Method for manufacturing a curved tube, curved tube and insertion device

Abstract

In a method of manufacturing a bent pipe, an unfolded shape of a plurality of link rings connected by a plurality of joint portions is formed from a sheet material, a plurality of first link rings having a first diameter about a length axis and a plurality of second link rings having a second diameter different from the first diameter are respectively formed by press working, for one of the first link rings and the second link rings, a portion of the sheet material is bent to form an abutting portion that abuts an end surface of the other of the first link rings and the second link rings that is substantially perpendicular to the length axis, and the abutting portion is engaged with the end surface of the other of the first link rings and the second link rings.

Description

Technical Field

[0001] The present invention relates to a method for manufacturing a curved tube disposed in a curved portion of an insertion device such as an endoscope, and to the curved tube itself. Background Technology

[0002] Typically, an endoscope, as an insertion device, has a slender insertion section that is inserted into a body cavity. This insertion section is connected to an operating section on the base side. The insertion section has a front end, a curved section, and a flexible tube section. The front end is composed of a rigid front end (front end component). The front end is connected to the front end of the curved section. The curved section is connected to the front end of the flexible tube section. The curved section bends to allow the direction of the front end to change. The flexible tube section is a slender and flexible tube.

[0003] The bent portion of the insertion section has a bent tube, a braided layer consisting of a metal mesh covering the bent tube, and an outer skin covering the outer side of the braided layer. The outer skin is a tube body made of rubber material or the like covering the outer circumference of the bent tube. The bent tube has multiple joint rings. The multiple joint rings are arranged side by side in the length direction of the bent portion. Adjacent joint rings are rotatably connected to each other.

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

[0005] Japanese Patent Application Publication Nos. 2010-252859 and 2007-159636 disclose techniques for manufacturing curved tubes for endoscopes by stamping. Furthermore, International Patent Publication No. WO2016 / 190011 discloses a structure in which a portion of the shape of a curved tube for endoscopes is formed by stamping, and a curved operating line or a curved operating line mounting device is fused to a curved tube segment ring.

[0006] Existing technical documents

[0007] Patent documents

[0008] Patent Document 1: Japanese Patent Application Publication No. 2010-252859

[0009] Patent Document 2: Japanese Patent Application Publication No. 2007-159636

[0010] Patent Document 3: International Publication WO2016 / 190011 Summary of the Invention

[0011] The problem that the invention aims to solve

[0012] However, bent tubes are structures made by overlapping stamped sheet materials and joining multiple adjacent rings of the same diameter, as in the past. However, when making bent tubes using stamped sheet materials, it is difficult to join two rings of different diameters together integrally.

[0013] Therefore, in the existing technology or combinations thereof, there is a problem of high cost when manufacturing bent tubes with joint rings that have diameter variations. That is, bent tubes made from stamped sheet material are limited by the forming process in terms of the diameter variation of the joint rings. Therefore, bent tubes made from stamped sheet material have the problem of not being able to have the desired diameter variation, such as the expansion structure.

[0014] Therefore, the curved tubes manufactured by conventional stamping processes have the following problems: it is not easy to form a curved section with a diameter variation to eliminate the effects of increased burden on the patient, insertion into the subject, and observation.

[0015] The present invention was made in view of the above circumstances, and its object is to provide a method for manufacturing a curved tube for endoscopes with varying diameters that simplifies the manufacturing process and reduces costs, thereby enabling low-cost production of the curved tube.

[0016] Methods for solving problems

[0017] In one embodiment of the present invention, a method for manufacturing a bent tube for installation in an insertion device, a sheet material is formed into an unfolded shape of multiple segmented rings connected by multiple joints. The sheet material with the unfolded shape of the multiple segmented rings is stamped to form multiple first segmented rings having a first diameter centered on a length axis and multiple second segmented rings having a second diameter different from the first diameter. For at least one of the first segmented rings and the second segmented rings, a portion of the sheet material is bent in a direction intersecting the length axis to form at least one abutting portion that abuts against the end face of the other of the first segmented rings and the other substantially perpendicular to the length axis. The at least one abutting portion formed on one of the first segmented rings and the second segmented rings is engaged with the end face of the other of the first segmented rings and the second segmented rings.

[0018] One aspect of the present invention is a bent tube installed in an insertion device, wherein the bent tube has a bending component comprising: a first ring formed by stamping a sheet material made of a metal plate, having a first diameter centered on a length axis; a second ring formed by stamping the sheet material, having a second diameter different from the first diameter centered on the length axis; an abutment portion integrally formed by bending at least one of the first and second rings, abutting against the surface of the other of the first and second rings at its length axis end; and a joining portion engaging the abutment portion with the surface of the length axis end.

[0019] An insertion device according to one aspect of the present invention includes: an insertion portion inserted into a subject; and a curved tube mounted on the front end side of the insertion portion, the curved tube having a plurality of segments, the curved tube comprising: a first segment formed by stamping a sheet material made of a metal plate, having a first diameter centered on a length axis; a second segment formed by stamping the sheet material, having a second diameter different from the first diameter centered on the length axis; an abutment portion integrally formed by bending at least one of the first and second segments, abutting against a surface of the other segment's length axis end; and a joining portion joining the abutment portion to the surface of the length axis end.

[0020] Invention Effects

[0021] According to the present invention, the manufacturing process of curved tubes with varying diameters can be simplified, thereby reducing costs and enabling low-cost production. Attached Figure Description

[0022] Figure 1 This is a diagram showing the structure of an endoscope.

[0023] Figure 2 It is a cross-sectional view showing the structure of the front end of the insertion part and the curved part.

[0024] Figure 3 It is a top view showing a processed piece that has gone through multiple processing stations.

[0025] Figure 4 This is a top view showing the first stamped sheet.

[0026] Figure 5 This is a top view showing the second stamping sheet.

[0027] Figure 6 This is a top view showing the bending tube processing sheet.

[0028] Figure 7 This is a cross-sectional view showing the stamping process of expanding the flange processing section using stamping tools.

[0029] Figure 8 This is a sectional view showing the joint.

[0030] Figure 9 This is a top view of a bent tube processing piece showing the state in which the two sides of each ring preparation body are separated from the carrier.

[0031] Figure 10 It is a diagram showing the state of each ring after it has been bent.

[0032] Figure 11 This is a top view of a bent tube sheet showing the state of each section after bending.

[0033] Figure 12 It is a diagram showing the state in which the first and second joint ends of each segment ring are spot-welded after bending.

[0034] Figure 13 This diagram shows the state of the first and second ring groups before they are joined together.

[0035] Figure 14 This diagram shows the state in which the first and second ring groups are engaged.

[0036] Figure 15 It is a perspective view showing the engagement state of the first and second joint welded parts.

[0037] Figure 16 This is a partial cross-sectional view showing the state in which the first and second joint welded parts are embedded and laser welded.

[0038] Figure 17 It is a partial sectional view showing the dimensional relationship between the first and second joint welded parts.

[0039] Figure 18 It is a top view that partially shows the dimensional relationship between the first and second joint welded parts.

[0040] Figure 19 This is a partial cross-sectional view showing the joint between the first and second ring assemblies.

[0041] Figure 20 It is a partial cross-sectional view showing the state in which the end face of the base end of the second joint welded part abuts against the end face of the front end of the first intermediate ring when the bent part is at its maximum bending.

[0042] Figure 21 The first variation is a diagram showing the way four curved operating lines are fixed to the frontmost joint ring.

[0043] Figure 22 The first variation is a diagram showing the way two curved operating lines are fixed to the frontmost joint ring.

[0044] Figure 23 The second variation is a perspective view showing the joining method of the first and second joint welded parts, partially viewed from the top front end.

[0045] Figure 24 The second variation is a perspective view showing the joining method of the first joint weld and the second joint weld in a state viewed from above the base end.

[0046] Figure 25 In the second variation, the first and second joint welds are partially shown in a configuration viewed from above the front end. Figure 23 and Figure 24 Three-dimensional diagrams of different joining methods.

[0047] Figure 26 In the second modified example, the first and second joint weld portions are partially shown in a configuration viewed from above the base end. Figure 23 and Figure 24 Three-dimensional diagrams of different joining methods.

