Connection structure between the tip and the curved section and endoscope

Abstract

A connection structure (100) between a tip portion and a bending portion and an endoscope, wherein the connection structure (100) between a tip portion and a bending portion includes a tip portion (110) and a bending portion (120), the tip portion (110) is provided with a first engagement portion (111) that is located in the circumferential direction of the tip portion (110), the bending portion (120) is fitted with the tip portion (110), and the bending portion (120) is provided with a second engagement portion (115) that is located in the circumferential direction of the bending portion (120), the first engagement portion (111) snap-fits into the second engagement portion (115), and the tip portion (110) is connected to the bending portion (120). The connection structure (100) between the tip portion and the bending portion and the endoscope described above are easily attached by snap-fit ​​connection, are suitable for connecting the bending portion (120) made of plastic material and the tip portion (110), and are advantageous in terms of ease of operation in connecting the bending portion (120) and the tip portion (110). In addition, the first fastening portion (111) is provided in the circumferential direction of the tip portion (110), and the second fastening portion (115) is provided in the circumferential direction of the bending portion (120), which can improve the connection stability between the tip portion (110) and the bending portion (120) after the two are connected, and is also advantageous in preventing the tip portion (110) from falling off the bending portion (120), improving the reliability of the endoscope and reducing the probability of medical accidents.

Description

Technical Field

[0001] The present invention relates to the technical field of medical devices, and particularly to a connection structure between a distal end portion and a bending portion and an endoscope.

Background Art

[0002] With the development of medical technology, endoscope technology has emerged. An endoscope is used for visual inspection of inaccessible places such as organs inside the human body in order to observe the situation of pathological changes. Usually, an endoscope includes a long insertion tube, has a handle at one end close to the operator of the insertion tube, and has a visual inspection device such as a built-in camera at the distal end of the long insertion tube. In order to operate the endoscope inside the human body, the endoscope includes a bendable bending portion, and the direction of the distal end portion at the end of the bending portion is adjusted by the bending of the bending portion to change the observation viewing angle.

[0003] In the prior art, in order to realize the adjustment of the direction of the distal end portion of the endoscope, it is necessary to connect the plastic distal end portion to the bending portion. The connection method between the distal end portion and the bending portion of the conventional endoscope is mainly adhesion. However, since the adhesion performance of the material adopted for the bending portion is extremely poor, the distal end portion is likely to fall off from the bending portion due to adhesion, the reliability is poor, and it may cause medical accidents.

Summary of the Invention

Problems to be Solved by the Invention

[0004] Based on this, there is a need to provide a connection structure between a distal end portion and a bending portion and an endoscope that can effectively improve the connection stability between the distal end portion and the bending portion and reduce the occurrence probability of medical accidents.

Means for Solving the Problems

[0005] [[ID=三十二]] The connection structure between the tip and the curved portion includes the tip and the curved portion, the tip is provided with a first engaging portion which is located in the circumferential direction of the tip, the curved portion is fitted with the tip, and the curved portion is provided with a second engaging portion which is located in the circumferential direction of the curved portion, the first engaging portion snaps into the second engaging portion, and the tip is connected to the curved portion.

[0006] The above-described connection structure between the tip and the curved section connects the tip to the curved section by snap-fitting the first engagement part on the tip to the second engagement part on the curved section during the attachment process. The snap-fit ​​connection is convenient for attachment, suitable for connecting a curved section and a tip made of plastic material, and advantageous in improving the ease of operation of connecting the curved section and the tip. The first engagement part is provided in the circumferential direction of the tip, and the second engagement part is provided in the circumferential direction of the curved section. After the two are connected, the stability of the connection between the tip and the curved section can be improved, further preventing the tip from detaching from the curved section, improving the reliability of the endoscope, and reducing the probability of medical accidents.

[0007] In one embodiment, there are at least two of each of the first and second engaging portions, the at least two first engaging portions are spaced apart along the circumferential direction of the tip portion, the at least two second engaging portions are spaced apart along the circumferential direction of the curved portion, and the at least two first engaging portions are provided in a one-to-one correspondence with the at least two second engaging portions.

[0008] In one embodiment, the first engaging portion is an engaging column, the second engaging portion is an engaging hole, and the cross-sectional contour of the engaging column matches the opening shape of the engaging hole.

[0009] In one embodiment, the first engaging portion is an engaging hole, the second engaging portion is an engaging column, and the opening shape of the engaging hole matches the cross-sectional contour of the engaging column.

