JP5996307B2

JP5996307B2 - Endoscope

Info

Publication number: JP5996307B2
Application number: JP2012153866A
Authority: JP
Inventors: 大悟梯
Original assignee: Olympus Corp
Current assignee: Olympus Corp
Priority date: 2012-07-09
Filing date: 2012-07-09
Publication date: 2016-09-21
Anticipated expiration: 2032-07-09
Also published as: JP2014014502A

Description

本発明は、内視鏡に関し、特に、湾曲部の湾曲長を変更できる内視鏡に関する。 The present invention relates to an endoscope, and more particularly to an endoscope that can change the bending length of a bending portion.

従来より、医療分野及び工業分野では内視鏡が広く利用されている。例えば、医療分野では、術者が被検体内に内視鏡の挿入部を挿入し、挿入部の先端部に設けた撮像部において撮像された被検体内の画像をモニタに表示させ、被検体内の検査を行うことができる。
さらに、内視鏡の挿入部の先端側には、湾曲部が設けられており、術者は、例えば、内視鏡の操作部の湾曲ノブを操作することにより、湾曲部を所望の方向に湾曲させることができる。 Conventionally, endoscopes have been widely used in the medical field and the industrial field. For example, in the medical field, an operator inserts an insertion portion of an endoscope into a subject, displays an image in the subject taken by an imaging portion provided at the distal end of the insertion portion on a monitor, and Can be inspected.
Furthermore, a bending portion is provided on the distal end side of the insertion portion of the endoscope, and the operator operates the bending knob of the operation portion of the endoscope, for example, to move the bending portion in a desired direction. Can be curved.

また、近年、被検体への挿入性の向上のために、例えば特開２００５−４６２７９号公報及び特開２００２−１７７２０１号公報に開示のように、１つの湾曲部において湾曲長を変更することができる内視鏡が提案されている。
例えば、特許第４８５６２８９号公報には、挿入部内に設けられた柔軟な外側ガイドパイプの先端は可撓管部の先端部に固定され、さらに挿入部内に設けられワイヤが挿通された柔軟な内側ガイドパイプの先端は、湾曲部の途中位置に固定され、内側ガイドパイプの基端の状態を固定状態又は非固定状態に切り換えることができるようにした内視鏡が、提案されている。 In recent years, in order to improve the insertion property into the subject, the bending length can be changed in one bending portion as disclosed in, for example, Japanese Patent Application Laid-Open Nos. 2005-46279 and 2002-177201. Endoscopes that can be used have been proposed.
For example, Japanese Patent No. 4856289 discloses a flexible inner guide pipe in which a distal end of a flexible outer guide pipe provided in an insertion portion is fixed to a distal end portion of a flexible tube portion and a wire is inserted in the insertion portion. An endoscope has been proposed in which the distal end of the pipe is fixed at a middle position of the bending portion, and the state of the proximal end of the inner guide pipe can be switched between a fixed state and an unfixed state.

その提案によれば、内側ガイドパイプの基端の状態を固定状態にすると、湾曲部の先端側の第１の部位だけを湾曲させることができ、内側ガイドパイプの基端の状態を非固定状態にすると、湾曲部の先端側の第１の部位と基端側の第２の部位の両方を湾曲させることができる。
従って、このような内視鏡によれば、挿入部の１つの湾曲部において湾曲長を変更させることができるため、内視鏡の挿入性を向上させることができる。 According to the proposal, when the state of the proximal end of the inner guide pipe is set to the fixed state, only the first portion on the distal end side of the bending portion can be bent, and the state of the proximal end of the inner guide pipe is set to the unfixed state. Then, both the first part on the distal end side and the second part on the proximal end side of the bending portion can be curved.
Therefore, according to such an endoscope, since the bending length can be changed in one bending portion of the insertion portion, the insertion property of the endoscope can be improved.

特開２００５−４６２７９号公報JP 2005-46279 A 特開２００２−１７７２０１号公報JP 2002-177201 A 特許第４８５６２８９号公報Japanese Patent No. 4856289

しかし、１つの湾曲部において湾曲長を変更できるようにしても、上記の提案に係る内視鏡のように、第２の部位に内側ガイドパイプが挿通されているような場合、湾曲部の先端側の第１の部位と基端側の第２の部位の両方を湾曲させると、第２の部位には第１の部位には無い内側ガイドパイプが挿通されているので、第２の部位は第１の部位よりも曲がり難い。 However, even if the bending length can be changed in one bending portion, when the inner guide pipe is inserted into the second portion as in the endoscope according to the above proposal, the tip of the bending portion When both the first part on the side and the second part on the proximal end side are curved, the inner guide pipe that is not present in the first part is inserted into the second part, so the second part is It is harder to bend than the first part.

そのため、第１と第２の部位の両方を湾曲させた湾曲状態において、第２の部位の曲率半径は、第１の部位の曲率半径よりも大きくなってしまう。言い換えれば、第１の部位の曲率は、第２の部位の曲率よりも大きくなる。 Therefore, in a curved state in which both the first and second parts are curved, the radius of curvature of the second part becomes larger than the radius of curvature of the first part. In other words, the curvature of the first part is larger than the curvature of the second part.

例えば、大腸検査のとき、挿入部を曲がりくねった大腸内で前進させたい場合がある。その場合、小さな曲率の湾曲部（すなわち大きな曲率半径の湾曲部）の状態で挿入部を大腸内に押し込むと、その曲がりくねった大腸が伸展することなく、挿入部を、大腸内で前進させることができる。逆に、大きな曲率の湾曲部（すなわち小さな曲率半径の湾曲部）の状態で挿入部を大腸内に押し込むと、大腸が伸展してしまって、挿入部を、大腸内でスムーズに前進させることが困難な場合がある。 For example, in the case of a large intestine examination, there is a case where it is desired to advance the insertion portion in a winding large intestine. In that case, when the insertion portion is pushed into the large intestine in a state of a curved portion having a small curvature (that is, a curved portion having a large radius of curvature), the insertion portion can be advanced in the large intestine without extending the tortuous colon. it can. Conversely, when the insertion part is pushed into the large intestine with a curved part having a large curvature (that is, a curved part having a small radius of curvature), the large intestine extends and the insertion part can be smoothly advanced in the large intestine. It can be difficult.

従って、上記のように、第２の部位に内側ガイドパイプが挿通されているような内視鏡の場合、第１と第２の部位の両方の部位を湾曲させて、湾曲部全体を湾曲させても、曲率の大きな第１の部位が腸壁を強く押し付けてしまい、大腸が伸展して、挿入部を大腸内で前進させることが困難な場合が生じ得る。
以上のように、１つの湾曲部において湾曲長を変更できるようにしても、第１と第２の部位で曲率あるいは曲率半径が異なると、挿入性の向上が十分に図れないという問題がある。 Therefore, as described above, in the case of an endoscope in which the inner guide pipe is inserted into the second portion, both the first and second portions are bent and the entire bending portion is bent. However, the first portion having a large curvature may strongly press the intestinal wall, and the large intestine may be extended, making it difficult to advance the insertion portion within the large intestine.
As described above, even if the bending length can be changed in one bending portion, there is a problem that the insertability cannot be sufficiently improved if the curvature or the radius of curvature is different between the first and second portions.

そこで、本発明は、上述した問題に鑑みてなされたものであり、１つの湾曲部において湾曲長を変更できる内視鏡において、各湾曲長における各部位の曲率あるいは曲率半径を等しく若しくは略等しくできる内視鏡を提供することを目的とする。 Therefore, the present invention has been made in view of the above-described problems, and in an endoscope that can change the bending length in one bending portion, the curvature or the radius of curvature of each part in each bending length can be made equal or substantially equal. An object is to provide an endoscope.

本発明の一態様によれば、管腔内に挿入可能な挿入部と、前記挿入部の基端側に設けられ、湾曲操作部材を有する操作部と、前記挿入部の先端側に設けられ、前記湾曲操作部材を操作することによって湾曲する湾曲部と、を備え、前記湾曲部の先端側の第１湾曲部分だけが湾曲する第１の状態と、前記第１湾曲部分と前記湾曲部の基端側の第２湾曲部分とが湾曲する第２の状態とを切り替え可能な内視鏡であって、前記湾曲部を覆うように設けられ、弾性を有する円筒状の被覆部材を有し、前記被覆部材は、前記第１湾曲部分を覆う第１の部分と、前記第２湾曲部分を覆う第２の部分とを有し、前記第２の状態において前記第１湾曲部分と前記第２湾曲部分の曲率半径が等しく若しくは略等しくなるように、前記第１の部分と前記第２の部分は、円筒状の薄肉部の厚さにおいて異なり、前記第２の部分の前記薄肉部の厚さは、前記第１の部分の前記薄肉部の厚さより薄い内視鏡を提供することができる。
本発明の一態様によれば、管腔内に挿入可能な挿入部と、前記挿入部の基端側に設けられ、湾曲操作部材を有する操作部と、前記挿入部の先端側に設けられ、前記湾曲操作部材を操作することによって湾曲する湾曲部と、を備え、前記湾曲部の先端側の第１湾曲部分だけが湾曲する第１の状態と、前記第１湾曲部分と前記湾曲部の基端側の第２湾曲部分とが湾曲する第２の状態とを切り替え可能な内視鏡であって、前記湾曲部を覆うように設けられ、弾性を有する円筒状の被覆部材を有し、前記被覆部材は、前記第１湾曲部分を覆う第１の部分と、前記第２湾曲部分を覆う第２の部分とを有し、前記第２の状態において前記第１湾曲部分と前記第２湾曲部分の曲率半径が等しく若しくは略等しくなるように、前記第１の部分と前記第２の部分は、ヤング率において異なり、前記第２の部分のヤング率は、前記第１の部分のヤング率よりも小さい内視鏡を提供することができる。 According to one aspect of the present invention, an insertion portion that can be inserted into a lumen, an operation portion that is provided on a proximal end side of the insertion portion, has a bending operation member, and is provided on a distal end side of the insertion portion, A bending portion that is bent by operating the bending operation member, a first state in which only the first bending portion on the distal end side of the bending portion is bent, and a base of the first bending portion and the bending portion. An endoscope capable of switching between a second state in which the second curved portion on the end side is curved, the endoscope having a cylindrical covering member provided so as to cover the curved portion and having elasticity, The covering member includes a first portion that covers the first curved portion and a second portion that covers the second curved portion, and the first curved portion and the second curved portion in the second state. The first portion and the second portion so that the radii of curvature of the first portion and the second portion are equal. , It varies at a thickness of the cylindrical thin-walled portion, the thickness of the thin portion of the second portion, to provide the first of the thin portion of the thick thin endoscope than of the portions it can.
According to one aspect of the present invention, an insertion portion that can be inserted into a lumen, an operation portion that is provided on a proximal end side of the insertion portion, has a bending operation member, and is provided on a distal end side of the insertion portion, A bending portion that is bent by operating the bending operation member, a first state in which only the first bending portion on the distal end side of the bending portion is bent, and a base of the first bending portion and the bending portion. An endoscope capable of switching between a second state in which the second curved portion on the end side is curved, the endoscope having a cylindrical covering member provided so as to cover the curved portion and having elasticity, The covering member includes a first portion that covers the first curved portion and a second portion that covers the second curved portion, and the first curved portion and the second curved portion in the second state. The first portion and the second portion so that the radii of curvature of the first portion and the second portion are equal. Differ in Young's modulus, the Young's modulus of the second portion can provide the small endoscope than the Young's modulus of the first portion.