[0048] Figure 27 In the second modified example, the first and second joint weld portions are partially shown in a configuration viewed from above the base end. Figure 26 Three-dimensional diagrams of different joining methods.

[0049] Figure 28 The first reference example is a cross-sectional view showing a configuration in which stepped pins are provided to engage the left and right sides of the first and second joint rings.

[0050] Figure 29 The first reference example is a cross-sectional view showing a configuration in which pins are provided to engage the left and right sides of the first and second joint rings.

[0051] Figure 30 The second reference example is a perspective view showing a recess formed on the upper part of the first joint weld portion, partially viewed from the upper front side.

[0052] Figure 31 The second reference example is a partial cross-sectional view showing a surface engagement achieved through recesses formed on the upper and lower sides of the first and second joint rings.

[0053] Figure 32The second reference example is a perspective view showing a recess formed on the side of the first joint weld portion, partially viewed from the top of the front end.

[0054] Figure 33 The second reference example is a partial cross-sectional view showing a surface engagement achieved through recesses formed on the left and right sides of the first and second joint rings.

[0055] Figure 34 The third reference example is a partial cross-sectional view of a curved tube in which a guide wire is integrally formed at the joint and bent at a specified angle.

[0056] Figure 35 The third reference example is a partial cross-sectional view showing the structure of a wire conductor integrally formed at the joint.

[0057] Figure 36 The third reference example is a partial cross-sectional view showing the curvature structure of the inner circumferential surface on the base end side of the conductor.

[0058] Figure 37 The third reference example is a partial cross-sectional view showing the curvature structure of the inner circumferential surfaces of the front end and base end of the conductor.

[0059] Figure 38 The fourth reference example is a diagram showing a structure in which the holes of the protrusions of the joint rings are formed into irregularly shaped concave portions. Detailed Implementation

[0060] (Implementation Method)

[0061] Hereinafter, an endoscope will be used as an example to describe the insertion device of this embodiment. Furthermore, the accompanying drawings for each embodiment are illustrative in the following description. It should also be noted that the thickness-to-width relationship and thickness ratio of the various components of the endoscope differ from reality. Moreover, the various components of the endoscope may sometimes include parts with different dimensional relationships and ratios relative to each other in the accompanying drawings.

[0062] First, the general structure of the endoscope 1, which is used as an insertion device, will be described. In addition, the endoscope 1 here has a structure that can be applied to various endoscopes such as upper gastrointestinal endoscopes, lower gastrointestinal endoscopes, bronchoscopes, ureteroscopes, and duodenoscopes.

[0063] Furthermore, the endoscope 1, which is an insertion device, can be a single-use endoscope that is discarded after use, either in whole or in part, or a reusable endoscope that is reused after being processed.

[0064] Figure 1 The endoscope 1 shown in this embodiment is an insertion device having an insertion part 2, an operation part 3, and a universal cable 4. The insertion part 2 is a long, thin, strip-shaped component that is inserted into the subject. The universal cable 4 is a composite cable. The insertion part 2 has, in sequence from its front end, a front end 6, a bend 7, and a flexible tube 8.

[0065] The operating unit 3 is rotatably equipped with a bending operation knob 14 for bending the bending part 7 of the insertion part 2. In addition, the operating unit 3 includes an air / water supply button 15, a suction button 16, and a treatment device lifting lever 17.

[0066] The bending operation knob 14 is arranged in an overlapping manner with two roughly disc-shaped rotary knobs: the UD bending operation knob 12 and the RL bending operation knob 13. The UD bending operation knob 12 is an operating component for bending the bending section 7 in the vertical direction. The RL bending operation knob 13 is an operating component for bending the bending section 7 in the horizontal direction.

[0067] The operating unit 3 has a gripping part 11 and a processing device insertion channel insertion part 18. The gripping part 11 is the part that is operated by the user.

[0068] A treatment device insertion channel insertion portion 18 is disposed on the holding portion 11. This treatment device insertion channel insertion portion 18 serves as an opening for inserting various treatment devices into the treatment device insertion channel provided in the insertion portion 2. A pliers bolt is provided in this treatment device insertion channel insertion portion 18.

[0069] A universal cable 4 extends from the operation unit 3. An endoscope connector 20, which is detachable from a light source device (not shown), is provided at the extension end of the universal cable 4. The endoscope connector 20 connects to a coiled cable (not shown), at the extension end of which an electrical connector is detachable from a video processor (not shown). Furthermore, the shape of the connector 20 can be various other shapes as needed, besides the shape shown.

[0070] In addition, in this embodiment, the endoscope 1 transmits illumination light from the light source device (not shown) to the front end 6 through the light guide beam (not shown) of the illumination unit that is inserted into the insertion part 2, the operation part 3 and the universal cable 4.

[0071] Next, the curved portion 7, which is a tubular portion constituting part of the insertion portion 2 of the endoscope 1, will be described in detail below. The curved portion 7 has a curved component that serves as a snake-bone component in the curved part.

[0072] like Figure 2As shown, the insertion part 2 has a front end of a curved tube 30 composed of multiple segmented rings connected to the front end component 21. The front end component 21 is a generally cylindrical rigid front end component built into the front end part 6. The curved tube 30 is composed of multiple segmented rings 31, 32, 33, 34, 35, and 36 as bending blocks. These multiple segmented rings 31, 32, 33, 34, 35, and 36 are connected to each other along the length axis X of the central axis of the straight insertion part 2 and are in a generally circular shape.

[0073] Specifically, the curved tube 30 has, from the front end side, a front end ring 31, a first connecting ring 32, a second connecting ring 33, a plurality of alternately connected first intermediate rings 34, a plurality of second intermediate rings 35, and a base end ring 36 connected along the length axis X.

[0074] These multiple joints 31, 32, 33, 34, 35, and 36 are rotatably connected via joints 37, which serve as pivot supports. The foremost joint 31 is connected to the foremost end portion 21 of the foremost end portion 6. The basemost joint 36 is connected to a tube body, such as a spiral tube (not shown), located within the flexible tube portion 8.

[0075] The curved tube 30 is covered by a curved rubber 40, which serves as the outer skin. A braided layer (not shown) such as a metal braid is provided on the inner circumference of the curved rubber 40. The front end portion of the curved rubber 40 is fastened to the outer circumference of the front end component 21 by a winding adhesive part (not shown).

[0076] The insertion part 2 is internally provided with multiple elongated components that serve as built-in elements. Specifically, four bending operation lines 44 are inserted into the insertion part 2 as elongated components for bending the bending part 7.

[0077] In addition, long components such as optical guides, camera cables, and various channels (not shown) are inserted into the insertion section 2. Furthermore, these long components extend from the insertion section 2 into the operation section.

[0078] The front ends of each of the four bending operation lines 44 are fixed to the line fixing member 41 of the front end component 21. The four bending operation lines 44 are traction-relaxation operation to cause the bending tube 30 to rotate around the joint 37. As a result, the bending section 7 is bent in the up, down, left and right directions in the viewing screen.

[0079] That is, the bending tube 30 is alternately provided with: a plurality of joints 37 for bending the bending tube 30 in a direction that includes a first directional component perpendicular to the length axis X, namely the up and down direction; and a plurality of joints 37 for bending the bending tube 30 in a direction that includes a second directional component perpendicular to the length axis X, namely the left and right direction.

[0080] In addition, multiple wire guides 42 and 43, which serve as wire receiving parts for the bending operation line 44 to be inserted, are joined to the inner circumferential surfaces of each of the rings 32, 33, 35, and 36, except for the foremost ring 31 and each of the first intermediate rings 34. The multiple wire guides 42 and 43 are guide members for guiding the bending operation line 44, which is a long strip component.

[0081] Here, the manufacturing method of the bent tube 30 disposed in the bending section 7 will be described. Furthermore, the bent tube 30 of this embodiment is mass-produced by automatic stamping processing based on a dedicated stamping press and a stamping supply device.

[0082] Specifically, the bent tube 30 is manufactured through a sheet-making process based on progressive stamping, an overlapping process based on transfer processing, a shape-cutting process, and a bending process.

