Active bending section and endoscope

Abstract

The invention discloses an active bending section and an endoscope, and relates to the technical field related to endoscopes, the active bending section comprises a snake bone head section and a plurality of snake bone joints which are sequentially connected end to end, the snake bone head section is rotatably connected with the adjacent snake bone joints, one end of each snake bone joint is fixedly provided with a protruding ball head, and the other end of each snake bone joint is fixedly provided with a ball. One end of each snake-shaped joint is fixedly provided with a ball head, the other end of each snake-shaped joint is fixedly provided with a ball socket matched with the ball head for use, every two adjacent snake-shaped joints are rotationally connected through the ball heads and the ball sockets, each ball socket is internally provided with a self-lubricating unit used for lubricating the corresponding ball head and the corresponding ball socket, and each snake-shaped joint is fixedly provided with a fixing lug and is provided with a traction steel wire through the fixing lug; according to the self-lubricating ball head, self-lubricating operation between the ball head and the ball socket can be achieved when the ball head rotates, the rotating friction resistance between the ball head and the ball socket can be reduced, relative movement is smoother during bending, the abrasion degree can be reduced, chippings generated due to abrasion are reduced, and potential damage to human tissue is avoided.

Description

Technical Field

[0001] The present invention relates to the technical field of endoscopes, and particularly to an active bending section and an endoscope. Background Art

[0002] As a medical diagnostic instrument, an endoscope can enter the body and take images of the lesion site through a camera encapsulated at its distal end, providing sufficient diagnostic information for doctors to treat diseases. The endoscope includes an insertion section, which can enter the human body through a body cavity or a surgical incision.

[0003] Most of the existing active bending sections of endoscopes are formed by riveting multiple pivot units, or are integrally cut from a tubular member. For the rotational bending section formed by riveting multiple pivot units, when two adjacent snake bone joints rotate relative to each other, the frictional force between the contact surfaces is large. When the bending angle changes, a large static frictional force needs to be overcome between the planes to generate relative displacement, which increases the driving force required for bending operation. Moreover, the large frictional resistance easily causes wear at the connection of the snake bone joints, shortening the service life of the snake bone pieces. Although the active bending section integrally cut from a tubular member has lower requirements for manufacturing and tooling, when the force between two adjacent pivot units is large, there is an easy situation of detachment, that is, the stability of the active bending section is poor. In addition, most of the existing traction wires of endoscopes are fixed to the first snake bone section simply by clamping, riveting or welding. The fixing method is relatively single and the stability is poor. After multiple pulls of the traction wire, the fixing point of the traction wire and the first snake bone section is prone to fatigue damage, resulting in loosening of the connection between the traction wire and the first snake bone section, affecting the control effect of the traction wire on the active bending section. Summary of the Invention

[0004] To solve the defects existing in the prior art, the present invention provides an active bending section and an endoscope.

[0005] To solve the above technical problems, the present invention provides the following technical solutions:

[0006] An active bending section of the present invention includes a first snake bone section and a plurality of snake bone joints connected end to end in sequence. The first snake bone section is rotatably connected to the adjacent snake bone joint. A protruding ball head is fixedly installed at one end of the snake bone joint, and a ball socket cooperating with the ball head is fixedly installed at the other end. Two adjacent snake bone joints are rotatably connected through the ball head and the ball socket. A self-lubricating unit for lubricating the ball head and the ball socket is provided in each ball socket. A fixing ear is fixedly installed on the snake bone joint and a traction wire is arranged through the fixing ear. A wire threading tube for threading the traction wire is fixedly installed on each snake bone joint. A fixing component for fixing the traction wire is provided on the first snake bone section. A gap is left between two adjacent snake bone joints.

[0007] As a preferred technical solution of the present invention, the self-lubricating unit includes an anti-slip ring fixedly installed at the opening of the ball socket, an annular oil storage cavity is fixedly installed on the inner wall of the anti-slip ring and grease is stored in the annular oil storage cavity, a plurality of balls are rotatably installed in the annular oil storage cavity, the plurality of balls are all fitted with adjacent ball heads on the same side, and each of the balls is provided with an oil leakage groove along its circumferential direction.

