JP2529982B2 - Wire guide structure for endoscope - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a guide structure for an operation wire that is inserted through an insertion portion of an endoscope and is used for adjusting an objective focus.

[Conventional technology]

In an endoscope, an insertion section that is extended from an operation section and inserted into a body cavity or the like is composed of a flexible section, a bending section, and a tip forming section.

The operation wire guided from the tip forming section to the operation section is
The curved portion and the flexible portion on the way are guided by the guide means so as to be movable in the axial direction.

Regarding the structure of the conventional wire guide, Figs.
It will be explained based on FIG.

That is, 1 is a semi-flexible portion provided in the flexible portion of the endoscope, and the semi-flexible portion 1 is formed of a pipe such as a stainless pipe 2.

Reference numeral 3 denotes a flexible portion provided in the flexible portion of the endoscope. The flexible portion 3 is composed of a slidable tube including a Teflon tube 4 and a stainless mesh wire 5 covering the Teflon tube 4. It is composed of a reinforcing coating and an outer cover made of a heat-shrinkable tube 6 covering the stainless wire 5.

The quasi-flexible portion 1 and the flexible portion 3 are connected to each other at their ends to form a wire guide passage 7 inside.
As shown in detail in FIG. 11, this connecting portion has a retaining ring 8 fixed to the outer periphery of the end of the stainless steel pipe 2 by brazing or welding. The end portion of the Teflon tube 4 which constitutes the flexible portion 3 is covered with and is joined with an adhesive or the like.

An operation wire 9 is inserted through the wire guide passage 7 configured as described above, and the operation wire 9 is pulled out or extended based on the operation of the knob of the operation portion, and therefore, inside the wire guide passage 7. It is designed to be moved in the axial direction.

[Problems to be Solved by the Invention]

However, in the above conventional case, when the flexible portion 3 is bent by applying a bending force to the soft portion,
As shown in the figure, in the connecting portion between the semi-flexible portion 1 and the flexible portion 3, the flexible portion 3 is different from the bent state of the stainless pipe 2.
Because of the large curvature, the operation wire 9 may come into contact with the end 2a of the stainless pipe 2. In FIG. 12, the stainless wire 5 and the heat shrinkable tube 6 are omitted.

The contact between the operation wire 9 and the end portion 2a of the stainless steel pipe 2 as described above becomes a resistance against the movement of the operation wire 9 in the axial direction, which may cause a catch or hinder the smooth movement of the operation wire 9. However, there are drawbacks such as causing discontinuous movement.

Further, the above contact causes wear on the operation wire 9,
There is also a problem that the operation wire 9 is damaged early.

The present invention prevents the operation wire from coming into contact with the end of the stainless pipe even when the connecting portion between the semi-flexible portion and the flexible portion is bent, smoothes the movement of the operation wire, and prevents early wear. It is an object of the present invention to provide a wire guide structure for an endoscope which prevents the wire.

[Means for solving the problem]

The present invention relates to a wire guide structure for an endoscope in which a semi-flexible portion made of a pipe is connected to a flexible portion made of a soft tube, and an operation wire is inserted through the semi-flexible portion and the flexible portion. In the connection boundary part between the quasi-flexible part and the flexible part, the quasi-flexible part has a hardness intermediate between the hardness of the quasi-flexible part and the hardness of the flexible part or higher. A bending restriction member is provided, in which the flexible portion is sandwiched and fixed to the semi-flexible portion, and an end face on the flexible portion side projects toward the flexible portion from the connection boundary portion. And

[Action]

According to the present invention, the bending amount of the flexible portion with respect to the quasi-flexible portion is limited by the bending restriction tube at the connecting boundary portion between the quasi-flexible portion and the flexible portion, and therefore the operation is performed. The wire is prevented from contacting the end of the stainless pipe. Therefore, the movement of the operation wire becomes smooth, and premature wear of this wire is prevented.

〔Example〕

Hereinafter, the present invention will be described with reference to FIG. 1 and FIG.
A description will be given based on the embodiment of.

In the present embodiment, the same members as those of the related art shown in FIGS. 10 to 12 are designated by the same reference numerals and the description thereof will be omitted.

The present embodiment is different from the conventional one in that the bending restriction tube 10 is provided.

The bending control tube 10 is made of a material having a hardness between the hardness of the stainless steel pipe 2 and the hardness of the Teflon tube 4 or a hardness higher than that, for example, a metal tube such as stainless steel, one end of which is made of the stainless steel pipe 2. It is positioned on the outer side closer to the end 2a than the retaining ring 8 and is fitted over the outer side of the Teflon tube 4 and fixed by an adhesive or the like. In this case, the Teflon tube 4 is sandwiched and fixed between the bending regulation member 10 and the stainless steel pipe 2. The other end 10a of the bending regulation tube 10 is extended to the Teflon tube 4 side from the end 2a of the stainless pipe 2.

With such a configuration, when the flexible portion 3 is bent, as shown in FIG. 2, at the connecting portion between the quasi-flexible portion 1 and the flexible portion 3, the bending regulation tube provided here is provided. Since 10 projects more toward the Teflon tube 4 side than the end 2a of the stainless pipe 2, the Teflon tube 4 is prevented from starting to bend from the end 2a of the stainless pipe 2, and bends from the end 10a of the bending regulation tube 10. Get started

Therefore, the operation wire 9 is prevented from directly contacting the end portion 2a of the stainless pipe 2, and the bending restriction tube is prevented.
The end portion 10a of 10 comes into contact with the end portion 10a through the Teflon tube 4.

Since the contact between the operation wire 9 and the Teflon tube 4 does not resist the movement, the operation wire 9 is prevented from being caught, the operation wire 9 can be smoothly moved, and awkward discontinuous movement is prevented. be able to.

In addition, it is possible to prevent early wear of the operation wire 9 and prolong the life of the operation wire 9.

Note that, in FIG. 2, the illustration of the stainless mesh wire 5 and the heat shrinkable tube 6 is omitted.

 FIG. 3 shows a second embodiment of the present invention.

In the second embodiment, the end of the heat-shrinkable tube 6 is cut so as not to overlap the end of the stainless steel pipe 2, and the other structure is the same as that of the first embodiment.

By doing so, the members are not piled up on the end of the stainless pipe 2 in multiple layers, the outer diameter of the end of the stainless pipe 2 can be reduced, and the maximum diameter can be reduced. .

 FIG. 4 and FIG. 5 show a third embodiment of the present invention.

In this embodiment, the bending restriction tube 20 is attached to the outside of the heat shrinkable tube 6, and the bending restriction tube 20 is softer than the stainless steel pipe 2 but harder than the Teflon tube 4, that is, the stainless steel pipe 2. It is different from the first embodiment in that it is formed of a member having an intermediate hardness between the Teflon tube 4 and the Teflon tube 4, for example, a synthetic resin having elasticity.

With such a configuration, even when the Teflon tube 4 is extremely curved, the bending control tube provided at the boundary between the stainless pipe 2 and the Teflon tube 4
Teflon tube 4 at this boundary due to bending resistance of 20
Is prevented from being rapidly bent, and buckling deformation is prevented from occurring. Moreover, since the bending control tube 20 is made of an elastic synthetic resin having a hardness intermediate between those of the stainless pipe 2 and the Teflon tube 4, the Teflon tube 4
To prevent an extreme curve (curvature radius R2 or less) from occurring, and since the bend restricting tube 20 itself causes a slight curve (curvature radius R1), it allows the Teflon tube 4 to slightly curve. Therefore, the operation wire 9 is restricted by the regulation tube
The inner surface of the Teflon tube 4 facing the end of the Teflon tube 4 is prevented from being strongly rubbed, and the operation wire 9 and the Teflon tube 4 are prevented.
Wear can be prevented.

FIGS. 6 to 9 are views of the bending control tubes 40, 50, 60 and 70 showing the fourth to seventh embodiments of the present invention, respectively.

The bend restricting tube 40 of the fourth embodiment shown in FIG. 6 has a tapered surface 41 whose end on the Teflon tube 4 side is gradually thinned toward the tip, whereby the tip side is gradually softened.

The bend restricting tube 50 of the fifth embodiment shown in FIG. 7 has spiral or multiple annular recessed grooves 51 ... Formed on the outer peripheral surface of the half end on the Teflon tube 4 side. The end of the side half is soft so that it is easy to bend.

Also, the bending restriction tube 60 of the sixth embodiment shown in FIG.
Is a large number of small holes 61 at the end of the Teflon tube 4 half.
Is formed, which makes the end portion of the Teflon tube 4 side half soft so as to be easily bent.

Furthermore, the bending restriction tube of the seventh embodiment shown in FIG.
70 is formed in a close contact coil type, and thereby forms a bending restriction tube having a hardness intermediate between the stainless pipe 2 and the Teflon tube 4.

〔The invention's effect〕

As described above, according to the present invention, the bending degree of the flexible portion with respect to the quasi-flexible portion is limited by the bending restriction tube at the connection boundary portion between the quasi-flexible portion and the flexible portion. The operation wire is prevented from coming into contact with the end of the stainless pipe. Therefore, the movement resistance of the operation wire is reduced, the movement of the operation wire is smoothed, premature wear of the wire is prevented, and the life is extended.

[Brief description of drawings]

1 and 2 show a first embodiment of the present invention. FIG. 1 is a sectional view showing a connecting boundary portion between a semi-flexible portion and a flexible portion, and FIG. 2 shows a curved state. FIG. 3 is a sectional view showing the second embodiment of the present invention, and FIG. 4 is a sectional view showing a connecting boundary portion between the quasi-flexible portion and the flexible portion. FIG. 4 is a cross-sectional view showing a connecting boundary portion between the semi-flexible portion and the flexible portion, and FIG. 5 is a side view showing a curved state.
FIGS. 6 to 9 are views of bending control tubes showing the fourth to seventh embodiments of the present invention, and FIGS. 10 to 10.
FIG. 12 shows a conventional example, FIG. 10 is a cross-sectional view showing the entire wire guide structure, FIG. 11 is a cross-sectional view showing a connecting boundary portion between a semi-flexible portion and a flexible portion, and FIG. It is sectional drawing which shows a bending state. 1 ... Semi-flexible part, 2 ... Stainless pipe, 3 ... Flexible part, 4 ... Teflon tube, 5 ... Stainless wire net, 6 ... Heat shrink tube, 7 ... Wire guide passage , 9 …… Operation wire, 10,20,40,50,60,70 …… Bending control tube.

Claims (1)

(57) [Claims] 1. A wire guide for an endoscope in which a semi-flexible portion made of a pipe is connected to a flexible portion made of a soft tube, and an operation wire is inserted through the semi-flexible portion and the flexible portion. In the structure, the connection boundary portion between the quasi-flexible portion and the flexible portion has a hardness intermediate between the hardness of the quasi-flexible portion and the hardness of the flexible portion or higher. Then, the flexible part is sandwiched and fixed to the quasi-flexible part, and a bending restricting member whose end face on the flexible part side projects to the flexible part side from the connection boundary part is provided. Characteristic endoscope wire guide structure.