JP3515704B2 - Flexible tube for endoscope and method for manufacturing the same - 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 come to be formed from a molten material by extrusion molding.

When a tube was used as the outer skin member, a slightly thin tube was spread by air pressure or the like to cover the outer skin member, so that the outer skin and the reticulated tube were well bonded and a strong peel strength was obtained.

However, in the manufacturing method in which the outer skin is formed by simply applying the molten resin to the outer surface of the reticulated tube by extrusion molding, the outer skin is easily peeled off from the reticulated tube and it is difficult to obtain sufficient peel strength.

Therefore, for example, as shown in Japanese Patent Publication No. 2-51601 and Japanese Patent Publication No. 3-42896,
When the outer shell material is in a molten state, it wraps around the gap between the mesh tube and the spiral tube, or is filled in the gap in the pitch direction of the spiral tube through the mesh portion of the mesh tube so that the hardened skin member wraps the mesh tube. I was doing.

[0006]

However, when the net tube is wrapped with the hardened skin member as described above, the flexibility between the shell and the net tube is lost because the flexibility between the shell and the net tube is completely lost. If the outer shell resin is filled in the pitch direction gap of the spiral tube, the movement of the spiral tube is remarkably restricted, and the flexibility also deteriorates.

[0007] Therefore, an object of the present invention is to provide a flexible tube for an endoscope which enables the outer skin to obtain a sufficient peeling strength and also has good flexibility.

[0008]

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 filaments are arranged in a net shape and coated on the outer surface of the spiral tube, and a tube formed by coating the outer surface of the reticulated tube in a molten state in a tubular shape. In a flexible tube of an endoscope having a flexible outer skin, a molten outer skin member is projected into a pitch direction gap of the spiral tube through a mesh portion of the reticulated tube, and within two or several places. The protruding portions are formed so as to be partially connected to each other in each portion in the pitch direction gap of the spiral tube.

Further, according to the method of manufacturing a flexible tube for an endoscope of the present invention, a plurality of strands are arranged on the outer surface of a spiral tube formed by winding a strip-shaped member in a coil shape with a gap in the pitch direction. In a method of manufacturing a flexible tube for an endoscope in which a mesh tube formed by braiding a wire bundle in a mesh shape is coated, and the outer surface of the mesh tube is extruded to form a flexible outer sheath, melting by extrusion molding is performed. The outer shell member in the state is projected into the pitch direction gap of the spiral tube through the mesh portion of the reticulated tube, and two or several protruding portions are part of each portion in the pitch direction gap of the spiral tube. It is characterized in that they are formed in a state in which they are physically connected.

In the flexible tube of the endoscope and the manufacturing method thereof, it is preferable that the outer skin member in a molten state does not enter between the outer peripheral surface of the spiral tube and the inner peripheral surface of the reticulated tube. The outer skin member may be a fluoroelastomer.

In the above manufacturing method, the outer cover may be vulcanized after extrusion molding.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described with reference to the drawings. FIG. 4 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 distal end of the flexible tube 1 to form an objective optical system. 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 operation unit 2.

FIG. 5 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 changed.

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 elemental wires are arranged in a reticulated shape. The outer surface is covered with a flexible skin 30. 21 is a stitch.

The outer cover 30 is formed of a member whose main component is a fluoroelastomer such as fluororubber, and the raw material is put into an extrusion molding machine and heated on the outer surface of the reticulated tube 20. It is directly coated and cooled as it is to form a tube. The fluorine-based elastomer is very suitable for use as the spiral tube 10 of the flexible tube of the endoscope in terms of compression set resistance, chemical resistance, heat resistance, abrasion resistance, slippage, and the like. .

FIG. 3 shows a flexible tube 1 in a cross section including 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 in contact with the outer peripheral surface of the spiral tube 10 and the inner surface of the reticulated tube 20 even in a molten state of the material. Do not get in between the circumference.

However, in the molten state at the time of extrusion molding, the outer skin member passes through the knitting 21 portion of the reticulated tube 20 and is projected in a state of being scattered in the pitch direction gaps 11 of the inner spiral tube 10. 31 is the protrusion.

The protrusions 31 within two or several places
They are partially connected at each part in the pitch direction gap 11 of the spiral tube 10. Reference numeral 32 denotes the connecting portion, and "within several places" means within 5 to 6 places, for example. Both the protruding portion 31 and the connecting portion 32 are cooled and hardened similarly to the outer cover 30.

With such a structure, the pressure, viscosity, or drawing speed of the molten material during extrusion molding is adjusted, and the reticulated tube 20 is used.
The braid 21 of the reticulated tube 20 depends on the braiding conditions, the thickness of the cored bar that is passed through the spiral tube 10 during forming, the formation of the outer surface groove, and the like.
This can be achieved by adjusting the amount of protrusion of the protrusion 31 from the.

