Patent Publication Number: US-11653817-B2

Title: Endoscope

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     The present application is a Continuation of PCT International Application No. PCT/JP2018/022360 filed on Jun. 12, 2018 claiming priority under 35 U.S.C. § 119(a) to Japanese Patent Application No. 2017-139138 filed on Jul. 18, 2017. Each of the above applications is hereby expressly incorporated by reference, in its entirety, into the present application. 
    
    
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to endoscopes, and more particularly relates to an endoscope including a treatment tool erecting base that changes a lead-out direction of a treatment tool, at a distal end part of an insertion section. 
     2. Description of the Related Art 
     In an endoscope, one of various treatment tools is led in from a treatment tool lead-in port provided in a hand operation section (hereinafter, referred to as “operation section”), and the treatment tool is led out from a treatment tool lead-out port opening in a distal end member of an insertion section to the outside to be used for a treatment. For example, a treatment tool, such as forceps or a contrast agent tube, is used for a duodenum endoscope, and a treatment tool, such as a puncture needle, is used for an ultrasonic endoscope. With such a treatment tool, to provide a treatment at a desirable position in a subject, a lead-out direction of the treatment tool that is led out from the treatment tool lead-out port needs to be changed. Hence, the distal end member is provided with a treatment tool erecting base (hereinafter, referred to as “erecting base”), and the endoscope is provided with a treatment tool erecting mechanism that changes the posture of the erecting base between an erecting position and a lying position. 
     For the treatment tool erecting mechanism, a wire pulling mechanism is known (see JP1994-315458A (JP-H6-315458A)), in which a distal end portion of a wire (also referred to as forceps erecting wire) is directly attached to an erecting base. The mechanism couples the proximal end side of the wire to an erecting operation lever (also referred to as forceps erecting lever) included in an operation section, operates the wire to be pushed/pulled by using the erecting operation lever to rotate the erecting base around a rotation shaft, and hence changes the posture of the erecting base between an erecting position and a lying position. 
     More specifically, the operation section of JP1994-315458A (JP-H6-315458A) is provided with a grip part for holding the operation section with a hand, and an angle knob. The operation section has a wire opening portion below the grip part, and a drive shaft opening portion in the grip part. The proximal end of the wire is led out from the wire opening portion. The distal end of the drive shaft that is moved by the forceps erecting lever is led out from the drive shaft opening portion. The distal end of the drive shaft and the proximal end of the wire are removably coupled to a connecting tool. A protection cover that covers the connecting tool is provided on the operation section in an attachable/detachable manner. 
     When an endoscope is used for one of various inspections or one of various treatments, liquid in a body cavity adheres to the distal end member of the insertion section including the erecting base and to a guide pipe through which the wire is inserted. The endoscope after use is subjected to washing and disinfection processing using a washing solution and a disinfectant. At this time, since the guide pipe has a small diameter and the wire is inserted through the inside of the guide pipe, washing is troublesome. 
     Owing to this, in the endoscope of JP1994-315458A (JP-H6-315458A)), the cover covering the distal end member of the insertion section, the erecting base, and the wire are provided in an attachable/detachable manner; the cover, the erecting base, and the wire are removed; and the distal end member of the insertion section and the guide pipe of the wire are washed. 
     Moreover, EP1759626B discloses an endoscope in which the proximal end of a cable cord is led out from the proximal end of a control handle, and a collet is connected to the proximal end of the cable cord. The collet is fastened to a nut and moves in the front-rear direction by an operation lever. 
     SUMMARY OF THE INVENTION 
     However, since the endoscope of JP1994-315458A (JP-H6-315458A) is configured such that the connecting tool serving as the erecting operation mechanism is housed in the narrow area in the operation section, the attachment/detachment operation of the proximal end of the wire to/from the erecting operation mechanism is troublesome. 
     In addition, with the endoscope of JP1994-315458A (JP-H6-315458A), the operation section increases in size by the amount that the connecting tool of the erecting operation mechanism is housed in the operation section. 
     With the endoscope of EP1759626B, the cable cord is led out to the outside of the control handle, and the distal end of the cable cord is mounted at the collet and the nut in an attachable/detachable manner. However, the attachment/detachment operation is troublesome. 
     Regarding a duodenum endoscope, a treatment tool led out from the distal end of an insertion section with the direction thereof changed at an erecting base is inserted from the Vater papilla of the duodenum into the bile duct or the pancreatic duct, and a treatment is performed. A treatment tool, such as forceps or a contrast agent tube, is used. When the treatment tool is replaced, a guide wire is used and a treatment tool is inserted along the guide wire. Thus, the treatment tool can be inserted to a treatment position, and a burden on an operator during a replacement work can be reduced. 
     To prevent a phenomenon in which the guide wire moves during the replacement of the treatment tool and the guide wire comes out from the Vater papilla from occurring, a guide wire locking device that fixes the guide wire may be used. The guide wire locking device is used by winding a band of the guide wire locking device around an operation section of an endoscope and fixing the guide wire with a main body portion. However, when the guide wire locking device is wound around the operation section, the guide wire locking device may limit the operation of the endoscope. 
     The present invention is made in light of the situations, and it is an object of the invention to provide an endoscope in which, even when a guide wire locking device is mounted, an operation of a treatment tool erecting base is not limited and the treatment tool erecting base can be reliably moved. 
     To attain the object of the present invention, an endoscope according to the present invention includes an operation section provided with an operating member; an insertion section that is provided on a distal end side of the operation section and that is inserted into a subject; a treatment tool erecting base provided at a distal end part of the insertion section; a movable member that is arranged to be exposed to outside of the operation section and that moves in association with an operation of the operating member; an erecting operation wire that is coupled to the treatment tool erecting base at a distal end side thereof, that is coupled to the movable member at a proximal end side thereof, and that is pushed/pulled in accordance with a movement of the movable member to move the treatment tool erecting base; an attachment member that is provided at a proximal end of the erecting operation wire and that is engaged with the movable member in an attachable/detachable manner; and an interference prevention section that is provided at a position of the operation section on a proximal end side with respect to the movable member and that prevents an interference with the movable member. 
     According to an aspect of the present invention, preferably, the interference prevention section is configured of an interference prevention wall vertically extending from an outer wall surface of the operation section. 
     According to an aspect of the present invention, preferably, the interference prevention wall is configured of an interference prevention plate formed in a ring shape around the outer wall surface of the operation section. 
     According to an aspect of the present invention, preferably, the interference prevention wall is configured of a plurality of interference prevention bodies that are arranged around the outer wall surface of the operation section and that are spaced apart from one another. 
     According to an aspect of the present invention, preferably, the operation section has an operation section main body provided with the operating member, a holding part connected to the operation section main body, and an extension part extending from the holding part toward a distal end side; the extension part is provided with the movable member; and the interference prevention section is provided at a connection portion between the extension part and the holding part. 
     According to an aspect of the present invention, preferably, an engagement hole is provided in one of the movable member and the attachment member, and an engagement portion that is engaged with the engagement hole in an attachable/detachable manner is provided at the other one. 
     According to an aspect of the present invention, preferably, the engagement portion is provided with an elastic deformation portion that is elastically deformed and engaged with the engagement hole. 
     According to an aspect of the present invention, preferably, a pair of claw portions are formed at the elastic deformation portion, the pair of claw portions being elastically deformable and configured to be latched to an edge portion of the engagement hole, the pair of claw portions being displaced in directions to move toward each other by elastic deformation when the engagement portion is engaged with or disengaged from the engagement hole. 
     According to an aspect of the present invention, preferably, the engagement hole has a small width portion having a first width, and a large width portion having a second width that is larger than the first width; and the engagement portion has a shaft portion having an outside diameter that is equal to or smaller than the first width, and a large diameter portion provided at a distal end of the shaft portion and having an outside diameter that is larger than the first width and smaller than the second width. 
     According to an aspect of the present invention, preferably, one of the movable member and the attachment member is provided with a cylindrical body extending in a direction perpendicular to an axial direction of the erecting operation wire, and the other one is provided with a ring-shaped body that is rotatably engaged with an outer periphery of the cylindrical body; and the endoscope includes a rotation restriction stopper that restricts relative rotations of the cylindrical body and the ring-shaped body. 
     According to an aspect of the present invention, preferably, the endoscope includes an engagement member provided at a distal end of the erecting operation wire; and a housing groove that is provided in the treatment tool erecting base and that is engaged with the engagement member in an engageable/disengageable manner. 
     According to an aspect of the present invention, preferably, the endoscope includes a proximal end opening provided in the operation section; a distal end opening provided in the distal end part; and an erecting operation wire channel that is provided in the insertion section and that causes the proximal end opening to communicate with the distal end opening. The erecting operation wire is inserted through the erecting operation wire channel, has the distal end side that is arranged outside the distal end opening and that is coupled to the treatment tool erecting base, and has the proximal end side that is arranged outside the proximal end opening and that is coupled to the movable member. 
     According to an aspect of the present invention, preferably, the movable member is rotatably provided while a direction perpendicular to an axial direction of the erecting operation wire serves as a rotation axis. 
     According to an aspect of the present invention, preferably, the operating member is an operating member rotatably supported by the operation section; and the endoscope includes a first conversion mechanism that converts a rotational motion of the operating member into a linear motion, a drive member that is linearly driven by the first conversion mechanism, and a second conversion mechanism that converts a linear motion of the drive member into a rotational motion to rotate the movable member. 
     According to an aspect of the present invention, preferably, the second conversion mechanism includes a speed reduction mechanism. 
