JP2020005763A - Insertion device - Google Patents

Abstract

To provide an insertion device that hardly causes a pitch deviation at a connection part of element wires even when compression force is applied to a coil pipe in an axial direction.SOLUTION: An insertion device includes an insertion part inserted into a subject, a wire 10 disposed in the insertion part, and a coil pipe 20 disposed in the insertion part, which is formed by the winding of element wires 50, and into which the wire 10 is inserted. A cross section of the element wires 50 along an axial direction of the coil pipe 20 includes a contact part 52 where the element wires 50 adjacent in an axial direction come in contact with each other, and all of the contact parts 52 are formed planarly.SELECTED DRAWING: Figure 3

Description

  The present invention relates to an insertion device that is arranged in an insertion portion to be inserted into a subject and is formed by winding a wire, and further has a coil pipe into which a traction member is inserted.

  2. Description of the Related Art In recent years, an insertion device, such as an endoscope, inserted into a subject has been widely used in the medical field and the industrial field. The endoscope can perform observation, treatment, and the like of a test site in the subject by inserting the elongated insertion portion into the subject.

  Here, a configuration in which a bending portion that can be bent in, for example, a plurality of directions is provided in an insertion portion of an endoscope is well known.

  The bending portion improves the progress of the insertion portion at the bending portion in the conduit, and also has a tip portion connected to a longitudinal end (hereinafter, simply referred to as a tip) of the insertion portion at the bending portion in the insertion portion. The observation direction of the observation optical system provided in the camera is changed.

  Usually, the bending portion is configured such that a plurality of bending pieces are connected along the longitudinal axis direction of the insertion portion, so that the bending portion can be freely bent in, for example, four directions of up, down, left, and right or two directions of up, down, or left and right.

  Specifically, when the bending portion is bent in four directions, four wires are inserted in the insertion portion so as to be movable back and forth in the longitudinal axis direction. In addition, each wire has its distal end fixed to the bending piece located on the distal end side (hereinafter, simply referred to as the distal end side) in the longitudinal axis direction among a plurality of bending pieces. When one of the four wires is towed using a knob or the like provided on the operation unit, the bending unit is bendable in any of up, down, left, and right directions.

  In the insertion portion, a flexible tube is provided at a base end of the bending portion in the longitudinal axis direction (hereinafter, simply referred to as a base end) and a flexible tube elongated in the longitudinal axis direction.

  Further, a configuration in which four coil pipes in which element wires are spirally wound closely along a longitudinal axis direction in a flexible tube is well known. A wire is inserted through each of the coil pipes, a distal end of each of the coil pipes is fixed to a distal end of the flexible tube, and a proximal end is fixed within the operation unit.

  Each coil pipe has a function of guiding each wire so as to be movable along the axial direction of the coil pipe without being shifted in the radial direction and the circumferential direction of the flexible tube.

  Further, when the bending portion is bent due to the pulling of each wire, each of the coil pipes is compressed in the axial direction by fixing the distal end and the proximal end, so that even the flexible tube is bent. It also has a function of preventing bending.

  Here, the coil pipe is generally formed by winding a wire having a circular cross section along the axial direction to a length extending from the distal end of the above-described flexible tube to the inside of the operation section. .

  If the cross section of the wire is formed in a circular shape, the inner peripheral surface of the coil pipe has a curved shape after winding, so that the contact area with the wire inserted in the coil pipe becomes smaller, so that the wire There is an advantage that the sliding resistance is reduced and the amount of pulling operation force of the wire is reduced.

  However, if the cross section of the wire is circular, not only the outer diameter of the coil pipe becomes large, but also the curved surfaces come into contact with each other at the contact portion in the axial direction between the wires.

  For this reason, when the flexible tube meanders, a so-called pitch shift occurs in which the other wire shifts in a direction different from the axial direction with respect to the one wire at the contact portion, and the durability of the coil pipe increases. There is a problem that the property is reduced.

