JPH05228106A - Production of channel tube for endoscope - Google Patents

Abstract

PURPOSE:To easily and efficiently produce the good channel tube for an endoscope. CONSTITUTION:This process for production has a stage for forming spiral grooves for housing a coil member 31 by heating deformation on the outer peripheral surface of a channel tube blank material 2, a 2nd stage for treating the surface part of the spiral grooves by chemicals, a 3rd stage for winding and mounting the coil member to the spiral grooves after the end of the 2nd stage, a 4th stage for adhering and fixing both ends of the coil member 31 to the channel tube blank material 2 after the end of the 3rd stage and a 5th stage for coating the outside surface of the coil member 31 mounted on the outside surface of the channel tube blank material 2 and the spiral grooves with an elastic material 64.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a channel tube for an endoscope such as a channel tube for inserting a treatment tool or the like incorporated in an endoscope or a channel tube for inserting an operation wire.

[0002]

2. Description of the Related Art In general, a channel tube incorporated in an endoscope is subjected to a bending action associated with the bending of an endoscope insertion portion, and therefore it is required to have flexibility that does not impair the bending.
Further, the strength of the waist that does not bend or buckle even when subjected to a bending action is required.

For this reason, in this type of endoscope channel tube, a spiral groove is formed on the outer circumference and a steel wire is wound along the spiral groove (Japanese Utility Model Publication No. 59-40002). See the bulletin).

[0004]

However, in this conventional endoscope channel tube, the spiral groove formed on the outer periphery of the channel tube is manufactured by mechanical cutting using a cutting tool. The channel tube is easily scratched during the processing. In addition, they often cracked or broken. Furthermore, since the spiral groove is formed by cutting, so-called burrs are likely to occur at the edge. Moreover, it was difficult to round the edges of the spiral groove.

In this type of endoscope channel tube, it is necessary to wind a steel wire along the spiral groove on the outer periphery of the channel tube. The first conceivable method of this method is to use a coiled wire in advance. This is a method in which the one formed in the above is inserted from one end side of the tube, and after this insertion, both ends of the coil member are adhesively fixed to the channel tube.

However, this method of assembling the coil has the drawbacks that the work of inserting the coil member is rather troublesome and that the coil member mounted spreads out, and the coiled steel wire tends to come apart. Further, since both ends of the coil-shaped steel wire jump up, it was difficult to make the steel wire closely contact with the spiral groove of the channel tube. Also, even if both ends of the coiled steel wire wound around the channel tube are fixed to the spiral groove of the channel tube with an adhesive, it is difficult to fix them tightly and the adhesive hangs down before the adhesive hardens, and easily drips, There was a tendency that the outer diameter was partially thickened.

Further, it has been considered to apply an elastic agent to the outer circumference of this kind of endoscope channel tube in which a steel wire is wound along a spiral groove on the outer circumference, but this elastic agent is applied by a brush or the like. In the case of simply applying, there is a problem that the application becomes uneven and the elastic agent is biased to the lower side before being dried and the outer diameter of the tube is locally expanded.

The present invention has been made in view of the above problems, and an object thereof is to provide a high-quality endoscope channel in which a reinforcing coil member is wound around a predetermined range of a fluororesin channel tube. An object of the present invention is to provide a method of manufacturing a channel tube for an endoscope, which can manufacture the tube easily and efficiently.

[0009]

As conceptually shown in FIG. 1, the present invention provides an endoscope channel tube in which a reinforcing coil member is wound around a predetermined range of a fluororesin channel tube. In the manufacturing method described above, a first step of forming a spiral groove accommodating the coil member on the outer peripheral surface of a predetermined range of the channel tube by heat deformation, and a second step of treating the surface portion of the spiral groove with a chemical agent
And the third step, after the second step is finished, the coil member is wound around the spiral groove to be mounted, and after the third step, both ends of the coil member are bonded and fixed to the channel tube. It is a manufacturing method of a channel tube for endoscopes which has the 4th process and the 5th process of coating an elastic agent on the outer surface of the channel tube and the outer surface of the coil member mounted in the spiral groove. (EN) A high-quality endoscope channel tube in which a reinforcing coil member is wound in a predetermined range of a fluororesin channel tube is easily and efficiently manufactured.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Each step of the method of the present invention will be sequentially described with reference to the drawings. First, an example of the first step of forming a spiral groove for accommodating the coil member on the outer peripheral surface of the channel tube by heat deformation will be described.

