Endoscope and bending part thereof

Abstract

The invention provides an endoscope and a bending part thereof, and relates to the technical field of endoscopes. The bending part comprises a plurality of snake bone units which are connected end to end in the length direction of the bending part and are sequentially arranged, each snake bone unit comprises a snake bone body, a male connector and a female connector, the male connectors and the female connectors are arranged at the two ends of the snake bone bodies respectively in the length direction, and the male connector of one snake bone unit is rotationally connected with the female connector of the other adjacent snake bone unit; the male connector is provided with a first conical surface, the female connector is provided with a second conical surface, the first conical surface is matched with the second conical surface, and on a first section, perpendicular to the length direction of the bent part, of the bent part, the extension line of the first conical surface and the second conical surface does not intersect with the center of the first section. Due to the fact that the two matching faces do not intersect with the center of the cross section on the cross section perpendicular to the length direction, the radial interference magnitude of the two matching faces is increased, the lateral anti-bending strength of the bending part can be improved, the phenomenon of lateral disjunction of the bending part is avoided, and the service life of the bending part is prolonged.

Description

Technical Field

[0001] The present application relates to the technical field of endoscopes, and more specifically to an endoscope and a bending portion thereof. Background Art

[0002] Endoscopes are widely used in minimally invasive or non-invasive medical surgeries and have become an indispensable part of modern medicine. Endoscopes are composed of a head, a curved part, an insertion part, and an operating part. The snake bone of the curved part is manipulated to bend and turn to enter the target part of the human body. Therefore, the snake bone assembly is an important component of the curved part of the endoscope, and its structure is directly related to the safety and effectiveness of the endoscope.

[0003] At present, there are two main types of metal snake bone structures: the first is the riveted structure metal snake bone, in which ear plates are set at both ends of the snake bone unit, and through holes are opened in the ear plates. Adjacent snake bone units are riveted together by rivets, and the rivets are used as the rotation axis to make the adjacent snake bone units rotate relative to each other. Its assembly and manufacturing process is relatively complicated, the production cost is high, and the internal space is small under the same outer diameter. The second is the integrated cutting metal snake bone, which is made by cutting a stainless steel tube centripetally as a whole, generally including a male joint and a female joint. The male joint includes an arc part and the central angle of the circle is greater than 180°. The female joint is provided with a recessed part that matches the male joint. The male joint rotates relative to the female joint, so that the snake bone tube is bent and changed. The process is simple, the production efficiency is high, and the cost is low. Compared with the riveted structure, the integrated cutting metal snake bone has no ear plates, the internal space will not be occupied, and the outer diameter of the endoscope can be effectively reduced. Therefore, considering the cost, endoscope size and other factors, the integrated cutting metal snake bone is widely used. However, this type of snake-bone structure often ensures its lateral strength through the interference fit of the mating surfaces of the male connector and the female connector. When the wall thickness of the pipe is limited, the radial interference fit of the mating surfaces of the male connector and the female connector is limited. Therefore, the strength perpendicular to the bending direction is poor, and lateral disjointment is likely to occur between single snake-bone units. This poses certain risks, especially in clinical application scenarios where instrument clamping is frequently used. Summary of the invention

[0004] The present application provides an endoscope and a bending portion thereof, which can effectively improve the lateral bending strength of the bending portion to solve the problem of lateral disjointness.

[0005] The present application provides an endoscope bending portion, comprising a plurality of snake bone units arranged in sequence end to end along the length direction thereof;

[0006] The snake bone unit comprises a snake bone body, a male joint and a female joint, wherein the male joint and the female joint are respectively arranged at two ends of the snake bone body along the length direction;

[0007] The male joint of one of the snake-bone units is rotatably connected to the female joint of another adjacent snake-bone unit; the male joint is provided with a first conical surface, the female joint is provided with a second conical surface, and the first conical surface and the second conical surface cooperate with each other;

[0008] The bent portion has a first cross section in a direction perpendicular to the length thereof, and in the first cross section, an extension line of the first tapered surface and the second tapered surface does not intersect with a center of the first cross section.

