Bending mechanism and endoscope

Abstract

The bending mechanism (20) has a first tube (2b), a first guide (24), and a second guide (22). The first tube (2b) is formed along an axis (O) and is bent by pulling of a wire (23). The first guide (24) is formed in a cylindrical shape by resin, is provided to the first tube (2b) along the axis (O), and holds the wire (23). The second guide (22) is fixed to the first tube (2b) and holds the first guide (24).

Description

Technical Field

[0001] The present invention relates to a bending mechanism that bends by the traction of a wire and an endoscope having the bending mechanism. Background Technology

[0002] Previously, endoscopes with a bending mechanism capable of changing the direction of the tip have been proposed. The bending mechanism is constructed by oscillatingly connecting and arranging multiple bending blocks within a bending section, and fixing, for example, the tip of a bending wire to the bending block located at the foremost end. The bending wire passes through a wire receiving member provided in the bending block within the bending section. The bending wire passes through a tubular portion at the base end of the bending section, and the base end of the bending wire is connected to a cylinder or similar component within the operating section. The cylinder within the operating section rotates in conjunction with a bending operation knob, pulling the bending wire. As a result, the bending section bends by operating the bending operation knob.

[0003] For example, International Publication No. WO2016-167099 describes a curved tube for endoscopes, which is formed by connecting multiple ring components with multiple tubular components. Specifically, the technology described in this publication adopts a structure that uses tubular components to connect multiple curved blocks, instead of a general structure that uses hinges or the like to connect multiple curved blocks.

[0004] When the endoscope's insertion section is inserted into the patient's body, the curved section may sometimes take on a complex shape such as a ring. If the curved wire is pulled in this state, friction and jamming will occur between the curved wire and the wire holder, increasing the sliding resistance.

[0005] As a result, the traction force of the bending line is lost at the wire receiving part, and the operating force required to operate the bending operation knob increases due to the sliding resistance, reducing operability. In addition, wear and scraping sometimes occur at the corners of the wire receiving part that contacts the bending line.

[0006] In response to this, there are known techniques that use powdered lubricants to reduce sliding resistance, enabling bending operations to be performed easily with less operating force.

[0007] Endoscopes are typically manufactured in cleanrooms or other controlled areas, but powdered lubricants cannot be brought into such areas. Therefore, using powdered lubricants reduces manufacturing flexibility, increases manufacturing costs, and complicates assembly line construction.

[0008] The present invention was made in view of the above circumstances, and its object is to provide a low-cost bending mechanism that can be easily bent with a small operating force, and an endoscope having the bending mechanism. Summary of the Invention

[0009] Methods for solving problems

[0010] One aspect of the bending mechanism of the present invention comprises: a first tube formed along an axis extending from a first side to a second side and configured to be bent by the traction of a line; a first guide formed of resin in a cylindrical shape and disposed along the axis in the first tube to hold the line; and a second guide fixed to the first tube to hold the first guide.

[0011] An endoscope according to one aspect of the present invention comprises: an insertion portion configured to be inserted into a subject; an operating portion disposed at a position closer to a first side than the insertion portion; and a bending mechanism at least a portion disposed on a second side of the insertion portion, the bending mechanism comprising: a first tube formed along an axis extending from the first side to the second side and configured to be bent by the traction of a wire; a first guide formed of resin in a cylindrical shape and disposed along the axis in the first tube to hold the wire; and a second guide fixed to the first tube to hold the first guide, the first side of the wire being connected to the operating portion. Attached Figure Description

[0012] Figure 1 This is a diagram illustrating structural examples of endoscopes according to various embodiments of the present invention.

[0013] Figure 2 This is a perspective view of a flexible tube, representing the first example of the related technology.

[0014] Figure 3 This is a perspective view of a modified example of a flexible tube, representing the first example of the related technology.

[0015] Figure 4 This is a diagram showing the structure when the outer peripheral surface of the first example of the related technology is unfolded into a plane.

[0016] Figure 5 This is a diagram showing the structure when the outer peripheral surface of the flexible tube in the second example of the related technology is unfolded into a plane.

[0017] Figure 6 This is a three-dimensional view of a flexible tube, representing the third example of the related technology.

[0018] Figure 7 This is a diagram showing the structure when the outer peripheral surface of the flexible tube in the third example of the related technology is unfolded into a plane.

[0019] Figure 8 This is a diagram showing the structure when the outer peripheral surface of the flexible tube in the fourth example of the related technology is unfolded into a plane.

[0020] Figure 9 This is a diagram showing the structure when the outer peripheral surface of the flexible tube in the fifth example of the related technology is unfolded into a plane.

[0021] Figure 10 This is a diagram showing the structure when the outer peripheral surface of the flexible tube in the sixth example of the related technology is unfolded into a plane.

[0022] Figure 11 This is a diagram showing the structure when the outer peripheral surface of the flexible tube in the seventh example of the related technology is unfolded into a plane.

[0023] Figure 12 This is a diagram showing the structure when the outer peripheral surface of the flexible tube in the eighth example of the related technology is unfolded into a plane.

[0024] Figure 13 This is a diagram showing the structure when the outer peripheral surface of the flexible tube in the ninth example of the related technology is unfolded into a plane.

[0025] Figure 14 This is a diagram showing the structure when the outer peripheral surface of the flexible tube in the tenth example of the related technology is unfolded into a plane.

[0026] Figure 15 This is a perspective view of the eleventh example of a flexible tube representing related technology.

[0027] Figure 16 This is a three-dimensional view of the twelfth example of the related technology, a flexible tube.

[0028] Figure 17 This is a three-dimensional view of the thirteenth example of the related technology, a flexible tube.

[0029] Figure 18 This is a cross-sectional view showing a structural example of the bending line in the bending portion of the first embodiment of the present invention.

[0030] Figure 19 This is a partial perspective view showing a structural example of the bending line in the bending portion of the first embodiment described above.

[0031] Figure 20 This is a diagram comparing the relationship between the curved line and the wire receiving member inserted into the pipe in the first embodiment described above and the relationship between the curved line and the wire receiving member in the conventional embodiment.

[0032] Figure 21 This is a cross-sectional view of the structure of the tube through which the bending line is inserted in the curved section representing the straight state in the first embodiment described above.

[0033] Figure 22 This is a cross-sectional view of the state of the tube through which the bending line is inserted in the bending section, which represents the maximum bending state in the first embodiment described above.

[0034] Figure 23 This is a cross-sectional view of the structure of a tube for the insertion of a bending line in a curved section representing a straight state, as shown in the second embodiment of the present invention.

[0035] Figure 24 This is a cross-sectional view of the state of the tube through which the bending line is inserted in the bending section, which represents the maximum bending state in the second embodiment described above.

[0036] Figure 25 This is a cross-sectional view parallel to the central axis, showing a modified example of a segmented tube constituting an intermittent tube in the second embodiment described above.

[0037] Figure 26 This is a cross-sectional view perpendicular to the central axis, showing the structure of the tube through which the curved line is inserted, in the third embodiment of the present invention.

[0038] Figure 27 This is a diagram illustrating a structural example in the fourth embodiment of the present invention where a wire-receiving member is integrally provided on the bending block.

[0039] Figure 28 This is a diagram illustrating the structure of a tube for the insertion of a curved line, as shown in the fifth embodiment of the present invention.

[0040] Figure 29 This is a diagram illustrating the structure of a tube for the insertion of a curved line, as shown in the sixth embodiment of the present invention.

[0041] Figure 30 This is a diagram illustrating the structure of a tube for the insertion of a curved line, as shown in the seventh embodiment of the present invention.

[0042] Figure 31 This is a diagram illustrating the case of a tube when the bend is bent, according to the eighth embodiment of the present invention.

[0043] Figure 32 This is a perspective view of the first structural example of the tube in the eighth embodiment described above.

[0044] Figure 33 This is a diagram showing the cross-section and partially enlarged side view of the tube in the eighth embodiment described above.

[0045] Figure 34 This is a perspective view of a second structural example of the tube in the eighth embodiment described above.

[0046] Figure 35 This is a diagram showing the cross-section and partially enlarged side view of the tube in the eighth embodiment described above.

[0047] Figure 36 This is a partial perspective view showing the structure of the wire support member in the bending block according to the ninth embodiment of the present invention.

[0048] Figure 37 This is a partial perspective view showing the structure of the wire-receiving member in the bending block of a modified example of the ninth embodiment described above. Detailed Implementation

[0049] Hereinafter, 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.

[0050] 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, among multiple drawings, there may sometimes be differences in length relationships, ratios, quantities, etc., between them.

