JP3533109B2 - Endoscope flexible tube - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a flexible tube for an endoscope that covers the insertion portion and the like of the endoscope.

[0002]

2. Description of the Related Art A flexible tube for an endoscope is generally formed by braiding a thin metal wire on the outer surface of a spiral tube formed by spirally winding a metal or plastic strip with a constant diameter. The reticulated tube is covered, and the outer surface of the reticulated tube is covered with an outer cover made of a synthetic resin material. In recent years, the outer skin has been formed by extruding a molten synthetic resin material.

However, in the manufacturing method of forming the outer cover by simply applying the molten resin to the outer surface of the reticulated tube by extrusion molding, there is a problem that the outer cover is easily peeled off when the flexible tube is bent with a small radius of curvature during use. is there.

Therefore, conventionally, for example, Japanese Patent Publication No. 3-5872
As shown in Japanese Patent Laid-Open No. 5 and the like, an outer skin member is formed so as to wrap the mesh tube.

[0005]

However, when the mesh tube is wrapped with the outer skin member as described above, the mesh of the mesh tube is conspicuous in appearance and is not preferable in terms of quality. If it is made thicker, the outer diameter of the flexible tube becomes thicker and the insertability deteriorates.

Therefore, the present invention provides a flexible tube for an endoscope, which can effectively prevent peeling of the outer skin, and in which the mesh of the reticulated tube is not conspicuous without increasing the outer diameter. To aim.

[0007]

In order to achieve the above object, a flexible tube of an endoscope of the present invention comprises a spiral tube formed by winding a strip-shaped member in a coil shape with a gap in the pitch direction,
A reticulated tube formed by braiding a wire bundle in which a plurality of strands are arranged in a net shape and coated on the outer surface of the spiral tube, and a reticulated tube in the molten state, which is coated on the outer surface of the reticulated tube and cooled to form a tubular shape. In a flexible tube of an endoscope having a flexible outer skin, the outer skin member in a molten state is projected through the knitted portion of the interstitial mesh tube to be scattered in the pitch direction gap of the spiral tube,
A brim-shaped portion that spreads laterally is formed at the tip of the protruding portion.

[0008] Then, by ensuring that the molten outer skin member does not enter between the outer peripheral surface of the spiral tube and the inner peripheral surface of the mesh tube, the wall thickness of the outer shell is made sufficiently large in the outer portion of the mesh tube. Can be secured.

It should be noted that the projecting portion passes through the pitch direction clearance of the spiral tube, and the collar-shaped portion formed at the projecting end thereof spreads wider than the pitch direction clearance inside the inner surface of the spiral tube. It is preferable that the ridge-shaped portion extends larger than the diameter of the mesh of the reticulated tube.

Further, when a plurality of spiral tubes are arranged so as to be overlapped with each other, a continuous projecting portion may be formed so as to project from the outer skin side in each gap in the pitch direction of the plurality of spiral tubes.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described with reference to the drawings. FIG. 3 shows the overall configuration of the endoscope,
The insertion portion to be inserted into the body cavity is covered by the flexible tube 1, and the base end thereof is connected to the lower end portion of the operation portion 2.

A bending portion 3 which can be bent at an arbitrary angle in an arbitrary direction by a remote operation from an operation knob 4 arranged on an operation portion 2 is connected to a tip of the flexible tube 1, and an objective optical system is provided. A tip portion main body 5 including the above is connected to the tip of the bending portion 3.

A connector 7 connected to a video processor / light source device (not shown) is attached to the tip of the flexible connecting pipe 6 connected to the vicinity of the upper end of the operating portion 2.

FIG. 4 shows the constituent members of the flexible tube 1 of the insertion portion peeled off one by one, and the innermost layer is a strip-shaped member made of, for example, stainless steel or copper alloy with a gap 11 in the pitch direction. The spiral tube 10 is formed by winding it in a coil shape. The spiral tube 10 is single here, but may be double or triple or more in which the winding directions are sequentially different as described later.

