【０００１】
【発明の属する利用分野】この発明は、外囲器内に収容した感温部材とスイッチ機能部品の共働により所定温度で電気回路を遮断または導通状態に切換える感温型温度ヒュ−ズ、特に感温部材の非導電性ペレットの温度に対する変形変位量を利用する感温変位材を用いた温度ヒュ−ズに関する。
【０００２】
【従来の技術】温度ヒューズは、機器の異常過熱を正確に検知し、速やかに回路を遮断または導通させる保護部品として、各種家電製品、携帯機器、通信機器、事務機器、車載機器、ＡＣアダプタ、充電器、モータ、電池、その他電子部品に使用されている。従来の温度ヒューズは可溶体である感温材料により大きく２つに分類され、導電性の低融点合金を使用する可溶合金型温度ヒュ−ズと非導電性の感温物質を使用する感温ペレット型温度ヒュ−ズとがあって、いずれも周囲温度の異常上昇時に作動して機器の電流遮断あるいは通電路の導通状態を形成して機器類を保護する、いわゆる非復帰型温度スイッチである。作動する温度は使用する感温材で決められ、通常、６０℃から２５０℃、定格電流が０．５Ａから１５Ａの範囲で機能する保護部品として品揃えされ、初期の常温状態における導通または遮断状態を所定の動作温度で逆転させて遮断または導通状態にする電気的保護手段である。
【０００３】非導電性の感温ペレットを用いる感温型温度ヒュ−ズは、通常、筒型外囲器の両端にリ−ドを取付け、外囲器内に所定の溶融温度を有する化学薬品を所定形状に成形加工した感温ペレットを収容し、これに圧縮ばねなどで可動導電体に押圧を作用させて構成されている。たとえば、外囲器がガラス管でその管内の一部分に一対の導電膜を形成し、この管内に感温部材、通電位置と遮断位置間を移動可能な可動導電体、およびこの可動導電体に絶縁体を介在して押圧する圧縮ばねを順次挿入した構造の温度ヒュ−ズがある（特開平１０−１７７８３３号公報参照）。また、筒型金属ケ−スを用い、一方の開口側のリ−ドをかしめ固定し、他方の開口側のリ−ドを絶縁ブッシングを介在して固定し、この金属ケ−ス内に感温部材を２枚の板ばね間に挾み込み、常温時は板ばねをケ−ス内壁面に接触させる簡素化構造の温度ヒュ−ズがある（特開平５−３０７９２５号公報参照）。さらに、一方に導出リ−ドと電気的に接続した金属ケ−ス内に弾性体、感温部材、金属片、ばね可動片および封止セラミックを順次挿入し、セラミックに他方のリ−ドを貫通配置した温度ヒュ−ズも知られている（特開平９−２８２９９２号公報参照）。特に、スプリング部材として強圧縮ばねと弱圧縮ばねとを使用して可動接点体に押圧力を作用させて動作温度時の移動を確実にする公知の温度ヒュ−ズも知られている（特開平５−１３５６４９号、特開平１１−１１１１３５号公報参照）。
【０００４】
【発明が解決しようとする課題】上述の感温ペレット型温度ヒュ−ズは、感温材に比較的純粋な化学薬品が使用されており、この物質を造粒し所定の形状に成形加工して感温ペレットとするのであるが、ペレット化後の軟化、変形、昇華、潮解性など環境条件の影響を受けやすく、製造上の各工程管理や製品後の保管条件などの観点で多くの問題点があった。たとえば、ペレット成形加工では材質自体に潮解性があるものでは外気に触れることで変形したり昇華したりするので外気遮断のための完全なシ−ル管理が要求される。また、成形加工品で硬度などの機械的強度が弱く温度ヒュ−ズの組立において、スプリング圧により変形して不具合となることがある。さらには、製品後の温度ヒュ−ズに対して、高温高湿の保管条件ではペレットの昇華、潮解など製品寿命に影響を受けることがあり、電気的特性の低下にもなる。特に、化学薬品を使用する従来の感温部材では高温下での軟化変形が顕著で徐々に縮小化して接点が解離する不具合を招く。それゆえ、使用環境や経時的変化の影響を受け難くて、周囲の厳しい保管雰囲気に曝され高温高湿や有害ガスを浴びる環境下においても感温部材自体に欠陥を生じさせない感温型温度ヒュ−ズの提案が望まれていた。
