Patent Publication Number: US-2018035869-A1

Title: Insertion device and endoscope including insertion device

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This is a Continuation Application of PCT Application No. PCT/JP2016/067412, filed Jun. 10, 2016, which was published under PCT Article 21 (2) in Japanese. This application is based upon and claims the benefit of priority from prior Japanese Patent Application No. 2015-131666, filed Jun. 30, 2015 the entire contents of which are incorporated herein by reference. 
    
    
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to an insertion device in which a raising base that changes a moving direction of a treatment tool is disposed on a distal side, and relates to an endoscope including the insertion device. 
     2. Description of the Related Art 
     In general, a treatment tool have various functions. The treatment tool, for example a forceps, is inserted into a channel of an insertion section of an endoscope main body, and extends out from an opening that is opened at a distal side. Also, there is known a swing mechanism that changes, into a desired direction, a moving direction of a treatment tool that extends out from an opening provided in a part of a distal end of an insertion section on its peripheral surface side. 
     As a typical swing mechanism, a swing base for a treatment tool (or a raising base for a treatment tool) is known. The swing base is coupled to an operation lever provided on an operation section side via a traction wire and is raised by operating the operation lever, to thereby change the moving direction of the treatment tool, such as a forceps, into a desired direction. 
     Usually, when an insertion section is inserted into a body cavity, contaminated fluid, resected living tissue, and the like (hereinafter referred to as contaminated fluid and the like), intrude from an opening portion of a storage chamber in which the swing base is disposed, and adhere to a swing base main body and its peripheral portion. After finishing treatment, it is essential to wash and disinfect an endoscope to prevent infection. Since the swing base stored in the storage chamber and a drive unit of the traction wire have a complicated structure, cleaning work to completely remove unwanted substances requires time and effort. In particular, since the traction wire is made by weaving thin steel wires, it is necessary to make sure that dirt does not remain between the wires. 
     To address the foregoing, Patent Literature 1, Jpn. Pat. Appln. KOKAI Publication No. 08-056900, for example, has suggested an endoscope in which: a storage chamber of a raising base and a drive chamber of a traction wire are separated from each other by a wall so as to prevent the traction wire from being entangled with the swing base; and a driving force transmission member that transmits the traction force of the traction wire to the raising base through the wall is disposed. 
     The patent literature is intended to prevent entanglement of wires. In separating the storage chamber of the raising base and the drive chamber of the traction wire by the wall, an O-ring is fitted to a raising base drive lever to prevent contaminated fluid and the like in the storage chamber of the raising base from entering the drive chamber, thereby achieving watertightness between the storage chamber of the raising base and the drive chamber. This makes it hard for contaminated fluid and the like to adhere to the traction wire. 
     BRIEF SUMMARY OF THE INVENTION 
     According to an embodiment of the present invention, there is provided an insertion device comprising: an operating portion that is operable and provided to an insertion section inserted into a lumen; a long traction member that is connected to the operating portion and moves in a longitudinal axis direction of the insertion section, to operate the operating portion; a distal end constituting section that is provided on a distal side of the insertion section and comprises: a treatment tool channel hole that communicates with a treatment tool insertion tube disposed in the insertion section; and an introducing hole that is provided away from an opening of the treatment tool channel hole toward a proximal side of the insertion section and guides the traction member; and a tubular elastic member in which the traction member is disposed, one end being connected to the operating portion in a watertight manner so as to prevent the traction member connected to the operating portion from being exposed to an external part, the other end being connected to the introducing hole in a watertight manner. 
     Advantages of the invention will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. 
     The advantages of the invention may be realized and obtained by means of the instrumentalities and combinations particularly pointed out hereinafter. 
    
    
     
       BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS 
       The accompanying drawings, which are incorporated in and constitute apart of the specification, illustrate embodiments of the invention, and together with the general description given above and the detailed description of the embodiments given below, serve to explain the principles of the invention. 
         FIG. 1  is a cross-sectional view showing a cross-section structure of a distal end constituting section of an insertion device according to a first embodiment, seen from the top. 
         FIG. 2  is a view showing an external configuration of the distal end constituting section of the insertion device without a distal end cover. 
         FIG. 3  is a cross-sectional view showing a cross-section structure of the distal end constituting section of the insertion device in which a swing base is laid down. 
         FIG. 4  is a cross-sectional view showing a cross-section structure of the distal end constituting section of the insertion device in which the swing base is raised. 
         FIG. 5  is a view showing a configuration example in which an endoscope is equipped with the insertion device. 
         FIG. 6  is a cross-sectional view showing a cross-section structure of a distal portion of the insertion device in which the swing base of the distal end constituting section of the insertion device is laid down. 
         FIG. 7  is a cross-sectional view showing a cross-section structure of the distal end constituting section of the insertion device in which the swing base is raised. 
         FIG. 8  is a cross-sectional view showing a cross-section structure of an elastic member. 
         FIG. 9  is a cross-sectional view showing a cross-section structure of a tube for a wire as a first modification. 
         FIG. 10  is a cross-sectional view showing a cross-section structure of a tube for a wire as a second modification. 
         FIG. 11A  is a view showing a configuration example of an engaging unit and a swing base as a first modification of an operating portion. 
         FIG. 11B  is a view showing a configuration example of an engaging unit and a swing base as a second modification of the operating portion. 
         FIG. 11C  is a view showing a configuration example of an engaging unit and a swing base as a third modification of the operating portion. 
         FIG. 11D  is a view showing a configuration example of an engaging unit and a swing base as a fourth modification of the operating portion. 
         FIG. 12  is a view showing a configuration example of the operating portion as a first modification of a wire traction mechanism. 
         FIG. 13  is a view illustrating a first procedure of installing the engaging unit. 
         FIG. 14  is a view illustrating a second procedure of installing the engaging unit. 
