JP3668297B2

JP3668297B2 - End of the endoscope

Info

Publication number: JP3668297B2
Application number: JP24494395A
Authority: JP
Inventors: 誠二北野; 次生岡▲崎▼; 武司横井
Original assignee: Olympus Corp
Current assignee: Olympus Corp
Priority date: 1995-09-22
Filing date: 1995-09-22
Publication date: 2005-07-06
Anticipated expiration: 2015-09-22
Also published as: JPH0984742A

Description

【０００１】
【発明の属する技術分野】
本発明は、観察光学系等を備えた挿入部を有する内視鏡の先端部に関し、特に内視鏡の挿入部先端部における先端部本体と絶縁カバーの接合構造の改良に関する。
【０００２】
【従来の技術】
観察光学系等を備えた細長の挿入部を有する内視鏡は、医療分野、工業分野等で広く用いられている。内視鏡の挿入部先端部は、一般的には金属等の硬性部材で形成された先端部本体に絶縁部材からなるカバーを被覆して、被検体の感電などを防止し電気安全性を向上させた構成となっている。
【０００３】
従来は、実公平６−２８０８１号公報のように、金属製の先端部本体の先端面を凹状に形成するとともに、電気絶縁性の部材で形成した絶縁カバーの後端面を凸状に形成して、その凸状部を上記先端部本体の凹部に嵌合させて接着剤により固定していた。また、先端部本体と絶縁カバーとを貫通する貫通孔を穿設して、その貫通孔内に内蔵物の先端を取着していた。この各内蔵物の先端を取着する複数の貫通孔間は、絶縁カバーの後端面と金属製の先端部本体の前面とを平面同士で突き当てて接着していた。
【０００４】
【発明が解決しようとする課題】
しかしながら、前記従来例のように貫通孔部分において絶縁カバーと先端部本体とを平面同士で突き当てて接着する構成では、接着剤を塗布しすぎると組立時に接着剤が貫通孔へしみ出して貫通孔を狭めたり埋めてしまう不具合が生じる。逆に、接着剤の塗布量が少ないと各貫通孔間の水密が保たれなくなるおそれがある。水密が保持できないと、洗滌時に各貫通孔間のすきまから内視鏡内部に水が侵入してしまい、故障の原因となってしまうという不具合が生じる。
【０００５】
本発明は、これらの事情に鑑みてなされたもので、先端部本体の先端側に絶縁カバーを被覆して挿入部先端部を構成したものにおいて、貫通孔内に接着剤がしみ出すことを防止すると共に、絶縁カバーと先端部本体との接着強度及び水密性を保持でき、組立性及び内蔵物の絶縁カバーへの固定強度を向上させることが可能な内視鏡の先端部を提供することを目的としている。
【０００６】
【課題を解決するための手段】
本発明による内視鏡の先端部は、挿入部先端を構成する先端部本体と、この先端部本体の外表面が露出しないよう該先端部本体の先端側を覆う絶縁カバーとを有し、前記先端部本体と絶縁カバーとを貫通する貫通孔を穿設した内視鏡の先端部において、前記絶縁カバーに形成される貫通孔の開口部の周囲に設けられる凸状部と、前記先端部本体の貫通孔の開口部の周囲に設けられ、前記凸状部に嵌合する凹状部と、前記凸状部と凹状部との嵌合面に設けられ、前記絶縁カバーと先端部本体とを固定するために接着剤を塗布する接着面とを有することを特徴とし、前記絶縁カバーの貫通孔の周囲に形成される凸状部は、貫通孔が形成されていない部位よりも挿入部軸方向における手元側に突出していることを特徴とする。
また、本発明による内視鏡の先端部は、挿入部先端を構成する先端部本体と、この先端部本体の外表面が露出しないよう該先端部本体の先端側を覆う絶縁カバーとを有し、前記先端部本体と絶縁カバーとを貫通する貫通孔を穿設した内視鏡の先端部において、前記絶縁カバーの一部に形成され、挿入部軸方向における手元側に突出する第１の突出部と、前記先端部本体に形成され、この第１の突出部が係合する第１の係合部と、前記絶縁カバーに形成される貫通孔の開口部周辺に形成され、前記第１の突出部よりも挿入部軸方向における手元側に突出する第２の突出部と、前記先端部本体に形成され、この第２の突出部に係合する第２の係合部と、前記第２の突出部と第２の係合部との嵌合面に設けられ、前記絶縁カバーと先端部本体とを固定するために接着剤を塗布する接着面とを有することを特徴とする。
また、本発明による絶縁カバーの固定方法は、挿入部先端を構成する先端部本体に対し、この先端部本体の外表面が露出しないよう該先端部本体の先端側を覆う絶縁カバーを固定する絶縁カバーの固定方法であって、前記絶縁カバーに設けられた貫通孔の開口部の周囲に形成された凸状部と前記先端部本体に設けられた貫通孔の開口部の周囲に形成された凹状部との嵌合面に接着剤を塗布して前記絶縁カバーと先端部本体とを固定することを特徴とする。
【０００７】
【発明の実施の形態】
以下、図面を参照して本発明の実施の形態を説明する。
図１ないし図８は本発明の第１の実施形態に係り、図１は内視鏡システムの全体構成を示す構成説明図、図２及び図３は内視鏡の挿入部先端部の構成を示す軸方向断面図（図２は図４において断面Ｆ−Ｏ2 −Ｏ1 −Ｏ3 −Ｆ′で切った図、図３は図４において断面Ｇ−Ｏ−Ｇ′で切った図）、図４は挿入部先端部の先端面における配置構成を示す平面図（図２においてＡ方向から見た矢視図）、図５は図２，図３において断面Ｃ−Ｃ，断面Ｅ−Ｅで切った横断面図、図６は図２において断面Ｄ−Ｄで切った横断面図、図７は図２において断面Ｂ−Ｂで切った横断面図、図８は図５における係止ピンの変形例を示す横断面図である。
【０００８】
図１に示す内視鏡システム１は、内視鏡２を有しており、この内視鏡２は細長く可撓性を有する挿入部３と、この挿入部３の手元側に連結された操作部４とを備えて構成されている。
【０００９】
挿入部３の先端側には、硬性の先端部５が設けられ、この先端部５に隣接して後端側に湾曲可能な湾曲部６が設けられている。
【００１０】
操作部４の挿入部３側の側部には、内視鏡内部に配設された図示しない挿通チャンネルに連通する挿入口７が設けられている。操作部４の基端側の側部には、回動させることによって湾曲部６を湾曲操作する湾曲操作ノブ８が設けられている。さらに操作部４の湾曲操作ノブ８の裏側から後方に可撓性を有するユニバーサルコード９が延出しており、このユニバーサルコード９の端部にはコネクタ１０が設けられている。
【００１１】
内視鏡１は、前記コネクタ１０及びユニバーサルコード９を介して、観察用の照明光源を備えた光源装置と映像信号処理回路とが内蔵された制御装置１１に接続されるようになっている。前記制御装置１１には、表示手段としてカラーＣＲＴのモニタ１２が映像信号ケーブル１３によって接続されている。
【００１２】
図２ないし図７に示すように、前記先端部５を構成する先端部本体１４には、後述する各種の内蔵物、例えば観察光学系、照明光伝達系、及び送気または送水の少なくとも一方がなされる管路等が組み込まれている。
【００１３】
一方、前記湾曲部６は、金属材からなる複数の湾曲用駒１５を互いにリベット１７で回動自在に連結して構成され、湾曲用駒１５の外周には電気絶縁性の合成樹脂からなる外皮１８が被覆されている。外皮１８の端部は、固定糸４７によって縛り固定されている。
【００１４】
前記先端部本体１４の先端面及び先端側外周面には、ポリサルフォン等の合成樹脂やセラミック等の電気絶縁性の材料からなる絶縁カバー１９が被嵌されている。これらの先端部本体１４及び絶縁カバー１９には、挿入部軸方向に対物観察ユニット２０が着脱自在に取り付けられている。
【００１５】
図２及び図３に示すように、前記対物観察ユニット２０は、その先端に対物第一レンズ２０ａ，対物第二レンズ２０ｂが配置されている。そして、前記対物第一レンズ２０ａ及び対物第二レンズ２０ｂを保持する対物レンズ内枠５０が設けられ、この対物レンズ内枠５０の操作部側外周部に対物レンズ外枠３９が配設されている。
【００１６】
この対物レンズ外枠３９は、その外周溝３９ａにＯリング４０が取り付けられ、さらに先端部本体１４に貫通した対物レンズ枠取付孔１４ｇに嵌合するようになっている。また、対物レンズ外枠３９の外周中途に設けられたＶ字溝３９ｂには、その２つの斜面のうちの先端部側に配置された斜面３９ｃに、対物観察ユニット固定ネジ４１の円錐部先端４１ａが当接するようになっている。
【００１７】
対物観察ユニット固定ネジ４１は、図５に示すように、先端部本体１４の外周から対物レンズ枠取付孔１４ｇに貫通して設けられたネジ孔１４ｈに螺合し、先端部本体１４に対して対物観察ユニット２０を固定するようになっている。
【００１８】