[0009] In some optional embodiments, the male connector and the female connector cooperate with each other to form a rotating portion, and the bent portion has a second cross-section perpendicular to its width direction and passing through the central axis of the rotating portion, and on the second cross-section, the extension lines of the first conical surface and the second conical surface form an angle θ1 with the central axis of the rotating portion.

[0010] In some optional embodiments, the angle θ1 is greater than 0°.

[0011] In some optional embodiments, there is a gap between the first conical surface and the second conical surface, so that the first conical surface and the second conical surface can rotate around the central axis of the rotating part.

[0012] In some optional embodiments, the male connector includes a first protrusion protruding relative to the snake bone body, and the female connector includes a first recessed portion recessed relative to the snake bone body; the first conical surface is formed on the outer peripheral wall of the first protrusion, and the second conical surface is formed on the inner peripheral wall of the first recessed portion.

[0013] In some optional embodiments, the first conical surface includes a plurality of first conical portions that are spaced apart or continuously, and the plurality of first conical portions are arranged around the outer peripheral wall of the first protruding portion; the second conical surface includes a plurality of second conical portions that are spaced apart or continuously, and the plurality of second conical portions are arranged around the inner peripheral wall of the first recessed portion.

[0014] In some optional embodiments, the male connector also includes a second recessed portion arranged on both sides of the first protrusion, and the female connector also includes a second protrusion arranged on both sides of the first recessed portion, and the second protrusion and the snake bone body are combined to form the first recessed portion; a third conical surface is provided on the inner circumferential wall of the second recessed portion, and a fourth conical surface is provided on the outer circumferential wall of the second protrusion, and the third conical surface and the fourth conical surface cooperate with each other; on the first section, the extension lines of the third conical surface and the fourth conical surface do not intersect with the center of the first section; there is a gap between the third conical surface and the fourth conical surface, so that the third conical surface and the fourth conical surface can rotate around the central axis of the rotating part.

[0015] In some optional embodiments, the protruding directions of the first protrusion and the second protrusion relative to the serpentine body and the recessed directions of the first recessed portion and the second recessed portion relative to the serpentine body both form an angle greater than 0° with the central axis of the serpentine unit, and on the second section, the extension lines of the third conical surface and the fourth conical surface form an angle θ2 with the central axis of the rotating part.

[0016] In some optional embodiments, the bending portion of the endoscope is cut integrally from a hollow tube.

[0017] The present application also provides an endoscope, comprising the bending portion as described above.

[0018] According to the bending portion of the endoscope in the above embodiment, it includes a plurality of snake bone units which are arranged in sequence end to end along its length direction, the snake bone unit includes a snake bone body, a male joint and a female joint, the male joint and the female joint are respectively arranged at the two ends of the snake bone body along the length direction, the male joint of one snake bone unit is rotatably connected to the female joint of another adjacent snake bone unit, the male joint is provided with a first conical surface, the female joint is provided with a second conical surface, the first conical surface and the second conical surface cooperate with each other, on a first section of the bending portion perpendicular to its length direction, the extension lines of the first conical surface and the second conical surface do not intersect with the center of the first section, so that the radial interference of the mating surfaces of the two conical surfaces is increased, which helps to improve the lateral bending strength of the bending portion, thereby avoiding the lateral dislocation of the bending portion in clinical application scenarios where instrument clamping is frequently used, and improving the service life of the bending portion. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 A schematic diagram of the structure of a bending portion at a certain angle in an embodiment;

[0020] Figure 2 is a bending schematic diagram of a bending portion in an embodiment;

[0021] Figure 3 is a schematic structural diagram of a bending portion at another angle in an embodiment;

[0022] FIG4 is a schematic diagram of the structure of a conventional bending portion. Figure 4a It is a schematic diagram of the structure of the bending portion in a direction parallel to the width; Figure 4b It is a schematic diagram of the structure of the bending part parallel to the height direction. Figure 4c for Figure 4a The cross-sectional structure diagram of A1-A1 in the figure. Figure 4d It is a schematic diagram of the bending portion when it is bent;

