JP2011036576A - Flexible tube of endoscope - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a flexible tube of an endoscope which is constituted so as to be reduced in outer diameter, causes no deficiency in fixing strength of a helical tube and a cap, and has a stable quality. <P>SOLUTION: A counter-bored hole 10a into which the end part of an inside helical tube 11 is fitted and inserted, is formed at the end part of either end of the cqap 10 on the side of helical tubes 11 and 12, the end part of the inside helical tube 11 is fitted and inserted into the counter-bored hole 10a, the end surface of the outside helical tube 12 is brought into abutment on the end surface of the cap 10, and the outside spiral tube 12 and the cap 10 are welded (Lo) and fixed only at a position where the inside spiral tube 11 is present inside the abutment part of the outside spiral tube and the cap. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a flexible tube of an endoscope.

  In general, a flexible tube that sheathes an insertion portion of an endoscope, etc., is generally a metal inner / outer double spiral tube with a different winding direction disposed in an inner layer portion, and an end of the spiral tube is fixed to a base, In the middle layer, a mesh tube is disposed in a state where the outer surface of the spiral tube is covered, and the outer layer is formed of a flexible outer skin (for example, Patent Document 1).

JP2007-252560

  For example, as shown in FIG. 6, the end of the flexible tube 1 of the conventional endoscope as described in Patent Document 1 is in a countersink-shaped hole 99 formed at the end of the base 90. The end portions of the inner and outer double spiral tubes 91 and 92 and the end portion of the mesh tube 93 were inserted and fixed together. For this reason, the outer diameter of the base 90 is increased, which hinders the formation of the flexible tube 1 in a thin endoscope or the like. Reference numeral 2 denotes a bending portion that is bent by remote operation.

  Therefore, for example, as shown in FIG. 7, the end surfaces of the inner and outer double spiral tubes 91 and 92 are brought into contact with the base 90 and fixed to each other by laser welding or the like, and the mesh tube 93 is fixed to the outer surface of the base 90. If the structure to be taken is taken, the outer diameter of the part can be formed thinner than before. Regarding such a configuration, the applicant of the present application has already applied for a patent (Japanese Patent Application No. 2008-114960).

  However, with such a configuration, for example, as shown in FIG. 8, when laser welding the inner spiral tube 91 to the base 90 first, even a slight gap is formed between the end surface of the inner spiral tube 91 and the end surface of the base 90. If there is, there is a possibility that the laser beam Li will escape from the gap and the welded state will be insufficient, resulting in insufficient fixing strength.

  An object of the present invention is to provide a flexible tube of an endoscope that can be configured to have a small outer diameter and that does not cause insufficient fixing strength between a spiral tube and a base and has a stable quality.

  In order to achieve the above object, the flexible tube of the endoscope of the present invention has a substantially cylindrical metal base in which a metal inner and outer double spiral tube having different winding directions is arranged in the inner layer portion. In the flexible tube of the endoscope in which the ends of the inner and outer double spiral tubes are fixed by welding, the end of the inner spiral tube is at the end on the spiral tube side of both ends of the base. A counterbored hole to be inserted is formed, and an end of the inner spiral tube is inserted into the countersink-shaped hole, and an end surface of the outer spiral tube is brought into contact with an end surface of the base, and the outer spiral tube The base and the base are welded and fixed only at the position where the inner spiral tube exists inside the contact portion.

  The inner spiral tube and the base may be welded and fixed from the outer peripheral surface side of the base with the end of the inner spiral tube inserted into the counterbored hole. It may be approximately the same size as the inner and outer diameters of the double helical tube.

  According to the present invention, the end of the inner spiral tube is fitted into the counterbored hole formed at the end on the spiral tube side of both ends of the cap, and the end surface of the outer spiral tube is the end surface of the cap. The outer spiral tube and the base are welded and fixed only at the position where the inner spiral tube exists on the inner side of the abutting portion, so that the outer diameter can be reduced. In addition, it is possible to obtain a flexible tube of an endoscope with a stable quality that does not cause insufficient fixing strength between the spiral tube and the base.

