JP4061204B2

JP4061204B2 - Manufacturing method of temperature sensor

Info

Publication number: JP4061204B2
Application number: JP2003023353A
Authority: JP
Inventors: 剛半沢; 雅彦西; 雅樹岩谷; 孝昭長曽我部
Original assignee: NGK Spark Plug Co Ltd
Current assignee: NGK Spark Plug Co Ltd
Priority date: 2003-01-31
Filing date: 2003-01-31
Publication date: 2008-03-12
Anticipated expiration: 2023-01-31
Also published as: JP2004233236A

Description

【０００１】
【発明の属する技術分野】
本発明は温度センサ及びその製造方法に関する。
【０００２】
【従来の技術】
従来、特許文献１記載の温度センサが知られている。この温度センサは、車両の排気通路に設けられ、排気ガスの温度を検出するために用いられるものである。この温度センサは、金属カバー、フランジ、ナット、外筒及びグロメットと、感温素子としてのサーミスタと、シースピンとを備えている。金属カバーは先端側が閉じられ、シースピンの一端側に被せて固定されている。金属カバー内には、温度を検知して電気信号として第１電極及び第２電極に出力するサーミスタが収納されている。また、シースピンは、筒状のシースと、シース内に絶縁状態で設けられた第１芯線及び第２芯線とからなる。金属カバー内において、シースピンの第１芯線はサーミスタの第１電極と接続され、シースピンの第２芯線はサーミスタの第２電極と接続されている。そして、第１、２電極及び第１、２芯線は、金属カバー内において、サーミスタとシースピンのシースとの間に挿入された絶縁ホルダに装着されている。
【０００３】
この温度センサによれば、第１、２電極が絶縁ホルダによって保持されているため、車両の振動等によりサーミスタに振動が加わっても、第１、２電極の振動が抑制される。そのため、この温度センサでは、第１、２電極の耐震性が向上し、第１、２電極の断線を防止することができる。
【０００４】
【特許文献１】
特開２００２−２６７５４７号公報
【０００５】
【発明が解決しようとする課題】
しかし、上記従来の温度センサでは、第１、２電極及び第１、２芯線の重なり部をレーザー溶接等により溶接した後、第１、２電極及び第１、２芯線を絶縁ホルダに装着している。そのため、第１、２電極と第１、２芯線との溶接のためにのみ用いられる治具が別途必要となる。さらには、絶縁ホルダが穴部に対応する部位にて穴部の軸線方向に沿って分割された２個の分割部材からなるため、部品点数が増加する。これらのことから、この温度センサでは、製造コストの高騰化を招いてしまう。また、この温度センサでは、第１、２電極及び第１、２芯線を絶縁ホルダに装着する際、穴部までもが分割されて形成されているために第１、２電極や第１、２芯線がその分割された穴部に対し位置ずれを生じ易く、分割部材の間に第１、２電極や第１、２芯線を挟んでしまい、絶縁性を損なう虞もある。
【０００６】
本発明は、上記従来の実情に鑑みてなされたものであって、第１、２電極及び第１、２芯線が互いに確実に絶縁されるとともに、製造コストの低廉化を実現することのできる温度センサを提供することを解決すべき課題としている。
【００１１】
【課題を解決するための手段】
第１発明の温度センサの製造方法は、先端が閉じられた有底筒状の金属カバーと、温度を検知して電気信号として第１電極及び第２電極に出力可能な感温素子と、内部に絶縁状態で第１芯線及び第２芯線が設けられたシースピンとを少なくとも用意する第１工程と、
【００１２】
両側を絶縁状態に離反させる仕切部と、該仕切部の一方側に開く第１挿入口と、該仕切部の他方側に開く第２挿入口とを有する単一の絶縁ホルダであって、該第１挿入口の内径が該第１電極の外径と該第１芯線の外径との合計と略同等に形成されるとともに、該第２挿入口の内径が該第２電極の外径と該第２芯線の外径との合計と略同等に形成されてなる絶縁ホルダを用意する第２工程と、
【００１３】
該絶縁ホルダの該第１挿入口内に、該第１電極と該第１芯線との重なり部が該第１挿入口の開口側に露出するように、該第１電極と該第１芯線とを挿入して重ね合わせる一方、該第２挿入口内に、該第２電極と該第２芯線との重なり部が該第２挿入口の開口側に露出するように、該第２電極と該第２芯線とを挿入して重ね合わせる第３工程と、
【００１４】
該絶縁ホルダの該第１挿入口内に位置する該第１電極と該第１芯線との前記重なり部を接合し、該第２挿入口内に位置する該第２電極と該第２芯線との前記重なり部を接合する第４工程と、
【００１５】
該絶縁ホルダとともに該感温素子を該金属カバー内に収納し、該金属カバーと該シースピンとを固定する第５工程とを備えていることを特徴とする。
また、第２発明の温度センサの製造方法は、先端が閉じられた有底筒状の金属カバーと、温度を検知して電気信号として第１電極及び第２電極に出力可能な感温素子と、内部に絶縁状態で第１芯線及び第２芯線が設けられたシースピンとを少なくとも用意する第１工程と、
両側を絶縁状態に離反させる仕切部と、該仕切部の一方側に開く第１挿入口と、該仕切部の他方側に開く第２挿入口とを有する単一の絶縁ホルダを用意する第２工程と、
該絶縁ホルダの該第１挿入口内に、該第１電極又は該第１芯線の外径の小さいほうが該第１挿入口の開口側に位置するように、該第１電極と該第１芯線とを挿入して重ね合わせる一方、該第２挿入口内に、該第２電極又は該第２芯線の外径の小さいほうが該第２挿入口の開口側に位置するように、該第２電極と該第２芯線とを挿入して重ね合わせる第３工程と、
該絶縁ホルダの該第１挿入口内に位置する該第１電極と該第１芯線との重なり部を接合し、該第２挿入口内に位置する該第２電極と該第２芯線との重なり部を接合する第４工程と、
該絶縁ホルダとともに該感温素子を該金属カバー内に収納し、該金属カバーと該シースピンとを固定する第５工程とを備えていることを特徴とする。
【００１６】
第１、２発明の製造方法では、まず第１工程において、先端が閉じられた金属カバーと、温度を検知して電気信号として第１電極及び第２電極に出力可能な感温素子と、内部に絶縁状態で第１芯線及び第２芯線が設けられたシースピンとを少なくとも用意する。また、第２工程において、両側を絶縁状態に離反させる仕切部と、この仕切部の一方側に開く第１挿入口と、仕切部の他方側に開く第２挿入口とを有する単一の絶縁ホルダを用意する。
【００１７】
そして、第３工程において、絶縁ホルダの第１挿入口内に第１電極と第１芯線とを挿入して重ね合わせ、第２挿入口内に第２電極と第２芯線とを挿入して重ね合わせる。挿入して重ね合わせる際、第１電極及び第１芯線と第２電極及び第２芯線とを重ねた状態で挿入することも可能である。このとき、本発明では、第１電極及び第１芯線と第２電極及び第２芯線とを挿入、配置させるための一対の挿入口が、従来のように分割した絶縁ホルダ同士を重ねて形成されるのではなく、単一の絶縁ホルダに仕切部を隔てて凹設されている。このため、第１電極及び第１芯線、第２電極及び第２芯線を各挿入口に容易に挿入させつつ、両者を重ね合わせることができる。また、各挿入口に各電極及び各芯線を挿入（配置）した後、電極及び芯線の周囲は挿入口内周面に包囲されることになるため、電極及び芯線の挿入口内における位置ずれが生じ難く、後述する第４工程における電極と芯線との重なり部の接合を良好に行うことができる。さらに、一対の挿入口が、単一の絶縁ホルダに対して仕切部の両側に開く形態で形成（凹設）されているので、各挿入口に電極及び芯線を挿入した状態を画像処理等で確認し易く、後述する第４工程における電極と芯線との接合を確実に行うことも可能となる。
【００１８】
そして、第４工程において、絶縁ホルダの第１挿入口内に位置する第１電極と第１芯線との重なり部を接合し、第２挿入口内に位置する第２電極と第２芯線との重なり部を接合する。つまり、本発明の製造方法では、絶縁ホルダが、温度センサ実使用時の第１、２電極及び第１、２芯線との互いの絶縁を図る機能を果たす他に、第１電極と第１芯線とを接合する治具、並びに第２電極と第２芯線とを接合する治具の働きを兼ねている。そのため、第１電極と第１芯線、第２電極と第２芯線とを接合する治具を従来のように別途用意する必要がない。また、第１電極と第１芯線とを第１挿入口内に挿入した状態で、さらに第２電極と第２芯線とを第２挿入口内に挿入した状態で直接接合を行うことから、接合の作業を簡単に行うことができる。
【００１９】
この後、第５工程において、絶縁ホルダとともに感温素子を金属カバー内に収納し、金属カバーとシースピンとを固定する。こうして、温度センサを得る。
そして、第１、２発明の温度センサの製造方法により得られた温度センサでは、絶縁ホルダが単一の部材からなるため、部品点数が減少する。また、この温度センサでは、仕切部の一方側に開く第１挿入口と、仕切部の他方側に開く第２挿入口とを有する単一の絶縁ホルダを備えているため、第１電極及び第１芯線と、第２電極及び第２芯線とを単一の絶縁ホルダの仕切部によって離反させることができるとともに、第１電極と第１芯線との接合部及び第２電極と第２芯線との接合部を各挿入口内に確実に配置させることができる。そのため、絶縁ホルダの挿入口に対する電極及び芯線の位置ずれが生じ難く、第１電極及び第１芯線と、第２電極及び第２芯線との間が互いに確実に絶縁される。したがって、第１、２発明の温度センサでは、第１、２電極及び第１、２芯線が互いに確実に絶縁されるとともに、コストの低廉化を実現することができる。
【００２０】
