Bent tube for endoscope, endoscope, method for manufacturing bent tube for endoscope, and bent tube for insertion device

Abstract

A bent tube includes: a first tubular member (12); and a second tubular member (13) that has a second tongue part (33) that overlaps the end of the first tubular member (12), a protruding part (35) that is rotatably connected to the first tubular member (12) is formed on the second tongue part (33), and the end of the first tubular member (12) has a first hole (26) that penetrates the end in the radial direction of the longitudinal axis and into which the protruding part (35) is inserted. A protruding portion (26c) is formed around the opening of the first hole (26), the protruding portion (35) has a second hole (34) penetrating the protruding portion (35) in the axial direction, and a recessed portion (35b) for receiving the protruding portion (26c) is formed in the second tongue portion (33).

Description

Technical Field

[0001] The present invention relates to a bendable tube of an endoscope in which a plurality of tubular members are rotatably connected, an endoscope, a method for manufacturing the bendable tube of an endoscope, and a bendable tube of an insertion device. Background Art

[0002] The endoscope can observe the interior of the subject and perform various treatments on the interior of the subject by inserting an insertion portion into the interior of the subject such as a body cavity or a duct.

[0003] Generally, a bending portion that can be bent in multiple directions is provided at the front end side of the insertion portion of the endoscope. In the bending portion, a bending tube having multiple bending sections (tubular members) is widely used. The multiple bending sections constituting the bending tube are arranged along the length direction of the bending portion. Moreover, each adjacent bending section is rotatably connected in a partially overlapped state. The connection of the bending section can be made by rivet joint or the like.

[0004] The bending portion configured in this manner can be bent in four directions, for example, up and down and left and right, by means of an operation wire (bending wire) inserted into the bending tube.

[0005] Various technologies have been proposed in the past as endoscopes for improving the operability of such a bending section. For example, Japanese Patent Publication No. 2014-108171 discloses a technology that limits the position of a bending wire guide member based on the distance from the center of the bending section to the inner circumference of the joint section and the distance from the center of the bending section to the inner circumference of the joint section, thereby avoiding interference between the rivet member and the bending wire guide member.

[0006] Generally, when the bending joints are connected by rivet joining or the like, it is necessary to perform plastic working on the end portions of the rivets at the portions where the bending joints are overlapped.

[0007] The sliding resistance of such a connection portion is easily affected by the press load during plastic working, etc. Therefore, the worker's skill is required to connect the bending joints together without increasing the sliding resistance of the connection portion.

[0008] The present invention has been made in view of the above circumstances, and an object thereof is to provide a bending tube of an endoscope, an endoscope, a method for manufacturing a bending tube of an endoscope, and a bending tube of an insertion device that can reduce the sliding resistance between tubular members without relying on the skills of a manufacturing operator. Summary of the invention

[0009] Solutions for solving problems

[0010] A bending tube of an endoscope according to one embodiment of the present invention has the following structure, which includes: a first tubular member; and a second tubular member, which has an overlapping portion overlapping the end of the first tubular member, and a rotating shaft rotatably connected to the first tubular member is formed in the overlapping portion, the end of the first tubular member has a first hole for inserting the rotating shaft and passing through the end in the radial direction of the longitudinal axis, a convex portion is formed around the opening of the first hole, the rotating shaft has a second hole passing through the rotating shaft in the axial direction of the rotating shaft, and a concave portion for receiving the convex portion is formed in the overlapping portion.

[0011] An endoscope according to one embodiment of the present invention has the following structure: an insertion portion has a bendable bending portion, the bending portion includes: a first tubular member; and a second tubular member, which has an overlapping portion overlapping an end portion of the first tubular member, a rotating shaft rotatably connected to the first tubular member is formed in the overlapping portion, the end portion of the first tubular member has a first hole for inserting the rotating shaft and passing through the end portion in the radial direction of the longitudinal axis, an annular convex portion is formed around the opening of the first hole, the rotating shaft has a second hole passing through the rotating shaft in the axial direction of the rotating shaft, and an annular concave portion for receiving the convex portion is formed in the overlapping portion.

[0012] A method for manufacturing a bending tube of an endoscope according to one embodiment of the present invention comprises: (a) a process of forming a first hole of a specified inner diameter in a first plate; (b) a process of forming a convex portion around the first hole in a first surface of the first plate; (c) a process of forming a rotating shaft that can be inserted into the first hole in a second plate and forming a second hole that passes through the rotating shaft in an axial direction; (d) a process of forming a concave portion around the rotating shaft to receive the convex portion; (e) a process of inserting the rotating shaft into the first hole from the first surface side so that the convex portion and the concave portion are opposite to each other; (f) a process of expanding the inner diameter of the second hole in the front end portion of the rotating shaft so that the outer diameter of the front end portion is expanded to be larger than the specified inner diameter; and (g) a process of bending the first plate and the second plate, joining the two ends of the first plate and the second plate to make each plate a tubular member.

[0013] A bending tube of an insertion device according to one embodiment of the present invention has the following structure, which includes: a first tubular member; and a second tubular member, which has an overlapping portion overlapping the end of the first tubular member, and a rotating shaft rotatably connected to the first tubular member is formed in the overlapping portion, the end of the first tubular member has a first hole for inserting the rotating shaft and passing through the end in the radial direction of the longitudinal axis, a convex portion is formed around the opening of the first hole, the rotating shaft has a second hole passing through the rotating shaft in the axial direction of the rotating shaft, and a concave portion for receiving the convex portion is formed in the overlapping portion. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 The first embodiment is a perspective view of an endoscope.

[0015] Figure 2 The first embodiment is a plan view of a bending pipe.

[0016] Figure 3 This is a perspective view showing a connected state of a first tubular member and a second tubular member according to the first embodiment.

[0017] Figure 4 In the first embodiment, Figure 2 IV-IV cross-sectional view of .

[0018] Figure 5 In the first embodiment, Figure 2 VV cross-section diagram.

[0019] Figure 6 In the first embodiment, Figure 3 VI-VI cross-sectional view.

[0020] Figure 7 In the first embodiment, Figure 2 VII-VII cross-section diagram.

[0021] Figure 8 The first embodiment is a flowchart showing a manufacturing process of a bent pipe.

[0022] Fig.9A The first embodiment is a plan view showing a state after the first hole machining step is performed on the first plate material.

[0023] Fig. 9B The first embodiment shows a state after the chamfering process is performed. Fig.9A IX-IX cross-section diagram.

[0024] Fig. 9C This is a plan view showing the shape of a convex portion formed around the opening of a first hole according to the first embodiment.

[0025] Fig. 10A This is a plan view showing a state after the second hole machining step of the first plate material is performed according to the first embodiment.

[0026] Fig. 10B In the first embodiment, Fig. 10A The range X is enlarged to show the top view.

[0027] Fig.11 This is a plan view showing a state after the third hole machining step is performed on the first plate material according to the first embodiment.

[0028] Fig.12 The present invention relates to the first embodiment and is a plan view showing a state after the step bending step of the first plate material has been performed.

[0029] Fig.13A The present invention relates to the first embodiment and is a plan view showing a state after the step bending process of the first tubular member preparation has been performed.

[0030] Fig. 13B In the first embodiment, Fig.13A XIII-XIII cross-sectional view.