     With the present invention, since the operation section is provided with the interference prevention section, the endoscope in which an interference with the movable member that moves the treatment tool erecting base can be prevented and the treatment tool erecting base can be reliably moved can be provided. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG.  1    is a configuration diagram of an endoscope system including an endoscope according to an embodiment; 
         FIG.  2    is a perspective view of a distal end member when an erecting base is located at a lying position; 
         FIG.  3    is a perspective view of the distal end member when the erecting base is located at an erecting position; 
         FIG.  4    is an enlarged perspective view of the erecting base; 
         FIG.  5    is a main-part sectional view illustrating an attachment structure of the erecting base to the distal end member; 
         FIG.  6    is a perspective view illustrating the other side surface opposite to one side surface of an operation section illustrated in  FIG.  1   ; 
         FIG.  7    is an enlarged perspective view when an engagement portion is housed in a housing portion via an engagement guide portion; 
         FIG.  8    is a movement explanatory diagram when the engagement portion is guided by the engagement guide portion and housed in the housing portion; 
         FIG.  9    is a configuration diagram illustrating the entire configuration of an erecting operation mechanism; 
         FIG.  10    is a side view of the erecting operation mechanism in  FIG.  9   ; 
         FIG.  11    is a perspective view of a coupling structure according to a first embodiment; 
         FIG.  12    is a perspective view when the coupling structure illustrated in  FIG.  11    is viewed from the left; 
         FIG.  13    is a perspective view of a wire assembly; 
         FIG.  14    is a front view of an attachment member; 
         FIG.  15    is a perspective view of an extension part illustrating a lead-in port and a movable member; 
         FIG.  16    is an explanatory diagram when a wire is inserted from the lead-in port while an engagement member is at the head; 
         FIG.  17    is an explanatory diagram of the attachment member in a state in which the distal end of the wire is coupled to the erecting base; 
         FIG.  18    is an explanatory diagram when the attachment member is coupled to the movable member; 
         FIG.  19    is an explanatory diagram illustrating a modification of the coupling structure according to the first embodiment; 
         FIG.  20    is a main-part sectional view of the coupling structure illustrated in  FIG.  19   ; 
         FIG.  21    is a sectional view illustrating a state in which a valve body is mounted at the lead-in port; 
         FIG.  22    is an overall view of a guide wire locking device; 
         FIG.  23    is a perspective view when the guide wire locking device is mounted; 
         FIG.  24    is an enlarged perspective view when the guide wire locking device is mounted; 
         FIG.  25    is a perspective view illustrating a modification of an interference prevention wall; 
         FIG.  26    is a perspective view illustrating another modification of an interference prevention wall; 
         FIG.  27    is a perspective view illustrating still another modification of an interference prevention wall; 
         FIG.  28    is a perspective view illustrating yet another modification of an interference prevention wall; 
         FIG.  29    is a perspective view illustrating a further modification of an interference prevention wall; 
         FIG.  30    is a configuration diagram of an endoscope system including an endoscope having an interference prevention section according to another embodiment; 
         FIG.  31    is a perspective view of an interference prevention section according to the other embodiment; 
         FIG.  32    is a perspective view of a coupling structure according to a second embodiment; 
         FIG.  33    is an assembly perspective view of the coupling structure illustrated in  FIG.  32   ; 
         FIG.  34    is a main-part sectional view of the coupling structure illustrated in  FIG.  32   ; 
         FIG.  35    is a plan view illustrating the size of an engagement portion with respect to an engagement hole; 
         FIG.  36    is an assembly perspective view of a coupling structure according to a third embodiment; 
         FIG.  37    is a plan view of an engagement hole illustrating the size of an engagement portion with respect to the engagement hole; 
         FIG.  38    is a perspective view of a coupling structure according to a fourth embodiment; 
         FIG.  39    is an assembly perspective view of the coupling structure illustrated in  FIG.  38   ; 
         FIG.  40    illustrates a main-part structure in which a first slider and a lever are coupled to each other by using a link sheet metal serving as a link mechanism; and 
         FIG.  41    is a movement explanatory diagram of the link mechanism in  FIG.  40   . 
     
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Endoscopes according to preferred embodiments of the present invention are described in detail below with reference to the accompanying drawings. 
       FIG.  1    is a configuration diagram of an endoscope system  12  including an endoscope  10  according to an embodiment of the present invention. The endoscope system  12  includes an endoscope  10 , a processor device  14 , a light source device  16 , and a display  18 .  FIG.  1    also illustrates a treatment tool  56  that is used in the endoscope system  12 . 
     The endoscope  10  includes an operation section  22  including an erecting operation lever  20  that serves as an operating member, and an insertion section  24  provided on the distal end side of the operation section  22 . 
     Referring to perspective views in  FIGS.  2  and  3    illustrating the configuration of a distal end part  26  of the insertion section  24 , a distal end member  28  is provided at the distal end part  26  of the insertion section  24 , and an erecting base  30  (described later) is attached to the distal end member  28 .  FIG.  2    is a perspective view of the distal end member  28  when the erecting base  30  is located at a lying position.  FIG.  3    is a perspective view of the distal end member  28  when the erecting base  30  is located at an erecting position. 
     In the following description, an upward direction indicates a Z(+) direction in  FIGS.  1  and  2   , and a downward direction indicates a Z(−) direction in  FIGS.  1  and  2   . Moreover, a rightward direction indicates an X(+) direction in  FIG.  2   , and a leftward direction indicates an X(−) direction in  FIG.  2   . Furthermore, a Y(+) direction in  FIGS.  1  and  2    indicates a distal end side direction of the distal end member  28 , and a Y(−) direction in  FIGS.  1  and  2    indicates a proximal end side direction of the distal end member  28 . 
     Referring back to  FIG.  1   , the operation section  22  has an operation section main body  32  provided with the erecting operation lever  20 , a holding part  34  connected to the operation section main body  32 , and an extension part  36  extending from the holding part  34  toward the distal end side. A proximal end portion of the insertion section  24  is provided on the distal end side of the extension part  36  via a break prevention pipe  38 . 
     The extension part  36  is included in the operation section  22  to provide a movable member  96  (described later, see  FIG.  6   ), and is a part in a non-holding region that is extended from a distal end portion of the holding part  34  that is held by an operator toward the distal end side. Regarding the extension part  36 , a region A extending from a circular-ring-shaped interference prevention wall  40  that is provided at the holding part  34  and that configures an interference prevention section  300  to a proximal end portion  38 A of the break prevention pipe  38  is defined as the extension part  36 . 
     The operation section main body  32  of the operation section  22  includes a universal cord  46 . A light source connector  50  is provided on the distal end side of the universal cord  46 . An electric connector  48  branches out from the light source connector  50 . The electric connector  48  is connected to the processor device  14 , and the light source connector  50  is connected to the light source device  16 . 
     The insertion section  24  includes the distal end part  26 , a bending part  52 , and a soft part  54  that are coupled from the distal end side toward the proximal end side. 
     The insertion section  24  incorporates the following contents. In particular, the contents include, for example, a treatment tool channel  58  that guides a distal end portion  56 A of the treatment tool  56  in  FIG.  1    to the distal end member  28  in  FIG.  2   ; an erecting operation wire  60  (hereinafter, referred to as wire  60 ) for performing an operation of changing a lead-out direction of the distal end portion  56 A of the treatment tool  56  led out from the distal end member  28 ; an erecting operation wire channel  62  (hereinafter, referred to as wire channel  62 ) that guides a distal end portion of the wire  60  to the distal end member  28 ; a light guide (not illustrated) that guides illumination light supplied from the light source device  16  in  FIG.  1    to the distal end member  28  in  FIG.  2   ; an air/water supply tube (not illustrated); an angle wire (not illustrated); and a signal cable (not illustrated). 
     Referring back to  FIG.  1   , the operation section  22  is formed in a substantially cylindrical shape as a whole and has a cylinder axis B along the Y(+)-Y(−) direction. A pair of angle knobs  64  that perform an operation of bending the bending part  52  are arranged at a side surface  22 A on one side with respect to a section extending in the up-down direction and including the cylinder axis B of the operation section  22 . The pair of angle knobs  64  are coaxially rotatably provided. 
     The bending part  52  has a structure in which a plurality of angle rings (not illustrated) are mutually rotatably coupled. The bending part  52  is configured such that the outer periphery of the structure is covered with a tubular mesh body braided using metal wires, and the outer peripheral surface of the mesh body is covered with a tubular outer sheath made of rubber. For example, four angle wires (not illustrated) are disposed to extend from the thus configured bending part  52  to the angle knobs  64 . An operation of pushing/pulling the angle wires is performed by an operation of rotating the angle knobs  64  to bend the bending part  52  upward, downward, leftward, and rightward. 
     Moreover, on the operation section main body  32  of the operation section  22 , an air/water supply button  66  and a suction button  68  are arranged side by side. By operating the air/water supply button  66 , the air and water can be ejected from an air/water supply nozzle  70  provided in the distal end member  28  in  FIG.  2   . By operating the suction button  68  in  FIG.  1   , body fluids such as blood can be sucked from a suction port that also serves as a treatment tool lead-out port  72  provided in the distal end member  28  in  FIG.  2   . 
     Furthermore, a treatment tool lead-in port  42  is provided in the holding part  34  of the operation section  22  in  FIG.  1   . The treatment tool  56  is led in to the treatment tool lead-in port  42 . The treatment tool  56  led in from the treatment tool lead-in port  42  while the distal end portion  56 A is at the head is inserted through the treatment tool channel  58  in  FIG.  2    inserted through the insertion section  24 , and is led out to the outside from the treatment tool lead-out port  72  provided in the distal end member  28 . 
     The erecting operation lever  20  is rotatably provided at the one side surface  22 A of the operation section  22  in  FIG.  1    in a manner coaxial with the angle knobs  64 . The erecting operation lever  20  is rotationally operated by a hand of the operator who holds the holding part  34 . When the erecting operation lever  20  is rotationally operated, the wire  60  in  FIG.  2    is pushed/pulled by an erecting operation mechanism  120  (see  FIGS.  9  and  10   ) that moves in association with the rotational operation of the erecting operation lever  20 , and the posture of the erecting base  30  coupled to the distal end side of the wire  60  is changed between an erecting position in  FIG.  3    and a lying position in  FIG.  2   . The above-described erecting operation mechanism  120  will be described later. 
     The soft part  54  illustrated in  FIG.  1    has a helical pipe (not illustrated) formed by winding a thin elastic strip-shaped plate made of metal in a helical form. The outside of the helical pipe of the soft part  54  is covered with a tubular mesh body braided using metal wires. The outer peripheral surface of the mesh body is covered with a tubular outer sheath made of resin. 
     The endoscope  10  according to the thus configured embodiment is a side-view endoscope used as a duodenum endoscope. The insertion section  24  is inserted into a subject via the oral cavity. The insertion section  24  is inserted from the esophagus via the stomach to the duodenum, and, for example, a treatment, such as a predetermined inspection or a predetermined medical care, is performed. 
     In the embodiment, biopsy forceps serve as an example of the treatment tool  56 , the biopsy forceps having a cup capable of collecting a living tissue at the distal end portion  56 A. However, it is not limited thereto. For example, a treatment tool, such as a contrast agent tube or an endoscopic sphincterotomy (EST) knife, is used as another treatment tool. 