[0083] like Figure 3 As shown, for example, a sheet is produced by using a stamping machine (not shown) to process a roll of sheet material such as stainless steel with a thickness of 0.2 mm to 1.0 mm. In this sheet production process, a sheet 100 of the sheet material is produced after passing through multiple processing stations. These multiple processing stations include positioning using a guide, punching, pre-punching, stamping, edge punching, cutting (1, 2), back pressing, hole trimming, stepped bending, and side cutting.

[0084] The processed piece 100 manufactured in this way is cut into pieces through the final cutting process of progressive stamping. Figure 4 The first stamping sheet 101 and Figure 5 The two sheets, the first stamping sheet 101 and the second stamping sheet 102, are made from the same metal coil simultaneously.

[0085] like Figure 4 As shown, a plurality of joint ring preparation bodies 32a, 33a, 35a, etc. are formed on the first stamping sheet 101. The plurality of joint ring preparation bodies 32a, 33a, 35a have an arc-shaped first protrusion 37a that serves as a pivot support mechanism for the joint portion 37.

[0086] A plurality of guide holes 105 and a plurality of outer shape cutting portions 106 are formed on the first stamping sheet 101. Each guide hole 105 is formed on the first stamping sheet 101 through a carrier 104 that serves as the blanking edge material. Each guide hole 105 is a hole into which a guide pin (not shown) that defines the stamping position of the first stamping sheet 101 is inserted.

[0087] Each of the external cut-out portions 106 is a portion formed by cutting off a metal coil using a mold (not shown) in accordance with the external shape of the first joint joint ring preparation body 32a, the second joint joint ring preparation body 33a, the (second) intermediate joint ring preparation body 35a, etc., which are multiple joint ring preparation bodies.

[0088] The first joint ring preparation body 32a is the base material that forms the first joint ring 32. On the first joint ring preparation body 32a, a pair of first joint welding portions 45 are formed in the vertical direction of the bending portion 7. Each first joint welding portion 45 is formed to protrude from one edge of the first joint ring preparation body 32a (opposite to the second joint ring preparation body 33a described later) toward the base end side.

[0089] A recess 46 is formed in the center of each first joint welding portion 45. That is, each first joint welding portion 45 is a U-shaped protrusion towards the base end.

[0090] The second joint ring preparation body 33a is the base material that becomes the second joint ring 33. The second joint ring preparation body 33a has a pair of second joint welding portions 47 formed in the vertical direction of the bending portion 7. Each second joint welding portion 47 is formed to protrude from the edge of the second joint ring preparation body 33a opposite to the second intermediate joint ring preparation body 35a toward the base end side.

[0091] Each second joint weld portion 47 is configured to fit into the recess 46 of the first joint weld portion 45. Each second joint weld portion 47 is bent into a bent portion that is approximately right-angled (≈90°) toward the radially outward side of the second joint ring 33 by a bending process described later. In addition, the (second) intermediate ring preparation body 35a is the base material that becomes the second intermediate ring 35.

[0092] like Figure 5 As shown, multiple segmental rings 31a, 34a, 36a, etc. are formed on the second stamping sheet 102.

[0093] Multiple joint ring preparation bodies 31a, 34a, and 36a have arc-shaped second protrusions 37b that serve as pivot support mechanisms for joint portions 37. Furthermore, the first joint ring preparation body 32a and the second joint ring preparation body 33a are connected by a bridge 107. The bridge 107 is blank material that serves as the connecting portion to be cut off later.

[0094] The second stamping sheet 102 also has a plurality of guide holes 109 and a plurality of outer trimming portions 110. Each guide hole 109 is formed on the second stamping sheet 102 by punching or the like, serving as a carrier 108 for the trimming edge material. Each guide hole 109 is also a hole for inserting a guide pin (not shown) that defines the stamping position of the second stamping sheet 102.

[0095] Each of the externally cut-out portions 110 is also a portion formed by cutting off the metal coil using a mold (not shown) in accordance with the external shape of the foremost segment ring preparation body 31a, the first intermediate segment ring preparation body 34a, the base segment ring preparation body 36a, etc., which are multiple segment ring preparation bodies.

[0096] The foremost segment ring preparation body 31a is the base material that becomes the foremost segment ring 31. The foremost segment ring preparation body 31a is connected to the carrier 108 via the bridge 111. The bridge 111 is also the blank material for the connecting part that will be cut off later.

[0097] The first intermediate segment ring preparation body 34a is the base material that becomes the first intermediate segment ring 34. The base end segment ring preparation body 36a is the base material that becomes the base end segment ring 36. The base end segment ring preparation body 36a is also connected to the carrier 108 by a bridge 111, which serves as a connecting part that will be cut off later.

[0098] Furthermore, each of the second protrusions 37b of the second stamping sheet 102 has a flange portion 37c (see reference). Figure 7 The flange 37c is an annular portion that protrudes from a surface by stamping in a predetermined direction (upward direction) through pre-holes in each of the second protrusions 37b.

[0099] Next, the two second joint weld portions 47 of the second joint ring 33 are bent at approximately a right angle (90°) toward the radially outer surface of the bent tube 30 by stamping. That is, the second joint weld portions 47 are formed by bending the protrusions extending from the end of the second joint ring 33 away from the length axis X.

[0100] Regarding the first stamping sheet 101 and the second stamping sheet 102 manufactured as described above, as follows: Figure 6 As shown, a first stamping sheet 101 is superimposed on a second stamping sheet 102. In this way, a bent tube sheet 103 is produced. At this time, the flange portion 37c of each second protrusion 37b of the second stamping sheet 102 is inserted into the hole portion of each first protrusion 37a of the first stamping sheet 101.

[0101] Furthermore, the overlapping process of the first stamping sheet 101 and the second stamping sheet 102 is automatically conveyed by the stamping supply device. Additionally, the bending tube sheet 103 is conveyed to various stamping processes such as blanking and bending using a transfer device for stamping processing.

[0102] like Figure 7 As shown, the bending tube processing piece 103 undergoes a stamping process in which the flange portion 37c of each second protrusion 37b is expanded on the inserted first protrusion 37a using a stamping tool 120. Thus, the bending tube processing piece 103 is formed with... Figure 8The joints 37 are shown. Thus, the joint preparation bodies 31a, 32a, 33a, 34a, 35a, and 36a are connected.

[0103] Moreover, such as Figure 9 As shown, the two sides of each segment ring preparation body 31a, 32a, 33a, 34a, 35a, and 36a in the bent tube processing piece 103 are cut off from the carriers 104 and 108 by stamping. At this time, a concave first joint end 38a and a convex second joint end 38b are formed on both sides of each segment ring preparation body 31a, 32a, 33a, 34a, 35a, and 36a by punching (cutting).

[0104] Thus, a substrate is formed on the bending tube processing sheet 103 with the unfolded shapes of each segment ring 31, 32, 33, 34, 35, and 36. In addition, there is a state in which the bridge 107 connecting the first joint ring 32 and the second joint ring 33 and the bridge 111 connecting the foremost segment ring 31 or the base segment ring 36 to the carrier 108 remain.

[0105] Moreover, such as Figure 10 As shown, each of the rings 31, 32, 33, 34, 35, and 36 is bent (curled) into a cylindrical surface with a curvature radius of approximately R6 by means of the first joint end 38a and the second joint end 38b fitting together.

[0106] In addition, the outer diameter (Φ) of each ring 31, 32, 33, 34, 35, and 36 is set to a range of, for example, 6.0 mm for the fine diameter and 13.0 mm for the coarse diameter, depending on the plate thickness (0.2 mm to 0.5 mm).

[0107] like Figure 12 As shown, after bending, the first joint ends 38a and the second joint ends 38b of each segment ring 31, 32, 33, 34, 35, and 36 are spot welded SW by laser welding or other means. That is, the opposing portions of each first joint end 38a and each second joint end 38b are fitted together and spot welded SW.

[0108] At this time, each end face of one of the first joint ends 38a and each of the second joint ends 38b becomes an abutment portion that abuts against each end face of the other of the first ring assembly 30a and the second ring assembly 30b. Each end face that becomes an abutment portion is along the length axis X direction of the first ring assembly 30a and the second ring assembly 30b. Furthermore, each abutment portion is joined by spot welding SW. In addition, each end face of the first joint end 38a abutting against each of the second joint ends 38b is a plane in the thickness direction of each of the first joint end 38a and the second joint end 38b.

