Guide head and guide tube

Abstract

To provide a guide head that can guide a leading end so that it can appropriately get over a step inside a narrow space.SOLUTION: A guide head 22 has a first guide surface 35 that is formed on an outer surface of a head body 30 in an area including a terminal (front end) in the direction of a central axis O' of the head body 30, and surrounds a through hole 32; and irregularities that are formed on the first guide surface 35 by a plurality of grooves 36. The irregularities on the first guide surface 35 extend in directions radiating from the through hole 32 in the area including the terminal (front end) of the head body 30.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a guide head and a guide tube for guiding the insertion of an insertion portion of an endoscope into a narrow space such as a pipe. [Background technology]

[0002] Conventionally, endoscopes have been widely used in the industrial field. This type of industrial endoscope can be suitably used for inspecting the inside of various narrow spaces, such as pipelines in chemical plants.

[0003] For example, industrial endoscopes are suitable for use in narrow conduit-like spaces where a straight pipe and a bent pipe are connected, and narrow conduit-like spaces generally have a step at the connection between the straight pipe and the bent pipe.

[0004] A known guide head (insertion aid) for assisting smooth movement of an insertion section through such narrow spaces is disclosed in Patent Document 1, for example. The guide head of Patent Document 1 is attached to the distal end of the insertion section. This guide head has a distal tapered surface whose outer diameter decreases from the proximal end to the distal end, and a proximal tapered surface having a truncated cone shape whose outer diameter decreases from the distal end to the proximal end. For example, when the insertion section is inserted into a narrow space, the distal tapered surface abuts against a step in the narrow space in a slidable manner. As a result, the distal tapered surface guides the distal section in a direction that overcomes the step. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] US 2023 / 0011117 A1 Summary of the Invention [Problem to be solved by the invention]

[0006] However, the tapered surface of the guide head does not always slide in a direction that moves the tip end away from the step. That is, depending on the state of contact with the step, the tapered surface may slide in a direction different from the direction that moves over the step. In such cases, it may be difficult for the tip end to move over the step, and it may be difficult to achieve smooth movement of the insertion section.

[0007] An object of the present invention is to provide a guide head and a guide tube that can guide the tip portion so as to accurately overcome steps inside a narrow space. [Means for solving the problem]

[0008] A guide head according to one aspect of the present invention comprises a head body, a through hole that penetrates the head body along the central axis direction of the head body and through which an insertion portion of an endoscope can be inserted, a guide surface that is formed on the outer surface of the head body in a region that includes the end terminal of the head body in the central axis direction and surrounds the through hole, and irregularities formed on the guide surface, wherein the irregularities extend in a direction radial from the through hole in the region that includes the end terminal of the head body.

[0009] A guide tube according to one aspect of the present invention comprises a tube body through which an insertion portion of an endoscope can be inserted, and a guide head arranged at the tip side of the tube body, wherein the guide head comprises a head body, a through hole that penetrates the head body along the central axis direction of the head body and through which the insertion portion can be inserted, a guide surface formed on the outer surface of the head body in a region that includes an end terminal of the head body in the central axis direction and surrounding the through hole, and irregularities formed on the guide surface, wherein the irregularities extend in a direction radial from the through hole in a region that includes the end terminal of the head body. [Effects of the Invention]

[0010] According to the present invention, the tip portion can be guided so as to accurately overcome steps inside a narrow space. [Brief explanation of the drawings]

[0011] [Figure 1] FIG. 1 is a diagram showing the configuration of an endoscope device equipped with a guide tube according to a first embodiment. [Figure 2] FIG. 1 is a perspective view showing a guide tube and an insertion section according to a first embodiment; [Figure 3] FIG. 1 is a side view showing a guide tube according to the first embodiment; [Figure 4] FIG. 1 is a side view (part 1) illustrating the guide tube when passing through a narrow space in a curved tubular shape having a step according to the first embodiment. [Figure 5] FIG. 2 is a side view (part 2) illustrating the guide tube when passing through a narrow space in a curved tubular shape having a step according to the first embodiment. [Figure 6] FIG. 10 is a perspective view showing the guide tube from the distal end side when passing through a narrow space in a bent tubular shape according to the first embodiment; [Figure 7] FIG. 10 is a perspective view showing a guide tube according to a first modified example of the first embodiment; [Figure 8] FIG. 10 is a side view showing a guide tube according to a first modified example of the first embodiment; [Figure 9] FIG. 10 is a side view showing a guide tube according to a second modified example of the first embodiment; [Figure 10] FIG. 10 is a perspective view showing a guide tube according to a third modified example of the first embodiment; [Figure 11] FIG. 10 is a perspective view showing a partially exploded guide tube according to a fourth modified example of the first embodiment; [Figure 12] FIG. 10 is a side view showing a part of the guide tube cut away in the central axis direction according to a fourth modified example of the first embodiment; [Figure 13] FIG. 10 is a perspective view showing a guide tube according to a fifth modified example of the first embodiment; [Figure 14] FIG. 10 is a perspective view showing a guide tube according to a sixth modified example of the first embodiment; [Figure 15] FIG. 10 is a perspective view showing a guide tube and an insertion section according to a second embodiment. [Figure 16]FIG. 10 is a cross-sectional view showing a guide tube attached to an insertion section according to a second embodiment. [Figure 17] FIG. 10 is a cross-sectional view showing the guide tube before it is attached to the insertion section according to the second embodiment. [Figure 18] FIG. 10 is an exploded perspective view showing a guide tube and an insertion section according to a third embodiment. [Figure 19] FIG. 10 is a cross-sectional view showing a guide tube according to a third embodiment. [Figure 20] FIG. 10 is a cross-sectional view showing the guide tube before assembly according to the third embodiment. [Figure 21] FIG. 10 is an exploded perspective view showing a guide tube and an insertion section according to a fourth embodiment. [Figure 22] FIG. 10 is a perspective view showing a state in which the tube body is detached from the guide head attached to the insertion section in the fourth embodiment. [Figure 23] FIG. 10 is a perspective view showing a state in which the tube body is connected to the guide head attached to the insertion section according to the fourth embodiment. [Figure 24] FIG. 10 is a perspective view showing a guide tube according to a fifth embodiment. [Figure 25] FIG. 10 is an exploded perspective view showing a guide tube according to a fifth embodiment. [Figure 26] FIG. 10 is a perspective view showing the guide tube when passing through a narrow space in a bent tubular shape according to the fifth embodiment. [Figure 27] FIG. 13 is a perspective view showing a guide tube according to a first modified example of the fifth embodiment. [Figure 28] FIG. 13 is a perspective view showing a guide tube according to a second modified example of the fifth embodiment. [Figure 29] FIG. 13 is a side view showing the guide tube when passing through a narrow space in a bent tubular shape according to a second modification of the fifth embodiment. [Figure 30] FIG. 13 is a perspective view showing a guide tube according to a third modified example of the fifth embodiment. [Figure 31] FIG. 13 is a side view showing the guide tube when passing through a narrow space in a bent tubular shape according to a third modified example of the fifth embodiment. [Figure 32]FIG. 13 is a side view showing the guide tube when passing through a narrow space in a bent tubular shape according to a third modified example of the fifth embodiment. [Figure 33] FIG. 13 is a perspective view showing a guide tube according to a fourth modified example of the fifth embodiment. [Figure 34] FIG. 13 is a perspective view showing a guide tube according to a fifth modified example of the fifth embodiment. [Figure 35] FIG. 10 is a side view showing the guide tube when passing through a narrow space in a bent tubular shape according to a fifth modified example of the fifth embodiment. [Figure 36] FIG. 13 is an exploded perspective view showing a guide tube according to a sixth embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0012] A first embodiment of the present technology will be described below with reference to Figs. 1 to 5. The endoscope device 1 shown in Fig. 1 is an industrial endoscope device. This endoscope device 1 is suitably used for inspecting the inside of a subject having a narrow space, such as a pipeline in a chemical plant. The endoscope device 1 is configured to include an endoscope 2 and a device main body 3.

