JP2002058637A - Flexible tube for endoscope - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a flexible tube for endoscope, whose weight of the tip end side is lightened to reduce the load on a part A around the operating part to enable to prevent degradation and breakage of the part A around the operating part. SOLUTION: This flexible tube 10 of an inserting part for endoscope comprises a core material 2 and an envelope 3 to cover the periphery of the core material 2. The envelope 3 is constituted of a laminate with an inner layer 31 and an outer layer 32. The outer layer 32 has a first area 32a positioned to the base end 11 side and a second area 32b positioned to the tip end 12 side. A border part 34 is formed in between the first area 32a and the second area 32b. The second area 32b is made of a material with specific gravity lower than that of the first area 32a. Thus the weight of a part from the center in the longitudinal direction to the tip end 12 side of the flexible tube 10 of inserting part is made lighter than the weight of a part from the center of the longitudinal direction to the base end 11 side.

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.

[0002]

2. Description of the Related Art Medical endoscopes are used in medical procedures such as examination and treatment of diseases. FIG. 8 is a diagram showing an example of a conventional medical endoscope, and FIG. 9 is an enlarged perspective view showing a distal end portion of an insertion portion of the endoscope shown in FIG.

[0005] An endoscope 50 shown in FIG. 8 has a long insertion portion 5 to be inserted into a body cavity. The insertion portion 5 has a tubular shape, and an optical fiber,
Wires, cables, tubes, etc. are arranged,
It has been inserted.

[0004] Except for the vicinity of the distal end of the insertion portion 5 (the curved portion 52 and the foremost portion 53), a flexible (elastic) insertion portion flexible tube (flexible tube for endoscope) 51 is provided. It is configured.
The insertion section flexible tube 51 generally has a configuration in which a core material having a hollow portion in which the outer periphery of a spiral tube is covered with a mesh tube is covered with a sheath made of synthetic resin, synthetic rubber, or the like.

[0005] A bending portion 52 is connected to a distal end 51 b of the insertion portion flexible tube 51. The bending portion 52 can freely remotely control the bending direction via a wire disposed inside the insertion portion 5. In addition, the bending portion 5
A leading end 53 is provided at the tip of 2.

The proximal end 51 a of the flexible tube 51 is connected to the operating section 41. The operation section 41 is a section provided with an operation system such as an operation knob 42 for operating the bending direction of the bending section 52, so that the operator can grip and operate the entire endoscope 50. I have.

However, when the endoscope 50 is lifted while holding the operation section 41 without supporting the insertion section 5, the insertion section 5 hangs largely downward due to its weight. FIG. 8 shows such a state. Insertion part 5
Is long so that it can reach deep into a body cavity such as the stomach, duodenum, small intestine or large intestine.
The part A near the first operation unit 41 receives a large load (bending moment).

[0010] Further, as shown in FIG.
The distal end portion 53 is provided with the distal end components of the observation optical system and the illumination optical system (the objective lens 46 and the light guide distal end portion 47), the forceps channel 48, and the air supply / water supply port 49. Since the portion 53 is heavy, the flexible tube 5
The burden on the part A near the operation unit 1 is larger.

As described above, in the flexible tube 51 of the insertion portion, since the portion A near the operation portion is repeatedly subjected to a large load (bending moment), the inner core material is plastically deformed in that portion, and the outer skin is not formed. There is a problem that deterioration or breakage is apt to occur due to peeling or the like.

[0010]

SUMMARY OF THE INVENTION It is an object of the present invention to reduce the load on the portion A near the operating portion by reducing the weight of the portion on the distal end side, and to reduce the deterioration of the portion A near the operating portion. To provide a flexible tube for an endoscope which can prevent the endoscope from being damaged.

[0011]

This and other objects are achieved by the present invention which is defined below as (1) to (11).

(1) A flexible tube for an endoscope having a core material having a hollow portion and an outer coat coated on the outer periphery of the core material, the weight of a portion on the distal end side from the center in the longitudinal direction. Is configured to be lighter than the weight of a portion closer to the base end than the center in the longitudinal direction.

[0013] This makes it possible to provide a flexible tube for an endoscope in which the burden on the portion A near the operation portion is reduced, and the deterioration and breakage of the portion A near the operation portion can be prevented.

(2) The flexible tube for an endoscope is equally divided into n (n is any natural number from 3 to 10) portions having the same length along the longitudinal direction. The flexible tube for an endoscope according to the above (1), wherein the weight of each of these portions is reduced in order from the proximal portion to the distal portion.

This makes it possible to more effectively prevent the portion A near the operation portion from being deteriorated or damaged.

(3) A flexible tube for an endoscope having a core material having a hollow portion and an outer skin coated on the outer periphery of the core material, wherein the flexible tube for the endoscope has a fixed length. A flexible tube for an endoscope, wherein a weight per contact decreases from a base end thereof to a distal end thereof.

Thus, a load on the portion A near the operation portion is reduced, and a flexible tube for an endoscope can be provided which can prevent the portion A near the operation portion from being deteriorated or damaged.

(4) The above (1) to (3), wherein the change of the weight of the outer skin along the longitudinal direction contributes to the change of the weight of the flexible tube for an endoscope along the longitudinal direction. The flexible tube for an endoscope according to any one of the above.