【０００５】したがって、本発明の目的は、上記欠点を解消するために提案されたものであり、感温部材の物理化学的特性に着目して感温材料を選定使用する新規かつ改良された感温変位材を用いた温度ヒュ−ズを提供することにある。すなわち、感温ペレットとしての非導電性で熱変形性のゴムブロック体を用いその温度対変位の特性変化に着眼して、ブロック体の特定変位量でスイッチ作動させる温度ヒューズの提供を目的とする。
【０００６】
【課題を解決するための手段】本発明においては、感温部材は、熱変形性物質についてその物質の温度に対する変形変位量の特性曲線に着目して選定され、所定の動作温度での変位を利用してスイッチ機能手段を作動する感温変位材を用いた温度ヒューズが開示される。材料の選定にあたっては物理化学的性質が配慮され、成形加工、製造工程での取り扱いの容易さ、成形後の変質や変形等に対処できる材料が考慮され、その結果、物理化学的特性が安定な動作特性を有する感温変位材を用いた温度ヒュ−ズが提供される。具体的には、所定の温度で特定量で変位する絶縁性で熱変形性を有する感温部材が選択使用され、この感温部材を収容する筒型外囲器と、外囲器の一端側に取付けた第１電極を形成する第１リ−ド部材と、外囲器の他端側に取付けた第２電極を形成する第２リ−ド部材と、外囲器に収容された可動導電部材およびこの可動導電部材に押圧力を作用するスプリング部材を含む感温部材と共働きするスイッチ機能手段とを具備し、感温部材の変位状態を検知して第１および第２電極の間を遮断または導通状態の何れかに切換える感温変位材を用いた温度ヒュ−ズを開示する。特に、感温部材は熱変形性ゴムを主材料としこれに所望する物理化学的特性を付与する添加物、たとえば、無機物質のフィラなどにより電気的特性としての絶縁抵抗値や耐電圧値を高めるもの、機械的特性としての成形加工や強度性の改善材、さらに化学的特性としての酸化防止や老化防止に役立つ改良剤等を混合した感温部材を使用する。したがって、従来の化学薬品による感温ペレットで発生する変質が抑止され、機械的強度の改善される感温変位材を用いた温度ヒュ−ズが得られる。
【０００７】
【発明の実施の形態】本発明の感温変位材を用いた温度ヒュ−ズは、熱変形する感温部材と、この感温部材を収容する筒状金属ケ−スと、この金属ケ−スの一端開口側にかしめ固定して取付けてケ−ス内壁面を第１電極とする第１リ−ド部材および他端開口側に装着の絶縁ブッシングを貫通してその先端部を第２電極とする第２リ−ド部材と、この金属ケ−スに収容される可動接点体およびこの可動接点体に押圧力を付与する圧縮ばね部材を含むスイッチ機能部品とを具備し、感温部材が所定の動作温度で所定の値だけ変形・変位したときに第１および第２電極間を遮断状態から導通状態へ、又は逆の状態に切換える。好ましくは、圧縮ばね部材が強圧縮ばねと弱圧縮ばねとからなり、強圧縮ばねが弱圧縮ばねの弾性力に抗して可動接点体を第２電極に押圧接触させる。また、強圧縮ばねはその両端に押圧板を介して感温部材および可動接点体の間に配置し、組立の容易化と共にばね動作の安定化が図られ、感温部材の変形変位時に弱圧縮ばねの押圧力により可動接点体を移動させて回路遮断する常時ＯＮ−異常時ＯＦＦの温度ヒュ−ズとする。一方、単一ばねを感温部材に当接して常時ＯＦＦに設定して感温部材の熱変位を拡大する方向にして配置すると、感温部材は過熱により単一ばねの押圧力に抗して可動接点体を移動させ回路導通する常時ＯＦＦ−異常時ＯＮとなる逆動作型作動の感温変位材を用いた温度ヒュ−ズが提供できる。
【０００８】別の実施形態を説明すると、本発明は、温度で変形する感温部材が所定の温度に上昇したとき、その変位量の変化でＯＮ−ＯＦＦのスイッチ切換えすると共に所定温度以下に下降したときに変位量が変わって元の状態に戻り、ＯＦＦ−ＯＮのスイッチ切換えをする復帰型温度ヒューズとして使用することもできる。例えば、感温部材と、これを収容する筒状金属ケ−スと、この金属ケ−スの一端開口側にかしめ固定して取付けてケ−ス内壁面を第１電極とする第１リ−ド部材と、この金属ケ−スの他端開口側に装着した絶縁ブッシングと、この絶縁ブッシングを貫通させてその先端部を第２電極とする第２リ−ド部材と、第１電極と第２電極間に配置された長手方向に延びる２枚の舌片状平板からなる導電性Ｖ字形弾性舌片を具備し、このＶ字形舌片に感温部材を挾み込んで舌片裏面をケ−ス内壁面に接触させた温度ヒュ−ズができる。この場合に２枚の舌片状平板間に挟まれた感温部材が温度変化で縦横の伸縮が異なるとその取付方向によりスイッチ動作をＯＮ−ＯＦＦまたはＯＦＦ−ＯＮで選択できる。
