JP5145108B2 - Endoscope insertion part - Google Patents

Description

  The present invention relates to an insertion portion of an endoscope.

  In general, an insertion portion of an endoscope is configured such that a bending portion that is bent by remote control is arranged in series with a distal end portion of a flexible tube, and the bending portion includes a plurality of articulated rings that are rotatably connected to each other. Is used for the framework and is covered with a flexible outer shell, and the flexible tube is a spiral tube formed by winding a metal strip with a substantially constant diameter in a spiral manner with a gap in between. And is covered with a flexible outer skin.

  In recent years, the connecting portion between the bending portion and the flexible tube in the insertion portion of the endoscope is attached to each end portion of the bending portion 91 and the flexible tube 92 as shown in FIG. 10, for example. In many cases, the ring-shaped coupling caps 93 and 94 are fitted and fixed with screws 95 (for example, Patent Document 1).

Further, in the old technology, there is a technique in which a fitting portion between connecting bases attached to each end portion of a bending portion and a flexible tube is fixed by soldering or brazing (for example, Patent Document 2). There is also an example in which a single connection cap is used (for example, Patent Document 3).
JP2007-252560 JP-A-10-137175 JP 5-42096A

  As described above, in the insertion portion of the conventional endoscope, the connection bases 93 and 94 for connecting the bending portion 91 and the flexible tube 92 are provided, and the rear of the joint ring of the bending portion 91 is provided. The end portion 91x and the distal end portion 92a of the helical tube of the flexible tube 92 are overlapped with the connection caps 93 and 94 in the radial direction, respectively.

  For this reason, the thickness of the entire member increases at the connecting portion between the bending portion 91 and the flexible tube 92, and it is inevitable that the outer diameter increases only in that portion (otherwise the inner diameter decreases). Although this is not a problem with large-diameter endoscopes, it has been a cause of deterioration in insertability (or deterioration in observation ability due to insufficient built-in light guide amount, etc.).

  The present invention can improve the insertion performance and the observation ability by increasing the amount of the built-in light guide, etc. without increasing the thickness of the connecting portion between the bending portion and the flexible tube. The object is to provide a mirror insert.

In order to achieve the above object, the insertion portion of the endoscope of the present invention includes a curved portion in which a plurality of joint rings that are rotatably connected to each other are used in a framework and are covered with an elastic outer skin, A spiral tube formed by winding a metal strip with a substantially constant diameter in a spiral manner is used for the framework, and a flexible tube covered with a flexible outer skin is connected in series. In the insertion portion of the endoscope in which the inner and outer double spiral tubes having different winding directions are used as the spiral tube, the inner and outer diameters are approximately the same as the inner and outer diameters of the combined inner and outer double spiral tubes. The outer diameter of the latter half portion of the formed connection cap is formed to be substantially the same diameter as the boundary surface of the inner and outer double spiral tubes, and the small outer diameter portion is the outer side of the inner and outer double spiral tubes. fitted into the front end portion of the spiral tube, the inner helical tube is retracted relative to the distal end surface of the outer helical tube An end face with a tip portion of the connecting cap and said inner and outer double spiral tube in a state of contact with the rear end face of the connecting cap is fixed, the rear end of the front end surface and the curved portion of the connecting cap joint The rear end surface of the ring is abutted, and the coupling base and the articulated ring at the rear end are connected and fixed by welding at the abutting portion.

  The welding at the abutting portion may be performed by laser welding, and the connection base and the tip portion of the inner and outer double spiral tubes may be fixed by laser welding. Further, it is preferable that welding between the coupling base and the rear end joint ring is performed on the entire circumference of the abutting portion so that the abutting portion is in a watertight state.

  In addition, the inner and outer double spiral tubes may be fixed to each other in the vicinity of the front end connected to the connection base, and the outer periphery of the welded portion between the connection base and the rear end joint ring is covered with the outer skin of the curved portion. May be.