         FIG. 15  is a view describing a configuration example according to a second modification of the wire traction mechanism. 
         FIG. 16  is a view describing a configuration example according to a third modification of the wire traction mechanism. 
         FIG. 17  is a view describing a configuration example according to a fourth modification of the wire traction mechanism. 
         FIG. 18  is a view describing a configuration example according to a fifth modification of the wire traction mechanism. 
         FIG. 19A  is an external view of a retaining plate, seen from the top, which is a guide portion for fixing the tube for a wire and a coupling unit. 
         FIG. 19B  is an external view of the retaining plate seen from the front. 
         FIG. 20  is a view illustrating a procedure of assembling the wire traction mechanism. 
         FIG. 21  is a cross-sectional view showing a cross-section structure of the swing base of the distal end constituting section according to a third embodiment. 
         FIG. 22  is a view of a configuration, seen from the lateral side, in which a cover is provided to the distal end constituting section of the insertion device. 
         FIG. 23  is a view of a configuration, seen from the distal side, in which the cover is provided to the distal end constituting section of the insertion device. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Embodiments of the present invention will be described in detail with reference to the drawings. 
     First Embodiment 
       FIG. 1  is a cross-sectional view showing a cross-section structure of a distal end constituting section of an insertion device according to a first embodiment, seen from the top.  FIG. 2  is a view showing an external configuration of the distal end constituting section of the insertion device without a distal end cover.  FIG. 3  is a cross-sectional view showing a cross-section structure of the distal end constituting section of the insertion device in which a swing base is laid down.  FIG. 4  is a cross-sectional view showing a cross-section structure of the distal end constituting section of the insertion device in which the swing base is raised.  FIG. 5  is a view showing a configuration example in which an endoscope is equipped with the insertion device. 
     In the descriptions provided below, a swing mechanism that changes a moving direction (insertion direction) of the insertion device to a vertical direction (X-axis direction) when it is a horizontal axis direction (Y-axis), is employed as a swing base for a treatment tool (hereinafter referred to as a swing base). This swing base maybe referred to as a raising base. This swing base may be configured as a swing mechanism that is capable of changing the direction not only to the vertical direction but also to a left and right direction crossing the vertical direction. In each of the embodiments described below, only a swing mechanism that changes the direction to the vertical direction is shown to make the description simple. A mechanism that changes the direction to a left and right direction can be implemented by, for example, separating a portion supporting an axis of the swing base so that it turns in the vertical direction from a base member  3  described below, supporting the portion in a manner to turn around a horizontal axis, coupling the swing base with a traction wire having technical features described below, and arranging two vertical and horizontal traction wires in parallel in an insertion device. Needless to say, the aforementioned mechanism that changes the direction to a left and right direction is an example, and the mechanism is not limited to this structure. The mechanism may have a publicly-known structure. 
     First, a configuration example in which an endoscope is equipped with an insertion device  1  will be described. 
     The endoscope  100  is constituted by an insertion section  101  that is inserted into a lumen and an operation section  102 . An insertion port (forceps port)  110  of a treatment tool is provided on a proximal side of the insertion section  101 . A distal end constituting section  2  having a cylindrical shape is disposed on a distal side of the insertion section  101 , and a swing base operation section  107  is provided to the operation section  102 . This endoscope includes a general system structure (not shown) including, for example, a light source device that supplies illumination light, a control section including a video processor that performs image processing on an imaged video signal, a display section that displays an observation image, and a recording section that records the video signal. 
     In the insertion section  101  includes following the distal end constituting section  2  to a bending portion  103  and a flexible tube  104 , disposed toward the proximal side thereof. The insertion section  101  includes a channel conduit  111  for inserting a treatment tool, an air/water supplying tube  106  for supplying the air or a washing liquid, and a long traction wire  9  for causing a swing base  4  to swing. The insertion section  101  is connected to the swing base operation section  107  via the traction wire  9 . By a lever operation of the swing base operation section  107 , the swing base  4  swings to be raised or laid down. Among these elements, the swing base  4 , an engaging section  21 , the traction wire  9  and the swing base operation section  107  form a wire traction mechanism. Also, the swing base  4  and the engaging section  21  form an operating portion that is operable. The operation portion includes the swing base  4  that swings around a predetermined raising shaft  8  provided to the distal end constituting section  2  by the traction force of the traction wire  9 , and that changes a direction of a treatment tool (not shown) protruding from a channel opening  3   a  of a treatment tool channel hole  105 . 
     The channel conduit  111  passes through the insertion section  101  from the insertion port  110  on the proximal side and is connected to the treatment tool channel hole  105 , and the channel opening  3   a  opens at the distal end. A treatment tool is inserted from the insertion port  110 , passes through the channel conduit  111 , and extends out from the channel opening  3   a  of the treatment tool channel hole  105 . 
     The distal end constituting section  2  is generally constituted by a base member  3  formed of a hard material such as a metallic material, the swing base  4  turnably provided to the base member  3 , and a distal end cover  10  having a cylindrical shape. The base member  3  and a first bending piece  300  on the most distal side of the bending portion  103  are fixed to each other by an adhesive, a screw, or the like. The bending portion  103  is covered with a covering material  301 . A distal end of the covering material  301  is wrapped with a fixing thin wire  108 , and a surface layer side thereof is applied with an adhesive  109 . 
     The base member  3  is divided into two sides in a longitudinal axis direction m: on one side, the channel opening  3   a  and the swing base  4  before the channel opening  3   a  are disposed; and on the other side, a flat observation surface  3   b  is formed with respect to the outer peripheral surface. The channel opening  3   a  communicates with the channel conduit of the insertion section  101  through the treatment tool channel hole  105 . Also, an illumination window portion  5  to be irradiated with illumination light and an observation window portion  6  including an unshown imaging element therein are arranged on the observation surface  3   b.  A nozzle portion  7  is disposed in the vicinity of the observation window portion  6  and on the proximal side in the longitudinal axis direction m, and ejects a washing liquid such as saline, or a gas such as the air, supplied from the air/water supplying tube  106 , to suitably wash the illumination window portion  5  and the observation window portion  6 . 
