JP4708589B2 - Endoscope flexible tube - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a flexible tube for an endoscope.
[0002]
[Prior art]
In general, a flexible tube for an endoscope used for an insertion portion of an endoscope or a connection portion with a light source device can be used as a core material having a hollow portion in which the outer periphery of a spiral tube is covered with a mesh tube (braided body). It has a configuration in which a flexible outer skin is coated.
[0003]
Here, the medical endoscope needs to be sterilized and sterilized every time it is used in order to prevent infectious diseases and the like. As a method for sterilization and sterilization, high-pressure steam sterilization (autoclave) has been widespread instead of using a conventional disinfectant solution. In this high-pressure steam sterilization, the endoscope is exposed to high-temperature and high-pressure steam at about 135 ° C. and about 2 atm for about 5 to 20 minutes, for example.
[0004]
In order to make the endoscope compatible with this high-pressure steam sterilization, the outer skin of the flexible tube for the endoscope is required to have heat resistance that can withstand high temperatures during high-pressure steam sterilization. Therefore, a silicone rubber having excellent heat resistance and good moldability is used as a material for the outer skin of the endoscope flexible tube.
[0005]
However, such a flexible tube for an endoscope has the following problems. That is, since the outer skin of the endoscope flexible tube made of a material mainly made of silicone rubber is easily permeable to water vapor, the hollow portion of the endoscope flexible tube is subjected to high-pressure steam sterilization. For example, a built-in material such as a fiber bundle is exposed to water vapor and the deterioration thereof is accelerated.
[0006]
In order to solve this problem, it is considered that the outer shell of the endoscope flexible tube has a two-layer structure of a material such as fluorine rubber having water vapor barrier properties and heat resistance and silicone rubber. In this case, since the vulcanization conditions are different between fluororubber and silicone rubber, it is necessary to perform extrusion molding in two steps to coat the outer shell onto the core material, resulting in a decrease in production efficiency and production cost. The problem of causing an increase arises.
[0007]
[Problems to be solved by the invention]
An object of the present invention is to provide a flexible tube for an endoscope that can prevent deterioration and damage of a built-in object during high-pressure steam sterilization or the like and is easy to manufacture.
[0008]
[Means for Solving the Problems]
Such an object is achieved by the present inventions (1) to (6) below.
(1) a core material having a spiral tube formed by spirally winding a belt-like body with a gap ;
A flexible tube for an endoscope having an outer skin coated on the outer periphery of the core material,
An inner skin having a water vapor barrier property is provided inside the core material ,
The outer diameter of the endothelium is naturally larger than the inner diameter of the spiral tube and smaller than the outer diameter,
The endothelium has a protruding portion that protrudes in a convex shape toward the outer peripheral side in a state where the flexible tube for endoscope is stretched, and the protruding portion enters the gap of the spiral tube. A flexible tube for an endoscope.
[0009]
As a result, it is possible to prevent a built-in item from being deteriorated or damaged during high-pressure steam sterilization or the like, and to obtain an endoscope flexible tube that is easy to manufacture.
Moreover, sufficient mechanical strength can be obtained for the endoscope flexible tube.
In addition, even when the endoscope flexible tube is subjected to deformation such as bending or twisting, the endothelium can be less likely to move (displace) with respect to the core material.
Further, the flexibility (softness) of the endoscope flexible tube is not impaired, and the durability of the endothelium can be improved.
[0010]
(2) The flexible tube for an endoscope according to (1), wherein the inner skin is made of a material containing a fluorine resin.
As a result, particularly excellent water vapor barrier properties and heat resistance can be obtained for the endothelium.
[0011]
(3) The flexible tube for an endoscope according to the above (1) or (2), wherein the endothelium is formed in a tube shape and then inserted into a hollow portion of the core member.
[0012]
Thereby, endothelium can be installed easily and can be manufactured more easily.
[0018]
(4) The flexible tube for an endoscope according to any one of (1) to (3), wherein the outer skin is made of a material containing silicone rubber.
