JP3331128B2 - 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 In general, 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 periphery of the spiral 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. 7, 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. 8), which is the ratio of the area of each wire bundle 21 covering the outer peripheral surface of the braided tube 20, −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 braided tube and the outer skin, the bend with a small radius of curvature makes it easier for the outer skin to peel off from the braided tube, and as a result, wrinkles are generated 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 well penetrated 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 object, a net tube for a flexible tube of an endoscope according to the present invention comprises a net tube formed by braiding a plurality of wire bundles in which a plurality of thin wires are juxtaposed. A mesh tube for forming a flexible tube of an endoscope in which the outer periphery of a spiral tube is covered, and the outer periphery of the spiral tube is further covered with a flexible synthetic resin skin, wherein the braid angle is 45 °. ° to 6
5 °, the braid density is 0.78 to 0.90, and the number of braid hits is 24 bundles.
Wherein the braid holding number n with respect to the braid average diameter D of the braided pipe is in the following range.

When dw = 0.02 mm, 2.89D ≦ n ≦ 6.41D When dw = 0.03 mm, 1.93D ≦ n ≦ 4.27D When dw = 0.04 mm, 1.45D ≦ n ≤3.20D dw = 0.05mm, 1.16D≤n≤2.56D dw = 0.06mm, 0.97D≤n≤2.13D dw = 0.07mm, 0.83D≤ When n ≦ 1.83D dw = 0.08 mm, 0.73D ≦ n ≦ 1.60D dw = 0.09 mm, 0.65D ≦ n ≦ 1.42D When dw = 0.10 mm, 0.58D ≦ n ≦ 1.28D When dw = 0.12 mm, 0.49D ≦ n ≦ 1.06D.

[0010] The maximum value of the average diameter D of the braid of the braided tube is preferably in the following range. When dw = 0.02 mm, 1.9 mm ≦ D ≦ 4.1 mm When dw = 0.03 mm, 2.9 mm ≦ D ≦ 6.2 mm When dw = 0.04 mm, 3.8 mm ≦ D ≦ 8. When 2 mm dw = 0.05 mm, 4.7 mm ≦ D ≦ 10.3 mm When dw = 0.06 mm, 5.7 mm ≦ D ≦ 12.3 mm When dw = 0.07 mm, 6.6 mm ≦ D ≦ 14 When 0.4 mm dw = 0.08 mm, 7.5 mm ≦ D ≦ 16.4 mm When dw = 0.09 mm, 8.5 mm ≦ D ≦ 18.4 mm When dw = 0.10 mm, 9.4 mm ≦ D ≦ When 20.6 mm dw = 0.12 mm, 11.4 mm ≦ D ≦ 24.4 mm.

[0011]

Embodiments will be described with reference to the drawings. FIG. 2 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 shows the structure of the flexible tube 1.
Reference numeral 0 denotes 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. However, a thin metal wire and a non-metal thin wire may be mixed and arranged. The number of wires included in one wire bundle 21 is called a holding number n, and the number of the wire bundles 21 to be braided is called a stroke number m. In the present invention, the number of braided shots m is m = 2
4.

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 a 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. 8, 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 strikes n: Number of braids held dw: Element diameter of the braided tube 20 [mm] P: Braid pitch [mm]

Since P = π · D / tan α... And from the equation, n = (2π · sin α · F) D / dw · m · tan α. Here, D: average braid diameter of the braided tube 20 (core outer diameter + 2 dw)
[Mm].

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 braid average diameter D of the braided tube 20 is calculated in the following range.

When dw = 0.02 mm, 2.89 D ≦ n ≦ 6.41 D When dw = 0.03 mm, 1.93 D ≦ n ≦ 4.27 D When dw = 0.04 mm, 1.45 D ≦ n ≤3.20D dw = 0.05mm, 1.16D≤n≤2.56D dw = 0.06mm, 0.97D≤n≤2.13D dw = 0.07mm, 0.83D≤ When n ≦ 1.83D dw = 0.08 mm, 0.73D ≦ n ≦ 1.60D dw = 0.09 mm, 0.65D ≦ n ≦ 1.42D When dw = 0.10 mm, 0.58D ≦ n ≦ 1.28D When dw = 0.12 mm, 0.49D ≦ n ≦ 1.06D, where n is an integer because it is the number of braids.

If the number of braids n is too large, it is preferable to set the number of the braids to 12 or less (one or more), since it is troublesome to bundle the wires and the production cost is increased. Therefore, the maximum value of the average braid diameter D with respect to the wire diameter dw is desirably in the following range.

When dw = 0.02 mm, 1.9 mm ≦ D ≦ 4.1 mm When dw = 0.03 mm, 2.9 mm ≦ D ≦ 6.2 mm When dw = 0.04 mm, 3.8 mm ≦ D ≦ 8.2 mm dw = 0.05 mm, 4.7 mm ≦ D ≦ 10.3 mm dw = 0.06 mm, 5.7 mm ≦ D ≦ 12.3 mm dw = 0.07 mm, 6.6 mm ≦ When D ≦ 14.4 mm dw = 0.08 mm, 7.5 mm ≦ D ≦ 16.4 mm dw = 0.09 mm, 8.5 mm ≦ D ≦ 18.4 mm When dw = 0.10 mm, 9.4 mm ≦ D ≦ 20.6 mm When dw = 0.12 mm, 11.4 mm ≦ D ≦ 24.4 mm.

The present invention may be applied to the connecting cord 6 having the same structure as that of the above-described flexible tube 1.