[0010] In one embodiment, the locking column is provided with an inclined surface, which is used to guide the locking column into the locking hole.

[0011] In one embodiment, at least two of the engaging posts include at least a first engaging post and a second engaging post, and at least two of the engaging holes include at least a first engaging hole and a second engaging hole, the first engaging post snaps into the first engaging hole, the second engaging post snaps into the second engaging hole, the cross-sectional profile of the first engaging post differs from the cross-sectional profile of the second engaging post, and the opening shape of the first engaging hole differs from the opening shape of the second engaging hole.

[0012] In one embodiment, the cross-sectional contour of the first engaging column extends along the axial direction of the tip portion. elongated hole The opening shape of the first engagement hole extends along the axial direction of the curved portion. elongated hole The cross-sectional contour of the second engaging column is circular, and the opening shape of the second engaging hole is circular.

[0013] In one embodiment, the tip portion is provided with a first annular connecting portion, the first annular connecting portion is connected to the tip portion and extends along the axial direction of the tip portion, the curved portion is provided with a second annular connecting portion, the second annular connecting portion is connected to the curved portion and extends along the axial direction of the curved portion, the first engaging portion is located in the circumferential direction of the first annular connecting portion, the second engaging portion is located in the circumferential direction of the second annular connecting portion, the outer diameter of the first annular connecting portion is smaller than the inner diameter of the second annular connecting portion, the second annular connecting portion is fitted onto the first annular connecting portion, the tip portion is joined to the second annular connecting portion, and the outer wall of the tip portion smoothly transitions with the outer wall of the second annular connecting portion.

[0014] In one embodiment, a sealant is applied between the outer wall of the first annular connection and the inner wall of the second annular connection.

[0015] In one embodiment, the tip portion is provided with a first annular connecting portion, the first annular connecting portion is connected to the tip portion and extends along the axial direction of the tip portion, the curved portion is provided with a second annular connecting portion, the second annular connecting portion is connected to the curved portion and extends along the axial direction of the curved portion, the first engaging portion is located in the circumferential direction of the first annular connecting portion, the second engaging portion is located in the circumferential direction of the second annular connecting portion, the outer diameter of the second annular connecting portion is smaller than the inner diameter of the first annular connecting portion, the first annular connecting portion is detached from the second annular connecting portion, the curved portion is joined to the first annular connecting portion, and the outer wall of the curved portion transitions smoothly with the outer wall of the first annular connecting portion.

[0016] In one embodiment, a sealant is applied between the outer wall of the second annular connection and the inner wall of the first annular connection.

[0017] The endoscope includes a connecting structure between the tip and the bending section as described in any one of the above items.

[0018] The above-mentioned endoscope connects the tip to the curved section by snap-fitting the first locking portion at the tip to the second locking portion at the curved section during the attachment process. The snap-fit ​​connection is convenient for attachment, suitable for connecting the curved section and tip made of plastic material, and advantageous in improving the ease of operation of the connection between the curved section and the tip. The first locking portion is provided circumferentially on the tip, and the second locking portion is provided circumferentially on the curved section. After the two are connected, the stability of the connection between the tip and the curved section can be improved, further preventing the tip from detaching from the curved section, improving the reliability of the endoscope and reducing the probability of medical accidents.

[0019] The drawings, which constitute part of this application, are used to provide a further understanding of the present invention, and the schematic embodiments and descriptions of the present invention are used to interpret the present invention and do not constitute an unreasonable limitation to the present invention. To more clearly illustrate the technical solutions in the embodiments of the present invention, the following is a brief introduction to the drawings that may be used in the description of the embodiments. Clearly, the drawings in the following description represent only some embodiments of the present invention, and those skilled in the art can obtain other drawings from these without any creative work. [Brief explanation of the drawing]

[0020] [Figure 1] This is a schematic diagram of the connection structure between the tip and the curved portion according to one embodiment. [Figure 2] This is a schematic diagram of the combination of connection structures between the tip and curved sections according to one embodiment. [Figure 3] Figure 2 is an enlarged schematic diagram of the structure at circle A. [Modes for carrying out the invention]

[0021] To better understand the above-mentioned objectives, features, and advantages of the present invention, specific embodiments of the present invention will be described in detail below with reference to the drawings. In the following description, many specific details will be explained in order to fully understand the present invention. However, the present invention can be carried out in many other forms different from the embodiments described herein, and those skilled in the art can make similar improvements without departing from the spirit of the invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0022] In the description of the present invention, it should be understood that terms such as "center", "vertical direction", "horizontal direction", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial direction", "radial direction", "circumferential direction", etc. indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the purpose of making it easier to explain the present invention and simplifying the description, and do not mean or imply that the mentioned device or element must have a specific orientation and must be configured and operated in a specific orientation, and should not be construed as limiting the present invention.