[0013] The endoscope 2 includes an insertion section 5, an operation section 6, and a universal cord .

[0014] The insertion section 5 has an elongated shape that can be inserted into a subject such as a duct, etc. The insertion section has a tip section 11, a bending section 12, and a flexible section 13 in this order from the tip side.

[0015] For example, as shown in FIG. 2, the tip portion 11 has an observation window 11a and an illumination window 11b on its tip surface. The observation window 11a is configured by an observation optical system of an imaging unit 11c built into the tip portion 11. The imaging unit 11c has an imaging element (not shown) such as a CMOS image sensor. The imaging element receives, for example, reflected light of illumination light irradiated onto the subject from the illumination window 11b. This enables the imaging unit 11c to capture an image of the subject.

[0016] The bending portion 12 is connected to the base end of the distal end portion 11. The bending portion 12 is configured to be bendable in, for example, the up, down, left, and right directions. In the following description, the up, down, left, and right directions of the distal end portion 11 and the bending portion 12 are defined based on the up, down, left, and right directions set in the imaging unit 11c (i.e., the up, down, left, and right directions of the image captured by the imaging unit 11c).

[0017] The flexible section 13 is connected to the base end of the bending section 12. The flexible section 13 is made of a long flexible tube.

[0018] 1, the operation unit 6 has a bending joystick 6a and a plurality of operation buttons 6b. The bending joystick 6a is tiltable relative to the operation unit 6. The bending joystick 6a bends the bending portion 12 in the up, down, left, and right directions in conjunction with a tilt operation by the user. Various functions are assigned to each operation button 6b, such as a freeze function for an image, a bend lock function for the bending portion 12, and an image recording command function.

[0019] The universal cord 7 extends from the operation unit 6. The extending end of the universal cord 7 is electrically connected to the device main body 3.

[0020] The device main body 3 has a control unit 14 and a display unit 15 .

[0021] The control unit 14 is configured by a well-known microcomputer or the like equipped with a CPU, RAM, ROM, non-volatile storage unit, etc. This control unit 14 has a function of generating an endoscopic image by processing an image signal transmitted from the imaging unit 11c of the endoscope 2. The control unit 14 also has a function of generating images of various operation menus, etc. All or part of the control unit 14 can also be configured by a logic circuit, an analog circuit, or an electronic circuit such as an FPGA.

[0022] The display unit 15 has a function of displaying various images such as an endoscopic image generated by the control unit 14. The display unit 15 may be provided with a touch panel. Such a touch panel allows, for example, an operation to enlarge or reduce the endoscopic image displayed on the display unit 15. Alternatively, the touch panel allows various input operations based on an operation menu image displayed on the display unit 15.

[0023] In such an endoscope device 1, a guide tube 20 can be attached to the insertion section 5 of the endoscope 2. As shown in FIGS. 2 and 3, the guide tube 20 has a tube body 21 and a guide head 22.

[0024] The tube body 21 includes, for example, a spiral tube 25 , a coil 26 , and a handle 27 .

[0025] The spiral tube 25 is, for example, bendable. Furthermore, the spiral tube 25 has a flexible structure that allows it to be bent by bending the endoscope 2. The inner diameter of the spiral tube 25 is set to be larger than the outer diameter of the insertion section 5. This allows the insertion section 5 to be inserted into the spiral tube 25.

[0026] The length of the spiral tube 25 is set to be longer than the combined length of the bending portion 12 and the distal end portion 11 of the insertion section 5. This allows the spiral tube 25 to cover the entire outer periphery of the bending portion 12.

[0027] The coil 26 is connected to the base end of the spiral tube 25. The coil 26 is formed, for example, by winding a wire having a circular or rectangular cross section into a coil shape. The coil 26 can be tightly wound throughout, or a portion of the distal end (approximately the same length as the spiral tube 25) can be loosely wound. The coil 26 has flexibility that allows it to be bent by an external force. However, the coil 26 has higher rigidity than the spiral tube 25 so that it normally remains straight. Here, when the distal end portion of the coil 26 is loosely wound, it is preferable that the flexibility of the loosely wound portion of the coil 26 be intermediate between the flexibility of the spiral tube 25 and the flexibility of the tightly wound portion of the coil 26. The inner diameter of the coil 26 is set to be approximately the same as the inner diameter of the spiral tube 25. This allows the insertion section 5 to be inserted through the coil 26.

[0028] Furthermore, the combined total length of the coil 26 and the helical tube 25 is set to be approximately equal to the length of the flexible section 13 of the insertion section 5. Alternatively, depending on the application, the combined total length of the coil 26 and the helical tube 25 may be set to be shorter than the flexible section 13. As a result, when the combined total length is set to be equal to that of the flexible section 13, the coil 26 can be used in a state in which it covers approximately the entire outer periphery of the flexible section 13. Furthermore, when the combined total length is set to be shorter than the flexible section 13, the endoscope 2 can be used with the endoscope 2 protruding from the tip of the guide tube 20. For example, when inspecting a curved pipe, the guide tube 20 can be inserted into the end of the curved pipe, and then the endoscope can be protruded from inside the guide tube 20.

[0029] The handle 27 is connected to the base end of the coil 26. The handle 27 has, for example, a ring shape.

