CN220069662U - Snake bone structure, flexible insertion structure, flexible detector and flexible mechanical arm - Google Patents

Abstract

The utility model provides a snake bone structure, which comprises a bendable main body formed by sequentially connecting a head end bone joint, a plurality of snake bone joints and a tail end bone joint which can rotate relatively, wherein spring sleeves are uniformly distributed on the side wall of the bendable main body along the circumferential direction; the head end and the tail end of the spring sleeve are respectively connected with the head end condyle and the tail end condyle; a pull rope is arranged in the spring sleeve in a penetrating way; the head end of the pull rope is connected with the head end condyle; the snake bone structure does not generate axial relaxation elastic force in any state. According to the snake bone structure, the flexible inserting structure, the flexible detector and the flexible mechanical arm, the snake bone structure has a good axial limiting effect through the cooperation of the limiting structure and the clamping structure, and the fine control precision of the snake bone is effectively improved through cooperation of the spring sleeve in a stretching state all the time, so that accurate control can be realized especially in a complex environment scene.

Description

Snake bone structure, flexible insertion structure, flexible detector and flexible mechanical arm

Technical Field

The utility model relates to the technical field of snake bone connecting structures, in particular to a snake bone structure, a flexible inserting structure, a flexible detector and a flexible mechanical arm.

Background

Surgical instruments such as endoscopes and flexible robots have taken an important place in minimally invasive surgery in the fields of abdominal cavity, digestion and the like due to the characteristics of small wounds, quick postoperative recovery and the like. The snake bones are an indispensable important component of the endoscope and the flexible robot mechanical arm due to the characteristics of simple control and hardness and softness.

The existing snake bone is formed by sequentially riveting a plurality of construction units, the processing cost is high, the assembly difficulty is high, the matching integrity is poor, the angle control precision is low, the length of the snake bone, which invades the human body, is longer and longer along with the bending advancing of the snake bone, the radial deviation and the axial deviation of the snake bone are larger and larger, and the control precision of the flexible operation arm and the endoscope is further reduced. In particular, the surgical arm of a flexible robot often needs to be controlled in combination with an algorithm, and deviation in the length and angle of the snake bone can seriously affect the accuracy of the algorithm.

Patent CN113576379B provides a snake bone unit, a snake bone, an endoscope and a bending control method, which discloses that the attraction or repulsion of magnetic bodies of two adjacent snake bone units is adopted to realize the relative rotation between the two adjacent snake bone units. The driving mode has the advantages that bending of the snake bone structure along multiple directions can be realized by controlling magnetism of the magnetic bodies in the accommodating cavities of the adjacent two snake bone units, the defects are obvious, the magnetic acting force is a detachable connection mode, the environment is more complicated, and the loss rate is higher.

Therefore, according to the above situation, it is needed to provide a snake bone device with low processing and assembling difficulty, high control precision and long service life.

Disclosure of Invention

In order to solve the technical problems in the prior art, the utility model aims to provide a snake bone structure, a flexible insertion structure, a flexible detector and a flexible mechanical arm, wherein the snake bone structure is matched with a limiting structure through a spring sleeve 2; the design of the connection between the flexible body 1 and the spring sleeve 2, the pull cord 3 ensures an accurate control and a long service life of the flexible probe or flexible mechanical arm.

In order to achieve the above purpose, the utility model provides a snake bone structure, which comprises a bendable main body 1 formed by sequentially connecting a head end bone segment 1-1, a snake bone segment 1-2 and a tail end bone segment 1-3 which can rotate relatively, wherein spring sleeves 2 are uniformly distributed on the side wall of the bendable main body 1 along the circumferential direction; the head end and the tail end of the spring sleeve 2 are respectively connected with the head end condyle 1-1 and the tail end condyle 1-3;

a pull rope 3 is arranged in the spring sleeve 2 in a penetrating way; the head end of the pull rope 3 is connected with the head end condyle 1-1;

in any state of the snake bone structure, the spring sleeve 2 does not generate axial relaxation force.

