JP2660545C

JP2660545C -

Info

Publication number: JP2660545C
Authority: JP
Original assignee: 日本テキサス・インスツルメンツ株式会社
Publication date: 1999-09-20

Description

【発明の詳細な説明】イ．産業上の利用分野本発明は、スイッチ装置に関し、特に、温度変化に対応して開閉動作を行うス
イッチ装置に関する。ロ．従来技術モータ等の電気機械は、異常状態になると発熱し、その侭使用を続けると、巻
線の絶縁被覆が焼けるなどして使用不能に至る。これを防止するため、バイメタ
ルを使用して異常電流と異常温度によって接点を開くようにしてOFF状態とする
スイッチ装置（保護装置）が使用されている。上記スイッチ装置には第７図〜第10図に示す構造のものがある。第７図はスイッチ装置21の内部平面図、第８図は第７図のVIII−VIII線矢視断
面図、第９図は第８図の拡大部分断面図である。冷間圧延鋼材製の収容部22内にはその底上に絶縁板30Ａを介して第一の導電板
25が設けられ、第一の導電板25上には絶縁板30Ｂを介して第二の導電板28が設け
られている。第一の導電板25の端部には可動接点支持板23が熔接によって固着さ
れ、可動接点支持板23の先端部には可動接点24が取付けられている。第一の導電
板25には固定具31によってバイメタル板27が固定される。可動接点支持板23はそ
の貫通孔23ｂが固定具31に対して非接触で嵌合し、可動接点24は第二の導電板28
上に設けられた固定接点29に接触している。この状態で、可動接点支持板23の２
個所の突部23ａ、23ａはバイメタル板27に対して第９図に示すｄ寸法だけ離れて
いて、可動接点支持板23の弾性によって可動接点24が固定接点29に圧接し、第一
、第二の導電板25、28は電気的に接続し、スイッチ装置21はON状態にある。第一
の導電板25の端子部25ａはリード線33に、第二の導電板28の端子部はリード線32
に夫々接続する。端子部25ａ、28ａは圧着端子であるが、圧着状態は図示省略し
てある。スイッチ装置21は図示しない電気機器（例えばモータ）内に取付けられ
、電気機器と電源との間に直列に接続される。電気機器が使用中に何等かのトラブルを起こして昇温し、これに伴ってスイッ
チ装置21が昇温すると、或いは大電流が流れて可動接点支持板23が加熱されると
、バイメタル板27も昇温し変形して可動接点支持板23の突部23ａ、23ａに接触し
、バイメタル板23の変形が更に進むと第10図に示すように、バイメタル板27が可
動接点支持板23を押し上げて可動接点24は固定接点29から離れ、第一、第二の導
電板25、28は電気的に遮断されてスイッチ装置21はOFF状態となり、電気機器を
保護する。ところが、第10図の状態になると、可動接点支持板23やバイメタル板27は放熱
して降温し、バイメタル板27は元の形状に復帰して可動接点支持板23の突部23ａ
、23ａから離れ、スイッチ装置は第９図の状態に戻って再びON状態となる。この
ようにスイッチ装置21がOFF状態になってから再びON状態になる迄の時間が短か
過ぎると、スイッチ装置21は、ON、OFFを短い周期で繰り返すことになって、不
都合である。そこで、バイメタル板27と可動接点支持板23の突部23ａ、23ａとの間隔ｄを、バイメタル板27の湾曲の程度に応じて、また上記OFF状態とする温度
（例えば70〜150℃の範囲内の所定の温度）に対応して所定の寸法とするように
、固定具31に設けられた図示しない微調整手段によってバイメタル板27の上下方
向の位置を調整するようにしている。例えば上記OFFとする温度が70℃ではｄを
１mmに、100℃ではｄを２mmとする。然しながら、この微調整は一品毎に手作業
で行わねばならなず、面倒であり、正確を期し難い。間隔ｄが大きすぎると、電
気機器が異常状態に長時間おかれてからスイッチ装置21がOFFとなり、電気機器
の保護が不確実になる。また、間隔ｄが小さ過ぎると、スイッチ装置21のON、OF
Fの繰り返し周期が小さくなり、例えば0.3秒間の周期でON、OFFが繰り返される
（チャタリングと呼ばれる。）ようになり、既にバイメタル板27や可動接点支持
板23が疲労を起こして正常な変形がなされなくなってON状態が持続され、或いは
スパークによる接点熔着が起こってON状態が持続され、電気機器を保護できなく
なってしまう。ハ．発明の目的本発明は、上記の事情に鑑みてなされたものであって、温度変化に対応して変
形する変位部材（例えばバイメタル）の精密な位置調整の必要がなく、チャタリ
ングを起こさず、また上記変形部材の疲労や接点熔着によってスイッチ機能を失
うことのない信頼性に優れたスイッチ装置を提供することを目的としている。ニ．発明の構成即ち、本発明は、収容部に対して固定されている固定接点と、前記収容部に対
して固定されている一端部と前記固定接点に当接する可動接点を備えた他端部と
を有し、前記可動接点が前記固定接点に対して隔離または接触することにより電
気回路の開閉がなされるように配置されている可動部材と、前記収容部に対して
前記可動部材の一端部と重なった状態で固定されている一端部と前記可動部材の
他端部とほぼ同一方向に延びる自由端部とを有し、通常温度においては前記可動
接点が前記固定接点に接触するように前記自由端部が前記可動部材から離れた第
１の位置にあり、温度が通常温度よりも高い所定温度に達するまでは昇温に伴っ
て徐々に変形が進行して前記自由端部が前記可動部材に接近し、温度が前記所定
温度に達すると急速な変形進行に転じて前記自由端部が前記一端部を支点として前記可動部材を押動しながら第２の位置まで急速に変位して前記可動接点を前記
固定接点から隔離させる変位部材と、前記収容部に対して前記可動部材の一端部
と前記変位部材の一端部とを重ね合わせた状態で固定する固定部材とを具備して
なることを特徴とするスイッチ装置に係わる。ホ．実施例以下、本発明の実施例を説明する。第１図及び第２図はスイッチ装置を示し、第１図はスイッチ装置１の内部平面