[0023] Figure 5 This is a schematic diagram of the structure of the bending portion in parallel to the height direction in an embodiment;

[0024] Figure 6 for Figure 5 Schematic diagram of the cross-sectional structure of AA;

[0025] Figure 7 for Figure 5 Schematic diagram of the cross-sectional structure of the middle BB;

[0026] Figure 8 It is a schematic diagram when the CC section is cut on the BB;

[0027] Fig. 9 It is a schematic diagram of the cross-sectional structure of CC;

[0028] Fig.10 is a schematic structural diagram of a bending portion in another embodiment;

[0029] Fig.11 FIG. 4 is a schematic diagram of the cross-sectional structure of the bending portion BB in another embodiment.

[0030] Among them: 1. snake bone unit; 11. snake bone body; 12. male joint; 121. first protrusion; 1211. first conical surface; 122. second concave portion; 1221. third conical surface; 13. female joint; 131. first concave portion; 1311. second conical surface; 132. second protrusion; 1321. fourth conical surface; 14. rotating portion; X, length direction; Y, width direction; Z, height direction; OO, central axis of the bending portion; E, central axis of the rotating portion. DETAILED DESCRIPTION

[0031] The present application is further described in detail below by specific embodiments in conjunction with the accompanying drawings. Wherein similar elements in different embodiments adopt associated similar element numbers. In the following embodiments, many detailed descriptions are intended to enable the present application to be better understood. However, those skilled in the art can easily recognize that some of the features can be omitted in different situations, or can be replaced by other elements, materials, and methods. In some cases, some operations related to the present application are not shown or described in the specification, in order to avoid the core part of the present application being overwhelmed by too much description, and for those skilled in the art, it is not necessary to describe these related operations in detail, and they can fully understand the related operations based on the description in the specification and the general technical knowledge in the art.

[0032] In addition, the features, operations or characteristics described in the specification can be combined in any appropriate manner to form various implementations, and the operation steps involved in each embodiment can also be replaced or adjusted in a sequence in a manner that is obvious to those skilled in the art. Therefore, the specification and drawings are only for the purpose of clearly describing a certain embodiment and do not mean that the composition and / or sequence are necessary.

[0033] The serial numbers of the components in this document, such as "first", "second", etc., are only used to distinguish the objects described and do not have any order or technical meaning. The "connection" and "coupling" mentioned in this application, unless otherwise specified, include direct and indirect connections (couplings).

[0034] It should be noted that when an element is referred to as being "fixed to" another element, it may be directly on the other element or there may be a central element. When an element is considered to be "connected to" another element, it may be directly connected to the other element or there may be a central element at the same time. The terms "vertical", "horizontal", "left", "right" and similar expressions used herein are for illustrative purposes only.

[0035] In the present application, the terms "upper", "lower", "left", "right", "front", "back", "top", "bottom", "inside", "outside", "middle", "vertical", "horizontal", "lateral", "longitudinal" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings. These terms are mainly intended to better describe the present application and its embodiments, and are not intended to limit the indicated devices, elements or components to have a specific orientation, or to be constructed and operated in a specific orientation. Moreover, in addition to being used to indicate orientation or positional relationships, some of the above terms may also be used to express other meanings. For example, the term "upper" may also be used to indicate a certain dependency or connection relationship in some cases. For those of ordinary skill in the art, the specific meanings of these terms in the present application can be understood according to the specific circumstances.

[0036] In addition, the terms "installed", "set", "provided with", "connected", and "connected" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral structure; it can be a mechanical connection, or an electrical connection; it can be a direct connection, or an indirect connection through an intermediate medium, or it can be an internal connection between two devices, elements, or components. For those of ordinary skill in the art, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0037] In order to more clearly describe the structure of the present application, "proximal" and "distal" are used as directional words. "Proximal" refers to the end of the structure close to the operator when in use, and "distal" refers to the end of the structure far away from the operator when in use, that is, the end close to the patient or extending into the patient's body.

