Endoscope

Abstract

An adverse situation caused by bending of a connection portion between an active bending portion and a passive bending portion is prevented. In an endoscope provided with an active bending portion and a passive bending portion which are sequentially arranged from a distal end and a connection cylinder (50) which connects the active bending portion and the passive bending portion, the active bending portion and the passive bending portion each include a plurality of joint cylinders (30, 40), a coil member (60) which passes through an operation wire (90) for bending operation of the active bending portion is fixed to the connection cylinder (50), and a notch (43) for improving the rotational freedom of a joint cylinder (40A) of the passive bending portion which is connected to and rotates with the connection cylinder (50) is formed in the vicinity of the coil member (60).

Description

Technical Field

[0001] The present invention relates to an endoscope having a flexible first bend and a flexible second bend.

[0002] This application claims priority based on Japanese Application No. 2020-160963, filed on September 25, 2020, and incorporates all disclosures set forth in that Japanese application. Background Technology

[0003] Previously, endoscopes with an active bending section (first bending section) and a passive bending section (second bending section) sequentially arranged from the front end of the insertion part into the body cavity have been widely used.

[0004] For example, Patent Document 1 discloses an endoscope configured to cause a slow curvature change in the insertion portion by setting the curvature value during bending to decrease from the active bending portion toward the passive bending portion.

[0005] Furthermore, Patent Document 2 discloses an endoscope that allows the active bending section and the passive bending section to bend in four directions respectively by the user operating the operating section.

[0006] Existing technical documents

[0007] Patent documents

[0008] Patent Document 1: Japanese Patent Application Publication No. 2006-218231

[0009] Patent Document 2: Japanese Patent Application Publication No. 2013-202304 Summary of the Invention

[0010] The problem that the invention aims to solve

[0011] The active bending section and the passive bending section each include multiple articulated cylinders connected by a connecting cylinder. Furthermore, a coil component through which the wire used for bending the active bending section passes is fixed to the connecting cylinder, for example, by welding. Because the coil component has excellent deformability and resilience, it does not hinder the bending and recovery of the connection between the active bending section and the passive bending section.

[0012] On the other hand, as described above, when the coil component is fixed by welding, the deformation of the coil component in the welded part is restricted. Therefore, when interference occurs between the joint cylinder of the active bending part or the passive bending part and the coil component, it will hinder the bending and recovery of the connection of the active bending part or the passive bending part.

[0013] However, the endoscopes in Patent Documents 1 and 2 did not address this issue and could not be resolved.

[0014] The present invention was made in view of the following circumstances, and its object is to provide an endoscope that can prevent adverse conditions caused by bending of the connection between the active bending portion and the passive bending portion, even when the coil component is fixed and the deformation of the coil component is restricted.

[0015] Technical solutions for solving the problem

[0016] The endoscope of the present invention comprises an endoscope having a flexible first bending portion and a flexible second bending portion arranged sequentially from the front end and a connecting cylinder connecting the first bending portion and the second bending portion. The first bending portion and the second bending portion each include a plurality of articulated cylinders. A coil component for inserting a metal wire for bending the first bending portion is fixed on the connecting cylinder. A notch for improving the rotational freedom of a predetermined articulated cylinder of the second bending portion, which is connected to and rotates with the connecting cylinder, is formed near the coil component.

[0017] In this invention, the notch is formed near the coil component in the predetermined joint cylinder or the connecting cylinder. Such a notch can eliminate interference between the coil component and the predetermined joint cylinder, or can suppress the situation where the rotation of the predetermined joint cylinder is blocked by the coil component, thereby increasing the rotational freedom of the predetermined joint cylinder.

[0018] Invention Effects

[0019] According to the present invention, even when the coil component is fixed and the deformation of the coil component is restricted, adverse conditions caused by bending of the connection between the active bending portion and the passive bending portion can be prevented. Attached Figure Description

[0020] Figure 1 This is an external view of the endoscope according to Embodiment 1 of the present invention.

[0021] Figure 2 It is a cross-sectional view of the active bending section and the passive bending section along the axial direction of the insertion section.

[0022] Figure 3 It is a cross-sectional view showing the joint cylinder, the connecting cylinder, and the connection state of the joint cylinder.

[0023] Figure 4 It is a three-dimensional drawing showing the appearance of the joint cylinder.