     Next, the distal end part  26  of the insertion section  24  is described. 
     Referring to  FIG.  2   , the distal end part  26  of the insertion section  24  is configured of the distal end member  28 , and a cap  76  that is mounted on the distal end member  28  in an attachable/detachable manner. The cap  76  has a substantially tubular shape whose distal end side is sealed. A substantially rectangular opening window  76 A is formed in part of the outer peripheral surface of the cap  76 . When the cap  76  is mounted on the distal end member  28 , the opening window  76 A of the cap  76  communicates with the treatment tool lead-out port  72  of the distal end member  28 . Thus, the distal end portion  56 A of the treatment tool  56  led out from the treatment tool lead-out port  72  is led out to the outside from the opening window  76 A. 
     The cap  76  is made of an elastic material, for example, a rubber material, such as fluorocarbon rubber or silicon rubber; or a resin material such as polysulfone. An engagement portion (not illustrated) is provided on the proximal end side of the cap  76 . The engagement portion is engaged with a groove (not illustrated) formed in the distal end member  28 . By engaging the engagement portion with the groove of the distal end member  28 , the cap  76  is mounted on the distal end member  28 . When the treatment with the endoscope  10  is ended, the cap  76  is removed from the distal end member  28 , and washed and disinfected, or discarded as a disposable. 
     The distal end member  28  is made of a corrosion-resistant metal material. Moreover, in the distal end member  28 , a partition wall  78  protruding toward the distal end side and a partition wall  80  opposite to the partition wall  78  are integrally provided. An erecting base housing chamber  82  that houses the erecting base  30  is formed between the partition wall  78  and the partition wall  80 . The treatment tool lead-out port  72  that leads out the treatment tool  56  to the outside is formed on the proximal end side of the erecting base housing chamber  82 . A distal end portion of the treatment tool channel  58  is connected to the treatment tool lead-out port  72 . 
     The treatment tool channel  58  is inserted through the inside of the insertion section  24  in  FIG.  1   . A proximal end portion of the treatment tool channel  58  is connected to a distal end pipe  202  of a branch pipe  200  (see  FIG.  10   ) provided in the operation section  22 . 
     The branch pipe  200  has a known structure. A proximal end portion of the branch pipe  200  is branched into two pipe lines  204  and  206 . The treatment tool lead-in port  42  is formed at the proximal end of the one pipe line  204 . The distal end portion  56 A of the treatment tool  56  led in from the treatment tool lead-in port  42  to the treatment tool channel  58  via the pipe line  204  is inserted through the treatment tool channel  58 , and is led out from the treatment tool lead-out port  72  in  FIG.  2    to the erecting base housing chamber  82 . The lead-out direction of the distal end portion  56 A of the treatment tool  56  led out to the erecting base housing chamber  82  is changed in accordance with the posture between the erecting position and the lying position of the erecting base  30  arranged in the erecting base housing chamber  82 . Moreover, the distal end of a suction pipe  208  for sucking body fluids such as blood is connected to the proximal end of the other pipe line  206  of the branch pipe  200  illustrated in  FIG.  10   . 
       FIG.  4    is an enlarged perspective view of the erecting base  30 . Referring to  FIG.  4   , a guide surface  30 A is included in an upper surface of the erecting base  30 . Along the guide surface  30 A, the distal end portion  56 A of the treatment tool  56  in  FIG.  1    is led out to the outside from the opening window  76 A of the cap  76  in  FIG.  2   . 
     Referring to  FIG.  4   , the erecting base  30  includes rotation shafts  84  and  86  on both side surfaces of a base portion  30 B of the erecting base  30 . The axial direction of the rotation shafts  84  and  86  is set in the X(+)-X(−) direction in  FIG.  2    when the erecting base  30  is attached to the distal end member  28 . 
       FIG.  5    is a main-part sectional view illustrating an attachment structure of the erecting base  30  to the distal end member  28 . Referring to  FIG.  5   , the axes of the rotation shafts  84  and  86  are coaxially arranged via the base portion  30 B of the erecting base  30 . The rotation shaft  84  is rotatably fitted to a recessed bearing portion  78 A of the partition wall  78 . The rotation shaft  86  is rotatably fitted to a recessed bearing portion  80 A of the partition wall  80 . Moreover, the rotation shafts  84  and  86  are mounted at the bearing portions  78 A and  80 A respectively with a predetermined backlash amount x in the axial direction of the rotation shafts  84  and  86 . When the rotation shafts  84  and  86  are moved to one side by using the backlash amount x, a portion of one bearing portion of the bearing portions  78 A and  80 A is exposed, and a brush can be easily inserted to the exposed portion, thereby increasing washing efficiency of the bearing portions  78 A and  80 A. 
     Referring to  FIGS.  2  and  3   , an optical system housing chamber  88  is included in the partition wall  78 . An illumination window  90  and an observation window  92  are adjacently disposed at an upper portion of the optical system housing chamber  88 . In addition, the air/water supply nozzle  70  directed to the observation window  92  is provided at the distal end member  28 . The air/water supply nozzle  70  is connected to an air/water supply device (not illustrated) via an air/water supply tube (not illustrated) inserted through the insertion section  24 . By operating the air/water supply button  66  of the operation section  22  illustrated in  FIG.  1   , the air or water is ejected from the air/water supply nozzle  70  toward the observation window  92 . Accordingly, the observation window  92  is washed. 
     An illumination unit (not illustrated) and an imaging unit (not illustrated) are housed in the optical system housing chamber  88 . The illumination unit includes an illumination lens (not illustrated) disposed inside the illumination window  90  and a light guide (not illustrated) arranged such that a distal end surface of the light guide faces the illumination lens. The light guide is disposed to extend from the insertion section  24  via the operation section  22  to the universal cord  46  of the endoscope  10 , and the proximal end thereof is connected to the light source device  16  via the light source connector  50 . Thus, the irradiation light from the light source device  16  is transmitted through the light guide and is emitted from the illumination window  90  to the outside. 
     The above-described imaging unit includes an imaging optical system (not illustrated) disposed inside the observation window  92  and an imaging element (not illustrated) of a complementary metal oxide semiconductor (CMOS) or a charge coupled device (CCD). The imaging element is connected to the processor device  14  via a signal cable (not illustrated) inserted through the insertion section  24  in  FIG.  1   . An imaging signal of a subject image obtained by the imaging unit is output to the processor device  14  via the signal cable, undergoes image processing, and then is displayed as a subject image on the display  18 . 
     Although the description is redundant, the wire  60  is described. Referring to  FIGS.  2  and  3   , the distal end side of the wire  60  is arranged outside a lead-out port  74  and is coupled to the erecting base  30 . The proximal end side of the wire  60  is arranged outside a lead-in port  94  provided in the operation section  22  as illustrated in  FIG.  6   , and is coupled to the movable member  96  (see  FIG.  10   ). The lead-out port  74  is an example of a distal end opening according to the present invention. The lead-in port  94  is an example of a proximal end opening according to the present invention. 
       FIG.  6    is a perspective view of the operation section  22 , and is a perspective view illustrating the other side surface  22 B opposite to the one side surface  22 A of the operation section  22  illustrated in  FIG.  1   . 
     Referring to  FIG.  6   , the lead-in port  94  is provided in the extension part  36  of the operation section  22 . An attachment member  98  is provided at the proximal end of the wire  60  arranged at the outside from the lead-in port  94 . The attachment member  98  is engaged with an engagement hole (described later) of the movable member  96  in an attachable/detachable manner. 
     In this specification, being “engaged in an attachable/detachable manner” includes, like being “engaged in an attachable/detachable manner by a one-touch operation”, that the attachment member  98  can be attached to and detached from the movable member  96  only by the movement of the attachment member  98  relative to the movable member  96  without using another fixing tool (for example, a screw, a bolt, or a nut), and that the attachment member  98  is attached to and detached from the movable member  96  by using another fixing tool. 
     The operation section  22  is provided with the movable member  96 . The movable member  96  is arranged to be exposed to the outside of the operation section  22 . The movable member  96  moves in association with the operation of the erecting operation lever  20  by the erecting operation mechanism  120  (described later). In the embodiment, the movable member  96  is rotatably arranged at the other side surface  22 B opposite to the one side surface  22 A provided with the angle knobs  64 . However, the arrangement position of the movable member  96  with respect to the operation section  22  is not limited, and may be rotatably arranged at a predetermined position of the operation section  22 . The movable member  96  is a driven lever that rotates in association with the rotational operation of the erecting operation lever  20 . 
     The erecting operation mechanism  120  is arranged inside the operation section  22 . The erecting operation mechanism  120  moves the movable member  96  in association with the operation of the erecting operation lever  20 . Thus, when the erecting operation lever  20  is rotationally operated, the movable member  96  moves via the erecting operation mechanism  120 , and the wire  60  (see  FIG.  2   ) coupled to the movable member  96  is pushed/pulled. The erecting operation mechanism  120  will be described later. 
     Next, an engagement structure for engaging the distal end of the wire  60  with the erecting base  30  in an engageable/disengageable manner is described. 
     Referring back to  FIGS.  2  and  3   , the distal end of the wire  60  is provided with an engagement member  100 . Moreover, the erecting base  30  is provided with a housing groove  102  having an opening  104  formed on the side in the X(+) direction. The engagement member  100  is engaged with the housing groove  102  in an engageable/disengageable manner. Accordingly, by housing the engagement member  100  provided at the distal end of the wire  60  in the housing groove  102  via the opening  104 , the distal end of the wire  60  is coupled to the erecting base  30 . 
     In the embodiment, the engagement member  100  is a sphere, and the housing groove  102  is a spherical-surface-shaped concave portion that houses the spherical engagement member  100 . The shapes of the engagement member  100  and the housing groove  102  are not limited to the above-described shapes. However, as long as the engagement member  100  is the sphere and the housing groove  102  is the spherical-surface-shaped concave portion, the sliding resistance between the engagement member  100  and the housing groove  102  generated by the pushing/pulling operation of the wire  60  can be decreased. Accordingly, the pushing/pulling operation of the wire  60  can be smoothly performed. 
