JPH0612723Y2 - Endoscope insertion part - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial application] The present invention relates to an insertion portion of an endoscope in which a bending portion is connected to a distal end of a flexible tube.

[Prior Art] Since the bending portion is bent with a small radius of curvature by remote control, breakage or buckling of internal components such as optical fiber bundles and tubes inserted through the bending portion is likely to occur. Especially when there is no space for the built-in objects to move freely, especially when the curved part is bent,
Easy to break or buckle. Therefore, the inner diameter of the curved portion must be thick enough to allow a little room for the built-in object.

On the other hand, when the endoscope is inserted, for example, from the mouth of the patient, the patient feels pain if the portion inserted into the throat is thick. Therefore, the flexible tube of the insertion portion should be as thin as possible. Since the curved portion touches the throat only for a moment when it first passes through the throat, it is not necessary to forcibly thin the curved portion.

Therefore, in the insertion portion of the endoscope in consideration of the durability of the built-in object, the inner diameter of the bending portion is generally formed larger than the inner diameter of the flexible tube, and the tip of the guide coil that inserts the bending operation wire is inserted. The portion was fixed to the inner peripheral surface of the distal end portion of the flexible tube.

The tip of the guide coil must be fixed so as not to be displaced in the circumferential direction according to the traveling direction of each operation wire. This is because if the fixed position of the tip of the guide coil is displaced, the operating wire is rubbed in the middle, a wire cutting accident occurs, and the bending shape of the bending portion is distorted.
Therefore, when the bending portion bends in, for example, the four directions of up, down, left, and right, the tip portions of the four guide coils 51 are fixed to the tip portion 52 of the flexible tube at intervals of approximately 90 degrees as shown in FIG. It had been.

[Problems to be Solved by the Invention] However, the inner diameter of the flexible tube is smaller than the inner diameter of the bending portion, and the tip portion of the flexible tube is connected to the bending portion.
Generally, it has the smallest inner diameter in the insertion part. Therefore, if the tip part of the guide coil is fixed to this part,
As shown in FIG. 4, a thick built-in object such as the forceps channel 53 does not fit between the adjacent guide coils 51, and a large dead space 54 is generated, which significantly narrows the internal space and improves the durability of the built-in object. Was causing the damage. Further, in order to avoid this, the diameter of the forceps channel 53 or other built-in object must be reduced, and the performance of the endoscope is reduced.

Therefore, the tip end portion of the guide coil is fixed to the inner wall of the curved portion with a large inner diameter so that the guide coil can move in the circumferential direction at the front end portion of the flexible tube, and the forceps channel or the like is housed between the adjacent guide coils. It is possible to do so. However, if it is simply done, the guide coil is pressed and deformed by the step on the inner surface generated between the curved portion with a large inner diameter and the thin flexible tube, and the operation wire inserted inside the guide coil is damaged and bent. This causes inconvenience such as inability to operate.

The present invention eliminates such conventional drawbacks and allows insertion of a built-in object so that the space inside the insertion portion is not wasted, and the durability of the bending operation wire etc. is not impaired. It is intended to provide an insert.

[Means for Solving the Problems] In order to achieve the above-mentioned object, the insertion portion of the endoscope of the present invention has a curved portion having an inner diameter larger than the inner diameter of the flexible tube at the distal end of the flexible tube. The distal end of the operating wire is connected to the distal end of the bending portion, and the operating wire is inserted through the guide coil whose both ends are fixed, and the operating wire is pulled from the base side to remote the bending portion. In the insertion portion of the endoscope that is bent flexibly, the tip end portion of the guide coil is fixed to the inner wall of the bending portion, the guide coil is loosely inserted into the flexible tube, and the bending portion is flexible. It is characterized in that the inner diameter of the connecting portion with the flexible tube is formed into a tapered surface whose diameter changes gently.

[Operation] The tip portion of the guide coil is fixed to the inner wall of the curved portion, and the guide coil can move in the circumferential direction at the tip portion of the flexible tube. Therefore, even if internal components such as forceps channels interfere with the guide coil in layout, the guide coil moves in the circumferential direction at the distal end portion of the flexible tube,
The internal component is housed between the two guide coils.

And, since the inner diameter of the connecting portion between the bending portion and the flexible tube is formed into a gently tapered surface, the guide coil bends smoothly and smoothly at the connecting portion between the bending portion having a large inner diameter and the thin flexible tube, No catching or buckling.

[Example] An example will be described with reference to the drawings.

FIG. 2 is a schematic view of the entire endoscope. Reference numeral 10 is an insertion portion, and a bending portion 14 is connected to the tip of the flexible tube 11.
The bending portion 14 is moved up and down via an operation wire (not shown in FIG. 2) by rotating the up-down bending operation knob 13a and the left-right bending operation knob 13b provided on the operation portion 12. And bends freely in the left-right direction.
Then, the distal end portion main body 15 provided with the objective optical system and the forceps projecting opening is connected to the distal end of the bending portion.

FIG. 1 shows the vicinity of the connecting portion between the flexible tube 11 and the bending portion 14. Internal components such as an optical fiber bundle and a forceps channel made of a tetrafluoroethylene tube are inserted through the inside, but the illustration thereof is omitted.

16 and 17 are spiral tubes having different winding directions. 18
Is a reticulated tube made of thin metal wire coated on the outside. 19
Is a die fixed to the tip portions of the spiral tubes 16 and 17 and the mesh tube 18 by soldering, and the tip portion of a flexible outer skin 20 that covers the mesh tube 18 from the outside is a central portion of the die 19. It is squeezed and adhered so as to come into close contact with the peripheral recessed groove 19a formed in.

Reference numeral 21 is one of a large number of node rings forming the bending portion 14. The node ring 21 is an annular body, and each node ring 21 is provided with a pair of tongue pieces 21 a on both front and rear sides thereof.
In the a portion, the front and rear adjacent joint rings are rotatably connected by rivets 22. Reference numeral 23 is a base ring of a curved portion that is rotatably connected to the node ring at the rear end. The outer sides of the node ring 21 and the base ring 23 are covered with a mesh tube 24 made of thin metal wire.

Reference numeral 30 is a connecting pipe that connects the flexible pipe 11 and the bending portion 14. The connection pipe 30 is first fixedly connected to the base ring 23 of the bending portion 14 and the mesh pipe 24 by soldering, and then connected to the base 19 of the flexible pipe 11 by a flat head screw 25. The outer side of the flexible tube 11 is covered with a rubber tube elastic outer skin 26 that covers the outer surface of the curved portion 14, and the rear end of the elastic outer skin 26 is superposed on the outer side of the front end of the outer skin 20 of the flexible tube 11. It is fixed by thread tightening adhesive.

As shown in FIG. 1, node ring 21 and base ring 23
The inner diameter of the spiral tube 16 and the cap 19 inside the flexible tube 11 is
Is formed to be thicker than the inner diameter of.

The inner diameter of the connecting pipe 30 is formed on the tapered surface 30a that gradually changes from the same inner diameter as that of the thick base ring 23 to the same inner diameter as that of the base 19 narrower than that.

Reference numeral 31 is a bending operation wire, and a total of four bending wires are provided for each of the up, down, left, and right directions. The tip of each operation wire 31 is fixed to the tip of the bending portion 14, and the bending operation knobs 13a and 13b are provided.
Is pulled by the rotation of. Reference numeral 32 is a guide coil made of, for example, a stainless steel wire, into which the operation wire 31 is inserted so as to move back and forth. The tip of the guide coil 32 has a curved portion 14
It is fixed to the inner wall surface of the node ring 21 arranged at the rear part by means of silver brazing or the like. And the guide coil 32
Runs along the inner peripheral surface of the base ring 23, bends inward gently along the tapered surface 30a of the connecting pipe 30, and is fixed in the flexible tube 11 along the inner peripheral surface thereof. It is inserted without play. And the guide coil 32
The base end portion of is fixed in the operation portion 12.

Therefore, the guide coil 32 includes the curved portion 1 having a large inner diameter.
4 and the thin flexible tube 11, the taper surface 30a of the inner surface of the connection tube 30 gently bends inwardly without any catching or buckling. Further, the guide coil 32 can freely move in the circumferential direction at the tip portion of the flexible tube 11 having the smallest inner diameter. Therefore, even if the built-in components such as the forceps channel and the guide coil 32 interfere with each other, the guide coil 32 moves in the circumferential direction as shown in FIG. Since it is housed between the coils 32, no waste occurs in the internal space of the insertion section.

[Advantage of Invention] According to the insertion portion of the endoscope of the present invention, the guide coil of the bending operation wire moves in the circumferential direction at the distal end portion of the flexible tube, and the built-in objects such as forceps channels are adjacent to each other. Since it is housed between the guide coils, the built-in object can be inserted without waste in the internal space of the insertion portion.

Further, between the curved portion having a large inner diameter and the thin flexible tube, the guide coil bends smoothly along the taper surface, and no catching or buckling occurs, so that the operation wire is not damaged, which is excellent. Has durability.

[Brief description of drawings]

FIG. 1 is a partial side sectional view of an embodiment, FIG. 2 is an overall schematic sectional view of an endoscope, FIG. 3 is a schematic front sectional view of an embodiment, and FIG. 4 is a schematic front sectional view of a conventional example. Is. 11 ... Flexible tube, 14 ... Curved part, 21 ... Node ring, 30
...... Connecting tube, 30a ・ ・ ・ Tapered surface, 31 ・ ・ ・ Operating wire, 32 ・ ・ ・ Guide coil.

Claims (1)

[Scope of utility model registration request] 1. A flexible tube is connected to a curved portion having an inner diameter larger than that of the flexible tube, the distal end of the operation wire is attached to the distal end of the curved portion, and both ends are fixed. In the insertion portion of the endoscope in which the operation wire is inserted into the guide coil and the operation wire is pulled from the base side to remotely bend the bending portion, the distal end portion of the guide coil is bent. The guide coil is loosely inserted into the flexible tube by directly fixing it to the inner wall of the section, and the inner diameter of the connecting portion between the bending section and the flexible tube is formed into a taper surface without a step whose diameter changes gently. The insertion part of the endoscope characterized by the above.