Optionally, the side wall of the bendable body 1 is provided with a recess 1a for mounting a spring sleeve 2.

Optionally, the head end of the spring sleeve 2 and the head end of the pull rope 3 are connected with the head end condyle 1-1 through different connection points.

Optionally, the spring sleeve 2 is connected to the flexible body 1 by a plurality of connection points, and the distance between two consecutive connection points is less than or equal to the height of the snake bone segments 1-2.

Optionally, the plurality of connection points are on a straight line, and the straight line is in the same plane as the centerline of the spring sleeve 2, the centerline of the bendable body 1.

Optionally, the trailing end of the spring sleeve 2 extends beyond the trailing end condyle 1-3.

Optionally, the pull rope 3 is made of stainless steel or tungsten alloy.

Alternatively, 0.ltoreq.the opening width of the groove 1 a.ltoreq.the outer diameter of the spring sleeve 2; the depth of the groove 1a is larger than or equal to the outer diameter of the spring sleeve 2.

Optionally, one end of each snake bone segment 1-2 is provided with a limiting structure; the other end is provided with a buckle structure;

each buckle structure is rotatably inserted into the corresponding limit structure on the adjacent snake bone segment 1-2 to form a fit; and the gap 1-2a/b between each group of matched limiting structure and the buckling structure is (0-0.05) mm.

To achieve the above object, the present utility model also provides a probe insertion structure including a main pipe body and the snake bone structure connected to each other.

In order to achieve the above purpose, the utility model also provides a flexible detector, which comprises a handle, a detector inserting structure and a camera module which are connected in sequence.

In order to achieve the above purpose, the utility model also provides a flexible mechanical arm, which comprises a control structure, the flexible insertion structure and an end effector which are connected in sequence.

In the snake bone structure, the flexible inserting structure, the flexible detector and the flexible mechanical arm, the snake bone structure has a good axial limiting effect through the cooperation of the limiting structure and the clamping structure, and the cooperation of the spring sleeve 2 always in a stretching state effectively improves the fine control precision of the snake bone, and particularly can realize accurate control in a complex environment scene. The service life of the flexible detector can be prolonged through the staggered design of the connection points among the spring sleeve 2, the pull rope 3 and the flexible main body 1; meanwhile, through the extension design of the spring sleeve 2, the part exceeding the tail end bone segments 1-3 can release the acting force transmitted by the connecting points, so that the service life of the pull rope 3 is prolonged. The snake bone structure provided by the utility model has low processing difficulty and low assembly difficulty, and can solve the problems of high cost and low control precision of the flexible operation arm and the endoscope.

Drawings

In order to more clearly illustrate the embodiments of the present utility model or the technical solutions in the prior art, the drawings that are needed in the description of the embodiments or the prior art will be briefly described, and it is obvious that the drawings in the description below are some embodiments of the present utility model, and other drawings can be obtained according to the drawings without inventive effort for a person skilled in the art.

Fig. 1 is a schematic structural diagram of a snake bone structure according to embodiment 1 of the utility model;

FIG. 2 is a schematic diagram of a groove (the opening width of the groove is equal to or larger than the outer diameter of the spring sleeve 2);

FIG. 3 is a schematic diagram of a groove (the opening width of the groove is less than or equal to the outer diameter of the spring sleeve 2);

FIG. 4 is a schematic view of a preferred embodiment of the utility model for connecting snake bone segments;

FIG. 5 is a schematic view of a preferred embodiment of the utility model for connecting snake bone segments;

FIG. 6 is a schematic view of a preferred embodiment of the utility model for connecting snake bone segments;

FIG. 7 is a schematic view of a preferred embodiment of the utility model for connecting snake bone segments;

FIG. 8 is a view of a head end bone segment according to a preferred embodiment of the present utility model;

FIG. 9 is a view of a caudal bone node according to a preferred embodiment of the present utility model.