Thus, a flexible tube for an endoscope which can prevent deterioration or breakage of the portion A near the operation portion can be realized with a simple structure that can be easily manufactured.

(5) The flexible tube for an endoscope according to any one of the above (1) to (4), wherein the outer skin has a single-layer or multi-layer laminated structure. Thereby, various excellent characteristics can be imparted to the flexible tube for an endoscope.

(6) By changing the thickness and / or the constituent material of at least one of the layers constituting the outer skin along the longitudinal direction, the weight per fixed length of the outer skin in the longitudinal direction is changed. (5) The flexible tube for an endoscope according to the above (5), wherein the flexible tube is changed along the length.

Thus, a flexible tube for an endoscope which can prevent deterioration or breakage of the portion A near the operation portion can be realized with a simple structure that can be easily manufactured.

(7) At least one of the layers constituting the outer shell has a plurality of regions along the longitudinal direction, and the specific gravity of the material constituting each region is from the region on the base end side to the region on the distal end side. The flexible tube for an endoscope according to the above (5) or (6), which is configured to become smaller in order to the region.

Thus, a flexible tube for an endoscope which can prevent deterioration or breakage of the portion A near the operation section can be realized with a simple structure that can be easily manufactured.

(8) The flexible tube for an endoscope according to any one of the above (1) to (7), wherein the thickness of the outer skin is substantially constant along the longitudinal direction. Thereby, the operability of the insertion is improved.

(9) The core material includes a spiral tube formed by spirally winding a belt-like material, and a braided body formed by braiding a thin wire and covering the outer periphery of the spiral tube. The flexible tube for an endoscope according to any one of (1) to (8). Thereby, sufficient mechanical strength can be secured.

(10) The outer shell is made of a material containing at least one selected from the group consisting of polyurethane elastomers, polyester elastomers, polyolefin elastomers, polystyrene elastomers, polyamide elastomers, fluorine elastomers, and fluorine rubbers. The flexible tube for an endoscope according to any one of the above (1) to (9), which has a configured portion. Thereby, various characteristics required for the flexible tube for an endoscope are further improved.

(11) The flexible tube for an endoscope according to any one of the above (1) to (10), wherein the outer skin is coated on an outer periphery of the core material by extrusion molding. Thereby, a flexible tube for an endoscope can be manufactured with good productivity and preferably.

[0029]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a flexible tube for an endoscope according to the present invention will be described in detail based on a preferred embodiment shown in the accompanying drawings.

FIG. 1 is an overall view showing an endoscope (electronic endoscope) having an insertion portion flexible tube to which the flexible tube for an endoscope of the present invention is applied. Hereinafter, the right side in FIG. 1 will be described as “distal end” and the left side as “base end”.

The endoscope 4 shown in FIG. 1 is provided at an insertion portion 5 to be inserted into a body cavity, and an operation portion 41 provided at a base end of the insertion portion 5 and operated by the operator to operate the endoscope 4 as a whole. And a flexible connection section 44 connected to the operation section 41.

The portion of the insertion portion 5 excluding the portion near the tip (the curved portion 52 and the foremost portion 53) is a flexible (elastic) insertion portion flexible tube (endoscope flexible tube). 10. As will be described in detail later, the insertion portion flexible tube 10 has a configuration in which a core material having a hollow portion 24 in which the outer periphery of a spiral tube 21 is covered with a braided tube (braided body) 22 is covered with an outer cover 3. I have.

The proximal end 11 of the insertion section flexible tube 10 is
1 connected. The connecting portion between the insertion portion flexible tube 10 and the operation portion 41 is provided with a buckling member 43 so as to cover the outer periphery thereof.
Is provided.

A bending portion 52 is connected to the distal end 12 of the flexible tube 10. By operating the operation knob 42 provided on the operation section 41, the bending section 52 is pulled in a wire (not shown) disposed in the insertion section flexible tube 10, and bends in four directions. Thereby, the bending portion 52
The bending direction can be freely remotely controlled from the operation unit 41.

At the tip of the curved portion 52, a foremost portion 53 is provided. In the foremost part 53, an objective lens 46,
A light guide tip 47, a forceps channel 48, and an air / water supply port 49 are provided.

One end of the connecting portion flexible tube 44 is connected to the operating portion 41, and the other end is connected to an endoscope processor (not shown) containing a light source. The light emitted from the light source device is connected to the inside of the connection portion flexible tube 44, the inside of the operation portion 41,
A light guide (not shown) using an optical fiber bundle continuously disposed in the insertion portion flexible tube 10 and the bending portion 52.
Illuminates the observation site from the foremost end 53 and illuminates it.

The reflected light (subject image) from the observation site illuminated by the illumination light passes through the objective lens 46 provided in the foremost portion 53 and passes through an image pickup device (see FIG. (Not shown) and converted into an electric signal.
The electric signal of the subject image is supplied to the insertion section flexible tube 10 and the operation section 4.
1. By a transmission cable continuously arranged in the connecting portion flexible tube 44, it is guided to an endoscope connector portion (not shown) provided at the end of the connecting portion flexible tube 44.

The endoscope connector section is connected to the endoscope processor, and the electric signal of the subject image is subjected to image signal processing by the endoscope processor to output a video signal. Observed by an image monitor connected to the processor.

