Endoscope

Abstract

To provide an endoscope which has a sheath into which a wire for bending is inserted, the endoscope being suitable for inexpensive production.SOLUTION: An endoscope 1 comprises: a bending tube 2b that is provided along a longitudinal axis O; a wire 11 that bends the bending tube; a first sheath 13 through which the wire is passed; and an annular plate material 14 that is arranged on a base end side of the bending tube. The plate material has: a first annular surface 14a on a tip side; a second annular surface 14b on a base end side orthogonal to the longitudinal axis; and a hole 14c that penetrates the first annular surface and the second annular surface, and through which the wire is passed. The first sheath is at least partially disposed on the base end side of the plate material, and at least a part of a tip end thereof presses a peripheral edge part of the hole on the second annular surface.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to an endoscope having a bending tube that can be bent by pulling or loosening a wire. [Background technology]

[0002] Endoscopes equipped with a bending tube (also called a bending section) have been proposed. The bending tube changes the direction of the tip by pulling or loosening a bending wire, which in turn changes the observation direction of the endoscope. The bending wire is inserted from the operation section of the endoscope to the bending tube.

[0003] In a flexible tube, a bending wire is inserted into a sheath that guides the wire, and a configuration that reduces friction generated between the sheath and the wire may be adopted.

[0004] For example, if the insertion portion can be made watertight, lubricants such as silicone oil or carbon powder may be used to reduce friction.

[0005] Furthermore, if it is not possible to ensure watertightness inside the insertion portion, an inner sheath may be provided, which has less friction with the wire than the sheath itself. In this case, the wire is inserted into the sheath while still inserted through the inner sheath.

[0006] For example, Japanese Patent Publication No. 6028136 describes the use of a coil sheath formed by winding a wire into a coil as the sheath through which a bending wire is inserted. Specifically, the bending wire is inserted into an inner coil sheath and then into an outer coil sheath. The distal end of the outer coil sheath is fixed to the inner surface of the distal end of the flexible tube, and the proximal end surface of the outer coil sheath is fixed to a fixing plate within the operating unit. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] Japanese Patent No. 6028136 Summary of the Invention [Problem to be solved by the invention]

[0008] Generally, a sheath through which a bending wire is inserted is subjected to a traction load when the bending wire is pulled to bend the bending tube, and therefore the sheath is firmly fixed to the distal end side of the flexible tube or the proximal end side of the bending tube by, for example, welding.

[0009] However, welding and the like require skilled workers to use jigs, and are therefore not suitable for manufacturing inexpensive endoscopes.

[0010] An object of the present invention is to provide an endoscope that is suitable for manufacturing inexpensive endoscopes and that includes a sheath through which a bending wire is inserted. [Means for solving the problem]

[0011] An endoscope according to one aspect of the present invention comprises a bending tube arranged along a longitudinal axis extending from a base end side to a tip end side, a wire configured to be pulled or relaxed to bend the bending tube, a first sheath through which the wire is inserted, and an annular plate material arranged on the base end side of the bending tube, wherein the plate material has a first annular surface on the tip end side, a second annular surface on the base end side perpendicular to the longitudinal axis, and a hole that penetrates the first annular surface and the second annular surface and through which the wire is inserted, and at least a portion of the first sheath is arranged on the base end side of the plate material, and the tip of at least a portion of the first sheath presses against the peripheral portion of the hole in the second annular surface.

[0012] An endoscope according to one aspect of the present invention comprises a bending tube arranged along a longitudinal axis extending from a base end side to a tip end side, a wire configured to be pulled or relaxed to bend the bending tube, a first sheath through which the wire is inserted, and an annular plate material arranged on the base end side of the bending tube, wherein the plate material has a first annular surface on the tip end side, a second annular surface on the base end side perpendicular to the longitudinal axis, and a hole that penetrates the first annular surface and the second annular surface and through which the wire is inserted, and at least a portion of the first sheath is arranged on the base end side of the plate material, and the tip of at least a portion of the first sheath generates a frictional force in a direction intersecting the longitudinal axis between the first sheath and the peripheral portion of the hole in the second annular surface.

[0013] An endoscope according to one aspect of the present invention comprises a bending tube arranged along a longitudinal axis extending from a base end side to a tip end side, a wire configured to be pulled or relaxed to bend the bending tube, a first sheath, a second sheath inserted into the first sheath and through which the wire is inserted, and an annular plate material arranged on the base end side of the bending tube, the plate material having a first annular surface on the tip end side, a second annular surface on the base end side, and a hole penetrating the first annular surface and the second annular surface and through which the wire is inserted, at least a portion of the first sheath is arranged on the base end side of the plate material, and the tip of at least a portion of the first sheath presses the peripheral portion of the hole in the second annular surface, the wire and the second sheath are inserted through the hole, and the tip of the second sheath is arranged distal to the hole. [Effects of the Invention]

[0014] According to the present invention, it is possible to provide an endoscope that is suitable for manufacturing an inexpensive endoscope and that is equipped with a sheath through which a bending wire is inserted. [Brief explanation of the drawings]

[0015] [Figure 1] FIG. 1 is a perspective view showing a configuration of an endoscope according to a first embodiment of the present invention, with some parts omitted; [Figure 2]FIG. 10 is a cross-sectional view showing a configuration of a bending wire at a connection portion between the bending tube and the flexible tube in the first embodiment; [Figure 3] FIG. 1 is a partial perspective view showing the configuration of a bending wire, an inner sheath, a sheath, and a plate member in the first embodiment; [Figure 4] In the first embodiment, a cross-sectional view of the bending tube near the plate material, taken perpendicular to the longitudinal axis; [Figure 5] FIG. 10 is a cross-sectional view of a modified example of the plate material in the first embodiment, cut along a plane parallel to the longitudinal axis; [Figure 6] FIG. 10 is a cross-sectional view showing, from an oblique direction, the configuration of a second plate member arranged on the distal end side of the bending tube in the first embodiment; [Figure 7] FIG. 10 is a cross-sectional view showing wires inserted through four holes in the second plate member in the first embodiment; [Figure 8] FIG. 10 is a cross-sectional view showing two wires inserted into two holes in a second plate member in the first embodiment; [Figure 9] FIG. 10 is a perspective view showing a fixing member disposed in the operation unit in the first embodiment; [Figure 10] FIG. 3 is a cross-sectional view showing a part of the structure of the fixing member in the first embodiment; [Figure 11] FIG. 10 is a diagram showing how the position at which the sheath is cut is set according to the actual length of the flexible tube main body in the first embodiment; [Figure 12] FIG. 10 is a side view showing an operation mechanism disposed in the operation unit in the first embodiment; [Figure 13] FIG. 13 is a partial perspective view showing the operation mechanism of the first embodiment, viewed from the direction of arrow A1 in FIG. 12; [Figure 14] FIG. 10 is a diagram for explaining a step of fixing a bending wire to an operation mechanism in the first embodiment; [Figure 15] FIG. 10 is a diagram showing that the sheath is held in a state in which it presses the plate material and the fixing member in the first embodiment; [Figure 16]FIG. 10 is a cross-sectional view showing the relationship between the sheath and the wire when an inner sheath is not provided in the first embodiment; [Figure 17] FIG. 10 is a diagram showing an example of the configuration of a sheath in a second embodiment of the present invention; [Figure 18] FIG. 10 is a diagram showing a first example of a swing angle of a wire in the third embodiment of the present invention; [Figure 19] FIG. 10 is a diagram showing a second example of the swing angle of the wire in the third embodiment; [Figure 20] FIG. 10 is a diagram showing an example of the configuration of a sheath in a fourth embodiment of the present invention; [Figure 21] 10 is a diagram showing an example of the configuration of a portion of the second annular surface of the plate member with which the tip of the sheath abuts in the fifth embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0016] Hereinafter, embodiments of the present invention will be described with reference to the drawings, but the present invention is not limited to the embodiments described below.