[0038] The present application provides an endoscope, which can be a laparoscope, a pyeloscope, etc. The endoscope includes an operating handle (not shown in the figure), an insertion tube and a front end assembly (not shown in the figure) arranged in sequence from the proximal end to the distal end, the insertion tube is arranged at the proximal end of the front end assembly, the operating handle is arranged at the proximal end of the insertion tube, and at least part of the insertion tube is inserted and fixed in or on the operating handle, the insertion tube can be inserted into a target position (such as a lesion position), and the operating handle can control the insertion tube and the front end assembly to move and rotate to adjust its position. The front end assembly includes a camera module and a lighting module, and a clear image of the target position can be obtained through the cooperation of the camera module and the lighting module for intuitive viewing by the operator or the patient. The insertion tube includes a bending portion, which can be bent to different angles to adapt to different forms of cavities in the human body, so that the front end assembly can be smoothly driven to the target position to help complete the observation, detection or diagnosis work.

[0039] See also Figures 1 to 3 , Figures 5 to 11 The bending portion has a proximal end and a distal end, which are consistent with the proximal and distal directions of the endoscope, and has a length direction X extending from the proximal end to the distal end, and also has a width direction Y and a height direction Z, and the length direction X, the width direction Y and the height direction Z are perpendicular to each other. The bending portion includes a plurality of snake bone units 1 arranged end to end in sequence along its length direction X, and the snake bone unit 1 includes a snake bone body 11, a male joint 12 and a female joint 13, and the male joint 12 and the female joint 13 are respectively arranged at the two ends of the snake bone body 11 along the length direction X, that is, at the distal end and the proximal end of the snake bone body 11, and the male joint 12 of one snake bone unit 1 is rotatably connected to the female joint 13 of another adjacent snake bone unit 1, so that the bending portion can be bent to different angles. A first conical surface 1211 is provided on the male connector 12, and a second conical surface 1311 is provided on the female connector 13. The first conical surface 1211 and the second conical surface 1311 cooperate with each other, and the bending portion has a first section AA perpendicular to its length direction X. On the first section AA, the extension lines of the first conical surface 1211 and the second conical surface 1311 do not intersect with the center of the first section AA (the point where the central axis OO of the bending portion intersects with the section AA), and the male connector 12 and the female connector 13 cooperate with each other to form a rotating portion 14.

[0040] It can be understood that on the first section AA, there is a radial interference W between the mating surfaces of two adjacent snake bone units 1, and the lateral bending strength of the bent portion is related to the radial interference W. When the structure remains unchanged, the larger the radial interference W, the better the lateral bending strength of the bent portion.

[0041] See also Figures 4a to 4dIn a conventional bending portion, on a first section A1-A1 perpendicular to the length direction X of the bending portion, the extension lines L1 of the mating surfaces of two adjacent snake bone units 1 will pass through the center of the first section A1-A1, and the included angle with the center line of the section is α (e.g. Figure 4c As shown), the radial interference W1 is small and the bending strength of the bent portion is low.

[0042] In the bending part, the radial interference W is related to the diameter H of the rotating part 14, the outer diameter D of the serpentine unit 1 (which is a hollow tube), and the wall thickness T of the serpentine unit 1. The diameter H of the rotating part 14 is related to the outer diameter D of the serpentine unit 1. When the outer diameter D of the serpentine unit 1 is constant, if the diameter H of the rotating part 14 is too large, when the serpentine units 1 rotate relative to each other, the side of the serpentine unit 1 protrudes too much from the outer arc L of the serpentine (such as Figure 4d As shown in the figure, there is a risk of puncturing the polymer tube wrapped on the outer surface of the curved portion. The outer diameter D of the snake bone unit 1 is often limited by the outer diameter size of the endoscope insertion portion, and the wall thickness T of the snake bone unit 1 is limited by the contents of the endoscope insertion portion. Therefore, the radial interference W cannot be adjusted by adjusting the diameter H of the rotating portion 14, the outer diameter D of the snake bone unit 1, and the wall thickness T of the snake bone unit 1.

[0043] The present application creatively adjusts the mating surface to increase the radial interference W by adjusting the inclination angle of the mating surface, thereby solving the problem of anti-bending strength.