[0030] The inner diameter of the handle 27 is set to be approximately the same as the inner diameter of the spiral tube 25 and the inner diameter of the coil 26. This allows the insertion section 5 to be inserted into the handle 27.

[0031] The outer diameter of the handle 27 is set to be larger than the outer diameter of the coil 26. This allows the user or the like to easily grip the outer periphery of the handle 27. The user or the like can then slide the gripped handle 27 in the direction of the central axis O (longitudinal direction) of the insertion section 5. This allows the user or the like to freely change the relative positions of the helical tube 25 and the coil 26, and the insertion section 5 in the longitudinal direction.

[0032] The guide head 22 has a head body 30. The basic shape of the head body 30 is a substantially cylindrical shape. That is, the head body 30 has a through hole 32. The through hole 32 penetrates the head body 30 along the central axis O' of the head body 30.

[0033] Here, the maximum outer diameter of the outer peripheral surface of the head body 30 is set to be larger than the outer diameter of the helical tube 25 and the outer diameter of the coil 26. In addition, the inner diameter of the through hole 32 is set to be approximately the same as the inner diameter of the tube body 21.

[0034] A joint 31 is provided at the base end of the head body 30. In this embodiment, the joint 31 is, for example, a ring-shaped protrusion. This joint 31 protrudes from the base end of the head body 30 in the direction of the central axis O'. For example, the joint 31 is fitted onto the inner periphery of the tip end of the tube body 21 and bonded thereto. As a result, the joint 31 connects the base end of the head body 30 to the tip end of the tube body 21. With this connection, the joint 31 positions the central axis O' of the through hole 32 coaxially with the central axis O of the tube body 21. As a result, the through hole 32 of the head body 30 communicates with the interior of the tube body 21. Furthermore, the outer peripheral surface of the head body 30 protrudes radially outward beyond the helical tube 25 and the coil 26.

[0035] A first guide surface 35 is formed on the outer surface of the tip side of the head body 30. The first guide surface 35 is configured by, for example, a tapered surface. This first guide surface 35 is formed in a region including the tip (end) of the head body 30. In this embodiment, the first guide surface 35 has a substantially truncated cone shape whose outer diameter increases from the tip of the head body 30 toward the base end.

[0036] A plurality of grooves 36 are formed as recesses in the first guide surface 35. Each groove 36 is formed in an area including the front end of the head body 30. Each groove 36 extends in a radial direction from the through hole 32.

[0037] In this embodiment, the grooves 36 are arranged at equal intervals in the circumferential direction of the through-hole 32 .

[0038] The width of each groove 36 narrows as it moves away from the through-hole 32. That is, each groove 36 has a substantially V-shape in plan view.

[0039] These grooves 36 form a plurality of irregularities on the first guide surface 35. Each of the irregularities extends in a direction radially from the through-hole 32.

[0040] A second guide surface 37 is formed on the outer surface of the base end side of the head main body 30. The second guide surface 37 is configured by, for example, a tapered surface. This second guide surface 37 is formed in a region including the base end (terminal end) of the head main body 30. In this embodiment, the second guide surface 37 has a generally truncated cone shape whose outer diameter increases from the base end of the head main body 30 toward the tip side.

[0041] A plurality of grooves 38 are formed as recesses in the second guide surface 37. Each groove 38 is formed in an area including the base end of the head body. Each groove 38 extends in a radial direction from the through hole 32.

[0042] In this embodiment, the grooves 38 are arranged at equal intervals in the circumferential direction of the through-hole 32 .

[0043] The groove width of each groove 38 narrows as it is positioned farther away from the through-hole 32. That is, each groove 38 has a substantially V-shape in plan view as viewed from the direction of the central axis O'.

[0044] These grooves 38 form a plurality of irregularities on the second guide surface 37. Each of the irregularities extends in a direction radially from the through hole 32.

[0045] The guide tube 20 configured in this manner assists the movement of the insertion section 5 within a narrow space.

[0046] For example, the guide tube 20 prevents the insertion portion 5 from being damaged by protrusions or the like present in the narrow space when the insertion portion 5 moves within the narrow space. Such protection of the insertion portion 5 is achieved by covering the outer periphery of the insertion portion 5 with the tube main body 21.

[0047] Furthermore, the guide tube 20 prevents the movement of the insertion portion 5 from being hindered by steps or the like present in the narrow space when the insertion portion 5 moves within the narrow space. Such assistance to the movement of the insertion portion 5 is realized mainly by the first guide surface 35 and the second guide surface 37 provided on the guide head 22.

[0048] For example, when the guide tube 20 with the insertion section 5 inserted therein is inserted into the duct 100, the first guide surface 35 guides the guide head 22 in a direction that avoids interference with the step 101 or the like.

[0049] That is, as shown in Fig. 4, when the first guide surface 35 is inclined relative to the surface 101a of the step 101 in the height direction, i.e., when the angle of contact between the first guide surface 35 and the surface 101a is large (when the central axis of the guide head 22 is inclined largely relative to the central axis of the piping 100 in the outlet direction), the helical tube 25 at the tip end of the guide tube 21 is less bent, and the repulsive force trying to return to a straight state is relatively small. When the guide head 22 comes into contact with the edge 101b of the step 101 and the pressing force is small, the first guide surface 35 abuts against the edge 101b of the step 101. Then, when the guide tube 20 is pushed into the pipeline 100, the first guide surface 35 slides against the edge 101b of the step 101, moving the guide head 22 in the height direction of the step 101 (see the two-dot chain line in Fig. 4). As a result, the first guide surface 35 guides the guide head 22 in a direction that avoids interference with the step 101 (that is, a direction that goes over the step 101).

[0050] In this case, each groove 36 located near the step 101 extends in the sliding direction of the first guide surface 35. Therefore, each groove 36 does not generate sliding resistance between the first guide surface 35 and the step 101.