     The distal end cover  10  is formed separately from the base member  3 . The distal end cover  10  forms a shape of a cup that is injection-molded by a resin material or the like, and has an opening window, a part of which facing the observation surface  3   b  and the swing base  4  is opened. When fitted into the distal end constituting section  2 , the distal end cover  10  has a cover hole  10   a  formed at a position opposite to a cover fastening hole  3   d  formed on the base member  3 . By inserting a fixing portion  13  into the cover fastening hole  3   d  overlapped with the cover hole  10   a,  the distal end cover  10  is fixed to the distal end constituting section  2 . The fixing portion  13  may have a screw clamp structure by forming a screw groove the cover fastening hole  3   d.    
     The swing base  4  has a concave shape, has an abutting surface  4   a  that abuts on a treatment tool extending out from the channel opening  3   a  to change its moving direction. An inner surface of the swing base  4  facing the base member  3  engages with the raising shaft  8  (supporting portion) provided to the base member  3 , to be turnably supported; and a guide pin  11  is provided in a substantially central area of the swing base  4 . Also, the engaging section  21  is provided on the outer surface of the swing base  4 , and the traction wire  9  as a traction member is connected thereto. The guide pin  11  moves above a guide surface  3   c  on a distal side of the base member  3 ; and at a point where the guide pin  11  abuts on the guide surface  3   c,  the raising stops, as shown in  FIG. 4 . 
     The swing base  4 , the engaging section  21 , and the traction wire  9  of the wire traction mechanism will be described. 
     A distal end of the traction wire  9  is inserted into the cylindrical engaging section  21  to be fixed. The traction wire  9  is covered with a tube  14  for the wire that is made of an elastic member having a tubular shape with a diameter that secures a certain clearance without sticking to the traction wire  9 . One end of the tube  14  for the wire is inserted into a small-diameter part of the engaging section  21  and adhered thereto so as to be watertight; and the other end is connected to one end of a coupling unit  31 . The other end of the coupling unit  31  is coupled with a guide tube  41  (introducing hole) for the wire that covers the traction wire  9  inserted through the insertion section  101  and a wire guide member  42  that covers it. In this embodiment, the tube  14  for the wire ranging from the engaging section  21  to the coupling unit  31  is installed in its natural length without expansion or contraction when the swing base  4  is laid down, as shown in  FIG. 3 . However, it does not always have to be installed in its natural length, but may be installed in an expanded manner when the swing base  4  is laid down, within the range that does not inhibit the raising operation by its elastic force. 
     The coupling unit  31  comprises: a coupling member  32  including an insertion portion  32   a  inserted into the tube  14  for the wire and a U-groove  32   b;  an engaging member  33  having a tubular shape that is externally arranged on the inserted part of the tube  14  for the wire, to press and fix it; an O-ring  34  that is fitted to the U-groove  32   b;  and a cover member  35  including a pressing portion  35   a,  which presses the O-ring  34  from the outer peripheral side, and an insertion portion  35   b  inserted into the guide tube  41  for the wire. 
     The cover member  35  presses the O-ring  34  from the outer peripheral side, and separates an inner part of the tube  14  for the wire from an outer part  1000  of the insertion section so as to be watertight. Moreover, the insertion portion  35   b  is fixed by an adhesive or the like in a state where it is inserted into the guide tube  41  for the wire. In the case of simplifying the structure of the coupling unit  31 , it is possible to adhere each of the coupling member  32  and the engaging member  33  to the cover member  35  without using the O-ring  34 , to achieve watertightness. 
     The tube  14  for the wire and the coupling unit  31  are inserted into a cutout portion  22   a  of a retaining plate  22 , and adhered thereto so that the outer peripheral surfaces of the tube  14  for the wire and the coupling unit  31  and the cutout portion  22   a  will be watertight. This adhesion is provided by filling a silicone-based adhesive  23 , for example, in a gap among the tube  14  for the wire, the coupling unit  31  and the cutout portion  22   a.  The tube  14  for the wire is not particularly limited as long as it is made of a material that is at least safe for a human body, easy to compress (or expand) in its longitudinal direction, and strong against repeated compression, but a urethane tube or a fluorine rubber, for example, is preferred. More preferably, the tube  14  for the wire is a urethane tube having a fluorine-based resin coating on the outer surface thereof. 
     The cutout portion  22   a  of the retaining plate  22  that guides the traction wire  9  is provided at a position that is away from the channel opening  3   a  toward the proximal side by the distance A in the longitudinal axis direction, as shown in  FIGS. 1 and 3 . In this embodiment, since the adhesive  23  is formed in a manner protruding from the cutout portion  22   a,  the distance A is specifically a distance from the channel opening  3   a  to a distal portion (a position where the tube for the wire is fixed) of the adhesive  23  of the cutout portion  22   a.  Namely, this distance A is used as a space for accommodating a wrinkle  14   a  of the tube  14  for the wire that is shrunk when the swing base  4  is raised, as shown in  FIG. 4 . 