図、第２図は第１図のII−II線矢視断面図である。冷間圧延鋼板製の収容部２内にはその底上に絶縁板10Ａを介して導電板８が固
定具15、15によって固定されている。導電板８の一方の端部側には固定接点９が
設けられ、他方の端部は端子８ａとなっている。導電板８上には樹脂の台14が位
置し、台14上には下から順にバイメタル板７の端部近くと可動接点支持板（可動
接点を設けた可動部材）３の端部とが重合わされ、更にその上に黄銅板６が載置
され、これらは固定具11によって樹脂の台14に固定されている。この固定によっ
てバイメタル板７の一部、可動接点支持板３の端部側、黄銅板６は下からこの順
に密着している。黄銅板６及び固定具11の上面には絶縁層10Ｂが設けられ、収容
部２との間が絶縁される。バイメタル板７は下方へ向かって湾曲していて、その上記固定側とは逆の端部
は自由端になっている。可動接点支持板３の上記固定側とは逆の端部側には可動
接点４が設けられ、通常の状態では第２図に示すように可動接点支持板３の弾性
によって可動接点４が固定接点９に圧接し、可動接点支持板３と導電板８とは電
気的に接続していて、スイッチ装置１はON状態となっている。可動接点支持板３
の上記固定部より先（図に於いて右側）の端部には端子３ａが、導電板８の固定
接点９とは逆の（図に於いて右側の）端部には端子８ａが夫々形成され、端子３
ａはリード線12に、端子８ａはリード線13に夫々接続する。これらの接続は圧着
端子として接続されるのであるが、圧着状態は図示省略してある。第４図は、スイッチ装置１と電気機器（この図の例ではモータ）との接続の一
例を示す概略回路図である。電気機器が使用中に何等かのトラブルを起こして昇温し、これに伴ってスイッチ装置１が昇温すると、或いは大電流が流れて可動接点支持板３が加熱されると
、バイメタル板７が変形してその自由端が上方へ移動し、やがてバイメタル板７
の自由端が可動接点支持板３に設けられた耐摩耗接触板５に当接し、更にバイメ
タル板７の変形が進行すると、第３図に示すように可動接点支持板３は変形が進
行したバイメタル板７に押されて上方へ反るようになり、可動接点４は固定接点
９から離れ、スイッチ装置１はOFF状態となる。本例で注目すべきことは、スイッチ装置１がON状態からOFF状態に至る過程で
次のような現象が起こることである。バイメタル板７は、第２のON状態では下向
きに湾曲しており、第３図のOFF状態では第２図とは逆に上向きに反るように変
形している。第２図の状態からバイメタル板７が昇温して第３図の状態になろう
とする初期では、バイメタル板は、昇温に伴って徐々に変形が進行し、所定の形
状になると急速に変形が進行する。即ち、バイメタル板７は、その変形量が閾値
に達する迄は徐々に変形が進行し、変形量がこの閾値に達すると急速に変形が進
行する。この変形初期の徐々に変形が進行する過程は、クリープ（匍匐（ほふく
））と呼ばれている。バイメタル板７のクリープを過ぎてからの急速な変形進行
（スナップアクション）によって可動接点支持板３は急速に上方へ押し上げられ
、従って可動接点４は固定接点９から速やかに離れ、スパークによる接点熔着が
起こることがない。前記バイメタル板変形量の閾値はスイッチ装置１をON状態か
らOFF状態にする温度によって変わり、この温度が高い程上記閾値は大きい。従
って、第２図でバイメタル板７の自由端と可動接点支持板との距離は、スイッチ
装置１をON状態からOFF状態にする設定温度に対応して決定すれば良い。つまり
、与えられた設定温度に対してバイメタル板７が上記のようにクリープ（徐々に
進行する変形）とスナップアクション（急速に進行する変形）の段階的変位を行
い、後段のスナップアクションによって可動接点支持板３を押し上げられるよう
に両者間の距離を決定すればよい。本実施例では、バイメタル板７の一端側は可
動接点支持板３に密着、固定しているので、上記設定温度に対応した曲率のバイ
メタル板７を選択すれば良い。従って、前述したような上記距離の調整は必要な
く、組立も簡単である上に、前述したような上記距離の調整の誤差に起因するチ
ャタリングや接点熔着が起こることがない。第３図のOFF状態から第２図のON状態に移行する場合も、上記と同様にバイメ
タル板７は変形初期のクリープを経過してから変形が急速に進行し、可動接点４
が固定接点９に圧接する。バイメタル板７の上記のような変形により、チャタリ
ングを起こすことがなく、バイメタル板７や可動接点支持板３が疲労して正常な
動作をしなくなることがなく、また接点熔着も起こらず、スイッチ装置１は長期
間に亘ってスイッチ機能を失わず、電気機器の保護が確実になされる。バイメタル板７はその一部が可動接点支持板３の一部に密着し、更に可動接点
支持板３の一部は黄銅板６に密着している。従って、スイッチ装置１が第３図の
OFF状態から第２図のON状態に移行するとき、バイメタル板７は、共に昇温して
いる可動接点支持板３、黄銅板６から熱伝導による熱の供給を受けるので、自然
放冷の場合と異なって降温がゆっくりと進行する。従ってこのときスイッチ装置
１は第３図のOFF状態にある時間が長くなって、その間に電気機器の異常原因を
排除するのに好都合であり、電気機器のメンテナンスが容易になる。第５図及び第６図は上記のスイッチ装置を取付けた電動ドリルの把持部を示し
、第５図は側面図、第６図は一部破砕部分正面図である。第５図に示すように、把持部17の側面の蓋17ａに設けられた貫通孔には、パワ
ースイッチの釦16が突出している。図中、19はヒューズボックス、20は蓋取外し
用のレバーである。第５図に示すように、スイッチ装置１は蓋17ａの内側で把持
部17に取付けられ、リード線12、13が把持部17内の端子18Ａ、18Ｂに接続される
。本発明に基づくスイッチ装置は、種々の電気機器の保護に適用でき、その適用
範囲は広いが、とりわけ、バッテリ（乾電池を含む）パックの短絡からの保護、
小型モータの巻線に直結してその過負荷から保護するのに好適である。以上の実施例のほか、本発明の技術思想に基づいて種々の変形が可能である。
例えば、バイメタルの形状はクリープが起こる適宜の形状として良く、可動接点