[0051] Furthermore, as shown in FIG. 4 , the pushing force of the guide tube 21 does not necessarily cause the guide head 22 to slide against the step 101. For example, if the guide head 22 continues to be pushed without sliding, the helical tube 25 at the tip of the guide tube 21 will bend more significantly, as shown in FIGS. 5 and 6 . When the first guide surface 35 is substantially parallel to the height-direction surface 101a of the step 101, the first guide surface 35 will be in substantial surface contact with the height-direction surface 101a of the step 101. In such a case, it is difficult to move the guide head 22 while sliding the first guide surface 35 against the edge 101b of the step 101. In such a case, by rotating the guide tube 20 while pushing it into the conduit 100, one of the grooves 36 formed in the first guide surface 35 will catch on the edge 101b of the step 101 (see, for example, the area surrounded by the dashed line in FIG. 6 ). The guide head 22 then further rotates around the catch portion. This rotation of the guide head 22 is centered around a portion eccentric from the central axis O'. That is, the rotation of the guide head 22 is centered around a portion on the first guide surface 35 near the portion surrounded by the dashed line in FIG. 6. Therefore, the first guide surface 35 guides the guide head 22 in a direction to overcome the step 101 (see the dashed line in FIG. 5). As shown in FIGS. 5 and 6, by rotating the guide tube 21 in a more pressed state, the groove 36 formed in the first guide surface 35 comes into contact with the edge 101b. In this state, by rotating the guide tube 21, the guide head 22 can overcome the step 101. Furthermore, even when the pressing force is small, as shown in FIG. 4, the guide head 22 does not necessarily slide against the step 101, as described above. Therefore, by rotating the guide tube 20 even from a state where the pressing force is small, the groove 36 comes into contact with the edge 101b. Even in this state, by rotating the guide tube 21, the guide head 22 can easily overcome the step 101. Here, a state in which the pushing is small refers to, for example, when the guide head 22 passes through multiple elbows, or when the guide head 22 extends deep into a long pipe.In these cases, the pushing force transmitted from the hand to the guide head 22 becomes smaller, and the state shown in Figure 4 is likely to occur. Even in such cases, it is possible to overcome the step in the curved pipe. As the guide head 22 rotates, the groove 36 that catches on the edge 101b of the step 101 changes appropriately.

[0052] In each of these patterns, the guide head 22 guided by the first guide surface 35 can insert the insertion portion 5 into the through-hole 32. As a result, the first guide surface 35 indirectly guides the insertion portion 5 in a direction that overcomes the step 101.

[0053] Such behavior of the guide head 22 is also the same when the guide tube 20 is removed from the pipeline 100. However, when the guide tube 20 is removed, the second guide surface 37 and the groove 38 mainly act in the same manner as the first guide surface 35 and the groove 36.

[0054] When passing over a step or the like in such a narrow space, it is desirable to retract the tip portion 11 into the guide tube 20 to prevent damage to the insertion portion 5. In this case, for example, it is desirable to align the position of the tip portion 11 of the endoscope 2 with the tip of the guide tube 20 and prohibit relative movement between the insertion portion 5 and the guide tube 20 in the direction of the central axis O (O') so that the tip portion 11 and bending portion 12 of the endoscope 2 do not protrude beyond the tip of the guide tube 20. Such prohibition of relative movement can be achieved, for example, by providing the handle 27 with a gripping structure that allows it to be fixed at any position on the flexible portion 13 of the endoscope 2. This fixing structure may be configured to be able to fix and release the fixation to and from the flexible portion 13 as needed. Furthermore, it is desirable that the handle 27 be configured to be rotatable relative to the coil 26. With this configuration, even if the guide tube 20 is rotated during pipe insertion and movement, the endoscope 2 does not rotate together with the guide tube 20, and stable image observation is possible without rotation. Since the guide tube 20 can be rotated without changing the position of the tip of the guide tube 20 and the position of the tip portion 11 of the endoscope 2 while fixed to the flexible portion 13 of the endoscope 2, it is possible to rotate only the guide tube 20 when passing over a step in the piping. Since the endoscope 2 can pass over a step without rotating the endoscope 2, examination is made easier. Furthermore, in order to advance the endoscope 2 further beyond the length of the guide tube 20 after passing over the step, the endoscope 2 can be pushed out from the tip of the guide tube 20 without elastically deforming the fixed cylinder 51 of the guide tube 20 and without fixing the insertion portion 5, thereby performing examination.

[0055] According to this embodiment, the guide head 22 is formed on the outer surface of the head body 30 in a region including the terminal end (front end) of the head body 30 in the direction of the central axis O', and includes a first guide surface 35 surrounding the through hole 32, and unevenness formed on the first guide surface 35 by a plurality of grooves 36. Furthermore, the unevenness of the first guide surface 35 extends in a direction radial from the through hole 32 in a region including the terminal end (front end) of the head body 30.

[0056] Similarly, the guide head 22 is formed on the outer surface of the head body 30 in a region including the terminal end (base end) of the head body 30 in the direction of the central axis O', and includes a second guide surface 37 surrounding the through hole 32, and unevenness formed on the second guide surface 37 by a plurality of grooves 38. Furthermore, the unevenness of the second guide surface 37 extends in a direction radial from the through hole 32 in a region including the terminal end (base end) of the head body 30.

[0057] As a result, the guide head 22 can guide the tip portion 11 so that it can accurately overcome steps inside the narrow space.

[0058] That is, for example, when the first guide surface 35 is in contact with the step 101 while being able to slide relative to the edge 101b, by the simple operation of simply pushing the guide tube 20, the first guide surface 35 can move the guide head 22 in a direction that overcomes the step 101.

[0059] Furthermore, for example, when the first guide surface 35 is in contact with the step 101 in a state where it is difficult for it to slide against the edge 101b of the step 101, the first guide surface 35 can move the guide head 22 in a direction that overcomes the step 101 by simply pushing in the guide tube 20 and rotating it.

[0060] In this case, the first guide surface 35 is provided on the outer surface of the head body 30 in a region including the terminal end (tip) of the head body 30 so as to surround the through hole 32. Furthermore, each groove 36 extends in the ejection direction from the through hole 32 in a region including the terminal end (tip) of the head body 30. With this configuration, each groove 36 is a groove with an open end (tip) in the traveling direction of the guide head 22. Therefore, the guide head 22 can easily insert the edge 101b of the step 101 into any of the grooves 36.

[0061] The guide head 22, which can overcome the step 101 in this manner, can insert the insertion portion 5 into the through-hole 32. This allows the guide head 22 to guide the tip portion 11 so as to accurately overcome the step inside the narrow space.

[0062] Here, the first and second guide surfaces 35, 37 are not limited to tapered surfaces formed on the outer peripheral surface of the head body 30. For example, as shown in FIGS. 7 and 8, the first guide surface 35 can be formed on the end surface (tip surface) of the head body 30. In this case, the basic shape of the first guide surface 35 is a flat surface perpendicular to the central axis O' of the head body 30. Although not shown, the basic shape of the second guide surface 37 can also be a flat surface perpendicular to the central axis O' of the head body 30.

[0063] 9, the tapered surfaces constituting the first and second guide surfaces 35, 37 may also be formed in a generally dome shape that curves in the gradient direction. That is, in this modification, the outer diameter of each tapered surface constituting the first and second guide surfaces 35, 37 changes nonlinearly with respect to the direction of the central axis O'.

