JP2011036577A - Flexible tube of endoscope - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a flexible tube of an endoscope which is excellent in durability of a soldered part to which the end part of a net tube is fixed, hard to damage even if large tension or twist force acts thereon, and capable of being reduced in outer diameter at the soldered part. <P>SOLUTION: In the flexible tube of the endoscope constituted so that the outer surface of a helical tube 12 is covered with the net tube 13 and the end part of the helical tube 12 is fixed to a cap 10 formed into an almost cylindrical shape at a spot welded part Po, while the end part of the net tube 13 is fixed to the surfaces of the cap 10 and the helical tube 12 by soldering in a region covering the spot welding part Po and the periphery thereof, the spot welding part Po is formed in a state locally protruded or recessed with respect to the surfaces of the cap 10 and the helical tube 12, and the protruded part of the spot welding part Po is engaged with the meshes of the net tube 13 or the solder of the soldered part H protrudes to be engaged with the recessed part of the spot welding part Po. <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 composed of a metal inner and outer double spiral tube having different winding directions, and an end portion 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. 9, 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 control.

  Therefore, for example, as shown in FIG. 10, the end surfaces of the inner and outer double helical 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. By comprising so, 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).

  The end of the outer spiral tube 92 is fixed to the base 90 by welding. P is the weld. The end portion of the mesh tube 93 is fixed to the surface of the base 90 and the spiral tube 92 by soldering in the welded portion P and its peripheral region after finishing the welded portion P to a smooth surface with a file or the like.

  However, the flexible tube 1 of the endoscope having such a configuration has a mesh shape when a large tension in the axial direction is applied when the endoscope is used, or when a large torsional force is applied in the direction around the axis. The soldering that fixes the end of the tube 93 is removed, causing the flexible tube 1 to be damaged.

  The present invention is excellent in the durability of the soldering portion for fixing the end portion of the mesh tube, is not easily damaged even when a large tension or torsional force is applied, and the outer diameter of the portion is narrowed. An object of the present invention is to provide a flexible tube for an endoscope.

  In order to achieve the above object, the flexible tube of the endoscope of the present invention is formed in a substantially cylindrical shape by a mesh tube formed by braiding metal fine wires being covered on the outer surface of a metal spiral tube. The end of the spiral tube is fixed to the metal base by spot welding, and the end of the mesh tube is fixed to the surface of the base and the spiral tube by soldering in the area covering the spot weld and its periphery. In the endoscope flexible tube provided, the spot welded portion is formed so as to be locally convex with respect to the base and the surface of the spiral tube, and the convex portion engages with the mesh of the mesh tube. It is what.

  It should be noted that spot welded portions are provided at a plurality of locations, and in each of the portions, the spot welded convex portions may be engaged with the meshes of the mesh tube, and the surface of the base is fixed to the spiral tube. Convex portions may be formed on the non-contributing portion by the same process as spot welding, and the convex portions may be engaged with the meshes of the mesh tube.

  In addition, the flexible tube of the endoscope of the present invention is such that the spot welded portion is formed to be locally recessed with respect to the base and the surface of the spiral tube, and the solder of the soldering portion protrudes into the recessed portion. It may be engaged, and spot welds may be provided at a plurality of locations, and in each part, the solder of the soldering part may be protruded and engaged with the spot weld recess.

  According to the present invention, the spot weld is formed so as to be locally convex or concave with respect to the base and the surface of the spiral tube, and the convex portion engages the mesh of the mesh tube, or Because the solder of the soldering part protrudes and engages with the concave part, the durability of the soldering part that fixes the end of the mesh tube is excellent, and it is damaged even if a large tension or torsional force is applied. Difficult durability can be obtained.

It is a partial expanded side sectional view of the flexible tube of the endoscope concerning the 1st example of the present invention. It is a side view which shows an example of the whole structure of an endoscope. It is side surface sectional drawing of a part of flexible tube of the endoscope which concerns on 1st Example of this invention. It is a perspective view of the spiral tube used for the flexible tube of the endoscope which concerns on 1st Example of this invention. It is a partial expanded view of the flexible tube of the endoscope which concerns on 1st Example of this invention. It is a partial exploded side view of the modification of the flexible tube of the endoscope concerning the 1st example of the present invention. It is side surface sectional drawing of a part of flexible tube of the endoscope which concerns on 2nd Example of this invention. It is a partial expanded side sectional view of the flexible tube of the endoscope concerning the 2nd example of the present 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.

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

  A bending operation wire 5 connected to the distal end of the bending portion 2 is inserted into the flexible tube 1. The bending operation wire 5 is advanced and retracted 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. 3 shows a connecting portion between the flexible tube 1 and the bending portion 2 of the endoscope according to the first embodiment of the present invention.
The bending portion 2 includes a plurality of articulated wheels 21 rotatably connected by rivets 22 or the like, a mesh tube 23 is covered on the outer surface, and the outer surface of the mesh tube 23 is a rubber-coated tube 24 having high elasticity. 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. 4, 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. 3, 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 whose inner and outer diameters substantially coincide with the inner and outer diameters of the double spiral tubes 11 and 12. However, the portion near the rear end of the base 10 is partially formed with an outer diameter smaller than that of the other portion so as to be fitted into the outer spiral tube 12.

  FIG. 1 is an enlarged view of a connecting portion between the flexible tube 1 and the bending portion 2. The inner spiral tube 11 has a front end surface abutted against the rear end surface of the base 10, and the abutting surface is fixed to the base 10 by spot welding such as laser welding. Pi is the spot welds.

  The outer spiral tube 12 is fitted on the outer peripheral portion (that is, the outer diameter is smaller than the other portion) near the rear end of the base 10 in the vicinity of the most distal end, and the front end surface of the outer spiral tube 12 is the base 10. Are attached to the base 10 by spot welding such as laser welding. Po is the spot weld.

  The mesh tube 13 is covered on the outer circumferential surface over the entire length of the outer spiral tube 12, and the end of the mesh tube 13 is formed in the region covering the spot welded portion Po between the outer spiral tube 12 and the die 10 and its periphery. 10 and the outer surface of the outer spiral tube 12 are fixed by soldering. H shown in FIG. 1 is the range of the soldering portion. With such a configuration, the outer diameter of the flexible tube 1 at that portion can be formed thin.

  The spot welded portion Po between the outer spiral tube 12 and the base 10 is formed so as to be locally convex with respect to the surface of the base 10 and the surface of the outer spiral tube 12. That is, the small spot welded portion Po is raised from the surface of the base 10 and the surface of the outer spiral tube 12.

  And the convex part of the spot welding part Po is engaged in a state of fitting into the mesh of the mesh tube 13. FIG. 5 illustrates an example of the state of engagement of the spot welded portion Po with the mesh of the mesh tube 13, and the convex portions of the spot welded portion Po provided at a plurality of locations are the mesh tube 13 at each portion. It fits into the mesh of the mesh. However, the engagement state can take other modes.

  In this way, the spot welded portion Po formed so as to be locally convex with respect to the surface of the base 10 and the surface of the outer spiral tube 12 is fitted into the mesh of the mesh tube 13. By engaging with each other, the soldered portion H does not come off even if a large tension or torsional force is applied to the mesh tube 13 when the endoscope is used, and the flexible tube 1 is damaged. It is difficult to obtain excellent durability.

  Returning to FIG. 3, 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 fastened from the outer periphery by tightness yarns 15 and 25, respectively. The adhesive Q is applied to the entire circumference so as to wrap the film.

  In addition, as shown in FIG. 6, a spot welded portion is obtained by performing laser irradiation treatment on the surface of the base 10 that does not contribute to the fixation with the outer spiral tube 12 in the same manner as the spot welded portion Po. A convex portion Po ′ similar to Po may be formed, and the convex portion Po ′ may be engaged in a state of fitting into the mesh of the mesh tube 13. By doing so, the durability of the soldering portion H is further increased.

FIG. 7 shows a connecting portion between the flexible tube 1 and the bending portion 2 of the endoscope according to the second embodiment of the present invention, and FIG. 8 is a partially enlarged view thereof.
In this embodiment, the spot welded portion Po between the outer spiral tube 12 and the base 10 is formed so as to be locally recessed with respect to the surfaces of the base 10 and the outer spiral tube 12, and a soldering portion is formed in the recess. H solder protrudes and engages. The solder is in a molten state and fits into the recess and is cured as it is. Other configurations are the same as those of the first embodiment, and the same effects as those of the first embodiment can be obtained.

  Also in the second embodiment, the solder of the soldering portion H may protrude and engage with the recess at each portion of the spot welded portion Po provided at a plurality of locations.

DESCRIPTION OF SYMBOLS 1 Flexible tube 10 Base 11 Inner spiral tube 12 Outer spiral tube 13 Reticulated tube H Soldering part Po Spot welding part Po 'Convex part

Claims (5)

A mesh tube formed by braiding metal thin wires is coated on the outer surface of a metal spiral tube, and the end of the spiral tube is fixed to a metal base formed in a substantially cylindrical shape by spot welding. In a flexible tube of an endoscope having a configuration in which an end portion of the mesh tube is fixed to a surface of the base and the spiral tube by soldering in a region covering a spot welded portion and the periphery thereof,
The spot welded portion is formed so as to be locally convex with respect to the base and the surface of the spiral tube, and the convex portion engages with the mesh of the mesh tube. Endoscope flexible tube.   The flexible tube for an endoscope according to claim 1, wherein the spot welded portion is provided at a plurality of locations, and a convex portion of the spot weld is engaged with a mesh of the mesh tube at each portion.   Convex portions are formed on the surface of the die that do not contribute to fixation with the helical tube by the same process as the spot welding, and the convex portions engage with the meshes of the mesh tube. The flexible tube of the endoscope according to claim 1 or 2. A mesh tube formed by braiding metal thin wires is coated on the outer surface of a metal spiral tube, and the end of the spiral tube is fixed to a metal base formed in a substantially cylindrical shape by spot welding. In a flexible tube of an endoscope having a configuration in which an end portion of the mesh tube is fixed to a surface of the base and the spiral tube by soldering in a region covering a spot welded portion and the periphery thereof,
The spot welded portion is formed in a state of being locally recessed with respect to the base and the surface of the spiral tube, and the solder of the soldering portion protrudes and engages with the recessed portion. Endoscope flexible tube.   The flexible tube for an endoscope according to claim 4, wherein the spot welded portion is provided at a plurality of locations, and the solder of the soldered portion protrudes and engages with the spot weld recess at each portion.

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