JPH08110480A - Flexible tube - Google Patents

Abstract

PURPOSE: To obtain a flexible tube which can be bent with small power. CONSTITUTION: This tube consists of a shape memory alloy coil 14 comprising a shape memory alloy which can stretch or contract in the axial direction according to the temp. change, and a rodlike bending member 13 comprising a shape memory alloy which partly inhibits stretching and contraction of the shape memory alloy coil 14 and bends according to the temp. change. The shape memory alloy coil 14 and the bending member 13 are connected through wires 15 to a controlling means which controls heating.

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 bending an insertion portion inserted into a duct such as a living body cavity.

[0002]

2. Description of the Related Art In recent years, by inserting an elongated insertion portion into a body cavity, the inside of the body cavity is observed and, if necessary, a treatment is performed by using a treatment tool, or the insertion portion is inserted into a tube. An endoscope apparatus that can be inserted into a hole to observe the inside of the tube hole is widely used.

[0003] These observed parts in the body cavity and the lumen are rarely present in the insertion direction of the insertion part. Therefore, when observing or the like, the curvature provided on the distal end side of the insertion part. By bending the portion, the tip portion is directed to the observed region.

As a means for bending the bending portion, an operating wire is inserted through the insertion portion, one end of the operating wire is fixed to the distal end side of the bending portion, and a base end is provided on the operating portion. The technology connected to the operation knob is generally used. Then, the bending operation knob is operated to pull or loosen the operation wire to bend the bending portion, and the distal end portion is directed to the observed region.

However, such a structure inevitably complicates the structure, and it is difficult to reduce the cost.

Therefore, for example, in Japanese Patent Laid-Open No. 59-97115, one side of a pair of opposed flanges is connected by an elastic body, and a heat-sensitive deformable member such as a shape memory alloy is formed in a coil shape between the flanges. A technique is disclosed in which the inserted units are arranged in series in the insertion portion so that the directions of the rotational directions are sequentially different, and the heat-sensitive deformable member can be selectively heated. When the heat-sensitive deformable member is heated by energizing the heat-sensitive deformable member, the portion of the insertion portion where the heat-sensitive deformable member is arranged is bent in a predetermined direction.

[0007]

However, in the conventional bending means, it is necessary to bend the elastic body by the force of the coil-shaped shape memory alloy against the elastic force of the flange-shaped elastic body, and a large amount of force is required. Therefore, if the size of the coil-shaped shape memory alloy is reduced, the force becomes insufficient, and it is difficult to reduce the size.

The present invention has been made in view of the above circumstances, and an object thereof is to provide a flexible tube which can be bent with a small amount of force and which can be miniaturized.

[0009]

Means and Actions for Solving the Problems
In order to achieve the above object, a tubular elastic member made of a shape memory alloy that expands and contracts in the axial direction according to temperature changes, and a shape memory that restricts expansion and contraction of a part of the elastic member and bends according to temperature changes. It is characterized by comprising a bending member made of an alloy, and a control means for heating and controlling the elastic member and the bending member.

When the elastic member and the bending member are heated by the control means, the elastic member tends to contract in the axial direction.
At this time, since the elastic member is constrained by the bending member so as not to expand or contract, the elastic member and the bending member bend. Further, when the elastic member and the bending member are cooled, the elastic member tries to expand in the axial direction, but since the elastic member is constrained by the bending member, the elastic member and the bending member become linear.

[0011]

Embodiments of the present invention will be described below with reference to the drawings.

1 to 6 show a first embodiment, FIG. 1 shows a flexible tube provided in an insertion portion of an endoscope, and FIG. 2 shows an endoscope apparatus. The schematic configuration of the endoscope apparatus will be described with reference to FIG. 2. Reference numeral 1 denotes an endoscope that is inserted into, for example, a blood vessel or the like, and the insertion portion 2 is formed to have an extremely thin diameter of 1 to 2 mm.

A branch portion 3 is provided on the base end side of the insertion portion 2 and is provided with a first cable 3a and a second cable 3b extending from the branch portion 3. First cable 3a
Is releasably connected to the TV camera unit 5 having the TV motor 5a and the light source device 4. Then, the illumination light from the light source device 4 is transmitted to the distal end portion 6 of the insertion portion 2 via a light guide (not shown) arranged in the cable 3a, and is irradiated from the distal end portion 6 to the observed region, The image of the observed region is transmitted to the TV camera unit 5 via an image guide (not shown), processed, and output to the TV monitor 5a. The second cable 3b is detachably connected to a heating control unit 8 having a bending operation unit 7 and an air-cooling cooling device 9.