上記第４工程における接合の手法は特に限定されず、レーザー溶接、アルゴン溶接、ロー付け接合等を挙げることができる。なお、電極と芯線との溶接強度を良好に得るために、また挿入口といった狭い領域に位置する電極と芯線との重なり部への接合を実施することを考慮すると、レーザー溶接を採用することが好ましい。
【００２１】
また、第１発明の製造方法では、上記第２工程にて、第１挿入口（第２挿入口）の内径を第１電極（第２電極）の外径と第１芯線（第２芯線）の外径との合計と略同等に形成した単一の絶縁ホルダを用意し、上記第３工程にて、第１電極（第２電極）と第１芯線（第２芯線）との重なり部が第１挿入口（第２挿入口）の開口側に露出するように両者を該第１挿入口（第２挿入口）内に挿入させる。こうすることにより、上記第４工程において、挿入口内における電極と芯線との重なり部（接合面）を接触維持させるための押え作業等を行わなくとも両者の当接状態を維持することができ、電極と芯線との重なり部に対し確実に接合を行え、接合の作業をより簡便にすることができる。
【００２２】
また、第２発明の製造方法では、第３工程にて、第１挿入口（第２挿入口）の開口方向（絶縁ホルダの軸方向に直交する方向）に第１電極（第２電極）及び第１芯線（第２芯線）を重ねて配置させる場合には、第１電極（第２電極）又は第１芯線（第２芯線）の外径の小さいほうが第１挿入口（第２挿入口）の開口側に位置するように両者を配置させる。こうすることにより、上記第４工程にて電極と芯線との重なり部を接合する前段階にて、電極と芯線との配置位置を画像処理等により良好に確認することが可能となり、両者の位置だしを精度良く行え、ひいては電極と芯線との重なり部の接合を良好に行うことができる。
【００２３】
第１、２発明の温度センサにおいては、絶縁ホルダの最大外径をｄ、この最大外径の位置に対応する金属カバーの内径をＤとしたときに、Ｄ−ｄ≦０．２ｍｍの関係を満たすことが好ましい。これにより、絶縁ホルダが金属カバー内に好適に保持されることから、温度センサ自身に振動が加わっても、絶縁ホルダが金属カバーの内周面によって振れが抑えられることになり、第１、２電極及び第１、２芯線の振動が有効に抑制され、第１、２電極及び第１、２芯線の断線を防止することができる。
【００２４】
第１、２発明の温度センサにおいては、絶縁ホルダは、第１挿入口及び第２挿入口が同一方向に向かって開いているものを採用することができる。絶縁ホルダの第１挿入口及び第２挿入口が同一方向に向かって開いていれば、第１電極、第１芯線及び第２電極、第２芯線を絶縁ホルダの第１、２挿入口に挿入した後、そのままの状態で第１電極、第１芯線及び第２電極、第２芯線を連続して溶接できるため、作業性が良好である。この場合、絶縁ホルダの軸方向に直交する断面形状が略Ｅ字型であることができる。軸方向に直交する断面形状が略Ｅ字型である絶縁ホルダであれば、構造が簡単であり、比較的容易に製造することができる。
【００２５】
また、第１、２発明の温度センサにおいては、絶縁ホルダは、第１挿入口及び第２挿入口が逆方向に向かって開いているものを採用することもできる。絶縁ホルダの第１挿入口及び第２挿入口が逆方向に向かって開いていれば、第１電極、第１芯線及び第２電極、第２芯線の間の絶縁性が特に良好になる。このような絶縁ホルダとして、軸方向に直交する断面形状が略Ｈ字型であるものや略Ｓ字型であるものを採用することができる。
【００２６】
【発明の実施の形態】
以下、第１、２発明の温度センサ、その製造方法及び温度センサ用絶縁ホルダを具体化した実施形態１〜３を図面を参照しつつ説明する。
【００２７】
（実施形態１）
図１に実施形態１の温度センサ１００の部分破断断面図を示す。この温度センサ１００は、車両の排気通路に設けられ、排気ガスの温度を広範囲にわたって検出するために用いられる。この温度センサは、金属カバー１、フランジ１２、ナット１３、外筒１０及びグロメット１８と、感温素子としてのサーミスタ２と、シースピン３とを備えている。
【００２８】
ステンレス等の金属からなる有底筒状の金属カバー１は、図２に示すように、細部１ａと大径部１ｂとからなり、細部１ａの先端が閉じられ、大径部１ｂは開口部を有している。この大径部１ｂの開口部側がシースピン３の一端側３ａの外側面に被せられて、全周レーザー溶接によって固定されている。金属カバー１の細部１ａには、温度を検知して電気信号として第１電極２ａ及び第２電極２ｂ（Ｐｔ−Ｒｈ合金線等から形成）に出力するサーミスタ２が設けられている。また、シースピン３は、ステンレス等の金属からなる筒状のシース内に第１芯線４及び第２芯線５を収納し、両芯線４、５とシースとの間にシリカ等の絶縁粉末を充填してなるものである。金属カバー１内において、シースピン３の第１芯線４の一端側４ａはサーミスタ２の第１電極２ａとレーザー溶接により接続され、シースピン３の第２芯線５の一端側５ａはサーミスタ２の第２電極２ｂとレーザー溶接により接続されている。そして、第１、２電極２ａ、２ｂ及び第１、２芯線４、５の一端側４ａ、５ａは、金属カバー１内において、サーミスタ２とシースピン３の一端側３ａとの間に挿入されたアルミナからなる絶縁ホルダ６に装着されている。なお、この実施形態１の温度センサ１００では、絶縁ホルダ６の最大外径をｄ、この最大外径の位置に対応する金属カバー１の内径をＤとしたときに、Ｄ−ｄ＝０．１（ｍｍ）となるように設計されており、振動に伴う絶縁ホルダ６の振れが金属カバー１の内周面により有効に抑制可能な構造になっている。
【００２９】
絶縁ホルダ６は、図３に示すように、外形が略円柱形状の単一の部材である絶縁性のセラミックスからなり、軸方向に直交する断面の形状が略Ｅ字型をなしている。周面に同一方向に向かって開く第１挿入口６ａ及び第２挿入口６ｂは軸方向に平行に凹設され、第１挿入口６ａと第２挿入口６ｂとの間に仕切部６ｄが形成されている。仕切部６ｄの幅ｔ２は、機械的強度等を考慮して０．１ｍｍ以上となっている。
【００３０】
また、図１に示すように、シースピン３は、自身の他端側３ｂがフランジ１２の内側に挿通された状態で、フランジ１２に対して固定されている。このフランジ１２は、軸線方向に延びる鞘部１２ｂと、この鞘部１２ｂの一端側に位置し、径方向外側に向かって突出する突出部１２ａとを有している。突出部１２ａは、一端側に図示しない排気管の取付部のテーパ部に対応したテーパ形状をなす座面１２ｃを有する環状に形成されており、座面１２ｃが上記取付部のテーパ部に密着することで、排気ガスが排気ガス管外部へ漏出するのを防止するようになっている。なお、シースピン３はフランジ１２に対して圧入され、全周レーザー溶接によって隙間なく固定されている。フランジ１２の周囲には、六角ナット部１３ａ及びネジ部１３ｂを有するナット１３が回動自在に嵌挿されている。温度センサ１は、排気管の取付部にフランジ１２の突出部１２ａの座面１２ｃを当接させ、ナット１３により固定される。また、フランジ１２の鞘部１２ｂの径方向外側には、筒状の外筒１０の一端側１０ａが気密状態で同軸上に接合（例えば、全周レーザー溶接）されている。外筒１０内において、第１、２芯線４、５の他端側４ｂ、５ｂが第１、２リード線１４、１５の一端側１４ａ、１５ａとカシメ端子１６によりかしめられている。また、他端側４ｂ、５ｂと一端側１４ａ、１５ａには、カシメ端子１６とともに絶縁チューブ１７が被せられている。そして、外筒１０の他端側１０ｂの内部には、第１、２リード線１４、１５を挿通するための第１、２リード線挿通口１８ａ、１８ｂが形成された耐熱ゴム製のグロメット１８が配置され、他端側１０ｂを径方向内側にかしめることによって、グロメット１８は外筒１０に固定されている。
【００３１】
この温度センサ１００の製造方法について説明する。まず、第１工程において、金属カバー１とサーミスタ２とシースピン３とを用意し、第２工程において、絶縁ホルダ６を用意する。
【００３２】
第３工程において、絶縁ホルダ６の第１挿入口６ａ内に第１電極２ａと第１芯線４とを挿入して重ね合わせ、第２挿入口６ｂ内に第２電極２ｂと第２芯線５とを挿入して重ね合わせる。
【００３３】
なお、この実施形態１では、第１、２電極２ａ、２ｂと第１、２芯線４、５との外径を比較したときに、第１、２電極２ａ、２ｂの方が小さく調整されている。そこで、第１挿入口６ａ内に第１電極２ａと第１芯線４とを挿入し重ね合わせるにあたり、第１電極２ａが第１挿入口６ａの開口側に位置するように挿入している。このように第１電極２ａと第１芯線４とを第１挿入口６ａに挿入、配置させることで、後述する第４工程にて第１電極２ａと第１芯線４との重なり部を接合する前段階にて、両者の位置出しを精度良く行うことができる。なお、第２挿入口６ｂに対する第２電極２ｂ、第２芯線５の挿入についても同様である。
【００３４】
また、この実施形態１の絶縁ホルダ６では、仕切部６ｄのうちで第１、２電極２ａ、２ｂと第１、２芯線４、５とが挿入される側に、外側に向かうほど幅狭となる面取り部（この実施形態１では直線状に面取りを行った部分であるＣ面）６ｃが形成されている。このように仕切部６ｄに面取り部６ｃを形成することによって、上記第３工程において、第１、２挿入口６ａ、６ｂに対する第１、２電極２ａ、２ｂ及び第１、２芯線４、５の挿入を円滑に行うことができる。
【００３５】
また、第４工程において、絶縁ホルダ６の第１挿入口６ａ内に位置する第１電極２ａと第１芯線４との重なり部を接合し、第２挿入口６ｂ内に位置する第２電極２ｂと第２芯線５との重なり部を接合する。
【００３６】
そして、第５工程において、絶縁ホルダ６とともにサーミスタ２を金属カバー１内に収納し、シースピン３の一端側３ａと金属カバー１の大径部１ｂとの重なり部を全周レーザー溶接により固定する。その後、第１、２芯線４、５の他端４ｂ、５ｂと第１、２リード線１４、１５の一端１４ａ、１５ａとをカシメ端子１６により接続し、絶縁チューブ１７を被せた後、外筒１０、フランジ１２、ナット１３及びグロメット１８を組み付けて、温度センサ１００が完成する。
【００３７】
