JP2012200355A - Flexible tube for endoscope and method for assembling flexible tube for endoscope - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a flexible tube for an endoscope, which solves a problem of a conventional flexible tube that an outer sheath buckles when the flexible tube is bent frequently.SOLUTION: A spiral tube 74 includes a spring structure. The outer sheath 80 is arranged on the spiral tube 74 while the spiral tube 74 is contracted in the axial direction. By doing so, the outer sheath 80 can be expanded in a predetermined amount in the axial direction of the outer sheath 80 by elastic restoration force of the spiral tube 74. By adjusting the contraction amount of the spiral tube 74, the expansion amount of the outer sheath 80 can be set between 5-15% with respect to the natural length. Alternatively, the spiral tube 74 is made of a shape memory alloy that contracts in the axial direction of the spiral tube 74 when heated. By covering the spiral tube 74 with the outer sheath 80 at a temperature of ≥150°C, the spiral tube 74 contracts in the axial direction by shape restoration effect due to the temperature. After that, the temperature is lowered to or below the shape restoration temperature to expand the outer sheath 80 in the axial direction of the outer sheath 80 and in a predetermined amount by expansion force of the spiral tube 74.

Description

  The present invention relates to an endoscope flexible tube and an endoscope flexible tube assembling method, and more particularly, an endoscope flexible tube having a three-layer structure including a screw tube, a net, and an outer shell, and an endoscope flexible tube. Relates to the assembly method.

  In the medical field, medical diagnosis using an endoscope is widely performed. In particular, an imaging element such as a CCD is incorporated at the distal end of the insertion portion of the endoscope that is inserted into the body cavity, and an image inside the body cavity is taken, signal processing is performed by the processor device, and the image is displayed on the monitor. The doctor observes and uses it for diagnosis, or inserts a treatment tool from a channel for inserting the treatment tool to perform treatment such as polyp excision.

  The endoscope includes a hand operation unit that is grasped and operated by an operator, an insertion unit that is connected to the hand operation unit and inserted into a body cavity and the like, and a light source device and a processor device that are connected to the hand operation unit. And a universal cable to be connected. In addition, the insertion portion includes a flexible tube (also referred to as a soft portion), a bending portion, and a hard tip portion in order from the hand operation portion.

  The flexible tube includes a screw tube, a net that covers the outer peripheral surface of the screw tube, and a resin outer skin that covers the outer peripheral surface of the net. Then, the net plays a role as a rigid reinforcement of the flexible tube by joining the net and the inner peripheral surface of the outer skin.

  A net is formed by crossing a large number of fine wires and knitting them into a mesh shape. As the fine wires, metal fibers such as stainless steel or brass are generally used.

  However, even if the metal net and the resin outer shell are bonded with an adhesive or the like, the metal and the resin are essentially difficult to bond, so the bond between the net and the outer shell decreases over time. .

  In the flexible tube, when the bondability between the net and the outer skin is lowered, when the flexible tube is bent, the outer skin located on the inner peripheral surface of the bending portion is peeled off from the net and buckling occurs. If buckling occurs, the rigidity of the flexible tube in the axial direction decreases, and the endoscope may become unusable.

  For example, Patent Documents 1 and 2 disclose techniques for improving the bondability between the net and the outer skin. In Patent Document 1, it is disclosed to bond (join) a mesh-shaped net formed by knitting a fibrous material and an outer skin with an adhesive interposed therebetween. Thus, it is said that by interposing the adhesive instead of the adhesive, it is possible to prevent the bondability between the net and the outer skin from being lowered while preventing the curing by the adhesive.

  In Patent Document 2, fibers made of a thermoplastic resin are wound around at least one metal wire of a metal wire bundle knitting a net, and the fiber made of a thermoplastic resin is melted to form a net and an outer skin. Adhesion is disclosed. Thereby, since the wound fiber and the resin-made outer skin are joined, it is said that jointability can be improved rather than joining with a metal net | network and the resin-made outer skin.

  However, in either case of Patent Documents 1 and 2, the problem that the net and the outer skin are easily separated due to the bending of the flexible tube cannot be sufficiently solved.

  From such a background, as described in Patent Document 3, the applicant has proposed that a net is knitted with metal fibers attached with a release agent and resin fibers attached with an adhesive. As a result, the metal fiber is not bonded to the outer skin with the release agent attached, and only the resin fiber to which the adhesive is attached can be bonded to the outer skin, so that the bonding force between the net and the outer skin can be significantly improved. It is said that.

