JPS6311011B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improvement in a flexible tube for an endoscope, which is particularly suitable for small diameter tubes.

Generally, a flexible tube for an endoscope is used as an insertion section of an endoscope, and therefore is required to have various functions.
In other words, it not only has flexibility, but also watertightness that protects the built-in optical fiber bundle from moisture such as body fluids in the human body, and followability (especially followability in rotational direction),
Examples include cross-sectional shape retention to protect built-in items such as optical fiber bundles.

Therefore, the conventional flexible tube for an endoscope is constructed as shown in FIG. 1 in order to satisfy the various functions described above. That is, a spiral tube 1 made of a metal band 1a that imparts shape retention is inserted into the innermost side, and a reticular tube 2 that imparts followability in the rotational direction is inserted into the outer side of the helical tube 1, which is made of a metal band 1a that imparts shape retention, and a mantle tube 3 that has watertightness is further placed on the outside thereof.
It was externally packaged.

In this way, the spiral tube 1, the reticular tube 2 and the mantle tube 3
Because it has a triple-layer structure in which two layers are overlapped, there is a limit to how thin the overall wall thickness can be made, and the smaller the diameter, the significantly smaller the ratio of the inner diameter to the outer diameter than the larger diameter. , it becomes impossible to incorporate the required amount of optical fiber bundles 4, 4, etc. In addition, if the wall thickness of the mantle tube 3 is made too thin, wrinkles will easily form due to friction when it is inserted into a bent part or a human body, and the outer diameter will become thicker or the mantle tube 3 may tear at the wrinkled part. Problems that occur may occur. In addition, since there is a spiral tube 1 made of a metal band on the innermost side, the optical fiber bundles 4, 4 are formed at the edge of the metal band 1a.
It became necessary to interpose protective tubes 5, 5 to prevent the internal components from being damaged, and the space for installing the built-in items became smaller accordingly. Furthermore, as a manufacturing defect, in order to reduce shape retention and the wrinkles mentioned above,
It is necessary to bring the outer tube 3 into pressure contact with the spiral tube 1 and the mesh tube 2, but if the inner diameter of a small diameter tube is expanded by the same amount as a large diameter tube, the expansion rate will increase.
There were problems such as the mantle tube 3 bursting due to high pressure.

The present invention has been made focusing on the above circumstances,
The purpose of this is to be able to increase the effective inner diameter compared to the outer diameter with a thin wall without impairing various required functions, and to prevent damage to internal components.
Another object of the present invention is to provide a flexible tube for an endoscope that is easy to manufacture.

Hereinafter, one embodiment of the present invention will be described with reference to FIGS. 2 to 4.

Reference numeral 11 in FIG. 2 is a flexible tube for an endoscope, and as shown in FIG. Furthermore, the outer peripheral surface thereof is covered with a jacket tube 14 made of a heat-shrinkable flexible tube. That is, the endoscope flexible tube 11 is constructed by using the mesh tube 12 whose mesh is filled with elastic resin 13 as the inner layer and the outer tube 14 as the outer layer.

As the elastic resin 13, an elastic material such as silicone resin is used. The outer tube 14 is made of a heat-shrinkable resin such as polyurethane or Teflon, and due to its heat shrinkage, it bites into the mesh of the reticulated tube 12 and adheres tightly, as shown in FIG. Further, the inner surface of the mesh tube 12 is made of elastic resin 13 to be flat and smooth so that there are no irregularities due to the mesh. That is, at least the reticular tube 12
The elastic resin 13 is used to form a flat and smooth inner surface 15 so that the metal wires and the like that make up the knitting do not protrude from the inner surface alone.

In addition, if a material having particularly adhesive properties is used as the elastic resin 13, the mesh tube 12 and the elastic resin 13
and the outer tube 14 are adhered to each other and are strongly integrated.

Next, a method for manufacturing the flexible tube 11 for an endoscope will be described with reference to FIG. 4.

That is, after the reticular tube 12 is fitted onto the outer periphery of the core rod material 16 having an outer diameter that matches the desired inner diameter of the flexible tube 11 for an endoscope, and the mesh tube 12 is tightly attached to the outer periphery of the core rod material 16, a fluidized elastic resin before curing is applied. 13 is filled into the mesh of the reticular tube 12. Then, the unshrinked mantle tube 14 is inserted and fitted onto it. Thereafter, the mantle tube 14 is heated sequentially from one end to shrink. As a result, the mantle tube 14 gradually contracts in the direction of the arrow a, bites into the mesh of the reticular tube 12, and is firmly attached.
In addition, the elastic resin 1 removed by this biting
3 is pushed out to the unshrinked portion side. After shrinking and adhering in this manner, the elastic resin 13 is cured to complete the process.

As explained above, in the flexible tube for an endoscope of the present invention, the mesh of the reticular tube is filled with elastic resin, so that the reticular tube whose cross-sectional shape is easily deformed (easily crushed) can be kept in shape. Therefore, the spiral tube conventionally used to impart shape retention can be omitted, and as a result, the wall thickness of the flexible tube for an endoscope can be reduced. The number of built-in components can be increased to improve optical performance, and the outer diameter can be reduced to improve ease of insertion into the human body.

In addition, by omitting the spiral tube, the inner surface of the flexible tube for endoscopes can be formed smoothly, and the edge portion of the metal band constituting the spiral tube can damage built-in items such as optical fiber bundles. There is no fear. Moreover, unlike conventional optical fibers, the optical fiber bundle is not damaged, so there is no need to cover the optical fiber bundle with a protective tube, and the inner lumen of the flexible tube for an endoscope can be used more effectively. As a result, it is possible to achieve the same effect as described above, that is, increase the number of built-in parts to improve optical performance, and reduce the outer diameter to improve insertability into the human body.

Further, since the mantle tube is formed from a heat-shrinkable flexible tube and is shrunk, it bites into the mesh of the reticular tube and is integrally attached. Therefore, even if a thin-walled mantle tube is used, it is possible to prevent the mantle tube from becoming wrinkled due to the bending action or the frictional force applied to the outer surface. Furthermore, this effect allows the overall wall thickness to be made thinner, so it is possible to achieve the same effects as mentioned above, i.e., increase the number of built-in parts to improve optical performance, or reduce the outer diameter to improve ease of insertion into the human body. You can

In addition, as a manufacturing advantage, since a heat-shrinkable flexible tube is used as the flexible tube, the covering operation to achieve strong adhesion is extremely easy, and productivity can be improved. Furthermore, there is no need to forcibly expand the mantle tube during this covering operation, and problems such as rupture of the mantle tube due to such expansion can be eliminated.

[Brief explanation of the drawing]

FIG. 1 is a partially cut-away perspective view of a conventional flexible tube for an endoscope, and FIG. 2 is a partially cut-away perspective view of a flexible tube for an endoscope according to an embodiment of the present invention. FIG. 3 is a sectional view showing a part of the flexible tube for an endoscope, and FIG. 4 is a perspective view showing a method for manufacturing the flexible tube for an endoscope. 11... Flexible tube for endoscope, 12... Reticular tube, 13...
Elastic resin, 14... Mantle tube, 15... Inner surface.

Claims (1)

[Scope of Claims] 1. A reticular tube, an elastic resin that fills the mesh of the reticulated tube and flattens the inner surface of the reticulated tube;
A flexible tube for an endoscope, comprising a jacket tube made of a heat-shrinkable flexible tube that contracts and covers the outer circumferential surface of the mesh tube so as to bite into the mesh of the mesh tube. 2. In the flexible tube for an endoscope according to claim 1, the elastic resin has adhesive properties and is integrally bonded to the reticular tube and the outer tube. Flexible tube for endoscopy.