Endoscope

Abstract

The endoscope (1) has a flexible tube (5) along a central axis (O). The flexible tube (5) has a plurality of convex surfaces (6) and concave surfaces (7) on its outer peripheral surface. The plurality of convex surfaces (6) are each surrounded by concave surfaces (7) and isolated from each other. In the case where the concave surface (7) includes a first portion (7c1) along an axial direction parallel to the central axis (O), the first portion (7c1) is formed discontinuously in the axial direction. In the case where the concave surface (7) includes a second portion (7c2) along a circumferential direction around the central axis (O), the second portion (7c2) is formed discontinuously in the circumferential direction.

Description

Technical Field

[0001] The present invention relates to an endoscope having a tubular flexible tube, the flexible tube being flexible. Background Technology

[0002] Corrugated pipes are known as flexible conduits. They possess a corrugated structure with alternating annular protrusions and annular recesses along a central axis along their length. Corrugated pipes can be manufactured inexpensively and are highly flexible, making them suitable for applications such as sheathing materials for electrical wires.

[0003] Furthermore, flexible endoscopes have an insertion portion configured as a flexible tube. In recent years, disposable endoscopes designed for single use have been proposed. From a cost perspective, disposable endoscopes are preferred as they can be manufactured at a low cost, and the use of corrugated tubes is under investigation.

[0004] For example, Japanese Patent Application Publication No. 9-066021 describes an endoscope with an inner tube in a corrugated shape in the curved section.

[0005] Generally, the required characteristics for the insertion part of an endoscope include flexibility, tensile strength, and torque resistance. Flexibility is well-known as the ability to bend. Tensile strength is the resistance to stretching and contraction. Specifically, tensile strength includes resistance to compression (resistance to compression) and resistance to tension (resistance to stretching). Torque resistance is the resistance to torsion about a central axis.

[0006] Corrugated pipes have a flexible structure and high torque resistance. However, due to their low expansion and contraction resistance, they will shrink under compressive force and elongate under tensile force.

[0007] Most of the aforementioned characteristics are in a trade-off relationship. Therefore, it is difficult for corrugated pipes with a corrugated structure to improve tensile and torque resistance while maintaining flexibility. In addition, it is also difficult to control the viscoelastic and other properties during bending more freely.

[0008] The present invention was made in view of the above circumstances, and its object is to provide an endoscope with a flexible tube that achieves a balance of flexibility, stretchability, and torque resistance and is manufactured at a low cost. Summary of the Invention

[0009] Methods for solving problems

[0010] An endoscope according to one aspect of the present invention includes a flexible tube, the flexible tube being a tube extending along a central axis from one end to the other, the flexible tube comprising: a plurality of convex surfaces disposed on an outer peripheral surface; and a concave surface disposed on the outer peripheral surface and defined by the plurality of convex surfaces, each of the plurality of convex surfaces being surrounded by the concave surface and isolated from each other, wherein the concave surface includes a first portion along an axial direction parallel to the central axis, the first portion being intermittently formed in the axial direction, and wherein the concave surface includes a second portion along a circumferential direction about the central axis, the second portion being intermittently formed in the circumferential direction.

[0011] An endoscope according to one aspect of the present invention includes a flexible tube, the flexible tube being a tube extending along a central axis from one end to the other, the flexible tube having: a plurality of convex surfaces disposed on an outer peripheral surface; and concave surfaces disposed on the outer peripheral surface and defined by the plurality of convex surfaces, each of the plurality of convex surfaces being surrounded by the concave surfaces and isolated from each other, the concave surfaces being all inclined relative to an axial direction parallel to the central axis and inclined relative to a circumferential direction about the central axis. Attached Figure Description

[0012] Figure 1 This is a diagram illustrating a structural example of the endoscope in the first embodiment of the present invention.

[0013] Figure 2 This is a perspective view showing an example of the flexible tube according to the first embodiment described above.

[0014] Figure 3 This is a perspective view showing a modified example of the flexible tube according to the first embodiment described above.

[0015] Figure 4 This is a diagram showing the structure when the outer peripheral surface of the flexible tube of the first embodiment described above is unfolded into a plane.

[0016] Figure 5 This is a diagram showing the structure when the outer peripheral surface of the flexible tube according to the second embodiment of the present invention is unfolded into a plane.

[0017] Figure 6 This is a perspective view of a flexible tube according to a third embodiment of the present invention.

[0018] Figure 7 This is a diagram showing the structure when the outer peripheral surface of the flexible tube of the third embodiment described above is unfolded into a plane.

[0019] Figure 8 This is a diagram showing the structure when the outer peripheral surface of the flexible tube according to the fourth embodiment of the present invention is unfolded into a plane.

[0020] Figure 9This is a diagram showing the structure when the outer peripheral surface of the flexible tube according to the fifth embodiment of the present invention is unfolded into a plane.

[0021] Figure 10 This is a diagram showing the structure when the outer peripheral surface of the flexible tube according to the sixth embodiment of the present invention is unfolded into a plane.

[0022] Figure 11 This is a diagram showing the structure when the outer peripheral surface of the flexible tube according to the seventh embodiment of the present invention is unfolded into a plane.

[0023] Figure 12 This is a diagram showing the structure when the outer peripheral surface of the flexible tube according to the eighth embodiment of the present invention is unfolded into a plane.

[0024] Figure 13 This is a diagram showing the structure when the outer peripheral surface of the flexible tube according to the ninth embodiment of the present invention is unfolded into a plane.

[0025] Figure 14 This is a diagram showing the structure when the outer peripheral surface of the flexible tube according to the tenth embodiment of the present invention is unfolded into a plane.

[0026] Figure 15 This is a perspective view showing the flexible tube according to the eleventh embodiment of the present invention.

[0027] Figure 16 This is a perspective view showing the flexible tube according to the twelfth embodiment of the present invention.

[0028] Figure 17 This is a perspective view showing the flexible tube according to the thirteenth embodiment of the present invention.

[0029] Figure 18 This is a cross-sectional view showing the first connection structure between the tube and the rigid component in the related art.

[0030] Figure 19 This is a cross-sectional view showing the second connection structure between the tube and the rigid component in the related art.

[0031] Figure 20 This is a cross-sectional view showing the third connection structure between the tube and the rigid component in the related technology.

[0032] Figure 21 This is a cross-sectional view showing the fourth connection structure between the tube and the rigid component in the related technology.

[0033] Figure 22 This is a cross-sectional view showing the fifth connection structure between the tube and the rigid component in the related technology.

[0034] Figure 23 This is a cross-sectional view showing the sixth connection structure between the tube and the rigid component in the related technology.

[0035] Figure 24 This is a cross-sectional view showing the seventh connection structure between the tube and the rigid component in the related technology.

[0036] Figure 25 This is a cross-sectional view showing the eighth connection structure between a tube and a rigid component in the related art.

[0037] Figure 26 This is a diagram illustrating the manufacturing method of the tube involved in the ninth connection structure between the tube and the rigid component in the related art. Detailed Implementation

[0038] In the following description, embodiments of the present invention will be described with reference to the accompanying drawings. However, the present invention is not limited to the embodiments described below.

[0039] Furthermore, in the accompanying drawings, identical or corresponding elements are appropriately labeled with the same reference numerals. It should also be noted that the drawings are illustrative; for the sake of simplicity, the length relationships, length ratios, and quantities of elements within a drawing may sometimes differ from reality. Moreover, multiple drawings may sometimes contain differences in length relationships, ratios, quantities, etc., between each other.

[0040] [First Implementation Method]

[0041] Figures 1 to 4 This represents the first embodiment of the present invention. Figure 1 This is a diagram showing an example of the structure of the endoscope 1 in the first embodiment.

[0042] Endoscope 1 is a device for observing and treating a subject. Endoscope 1 includes: an insertion part 2 that is inserted into the subject, an operating part 3 located at the base of the insertion part 2, and a universal cable 4 extending from the operating part 3.

[0043] Furthermore, the object to be examined inserted into the insertion section 2 is assumed to be a living organism such as a human or animal, but is not limited to this; it can also be a non-living object such as machinery or a building. Additionally, the endoscope 1 can be an automatically inserted endoscope that advances and retracts by rotation. The endoscope 1 can be any of the following: an upper digestive organ endoscope, a lower digestive organ endoscope, or an endoscope used in other locations.

[0044] The insertion part 2 has a front end 2a, a curved part 2b and a tubular part 2c in sequence from the front end toward the base end.

[0045] The front end 2a includes, for example, an observation system and an illumination system. The illumination system includes an illumination optics system, which illuminates the subject with illumination light. The observation system includes an objective lens optics system and an imaging element inside the observation window. The observation system uses the objective lens optics system to image the reflected light from the subject and captures an image using the imaging element.

[0046] The bending portion 2b is provided at the base end of the front end portion 2a, and is configured to be able to bend in two directions (up and down) or in four directions (up, down, left, and right). When the bending portion 2b bends, the direction of the front end portion 2a changes, and the observation direction of the observation system and the illumination direction of the illumination system change. In addition, the bending portion 2b is also bent to improve the insertability of the insertion portion 2 within the subject.

[0047] The tubular portion 2c is a tubular section that connects the base end of the curved portion 2b to the front end of the operating portion 3. The tubular portion 2c has a flexible shape that flexes according to the shape of the inserted object. In this case, the endoscope 1 is referred to as a flexible endoscope.

[0048] The operating part 3 is located at the base of the insertion part 2 and is used to perform various operations related to the endoscope 1 by hand. The operating part 3 includes, for example, a grip 3a, a bending operation knob 3b, multiple operation buttons 3c, and a treatment instrument insertion port 3d.

[0049] The holding part 3a is the part where the operator holds the endoscope 1 with their palm.

[0050] The bending operation knob 3b is, for example, an operating device for bending the bending part 2b using the thumb of the hand holding the handle 3a. When the bending part 2b can be bent in four directions (up, down, left, and right), the bending operation knob 3b includes a UD bending operation knob 3b1 for bending in the up and down direction and an RL bending operation knob 3b2 for bending in the left and right direction.

[0051] Multiple operation buttons 3c include, for example, the air / water supply button 3c1, the suction button 3c2, and other button types 3c3, etc.

[0052] The air and water supply button 3c1 is used to clean the observation window by supplying air and water to the observation window located on the front face of the observation system via an air and water supply channel (not shown).

[0053] The suction button 3c2 is used to perform the following operations: suctioning fluids, mucous membranes, etc. from the subject body via a suction channel (not shown).

[0054] Other button types in 3c3 include freeze buttons for temporarily pausing the monitor display, release buttons for capturing still images, and toggle buttons for switching to special lighting.

[0055] The instrument insertion port 3d is located on the side of the front end of the gripping part 3a. The instrument insertion port 3d communicates with the instrument channel. The instrument channel has a front end opening at its front end 2a. When various instruments such as forceps are inserted into the instrument insertion port 3d, the front end of the instrument protrudes from the front end opening of the instrument channel, enabling various treatments to be performed on the subject.

[0056] The universal cable 4 extends, for example, from the side of the base end of the operating unit 3. A connector 4a is provided at the extended end of the universal cable 4. The connector 4a is connected to an endoscope processor and a light source device (or an endoscope processor that also serves as a light source device), which are not shown.

[0057] The endoscope processor sends drive signals and power to the imaging element located in the anterior end portion 2a. Furthermore, the endoscope processor receives imaging signals obtained by capturing images of the subject using the imaging element. The light source device emits illumination light, which is transmitted via a light guide (not shown). The illumination light transmitted by the light guide is directed onto the subject from the front end face of the anterior end portion 2a.