本発明によれば、１つの湾曲部において湾曲長を変更できる内視鏡において、各湾曲長における各部位の曲率あるいは曲率半径を等しく若しくは略等しくできる内視鏡を提供することができる。 According to the present invention, it is possible to provide an endoscope that can change the curvature length or the radius of curvature of each part in each bending length in an endoscope that can change the bending length in one bending portion.

本発明の第１の実施の形態に係わる内視鏡の構成を示す構成図である。1 is a configuration diagram showing a configuration of an endoscope according to a first embodiment of the present invention. 本発明の第１の実施の形態に係わる挿入部２の湾曲部７の断面図である。It is sectional drawing of the curved part 7 of the insertion part 2 concerning the 1st Embodiment of this invention. 本発明の第１の実施の形態に係わる湾曲部７の先端側の部分断面図である。It is a fragmentary sectional view by the side of the tip of curved part 7 concerning a 1st embodiment of the present invention. 本発明の第１の実施の形態に係わる湾曲部７の基端側の部分断面図である。It is a fragmentary sectional view by the side of the base end of the curved part 7 concerning the 1st Embodiment of this invention. 本発明の第１の実施の形態に係わる湾曲部７の中央部分の部分断面図である。It is a fragmentary sectional view of the center part of the curved part 7 concerning the 1st Embodiment of this invention. 本発明の第１の実施の形態に係わる、湾曲部７の第１湾曲部７ａと第２湾曲部７ｂが湾曲した状態を模式的かつ概略的に説明するための図である。It is a figure for explaining typically and roughly the state where the 1st bending part 7a and the 2nd bending part 7b of bending part 7 concerning the 1st embodiment of the present invention curved. 本発明の第１の実施の形態に係わる、湾曲部７の第１湾曲部７ａのみが湾曲した状態を模式的かつ概略的に説明するための図である。It is a figure for explaining typically and roughly the state where only the 1st bending part 7a of bending part 7 concerning the 1st embodiment of the present invention curved. 本発明の第１の実施の形態に係わる被覆部材２１の構成を説明するための模式的な断面図である。It is typical sectional drawing for demonstrating the structure of the coating | coated member 21 concerning the 1st Embodiment of this invention. 従来の内視鏡の湾曲状態を模式的かつ概略的に説明するための図である。It is a figure for demonstrating typically and roughly the curve state of the conventional endoscope. 本発明の第２の実施の形態に係わる被覆部材７１の構成を説明するための模式的な断面図である。It is typical sectional drawing for demonstrating the structure of the coating | coated member 71 concerning the 2nd Embodiment of this invention. 本発明の第２の実施の形態に係わる、被覆部材７１の外周面に施す表面コート処理を説明するための図である。It is a figure for demonstrating the surface coat process performed to the outer peripheral surface of the coating | coated member 71 concerning the 2nd Embodiment of this invention. 本発明の変形例２に係る、湾曲部７の第１湾曲部７ａと第２湾曲部７ｂの外径が異なる場合における被覆部材８１の構成を説明するための模式的な断面図である。It is typical sectional drawing for demonstrating the structure of the coating | coated member 81 in case the outer diameters of the 1st bending part 7a and the 2nd bending part 7b of the bending part 7 which concern on the modification 2 of this invention differ.

以下、図面を参照して本発明の実施の形態を説明する。
なお、以下の説明に用いる各図においては、各構成要素を図面上で認識可能な程度の大きさとするため、各構成要素毎に縮尺を異ならせてあるものであり、本発明は、これらの図に記載された構成要素の数量、構成要素の形状、構成要素の大きさの比率、及び各構成要素の相対的な位置関係のみに限定されるものではない。
（第１の実施の形態）
図１は、本実施の形態に係わる内視鏡の構成を示す構成図である。図１に示すように、内視鏡１は、管腔内に挿入可能な挿入部２と、挿入部の基端側に連設された操作部３と、操作部３の側部から延設されたユニバーサルコード４と、ユニバーサルコード４の延出端に設けられたコネクタ５とを有して構成されている。 Embodiments of the present invention will be described below with reference to the drawings.
In each drawing used for the following description, the scale is different for each component in order to make each component large enough to be recognized on the drawing. It is not limited only to the quantity of the component described in the drawing, the shape of the component, the ratio of the size of the component, and the relative positional relationship of each component.
(First embodiment)
FIG. 1 is a configuration diagram showing a configuration of an endoscope according to the present embodiment. As shown in FIG. 1, an endoscope 1 includes an insertion portion 2 that can be inserted into a lumen, an operation portion 3 that is connected to the proximal end side of the insertion portion, and a side portion of the operation portion 3. The universal cord 4 and the connector 5 provided at the extended end of the universal cord 4 are configured.

挿入部２は、先端部６と、先端部６の基端側に連設された湾曲部７、及び湾曲部７の基端側に連設された可撓管部８とを有する。湾曲部７は、先端側に第１湾曲部７ａを、基端側に第２湾曲部７ｂを有して構成されている。 The insertion portion 2 includes a distal end portion 6, a bending portion 7 provided continuously with the proximal end side of the distal end portion 6, and a flexible tube portion 8 provided continuously with the proximal end side of the bending portion 7. The bending portion 7 has a first bending portion 7a on the distal end side and a second bending portion 7b on the proximal end side.

操作部３は、挿入部２の基端側に設けられ、湾曲操作部材を有する。具体的には、操作部３は、術者が内視鏡１を把持するためのグリップ部９と、湾曲操作部材としての湾曲操作ノブ１０ａ、１０ｂ、湾曲範囲切り換え部材としての湾曲範囲切り換えレバー１１とを有する。湾曲操作ノブ１０ａは、湾曲部７を上下方向に湾曲させるために湾曲操作部材あり、湾曲操作ノブ１０ｂは、湾曲部７を左右方向に湾曲させるための湾曲操作部材である。
よって、湾曲部７は、挿入部２の先端側に設けられ、湾曲操作部材である湾曲操作ノブ１０ａ、１０ｂが操作されることによって湾曲する。 The operation unit 3 is provided on the proximal end side of the insertion unit 2 and has a bending operation member. Specifically, the operation unit 3 includes a grip unit 9 for an operator to hold the endoscope 1, bending operation knobs 10a and 10b as bending operation members, and a bending range switching lever 11 as a bending range switching member. And have. The bending operation knob 10a is a bending operation member for bending the bending portion 7 in the vertical direction, and the bending operation knob 10b is a bending operation member for bending the bending portion 7 in the left-right direction.
Therefore, the bending portion 7 is provided on the distal end side of the insertion portion 2, and is bent when the bending operation knobs 10a and 10b which are bending operation members are operated.

コネクタ５は、内視鏡１を光源装置（図示せず）とビデオプロセッサ（図示せず）に接続するためのコネクタである。光源装置からの照明光は、ユニバーサルコード４及び操作部３及び挿入部２内に挿通された光ファイバを通して、先端部６から出射される。照明光により照射された被写体からの反射光が、先端部６の観察窓を介して撮像素子（図示せず）により受光され、撮像素子からの映像信号は、挿入部２、操作部３及びユニバーサルコード４内に挿通された信号線を介して、ビデオプロセッサに供給される。 The connector 5 is a connector for connecting the endoscope 1 to a light source device (not shown) and a video processor (not shown). Illumination light from the light source device is emitted from the distal end portion 6 through the optical fiber inserted into the universal cord 4, the operation unit 3, and the insertion unit 2. Reflected light from the object irradiated by the illumination light is received by an image sensor (not shown) through the observation window of the tip 6, and a video signal from the image sensor is the insertion unit 2, the operation unit 3, and the universal signal. The signal is supplied to the video processor through a signal line inserted into the code 4.

術者は、操作部３に設けられた湾曲操作ノブ１０ａ、１０ｂを操作することによって、湾曲部７を所望の方向へ所望の量だけ湾曲させることができる。また、術者は、湾曲範囲切り換えレバー１１を操作することによって、湾曲部７の先端側の湾曲部７ａのみを湾曲させるか、第１湾曲部７ａと第２湾曲部７ｂの両方を湾曲させるかを選択できる。
よって、内視鏡１は、湾曲部７の先端側の第１湾曲部分である第１湾曲部７ａだけが湾曲する第１の状態と、第１湾曲部７ａと湾曲部７の基端側の第２湾曲部分である第２湾曲部７ｂとが湾曲する第２の状態とを切り替え可能な内視鏡である。 The surgeon can bend the bending portion 7 in a desired direction by a desired amount by operating the bending operation knobs 10 a and 10 b provided in the operation portion 3. Whether the surgeon bends only the bending portion 7a on the distal end side of the bending portion 7 or bends both the first bending portion 7a and the second bending portion 7b by operating the bending range switching lever 11. Can be selected.
Therefore, the endoscope 1 is in a first state in which only the first bending portion 7a that is the first bending portion on the distal end side of the bending portion 7 is bent, and on the proximal end side of the first bending portion 7a and the bending portion 7. This is an endoscope that can switch between a second state in which the second bending portion 7b that is the second bending portion is bent.

図２〜図５は、湾曲部７の構成を説明するための図である。図２は、挿入部２の湾曲部７の断面図である。図３は、湾曲部７の先端側の部分断面図であり、図４は、湾曲部７の基端側の部分断面図であり、図５は、湾曲部７の中央部分の部分断面図である。 2-5 is a figure for demonstrating the structure of the bending part 7. FIG. FIG. 2 is a cross-sectional view of the bending portion 7 of the insertion portion 2. 3 is a partial sectional view of the bending portion 7 on the distal end side, FIG. 4 is a partial sectional view of the bending portion 7 on the proximal end side, and FIG. 5 is a partial sectional view of the central portion of the bending portion 7. is there.

図２に示すように、湾曲部７の内部には、複数の湾曲駒７ｃが、挿入方向Ｓに沿って連結されて設けられている。また、複数の湾曲駒７ｃの外周に、ブレード７ｄが被覆されており、該ブレード７ｄの外周に、被覆部材２１が被覆されている。
被覆部材２１は、湾曲部７を覆うように設けられ、弾性を有する円筒状の部材である。 As shown in FIG. 2, a plurality of bending pieces 7 c are connected and provided along the insertion direction S in the bending portion 7. Further, the outer periphery of the plurality of bending pieces 7c is covered with a blade 7d, and the outer periphery of the blade 7d is covered with a covering member 21.
The covering member 21 is a cylindrical member that is provided so as to cover the curved portion 7 and has elasticity.