Reference numerals:

a bendable main body 1; a spring sleeve 2; a pull rope 3; head end condyle 1-1; 1-2 parts of snake bone segments; tail end condyle 1-3; a groove 1a; a first rotary accommodating groove 1-2.1; 1-2.2 parts of a first auxiliary limiting structure; a first rotation center part 1-2.3; 1-2.4 parts of a first main limiting structure; gaps 1-2a/b; a second rotary accommodating groove 1-2.5; 1 to 2.6 parts of a second auxiliary limiting structure; 1-2.7 parts of a second main limiting groove; a second rotation center part 1-2.8; 1-2.9 parts of a second main limiting structure; 1 to 2.10 portions of a second auxiliary limit groove; hooks 1-2.11; 1 to 2.12 portions of clamping grooves; a buckle structure 1-1a of the tail end condyle and a limit structure 1-3a of the tail end condyle.

Detailed Description

The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings and specific embodiments, and it is apparent that the described embodiments are some embodiments of the present utility model, but not all embodiments. All other embodiments, which can be made by those skilled in the art based on the embodiments of the utility model without making any inventive effort, are intended to be within the scope of the utility model.

In the description of the present utility model, it should be understood that the terms "first," "second," and the like are used for descriptive purposes only and are not to be construed as indicating or implying a relative importance or number of technical features indicated. Thus, a feature defining "a first" or "a second" may explicitly or implicitly include at least one such feature. In the description of the present utility model, the meaning of "plurality" means at least two, for example, two, three, etc., unless specifically defined otherwise.

The terms "center," "longitudinal," "transverse," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counter-clockwise," "axial," "radial," "circumferential," etc. refer to an orientation or positional relationship based on that shown in the drawings, merely for convenience of description and to simplify the description, and do not indicate or imply that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore should not be construed as limiting the utility model. Wherein, the "axial direction" in the present utility model refers to a direction parallel to the axis of the snake bone structure, and the "radial direction" refers to a direction around the axis of the snake bone structure.

In the present utility model, unless explicitly specified and limited otherwise, the terms "mounted," "connected," "secured," and the like are to be construed broadly and include, for example, either fixedly attached, detachably attached, or integrally formed; may be mechanically connected, may be electrically connected or may be in communication with each other; either directly, or through an intermediary, may be internal to the two elements or in an interactive relationship with the two elements, unless explicitly defined otherwise. The specific meaning of the above terms in the present utility model can be understood by those of ordinary skill in the art according to the specific circumstances.

The following description is given to further illustrate preferred embodiments of the snake bone structure, the flexible insertion structure, the flexible probe and the flexible mechanical arm with reference to the accompanying drawings, but the following description is not intended to limit the snake bone structure, the flexible insertion structure, the flexible probe and the flexible mechanical arm in the present utility model.

As shown in fig. 1, the present embodiment provides a snake bone structure, which comprises a bendable main body 1 formed by sequentially connecting a head end bone segment 1-1, a snake bone segment 1-2 and a tail end bone segment 1-3 which can rotate relatively; the side wall of the bendable main body 1 is uniformly distributed with spring sleeves 2 along the circumferential direction; the head end and the tail end of the spring sleeve 2 are respectively connected with the head end condyle 1-1 and the tail end condyle 1-3; a pull rope 3 is arranged in the spring sleeve 2 in a penetrating way, and the head end of the pull rope 3 is connected with the head end condyle 1-1. In this embodiment, the snake bone structure does not generate an axial diastolic force in any state of use of the spring sleeve 2.

It should be understood that the axial relaxation force refers to the force that is generated when the spring sleeve 2 is compressed and the spring returns to its natural state, and is called axial relaxation force.