[0051] Figure 1 This is a diagram illustrating an example structure of the endoscope 1 according to various embodiments of the present invention.

[0052] Endoscope 1 is a device for observing and treating a subject. Endoscope 1 includes: an insertion part 2, which is inserted into the subject; and an operating part 3, which is disposed at the base of the insertion part 2 (first side). Figure 21 (the base end direction P side); and a general cable 4, which extends from the operating part 3.

[0053] 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.

[0054] The insertion part 2 has a front end 2a, a curved part 2b (curved tube, first tube) and a tubular part 2c (second tube) in sequence from the front end toward the base end.

[0055] 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.

[0056] 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.

[0057] 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.

[0058] 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.

[0059] The holding part 3a is the part where the operator holds the endoscope 1 with their palm.

[0060] 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.

[0061] Multiple operation buttons 3c include, for example, the air / water supply button 3c1, the suction button 3c2, and other button types 3c3, etc.

[0062] The air and water supply button 3c1 is used to perform the following operation: 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).

[0063] 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).

[0064] 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.

[0065] 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.

[0066] 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.

[0067] 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.

[0068] 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.

[0069] Next, refer to Figures 2 to 17 The flexible tube 5 used in endoscope 1 will be described as a related technology.

[0070] 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.

[0071] 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.

[0072] 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.

[0073] 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.

[0074] 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.

[0075] In the following related technologies, an endoscope having a flexible tube that can achieve a balance of flexibility, stretchability, and torque resistance and can be manufactured at a low cost will be described.

[0076] [First example of related technology]

[0077] Figures 2-4 This represents the first example of a related technology. Figure 2 This is a perspective view of a flexible tube 5, representing the first example of the related technology.

[0078] 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.

[0079] 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.

[0080] 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.

[0081] 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.

[0082] 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.

[0083] 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.

[0084] Specifically Figure 2In 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.

[0085] 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.

[0086] 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.

[0087] in addition, Figure 3 This is a perspective view of a modified example of the flexible tube 5, which represents the first example of the related technology.

[0088] 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.

[0089] Figure 4 This is a diagram showing the structure when the outer peripheral surface 5A of the flexible tube 5 of the first example of the related technology 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.

[0090] 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).

[0091] 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.

[0092] 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.

[0093] 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°.

[0094] 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.

[0095] 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°.

[0096] 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.

[0097] 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.

[0098] That is, the flexible tube 5 can also have a tube body 8 and a filling structure part 9.

[0099] 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.

[0100] 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.

[0101] 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.

[0102] 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.

[0103] 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.

[0104] 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.

[0105] According to the first example of the related technology, the flexible tube 5 is formed with a structure having multiple convex surfaces 6 that are surrounded by concave surfaces 7 and isolated from each other. Thus, the flexible tube 5 of this example 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.

[0106] Compared to a corrugated tube with a corrugated structure, the surface smoothness of the flexible tube 5 in this example 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 patient.

[0107] The flexible tube 5 in this example has a concave surface 7 that is inclined relative to the axial direction and relative to the circumferential direction, thus improving the tensile strength while maintaining flexibility.

[0108] The flexible tube 5 in this example allows for more flexible control over the balance of bending resistance, tensile strength, 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 characteristics.

[0109] 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.

[0110] Similar to conventional corrugated pipes, the flexible pipe 5 in this example can be manufactured at low cost using an extruder and a mold equipped with a vacuum mechanism.

[0111] [Second example of related technology]

[0112] Figure 5 This diagram illustrates the structure of the flexible tube 5 with its outer peripheral surface 5A unfolded into a plane in the second example of the related art. In the second example of the related art, the same reference numerals are used for parts identical to those in the first example of the related art, and explanations are omitted where appropriate. The second example of the related art primarily explains the differences from the first example of the related art.

[0113] 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.

[0114] 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.

[0115] 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 dashed line.

[0116] 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°.

[0117] The second example of the related technology achieves roughly the same effect as the first example of the related technology.

[0118] Furthermore, in the first example of the related technology, the spiral-shaped first inclined portion 7a1 and the second inclined portion 7a2 are continuous in the axial direction of the flexible tube 5. In contrast, in the second example of the related technology, the first inclined portion 7b1 and the second inclined portion 7b2 are formed discontinuously in the axial direction. As a result, the flexible tube 5 of the second example of the related technology can further improve the degree of freedom of control over characteristics such as bending resistance, tensile strength, and torque resistance.

[0119] In addition, Figure 5In 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.

[0120] [The third example of related technology]

[0121] Figure 6 and Figure 7 This is the third example representing the relevant technology. Figure 6 This is a perspective view of the flexible tube 5, representing the third example of the related technology. Figure 7 This is a diagram showing the structure when the outer peripheral surface 5A of the flexible tube 5 in the third example of the related technology is unfolded into a plane.

[0122] In the third example of related technology, the parts that are the same as those in the first and second examples of related technology are labeled with the same numbers and the descriptions are omitted appropriately. In the third example of related technology, the differences from the first and second examples of related technology are mainly explained.

[0123] 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°.

[0124] 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.

[0125] 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.

[0126] 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.

[0127] 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.

[0128] According to the third example of the related technology, it achieves roughly the same effect as the first and second examples of the related technology.

[0129] Furthermore, according to a third example of the related technology, 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 for controlling the properties can be increased.

[0130] [Fourth example of related technology]

[0131] Figure 8 This diagram illustrates the structure of the flexible tube 5 with its outer peripheral surface 5A unfolded into a plane in the fourth example of the related art. In the fourth example of the related art, the same reference numerals are used for parts identical to those in the first to third examples of the related art, and explanations are omitted where appropriate. The fourth example of the related art primarily explains the differences from the first to third examples of the related art.

[0132] like Figure 8 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 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°.

[0133] 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.

[0134] 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.

[0135] 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.

[0136] 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.

[0137] According to the fourth example of the related technology, it achieves roughly the same effect as the first to third examples of the related technology.

[0138] Furthermore, according to a fourth example of the related technology, 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 increased.

[0139] [Fifth example of related technology]

[0140] Figure 9 This diagram illustrates the structure of the flexible tube 5 with its outer peripheral surface 5A unfolded into a plane in the fifth example of the related art. In the fifth example of the related art, the same reference numerals are used for parts identical to those in the first to fourth examples of the related art, and explanations are appropriately omitted. The fifth example of the related art primarily explains the differences from the first to fourth examples of the related art.

[0141] 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.

[0142] Figure 9The 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°).

[0143] 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.

[0144] 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°.

[0145] 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.

[0146] According to the fifth example of the related technology, it achieves roughly the same effect as the first to fourth examples of the related technology.

[0147] Furthermore, according to the fifth example of the related technology, a first part 7e1, a second part 7e2, and a third part 7e3 with different orientations are provided. Therefore, by adjusting the depth, length, width, etc. of the first part 7e1, the second part 7e2, and the third part 7e3, the degree of freedom in controlling the properties can be improved.

[0148] [Sixth example of related technology]

[0149] Figure 10This diagram illustrates the structure of the flexible tube 5 with its outer peripheral surface 5A unfolded into a plane in the sixth example of the related art. In the sixth example of the related art, the same reference numerals are used for parts identical to those in the first to fifth examples of the related art, and explanations are appropriately omitted. The sixth example of the related art primarily explains the differences from the first to fifth examples of the related art.

[0150] 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).

[0151] That is, in this example, the flexible tube 5 is constructed by using a triangle 6f instead of a triangle. Figure 9 The fifth example of the related technology shown is a rounded triangle 6e.

[0152] 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.

[0153] 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.

[0154] 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°.

[0155] 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.

[0156] According to the sixth example of the related technology, it achieves roughly the same effect as the first to fifth examples of the related technology.

[0157] Furthermore, according to the sixth example of the related technology, a first part 7f1, a second part 7f2, and a third part 7f3 with different orientations are provided. Therefore, by adjusting the depth, length, width, etc. of the first part 7f1, the second part 7f2, and the third part 7f3, the degree of freedom in controlling the properties can be improved.

[0158] [Seventh example of related technology]

[0159] Figure 11 This diagram illustrates the structure of the flexible tube 5 with its outer peripheral surface 5A unfolded into a plane in the seventh example of the related art. In the seventh example of the related art, the same reference numerals are used for parts identical to those in the first to sixth examples of the related art, and explanations are appropriately omitted. The seventh example of the related art primarily explains the differences from the first to sixth examples of the related art.

[0160] 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).

[0161] 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.

[0162] 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.

