JP2006167309A - Outer coat fixing method, flexible tube for endoscope and endoscope - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an outer coat fixing method by which an outer coat can be strongly fixed to a member arranged on the inner side thereof and high liquid-tightness can be maintained over a long period of time even when subjected to repeated disinfecting and sterilization processing, a flexible tube for an endoscope composed by fixing the outer coat to the member disposed on the inner side thereof by the outer coat fixing method, and the endoscope provided with the flexible tube for the endoscope. <P>SOLUTION: The outer coat fixing method comprises the steps of: disposing a core material 31 on the inner side of the outer coat 42 of a bending section 4; tightly bonding the outer coat 42 from the outer surface side by a thread for fixing the outer coat having a core part 91 constituted of a first resin as a main material and an outer layer coated on the outer periphery of the core part 91 and constituted of a second resin whose melting point is lower than that of the first resin as a main material; and fixing the outer coat 42 to the core material 31 by melting or softening the outer layer of the thread for fixing the outer coat and integrating the adjacent outer layers with each other. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an outer skin fixing method, an endoscope flexible tube, and an endoscope.

In the medical field, endoscopes are used for examination and diagnosis of the digestive tract and the like.
Such an endoscope includes an insertion portion flexible tube to be inserted into a body cavity, an operation portion for operating the insertion portion flexible tube, a connection portion flexible tube connected to the operation portion, and a connection portion. And a light source insertion portion connected to the distal end portion of the flexible tube.

  Among these, the insertion portion flexible tube has a long flexible tube portion and a bending portion that is connected to the distal end portion of the flexible tube portion and can be bent, and rotates the insertion portion flexible tube. By bending the bending portion, all directions in the body cavity can be observed.

  Usually, each of the flexible tube portion and the bending portion is configured by covering a core material with a flexible outer skin. And the connection of this flexible tube part and a bending part is performed as follows (for example, refer patent document 1).

  First, after joining the ends of the flexible tube and the core of the bending portion, the joint is covered with the outer skin of the bending portion, and the outer skin end of the flexible tube and the outer skin end of the bending portion are brought into contact with each other. Let

  Next, the outer skin of the flexible tube and the outer skin of the curved portion are respectively bound with a thread at a portion sandwiching the boundary portion, and then an adhesive is applied from above the thread.

  By applying an adhesive from the top of the thread thus bound, the thread is fixed to the outer skin of the flexible tube and the outer skin of the bending portion.

  By the way, the endoscope is subjected to cleaning, disinfection, and sterilization every time it is used. In recent years, from the viewpoint of improving safety, powerful treatment agents and processing methods have been adopted by sterilization. It has become.

  However, when such a powerful sterilization treatment is applied to an endoscope, the adhesive deteriorates, causing brittle fracture of the adhesive and a decrease in adhesive strength, and the thread is loosened to reduce the liquid tightness of the joint. There's a problem. When such a problem occurs, liquid such as disinfectant may enter the inside from this joint, and the endoscope may break down.

JP 2002-34900 A

  An object of the present invention is to provide an outer skin that can firmly fix the outer skin to a member disposed inside thereof, and can maintain high liquid-tightness over a long period of time even when repeated disinfection and sterilization processes are performed. Provided are a flexible tube for an endoscope in which the outer skin is fixed to a member disposed on the inner side by the fixing method, and an endoscope including the flexible tube for an endoscope. There is to do.

Such an object is achieved by the present inventions (1) to (10) below.
(1) An outer skin fixing method for fixing the outer skin to a member disposed inside the outer skin of the flexible tube for an endoscope,
A first step of disposing the member inside the outer skin;
An outer skin having a core portion made of a first resin as a main material and an outer layer covered on the outer periphery of the core portion and made of a second resin having a melting point lower than that of the first resin as a main material A second step of binding the outer skin from its outer surface side with a fixing thread;
A third step of fixing the outer skin to the member by melting or softening the outer layer of the outer skin fixing yarn and integrating the adjacent outer layers together. Fixing method.

  As a result, the outer skin can be firmly fixed to the member disposed on the inner side, and high liquid tightness can be maintained for a long time even when repeated disinfection and sterilization processes are performed.

(2) As the outer thread fixing thread, a thread whose central axis is shifted from the central axis of the core part,
In the second step, the outer skin fixing method according to the above (1), wherein the outer skin is bound with the outer skin fixing thread so that the side on which the central axis of the core portion is biased becomes the outer skin side.

  Thereby, an outer skin can be fixed more firmly with respect to the member arrange | positioned inside.

(3) When the skin fixing yarn has a melting point of the first resin of m ₁ [° C.] and a melting point of the second resin of m ₂ [° C.],
The skin fixing method according to (1) or (2), wherein m ₁ -m ₂ satisfies a relationship of 10 or more.

  Thereby, even when the heating temperature fluctuates slightly when heating the outer skin fixing yarn, the outer layer can be more reliably melted or softened while preventing the core portion of the outer skin fixing yarn from melting more reliably. it can.

(4) The skin fixing method according to any one of (1) to (3), wherein the melting point m ₁ of the first resin is 230 ° C. or higher.