Meanwhile, the spring sleeve 2 is in a stretching state when being connected with the bendable main body 1, the stretching amount is not lower than the stroke of the pull rope 3 when the bendable main body 1 is bent to the limit, when the bendable main body 1 deflects, one side of the spring sleeve 2 is lengthened, the other side of the spring sleeve 2 is shortened, the shortened spring sleeve 2 is still in a stretching state or an inelastic state, and axial stretching elastic force cannot be generated, and as the spring sleeve 2 continuously provides a shrinking force for the snake bone structure, the axial distance between the bone segments is kept stable, and therefore the control precision of the snake bone structure in the axial direction can be maintained in the deflection process. It will be appreciated that when the spring sleeve 2 is in a stretched or inelastic state at all times, the spring sleeve 2 facing a slight axial asymmetry can still achieve a precisely controlled effect.

The present embodiment also provides a flexible insertion structure comprising a main tube body (not shown) and the snake bone structure connected to each other. Further, this embodiment also provides a flexible probe (not shown), including a handle, the flexible insertion structure and the camera module that connect gradually. It should be understood that the flexible probe according to the embodiments of the present utility model includes, but is not limited to, an endoscope, and the present utility model is exemplified by the structural features of the snake bone structure, but those skilled in the art will appreciate that the snake bone structure can be applied to flexible probes in other medical and industrial fields.

As an embodiment, the flexible probe is an endoscope. The endoscope comprises an operating handle, a main pipe body, a snake bone structure and a lens module, wherein the operating handle, the main pipe body, the snake bone structure and the lens module are sequentially connected, the lens module is arranged at the far end of the snake bone structure, and the snake bone structure can be bent and enters a human body before the main pipe to peep at a pathological change condition of a preset position.

Further, the present embodiment also provides a flexible mechanical arm (not shown), including a control mechanism, a flexible insertion structure, and an end effector, which are sequentially connected. The end effector is arranged at the far end of the snake bone structure and can be an electrotome, an electrocoagulation forceps, a biopsy forceps, a hemostatic clamp, a stitching instrument, a needle holder and the like; the control mechanism controls movement of the flexible insertion structure to the operative position and may also control the end effector to perform a corresponding surgical procedure, such as hemostasis, resecting tissue, closing a wound, etc.

With continued reference to fig. 1, the head end of the spring sleeve 2 is connected to the head end condyle 1-1, where the connection is common in the art, and in this embodiment, a welding connection may be used. In addition, the connection point of the spring sleeve 2 and the tail end bone segment 1-3 is arranged at the tail end notch of the tail end bone segment 1-3. It will be appreciated that the point of attachment of the spring sleeve 2 to the caudal bone segments 1-3 at the caudal notch can increase the accuracy of control of the snake bone.

Optionally, the number of connection points of the spring sleeve 2 to the bendable body 1 is at least 2; it will be appreciated that the more connection points the tighter the connection of the spring sleeve 2 to the bendable body 1, the more accurate the control of the snake bone structure at each segment of the spring sleeve 2 can be while preventing falling off due to bending during use.

Preferably, the distance between the two adjacent connection points is smaller than or equal to the height of each snake bone segment 1-2, namely, at least one connection point is arranged on each snake bone segment 1-2, and it is understood that when at least one connection point is arranged on each snake bone segment 1-2, the control precision of each bone segment can be effectively improved, the adverse effect of the axial movement between the adjacent bone segments on the control is reduced, and in the bending process, each bone segment can deflect and bend at equal angles. Preferably, the distance between two continuous connection points is equal, and the positions of the connection points on each snake bone segment 1-2 are identical, so that the flexible main body 1 can be accurately and uniformly controlled in the bending process.

It is to be understood that the position of the connection point of the spring sleeve 2 and the snake bone segments 1-2 should be at the same position of each snake bone segment 1-2; if the snake bone is positioned at different positions, the control of the snake bone in the actual use process can be influenced by different acting force points and acting force directions.

Preferably, the plurality of connection points of the spring sleeve 2 and the snake bone segments 1-2 are on the same straight line, and the straight line is in the same plane with the center line of the spring sleeve 2 and the center line of the bendable main body 1. It will be appreciated that the spring force generated by the spring sleeve 2, the force exerted by each snake bone joint 1-2 when the flexible body 1 is bent, is uniform when the connection points are in a line, so that precise control is achieved during actual use.