     Moreover, the distal end member  28  includes an engagement guide portion  106  connected to the housing groove  102  at the erecting position in  FIG.  3   . The engagement guide portion  106  includes a function of guiding the engagement member  100  led out from the lead-out port  74  to the opening  104  of the housing groove  102 . The lead-out port  74  is provided in the distal end member  28 , and communicates with the lead-in port  94  (see  FIG.  6   ) via the wire channel  62  provided in the insertion section  24 . 
     With the endoscope  10  having such an engagement guide portion  106 , when the wire  60  is led in from the lead-in port  94  while the engagement member  100  is at the head, the engagement member  100  is inserted through the wire channel  62  (see  FIG.  2   ) and is led out to the outside from the lead-out port  74 . The engagement member  100  is guided by the engagement guide portion  106  toward the opening  104  of the housing groove  102  of the erecting base  30  through the ongoing lead-in operation of the wire  60 , and is engaged with the housing groove  102  from the opening  104 . Accordingly, with the endoscope  10  according to the embodiment, the engagement member  100  of the wire  60  can be engaged with the housing groove  102  of the erecting base  30  only by the lead-in operation of the wire  60 . 
       FIG.  7    is an enlarged perspective view when the engagement member  100  is engaged with the housing groove  102  via the engagement guide portion  106 .  FIG.  8    is an explanatory diagram illustrating a successive movement until the engagement member  100  is guided by the engagement guide portion  106  and engaged with the housing groove  102 . 
     Referring to  FIGS.  7  and  8   , the engagement guide portion  106  includes an engagement guide path  108  that guides the engagement member  100  led out from the lead-out port  74  to the opening  104  of the housing groove  102 , and a deformation generation portion  110  connected to the opening  104  of the housing groove  102  in the engagement guide path  108 . The deformation generation portion  110  comes into contact with the engagement member  100  that advances in the Y(+) direction toward the opening  104  in the engagement guide path  108 , and guides the engagement member  100  in the X(+) direction while guiding the engagement member  100  in the Y(+) direction. 
     Accordingly, the distal end side of the wire  60  is elastically deformed in a direction (X(+) direction) to move gradually away from the opening  104  as the engagement member  100  approaches the opening  104  along the engagement guide path  108 . When the engagement member  100  has passed through the deformation generation portion  110 , the engagement member  100  advancing in the engagement guide path  108  moves in the X(−) direction by the resilient force of the wire  60 , and is engaged with the housing groove  102  from the opening  104 . 
     The engagement guide path  108  is formed by cutting a portion of a peripheral surface  28 A of the distal end member  28  into a recessed shape, and is a surface that extends from the lead-out port  74  in the Y(+) direction and that is gradually inclined in the X(+) direction. The deformation generation portion  110  is formed on the distal end side of the engagement guide path  108 . 
     Moreover, a groove  112  is formed in the engagement guide portion  106 . When the engagement member  100  is engaged with the housing groove  102 , the groove  112  allows the distal end side of the wire  60  to fall thereinto and to retract therein. Furthermore, a groove  114  is also formed at the proximal end side of the housing groove  102  of the erecting base  30 . When the engagement member  100  is engaged with the housing groove  102 , the groove  114  allows the distal end side of the wire  60  to fall thereinto and to retract therein. The width dimension of the groove  112  in a direction orthogonal to the paper face of  FIG.  8    is larger than the diameter of the wire  60 , and is smaller than the diameter of the engagement member  100  so that the engagement member  100  which passes through the deformation generation portion  110  does not fall into the groove  112 . The width dimension of the groove  114  in the direction orthogonal to the paper face of  FIG.  8    is larger than the diameter of the wire  60 , and is smaller than the diameter of the engagement member  100  so that the engagement member  100  engaged with the housing groove  102  does not come out in the Y(−) direction. 
     The engagement guide portion  106  has a suitable form for a case where the engagement member  100  is engaged with the housing groove  102  in a state in which the erecting base  30  is located at the erecting position. That is, referring to  FIG.  7   , the housing groove  102  is arranged at a position facing the lead-out port  74  in the state in which the erecting base  30  is located at the erecting position. Thus, by advancing the engagement member  100  straight from the lead-out port  74 , the engagement member  100  can be engaged with the housing groove  102  of the erecting base  30  located at the erecting position, via the engagement guide portion  106 . 
     Next, a detachment structure for detaching the engagement member  100  of the wire  60  engaged with the housing groove  102  of the erecting base  30  from the housing groove  102  is described. 
     The distal end member  28  includes a detachment guide surface  116 . The detachment guide surface  116  is included in an upper surface of the partition wall  80  (see  FIG.  2   ). The detachment guide surface  116  is a guide surface that extends in the X(+) direction and that is inclined in the Z(−) direction (see  FIGS.  2  and  3   ). The detachment guide surface  116  also functions as a surface that guides the wire  60  in a direction in which the engagement member  100  is detached from the inside of the housing groove  102  to the outside of the opening  104  when the wire  60  is operated to be further pushed in a state in which the engagement member  100  is engaged with the housing groove  102  and the erecting base  30  is located at the lying position. 
     With the thus configured detachment structure, an attachment member (described later) provided at the proximal end of the wire  60  is detached from an engagement hole (described later) of the movable member  96 , and then the wire  60  is operated to be pushed from the lead-in port  94  of the extension part  36  to cause the erecting base  30  to be located at the lying position in  FIG.  2    from the erecting position in  FIG.  3   . Then, by further operating the wire  60  to be pushed, the wire  60  is guided in the X(+) direction in which the engagement member  100  is detached from the inside of the housing groove  102  to the outside of the opening  104  by using the detachment guide surface  116  of the distal end member  28 . Accordingly, the engagement member  100  is easily detached to the outside of the opening  104  from the inside of the housing groove  102  by the resilient force of the wire  60 . 
     Next, the erecting operation mechanism  120  illustrated in  FIGS.  9  and  10    is described. 
       FIG.  9    is a configuration diagram illustrating the entire configuration of the erecting operation mechanism  120 .  FIG.  10    is a side view of the erecting operation mechanism  120  in  FIG.  9   .  FIGS.  9  and  10    omit illustration of an exterior case (not illustrated) of the operation section  22 , and illustrate the inside of the operation section  22 . 
     As illustrated in  FIGS.  9  and  10   , the erecting operation mechanism  120  is provided in the operation section  22 . 
     The erecting operation mechanism  120  is also a power transmission mechanism that couples the erecting operation lever  20  and the movable member  96  to each other and that transmits a rotational movement of the erecting operation lever  20  to the movable member  96 . 
     The erecting operation mechanism  120  includes a first conversion mechanism  124  that converts a rotational motion of the erecting operation lever  20  into a linear motion, a wire  126  that is linearly moved by the first conversion mechanism  124 , and a second conversion mechanism  128  that converts the linear motion of the wire  126  into a rotational motion to rotate the movable member  96 . The wire  126  is an example of a drive member according to the present invention. 
     The first conversion mechanism  124  includes a crank member  130  whose proximal end is coupled to the erecting operation lever  20 , a first slider  132  whose proximal end is coupled to the distal end of the crank member  130 , and a second slider  134  whose proximal end is coupled to the distal end of the first slider  132 . 
     The proximal end of the wire  126  is connected to the distal end of the second slider  134 . The distal end of the wire  126  is connected to the second conversion mechanism  128  including a speed reduction mechanism. 
     With the thus configured first conversion mechanism  124 , when the erecting operation lever  20  is rotationally operated, the crank member  130 , the first slider  132 , and the second slider  134  linearly move along the cylinder axis B in association with the rotational operation. Accordingly, the wire  126  linearly moves along the cylinder axis B, and the linear motion is transmitted to the second conversion mechanism  128 . 
     The second conversion mechanism  128  includes a lever  136 , a first gear  138 , a second gear  140 , a third gear  142 , and a fourth gear  144 . The first gear  138 , the second gear  140 , the third gear  142 , and the fourth gear  144  configure the speed reduction mechanism. 
     The lever  136  is rotatably supported by a bracket  146  via a shaft  148 . The distal end of the wire  126  is coupled to the lever  136 . Thus, the lever  136  is rotated around the shaft  148  by the linear motion of the wire  126 . 
     The first gear  138  is provided integrally with the lever  136 , and is rotated around the shaft  148 . The second gear  140  is meshed with the first gear  138 , and is rotatably supported by the bracket  146  via a shaft  150 . The third gear  142  is provided integrally with the second gear  140 , and is provided coaxially with the second gear  140 . The fourth gear  144  is provided coaxially with a drive shaft  152  of the movable member  96 , and is rotatably supported together with the movable member  96  by the bracket  146  via the drive shaft  152 . The fourth gear  144  is meshed with the third gear  142 . 
     With the thus configured second conversion mechanism  128 , when the linear motion of the wire  126  is transmitted to the lever  136 , the first gear  138  is rotationally operated together with the lever  136 , the rotational movement of the first gear  138  is transmitted to the fourth gear  144  via the second gear  140  and the third gear  142 , and hence the fourth gear  144  is rotated. Accordingly, the movable member  96  integrated with the fourth gear  144  is rotated around the drive shaft  152 . 
     Thus, with the thus configured erecting operation mechanism  120 , the rotational operation of the erecting operation lever  20  can be transmitted to the movable member  96  via the first conversion mechanism  124 , the wire  126 , and the second conversion mechanism  128 . Accordingly, the movable member  96  is rotated around the drive shaft  152 . 
     With the erecting operation mechanism  120 , the speed of the rotational movement of the erecting operation lever  20  is reduced by the second conversion mechanism  128  including the speed reduction mechanism, and then the rotational movement is transmitted to the movable member  96 . That is, the rotation angle of leg portions  162  and  164  of the movable member  96  becomes smaller than the rotation angle of the lever  136  that moves by the operation of the erecting operation lever  20 . Accordingly, the force required for operating the erecting operation lever  20  can be further decreased, and the erecting/lying posture of the erecting base  30  can be easily controlled by the erecting operation lever  20 . 
     In the embodiment, the wire  126  is an example of a drive member of the erecting operation mechanism  120  as illustrated in  FIGS.  9  and  10   . Since the wire  126  is used as the drive member, the following advantages are attained. That is, when the linear motion of the second slider  134  is converted into the rotational motion of the lever  136 , the wire  126  has a motion in a curve form (loose), hence a link mechanism is not required to be disposed, and limitation on the space is reduced. When the second slider  134  and the lever  136  are coupled to each other by a link mechanism, a place to which the force escapes is decreased in the erecting operation mechanism  120 . In such a case, by using the wire  126 , the wire  126  is loosened, hence the force can escape, and the load to be applied to the erecting operation mechanism  120  can be decreased. Thus, even when a certain external force is applied to the movable member  96  exposed to the outside of the operation section  22 , the wire  126  is loosened and hence the force can escape, thereby decreasing the load to be applied to the erecting operation mechanism  120 . 
