JP2785826B2 - Endoscope - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to an endoscope used for medical or industrial purposes. [Related Art] An endoscope is configured to include an operation unit on a hand side and an elongated flexible insertion unit inserted into a body cavity or the like, and a distal end side portion of the insertion unit includes an operation unit. Is provided with a bending portion that can be bent in a desired direction in accordance with the rotation angle of the angle operation knob provided in the vehicle, and this bending portion is capable of rotating a number of node rings (bending pieces) by a pivot. And the outside thereof is covered with a flexible jacket. An optical fiber bundle used as a light guide or an image guide is inserted through the inside of the insertion portion. In the optical fiber bundle, the fibers are fixed to each other at the distal end portion by an adhesive, and the hard portion is fixed to the distal end hard portion of the insertion portion. Therefore, when bending the curved part,
In the optical fiber bundle, the flexible portion excluding the hard portion is curved in the same direction as the curved portion. When the curved portion is bent in this manner, the optical fiber bundle inside the fiber may be broken due to fatigue of the fiber due to repetition of stress due to frictional resistance between the fibers. For this reason, conventionally,
For example, as proposed in Japanese Patent Application No. 57-197073, a proposal has been made to cover the optical fiber bundle with a relatively hard tube so that it does not collapse flatly even when curved, thereby reducing the frictional resistance of the optical fiber bundles and making them hard to break. Was done. For the same purpose,
Double tubes as in 58-117602,
Attempts have been made to reinforce it with a metal helical tube as in the case of No. 56-19975. [Problems to be Solved by the Invention] However, even if the above measures are taken, the optical fiber bundle may be broken. In particular, for the endoscope with an outer diameter of 6 mm or less, such as an endoscope for bronchi, biliary tract, urethra, and nasal cavity that needs to be inserted into a relatively small lumen in the body cavity, the tip of the optical fiber bundle In some cases, some of the fibers may break. When pursuing the cause, the following was found. Originally, there has been a demand for an endoscope to shorten the total length of the rigid portion at the distal end of the curved portion as much as possible to enhance the insertability. However, if the tip rigid portion is shortened, the rear end of the hard portion of the optical fiber bundle fixed to the tip rigid portion protrudes toward the curved portion, and when the curved portion is bent, the rigid portion and the flexible portion are bent. Bending stress concentrates near the boundary between the two, and this causes breakage. Therefore, an object of the present invention is to prevent breakage in the vicinity of the front end of an optical fiber bundle. [Means for Solving the Problems] The present invention provides a flexible insertion portion with a bending portion that can be bent in a desired direction formed by connecting a number of node rings by a pivot at a distal end portion thereof. A non-flexible distal rigid portion located on the distal side of the curved portion, and further, an optical fiber bundle composed of a large number of optical fibers is inserted into the inside of the insertion portion, and the distal end portion of the optical fiber bundle is In an endoscope fixed to an end member of the distal end rigid portion, a rigid portion in which fibers are fixed to each other by an adhesive is provided at a distal end portion of the optical fiber bundle so as to extend from a base, and a base end of the base An outer tube that covers the outside of the portion and the outside of the optical fiber bundle and forms a gap between the hard portion and the entire length of the hard portion is the second length from the distal end connecting the node ring; So that it fits more distally than the Axis is there. [Operation] In the endoscope having the above configuration, when the bending portion is bent, the optical fiber bundle inside the bending portion also bends in the same direction. Since the optical fiber bundle is restricted to fit on the side, the vicinity of the boundary between the hard portion and the flexible portion of the optical fiber bundle can be bent with a relatively large radius of curvature. For this reason, stress concentration due to bending is avoided and fiber fatigue is greatly reduced, which is effective in preventing fiber breakage. Embodiment A first embodiment of the present invention will be described below with reference to FIGS. As illustrated in FIG. 3, the endoscope 1 includes an operation unit 2 on a hand side and an elongated insertion unit 3 inserted into a body cavity. The operation unit 2 is provided with an operation knob 4 which constitutes a part of a known angle operation mechanism. The distal end portion of the insertion portion 3 is provided with a bending portion 5 that can be bent over a predetermined length and a non-flexible distal hard portion 6 located on the distal side of the bending portion 5. This tip rigid part 6
Is fixed to one end of a bending operation wire 7 (only part of which is shown), and the bending portion 5 is bent in a desired direction by rotating the operation knob 4 and pulling the wire 7. 1 and 2 show a first embodiment of the present invention. 40 is a flexible tube for a forceps channel, 41 is a node ring 9b ...
And the wire receiver is formed on every other wire, and is not provided on the node ring 9c at the forefront and the node ring 9b at the first end from the tip. In the present embodiment, a hard portion formed by bonding fibers formed at the distal end of the light guide optical fiber bundle (not shown) and the image guide optical fiber bundle 25 with an adhesive is used.
25a is the second rivet 18 ″ from the tip side with its full length l ₂
The second rivet 18 "to the front end
It is provided to extend to a part close to. Reference numeral 42 denotes a base that covers the outside of the hard portion 25a. In the first embodiment having such a configuration, when the wire 7 is pulled by operating the angle operation knob 4, the bending portion 5 bends as shown in FIG. However, the hard portion 25a and the flexible portion 25b of the optical fiber bundle 25
The boundary 31 does not correspond to the node rings 9c, 9b... That is, in the bending portion 5, as can be seen from FIG. 2, the distal end side also bends from the second rivet 18 ". However, since the wire receiver 41 is not formed on the first node ring 9b, this 1 The inner space of the second node ring 9b has a relatively large margin, but even if the bending portion 5 is bent to the maximum,
The angle of the second rivet 18 "is still small with respect to the tip rigid portion 6. Therefore, even if the hard portion 25a of the tip fiber bundle 25 extends linearly to the vicinity of the second rivet 18". However, the boundary 31 between the hard portion 25a and the flexible portion 25b is not strongly pushed on the inner surface of the node ring 9a, and no excessive force is applied to this boundary. Therefore, breakage of the optical fiber bundle 25 is prevented. In the first embodiment, the case where the node rings 9b are curved in two directions has been described. However, the present invention can be implemented even if they are curved in four directions. [Effects of the Invention] As described above, according to the present invention, even when the curved portion is bent, the optical fiber bundle is not strongly bent locally, and the distal end portion of the fiber is not broken. For this reason, it is possible to exhibit excellent breakage resistance not only in the early stage of use of the endoscope but also in repeated bending, thereby reducing the radius of curvature of the curved portion, or shortening the length of the rigid portion at the tip. Can improve the insertability.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a sectional view showing a vicinity of a curved portion of an endoscope showing a first embodiment of the present invention, and FIG. 2 is a sectional view showing a state where the curved portion shown in FIG. 1 is curved. FIG. 3 is an overall view of the endoscope having the bending portion shown in FIG. 1, 1... Endoscope, 2... Operating unit, 3. … Rigid part at the tip, 9a… end node ring, 9b… node ring, 9c… terminal node ring, 10… jacket, 18 ″… second rivet (axis), 20… ... end members, 24, 25 ... optical fiber bundles, 24a, 25a ... hard parts, 24b, 25b ... flexible parts.

   ────────────────────────────────────────────────── ─── Continuation of front page    (72) Inventor Makai Adult               2-43-2 Hatagaya, Shibuya-ku, Tokyo Oh               Linpass Optical Co., Ltd. (72) Inventor Ichiro Nakamura               2-43-2 Hatagaya, Shibuya-ku, Tokyo Oh               Linpass Optical Co., Ltd. (72) Inventor Keiichi Arai               2-43-2 Hatagaya, Shibuya-ku, Tokyo Oh               Linpass Optical Co., Ltd.                    Panel     Referee Takehiko Katayose     Judge Hidetomo Higashimori     Judge Akira Watanuki                (56) References JP-A-59-87409 (JP, A)                 JP-A-62-180320 (JP, A)                 JP-A-61-245120 (JP, A)                 60-184508 (JP, U)

Claims (1)

(57) [Claims] A bending portion which can be bent in a desired direction formed by connecting a number of node rings by a pivot at the distal end portion of the flexible insertion portion, and a non-flexible portion located at the distal side of the bending portion. End rigid part, and further, an optical fiber bundle composed of a large number of optical fibers is inserted into the inside of the insertion portion, and the distal end portion of the optical fiber bundle is fixed to an end member of the rigid distal end portion. In the mirror, a hard portion in which the fibers are fixed to each other by an adhesive is provided at the distal end portion of the optical fiber bundle so as to extend from the base, and covers the outside of the base end of the base and the outside of the optical fiber bundle. An outer tube forming a gap with the hard portion is provided, and the entire length of the hard portion is located closer to the distal end than the second pivot from the distal end connecting the node ring. Endoscope.