[0017] In the drawings, the same or corresponding elements are appropriately designated by the same reference numerals. It should be noted that the drawings are schematic, and that the length relationships, length ratios, and quantities of elements within a single drawing may differ from reality in order to simplify the explanation. Furthermore, there may be cases where the length relationships, ratios, quantities, etc. differ between multiple drawings.

[0018] [First embodiment] 1 to 16 show a first embodiment of the present invention. Fig. 1 is a perspective view showing the configuration of an endoscope 1 of the first embodiment, with some parts omitted.

[0019] The endoscope 1 is an insertion device that has a portion to be inserted into a subject. The subject may be a living body such as a human or animal, or a non-living body such as a machine or building.

[0020] The endoscope 1 includes an insertion section 2 , an operation section 3 , and a universal cable 4 .

[0021] The insertion section 2 is configured to be inserted into a subject, and includes, in order from the distal end to the proximal end, a distal end portion 2a, a bending tube 2b, and a flexible tube 2c.

[0022] The tip portion 2a is provided with an imaging element, an imaging optical system, an illumination optical system, a nozzle 22a (see FIG. 8), a channel tip opening 21a (see FIG. 8), etc. The illumination optical system irradiates illumination light onto the subject. The imaging optical system forms an optical image of the subject. The imaging element photoelectrically converts the optical image formed by the imaging optical system to generate an imaging signal. The nozzle 22a discharges gas and liquid sent via the air / water supply channel 22 (see FIGS. 4, 6, 8, etc.) into an observation window at the tip of the imaging optical system. The channel tip opening 21a is an opening on the tip side of the treatment instrument channel 21 (see FIGS. 2, 4, 6, etc.).

[0023] The bending tube 2b is a section that can be bent in four directions, for example, up, down, left, and right. The bending tube 2b is also called a bending section. The bending tube 2b is provided along a longitudinal axis O (see FIGS. 2 and 3, etc.) that extends from the base end side to the tip end side of the endoscope 1.

[0024] The flexible tube 2c is a flexible tube portion and is also referred to as a flexible tube portion. The flexible tube 2c is provided on the proximal end side of the bending tube 2b along the longitudinal axis O. Note that here, an example is given in which the endoscope 1 is a flexible endoscope having the flexible tube 2c. However, the endoscope 1 may also be a rigid endoscope in which the portion corresponding to the flexible tube 2c is rigid.

[0025] The operation section 3 is provided on the proximal end side of the flexible tube 2c of the insertion section 2. The operation section 3 is a portion with which the user operates the endoscope 1. The operation section 3 includes a grip section 5, a bending operation knob 6, various operation switches 7, an air / water supply button 8a, a suction button 8b, and a treatment tool insertion port 9.

[0026] The grip portion 5 is a portion where the user grips the endoscope 1 in the palm of his / her hand.

[0027] The bending operation knob 6 is an operation device for operating the bending of the bending tube 2b. The bending operation knob 6 is operated, for example, by using the thumb of the hand holding the grip portion 5. When the bending operation knob 6 is operated, the bending wire 11 (see Figures 2, 3, etc.) is pulled, and the bending tube 2b is bent.

[0028] The bending operation knob 6 includes an up-down bending operation knob 6a and a left-right bending operation knob 6b. The up-down bending operation knob 6a is operated to bend the bending tube 2b upward and downward. The left-right bending operation knob 6b is operated to bend the bending tube 2b left and right.

[0029] When the bending tube 2b is bent, the direction of the distal end portion 2a changes. This changes the imaging direction of the imaging element and the imaging optical system, and the irradiation direction of the illumination light from the illumination optical system. The bending tube 2b is also bent to improve the insertability of the insertion portion 2 inside the subject.

[0030] The operation switches 7 include button switches related to image capture. Specific examples of the operation switches 7 are button switches such as a freeze button for pausing the monitor screen and a release button for capturing a still image.

[0031] The air and water supply button 8a is a button for supplying air and water to the observation window of the tip portion 2a. The observation window is cleaned by the water supply, and the liquid after cleaning is blown away by the air supply. The air and water supply are performed via the air and water supply channel 22.

[0032] The suction button 8b is a button for performing an operation to suction the inside of the subject from the distal end portion 2a. The suction from the inside of the subject is performed, for example, via the treatment instrument channel 21, which also serves as a suction channel. When the suction operation is performed, for example, liquid or mucous membrane is suctioned from the inside of the subject.

[0033] The treatment instrument insertion port 9 is an opening on the proximal end side of the treatment instrument channel 21. A treatment instrument such as forceps is inserted into the treatment instrument channel 21 from the treatment instrument insertion port 9. The tip of the treatment instrument is guided from the treatment instrument channel 21 to the channel tip side opening 21a and protrudes into the subject. Various treatments are performed on the subject using the protruding tip of the treatment instrument.

[0034] The universal cable 4 extends from, for example, the side surface of the base end of the operation unit 3. A connector is provided at the extending end of the universal cable 4. The connector connects the endoscope 1 to an endoscope processor (video processor), a light source device, a suction pump, a water tank, etc.

[0035] Fig. 2 is a cross-sectional view showing the configuration of the bending wire 11 at the connection portion between the bending tube 2b and the flexible tube 2c in the first embodiment. Fig. 3 is a partial perspective view showing the configuration of the bending wire 11, inner sheath 12, sheath 13, and plate body 14 in the first embodiment. Fig. 4 is a cross-sectional view of the bending tube 2b in the vicinity of the plate body 14, taken orthogonal to the longitudinal axis O. Fig. 4 is a view of the cross section viewed toward the distal end along the longitudinal axis O.

[0036] The wire 11 is configured to bend the bending tube 2b by being pulled or relaxed.

[0037] When the bending tube 2b can be bent in four directions, up, down, left, and right, the bending wires 11 include a wire 11u for upward bending, a wire 11d for downward bending, a wire 11l for left bending, and a wire 11r for right bending.

[0038] The upward bending wire 11u is pulled to bend the bending tube 2b upward. The downward bending wire 11d is pulled to bend the bending tube 2b downward. The left bending wire 11l is pulled to bend the bending tube 2b leftward. The right bending wire 11r is pulled to bend the bending tube 2b rightward.

[0039] The bending wires 11u, 11d, 11r, and 11l in each direction are slidably inserted into four inner sheaths 12 (second sheaths). Furthermore, the four inner sheaths 12 through which the bending wires 11u, 11d, 11r, and 11l are inserted are respectively inserted into four sheaths 13 (first sheaths). Therefore, the wires 11 are inserted into the sheaths 13 via the inner sheaths 12.

[0040] The inner sheath 12 is formed from a thermoplastic elastomer, which is a resin, and may be formed from, for example, a PTFE (polytetrafluoroethylene) or PP (polypropylene) based resin.

[0041] The sheath 13 is configured, for example, as an elastic coil sheath, and is assembled to the endoscope 1 in a state where it is compressed in the direction of the longitudinal axis O relative to its natural length. The sheath 13 configured as a coil sheath is coiled over its entire length, but the illustration is simplified as appropriate in the drawings, and the portion other than the end (near the plate member 14, etc.) is shown as cylindrical. However, only a portion of the entire length of the sheath 13 may be formed into a coil shape.