  By constituting the core portion using the first resin having such a melting point as a main material, melting or softening of the core portion can be more reliably prevented when the outer shell fixing yarn is heated.

  (5) The first resin is mainly composed of at least one of polyester, polyphenylene sulfide, polycarbonate, fluororesin, aramid resin, polyetheretherketone, polyamideimide, and polyarylate (1 ) To the outer skin fixing method according to any one of (4) to (4).

  By constituting the core part with these resins, a core part (sheath fixing thread) having excellent heat resistance and excellent tensile strength (toughness resistance) can be obtained.

(6) The skin fixing method according to any one of (1) to (5), wherein the melting point m2 of the _second resin is 220 ° C. or lower.

  By configuring the outer layer using the second resin having such a melting point as the main material, the outer layer can be easily or reliably melted or softened when the outer shell fixing yarn is heated.

  (7) The skin fixing method according to any one of (1) to (6), wherein the second resin is mainly composed of at least one of polypropylene, polyethylene, polyamide, and polystyrene.

  Since these resins have a particularly low melting point, the outer skin can be easily and reliably fixed to the members disposed inside thereof. In addition, since these resins are difficult to hydrolyze or do not substantially hydrolyze, even when autoclave sterilization is repeated, the resin layer (second resin) covering the core is altered and deteriorated. Can be prevented.

(8) The melting point of the first resin and the melting point of the second resin in the outer thread fixing yarn are m ₁ [° C.] and m ₂ [° C.], respectively, and the heating temperature in the third step is T When [℃]
The outer skin fixing method according to any one of the above (1) to (7), which satisfies a relationship of m ₂ ≦ T ≦ m ₂ + (m ₁ −m ₂ ) × 0.9.

  As a result, even when the heating temperature fluctuates slightly when heating the outer skin fixing yarn, the outer layer can be reliably melted or softened while reliably preventing the core portion of the outer skin fixing yarn from melting.

(9) a flexible tube having a core and an outer skin covering the outer periphery of the core;
A flexible tube for an endoscope, which is provided at a distal end portion of the flexible tube portion and includes a core material and a curved portion having an outer skin covering the outer periphery of the core material,
The proximal end portion of the outer skin of the bending portion and the distal end portion of the outer skin of the flexible tube portion are formed by the method of fixing the outer skin according to any one of the above (1) to (8). A flexible tube for an endoscope which is fixed to a core material of a flexible tube portion.

  Thereby, even when disinfection and sterilization are repeatedly performed, a flexible tube for an endoscope that can maintain high liquid tightness over a long period of time can be obtained.

(10) An endoscope comprising the flexible tube for an endoscope according to (9).
Thereby, even when disinfection and sterilization are repeatedly performed, an endoscope capable of maintaining high liquid tightness over a long period of time can be obtained.

  ADVANTAGE OF THE INVENTION According to this invention, the outer skin of the flexible tube for endoscopes can be firmly fixed with respect to the member arrange | positioned inside.

  In addition, the core part that binds the outer skin and is fixed to the member disposed on the inside is covered with resin. However, since resin is superior in chemical resistance and heat resistance compared to adhesives, it is repeated. Even when sterilization and sterilization are performed, alteration and deterioration of the resin are prevented. For this reason, the fixed state with respect to the member of the outer skin by a core part is maintained reliably, and high liquid-tightness can be maintained over a long period of time.

  Moreover, the resistance in autoclave sterilization can be provided by selecting the kind of this resin suitably, for example, selecting the thing which is hard to hydrolyze or does not hydrolyze substantially.

  Further, as the outer thread fixing thread, the outer axis is shifted from the central axis of the core part, and the outer skin is fastened so that the side on which the central axis of the core part is biased becomes the outer skin side. Can be more firmly fixed to the core material.

  Hereinafter, the skin fixing method, endoscope flexible tube and endoscope of the present invention will be described in detail based on preferred embodiments shown in 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 which shows the structure of (the flexible tube for endoscopes of this invention). In the following description, the upper side in FIG. 1 is referred to as the “base end”, the lower side is referred to as the “tip”, the right side in FIG.

  An electronic endoscope 1 shown in FIG. 1 is connected to a long insertion portion flexible tube 2 having flexibility (flexibility) and a proximal end portion of the insertion portion flexible tube 2, and is held by an operator. An operation unit 6 for operating the entire electronic endoscope 1, a connection portion flexible tube 7 connected to the operation unit 6, and a light source insertion portion 8 connected to the distal end portion of the connection portion flexible tube 7. Have.

  The insertion portion flexible tube 2 is used by being inserted into a lumen (body cavity) of a living body, for example. As shown in FIG. 1, the insertion portion flexible tube 2 includes a flexible tube portion 3 from the hand (base end) side, and a bending portion 4 provided at the distal end portion of the flexible tube portion 3 and capable of bending operation. Have.

  Each of the flexible tube portion 3 and the bending portion 4 is provided with a space in which a built-in material (not shown) such as an optical fiber, an image signal cable, or tubes (not shown) can be placed and inserted. It has been.