[0044] See also Figure 6 In this application, the extension lines of the first conical surface 1211 and the second conical surface 1311 are L2 and L3 respectively, the radial interference of the conical surface matching is W2, and the radial thickness is T2. The radial width of the traditional curved portion is T1, and there is an angle γ between the extension lines L1 of the two matching surfaces, which can be ignored because it is small (related to the slit width M, usually M≤0.03mm). Set the extension line L1 to form an angle β with the extension line L2 of the first conical surface 1211 of this application, then W1≈sinα*T1, W2≈sin(α+β)*T2, T2 is slightly larger than T1, for the convenience of analysis, T2=T1, the difference in radial interference between the two △W=W2-W1, where T1 is equal to the wall thickness T of the snake bone body 11. Take the snake bone cut with an outer diameter of Ф5mm and a wall thickness of 0.5mm as an example, according to actual experience, M≈0.025mm. Take the cross-section perpendicular to the length direction X of the bend for analysis, assuming that α is 22°, then W1≈sinα*T1≈sin(22°)*0.5≈0.187mm. If β is designed to be 5°, W2≈sin(α+β)*T2≈sin(α+β)*T1, so W2≈sin(27°)*0.5=0.227mm, △W / W1≈(0.227-0.187) / 0.187≈0.214.

[0045] It can be seen that, unlike the traditional bending part, the bending part of the present application is provided with a first conical surface 1211 on the male connector 12, and a second conical surface 1311 on the female connector 13. On the first section AA perpendicular to the length direction X of the bending part, the extension lines of the first conical surface 1211 and the second conical surface 1311 do not intersect with the center of the first section AA, which can increase the radial interference of the mating surface to W, and help to improve the lateral bending strength of the bending part, thereby avoiding the lateral dislocation of the bending part in clinical application scenarios where instrument clamping is frequently used, and improving the service life of the bending part.

[0046] Furthermore, the bent portion has a second cross section BB perpendicular to the width direction thereof and passing through the central axis E of the rotating portion 14 , and the bent portion has a third cross section CC perpendicular to the height direction thereof.

[0047] See also Figure 7 , on the above-mentioned second section BB, the extension lines of the first conical surface 1211 and the second conical surface 1311 form an angle θ1 with the central axis E of the rotating part 14, that is, the extension lines L2 and L3 of the first conical surface 1211 and the second conical surface 1311 are not parallel to the central axis E of the rotating part 14. Different from the traditional bending part in which the extension line L1 is parallel to the central axis E of the rotating part 14 and perpendicular to the central axis OO on the second section BB, the design of the present application makes the bending part on the second section BB also have a certain radial interference F, F = T * tan (θ1) - M, θ1 = β (θ1 = α + β, at this time α = 0°), F = 0.5 * tan (8°) - 0.025 ≈ 0.045mm. Obviously, when the wall thickness of the serpentine body 11 remains unchanged, the radial interference F of the conical surface fit between the serpentine units 1 can be increased by adjusting the β angle or the θ1 angle to further improve the lateral anti-bending strength of the bending part.

[0048] In some optional embodiments, θ1 is greater than 0°, and the value of θ1 is an acute angle greater than 0° and less than 90°. Exemplarily, θ1 can be 5°, 10°, 30°, 45° or other acute angle values.

[0049] In some optional embodiments, there is a gap between the first conical surface 1211 and the second conical surface 1311, which provides a margin of movement for the female connector 13 and the male connector 12 when they rotate, thereby helping the first conical surface 1211 and the second conical surface 1311 to rotate around the central axis E of the rotating portion 14, and also increasing the bending angle of the bending portion to accommodate a cavity with a larger degree of bending.

[0050] In some optional embodiments, the male connector 12 includes a first protruding portion 121 protruding relative to the snake bone body 11, and the female connector 13 includes a first recessed portion 131 recessed relative to the snake bone body 11; the first conical surface 1211 is formed on the outer peripheral wall of the first protruding portion 121, and the second conical surface 1311 is formed on the inner peripheral wall of the first recessed portion 131.