以上の構成をした実施形態１の温度センサ１００では、排気ガスの温度が金属カバー１の細部１ａを介してサーミスタ２に伝達され、その温度に応じてサーミスタ２の抵抗値が変化する。そして、このサーミスタ２の抵抗が電気信号として、第１、２電極２ａ、２ｂ及び第１、２芯線４、５を介して第１、２リード線１４、１５から取り出される。こうして、第１、２リード線１４、１５から取り出される電気信号により、排気ガスの温度を検知することができる。
【００３８】
この温度センサ１００では、第１電極２ａと第１芯線４の一端側４ａとの重なり部は絶縁ホルダ６の第１挿入口６ａ内で位置決めされるとともにレーザー溶接され、第２電極２ｂと第２芯線５の一端側５ａとは絶縁ホルダ６の第２挿入口６ｂ内で位置決めされるとともにレーザー溶接される。つまり、絶縁ホルダ６が第１、２電極２ａ、２ｂと第１、２芯線４、５とを溶接する治具の働きを兼ねている。そのため、第１、２電極２ａ、２ｂと第１、２芯線４、５とを溶接する治具を別途用意する必要がない。また、第１電極２ａ、第１芯線４の一端側４ａ及び第２電極２ｂ、第２芯線５の一端側５ａを絶縁ホルダ６の第１、２挿入口６ａ、６ｂに挿入した状態でレーザー溶接できる。そのため、レーザー溶接の作業が簡単である。
【００３９】
また、この温度センサ１００では、絶縁ホルダ６が単一の部材からなるため、部品点数が減少する。
【００４０】
さらに、この温度センサ１００では、第１電極２ａ及び第１芯線４の一端側４ａと第２電極２ｂ及び第２芯線５の一端側５ａとが単一の絶縁ホルダ６の仕切部６ｄによって離反され、作業ミスを生じないため、両者が互いに確実に絶縁される。
【００４１】
また、この温度センサ１００では、第１電極２ａ及び第１芯線４の一端側４ａと第２電極２ｂ及び第２芯線５の一端側５ａとが絶縁ホルダ６によって金属カバー１に保持されている。そのため、金属カバー１内にセメントを用いてサーミスタ２等を固定しなくても、サーミスタ２に振動が加わった場合の第１、２電極２ａ、２ｂ及び第１、２芯線４、５の振動が抑制されるため、製造コストの低廉化と第１、２電極２ａ、２ｂ及び第１、２芯線４、５の断線の防止とを実現することができる。
【００４２】
さらに、この温度センサ１００では、絶縁ホルダ６の第１挿入口６ａ及び第２挿入口６ｂが同一方向に向かって開いているため、第１電極２ａ、第１芯線４の一端側４ａ及び第２電極２ｂ、第２芯線５の一端側５ａを絶縁ホルダ６の第１、２挿入口６ａ、６ｂに挿入した後、そのままの状態で第１電極２ａ、第１芯線４の一端側４ａ及び第２電極２ｂ、第２芯線５の一端側５ａを連続してレーザー溶接できるため、作業性が良好である。特に、絶縁ホルダ６の軸方向に直交する断面の形状が略Ｅ字型であるため、構造が簡単であり、比較的容易に製造することができる。
【００４３】
したがって、この温度センサ１００によれば、第１電極２ａ及び第１芯線４並びに第２電極２ｂ及び第２芯線５が互いに確実に絶縁されるとともに、製造コストの低廉化を実現することができる。
【００４４】
（実施形態２）
実施形態２の温度センサは、図４に示す絶縁ホルダ２６を用いている。この絶縁ホルダ２６は、外形が略円柱形状の単一の部材である絶縁性のセラミックスからなり、軸方向に直交する断面の形状が略Ｈ字型をなしている。周面に逆方向に向かって開く第１挿入口２６ａ及び第２挿入口２６ｂは軸方向に平行に凹設され、第１挿入口２６ａと第２挿入口２６ｂとの間に仕切部２６ｄが形成されている。仕切部２６ｄの幅ｔ４は、機械的強度を考慮して０．１ｍｍ以上となっている。
【００４５】
また、この実施形態２の温度センサにおいても、第１挿入口２６ａ及び第２挿入口２６ｂ内に第１電極２ａ及び第１芯線４の一端側４ａ、第２電極２ｂ及び第２芯線５の一端側５ａを挿入した上で両者を重ね合わせ、両重なり部に対してレーザー溶接を行い、電極と芯線との接続を図っている。
【００４６】
なお、この断面形状が略Ｈ字型をなした絶縁ホルダ２６の第１挿入口２６ａ及び第２挿入口２６ｂの内径ｔ３は、第１電極２ａ（第２電極２ｂ）の外径と第１芯線４（第２芯線５）の外径との合計と略同等の寸法に形成されている。そして、この実施形態２では、図示はしないが、第１電極２ａと第１芯線４との重なり部が第１挿入口２６ａの開口側に露出するように、該重なり部を該第１挿入口２６ａ内に配置させる。なお、第２挿入口２６ｂに対する第２電極２ｂと第２芯線５の挿入についても同様とする。このように、第１電極２ａ及び第１芯線４、第２電極２ｂ及び第２芯線５を第１、２挿入口２６ａ、２６ｂに配置させることで、電極と芯線との重なり部（接合面）を良好に接触させた状態を維持することができ、電極と芯線との重なり部を押える押え作業等を行わずに、両者のレーザー溶接を良好に行うことができる。また、この実施形態２の絶縁ホルダ２６では、仕切部２６ｄのうちで第１、２電極２ａ、２ｂと第１、２芯線４、５とが挿入される側に、外側に向かうほど幅狭となる面取り部（この実施形態２では曲線状に面取りを行った部分であるＲ面）２６ｃが形成されている。これにより、第１、２挿入口２６ａ、２６ｂに対する第１、２電極２ａ、２ｂ及び第１、２芯線４、５の挿入を円滑に行うことができる。
【００４７】
この温度センサでは、絶縁ホルダ２６により、第１電極２ａ、第１芯線４及び第２電極２ｂ、第２芯線５の間の絶縁性が特に良好になる。
【００４８】
（実施形態３）
実施形態３の温度センサは、図５に示す絶縁ホルダ３６を用いている。この絶縁ホルダ３６も、外形が略円柱形状の単一の部材である絶縁性のセラミックスからなり、軸方向に直交する断面の形状が略Ｓ字型をなしている。周面に逆方向に向かって開く第１挿入口３６ａ及び第２挿入口３６ｂは軸方向に平行に凹設され、第１挿入口３６ａと第２挿入口３６ｂとの間に仕切部３２ｄが形成されている。仕切部３６ｄの幅ｔ６は、機械的強度等を考慮して０．１ｍｍ以上となっている。
【００４９】
この温度センサにおいても、絶縁ホルダ３６により、第１電極２ａ、第１芯線４及び第２電極２ｂ、第２芯線５の間の絶縁性が特に良好になる。
【００５０】
本発明は、上述した具体的な実施形態に限られず、目的、用途に応じて本発明の範囲内で種々変更した実施形態とすることができる。例えば、絶縁ホルダ６、２６、３６は単一部材で形成されれば良く、その形状は略円柱形状に限定されない。
【００５１】
さらに、第１電極２ａと第１芯線４の一端側４ａとの重なり部の接合や第２電極２ｂと第２芯線５の一端側５ａとの重なり部の接合は、実施形態１〜３のようにレーザー溶接に限られず、アルゴン溶接やロー付け溶接等によって行っても良い。また、金属カバー１の形状は、実施形態１のように段付形状でなく、略真っ直ぐな筒形状となっていても良い。
【図面の簡単な説明】
【図１】実施形態１の温度センサ、その製造方法及び温度センサ用絶縁ホルダに係り、温度センサの部分破断断面図である。
【図２】実施形態１の温度センサ、その製造方法及び温度センサ用絶縁ホルダに係り、温度センサの一部拡大断面図である。
【図３】実施形態１の温度センサ、その製造方法及び温度センサ用絶縁ホルダに係り、絶縁ホルダの斜視図である。
【図４】実施形態２の温度センサ、その製造方法及び温度センサ用絶縁ホルダに係り、絶縁ホルダの斜視図である。
【図５】実施形態３の温度センサ、その製造方法及び温度センサ用絶縁ホルダに係り、絶縁ホルダの斜視図である。
【符号の説明】
１…金属カバー
２…感温素子（サーミスタ）
２ａ…第１電極
２ｂ…第２電極
３…シースピン
４…第１芯線
５…第２芯線
６、２６、３６…絶縁ホルダ
６ａ、２６ａ、３６ａ…第１挿入口
６ｂ、２６ｂ、３６ｂ…第２挿入口
６ｄ、２６ｄ、３６ｄ…仕切部[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a temperature sensor and a manufacturing method thereof.
[0002]
[Prior art]
Conventionally, a temperature sensor described in Patent Document 1 is known. This temperature sensor is provided in the exhaust passage of the vehicle and is used to detect the temperature of the exhaust gas. This temperature sensor includes a metal cover, a flange, a nut, an outer cylinder and a grommet, a thermistor as a temperature sensitive element, and a sheath pin. The metal cover is closed at the front end side, and is fixed on one end side of the sheath pin. The thermistor which detects temperature and outputs it as an electrical signal to the first electrode and the second electrode is housed in the metal cover. The sheath pin includes a cylindrical sheath and a first core wire and a second core wire provided in an insulated state in the sheath. In the metal cover, the first core wire of the sheath pin is connected to the first electrode of the thermistor, and the second core wire of the sheath pin is connected to the second electrode of the thermistor. The first and second electrodes and the first and second core wires are attached to an insulating holder inserted between the thermistor and the sheath of the sheath pin in the metal cover.
