Method for manufacturing curved tube, curved tube, and insertion apparatus

Abstract

This method for manufacturing a curved tube includes: forming a developed shape of a plurality of nodal rings connected by a plurality of joint parts from a sheet material; press-forming a plurality of first nodal rings having a first diameter and a plurality of second nodal rings having a second diameter different from the first diameter around a longitudinal axis; bending a part of the sheet material to form a butting part for one of the first nodal ring and the second nodal ring such that the butting part abuts against an end face of the other one of the first nodal ring and the second nodal ring, the end face being substantially perpendicular to the longitudinal axis of the other one of the first nodal ring and the second nodal ring; and joining the butting part to the end face of the other one of the first nodal ring and the second nodal ring.

Description

Bent pipe manufacturing method, bent pipe, and insertion device

[0001] The present invention relates to a method for manufacturing a bending tube to be provided in a bending portion of an insertion instrument such as an endoscope, and to a bending tube.

[0002] In general, an endoscope, which is an insertion instrument, has a long, thin insertion section that is inserted into a body cavity. This insertion section is connected to an operating section on the base end side. The insertion section has a tip section, a bending section, and a flexible tube section. The tip section is composed of a tip rigid section (tip component). The tip section is connected to the tip of the bending section. The bending section is connected to the tip of the flexible tube section. The bending section is bent to change the direction of the tip section. The flexible tube section is a long, thin, flexible tube body.

[0003] The bending section of the insertion section has a bending tube, a braid made of a metal mesh tube or the like covering the bending tube, and an outer cover covering the exterior side of the braid. The outer cover is a tube body made of a rubber material or the like that covers the outer circumferential surface of the bending tube. The bending tube has multiple node rings. The multiple node rings are arranged side by side in the longitudinal direction of the bending section. Adjacent node rings are connected to each other so that they can rotate freely.

[0004] The configuration and manufacturing method of the bending tube provided in such a bending portion are disclosed, for example, in Japanese Patent Application Laid-Open No. 2010-252859, Japanese Patent Application Laid-Open No. 2007-159636, or International Publication No. WO2016 / 190011.

[0005] Japanese Patent Application Publication Nos. 2010-252859 and 2007-159636 disclose techniques for manufacturing bending tubes used in endoscopes by pressing. International Publication WO2016 / 190011 discloses a configuration in which a portion of the shape of a bending tube used in an endoscope is processed by pressing, and bending operation wires or bending operation wire attachments are welded to the bending tube node rings.

[0006] Patent Document 2: Publication No. 2010-252859 Patent Document 2: Publication No. 2007-159636 International Publication WO2016 / 190011

[0007] However, in the conventional bending tube, pressed sheet material is stacked and multiple adjacent nodal rings with the same diameter are joined together. However, when a bending tube is manufactured from pressed sheet material, it is difficult to integrally join two nodal rings with different diameters.

[0008] Therefore, when using conventional techniques or combinations of these techniques to manufacture a bending tube having a node ring with a variable diameter, there is a problem that the cost is high. That is, a bending tube manufactured from a pressed sheet material is subject to molding restrictions on the diameter change of the node ring. Therefore, there is a problem that a bending tube manufactured from a pressed sheet material cannot have a desired diameter change such as a diameter expansion structure.

[0009] As a result, bending tubes manufactured by conventional press processing had the problem that it was not easy to form bending sections with varying diameters to eliminate the increased burden on the patient and the impact on insertion into the subject and observation.

[0010] The present invention has been made in consideration of the above circumstances, and aims to provide a method for manufacturing a bending tube for an endoscope having a variable diameter, thereby reducing costs and enabling inexpensive production, and a bending tube.

[0011] A method for manufacturing a bending tube to be attached to an insertion instrument according to one aspect of the present invention includes: forming, from a sheet material, an expanded shape of a plurality of nodal rings, each of which is connected by a plurality of joints; forming, by press working, a plurality of first nodal rings having a first diameter about a longitudinal axis and a plurality of second nodal rings having a second diameter different from the first diameter from the sheet material in which the expanded shapes of the plurality of nodal rings have been formed; forming, for at least one of the first nodal rings or the second nodal rings, at least one abutting portion that abuts against an end face of the other first nodal ring or the second nodal ring that is substantially perpendicular to the longitudinal axis, by bending a part of the sheet material in a direction intersecting the longitudinal axis; and joining the at least one abutting portion formed on one of the first nodal rings or the second nodal rings to the end face of the other of the first nodal rings or the second nodal rings.

[0012] A bending tube according to one aspect of the present invention is a bending tube attached to an insertion instrument, and has bending components including: a first node ring having a first diameter about a longitudinal axis formed by pressing a sheet material made of a metal plate; a second node ring having a second diameter about the longitudinal axis different from the first diameter formed by pressing the sheet material; an abutment portion formed integrally by bending at least one of the first node ring or the second node ring, the abutment portion abutting against a surface of an end portion in the longitudinal axis direction of the other of the first node ring or the second node ring; and a joint portion joining the abutment portion to the surface of the end portion in the longitudinal axis direction.

[0013] An insertion device according to one aspect of the present invention includes: an insertion section to be inserted into a subject; a bending tube attached to the distal end side of the insertion section having a plurality of nodal rings, the nodal rings being formed by pressing a sheet material made of a metal plate and having a first diameter about a longitudinal axis; a second nodal ring being formed by pressing the sheet material and having a second diameter about the longitudinal axis that is different from the first diameter; and a bending tube attached to the distal end side of the insertion section having a plurality of nodal rings, the nodal rings being formed integrally by bending at least one of the first nodal ring or the second nodal ring, the nodal ring abutting against a surface of an end portion in the longitudinal axis direction of the other first nodal ring or the second nodal ring, and a joint joining the abutting portion to the surface of the end portion in the longitudinal axis direction.

[0014] According to the present invention, the manufacturing method of a bent tube having a variable diameter can be simplified, thereby reducing costs and enabling inexpensive manufacture.