JP 59-137030 A Japanese Patent Laid-Open No. 61-256085 JP 2009-213775 A

  However, even the flexible tube for an endoscope of Patent Document 3 cannot be said to essentially solve the decrease in the connectivity between the net and the outer skin when used for a long time, and further improvement is desired.

  The present invention has been made in view of such circumstances. An endoscope flexible tube and an endoscope flexible tube that can solve the conventional problem that the outer skin buckles even if the flexible tube is bent frequently. An object is to provide a method for assembling a pipe.

  In order to achieve the above object, the present invention provides an inner surface in which an outer peripheral surface of a screw tube formed by spirally winding a belt-like plate is covered with a net, and an outer peripheral surface of the net is covered with a resin outer skin. A flexible tube for an endoscope, wherein the outer skin is attached to the screw tube or the net in a state where the outer skin is extended by a predetermined amount in the axial direction of the outer skin. To do.

  In order to achieve the above object, the present invention provides an inner surface in which an outer peripheral surface of a screw tube formed by spirally winding a belt-like plate is covered with a net, and an outer peripheral surface of the net is covered with a resin outer skin. In the method of assembling a flexible tube for an endoscope, the outer skin is attached to the screw tube or the net in a state where the outer skin is extended by a predetermined amount in the axial direction of the outer skin. Provide a method.

  In the flexible tube for an endoscope of the present invention, the outer skin is attached to the screw tube in a state where the screw tube is contracted in the axial direction of the screw tube, and the outer skin is caused by the elastic restoring force of the screw tube. It is preferable to extend a predetermined amount in the axial direction of the outer skin.

  In the method for assembling the flexible tube for an endoscope of the present invention, the outer skin is attached to the screw tube in a state where the screw tube is contracted in the axial direction of the screw tube, and the elastic restoring force of the screw tube is used. It is preferable to extend the outer skin by a predetermined amount in the axial direction of the outer skin.

  In the flexible tube for an endoscope of the present invention, the screw tube is made of a shape memory alloy that heat-shrinks in the axial direction of the screw tube, and the outer cover is formed on the screw tube at a temperature of 150 ° C. or more. As a result, the screw tube is contracted in the axial direction by the shape recovery effect, and thereafter, the outer skin is extended by a predetermined amount in the axial direction of the outer skin due to the extension force of the screw tube by being below the shape recovery temperature. It is preferable.

  In the method for assembling the flexible tube for an endoscope of the present invention, the screw tube is made of a shape memory alloy that heat-shrinks in the axial direction of the screw tube, and the outer cover is formed on the screw tube at a temperature of 150 ° C. or more. By doing so, the screw tube is contracted in the axial direction by the shape recovery effect, and then the shape of the outer tube is extended by a predetermined amount in the axial direction of the outer shell due to the extension force of the screw tube by being below the shape recovery temperature. It is preferable to do.

  In the flexible tube for an endoscope of the present invention, a shape memory alloy member that is heated and shrunk in the axial direction is inserted and disposed inside or outside the screw tube, and the outer skin is placed in the screw tube at a temperature of 150 ° C. or more. The shape memory alloy member is contracted in the axial direction by a shape recovery effect by covering molding, and then the shape memory temperature is set to a temperature equal to or lower than the shape recovery temperature. It is preferable to extend a predetermined amount in the axial direction of the outer skin.

  According to the method for assembling the flexible tube for an endoscope of the present invention, a shape memory alloy member that is heated and contracted in the axial direction is inserted and disposed inside or outside the screw tube, and the outer skin is placed on the screw tube at 150 ° C. or more. The shape memory alloy member is contracted by the shape recovery effect in the axial direction by covering molding at a temperature of, and then the shape recovery temperature or less, by the extension force of the shape memory alloy member, It is preferable to extend the outer skin by a predetermined amount in the axial direction of the outer skin.

  In the flexible tube for an endoscope of the present invention, it is preferable that the outer skin is extended by a predetermined amount in the axial direction of the outer skin by an extension force of an elastic member inserted into the flexible tube for endoscope.

  In the method of assembling an endoscope flexible tube according to the present invention, the elastic member is contracted and inserted into the endoscope flexible tube, and the outer skin is moved in the axial direction of the outer skin by the extension force of the elastic member. It is preferable to extend a predetermined amount.