[0031] Fig.14A This is a plan view showing a state after the fourth hole machining step of the second plate material is performed according to the first embodiment.

[0032] Fig. 14B This is a plan view showing a state after the flanging process of the second plate material is performed according to the first embodiment.

[0033] Fig. 14C In the first embodiment, Fig. 14B Section XIV-XIV of the diagram.

[0034] Fig.15 This is a plan view showing a state after the fifth hole machining step is performed on the second plate material according to the first embodiment.

[0035] Fig.16 This is a plan view showing the state after the sixth hole machining step is performed on the second plate material according to the first embodiment.

[0036] Fig.17 This is a plan view showing the second tubular member preparation body in a state after the sixth hole machining step is performed according to the first embodiment.

[0037] Fig.18A The present invention relates to the first embodiment and is a perspective view showing a state in which a first plate member and a second plate member are overlapped and expanded by caulking.

[0038] Fig.18B This is a cross-sectional view showing a state after expansion by an expansion punch according to the first embodiment.

[0039] Fig.19 This is a plan view showing a state after the connection portion cutting step is performed according to the first embodiment.

[0040] Fig. 20 This is a plan view showing a state after the bending process is performed according to the first embodiment.

[0041] Fig.21 The first modification example according to the first embodiment is a plan view showing a modification example of the shape of the convex portion formed around the opening of the first hole.

[0042] Fig. 22 The second modification example according to the first embodiment is a plan view showing a modification example of the shape of the convex portion formed around the opening of the first hole.

[0043] Fig.23 The third modification example according to the first embodiment is a plan view showing a modification example of the shape of the convex portion formed around the opening of the first hole.

[0044] Fig.24 The fourth modification example according to the first embodiment is a plan view showing a modification example of the shape of the convex portion formed around the opening of the first hole.

[0045] Fig.25 The fifth modification example according to the first embodiment is a plan view showing a modification example of the shape of the convex portion formed around the opening of the first hole.

[0046] Fig.26 Concerning the second embodiment, Figure 3 VI-VI cross-sectional view.

[0047] Fig. 27 The present invention relates to the second embodiment and is a cross-sectional view showing a state after the flanging process of the second plate material has been performed.

[0048] Fig.28 Concerning the second embodiment, Fig. 14B Section XIV-XIV of the diagram.

[0049] Fig.29 This is a cross-sectional view showing a second embodiment after expansion by an expansion punch.

[0050] Fig.30 The second embodiment shows a state after the chamfering process is performed. Fig.9AIX-IX cross-section diagram. DETAILED DESCRIPTION

[0051] Reference Figure 1 to Figure 25 The first embodiment will be described.

[0052] In addition, in the drawings used in the following description, the scale is different for each component in order to set each component to a size that can be recognized on the drawings. Therefore, the present invention is not limited to the number of components, the shape of components, the ratio of the size of components, and the relative positional relationship of each component recorded in these drawings.

[0053] Figure 1 The endoscope 1 of the present embodiment shown is, for example, a single-use endoscope for medical use that is used only once. The endoscope 1 includes an insertion portion 2 , an operation portion 3 , and a universal cable 8 .

[0054] The insertion section 2 is a long and thin member inserted into the observation target site. The insertion section 2 is provided with a distal rigid portion 4, a bending portion 5, and a flexible tube portion 6 in order from the distal end side.

[0055] The operation section 3 is connected to the proximal end side of the flexible tube section 6. The operation section 3 is provided with an operation lever 7 and the like for bending the bending section 5 in two directions, for example, up and down.

[0056] Universal cable 8 extends from, for example, a side portion of operation unit 3. An extended end portion (not shown) of universal cable 8 can be connected to various known devices (signal processing device, light source device, air and water supply device, etc.) via a connector (not shown).

[0057] Next, regarding the configuration of the distal end side of the insertion portion 2 , the configuration of the bending portion 5 will be mainly described.

[0058] The front end rigid part 4 of the insertion part 2 is formed of a rigid member. For example, an illumination optical system for illuminating the inside of the subject and an objective optical system of an imaging unit for photographing the inside of the subject are arranged in the front end rigid part 4. In addition, for example, an air and water supply channel for supplying fluid into the subject and a treatment instrument insertion channel for guiding treatment instruments such as forceps are opened in the front end surface of the front end rigid part 4.

[0059] The bending portion 5 has a bending tube 10 (see Figure 2 ), and a flexible outer tube (not shown) made of rubber material or the like covering the outer circumference of the bending tube 10.

[0060] The bending tube 10 includes a front tubular member 11A connected to the front rigid portion 4 and a rear tubular member 11B connected to the flexible tube portion 6. In the following description, the front tubular member 11A and the rear tubular member 11B are collectively referred to as both end tubular members 11 as appropriate.

[0061] In addition, between the tubular members 11 at both ends, the bending tube 10 has a plurality of first tubular members 12 and a plurality of second tubular members 13 as bending joints. These first tubular members 12 and second tubular members 13 are respectively substantially annular in shape. In addition, the first tubular members 12 and the second tubular members 13 are alternately arranged along the longitudinal axis O direction of the insertion portion 2. Moreover, the first tubular members 12 and the second tubular members 13 adjacent to each other are rotatably connected.

[0062] like Figure 3 As shown, each of the first tubular members 12 is configured to include a first hinge portion 15 and a first peripheral wall portion 16 .

[0063] The first hinge portions 15 are provided in pairs at positions symmetrical with respect to the central axis (ie, the longitudinal axis O) of the first tubular member 12 .

[0064] The first hinge portion 15 includes a first flat plate portion 20 and a second flat plate portion 21 .

[0065] The plan view shape of the first flat plate portion 20 is a substantially elliptical shape. The first tongue portion 25 is formed at both ends of the first flat plate portion 20 in the direction of the longitudinal axis O. The first tongue portion 25 functions as a first connecting portion for overlapping and connecting the ends of the second tubular member 13. The first hole 26 is formed in the central portion of the first tongue portion 25. The first hole 26 is a hole that penetrates the first tongue portion 25 in the radial direction of the longitudinal axis O (direction orthogonal to the longitudinal axis O).

[0066] The second flat plate portion 21 is provided on both side ends of the first flat plate portion 20 .

[0067] Furthermore, a step portion 23 is formed between the first flat plate portion 20 and the second flat plate portion 21. Due to the step portion 23, the first flat plate portion 20 is arranged on the outer peripheral side of the first tubular member 12 relative to the second flat plate portion 21 by the thickness of the first tubular member 12.

[0068] The first peripheral wall portions 16 are provided in pairs between the paired first hinge portions 15 at positions symmetrical with respect to the longitudinal axis O. Furthermore, a first ridgeline 17 is formed between the first hinge portion 15 and the first peripheral wall portions 16 .

[0069] Figure 4 yes Figure 2 IV-IV cross-section diagram. Figure 4As shown in the figure, a first wire support 28 is provided on one of the pair of first peripheral wall portions 16. The first wire support 28 is formed by forming two slits extending in the circumferential direction in the first peripheral wall portion 16 and making a band-shaped portion between the two slits protrude radially inward in a C-shape. The first wire support 28 is arranged 90 degrees apart from the first flat plate portion 20 in the circumferential direction of the first tubular member 12.