[0015] Figure showing the configuration of the endoscope, Cross-sectional view showing the tip and the configuration of the bending section of the insertion section, Planar view showing the processed sheet after multiple processing stages, Planar view showing the first press-processed sheet, Planar view showing the second press-processed sheet, Planar view showing the bending tube processed sheet, Cross-sectional view showing the press process of expanding the burring section by a press jig, Cross-sectional view showing the joint section, Planar view showing the bending tube processed sheet in a state where both sides of each joint ring preparation are separated from the carrier, Figure showing the state where each joint ring is bent, Planar view showing the bending tube processed sheet in a state where each joint ring is bent, Figure showing the state where the fitting part between the first joint end and the second joint end of each bent joint ring is spot-welded, Figure showing the state before the first joint ring group and the second joint ring group are joined, Figure showing the state where the first joint ring group and the second joint ring group are joined, Perspective view partially showing the state where the first joint welding part and the second joint welding part are fitted, Partial cross-sectional view showing the state where the first joint welding part and the second joint welding part are fitted and laser-welded, Partial cross-sectional view showing the dimensional relationship between the first joint welding part and the second joint welding part, Planar view partially showing the dimensional relationship between the first joint welding part and the second joint welding part, Partial cross-sectional view showing the joint part between the first joint ring group and the second joint ring group, Partial cross-sectional view showing the state where the end face on the proximal end side of the second joint welding part abuts against the end face on the distal end side of the first intermediate joint ring when the bending section is maximally bent, Figure showing the form in which four bending operation wires are fixed to the most distal joint ring according to the first modification example, Figure showing the form in which two bending operation wires are fixed to the most distal joint ring according to the first modification example, Perspective view partially showing the joint form of the first joint welding part and the second joint welding part as viewed from the upper side of the tip according to the second modification example, Perspective view partially showing the joint form of the first joint welding part and the second joint welding part as viewed from the upper side of the proximal end according to the second modification example, Perspective view partially showing the state of another joint form different from FIGS. 23 and 24 of the first joint welding part and the second joint welding part as viewed from the upper side of the tip according to the second modification example, Perspective view partially showing the state of another joint form different from FIGS. 23 and 24 of the first joint welding part and the second joint welding part as viewed from the upper side of the proximal end according to the second modification example, Perspective view partially showing the state of another joint form different from FIG. 26 of the first joint welding part and the second joint welding part as viewed from the upper side of the proximal end according to the second modification example, Cross-sectional view showing the form provided with a stepped pin for joining the left and right of the first joint ring and the second joint ring according to the first reference example, According to the first reference example,1 is a cross-sectional view showing a configuration in which pins are provided to join the left and right sides of the first and second joint node rings; 2 is a perspective view showing a state in which the recess formed on the top of the first joint welded portion is viewed from above the tip, according to the second reference example; 3 is a partial cross-sectional view showing a configuration in which the first and second joint node rings are surface-joined by recesses formed above and below the first and second joint node rings, according to the second reference example; 4 is a perspective view showing a state in which the recess formed on the side of the first joint welded portion is viewed from above the tip, according to the second reference example; a partial cross-sectional view showing a form in which the joint portion is surface-bonded by the wire guide; a partial cross-sectional view showing a bending tube in a state in which the joint portion is integrally formed with the wire guide and is bent at a predetermined angle; a partial cross-sectional view showing a configuration of the wire guide integrally formed with the joint portion; a partial cross-sectional view showing a curvature configuration of the inner circumferential surface on the base end side of the wire guide; a partial cross-sectional view showing a curvature configuration of the inner circumferential surfaces on the distal end side and the base end side of the wire guide; a fourth reference example; and a diagram showing a configuration of a recess that deforms the hole portion of the convex portion of each node ring that constitutes the joint portion;

[0016] (Embodiments) The following description will use an endoscope as an example of an insertion device according to the present embodiment. In the following description, the drawings based on each embodiment are schematic. It should be noted that the thickness-width relationships and thickness ratios of the various components of the endoscope may differ from the actual ones. Furthermore, the dimensional relationships and ratios of the various components of the endoscope may differ between the drawings.

[0017] First, we will explain the general configuration of an endoscope 1, which is an insertion instrument. The endoscope 1 here has a configuration that can be applied to various endoscopes such as upper gastrointestinal endoscopes, lower gastrointestinal endoscopes, bronchoscopes, nephropelvic and ureteral endoscopes, and duodenoscopes.

[0018] Furthermore, the endoscope 1, which is an insertion device, may be a single-use type in which all or at least a part of the components of the endoscope are disposed of after use, or a reusable type in which the endoscope is reprocessed and reused after use.

[0019] 1, an endoscope 1 according to the present embodiment is an insertion device having an insertion section 2, an operation section 3, and a universal cable 4. The insertion section 2 is a long, slender member that is inserted into a subject. The universal cable 4 is a composite cable. The insertion section 2 has, in order from the tip, a tip section 6, a bending section 7, and a flexible tube section 8.

[0020] The operation unit 3 is provided with a rotatable bending operation knob 14 for bending the bending portion 7 of the insertion unit 2. The operation unit 3 also has an air / water supply button 15, a suction button 16, a treatment instrument elevator operation lever 17, and the like.

[0021] The bending operation knob 14 is arranged so that two substantially disk-shaped rotating knobs, the UD bending operation knob 12 and the RL bending operation knob 13, overlap each other. The UD bending operation knob 12 is an operation member for bending the bending portion 7 in the up and down direction. The RL bending operation knob 13 is an operation member for bending the bending portion 7 in the left and right direction.

[0022] The operation section 3 has a gripping section 11 and a treatment tool insertion channel insertion section 18. The gripping section 11 is a portion that is gripped by the user.

[0023] The treatment tool insertion channel insertion portion 18 is disposed in the grip portion 11. This treatment tool insertion channel insertion portion 18 serves as an opening for inserting various treatment tools into the treatment tool insertion channel provided in the insertion portion 2. A forceps plug is provided in this treatment tool insertion channel insertion portion 18.

[0024] The universal cable 4 extends from the operation unit 3. An endoscope connector 20 that can be attached to and detached from a light source device (not shown) is provided at the extending end of the universal cable 4. A coiled cable (not shown here) is connected to the endoscope connector 20, and an electric connector that can be attached to and detached from a video processor (not shown) is provided at the extending end of this coil cable. Note that the shape of the connector 20 may be various shapes other than those shown in the drawings, as needed.

[0025] In the endoscope 1 of this embodiment, illumination light is transmitted from a light source device (not shown) to the tip 6 via a light guide bundle (not shown) of illumination means that is inserted through the insertion section 2, the operation section 3, and the universal cable 4.

[0026] Next, a detailed description will be given below of the bending section 7, which is a tubular section that constitutes part of the insertion section 2 of the endoscope 1. The bending section 7 has a bending part as a skeletal part at the bending portion.

[0027] 2, the insertion section 2 has a distal end of a bending tube 30 made up of a plurality of nodal rings connected to a distal end configuration section 21, which is a substantially cylindrical distal end hard member built into the distal end section 6. The bending tube 30 is made up of a plurality of nodal rings 31, 32, 33, 34, 35, and 36 as bending pieces that form a substantially circular ring shape and are connected to each other along a longitudinal axis X, which is the central axis of the insertion section 2 in a linear state.

[0028] Specifically, the bending tube 30 has, connected in order from the distal end along the longitudinal axis X, a most distal node ring 31, a first joint node ring 32, a second joint node ring 33, a plurality of first intermediate node rings 34, a plurality of second intermediate node rings 35 which are connected alternately, and a most proximal node ring 36.

[0029] These multiple node rings 31, 32, 33, 34, 35, and 36 are rotatably connected by a joint 37 serving as a pivotal support. The most distal node ring 31 is connected to the distal end constituent part 21 of the distal end portion 6. The most proximal node ring 36 is connected to a tube body such as a helical tube (not shown) provided inside the flexible tube section 8.

[0030] The bending tube 30 is covered with a bending rubber 40, which is an outer skin. A braid (not shown), such as a braided metal tube, is provided on the inner periphery of the bending rubber 40. The tip portion of the bending rubber 40 is fixed to the outer periphery of the tip constituent part 21 by a bobbin adhesive (not shown) or the like.

[0031] A plurality of long components are disposed as built-in components inside the insertion section 2. Specifically, four bending operation wires 44, which are long members for bending the bending section 7, are inserted into the insertion section 2.

[0032] In addition, long members such as a light guide bundle, an imaging cable, and various channels (none of which are shown) are inserted into the insertion portion 2. These long members are inserted from the insertion portion 2 to the operation portion.

[0033] The distal end portions of the four bending operation wires 44 are fixed to the wire retaining members 41 of the distal end configuration section 21. The four bending operation wires 44 rotate the bending tube 30 around the respective joints 37 by pulling and loosening operations. As a result, the bending section 7 is bent up, down, left, and right on the observation screen.