  As shown in FIG. 2, the flexible tube portion 3 includes a core material 31 and an outer skin 32 that covers the outer periphery of the core material 31.

  The core material 31 includes a spiral tube 311 and a mesh tube (braided body) 312 that covers the outer periphery of the spiral tube 311, and is formed as a long tube-like object as a whole.

  The spiral tube 311 is formed by winding a strip-like material with a uniform diameter in a spiral manner with a gap 313 therebetween. For example, stainless steel or copper alloy is preferably used as the material constituting the belt-like material.

  The mesh tube 312 is formed by braiding a plurality of metal or non-metallic thin wires. As a material constituting the fine wire, for example, stainless steel, copper alloy and the like are preferably used. Further, at least one of the fine wires forming the mesh tube 312 may be coated with a synthetic resin (not shown).

  The core material 31 is covered with an outer skin 32 except for the tip. The outer skin 32 is composed mainly of a resin material.

  The resin material is not particularly limited as long as it has flexibility (flexibility), and examples thereof include polyethylene, polypropylene, ethylene-propylene copolymer, and ethylene-vinyl acetate copolymer (EVA). Polyolefin, cyclic polyolefin, modified polyolefin, polyvinyl chloride, polyvinylidene chloride, polystyrene, polyamide, polyimide, polyamideimide, polycarbonate, poly- (4-methylpentene-1), ionomer, acrylic resin, polymethyl methacrylate, acrylonitrile Butadiene-styrene copolymer (ABS resin), acrylonitrile-styrene copolymer (AS resin), butadiene-styrene copolymer, polyoxymethylene, polyvinyl alcohol (PVA), ethylene-vinyl alcohol co Polyester such as coalescence (EVOH), polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polycyclohexane terephthalate (PCT), polyether, polyetherketone (PEK), polyetheretherketone (PEEK), polyetherimide, Polyacetal (POM), polyphenylene oxide, modified polyphenylene oxide, polysulfone, polyethersulfone, polyphenylene sulfide, polyarylate, aromatic polyester (liquid crystal polymer), polytetrafluoroethylene, polyvinylidene fluoride, other fluorine resins, styrene, Polyolefin, polyvinyl chloride, polyurethane, polyester, polyamide, polybutadiene, trans polyisoprene, Examples include various types of thermoplastic elastomers such as silicon rubber and chlorinated polyethylene, and copolymers, blends, polymer alloys, etc. mainly composed of these, and use one or more of these in combination. Can do.

  The average thicknesses of the outer skin 32 and the outer skin 42 to be described later can protect the built-in objects disposed in the flexible tube portion 3 and the bending portion 4, respectively. Although it will not specifically limit if it does not prevent flexibility and curvature, It is preferable that it is about 100-3000 micrometers, and it is more preferable that it is about 200-1000 micrometers.

As shown in FIG. 1, a scale 22 indicating the insertion depth into the body cavity is attached to the outer surface of the flexible tube portion 3. As a result, when the insertion portion flexible tube 2 is inserted into the body cavity, the tip of the insertion portion flexible tube 2 can be reliably guided to a desired position by operating while observing the scale 22. it can.
The bending portion 4 is connected to the distal end portion of the flexible tube portion 3.

  As shown in FIG. 2, the bending portion 4 includes a core material 41 and an outer skin 42 that covers the outer periphery of the core material 41.

  The core member 41 includes a node ring assembly 411 and a mesh tube 412 that covers the outer periphery of the node ring assembly 411, and is formed as a long tube-like object as a whole.

  The node ring assembly 411 is configured by arranging a plurality of node rings 411a having a substantially circular cross section in parallel along the center line A (axis). In these node rings 411a, adjacent node rings 411a are connected to each other by rivets (not shown) and can be tilted with respect to each other. As a material constituting the node ring 411a, for example, stainless steel, copper alloy, or the like is preferably used.

  The node rings 411a are provided with wire guides (not shown) for each predetermined number of node rings 411a. The wire guide is inserted into a bending operation wire that is connected to a rigid portion 5 to be described later and continuously disposed in the bending portion 4 and the flexible tube portion 3. For example, the bending operation wires are provided in two pairs as a pair. By pulling or releasing each bending operation wire, the bending portion 4 is operated to bend in an arbitrary direction with the inclination of the node ring 411a. The

  At this time, the bending operation wire is supported by the wire guide so as to be able to advance and retract in the distal direction and the proximal direction.

  The outer periphery of the node ring assembly 411 is covered with a mesh tube 412 having the same configuration as the mesh tube 312.

  The base end portion of the core material 41 is connected to the distal end portion of the core material 31 included in the flexible tube portion 3 via the connection tube 43.

On the outer periphery of the core material 41, both end portions of the core material 41 protrude and are covered with an outer skin 42.
Both end portions of the outer skin 42 cover the proximal end portion of the rigid portion 5 described later and the distal end portion of the core member 31 provided in the flexible tube portion 3. In other words, the proximal end portion of the rigid portion 5 and the distal end portion of the core material 31 are inserted (arranged) inside the both end portions of the outer skin 42, respectively.

