JPH1099263A - Flexible tube for endoscope - Google Patents

Abstract

PROBLEM TO BE SOLVED: To ensure the connection strength between a connection member and a flexible tube without having to enlarge the outside diameter of an insertion part. SOLUTION: This flexible tube is designed in such a manner that a net pipe 23 which is made by knitting metal strands is arranged at the outer circumference of an inner layer tube 22 made from a flexible resin, and an outer layer tube 24 made from a flexible resin is arranged at the outer circumference of the net pipe 23. A bent side base 25 is fitted to the end of the flexible tube, the outer layer tube 24 is removed from the fitted part, and a cover material 27 is arranged at this part.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a flexible tube for an endoscope used for an insertion portion or the like, and more particularly to a connection structure for a bending portion.

[0002]

2. Description of the Related Art Generally, a flexible tube of an endoscope insertion portion has strength for protecting built-in components such as an image guide fiber and a light guide fiber, and flexibility required at the time of insertion or observation. Various properties such as tensile resistance and follow-up properties are required, and at the same time, it is required to reduce the outer diameter as much as possible by reducing the thickness of the flexible tube in order to improve the insertion into the body cavity. ing.

In response to such a demand, Japanese Patent Laid-Open No.
As disclosed in Japanese Patent Application Laid-Open No. 95434, a flexible tube in which a flexible resin is integrally formed with a mesh tube formed by braiding a metal wire having a flat cross section has been considered. A bending portion for directing the distal end of the endoscope in a predetermined direction is connected to the distal end side of the flexible tube.
Normally, a method of connecting the flexible tube and the bending portion via a hard connecting member made of metal or hard resin is used as a joint. In fixing the flexible tube to the connecting member, the flexible tube is fixed with an adhesive or solder.

However, if the flexible tube integrally formed with a flexible resin is fixed to the flexible tube having the above-described structure, that is, a rope-shaped tube formed by knitting a metal element wire, it is difficult to heat the solder. The generated heat melts the flexible resin, exposing the ends of the strands of the mesh tube, or the thickness of the flexible resin becomes uneven, so that the cross section of the insertion portion does not become substantially circular and the insertability is improved. Deteriorate. For this reason, a method is generally adopted in which the connecting member is fitted to the inner peripheral surface or the outer peripheral surface of the connecting member, and is bonded and fixed.

[0005]

However, even in such a connection structure, the following disadvantages are caused by a so-called bending operation for turning the bending portion in a predetermined direction or an operation for putting the flexible tube into and out of the body cavity. Occurs. In the case where the connecting member is fitted and fixed to the outer peripheral surface of the flexible tube by bonding, when a bending force or a pulling force acts on the vicinity of the connection portion by a bending operation or the like,
The flexible tube is elongated, the inner diameter of the flexible tube is reduced, and the flexible tube is separated from the connecting member. In general, since the adhesive has a weak strength against the peeling force, the above-described structure peels off without obtaining a sufficient adhesive strength required for an endoscope.

Further, in the case where the connecting member is fitted to the inner peripheral surface of the flexible tube and bonded and fixed, even if the inside of the flexible tube is reduced, the connecting member is disposed inside the flexible tube so that the flexible tube is peeled off. However, when a bending force or the like is applied, the tip of the metal wire may break through the outer layer made of resin and be exposed to the outside. Therefore, as means for solving such a problem, the inner peripheral surface of the flexible tube is fitted to the connecting member,
Further, a method of providing a rigid cover member on the outer peripheral surface of the flexible tube of the fitting portion can be considered. According to this method, it is possible to prevent the flexible tube from peeling off from the connecting member and to prevent the distal end of the metal wire in the flexible tube from being exposed to the outside, but the outer diameter of the insertion portion of the endoscope is not affected. It becomes thicker as needed, and the insertability of the endoscope into the body cavity becomes worse.

In the case where the connecting member is fitted to the inner peripheral surface of the flexible tube and fixed by bonding, it is possible to prevent the tip of the metal wire from being exposed to the outside by increasing the thickness of the outer layer. However, it is necessary to increase the thickness considerably, which is not practical, and does not solve the problem. The present invention has been made in view of such circumstances, and an object of the present invention is to provide a flexible tube for an endoscope that can secure the connection strength between the connecting member and the flexible tube without increasing the outer diameter. To provide.