このとき、対物レンズ外枠３９を対物レンズ枠取付孔１４ｇに挿入後、外周部に組み付いたＯリング４０がネジ孔１４ｈと干渉しないように、対物レンズ枠取付孔１４ｇ壁面のうちＯリング４０との摺動部分には、ネジ孔１４ｈ部分を越えて先端部までＵ字溝１４ｉが設けられ、このＵ字溝１４ｉによりＯリング４０とネジ孔１４ｈとの干渉を防止している。
【００１９】
図２及び図３に示すように、絶縁カバー１９はほぼキャップ状に形成されており、先端部本体の先端側端面１４ａと絶縁カバーの操作部側端面１９ａとが当接するようになっている。
【００２０】
絶縁カバー１９には、挿入部軸方向にノズル用貫通孔１９ｄが穿設されており、このノズル用貫通孔１９ｄには、対物観察ユニット２０の対物第一レンズ２０ａ表面を洗滌する対物レンズ洗滌ノズル２１が嵌合し、図７（図２のＢ−Ｂ断面）に示すように挿入部径方向に嵌入された係止ピン２２によって絶縁カバー１９内に係止している。
【００２１】
前記係止ピン２２が挿通する係止ピン取付孔１９ｈは、絶縁カバー１９に設けたノズル用貫通孔１９ｄに連通し、このノズル用貫通孔１９ｄから絶縁カバー１９の外周に向かって径方向に貫通している。係止ピン２２は、係止ピン取付孔１９ｈに嵌合し、この嵌合部にシリコン系で剥離しやすい接着剤を塗付することにより、絶縁カバー１９に固定されている。係止ピン２２の外表面端部２２ｂは、組み付け時に絶縁カバー１９の外周面と一致させるため、円弧状の曲面に形成されている。
【００２２】
また、係止ピン２２の他端には、対物レンズ洗滌ノズル２１の側周部に設けられた係合凹部２１ｂに係合する円弧状の端面を有する先端部２２ａが形成されている。この先端部２２ａは、対物レンズ洗滌ノズル２１の着脱方向（挿入部先端方向）に対し、直角方向で対物レンズ洗滌ノズル２１の係合凹部２１ｂと係合し、対物レンズ洗滌ノズル２１を係止するようになっている。
【００２３】
なお、係止ピン２２は、図８に示すような変形例とすることもできる。つまり、係止ピン２２の一部に細径部２２ｃを設け、この細径部２２ｃ以外の部分のみに接着剤を塗布することにより、接着剤の塗布量を規制することができ、係止ピン２２の抜去性を向上させることも可能である。
【００２４】
前記ノズル用貫通孔１９ｄは、先端部本体１４の送気送水管路１４ｅに連通しており、この送気送水管路１４ｅの後端には送気送水パイプ２４が取り付けられている。送気送水パイプ２４の後端部には、送気送水チューブ２５が連結されている。
【００２５】
前記先端部本体１４と絶縁カバー１９は、図５に示すように、両者にそれぞれ固定孔１４ｊ，１９ｊが設けられ、そこに接着剤を充填することにより先端部本体１４と絶縁カバー１９を固定する構造となっている。
【００２６】
また、前記絶縁カバー１９及び先端部本体１４には、照明光伝達系を構成する照明レンズユニット３３が配置され、この照明レンズユニット３３の手元側に光学繊維束からなるライトガイド３４が連設されている。ライトガイド３４は、ライトガイド保護チューブ４８を外装することにより、他の内蔵物によるライトガイドの折れを防止している。このライトガイド保護チューブ４８の先端は固定糸４９により縛り固定されている。
【００２７】
前記ライトガイド３４の先端は、ライトガイド枠４４が装着され、先端部本体１４を軸方向に貫通する照明系取付孔１４ｄに後方より挿入され、図６に示すように先端部本体１４内で固定ネジ４２によって固定されている。一方、前記照明レンズユニット３３は、照明系取付孔１４ｄに接着剤で固定されている。
【００２８】
また、絶縁カバー１９には照明系取付孔１４ｄと対向する位置に照明系貫通孔１９ｆが設けられており、この照明系貫通孔１９ｆには照明レンズ３３ａを先端内部に配置した照明レンズユニット３３の先端が接着固定されている。照明レンズユニット３３の先端近傍外周には外枠フランジ部３５が設けられており、この外枠フランジ部３５が先端部本体１４の先端面に当接することにより、照明レンズユニット３３の軸方向の位置が決められるようになっている。
【００２９】
本実施形態では、図２に示すように、対物レンズ洗滌ノズル２１を取り付けるノズル用貫通孔１９ｄの開口部の周囲において第一凸部１９ｂが形成されている。これに対応して、先端部本体１４には、送気送水管路１４ｅの先端側周辺に第一凸部１９ｂが嵌合する第一凹部１４ｂが設けられている。また、照明光伝達系取付用の照明系貫通孔１９ｆの開口部の周囲において第一凸部１９ｂよりも挿入部軸方向後方に突出した第二凸部１９ｃが形成されている。これに対応して、先端部本体１４には、照明系取付孔１４ｄの先端側周辺に第二凸部１９ｃが嵌合する第二凹部１４ｃが設けられている。
【００３０】
また、図３に示すように、絶縁カバー１９及び先端部本体１４には、処置具チャンネルの先端を構成する処置具挿通パイプ３６が取り付けられている。処置具挿通パイプ３６は、絶縁カバー１９を挿入部軸方向に貫通した処置具挿通パイプ貫通孔１９ｇと、前記処置具挿通パイプ貫通孔１９ｇに対向する位置で先端部本体１４を軸方向に貫通した処置具挿通パイプ取付孔１４ｆとに嵌合し固定されている。
【００３１】
処置具挿通パイプ３６は、先端部本体１４の後端面から操作部側に延出し、この処置具挿通パイプ３６の操作部側には、チャンネルチューブ３７が連結している。チャンネルチューブ３７の先端は、固定糸３８でチャンネルチューブ３７の外周を糸巻きにより縛って接着面を密着させることにより、処置具挿通パイプ３６に固定されている。またチャンネルチューブ３７は、外周に螺旋状の溝３７ａを設けることにより、曲がり性を向上させて湾曲操作の力量を軽くすると共に、さらにこの溝３７ａにコイル４５を巻きつけることにより、曲げ応力に対してある程度の強度を持たせてチャンネルチューブ３７の座屈を防止している。
【００３２】
次に、前述のように構成された内視鏡２の先端部５の組立手順を以下に説明する。
【００３３】
まず、送気送水パイプ２４と処置具挿通パイプ３６を先端部本体１４に位置決めして半田付けにより固定する。
【００３４】
次に、照明レンズユニット３３の外周に接着剤を塗布し、先端部本体１４に照明レンズユニット３３の外枠フランジ部３５が当接するまで挿入する。さらに、絶縁カバー１９と先端部本体１４の当接面に接着剤を塗布し、両者を接合し硬化させる。また、ライトガイド３４にライトガイド保護チューブ４８を外装し、固定糸４９により固定する。
【００３５】
そして、図２及び図３に示す処置具挿通パイプ３６と絶縁カバー１９に設けた処置具挿通パイプ貫通孔１９ｇとの隙間、照明レンズユニット３３と絶縁カバー１９との隙間、送気送水パイプ２４と絶縁カバー１９との隙間、の合計３カ所に接着剤を前述の構成になるように気密的に充填し硬化させる。
【００３６】
さらに、処置具挿通パイプ３６の一端に接着剤を塗布してチャンネルチューブ３７を嵌合させ、固定糸３８でチャンネルチューブ３７の接着部のほぼ全域の外周を糸巻き固定する。このようにして処置具挿通パイプ３６の後端にチャンネルチューブ３７を密着させ硬化させる。また、チャンネルチューブ３７の溝３７ａに沿ってコイル４５を外装する。
【００３７】
次いで、図２及び図３に示す対物観察ユニット２０のレンズ枠段部５０ａに接着剤を塗布し、先端部本体１４の対物レンズ枠取付孔１４ｇ段部に当接するまで挿入し、対物観察ユニット固定ネジ４１で固定する。そして、対物観察ユニット２０が絶縁カバー１９に嵌合したときに形成される隙間に、接着剤を気密的に充填する。
【００３８】
また、対物レンズ洗滌ノズル２１の外周に接着剤を塗布し、絶縁カバー１９の当接面１９ｋまで挿入する。さらに対物レンズ洗滌ノズル２１の開口部２１ａが対物第一レンズ２０ａの方向に開口するように位置決めして、送気または送水の射出方向を調整する。
【００３９】
さらに、図７に示す絶縁カバー１９に設けた係止ピン取付孔１９ｈに接着剤を塗布し、この係止ピン取付孔１９ｈに係止ピン２２を挿入し、係止ピン２２の先端部２２ａを例えば対物レンズ洗滌ノズル２１の係合凹部２１ｂに当接させ、前記接着剤を硬化させる。これによって対物レンズ洗滌ノズル２１は、係止ピン２２が破壊または抜去されるまで絶縁カバー１９から抜けないようになる。
【００４０】
このとき、第一凸部１９ｂが第一凹部１４ｂに嵌合するが、その際に第一凸部１９ｂは絶縁カバー１９の装着においてガイドの役割をはたし、絶縁カバー１９と先端部本体１４の各貫通孔、例えばノズル用貫通孔１９ｄと送気送水管路１４ｅ、対物レンズ枠挿通孔１９ｉと対物レンズ枠取付孔１４ｇ等の位置決めを行うことができる。これにより、絶縁カバー１９装着時の組立性が向上する。
【００４１】
絶縁カバー１９を先端部本体１４に組み付ける際には、接着剤を絶縁カバー１９と先端部本体１４が嵌合及び当接する部分、例えば操作部側端面１９ａ、第一凸部１９ｂ、第二凸部１９ｃに塗布する。
【００４２】