[0034] That is, the bending tube 30 is provided with a plurality of joints 37 arranged alternately to bend the bending tube 30 in a direction including the up-down direction, which is a first directional component perpendicular to the longitudinal axis X, and a plurality of joints 37 to bend the bending tube 30 in a direction including the left-right direction, which is a second directional component perpendicular to the longitudinal axis X.

[0035] Note that a plurality of wire guides 42, 43 serving as wire receivers through which the bending operation wire 44 is inserted are joined to the inner circumferential surface of each of the node rings 32, 33, 35, 36 except for the most distal node ring 31 and each of the first intermediate node rings 34. The plurality of wire guides 42, 43 are guide members that guide the bending operation wire 44, which is an elongated member.

[0036] Hereinafter, a description will be given of a manufacturing method of the bending tube 30 disposed in the bending section 7. The bending tube 30 of this embodiment is mass-produced by automatic press processing using a dedicated press machine and press feed device.

[0037] Specifically, the bending tube 30 is manufactured through a sheet manufacturing process using progressive press working, a stacking process using transfer working, an outer shape cutting process, and a bending process.

[0038] As shown in Fig. 3, sheet manufacturing processing involves a press machine (not shown) that processes a coil of metal sheet material, such as stainless steel, with a thickness of 0.2 mm to 1.0 mm. In this sheet manufacturing processing, the sheet material undergoes multiple processing stages to produce a processed sheet 100. The multiple processing stages include positioning using a pilot, piercing, pilot hole punching, coining, burring, cutting (1, 2), face pressing and backing, hole trimming, stepped bending, and side cutting.

[0039] The processed sheet 100 manufactured in this manner is separated into two sheets, a first pressed sheet 101 shown in Fig. 4 and a second pressed sheet 102 shown in Fig. 5, by the final cutting step of the progressive press working. In other words, the first pressed sheet 101 and the second pressed sheet 102 are simultaneously produced from the same metal coil material.

[0040] 4, a plurality of nodal ring preparatory bodies 32a, 33a, 35a, etc. are formed on the first press-processed sheet 101. The plurality of nodal ring preparatory bodies 32a, 33a, 35a each have an arc-shaped first convex portion 37a that serves as a pivot mechanism for the joint portion 37.

[0041] A plurality of pilot holes 105 and a plurality of outline punches 106 are formed in the first press-processed sheet 101. Each pilot hole 105 is formed by punching or the like in a carrier 104 that serves as a feed rail for the first press-processed sheet 101. Each pilot hole 105 is a hole into which a pilot pin (not shown) that determines the press position of the first press-processed sheet 101 is inserted.

[0042] Each of the outer shape punches 106 is a portion where metal coil material has been punched out using a die (not shown) to match the outer shapes of a plurality of joint ring preparation bodies, such as the first joint ring preparation body 32a, the second joint ring preparation body 33a, and the (second) intermediate joint ring preparation body 35a.

[0043] The first joint node ring preparatory body 32a is a base material that will become the first joint node ring 32. A pair of first joint welds 45 is formed on the first joint node ring preparatory body 32a in the up-down direction along which the bending section 7 is bent. Each of the first joint welds 45 is formed so as to protrude from one edge of the first joint node ring preparatory body 32a (facing a second joint node ring preparatory body 33a, which will be described later) toward the base end.

[0044] A recess 46 is formed in the center of each of the first joint welds 45. That is, each of the first joint welds 45 has a U-shape that protrudes toward the base end.

[0045] The second joint node ring preparatory body 33a is a base material that will become the second joint node ring 33. The second joint node ring preparatory body 33a has a pair of second joint welds 47 formed in the up-down direction along which the bending section 7 is bent. Each second joint weld 47 is formed so as to protrude toward the base end from an edge of the second joint node ring preparatory body 33a that faces the second intermediate node ring preparatory body 35a.

[0046] Each second joint weld 47 is sized and shaped to fit into the recess 46 of the first joint weld 45. Each second joint weld 47 becomes a bent portion that is bent at a substantially right angle (≈90°) in the outer diameter direction of the second joint node ring 33 by a bending process described below. The (second) intermediate node ring preparation 35a is a base material that becomes the second intermediate node ring 35.

[0047] As shown in FIG. 5, a plurality of node ring preparatory bodies 31a, 34a, 36a, etc. are formed on the second press-processed sheet 102.

[0048] The plurality of nodal ring preparatory bodies 31 a, 34 a, 36 a each have an arc-shaped second convex portion 37 b that serves as a pivot mechanism for the joint portion 37. The first joint nodal ring preparatory body 32 a and the second joint nodal ring preparatory body 33 a are connected by a bridge 107. The bridge 107 is an edge rail that serves as a connecting portion that will be separated later.

[0049] A plurality of pilot holes 109 and a plurality of outline punches 110 are also formed in the second press-processed sheet 102. Each pilot hole 109 is also formed by punching or the like in a carrier 108 which serves as a feed rail for the second press-processed sheet 102. Each pilot hole 109 is also a hole into which a pilot pin (not shown) which determines the press position of the second press-processed sheet 102 is inserted.

[0050] Each of the outer shape punches 110 is a portion where metal coil material has been punched out using a die (not shown) to match the outer shapes of a plurality of node ring preparatory bodies, such as the most distal node ring preparatory body 31 a, the first intermediate node ring preparatory body 34 a, and the most proximal node ring preparatory body 36 a.

[0051] The most distal node ring preliminary body 31a is a base material that will become the most distal node ring 31. The most distal node ring preliminary body 31a is connected to the carrier 108 by a bridge 111. The bridge 111 is also an edge beam that serves as a connecting part that will be separated later.

[0052] The first intermediate bending part preparatory body 34a is a base material that will become the first intermediate bending part 34. The most proximal bending part preparatory body 36a is a base material that will become the most proximal bending part 36. The most proximal bending part preparatory body 36a is also connected to the carrier 108 by a bridge 111 that serves as a connecting part that will be separated later.

[0053] Burrings 37c (see FIG. 7) are formed on each of the second protrusions 37b of the second press-processed sheet 102. The burrings 37c are annular portions that protrude from one surface by pressing the pilot holes of each second protrusion 37b in a predetermined direction (upward).

[0054] Next, the two second joint welds 47 of the second joint node ring 33 are bent by press working at a substantially right angle (90°) to the surface direction that becomes the outer diameter side of the bending tube 30. That is, the second joint welds 47 are formed by bending the convex portions extending from the ends of the second joint node ring 33 in a direction away from the longitudinal axis X.

[0055] The first press-processed sheet 101 and the second press-processed sheet 102 manufactured as described above are then superimposed on the second press-processed sheet 102, as shown in Fig. 6. In this manner, a curved pipe sheet 103 is manufactured. At this time, the burrings 37c of the second protrusions 37b of the second press-processed sheet 102 are inserted into the holes of the first protrusions 37a of the first press-processed sheet 101.

[0056] The first press-processed sheet 101 and the second press-processed sheet 102 are automatically transported by a press feed device during the overlapping process. Furthermore, the curved pipe processing sheet 103 is transported by a transfer device to various press processes such as a punching process and a bending process, and is pressed.

[0057] As shown in Fig. 7, the bending pipe processing sheet 103 is subjected to a pressing process in which the burrings 37c of each second protrusion 37b are opened onto the inserted first protrusion 37a by a press jig 120. In this way, each joint portion 37 shown in Fig. 8 is formed in the bending pipe processing sheet 103. As a result, each of the node ring preparatory bodies 31a, 32a, 33a, 34a, 35a, and 36a is connected.