[0008] As a preferred technical solution of the present invention, a damping washer is fixedly installed on the inner wall of the anti-dropping clamp ring above the annular oil storage cavity, and the damping washer fits with the adjacent ball head on the same side.

[0009] As a preferred technical solution of the present invention, the fixing assembly includes an anchor fixedly installed at the distal end of the traction wire, the anchor is in the shape of a barb, the anchor has a clamping portion for clamping with the fixing ear on the same side, and the fixing ear and the anchor are rigidly connected with the fixing ear by laser welding, the traction wire is sleeved with an elastic bushing, and the elastic bushing and the inner wall of the fixing ear are provided with spiral anti-slip patterns for engaging with the knurling on the surface of the traction wire, so as to prevent the traction wire from axially moving.

[0010] As a preferred technical solution of the present invention, an anti-slip pressure plate is fixedly installed on the first section of the snake bone, and the anti-slip pressure plate is arranged on the outer surface of the elastic bushing. The anti-slip pressure plate is made of shape memory alloy material, maintains an expanded state at room temperature, and shrinks and locks after heating.

[0011] As a preferred technical solution of the present invention, a plurality of limiting grooves are fixedly mounted on the outer surface of the elastic bushing, and a plurality of limiting protrusions used in conjunction with the limiting grooves are arranged on the anti-slip pressure sheet.

[0012] As a preferred technical solution of the present invention, the plurality of snake bone segments are distributed axially along the first segment of the snake bone, and avoidance grooves are symmetrically provided on the upper and lower sides of the snake bone segments.

[0013] As a preferred technical solution of the present invention, the side where the ball head is located is the rotating side of the serpentine joint, the threading tube is arranged on the bending side of the serpentine joint and offset to the rotating side of the serpentine joint, an elastic air bag is arranged in the threading tube near the rotating side of the serpentine joint, and the elastic air bag is arranged between the threading tube and the traction wire.

[0014] As a preferred technical solution of the present invention, a guide piece is fixedly mounted on one end of the snake bone segment, and a guide groove used in conjunction with the guide piece is provided on the other end.

[0015] An endoscope comprises the active bending section described in any one of the above technical solutions.

[0016] The beneficial effects of the present invention are as follows:

[0017] 1. For this kind of active bending section and endoscope, by setting the ball head, ball socket and self-lubricating unit, when the traction wire is pulled, the ball head between adjacent snake bone joints rotates relatively in the ball socket, thereby causing multiple snake bone joints to bend. Through the combined use of the ball head and ball socket, the stress distribution at the ball head and ball socket is more uniform, reducing the problem of local stress concentration, reducing the risk of damage to the rotation structure between adjacent snake bone joints caused by stress concentration, and extending the service life of the endoscope snake bone joints.

[0018] 2. For this kind of active bending section and endoscope, by setting the ball head, ball socket and self-lubricating unit, when the snake bone joint bends, relative rotation occurs between the ball head and the ball socket. The rotation of the ball head drives multiple ball bearings to rotate. The shear force generated during the rotation of the ball bearings will reduce the viscosity of the grease in the annular oil storage cavity, causing the grease to turn into a liquid and leak out through the oil leakage groove, and coating the grease on the ball head during the process of contacting and rotating with the ball head. At the same time, due to the frictional rotation between the ball bearings and the ball head, when the ball head rotates, the frictional heat reduces the viscosity of the lubricant, and continuously seeps out to the contact surface through the oil leakage groove, forming a lubricating film on one side between the ball head and the ball socket. Therefore, self-lubrication operation between the ball head and the ball socket can be achieved when the ball head rotates, which can reduce the frictional resistance of the rotation between the ball head and the ball socket, make the relative movement smoother during bending, and can reduce the wear degree, reduce the debris generated by wear, and avoid potential harm to human tissues.