ここで、前記接着剤を塗布する手順として、第二凸部１９ｃ周辺に関する接着剤の塗布を例にとり説明する。接着剤を絶縁カバー１９の嵌合面に塗布し、先端部本体１４の第二凹部１４ｃに挿入する。この際、接着剤は第二凸部１４ｃの端面に一部しみ出すが、照明レンズユニット３３取付用の照明系貫通孔１９ｆや照明系取付孔１４ｄの内部へしみ出して貫通孔を埋めてしまうことはない。
【００４３】
最後に、先端部本体１４と絶縁カバー１９の側部にそれぞれ設けた固定孔１４ｊ，１９ｊに接着剤を充填し、両者の固定を行う。
【００４４】
以上説明したように、本実施形態では、第一凸部１９ｂ，第一凹部１４ｂ及び第二凸部１９ｃ，第二凹部１４ｃを設けることにより、先端カバー１９と先端部本体１４とを組み付ける際の組立作業性を向上させることができる。
【００４５】
また前記構成により、照明レンズユニット３３と絶縁カバー１９の嵌合長が長くなり接着面積が増加するので、照明レンズユニット３３と絶縁カバー１９の固定強度を増加させることができる。また、絶縁カバー１９と先端部本体１４との嵌合長が長くなり接着面が増加するので、絶縁カバー１９と先端部本体１４との固定強度を増加させることができ、さらに水密性も向上させることが可能となる。
【００４６】
また、第二凸部１９ｃの嵌合面にのみ接着剤を塗布することにより、照明レンズユニット３３取付用の照明系貫通孔１９ｆ及び照明系取付孔１４ｄなど、内蔵物を取り付ける貫通孔内に接着剤がしみ出すことを防止でき、挿入部先端部を組立てる際の不具合をなくすことができる。
【００４７】
以下の第２及び第３の実施形態において、前述した第１の実施形態における絶縁カバーと先端部本体とを嵌合させる凹凸部の構成を変更した例を示す。
【００４８】
図９ないし図１４は本発明の第２の実施形態に係り、図９は内視鏡の挿入部先端部の構成を示す軸方向断面図（図２と同一箇所の断面図）、図１０は図９において断面Ｈ−Ｈで切った横断面図、図１１は送気送水管路内を掃除する掃除用ブラシの外観構成を示す側面図、図１２は送気送水パイプの変形例を示す軸方向断面図、図１３は図１２の送気送水パイプをＩ方向から見た矢視図、図１４は送気送水管路分岐部の構成を示す軸方向断面図である。
【００４９】
図９及び図１０に示すように、第２の実施形態の絶縁カバー６９は、図２に示した第１の実施形態と同様に、第一凸部６９ｂが形成されると共に、この第一凸部６９ｂからさらにノズル用貫通孔６９ｄの開口部の周囲において挿入部軸方向後方に突出した第二凸部６９ｃが設けられている。すなわち、対物レンズ洗滌ノズル２１を係止するための係止ピン２２が嵌入する係止ピン取付孔６９ｈを設けることにより肉厚になっている第一凸部６９ｂから、さらに操作部側に突出している第二凸部６９ｃが設けられ、二段状の凸部が形成されている。
【００５０】
前記第一凸部６９ｂ及び第二凸部６９ｃに対応して、先端部本体６４側には、第一凸部６９ｂが嵌合する第一凹部６４ｂと、第二凸部６９ｃが嵌合する第二凹部６４ｃとが設けられている。
【００５１】
その他の部分の構成は第１の実施形態とほぼ同様であり、説明を省略する。
【００５２】
本実施形態では、絶縁カバー６９を先端部本体６４に組み付けた際に、第二凸部６９ｃと第二凹部６４ｃが嵌合する形となるので、送気送水管路６４ｅとノズル用貫通孔６９ｄは段差なく連通し、管路内の洗滌の際に掃除用ブラシが引っかかることなく、また汚物も溜まりにくい構造となっている。
【００５３】
送気送水管路６４ｅ等の管路内を洗滌する際には、図１１に示すような掃除用ブラシ２３を用いる。本実施形態では掃除用ブラシ２３の挿通性を向上させるために、先端部本体６４には斜めに送気送水管路６４ｅが設けてあるので、対物レンズ洗滌ノズル２１の中心軸ｄ1 と先端部本体６４の先端側端面６４ａでの管路中心ｄ2 とをずらして配置している。この結果、掃除用ブラシ２３を斜め孔からストレート孔へスムーズに挿通でき、中心をずらさない場合よりも挿通性が向上する。
【００５４】
また、送気送水管路６４ｅは、先端部本体６４に斜めに設けられているため、先端側端面６４ａにおいて断面形状が楕円になる。よって、絶縁カバー６９のノズル用貫通孔６９ｄと送気送水管路６４ｅとをつなぐ管路中継部６９ｅは、ノズル用貫通孔６９ｄ側が丸円状で送気送水管路６４ｅ側が楕円状の断面形状となっている。
【００５５】
ここで、管路中継部６９ｅの孔の開口端を送気送水管路６４ｅの先端側端面６４ａにおける断面形状と同形状の楕円とすることにより、段差が生じることがないので、掃除用ブラシ２３の引っかかりがなく、洗滌性が向上する。なお、管路中継部６９ｅと送気送水管路６４ｅとの段差がわずかである場合は、管路中継部６９ｅの開口端の断面形状を真円としても良い。
【００５６】
さらに、絶縁カバー６９の管路中継部６９ｅは、洗滌性向上のため、孔が丸断面から送気送水管路６４ｅに向かって楕円断面へと断面形状が変化する部分においても段差を設けず、滑らかにつないで形成している。
【００５７】
また、送気送水管路６４ｅの後端に連結される送気送水パイプ２４の曲げ角度θは、掃除用ブラシ２３の挿通性を考慮して１５°以下としている。
【００５８】
なお、送気送水パイプ２４は、掃除用ブラシ２３の挿通性をよくするため、図１２及び図１３に示すような形状とすることも可能である。この変形例では、送気送水パイプ２４ａを送気送水管路１４ｅの先端まで貫通した構造となっており、送気送水パイプ２４ａの内径の一部に拡大穴２８を設けている。これにより、掃除用ブラシ２３をスムーズに挿通することが可能となる。
【００５９】
また、先端部本体１４と送気送水パイプ２４ａの接着面積を増加し接着強度を増加するために、送気送水パイプ２４ａの外径の一部を加工して平坦部２９を設けている。
【００６０】
前記送気送水パイプ２４ａの一端は、先端部本体１４に半田付けにより固定され、他端には挿入部内を挿通する送気送水チューブ２５の一端が連結している。この送気送水チューブ２５は、先端近傍の外周を固定糸２６によって縛ることにより、送気送水パイプ２４ａに固定されている。このチューブ固定部には、送気送水パイプ２４ａの後端側と送気送水チューブ２５との接着面を密着させるため、熱収縮チューブ２７が密着されている。さらに、送気送水チューブ２５が他の内蔵物により傷つけられるのを防止するため、保護チューブ４３が外装されている。
【００６１】
送気送水チューブ２５の手元側の端部は、図１４に示すような送気送水管路分岐３０に連結されている。送気送水管路分岐３０の送気パイプ３０ａには送気チューブ３１の一端が、送水パイプ３０ｂには送水チューブ３２の一端が連結している。そして、送気チューブ３１，送水チューブ３２の他端は、操作部４に設けられた図示しない管路切り換え装置に連結している。また、作業性を良くするために、送気チューブ３１，送水チューブ３２の端部近傍には若干細径にしたしぼり部３１ａ，３２ａが設けられている。
【００６２】
前記送気パイプ３０ａと送水パイプ３０ｂは、半田付け部５３により両者は接続固定されている。組立時には、送気送水管路分岐３０に各チューブを連結した後、強度向上のため接着剤を塗布して接着剤層５４を形成する。
【００６３】
このような送気送水管路においては、洗滌を繰り返すと掃除用ブラシ２３によりチューブ内径が削られ、チューブ肉厚が薄くなってチューブの座屈を起こし易くなる問題点がある。そこで、図１４に示すように、掃除用ブラシ２３を通す送気チューブ３１の肉厚ｔ1 を送水チューブ３２の肉厚ｔ2 よりも厚くしている。また、送気送水チューブ２５の肉厚ｔ3 も送水チューブ３２の肉厚ｔ2 よりも厚く、送気チューブ３１の肉厚ｔ1 と同程度としてある。
【００６４】
また、送気チューブ３１の内径φ1 と送水チューブ３２の内径φ2 は、ほぼ同じとしても良いし、送気チューブ３１の内径φ1 の方を送水チューブ３２の内径φ2 よりも小さくしても良い。送気チューブ３１の内径φ1 を小さくした場合は、肉厚ｔ1 を厚くしても送気チューブ３１と送水チューブ３２の外径はほぼ同じとなるため、挿入部の外径が太径化してしまうことを防止できる。
【００６５】
本実施形態の絶縁カバー６９を先端部本体６４に組み付ける際には、接着剤を絶縁カバー６９の嵌合面に塗布し、先端部本体６４の第二凹部６４ｃに挿入する。この際、接着剤は第二凸部６４ｃの端面に一部しみ出すが、送気送水管路６９ｅを埋めてしまうことはない。
【００６６】
その他の部分の組立手順は前述した第１の実施形態と同様である。
【００６７】
本実施形態によれば、第一凸部６９ｂ，第一凹部６４ｂ及び第二凸部６９ｃ，第二凹部６４ｃを設けることにより、第１の実施形態と同様に先端カバー６９と先端部本体６４とを組み付ける際の組立作業性を向上させることができる。
【００６８】
また前記構成により、対物レンズ洗滌ノズル２１と絶縁カバー６９の嵌合長が長くなり接着面積が増加するので、対物レンズ洗滌ノズル２１と絶縁カバー６９の固定強度を増加させることができる。
【００６９】