Although the configuration of the endoscope 4 has been described above, the flexible tube for an endoscope of the present invention is not limited to an electronic endoscope.
It goes without saying that the present invention can be applied to a flexible tube for an endoscope of a fiberscope.

FIG. 2 is a longitudinal sectional view showing a first embodiment of an insertion portion flexible tube to which the flexible tube for an endoscope of the present invention is applied, and FIG.
Is a half longitudinal sectional view showing an enlarged view of a portion B in FIG. 2, and FIG.
FIG. 4 is a diagram illustrating a state where the endoscope 4 is lifted while holding the operation unit 41. 2 and 3, the left side is the proximal end 11 side (hand side) and the right side is the distal end 12 side. FIG. 2 is a diagram schematically showing each part in a simplified manner, and in a reduced longitudinal direction.

The flexible tube 10 shown in FIGS.
Has a core material 2 having a hollow portion 24 and an outer skin 3 covering the outer periphery thereof. In the hollow portion 24, for example, a built-in component (omitted in the figure) such as an optical fiber, an electric cable, a cable, or a tube can be arranged and inserted.

The core material 2 is a long object composed of a spiral tube 21 and a braided tube (braided body) 22 covering the outer periphery of the spiral tube 21. The core member 2 has an effect of reinforcing the insertion portion flexible tube 10. In particular, by combining the spiral tube 21 and the mesh tube 22, the flexible insertion tube 10 can secure sufficient mechanical strength. Although illustration is omitted,
The core member 2 can obtain higher mechanical strength by providing the helical tube 21 in two or three times.

The spiral tube 21 is formed by spirally winding a belt-like material with a uniform diameter at an interval 25. As a material constituting the belt-like material, for example, stainless steel, a copper alloy, or the like is preferably used.

The braided tube 22 is formed by braiding a plurality of metal or non-metallic thin wires 23 arranged. As a material constituting the fine wire 23, for example, stainless steel, a copper alloy, or the like is preferably used. Also, the mesh tube 22
May be coated with a synthetic resin (not shown) on at least one of the fine wires 23 forming the pattern.

On the outer periphery of the braided tube 22, a braided thin wire 2
A gap 26 is formed by the third stitch. The gap 26 becomes a concave portion at a position overlapping the outer periphery of the spiral tube 21, and a hollow portion 24 at a position overlapping the space 25 of the spiral tube 21.
And a large number of holes and recesses are formed on the outer periphery of the core material 2.

The outer periphery of the core material 2 is covered with an outer skin 3. The outer cover 3 has a multi-layer laminated structure including a laminate having an inner layer 31 and an outer layer 32.

The inner layer 31 and the outer layer 32 of the outer cover 3 are preferably made of materials having different physical properties or chemical properties (hereinafter, these are collectively referred to as “physical properties”). . Physical properties include, for example, stiffness (flexibility), hardness, elongation, tensile strength, shear strength,
Examples include the flexural modulus and flexural strength, and the chemical properties include, for example, chemical resistance and weather resistance. In addition,
These are only examples, and the present invention is not limited to these.

The inner layer 31 is formed on the innermost side of the outer skin 3 and is in close contact with the core material 2. The inner layer 31 has substantially uniform physical properties over its entire length.

The thickness of the inner layer 31 is substantially constant along the longitudinal direction. Average thickness of inner layer 31 (projection 36
Excluding the part. ) Is not particularly limited, but is usually
It is preferably 0.05 to 0.8 mm, and 0.05 to 0.8 mm.
More preferably, it is 0.4 mm.

On the inner peripheral surface of the inner layer 31, a number of protrusions (anchors) 36 projecting toward the inner peripheral side are formed continuously from the inner layer 31. Each protruding portion 36 enters each of a large number of holes and concave portions formed on the outer periphery of the core material 2. The tip of the protrusion 36 that has entered the recess is formed until it reaches the outer periphery of the spiral tube 21. The projecting portion 36 that has entered the hole is formed to be longer, and its tip enters the space 25 of the spiral tube 21.

The inner layer 31 is made of a material that can form the protrusion 36 by controlling the size (length), shape, number, and the like of the protrusions 36 to be appropriate. Is preferred.

Since the projecting portion 36 is formed as described above, the projecting portion 36 engages with a large number of holes and concave portions formed on the outer periphery of the core member 2, so that an anchor effect is produced, and The outer skin 3 is securely fixed with respect to. Thereby, since the bonding force between the outer cover 3 and the braided tube 22 is strong, the outer cover 3 is hard to peel off from the braided tube 22 even when used repeatedly.

When at least one of the thin wires 23 forming the mesh tube 22 is coated with a synthetic resin, at least a part of the coated resin (coating layer) is melted to form an inner layer. 31 (bonded).

By forming the constituent material of the inner layer 31 to include a material having excellent compatibility with the synthetic resin coated on the fine wire 23, the coating layer of the fine wire 23 is sufficiently bonded to the inner layer 31.

As described above, the coating layer of the fine wire 23 is
In the case where the outer shell 3 and the core material 2 are bonded together, the bonding strength between the outer skin 3 and the core material 2 is higher. In addition, the insertion portion flexible tube 10 has more excellent durability.