[0019] 3. For this kind of active bending section and endoscope, by setting the fixing component, a rigid connection is formed by welding between the anchor and the fixing ear, which can ensure the stability of the connection between the traction wire and the first snake bone section. At the same time, through the mechanical bite formed between the elastic bushing and the spiral anti-slip pattern on the inner wall of the fixing ear and the traction wire, the stability of the connection between the traction wire and the first snake bone section can be further ensured, avoiding loosening and fatigue fracture between the traction wire and the first snake bone section. The anti-disconnection pressing piece shrinks when heated to fix the elastic bushing and ensure the stability of the elastic bushing. When the endoscope is in use, the stability of the traction wire can be further improved by locking the elastic bushing. Therefore, the traction wire is fixed at multiple levels by the anchor, elastic bushing, spiral anti-slip pattern and anti-disconnection pressing piece, which can effectively ensure the stability of the installation of the traction wire, avoid loosening of the traction wire during use, and ensure the precise control of the active bending section by the traction wire.

[0020] 4. For this kind of active bending section and endoscope, by providing an elastic airbag, when the active bending end of the endoscope is inserted into the human body, the gas in the elastic airbag expands when heated. Since the elastic airbag is arranged inside the wire threading tube near the rotating side of the snake bone joint and is located between the wire threading tube and the traction wire, the expansion of the elastic airbag will push the traction wire to deviate towards the side away from the rotating side under the limitation of the wire threading tube, preventing the traction wire from moving towards the rotating side of the snake bone joint when being pulled, and ensuring the control accuracy of the active bending section. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] The drawings are used to provide a further understanding of the present invention, and constitute a part of the specification. Together with the embodiments of the present invention, they are used to explain the present invention, but do not constitute a limitation to the present invention.

[0022] In the drawings:

[0023] Figure 1 is the overall structural schematic diagram of an active bending section and an endoscope of the present invention;

[0024] Figure 2 is the structural schematic diagram of the wire threading tube of an active bending section and an endoscope of the present invention;

[0025] Figure 3 is the structural schematic diagram of the snake bone joint of an active bending section and an endoscope of the present invention;

[0026] Figure 4 is the structural schematic diagram of the self-lubricating unit of an active bending section and an endoscope of the present invention;

[0027] Figure 5 is the present invention Figure 4 the enlarged schematic diagram of the structure at A in;

[0028] Figure 6 is the sectional structural schematic diagram of the ball socket of an active bending section and an endoscope of the present invention;

[0029] Figure 7 is the structural schematic diagram of the fixing component of an active bending section and an endoscope of the present invention;

[0030] Figure 8 is the structural schematic diagram of the anti-disengagement pressing piece of an active bending section and an endoscope of the present invention;

[0031] Figure 9 is the structural schematic diagram of the elastic bushing of an active bending section and an endoscope of the present invention;

[0032] Figure 10 is the structural schematic diagram of the elastic airbag of an active bending section and an endoscope of the present invention.

[0033] In the figure: 1. First snake bone section; 2. Ball head; 3. Ball socket; 4. Self-lubricating unit; 41. Anti-disengagement snap ring; 42. Annular oil storage cavity; 43. Ball; 44. Oil leakage groove; 45. Damping washer; 5. Fixed ear; 6. Traction wire; 7. Wire conduit; 8. Fixing assembly; 81. Anchor; 82. Clamping part; 83. Elastic bushing; 84. Spiral anti-slip pattern; 85. Limiting groove; 86. Limiting protrusion; 87. Elastic airbag; 88. Anti-disengagement pressing piece; 9. Avoidance groove; 10. Guide piece; 11. Guide groove; 12. Gap; 13. Snake bone section. Detailed implementation mode

[0034] The following is a description of the preferred embodiments of the present invention in conjunction with the accompanying drawings. It should be understood that the preferred embodiments described herein are only used to illustrate and explain the present invention, and are not used to limit the present invention.