[0058] Alternatively, instead of a structure that transmits illumination light from a light source device via a light guide, a structure can be adopted in which a light-emitting element is provided in the front end 2a, power is supplied from the endoscope processor to the light-emitting element, and the light-emitting element emits illumination light.

[0059] Figure 2 This is a perspective view showing an example of the flexible tube 5 of the first embodiment.

[0060] The endoscope 1 includes a flexible tube 5. The flexible tube 5 is disposed in, for example, the insertion portion 2 of the endoscope 1 (i.e., the portion including the bent portion 2b and the tubular portion 2c). However, it is not limited to this, and the flexible tube 5 may also be disposed in a universal cable 4. Furthermore, the flexible tube 5 is not limited to use in the endoscope 1, but can be widely used in medical devices. For example, the flexible tube 5 may also be used in catheters and other treatment devices, sheaths, etc.

[0061] The flexible tube 5 is a flexible tube extending along a central axis O from one end to the other. The flexible tube 5 has multiple convex surfaces 6 and concave surfaces 7 defined by the multiple convex surfaces 6 on its outer peripheral surface 5A. The concave surface 7 has a bottom surface, unlike a slit.

[0062] The flexible tube 5 is formed by feeding heated plastic or other materials from an extruder into a cylindrical mold, and using a vacuum mechanism located in the mold to make the material adhere tightly to the inner circumferential surface of the mold. The cylindrical mold is, for example, composed of a pair of molds divided into two parts by a plane passing through a central axis. The pair of molds are transported and used, for example, in a ring track configuration.

[0063] Therefore, the shapes of the convex surface 6 and concave surface 7 formed on the outer peripheral surface 5A of the flexible tube 5 are precisely defined according to the mold. On the other hand, the inner peripheral surface 5B of the flexible tube 5 (refer to...) Figure 4 The concave and convex shapes are roughly formed based on the material that is tightly attached in a manner that makes the wall thickness approximately fixed. That is, when viewed from the inner circumferential surface 5B of the flexible tube 5, the portion corresponding to the convex surface 6 becomes the concave surface, and the portion corresponding to the concave surface 7 becomes the convex surface.

[0064] Each of the multiple convex surfaces 6 is surrounded by a concave surface 7 and is isolated from the others. That is, the multiple convex surfaces 6 are formed discontinuously in the axial direction parallel to the central axis O and in the circumferential direction around the central axis O.

[0065] The plurality of convex surfaces 6 each have, for example, the same shape (and examples of multiple shapes will be described later), and are arranged periodically along the outer peripheral surface 5A of the flexible tube 5. When the outer peripheral surface 5A of the flexible tube 5 is unfolded into a plane, the plurality of convex surfaces 6 are each polygonal, and in this case, quadrilateral.

[0066] Specifically Figure 2 In the example shown, the multiple convex surfaces 6 are rhomboid convex surfaces 6a that are rhomboid in shape when the outer peripheral surface 5A of the flexible tube 5 is unfolded into a plane. Furthermore, in the following text, "rhomboid convex surface" will be simply referred to as "rhomboid" and the term "convex surface" will be omitted. Similarly, for other convex surfaces of different shapes described below, the term "convex surface" will also be omitted.

[0067] As is well known, rhombus 6a has four sides of equal length. Regarding rhombus 6a, except when it becomes a square, one of its diagonals is longer than the other.

[0068] The convex surface 6 and the concave surface 7 are formed, for example, symmetrical about a plane passing through the central axis O. This makes demolding easier when molding using a two-part mold.

[0069] in addition, Figure 3 This is a perspective view showing a modified example of the flexible tube 5 according to the first embodiment.

[0070] exist Figure 2 The diameter of the flexible tube 5 shown is... Figure 3 If the diameter of the flexible tube 5 shown is the same, for example, Figure 3 The rhombus 6a′ shown is Figure 2 The area of ​​the rhombus 6a shown is relatively small. Figure 2 The rhombus 6a shown has two circumferentially arranged shapes, while Figure 3 The rhombus 6a′ shown has, for example, four circumferentially arranged. The number of convex faces 6 arranged circumferentially is not limited to an even number; it can also be an odd number or any appropriate number.

[0071] Figure 4 This is a diagram showing the structure when the outer peripheral surface 5A of the flexible tube 5 of the first embodiment is unfolded into a plane. Additionally, in Figure 4 The diagram also shows the axial and circumferential cross-sections of the flexible tube 5 unfolded into a plane.

[0072] Figure 2 The example of rhombus 6a is, for example, along the long diagonal and the axial direction ( Figure 4 Tilting is performed periodically in a manner parallel to the direction of arrow A shown (where refers to tiling of planes other than concave surface 7, the same applies below).

[0073] Therefore, the concave surface 7 is entirely inclined relative to the axial direction and relative to the circumferential direction (in Figure 4 In the unfolded diagram, the direction perpendicular to arrow A is tilted.

[0074] Specifically, the concave surface 7 has a first inclined portion 7a1 that is inclined at an angle α relative to the axial direction and a second inclined portion 7a2 that is inclined at an angle -α relative to the axial direction. Here, α is an angle of 45° or less. The first inclined portion 7a1 and the second inclined portion 7b2 are respectively the spiral concave surfaces 7 in the flexible tube 5.

[0075] In addition, α is not limited to below 45°. Depending on the design requirements, α can also be set to an angle larger than 45°.

[0076] For example, if α is set to 45° or less, the torque resistance is slightly lower compared to the case where it is set to greater than 45°, but the expansion and contraction resistance is improved. Therefore, when it is important to suppress the expansion and contraction of the flexible tube 5 under compressive or tensile forces, it is advisable to set α to 45° or less.

[0077] Conversely, if α is greater than 45°, although the tensile strength is slightly lower compared to the case where it is less than 45°, the torque strength is improved. Therefore, when it is important to suppress the torsion of the flexible tube 5 under torsional force around the central axis O, it is advisable to make α greater than 45°.

[0078] In this way, by controlling the angle α, it is possible to control how the stretching tolerance and torque tolerance, which are in a trade-off relationship, are balanced.

[0079] In addition, such as Figure 4 As shown in the cross section, the concave surface 7 can also be filled with a filling material to form a filled structure portion 9.

[0080] That is, the flexible tube 5 can also have a tube body 8 and a filling structure part 9.

[0081] The tube body 8 is made of a material with a first Young's modulus and is formed by the above-mentioned mold to have multiple convex surfaces 6 and concave surfaces 7.

[0082] The filling structure 9 is formed by filling the concave surface 7 of the tube body 8 with a filling material of a second Young's modulus that is lower than the first Young's modulus.

[0083] At this point, the filling ratio of the filling material in the filling structure 9 can also be made different along the axial direction. Figure 4 In the example shown in the axial section, the filling ratio decreases sequentially for the base end side filling structure portion 9a, the middle filling structure portion 9b, and the front end side filling structure portion 9c.

[0084] In addition, such as Figure 4 As shown in the circumferential cross-section, the filling ratio of the circumferential filler material is fixed. However, in order to make the ease of bending different according to the bending direction, the filling ratio of the circumferential filler material can also be varied.

[0085] In addition, such as Figure 4 As shown, the radial distance from the concave surface 7 to the convex surface 6, centered on the central axis O (the depth of the concave surface 7 relative to the convex surface 6, or the height of the convex surface 6 relative to the concave surface 7), can also vary depending on the position of the concave surface 7 on the flexible tube 5. Figure 4 In the example, the depth of the concave surface 7 at the location where the filling structure portion 9c is located is greater than the depth of the concave surface 7 at the locations where the filling structure portions 9a and 9b are located. Alternatively, the depth from the convex surface 6 to the concave surface 7 can vary depending on the angle of the concave surface 7 relative to the axial direction.

[0086] In this way, by setting the filling structure 9 and adjusting the depth of the concave surface 7 according to the position on the flexible tube 5, the bending properties of the flexible tube 5 and its viscoelastic properties during bending can be controlled more freely.

[0087] According to the first embodiment, the flexible tube 5 is formed with a structure having a plurality of convex surfaces 6 that are surrounded by concave surfaces 7 and isolated from each other. As a result, the flexible tube 5 of this embodiment can achieve characteristics that cannot be achieved in a corrugated tube with a corrugated structure in which annular convex and annular concave portions are alternately formed along the direction of the central axis O.

[0088] Compared to a corrugated tube with a corrugated structure, the surface smoothness of the flexible tube 5 in this embodiment is slightly higher. In particular, when the concave surface 7 forms a filling structure portion 9, the surface smoothness can be further improved, making it a structure more suitable for medical devices such as endoscopes 1 that are inserted into the subject.

[0089] The flexible tube 5 of this embodiment has a concave surface 7 that is inclined relative to the axial direction and relative to the circumferential direction, thus improving the stretch resistance while maintaining the flexibility.

[0090] The flexible tube 5 of this embodiment allows for more flexible control over the balance of bending resistance, stretching resistance, and torque resistance. Specifically, various parameters such as the angle α of the concave surface 7 and the depth from the convex surface 6 can be adjusted, thus providing a high degree of freedom in controlling its properties.

[0091] By filling the concave surface 7 with a filler material whose Young's modulus is lower than that of the tube body 8, a filling structure portion 9 is provided. The filling ratio of the filling structure portion 9 is adjusted according to its position, thereby imparting different elastic deformation characteristics to the flexible tube 5 compared to the tube body 8. This allows for situations where it is desired to change the stiffness in the tubular portion 2c and the bent portion 2b, for example. Furthermore, more parameters are available for controlling the characteristics, increasing the degree of freedom in optimizing the characteristics of the flexible tube 5.

[0092] Similar to conventional corrugated pipes, the flexible pipe 5 of this embodiment can be manufactured at low cost using an extruder and a mold equipped with a vacuum mechanism.

[0093] [Second Implementation]

[0094] Figure 5 This diagram illustrates the structure when the outer peripheral surface 5A of the flexible tube 5 according to the second embodiment of the present invention is unfolded into a plane. In the second embodiment, the same reference numerals are used for the same parts as in the first embodiment, and descriptions are omitted as appropriate. In the second embodiment, the differences from the first embodiment will be mainly described.

[0095] like Figure 5 As shown, the multiple convex surfaces 6 each have the same shape, and when the outer peripheral surface 5A of the flexible tube 5 is unfolded into a plane, it forms a rectangle 6b. As is well known, the rectangle 6b has four right angles, and except when the rectangle 6b is a square, it has a pair of opposite long sides and a pair of opposite short sides.

[0096] Among the rectangles 6b that form multiple convex surfaces 6, there are two types: rectangle 6b1 with its long side arranged in the direction from the upper left to the lower right, and rectangle 6b2 with its long side arranged in the direction from the upper right to the lower left.

[0097] Additionally, the concave surface 7 has a first inclined portion 7b1 that is inclined relative to the axial direction along the long side of the rectangle 6b1. Figure 5 The portion enclosed by the dashed line) and the second inclined portion 7b2, which is inclined relative to the axis along the long side of rectangle 6b2. Figure 5 The part enclosed by a single-dot dash.

[0098] The two ends of the first inclined portion 7b1 abut against the rectangle 6b2. Similarly, the two ends of the second inclined portion 7b2 abut against the rectangle 6b1. Thus, the first inclined portion 7b1 and the second inclined portion 7b2 are formed intermittently, and their axial length is shorter than the axial length of the flexible tube 5. Furthermore, the circumferential angle of the intermittently formed first inclined portion 7b1 and second inclined portion 7b2 is less than 360°.