[0042] Here, the coefficient of friction between inner sheath 12 and wire 11 is smaller than the coefficient of friction between sheath 13 and wire 11. Furthermore, by providing inner sheath 12 that reduces friction, the use of lubricants such as silicone oil or carbon powder is unnecessary, and there is no need to ensure watertightness inside insertion portion 2, making this configuration suitable for manufacturing an inexpensive endoscope.

[0043] An annular plate member 14 is disposed on the proximal end side of the bending tube 2b. The plate member 14 is a ring member configured separately from the bending tube 2b.

[0044] 2 to 4, the plate member 14 has a first annular surface 14a on the distal end side, a second annular surface 14b on the proximal end side, and a hole 14c penetrating the first annular surface 14a and the second annular surface 14b. The second annular surface 14b is perpendicular to the longitudinal axis O.

[0045] At least a portion of the sheath 13 is disposed on the proximal end side of the plate member 14. In the example shown in Figures 2 and 3, the entire sheath 13 is disposed on the proximal end side of the plate member 14. The sheath 13 is assembled to the endoscope 1 in a compressed state as described above. Therefore, the distal end 13a of the sheath 13 presses the peripheral portion of the hole 14c in the second annular surface 14b due to the restoring force of the sheath 13 generated by compression.

[0046] That is, the tip 13a of the sheath 13 applies a normal force to the peripheral portion of the hole 14c in the second annular surface 14b, which generates a frictional force in a direction intersecting the longitudinal axis O between the tip 13a of the sheath 13 and the peripheral portion of the hole 14c in the second annular surface 14b.

[0047] At this time, because the second annular surface 14b is perpendicular to the longitudinal axis O, the tip 13a of the sheath 13 stably abuts against the second annular surface 14b. Therefore, the plate material 14 does not need to have a configuration such as a long hole through which the sheath 13 is inserted to stably abut the tip 13a against the second annular surface 14b, and the thickness of the plate material 14 in the direction of the longitudinal axis O can be made thinner. Note that, if necessary, the second annular surface 14b may be configured to intersect obliquely with the longitudinal axis O.

[0048] The plate material 14 is sandwiched between the tip 13a of the sheath 13 and the base end side of the bending tube 2b (for example, the guide member 16 arranged furthest from the base end side among the multiple guide members 16 arranged in the bending tube 2b).

[0049] The plate material 14 is neither welded nor adhered to the bending tube 2b. The plate material 14 abuts against the base end side of the bending tube 2b (butts against the base end side of the bending tube 2b) and is fixed to the base end side of the bending tube 2b by the pressing force received from the sheath 13. In this way, the plate material 14 functions as a sheath stopper plate that locks the tip 13a of the sheath 13.

[0050] The wire 11 inserted through the inner sheath 12 is inserted through the hole 14c, so that the tip 12a of the inner sheath 12 is positioned further forward than the hole 14c.

[0051] The portion of the inner sheath 12 that is inserted through the hole 14c of the plate member 14 is adhered to the hole 14c. The inner sheath 12 and the plate member 14 are unitized by adhesion. The plate member 14 functions as a member that fixes the distal end side of the inner sheath 12. The proximal end side of the inner sheath 12 is disposed within the operating unit 3 and is not fixed.

[0052] In this example, the distal end of the inner sheath 12 is fixed by adhesive to the hole 14c of the plate member 14 arranged in the bending tube 2b, and the proximal end is left free. This has the advantage of simplifying the manufacturing process for fixing the inner sheath 12.

[0053] However, the present invention is not limited to this configuration. For example, a configuration may be adopted in which the base end side of the inner sheath 12 is fixed to a member arranged inside the operation unit 3 (for example, a fixing member 31 shown in Figures 9 and 10 described later), and the tip side is left free. Furthermore, the inner sheath 12 may be left free and not fixed, provided that this does not cause any problems in use.

[0054] The bending tube 2b is provided with a plurality of guide members 16 (see FIG. 8, etc.) that hold (guide) the wire 11. For example, each of the plurality of guide members 16 also serves as a bending top. The guide member 16 arranged on the most proximal side of the bending tube 2b is connected to the flexible tube main body 2c1 of the flexible tube 2c, as shown in FIG.

[0055] The hole 14c is provided at a position on a plane perpendicular to the longitudinal axis O that is different from the position where the guide member 16 holds the wire 11.

[0056] The guide member 16 has, for example, a hole 16a that functions as a guide hole for the wire 11. The wire 11 is inserted through the hole 16a so as to be movable in a direction parallel to the longitudinal axis O. The position of the hole 16a in a plane perpendicular to the longitudinal axis O is the position where the guide member 16 holds the wire 11.

[0057] By making the position of the hole 14c of the plate material 14 and the position of the hole 16a of the guide member 16 different in a plane perpendicular to the longitudinal axis O (here, particularly the radial position centered on the longitudinal axis O), a swing angle is generated in the wire 11 entering the curved tube 2b from the flexible tube 2c.

[0058] This allows the wire 11 to have a swing angle without providing an oblique long hole in the plate material 14. Therefore, the thickness of the plate material 14 in the direction of the longitudinal axis O can be reduced. This reduces the length of the inflexible portion of the insertion portion 2 in the direction of the longitudinal axis O, improving the insertability of the insertion portion 2.

[0059] 2, in a plane perpendicular to the longitudinal axis O, the hole 14c is provided at a position closer to the longitudinal axis O than the position of the hole 16a through which the guide member 16 holds the wire 11. In this case, with the longitudinal axis O as the center, the hole 16a is positioned radially outward from the hole 14c.

[0060] As a result, when the wire 11 enters the bendable tube 2b from the flexible tube 2c, a swing angle toward the outer diameter occurs. Therefore, contact between the wire 11 and other built-in objects inside the bendable tube 2b can be more reliably avoided, including when the bendable tube 2b is bent.

[0061] 4, the width W14 of the peripheral portion of the hole 14c in the second annular surface 14b is equal to or greater than the width W13 of the tip 13a of the sheath 13. In this case, the entire surface of the tip 13a of the sheath 13 abuts against the second annular surface 14b. As a result, the tip 13a of the sheath 13 stably abuts against the second annular surface 14b.

[0062] FIG. 5 is a cross-sectional view of a modified example of the plate material 14 in the first embodiment, taken along a plane parallel to the longitudinal axis O. As shown in FIG.

[0063] 5 has a groove 14d formed in the second annular surface 14b on the base end side, around the periphery of the hole 14c. The groove 14d is configured so that the tip 13a of the sheath 13 abuts against it. By providing the groove 14d, it is possible to prevent the position at which the tip 13a abuts from shifting in a direction perpendicular to the longitudinal axis O, stabilizing the abutment.

[0064] FIG. 6 is a cross-sectional view showing, from an oblique direction, the configuration of the second plate member 15 arranged on the distal end side of the bending tube 2b in the first embodiment.

[0065] The endoscope 1 includes a second plate member 15 disposed on the distal end side of the bending tube 2b. The second plate member 15 is disposed so as to intersect with the longitudinal axis O. The second plate member 15 includes a distal surface 15a and a proximal surface 15b. The second plate member 15 is disposed on the distal end side of the bending tube 2b so that the distal surface 15a and the proximal surface 15b are, for example, perpendicular to the longitudinal axis O.

[0066] In this embodiment, the wire 11u for upward bending and the wire 11l for left bending are integrally connected at the distal end and constitute a single wire 11a. In other words, a portion of the single wire 11a functions as the wire 11u for upward bending, and another portion functions as the wire 11l for left bending.