The constituent material of the inner layer 31 is not particularly limited. For example, polyolefin such as polyvinyl chloride, polyethylene, polypropylene, ethylene-vinyl acetate copolymer, polyamide, polyethylene terephthalate (PE)
T), polyesters such as polybutylene terephthalate,
Polyurethane, polystyrene resin, polytetrafluoroethylene, fluorine-based resin such as ethylene-tetrafluoroethylene copolymer, various flexible resins such as polyimide, polyurethane-based elastomer, polyester-based elastomer, polyolefin-based elastomer, polyamide-based One or a combination of two or more of various elastomers such as an elastomer, a polystyrene-based elastomer, a fluorine-based elastomer, a silicone rubber, a fluorine rubber, and a latex rubber can be used.

Of these, polyurethane-based elastomers, polyolefin-based elastomers, and polyester-based elastomers are particularly preferable because the formation of the protrusions 36 can be easily controlled.

The outer layer 32 is formed on the outermost side of the outer skin 3. The thickness of the outer layer 32 is, along the longitudinal direction,
It is almost constant. The average thickness of the outer layer 32 is
Although not particularly limited, it is usually preferably from 0.05 to 0.8 mm, more preferably from 0.05 to 0.4 mm.

The outer layer 32 includes a first region 32 on the base end 11 side.
a and a second region 32b on the tip 12 side.
The first region 32a of the outer layer 32 is formed from the base end 11 to the longitudinal center, and the second region 32b is formed from the longitudinal center to the distal end 12. That is, the length of the first region 32a and the length of the second region 32b are both approximately one-half (L / 2) of the total length L of the insertion portion flexible tube 10.
It has become.

A boundary 34 is formed between the first region 32a and the second region 32b of the outer layer 32.

The boundary portion 34 can be formed by mixing the constituent material of the first region 32a and the constituent material of the second region 32b. And it is obtained by gradually changing the mixing ratio along the longitudinal direction (gradient material).

The boundary 34 is made of the same material as the first region 32a, and has a portion whose thickness gradually decreases toward the tip 12 and the same material as the second region 32b.
It can also be formed by overlapping a part whose thickness gradually increases toward 2 (composite material).

Note that without forming such a boundary portion 34,
The first region 32a and the second region 32b may be directly adjacent to each other.

The second region 32b of the outer layer 32 is made of a material having a lower specific gravity than the material forming the first region 32a. Due to this difference in specific gravity, the outer skin 3 has a portion closer to the distal end 12 than the center in the longitudinal direction (the portion where the second region 32b is formed) and a portion closer to the proximal end 11 than the center in the longitudinal direction (the portion where the first region 32a is formed). ) Is lighter than. Due to such a change in the weight of the outer skin 3 along the longitudinal direction, the insertion portion flexible tube 10 has a weight at the distal end 12 side from the longitudinal center and at the proximal end 11 side from the longitudinal center. It is lighter than the weight.

Further, the flexible tube 10 is divided into three equal parts along the longitudinal direction and divided into three parts having a length of L / 3.
When the first part 13, the second part 14, and the third part 15 are respectively arranged from the one part, these parts are arranged from the first part 13 on the base end 11 side to the distal part 12 side. Third
Up to the portion 15.

More specifically, in the first portion 13,
While the entire outer layer 32 of the outer cover 3 is composed of the first region 32a, the second portion 14 is configured such that a part (half) of the outer layer 32 is composed of the second region 32b having a small specific gravity. Therefore, it is lighter than the first portion 13. In addition, the third region 15 is a region where the entire outer layer 32 has a small specific gravity.
2b, it is lighter than the second portion 14.

As described above, the insertion portion flexible tube 10 is
Since the weight of the part on the tip end 12 side is lighter than that of the part on the one side, when the operation part 41 is gripped and the endoscope 4 is lifted, the force (bending moment) applied to the part A near the operation part Is greatly reduced. Thereby, as shown in FIG. 4, compared with the case of the conventional endoscope (the part shown by the two-dot chain line),
The degree of sag of the insertion portion 5 is reduced.

Accordingly, the load on the portion A near the operating portion of the flexible tube 10 is reduced, and even when the flexible tube 10 is repeatedly used, the flexible tube 10 is deformed due to the plastic deformation of the core material 2 or the peeling of the outer cover 3. Can be prevented from being deteriorated or damaged. In addition, built-in components such as optical fibers, cables, electric cables, and tubes can be more reliably protected.

In the present invention, it is sufficient that the flexible tube for an endoscope is configured so that the weight per a certain length decreases from the base end 11 toward the distal end 12. The fixed length may be, for example, 10 cm, and may be L / m (m is any natural number of 2 or more) with respect to the total length L of the flexible tube 10.

The second region 32b of the outer layer 32 may be made of a material having a different composition from that of the first region 32a to reduce its specific gravity, or may be made of a material having the same composition as the first region 32a. The specific gravity may be reduced depending on the difference in the rate.

The outer layer 32 is preferably made of a material having chemical resistance in each region. This allows
Even if washing and disinfection are repeatedly performed, the outer skin 3 is hardly deteriorated, and the outer skin 3 hardens to reduce flexibility, and it is difficult for the outer skin 3 to peel off from the mesh tube 22 due to cracks or the like.

The hardness of the outer layer 32 is set relatively high. Thereby, even if it is repeatedly used, the surface of the outer cover 3 is not easily scratched, and is less likely to cause a crack or the like.