  In view of such a problem, in Patent Literature 1, after winding, the outer diameter of the coil pipe is reduced, and a wire in which a pitch shift hardly occurs at each contact portion between the wires along the axial direction. Are disclosed. Specifically, in the strands adjacent to each other in the axial direction, the cross section of the strand is formed in a shell shape so that the curved surface formed on the other strand is in contact with the plane formed on the other strand. Disclosed is a configuration of a coil pipe.

JP 2015-104388 A

  By the way, when the wire is pulled and the coil pipe is compressed in the axial direction, a torsional moment is applied to the element wire and a rotational force is applied, and the element is brought into contact with the element along the axial direction. It is also applied to the contact portion between the lines.

  Therefore, when the cross section of the wire is formed in a circular shape and the curved surfaces of the wire are in contact with each other at the contact portion, the cross section of the wire disclosed in Patent Document 1 is formed in a shell shape, and the contact portion has one side. In the case where the curved surface of the other wire is in contact with the plane of the other wire, if a rotational force is applied to the contact portion, the contact area at the contact portion is small, so that a pitch shift still occurs. There was such a problem.

  The above problem is not limited to the endoscope, but also applies to other insertion devices such as a treatment tool having a wire and a coil pipe in a flexible tube.

  The present invention has been made in view of the above problems, and an insertion device having a configuration in which a pitch shift is difficult to occur at a contact portion between wires even when a compressive force is applied to a coil pipe in an axial direction. The purpose is to provide.

  In order to achieve the above object, an insertion device according to one aspect of the present invention includes an insertion portion to be inserted into a subject, a traction member disposed in the insertion portion, and a wire wound in the insertion portion. And a coil pipe through which the traction member is inserted, and a cross section of the element wire along the axial direction of the coil pipe is formed between the element wires adjacent in the axial direction. Has a contact portion with which all of the contact portions come into contact with each other.

  ADVANTAGE OF THE INVENTION According to this invention, even if a compressive force is provided to a coil pipe in an axial direction, the insertion apparatus provided with the structure with which a pitch shift | offset | difference does not easily occur in the contact part of strands can be provided.

FIG. 2 is a diagram illustrating an appearance of the endoscope according to the first embodiment. Partial sectional view of the insertion section taken along line II-II in FIG. Partial sectional view along the longitudinal axis direction of the coil pipe and wire along the line III-III in FIG. FIG. 3 is a partial cross-sectional view along the axial direction showing a state where the wire is pulled and pulled into the coil pipe when the coil pipe of FIG. 3 is bent. FIG. 3 is a diagram schematically comparing the cross-section of the strand of FIG. 3 with a conventional circular cross-section of a strand. FIG. 3 is a partial cross-sectional view along the axial direction of a coil pipe showing a modification in which the radius of curvature of the distal-side connecting portion and the proximal-side connecting portion is different in the first connecting portion of FIG. 3. FIG. 4 is a partial cross-sectional view of a coil pipe and a wire provided in an insertion portion of an endoscope according to a second embodiment along an axial direction of the wire.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. Hereinafter, the insertion device will be described using an endoscope as an example.

(1st Embodiment)

  FIG. 1 is a diagram illustrating an appearance of an endoscope according to the present embodiment.

  As shown in FIG. 1, an endoscope 1 includes an insertion portion 2 to be inserted into a subject, an operation portion 3 connected to a base end of the insertion portion 2, and an extension from the operation portion 3. A main part is configured by including a universal cord 8 and a connector 9 provided at an extending end of the universal cord 8. Note that the endoscope 1 is electrically connected to an external device such as a control device or a lighting device via the connector 9.

  The insertion section 2 includes a long flexible tube 2k having flexibility and extending along the longitudinal axis direction N of the insertion section 2, and a curved section 2w connected to the distal end of the flexible tube 2k. And a leading end portion 2s connected to the leading end of the curved portion 2w to form a main portion.

  An imaging unit (not shown) for imaging the inside of the subject, a lighting unit (not shown) for supplying illumination light to the inside of the subject, and the like are provided in the distal end portion 2s.