[0058] 9, the bending pipe processing sheet 103 is separated by cutting both side portions of each of the nodal ring preparatory bodies 31a, 32a, 33a, 34a, 35a, and 36a from the carriers 104 and 108 by press working. At this time, a concave first joint end portion 38a and a convex second joint end portion 38b are cut out (notched) on both side portions of each of the nodal ring preparatory bodies 31a, 32a, 33a, 34a, 35a, and 36a.

[0059] In this way, base materials of the expanded shapes of the node rings 31, 32, 33, 34, 35, and 36 are formed on the bent tube processing sheet 103. Note that the bridge 107 connecting the first joint node ring 32 and the second joint node ring 33 and the bridge 111 connecting the most distal node ring 31 or the most proximal node ring 36 to the carrier 108 remain.

[0060] Each of the node rings 31, 32, 33, 34, 35, and 36 is bent (rounded) into a cylindrical surface with a curvature radius of approximately R6 so that each of the first joint ends 38a and each of the second joint ends 38b fit together, as shown in FIG. 10 .

[0061] The outer diameter (diameter) of each of the node rings 31, 32, 33, 34, 35, and 36 is set in accordance with the plate thickness (0.2 mm to 0.5 mm), for example, in the range from a small diameter of 6.0 mm to a large diameter of 13.0 mm.

[0062] 12, the bent node rings 31, 32, 33, 34, 35, and 36 are spot-welded SW by laser welding or the like at the fitted first joint ends 38a and second joint ends 38b. That is, the facing portions of the first joint ends 38a and second joint ends 38b are fitted together and spot-welded SW.

[0063] At this time, one end face of each of the first joint ends 38a and each of the second joint ends 38b serves as an abutment portion against which the other end faces of the first joint ring group 30a and the second joint ring group 30b abut. The end faces that serve as the abutment portions are aligned along the longitudinal axis X direction of the first joint ring group 30a and the second joint ring group 30b. The abutment portions are joined by spot welding SW. Note that the end faces against which the first joint ends 38a and each of the second joint ends 38b abut are flat surfaces in the thickness direction of the first joint ends 38a and each of the second joint ends 38b.

[0064] To improve assembly, each of the first and second joint ends 38a, 38b has an uneven shape with a seam q of 1 mm or less. Spot welding SW is performed at, for example, 3 to 7 locations for each joint between the first and second joint ends 38a, 38b.

[0065] In this way, the curved tube processing sheet 103 is formed with a first node ring group 30a in which the most distal node ring 31 and the first joint node ring 32 are connected by the joint portion 37, and a second node ring group 30b in which the second joint node ring 33, the plurality of intermediate node rings 34, 35, and the most proximal node ring 36 are connected by the joint portion 37.

[0066] The outer diameter d1 of the first joint node ring 32 of the first node ring group 30a is set to be larger than the outer diameter d2 of the second joint node ring 33 of the second node ring group 30b (d1>d2). That is, the first node ring group 30a constituting the large-diameter front joints and the second node ring group 30b constituting the small-diameter rear joints of the bending tube 30 are press-formed into the bending tube processing sheet 103 here.

[0067] The first and second nodal ring groups 30a and 30b are then cut away from the bent pipe processing sheet 103 and separated from each other. After that, although not shown, wire guides 42 and 43 are laser welded to the first and second nodal ring groups 30a and 30b from the outer periphery. Laser welding of the wire guides 42 and 43 may be performed simultaneously with laser spot welding SW of the joints of the first joint end portions 38a and the second joint end portions 38b. The wire guides 42 and 43 may also be fixed to the first and second nodal ring groups 30a and 30b by brazing, adhesive, or the like.

[0068] The first and second node ring groups 30a and 30b are assembled together after welding the wire guides 42 and 43. Specifically, as shown in Figures 13 and 14, the first joint node ring 32 of the first node ring group 30a and the second joint node ring 33 of the second node ring group 30b are joined together. The first joint node ring 32 is joined so that its base end portion covers the tip end portion of the second joint node ring 33.

[0069] 15 , an assembly jig (not shown) is used, and a pair of upper and lower second welds 47 are fitted into the recesses 46 of the pair of upper and lower first welds 45 in the bending direction of the bending section 7. Note that the second welds 47 have end faces 47a on the tip side bent at a substantially right angle (≈90°) in the outer diameter direction of the first joint node ring 32, which form abutting contact portions that come into contact with base end faces 46a that form the edges of the recesses 46 of the first welds 45. That is, each second weld 47 abuts against the surface of an end portion in the longitudinal axis direction of the first joint node ring 32.

[0070] Each second joint weld 47 of the abutting portion is provided at a position offset by a predetermined angle, here approximately 90°, around the longitudinal axis X, which serves as the central axis, with respect to the position of the joint portion 37 closest to the abutting first joint node ring 32. Furthermore, each second joint weld 47 is provided in the up-down direction, which is the largest angle side at which the bending portion 7 bends around the longitudinal axis X.

[0071] Then, each of the first joint welds 45 and each of the second joint welds 47 are joined by laser welding LW. At this time, each of the first joint welds 45 and each of the second joint welds 47 constitutes an abutting portion where a base end surface 46a and an end surface 47a, which are opposing surfaces at the longitudinal axis direction end portions of the first node ring group 30a or the second node ring group 30b, abut against each other. Each abutting portion is joined by laser welding LW. Note that the base end surface 46a and the end surface 47a are planes perpendicular to the longitudinal axis X of the bending tube 30 to which the first node ring group 30a and the second node ring group 30b are joined.

[0072] In this way, the bending tube 30 here has a structure in which the first joint node ring 32 of the first node ring group 30a and the second joint node ring 33 of the second node ring group 30b, which have different diameters, are joined by laser welding LW.

[0073] The first joint welds 45 and the second joint welds 47 may be joined together by spot welding SW, adhesive bonding, or the like.

[0074] Therefore, the first joint node ring 32 and the second joint node ring 33 are integrated into one node ring, thereby forming a bending tube 30 in which the first node ring group 30a with a large diameter on the distal end side and the second node ring group 30b with a small diameter on the proximal end side are joined together.

[0075] In addition, when the first joining weld 45 and the second joining weld 47 are laser welded LW, the second joining weld 47 fits into each of the recesses 46 of the two first joining welds 45 above and below in the bending direction of the curved portion 7.

[0076] Therefore, the left-right positions of the first joint node ring 32 and the second joint node ring 33 are restricted when the bending section 7 is bent. Furthermore, the first joint node ring 32 and the second joint node ring 33 are aligned with the longitudinal axis X, which is their respective central axes, by an assembly jig (not shown), and the up-down positions of the bending section 7 are restricted when the bending section 7 is bent.

[0077] 16 , laser welding LW is performed from the outer diameter side of the second joint weld 47 toward the ridge line of the recess 46 of the first joint weld 45 with which the second joint weld 47 is in contact, in a direction approximately perpendicular to the surface of the first joint weld 45. Note that the laser welding LW may also be performed from the back side of the second joint weld 47 in an oblique direction at a predetermined angle θ so as to penetrate the second joint weld 47. Note that the laser welding LW for joining the first joint weld 45 and the second joint weld 47 may be automated using a dedicated laser welding device.