[0163] According to the seventh example of the related technology, it achieves roughly the same effect as the first to sixth examples of the related technology.

[0164] Furthermore, according to the seventh example of the related technology, 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 of control over the characteristics can be improved.

[0165] [The eighth example of related technologies]

[0166] Figure 12This diagram illustrates the structure of the flexible tube 5 with its outer peripheral surface 5A unfolded into a plane in the eighth example of the related art. In the eighth example of the related art, the same reference numerals are used for parts identical to those in the first to seventh examples of the related art, and explanations are appropriately omitted. The eighth example of the related art primarily explains the differences from the first to seventh examples of the related art.

[0167] In the first to seventh examples of related technologies, the multiple convex surfaces 6 each have the same shape. In contrast, in this example, the convex surfaces 6 are configured to combine two different shapes, and planar filling is performed based on the convex surfaces 6.

[0168] 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).

[0169] 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.

[0170] 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.

[0171] 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.

[0172] 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.

[0173] According to the eighth example of the related technology, it achieves roughly the same effect as the first to seventh examples of the related technology.

[0174] Furthermore, according to the eighth example of the related technology, 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 of control over the characteristics can be improved.

[0175] 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.

[0176] [The Ninth Example of Related Technologies]

[0177] Figure 13 This diagram illustrates the structure of the flexible tube 5 with its outer peripheral surface 5A unfolded into a plane in the ninth example of the related art. In the ninth example of the related art, the same reference numerals are used for parts identical to those in the first to eighth examples of the related art, and explanations are appropriately omitted. The ninth example of the related art primarily explains the differences from the first to eighth examples of the related art.

[0178] In the first to seventh examples of the related art, a convex surface 6 of one shape is arranged periodically, and in the eighth example of the related art, two convex surfaces 6 of different shapes are arranged periodically. In contrast, in this example, a convex surface of one shape is arranged non-periodically, and planar filling based on the convex surface 6 is performed.

[0179] 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.

[0180] Specifically, the concave 13-sided polygon 6i is also known as "Smith's Hat," as documented on the following website, for example.

[0181] 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)

[0182] In addition, the concave surface 7 is positioned between adjacent concave thiagons 6i.

[0183] 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.

[0184] 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)

[0185] 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.

[0186] According to the ninth example of the related technology, it achieves roughly the same effect as the first to eighth examples of the related technology.

[0187] Furthermore, according to the ninth example of the related technology, it is possible to obtain characteristics that are roughly uniform from a global perspective but non-uniform from a local perspective.

[0188] [The Tenth Example of Related Technologies]

[0189] Figure 14 This diagram illustrates the structure of the flexible tube 5 with its outer peripheral surface 5A unfolded into a plane in the tenth example of the related art. In the tenth example of the related art, the same reference numerals are used for parts identical to those in the first to ninth examples of the related art, and explanations are omitted where appropriate. The tenth example of the related art primarily explains the differences from the first to ninth examples of the related art.

[0190] In the first to ninth examples of the related art, 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, in this example, the two-dimensional shape of the convex surface 6 (and consequently the concave surface 7) varies along the axial direction.

[0191] 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.

[0192] 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).

[0193] 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.

[0194] 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.

[0195] 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.

[0196] 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.

[0197] 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.

[0198] 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.

[0199] 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.

[0200] 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.

[0201] 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.

[0202] 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 that is different from the first shape.

[0203] 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.

[0204] According to the tenth example of the related technology, it achieves roughly the same effect as the first to ninth examples of the related technology.

[0205] Furthermore, according to the tenth example of the related technology, the shape patterns of the convex surface 6 and the concave surface 7 are varied in the axial direction. 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.

[0206] [Eleventh example of related technology]

[0207] Figure 15 This is a perspective view of the flexible tube 5, representing the eleventh example of the related art. In this eleventh example, the parts that are the same as those in the first to tenth examples of the related art are labeled with the same reference numerals, and the descriptions are omitted as appropriate. In this eleventh example of the related art, the differences from the first to tenth examples of the related art are mainly explained.

[0208] The flexible tubes 5 of the first to tenth examples of the related art have multiple convex surfaces 6, each surrounded by a concave surface 7 and isolated from each other. In contrast, the flexible tube 5 of this example is formed by connecting multiple convex surfaces 6 that are annular in the circumferential direction in the axial direction.

[0209] 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.

[0210] 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.

[0211] 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.

[0212] 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.

[0213] 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.

[0214] exist Figure 15 In the first example shown, multiple connecting convex surfaces 6q are arranged circumferentially in a spaced-out manner. The connecting convex surfaces 6q are connected to the two convex surfaces 6p at fixed angles.

[0215] 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.

[0216] 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 arranged in an intersecting configuration. 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.

[0217] 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 of the convex surfaces 6p. Additionally, the converging portion of the connecting convex surfaces 6y is connected, for example, perpendicularly to another convex surface 6p.

[0218] 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.

[0219] According to the eleventh example of the related technology, since the connecting convex surfaces 6q, 6x, and 6y are provided, the characteristic of the bellows in axial expansion and contraction can be suppressed, and a flexible tube 5 suitable for the bending part 2b and the tubular part 2c that require expansion and contraction resistance can be formed.

[0220] 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.

[0221] 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.

[0222] 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.

[0223] 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.

[0224] [The twelfth example of related technology]

[0225] Figure 16 This is a perspective view of the flexible tube 5, representing the twelfth example of the related art. In this twelfth example of the related art, the same reference numerals are used for the parts that are the same as those in the first to eleventh examples of the related art, and the descriptions are omitted as appropriate. In this twelfth example of the related art, the differences from the first to eleventh examples of the related art are mainly explained.

[0226] In this example, the flexible tube 5 has multiple 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 intervals.

[0227] 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.

[0228] 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.

[0229] 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°.

[0230] 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.

[0231] 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.

[0232] 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.

[0233] According to the twelfth example of the related technology, it achieves approximately the same effect as the eleventh example of the related technology 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.

[0234] [The thirteenth example of related technology]

[0235] Figure 17This is a perspective view of the flexible tube 5, representing the thirteenth example of the related art. In this thirteenth example, the parts that are the same as those in the first to twelfth examples of the related art are labeled with the same reference numerals, and the descriptions are appropriately omitted. In this thirteenth example of the related art, the differences from the first to twelfth examples of the related art are mainly explained.

[0236] In this example, the flexible tube 5 will connect the two convex surfaces 6, which are in a ring shape in the circumferential direction, at multiple points in the circumferential direction.

[0237] The flexible tube 5 has multiple convex surfaces 6p that are annular in the circumferential direction.

[0238] 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.

[0239] 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°.

[0240] 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.

[0241] 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.

[0242] 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.

[0243] According to the thirteenth example of the related technology, it achieves roughly the same effect as the twelfth example of the related technology mentioned above.

[0244] In addition, in the twelfth case of related technology Figure 16 The example shown illustrates a convex surface 6p connected to other convex surfaces 6p at two locations, one above and one below. Additionally, in the thirteenth example of the related art... Figure 17The 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.

[0245] [First Implementation Method]

[0246] Figures 18-22 This represents the first embodiment of the present invention. Figure 18 This is a cross-sectional view showing a structural example of the bending line 23 in the bending portion 2b of the first embodiment. Figure 19 This is a partial perspective view showing a structural example of the bending line 23 in the bending portion 2b of the first embodiment.

[0247] In addition, Figure 18 In the following figures, arrow P indicates the base direction of the endoscope 1 (the direction on the side of the operating part 3), and arrow D indicates the front direction (the direction on the side of the front part 2a).

[0248] In addition, Figure 18 In the following figures, the curved section (2b) and the tubular section (2c) are shown with their external components, such as the braided layer and outer skin, removed to clearly show their internal structures. The curved section 2b and the tubular section 2c are actually constructed with the braided layer and outer skin covering their outer surfaces.

[0249] In addition, inside the curved portion 2b and the tubular portion 2c, in addition to the curved line 23 inserted in the coil tube 25, there are also built-in structures such as air and water supply pipes and treatment device insertion channels. However, these built-in structures are not directly related to the present invention, so they are omitted from the illustration.

[0250] In the first embodiment, the same reference numerals are used for parts that are the same as those in the examples of the related technologies described above, and descriptions are omitted as appropriate. In the first embodiment, the differences from the examples of the related technologies are mainly described.

[0251] The curved portion 2b (first tube) extends along an axis (central axis O: reference) extending from the base end direction P side (first side) to the front end direction D side (second side). Figure 21 The curved portion 2b is formed by bending under the traction of the bending line 23 (line).