[0003]
According to this temperature sensor, since the first and second electrodes are held by the insulating holder, even if vibration is applied to the thermistor due to vehicle vibration or the like, vibration of the first and second electrodes is suppressed. Therefore, in this temperature sensor, the earthquake resistance of the first and second electrodes is improved, and disconnection of the first and second electrodes can be prevented.
[0004]
[Patent Document 1]
JP 2002-267547 A
[0005]
[Problems to be solved by the invention]
However, in the above conventional temperature sensor, after welding the overlapping portion of the first and second electrodes and the first and second core wires by laser welding or the like, the first and second electrodes and the first and second core wires are attached to the insulating holder. Yes. Therefore, a jig that is used only for welding the first and second electrodes and the first and second core wires is required separately. Furthermore, since the insulating holder is composed of two divided members that are divided along the axial direction of the hole at a portion corresponding to the hole, the number of parts increases. For these reasons, this temperature sensor leads to an increase in manufacturing cost. Further, in this temperature sensor, when the first and second electrodes and the first and second core wires are attached to the insulating holder, the holes are also divided so that the first and second electrodes and the first and second electrodes are formed. The core wire is likely to be displaced with respect to the divided holes, and the first and second electrodes and the first and second core wires are sandwiched between the divided members, which may impair insulation.
[0006]
The present invention has been made in view of the above-described conventional circumstances, and the temperature at which the first and second electrodes and the first and second core wires are reliably insulated from each other and the manufacturing cost can be reduced. Providing a sensor is an issue to be solved.
[0011]
[Means for Solving the Problems]
  FirstThe manufacturing method of the temperature sensor of the invention includes a bottomed cylindrical metal cover having a closed tip, a temperature sensing element capable of detecting the temperature and outputting the electric signal to the first electrode and the second electrode, and insulating inside A first step of preparing at least a sheath pin provided with a first core wire and a second core wire in a state;
[0012]
  A single insulating holder having a partition part that separates both sides in an insulated state, a first insertion port that opens on one side of the partition part, and a second insertion port that opens on the other side of the partition partThe inner diameter of the first insertion port is formed substantially equal to the sum of the outer diameter of the first electrode and the outer diameter of the first core wire, and the inner diameter of the second insertion port is the second Insulating holder formed substantially equal to the sum of the outer diameter of the electrode and the outer diameter of the second core wireA second step of preparing
[0013]
  In the first insertion port of the insulating holderThe overlapping portion between the first electrode and the first core wire is exposed to the opening side of the first insertion port.The first electrode and the first core wire are inserted and overlappedWhileIn the second insertion slotThe overlapping portion of the second electrode and the second core wire is exposed on the opening side of the second insertion port.A third step of inserting and overlapping the second electrode and the second core wire;
[0014]
  The first electrode positioned in the first insertion port of the insulating holder and the first core wireSaidThe overlapping portion is joined, and the second electrode located in the second insertion port and the second core wireSaidA fourth step of joining the overlapping portions;
[0015]
  The thermosensitive element is housed in the metal cover together with the insulating holder, and a fifth step of fixing the metal cover and the sheath pin is provided.