[0078] In this way, as a method of joining the first joining node ring 32 and the second joining node ring 33, which have different diameters, joining by laser welding LW can suppress the reduction in the volume of the internal space of the curved tube 30 (compression of the internal contents) more than the crimping joining that is often used by press processing.

[0079] Here, the dimensional relationship between the first joint weld 45 of the first joint node ring 32 and the second joint weld 47 of the second joint node ring 33 will be described. First, as shown in Figures 17 and 18, the plate thickness T of the first joint node ring 32 and the second joint node ring 33 is set to, for example, 0.2 mm to 0.5 mm (T = 0.2 to 0.5). Also, the diameter dimension φ of the bending tube 30 ranges from a small diameter of 6 mm (φ = 6.0) to a large diameter of 13 mm (φ = 13.0).

[0080] 17, the gap b between the first joint node ring 32 and the second joint node ring 33 is, for example, 0.25 mm (b = 0.25 mm). The inner radius of curvature R of the second joint welded portion 47 bent at a substantially right angle (≈ 90°) toward the outer diameter of the second joint node ring 33 is, for example, 0.1 mm (R = 0.1 mm).

[0081] In this case, the rising height H of the second joint weld 47 is set to be equal to or greater than 2T+R (H≧2T+R), which is the sum of twice the plate thickness T of the first joint node ring 32 and the second joint node ring 33 and the radius of curvature R. If the plate thickness T of the first joint node ring 32 and the second joint node ring 33 is 0.3 mm (T=0.3), the rising height H of the second joint weld 47 is set to, for example, 0.75 mm (H=0.75 mm), which is equal to or greater than 0.70 mm.

[0082] Due to this dimensional relationship, the second joint-weld 47 has a height H that protrudes from the surface of the first joint-weld 45. If the height H of the second joint-weld 47 is 0.75 mm (H=0.75 mm), the protrusion amount h is 0.2 mm (h=0.2). The protrusion amount h is set in the range of 0 mm to 0.5 mm (0≦h≦0.5).

[0083] Even if the joining positions of the first joint node ring 32 and the second joint node ring 33 are displaced in the vertical direction, the protrusion amount h of the second joint weld 47 satisfies the dimensional condition that it is greater than the difference between the gap b between the first joint node ring 32 and the second joint node ring 33 minus the inner radius of curvature R of the second joint weld 47 (h>b-R). This ensures the welding area of ​​the second joint weld 47 to the first joint weld 45.

[0084] In this way, the second joint weld 47 is set to a height H that slightly protrudes radially outward from the first joint weld 45 to facilitate laser welding LW. If there is no protrusion, the second joint weld 47 will not have enough thickness for laser welding LW. Therefore, it is preferable that the second joint weld 47 protrudes beyond the surface position of the first joint weld 45 at the time of press forming.

[0085] Furthermore, since the edges of the second joint weld 47 are rounded during the laser welding LW, there is no risk of damaging the bending rubber 40 covering the bending tube 30. That is, the protruding height of the second joint weld 47 is reduced by the laser welding LW, and the cross section is rounded, reducing the risk of damaging the bending rubber 40.

[0086] 18 , the width W1 of the recess 46 of the first joint-welded portion 45 is, for example, 2.0 mm (W1 = 2.0). The widths W2 of both sides of the first joint-welded portion 45 sandwiching the recess 46 are the same, for example, 1.0 mm (W2 = 1.0). That is, the width W1 of the recess 46 formed in the first joint-welded portion 45 is twice the width W2 of the both sides (W1 = 2W2).

[0087] The depth t of the recess 46 formed in the first joint weld 45 is, for example, 0.25 mm when the plate thickness T of the second joint weld 47 is 0.3 mm (T = 0.3). That is, the depth t of the recess 46 is a dimension (T > t) that is 0.05 mm shorter than the plate thickness T (0.3 mm) of the mating second joint weld 47. As a result, the second joint weld 47 protrudes more toward the base end than the first joint weld 45.

[0088] For example, if the width W1 of the recess 46 of the first joint-weld portion 45 is 2.0 mm (W1 = 2.0), the range P of the laser welding LW joining the first joint-weld portion 45 and the second joint-weld portion 47 is set to about 1.4 mm (P ≈ 1.4). The conditions for the laser welding LW are set to an output of 400 to 800 watts (W) and a pulse width of 0.5 to 10 msec.

[0089] 19 and 20 , when the bending section 7 is bent to its maximum extent, the end surface 47b on the base end side reliably abuts against the end surface 34b on the tip side of the first intermediate node ring 34. This improves the accuracy of the bending function of the bending section 7.

[0090] In addition, as a manufacturing method for the above-mentioned bending tube 30, it is preferable to first join each wire guide 42, 43 to the first node ring group 30a and the second node ring group 30b by laser welding LW before joining the first node ring group 30a with a large diameter and the second node ring group 30b with a small diameter.

[0091] Then, after the wire guides 42, 43 are provided in the first and second nodal ring groups 30a, 30b, the first joint welds 45 and the second joint welds 47 are joined by laser welding LW. This is because if the first and second nodal ring groups 30a, 30b, which have different diameters, are laser welded LW first, there will be portions of the wire guide 42 that are difficult to join by laser welding LW.

[0092] In the above-described method, plate material is pressed to create pressed sheets 101 and 102, which are then stacked to form a curved pipe processed sheet 103. The curved pipe processed sheet 103 is then bent (rounded) while the nodal rings 31, 32, 33, 34, 35, and 36 are processed, and the joint ends are fitted together to form a cylindrical surface. In this method, if the first nodal ring group 30a and the second nodal ring group 30b are not connected to each other, it is possible to simultaneously generate the first nodal ring group 30a and the second nodal ring group 30b having different diameters.

[0093] However, in a nodal ring group (a nodal ring group in which a portion corresponding to the first nodal ring group 30a and a portion corresponding to the second nodal ring group 30b are connected in series), the diameter changes significantly midway. Therefore, it is extremely difficult to bend (round) such a nodal ring group so that the longitudinal axis X is common to the portion corresponding to the first nodal ring group 30a and the portion corresponding to the second nodal ring group 30b, and the joint ends of the nodal rings 31, 32, 33, 34, 35, and 36 are all fitted together.

[0094] Furthermore, it is also possible to press-form a node ring group whose diameter changes significantly midway through (a node ring group in which a portion corresponding to the first node ring group 30a and a portion corresponding to the second node ring group 30b are connected in series) in several small steps with multiple additional steps. However, in such a case, the number of processing steps increases significantly, which results in a significant increase in manufacturing costs.

[0095] Therefore, in the manufacturing method of the bending tube 30 of this embodiment, the first node ring group 30a and the second node ring group 30b, which have different diameters, are pressed (transfer processed), and then separated from the bending tube processing sheet 103, and the first node ring group 30a and the second node ring group 30b are joined together.

[0096] Furthermore, the spot welding SW that joins the first joint end 38a and the convex-shaped second joint end 38b of each of the node rings 31, 32, 33, 34, 35, and 36 can be performed by laser welding LW. Therefore, the spot welding SW can share a laser welding device with the laser welding LW that joins the first node ring group 30a and the second node ring group 30b, and the welding process can be unified.

[0097] In the manufacturing method of the curved tube 30 described above, taking into consideration mass production including costs, the two first press-processed sheets 101 and the second press-processed sheet 102, which are formed by pressing the expanded base materials of the multiple node rings 31, 32, 33, 34, 35, and 36, are manufactured from the same metal sheet material, that is, coil material.

