JPH08122655A - Curving flexible pipe - Google Patents

Abstract

PURPOSE: To eliminate the need for assembly, to facilitate the formation and to assure the strength over the entire part of a curving pipe by providing a curving flexible pipe with a tubular body consisting of a metallic material which induces thermoelastic martensite transformation and providing a part of this tubular body with a thin part which is made thin and easily deformable. CONSTITUTION: A curving part 4 of an insertion part is provided with a curving pipe 13. This curving pipe 13 is formed out of a metallic material which induces the thermoelastic martensite transformation, for example, an NiTi-based alloy which induces stress-induced martensite transformation, and of which cylindrical tubular body 14 is formed from it. further, the output peripheral surface of the tubular body 14 is provided with plural annular recessed parts 15 at specified intervals in an axial direction. Thin parts 16 formed thin by the parts of the respective recessed parts 15 are formed on the tubular body 14. Then, the regions of the thick parts between the adjacent thin parts 16 and 16 of the tubular body 14 are held in an approximately non-deformed state and the regions of the thin parts 16 of the tubular body 14 which are weaker in strength than the parts of these thick parts are mainly deformed at the time of curving of the curving pipe 13.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a bending flexible tube used for a movable part such as an endoscope or a manipulator.

[0002]

2. Description of the Related Art Generally, a flexible endoscope has an insertion portion provided at its distal end with a bending portion capable of performing a bending operation. Then, the bending operation of the bending portion can be remotely operated by an operation knob or the like arranged on the operation portion on the proximal side of the insertion portion of the endoscope.

Further, in this type of endoscope, a bending tube which is manufactured by rotatably connecting a cylindrical part to the bending portion on the distal end side of the insertion portion is usually arranged. Then, the operation wire is pulled by the operation of the operation section on the proximal side to bend the bending tube.

Further, for example, in Japanese Unexamined Patent Publication No. 4-61840, a bending tube formed by cutting out a shape memory alloy (SMA) pipe is arranged in the bending portion on the distal end side of an insertion portion of an endoscope. It is shown that the joint portion at the time of bending is formed by the remaining portion of the notch portion.

[0005]

In the conventional structure described above, when a cylindrical part is rotatably connected to form the bending tube of the bending portion, the number of components of the bending tube increases, so There is a problem that the assembly of the pipe becomes complicated.

Further, in the case of Japanese Patent Application Laid-Open No. 4-61840, since stress is locally concentrated on the cutout portion of the SMA pipe forming the bending tube during bending operation of the bending portion, the strength of the entire bending tube is reduced. There is a problem that is easy to do. Therefore, there is a problem that it is difficult to secure the strength and durability of the entire curved tube.

The present invention has been made in view of the above circumstances, and an object thereof is a bendable flexible tube which can be easily formed without the need of assembling and can sufficiently secure the strength of the entire bendable tube. To provide.

[0008]

According to the present invention, a tubular body made of a metal material which undergoes thermoelastic martensitic transformation is provided, and a thin wall portion is provided at a part of the tubular body so as to be easily deformed. It is a thing.

[0009]

In the bending operation of the tubular body, the region of the thin portion is mainly deformed to perform the bending operation, and sufficient strength is maintained in the thick portion other than the thin portion.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of the present invention will be described below with reference to FIGS.
Will be described with reference to. FIG. 2 shows a schematic configuration of the entire medical endoscope 1. This medical endoscope 1 has an insertion portion 2
And an operating section 3, and a bending section 4 is provided near the tip of the insertion section 2. Further, the operation portion 3 is provided with an operation knob 5 of the bending portion 4. Then, the bending operation of the bending portion 4 is remotely operated by the operation knob 5.

Further, an observation optical system and an illumination optical system are arranged on the distal end surface 6 of the insertion portion 2. In addition, a signal line extending from the image pickup device of the observation optical system and a light guide fiber connected to the illumination optical system are arranged in the insertion portion 2.

The operation section 3 has a universal cord 7
The base ends of are connected. This universal code 7
A connector 8 is connected to the tip of the. The connector 8 is detachably connected to the light source device 9. Then, the incident end side of the light guide fiber passes through the inside of the universal cord 7 from the operation part 3, and is connected to the light source device 9 via the connector 8.