[0024] Figure 5This is a cross-sectional view showing the articulated cylinder, connecting cylinder, and connection state of the articulated cylinder of the endoscope according to Embodiment 2.

[0025] Figure 6 This is a cross-sectional view showing the articulated cylinder, connecting cylinder, and connection state of the articulated cylinder of the endoscope according to Embodiment 3.

[0026] Figure 7 This is a cross-sectional view showing the articulated cylinder, connecting cylinder, and connection state of the articulated cylinder of the endoscope according to Embodiment 4.

[0027] Figure 8 yes Figure 7 Cross-sectional view of line VIII-VIII in the middle.

[0028] Figure 9 This is a cross-sectional view showing the articulated cylinder, connecting cylinder, and connection state of the articulated cylinder of the endoscope according to Embodiment 5. Detailed Implementation

[0029] The endoscope according to the embodiments of the present invention will now be described in detail with reference to the accompanying drawings.

[0030] (Implementation Method 1)

[0031] Figure 1 This is an external view of the endoscope 10 according to Embodiment 1 of the present invention. The endoscope 10 of this embodiment includes: an insertion part 14, which has a camera device and is inserted into the body cavity of the subject; an operation part 20, which is used to operate the insertion part 14; and a connector part 24, which is connected to a processor, a light source device, and an air and water supply device (not shown).

[0032] The insertion part 14 is connected to the operation part 20 via the bending part 16, and the operation part 20 is connected to the connector part 24 via the universal flexible cable 25.

[0033] The general-purpose flexible cord 25 is flexible and includes: an electrical wire for transmitting electrical signals from the insertion part 14 to the connector part 24; a water passage for circulating water supplied from the connector part 24; and an air passage for circulating air.

[0034] The operating unit 20 includes a grip 205, a button 201 for receiving instructions from the user such as water or gas supply, and a bending knob 21 for operating the bending of the active bending unit 9 (described later).

[0035] The gripping part 205 has a generally cylindrical shape and tapers towards the insertion part 14. A channel inlet 22 for inserting surgical instruments or the like is provided on the gripping part 205 near the insertion part 14.

[0036] The insertion part 14 has a narrow cylindrical shape and is configured to be flexible. The insertion part 14 has, in sequence from the front end side, a front end 13, an active bending part 9 (first bending part), a passive bending part 8 (second bending part) and a flexible part 11.

[0037] The front end portion 13 has a camera unit (not shown), which includes a camera device such as a CCD (Charge Coupled Device) or CMOS (Complementary Metal Oxide Semiconductor), a circuit board for driving the camera device, and an observation optical system. Furthermore, the front end portion 13 has an illumination unit (not shown), which includes an illumination optical system for illuminating the observed part within the body cavity.

[0038] The active bending section 9 can be bent actively. That is, the active bending section 9 bends in four directions according to the operation of the bending knob 21. On the other hand, the passive bending section 8 bends passively. That is, the passive bending section 8 bends in any one of the four directions through contact with the subject. The flexible section 11 is flexible and can be bent.

[0039] Figure 2 This is a cross-sectional view of the active bending portion 9 and the passive bending portion 8 along the axial direction of the insertion portion 14. Specifically, Figure 2 The boundary portion between the active bending portion 9 and the passive bending portion 8 is shown.

[0040] The active bending section 9 has multiple articulated cylinders 30. The multiple articulated cylinders 30 are connected side by side. Each articulated cylinder 30 has a generally cylindrical shape and is pivotally connected to adjacent articulated cylinders 30 in a manner that allows it to rotate up, down, left, and right.

[0041] Furthermore, each joint cylinder 30 is provided with a pair of bearings 31 on one axial end for supporting a rotating shaft, and a pair of bearings 32 on the other axial end for supporting another rotating shaft orthogonal to the one rotating shaft. The pair of bearings 31 and the pair of bearings 32 are in the shape of a generally circular plate with a through hole in the center, and are arranged to extend along the axial direction of the joint cylinder 30.

[0042] Multiple articulated cylinders 30 are connected side by side so that the pair of bearings 31 and the pair of bearings 32 are positioned alternately.

[0043] The passive bending section 8 has multiple articulated cylinders 40. The multiple articulated cylinders 40 are connected side by side. Each articulated cylinder 40 has a generally cylindrical shape and is pivotally connected to adjacent articulated cylinders 40 in a manner that allows it to rotate up, down, left, and right.