[0252] That is, the bending line 23 extends from the bending portion 2b into the tubular portion 2c, and the base end of the bending line 23 is connected to the cylinder inside the operating part 3 on the P side (first side). The cylinder inside the operating part 3 rotates in conjunction with the bending operation knob 3b.

[0253] When the bending operation knob 3b of the operation unit 3 is operated, the bending wire 23 disposed inside the insertion part 2 is pulled by the operation unit 3, and the bending part 2b bends. Furthermore, an endoscope having a bending part 2b capable of bending in four directions (up, down, left, and right) may have four bending wires, and an endoscope having a bending part 2b capable of bending in two directions (up and down) may have two bending wires. Hereinafter, the description will primarily focus on an endoscope 1 capable of bending in four directions.

[0254] The bending section 2b (first tube) includes multiple bending blocks 21 (multiple cylinders) and connecting mechanisms 21b such as hinges. The multiple bending blocks 21 constituting the bending section 2b are, for example, formed of metal. The multiple bending blocks 21 are arranged along the central axis O (axis).

[0255] The connecting mechanism 21b connects two adjacent bending blocks 21 of a plurality of bending blocks 21 in such a way that one bending block 21 (cylinder) can deflect relative to the other bending block 21 (cylinder). In this way, the plurality of bending blocks 21 can be oscillatingly connected by the connecting mechanism 21b.

[0256] exist Figure 18 , Figure 21 An example of a curved section 2b capable of bending in four directions (up, down, left, and right) is shown in the figure. It is provided with a connecting mechanism 21b for bending in the up and down direction and a connecting mechanism 21b for bending in the left and right direction.

[0257] The front end (the end on the second side) of the curved line 23 is fixed to the front end side of the curved portion 2b, for example, by means of the fixing portion 24f, which is fixed to the curved block 21a located at the front end (see reference). Figure 21 wait).

[0258] Within the bend 2b, wire receiving members 22 are fixed to several of the multiple bend blocks 21. The multiple wire receiving members 22 are arranged at appropriate intervals along the axial direction of the bend 2b. The wire receiving members 22 are, for example, ring-shaped (see reference). Figure 19 ), with curved lines 23 running through it.

[0259] The bending mechanism 20 includes a bending portion 2b (first tube), a tube 24 (first guide) described below, and a wire receiving member 22 (second guide), and also includes a bending wire 23 (wire). The tube 24 is, for example, formed to be more flexible than the wire receiving member 22.

[0260] As described above, the base end side of the bending line 23 is disposed within the operating section 3. Therefore, at least a portion of the bending mechanism 20 (excluding the portion of the bending line 23 disposed on the first side (base end direction P side) of the operating section 3 and the insertion section 2) is disposed on the second side (front end direction D side) of the insertion section 2.

[0261] The connecting mechanism 21b and the tube 24 (first guide) are formed separately. Therefore, the connecting mechanism 21b and the tube 24 can also be formed of different materials.

[0262] Figure 20 This is a diagram comparing the relationship between the curved line 23 inserted into the tube 24 and the wire receiving member 22 in the first embodiment and the conventional relationship between the curved line 23 and the wire receiving member 22. Figure 20 In the diagram, column A represents the structure of this embodiment, and column B represents the conventional structure.

[0263] like Figure 20 As shown, the curved wire 23 is, for example, made of stranded wire and has irregularities on its surface. Regarding the wire receiving member 22, to reduce the possibility of jamming due to the irregularities on the surface of the curved wire 23, as follows... Figure 20 As shown in column B, the line connector 22 is formed by rounding the corner 22r into an R shape.

[0264] Furthermore, there are types where the bending portion 2b has a maximum bending angle exceeding 180°. In such types, when the insertion portion 2 of the endoscope 1 is inserted into the patient's body, the bending portion 2b of the insertion portion 2 sometimes becomes a complex shape such as a ring.

[0265] When bending operations are performed to pull the bending line 23 when the bending part 2b has a complex shape, even if the corner 22r of the line receiving member 22 is R-shaped, friction and jamming will occur between the unevenness of the surface of the bending line 23 and the inner circumferential surface and corner 22r of the line receiving member 22, and the sliding resistance will increase.

[0266] As a result, the traction force of the bending line 23 is lost at the line support 22, and the operating force required to operate the bending operation knob 3b increases due to the sliding resistance, reducing operability. In addition, wear and scraping sometimes occur at the corner 22r of the line support 22.

[0267] Therefore, as Figure 18 , Figure 19 as well as Figure 20 As shown in column A, in the first embodiment, the curved wire 23 is inserted into the wire receiving member 22 while being inserted into the tube 24. The tube 24 is a first guide for holding the curved wire 23. The wire receiving member 22 is a second guide for holding the tube 24.

[0268] The tube 24 is formed from resins such as HDPE (High-Density Polyethylene) or PTFE (Polytetrafluoroethylene) into a cylindrical shape, with a surface that slides well and is not prone to wrinkling. Furthermore, the tube 24 is designed with a wall thickness that makes it difficult for wrinkles to form on the inner circumference when bent. The coefficient of friction between the bend line 23 and the tube 24 is less than the coefficient of friction between the bend line 23 and the wire connector 22.

[0269] Figure 21 This is a cross-sectional view of the structure of the tube 24 through which the bending line 23 is inserted in the curved section 2b, which represents the straight state in the first embodiment.

[0270] Pipe 24 along Figure 21 The central axis O shown is located at the bend 2b. The front end of the tube 24 is fixed to the bending block 21a together with the front end of the bending line 23 at the fixing part 24f. On the other hand, the base end of the tube 24 is not fixed. Therefore, with respect to axial movement (in the direction of the central axis O), the front end of the tube 24 is the fixed end, and the base end is the free end.

[0271] Figure 22 This is a cross-sectional view of the state of the tube 24 through which the bending line 23 is inserted in the bent portion 2b in the first embodiment, representing the state of maximum bending.

[0272] Along the central axis O, a tubular portion 2c (second tube) is provided at a position closer to the base end (P side in the base end direction) than the bent portion 2b. A coil tube 25 is arranged in the tubular portion 2c along the central axis O. The coil tube 25 is a third guide member arranged in the tubular portion 2c along the central axis O. The coil tube 25 is fixed to a joining member (not shown) that joins the bent portion 2b and the tubular portion 2c.

[0273] The tube 24, which is fixed at the front end by the fixing part 24f, is inserted into multiple wire receiving parts 22. After being further inserted into the wire receiving part 22 at the base end, it enters and is placed in the middle of the coil tube 25 when it reaches the tubular part 2c. Figure 21 The following situation is shown: when the tube 24 is set such that the length of the tube 24 entering the coil tube 25 is a first predetermined length D3 when the bend 2b is in a straight state.

[0274] When the tube 24 is pulled along the bending line 23, the front end, which is the fixed end, does not move axially, while the base end, which is the free end, moves axially. For example, the base end of the tube 24, which is the outer peripheral side when bending, moves toward the front end side (towards the front end direction D), and the base end of the tube 24, which is the inner peripheral side when bending, moves toward the base end side (towards the base end direction P).

[0275] exist Figure 22The diagram shows that when the bend 2b is in its maximum bend state, the length of the tube 24 extending towards the front end into the coil tube 25 is the second predetermined length D2.

[0276] In specific products, the second specified length D2 can be set to, for example, 1 mm or more and 20 mm or less. Alternatively, the second specified length D2 can also be set to, for example, 10 mm or more. However, the second specified length D2 is not limited to these values.

[0277] The first specified length D3 is set to the length at which the base end of the tube 24 (applies to all tubes 24, but especially to the outer periphery of the tube 24 when it is bent) will not detach from the front end of the coil tube 25 (and will not be pulled out) even when the bend 2b is bent to its maximum extent (ensuring the length of the second specified length D2).

[0278] Here, consider the case where four bending lines 23 are provided for bending towards R (right), L (left), U (up), and D (down).

[0279] When the bending line 23 for bending R (right) is pulled to the maximum extent, the bending part 2b becomes the maximum bending state in the R (right) direction. At this time, the tube 24 that inserts the bending line 23 for bending L (left) extends to the maximum at the front end.

[0280] When the bending line 23 for bending L (left) is pulled to the maximum extent, the bending part 2b becomes the maximum bending state in the L (left) direction. At this time, the tube 24 that inserts the bending line 23 for bending R (right) extends to the maximum at the front end.

[0281] When the bending line 23 for bending U (upper) is pulled to the maximum extent, the bending part 2b becomes the maximum bending state in the direction of U (upper). At this time, the tube 24 that inserts the bending line 23 for bending D (lower) extends to the maximum at the front end.