  Further, the manufacturing method of the temperature sensor of the second invention includes a bottomed cylindrical metal cover having a closed end, a temperature sensing element capable of detecting the temperature and outputting the electric signal to the first electrode and the second electrode. A first step of preparing at least a sheath pin provided with a first core wire and a second core wire in an insulated state inside;
  Preparing a single insulating holder having a partition part that separates both sides in an insulated state, a first insertion port that opens on one side of the partition part, and a second insertion port that opens on the other side of the partition part; Process,
  In the first insertion port of the insulating holder, the first electrode and the first core wire are arranged so that the smaller outer diameter of the first electrode or the first core wire is located on the opening side of the first insertion port. And inserting the second electrode and the second core so that the smaller outer diameter of the second electrode or the second core wire is located on the opening side of the second insertion port. A third step of inserting and overlapping the second core wire;
  The overlapping portion between the first electrode located in the first insertion port of the insulating holder and the first core wire is joined, and the overlapping portion between the second electrode located in the second insertion port and the second core wire A fourth step of bonding
  The thermosensitive element is housed in the metal cover together with the insulating holder, and a fifth step of fixing the metal cover and the sheath pin is provided.
[0016]
  1st and 2ndIn the manufacturing method of the invention, first, in the first step, a metal cover whose tip is closed, a temperature sensing element capable of detecting the temperature and outputting it as an electrical signal to the first electrode and the second electrode, and an insulating state inside. At least a sheath pin provided with a first core wire and a second core wire is prepared. Also, in the second step, a single insulation having a partition part that separates both sides in an insulated state, a first insertion port that opens on one side of the partition part, and a second insertion port that opens on the other side of the partition part Prepare a holder.
[0017]
In the third step, the first electrode and the first core wire are inserted and overlapped in the first insertion port of the insulating holder, and the second electrode and the second core wire are inserted and overlapped in the second insertion port. When inserting and overlapping, it is also possible to insert the first electrode and the first core wire in a state where the second electrode and the second core wire are overlapped. At this time, in the present invention, a pair of insertion openings for inserting and arranging the first electrode and the first core wire and the second electrode and the second core wire are formed by overlapping the insulating holders divided as in the prior art. Instead, the single insulating holder is recessed with a partitioning portion. For this reason, both can be overlap | superposed, inserting a 1st electrode, a 1st core wire, a 2nd electrode, and a 2nd core wire into each insertion port easily. Further, after each electrode and each core wire are inserted (arranged) into each insertion port, the periphery of the electrode and the core wire is surrounded by the inner peripheral surface of the insertion port, so that the displacement of the electrode and the core wire in the insertion port is unlikely to occur. Thus, it is possible to satisfactorily join the overlapping portion between the electrode and the core wire in the fourth step described later. Furthermore, since the pair of insertion openings are formed (recessed) in such a way as to open on both sides of the partition part with respect to a single insulating holder, the state in which the electrodes and core wires are inserted into each insertion opening can be obtained by image processing or the like. It is easy to confirm, and it becomes possible to reliably join the electrode and the core wire in the fourth step described later.
[0018]
And in a 4th process, the overlapping part of the 1st electrode and 1st core wire which are located in the 1st insertion slot of an insulating holder is joined, and the overlapping part of the 2nd electrode and 2nd core wire which are located in the 2nd insertion slot Join. In other words, in the manufacturing method of the present invention, the insulating holder serves to insulate the first and second electrodes and the first and second core wires from each other when the temperature sensor is actually used. And a jig for joining the second electrode and the second core wire. Therefore, it is not necessary to separately prepare a jig for joining the first electrode and the first core wire and the second electrode and the second core wire as in the prior art. Further, since the first electrode and the first core wire are inserted into the first insertion port, and the second electrode and the second core wire are further inserted into the second insertion port, the bonding operation is performed. Can be done easily.
[0019]
  Thereafter, in the fifth step, the temperature sensitive element is housed in the metal cover together with the insulating holder, and the metal cover and the sheath pin are fixed. In this way, a temperature sensor is obtained.
  And in the temperature sensor obtained by the manufacturing method of the temperature sensor of 1st, 2nd invention, since an insulation holder consists of a single member, a number of parts reduces. In addition, since this temperature sensor includes a single insulating holder having a first insertion port that opens on one side of the partition portion and a second insertion port that opens on the other side of the partition portion, the first electrode and the first electrode The one core wire, the second electrode, and the second core wire can be separated by a partition part of a single insulating holder, and the joint between the first electrode and the first core wire and the second electrode and the second core wire The joint portion can be reliably arranged in each insertion port. Therefore, the electrode and the core wire are hardly displaced with respect to the insertion opening of the insulating holder, and the first electrode and the first core wire are reliably insulated from the second electrode and the second core wire. Therefore, in the temperature sensor of the first and second inventions, the first and second electrodes and the first and second core wires are reliably insulated from each other, and the cost can be reduced.
[0020]
The joining method in the fourth step is not particularly limited, and examples thereof include laser welding, argon welding, brazing joining, and the like. In order to obtain a good welding strength between the electrode and the core wire, and considering that the electrode and the core wire located in a narrow region such as the insertion opening are joined to each other, laser welding may be employed. preferable.
[0021]
  Also,In the manufacturing method of the first invention,Above2In the process, the inner diameter of the first insertion port (second insertion port) is formed substantially equal to the sum of the outer diameter of the first electrode (second electrode) and the outer diameter of the first core wire (second core wire). One insulating holder is prepared, and the overlapping portion of the first electrode (second electrode) and the first core wire (second core wire) is the opening side of the first insertion port (second insertion port) in the third step. Both are inserted into the first insertion slot (second insertion slot) so as to be exposed toTheBy doing so, in the fourth step, it is possible to maintain the contact state between the electrode and the core wire in the insertion port without performing a pressing work for maintaining contact with the overlapping portion (joint surface) of the core wire, Bonding can be reliably performed on the overlapping portion of the electrode and the core wire, and the bonding operation can be simplified.
[0022]
  Also,In the manufacturing method of the second invention,In the third step, the first electrode (second electrode) and the first core wire (second core wire) are overlapped in the opening direction of the first insertion port (second insertion port) (direction orthogonal to the axial direction of the insulating holder). If the first electrode (second electrode) or the first core wire (second core wire) has a smaller outer diameter, both are positioned on the opening side of the first insertion port (second insertion port). PlaceTheBy doing so, it becomes possible to confirm the arrangement position of the electrode and the core wire well by image processing or the like before joining the overlapping portion of the electrode and the core wire in the fourth step. However, it is possible to perform the dashi accurately, and thus, it is possible to satisfactorily join the overlapping portion between the electrode and the core wire.
[0023]
  1st and 2ndIn the temperature sensor of the invention, it is preferable that the relationship D−d ≦ 0.2 mm is satisfied, where d is the maximum outer diameter of the insulating holder and D is the inner diameter of the metal cover corresponding to the position of the maximum outer diameter. . Thus, since the insulating holder is suitably held in the metal cover, even if vibration is applied to the temperature sensor itself, the insulating holder can be prevented from shaking by the inner peripheral surface of the metal cover. The vibrations of the electrode and the first and second core wires are effectively suppressed, and disconnection of the first and second electrodes and the first and second core wires can be prevented.