[0109] Furthermore, to improve assemblability, each first joint end 38a and each second joint end 38b has a convex-concave shape with a joint q of less than 1 mm. In addition, spot welding SW is performed at approximately 3 to 7 points relative to the joint of one first joint end 38a and one second joint end 38b.

[0110] Thus, a first ring group 30a and a second ring group 30b are formed on the bending tube processing piece 103. The first ring group 30a is formed by connecting the foremost ring 31 and the first connecting ring 32 using a joint portion 37. The second ring group 30b is formed by connecting the second connecting ring 33, a plurality of intermediate rings 34 and 35 and the base ring 36 using a joint portion 37.

[0111] Furthermore, the outer diameter d1 of the first joint ring 32 of the first ring assembly 30a is set to be larger than the outer diameter d2 of the second joint ring 33 of the second ring assembly 30b (d1 > d2). That is, the bending tube processing piece 103 here stamps out the first ring assembly 30a, which constitutes the front joint with a large diameter, and the second ring assembly 30b, which constitutes the rear joint with a small diameter, in the bending tube 30.

[0112] Furthermore, the first ring assembly 30a and the second ring assembly 30b are separated from the bending tube processing piece 103. Then, wire guides 42 and 43 (not shown) are laser-welded to the first ring assembly 30a and the second ring assembly 30b from the outer periphery direction. Alternatively, the laser welding of wire guides 42 and 43 can also be performed simultaneously with laser spot welding SW at the joints of each first joint end 38a and each second joint end 38b. Additionally, wire guides 42 and 43 can also be fixed to the first ring assembly 30a and the second ring assembly 30b by brazing, bonding, or other methods.

[0113] The first ring assembly 30a and the second ring assembly 30b are assembled together after the wire guides 42 and 43 are welded. Specifically, as... Figure 13 and Figure 14 As shown, the first engaging ring 32 of the first ring assembly 30a engages with the second engaging ring 33 of the second ring assembly 30b. The first engaging ring 32 is engaged such that its base portion covers the front end portion of the second engaging ring 33.

[0114] At this point, use assembly aids (not shown), such as... Figure 15As shown, a pair of upper and lower second joint welded portions 47 are fitted into the recesses 46 of the upper and lower first joint welded portions 45 in the bending direction of the bent portion 7. Furthermore, the end face 47a of the second joint welded portion 47, which bends at approximately a right angle (≈90°) to the radially outward side of the first joint ring 32, abuts against the base end face 46a, which forms the edge of the recess 46 of the first joint welded portion 45. That is, each second joint welded portion 47 abuts against the surface of the end portion of the first joint ring 32 in the longitudinal axis direction.

[0115] Each of the second joint welding portions 47 of the abutment portion is located at a predetermined angle, approximately 90° in this case, around the length axis X which is the central axis, relative to the joint portion 37 closest to the abutment first joint ring 32. In addition, each of the second joint welding portions 47 is located on the side of the maximum angle of bending of the curved portion 7 around the length axis X, i.e., in the vertical direction.

[0116] Furthermore, each first joint welded portion 45 and each second joint welded portion 47 are joined by laser welding (LW). At this time, the base end face 46a and end face 47a of the opposing surfaces of the first joint welded portion 45 and each second joint welded portion 47, which are the longitudinal axis ends of the first ring assembly 30a or the second ring assembly 30b, form an abutting portion that abuts against each other. Moreover, each abutting portion is joined by laser welding (LW). Additionally, the base end face 46a and end face 47a are planes perpendicular to the longitudinal axis X of the bent tube 30 where the first ring assembly 30a and the second ring assembly 30b are joined.

[0117] Thus, the bent tube 30 here is a structure in which the first joint ring 32 of the first ring group 30a and the second joint ring 33 of the second ring group 30b, which have different diameters, are joined by laser welding LW.

[0118] In addition, each of the first joint welding parts 45 and each of the second joint welding parts 47 can also be joined by spot welding SW, bonding or other methods.

[0119] Therefore, the first joint ring 32 and the second joint ring 33 are integrated into a single joint ring. Thus, a curved tube 30 is formed by joining the first joint ring group 30a, which has a larger diameter at the front end, and the second joint ring group 30b, which has a smaller diameter at the base end.

[0120] In addition, during laser welding of the first joint welding portion 45 and the second joint welding portion 47, the second joint welding portion 47 is respectively fitted into the recesses 46 of the upper and lower first joint welding portions 45 in the bending direction of the bent portion 7.

[0121] Therefore, the left-right positions of the first joint ring 32 and the second joint ring 33 are restricted when the bending portion 7 is bent. Moreover, the first joint ring 32 and the second joint ring 33 are aligned with their respective central axes, i.e., the length axis X, by an assembly tool not shown, and the up-down direction is restricted when the bending portion 7 is bent.

[0122] like Figure 16 As shown, laser welding (LW) is performed from the outer diameter side of the second joining weld portion 47 toward the ridge line of the recess 46 of the first joining weld portion 45 that contacts and abuts the second joining weld portion 47, in a direction substantially perpendicular to the surface of the first joining weld portion 45. Alternatively, laser welding (LW) can be performed from the back side of the second joining weld portion 47 in an inclined direction having a predetermined angle θ through which the second joining weld portion 47 passes. Furthermore, the laser welding (LW) that joins the first joining weld portion 45 and the second joining weld portion 47 can be automated using a dedicated laser welding apparatus.

[0123] Thus, the joining method of the first joint ring 32 and the second joint ring 33 with different diameters, by using laser welding LW, can suppress the reduction of the internal space volume of the bent tube 30 (pressure on the built-in) compared with the riveting joint often used by stamping.

[0124] Here, the dimensional relationship between the first joint weld portion 45 of the first joint ring 32 and the second joint weld portion 47 of the second joint ring 33 will be explained. First, as Figure 17 and Figure 18 As shown, the plate thickness T of the first joint ring 32 and the second joint ring 33 is set to, for example, 0.2 mm to 0.5 mm (T=0.2 to 0.5). In addition, the diameter Φ of the bent tube 30 is set to range from a small diameter of 6 mm (Φ=6.0) to a large diameter of 13 mm (Φ=13.0).

[0125] like Figure 17 As shown, the gap b between the first joint ring 32 and the second joint ring 33 is, for example, 0.25 mm (b=0.25 mm). In addition, the radius of curvature R of the inner side of the second joint weld portion 47, which is bent at approximately a right angle (≈90°) to the radially outward side of the second joint ring 33, is, for example, 0.1 mm (R=0.1 mm).

[0126] In this case, the height H of the second joint welded part 47 is set to be at least 2T+R (H≥2T+R), which is the sum of twice the plate thickness T of the first joint ring 32 and the second joint ring 33 and the radius of curvature R. When the plate thickness T of the first joint ring 32 and the second joint ring 33 is set to 0.3mm (T=0.3), the height H of the second joint welded part 47 is, for example, 0.75mm (H=0.75mm), which is at least 0.70mm.

[0127] Based on these dimensional relationships, the second joining weld portion 47 has a height H that protrudes from the surface of the first joining weld portion 45. When the height H of the second joining weld portion 47 is set to 0.75 mm (H = 0.75 mm), the protrusion amount h is 0.2 mm (h = 0.2). Furthermore, the protrusion amount h is set to be in the range of 0 mm to 0.5 mm (0 ≤ h ≤ 0.5).

[0128] Furthermore, even if the engagement positions of the first joint ring 32 and the second joint ring 33 are offset in the vertical direction, the protrusion h of the second joint weld portion 47 still satisfies the dimensional condition that the difference obtained by subtracting the radius of curvature R of the inner side of the second joint weld portion 47 from the gap b between the first joint ring 32 and the second joint ring 33 is greater than the difference (h > bR). This ensures the welding area of ​​the second joint weld portion 47 to the first joint weld portion 45.

[0129] Thus, the second joining weld portion 47 is set with a height H that slightly protrudes from the first joining weld portion 45 in the outer diameter direction to facilitate laser welding of LW. If the second joining weld portion 47 does not protrude, the wall thickness will be insufficient during laser welding of LW. Therefore, during stamping, the second joining weld portion 47 is preferably positioned to protrude beyond the surface of the first joining weld portion 45.