[0027]

Embodiment 1 The average diameter D of the braid of the braided tube 20 is 10 mm,
The conditions are as follows: the number of braided strokes m is 24 bundles, the strand diameter dw is 0.12 mm, the braid angle α is in the range of 45 ° ≦ α ≦ 65 °, and the braid density K is in the range of 0.772 ≦ K ≦ 0.906. The braid holding number n of the mesh tube 20 to be satisfied must be in the range of 5 ≦ n ≦ 10 according to FIG. 3 showing the relationship between α, K and n by a diagram. The numbers in the diagrams represent the braid density K in% (the same applies to FIGS. 4 to 6).

[0028]

Embodiment 2 The average braid diameter D of the braided tube 20 is 8 mm, the number m of braids is 24 bundles, the wire diameter dw is 0.08 mm, the braid angle α is in the range of 45 ° ≦ α ≦ 65 °, and the braid density K Is 0.
The braid holding number n of the mesh tube 20 satisfying the condition of 772 ≦ K ≦ 0.906 must be in the range of 6 ≦ n ≦ 12 from FIG. 4 showing the relationship between α, K and n by a diagram. Must.

[0029]

Embodiment 3 The average braid diameter D of the braided tube 20 is 4 mm, the number m of braids is 24 bundles, the wire diameter dw is 0.04 mm, the braid angle α is in the range of 45 ° ≦ α ≦ 65 °, the braid density K Is 0.
The braid holding number n of the braided tube 20 satisfying the condition of 772 ≦ K ≦ 0.906 must be in the range of 6 ≦ n ≦ 12 from FIG. 5 showing the relationship between α, K and n by a diagram. Must.

[0030]

Embodiment 4 The average braid diameter D of the braided tube 20 is 2 mm, the number of braids per m is 24 bundles, the strand diameter dw is 0.02 mm, the braid angle α is in the range of 45 ° ≦ α ≦ 65 °, the braid density K Is 0.
The braid holding number n of the braided tube 20 satisfying the condition of 772 ≦ K ≦ 0.906 must be in the range of 6 ≦ n ≦ 12 from FIG. 6 showing the relationship between α, K and n by a diagram. Must.

[0031]

According to the present invention, in a braided tube for a flexible tube of an endoscope having 24 bundles, the number of braids with respect to the average braided diameter of the braided tube is determined in accordance with the wire diameter of the braided tube. Satisfies both the braid angle of 45 ° to 65 ° and the braid density of 0.78 to 0.90, and can be combined with the outer skin when incorporated in the flexible tube. It is strong and can be bent smoothly, so that the flexible tube can be provided with 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 side view of an embodiment of an endoscope to which the present invention is applied.

FIG. 3 is a diagram showing a range of the braid holding number of the mesh tube according to the first embodiment of the present invention.

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

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

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

FIG. 7 is a partial side view of the mesh tube.

FIG. 8 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

──────────────────────────────────────────────────続 き Continued on the front page (58) Fields surveyed (Int. Cl. ⁷ , DB name) A61B 1/00-1/32

Claims (2)

(57) [Claims] An outer periphery of a helical tube is covered with a braided tube formed by braiding a plurality of wire bundles in which a plurality of thin wires are juxtaposed, and an outer periphery of a flexible synthetic resin is further covered on the outer periphery. A braided tube for forming a flexible tube of an endoscope having a braid angle of 45 ° to 65 °, a braid density of 0.78 to 0.90, and a braided number of bundles of 24 bundles. A braided tube for a flexible tube of an endoscope, wherein the braid holding number n with respect to the braided average diameter D of the braided tube is in the following range, where dw is the wire diameter of the braided tube. When dw = 0.02 mm, 2.89D ≦ n ≦ 6.41D When dw = 0.03 mm, 1.93D ≦ n ≦ 4.27D When dw = 0.04 mm, 1.45D ≦ n ≦ 3. When 20D dw = 0.05 mm, 1.16D ≦ n ≦ 2.56D When dw = 0.06 mm, 0.97D ≦ n ≦ 2.13D When dw = 0.07 mm, 0.83D ≦ n ≦ 1 0.83D dw = 0.08mm, 0.73D ≦ n ≦ 1.60D dw = 0.09mm, 0.65D ≦ n ≦ 1.42D dw = 0.10mm, 0.58D ≦ n ≦ When 1.28D dw = 0.12 mm, 0.49D ≦ n ≦ 1.06D. 2. A reticulated tube for a flexible tube of an endoscope according to claim 1, wherein the maximum value of the average diameter D of the braid is in the following range. When dw = 0.02 mm, 1.9 mm ≦ D ≦ 4.1 mm When dw = 0.03 mm, 2.9 mm ≦ D ≦ 6.2 mm When dw = 0.04 mm, 3.8 mm ≦ D ≦ 8. When 2 mm dw = 0.05 mm, 4.7 mm ≦ D ≦ 10.3 mm When dw = 0.06 mm, 5.7 mm ≦ D ≦ 12.3 mm When dw = 0.07 mm, 6.6 mm ≦ D ≦ 14 When 0.4 mm dw = 0.08 mm, 7.5 mm ≦ D ≦ 16.4 mm When dw = 0.09 mm, 8.5 mm ≦ D ≦ 18.4 mm When dw = 0.10 mm, 9.4 mm ≦ D ≦ When 20.6 mm dw = 0.12 mm, 11.4 mm ≦ D ≦ 24.4 mm.