JPH11267093A - Insertion portion for endoscope - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an insertion portion for an endoscope in which flexibility of a flexible tube is easily and smoothly changed in the middle without changing thickness or hardness of outer skin of the flexible tube. SOLUTION: In an insertion portion for an endoscope in which plural wire guides 24 comprising tight winding coil pipes for inserting and guiding operation wires 23 are inserted and disposed in a flexible tube to enclose the inspection portion, a flexibility restricting pipe 25 of super-elastic alloy having a cross sectional form corresponding to a space form around the wire guide 24 is put around at least one wire guide 24 of the plural wire guides 24 in a part positioned in the flexible tube in a range from a base end position of the flexible tube to a middle position.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an endoscope insertion portion to be inserted into a body cavity or the like.

[0002]

2. Description of the Related Art The insertion portion of a so-called flexible endoscope is constructed by inserting and arranging a built-in member such as an optical fiber bundle in an outer flexible tube. It is necessary to be flexible so as to bend relatively freely along the way, and to make the hand-side portion stiff so that a delicate push-pull operation or the like performed by the operator is transmitted to the tip side.

[0003] Conventionally, the flexibility of the exterior flexible tube itself has been changed on the way by changing the thickness, hardness, and the like of the outermost layer of the synthetic resin outer sheath of the exterior flexible tube depending on the position.

[0004]

The outermost layer of the synthetic resin outer sheath of the outer flexible tube is generally formed by extrusion molding. However, in a manufacturing method in which the thickness and hardness are changed one by one, the outer flexible tube is manufactured. Requires significant time and cost. In addition, when the molding conditions are changed in the middle in such a way, there are not a few cases where the flexibility of each product is varied due to the fluctuation of the molding conditions.

Accordingly, an object of the present invention is to provide an endoscope insertion portion in which flexibility is easily and smoothly changed on the way without changing the thickness and hardness of the outer skin of a flexible tube. .

[0006]

In order to achieve the above object, an insertion portion of an endoscope according to the present invention is provided with a tight winding for inserting and guiding an operation wire into a flexible tube which covers the insertion portion. In the insertion portion of the endoscope in which the plurality of wire guides made of coil pipes are inserted and arranged, the flexible tube is a part of at least one of the plurality of wire guides located in the flexible tube. In the range from the base end position to the intermediate position, a flexible suppressing pipe made of a superelastic alloy having a sectional shape corresponding to the space around the wire guide is fitted.

In addition, the flexibility suppressing pipes may be fitted to at least two of the plurality of wire guides with their tip positions shifted from each other. Alternatively, it may be fixed by being sandwiched between a pair of stopper members fixed to the wire guide.

The cross section of the flexibility suppressing pipe may be elliptical, and may have a surface along the inner peripheral surface of the flexible pipe.

[0009]

Embodiments of the present invention will be described with reference to the drawings. FIG. 2 shows an endoscope, in which an insertion portion to be inserted into a body cavity or the like has a bending portion 3 which is bent by a remote operation from the operation portion 1 at a distal end of a flexible portion covered by a flexible tube 2. A distal end main body 4 containing an objective optical system and the like is connected to the distal end of the curved portion 3.

On the surface of the distal end body 4, an observation window 5 for introducing an observation image into the objective optical system, an illumination window 6 for emitting illumination light toward an observation field, a treatment instrument insertion channel outlet 7a, and illustration are omitted. An air supply / water supply nozzle and the like are arranged.

A bending operation knob 8a for bending the bending portion 3 is provided on the operating portion 1 connected to the base end of the flexible tube 2.
8b is disposed, and one of the operation wires in the vertical direction is pulled by the bending operation knob 8a for the vertical direction, and the other operation wire in the left and right direction is pulled by the bending operation knob 8b for the right and left direction. The bending portion 3 can be bent in any direction.

The operation unit 1 also includes an air / water supply operation button 11, a suction operation button 12, and a treatment tool insertion port 7b.
Etc. are arranged. Reference numeral 14 denotes a light guide cable connected to a light source device (not shown).

FIG. 1 shows the flexible tube 2 of the insertion portion. The flexible tube 2 has an outer diameter of about 5 to 15 mm and a length of 50 to
Although it is about 150 cm, it is thicker and shorter than the actual figure for easy understanding.

The flexible tube 2 is constituted by covering a helical tube made of, for example, a metal strip with a mesh tube and covering the outer surface thereof with a sheath of polyurethane resin or the like. I have. Also, illustration of optical fiber bundles, tubes, and the like inserted and arranged inside is omitted.

The outer sheath portion covering the flexible tube 2 may have any structure, but the thickness and hardness of the outer sheath are changed in the middle to change the flexibility of the flexible tube 2 itself. No need.

At the base end of the flexible tube 2, a base connection base 21 for connecting to the operation unit 1 is attached.
A distal end connecting tube 22 for connecting the curved portion 3 is attached to a distal end portion of the connecting portion.

The distal end connecting tube 22 is formed of, for example, a stainless steel tube, and has a distal end of a wire guide 24 for loosely inserting and guiding the four operation wires 23 as shown in FIG. The parts are fixed to the inner peripheral surface at intervals of 90 ° by spot welding or silver brazing.

FIG. 1 shows two of the four sets of operation wires 23 and wire guides 24. The wire guide 24 is formed of a coil pipe in which a stainless steel wire is closely wound with a constant diameter, and each operating wire 23
Is connected to a distal end portion of the bending portion 3.

The proximal end of the wire guide 24 is
Is fixed to a bending operation mechanism frame (not shown) inside, and portions other than both end portions are inserted through the flexible tube 2 in a free state.

With respect to the wire guide 24 arranged as described above, a flexible suppressing pipe 25 made of a superelastic metal pipe material is covered in a range from the base end position of the flexible tube 2 to the intermediate position. It is fitted.

The superelastic metal is, for example, of Ti-Ni (titanium-nickel) type and has a very large elastic limit as a metal.
Does not undergo plastic deformation even if it is bent with a radius of curvature that allows it to be bent, and has a resilience to return to its original straight state.

The flexibility suppressing pipes 25 are fitted on two of the four wire guides 24, and each of the flexibility suppressing pipes 25 is spot-welded or welded to the outer peripheral surface of the wire guide 24. It is sandwiched between a pair of front and rear annular stoppers 26 fixed by silver brazing or the like, and is fixed to the wire guide 24 so as not to move in the axial direction.

FIG. 4 shows a cross section taken along line IV-IV in FIG. 1. In the flexible tube 2, the treatment instrument insertion channel 7, image guide fiber bundle 15, light guide fiber bundle 16, air supply tube 17, water supply The tube 18, the water supply tube 19 for injection, and the like are inserted and arranged side by side.

The flexibility suppressing pipe 25 has an elliptical cross section corresponding to the space around the flexibility suppressing pipe 25 in the flexible tube 2. As described above, the cross-sectional shape of the flexibility suppressing pipe 25 can be formed in an arbitrary shape corresponding to the surrounding space shape. For example, as shown in FIG. May be formed in an irregular cross-sectional shape having a surface along the line.

In this manner, in the portion near the base end of the flexible tube 2 in which the flexibility suppressing pipe 25 is fitted to each wire guide 24, the flexibility is suppressed when the flexible tube 2 is bent. The pipe 25 acts as a resistance to suppress flexibility, and the push-pull operation of the flexible tube 2 and the like are easily transmitted to the distal end side.

The portion of the flexible tube 2 closer to the distal end where the flexible guide pipe 25 is not fitted on the wire guide 24 is connected to the flexible pipe 2 in response to the bending operation of the flexible tube 2. Has no effect, and therefore has high flexibility (that is, high flexibility) and smoothly deforms along the organ shape in the body cavity.

However, if such a structure is simply employed, the flexibility of the intermediate portion of the flexible tube 2 may suddenly change, making it difficult to use, or the portion may be rapidly bent at the portion to be easily broken.

Therefore, in this embodiment, two flexible suppressing pipes 25 are fitted to the respective wire guides 24 so that their tip positions are shifted from each other, whereby the middle of the flexible tube 2 is formed. The flexibility in the part is changing smoothly.

However, the present invention is not limited to this, and the flexibility suppressing pipe 25 may be fitted to only one wire guide 24, and three or more wire guides 2
4 may be fitted with a pipe 25 for suppressing flexibility.

[0030]

According to the present invention, of the portion of the wire guide located in the flexible tube, the flexible portion made of superelastic metal pipe material is provided in the range from the base end position to the intermediate position of the flexible tube. The flexibility of the portion covered with the flexible tube can be easily changed without variation in each product in the middle without changing the thickness and hardness of the outer skin of the flexible tube by fitting the pipe for suppressing the property. The cross section of the flexibility suppressing pipe is formed in a shape corresponding to the space shape around the wire guide, so that the space in the flexible tube can be effectively used without making the flexible tube thick. Can be.

[Brief description of the drawings]

FIG. 1 is a sectional view of a plane including an axis of a flexible tube portion of an insertion section of an endoscope according to an embodiment of the present invention.

FIG. 2 is a schematic diagram showing the appearance of an endoscope.

FIG. 3 is a sectional view taken along the line III-III in FIG. 1 of the embodiment of the present invention.

FIG. 4 is a sectional view taken along line IV-IV in FIG. 1 of the embodiment of the present invention.

FIG. 5 is a sectional view of another example of the section taken along the line IV-IV in FIG. 1 according to the embodiment of the present invention;

[Explanation of symbols]

 2 Flexible tube 23 Operation wire 24 Wire guide 25 Pipe for suppressing flexibility

Claims (5)

[Claims] An insertion part of an endoscope in which a plurality of wire guides each composed of a tightly wound coil pipe for inserting and guiding an operation wire through a flexible tube which covers an insertion part is provided. Of the portions of at least one of the wire guides located in the flexible tube, a portion corresponding to the space shape around the wire guide in a range from a base end position to an intermediate position of the flexible tube. An insertion part for an endoscope, wherein a pipe for suppressing flexibility made of a superelastic alloy having a cross-sectional shape is fitted. 2. The endoscope insertion section according to claim 1, wherein the flexibility suppressing pipes are fitted to at least two of the plurality of wire guides with their tip positions shifted from each other. . 3. The endoscope insertion part according to claim 1, wherein the flexibility suppressing pipe is sandwiched and fixed between a pair of stopper members fixed to the wire guide. 4. The insertion part for an endoscope according to claim 1, wherein said flexible suppressing pipe has an elliptical cross section. 5. The endoscope insertion section according to claim 1, wherein the cross-sectional shape of the flexibility suppressing pipe has a surface along an inner peripheral surface of the flexible tube.