[0024]
  1st and 2ndIn the temperature sensor of the invention, the insulating holder may be one in which the first insertion port and the second insertion port are open in the same direction. If the first insertion port and the second insertion port of the insulation holder are open in the same direction, the first electrode, the first core wire, the second electrode, and the second core wire are inserted into the first and second insertion ports of the insulation holder. Then, since the first electrode, the first core wire, the second electrode, and the second core wire can be continuously welded as they are, workability is good. In this case, the cross-sectional shape orthogonal to the axial direction of the insulating holder can be substantially E-shaped. An insulating holder having a substantially E-shaped cross section perpendicular to the axial direction has a simple structure and can be manufactured relatively easily.
[0025]
  Also,1st and 2ndIn the temperature sensor of the invention, the insulating holder may be one in which the first insertion port and the second insertion port are open in the opposite directions. If the first insertion port and the second insertion port of the insulating holder are opened in the opposite directions, the insulation between the first electrode, the first core wire, the second electrode, and the second core wire is particularly good. As such an insulating holder, one having a substantially H-shaped or substantially S-shaped cross-section perpendicular to the axial direction can be adopted.
[0026]
DETAILED DESCRIPTION OF THE INVENTION
  Less than,1st and 2ndEmbodiments 1 to 3 embodying a temperature sensor, a manufacturing method thereof, and an insulating holder for a temperature sensor will be described with reference to the drawings.
[0027]
(Embodiment 1)
FIG. 1 shows a partially broken sectional view of the temperature sensor 100 of the first embodiment. The temperature sensor 100 is provided in the exhaust passage of the vehicle and is used to detect the temperature of the exhaust gas over a wide range. This temperature sensor includes a metal cover 1, a flange 12, a nut 13, an outer cylinder 10 and a grommet 18, a thermistor 2 as a temperature sensitive element, and a sheath pin 3.
[0028]
  As shown in FIG. 2, the bottomed cylindrical metal cover 1 made of metal such as stainless steel is composed of a detail 1a and a large diameter portion 1b. The tip of the detail 1a is closed, and the large diameter portion 1b has an opening. Have. The opening side of the large diameter portion 1b is put on the outer surface of the one end side 3a of the sheath pin 3, and is fixed by all-around laser welding. The detail 1a of the metal cover 1 is provided with a thermistor 2 that detects the temperature and outputs it as an electrical signal to the first electrode 2a and the second electrode 2b (formed from a Pt—Rh alloy wire or the like). The seaspin 3 is a cylindrical sheath made of a metal such as stainless steel.WithinThe first core wire 4 and the second core wire 5 are stored in the two core wires 4, 5 and the sheet.WithInsulating powder such as silica is filled in between. In the metal cover 1, one end side 4 a of the first core wire 4 of the sheath pin 3 is connected to the first electrode 2 a of the thermistor 2 by laser welding, and one end side 5 a of the second core wire 5 of the sheath pin 3 is connected to the second electrode of the thermistor 2. 2b is connected by laser welding. The first and second electrodes 2a and 2b and the one end sides 4a and 5a of the first and second core wires 4 and 5 are alumina inserted between the thermistor 2 and the one end side 3a of the sheath pin 3 in the metal cover 1. It is attached to an insulating holder 6 made of In the temperature sensor 100 of the first embodiment, when the maximum outer diameter of the insulating holder 6 is d and the inner diameter of the metal cover 1 corresponding to the position of the maximum outer diameter is D, D−d = 0.1 It is designed to be (mm) and has a structure in which the vibration of the insulating holder 6 due to vibration can be effectively suppressed by the inner peripheral surface of the metal cover 1.
[0029]
As shown in FIG. 3, the insulating holder 6 is made of insulating ceramics that is a single member having a substantially cylindrical shape, and has a substantially E-shaped cross section perpendicular to the axial direction. The first insertion port 6a and the second insertion port 6b that open in the same direction on the peripheral surface are recessed in parallel to the axial direction, and a partition 6d is formed between the first insertion port 6a and the second insertion port 6b. Has been. The width t2 of the partition 6d is 0.1 mm or more in consideration of mechanical strength and the like.
[0030]
Further, as shown in FIG. 1, the sheath pin 3 is fixed to the flange 12 in a state where the other end side 3 b of the sheath pin 3 is inserted inside the flange 12. The flange 12 includes a sheath portion 12b extending in the axial direction and a projecting portion 12a that is located on one end side of the sheath portion 12b and projects outward in the radial direction. The projecting portion 12a is formed in an annular shape having a seating surface 12c having a tapered shape corresponding to a taper portion of an attachment portion of an exhaust pipe (not shown) on one end side, and the seating surface 12c is in close contact with the taper portion of the attachment portion. Thus, the exhaust gas is prevented from leaking outside the exhaust gas pipe. The sheath pin 3 is press-fitted into the flange 12 and is fixed without gaps by all-around laser welding. Around the flange 12, a nut 13 having a hexagonal nut portion 13a and a screw portion 13b is rotatably fitted. The temperature sensor 1 is fixed by a nut 13 with the seating surface 12c of the projecting portion 12a of the flange 12 in contact with the mounting portion of the exhaust pipe. In addition, one end side 10a of the cylindrical outer cylinder 10 is coaxially joined (for example, all-around laser welding) to the radially outer side of the sheath 12b of the flange 12 in an airtight state. In the outer cylinder 10, the other end sides 4 b and 5 b of the first and second core wires 4 and 5 are caulked by one end sides 14 a and 15 a of the first and second lead wires 14 and 15 and a crimping terminal 16. The other end sides 4b and 5b and the one end sides 14a and 15a are covered with an insulating tube 17 together with crimping terminals 16. A heat-resistant rubber grommet 18 in which first and second lead wire insertion ports 18a and 18b for inserting the first and second lead wires 14 and 15 are formed inside the other end side 10b of the outer cylinder 10. Is arranged and the grommet 18 is fixed to the outer cylinder 10 by caulking the other end side 10b radially inward.
[0031]
A method for manufacturing the temperature sensor 100 will be described. First, the metal cover 1, the thermistor 2, and the sheath pin 3 are prepared in the first step, and the insulating holder 6 is prepared in the second step.
[0032]
In the third step, the first electrode 2a and the first core wire 4 are inserted and overlapped in the first insertion port 6a of the insulating holder 6, and the second electrode 2b and the second core wire 5 are inserted into the second insertion port 6b. Insert and overlay.
[0033]
In the first embodiment, when the outer diameters of the first and second electrodes 2a and 2b and the first and second core wires 4 and 5 are compared, the first and second electrodes 2a and 2b are adjusted to be smaller. Yes. Therefore, when the first electrode 2a and the first core wire 4 are inserted and overlapped in the first insertion opening 6a, the first electrode 2a is inserted so as to be positioned on the opening side of the first insertion opening 6a. By inserting and arranging the first electrode 2a and the first core wire 4 in the first insertion port 6a in this way, the overlapping portion of the first electrode 2a and the first core wire 4 is joined in the fourth step described later. In the previous stage, both positions can be accurately positioned. The same applies to the insertion of the second electrode 2b and the second core wire 5 into the second insertion port 6b.
[0034]
Further, in the insulating holder 6 according to the first embodiment, the width becomes narrower toward the outside on the side where the first and second electrodes 2a and 2b and the first and second core wires 4 and 5 are inserted in the partition 6d. A chamfered portion (C surface which is a chamfered portion in the first embodiment) 6c is formed. By forming the chamfered portion 6c in the partition portion 6d in this way, in the third step, the first and second electrodes 2a and 2b and the first and second core wires 4 and 5 with respect to the first and second insertion ports 6a and 6b are formed. Insertion can be performed smoothly.
[0035]
Further, in the fourth step, the overlapping portion of the first electrode 2a located in the first insertion opening 6a of the insulating holder 6 and the first core wire 4 is joined, and the second electrode 2b located in the second insertion opening 6b. And the overlapping portion of the second core wire 5 are joined.
[0036]
  In the fifth step, the thermistor 2 is housed in the metal cover 1 together with the insulating holder 6, and the one end side 3 a of the sheath pin 3 and the metal cover 1 areLarge diameter partThe overlapping part with 1b is fixed by laser welding all around. Thereafter, the other ends 4b and 5b of the first and second core wires 4 and 5 and the one ends 14a and 15a of the first and second lead wires 14 and 15 are connected by caulking terminals 16 and covered with an insulating tube 17, and then the outer cylinder 10, the flange 12, the nut 13, and the grommet 18 are assembled, and the temperature sensor 100 is completed.