FIG. 2 shows a manufacturing apparatus used in the first step. This manufacturing apparatus includes a rotary driving device 4 having a collet chuck 3 for holding a channel tube material 2 having a core metal 1 inserted therein, a wire rod supplying device 6 for feeding a grooved wire rod 5, and a long channel tube material having a core metal 1 inserted therein. It has a core metal receiving jig 7 for preventing shake of the core 2 during rotation, and a centering jig 8 for supporting the core metal 1. The wire feed device 6 is provided with a grooved wire guide 9 for guiding the grooved wire 5 to be fed. Further, the collet chuck 3 is provided with a set screw 10 for fixing the tip of the grooved wire rod 5 fed from the wire rod supply device 6. Reference numeral 11 is a heat gun for heating.

Next, the first step will be described in order of work. (1) Obtain a channel tube material 2 by cutting a Teflon (fluorine resin) tube to the specified dimensions. (2) Insert the core metal 1 having an outer diameter matching the inner diameter into the inner cavity of the channel tube material 2. (3) The channel tube material 2 is held by the collet chuck 3. At this time, tape is wrapped around the part of the channel tube material 2 to be sandwiched, or a soft material or the like is fixed to the collet chuck 3 side. Make sure that the channel tube material 2 is not scratched. (4) The centering jig 8 is applied to the tip of the core metal 1 to perform centering. (5) The grooved wire 5 is fed out from the wire feeder 6, the tip of the grooved wire 5 is passed through the wire guide 9, and the tip of the grooved wire 5 is wound around the set screw 10 of the collet chuck 3 to be fixed. The tension applied to the grooved wire 5 is adjusted by operating an adjusting screw (not shown) of the slip preventing means for applying the tension to the grooved wire 5. (6) By driving the rotation driving device 4 to rotate the channel tube material 2, the channel tube material 2 is rotated.
The grooved wire 5 is wound around the outer periphery of the. At this time, the rotation driving device 4 moves the fixed head portion of the wire guide 9 in the direction A in FIG. 2 along the longitudinal axis direction of the channel tube material 2 at a speed proportional to the amount of rotation of the channel tube material 2. Therefore, the grooved wire 5 is wound at a predetermined pitch. It should be noted that the wire guide 9 is provided with a non-slip means for giving tension to the grooved wire rod 5 to be pulled out. Therefore, the grooved wire 5 is wound around the outer circumference of the channel tube material 2 by tension. (7) In the winding work of the above (6), while the channel tube material 2 is heated by the heat gun 11, the grooved wire 5 is wound around the softened peripheral surface portion. For this reason,
The circumferential surface portion of the channel tube material 2 around which the grooved wire 5 is wound undergoes heat deformation and is pressed by the grooved wire 5 to form the spiral groove 12. (8) When the grooved wire 5 has been wound around the predetermined range of the channel tube material 2, the grooved wire 5 is cut by the feeding port of the wire guide 9, and the set screw 10 of the collet chuck 3 is loosened to remove the grooved wire 5. Disconnect. (9) By rotating the grooved wire 5 wound around the channel tube material 2 in the same direction as it was wound while applying tension to the end of the grooved wire 5 that matches the set screw 10 side, the wound grooved wire 5 is wound. Remove from Channel Tube Material 2.

By this step, however, the spiral groove 12 for accommodating the coil member, which will be described later, can be easily formed on the outer peripheral surface of the channel tube material 2 within a predetermined range by heat deformation. Therefore, a stable roundness is naturally formed on the edge of the spiral groove 12 without so-called flash. In addition, the channel tube material 2 is not broken or scratched.

The channel tube material 2 thus formed by heating and deforming the spiral groove 12 is subjected to a so-called tetra-H treatment for enhancing the adhesiveness of the surface of the channel tube material 2 by using a chemical for a post-process.