上述したように、湾曲部７の内、挿入方向Ｓにおける前半部に位置する部位が、第１湾曲部７ａであり、挿入方向Ｓにおける後半部に位置する部位が、第２湾曲部７ｂである。
操作部３及び挿入部２内には、湾曲部７の湾曲状態を変更するための、複数のワイヤ、ここでは４本のワイヤ３０が挿通されている。具体的には、挿入方向Ｓの前後方向に移動自在な４本のワイヤ３０が互いに挿入部２の円周方向に略９０°ずれて挿通されており、第１湾曲部７ａに位置する複数の湾曲駒７ｃには、４本のワイヤ３０を保持するワイヤガイド（図示せず）がそれぞれ設けられている。
また、湾曲部７の先端側は、先端部６の金属製の先端硬質部材６ａに固定されており、先端硬質部材６ａには、樹脂製の先端キャップ６ｂが被せられている。
各ワイヤ３０の先端は、複数の湾曲駒７ｃの内、挿入方向Ｓの最も先端側に位置する湾曲駒７ｃに対し固定されている。 As described above, the portion located in the first half in the insertion direction S in the bending portion 7 is the first bending portion 7a, and the portion located in the second half in the insertion direction S is the second bending portion 7b. .
In the operation unit 3 and the insertion unit 2, a plurality of wires, here, four wires 30 for changing the bending state of the bending unit 7 are inserted. Specifically, four wires 30 that are movable in the front-rear direction of the insertion direction S are inserted so as to be shifted from each other by approximately 90 ° in the circumferential direction of the insertion portion 2, so The bending pieces 7c are provided with wire guides (not shown) for holding the four wires 30, respectively.
Further, the distal end side of the bending portion 7 is fixed to a metal distal end hard member 6a of the distal end portion 6, and the distal end hard member 6a is covered with a resin distal end cap 6b.
The tip of each wire 30 is fixed to the bending piece 7c located on the most distal end side in the insertion direction S among the plurality of bending pieces 7c.

さらに、上下湾曲用の２本のワイヤ３０の各基端は、上下湾曲用の湾曲操作ノブ１０ａに連結された図示しないスプロケットに巻回され、左右湾曲用の２本のワイヤ３０の各基端は、湾曲操作ノブ１０ａに連結されたスプロケットとは別の左右湾曲用の湾曲操作ノブ１０ｂに連結された図示しないスプロケットに巻回されている。 Further, the base ends of the two wires 30 for bending up and down are wound around a sprocket (not shown) connected to the bending operation knob 10a for bending up and down, and the base ends of the two wires 30 for bending left and right are provided. Is wound around a sprocket (not shown) connected to a bending operation knob 10b for bending left and right different from the sprocket connected to the bending operation knob 10a.

即ち、上下湾曲用の湾曲操作ノブ１０ａが操作されると、２本の上下用のワイヤ３０は、一方が挿入方向Ｓの後方に移動され、他方が挿入方向Ｓの前方に移動される、即ち、一方が牽引され他方が弛緩されることにより、湾曲部７は上下方向いずれかに湾曲する。 That is, when the up / down bending operation knob 10a is operated, one of the two up / down wires 30 is moved rearward in the insertion direction S, and the other is moved forward in the insertion direction S. When one is pulled and the other is relaxed, the bending portion 7 bends in one of the vertical directions.

また、左右湾曲用の湾曲操作ノブ１０ｂが操作されると、２本の左右用のワイヤ３０は、一方が後方に移動され、他方が前方に移動される、即ち、一方が牽引され他方が弛緩されることにより、湾曲部７は左右方向いずれかに湾曲する。 When the bending operation knob 10b for left / right bending is operated, one of the two left / right wires 30 is moved backward and the other is moved forward, that is, one is pulled and the other is relaxed. As a result, the bending portion 7 is bent in either the left-right direction.

また、第２湾曲部７ｂにおいて、複数の湾曲駒７ｃの内、最も基端側に位置する湾曲駒７ｃには、連結部材３１の先端部が固定されており、連結部材３１の基端部の内周には可撓管部８を構成する内層８ｂの先端部が固定されていて、内層８ｂの外周には、外皮チューブ８ｃが被覆されている。最も基端側の湾曲駒７ｃと連結部材３１との固定はビスにより、連結部材３１と内層８ｂとの固定は接着剤によりそれぞれ行われる。 Further, in the second bending portion 7 b, the distal end portion of the connecting member 31 is fixed to the bending piece 7 c located closest to the proximal end among the plurality of bending pieces 7 c, and the proximal end portion of the connecting member 31 is fixed. The tip of the inner layer 8b constituting the flexible tube portion 8 is fixed to the inner periphery, and the outer tube 8c is covered on the outer periphery of the inner layer 8b. The bending piece 7c on the most proximal side and the connecting member 31 are fixed by screws, and the connecting member 31 and the inner layer 8b are fixed by adhesive.

また、操作部３、挿入部２内に挿通された４本のワイヤ３０のそれぞれの外周は、例えば柔軟であって挿入方向Ｓに沿って細長なコイルパイプから構成された、湾曲部７の湾曲状態を切り換えるための移動部材である内側ガイドシース４０によって被覆されている。 In addition, the outer periphery of each of the four wires 30 inserted into the operation unit 3 and the insertion unit 2 is, for example, flexible and curved of the bending unit 7 formed of a long and narrow coil pipe along the insertion direction S. It is covered with an inner guide sheath 40 which is a moving member for switching the state.

即ち、操作部３、挿入部２内においては、各内側ガイドシース４０は、挿入部４の円周方向においてずれた位置に４本挿通されている。尚、各内側ガイドシース４０は、例えばステンレスのコイルパイプから形成されている。そして、各内側ガイドシース４０内において、各ワイヤ３０は、前後に移動自在となっている。 That is, in the operation unit 3 and the insertion unit 2, four inner guide sheaths 40 are inserted at positions shifted in the circumferential direction of the insertion unit 4. Each inner guide sheath 40 is formed of, for example, a stainless steel coil pipe. In each inner guide sheath 40, each wire 30 is movable back and forth.

さらに、各内側ガイドシース４０が柔軟なコイルパイプから構成されているのは、例えば通常の金属製の硬質なパイプを各ワイヤ３０の外周に被覆してしまうと、湾曲部７が湾曲しなくなってしまうばかりか、可撓管部８の可撓性が低下してしまうためである。 Further, each inner guide sheath 40 is formed of a flexible coil pipe. For example, if the outer periphery of each wire 30 is covered with a normal metal hard pipe, the bending portion 7 is not bent. This is because the flexibility of the flexible tube portion 8 is lowered.

よって、各内側ガイドシース４０は、湾曲部７の湾曲性及び可撓管部８の可撓性を低下させないものであって、湾曲部７の湾曲の際、各内側ガイドシース４０の延在方向に沿って働く圧縮力に抗することができるものであれば、各内側ガイドシース４０を構成する部材は、コイルパイプに限定されない。 Therefore, each inner guide sheath 40 does not deteriorate the bending property of the bending portion 7 and the flexibility of the flexible tube portion 8, and the extending direction of each inner guide sheath 40 when the bending portion 7 is bent. The members constituting each inner guide sheath 40 are not limited to the coil pipes as long as they can resist the compressive force acting along the guide lines.

また、図２及び図５に示すように、各内側ガイドシース４０の先端部４０ｓは、湾曲部７の挿入方向Ｓにおける中途位置、例えば、第２湾曲部７ｂの先端位置の湾曲駒７ｃに対して、例えばロウ付けにより固定されている。 Further, as shown in FIGS. 2 and 5, the distal end portion 40s of each inner guide sheath 40 is located at an intermediate position in the insertion direction S of the bending portion 7, for example, the bending piece 7c at the distal end position of the second bending portion 7b. For example, it is fixed by brazing.

尚、内視鏡１は、湾曲操作切り換えレバー１１により、操作部３内に設けられた移動部材固定機構３ａ（図６）において各内側ガイドシース４０の基端部４０ｋが固定状態と非固定状態とが切り換え可能となるように、構成されている。即ち、移動部材固定機構３ａは、各内側ガイドシース４０が挿入方向Ｓに沿って移動しないように、各内側ガイドシース４０を固定する機構である。
尚、移動部材固定機構３ａの構造については、例えば、特許第４８５６２８９号公報を参照されたし。 In the endoscope 1, the proximal end portion 40 k of each inner guide sheath 40 is in a fixed state and a non-fixed state in the moving member fixing mechanism 3 a (FIG. 6) provided in the operation unit 3 by the bending operation switching lever 11. Are configured to be switchable. That is, the moving member fixing mechanism 3a is a mechanism that fixes each inner guide sheath 40 so that each inner guide sheath 40 does not move along the insertion direction S.
For the structure of the moving member fixing mechanism 3a, see, for example, Japanese Patent No. 4856289.

さらに、図２に示すように、可撓管部８内に位置する４本の内側ガイドシース４０のそれぞれの外周は、例えば柔軟なコイルパイプから構成された外側ガイドシース５０によって被覆されている。尚、各外側ガイドシース５０内に挿通されている各内側ガイドシース４０は、挿入方向Ｓに対して進退自在となっている。また、各外側ガイドシース５０も、例えばステンレスのコイルパイプから形成されている。 Further, as shown in FIG. 2, the outer circumferences of the four inner guide sheaths 40 positioned in the flexible tube portion 8 are covered with an outer guide sheath 50 made of, for example, a flexible coil pipe. The inner guide sheaths 40 inserted into the outer guide sheaths 50 can move forward and backward in the insertion direction S. Each outer guide sheath 50 is also formed of, for example, a stainless steel coil pipe.

よって、各外側ガイドシース５０は、可撓管部８の可撓性を低下させないものであって、湾曲部７の湾曲の際、各外側ガイドシース５０の延在方向に働く圧縮力に抗することができるものであれば、各外側ガイドシース５０を構成する部材は、コイルパイプに限定されない。 Therefore, each outer guide sheath 50 does not reduce the flexibility of the flexible tube portion 8, and resists the compressive force acting in the extending direction of each outer guide sheath 50 when the bending portion 7 is bent. If possible, the members constituting each outer guide sheath 50 are not limited to coil pipes.