     The shape of the movable member  96  is described here. As illustrated in  FIGS.  15  and  16    (described later), the movable member  96  includes a flat-plate-shaped beam portion  160 , and the leg portions  162  and  164  provided on both ends of the beam portion  160 . The movable member  96  is formed in a U-like shape as a whole. Referring to  FIGS.  9  and  10   , the drive shaft  152  provided on the leg portion  162  side is rotatably supported by the exterior case (not illustrated) of the operation section  22  via an O-ring  166 , and a driven shaft  168  provided on the leg portion  164  side is rotatably supported by the exterior case (not illustrated) via an O-ring (not illustrated). With the O-ring  166  and the other O-ring, the operation section  22  is held watertight. 
     The rotation axes of the drive shaft  152  and the driven shaft  168  of the movable member  96  are set in a direction (X(+)-X(−) direction) perpendicular to the axial direction of the wire  60 . That is, since the movable member  96  is rotatably provided while the direction perpendicular to the axial direction of the wire  60  serves as the rotation axis, the wire  60  can be smoothly pushed/pulled. 
     Next, a coupling structure  170  according to a first embodiment that couples the proximal end of the wire  60  to the movable member  96  is described with reference to  FIGS.  11  to  15   . 
       FIG.  11    is a perspective view when the coupling structure  170  is viewed from the other side surface  22 B of the operation section  22 .  FIG.  12    is a perspective view when the coupling structure  170  illustrated in  FIG.  11    is viewed from the left. 
       FIG.  13    is a perspective view of a wire assembly  172  including the wire  60  and the attachment member  98  provided at the proximal end of the wire  60 .  FIG.  14    is a front view of the attachment member  98 .  FIG.  15    is a perspective view of the extension part  36  illustrating the lead-in port  94  and the movable member  96 . 
       FIGS.  11  to  15    described above are explanatory diagrams for illustrating the coupling structure  170 .  FIGS.  11  and  12    illustrate a state in which the proximal end of the wire  60  and the movable member  96  are coupled by the coupling structure  170 .  FIGS.  13  to  15    illustrate the attachment member  98  and the movable member  96  that configure the coupling structure  170 . 
     As illustrated in  FIG.  15   , the movable member  96  includes an engagement hole  174  with which the attachment member  98  is engaged in an attachable/detachable manner by a one-touch operation. The engagement hole  174  is formed along the longitudinal direction of the beam portion  160  of the movable member  96 , and is configured of a through hole extending through the front and back surfaces of the beam portion  160 . A pair of engagement portions  176  (see  FIG.  14   ) of the attachment member  98  are engaged with the engagement hole  174  in an attachable/detachable manner by a one-touch operation. Accordingly, with the coupling structure  170  according to the first embodiment, the proximal end of the wire  60  and the movable member  96  are coupled to each other outside the operation section  22 . The engagement hole  174  may be a through hole extending through the front and back surfaces of the beam portion  160  or may be a recessed non-through hole not extending through the front and back surfaces of the beam portion  160 . 
     In this specification, being “engaged in an attachable/detachable manner by a one-touch operation” represents that a movement for attachment of the attachment member  98  to the movable member  96  and a movement for detachment of the attachment member  98  from the movable member  96  can be performed only by the movement of the attachment member  98  relative to the movable member  96  without using another fixing tool (for example, a screw, a bolt, or a nut). This is applied to other embodiments (described later). 
     The attachment member  98  illustrated in  FIG.  14    is a substantially triangular plate-shaped body, and has a hole portion  180  at a core portion  178  of a center portion of the attachment member  98 . The proximal end of the wire  60  is coupled to the hole portion  180 . The engagement portions  176  of the attachment member  98  are provided on both sides of the core portion  178  with slit-shaped cut portions  182  interposed between the engagement portions  176  and the core portion  178 . The engagement portions  176  are provided with a pair of elastic deformation portions  184  that are elastically deformed and engaged with the engagement hole  174 . The elastic deformation portions  184  have a pair of claw portions  186  at edge portions  175  (see  FIGS.  15  and  16   ) on both sides in the longitudinal direction of the engagement hole  174 . The pair of claw portions  186  are displaced in directions to move toward each other by elastic deformation of the pair of elastic deformation portions  184  when the engagement portions  176  are engaged with or disengaged from the engagement hole  174 . 
     Next, the coupling procedure of the proximal end of the wire  60  and the movable member  96  to each other with the coupling structure  170  according to the first embodiment is described with reference to  FIGS.  16  to  18   . 
     Before the proximal end of the wire  60  and the movable member  96  are coupled to each other, the distal end of the wire  60  is coupled to the erecting base  30 . 
       FIG.  16    illustrates a state in which the wire  60  is inserted from the lead-in port  94  while the engagement member  100  (see  FIG.  13   ) is at the head. With the insertion operation of the wire  60 , the distal end of the wire  60  is coupled to the erecting base  30 . 
     That is, in the state in which the erecting base  30  is located at the erecting position (see  FIG.  3   ), referring to  FIG.  16   , when the wire  60  is led in from the lead-in port  94  while the engagement member  100  is at the head, the engagement member  100  is inserted through the wire channel  62  (see  FIG.  2   ) and is led out to the outside from the lead-out port  74 . The engagement member  100  is guided by the engagement guide portion  106  in  FIG.  3    toward the opening  104  of the housing groove  102  of the erecting base  30  through the ongoing lead-in operation of the wire  60 , and is engaged with the housing groove  102  from the opening  104 . Accordingly, the distal end of the wire  60  is coupled to the erecting base  30 . 
       FIG.  17    illustrates the state of the attachment member  98  in a state in which the distal end of the wire  60  is coupled to the erecting base  30 . In this state, tapered portions  187  located below the claw portions  186  are brought into contact with edges on both sides of the engagement hole  174  and are pushed into the engagement hole  174 . With this movement, the distance between the claw portions  186  is decreased, the claw portions  186  are latched to the edge portions  175  on both sides of the engagement hole  174 , and the attachment member  98  is coupled to the movable member  96  referring to the coupling diagram of  FIG.  18   . 
     Accordingly, with the coupling structure  170  according to the first embodiment, the movement for attachment of the attachment member  98  to the movable member  96  can be performed only by the movement of the attachment member  98  relative to the movable member  96 . That is, with the coupling structure  170  according to the first embodiment, the attachment member  98  can be engaged with the movable member  96  by a one-touch operation. 
     When the attachment member  98  is mounted at the movable member  96 , the pair of engagement portions  176  of the attachment member  98  can be pinched with fingers of a hand to narrow the distance between the claw portions  186  to be smaller than the dimension in the longitudinal direction of the engagement hole  174 . That is, the pair of elastic deformation portions  184  are displaced in directions to move toward each other by elastic deformation. After the claw portions  186  are inserted into the engagement hole  174 , by relaxing the force of the fingers of the hand to expand the distance between the claw portions  186 , the claw portions  186  are latched to the edge portions  175  on both sides of the engagement hole  174 . Accordingly, the attachment member  98  is engaged with the movable member  96  by a one-touch operation. 
     Then, when the erecting operation lever  20  in  FIG.  1    is operated, as illustrated in the movement explanatory diagram of the movable member  96  in  FIG.  12   , the movable member  96  moves in a direction of arrow C or arrow D. Then, in association with the movement of the movable member  96 , the wire  60  is operated to be pushed/pulled by the movable member  96  via the attachment member  98 . Accordingly, the erecting base  30  is rotated between the erecting position and the lying position. 
     According to the embodiment, the engagement hole  174  is formed in the movable member  96  and the engagement portions  176  are formed at the attachment member  98 . However, the engagement portions  176  may be formed at the movable member  96  and the engagement hole  174  may be formed in the attachment member  98 . That is, the engagement hole  174  may be provided in one of the movable member  96  and the attachment member  98 , and the engagement portions  176  that are engaged with the engagement hole  174  in an attachable/detachable manner by a one-touch operation may be provided at the other one. The claw portions  186  may not be provided on the sides in the longitudinal direction of the beam portion  160  of the movable member  96 , and may be provided on the sides in the transverse direction of the beam portion  160 . The engagement hole  174  may be two engagement holes independently formed in the longitudinal direction of the beam portion  160 . 
     The endoscope  10  is used for one of various inspections or one of various treatments. Thereafter, when the endoscope  10  is washed, the following works are performed. 
     First, the cap  76  illustrated in  FIG.  2    is removed from the distal end member  28 . Then, the engagement portions  176  of the attachment member  98  are removed from the engagement hole  174  (see  FIG.  15   ) of the movable member  96 , and the wire  60  is removed from the movable member  96 . Then, the wire  60  is operated to be pushed from the lead-in port  94  of the extension part  36  to cause the erecting base  30  to be located at the lying position in  FIG.  2    from the erecting position in  FIG.  3   . Then, by further operating the wire  60  to be pushed, the engagement member  100  is detached to the outside of the opening  104  from the inside of the housing groove  102 . With the works, the distal end of the wire  60  is removed from the erecting base  30 . Then, the wire  60  is pulled out from the lead-in port  94 , and the wire channel  62  is made empty. Then, the distal end member  28 , the erecting base  30 , and the wire channel  62  of the wire  60  are washed. 
     In the work of removing the distal end of the wire  60  from the erecting base  30 , in the coupling structure  170  according to the first embodiment, since the attachment member  98  is coupled to the movable member  96  outside the operation section  22 , the attachment member  98  can be easily removed from the movable member  96 . Specifically, the pair of engagement portions  176  of the attachment member  98  are pinched with fingers of a hand to narrow the distance between the claw portions  186  to be smaller than the dimension in the longitudinal direction of the engagement hole  174 . Then, the claw portions  186  are pulled out from the engagement hole  174 . 
     Accordingly, with the coupling structure  170  according to the first embodiment, the movement for detachment of the attachment member  98  from the movable member  96  can be performed only by the movement of the attachment member  98  relative to the movable member  96 . That is, with the coupling structure  170  according to the first embodiment, the attachment member  98  can be detached from the movable member  96  by a one-touch operation. 
