JP3231588B2 - Reticulated tube for 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 mesh tube for a flexible tube used for an exterior part of an endoscope.

[0002]

2. Description of the Related Art Generally, a flexible tube of an endoscope is formed by covering a spiral tube with a braided tube formed by braiding a plurality of wire bundles in which a plurality of thin wires are juxtaposed, and further flexing the outer tube. It is formed by covering an outer cover made of synthetic resin having properties.

[0003] For example, in Japanese Patent Application Laid-Open No. 1-223223, as shown in FIG. 8, in the axial direction of the braided tube 20, the sum of the lengths L of the intersections of the wire bundles 21 is equal to the axis of the flexible tube. It is described that the ratio to the total length is 73% to 83%.

If this is replaced with a braid density K (K = (S−s) / S in FIG. 9), which is the ratio of the area of each wire bundle 21 covering the outer peripheral surface of the braided tube 20, 1- (1) −0.73) ² = 0.9271 1− (1−0.83) ² = 0.9711, so that 0.927 ≦ K ≦ 0.971.
When there is no gap between the strands 21, s = 0 and K = 1.

[0005]

The flexible tube of the endoscope is used while being repeatedly bent with a small radius of curvature in a living body cavity or the like. Since a flexible tube using a tube has a weak bonding force between the mesh tube and the outer skin, the bend with a small radius of curvature makes it easier for the outer skin to separate from the mesh tube, and as a result, wrinkles occur in the outer skin portion inside the curve It is not uncommon for them to buckle.

In order to increase the bonding strength between the braided tube and the outer skin, the braid density of the braided tube is extremely reduced so that the softened or melted outer shell member can be sunk into the gap between the braided tubes. The member penetrates into the helical tube portion inside the mesh tube, and the flexible tube does not bend smoothly and becomes unusable.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a net tube for a flexible tube of an endoscope which has a strong bonding force with an outer skin when incorporated into the flexible tube and can bend smoothly.

[0008]

In order to achieve the above-mentioned object, a net-like tube for a flexible tube of an endoscope according to the present invention comprises a plurality of thin wires having a flat cross section whose wire width is larger than the wire thickness. A reticulated tube formed by braiding a plurality of strands of juxtaposed wires around the outer periphery of a spiral tube, and further covering the outer periphery with an outer cover made of a synthetic resin having flexibility. A braided tube for forming a tube, wherein the braid angle is between 45 ° and 65 °.
°, braid density 0.78 to 0.90, number of braid hits 1
In the case of six bundles, the number of braids n with respect to the average braid diameter D of the braided tube, where A is the width of the wire of the braided tube.
Is in the range of 0.087 D / A ≦ n ≦ 0.192 D / A.

[0009]

Embodiments will be described with reference to the drawings. FIG. 3 shows the entire configuration of the endoscope. A bending operation knob 3 provided on the operation unit 2 is turned around a distal end portion of a flexible tube 1 that covers an insertion unit connected to the operation unit 2. A curved portion 4 that is remotely bent by being moved is formed.

Further, a distal end body 5 having an objective optical system and the like is connected to the distal end side of the bending portion 4.
A connector 7 connected to a light source device (not shown) is connected to an end of the flexible connection cord 6 connected to the operation unit 2.

FIG. 1 is a partial side view showing a part of the flexible tube 1 cut away, and FIG. 2 is a partial side sectional view of the flexible tube 1. 10
Is a spiral tube formed by spirally winding a metal band such as stainless steel or a copper alloy with a uniform diameter, and is formed by single winding or multiple winding of double or more.

Reference numeral 20 denotes a mesh tube which covers the outer periphery of the spiral tube 10 and is formed by braiding a plurality of wire bundles 21 in which a plurality of wires made of thin metal wires such as stainless steel or copper alloy are arranged in parallel. ing.

The flexible tube 1 of the endoscope must be flexible and resistant to torsion, and must be thin in order to make the inner diameter as large as possible and the outer shape as thin as possible.
Therefore, the wire of the mesh tube 20 is, as shown in FIG.
It is effective to use a wire having a width A larger than the thickness B and a flat cross-sectional shape. In the present invention, such a flat wire is used.