  The elastic member of the flexible tube for an endoscope of the present invention is a contact coil spring through which a wire for bending the bending portion connected to the distal end portion of the flexible tube for an endoscope is inserted. Is preferred.

  In the method for assembling an endoscope flexible tube according to the present invention, the elastic member is an adhesive coil into which a wire for bending the bending portion connected to the distal end portion of the endoscope flexible tube is inserted. A spring is preferred.

  In the flexible tube for an endoscope of the present invention, it is preferable that the elongation rate of the outer skin is 5 to 15% with respect to the natural length.

  In the assembling method of the flexible tube for an endoscope of the present invention, it is preferable that the elongation rate of the outer skin is 5 to 15% with respect to the natural length.

  When the flexible tube is bent into a curved shape, the inner portion of the outer shell of the curved flexible tube is subjected to stress that tends to shrink toward the center point of the curve. Therefore, when the flexible tube for an endoscope is configured with the outer skin extending in advance in the axial direction of the outer skin, and the tensile force is set to be equal to or greater than the assumed maximum value of the stress, the outer skin is curved. Even so, buckling does not occur in the inner part. In addition, by attaching the outer skin to the screw tube in a state where the outer skin is stretched by 5 to 15%, it is also optimal from both the aspects of the expansion and shrinkage of the resin of the outer skin.

  Therefore, according to the present invention, even if the flexible tube is curved, the outer skin does not peel off from the screw tube and buckling does not occur, so that the service life of the flexible tube is extended.

  According to the endoscope flexible tube and the endoscope flexible tube assembly method of the present invention, it is possible to solve the conventional problem that the flexible tube is buckled even if the flexible tube is bent frequently. it can.

External view showing overall configuration of endoscope according to embodiment The perspective view which showed the end surface of the front-end | tip hard part of the insertion part shown in FIG. Sectional view of the bending portion of the insertion portion shown in FIG. Partially cutaway view of the flexible tube shown in FIG. Enlarged view of the main part of a curved flexible tube Explanatory drawing which showed typically the 1st example of the assembly method of the flexible tube for endoscopes Explanatory drawing which showed typically the 2nd example of the assembly method of the flexible tube for endoscopes Explanatory drawing which showed typically the 3rd example of the assembly method of the flexible tube for endoscopes

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

  FIG. 1 is an external view showing an overall configuration of an endoscope 10 according to an embodiment. The endoscope 10 shown in FIG. 1 includes a hand operation unit 12 and an insertion unit 14 provided continuously to the hand operation unit 12. The surgeon grasps the hand operation unit 12 and performs observation by inserting the insertion unit 14 into the body of the subject.

  A universal cable 16 is connected to the hand operation unit 12, and a light guide (LG) connector (not shown) is provided at the tip of the universal cable 16. The LG connector is detachably connected to a light source device (not shown), and illumination light is sent from the light source device to illumination optical systems 52 and 52 disposed at the distal end hard portion 44 of the insertion portion 14 in FIG. In addition, an electrical connector is connected to the LG connector via a cable, and the electrical connector is detachably coupled to a processor (not shown).

  1 is provided with an air / water feed button 26, a suction button 28, and a shutter button 30 in parallel, and a pair of angle knobs 34, 34.

  Furthermore, the hand operation section 12 is provided with a forceps insertion section 38, and the forceps insertion section 38 is communicated with a forceps port 56 of the distal end hard section 44 of FIG. 2 via a forceps channel (not shown). Therefore, by inserting an endoscope treatment tool (not shown) such as forceps from the forceps insertion portion 38, the endoscope treatment tool can be led out from the forceps port 56.

  On the other hand, as shown in FIG. 1, the insertion portion 14 includes a flexible tube 40 whose proximal end is connected to the hand operating portion 12, a bending portion 42 whose proximal end is connected to the distal end of the flexible tube 40, It consists of the front-end | tip hard part 44 by which the base end part was connected to the front-end | tip part of the part 42. FIG.

  An observation optical system (observation lens) 50, illumination optical systems (illumination lenses) 52, 52, an air / water supply nozzle 54, and a forceps port 56 are located at predetermined positions on the distal end surface 45 of the distal end rigid portion 44 shown in FIG. Is provided. A CCD (not shown) is disposed behind the observation optical system 50, and a signal line (not shown) is connected to a substrate that supports the CCD. The signal line is inserted through the insertion section 14, the hand operating section 12, the universal cable 16 and the like of FIG. 1 to extend to the electrical connector described above, and is connected to the processor. Therefore, the observation image captured by the observation optical system 50 is formed on the light receiving surface of the CCD and converted into an electric signal. This electric signal is output to the processor via the signal line and converted into a video signal. As a result, the observation image is displayed on the monitor connected to the processor.