     As described above, with the coupling structure  170  according to the first embodiment, after the distal end of the wire  60  is coupled to the erecting base  30 , merely by engaging the engagement portions  176  of the attachment member  98  with the engagement hole  174  of the movable member  96  outside the operation section  22 , the proximal end of the wire  60  can be coupled to the movable member  96 . When the endoscope  10  is washed, to remove the proximal end of the wire  60  from the movable member  96 , merely by detaching the attachment member  98  from the engagement hole  174  of the movable member  96  outside the operation section  22 , the proximal end of the wire  60  can be removed from the movable member  96 . 
     Thus, with the coupling structure  170  according to the first embodiment, compared with the endoscope of JP1994-315458A (JP-H6-315458A) that performs the attachment/detachment work of the proximal end of the wire to/from the connecting tool in the operation section and the endoscope of EP1759626B in which the distal end of the cable cord is mounted at the collet and the nut in an attachable/detachable manner, the attachment/detachment operation of the proximal end of the wire  60  to/from the movable member  96  can be easily performed. 
     In the above-described embodiment, the wire  60  is pulled out from the lead-in port  94 . However, the wire  60  may be pulled out from the lead-out port  74  of the distal end member  28 . In this case, by removing the attachment member  98  from the proximal end of the wire  60  before the wire  60  is pulled out, the wire  60  can be pulled out from the lead-out port  74 . 
       FIG.  19    is a perspective view illustrating a modification of the coupling structure  170  according to the first embodiment illustrated in  FIGS.  11  to  18   . 
     A coupling structure  170 A according to a modification illustrated in  FIG.  19    is described with the same reference signs applied to the same or similar members as or to those of the coupling structure  170  illustrated in  FIGS.  11  to  18   . 
     An engagement hole  174 A formed in the movable member  96  is a circular through hole. An engagement portion  176 A of an attachment member  98 A has a tubular portion  177  that is inserted into the engagement hole  174 A. An elastic deformation portion of the attachment member  98 A is configured of a slotted portion  184 A provided at a distal end portion of the tubular portion  177 . A claw portion  186 A is formed at the outer peripheral surface of the slotted portion  184 A. 
     With the thus configured coupling structure  170 A, when the slotted portion  184 A of the tubular portion  177  is inserted into the engagement hole  174 A, the diameter of the slotted portion  184 A is decreased by elastic deformation. Accordingly, after the slotted portion  184 A is passing through the engagement hole  174 A and then the slotted portion  184 A has passed through the engagement hole  174 A, the diameter of the slotted portion  184 A is restored to the original diameter. Thus, referring to the sectional view of the coupling structure  170 A illustrated in  FIG.  20   , the claw portion  186 A of the slotted portion  184 A is engaged with a back surface  160 A of the beam portion  160  of the movable member  96 . The attachment member  98 A is engaged with the movable member  96  by a one-touch operation. 
     Even with the coupling structure  170 A, the attachment/detachment work of the attachment member  98 A to/from the movable member  96  is performed outside the operation section  22  similarly to the coupling structure  170 . The attachment work is of merely inserting the engagement portion  176 A into the engagement hole  174 A. With the attachment work, the proximal end of the wire  60  can be easily coupled to the movable member  96  via the attachment member  98 A. 
     When the attachment member  98 A is removed from the movable member  96 , the slotted portion  184 A is pinched with fingers to decrease the diameter of the slotted portion  184 A. Then, the slotted portion  184 A is pulled out from the engagement hole  174 A. 
     Accordingly, even with the coupling structure  170 A according to the modification, the movement for attachment of the attachment member  98 A to the movable member  96  and the movement for detachment of the attachment member  98 A from the movable member  96  can be performed only by the movement of the attachment member  98 A relative to the movable member  96  similarly to the coupling structure  170 . That is, with the coupling structure  170 A, the attachment member  98 A is engaged with the movable member  96  in an attachable/detachable manner by a one-touch operation. 
       FIG.  21    is a sectional view illustrating a state in which a valve body  95  is mounted at the lead-in port  94 . In the embodiment, since the proximal end of the wire  60  is arranged outside the lead-in port  94 , the valve body  95  is preferably mounted at the lead-in port  94 . Accordingly, liquid in a body cavity which flows backward from the lead-out port  74  of the distal end member  28  via the wire channel  62  can be prevented from leaking to the outside from the lead-in port  94 . 
     Next, the interference prevention section  300  is described. The interface prevention section  300  is provided to prevent a phenomenon in which a locking device  302  (described later) interferes with the movable member  96  and limits the movement of the movable member  96  from occurring. 
     Regarding a duodenum endoscope, when a treatment is performed in a duct, such as the bile duct or the pancreatic duct, the insertion section  24  is inserted to a position close to the Vater papilla of the duodenum, and a treatment tool is inserted from the treatment tool lead-in port  42  of the operation section  22 . When the treatment tool is inserted, first, a guide wire is inserted through the treatment tool channel  58  of the insertion section  24 , and the guide wire is inserted from the Vater papilla into the bile duct or the pancreatic duct. Then the treatment tool is inserted into the bile duct or the pancreatic duct while the treatment tool is guided by the guide wire. When the treatment tool is changed, a treatment tool is inserted along the guide wire, hence the treatment tool can be inserted to a position at which the treatment is currently performed, and a burden on the operator during the replacement work of the treatment tool can be reduced. 
     However, when the guide wire is not fixed during the replacement of the treatment tool, the guide wire may move and may come out from the Vater papilla. If the guide wire comes out from the Vater papilla, the treatment tool after the replacement is no longer guided to the treatment position. Thus, a guide wire locking device  302  illustrated in  FIG.  22    is used in order to fix the guide wire. The guide wire locking device  302  is configured of a main body portion  308  that has a slit  304  and a lateral claw  306  and that fixes the guide wire, and a band portion  310  that is wound around the endoscope  10  and hence that fixes the guide wire locking device  302  to the endoscope  10 . 
     In this embodiment, since the movable member  96  is arranged to be exposed to the outside of the operation section  22 , the attachment/detachment operation of the proximal end of the wire  60  to/from the movable member  96  can be easily performed. However, depending on the mount position of the guide wire locking device  302 , the guide wire locking device  302  may limit the movement of the movable member  96 . Thus, when the guide wire locking device  302  is mounted, it is required to mount the guide wire locking device  302  at a position at which the guide wire locking device  302  does not interfere with the movement of the movable member  96 . Since the interference prevention section  300  is provided and the guide wire locking device  302  is mounted at the proximal end side of the operation section  22  with respect to the interference prevention section  300 , the guide wire locking device  302  can be prevented from interfering with the movable member  96 . 
       FIG.  23    is an illustration when the guide wire locking device  302  is mounted at the endoscope  10  and a guide wire  312  is fixed to the guide wire locking device  302 .  FIG.  24    is an enlarged view when the guide wire locking device  302  is mounted at the endoscope  10 . The guide wire locking device  302  is fixed to the endoscope  10  by winding the band portion  310  around an area between the treatment tool lead-in port  42  provided in the holding part  34  and the interference prevention section  300 . Moreover, the guide wire  312  is fixed by hooking the guide wire  312  to the slit (not illustrated in  FIG.  23   ) of the main body portion  308  and to the lateral claw  306 . Accordingly, the guide wire  312  is prevented from moving during the replacement of the treatment tool  56 . 
     The interference prevention section  300  is configured of an interference prevention wall  40  vertically extending from an outer wall surface of the operation section  22 . The movable member  96  moves in the direction of arrow C or arrow D as described above. The interference prevention wall  40  is provided at a position at which the movable member  96  or the attachment member  98  does not come into contact with the interference prevention wall  40  when the movable member  96  moves in the direction of arrow C. The interference prevention wall  40  may be, as illustrated in  FIG.  24   , a flange-shaped interference prevention plate  40 A formed over the entire circumference of the outer wall surface of the operation section  22 . The interference prevention plate  40 A preferably has a height at which the band portion  310  of the guide wire locking device  302  is not able to be wound around the operation section  22  of the endoscope  10 . As illustrated in  FIG.  24   , the interference prevention wall  40  may have a height H 1  of about 10 mm when being formed in a ring shape around the outer wall surface of the operation section  22 . When the interference prevention wall  40  is formed around the operation section  22 , the diameter of the interference prevention section  300  including the operation section  22  and the interference prevention wall  40  is set to 40 mm or larger, so that the band portion  310  of the guide wire locking device  302  is not wound around the operation section  22 . 
       FIGS.  25  to  29    illustrate modifications of an interference prevention wall. An interference prevention wall is not particularly limited as long as the band portion  310  of the guide wire locking device  302  is not able to be mounted at a position at which the interference prevention wall is formed. An interference prevention wall  340  illustrated in  FIG.  25    is configured of an interference prevention plate  340 A formed in a ring shape around the outer wall surface of the operation section  22  like the interference prevention wall  40  illustrated in  FIG.  24   . The interference prevention wall  340  is formed in a tapered shape in which the interference prevention plate  340 A is widened from the proximal end side toward the distal end side of the operation section  22 . 
     As illustrated in  FIG.  26   , an interference prevention wall  342  may vertically extend from a portion of an outer wall of the operation section  22 . When the interference prevention wall  342  is provided at a portion of the periphery of the operation section  22 , the height of the interference prevention wall  342  from the outer wall surface of the operation section  22  is preferably increased, and the interference prevention wall  342  may have a height H 2  of about 16 mm. 
       FIGS.  27  and  28    illustrate further modifications of an interference prevention wall. An interference prevention wall  344  illustrated in  FIG.  27    has an interference prevention plate  344 A around the outer wall surface of the operation section  22 . The height of the interference prevention plate  344 A on the surface side provided with the movable member  96  from the outer wall surface of the operation section  22  is increased. Moreover, a portion of the interference prevention plate  344 A has a cut portion  346 . An interference prevention wall  348  illustrated in  FIG.  28    has an interference prevention plate  348 A around the outer wall surface of the operation section  22 . The height of the interference prevention plate  348 A on the surface side provided with the movable member  96  from the outer wall surface of the operation section  22  is increased. The interference prevention plate  348 A may be provided with an opening portion  350 . 