[0070] As described later, the first tubular member 12 of the present embodiment is formed by processing a flat first tubular member preparatory body 12a into a tubular shape. Therefore, the first joining portion 29 is formed along the longitudinal axis O direction in the first tubular member 12 .

[0071] like Figure 3 As shown in FIG. 1 , each of the second tubular members 13 is configured to have a second hinge portion 30 and a second peripheral wall portion 31. The wall thickness of the second tubular member 13 is substantially the same as the wall thickness of the first tubular member 12.

[0072] The second hinge portions 30 are provided in pair at positions symmetrical with respect to the central axis (longitudinal axis O) of the second tubular member 13 .

[0073] The second hinge portion 30 is formed by a flat plate portion having a substantially elliptical shape when viewed from above. A second tongue portion 33 is formed at both ends of the second hinge portion 30 in the direction of the longitudinal axis O. The second tongue portion 33 functions as an overlapping portion for overlapping the end portion (the first tongue portion 25) of the first tubular member 12. Moreover, the second tongue portion 33 functions as a second connecting portion for connecting the first tongue portion 25. A protrusion 35 serving as a rotation axis is formed at the central portion of the second tongue portion 33. The protrusion 35 protrudes from the second tongue portion 33 in the outer diameter direction of the longitudinal axis O (in a direction orthogonal to the longitudinal axis O). Moreover, the protrusion 35 has a second hole 34. The second hole 34 is a hole that penetrates the second tongue portion 33 and the protrusion 35 in the radial direction of the longitudinal axis O. Such a protrusion 35 is formed, for example, by flanging.

[0074] The second peripheral wall portions 31 are provided in pairs at positions symmetrical with respect to the longitudinal axis O between the paired second hinge portions 30 .

[0075] A second ridgeline 32 is formed between the second hinge portion 30 and the second peripheral wall portion 31 configured in this manner.

[0076] Figure 5 yes Figure 2 VV cross-section diagram. Figure 3 , Figure 5As shown, a second wire support 36 is provided on one of the pair of second peripheral wall portions 31. The second wire support 36 is formed by the same manufacturing method as the first wire support 28. The second wire support 36 is arranged 90 degrees away from the second hinge portion 30 in the circumferential direction of the second tubular member 13.

[0077] As will be described later, the second tubular member 13 is formed by processing a second tubular member preparatory body 13a in a flat plate shape into a tubular shape. Therefore, a second joining portion 38 is formed in the second tubular member 13 along the longitudinal axis O direction.

[0078] The protrusion 35 of the second tubular member 13 thus constructed is inserted into the first hole 26 of the adjacent first tubular member 12. That is, in a state where the second tongue piece 33 and the first tongue piece 25 are superimposed, the protrusion 35 is inserted into the first hole 26. Then, the front end of the protrusion 35 is expanded (caulking is performed), so that the first tubular member 12 and the second tubular member 13 are rotatably connected.

[0079] Figure 6 yes Figure 3 VI-VI cross-section diagram. Figure 6 As shown, each of the first holes 26 has a uniform diameter portion 26a and an enlarged portion 26b. In addition, a convex portion 26c is formed on the inner surface of the first tongue portion 25 around the opening of the first hole 26.

[0080] In the first hole 26 , the uniform diameter portion 26 a is provided in a region close to the inner surface in the thickness direction of the first tongue piece portion 25 .

[0081] In addition, in the first hole 26, the enlarged portion 26b is provided in a region close to the outer surface in the thickness direction of the first tongue piece 25. The end of the base end side (the inner surface side in the thickness direction of the first tongue piece 25) of the enlarged portion 26b is connected to the equal diameter portion 26a. In addition, the end of the front end side (the outer surface side in the thickness direction of the first tongue piece 25) of the enlarged portion 26b is open to the outer surface of the first tongue piece 25.

[0082] The enlarged portion 26b has a tapered shape in which the inner diameter is enlarged as it goes from the base end side to the front end side. That is, the inner diameter of the enlarged portion 26b is enlarged as it goes to the front end of the protrusion 35 (rotation axis) inserted into the first hole 26. Specifically, the inner diameter of the base end side end of the enlarged portion 26b is equal to the inner diameter d1 of the same diameter portion 26a. In addition, the inner diameter d2 of the front end side end of the enlarged portion 26b is larger than the inner diameter d1 of the same diameter portion 26a. Thus, the enlarged portion 26b has, for example, a truncated cone shape.

[0083] The convex portion 26c is formed by a protrusion that protrudes along the equal diameter portion 26a in a direction opposite to the enlarged portion 26b. Therefore, when the first tubular member 12 and the second tubular member 13 are connected, the apex of the convex portion 26c contacts the outer surface of the second tongue portion 33.

[0084] The enlarged portion 26 b and the convex portion 26 c of the first hole 26 are formed by, for example, chamfering the first hole 26 as will be described later.

[0085] In addition, the inner diameter d1 of the first hole 26 connected in this way is set to be slightly larger than the outer diameter d3 of the protrusion 35 .

[0086] Furthermore, in the state where the first tubular member 12 and the second tubular member 13 are connected, a drop-off prevention member 39 for maintaining the engagement between the first hole 26 and the protruding portion 35 is formed at the front end of the protruding portion 35. The drop-off prevention member 39 is formed by expanding the front end of the protruding portion 35 to a larger expanded diameter d4 than the inner diameter d1 of the first hole 26. By means of the drop-off prevention member 39, a portion of the front end side of the protruding portion 35 is formed into a shape that imitates the surface of the enlarged portion 26b. In addition, in order to form the drop-off prevention member 39, the front end of the protruding portion 35 is expanded to a larger expanded diameter d4 than the inner diameter d1 of the first hole 26, but as long as the first tubular member 12 and the second tubular member 13 can be prevented from falling off from the connected state, the front end of the protruding portion 35 may also be expanded only to be larger than the inner diameter d1.

[0087] When the first tubular member 12 and the second tubular member 13 are connected, the first wire support 28 and the second wire support 36 are arranged 180° apart from each other in the circumferential direction of the bendable tube 10 .

[0088] The bending tube 10 configured in this manner can be bent in two directions by operation wires (not shown) inserted into the first wire support 28 and the second wire support 36 .

[0089] In addition, in the present embodiment, the bendable pipe 10 is configured to be bent in two directions, but may be configured to be bent in four directions.

[0090] When the first tubular member 12 and the second tubular member 13 are connected, the first joint portion 29 and the second joint portion 38 are arranged so that the angle from the first hinge portion 15 to the first joint portion 29 around the longitudinal axis O of the bending tube 10 is substantially the same as the angle from the second hinge portion 30 to the second joint portion 38 around the longitudinal axis O of the bending tube 10 (see FIG. Figure 3 ).