さらに、送気送水管路６４ｅのような斜め孔が穿設されていても、先端部本体６４の送気送水管路６４ｅと絶縁カバー６９のノズル用貫通孔６９ｄとは段差なく確実に連通するので、掃除用ブラシ２３の挿脱時にひっかかることがなく、洗滌性が良好である。
【００７０】
また、第二凸部６９ｃの嵌合面にのみ接着剤を塗布することにより、ノズル用貫通孔６９ｄ及び送気送水管路６４ｅなどの貫通孔内に接着剤がしみ出すことを防止でき、かつ第二凸部６９ｃと第二凹部６４ｃとの嵌合部分の送気送水管路の水密を保つことができる。よって、挿入部先端部のどこからも水漏れするおそれがなく、送気送水の機能を不具合なく発揮することができる。
【００７１】
図１５及び図１６は本発明の第３の実施形態に係り、図１５は内視鏡の挿入部先端部の構成を示す軸方向断面図（図３と同一箇所の断面図）、図１６は図１５において断面Ｊ−Ｊで切った横断面図である。
【００７２】
第３の実施形態の絶縁カバー１１９は、処置具挿通パイプ３６を挿通する処置具挿通パイプ貫通孔１１９ｇの開口部の周囲において、挿入部軸方向後方に突出した第二凸部１１９ｃが設けられている。この第二凸部１１９ｃに対応して、先端部本体１１４側には、第二凸部１１９ｃが嵌合する第二凸部１１４ｃが設けられている。なお図示しないが、図２に示した第１の実施形態と同様に、絶縁カバー１１９と先端部本体１１４にはノズル用貫通孔の開口部の周囲においてそれぞれ第一凸部，第一凹部が設けられている。
【００７３】
その他の部分の構成、及び組立手順は第１の実施形態とほぼ同様であり、説明を省略する。
【００７４】
本実施形態の構成では、第一凸部，第一凹部及び第二凸部１１９ｃ，第二凹部１１４ｃを設けることにより、第１の実施形態と同様に先端カバー１１９と先端部本体１１４とを組み付ける際の組立作業性を向上させることができる。
【００７５】
また、第二凸部１１９ｃの嵌合面にのみ接着剤を塗布することにより、処置具挿通パイプ貫通孔１１９ｇ及び処置具挿通パイプ取付孔１１４ｆなどの貫通孔内に接着剤がしみ出すことを防止でき、挿入部先端部を組立てる際の不具合をなくすことができる。さらに、絶縁カバー１１９の第二凸部１１９ｃと先端部本体１１４の第二凹部１１４ｃの当接面に接着剤が充填されるため、絶縁カバー１１９と先端部本体１１４の嵌合部に隙間ができず、汚物がたまることを防止できる。また、処置具挿通パイプ３６による吸引管路部分の水密が保たれるので、吸引機能を不具合なく発揮することができる。
【００７６】
また前記構成により、絶縁カバー１１９と先端部本体１１４との嵌合長が長くなり接着面積が増加するので、絶縁カバー１１９と先端部本体１１４との固定強度を増加させることができる。また、絶縁カバー１１９と処置具挿通パイプ３６との嵌合長が長くなり接着面積が増加するので、処置具挿通パイプ３６の絶縁カバー１１９への固定強度を増加させることが可能になる。
【００７７】
［付記］
（１）挿入部先端を構成する先端部本体と、この先端部本体の外表面が露出しないよう該先端部本体の先端側を覆う絶縁カバーとを有し、前記先端部本体と絶縁カバーとを貫通する貫通孔を穿設した内視鏡において、
前記絶縁カバーに形成される貫通孔の開口部の周囲を凸状部に形成し、この凸状部に嵌合する凹状部を前記先端部本体の貫通孔の開口部周囲に形成したことを特徴とする内視鏡。
【００７８】
（２）挿入部先端を構成する先端部本体と、この先端部本体の外表面が露出しないよう該先端部本体の先端側を覆う絶縁カバーとを有し、前記先端部本体と絶縁カバーとを貫通する貫通孔を穿設した内視鏡において、
前記絶縁カバーの先端部側端部に第一凸状部を、前記先端部本体の先端部に前記第一凸状部に嵌合する第一凹状部をそれぞれ形成すると共に、
前記絶縁カバーに形成される貫通孔の開口部の周囲に前記第一凸状部よりも突出した第二凸状部を形成し、この第二凸状部に嵌合する第二凹状部を前記先端部本体の貫通孔の開口部周囲に形成したことを特徴とする内視鏡。
【００７９】
付記１または２の構成では、絶縁カバーと先端部本体にそれぞれ設けた凸状部と凹状部の嵌合部に接着剤を塗付して両者を固定する構造となっており、管路等を構成している貫通孔への接着剤のしみ出しを防止することができ、組立性を向上させることができる。また、接着面積が増加し、絶縁カバーと貫通孔に挿通する内蔵物との嵌合長及び先端部本体と絶縁カバーとの嵌合長が長くなるため、固定強度が増加する。さらにこの構成により、内視鏡先端部の水密及び管路の水密を確実に保持することができる。
【００８０】
（３）前記凸状部及び凹状部を、照明光伝達系を挿通する照明ユニット貫通孔の周囲に設けたことを特徴とする付記１に記載の内視鏡。
【００８１】
付記３の構成では、照明光伝達系を挿通する貫通孔への接着剤のしみ出しを防止することができ、挿入部先端部の照明光伝達系周辺の水密を確実に保持することが可能となる。
【００８２】
（４）前記凸状部及び凹状部を、洗滌用ノズルを挿通するノズル用貫通孔の周囲に設けたことを特徴とする付記１に記載の内視鏡。
【００８３】
付記４の構成では、洗滌用ノズルを挿通する貫通孔、すなわち送気送水管路の貫通孔への接着剤のしみ出しを防止することができ、挿入部先端部の送気送水管路周辺の水密を確実に保持することが可能となるため、送気送水の機能を不具合なく発揮することができる。
【００８４】
（５）前記凸状部及び凹状部を、処置具挿通パイプを挿通する処置具チャンネル貫通孔の周囲に設けたことを特徴とする付記１に記載の内視鏡。
【００８５】
付記５の構成では、処置具挿通管路を挿通する貫通孔、すなわち吸引管路を兼ねた処置具チャンネルの貫通孔への接着剤のしみ出しを防止することができ、挿入部先端部の吸引管路周辺の水密を確実に保持することが可能となるため、吸引機能を不具合なく発揮することができる。
【００８６】
【発明の効果】
以上説明したように本発明によれば、先端部本体の先端側に絶縁カバーを被覆して挿入部先端部を構成したものにおいて、貫通孔内に接着剤がしみ出すことを防止すると共に、絶縁カバーと先端部本体との接着強度及び水密性を保持でき、組立性及び内蔵物の絶縁カバーへの固定強度を向上させることが可能となる効果がある。
【図面の簡単な説明】
【図１】内視鏡システムの全体構成を示す構成説明図
【図２】本発明の第１の実施形態に係る内視鏡の挿入部先端部の構成を示す軸方向断面図（図４において断面Ｆ−Ｏ2 −Ｏ1 −Ｏ3 −Ｆ′で切った図）
【図３】本発明の第１の実施形態に係る内視鏡の挿入部先端部の構成を示す軸方向断面図（図４において断面Ｇ−Ｏ−Ｇ′で切った図）
【図４】挿入部先端部の先端面における配置構成を示す平面図（図２においてＡ方向から見た矢視図）
【図５】図２，図３において断面Ｃ−Ｃ，断面Ｅ−Ｅで切った横断面図
【図６】図２において断面Ｄ−Ｄで切った横断面図
【図７】図２において断面Ｂ−Ｂで切った横断面図
【図８】図５における係止ピンの変形例を示す横断面図
【図９】本発明の第２の実施形態に係る内視鏡の挿入部先端部の構成を示す軸方向断面図（図２と同一箇所の断面図）
【図１０】図９において断面Ｈ−Ｈで切った横断面図
【図１１】送気送水管路内を掃除する掃除用ブラシの外観構成を示す側面図
【図１２】送気送水パイプの変形例を示す軸方向断面図
【図１３】図１２の送気送水パイプをＩ方向から見た矢視図
【図１４】送気送水管路分岐部の構成を示す軸方向断面図
【図１５】本発明の第３の実施形態に係る内視鏡の挿入部先端部の構成を示す軸方向断面図（図３と同一箇所の断面図）
【図１６】図１５において断面Ｊ−Ｊで切った横断面図
【符号の説明】
２…内視鏡
３…挿入部
５…先端部
１４…先端部本体
１４ｂ…第一凹部
１４ｃ…第二凹部
１４ｄ…照明系取付孔
１４ｅ…送気送水管路
１４ｆ…処置具挿通パイプ取付孔
１９…絶縁カバー
１９ｂ…第一凸部
１９ｃ…第二凸部
１９ｄ…ノズル用貫通孔
１９ｆ…照明系貫通孔
１９ｇ…処置具挿通パイプ貫通孔
２０…対物観察ユニット
２１…対物レンズ洗滌ノズル
２２…係止ピン
２４…送気送水パイプ
２５…送気送水チューブ
３３…照明レンズユニット
３４…ライトガイド
３６…処置具挿通パイプ
３７…チャンネルチューブ[0001]
BACKGROUND OF THE INVENTION
  The present invention relates to an endoscope having an insertion portion provided with an observation optical system and the like.Tip ofIn particular, the present invention relates to an improvement in the joint structure between the distal end body and the insulating cover at the distal end of the insertion portion of the endoscope.