The constituent material of the outer layer 32 is not particularly limited. For example, polyolefin such as polyvinyl chloride, polyethylene, polypropylene, ethylene-vinyl acetate copolymer, polyamide, polyethylene terephthalate (PE)
T), polyesters such as polybutylene terephthalate,
Polyurethane, polystyrene resin, polytetrafluoroethylene, fluorine-based resin such as ethylene-tetrafluoroethylene copolymer, various flexible resins such as polyimide, polyurethane-based elastomer, polyester-based elastomer, polyolefin-based elastomer, polyamide-based One or a combination of two or more of various elastomers such as an elastomer, a polystyrene-based elastomer, a fluorine-based elastomer, a silicone rubber, a fluorine rubber, and a latex rubber can be used.

Among them, in particular, polyolefins such as ethylene-vinyl acetate copolymer, fluorine resins such as polytetrafluoroethylene and ethylene-tetrafluoroethylene copolymer, polyester elastomers, polyolefin elastomers, fluorine elastomers, Silicone rubber and fluoro rubber are preferable because of their excellent chemical resistance.

It is preferable that the average thickness of the entire outer skin 3 (excluding the portion of the protrusion 36) is substantially constant along the longitudinal direction. Thereby, the outer diameter of the flexible tube 10 can be made substantially constant along the longitudinal direction, so that the operability at the time of insertion into the body cavity is improved, and the burden on the patient is reduced.

The average thickness of the entire outer skin 3 (excluding the protruding portion 36) can protect the core material 2 and instruments and the like inserted therethrough from liquids such as body fluids, and can be inserted. There is no particular limitation as long as the flexibility of the flexible tube 10 is not hindered. Usually, it is preferably 0.15 to 0.9 mm, and more preferably 0.3 to 0.8 mm.

The method of manufacturing the flexible tube 10 as described above is not particularly limited. However, the flexible tube 10 can be manufactured continuously by extruding the core 3 onto the core 2 by extrusion molding.

FIG. 5 is a view showing a step of coating the outer skin 3 on the core material 2 by extrusion. Hereinafter, an example of a method for manufacturing the insertion portion flexible tube 10 will be described with reference to FIG.

Core material 2 (spiral tube 21 and mesh tube 22)
Is transported in the longitudinal direction by a transporting means (not shown) in a state where the core metal 60 is inserted through the hollow portion 24, and enters the extruder 6.

Inside the extruder 6, an inner skin material passage 61 and an outer skin material passage 62 are formed. Inner skin material passage 61 and outer skin material passage 62
Are heated and melted, respectively.

The inner skin material 71 is fed into the inner skin material passage 61. On the other hand, the first outer skin material 72a and the second outer skin material 7
2b can be selected and sent by switching the valve 63. By switching the valve 63, the outer layer 32 in which the first region 32a and the second region 32b are arranged in a desired range can be formed.

For example, the second outer shell material 72b is
Is smaller in specific gravity than the outer skin material 72a. Then, at first, the valve 63 is set to a state in which the second outer layer material 72b is fed, and when the outer layer 3 is covered up to the center (or immediately before) in the longitudinal direction of the core material 2, the valve 63 is switched to the first state. The outer skin material 72a is fed. Thereby, the flexible tube 10 of the insertion portion as shown in FIG. 2 is obtained.

The material temperature during extrusion molding is not particularly limited, but is preferably, for example, about 130 to 220 ° C., and more preferably about 165 to 205 ° C. When the material temperature at the time of the extrusion molding is in such a temperature range, the material has excellent moldability to the outer cover 3. Therefore, the uniformity of the thickness of the outer cover 3 is improved.

[0086] The fed outer skin material is extruded from the extrusion opening and is sequentially coated on the outer periphery of the core material 2 moving in the longitudinal direction. As a result, the outer skin 3 composed of the inner layer 31 and the outer layer 32 is covered with the core material 2. The flexible insertion tube 10 exiting the extruder 6 then enters the cooler 70.
In the cooler 70, the outer skin 3 is cooled by water cooling or air cooling, and is fixed to the core material 2. After cooling is completed, the cored bar 60 is removed, and the flexible tube 10 is completed.

As described above, according to the extrusion molding machine having a plurality of extrusion ports, a plurality of layers can be simultaneously extruded, and the laminated body can be coated on the core material 2. Also, by adjusting the supply amount (the supply amount per unit time) of the constituent material of each layer and the moving speed of the core material 2 from each extrusion port,
The thickness of each layer can be adjusted.

The insertion section flexible tube 10 is not limited to the above-described method. For example, after the outer skin 3 is formed in a tube shape in advance, the flexible tube 10 is placed on the core material 2 and tightly fixed by a method such as an adhesive or heating. It may be manufactured by a method or the like.

As described above, in the present embodiment, the outer cover 3 that is easily adjusted among the constituent members of the flexible tube 10 of the insertion portion.
The insertion portion flexible tube 10 is configured such that the distal end 12 side is lighter than the base end 11 side by changing the weight along the longitudinal direction. Thereby, the insertion portion flexible tube 10 is
It can be easily manufactured.

FIG. 6 is a longitudinal sectional view showing a second embodiment of an insertion portion flexible tube to which the flexible tube for an endoscope of the present invention is applied, and FIG.
FIG. 7 is a half longitudinal sectional view showing a portion C in FIG. 6 in an enlarged manner. 6 and 7, the left side is the proximal end 11 side (hand side), and the right side is the distal end 12 side. FIG. 6 is a diagram schematically showing each part in a simplified manner and in a reduced longitudinal direction.