[0035] Embodiment: As Figures 1 to 10 shown, an active bending section of the present invention includes a first snake bone section 1 and a plurality of snake bone sections 13 connected end to end in sequence. The first snake bone section 1 is rotatably connected to the adjacent snake bone section 13. A protruding ball head 2 is fixedly installed at one end of the snake bone section 1, and a ball socket 3 cooperating with the ball head 2 is fixedly installed at the other end. The adjacent two snake bone sections 13 are rotatably connected through the ball head 2 and the ball socket 3. A self-lubricating unit 4 for lubricating the ball head 2 and the ball socket 3 is arranged in each ball socket 3. A fixed ear 5 is fixedly installed on the snake bone section 1 and a traction wire 6 is arranged through the fixed ear 5. A wire conduit 7 for passing the traction wire 6 is fixedly installed on each snake bone section 1. A fixing assembly 8 for fixing the traction wire 6 is arranged on the first snake bone section 1. A gap 12 is left between the adjacent two snake bone sections 13. When it is necessary to bend the snake bone section 13, the traction wire 6 is pulled, so that the ball head 2 between the adjacent snake bone sections 13 rotates relative to each other in the ball socket 3, and then the plurality of snake bone sections 13 are bent. Compared with the traditional connection method between the snake bone sections 13, through the cooperation of the ball head 2 and the ball socket 3, the stress distribution at the ball head 2 and the ball socket 3 is more uniform, reducing the problem of local stress concentration, and reducing the risk of damage to the rotation structure between the adjacent snake bone sections 13 caused by stress concentration, and prolonging the service life of the snake bone section 13 of the endoscope.

[0036] Among them, as Figure 3 、 Figure 4 、 Figure 5 and Figure 6As shown, the self-lubricating unit 4 includes an anti-drop snap ring 41 fixedly installed at the opening of the ball socket 3. An annular oil storage cavity 42 is fixedly installed on the inner wall of the anti-drop snap ring 41, and grease is stored in the annular oil storage cavity 42. A plurality of balls 43 are rotatably installed in the annular oil storage cavity 42. The plurality of balls 43 are all in contact with the adjacent ball head 2 on the same side. An oil leakage groove 44 is provided on each ball 43 along its circumferential direction. When the snake bone joint 13 bends, relative rotation occurs between the ball head 2 and the ball socket 3. The rotation of the ball head 2 drives the plurality of balls 43 to rotate. The shear force generated during the rotation of the balls 43 will reduce the viscosity of the grease in the annular oil storage cavity 42, causing the grease to transform into a liquid state and leak out through the oil leakage groove 44. During the rotation in contact with the ball head 2, the grease is coated on the ball head 2. At the same time, due to the frictional rotation between the balls 43 and the ball head 2, when the ball head 2 rotates, the frictional heat reduces the viscosity of the lubricant, and it continuously seeps out through the oil leakage groove 44 to the contact surface, forming a lubricating film on one side between the ball head 2 and the ball socket 3. Thus, self-lubrication between the ball head 2 and the ball socket 3 can be achieved when the ball head 2 rotates, the frictional resistance during the rotation of the ball head 2 and the ball socket 3 can be reduced, the relative movement during bending is smoother, and the wear degree can be reduced, reducing debris generated by wear and avoiding potential harm to human tissues.

[0037] Among them, as Figure 4 and Figure 6 shown, a damping washer 45 is fixedly installed on the inner wall of the anti-drop snap ring 41 above the annular oil storage cavity 42. The damping washer 45 is in contact with the adjacent ball head 2 on the same side. By setting the damping washer 45, it can not only ensure the flexibility of the relative rotation between the snake bone joints 13, but also provide a certain amount of damping to prevent the snake bone joints 13 from shaking during the bending process and enhance the stability of the active bending section.

[0038] Among them, as Figure 2 、 Figure 7 、 Figure 8 、 Figure 9 and Figure 10As shown, the fixing component 8 includes an anchor 81 fixedly installed at the distal end of the traction wire 6. The anchor 81 is in the shape of a barbed hook, and the anchor 81 has a clamping portion 82 for clamping with the fixing ear 5 on the same side. The fixing ear 5 and the anchor 81 are rigidly connected by laser welding to the fixing ear 5. An elastic bushing 83 is sleeved on the traction wire 6, and spiral anti-slip threads 84 for engaging with the knurling on the surface of the traction wire 6 are provided on both the inner wall of the elastic bushing 83 and the fixing ear 5 to prevent the axial movement of the traction wire 6. A rigid connection is formed by welding between the anchor 81 and the fixing ear 5. The clamping portion 82 can increase the contact area between the anchor 81 and the fixing ear 5, ensuring the stability of the connection between the traction wire 6 and the first snake bone segment 1. At the same time, mechanical engagement is formed between the spiral anti-slip threads 84 on the inner wall of the elastic bushing 83 and the fixing ear 5 and the traction wire 6, which can further ensure the stability of the connection between the traction wire 6 and the first snake bone segment 1, guarantee the connection strength between the traction wire 6 and the first snake bone segment 1, and avoid loosening and fatigue fracture between the traction wire 6 and the first snake bone segment 1.