[0130] Furthermore, since the edge of the second joint weld portion 47 becomes rounded during laser welding (LW), it is impossible to damage the curved rubber 40 covering the curved tube 30. That is, the protrusion height of the second joint weld portion 47 is reduced and the cross-section becomes rounded due to laser welding (LW), thus reducing the possibility of damaging the curved rubber 40.

[0131] like Figure 18 As shown, the width W1 of the recess 46 in the first joining weld portion 45 is, for example, 2.0 mm (W1=2.0). Furthermore, the width W2 of the two side portions of the first joining weld portion 45 that sandwich the recess 46 is the same size, for example, 1.0 mm (W2=1.0). That is, the width W1 of the recess 46 formed in the first joining weld portion 45 is twice the width W2 of the two side portions (W1=2W2).

[0132] When the plate thickness T of the second joining weld portion 47 is set to 0.3 mm (T=0.3), the depth t of the recess 46 formed in the first joining weld portion 45 is, for example, set to 0.25 mm. That is, the depth t of the recess 46 is a dimension that is 0.05 mm shorter than the plate thickness T (0.3 mm) of the fitted second joining weld portion 47 (T > t). As a result, the second joining weld portion 47 protrudes further towards the base end than the first joining weld portion 45.

[0133] When the width W1 of the recess 46 of the first joining weld portion 45 is, for example, 2.0 mm (W1=2.0), the range P of the laser welding LW that joins the first joining weld portion 45 and the second joining weld portion 47 is, for example, set to about 1.4 mm (P≈1.4). In the laser welding LW, as a condition, the pulse width with an output of 400 to 800 watts (W) is set to 0.5 to 10 milliseconds.

[0134] Because the second joint weld portion 47 protrudes further towards the base end than the first joint weld portion 45, therefore... Figure 19 and Figure 20 As shown, when the bending portion 7 is bent to its maximum extent, the end face 47b on the base end side reliably abuts against the end face 34b on the front end side of the first intermediate ring 34. As a result, the accuracy of the bending function of the bending portion 7 is improved.

[0135] In addition, as a method for manufacturing the aforementioned bent tube 30, it is preferable to first join the first ring group 30a with a larger diameter and the second ring group 30b with a smaller diameter by laser welding LW.

[0136] Furthermore, after the guide wires 42 and 43 are installed in the first ring assembly 30a and the second ring assembly 30b, the first joint welding part 45 and the second joint welding part 47 are joined by laser welding (LW). This is because if the first ring assembly 30a and the second ring assembly 30b with different diameters are first laser welded (LW), the guide wires 42 will have parts that are difficult to join by laser welding (LW).

[0137] In the above method, the sheet metal is stamped to produce stamped sheets 101 and 102, which are then overlapped to form a bent tube sheet 103. While bending (rolling) the bent sheet 103, each segment ring 31, 32, 33, 34, 35, and 36 is processed separately, so that the joint ends interlock to form a cylindrical surface. In this method, as long as the first segment ring group 30a and the second segment ring group 30b are in an unconnected state, it is possible to simultaneously generate the first segment ring group 30a and the second segment ring group 30b with different diameters.

[0138] However, in the segmented ring assembly (a segmented ring assembly formed by continuously connecting the portion corresponding to the first segmented ring assembly 30a and the portion corresponding to the second segmented ring assembly 30b), the diameter changes drastically in the middle. Therefore, it is very difficult to bend (curl) such a segmented ring assembly in a manner in which the portion corresponding to the first segmented ring assembly 30a and the portion corresponding to the second segmented ring assembly 30b share a common length axis X, and the joint ends of each segmented ring 31, 32, 33, 34, 35, 36 are all fitted together.

[0139] Alternatively, the segmented ring assembly (a segmented ring assembly formed by continuously connecting a portion corresponding to the first segmented ring assembly 30a and a portion corresponding to the second segmented ring assembly 30b) with a significantly different diameter as described above can be meticulously stamped in several stages along with multiple additional steps. However, in this case, the number of processing steps increases significantly, thus greatly increasing the manufacturing cost.

[0140] Therefore, in the manufacturing method of the bent tube 30 in this embodiment, the first ring group 30a and the second ring group 30b of different diameters are stamped (transfer processing) and cut off from the bent tube processing piece 103. Then, the first ring group 30a and the second ring group 30b are joined together.

[0141] Furthermore, the spot weld SW that joins the first joint end 38a of each ring segment 31, 32, 33, 34, 35, and 36 to the convex second joint end 38b can be performed by laser welding LW. Therefore, the aforementioned spot weld SW can share the same laser welding device as the laser welding LW that joins the first ring segment group 30a and the second ring segment group 30b, thus unifying the welding process.

[0142] In the above-described method for manufacturing the bent tube 30, considering mass production capabilities including cost, two first stamping sheets 101 and a second stamping sheet 102 are obtained by forming a roll of the same sheet metal material by stamping an unfolded substrate of multiple rings 31, 32, 33, 34, 35, 36.

[0143] Furthermore, in the manufacturing method of the bent tube 30, the first stamping sheet 101 and the second stamping sheet 102 are overlapped and stamped to form a joint 37 that connects multiple joint rings 31, 32, 33, 34, 35, and 36 to form a freely rotating joint.

[0144] Next, in the manufacturing method of the bent tube 30, multiple rings 31, 32, 33, 34, 35, and 36 are rolled by stamping to form the first ring group 30a and the second ring group 30b with different diameters into a first stamped sheet 101 and a second sheet 102 as sheet materials.

[0145] Subsequently, in the manufacturing method of the bent tube 30, the first ring assembly 30a and the second ring assembly 30b with different diameters are joined together in other processes. Furthermore, the bent tube 30 here becomes a structure with a diameter variation between the large-diameter first ring assembly 30a and the small-diameter second ring assembly 30b.

[0146] Furthermore, in order to enable the vicinity of the front end side to bend significantly in the vertical direction by means of joints 37 arranged continuously at short intervals in the same direction, the bending tube 30 is provided with a first joint welding portion 45 and a second joint welding portion 47 in the vertical direction, which are connecting portions of a first joint ring 32 and a second joint ring 33 that are joints of different diameters. Moreover, the bending tube 30 increases the number of joints 37 provided on the left and right sides to increase the bending angle in the vertical direction.

[0147] According to the above description, the bending tube 30 can be manufactured by stamping, which can eliminate the constraints of forming based on expansion forming and other diameter expansion processes. The desired diameter expansion structure can be achieved by a joint ring formed by the first joint ring 32 and the second joint ring 33.

[0148] Previously, in order to connect multiple joints to make a curved tube 30 with varying diameters, it was necessary to expand the diameter of multiple joints through complex forming processes such as bulging.

[0149] Due to forming constraints, bending tubes with varying diameters require different diameter settings for each of the multiple joint rings. Therefore, the processing types and steps for bending tubes with varying diameters increase. In other words, manufacturing costs for bending tubes with varying diameters rise with the processing time.

[0150] Furthermore, in conventional automated stamping processes, it is difficult to manufacture curved tubes 30 with varying diameters. In contrast, the curved tube 30 of this embodiment is simplified through stamping and laser welding, enabling low-cost manufacturing while suppressing increased production costs. Thus, the curved tube 30 of this embodiment helps reduce manufacturing costs when used in disposable endoscopes 1 where a low price is desired.

[0151] Furthermore, the curved tube 30 of this embodiment has a different diameter for example, the segments 31, 32, 33, 34, 35, and 36, compared to the conventional curved tube used in the existing endoscope 1. The purpose is to minimize the diameter of the curved portion 7 in which the curved tube 30 is built in order to ensure the insertability of the insertion portion 2 of the endoscope 1.

[0152] However, the front end 6 of the insertion part 2 needs a certain diameter to accommodate the implant. In the endoscope 1, if the diameter of the curved part 7 is made to match the diameter of the front end 6 of the insertion part 2, the curved part 7 will unnecessarily become a large diameter. Therefore, there are concerns about increased burden on the patient (the object being examined) during surgery, as well as the impact on the insertability and observation of the insertion part 2.