また、図２及び図４に示すように、連結部材３１の先端部が、湾曲部７の基端側の最終湾曲駒７ｃの肩口端部に固定され、連結部材３１の基端部は、内層８ｂの先端部に固定され、連結部材３１の先端部には各外側ガイドシース５０の先端部５０ｓが固定されている。よって、湾曲部７の基端側の最終湾曲駒７ｃの肩口端部よりも先端側の部分が、湾曲部として湾曲する。
各外側ガイドシース５０の先端部５０ｓは、可撓管部８の先端、具体的には、連結部材３１に対して、例えばロウ付けによって固定されている。
なお、各外側ガイドシース５０の基端部５０ｋは、可撓管部８よりも後方に位置する止め部材（図示せず）に対して、例えばロウ付けにより固定されている。 2 and 4, the distal end portion of the connecting member 31 is fixed to the shoulder end portion of the final bending piece 7c on the proximal end side of the bending portion 7, and the proximal end portion of the connecting member 31 is the inner layer. The distal end portion 50s of each outer guide sheath 50 is fixed to the distal end portion of the connecting member 31. Therefore, a portion of the distal end side of the end portion of the final bending piece 7c on the proximal end side of the bending portion 7 is curved as a bending portion.
The distal end portion 50 s of each outer guide sheath 50 is fixed to the distal end of the flexible tube portion 8, specifically, the connecting member 31 by brazing, for example.
In addition, the base end part 50k of each outer side guide sheath 50 is being fixed with brazing, for example with respect to the stop member (not shown) located behind the flexible tube part 8. FIG.

すなわち、可撓管部８内に、先端部５０ｓ及び基端部５０ｋが固定された状態において各外側ガイドシース５０が挿通されていることにより、４本のワイヤ３０の内、いずれかが牽引されて湾曲部７を湾曲させる際、各外側ガイドシース５０が該外側ガイドシース５０の延在方向に沿って可撓管部８に働く圧縮力に抗する。これにより、可撓性を有する可撓管部８までもが、湾曲部７とともに湾曲してしまうことが防止されている。 That is, each of the four wires 30 is pulled by inserting each outer guide sheath 50 into the flexible tube portion 8 in a state where the distal end portion 50s and the proximal end portion 50k are fixed. When the bending portion 7 is bent, each outer guide sheath 50 resists the compressive force acting on the flexible tube portion 8 along the extending direction of the outer guide sheath 50. Thereby, even the flexible tube portion 8 having flexibility is prevented from being bent together with the bending portion 7.

尚、各外側ガイドシース５０の先端部５０ｓと基端部５０ｋとが固定された状態において、各内側ガイドシース４０の先端部４０ｓは、第２湾曲部７ｂの先端に固定されている。そして、各内側ガイドシース４０は、各内側ガイドシース４０の基端部４０ｋが各外側ガイドシース５０の基端部５０ｋよりも先端側に引き込まれない長さを有している。 In addition, in the state where the distal end portion 50s and the proximal end portion 50k of each outer guide sheath 50 are fixed, the distal end portion 40s of each inner guide sheath 40 is fixed to the distal end of the second bending portion 7b. Each inner guide sheath 40 has such a length that the proximal end portion 40k of each inner guide sheath 40 is not drawn to the distal end side than the proximal end portion 50k of each outer guide sheath 50.

また、被覆部材２１が湾曲部７に装着される前の状態では、筒状の被覆部材２１の内径は、ブレード７ｄを含む湾曲部７の外径よりもわずかに小さい。そのため、筒状の被覆部材２１は、治具を用いて拡径された状態で、湾曲部７に装着され、装着されると、湾曲部７の外周面に密着する。そして、湾曲部７を覆う被覆部材２１の先端部と基端部は、それぞれ、糸が巻かれさらにその糸が巻かれた部分に接着剤が塗布された固定部６０により、先端部６と可撓管部８に対して固定されている。 In addition, before the covering member 21 is attached to the bending portion 7, the inner diameter of the cylindrical covering member 21 is slightly smaller than the outer diameter of the bending portion 7 including the blade 7d. Therefore, the cylindrical covering member 21 is attached to the bending portion 7 in a state where the diameter is expanded using a jig, and when attached, the cylindrical covering member 21 is in close contact with the outer peripheral surface of the bending portion 7. Then, the distal end portion and the proximal end portion of the covering member 21 covering the curved portion 7 are allowed to be connected to the distal end portion 6 by a fixing portion 60 in which a thread is wound and an adhesive is applied to a portion where the thread is wound. It is fixed with respect to the flexible tube portion 8.

湾曲部７に装着された被覆部材２１において、内側ガイドシース４０の先端部４０ｓの位置Ｍよりも先端側の部分が第１の部位２１ａであり、内側ガイドシース４０の先端部４０ｓの位置Ｍよりも基端側の部分が第２の部位２１ｂである。 In the covering member 21 attached to the bending portion 7, a portion closer to the distal end than the position M of the distal end portion 40 s of the inner guide sheath 40 is the first portion 21 a, and from the position M of the distal end portion 40 s of the inner guide sheath 40. Also, the proximal end portion is the second portion 21b.

後述するように、円筒状の第１の部位２１ａの薄肉部の厚さは、第２の部位２１ｂの薄肉部の厚さよりも厚くなっており、第１の部位２１ａは、第２の部位２１ｂよりも曲がり難くなっている。すなわち、第１の部分２１ａと第２の部分２１ｂが円筒状の薄肉部の厚さにおいて異なっており、第２の部分２１ｂの薄肉部の厚さは、第１の部分２１ａの薄肉部の厚さより薄い。 As will be described later, the thickness of the thin portion of the cylindrical first portion 21a is thicker than the thickness of the thin portion of the second portion 21b, and the first portion 21a is the second portion 21b. It is harder to bend than. That is, the first portion 21a and the second portion 21b are different in the thickness of the cylindrical thin portion, and the thickness of the thin portion of the second portion 21b is the thickness of the thin portion of the first portion 21a. Thinner than that.

次に、図６及び図７を用いて湾曲部７の湾曲動作について説明する。図６は、湾曲部７の第１湾曲部７ａと第２湾曲部７ｂが湾曲した状態を模式的かつ概略的に説明するための図、図７は、湾曲部７の第１湾曲部７ａのみが湾曲した状態を模式的かつ概略的に説明するための図である。 Next, the bending operation of the bending portion 7 will be described with reference to FIGS. 6 is a diagram for schematically and schematically illustrating a state in which the first bending portion 7a and the second bending portion 7b of the bending portion 7 are bent, and FIG. 7 illustrates only the first bending portion 7a of the bending portion 7. It is a figure for demonstrating typically and roughly the state which curved.

先ず、図６に示すように、湾曲部７を第２湾曲部７ｂの基端側から湾曲させたい場合は、即ち、湾曲部７全体を湾曲させたい場合は、操作者は、湾曲範囲切り換えレバー１１の操作を行わず、移動部材固定機構３ａを用いた各内側ガイドシース４０の基端部４０ｋの固定を解除しておく。図６は、湾曲部７の湾曲長が長い長湾曲状態を示す。 First, as shown in FIG. 6, when the bending portion 7 is to be bent from the proximal end side of the second bending portion 7b, that is, when the entire bending portion 7 is to be bent, the operator selects the bending range switching lever. 11 is not performed, and the fixing of the base end portion 40k of each inner guide sheath 40 using the moving member fixing mechanism 3a is released. FIG. 6 shows a long bending state in which the bending portion 7 has a long bending length.

この長湾曲状態において、操作者は、上下湾曲用の湾曲操作ノブ１０ａ及び左右湾曲用の湾曲操作ノブ１０ｂのいずれかを操作して、４本のワイヤ３０の内、いずれかのワイヤ３０を牽引すると、各内側ガイドシース４０は、基端部４０ｋが固定されていないことから、湾曲部７の第２湾曲部７ｂにおいて各内側ガイドシース４０の延在方向に沿って作用する圧縮力に抗することができず、基端部４０ｋが後方に移動する。 In this long bending state, the operator operates one of the bending operation knob 10a for up / down bending and the bending operation knob 10b for left / right bending, and pulls one of the four wires 30. Then, each inner guide sheath 40 resists the compressive force acting along the extending direction of each inner guide sheath 40 in the second bending portion 7b of the bending portion 7 because the base end portion 40k is not fixed. The base end portion 40k moves backward.

また、可撓管部８内においては、各外側ガイドシース５０は、先端部５０ｓと基端部５０ｋとが固定されていることから、各外側ガイドシース５０は、各外側ガイドシース５０の延在方向に沿って作用する圧縮力に抗する。 In the flexible tube portion 8, each outer guide sheath 50 has a distal end portion 50 s and a base end portion 50 k fixed to each other, and thus each outer guide sheath 50 extends from each outer guide sheath 50. Resists compressive forces acting along the direction.

その結果、図６に示すように、湾曲部７は、各外側ガイドシース５０の先端部５０ｓを起点として、第２湾曲部７ｂの基端側から、第１湾曲部７ａ及び第２湾曲部７ｂが湾曲する。即ち、湾曲部７全体が湾曲する。 As a result, as shown in FIG. 6, the bending portion 7 starts from the distal end portion 50 s of each outer guide sheath 50 from the proximal end side of the second bending portion 7 b, and the first bending portion 7 a and the second bending portion 7 b. Is curved. That is, the entire bending portion 7 is bent.

次に、湾曲部７において、第１湾曲部７ａだけを湾曲させたい場合には、操作者は、湾曲範囲切り換えレバー１１の操作を行って、移動部材固定機構３ａを用いて各内側ガイドシース４０の基端部４０ｋを固定する。図７では、各内側ガイドシース４０の基端部４０ｋを固定するパイプ止め部材３ｂが、移動部材固定機構３ａ内において移動部材（図示せず）により押圧されることによって、各内側ガイドシース４０の基端部４０ｋは固定される。図７は、湾曲部７の湾曲長が短い短湾曲状態を示す。 Next, when it is desired to bend only the first bending portion 7a in the bending portion 7, the operator operates the bending range switching lever 11 and uses the moving member fixing mechanism 3a to each inner guide sheath 40. The base end portion 40k of is fixed. In FIG. 7, the pipe fixing member 3 b that fixes the proximal end portion 40 k of each inner guide sheath 40 is pressed by a moving member (not shown) in the moving member fixing mechanism 3 a, thereby causing each inner guide sheath 40 to move. The base end portion 40k is fixed. FIG. 7 shows a short bending state in which the bending length of the bending portion 7 is short.

この短湾曲状態において、操作者は、上下湾曲用の湾曲操作ノブ１０ａ及び左右湾曲用の湾曲操作ノブ１０ｂのいずれかを操作して、４本のワイヤ３０の内、いずれかのワイヤ３０を牽引すると、各内側ガイドシース４０は基端部４０ｋが固定されていることから、湾曲部７の第２湾曲部７ｂにおいて各内側ガイドシース４０の延在方向に沿って作用する圧縮力に抗する。 In this short bending state, the operator operates one of the bending operation knob 10a for up / down bending and the bending operation knob 10b for left / right bending, and pulls one of the four wires 30. Then, since the base end portion 40k is fixed to each inner guide sheath 40, the inner guide sheath 40 resists a compressive force acting along the extending direction of each inner guide sheath 40 in the second bending portion 7b of the bending portion 7.