Further, the other end side of the signal line extending from the image pickup device passes from the operation section 3 through the universal cord 7, and further through the connection cord 10 connected to the connector 8, the camera control unit (CCU). 11 is connected. Reference numeral 12 is a connector connected to the tip of the connection cord 10, and the connection cord 10 is detachably connected to the camera control unit via the connector 12.

1 (A) and 1 (B) show the bending portion 4 of the insertion portion 2. A bending tube 13 is provided in the bending portion 4.
Is provided. The curved tube 13 has a cylindrical tube body 14 formed of a metal material that causes thermoelastic martensitic transformation, for example, a NiTi-based alloy that causes stress-induced martensitic transformation.

Further, a plurality of ring-shaped concave portions 15 are provided on the outer peripheral surface of the tubular body 14 at regular intervals in the axial direction. The tube body 14 is formed with a thin portion 16 whose wall thickness is thin due to these concave portions 15.

Further, four operating wires 17 are arranged inside the bending tube 13. As shown in FIG. 1A, the distal ends of these operation wires 17 are arranged at 90 ° intervals on the inner peripheral surface of the distal end of the bending tube 13, and are fixed via wire fixing members 18, respectively.

Further, as shown in FIG. 1B, a guide member 19 for the operation wire 17 is provided on the inner peripheral surface of the rear end portion of the bending tube 13.
Has been fixed. The guide members 19 are provided at positions corresponding to the wire fixing members 18, respectively. Then, each operation wire 17 is inserted into the guide member 19 to prevent the wires 17 from being entangled with each other.

The proximal end side of each operation wire 17 is guided to the operation section 3 side through the inside of the insertion section 2 and is connected to a pulley (not shown) which is rotated by the operation knob 5. Then, the bending portion 4 is bent by turning the operation knob 5 and pulling an arbitrary operation wire 17.

Next, the procedure for manufacturing the bending tube 13 of the bending portion 4 will be described with reference to FIG. First, FIG. 3 (A1),
As shown in (A2), the NiTi-based superelastic pipe 2 having a diameter of 1 mm and a thickness of 0.2 mm, which is a tubular body material of the curved pipe 13.
Positive resist 2 used for manufacturing integrated circuits on the outer peripheral surface of 0
1 (etch-resistant coating) is applied. Then, while rotating the pipe 20 about its central axis, the pipe 2
The positive resist 21 on the outer peripheral surface of 0 is irradiated with laser light and a plurality of (the same number as the thin portion 16) exposure regions 2 are provided at appropriate intervals (corresponding to the interval between the adjacent thin portions 16).
Form 2

Further, after the exposure by the laser beam, the positive resist 21 in the exposed area 22 is removed by developing the exposed portion to expose the surface of the superelastic pipe 20 as shown in FIGS. 3B1 and 3B2. Exposed surface 23 of pipe surface
Is formed.

Next, this is immersed in a mixed solution of fluorine and nitric acid to etch the pipe surface exposed region 23 where the superelastic pipe 20 is exposed. By this etching, FIG.
As shown in (C1) and (C2), a ring-shaped concave portion 15 is formed on the outer peripheral surface of the superelastic pipe 20, and this portion forms a thin region of the superelastic pipe 20, for example, a 0.05 mm thick portion. The thin portion 16 is formed. At the time of this etching, the opening of the pipe 20 is sealed so that the mixed solution for etching does not enter the inner cavity of the pipe 20.

After that, the remaining positive resist 21 is removed by oxygen plasma. As a result, FIG.
1) and (D2), a plurality of ring-shaped thin portions 16 are provided on the outer peripheral surface of the tubular body 14 at regular intervals in the axial direction, and the thin portion 16 and the wall thickness between the adjacent thin portions 16 and 16 are increased. Part 22
A curved tube 13 is formed in which and are alternately arranged along the axial direction.

Next, the operation of the above configuration will be described.
Here, when the bending portion 4 of the insertion portion 2 is bent, by operating the operation knob 5 of the operation portion 3, the operation wire 5 is moved in a direction corresponding to the operation direction of the operation knob 5 among the four operation wires 17. Any one of the arranged operation wires 17 is pulled toward the hand side.