の取付け位置もスイッチ装置の構造、形状に応じて適宜の形状として良い。また、保護の対象は、モータその他の電気機器のほか、種々の機械、装置を電
気的に保護或いは制御するのにも本発明に基づくスイッチ装置は適用可能である
。ヘ．発明の効果以上説明したように、本発明に基づくスイッチ装置は、温度変化に対応して変形する変位部材と可動接点を設けた可動部材とが可動接点とは別の位置でそれぞ
れの一端部を互いに重ね合わせて（密着して）固定され、かつ上記変位部材の他
端部が自由端となっているので、上記変位部材の自由端と上記可動部材との距離
は常にスイッチ切換時の温度の設定に適応した所望の距離とすることができる。
従って、従来のスイッチ装置に於けるような変位部材と可動部材との間の距離を
調整する必要がなく、組立が容易である。また、この調整の誤差に基づくチャタ
リングや接点熔着が起こることがなくなり、電気機器等の保護が長期間に亘って
確実になされ、信頼性が高い。DETAILED DESCRIPTION OF THE INVENTION BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a switch device, and more particularly, to a switch device that performs an opening / closing operation in response to a temperature change. B. 2. Description of the Related Art An electric machine such as a motor generates heat when it is in an abnormal state, and if it is used as it is, it becomes unusable due to burning of the insulating coating of the windings. In order to prevent this, a switch device (protection device) that uses a bimetal to open a contact by an abnormal current and an abnormal temperature and turns off the switch is used. The switch device has a structure shown in FIG. 7 to FIG. FIG. 7 is an internal plan view of the switch device 21, FIG. 8 is a sectional view taken along line VIII-VIII of FIG. 7, and FIG. 9 is an enlarged partial sectional view of FIG. The first conductive plate is provided on the bottom of the cold-rolled steel container 22 via an insulating plate 30A.
25, and a second conductive plate 28 is provided on the first conductive plate 25 via an insulating plate 30B. A movable contact support plate 23 is fixed to an end of the first conductive plate 25 by welding, and a movable contact 24 is attached to a distal end of the movable contact support plate 23. The bimetal plate 27 is fixed to the first conductive plate 25 by the fixture 31. The movable contact support plate 23 has its through hole 23b fitted into the fixture 31 without contact, and the movable contact 24 is connected to the second conductive plate 28.
It is in contact with the fixed contact 29 provided above. In this state, the movable contact support plate 23-2
The projecting portions 23a, 23a are separated from the bimetal plate 27 by the dimension d shown in FIG. 9, and the elasticity of the movable contact support plate 23 causes the movable contact 24 to press against the fixed contact 29, thereby causing the first and second protrusions 23a, 23a. Are electrically connected to each other, and the switch device 21 is in an ON state. The terminal portion 25a of the first conductive plate 25 is connected to the lead wire 33, and the terminal portion of the second conductive plate 28 is connected to the lead wire 32.