[0282] When the bending line 23 for bending D (downward) is pulled to the maximum extent, the bending part 2b becomes the maximum bending state in the direction of D (downward). At this time, the tube 24 that inserts the bending line 23 for bending U (upward) extends to the maximum at the front end.

[0283] The first specified length D3 is based on the radial length R from the central axis O of the bend 2b to the center of the wire connector 22 (refer to...). Figure 21 ), the length L in the direction of the central axis O of the curved part 2b (refer to Figure 21 ), and the bending angle θmax when the bending part 2b is bent at its maximum (refer to Figure 22 To set it.

[0284] The bending angle θmax at the maximum bending of the bend 2b sometimes varies depending on which of the bending directions is R (right), L (left), U (up), or D (down). Therefore, even if the second specified length D2 of R (right), L (left), U (up), or D (down) at the maximum bending is set to be the same, the first specified length D3 may sometimes be different depending on which of the bending lines 23 of R (right), L (left), U (up), or D (down) the tube 24 is internally inserted into.

[0285] According to the first embodiment, with the curved wire 23 inserted into a smoothly sliding tube 24 on its surface, the tube 24 with the curved wire 23 inserted is inserted into the wire receiving member 22, thus forming a bending mechanism 20. Therefore, the curved wire 23 does not directly contact the wire receiving member 22, and no friction or jamming occurs between the unevenness of the surface of the curved wire 23 and the inner circumferential surface and corner 22r of the wire receiving member 22.

[0286] Furthermore, the coefficient of friction between the curved line 23 and the pipe 24 is less than that between the curved line 23 and the wire connector 22. Therefore, the loss of traction force on the curved line 23 caused by the wire connector 22 can be reduced. In addition, wear and scraping at the corner 22r of the wire connector 22 can be reduced.

[0287] Furthermore, the sliding resistance of the curved line 23 can be reduced without the use of powdered lubricant. Since powdered lubricant is not used, the endoscope 1 can be manufactured in managed areas such as cleanrooms. Therefore, manufacturing freedom is increased, manufacturing costs are reduced, and the construction of assembly lines is simplified.

[0288] Furthermore, since no powdered lubricant is used, the structure of this embodiment can also be applied even when endoscope 1 is a disposable endoscope that is not watertight. Therefore, for a portion of endoscope 1, the watertight seal design can be omitted, allowing for a more cost-effective endoscope design.

[0289] Alternatively, a structure could be considered that reduces the loss of traction force due to friction by applying a resin coating to the surface of the bent wire 23, which is composed of stranded wire. However, even with a resin coating, it is difficult to make the surface shape of the bent wire 23 completely smooth. In contrast, according to this embodiment, a tube 24 with a completely smooth surface shape can be used. Therefore, the sliding resistance generated between the tube 24 and the wire receiving member 22 in this embodiment is smaller than the sliding resistance generated between the bent wire 23 with the resin coating and the wire receiving member 22.

[0290] In this way, a low-cost bending mechanism 20 and an endoscope 1 having the bending mechanism 20 can be provided, which can be easily bent with less operating force.

[0291] Furthermore, according to the first embodiment, even when the bent portion 2b is bent to its maximum extent, the tube 24 will not detach from the coil tube 25, thus preventing interference between the front end of the coil tube 25 and the base end of the tube 24. Additionally, it prevents the base end of the tube 24 from becoming stuck on the inner diameter wall of the coil tube 25.

[0292] Furthermore, the tube 24 is only disposed on the front end side within the tubular portion 2c, rather than being disposed along the entire length of the tubular portion 2c. Therefore, when the tubular portion 2c flexes and changes shape, the amount of movement of the base end of the tube 24, which is the free end, in the direction of the central axis O can be reduced.

[0293] Generally, the total length of the tubular portion 2c is close to the total length of the insertion portion 2, while the total length of the bent portion 2b is significantly shorter than the total length of the tubular portion 2c. Therefore, in the structure of this embodiment, the total length of the tube 24 is significantly shorter than the total length of the insertion portion 2. Thus, compared to the structure in which the tube 24 is disposed on the side of the operation portion 3 (refer to the sixth embodiment described later), the sliding resistance between the bent line 23 and the tube 24 can be reduced, as can the sliding resistance between the tube 24 and the coil tube 25.

[0294] [Second Implementation]

[0295] Figures 23-25 This represents the second embodiment of the present invention. Figure 23 This is a cross-sectional view of the structure of the tube 24 through which the bending line 23 is inserted in the curved section 2b, which represents the straight state in the second embodiment. Figure 24 This is a cross-sectional view of the state of the tube 24 through which the bending line 23 is inserted in the bent portion 2b in the second embodiment, representing the state of maximum bending.

[0296] In the second embodiment, the same reference numerals are used for parts that are the same as those in the first embodiment and related technologies described above, and descriptions are omitted as appropriate. The second embodiment mainly describes the differences from the first embodiment and related technologies.

[0297] The front end (the end on the second side) of the bending line 23 is fixed to the front end side of the bending portion 2b, for example, by means of the fixing portion 24h, which is fixed to the bending block 21a located at the front end. Unlike the fixing portion 24f in the first embodiment, the fixing portion 24h only fixes the front end of the bending line 23 and does not fix the tube 24.

[0298] Similar to the first embodiment, the wire receiving member 22 (second guide) is provided with a plurality of bending blocks 21a.

[0299] The tube 24 (first guide) in this embodiment has a plurality of segmented tubes 24s arranged intermittently along the central axis O. The number of segmented tubes 24s associated with a certain bending direction is the same as the number of wire connectors 22 associated with the same bending direction. Hereinafter, the number of segmented tubes 24s will be represented by the natural number n.

[0300] n wire connectors 22 secure the n segmented pipes 24s to the n fixing parts 24t respectively. That is, the number of fixing parts 24t associated with a certain bending direction is the same as the number of segmented pipes 24s associated with the same bending direction and the number of wire connectors 22.

[0301] Alternatively, the wire receiving element 22 can be individually fixed to a plurality of curved blocks 21 arranged along the central axis O (axis). Furthermore, the wire receiving element 22 can be fixed to the plurality of curved blocks 21 arranged along the central axis O (axis) at appropriate intervals. Specifically, the wire receiving element 22 can be fixed only to the even-numbered curved block 21 counting from the front end, or it can be fixed to the curved block 21 in a ratio of three to one, or it can be fixed in other configurations.

[0302] like Figure 24 As shown, when the bend 2b is in its maximum bending state, the total length of all the segmented pipes 24s arranged on a bending line 23 along the direction of the central axis O is shorter than the length of the bending line 23 on the inner circumferential side of the bend 2b.

[0303] Furthermore, regarding all the segmented tubes 24s arranged on a curved line 23, the length and arrangement interval of each segmented tube 24s are set such that when the curved portion 2b is in the maximum curved state, adjacent segmented tubes 24s do not interfere with each other (their positions along the direction of the central axis O do not overlap).

[0304] Furthermore, a sufficient gap is provided between the base end of the segmented tube 24s located at the basemost end and the front end of the coil tube 25. Therefore, the segmented tube 24s and the coil tube 25 will not interfere with each other regardless of the bending state.

[0305] According to the second embodiment, regarding a single bend 23, the total length of the n intermittently arranged segmented tubes 24s is shorter than the length of a single tube 24. Therefore, the total length of the portion where the bend 23 contacts the n segmented tubes 24s is also shorter than the length where the bend 23 contacts the single tube 24. By shortening the contact length, the sliding resistance between the bend 23 and the n segmented tubes 24s can be reduced. Therefore, the operating force can be further reduced, and operability improved.

[0306] Furthermore, each of the n segmented tubes 24s is fixed to one of the n wire receiving members 22 at one of the n fixed parts 24t. Therefore, the segmented tubes 24s will not move relative to the fixed wire receiving members 22, that is, no sliding resistance will be generated between the segmented tubes 24s and the wire receiving members 22.

[0307] Figure 25 This is a cross-sectional view parallel to the central axis O, showing a modified example of the segmented tube 24s constituting the discontinuous tube 24 in the second embodiment.

[0308] The segmented tubes 24s have internal insertion holes 24e for inserting into the bend line 23. In the second embodiment, a plurality of segmented tubes 24s are arranged on a single bend line 23. Therefore, if there are edges at the inlet and outlet of the insertion hole 24e, there are twice the number (2n) of the number (n) of the segmented tubes 24s arranged on a single bend line 23, and the number of edges is able to contact the bend line 23. The total number of these edges is n times the number (2) of the edges when only one tube 24 is arranged on a single bend line 23.