     That is, when the tube  14  for the wire is shrunk to the distance I, the wrinkle  14   a  of the tube  14  can be formed not only on the distal side of the channel opening  3   a,  but also between the channel opening  3   a  and the cutout portion  22   a  of the retaining plate  22 . Accordingly, if the swing base  4  is in a raised state, it is possible to reduce the amount of deformation of the whole tube  14  for the wire caused at the time of shrinkage, relative to the entire length, and reduce the height (amplitude) of the wrinkle  14   a  or the number of wrinkles if the height is the same. Since the adhesive  23  is not always formed in a manner protruding from the cutout portion  22   a  as described in this embodiment, the distance A is set to a distance from the position of the channel opening  3   a  to the position where the tube for the wire is fixed. Therefore, the position where the tube for the wire is fixed (an end position on the proximal side where the tube  14  for the wire can be deformed) may not only be the distal position of the adhesive, but also the position of the cutout portion  22   a  of the retaining plate  22  or a position where the tube is fixed by another component. 
     This distance A, that is, the space for accommodating the wrinkle  14   a  of the tube  14  for the wire is set according to the traction amount (distance) of the traction wire  9  and the elastic deformation of the tube  14  for the wire. This is set at least in a way that prevents the wrinkles  14   a  generated in the tube  14  for the wire from sticking to each other when the swing base  4  is pulled by the traction wire  9  to be raised and the tube  14  for the wire is shrunk to the distance I, as shown in  FIG. 4 . 
     By including not only the distal side of the channel opening  3   a,  but also the distance A between the channel opening  3   a  and the cutout portion  22   a  of the retaining plate  22  or the adhesive  23  for the tube  14  for the wire in this manner when the swing base  4  is laid down, it is possible to reduce the size and the number of wrinkles  14   a  when the tube  14  is shrunk to the distance I. Namely, the longer the distance I is set, the smaller the height (amplitude) of the wrinkle  14   a  will be, allowing reduction of the size and the number of wrinkles  14   a.  In this embodiment, the distance A is obtained by moving the retaining plate  22 , which fixes the tube  14  for the wire, closer to the proximal side than the channel opening  3   a  relative to the swing base  4  when arranging each component at the time of design. This movement merely increases the distance in the longitudinal axis direction for the base member  3 , and is realized without increasing the outer diameter of the distal end constituting section  2 . Also, since the distal end constituting section  2  is used in a state where the distal end cover  10  is fitted thereto, no problem occurs in raising and laying down the swing base even if the distance A part in which the tube  14  for the wire moves increases. 
     The distal end constituting section  2  of the insertion device of this embodiment described above includes an end portion of the traction wire  9 , and the entire traction wire  9  is covered with the tube  14  for the wire made of a tubular elastic member in a watertight manner, so that the traction wire  9  is not exposed to the outside. Therefore, even if a contaminated fluid and the like remain in the periphery of the swing base  4  or in the vicinity of the channel opening during treatment, it will not touch the traction wire  9 . 
     In addition, the height (amplitude) of the wrinkle  14   a  generated in the tube  14  for the wire at the time of raising the swing base is reduced, and even if a treatment tool is moved forward and backward in the vicinity, the treatment tool does not interfere with the wrinkle  14   a.  Also, since the distance I at the time of raising the swing base  4  has a certain length relative to the natural length, a load imposed by expansion and contraction of the elastic member is reduced, and even if the action of raising and laying down is repeated, the tube does not degrade, leading to improvement of the durability. 
     Since both the size and the number of wrinkles  14   a  caused at the time of raising can be reduced, even if washing and disinfection are performed while the swing base  4  is raised, a sufficient washing effect can be achieved because there are no overlapping portions of the wrinkle  14 . Also, since the tube  14  for the wire and the guide tube  41  for the wire are coupled with each other by the coupling unit  31  with a watertight structure, even if the tube  14  for the wire is incidentally damaged, and polluted water intrudes into the cover from the outside, the polluted water does not directly enter an insertion section internal part  2000 . An end portion of the guide tube  41  for the wire of this embodiment is opened in the operation section  102 , as shown in  FIG. 5 . 
     Second Embodiment 
     A second embodiment will be described with reference to  FIGS. 6 to 8 . 
       FIG. 6  is a cross-sectional view showing a cross-section structure of a distal portion of the insertion device in which the swing base of the distal end constituting section of the insertion device is laid down.  FIG. 7  is a cross-sectional view showing a cross-section structure of the distal end constituting section of the insertion device in which the swing base is raised.  FIG. 8  is a cross-sectional view showing a cross-section structure of the tube for the wire. In the description of this embodiment, the structural parts equivalent to those of the first embodiment are identified by the same reference symbols as those used for the first embodiment, and detailed explanations thereof are omitted. 
     The distal end constituting section  2  of the insertion device of this embodiment is different from that of the first embodiment in the cross-sectional shape of the tube for the wire, and is the same as that of the first embodiment in the other structural parts. A tube  15  for the wire shown in  FIG. 8  is formed of the same elastic material as that of the tube  14  for the wire of the first embodiment, and has parts that are different from each other in thickness. Usually, if an elastic member having two different thicknesses is shrunk in a longitudinal axis direction, a thinner part of the elastic member will have a wrinkle first. The tube  15  for the wire of this embodiment is configured so that areas  15   b,  which respectively range from the vicinity of the parts coupled with the engaging section  21  and the coupling unit  31  on both sides of the cover to the end parts, have a thickness t 2  that is greater than a thickness t 1  of an area  15   a  in the middle where it is desired to form a wrinkle (t 1 &lt;t 2 ). 
     The tube  15  for the wire is installed in its natural length in a state where the swing base  4  is laid down, as shown in  FIG. 6 . If the swing base  4  is raised from this state by pulling the traction wire  9 , a wrinkle is actively generated in the thinner area A ( 15   a ) having the thickness t 1 , as shown in  FIG. 7 . 
     In this manner, when the tube  15  for the wire shrinks, it can have the area A in which a wrinkle is actively generated and an area B in which it is desired to inhibit generation of a wrinkle. In this embodiment, when the swing base  4  is raised, generation of a wrinkle is inhibited in the area B in which a treatment tool that moves forward and backward intersects with the traction wire  9 , and a wrinkle is actively generated in the area A that does not cross other structural parts including the treatment tool, as shown in  FIG. 7 . 