[0008]

To achieve the above object, a flexible tube for an endoscope according to the present invention has an outer layer made of a flexible resin formed on an outer surface of a braided tube made of a metal wire. And a base connected to the end of the flexible tube. The reticulated tube is arranged on the outer periphery of the base and a hard portion is formed on the outer peripheral surface of the reticulated tube.

Here, a flexible tube in which an outer layer made of a flexible resin is formed on the outer surface of a mesh tube formed by knitting metal wires is a tube in which the flexible resin is formed on the outer peripheral surface of the mesh tube. It suffices if it is sufficient, and more specifically, a mesh tube and an outer layer made of a flexible resin may be integrally formed, or an inner layer may be formed on the inner periphery of the mesh tube. Further, the base disposed at the end of the flexible tube refers to a base for connecting the flexible tube to another member, and the base and the other member may be integrally formed. With this configuration, the flexible tube is prevented from peeling off from the base.

[0010] The hard portion provided on the outer peripheral surface of the braided tube means a portion for preventing the tip of the metal wire of the braided tube from being exposed to the outside. Specifically, a hard member such as an independent metal, a material in which only the tip of the outer layer of the flexible tube is formed of a hard resin, or a curable adhesive used for the tip of the flexible tube Including.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the drawings. (First Embodiment) FIGS. 1 to 5 show a first embodiment of the present invention. FIG. 2 is a schematic view showing the overall appearance of the endoscope 1. As shown in FIG. The insertion section 3 is connected to the distal end side of the operation section 2, and the light guide cable 4 is connected to the proximal end side.
The insertion portion 3 is configured by connecting the distal end component 5, the bending portion 6, and the flexible tube 7 in this order from the distal end. Inside the insertion section 3, built-in components such as an image guide fiber, a light guide fiber, an air supply pipe, a water supply pipe, and a suction pipe are arranged. The image guide fiber is guided to an eyepiece section 8 provided in the operation section 2. The light guide fiber is guided through the operation unit 2 into the light guide cable 4, and is connected to a lighting device (not shown) via the connector 9. Further, the air supply pipe, the water supply pipe, and the suction pipe are guided into the light guide cable 4 through the operation unit 2.

FIG. 1 is a sectional view of the distal end of the endoscope insertion section 3. The distal end component 5 includes a forceps insertion conduit 10, an objective optical system 1,
1 and the tip of a light guide fiber (not shown) are arranged on the fixed frame 12 and are connected to the bending portion 6. At the base end side of the objective optical system 11, an image guide fiber 13 inserted through the operation unit 2 and guided to the eyepiece unit 8 is arranged, and an image obtained by the objective optical system 11 is transmitted to the eyepiece unit 8. Has communicated.

The bending portion 6 has a plurality of node rings 14 rotatably connected to each other by rivets or the like. A bending wire (not shown) is inserted through a wire guide 15 provided inside the flexible tube 7 to operate the operating portion. It extends to an angle knob 16 provided on 2. The distal end of the endoscope 1 is directed in a predetermined direction by remote control using the angle knob 16.

The outer periphery of the node ring 14 is covered with a highly elastic outer tube 17 made of polyurethane resin, fluorine rubber, or the like. The peripheral surface is adhesively fixed. The operation section side end of the outer tube 17 is covered except for the operation section side end of the node ring 18 disposed closest to the operation section.

In order to prevent water or the like from penetrating into the endoscope from the outside, a thread 1
9 is tied up, and an adhesive 20 is applied on the tied-up portion. As shown in FIG. 3, the thread 19 is formed by knitting a plurality of tungsten wires 21 into a thread shape. Tungsten has excellent spreadability and can produce a fine thread, and in this embodiment,
The diameter of the thread 19 is made about 0.03 mm.

Generally, a nylon thread is used for the binding, but the nylon thread has a low tensile strength and may be broken during the binding operation, resulting in poor workability. In order to obtain sufficient tensile strength, the diameter of the nylon thread must be increased, compared to the tungsten thread,
Approximately ten times the thickness is required. In the present embodiment, a tungsten thread is used as the binding thread, and the efficiency of the binding operation is improved, and the outer diameter of the insertion portion can be reduced as much as possible.

Further, since a plurality of tungsten strands 21 are knitted into a thread shape, when the adhesive 20 is applied after binding, the adhesive 20 enters the stitches to increase the bonding area and increase the bonding strength. can do. In particular, in the case where the adhesive strength is not required, it is not necessary to specially knit the element wire 21. Depending on the situation to be implemented, a tungsten single wire or a tungsten element wire is knitted. All you have to do is select one of the threads. Further, the thickness of the line may be selected according to the required strength or the like.