Hereinafter, a second embodiment of the flexible tube for an endoscope according to the present invention will be described with reference to these drawings. Will not be described.

The flexible insertion tube 20 shown in these figures is the same as the flexible flexible tube 10 of the first embodiment except that the configuration of the outer cover 3 is different.

The outer skin 3 of the flexible tube 20 is inserted into the inner layer 31.
And an outer layer 32 and an intermediate layer 33 located therebetween.
The thickness of each layer is substantially constant along the longitudinal direction.

The inner layer 31 of the outer cover 3 has the same configuration as the inner layer 31 of the flexible tube 10 of the first embodiment.

The outer layer 32 of the outer cover 3 is formed of a single region over the entire length. The constituent material, average thickness, and the like of the outer layer 32 are the same as those of the outer layer 3
2 can be performed as described above.

The intermediate layer 33 of the outer cover 3 includes a first region 33a located on the proximal end 11 side, a third region 33c located on the distal end 12 side, and a second region 33b located therebetween.
And three regions. The lengths of these regions are substantially the same (L / 3).

The intermediate layer 33 is located between the first region 33a and the second region 33b, and between the second region 33b and the third region 3b.
A boundary portion 35 similar to the boundary portion 34 is formed between the boundary portion 3c.

The second region 33b of the intermediate layer 33 is made of a material having a lower specific gravity than the first region 33a, and the third region 33c is made of a material having a lower specific gravity than the second region 33b. ing. Thereby, the weight of the outer skin 3 is
The weight of the three portions where each region of the intermediate layer 33 is formed is
From the portion on the base end 11 side (the portion where the first region 33a is formed) to the portion on the distal end 12 side (the portion where the third region 33c is formed), the weight is gradually reduced. Due to such a change in the weight of the outer cover 3 along the longitudinal direction, the insertion portion flexible tube 10 has a weight at the distal end 12 side from the longitudinal center and at the proximal end 11 side from the longitudinal center. Is lighter.

Further, the insertion portion flexible tube 20 (total length L) is divided into five equal parts along the longitudinal direction, divided into five parts having a length L / 5, Part 1 of 1
3, the second part 14, the third part 15, the fourth part 1
6 and the fifth part 17, these parts are from the first part 13 on the base end 11 side to the fifth part 1 on the tip end 12 side.
Up to 7, the weight is reduced in order.

More specifically, the first portion 13 has the entire intermediate layer 33 of the outer skin 3 formed of the first region 33a, whereas the second portion 14 has the Since the portion is constituted by the second region 33b, it is lighter than the first portion 13. In addition, the third portion 15 includes an intermediate layer 33.
Is composed of the second region 33b,
Is lighter than the part 14. Further, the fourth portion 16 is lighter than the third portion 15 because part of the intermediate layer 33 is constituted by the third region 33c. And the fifth part 17
Is lighter than the fourth portion 16 because the entirety of the intermediate layer 33 is constituted by the third region 33c.

With such a configuration, the insertion portion flexible tube 20
The weight of each part along the longitudinal direction increases from the proximal end 11 to the distal end 12 of the flexible tube 1 of the first embodiment.
It is lighter in multiple stages than 0. For this reason,
When the endoscope 4 is lifted by gripping the operation section 41, the force (bending moment) applied to the portion A near the operation section is further reduced. Therefore, the load on the portion A near the operation section of the insertion section flexible tube 20 is smaller, and deterioration and breakage of the insertion section flexible tube 20 can be more effectively prevented.

Further, when the insertion portion flexible tube 20 is divided into four equal parts along the longitudinal direction into four portions having a length L / 4,
The weight of each of these portions is reduced in order from the portion on the proximal end 11 side to the portion on the distal end 12 side.

Further, according to the present invention, the flexible tube for an endoscope is made to have an equal length n (n is 3 to 1) along the longitudinal direction.
When divided into n equal parts (any natural number of 0) parts, the weight of each part is reduced in order from the part on the base end 11 side to the part on the tip end 12 side. Just do it. For example, the intermediate layer 33 is formed along the longitudinal direction by 6
Has two regions, and the specific gravity of each of those regions is
If it is decided to decrease in order toward the distal end 12, when divided into ten equal parts along the longitudinal direction, each of those parts is changed from the part on the proximal end 11 side to the part on the distal end 12 side.
The weight can be reduced in order. Thereby, the deterioration and breakage of the portion A near the operation portion can be more effectively prevented.

The intermediate layer 33 is preferably a layer that is more flexible (excellent in elasticity) than the outer layer 32. Thus, the intermediate layer 33 exhibits a cushion function between the inner layer 31 and the outer layer 32. The intermediate layer 33 is preferably a layer that is more flexible than the inner layer 31.

The cushion function of the intermediate layer 33 will be described in more detail. When the flexible tube 20 is bent, the elasticity of the intermediate layer 33 is excellent, so that the deformed intermediate layer 33 exerts a strong restoring force. Since the intermediate layer 33 is sandwiched between the inner layer 31 and the outer layer 32 having relatively high hardness, the restoring force of the intermediate layer 33 is efficiently transmitted to the inner layer 31 and the outer layer 32. Therefore, almost all of the restoring force of the intermediate layer 33 is used for restoring the bending of the insertion portion flexible tube 20. Therefore, with such a configuration, the insertion portion flexible tube 20 has excellent elasticity.