Connect to each. Although the terminal portions 25a and 28a are crimp terminals, the crimped state is not shown. The switch device 21 is mounted in an electric device (for example, a motor) not shown, and is connected in series between the electric device and a power supply. When the electric device causes some trouble during use and rises in temperature, and the switch device 21 rises in temperature, or when a large current flows and the movable contact support plate 23 is heated, the bimetal plate 27 also rises. As the temperature rises and deforms, it comes into contact with the projections 23a and 23a of the movable contact support plate 23, and when the deformation of the bimetal plate 23 further proceeds, the bimetal plate 27 pushes up the movable contact support plate 23 as shown in FIG. The movable contact 24 is separated from the fixed contact 29, the first and second conductive plates 25 and 28 are electrically cut off, and the switch device 21 is turned off to protect the electric equipment. However, when the state shown in FIG. 10 is reached, the movable contact support plate 23 and the bimetal plate 27 dissipate heat and cool down, and the bimetal plate 27 returns to its original shape and the protrusion 23a of the movable contact support plate 23
, 23a, the switch device returns to the state of FIG. 9 and is turned on again. As described above, if the time from when the switch device 21 is turned off to when it is turned on again is too short, the switch device 21 repeatedly turns on and off in a short cycle, which is inconvenient. Therefore, the distance d between the bimetal plate 27 and the projections 23a, 23a of the movable contact support plate 23 is adjusted according to the degree of curvature of the bimetal plate 27 and at the temperature at which the bimetal plate 27 is turned off (for example, within the range of 70 to 150 ° C.). (Predetermined temperature), the vertical position of the bimetal plate 27 is adjusted by fine adjustment means (not shown) provided on the fixture 31 so as to have a predetermined size corresponding to the predetermined temperature. For example, when the above-mentioned OFF temperature is 70 ° C., d is 1 mm, and when it is 100 ° C., d is 2 mm. However, this fine-tuning must be done manually for each item, which is tedious and difficult to achieve accuracy. If the interval d is too large, the switch device 21 is turned off after the electrical device has been in an abnormal state for a long time, and the protection of the electrical device becomes uncertain. On the other hand, if the interval d is too small, the ON / OFF state of the switch device 21 is reduced.
