JPH0226489B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a flexible tube for an endoscope used as an insertion section.

In general, flexible tubes for endoscopes are flexible, watertight to protect the built-in optical fiber bundle from moisture such as bodily fluids, and have a distal end that can be operated outside the body. Important performance requirements include followability (particularly followability in the rotational direction) and cross-sectional shape retention to protect internal components such as optical fiber bundles.

Therefore, in order to satisfy such performance, conventional flexible tubes have a spiral tube made of a metal band that provides shape retention on the innermost side, and a mesh tube that provides followability in the rotational direction on the outer side. Furthermore, the outside thereof is covered with a watertight outer skin. However, with such a three-layer flexible tube, there is a limit to how thin the overall wall thickness can be made, and the smaller the tube, the lower the ratio of the inner diameter to the outer diameter compared to the larger tube. This makes it extremely small, making it impossible to incorporate the necessary amount of optical fiber bundles, etc. Therefore, it was unsuitable for use in endoscopes for diagnosing the bronchi and ureters, which require smaller diameters.

Therefore, in order to reduce the diameter of the flexible tube, as shown in Japanese Patent Application No. 133472/1987, although unpublished, the mesh of the mesh tube was filled with elastic resin instead of using a spiral tube.
A flexible tube has been proposed in which this reticular tube is covered with a synthetic resin outer skin. According to such a flexible tube, the overall wall thickness can be reduced and the ratio of the inner diameter to the outer diameter can be made relatively large. The diameter can be reduced to improve ease of insertion into the human body.

By the way, the flexible tube has a distal end frame having an objective lens etc. connected to its distal end, and a proximal end frame provided on the operating section connected to its proximal end. However, the flexible tube described above has an outer skin made of synthetic resin and an inner circumferential surface made of elastic resin filled into a mesh tube, and since both the outside and the inside are made of synthetic resin, the adhesion with adhesive is extremely poor. low. This tendency becomes particularly noticeable when silicone resin is used as the elastic resin. Therefore, the state of connection between the distal end frame and the proximal end frame is not reliable, leading to leakage of liquid into the flexible tube, and the fear that the distal end frame and the proximal end frame may come off during use. Even if the distal end frame and the proximal end frame were adhered to both ends of the flexible tube, the synthetic resin outer skin and the elastic resin filled in the reticulated tube would not have sufficient mechanical strength. Therefore, there was a strength problem in that both ends of the flexible tube were prone to premature breakage due to repeated bending stress applied to the connecting portion between the distal end frame and the proximal end frame of the flexible tube.

This invention was made based on the above-mentioned circumstances, and its purpose is to fill both ends of a mesh tube with metal to improve the adhesion and mechanical strength of both ends. An object of the present invention is to provide a flexible tube for an endoscope.

An embodiment of the present invention will be described below with reference to the drawings. 1 in FIG. 1 is an endoscope. This endoscope 1 includes an operating section 3 provided with an eyepiece section 2, an insertion section 4 whose proximal end is connected to this operating section 3, and an operating section 3.
A universal cord 6 is provided with a connector 5 connected at one end to a light source device (not shown) at the other end. The insertion section 4 has a second
As shown in the figure and FIG. 3, it is composed of a flexible tube 7. The flexible tube 7 consists of a reticular tube 8 and an outer skin 9 made of a synthetic resin such as polyurethane or Teflon, which covers the outer peripheral surface of the reticular tube 8.
The mesh tube 8 is made of elastic resin such as silicone resin, for example, in the mesh of the portion excluding both ends in the axial direction.
0, and the meshes at both ends are filled and solidified with molten metal such as solder, thereby forming metal layers 11, 11.

A tip frame 12 is fitted to the tip of the flexible tube 7,
The outer circumferential surface thereof and the inner circumferential surface of a metal layer 11 formed at the tip of the reticular tube 8 are bonded. An inner short tube 13 and an outer short tube 14 are concentrically connected to the tip frame 12. The inner short tube 13 holds an objective lens 15 and a distal end portion of an irradiation optical fiber bundle 16 with the distal end surface facing the objective lens 15. Further, the outer short tube 14 holds a distal end portion of an optical fiber bundle 17 for observation. The rear end of the illumination optical fiber bundle 16 is passed through the operating section 3 and passed through a universal cord 6, which is connected to a connector 5 provided at the end thereof. The rear end of the observation optical fiber bundle 17 is guided to the operating section 3, where it is optically connected to the eyepiece section 2.

Further, a base end frame 18 provided in the operating section 3 is connected to the rear end of the flexible tube 7. That is, at the rear end of the flexible tube 7, a part of the outer skin 9 covering the metal layer 11 formed on the mesh tube 8 is removed, and the exposed metal layer 11 is inserted into the attachment hole of the proximal frame 18. 19, and the outer circumferential surface of the metal layer 11 and the inner circumferential surface of the attachment hole 19 are bonded together.

The outer circumferential surface of the proximal end of the flexible tube 7 is held by an anti-bending member 2 made of an elastic material such as rubber, whose one end is engaged with an engaging portion 20 formed on the proximal frame 18.
Covered by 1.

According to the flexible tube 7 configured in this way, the flexible tube 7 is adhesively fixed to the distal end frame 12 and the proximal end frame 18 by the metal layer 11 formed on the mesh tube 8 of the flexible tube 7, 11. metal layer 11,1
1 has better adhesion to other members than synthetic resin, so the upper distal end frame 12 and the proximal end frame 18 can be reliably adhesively fixed to both ends of the flexible tube 7. Furthermore, if the distal end frame 12 and the proximal end frame 18 are made of metal, they can be adhesively fixed to the metal layers 11, 11 of the flexible tube 7 by welding. can be taken as a thing.
Furthermore, since the mechanical strength of both ends of the flexible tube 7 is improved by the metal layers 11, 11, the durability against bending stress repeatedly applied to both ends is improved.

As described above, this invention fills the mesh-like part of a metal mesh tube excluding both ends with an elastic resin,
A flexible tube was constructed by filling the meshes at both ends with metal and covering the outer peripheral surface of the mesh tube with a synthetic resin outer skin. Therefore, when adhering members such as the distal end frame and the proximal end frame to both ends of the flexible tube, it is possible to do so through the above-mentioned metals, which have superior adhesive properties compared to synthetic resins, so that the adhesion can be performed reliably. be able to. Furthermore, since both ends of the flexible tube have higher mechanical strength than the metal filled therein, they are less likely to break even if bending stress is repeatedly applied to the ends.

[Brief explanation of drawings]

The drawings show an embodiment of the present invention; FIG. 1 is a perspective view of the entire endoscope, FIG. 2 is a sectional view of the distal end of the flexible tube, and FIG. 3 is a sectional view of the proximal end. 8... Reticular tube, 9... Outer skin, 10... Elastic resin, 11... Metal layer.

Claims (1)

[Claims] 1. A metal mesh tube, an elastic resin filled in the mesh of the mesh except for both ends of the mesh tube, a metal filled in the mesh of both ends of the mesh tube, and covering the outer peripheral surface of the mesh tube. A flexible tube for endoscopes consisting of a synthetic resin outer skin.