  The illumination optical systems 52 and 52 are provided adjacent to the observation optical system 50 and are arranged on both sides of the observation optical system 50 as necessary. An exit end of a light guide (not shown) is disposed behind the illumination optical system 52. This light guide is inserted through the insertion section 14, the hand operating section 12, and the universal cable 16 of FIG. 1, and the incident end of the light guide is disposed in the LG connector. Therefore, by connecting the LG connector to a light source device (not shown), the illumination light emitted from the light source device is transmitted to the illumination optical systems 52 and 52 via the light guide, and forward from the illumination optical systems 52 and 52. Irradiates the observation range.

  The air / water supply nozzle 54 communicates with a valve (not shown) operated by the air / water feed button 26 in FIG. 1, and this valve communicates with an air / water supply connector (not shown) provided on the LG connector. Is done. An air / water supply means (not shown) is connected to the air / water supply connector to supply air and water. Therefore, by operating the air / water supply button 26, air or water can be ejected from the air / water supply nozzle 54 toward the observation optical system 50.

  The forceps port 56 communicates with a valve (not shown) operated by the suction button 28, and this valve is connected to a suction connector (not shown) of the LG connector. Therefore, by connecting a suction means (not shown) to the suction connector and operating the valve with the suction button 28, a lesioned part or the like can be sucked from the forceps port 56.

  The bending portion 42 is configured to be bent remotely by turning the angle knobs 34, 34 of the hand operating portion 12.

  FIG. 3 is a cross-sectional view of the bending portion 42. In the figure, various built-in objects inserted into the bending portion 42 are omitted.

  The bending portion 42 includes a predetermined number of angle rings 62, 62... As the structure 60, and a node ring structure in which the adjacent angle rings 62, 62 are pivotally connected by pivot pins 64 in the vertical and horizontal directions. It has become. The angle ring 82 at the distal end portion is connected to the distal end hard portion 44, and the angle ring 84 at the proximal end portion is connected to the connection ring 66. The connection ring 66 is connected to the connection ring 88 of the flexible tube 40 via a connection portion 90. Furthermore, a net 68 made of a braided metal wire is attached to the outer periphery of the structure 60, and this net 68 is covered with a fluororubber outer skin 70.

  The bending portion 42 is bent up and down and left and right by remote control by the angle knobs 34 and 34 of the hand operation portion 12 shown in FIG. 1. For this purpose, the four operation wires 72 from the hand operation portion 12 are bent. , 72 (see FIG. 3) extend into the insertion portion 14. The distal ends of these operation wires 72, 72... Are fixed to the angle ring 82 at the distal end constituting the bending portion 42. And in the curved part 42, the relationship which makes | forms 90 degrees mutually in the circumferential direction is hold | maintained through the insertion hole provided in the pivot pin 64, for example.

  On the other hand, each operation wire 72, 72... Is inserted into the close coil spring inside the flexible tube 40 and extends to the hand operation unit 12. The operation wire 72 is composed of an upper and lower pair and a left and right pair. When one of the upper and lower operation wires 72 is pulled into the hand operation unit 12 and operated so as to extend the other, the bending portion 42 bends in the vertical direction. . Further, when one of the left and right operation wires 72 is pulled toward the hand operation unit 12 and operated to extend the other, the bending portion 42 bends in the left-right direction. It should be noted that the operation wires 72 do not necessarily have to be provided in a pair on the top and bottom and on the left and right.

  As shown in the partially cutaway view of FIG. 4, the flexible tube 40 of the embodiment has a screw tube 74 called a flex that protects the inside while maintaining flexibility in order from the inside, and on the screw tube 74. It is composed of three layers: a net 76 that is covered and called a blade, and a resin outer skin 80 that is covered on the net 76. The screw tube 74, the net 76, and the outer skin 80 are joined at least at both ends. Has been.

  The screw tube 74 is configured by winding a thin thin strip plate made of stainless steel or the like with a gap in a spiral shape. In FIG. 4, an example of a single-winding screw tube 74 is shown, but a double-winding screw tube in which screw tubes having opposite spiral directions are arranged so as to be in contact with the outer peripheral surface may be employed.