[0098] The manufacturing method of the bending tube 30 involves overlapping the first press-processed sheet 101 and the second press-processed sheet 102, and pressing the joints 37 that rotatably connect the plurality of node rings 31, 32, 33, 34, 35, and 36 together.

[0099] Next, the manufacturing method of the bending tube 30 involves rolling the multiple nodal rings 31, 32, 33, 34, 35, and 36 by pressing, and forming a first group of nodal rings 30a and a second group of nodal rings 30b having different diameters into a first pressed sheet 101 and a second pressed sheet 102, which are sheet materials.

[0100] Thereafter, in a separate step in the manufacturing method of the bending tube 30, the first node ring group 30a and the second node ring group 30b having different diameters are joined together. Note that the bending tube 30 here has a structure in which the diameters of the first node ring group 30a having a large diameter and the second node ring group 30b having a small diameter are changed.

[0101] Furthermore, in order to enable the bending tube 30 to have joints 37 successively arranged in the same direction at short intervals and to bend significantly in the up-down direction near the tip, first joint welds 45 and second joint welds 47 are provided in the up-down direction at the connecting portions where the first joint node ring 32 and the second joint node ring 33, which are node rings of different diameters, are welded together.The bending tube 30 has an increased number of joints 37 on the left and right sides so that the bending angle in the up-down direction can be increased.

[0102] As described above, the bending tube 30 can be manufactured using a press process, which eliminates the molding constraints imposed by diameter expansion processes such as bulge forming, and the desired diameter expansion structure can be achieved by a single node ring formed by joining the first joint node ring 32 and the second joint node ring 33.

[0103] Conventionally, in order to manufacture a bending pipe 30 having a variable diameter by connecting a plurality of node rings, it is necessary to perform a diameter expansion process on the plurality of node rings by a difficult forming method such as bulge forming.

[0104] Due to molding constraints, bending pipes with varying diameters must have varying diameters for each of the multiple nodal rings. Therefore, bending pipes with varying diameters require more processing options and more steps. In other words, the manufacturing cost of a bending pipe with varying diameters increases depending on the number of processing steps.

[0105] Furthermore, it is difficult to manufacture a bending tube 30 with a variable diameter using conventional automatic press processing. In contrast, the bending tube 30 of this embodiment can be manufactured inexpensively by simplifying the manufacturing method using press processing and laser welding, thereby suppressing increases in manufacturing costs. As a result, the bending tube 30 of this embodiment can contribute to reducing manufacturing costs by being used in a single-use endoscope 1 for which low prices are desired.

[0106] Furthermore, the structure of the bending tube 30 of this embodiment has, for example, diameter changes of each of the node rings 31, 32, 33, 34, 35, and 36 compared to the conventional structure used in the existing endoscope 1. This is to make the bending section 7, in which the bending tube 30 is built, as thin as possible for the sake of insertability of the insertion section 2 of the endoscope 1.

[0107] However, the distal end 6 of the insertion portion 2 needs to be thick to a certain extent in order to accommodate the internal components. If the diameter of the bending portion 7 of the endoscope 1 is adjusted to match the diameter of the distal end 6 of the insertion portion 2, the bending portion 7 will have an unnecessarily thick diameter. This raises concerns about increased strain on the patient (subject) during the procedure and adverse effects on the insertability and observation capabilities of the insertion portion 2.

[0108] Furthermore, it is desirable that the insertion section 2 of the endoscope 1 have a small diameter to improve insertability into an examination object. Therefore, the bending tube 30 of this embodiment has a structure in which the first nodal ring group 30a on the tip side connected to the tip section 6 has a large diameter to match the diameter of the tip section 6, and the second nodal ring group 30b connected to the base end of this first nodal ring group 30a has a small diameter.

[0109] As a result, the bending tube 30 of this embodiment, by using a nodal ring structure with a variable diameter, can reduce the increase in burden on the patient and the impact on the insertability and observation properties of the insertion section 2 of the endoscope 1, which is an insertion device.

[0110] As explained above, the manufacturing method of the bending tube 30 and the structure of the bending tube 30 of this embodiment simplify the manufacturing method of the bending tube 30 of the endoscope 1, which is an insertion device having a variable diameter, thereby reducing costs and enabling inexpensive manufacturing. As a result, by using the bending tube 30 of this embodiment for the bending section 7 of the insertion section 2, the endoscope 1, which is an insertion device, has a configuration that eliminates increased burden on a subject such as a patient, and effects on insertability into the subject, observationability, etc.

[0111] 21 , the four bending operation wires 44 may be configured such that their respective distal ends are fixed by caulking or the like to four wire retaining members 41 joined to the most distal node ring 31 on the top, bottom, left, and right sides around the longitudinal axis X of the bending tube 30. That is, four bending operation wires 44 are provided here, and their respective distal ends are individually fixed to the wire retaining members 41. Note that the configuration for fixing the distal ends of the bending operation wires 44 to the most distal node ring 31 may be achieved by welding or brazing instead of by using the wire retaining members 41.

[0112] 22 , two bending operation wires 44 may be used, and inserted into the most-rearmost node ring 31 at the upper and right portions and the lower and left portions around the longitudinal axis X of the bending tube 30. Each bending operation wire 44 is disposed along the outer periphery of the most-rearmost node ring 31 from the upper portion to the right portion or from the lower portion to the left portion, and the portion where it is inserted into the most-rearmost node ring 31 is fixed by welding or brazing.

[0113] (Second Modification) As shown in FIGS. 23 and 24 , the joining structure of the first joint ring group 30 a and the second joint ring group 30 b, which are different diameter joint ring groups, may be configured such that a convex first joint weld 45 a protruding from the end on the base end side of the first joint joint ring 32 fits into grooves 48 of two second joint welds 47 bent in the outer diameter direction from the end on the tip end side of the second joint joint ring 33, and the two joint welds are joined by laser welding LW.

[0114] Furthermore, the joining structure of the first and second joint ring groups 30a and 30b, which are different diameter joint ring groups, may be configured such that the first joint weld 45a is fitted into a hole 48a or an elongated hole 48b formed in one second joint weld 47 bent radially outward from the tip end of the second joint ring 33, and joined by laser welding LW, as shown in FIGS. 25 to 27 .

[0115] The first joint-welded portion 45a and the second joint-welded portion 47 may be joined by spot welding SW, adhesive bonding, or the like, in addition to laser welding LW.

[0116] (First Reference Example) As a method of joining the first joint node ring 32 and the second joint node ring 33 of the different diameter joint rings, in addition to laser welding LW of the first joint welded portion 45 and the second joint welded portion 47, they may be joined in the left-right direction by a stepped pin 51 as shown in Fig. 28. Note that the stepped pin 51 is joined by laser welding LW, spot welding SW, adhesive bonding, or the like, just like the first joint welded portion 45 and the second joint welded portion 47.

[0117] As a method of joining the first joint node ring 32 and the second joint node ring 33 of the different diameter joint rings, in addition to laser welding LW between the first joint welded portion 45 and the second joint welded portion 47, they may be joined in the left-right direction by a pin 52 as shown in Fig. 29. Here, the pin 52 is also joined by laser welding LW, spot welding SW, adhesive bonding, or the like, just like the first joint welded portion 45 and the second joint welded portion 47.