     As described above, according to this embodiment, the position of the wrinkle generated at the time of raising the swing base  4  can be set as one chooses, by adjusting the thickness of the tube  15  for the wire. Thereby, the tube  15  for the wire can avoid generation of a wrinkle in the area close to a treatment tool that is moved forward and backward. 
     [First Modification of Tube for Wire] 
     A first modification of the tube for the wire will be described. 
       FIG. 9  is a cross-sectional view showing a cross-section structure of a tube for a wire as a first modification. In the description of this modification, the structural parts equivalent to those of the first embodiment are identified by the same reference symbols as those used for the first embodiment, and detailed explanations thereof are omitted. 
     The tube  16  for the wire of this modification is formed of the same material as that of the tube  15  for the wire described above, and includes a tapered area  16   a  in which an outer diameter is constant and an inner diameter changes to be tapered, and a constant thickness area  16   b  in which the thickness is constant. The tapered area  16   a  starts from the coupling unit  31  on the proximal side to the engaging section  21  of the swing base  4  not shown, and is tapered so that an inner diameter is linearly decreased. 
     According to this modification, the tube  16  for the wire is configured so that a wrinkle with the largest amplitude is generated at the thinnest part of the tapered area  16   a  when the swing base  4  is raised, and that the amplitude of the wrinkle gradually decreases as the thickness increases. Accordingly, it is possible to prevent a wrinkle generated at the time of raising the swing base  4  from interfering with an inserted treatment tool by decreasing the size of the wrinkle on the swing base  4  side and increasing the size of the wrinkle on the coupling unit  31  side. 
     [Second Modification of Tube for Wire] 
     A second modification of the tube for the wire will be described. 
       FIG. 10  is a cross-sectional view showing a cross-section structure of a tube for a wire as a second modification. In the description of this modification, the structural parts equivalent to those of the first embodiment are identified by the same reference symbols as those used for the first embodiment, and detailed explanations thereof are omitted. 
     A tube  17  for a wire of this modification is formed of the same material as that of the tube  14  for the wire described above, and is configured to have an area in which a wrinkle is generated by partially changing the hardness. By the publicly known technique, the middle area  17   a  of the tube  17  for the wire shown in  FIG. 10  is formed as a soft part, and the side areas  17   b  on both sides of the middle area  17   a  shown in  FIG. 10  are formed to be harder than the middle area  17   a.  The difference in hardness can be realized by, for example, integrally forming the tube using the same main ingredient and selecting different degrees of hardness. 
     According to this modification, when the swing base  4  is raised, the tube  17  for the wire can have a large wrinkle actively generated in the soft middle area  17   a,  and can be prevented from having a wrinkle in the vicinity of the coupling unit  31  and the engaging section  21 . Accordingly, it is possible to inhibit generation of a wrinkle on the swing base  4  side and prevent a wrinkle generated at the time of raising the swing base  4  from interfering with an inserted treatment tool. 
     [First Modification of Operating Portion] 
     A configuration example of the engaging unit and the swing base as a first modification of the operating portion will be described with reference to  FIG. 11A . 
     An engaging unit  51 , which has a cylindrical shape, comprises a small-diameter part  51   a  and a large-diameter part  51   b  with a step (large-diameter part)  51   c.  The small-diameter part  51   a  is extended out from an engaging hole  4   b  of the swing base  4 , and is bent at a substantially right angle. The engaging unit  51  is fitted into the engaging hole  4   b  with a clearance. Since the inner diameter of the engaging hole  4   b  of the swing base  4  is smaller than the outer diameter of the large-diameter part  51   c,  the engaging unit  51  is supported turnably without dropping out of the engaging hole  4   b.    
     The engaging unit  51  shown in  FIG. 11A  has a fixing hole  51   d  formed at a depth from the distal surface of the small-diameter part  51   a  to the front of the bent part. A distal end of the traction wire  9  is inserted into this fixing hole  51   d,  as described below, and is fixed thereto by brazing or soldering, etc., which provides strong fixation. 
     [Second Modification of Operating Portion] 
     A configuration example of the engaging unit and the swing base as a second modification of the operating portion will be described with reference to  FIG. 11B . 
     An engaging unit  52 , like the above-described engaging unit  51 , has a cylindrical shape and comprises a small-diameter part  52   a  and a large-diameter part  52   b  with a step  52   c.  The engaging unit  52  is provided so that the small-diameter part  52   a  is extended out from the engaging hole  4   b  of the swing base  4  and bent at an approximate right angle. A fixing hole  52   d  is formed at a depth from the distal surface of the small-diameter part  52   a  to the middle of the large-diameter part  52   b.    
     In this modification, a window  4   d,  where the lateral side of the engaging hole  4   b  of the swing base  4  is partially opened, is formed, and the side surface of the fitted large-diameter part  52   b  is partially exposed. 
     Since the large-diameter part is partially exposed to the outside in this modification, in addition to the clearance provided between the engaging hole  4   b  and the large-diameter part  52   b,  it is possible to efficiently pour a chemical to wash the swing base  4 . 
     [Third Modification of Operating Portion] 
     A configuration example of the engaging unit and the swing base as the third modification of the operating portion will be described with reference to  FIG. 11C . 
     An engaging unit  53 , like the above-described engaging unit  51 , has a cylindrical shape and comprises a small-diameter part  53   a  and a large-diameter part  53   b  with a step  53   c.  The engaging unit  53  is provided so that the small-diameter part  53   a  is extended out from the engaging hole  4   b  of the swing base  4  and bent at a substantially right angle. A fixing hole  53   d  is formed at a depth from the distal surface of the small-diameter part  53   a  to the middle of the large-diameter part  53   b.    
