JPH0434497Y2 - - Google Patents

Description

[Detailed Description of the Invention] "Industrial Application Field" The present invention relates to an endoscope with an improved structure near the tip of the insertion section.

[Conventional technology]

When reducing the diameter of the insertion section of an endoscope, the most problematic part is the tip, and various improvements have been made in the past. The tip of a conventional endoscope with a reduced diameter is constructed as shown in FIG. That is, a cylindrical lens frame 2 and a light guide fiber 3 arranged annularly around the lens frame 2 are attached to a metal tip frame 1, and an objective lens 4 is attached to the lens frame 2.
An image guide fiber 5 is inserted and fixed with adhesive. In addition, the tip frame 1 includes a flexible tube 6 of the insertion section.
is connected. Furthermore, the light guide fiber 3 is adhesively fixed to the inner wall of the tip frame 1.

[Problem that the invention attempts to solve]

By the way, in the distal end of the conventional endoscope, the thickness of the distal end frame 1 inevitably becomes thicker, and the diameter becomes larger accordingly.

Therefore, in order to make the diameter smaller, the flexible tube 6 is formed from a resin such as Teflon without using the tip frame 1, and the flexible tube 6 is directly connected to the outer periphery of the light guide fiber 3. It is conceivable to fit and adhere.

However, when the light guide fiber 3 and the flexible tube 6 are directly bonded together in this manner, the bonding strength between the fiber and the resin tube is weak, resulting in a significant decrease in durability. For example, if this endoscope is repeatedly immersed in a chemical solution and gas sterilized, there is a risk that the adhesive portion may peel off, causing water leakage, which poses a practical problem.

The present invention has been developed in view of the above-mentioned problems, and its purpose is to provide an endoscope whose distal end portion can be made smaller in diameter without impairing adhesive strength.

[Means and actions for solving problems]

In order to achieve the above object, the present invention involves fitting the distal end portion of a resin flexible tube for the insertion section onto the outer periphery of the light guide fiber bundle, and also fitting the distal end portion of the resin flexible tube for the insertion section onto the outer periphery of the light guide fiber bundle and the distal end of the flexible tube. A metal foil was interposed between the inner surface of the part and these were adhesively fixed.

Since the light guide fiber bundle and the flexible tube are each bonded to the metal foil in this way, the bonding strength is high.

〔Example〕

1 and 2 show a first embodiment of the present invention.

FIG. 2 shows an endoscope 11, which is composed of a small-diameter insertion section 12, an operating section 13, and a light guide cable 14. As shown in FIG. Operation unit 1
3 is provided with an eyepiece 15 for observing an image, and the extending end of the light guide cable 14 is provided with a connector 1 connected to a light source device (not shown).
6 is provided.

The insertion section 12 is formed of a flexible tube 17 made of a resin tube such as Teflon, and the distal end 18 of the insertion section 12 is configured as shown in FIG. That is, a metal cylindrical lens frame 19 is installed in the center. An objective lens 21 and a cover glass 22 located on the most distal side are provided within the distal end portion of the lens frame 19 and fixed with adhesive. Furthermore, the tip of an image guide fiber bundle 20 is inserted into the rear end of the lens frame 19 and fixed with adhesive. Note that the rear end side of the image guide fiber bundle 20 is led to and connected to the eyepiece section 15 through the insertion section 12 and the operation section 13.

Further, a light guide fiber bundle 23 is arranged in an annular shape around the lens frame 19, and is adhesively fixed to the outer peripheral surface of the lens frame 19. The outer periphery of the light guide fiber bundle 23 is tightly covered with a cylindrical metal foil 24. The tip portion of the flexible tube 17 is tightly fitted onto the outer peripheral surface of the metal foil 24.

The outer periphery of the light guide fiber bundle 23 and the metal foil 24, and the space between the metal foil 24 and the flexible tube 17 are adhesively fixed, respectively. That is, the light guide fiber bundle 23 is fixed to the flexible tube 17 via the metal foil 24, and is not directly bonded. As the metal foil 24, it is desirable to use a material that is resistant to corrosion, such as stainless steel or copper-based metal.

Note that even if the metal foil 24 is adhesively fixed to the outer periphery of the light guide fiber bundle 23 in advance, the metal foil 24 will not be attached to the light guide fiber bundle 2 during assembly.
You can also glue it to 3. However, if the metal foil 24 is adhesively fixed during molding of the light guide fiber bundle 23, there is an advantage that the light guide fiber bundle 23 will be less likely to break during subsequent assembly.

Since the flexible tube 17 and the trite guide fiber bundle 23 are not directly bonded to each other but are bonded to each other with the metal foil 24 interposed therebetween, the adhesive strength is significantly increased.

3 to 6 show a second embodiment of the present invention.

This embodiment is a flexible tube 17 into which a metal foil 24 is inserted.
Only the inner diameter of the tip of the metal foil 24 is cut out larger than the other parts by twice the thickness of the metal foil 24,
The metal foil 24 is fitted into this notch inner diameter portion 25,
It is designed to be glued. In this way, the thickness of the metal foil 24 will not appear as a bulge on the outer periphery of the flexible tube 17 and form a step, and the outer periphery of the flexible tube 17 will have the same diameter and smooth over its entire length. , the diameter of the tip portion 18 can be reduced.

Further, in this embodiment, a part of the cover glass 22 is cut out by the thickness of the lens frame 19 as shown in FIG. It was formed to be equal to the outer diameter of. On the other hand, as shown in FIG. 6, the tip edge portion of the lens frame 19 leaves a portion corresponding to the notch 26 as a protrusion 27, and the other portion is left as a protrusion 27.
I cut out the thickness of 2.

Then, the protrusion 27 is fitted into the notch 26 of the cover glass 22, and the cover glass 22 is bonded and fixed by adhesive to the distal end surface of the lens frame 19. Thus, the outer diameter of the cover glass 22 can be increased to the outer diameter of the lens frame 19. Therefore, manufacturing the cover glass 22 is easy. Generally, the thinner the cover glass 22 is, the more preferable it is in terms of its optical performance (increasing the viewing angle). However, when trying to make it thinner and smaller in diameter, it tends to break and it is difficult to polish its outer diameter, so it becomes thick. For this reason, even if the diameter of the objective lens 21 is reduced, the diameter of the cover glass 22 cannot be reduced, so that the outer diameter of the insertion portion 12 cannot be reduced in the end.

However, according to the configuration of the second embodiment, the outer diameter of the cover glass 22 can be increased, so the cover glass 22 can be easily manufactured.
Further, the diameter of the insertion portion 12 can be reduced. Furthermore, since it is easy to polish, it can be manufactured at low cost. Moreover, the notch 26 and the protrusion 27 make it easy to position the cover glass 22 and easily fix it to the lens frame 19.

7 and 8 show a third embodiment of the present invention.

In this embodiment, a flexible tube 28 forming a channel is provided, and each peripheral surface of the flexible tube 28 and the lens frame 19 is covered and fixed with a light guide fiber bundle 23, and other points are fixed. is the same as in the previous embodiment.

[Effect of idea]

As explained above, in the present invention, the flexible tube forming the insertion portion and the light guide fiber bundle are not directly bonded, but are bonded by interposing metal foil between them. The adhesive strength in the area can be significantly increased. Therefore, even if the endoscope is repeatedly subjected to disinfection treatment by immersion in a chemical solution and gas sterilization treatment, peeling of the adhesive portion and water leakage are unlikely to occur. In other words, the durability of the bonded portion can be significantly improved.

Further, since only a thin metal foil is interposed, the diameter of the insertion portion can be reduced.

[Brief explanation of the drawing]

FIG. 1 is a side sectional view of the distal end of the insertion section in the first embodiment, FIG. 2 is a side view of the entire endoscope of the same embodiment, and FIG. 4 is a front view of the tip of the second embodiment; FIG. 5 is a front view of the cover glass of the second embodiment;
FIG. 6 is a perspective view of the lens frame in the second embodiment, FIG. 7 is a side view of the distal end of the insertion portion in the third embodiment, and FIG. 8 is a distal end in the third embodiment. FIG. 9 is a side sectional view showing the distal end of a conventional insertion section. DESCRIPTION OF SYMBOLS 11... Endoscope, 12... Insertion part, 17... Flexible tube, 18... Tip part, 23... Light guide fiber bundle, 24... Metal foil.

Claims (1)

[Claims for Utility Model Registration] (1) A resin flexible tube forming an insertion portion is fitted around the outer periphery of the light guide fiber bundle, and the outer periphery of the tip of the light guide fiber bundle and the tip of the flexible tube are fitted. An endoscope characterized in that a metal foil is interposed between the inner surface of the part and the parts are fixed by adhesive. (2) The utility model according to claim 1, characterized in that only the inner diameter of the tip portion of the flexible tube is larger than the other flexible tube portions by twice the thickness of the metal foil. Endoscope.