  Then, by the outer skin fixing method of the present invention, the distal end portion of the outer skin 42 of the bending portion 4 is fixed to the hard portion 5 (member disposed inside the outer skin), and the proximal end portion of the outer skin 42 of the bending portion 4 and The distal end portion of the outer skin 32 of the flexible tube portion 3 is fixed to the core material 31 (a member disposed inside the outer skin) of the flexible tube portion 3.

The outer skin 42 is composed of a rubber material as a main material.
The rubber material is not particularly limited. For example, butadiene rubber such as natural rubber (NR), isoprene rubber (IR), butadiene rubber (BR, 1,2-BR), styrene-butadiene rubber (SBR), and chloroprene. Diene special rubber such as rubber (CR), butadiene-acrylonitrile rubber (NBR), butyl rubber (IIR), ethylene-propylene rubber (EPM, EPDM), acrylic rubber (ACM, ANM), halogenated butyl rubber (X-IIR) ) Olefin rubber, urethane rubber (AU, EU), etc., hydrin rubber (CO, ECO, GCO, EGCO) ether rubber, polysulfide rubber (T), etc., polysulfide rubber, silicone rubber (Q), fluoro rubber (FKM, FZ), chlorinated polyethylene (CM), etc. It is, can be used singly or in combination of two or more of them.

  A rigid portion 5 is connected to the distal end portion of the curved portion 4. The rigid part 5 is composed of a cylindrical block body.

An imaging device (CCD) (not shown) that captures a subject image at an observation site is provided inside the rigid portion 5, and the imaging device is provided in the insertion portion flexible tube 2, the operation portion 6, and the connection portion. An image signal cable (not shown) continuously disposed in the flexible tube 7 is connected to an image signal connector 82 provided in the light source insertion portion 8.
Further, the distal end of the bending operation wire is fixed to the rigid portion 5.

  Although it does not specifically limit as a constituent material of the hard part 5, For example, stainless steel, aluminum or an aluminum alloy, titanium, or a titanium alloy etc. are mentioned.

  Further, a light source connector 81 is provided along with an image signal connector 82 at the distal end of the light source insertion portion 8, and the light source connector 81 and the image signal connector 82 are connected to a connection portion of a light source processor device (not shown). The light source insertion unit 8 is connected to the light source processor device. A monitor device (not shown) is connected to the light source processor device via a cable.

  The light emitted from the light source processor device is continuously arranged in the light source connector 81, the light source insertion portion 8, the connection portion flexible tube 7, the operation portion 6 and the insertion portion flexible tube 2. The light passes through a light guide (not shown), and the observation site is irradiated from the tip of the rigid portion 5 to illuminate. 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 transmitted to the light source insertion unit 8 via the image signal cable.

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) picked up by the image pickup device, that is, a video endoscope monitor image is displayed.
Further, the operation unit 6 is provided with a first operation knob 61, a second operation knob 62, a first lock lever 63, and a second lock lever 64 on the upper surface in FIG. .
When the operation knobs 61 and 62 are rotated, a bending operation wire (not shown) disposed in the insertion portion flexible tube 2 is pulled, and the bending portion 4 is bent in four directions. You can change direction.

  Further, when the lock levers 63 and 64 are rotated counterclockwise, the bending state (the bending state in the vertical direction and the horizontal direction) of the bending portion 4 can be fixed (held), respectively. When the rotation operation is performed, the bending portion 4 fixed in the bent state can be released.

  Further, a plurality (three in this embodiment) of control buttons 65, suction buttons 66, and air / liquid feeding buttons 67 are provided on the side surface (circumferential surface) in FIG.

  While the electronic endoscope 1 is connected to the light source processor device (external device), by pressing each control button 65, various operations of peripheral devices such as the light source processor device and the monitor device (for example, moving images of electronic images) And a still image, an electronic image filing system and an imaging device can be operated and / or stopped, and an electronic image recording device can be operated and / or stopped.

  The suction button 66 and the air / liquid supply button 67 are respectively formed continuously in the light source insertion portion 8, the connection portion flexible tube 7, the operation portion 6 and the insertion portion flexible tube 2, respectively. Has a function of opening and closing a suction channel and an air / liquid feeding channel (both not shown) opened at the distal end of the insertion portion flexible tube 2 and opened at the other end by the light source insertion portion 8.

  That is, before the suction button 66 and the air / liquid feeding button 67 are pressed, the suction channel and the air / liquid feeding channel are closed (the fluid cannot pass through), When the suction button 66 and the air / liquid feeding button 67 are pressed, the suction channel and the air / liquid feeding channel are communicated (the fluid can pass).

  When the electronic endoscope 1 is used, suction means is connected to the other end of the suction channel, and air supply / liquid supply means is connected to the other end of the air / liquid supply channel.

  Thereby, in a state where the suction channel is in communication, body fluid or blood in the body cavity can be sucked from the distal end of the insertion portion flexible tube 2, and in the state where the air / liquid supply channel is in communication, the insertion portion Liquid or gas can be supplied from the distal end of the flexible tube 2 into the body cavity.