【０００９】
【実施例１】図１および図２は本発明に係る実施例の感温変位材を用いた温度ヒュ−ズでそれぞれ常温の平常時と過熱異常動作時の温度ヒュ−ズの部分断面図を示す。この感温変位材を用いた温度ヒュ−ズは、銅、黄銅などの良導体で熱伝導性良好な円筒状金属ケ−ス１と、その一方の開口側にかしめ固定した第１リード部材２と、この金属ケ−ス１内に収容された感温部材３、一対の押圧板４、良導電性で適度の弾性を有する銀合金の可動接点体５および弱圧縮ばね６を含むスイッチ機能部品と、金属ケ−ス１の他方の開口に挿入された絶縁ブッシング７と、この絶縁ブッシング７を貫通して金属ケ−ス１から絶縁配置された第２リ−ド部材８とを具備して構成される。なお、９は図２の感温変位材過熱動作後の状態で可動接点体５と接触する接点部位である。感温部材３は熱変形性樹脂を主材料として成形加工したゴムブロック体であり、温度ヒュ−ズの動作温度で所定の変位量を検知してスイッチング動作する。換言すると、熱変形性樹脂のゴムは所定の動作温度に対応して所定量の変位を伴う材料であり、図３に示すような温度対変位の特性曲線２０を有する。具体的には、特性曲線２０のうち動作温度が７０℃ないし９０℃の略直線的部分２１が選択して利用される。例えば、図３の特性曲線２０を有するゴムを使用して７０℃で導通させる場合、変位量δｈが約１４０μｍを越えた時点で接点が接触するように間隔を調整して設定する。また、９０℃で導通させるにはδｈを５２５μｍで離間して設定して逆動作型温度ヒューズになる。一方、正常動作型温度ヒューズとするにはゴムブロック体の配置を温度上昇で収縮する方向で利用する。本発明の特徴は熱変形性樹脂の感温部材を用いる温度ヒュ−ズであるが、使用する熱変形ゴムの物理化学的諸特性に応じて所望する特性の改善策を講じられ、たとえば、酸化や老化しやすい化学的特性の場合には酸化防止剤や老化防止剤を添加するほか、感温部材へフィラを充填して電気抵抗値や絶縁性改善に役立てる。本発明の熱変位特性を有する感温部材の特色は、従来の化学薬品部材に比べて強度が高く部材加工が容易になること、加えて、化学薬品部材でしばしば問題となる高温高湿下での軟化変形や水分による潮解、あるいは昇華がほとんど発生しないことである。したがって、感温部材の経時的変化に伴うスイッチ作動上での不具合を解消できる。
【００１０】
【実施例２】本発明に係る別の実施例として、熱変形性樹脂の感温部材であるゴムブロック体を使用した簡素化構造の温度ヒュ−ズについて説明する。この温度ヒュ−ズは、特開平５−３０７９２５号公報に開示された温度ヒューズの改良であり、前述する実施例と同様に、所定の動作温度で変位する熱変形性ゴムブロック体と、このブロック体を収容する筒状金属ケ−スと、この金属ケ−スの一端開口側にかしめ固定して取付けられてケ−ス内壁面を第１電極とする第１リ−ド部材と、この金属ケ−スの他端開口側に挿入して装着固定した絶縁ブッシングと、この絶縁ブッシングを貫通し先端部を第２電極とする第２リ−ド部材とを具備し、さらに可動導電体部材およびスプリング部材の両機能を奏するように感温部材のブロック体を挾み込む２枚のばね平板のＶ字形弾性舌片を具備する。このＶ字形弾性舌片は金属ケ−スの内壁面の第１電極と第２リ−ド部材の先端部の第２電極との間に配置する。導電性のＶ字形弾性舌片は長手方向に延びた２枚の平板ばねはであり、その一端を固定して第２リ−ド部材の第２電極と電気機械的に結合し、他端を開脚自在であるＶ字形弾性舌片の裏面を金属ケ−ス内壁面の第１電極に接触させる。また、感温部材のブロック体はＶ字形弾性舌片の板ばね間に開脚側から挾み込むことで押圧を作用させて感温部材を保持する。したがって、常温の平常時は平板ばねを介して導電状態が維持されるが、周囲温度が特定の温度以上に上昇すると感温部材のブロック体が変位し平板ばねが圧縮力で縮まってケ−ス内壁面との接触が断たれ、第１および第２リ−ド部材間の電気回路を遮断することになる。逆に、ブロック体が温度上昇で膨張する方向を挟み込めば遮断から導通状態に切換えることになる。この実施例は温度ヒュ−ズを構成する部品点数を減らして構造を簡素化して、感温部材の熱変形性樹脂による強度性を効果的に発揮する。