[0091] Figure 7 yes Figure 2 VII-VII cross-section diagram. Figure 2 , Figure 7As shown in FIG. 1 , each of the two-end tubular members 11 is basically configured substantially the same as the first tubular member 12. However, in the front tubular member 11A, the first tongue portion 25 is provided only on the proximal side of the longitudinal axis O direction of the first hinge portion 15. In addition, a connecting portion 49 for connecting the bending tube 10 to the front rigid portion 4 is provided on the front end side of the longitudinal axis O direction of the front tubular member 11A. On the other hand, in the rear tubular member 11B, the first tongue portion 25 is provided only on the proximal side of the longitudinal axis O direction of the first hinge portion 15. In addition, a connecting portion 49 for connecting the bending tube 10 to the flexible tube portion 6 is provided on the proximal side of the longitudinal axis O direction of the rear tubular member 11B. Except for the above, the same reference numerals are given to the components of the two-end tubular members 11 that correspond to those of the first tubular member 12, and the description thereof is omitted.

[0092] Next, a method for manufacturing the bendable pipe 10 according to the present embodiment will be described. Figure 8 2 is a flowchart showing a manufacturing process of the bendable pipe 10. Here, in the manufacturing process of the bendable pipe 10 shown below, the bendable pipe 10 is manufactured by processing the first plate material 51 and the second plate material 61.

[0093] like Figure 8 As shown, in the manufacturing process of the bending tube 10, in steps S101 to S105, the first metal plate 51 is processed. The first plate 51 is processed to form: a two-end tubular member preparation 11a, which forms the two-end tubular member 11; and a first tubular member preparation 12a, which forms the first tubular member 12.

[0094] Hereinafter, steps S101 to S105 will be described. Note that steps S101 to S105 are performed by punching with a die.

[0095] In the processing of the first plate material 51 , the first hole processing is performed on the first plate material 51 in the process of step S101 . Fig.9A 1 is a diagram showing a state after the first hole processing of the first plate 51 has been performed. Fig.9A As shown, in the first hole processing, for example, the first holes 26 corresponding to the two end tubular members 11 and the plurality of first tubular members 12 are formed on the first plate 51. In addition, in the first hole processing, a plurality of (e.g., 8) first positioning holes 59 are formed on the first plate 51.

[0096] In the next process of step S102 , the first hole 26 is chamfered. Fig. 9B : is a diagram showing the state after chamfering. Fig. 9BAs shown in FIG. 2 , the chamfering process is performed using a chamfering punch 37 and a base 41. The base 41 has a recess 41a for forming the convex portion 26c. Fig. 9B As shown, in the chamfering process, for example, the first plate 51 is placed in a state of being positioned on the base 41. At this time, the positioning relative to the base 41 is performed using, for example, the first positioning hole 59. In addition, the first surface of the first plate 51 abuts against the base 41. The first hole 26 of the first plate 51 is chamfered from the second surface side of the first plate 51 using the chamfering punch 37.

[0097] Here, in this embodiment, the first surface of the first plate 51 is a surface forming the inner peripheral surface side of the two-end tubular member 11 and the first tubular member 12. In addition, the second surface of the first plate 51 is a surface forming the outer peripheral surface side of the two-end tubular member 11 and the first tubular member 12.

[0098] By such chamfering, the enlarged portion 26b is formed in the first hole 26. Furthermore, the convex portion 26c is formed around the opening of the first hole 26.

[0099] The enlarged portion 26b is formed by chamfering the corner of the first hole 26 with a chamfering punch 37 having a tapered tip, for example, by flattening the corner of the first hole 26 at an angle of 45 degrees. Therefore, the inner diameter d2 of the end portion on the front side of the enlarged portion 26b is larger than the inner diameter d1 of the equal diameter portion 26a of the first hole 26 (see Figure 6 ).

[0100] The protrusion 26c is formed by a portion of the first plate 51 that protrudes toward the first surface due to the plastic flow of the first plate 51 caused by chamfering. Specifically, the protrusion 26c is formed by deforming the portion of the first plate 51 that protrudes due to plastic flow to imitate the shape of the recess 41a of the base 41 when chamfering is performed. As a result, the protrusion 26c is formed to protrude from the first plate 51 at approximately the same time as the corner of the first hole 26 is flattened by the chamfering punch 37. In other words, the protrusion 26c is formed at approximately the same time as the chamfering (formation of the enlarged portion 26b). Fig. 9C As shown, the shape of the protrusion 26c is, for example, annular.

[0101] In addition, the chamfering performed by the chamfering punch 37 is not limited to the chamfering of the burred surface, and may be the chamfering of the collapsed surface.

[0102] In the next process of step S103 , the second hole processing is performed on the first plate material 51 . Fig. 10A 2 is a diagram showing a state after the second hole processing of the first plate 51 has been performed. Fig. 10AAs shown, the first wire support preparation portion 28 a is formed on the first plate 51 by the second hole processing, and the first wire support preparation portion 28 a forms the first wire support 28 of the first tubular member 12 .

[0103] Fig. 10B Yes Fig. 10A The range X is enlarged in the figure. Fig. 10B As shown, the first wire support member preparation portion 28a is formed by forming a plurality of pairs of slits 27 in the first plate 51 by the second hole processing. In addition, the first wire support member preparation portion 28a is processed into a C-shape toward the radial inner side of the first tubular member 12 during the bending process of step S113 described later, for example. Thus, the first wire support member 28 is formed.

[0104] In the next process of step S104 , the third hole processing is performed on the first plate material 51 . Fig.11 2 is a diagram showing a state after the third hole processing of the first plate 51 has been performed. Fig.11 As shown, by the third hole processing, a two-end tubular member preparation body 11 a is formed to form the two-end tubular member 11 ; and a first tubular member preparation body 12 a is formed to form the first tubular member 12 .

[0105] That is, by the third hole processing, a plurality of punching holes 53 are formed at each predetermined interval in the first plate 51. Thus, a plurality of first tubular member preparations 12a arranged in a row are formed in the first plate 51. Here, the intervals between the plurality of punching holes 53 are set to be suitable for arranging the second tubular member preparations 13a. Furthermore, by the third hole processing, a pair of punching holes 54 are formed in the first plate 51. These punching holes 54 are respectively formed at both ends of the arrangement of the plurality of first tubular member preparations 12a. Thus, tubular member preparations 11a at both ends are formed in the first plate 51.

[0106] The first tongue piece 25 of the two-end tubular member preparation 11a and the first tubular member preparation 12a is formed on the first plate 51 by the punching holes 53 and 54. In each first tubular member preparation 12a, both ends of the strip-shaped portion forming the first peripheral wall portion 16 are connected to the first edge 56 of the first plate 51 via the first connecting portion 55. In addition, the end of the two-end tubular member preparation 11a on the opposite side to the side provided with the first tongue piece 25 is connected to the first edge 56 via the two-end connecting portion 58.

[0107] The eight first positioning holes 59 formed in step S101 are provided in the first edge 56. The first tubular member preparation 12a may have only one end connected to the first edge 56 via the first connecting portion 55 and the other end not connected to the first edge 56.

[0108] In the next process of step S105 , the first plate material 51 is subjected to step-bending processing. Fig.12 2 is a diagram showing a state after the step bending process of the first plate 51 has been performed. Fig.12 As shown, step portions 23 in the plate thickness direction of the first plate material 51 are formed on the both end tubular member preparations 11 a and the first tubular member preparation 12 a by step bending.

[0109] Fig.13A 1 is a diagram showing a first tubular member preparation body 12a after step bending. Fig. 13B yes Fig.13A The XIII-XIII cross-sectional view of FIG. Fig.13A , Fig. 13B As shown, the first tubular member preparation body 12a after the step-bending process forms a first hinge portion preparation portion 15a and a first peripheral wall portion preparation portion 16a.