In another embodiment, the spring sleeve 2 may be optionally disposed on the inner side wall, the outer side wall, or between the walls of the flexible body 1. Likewise, the spring sleeves 2 distributed symmetrically in the circumferential direction may be disposed on the inner side wall, the outer side wall or between the walls of the bendable main body 1, respectively; alternatively, if the symmetrically distributed spring sleeves 2 are respectively disposed on different side walls of the bendable main body 1, there is slight asymmetry in the spring sleeves 2 that are originally symmetrically distributed, but the slight asymmetry does not affect the precise control degree in the subsequent practical use process in the present utility model. It should be understood that the sidewall of the flexible body 1 has a certain thickness, and that the "wall-to-wall" means that the spring sleeve 2 is disposed inside the sidewall of the flexible body 1; by "inner side wall" or "outer side wall" is meant that the spring sleeve 2 is arranged outside the side wall of the bendable body 1.

The snake bone structure is controlled in the detection process through the spring sleeve 2 and the pull rope 3 penetrating through the spring sleeve 2. Optionally, the snake bone structure can be controlled by two spring sleeves 2 which are uniformly distributed in the circumferential direction and a pull rope 3 which is penetrated in the spring sleeve 2 to realize bidirectional deflection; the snake bone structure is controlled by four spring sleeves 2 which are uniformly distributed in the circumferential direction and a pull rope 3 which is penetrated in the spring sleeves 2 when the snake bone structure deflects in the four directions.

The head end of the pull rope 3 is connected with the head end condyle 1-1. Alternatively, the pull cord 3 may be attached to the head end condyle 1-1 by any means known to one skilled in the art, such as welding. Optionally, the connection point between the pull rope 3 and the head end condyle 1-1 and the connection point between the spring sleeve 2 and the head end condyle 1-1 may be the same connection point or different connection points; preferably, the two connection points are different connection points; it is further preferred that the connection point of the spring sleeve 2 to the cephalad condyle 1-1 is closer to the caudal condyle 1-3 than the connection point of the pull cord 3. It is understood that when the two connection points are different connection points, the connection strength among the pull rope 3, the spring sleeve 2 and the head end condyle 1-1 can be effectively increased, and the service life of the snake bone is prolonged.

Optionally, the spring sleeve 2 has a portion that extends beyond the trailing end condyle 1-3, it being understood that when the spring sleeve 2 is provided with a portion that extends beyond the trailing end condyle 1-3, the pull cord 3 is prevented from directly contacting the trailing end condyle 1-3, reducing wear of the pull cord 3; similarly, the part of the spring sleeve 2 exceeding the tail end bone segment 1-3 is in a non-elastic state, so that no elastic acting force exists on the connecting point of the spring sleeve 2 and the tail end bone segment 1-3, and acting force transmitted by the connecting point can be released slowly, so that the whole service life can be prolonged.

Likewise, the flexible main body 1, the spring sleeve 2 and the pull rope 3 can be made of stainless steel materials; in particular, in order to improve the breaking strength and the abrasion resistance of the pull cord 3, the material of the pull cord 3 may be selected from alloys such as tungsten alloy.

As shown in fig. 2-3, the side wall of the bendable body 1 is provided with a recess 1a for mounting the spring sleeve 2. It should be understood that the spring sleeve 2 can be sunk into the groove 1a, so that the overall external diameter of the snake bone is not affected, and the subsequent coating of the polymer protective layer is facilitated; at the same time, space restriction can be formed on the spring sleeve 2, and the spring sleeve 2 is prevented from being changed in a larger displacement in the bending process of the bendable main body 1.