[0002]
[Prior art]
Endoscopes having an elongated insertion portion equipped with an observation optical system or the like are widely used in the medical field, the industrial field, and the like. The distal end of the insertion part of an endoscope is generally covered with a cover made of an insulating member on the distal end main body formed of a hard member such as metal to prevent electric shock of the subject and improve electrical safety. It is the composition made to do.
[0003]
Conventionally, as in Japanese Utility Model Publication No. 6-28081, the front end surface of the metal front end body is formed in a concave shape, and the rear end surface of an insulating cover formed of an electrically insulating member is formed in a convex shape. The convex portion is fitted into the concave portion of the tip portion main body and fixed with an adhesive. In addition, a through hole penetrating the tip portion main body and the insulating cover is drilled, and the tip of the built-in object is attached in the through hole. Between the plurality of through holes for attaching the tips of the built-in objects, the rear end surface of the insulating cover and the front surface of the metal tip portion main body are brought into contact with each other and bonded together.
[0004]
[Problems to be solved by the invention]
However, in the configuration in which the insulating cover and the tip end body are brought into contact with each other at the through hole portion as in the conventional example and bonded, if the adhesive is applied too much, the adhesive oozes out into the through hole during assembly. A defect that narrows or fills the hole occurs. Conversely, if the amount of adhesive applied is small, the watertightness between the through holes may not be maintained. If watertightness cannot be maintained, water will enter the endoscope from the gaps between the through-holes during cleaning, resulting in a malfunction.
[0005]
  The present invention has been made in view of these circumstances, and prevents the adhesive from oozing into the through hole in the structure in which the distal end side of the distal end portion body is covered with an insulating cover to constitute the distal end portion of the insertion portion. In addition, the endoscope can maintain the adhesive strength and water tightness between the insulating cover and the tip body, and can improve the assembling property and the strength of fixing the built-in object to the insulating cover.Tip ofThe purpose is to provide.
[0006]
[Means for Solving the Problems]
  Endoscope according to the present inventionTip ofHas a distal end body that constitutes the distal end of the insertion portion and an insulating cover that covers the distal end side of the distal end body so that the outer surface of the distal end body is not exposed, and penetrates the distal end body and the insulating cover. Endoscope with a through holeTip ofIn the periphery of the opening of the through hole formed in the insulating coverProvided on the periphery of the opening of the through hole of the tip body and provided on the fitting surface of the convex part and the concave part. And an adhesive surface for applying an adhesive to fix the insulating cover and the tip body.It is characterized byThe convex portion formed around the through hole of the insulating cover protrudes closer to the proximal side in the insertion portion axial direction than the portion where the through hole is not formed.
  Also, the distal end portion of the endoscope according to the present inventionIsA distal end body that constitutes the distal end of the insertion portion; and an insulating cover that covers the distal end side of the distal end body so that the outer surface of the distal end body is not exposed, and penetrates through the distal end body and the insulating cover At the tip of the endoscope with a hole,A first protrusion formed on a part of the insulating cover and protruding toward the proximal side in the insertion portion axial direction, and a first engagement formed on the tip body and engaged with the first protrusion. Formed in the periphery of the opening portion of the through hole formed in the insulating cover, the second projecting portion projecting closer to the proximal side in the insertion portion axial direction than the first projecting portion, and the tip body A second engaging portion that is formed and engages with the second protruding portion, and is provided on a fitting surface between the second protruding portion and the second engaging portion; And an adhesive surface to which an adhesive is applied for fixing the adhesive.
  In addition, the insulating cover fixing method according to the present invention is an insulating method for fixing an insulating cover that covers the distal end side of the distal end body to the distal end body constituting the distal end of the insertion portion so that the outer surface of the distal end body is not exposed. A method of fixing the cover,,Adheres to the fitting surface between the convex portion formed around the opening of the through hole provided in the insulating cover and the concave portion formed around the opening of the through hole provided in the tip body An agent is applied to fix the insulating cover and the tip body.
[0007]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below with reference to the drawings.
1 to 8 relate to a first embodiment of the present invention, FIG. 1 is a configuration explanatory view showing the entire configuration of the endoscope system, and FIGS. 2 and 3 show the configuration of the distal end portion of the insertion portion of the endoscope. FIG. 2 is a sectional view taken along the axial direction (FIG. 2 is a view taken along section FO2—O1—O3—F ′ in FIG. 4, FIG. 3 is a view taken along section GG ′ in FIG. 4), FIG. FIG. 5 is a plan view showing an arrangement configuration on the distal end surface of the distal end portion of the insertion portion (an arrow view as viewed from the direction A in FIG. 2), and FIG. 5 is a cross section cut along a section CC and a section EE in FIGS. 6 is a cross-sectional view taken along section DD in FIG. 2, FIG. 7 is a cross-sectional view taken along section BB in FIG. 2, and FIG. 8 is a modification of the locking pin in FIG. It is a cross-sectional view shown.
[0008]
The endoscope system 1 shown in FIG. 1 has an endoscope 2, which is an elongated and flexible insertion portion 3 and an operation connected to the proximal side of the insertion portion 3. Part 4.
[0009]
A rigid distal end portion 5 is provided on the distal end side of the insertion portion 3, and a bendable bending portion 6 is provided on the rear end side adjacent to the distal end portion 5.
[0010]
An insertion port 7 communicating with an insertion channel (not shown) disposed inside the endoscope is provided on the side of the operation unit 4 on the insertion unit 3 side. A bending operation knob 8 for bending the bending portion 6 by rotating the operation portion 4 is provided on the side portion on the proximal end side of the operation portion 4. Furthermore, a flexible universal cord 9 extends rearward from the back side of the bending operation knob 8 of the operation portion 4, and a connector 10 is provided at the end of the universal cord 9.
[0011]
The endoscope 1 is connected via a connector 10 and a universal cord 9 to a control device 11 in which a light source device including an illumination light source for observation and a video signal processing circuit are built. A color CRT monitor 12 is connected to the control device 11 as a display means by a video signal cable 13.
[0012]
As shown in FIGS. 2 to 7, the distal end main body 14 constituting the distal end portion 5 has various built-in objects to be described later, such as an observation optical system, an illumination light transmission system, and at least one of air supply or water supply. The pipes to be made are incorporated.
[0013]
On the other hand, the bending portion 6 is constituted by a plurality of bending pieces 15 made of a metal material being connected to each other by a rivet 17 so that the bending piece 15 is rotatably connected to the outer periphery of the bending piece 15 made of an electrically insulating synthetic resin. 18 is coated. The end portion of the outer skin 18 is tied and fixed by a fixing thread 47.
[0014]
An insulating cover 19 made of a synthetic resin such as polysulfone or an electrically insulating material such as ceramic is fitted on the distal end surface and the outer peripheral surface of the distal end main body 14. An objective observation unit 20 is detachably attached to the distal end main body 14 and the insulating cover 19 in the axial direction of the insertion portion.
[0015]
As shown in FIGS. 2 and 3, the objective observation unit 20 has an objective first lens 20a and an objective second lens 20b disposed at the tip thereof. An objective lens inner frame 50 for holding the objective first lens 20a and the objective second lens 20b is provided, and an objective lens outer frame 39 is disposed on the outer peripheral portion of the objective lens inner frame 50 on the operation unit side. .
[0016]
The objective lens outer frame 39 has an O-ring 40 attached to the outer peripheral groove 39a, and further fits into an objective lens frame attachment hole 14g penetrating the distal end portion main body 14. Further, a V-shaped groove 39b provided in the middle of the outer periphery of the objective lens outer frame 39 has a conical tip 41a of the objective observation unit fixing screw 41 on a slope 39c disposed on the tip side of the two slopes. Are in contact with each other.
[0017]
As shown in FIG. 5, the objective observation unit fixing screw 41 is screwed into a screw hole 14 h provided through the objective lens frame mounting hole 14 g from the outer periphery of the tip body 14, and is attached to the tip body 14. The objective observation unit 20 is fixed.
[0018]
At this time, after the objective lens outer frame 39 is inserted into the objective lens frame mounting hole 14g, the O-ring 40 of the wall surface of the objective lens frame mounting hole 14g does not interfere with the screw hole 14h. A U-shaped groove 14i is provided in the sliding portion with the U-shaped groove 14i beyond the screw hole 14h to the tip, and the U-shaped groove 14i prevents interference between the O-ring 40 and the screw hole 14h.
[0019]
As shown in FIGS. 2 and 3, the insulating cover 19 is formed in a substantially cap shape so that the distal end side end surface 14 a of the distal end portion main body and the operating portion side end surface 19 a of the insulating cover are in contact with each other.
[0020]
A nozzle through hole 19d is formed in the insulating cover 19 in the axial direction of the insertion portion, and an objective lens cleaning nozzle for cleaning the surface of the objective first lens 20a of the objective observation unit 20 is provided in the nozzle through hole 19d. 21 is fitted and locked in the insulating cover 19 by a locking pin 22 inserted in the radial direction of the insertion portion as shown in FIG.
[0021]
The locking pin mounting hole 19h through which the locking pin 22 is inserted communicates with a nozzle through hole 19d provided in the insulating cover 19, and penetrates in a radial direction from the nozzle through hole 19d toward the outer periphery of the insulating cover 19. doing. The locking pin 22 is fixed to the insulating cover 19 by fitting into the locking pin mounting hole 19h and applying an adhesive that is easily peeled off by a silicone system to the fitting portion. The outer surface end 22b of the locking pin 22 is formed in an arcuate curved surface so as to coincide with the outer peripheral surface of the insulating cover 19 when assembled.