[0039] Among them, as Figure 7 , Figure 8 and Figure 9 shown, an anti-disengagement pressing piece 88 is fixedly installed on the first snake bone segment 1, and the anti-disengagement pressing piece 88 is arranged on the outer surface of the elastic bushing 83. The anti-disengagement pressing piece 88 is made of a shape memory alloy material, which remains in an expanded state at room temperature and shrinks and locks when heated. Before the endoscope is used, there is a gap 12 between the anti-disengagement pressing piece 88, the elastic bushing 83 and the traction wire 6, facilitating the insertion of the traction wire 6 and the elastic bushing 83. When the endoscope is in use, since the temperature of the human body environment is higher than the external operating environment temperature (the temperature in the operating room generally remains between 18 and 24 degrees Celsius), when the active bending end of the endoscope is inserted into the human body, the anti-disengagement pressing piece 88 made of memory alloy shrinks when heated and fixes the elastic bushing 83, ensuring the stability of the elastic bushing 83. The stability of the fixation of the traction wire 6 can be further improved by locking the elastic bushing 83 when the endoscope is in use. Thus, the traction wire 6 is fixed at multiple levels by the anchor 81, the elastic bushing 83, the spiral anti-slip threads 84 and the anti-disengagement pressing piece 88, effectively ensuring the stability of the installation of the traction wire 6, avoiding loosening of the traction wire 6 during use, and ensuring the precise control of the traction wire 6 over the active bending section.

[0040] Among them, as Figure 9 shown, a plurality of limiting grooves 85 are fixedly installed on the outer surface of the elastic bushing 83, and a plurality of limiting protrusions 86 cooperating with the limiting grooves 85 are provided on the anti-disengagement pressing piece 88. By the cooperation of the limiting grooves 85 and the limiting protrusions 86, the contact area between the elastic snap ring and the elastic bushing 83 can be increased, the locking and fixing effect of the elastic snap ring on the elastic bushing 83 can be improved, and the stability of the fixation and locking of the traction wire 6 can be further improved.

[0041] Among them, Figure 1 , Figure 2 and Figure 3 As shown, multiple snake bone joints 13 are distributed axially along the snake bone first joint 1, and avoidance grooves 9 are symmetrically opened on the upper and lower sides of the snake bone joints 13 to avoid interference between two adjacent snake bone joints 13 when bending and rotating, ensuring the smooth rotation of two adjacent snake bone joints 13.

[0042] Among them, Figure 1 , Figure 2 and Figure 10 As shown, the side where the ball head 2 is located is the rotating side of the serpentine joint 13, the threading tube 7 is arranged on the bending side of the serpentine joint 13 and is offset to the rotating side of the serpentine joint 13, an elastic air bag 87 is arranged in the threading tube 7 near the rotating side of the serpentine joint 13, the elastic air bag 87 is arranged between the threading tube 7 and the traction wire 6, the threading tube 7 is arranged on the bending side of the serpentine joint 13 and is offset to the rotating side of the serpentine joint 13, when the endoscope is in use, the bending of the serpentine joint 13 and the bending of the traction wire 6 are prevented from interfering with each other, and at the same time, the pulling force of the traction wire 6 can effectively form a bending moment to ensure that the serpentine joint 13 rotates, by setting the elastic air bag 87 and utilizing the characteristic of the gas in the elastic air bag 87 expanding due to heat, before the endoscope is used, the elastic air bag 87 is arranged on the serpentine joint 13 and is offset to the rotating side of the serpentine joint 13. The airbag 87 is in a contracted state, which is convenient for the traction wire 6 to be inserted into the threading tube 7 and is easy to install. When the endoscope is in use, due to the high internal temperature of the human body and the external ambient temperature (the temperature of the operating room is generally maintained between 18 and 24 degrees Celsius), when the active bending end of the endoscope is inserted into the human body, the gas in the elastic airbag 87 expands due to the heat. Since the elastic airbag 87 is arranged in the threading tube 7 close to the rotating side of the serpentine joint 13 and is located between the threading tube 7 and the traction wire 6, the expansion of the elastic airbag 87 will push the traction wire 6 to deviate to the side away from the rotating side under the limit of the threading tube 7, and prevent the traction wire 6 from moving toward the rotating side of the serpentine joint 13 when being pulled, thereby ensuring the control accuracy of the active bending section.