[0023] In addition, the terms "first" and "second" are only for the purpose of description, and do not mean or imply relative importance or imply the number of the described technical features. Therefore, the features defined by "first" and "second" can include at least one of the features explicitly or implicitly. In the description of the present invention, unless specifically and explicitly limited, the meaning of "plural" is at least two, for example, two, three, etc.

[0024] In the present invention, unless specifically defined and limited, terms such as "attachment", "connection", "connection", "fixation", etc. should be understood in a broad sense. For example, it may be a fixed connection, a detachable connection, or integrated. Also, it may be mechanically connected or electrically connected. Also, it may be directly connected or indirectly connected through an intermediate medium, or it may be the communication inside two elements or the interaction relationship between two elements. The specific meaning of the above terms in the present invention will be understood by those skilled in the art according to the specific situation.

[0025] In the present invention, unless otherwise specifically defined and limited, the presence of a first feature "above" or "below" a second feature may mean that the first and second features are in direct contact, or that they are indirectly in contact via an intermediate medium. Furthermore, the presence of a first feature "above," "above," and "on the top surface" of a second feature may simply mean that the first feature is directly above or diagonally above the second feature, or that the horizontal height of the first feature is greater than that of the second feature. The presence of a first feature "below," "below," and "on the bottom surface" of a second feature may simply mean that the first feature is directly below or diagonally below the second feature, or that the horizontal height of the first feature is less than that of the second feature.

[0026] When one element is described as being "fixed" or "attached" to another element, it may be directly present in the other element, or there may be an intervening element. When one element is considered to be "connected" to another element, it may be directly connected to the other element, or there may be an intervening element. The terms "vertical," "horizontal," "up," "down," "left," "right," and similar expressions used herein are for illustrative purposes only and do not represent only one embodiment.

[0027] In one embodiment, referring to Figures 1, 2, and 3, the connection structure 100 between the tip and the curved portion includes a tip 110 and a curved portion 120. The tip 110 is provided with a first engagement portion 111, which is located in the circumferential direction of the tip 110. The curved portion 120 is fitted with the tip 110, and the curved portion 120 is provided with a second engagement portion 121, which is located in the circumferential direction of the curved portion 120. The first engagement portion 111 snaps into place with the second engagement portion 121, and the tip 110 is connected to the curved portion 120.

[0028] The above-described connection structure 100 between the tip and the curved section connects the tip 110 to the curved section 120 by snap-fitting the first engagement portion 111 on the tip 110 to the second engagement portion 121 on the curved section 120 during the attachment process. The snap-fit ​​connection is convenient for attachment, suitable for connecting the plastic curved section 120 to the tip 110, and advantageous in improving the ease of operation of connecting the curved section 120 to the tip 110. The first engagement portion 111 is provided in the circumferential direction of the tip 110, and the second engagement portion 121 is provided in the circumferential direction of the curved section 120. After the two are connected, the connection stability between the tip 110 and the curved section 120 can be improved, and furthermore, the tip 110 will not detach from the curved section 120, improving the reliability of the endoscope and reducing the probability of medical accidents.

[0029] Furthermore, referring to Figures 1 and 2, there are at least two first engaging portions 111 and two second engaging portions 121, with at least two first engaging portions 111 spaced apart along the circumferential direction of the tip portion 110, and at least two second engaging portions 121 spaced apart along the circumferential direction of the curved portion 120.

[0030] Specifically, referring to Figures 2 and 3, there are four first engagement portions 111, which are spaced apart along the circumferential direction of the tip portion 110, and there are four second engagement portions 121, which are spaced apart along the circumferential direction of the curved portion 120. This arrangement is advantageous in improving the ease of operation of the snap-fit ​​connection and making it convenient to attach the tip portion 110, while also being advantageous in distributing stress at the connection point, improving the circumferential connection stability between the curved portion 120 and the tip portion 110, preventing loosening and detachment of the tip portion 110, and further preventing medical accidents during endoscopic examinations. In this embodiment, only one type of selection for the number of first engagement portions 111 and second engagement portions 121 is provided, but the invention is not limited to this.