[0022]
Further, the other end of the locking pin 22 is formed with a tip 22 a having an arcuate end surface that engages with an engaging recess 21 b provided on the side peripheral portion of the objective lens cleaning nozzle 21. The distal end portion 22a engages with the engagement concave portion 21b of the objective lens cleaning nozzle 21 in a direction perpendicular to the attaching / detaching direction (the insertion portion distal end direction) of the objective lens cleaning nozzle 21 to lock the objective lens cleaning nozzle 21. It is like that.
[0023]
Note that the locking pin 22 may be modified as shown in FIG. That is, by providing the small-diameter portion 22c in a part of the locking pin 22 and applying the adhesive only to the portion other than the small-diameter portion 22c, the application amount of the adhesive can be regulated. It is also possible to improve the removal property of 22.
[0024]
The nozzle through-hole 19d communicates with the air / water supply conduit 14e of the tip body 14, and an air / water supply pipe 24 is attached to the rear end of the air / water supply conduit 14e. An air / water supply tube 25 is connected to the rear end of the air / water supply pipe 24.
[0025]
As shown in FIG. 5, the distal end body 14 and the insulating cover 19 are provided with fixing holes 14j and 19j, respectively, and the distal end body 14 and the insulating cover 19 are fixed by filling the adhesive holes therein. It has a structure.
[0026]
The insulating cover 19 and the tip body 14 are provided with an illumination lens unit 33 that constitutes an illumination light transmission system, and a light guide 34 made of an optical fiber bundle is continuously provided on the proximal side of the illumination lens unit 33. ing. The light guide 34 prevents the light guide from being broken by other built-in objects by covering the light guide protection tube 48. The tip of the light guide protection tube 48 is tied and fixed by a fixing thread 49.
[0027]
A light guide frame 44 is attached to the tip of the light guide 34, and is inserted from behind into an illumination system mounting hole 14d that penetrates the tip main body 14 in the axial direction, and is fixed in the tip main body 14 as shown in FIG. It is fixed by screws 42. On the other hand, the illumination lens unit 33 is fixed to the illumination system mounting hole 14d with an adhesive.
[0028]
The insulating cover 19 is provided with an illumination system through hole 19f at a position facing the illumination system mounting hole 14d. The illumination system through hole 19f is provided with an illumination lens unit 33 having an illumination lens 33a disposed inside the tip. The tip is bonded and fixed. An outer frame flange portion 35 is provided on the outer periphery in the vicinity of the distal end of the illumination lens unit 33, and the outer frame flange portion 35 abuts on the distal end surface of the distal end portion main body 14, whereby the illumination lens unit 33 is positioned in the axial direction. Can be decided.
[0029]
In the present embodiment, as shown in FIG. 2, the first convex portion 19b is formed around the opening of the nozzle through hole 19d to which the objective lens cleaning nozzle 21 is attached. Correspondingly, the distal end main body 14 is provided with a first recessed portion 14b in which the first projected portion 19b is fitted around the distal end side of the air / water supply conduit 14e. In addition, a second convex portion 19c that protrudes rearward in the insertion portion axial direction from the first convex portion 19b is formed around the opening of the illumination system through hole 19f for attaching the illumination light transmission system. Correspondingly, the distal end main body 14 is provided with a second concave portion 14c in which the second convex portion 19c is fitted around the distal end side of the illumination system mounting hole 14d.
[0030]
As shown in FIG. 3, a treatment instrument insertion pipe 36 that constitutes the distal end of the treatment instrument channel is attached to the insulating cover 19 and the distal end main body 14. The treatment instrument insertion pipe 36 penetrates the distal end main body 14 in the axial direction at a position facing the treatment instrument insertion pipe through hole 19g and the treatment instrument insertion pipe through hole 19g penetrating the insulating cover 19 in the insertion section axial direction. It fits and is fixed to the treatment instrument insertion pipe mounting hole 14f.
[0031]
The treatment instrument insertion pipe 36 extends from the rear end surface of the distal end main body 14 toward the operation section, and a channel tube 37 is connected to the operation section side of the treatment instrument insertion pipe 36. The distal end of the channel tube 37 is fixed to the treatment instrument insertion pipe 36 by fixing the outer periphery of the channel tube 37 with a thread around the fixing tube 38 and closely adhering the adhesive surface. Further, the channel tube 37 is provided with a spiral groove 37a on the outer periphery, thereby improving the bending property and reducing the amount of bending operation, and by winding the coil 45 around the groove 37a, Therefore, the channel tube 37 is prevented from buckling by providing a certain level of strength.
[0032]
Next, a procedure for assembling the distal end portion 5 of the endoscope 2 configured as described above will be described below.
[0033]
First, the air / water pipe 24 and the treatment instrument insertion pipe 36 are positioned on the distal end body 14 and fixed by soldering.
[0034]
Next, an adhesive is applied to the outer periphery of the illumination lens unit 33 and inserted until the outer frame flange portion 35 of the illumination lens unit 33 comes into contact with the distal end portion main body 14. Further, an adhesive is applied to the contact surfaces of the insulating cover 19 and the tip end main body 14, and both are bonded and cured. In addition, a light guide protection tube 48 is externally mounted on the light guide 34 and fixed with a fixing thread 49.
[0035]
2 and 3, the clearance between the treatment instrument insertion pipe 36 and the treatment instrument insertion pipe through hole 19g provided in the insulating cover 19, the clearance between the illumination lens unit 33 and the insulation cover 19, the air / water supply pipe 24, Adhesive is hermetically filled and cured in a total of three locations, including the gap with the insulating cover 19, so as to have the structure described above.
[0036]
Further, an adhesive is applied to one end of the treatment instrument insertion pipe 36 to fit the channel tube 37, and the outer periphery of almost the entire area of the bonded portion of the channel tube 37 is fixed with a fixing thread 38. In this way, the channel tube 37 is brought into close contact with the rear end of the treatment instrument insertion pipe 36 and cured. Further, the coil 45 is packaged along the groove 37 a of the channel tube 37.
[0037]
Next, an adhesive is applied to the lens frame step portion 50a of the objective observation unit 20 shown in FIGS. 2 and 3, and inserted until it contacts the step portion 14g of the objective lens frame mounting hole of the tip end main body 14 to fix the objective observation unit. Secure with screws 41. Then, an adhesive is hermetically filled in a gap formed when the objective observation unit 20 is fitted to the insulating cover 19.
[0038]
Further, an adhesive is applied to the outer periphery of the objective lens cleaning nozzle 21 and inserted to the contact surface 19 k of the insulating cover 19. Further, the objective lens cleaning nozzle 21 is positioned so that the opening 21a opens in the direction of the objective first lens 20a, and the injection direction of air supply or water supply is adjusted.
[0039]
Further, an adhesive is applied to the locking pin mounting hole 19h provided in the insulating cover 19 shown in FIG. 7, the locking pin 22 is inserted into the locking pin mounting hole 19h, and the tip 22a of the locking pin 22 is attached. For example, the adhesive is cured by bringing it into contact with the engaging recess 21b of the objective lens cleaning nozzle 21. As a result, the objective lens cleaning nozzle 21 does not come out of the insulating cover 19 until the locking pin 22 is broken or removed.
[0040]
At this time, the first convex portion 19b is fitted into the first concave portion 14b. At this time, the first convex portion 19b serves as a guide in mounting the insulating cover 19, and the insulating cover 19 and the distal end portion main body 14 are in contact with each other. Each of the through holes, for example, the nozzle through hole 19d and the air / water supply conduit 14e, the objective lens frame insertion hole 19i, and the objective lens frame mounting hole 14g can be positioned. Thereby, the assemblability when the insulating cover 19 is mounted is improved.
[0041]
When the insulating cover 19 is assembled to the tip main body 14, a portion where the insulating cover 19 and the tip main body 14 are fitted and abutted with each other, such as the operation portion side end surface 19a, the first convex portion 19b, and the second convex portion. Apply to 19c.
[0042]
Here, as a procedure for applying the adhesive, an application of the adhesive relating to the periphery of the second convex portion 19c will be described as an example. Adhesive is applied to the fitting surface of the insulating cover 19 and inserted into the second recess 14 c of the tip body 14. At this time, the adhesive partially oozes out on the end surface of the second convex portion 14c, but oozes out into the illumination system through hole 19f for mounting the illumination lens unit 33 and the illumination system mounting hole 14d and fills the through hole. There is nothing.
[0043]
Finally, the fixing holes 14j and 19j provided in the side portions of the tip body 14 and the insulating cover 19 are filled with an adhesive to fix them.
[0044]
As described above, in the present embodiment, by providing the first convex portion 19b, the first concave portion 14b, the second convex portion 19c, and the second concave portion 14c, the tip cover 19 and the tip portion main body 14 are assembled. Assembly workability can be improved.
[0045]
Moreover, since the fitting length of the illumination lens unit 33 and the insulating cover 19 is increased and the bonding area is increased, the fixing strength of the illumination lens unit 33 and the insulating cover 19 can be increased. Further, since the fitting length between the insulating cover 19 and the tip body 14 is increased and the adhesion surface is increased, the fixing strength between the insulating cover 19 and the tip body 14 can be increased, and the water tightness is also improved. It becomes possible.
[0046]
Further, by applying an adhesive only to the fitting surface of the second convex portion 19c, the adhesive is adhered in the through holes for attaching built-in objects such as the illumination system through hole 19f and the illumination system attachment hole 14d for attaching the illumination lens unit 33. It is possible to prevent the agent from oozing out, and to eliminate problems when assembling the distal end portion of the insertion portion.