[0067] Furthermore, the downward bending wire 11d and the right bending wire 11r are integrally connected at the distal end to form a single wire 11b. In other words, a portion of the single wire 11b functions as the downward bending wire 11d, and another portion functions as the right bending wire 11r.

[0068] Therefore, the bending wire 11 is configured to perform bending up and down and left and right by a total of two wires 11a and 11b.

[0069] In this configuration, the second plate member 15 further includes a plurality of holes that penetrate from the surface 15a on the distal end side to the surface 15b on the proximal end side.

[0070] Specifically, the second plate member 15 has, as the plurality of holes, four holes (however, the number is not limited to four, and may be two, or an even number of six or more) through which the wire 11a is inserted. The four holes are, in order around the longitudinal axis O (for example, clockwise in FIG. 6), a first hole 15u1, a second hole 15u2, a third hole 15l2, and a fourth hole 15l1.

[0071] The wire 11a is inserted from the base end side of the second plate material 15, with the wire 11u being inserted into the first hole 15u1, and then inserted into the second hole 15u2, the third hole 15l2, and the fourth hole 15l1 in that order, with the wire 11l being extended to the base end side of the second plate material 15.

[0072] Fig. 7 is a cross-sectional view showing the wire 11a inserted through four holes 15u1, 15u2, 15l2, and 15l1 of the second plate 15 in the first embodiment. Fig. 8 is a cross-sectional view showing two wires 11a and 11b inserted through two holes 15u1 and 15d1 of the second plate 15, respectively, in the first embodiment.

[0073] The wire 11a is inserted from the base end side of the insertion section 2 into the first hole 15u1 and extends to the distal end surface 15a as a first portion 11a1 of the wire 11a. The first portion 11a1 of the wire 11a is disposed circumferentially on the distal end surface 15a and is inserted into the second hole 15u2.

[0074] The wire 11a inserted through the second hole 15u2 extends to the base-side surface 15b as a second portion 11a2. The second portion 11a2 is disposed circumferentially around the base-side surface 15b and is inserted through a third hole 15l2.

[0075] The wire 11a inserted through the third hole 15l2 extends to the distal surface 15a as a third portion 11a3. The third portion 11a3 is disposed circumferentially around the distal surface 15a and is inserted through the fourth hole 15l1.

[0076] The wire 11a inserted through the fourth hole 15l1 is extended to the proximal end side of the insertion portion 2 as the wire 11l.

[0077] The second plate member 15 also has four holes (however, the number is not limited to four and may be two, or an even number of six or more) for inserting the wire 11b. The four holes are a first hole 15d1, a second hole 15d2, a third hole 15r2, and a fourth hole 15r1, arranged in order around the longitudinal axis O (for example, clockwise in FIG. 6).

[0078] Wire 11b is inserted from the base end side of second plate material 15, with wire 11d being inserted into first hole 15d1, and then through second hole 15d2, third hole 15r2, and fourth hole 15r1 in that order, with wire 11r extending out to the base end side of second plate material 15.

[0079] Although a cross-sectional view of the wire 11b is omitted, similar to the wire 11a shown in Fig. 7, the wire 11d is inserted from the base end side of the insertion section 2 into the first hole 15d1 and extends to the distal end surface 15a as a first portion 11b1 (see Fig. 6) of the wire 11b. The first portion 11b1 of the wire 11b is disposed circumferentially on the distal end surface 15a and is inserted into the second hole 15d2.

[0080] The wire 11b inserted through the second hole 15d2 extends to the base-side surface 15b as a second portion 11b2 (see FIG. 6). The second portion 11b2 is disposed circumferentially around the base-side surface 15b and is inserted through the third hole 15r2.

[0081] The wire 11b inserted through the third hole 15r2 extends to the distal end surface 15a as a third portion 11b3 (see FIG. 6). The third portion 11b3 is disposed circumferentially around the distal end surface 15a and is inserted through the fourth hole 15r1.

[0082] The wire 11b inserted through the fourth hole 15r1 is extended to the proximal end side of the insertion portion 2 by the wire 11r.

[0083] In this way, the wires 11a and 11b are each arranged in an M-shape with respect to the second plate member 15. Note that the second plate member 15 may be previously prepared with the wires 11a and 11b formed in an M-shape, and the bending wire 11 may be unitized. In this case, the unitized wire 11 is incorporated into the endoscope 1.

[0084] 8, the base end surface 15b of the second plate material 15 abuts against the guide member 16, which is disposed on the most distal end and also serves as a bending piece. By applying tension to the wires 11a and 11b in the tensile direction, the second plate material 15 is fixed to the guide member 16. In this case, there is no need to bond or weld the second plate material 15 to the guide member 16, which reduces manufacturing costs.

[0085] Furthermore, since the wires 11a and 11b are under tension, a frictional force acts between the wire 11a and the second plate material 15 in the M-shaped portion, and a frictional force acts between the wire 11b and the second plate material 15.

[0086] Therefore, pulling wire 11u does not pull wire 11l toward the distal end, and pulling wire 11l does not pull wire 11u toward the distal end. Similarly, pulling wire 11d does not pull wire 11r toward the distal end, and pulling wire 11r does not pull wire 11d toward the distal end. Therefore, second plate member 15 functions as a wire stop plate.

[0087] By configuring one wire 11a to function as both the wire 11u for upward bending and the wire 11l for left bending, and one wire 11b to function as both the wire 11d for downward bending and the wire 11r for right bending, the work of fixing the tips of the four wires to the tip side of the bending tube 2b (or the base end side of the tip portion 2a) is not necessary, and manufacturing costs can be reduced. Furthermore, by unitizing the two wires 11a and 11b and the second plate member 15, assembly time and assembly costs can be reduced.

[0088] Although the configuration described here is one in which bending in four directions is performed using two wires 11a and 11b, the endoscope 1 may also be configured to use a general configuration in which bending in four directions is performed using four individually provided bending wires.

[0089] Fig. 9 is a perspective view showing the fixing member 31 arranged in the operation unit 3 in the first embodiment. Fig. 10 is a cross-sectional view showing a part of the structure of the fixing member 31 in the first embodiment.

[0090] The operation unit 3 includes an operation unit main body 3a that also serves as an exterior. A fixing member 31 is fixed to the operation unit main body 3a using screws 32 or the like. The fixing member 31 bundles together built-in components such as the treatment instrument channel 21, the air / water supply channel 22, and a signal cable connected to the imaging element, and fixes their position within the operation unit 3.

[0091] The fixing member 31 has a receiving surface 31a. The receiving surface 31a is configured, for example, as a surface perpendicular to the longitudinal axis O. At least a portion of the sheath 13 is disposed on the distal end side of the receiving surface 31a.

[0092] 9 and 10, the entire sheath 13 is disposed on the distal side of the receiving surface 31a. In this case, the proximal end 13b of the sheath 13 abuts against the receiving surface 31a. The inner sheath 12 extends from the proximal end 13b of the sheath 13 toward the proximal end, and the proximal end 12b (see FIG. 9) of the inner sheath 12 is disposed closer to the proximal end than the fixing member 31. As described above, the proximal end side of the inner sheath 12 is not fixed within the operating unit 3.

[0093] The sheath 13 has one end abutting against the second annular surface 14b of the plate member 14 and the other end abutting against the receiving surface 31a, and is not fixed to any other member.

[0094] As described above, the sheath 13 is assembled in a compressed state to the endoscope 1. Therefore, the base end 13b of the sheath 13 presses the receiving surface 31a of the fixing member 31 due to the restoring force of the sheath 13 generated by the compression.