[0110] A first ridgeline forming portion 17a is provided between the first hinge portion preparation portion 15a and the first peripheral wall portion preparation portion 16a, and the first ridgeline forming portion 17a forms the first ridgeline 17 after the bending process (step S113) to rounden the first tubular member preparation body 12a described later is performed. In addition, the first flat plate portion 20 and the second flat plate portion 21 are formed in the first hinge portion preparation portion 15a by the step portion 23. The step height difference between the first flat plate portion 20 and the second flat plate portion 21 in the step portion 23 is equal to the wall thickness of the first tubular member preparation body 12a.

[0111] Furthermore, through the step bending process of step S105, a step portion 23b is formed between the first edge 56 of the first plate 51 and each first tubular member preparatory body 12a. By providing the step portion 23b, the first edge 56 of the first plate 51 and the first flat plate portion 20 are arranged on the same plane.

[0112] In the step bending process of step S105 , similarly, the first flat plate portion 20 and the second flat plate portion 21 are formed by the step portion 23 in the both-end tubular member hinge portion preparation portion (not shown) of the both-end tubular member preparation body 11 a .

[0113] Next, in steps S106 to S109 , the second metal plate 61 is processed. The second tubular member preparatory body 13 a is formed by processing the second plate 61 , and the second tubular member preparatory body 13 a is formed into the second tubular member 13 .

[0114] Hereinafter, steps S106 to S109 will be described. In addition, each process of steps S106 to S109 is performed by punching with a die.

[0115] In the processing of the second plate material 61 , the fourth hole processing is performed on the second plate material 61 in the process of step S106 . Fig.14A 2 is a diagram showing a state after the fourth hole processing of the second plate 61 has been performed. Fig.14A As shown, in the fourth hole processing, for example, a plurality of lower holes 35a for flanging are formed on the second plate 61. These lower holes 35a are formed at positions corresponding to the second holes 34 corresponding to the plurality of second tubular members 13, respectively.

[0116] In the fourth hole processing, a plurality of (e.g., eight) second positioning holes 69 are formed in the second plate 61. The second positioning holes 69 are formed at positions corresponding to the first positioning holes 59 formed in the first plate 51, respectively.

[0117] In the next process of step S107 , the second plate material 61 is subjected to a flanging process. Fig. 14B , Fig. 14C 2 is a diagram showing the state after flanging. Fig. 14B , Fig. 14C As shown, the lower hole 35a is processed by flanging, and the protrusion 35 serving as the rotation axis of the second tubular member 13 is formed on the second plate 61. Furthermore, by the flanging, the second hole 34 penetrating in the protruding direction (axial direction of the rotation axis) of the protruding portion 35 is formed in the protruding portion 35. Thus, for example, the second hole 34 is formed in a cylindrical shape.

[0118] In the next process of step S108 , the fifth hole processing is performed on the second plate material 61 . Fig.15 2 is a diagram showing a state after the fifth hole processing of the second plate 61 has been performed. Fig.15 As shown, the second wire support member preparation portion 36a is formed on the second plate 61 by the fifth hole processing, and the second wire support member preparation portion 36a forms the second wire support member 36 of the second tubular member 13. That is, the second wire support member preparation portion 36a is formed by forming a plurality of pairs of slits 27 on the second plate 61 by the fifth hole processing. In addition, the second wire support member 36 is formed by the same manufacturing method as the first wire support member 28, for example, when performing the bending process of step S113 described later.

[0119] In the next process of step S109 , the sixth hole processing is performed on the second plate material 61 . Fig.16 2 is a diagram showing a state after the sixth hole processing of the second plate 61 has been performed. Fig.16 As shown, the second tubular member preparation 13 a is formed on the second plate material 61 by the sixth hole processing.

[0120] That is, by the sixth hole processing, a plurality of punching holes 65 are formed at predetermined intervals in the second plate 61. Thus, a plurality of second tubular member preparatory bodies 13a arranged in a row are formed in the second plate 61. Here, the intervals between the plurality of punching holes 65 are set to an interval suitable for arranging the first tubular member preparatory bodies 12a.

[0121] The second tongue portion 33 of the second tubular member preparatory body 13a is formed on the second plate 61 through each punching hole 65. In addition, in each second tubular member preparatory body 13a, both ends of the strip-shaped portion forming the second peripheral wall portion 31 are connected to the second edge 62 of the second plate 61 via the second connecting portion 68.

[0122] Furthermore, the second tubular member preliminary body 13 a may have a configuration in which only one end portion is connected to the second edge 62 via the second connecting portion 68 and the other end portion is not connected to the second edge 62 .

[0123] Fig.17 1 is a diagram showing the second tubular member preparation body 13a after the sixth hole processing. Fig.17 As shown, the second hinge portion preparation part 30a and the second peripheral wall portion preparation part 31a are formed on the second tubular member preparation body 13a. A second ridgeline forming part 32a is provided between the second hinge portion preparation part 30a and the second peripheral wall portion preparation part 31a, and the second ridgeline forming part 32a forms the second ridgeline 32 after the bending process (step S113) to make the first tubular member preparation body 12a circular is performed as described later.

[0124] Next, in the process of step S110, the first plate 51 and the second plate 61 are superimposed. The first plate 51 is the first plate 51 processed by the above-mentioned steps S101 to S105, and the second plate 61 is the second plate 61 processed by the above-mentioned steps S106 to S109.

[0125] In the stacking process of step S110 , the second plate 61 is arranged with the protrusion 35 of the second tongue portion 33 protruding upward. The first plate 51 is stacked on the second plate 61 with the first flat plate portion 20 arranged above the second flat plate portion 21 .

[0126] At this time, the first plate 51 and the second plate 61 are superimposed by a positioning mechanism in the mold, etc. Specifically, the first plate 51 and the second plate 61 are superimposed in a state where the first positioning holes 59 and the second positioning holes 69 are aligned with each other.

[0127] Thus, by overlapping the first plate 51 and the second plate 61 at positions where the first positioning holes 59 and the second positioning holes 69 coincide, the two-end tubular member preparation 11a, the first tubular member preparation 12a, and the second tubular member preparation 13a are arranged at appropriate positions.

[0128] At this time, each protrusion 35 is inserted into each first hole 26. Thus, each first hole 26 is engaged with each protrusion 35. By this engagement, the first tubular member preparation body 12a and the second tubular member preparation body 13a are connected. Similarly, the two-end tubular member preparation body 11a and the second tubular member preparation body 13a are connected.

[0129] In the next process of step S111 , the second hole 34 provided in the protruding portion 35 is caulked. Fig.18A , Fig.18B 3 is a diagram showing a state where the second hole 34 at the front end of the protrusion 35 is expanded by riveting. Fig.18B As shown, the caulking process for the second hole 34 is performed using an expanding punch 40. By expanding by the caulking process, the anti-dropping piece 39 is formed at the front end of the protruding portion 35. Specifically, in a state where the first tubular member preparatory body 12a and the second tubular member preparatory body 13a are connected, the front end of the expanding punch 40 is driven into the second hole 34, so that the front end of the protruding portion 35 is expanded.