[0153] Furthermore, the insertion portion 2 of the endoscope 1 is desired to have a smaller diameter to improve insertion into the object being examined. Therefore, in the structure of the curved tube 30 of this embodiment, the first ring assembly 30a connected to the front end 6 is configured to have a larger diameter to match the diameter of the front end 6, and the second ring assembly 30b connected to the base end of the first ring assembly 30a is configured to have a smaller diameter.

[0154] Therefore, the curved tube 30 of this embodiment, by having a segmental ring structure with varying diameter, can improve the impact on the patient's burden and the insertability and observation of the insertion part 2 of the endoscope 1, which is an insertion device.

[0155] Based on the above explanation, the manufacturing method and structure of the curved tube 30 of this embodiment simplify the manufacturing process of the curved tube 30 of the endoscope 1, which is an insertion device with a variable diameter, and achieve low-cost and low-price manufacturing. Therefore, by using the curved tube 30 of this embodiment in the curved portion 7 of the insertion portion 2 of the endoscope 1, etc., an insertion device, a structure is achieved that eliminates the increased burden on the patient or other subject, and the negative impacts on the insertability and observation of the subject.

[0156] (First variation)

[0157] like Figure 21 As shown, the four bending operation lines 44 can also be configured such that their respective front ends are fixed to four line fixing members 41, which are connected to the frontmost segment ring 31 on the upper, lower, left, and right sides of the bending tube 30 around the length axis X, by crimping or the like. That is, four bending operation lines 44 are provided here, and the front ends of each are fixed to the line fixing members 41. Alternatively, the structure of fixing the front ends of each bending operation line 44 to the frontmost segment ring 31 can be replaced by fusion welding or brazing.

[0158] In addition, such as Figure 22 As shown, it can also be in the following configuration: two bending operation lines 44 are inserted into the upper and right, and lower and left portions of the bending tube 30 around the length axis X, into the foremost segment ring 31. Each bending operation line 44 is arranged along the outer periphery from the upper portion toward the right or from the lower portion toward the left of the foremost segment ring 31, and the insertion portion penetrating into the foremost segment ring 31 is fixed by fusion welding or brazing.

[0159] (Second variation)

[0160] Regarding the joining structure of the first ring group 30a and the second ring group 30b, which are unequal diameter ring groups, it can also be as follows: Figure 23 as well as Figure 24 The configuration shown is such that a convex first joint welding portion 45a protruding from the base end of the first joint ring 32 fits into the groove 48 of two second joint welding portions 47 that bend radially outward from the front end of the second joint ring 33, and is joined by laser welding LW.

[0161] Furthermore, the joining structure of the first ring group 30a and the second ring group 30b, which are unequal diameter ring groups, can also be as follows: Figures 25 to 27 The configuration shown is such that the first joining weld portion 45a is fitted into a hole portion 48a or an elongated hole 48b of a second joining weld portion 47 formed in a radially outward bending manner from the end of the second joining joint ring 33, and is joined by laser welding LW.

[0162] In addition to laser welding (LW), the joining of the first joining weld 45a and the second joining weld 47 can also be done by spot welding (SW), bonding, etc.

[0163] (First Reference Example)

[0164] As a method for joining the different diameter joint rings, namely the first joint ring 32 and the second joint ring 33, based on the laser welding LW of the first joint welding part 45 and the second joint welding part 47, it is also possible to... Figure 28 As shown, the stepped pin 51 is used for engagement in the left-right direction. In addition, the stepped pin 51 is also engaged with the first engagement welding part 45 and the second engagement welding part 47 by laser welding LW, spot welding SW, bonding, etc.

[0165] Furthermore, as a method for joining the reducing joint rings, namely the first joining joint ring 32 and the second joining joint ring 33, based on the laser welding LW of the first joining weld portion 45 and the second joining weld portion 47, it is also possible to... Figure 29 As shown, they are joined in the left-right direction by pin 52. Here, pin 52 is also joined with the first joining weld 45 and the second joining weld 47 by laser welding LW, spot welding SW, bonding, etc.

[0166] In this way, by adding stepped pins 51 or 52 in the left and right directions, the different diameter joint rings, namely the first joint ring 32 and the second joint ring 33, can strengthen the joint strength of the first joint weld 45 and the second joint weld 47 based on laser welding LW.

[0167] In this way, the engagement of the first connecting ring 32 and the second connecting ring 33, which uses stepped pins 51 or 52, can be achieved from the outer circumferential direction by laser welding (LW), spot welding (SW), bonding, or other methods. Therefore, processing constraints and design constraints on the interior of the bent tube 30 are reduced. Furthermore, regarding the engagement method of the first connecting ring 32 and the second connecting ring 33, which are reducing rings, although not shown, it could also be a welding engagement of the half-punch portions.

[0168] (Second Reference Example)

[0169] As a method for joining the different diameter joint rings, namely the first joint ring 32 and the second joint ring 33, it is also possible to not provide the first joint welding part 45 and the second joint welding part 47.

[0170] Specifically, such as Figure 30 and Figure 31 As shown, a first recess 55 that partially protrudes radially inward is formed on the upper and lower surfaces of the first joint ring 32 with a larger diameter, and a second recess 56 that partially protrudes radially outward is formed on the upper and lower surfaces of the second joint ring 33 with a smaller diameter.

[0171] Then, the surface of the first joint ring 32 protruding inward through the first recess 55 is brought into contact with the surface of the second joint ring 33 protruding outward through the second recess 56, and the first joint ring 32 and the second joint ring 33 are joined by laser welding (LW), spot welding (SW), bonding, etc.

[0172] Moreover, such as Figure 32 and Figure 33 As shown, a third recess 57 that protrudes radially inward can be formed on the left and right sides of the first joint ring 32 with a larger diameter, and a fourth recess 58 that protrudes radially outward can be formed on the left and right sides of the second joint ring 33 with a smaller diameter, so that the surfaces protruding through the third recess 57 and the fourth recess 58 are in contact, and the first joint ring 32 and the second joint ring 33 are joined by laser welding (LW), spot welding (SW), bonding, etc.

[0173] In the second reference example, an example is shown where pairs of recesses 55 and 56 are formed on the upper and lower sides of the first connecting ring 32 and the second connecting ring 33. However, depending on the difference in the outer shape of the first connecting ring 32 and the second connecting ring 33, only one of the recesses 55 and 56 may be formed. Similarly, in the second reference example, an example is shown where pairs of recesses 57 and 58 are formed on the left and right sides of the first connecting ring 32 and the second connecting ring 33. However, depending on the difference in the outer diameter of the first connecting ring 32 and the second connecting ring 33, only one of the recesses 57 and 58 may be formed. Furthermore, each of the recesses 55, 56, 57, and 58 is formed in the stamping process by semi-blanking, embossing, etc.

[0174] (Third Reference Example)

[0175] The endoscope 1, serving as an insertion device, is equipped with a tubular wire receiving portion, namely a wire guide 42, brazed to the inner surface of the rear end side of each segment ring. In this configuration, when the bending shape of the bending operation wire 44 matches the bending state of each segment ring 31, 32, 33, 34, 35, and 36, the trajectory of the central axis of the bending operation wire 44 does not match the trajectory of the central axis of the wire guide 42. Therefore, the bending operation wire 44 rubs against the wire guide 42, particularly the rear end portion, thereby increasing the bending force.

[0176] The difference between the front and rear ends of the wire guide 42 due to machining on the rear end side deteriorates its manufacturability. For example, if the rear end of the wire guide 42 is thinned to eliminate wire snagging, the solder will flow towards the inner surface of the wire guide during brazing, further deteriorating manufacturability.

[0177] Furthermore, if the rear end of the wire guide 42 is made thinner, the gap between the bending operation line 44 and the wire guide 42 will locally increase, and the pressure of the bending operation line 44 on the wire guide 42 will decrease, thus causing each ring 31, 32, 33, 34, 35, and 36 to sway.

[0178] Therefore, as Figure 34 and Figure 35 As shown, the curved tube 30 here is integrally formed with rivets 61 that allow the various rings 34, 35 (31, 32, 33, 36) to rotate freely together and wire connectors 62 that serve as wire receiving parts.