The repetition period of F becomes small, for example, ON and OFF are repeated at a period of 0.3 seconds (called chattering), and the bimetal plate 27 and the movable contact support plate 23 are already fatigued and normal deformation is performed. The ON state is maintained due to the disappearance, or the ON state is maintained due to the welding of the contacts due to the spark, and the electrical equipment cannot be protected. C. SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and does not require precise position adjustment of a displacement member (for example, bimetal) which deforms in response to a temperature change, does not cause chattering, and It is an object of the present invention to provide a highly reliable switch device that does not lose a switch function due to fatigue of the deformable member or contact welding. D. Configuration of the Invention That is, the present invention provides a fixed contact fixed to the accommodation portion, one end fixed to the accommodation portion, and another end provided with a movable contact that abuts the fixed contact. A movable member disposed so that an electric circuit is opened and closed by separating or contacting the movable contact with the fixed contact, and one end of the movable member with respect to the housing portion. The movable member has one end fixed in an overlapped state and a free end extending substantially in the same direction as the other end of the movable member. At normal temperature, the free contact is made such that the movable contact comes into contact with the fixed contact. The end is at a first position away from the movable member, and the temperature rises until the temperature reaches a predetermined temperature higher than the normal temperature.
Gradually, the free end approaches the movable member, and the temperature reaches the predetermined value.
When the temperature is reached, the deformation proceeds rapidly, and the free end is rapidly displaced to the second position while pushing the movable member with the one end as a fulcrum, thereby displacing the movable contact.
It is characterized by comprising a displacing member to be separated from a fixed contact, and a fixing member for fixing the one end of the movable member and the one end of the displacing member to the housing portion in a state of being overlapped. It relates to a switch device. E. Examples Hereinafter, examples of the present invention will be described. 1 and 2 show a switch device, FIG. 1 is an internal plan view of the switch device 1, and FIG. 2 is a cross-sectional view taken along line II-II of FIG. The conductive plate 8 is fixed on the bottom of the cold rolled steel plate housing 2 by the fixtures 15 and 15 via the insulating plate 10A. A fixed contact 9 is provided at one end of the conductive plate 8, and the other end is a terminal 8a. A resin base 14 is located on the conductive plate 8. On the base 14, near the end of the bimetal plate 7 and the end of the movable contact support plate (a movable member provided with movable contacts) 3 in order from the bottom. The brass plates 6 are mounted thereon, and the brass plates 6 are mounted thereon, and these are fixed to a resin base 14 by fixtures 11. By this fixation, a part of the bimetal plate 7, the end side of the movable contact support plate 3, and the brass plate 6 are adhered in this order from below. An insulating layer 10 </ b> B is provided on the upper surfaces of the brass plate 6 and the fixture 11, and is insulated from the housing 2. The bimetal plate 7 is curved downward, and its end opposite to the fixed side is a free end. A movable contact 4 is provided on the end of the movable contact support plate 3 opposite to the fixed side, and in a normal state, the movable contact 4 is fixed by the elasticity of the movable contact support plate 3 as shown in FIG. 9, the movable contact support plate 3 and the conductive plate 8 are electrically connected, and the switch device 1 is in the ON state. Movable contact support plate 3
A terminal 3a is formed at the end (right side in the figure) of the above fixed portion, and a terminal 8a is formed at the end (right side in the figure) opposite to the fixed contact 9 of the conductive plate 8. And terminal 3
a is connected to the lead wire 12, and the terminal 8a is connected to the lead wire 13, respectively. These connections are connected as crimp terminals, but the crimped state is not shown. FIG. 4 is a schematic circuit diagram showing an example of a connection between the switch device 1 and an electric device (a motor in this example). When the electric device raises the temperature due to some trouble during use, and the temperature of the switch device 1 is raised accordingly, or when a large current flows and the movable contact support plate 3 is heated, the bimetal plate 7 is It deforms and its free end moves upward, and eventually the bimetal plate 7