[0037]
In the temperature sensor 100 of the first embodiment configured as described above, the temperature of the exhaust gas is transmitted to the thermistor 2 through the details 1a of the metal cover 1, and the resistance value of the thermistor 2 changes according to the temperature. The resistance of the thermistor 2 is taken out from the first and second lead wires 14 and 15 through the first and second electrodes 2a and 2b and the first and second core wires 4 and 5 as an electric signal. In this way, the temperature of the exhaust gas can be detected by the electrical signal taken out from the first and second lead wires 14 and 15.
[0038]
In this temperature sensor 100, the overlapping portion between the first electrode 2a and the one end side 4a of the first core wire 4 is positioned and laser-welded in the first insertion port 6a of the insulating holder 6, and the second electrode 2b and the second electrode 2b are connected to each other. The one end side 5a of the core wire 5 is positioned in the second insertion port 6b of the insulating holder 6 and laser welded. That is, the insulating holder 6 also serves as a jig for welding the first and second electrodes 2 a and 2 b and the first and second core wires 4 and 5. Therefore, it is not necessary to separately prepare a jig for welding the first and second electrodes 2a and 2b and the first and second core wires 4 and 5. Laser welding is performed with the first electrode 2 a, one end side 4 a of the first core wire 4, the second electrode 2 b, and one end side 5 a of the second core wire 5 inserted into the first and second insertion ports 6 a and 6 b of the insulating holder 6. it can. Therefore, the laser welding operation is easy.
[0039]
Moreover, in this temperature sensor 100, since the insulating holder 6 consists of a single member, the number of parts decreases.
[0040]
Furthermore, in this temperature sensor 100, the one end side 4a of the first electrode 2a and the first core wire 4 and the one end side 5a of the second electrode 2b and the second core wire 5 are separated from each other by the partition portion 6d of the single insulating holder 6. Since no work mistake occurs, the two are reliably insulated from each other.
[0041]
Further, in this temperature sensor 100, one end side 4 a of the first electrode 2 a and the first core wire 4 and one end side 5 a of the second electrode 2 b and the second core wire 5 are held on the metal cover 1 by the insulating holder 6. Therefore, the vibrations of the first and second electrodes 2a and 2b and the first and second core wires 4 and 5 when vibration is applied to the thermistor 2 without fixing the thermistor 2 and the like in the metal cover 1 using cement. Therefore, the manufacturing cost can be reduced and the first and second electrodes 2a and 2b and the first and second core wires 4 and 5 can be prevented from being disconnected.
[0042]
Furthermore, in this temperature sensor 100, since the first insertion port 6a and the second insertion port 6b of the insulating holder 6 are opened in the same direction, the first electrode 2a, the one end side 4a of the first core wire 4 and the second After the electrode 2b and the one end side 5a of the second core wire 5 are inserted into the first and second insertion ports 6a and 6b of the insulating holder 6, the first electrode 2a, the one end side 4a of the first core wire 4 and the second one are left as they are. Since the electrode 2b and the one end side 5a of the second core wire 5 can be continuously laser-welded, workability is good. In particular, since the shape of the cross section perpendicular to the axial direction of the insulating holder 6 is substantially E-shaped, the structure is simple and can be manufactured relatively easily.
[0043]
Therefore, according to the temperature sensor 100, the first electrode 2a and the first core wire 4, the second electrode 2b and the second core wire 5 can be reliably insulated from each other, and the manufacturing cost can be reduced.
[0044]
(Embodiment 2)
The temperature sensor of the second embodiment uses an insulating holder 26 shown in FIG. The insulating holder 26 is made of insulating ceramics that is a single member having an outer shape that is substantially cylindrical, and has a substantially H-shaped cross section orthogonal to the axial direction. The first insertion port 26a and the second insertion port 26b that open in the opposite direction on the peripheral surface are recessed in parallel to the axial direction, and a partition portion 26d is formed between the first insertion port 26a and the second insertion port 26b. Has been. The width t4 of the partition portion 26d is 0.1 mm or more in consideration of mechanical strength.
[0045]
Also in the temperature sensor of the second embodiment, the first electrode 2a and the one end side 4a of the first core wire 4 and the one end of the second electrode 2b and the second core wire 5 are in the first insertion port 26a and the second insertion port 26b. After inserting the side 5a, both are overlapped and laser welding is performed on both overlapping portions to connect the electrodes and the core wire.
[0046]
The inner diameter t3 of the first insertion port 26a and the second insertion port 26b of the insulating holder 26 whose cross-sectional shape is substantially H-shaped is the outer diameter of the first electrode 2a (second electrode 2b) and the first core wire. 4 (second core wire 5) is formed to have a size substantially equal to the total outer diameter. In the second embodiment, although not illustrated, the overlapping portion is exposed to the first insertion port so that the overlapping portion of the first electrode 2a and the first core wire 4 is exposed to the opening side of the first insertion port 26a. 26a. The same applies to the insertion of the second electrode 2b and the second core wire 5 into the second insertion port 26b. Thus, by arranging the first electrode 2a and the first core wire 4, the second electrode 2b and the second core wire 5 in the first and second insertion ports 26a and 26b, the overlapping portion (joint surface) of the electrode and the core wire. Can be maintained in good contact with each other, and laser welding of both can be performed satisfactorily without performing a pressing work for pressing the overlapping portion of the electrode and the core wire. Further, in the insulating holder 26 of the second embodiment, the width becomes narrower toward the outer side toward the side where the first and second electrodes 2a and 2b and the first and second core wires 4 and 5 are inserted in the partition portion 26d. A chamfered portion (R surface which is a chamfered portion in the second embodiment) 26c is formed. Accordingly, the first and second electrodes 2a and 2b and the first and second core wires 4 and 5 can be smoothly inserted into the first and second insertion ports 26a and 26b.
[0047]
In this temperature sensor, the insulation between the first electrode 2 a, the first core wire 4, the second electrode 2 b, and the second core wire 5 is particularly improved by the insulating holder 26.
[0048]
(Embodiment 3)
The temperature sensor of the third embodiment uses an insulating holder 36 shown in FIG. The insulating holder 36 is also made of insulating ceramics, which is a single member having a substantially cylindrical shape, and has a substantially S-shaped cross section perpendicular to the axial direction. The first insertion port 36a and the second insertion port 36b that open in the opposite direction to the peripheral surface are recessed in parallel to the axial direction, and a partition 32d is formed between the first insertion port 36a and the second insertion port 36b. Has been. The width t6 of the partition part 36d is 0.1 mm or more in consideration of mechanical strength and the like.
[0049]
Also in this temperature sensor, the insulation between the first electrode 2a, the first core wire 4, the second electrode 2b, and the second core wire 5 is particularly improved by the insulating holder 36.
[0050]
The present invention is not limited to the specific embodiments described above, and various modifications can be made within the scope of the present invention depending on the purpose and application. For example, the insulating holders 6, 26, and 36 may be formed of a single member, and the shape is not limited to a substantially cylindrical shape.
[0051]
Furthermore, the joining of the overlapping portion between the first electrode 2a and the one end side 4a of the first core wire 4 and the joining of the overlapping portion between the second electrode 2b and the one end side 5a of the second core wire 5 are as in the first to third embodiments. However, it is not limited to laser welding, and may be performed by argon welding, brazing welding, or the like. Further, the shape of the metal cover 1 may be a substantially straight cylindrical shape instead of the stepped shape as in the first embodiment.
[Brief description of the drawings]
FIG. 1 is a partially broken cross-sectional view of a temperature sensor according to a temperature sensor, a manufacturing method thereof, and a temperature sensor insulating holder according to a first embodiment.
FIG. 2 is a partially enlarged cross-sectional view of the temperature sensor according to the temperature sensor, the manufacturing method thereof, and the temperature sensor insulating holder according to the first embodiment.
FIG. 3 is a perspective view of an insulating holder according to the temperature sensor, the manufacturing method thereof, and the insulating holder for the temperature sensor according to the first embodiment.