[0044] Furthermore, each articulated cylinder 40 has a pair of bearings 41 at one axial end for supporting a rotating shaft, and a pair of bearings 42 at the other axial end for supporting another rotating shaft orthogonal to the first rotating shaft. The pair of bearings 41 and 42 are generally circular plates with a through hole in the center, circumferentially offset from the pair of bearings 31 and 32, and extend axially along the articulated cylinder 40. Multiple articulated cylinders 40 are connected side-by-side such that the pair of bearings 41 and 42 are alternately positioned.

[0045] Four operating lines 90 for bending the active bending section 9 are inserted inside the flexible section 11, the active bending section 9, and the passive bending section 8. One end of each operating line 90 is fixed to the front end 13 of the active bending section 9, and the other end is connected to the bending knob 21 of the operating section 20. The outer sides of the multiple articulated cylinders 30 and 40 are covered with bending rubber.

[0046] A connecting cylinder 50 is sandwiched between the active bending portion 9 and the passive bending portion 8. That is, the joint cylinder 30 closest to the passive bending portion 8 among the plurality of joint cylinders 30 of the active bending portion 9 (hereinafter referred to as joint cylinder 30A) and the joint cylinder 40 closest to the active bending portion 9 among the plurality of joint cylinders 40 of the passive bending portion 8 (hereinafter referred to as joint cylinder 40A) are connected via the connecting cylinder 50.

[0047] Figure 3 It is a cross-sectional view showing the connection state of the joint cylinder 30A, the connecting cylinder 50 and the joint cylinder 40A (the predetermined joint cylinder). Figure 3 Shown in magnified form Figure 2 The part enclosed by a dashed circle.

[0048] Four wire guides 33 are provided at four locations on the inner circumferential surface of the joint cylinder 30A to hold the operating line 90. Through holes 34 are formed at four locations on the joint cylinder 30A to secure the wire guides 33, allowing them to pass through the joint cylinder 30A internally and externally. The through holes 34 are evenly spaced along the circumference of the joint cylinder 30A. Each wire guide 33 engages with a through hole 34.

[0049] The wire guide 33 includes an annular retaining portion 331 and a cylindrical fitting portion 332 extending radially outward along the retaining portion 331. The fitting portion 332 is fitted into a through hole 34, and the operating line 90 is inserted into the retaining portion 331.

[0050] Two of the four wire guides 33, which are opposite to each other, are positioned near a pair of bearings 31.

[0051] The connecting cylinder 50 is generally cylindrical in shape, and a pair of bearings 51, pivotally connected to a pair of bearings 31 of the joint cylinder 30A, are provided at one end of the connecting cylinder 50 along the axial direction. The pair of bearings 51 are generally circular plates with a through hole in the center. In the connecting cylinder 50, the axial dimension is smaller the further away from the pair of bearings 51 in the circumferential direction.

[0052] Furthermore, coil components 60 for guiding the operating line 90 are provided at four locations on the inner circumferential surface of the connecting cylinder 50. The coil components 60 are arranged at equal intervals along the circumference of the connecting cylinder 50. For example, the coil components 60 are fixed to the inner circumferential surface of the connecting cylinder 50 by welding. That is, a welded portion 53 is sandwiched between the coil components 60 and the connecting cylinder 50.

[0053] Each coil component 60 is tubular and tightly wound with coil wire. Each coil component 60 extends axially along the connecting cylinder 50, with one end of the coil component 60 extending from the other end of the connecting cylinder 50 to the inside of the joint cylinder 40A. An operating line 90 is inserted into the coil component 60.

[0054] Furthermore, at the other end of the joint cylinder 40A, a pair of bearings 52, pivotally connected to a pair of bearings 41 of the joint cylinder 40A, are provided along the axial extension of the connecting cylinder 50. The pair of bearings 52 are in the shape of circular plates with a through hole in the center. The pair of bearings 52 are disposed between adjacent coil components 60.

[0055] Figure 4 This is a three-dimensional view showing the appearance of the joint cylinder 40A.

[0056] The articulated cylinder 40A is generally cylindrical in shape, and the pair of bearings 41 are provided at one end on the side of the connecting cylinder 50, and are pivotally connected to the pair of bearings 52 of the connecting cylinder 50. Therefore, the articulated cylinder 40A rotates about an axis through which the pair of bearings 41 pass.

