JP3385044B2 - Method for manufacturing flexible tube of endoscope - Google Patents

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.

[0002]

2. Description of the Related Art A flexible tube for an endoscope is generally formed by winding a metal band in a spiral shape and winding the spiral tube to the same diameter. It is configured by covering. Polyurethane-based and vinyl chloride-based plastic materials are generally used as the skin material.

As a method for assembling the outer cover, an outer cover formed in advance into a tubular shape by extrusion molding is covered on a mesh tube covered with a spiral tube and adhered to the mesh tube with an adhesive or heat welding, or coated on the spiral tube. There are various methods such as forming an outer cover on the formed mesh tube by using an extrusion molding machine and applying a material liquefied at room temperature to the mesh tube covered with the spiral tube and curing the material.

Further, the flexible tube of such an endoscope is formed so that the distal end side is made soft and the proximal side is made hard by changing the flexibility in the middle to improve the insertability into the body cavity. It is often done.

[0005]

It is desirable that the flexible tube of the endoscope be formed as thin as possible in order to reduce the pain to the patient.

However, in the case of forming a tube by extrusion molding, in the case of a flexible tube having a diameter of about 10 mm, the wall thickness needs to be 0.5 mm or more, and depending on the material, the wall thickness needs to be 1 mm or more. Will end up.

Even when the extruding machine is used to directly extrude the outer shell into the reticulated tube, it is difficult to successfully extrude the outer shell unless the thickness is equal to or greater than that. Also,
Expensive equipment is required to use the extruder,
There are also many material losses during molding.

In the case of the method of liquefying the material and applying it to the reticulated tube, it is necessary to perform the application work many times because the thickness of the film can only be about 0.1 mm by one application, and it is necessary to apply the solvent. It takes time to dry and remove, and bubbles are often generated at that time, so that the quality is not stable and the production efficiency is poor.

In the case of changing the flexibility of the flexible tube on the way, in the case of the tube covering method, the flexibility changes extremely at the connecting portion of the tubes having different hardness, so that the softer one can be used. The flexible tube has a drawback that it is easily bent and damaged in the vicinity of the joint.

When a material is directly extrusion-molded into a reticulated tube, it is difficult to change the material on the way, and therefore, a base layer is previously attached to the portion to be hardened and then extrusion-molded. Therefore, there are drawbacks that it takes time and labor to manufacture, the wall thickness becomes very thick, and the outer diameter cannot be made uniform from the tip to the hand side.

In the case of the method of liquefying the material and applying it, not only various solutions for changing the flexibility have to be prepared, but the experimental result shows that the solution viscosity and the drying condition may change. There are problems such as instability in flexibility.

Therefore, according to the present invention, a flexible tube having a thin wall and a uniform wall thickness and a uniform tube diameter can be easily manufactured at low cost, and the flexibility is changed on the way. It is an object of the present invention to provide a method of manufacturing a flexible tube for an endoscope, which can prevent a rapid change in flexibility.

[0013]

In order to achieve the above-mentioned object, a method of manufacturing a flexible tube for an endoscope according to the present invention is a flexible tube in which a band is formed by an outer skin material and a mesh tube is sheathed. The above band is spirally wound around the outer surface of a certain cylindrical tube without any gap,
It is characterized in that the band is melted and then cured by heating or heating and pressurization.

The band may be composed of a plurality of bands having different hardnesses, and the plurality of bands may be spirally wound in series in series on the outer surface of the raw tube without a gap. And
Before winding the strip around the outer surface of the shell, the same material as the strip is melted or liquefied to impregnate the mesh tube,
The band may be integrated by melting the impregnated layer by melting the band, in which case the material for impregnating the reticulated tube is composed of a plurality of materials having different hardnesses after curing, The material may be sequentially impregnated into the reticulated tube at different positions in the longitudinal direction.

Fibers or braids may be included in the outer skin material, and the strips may be laminated in a plurality of layers and wound around the raw tube. In addition, a plurality of spiral tubes formed by spirally winding a metal band with a gap therebetween are arranged in a plurality of layers in the radial direction in the raw tube, and the same material as the outer skin material is melted or liquefied and impregnated. The second mesh tube may be arranged between the plural layers of spiral tubes, and an index is formed on the outer surface of the band with the same material as that of the band, and the outer surface of the index tube is made of the same hard material as the band. A material or a material of the same kind as the above-mentioned band and having a smaller coefficient of friction than the above-mentioned band may be coated.