その結果、図７に示すように、湾曲部７は、各内側ガイドシース４０の先端部４０ｓを起点として、第１湾曲部７ａの基端側から、第１湾曲部７ａが湾曲する。即ち、湾曲部７の第１湾曲部７ａのみが湾曲する。 As a result, as shown in FIG. 7, in the bending portion 7, the first bending portion 7 a is bent from the proximal end side of the first bending portion 7 a starting from the distal end portion 40 s of each inner guide sheath 40. That is, only the first bending portion 7a of the bending portion 7 is bent.

以上により、各内側ガイドシース４０の基端部４０ｋの固定、非固定を切り換えることにより、湾曲部７の湾曲状態を切り替えすなわち湾曲部７の湾曲長を変更することができる。 As described above, by switching between fixing and non-fixing of the base end portion 40k of each inner guide sheath 40, the bending state of the bending portion 7 can be switched, that is, the bending length of the bending portion 7 can be changed.

湾曲部７には、被覆部材２１が被覆されている。
図８は、被覆部材２１の構成を説明するための模式的な断面図である。被覆部材２１は、弾性を有する部材であり、例えば、フッ素ゴム、ウレタンゴム、ウレタン系エラストマー等からなる。 The bending portion 7 is covered with a covering member 21.
FIG. 8 is a schematic cross-sectional view for explaining the configuration of the covering member 21. The covering member 21 is a member having elasticity, and is made of, for example, fluorine rubber, urethane rubber, urethane elastomer, or the like.

図８に示すように、被覆部材２１は、湾曲部７全体を被覆するような長さを有する筒状部材である。被覆部材２１は、第１湾曲部７ａを覆う第１の部分２１ａと、第２湾曲部７ｂを覆う第２の部分２１ｂとを有する。図８に示すように、第１の部分２１ａの薄肉部の厚さｄ１は、第２の部分２１ｂの薄肉部の厚さｄ２よりも厚い。すなわち、被覆部材２１は、第２の部分２１ｂよりも肉厚な第１の部分２１ａを有する円筒状部材である。 As shown in FIG. 8, the covering member 21 is a cylindrical member having a length that covers the entire bending portion 7. The covering member 21 includes a first portion 21a that covers the first curved portion 7a and a second portion 21b that covers the second curved portion 7b. As shown in FIG. 8, the thickness d1 of the thin portion of the first portion 21a is thicker than the thickness d2 of the thin portion of the second portion 21b. That is, the covering member 21 is a cylindrical member having a first portion 21a that is thicker than the second portion 21b.

被覆部材２１は、弾性を有するので、応力が掛かると曲がるが、第１の部分２１ａは、第２の部分２１ｂよりも、薄肉部の厚さが厚いため、曲がり難い。逆に、第２の部分２１ｂは、第１の部分２１ａよりも、薄肉部の厚さが薄いため、曲がり易い。 Since the covering member 21 has elasticity, it bends when stress is applied, but the first portion 21a is less likely to bend because the thickness of the thin portion is larger than that of the second portion 21b. On the contrary, the second portion 21b is easier to bend because the thickness of the thin portion is smaller than that of the first portion 21a.

湾曲部７の第１湾曲部７ａの曲がり易さと、被覆部材２１の第１の部分２１ａの曲がり難さとが相殺され、さらに内蔵物である４つの内側ガイドシース４０が内蔵された湾曲部７の第２湾曲部７ｂの曲がり難さと、被覆部材２１の第２の部分２１ｂの曲がり易さとが相殺され、湾曲部７は、全体として、図６に示すように、同じ若しくは略同じ曲率半径で湾曲するように、被覆部材２１は、第１の部分２１ａの厚さｄ１と第２の部分２１ｂの厚さｄ２を有する。言い換えると、被覆部材２１により、第１湾曲部７ａと第２湾曲部７ｂの湾曲し易さの差が可能な限り低減されて、湾曲部７は、全体として、図６に示すように、同じ若しくは略同じ曲率半径で湾曲する。 The bendability of the first bending portion 7a of the bending portion 7 and the difficulty of bending of the first portion 21a of the covering member 21 are offset, and furthermore, the bending portion 7 in which the four inner guide sheaths 40 that are built-in objects are incorporated. The difficulty in bending of the second bending portion 7b and the ease of bending of the second portion 21b of the covering member 21 are offset, and the bending portion 7 is bent with the same or substantially the same radius of curvature as shown in FIG. As described above, the covering member 21 has a thickness d1 of the first portion 21a and a thickness d2 of the second portion 21b. In other words, the covering member 21 reduces the difference in easiness of bending between the first bending portion 7a and the second bending portion 7b as much as possible, and the bending portion 7 as a whole is the same as shown in FIG. Or it curves with substantially the same radius of curvature.

発明者の実験によれば、内視鏡の挿入部２の直径が、１２ｍｍで、内側ガイドシース４０の材質がステンレス（SUS）製で、太さ（直径）が１．３ｍｍのときに、第１の部分２１ａの薄肉部の厚さｄ１に対する第２の部分２１ｂの薄肉部の厚さｄ２の比率（ｄ２／ｄ１）は、０．６〜０．８が好ましい。すなわち、第２の部分２１ｂの薄肉部の厚さは、第１の部分２１ａの薄肉部の厚さの０．６〜０．８倍であることが好ましい。

特に、２つの厚さの比率（ｄ２／ｄ１）は、０．６５〜０．７５が好ましい。例えば、被覆部材２１の第１の部分２１ａの厚さｄ１が０．７ｍｍで、第２の部分２１ｂの厚さｄ２が０．５ｍｍであるときに、湾曲部７は、全体として、図６に示すように、同じ若しくは略同じ曲率半径で湾曲した。 According to the inventor's experiment, when the diameter of the insertion portion 2 of the endoscope is 12 mm, the inner guide sheath 40 is made of stainless steel (SUS), and the thickness (diameter) is 1.3 mm, The ratio (d2 / d1) of the thickness d2 of the thin portion of the second portion 21b to the thickness d1 of the thin portion of the first portion 21a is preferably 0.6 to 0.8. That is, the thickness of the thin portion of the second portion 21b is preferably 0.6 to 0.8 times the thickness of the thin portion of the first portion 21a.

In particular, the ratio of the two thicknesses (d2 / d1) is preferably 0.65 to 0.75. For example, when the thickness d1 of the first portion 21a of the covering member 21 is 0.7 mm and the thickness d2 of the second portion 21b is 0.5 mm, the bending portion 7 as a whole is shown in FIG. As shown, it was curved with the same or substantially the same radius of curvature.

もしも、第１の部分２１ａが第２の部分２１ｂよりも肉厚でなく、第１の部分２１ａが曲がり難くないと、例えば、図９に示すように、湾曲部７全体を湾曲させた場合に、湾曲部７の第１湾曲部７ａと、第２湾曲部７ｂの曲率半径は、異なる状態が生じる。 If the first portion 21a is not thicker than the second portion 21b and the first portion 21a is not easily bent, for example, when the entire bending portion 7 is bent as shown in FIG. The first and second bending portions 7a and 7b of the bending portion 7 have different radii of curvature.

図９は、従来の内視鏡の湾曲状態を模式的かつ概略的に説明するための図である。湾曲部７の第２湾曲部７ｂには、第１湾曲部７ａには無い内蔵物（例えば内側ガイドシース）が内蔵されているため、第２湾曲部７ｂは、第１湾曲部７ａに比べて曲がり難い。そのため、第２湾曲部７ｂの曲率半径は、第１湾曲部７ａの曲率半径よりも大きくなってしまう。言い換えれば、第１湾曲部７ａの曲率は、第２湾曲部７ｂの曲率よりも大きくなってしまう。 FIG. 9 is a diagram for schematically and schematically explaining the bending state of a conventional endoscope. Since the second bending portion 7b of the bending portion 7 contains a built-in object (for example, an inner guide sheath) that is not included in the first bending portion 7a, the second bending portion 7b is compared with the first bending portion 7a. It is hard to bend. Therefore, the curvature radius of the second bending portion 7b is larger than the curvature radius of the first bending portion 7a. In other words, the curvature of the first bending portion 7a is larger than the curvature of the second bending portion 7b.

例えば、図９のような湾曲部７の湾曲状態で、大腸検査のとき、挿入部を曲がりくねった大腸内で前進させようとしても、曲率の大きな第１湾曲部７ａが腸壁を強く押し付けてしまい、大腸が伸展して、挿入部２を大腸内で前進させることができない場合が生じ得る。 For example, in the case of a large intestine examination in the curved state of the curved portion 7 as shown in FIG. 9, the first curved portion 7a having a large curvature strongly presses the intestinal wall even when trying to advance the insertion portion in the large intestine. In some cases, the large intestine extends and the insertion portion 2 cannot be advanced in the large intestine.

また、図９に示すように、従来の内視鏡の場合、先端部６を反転視の状態にした場合、可撓管部８と先端部6間の距離Ｄ１は、図６に示す内視鏡１の先端部６を反転視の状態にした場合における可撓管部８と先端部6間の距離Ｄ２よりも短くなっている。そのため、長湾曲状態と短湾曲状態における視野範囲の差が大きくならない。 Further, as shown in FIG. 9, in the case of a conventional endoscope, when the distal end portion 6 is in a reverse viewing state, the distance D1 between the flexible tube portion 8 and the distal end portion 6 is the same as that shown in FIG. It is shorter than the distance D2 between the flexible tube portion 8 and the distal end portion 6 when the distal end portion 6 of the mirror 1 is in the reverse viewing state. Therefore, the difference in the visual field range between the long curved state and the short curved state does not increase.

これに対して、本実施の形態の内視鏡１では、被覆部材２１は、第１湾曲部分７ａを覆う第１の部分２１ａと、第２湾曲部分７ｂを覆う第２の部分２１ｂとを有し、長湾曲状態において第１湾曲部分７ａと第２湾曲部分７ｂの曲率半径が等しく若しくは略等しくなるように、第１の部分２１ａと第２の部分２１ｂは、円筒状の薄肉部の厚さが異なっている。
すなわち、本実施の形態の内視鏡１は、湾曲部７に図８に示すような被覆部材２１が設けられているため、長湾曲状態において、湾曲部７は、図６に示すように、湾曲する。よって、例えば、大腸検査のとき、挿入部を曲がりくねった大腸内で前進させたい場合、湾曲部７全体を湾曲させると、図６に示すように、湾曲部７は、湾曲部７全体が小さな曲率（すなわち大きな曲率半径）の状態にすることができる。その結果、挿入部２を大腸内に押し込むと、その曲がりくねった大腸が伸展することなく、挿入部２を、大腸内で前進させることができるので、挿入部２の挿入性はよい。 On the other hand, in the endoscope 1 of the present embodiment, the covering member 21 has a first portion 21a that covers the first curved portion 7a and a second portion 21b that covers the second curved portion 7b. The first portion 21a and the second portion 21b have the thickness of the cylindrical thin portion so that the curvature radii of the first curved portion 7a and the second curved portion 7b are equal or substantially equal in the long curved state. Is different.
That is, since the endoscope 1 of the present embodiment is provided with the covering member 21 as shown in FIG. 8 on the bending portion 7, in the long bending state, the bending portion 7 is as shown in FIG. Bend. Therefore, for example, in the case of a large intestine examination, when it is desired to advance the insertion portion in a tortuous colon, when the entire bending portion 7 is bent, the bending portion 7 has a small curvature as shown in FIG. (That is, a large radius of curvature). As a result, when the insertion portion 2 is pushed into the large intestine, the insertion portion 2 can be advanced in the large intestine without extending the tortuous large intestine, so that the insertion property of the insertion portion 2 is good.