[0051] In some optional embodiments, the first conical surface 1211 includes a plurality of first conical portions that are arranged at intervals or continuously, and the plurality of first conical portions are arranged around the outer peripheral wall of the first protruding portion 121, that is, a conical surface can be partially arranged on the outer peripheral wall of the first protruding portion 121, and other areas can be traditional mating surface structures. Of course, the outer peripheral wall can also be entirely arranged as a conical surface. The second conical surface 1311 includes a plurality of second conical portions that are arranged at intervals or continuously, and the plurality of second conical portions are arranged around the inner peripheral wall of the first recessed portion 131. The second conical surface 1311 is arranged in the same manner as the first conical surface 1211, and a conical surface can be arranged entirely or partially. In this embodiment, the structures of the first conical surface 1211 and the second conical surface 1311 can be exactly the same or different, that is, one of them is partially provided with a conical surface, and the other is completely provided with a conical surface, as long as the first conical surface 1211 and the second conical surface 1311 can cooperate with each other, and from the overall view, on the first section AA perpendicular to the length direction X of the bending portion, the extension lines of the first conical surface 1211 and the second conical surface 1311 do not intersect with the center of the first section AA.

[0052] In some optional embodiments, the male connector 12 also includes a second recessed portion 122 arranged on both sides of the first protrusion 121, and the female connector 13 also includes a second protrusion 132 arranged on both sides of the first recessed portion 131, and the second protrusion 132 and the snake bone body 11 are combined to form the first recessed portion 131; a third conical surface 1221 is provided on the inner peripheral wall of the second recessed portion 122, and a fourth conical surface 1321 is provided on the outer peripheral wall of the second protrusion 132, and the third conical surface 1221 and the fourth conical surface 1321 cooperate with each other, thereby increasing the contact area between the male connector 12 and the female connector 13, so as to improve the connection stability of the bending portion.

[0053] In some optional embodiments, on the first section AA perpendicular to the length direction X of the bending portion, the extension lines of the third conical surface 1221 and the fourth conical surface 1321 do not intersect with the center of the first section AA (the point where the central axis OO of the bending portion intersects with the section AA), and there is a gap between the third conical surface 1221 and the fourth conical surface 1321 so that the third conical surface 1221 and the fourth conical surface 1321 can rotate around the central axis E of the rotating portion 14.

[0054] Please continue reading Figure 3In some embodiments, the first protrusion 121 is protruded relative to the snake bone body 11 along the length direction X, and the second recessed portion 122 is also recessed relative to the snake bone body 11 along the length direction X. The first recessed portion 131 is recessed relative to the snake bone body 11 along the length direction X, and the second protrusion 132 is also protruded relative to the snake bone body 11 along the length direction X, that is, the docking direction of the male connector 12 and the female connector 13 is consistent with the length direction X of the bending portion.

[0055] Of course, see Fig.10 In other embodiments, the protruding directions of the first protrusion 121 and the second protrusion 132 relative to the serpentine body 11, and the recessed directions of the first recessed portion 131 and the second recessed portion 122 relative to the serpentine body 11 both form an angle σ greater than 0° with the central axis of the serpentine unit 11 (parallel to the central axis OO of the bending portion when not bent). For example, the protruding directions of the first protrusion 121 and the second protrusion 132 relative to the serpentine body 11, and the recessed directions of the first recessed portion 131 and the second recessed portion 122 relative to the serpentine body 11 can be parallel to the width direction Y or the height direction Z, that is, they form a 90° angle with the central axis of the serpentine unit 11. In this embodiment, please refer to Fig.11 On the second section BB, the extension lines L4 and L5 of the third conical surface 1221 and the fourth conical surface 1321 form an angle θ2 with the central axis E of the rotating portion 14; through the matching design of the third conical surface 1221 and the fourth conical surface 1321, the principle is the same as that of the first conical surface 1211 and the second conical surface 1311, and the non-intersecting design and the design of the angle θ2 can also help to increase the radial interference, thereby improving the lateral bending strength of the bending portion.