[0031] Furthermore, referring to Figures 2 and 3, at least two first engagement portions 111 are provided in one-to-one correspondence with at least two second engagement portions 121. This is advantageous in further improving the circumferential connection stability between the curved portion 120 and the tip portion 110.

[0032] In one embodiment, referring to Figures 2 and 3, the first engagement portion 111 is an engagement column 112, and the second engagement portion 121 is an engagement hole 122, with the cross-sectional contour of the engagement column 112 matching the opening shape of the engagement hole 122. This connection between the engagement column 112 and the engagement hole 122 is advantageous in ensuring the stability of the snap-fit ​​connection, and the matching shapes of the engagement column 112 and engagement hole 122 are advantageous in avoiding loosening, further improving the overall quality of the endoscope.

[0033] Alternatively, in other embodiments (not shown), the first engagement portion 111 is an engagement hole 122, and the second engagement portion 121 is an engagement column 112, where the opening shape of the engagement hole 122 matches the cross-sectional contour of the engagement column 112. This connection between the engagement column 112 and the engagement hole 122 is advantageous in ensuring the stability of the snap-fit ​​connection, and the matching shapes of the engagement column 112 and engagement hole 122 are advantageous in avoiding loosening, further improving the overall quality of the endoscope.

[0034] Furthermore, referring to Figures 2 and 3, the engagement column 112 is provided with an introduction slope 113, which is used to guide the engagement column 112 into the engagement hole 122. In this way, when the curved section 120 is connected to the tip section 110, it is convenient for the engagement column 112 to enter the engagement hole 122, improving the convenience of the snap-fit ​​connection between the tip section 110 and the curved section 120.

[0035] In one embodiment, referring to Figures 2 and 3, at least two engagement posts 112 include at least a first engagement post 114 and a second engagement post 115, and at least two engagement holes 122 include at least a first engagement hole 123 and a second engagement hole 124. The first engagement post 114 snaps into the first engagement hole 123, and the second engagement post 115 snaps into the second engagement hole 124. The cross-sectional contour of the first engagement post 114 differs from that of the second engagement post 115, and the opening shape of the first engagement hole 123 differs from that of the second engagement hole 124. By distinguishing the different shapes of the first engagement post 114 and the second engagement post 115 in this way, it is advantageous that the tip portion 110 is connected to the curved portion 120 in a certain direction, avoiding misaligned connection between the tip portion 110 and the curved portion 120, and thus improving the overall quality of the endoscope.

[0036] Specifically, there are two first engagement posts 114 and two second engagement posts 115, with the two first engagement posts 114 and the two second engagement posts 115 being installed adjacent to each other. Correspondingly, there are two first engagement holes 123 and two second engagement holes 124, with the two first engagement holes 123 and the two second engagement holes 124 being installed adjacent to each other. In this way, the tip portion 110 is prevented from being installed inverted during attachment, and furthermore, the convenience and efficiency of attaching the tip portion 110 are improved.

[0037] In one embodiment, referring to Figures 1, 2, and 3, the cross-sectional contour of the first engaging column 114 extends along the axial direction of the tip portion 110. elongated hole The opening shape of the first engagement hole 123 extends along the axial direction of the curved portion 120. elongated hole The cross-sectional contour of the second engagement column 115 is circular, and the opening shape of the second engagement hole 124 is circular. In this embodiment, only one type of shape selection for the engagement column 112 and the engagement hole 122 is provided, but the embodiment is not limited to this.

[0038] Furthermore, to understand and explain the axial direction of the tip portion 110, using Figure 3 as an example, the axial direction of the tip portion 110 is the direction indicated by one of the arrows on the straight line S1 in Figure 3. Note that the curved portion 120 and the tip portion 110 are connected coaxially.

[0039] Specifically, referring to Figures 1, 2, and 3, the tip portion 110 is made of PC (polycarbonate), and the curved portion 120 is made of POM (polymethanol). Thus, the manufacturing material cost is low, and it is non-toxic and harmless, which is advantageous in reducing production costs and improving the economic effect of the product, while at the same time avoiding secondary injuries such as allergies and improving the quality of use of the endoscope. In this embodiment, only one type of material selection for the tip portion 110 and the curved portion 120 is provided, but it is not limited to this.