  The bending section 2w can be bent in four directions, for example, up, down, left and right, by bending operation knobs 4 and 6 provided on the operation section 3.

  Specifically, the operation section 3 is provided with a bending operation knob 4 for bending the bending section 2w in the vertical direction and a bending operation knob 6 for bending the bending section 2w in the left and right direction.

  In addition, by rotating together with the bending operation knob 4 in the operation section 3, the wires 10 u and 10 d (see FIG. 2), which will be described later, inserted through the insertion section 2 and the operation section 3 are pulled and loosened to bend. An up / down bending pulley (not shown) for bending the portion 2w in the vertical direction is provided.

  Further, by rotating together with the bending operation knob 6 in the operation section 3, wires 10r and 101 (described later, see FIG. 2, the wire 10r) inserted into the insertion section 2 and the operation section 3 are inserted. A pulley for bending left and right is provided that bends and relaxes the bending portion 2w in the left and right direction.

  In addition, since the structure of the pulley for bending up and down and the pulley for bending left and right is well known, detailed description using drawings is omitted.

  The operating section 3 is provided with a fixed lever 5 for fixing the turning position of the bending operation knob 4 and a fixing knob 7 for fixing the turning position of the bending operation knob 6.

  Next, the configuration of a main part according to the present embodiment on the distal end side of the insertion section in FIG. 1 will be described with reference to FIG. FIG. 2 is a partial cross-sectional view of the insertion portion along the line II-II in FIG.

  As shown in FIG. 2, a plurality of tubular bending pieces 11 are provided inside the bending portion 2 w and connected along the longitudinal axis direction N. Note that the plurality of bending pieces 11 are rotatably connected to adjacent pieces in the longitudinal axis direction N by rivets 12 so as to be able to bend in four directions, up, down, left, and right.

  The outer periphery of the plurality of bending pieces 11 is covered with a blade 16, and the outer periphery of the blade 16 is covered with a curved rubber 17.

  In the insertion section 2 and the operation section 3, for example, four pulling members 10r, 10l, 10u, and 10d (wires) that are movable in the front N1 and the rear N2 in the longitudinal axis direction N in which the bending section 2w is bent. 10r are not shown), but are inserted by being shifted from each other by about 90 ° in the circumferential direction of the insertion portion 2.

  The distal ends of the wires 10r to 10d are fixed to the bending piece 11a located at the most distal end side among the plurality of bending pieces 11 provided in the bending portion 2w.

  Further, tubular guides 15r, 15l, 15u, 15d (which hold the wires 10r to 10d such that the wires 10r to 10d are located along the inner peripheral surface of each bending piece 11 and are offset from each other by approximately 90 ° in the circumferential direction. Guides 15r are not shown), but a plurality of guides 15r are fixed to the inner peripheral surface of each bending piece 11.

  Specifically, the guides 15r to 15d are also fixed by being shifted by about 90 ° in the circumferential direction, the wire 10r is inserted into the plurality of guides 15r, and the wire 10l is inserted into the plurality of guides 15l. The wire 10u is inserted through the plurality of guides 15u, and the wire 10d is inserted through the plurality of guides 15d.

  The base ends of the two wires 10u and 10d for up and down bending are wound around the pulleys for up and down bending, and the base ends of the two wires 10r and 10l for left and right bending are It is wound on a bending pulley.

  That is, when the bending operation knob 4 is operated, one of the two vertical wires 10u and 10d is moved to the rear N2 and the other is moved to the front N1 by the vertical bending pulley. Is pulled and the other is relaxed, so that the bending portion 2w bends in one of the upper and lower directions.

  When the bending operation knob 6 is operated, one of the two left and right wires 10r and 10l is moved to the rear N2 and the other is moved to the front N1 by the left and right bending pulleys. Is pulled and the other is relaxed, whereby the bending portion 2w bends in either the left or right direction.