【００１１】
【実施例３】本発明のさらに別の実施例として、特開平１０−１７７８３３号公報の温度ヒューズを改良して感温変位材を用いた温度ヒュ−ズが得られる。例えば、筒状絶縁管に感温部材を収容して、第１および第２リ−ド部材をこの絶縁管の開口側にそれぞれ固定すると共に第１および第２電極をそれぞれケ−ス内壁面の一部分に形成し、これら第１電極と第２電極の通電位置から遮断位置に移動可能な球状の導電体を絶縁管に収容し、この球状導電体を球状絶縁体を介在して感温部材側に押圧するスプリングを具備して構成する。スプリングは絶縁管の一端側に配置されており、球状絶縁体を介して球状導電体を感温部材に押圧する。平常時に導電体は内壁面の第１および第２電極と接触状態にあって回路の導通状態を維持する位置にある。そして、感温部材が温度上昇で所定の温度を越えると変位量が所定値に達し、それによって導電体がスプリングの押圧で非導通位置に移動し回路遮断となる。
【００１２】
【発明の効果】この発明によれば、感温材料が温度に対して変位量がほぼ直線的な関係を有する熱変形性絶縁樹脂から選択され、必要に応じて添加物を使用し、物理化学的特性を考慮することで成形加工が容易で成形した感温部材の変質を抑止して長寿命化と動作安定化の実現が期待できる。特に、組立加工の容易さと部材強度の改善は感温変位材を用いた温度ヒュ−ズの構成部品の簡素化に役立ち、ロ−コスト製品の提供を可能にする。また、温度ヒュ−ズの保管並びに経時変化において、高湿度や有害ガスの雰囲気中に置かれても長期にわたり安定化が図られ、腐食や絶縁度の劣化を防ぎ保管中はもとより使用中でも電気的特性を含めた性能低下を防止し、経年変化も抑止され常に所定の動作温度で正確に作動する安定性と信頼性の向上に役立つなどの実用的効果が大きい。
【図面の簡単な説明】
【図１】本発明の実施例で常温時の感温変位材を用いた温度ヒューズの縦断面図。
【図２】本発明の実施例で過熱動作後の感温変位材を用いた温度ヒューズの縦断面図。
【図３】本発明で使用する感温変位材の温度対変位の特性を示す特性曲線図。
【符号の説明】
１ 金属ケ−ス（外囲器）
２ 第１リード部材
３ 感温部材（ゴム）
５ 押圧板
６ 可動接点体（可動導電部材）
７ 絶縁ブッシング
８ 第２リ−ド部材
９ 可動接点体５と接触する接点部位
２０ 特性曲線
２１ 直線的部分[0001]
BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a temperature-sensitive type temperature fuse for switching an electric circuit to a cut-off state or a conduction state at a predetermined temperature by the cooperation of a temperature-sensitive member housed in an envelope and a switch function component. The present invention relates to a temperature fuse using a temperature-sensitive displacement material utilizing a deformation displacement amount of a non-conductive pellet of a temperature-sensitive member with respect to a temperature.