[0099] According to the second embodiment, it achieves roughly the same effect as the first embodiment.

[0100] Furthermore, in the first embodiment, the spiral-shaped first inclined portion 7a1 and second inclined portion 7a2 are continuous in the axial direction of the flexible tube 5. In contrast, in the second embodiment, the first inclined portion 7b1 and the second inclined portion 7b2 are formed intermittently in the axial direction. As a result, the flexible tube 5 of the second embodiment can further improve the degree of freedom in controlling characteristics such as bending resistance, stretching resistance, and torque resistance.

[0101] In addition, Figure 5 In this arrangement, rectangle 6b is positioned such that each side is inclined relative to the axial direction, but this is not a limitation. Alternatively, one pair of opposite sides of rectangle 6b may be positioned along the axial direction, and another pair of opposite sides may be positioned along the circumferential direction. Furthermore, it is not limited to making multiple rectangles 6b of the same size; the sizes of rectangles 6b may differ depending on their position, etc.

[0102] [Third Implementation Method]

[0103] Figure 6 and Figure 7 This represents the third embodiment of the present invention. Figure 6 This is a perspective view of the flexible tube 5 according to the third embodiment. Figure 7 This is a diagram showing the structure when the outer peripheral surface 5A of the flexible tube 5 of the third embodiment is unfolded into a plane.

[0104] In the third embodiment, the parts that are the same as in the first and second embodiments are labeled with the same reference numerals and descriptions are omitted as appropriate. The third embodiment mainly describes the differences from the first and second embodiments.

[0105] like Figure 6 and Figure 7 As shown, when the outer peripheral surface 5A of the flexible tube 5 is unfolded into a plane, the multiple convex surfaces 6 are respectively T-shaped 6c. The T-shaped 6c is a concave octagon (concave polygon) with two interior angles that are concave (angle greater than 180° and less than 360°) (specifically, an interior angle of 270°), and the other six interior angles are 90°.

[0106] The longest side of the T-shape 6c is arranged circumferentially. In this arrangement, all eight sides of the T-shape 6c are parallel to either the axial or circumferential direction. Thus, the concave surface 7 includes a first portion 7c1 along the axial direction (in... Figure 7 In the diagram, a first part 7c1 is represented by a dashed line enclosing a second part 7c2 along the circumference. Figure 7 In the middle, a second part 7c2 is represented by a single-dotted line enclosing it.

[0107] That is, the concave surface 7 includes at least one of a first portion 7c1 and a second portion 7c2. The first portion 7c1 is formed discontinuously in the axial direction. Therefore, the axial length of the first portion 7c1 is shorter than the axial length of the entire flexible tube 5. The second portion 7c2 is formed discontinuously in the circumferential direction. Therefore, the circumferential length of the second portion 7c2 is shorter than the circumferential length of the outer circumferential surface 5A of the flexible tube 5.

[0108] At this point, the depth of the first part 7c1 relative to the convex surface 6 can be different from the depth of the second part 7c2 relative to the convex surface 6. Additionally, the length of the first part 7c1 can be different from the length of the second part 7c2. Furthermore, the width of the first part 7c1 can be different from the width of the second part 7c2.

[0109] Among the multiple T-shaped 6cs, the axial spacing of two adjacent T-shaped 6cs in the circumferential direction is staggered by 1 / 2 spacing. That is, the multiple T-shaped 6cs have T-shaped 6c1 and T-shaped 6c2 whose axial spacing is staggered by 1 / 2 spacing.

[0110] According to the third embodiment, it achieves roughly the same effect as the first and second embodiments.

[0111] Furthermore, according to the third embodiment, a first portion 7c1 along the axial direction and a second portion 7c2 along the circumferential direction are provided. Therefore, by adjusting the depth, length, width, etc. of the first portion 7c1 and the second portion 7c2, the degree of freedom in controlling the properties can be improved.

[0112] [Fourth Implementation Method]

[0113] Figure 8 This diagram illustrates the structure when the outer peripheral surface 5A of the flexible tube 5 according to the fourth embodiment of the present invention is unfolded into a plane. In the fourth embodiment, the same reference numerals are used for the same parts as in the first to third embodiments, and descriptions are omitted as appropriate. In the fourth embodiment, the differences from the first to third embodiments will be mainly described.

[0114] like Figure 8As shown, when the outer peripheral surface 5A of the flexible tube 5 is unfolded into a plane, the multiple convex surfaces 6 are respectively L-shaped 6d. The L-shaped 6d is a concave hexagon (concave polygon) with one interior angle that is concave (specifically, an interior angle of 270°) and the other five interior angles being 90°.

[0115] The L-shaped 6d is configured such that one of its two long sides is along the axial direction and the other along the circumferential direction. In this configuration, the six sides of the L-shaped 6d are parallel to either the axial or circumferential direction. Thus, the concave surface 7 includes a first portion 7d1 along the axial direction (in... Figure 8 In the diagram, a first part 7d1 is represented by a dashed line enclosing a second part 7d2 along the circumference. Figure 8 In the middle, a second part 7d2 is represented by a single-dotted line enclosing it.

[0116] That is, the concave surface 7 includes at least one of a first portion 7d1 and a second portion 7d2. The first portion 7d1 is formed discontinuously in the axial direction. Therefore, the axial length of the first portion 7d1 is shorter than the axial length of the entire flexible tube 5. The second portion 7d2 is formed discontinuously in the circumferential direction. Therefore, the circumferential length of the second portion 7d2 is shorter than the circumferential length of the outer circumferential surface 5A of the flexible tube 5.

[0117] At this point, the depth of the first part 7d1 relative to the convex surface 6 can be different from the depth of the second part 7d2 relative to the convex surface 6. Additionally, the length of the first part 7d1 can be different from the length of the second part 7d2. Furthermore, the width of the first part 7d1 can be different from the width of the second part 7d2.

[0118] In addition, Figure 8 The diagram shows an L-shaped 6d with edges along the axial direction and edges along the circumference, but in this structure, there is no plane symmetry about the plane containing the central axis O. Therefore, it is also possible to configure the L-shaped 6d to become a V-shape, for example, by rotating it by 45°, thus producing plane symmetry about the plane containing the central axis O.

[0119] According to the fourth embodiment, it achieves roughly the same effect as the first to third embodiments.

[0120] Furthermore, according to the fourth embodiment, a first portion 7d1 along the axial direction and a second portion 7d2 along the circumferential direction are provided. Therefore, by adjusting the depth, length, width, etc. of the first portion 7d1 and the second portion 7d2, the degree of freedom for controlling the properties can be improved.

[0121] [Fifth Implementation]

[0122] Figure 9This diagram illustrates the structure when the outer peripheral surface 5A of the flexible tube 5 according to the fifth embodiment of the present invention is unfolded into a plane. In the fifth embodiment, the same reference numerals are used for the same parts as in the first to fourth embodiments, and descriptions are omitted as appropriate. In the fifth embodiment, the differences from the first to fourth embodiments will be mainly described.

[0123] like Figure 9 As shown, when the outer peripheral surface 5A of the flexible tube 5 is unfolded into a plane, the multiple convex surfaces 6 each take the form of rounded polygons. A rounded polygon is roughly a polygon whose corners are rounded. In this case, the sides of the polygon are not limited to straight lines; for example, they can also be concave arcs pointing towards the center of the rounded polygon.

[0124] Figure 9 The example shown is specifically a rounded triangle 6e (e.g., a rounded equilateral triangle) with three concave arcs on its sides. The rounded triangle 6e is configured such that the first of its three sides is circumferential. In this configuration, the second of the three sides of the rounded triangle 6e forms an angle β with the axis, and the third side forms an angle -β with the axis. In the case of the rounded triangle 6e, for example, a rounded equilateral triangle, β = 30° (i.e., less than 45°).

[0125] The concave surface 7 includes a first portion 7e1 along the first side (in) Figure 9 In the middle, a first part 7e1 is represented by a dashed line surrounding it, and the second part 7e2 is represented along the second side (in... Figure 9 In the middle, a second part 7e2 is represented by a single-dotted line enclosing it, and the third part 7e3 along the third side (in... Figure 9 In the middle, a third part 7e3 is represented by a double-dotted line enclosing it.

[0126] The first portion 7e1 is formed discontinuously in the circumferential direction. Therefore, the circumferential length of the first portion 7e1 is shorter than the circumferential length of the outer circumferential surface 5A of the flexible tube 5. The second portion 7e2 and the third portion 7e3 are formed discontinuously in both the axial and circumferential directions. Therefore, the axial lengths of the second portion 7e2 and the third portion 7e3 are shorter than the axial length of the flexible tube 5 as a whole. In addition, the circumferential angle range of the second portion 7e2 and the third portion 7e3 is less than 360°.

[0127] In this case, the depths of the first part 7e1, the second part 7e2, and the third part 7e3 relative to the convex surface 6 can also be different. Furthermore, the lengths of the first part 7e1, the second part 7e2, and the third part 7e3 can also be different. And the widths of the first part 7e1, the second part 7e2, and the third part 7e3 can also be different.

[0128] According to the fifth embodiment, it achieves roughly the same effect as the first to fourth embodiments.

[0129] Furthermore, according to the fifth embodiment, a first portion 7e1, a second portion 7e2, and a third portion 7e3 with different orientations are provided. Therefore, by adjusting the depth, length, width, etc. of the first portion 7e1, the second portion 7e2, and the third portion 7e3, the degree of freedom in controlling the properties can be improved.

[0130] [Sixth Implementation Method]

[0131] Figure 10 This diagram illustrates the structure when the outer peripheral surface 5A of the flexible tube 5 according to the sixth embodiment of the present invention is unfolded into a plane. In the sixth embodiment, the same reference numerals are used for the same parts as in the first to fifth embodiments, and descriptions are omitted as appropriate. In the sixth embodiment, the differences from the first to fifth embodiments will be mainly described.

[0132] like Figure 10 As shown, when the outer peripheral surface 5A of the flexible tube 5 is unfolded into a plane, the multiple convex surfaces 6 are polygons. Figure 10 The example shown is specifically a triangle 6f (e.g., an equilateral triangle).

[0133] That is, in this embodiment, the flexible tube 5 is configured to use a triangle 6f instead of a triangle. Figure 9 The rounded triangle 6e of the fifth embodiment shown.

[0134] Triangle 6f, for example, has a first side along the circumference and a second and third side intersecting the axis (and the circumference). In the case where triangle 6f is, for example, an equilateral triangle, the second and third sides intersect the axis at 30° and -30°, respectively.

[0135] The concave surface 7 includes a first portion 7f1 along the first side (in) Figure 10 In the middle, a first part 7f1 is represented by a dashed line surrounding it, and the second part 7f2 is represented along the second side (in... Figure 10 In the diagram, a second part 7f2 is represented by a dashed line enclosing a single dot), and a third part 7f3 is represented along the third side (in...). Figure 10 In the middle, a third part 7f3 is represented by a double-dotted line enclosing it.

[0136] The first portion 7f1 is formed discontinuously in the circumferential direction. Therefore, the circumferential length of the first portion 7f1 is shorter than the circumferential length of the outer circumferential surface 5A of the flexible tube 5. The second portion 7f2 and the third portion 7f3 are formed discontinuously in both the axial and circumferential directions. Therefore, the axial length of the second portion 7f2 and the third portion 7f3 is shorter than the axial length of the flexible tube 5 as a whole. In addition, the circumferential angle range of the second portion 7f2 and the third portion 7f3 is less than 360°.