     In this modification, an adhesive  54  is filled in a clearance between the engaging hole  4   b  and the engaging unit  53  to fix the engaging unit  53  to the engaging hole  4   b.  Namely, the clearance to be washed is removed so that there is no gap for a contaminated fluid to enter. Even if the engaging unit  53  and the swing base  4  are in a fixed state, there will be no practical problem on the action of raising and lying down as long as the angle at which the swing base is raised from the state of being laid down (0°) is not greater than 90°. 
     [Fourth Modification of Operating Portion] 
     A configuration example of the swing base having a function of engaging with the traction wire, which is a fourth modification of the operating portion, will be described with reference to  FIG. 11D . 
     In this modification, the swing base  4  is not engaged with a separate engaging unit, but includes an L-shaped engaging unit  4   e  provided integrally as a part of the swing base  4 . A linear fixing hole  4   f  is formed at a depth similar to that shown in 
       FIG. 11A  from an end surface of the engaging unit  4   e,  and the traction wire  9  is inserted into the hole to be fixed. 
     [First Modification of Wire Traction Mechanism] 
     A configuration example of the operating portion by the traction wire  9  and the engaging section  21  will be described as a first modification of the wire traction mechanism, with reference to  FIG. 12 . 
     The engaging section  21  comprises a small-diameter part  21   a  and a large-diameter part  21   b  with a step  21   c.  A fixing hole  21   d  is formed from the distal surface of the small-diameter part  21   a  to the middle of the large-diameter part  21   b,  and the distal end of the traction wire  9  is inserted into the fixing hole  21   d  to be fixed by an adhesive or soldering. Since the distal end of the traction wire  9  is inserted into the fixing hole  21   d  in this manner, the end portion of the wire is not exposed to the outside, either. In the case of fixing the traction wire  9  to the fixing hole  21   d,  the small-diameter part  21   a  of the engaging section  21  may be swaged to be fixed without using an adhesive. 
     A first procedure of attaching the engaging section  21  to the swing base  4  will be described with reference to  FIG. 13 . First, the traction wire  9  is inserted into the fixing hole  21   d  of the small-diameter part  21   a  from the distal end of the traction wire  9 , to be fixed by an adhesive (S 1 ). After the unit is inserted into the swing base  4  in the direction of S 1 , the small-diameter part  21   a  is bent at a substantially right angle together with the traction wire  9  (S 2 ). 
     Next, the distal end of the tube  14  for the wire, the proximal end of which is attached with the coupling unit  31 , is inserted from the back end of the traction wire  9  in a manner to cover the traction wire  9  (S 3 ). The distal end of the tube  14  for the wire is inserted until it covers the small-diameter part  21   a  of the engaging section  21 , so that the tube  14  for the wire is fixed to the small-diameter part  21   a  by an adhesive. 
     Thereby, the traction wire  9  is entirely covered with the engaging section  21  and the tube  14  for the wire, and has no part that is exposed. Also, since the small-diameter part  21   a  is bent at an approximate right angle together with the traction wire  9 , the traction wire  9  can be coupled with the swing base  4  in a manner that the swing base can turn freely. By the clearance between the engaging section  21  and the engaging hole  4   b  of the swing base  4  created by the turning, a washing liquid or a disinfectant, etc., circulates well at the time of reprocessing after finishing an examination. 
     A second procedure of attaching the engaging section  21  to the swing base  4  will be described with reference to  FIG. 14 . First, the engaging section  21  is inserted into the engaging hole  4   b  of the swing base  4 , and the small-diameter part  21   a  is extended out from the engaging hole  4   b  (S 1 ). The small-diameter part  21   a  is bent backward at an approximate right angle (S 2 ). The traction wire  9  is inserted into the fixing hole  21   d  of the bent small-diameter part  21   a  from the distal end of the traction wire  9 , and is fixed by an adhesive (S 3 ). 
     Next, the distal end of the tube  14  for the wire, the proximal end of which is attached with the coupling unit  31 , is inserted from the back end of the traction wire  9  in a manner to cover the traction wire  9 . The distal end of the tube  14  for the wire is inserted until it covers the small-diameter part  21   a  of the engaging section  21 , to be fixed by an adhesive (S 4 ). Thereby, the traction wire  9  is entirely covered with the engaging section  21  and the tube  14  for the wire, and has no part that is exposed. In this example as well, by the clearance between the engaging section  21  and the engaging hole  4   b  of the swing base  4  created by the turning, a washing liquid or a disinfectant, etc., circulates well at the time of reprocessing after finishing an examination. 
     [Second Modification of Wire Traction Mechanism] 
     A configuration example by the traction wire  9  and the engaging unit  51  will be described as a second modification of the wire traction mechanism, with reference to  FIG. 15 . The components can be assembled by following the above-described second procedure shown in  FIG. 14 . 
     First, the engaging unit  51  is inserted into the engaging hole  4   b  of the swing base  4 , and the small-diameter part  51   a  extended out is bent backward at an approximate right angle. The traction wire  9  is inserted into the fixing hole  51   d  of the bent small-diameter part  51   a  from the distal end of the traction wire  9 , and is fixed by a strong fixing method such as brazing. Then, the distal end of the tube  14  for the wire, the proximal end of which is attached with the coupling unit  31 , is inserted from the back end of the traction wire  9 , to cover the small-diameter part  51   a.  At this time, the tube  14  for the wire and the small-diameter part  51   a  are fixed to each other by an adhesive. 
     With this configuration, the traction wire  9  connected to the operating portion can be prevented from being exposed to the distal end cover  10  by the tube  14  for the wire, and even if polluted water and the like enter the distal end cover  10  during treatment, the polluted water and the like will not adhere to the traction wire  9 . 
     [Third Modification of Wire Traction Mechanism] 
     A configuration example by the traction wire  9  and the engaging unit  55  will be described as a third modification of the wire traction mechanism, with reference to  FIG. 16 . 