Next, the skin fixing method of the present invention will be described.
In the following, the skin fixing method of the present invention will be described by taking, as an example, the case where the flexible tube portion and the bending portion are joined in the insertion portion flexible tube included in the endoscope shown in FIG.
FIGS. 3 and 4 are views (partial longitudinal sectional views) for explaining the outer skin fixing method of the present invention, respectively, (b) and (c) in FIG. 3, and (a) and (b) in FIG. ) Is an enlarged view of the vicinity of the outer skin.

  [1] First, the flexible tube portion 3 in which the outer periphery of the core material 31 is covered with the outer skin 32 and the curved portion 4 in which the outer periphery of the core material 41 is covered with the outer skin 42 are prepared.

  Next, as shown in FIG. 3A, the distal end portion of the core material 31 and the proximal end portion of the core material 41 are coupled via the connection pipe 43, and the outer skin 42 is put on the distal end portion of the core material 31 ( First step).

  [2] Next, as shown in FIG. 3 (b), the distal end portions of the base end portions of the outer skin 32 and the outer skin 42 are continuously bound from the outer surface side by the outer skin fixing thread 9 (first surface). Step 2).

Here, in the present invention, as the outer skin fixing thread 9, the core portion 91 made of the first resin as a main material and the outer periphery of the core portion 91 are covered with a lower melting point than that of the first resin. The one having the outer layer 92 composed mainly of the resin 2 is used.
The configuration of the outer skin fixing thread 9 will be described in detail later.

  [3] Next, the skin fixing yarn 9 is heated at a temperature T higher than the melting point of the second resin and lower than the melting point of the first resin (third step).

  By this heating, the outer layer 92 is melted or softened, and the adjacent outer layers 92 are integrated with each other, but the core 91 is prevented (blocked) from being melted or softened and maintains its shape.

  Then, by finishing the heating, the second resin is solidified and a resin layer 93 is formed as shown in FIG.

  Accordingly, the core 91 is fixed to the outer surfaces of the outer skin 32 and the outer skin 42 by the resin layer 93 in a state where the outer skin 32 and the outer skin 42 are tightly bound, and the outer skin 32 and the outer skin 42 are firmly fixed to the core material 31. Is done. At this time, the boundary portion between the outer skin 32 and the outer skin 42 is also covered with the resin layer 93. As a result, high liquid tightness is ensured between the flexible tube portion 3 and the bending portion 4.

  In addition, the resin layer 93 composed of a resin (second resin) is superior in chemical resistance and heat resistance as compared to an adhesive. Therefore, even when the electronic endoscope 1 is repeatedly sterilized and sterilized, the resin layer 93 is prevented from being altered or deteriorated. For this reason, the fixed state with respect to the core material 31 of the outer skin 32 and the outer skin 42 by the core part 91 is reliably maintained, and the high liquid-tightness between the flexible tube part 3 and the bending part 4 can be maintained over a long period of time. .

  Moreover, since the unevenness | corrugation by the core part 91 formed in the outer surface of the insertion part flexible tube 2 eases or lose | disappears by the resin layer 93, when inserting the insertion part flexible tube 2 in a body cavity, a patient's pain Can be prevented from increasing.

The heating temperature T may be any temperature that is higher than the melting point of the second resin and lower than the melting point of the first resin, but the melting point of the first resin and the melting point of the second resin. the, _{m 1} [° C.], respectively, when the _{m 2} [° C.], it is preferable to satisfy _{m 2 ≦ T ≦ m 2 +} (m 1 -m 2) × 0.9 the relationship, _{m 2} ≦ T It is more preferable that the relationship of ≦ m ₂ + (m ₁ −m ₂ ) × 0.6 is satisfied. As a result, even when the heating temperature T fluctuates slightly when heating the outer skin fixing yarn 9, the outer layer 92 is reliably melted or softened while reliably preventing the core portion 91 of the outer skin fixing yarn 9 from melting. Can be made.

Next, the configuration of the outer skin fixing thread 9 will be described in detail.
As described above, in the present invention, the core portion 91 functions so as to bind the outer skin 32 and the outer skin 42 and fix them to the core material 31, and the outer layer 92 is adjacent by heating in the step [3]. What is to be integrated is made to function so as to fix the core 91 to the outer surfaces of the outer skin 32 and the outer skin 42.

  Therefore, the outer layer 92 is sufficiently melted or softened by the heating in the step [3], and the core portion 91 is not melted or softened and can be reliably maintained in its shape. Is preferred.

From such a viewpoint, it is preferable that the melting point of the first resin m ₁ [° C.] and the melting point of the second resin m ₂ [° C.] satisfy the relationship that m ₁ -m ₂ is 10 or more, It is more preferable to satisfy the relationship of 20 or more. As a result, when heating the outer skin fixing yarn 9, even when the heating temperature T slightly fluctuates, the outer layer 92 is more reliably prevented while more reliably preventing the core portion 91 of the outer skin fixing yarn 9 from melting. Can be melted or softened.

Specifically, it is preferable that melting | fusing point m1 of _1st resin is 230 degreeC or more, and it is more preferable that it is about 230-290 degreeC. By configuring the core portion 91 using the first resin having such a melting point as a main material, melting or softening of the core portion 91 can be more reliably prevented during the heating in the step [3].

