwed to the terminal block 13.
[0019]
In other words, in this screw terminal structure, the inner end of the electric wire 6 is arranged between the terminal plate 12 and the terminal block 13 and the screw terminal 9 is tightened to restrain the electric wire 6 while the screw terminal 9 is loosened. Accordingly, the inner end of the electric wire 6 is detached from between the terminal plate 12 and the terminal block 13. The circuit board 10 is also provided with a pair of connection terminals 15 having a so-called crocodile structure, and each connection terminal 15 is individually electrically connected to each of the screw terminals 9.
[0020]
Further, at this time, the terminal block cover 14 moves the screw terminal 9 forward and backward as shown in FIG. 3 (A) showing a state where the screw terminal is tightened, and FIGS. 3 (B) and 4 showing a state where the screw terminal is loosened. The partition 16 has a through hole 17 that allows the head of the screw terminal 9 to be inserted while the terminal plate 12 cannot be inserted. . At this time, the distance from the inner surface of the partition 16 to the outer surface of the terminal block 13 is set substantially equal to the length from the tip of the screw portion of the screw terminal 9 to the outer surface of the terminal plate 12.
[0021]
In the case where the screw terminal structure according to the present embodiment is employed, as shown in FIG. 4, even if the screw terminal 9 is loosened in order to separate the inner end of the electric wire 6 from between the terminal plate 12 and the terminal block 13. Since the terminal plate 12 externally fitted to the screw portion of the loosened screw terminal 9 cannot be inserted through the through hole 17 formed in the partition 16 of the terminal block cover 14, the screw terminal 9 falls off the terminal block 13. You will not do it. Further, since the distance from the inner surface of the partition 16 to the outer surface of the terminal block 13 and the length from the tip of the screw portion of the screw terminal 9 to the outer surface of the terminal plate 12 are substantially the same, the screw terminal 9 is loosened. When the terminal plate 12 comes into contact with the partition 16 of the terminal block cover 14, the screw portion of the screw terminal 9 is surely withdrawn from the screw hole of the terminal block 13, and Hole damage cannot occur.
[0022]
Incidentally, the present invention is not limited to the screw terminal structure described above, and it is also possible to adopt a screw terminal structure as shown in FIG. 5, that is, various screw terminal structures according to modifications. First, as shown in FIG. 5A, the head of the screw terminal 9 preferably has a height sufficiently larger than the thickness of the partition 16 of the terminal cover 14. With such a structure, even if the distance from the inner surface of the partition 16 to the outer surface of the terminal block 13 is slightly larger than the length from the tip of the screw portion of the screw terminal 9 to the outer surface of the terminal plate 12, the loosening continues. As a result, the screw portion of the screw terminal 9 is securely withdrawn from the screw hole of the terminal block 13.
[0023]
Further, as shown in FIG. 5 (B), a chamfered portion which abuts on each of the tip of the screw portion of the screw terminal 9 and the screw hole formed in the terminal block 13 may be formed. Good. Further, as shown in FIG. 5C, a protrusion 19 having a smaller diameter than the screw hole may be formed at the tip of the screw portion of the screw terminal 9. With these structures, the screw portion of the screw terminal 9 is easily introduced into the screw hole of the terminal block 13. That is, when the screw terminal structure according to the modified example is adopted, the dimensional accuracy of each component may be somewhat coarse, and the manufacturing cost of the component can be reduced.
[0024]
On the other hand, the cover main body 3 provided in the detector 1 is a substantially circular hollow container made of an insulating synthetic resin or the like, and has a slightly larger diameter than the base main body 2. Various electronic circuit components and the like serving as detection means are built in the cover body 3. As shown in FIG. 6, a replaceable power supply for power supply is provided on the back surface of the cover body 3 facing the base body 2. A battery 21 is detachably stored.
[0025]
The cover main body 3 is provided with a pair of connection contacts 22 that are individually conductive as being sandwiched by the connection terminals 15 of the base main body 2, and these connection contacts 22 are detection means. Conducted with various electronic circuit components. At a predetermined position along the circumferential direction of the cover body 3, a pair of base locking pieces 23 that engage with the cover locking pieces 11 formed on the peripheral wall 4 of the base body 2 are formed.
[0026]
Therefore, when the cover main body 3 facing the base main body 2 is rotated, the cover locking pieces 23 of the cover main body 3 and the cover locking pieces 11 of the base main body 2 engage with each other. It is connected to the base body 2. At this time, each of the connection contacts 22 is held between the respective connection terminals 15 to conduct, and the open surface of the cover body 3 containing the battery 21 is closed by the base body 2. In the figure, reference numeral 24 denotes a drawstring, and 25 denotes an alarm sound stop button. The alarm sound stop button 25 is used at the time of operation confirmation and at the time of alarm stop.
[0027]
Note that the detector 1 according to the present embodiment is not limited to a fire alarm, and may detect a person or the like. Further, the scope of application of the screw terminal structure described in the present embodiment is not limited to only the detector 1 and, of course, can be applied to other devices and devices.
【The invention's effect】
In the screw terminal structure according to the first aspect of the present invention, since the terminal plate externally fitted to the screw portion of the screw terminal cannot be inserted through the through hole formed in the partition of the terminal block cover, the screw is loosened. The effect that the terminal does not drop off from the terminal block is obtained. Also, since the distance from the inner surface of the bulkhead to the outer surface of the terminal block is almost the same as the length from the tip of the screw part of the screw terminal to the outer surface of the terminal plate, the terminal plate becomes loose as a result of loosening the screw terminal. At the time of the contact, the screw portion of the screw terminal is surely withdrawn from the terminal block, and the advantage that the screw terminal and the terminal block are not damaged is also ensured.
[0029]
With the screw terminal structure according to any one of claims 2 to 4, it is possible to effectively prevent the screw terminal from falling off, and furthermore, it does not cause damage to the screw terminal and the terminal block. Alternatively, there is no problem even if the dimensional accuracy of each component having the screw terminal structure is somewhat coarse, and the effect of reducing the manufacturing cost of these components can be obtained.
[Brief description of the drawings]
FIG. 1 is an exploded perspective view showing the entire structure of a detector according to the present embodiment.
FIG. 2 is a perspective view of an essential part showing a screw terminal structure of a base body provided in the detector according to the present embodiment.
FIG. 3 is an enlarged sectional view showing a screw terminal structure of the detector according to the present embodiment.
FIG. 4 is an explanatory view showing a main part of the screw terminal structure of the detector according to the present embodiment in an enlarged manner.
FIG. 5 is an explanatory view showing a main part of a screw terminal structure according to a modification in an enlarged manner.
FIG. 6 is a perspective view showing the entire structure of a cover main body provided in the detector according to the present embodiment.
FIG. 7 is a perspective view showing the entire structure of a detector according to a conventional embodiment.
FIG. 8 is an enlarged view showing a main part of a screw terminal structure of a detector according to a conventional mode.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Detector 9 Screw terminal 12 Terminal board 13 Terminal block 14 Terminal block cover 16 Partition wall 17 Through hole 19 Projection