Next, a connection structure between the bending portion 3 and the flexible tube 7 will be described. The bending portion 3 and the flexible tube 7 are connected via a bending portion side base 25 as shown in FIG. The flexible tube 7 includes an inner tube 22 made of a flexible resin such as nylon, polytetrafluoroethylene, polyethylene, and polyurethane, and a mesh tube 2 on the outer periphery of the inner tube 22.
The outer tube 2 made of the same flexible resin as the inner tube 22 is provided around the outer periphery of the mesh tube 23.
4 are arranged and these are integrally formed. As shown in FIG. 4, the mesh tube 23 is formed by braiding a metal wire having a flat cross section.

The curved portion side base 25 is made of a hard material such as a metal or a hard resin, and has a stepped cylindrical shape having a stepped portion 26. The end of the curved portion base 25 with the smaller outer diameter is fitted and bonded to the inner peripheral surface of the distal end of the flexible tube 7. The metal forming the outer tube 24 is peeled off and removed from the distal end side of the fitting portion between the curved portion side base 25 and the flexible tube 7, and the metal is covered so as to cover the entire exposed net tube 23. Alternatively, a cylindrical cover member 27 made of hard resin is directly bonded.

The distal end of the cover member 27 is
5 is in contact with the step 26. In the vicinity of the base end of the fitting portion, there are some steps, but the outer tube 2
The outer diameters of the cover member 27, the bending portion side base 25, and the bending portion 6 are substantially equal to each other.
2. The inner diameters of the bending portion side ferrule 25 and the node ring 17 are also substantially equal.

The length of the cover member 27 is
The bending portion side base 25 and the cover member 27 are set so as not to be longer than the fitting portion between the bending portion side base 25 and the bending portion side base 25. Hold the flexible tube 7. The connection between the flexible tube 7 and the bending portion side base 25 is performed in the following procedure. First, a tapered member or the like is pushed into the inside of the flexible tube 7 so that the inner diameter of the distal end portion of the flexible tube 7 is curved so that the flexible tube 7 can be easily fitted to the bending portion side base 25. Part side base 2
5 until it is approximately equal to the outside diameter. Thereafter, the resin of the outer layer tube 24 on the distal end side of the flexible tube 7 is peeled and removed over the entire circumference as long as it does not become longer than the length of the cover member 27. Next, the cover member 27 is bonded and fixed to the distal end of the flexible tube 7 so that the mesh tube 23 is not exposed. At this time, the metal wire of the mesh tube 23 protruding from the cover member 27 is cut off in accordance with the end face of the cover member 27. Finally, the bending portion side base 25 is fitted and fixed to the inner peripheral surface of the flexible tube 7 which has been expanded in advance.

The connection between the flexible tube 7 and the operation section 2 is performed via an operation section side base 28 shown in FIG. A pipe 29 made of metal or hard resin is fitted and adhesively fixed to the inner peripheral surface of the flexible tube 7 so as to protrude from the base end of the flexible tube 7 toward the operation unit. Is adhered and fixed to the operation unit side base 28. The distal end portion of the operation section side base 28 is adhesively fixed to the outer peripheral surface of the flexible tube 7. An adhesive reservoir 3 where the resin of the outer tube 24 of the flexible tube 7 is partially peeled off is provided at an adhesive portion between the flexible tube 7 and the operation unit side base 28.
The flexible tube 7 and the operation section side base 28 are more securely bonded and fixed by filling the adhesive pool 30 with the adhesive 31.

Next, the operation and effect of this embodiment will be described. According to the present invention, since the bending portion side base 25 is fitted and fixedly adhered to the inner peripheral surface on the distal end side of the flexible tube 7, a bending force or the like acts on the vicinity of the fitting portion by a bending operation or the like, so that the flexible tube 7 becomes flexible. Tube 7
Is extended and the inner diameter of the flexible tube 7 is reduced, so that the tightening force with the bending portion side base 25 is increased. As a result, the flexible tube 7 and the bending portion side base 25 are more securely fixed. Therefore, the flexible tube 7 has a structure that is difficult to peel off from the bending portion side base 25.