  The distal end side of the connecting member 18 is fixed to the inner circumference of the bending piece 11z located at the most proximal side of the bending piece 11, and the inner circumference of the proximal end side of the connecting member 18 is flexible. The tip side of the blade constituting the tube 2k is fixed.

  The blade is composed of a spiral tube 25 made of, for example, metal and a mesh tube 26 coated on the outer periphery of the spiral tube 25, and an outer tube 27 is coated on the outer periphery of the mesh tube 26. ing.

  Also, on the outer periphery of each of the four wires 10r to 10d inserted into the flexible tube 2k, for example, coil pipes 20r, 201, 20u, 20d (coil pipes) which are flexible and elongated in the longitudinal axis direction N are provided. 20r is not shown).

  That is, in the flexible tube 2k, four coil pipes 20r to 20d are inserted at positions shifted from each other by approximately 90 ° in the circumferential direction of the flexible tube 2k.

  The tip of each of the coil pipes 20r to 20d is fixed to the tip of the flexible tube 2k, specifically, to the connecting member 18 by, for example, brazing. Furthermore, the base ends of the coil pipes 20r to 20d are fixed in the operation unit 3.

  Each of the coil pipes 20r to 20d can be compressed by being compressed in the longitudinal axis direction N by fixing the distal end and the proximal end when the bending portion 2w is bent due to the pulling of the wires 10r to 10d. It has a function of preventing even the flexible tube 2k from bending together with the bending portion 2w.

  The coil pipes 20r to 20d are formed of coils in which, for example, a stainless steel wire 50 (see FIG. 3), which is a flexible material, is densely wound along the longitudinal axis direction N.

  The reason why each of the coil pipes 20r to 20d is made of a flexible coil is that if the outer circumference of each of the wires 10r to 10d is covered with, for example, a hard metal pipe, the flexibility of the flexible tube 2k decreases. This is because

  Therefore, each of the coil pipes 20r to 20d does not reduce the flexibility of the flexible tube 2k, and has a compressive force acting along the axial direction W of each of the coil pipes 20r to 20d when the bending portion 2w is bent. It may be composed of anything other than a coil as long as it can withstand the above. Note that the axial direction W of each of the coil pipes 20r to 20d in an unbent state substantially coincides with the longitudinal axis direction N.

  Next, the wire shape of each of the coil pipes 20r to 20d will be described with reference to FIGS.

  3 is a partial cross-sectional view of the coil pipe and the wire along the line III-III in FIG. 2 along the axial direction. FIG. 4 is a diagram illustrating a state in which when the coil pipe of FIG. FIG. 5 is a partial cross-sectional view along the axial direction showing a state of being drawn into the pipe, and FIG. 5 is a diagram schematically comparing the cross section of the strand of FIG. 3 with a conventional circular strand.

  Hereinafter, in order to briefly describe the wire shapes of the wires 10r to 10d and the coil pipes 20r to 20d, the wires 10r to 10d and the coil pipes 20r to 20d are shown as the wire 10 and the coil pipe 20. That is, what is shown as the wire 10 and the coil pipe 20 shows the configuration of the wires 10r to 10d and the coil pipes 20r to 20d.

  Further, since the cross-sectional shapes of the wires 50 shown below are all cross-sectional shapes along the axial direction W, the description of the cross-sectional direction is omitted.

  As shown in FIGS. 3 and 4, in the coil pipe 20, the element wire 50 is spirally wound along the axial direction W. In order to reduce the diameter of the coil pipe 20, the wire 50 has a diameter H substantially perpendicular to the axial direction W and along the radial direction K, for example, 0.3 mm or less.

  The wires 50 are configured such that the wires 50 adjacent to each other in the axial direction W can contact each other, and the contact portion 52 between the wires 50 is, for example, substantially perpendicular to the axial direction W and planar along the radial direction K. It has a shape formed into a shape.

  Further, each of the wires 50 after the winding has a cross-sectional shape having a curved surface portion 51 and a first connection portion 53.