  The net 76 is configured by knitting a large number of metal fibers so as to cross each other and form a mesh. The metal fiber is not particularly limited as long as it can exert a sufficient rigidity effect on the flexible tube 40, and a general metal fiber used for the net 76 may be used. Particularly suitable metal fibers include stainless steel having a diameter of about 0.1 mm.

  The outer skin 80 is made of resin, and needs to have characteristics that can protect the inside of the flexible tube 40 and that does not affect the living body when the endoscope 10 is inserted into the body. As the outer skin 80, polyurethane resin, vinyl chloride, nylon, polyester, synthetic resin such as Teflon (registered trademark), polystyrene resin, polyethylene resin, polypropylene resin, polyester resin, polyurethane resin, polyamide resin, poly Vinyl chloride resins, fluorine resins, and mixtures thereof can be employed. In particular, a polyurethane resin can be suitably used. Of these, polyurethane resins are particularly preferred.

  In the flexible tube 40 including the screw tube 74, the net 76, and the outer skin 80, there is no particular limitation on the method of covering the outer surface of the screw tube 74 with the net 76, but as an example, a hollow (tubular) net 76 is provided. After inserting the screw tube 74, the net 76 is stretched by an appropriate means until there is no gap between the screw tube 74 and the net 76 so that the net 76 is in close contact with the outer peripheral surface of the screw tube 74. The method of making it coat | cover.

  The method for covering the outer skin 80 with the outer peripheral surface of the net 76 is not particularly limited. As an example, a resin melted at 150 to 250 ° C. is uniformly applied to the outer peripheral surface of the net 76 using a known extruder. There is a method in which the outer skin 80 is directly formed on the outer peripheral surface of the net 76 by cooling immediately after adhering to the thickness and then cooling. The adhesive for adhering the outer skin 80 to the net 76 is not particularly limited as long as it can adhere the net 76 and the outer skin 80 and can suppress a decrease in the adhesion between the net 76 and the outer skin 80. Preferably, an adhesive formed of a polyester-based resin or a polystyrene-based resin, and more preferably a thermoplastic polyurethane-based elastomer can be suitably used.

  Next, the configuration of the flexible tube 40 of the embodiment will be described.

  FIG. 5 is an enlarged view of a main part of the flexible tube 40 bent in a curved shape.

  When the flexible tube 40 is bent into a curved shape, the inner portion 80A of the outer skin 80 of the curved flexible tube 40 receives a stress P1 that tends to shrink toward the bending center point 0. Therefore, when the outer skin 80 is joined to the screw tube 74 in a state of being pulled in the axial direction of the outer skin 80 (extended state) and the tensile force P2 is set to be equal to or greater than the maximum value of the assumed stress P1. The buckling does not occur in the inner portion 80A even if the outer skin 80 is curved.

  The flexible tube 40 is curved when the endoscope 10 is used, but the minimum curvature radius R of the curved portion is generally about 50 mm. Here, if the diameter D of the flexible tube 40 is 10 mm, the inner portion 80A has a contraction rate of about 10% (1-50 / 55).

  Therefore, in the flexible tube 40 attached to the screw tube 74 in a state in which the outer skin 80 is extended by 5% with respect to the natural length (length at normal temperature), the inner portion 80A when the outer skin 80 is curved shrinks by 5%. The outer portion 80B extends 15%. Further, when the outer skin 80 is attached to the screw tube 74 in a state where it is extended by 15% with respect to the natural length, the inner portion 80A when the outer skin 80 is curved shrinks by 5%, and the outer portion 80B extends by 25%.

  As for the characteristics of the resin of the outer skin 80, for example, in the case of milactolan (trade name: manufactured by Nihon Milactolan Co., Ltd.), the elongation at break is about 50%, so that there is no problem. Because it is 2%, there is no problem in function. Further, the shrinkage of 5% of the inner portion 80 </ b> A does not peel off from the net 76 due to the adhesion with the net 76. Therefore, by attaching the outer skin 80 to the screw tube 80 in a state where the outer skin 80 is extended by 5 to 15% with respect to the natural length, the outer skin 80 is optimal in terms of both elongation and shrinkage of the resin. The same applies to other resins.

  Therefore, in the flexible tube 40 according to the embodiment, even if the flexible tube 40 is curved, the outer skin 80 does not peel off from the screw tube 74 and does not buckle, so that the service life of the flexible tube 40 is extended. .