[0118] In this way, by adding stepped pins 51 or pins 52 in the left-right direction to the first joint node ring 32 and the second joint node ring 33 of the different diameter node rings, the joining strength by laser welding LW of the first joint weld portion 45 and the second joint weld portion 47 can be reinforced.

[0119] In this way, the joining of the first joint node ring 32 and the second joint node ring 33 using the stepped pin 51 or pin 52 can be performed from the outer circumferential direction by approaches such as laser welding (LW), spot welding (SW), and adhesive bonding. This reduces processing constraints and design constraints on the interior of the bending pipe 30. Furthermore, the joining method of the first joint node ring 32 and the second joint node ring 33 of different diameters may be a welding joint using half punches (not shown).

[0120] Second Reference Example As a method of joining the first joint node ring 32 and the second joint node ring 33 of the different diameter joint rings, a mode in which the first joint welded portion 45 and the second joint welded portion 47 are not provided may be adopted.

[0121] Specifically, as shown in Figures 30 and 31, first recesses 55 that partially protrude inward in the radial direction are formed above and below the first joint node ring 32 with a large diameter, and second recesses 56 that partially protrude outward in the radial direction are formed above and below the second joint node ring 33 with a small diameter.

[0122] Then, the surface of the first joint node ring 32 that protrudes inward due to the first recess 55 and the surface of the second joint node ring 33 that protrudes outward due to the second recess 56 are brought into contact with each other, and the first joint node ring 32 and the second joint node ring 33 are joined by laser welding LW, spot welding SW, adhesive bonding, or the like.

[0123] Furthermore, as shown in Figures 32 and 33, third recesses 57 that partially protrude inward in the radial direction may be formed on the left and right sides of the large-diameter first joint node ring 32, and fourth recesses 58 that partially protrude outward in the radial direction may be formed on the left and right sides of the small-diameter second joint node ring 33, and the protruding surfaces of the third recesses 57 and the fourth recesses 58 may be brought into contact with each other, and the first joint node ring 32 and the second joint node ring 33 may be joined by laser welding LW, spot welding SW, adhesive bonding, or the like.

[0124] The second reference example shows an example in which pairs of recesses 55, 56 are formed on the top and bottom of the first and second joint node rings 32, 33. However, depending on the difference in outer diameter between the first and second joint node rings 32, 33, only one of the recesses 55 or 56 may be formed. Similarly, the second reference example shows an example in which pairs of recesses 57, 58 are formed on the left and right of the first and second joint node rings 32, 33. However, depending on the difference in outer diameter between the first and second joint node rings 32, 33, only one of the recesses 57 or 58 may be formed. The recesses 55, 56, 57, 58 are formed by half-blanking, dowel processing, or the like during the press process.

[0125] (Third Reference Example) The endoscope 1, which is an insertion device, is provided with a wire guide 42, which is a pipe-shaped wire receiver brazed to the inner surface of the rear end of each node ring. In this configuration, when the curved shape of the bending operation wire 44 matches the curved state of each node ring 31, 32, 33, 34, 35, and 36, the trajectory of the central axis of the bending operation wire 44 and the trajectory of the central axis of the wire guide 42 do not match. Therefore, the bending operation wire 44 rubs against the wire guide 42, particularly the rear end portion, increasing the amount of bending force.

[0126] When the rear end of the wire guide 42 is processed, a distinction is made between the front and rear, which reduces manufacturability. For example, if the rear end of the wire guide 42 is made thinner to prevent the wire from getting caught, the brazing material will flow onto the inner surface of the wire guide during brazing, which reduces manufacturability.

[0127] Furthermore, if the rear end of the wire guide 42 is made thinner, the gap between the bending operation wire 44 and the wire guide 42 becomes larger in some parts, and the bending operation wire 44 reduces the pressure on the wire guide 42, causing the node rings 31, 32, 33, 34, 35, and 36 to rattle relative to each other.

[0128] Therefore, as shown in FIGS. 34 and 35, the bending tube 30 here is formed integrally with the rivets 61 that rotatably connect the node rings 34, 35 (31, 32, 33, 36) and the wire guides 62 that receive the wires.

[0129] The wire guide 62 is formed so that the inner diameter h2 at the front and rear ends of the inner surface is larger than the inner diameter h1 at the center. That is, the wire guide 62 is formed so that the ridge line of the inner surface describes an arc in a cross section passing through the central axis Z. Furthermore, this arc is set smaller than the radius of curvature of the bending portion 7 (≈ the radius of curvature of the bending operation wire 44).

[0130] The wire guide 62 has a large inner diameter at the front and rear ends of its inner surface, which prevents the bending operation wire 44 from rubbing against each other when the bending section 7 is bent. Furthermore, since the rivet 61 and the wire guide 62 are arranged at the same position in the longitudinal direction of the bending tube 30, the trajectory of the central axis of the wire guide 62 and the running shape of the bending operation wire 44 approximately match.

[0131] As shown in FIG. 36, it is desirable that the wire guide 62 has an inner surface with a radius of curvature Rb (Ra > Rb) that is slightly smaller than the radius of curvature Ra (Rw ≒ Ra), which is approximately the same as the radius of curvature Rw of the bending operation wire 44, when the bending portion 7 is bent to a predetermined bending angle, for example, the maximum bending angle.

[0132] Furthermore, when the wire guide 62 has an inner surface with a radius of curvature Rb, an edge E is created at the base end, so it is desirable to form the inner surface with an even smaller radius of curvature Rc (Rb>Rc) so that the base end portion is chamfered.

[0133] Furthermore, while FIG. 36 illustrates the radii of curvature R for the inner surface of the base end side of the wire guide 62, it is preferable that the inner surface of the tip end side of the wire guide 62 has a similar configuration, as shown in FIG.

[0134] 38 , each of the node rings 31, 32, 33, 34, 35, and 36 has a semicircular recess 37e that is slightly deformed formed on the tip side of the hole 37d of the first convex portion 37a or the second convex portion 37b. That is, the hole 37d of the first convex portion 37a or the second convex portion 37b has a recess 37e that is slightly deformed formed around the tip side, within a very small range that does not cause axial misalignment of the joint portion 37. Note that, because the recess 37e of the hole 37d has a slight shape, the hole area is only slightly enlarged.

[0135] The recess 37e is formed at a position on the protruding side of the first protrusion 37a or the second protrusion 37b, in this case, the distal end side. That is, when the bending section 7 of the endoscope 1 is bent, the shaft member generates a compressive force in a direction pressing each of the node rings 31, 32, 33, 34, 35, and 36 toward the proximal end. Therefore, the recess 37e is formed on the distal end side of the hole 37d where no compressive force is generated by the shaft member.

[0136] The inventions described in the above embodiments and modifications are not limited to these embodiments and modifications, and various modifications can be made in the implementation stage without departing from the spirit of the invention. Furthermore, the above embodiments and modifications include inventions at various stages, and various inventions can be extracted by appropriate combinations of the disclosed multiple constituent elements.

[0137] For example, if some constituent elements are deleted from all the constituent elements shown in the embodiments and variants, and the stated problem can be solved and the stated effect can be obtained, then the configuration from which these constituent elements are deleted can be extracted as an invention.

[0138] This application claims priority from U.S. Provisional Application No. 63 / 631,469 filed April 9, 2024, the contents of which are incorporated herein by reference in their entirety, including the specification, claims, and drawings.