  The curved surface portion 51 is located to be the inner peripheral surface 20n of the coil pipe 20, and has a radius of curvature R10.

  The first connecting portion 53 connects between the contact portion 52 and the curved surface portion 51, and has a curvature radius R11 (R10 ≠ R11) different from the curvature radius R10, and is formed in a curved surface shape.

  Note that the first connecting portion 53 is formed on the distal end side connecting portion 53a formed on the distal end side of each wound wire 50 and on the proximal end side in the axial direction W (hereinafter, simply referred to as the proximal end side). And the base end side connecting portion 53b.

  Next, the operation and effect of the present embodiment will be described.

  When one of the bending operation knobs 4 and 6 is operated and the wire 10 is pulled, the bending portion 2w is bent in any of up, down, left, and right directions. In actual use, the wire is pulled in a state where the coil pipe is bent, and a state as shown in FIG. 4 is obtained.

  At this time, as described above, the curved surface portion 51 of each wound wire 50 is located on the inner peripheral surface 20n of the coil pipe 20. For this reason, the contact area of the wire 50 with the wire 10 is smaller than that in a conventional configuration in which the cross section of the wire 50 has a shell-like shape and a flat portion is located on the inner peripheral surface 20n.

  Normally, the frictional force F is defined as friction coefficient μ × normal force N (F = μN), but when the contact area of the wire 50 with the wire 10 increases, the frictional force F naturally increases.

  Further, in a state where the coil pipe 20 is curved, the wire 10 tries to slide the shortest distance in the coil pipe 20, so that the wire 10 is strongly inserted into the inner peripheral surface 20 n of the curved coil pipe 20. It slides while contacting the inner peripheral surface 20n.

  Therefore, when the wire 10 is slid, the wire 10 made of metal and the inner peripheral surface 20n of the coil pipe 20 are shaved from each other. Large resistance when sliding.

  For this reason, in the present embodiment, since the curved surface portion 51 of the element wire 50 is located on the inner peripheral surface 20n, the wire 10 has a smaller diameter than the case where the flat portion is located on the inner peripheral surface 20n. , And the sliding resistance of the wire 10 in the coil pipe 20 is reduced. Therefore, since the amount of pulling operation force of the wire 10 becomes smaller than before, the bending operability of the operator can be improved.

  Furthermore, since the amount of scraping of the wire 10 and the coil pipe 20 is reduced as compared with the related art, the wear of the wire 10 and the coil pipe 20 is reduced, so that the durability of the wire 10 and the coil pipe 20 is improved, and the number of repairs is reduced. Reduction is possible.

  Further, when a compressive force P is applied to the coil pipe 20 along the axial direction W, a torsional moment M is generated in each of the wound wires 50 and a rotational force is applied, so that the contact portions 52 are provided. Then, the above-described pitch shift occurs.

  However, in the present embodiment, the strand 50 has a cross-sectional shape along the axial direction W in which the contact portions 52 of the strands 50 adjacent to each other in the axial direction W are formed in a planar shape. That is, the planes in the contact portion 52 are in contact with each other. As a result, the contact area between the wires 50 in the contact portion 52 becomes larger than in the related art in which the cross section of the wires 50 is formed in a circular or shell-like shape as described above.

  Therefore, the frictional force between the wires 50 in the contact portion 52 becomes larger than in the related art, and the wires 50 try to suppress the rotational force applied to the contact portion 52 from each other in terms of shape. Even if the torsional moment M is applied to 52, a pitch shift hardly occurs.

  Further, if the cross-sectional shape connects the curved surface portion 51 and the contact portion 52 formed in a flat shape, a corner portion is usually generated at the connection portion, and the wire 10 that slides while biting into the inner peripheral surface 20n is formed. There is a possibility that the slidability may be reduced by being caught on a corner.

  However, in the present embodiment, the element wire 50 has a cross-sectional shape including the first connecting portion 53 having a curved shape between the curved surface portion 51 and the contact portion 52. As a result, since no corner is generated, smooth sliding of the wire 10 can be realized.