     The engaging unit  55  of this modification comprises a small-diameter part  55   a  and a large-diameter part  55   b  with a step  55   c.  A fixing hole  55   d  is formed in a manner penetrating through the large-diameter part  55   b  from the distal surface of the small-diameter part  55   a.  The distal end of the traction wire  9  is inserted into the fixing hole  55   d  and stopped at a position before piercing through the large-diameter part  55   b.  The traction wire  9  is fixed by an adhesive at this position, and an epoxy-based adhesive or lead-free stainless solder, for example, is filled in the hole from the bottom side of the large-diameter part  55   b  to fill up the hole, and is solidified. 
     In this manner, the distal end of the traction wire  9  is fixed in the engaging unit  55 , and the traction wire  9  is not exposed to the outside by filling up the hole. Even if the hole is a through-hole, watertightness can be achieved by fastening and fixing the distal end of the traction wire  9  in the engaging unit  55 , and blocking up the through-hole completely by an adhesive, solder, or the like. Even if the traction wire  9  should pierce through the engaging unit  55 , letting the distal portion thereof be exposed to the outside, watertightness can still be maintained by covering it with solder or an adhesive having a waterproof function, for example, so as to prevent a contaminated fluid and the like from permeating the exposed part. 
     [Fourth Modification of Wire Traction Mechanism] 
     A configuration example of a joint structure between the tube  14  for the wire and the traction wire  9  hung on the engaging section  21  will be described as a fourth modification of the wire traction mechanism, with reference to  FIG. 17 . 
     The fourth modification of the wire traction mechanism is a wire traction mechanism using the above-described engaging section  21  shown in  FIG. 12 . 
     The traction wire  9  is fixed to the engaging section  21  fitted into the engaging hole  4   b  of the swing base  4 . Both the traction wire  9  and the small-diameter part  21   a  are bent backward at a substantially right angle. The tube  14  for the wire which is attached the proximal end of with the coupling unit  31 , is inserted in a manner to cover the traction wire  9 . The insertion is stopped at a position where the distal end of the tube  14  for the wire is close to the small-diameter part  21   a  of the engaging section  21 . Next, in the state where the traction wire  9  is covered, an adhesive is filled in so as to fill up the clearance between the tube  14  for the wire and the traction wire  9 , and the adhesive  21   e  is shaped in a manner to cover at least the end portion of the small-diameter part  21   a  and the end portion of the tube  14  for the wire and prevent the traction wire  9  from being exposed. 
     In this manner, even if the tube  14  for the wire is not adhered to the engaging section  21  directly, a watertight structure can be achieved in which the tube  14  for the wire and the engaging section  21  are connected to each other via an adhesive in a watertight manner and the traction wire  9  is not exposed. 
     [Fifth Modification of Wire Traction Mechanism] 
     A configuration example of a joint structure between the tube  14  for the wire and the traction wire  9  hung on the engaging section  21  will be described as a fifth modification of the wire traction mechanism, with reference to  FIG. 18 . 
     The fifth modification of the wire traction mechanism, like the above-described fourth modification, is a wire traction mechanism using the engaging section  21  shown in  FIG. 12 . The traction wire  9  is fixed to the engaging section  21  fitted into the engaging hole  4   b  of the swing base  4  by an adhesive and solder  59 . 
     Next, the tube  14  for the wire covers the traction wire  9 , and the insertion is stopped at a position where the covering end portion comes close to the small-diameter part  21   a  of the engaging section  21  and comes in contact with the solder. Then, an adhesive is filled in so as to cover the tube  14  for the wire and the solder  59  and to fill up the clearance between the tube  14  for the wire and the traction wire  9 , and the adhesive  21   e  is shaped in a manner to cover at least the end portion of the small-diameter part  21   a  and the end portion of the tube  14  for the wire and prevent the traction wire  9  from being exposed. 
     According to this modification, the traction wire  9  is kept watertight by fixing the traction wire  9  to the engaging section  21  by the adhesive and the solder  59 , and further fixing the tube  14  for the wire to the engaging section  21  while covering it with the adhesive  21   e  in a manner to include the surface of the solder  59  and make the traction wire  9  watertight. 
     Next, a procedure of assembling the wire traction mechanism will be described with reference to  FIGS. 19A, 19B and 20 . 
       FIG. 19A  is an external view of the retaining plate  22 , seen from the top, which is a guide portion for fixing the tube  14  for the wire and the coupling unit  31 .  FIG. 19B  is an external view of the retaining plate  22  seen from the front.  FIG. 20  is a view illustrating a procedure of assembling the wire traction mechanism. 
     The retaining plate  22  of this embodiment is formed of a metal material or a hard resin member, and has a fan shape with the central angle being 90° and the arc being the same as the outer periphery of the distal end constituting section  2 . The retaining plate  22  has a cutout portion formed therein that practically matches the shape of the section where the tube  14  for the wire and the coupling unit  31  are coupled with each other. 
     This retaining plate  22  fits the cutout portion  22   a  to the section where the tube  14  for the wire and the coupling unit  31  are coupled with each other, and is adhesively fixed to the base member  3  to thereby prevent the tube  14  for the wire and the coupling unit  31  from coming off. 
     In addition, sufficiently applying an adhesive to the portion contacting the tube  14  for the wire and the coupling unit  31  as well to fill it up at the time of fixing, as shown in  FIG. 1 , makes it possible to maintain watertightness so as to prevent a contaminated fluid and the like from permeating the insertion section from a gap. 
     An assembling procedure will be described with reference to  FIGS. 1 and 20 . 
     P1) The traction wire  9  extending out from the coupling unit  31  is shoved in so that it enters the guide tube  41  for the wire from the opening of the cover member  35  attached to the base member  3  and the distal end of the wire reaches the swing base operation section  107  in the operation section  102 . 