[0040] In one embodiment, referring to Figures 2 and 3, the tip portion 110 is provided with a first annular connecting portion 116, which is connected to the tip portion 110 and extends along the axial direction of the tip portion 110. The curved portion 120 is provided with a second annular connecting portion 125, which is connected to the curved portion 120 and extends along the axial direction of the curved portion 120. The first engaging portion 111 is located in the circumferential direction of the first annular connecting portion 116, and the second engaging portion 121 is located in the circumferential direction of the second annular connecting portion 125, and the outer diameter of the first annular connecting portion 116 is smaller than the inner diameter of the second annular connecting portion 125. The second annular connector 125 is fitted onto the first annular connector 116, and the tip 110 is joined to the second annular connector 125, with the outer wall of the tip 110 smoothly transitioning to the outer wall of the second annular connector 125. In this way, after the curved portion 120 is connected to the tip 110, the outer walls of both transition smoothly, which is advantageous in improving the smoothness of the structure, avoiding damage to organ tissue when entering human organs, and further improving the overall quality of use of the endoscope.

[0041] Furthermore, sealant is applied between the outer wall of the first annular connector 116 and the inner wall of the second annular connector 125. In this manner, the first annular connector 116 and the second annular connector 125 are connected in a manner that aids adhesion by snap-fitting, which is advantageous in further improving the connection stability between the tip portion 110 and the bending portion 120, further preventing the tip portion 110 from detaching from the bending portion 120, ensuring airtightness, and further improving the overall quality of the endoscope.

[0042] Alternatively, in another embodiment, the tip portion 110 is provided with a first annular connector 116, which is connected to the tip portion 110 and extends along the axial direction of the tip portion 110; the curved portion 120 is provided with a second annular connector 125, which is connected to the curved portion 120 and extends along the axial direction of the curved portion 120; the first engaging portion 111 is located in the circumferential direction of the first annular connector 116; the second engaging portion 121 is located in the circumferential direction of the second annular connector 125; the outer diameter of the second annular connector 125 is smaller than the inner diameter of the first annular connector 116; the first annular connector 116 is fitted onto the second annular connector 125; the curved portion 120 is joined to the first annular connector 116; and the outer wall of the curved portion 120 transitions smoothly with the outer wall of the first annular connector 116. Thus, after the curved section 120 is connected to the tip section 110, the outer walls of both sections transition smoothly, which is advantageous in improving the smoothness of the structure, avoiding damage to organ tissue when entering the human body, and further improving the overall quality of use of the endoscope.

[0043] Furthermore, sealant is applied between the outer wall of the second annular connector 125 and the inner wall of the first annular connector 116. In this way, the first annular connector 116 and the second annular connector 125 are connected in a manner that aids adhesion by snap-fitting, which is advantageous in further improving the connection stability between the tip portion 110 and the bending portion 120, further preventing the tip portion 110 from detaching from the bending portion 120, ensuring airtightness, and further improving the overall quality of the endoscope.

[0044] In one embodiment, the endoscope (not shown) includes a connecting structure 100 between the tip and the curved portion according to the above embodiment.

[0045] In the above-described endoscope, during the attachment process, the first attachment portion 111 on the tip portion 110 is snap-fitted to the second attachment portion 121 on the bending portion 120, thereby connecting the tip portion 110 to the bending portion 120. The snap-fit ​​connection is convenient for attachment, suitable for connecting the plastic bending portion 120 and the tip portion 110, and advantageous in improving the ease of operation of connecting the bending portion 120 and the tip portion 110. The first attachment portion 111 is provided in the circumferential direction of the tip portion 110, and the second attachment portion 121 is provided in the circumferential direction of the bending portion 120. After the two are connected, the stability of the connection between the tip portion 110 and the bending portion 120 can be improved, and furthermore, the tip portion 110 is prevented from detaching from the bending portion 120, improving the reliability of the endoscope and reducing the probability of medical accidents.

[0046] The technical features of the embodiments described above can be combined in any way, and for the sake of brevity, not all possible combinations of the technical features in the embodiments described above have been explained. However, as long as these combinations of technical features are not contradictory, they should be considered to fall within the scope described herein.