When the free end of the movable contact support plate 3 abuts against the wear-resistant contact plate 5 provided on the movable contact support plate 3 and the deformation of the bimetal plate 7 further proceeds, the movable contact support plate 3 is deformed as shown in FIG. The movable contact 4 is separated from the fixed contact 9 by being pushed by the plate 7 and warped upward, and the switch device 1 is turned off. What should be noted in this example is that the following phenomenon occurs in the process of switching the switch device 1 from the ON state to the OFF state. The bimetal plate 7 is bent downward in the second ON state, and is deformed so as to warp upward in the OFF state of FIG. 3 contrary to FIG. In the initial stage when the temperature of the bimetal plate 7 rises from the state of FIG. 2 to the state of FIG. 3, the bimetal plate gradually deforms as the temperature rises, and rapidly deforms when the bimetal plate has a predetermined shape. Progresses. That is, the deformation of the bimetal plate 7 gradually progresses until the deformation amount reaches the threshold value, and the deformation progresses rapidly when the deformation amount reaches this threshold value. The process in which the deformation gradually progresses in the early stage of the deformation is called creep (creeping). The movable contact support plate 3 is rapidly pushed upward by the rapid deformation progress (snap action) after the creep of the bimetal plate 7, so that the movable contact 4 is quickly separated from the fixed contact 9, and the contact is welded by spark. Never happen. The threshold value of the bimetal plate deformation amount varies depending on the temperature at which the switch device 1 is turned from the ON state to the OFF state. The higher the temperature, the larger the threshold value. Therefore, the distance between the free end of the bimetal plate 7 and the movable contact support plate in FIG. 2 may be determined according to the set temperature at which the switch device 1 is turned from the ON state to the OFF state. I mean
At the given set temperature, the bimetal plate 7 creeps (gradually) as described above.
Progressive deformation) and snap action (rapidly progressing deformation)
So that the movable contact support plate 3 can be pushed up by the subsequent snap action.
Then, the distance between them may be determined. In this embodiment , one end of the bimetal plate 7 is in close contact with and fixed to the movable contact support plate 3, so that the bimetal plate 7 having a curvature corresponding to the above set temperature may be selected. Therefore, the above-described adjustment of the distance is not required, the assembling is simple, and chattering and contact welding due to the error of the adjustment of the distance do not occur. Also in the case of transition from the OFF state in FIG. 3 to the ON state in FIG. 2, similarly to the above, the bimetal plate 7 undergoes a rapid deformation after the initial creep of the deformation, and the movable contact 4
Presses against the fixed contact 9. Such deformation of the bimetal plate 7 does not cause chattering, does not cause the bimetal plate 7 and the movable contact support plate 3 to become fatigued and malfunction, and does not cause contact welding. The device 1 does not lose the switch function for a long period of time, and the protection of the electric equipment is ensured. A part of the bimetal plate 7 is in close contact with a part of the movable contact supporting plate 3, and a part of the movable contact supporting plate 3 is in close contact with the brass plate 6. Therefore, the switch device 1 is
When transitioning from the OFF state to the ON state in FIG. 2, the bimetal plate 7 receives heat from the movable contact support plate 3 and the brass plate 6 that are both heated, and is supplied with heat by heat conduction. In contrast to this, the temperature decreases slowly. Therefore, at this time, the time during which the switch device 1 is in the OFF state shown in FIG. 3 becomes longer, and during that time, it is convenient to eliminate the cause of the abnormality of the electric device, and the maintenance of the electric device becomes easy. 5 and 6 show a gripping portion of the electric drill to which the above-mentioned switch device is attached, FIG. 5 is a side view, and FIG. 6 is a partially broken front view. As shown in FIG. 5, a button 16 of a power switch protrudes from a through hole provided in a lid 17a on a side surface of the grip portion 17. In the figure, 19 is a fuse box, and 20 is a lever for removing a lid. As shown in FIG. 5, the switch device 1 is attached to the holding portion 17 inside the lid 17a, and the lead wires 12, 13 are connected to the terminals 18A, 18B in the holding portion 17. INDUSTRIAL APPLICABILITY The switch device according to the present invention can be applied to protection of various electric devices and has a wide range of applications, particularly, protection from short-circuit of a battery (including a dry battery) pack,
It is suitable for directly connecting to the winding of a small motor to protect it from overload. In addition to the above embodiments, various modifications are possible based on the technical idea of the present invention.