Optionally, the opening width of the groove 1a is less than or equal to the outer diameter of the spring sleeve 2; the depth of the groove 1a is larger than or equal to the outer diameter of the spring sleeve 2. It should be understood that, when the depth of the groove 1a is greater than or equal to the outer diameter of the spring sleeve 2, the spring sleeve 2 may be installed in the groove 1a in a sinking manner, so as not to affect the subsequent coating of the polymer protection layer; similarly, if the subsequent polymer protective layer does not need to pay attention to whether the spring sleeve 2 affects the spring sleeve, the depth of the groove 1a may be smaller than or equal to the outer diameter of the spring sleeve 2. In addition, when the opening width of the groove 1a is smaller than or equal to the outer diameter of the spring sleeve 2, the spring sleeve 2 is prevented from being separated from the groove 1a in the bending process of the bendable main body 1, so that the situation that the snake bone cannot be controlled or accurately controlled is avoided; similarly, if the spring sleeve 2 and the groove 1a are connected in an additional manner, the spring sleeve 2 and the groove 1a will not be separated, and the opening width of the groove 1a is not required to be concerned, i.e. the opening width of the groove 1a may be large or small. Alternatively, the spring sleeve 2 may be connected to the recess 1a in any way, and the connection may be made by any connection method known to those skilled in the art, such as welding. It should be understood that if the opening width of the recess 1a is 0, the spring sleeve 2 is disposed between the walls of the side walls of the bendable main body 1.

As shown in fig. 4-7, the head end condyle 1-1, the snake condyle 1-2 and the tail end condyle 1-3 are sequentially connected in a relatively rotatable manner.

One end of each snake bone segment 1-2 is provided with a limiting structure, and the other end of each snake bone segment is provided with a clamping structure; each buckle structure is rotatably inserted into the corresponding limit structure on the adjacent snake bone segment 1-2 to form a fit.

As shown in fig. 4, in this embodiment, the limiting structure includes a first rotary accommodating groove 1-2.1 and first auxiliary limiting structures 1-2.2 disposed at two sides of the rotary accommodating groove; the buckling structure comprises a first rotary central part 1-2.3 and first main limiting structures 1-2.4 arranged on two sides of the rotary central part.

The rotation center part is rotatably inserted into the corresponding rotation receiving groove of the adjacent one of the snake bone segments 1-2, and the rotation center part is deflectable in the rotation receiving groove, thereby realizing deflection of the whole bendable body. It should be understood that a gap 1-2a/b is provided between the first main limiting structure 1-2.4 and the first auxiliary limiting structure 1-2.2, where the gap 1-2a/b is one of factors affecting the bending degree of the bendable main body 1, and at the same time, ensures the overall accuracy, and considering the elastic force of the spring sleeve 2, the size of the gap 1-2a/b is (0-0.05) mm, which means that the size of the gap 1-2a/b is not greater than 0.05mm, and is not 0mm.

As shown in fig. 5-6, as another embodiment, the limit structure includes a second rotation receiving groove 1-2.5, a second auxiliary limit structure 1-2.6 disposed at both sides of the second rotation receiving groove 1-2.5, and a second main limit groove 1-2.7; the buckling structure comprises a second rotary central part 1-2.8, second auxiliary limiting grooves 1-2.10 and second main limiting structures 1-2.9, wherein the second auxiliary limiting grooves are arranged on two sides of the second rotary central part 1-2.8.

The second rotation center part 1-2.8 is rotatably inserted into the corresponding second rotation accommodation groove 1-2.5 on the adjacent one of the snake bone segments 1-2, and the second rotation center part 1-2.8 is deflectable within the second rotation accommodation groove 1-2.5, thereby realizing deflection of the whole bendable body. The second auxiliary limiting structure 1-2.6 is matched with the second auxiliary limiting groove 1-2.10; the second main limiting structure 1-2.9 is matched with the second main limiting groove 1-2.7.

It should be understood that a gap 1-2a/b is provided between the second main limiting structure 1-2.9 and the second main limiting groove 1-2.7, where the gap 1-2a/b is one of factors affecting the bending degree of the bendable main body 1, and at the same time, ensures the overall accuracy, and considering the elastic force of the spring sleeve 2, the size of the gap 1-2a/b is (0-0.05) mm, which means that the size of the gap 1-2a/b is not greater than 0.05mm, and is not 0mm.