[0002]
2. Description of the Related Art Thermal fuses are used as protective components for accurately detecting abnormal overheating of a device and promptly shutting off or conducting a circuit, and include various home appliances, portable devices, communication devices, office devices, vehicle devices, AC adapters, and the like. Used in chargers, motors, batteries, and other electronic components. Conventional thermal fuses are broadly classified into two types depending on the temperature-sensitive material that is a fusible material. A fusible alloy type temperature fuse that uses a conductive low-melting alloy and a temperature-sensitive type that uses a nonconductive temperature-sensitive material. There is a pellet-type temperature fuse, which is a so-called non-return type temperature switch which operates when an ambient temperature rises abnormally and protects the equipment by cutting off the current of the equipment or forming a conductive state of the current path. . The operating temperature is determined by the temperature-sensitive material used, and it is normally available as a protective component that functions at a temperature of 60 ° C to 250 ° C and a rated current in the range of 0.5A to 15A. Is an electrical protection means that is turned off at a predetermined operating temperature to turn off or on.
A temperature-sensitive temperature fuse using non-conductive temperature-sensitive pellets is generally a type in which leads are attached to both ends of a cylindrical envelope and a chemical having a predetermined melting temperature is contained in the envelope. Is stored in a predetermined shape, and the movable pellet is pressed by a compression spring or the like. For example, the envelope is a glass tube, a pair of conductive films is formed in a part of the tube, a temperature-sensitive member, a movable conductor movable between an energized position and a cut-off position, and an insulator insulated by the movable conductor. There is a temperature fuse having a structure in which compression springs for pressing with a body interposed are sequentially inserted (see Japanese Patent Application Laid-Open No. H10-177833). Also, using a cylindrical metal case, the lead on one opening side is fixed by caulking, and the lead on the other opening side is fixed with an insulating bushing therebetween. There is a temperature fuse having a simplified structure in which a warm member is sandwiched between two leaf springs and the leaf spring contacts the inner wall surface of the case at normal temperature (see Japanese Patent Application Laid-Open No. 5-307925). Further, an elastic body, a temperature-sensitive member, a metal piece, a spring movable piece and a sealing ceramic are sequentially inserted into a metal case electrically connected to the lead-out lead on one side, and the other lead is inserted into the ceramic. A temperature fuse having a through-hole is also known (see Japanese Patent Application Laid-Open No. 9-282929). In particular, there is known a known temperature fuse which uses a strong compression spring and a weak compression spring as a spring member to apply a pressing force to a movable contact body to ensure movement at an operating temperature (Japanese Patent Application Laid-Open No. HEI 9-208572). No. 5-135649 and JP-A-11-111135).
[0004]
In the above-mentioned temperature-sensitive pellet type temperature fuse, a relatively pure chemical is used as a temperature-sensitive material, and this material is granulated and formed into a predetermined shape. Temperature-sensitive pellets, but are susceptible to environmental conditions such as softening, deformation, sublimation, and deliquescence after pelletization, and there are many problems in terms of each process control in manufacturing and storage conditions after products. There was a point. For example, in the pellet forming process, if the material itself has a deliquescent property, it is deformed or sublimated by contact with the outside air, so that a complete seal management for shutting off the outside air is required. Also, the mechanical strength such as hardness of the molded product is weak, and in the assembly of the temperature fuse, it may be deformed due to the spring pressure, which may be a problem. In addition, the temperature fuse after the product may be affected by the life of the product such as sublimation and deliquescence of the pellet under storage conditions of high temperature and high humidity, resulting in a decrease in electrical characteristics. In particular, in the case of a conventional temperature-sensitive member using a chemical, the softening deformation at a high temperature is remarkable, and the temperature is gradually reduced to cause a problem that the contact is dissociated. Therefore, it is hardly affected by the use environment and the change with time, and does not cause a defect in the temperature-sensitive member itself even in an environment exposed to severe storage atmosphere and exposed to high temperature, high humidity and harmful gas. -Proposal was desired.