FIG. 3 shows an apparatus used in another embodiment of the first step of forming the spiral groove 12 for accommodating the coil member on the outer peripheral surface of the channel tube material 2 by heating and deforming it. This device uses a processing wire 16 that is heated by a heating device 15 and loops like a hook instead of the grooved wire 5 that is wound around the outer peripheral surface of the channel tube material 2 to form the spiral groove 12. That is, the processing wire 16 is hung on the peripheral surface of the channel tube material 2 and is moved in the direction A in FIG. 3 along the longitudinal axis direction of the channel tube material 2 as the channel tube material 2 rotates. Therefore, the channel tube material 2
It is pressed spirally on the outer circumference of the and is deformed by its own heat. Thereby, the spiral groove 12 can be formed by heating and deforming on the outer periphery of the channel tube material 2. Others are the same as those in the above-mentioned embodiment.

FIG. 4 shows an apparatus used in still another embodiment of the first step of forming the spiral groove 12 for accommodating the coil member on the outer peripheral surface of the channel tube material 2 by heating and deforming it. This device has a heating mold 21 that can be divided into two, and a hole 22 through which the channel tube material 2 is passed and a spiral projection 23 formed in this hole 22 are formed between the abutting inner surfaces. The channel tube material 2 is passed through the hole 22 of the heating mold 21, and the channel tube material 2 is moved in the direction of A in FIG. 4 along the longitudinal axis direction as the channel tube material 2 rotates. Then, the outer periphery of the channel tube material 2 is pressed against by the spiral protrusion 23 and is deformed by its own heat. Thereby, the spiral groove 12 can be formed by heating and deforming on the outer periphery of the channel tube material 2. Others are the same as those in the above-mentioned one embodiment. In this embodiment, the work of removing the grooved wire 5 and the like after forming the spiral groove 12 can be omitted.

FIG. 5 shows an apparatus used in still another embodiment of the first step in which the spiral groove 12 for accommodating the coil member is formed on the outer peripheral surface of the channel tube material 2 by heat deformation. This device is a heating mold that can be split in two.
There is a channel tube material 2 on the inner surface of this butting.
And a spiral projection 27 formed in the hole 26. When the channel tube material 2 is inserted into the hole 26 of the heating die 25 and sandwiched and heated, the channel tube material 2 is pressed against the outer circumference of the channel tube material 2 by the spiral ridge 27 and is deformed by its own heat. The groove 12 is formed. According to this method, the spiral groove 12 can be heated and deformed without rotating the heating die 25.

FIG. 6 shows a modification of the first step in which the spiral groove 12 for accommodating the coil member is heat-deformed and formed on the outer peripheral surface of the channel tube material 2. In this embodiment, a coil member 28 having a diameter smaller than the outer diameter of the channel tube material 2 is expanded and fitted into the outer circumference of the coil winding range of the channel tube material 2 through a cored bar 29.
Then, all of them are put in a heating furnace and heated. Then, the coil member 2 is formed on the outer circumference of the channel tube material 2.
The spiral groove 12 is formed by tightening at 8. Also in this method, the spiral groove 12 can be formed by heating and deforming without rotating the heating die 25 and the like.

The method shown in FIGS. 5 and 6 does not require a rotating mechanism or a head moving mechanism, and the spiral groove 1 can be formed in a short time.
2 can be formed.

Next, the step of winding the coil member 31 around the spiral groove 12 of the channel tube material 2 will be described. FIG. 7 shows an apparatus used for the process. This device includes a rotary drive device 3 having a collet chuck 33 for holding the channel tube material 2 having a cored bar 32 inserted therethrough.
4, a centering jig 35 that supports the tip of the core 32, a rotation fixing tool 36 that holds the other end of the coil member 31, and a moving base 37. The collet chuck 33 can be replaced with another one depending on the diameter of the channel tube material 2. The centering jig 35 can move in the axial direction of the channel tube material 2. The rotation fixing device 36 is configured such that the tip 38 supporting one end of the coil member 31 can freely rotate with respect to the fixing frame 39 with extremely light torque, and the fixing frame 39 is formed on the moving base 37. Further, it has a spherical moving element 42 that slides in the feeding groove 41, and the moving element 42 moves along the feeding groove 41. The feed groove 41 includes the rotary drive device 34 and the centering jig 3.
5 is formed on the same plane as the central axis method of the channel tube material 2 attached to the device 5 on the side closer to the centering jig 35 than the rotary drive device 34. This inclination angle can be arbitrarily changed, but the coil member 31 wound around the spiral groove 12 of the channel tube material 2 is adjusted so that it is always wound with a constant tension. In addition, the moving base 37
Is movable in a direction perpendicular to the central axis direction of the channel tube material 2, and the tension at the time of winding the coil member 31 can be adjusted by the movement. A stopper 43 is provided at the upper end of the slant of the feeding groove 41.
Is provided, and when the moving element 42 hits the stopper 43, the rotation of the rotary drive device 34 is also stopped. When processing the long channel tube material 2, a jig is installed to prevent runout of the rear end.

Next, the procedure for winding the coil member 31 around the spiral groove 12 of the channel tube material 2 using this apparatus will be described. (1) Insert the core metal 32 into the channel tube material 2 and hold it in the collet chuck 33 of the rotation driving device 34. The tip of the cored bar 32 on the other side of this is supported by a centering jig 35 so that the cored bar 32 can rotate without swinging. (2) One end of the coil member 31 is wound around the channel tube material 2 for one to two turns to be fixed, and the other end of the coil member 31 is fixed to the tip 38 of the rotation fixing tool 36. (3) The position of the moving base 37 is selected and adjustment is performed to extend it to a length where a predetermined initial tension (to the extent that the coil member 31 does not cause permanent distortion) is produced. Further, the inclination of the feed groove 41 is adjusted so that the tension is always constant according to the coil member 31. (4) When the rotation drive device 34 is operated to rotate the channel tube material 2, the channel tube material 2 is rotated.
The coil member 31 is wound around the spiral groove 12 from one end side thereof. As the coil member 31 is wound in this way, a rotational force due to twisting is generated on the side of the rotation fixture 36, but the tip 38 supporting one end of the coil member 31 rotates extremely lightly with respect to the fixed frame 39. , The twist is erased. (5) As the coil member 31 is wound around the spiral groove 12 of the channel tube material 2 in this way, the rotation fixing tool 36 moves to the centering jig 35 side along the feeding groove 41. Meanwhile, the spiral groove 1 of the channel tube material 2
The tension of the coil member 31 wound around 2 is always kept constant. (6) When the mover 42 hits the stopper 43 at the upper end of the inclination of the feed groove 41, the rotation of the rotary drive device 34 stops and the winding stops. (7) After the coil member 31 has been wound, the coil member 31 is cut at both ends of the channel tube material 2.

FIG. 8 shows an apparatus used in another embodiment of the step of winding the coil member 31 around the spiral groove 12 of the channel tube material 2. The collet chuck 33 holding the channel tube material 2 having the cored bar 32 inserted therein is provided with a set screw 46 for attaching one end of the wire 45 of the coil member 31. In addition, the coil member 31
The element wire 45 is drawn out through a tension adjusting jig 48 supported by a moving head 47. The moving head 47 moves in parallel with the channel tube 2 at a constant speed set in proportion to the rotation amount of the channel tube 2.

Next, the procedure of winding the wire 45 of the coil member 31 around the spiral groove 12 of the channel tube material 2 using this apparatus will be described.

(1) The core metal 32 on the channel tube material 2
Is inserted and held by the collet chuck 33 of the rotation drive device 34. Further, the tip end of the cored bar 32 on the other side is supported by a centering jig 35 so that the cored bar 32 can rotate without swinging. (2) One end of the wire 45 of the coil member 31 which is fed from the tension adjusting jig 48 of the moving head 47 is attached to the collet chuck 3.
It is clamped by the set screw 46 located at 3 and stopped. (3) The channel tube material 2 is rotated by the rotation driving device 34, and the moving head 47 is moved at a constant speed set in proportion to the rotation amount of the channel tube material 2. That is, the wire 45 is wound around the spiral groove 12 of the channel tube material 2 at the pitch of the spiral groove 12 of the channel tube 2. Further, a constant tension is applied to the wire 45 wound around in this way when it is unwound through the tension adjusting jig 48, and the wire 45 is reliably wound while maintaining a constant tension. And
It stops when the coil member 31 winds over a certain predetermined range of the spiral groove 12. (4) After this winding is completed, both ends of the coil member 31 are fixed with an instant adhesive so as not to come off. After this fixing, the wire 45 is cut and separated from the coil member 31.

