JP2618026B2 - Endoscope - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an endoscope in which a bending tube at the distal end of an insertion section is operated to bend.

[Prior Art] Generally, an insertion portion of an endoscope includes a flexible tube portion and a bending tube portion, and the bending tube portion, which is the distal end portion of the insertion portion, is operated by a bending operation mechanism provided in an operation portion. I can do it. That is, an operation wire is inserted through the insertion portion, a distal end of the operation wire is fixed to a bending tube portion of the insertion portion, and a base end is linked to the bending operation mechanism. By operating the bending operation mechanism to push and pull the operation wire, the bending operation of the bending tube portion can be performed. The insertion portion is provided with a coiled pipe composed of a closely wound coil, through which the operation wire is inserted so that the operation wire can be smoothly pushed and pulled. The coil-shaped pipe has a distal end fixedly attached to a connection base provided at a boundary portion between the curved tube portion and the flexible tube portion, and a proximal end fixed to the operation portion. The middle portion of the coiled pipe can be freely displaced.

[Problem to be Solved by the Invention] In the conventional endoscope, the coiled pipe has the same diameter over the entire length. Therefore, it is inevitable that the internal components interfere with other internal components such as a light guide fiber and an image guide fiber in the operation unit. In that case, the middle part of the coiled pipe can be displaced, so that interference with other internal objects can be avoided.However, the tip part fixed to the connection base does not interfere with other internal objects. No. Therefore, there is a problem that the coiled pipe may damage the internal organs, and in order to avoid the damage, the diameter of the insertion portion must be increased. Further, in order to avoid interference between the coiled pipe and the internal organs, the position of the distal end of the coiled pipe fixed to the connection base in the circumferential direction may be shifted. Such prior art is disclosed in Japanese Utility Model Laid-Open No. 60-32903.

However, according to such means, there is a problem in that the curved pipe portion cannot be accurately bent in the up, down, left, and right directions due to the displacement of the position of the coiled pipe.

In order to solve such a problem, the present applicant has proposed an endoscope disclosed in Japanese Utility Model Application No. 61-302150.
In this prior art, the outer diameter of the distal end of the coiled pipe connected to the connection mouth is made smaller than that of the other portions.

According to such a configuration, not only can the diameter of the insertion portion be prevented from being increased, but also the position of the distal end portion of the coiled pipe in the circumferential direction does not need to be largely shifted from the predetermined position.

However, in order to reduce the diameter of the coiled pipe, it is necessary to reduce the diameter of the wire, so that the strength of the tip of the coiled pipe is reduced, and it becomes easy to buckle,
In some cases, the slide operation of the operation wire cannot be performed smoothly.

The present invention has been made based on the above circumstances, and its purpose is to increase the diameter of the insertion portion or to shift the position of the distal end of the coiled pipe in the circumferential direction. It is another object of the present invention to provide an endoscope capable of preventing the tip of a coiled pipe from buckling.

[Means and Actions for Solving the Problems] In order to solve the above problems, the present invention provides an insertion portion including a flexible tube portion and a curved tube portion, and a distal end portion at a distal end portion of the flexible tube portion. A plurality of coiled pipes are fixedly arranged, and the distal end of the operation wire slidably inserted into each coiled pipe is fixedly attached to the distal end of the curved tube portion, and the operation wire is advanced and retracted to perform the operation. In an endoscope that bends a curved tube portion, a flexible cylindrical pipe having an outer diameter smaller than that of the coiled pipe is connected to at least a part of a tip of the plurality of coiled pipes. A flexible cylindrical pipe is fixed to the distal end of the flexible tube. By using a flexible cylindrical pipe having a diameter smaller than that of the coiled pipe, not only can the insertion section be reduced in diameter without causing buckling, but also the bending direction does not significantly deviate from the normal direction. It was made.

Hereinafter, a first embodiment of the present invention will be described with reference to FIGS. The endoscope shown in FIG. The light guide cable 2 and the insertion section 3 are connected to the operation section 1. This insertion part 3 is a flexible tube part 4
And a curved tube portion 5 connected to the distal end of the flexible tube portion 4. The flexible tube portion 4 is formed of a flexible tube, and has a base end connected to the connection portion 6 formed on the operation portion 1.
, And a ring-shaped connection base 7 is attached to the end.

On the other hand, the bending tube section 5 is formed by connecting a large number of bending pieces 8 so as to be rotatable in up, down, left and right directions by pins 9, and covering the outer peripheral surface thereof with a flexible tube 11. The distal end component member 12 is fitted to the foremost bending piece 8, and the base bending piece 9 is connected to the connection base 7. Guide rings 13 are fixed to the inner peripheral surface of each bending piece 8 at 90-degree intervals in the circumferential direction. These guide rings
An operation wire 14 is inserted through each of the 13. The tips of these operation wires 14 are fixed to the most advanced bending piece 8,
The base end is guided to the operation unit 1. A bending operation mechanism 16 is provided in the operation unit 1. The bending operation mechanism 16 includes a pinion 18 fitted on an operation shaft 17 and a pair of racks 19 meshed with the pinion 18 in two upper and lower stages (only one stage is shown).
, And a base end of the operation wire 14 is connected to each rack 19. Therefore, if the operation shaft 17 is rotated and the rack 19 is slid, the operation wires 14 can be pushed and pulled to bend the bending tube portion 5 vertically and horizontally.

An intermediate portion of the four operation wires 14 located at the flexible tube portion 4 is inserted through four coiled pipes 21 each of which is a tightly wound coil formed of a wire material such as stainless steel. . These coiled pipes
Reference numeral 21 denotes a base end portion which is held and fixed to the operation unit 1 and two of the four end portions are brazed and fixed to the inner peripheral surface of the connection base 7. The tip of the remaining two coiled pipes 21 is a flexible cylindrical pipe made of stainless steel for spring or phosphor bronze or the like with a smaller outer diameter than the coiled pipe 21 so as to obtain sufficient flexibility. The base end of 22 is fitted and connected. The distal ends of the flexible cylindrical pipes 22 are brazed and fixed over the entire length of the inner peripheral surface of the connection mouthpiece 7 in the axial direction. A part of the outer peripheral surface of the flexible cylindrical pipe 22 to be brazed is cut off as shown in FIG.
a, thereby reducing the diameter.

The outer diameter of the operation wire 14 is 0.54 mm, the inner diameter of the flexible cylindrical pipe 22 is 0.6 mm, the thickness is 0.1 mm, the outer diameter is 0.8 mm,
The inner diameter of the coiled pipe 21 is set to 0.6 mm, the strand diameter is set to 0.35 mm, and the outer diameter is set to 1.3 mm.

Therefore, in the inner peripheral portion of the connection base 7,
The space is enlarged by the dimensional difference between the outer diameter of the coiled pipe 21 and the outer diameter of the flexible cylindrical pipe 22 as compared with the case where the tip portions of the four coiled pipes 21 are connected to the connection base 7. Become. The middle part of the four coiled pipes 21 can be freely shifted.

Various internal organs are inserted through the insertion portion 3 as shown in FIG. That is, FIG. 3 is a cross-sectional view of a portion of the connection base 7 of the insertion portion 3, and the insertion portion 3 has an image guide fiber 23 as a built-in object and a pair of light guide fibers.
24, a channel tube 25, an air supply tube 26, a water supply tube 27, and the like are inserted therethrough.

Since the two flexible cylindrical pipes 22 have a small diameter, their distal ends are connected to the channel tube 25 which is a built-in member having the maximum outer diameter and the inner peripheral surface of the connection base 7 as shown in FIG. Can be fixed in a narrow gap. So 4
Since the operating wires 14 can be arranged at intervals of approximately 90 degrees in the circumferential direction, it is possible to minimize the bending of the bending tube portion 5 in an irregular direction while suppressing the diameter of the insertion portion 3 from increasing. Can be.

On the other hand, the length of the curved tube 5 is 7 cm, the length of the flexible tube 4 is 1 m, and the length of the flexible cylindrical pipe 22 is 25 cm. The light guide fiber 24 is covered with a protective tube (not shown) having a length of 30 cm and fixed to the distal end component 12.
That is, the coiled pipe 21 does not overlap the protection tube in the axial direction. Thereby, the diameter of the flexible tube portion 4 is reduced.

According to the endoscope thus configured, as at least a part of the four coiled pipes 21, two of the coiled pipes 21 are provided with a flexible cylindrical pipe 22 having a smaller diameter than the coiled pipe 21.
And these were connected to the connection base 7. Therefore, it is easy to insert other internal components into the connection base 7 by the difference between the outer diameters of the flexible cylindrical pipe 22 and the coiled pipe 21. It becomes difficult for the tip of 21 to interfere with internal organs. That is, it is possible to prevent the coiled pipe 21 and the flexible cylindrical pipe 22 from interfering with the internal organs without increasing the diameter of the insertion portion 3. Moreover, since the flexible cylindrical pipe 22 does not easily interfere with the internal organs, these can be arranged on the inner peripheral surface of the connection base 7 at intervals of about 90 degrees in the circumferential direction.
Therefore, when the bending operation section 16 performs the bending operation on the bending tube section 5, the bending tube section 5 can be bent almost exactly in the vertical and horizontal directions.

Further, the middle part of the coiled pipe 21 is movable. Therefore, even if the middle part is thicker than the small diameter part 22, the position can be shifted so as not to interfere with other internal organs.

In addition, since only two flexible cylindrical pipes 22 are used, the resilience of these curved pipes has little effect on the flexibility of the entire insertion portion 3, and the insertability does not decrease. Furthermore, the flexible cylindrical pipe 22 has sufficient strength against buckling, and has sufficient strength against buckling because the distal end of the coiled pipe 21 is not reduced in diameter as in the related art. . That is, the strength against buckling can be improved while the diameter of the insertion portion 3 is reduced.

In the above embodiment, the flexible cylindrical pipe 22 is connected to the ends of the two coiled pipes 21.
It may be connected to a book.

[Effect of the Invention] As described above, in the present invention, a flexible cylindrical pipe smaller in diameter than the coiled pipe is connected to at least a part of the tip of the plurality of coiled pipes. Therefore, at the boundary between the flexible tube portion and the curved tube portion, the coiled pipe or the flexible cylindrical pipe interferes with other internal components by an amount smaller than the coiled pipe by the flexible cylindrical pipe. It is not necessary to increase the diameter of the insertion portion in order to prevent the interference. Furthermore, since the distal end portion of the coiled pipe does not easily interfere with other internal components, the distal end portion can be disposed at a predetermined position in the circumferential direction of the insertion portion, that is, at an interval of approximately 90 degrees in the circumferential direction, so that the curved portion is curved. The pipe section can be operated to bend in the up, down, left and right directions almost accurately. Further, the buckling strength does not decrease as in the conventional case where the diameter of the tip of the coiled pipe is reduced.

[Brief description of the drawings]

FIG. 1 is an enlarged cross-sectional view of a main part of the present invention, FIG. 2 is a schematic diagram of the entire structure, FIG. 3 is a cross-sectional view of a connecting portion between a flexible tube and a curved tube, and FIG. FIG. 3 is an enlarged view of a connection portion between the connection base and the flexible cylindrical pipe. 1 ... operation part, 3 ... insertion part, 4 ... flexible tube part, 5 ...
Bending tube part, 14 …… Operation wire, 21 …… Coiled pipe,
22 ... Flexible cylindrical pipe.

Claims (1)

(57) [Claims] 1. An insertion portion comprising a flexible tube portion and a curved tube portion,
A plurality of coiled pipes are disposed by fixing the distal end portion to the distal end portion of the flexible tube portion, and the distal end of the operation wire slidably inserted through each coiled pipe is fixed to the distal end portion of the curved tube portion. In addition, in the endoscope in which the operating wire is advanced or retracted to bend the bending tube portion, at least a part of the end of the plurality of coiled pipes has a smaller outer diameter than the coiled pipe. An endoscope comprising: a flexible cylindrical pipe connected thereto; and the flexible cylindrical pipe fixed to a distal end portion of the flexible pipe section.