The outer surface of the spiral tube 10 is covered with a reticulated tube 20 formed by braiding a wire bundle in which a plurality of metal or non-metal element wires are arranged in a reticulated shape. The outer surface is covered with a flexible skin 30. 21 is the stitches of the reticulated tube 20 which are uniformly scattered.

The outer cover 30 is made of, for example, a member containing polyurethane resin as a main component, and the pellets of the raw material are put into an extrusion molding machine and directly coated on the outer surface of the reticulated tube 20 while being heated and melted. It is cooled and formed into a tube.

When the outer cover 30 is extrusion-molded, the cored bar 100 is passed through the spiral tube 10 and is removed after cooling. FIG. 1 is a partial side sectional view (a sectional view in a direction including an axis) of the flexible tube 1 in a state where the core metal 100 is being passed and is being cooled, and FIG. 2 is a state after the core metal 100 is removed. FIG. 3 is a front partial cross-sectional view (cross-sectional view in a direction perpendicular to the axis).

The outer peripheral surface of the spiral tube 10 and the inner peripheral surface of the reticulated tube 20 are in close contact with each other, and the outer skin 30 is formed between the outer peripheral surface of the spiral tube 10 and the inner peripheral surface of the reticulated tube 20 even when the material is in a molten state. I'm not in between.

However, in the melted state at the time of extrusion molding, the outer skin member passes through the knitting 21 portion of the mesh tube 20 and is projected in a state of being scattered in the gap 11 in the pitch direction of the inner spiral tube 10, and is cooled and hardened as it is. ing. 31 is the protrusion.

The protrusion 31 passes through the gap 11 in the pitch direction of the spiral tube 10. Then, a flange-shaped portion 31a that spreads laterally is formed at the tip of the protruding portion 31, and is cooled and hardened in this state.

As shown in FIG. 1, the brim-shaped portion 31a is formed by the projection end of the projection 31 coming into contact with the surface of the cored bar 100 and slightly expanding in the lateral direction, so as to extend along the inner surface of the spiral tube 10. The gap 11 in the pitch direction of the spiral tube 10
It has a wider width.

As a result, during extrusion molding of the outer cover 30,
Since the reticulated tube 20 and the spiral tube 10 are sandwiched between the outer skin 30 and the collar-shaped portion 31a that are integrally connected to each other via the protruding portion 31, the flexible tube 1 is bent with a small radius of curvature. However, the outer cover 30 does not peel off from the surface of the reticulated tube 20, and wrinkles and buckling do not occur.

5 and 6 show a flexible tube 1 according to a second embodiment of the present invention, FIG. 5 is a side partial sectional view, and FIG. It is a compound front sectional view shown.

In this embodiment, as compared with the flexible tube 1 of the first embodiment described above, the protrusion amount of the protruding portion 31 protruding inward from the stitch 21 of the reticulated tube 20 is changed to the spiral tube. The only difference is that it is shallow enough not to reach the inner peripheral surface of 10.

As a result, the gap 1 in the pitch direction of the spiral tube 10
Although the protrusion amount of each protrusion 31 existing only in 1 is not constant and varies, the mesh tube 20 is sandwiched between the collar-shaped portion 31 a formed at the tip of the protrusion 31 and the outer skin 30, and the outer skin 30 Peeling is prevented.

FIG. 7 is a partial side sectional view of the flexible tube 1 according to the third embodiment of the present invention, in which the protruding portion 31 has the spiral tube 10.
It is accommodated in the pitch direction gap 11 and is formed to be wider than the diameter of the stitch 21 of the reticulated tube 20. The core metal 100 can be formed in this manner by inserting the core metal 100 into contact with the inner surface of the spiral tube 10.

Others are the same as those in the first embodiment, and the protrusion 31 is formed when the outer cover 30 is extruded.
The outer skin 30 and the collar-shaped portion 31a which are integrally connected via
Since the reticulated tube 20 is sandwiched between and, the outer tube 3 can be bent even if the flexible tube 1 is bent with a small radius of curvature.
0 does not separate from the surface of the reticulated tube 20, and wrinkles and buckling do not occur.