[0043] Among them, Figure 1 , Figure 2 and Figure 3 As shown, a guide piece 10 is fixedly installed at one end of the serpentine joint 13, and a guide groove 11 used in conjunction with the guide piece 10 is opened at the other end. Through the coordinated use of the guide groove 11 and the guide piece 10, the bending direction of the serpentine joint 13 can be guided and limited, thereby ensuring the stability and controllability of the serpentine joint 13 when bending, and facilitating the user to accurately control the bending of the serpentine joint 13 when using it.

[0044] An endoscope comprises the active bending section in the above technical solution.

[0045] During operation, the traction wire 6 is successively passed through the fixing ear 5, the elastic bushing 83 and the wire conduit 7, and then welded to the fixing ear 5 through the anchor 81 on the traction wire 6 to complete the installation of the traction wire 6. This can ensure the stability of the connection between the traction wire 6 and the first snake bone section 1. At the same time, a mechanical bite is formed between the elastic bushing 83 and the spiral anti-slip pattern 84 on the inner wall of the fixing ear 5 and the traction wire 6, which can further ensure the stability of the connection between the traction wire 6 and the first snake bone section 1;

[0046] When the endoscope is in use, since the temperature of the human body environment is higher than the external use environment temperature (the temperature in the operating room generally remains between 18 and 24 degrees Celsius), when the active bending end of the endoscope is inserted into the human body, the anti-detachment pressing piece 88 made of shape memory alloy shrinks when heated to fix the elastic bushing 83, ensuring the stability of the elastic bushing 83. The stability of the fixation of the traction wire 6 can be further improved by locking the elastic bushing 83 during the use of the endoscope. At the same time, the gas in the elastic airbag 87 expands when heated. Since the elastic airbag 87 is arranged inside the wire conduit 7 near the rotating side of the snake bone section 13 and is located between the wire conduit 7 and the traction wire 6, the expansion of the elastic airbag 87 will push the traction wire 6 to shift away from the rotating side under the limit of the wire conduit 7, preventing the traction wire 6 from moving towards the rotating side of the snake bone section 13 when being pulled, and ensuring the control accuracy of the active bending section;

[0047] When the snake bone section 13 needs to be bent, the traction wire 6 is pulled, so that the ball head 2 between adjacent snake bone sections 13 rotates relatively in the ball socket 3, and then multiple snake bone sections 13 are bent. By using the cooperation of the ball head 2 and the ball socket 3, the stress distribution at the ball head 2 and the ball socket 3 is more uniform, reducing the problem of local stress concentration, reducing the risk of damage to the rotating structure between adjacent snake bone sections 13 caused by stress concentration, and extending the service life of the endoscope snake bone section 13. When the snake bone section 13 is bent, the ball head 2 and the ball socket 3 rotate relatively, and the rotation of the ball head 2 drives multiple ball bearings 43 to rotate. The shear force generated during the rotation of the ball bearings 43 will reduce the viscosity of the grease in the annular grease storage cavity 42, making the grease turn into a liquid state and leak out through the oil leakage groove 44, and coating the grease on the ball head 2 during the process of contacting and rotating with the ball head 2. At the same time, due to the frictional rotation between the ball bearings 43 and the ball head 2, when the ball head 2 rotates, the frictional heat reduces the viscosity of the lubricant, and continuously seeps out to the contact surface through the oil leakage groove 44 to form a lubricating film on one side between the ball head 2 and the ball socket 3. Thus, self-lubrication operation between the ball head 2 and the ball socket 3 can be realized when the ball head 2 rotates, which can reduce the frictional resistance of the rotation between the ball head 2 and the ball socket 3, make the relative movement smoother during bending, and can reduce the wear degree, reduce the debris generated by wear, and avoid potential harm to human tissues.