[0057] The bearing 41 is flat and includes a semi-circular protrusion 412 and a semi-circular base 413 with a diameter larger than the protrusion 412, and a through hole 411 is formed in the center. The bearing 41 is positioned slightly towards the axis from the outer peripheral surface of the joint cylinder 40A, and a guide step 414 is formed between the base 413 and the outer peripheral surface of the joint cylinder 40A. The height of the guide step 414 decreases as it approaches the end of the joint cylinder 40A.

[0058] As described above, since the bearing 41 is positioned slightly closer to the axis than the outer peripheral surface of the joint cylinder 40A, the base 413 protrudes slightly towards the axis than the inner peripheral surface of the joint cylinder 40A. Consequently, a step (not shown) identical to the guide step 414 is also formed between the base 413 and the inner peripheral surface of the joint cylinder 40A.

[0059] Furthermore, four notches 43 (first notches) are formed at one end of the joint cylinder 40A to improve the rotational freedom of the joint cylinder 40A. Each notch 43 has, for example, a semi-circular shape larger than the diameter of the coil component 60.

[0060] Notches 43 are formed by spacing two intervals between each pair of bearings 41. When the joint cylinder 40A is connected to the connecting cylinder 50, each notch 43 is configured to be located near the coil component 60 of the connecting cylinder 50. Specifically, the notches 43 are formed at positions on the circumference of the joint cylinder 40A corresponding to the coil component 60 (welding portion 53).

[0061] Furthermore, as described above, a pair of bearings 42 are provided at the other end of the joint cylinder 40A. The bearing 42 is flat and includes a semi-circular protrusion 422 and a semi-circular base 423 with a diameter larger than the protrusion 422, and a through hole 421 is formed in the center. The bearing 42 is positioned slightly radially outward from the outer peripheral surface of the joint cylinder 40A, and a step 424 is formed between the base 423 and the outer peripheral surface of the joint cylinder 40A. The height of the step 424 increases as it approaches the other end of the joint cylinder 40A.

[0062] Thus, since the bearing 42 is positioned slightly radially outward from the outer circumferential surface of the joint cylinder 40A, the base 423 is positioned slightly outward from the inner circumferential surface of the joint cylinder 40A. Consequently, a step (not shown) identical to the step 424 is also formed between the base 423 and the inner circumferential surface of the joint cylinder 40A.

[0063] When the articulated cylinder 40A is connected to the connecting cylinder 50, the bearing 52 of the connecting cylinder 50 is guided by the guide step 414 of the articulated cylinder 40A and is rotatably pivotally connected to the bearing 41 on the same axis. Furthermore, when the articulated cylinder 40A is connected to an adjacent articulated cylinder 40, the bearing 42 of the articulated cylinder 40A is rotatably pivotally connected to the bearing of the adjacent articulated cylinder 40.

[0064] As described above, the coil component 60 is fixed to the inner circumferential surface of the connecting cylinder 50 by welding. Therefore, in the coil component 60, the welded portion cannot deform, and the freely deformable portion is restricted to the end on the side of the articulated cylinder 40A, significantly reducing the degree of freedom of deformation of the coil component 60. Consequently, the articulated cylinder 40A, which is pivotally connected to and rotates on the connecting cylinder 50, may be hindered from rotating due to interference between it and the coil component 60 (the welded portion).

[0065] In contrast, as described above, the endoscope 10 of Embodiment 1 has a notch 43 formed in the articulated cylinder 40A near the coil member 60 connecting the cylinder 50, and at a position in the circumferential direction of the articulated cylinder 40A corresponding to the coil member 60. Therefore, when the articulated cylinder 40A rotates, interference between the articulated cylinder 40A and the coil member 60 can be reliably prevented.

[0066] Therefore, in the endoscope 10 of Embodiment 1, while using the naturally long coil member 60 to reliably guide the operating line 90, it is possible to prevent bending and poor recovery caused by the connection between the active bending part 9 and the passive bending part 8.

[0067] The above explanation uses the case where the notch 43 is semi-circular as an example, but it is not limited to this. For example, it can also be rectangular.

[0068] Furthermore, the above description uses the case where four notches 43 are formed at one end of the joint cylinder 40A as an example, but it is not limited to this. The number of notches 43 can be five or more, or three or fewer.