  Furthermore, when the coil pipe 20 is bent, the corners described above do not contact each other, so that the coil pipe 20 can be bent easily and with a large bending angle.

  Further, in the cross-sectional shape of the above-described wire 50 in the present embodiment, as compared with the conventional circular cross-sectional shape, the wire 50 is crushed in the radial direction K, as shown in FIG. The size in the direction K decreases (Ka <Kb).

  For this reason, the outer diameter of the coil pipe 20 can be reduced. Therefore, the filling rate of the built-in component of the flexible tube 2k provided with the coil pipe 20 can be reduced.

  Here, when the bending portion 2w is bent, the built-in components move in the axial direction W in the flexible tube 2k. At this time, if the filling rate in the flexible tube 2k is low, the built-in components are not connected to each other. Since there is little contact and the built-in object can move smoothly, the bending operation is not hindered.

  Furthermore, since the outer diameter of the coil pipe 20 can be reduced, an extra space is generated in the flexible tube 2k, so that a new function can be mounted in the space.

  Further, as shown in FIG. 5, when the wire 50 is crushed in the radial direction K so that the outer diameter of the coil pipe 20 becomes smaller, the wire 50 becomes longer in the axial direction W than before (Na> Nb).

  For this reason, the number of turns of the strand 50 can be reduced. Therefore, the contact area of the wire 10 with each of the wound wires 50 can be reduced as compared with the related art, so that the sliding resistance of the wire 10 can be reduced.

  As described above, even if the compressive force P is applied to the coil pipe 20 in the axial direction W, it is possible to provide the endoscope 1 having a configuration in which the pitch is not easily shifted in the contact portion 52 between the strands 50. .

  Hereinafter, a modified example will be described with reference to FIG. FIG. 6 is a partial cross-sectional view along the axial direction of a coil pipe showing a modification example in which the radius of curvature of the distal-side connecting portion and the proximal-side connecting portion is different from each other in the first connecting portion of FIG.

  In the present embodiment described above, the first connecting portion 53 is formed to have a curvature radius R11 different from the curvature radius R10 of the curved surface portion 51.

  In addition, as shown in FIG. 6, the first connecting portion 53 may be formed such that the radius of curvature R1 of the distal side connecting portion 53a is larger than the radius of curvature R2 of the proximal side connecting portion 53b ( R1> R2).

  According to this, when pulling the wire 10 when bending the bending portion 2w, that is, when pulling the wire 10 from the front end of the coil pipe 20 into the coil pipe 20 from the front N1 to the rear N2, 10 can be more effectively prevented from being caught on the distal end side connection portion 53a than in the above-described embodiment.

  That is, the slidability of the wire 10 can be improved as compared with the above-described embodiment. The other effects are the same as those of the above-described embodiment.

(2nd Embodiment)

  FIG. 7 is a partial cross-sectional view along the axial direction of a coil pipe and a wire provided in an insertion portion of the endoscope according to the present embodiment.

  The configuration of the endoscope according to the second embodiment is different from that of the endoscope according to the first embodiment shown in FIGS. Is formed in a planar shape. Therefore, only this difference will be described, the same components as those in the first embodiment will be denoted by the same reference numerals, and description thereof will be omitted.

  Each wound wire 50 of the coil pipe 20 in the endoscope of the present embodiment shown in FIG. 7 has a flat surface along the axial direction W at a position positioned to be the outer peripheral surface 20 g of the coil pipe 20. It has a cross-sectional shape having a portion 54.

  The strand 50 has a cross-sectional shape along the axial direction W having a second connecting portion 55 formed in a curved shape, while connecting the flat portion 54 and the contact portion 52.

  The other configuration is the same as that of the first embodiment.

  According to such a configuration, since the flat portion 54 is formed on the outer peripheral surface 20g, the height of the strand 50 in the radial direction K can be reduced as compared with the first embodiment (Kc < Ka).