According to the method of winding the coil member 31 around the spiral groove 12 of the channel tube material 2 using the apparatus shown in FIGS. 7 and 8, the coil member 31 can be evenly arranged with respect to the spiral groove 12 of the channel tube material 2. It is possible to easily carry out the loading work of closely winding. Further, since the winding is performed while applying a constant tension, the tightening force always acts on the channel tube 2. Further, since the coil end is fixed, the coil end can be prevented from jumping up. When the device shown in FIG. 7 is used, the diameter of the coil member 31 wound around the spiral groove 12 of the channel tube material 2 is set smaller than the diameter of the channel tube material 2 formed at the bottom of the spiral groove 12. The winding force can be improved. Further, when the device shown in FIG. 8 is used, the wire-shaped element wire 45 may be wound, so that the manufacturing cost can be reduced.

FIG. 9 or FIG. 10 shows a method of loading the coil member 31 in the spiral groove 12 of the channel tube material 2 as described above and then fixing both ends of the coil member 31 to the channel tube material 2 with an adhesive. Shown respectively.

The method shown in FIG. 9 is performed as follows. First, as shown in (A), the adhesive 51 is applied to both ends of the coil member 31. Then, as shown in (B), the non-adhesive heat-shrinkable tubes 52 are respectively inserted and covered in the vicinity where the adhesive 51 is applied. Thereafter, as shown in (C), the non-adhesive heat-shrinkable tube 52 is heated by the heat gun 53 while rotating the entire channel tube material 2 having the non-adhesive heat-shrinkable tube 52 mounted thereon. The heat shrink tube 52 is uniformly shrunk. The adhesive 51 is cured as it is, and after this curing, the non-adhesive heat-shrinkable tube 52 is peeled off as shown in (D).

As described above, the method of fixing both ends of the coil member 31 with the adhesive prevents the adhesive 51 after application from dripping or dropping, and prevents the adhesive 51 from being thickened uniformly, without partially thickening it. Can be cured. Further, it is possible to prevent the bonded portion from becoming thicker than the outer diameter of the channel tube material 2.

In the method shown in FIG. 10, the dripping portion of the applied adhesive agent 51 is polished by a polishing machine 55 to remove the dripping. That is, in the polishing machine 55, the rotating device portion 57 that rotatably holds the cored bar 56 that inserts and holds the channel tube material 2 has the XY table 58.
Installed on the base 59 via the XY table 5
Numeral 8 is capable of moving the core metal 56 in the axial direction and moving orthogonally thereto. This movement in each direction is performed by the handles 61, 6
Operated in 2. Further, the base 59 is provided with a polishing machine 55 having a grinding wheel 60. A plurality of core bars 56 are selectively used according to the inner diameter of the channel tube material 2 to be inserted therein.

Then, on the core metal 56 of the XY table 58,
Insert and attach the channel tube material 2 that has been bonded. The handle 61 is operated to move the XY table 58 and the bonded portion thereof is rotated by the grinding machine 55.
Contact. Further, the channel tube material 2 is rotated by one hand to move in the longitudinal axis direction, and is polished so that the bonded portion on the entire circumference becomes uniform. According to this, the bonded portion can be quickly and uniformly polished, and the variation in diameter can be eliminated. Further, it is possible to prevent the bonded portion from becoming thicker than the outer diameter of the channel tube material 2.

Next, a process of applying a reinforcing elastic material to the outer periphery of the channel tube material 2 obtained through the above-mentioned steps will be described with reference to FIG. In advance, a core metal is inserted into the channel tube material 2 around which the coil member 31 is wound, and the tip is sealed with a sealing tape 63 or the like. Then, as shown in (A) to (B), the channel tube material 2 is immersed in the elastic agent 64 having a constant viscosity from the tip side, and then pulled up as shown in (C). An elastic material 64 is applied to the outer peripheral surface of the material 2 to form an elastic material. Then, as shown in (D), the non-adhesive heat-shrinkable tube 66 is covered, and as shown in (E), it is heated by the heat gun 67 to shrink the heat-shrinkable tube 66. As a result, the elastic agent 64 applied to the outer peripheral surface of the channel tube material 2 is pressed and uniformly applied. When the elastic agent 64 is hardened, the heat shrinkable tube 66 is peeled off and removed. Therefore, the elastic material is uniformly applied to the outer periphery of the channel tube material 2. Further, the deviation of the elastic agent and the bulge of the outer diameter due to the application of the elastic agent 64 can be regulated, and the outer diameter accuracy can be stabilized.