[0048] Finally, it should be noted that the above are only preferred embodiments of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or perform equivalent replacements for some of the technical features. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. An active bending section, comprising a first snake bone section (1) and a plurality of snake bone sections (13) connected end to end in sequence, characterized in that, The first snake bone segment (1) is rotatably connected to the adjacent snake bone segment (13). A protruding ball head (2) is fixedly installed at one end of the snake bone segment (13), and a ball socket (3) used in cooperation with the ball head (2) is fixedly installed at the other end. The adjacent two snake bone segments (13) are rotatably connected through the ball head (2) and the ball socket (3). A self-lubricating unit (4) for lubricating the ball head (2) and the ball socket (3) is arranged in each ball socket (3). A fixing ear (5) is fixedly installed on the snake bone segment (13), and a traction wire (6) is arranged through the fixing ear (5). A wire threading tube (7) for threading the traction wire (6) is fixedly installed on each snake bone segment (13). A fixing component (8) for fixing the traction wire (6) is arranged on the first snake bone segment (1). A gap (12) is left between the adjacent two snake bone segments (13).

2. The active bending section according to claim 1, characterized in that, The self-lubricating unit (4) includes an anti-drop snap ring (41) fixedly installed at the opening of the ball socket (3). An annular oil storage cavity (42) is fixedly installed on the inner wall of the anti-drop snap ring (41), and lubricating grease is stored in the annular oil storage cavity (42). A plurality of balls (43) are rotatably installed in the annular oil storage cavity (42). The plurality of balls (43) are all in contact with the adjacent ball head (2) on the same side. An oil leakage groove (44) is formed in each ball (43) along its circumferential direction.

3. An active bending section according to claim 2, characterized in that, A damping washer (45) is fixedly installed on the inner wall of the anti-drop snap ring (41) above the annular oil storage cavity (42). The damping washer (45) is in contact with the adjacent ball head (2) on the same side.

4. An active bending section according to claim 1, characterized in that, The fixing component (8) includes an anchor (81) fixedly installed at the distal end of the traction wire (6). The shape of the anchor (81) is a barbed shape. The anchor (81) has a clamping portion (82) for clamping with the fixing ear (5) on the same side. The fixing ear (5) and the anchor (81) are rigidly connected by laser welding with the fixing ear (5). An elastic bushing (83) is sleeved on the traction wire (6). Spiral anti-slip threads (84) for engaging with the knurling on the surface of the traction wire (6) are formed on the inner walls of the elastic bushing (83) and the fixing ear (5) to prevent the axial movement of the traction wire (6).

5. An active bending section according to claim 4, characterized in that, An anti-drop pressing piece (88) is fixedly installed on the first snake bone segment (1), and the anti-drop pressing piece (88) is arranged on the outer surface of the elastic bushing (83). The anti-drop pressing piece (88) is made of a shape memory alloy material and remains in an expanded state at normal temperature and shrinks and locks when heated.

6. The active bending section according to claim 5, wherein A plurality of limiting grooves (85) are fixedly installed on the outer surface of the elastic bushing (83). A plurality of limiting protrusions (86) used in cooperation with the limiting grooves (85) are arranged on the anti-drop pressing piece (88).

7. An active bending section according to claim 1, characterized in that, The plurality of snake bone segments (13) are all axially distributed along the first snake bone segment (1). Avoidance grooves (9) are symmetrically formed on both the upper and lower sides of the snake bone segment (13).

8. An active bending section according to claim 1, wherein, The side where the ball head (2) is located is the rotation side of the snake bone joint (13), the wire threading tube (7) is arranged on the bending side of the snake bone joint (13) and is offset towards the rotation side of the snake bone joint (13), an elastic airbag (87) is arranged inside the wire threading tube (7) close to the rotation side of the snake bone joint (13), and the elastic airbag (87) is arranged between the wire threading tube (7) and the traction steel wire (6).

9. The active bending section according to claim 8, wherein, One end of the snake bone joint (13) is fixedly installed with a guide piece (10), and the other end is provided with a guide groove (11) for cooperating with the guide piece (10).

10. An endoscope, characterized in that, It includes the active bending section according to any one of claims 1-9.

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