Thereby, the heat resistance and moldability excellent in the outer skin can be obtained.
[0019]
(5) The flexible tube for an endoscope according to any one of (1) to (4), wherein a thickness of the endothelium is 0.03 to 2 mm.
[0020]
As a result, the endothelium has sufficient water vapor barrier properties, and does not cause an increase in the diameter of the endoscope flexible tube or a decrease in flexibility.
[0021]
(6) The endoscope flexible tube according to any one of (1) to (5), wherein the water vapor permeability of the endothelium is 10 g / m ² · 24 hrs · 40 ° C. · 90% RH or less.
[0022]
Thereby, the built-in thing arrange | positioned in the hollow part of the flexible tube for endoscopes can be protected more reliably.
[0023]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the flexible tube for endoscopes of the present invention will be described in detail based on a preferred embodiment shown in the accompanying drawings.
[0024]
FIG. 5 is an overall view showing an example of an endoscope having a flexible tube for an endoscope according to the present invention.
First, an overall configuration of an endoscope having an endoscope flexible tube according to the present invention will be described with reference to FIG. In the following description, the right side in FIG. 5 is referred to as “base end”, and the left side is referred to as “tip”.
[0025]
An endoscope (fiberscope) 10 shown in FIG. 5 includes a long insertion portion flexible tube 11 having flexibility (flexibility) and a bending portion provided on the distal end side of the insertion portion flexible tube 11. 12, provided on the proximal end side of the insertion portion flexible tube 11, provided on the proximal end side of the operation portion 13, provided on the proximal end side of the operation portion 13, provided on the proximal end side of the operation portion 13. An eyepiece 14 for directly observing an image, a long connecting portion flexible tube 15 whose one end is connected to the operation portion 13, and a light source insertion portion provided on the other end of the connecting portion flexible tube 15 16.
[0026]
Among these, the insertion part flexible tube 11 and the bending part 12 comprise the insertion part inserted in the lumen | bore of a biological body. Inside the insertion portion flexible tube 11 and the bending portion 12 (hollow portion), for example, a built-in object (not shown) such as an optical fiber, an electric cable, a cable, or a tube is disposed and inserted.
[0027]
An operation lever 17 is installed in the operation unit 13. When the operation lever 17 is operated, a wire (not shown) disposed in the insertion portion flexible tube 11 is pulled, and the bending portion 12 is bent in two directions, and the bending direction and the degree of bending are remotely controlled. can do.
[0028]
The connecting portion flexible tube 15 and the light source insertion portion 16 constitute a connecting portion for a light source device (not shown). That is, a light source connector 161 is installed at the distal end of the light source insertion portion 16. When the endoscope 10 is used, the light source connector 161 is inserted into the light source device, so that the endoscope 10 and the light source are connected. The apparatus is optically connected.
[0029]
The light emitted from the light source built in the light source device is emitted from the light source connector 161, the light source insertion portion 16, the connection portion flexible tube 15, the operation portion 13, the insertion portion flexible tube 11, and the light source device 161. It passes through a light guide (not shown) by an optical fiber bundle arranged continuously in the bending portion 12, and is irradiated on the observation site from the distal end portion 121 of the bending portion 12 to illuminate it.
[0030]
The reflected light (subject image) from the observation site illuminated by the illumination light is sent to an image guide (not shown) by an optical fiber bundle arranged continuously in the insertion portion flexible tube 11 and the operation portion 13. And transmitted to the eyepiece unit 14.
[0031]
An eyepiece lens (not shown) is installed inside the eyepiece 14, and reflected light that has reached through the image guide is observed through the eyepiece lens.
[0032]
The flexible tube for an endoscope of the present invention can be applied to the insertion portion flexible tube 11 and the connection portion flexible tube 15 in the endoscope 10 as described above.
[0033]
In addition, the flexible tube for an endoscope of the present invention is not limited to a fiber endoscope such as the endoscope 10, but can be an insertion portion flexible tube and a connection portion in various endoscopes such as an electronic endoscope. Needless to say, it can be applied to a flexible tube.
[0034]
Next, the endoscope flexible tube of the present invention will be described.
FIG. 1 is a longitudinal sectional view showing an embodiment of the flexible tube for an endoscope of the present invention, FIG. 2 is a longitudinal sectional view showing a curved state of the flexible tube for an endoscope shown in FIG. 1, and FIG. It is a longitudinal cross-sectional view for demonstrating the magnitude relationship between the outer diameter of endothelium and the inner diameter of a helical tube.
[0035]
The endoscope flexible tube 1 shown in FIGS. 1 and 2 includes a core member 2 having a hollow portion 24 and an outer skin 3 that covers the outer periphery of the core member 2. For example, a built-in object (not shown in the drawing) such as an optical fiber, an electric cable, a cable, or a tube can be arranged and inserted into the hollow portion 24.
[0036]
The core material 2 is a long object composed of a spiral tube 21 and a mesh tube (braided body) 22 covering the outer periphery of the spiral tube 21. The core member 2 has an effect of reinforcing the endoscope flexible tube 1. In particular, by combining the spiral tube 21 and the mesh tube 22, the endoscope flexible tube 1 can ensure a sufficient mechanical strength. Although not shown, the core material 2 can have higher mechanical strength by providing two or three spiral tubes 21.
[0037]
The spiral tube 21 is formed by winding a band-shaped material spirally with a uniform diameter with a gap 25 therebetween. For example, stainless steel or copper alloy is preferably used as the material constituting the strip.
[0038]
The mesh tube 22 is formed by braiding a plurality of metal or non-metallic thin wires 23. As a material constituting the thin wire 23, for example, stainless steel, a copper alloy or the like is preferably used. Further, at least one of the thin wires 23 forming the mesh tube 22 may be coated with a synthetic resin (not shown).
[0039]
The outer periphery of the core material 2 is covered with a flexible outer skin 3.
The constituent material of the outer skin 3 is not particularly limited, but preferably includes silicone rubber (silicone-based material). Since silicone rubber has excellent heat resistance, it is possible to make the endoscope flexible tube 1 compatible with high-pressure steam sterilization (autoclave). Therefore, even when high-pressure steam sterilization is repeatedly performed, there is little deterioration, and the life of the endoscope flexible tube 1 can be extended. Moreover, since silicone rubber is excellent in moldability, this can be easily performed when the outer skin 3 is coated on the outer periphery of the core material 2 by, for example, extrusion molding.
[0040]
The thickness of the outer skin 3 is not particularly limited, but is usually preferably 0.1 to 2 mm, and more preferably 0.2 to 1 mm.
[0041]
The outer skin 3 is preferably covered so that at least a part of the mesh tube 22 is embedded in the outer skin 3. Thereby, the following effects are obtained.
[0042]
The bonding force between the outer skin 3 and the mesh tube 22 becomes strong, and the outer skin 3 is difficult to peel (separate) from the mesh tube 22. Thereby, the flexible tube 1 for endoscopes has excellent elasticity.
-The durability of the outer skin 3 is improved, and cracks and the like are less likely to occur.
The flexibility (elasticity) of the outer skin 3 can be adjusted as desired by selecting the material of the mesh tube 22, the density of the braid, and adjusting the thickness of the embedded portion.
-The outer diameter of the flexible tube for endoscope 1 is reduced (or the inner diameter is increased) by the thickness of the mesh tube 22 while maintaining the performance such as the strength of the flexible tube 1 for endoscope. )can do.
[0043]
Such an endoscope flexible tube 1 according to the present invention is characterized in that an endothelium 4 having a water vapor barrier property is provided inside a core member 2.
[0044]
That is, the inner periphery of the spiral tube 21 is covered with the endothelium 4 having a water vapor barrier property.
[0045]
Here, the water vapor barrier property means that the water vapor permeability is preferably 10 g / m ² · 24 hrs · 40 ° C. · 90% RH or less, more preferably 2 g / m ² · 24 hrs · 40 ° C. · 90% RH or less. Say that. This water vapor permeability is measured by the method described in JIS K7129 (Method A).
[0046]
Although it does not specifically limit as a constituent material of the endothelium 4, For example, tetrafluoroethylene resin (polytetrafluoroethylene: PTFE), tetrafluoroethylene-hexafluoropropylene copolymer (FEP resin), tetrafluoroethylene -Perfluoroalkoxyethylene copolymer (PFA resin), tetrafluoroethylene-ethylene copolymer (ETFE resin), vinylidene fluoride resin (polyvinylidene fluoride: PVDF), vinyl fluoride resin (PVF resin), chlorotri It is preferable to include a fluororesin such as a fluoroethylene resin (CTFE resin) or an ethylene-chlorotrifluoroethylene resin (ECTFE resin). Thereby, the endothelium 4 has excellent water vapor barrier properties and heat resistance.
[0047]
Moreover, although the thickness of the endothelium 4 is not specifically limited, Usually, it is preferable that it is 0.03-2 mm, and it is more preferable that it is 0.05-1.5 mm.
[0048]
If the thickness of the endothelium 4 is less than the lower limit value, depending on the material of the endothelium 4, sufficient water vapor barrier properties may not be obtained. Moreover, it may become easy to be damaged by many use.
[0049]
On the other hand, if the thickness of the endothelium 4 exceeds the upper limit, the hollow portion 24 becomes narrow, which may cause inconvenience in the arrangement of the built-in objects. Moreover, the bending rigidity of the flexible tube 1 for endoscopes may increase, and the flexibility (softness | flexibility) of the flexible tube 1 for endoscopes may fall.
[0050]
By providing the endothelium 4 as described above, even when high-pressure steam sterilization or the like is performed on the endoscope 10, even when water vapor permeates the outer skin 3 of the endoscope flexible tube 1. Since the water vapor is blocked by the endothelium 4, the water vapor is prevented from entering the hollow portion 24 through the gap 25 of the spiral tube 21. As a result, it is possible to prevent deterioration or damage due to water vapor that has entered, for example, optical fibers, cables, tubes, and the like disposed in the hollow portion 24 of the endoscope flexible tube 1.
[0051]
As shown in FIG. 1, the endothelium 4 is formed with a protruding portion 41 that enters the gap 25 of the spiral tube 21 when the endoscope flexible tube 1 is stretched.
[0052]
The protruding portion 41 is formed so as to bend and protrude in a convex shape toward the outer peripheral side in a state where the endoscope flexible tube 1 is stretched.
[0053]
In other words, the endothelium 4 has an outer diameter and an inner diameter larger than those of the other portions at the position of the gap 25 of the spiral tube in a state where the endoscope flexible tube 1 is stretched. That is, the endothelium 4 is in a slack state at the protruding portion 41 and has a serpentine shape as a whole.
Providing such a protrusion 41 has the following three advantages.
[0054]
[First advantage of the protrusion 41]
The protruding portion 41 of the endothelium 4 has an anchor effect that makes the endothelium 4 difficult to move with respect to the spiral tube 21 (particularly, difficult to move in the longitudinal direction). Therefore, even when deformation such as bending and twisting is repeatedly applied to the endoscope flexible tube 1, there is an advantage that the endothelium 4 is difficult to move (difficult to shift) with respect to the spiral tube 21.
[0055]
[Second advantage of the protrusion 41]
As shown in FIG. 2, when the endoscope flexible tube 1 is in a curved state, the gap 25 of the spiral tube 21 is enlarged on the outside of the curve, and the gap 25 of the spiral tube 21 is reduced on the inside of the curve. As a result, on the curved outer side, the protruding portion 41 of the inner skin 4 extends in the longitudinal direction so as to extend straight, and is in a state of being retracted from the gap 25. On the inner side of the curve, the protrusion 41 of the inner skin 4 is contracted in the longitudinal direction so as to be folded.
[0056]
Thus, since the endothelium 4 has a margin (sag) in which the protruding portion 41 extends in the longitudinal direction, the protruding portion 41 can absorb the elongation on the curved outer side. Therefore, the endothelium 4 on the outside of the curve does not hinder the bending of the endoscope flexible tube 1. Thereby, as the 2nd advantage by the protrusion part 41, the flexible tube 1 for endoscopes has the outstanding flexibility (softness | flexibility).
[0057]
[Third advantage of the protrusion 41]
Moreover, since the protrusion 41 absorbs the elongation on the curved outer side, the endothelium 4 is not stretched on the curved outer side. As a result, even if the endoscope flexible tube 1 is curved, no pulling force is applied to the endothelium 4, so that deterioration such as pinholes and cracks in the endothelium 4 occurs even after repeated use. Is unlikely to occur. Therefore, as a third advantage by the protrusion 41, even when the thickness of the endothelium 4 is relatively thin, excellent water vapor barrier properties can be maintained over a long period of time.
[0058]
Although the method of installing such an endothelium 4 is not particularly limited, for example, it can be easily installed by the following method.
[0059]
As shown in FIG. 3, a core material 2 coated with an outer skin 3 is prepared. That is, this is the same state as a normal endoscope flexible tube.
[0060]
Next, the endothelium 4 is formed as a tubular member by a method such as extrusion.
[0061]
At this time, as indicated by a one-dot chain line in FIG. 3, the outer diameter φD of the endothelium 4 formed in a tube shape in a natural state (a state where no external force is applied) is larger than the inner diameter φd ₁ of the spiral tube 21 (φD> φd ₁ ) is preferred. The φD is more preferably smaller than the outer diameter φd ₂ of the spiral tube 21 (φD <φd ₂ ).
[0062]
When the outer diameter φD in the natural state of the endothelium 4 formed in a tube shape is in the above range, the endothelium 4 can obtain excellent adhesion to the inner periphery of the spiral tube 21 and the protrusion 41 has a suitable size. Formed.
[0063]
Next, such a tube-like endothelium 4 is stretched (pulled) in the longitudinal direction. As a result, the outer diameter of the endothelium 4 is reduced and changes to φD ′ where φD ′ <φD. At this time, the outer diameter φD ′ of the reduced endothelium 4 is made smaller than the inner diameter φd ₁ of the spiral tube 21 (φD ′ <φd ₁ ).
[0064]
Next, the tube-shaped endothelium 4 reduced in diameter in this way is inserted into the spiral tube 21 and the longitudinal tension applied to the endothelium 4 is released.
[0065]
In this state, the endothelium 4 is heated to, for example, the heat deformation temperature. By this heating, the endothelium 4 expands in an attempt to return to the original diameter (natural diameter). Thereby, the endothelium 4 is integrated with the core material 2. That is, the endothelium 4 is in close contact with the inner periphery of the spiral tube 21 at the portion that contacts the spiral tube 21, and forms a protrusion 41 at the position of the gap 25 in the spiral tube 21.
[0066]
The endothelium 4 can be easily installed on the endoscope flexible tube 1 by the method described above. Therefore, according to the present invention, an endoscope flexible tube suitable for high-pressure steam sterilization or the like can be manufactured by a simple method, and production efficiency can be improved and manufacturing cost can be reduced. Moreover, according to the method mentioned above, the protrusion part 41 can be formed easily and suitably.
[0067]
In the present invention, the flexibility (elasticity) of the endoscope flexible tube 1 can be adjusted as desired by appropriately selecting the thickness and material of the endothelium 4.
[0068]
FIG. 4 is a longitudinal sectional view of a connecting portion between the endoscope flexible tube and the light source insertion portion of the present invention. In the following description, the left side in FIG. 4 is referred to as “one end” and the right side is referred to as “the other end”.
[0069]
With reference to the figure, the structural example of the connection part with respect to the other site | part of the flexible tube for endoscopes of this invention is demonstrated.
[0070]
As shown in FIG. 4, in the endoscope 10, the other end side of the connection portion flexible tube 15 to which the endoscope flexible tube of the present invention is applied is connected to the light source insertion portion 16 via a base 90. Connected to one end.
[0071]
The base 90 has a substantially cylindrical shape, and its one end 901 has an outer diameter that is substantially the same as the outer diameter of the connecting portion flexible tube 15.
[0072]
The other end of the connecting portion flexible tube 15 is processed to peel the outer skin 3 to the extent that the mesh tube 22 is exposed, and this portion is inserted into one end 901 of the base 90.
[0073]
A brazing hole 902 is formed at one end 901 of the base 90, and the brazing hole 902 is brazed. Thereby, the connection part flexible tube 15 (helical tube 22) and the nozzle | cap | die 90 are adhering.
[0074]
The outer periphery of the boundary between the base 90 and the connecting portion flexible tube 15 may be covered with a heat shrinkable tube 91. Thereby, the airtightness and liquid tightness of this boundary part improve more.
[0075]
The inner skin 4 of the connecting portion flexible tube 15 extends beyond the other end surface 151 of the core material 2 and the outer skin 3 in the other end direction, and reaches the inside of the intermediate portion 903 of the base 90.
[0076]
An inner skin pressing ring 904 having a substantially annular shape is installed inside the intermediate portion 903 of the base 90, and the inner skin 4 is connected to the inner peripheral surface of the intermediate portion 903 and the inner skin pressing ring 904 by the inner skin pressing ring 904. It is fixed inside the base 90 so as to be sandwiched between the outer peripheral surfaces of the base. Thereby, the airtightness and liquid-tightness of the connection part of the nozzle | cap | die 90 and the connection part flexible tube 15 are ensured.
[0077]
One end of the light source insertion portion 16 is provided with a protrusion 162 that protrudes in an annular shape toward the other end, and the protrusion 162 is inserted into the other end 905 of the base 90. .
[0078]
A screw hole is formed in the other end 905 of the base 90, and a screw 92 is screwed into the screw hole, and a tip of the screw 92 projects from the inside of the other end 905. The tip of the screw 92 is inserted into a recess provided on the outer periphery of the protruding portion 162 of the light source insertion portion 16, whereby the base 90 is fixed to the light source insertion portion 16.
[0079]
In addition, a substantially cylindrical anti-folding rubber 93 having a portion whose outer diameter and inner diameter gradually decrease toward one end direction is installed on the outer periphery of the connection portion between the connection portion flexible tube 15 and the light source insertion portion 16. Thus, sufficient strength is secured at the connecting portion.
[0080]
O-rings 94 and 95 are respectively installed between the anti-breaking rubber 93, the base 90, and the light source insertion portion 16, whereby the airtightness of the connection portion between the base 90 and the light source insertion portion 16 and Liquid tightness is ensured.
[0081]
With such a configuration, sufficient airtightness and liquid tightness are ensured in the connection portion between the connection portion flexible tube 15 and the light source insertion portion 16. Thereby, in the endoscope 10, the penetration of water vapor into the interior during high-pressure steam sterilization or the like can be more reliably prevented, and deterioration or damage of built-in objects such as an optical fiber bundle can be surely prevented.
[0082]
As mentioned above, although the flexible tube for endoscopes of this invention was described about embodiment of illustration, this invention is not limited to this, Each part which comprises the flexible tube for endoscopes is the same. It can be replaced with any structure that can perform its function.
[0083]
For example, the outer skin or the inner skin may be formed of a multilayer laminate in which all or part of the outer skin and the inner skin are laminated with a plurality of layers (particularly layers of different materials).