The constituent material of the intermediate layer 33 is not particularly limited. For example, polyolefin such as polyvinyl chloride, polyethylene, polypropylene, ethylene-vinyl acetate copolymer, polyamide, polyethylene terephthalate (P
ET), polyesters such as polybutylene terephthalate, polyurethane, polystyrene resins, polytetrafluoroethylene, fluorine resins such as ethylene-tetrafluoroethylene copolymer, various kinds of flexible resins such as polyimides, polyurethane elastomers, Among various elastomers such as polyester elastomer, polyolefin elastomer, polyamide elastomer, polystyrene elastomer, fluorine elastomer, silicone rubber, fluorine rubber, latex rubber, etc.
Species or a combination of two or more can be used.

Among them, polyurethane elastomers, polyolefin elastomers, and polyester elastomers having low hardness are particularly preferable because of their excellent flexibility (elasticity).

In the present embodiment, the intermediate layer 33 has a single-layer configuration, but may have a configuration in which two or more intermediate layers 33 are formed.

The average thickness of the intermediate layer 33 is not particularly limited, but is usually preferably from 0.05 to 0.8 mm, more preferably from 0.05 to 0.4 mm.

In this embodiment, the inner layer 31 and the outer layer 32
Are formed as a single region over the entire length of the insertion portion flexible tube 20. Therefore, the characteristics of the inner layer 31 and the outer layer 32 do not differ between the portions of the laminate, and are provided over the entire length of the laminate. Therefore, for example, the adhesiveness of the inner layer 31 to the core material 2 and the chemical resistance of the outer layer 32 can be improved over the entire length of the laminate. As described above, in the flexible tube 20 of the insertion portion, while the characteristics such as durability and chemical resistance are excellent over the entire length, the change in weight between the distal end 12 and the proximal end 11 as described above. Is obtained.

In this embodiment, since the boundary portion 35 is not exposed on the outer peripheral surface, it is easy to smooth the outer peripheral surface.

Although the flexible tube for an endoscope of the present invention has been described above, the present invention is not limited to this.
Each component constituting the flexible tube for an endoscope can be replaced with an arbitrary component having a similar function.

For example, the layer having a plurality of regions having different specific gravities is not limited to the outer layer 32 and the intermediate layer 33, but may be the inner layer 31. Two or more layers have a plurality of regions having different specific gravities. Is also good.

The outer skin 3 may be composed of a single layer. Further, in order to change the weight of the outer cover 3 along the longitudinal direction, the present invention is not limited to the configuration shown in the figure, but may be configured as follows, for example.

In the case where the outer cover 3 is composed of a single layer or a plurality of layers (laminate), at least one of the layers has its thickness gradually or continuously reduced from the base end to the end.

When the outer cover 3 is formed of a laminate, the number of layers is changed along the longitudinal direction. For example, the base end has three layers, the middle part has two layers, and the front end has a single layer.

Further, instead of or in addition to the change in the weight of the outer cover 3 along the longitudinal direction, the change in the weight of the core material 2 along the longitudinal direction causes the weight of the flexible tube for an endoscope to change. The length may be varied along the longitudinal direction. For example, with the following configuration, a change in the weight of the core 2 along the longitudinal direction can be obtained.

The helical pitch of the helical tube 21 is increased continuously or stepwise toward the tip.

The width and thickness of the belt-like material forming the spiral tube 21 are gradually reduced continuously or stepwise toward the tip end.

In the case where the mesh tube 22 is formed by blending a thin metal wire having a large specific gravity and a non-metal thin wire having a small specific gravity, the blending ratio of the non-metal thin wire is increased toward the distal end.

The density of the braid of the braided tube 22 is reduced toward the distal end. Or, on the tip side,
The mesh tube 22 is omitted.

Needless to say, the above-described configuration may be a combination of a plurality of configurations including those other than the above.

The core material is not limited to a combination of a spiral tube and a mesh tube as long as it has sufficient mechanical strength to reinforce the flexible tube for an endoscope. For example, a tube having a tube instead of a spiral tube, or a tube having only one of a spiral tube and a mesh tube may be used.

Further, the present invention is not limited to the flexible tube at the insertion portion.
The present invention can also be applied to other connection pipes such as a connection section flexible pipe connected to the operation section.

[0123]

As described above, according to the present invention, the weight of the distal end portion is lighter than that of the proximal end portion. In addition, the burden on the portion A near the operation portion of the flexible tube for an endoscope is reduced, and the deterioration and breakage of the portion A near the operation portion of the flexible tube for an endoscope can be effectively prevented. .

When the weight of the flexible tube for an endoscope is changed along the longitudinal direction by changing the weight of the outer skin along the longitudinal direction, the above-mentioned effect can be achieved with a simple structure. And can be manufactured easily and inexpensively.

Further, at least one of the layers constituting the outer shell has a plurality of regions along the longitudinal direction, and the specific gravity of each of the regions is gradually reduced from the region on the base end side to the region on the distal end side. In such a case, the above effects can be achieved with a minimum structural change, and various characteristics required for the flexible tube for an endoscope can be improved.