Accordingly, an object of the present invention is to solve the above-mentioned disadvantages, and a new and improved sensor which selects and uses a temperature-sensitive material by focusing on the physicochemical characteristics of the temperature-sensitive member. An object of the present invention is to provide a temperature fuse using a temperature displacement material. In other words, an object of the present invention is to provide a thermal fuse that uses a non-conductive and heat-deformable rubber block body as a temperature-sensitive pellet and focuses on the change in temperature-displacement characteristics and operates a switch at a specific displacement amount of the block body. .
[0006]
According to the present invention, a temperature-sensitive member is selected for a heat-deformable substance by paying attention to a characteristic curve of a deformation displacement amount with respect to a temperature of the substance, and a displacement at a predetermined operating temperature is determined. A temperature fuse using a temperature-sensitive displacement material that operates a switch function means using the same is disclosed. In selecting materials, physicochemical properties are taken into consideration, and materials that can handle deformation, deformation, etc. after molding, ease of handling in the manufacturing process and manufacturing process are considered, and as a result, physicochemical properties are stable. A temperature fuse using a temperature-sensitive displacement material having operating characteristics is provided. Specifically, an insulating and heat-deformable temperature-sensitive member that is displaced by a specific amount at a predetermined temperature is selected and used, and a cylindrical envelope accommodating the temperature-sensitive member, and one end of the envelope. A first lead member for forming a first electrode attached to the housing, a second lead member for forming a second electrode attached to the other end of the envelope, and a movable conductive member accommodated in the envelope. A switch function means cooperating with a temperature-sensitive member including a spring member for applying a pressing force to the movable conductive member, and detecting a displacement state of the temperature-sensitive member to shut off between the first and second electrodes. Also disclosed is a temperature fuse using a temperature-sensitive displacement material that switches to either a conductive state. In particular, the temperature-sensitive member is made of a heat-deformable rubber as a main material, and an additive for imparting desired physicochemical properties to the material, for example, an inorganic filler or the like, increases the insulation resistance value and withstand voltage value as electrical characteristics. A temperature-sensitive member mixed with a material, a material for improving molding and mechanical strength as mechanical properties, and a modifier for preventing oxidation and aging as chemical properties is used. Therefore, deterioration of the temperature-sensitive pellet caused by conventional chemicals is suppressed, and a temperature fuse using a temperature-sensitive displacement material with improved mechanical strength can be obtained.
[0007]
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A temperature fuse using a temperature-sensitive displacement material according to the present invention includes a temperature-sensitive member which is thermally deformed, a cylindrical metal case for housing the temperature-sensitive member, and a metal case. A first lead member having the inner wall surface of the case as the first electrode by caulking and fixing to one end opening side of the case, and an insulating bushing attached to the other end opening side, and the tip end thereof being the second electrode. And a switch function component including a movable contact member accommodated in the metal case and a compression spring member for applying a pressing force to the movable contact member. When deformed or displaced by a predetermined value at a predetermined operating temperature, the state between the first and second electrodes is switched from a cutoff state to a conduction state or vice versa. Preferably, the compression spring member includes a strong compression spring and a weak compression spring, and the strong compression spring presses the movable contact body against the second electrode against the elastic force of the weak compression spring. In addition, the strong compression spring is disposed between the temperature sensing member and the movable contact body at both ends via pressing plates, so that assembling is facilitated and the spring operation is stabilized, and the compression spring is weakly compressed when the temperature sensing member is deformed and displaced. The temperature fuse is always ON, and the temperature is OFF when there is an abnormality, in which the movable contact body is moved by the pressing force of the spring to interrupt the circuit. On the other hand, when the single spring is placed in the direction of expanding the thermal displacement of the temperature-sensitive member by setting the single spring in contact with the temperature-sensitive member to be always OFF, the temperature-sensitive member resists the pressing force of the single spring due to overheating. It is possible to provide a temperature fuse using a temperature-sensitive displacement material of a reverse operation type, which is always OFF, which moves a movable contact body and conducts a circuit, and which is ON when an abnormality occurs.