[0064] 10, it is also possible to provide unevenness on only one of the first and second guide surfaces 35, 37. In the example shown in FIG. 10, the guide head 22 has unevenness only on the first guide surface 35. In the example shown in FIG. 10, each groove 36 extends in a radial direction from the through hole 32 while maintaining a constant groove width. In the example shown in FIG. 10, each groove 36 is locally arranged at multiple locations in the circumferential direction of the through hole 32.

[0065] Note that "having unevenness on the first and second guide surfaces 35, 37" does not prevent the unevenness from extending to the boundary of the tapered surface formed on the outer circumferential surface of the head body 30. For example, when a groove is provided on one or both of the first and second guide surfaces 35, 37, the recess of the groove may extend to the boundary of the tapered surface.

[0066] 11 and 12, the head body 30 may be made up of a plurality of members. For example, as shown in FIGS. 11 and 12, the head body 30 may include a base member 40 and a cover 41.

[0067] The base member 40 has a basic shape that is generally cylindrical. A through hole 32 is provided in the base member 40. The through hole 32 passes through the base member 40 along the central axis O' of the base member 40. In addition, a first tapered surface 40a and a second tapered surface 40b are provided in the distal and proximal regions of the base member 40, respectively.

[0068] The cover 41 is made of, for example, a metal pipe. A plurality of first notches 41a and a plurality of second notches 41b are provided in the distal and proximal regions of the cover 41, respectively. The cover 41 covers the outer periphery of the base member 40. The cover 41 is bent so that the distal and proximal regions of the cover 41 are inclined along the first tapered surface 40a and the second tapered surface 40b. As a result, the cover 41 forms a first guide surface 35 and a second guide surface 37 in the distal and proximal regions of the head main body 30. Furthermore, the cover 41 forms grooves 36 and grooves 38 in the first guide surface 35 and the second guide surface 37, respectively, by the first notches 41a and the second notches 41b.

[0069] Note that "having unevenness on the first and second guide surfaces 35, 37" does not prevent the unevenness from extending to the boundary of the tapered surface formed on the outer circumferential surface of the head body 30. For example, when a groove is provided on one or both of the first and second guide surfaces 35, 37, the recess of the groove may extend to the boundary of the tapered surface.

[0070] 13 and 14, the unevenness of the first guide surface 35 can be formed by a plurality of protrusions 45 provided on the first guide surface 35. Although not shown, a similar configuration can also be adopted for the second guide surface 37.

[0071] 13, each protrusion 45 extends in a radial direction from the through hole 32 while varying in width. Furthermore, each protrusion 45 is arranged at equal intervals in the circumferential direction of the through hole 32.

[0072] 14, each protrusion 45 extends radially from the through hole 32 while maintaining a constant width. Each protrusion 45 is locally arranged at a plurality of locations in the circumferential direction of the through hole 32.

[0073] Next, a second embodiment of the present technology will be described with reference to Fig. 15 to Fig. 17. In this embodiment, differences from the first embodiment will be mainly described. Other configurations similar to those in the first embodiment will be appropriately denoted by the same reference numerals and description thereof will be omitted.

[0074] Here, the endoscope 2 to which the guide tube 20 of this embodiment is applied has, for example, an annular groove 16 at the boundary between the bending section 12 and the flexible section 13.

[0075] As shown in FIG. 15, the tube main body 21 of this embodiment includes, for example, a coil 26 and a fixing mechanism 50.

[0076] The length of the coil 26 is set to, for example, approximately the same length as the bending portion 12 of the endoscope 2. As a result, the coil 26 covers the bending portion 12. At this time, the tip portion 11 is protected by the guide head 22. The coil 26 is formed, for example, by winding a wire having a circular or rectangular cross section into a coil. Such a coil 26 is slightly loosely wound. As a result, the coil 26 has flexibility that allows it to bend even when the endoscope 2 is bent. In addition, because the coil 26 is slightly loosely wound, the coil 26 contracts due to a force from the tip in the direction of the central axis O' of the through hole 32. However, the contraction amount of the coil 26 is set to a degree that does not cause the tip portion 11 to protrude significantly outside the guide head 22. The inner diameter of the coil 26 is set to be larger than the outer diameter of the insertion portion 5. As a result, the insertion portion 5 can be inserted into the coil 26.

[0077] The fixing mechanism 50 is a mechanism for detachably fixing the guide tube 20 to the insertion section 5 of the endoscope 2. This fixing mechanism 50 is provided at the base end of the coil 26. This allows the endoscope 2 to be used without protruding from the guide tube 22, with the distal end of the endoscope 2 and the distal end of the guide tube 22 aligned and fixed. The fixing mechanism 50 has a fixing barrel 51 and a cap 52.

[0078] In addition, the inner diameter of the guide head 22 near the first guide surface 35 may be made slightly smaller than the outer diameter of the tip 11 of the endoscope 2 so as not to obstruct the field of view of the endoscope 2, thereby preventing the tip 11 of the endoscope 2 from protruding from the tip of the guide tube 20.

[0079] The fixed cylinder 51 is connected to the base end of the coil 26. The fixed cylinder 51 has a male thread portion 51a on the outer periphery on the tip side.

[0080] The fixed barrel 51 also has a plurality of slits 51b on the base end side of the male thread portion 51a. Each slit 51b extends in the direction of the central axis O. The provision of these slits 51b allows the base end side of the fixed barrel 51 to elastically deform in the inner diameter direction.

[0081] Furthermore, the fixed barrel 51 has a plurality of claws 51c on the inner periphery of the base end portion. Each claw 51c protrudes in the direction of the inner diameter of the fixed barrel 51.

[0082] The cap 52 is configured as a cylindrical member that can be attached to the outer periphery of the fixed barrel 51. The cap 52 has a female thread portion 52a on the inner periphery on the tip side. The female thread portion 52a can be screwed onto the male thread portion 51a of the fixed barrel 51.

[0083] The cap 52 also has a protrusion 52b on the inner periphery closer to the base end than the female thread portion 52a. This protrusion 52b is, for example, in the shape of a ring extending in the inner periphery direction of the cap 52. The inner diameter of this protrusion 52b is set smaller than the outer diameter of the fixed barrel 51.