       FIG.  29    illustrates a further modification of an interference prevention wall. An interference prevention wall  352  illustrated in  FIG.  29    is formed by arranging a plurality of interference prevention bodies  352 B around the outer wall surface of the operation section  22 . The interference prevention bodies  352 B are spaced apart from one another. The number of the interference prevention bodies  352 B and the number of gaps of the interference prevention bodies  352 B are not particularly limited as long as the band portion  310  of the guide wire locking device  302  is not able to be mounted. 
     Thus, since the interference prevention section  300  is provided, when the guide wire locking device  302  is mounted at the operation section  22  of the endoscope  10 , the position of the guide wire locking device  302  can be a position at which the guide wire locking device  302  does not interfere with the movement of the movable member  96 . Thus, the movement of the erecting base  30  is not limited by the movement of the movable member  96 , and the erecting operation can be reliably performed. 
       FIGS.  30  and  31    illustrate a further modification of an interference prevention section  301 .  FIG.  30    is a configuration diagram of an endoscope system including an endoscope having the interference prevention section  301 .  FIG.  31    is a perspective view of the interference prevention section  301 . 
     In the interference prevention section  301 , an extension part  354  has an outside diameter that is larger than the outside diameter of the holding part  34 , and the interference prevention section  301  has a step portion  356  between the extension part  354  and the holding part  34 . The outside diameter of the holding part  34  is an outside diameter at a position on the most distal end side of the holding part  34  and at the boundary between the extension part  354  and the holding part  34 . The outside diameter of the extension part  354  is a size with which the band portion  310  of the guide wire locking device  302  is not able to be mounted. Moreover, the distance from the position at which the movable member  96  is provided to the holding part  34  is a distance larger than the movement range of the movable member  96 . Accordingly, the guide wire locking device  302  can be prevented from being mounted in the movement range of the movable member  96 . Moreover, the guide wire locking device  302  mounted at the holding part  34  can be prevented from interfering with the movable member  96 , and can be prevented from limiting the movement of the erecting base  30 . The distance from the position at which the movable member  96  is provided to the holding part  34  is a distance that is the shortest distance from the rotation axis of the movable member  96  to the boundary between the holding part  34  and the extension part  354 . 
     Next, a coupling structure  210  according to a second embodiment is described with reference to  FIGS.  32  to  34   . 
       FIG.  32    is a perspective view of the coupling structure  210 .  FIG.  33    is an assembly perspective view of the coupling structure  210 .  FIG.  34    is a main-part sectional view of the coupling structure  210 . The coupling structure  210  is described with the same reference signs applied to the same or similar members as or to those of the coupling structure  170  illustrated in  FIGS.  11  to  18   . 
     The coupling structure  210  is configured of a movable member  96  and an attachment member  212 . 
     Referring to  FIG.  33   , an engagement hole  214  is provided in a beam portion  160  of the movable member  96 , and an engagement portion  216  that is engaged with the engagement hole  214  in an attachable/detachable manner by a one-touch operation is provided at the attachment member  212 . The attachment member  212  is configured of a pinch portion  218  and a shaft portion  220  configuring the engagement portion  216 . The proximal end of the wire  60  is coupled to a hole portion  222  formed in the shaft portion  220 . 
     The shape of the engagement hole  214  is described here.  FIG.  35    is a plan view of the engagement hole  214 , and illustrating a state in which the shape of the engagement portion  216  is superposed on the shape of the engagement hole  214 . 
     The engagement hole  214  has a small width portion  224  having a diameter a and a large width portion  226  having a diameter b that is larger than the diameter a. In the embodiment, a first width according to the present invention is described as the diameter a, and a second width according to the present invention is described as the diameter b. As illustrated in  FIG.  35   , a line CL connecting the center of the small width portion  224  and the center of the large width portion  226  is a curved line. The line CL defines a substantial arc centered on the lead-in port  94  (not illustrated). The arrangement of the small width portion  224  and the large width portion  226  makes an operation easy when the attachment member  212  is engaged with the engagement hole  214 . This will be described later. 
     The engagement portion  216  of the attachment member  212  illustrated in  FIG.  33    has the shaft portion  220  having an outside diameter c that is equal to or smaller than the diameter a in  FIG.  35   , and a large diameter portion  228  provided at the distal end of the shaft portion  220 . The large diameter portion  228  has an outside diameter d that is larger than the diameter a and smaller than the diameter b. The large diameter portion  228  functions as a fall prevention member that restricts detachment of the shaft portion  220  from the small width portion  224  in the axial direction of the shaft portion  220 . To stably hold the shaft portion  220 , the difference between the diameter a and the outside diameter c is preferably small. 
     The engagement operation is described. Since the large width portion  226  of the engagement hole  214  is larger than the large diameter portion  228 , the engagement portion  216  of the attachment member  212  can be easily inserted into the engagement hole  214 . Then, the attachment member  212  is slid from the large width portion  226  to the small width portion  224 . At this time, as illustrated in  FIG.  32   , the attachment member  212  is fixed to the wire  60 , and hence the attachment member  212  moves on a substantially arc-shaped locus centered on the lead-in port  94 . Since the small width portion  224  and the large width portion  226  are arranged in a substantially arc form as described above, the attachment member  212  can smoothly slide between the small width portion  224  and the large width portion  226 . Furthermore, when the attachment member  212  is located at the small width portion  224 , a tension can be applied to the wire  60 . 
     The engagement hole  214  has a frictional resistance portion  230  between the small width portion  224  and the large width portion  226 . The frictional resistance portion  230  is provided at an opening entrance portion of the small width portion  224 . The frictional resistance portion  230  can restrict unintentional sliding of the shaft portion  220  inserted into the small width portion  224 , from the small width portion  224  to the large width portion  226 . The frictional resistance portion  230  is formed to protrude from each of mutually facing wall surfaces of the engagement hole  214 . 
     Even with the thus configured coupling structure  210 , the attachment/detachment work of the attachment member  212  to/from the movable member  96  is performed outside the operation section  22  similarly to the coupling structure  170 . The attachment work is of merely inserting the engagement portion  216  into the large width portion  226  of the engagement hole  214 , sliding the engagement portion  216  toward the small width portion  224 , and engaging the engagement portion  216  with the small width portion  224 . Accordingly, the attachment member  212  can be engaged with the movable member  96  by a one-touch operation. With the attachment work, the proximal end of the wire  60  can be easily coupled to the movable member  96  via the attachment member  212 . 
     When the engagement portion  216  is slid from the large width portion  226  toward the small width portion  224 , the shaft portion  220  comes into contact with the frictional resistance portion  230 . However, the engagement portion  216  can be properly engaged with the small width portion  224  by the force of sliding the engagement portion  216 . 
     Moreover, in a state in which the engagement portion  216  is engaged with the small width portion  224 , the large diameter portion  228  prevents the shaft portion  220  from being detached from the small width portion  224  in the axial direction of the shaft portion  220 . Furthermore, since the shaft portion  220  comes into contact with the frictional resistance portion  230 , sliding of the engagement portion  216  from the small width portion  224  to the large width portion  226  is restricted. Accordingly, the attachment member  212  can be reliably coupled to the movable member  96 . 
     When the endoscope  10  is washed, to remove the attachment member  212  from the movable member  96 , the engagement portion  216  of the attachment member  212  is slid from the small width portion  224  to the large width portion  226 , and the engagement portion  216  is pulled out from the large width portion  226 . Accordingly, the attachment member  212  is detached from the movable member  96  by a one-touch operation. 
     Thus, with the coupling structure  210  according to the second embodiment, compared with the endoscope of JP1994-315458A (JP-H6-315458A) and the endoscope of EP1759626B, the attachment/detachment operation of the proximal end of the wire  60  to/from the movable member  96  can be easily performed. 
     In  FIG.  35   , the engagement hole  214  including the frictional resistance portion  230  is illustrated as an example; however, the engagement hole  214  may not include the frictional resistance portion  230 . 
     Next, a coupling structure  232  according to a third embodiment is described with reference to  FIGS.  36  and  37   . 
       FIG.  36    is an assembly perspective view of the coupling structure  232 .  FIG.  37    is a plan view of an engagement hole  214  formed in a movable member  96 , and illustrating a state in which the shape of an engagement portion  236  of an attachment member  234  is superposed on the shape of the engagement hole  214 . The coupling structure  232  is described with the same reference signs applied to the same or similar members as or to those of the coupling structure  210  illustrated in  FIGS.  32  to  35   . 
     As illustrated in  FIG.  37   , the engagement hole  214  has a small width portion  224  having a diameter a and a large width portion  226  having a diameter b that is larger than the diameter a. The small width portion  224  and the large width portion  226  have a positional relationship similar to that illustrated in  FIG.  25   . 
     The engagement portion  236  of the attachment member  234  illustrated in  FIG.  36    has a shaft portion  220  having an outside diameter c that is equal to or smaller than the diameter a, and a large diameter portion  238  provided at the distal end of the shaft portion  220  and having an outside diameter f that is larger than the diameter b. A plurality of (for example, four) slotting grooves  237  (see  FIG.  36   ) are formed in the large diameter portion  238 . When the large diameter portion  238  is inserted into the large width portion  226 , the large diameter portion  238  is elastically deformed by the plurality of slotting grooves  237  and the diameter of the large diameter portion  238  is decreased. To stably hold the shaft portion  220 , the difference between the diameter a and the outside diameter c is preferably small. 
     Even with the thus configured coupling structure  232 , the attachment/detachment work of the attachment member  234  to/from the movable member  96  is performed outside the operation section  22  similarly to the coupling structure  210 . The attachment work is of first fitting the large diameter portion  238  into the large width portion  226  of the engagement hole  214 . At this time, the large diameter portion  238  is elastically deformed by the plurality of slotting grooves  237  and the diameter of the large diameter portion  238  is decreased. Accordingly, after the large diameter portion  238  is passing through the large width portion  226  and then the large diameter portion  238  has passed through the large width portion  226 , the diameter of the large diameter portion  238  is restored to the original diameter. Thus, the large diameter portion  238  is engaged with a back surface  160 A of a beam portion  160  of the movable member  96 . The attachment member  234  is prevented from coming out from the movable member  96 . 
     Then, the engagement portion  236  is slid toward the small width portion  224 , and the engagement portion  216  is engaged with the small width portion  224 . Accordingly, the attachment member  234  can be engaged with the movable member  96  by a one-touch operation. With the attachment work, the proximal end of the wire  60  can be easily coupled to the movable member  96  via the attachment member  234 . 