Further, a bending portion 10 as a flexible tube is provided on the base end side of the tip portion 6, and the bending portion 10 is provided.
By bending, the tip portion 6 can be directed to the target observed region.

The bending portion 10 will be described with reference to FIG. 1. A rod-shaped bending member 13 made of a shape memory alloy that stores a bending shape is fixedly connected between the cylindrical member 11 and the flexible tube 12, and the cylindrical member is further provided. 11 and a shape memory alloy coil 14 as a stretchable member formed in a coil shape having substantially the same diameter as the flexible tube 12 are provided.

At both ends of the shape memory alloy coil 14,
The current-carrying wire 15 is connected to enable current-heating. As shown in FIG. 3, the memorized shape of the bending member 13 is curved as shown by a chain double-dashed line when heated, and when cooled, shows a linear shape as shown by a solid line or a shape bent in the opposite direction. It is a directional shape memory alloy, and the shape memory alloy coil 14 exhibits bidirectionality that contracts in the axial direction when heated and expands when cooled. Further, as for the positional relationship between the bending member 13 and the shape memory alloy coil 14, as shown in FIG. 4 (a), the bending direction of the bending member 13 is an arrow in a substantially central direction of the shape memory alloy coil 14. Is suitable for.

There are other methods of combining the bending member 13 and the shape memory alloy coil 14, for example, assuming that the shape memory alloy coil 14 expands when heated and contracts when cooled, the two arrangement positions are shown in FIG. As shown in (b), the bending direction of the bending member 13 may be the circumferential direction as indicated by the arrow. Further, the transformation temperature of the bending member 13 is lower than that of the shape memory alloy coil 14. Alternatively, the shape memory alloy coil 14 and the bending member 13 may have substantially the same transformation temperature, and heating control means may be provided for each.

Further, as shown in FIG. 5, the outer peripheral portion of the shape memory alloy coil 14 is covered with a thin outer skin tube 16, for example, a tube of silicon, Teflon, urethane or the like, and the inside is for observation. The image guide 17, the light guide 18 for illumination, the conducting wire 15, the bending member 13, and a channel 19 for inserting a treatment tool such as biopsy forceps to perform treatment are internally provided.

Next, the bending portion 10 constructed as described above.
The operation of will be described.

When the bending operation section 7 shown in FIG. 2 is operated, the heating control section 8 energizes the shape memory alloy coil 14 and electrically heats the shape memory alloy coil 14, so that it tries to contract in the axial direction. At this time, since the shape memory alloy coil 14 is constrained by the bending member 13 so as not to expand and contract, it bends upward in FIG. Further, heat generated when the bending member 13 heats the shape memory alloy coil 14 by electric conduction is transmitted, and the bending member 13 bends upward in FIG.

Therefore, the bending portion 10 is bent as shown in FIG. When the operation of the bending operation portion 6 is stopped, the cooling device 9 operates to forcibly cool the bending member 13 and the shape memory alloy coil 14, so that the bending shape of the bending portion 10 becomes linear. . In this case, when the shape memory alloy coil 14 contracts, the bending portion 10
The bending direction of the bending member 13 coincides with the bending direction of the bending member 13.

According to the first embodiment, as the structure for bending using the shape memory alloy coil 14, it is necessary to restrain the coil side surface by the bending member 13 so as not to expand or contract. Since 13 is an elastic body and does not resist bending, the bending angle can be increased and
The shape memory alloy coil 14 can be downsized. Also,
The inside is a space, which is effective for containing many internal components.

FIG. 7 shows a second embodiment. As a configuration of the bending portion 10, a part of the peripheral wall of the shape memory alloy pipe 20 is cut out as shown in FIG.
4 is fixed. Then, the notched portion of the shape memory alloy pipe 20 shows a bent shape during heating as in the first embodiment, and becomes a straight shape when cooled. Further, the shape memory alloy coil 14 and the cutout portion of the shape memory alloy pipe 20 are electrically insulated. For example, the shape memory alloy coil 14 may be coated with a thin tube on the outside thereof, and an insulating coating may be applied, or the inside of the notch of the shape memory alloy pipe 20 may be insulated coated. The insulating coating includes fluororesin, Teflon, ceramics and the like.
Others are the same as those in the first embodiment.

According to the second embodiment, in addition to the effect of the first embodiment, the number of parts constituting the bending portion 10 is small, the structure is simple, and the assembling property is good.