[0047]
In the following second and third embodiments, an example is shown in which the configuration of the concavo-convex portion for fitting the insulating cover and the tip body in the first embodiment described above is changed.
[0048]
9 to 14 relate to a second embodiment of the present invention, FIG. 9 is an axial sectional view showing the configuration of the distal end portion of the insertion portion of the endoscope (a sectional view of the same portion as FIG. 2), and FIG. 9 is a cross-sectional view taken along a section H-H, FIG. 11 is a side view showing an external configuration of a cleaning brush for cleaning the inside of the air / water supply conduit, and FIG. 12 is a shaft showing a modification of the air / water supply pipe. FIG. 13 is an arrow sectional view of the air / water pipe shown in FIG. 12 as viewed from the I direction, and FIG.
[0049]
As shown in FIGS. 9 and 10, the insulating cover 69 of the second embodiment is formed with the first convex portion 69b and the first convex portion, as in the first embodiment shown in FIG. A second convex portion 69c that protrudes rearward in the insertion portion axial direction is provided around the opening of the nozzle through hole 69d from the portion 69b. In other words, the locking pin mounting hole 69h into which the locking pin 22 for locking the objective lens cleaning nozzle 21 is fitted is provided to protrude further from the first convex portion 69b which is thicker to the operation portion side. The second convex portion 69c is provided, and a two-step convex portion is formed.
[0050]
Corresponding to the first convex portion 69b and the second convex portion 69c, the first concave portion 64b into which the first convex portion 69b is fitted and the second convex portion 69c are fitted into the front end portion main body 64 side. Two recesses 64c are provided.
[0051]
The configuration of the other parts is almost the same as that of the first embodiment, and the description is omitted.
[0052]
In the present embodiment, when the insulating cover 69 is assembled to the tip end body 64, the second convex portion 69c and the second concave portion 64c are fitted, so the air / water supply conduit 64e and the nozzle through-hole 69d. Are communicated without steps, so that the cleaning brush does not get caught during washing in the pipeline, and dirt does not collect easily.
[0053]
When cleaning the inside of the pipe such as the air / water supply pipe 64e, a cleaning brush 23 as shown in FIG. 11 is used. In this embodiment, in order to improve the insertability of the cleaning brush 23, the tip body 64 is provided with an air / water supply conduit 64e at an angle, so the central axis d1 of the objective lens cleaning nozzle 21 and the tip body 64 is arranged so as to be shifted from the pipe center d2 at the end face 64a on the tip end side. As a result, the cleaning brush 23 can be smoothly inserted from the oblique hole to the straight hole, and the insertion property is improved as compared with the case where the center is not shifted.
[0054]
Moreover, since the air / water supply conduit 64e is provided obliquely on the distal end portion main body 64, the cross-sectional shape of the distal end side end surface 64a becomes an ellipse. Therefore, the pipe relay section 69e that connects the nozzle through-hole 69d of the insulating cover 69 and the air / water supply conduit 64e has a round circular shape on the nozzle through-hole 69d side and an elliptical cross-sectional shape on the air / water supply conduit 64e side. It has become.
[0055]
Here, since the opening end of the hole of the pipe relay part 69e is made into an ellipse having the same shape as the cross-sectional shape of the front end side end face 64a of the air / water feeding pipe line 64e, no step is generated, so the cleaning brush 23 There is no seizure, and the washability is improved. In addition, when the level | step difference of the pipe relay part 69e and the air / water supply pipe 64e is small, it is good also considering the cross-sectional shape of the opening end of the pipe relay part 69e as a perfect circle.
[0056]
Further, the pipe relay part 69e of the insulating cover 69 is not provided with a step even in a portion where the cross-sectional shape changes from a round cross section to an elliptical cross section toward the air / water supply pipe line 64e in order to improve the washability, It is connected smoothly.
[0057]
In addition, the bending angle θ of the air / water supply pipe 24 connected to the rear end of the air / water supply pipe 64e is set to 15 ° or less in consideration of the insertion property of the cleaning brush 23.
[0058]
The air / water supply pipe 24 can be shaped as shown in FIGS. 12 and 13 in order to improve the insertion of the cleaning brush 23. In this modification, the air / water pipe 24a is penetrated to the tip of the air / water pipe 14e, and an enlarged hole 28 is provided in a part of the inner diameter of the air / water pipe 24a. As a result, the cleaning brush 23 can be smoothly inserted.
[0059]
Further, in order to increase the bonding area between the tip body 14 and the air / water pipe 24a and increase the bonding strength, a flat portion 29 is provided by processing a part of the outer diameter of the air / water pipe 24a.
[0060]
One end of the air / water supply pipe 24a is fixed to the tip main body 14 by soldering, and the other end is connected to one end of an air / water supply tube 25 which is inserted through the insertion portion. The air / water supply tube 25 is fixed to the air / water supply pipe 24 a by binding the outer periphery in the vicinity of the tip with a fixing thread 26. A heat shrinkable tube 27 is in close contact with the tube fixing portion in order to bring the adhesive surface of the air / water supply tube 25 into close contact with the rear end side of the air / water supply pipe 24a. Further, a protective tube 43 is externally provided to prevent the air / water supply tube 25 from being damaged by other built-in objects.
[0061]
The proximal end of the air / water supply tube 25 is connected to an air / water supply pipe branch 30 as shown in FIG. One end of an air supply tube 31 is connected to the air supply pipe 30a of the air supply / water supply pipe branch 30 and one end of a water supply tube 32 is connected to the water supply pipe 30b. The other ends of the air supply tube 31 and the water supply tube 32 are connected to a pipe switching device (not shown) provided in the operation unit 4. Further, in order to improve workability, there are provided squeezed portions 31a and 32a having slightly smaller diameters near the ends of the air supply tube 31 and the water supply tube 32.
[0062]
The air supply pipe 30a and the water supply pipe 30b are connected and fixed by a soldering portion 53. At the time of assembly, each tube is connected to the air / water supply pipe branch 30 and then an adhesive is applied to improve the strength to form an adhesive layer 54.
[0063]
In such an air / water supply conduit, there is a problem that if cleaning is repeated, the inner diameter of the tube is scraped by the cleaning brush 23, the tube thickness becomes thin, and the tube tends to buckle. Therefore, as shown in FIG. 14, the thickness t1 of the air supply tube 31 through which the cleaning brush 23 passes is made thicker than the thickness t2 of the water supply tube 32. The thickness t3 of the air / water supply tube 25 is also thicker than the thickness t2 of the water supply tube 32, and is approximately the same as the thickness t1 of the air supply tube 31.
[0064]
The inner diameter φ1 of the air supply tube 31 and the inner diameter φ2 of the water supply tube 32 may be substantially the same, or the inner diameter φ1 of the air supply tube 31 may be smaller than the inner diameter φ2 of the water supply tube 32. If the inner diameter φ1 of the air supply tube 31 is reduced, the outer diameters of the air supply tube 31 and the water supply tube 32 are substantially the same even if the wall thickness t1 is increased, so that the outer diameter of the insertion portion is increased. Can be prevented.
[0065]
When the insulating cover 69 of this embodiment is assembled to the tip end body 64, an adhesive is applied to the fitting surface of the insulating cover 69 and inserted into the second recess 64 c of the tip end body 64. At this time, the adhesive partly oozes out to the end face of the second convex portion 64c, but does not fill the air / water supply conduit 69e.
[0066]
The assembly procedure of other parts is the same as that of the first embodiment described above.
[0067]
According to the present embodiment, by providing the first convex portion 69b, the first concave portion 64b, the second convex portion 69c, and the second concave portion 64c, the distal end cover 69 and the distal end portion main body 64 are similar to the first embodiment. Assembling workability at the time of assembling can be improved.
[0068]
Further, with the above-described configuration, the fitting length between the objective lens cleaning nozzle 21 and the insulating cover 69 is increased and the adhesion area is increased, so that the fixing strength of the objective lens cleaning nozzle 21 and the insulating cover 69 can be increased.
[0069]
Furthermore, even if an oblique hole such as the air / water supply pipe 64e is formed, the air / water supply pipe 64e of the tip body 64 and the nozzle through-hole 69d of the insulating cover 69 communicate with each other without any step. Therefore, it does not get caught when the cleaning brush 23 is inserted and removed, and the cleaning property is good.
[0070]
Further, by applying the adhesive only to the fitting surface of the second convex portion 69c, it is possible to prevent the adhesive from oozing into the through holes such as the nozzle through hole 69d and the air / water supply conduit 64e, and The airtightness of the air / water supply conduit at the fitting portion between the second convex portion 69c and the second concave portion 64c can be maintained. Therefore, there is no possibility of water leaking from anywhere in the distal end portion of the insertion portion, and the air / water feeding function can be exhibited without any problems.
[0071]
15 and 16 relate to a third embodiment of the present invention. FIG. 15 is an axial sectional view (sectional view of the same portion as FIG. 3) showing the configuration of the distal end portion of the insertion portion of the endoscope. FIG. FIG. 16 is a transverse sectional view taken along a section JJ in FIG. 15.
[0072]
The insulating cover 119 of the third embodiment is provided with a second convex portion 119c that protrudes rearward in the insertion portion axial direction around the opening of the treatment instrument insertion pipe through hole 119g through which the treatment instrument insertion pipe 36 is inserted. Yes. Corresponding to the second convex portion 119c, a second convex portion 114c into which the second convex portion 119c is fitted is provided on the distal end portion main body 114 side. Although not shown, as in the first embodiment shown in FIG. 2, the insulating cover 119 and the tip body 114 are provided with a first convex portion and a first concave portion around the opening of the nozzle through hole, respectively. It has been.