[0016]

Embodiments will be described with reference to the drawings. Figure 1
1 shows a flexible tube 1 of an endoscope manufactured according to the present invention, in which double spiral tubes 11 and 12 in which metal strips are wound in a spiral shape with their diameters reversed with their winding directions reversed. , And a mesh tube 13 braided with fine metal or non-metal fine wire is closely attached to the outer surface of the spiral tube 1.
1, 12 and the mesh tube 13 form a base tube 10 of a flexible tube having resistance to expansion and contraction and twisting.

A material 2 for the outer skin formed on the outer surface of the tube 10.
1 is formed into a band of uniform width by a plastic material or raw rubber material having a thickness of about 0.2 to 0.3 mm, and the band 21 is formed on the outer surface of the raw pipe 10 as shown in FIG. It is wound around the mesh tube 13 in a spiral shape so that there is no gap and that the adjacent parts do not overlap each other.

The band 21 may be formed by forming a thin sheet of a plastic material or a raw rubber material by roll rolling and cutting the sheet into a band shape, and the thickness accuracy is good. If the outer peripheral surface of the reticulated tube 13 is not well wrapped,
An adhesive may be applied to the outer peripheral surface of the mesh tube 13.

In this way, after winding the band 21 around the raw tube 10, the band is melted by heating or heating and pressurization and then cured. As a result, the adjacent strips 21 that are wound in a spiral shape are melted and formed into a tube shape without a gap.

In this case, when the lines of the abutting portions of the adjacent strips 21 appear spirally, the portions are slightly melted with a solvent before heating so that the lines cannot be seen, or When a fluororesin tube or the like is tightly fixed before heating and then heated, a smooth outer skin without unevenness is obtained on the surface. Moreover, you may pressurize in addition to heating. In this way, a thin and uniform outer skin can be easily formed.

Since the plastic material or raw rubber material used for the band 21 has a limit of hardness, when a flexible tube having a higher hardness is required, natural fiber or its braid, or plastic or metal is used. The fiber 21 or the braid thereof may be included in the plastic material or the raw rubber material to form the band 21.

For example, as shown in FIG. 3, three kinds of bands 21a, 21b, and 21c having different hardnesses (flexibility) are spirally wound in series in series on the outer surface of the raw tube 10 without any gaps. The flexibility of the flexible tube 1 can be changed in three stages.

At the joint between the bands 21a, 21b, 21c, bands on both sides thereof are mixed in the tube axial direction of the flexible tube 1. The range indicated by A in FIG. 3 is that part.

Since this portion has a flexibility substantially in the middle of the portions on both sides thereof, the flexibility in the vicinity of the seam does not change abruptly by appropriately selecting the width of the bands 21a, 21b, 21c. It is possible to prevent the flexible tube from being sharply bent. 15 and 16 are spiral tubes 11, 12 at both ends.
It is a base fixed by soldering to.

The bands 21 (2) having different hardness (flexibility) are also provided.
1a, 21b, 21c) is wound around the outer surface of the base tube 10 in a spiral manner, as shown in FIG. 4 or FIG.
Combine the bands 21 with different hardness in advance,
Rolling or melt-bonding at low temperature not only improves the workability of winding, but also more reliably suppresses a rapid change in flexibility.

In this way, a flexible tube having practical utility can be manufactured at low cost, but in the embodiment shown in FIG. 1, the material 22 of the same kind as the band 21 is further heated, melted or liquid. It is liquefied and impregnated in the mesh tube 13.

This impregnation operation is performed before winding the band 21, and after the band 21 is wound, heating or heating and pressurization is applied to the band 21. Accordingly, the layer 22 and the band 21 impregnated in the reticulated tube 13 are melted and integrated, and the reticulated tube 13 and the band 21 are integrated to further improve the durability of the flexible tube. In this case, by using the same kind of material, a strong bonding force is generated between the two.

The impregnating layer 22 for the mesh tube 13 is also
A plurality of materials 22a and 22b having different hardness after curing may be sequentially impregnated by changing the position in the longitudinal direction of the mesh tube 13. By doing so, the reticulated tube 1 when the flexible tube 1 is bent
The force for restricting the movement of 3 can be made strong and weak, and the flexibility of the flexible tube 1 can be further changed on the way.

Further, as shown in FIG. 1, the mesh tube 13
If the bands 23 (23a, 23b) having different hardness are further overlapped on the bands 21a, 21b wound around the outer surface of the spiral, and the outer skin is formed by the plural layers of bands 21, 23, the entire outer skin is formed. It is possible to obtain the flexible tube 1 which is thin and yet changes in flexibility more finely and bends in a natural shape.

The second net-like tube in which the plastic material or the raw rubber material is melted or liquefied and impregnated is provided between the double spiral tubes 11 and 12, or between the spiral tubes in the case of multiple spiral tubes. If arranged, the flexible tube 1 can be made harder and the durability of the flexible tube can be increased.

Reference numeral 24 shown in FIG. 1 is an index for displaying the distance to the tip of the insertion portion of the endoscope, and the outer band 2
It is printed on the outer surface of the band 23 with the same material as that of No. 3, and is adhered to the band 23 by heating and curing.

The outer surface of the index is coated with a hard material of the same kind as the belt 23 or a material of the same kind as the belt 23 and having a smaller friction coefficient than that of the belt 22, and the outermost layer 25 having good sliding property is formed by heating under pressure. .

The present invention is not limited to the flexible tube of the insertion portion of the endoscope, but may be applied to a flexible tube of a coupling portion for coupling to a light source device or the like. In addition, an outer skin layer may be formed on the outer surface of the flexible tube manufactured according to the present invention by an extruder or the like.

[0034]

According to the method of manufacturing a flexible tube for an endoscope of the present invention, a flexible tube having a thin wall and a uniform thickness and a uniform tube diameter can be accurately and easily manufactured. And it can be manufactured at low cost.

Further, it is extremely easy to change the flexibility in the middle of the flexible tube, and moreover, it is possible to obtain excellent durability against bending by preventing the flexibility from changing rapidly. Further, it has an excellent effect that the hardness of the flexible tube can be set in a wide range.

[Brief description of drawings]

FIG. 1 is a half sectional view of a flexible tube of an endoscope according to an embodiment of the present invention.

FIG. 2 is a manufacturing process drawing of the flexible tube of the endoscope according to the embodiment of the present invention.

FIG. 3 is a manufacturing process drawing of the flexible tube of the endoscope according to the embodiment of the present invention.

FIG. 4 is a partial cross-sectional view of the flexible tube of the endoscope according to the embodiment of the present invention.

FIG. 5 is a partial cross-sectional view of the flexible tube of the endoscope according to the embodiment of the present invention.

[Explanation of symbols]

1 flexible tube 10 Elementary tube 11,12 spiral tube 13 reticulated tube 21,23 obi 22 Impregnation layer

─────────────────────────────────────────────────── --- Continuation of the front page (56) Reference JP-A-58-206715 (JP, A) JP-A-4-4132 (JP, A) JP-A-1-321014 (JP, A) JP-A-58- 92521 (JP, A) JP 59-46931 (JP, A) JP 2-283346 (JP, A) Actual development 51-8887 (JP, U) (58) Fields investigated (Int.Cl. ⁷ , DB name) A61B 1/00-1/32

Claims (7)

(57) [Claims] 1. A band is formed of an outer cover material, and the band is spirally wound around the outer surface of a flexible tubular raw tube having a mesh tube sheathed thereon, and the band is formed by heating or heating and pressurizing. In a method of manufacturing a flexible tube for an endoscope, wherein the band is melted and then cured, the band includes a plurality of bands having different hardnesses, and
The when winding <br/> that only without sequentially gaps in series helically on the outer surface of the upper Kimotokan, the boundary line between the band and the band adjacent to the difference in hardness
A method of manufacturing a flexible tube for an endoscope, characterized in that the direction is a direction other than the direction perpendicular to the axis of the flexible tube. 2. The winding material is melted or liquefied to impregnate the reticulated tube with the same kind of material as the strip, and the impregnated layer and the strip are melted before winding the strip around the outer surface of the shell. The method for manufacturing a flexible tube for an endoscope according to claim 1, wherein the and are integrated. 3. The reticulated tube is impregnated with a plurality of materials having different hardnesses after curing, and the reticulated tubes are sequentially impregnated at different positions in the longitudinal direction. 2. The method for manufacturing a flexible tube for an endoscope according to 2. 4. The method for manufacturing a flexible tube for an endoscope according to claim 1, 2 or 3, wherein the outer skin material contains a fiber or a braid. 5. The method for manufacturing a flexible tube for an endoscope according to claim 1, 2, 3 or 4, wherein the strips are superposed in a plurality of layers and wound around the tube. 6. A plurality of spiral tubes formed by spirally winding a metal band with a gap therebetween are arranged in a plurality of layers in a radial direction in the element tube, and a material similar to the outer skin material is melted or liquid. The method for manufacturing a flexible tube for an endoscope according to claim 1, wherein the second reticulated tube which has been made into and impregnated is disposed between the plurality of layers of spiral tubes. 7. An index is formed on the outer surface of the band with the same material as the band, and the outer surface is coated with a hard material of the same type as the band or a material of the same type as the band and having a smaller friction coefficient than the band. A method of manufacturing a flexible tube for an endoscope according to claim 1, 2, 3, 4, 5 or 6.