[0309] Therefore, by providing R-shaped portions 24r at the inlet and outlet of the through holes 24e in all the segmented tubes 24s, the edges are rounded, thereby reducing the sliding resistance.

[0310] According to a variation of the second embodiment, the sliding resistance between the bending line 23 and the n segmented tubes 24s can be further reduced, and the operating force can be further reduced to improve operability.

[0311] In addition, the structure of providing R-shaped portions 24r at the inlet and outlet of the through hole 24e can also be applied to the tube 24 in other embodiments.

[0312] [Third Implementation Method]

[0313] Figure 26 This is a cross-sectional view perpendicular to the central axis O, showing the structure of the tube 24 through which the curved line 23 is inserted, in the third embodiment of the present invention.

[0314] In the third embodiment, the same reference numerals are used for parts that are the same as those in the first and second embodiments and related technologies described above, and descriptions are omitted as appropriate. The third embodiment mainly describes the differences from the first and second embodiments and related technologies.

[0315] In this embodiment, the tube 24 is formed in a flattened manner, comprising a short axis r1 in the radial direction in a section perpendicular to the central axis O. The tube 24 further comprises a long axis r2 in a radial direction different from the short axis r1. Figure 26 In the diagram, the minor axis r1 and the major axis r2 are represented as the minor axis and major axis of the interior of the elliptical-shaped through hole 24e, respectively.

[0316] In the illustrated example, an elliptical cross-section of tube 24 perpendicular to the central axis O is shown, but it is not limited to this. Any cross-sectional shape with different radial lengths can be used.

[0317] As the bending angle increases, the deformation of tube 24 also increases accordingly. Therefore, it is assumed that the gap between the inner wall of tube 24 and the bending line 23 narrows, and the inner wall of tube 24 comes into contact with the bending line 23, thus increasing the sliding resistance.

[0318] In contrast, according to the third embodiment, by using a tube 24 with an irregular cross-section having a short axis r1 and a long axis r2, the bending line 23 is retracted towards the long axis r2 side inside the tube 24 during bending. Therefore, the sliding resistance when pulling the bending line 23 can be reduced, and the decrease in operability can be suppressed.

[0319] [Fourth Implementation Method]

[0320] Figure 27 This is a diagram illustrating a structural example in the fourth embodiment of the present invention where the wire receiving members 22A and 22A0 are integrally provided on the bending block 21. Figure 27 In this diagram, the first column shows an example of the wire receiver 22A according to this embodiment, and the second column shows an example of a general wire receiver 22A0 compared to this embodiment. Additionally, in... Figure 27 In the diagram, column A shows a partial side view of the line support components 22A and 22A0 from a direction perpendicular to the central axis O, while column B shows a partial perspective view of the line support components 22A and 22A0 from a frontal direction along the central axis O.

[0321] In the fourth embodiment, the same reference numerals are used for parts that are the same as those in the first to third embodiments and related technologies described above, and descriptions are omitted as appropriate. The fourth embodiment mainly describes the differences from the first to third embodiments and related technologies.

[0322] The wire connector may be separately installed from the bending block 21 (see below). Figure 36 And the case where it is integrally set with the bending block 21 (see below). Figure 37 This implementation method is equivalent to an integrated installation.

[0323] In this case, the bending block 21 constituting the bending portion 2b and the wire receiving parts 22A and 22A0 are formed of the same material.

[0324] The wire receiving part 22A0 shown in the second column is formed, for example, by cutting two slits in a circumferential portion of the cylinder constituting the bending block 21, and deforming the portion with the slits radially inward by, for example, stamping.

[0325] An insertion hole 22e is formed between the online receiving component 22A0 and the cylinder constituting the bending block 21 for the insertion of the bending line 23 held in the tube 24.

[0326] The wire receiving element 22A shown in the first column is formed in essentially the same way as the wire receiving element 22A0. That is, the wire receiving element 22A is formed, for example, by cutting two slits in a portion of the circumferential direction of the cylinder constituting the bending block 21, and deforming the portion with the slits radially inward, for example, by stamping.

[0327] On the other hand, unlike the wire receiving member 22A0, the wire receiving member 22A also has tongues 22a formed at the entrance and exit of the through hole 22e during the stamping process. On the other hand, at the entrance and exit of the through hole 22e, corners 22r that are rounded into an R shape are formed opposite to the tongues 22a.

[0328] According to the fourth embodiment, a tongue 22a is also formed when the wire connector 22A is formed by stamping. Therefore, during bending, even if the tube 24 moves forward or backward relative to the wire connector 22A along the central axis O, the resulting sliding resistance can be reduced. Therefore, the operating force required to operate the bending operation knob 3b is reduced, and operability is improved.

[0329] [Fifth Implementation]

[0330] Figure 28 This is a diagram showing the structure of the tube 24 through which the bending line 23 is inserted, according to the fifth embodiment of the present invention. In the fifth embodiment, the tube 24 is disposed only within the bending portion 2b.

[0331] In the fifth embodiment, the same reference numerals are used for parts that are the same as those in the first to fourth embodiments and related technologies, and descriptions are omitted as appropriate. The fifth embodiment mainly describes the differences from the first to fourth embodiments and related technologies.

[0332] The front end of the tube 24 is fixed to the bending block 21a together with the front end of the bending line 23 at the fixing part 24f. The tube 24 is inserted through a plurality of wire receiving members 22, and after being inserted further through the wire receiving member 22 at the base end, it terminates in the bending part 2b.

[0333] The curved line 23 extending from the tube 24 within the curved section 2b penetrates into the coil tube 25 when it reaches the tubular section 2c.

[0334] When the tube 24 is pulled by the bending line 23, the front end, which is the fixed end, does not move, while the base end, which is the free end, moves axially. For example, the base end of the tube 24, which is the inner circumferential side when bending, moves towards the base end side (the tubular portion 2c side). At this time, a predetermined interval D1 is provided between the base end of the tube 24 (the end on the first side (the P side in the base end direction)) and the front end of the coil tube 25 (the end on the second side (the D side in the front end direction)) to avoid the base end of the tube 24 contacting the front end of the coil tube 25.

[0335] Furthermore, the base end of the tube 24, which becomes the outer peripheral side when bent, moves towards the front end side (front end 2a side). The length of the tube 24 is adjusted so that even at this time, the base end of the tube 24 will not detach from the wire connector 22 on the basemost side.

[0336] That is, the length of tube 24 was adjusted considering both the case where tube 24 is on the inner circumference of the bend and the case where it is on the outer circumference. Specifically, the length of tube 24 was adjusted so that, when the insertion part 2 is in a straight state, the base end of tube 24 is located approximately midway between the wire receiving member 22 on the basemost side and the front end of coil tube 25. In this case, the length of tube 24 is slightly shorter than the total length of the bend 2b.

[0337] According to the fifth embodiment, similarly to the embodiments described above, sliding resistance can be reduced, operating force can be suppressed, and operability can be improved. Furthermore, interference between the base end of the tube 24 and the wire connector 22 and the coil tube 25 can be prevented.

[0338] [Sixth Implementation Method]

[0339] Figure 29 This is a diagram showing the structure of the tube 24 through which the curved line 23 is inserted, according to the sixth embodiment of the present invention. In the sixth embodiment, the tube 24 is disposed within the curved portion 2b and the tubular portion 2c.

[0340] In the sixth embodiment, the same reference numerals are used for parts that are the same as those in the first to fifth embodiments and related technologies described above, and descriptions are omitted as appropriate. The sixth embodiment mainly describes the differences from the first to fifth embodiments and related technologies.

[0341] The front end of tube 24 is fixed to bending block 21a together with the front end of bending line 23 at fixing part 24f. Tube 24 is inserted into bending part 2b and further into coil tube 25 of tubular part 2c. Although not shown in the figure, the base end of tube 24 extends from coil tube 25 at the base end side of tubular part 2c. The base end side of tube 24 can be moved into operation part 3.

[0342] According to the sixth embodiment, it achieves the same effect as the fifth embodiment.

[0343] In addition, the coil tube 25 has a spiral irregularity on its inner surface. Therefore, the bent wire 23, which is made of stranded wire, sometimes gets caught on the irregularity of the inner surface of the coil tube 25 during traction, increasing the sliding resistance.

[0344] In contrast, according to the sixth embodiment, the tube 24 is also disposed within the coil tube 25, thus suppressing the increase in sliding resistance within the coil tube 25 when bending the wire 23. This reduces the overall sliding resistance of the insertion portion 2, further reducing the operating force required to operate the bending operation knob 3b.