[0069] Furthermore, the above explanation uses the case where all four gaps 43 are of the same shape as an example, but it is not limited to this and can also be configured with different shapes and sizes.

[0070] Furthermore, in the above description, the example given is that when a coil member 60 is formed on the connection between the active bending portion 9 and the passive bending portion 8, a notch 43 is provided to prevent interference with the coil member 60. However, this is not a limitation. For example, it can also be applied to the case where a coil member 60 is formed on the connection between the passive bending portion 8 and the flexible portion 11.

[0071] (Implementation Method 2)

[0072] Figure 5 This is a cross-sectional view showing the connection state of the articulated cylinder 30A, connecting cylinder 50, and articulated cylinder 40A of the endoscope 10 according to Embodiment 2. Similar to the endoscope 10 of Embodiment 1, the articulated cylinder 40A is pivotally connected to the connecting cylinder 50, and the articulated cylinder 30A is also pivotally connected to the connecting cylinder 50. Furthermore, the coil component 60 is welded to the inner circumferential surface of the connecting cylinder 50, and the coil component 60 extends to the inner side of the articulated cylinder 40A.

[0073] In the endoscope 10 of Embodiment 2, four notches 54 (second notches) are formed at the other end of the connecting cylinder 50 on the side of the joint cylinder 40A to improve the rotational freedom of the joint cylinder 40A. Each notch 54 is, for example, a chamfered rectangle, and the circumferential dimension of the connecting cylinder 50 is larger than the diameter of the coil member 60. The notches 54 are formed at equal intervals in the circumferential direction of the connecting cylinder 50.

[0074] Each notch 54 is disposed near the coil component 60. Specifically, the notch 54 is formed from the other end of the joint cylinder 40A side along the axial direction of the connecting cylinder 50 at a position corresponding to the coil component 60 in the circumferential direction of the connecting cylinder 50.

[0075] As described above, since the coil component 60 is fixed to the inner circumferential surface of the connecting cylinder 50 by welding, the welded portion of the coil component 60 will not deform. Therefore, interference may occur between the coil component 60 and the connecting cylinder 40A, thus hindering the rotation of the articulated cylinder 40A.

[0076] In contrast, as described above, the endoscope 10 of Embodiment 2 has a notch 54 formed in the connecting cylinder 50 at a position corresponding to the coil member 60 in the circumferential direction of the connecting cylinder 50. Therefore, the portion of the coil member 60 that is restricted from deformation due to welding is reduced. Furthermore, a larger interval can be ensured from the side edge 541 of the joint cylinder 30A at the notch 54 to the joint cylinder 40A. Therefore, the joint cylinder 40A does not interfere with the welded portion of the coil member 60 when rotating, and can rotate without being obstructed by the coil member 60.

[0077] Therefore, in the endoscope 10 of Embodiment 2, while using the naturally long coil member 60 to reliably guide the operating line 90, it is possible to prevent bending and poor recovery caused by the connection between the active bending part 9 and the passive bending part 8.

[0078] The above explanation uses the case where the gap 54 is a rectangle as an example, but it is not limited to this. For example, it can also be a semi-circular shape.

[0079] For parts that are the same as in Embodiment 1, the same reference numerals are used and their detailed descriptions are omitted.

[0080] (Implementation Method 3)

[0081] Figure 6This is a cross-sectional view showing the connection state of the articulated cylinder 30A, connecting cylinder 50, and articulated cylinder 40A of the endoscope 10 according to Embodiment 3. Similar to the endoscope 10 of Embodiment 1, the articulated cylinder 40A is pivotally connected to the connecting cylinder 50, and the articulated cylinder 30A is also pivotally connected to the connecting cylinder 50. Furthermore, the coil component 60 is welded to the inner circumferential surface of the connecting cylinder 50, and the coil component 60 extends to the inner side of the articulated cylinder 40A.

[0082] In the endoscope 10 of Embodiment 3, four notches 54 (second notches) are formed at the other end of the connecting cylinder 50 on the side of the joint cylinder 40A to improve the rotational freedom of the joint cylinder 40A. Each notch 54 is, for example, rectangular. The notches 54 have already been described in Embodiment 2, so a detailed description of them will be omitted.