[0095] That is, the base end 13b of the sheath 13 applies a normal force to the receiving surface 31a, which generates a friction force in a direction intersecting the longitudinal axis O between the base end 13b of the sheath 13 and the receiving surface 31a.

[0096] At this time, since the receiving surface 31a is perpendicular to the longitudinal axis O, the base end 13b of the sheath 13 stably abuts against the receiving surface 31a. If necessary, the receiving surface 31a may be configured to be oblique to the longitudinal axis O.

[0097] The fixing member 31 further includes a retaining structure 31b. The retaining structure 31b is provided on the tip side of the receiving surface 31a of the fixing member 31. The retaining structure 31b abuts against the side surface of the sheath 13 to prevent buckling of the sheath 13. This prevents buckling of the sheath 13 and the inner sheath 12 and wire 11 inserted within the sheath 13, and does not interfere with bending operation using the bending operation knob 6.

[0098] The filling rate of the contents such as the treatment instrument channel 21 inside the flexible tube 2c is higher than the filling rate inside the operation section 3. Then, inside the flexible tube 2c, the other contents prevent the sheath 13 from shifting in a direction perpendicular to the longitudinal axis O. For this reason, a structure equivalent to the retaining structure 31b is not provided in the flexible tube 2c. In contrast, the operation section 3, which has a lower filling rate of the contents than the flexible tube 2c, has more space and is therefore provided with the retaining structure 31b.

[0099] However, if the sheath 13, the inner sheath 12, and the wire 11 do not shift in a direction perpendicular to the longitudinal axis O, the holding structure 31b of the operation unit 3 may be omitted.

[0100] FIG. 11 is a diagram showing how the position at which the sheath 13 is cut is set in accordance with the actual length of the flexible tube main body 2c1 in the first embodiment.

[0101] The actual length of the flexible tube main body 2c1 of the flexible tube 2c may differ from the designed length due to product variations.

[0102] The sheath 13 is manufactured by cutting a long coil sheath material. If the actual length of the flexible tube 2c differs from the designed length, and the sheath 13 is cut to the designed length, the sheath 13 may not be in an appropriate compressed state when assembled to the endoscope 1.

[0103] Therefore, the sheath 13 is cut to fit the actual length of the flexible tube main body 2c1 as shown in FIG.

[0104] In FIG. 11, one end of the manufactured flexible tube main body 2c1 is aligned with the start line LS, and the tip of the coil sheath material is aligned with the start line LS.

[0105] The design length of the flexible tube main body 2c1 is the length from the start line LS to the flexible tube design line LD1. However, in the illustrated example, the actual length of the flexible tube main body 2c1 is longer by a length L1 than the length from the start line LS to the flexible tube design line LD1.

[0106] On the other hand, the design length of the sheath 13 is the length from the start line LS to the sheath design line LD2. In this case, since the flexible tube main body 2c1 is longer than the design length by a length L1, the cutting line LC for cutting the sheath 13 is set at a position longer than the sheath design line LD2 by a length L1, and the longitudinal coil sheath material is cut.

[0107] By employing such a manufacturing method, when the sheath 13 is assembled to the endoscope 1, it is possible to maintain an appropriate compressed state even if there is variation in the length of the flexible tube main body 2c1 between products.

[0108] Fig. 12 is a side view showing the operation mechanism 33 arranged in the operation unit 3 in the first embodiment. Fig. 13 is a partial perspective view showing the operation mechanism 33 of the first embodiment from the direction of arrow A1 in Fig. 12.

[0109] The operating section 3 includes an operating mechanism 33 configured to receive an operation to pull or loosen the wire 11. The proximal end side of the wire 11 is fixed to the operating mechanism 33.

[0110] The operation mechanism 33 includes a pulley 34 and a pulley 35. The pulley 34 rotates around the rotation axis R in conjunction with the rotation operation of the up-down bending operation knob 6a. The pulley 35 rotates around the rotation axis R in conjunction with the rotation operation of the left-right bending operation knob 6b.

[0111] Although an example in which the operation mechanism 33 is linked to the bending operation knob 6 has been shown here, the present invention is not limited to this configuration. For example, the operation mechanism 33 may be configured to rotate electrically by an actuator or the like in response to the operation of a joystick, or any other appropriate configuration may be adopted.

[0112] A wire 11u for upward bending and a wire 11d for downward bending are wound around pulley 34, and the base ends of wire 11u and wire 11d are fixed. A wire 11r for right bending and wire 11l for left bending are wound around pulley 35, and the base ends of wire 11r and wire 11l are fixed.

[0113] The pulley 34 includes an upward bending wire winding chamber 34u and a downward bending wire winding chamber 34d that are positioned at different positions in the direction of the rotation axis R. The upward bending wire winding chamber 34u and the downward bending wire winding chamber 34d are separated from each other by, for example, a flange or the like sandwiched therebetween.

[0114] The pulley 35 is equipped with a right-bending wire winding chamber 35r and a left-bending wire winding chamber 35l that are located at different positions in the direction of the rotation axis R. The right-bending wire winding chamber 35r and the left-bending wire winding chamber 35l are separated from each other by, for example, a flange or the like sandwiched therebetween.

[0115] For example, as shown in Fig. 13, wire 11r and wire 11l are crossed on the base end side of pulley 35. After being crossed, wire 11r is wound once around wire winding chamber 35r for right bending and fixed to fixed portion 35a of pulley 35 by first knock pin 36. After being crossed, wire 11l is wound once around wire winding chamber 35l for left bending and fixed to fixed portion 35a of pulley 35 by second knock pin 36. With this configuration, wire 11r and wire 11l do not overlap, each transmitting a traction force and each being able to relax.

[0116] Wire 11u and wire 11d are also fixed to pulley 34 in the same manner as wire 11r and wire 11l. That is, wire 11u and wire 11d are crossed on the base end side of pulley 34. After being crossed, wire 11u is wound once around wire winding chamber 34u for upward bending and fixed to fixed portion 34a of pulley 34 by third knock pin 36. After being crossed, wire 11d is wound once around wire winding chamber 34d for downward bending and fixed to fixed portion 34a of pulley 34 by fourth knock pin 36. With this configuration, wire 11u and wire 11d do not overlap, and each can transmit traction force and each can be relaxed.

[0117] Here, standard general-purpose parts may be used as the first to fourth knock pins 36. By using general-purpose parts, the manufacturing costs of the endoscope 1 can be reduced compared to when dedicated parts are used.

[0118] As explained with reference to Figures 6 to 8, when wire 11u and wire 11l are formed by one wire 11a, one end (base end of wire 11u) of wire 11a is fixed to pulley 34, extended toward the tip side, inserted through flexible tube 2c and bending tube 2b, arranged in an M-shape on second plate material 15, extended toward the base end side, inserted through bending tube 2b and flexible tube 2c, and the other end (base end of wire 11l) is fixed to pulley 35.

[0119] Similarly, when wire 11d and wire 11r are formed by one wire 11b, one end (the base end of wire 11d) of wire 11b is fixed to pulley 34, extended toward the tip side, inserted through flexible tube 2c and bending tube 2b, arranged in an M-shape on second plate material 15, extended toward the base end side, inserted through bending tube 2b and flexible tube 2c, and the other end (the base end of wire 11r) is fixed to pulley 35.

[0120] FIG. 14 is a diagram for explaining a process of fixing the bending wire 11 to the operation mechanism 33 in the first embodiment.

[0121] As described above, the wire 11 is tensioned and fixed inside the endoscope 1. The wire 11 is fixed inside the endoscope 1, for example, by the following steps.