[0345] [Seventh Implementation Method]

[0346] Figure 30 This is a diagram showing the structure of the tube 24 through which the bending line 23 is inserted, according to the seventh embodiment of the present invention. In the seventh embodiment, a first tube 24A (first guide) and a second tube 24B (fourth guide) are provided as the tube 24, with the first tube 24A inserted into the bending portion 2b and the second tube 24B inserted into the tubular portion 2c.

[0347] In the seventh embodiment, the same reference numerals are used for parts that are the same as those in the first to sixth embodiments and related technologies described above, and descriptions are omitted as appropriate. The seventh embodiment mainly describes the differences from the first to sixth embodiments and related technologies.

[0348] First tube 24A and Figure 28 The tube 24 in the fifth embodiment shown is constructed similarly. That is, the front end of the first tube 24A is fixed to the bending block 21a together with the front end of the bending line 23 at the fixing part 24f. In addition, the length of the first tube 24A is adjusted so that when the insertion part 2 is in a straight state, the base end of the first tube 24A is located approximately at the midpoint between the wire receiving member 22 on the basemost side and the front end of the coil tube 25.

[0349] The end (front end) of the second tube 24B (fourth guide) on the D-side (second side) is fixed together with the front end of the coil tube 25 at the boundary between the bent portion 2b (first tube) and the tubular portion 2c (second tube). Furthermore, the second fixing portion 24f' does not fix the bent line 23.

[0350] The second tube 24B is inserted into the coil tube 25, and is referenced. Figure 29 Similarly, in the sixth embodiment described above, the tube 24 can extend from the coil tube 25 at the base end of the tubular portion 2c. Therefore, the base end of the second tube 24B can be moved into the operation portion 3.

[0351] Between the base end of the first tube 24A and the second fixing part 24f′ to which the front end of the coil tube 25 is fixed, and Figure 28The example shown also has a specified interval D1.

[0352] According to the seventh embodiment, it achieves the same effect as the sixth embodiment.

[0353] Furthermore, according to the seventh embodiment, the first tube 24A is disposed within the bend 2b, and the second tube 24B is disposed within the tubular portion 2c. Therefore, the effect of the first tube 24A's movement due to the bending of the bend 2b can be absorbed within the bend 2b, and the effect of the second tube 24B's movement due to the deflection of the tubular portion 2c can be absorbed within the tubular portion 2c. Therefore, compared to the tube 24 in the sixth embodiment, the length of movement of both the first tube 24A and the second tube 24B can be suppressed.

[0354] Therefore, the sliding resistance generated when the first tube 24A and the second tube 24B respectively come into contact with the insert 2 is smaller than the sliding resistance generated when one tube 24 comes into contact with the insert in the sixth embodiment.

[0355] [Eighth Implementation Method]

[0356] Figure 31 This is a diagram showing the tube 24 when the bent portion 2b is bent, according to the eighth embodiment of the present invention.

[0357] In the eighth embodiment, the same reference numerals are used for parts that are the same as those in the first to seventh embodiments and related technologies, and descriptions are omitted as appropriate. The eighth embodiment mainly describes the differences from the first to seventh embodiments and related technologies.

[0358] When the bend 2b bends, the tube 24 inserted into the wire receiving member 22 bends in accordance with the bend shape of the bend 2b. At this time, the outer circumference of the bend in the tube 24 elongates, while the inner circumference contracts.

[0359] As described above, the tube 24 is formed of a material that is difficult to wrinkle even when shrinking, and its wall thickness is set to be wrinkle-resistant. However, when the bending radius is small, the shrinkage cannot be absorbed by the elastic deformation of the material alone, and wrinkles sometimes occur on the inner circumference of the bent tube 24. When the tube 24 wrinkles, jamming occurs at the corner 22r of the online connector 22.

[0360] Figure 32 This is a perspective view of a first structural example of tube 24C in the eighth embodiment. Figure 33 This is a diagram showing the cross-section and a partially enlarged side view of the tube 24C in the first structural example, as shown in the eighth embodiment. Figure 33 In the diagram, column A represents the cross-section of tube 24C, and column B represents a magnified partial side view of tube 24C.

[0361] Tube 24C has one or more grooves on its outer surface to prevent wrinkling when bent. Figure 32 as well as Figure 33 In the example shown, one or more grooves 24g1 are provided on the outer surface of the tube 24C, or multiple grooves in the example shown, which are parallel to the direction of the central axis of the tube 24C (i.e., at an angle of 0° to the axial direction).

[0362] Here, when tube 24C is positioned within the bend 2b, the direction of the central axis of tube 24C is parallel to the direction of the central axis O. Furthermore, the cross-sectional shape, depth, and number of grooves 24g1 are not limited to... Figure 32 and Figure 33 The structure shown.

[0363] Figure 34 This is a perspective view of a second structural example of tube 24D in the eighth embodiment. Figure 35 This is a diagram showing the cross-section and a partially enlarged side view of the tube 24D in the second structural example, as shown in the eighth embodiment. Figure 35 In the diagram, column A represents the cross-section of tube 24D, and column B represents a magnified partial side view of tube 24D.

[0364] Tube 24D has one or more grooves on its outer surface to prevent wrinkling when bent. Figure 34 and Figure 35 In the example shown, one or more spiral grooves 24g2, which in the illustrated example are multiple, are provided on the outer surface of the tube 24D at an angle δ relative to the central axis of the tube 24D. δ is, for example, an angle in the range of 0° < δ ≤ 30°.

[0365] Here, when tube 24D is positioned within the bend 2b, the direction of the central axis of tube 24D is parallel to the direction of the central axis O. Furthermore, the cross-sectional shape, depth, and number of grooves 24g2 are not limited to... Figure 34 and Figure 35 The structure shown.

[0366] Combining the structural examples of tubes 24C and 24D, it is sufficient that the groove provided on the outer surface (outer circumferential surface) of tube 24 forms an angle of more than 0° and less than 30° (or less than about 30°) relative to the direction of the axis (central axis O).

[0367] According to the eighth embodiment, since... Figures 32-35 The grooves 24g1 and 24g2 shown are provided on the outer surface of the tube 24, thus enabling the formation of a structure on the outer surface of the tube 24 that is difficult to wrinkle.

[0368] Furthermore, since the angles of the grooves 24g1 and 24g2 relative to the axis (central axis O) are set to 0° or more and 30° or less (or about 30° or less), the tube 24 becomes a tube that will not impair its sliding properties relative to the line connector 22.

[0369] [Ninth Implementation Method]

[0370] Figure 36 This is a partial perspective view showing the structure of the wire support member 22B in the bending block 21 according to the ninth embodiment of the present invention.

[0371] In the ninth embodiment, the same reference numerals are used for parts that are the same as those in the first to eighth embodiments and related technologies described above, and descriptions are omitted as appropriate. The ninth embodiment mainly describes the differences from the first to eighth embodiments and related technologies.

[0372] The bending block 21 has a hinge mounting hole 21b and a wire receiving mounting hole 21c. By mounting a hinge in the hinge mounting hole 21b, two adjacent bending blocks 21 can be connected to each other by deflection.

[0373] A wire receiving element 22B, which is separately formed from the cylindrical body constituting the bending block 21, is installed in the wire receiving mounting hole 21c. The wire receiving element 22B contains an insertion hole 22e for inserting and receiving a tube 24 for the bent wire 23. Alternatively, a structure can be adopted in which the wire receiving element 22B, manufactured as a separate component, is installed on the bending block 21.

[0374] Furthermore, the bending block 21 and the wire receiving member 22B constituting the bending portion 2b can be formed of the same material or different materials.

[0375] According to the ninth embodiment, by using the wire receiver 22B, which is a component other than the main body of the bending block 21, the wire receiver 22B can be manufactured with stable quality and low cost. Therefore, the bending mechanism 20 including the bending block 21 becomes a structure suitable for disposable endoscopes requiring low cost.

[0376] Figure 37 This is a partial perspective view showing the structure of the wire support member 22A0 in the bent block 21 of the modified example of the ninth embodiment.

[0377] For reference Figure 27 As explained in the second column, the wire connector 22A0 can also be integrated with the cylinder that forms the bending block 21.

[0378] That is, such as Figure 37As shown, the wire receiving member 22A0 is formed, for example, by cutting two slits in a portion of the circumferential direction of the cylinder constituting the bending block 21, and deforming the portion formed by the slits radially inward, for example, by stamping. In this case, the wire receiving member 22A0 is formed of the same material as the bending block 21.