以上のように、本実施の形態によれば、本発明は、１つの湾曲部において湾曲長を変更できる内視鏡において、各湾曲長における各部位の曲率あるいは曲率半径を等しく若しくは略等しくできる内視鏡を提供することができる。
（第２の実施の形態）
第１の実施の形態では、被覆部材は、先端側の第１の部分と基端側の第２の部分の薄肉部の厚さを変えることにより、湾曲部７の第１湾曲部７ａと第２湾曲部７ｂの両方が湾曲したときに、同じ若しくは略同じ曲率になるようにしているが、第２の実施の形態では、被覆部材の第１の部分と基端側の第２の部分の薄肉部の厚さは同じで、第１の部分と基端側の第２の部分のヤング率を変えることにより、湾曲部７の第１湾曲部７ａと第２湾曲部７ｂの両方が湾曲したときに、同じ若しくは略同じ曲率になるようにしている。 As described above, according to the present embodiment, the present invention is an endoscope in which the bending length can be changed in one bending portion, and the curvature or the radius of curvature of each part in each bending length can be made equal or substantially equal. An endoscope can be provided.
(Second Embodiment)
In the first embodiment, the covering member changes the thickness of the thin portion of the first portion on the distal end side and the second portion on the proximal end side, thereby changing the first bending portion 7a and the first bending portion 7 of the bending portion 7. When both of the two curved portions 7b are curved, the same or substantially the same curvature is obtained. However, in the second embodiment, the first portion of the covering member and the second portion on the proximal end side The thickness of the thin portion is the same, and both the first curved portion 7a and the second curved portion 7b of the curved portion 7 are bent by changing the Young's modulus of the first portion and the second portion on the proximal end side. Sometimes they have the same or nearly the same curvature.

本実施の形態の内視鏡の構成は、被覆部材の構成以外は、第１の実施の形態の内視鏡の構成と同じであるので、説明は省略し、被覆部材の構成についてのみ説明する。
図１０は、本実施の形態に係る被覆部材７１の構成を説明するための模式的な断面図である。被覆部材７１は、第１湾曲部７ａを覆う第１の部分７１ａと、第２湾曲部７ｂを覆う第２の部分７１ｂとを有する。被覆部材７１は、弾性を有する部材であり、例えば、フッ素ゴム、ウレタンゴム、ウレタン系エラストマー、等である。本実施の形態の筒状の被覆部材２１も、治具を用いて拡径された状態で、湾曲部７に装着され、湾曲部７に密着する。 Since the configuration of the endoscope according to the present embodiment is the same as the configuration of the endoscope according to the first embodiment except for the configuration of the covering member, description thereof will be omitted, and only the configuration of the covering member will be described. .
FIG. 10 is a schematic cross-sectional view for explaining the configuration of the covering member 71 according to the present embodiment. The covering member 71 includes a first portion 71a that covers the first curved portion 7a, and a second portion 71b that covers the second curved portion 7b. The covering member 71 is a member having elasticity, and is, for example, fluororubber, urethane rubber, urethane-based elastomer, or the like. The cylindrical covering member 21 of the present embodiment is also attached to the curved portion 7 and is in close contact with the curved portion 7 in a state where the diameter is expanded using a jig.

本実施の形態の被覆部材７１では、湾曲部７の第１湾曲部７ａと第２湾曲部７ｂの両方を湾曲させたときに、図６に示すように第１湾曲部７ａと第２湾曲部７ｂが同じ若しくは略同じ曲率半径で湾曲するように、第１湾曲部７ａを覆う第１の部分７１ａのヤング率Ｅ１は、第２湾曲部７ｂを覆う第２の部分７１ｂのヤング率Ｅ２よりも大きい。 In the covering member 71 of the present embodiment, when both the first bending portion 7a and the second bending portion 7b of the bending portion 7 are bent, the first bending portion 7a and the second bending portion are shown in FIG. The Young's modulus E1 of the first portion 71a covering the first curved portion 7a is larger than the Young's modulus E2 of the second portion 71b covering the second curved portion 7b so that 7b is curved with the same or substantially the same radius of curvature. large.

発明者の実験によれば、内視鏡の挿入部２の直径が、１２ｍｍで、内側ガイドシース４０の材質がステンレス（SUS）製で、太さ（直径）が１．３ｍｍのときに、第１の部分２１ａのヤング率Ｅ１と第２の部分２１ｂのヤング率Ｅ２の比率（Ｅ２／Ｅ１）は、０．６〜０．８が好ましい。特に、２つのヤング率の比率（Ｅ２／Ｅ１）は、０．６５〜０．７５が好ましい。 According to the inventor's experiment, when the diameter of the insertion portion 2 of the endoscope is 12 mm, the inner guide sheath 40 is made of stainless steel (SUS), and the thickness (diameter) is 1.3 mm, The ratio (E2 / E1) of the Young's modulus E1 of the first portion 21a and the Young's modulus E2 of the second portion 21b is preferably 0.6 to 0.8. In particular, the ratio of the two Young's moduli (E2 / E1) is preferably 0.65 to 0.75.

本実施の形態では、被覆部材７１は、第１湾曲部分７ａを覆う第１の部分７１ａと、第２湾曲部分７ｂを覆う第２の部分７１ｂとを有し、長湾曲状態において第１湾曲部分７ａと第２湾曲部分７ｂの曲率半径が等しく若しくは略等しくなるように、第１の部分７１ａと第２の部分７１ｂは、円筒状の薄肉部のヤング率が異なっている。そして、第２の部分７１ｂのヤング率は、第１の部分７１ａのヤング率よりも小さい。
被覆部材７１における第１の部分７１ａのヤング率Ｅ１と第２の部分７１ｂのヤング率Ｅ２とを異ならせる方法には、次の方法がある。
（第１の方法）
第１の方法は、被覆部材７１の外周面と内周面の少なくとも一方の第１の部分７１ａに対して、又は被覆部材７１の外周面と内周面の少なくとも一方の第１の部分７１ａと第２の部分７１ｂの両方に対して、表面コート処理を施すことにより、第１の部分７１ａのヤング率Ｅ１を、第２の部分７１ｂのヤング率Ｅ２よりも大きくする方法である。 In the present embodiment, the covering member 71 has a first portion 71a that covers the first curved portion 7a and a second portion 71b that covers the second curved portion 7b, and the first curved portion in the long-curved state. The first portion 71a and the second portion 71b have different Young's moduli of cylindrical thin portions so that the radii of curvature of 7a and the second curved portion 7b are equal or substantially equal. The Young's modulus of the second portion 71b is smaller than the Young's modulus of the first portion 71a.
There are the following methods for making the Young's modulus E1 of the first portion 71a and the Young's modulus E2 of the second portion 71b of the covering member 71 different.
(First method)
The first method is for at least one first portion 71a of the outer peripheral surface and inner peripheral surface of the covering member 71, or at least one first portion 71a of the outer peripheral surface and inner peripheral surface of the covering member 71; This is a method in which the Young's modulus E1 of the first portion 71a is made larger than the Young's modulus E2 of the second portion 71b by subjecting both of the second portions 71b to surface coating.

図１１は、被覆部材７１の外周面に施す表面コート処理を説明するための図である。図１１において実線で示すように、被覆部材７１の第１の部分７１ａの外周面７１ｓを、所定のコーティング材８１ａでコートし、被覆部材７１の第２の部分７１ｂの外周面７１ｓは、コーティング材８１ａでコートしない。 FIG. 11 is a diagram for explaining the surface coating process performed on the outer peripheral surface of the covering member 71. 11, the outer peripheral surface 71s of the first portion 71a of the covering member 71 is coated with a predetermined coating material 81a, and the outer peripheral surface 71s of the second portion 71b of the covering member 71 is coated with the coating material. Do not coat with 81a.

コーティング材８１ａは、例えば、フッ素である。コーティング材８１ａによりコートされた部分は、硬くなり、コーティング材８１ａによりコートされていない部分よりも、ヤング率は大きくなる。第１の部分７１ａにコートされるコーティング材８１ａの厚さは、湾曲部７の第１湾曲部７ａと第２湾曲部７ｂの両方を湾曲させたときに、図６に示すように第１湾曲部７ａと第２湾曲部７ｂが同じ若しくは略同じ曲率半径で湾曲するような厚さである。 The coating material 81a is, for example, fluorine. The portion coated with the coating material 81a becomes harder, and the Young's modulus becomes larger than the portion not coated with the coating material 81a. The thickness of the coating material 81a coated on the first portion 71a is such that when both the first bending portion 7a and the second bending portion 7b of the bending portion 7 are bent, as shown in FIG. The thickness is such that the portion 7a and the second curved portion 7b are curved with the same or substantially the same radius of curvature.

なお、コーティング材８１ａを、図１１において点線で示すように、第２の部分７１ｂの外周面７１ｓにもコートしてもよい。その場合、第２の部分７１ｂにコートされるコーティング材８１ａの厚さは、第１の部分７１ａにコートされるコーティング材８１ａの厚さよりも薄く、湾曲部７の第１湾曲部７ａと第２湾曲部７ｂの両方を湾曲させたときに、図６に示すように第１湾曲部７ａと第２湾曲部７ｂが同じ若しくは略同じ曲率半径で湾曲するような厚さの差がある。 Note that the coating material 81a may also be coated on the outer peripheral surface 71s of the second portion 71b as shown by a dotted line in FIG. In that case, the thickness of the coating material 81a coated on the second portion 71b is thinner than the thickness of the coating material 81a coated on the first portion 71a, and the first bending portion 7a and the second bending portion 7a of the bending portion 7 are the same. When both of the bending portions 7b are bent, there is a difference in thickness such that the first bending portion 7a and the second bending portion 7b are bent with the same or substantially the same radius of curvature as shown in FIG.

なお、その場合、第２の部分７１ｂにコートされるコーティング材の種類を、第１の部分７１ａにコートされるコーティング材８１ａと異なるようにしてもよい。ヤング率は、コートするコーティング材の種類とコートする厚さの少なくとも一方により変更することができる。 In this case, the type of coating material coated on the second portion 71b may be different from the coating material 81a coated on the first portion 71a. The Young's modulus can be changed by at least one of the type of coating material to be coated and the thickness to be coated.