[0179] Furthermore, the inner diameter h2 of the front and rear ends of the inner surface of the wire guide 62 is larger than the inner diameter h1 of the center. That is, the wire guide 62 is formed such that the edge of the inner surface is arc-shaped in a cross section passing through the central axis Z. Moreover, this arc is set to be smaller than the radius of curvature of the bending portion 7 (≈ the radius of curvature of the bending operation line 44).

[0180] The guide wire 62 is configured such that by increasing the inner diameter of the front and rear ends of the inner surface, friction of the bending operation line 44 can be prevented when the bending section 7 is bent. In addition, since the rivet 61 and the guide wire 62 are positioned at the same position in the longitudinal direction of the bending tube 30, the trajectory of the central axis of the guide wire 62 is approximately consistent with the travel shape of the bending operation line 44.

[0181] In addition, such as Figure 36 As shown, the conductor 62 is preferably configured to have an inner surface with a radius of curvature Rb (Ra>Rb) that is slightly smaller than the radius of curvature Ra (Rw≈Ra) of the bending operation line 44 when the bending portion 7 is bent at a predetermined bending angle, such as the maximum bending angle.

[0182] Furthermore, if the conductor 62 forms an inner surface with a radius of curvature Rb, an edge E is generated at the base end. Therefore, it is preferable to form an inner surface with a smaller radius of curvature Rc (Rb > Rc) by chamfering the base end portion.

[0183] In addition, Figure 36 In the diagram, the radii of curvature R are illustrated for the inner surface of the base end side of the conductor 62, but as... Figure 37 As shown, the inner surface of the front end side of the preferred wire guide 62 also has the same structure.

[0184] (Fourth Reference Example)

[0185] like Figure 38 As shown, each of the joint rings 31, 32, 33, 34, 35, and 36 has a semi-circular recess 37e of a tiny, irregular shape formed on the front end side of the hole 37d of the first protrusion 37a or the second protrusion 37b. That is, the irregularly shaped recess 37e is formed around the front end side of the hole 37d of the first protrusion 37a or the second protrusion 37b, and this recess 37e is only within a very small range that does not cause axial displacement of the joint 37. Furthermore, because the recess 37e is of a tiny shape, the increase in the hole area of ​​the hole 37d is very small.

[0186] The recess 37e is formed on the protruding side of the first protrusion 37a or the second protrusion 37b, which is the front end side. That is, when the curved portion 7 of the endoscope 1 is bent, a compressive force is generated by the shaft member, pressing each of the segment rings 31, 32, 33, 34, 35, and 36 towards the base end side. Therefore, the recess 37e is formed on the front end side of the hole portion 37d where no compressive force is generated by the shaft member.

[0187] The invention described in the above embodiments and modifications is not limited to these embodiments and modifications. In addition, various modifications can be made during the implementation phase without departing from its spirit. Furthermore, the above embodiments and modifications include inventions at various stages, and various inventions can be extracted through appropriate combinations of the disclosed constituent elements.

[0188] For example, even if some constituent elements are deleted from all the constituent elements shown in the embodiments and variations, the above-mentioned problems can be solved. When the above-mentioned effects can be obtained, the structure in which the constituent element is deleted can be extracted as an invention.

[0189] This application is based on priority claims made in U.S. Provisional Application No. 63 / 631469, filed April 9, 2024, the contents of which are incorporated herein by reference in the specification, claims and drawings.

[0190] Label Explanation

[0191] 1: Endoscope; 2: Insertion section; 3: Operations Department; 4: General purpose cables; 6: Front end; 7: Curved section; 8: Flexible tube section; 11: Controlling part; 12: UD bendable operation knob; 13: RL bend operation knob; 14: Bend the operating knob; 15: Gas / water delivery button; 16: Attraction button; 17: Lifting lever for handling equipment; 18: Insertion section of the treatment device insertion channel; 20: Endoscope connector; 21: Front-end structure department; 30: Bending pipe; 30a: First ring assembly; 30b: Second ring group; 31: The foremost segment; 31a: The frontmost segment preparation body; 32: First joint ring; 32a: Preparation body for the first joint ring; 33: Second joint ring; 33a: Preparation body for the second joint ring; 34: First intermediate ring; 34, 35: Intermediate rings; 34a: Preparation body for the first intermediate ring; 34b: End face; 35: Second intermediate ring; 35a: Preparation body for intermediate segment ring; 36: The most basic segmental ring; 36a: Preparation body for the most basic segment ring; 37: Joints; 37a: first convex part; 37b: second convex part; 37c: Flanged part; 37d: Hole portion; 37e: concave part; 38a: First mating end; 38b: Second mating end; 40: Bending rubber; 41: Wire fixing components; 42, 43: Conductor; 44: Bending operation line; 45: First joint welded part; 45a: First joint welded part; 46: concave part; 46a: Base end face; 47: Second joint welded part; 47a: End face; 47b: End face; 48: trough; 48a: Hole section; 48b: Elongated aperture; 51: Stepped pin; 52: Sales; 55: first concave part; 56: second concave part; 57: The third concave part; 58: The fourth concave part; 61: Rivet; 62: Conductor; 100: Processed sheet; 101: First stamping sheet; 102: Second stamping sheet; 103: Bending tube processing sheet; 104, 108: Carrier; 105: Guide hole; 106: Shaped blanking section; 107: Bridge; 109: Guide hole; 110: Shaped blanking section; 111: Bridge; 120: Pressure assistive device. Claims (as amended under Article 19 of the Treaty) 1. [Modified] A method for manufacturing a bent tube, characterized in that, The unfolded shape is formed from sheet material into multiple segmental rings connected along the length axis by multiple joints. A first segment ring with a first diameter and a second segment ring with a second diameter different from the first diameter are formed by stamping from a sheet material having an unfolded shape of multiple segment rings. A portion of the sheet material is bent in a direction intersecting the length axis to form at least one abutting portion in one of the first and second ring segments. The abutting portion abuts against the end face of the other of the first and second ring segments and engages. 2. The method for manufacturing a bent tube according to claim 1, characterized in that, A plurality of second ring segments are formed, the plurality of second ring segments being alternately provided with a plurality of joints for bending the curved tube in a direction including a first direction component perpendicular to the length axis and a plurality of joints for bending the curved tube in a direction including a second direction component perpendicular to the length axis. 3. The method for manufacturing a bent tube according to claim 2, characterized in that, The abutment portion is formed at a position offset about the length axis from the joint portion of the joint portion closest to the other of the first and second ring segments, relative to one of the first and second ring segments. 4. The method for manufacturing a bent tube according to claim 3, characterized in that, The abutment portion is formed on the side where the bending angle of the plurality of joint rings is largest, with the length axis as the center. 5. The method for manufacturing a bent tube according to claim 1, characterized in that, The protrusion extending from the end of the first or second ring is bent away from the length axis to form the abutment portion. 6. [Modified] The method for manufacturing a bent tube according to claim 5, characterized in that, The abutting portion is positioned in a direction that protrudes from the outer periphery of the other of the first and second ring segments. 7. The method for manufacturing a bent tube according to claim 1, characterized in that, The sheet material is stamped to form the unfolded shape of multiple rings. 8. The method for manufacturing a bent tube according to claim 1, characterized in that, The first ring and the second ring are formed from the same sheet material by stamping and rolling processes. 9. The method for manufacturing a bent tube according to claim 8, characterized in that, The first ring and the second ring are simultaneously formed from the same sheet material by stamping. 10. The method for manufacturing a bent tube according to claim 8, characterized in that, The abutting portion is formed simultaneously during the stamping process of forming the first ring section and the second ring section. 11. The method for manufacturing a bent tube according to claim 1, characterized in that, Multiple first rings and second rings are simultaneously punched from sheet material, adjacent first rings and second rings are connected, and then rolled to form the shape. 12. The method for manufacturing a bent tube according to claim 1, characterized in that, The abutment portion is joined to the surface of the longitudinal axis end of the other of the first and second ring segments by laser welding. 13. The method for manufacturing a bent tube according to claim 12, characterized in that, Laser welding is performed by irradiating the contact portion of the abutment portion with the surface of the other end of the first ring and the second ring along the length axis direction with a laser at a predetermined angle relative to the length axis direction. 14. The method for manufacturing a bent tube according to claim 12, characterized in that, The first and second ring sections are formed by stamping and rolling the sheet material. The laser welding is used to join the opposing portions of the substrate formed on the sheet material by the rolling process. 15. The method for manufacturing a bent tube according to claim 14, characterized in that, The substrate has opposing portions formed with concave and convex shapes through the rolling process, and the joint portions formed by the combination of the concave and convex shapes are joined by spot welding. 16. The method for manufacturing a bent tube according to claim 12, characterized in that, A guide component is joined to the inner surface of the segment ring using laser welding. This guide component guides the elongated component inserted into the segment ring. 17. A curved tube, mounted on an insertion device, characterized in that, The bent tube has a bending component, which includes: The first ring is formed by stamping a sheet of material made of metal plate, and has a first diameter centered on the length axis; The second ring is formed by stamping the sheet material and has a second diameter different from the first diameter, centered on the length axis; The abutting portion, which is integrally formed by bending at least one of the first and second ring segments, abuts against the surface of the longitudinal axis end of the other of the first and second ring segments; and A joint that engages the abutment portion with the surface at the end in the length axis direction. 18. The bent tube according to claim 17, characterized in that, The first ring segment is connected to other first or second ring segments via a pair of joints in a second direction perpendicular to the first direction, so that the bent tube bends in the first direction intersecting the length axis. The second ring is connected to one or more of the first rings via a pair of joints disposed in the second direction, so that the bent tube bends in the first direction. The abutting portion is located at a position offset around the length axis from the joint portion closest to the other of the abutting first and second ring segments. 19. An insertion device, characterized in that the insertion device comprises: The insertion part is inserted into the body of the patient being examined; and A curved tube, which is installed at the front end of the insertion part, has multiple segmental rings. The curved tube includes: The first ring is formed by stamping a sheet of material made of metal plate, and has a first diameter centered on the length axis; The second ring is formed by stamping the sheet material and has a second diameter different from the first diameter, centered on the length axis; The abutting portion, which is integrally formed by bending at least one of the first and second ring segments, abuts against the surface of the longitudinal axis end of the other of the first and second ring segments; and A joint that engages the abutment portion with the surface at the end in the length axis direction. 20. The insertion device according to claim 19, characterized in that, The insertion device is a disposable endoscope that is discarded after a single use. 21. [Additional] The method for manufacturing a bent tube according to claim 1, characterized in that, The abutment portion engages with the surface of the other end of the first and second ring segments along the length axis. 22. [Additional] The method for manufacturing a bent tube according to claim 16, characterized in that, There is a gap between the first ring and the second ring. 23. [Additional] The curved tube according to claim 17, characterized in that, There is a gap between the first ring and the second ring. 24. [Additional] The method for manufacturing a bent tube according to claim 1, characterized in that, The abutting portion bends radially outward from the outer periphery of at least one of the first ring section and the second ring section. 25. [Additional] The curved tube according to claim 17, characterized in that, The first diameter of the first ring is larger than the second diameter of the second ring. 26. [Additional] The curved tube according to claim 25, characterized in that, The first ring is located at the front end of the second ring.