[0379] The wire receiving part 22A0 contains a through hole 22e for inserting a tube 24 for receiving a bent wire 23.

[0380] According to a variation of the ninth embodiment, the wire receiving member 22A0 can be integrally formed with the bending block 21 by stamping or the like, thus enabling the bending block 21 to be produced at a low cost. Therefore, the bending mechanism 20 including the bending block 21 becomes a structure suitable for disposable endoscopes requiring low cost.

[0381] [Additional Notes]

[0382] Based on the above description in relation to embodiments of the present invention, the following structure can be obtained.

[0383] [Postscript A1]

[0384] 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 is disposed on the outer peripheral surface and is 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.

[0385] [Note A2]

[0386] In the endoscope described in Appendix A1, the plurality of convex surfaces each have the same shape.

[0387] [Note A3]

[0388] In the endoscope described in Appendix A2 When the outer peripheral surface is unfolded into a plane, the plurality of convex surfaces are each polygonal.

[0389] [Notes A4]

[0390] In the endoscope described in Appendix A2 When the outer peripheral surface is unfolded into a plane, the plurality of convex surfaces are respectively rounded polygons.

[0391] [Note A5]

[0392] In the endoscope described in Appendix A3 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.

[0393] [Note A6]

[0394] In the endoscope described in Appendix A3 When the outer peripheral surface is unfolded into a plane, the plurality of convex surfaces are each quadrilateral.

[0395] [Note A7]

[0396] In the endoscope described in Appendix A6 When the outer peripheral surface is unfolded into a plane, the plurality of convex surfaces are respectively rhomboid in shape.

[0397] [Note A8]

[0398] In the endoscope described in Appendix A6 When the outer peripheral surface is unfolded into a plane, the plurality of convex surfaces are each rectangular.

[0399] [Note A9]

[0400] In the endoscope described in Appendix A2 When the outer peripheral surface is unfolded into a plane, the plurality of convex surfaces are respectively T-shaped.

[0401] [Note A10]

[0402] In the endoscope described in Appendix A2 When the outer peripheral surface is unfolded into a plane, the plurality of convex surfaces are respectively L-shaped.

[0403] [Postscript A11]

[0404] In the endoscope described in Appendix A3 When the outer peripheral surface is unfolded into a plane, the plurality of convex surfaces are each triangular.

[0405] [Note A12]

[0406] In the endoscope described in Appendix A2 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.

[0407] [Note A13]

[0408] In the endoscope described in Appendix A12 The filling ratio of the filling material in the filling structure portion varies along the axial direction.

[0409] [Note A14]

[0410] In the endoscope described in Appendix A2 The radial distances from the concave surface to the plurality of convex surfaces, centered on the central axis, are all different.

[0411] [Note A15]

[0412] In the endoscope described in Appendix A1, The endoscope has an insertion part for inserting into the subject. The flexible tube is disposed at the insertion part.

[0413] [Note A16]

[0414] In the endoscope described in Appendix A1 The plurality of convex surfaces are arranged periodically along the outer peripheral surface.

[0415] [Note A17]

[0416] In the endoscope described in Appendix A1 The plurality of convex surfaces are arranged non-periodically along the outer peripheral surface.

[0417] [Postscript A18]

[0418] In the endoscope described in Appendix A1 The concave surface includes at least one of the first portion and the second portion.

[0419] [Note A19]

[0420] In the endoscope described in Appendix A1 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.

[0421] [Note A20]

[0422] 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 entirely inclined relative to the axial direction parallel to the central axis and also inclined relative to the circumferential direction about the central axis.

[0423] [Postscript B1]

[0424] 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 entirely inclined relative to the axial direction parallel to the central axis and also inclined relative to the circumferential direction about the central axis.

[0425] [Note B2]

[0426] In the endoscope described in Appendix B1 When the outer peripheral surface is unfolded into a plane, the plurality of convex surfaces are each quadrilateral.

[0427] [Note B3]

[0428] In the endoscope described in Appendix B1 When the outer peripheral surface is unfolded into a plane, the plurality of convex surfaces are respectively rhomboid in shape.

[0429] [Postscript B4]

[0430] In the endoscope described in Appendix B1 When the outer peripheral surface is unfolded into a plane, the plurality of convex surfaces are each rectangular.

[0431] [Postscript B5]

[0432] A 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; A concave surface is disposed on the outer peripheral surface and is 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.

[0433] 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.

[0434] 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. A bending mechanism, characterized in that, have: The first tube is formed along an axis extending from the first side to the second side and is configured to be bent by the pull of a line; A first guide member, formed of resin into a cylindrical shape, is disposed along the axis of the first tube to hold the line; and The second guide is fixed to the first tube, thus holding the first guide in place.

2. The bending mechanism according to claim 1, characterized in that, The first tube has: Multiple cylinders arranged along the axis; and A connecting mechanism that connects two adjacent cylinders of the plurality of cylinders in a manner in which one cylinder can deflect relative to the other. The connecting mechanism is formed separately from the first guide.

3. The bending mechanism according to claim 1, characterized in that, The resin is HDPE, i.e., high-density polyethylene, or PTFE, i.e., polytetrafluoroethylene.

4. The bending mechanism according to claim 1, characterized in that, The bending mechanism also includes the line. The line passes through the first guide member. The end of the line on the second side is fixed to the second side of the first tube. The coefficient of friction between the line and the first guide is less than the coefficient of friction between the line and the second guide.

5. The bending mechanism according to claim 1, characterized in that, The first guide has a groove on its outer peripheral surface at an angle of less than 30° relative to the axis.

6. The bending mechanism according to claim 1, characterized in that, The bending mechanism also includes: A second tube, which is disposed along the axis at a position closer to the first side than the first tube; and A third guide member is disposed along the axis of the second tube. The first guide enters from the first tube and is positioned midway into the third guide. When the first tube is in a straight state, the length of the first guide entering the third guide is set to a first predetermined length.

7. The bending mechanism according to claim 6, characterized in that, Based on the radial length from the central axis of the first tube to the center of the second guide, the length of the first tube in the direction of the axis, and the bending angle of the first tube at its maximum bending, the first predetermined length is set to a length that the first guide will not detach from the third guide even when the first tube is at its maximum bending.

8. The bending mechanism according to claim 6, characterized in that, When the first tube is in its most bent state, the second specified length of the first guide entering the third guide is set to be more than 1 mm and less than 20 mm.

9. The bending mechanism according to claim 6, characterized in that, When the first tube is in its most bent state, the second predetermined length of the first guide entering the third guide is set to be 10 mm or more.

10. The bending mechanism according to claim 1, characterized in that, The first guide includes a plurality of segmented guides discontinuously arranged along the axis. The second guide is provided in multiple forms, and the multiple second guides respectively fix the multiple segmented guides.

11. The bending mechanism according to claim 10, characterized in that, The first tube has: Multiple cylinders arranged along the axis; and A connecting mechanism that connects two adjacent cylinders of the plurality of cylinders in a manner in which one cylinder can deflect relative to the other. The plurality of second guides are respectively fixed to the plurality of cylinders.

12. The bending mechanism according to claim 1, characterized in that, The first guide is formed in a flat manner, in a cross section perpendicular to the axis, to include a short axis in the radial direction.

13. The bending mechanism according to claim 1, characterized in that, The first tube and the second guide are made of the same material.

14. The bending mechanism according to claim 1, characterized in that, The bending mechanism also includes: A second tube, which is disposed along the axis at a position closer to the first side than the first tube; and A third guide member is disposed along the axis of the second tube. The first side end of the first guide is configured to have a predetermined interval between it and the second side end of the third guide.

15. The bending mechanism according to claim 14, characterized in that, The bending mechanism also includes a fourth guide that passes through the third guide, and the end on the second side is fixed to the boundary between the first tube and the second tube.

16. The bending mechanism according to claim 1, characterized in that, The first tube is made of metal.

17. The bending mechanism according to claim 1, characterized in that, The first guide is formed to be softer than the second guide.

18. An endoscope, characterized in that, have: An insertion part, configured to be inserted into the subject; The operating part is located at a position closer to the first side than the insertion part; and A bending mechanism, at least a portion of which is disposed on the second side of the insertion portion, The bending mechanism includes: The first tube is formed along an axis extending from the first side to the second side and is configured to be bent by the pull of a line; A first guide member, formed of resin into a cylindrical shape, is disposed along the axis of the first tube to hold the line; and The second guide member is fixed to the first tube, thus retaining the first guide member. The first side of the line is connected to the operating part.

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