[0084] The fixing mechanism 50 configured in this manner is disposed with the claw portion 51c aligned with the groove 16 of the insertion section 5 (see FIG. 17). Then, the female thread portion 52a of the cap 52 is screwed onto the male thread portion 51a of the fixed barrel 51. This screwing moves the cap 52 toward the distal end of the fixed barrel 51. As the cap 52 moves, the protrusion 52b elastically deforms the proximal end side of the fixed barrel 51 in the inner diameter direction. As a result, the claw portion 51c of the fixed barrel 51 engages with the groove 16 of the insertion section 5. Then, the engagement of the claw portion 51c with the groove 16 fixes the guide tube 20 to the insertion section 5. This fixation prevents the guide tube 20 from rotating relative to the insertion section 5. Therefore, when the endoscope 2 is rotated, the guide tube 20 also rotates, and the guide head 22 at the distal end can also rotate. The surface of the groove 55a may be roughened to more reliably fix the guide tube 20. Alternatively, instead of a cylindrical shape, a structure in which flat surfaces are provided according to the number of slits 57b (positions of the claw portions 57c) may be used.

[0085] With this configuration, the guide tube 20 can be made compact.

[0086] Next, a third embodiment of the present technology will be described with reference to Fig. 18 to Fig. 20. In this embodiment, differences from the first embodiment will be mainly described. Other configurations similar to those in the first embodiment will be appropriately denoted by the same reference numerals and description thereof will be omitted.

[0087] In this embodiment, the tube main body 21 includes, for example, the coil 26, the connecting tube 55, and a handle (not shown). As described above, the coil 26 is formed by winding, for example, a wire having a circular or rectangular cross section into a coil. Such a coil 26 can be tightly wound throughout, or a portion of the distal end (approximately the same length as the bending portion 12 of the endoscope 2) can be loosely wound.

[0088] The length of the coil 26 is set, for example, to be approximately the same as the length of the insertion section 5, or shorter than the length of the insertion section 5 depending on the application. The usage of each length is as described above.

[0089] The connecting pipe 55 is provided at the tip of the coil 26. The connecting pipe 55 has an annular groove 55a on its outer periphery.

[0090] The guide head 22 includes a head body 30 and a fixing mechanism 56 .

[0091] The fixing mechanism 56 is a mechanism for detachably fixing the guide head 22 to the tip end of the tube main body 21. The fixing mechanism 56 is provided at the base end of the head main body 30. The fixing mechanism 56 has a fixing tube 57 and a cap 58.

[0092] The fixed cylinder 57 is provided at the base end of the head body 30. The fixed cylinder 57 has a male thread portion 57a on the outer periphery on the tip side.

[0093] The fixed barrel 57 also has a plurality of slits 57b on the proximal side of the male thread portion 57a. Each slit 57b extends in the direction of the central axis O'. The provision of these slits 57b allows the proximal side of the fixed barrel 57 to elastically deform in the inner diameter direction.

[0094] Furthermore, the fixed barrel 57 has a plurality of claws 57c on the inner periphery of the base end portion. Each claw 57c protrudes in the direction of the inner diameter of the fixed barrel 57.

[0095] The cap 58 is configured as a tubular member that can be attached to the outer periphery of the fixed barrel 57. The cap 58 has a female thread portion 58a on the inner periphery on the tip side. The female thread portion 58a can be screwed onto the male thread portion 57a of the fixed barrel 57.

[0096] The cap 58 also has a protrusion 58b on the inner periphery closer to the base end than the female thread portion 58a. This protrusion 58b is, for example, in the shape of a ring extending in the inner periphery direction of the cap 58. The inner diameter of this protrusion 58b is set smaller than the outer diameter of the fixed barrel 57.

[0097] The fixing mechanism 56 configured in this manner is positioned with the claws 57c aligned with the grooves 55a of the connecting tube 55. The female threads 58a of the cap 58 are then threaded onto the male threads 57a of the fixed tube 57. This threading moves the cap 58 toward the tip of the fixed tube 57. As the cap 58 moves, the protrusions 58b elastically deform the base end of the fixed tube 57 in the radially inward direction. This causes the claws 57c of the fixed tube 57 to engage with the grooves 55a of the connecting tube 55. The engagement of the claws 57c with the grooves 55a fixes the guide head 22 to the tube body 21. This fixation prevents the guide head 22 from rotating relative to the tube body 21. The surface of the grooves 55a may be roughened for more reliable fixation. Alternatively, a structure having flat surfaces corresponding to the number of slits 57b (the positions of the claws 57c) may be used instead of a cylindrical shape.

[0098] According to this embodiment, the guide head 22 of the guide tube 20 can be arbitrarily replaced depending on the shape of the narrow space in which the endoscope 2 is used.

[0099] Next, a fourth embodiment of the present technology will be described with reference to Fig. 21 to Fig. 23. In this embodiment, differences from the first embodiment will be mainly described. Other configurations similar to those in the first embodiment will be appropriately denoted by the same reference numerals and description thereof will be omitted.

[0100] Here, the endoscope 2 to which the guide tube 20 of this embodiment is applied has, for example, an annular groove 16 at the boundary between the tip portion 11 and the bending portion 12.

[0101] In this embodiment, the tube body 21 includes, for example, a coil 26, a connecting tube 60, and a handle (not shown).

[0102] The length of the coil 26 is set, for example, to be approximately the same as the length of the insertion section 5, or shorter than the length of the insertion section 5 depending on the application. The usage of each length is as described above.

[0103] The connecting pipe 60 is provided at the tip end of the coil 26. The connecting pipe 60 has a plurality of fitting protrusions 60a as first fitting portions on the outer periphery on the tip side. Each fitting protrusion 60a protrudes in the outer periphery direction of the connecting pipe 60.

[0104] The guide head 22 includes a head body 30 and a fixing mechanism 61 .

[0105] The fixing mechanism 61 is a mechanism for detachably fixing the guide head 22 to the insertion section 5. The fixing mechanism 61 is provided at the base end of the head main body 30. The fixing mechanism 61 has a fixing cylinder 62 and a cap 63.

[0106] The fixed cylinder 62 is provided at the base end of the head body 30. The fixed cylinder 62 has a male thread portion 62a on the outer periphery on the tip side.

[0107] The fixed barrel 62 also has a plurality of slits 62b on the proximal side of the male thread portion 62a. Each slit 62b extends in the direction of the central axis O'. The provision of these slits 62b allows the proximal side of the fixed barrel 62 to elastically deform in the inner diameter direction.

[0108] Furthermore, the fixed barrel 62 has a plurality of claws 62c on the inner periphery of the base end portion. Each of the claws 62c protrudes in the direction of the inner diameter of the fixed barrel 62.

[0109] The cap 63 is configured as a cylindrical member that can be attached to the outer periphery of the fixed barrel 62. The cap 63 has a female thread portion 63a on the inner periphery on the tip side. The female thread portion 63a can be screwed onto the male thread portion 62a of the fixed barrel 62.