[0047] The above embodiments merely illustrate some of the embodiments of the present invention, and although the descriptions are specific and detailed, they should not be understood as limiting the scope of the invention. Those skilled in the art should note that several modifications and improvements within the scope of the present invention can be made without departing from the spirit of the present invention. Therefore, the scope of the patent of the present invention shall be as defined by the attached claims. [Explanation of Symbols]

[0048] 100 Connection structure between tip and curved section, 110 Tip section, 111 First engagement section, 112 Engagement column, 113 Induction slope, 114 First engagement column, 115 Second engagement column, 116 First annular connection section, 120 Curved section, 121 Second engagement section, 122 Engagement hole, 123 First engagement hole, 124 Second engagement hole, 125 Second annular connection section

Claims

1. A connection structure between the tip and the curved part, including the tip and the curved part, The tip portion is provided with a first engagement portion, and the first engagement portion is located in the circumferential direction of the tip portion. The curved portion is fitted with the tip portion, and the curved portion is provided with a second engaging portion, the second engaging portion is located in the circumferential direction of the curved portion, the first engaging portion snaps into the second engaging portion, and the tip portion is connected to the curved portion. The first engaging portion and the second engaging portion each consist of at least two of each, the at least two first engaging portions being spaced apart along the circumferential direction of the tip portion, the at least two second engaging portions being spaced apart along the circumferential direction of the curved portion, and the at least two first engaging portions being provided in one-to-one correspondence with the at least two second engaging portions. The first engagement portion is an engagement column, the second engagement portion is an engagement hole, the cross-sectional contour of the engagement column matches the opening shape of the engagement hole, in this case the tip portion is provided with a first annular connecting portion, the first annular connecting portion is connected to the tip portion and extends along the axial direction of the tip portion and is configured as a closed annulus, the curved portion is provided with a second annular connecting portion, the second annular connecting portion is connected to the curved portion and extends along the axial direction of the curved portion and is configured as a closed annulus The assembly is configured such that the engaging column is located in the circumferential direction of the first annular connection, the engaging hole is located in the circumferential direction of the second annular connection, the outer diameter of the first annular connection is smaller than the inner diameter of the second annular connection, the second annular connection is fitted onto the first annular connection, the tip is joined to the second annular connection, and the outer wall of the tip smoothly transitions with the outer wall of the second annular connection, and sealant is applied between the outer wall of the first annular connection and the inner wall of the second annular connection. Or, The first engaging portion is an engaging hole, the second engaging portion is an engaging column, the opening shape of the engaging hole matches the cross-sectional contour of the engaging column, in this case the tip portion is provided with a first annular connecting portion, the first annular connecting portion is connected to the tip portion and extends along the axial direction of the tip portion and is configured as a closed annulus, the curved portion is provided with a second annular connecting portion, the second annular connecting portion is connected to the curved portion and extends along the axial direction of the curved portion and is configured as a closed annulus, and the engaging portion A connection structure between a tip portion and a curved portion, characterized in that the mounting holes are located in the circumferential direction of the first annular connecting portion, the engaging columns are located in the circumferential direction of the second annular connecting portion, the outer diameter of the second annular connecting portion is smaller than the inner diameter of the first annular connecting portion, the first annular connecting portion is fitted onto the second annular connecting portion, the curved portion is joined to the first annular connecting portion, the outer wall of the curved portion transitions smoothly with the outer wall of the first annular connecting portion, and sealant is applied between the outer wall of the second annular connecting portion and the inner wall of the first annular connecting portion.

2. The connection structure of the tip portion and the curved portion according to claim 1, characterized in that the engagement column is provided with an introduction slope, and the introduction slope is used to guide the engagement column into the engagement hole.

3. The connection structure between a tip portion and a curved portion according to claim 1, characterized in that at least two of the engaging columns include at least a first engaging column and a second engaging column, at least two of the engaging holes include at least a first engaging hole and a second engaging hole, the first engaging column snaps into the first engaging hole, the second engaging column snaps into the second engaging hole, the cross-sectional contour of the first engaging column differs from the cross-sectional contour of the second engaging column, and the opening shape of the first engaging hole differs from the opening shape of the second engaging hole.

4. The connection structure between the tip portion and the curved portion according to claim 3, characterized in that the cross-sectional contour of the first engaging column is elongated and extends along the axial direction of the tip portion, the opening shape of the first engaging hole is elongated and extends along the axial direction of the curved portion, the cross-sectional contour of the second engaging column is circular, and the opening shape of the second engaging hole is circular.

5. An endoscope comprising a connection structure between a tip portion and a curved portion according to any one of claims 1 to 4.

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