JP3548249B2 - Endoscope flexible tube - Google Patents

Description

[0001]
[Industrial applications]
BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a flexible tube of an endoscope formed by covering an outer periphery of a spiral tube with a mesh tube and further covering the outer periphery of the mesh tube with an outer skin.
[0002]
[Prior art]
In general, a flexible tube of an endoscope is formed by coating a braided tube formed by braiding a thin metal wire on the outer periphery of a spiral tube, and further forming a flexible thermoplastic synthetic resin layer on the outer periphery of the braided tube. It is formed by covering an outer tube.
[0003]
And, in many cases, the adhesion between the reticulated tube and the outer cover is not sufficient, so the outer cover tube is heated to a melting temperature or higher to be welded to the reticulated tube. Further, in order to improve the adhesion between the reticulated tube and the outer tube, there is an example in which an adhesive is applied to the reticulated tube and then the molten outer tube is covered (Japanese Patent Publication No. 3-29406).
[0004]
[Problems to be solved by the invention]
Melting of the outer tube is performed in a process that sets the heating temperature and heating time.However, because the melting temperature varies depending on the tube production lot, the outer tube is not sufficiently welded to the mesh tube in the same manufacturing process. May occur.
[0005]
In addition, in the case of a flexible tube or the like in which a plurality of types of outer tubes having different hardness are coated at different positions in order to change the flexibility in a plurality of stages, the melting temperature of each tube is different, so that the tube is well welded to the mesh tube. There is a case where a portion to be welded and a portion which does not weld well are formed.
[0006]
A flexible tube in which the sheath tube is not sufficiently welded to the mesh tube is used and repeatedly bent, and the sheath tube peels off from the mesh tube in a relatively short period of time and buckles due to wrinkling. It often happens.
[0007]
When the adhesive is applied to the surface of the reticulated tube in advance, the durability against peeling is improved to some extent, but the welding of the outer tube to the reticulated tube is still inadequate. Just being late is not a fundamental solution.
[0008]
Therefore, an object of the present invention is to provide a flexible tube of an endoscope that can reliably and easily weld an outer skin layer to a mesh tube and has excellent durability against repeated bending and the like. And
[0009]
[Means for Solving the Problems]
In order to achieve the above object, the flexible tube of the endoscope according to the present invention is configured such that a braided tube formed by braiding a thin metal wire is coated on the outer periphery of the spiral tube, and the outer periphery of the braided tube is further flexible. In a flexible tube of an endoscope formed by coating an outer skin made of a thermoplastic synthetic resin layer with a synthetic resin, the same kind of synthetic resin as the outer skin is dissolved in a solvent and applied to the reticulated tube. It is characterized in that it is heated above the melting temperature of the synthetic resin and is melt-integrated with the mesh tube, and is covered with the above-mentioned outer skin heated above the melting temperature.
[0010]
The synthetic resin applied to the mesh tube may have different flexibility in the length direction of the flexible tube, and between the synthetic resin applied to the mesh tube and the mesh tube, An adhesive may be applied.
[0011]
【Example】
Embodiments will be described with reference to the drawings.
FIG. 2 shows a flexible tube 1 used for an insertion portion of an endoscope. However, the present invention may be applied to a light guide flexible tube or the like for connecting the light guide to the light source device.
[0012]
The innermost layer of the flexible tube 1 is a double spiral tube 2 or 3 in which a metal band such as stainless steel or phosphor bronze is spirally wound with a constant diameter. The winding directions of the inner spiral tube 2 and the outer spiral tube 3 are reversed, and the spiral tubes 2 and 3 are in close contact with each other.
[0013]
The outer circumference of the spiral tubes 2 and 3 is covered with a mesh tube 4. The braided tube 4 is formed by braiding a plurality of thin metal wires such as stainless steel wires in a bundled state, and is formed into a tubular shape as a whole. The parts are soldered and fixed to the spiral tubes 2 and 3.
[0014]
An outer skin 5 made of a flexible thermoplastic synthetic resin layer is coated on the outer periphery of the mesh tube 4. As the thermoplastic resin, polyurethane, polyethylene, soft vinyl chloride and the like can be used.
[0015]
The outer skin 5 is not simply covered on the outer periphery of the reticulated tube 4, but as shown in an enlarged view in FIG. An outer skin 5 is applied to the outer surface of the tube and is heated from above the melting temperature.
[0016]
By applying the thermoplastic resin 6 dissolved in the solvent to the reticulated tube 4 in such a manner, the reticulated tube 4 is in a state of being well wetted by the thermoplastic resin 6. Is welded to the braided tube 4 in a very high bonding state.
[0017]
Then, by heating the outer skin 5 to a temperature higher than the melting temperature, the outer skin 5 is fused with and integrated with the thermoplastic resin 6 made of the same kind of material. As a result, the outer skin 5 (and 6) is And a very well welded condition is obtained.
[0018]
As shown in FIG. 3, if different flexible thermoplastic resins 6a, 6b, 6c are applied in the length direction of the flexible tube 1, the endoscope in which the flexibility is changed in the middle. A flexible tube for the mirror can be easily made.
[0019]
4 to 12 show steps of manufacturing the flexible tube of the endoscope of the present invention in order, and a case where a polyurethane resin is used as the outer cover 5 and the thermoplastic resin 6 will be described as an example.
[0020]
First, as shown in FIG. 4, the core metal 10 is covered with the spiral tubes 2, 3 and the mesh tube 4, and the spiral tubes 2, 3 and the mesh tube 4 are soldered and fixed at both ends. The core 10 is pulled out as shown, and the bases 8, 9 are attached to both ends as shown in FIG.
[0021]
Next, as shown in FIG. 7, a thermoplastic resin 6 (polyurethane resin) dissolved with a solvent is uniformly sprayed and applied to the entire outer periphery of the mesh tube 4 through a core bar 11 longer than before. As a solvent for dissolving the polyurethane resin, tetrahydrofuran, dimethylformamide, dimethylsulfoxide, dioxane, M-cresol, cyclohexane and the like can be used.
[0022]
It is sufficient that the spray amount adheres to the surface of the mesh tube 4 by about several μm. If it is applied too much, the reticulated tube 4 is joined to the spiral tube 3 and the natural bending of the flexible tube 1 cannot be obtained.
[0023]
By this step, the reticulated tube 4 is in a state of being well-wetted by the thermoplastic resin 6, so that the thermoplastic resin 6 is welded to the reticulated tube 4 in a very high bonding state.
[0024]
Before the thermoplastic resin 6 is sprayed, a thin adhesive may be applied to the surface of the mesh tube 4. Thereby, the bonding force between the mesh tube 4 and the thermoplastic resin 6 is further increased. As the adhesive, for example, an epoxy resin, a phenol resin, a polyvinyl alcohol, a butyral resin, or the like can be used.
[0025]
Next, as shown in FIG. 8, after natural drying at room temperature for 1 hour to evaporate the solvent, for example, it is placed in a heating furnace 20 as shown in FIG. Heat for about 1 minute to 1 hour to melt the thermoplastic resin.
[0026]
In the heating furnace 20, the heating is performed uniformly by rotating the cored bar 11 as a center. By heating the thermoplastic resin 6 to a temperature equal to or higher than the softening point in the heating and melting step of FIG. 9, the bonding between the mesh tube 4 and the thermoplastic resin 6 can be further improved.
[0027]
Next, the thermoplastic resin 6 applied to the braided tube 4 is cooled, and as shown in FIG. 10, the polyurethane resin outer tube 5 is covered while expanding with compressed air or the like, and thereafter, as shown in FIG. Then, it is placed in a heating furnace 20 and heated to a temperature equal to or higher than the melting temperature of the outer skin 5 and the thermoplastic resin 6 which are both polyurethane resins. The heating is, for example, at 200 ° C. to 220 ° C. for 10 minutes to 1 hour.