[0110] The cap 63 also has a protrusion 63b on the inner periphery closer to the base end than the female thread portion 63a. This protrusion 63b is, for example, in the shape of a ring extending in the inner periphery direction of the cap 63. The inner diameter of this protrusion 63b is set smaller than the outer diameter of the fixed barrel 62.

[0111] Furthermore, a plurality of fitting recesses 63c are provided at the base end of the cap 63 as second fitting portions. Each fitting recess 63c is configured, for example, as a notch that is open on the base end side. This allows each fitting protrusion 60a of the tube body 21 to be inserted into each fitting recess 63c from the base end side of the cap 63. This allows each fitting recess 63c to be fitted with each fitting protrusion 60a.

[0112] The fixing mechanism 61 configured in this manner is positioned with the claws 62c aligned with the grooves 16 of the insertion section 5. The female threads 63a of the cap 63 are then threaded onto the male threads 62a of the fixed barrel 62. This threading moves the cap 63 toward the distal end of the fixed barrel 62. As the cap 63 moves, the protrusions 63b elastically deform the proximal end of the fixed barrel 62 in the inner diameter direction. This causes the claws 62c of the fixed barrel 62 to engage with the grooves 16 of the insertion section 5. The engagement of the claws 62c with the grooves 16 fixes the guide head 22 in the groove 16 between the distal end 11 and the bending section 12 of the insertion section 5. This fixation prevents the guide head 22 from rotating relative to the insertion section 5. For more reliable fixation, the surface of the grooves 16 may be roughened in the same manner as above. Alternatively, a structure having flat surfaces corresponding to the number of slits 62b (the positions of the claws 62c) may be used instead of a cylindrical shape.

[0113] Furthermore, the tube body 21 is detachably coupled to the guide head 22 fixed to the insertion section 5 on the insertion section 5. That is, by sliding the tube body 21 toward the distal end of the insertion section 5, the fitting protrusions 60a fit into the fitting recesses 63c (see FIG. 23). This allows the rotational force of the tube body 21 about the central axis O to be transmitted to the guide head 22. On the other hand, by sliding the tube body 21 toward the proximal end of the insertion section 5, the fitting protrusions 60a are disengaged from the fitting recesses 63c (see FIG. 22). This prevents the rotational force of the tube body 21 about the central axis O from being transmitted to the guide head 22. Within the reach of the guide tube 20, insertion is performed with the fitting protrusions 60a fitted into the fitting recesses 63c as shown in FIG. 23, and steps can be overcome. When advancing the endoscope 2 further beyond the reach of the guide tube 20, the flexible portion 13 of the endoscope 2 is pushed in from the base end side of the guide tube 20, thereby releasing the engagement between each engaging protrusion 60a and each engaging recess 63c as shown in Figure 22, and pushing the endoscope 2 out from the tip of the guide tube 20.

[0114] Next, a fifth embodiment of the present technology will be described with reference to Fig. 24 to Fig. 26. In this embodiment, differences from the first embodiment will be mainly described. Other configurations similar to those in the first embodiment will be appropriately denoted by the same reference numerals and description thereof will be omitted.

[0115] In this embodiment, the tube body 21 includes, for example, a coil 26 and a handle 27 .

[0116] The length of the coil 26 is set, for example, to be approximately the same as the length of the insertion section 5, or shorter than the length of the insertion section 5 depending on the application. The usage of each length is as described above.

[0117] The guide head 22 has a head body 70. The basic shape of the head body 70 is a thin, generally pipe shape. That is, the head body 70 has a through hole 71. The through hole 71 penetrates the head body 70 along the central axis O' of the head body 70.

[0118] The outer diameter of the head body 70 is set to be slightly larger than the outer diameter of the coil 26. The inner diameter of the through hole 71 is set to be approximately the same as or slightly larger than the inner diameter of the tube body 21.

[0119] 25, a plurality of engagement protrusions 72 are provided on the base end side of the head body 70. Each engagement protrusion 72 protrudes in the radially inner direction of the head body 70. These engagement protrusions 72 engage with the tip end of the coil 26. This connects the guide head 22 to the tube body 21.

[0120] A first guide surface 75 is formed on the outer surface on the tip side of the head main body 70. The first guide surface 75 is configured by, for example, the tip surface of the head main body 70. In other words, the first guide surface 75 is formed in a region that includes the tip (end) of the head main body 70.

[0121] A plurality of notches 76 are formed in the first guide surface 75. Each notch 76 has, for example, a V-shape in the depth direction (the direction of the central axis O'). These notches 76 each form a recess in the first guide surface 75 that extends in a direction radially from the through-hole 71.

[0122] In this embodiment, the notches 76 are locally arranged at a plurality of locations in the circumferential direction of the through-hole 71.

[0123] The guide tube 20 configured in this manner assists the insertion of the insertion portion 5 into a duct 100 or the like. For example, as shown in FIG. 26 , when the insertion portion 5 passes over a step 101 in the duct 100, the first guide surface 75 guides the insertion portion 5 in a direction that overcomes the step 101. That is, when the first guide surface 75 abuts against the step 101, the user rotates the guide tube 20 while pushing it into the duct 100. As a result, one of the notches 76 formed in the first guide surface 75 catches on an edge 101b of the step 101 (see FIG. 26 ). The guide head 22 then further rotates around the catch portion. Due to this rotation, the first guide surface 75 guides the guide head 22 in a direction that overcomes the step 101.

[0124] Here, for example, as shown in FIG. 27, it is also possible to locally arrange a plurality of notches 76 provided in the first guide surface 75 at a plurality of locations in the circumferential direction of the through-hole 71.

[0125] Also, for example, as shown in FIG. 28, the notches 76 provided in the first guide surface 75 can be arranged over the entire area of the through-hole 71 in the circumferential direction.

[0126] In this case, for example, as shown in FIG. 29, it becomes possible to easily hook one of the notches 76 onto the edge 101b of the step 101.

[0127] Also, for example, as shown in FIG. 30, it is possible to form a second guide surface 77 made of a tapered surface on the base end side of the head main body .

[0128] In this case, for example, as shown in FIG. 31, when the insertion section 5 is removed from the duct 100, it is less likely to get caught on the inner part of the curved duct, and it is possible to guide the insertion section 5 in a direction that overcomes the step 101 as shown in FIG. 32.

[0129] 33, it is also possible to provide a second guide surface 77 and a plurality of notches 78 on the base end side of the head main body 70. In the example shown in FIG. 33, the second guide surface 77 is formed on the base end surface of the head main body 70. Furthermore, the notches 78 are locally arranged at a plurality of locations in the circumferential direction of the through hole 71.

[0130] 34, the central axis O' of the head body 70 can be inclined relative to the central axis O of the tube body 21. In addition, as shown in FIG.