  According to the present invention, the inner and outer diameters of the combined spiral tube having the inner and outer diameters are formed to be approximately the same as the inner and outer diameters, and are fixed to the distal end portion of the spiral tube and the rear end of the curved portion. The rear end surface of the joint ring is abutted, and the joint base and the rear end joint ring are joined and fixed by welding at the abutting portion, so that the member of the joint portion of the bending portion and the flexible tube Since the thickness does not increase, it is possible to improve the insertability by not increasing the outer diameter of the connecting portion, and improving the observation ability by reducing the inner diameter of the connecting portion (by increasing the amount of built-in light guide, etc.). .

  A plurality of articulated rings that are pivotally connected to each other are used as a framework, and a curved portion covered with an elastic outer skin and a metal strip are wound in a spiral with a substantially constant diameter. The spiral tube formed in this way is used in the framework and is connected in series with the flexible tube sheathed with a flexible outer shell, and an inner and outer double spiral tube with different winding directions is used as the spiral tube. In the insertion part of the endoscope, the outer diameter of the second half of the connecting cap formed with the inner and outer diameters of the inner and outer double spiral tubes combined with the inner and outer double spiral tubes is the boundary of the inner and outer double spiral tubes. The small outer diameter portion is fitted into the distal end portion of the outer spiral tube of the inner and outer double spiral tubes, and the distal end surface of the inner spiral tube is formed on the rear end surface of the connection cap. In the state of contact, the connection base and the distal end portion of the inner and outer double spiral pipes are fixed, and the front end of the connection base And the rear end surface of the rear end of the joint ring of the bending portion is abutted, and joint ring of the connecting mouthpiece and rear at the abutting portion is fixedly connected by welding with.

Embodiments of the present invention will be described below with reference to the drawings.
FIG. 2 shows the overall configuration of the endoscope. The insertion portion inserted into the body has a configuration in which a bending portion 20 that is bent by remote operation is connected in series to the distal end portion of the flexible flexible tube 10. doing. A is a connecting portion between the flexible tube 10 and the bending portion 20. A light guide fiber bundle for illumination and other so-called built-in objects are inserted into the insertion portions 10 and 20, but the illustration thereof is omitted in each drawing.

  A bending operation lever 31 is disposed on the operation unit 30 connected to the base end of the flexible tube 10, and the bending unit 20 can be bent by an arbitrary angle by rotating the bending operation lever 31. it can.

  FIG. 1 shows the vicinity of the connecting portion A between the flexible tube 10 and the bending portion 20, and the framework of the flexible tube 10 is made of a metal strip such as a stainless steel strip with a substantially constant diameter. The outer periphery of the spiral tube 11 formed by spirally forming a gap is formed by covering a mesh tube 12 formed by braiding a fine wire material such as a stainless steel fine wire material.

  As the spiral tube 11, two spiral tubes 11 i and 11 o having different winding directions are overlapped and used inside and outside, and the flexible tube 10 is made of, for example, a flexible material made of polyurethane resin or the like. An outer skin 13 is formed on the outer surface of the mesh tube 12 by, for example, extrusion molding. However, a tubular material or the like may be used as the outer skin 13.

  A short cylindrical connection base 40 made of, for example, stainless steel or the like is connected and fixed to the distal end portions of the inner and outer double spiral tubes 11i and 11o, for example, by laser welding. However, since it is difficult to firmly fix the inner spiral tube 11 i to the connection cap 40, the inner and outer double spiral tubes 11 i and 11 o are fixed to each other in the vicinity of the tip connected to the connection cap 40.

  FIG. 3 shows a state before the two spiral tubes 11i and 11o and the connection cap 40 are assembled. However, the inner and outer diameters (d) and (α) of the inner spiral tube 11i shown in FIG. 3 are dimensions after the two spiral tubes 11i and 11o are overlapped as shown in FIG. It is.

  The inner and outer diameters d and D of the connection cap 40 are formed to have substantially the same dimensions as the inner and outer diameters of the combined inner and outer double spiral tubes 11i and 11o. However, the outer diameter α of the latter half portion (upper side portion in the figure) of the coupling base 40 is the diameter of the boundary surface between the inner and outer double spiral tubes 11i and 11o (that is, the outer diameter of the inner spiral tube 11i and the outer spiral). The inner diameter of the tube 11o is substantially the same.

  And as FIG. 1 shows, the small outer diameter part 41 is inserted in the front-end | tip part of the outer side spiral tube 11o, and the front end surface of the inner side spiral tube 11i contact | abutted to the rear-end surface of the connection nozzle | cap | die 40, The connection base 40 and the distal end portions of the inner and outer double spiral tubes 11i and 11o are fixed.

  FIG. 4 shows the assembled state, and the inner and outer diameters of the distal end surface 40a of the coupling base 40 which becomes the distal end surface when the coupling base 40 is attached to the distal ends of the inner and outer double spiral tubes 11i and 11o. d and D substantially coincide with the inner and outer diameters of the inner and outer double spiral tubes 11i and 11o.

  Returning to FIG. 1, the reticulated tube 12 and the outer skin 13 of the flexible tube 10 are compared with the assembly in which the connection cap 40 is attached to the tip of the inner and outer double spiral tubes 11i and 11o as described above. However, it is not covered at the position of the front end surface 40a of the connection base 40.

  In manufacturing, the reticulated tube 12 and the outer skin 13 once coated on the entire flexible tube 10 are cut off in the vicinity of the front end surface 40 a of the connection base 40, and the front end portion of the outer skin 13 is fixed with a binding thread 14. In addition, by forming the outer skin 13 thinly only at the binding portion, the maximum outer diameter of the connecting portion A can be reduced, and the same processing may be performed on the outer skin 24 of the bending portion 20 described later.

  The framework of the bending portion 20 is formed by braiding fine wires such as stainless steel fine wires on the outer peripheral portions of a plurality of articulation rings 21 made of, for example, stainless steel pipes, which are connected in series with each other by rivets 22 or the like. It is formed so as to cover the mesh tube 23 formed. A resilient outer skin 24 such as a rubber tube is covered on the outer surface of the mesh tube 23 as an exterior of the bending portion 20.

  A plurality of operation wires 25 are selectively pulled from the operation unit 30 side by the operation of the bending operation lever 31, and the distal ends thereof are connected to the distal end portion of the bending unit 20. A guide coil 26 guides the operation wire 25 in the flexible tube 10, and its tip is fixed to the inner peripheral portion of the joint ring 21 x at the rear end of the bending portion 20.

  The articulation ring 21x at the rear end of the bending portion 20 is arranged in a state where the rear end surface thereof is abutted against the front end surface 40a of the connection base 40, and the rear end articulation ring 21x and the connection base 40 at the abutting part T. Are directly connected by laser welding from the outer surface side. Therefore, the thickness of the member of the connecting portion A does not increase at all as compared with the case where the flexible tube 10 and the bending portion 20 are directly connected.

  As a result, since the outer diameter of the connecting portion A does not increase, the insertion property can be improved, and the inner diameter of the connecting portion A does not decrease, so that the observation ability is improved by increasing the amount of the built-in light guide. Etc.

  Further, laser welding of the abutting portion T between the joint ring 21x at the rear end of the bending portion 20 and the distal end surface 40a of the coupling base 40 can be performed without a break from the outer surface side over the entire circumference. Watertightness can be ensured.

  The laser welding operation is performed while cooling before the outer skin 24 is covered with the curved portion 20, and after the laser welding is finished, the outer skin 24 is attached and the vicinity of the rear end thereof is fixed with the binding thread 27. The end portion of the outer skin 24 extends and covers the outer surface of the abutting portion, and the protective adhesive 28 is applied to the outer surface of the connecting portion A, so that the water tightness of the abutting portion T is secured, thereby hardening. There is no possibility that the previous adhesive 28 enters the inside of the abutting portion T.

  The laser welding for connecting the bending portion 20 and the connection base 40 can be performed by directly irradiating the abutting portion T between the joint ring 21x at the rear end of the bending portion 20 and the connection base 40 with laser light. An annular welding ring 1 made of, for example, stainless steel as shown in FIG. 5 is arranged along the outer surface of the abutting portion T as shown in FIG. 6, and the welding ring 1 is irradiated with laser light. You may do it. By doing in this way, since a laser beam does not permeate | transmit the abutting part T part, it does not have a bad influence on the inside.

  In this case, as shown in FIGS. 7, 8, and 9, a welding ring 1 having a non-circular cross-sectional shape such as a rectangle, a triangle, or a semicircle is used. By forming the peripheral side in a planar shape, the welding ring 1 can be stably positioned with respect to the abutting portion T, and laser welding can be performed accurately and reliably. In this case, the outer diameters of the rear end joint ring 21x and the coupling base 40 are aligned at the abutting portion T.

  Note that the present invention is not limited to the above-described embodiment. For example, the rear end joint ring 21x disposed so that the end faces are abutted against each other and the connection base 40 are connected and fixed by welding means other than laser welding. May be.

It is side surface sectional drawing of the connection part vicinity of the flexible tube and bending part of the insertion part of the endoscope of 1st Example of this invention. 1 is an overall configuration diagram of an endoscope to which the present invention is applied. It is a disassembled perspective view of the spiral tube and connecting base which comprise the flexible tube of 1st Example of this invention. It is a perspective view in the state where the connection mouthpiece was attached to the tip of the inside and outside double spiral tube in the 1st example of the present invention. It is a single-piece | unit perspective view of the welding ring used for the 2nd Example of this invention. In 2nd Example of this invention, it is side surface sectional drawing of the state just before the connection part of a flexible tube and a bending part is laser-welded. In the modification of the 2nd Example of this invention, it is a side sectional view of the state just before the connection part of a flexible tube and a bending part is laser-welded. In the 2nd modification of the 2nd Example of this invention, it is side surface sectional drawing of the state just before the connection part of a flexible tube and a bending part is laser-welded. In the 3rd modification of the 2nd Example of this invention, it is side surface sectional drawing of the state just before the connection part of a flexible tube and a bending part is laser-welded. It is side surface sectional drawing of the connection part vicinity of the flexible tube and bending part of the insertion part of the conventional endoscope.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Welding ring 10 Flexible tube 11 Spiral tube 11i Inner spiral tube 11o Outer spiral tube 13 Outer skin 20 Curved part 21 Articular ring 21x Rear end joint ring 24 Outer skin 40 Connection base 40a Tip surface 41 Small outer diameter part A Connection part T Hitting part

Claims (6)

A plurality of articulated rings that are pivotally connected to each other are used as a framework, and a curved portion covered with an elastic outer skin and a metal strip are wound in a spiral with a substantially constant diameter. The spiral tube formed in this way is used for the framework and is connected in series with the flexible tube sheathed with a flexible skin, and the spiral tube having the inner and outer double directions with different winding directions is used as the spiral tube. In the endoscope insertion section,
The outer diameter of the second half of the coupling cap formed with the inner and outer double spiral tubes combined with the inner and outer double diameters is approximately the same as the boundary surface of the inner and outer double spiral tubes. The distal end of the inner spiral tube is formed and the small outer diameter portion is fitted into the distal end portion of the outer spiral tube of the inner and outer double spiral tubes and is retracted with respect to the distal end surface of the outer spiral tube. The connection base and the distal end portion of the inner / outer double spiral tube are fixed in a state where the surface is in contact with the rear end surface of the connection base, and the joint between the front end surface of the connection base and the rear end of the bending portion An insertion portion of an endoscope, characterized in that a rear end surface of a ring is abutted and the connection base and the articulation ring at the rear end are connected and fixed by welding.   The endoscope insertion portion according to claim 1, wherein welding at the abutting portion is performed by laser welding.   The insertion portion of the endoscope according to claim 1 or 2, wherein the connection base and a tip portion of the inner / outer double spiral tube are fixed by laser welding.   4. The welding according to claim 1, wherein welding of the connection base and the articulation ring at the rear end is performed on the entire circumference of the abutting portion, and the abutting portion is in a watertight state. Endoscope insertion part.   The endoscope insertion portion according to any one of claims 1 to 4, wherein the inner and outer double spiral tubes are fixed to each other in the vicinity of a tip connected to the connection cap. The insertion portion of the endoscope according to any one of claims 1 to 5, wherein an outer peripheral portion of a welded portion between the connection base and the joint ring at the rear end is covered with an outer skin of the curved portion.

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