According to another embodiment, when the temperature-sensitive member which deforms with temperature rises to a predetermined temperature, the ON-OFF switch is switched according to a change in the displacement and the temperature falls below the predetermined temperature. When this is done, the amount of displacement changes and returns to the original state, and it can also be used as a return-type thermal fuse that switches off and on. For example, a temperature sensing member, a cylindrical metal case for housing the same, and a first electrode having the inner wall surface of the case as a first electrode by caulking and fixing to one end opening side of the metal case. A lead member, an insulating bushing mounted on the other end opening side of the metal case, a second lead member penetrating the insulating bushing and having a tip end as a second electrode, a first electrode and a first electrode. A conductive V-shaped elastic tongue consisting of two longitudinally extending tongue-shaped flat plates disposed between the two electrodes is provided. A temperature fuse in contact with the inner wall surface In this case, if the temperature-sensitive member sandwiched between the two tongue-shaped flat plates has different vertical and horizontal expansion and contraction due to a temperature change, the switch operation can be selected as ON-OFF or OFF-ON depending on the mounting direction.
[0009]
Embodiment 1 FIGS. 1 and 2 are partial cross-sectional views of a temperature fuse using a temperature-sensitive displacement material according to an embodiment of the present invention. Show. The temperature fuse using this temperature-sensitive displacement material is composed of a cylindrical metal case 1 having good heat conductivity with good conductors such as copper and brass, and a first lead member 2 fixed to one opening side of the case. A switch function component including a temperature-sensitive member 3 housed in the metal case 1, a pair of pressing plates 4, a movable contact body 5 of silver alloy having good conductivity and moderate elasticity, and a weak compression spring 6; And an insulating bushing 7 inserted into the other opening of the metal case 1 and a second lead member 8 penetrating through the insulating bushing 7 and insulated from the metal case 1. Is done. Reference numeral 9 denotes a contact portion that comes into contact with the movable contact member 5 after the temperature-sensitive displacement material overheating operation in FIG. The temperature sensing member 3 is a rubber block formed by molding a heat deformable resin as a main material, and performs a switching operation by detecting a predetermined displacement amount at the operating temperature of the temperature fuse. In other words, the rubber of the heat-deformable resin is a material that undergoes a predetermined amount of displacement corresponding to a predetermined operating temperature, and has a temperature-displacement characteristic curve 20 as shown in FIG. Specifically, a substantially linear portion 21 having an operating temperature of 70 ° C. to 90 ° C. in the characteristic curve 20 is selected and used. For example, when conducting at 70 ° C. using a rubber having the characteristic curve 20 of FIG. 3, the distance is adjusted and set so that the contacts come into contact when the displacement δh exceeds about 140 μm. Further, in order to conduct at 90 ° C., δh is set at a distance of 525 μm to form a reverse operation type thermal fuse. On the other hand, in order to obtain a normal operation type thermal fuse, the arrangement of the rubber block body is used in a direction of contracting as the temperature rises. A feature of the present invention is a temperature fuse using a temperature-sensitive member made of a heat-deformable resin. However, measures to improve desired characteristics are taken in accordance with the physicochemical characteristics of the heat-deformed rubber used. In the case of chemical characteristics that tend to age, antioxidants and antiaging agents are added, and fillers are filled into temperature-sensitive members to help improve electrical resistance and insulation. The feature of the temperature-sensitive member having the thermal displacement characteristic of the present invention is that the strength is higher than that of a conventional chemical member, and the member can be easily processed. Softening deformation, deliquescence due to moisture, or sublimation hardly occurs. Therefore, it is possible to solve the problem in the switch operation due to the temporal change of the temperature sensing member.
