JPH11285468A - Manufacture of endoscope flexible tube - Google Patents

Abstract

PROBLEM TO BE SOLVED: To finish smoothly by a simple and reliable method without increasing the thickness of an outer sheath, without producing irregularities on the surface of the sheath, irrespective of a sheath covering method, thereby manufacturing a flexible tube that has uniform flexibility, a turning followability during insertion and that can resist twisting and surface creasing and improving the manipulability which an endoscope is required to have. SOLUTION: The manufacturing method is comprised of the first process in which a covering material is formed by covering a round rod 5 with a meshy tube 3 and the second process, where a sheath material 7 is formed by covering the outside of the covering material with a skin 4 together with the meshy tube 3 after the first process, the third process where the round rod 5 is removed from the outer clad material 7 formed in the second process and the fourth process where a spiral tube 2 is mounted to the inside of the sheath material 7 after the third process.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of manufacturing a flexible tube for an endoscope in which the outer periphery of a reticulated tube is covered with a sheath and a spiral tube is incorporated inside the reticulated tube.

[0002]

[Prior Art] Japanese Patent Publication No. 5-47810, Japanese Patent Publication No. 6-79591
As known in Japanese Patent Application Publication No. JP-A-63-24380 and Japanese Patent Publication No. Sho 63-24380, a flexible tube for an endoscope is formed by incorporating a spiral tube formed by spirally winding a strip into the outer shell material.

[0003] As a method of manufacturing this conventional endoscope flexible tube, a spiral tube formed by spirally winding a strip, and a tubular braid using a wire or a bundle of wires are used. The outer peripheral surface of a flexible tube material consisting of a mesh tube covering the outer periphery of the above is coated with an outer skin of a thermoplastic elastic body. There are the following five methods for coating the outer skin.

A. A method of coating a preformed thermoplastic elastic tube on the outer periphery of a flexible tube material. B. A method of tightly covering the outer skin by extruding a thermoplastic elastic body on a flexible tube material. C. After covering the tube of the thermoplastic elastic body formed in advance with the flexible tube material, the tube is heated to a temperature equal to or higher than the softening point of the tube while rotating about the axis as a rotation center, and the tube is integrated with the flexible tube material and covered. Method. D. A method in which an adhesive is applied to a flexible tube material, and a thermoplastic elastic body is tightly coated thereon by extrusion molding. E. FIG. A method of directly covering a flexible tube material with a previously melted thermoplastic elastic body.

[0005] The outer cover layer formed by each of the above methods is not limited to a single layer, but may be formed in multiple layers. Also,
In some cases, the above-described coating methods A to E are combined. After forming the outer skin by the above methods A to E or a combination of those methods, in order to smooth the unevenness generated on the surface of the outer skin, the outer skin is polished using a solvent or sandpaper, or the outer skin is heated using heat. The surface was melted and smoothed.

[0006]

(Defects of the prior art) A
The outer sheath coating formed by the method described above is connected and fixed between the flexible tube material and the thermoplastic elastic body only by the tightening force of the tube, so that when inserted into a body cavity, the flexible tube bends. Not only is it easy to cause wrinkles on the outer surface,
There is a drawback that it is weak against a compressive force when inserted into a body cavity. In addition, for the same reason, the outer peripheral portion is easily twisted due to poor rotation followability, and once twisting occurs, the outer peripheral portion of the outer skin is easily caught between the inner wall of the body cavity and wrinkles, causing pain to the patient at the time of insertion. There was a problem. In addition, if the tightening force of the tube is increased, the pattern of the spiral tube emerges on the surface of the outer skin,
In addition to the appearance of irregularities on the outer surface of the outer skin, which cause a drop in the product image, and in terms of functional performance, it causes pain to the patient at the time of insertion and hinders the smooth insertion operation. Because of the uneven thickness of the slab, there has been a problem that the flexibility that should be uniform during bending is adversely affected. Also, if the outer skin is made thicker to reduce the appearance irregularities, the outer diameter of the flexible tube itself becomes not only thicker but also very hard, so that the flexible tube does not bend smoothly at the time of insertion, which is painful for the patient. This causes problems such as hindering a smooth insertion operation. In addition, in order to fix the appearance irregularities in terms of manufacturing cost, a surface repair process was provided in the subsequent process and rework was performed,
This led to an increase in cost and further complicated the line form.

The outer cover formed by the methods B to E uses a means for melting and adhering a thermoplastic elastic material to a flexible tube material during processing. When molded by this method, the thermoplastic elastic material can be used. Infiltration into the gap between the spiral tubes of the flexible tube material, and in some cases, the permeated thermoplastic elastic body protrudes to the inner surface of the flexible tube, and causes unevenness between the permeated portion and the non-permeated portion. . As a result, in terms of functional performance, irregularities appear on the outer surface of the outer skin, reducing the product image,
This causes pains to the patient at the time of insertion and causes problems such as hindering a smooth insertion operation. In addition, the thickness of the outer skin is unbalanced with respect to the center axis, which causes a problem that the flexibility that should be uniform during bending is adversely affected. Also, if the outer skin is made thicker to reduce the appearance irregularities, the outer diameter of the flexible tube itself becomes not only thick but also very hard, so that smooth bending is not performed at the time of insertion, and the This has caused problems such as pain and hindrance to a smooth insertion operation. In terms of manufacturing costs, a surface repair process was provided in the subsequent process to correct the appearance irregularities, and this was reworked, which led to an increase in cost and further complicated the line form.

(Object of the Invention) The present invention has a spiral tube, a reticulated tube, and a thermoplastic elastic body in the main structure, as in the conventional flexible tube, and the inner cover is melted and adhered to the reticulated tube. In the method of manufacturing a flexible tube for endoscopes, regardless of the method of covering the thermoplastic elastic body, it is easy and reliable, without increasing the thickness of the skin and without causing irregularities on the surface of the skin, Finished, it also makes the flexibility uniform, makes it easy to follow the torsion during insertion, and makes it possible to manufacture a flexible tube that is less likely to twist or surface wrinkle. They are also trying to improve.

[0009]

According to the present invention, there is provided a first step of forming a covering material by covering a core material with a braided tube, and after the first step, an outer coat is provided on the outside of the covering material. A second step of forming an outer shell material together with the mesh tube by coating the core material, a third step of removing the core material from the outer shell material formed by the second step, and after the third step,
And a fourth step of attaching a helical tube to the inside of the outer shell material. When coating the outer surface of the mesh tube with the outer skin, the core material is attached to the inner surface of the mesh tube instead of the spiral tube, so the material of the outer skin only penetrates to the core material surface regardless of the coating method of the outer skin. Finished with a smooth and clean outer appearance. Also,
Finally, by incorporating the spiral tube inside the outer shell material, the outer surface of the flexible tube does not become uneven.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Each embodiment of the present invention will be described with reference to FIGS. FIG. 1 is a partial cross-sectional view of a flexible tube in an insertion portion of an endoscope used for medical use or the like. FIG. 2 is an explanatory view of a state in which the mesh tube is coated on the outer periphery of a perfect circular rod used in the method of manufacturing a flexible tube according to the present embodiment. FIG. 3 is an explanatory diagram of a state in which a perfect round bar is pulled out from the outer shell material of the flexible tube in the method of manufacturing a flexible tube according to the present embodiment.

[First Embodiment] (Purpose) The present invention relates to a method of manufacturing a flexible tube for an endoscope having a spiral tube, a mesh tube, and an outer shell of a thermoplastic elastic body as basic constituent members. It is an object of the present invention to be able to easily and reliably finish a surface of an outer skin in a smooth state, without generating irregularities, regardless of a method of covering the outer skin of a body.