For example, the shape of the bimetal may be an appropriate shape that causes creep, and the mounting position of the movable contact may be an appropriate shape according to the structure and shape of the switch device. In addition, the switch device according to the present invention is applicable to electrically protect or control various machines and devices in addition to motors and other electric devices to be protected. F. Effect of the Invention As described above, the switch device according to the present invention is configured such that the displacement member that deforms in response to a temperature change and the movable member provided with the movable contact have one end at a position different from the movable contact. are superposed with (adhesion to) fixed to each other, and the other end portion of the displacement member is a free end, the temperature always switch switching distance between the free end and the movable member of said displacement member It is possible to set a desired distance adapted to the setting.
Therefore, there is no need to adjust the distance between the displacement member and the movable member as in the conventional switch device, and assembly is easy. In addition, chattering and contact welding due to this adjustment error do not occur, and the protection of electric devices and the like is ensured for a long period of time, and the reliability is high.

【図面の簡単な説明】第１図〜第６図は本発明の実施例を示すものであって、第１図はスイッチ装置の内部平面図、第２図は第１図のII−II線矢視断面図、第３図はOFF状態にあるスイッチ装置の断面図、第４図はスイッチ装置とモータとの接続の概略回路図、第５図及び第６図はスイッチ装置を備えた電動ドリルの把持部を示し、第５図は
側面図、第６図は一部破砕正面図である。第７図〜第10図は従来例を示すものであって、第７図はスイッチ装置の内部平面図、第８図は第７図のVIII−VIII矢視断面図、第９図は第７図の部分拡大図、第10図はOFF状態にあるスイッチ装置の断面図である。なお、図面に示された符号に於いて、１、21・・・・・・スイッチ装置３、23・・・・・・可動接点支持板（可動部材） 24・・・・・・可動接点６・・・・・・黄銅板７、27・・・・・・・バイメタル板８、25、28・・・・・・導電板９、29・・・・・・固定接点 11、31・・・・・・固定具 12、13、32、33・・・・・・リード線 14・・・・・・樹脂の台である。BRIEF DESCRIPTION OF THE DRAWINGS FIGS. 1 to 6 show an embodiment of the present invention, FIG. 1 is an internal plan view of a switch device, and FIG. 2 is a line II-II in FIG. FIG. 3 is a sectional view of the switch device in an OFF state, FIG. 4 is a schematic circuit diagram of connection between the switch device and a motor, and FIGS. 5 and 6 are electric drills provided with the switch device. 5 is a side view, and FIG. 6 is a partially crushed front view. 7 to 10 show a conventional example, FIG. 7 is an internal plan view of the switch device, FIG. 8 is a sectional view taken along the line VIII-VIII of FIG. 7, and FIG. FIG. 10 is a partially enlarged view of FIG. 10, and FIG. 10 is a sectional view of the switch device in an OFF state. In addition, in the code | symbol shown in drawing, 1,21 ... Switch device 3,23 ... Movable contact support plate (movable member) 24 ... Movable contact 6 ... brass plates 7, 27 ... bimetal plates 8, 25, 28 ... conductive plates 9, 29 ... fixed contacts 11, 31 ... ... Fixtures 12, 13, 32, 33... Lead wires 14.

Claims

Claims: 1. A fixed contact fixed to a receiving part, one end fixed to the receiving part, and the other end provided with a movable contact abutting on the fixed contact. And a movable member arranged so that an electric circuit is opened and closed by separating or contacting the movable contact with the fixed contact, and one end of the movable member with respect to the housing portion. The movable member has one end fixed in an overlapping state and a free end extending substantially in the same direction as the other end of the movable member, so that the movable contact contacts the fixed contact at normal temperature. The free end is at a first position away from the movable member, and the temperature reaches a predetermined temperature higher than a normal temperature.
Until the free end is in contact with the movable member,
Approaching, and when the temperature reaches the predetermined temperature, the deformation starts to progress rapidly and the free end moves forward.
The movable member is rapidly displaced to the second position while pushing the movable member around the one end as a fulcrum.
A displacing member for separating the movable contact from the fixed contact, and a fixing member for fixing the movable member and one end of the displaceable member in an overlapping state with respect to the housing portion. A switch device, comprising: