JP2005198903A - Flexible tube for endoscope and endoscope - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a flexible tube for an endoscope having an excellent curving operablilty whose shape does not change even the tube is bent repeatedly, and also to provide an endoscope provided with the same. <P>SOLUTION: The flexible tube (an insertion section flexible tube 1) for an endoscope of the invention has a tubular core member 2 and a shell 3 covering the outer circumference of the core member 2. The core member 2 comprises an inner spiral tube 21A formed by winding a strip material spirally, an outer spiral tube 21B formed on the outer circumference of the inner spiral tube 21A by winding the strip material spirally in the direction opposite to the inner spiral tube 21A, and a mesh tube 22 covering the outer circumference of the outer spiral tube 21B. The width of the strip material on the outer circumference of the inner spiral tube 21A is smaller than that of the strip material on the inner circumference of the inner spiral tube 21A. In addition, the width of the strip material on the inner circumference of the outer spiral tube 21B is smaller than that of the strip material on the outer circumference of the outer spiral tube 21B. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to an endoscope flexible tube and an endoscope.

  An endoscope flexible tube is used for connection with an insertion portion of an endoscope or a light source. The endoscope flexible tube has, for example, a configuration in which a tubular core material is covered with an outer skin made of synthetic resin, synthetic rubber, or the like.

  Such a flexible tube for an endoscope must bend freely along the inner wall of the body cavity, and the distal end portion is twisted in any of the circumferential directions with respect to the twisting in the circumferential direction at the proximal end portion. Even if it exists, it must have a predetermined torque transmission property to follow. For this reason, conventionally, the core member has two inner and outer spiral tubes formed by winding strips in opposite directions, and a mesh tube (braid) covering the outer periphery of the outer spiral tube. (For example, refer to Patent Document 1).

  However, each spiral tube has a shape in which the edge of the strip-like material is relatively square, so when the flexible tube for endoscope is bent, The edge of the strip of the spiral tube is easily caught between the strips of the other spiral tube. If the operation is continued as it is, the strip of one spiral tube enters between the strips of the other spiral tube, and further, the strip of the inner spiral tube gets over the outer spiral tube to the outer peripheral side. Even when the endoscope flexible tube is extended from a bent state to a straight state, the endoscope flexible tube may not be completely restored to the original state, and the endoscope flexible tube may be deformed.

  Moreover, when the edge of the strip material of one spiral tube is caught between the strip materials of the other spiral tube on the opposite side of the two spiral tubes, the sliding resistance between the two spiral tubes increases. However, the smooth bending operation of the endoscope flexible tube may be impaired.

Japanese Patent Laid-Open No. 5-31065 (FIG. 3)

  An object of the present invention is to provide a flexible tube for an endoscope that can prevent deformation even when it is repeatedly bent and that can smoothly perform a bending operation, and an endoscope including the same. .

The object is achieved by the present inventions (1) to (8) below.
(1) A flexible tube for an endoscope having a tubular core material and an outer skin coated on the outer periphery of the core material,
The tubular core material is an inner spiral tube formed in a spiral shape by winding a belt-shaped material;
On the outer periphery of the inner spiral tube, an outer spiral tube formed in a spiral shape by winding a strip-like material in a direction opposite to the inner spiral tube;
A reticulated tube coated on the outer periphery of the outer spiral tube;
The flexible tube for an endoscope, wherein the width of the band-shaped member on the outer periphery of the inner spiral tube is smaller than the width of the band-shaped member on the inner periphery of the inner spiral tube.

  Thereby, when the flexible tube for an endoscope is extended from a bent state to a straight state, the force that pushes the strips between the two inner and outer spiral tubes separates the strips from each other. Therefore, it becomes difficult for the strip material of one spiral tube to enter between the strip materials of the other spiral tube. Therefore, even if the flexible tube for an endoscope is extended from a bent state, it is possible to prevent the strip material of the inner spiral tube from climbing over to the outer peripheral side of the outer spiral tube. Even if the bending of the flexible tube for a mirror is repeated, the deformation of the flexible tube for an endoscope is prevented. In addition, when the flexible tube for endoscope is bent, the strip material of one spiral tube is not easily caught between the strip materials of the other spiral tube on the opposite side of the two spiral tubes inside and outside. In addition, it is difficult for the strip material of one spiral tube to enter between the strip materials of the other spiral tube, and deformation of the flexible tube for endoscope is prevented even if the flexible tube for endoscope is repeatedly bent. Furthermore, the fact that the strip of one spiral tube is less likely to be caught between the strips of the other spiral tube on the opposite side of the two inner and outer spiral tubes leads to a reduction in sliding resistance between the two inner and outer spiral tubes. The bending operability of the endoscope flexible tube is improved.

  (2) The flexible tube for an endoscope according to the above (1), wherein the width of the band-shaped material on the inner periphery of the outer spiral tube is smaller than the width of the band-shaped material on the outer periphery of the outer spiral tube. .

  Thereby, the obtained flexible tube for endoscope can prevent the deformation | transformation by repetition of bending more reliably, and can make bending operation smoother.

(3) A flexible tube for an endoscope having a tubular core material and an outer skin coated on the outer periphery of the core material,
The tubular core material is an inner spiral tube formed in a spiral shape by winding a belt-shaped material;
On the outer periphery of the inner spiral tube, an outer spiral tube formed in a spiral shape by winding a strip-like material in a direction opposite to the inner spiral tube;
A reticulated tube coated on the outer periphery of the outer spiral tube;
The flexible tube for an endoscope, wherein the width of the band-shaped member on the inner periphery of the outer spiral tube is smaller than the width of the band-shaped member on the outer periphery of the outer spiral tube.

  Thereby, the obtained flexible tube for an endoscope can prevent deformation due to repeated bending, and can smoothly perform a bending operation.

  (4) The endoscope according to any one of (1) to (3), wherein at least one of the inner spiral tube and the outer spiral tube has an edge of a belt-like material tapered. Flexible tube.

  As a result, the width of the belt-like material on the outer periphery of the inner spiral tube is made smaller than the width of the belt-like material on the inner periphery of the inner spiral tube, or the width of the belt-like material on the inner periphery of the outer spiral tube is reduced to the outer spiral. It is possible to make the width smaller than the width of the belt-like material on the outer periphery of the tube by relatively simple processing.

  (5) The flexible tube for an endoscope according to (4), wherein a taper angle at a taper of the edge portion of the belt-shaped material is 5 to 30 °.

  Thereby, the deformation | transformation of the flexible tube for endoscopes by the bending of the flexible tube for endoscopes is prevented more reliably.

(6) When each of the inner spiral tube and the outer spiral tube has a maximum width of the strip-shaped material as A [mm] and a maximum thickness of the strip-shaped material as B [mm],
The flexible tube for an endoscope according to any one of (1) to (5), wherein B / A satisfies a relationship of 0.03 to 0.20.

  Accordingly, while maintaining both the strength and flexibility of the two inner and outer spiral tubes, the belt-like members of the two inner and outer spiral tubes are in contact with each other with a relatively large contact surface and are stably held parallel to each other. Can do. As a result, the flexible tube for an endoscope has excellent flexibility, and it is difficult for the strip material of one spiral tube to enter between the strip materials of the other spiral tube, so that deformation due to repeated bending is more reliable. Will be prevented.

(7) When each of the inner spiral tube and the outer spiral tube has a maximum width of the strip-shaped material as A [mm] and a spiral pitch as C [mm],
The flexible tube for an endoscope according to any one of (1) to (6), wherein C / A satisfies a relationship of 1.1 to 1.5.

  Thereby, the width of the strip of the other spiral tube can be made relatively large with respect to the interval between the strips of the one spiral tube while making the flexibility of the two inner and outer spiral tubes good. As a result, the flexible tube for an endoscope has excellent flexibility, but it is difficult for the strip material of one spiral tube to enter between the strip materials of the other spiral tube, and deformation due to repeated bending is difficult. It will be more reliably prevented.

  (8) An endoscope comprising the flexible tube for an endoscope according to any one of (1) to (7).

  As a result, it is possible to prevent the endoscope flexible tube from being deformed due to repeated bending of the endoscope flexible tube, and to obtain an endoscope that enables smooth bending operability.

  As described above, according to the present invention, it is possible to prevent deformation even when bending is repeated, and to obtain a flexible tube for an endoscope that enables a smooth bending operation.

  In addition, according to the present invention, there is provided an endoscope that can prevent deformation due to repeated bending of an endoscope flexible tube, and further enables a smooth bending operation of the endoscope flexible tube. Can be obtained.

  DESCRIPTION OF EMBODIMENTS Hereinafter, preferred embodiments of an endoscope flexible tube and an endoscope according to the present invention will be described in detail with reference to the accompanying drawings.

  FIG. 1 is an overall view showing an embodiment when the endoscope of the present invention is applied to an electronic endoscope (electronic scope), and FIG. 2 is an insertion portion flexible tube provided in the electronic endoscope shown in FIG. It is a fragmentary longitudinal cross-section of the part corresponding to the flexible tube. Hereinafter, in FIG. 1, the upper side is described as “base end” and the lower side is described as “tip”.

  As shown in FIG. 1, the electronic endoscope 10 includes a flexible insertion portion flexible tube 1 having flexibility (flexibility) and a bending portion connected to the distal end portion of the insertion portion flexible tube 1. 12, an operation unit 6 that is connected to the proximal end portion of the insertion portion flexible tube 1 and is gripped by an operator to operate the entire electronic endoscope 10, and a connection portion flexible tube 7 that is connected to the operation unit 6 And a light source insertion portion 8 connected to the distal end side of the connection portion flexible tube 7.

  The insertion portion flexible tube 1 and the connection portion flexible tube 7 are each a flexible tube for an endoscope in which the outer periphery of a (tubular) core material having a hollow portion is covered with an outer skin 3 (that is, the inner portion of the present invention). (Flexible tube for endoscope).

  The operation unit 6 is provided with operation knobs 61 and 62 on its side surface. When the operation knobs 61 and 62 are operated, a wire (not shown) disposed in the insertion portion flexible tube 1 is pulled, and the bending portion 12 is bent in four directions, and the directions can be changed. .

  An imaging element (CCD) (not shown) that captures a subject image at the observation site is provided inside the distal end portion of the bending portion 12, and an image signal connector 82 is provided at the distal end portion of the light source insertion portion 8. Yes. The image signal connector 82 is connected to a light source processor device (not shown) connected to a monitor device (not shown) via a cable. In addition, a light source connector 81 is installed at the tip of the light source insertion portion 8, and the light source connector 81 is connected to the light source processor device.

  The light emitted from the light source processor device is continuously arranged in the light source connector 81 and the light source insertion portion 8, the connection portion flexible tube 7, the operation portion 6, and the insertion portion flexible tube 1. Through the light guide (not shown), the observation site is irradiated from the tip of the bending portion 12 and illuminated. Such a light guide is configured by bundling a plurality of optical fibers made of, for example, quartz, multicomponent glass, plastic, or the like.

  The reflected light (subject image) from the observation site illuminated by the illumination light is imaged by the image sensor. The image sensor outputs an image signal corresponding to the captured subject image. This image signal is continuously arranged in the bending portion 12, the insertion portion flexible tube 1, the operation portion 6, and the connection portion flexible tube 7, and connects the image sensor and the image signal connector 82. The light is transmitted to the light source insertion portion 8 via an image signal cable (not shown).

  Then, predetermined processing (for example, signal processing, image processing, etc.) is performed in the light source insertion unit 8 and the light source processor device, and then input to the monitor device. In the monitor device, an image (electronic image) captured by the image sensor, that is, an endoscope monitor image of a moving image is displayed.

<Insertion section flexible tube 1>
As shown in FIG. 2, the insertion portion flexible tube 1 has a tubular core member 2 and an outer skin 3 that covers the outer periphery thereof. In the space 24 of the insertion portion flexible tube 1 (core material 2), for example, a long member (not shown) such as an optical fiber, an electric cable, a cable, or a tube is disposed.

  The core material 2 is composed of a double spiral tube 21 that is concentrically arranged inside and outside in the radial direction of the core material 2 and a mesh tube 22 that covers the outer periphery of the double spiral tube 21.

  As shown in FIGS. 2 and 3, the double spiral tube 21 includes an inner spiral tube 21 </ b> A and an outer spiral tube 21 </ b> B. The inner spiral tube 21A and the outer spiral tube 21B have opposite spiral winding directions. Thereby, when the proximal end portion of the insertion portion flexible tube 1 is twisted in the circumferential direction, the diameter of one spiral tube tends to increase and the diameter of the other spiral tube tends to decrease. As a result, the inner spiral tube 21A and the outer spiral tube 21B press each other against one twist in the circumferential direction at the proximal end of the insertion portion flexible tube 1, and the other twist The outer periphery of the outer spiral tube 21B is pressed against the inner periphery of the mesh tube 22, and the distal end portion of the insertion portion flexible tube 1 can reliably follow the twist of the proximal end portion. That is, good torque transmission is imparted to the insertion portion flexible tube 1.

  In the double spiral tube 21, the strips of the inner spiral tube 21 </ b> A and the outer spiral tube 21 </ b> B each have a taper whose width becomes narrower in the opposing direction of the inner and outer spiral tubes, as shown in FIG. 2. Is formed. As a result, the width of the strip material on the outer periphery of the inner spiral tube 21A is smaller than the width of the strip material on the inner periphery of the inner spiral tube 21A, and the width of the strip material on the inner periphery of the outer spiral tube 21B. Is smaller than the width of the belt-like material on the outer periphery of the outer spiral tube 21B.

  Here, based on FIG. 4 and FIG. 5, the operation of the taper when the insertion portion flexible tube 1 is bent or stretched will be described in comparison with a conventional endoscope flexible tube.

  FIG. 4 is a diagram showing a state when the insertion portion flexible tube 1 according to the present invention is bent or stretched, and FIG. 5 is a state when a conventional endoscope flexible tube is bent or stretched. FIG.

  In the insertion portion flexible tube 1 of the present invention, since the taper is formed, when the insertion portion flexible tube 1 is bent from the state shown in FIG. 4 (A) to the state shown in FIG. 4 (B). Furthermore, the edge of the strip of one spiral tube is less likely to be caught between the strips of the other spiral tube on the opposite side of the inner spiral tube 21A and the outer spiral tube 21B. Therefore, even when the insertion portion flexible tube 1 is extended from the state shown in FIG. 4B to the state shown in FIG. 4D, the strip material of one spiral tube is the same as the strip material of the other spiral tube. Difficult to get in between. As a result, even when the bending of the endoscope flexible tube is repeated, the belt-like material of the inner spiral tube 21A does not climb over the outer peripheral side of the outer spiral tube 21B, thereby preventing deformation of the endoscope flexible tube. Is done.

  When the insertion portion flexible tube 1 is extended from the state shown in FIG. 4 (B) to the state shown in FIG. 4 (D), as shown in FIG. And the taper of the strip material of the outer spiral tube 21B are pressed against each other, so that they slide with each other, and a force in the separation direction is generated between the strip materials. That is, the force that presses the taper of the strip material of the inner spiral tube 21A and the taper of the strip material of the outer spiral tube 21B is converted into a force in a direction that separates the strip materials. Such a force makes it difficult for the strips of one spiral tube to enter between the strips of the other spiral tube, so that the deformation of the insertion portion flexible tube 1 is also prevented in this respect.

  Further, since the strip material of one spiral tube is not easily caught between the strip materials of the other spiral tube on the opposite side of the two spiral tubes 21A and 21B, the sliding between the two spiral tubes 21A and 21B is performed. The resistance is reduced, and the insertion portion flexible tube 1 enables a smooth bending operation.

  On the other hand, in the conventional flexible tube 101 for endoscope, the edge of the strip of the inner spiral tube 121A and the strip of the spiral tube 121B on the outer side are opposite to the inner and outer spiral tubes 121A and 121B. Since the edges are relatively sharp and angular, when the flexible tube 101 for endoscope is bent from the state shown in FIG. 5A to the state shown in FIG. The edge of the strip of the spiral tube 121A and the edge of the strip of the outer spiral tube 121B are easily caught. When the endoscope flexible tube 101 is extended from the state shown in FIG. 5 (B) to the state shown in FIG. 5 (C) with these being caught, the edge of the strip-like material of the inner spiral tube 121A The edges of the strips of the outer spiral tube 121B may be pressed against each other, and the strips of one spiral tube may enter between the strips of the other spiral tube. Furthermore, the band-shaped material of the inner spiral tube 21A gets over the outer peripheral side of the outer spiral tube 21B, and as a result, the endoscope flexible tube 101 may be deformed.

  Thus, the insertion portion flexible tube 1 of the present invention can prevent deformation even when it is repeatedly bent, and further enables a smooth bending operation as compared with the conventional one (having excellent bending operability). Is.

  The inner spiral tube 21A is formed by spirally winding a strip-like material at a predetermined pitch. Further, the inner diameter of the inner spiral tube 21A is set to be substantially uniform over the entire length thereof. Although it does not specifically limit as a constituent material of 21 A of spiral tubes, For example, stainless steel, a copper alloy, etc. are used preferably.

  Further, as shown in FIG. 2, the strip of the inner spiral tube 21 </ b> A is narrowed in a section passing through the axis 11 in a direction facing the strip of the outer spiral tube 21 </ b> B, that is, toward the outer periphery. Thus, a taper is formed. In other words, the edge of the strip of the inner spiral tube 21A on the side facing the outer spiral tube 21B is an inclined surface. Thereby, as described above, the insertion portion flexible tube 1 can prevent deformation even if it is repeatedly bent, and has excellent bending operability. The taper can be formed in the inner spiral tube 21A by a relatively simple process.

  The taper angle (θ shown in FIG. 2) of the taper is preferably 5 to 30 °, and more preferably 10 to 20 °. Thereby, the insertion part flexible tube 1 is more reliably prevented from being deformed by repeated bending. If the taper angle is less than the lower limit value, the strip of the inner spiral tube 21A has a relatively angular shape on the side facing the outer spiral tube 21B. Depending on the thickness and width, the width of the strip of the outer spiral tube 21B, the spiral pitch, and the like, the edge of the strip of the inner spiral tube 21A may be easily caught between the strips of the outer spiral tube 21B. There is. On the other hand, when the taper angle exceeds the upper limit value, the side portion of the strip material of the inner spiral tube 21A has a relatively sharp shape, so the thickness and width of the strip material of the inner spiral tube 21A, the outer spiral Depending on the width of the strip of the tube 21B, the spiral pitch, etc., the edge of the strip of the inner spiral tube 21A may easily enter between the strips of the outer spiral tube 21B.

  The outer spiral tube 21B is formed by spirally winding a belt-like material at a predetermined pitch on the outer periphery of the aforementioned inner spiral tube 21A. The winding direction of the strip of the outer spiral tube 21B is opposite to the winding direction of the strip of the inner spiral tube 21A. The constituent material of the outer spiral tube 21B is not particularly limited, as is the case with the inner spiral tube 21A. For example, stainless steel, copper alloy, and the like are preferably used.

  Further, as shown in FIG. 2, the strip of the outer spiral tube 21 </ b> B has a narrow cross section on the surface passing through the axis 11 in a direction facing the strip of the inner spiral tube 21 </ b> A, that is, toward the inner periphery. A taper is formed so as to be. In other words, the edge of the strip of the outer spiral tube 21B on the side facing the inner spiral tube 21A is an inclined surface. Thereby, as described above, the insertion portion flexible tube 1 can prevent deformation even if it is repeatedly bent, and has excellent bending operability. The taper can be formed in the outer spiral tube 21B by a relatively simple process.

  The taper angle of the taper is preferably 5 to 30 °, and more preferably 10 to 20 °. Thereby, the insertion part flexible tube 1 is more reliably prevented from being deformed by repeated bending. If the taper angle is less than the lower limit value, the strip of the outer spiral tube 21B has a relatively angular shape on the side facing the inner spiral tube 21A. Depending on the thickness and width, the width of the strip of the inner spiral tube 21A, the spiral pitch, and the like, the edge of the strip of the outer spiral tube 21B may be easily caught between the strips of the inner spiral tube 21A. There is. On the other hand, when the taper angle exceeds the upper limit value, the side portion of the strip material of the outer spiral tube 21B has a relatively sharp shape, so the thickness and width of the strip material of the outer spiral tube 21B, the inner spiral Depending on the width of the strip of the tube 21A, the spiral pitch, and the like, the edge of the strip of the outer spiral tube 21B may be easily caught between the strips of the inner spiral tube 21A.

  Each of the strips of the inner spiral tube 21A and the outer spiral tube 21B as described above has a B / A of 0 when the maximum width is A [mm] and the maximum thickness is B [mm]. It is preferable to satisfy the relationship of 0.03 to 0.20, and it is more preferable to satisfy the relationship of 0.05 to 0.15.

  As a result, the strips of the inner spiral tube 21A and the outer spiral tube 21B try to be in contact with each other with a relatively large contact surface and to be held in parallel while achieving both strength and flexibility. Therefore, the insertion portion flexible tube 1 has excellent flexibility and is difficult to be deformed, and one of the inner and outer spiral tubes 21A and 21B has a strip-like material as the other spiral tube. It is possible to make it more difficult to enter between the belt-like materials. As a result, the insertion portion flexible tube 1 has excellent flexibility and is more reliably prevented from being deformed by repeated bending. Here, the maximum width of the strip-shaped material is the width of the strip-shaped material in the inner periphery or the vicinity thereof in the inner spiral tube 21A, and the strip width in the outer periphery or the vicinity thereof in the outer spiral tube 21B. The width of the material.

  The inner spiral tube 21A and the outer spiral tube 21B have a C / A of 1.1 to 1.5 when the maximum width of the belt-like material is A [mm] and the spiral pitch is C [mm]. It is preferable to satisfy the following relationship, and it is more preferable to satisfy the relationship of 1.2 to 1.4.

  Accordingly, while the flexibility of the inner spiral tube 21A and the outer spiral tube 21B is improved, the width of the strip material of the other spiral tube is relatively set with respect to the interval between the strip materials of one spiral tube. Can be bigger. Therefore, the operation portion flexible tube 1 has excellent flexibility, and it is difficult for the strip material of one spiral tube to enter between the strip materials of the other spiral tube, so that deformation due to repeated bending is more reliably performed. Is prevented.

  The inner spiral tube 21A and the outer spiral tube 21B may have the same or different pitch. Further, the strip material of the inner spiral tube 21A and the strip material of the outer spiral tube 21B may have the same or different width, thickness, and taper angle.

  In addition, if the taper as described above is provided on any one of the two inner and outer spiral tubes 21A and 21B, the effect of the present invention can be exhibited, but the inner and outer spiral tubes 21A and 21B can be exhibited. It is preferable that the taper is formed on both. Thereby, deformation of the endoscope flexible tube due to repeated bending of the endoscope flexible tube is more reliably prevented, and the bending operability is further improved.

  Further, the shape of the strips of the inner and outer spiral tubes 21A and 21B is such that the section of the strip in the plane passing through the axis of the inner and outer spiral tubes 21A and 21B is continuous toward the opposing direction of the two inner and outer spiral tubes. If the width is narrow, the shape of the cross section is not limited to the tapered shape described above. In other words, the width of the band-shaped material on the outer periphery of the inner spiral tube 21A only needs to be smaller than the width of the band-shaped material on the inner periphery of the inner spiral tube 21A, and the inner periphery of the outer spiral tube 21B. The width | variety of the strip | belt-shaped material in (2) should just be smaller than the width | variety of the strip | belt-shaped material in the outer periphery of the outer side spiral tube 21B. For example, the surface formed by the edge in the width direction of the strip-shaped material of the inner spiral tube 21A or the outer spiral tube 21B may be a curved surface.

  The mesh tube 22 is formed by arranging a plurality of thin wires 23 made of metal or nonmetal. As a constituent material of the thin wire 23, for example, stainless steel, copper alloy or the like is preferably used. Further, at least one of the fine wires 23 constituting the mesh tube may be covered with a resin material. The reticulated tube 22 may be formed by double thin wires 23 stacked in the circumferential direction of the spiral tube, or may be formed by knitting a plurality of thin wires 23 one by one.

  Further, inside the core material 2 (insertion section flexible tube 1), for example, molybdenum disulfide, boron nitride (BN), tetrafluoroethylene polymer (fluorine resin), graphite, fluorocarbon ((CF ) A solid lubricant such as n) is disposed. This solid lubricant is arranged around the long member as described above. Thereby, the sliding resistance (friction resistance) between each elongate member or between each elongate member and the core material 2 can be made small. For this reason, when the insertion portion flexible tube 1 (insertion portion flexible tube 1 and bending portion 12) is bent, the movement of each long member in the longitudinal direction (axial direction) of the core member 2 is smoothly performed. The bending resistance is small. Further, pulling, compression, and buckling of the optical fiber constituting the light guide are suppressed, and as a result, damage, breakage, and the like can be effectively prevented.

  An outer skin 3 is coated on the outer periphery of the core material 2. The outer skin 3 is a part that directly contacts the inner wall of a tubular organ such as the digestive tract, and has a function of preventing body fluid or the like from entering the insertion portion flexible tube 1. The outer skin 3 may be composed of a single layer or a plurality of layers.

  The constituent material of the outer skin 3 is not particularly limited, and examples thereof include polyolefins such as polyvinyl chloride, polyethylene, polypropylene, and ethylene-vinyl acetate copolymer, polyesters such as polyamide, polyethylene terephthalate (PET), polybutylene terephthalate, and polyurethane. , Polystyrene resins, fluorine resins such as polytetrafluoroethylene, ethylene-tetrafluoroethylene copolymer, various flexible resins such as polyimide, polyurethane, polyester, polyolefin, polyamide, polystyrene Fluorine-based thermoplastic elastomers, various elastomers such as silicone rubber, fluororubber, and latex rubber can be used, and one or more of these can be used in combination. Among these, it is particularly preferable to use a polyurethane-based thermoplastic elastomer, a polyolefin-based thermoplastic elastomer, or a polyester-based thermoplastic elastomer. By using these, the adhesion with the mesh tube 22 is improved.

  When using what coated at least 1 of the thin wires 23 which comprise the reticular tube 22 with a resin material, at least one part of this coated resin material (coating layer) fuse | melts and it is in the outer skin 3 Bond (weld).

  Such an outer skin 3 has chemical resistance and heat resistance because it is exposed to chemicals such as various disinfectants and high temperature and pressure during repeated disinfection and sterilization treatment, and the body cavity is caused by friction. In order to prevent damage to the internal tissue, a material having flexibility (flexibility) is preferably used as a main material.

  The average thickness of the outer skin 3 as described above can protect the core material 2 and the long members disposed in the core material 2 from liquids such as body fluids, and the flexibility of the insertion portion flexible tube 1. If not hindered, it is not particularly limited, but is preferably about 0.08 to 0.9 mm, more preferably about 0.1 to 0.8 mm, and about 0.3 to 0.5 mm. Further preferred.

  Further, the thickness of the outer skin 3 may have a portion that varies along the longitudinal direction, but is preferably substantially constant. Thereby, the bending operativity at the time of inserting the insertion part flexible tube 1 in a body cavity improves more, and a patient's burden is also reduced more.

  In addition, in the material of the outer skin 3 (outer material), for example, a plasticizer, an inorganic filler, a pigment, various stabilizers (antioxidant, light stabilizer, antistatic agent, antiblocking agent, lubricant) ), Various additives such as an X-ray contrast agent may be blended (mixed).

  The insertion portion flexible tube 1 as described above can be manufactured by, for example, extruding the material of the outer skin layer from the extrusion port and covering the core material with an extruder.

  Further, the thickness of the layer can be adjusted by adjusting the discharge amount of the constituent material of the layer from the extrusion port and the drawing speed of the core material.

  In addition, the insertion portion flexible tube 1 is manufactured, for example, by separately manufacturing the outer skin 3 as a hollow tube (tube), covering the core material 2 and then heat-sealing by heating or the like. Also good.

  Although the material temperature at the time of extrusion molding is not particularly limited, it is preferably about 130 to 220 ° C, more preferably about 165 to 205 ° C. When the material temperature at the time of extrusion molding is in such a temperature range, the outer skin material is excellent in molding processability to the outer skin 3. For this reason, the uniformity of the thickness of the outer skin 3 is improved. The material temperature may be different depending on the material of each layer.

  The endoscope flexible tube and the endoscope of the present invention have been described above, but the present invention is not limited to this, and the configuration of each member (each part) is an arbitrary one having the same function. Can be substituted, or any configuration can be added.

  In each of the above embodiments, the insertion portion flexible tube has been described as a representative endoscope flexible tube, but the endoscope flexible tube of the present invention can be applied to a connection portion flexible tube, In addition, although an electronic endoscope (electronic scope) has been described as a representative endoscope, it goes without saying that the endoscope of the present invention can be applied to an optical endoscope (fiberscope type endoscope). Yes.

  Moreover, although each said embodiment demonstrated what was used for a medical endoscope, the flexible tube for endoscopes of this invention is applied to the endoscope used for industrial (industrial use). You can also

Next, specific examples of the present invention will be described.
1. Production of flexible tube for endoscope (Example 1)
First, a cross section as shown in FIG. 2 is tapered with a taper angle of 15 °, and a stainless steel strip having a maximum width of 3.0 mm and a maximum thickness of 0.25 mm is wound at a pitch of 4.0 mm to obtain an outer diameter. A 9 mm spiral tube and an outer diameter 8.5 mm spiral tube were respectively prepared. At this time, as shown in FIG. 2, the strip of the spiral tube having an outer diameter of 9 mm is tapered on the inner peripheral side, and the spiral tube having an outer diameter of 8.5 mm is tapered on the outer peripheral side.

  Next, a spiral tube with an outer diameter of 9 mm was set as the outside, and a spiral tube with an outer diameter of 8.5 mm was set as the inside, and these spiral tubes were doubled to obtain a double spiral tube. And the outer peripheral part of this double helical tube was coat | covered with the reticulated tube which arranged the stainless steel thin wire with a diameter of 0.08 mm, and the core material was obtained.

  At this time, the maximum width (A) and the maximum thickness (B) of the strips of the outer spiral tube and the inner spiral tube were such that B / A was 0.08. In addition, the maximum width (A) of the strips of the outer spiral tube and the inner spiral tube and the spiral pitch (C) have a relationship of C / A of 1.33.

On the other hand, polyurethane (TPU) was prepared, and an outer shell made of TPU was formed on the outer periphery of the above-described core material by extrusion molding to produce a flexible tube for an endoscope. At this time, the average thickness of the outer skin was 0.45 mm, and the length of the endoscope flexible tube was 1 m.
In addition, the temperature of the material at the time of extrusion molding was 190 degreeC.

(Examples 2 and 3)
A flexible tube for an endoscope was manufactured in the same manner as in Example 1 except that the thickness of the strip material for forming the inner and outer spiral tubes was as shown in Table 1.

  At this time, the maximum width (A) and the maximum thickness (B) of the strips of the outer spiral tube and the inner spiral tube were such that B / A was as shown in Table 1.

(Examples 4 and 5)
A flexible tube for an endoscope was manufactured in the same manner as in Example 1 except that the pitches of the inner and outer spiral tubes were as shown in Table 1.

  At this time, the maximum width (A) and the pitch (C) of the strips of the outer spiral tube and the inner spiral tube were in the relationship as shown in Table 1.

(Examples 6 and 7)
A flexible tube for an endoscope was manufactured in the same manner as in Example 1 except that the taper angles of the strips of the inner and outer spiral tubes were as shown in Table 1.

(Example 8)
An endoscope similar to the first embodiment except that the taper angle of the inner spiral tube strip is as shown in Table 1 and the outer spiral tube strip has a rectangular cross section without a taper. A flexible tube was prepared.

(Comparative example)
A flexible tube for an endoscope was manufactured in the same manner as in Example 1 except that the strips of the inner spiral tube and the outer spiral tube were not provided with a taper and had a rectangular cross section.

2. Characteristic Evaluation of Endoscopic Flexible Tube [2.1] Durability Test The endurance test was performed on the endoscope flexible tube produced in each example and each comparative example by the following method.

  In the durability test, 10 flexible tubes for each endoscope were prepared, and the operation of supporting the both ends of the flexible tubes for the endoscope one by one and bending them 90 ° was repeated 1000 times. The degree was visually observed and evaluated according to the following four-stage criteria.

A: No change in appearance.
○: Some deformation of the appearance is recognized, but there is no problem at all in use.
(Triangle | delta): Although a deformation | transformation of an external appearance is recognized, it is a deformation | transformation of the level which hardly has a problem in use.
X: Deformation of the appearance is recognized so as to cause a problem in use.

[2.2] Bending operability test In the bending operability test, ten flexible tubes for each endoscope were prepared, and each one was bent 90 ° while supporting both ends of the flexible tube for endoscopes. Later, a straightening operation was performed, and the smoothness at that time was evaluated according to the following three-stage criteria.

A: It can be bent and extended very smoothly and is ideal for use as a flexible tube for endoscopes.
○: It can be bent and stretched smoothly and is suitable for use as a flexible tube for endoscopes.
Δ: Feeling a slight catch when bent or stretched, but no problem in use.
X: Feels caught when bent or stretched and lacks smoothness.

[2.3] Flexibility test In the flexibility test, 10 flexible tubes for each endoscope were prepared, and 10 flexible tubes for each example and comparative example were collected together. A force was applied to both ends so that the both ends were supported and bent at 90 °, and the flexibility at that time was evaluated according to the following four criteria.

(Double-circle): It can be bend | folded at 90 degrees and has very outstanding flexibility.
○: It can be bent up to approximately 90 ° and has excellent flexibility.
(Triangle | delta): It was able to bend a little.
X: Almost no bending was possible.
These results are shown in Table 2.

  As is clear from Table 2, none of the flexible tubes for an endoscope of the present invention was found to be unsuitable for use as an endoscope, and excellent flexibility and smoothness. It can be bent and stretched to provide excellent bending operability.

  On the other hand, the flexible tube for an endoscope of the comparative example was inferior in performance to that of the present example. In other words, deformation that was not suitable for use as an endoscope was observed, and the film was not smooth when folded or stretched, resulting in poor bending operability. This is presumed to be due to the fact that the edges of the inner spiral tube and the outer spiral tube of the outer spiral tube are squared, and the edges are caught.

1 is an overall view showing an embodiment when an endoscope of the present invention is applied to an electronic endoscope (electronic scope). It is an enlarged view which shows the longitudinal cross-section of the insertion part flexible tube (flexible tube for endoscopes of this invention) with which the electronic endoscope shown in FIG. 1 is provided. It is a figure which shows the inner side spiral tube and the outer side spiral tube with which the insertion part flexible tube shown in FIG. 2 was equipped. It is a figure for demonstrating a state when the flexible tube for endoscopes shown in FIG. 2 is bent repeatedly. It is a figure for demonstrating a state when the conventional flexible tube for endoscopes is bent repeatedly.

Explanation of symbols

10 Electronic Endoscope 1 Insertion Section Flexible Tube (Flexible Tube for Endoscope of the Present Invention)
DESCRIPTION OF SYMBOLS 11 Axis 12 Curved part 2 Core material 21 Double spiral tube 21A Inner spiral tube 21B Outer spiral tube 22 Reticulated tube 23 Fine wire 24 Space 3 Outer skin 6 Operation part 61, 62 Operation knob 7 Connection part flexible tube 8 Light source insertion Part 81 Light source connector 82 Image signal connector 101 Endoscopic flexible tube 121A Spiral tube 121B Spiral tube

Claims (8)

A flexible tube for an endoscope having a tubular core material and an outer skin coated on the outer periphery of the core material,
The tubular core material is an inner spiral tube formed in a spiral shape by winding a band-shaped material;
On the outer periphery of the inner spiral tube, an outer spiral tube formed in a spiral shape by winding a strip-like material in a direction opposite to the inner spiral tube;
A reticulated tube coated on the outer periphery of the outer spiral tube;
The flexible tube for an endoscope, wherein the width of the band-shaped member on the outer periphery of the inner spiral tube is smaller than the width of the band-shaped member on the inner periphery of the inner spiral tube.   The flexible tube for an endoscope according to claim 1, wherein a width of the belt-shaped member on the inner periphery of the outer spiral tube is smaller than a width of the belt-shaped material on the outer periphery of the outer spiral tube. A flexible tube for an endoscope having a tubular core material and an outer skin coated on the outer periphery of the core material,
The tubular core material is an inner spiral tube formed in a spiral shape by winding a belt-shaped material;
On the outer periphery of the inner spiral tube, an outer spiral tube formed in a spiral shape by winding a strip-like material in a direction opposite to the inner spiral tube;
A reticulated tube coated on the outer periphery of the outer spiral tube;
The flexible tube for an endoscope, wherein the width of the band-shaped member on the inner periphery of the outer spiral tube is smaller than the width of the band-shaped member on the outer periphery of the outer spiral tube.   The flexible tube for an endoscope according to any one of claims 1 to 3, wherein at least one of the inner spiral tube and the outer spiral tube has an edge portion of a belt-like material tapered.   The flexible tube for an endoscope according to claim 4, wherein a taper angle of a taper of the edge portion of the belt-shaped material is 5 to 30 °. When each of the inner spiral tube and the outer spiral tube has a maximum width of the strip-shaped material as A [mm] and a maximum thickness of the strip-shaped material as B [mm],
The flexible tube for an endoscope according to claim 1, wherein B / A satisfies a relationship of 0.03 to 0.20. Each of the inner spiral tube and the outer spiral tube has a maximum width of a strip-shaped material of A [mm] and a spiral pitch of C [mm],
The flexible tube for an endoscope according to claim 1, wherein C / A satisfies a relationship of 1.1 to 1.5.   An endoscope comprising the flexible tube for an endoscope according to any one of claims 1 to 7.

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