(Structure) A flexible tube 1 shown in FIG. 1 is, for example, a spiral tube 2 formed by spirally winding a metal strip, a mesh tube 3 covering the outer periphery thereof, and an outer periphery of the mesh tube 3. The outer skin 4 of the thermoplastic elastic body coated on the surface is configured as a basic constituent member.

A perfect round bar 5 as a core shown in FIG. 2 is made of a releasable material such as Teflon or polyethylene, or a metal such as SUS or copper whose surface has been subjected to a release treatment. Are formed on a smooth surface.

When the flexible tube 1 is manufactured, first, as shown in FIG. 2, the outer periphery of a perfect circular rod 5 is covered with a braided tube 3 braided by using a wire or a wire bundle. 3, a coating material 6 is formed. Next, an adhesive is first applied to the surface of the reticulated tube 3 and the outer cover 4 of a thermoplastic elastic body such as polyurethane, soft vinyl chloride, or polyester is extruded on the surface of the reticulated tube 3 to form the reticulated tube 3 and the outer cover. 4
To form an integrated outer shell material 7. As the adhesive at this time, various general adhesives can be used. For example, a silane-based or titanate-based primer may be used.

Thereafter, as shown in FIG. 3, only the perfect round bar 5 is removed from the integrated outer shell material 7. Next, the skin material 7
The flexible tube 1 is completed by inserting and assembling a spiral tube 2 formed by spirally winding a strip into the inside.

In order to maximize the inner diameter of the spiral tube 2 after the spiral tube 2 has been assembled, "the outer diameter of the spiral tube 2 before the assembly ≧
It is desirable that the relationship be "the inner diameter of the flexible tube sheath material 7". (Effect) According to the present embodiment, when extruding the outer cover 4, the spiral tube 2 is not assembled in the coating material 6, but a round rod 5 having a smooth outer surface is assembled instead. For this reason, at the time of extrusion molding, the thermoplastic elastic body can be dissolved into the mesh tube 3 more than before, and a stronger close-integration treatment can be performed. Nevertheless, the outer skin 4 can be finished smoothly and beautifully. In addition, the surface modification work after the extrusion molding is not required.

[Second Embodiment] (Purpose) The present invention relates to a method of manufacturing a flexible tube for an endoscope having a spiral tube, a mesh tube, and an outer shell of a thermoplastic elastic body as basic constituent members. It is an object of the present invention to provide a method for producing a flexible tube which can be finished in a smooth state without any irregularities on the surface of the outer skin by an easy and reliable method regardless of the method of coating the outer skin of the body.

(Structure) This embodiment is a method for manufacturing a flexible tube 1 similar to that shown in FIG. 1 described above.

When the flexible tube 1 is manufactured, first, as shown in FIG. 2, the outer periphery of a perfect circular rod 5 is covered with a braided tubular tube 3 using a wire or a wire bundle, and a coating material is formed. 6 is formed.
Next, on the outer peripheral surface of the reticulated tube 3, an outer cover 4 made of a thermoplastic elastic material such as polyurethane, soft vinyl chloride, or polyester is extruded to form a cover material 7 composed of the reticulated tube 3 and the cover 4.

Then, a perfect round bar 5 coated with the outer shell material 7
Is heated to a temperature higher than the softening point of the outer shell 4 while rotating the outer shell 4 about its axis, and the outer shell 4 is placed in the eyes of the tissue of the mesh tube 3 constituting the outer shell material 7.
Is further adhered or melted therein to promote close contact integration. When the outer cover 4 is composed of a plurality of thermoplastic elastic bodies, the highest softening point is used as a reference.

Thereafter, as shown in FIG. 3, only the perfect round bar 5 is removed from the outer shell material 7, and the spiral tube 2 formed by spirally winding a strip into the remaining outer shell material 7 is inserted and assembled. The flexible tube 1 is completed.

The flexible tube 1 after the spiral tube 2 is assembled
In order to maximize the inner diameter of the spiral tube 2, it is preferable that the relationship “the outer diameter of the spiral tube 2 before assembly ≧ the inner diameter of the flexible tube outer shell material 7” be satisfied.