[0073]
The configuration of the other parts and the assembling procedure are almost the same as those in the first embodiment, and a description thereof will be omitted.
[0074]
In the configuration of the present embodiment, by providing the first convex portion, the first concave portion and the second convex portion 119c, and the second concave portion 114c, the tip cover 119 and the tip portion main body 114 are assembled similarly to the first embodiment. Assembling workability at the time can be improved.
[0075]
Further, by applying an adhesive only to the fitting surface of the second convex portion 119c, it is possible to prevent the adhesive from seeping into the through holes such as the treatment instrument insertion pipe through hole 119g and the treatment instrument insertion pipe mounting hole 114f. It is possible to eliminate the troubles when assembling the distal end portion of the insertion portion. Furthermore, since the adhesive is filled in the contact surface between the second convex portion 119c of the insulating cover 119 and the second concave portion 114c of the tip body 114, there is a gap between the fitting portion between the insulating cover 119 and the tip body 114. Therefore, it is possible to prevent filth from accumulating. In addition, since the water tightness of the suction conduit portion by the treatment instrument insertion pipe 36 is maintained, the suction function can be exhibited without any trouble.
[0076]
In addition, with the above-described configuration, the fitting length between the insulating cover 119 and the tip portion main body 114 is increased and the bonding area is increased, so that the fixing strength between the insulating cover 119 and the tip portion main body 114 can be increased. In addition, since the fitting length between the insulating cover 119 and the treatment instrument insertion pipe 36 is increased and the adhesion area is increased, the fixing strength of the treatment instrument insertion pipe 36 to the insulation cover 119 can be increased.
[0077]
[Appendix]
(1) A distal end body that constitutes the distal end of the insertion section, and an insulating cover that covers the distal end side of the distal end body so that the outer surface of the distal end body is not exposed. In an endoscope having a through-hole penetrating,
The periphery of the opening portion of the through hole formed in the insulating cover is formed as a convex portion, and the concave portion that fits into the convex portion is formed around the opening portion of the through hole of the tip body. Endoscope.
[0078]
(2) a distal end main body that constitutes the distal end of the insertion portion; and an insulating cover that covers the distal end side of the distal end main body so that the outer surface of the distal end main body is not exposed. In an endoscope having a through-hole penetrating,
Forming a first convex portion at the end portion side end portion of the insulating cover, and forming a first concave portion fitting into the first convex portion at the distal end portion of the distal end body;
A second convex portion protruding from the first convex portion is formed around the opening portion of the through hole formed in the insulating cover, and the second concave portion fitted to the second convex portion is An endoscope formed around an opening of a through hole of a tip body.
[0079]
In the structure of Supplementary Note 1 or 2, it has a structure in which an adhesive is applied to the fitting part of the convex part and the concave part respectively provided on the insulating cover and the tip part body, and both are fixed. It is possible to prevent the adhesive from seeping out into the through-holes that are formed, and to improve the assemblability. Further, the bonding area is increased, and the fitting length between the insulating cover and the built-in object inserted through the through hole and the fitting length between the tip body and the insulating cover are increased, so that the fixing strength is increased. Furthermore, with this configuration, the watertightness of the endoscope distal end and the watertightness of the pipe line can be reliably maintained.
[0080]
(3) The endoscope according to appendix 1, wherein the convex portion and the concave portion are provided around an illumination unit through-hole through which the illumination light transmission system is inserted.
[0081]
With the configuration of Supplementary Note 3, it is possible to prevent the adhesive from seeping out into the through hole that passes through the illumination light transmission system, and to reliably maintain the water tightness around the illumination light transmission system at the distal end of the insertion portion. Become.
[0082]
(4) The endoscope according to appendix 1, wherein the convex portion and the concave portion are provided around a nozzle through-hole through which the washing nozzle is inserted.
[0083]
In the configuration of Supplementary Note 4, it is possible to prevent the adhesive from seeping out into the through-hole through which the cleaning nozzle is inserted, that is, the through-hole of the air / water supply conduit, Since it becomes possible to hold watertight reliably, the function of air / water feeding can be exhibited without any problems.
[0084]
(5) The endoscope according to appendix 1, wherein the convex portion and the concave portion are provided around a treatment instrument channel through-hole through which the treatment instrument insertion pipe is inserted.
[0085]
With the configuration of Supplementary Note 5, it is possible to prevent the adhesive from seeping out into the through hole that passes through the treatment instrument insertion conduit, that is, the through hole of the treatment instrument channel that also serves as the suction conduit, and suction of the distal end of the insertion portion Since the water tightness around the pipe line can be reliably maintained, the suction function can be exhibited without any trouble.
[0086]
【The invention's effect】
As described above, according to the present invention, the distal end side of the distal end portion body is covered with the insulating cover to constitute the distal end portion of the insertion portion, and the adhesive is prevented from oozing into the through hole and insulated. Adhesive strength and watertightness between the cover and the tip main body can be maintained, and there is an effect that it is possible to improve the assembling property and the strength of fixing the built-in object to the insulating cover.
[Brief description of the drawings]
FIG. 1 is an explanatory diagram showing the overall configuration of an endoscope system.
FIG. 2 is an axial cross-sectional view showing the configuration of the distal end portion of the insertion portion of the endoscope according to the first embodiment of the present invention (a view cut along a cross section F-O2-O1-O3-F 'in FIG. 4).
3 is an axial cross-sectional view showing the configuration of the distal end portion of the insertion portion of the endoscope according to the first embodiment of the present invention (a view cut along a cross section G-O-G 'in FIG. 4).
FIG. 4 is a plan view showing an arrangement configuration on the distal end surface of the distal end portion of the insertion portion (viewed from the direction A in FIG. 2).
5 is a cross-sectional view taken along section CC and section EE in FIGS. 2 and 3. FIG.
6 is a cross-sectional view taken along section DD in FIG.
7 is a cross-sectional view taken along section BB in FIG.
8 is a cross-sectional view showing a modification of the locking pin in FIG.
FIG. 9 is an axial sectional view showing the configuration of the distal end portion of the insertion portion of the endoscope according to the second embodiment of the present invention (cross sectional view at the same position as FIG. 2).
10 is a cross-sectional view taken along section HH in FIG. 9;
FIG. 11 is a side view showing an external configuration of a cleaning brush for cleaning the inside of an air / water supply pipeline.
FIG. 12 is an axial sectional view showing a modification of the air / water pipe.
13 is an arrow view of the air / water pipe of FIG. 12 as viewed from the I direction.
FIG. 14 is an axial sectional view showing a configuration of an air / water supply pipe branching portion.
FIG. 15 is an axial sectional view showing a configuration of an insertion portion distal end portion of an endoscope according to a third embodiment of the present invention (cross sectional view of the same portion as FIG. 3).
16 is a cross-sectional view taken along section JJ in FIG.
[Explanation of symbols]
2. Endoscope
3 ... Insertion section
5 ... Tip
14 ... tip body
14b ... 1st recessed part
14c ... second recess
14d ... Lighting system mounting hole
14e… Air / water supply pipeline
14f ... Treatment instrument insertion pipe mounting hole
19 ... Insulation cover
19b ... 1st convex part
19c ... second convex part
19d ... Nozzle through hole
19f ... Lighting system through hole
19g ... treatment instrument insertion pipe through hole
20 ... Objective observation unit
21 ... Objective lens cleaning nozzle
22 ... Locking pin
24 ... Air / water pipe
25 ... Air / water tube
33 ... Lighting lens unit
34 ... Light guide
36 ... Treatment tool insertion pipe
37 ... Channel tube

Claims

A distal end body that constitutes the distal end of the insertion portion; and an insulating cover that covers the distal end side of the distal end body so that the outer surface of the distal end body is not exposed, and penetrates through the distal end body and the insulating cover At the tip of the endoscope with a hole,
A convex portion provided around the opening portion of the through hole formed in the insulating cover, a concave portion provided around the opening portion of the through hole of the tip body, and fitted into the convex portion; A distal end portion of an endoscope , which is provided on a fitting surface between the convex portion and the concave portion, and has an adhesive surface to which an adhesive is applied to fix the insulating cover and the distal end portion main body. .

The internal view according to claim 1, wherein the convex portion formed around the through hole of the insulating cover protrudes closer to the proximal side in the insertion portion axial direction than a portion where the through hole is not formed. The tip of the mirror .

A distal end body that constitutes the distal end of the insertion portion; and an insulating cover that covers the distal end side of the distal end body so that the outer surface of the distal end body is not exposed, and penetrates through the distal end body and the insulating cover At the tip of the endoscope with a hole ,
A first protrusion formed on a part of the insulating cover and protruding toward the proximal side in the insertion portion axial direction, and a first engagement formed on the tip body and engaged with the first protrusion. Formed in the periphery of the opening portion of the through hole formed in the insulating cover, the second projecting portion projecting closer to the proximal side in the insertion portion axial direction than the first projecting portion, and the tip body A second engaging portion that is formed and engages with the second protruding portion, and is provided on a fitting surface between the second protruding portion and the second engaging portion; And an adhesive surface to which an adhesive is applied to fix the endoscope .

An insulating cover fixing method for fixing an insulating cover that covers the distal end side of the distal end portion main body so that the outer surface of the distal end portion main body is not exposed to the distal end portion main body constituting the distal end of the insertion portion ,
Adheres to the fitting surface between the convex portion formed around the opening of the through hole provided in the insulating cover and the concave portion formed around the opening of the through hole provided in the tip body A method of fixing an insulating cover, comprising applying an agent to fix the insulating cover and the tip body .