[0139] REFERENCE SIGNS LIST 1 endoscope 2 insertion section 3 operation section 4 universal cable 6 distal end section 7 bending section 8 flexible tube section 11 gripping section 12 UD bending operation knob 13 RL bending operation knob 14 bending operation knob 15 air / water supply button 16 suction button 17 treatment tool elevator operation lever 18 treatment tool insertion channel insertion section 20 endoscope connector 21 distal end configuration section 30 bending tube 30a first joint ring group 30b second joint ring group 31 most distal joint ring 31a most distal joint ring preparation 32 first joint ring 32a first joint ring preparation 33 second joint ring 33a second joint ring preparation 34 first intermediate joint ring 34, 35 ... intermediate node ring 34a ... first intermediate node ring preparatory body 34b ... end surface 35 ... second intermediate node ring 35a ... intermediate node ring preparatory body 36 ... most proximal node ring 36a ... most proximal node ring preparatory body 37 ... joint portion 37a ... first convex portion 37b ... second convex portion 37c ... burring 37d ... hole portion 37e ... recessed portion 38a ... first joint end portion 38b ... second joint end portion 40 ... bending rubber 41 ... wire retaining member 42, 43 ... wire guide 44 ... bending operation wire 45 ... first joint welded portion 45a ... first joint welded portion 46 ... recessed portion 46a ... base end surface 47 ... second joint welded portion 47a ... end surface 47b ... end surface 48 ... groove 48a ... Hole portion 48b ... elongated hole 51 ... stepped pin 52 ... pin 55 ... first recess 56 ... second recess 57 ... third recess 58 ... fourth recess 61 ... rivet 62 ... wire guide 100 ... processed sheet 101 ... first press processed sheet 102 ... second press processed sheet 103 ... curved pipe processed sheet 104, 108 ... carrier 105 ... pilot hole 106 ... die punch 107 ... bridge 109 ... pilot hole 110 ... die punch 111 ... bridge 120 ... press jig

Claims

1. A manufacturing method of a bending tube to be attached to an insertion instrument, comprising: forming, from a sheet material, an expanded shape of a plurality of nodal rings, each connected by a plurality of joints; forming, by press working, a plurality of first nodal rings having a first diameter about a longitudinal axis and a plurality of second nodal rings having a second diameter different from the first diameter from the sheet material from which the expanded shapes of the plurality of nodal rings have been formed; forming, for at least one of the first nodal rings or the second nodal rings, at least one abutting portion that abuts against an end face of the other first nodal ring or the second nodal ring, which is substantially perpendicular to the longitudinal axis, by bending a part of the sheet material in a direction intersecting the longitudinal axis; and joining the at least one abutting portion formed on one of the first nodal rings or the second nodal rings to the end face of the other of the first nodal rings or the second nodal rings.

2. A method for manufacturing a bending tube according to claim 1, characterized in that a plurality of the second node rings are formed, in which a plurality of the joint portions for bending the bending tube in a direction including a first directional component perpendicular to the longitudinal axis and a plurality of the joint portions for bending the bending tube in a direction including a second directional component perpendicular to the longitudinal axis are alternately arranged.

3. The method for manufacturing a bending tube according to claim 2, characterized in that the abutment portion is formed at a position shifted around the longitudinal axis with respect to the joint portion of the first node ring or the second node ring of the one of the first node rings or the joint portion closest to the other first node ring or the second node ring.

4. The method for manufacturing a bending tube according to claim 3, characterized in that the abutment portion is formed on the side where the angle at which the plurality of node rings are bent around the longitudinal axis is the largest.

5. A method for manufacturing a bending tube as described in claim 1, characterized in that a protrusion extending from the end of the first node ring or the second node ring is bent in a direction away from the longitudinal axis to form the abutment portion.

6. The method for manufacturing a bending tube according to claim 5, characterized in that the abutting portion is set to a dimension that protrudes from the outer periphery of the other of the first node ring or the second node ring.

7. The method for manufacturing a bending tube according to claim 1, characterized in that the developed shape of the plurality of node rings is formed by press working the sheet material.

8. A method for manufacturing a bending tube according to claim 1, characterized in that the first node ring and the second node ring are formed from the same sheet material by punching and rolling using a press.

9. A method for manufacturing a bending tube according to claim 8, wherein the first node ring and the second node ring are simultaneously formed from the same sheet material by press working.

10. A method for manufacturing a bending tube according to claim 8, characterized in that the abutment portion is formed simultaneously when the first node ring and the second node ring are formed by press working.

11. A method for manufacturing a curved tube as described in claim 1, characterized in that a plurality of the first and second node rings are punched out of a sheet material at the same time using a press, adjacent first and second node rings are connected together, and then formed by rolling.

12. The method for manufacturing a bending tube according to claim 1, characterized in that the abutment portion and the surface of the longitudinal end of the other of the first node ring or the second node ring are joined by laser welding.

13. A method for manufacturing a curved tube as described in claim 12, characterized in that the laser welding is performed by irradiating a laser at a predetermined angle with respect to the longitudinal axis direction onto the contact portion between the abutting portion and the surface of the longitudinal axis end of the other of the first node ring or the second node ring.

14. A method for manufacturing a curved tube as described in claim 12, characterized in that the first node ring and the second node ring are formed by punching and rolling the sheet material using a press, and opposing portions of the base material formed on the sheet material by the rolling process are joined to each other by laser welding.

15. A method for manufacturing a curved tube as described in claim 14, characterized in that the portions where the base materials face each other are formed with unevenness by the rounding process, and the joint portions where the unevenness is combined are joined by spot welding.

16. The method for manufacturing a bending tube according to claim 12, wherein a guide member for guiding the elongated member inserted through the node ring is joined to the inner surface of the node ring by laser welding.

17. A bending tube to be attached to an insertion device, characterized in that it has bending components including: a first nodal ring having a first diameter about the longitudinal axis, formed by pressing a sheet material made of a metal plate; a second nodal ring having a second diameter about the longitudinal axis different from the first diameter, formed by pressing the sheet material; an abutment portion formed integrally with at least one of the first nodal ring or the second nodal ring by bending the first nodal ring or the second nodal ring, the abutment portion abutting against the surface of the end in the longitudinal direction of the other first nodal ring or the second nodal ring; and a joint portion joining the abutment portion to the surface of the end in the longitudinal direction.

18. The bending tube according to claim 17, characterized in that the first node ring is connected to another of the first node rings or the second node rings by a pair of joints provided in a second direction perpendicular to the first direction so that the bending tube bends in a first direction intersecting the longitudinal axis, and the second node ring is connected to one of the first node rings or the other of the second node rings by a pair of joints provided in the second direction so that the second node ring bends in the first direction, and the abutment portion is provided at a position shifted around the longitudinal axis from the position of the joint portion closest to the other of the first node rings or the second node rings with which it abuts.

19. An insertion device comprising: an insertion section to be inserted into a subject; a bending tube attached to the distal end of the insertion section having a plurality of nodal rings, including: a first nodal ring formed by pressing a sheet material made of a metal plate and having a first diameter about the longitudinal axis; a second nodal ring formed by pressing the sheet material and having a second diameter different from the first diameter about the longitudinal axis; an abutment portion formed integrally with at least one of the first nodal ring and the second nodal ring by bending the other, the abutment portion abutting against the surface of the end in the longitudinal axis direction of the other first nodal ring or the second nodal ring; and a joint portion joining the abutment portion to the surface of the end in the longitudinal axis direction.

20. The insertion device according to claim 19, which is a single-use endoscope that is disposed of after a single use.

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