[0131] 35, when the guide tube 20 is rotated, the first guide surface 75 is displaced in a direction perpendicular to the central axis O. This allows the first guide surface 75 to more effectively guide the insertion portion 5 in a direction that overcomes the step 101.

[0132] Next, a sixth embodiment of the present technology will be described with reference to Fig. 36. In this embodiment, differences from the first embodiment will be mainly described. Other configurations similar to those of the first embodiment will be appropriately denoted by the same reference numerals and description thereof will be omitted.

[0133] The tube body 21 includes, for example, a coil 26, a connecting tube 80, and a handle (not shown).

[0134] The length of the coil 26 is set, for example, to be approximately the same as the length of the insertion portion 5, or shorter than the length of the insertion portion 5 depending on the application. The usage is as described above.

[0135] The connecting pipe 80 has a generally pipe-like shape and is provided with a screw hole 80a on the side thereof.

[0136] 36, the base ends of a plurality of types of guide heads 22A to 22C can be selectively connected to this connecting pipe 80. A screw hole 22a is provided on the side of each of the guide heads 22A to 22C at a position corresponding to the screw hole 80a. As a result, each of the guide heads 22A to 22C is fixed to the connecting pipe 80 using a screw 81.

[0137] The head body 30 of the guide head 22C has a basic shape of, for example, a polygonal prism.

[0138] The techniques described in the above embodiments and modifications are not limited to those embodiments, and various modifications may be made in the implementation stage without departing from the spirit of the invention. For example, it goes without saying that the configurations of the above embodiments and modifications may be appropriately combined.

[0139] Furthermore, each embodiment and each modification includes inventions at various stages, and various inventions can be extracted by appropriate combinations of the disclosed constituent elements.

[0140] For example, if some constituent elements are deleted from all the constituent elements shown in the embodiments, and the stated problem can be solved and the stated effect can be obtained, then the configuration from which these constituent elements are deleted can be extracted as an invention. [Explanation of symbols]

[0141] 1. Endoscopic device 2. Endoscopy 3... Device body 5... Insertion section 6 … Operation section 6a ... Curved joystick 6b ... Operation button 7... Universal Code 11 … Tip part 11a ... Observation window 11b … Lighting window 11c ... Imaging unit 12 ... curved section 13 … Flexible part 14 ... Control unit 15... Display unit 16 … Groove 20... Guide tube 21...Tube body 22 ... Guide head 22A~22C ... Guide head 22a ... screw hole 25 … Spiral tube 26... Coil 27 ... Handle 30... Head body 31 ... Joint 32 ... through hole 35 ... First guide surface 36 … Groove 37 ... Second guide surface 38 … Groove 40... Base material 40a ... First tapered surface 40b ... Second tapered surface 41 ... Cover 41a ... First notch 41b ... Second notch 45 … Protrusion 50…Fixing mechanism 51 … Fixed cylinder 51a ... Male thread 51b ... slit 51c … Claw part 52 ... Cap 52a … Female thread 52b…Protrusion 55 ... Connecting pipe 55a … Groove 56…Fixing mechanism 57 … Fixed cylinder 57a ... Male thread 57b ... slit 57c … Claw part 58... Cap 58a … Female thread 58b… Protrusion 60 ... connecting pipe 60a ... mating projection 61…Fixing mechanism 62 … Fixed cylinder 62a ... Male thread 62b ... slit 62c … Claw part 63 ... Cap 63a … Female thread 63b … Protrusion 63c ... fitting recess 70... Head body 71 ... through hole 73 … Engaging protrusion 75 ... First guide surface 76 ... cutout 77 ... Second guide surface 78 ... Cutout 80 ... connecting pipe 80a ... screw hole 81...Screw 100 … Pipeline 101...step 101a … surface 101b... Edge O … Central axis O' … Central axis

Claims

1. A head body, a through hole that penetrates the head body along a central axis direction of the head body and through which an insertion portion of an endoscope can be inserted; a guide surface formed on an outer surface of the head body in a region including an end of the head body in the central axis direction, the guide surface surrounding the through hole; and a concavo-convex shape formed on the guide surface, The guide head is characterized in that the irregularities extend in a direction radially from the through hole in a region including the terminal end of the head body.

2. 2. The guide head according to claim 1, wherein the unevenness is formed by providing a recess in the guide surface.

3. 3. The guide head according to claim 2, wherein the recess is a groove.

4. The head body includes a base member and a cover that covers the base member.

4. The guide head according to claim 3, wherein the groove is formed by a notch provided in the cover.

5. The guide head according to claim 3, wherein the grooves extend in radial directions from the through-hole while varying the width of the grooves.

6. 4. The guide head according to claim 3, wherein the grooves extend in radial directions from the through-holes while maintaining a constant width of the grooves.

7. The guide head according to claim 2 , wherein the recess is a notch.

8. 2. The guide head according to claim 1, wherein the unevenness is formed by providing a protrusion on the guide surface.

9. The guide head according to claim 8, wherein the protrusions extend in radial directions from the through-holes while varying the width of the protrusions.

10. The guide head according to claim 8, wherein the protrusions extend in radial directions from the through holes while maintaining a constant width of the protrusions.

11. The guide head according to claim 1 , wherein the guide surface is formed on an outer peripheral surface of the head body.

12. The guide head according to claim 11, wherein the guide surface is a tapered surface.

13. 2. The guide head according to claim 1, wherein the guide surface is formed on an end surface of the head body.

14. 2. The guide head according to claim 1, further comprising a fixing mechanism that detachably fixes the head body to the insertion portion in a state where the insertion portion is inserted into the through hole.

15. a tube body through which an insertion section of an endoscope can be inserted; a guide head disposed on the distal end side of the tube body, The guide head is A head body, a through hole that penetrates the head body along a central axis direction of the head body and through which the insertion portion can be inserted; a guide surface formed on an outer surface of the head body in a region including an end of the head body in the central axis direction, the guide surface surrounding the through hole; and a concavo-convex shape formed on the guide surface, The guide tube is characterized in that the irregularities extend in a direction radially from the through hole in a region including the terminal end of the head body.

16. 16. The guide tube according to claim 15, wherein the guide head includes a fixing mechanism for detachably fixing the base end of the head body to the tip end of the tube body.

17. the tube body has a first fitting portion at a tip end thereof, The guide tube described in claim 15, characterized in that the guide head comprises a fixing mechanism that detachably fixes the base end of the head body to the insertion portion when the insertion portion is inserted into the through hole, and a second fitting portion that is provided at the base end of the fixing mechanism and fits into the first fitting portion.

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