FIGS. 1 and 2 show a protrusion 31 and a connecting portion 32 in the pitch gap 11 of the spiral tube 10.
The state is shown in an enlarged manner, and the outer cover member wraps the reticulated tube 20 only in the portion where the connecting portion 32 is present.

As a result, although the fluoroelastomer has poor adhesiveness and high peelability from metal, the outer skin 30 does not peel from the mesh tube 20, and the flexible tube 1 is easily bent repeatedly. Does not buckle.

Further, if the connecting portion 32 is filled so as to completely fill the pitch direction clearance 11 of the spiral tube 10, the flexibility of the flexible tube 1 will be deteriorated, but this is the case. In addition, since the outer skin member wraps the reticulated tube 20 in only a part, it has good flexibility and does not lose its flexibility.

After the outer cover 30 is extruded and molded using fluororubber or the like as a material, primary vulcanization and secondary vulcanization are preferably performed. As a result, a three-dimensional network structure is created, and it is possible to prevent plastic flow of the raw material rubber and develop rubber elasticity.

The present invention is not limited to the above embodiment, and for example, any material other than the fluorine-based elastomer may be used as the material of the outer cover 30 as long as it can be extruded. Alternatively, the present invention may be applied to the flexible connecting pipe 6 and the like.

[0027]

According to the present invention, the outer skin member in a molten state is projected into the gap in the pitch direction of the spiral tube through the mesh portion of the reticulated tube, and the projecting portions within two or several places are spiral tubes. Since the outer skin is not separated from the surface of the reticulated tube, the flexible tube is not easily buckled even if the flexible tube is repeatedly bent. In addition, since the outer skin member wraps the mesh tube only in part, the flexible tube has good flexibility and does not lose its flexibility.

[Brief description of drawings]

FIG. 1 is a partially enlarged cross-sectional view of a protruding portion and a connecting portion of an outer cover member according to an embodiment of the present invention.

FIG. 2 is a partially enlarged front view of a projecting portion and a connecting portion of the outer cover member according to the embodiment of the present invention.

FIG. 3 is a half cross-sectional view of a cross section including an axis of the flexible tube according to the embodiment of the present invention.

FIG. 4 is an overall external view of the endoscope according to the embodiment of the present invention.

FIG. 5 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.

[Explanation of symbols]

1 flexible tube 10 spiral tube 11 Pitch direction gap 20 reticulated tube 21 stitches 30 outer skin 31 Projection 32 connection

Front Page Continuation (72) Inventor Shinji Hayakawa 2-36 Maenocho, Itabashi-ku, Tokyo Asahi Optical Industry Co., Ltd. (56) Reference JP-A-59-46931 (JP, A) JP-A-58- 221926 (JP, A) JP 9-51870 (JP, A) JP 61-47918 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB name) A61B 1/00-1 / 32

Claims (7)

(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. In a flexible tube of an endoscope having a covered reticulated tube and a flexible outer shell formed in a molten state by being coated on an outer surface of the reticulated tube, a molten outer shell member is It was formed to protrude through the mesh portion of the reticulated tube into the pitch direction clearance of the spiral tube, and two or several protruding parts were formed so as to be partially connected at each part in the pitch direction clearance of the spiral tube. A flexible tube for an endoscope, which is characterized in that 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. The flexible tube for an endoscope according to claim 1, wherein the outer skin member is a fluorine-based elastomer. 4. A reticulated tube formed by braiding a wire bundle in which a plurality of element wires are arranged in a reticulated shape on the outer surface of a spiral tube formed by winding a band-shaped member in a coil shape with a gap in the pitch direction. Then, in the method of manufacturing a flexible tube for an endoscope in which the outer surface of the reticulated tube is covered with a flexible outer cover by extrusion molding, the outer skin member in a molten state by extrusion molding is passed through the mesh portion of the reticulated tube. An endoscope characterized in that it is formed so as to project into the pitch direction gap of the spiral tube, and two or a few projecting portions are partially connected to each other in the pitch direction gap of the spiral tube. Manufacturing method of flexible tube. 5. The method of manufacturing a flexible tube for an endoscope according to claim 4, wherein the outer skin member in a molten state does not enter between the outer peripheral surface of the spiral tube and the inner peripheral surface of the reticulated tube. 6. The flexible tube for an endoscope according to claim 4, wherein the outer skin member is a fluorine-based elastomer. 7. The method of manufacturing a flexible tube for an endoscope according to claim 6, wherein the outer cover is vulcanized after the outer cover is extruded and molded.