4 is a perspective view of an insulating holder according to a temperature sensor, a manufacturing method thereof, and an insulating holder for a temperature sensor according to Embodiment 2. FIG.
FIG. 5 is a perspective view of an insulating holder according to a temperature sensor, a manufacturing method thereof, and an insulating holder for a temperature sensor according to a third embodiment.
[Explanation of symbols]
1 ... Metal cover
2 ... Temperature sensing element (thermistor)
2a ... 1st electrode
2b ... second electrode
3 ... Seaspin
4 ... 1st core wire
5 ... Second core wire
6, 26, 36 ... Insulation holder
6a, 26a, 36a ... 1st insertion slot
6b, 26b, 36b ... 2nd insertion slot
6d, 26d, 36d ... partitioning part

Claims

先端が閉じられた有底筒状の金属カバーと、温度を検知して電気信号として第１電極及び第２電極に出力可能な感温素子と、内部に絶縁状態で第１芯線及び第２芯線が設けられたシースピンとを少なくとも用意する第１工程と、
両側を絶縁状態に離反させる仕切部と、該仕切部の一方側に開く第１挿入口と、該仕切部の他方側に開く第２挿入口とを有する単一の絶縁ホルダであって、該第１挿入口の内径が該第１電極の外径と該第１芯線の外径との合計と略同等に形成されるとともに、該第２挿入口の内径が該第２電極の外径と該第２芯線の外径との合計と略同等に形成されてなる絶縁ホルダを用意する第２工程と、
該絶縁ホルダの該第１挿入口内に、該第１電極と該第１芯線との重なり部が該第１挿入口の開口側に露出するように、該第１電極と該第１芯線とを挿入して重ね合わせる一方、該第２挿入口内に、該第２電極と該第２芯線との重なり部が該第２挿入口の開口側に露出するように、該第２電極と該第２芯線とを挿入して重ね合わせる第３工程と、
該絶縁ホルダの該第１挿入口内に位置する該第１電極と該第１芯線との前記重なり部を接合し、該第２挿入口内に位置する該第２電極と該第２芯線との前記重なり部を接合する第４工程と、
該絶縁ホルダとともに該感温素子を該金属カバー内に収納し、該金属カバーと該シースピンとを固定する第５工程とを備えていることを特徴とする温度センサの製造方法。A bottomed cylindrical metal cover with a closed tip, a temperature sensing element capable of detecting the temperature and outputting it as an electrical signal to the first electrode and the second electrode, and the first and second core wires in an insulated state inside A first step of preparing at least a seaspin provided with:
A single insulating holder having a partition part that separates both sides in an insulated state, a first insertion port that opens on one side of the partition part, and a second insertion port that opens on the other side of the partition part , The inner diameter of the first insertion port is formed substantially equal to the sum of the outer diameter of the first electrode and the outer diameter of the first core wire, and the inner diameter of the second insertion port is equal to the outer diameter of the second electrode. A second step of preparing an insulating holder formed substantially equal to the total outer diameter of the second core wire ;
The first electrode and the first core wire are placed in the first insertion port of the insulating holder so that the overlapping portion of the first electrode and the first core wire is exposed to the opening side of the first insertion port . while that overlay inserted, to the second insertion mouth, as the overlapping portion between the second electrode and the second wire is exposed to the opening side of the second insertion opening, said second electrode and said A third step of inserting and superposing two core wires;
Joining the overlapping portion between the first electrode and the first core positioned in the first insertion mouth of the insulating holder, the the second electrode and the second core is located in the second insertion mouth A fourth step of joining the overlapping portions;
A temperature sensor manufacturing method comprising: a fifth step of housing the temperature sensitive element in the metal cover together with the insulating holder and fixing the metal cover and the sheath pin.

先端が閉じられた有底筒状の金属カバーと、温度を検知して電気信号として第１電極及び第２電極に出力可能な感温素子と、内部に絶縁状態で第１芯線及び第２芯線が設けられたシースピンとを少なくとも用意する第１工程と、
両側を絶縁状態に離反させる仕切部と、該仕切部の一方側に開く第１挿入口と、該仕切部の他方側に開く第２挿入口とを有する単一の絶縁ホルダを用意する第２工程と、
該絶縁ホルダの該第１挿入口内に、該第１電極又は該第１芯線の外径の小さいほうが該第１挿入口の開口側に位置するように、該第１電極と該第１芯線とを挿入して重ね合わせる一方、該第２挿入口内に、該第２電極又は該第２芯線の外径の小さいほうが該第２挿入口の開口側に位置するように、該第２電極と該第２芯線とを挿入して重ね合わせる第３工程と、
該絶縁ホルダの該第１挿入口内に位置する該第１電極と該第１芯線との重なり部を接合し、該第２挿入口内に位置する該第２電極と該第２芯線との重なり部を接合する第４工程と、
該絶縁ホルダとともに該感温素子を該金属カバー内に収納し、該金属カバーと該シースピンとを固定する第５工程とを備えていることを特徴とする温度センサの製造方法。A bottomed cylindrical metal cover with a closed tip, a temperature sensing element capable of detecting the temperature and outputting it as an electrical signal to the first electrode and the second electrode, and the first and second core wires in an insulated state inside A first step of preparing at least a seaspin provided with:
Preparing a single insulating holder having a partition part that separates both sides in an insulated state, a first insertion port that opens on one side of the partition part, and a second insertion port that opens on the other side of the partition part; Process,
In the first insertion port of the insulating holder, the first electrode and the first core wire are arranged so that the smaller outer diameter of the first electrode or the first core wire is located on the opening side of the first insertion port . while that overlay by inserting, in the second insertion mouth, as the smaller outer diameter of the second electrode or the second core is located on the opening side of the second insertion opening, and the second electrode A third step of inserting and overlapping the second core wire;
The overlapping portion between the first electrode located in the first insertion port of the insulating holder and the first core wire is joined, and the overlapping portion between the second electrode located in the second insertion port and the second core wire A fourth step of bonding
A temperature sensor manufacturing method comprising: a fifth step of housing the temperature sensitive element in the metal cover together with the insulating holder and fixing the metal cover and the sheath pin.

前記絶縁ホルダの最大外径をｄ、該絶縁ホルダの最大外径の位置に対応する前記金属カバーの内径をＤとしたときに、Ｄ−ｄ≦０．２ｍｍの関係を満たすことを特徴とする請求項１又は２記載の温度センサの製造方法。When the maximum outer diameter of the insulating holder is d and the inner diameter of the metal cover corresponding to the position of the maximum outer diameter of the insulating holder is D, the relationship of D−d ≦ 0.2 mm is satisfied. The manufacturing method of the temperature sensor of Claim 1 or 2 .

前記絶縁ホルダは、前記第１挿入口及び前記第２挿入口が同一方向に向かって開いていることを特徴とする請求項１乃至３のいずれか１項記載の温度センサの製造方法。The insulating holder, the manufacturing method of the temperature sensor of any one of claims 1 to 3 first insertion opening and the second insertion opening, characterized in that the open towards the same direction.

前記絶縁ホルダは、軸方向に直交する断面形状が略Ｅ字型であることを特徴とする請求項４記載の温度センサの製造方法。The method of manufacturing a temperature sensor according to claim 4 , wherein the insulating holder has a substantially E-shaped cross section perpendicular to the axial direction.

前記絶縁ホルダは、前記第１挿入口及び前記第２挿入口が逆方向に向かって開いていることを特徴とする請求項１乃至３のいずれか１項記載の温度センサの製造方法。The temperature sensor manufacturing method according to any one of claims 1 to 3 , wherein the insulating holder has the first insertion port and the second insertion port opened in opposite directions.

前記絶縁ホルダは、軸方向に直交する断面形状が略Ｈ字型であることを特徴とする請求項６記載の温度センサの製造方法。The method for manufacturing a temperature sensor according to claim 6 , wherein the insulating holder has a substantially H-shaped cross-section perpendicular to the axial direction.

前記絶縁ホルダは、軸方向に直交する断面形状が略Ｓ字型であることを特徴とする請求項６記載の温度センサの製造方法。The method for manufacturing a temperature sensor according to claim 6 , wherein the insulating holder has a substantially S-shaped cross section perpendicular to the axial direction.