Note that the number of wires included in one wire bundle 21 constituting the mesh tube 20 is called a holding number n, and FIG. 2 shows a case where the holding number n is n = 3. The number of strands 21 to be braided is referred to as the number of strokes m. In the present invention, the number of braided shots m is m = 16.

Numeral 30 denotes a flexible outer sheath that is coated on the outer periphery of the mesh tube 20 and is made of, for example, a synthetic resin such as polyurethane resin, and bites into the gap of the mesh tube 20 from the outer surface side.

The spiral tube 10 and the braided tube 20 are
The mesh tube 20 is closely adhered to the outer periphery of the wire, and is fixed to each other at both ends by soldering or the like. This prevents the flexible tube 1 from stretching and twisting. In this state, the angle α formed by each wire of the wire bundle 21 with respect to the axis 40 of the flexible tube 1 is called a braid angle.

Braid angle α of the reticulated tube 20 for the flexible tube of the endoscope
Is between 45 ° and 6 ° to prevent buckling when the flexible tube 1 is repeatedly bent with a small radius of curvature.
It is known that the angle should be set within a range of 5 ° (Japanese Patent Laid-Open No.
2-133925).

Further, in order that the binding force between the braided tube 20 and the outer cover 30 is strong and the flexible tube 1 can be bent smoothly, when the braid density of the braided tube 20 is K, K is in the range of 0.78 ≦ K ≦ 0.90 (strictly, 0.
(The range of 772 ≦ K ≦ 0.906) has been found by the present inventors, and a patent application has been filed earlier (Japanese Patent Application No. 7-206878).

The braid density K is, as described above,
Is the ratio of the area covering the outer peripheral surface of the mesh tube 20 (K = 1 when there is no gap). In FIG. 9, K = (S−s) /
S.

Here, it is known that the braid density K is represented by K = 2F−F ² ... F = m · n · dw / (2P · sin α). Here, F: Filling factor m: Number of braid hits n: Number of braids held dw: Diameter [mm] of the wire when the cross-sectional shape of the wire of the mesh tube 20 is circular P: Braid pitch [mm]

However, in the present invention, since the cross-sectional shape of the wire of the braided tube 20 is flat, and the braid density is related to the width A instead of the wire diameter dw. Is rewritten as

F = m · n · A / (2P · sin α)... ′ Since P = π · D / tan α..., And n ′ = (2π · sin α · F) D / A · m · tanα ... D: Braided average diameter of the braided tube 20 (outer diameter of spiral tube 10 + 2
B) [mm]. The thickness B of the strand is thus related to the average braid diameter D of the braided tube 20.

Therefore, for K, 0.772 ≦ K ≦
0.906, the value of F obtained from the equation,
By substituting the condition of 45 ° <α <65 ° for α into the equation, the braid holding number n with respect to the average braid diameter D of the braided tube 20 is calculated in the following range.

0.087 D / A ≦ n ≦ 0.192 D / A Here, n is an integer because it is the number of braids. The present invention may be applied to the connecting cord 6 having the same configuration as the flexible tube 1 described above.

[0025]

[Embodiment 1] A wire having a diameter of 0.08
Roller rolling of a thin metal wire such as a stainless steel wire or a copper alloy wire having a width (A) × thickness (B) of 0.11 mm.
An element wire having a flat cross section of mm × 0.05 mm was used.

Therefore, the braided average diameter D of the braided tube 20 is 6
mm, the number of braided strokes m is 16 bundles, and the braid angle α is 45 ° <α <
65 ° range, braid density K is 0.772 ≦ K ≦ 0.90
The number of braids n of the braided tube 20 that satisfies the condition in the range of 6.
Is a graph showing the relationship between α, K and n from FIG.
It must be in the range of 5 ≦ n ≦ 10. The numbers in the diagrams represent the braid density K in% (the same applies to FIGS. 5 to 7).

[0027]

[Embodiment 2] The wire of the mesh tube 20 has a diameter of 0.05.
Roller-rolling a thin metal wire such as a stainless steel wire or a copper alloy wire having a width (A) × a thickness (B) of 0.08 mm.
An element wire having a flat cross section of 9 mm × 0.022 mm was used.