[0130] Then, the retaining piece 39 is formed at the front end portion of the expanded protruding portion 35. The retaining piece 39 formed in this way is expanded so that the expanded diameter d4 is larger than the inner diameter d1 of the first hole 26.

[0131] The front end of the protruding portion 35 expanded in this way (more specifically, a portion of the front end side of the protruding portion 35 ) is formed to follow the surface of the enlarged portion 26 b .

[0132] In the next process of step S112 , the first connection portion 55 and the second connection portion 68 are cut. Fig.19 2 is a diagram showing a state after the connection portion cutting process is performed. Fig.19 As shown, in the connection portion cutting step, the first tubular member preparation 12a is cut off from the first edge 56 of the first plate 51 by cutting the first connection portion 55 of the first plate 51. In addition, the second tubular member preparation 13a is cut off from the second edge 62 of the second plate 61 by cutting the second connection portion 68 of the second plate 61.

[0133] The two-end tubular member preparation body 11a is held connected to the first edge 56 of the first plate material 51 via the two-end connecting portions 58. The connecting portion cutting step is performed by punching with a die.

[0134] Then, in the process of step S113, the first plate 51 and the second plate 61 are subjected to bending. More specifically, the first plate 51 is subjected to bending of the two-end tubular member preparation 11a and the first tubular member preparation 12a. In addition, the second tubular member preparation 13a is subjected to bending of the second plate 61. The bending is performed, for example, by punching with a die.

[0135] For example, in the bending process of the first peripheral wall preparation portion 16a of the both-end tubular member preparation body 11a and the first tubular member preparation body 12a, U-shaped bending and O-shaped bending are sequentially performed so that the second surface side of the first plate material 51 becomes the outer peripheral surface of the first tubular member 12.

[0136] In other words, the bending process is performed so that the convex portion 26c formed around the opening of the first hole 26 is directed radially inward of the first tubular member 12. The second peripheral wall preparation portion 31a of the second tubular member preparation body 13a is also subjected to the same bending process in the same bending direction as the first peripheral wall preparation portion 16a.

[0137] Fig. 20 2 is a diagram showing the state after the bending process is performed. Fig. 20 As shown, by performing bending, the first tubular member 12 is formed from the first tubular member preparation 12a, the second tubular member 13 is formed from the second tubular member preparation 13a, and the both-end tubular member 11 is formed from the both-end tubular member preparation 11a.

[0138] Furthermore, in the above description, an example is described in which the convex portion 26 c is bent toward the radial inside of the first tubular member 12 , but the convex portion 26 c may be bent toward the radial outside of the first tubular member 12 .

[0139] In addition, after the bending process (step S113), the first abutting portion 29a where the two end surfaces abut each other is formed in the first tubular member preparation 12a. Similarly, the first abutting portion 29a where the two end surfaces abut each other is formed in the two end tubular member preparation 11a. By joining a part or all of the first abutting portion 29a by laser welding or the like, the first joining portion 29 is formed along the axial direction of the first tubular member 12.

[0140] Similarly, the second abutting portion 38a where both end surfaces abut against each other is formed on the second tubular member preliminary body 13a. The second joining portion 38 is formed along the axial direction of the second tubular member 13 by joining all or part of the second abutting portion 38a.

[0141] Through these joining operations, the first tubular member 12 and the second tubular member 13 are completed.

[0142] After such bending is performed, the both-end connecting portions 58 are cut, and the both-end tubular member preliminary bodies 11 a are separated from the first edges 56 , thereby completing the bendable tube 10 .

[0143] According to such an embodiment, the bending tube 10 of the endoscope 1 includes: a first tubular member 12 having a first tongue piece 25; and a second tubular member 13 having a second tongue piece 33 superimposed on the first tongue piece 25 and having a protrusion 35 rotatably connected to the first tongue piece 25. The first tongue piece 25 of the first tubular member 12 has a first hole 26 that penetrates the first tongue piece 25 in the radial direction of the longitudinal axis O and into which the protrusion 35 is inserted. In addition, the first tongue piece 25 has a convex portion 26c formed around the first hole 26. In addition, the protrusion 35 has a second hole 34 that penetrates the protrusion 35 in the axial direction (protruding direction) of the protrusion 35. In addition, the second tongue piece 33 is provided on the second tubular member 13 in such a manner that the protrusion 26c abuts against the surface. With these configurations, the bending tube 10 of the endoscope 1 can reduce the sliding resistance between the tubular members without depending on the skills of the manufacturing operator.

[0144] That is, the bending tube 10 formed by connecting the first tubular member 12 and the second tubular member 13 has the convex portion 26c that abuts against and slides on the surface of the overlapping portion of the second tongue portion 33 when performing a bending operation. Due to the action of the convex portion 26c, the overlapping portion (the first tongue portion 25 and the second tongue portion 33) connecting the tubular members can reduce the contact area when the convex portion 26c abuts against and slides on the overlapping portion. Therefore, compared with a bending tube without the convex portion 26c, the sliding resistance between the tubular members can be reduced.

[0145] Here, when the first tubular member 12 and the second tubular member 13 are connected, the second tongue portion 33 is overlapped on the first tongue portion 25, and the protrusion 35 is inserted into the first hole 26. At this time, the convex portion 26c provided on the first tongue portion 25 is abutted against the surface of the second tongue portion 33. And the second hole 34 provided on the protrusion 35 is expanded by punching, etc. Even when a large punching load is temporarily applied during such punching, since the first tongue portion 25 and the second tongue portion 33 are abutted via the convex portion 26c, the excessive increase of the sliding resistance is also suppressed. Thus, the sliding resistance between the tubular members can be reduced independently of the skills of the manufacturing operator, etc.

[0146] Furthermore, the reduction in sliding resistance between the first tongue piece 25 and the second tongue piece 33 due to the projection 26c can make the movement of the bending tube 10 itself smoother. Therefore, the responsiveness of the insertion portion 2 of the endoscope 1 during operation can also be improved.

[0147] In addition, the convex portion 26c provided on the first tongue portion 25 is formed by press working by chamfering or the like using the chamfering punch 37 and the concave portion 41a provided on the base 41. When the chamfering is performed by such press working, the convex portion 26c is formed by deforming a part of the first plate material 51 protruding due to plastic flow to follow the shape of the concave portion 41a of the base 41. Therefore, the convex portion 26c can also form protrusions of various shapes around the first hole 26 by changing the shape of the concave portion 41a.

[0148] Figure 21 to Figure 25 The drawings show modified examples of the shape of the convex portion 26c. Each drawing shows the shape of the convex portion after the shape of the concave portion 41a of the present embodiment is changed and pressed.

[0149] Fig.21 FIG. 2 is a top view showing a modified example of the shape of the convex portion formed around the opening of the first hole. Fig.21 As shown in the figure, the first tongue piece 25 has two arc-shaped convex parts 26d of the same shape. These convex parts 26d are arranged at mutually opposite positions around the first hole 26. By forming the discontinuous convex parts 26d in this way, the contact area between the first tongue piece 25 and the second tongue piece 33 can be reduced compared with the above-mentioned annular convex parts 26c. Therefore, the convex parts 26d can further reduce the sliding resistance between the tubular members.