Claims

ネジ端子と、該ネジ端子が端子板を挟んで螺合される端子台と、該端子台を取り囲んで配置される端子台カバーとを備えてなるネジ端子構造であって、
前記端子台カバーは前記ネジ端子の進退方向の外方を覆う隔壁を有しており、かつ、該隔壁には前記ネジ端子の挿通を許容する一方で前記端子板の挿通を不可とする貫通孔が形成されているとともに、前記隔壁の内面から前記端子台の外面までの間隔は前記ネジ端子のネジ部の先端から前記端子板の外面までの長さと略同一に設定されていることを特徴とするネジ端子構造。A screw terminal structure comprising a screw terminal, a terminal block to which the screw terminal is screwed with a terminal plate interposed therebetween, and a terminal block cover arranged to surround the terminal block,
The terminal block cover has a partition wall that covers the outside of the screw terminal in the advancing and retreating direction, and the partition wall has a through hole that allows the insertion of the screw terminal but disables the insertion of the terminal plate. Is formed, and the interval from the inner surface of the partition to the outer surface of the terminal block is set substantially equal to the length from the tip of the screw portion of the screw terminal to the outer surface of the terminal plate. Screw terminal structure.

前記ネジ端子の頭部は、前記隔壁の厚みよりも十分に大きい高さを有していることを特徴とする請求項１に記載のネジ端子構造。The screw terminal structure according to claim 1, wherein a head of the screw terminal has a height sufficiently larger than a thickness of the partition wall.

前記ネジ端子のネジ部の先端と前記端子台に形成されたネジ孔との各々には、互いに当接しあう面取り部が形成されていることを特徴とする請求項１または請求項２に記載のネジ端子構造。The chamfered part which contacts each other is formed in each of the front-end | tip of the screw part of the said screw terminal, and the screw hole formed in the said terminal block, The Claim 1 or Claim 2 characterized by the above-mentioned. Screw terminal structure.

前記ネジ端子のネジ部の先端には、前記ネジ孔よりも小径の突起部が形成されていることを特徴とする請求項１〜請求項３のいずれかに記載のネジ端子構造。4. The screw terminal structure according to claim 1, wherein a protrusion having a diameter smaller than that of the screw hole is formed at a tip of the screw portion of the screw terminal. 5.