Therefore, the braided average diameter D of the braided tube 20 is 5
mm, the number of braided strokes m is 16 bundles, and the braid angle α is 45 ° <α <
65 ° range, braid density K is 0.772 ≦ K ≦ 0.90
The number of braids n of the braided tube 20 that satisfies the condition in the range of 6.
Is a diagram showing the relationship between α, K, and n from FIG.
It must be in the range of 5 ≦ n ≦ 10.

[0029]

Embodiment 3 The wire of the mesh tube 20 has a diameter of 0.05.
Roller-rolling a thin metal wire such as a stainless steel wire or a copper alloy wire having a width (A) × a thickness (B) of 0.08 mm.
An element wire having a flat cross section of 9 mm × 0.022 mm was used.

Therefore, the braided average diameter D of the braided tube 20 is 3
mm, the number of braided strokes m is 16 bundles, and the braid angle α is 45 ° <α <
65 ° range, braid density K is 0.772 ≦ K ≦ 0.90
The number of braids n of the braided tube 20 that satisfies the condition in the range of 6.
Is a diagram showing the relationship between α, K, and n from FIG.
It must be in the range of 3 ≦ n ≦ 6.

[0031]

Embodiment 4 The wire of the mesh tube 20 has a diameter of 0.05.
Roller-rolling a thin metal wire such as a stainless steel wire or a copper alloy wire having a width (A) × a thickness (B) of 0.08 mm.
An element wire having a flat cross section of 9 mm × 0.022 mm was used.

Therefore, the braided average diameter D of the braided tube 20 is 2
mm, the number of braided strokes m is 16 bundles, and the braid angle α is 45 ° <α <
65 ° range, braid density K is 0.772 ≦ K ≦ 0.90
The number of braids n of the braided tube 20 that satisfies the condition in the range of 6.
Is a graph showing the relationship between α, K and n from FIG.
It must be in the range of 2 ≦ n ≦ 4.

[0033]

According to the present invention, in a braided flexible tube of an endoscope having 16 bundles using a flat wire, the number of braids with respect to the braided average diameter of the braided tube is determined by the number of braided wires in the braided tube. By defining the braid angle within a predetermined range corresponding to the diameter, it is possible to satisfy both the braid angle of 45 ° to 65 ° and the braid density of 0.78 to 0.90. When the flexible tube is bent, it has a strong bonding force with the outer skin and can be bent smoothly, thereby giving the flexible tube excellent durability.

[Brief description of the drawings]

FIG. 1 is a partial side view in which a part of an embodiment of a flexible tube of an endoscope according to the present invention is cut away.

FIG. 2 is a partial side sectional view of an embodiment of the flexible tube of the endoscope according to the present invention.

FIG. 3 is a side view of an embodiment of an endoscope to which the present invention is applied.

FIG. 4 is a diagram showing a range of the braid holding number of the braided tube according to the first embodiment of the present invention.

FIG. 5 is a diagram showing the range of the braid holding number of the mesh tube according to the second embodiment of the present invention.

FIG. 6 is a diagram showing a range of the braid holding number of the mesh tube according to the third embodiment of the present invention.

FIG. 7 is a diagram showing a range of the number of braids of a braided tube according to a fourth embodiment of the present invention.

FIG. 8 is a partial side view of the mesh tube.

FIG. 9 is an explanatory diagram of a braid density of a braided tube.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Flexible tube 10 Spiral tube 20 Reticulated tube 21 Element bundle 30 Outer sheath

Continued on the front page (58) Fields investigated (Int. Cl. ⁷ , DB name) A61B 1/00-1/32 G02B 23/24 Practical file (PATOLIS) Patent file (PATOLIS)

Claims (1)

(57) [Claims] An outer periphery of a helical tube is covered with a braided tube formed by braiding a plurality of wire bundles each having a plurality of thin wires having a flat cross section whose width is larger than the thickness of the wires. a mesh tube for constituting a flexible tube of an endoscope formed by coating a synthetic resin outer skin having flexibility in its outer periphery, to no 45 ° braid angle 65 °, eds Kumiuchi number 16 In the bundle, when the braid density K of the braided tube is in the range of 0.78 ≦ K ≦ 0.90 and the width of the strand of the braided tube is A, the braided average diameter of the braided tube A braided tube for a flexible tube of an endoscope, wherein the braid holding number n with respect to D is in the range of 0.087 D / A ≦ n ≦ 0.192 D / A.