(Effect) According to the present embodiment, the spiral tube 2 cannot be assembled in the coating material 6 until the process of extruding the outer cover 4 and thermally welding the outer cover 4 to the mesh tube 3. Instead, a perfect round bar 5 having a smooth surface is assembled. For this reason, in two steps of extrusion molding and heat welding, the thermoplastic elastic body can be melted into the reticulated tube 3 more than ever before, and the integral treatment for more tightly adhering can be sufficiently performed. In addition, the outer skin 4 can be finished smoothly and beautifully. In addition, the surface modification work after the extrusion molding is not required.

[Third Embodiment] (Purpose) The present invention relates to a method of manufacturing a flexible tube for an endoscope having a spiral tube, a mesh tube, and an outer shell of a thermoplastic elastic body as a basic constituent member. It is an object of the present invention to provide a method for manufacturing a flexible tube which can be finished in a smooth state without any irregularities on the surface of the outer shell by an easy and reliable method regardless of the coating method.

(Construction) This embodiment is a method for manufacturing a flexible tube 1 similar to that shown in FIG. 1 described above.

When the flexible tube 1 is manufactured, first, as shown in FIG. 2, the outer periphery of a perfect circular rod 5 is covered with a braided tubular tube 3 using a wire or a bundle of wires, and the coating material is coated. 6 is formed.
Next, the outer surface of the mesh tube 3 is covered with a sheath 4 previously formed into a tubular shape with a thermoplastic elastic material such as polyurethane, soft vinyl chloride, or polyester.

Then, while rotating them around the axis of the perfect circular rod 5 as the center of rotation, the coating material 6 is heated to a temperature higher than the softening point of the outer cover 4 to form the structure of the mesh tube 3 constituting the coating material 6. The thermoplastic material of the outer skin 4 is further adhered to the eyes, or is melted in the inside so as to be closely integrated. When the outer cover 4 is composed of a plurality of thermoplastic elastic bodies, the highest softening point is used as a reference.

Thereafter, as shown in FIG. 3, only the perfect round bar 5 is removed therefrom, and the spiral tube 2 formed by spirally winding the strip is inserted into the remaining outer shell material 7 and assembled.
The flexible tube 1 is completed. In addition, from the viewpoint of ensuring the maximum inner diameter after the spiral tube 2 is assembled, it is desirable that the relationship “the outer diameter of the spiral tube 2 before the assembly ≧ the inner diameter of the flexible tube outer shell material 7” is satisfied.

(Effect) According to the present embodiment, when the outer cover 4 is heat-welded to the mesh tube 3, the spiral tube 2 is not assembled in the coating material 6, and Instead, a round rod 5 with a smooth surface is assembled. Therefore, at the time of heat welding, the thermoplastic elastic body is melted into the mesh tube more than ever, The appearance of the outer cover 4 can be finished smoothly and neatly while trying. In addition, the work for repairing the surface after the heat welding process is not required.

[Fourth Embodiment] (Purpose) This embodiment is directed to a method of manufacturing a flexible tube for an endoscope having a spiral tube, a mesh tube, and an outer shell of a thermoplastic elastic body as basic constituent members. It is an object of the present invention to provide a flexible tube that can be finished in a smooth state without any irregularities on the surface of the skin by an easy and reliable method regardless of the method of coating the skin.

(Structure) This embodiment is a method for manufacturing a flexible tube 1 similar to that shown in FIG.

When the flexible tube 1 is manufactured, first, as shown in FIG. 2, a mesh tube 3 braided into a tubular shape using a wire or a bundle of wires around the round bar 5 having a smooth outer surface. Coating is performed to form a coating material 6.

Then, an adhesive is first applied to the surface of the coating material 6, and the outer surface of a thermoplastic elastic material such as polyurethane, soft vinyl chloride, polyester, or the like is coated by extrusion molding. At this time, a general adhesive can be used, but a silane-based or titanate-based primer may be used.