It is side surface sectional drawing of a part of flexible tube of the endoscope which concerns on the Example of this invention. It is a side view which shows an example of the whole structure of an endoscope. It is a perspective view of the spiral tube used for the flexible tube of the endoscope which concerns on the Example of this invention. It is side surface sectional drawing in the manufacturing process of the flexible tube of the endoscope which concerns on the Example of this invention. It is side surface sectional drawing in the manufacturing process of the flexible tube of the endoscope which concerns on the Example of this invention. It is side surface sectional drawing of a part of flexible tube of the conventional endoscope. It is side surface sectional drawing of a part of flexible tube of the conventional endoscope. It is side surface sectional drawing in the manufacturing process of the flexible tube of the conventional endoscope.

Embodiments of the present invention will be described below with reference to the drawings.
FIG. 2 shows an example of the overall configuration of the endoscope. The insertion portion inserted into the body has a distal end portion in which a bending portion 2 is connected in series to the distal end of the flexible tube 1 and an observation window is arranged. The main body 3 is configured to be attached to the tip of the bending portion 2.

  The flexible tube 1 is bent freely along a body duct or the like to be inserted, but the bending portion 2 can be bent in a predetermined direction by a remote operation from the operation unit 4 connected to the proximal end of the flexible tube 1. Can be curved at any angle.

  A bending operation wire 5 connected to the distal end portion of the bending portion 2 is inserted into the flexible tube 1. The bending operation wire 5 is moved forward and backward by a bending operation knob 6 disposed in the operation unit 4, and the bending unit 2 bends as shown by a two-dot chain line by an angle corresponding to the pulling amount of the bending operation wire 5. .

FIG. 1 shows a connecting portion between a flexible tube 1 and a bending portion 2 of an endoscope according to an embodiment of the present invention.
The bending portion 2 includes a plurality of articulated rings 21 rotatably connected by rivets 22 or the like, a mesh tube 23 covered on the outer surface thereof, and a rubber coated tube 24 rich in elasticity on the outer surface of the mesh tube 23. Is covered.

  The flexible tube 1 is formed by coating a mesh tube 13 formed by braiding metal fine wires on the outer surfaces of metal spiral tubes 11 and 12, and forming the mesh tube 13 on a flexible synthetic resin material on the outer surface. The outer skin 14 is covered.

  As shown in FIG. 3, the spiral tubes 11 and 12 are composed of inner and outer double spiral tubes 11 and 12 having different winding directions, and each of the spiral tubes 11 and 12 is a metal strip having a constant width. It is formed by spirally winding a material with a constant diameter.

  Returning to FIG. 1, reference numeral 10 denotes a metal base provided at the distal end portion of the flexible tube 1. The rear end joint ring 21E is applied to the front end surface of the base 10 and is connected and fixed by welding, whereby the flexible tube 1 and the bending portion 2 are connected.

  Further, the side surface on the distal end side of the guide coil 50 formed of the closely wound coil for guiding the bending operation wire 5 in the flexible tube 1 is fixed to the inner peripheral surface of the base 10 or the joint ring 21E at the end by silver brazing or the like. Has been. Other portions of the guide coil 50 are not fixed in the flexible tube 1.

  The base 10 is formed in a substantially cylindrical shape having substantially the same dimensions as the inner and outer diameters of the spiral tubes 11 and 12 whose inner and outer diameters are double. However, the inner peripheral portion on the rear end side of the base 10 (that is, the end portion on the spiral tube 11, 12 side) is a countersink-shaped hole 10 a whose inner diameter is partially larger than other portions.

  Then, the end of the inner spiral tube 11 is fitted and fixed in the counterbored hole 10a, and the front end surface of the outer spiral tube 12 is brought into contact with the rear end surface of the base 10, so that the outer spiral tube 12 and The base 10 is fixed to each other at the contact portion. As a result, the outer diameter of the flexible tube 1 at that portion can be formed thin.

  The inner spiral tube 11 and the outer spiral tube 12 are individually fixed to the base 10 by laser welding. Li and Lo shown in FIG. 1 indicate laser beams when laser welding is performed. However, the laser beams Li and Lo are irradiated before the mesh tube 13 and the outer skin 14 are assembled.

  FIG. 4 shows a state when the inner spiral tube 11 is laser welded to the base 10, and the outer peripheral surface side of the base 10 with the end portion of the inner spiral tube 11 fitted in the countersink-shaped hole 10 a. By irradiating with the laser beam Li, the inner spiral tube 11 and the base 10 can be firmly welded and fixed without energy loss.

  FIG. 5 shows a state in which the outer spiral tube 12 is laser welded to the base 10, and the laser beam Lo is outwardly applied to the abutting portion between the front end surface of the outer spiral tube 12 and the rear end surface of the base 10. It is irradiated from.

  Before that, since the inner spiral tube 11 is welded and fixed to the base 10, the inner spiral tube 11 is inside the irradiation position of the laser beam Lo when the outer spiral tube 12 and the base 10 are welded. Existing.

  Therefore, even if there is a slight gap between the front end surface of the outer spiral tube 12 and the rear end surface of the base 10, the laser beam Lo rebounds against the inner spiral tube 11, and the inner spiral tube 11 and the outer spiral tube adjacent thereto are repelled. Since 12 and the base 10 are welded together, the outer spiral tube 12 and the base 10 can be firmly welded and fixed without energy loss.

  However, the inner spiral tube 11 wound spirally does not exist at the inner position of the rear end face of the base 10 depending on the location. Therefore, only the portion where the inner spiral tube 11 is located inside the rear end surface of the base 10 is irradiated with the laser beam Lo, and the outer spiral tube 12 is welded and fixed to the base 10.

  Returning to FIG. 1, the outer periphery of the inner and outer double spiral tubes 11, 12 whose end portions are fixed to the base 10 is covered with the mesh tube 13, and the end of the mesh tube 13 is outside the base 10. The outer periphery of the spiral tube 12 is fixed by soldering, and the outer periphery of the mesh tube 13 is covered with an outer skin 14 by means such as extrusion.

  The end portion of the outer skin 14 of the flexible tube 1 and the end portion of the covering tube 24 of the bending portion 2 are tightly fixed and fixed from the outer periphery with binding yarns 15 and 25, respectively, and bonded so as to wrap the binding yarns 15 and 25. Agent Q is applied all around.

DESCRIPTION OF SYMBOLS 1 Flexible tube 10 Base 10a Counterbored hole 11 Inner spiral tube (inner spiral tube)
12 Outer spiral tube (outer spiral tube)
Li, Lo laser beam

Claims (3)

A metal inner / outer double spiral tube having a different winding direction is arranged in the inner layer portion, and the ends of the inner / outer double spiral tube are fixed to a substantially cylindrical metal base by welding. In the flexible tube of the endoscope,
A counterbored hole into which the end of the inner spiral tube is fitted is formed at the end on the spiral tube side of both ends of the base, and the end of the inner spiral tube is inserted into the countersunk hole. Is inserted, and the end surface of the outer spiral tube is brought into contact with the end surface of the base, and the outer spiral tube and the base are the abutting portions, and the inner spiral tube exists inside thereof. A flexible tube for an endoscope, which is welded and fixed only at a position.   The inner spiral tube and the base are welded and fixed from the outer peripheral surface side of the base in a state where an end of the inner spiral tube is inserted into the counterbored hole. Flexible tube of endoscope.   The flexible tube for an endoscope according to claim 1 or 2, wherein an inner and outer diameter of the base is approximately the same as an inner and outer diameter of the inner and outer double spiral tube.

Images