[0122] The bending tube mouthpiece 37 provided on the distal end side of the operation portion 3, the fixing member 31, and the operation mechanism 33 are fixed to a jig at positions spaced apart by a specified distance.

[0123] Furthermore, the fixed portions 34a and 35a of the operating mechanism 33 are brought into contact with a rotation-stopping jig 38 to hold the pulleys 34 and 35 in a state where they do not rotate.

[0124] Then, the base end side of the wire 11 is wound around a winding jig 39, and the winding jig 39 is rotated to wind up the base end side of the wire 11.

[0125] When the wire 11 is wound around the jig 39, the bending tube 2b is bent according to the amount of winding. When the bending tube 2b reaches its maximum bending state, the winding force of the jig 39 is adjusted so that the wire 11 is pulled with a constant tension.

[0126] In this state, the knock pin 36 is press-fitted into the fixing portions 34a and 35a to fix the base end side of the wire 11 in place.

[0127] By performing such an operation on each of the wires 11u, 11d, 11r, and 11l, a certain tension can be applied to each of the wires 11u, 11d, 11r, and 11l even when the bending tube 2b is in a straight state.

[0128] If a certain tension is not applied to the wire 11, there will be play. In this case, even if a bending operation is started, bending will not start until the wire 11 is stretched taut, and the responsiveness of bending to user operation will decrease.

[0129] In contrast, the wire 11 fixed in the above-described process is in a state where a certain tension is applied, so that no play occurs and bending can be performed with high responsiveness to user operation.

[0130] FIG. 15 is a diagram showing the first embodiment in which the sheath 13 is held in a state in which it presses the plate material 14 and the fixing member 31. As shown in FIG.

[0131] The sheath 13 has its tip 13a abutting against the second annular surface 14b of the plate material 14 and its base end 13b abutting against the receiving surface 31a of the fixing member 31, thereby pressing the plate material 14 and the fixing member 31 as shown by the double arrow.

[0132] As an example of a configuration that functions in this manner, the sheath 13 has been described above as a coil sheath in a compressed state. However, the sheath 13 is not limited to a coil sheath, and may have other elastic configurations. For example, the sheath 13 may be a tubular member made of elastic rubber.

[0133] Furthermore, the sheath 13 does not have to be made of a typical elastic material (a compressible material). For example, in a small-diameter endoscope, a thin-walled metal pipe may be used as the tubular member that forms the channel. Even if it is a metal pipe, if it can be assembled to the endoscope 1 with both ends pressed, it will generate a normal force against the plate member 14 and the fixing member 31, and a frictional force will be generated between the plate member 14 and the fixing member 31 in a direction intersecting the longitudinal axis O. Therefore, the sheath 13 may be a tubular member made of a hard material, such as a metal pipe.

[0134] FIG. 16 is a cross-sectional view showing the relationship between the sheath 13 and the wire 11 in the first embodiment when the inner sheath 12 is not provided.

[0135] When the wire 11 is pulled or relaxed, it moves in the direction of the longitudinal axis O. On the other hand, as shown in Figure 15, the sheath 13 is sandwiched between the plate member 14 and the fixing member 31 and does not move in the direction of the longitudinal axis O. Therefore, when the wire 11 is pulled or relaxed, a relative positional change occurs between the wire 11 and the sheath 13 in the direction of the longitudinal axis O.

[0136] 16, if the inner sheath 12 is not provided, when the relative positions of the wire 11 and the sheath 13 change, the wire 11 may come into contact with the surface of the wire of the sheath 13 configured as a coil sheath, causing friction and resulting in wear of the wire 11. Furthermore, when the relative positions of the wire 11 and the sheath 13 change, the wire 11 may come into contact with the edge at the end of the sheath 13, causing friction and resulting in wear of the wire 11.

[0137] In contrast, in this embodiment, as described above, the tip 12a of the inner sheath 12 is positioned distally of the hole 14c of the plate material 14, and the base end 12b is positioned proximally of the base end 13b of the sheath 13.

[0138] In other words, the inner sheath 12 is inserted through the entire length of the sheath 13, and the wire 11 does not come into direct contact with the sheath 13. Furthermore, as described above, the coefficient of friction between the inner sheath 12 and the wire 11 is smaller than the coefficient of friction between the sheath 13 and the wire 11.

[0139] This prevents the wire 11 from coming into contact with the surface or edge of the wires of the sheath 13 and becoming worn. Furthermore, when the wire 11 is pulled, an increase in force due to friction can be suppressed.

[0140] Furthermore, the tip 12a of the inner sheath 12 is positioned distal to the hole 14c, so that the wire 11 not only does not come into contact with the sheath 13, but also with the plate material 14. This prevents the wire 11 from coming into contact with the surface or edge of the plate material 14 and becoming worn.

[0141] As described above, the proximal end 12b of the inner sheath 12 is disposed closer to the proximal end than the fixing member 31. As a result, the wire 11 does not come into contact with the fixing member 31. This prevents the wire 11 from coming into contact with the surface or edge of the fixing member 31 and becoming worn.

[0142] According to the first embodiment, the sheath 13 is not fixed, but rather has one end pressing against the plate material 14 and the other end pressing against the fixing member 31. Therefore, when assembling the sheath 13 to the endoscope 1, welding work using a jig by a skilled worker and adhesive work are not required. This results in an endoscope 1 that is suitable for inexpensive production and includes a sheath 13 through which the bending wire 11 is inserted.

[0143] Furthermore, since plate 14 is fixed by the pressing force of sheath 13 and second plate 15 is fixed by the tension of wire 11, neither welding nor bonding is required, which makes it possible to manufacture endoscope 1 at lower cost.

[0144] Furthermore, by differentiating the position of the hole 14c in the plate material 14 from the position of the hole 16a in the guide member 16, a swing angle is provided to the wire 11. This makes it possible to arrange the wire 11 differently in the bending tube 2b and in the flexible tube 2c, increasing the degree of freedom in arranging the built-in components.

[0145] [Second embodiment] 17 is a diagram showing an example of the configuration of a sheath 13 in a second embodiment of the present invention. In the second embodiment, parts that are the same as those in the first embodiment are given the same reference numerals, and descriptions thereof will be omitted as appropriate. In the second embodiment, differences from the first embodiment will be mainly described.

[0146] A portion 13x of the sheath 13 is disposed on the proximal side of the second annular surface 14b of the plate material 14, and another portion 13y is disposed on the distal side of the second annular surface 14b of the plate material 14. The length of the portion 13x in the direction of the longitudinal axis O is longer than that of the other portion 13y.

[0147] A flange 13f protruding in the outer diameter direction is provided at the tip of the portion 13x of the sheath 13. Therefore, the position where the flange 13f is provided is on the tip side of the sheath 13, but is not at the tip 13a of the entire sheath 13.

[0148] The flange 13f of the sheath 13 abuts against the second annular surface 14b and presses against the plate material 14. The surface of the flange 13f that abuts against the second annular surface 14b is the tip 13a' of the part 13x of the sheath 13. Therefore, the tip 13a' of the part 13x of the sheath 13 is the part that presses against the plate material 14.

[0149] In place of the flange 13f, a protrusion or the like protruding from the sheath 13 in the outer diameter direction may be provided, and the plate material 14 may be pressed by the protrusion or the like.

[0150] Furthermore, when the sheath 13 is made of a non-compressible material, a separate elastic member may be provided to press the flange 13f against the plate material 14.