Then, while rotating the perfect circular rod 5 about its axis as a center of rotation, it is heated to a temperature higher than the softening point of the outer cover 4, and the coating material 6 is heated. The resin portion of No. 4 is further adhered or melted into the resin portion to be tightly integrated. When the outer cover 4 is composed of a plurality of thermoplastic elastic bodies, the highest softening point is used as a reference.

Thereafter, as shown in FIG. 3, the spiral tube 2 formed by spirally winding the strip is inserted into the outer shell material 7 which is obtained by removing only the perfect rod 5 therefrom, and assembled.
Complete.

From the viewpoint of ensuring the maximum inner diameter of the spiral tube 2 after the assembly, the following expression is necessary: “the outer diameter of the spiral tube 2 before the assembly ≧
It is desirable that the relationship be "the inner diameter of the flexible tube sheath material 7". (Effects) According to the present embodiment, the helical tube 2 is placed in the coating material 6 until the outer cover 4 is extruded and heat-welded to the mesh tube 3.
Is not assembled, but instead a round rod 5 with a smooth surface is assembled. In two steps of extrusion molding and heat welding, the thermoplastic elastomer is melted into the mesh tube more than ever. In addition, the outer skin 4 can be smoothly and finely finished while further performing a close integration process. Since an adhesive is also applied to the surface of the reticulated tube before coating the outer cover, the outer cover and the reticulated tube are further strengthened. In addition, the surface modification work after the extrusion molding is not required.

The present invention is not limited to the embodiment described above. In addition, at least the items listed below and any combination thereof can be obtained. <Supplementary notes> A first step of forming a coating material by coating the core material with the mesh tube; and a second step of coating the outer skin of the coating material to form an outer shell material together with the mesh tube after the first step. A third step of removing the core material from the outer shell material formed by the second step, and a fourth step of attaching a spiral tube inside the outer shell material after the third step. A method for manufacturing a flexible tube for an endoscope, comprising: 2. The outer surface of the braided tube which is braided using strands and strands and fitted on the outer periphery of the round bar is coated with the outer skin of a thermoplastic elastic body. A method for manufacturing a flexible tube for an endoscope, wherein a spiral tube formed by spirally winding a strip into the inside is inserted and assembled. 3. 3. The method for manufacturing an endoscope flexible tube according to claim 2, wherein an outer skin is coated after an adhesive or a primer is previously applied to the surface of the coating material. 4. 3. The method according to claim 2, wherein the outer shell material is heated at a temperature higher than the softening point of the outer shell before inserting the spiral tube.

[0038]

According to the present invention, the conventional structure can be manufactured by a simple manufacturing method, and the appearance of the outer skin is smooth without the need for a surface finishing step, and the surface has no wrinkles. Manufacture of an endoscope flexible tube having uniform flexibility, excellent torsion followability, less likely to twist, and having improved flexibility and durability in insertion into a body cavity. Can be.

[Brief description of the drawings]

FIG. 1 is a partial cross-sectional view of a flexible tube in an insertion portion of an endoscope used for medical use or the like.

FIG. 2 is an explanatory view showing a state in which an outer periphery of a perfect circular rod used in the method for manufacturing a flexible tube according to the present embodiment is covered with the mesh tube.

FIG. 3 is an explanatory view showing a state in which a perfect round bar is pulled out from a flexible tube outer shell material in the method of manufacturing a flexible tube according to the present embodiment.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Flexible tube, 2 ... Spiral tube, 3 ... Reticulated tube, 4 ... Skin, 5 ...
Round bar, 6: coating material, 7: flexible tube sheath material.

Claims (1)

[Claims] 1. A first step of forming a coating material by coating a core material with a mesh tube, and, after the first step, coating an outer shell on the outside of the coating material to form a shell material together with the mesh tube. A second step of forming; a third step of removing the core material from the outer cover material formed by the second step;
And a fourth step of attaching a spiral tube inside the outer shell material after the step (b).