[0150] Fig. 22 FIG. 2 is a top view showing a modified example of the shape of the convex portion formed around the opening of the first hole. Fig. 22As shown in the figure, the first tongue piece 25 has three arc-shaped convex parts 26e of the same shape. These convex parts 26e are arranged in a ring shape at equal intervals around the first hole 26. By forming the discontinuous convex parts 26e in this way, the contact area between the first tongue piece 25 and the second tongue piece 33 can be further reduced compared with the convex parts 26d mentioned above. Therefore, the convex parts 26e can further reduce the sliding resistance between the tubular members.

[0151] Fig.23 FIG. 2 is a top view showing a modified example of the shape of the convex portion formed around the opening of the first hole. Fig.23 As shown in the figure, the first tongue piece 25 has four arc-shaped convex parts 26f of the same shape. These convex parts 26f are arranged in a ring shape at equal intervals around the first hole 26. By forming the discontinuous convex parts 26f in this way, the contact area between the first tongue piece 25 and the second tongue piece 33 can be reduced compared with the convex parts 26e mentioned above. Therefore, the convex parts 26f can further reduce the sliding resistance between the tubular members.

[0152] Fig.24 FIG. 2 is a top view showing a modified example of the shape of the convex portion formed around the opening of the first hole. Fig.24 As shown in the figure, the first tongue piece 25 has four elliptical protrusions 26g of the same shape. These protrusions 26g are arranged in a ring shape at equal intervals around the first hole 26. By forming the discontinuous protrusions 26g in this way, the contact area between the first tongue piece 25 and the second tongue piece 33 can be reduced compared with the above-mentioned protrusions 26e. Therefore, the protrusions 26g can further reduce the sliding resistance between the tubular members.

[0153] Fig.25 FIG. 2 is a top view showing a modified example of the shape of the convex portion formed around the opening of the first hole. Fig.25 As shown in the figure, the first tongue piece 25 has three elliptical protrusions 26h of the same shape. These protrusions 26h are arranged in a ring shape at equal intervals around the first hole 26. By forming the discontinuous protrusions 26h in this way, the contact area between the first tongue piece 25 and the second tongue piece 33 can be reduced compared with the above-mentioned protrusions 26e. Therefore, the protrusions 26h can further reduce the sliding resistance between the tubular members.

[0154] In addition, the convex portion 26c can be formed into various shapes by changing the thickness of the first plate 51, the tip shape of the chamfering punch 37, the pressing load and other pressing conditions. In addition, various shapes of protrusions can also be formed by combining the shape of the concave portion 41a with the above-mentioned pressing conditions.

[0155] Below, refer to Figure 26 to Figure 30Only the differences from the first embodiment will be described below, and the same components as those in the first embodiment are denoted by the same reference numerals, and the description thereof will be omitted as appropriate.

[0156] like Fig.26 As shown, the second tongue portion 33 of the present embodiment has, for example, a recessed portion 35b for receiving the annular convex portion 26c.

[0157] The concave portion 35b is formed at a position opposite to the convex portion 26c. Fig. 27 As shown, the recessed portion 35 b is formed substantially simultaneously with the second hole 34 and the protruding portion 35 during the burring process in step S107 , for example.

[0158] Specifically, the burring process in the present embodiment is performed using a punch 60 and a base 63. The base 63 has a convex portion 63a for forming the concave portion 35b.

[0159] The size of the convex portion 63a is set based on the size of the convex portion 26c. Therefore, for example, the radial width of the convex portion 63a is set to be slightly larger than the radial width of the convex portion 26c. In addition, the protruding length of the convex portion 63a is set to be slightly smaller than the protruding length of the convex portion 26c.

[0160] In addition, during the flanging process, for example, the second plate 61 is placed in a state of being positioned on the base 63. At this time, the positioning relative to the base 63 is performed using, for example, the second positioning hole 69 (see Fig.14A ). In addition, the protruding surface of the second plate 61 during the flanging process abuts against the base 63. Then, as Fig. 27 As shown in FIG. 1 , the lower hole 35 a placed on the base 63 and the second plate 61 is subjected to flanging processing using a punch 60 .

[0161] By such flanging, the second plate 61 is formed with the second hole 34 and the protrusion 35, and the concave portion 35b is formed in the same manner as the convex portion 63a (see Fig. 27 , Fig.28 ).

[0162] The convex part 26c is received in the concave part 35b formed in this way. The concave part 35b is preferably annular, but any concave part 35b may be formed to match the shape of the convex part 26c, for example, in a partial annular shape, as long as it can receive the convex part 26c.

[0163] Specifically, the second tongue portion 33 is overlapped with the first tongue portion 25, and the protrusion 35 is inserted into the first hole 26. At this time, the convex portion 26c provided in the first tongue portion 25 is accommodated in the concave portion 35b provided in the second tongue portion 33 in a state of contacting the concave portion 35b.

[0164] Then, during the riveting process in step S111, the first tubular member 12 and the second tubular member 13 are rotatably connected by expanding the front end of the protruding portion 35 (see Fig.29 ).

[0165] The other configurations are the same as those of the above-mentioned first embodiment.

[0166] According to such an embodiment, the bending tube 10 of the endoscope 1 has the recessed portion 35b for receiving the convex portion 26c in the second tongue portion 33 of the second tubular member 13. With such a configuration, in addition to the effects obtained in the above-mentioned first embodiment, the following effects can be obtained.

[0167] That is, in the bendable pipe 10 of the present embodiment, the convex portion 26 c is accommodated in the concave portion 35 b , so that the connection strength between the tubular members is improved, and the durability of the bendable pipe 10 can be improved.

[0168] In detail, the bending tube 10 in the present embodiment can suppress the increase of the distance from the surface of the second tongue piece 33 facing the first tongue piece 25 to the second surface of the first tongue piece 25 even when the convex portion 26c is formed on the first tongue piece 25. Therefore, even when the convex portion 26c is formed on the first tongue piece 25, the expanded diameter d4 can be increased without increasing the protrusion amount of the protrusion 35. Therefore, the bending tube 10 in the present embodiment can maintain the slidability between the tubular members and improve the durability of the bending operation.

[0169] In addition, the depth and width of the recessed portion 35b are set according to the height and width required by the convex portion 26c. That is, the size of the convex portion 63a during the flanging process is set based on the size required by the convex portion 26c. Thus, for example, even if the protruding amount (volume) of the convex portion 26c is increased, the convex portion 26c can be reliably accommodated by the recessed portion 35b, and the gap of the overlapping portion can be suppressed to a minimum.

[0170] Furthermore, by increasing the protruding amount (volume) of the convex portion 26c, the excess first plate 51 (see FIG. 1 ) generated by the chamfering process in step S102 can be absorbed by the convex portion 26c. Fig.30 ). Therefore, it is possible to suppress the surface deformation of the first surface of the first tongue piece 25 during the chamfering process.

[0171] That is, by setting the volume of the convex portion 26c according to the volume of the first plate 51 extruded by the chamfering process, it is possible to suppress the remaining first plate 51 from flowing to the portion other than the convex portion 26c. Therefore, the bending pipe 10 in this embodiment can suppress the surface strain of the first tongue portion 25 even when the enlarged portion 26b is formed large for the purpose of improving the connection strength by the caulking process.