[0084]
In addition, the protruding portion of the endothelium may be, for example, one that protrudes to the outer peripheral side by becoming thicker than the other portion, or one that is inserted so as to melt into the gap of the core material.
[0085]
【The invention's effect】
As described above, according to the present invention, water vapor can be prevented from entering the hollow portion of the endoscope flexible tube. Thereby, even when placed in a moist heat environment such as high-pressure steam sterilization, it is possible to prevent deterioration and damage of the built-in objects disposed in the hollow portion of the endoscope flexible tube.
[0086]
In particular, when the endothelium is made of a material containing a fluororesin, particularly excellent water vapor barrier properties and heat resistance can be obtained for the endothelium. Therefore, an endoscope flexible tube particularly suitable for high-pressure steam sterilization can be obtained.
[0087]
Further, when the outer skin is made of a material containing silicone rubber, excellent heat resistance can be obtained for the outer skin. Therefore, an endoscope flexible tube particularly suitable for high-pressure steam sterilization can be obtained. In this case, excellent moldability during production can also be obtained.
[0088]
In addition, when the endothelium is formed into a tube shape and then inserted into the hollow portion of the core material, it can be easily manufactured while exhibiting the above effects, improving the production efficiency and manufacturing. Cost can be reduced.
[Brief description of the drawings]
FIG. 1 is a longitudinal sectional view showing an embodiment of a flexible tube for an endoscope of the present invention.
2 is a longitudinal sectional view showing a curved state of the flexible tube for an endoscope shown in FIG. 1. FIG.
FIG. 3 is a vertical cross-sectional view for explaining the magnitude relationship between the outer diameter of the endothelium formed in a tube shape and the inner and outer diameters of the spiral tube.
FIG. 4 is a longitudinal sectional view of a connection portion between the endoscope flexible tube and the light source insertion portion of the present invention.
FIG. 5 is an overall view showing an example of an endoscope having a flexible tube for an endoscope according to the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Endoscope flexible tube 2 Core material 21 Spiral tube 22 Reticulated tube 23 Fine wire 24 Hollow part 25 Crevice 3 Outer skin 4 Endothelium 41 Protrusion part 10 Endoscope 11 Insertion part Flexible pipe 12 Curved part 121 Tip part 13 Operation part 14 eyepiece 15 connection portion flexible tube 151 other end surface 16 light source insertion portion 161 light source connector 162 projecting portion 17 operating lever 90 base 901 one end 902 brazing hole 903 intermediate portion 904 endothelium pressing ring 905 other end 91 Heat-shrinkable tube 92 Screw 93 Bending rubber 94, 95 O-ring

Claims (6)

A core material having a spiral tube formed by winding a band-like body spirally with a gap, and
A flexible tube for an endoscope having an outer skin coated on the outer periphery of the core material,
An inner skin having a water vapor barrier property is provided inside the core material ,
The outer diameter of the endothelium is naturally larger than the inner diameter of the spiral tube and smaller than the outer diameter,
The endothelium has a protruding portion that protrudes in a convex shape toward the outer peripheral side in a state where the flexible tube for endoscope is stretched, and the protruding portion enters the gap of the spiral tube. A flexible tube for an endoscope.   The flexible tube for an endoscope according to claim 1, wherein the endothelium is made of a material containing a fluorine resin.   The flexible tube for an endoscope according to claim 1 or 2, wherein the endothelium is formed in a tube shape and then inserted into a hollow portion of the core material. The flexible tube for an endoscope according to any one of claims 1 to 3, wherein the outer skin is made of a material containing silicone rubber. The flexible tube for an endoscope according to any one of claims 1 to 4, wherein the endothelium has a thickness of 0.03 to 2 mm. The flexible tube for an endoscope according to any one of claims 1 to 5, wherein water vapor permeability of the endothelium is 10 g / m ² · 24 hrs · 40 ° C · 90% RH or less.

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