[0137] In this case, the depths of the first part 7f1, the second part 7f2, and the third part 7f3 relative to the convex surface 6 can also be different. Furthermore, the lengths of the first part 7f1, the second part 7f2, and the third part 7f3 can also be different. Additionally, the widths of the first part 7f1, the second part 7f2, and the third part 7f3 can also be different.

[0138] According to the sixth embodiment, it achieves roughly the same effect as the first to fifth embodiments.

[0139] Furthermore, according to the sixth embodiment, a first portion 7f1, a second portion 7f2, and a third portion 7f3 with different orientations are provided. Therefore, by adjusting the depth, length, width, etc. of the first portion 7f1, the second portion 7f2, and the third portion 7f3, the degree of freedom in controlling the properties can be improved.

[0140] [Seventh Implementation Method]

[0141] Figure 11 This diagram illustrates the structure when the outer peripheral surface 5A of the flexible tube 5 according to the seventh embodiment of the present invention is unfolded into a plane. In the seventh embodiment, the same reference numerals are used for the same parts as in the first to sixth embodiments, and descriptions are omitted as appropriate. In the seventh embodiment, the differences from the first to sixth embodiments will be mainly described.

[0142] like Figure 11 As shown, when the outer peripheral surface 5A of the flexible tube 5 is unfolded into a plane, the multiple convex surfaces 6 are polygonal. Figure 10 The example shown is specifically a hexagon 6g (e.g., a regular hexagon).

[0143] Figure 11 The hexagon 6g shown is filled with a plane such that the first pair of its three opposing sides is parallel to the axis. In the case where the hexagon 6g is, for example, a regular hexagon, the second and third pairs of sides intersect the axis at 60° and -60°, respectively.

[0144] Concave surfaces 7 are positioned between hexagons 6g. In this case, the depth, width, etc., of the concave surfaces 7 along the first pair of sides, the second pair of sides, and the third pair of sides relative to the convex surface 6 can be different. Alternatively, by using hexagons 6g other than regular hexagons, the lengths of the individual concave surfaces 7 can also be different.

[0145] According to the seventh embodiment, it achieves roughly the same effect as the first to sixth embodiments.

[0146] Furthermore, according to the seventh embodiment, by adjusting the depth, length, width, etc. of the concave surface 7 according to the position where the concave surface 7 is provided, the degree of freedom in controlling the properties can be improved.

[0147] [Eighth Implementation Method]

[0148] Figure 12 This diagram illustrates the structure when the outer peripheral surface 5A of the flexible tube 5 according to the eighth embodiment of the present invention is unfolded into a plane. In the eighth embodiment, the same reference numerals are used for the same parts as in the first to seventh embodiments, and descriptions are omitted as appropriate. In the eighth embodiment, the differences from the first to seventh embodiments will be mainly described.

[0149] In the first to seventh embodiments, the plurality of convex surfaces 6 each have the same shape. In contrast, in this embodiment, the convex surfaces 6 are configured to combine two different shapes, and planar filling is performed based on the convex surfaces 6.

[0150] When the outer peripheral surface 5A of the flexible tube 5 is unfolded into a plane, the multiple convex surfaces 6 have, for example, two types of polygons 6h: quadrilateral 6h1 (e.g., square) and octagon 6h2 (e.g., regular octagon).

[0151] When quadrilateral 6h1 is a square and octagon 6h2 is a regular octagon, quadrilateral 6h1 has four sides of equal length, and octagon 6h2 has eight sides of equal length. The length of one side of quadrilateral 6h1 is equal to the length of one side of octagon 6h2.

[0152] exist Figure 12 In the example shown, multiple convex surfaces 6 are arranged such that the first pair of sides of the quadrilateral 6h1 is axial and the second pair of sides is circumferential.

[0153] The concave surface 7 has a first portion 7h1 disposed between the quadrilateral 6h1 and the octagon 6h2 and a second portion 7h2 disposed between adjacent octagons 6h2.

[0154] The depth, length, and width of the first part 7h1 and the second part 7h2 can also vary depending on their position and direction (axial, circumferential, oblique, etc.) on the flexible tube 5.

[0155] According to the eighth embodiment, it achieves roughly the same effect as the first to seventh embodiments.

[0156] Furthermore, according to the eighth embodiment, by adjusting the depth, length, width, etc. of the concave surface 7 according to the position and direction of the concave surface 7, the degree of freedom in controlling the properties can be improved.

[0157] In addition, Figure 12 The diagram shows an example of multiple convex surfaces 6 having both quadrilateral 6h1 and octagonal 6h2 shapes, but other types of shapes can also be combined. Furthermore, the multiple convex surfaces 6 are not limited to two shapes, but can also have three or more shapes.

[0158] [Ninth Implementation Method]

[0159] Figure 13 This diagram illustrates the structure when the outer peripheral surface 5A of the flexible tube 5 according to the ninth embodiment of the present invention is unfolded into a plane. In the ninth embodiment, the same reference numerals are used for the same parts as in the first to eighth embodiments, and descriptions are omitted as appropriate. In the ninth embodiment, the differences from the first to eighth embodiments will be mainly described.

[0160] In the first to seventh embodiments, convex surfaces 6 of one shape are arranged periodically, while in the eighth embodiment, convex surfaces 6 of two shapes are arranged periodically. In contrast, in this embodiment, convex surfaces of one shape are arranged non-periodically, and planar filling based on the convex surfaces 6 is performed.

[0161] Multiple convex surfaces 6 are arranged non-periodically along the outer peripheral surface 5A. Figure 13 The convex surface 6 shown is a concave thirteen-sided polygon (concave polygon) 6i with four concave interior angles. Furthermore, in Figure 13 In order to easily distinguish the multiple concave thirteen-sided polygons 6i, shading lines are used to differentiate them, but the multiple concave thirteen-sided polygons 6i have the same shape.

[0162] Specifically, the concave 13-sided polygon 6i is also known as "Smith's Hat," as documented on the following website, for example.

[0163] A chiral aperiodic monotile [David Smith1, Joseph Samuel Myers2,Craig S. Kaplan3, and Chaim Goodman-Strauss4] arXiv:2305.17743v1 [math.CO] 28May 2023 [retrieved on 2023-09-07] Retrieved from the Internet: (URL: https: / / arxiv.org / pdf / 2305.17743.pdf)

[0164] In addition, the concave surface 7 is positioned between adjacent concave thiagons 6i.

[0165] also, Figure 13 The concave thiagon 6i shown can be configured non-periodically, but examples of non-periodic configurations of the same shape using both sides are also known, for example, as described on the following website. Such a structure combining the front and back sides can also be applied to the flexible tube 5.

[0166] An aperiodic monotile [David Smith1, Joseph Samuel Myers 2, Craig S. Kaplan3, and Chaim Goodman-Strauss4] arXiv:2303.10798v2 [math.CO] 29 May 2023 [retrieved on 2023-09-07] Retrieved from the Internet: (URL: https: / / arxiv.org / pdf / 2303.10798.pdf)

[0167] Furthermore, examples of combining two shapes known as Penrose paving rather than periodically arranging patterns are also known, and such structures combining multiple shapes can be applied to flexible tubes 5.

[0168] According to the ninth embodiment, it achieves roughly the same effect as the first to eighth embodiments.

[0169] Furthermore, according to the ninth embodiment, it is possible to obtain characteristics that are generally uniform from a global perspective but non-uniform from a local perspective.

[0170] [Tenth Implementation Method]

[0171] Figure 14This diagram illustrates the structure when the outer peripheral surface 5A of the flexible tube 5 according to the tenth embodiment of the present invention is unfolded into a plane. In the tenth embodiment, the same reference numerals are used for the same parts as in the first to ninth embodiments, and descriptions are omitted as appropriate. In the tenth embodiment, the differences from the first to ninth embodiments will be mainly described.

[0172] In the first to ninth embodiments, the two-dimensional shape of the convex surface 6 (and consequently the concave surface 7) is, in principle, fixed regardless of its axial position. In contrast, this embodiment causes the two-dimensional shape of the convex surface 6 (and consequently the concave surface 7) to vary along the axial direction.

[0173] like Figure 14 As shown, the flexible tube 5 is provided with a first region AR1, a second region AR2 and a third region AR3 along the axial direction.

[0174] In addition, Figure 14 The document also includes curves showing the surface shape when the outer peripheral surface 5A of the flexible tube 5, which is unfolded into a plane, is cut with four single-dot dashed lines (axial single-dot dashed line, circumferential single-dot dashed line in the first region AR1, circumferential single-dot dashed line in the second region AR2, and circumferential single-dot dashed line in the third region AR3).

[0175] The first region AR1 is, for example, a region with relatively low flexibility (i.e., stiffness). Specifically, the plurality of convex surfaces 6 arranged in the first region AR1 form rhombuses 6j when the outer peripheral surface 5A of the flexible tube 5 is unfolded into a plane. Concave surfaces 7j are provided between adjacent rhombuses 6j.

[0176] The second region AR2 is, for example, a region with relatively moderate flexibility (i.e., medium stiffness). Specifically, the plurality of convex surfaces 6 arranged in the second region AR2 form rhombuses 6k when the outer peripheral surface 5A of the flexible tube 5 is unfolded into a plane. The area of ​​a rhombus 6k is, for example, smaller than the area of ​​a rhombus 6j.

[0177] A concave surface 7k is provided between adjacent rhombuses 6k. The concave surface 7k has a peak 7k1 at its center. The height of the peak 7k1 is lower than the height of the rhombuses 6k. That is, when viewed from the rhombuses 6k, which are convex surfaces 6, the peak 7k1 is also part of the concave surface 7k. By providing the peak 7k1, the concave surface 7k is easier to bend, and its elasticity in the direction perpendicular to the peak 7k1 is increased.

[0178] Furthermore, regarding the ratio of the area of ​​the convex surface 6 to the area of ​​the concave surface 7 in each region, for example, the first region AR1 is larger than the second region AR2.

[0179] The third region AR3 is, for example, a region with relatively high flexibility (i.e., softness). A comparison of the flexibility of each region AR1 to AR3 is as follows. In both the axial and circumferential directions, regarding the number of bumps and dents per unit length, the second region AR2 has more than the first region AR1, and the third region AR3 has more than the second region AR2. Therefore, regarding flexibility, the second region AR2 is higher than the first region AR1, and the third region AR3 is higher than the second region AR2.

[0180] When the outer peripheral surface 5A of the flexible tube 5 is unfolded into a plane, the multiple convex surfaces 6 arranged in the third region AR3 have a first convex surface 6l and an inner rhombus 6m.

[0181] The first convex surface 6l is a convex surface formed by connecting multiple annular rhombuses (hereinafter referred to as outer rhombuses) in the circumferential direction. The connection of the multiple outer rhombuses in the circumferential direction can be understood by observing a graph showing the surface shape when the outer circumferential surface 5A is cut by a single-dotted line in the third region AR3. However, it is also possible to leave the multiple outer rhombuses isolated without connecting them in the circumferential direction.

[0182] The inner rhombus 6m is a convex surface that is arranged separately from the outer rhombuses on the inner side of the first convex surface 6l, without being connected to them. In this way, other convex surfaces 6 can also be provided on the inner side of a certain convex surface 6.

[0183] A concave surface 7l is provided between each other on the first convex surface 6l that is adjacent in the axial direction. In addition, a concave surface 7m is provided between the outer rhombus and the inner rhombus 6m of the first convex surface 6l. In this way, the first convex surface 6l and the inner rhombus 6m are each surrounded by the concave surface 7 (concave surface 7l or concave surface 7m), and are isolated from the other convex surfaces 6.

[0184] Thus, within a first range along the axial direction (e.g., any one of the first region AR1, the second region AR2, and the third region AR3), the plurality of convex surfaces 6 each have a first shape. Furthermore, within a second range along the axial direction that is different from the first range (e.g., any other one of the first region AR1, the second region AR2, and the third region AR3), the plurality of convex surfaces 6 each have a second shape different from the first shape.

[0185] In addition, in the above, the shape patterns of the convex surface 6 and the concave surface 7 are switched according to each region, but it is not limited to this. For example, it can also be configured to use morphing to make the shape patterns of the convex surface 6 and the concave surface 7 change smoothly along the axis.

[0186] According to the tenth embodiment, it achieves roughly the same effect as the first to ninth embodiments.

[0187] Furthermore, according to the tenth embodiment, the shape patterns of the convex surface 6 and the concave surface 7 are varied axially. Therefore, depending on how the shape patterns are varied, characteristics such as axial bending resistance, tensile strength, and torque resistance can be controlled with greater degrees of freedom in the axial direction. Thus, a flexible tube 5 can, for example, be configured to have a region suitable for the tubular portion 2c and a region suitable for the bent portion 2b.

[0188] [Eleventh Implementation Method]

[0189] Figure 15 This is a perspective view showing the flexible tube 5 according to the eleventh embodiment of the present invention. In this eleventh embodiment, the same reference numerals are used for the same parts as in the first to tenth embodiments, and descriptions are omitted as appropriate. In this eleventh embodiment, the differences from the first to tenth embodiments will be mainly described.

[0190] The flexible tubes 5 of the first to tenth embodiments each have a plurality of convex surfaces 6, each surrounded by a concave surface 7 and isolated from each other. In contrast, the flexible tube 5 of this embodiment is formed by connecting a plurality of convex surfaces 6 that are annular in the circumferential direction in the axial direction.

[0191] The flexible tube 5 can be applied to the insertion part 2, which includes the bending part 2b and the tubular part 2c. Here, for example, if a corrugated tube with a corrugated structure is used for the tubular part 2c, it can help improve the operation technique (good flexibility, reduced operator fatigue) because it is lightweight and has good flexibility.

[0192] However, the bellows expands and contracts axially. Therefore, if the bellows is used in the insertion part 2, for example, during a push / pull operation in the lower endoscope technique, the operator's insertion sensation will differ from the actual insertion length, reducing the operability of the technique. Therefore, referring to... Figure 15 The structure of the flexible tube 5, which has improved extensibility resistance compared to a corrugated tube, is described.

[0193] Figure 15 The flexible tube 5 shown has a plurality of convex surfaces 6p arranged in a ring shape in the circumferential direction. Concave surfaces 7 are respectively arranged between adjacent convex surfaces 6p. In addition, the concave surfaces 7 can also be filled with a filling material to form a filling structure portion 9, as described above.

[0194] Two adjacent convex surfaces 6p are connected by a connecting convex surface. The two adjacent convex surfaces 6p are relatively difficult to stretch or contract in the part where the connecting convex surface is provided, and are relatively easy to stretch or contract in the part where the connecting convex surface is not provided.

[0195] For example, two adjacent convex surfaces 6p are connected by multiple connecting convex surfaces 6q that are inclined relative to the axis (i.e., not parallel to the axis). For example, two connecting convex surfaces 6q are inclined at an angle symmetrical about the axis.

[0196] exist Figure 15 In the first example shown, multiple connecting convex surfaces 6q are arranged circumferentially in an isolated manner. The connecting convex surfaces 6q are connected to the two convex surfaces 6p at fixed angles.

[0197] In addition, Figure 15 When only two connecting convex surfaces 6q are configured in the position shown, the two connecting convex surfaces 6q are not positioned 180° apart in the circumferential direction. By configuring the connecting convex surfaces 6q at unequal offset positions around the central axis O, it is possible to control the direction that is easy to bend and the direction that is difficult to bend.

[0198] In addition, Figure 15 In the second example shown, two adjacent convex surfaces 6p are connected, for example, using an X-shaped connecting convex surface 6x. The connecting convex surface 6x is formed by multiple (two in the illustrated example) convex surfaces 6 intersecting. Furthermore, the position where the multiple convex surfaces 6 intersect is not limited to the center position of the connecting convex surface 6x (the central position along the axial direction of the connecting convex surface 6x). In this case, the connecting convex surface 6x is also connected with a fixed angle relative to each of the two convex surfaces 6p.

[0199] Furthermore, in Figure 15 In the third example shown, two adjacent convex surfaces 6p are connected, for example, using a Y-shaped connecting convex surface 6y. The connecting convex surface 6y is a structure in which multiple convex surfaces 6 converge midway to form a single convex surface. Furthermore, the convergence point of the multiple convex surfaces 6 is not limited to the center of the connecting convex surface 6y. In this case, portions of the two branches of the connecting convex surface 6y are connected at a fixed angle relative to one convex surface 6p. Additionally, the converging portion of the connecting convex surface 6y is connected, for example, perpendicularly to another convex surface 6p.

[0200] In addition, Figure 15 The example shown is of setting up three types of convex surfaces 6q, 6x, and 6y, but of course, you can also set up any one or two.

[0201] According to the tenth embodiment, since the connecting convex surfaces 6q, 6x, and 6y are provided, the characteristic of the bellows to suppress axial expansion and contraction can be suppressed, and a flexible tube 5 suitable for the bending portion 2b and the tubular portion 2c that require expansion and contraction resistance can be formed.

[0202] Furthermore, by connecting the portions of the convex surfaces 6q, 6x, and 6y that are inclined relative to the axial direction, the stretching resistance and torque resistance when a rotational torque about the central axis O is applied to the flexible tube 5 can be obtained. At this time, by adjusting the tilt angle, the balance between the stretching resistance and torque resistance of the flexible tube 5 can be adjusted.

[0203] Furthermore, by adjusting the circumferential positions of the connecting convex surfaces 6q, 6x, and 6y, the direction in which the flexible tube 5 is easy to bend and the direction in which it is difficult to bend can be controlled. On the other hand, by equally distributing the circumferential positions of the connecting convex surfaces, the direction in which the flexible tube 5 is easy to bend can be made uniform.

[0204] Furthermore, by making the circumferential positions of the connecting convex surfaces 6q, 6x, and 6y, which are in different axial positions, the ease of expansion and contraction can be made equal.

[0205] Furthermore, the X-shaped connecting convex surface 6x and the Y-shaped connecting convex surface 6y have branched portions, so when stress is applied to the flexible tube 5, the stress is distributed. Therefore, the stress acting on the flexible tube 5 is mitigated, and the expansion and contraction of the flexible tube 5 can be suppressed.

[0206] [Twelfth Implementation Method]

[0207] Figure 16 This is a perspective view showing the flexible tube 5 according to the twelfth embodiment of the present invention. In the twelfth embodiment, the same reference numerals are used for the same parts as in the first to eleventh embodiments, and descriptions are omitted as appropriate. In the twelfth embodiment, the differences from the first to eleventh embodiments will be mainly described.

[0208] In this embodiment, the flexible tube 5 has a plurality of convex surfaces 6 arranged in a ring shape in the circumferential direction, which are alternately tilted at different angles relative to the circumferential direction and connected at close points.

[0209] The flexible tube 5 has an annular first convex surface 6p1 inclined at a first angle relative to the circumference and an annular second convex surface 6p2 inclined at a second angle relative to the circumference. The first convex surface 6p1 and the second convex surface 6p2 are connected by a connecting portion 6r. The connecting portion 6r is a convex surface where the first convex surface 6p1 and the second convex surface 6p2 intersect.

[0210] That is, when focusing on a certain first convex surface 6p1, the first convex surface 6p1 is connected to a second convex surface 6p2 on one side of the axial direction via a first connecting portion 6r, and is connected to a second convex surface 6p2 on the other side of the axial direction via a second connecting portion 6r. The first connecting portion 6r and the second connecting portion 6r are, for example, located on opposite sides in the circumferential direction, that is, at a position 180° apart in the circumferential direction.

[0211] For example, if the circumferential angle of the part with the first connecting part 6r is set to 0° and the circumferential angle of the part with the second connecting part 6r is set to 180°, then there is no connecting part 6r between 0° and 180° and between 180° and 0°.

[0212] Furthermore, an example is shown here where the connecting part 6r is set at a position 180° apart in the circumferential direction. However, by adjusting the circumferential angle of the connecting part 6r, it is possible to control the direction that is easy to bend and the direction that is difficult to bend.

[0213] Thus, the first convex surface 6p1 is connected to each of the two axially adjacent second convex surfaces 6p2 at one location, for a total of two locations. Furthermore, the second convex surface 6p2 is connected to each of the two axially adjacent first convex surfaces 6p1 at one location, for a total of two locations.

[0214] Between the first convex surface 6p1 and the second convex surface 6p2, a concave surface 7 is provided, excluding the connecting portion 6r. Alternatively, a filling structure portion 9 can be provided by filling the concave surface 7 with a filling material, as described above.

[0215] According to the twelfth embodiment, it achieves approximately the same effect as the eleventh embodiment described above. Furthermore, by adjusting the tilt angles of the first convex surface 6p1 and the second convex surface 6p2, the balance between the stretching resistance and torque resistance of the flexible tube 5 can be adjusted.

[0216] [Thirteenth Implementation Method]

[0217] Figure 17 This is a perspective view showing the flexible tube 5 according to the thirteenth embodiment of the present invention. In this thirteenth embodiment, the same reference numerals are used for the same parts as in the first to twelfth embodiments, and descriptions are omitted as appropriate. In this thirteenth embodiment, the differences from the first to twelfth embodiments will be mainly described.

[0218] In this embodiment, the flexible tube 5 has two convex surfaces 6 that are annular in the circumferential direction connected at multiple points in the circumferential direction.

[0219] The flexible tube 5 has multiple convex surfaces 6p that are annular in the circumferential direction.

[0220] In the case of a certain convex surface 6p, the convex surface 6p is connected to a convex surface 6p on one side of the axial direction through a first connecting part 6s, and is connected to a convex surface 6p on the other side of the axial direction through a second connecting part 6t. Both the first connecting part 6s and the second connecting part 6t are convex surfaces 6.

[0221] The first connecting part 6s is provided at two locations 180° apart in the circumferential direction, for example. The second connecting part 6t is provided at two locations 180° apart in the circumferential direction, for example. The angles of the first connecting part 6s and the second connecting part 6t around the central axis O differ by, for example, 90°.

[0222] Thus, a certain convex surface 6p is connected to a convex surface 6p on one side of the axial direction through two first connecting portions 6s, and is connected to a convex surface 6p on the other side of the axial direction through two second connecting portions 6t. Furthermore, the first connecting portions 6s and the second connecting portions 6t can be arranged at an angle relative to the axial direction or parallel to the axial direction.

[0223] Here, it is also possible that a certain convex surface 6p has a wavy inclination along the circumferential direction in such a way that the convex surface 6p is close to one side at two first connecting portions 6s and the convex surface 6p is close to the other side at two second connecting portions 6t.

[0224] Between the multiple convex surfaces 6p, in addition to the connecting portions 6s and 6t, there are concave surfaces 7. Alternatively, the concave surfaces 7 can be filled with a filling material to form a filling structure portion 9, which is the same as described above.

[0225] According to the thirteenth embodiment, it achieves roughly the same effect as the twelfth embodiment described above.

[0226] Furthermore, in the twelfth embodiment Figure 16 The image shows an example where a convex surface 6p is connected to other convex surfaces 6p at two locations, one above and one below (a total of two locations). Furthermore, in the thirteenth embodiment… Figure 17 The example shown illustrates a convex surface 6p connected to other convex surfaces 6p at two points above and two points below (a total of four points). However, this is not a limitation; structures where a convex surface 6p is connected to other convex surfaces 6p at three or more points are also possible.

[0227] [Related Technologies]

[0228] Figures 18 to 26 This section describes the related technologies of endoscope 1. In these related technologies, parts identical to those in the embodiments described above are labeled with the same reference numerals, and descriptions are omitted where appropriate. The main focus of this section is on the differences from the embodiments described above.

[0229] In the endoscope 1, for example, at the instrument insertion port 3d, a tube forming an instrument channel inserted inside is connected to an interface (cylinder) located at the instrument insertion port 3d. Such a tube connection requires strength, watertightness, pressure resistance, and other resistance properties. Achieving all these resistance standards would complicate the construction or increase costs.

[0230] For example, to ensure durability, sometimes it is necessary to use bends in the pipes and interfaces, which can complicate the construction.

[0231] When tapered pipes are used for pipe connections, the number of parts increases due to the use of nuts for fastening, leading to longer assembly times and more difficult fastening operations. Furthermore, torque management and anti-loosening measures for the nuts are required when tightening them.

[0232] Furthermore, when fixing pipes and interfaces using adhesives, it is difficult to apply the adhesive along the entire circumference of the pipe, sometimes resulting in coating deviations. Without coating deviations, durability is high, but with deviations, durability decreases. Therefore, durability depends on the workmanship and can become a cause of quality variations. Additionally, the use of adhesives requires a curing time, increasing manufacturing time. Furthermore, the bonded portion may deteriorate after bonding.

[0233] On the other hand, disposable endoscopes require simplified construction to reduce costs. Therefore, the desired outcomes are: fewer parts, faster amortization of manufacturing equipment, and high yield. (Refer to...) Figures 18 to 26 Explain the structure corresponding to such requirements.

[0234] Figure 18 This is a cross-sectional view showing the first connection structure between the tube 31 and the rigid component 32 in the related art. Furthermore, the following description will take the case where the rigid component 32 is an interface provided at the insertion port 3d of the treatment device as an example. In this case, in Figures 18 to 26 In the figure, the rigid component 32 side (left side of the figure) becomes the base side (base direction P side) of the endoscope 1, and the tube 31 side (right side of the figure) becomes the front end side (front end direction D side) of the endoscope 1.

[0235] The tube 31 is used, for example, as a channel within the endoscope 1 (treatment instrument channel, air / water supply channel, suction channel, etc.). The rigid component 32 is used, for example, as an interface for the channel opening of the endoscope 1. However, it is not limited to these uses; the tube 31 and the rigid component 32 can also be used in other parts within the endoscope 1 or in medical devices other than the endoscope.

[0236] The tube 31 is formed of resin, for example. The rigid component 32 is formed of a material harder than the tube 31.

[0237] The rigid component 32 has a through hole 32h. The through hole 32h of the rigid component 32 forms part of the aforementioned channel or path 30. The central axis 30x is the axis of the center of the path 30.

[0238] Regarding pipe 31, the base end of pipe 31 is disposed within the through hole 32h. The interior of pipe 31 constitutes another part of pipe 30.

[0239] A receiving surface 32a is formed within the through hole 32h of the rigid component 32 to receive the tube 31 inserted into the rigid component 32. An enlarged diameter portion 32b is provided at the opening at the front end of the through hole 32h. An O-ring 33 (first O-ring) is disposed in the enlarged diameter portion 32b and sleeved on the tube 31. The O-ring 33 contacts the outer peripheral surface 31c of the rigid component 32 and the tube 31.

[0240] A heat-shrinkable tube 34 is disposed on the outer periphery of the tube 31, the rigid component 32, and the O-ring 33. The heat-shrinkable tube 34 contacts the rigid component 32 and the tube 31, and shrinks while covering the rigid component 32 and the tube 31.

[0241] The operation of connecting the tube 31 to the rigid component 32 is performed, for example, by the following steps (1) to (5).

[0242] (1) Assemble an O-ring 33 on the outer circumferential surface 31c of the tube 31.

[0243] (2) Insert the heat shrink tube 34 into the tube 31.

[0244] (3) Insert the base end of the tube 31 into the receiving surface 32a of the rigid component 32.

[0245] (4) Place the O-ring 33 against the expanded diameter portion 32b of the rigid component 32.

[0246] (5) With the heat shrink tube 34 covering the rigid component 32, the O-ring 33 and the base end of the tube 31, the heat shrink tube 34 is heated to shrink the heat shrink tube 34.

[0247] Furthermore, if a heat shrink tube 34 with adhesive pre-applied to its inner circumferential surface is used, then the application of adhesive is not required, and the heat shrink tube 34 can be bonded to an object that abuts against the inner circumferential surface of the heat shrink tube 34.

[0248] According to the first connection structure, the adhesive properties of the heat-shrinkable tube 34 ensure the connection strength between the tube 31 and the rigid component 32. Furthermore, by shrinking the heat-shrinkable tube 34, the O-ring 33 is compressed radially inward, sealing the gap and ensuring watertightness. Moreover, since the heat-shrinkable tube 34 itself also maintains watertightness, combining the heat-shrinkable tube 34 with the O-ring 33 ensures an even stronger watertightness.

[0249] Figure 19 This is a cross-sectional view showing a second connection structure between the tube 31 and the rigid component 32 in the related art. In the second connection structure, the same reference numerals are used for the parts that are the same as in the first connection structure, and descriptions are omitted where appropriate. The main differences between the second connection structure and the first connection structure are explained in the second connection structure.

[0250] A receiving surface 32a of a receiving tube 31 is formed on the rigid component 32. A first O-ring 33a and a second O-ring 33b are assembled on the outer peripheral surface 31c of the tube 31. Therefore, the first O-ring 33a and the second O-ring 33b contact the outer peripheral surface 31c of the tube 31.

[0251] Insert the base end of the tube 31 into the receiving surface 32a of the rigid component 32, and abut the first O-ring 33a against the front end surface 32c of the rigid component 32. The second O-ring 33b is positioned slightly away from the first O-ring 33a, closer to the front end side.

[0252] The heat shrink tube 34 is formed to cover the rigid component 32, the first O-ring 33a, the second O-ring 33b and the base end of the tube 31, and the heat shrink tube 34 is heated to shrink the heat shrink tube 34.

[0253] The heat shrink tube 34 contacts the second O-ring 33b and shrinks while covering the second O-ring 33b, compressing the second O-ring 33b in the direction toward the central axis 30x of the pipe 30.

[0254] The second connection structure achieves the same effect as the first connection structure.

[0255] Furthermore, according to the second connection structure, the use of multiple O-rings ensures higher water tightness and higher connection strength.

[0256] Figure 20 This is a cross-sectional view showing the third connection structure between the pipe 31 and the rigid component 32 in the related art. In the third connection structure, the same reference numerals are used for the parts that are the same as in the first and second connection structures, and the descriptions are omitted as appropriate. The differences between the third connection structure and the first and second connection structures are mainly explained in the third connection structure.

[0257] A receiving surface 32a of a receiving tube 31 is formed on the rigid component 32. A first O-ring 33a and a second O-ring 33b are assembled on the outer peripheral surface 31c of the tube 31. At this time, the second O-ring 33b is positioned separately from the first O-ring 33a.

[0258] Insert the base end of the tube 31 into the receiving surface 32a of the rigid component 32, and place the first O-ring 33a against the front end surface 32c of the rigid component 32.

[0259] The heat shrink tube 34 is formed to cover the rigid component 32, the first O-ring 33a and the tube 31 but not the second O-ring 33b. The heat shrink tube 34 is heated to shrink it.

[0260] Next, the second O-ring 33b is moved to a position opposite the first O-ring 33a, separated by the heat shrink tube 34. Thus, the second O-ring 33b comes into contact with the outer peripheral surface 34c of the heat shrink tube 34 of the covering tube 31.

[0261] The third connection structure achieves the same effect as the first and second connection structures.

[0262] Furthermore, according to the third connection structure, since the second O-ring 33b is pressed from the outer periphery of the heat shrink tube 34, high water tightness can be ensured.

[0263] Figure 21 This is a cross-sectional view showing the fourth connection structure between the pipe 31 and the rigid component 32 in the related art. In the fourth connection structure, the same reference numerals are used for the parts that are the same as in the first to third connection structures, and the descriptions are omitted as appropriate. In the fourth connection structure, the differences from the first to third connection structures are mainly explained.

[0264] A flange 31a (second flange) is formed on the base end side of the pipe 31, protruding radially outward R about the central axis 30x of the pipe 30. An enlarged diameter portion 32b is provided at the front end of the through hole 32h of the rigid component 32. A receiving surface 32a is provided in the enlarged diameter portion 32b, which functions as a surface to receive the flange 31a. The flange 31a abuts against the enlarged diameter portion 32b.

[0265] A flange 32d (first flange) protruding radially outward R is formed on the front end side of the rigid component 32.

[0266] An O-ring 33 (first O-ring) is assembled on the outer peripheral surface 31c of the tube 31, which is closer to the front end of the flange 31a, in a manner that abuts against the flange 31a.

[0267] The base end of the tube 31, including the flange 31a, is inserted into the receiving surface 32a of the rigid component 32. At this time, the O-ring 33 is disposed together with the flange 31a in the enlarged diameter portion 32b. The O-ring 33 contacts the enlarged diameter portion 32b and the flange 31a on the inner circumferential side of the flange 32d.

[0268] The heat shrink tube 34 is formed so that it covers the outer peripheral surface of the rigid component 32 near the base end of the flange 32d, the O-ring 33, and the base end of the tube 31. The heat shrink tube 34 is then heated to shrink it.

[0269] The fourth connection structure achieves the same effect as the first to third connection structures.

[0270] In addition, according to the fourth connection structure, a flange 31a is provided on the base end side of the tube 31 and a flange 32d is provided on the front end side of the rigid member 32, thus ensuring high pull-out strength.

[0271] Figure 22 This is a cross-sectional view showing the fifth connection structure between the pipe 31 and the rigid component 32 in the related art. In the fifth connection structure, the same reference numerals are used for the parts that are the same as in the first to fourth connection structures, and the descriptions are omitted as appropriate. In the fifth connection structure, the differences from the first to fourth connection structures are mainly explained.

[0272] A flange 31b (second flange) protruding radially outward by R is formed on the base end side of the tube 31. An enlarged diameter portion 32b is provided at the front end of the through hole 32h of the rigid component 32. A receiving surface 32a is provided in the enlarged diameter portion 32b, which functions as a surface to receive the flange 31b. The flange 31b abuts against the enlarged diameter portion 32b.

[0273] A flange 32d (first flange) protruding radially outward R is formed on the front end side of the rigid component 32.

[0274] An O-ring 33 (first O-ring) is assembled on the outer peripheral surface 31c of the tube 31 near the front end of the flange 31b in a manner that abuts against the flange 31b.

[0275] The base end of the tube 31, including the flange 31b, is inserted into the receiving surface 32a of the rigid component 32. At this time, the outer diameter R2 of the O-ring 33 is larger than the diameter of the enlarged portion 32b. Therefore, the O-ring 33 is not housed within the enlarged portion 32b.

[0276] The length of the central axis 30x of the expanded diameter portion 32b is substantially the same as the length of the central axis 30x of the flange 31b. Therefore, the O-ring 33 contacts the front end face 32d1 of the flange 32d and the front end face 31b1 of the flange 31b.

[0277] The heat shrink tube 34 is formed so that it covers the outer peripheral surface of the rigid component 32 near the base end of the flange 32d, the O-ring 33, and the base end of the tube 31. The heat shrink tube 34 is then heated to shrink it.

[0278] The heat shrink tube 34 contacts the O-ring 33 and shrinks while covering the O-ring 33, compressing the O-ring 33 in the direction toward the central axis 30x of the pipe 30.

[0279] The relationship between the outer diameter R1 of the flange 31b, the outer diameter R2 of the O-ring 33, and the outer diameter R3 of the flange 32d (including the thickness of the heat shrink tube 34) after heat shrinking is R1 > R2 > R3.

[0280] The fifth connection structure achieves the same effect as the fourth connection structure.

[0281] According to the first to fifth connection structures, the connection structure between pipe 31 and rigid component 32 becomes simple, thus making the connection operation easier. Furthermore, due to the small number of components, pipe 31 and rigid component 32 can be connected at a low cost. Moreover, the use of O-rings 33, 33a, and 33b ensures the watertightness of the connection between pipe 31 and rigid component 32.

[0282] Furthermore, for example, by using a heat-shrink tube 34 with adhesive pre-applied to its inner circumferential surface, the application of adhesive is eliminated. Therefore, work time is reduced, and product deviations caused by work errors are minimized.

[0283] In addition, water tightness is ensured by O-rings 33, 33a, and 33b, and connection strength is ensured by heat shrink tubing 34, thereby enabling multiple components to share the function of durability.

[0284] Figure 23 This is a cross-sectional view showing the sixth connection structure between the pipe 31 and the rigid component 32 in the related art. In the sixth connection structure, the same reference numerals are used for the parts that are the same as in the first to fifth connection structures, and the descriptions are omitted as appropriate. The differences between the sixth connection structure and the first to fifth connection structures are mainly explained in the sixth connection structure.

[0285] A first recess 32e is provided midway through the through hole 32h of the rigid component 32. The first recess 32e is a recess extending radially outward from the inner surface 32h1 of the through hole 32h towards the outer surface R. Here, in the manufacturing process, it is easier to form a hole that extends to the outer surface of the rigid component 32 (i.e., not with a bottom) than to form a bottomed recess extending radially outward from the inner surface 32h1 of the through hole 32h towards the outer surface R. Therefore, in Figure 23 In the example shown, the first recess 32e is configured as a hole extending to the outer surface. However, it is not limited to this; the first recess 32e can also be configured as a recess with a bottom.

[0286] The first recess 32e is provided at one or more locations around the central axis 30x of the conduit 30, preferably at two or more locations. Therefore, in the portion where the first recess 32e is not provided, if the cross-section of the rigid member 32 including the central axis 30x is observed, there is no hole corresponding to the first recess 32e, and the wall thickness of the rigid member 32 remains in the cross-section.

[0287] The first hook 31h protrudes from the outer peripheral surface 31c of the pipe 31. Corresponding to the first recess 32e which is provided in one or more places, the first hook 31h is provided as one or more around the central axis 30x of the pipe 30, preferably two or more.

[0288] For example, as described later Figure 26 As shown in column A, the first hook 31h is formed as follows: a cut 31d is engraved on the tube 31 at an angle relative to the central axis 30x of the tube 30 (obliquely engraved towards the base end side of the tube 31 (base end direction P side)). (Refer to...) Figure 26 The A section is formed by making the engraved portion stand upright radially outward R. Therefore, the first hook 31h is integrally formed with the tube 31, for example. In addition, an example of an obliquely engraved cut 31d is given here, but it may not be oblique.

[0289] The first hook 31h is positioned in the upright state and hooked onto the first recess 32e. Because the first hook 31h is hooked onto the first recess 32e, it prevents the tube 31 from falling off the rigid component 32. Therefore, the first hook 31h functions as both a check valve and an anti-detachment shape.

[0290] As described above, the tube 31 is, for example, formed of resin. In the structure that prevents the tube 31 from detaching from the rigid component 32 by means of the first hook 31h provided on the tube 31, it is preferable to use a tube 31 with a softness of about 70 points when the hardness is measured using Shore A (hardness tester A) (A hardness is about 70). In addition, in order to make the detachment of the tube 31 from the rigid component 32 more secure, it is preferable to make the wall thickness of the tube 31 thicker.

[0291] A heat shrink tube 34 is disposed on the outer periphery of the tube 31 and the rigid member 32 (including the portion containing the first recess 32e). The heat shrink tube 34 contacts the rigid member 32 and the tube 31 and shrinks while covering the rigid member 32 and the tube 31. As described above, the heat shrink tube 34 is a heat shrink tube with adhesive pre-applied to its inner circumferential surface.

[0292] The operation of connecting the tube 31 to the rigid component 32 is performed, for example, by the following steps (1) to (4).

[0293] (1) Make a cut 31d on the tube 31 and set the first hook 31h.

[0294] (2) Insert the heat shrink tube 34 into the tube 31.

[0295] (3) Insert the base end of the tube 31 into the rigid component 32 and hook the first hook 31h onto the first recess 32e.

[0296] (4) The heat shrink tube 34 is formed to cover the base end of the tube 31 from the position of the rigid part 32 closer to the base end than the first recess 32e, and the heat shrink tube 34 is heated to shrink the heat shrink tube 34.

[0297] In this structure, the watertightness of the connection between the tube 31 and the rigid component 32 is ensured by using a heat-shrinkable tube 34 with adhesive applied to its inner surface. Furthermore, the connection strength between the tube 31 and the rigid component 32 is ensured by the first hook 31h on the tube 31 hooking onto the first recess 32e. In other words, watertightness and connection strength are achieved through different components.

[0298] According to the sixth connection structure, the water tightness and connection strength of the connection between the pipe 31 and the rigid component 32 can be ensured. At this time, the water tightness and connection strength can be ensured by combining the pipe 31 and the heat shrink tube 34 without using an O-ring.

[0299] Furthermore, according to the sixth connection structure, the connection structure between the pipe 31 and the rigid component 32 becomes simple, thus making the connection operation easier. In addition, since the number of components is small, the pipe 31 and the rigid component 32 can be connected at a low cost.

[0300] By using a heat-shrink tube 34 with adhesive pre-applied to its inner circumferential surface, the application of adhesive is eliminated. This reduces processing time and minimizes product deviations caused by operational errors.

[0301] Figure 24 This is a cross-sectional view showing the seventh connection structure between the pipe 31 and the rigid component 32 in the related art. In the seventh connection structure, the same reference numerals are used for the parts that are the same as in the first to sixth connection structures, and the descriptions are omitted as appropriate. The main differences between the seventh connection structure and the first to sixth connection structures are explained in the seventh connection structure.

[0302] A second recess 32f is provided all around the outer circumference of the rigid component 32. The range in the direction of the central axis 30x of the second recess 32f overlaps with the range in the direction of the central axis 30x of the first recess 32e. Preferably, the center position of the range in the direction of the central axis 30x of the second recess 32f coincides with the center position of the range in the direction of the central axis 30x of the first recess 32e. Furthermore, the sum of the depths of the first recess 32e and the second recess 32f in the wall thickness direction (the direction parallel to the radially outward R) of the rigid component 32 is consistent with the wall thickness of the rigid component 32.

[0303] Therefore, the second recess 32f communicates with the first recess 32e. Thus, the through hole 32h communicates with the outer peripheral surface 32k side of the rigid component 32 via the first recess 32e and the second recess 32f.

[0304] A first O-ring 33a is disposed in the second recess 32f. The first O-ring 33a watertightly seals the hole through which the second recess 32f communicates with the first recess 32e.

[0305] Furthermore, an enlarged diameter portion 32b is provided at the opening at the front end of the through hole 32h. A second O-ring 33b is disposed in the enlarged diameter portion 32b and is externally embedded in the tube 31. The second O-ring 33b contacts the rigid component 32 and the outer peripheral surface 31c of the tube 31.

[0306] The heat shrink tube 34 is configured and shrinks to cover the outer surfaces of the tube 31, the rigid component 32, the first O-ring 33a, and the second O-ring 33b. Therefore, the heat shrink tube 34 covers the second recess 32f where the first O-ring 33a is disposed.

[0307] According to the seventh connection structure, similarly to the sixth connection structure, water tightness and connection strength can be ensured. Furthermore, according to the seventh connection structure, by auxiliaryly using the first O-ring 33a and the second O-ring 33b, water tightness can be improved compared to the sixth connection structure.

[0308] Figure 25 This is a cross-sectional view showing the eighth connection structure between the pipe 31 and the rigid component 32 in the related art. In the eighth connection structure, the same reference numerals are used for the parts that are the same as in the first to seventh connection structures, and the descriptions are omitted as appropriate. In the eighth connection structure, the differences from the first to seventh connection structures are mainly explained.

[0309] An enlarged diameter portion 32b is provided at the opening at the front end of the through hole 32h. A receiving surface 32a is formed in the enlarged diameter portion 32b, which receives the base end of the tube 31 inserted into the rigid component 32. The base end side of the tube 31 is disposed within the enlarged diameter portion 32b. The inner diameter of the enlarged diameter portion 32b is larger than the outer diameter of the tube 31, creating a space between the enlarged diameter portion 32b and the tube 31.

[0310] A ring member 35 is disposed in the space between the enlarged diameter section 32b and the tube 31, and is arranged around the central axis 30x. The ring member 35 is formed of a material, such as metal, that is harder than the rigid member 32 and the tube 31.

[0311] The ring component 35 has a first hook 35a that hooks onto the enlarged diameter portion 32b and a second hook 35b that hooks onto the tube 31. One or more sets of the first hook 35a and the second hook 35b are provided around the central axis 30x, preferably two or more sets.

[0312] The heat shrink tube 34 contacts the rigid component 32 and the tube 31, and shrinks while covering the rigid component 32 and the tube 31. Therefore, the space between the enlarged diameter portion 32b, where the ring component 35 is disposed, and the tube 31 is also sealed watertight with respect to the outside by the heat shrink tube 34.

[0313] According to the eighth connection structure, by using the ring member 35, which is provided as a component other than the tube 31 and the rigid member 32, the connection strength can be ensured in the same way as the sixth and seventh connection structures. In addition, since the ring member 35 is used, the manufacturing process of processing the tube 31 can be omitted.

[0314] Figure 26 This diagram illustrates the manufacturing method of the tube 31 involved in the ninth connection structure between the tube 31 and the rigid component 32 in the related art. In the ninth connection structure, the same reference numerals are used for the parts that are the same as in the first to eighth connection structures, and the descriptions are omitted as appropriate. In the ninth connection structure, the differences from the first to eighth connection structures are mainly explained.

[0315] like Figure 26As shown in column A, a cut 31d is engraved on the tube 31 at an angle relative to, for example, the central axis 30x of the tube 30 (engraved obliquely towards the base end of the tube 31). A first hook 31h is formed on the tube 31 through the cut 31d. In the following description, an example is given in which a pair of cuts 31d are provided at the top and bottom, and a pair of first hooks 31h are provided at the top and bottom.

[0316] like Figure 26 As shown in column B, a ring member 36 is disposed on the outer peripheral surface 31c of the tube 31, which is closer to the front end (front end direction D side) than the first hook 31h. Then, an up-down compressive force (up-down compressive force toward the central axis 30x) is applied to the tube 31 closer to the front end of the first hook 31h, as shown by arrow F1, and a left-right compressive force (left-right compressive force toward the central axis 30x) is applied to the tube 31 closer to the base end (base end direction P side), as shown by arrow F2. Thus, as shown by arrow A1, the upper first hook 31h stands upright from the outer peripheral surface 31c upward (radially outward R), and the lower first hook 31h stands upright from the outer peripheral surface 31c downward (radially outward R).

[0317] In this state, the ring member 36 is moved towards the base end side (base end direction P side) and contacts the inner surface 31h1 of the first hook 31h. Thus, the upper and lower pair of first hooks 31h are maintained in a state where they stand upright from the outer peripheral surface 31c of the tube 31. At this time, the degree of uprightness of the first hook 31h can be adjusted to some extent depending on the depth of contact between the ring member 36 and the inner surface 31h1 of the first hook 31h.

[0318] By using, such Figure 26 The ring component 36 shown is used in the ninth connection structure where the tube 31, which causes the first hook 31h to stand upright, is applied. Figure 23 or Figure 24 The structure shown can more reliably prevent the tube 31 from detaching from the rigid component 32. Thus, according to the ninth connection structure, the connection strength between the tube 31 and the rigid component 32 can be further improved.

[0319] Furthermore, the connection strength can be adjusted by adjusting the contact state between the ring component 36 and the inner surface 31h1 of the first hook 31h.

[0320] [Additional Notes]

[0321] Based on the above description in relation to embodiments of the present invention, the following structure can be obtained.

[0322] [Postscript A1]

[0323] An endoscope having a flexible tube, The flexible tube is a tube extending along a central axis from one end to the other. The flexible tube comprises: Multiple convex surfaces are disposed on the outer peripheral surface; and A concave surface, which is disposed on the outer peripheral surface and defined by the plurality of convex surfaces, Each of the plurality of convex surfaces is isolated from the others by being surrounded by the concave surface. The concave surface is inclined entirely relative to the axial direction parallel to the central axis and also inclined relative to the circumferential direction about the central axis.

[0324] [Note A2]

[0325] In the endoscope described in Appendix A1 When the outer peripheral surface is unfolded into a plane, the plurality of convex surfaces are each quadrilateral.

[0326] [Note A3]

[0327] In the endoscope described in Appendix A1 When the outer peripheral surface is unfolded into a plane, the plurality of convex surfaces are respectively rhomboid in shape.

[0328] [Notes A4]

[0329] In the endoscope described in Appendix A1 When the outer peripheral surface is unfolded into a plane, the plurality of convex surfaces are each rectangular.

[0330] [Note A5]

[0331] A flexible tube is a tube that runs along a central axis extending from one end to the other. Flexible tubes have the following features: Multiple convex surfaces are disposed on the outer peripheral surface; and A concave surface, which is disposed on the outer peripheral surface and defined by the plurality of convex surfaces, Each of the plurality of convex surfaces is isolated from the others by being surrounded by the concave surface. In the case where the concave surface includes a first portion along an axial direction parallel to the central axis, the first portion is formed intermittently along the axial direction. In the case where the concave surface includes a second portion along the circumferential direction about the central axis, the second portion is formed intermittently in the circumferential direction.

[0332] [Postscript B1]

[0333] An endoscope, characterized in that it comprises: A rigid component having a through hole that forms part of a conduit; The tube, with its base end disposed within the through hole, forms another part of the pipeline; A first O-ring, which contacts the rigid component and the tube; and A heat-shrinkable tube that contacts the rigid component and the tube to shrink and cover the rigid component and the tube.

[0334] [Note B2]

[0335] In the endoscope described in Appendix B1, the characteristic is that, The endoscope also has an enlarged diameter section disposed at the front end of the through hole. The first O-ring is disposed on the enlarged diameter portion and contacts the outer peripheral surface of the tube.

[0336] [Note B3]

[0337] In the endoscope described in Appendix B1, the characteristic is that, The endoscope also has a second O-ring, which is positioned further forward than the first O-ring and contacts the outer peripheral surface of the tube. The heat shrink tube also contacts the second O-ring, shrinks while covering the second O-ring, and compresses the second O-ring toward the central axis of the pipeline.

[0338] [Postscript B4]

[0339] In the endoscope described in Appendix B1, the characteristic is that, The endoscope also has a second O-ring that contacts the outer peripheral surface of the heat-shrinkable tube covering the tube.

[0340] [Postscript B5]

[0341] In the endoscope described in Appendix B1, the characteristic is that, The endoscope also features: A first flange is disposed on the front end side of the rigid component; An enlarged diameter portion is disposed at the front end of the through hole; and The second flange is located at the base end of the tube and abuts against the enlarged diameter portion. The first O-ring is disposed on the enlarged diameter portion and contacts the enlarged diameter portion and the second flange on the inner circumferential side of the first flange.

[0342] [Postscript B6]

[0343] In the endoscope described in Appendix B1, the characteristic is that, The endoscope also features: A first flange is disposed on the front end side of the rigid component; An enlarged diameter portion is disposed at the front end of the through hole; and The second flange is located at the base end of the tube and abuts against the enlarged diameter portion. The first O-ring contacts the front end face of the first flange and the front end face of the second flange. The heat shrink tube also contacts the first O-ring, shrinks while covering the first O-ring, and compresses the first O-ring toward the central axis of the pipeline.

[0344] [Postscript C1]

[0345] An endoscope, characterized in that it comprises: A rigid component having a through hole that forms part of a conduit; The tube, with its base end disposed within the through hole, forms another part of the pipeline; A first recess is provided at one or more points around the central axis of the conduit, midway through the through hole of the rigid component, and extends radially outward from the inner surface of the through hole. A first hook protrudes from the outer peripheral surface of the tube and is disposed in the first recess, hooking onto the first recess; and A heat-shrinkable tube that contacts the rigid component and the tube, and shrinks to cover the rigid component and the tube.

[0346] [Note C2]

[0347] In the endoscope described in Appendix C1, the characteristic is that, The first hook is formed by making a cut in the tube that is inclined relative to the central axis of the tube and making the cut portion stand out radially outward, and the first hook is integral with the tube.

[0348] [Postscript C3]

[0349] In the endoscope described in Appendix C1, the characteristic is that, The endoscope also features: A second recess is provided covering the entire circumference of the outer peripheral surface of the rigid component and communicating with the first recess; and An O-ring, which is disposed in the second recess. The heat shrink tube also covers the second recess where the O-ring is configured.

[0350] [Postscript C4]

[0351] In the endoscope described in Appendix C1, the characteristic is that, The endoscope also includes a ring component disposed on the outer peripheral surface of the tube and in contact with the inner surface of the first hook, so that the first hook stands upright from the outer peripheral surface of the tube.

[0352] [Postscript D1]

[0353] An endoscope, characterized in that it comprises: A rigid component having a through hole that forms part of a pipeline, with an enlarged diameter section provided at the front end of the through hole; The tube, with its base end disposed within the enlarged diameter section, forms another part of the pipeline; A ring component, formed of a material harder than the rigid component and the tube, is disposed between the enlarged portion and the tube; and A heat-shrinkable tube, which contacts the rigid component and the tube, shrinks to cover the rigid component and the tube. The ring component has a first hook that hooks onto the enlarged diameter portion and a second hook that hooks onto the tube.

[0354] Furthermore, this invention is not directly limited to the embodiments described above. During implementation, the constituent elements can be modified and embodied by variations without departing from the spirit of the invention. Additionally, various inventive methods can be formed by appropriately combining multiple constituent elements disclosed in the above embodiments. For example, some constituent elements may be deleted from all the constituent elements disclosed in the embodiments. Furthermore, constituent elements from different embodiments may be appropriately combined. Thus, various modifications and applications are naturally possible without departing from the spirit of the invention.

[0355] This application is based on priority claim of U.S. Provisional Application No. 63 / 599292, filed November 15, 2023, the contents of which are incorporated herein by reference in the specification, claims and drawings.

Claims

1. An endoscope having a flexible tube, The flexible tube is a tube that extends along a central axis from one end to the other. The flexible tube comprises: Multiple convex surfaces are disposed on the outer peripheral surface; and A concave surface, which is disposed on the outer peripheral surface and defined by the plurality of convex surfaces, Each of the plurality of convex surfaces is isolated from the others by being surrounded by the concave surface. In the case where the concave surface includes a first portion along an axial direction parallel to the central axis, the first portion is formed intermittently along the axial direction. In the case where the concave surface includes a second portion along the circumferential direction about the central axis, the second portion is formed intermittently in the circumferential direction.

2. The endoscope according to claim 1, wherein, The plurality of convex surfaces each have the same shape.

3. The endoscope according to claim 2, wherein, When the outer peripheral surface is unfolded into a plane, the plurality of convex surfaces are each polygonal.

4. The endoscope according to claim 2, wherein, When the outer peripheral surface is unfolded into a plane, the plurality of convex surfaces are respectively rounded polygons.

5. The endoscope according to claim 3, wherein, The concave surface has a portion that is inclined relative to the axial direction. The inclined portion forms an angle of less than 45° with the axial direction.

6. The endoscope according to claim 3, wherein, When the outer peripheral surface is unfolded into a plane, the plurality of convex surfaces are each quadrilateral.

7. The endoscope according to claim 6, wherein, When the outer peripheral surface is unfolded into a plane, the plurality of convex surfaces are respectively rhomboid in shape.

8. The endoscope according to claim 6, wherein, When the outer peripheral surface is unfolded into a plane, the plurality of convex surfaces are each rectangular.

9. The endoscope according to claim 2, wherein, When the outer peripheral surface is unfolded into a plane, the plurality of convex surfaces are respectively T-shaped.

10. The endoscope according to claim 2, wherein, When the outer peripheral surface is unfolded into a plane, the plurality of convex surfaces are respectively L-shaped.

11. The endoscope according to claim 3, wherein, When the outer peripheral surface is unfolded into a plane, the plurality of convex surfaces are each triangular.

12. The endoscope according to claim 2, wherein, The flexible tube comprises: The tube body, formed of a material of first Young's modulus, is provided with the plurality of convex surfaces and the concave surfaces; and The filling structure portion, which fills the concave surface of the tube body, is formed of a filling material with a second Young's modulus that is lower than the first Young's modulus.

13. The endoscope according to claim 12, wherein, The filling ratio of the filling material in the filling structure portion varies along the axial direction.

14. The endoscope according to claim 2, wherein, The radial distances from the concave surface to the plurality of convex surfaces, centered on the central axis, are all different.

15. The endoscope according to claim 1, wherein, The endoscope has an insertion part for inserting into the subject. The flexible tube is disposed at the insertion portion.

16. The endoscope according to claim 1, wherein, The plurality of convex surfaces are arranged periodically along the outer peripheral surface.

17. The endoscope according to claim 1, wherein, The plurality of convex surfaces are arranged non-periodically along the outer peripheral surface.

18. The endoscope according to claim 1, wherein, The concave surface includes at least one of the first portion and the second portion.

19. The endoscope according to claim 1, wherein, Within a first range along the axial direction, the plurality of convex surfaces each have a first shape. In a second range along the axial direction, different from the first range, the plurality of convex surfaces each have a second shape different from the first shape.

20. An endoscope having a flexible tube, The flexible tube is a tube that extends along a central axis from one end to the other. The flexible tube comprises: Multiple convex surfaces are disposed on the outer peripheral surface; and A concave surface, which is disposed on the outer peripheral surface and defined by the plurality of convex surfaces, Each of the plurality of convex surfaces is isolated from the others by being surrounded by the concave surface. The concave surface is inclined entirely relative to the axial direction parallel to the central axis and also inclined relative to the circumferential direction about the central axis.

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