さらになお、以上の例では、コーティング材８１ａは、被覆部材７１の外周面７１ｓにコートされるが、被覆部材７１の内周面７１ｔにコートするようにしてもよい。その場合も、コーティング材８１ａを、第１の部分７１ａの内周面７１ｔにのみコートしてもよいし、あるいは第１の部分７１ａと第２の部分７１ｂの両方の内周面７１ｔにコートするようにしてもよい。 Furthermore, in the above example, the coating material 81a is coated on the outer peripheral surface 71s of the covering member 71, but may be coated on the inner peripheral surface 71t of the covering member 71. Also in that case, the coating material 81a may be coated only on the inner peripheral surface 71t of the first portion 71a, or the inner peripheral surface 71t of both the first portion 71a and the second portion 71b. You may do it.

また、コーティング材８１ａを、外周面７１ｓと内周面７１ｔの両方をコートするようにしてもよい。なお、その場合も、第２の部分７１ｂの内周面７１ｔにコートされるコーティング材の種類を、第１の部分７１ａの内周面７１ｔにコートされるコーティング材８１ａと異なるようにしてもよい。 Further, the coating material 81a may be coated on both the outer peripheral surface 71s and the inner peripheral surface 71t. In this case as well, the type of coating material coated on the inner peripheral surface 71t of the second portion 71b may be different from the coating material 81a coated on the inner peripheral surface 71t of the first portion 71a. .

いずれの場合にしても、湾曲部７の第１湾曲部７ａと第２湾曲部７ｂの両方を湾曲させたときに、図６に示すように第１湾曲部７ａと第２湾曲部７ｂが同じ若しくは略同じ曲率半径で湾曲するように、コーティング材８１ａが、少なくとも第１の部分７１ａの外周面７１ｓ又は内周面７１ｔにコートされる。
（第２の方法）
第２の方法は、被覆部材７１の第１の部分７１ａに対して、又は第１の部分７１ａと第２の部分７１ｂの両方に対して、熱処理を施すことにより、第１の部分７１ａのヤング率Ｅ１を、第２の部分７１ｂのヤング率Ｅ２よりも大きくする方法である。 In any case, when both the first bending portion 7a and the second bending portion 7b of the bending portion 7 are bent, the first bending portion 7a and the second bending portion 7b are the same as shown in FIG. Alternatively, the coating material 81a is coated on at least the outer peripheral surface 71s or the inner peripheral surface 71t of the first portion 71a so as to be bent with substantially the same radius of curvature.
(Second method)
The second method is to apply a heat treatment to the first portion 71a of the covering member 71 or to both the first portion 71a and the second portion 71b. This is a method of making the rate E1 larger than the Young's modulus E2 of the second portion 71b.

ナイロン系のエラストマー等の材料は、熱処理により、硬くなるので、第１の部分７１ａに対して所定の温度で所定の時間だけ熱処理を施すと、第１の部分７１ａは、熱処理されない第２の部分７１ｂよりも、ヤング率は大きくなる。熱処理時の温度及び加熱する時間は、湾曲部７の第１湾曲部７ａと第２湾曲部７ｂの両方を湾曲させたときに、図６に示すように第１湾曲部７ａと第２湾曲部７ｂが同じ若しくは略同じ曲率半径で湾曲するような、温度及び時間である。 Since materials such as nylon-based elastomers become harder by heat treatment, when the first portion 71a is heat treated at a predetermined temperature for a predetermined time, the first portion 71a is not subjected to heat treatment. Young's modulus becomes larger than 71b. The temperature during the heat treatment and the heating time are such that when both the first bending portion 7a and the second bending portion 7b of the bending portion 7 are bent, the first bending portion 7a and the second bending portion as shown in FIG. Temperature and time such that 7b curves with the same or substantially the same radius of curvature.

なお、熱処理は、第２の部分７１ｂに対しても施してもよい。その場合、第２の部分７１ｂに対する熱処理における温度は、第１の部分７１ａに対する熱処理における温度よりも低くし、あるいは同じ温度であっても、第２の部分７１ｂを熱処理する時間は第１の部分７１ａを熱処理時間よりも短くして、湾曲部７の第１湾曲部７ａと第２湾曲部７ｂの両方を湾曲させたときに、図６に示すように第１湾曲部７ａと第２湾曲部７ｂが同じ若しくは略同じ曲率半径で湾曲するような、熱処理を、第１の部分７１ａと第２の部分７１ｂに施す。
（第３の方法）
第３の方法は、被覆部材７１の第１の部分７１ａと第２の部分７１ｂを互いに異なる材料にすることによって、第１の部分７１ａのヤング率Ｅ１を、第２の部分７１ｂのヤング率Ｅ２よりも大きくする方法である。 Note that the heat treatment may also be performed on the second portion 71b. In that case, the temperature in the heat treatment for the second portion 71b is lower than the temperature in the heat treatment for the first portion 71a, or the time for the heat treatment of the second portion 71b is the same as the first portion. When the first bending portion 7a and the second bending portion 7b of the bending portion 7 are both bent by making 71a shorter than the heat treatment time, the first bending portion 7a and the second bending portion as shown in FIG. Heat treatment is performed on the first portion 71a and the second portion 71b such that 7b is curved with the same or substantially the same radius of curvature.
(Third method)
In the third method, the first portion 71a and the second portion 71b of the covering member 71 are made of different materials, whereby the Young's modulus E1 of the first portion 71a is changed to the Young's modulus E2 of the second portion 71b. It is a way to make it bigger.

被覆部材７１の第１の部分７１ａと第２の部分７１ｂの材質が互いに異なり、第１の部分７１ａには、第２の部分７１ｂよりもヤング率が大きな材料を用いる。
被覆部材７１は、例えば、フッ素ゴム、ウレタンゴム、ウレタン系エラストマー等の材質からなる部材であり、例えば同じ材料であっても、製法あるいは成分により、ヤング率が異なる。そこで、第１の部分７１ａには、第２の部分７１ｂのヤング率よりも大きい材質のものを用いる。さらに、湾曲部７の第１湾曲部７ａと第２湾曲部７ｂの両方を湾曲させたときに、図６に示すように第１湾曲部７ａと第２湾曲部７ｂが同じ若しくは略同じ曲率半径で湾曲するようなヤング率をそれぞれ有する第１の部分７１ａと第２の部分７１ｂの材質が選択される。 The materials of the first portion 71a and the second portion 71b of the covering member 71 are different from each other, and a material having a Young's modulus greater than that of the second portion 71b is used for the first portion 71a.
The covering member 71 is, for example, a member made of a material such as fluoro rubber, urethane rubber, or urethane elastomer. For example, even if the same material is used, the Young's modulus varies depending on the manufacturing method or components. Therefore, a material having a material larger than the Young's modulus of the second portion 71b is used for the first portion 71a. Further, when both the first bending portion 7a and the second bending portion 7b of the bending portion 7 are bent, the first bending portion 7a and the second bending portion 7b have the same or substantially the same radius of curvature as shown in FIG. The material of the first portion 71a and the second portion 71b each having a Young's modulus so as to be curved is selected.

互いに異なるヤング率を有する第１の部分７１ａと第２の部分７１ｂは、端部が溶着又は接着されて、１つの被覆部材７１となる。
なお、被覆部材７１は、二色成形により、第１の部分７１ａと第２の部分７１ｂを形成するようにしてもよい。
さらになお、第１の部分７１ａと第２の部分７１ｂは、溶着等されずに、それぞれ別個に湾曲部７の第１湾曲部７ａと第２湾曲部７ｂに装着されてもよい。 End portions of the first portion 71 a and the second portion 71 b having different Young's modulus are welded or bonded to form one covering member 71.
In addition, you may make it the coating | coated member 71 form the 1st part 71a and the 2nd part 71b by two-color molding.
Furthermore, the first portion 71a and the second portion 71b may be separately attached to the first bending portion 7a and the second bending portion 7b of the bending portion 7 without being welded or the like.

以上のように、本実施の形態によれば、被覆部材の第１の部分と基端側の第２の部分のヤング率を変えることにより、湾曲部７の第１湾曲部７ａと第２湾曲部７ｂの両方が湾曲したときに、同じ若しくは略同じ曲率になるようにしている。 As described above, according to the present embodiment, the first bending portion 7a and the second bending portion of the bending portion 7 are changed by changing the Young's modulus of the first portion and the second portion on the proximal end side of the covering member. When both the parts 7b are curved, the same or substantially the same curvature is obtained.

よって、本実施の形態によれば、１つの湾曲部において湾曲長を変更できる内視鏡において、各湾曲長における各部位の曲率あるいは曲率半径を等しく若しくは略等しくできる内視鏡を実現することができる。 Therefore, according to the present embodiment, it is possible to realize an endoscope capable of making the curvature or the radius of curvature of each part in each bending length equal or substantially equal in an endoscope that can change the bending length in one bending portion. it can.

次に、上述した２つの実施の形態の変形例を説明する。
（変形例１）
第１の実施の形態では、被覆部材２１の先端側の第１の部分２１ａと基端側の第２の部分２１ｂの薄肉部の厚さを変え、第２の実施の形態では、被覆部材７１の第１の部分７１ａと基端側の第２の部分７１ｂのヤング率を変えることにより、湾曲部７の第１湾曲部７ａと第２湾曲部７ｂの両方が湾曲したときに、同じ若しくは略同じ曲率になるようにしている。 Next, modified examples of the above-described two embodiments will be described.
(Modification 1)
In the first embodiment, the thicknesses of the thin portions of the first portion 21a on the distal end side and the second portion 21b on the proximal end side of the covering member 21 are changed. In the second embodiment, the covering member 71 is changed. By changing the Young's modulus of the first portion 71a and the second portion 71b on the proximal end side, when both the first bending portion 7a and the second bending portion 7b of the bending portion 7 are bent, they are the same or substantially the same. The curvature is the same.

本変形例１では、第１の実施の形態と第２の実施の形態を組み合わせて、被覆部材２１の被覆部材２１の先端側の第１の部分２１ａと基端側の第２の部分２１ｂの薄肉部の厚さを変えると共に、被覆部材２１の第１の部分２１ａと基端側の第２の部分２１ｂのヤング率を変えることにより、湾曲部７の第１湾曲部７ａと第２湾曲部７ｂの両方が湾曲したときに、同じ若しくは略同じ曲率になるようにしている。 In the first modification, the first embodiment and the second embodiment are combined to form the first portion 21a on the distal end side of the covering member 21 and the second portion 21b on the proximal end side of the covering member 21. While changing the thickness of the thin portion and changing the Young's modulus of the first portion 21a and the second portion 21b of the base end side of the covering member 21, the first bending portion 7a and the second bending portion of the bending portion 7 are changed. When both 7b are curved, the same or substantially the same curvature is obtained.