  As a method of assembling the screw tube 80 in a state where the outer skin 80 is extended by 5 to 15%, as shown in the schematic diagram of FIG. 6A, a screw tube 74 having a spring structure is used as shown in FIG. 5 to 15% is contracted in the axial direction. In this state, the outer skin 80 is extruded at a molding temperature of 150 to 250 ° C. and attached to the screw tube 74. Thereafter, the jig 92 is removed from the screw tube 74. According to this method, as shown in FIG. 6C, the outer skin 80 can be extended by a predetermined amount in the axial direction of the outer skin 80 by the elastic restoring force of the screw tube 74 at normal temperature. Thus, the extension amount of the outer skin 80 can be set to 5 to 15%.

  As another method, as shown in the schematic diagram of FIG. 7A, the screw tube 74 is made of a shape memory alloy that heat-shrinks in the axial direction of the screw tube 74, and is in a normal temperature state (0 to 50 ° C.). The outer skin 80 is coated and formed on the screw tube 74 at a temperature of 150 ° C. or more, and the screw tube 74 is contracted in the axial direction by the shape recovery effect as shown in FIG. After that, as shown in FIG. 7C, the outer skin 80 can be extended by a predetermined amount in the axial direction of the outer skin 80 by the extension force of the screw tube 74 by setting it to the shape recovery temperature or lower (0 to 50 ° C.). Therefore, by adjusting the molding temperature of the outer skin 80, the extension amount of the outer skin 80 can be set to 5 to 15%.

  In addition, a shape memory alloy member 93, which is a separate member from the screw tube 74, is inserted into the inner periphery or outer periphery of the screw tube 74, and both ends of the shape memory alloy member 93 are connected to the screw tube 74 or the net 76. The extension amount of the outer skin 80 may be set to 5 to 15% by the above-described covering molding procedure of the outer skin 80.

  The relationship between the molding temperature of the outer skin 80 and the shape recovery temperature of the shape memory alloy will be described. First, the resin molding temperature of the outer skin 80 is generally 150 to 250 ° C. Next, the shape recovery temperature of the shape memory alloy can be set to 20 to 100 ° C., for example, in the case of a NiTi alloy, and the use temperature of the endoscope is about 40 ° C. at the maximum in the body. What is necessary is just to set the shape recovery temperature of a memory alloy to about 40-100 degreeC. In consideration of the storage state of the endoscope 10, the shape recovery temperature is preferably 70 to 100 ° C.

  Since the heat of 150 ° C. or more is applied during the resin molding of the outer skin 80, the shape memory alloy is in a contracted state, and the outer skin 80 is coated and molded thereon. The outer skin 80 is also stretched. Furthermore, when forming the outer skin 80, the shape memory alloy is warmed to the shape recovery temperature in advance, so that the outer skin 80 can be covered in a state where the shape memory alloy is further contracted.

  Furthermore, as another method, as shown in FIG. 8A, the elastic member 94 is inserted into the assembled flexible tube 40 in a contracted state, and both ends of the elastic member 94 are attached to the outer skin 80. To join. Then, as shown in FIG. 8B, the outer skin 80 may be extended by a predetermined amount in the axial direction of the outer skin 80 by the extension force of the elastic member 94. The elastic member 94 may be a close coil spring through which a wire 72 for bending the bending portion 42 shown in FIG. 3 is inserted, or may be another elastic member.

  DESCRIPTION OF SYMBOLS 10 ... Endoscope, 12 ... Hand operation part, 14 ... Insertion part, 16 ... Universal cable, 26 ... Air supply / water supply button, 28 ... Suction button, 30 ... Shutter button, 34 ... Angle knob, 38 ... Forceps insertion part , 40 ... Flexible tube, 42 ... Curved portion, 44 ... Hard tip portion, 50 ... Observation optical system, 52 ... Illumination optical system, 54 ... Air / water supply nozzle, 56 ... Forceps port, 60 ..., 62 ... Angle ring , 64 ... Pivoting pin, 66 ... Connecting ring, 68 ... Net, 70 ... Outer skin, 72 ... Operation wire, 74 ... Screw tube, 76 ... Net, 80 ... Outer skin, 80A ... Inner part, 80B ... Outer part, 82 ... Angle ring, 84 ... Angle ring, 88 ... Connection ring, 90 ... Connection part, 92 ... Jig, 94 ... Elastic member