[0083] Furthermore, four notches 43 (first notches) are formed at one end of the joint cylinder 40A on the side of the connecting cylinder 50 to improve the rotational freedom of the joint cylinder 40A. Each notch 43 has, for example, a semi-circular shape. The notches 43 have already been described in Embodiment 1, so a detailed description of them will be omitted.

[0084] As described above, since the coil component 60 is fixed to the inner circumferential surface of the connecting cylinder 50 by welding, the welded portion of the coil component 60 will not deform. Therefore, interference may occur between the welded portion of the coil component 60 and the joint cylinder 40A, thus hindering the rotation of the joint cylinder 40A.

[0085] In contrast, as described above, the endoscope 10 of Embodiment 3 has a notch 54 formed in the connecting cylinder 50 at a position corresponding to the coil member 60 in the circumferential direction. Furthermore, in the articulated cylinder 40A, a notch 43 is formed at a position corresponding to the coil member 60 in the circumferential direction.

[0086] Therefore, the joint cylinder 40A will not interfere with the welded portion of the coil component 60, and can rotate without being obstructed by the coil component 60. Thus, in the endoscope 10 of Embodiment 3, while using the naturally long coil component 60 to reliably guide the operating line 90, it is possible to prevent bending and poor recovery caused by the connection between the active bending portion 9 and the passive bending portion 8.

[0087] For parts that are the same as in Embodiment 1, the same reference numerals are used and their detailed descriptions are omitted.

[0088] (Implementation Method 4)

[0089] Figure 7 This is a cross-sectional view showing the connection state of the articulated cylinder 30A, the connecting cylinder 50, and the articulated cylinder 40A of the endoscope 10 in Embodiment 4. Figure 8 yes Figure 7 Cross-sectional view of line VIII-VIII. Similar to the endoscope 10 of Embodiment 1, the articulated cylinder 40A is pivotally connected to the connecting cylinder 50, and the articulated cylinder 30A is also pivotally connected to the connecting cylinder 50.

[0090] The endoscope 10 of embodiment 4 includes a fixing ring 55 for fixing the coil component 60. The fixing ring 55 has a cylindrical shape, and the axial dimension of the fixing ring 55 is smaller than the axial dimension of the connecting cylinder 50. Furthermore, the outer diameter of the fixing ring 55 is slightly smaller than the inner diameter of the connecting cylinder 50, and it is fitted into the connecting cylinder 50. For example, the fixing ring 55 is screwed onto the connecting cylinder 50 by a screw 56.

[0091] Coil components 60 are provided at four locations on the inner circumferential surface of the fixing ring 55. The coil components 60 are evenly spaced along the circumference of the fixing ring 55. For example, the coil components 60 are soldered to the inner circumferential surface of the fixing ring 55. That is, as... Figure 8 As shown, the welding part 53 is sandwiched between the coil component 60 and the fixing ring 55, and the outer circumferential surface of the fixing ring 55 is covered by the connecting cylinder 50. The operating line 90 is inserted into the coil component 60.

[0092] In the endoscope 10 of Embodiment 4, four notches 43 (first notches) are formed at one end of the articulated cylinder 40A on the side of the connecting cylinder 50 to improve the rotational freedom of the articulated cylinder 40A. Each notch 43 has, for example, a semi-circular shape. The notches 43 have already been described in Embodiment 1, so a detailed description of them will be omitted.

[0093] As described above, since the coil component 60 is fixed to the inner circumferential surface of the fixing ring 55 by welding, the welded portion of the coil component 60 will not deform. Therefore, interference may occur between the welded portion of the coil component 60 and the joint cylinder 40A, thus hindering the rotation of the joint cylinder 40A.

[0094] In contrast, in the endoscope 10 of Embodiment 4, a notch 43 is formed in the articulated cylinder 40A at a position corresponding to the coil member 60 in the circumferential direction. Therefore, the articulated cylinder 40A does not interfere with the welded portion of the coil member 60 and can rotate without being obstructed by the coil member 60. Thus, in the endoscope 10 of Embodiment 4, while using the naturally long coil member 60 to reliably guide the operating line 90, it is possible to prevent bending and poor recovery caused by the connection between the active bending portion 9 and the passive bending portion 8.

[0095] For parts that are the same as in Embodiment 1, the same reference numerals are used and their detailed descriptions are omitted.

[0096] (Implementation Method 5)

[0097] Figure 9 This is a cross-sectional view showing the connection state of the articulated cylinder 30A, connecting cylinder 50, and articulated cylinder 40A of the endoscope 10 in Embodiment 5. Similar to the endoscope 10 in Embodiment 1, the articulated cylinder 40A is pivotally connected to the connecting cylinder 50, and the articulated cylinder 30A is also pivotally connected to the connecting cylinder 50. Furthermore, similar to Embodiment 4, it includes a fixing ring 55, and the coil component 60 is welded to the inner circumferential surface of the fixing ring 55.

[0098] In the endoscope 10 of Embodiment 5, four notches 54 (second notches) are formed at the other end of the connecting cylinder 50 on the side of the joint cylinder 40A to improve the rotational freedom of the joint cylinder 40A. Each notch 54 is, for example, rectangular. The notches 54 have already been described in Embodiment 2, so a detailed description of them will be omitted.

[0099] Furthermore, four notches 43 (first notches) are formed at one end of the joint cylinder 40A on the side of the connecting cylinder 50 to improve the rotational freedom of the joint cylinder 40A. Each notch 43 has, for example, a semi-circular shape. The notches 43 have already been described in Embodiment 1, so a detailed description of them will be omitted.

[0100] As described above, since the coil component 60 is welded to the inner circumferential surface of the fixing ring 55, the welded portion of the coil component 60 will not deform. Therefore, interference may occur between the welded portion of the coil component 60 and the joint cylinder 40A, thus hindering the rotation of the joint cylinder 40A.

[0101] In contrast, the endoscope 10 of Embodiment 5 has a notch 54 formed on the connecting cylinder 50 and a notch 43 formed on the articulated cylinder 40A. Therefore, the articulated cylinder 40A does not interfere with the welded portion of the coil component 60 and can rotate without being obstructed by the coil component 60. Thus, in the endoscope 10 of Embodiment 5, while using the naturally long coil component 60 to reliably guide the operating line 90, it is possible to prevent bending and poor recovery caused by the connection between the active bending portion 9 and the passive bending portion 8.

[0102] For parts that are the same as in Embodiment 1, the same reference numerals are used and their detailed descriptions are omitted.

[0103] The technical features (structural requirements) described in embodiments 1 to 5 can be combined with each other, and new technical features can be formed by combining them.

[0104] It should be understood that the embodiments disclosed herein are illustrative in all respects and not restrictive. The scope of the invention is not as defined above, but as shown by the claims, and is intended to include all modifications within the meaning and scope of the claims.

[0105] Symbol Explanation

[0106] 8 Passive bending section

[0107] 9. Active bending section

[0108] 10. Endoscope

[0109] 13. Front end

[0110] 14 Insertion section

[0111] 30, 30A, 40, 40A Jointed Cylinders

[0112] 43 Gap

[0113] 50 Connecting cylinder

[0114] 54 Gap

[0115] 60 Coil Components

[0116] 90 Operation Line.

Claims

1. An endoscope, characterized in that: In an endoscope having a connecting cylinder with a first bend and a second bend arranged sequentially from the front end and connecting the first bend and the second bend, The first curved portion and the second curved portion each include multiple articulated cylinders. A coil component is fixed on the connecting cylinder, through which a metal wire is inserted for bending the first bent portion. A pair of bearings are provided along the axial extension of the connecting cylinder, pivotally connected to the predetermined joint cylinder of the second bend, and the pair of bearings are disposed between adjacent coil components. A notch is formed at a position corresponding to the coil component to increase the rotational freedom of the predetermined joint cylinder of the second curved portion, which is connected to and rotates with the connecting cylinder. The coil component is fixed to the inner circumferential surface of the connecting cylinder and extends axially along the connecting cylinder. The notch includes a second notch, which is formed on the edge of the predetermined joint cylinder side of the connecting cylinder at a position corresponding to the coil component.

2. The endoscope according to claim 1, characterized in that: The notch includes a first notch, which is formed on the edge of the connecting cylinder side of the predetermined joint cylinder at a position corresponding to the coil component.

3. The endoscope according to claim 2, characterized in that: The first notch is a semicircle with a diameter larger than that of the coil component.

4. The endoscope according to claim 1, characterized in that: The second notch has a chamfered rectangular shape with a dimension in the circumferential direction of the connecting cylinder that is longer than the diameter of the coil component.

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