[Brief description of the drawings]

FIG. 1 is a view showing an electronic endoscope having an insertion portion flexible tube to which the endoscope flexible tube of the present invention is applied.

FIG. 2 is a longitudinal sectional view showing a first embodiment of an insertion portion flexible tube to which the flexible tube for an endoscope of the present invention is applied.

FIG. 3 is a semi-longitudinal sectional view showing a portion B in FIG. 2 in an enlarged manner.

FIG. 4 is a diagram showing a state in which the fiber endoscope shown in FIG. 1 is gripped by an operation unit and lifted.

FIG. 5 is a view showing a step of manufacturing the flexible tube of the insertion portion shown in FIG. 2;

FIG. 6 is a longitudinal sectional view showing a second embodiment of an insertion portion flexible tube to which the endoscope flexible tube of the present invention is applied.

7 is a half longitudinal sectional view showing a portion C in FIG. 6 in an enlarged manner.

FIG. 8 is a diagram showing a state in which a conventional medical endoscope is gripped and lifted by an operation unit.

FIG. 9 is an enlarged perspective view of the distal end of the insertion section of the endoscope shown in FIG. 8;

[Explanation of symbols]

 10, 20 insertion part flexible tube 11 base end 12 tip 13 first part 14 second part 15 third part 16 fourth part 17 fifth part 2 core material 21 spiral tube 22 mesh tube 23 fine wire 24 Hollow part 25 Interval 26 Gap 3 Outer skin 31 Inner layer 32 Outer layer 32a First area 32b Second area 33 Intermediate layer 33a First area 33b Second area 33c Third area 34,35 Boundary part 36 Projection 4 Inside Endoscope 41 Operation part 42 Operation knob 43 Bend-preventing member 44 Connection part flexible tube 46 Objective lens 47 Light guide tip part 48 Forceps channel 49 Air supply / water supply port 5 Insertion part 51 Insertion part flexible tube 51 a Tip 51 b Base end 52 Bending part 53 Leading edge part 6 Extrusion molding machine 61 Inner layer outer material passage 62 Outer layer outer material passage 63 Valve 71 Inner layer outer material 72a Outside first outer layer Site material 72b second outer skin material 50 endoscope 60 metal core 70 around cooler A manipulation unit

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Shinji Hayakawa 2-36-9 Maenocho, Itabashi-ku, Tokyo Asahi Gaku Kogyo Co., Ltd. (72) Inventor Yuhisa Abe 2-36, Maenocho, Itabashi-ku, Tokyo 9 Asahi Gaku Kogyo Co., Ltd. F-term (reference) 4C061 DD03 FF26 JJ03 JJ06

Claims (11)

[Claims] 1. A flexible tube for an endoscope having a core material having a hollow portion and an outer skin coated on the outer periphery of the core material, wherein the weight of a portion on the distal end side from the center in the longitudinal direction is provided. A flexible tube for an endoscope, wherein the flexible tube is configured to be lighter than the weight of a portion closer to the base end than the center in the longitudinal direction. 2. The endoscope flexible tube is equally divided into n (n is any natural number from 3 to 10) portions of equal length along the longitudinal direction. 2. The flexible tube for an endoscope according to claim 1, wherein the weight of each of the portions is sequentially reduced from a portion on the proximal end side to a portion on the distal end side. 3. 3. A flexible tube for an endoscope having a core material having a hollow portion and an outer skin coated on an outer periphery of the core material, wherein the flexible tube for an endoscope has a predetermined length. A flexible tube for an endoscope, wherein the weight of the flexible tube is configured to decrease from its base end toward its distal end. 4. The endoscope according to claim 1, wherein the change in the weight of the outer skin along the longitudinal direction contributes to the change in the weight of the flexible tube for the endoscope along the longitudinal direction. The flexible tube for an endoscope according to the above. 5. The flexible tube for an endoscope according to claim 1, wherein the outer skin has a single layer or a multilayer structure. 6. The length of at least one of the layers constituting the outer shell and / or the material of the outer shell are changed along the longitudinal direction, so that the weight per fixed length of the outer shell is changed along the longitudinal direction. 6. The flexible tube for an endoscope according to claim 5, wherein the flexible tube is changed. 7. At least one of the layers constituting the outer skin has a plurality of regions along a longitudinal direction, and the specific gravity of the material constituting each region is from a region on the proximal side to a region on the distal side. The flexible tube for an endoscope according to claim 5, wherein the flexible tube is configured to decrease in order. 8. The flexible tube for an endoscope according to claim 1, wherein a thickness of the outer skin is substantially constant along a longitudinal direction. 9. The core material includes: a spiral tube formed by spirally winding a strip-shaped material; and a braided body formed by braiding a thin wire, which is coated on the outer periphery of the spiral tube and braided. 9. The flexible tube for an endoscope according to any one of 1 to 8. 10. The outer shell is made of a material containing at least one selected from the group consisting of a polyurethane elastomer, a polyester elastomer, a polyolefin elastomer, a polystyrene elastomer, a polyamide elastomer, a fluoroelastomer and a fluoroelastomer. The flexible tube for an endoscope according to any one of claims 1 to 9, further comprising: 11. The core according to claim 1, wherein the outer skin is coated on an outer periphery of the core material by extrusion molding.
The flexible tube for an endoscope according to any one of the above.