[0151] Furthermore, instead of using the flange 13f to press the plate material 14, it is also possible to bond a portion of the outer circumferential surface of the sheath 13 integrally to the plate material 14, so that the sheath 13 presses the plate material 14.

[0152] According to the second embodiment, even when a portion other than the tip 13a of the entire sheath 13, that is, the tip 13a′ of the part 13x of the sheath 13 arranged on the base end side of the plate material 14, is configured to push the plate material 14, substantially the same effect as in the first embodiment described above can be achieved.

[0153] [Third embodiment] 18 and 19 show a third embodiment of the present invention. In the third embodiment, parts that are the same as those in the first and second embodiments are given the same reference numerals, and descriptions thereof will be omitted as appropriate. In the third embodiment, differences from the first and second embodiments will be mainly described.

[0154] As described above, by making the position of the hole 14c of the plate member 14 and the position of the hole 16a of the guide member 16 different, the wire 11 can be given a swing angle.

[0155] FIG. 18 is a diagram showing a first example of the swing angle of the wire 11 in the third embodiment.

[0156] In a plane perpendicular to the longitudinal axis O, the hole 14c of the plate member 14 is provided at a position where the guide member 16 holds the wire 11, that is, at a position closer to the longitudinal axis O than the hole 16a of the guide member 16. The swing angle of the first example shown in Fig. 18 is substantially the same as the swing angle of the wire 11 described in the first embodiment.

[0157] In this case, the swing angle of the wire 11 becomes an angle toward the outer diameter side when moving from the flexible tube 2c side toward the bending tube 2b side. By swinging the wire 11 toward the outer diameter side to widen the internal space of the bending tube 2b, the degree of freedom in arranging the built-in items inside the bending tube 2b can be increased.

[0158] FIG. 19 is a diagram showing a second example of the swing angle of the wire 11 in the third embodiment.

[0159] In a plane perpendicular to the longitudinal axis O, the hole 14c of the plate member 14 is provided at a position where the guide member 16 holds the wire 11, that is, at a position farther from the longitudinal axis O than the hole 16a of the guide member 16.

[0160] In this case, the swing angle of the wire 11 becomes an angle toward the inner diameter side when moving from the flexible tube 2c side toward the bending tube 2b side. The bending tube 2b has a thick outer skin, and the outer diameter tends to increase. Therefore, by swinging the wire 11 toward the inner diameter side and narrowing the inside of the bending tube 2b, it is possible to prevent the outer diameter of the bending tube 2b from increasing.

[0161] In the above description, the radial positions of the holes 14c and 16a are shifted, but the present invention is not limited to this, and the circumferential positions of the holes 14c and 16a may be shifted. In this case, it is easy to adjust the arrangement of the built-in components.

[0162] According to the third embodiment, substantially the same effects as those of the first and second embodiments described above are achieved.

[0163] Furthermore, according to the third embodiment, by providing a swing angle to the wire 11, the degree of freedom in arranging the built-in items is increased, the adjustment of the arrangement of the built-in items is made easier, or the outer diameter of the bending tube 2b can be prevented from increasing.

[0164] [Fourth embodiment] 20 shows a fourth embodiment of the present invention. In the fourth embodiment, parts that are the same as those in the first to third embodiments are given the same reference numerals, and descriptions thereof will be omitted as appropriate. In the fourth embodiment, differences from the first to third embodiments will be mainly described.

[0165] FIG. 20 is a diagram showing an example of the configuration of the sheath 13 in the fourth embodiment.

[0166] A portion 13x' of the sheath 13 is disposed on the distal side of the receiving surface 31a of the fixing member 31, and another portion 13y' is disposed on the proximal side of the receiving surface 31a of the fixing member 31. The length of the portion 13x' in the direction of the longitudinal axis O is longer than that of the other portion 13y'.

[0167] A flange 13g protruding in the outer diameter direction is provided at the proximal end of the portion 13x' of the sheath 13. Therefore, the position where the flange 13g is provided is on the proximal end side of the sheath 13, but not at the proximal end 13b of the entire sheath 13.

[0168] The flange 13g of the sheath 13 abuts against the receiving surface 31a of the fixing member 31, and presses the fixing member 31. The surface of the flange 13g that abuts against the receiving surface 31a is the base end 13b' of the portion 13x' of the sheath 13. Therefore, the base end 13b' of the portion 13x' of the sheath 13 is the portion that presses the fixing member 31.

[0169] In place of the flange 13g, a protrusion or the like protruding from the sheath 13 in the outer diameter direction may be provided, and the fixing member 31 may be pressed by the protrusion or the like.

[0170] Furthermore, when the sheath 13 is made of a non-compressible material, a separate elastic member may be provided to press the flange 13g against the fixing member 31.

[0171] Furthermore, the sheath 13 may have both the flange 13f shown in FIG. 17 and the flange 13g shown in FIG.

[0172] According to the fourth embodiment, even when a portion other than the base end 13b of the entire sheath 13, that is, the base end 13b' of the part 13x of the sheath 13 arranged on the tip side of the fixing member 31, is configured to press the fixing member 31, substantially the same effects as those of the first to third embodiments described above can be achieved.

[0173] [Fifth embodiment] 21 shows a fifth embodiment of the present invention. In the fifth embodiment, parts that are the same as those in the first to fourth embodiments are given the same reference numerals, and descriptions thereof will be omitted as appropriate. In the fifth embodiment, differences from the first to fourth embodiments will be mainly described.

[0174] FIG. 21 is a diagram showing an example of the configuration of the portion of the second annular surface 14b of the plate member 14 with which the tip end 13a of the sheath 13 abuts in the fifth embodiment.

[0175] As described above, the plate material 14 is formed as a ring member so that the internal objects can be inserted therethrough. In this case, it is preferable that the ring width of the plate material 14 in a plane perpendicular to the longitudinal axis O is small so as not to hinder the insertion of the internal objects.

[0176] However, the plate material 14 is subjected to a pushing force from the tip 13a of the sheath 13. For this reason, it is preferable that the width W14 of the portion of the plate material 14 that contacts the tip 13a be equal to or greater than the width (outer diameter) W13 of the tip 13a of the sheath 13. In the example shown in column A of FIG. 21, the plate material 14 is configured so that W14≧W13 (particularly in the illustrated example, W14>W13). However, the width of the plate material 14 other than the portion that contacts the tip 13a is smaller than W14. Therefore, the portion of the plate material 14 with width W14 has a shape that protrudes in the inner diameter direction.

[0177] According to the configuration example shown in column A of FIG. 21, it is possible to improve the ease of insertion of the contained object and also ensure that the plate material 14 receives a stable pressing force from the tip 13a of the sheath 13.

[0178] In addition, in the example shown in column B of Fig. 21, the width of the portion of the plate material 14 with which the tip 13a abuts is made smaller than that in column A of Fig. 21. In this case, the entire tip 13a does not abut against the second annular surface 14b of the plate material 14, but only a portion of the tip 13a abuts against the second annular surface 14b.

[0179] In the configuration of column A in Fig. 21, the tip 13a abuts against the second annular surface 14b in a circular shape, but in the configuration of column B in Fig. 21, the tip 13a abuts against the second annular surface 14b in a D-shape (the shape of a part of a circular arc). If the plate material 14 can receive a stable pressing force from the tip 13a of the sheath 13, the configuration shown in column B in Fig. 21 may be adopted.

[0180] 21, it is possible to reduce the packing ratio of the contents inserted into the plate material 14. Furthermore, it is possible to reduce the amount of material used to manufacture the plate material 14.