As the operation wire 17 is pulled, the bending tube 13 of the bending portion 4 is bent in a substantially arc shape. For example, in FIGS. 1A and 1B, by pulling the operation wire 17 at the upper end position, the bending tube 13 of the bending portion 4 bends in a substantially arc shape in the arrow direction in FIG. 1B. To do. When the bending tube 13 is bent, the region of the thick portion 22 between the adjacent thin portions 16 of the tubular body 14 is held in a state where it is not substantially deformed, and the strength is weaker than that of the thick portion 22. The region of the thin portion 16 of the tubular body 14 is mainly deformed.

Therefore, the following effects can be obtained with the above-mentioned structure. That is, since the plurality of thin-walled portions 16 that easily bend and the thick-walled portions 22 between the adjacent thin-walled portions 16 and 16 are alternately arranged in the bending tube 13 along the axial direction,
The thick portion 22 of the bending tube 13 can maintain the strength to protect the internal components from external force. Further, when the bending tube 13 is bent, by deforming the portion of the thin portion 16 of the tube body 14, it is possible to maintain a state in which it is easily bent and deformed. Therefore, it is possible to maintain the strength of protecting the built-in object from the external force at the thick portion 22 and at the same time, to easily bend and deform the thin portion 16 at the same time.

Further, since the tubular body 14 of the bending tube 13 is formed of a NiTi superelastic pipe, it exhibits elasticity superior to that of general metals such as stainless steel by one digit or more. Therefore, even with the bending tube 13 having the above structure, a sufficient bending angle can be obtained when the bending tube 13 is bent.

Further, since the tube body 14 of the bending tube 13 is formed with a plurality of thin portions 16 which are easily bent by the photo-etching technique on the outer peripheral surface of the superelastic pipe 20, a plurality of thin portions 16 are formed. Adjacent thin parts 16, 16
It is possible to easily form the curved tube 13 in which the thick portions 22 in between are alternately arranged along the axial direction. Therefore, it is not necessary to assemble a plurality of constituent parts as in the case of assembling a plurality of constituent parts to form a curved tube.
3 can be easily formed.

Further, since the tube body 14 of the bending tube 13 is not formed with the cutout portion of the pipe as in the prior art (Japanese Patent Laid-Open No. 4-61840), the strength of the bending tube 13 as a whole is increased and repeated. The durability against movement can also be improved.

FIG. 4 shows a second embodiment of the present invention. This is a modification of the configuration of the bending portion 4 from the first embodiment. That is, although the bending portion 4 having the structure using the operation wire 17 is shown in the first embodiment,
In this embodiment, as shown in FIGS. 4D1 and 4D2, a bending actuator made of a shape memory alloy pipe is formed by the tubular body 32 of the bending tube 31 of the bending portion 4 itself.

Here, the tube body 32 of the bending tube 31 is formed of a NiTi type shape memory alloy pipe which has undergone shape memory processing in advance. The NiTi-based shape memory alloy pipe of the tubular body 32 is called a bidirectional shape memory alloy, and bends in a certain direction when heated up to the transformation temperature, and bends in an inverted direction when cooled below the transformation temperature. Is heat treated.

Further, a plurality of ring-shaped recessed portions 33 are provided on the outer peripheral surface of the tubular body 32 at regular intervals in the axial direction. Further, a strip-shaped recess 34 is formed on the outer peripheral surface of the pipe 32 so as to extend substantially linearly in the direction orthogonal to the ring-shaped recess 33, that is, in the axial direction of the pipe 32. And the tubular body 3
2, the thin-walled portion 3 is thinned by the ring-shaped recess 33 and the band-shaped recess 34.
5 is formed.

A conductive material such as the platinum layer 3 is formed on the outer peripheral surface of the thick portion 36 of the tubular body 32 other than the thin portion 35.
7 is formed by a method such as plating. Furthermore, the tubular body 3
Insulation coating of the lead wire 3 in the strip-shaped recess 34 of 2
8 are provided. The tip of the lead wire 38 is welded and electrically connected to the tip of the tubular body 32 of the shape memory alloy pipe. The base end of the lead wire 38 is connected to an external energizing device (not shown).

Next, a procedure for manufacturing the bending tube 31 of the bending portion 4 will be described with reference to FIG. First, FIG. 4 (A1),
As shown in (A2), the outer diameter dimension 1 which has undergone shape memory processing in advance
A platinum layer 37 is formed on a tubular body 32 made of a NiTi-based shape memory alloy pipe having a thickness of 0.2 mm and a thickness of 0.2 mm by plating or the like.