[0172] In addition, the recessed portion 35b is preferably formed substantially simultaneously with the second hole 34 and the protruding portion 35 formed during the flanging process. Furthermore, when the recessed portion 35b is formed in imitation of the protruding portion 63a, for example, a portion of the second plate material 61 pressed into the protruding portion 63a flows toward the protruding portion 35. Furthermore, a portion of the second plate material 61 flowing to the protruding portion 35 is used for forming the protruding portion 35.

[0173] Thus, even if the diameter of the lower hole 35a before the burring process is increased, the length of the protruding portion 35 can be ensured. Therefore, the bent pipe 10 in the present embodiment can improve the formability when the protruding portion 35 is formed.

[0174] The invention described in the above embodiments is not limited to these aspects, and various modifications can be made in the implementation stage without departing from the scope of the invention. For example, the bendable tube 10 shown in each embodiment can also be applied to insertion devices such as catheters, stents, and treatment instruments.

[0175] Furthermore, the above-described embodiments include inventions at various stages, and various inventions can be extracted by appropriately combining a plurality of disclosed constituent elements.

[0176] Furthermore, when the described problem can be solved and the described effect can be obtained even if some components are deleted from all the components shown in the above-mentioned embodiment, the structure after deleting the components can be extracted as an invention.

[0177] This application is filed based on U.S. Provisional Application No. 63 / 404,559 filed on September 8, 2022 as a basis for claiming priority, and the above contents are cited in the specification, claims and drawings of this application.

Claims

1. A curved tube of an endoscope, characterized in that: Include: a first tubular member; and a second tubular member having an overlapping portion overlapping an end portion of the first tubular member, wherein a rotation shaft rotatably connected to the first tubular member is formed at the overlapping portion; The end portion of the first tubular member has a first hole penetrating the end portion in a radial direction of the longitudinal axis and into which the rotation shaft is inserted. A convex portion is formed around the opening of the first hole, The rotating shaft has a second hole penetrating in the axial direction of the rotating shaft. The overlapping portion is formed with a recessed portion for receiving the convex portion.

2. The bending tube of an endoscope according to claim 1, characterized in that: The outer diameter of the front end of the rotating shaft is expanded to be larger than the inner diameter of the first hole.

3. The bending tube of an endoscope according to claim 1, characterized in that: The first hole has an enlarged portion whose diameter is enlarged toward the front end of the rotating shaft. The front end of the rotating shaft is shaped to imitate the enlarged portion.

4. The bending tube of an endoscope according to claim 3, characterized in that: The enlarged portion is in the shape of a truncated cone.

5. The bending tube of an endoscope according to claim 1, characterized in that: The overlapping portion is arranged radially inward of the first tubular member relative to the end portion. The convex portion is provided on the radially inner surface of the end portion.

6. The bending tube of an endoscope according to claim 1, characterized in that: The overlapping portion is arranged radially outward of the first tubular member relative to the end portion. The convex portion is provided on the radially outer side surface of the end portion.

7. The bending tube of an endoscope according to claim 1, characterized in that: The recessed portion is formed in a ring shape.

8. The bending tube of an endoscope according to claim 7, characterized in that: The convex portion is formed in a ring shape.

9. The bending tube of an endoscope according to claim 1, characterized in that: The convex portion and the concave portion are arranged so as to abut against each other.

10. An endoscope, characterized in that: The insertion part has a bendable bending part. The bending portion includes: a first tubular member; and a second tubular member having an overlapping portion overlapping an end portion of the first tubular member, wherein a rotation shaft rotatably connected to the first tubular member is formed at the overlapping portion; The end portion of the first tubular member has a first hole penetrating the end portion in a radial direction of the longitudinal axis and into which the rotation shaft is inserted. An annular convex portion is formed around the opening of the first hole, The rotating shaft has a second hole penetrating in the axial direction of the rotating shaft. The overlapping portion has an annular recessed portion formed therein for receiving the convex portion.

11. The endoscope according to claim 10, characterized in that: The outer diameter of the front end of the rotating shaft is expanded to be larger than the inner diameter of the first hole.

12. The endoscope according to claim 10, characterized in that The first hole has an enlarged portion whose diameter is enlarged toward the front end of the rotating shaft. The front end of the rotating shaft is shaped to imitate the enlarged portion.

13. The endoscope according to claim 12, characterized in that: The enlarged portion is in the shape of a truncated cone.

14. The endoscope according to claim 10, characterized in that The overlapping portion is arranged radially inward of the first tubular member relative to the end portion. The convex portion is provided on the radially inner surface of the end portion.

15. The endoscope according to claim 10, characterized in that The overlapping portion is arranged radially outward of the first tubular member relative to the end portion. The convex portion is provided on the radially outer side surface of the end portion.

16. The endoscope according to claim 10, characterized in that The convex portion and the concave portion are arranged so as to abut against each other.

17. A method for manufacturing a curved tube of an endoscope, characterized in that: have: (a) forming a first hole having a predetermined inner diameter in a first plate; (b) forming a convex portion around the first hole on the first surface of the first plate; (c) forming a rotation shaft that can be inserted into the first hole in the second plate material, and forming a second hole that penetrates the rotation shaft in the axial direction; (d) forming a concave portion around the rotating shaft to receive the convex portion; (e) inserting the rotation shaft into the first hole from the first surface side so that the convex portion and the concave portion face each other; (f) a step of expanding the inner diameter of the second hole in the front end portion of the rotating shaft so that the outer diameter of the front end portion is larger than the predetermined inner diameter; and (g) A step of bending the first plate and the second plate to join both ends of the first plate and the second plate to form the respective plates into a tubular member.

18. The method for manufacturing a bendable tube of an endoscope according to claim 17, characterized in that: After performing the steps (a) to (d), the step (e) is performed, The step (f) is performed after the step (e).

19. The method for manufacturing a bendable tube of an endoscope according to claim 17, characterized in that: In the step (g), the tubular member is bent so that the convex portion faces radially inward.

20. The method for manufacturing a bendable tube of an endoscope according to claim 17, characterized in that: In the step (g), the tubular member is bent so that the convex portion faces radially outward.

21. The method for manufacturing a bendable tube of an endoscope according to claim 17, characterized in that: The periphery of the opening of the first hole is chamfered by punching. In the step (b), the convex portion and the chamfer are formed simultaneously.

22. The method for manufacturing a bendable tube of an endoscope according to claim 17, characterized in that: In the step (c), the second hole is formed into a cylindrical shape by burring.

23. The method for manufacturing a curved tube of an endoscope according to claim 22, characterized in that: The step (c) and the step (d) are simultaneously performed by the flanging process.

24. A curved tube for insertion equipment, characterized in that Include: a first tubular member; and a second tubular member having an overlapping portion overlapping an end portion of the first tubular member, wherein a rotation shaft rotatably connected to the first tubular member is formed at the overlapping portion; The end portion of the first tubular member has a first hole penetrating the end portion in a radial direction of the longitudinal axis and into which the rotation shaft is inserted. A convex portion is formed around the opening of the first hole, The rotating shaft has a second hole penetrating in the axial direction of the rotating shaft. The overlapping portion is formed with a recessed portion for receiving the convex portion.

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