  Examples of the first resin include polyester, polyphenylene sulfide, polycarbonate, fluorine resin, aramid resin, polyether ether ketone, polyamide imide, polyarylate, polyvinylidene chloride, polyamide, polyether sulfone, and polyether. Examples include imide, phenolic resin, urea resin, melamine resin, unsaturated polyester resin, epoxy resin, diallyl phthalate resin, silicone resin, polyimide, etc. Especially polyester, polyphenylene sulfide, polycarbonate, fluororesin, aramid resin, polyether Those containing at least one of ether ketone, polyamideimide and polyarylate as the main component are preferred. By configuring the core portion 91 with these resins, the core portion 91 having excellent heat resistance and excellent tensile strength (toughness resistance) can be obtained.

  Moreover, the core part 91 may be comprised by one fiber (single wire) which uses the 1st resin as the main material, and was obtained by bundling, knitting, twisting, etc. a plurality of fibers (single wire). It may be an aggregate of fibers.

  Although the average diameter of the core part 91 is not specifically limited, It is preferable that it is about 1-500 micrometers, and it is more preferable that it is about 10-300 micrometers. If the diameter of the core portion 91 is too small, depending on the type of the first resin, it may be difficult to bind the outer skin 32 and the outer skin 42 sufficiently and fix them to the core material 31. If the diameter of the core portion 91 is too large, the outer diameter of the insertion portion flexible tube 2 at the portion fastened with the outer skin fixing thread 9 becomes too large, and when inserting the insertion portion flexible tube 2 into the body cavity, the patient There is a risk of increased pain.

On the other hand, the melting point m ₂ of the second resin is not particularly limited as long as it is lower than the melting point m ₁ of the first resin, but is preferably 220 ° C. or less, more preferably about 100 to 220 ° C. . By configuring the outer layer 92 using the second resin having such a melting point as a main material, the outer layer 92 can be easily or reliably melted or softened during the heating in the step [3].

  Examples of the second resin include polyethylene, polypropylene, polyamide (nylon), polystyrene, polyvinyl chloride, and the like, and in particular, at least one of polyethylene, polypropylene, polyamide, and polystyrene is a main component. Are preferred. Since these resins have a particularly low melting point, the outer skin 32 and the outer skin 42 can be easily and reliably fixed to the core material 31. In addition, since these resins are difficult to hydrolyze or do not substantially hydrolyze, even when the electronic endoscope 1 is repeatedly subjected to autoclave sterilization, the resin layer 93 is not deteriorated or deteriorated. Is prevented. For this reason, the fixed state with respect to the core material 31 of the outer skin 32 and the outer skin 42 by the core part 91 is reliably maintained, and the high liquid-tightness between the flexible tube part 3 and the curved part 4 is more reliably maintained over a long period of time. can do.

  The outer layer 92 may have a single layer configuration or a multilayer configuration in which a plurality of resin layers are stacked.

  The average thickness of the outer layer 92 is not particularly limited, but is preferably about 1 to 100 μm, and more preferably about 5 to 50 μm. If the outer layer 92 is too thin, the function of fixing the core 91 to the outer surface of the outer skin 32 and the outer skin 42 may not be sufficiently exhibited depending on the types of the first resin and the second resin, the diameter of the core 91, and the like. On the other hand, if the outer layer 92 is too thick, the outer diameter of the insertion portion flexible tube 2 at the portion fastened with the outer skin fixing thread 9 becomes too large, and when inserting the insertion portion flexible tube 2 into the body cavity, Patient pain may increase.

  In addition, the thickness of the outer layer 92 may be substantially uniform over the entire circumference of the outer skin fixing yarn 9, or may be thicker (thinner) in a predetermined portion.

  For example, as shown in FIG. 4A, the outer skin fixing thread 9 may be one in which the central axis of the core 91 is misaligned with the central axis of the outer skin fixing thread 9.

  Such an outer skin fixing thread 9 is used to bind the outer skin 32 and the outer skin 42 so that the side on which the central axis of the core 91 is biased becomes the outer skin 32 and the outer skin 42 side in the step [2]. Is preferred.

  As a result, as shown in FIG. 4B, the state in which the distance (separation distance) between the core 91 and the outer surfaces of the outer skin 32 and the outer skin 42 is extremely small, that is, the looseness of the core 91 is extremely small. Thus, the core portion 91 can be fixed to the outer surfaces of the outer skin 32 and the outer skin 42.

  As a result, even when sterilization (especially autoclave sterilization) is repeatedly performed on the electronic endoscope 1, high liquid tightness between the flexible tube portion 3 and the curved portion 4 can be ensured over a long period of time. Can be maintained.

  As described above, the illustrated embodiment of the skin fixing method, the endoscope flexible tube, and the endoscope of the present invention has been described, but the present invention is not limited thereto.

  For example, the outer skin fixing method of this invention can also add the process of the arbitrary objectives as needed.