As a method of hardening the elastic agent 64 applied to the outer peripheral surface of the channel tube material 2, an apparatus as shown in FIG. 12 may be used. That is, FIG.
In the apparatus shown by 2, numeral 70 is a chuck 7 that supports one end of the channel tube material 2 into which a core metal 71 is inserted.
It is a jig having 1. A belt 72 transmits the rotation of the motor 73 to the channel tube material 2 having a cored bar inserted therein.

When the elastic agent 64 applied to the outer periphery is dried as described above, the channel tube material 2 is supported by the jig 70, and the rotation of the motor 73 is rotated by the belt 72. Communicate to 2. The channel tube material 2 is rotated at a low speed until the elastic agent 64 thus applied is cured.
When the elastic agent 64 is a thermosetting type, it is put in a drying oven or the like to be cured.

[0034]

As described above, according to the present invention, it is possible to easily and efficiently manufacture an endoscope channel tube in which a reinforcing coil member is wound in a predetermined range of a fluororesin channel tube. In addition to the above, it is possible to manufacture a high-quality endoscope channel tube without the conventional defects.

[Brief description of drawings]

FIG. 1 is an explanatory view conceptually showing steps of a manufacturing method of the present invention.

FIG. 2 is an explanatory view of an apparatus used in a process of forming a spiral groove on the outer circumference of a channel tube.

FIG. 3A is an explanatory view of another device used in the step of forming the spiral groove on the outer periphery of the channel tube, and FIG. 3B is a front view of a main part thereof.

FIG. 4A is an explanatory view of still another device used in the step of forming a spiral groove on the outer periphery of the channel tube,
(8) is a cross-sectional view of the main part thereof.

FIG. 5 is an explanatory view of still another device used in the step of forming a spiral groove on the outer circumference of the channel tube.

FIG. 6 is an explanatory view of still another device used in the step of forming the spiral groove on the outer periphery of the channel tube.

FIG. 7 is an explanatory diagram of an apparatus used in a step of winding a coil member around a spiral groove on the outer periphery of a channel tube.

FIG. 8 is an explanatory view of another device used in the step of winding the coil member around the spiral groove on the outer periphery of the channel tube.

9 (A), (B), (C), and (D) are explanatory views of a process of adhering both ends of a coil member wound around a spiral groove on the outer periphery of a channel tube to the channel tube.

FIG. 10 is an explanatory view of another treatment device used in the step of adhering both ends of the coil member wound around the spiral groove on the outer periphery of the channel tube to the channel tube.

11 (A), (B), (C), (D), and (E) are explanatory views of a process of coating the outer periphery of a channel tube around which a coil member is wound with an elastic agent.

FIG. 12 is an explanatory view of an apparatus used in a step of coating an elastic agent on the outer circumference of a channel tube around which a coil member is wound.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Core metal, 2 ... Channel tube material, 5 ... Grooving wire material, 11 ... Heat gun, 12 ... Spiral groove, 15 ... Heating device, 16 ... Processing wire, 21 ... Heating die, 22 ... Hole,
25 ... Heating mold, 26 ... Hole, 28 ... Coil member, 31 ...
Coil member, 45 ... Element wire, 51 ... Adhesive agent, 52 ... Heat shrink tube, 55 ... Polishing machine, 64 ... Elastic agent.

Claims (1)

[Claims] 1. A method of manufacturing a channel tube for an endoscope in which a reinforcing coil member is wound around a predetermined range of a fluororesin channel tube, wherein the coil member is housed on an outer peripheral surface of the predetermined range of the channel tube. The first step of forming the spiral groove by heat deformation, the second step of treating the surface portion of the spiral groove with a chemical, and the second step after the second step is finished, the coil member is wound around the spiral groove and mounted. A third step, and a fourth step after the third step is completed, in which both ends of the coil member are adhered and fixed to the channel tube, and an outer surface of the channel tube and an outer surface of the coil member attached to the spiral groove. A fifth step of coating an elastic agent, and a method of manufacturing a channel tube for an endoscope, including: