JPH0376128B2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a flexible tube that forms the insertion section of an endoscope inserted into a body cavity, and in particular, a flexible tube that forms the insertion section of an endoscope inserted into a body cavity, and in particular, a flexible tube that forms a forceps channel, a suction channel, or an air/water supply channel. The present invention relates to a flexible tube for an endoscope in which a channel or the like can be arranged along the outside of the flexible tube.

[Prior Art] The flexible tube of a conventional endoscope is generally a helical tube made of a thin, high-hardness stainless steel band or a phosphor bronze band, the outside of which is covered with a mesh tube, and the outside of which is further covered with a synthetic resin material. It was covered with a flexible outer skin, and was formed into an elongated cylindrical shape with a circular cross section.

[Problems to be Solved by the Invention] In a general endoscope, channels are inserted into a flexible tube. However, when it is desired to add second and third forceps channels, the additional forceps channels must be placed along the outside of the flexible tube. In addition, in order to prevent infection from occurring from patient to patient due to endoscopy,
Channels may be disposable after each use. In such cases, the channel is placed along the outside of the flexible tube. (Unexamined Japanese Patent Publication 1986-
179128).

However, since the flexible tube of a conventional endoscope has a simple circular outer shape, if the channel is placed along the outside of the flexible tube, the channel protrudes from the flexible tube and impairs insertion into the body cavity. However, it had the disadvantage of causing significant pain to patients.

Therefore, it is also conceivable to form a groove in the outer circumferential surface of the flexible tube along the tube axis direction, and to house the channel in the groove from the outside. The flexible tube of the endoscope is
It must have sufficient strength against bending and crushing, and sufficient flexibility to comfortably flex along the inner wall of the patient's body cavity. For this purpose, it is essential to use a helical tube made of a thin-walled and highly hard material. However, it is not easy to form grooves in a material with high hardness, and if grooves are formed along the tube axis in a spiral tube, the spiral tube may become distorted due to residual machining distortion. Twisting occurs in the tube, and the groove cannot be formed straight. Further, the spiral tube also has a step difference between each turn, which causes the inconvenience that the optical fiber bundle or the like may be damaged at some point. Due to such inconveniences, it has conventionally been difficult to form a groove for accommodating a channel or the like on the outer circumferential surface of a flexible tube.

This invention is intended to solve such problems in the past, and it is possible to arrange a channel etc. along the outer circumferential surface of a flexible tube without protruding, so that it is easy to insert and does not cause pain to the patient. The purpose of the present invention is to provide a flexible tube for an endoscope.

[Means for Solving the Problems] In order to achieve the above object, the flexible tube of the endoscope of the present invention has a concave groove formed along the tube axis direction, and is subjected to age hardening treatment after liquefaction treatment. It is characterized by having a spiral tube.

In this case, the helical tube may be formed from a beryllium copper alloy, or the helical tube may be formed by closely adhering a plurality of helical tubes wound in different directions.

[Function] If the spiral tube is subjected to liquefaction treatment (synonymous with solution heat treatment) with the concave groove formed straight along the tube axis direction, processing strain is removed, so the spiral tube does not twist. Stay straight. If the spiral tube is then age-hardened, high strength can be obtained. Therefore, it is possible to use a type of material that is relatively soft in hardness before hardening and is easy to process.

[Example] Examples will be described with reference to the drawings.

FIG. 2 is an external view of an endoscope using the flexible tube 10 of the embodiment. In the figure, reference numeral 2 indicates a distal end main body that includes an objective lens (not shown), etc., and 3 indicates a curved portion that can be bent freely by remote control. Reference numeral 4 denotes an operating section in which various operating devices are built in, and a bending operation knob 5 for remotely controlling the bending of the bending section 3 is rotatably provided on its side wall.

Reference numeral 10 denotes a flexible tube that constitutes the insertion section of the endoscope, and connects the operating section 4 and the bending section 3.
On the outer circumferential surface of the flexible tube 10, a groove 11 recessed inward in a U-shape is formed directly along the tube axis direction of the flexible tube 10. Grooves 21 and 31 continuous to the groove 11 are also formed in the tip main body 2 and the curved portion 3.

FIG. 1 is a cross-sectional view of the flexible tube 10, in which so-called built-in objects such as optical fiber bundles are inserted, but illustration thereof is omitted. The flexible tube 10 is
The outer side of the spiral tube 12 is tightly covered with a reticular tube 13, and the outer side of the spiral tube 12 is further covered with a flexible outer skin 14 made of synthetic resin in a watertight manner. The spiral tube 12, reticular tube 13, and outer skin 14 are integrally recessed inward in a U-shape to form the recessed groove 11.

FIG. 3 is a perspective view showing the spiral tube 12 described above. The spiral tube 12 is made of a precipitation hardening alloy material such as a beryllium copper alloy, and is made of a thin strip of uniform width wound spirally with a uniform diameter. The spiral tube 12 has a concave groove portion 1
After forming the recessed portion 1a, a solution treatment is performed with, for example, a cored metal inserted over the entire length to prevent twisting due to distortion during processing. After the strain is removed by this treatment, it is hardened by an age hardening treatment. In this way, the precipitation hardening type alloy material can be finally hardened by age hardening treatment, so a relatively soft material is used to form the concave groove portion 11.
The molding process of a can be easily performed.

When a beryllium copper alloy is used as the material, the solution treatment is performed by heating at 810° C. for 10 minutes or more and then rapidly cooling, and the age hardening treatment is performed at 315° C. for 2 hours or more, for example.

In addition, beryllium copper alloy has the property of blocking X-rays, so the optical fiber bundle inserted inside the
It can provide some protection against yellowing due to X-ray exposure. However, other than beryllium-copper alloy, any precipitation-hardening alloy material can be used as the material; for example, precipitation-hardening stainless steel alloy, duralumin alloy, etc. can also be used.

FIG. 4 shows a state in which the outer side of the spiral tube 12 is closely covered with a mesh tube 13. Although ordinary stainless steel wire or the like can be used as the material for the mesh tube 13, it is more preferable to use the same precipitation hardening alloy material as the spiral tube 12. In manufacturing, before forming the concave groove portion 11a in the helical tube 12, the outer side of the helical tube 12 is tightly coated with the reticular tube 13, and the helical tube 12 and the reticulated tube 13 are integrated.
It is preferable to form the groove portion 11b shown in the figure.

When the concave groove portion 11b is formed in this manner, the helical tube 12 is pressed by the mesh tube 13 and no noticeable twisting occurs, but the stress that tends to twist remains in the helical tube 12. Residual stress in the helical tube 12 is then removed by performing age hardening treatment. If the mesh tube 13 is made of the same precipitation hardening alloy material as the spiral tube 12, the mesh tube 13 will also be similar to the spiral tube 1.
2 and solution treatment at the same time, followed by age hardening.

FIG. 5 shows a plurality of spiral tubes 12 with different winding directions.
A and 12b are brought into close contact with each other to form a spiral tube, and the material and heat treatment etc.
It is the same as the one in the figure. In this way, the strength against twisting of the helical tube is improved by forming a plurality of helical tubes with different winding directions in close contact with each other. Therefore, the spiral tube can be doubled or tripled.
It may be configured to have more than one weight.

Returning to FIG. 1, the outer skin 14 covering the outside of the reticular tube 13 is made of, for example, a polyurethane resin-based synthetic resin. The outer skin 14 can be formed by applying molten resin to the outer surface of the reticular tube 13 by extrusion molding or the like. Alternatively, a tube-shaped outer skin may be brought into close contact with the outer surface of the reticular tube 13 by heat processing, vacuum suction, or the like.

In the thus formed flexible tube of the endoscope of this embodiment, as shown in FIGS. 1 and 2, a concave groove 11 is formed straight along the tube axis direction, and as shown in FIG. As shown in the figure, a forceps channel or other channel 20 can be accommodated in the groove 11.

Note that various conditions such as the temperature and timing of the heat treatment vary depending on the composition and dimensions of the material, and are not limited to the conditions of the above embodiments.

[Effects of the Invention] According to the flexible tube of the endoscope of the present invention, the helical tube is subjected to solution treatment, so that after forming the concave groove in the helical tube, distortions during processing are removed, and twists and steps are eliminated. It is possible to form a straight flexible tube without any cracks. Furthermore, since the spiral tube can be hardened and strengthened through the subsequent age hardening treatment, the groove can be easily formed using a material that is soft in hardness before the treatment. As a result, the channel etc. can be inserted into the concave groove, so the channel etc. can be placed along the flexible tube without causing any unnecessary pain to the patient. This has the effect that the built-in components inserted into the spiral tube will not be damaged by being hit by the spiral tube.

[Brief explanation of drawings]

Fig. 1 is a cross-sectional view of a flexible tube of an endoscope according to an embodiment of the present invention taken along a cross section perpendicular to the tube axis, and Fig. 2 is an external perspective view of the endoscope with the flexible tube attached. , 3rd
Figures 4 and 4 are perspective views of a spiral tube and a reticular tube forming the flexible tube, Figure 5 is a perspective view of a spiral tube formed by two types of spiral tubes with different winding directions, and Figure 6 is a concave groove. FIG. 3 is a cross-sectional view of a state in which a channel or the like is inserted. 10... Flexible tube, 11... Concave groove, 11a, 11b...
Recessed groove portion, 12... spiral tube, 13... reticular tube, 14... outer skin.

Claims (1)

[Scope of Claims] 1. A flexible tube for an endoscope, characterized in that it has a spiral tube in which a concave groove is formed along the tube axis direction and is subjected to solution treatment and then age hardening treatment. 2. The flexible tube for an endoscope according to claim 1, wherein the spiral tube is made of a beryllium steel alloy. 3. The flexible tube for an endoscope according to claim 1 or 2, wherein the screw tube is formed by closely adhering a plurality of spiral tubes wound in different directions. 4. The flexible tube of an endoscope according to claim 1, wherein the spiral tube is formed by closely covering the outer side of the spiral tube with a metal mesh tube.