FIG. 8 is a partial side sectional view of the flexible tube 1 according to the fourth embodiment of the present invention. Here, the pitch direction gaps 1 of the spiral tube 10 that are arranged so as to be overlapped with each other inside and outside
1 is formed with a continuous protruding portion 31, and the protruding end thereof abuts the surface of the cored bar 100 and spreads in the lateral direction so that the collar-shaped portion 3
1a is formed.

In the third and fourth embodiments as well, as in the first embodiment, the core metal 100 and the spiral tube 10 are used.
The collar-shaped portion 31a may be made slightly smaller than the inner peripheral surface of the spiral tube 10 so as to extend along the inner peripheral surface of the spiral tube 10.

Further, the present invention may be applied to the flexible connecting pipe 6.

[0031]

According to the present invention, the outer skin member in a molten state is projected so as to be scattered in the pitch direction gap of the spiral tube through the knitted portions of the interspersed mesh tube, and is spread laterally. A mesh tube (or a mesh tube and a spiral tube) is sandwiched between the collar and the outer skin, which is integrally connected via the protrusion, by cooling and hardening in the state where the protrusion is formed on the protrusion end. Since the flexible tube is mechanically sandwiched, the outer skin does not separate from the surface of the mesh tube even when the flexible tube is bent with a small radius of curvature, and wrinkles and buckling do not occur.

Moreover, the collar-shaped portion can be formed at the same time when the outer cover is extruded, and the outer cover surrounds the outer side of the reticulated tube rather than wrapping the reticulated tube, so that the outer diameter of the outer cover is not increased. The wall thickness can be secured, and the mesh of the reticulated tube is inconspicuous in appearance.

[Brief description of drawings]

FIG. 1 is a side partial cross-sectional view of a flexible tube of an endoscope according to a first embodiment of the present invention.

FIG. 2 is a front partial cross-sectional view of the flexible tube of the endoscope according to the first embodiment of the present invention.

FIG. 3 is an overall external view of the endoscope according to the embodiment of the present invention.

FIG. 4 is a side view showing the constituent members of the flexible tube of the embodiment of the present invention peeled off one by one in order.

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

FIG. 6 is a composite front cross-sectional view of the flexible tube of the endoscope according to the second embodiment of the present invention.

FIG. 7 is a partial side sectional view of a flexible tube of an endoscope according to a third embodiment of the present invention.

FIG. 8 is a partial side sectional view of a flexible tube of an endoscope according to a fourth embodiment of the present invention.

[Explanation of symbols]

1 flexible tube 10 spiral tube 11 Pitch direction gap 20 reticulated tube 21 stitches 30 outer skin 31 Projection 31a Collar-shaped portion

─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Minoru Matsushita 2-36-9 Maenocho, Itabashi-ku, Tokyo Inside Asahi Optical Co., Ltd. (56) Reference JP-A-58-221926 (JP, A) JP 61-47918 (JP, A) JP-A-63-125232 (JP, A) Furukaihei 1-112801 (JP, U) (58) Fields investigated (Int.Cl. ⁷ , DB name) A61B 1 / 00-1/32

Claims (3)

(57) [Claims] 1. A spiral tube formed by winding a band-shaped member in a coil shape with a gap in the pitch direction, and a wire bundle in which a plurality of wires are arranged side by side are braided in a net shape to form an outer surface of the spiral tube. A flexible tube of an endoscope having a covered reticulated tube and a flexible outer shell that is cooled and formed into a tubular shape by being coated on the outer surface of the reticulated tube in a molten state. , by inwardly projecting state passing through the pitch direction gap of the helical tube through the stitch portion of the mesh tube that dot, inner smell from the inner surface of the helical tube
A flexible tube for an endoscope, characterized in that a brim-shaped portion that widens laterally with a width wider than the pitch direction gap is formed at a projection end of the projection. 2. The flexible tube for an endoscope according to claim 1, wherein the outer skin member in a molten state is not inserted between the outer peripheral surface of the spiral tube and the inner peripheral surface of the reticulated tube. 3. A have been placed in the helical tube is more superimposed, endoscopic of claim 1 or 2, wherein the protruding portions of a stretch in the pitch direction clearance of the plurality of helical tube is formed Mirror flexible tube.