Claims

1. A method for manufacturing a bent tube, wherein the bent tube is installed in an insertion device, characterized in that, The unfolded shape is formed from sheet material into multiple segmental rings connected by multiple joints. Multiple first rings with a first diameter centered on their length axis and multiple second rings with a second diameter different from the first diameter are formed from sheet material with the unfolded shape of multiple ring segments by stamping. For at least one of the first and second ring segments, a portion of the sheet material is bent in a direction intersecting the length axis to form at least one abutting portion that abuts against the end face of the other of the first and second ring segments, which is substantially perpendicular to the length axis. The at least one abutting portion formed on one of the first and second ring segments engages with the end face of the other of the first and second ring segments.

2. The method for manufacturing a bent tube according to claim 1, characterized in that, A plurality of second ring segments are formed, the plurality of second ring segments being alternately provided with a plurality of joints for bending the curved tube in a direction including a first direction component perpendicular to the length axis and a plurality of joints for bending the curved tube in a direction including a second direction component perpendicular to the length axis.

3. The method for manufacturing a bent tube according to claim 2, characterized in that, The abutment portion is formed at a position offset about the length axis from the joint portion of the joint portion closest to the other of the first and second ring segments, relative to one of the first and second ring segments.

4. The method for manufacturing a bent tube according to claim 3, characterized in that, The abutment portion is formed on the side where the bending angle of the plurality of joint rings is largest, with the length axis as the center.

5. The method for manufacturing a bent tube according to claim 1, characterized in that, The protrusion extending from the end of the first or second ring is bent away from the length axis to form the abutment portion.

6. The method for manufacturing a bent tube according to claim 5, characterized in that, The abutting portion is configured to protrude from the outer periphery of the other of the first and second ring segments.

7. The method for manufacturing a bent tube according to claim 1, characterized in that, The sheet material is stamped to form the unfolded shape of multiple rings.

8. The method for manufacturing a bent tube according to claim 1, characterized in that, The first ring and the second ring are formed from the same sheet material by stamping and rolling processes.

9. The method for manufacturing a bent tube according to claim 8, characterized in that, The first ring and the second ring are simultaneously formed from the same sheet material by stamping.

10. The method for manufacturing a bent tube according to claim 8, characterized in that, The abutting portion is formed simultaneously during the stamping process of forming the first ring section and the second ring section.

11. The method for manufacturing a bent tube according to claim 1, characterized in that, Multiple first rings and second rings are simultaneously punched from sheet material, adjacent first rings and second rings are connected, and then rolled to form the shape.

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

13. The method for manufacturing a bent tube according to claim 12, characterized in that, Laser welding is performed by irradiating the contact portion of the abutment portion with the surface of the other end of the first ring and the second ring along the length axis direction with a laser at a predetermined angle relative to the length axis direction.

14. The method for manufacturing a bent tube according to claim 12, characterized in that, The first and second ring sections are formed by stamping and rolling the sheet material. The laser welding is used to join the opposing portions of the substrate formed on the sheet material by the rolling process.

15. The method for manufacturing a bent tube according to claim 14, characterized in that, The substrate has opposing portions formed with concave and convex shapes through the rolling process, and the joint portions formed by the combination of the concave and convex shapes are joined by spot welding.

16. The method for manufacturing a bent tube according to claim 12, characterized in that, A guide component is joined to the inner surface of the segment ring using laser welding. This guide component guides the elongated component inserted into the segment ring.

17. A curved tube, mounted on an insertion device, characterized in that, The bent tube has a bending component, which includes: The first ring is formed by stamping a sheet of material made of metal plate, and has a first diameter centered on the length axis; The second ring is formed by stamping the sheet material and has a second diameter different from the first diameter, centered on the length axis; The abutting portion, which is integrally formed by bending at least one of the first and second ring segments, abuts against the surface of the longitudinal axis end of the other of the first and second ring segments; and A joint that engages the abutment portion with the surface at the end in the length axis direction.

18. The bent tube according to claim 17, characterized in that, The first ring segment is connected to other first or second ring segments via a pair of joints in a second direction perpendicular to the first direction, so that the bent tube bends in the first direction intersecting the length axis. The second ring is connected to one or more of the first rings via a pair of joints disposed in the second direction, so that the bent tube bends in the first direction. The abutting portion is located at a position offset around the length axis from the joint portion closest to the other of the abutting first and second ring segments.

19. An insertion device, characterized in that, The insertion device has: An insertion part, which is inserted into the body being examined; as well as A curved tube, which is installed at the front end of the insertion part, has multiple segmental rings. The curved tube includes: The first ring is formed by stamping a sheet of material made of metal plate, and has a first diameter centered on the length axis; The second ring is formed by stamping the sheet material and has a second diameter different from the first diameter, centered on the length axis; The abutting portion is integrally formed by bending at least one of the first segment ring and the second segment ring, and abuts against the surface of the other segment ring in the longitudinal axis direction. as well as A joint that engages the abutment portion with the surface at the end in the length axis direction.

20. The insertion device according to claim 19, characterized in that, The insertion device is a disposable endoscope that is discarded after a single use.

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