As another embodiment, as shown in fig. 7, the second main limiting structure 1-2.9 and the second auxiliary limiting structure 1-2.6 are respectively provided with a hook 1-2.11 and a clamping groove 1-2.12; when the second rotary central part 1-2.8 deflects to a certain extent in the second rotary accommodating groove 1-2.5, the hooks 1-2.11 are matched with the clamping grooves 1-2.12, so that adjacent bones can be limited in the axial direction; and simultaneously, the gaps 1-2a/b between the second main limiting structures 1-2.9 and the second main limiting grooves 1-2.7 are matched, so that the stress intensity of the snake bone structure in the bending direction is effectively improved through combination of the two modes, and the reliability of the bendable main body in bending is ensured.

As shown in fig. 8-9, a limiting structure or a buckling structure (1-1 a) is arranged at one end of the head end condyle 1-1, which is adjacent to the snake condyle 1-2; correspondingly, only one end of the tail end condyle 1-3 adjacent to the snake condyle 1-2 is provided with another buckling structure or limiting structure (1-3 a) which can be matched with the head end condyle 1-1.

Finally, it should be noted that: the above embodiments are only for illustrating the technical solution of the present utility model, and not for limiting the same; although the utility model has been described in detail with reference to the foregoing embodiments, it will be understood by those of ordinary skill in the art that: the technical scheme described in the foregoing embodiments can be modified or some or all of the technical features thereof can be replaced by equivalents; such modifications and substitutions do not depart from the spirit of the utility model.

Claims (12)

1. A snake bone structure comprises a bendable main body formed by sequentially connecting a head end bone segment, a plurality of snake bone segments and a tail end bone segment which can rotate relatively, and is characterized in that,

spring sleeves are uniformly distributed on the side wall of the bendable main body along the circumferential direction; the head end and the tail end of the spring sleeve are respectively connected with the head end condyle and the tail end condyle;

a pull rope is arranged in the spring sleeve in a penetrating way; the head end of the pull rope is connected with the head end condyle;

the snake bone structure does not generate axial relaxation elastic force in any state.

2. A snake bone structure according to claim 1, wherein the side walls of the flexible body are provided with grooves for mounting the spring sleeve.

3. A snake bone structure according to claim 1 or 2, wherein the head end of the spring sleeve and the head end of the pull cord are connected to the head end condyle by different connection points.

4. A snake bone structure according to claim 1 or 2, wherein the spring sleeve is connected to the flexible body by a plurality of connection points, and the distance between two consecutive connection points is less than or equal to the height of each snake bone node.

5. The snake bone structure of claim 4, wherein the plurality of connection points are on a straight line and the straight line is in the same plane as the spring sleeve centerline, the bendable body centerline.

6. A snake bone structure according to claim 1 or 2, wherein the tail end of the spring sleeve extends beyond the tail end condyle.

7. A snake bone structure according to claim 1 or 2, wherein the pull rope is made of stainless steel or tungsten alloy.

8. A snake bone structure according to claim 2, wherein the opening width of the groove is 0-or-less than the outer diameter of the spring sleeve; the depth of the groove is more than or equal to the outer diameter of the spring sleeve.

9. A snake bone structure according to claim 1 or 2, wherein one end of the snake bone joint is provided with a limit structure; the other end is provided with a buckle structure;

each buckle structure is rotatably inserted into the corresponding limit structure on the adjacent snake bone segment to form a fit; and the gap between each group of matched limiting structure and the clamping structure is (0-0.05) mm.

10. A flexible insertion structure comprising interconnected main tubular bodies and a snake bone structure according to any of claims 1-9.

11. A flexible probe comprising a handle, a flexible insertion structure according to claim 10, and a camera module connected in sequence.

12. A flexible mechanical arm comprising a control structure, a flexible insertion structure according to claim 10, and an end effector connected in sequence.