[0181] On the other hand, the example shown in column C of Fig. 21 is an example in which the width of the plate material 14 in a plane perpendicular to the longitudinal axis O is a constant width equal to or greater than the width of the tip 13a of the sheath 13. If there is ample space inside the flexible tube 2c and no obstacles arise in inserting the contained object, the configuration shown in column C of Fig. 21 may be adopted. According to the configuration example shown in column C of Fig. 21, when forming four holes 14c in the plate material 14, the work of aligning them with the wide portions of the ring is not required.

[0182] According to the fifth embodiment, substantially the same effects as those of the first to fourth embodiments described above are achieved.

[0183] Furthermore, according to the fifth embodiment, it is possible to select a plate material 14 having an appropriate configuration depending on the stability of the fit between the sheath 13 and the plate material 14, the need to reduce the filling rate of the contents, the ease of the work of forming holes 14c in the plate material 14, and the like.

[0184] It should be noted that the present invention is not limited to the above-described embodiments. In the implementation stage, the components of the present invention can be modified and embodied without departing from the spirit of the invention. Furthermore, various aspects of the invention can be formed by appropriately combining multiple components disclosed in the above embodiments. For example, some components may be omitted from all the components disclosed in the embodiments. Furthermore, components from different embodiments may be appropriately combined. In this way, it goes without saying that various modifications and applications are possible within the spirit of the invention. [Explanation of symbols]

[0185] 1. Endoscope 2...Insertion section 2a...Tip 2b...Bent pipe 2c…Flexible tube 2c1…Flexible tube body 3...Operation unit 3a...Operation unit main body 4...Universal cable 5...Gripping part 6...Bending control knob 6a...Up / down bending control knob 6b...Left and right bending control knob 7...Operation switch 8a…Air and water supply button 8b...Suction button 9...Treatment tool insertion port 11...Wire 11a, 11b...Wire 11u, 11d, 11r, 11l...wire 12...Inner sheath 13...Sheath 14...Plate material 15...Second board 16...Guide member 21...Treatment tool channel 21a...Channel tip opening 22...Air and water supply channel 22a...Nozzle 31...Fixing member 34, 35...Pulley 34a, 35a…Fixed part 34d... Wire winding chamber for lower bending 34u... Wire winding chamber for upper curve 35l...Left-bend wire winding chamber 35r...Right-bend wire winding chamber 36...Knock pin 37...Bend pipe nozzle 38...Jig (for preventing rotation) 39...Jig (for winding)

Claims

1. a bending tube provided along a longitudinal axis extending from a base end side to a tip end side; a wire configured to be pulled or relaxed to bend the bending tube; a first sheath through which the wire is inserted; an annular plate member disposed on the base end side of the bending tube, The plate material is the first annular surface on the tip side; a second annular surface on the proximal side perpendicular to the longitudinal axis; a hole penetrating the first annular surface and the second annular surface and through which the wire is inserted; At least a portion of the first sheath is disposed on the base end side of the plate member, and a tip end of the at least portion presses a peripheral portion of the hole in the second annular surface. An endoscope characterized by:

2. The first sheath has elasticity, and a restoring force generated when the first sheath is compressed in the direction of the longitudinal axis causes the tip of at least a portion of the first sheath to press against a peripheral portion of the hole in the second annular surface. The endoscope according to claim 1 .

3. The first sheath is a coil sheath.

3. The endoscope according to claim 2.

4. The device further includes a second sheath that is inserted through the first sheath and through which the wire is inserted; The second sheath is inserted through the hole, and the tip of the second sheath is disposed distally of the hole. The endoscope according to claim 1 .

5. The second sheath has a portion that is inserted through the hole and is adhered to the hole.

5. The endoscope according to claim 4.

6. The coefficient of friction between the second sheath and the wire is smaller than the coefficient of friction between the first sheath and the wire.

5. The endoscope according to claim 4.

7. The second sheath is made of resin. The endoscope according to claim 6 .

8. The first sheath is entirely disposed on the base end side of the plate member, and the tip of the first sheath presses the peripheral portion of the hole in the second annular surface. The endoscope according to claim 1 .

9. a width of a peripheral portion of the hole in the second annular surface is equal to or greater than a width of a tip end of the first sheath; The entire surface of the tip of the first sheath abuts against the second annular surface. The endoscope according to claim 8 .

10. the bending tube includes a guide member that holds the wire, In a plane perpendicular to the longitudinal axis, the hole is provided at a position different from a position where the guide member holds the wire. The endoscope according to claim 1 .

11. In a plane perpendicular to the longitudinal axis, the hole is provided at a position closer to the longitudinal axis than a position where the guide member holds the wire. The endoscope according to claim 10.

12. In a plane perpendicular to the longitudinal axis, the hole is provided at a position farther from the longitudinal axis than a position where the guide member holds the wire. The endoscope according to claim 10.

13. a flexible tube provided along the longitudinal axis on the base end side of the bending tube; an operation unit provided on the base end side of the flexible tube, the operating unit includes a fixed member having a receiving surface perpendicular to the longitudinal axis, At least a portion of the first sheath is disposed on the distal side of the receiving surface, and a proximal end of the at least portion presses against the receiving surface. The endoscope according to claim 1 .

14. The first sheath is entirely disposed on the distal end side of the receiving surface, and the proximal end of the first sheath presses against the receiving surface. The endoscope according to claim 13 .

15. The fixing member is in contact with the side surface of the first sheath at the distal end side of the receiving surface, and Equipped with a holding structure to prevent buckling of the sheath The endoscope according to claim 13 .

16. The operating unit includes an operating mechanism configured to receive an operation for pulling or loosening the wire, The proximal end of the wire is fixed to the operating mechanism. The endoscope according to claim 13 .

17. the operating mechanism includes a pulley around which the wire is wound; The base end of the wire is fixed to the pulley by a knock pin.

17. The endoscope according to claim 16.

18. a second plate member disposed on the distal end side of the bending tube so as to intersect with the longitudinal axis; the second plate member includes, in order around the longitudinal axis, a first hole, a second hole, a third hole, and a fourth hole penetrating a distal end surface and a proximal end surface of the second plate member; The wire is inserted from the base end side of the second plate member through the first hole, the second hole, the third hole, and the fourth hole in that order, and is extended to the base end side of the second plate member. The endoscope according to claim 1 .

19. a bending tube provided along a longitudinal axis extending from a base end side to a tip end side; a wire configured to be pulled or relaxed to bend the bending tube; a first sheath through which the wire is inserted; an annular plate member disposed on the base end side of the bending tube, The plate material is the first annular surface on the tip side; a second annular surface on the proximal side perpendicular to the longitudinal axis; a hole penetrating the first annular surface and the second annular surface and through which the wire is inserted; At least a portion of the first sheath is disposed on the base end side of the plate member, and a tip end of the at least portion generates a friction force in a direction intersecting the longitudinal axis between the tip end and a peripheral portion of the hole in the second annular surface. An endoscope characterized by:

20. a bending tube provided along a longitudinal axis extending from a base end side to a tip end side; a wire configured to be pulled or relaxed to bend the bending tube; a first sheath; and a second sheath that is inserted through the first sheath and through which the wire is inserted; an annular plate member disposed on the base end side of the bending tube, The plate material is the first annular surface on the tip side; the proximal second annular surface; a hole penetrating the first annular surface and the second annular surface and through which the wire is inserted; At least a portion of the first sheath is disposed on the base end side of the plate member, and a tip end of the at least portion presses a peripheral portion of the hole in the second annular surface; The wire and the second sheath are inserted through the hole, and the tip of the second sheath is disposed distally of the hole. An endoscope characterized by:

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