[0010]
[Embodiment 2] As another embodiment of the present invention, a temperature fuse having a simplified structure using a rubber block body which is a thermosensitive member made of a heat-deformable resin will be described. This temperature fuse is an improvement of the temperature fuse disclosed in Japanese Patent Application Laid-Open No. Hei 5-307925. Similar to the above-described embodiment, a heat-deformable rubber block which is displaced at a predetermined operating temperature and this block are used. A cylindrical metal case for accommodating the body, a first lead member fixedly attached to one end opening side of the metal case and having an inner wall surface of the case as a first electrode; An insulating bushing that is inserted into and fixed to the other end opening side of the case; and a second lead member that penetrates the insulating bushing and has a tip portion as a second electrode. It has two spring flat V-shaped elastic tongues sandwiching the block of the temperature sensing member so as to perform both functions of the spring member. The V-shaped elastic tongue is disposed between the first electrode on the inner wall surface of the metal case and the second electrode at the tip of the second lead member. The conductive V-shaped elastic tongue is two flat springs extending in the longitudinal direction, one end of which is fixed and electromechanically coupled to the second electrode of the second lead member, and the other end is fixed. The back surface of the V-shaped elastic tongue which can be freely opened is brought into contact with the first electrode on the inner wall surface of the metal case. Further, the block body of the temperature-sensitive member is held between the leaf springs of the V-shaped elastic tongue from the open leg side to exert a pressing force to hold the temperature-sensitive member. Accordingly, the conductive state is maintained through the flat spring at normal temperature, but when the ambient temperature rises to a specific temperature or higher, the block body of the temperature-sensitive member is displaced, and the flat spring is compressed by the compressive force to cause the case. The contact with the inner wall surface is cut off, thereby interrupting the electric circuit between the first and second lead members. Conversely, if the direction in which the block body expands due to a rise in temperature is interposed, the block is switched to the conductive state. In this embodiment, the number of parts constituting the temperature fuse is reduced, the structure is simplified, and the strength of the heat-sensitive member is effectively exhibited by the heat-deformable resin.
[0011]
Embodiment 3 As still another embodiment of the present invention, a temperature fuse using a temperature-sensitive displacement material can be obtained by improving the temperature fuse disclosed in Japanese Patent Application Laid-Open No. 10-177833. For example, a temperature sensing member is accommodated in a tubular insulating tube, and first and second lead members are fixed to the opening side of the insulating tube, respectively, and first and second electrodes are respectively formed on the inner wall surface of the case. A spherical conductor formed in a part and movable from a current-carrying position of the first electrode and the second electrode to a cut-off position is accommodated in an insulating tube, and the spherical conductor is connected to the temperature-sensitive member via the spherical insulator. And a spring that presses the spring. The spring is disposed on one end side of the insulating tube, and presses the spherical conductor to the temperature-sensitive member via the spherical insulator. Under normal conditions, the conductor is in contact with the first and second electrodes on the inner wall surface and is in a position to maintain the circuit conduction state. When the temperature of the temperature sensing member exceeds a predetermined temperature due to a rise in temperature, the amount of displacement reaches a predetermined value, whereby the conductor is moved to a non-conducting position by the pressing of the spring, and the circuit is interrupted.
[0012]
According to the present invention, the temperature-sensitive material is selected from heat-deformable insulating resins whose displacement has a substantially linear relationship with temperature. Considering the mechanical characteristics, it can be expected that the molding process is easy, the deterioration of the molded temperature-sensitive member is suppressed, and a longer life and a more stable operation are realized. In particular, the ease of assembling process and the improvement in the strength of the members contribute to simplifying the components of the temperature fuse using the temperature-sensitive displacement material, and provide a low-cost product. In addition, the temperature fuse is kept stable over a long period of time, even if it is stored in an atmosphere of high humidity or harmful gas. Practical effects such as prevention of deterioration in performance including characteristics, suppression of aging, and improvement of stability and reliability of always operating accurately at a predetermined operating temperature are great.
[Brief description of the drawings]
FIG. 1 is a longitudinal sectional view of a thermal fuse using a temperature-sensitive displacement material at normal temperature in an embodiment of the present invention.
FIG. 2 is a longitudinal sectional view of a thermal fuse using a temperature-sensitive displacement material after an overheating operation in an embodiment of the present invention.
FIG. 3 is a characteristic curve diagram showing temperature versus displacement characteristics of the temperature-sensitive displacement material used in the present invention.
[Explanation of symbols]
1 metal case (envelope)
2 First lead member 3 Temperature sensing member (rubber)
5 pressing plate 6 movable contact body (movable conductive member)
7 Insulating bushing 8 Second lead member 9 Contact portion 20 contacting movable contact body 5 Characteristic curve 21 Linear portion