[0028]
By dissolving the outer shell 5 and the thermoplastic resin 6 in this manner, the outer shell 5 is fused and integrated with the thermoplastic resin 6 made of the same material as the outer shell 5, and as a result, the outer shell 5 (and 6) is reticulated. 4 is obtained in a very well welded state. Finally, as shown in FIG. 12, the flexible tube 1 is taken out of the heating furnace 20, and the core 11 is pulled out to complete the process.
[0029]
The present invention is not limited to the above embodiment. For example, the resin melted by an extruder may be directly coated around the thermoplastic resin 6 without forming the outer skin 5 from a tube.
[0030]
【The invention's effect】
According to the present invention, a thermoplastic synthetic resin of the same kind as the outer shell is dissolved in a solvent and applied to a mesh tube, and then fused and integrated into the mesh tube by heating, so that the mesh tube is well wetted by the synthetic resin. In a state, both are welded in a very high bonding state. Then, since the outer skin heated above the melting temperature is coated thereon, the outer skin is integrated with a synthetic resin made of the same kind of material. As a result, it is possible to obtain a state in which the outer skin is very well welded to the braided tube, and it is possible to easily form a flexible tube having excellent durability without wrinkling due to repeated bending or the like.
[0031]
In addition, if the synthetic resin applied to the mesh tube has different flexibility in the length direction of the flexible tube, the flexible tube whose flexibility changes in the middle can be easily formed. If an adhesive is applied between the mesh tube and the synthetic resin, the bonding state between the mesh tube and the synthetic resin can be further enhanced.
[Brief description of the drawings]
FIG. 1 is a partially enlarged side sectional view of a flexible tube of an endoscope according to an embodiment.
FIG. 2 is a side sectional half view of a flexible tube of the endoscope according to the embodiment.
FIG. 3 is an explanatory diagram in a case where the flexibility of the flexible tube of the endoscope of the embodiment is changed in the middle.
FIG. 4 is a manufacturing process diagram of the flexible tube of the endoscope of the embodiment.
FIG. 5 is a manufacturing process diagram of the flexible tube of the endoscope of the embodiment.
FIG. 6 is a manufacturing process diagram of the flexible tube of the endoscope according to the embodiment.
FIG. 7 is a manufacturing process diagram of the flexible tube of the endoscope of the embodiment.
FIG. 8 is a manufacturing process diagram of the flexible tube of the endoscope of the embodiment.
FIG. 9 is a manufacturing process diagram of the flexible tube of the endoscope of the embodiment.
FIG. 10 is a manufacturing process diagram of the flexible tube of the endoscope of the embodiment.
FIG. 11 is a manufacturing process diagram of the flexible tube of the endoscope according to the embodiment.
FIG. 12 is a manufacturing process diagram of the flexible tube of the endoscope according to the embodiment.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Flexible tube 2, 3 Spiral tube 4 Reticulated tube 5 Skin 6 Thermoplastic synthetic resin

Claims (3)

An endoscope in which a mesh tube formed by braiding a thin metal wire is covered on the outer periphery of the spiral tube, and the outer periphery of the mesh tube is further covered with an outer skin made of a flexible thermoplastic synthetic resin layer. In the flexible tube of the mirror,
Synthetic resin of the same kind as the outer cover is dissolved in a solvent and applied to the mesh tube, and then heated to a melting temperature or higher of the synthetic resin and melt-integrated into the mesh tube, and a melting temperature of not less than the above. A flexible tube for an endoscope, wherein said flexible tube is formed by coating said heated outer skin. The flexible tube of an endoscope according to claim 1, wherein the synthetic resin applied to the mesh tube has different flexibility in a length direction of the flexible tube. 3. The flexible tube for an endoscope according to claim 1, wherein an adhesive is applied between the synthetic resin applied to the mesh tube and the mesh tube.

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