Claims (14)

In a flexible tube for an endoscope in which the outer peripheral surface of a screw tube configured by spirally winding a belt-shaped plate is covered with a net, and the outer peripheral surface of the net is covered with a resin outer skin,
The flexible tube for an endoscope, wherein the outer skin is attached to the screw tube or the net in a state where the outer skin is extended by a predetermined amount in the axial direction of the outer skin.   The outer skin is attached to the screw tube in a state where the screw tube is contracted in the axial direction of the screw tube, and the outer skin is extended by a predetermined amount in the axial direction of the outer skin by the elastic restoring force of the screw tube. The flexible tube for an endoscope according to claim 1.   The screw tube is made of a shape memory alloy that heats and shrinks in the axial direction of the screw tube, and the shape of the screw tube is recovered in the axial direction by coating the outer skin of the screw tube at a temperature of 150 ° C. or more. The endoscope according to claim 1, wherein the outer skin is stretched by a predetermined amount in the axial direction of the outer skin by an extension force of the screw tube by being contracted by an effect, and thereafter being not more than the shape recovery temperature. Flexible tube.   A shape memory alloy member that heat-shrinks in the axial direction is inserted and disposed inside or outside the screw tube, and the shape memory alloy member is formed by covering the outer surface of the screw tube at a temperature of 150 ° C. or more. The outer skin is stretched by a predetermined amount in the axial direction of the outer skin by the stretching force of the shape memory alloy member by shrinking in the axial direction due to the shape recovery effect and then lowering to the shape recovery temperature or lower. Item 2. The flexible tube for an endoscope according to Item 1.   The endoscope flexible tube according to claim 1, wherein the outer skin is extended by a predetermined amount in an axial direction of the outer skin by an extension force of an elastic member inserted into the endoscope flexible tube.   6. The flexible endoscope according to claim 5, wherein the elastic member is a close coil spring through which a wire for bending a bending portion connected to a distal end portion of the flexible tube for endoscope is inserted. tube.   The flexible tube for an endoscope according to any one of claims 1 to 6, wherein an elongation rate of the outer skin is 5 to 15% with respect to a natural length. In the assembling method of the flexible tube for an endoscope, the outer peripheral surface of a screw tube configured by spirally winding a belt-shaped plate is covered with a net, and the outer peripheral surface of the net is covered with a resin outer skin.
A method for assembling a flexible tube for an endoscope, comprising attaching the outer skin to the screw tube or the net in a state where the outer skin is extended by a predetermined amount in the axial direction of the outer skin.   The outer skin is attached to the screw tube in a state where the screw tube is contracted in the axial direction of the screw tube, and the outer skin is extended by a predetermined amount in the axial direction of the outer skin by an elastic restoring force of the screw tube. The assembly method of the flexible tube for endoscopes of 8.   The screw tube is made of a shape memory alloy that is heated and shrunk in the axial direction of the screw tube, and the outer tube is coated and formed at a temperature of 150 ° C. or more on the screw tube so that the screw tube has a shape recovery effect in the axial direction. The flexible tube for an endoscope according to claim 8, wherein the outer skin is stretched by a predetermined amount in the axial direction of the outer skin by the extension force of the screw tube by being contracted and thereafter being made the shape recovery temperature or lower. Assembly method.   A shape memory alloy member that heat-shrinks in the axial direction is inserted and arranged inside or outside the screw tube, and the shape memory alloy member is coated on the screw tube at a temperature of 150 ° C. or more. 9. The outer skin is stretched by a predetermined amount in the axial direction of the outer skin by contraction in the axial direction due to the shape recovery effect, and thereafter the temperature is lower than the shape recovery temperature by the extension force of the shape memory alloy member. The assembly method of the flexible tube for endoscopes as described in any one of Claims 1-3.   9. The endoscope usable according to claim 8, wherein the elastic member is contracted and inserted into the flexible tube for endoscope, and the outer skin is extended by a predetermined amount in an axial direction of the outer skin by an extension force of the elastic member. Assembling method of flexible tube.   The flexible endoscope according to claim 12, wherein the elastic member is a close coil spring through which a wire for bending a bending portion connected to a distal end portion of the flexible tube for endoscope is inserted. Tube assembly method.   The method for assembling a flexible tube for an endoscope according to any one of claims 8 to 13, wherein an elongation rate of the outer skin is 5 to 15% with respect to a natural length.

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