Thereafter, a positive resist 39 used for manufacturing an integrated circuit or the like is applied to the outer peripheral surface of the tubular body 32. Then, while rotating the pipe of the pipe 32 around its central axis, the positive resist 39 on the outer peripheral surface of the pipe 32 is irradiated with laser light to obtain an appropriate space (adjacent ring-shaped recesses 33, 3).
A plurality of (the same number as the ring-shaped recessed portion 33) exposure regions 40 are formed at intervals (corresponding to the interval between 3), and a belt-shaped exposure region 41 that extends substantially linearly in the axial direction of the tubular body 32. To form.

Further, after the exposure by the laser beam, the positive resist 39 in the exposed areas 40 and 41 is removed by developing the exposed surface, and the surface of the platinum layer 37 is exposed as shown in FIGS. 4 (B1) and 4 (B2). Exposed area 4 of exposed platinum layer 37
2, 43 are formed.

Next, ion milling is performed while rotating the tube 32 to expose the platinum layer 37 in the exposed regions 42 and 43.
Is exposed to expose the shape memory alloy of the tubular body 32 at that portion.

Subsequently, this is immersed in a mixed solution of fluorine and nitric acid, and the shape memory alloy of the tube 32 in the exposed regions 42 and 43 is etched to a thickness of 0.05 mm. By this etching, as shown in FIGS. 4C1 and 4C2, the ring-shaped recess 33 is formed on the outer peripheral surface of the shape memory alloy of the tubular body 32.
And the band-shaped recess 34 is formed, and this region forms a thin region of the shape memory alloy tubular body 32, for example, a thin portion 35 having a thickness of 0.05 mm. At the time of this etching, the opening of the pipe 32 is sealed so that the mixed liquid for etching does not enter the inner cavity of the pipe 32.

After that, the remaining positive resist 39 is removed by oxygen plasma. As a result, FIG.
As shown in 1) and (D2), a plurality of thin wall portions 35 corresponding to the ring-shaped recessed portions 33 are provided on the outer peripheral surface of the tubular body 32 at regular intervals in the axial direction and are adjacent to the ring-shaped thin wall portion 35. The ring-shaped thin portions 35, and the thick portions 36 in which the platinum layers 37 are stacked between the thin portions 35 are alternately arranged along the axial direction, and the thin portion 35 corresponding to the band-shaped recess 34 is formed. The curved tube 31 is formed.

Further, after the curved tube 31 is formed in this manner, the lead wire 38 is disposed in the band-shaped recess 34 of the tubular body 32 of the curved tube 31, and the tip portion of the lead wire 38 has a shape memory. It is welded and electrically connected to the tip end of the pipe body 32 of the alloy pipe.

Next, the operation of the above configuration will be described.
First, when the bending portion 4 of the insertion portion 2 is operated to be bent, electricity is applied to the tubular body 32 of the shape memory alloy pipe of the bending tube 31 through the lead wire 38. At this time, the thin portion 35 of the pipe 32
Since the shape memory alloy is thin and the low resistance platinum layer 37 is absent in the area (3), the electric resistance becomes significantly larger than that in the other thick area 36.

Therefore, when electricity is applied to the tubular body 32 of the shape memory alloy pipe through the lead wire 38, the band-shaped recess 34 is formed.
The region of the thin portion 35 corresponding to the above is selectively heated, and the bending tube 31 changes to a previously stored arcuate curved shape.

When the bending tube 31 is bent, the adjacent ring-shaped thin wall portions 3 of the tube 32 are bent as in the first embodiment.
The region of the thick portion 36 in which the platinum layer 37 between 5 and 35 is laminated is held in a substantially non-deformed state, and the region of the thin portion 35 of the tubular body 31 whose strength is weaker than that of the thick portion 36 is Mainly transformed.

Therefore, the following effects can be obtained with the above structure. That is, in this embodiment, when the bending tube 31 is bent, the region of the thick portion 36 in which the platinum layer 37 between the adjacent ring-shaped thin portions 35, 35 is laminated in the tubular body 32, as in the first embodiment. Is held in a substantially non-deformed state, and the thin portion 35 of the tubular body 31 whose strength is weaker than that of the thick portion 36 is mainly deformed.
The strength of protecting the internal components from the external force can be maintained at the portion 6 and, at the time of bending the bending tube 31, by deforming the portion of the thin portion 35 of the tube body 31, it is possible to maintain the state of being easily bent and deformed. You can Therefore, as in the first embodiment, while maintaining the strength of protecting the internal components from the external force at the thick portion 36, at the same time, the thin portion 35 can be easily bent and deformed, and the bending tube Three
1 can be easily formed, the strength of the entire bending tube 31 can be increased, and the durability against repeated operations can be improved.