Further, at the fitting portion between the flexible tube 7 and the curved portion side base 25, the resin forming the outer tube 24 is peeled and removed over the entire circumference, and the cover member 27 is disposed at that portion. In addition, the tip of the metal wire of the mesh tube 23 is not exposed. Further, since the resin of the outer tube 24 is peeled off, the endoscope insertion portion 3 does not become thick even if the cover member 27 is disposed.

Further, since the outer diameters of the flexible tube 7, the cover member 27, the bending portion side base 25, and the bending portion 6 are substantially equal, the endoscope is hardly caught and the insertability of the endoscope is good. Then, the flexible tube 7, the bending portion side base 25 and the node ring 1
Since the inner diameter of 7 is also approximately the same size, it is easy to insert the built-in object into the insertion portion when assembling the endoscope, and the workability is good.

As described above, the method of connecting the bending portion side base 25 to the flexible tube 7 does not require any special technique, and can be easily fixed to the flexible tube 7.
The present embodiment is not limited to the above-described configuration. For example, in the flexible tube 7, the inner tube 22, the mesh tube 23, and the outer tube 24 may not be integrally formed. If necessary, a flexible tube having a double structure of the mesh tube 23 and the outer tube 24 may be used. The cross section of the metal wire of the mesh tube 23 is not limited to a flat shape, and may be, for example, a circle or an ellipse.

The bending portion side base 25 may be formed integrally with the node ring 17. Also, the cover member 27
Instead, a flexible outer tube in which only the fitting portion, that is, the tip portion is formed of a hard resin may be used, and the entire fitting portion from which the outer tube 24 is peeled is hardened. May be arranged in place of the cover member 27.

(Second Embodiment) Next, a second embodiment will be described with reference to FIG. In the second embodiment,
Since most of them are the same as the first embodiment, only different points will be described, and the same components will be denoted by the same reference numerals and description thereof will be omitted. FIG. 6 is a cross-sectional view showing a connection state between the flexible tube 7 and the bending portion 6 according to the second embodiment.

The operating portion side of the node ring 32 disposed closest to the operating portion of the bending portion has a stepped cylindrical shape. The curved portion side base 33 has a cylindrical shape made of a hard material such as metal or hard resin. The distal end of the bending portion side base 33 is fitted and adhered to the inner circumference of the end having the larger inner diameter of the node ring 32, and the outer circumference of the operating portion side end of the bending portion side base 33 is The flexible tube 7 is fitted and adhered. The metal forming the outer tube 24 is peeled off and removed from the distal end side of the fitting portion between the curved portion base 33 and the flexible tube 7, and the metal is covered so as to cover the entire exposed net tube 23. Alternatively, a cylindrical cover member 34 made of hard resin is directly bonded.

The length of the cover member 34 is set so as not to be longer than the length of the fitting portion between the flexible tube 7 and the bending portion side base 33. The outer tube 24, the cover member 3
The outer diameters of the inner tube 4, the bending portion side base 33, and the node ring 32 are substantially equal in the outer diameter of the bending portion 4 and the bending portion 6.
Have substantially the same inner diameter.

The operation and effects of the present embodiment are similar to those of the first embodiment.
Are fitted and bonded, a bending force or a pulling force acts on the vicinity of the connection portion by a bending operation or the like, so that the flexible tube 7 is expanded and the inner diameter of the flexible tube 7 is reduced. 7 has a structure that is difficult to peel off from the bending portion side base 33. Further, at the fitting portion between the flexible tube 7 and the bending portion side base 33, the resin forming the outer layer tube 24 is peeled off and removed over the entire circumference, and the cover member 34 is disposed at that portion.
3 does not expose the cover member 34 and the resin of the outer tube 24 is peeled off and removed, so that the endoscope insertion portion 3 is made thick even when the cover member 34 is disposed. Nothing.

Further, since the outer diameters of the flexible tube 7, the cover member 34 and the node ring 32 are substantially equal, the insertability of the endoscope is good. Further, since the inner diameter of the inner tube 22 is substantially equal to the inner diameter of the bending portion side base 33 and the node ring 32, the built-in material can be smoothly inserted into the insertion portion even when the built-in material is inserted. Good.

The present invention is not limited to the embodiment described above, and it goes without saying that various modifications can be made without departing from the scope of the present invention. For example, the connection between the flexible tube and the operation unit, the connection between the light guide cable and the operation unit, or the connection between the light guide cable and the connector can be performed. (Supplementary note) According to the technical contents described above, various configurations as described below can be obtained.