     Afterwards, the coupling member  32  attached with the O-ring  34  is inserted and fitted into the pressing portion  35   a  of the cover member  35 . At this time, the edge of the engaging member  33  is located at a predetermined position that abuts on the retaining plate  22 . At this time, a position is determined in advance so that a hole  8   a  to be fitted with the raising shaft  8  of the swing base  4  matches a hole  8   b  to be fitted with the raising shaft  8  provided to the base member  3 . A temporary joint can be made depending on the case. 
     P2) The silicone-based adhesive  23  is applied to the inner surface of the cutout portion  22   a  and the portion of the retaining plate  22  joining the base member  3 , to fit and fix the retaining plate  22  to the base member  3 . 
     P3) After matching the hole  8   a  and the hole  8   b  in a manner to overlap each other, the raising shaft  8  passing through the hole  8   a  is fixed to the hole  8   b.    
     Third Embodiment 
     A third embodiment will be described with reference to  FIG. 21 . 
       FIG. 21  is a cross-sectional view showing a cross-section structure, seen from the top, of a distal portion of the insertion device in which the swing base of the distal end constituting section of the insertion device is laid down. In the description of this embodiment, the structural parts equivalent to those of the first embodiment are identified by the same reference symbols as those used for the first embodiment, and detailed explanations thereof are omitted. 
     The end portion of the guide tube  41  for the wire is opened in the operation section  102 , as described above. In this embodiment, a second opening  35   c,  which opens in the insertion section  101  on the proximal side of the distal end constituting section, is provided near the pressing portion  35   a  of the cover member  35 . 
     In a washing step after finishing examination and treatment, whether or not there is a water leak in the endoscope is confirmed without fail. As the method to confirm this, the endoscope is sunk into water with the inside of the endoscope pressurized, to confirm that there are no bubbles coming out of the endoscope. Namely, if there are bubbles coming out of the tube  14  for the wire, the endoscope is broken for some reason. However, even if the inside of the operation section  102  is pressurized, it takes some time for the inside of the tube  14  for the wire to be pressurized because the insertion section  101  is long, and the length from the guide tube  41  for the wire to the tube  14  for the wire is large. 
     In this embodiment, the second opening  35   c  is opened at a position that is close to the tube  14  for the wire and in which a contaminated fluid and the like do not enter from the outside, i.e., in the vicinity of the pressing portion  35   a  of the cover member  35  in the insertion section  101 . By opening at this position, a gas is sent into the tube  14  for the wire immediately after starting pressurization of the inside of the endoscope. Thus, in the case where there is a hole, a crack, or the like in the tube  14  for the wire, it can be checked immediately. Accordingly, a water leak is less likely to be overlooked, a negative influence of liquid on an electronic device by mistake can also be prevented, and the problem can be solved simply by replacing the component. 
     Fourth Embodiment 
     A fourth embodiment will be described with reference to  FIGS. 22 and 23 . 
       FIG. 22  is a view of a configuration, seen from the lateral side, in which a cover is provided to the distal end constituting section of the insertion device.  FIG. 23  is a view of the configuration, seen from the distal side, in which the cover is provided to the distal end constituting section of the insertion device. In the description of this embodiment, the structural parts equivalent to those of the first embodiment are identified by the same reference symbols as those used for the first embodiment, and detailed explanations thereof are omitted. 
     As shown in  FIG. 22 , a tube cover  61  is provided that has a length ranging from the channel opening  3   a  in the base member  3  of the distal end constituting section to the retaining plate  22  and including the above-described distance A. The tube cover  61  covers the tube  14  for the wire, ranging from the side surface to the top surface in a manner to isolate the tube  14 , as show in  FIG. 23 . 
     Providing such tube cover  61  prevents the wrinkle  14   a  generated in the tube cover  61  at the time of raising the swing base  4  from contacting the external elements, as shown in  FIG. 4 , and thereby prevents a treatment target from being held or engulfed by the wrinkle. 
     As described above, the insertion device of this embodiment has the features and effects described below. 
     In the long insertion device, the entire connecting part of the end portion of the traction wire coupled with the swing base in the distal end constituting section is covered with a tubular elastic member in a watertight manner, and the elastic member is fixed at a position that is away from the opening of the treatment tool channel hole toward the proximal side by a predetermined distance in the longitudinal axis direction. This prevents the traction wire from being exposed to the outside and prevents a contaminated fluid and the like from adhering thereto during treatment. Accommodating the successive wrinkles generated in the elastic member shrunk at the time of raising the swing base in the space created at a predetermined distance prevents the wrinkles from sticking to each other. The amplitude of the wrinkle generated can be set by changing the thickness of the elastic member depending on the area where the elastic member is disposed, and the engulfment in the elastic member or the damage thereof can be avoided by decreasing the amplitude of the wrinkle in the area adjacent to the moving device such as the swing base  4 . 
     In addition, by providing an opening at a position that is close to the part of the tubular elastic member that is exposed in the distal end constituting section and where the tubular elastic member is not exposed to the outside in the inside of the insertion device, etc., and pressurizing the inside of the insertion device, the state, or position of damage can be identified easily from a gas leak from the elastic member exposed to the outside. 
     According to the present invention, it is possible to provide: an insertion device that achieves a watertight structure for a traction wire without increasing an outer diameter, makes it easy to wash a treatment swing base, and facilitates movement of a treatment tool at a time of raising the swing base; and an endoscope including the insertion device. 
     Additional advantages and modifications will readily occur to those skilled in the art. Therefore, the invention in its broader aspects is not limited to the specific details and representative embodiments shown and described herein. 
     Accordingly, various modifications may be made without departing from the spirit or scope of the general inventive concept as defined by the appended claims and their equivalents.