JPH0743693Y2 - Endoscope - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial application] The present invention relates to an endoscope having a hard portion at its tip and an optical fiber bundle having the end portion of a protective tube fixed to this hard portion.

[Prior Art] There is an endoscope that uses a light guide fiber having an image guide fiber in the center, as an endoscope having a reduced space and a reduced diameter.

Such an endoscope has a spiral tube a as shown in FIG.
The light guide fiber e is inserted together with the image guide fiber f into the outer tube d of the thin insertion portion c formed by covering the outer shell b (made of a tube material) and reinforcing the same. There is.

Specifically, in the structure of the light guide fiber e and the image guide fiber f, a hard portion g is formed at the tip of the light guide fiber e by molding with an adhesive, and the image guide fiber is formed at the center of the hard portion g. In addition to providing f together with the lens frame i having the objective lens h built therein, a base j of the light guide fiber c (formed in a pipe shape and fixing the end of the light guide fiber e) is provided on the tip side of the hard part g. Is being done.
Then, the tip end side of the light guide fiber e is inserted from the base end portion of the insertion part c, and when the base j of the tip reaches the tip end of the insertion part c, it is adhesively fixed to the tip forming part k of the tip. I am trying to assemble it.

By the way, if the light guide fiber e and the image guide fiber f come into direct contact with the spiral tube a or the like, there is a risk that the strand may be damaged.

Therefore, conventionally, a protection tube m is covered around the exposed light guide fiber e, and the tube end is bonded to the hard portion g at the latter stage of the base.

[Problems to be Solved by the Invention] By the way, in the light guide fiber e, the light guide fiber e is drawn into the insertion portion c by using a base j having a thickness t larger than the thickness of the protective tube m. Although the spiral tube a is not caught at the time of assembly, the end surface of the protective tube m may be warped when the protective tube m is bonded and fixed.

However, in addition to this, since the protective tube m is made of rubber with poor slippage, if warping occurs at the tube end, when the light guide fiber e is pulled into the insertion portion c, the spiral tube a There is a problem in that the work of pulling in becomes difficult due to interference and flipping up or catching, and eventually the work cannot be performed.

Therefore, it is conceivable to sufficiently attach the adhesive to the hard portion g to fix the protective tube m, but in this case, the diameter of the insertion portion c must be increased, and the outer diameter of the insertion portion c must be increased. It caused the problem of thickening.

The present invention has been made in view of such a problem, and an endoscope capable of easily and smoothly assembling an optical fiber bundle into an insertion portion without increasing the outer diameter of the insertion portion. The purpose is to provide.

[Means and Actions for Solving Problems] At least an end portion of the protective tube 14 covering the optical fiber bundle 7 is covered with a foil member 16 having a small frictional resistance to cause the protective tube 14 to be caught. It suppresses the displacement in the outer peripheral direction.

[Embodiment] Hereinafter, the present invention will be described based on a first embodiment shown in FIGS. 1 to 3. FIG. 1 shows the structure on the distal end side of an endoscope to which the present invention is applied, and 1 is a small-diameter insertion portion. The insertion portion 1 includes, for example, a distal end forming portion 5 at a distal end portion of a sheath tube 4 (similar to a conventional one) in which an outer circumference of a spiral tube 2 is covered with an outer cover 3.
It has a structure that is connected. As shown in FIG. 3, a cap 6 is provided at the end of the mantle tube 4 on the operating portion side. Then, as in the conventional case, the light guide fiber 7 is inserted into the insertion portion 1 together with the image guide fiber 8 (both are optical fiber bundles).

Specifically, a large number of glass fibers of about 30 μ are bundled in the light guide fiber 8. Then, both ends of the bundle are molded into a hollow cylinder with an adhesive or the like to form the hard parts 9 at the front end and the rear end. Then, the lens frame 12 having the objective lens 10 and the image guide fiber 8 mounted therein is inserted and fixed in the hard portion 9 at the tip, and the image guide fiber 8 is arranged at the center of the light guide fiber 10. Then, a fixing base 13 is provided at the tip of each of the hard portions 9. Also, the glass fiber of the light guide fiber 7 and the image guide fiber 8
Part mixed with the glass fiber of (excluding the end)
Are contained within a thin protective tube 14. Then, the end portion of the protective tube 14 is adhered and fixed to the outer peripheral portion of the hard portion 9 following the post of the mouthpiece 13 to protect the glass fiber from the outside as in the conventional case.

Then, a thin-walled cylindrical member 16 (corresponding to a foil member) having a small frictional resistance on the outer peripheral surface, which is the main part of the invention, is fitted (covered) on the distal end portion of the protective tube 14 which is likely to warp. .

More specifically, as shown in FIG. 2, the cylindrical member 16 is formed by molding a foil material such as metal or resin into a cylindrical shape.
It has a structure in which a slit 16a is formed in the peripheral wall along the axial direction, and the outer peripheral surface is defined as a surface having a small frictional resistance. The length of the cylindrical member 16 is determined according to the tube adhesive 9a of the hard portion 9 on the distal end side, and the inner diameter is larger than the outer diameter when the protective tube 14 is covered with the hard portion 9. It is set small. And such a cylindrical member 16
Is inserted into the tube end portion of the tube bonding portion 9a following the base 13. That is, the cylindrical member 16 is fixed by tightening the protective tube 14 on the hard portion 9.

The sum of the wall thicknesses of the protection tube 14 and the cylindrical member 16 is set to be smaller than the wall thickness t of the mouthpiece 13, and when the light guide fiber 7 is drawn into the insertion portion 1, the cylindrical member 16 has a spiral shape. The tube 2 is not caught.

The base 13 at the tip of the light guide fiber 8 to which each of these components is assembled is adhesively fixed in a mounting hole provided in the tip forming portion 5.

Then, when assembling the light guide fiber 7 into the insertion portion 1 in such an endoscope, from the mouthpiece 6 on the operation portion side of the outer tube 4 shown in FIG.
Insert the mouthpiece 13 at the tip of the light guide fiber 7. Then, when the base 13 reaches the tip forming part 5, the base 13 is bonded and fixed to the mounting hole of the tip forming part 5.

Here, there is a concern that the end surface of the protective chew b14 may be turned up or caught when it is inserted into the insertion portion 1.

However, according to this invention, a cylindrical member having a small frictional resistance is provided.
Since 16 is fitted and the protection tube 14 is held down to the hard part 9 side, the end surface of the protection tube 14 does not interfere with the spiral tube 2 and there is no curling or catching. The light guide fiber 7 can be inserted smoothly.

Therefore, the light guide fiber 7 and the image guide fiber 8 can be easily assembled, and the assemblability can be improved. Moreover, it does not cause damage.

In addition, since a thin foil material having low frictional resistance is used, it is not necessary to increase the outer diameter of the insertion portion 1. In addition, the structure is simple and inexpensive.

The invention is not limited to the first embodiment, but may be the second embodiment shown in FIG.

That is, in the second embodiment, a step portion 20 is formed on the outer peripheral end of the mouthpiece 13 on the side of the operating portion so that the protective tube 14 covered is substantially the same, and the step portion 20 and the protective tube 14 are formed.
The cylindrical member 16 is fitted over the ends of the cylindrical member 16 and the both members are fixed at the same time by the cylindrical member 16. Such a structure has an advantage that the protection tube 14 is more securely fixed.

In the second embodiment, the same parts as those in the first embodiment are designated by the same reference numerals and their description is omitted.

Further, although the cylindrical foil member having the slits is used in the above-described embodiment, the present invention is not limited to this, and the cylindrical foil member having no slit may be used.

In addition, instead of an endoscope having a light guide fiber incorporating the above-mentioned image guide fiber, a light guide fiber individually provided in the insertion portion, or an image guide fiber (both are optical fiber bundles)
The protective tube may be covered with the above-mentioned cylindrical member.

[Advantages of the Invention] As described above, according to the present invention, the optical fiber bundle can be easily and smoothly assembled to the insertion portion without increasing the outer diameter of the insertion portion.

Therefore, the assemblability can be improved. Moreover, the structure is simple and inexpensive.

[Brief description of drawings]

1 to 3 show a first embodiment of the present invention,
FIG. 1 is a cross-sectional view showing the structure of an endoscope insertion part which is a main part,
FIG. 2 is a perspective view showing the foil member together with a protective tube, FIG. 3 is a sectional view showing an end portion of the insertion portion on the operating portion side, and FIG. 4 is a main portion of a second embodiment of the present invention. FIG. 5 is a sectional view showing the structure of the distal end portion of the conventional endoscope insertion portion. 7 …… Light guide fiber (optical fiber bundle), 9 ……
Hard part, 14 …… Protective tube, 16 …… Cylindrical member (foil member).

Claims (1)

[Scope of utility model registration request] 1. An optical fiber bundle having a hard portion at an end thereof, the periphery of which is covered with a protective tube, and the end portion of the protective tube being fixed to the hard portion is provided. An endoscope in which the distal end portion of the optical fiber bundle is fixed to the distal end constituent portion of the distal end of the insertion portion, and at least the end portion of the protective tube has a small friction resistance. An endoscope characterized by being coated with.