     Moreover, in a state in which the engagement portion  236  is engaged with the small width portion  224 , the large diameter portion  238  prevents the shaft portion  220  from being detached from the small width portion  224  in the axial direction of the shaft portion  220 . Furthermore, since the shaft portion  220  comes into contact with the frictional resistance portion  230 , sliding of the engagement portion  236  from the small width portion  224  to the large width portion  226  is restricted. Accordingly, the attachment member  234  can be reliably coupled to the movable member  96 . 
     When the endoscope  10  is washed, to remove the attachment member  234  from the movable member  96 , the engagement portion  236  of the attachment member  234  is slid from the small width portion  224  to the large width portion  226 , then the large diameter portion  238  is pinched with fingers to decrease the diameter of the large diameter portion  238 , and the large diameter portion  238  is pulled out from the large width portion  226 . Accordingly, the attachment member  234  is detached from the movable member  96  by a one-touch operation. 
     Thus, with the coupling structure  232  according to the third embodiment, compared with the endoscope of JP1994-315458A (JP-H6-315458A) and the endoscope of EP1759626B, the attachment/detachment operation of the proximal end of the wire  60  to/from the movable member  96  can be easily performed. 
     In  FIG.  37   , the engagement hole  214  including the frictional resistance portion  230  is illustrated as an example; however, the engagement hole  214  may not include the frictional resistance portion  230 . 
     Next, a coupling structure  240  according to a fourth embodiment is described with reference to  FIGS.  38  and  39   . 
       FIG.  38    is a perspective view of the coupling structure  240 .  FIG.  39    is an assembly perspective view of the coupling structure  240 . The coupling structure  240  is described with the same reference signs applied to the same or similar members as or to those of the coupling structure  170  illustrated in  FIGS.  11  to  18   . 
     The coupling structure  240  is configured of a movable member  242  and an attachment member  244 . 
     The movable member  242  is configured of a leg portion  162 , a leg portion  164 , and a cylindrical body  246  that couples the leg portion  162  and the leg portion  164  to each other. The cylindrical body  246  extends in a direction (X(+)-X(−) direction) perpendicular to the axial direction of the wire  60 . Moreover, as illustrated in  FIGS.  38  and  39   , U-shaped grooves  248  and  250  configuring a rotation restriction stopper are formed in upper end portions of the leg portion  162  and the leg portion  164 . 
     The proximal end of the wire  60  is coupled to the attachment member  244 . The attachment member  244  is configured of a ring-shaped body  252  that is rotatably engaged with the outer periphery of the cylindrical body  246 , and pins  254  and  256  that configure the rotation restriction stopper together with the grooves  248  and  250 . The ring-shaped body  252  has a C-like shape in a section orthogonal to the longitudinal direction. By pressing a slit  253  that is formed in the ring-shaped body  252  in the longitudinal direction against the cylindrical body  246 , the diameter of the ring-shaped body  252  is increased and is engaged with the cylindrical body  246  by a one-touch operation. 
     Even with the thus configured coupling structure  240 , the attachment/detachment work of the attachment member  244  to/from the movable member  242  is performed outside the operation section  22  similarly to the coupling structures  170  and  210 . The attachment work is of pressing the slit  253  of the ring-shaped body  252  of the attachment member  244  against the cylindrical body  246  of the movable member  242 . With the work, the attachment member  244  is engaged with the movable member  242  by a one-touch operation. Accordingly, the proximal end of the wire  60  can be reliably coupled to the movable member  242  via the attachment member  244 . 
     Moreover, when the ring-shaped body  252  is engaged with the cylindrical body  246 , the pin  254  is engaged with the groove  248  and the pin  256  is engaged with the groove  250  simultaneously. When the wire  60  is operated to be pushed/pulled by the movable member  242 , the ring-shaped body  252  can be prevented from being rotated relative to the cylindrical body  246 . Accordingly, the pushing/pulling operation of the wire  60  can be smoothly performed. 
     When the endoscope  10  is washed, to remove the attachment member  244  from the movable member  242 , the attachment member  244  is pulled in a direction in which the pins  254  and  256  are removed from the grooves  248  and  250 , hence the ring-shaped body  252  is pushed by the cylindrical body  246 , the diameter of the ring-shaped body  252  is increased, and the ring-shaped body  252  is removed from the cylindrical body  246 . Accordingly, the attachment member  244  is detached from the movable member  242  by a one-touch operation. 
     Thus, with the coupling structure  240  according to the fourth embodiment, compared with the endoscope of JP1994-315458A (JP-H6-315458A) and the endoscope of EP1759626B, the attachment/detachment operation of the proximal end of the wire  60  to/from the movable member  242  can be easily performed. 
     In the above-described embodiment, the cylindrical body  246  is provided at the movable member  242 , and the ring-shaped body  252  is provided at the attachment member  244 . However, the cylindrical body  246  may be provided at one of the movable member  242  and the attachment member  244 , and the ring-shaped body  252  may be provided at the other one. 
     In the above-described embodiments, the wire  126  is an example of a drive member of the erecting operation mechanism  120  as illustrated in  FIGS.  9  and  10   . However, a link mechanism may be employed instead of the wire  126 . 
       FIG.  40    illustrates a main-part structure in which a first slider  132  and a lever  136  are coupled to each other by using a link sheet metal  260  serving as a link mechanism.  FIG.  41    is a movement explanatory diagram of the link mechanism in  FIG.  40   . 
     As illustrated in  FIGS.  40  and  41   , the distal end of the link sheet metal  260  is rotatably coupled to the proximal end of the first slider  132  via a pin  262 , and the proximal end of the link sheet metal  260  is rotatably coupled to the lever  136  via a pin  264 . 
     Accordingly, when the erecting operation lever  20  illustrated in  FIGS.  9  and  10    is rotated, a straight advancement motion of the first slider  132  can be transmitted to the lever  136  via the link sheet metal  260  serving as the link mechanism. Thus, the lever  136  is rotated in a rotation range from  FIG.  40    to  FIG.  41   . The resultant rotational force can be transmitted to, for example, the movable member  96  illustrated in  FIGS.  9  and  10   . 
     In the above-described embodiments, a duodenum endoscope is described as an example of the endoscope  10 . However, the present invention can be applied to any one of various endoscopes, such as an ultrasonic endoscope, as long as the endoscope includes an erecting base that adjusts a lead-out direction of a treatment tool, at a distal end part of an insertion section. 
     REFERENCE SIGNS LIST 
     
         
         
           
               10  endoscope 
               12  endoscope system 
               14  processor device 
               16  light source device 
               18  display 
               20  erecting operation lever 
               22  operation section 
               22 A one side surface 
               22 B the other side surface 
               24  insertion section 
               26  distal end part 
               28  distal end member 
               28 A peripheral surface 
               30  erecting base 
               30 A guide surface 
               30 B base portion 
               32  operation section main body 
               34  holding part 
               36  extension part 
               38  break prevention pipe 
               38 A proximal end portion 
               40  interference prevention wall 
               40 A interference prevention plate 
               42  treatment tool lead-in port 
               44  mount portion 
               44 A distal end portion 
               46  universal cord 
               48  electric connector 
               50  light source connector 
               52  bending part 
               54  soft part 
               56  treatment tool 
               56 A distal end portion 
               58  treatment tool channel 
               60  wire 
               62  wire channel 
               64  angle knob 
               66  air/water supply button 
               68  suction button 
               70  air/water supply nozzle 
               72  treatment tool lead-out port 
               74  lead-out port 
               76  cap 
               76 A opening window 
               78  partition wall 
               78 A bearing portion 
               80  partition wall 
               80 A bearing portion 
               82  erecting base housing chamber 
               84  rotation shaft 
               86  rotation shaft 
               88  optical system housing chamber 
               90  illumination window 
               92  observation window 
               94  lead-in port 
               95  valve body 
               96  movable member 
               98  attachment member 
               98 A attachment member 
               100  engagement member 
               102  housing groove 
               104  opening 
               106  engagement guide portion 
               108  engagement guide path 
               110  deformation generation portion 
               112  groove 
               114  groove 
               116  detachment guide surface 
               120  erecting operation mechanism 
               124  first conversion mechanism 
               126  wire 
               128  second conversion mechanism 
               130  crank member 
               132  first slider 
               134  second slider 
               136  lever 
               138  first gear 
               140  second gear 
               142  third gear 
               144  fourth gear 
               146  bracket 
               148  shaft 
               150  shaft 
               152  drive shaft 
               160  beam portion 
               160 A back surface 
               162  leg portion 
               164  leg portion 
               166  O-ring 
               168  driven shaft 
               170  coupling structure 
               170 A coupling structure 
               172  wire assembly 
               174  engagement hole 
               174 A engagement hole 
               175  edge portion 
               176  engagement portion 
               176 A engagement portion 
               177  tubular portion 
               178  core portion 
               180  hole portion 
               182  cut portion 
               184  elastic deformation portion 
               184 A slotted portion 
               186  claw portion 
               186 A claw portion 
               187  tapered portion 
               200  branch pipe 
               202  distal end pipe 
               204  pipe line 
               206  pipe line 
               208  suction pipe 
               210  coupling structure 
               212  attachment member 
               214  engagement hole 
               216  engagement portion 
               218  pinch portion 
               220  shaft portion 
               222  hole portion 
               224  small width portion 
               226  large width portion 
               228  large diameter portion 
               230  frictional resistance portion 
               232  coupling structure 
               234  attachment member 
               236  engagement portion 
               237  slotting groove 
               238  large diameter portion 
               240  coupling structure 
               242  movable member 
               244  attachment member 
               246  cylindrical body 
               248  groove 
               250  groove 
               252  ring-shaped body 
               254  pin 
               256  pin 
               260  link sheet metal 
               262  pin 
               264  pin 
               300  interference prevention section 
               301  interference prevention section 
               302  guide wire locking device 
               304  slit 
               306  lateral claw 
               308  main body portion 
               310  band portion 
               312  guide wire 
               340  interference prevention wall 
               340 A interference prevention plate 
               342  interference prevention wall 
               344  interference prevention wall 
               344 A interference prevention plate 
               346  cut portion 
               348  interference prevention wall 
               348 A interference prevention plate 
               350  opening portion 
               352  interference prevention wall 
               352 B interference prevention body 
               354  extension part 
               356  step portion