  In addition, the method for fixing the outer skin of the present invention is also applied to, for example, fixing the outer skin of the insertion portion flexible tube to the operation portion, and fixing the outer skin of the connection portion flexible tube to the operation portion or the light source insertion portion can do.

  Further, the configuration of each part of the endoscope can be replaced with an arbitrary one that can exhibit the same function, or an arbitrary configuration can be added.

  The endoscope of the present invention is not limited to an electronic endoscope, but may be an optical endoscope (fiberscope). Furthermore, the endoscope is not limited to a medical endoscope but is used for industrial purposes. It may be a mirror.

Next, specific examples of the present invention will be described.
1. Manufacture of electronic endoscope Ten electronic endoscopes shown in FIG. 1 were manufactured in each Example and each Comparative Example as follows.

Example 1
First, a hard part, a bending part and a flexible tube part as shown in FIG. 1 were prepared.

  Next, the base end portion of the rigid portion was inserted inside the distal end portion of the outer skin of the bending portion, and the distal end portion of the core material of the flexible tube portion was inserted and fixed inside the base end portion.

Next, the distal end portion of the outer skin of the bending portion, the proximal end portion of the outer skin of the bending portion, and the distal end portion of the outer skin of the flexible tube portion are bound with a thread for fixing the outer skin as shown in FIG. Heated in 10 minutes.
Next, an electronic endoscope was manufactured using the obtained joined body (endoscopic insertion portion).

The configuration of each part is as shown below.
・ Hard part Constituent material: Aluminum alloy Shape: Cylindrical shape, change in outer diameter in 3 stages Outer diameter of middle part: 9mm

・ Bending part ・ Dimension of node ring assembly: Outer diameter 9mm × Inner diameter 7mm
Construction material of node ring: Stainless steel Construction material of mesh tube: Stainless steel ・ Average thickness of outer skin: Outer diameter 10 mm × Inner diameter 9 mm (average thickness 500 μm)
Outer shell material: Fluoro rubber

・ Flexible tube part ・ Dimensions of core material: Outer diameter 9 mm × Inner diameter 7 mm
Constituent material of spiral tube: Stainless steel Constituent material of mesh tube: Stainless steel ・ Dimension of outer shell: Outer diameter 10 mm × Inner diameter 9 mm (average thickness 500 μm)
Outer skin component material: Polyurethane thermoplastic elastomer

-Thread for fixing the outer skin-Average diameter of the core: 150μm
Core material: Polyester (melting point: 260 ° C)
・ Average thickness of outer layer: 30μm
Constituent material of outer layer: Polypropylene (melting point: 160 ° C)

(Example 2)
An electronic endoscope was manufactured in the same manner as in Example 1 except that the following thread fixing thread was used.
The heating conditions were 250 ° C. × 10 minutes.

-Thread for fixing the outer skin-Average diameter of the core: 150μm
Core material: Polyphenylene sulfide (melting point: 285 ° C)
・ Average thickness of outer layer: 30μm
Constituent material of outer layer: Polyamide (melting point: 220 ° C.)

(Example 3)
An electronic endoscope was manufactured in the same manner as in Example 1 except that the following thread fixing thread was used.
The heating conditions were 180 ° C. × 10 minutes.

-Thread for fixing the outer skin-Average diameter of the core: 150μm
Core material: Polycarbonate (melting point: 230 ° C)
・ Average thickness of outer layer: 30μm
Material of outer layer: Polyethylene (melting point: 130 ° C)

(Examples 4 to 6)
As shown in FIG. 4, each of the electronic endoscopes was used in the same manner as in Examples 1 to 3 except that a thread whose center axis was shifted from the center axis of the core was used as the outer skin fixing thread. Manufactured.

(Comparative Example 1)
First, the same hard part, bending part and flexible tube part as those in Example 1 were prepared.

  Next, the base end portion of the rigid portion was inserted inside the distal end portion of the outer skin of the bending portion, and the distal end portion of the core material of the flexible tube portion was inserted and fixed inside the base end portion.

  Next, the distal end portion of the outer skin of the bending portion, the proximal end portion of the outer skin of the bending portion, and the distal end portion of the outer skin of the flexible tube portion were bound with a polyester thread. The average diameter of this yarn was 80 μm.

Next, the outer periphery of the yarn was covered with an epoxy adhesive to fix the yarn to the outer surface of the outer skin.
Next, an electronic endoscope was manufactured using the obtained joined body (endoscopic insertion portion).

(Comparative Example 2)
An electronic endoscope was manufactured in the same manner as in Comparative Example 1 except that polyphenylene sulfide was used as the yarn.

(Comparative Example 3)
An electronic endoscope was manufactured in the same manner as in Comparative Example 1 except that polycarbonate yarn was used.

2. Evaluation Each of the electronic endoscopes manufactured in each Example and each Comparative Example was repeatedly autoclaved and sterilized.
The conditions for one autoclave sterilization were 135 ° C. and 15 minutes.