[0056] In some optional embodiments, the curved portion of the endoscope is cut from a hollow tube in one piece. When cutting, the cutting device is made to form a certain angle with the radial direction and the axial direction of the hollow tube, which helps to quickly form the first tapered surface 1211, the second tapered surface 1311, the third tapered surface 1221 and the fourth tapered surface 1321, thereby improving the integrity and consistency of the curved portion, and also helps in mass production, improving the production efficiency and yield rate of the curved portion.

[0057] The second embodiment of the present application provides the bending portion mentioned above, and its structure has been described in detail above, so it will not be elaborated here.

[0058] The above specific examples are used to illustrate the present application, which is only used to help understand the present application and is not intended to limit the present application. For technicians in the technical field to which the present application belongs, they can also make some simple deductions, deformations or substitutions based on the ideas of the present application.

Claims

1. An endoscope bending portion, characterized in that: It comprises a plurality of snake bone units which are arranged end to end in sequence along the length direction thereof; The snake bone unit comprises a snake bone body, a male joint and a female joint, wherein the male joint and the female joint are respectively arranged at two ends of the snake bone body along the length direction; The male joint of one of the snake-bone units is rotatably connected to the female joint of another adjacent snake-bone unit; the male joint is provided with a first conical surface, the female joint is provided with a second conical surface, and the first conical surface and the second conical surface cooperate with each other; The bent portion has a first cross section in a direction perpendicular to the length thereof, and in the first cross section, an extension line of the first tapered surface and the second tapered surface does not intersect with a center of the first cross section.

2. The endoscope bending portion according to claim 1, characterized in that: The male connector and the female connector cooperate with each other to form a rotating part, and the curved part has a second cross-section perpendicular to its width direction and passing through the central axis of the rotating part. On the second cross-section, the extension lines of the first conical surface and the second conical surface form an angle θ1 with the central axis of the rotating part.

3. The endoscope bending portion according to claim 2, characterized in that: The angle θ1 is greater than 0°.

4. The endoscope bending portion according to claim 2, characterized in that: A gap is provided between the first tapered surface and the second tapered surface so that the first tapered surface and the second tapered surface can rotate around the central axis of the rotating portion.

5. The endoscope bending portion according to claim 2, characterized in that: The male connector includes a first protrusion protruding from the serpentine body, and the female connector includes a first recessed portion recessed from the serpentine body; the first conical surface is formed on the outer peripheral wall of the first protrusion, and the second conical surface is formed on the inner peripheral wall of the first recessed portion.

6. The endoscope bending portion according to claim 5, characterized in that: The first conical surface includes a plurality of first conical portions which are arranged at intervals or continuously, and the plurality of first conical portions are arranged around the outer peripheral wall of the first protruding portion; the second conical surface includes a plurality of second conical portions which are arranged at intervals or continuously, and the plurality of second conical portions are arranged around the inner peripheral wall of the first recessed portion.

7. The endoscope bending portion according to claim 5, characterized in that: The male connector also includes a second recessed portion arranged on both sides of the first protrusion, and the female connector also includes a second protrusion arranged on both sides of the first recessed portion, and the second protrusion and the snake bone body are combined to form the first recessed portion; a third conical surface is provided on the inner circumferential wall of the second recessed portion, and a fourth conical surface is provided on the outer circumferential wall of the second protrusion, and the third conical surface and the fourth conical surface are matched; on the first section, the extension lines of the third conical surface and the fourth conical surface do not intersect with the center of the first section; there is a gap between the third conical surface and the fourth conical surface, so that the third conical surface and the fourth conical surface can rotate around the central axis of the rotating part.

8. The endoscope bending portion according to claim 7, characterized in that: The protruding directions of the first protrusion and the second protrusion relative to the serpentine body and the recessed directions of the first recessed portion and the second recessed portion relative to the serpentine body both form an angle greater than 0° with the central axis of the serpentine unit. On the second section, the extension lines of the third conical surface and the fourth conical surface form an angle θ2 with the central axis of the rotating part.

9. The endoscope bending portion according to claim 1, characterized in that: The endoscope bending portion is formed by cutting a hollow tube in one piece.

10. An endoscope, characterized in that: Comprising the endoscope bending portion as described in any one of claims 1-9.

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