Further, in this embodiment, the tube body 32 of the bending tube 31 is used.
Since the lead wire 38 is provided in the band-shaped recess 34, there is no possibility that the lead wire 38 is provided in a state of being projected to the outside of the tubular body 32. Therefore, the lead wire 38 does not increase the outer dimension of the bending tube 31.

Further, when electricity is applied to the tubular body 32 of the shape memory alloy pipe through the lead wire 38, only the region of the thin portion 35 corresponding to the strip-shaped recess 34 in which the lead wire 38 is disposed. Can be heated quickly,
It is possible to improve the responsiveness when the bending tube 31 is bent.

In the second embodiment, the lead wire 38 is connected only to the distal end portion of the bending tube 31, but the lead wire 38 is provided at a plurality of positions of the bending tube 31. It is also possible to bend the bending tube 31 into a plurality of shapes by selectively and selectively energizing the lead wire 38.

5 to 9 show a third embodiment of the present invention. This is applied to the tubular structure 51 such as a curved portion provided at the tip of the insertion portion of the endoscope. That is, the tubular structure 51 of this embodiment is shown in FIG.
As shown in (A), a large-diameter first bending tube 52 and a small-diameter second bending tube 53 arranged in the first bending tube 52.
Is formed into a double-tube structure including.

Here, the first bending tube 52 and the second bending tube 53 have the same structure as the bending tube 13 of the first embodiment. Further, as shown in FIG. 6, the two curved tubes 52 and 53 are formed so that the width dimension t of the thin portion 16 and the width dimension s of the thick portion 22 are the same. Then, the thin-walled portion 16 and the thick-walled portion 22 of which the thickness is thin are arranged in the tubular structure 51 in a state where the positions of the portions are matched with each other.

Between the two curved tubes 52 and 53, there are eight shape memory alloy pipes 54a as shown in FIG. 5B.
.About.54h are arranged side by side in a substantially circumferential shape. The bent shapes of the shape memory alloy pipes 54a to 54h are stored in advance.

Further, each shape memory alloy pipe 5
A wire-shaped heater 55, which is a heating means, is arranged on the outer peripheral surfaces of 4a to 54h. Here, the heater 55 is shown in FIG.
As shown in (A), it is folded back at a substantially central portion, and the folded back portion is fixed to the outer peripheral surface of the tip end portion of each shape memory alloy pipe 54a to 54h.

In addition to the arrangement of the heater 55 shown in FIG. 7A, a rod-shaped heater 56 may be provided inside each of the shape memory alloy pipes 54a to 54h as shown in FIG. 7B. Alternatively, as shown in FIG. 7C, the wire-shaped heater 5 is provided on the outer peripheral surface of each shape memory alloy pipe 54a to 54h.
7 may be wound around.

Furthermore, each shape memory alloy pipe 54a-5
The memory direction of the bending shape of 4h is, for example, stored outwardly as indicated by an arrow in FIG. 8 (A), or inwardly stored as indicated by an arrow in FIG. 8 (B). There is.

In the tubular structure 51, a light guide cable 58 for illuminating means and an image guide cable 59 for observing means are provided as built-in components. Here, the light guide cable 58 is a shape memory alloy pipe 54a,
The image guide cable 59 is provided inside 54c, 54e, and 54g, and is provided inside the second bending tube 53.

Further, the other vacant shape memory alloy pipes 54b, 54d, 54f, 54h are used as treatment instrument insertion channels for inserting treatment instruments such as forceps to perform treatment.

Next, the operation of the above configuration will be described.
Here, a case will be described in which the memory directions of the bent shapes of the shape memory alloy pipes 54a to 54h are outwardly bent and stored as indicated by arrows in FIG. 8 (A).

First, when the tubular structure 51 of this embodiment is bent in the UP direction in FIG. 5B, for example, the heater 55 provided in the vicinity of the shape memory alloy pipe 54a is heated to store the shape memory. The alloy pipe 54a is heated.
In this case, the shape memory alloy pipe 54a remembers the bent shape, and therefore bends in the UP direction. Further, in order to bend the tubular structure 51 in the UP-RIGHT direction, similarly, if the pipe of the shape memory alloy pipe 54b is heated, it can be bent in that direction.

Furthermore, when both the shape memory alloy pipe 54a and the shape memory alloy pipe 54b are heated, the shape memory alloy pipe is bent by bending in the middle direction to change the heating amount ratio. The direction can be freely changed within the range between 54a and the shape memory alloy pipe 54b. Note that FIG. 9 shows a curved state of the tubular structure 51.

When the tubular structure 51 is returned from the bent shape to the straight shape, the shape memory alloy pipes 54a to 54a are used.
When 4h is a one-way shape memory, the tubular structure 51 is linearized by heating, for example, the shape memory alloy pipe 54e arranged on the opposite side of the shape memory alloy pipe 54a heated at the time of bending. Heat until returned. When the shape memory alloy pipes 54a to 54h are two-way shape memory, the shape memory alloy pipes 54a heated at the time of bending can be recovered by cooling the shape memory alloy pipes 54a.

As described above, the tubular structure 51 of the present embodiment.
Can be bent in all directions by heating the shape memory alloy pipes 54a to 54h. The tubular structure 5 is controlled by controlling the heating of the pipes 54a to 54h.
The tip portion of 1 can be accurately directed to the observation site, and the shape memory alloy pipes 54b, 54d, 54f, 5
By inserting forceps or the like that grips the object from 4h, the treatment can be performed at the distal end of the tubular structure 51.

Therefore, in the above-mentioned structure, since the shape memory alloy pipes 54a to 54h have a space, the internal space of each of the shape memory alloy pipes 54a to 54h is used to store an internal component or the like. The internal space of the tubular structure 51 can be effectively utilized.

10A and 10B show the fourth embodiment of the present invention. This is a modification of the memory shape of the shape memory alloy pipes 54a to 54h in the third embodiment. That is, in this embodiment, the shape memory alloy pipes 54a to 54h are provided with a plurality of joint portions 61a to 61f along the axial direction as shown in FIG. 10A, and the joint portions 61a to 61f are provided with the joint portions shown in FIG. The bending shape shown in () is stored in advance. In addition, each joint 61
a to 61f are the first bending tube 52 and the second bending tube 53.
Is arranged at a position corresponding to the thin portion 16 of the.

Furthermore, each shape memory alloy pipe 54a-5
On the outer peripheral surface of 4h, heaters 62 are independently mounted at positions corresponding to the joints 61a to 61f. Here, the heaters 62 of the joints 61a to 61f can be independently heated and controlled by a controller on the near side (not shown), and the joints 61a to 61f at arbitrary positions can be controlled.
Can be selectively heated.

During operation of this embodiment, a plurality of shape memory alloy pipes 54 are controlled by a controller on the near side not shown.
By determining which pipe is selected from a to 54h, and further determining which joint of the plurality of joints 61a to 61f of the pipe is to be energized and heated by the heater 62 of each joint 61a to 61f. Each of 61f can be bent in any direction. Thereby, the tubular structure 5
This tubular structure 51 is formed by selectively bending the thin wall portions 16 of the first bending tube 52 and the second bending tube 53 in FIG.
Can be bent in the desired direction.

Therefore, in the above structure, the bending operation of the tubular structure 51 can be controlled in multiple degrees of freedom, and the bending operation of the tubular structure 51 can be accurately controlled. Furthermore, since each shape memory alloy pipe 54a to 54h has a space inside, each shape memory alloy pipe 54
The internal space of a to 54h can be used for housing a built-in object, etc., and the internal space of the tubular structure 51 can be effectively used.

The present invention is not limited to the above embodiments, and it goes without saying that various modifications can be made without departing from the gist of the present invention. Next, other characteristic technical matters of the present application will be additionally described as follows.

(Additional Item 1) A curved flexible tube, which is made of a metal material that causes a thermoelastic martensitic transformation in a cylindrical shape, and is partially thin.