  Therefore, since the filling rate in the flexible tube 2k is reduced, the built-in components of the flexible tube are smoothly advanced and retracted, and the contact between the built-in components is reduced, so that the bending operation is hindered. There is no. Furthermore, since the contact between the coil pipe 20 and the built-in component is reduced, the durability of these members can be improved.

  Furthermore, since the second connecting portion 55 eliminates corners on the outer peripheral surface 20g side, the contact between the coil pipe 20 and other built-in components can be further reduced, so that the durability of these members is improved. Can be.

  Furthermore, since the outer diameter of the coil pipe 20 can be reduced, an extra space is generated in the flexible tube 2k, so that a new function can be mounted in the space.

  Further, when the coil pipe 20 is bent, the corners described above do not contact each other, so that the coil pipe 20 can be bent easily and with a large bending angle.

  Other effects are the same as those of the first embodiment.

  In the first and second embodiments described above, the surface roughness of the contact portion 52 may be formed larger than the surface roughness of the curved surface portion 51.

  According to this, in the curved surface portion 51, the resistance to the wire 10 is reduced, so that not only the slidability of the wire 10 is improved, but also in the contact portion 52, the friction between the wires is increased, and the pitch shift is smaller. Less likely to occur.

  The other effects are the same as those in the first and second embodiments.

  Further, in the above-described first and second embodiments, the contact portion 52 has been described as being formed in a plane substantially orthogonal to the axial direction W and along the radial direction K, but is not limited thereto. However, as long as it is formed in a planar shape, it goes without saying that it may be formed along a direction other than the direction substantially perpendicular to the axial direction W.

  Further, in the above-described first and second embodiments, the insertion device has been described by taking the endoscope 1 as an example. However, the insertion device is not limited to this, and for example, a manipulator or the like that can be inserted into a channel of the endoscope. Needless to say, the present invention is also applicable to a treatment tool or the like having a coil pipe and a wire in a flexible tube, and a gripping portion is operated by pulling the wire.

1. Endoscope (insertion device)
2 ... insertion part 10 ... wire (traction member)
Reference Signs List 20: coil pipe 20g: outer peripheral surface 20n: inner peripheral surface 50: strand 51: curved surface portion 52: contact portion 53: first connecting portion 53a: distal side connecting portion 53b: base side connecting portion 54: flat portion 55: Second connecting portion W: axial direction R1: radius of curvature of distal side connecting portion R2: radius of curvature of base side connecting portion R10: radius of curvature of curved surface portion R11: radius of curvature of first connecting portion

Claims (6)

An insertion portion to be inserted into the subject;
A traction member disposed in the insertion portion,
A coil pipe which is formed by being wound in a wire while being arranged in the insertion portion, and into which the traction member is inserted,
With
The cross section of the element wire along the axial direction of the coil pipe has a contact portion where the element wires adjacent in the axial direction contact each other, and all of the contact portions are formed in a planar shape. An insertion device characterized by the above-mentioned. The cross section of the strand is
A curved surface portion located on the inner peripheral surface of the coil pipe;
A first connecting portion that connects between the contact portion and the curved surface portion and has a curvature radius different from the curvature radius of the curved surface portion and is formed into a curved surface;
The insertion device according to claim 1, comprising: The first connecting portion includes:
A distal-side connecting portion formed on the distal side of the insertion portion in the cross section of the strand;
A base-side connecting portion formed on the base side of the insertion portion in the cross section of the strand;
Has,
The insertion device according to claim 2, wherein a radius of curvature of the distal-side connecting portion is larger than a radius of curvature of the proximal-side connecting portion.   2. The insertion device according to claim 1, wherein the cross section of the element wire has a flat portion located on an outer peripheral surface of the coil pipe and along the axial direction. 3.   The insertion device according to claim 4, wherein the cross section of the element wire connects the contact portion and the flat portion and has a second connection portion formed in a curved shape.   The insertion device according to claim 2, wherein the surface roughness of the contact portion is formed to be larger than the surface roughness of the curved surface portion.

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