(Additional Item 1) In a flexible tube for an endoscope having a curved portion in which an end portion of an outer tube made of a flexible resin is tightly bound by a thread, the thread for the binding is metal. A flexible tube for an endoscope, comprising a single wire made of stainless steel. (Conventional technology of supplementary item 1 and problems to be solved) Conventionally, an endoscope bending portion has a plurality of node rings connected rotatably to each other with rivets or the like. A highly elastic outer tube made of rubber or the like is covered, and the outer peripheral surface of the node ring and the inner peripheral surface of the outer tube are adhesively fixed. Further, in order to more securely fix the outer tube, the outer periphery of both ends of the outer tube is tied up with a nylon thread and an adhesive is applied.

However, nylon yarns have a low tensile strength and may break during the binding operation, resulting in poor workability. Further, since the tensile strength is weak, the yarn diameter must be increased, resulting in an increase in the insertion portion of the endoscope. Supplementary note 1 is made in view of such circumstances, and an object thereof is to provide a watertight flexible endoscope tube that can be easily bound without increasing the outer diameter of the binding portion. It is in.

(Effect of Additional Item 1) Compared with nylon yarn, a metal single wire has a high tensile strength, and is hard to be cut even when the end of the outer tube is tied up, so that the work is good. Also, since the tensile strength is higher than nylon thread, it can be made thinner than nylon thread, and the outer diameter of the binding part can be made smaller. Good mirror insertion.

(Additional Item 2) The flexible tube for an endoscope according to Additional Item 1, wherein the binding yarn is formed by knitting a metal wire into a thread shape. (Effect of Supplementary Item 2) In addition to the effect of Supplementary Item 1, since the metal wire is knitted into a thread shape, the adhesive penetrates into the stitch to expand the bonding area, and the outer skin tube becomes more watertight. Can be adhesively fixed.

(Additional Item 3) The additional item 1, wherein the material of the binding yarn is tungsten.
4. A flexible tube such as an endoscope according to claim 2. (Effect of Additional Item 3) Tungsten has a higher tensile strength than nylon. Tungsten has good spreadability and can produce an ultrafine yarn. Therefore, the strength required by the endoscope can be obtained with a thickness of about one tenth of that of the nylon thread. In addition, since the diameter of the tungsten thread is smaller than that of the nylon thread, the thread is cut into the outer tube by being tightly bound. Therefore,
The outer diameter of the binding portion can be made smaller than that of the nylon thread, and an endoscope having a smaller outer diameter of the insertion portion can be provided.

In the case of binding, whether to use a single wire made of tungsten or a wire formed by knitting a tungsten elemental wire may be selected depending on the use situation.

[0040]

According to the flexible tube for an endoscope of the present invention, since the braided tube is arranged on the outer periphery of the base and the hard portion is formed on the outer peripheral surface of the braided tube, the bending operation of the curved portion is performed. By such means, the flexible tube does not peel off from the base, and the metal wire of the mesh tube inside the flexible tube is not exposed to the outside.

[Brief description of the drawings]

FIG. 1 is a sectional view of a distal end of an insertion portion according to a first embodiment of the present invention.

FIG. 2 is an outline view of the endoscope according to the first embodiment of the present invention.

FIG. 3 is an external view showing a state in which a tungsten wire for binding an outer tube of a curved portion is knitted into a thread shape.

FIG. 4 is an external view of a flexible tube according to the first embodiment of the present invention.

FIG. 5 is a sectional view of a proximal end of an insertion portion according to the first embodiment of the present invention.

FIG. 6 is a cross-sectional view illustrating a connecting portion between a flexible tube and a bending portion according to a second embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Endoscope 2 Operation part 3 Insertion part 6 Bending part 7 Flexible tube 17 Outer tube 18 Articulation ring (most operation part side) 19 Thread 21 Element wire 22 Inner tube 23 Reticulated tube 24 Outer tube 25 Curved part side cap 26 Step Part 27 cover member 32 node ring (most operation part side) 33 curved part side base 34 cover member

Claims (1)

[Claims] 1. An endoscope having a flexible tube in which an outer layer made of a flexible resin is formed on the outer surface of a braided tube formed by knitting metal wires, and a base connected to an end of the flexible tube. A flexible tube for an endoscope, wherein the reticulated tube is arranged on an outer periphery of the base and a hard portion is formed on an outer peripheral surface of the reticulated tube.