(Additional Item 2) The curved flexible tube according to Additional Item 1, wherein a conductive material is formed on the surface of the metal material other than the thin portion. (Additional Item 3) The curved flexible tube according to Additional Items 1 and 2, wherein the metal material is a NiTi-based alloy.

(Additional Item 4) The cylindrical metallic material forms a thin portion along the circumference, and the plurality of thin portions are provided at regular intervals in the axial direction. Flexible tube. (Additional Item 5) The curved flexible tube according to Additional Items 1 and 2, wherein heating means is provided for the cylindrical metal material.

(Additional Item 6) The curved flexible tube according to Additional Item 5, wherein the heating means is an electric heating to the metal material. (Additional Item 7) The curved flexible tube according to Additional Item 5, wherein the heating means is a heater provided along the metal material.

(Additional Item 8) The curved flexible tube according to Additional Item 3, wherein the NiTi alloy causes stress-induced martensitic transformation. (Additional Item 9) A step of applying an etching resistant coating to the surface of a metal material that causes a cylindrical thermoelastic martensitic transformation, and then selectively exposing the metal surface, and a step of thinning the exposed portion by etching A method for manufacturing a curved flexible tube.

(Additional Item 10) The bending tube according to Additional Item 2, wherein the conductive material is platinum. (Additional Item 11) An endoscope comprising the bending flexible tube according to Additional Item 1 in a part of an insertion portion, and comprising an observing unit and an illuminating unit.

(Additional Item 12) A plurality of NiTi-based alloy cylindrical members that undergo a memory treatment of a curved shape and undergo thermoelastic martensitic transformation are arranged in a tubular structural member, and the stored curved shapes are in different directions. The endoscope is characterized in that the light guide means, the image transmission means, and the heating means are incorporated inside the cylindrical member.

(Additional Item 13) The endoscope according to Additional Item 12, wherein the cylindrical members are arranged side by side in an annular shape inside the tubular structure. (Additional Item 14) The endoscope according to Additional Item 12, wherein the tubular structure is an elastic tube. (Additional Item 15) The additional item 1 wherein the heating means is a heater.
The endoscope according to 2.

[0074]

According to the present invention, since the tubular body made of the metal material which causes the thermoelastic martensitic transformation is provided and the thin wall portion is provided in a part of the tubular body to facilitate the deformation, It can be easily formed without the need for assembly, and
The strength of the entire curved tube can be sufficiently ensured.

[Brief description of drawings]

FIG. 1 shows a first embodiment of the present invention (A)
Is a front view showing an arrangement state of an operation wire fixed to the inner surface of the bending tube, and (B) is a side view showing an upper half of the bending tube in section.

FIG. 2 is a perspective view showing a schematic configuration of the entire medical endoscope.

FIG. 3 is an explanatory view illustrating a procedure for manufacturing a bending tube.

FIG. 4 is an explanatory view illustrating a procedure for manufacturing the bending tube according to the second embodiment of the present invention.

FIG. 5 shows a third embodiment of the present invention (A)
Is a sectional perspective view showing a curved portion of the endoscope, and (B) is a sectional view taken along line L ₁ -L ₁ of (A).

FIG. 6 is a side view showing an arrangement state of thin-walled portions of two curved tubes.

7A is a perspective view showing a mounted state of a heater mounted on a shape memory alloy pipe, FIG. 7B is a perspective view showing a modified example of a mounted state of the heater, and FIG. 7C is a mounted state of the heater. The perspective view which shows another modification.

FIG. 8A is a cross-sectional view showing an example of a bending shape memory direction of a shape memory alloy pipe, and FIG. 8B is a cross-sectional view showing another example of a bending shape memory direction of a shape memory alloy pipe.

FIG. 9 is a side view showing a curved state of the bending tube.

FIG. 10 shows a fourth embodiment of the present invention,
(A) is a side view showing a state before bending, and (B) is a side view showing a bending state of a bending tube.

[Explanation of symbols]

 14, 32 ... Tube body, 16, 35 ... Thin portion.

Front Page Continuation (72) Inventor Shinji Kaneko 2-43-2 Hatagaya, Shibuya-ku, Tokyo Inside Olympus Optical Co., Ltd.

Claims (1)

[Claims] 1. A bendable structure characterized in that a tubular body made of a metal material that undergoes thermoelastic martensitic transformation is provided, and a thin wall portion is provided in a part of the tubular body to facilitate deformation. Flexible tube.