このような構成によっても、第１及び第２の実施の形態と同様の効果を得ることができる。
（変形例２）
上述した２つの実施の形態及び変形例１では、湾曲部７の第１湾曲部７ａと第２湾曲部７ｂの外径が同じであるが、第１湾曲部７ａと第２湾曲部７ｂの外径が異なる場合がある。本変形例では、第１湾曲部７ａと第２湾曲部７ｂの外径が異なる場合は、第１湾曲部７ａの外径と第１の部分の内径との差と、第２湾曲部７ｂの外径と第２の部分の内径との差とが等しくなるように、被覆部材は形成される。 Even with such a configuration, the same effects as those of the first and second embodiments can be obtained.
(Modification 2)
In the two embodiments and the first modification described above, the outer diameters of the first bending portion 7a and the second bending portion 7b of the bending portion 7 are the same, but the outer sides of the first bending portion 7a and the second bending portion 7b are the same. The diameter may be different. In this modification, when the outer diameters of the first bending portion 7a and the second bending portion 7b are different, the difference between the outer diameter of the first bending portion 7a and the inner diameter of the first portion, and the second bending portion 7b The covering member is formed so that the difference between the outer diameter and the inner diameter of the second portion is equal.

図１２は、変形例２に係る、湾曲部７の第１湾曲部７ａと第２湾曲部７ｂの外径が異なる場合における被覆部材８１の構成を説明するための模式的な断面図である。被覆部材８１は、弾性を有する部材であり、第１の実施の形態の被覆部材２１と同じ、例えば、フッ素ゴム、ウレタンゴム、ウレタン系エラストマー、等の材質からなる。 FIG. 12 is a schematic cross-sectional view for explaining the configuration of the covering member 81 when the outer diameters of the first bending portion 7a and the second bending portion 7b of the bending portion 7 are different according to the second modification. The covering member 81 is a member having elasticity, and is made of the same material as the covering member 21 of the first embodiment, for example, fluorine rubber, urethane rubber, urethane elastomer, and the like.

図１２に示すように、被覆部材８１は、湾曲部７全体を被覆するような長さを有する筒状部材である。被覆部材８１は、第１湾曲部７ａを覆う第１の部分８１ａと、第２湾曲部７ｂを覆う第２の部分８１ｂとを有する。図１２に示すように、第１の部分８１ａの薄肉部の厚さは、第２の部分８１ｂの薄肉部の厚さよりも厚い。 As shown in FIG. 12, the covering member 81 is a cylindrical member having a length that covers the entire bending portion 7. The covering member 81 includes a first portion 81a that covers the first curved portion 7a, and a second portion 81b that covers the second curved portion 7b. As shown in FIG. 12, the thickness of the thin portion of the first portion 81a is thicker than the thickness of the thin portion of the second portion 81b.

なお、第２の実施の形態で説明したように、第１の部分８１ａと第２の部分８１ｂのヤング率が異なる場合は、第１の部分８１ａの薄肉部の厚さと、第２の部分８１ｂの薄肉部の厚さは同じであってもよい。 As described in the second embodiment, when the Young's modulus of the first portion 81a and the second portion 81b is different, the thickness of the thin portion of the first portion 81a and the second portion 81b The thickness of the thin wall portion may be the same.

被覆部材８１は、外径Ｒ１の第１湾曲部７ａと、外径Ｒ１よりも大きな外径Ｒ２を有する第２湾曲部７ｂからなる湾曲部７に装着される。なお、湾曲部７に装着する前の状態における被覆部材８１の内径ｒ１とｒ２は、それぞれ湾曲部７の第１湾曲部７ａの外径Ｒ１と第２湾曲部７ａのＲ２よりも小さい。ここでは、第１湾曲部７ａの外径Ｒ１と第２湾曲部７ａの外径Ｒ２は、ブレード７ｄを含む外径である。
そして、湾曲部７に装着する前における被覆部材８１の第１の部分８１ａの内径ｒ１は、第２の部分８１ｂの内径ｒ２よりも小さく、かつ、第１の部分８１ａの内径ｒ１と第１湾曲部７ａの外径Ｒ１との差ｄｄ１と、第２の部分８１ｂの内径ｒ２と第２湾曲部７ｂの外径Ｒ２との差ｄｄ２が等しく若しくは略等しくなるように、被覆部材８１は形成されている。
すなわち、第２湾曲部７ｂを被覆する、湾曲部７に装着する前における第２の部分８１ｂの円筒状の内径と、第２湾曲部７ｂの外径との第１の差は、第１湾曲部７ａを被覆する、湾曲部７に装着する前における第１の部分８１ａの円筒状の内径と、第１湾曲部７ａの外径との第２の差と、等しい若しくは略等しい。 The covering member 81 is attached to the bending portion 7 including the first bending portion 7a having the outer diameter R1 and the second bending portion 7b having the outer diameter R2 larger than the outer diameter R1. Note that the inner diameters r1 and r2 of the covering member 81 in a state before being attached to the bending portion 7 are smaller than the outer diameter R1 of the first bending portion 7a of the bending portion 7 and R2 of the second bending portion 7a, respectively. Here, the outer diameter R1 of the first bending portion 7a and the outer diameter R2 of the second bending portion 7a are outer diameters including the blade 7d.
The inner diameter r1 of the first portion 81a of the covering member 81 before being attached to the bending portion 7 is smaller than the inner diameter r2 of the second portion 81b, and the inner diameter r1 of the first portion 81a and the first curve. The covering member 81 is formed so that the difference dd1 between the outer diameter R1 of the portion 7a and the difference dd2 between the inner diameter r2 of the second portion 81b and the outer diameter R2 of the second curved portion 7b are equal or substantially equal. Yes.
That is, the first difference between the cylindrical inner diameter of the second portion 81b that covers the second bending portion 7b and is attached to the bending portion 7 and the outer diameter of the second bending portion 7b is the first bending The second difference between the cylindrical inner diameter of the first portion 81a that covers the portion 7a and is attached to the bending portion 7 is equal to or substantially equal to the outer diameter of the first bending portion 7a.

差ｄｄ１と差ｄｄ２が等しいので、被覆部材８１による湾曲部７の第１の部分８１ａと第２の部分８１ｂへの締め付け力の差による曲がり難さの差が生じない。
よって、このような構成によっても、第１及び第２の実施の形態と同様の効果を得ることができる。 Since the difference dd1 and the difference dd2 are equal, there is no difference in bending difficulty due to the difference in tightening force between the first portion 81a and the second portion 81b of the bending portion 7 by the covering member 81.
Therefore, even with such a configuration, it is possible to obtain the same effects as those of the first and second embodiments.

以上のように、上述した各実施の形態及び各変形例によれば、１つの湾曲部において湾曲長を変更できる内視鏡において、各湾曲長における各部位の曲率あるいは曲率半径を等しく若しくは略等しくできる内視鏡を実現することができる。 As described above, according to each embodiment and each modification described above, in an endoscope in which the bending length can be changed in one bending portion, the curvature or the radius of curvature of each part in each bending length is equal or substantially equal. Endoscope that can be realized.

本発明は、上述した実施の形態に限定されるものではなく、本発明の要旨を変えない範囲において、種々の変更、改変等が可能である。 The present invention is not limited to the above-described embodiments, and various changes and modifications can be made without departing from the scope of the present invention.

１内視鏡、２挿入部、３操作部、３ａ移動部材固定機構、３ｂパイプ止め部材、４ユニバーサルコード、５コネクタ、６先端部、６ａ先端硬質部材、６ｂ先端キャップ、７湾曲部、７ａ第１湾曲部、７ｂ第２湾曲部、７ｃ湾曲駒、７ｄブレード、８可撓管部、９グリップ部、１０ａ、１０ｂ湾曲操作ノブ、１１湾曲範囲切り換えレバー、２１被覆部材、２１ａ第１の部分、２１ｂ第２の部分、３０ワイヤ、４０内側ガイドシース、５０外側ガイドシース、６０固定部。 DESCRIPTION OF SYMBOLS 1 Endoscope, 2 insertion part, 3 operation part, 3a moving member fixing mechanism, 3b pipe fixing member, 4 universal cord, 5 connector, 6 tip part, 6a tip hard member, 6b tip cap, 7 bending part, 7a 1st 1 bending portion, 7b second bending portion, 7c bending piece, 7d blade, 8 flexible tube portion, 9 grip portion, 10a, 10b bending operation knob, 11 bending range switching lever, 21 covering member, 21a first portion, 21b 2nd part, 30 wires, 40 inner guide sheath, 50 outer guide sheath, 60 fixing | fixed part.

Claims

An insertion section that can be inserted into the lumen;
An operation portion provided on a proximal end side of the insertion portion and having a bending operation member;
A bending portion that is provided on a distal end side of the insertion portion and is bent by operating the bending operation member,
Switching between a first state in which only the first curved portion on the distal end side of the curved portion is curved and a second state in which the first curved portion and the second curved portion on the proximal end side of the curved portion are curved. A possible endoscope,
A cylindrical covering member provided to cover the curved portion and having elasticity;
The covering member includes a first part that covers the first curved part and a second part that covers the second curved part, and the first curved part and the second curved part in the second state. The first portion and the second portion are different in the thickness of the cylindrical thin portion so that the radii of curvature of the portions are equal or substantially equal,
Before Symbol thickness of the thin portion of the second portion, the inner you, characterized in that characterized in that less than the thickness of the thin portion of the first portion endoscope.

Claims the thickness of the thin portion of the front Stories second portion, characterized in that characterized in that 0.6 to 0.8 times the thickness of the thin portion of the first portion 1. The endoscope according to 1 .

An insertion section that can be inserted into the lumen;
An operation portion provided on a proximal end side of the insertion portion and having a bending operation member;
A bending portion that is provided on a distal end side of the insertion portion and is bent by operating the bending operation member,
Switching between a first state in which only the first curved portion on the distal end side of the curved portion is curved and a second state in which the first curved portion and the second curved portion on the proximal end side of the curved portion are curved. A possible endoscope,
A cylindrical covering member provided to cover the curved portion and having elasticity;
The covering member includes a first part that covers the first curved part and a second part that covers the second curved part, and the first curved part and the second curved part in the second state. The first part and the second part are different in Young's modulus so that the radii of curvature of the parts are equal or substantially equal;
Before SL Young's modulus of the second portion, the inner it is smaller than the Young's modulus of the first portion endoscope.

The first difference between the cylindrical inner diameter of the second portion and the outer diameter of the second curved portion before covering the second curved portion and being attached to the curved portion is the first curved portion. The second difference between the cylindrical inner diameter of the first portion and the outer diameter of the first curved portion before being attached to the curved portion is equal or substantially equal. Item 4. The endoscope according to any one of Items 1 to 3 .