For each electronic endoscope, after each autoclave sterilization was completed, the state of looseness of the core or thread was confirmed and evaluated according to the following four criteria.
◎: The core or thread is not loosened even after 1000 times. ○: There is a slight looseness in the core or thread after 1000 times. △: There is obvious looseness in the core or thread after 1000 times. X: At the end of 300 times, there is obvious looseness in the core or thread

For each electronic endoscope, after each autoclave sterilization was completed, the tip of the insertion tube was immersed in warm water at 40 ° C. for 10 minutes, and then immersed in cold water at 0 ° C. The image quality was confirmed and evaluated according to the following four criteria.
◎: No change in image quality of the subject image even after 1000 times. ○: Image quality of the subject image slightly decreased after 1000 times. △: Image quality of the subject image decreased after 1000 times. Yes ×: The image quality of the subject is degraded at the end of 300 times. The results are shown in Table 1 below.

  As shown in Table 1, in the electronic endoscopes manufactured in each of the examples, any looseness of the core portion is not recognized or only slightly recognized, and a change in the image quality of the subject image is recognized. There wasn't.

  In particular, as an outer skin fixing thread, an electronic endoscope that uses a thread whose center axis is shifted from the center axis of the core portion, and that binds the outer skin so that the side on which the center axis of the core portion is biased is the outer skin side ( In Examples 4 to 6), no looseness of the core was observed.

  On the other hand, in the electronic endoscopes manufactured in the respective comparative examples, when the autoclave sterilization was repeated 300 times, obvious slack was observed in the thread, and the image quality of the subject was affected by the cloudiness of the lens. There was a decrease due to.

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 a fragmentary longitudinal cross-section which shows the structure 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 (partial longitudinal cross-sectional view) for demonstrating the outer skin fixing method of this invention. It is a figure (partial longitudinal cross-sectional view) for demonstrating the outer skin fixing method of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Electronic endoscope 2 Insertion part flexible tube 22 Scale 3 Flexible tube part 31 Core material 311 Spiral tube 312 Reticulated tube 313 Gap 32 Outer skin 4 Bending part 411 Node ring assembly 411a Node ring 412 Reticulated tube 42 Outer skin 43 Connection tube 5 Rigid part 6 Operation part 61 1st operation knob 62 2nd operation knob 63 1st lock lever 64 2nd lock lever 65 Control button 66 Suction button 67 Air supply / liquid supply button 7 Connection part flexible tube 8 Light source insertion part 81 Light source connector 82 Image signal connector 9 Skin fixing thread 91 Core portion 92 Outer layer 93 Resin layer

Claims (10)

An outer skin fixing method for fixing the outer skin to a member disposed inside the outer skin of the flexible tube for an endoscope,
A first step of disposing the member inside the outer skin;
An outer skin having a core portion made of a first resin as a main material and an outer layer covered on the outer periphery of the core portion and made of a second resin having a melting point lower than that of the first resin as a main material A second step of binding the outer skin from its outer surface side with a fixing thread;
A third step of fixing the outer skin to the member by melting or softening the outer layer of the outer skin fixing yarn and integrating the adjacent outer layers together. Fixing method. As the outer thread fixing thread, a thread whose central axis is shifted from the central axis of the core part,
2. The outer skin fixing method according to claim 1, wherein in the second step, the outer skin is fastened by the outer skin fixing thread so that a side of the core portion on which the central axis is biased is the outer skin side. The outer thread fixing thread has a melting point of the first resin of m ₁ [° C.] and a melting point of the second resin of m ₂ [° C.]
The outer skin fixing method according to claim 1 or 2, wherein m ₁ -m ₂ satisfies a relationship of 10 or more. 4. The outer skin fixing method according to claim 1, wherein the melting point m ₁ of the first resin is 230 ° C. or higher.   5. The first resin according to claim 1, wherein the first resin is mainly composed of at least one of polyester, polyphenylene sulfide, polycarbonate, fluorine resin, aramid resin, polyether ether ketone, polyamideimide, and polyarylate. The outer skin fixing method according to any one of the above. The skin fixing method according to any one of claims 1 to 5, wherein a melting point m2 of the _second resin is 220 ° C or lower.   The outer skin fixing method according to any one of claims 1 to 6, wherein the second resin is mainly composed of at least one of polypropylene, polyethylene, polyamide and polystyrene. The melting point of the first resin and the melting point of the second resin in the outer thread fixing yarn are m ₁ [° C.] and m ₂ [° C.], respectively, and the heating temperature in the third step is T [° C.]. When
_{m 2 ≦ T ≦ m 2 +} (m 1 -m 2) skin fixing method according to any one of claims 1 to 7 satisfying × 0.9 the relationship. A flexible tube having a core material and an outer skin covering the outer periphery of the core material;
A flexible tube for an endoscope, which is provided at a distal end portion of the flexible tube portion and includes a core material and a curved portion having an outer skin covering the outer periphery of the core material,
The base end portion of the outer skin of the bending portion and the distal end portion of the outer skin of the flexible tube portion are formed by the method of fixing the outer skin according to any one of claims 1 to 8, or the core material of the bending portion or the flexible tube portion. A flexible tube for an endoscope which is fixed to a core material of the endoscope.   An endoscope comprising the flexible tube for an endoscope according to claim 9.

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