FIG. 8 shows a third embodiment. A plurality of bending portions 10 of the first embodiment are provided in the axial direction as shown in FIG.
These are connected. A plurality of shape memory alloy coils 14 are connected via a connecting member 21 and the bending member 13 is fixed to each portion as in the first embodiment.

The bending direction of the bending member 13 is 9
Different connections are made every 0 ° or every 180 °. Alternatively, a plurality of units connected in the same direction may be regarded as one unit, and some units may be connected in different directions. Each shape memory alloy coil 14 is provided with a current-carrying wire 15 so that heating can be controlled independently. The other structure is the same as that of the first embodiment.

The operation of the third embodiment is basically the same as that of the first embodiment, and the portion to be curved is selectively heated. By selecting this heating portion, the bending portion 10 is freely bent. Therefore, the bending portion 10 can be bent in multiple degrees of freedom, and the observation performance is improved.

9 and 10 show a fourth embodiment.
As shown in FIG. 9, a single shape memory alloy coil 22 that contracts when heated and expands when cooled is provided with a plurality of bending members 23 made of a shape memory alloy that stores a bending shape in the longitudinal direction. The memory alloy coil 22 and the bending member 23 have their contact portions fixed by welding, bonding, or mechanical connection as shown in FIG. At this time, the bending member 23
Are provided in different directions every 90 ° or 180 ° or in the same direction. And the shape memory alloy coil 22
The conducting wire 23a is connected at the position shown in the drawing
Each part can be independently energized and heated. Others are the same as those of the third embodiment, but in addition to the effects of the third embodiment, the configuration is simple and the assemblability is good.

11 and 12 show a fifth embodiment. As shown in FIG. 11, a curved member 25 made of a plate-shaped shape memory alloy in which bending is memorized by heating is fixed between two cylindrical members 24, contracted by heating between the cylindrical members 24, and expanded by cooling. A plurality of shape memory alloy wires 26 are provided by being bent back, and an energizing wire 27 is connected to the end portion. A heater 28 is attached to the bending member 25 as shown in FIG. An elongated tube 29 is connected to the rear of the curved portion 10. In this case, the transformation temperatures of the bending member 25 and the shape memory alloy wire 26 are substantially the same. The other structure is basically the same as that of the first embodiment.

Next, the operation of the fifth embodiment will be described. First, when the shape-memory alloy wire 26 is electrically heated, the shape-memory alloy wire 26 contracts, but part of the shape-memory alloy wire 26 is constrained by the bending member 25, so that the shape-memory alloy wire 26 tries to bend upward in the drawing. At this time, the bending member 25 is also heated by the heater substantially at the same time, so that the bending member 25 is bent in addition to the shape memory alloy wire 26. Then, while heating to both shape memory alloys is stopped, both shape memory alloys return to their original shapes and the curved portion 10 becomes linear.

According to this embodiment, the shape memory alloy wire 26 is generally capable of exerting a large force, can increase the amount of force when being bent, and the bending portion 10 has a certain degree of flexibility. Therefore, the insertability can be improved. Further, the curved portion 10 can be durable.

FIG. 13 shows a sixth embodiment, which has a structure in which a plurality of shape memory alloy coils 30 formed in a coil shape are folded back in place of the shape memory alloy wire 26 of the fifth embodiment. is there. Others are the same as those in the fifth embodiment.

According to this embodiment, since the shape memory alloy coil 30 can obtain a large stroke, a large bending angle can be obtained.

In the fifth and sixth embodiments, one of the shape memory alloy wire 26 and the shape memory alloy coil 30 is provided by being folded back a plurality of times. May be electrically connected in series or mechanically in parallel, or may be electrically connected in parallel.

FIG. 14 shows the first disclosed example, and as a means for heating the bending member 13 in the bending portion 10 formed of the bending member 13 made of a shape memory alloy and the shape memory alloy coil 14 formed in a coil shape. Laser light guide fiber 31
Is the case of using. The laser light guide fiber 31 is housed in the flexible tube 12, and the distal end portion 31 a has a curved portion 1.
The base end portion 31 b faces the emitting portion of the semiconductor laser 33 via the half mirror 32. A reflection light detector 34 is provided on the reflection light path of the reflection surface of the half mirror 32, and a detection signal of the reflection light detector 34 controls a heating control unit 35 for controlling the semiconductor laser 33.
Is input to

Therefore, the laser light emitted from the semiconductor laser 33 passes through the half mirror 32 and enters the base end portion 31b of the laser light guide fiber 31, and the tip end portion 31 thereof.
The light is emitted from a toward the bending member 13. Bending member 13
When heated by the laser light, the light is bent and the reflected light from the bending member 13 enters the half mirror 32 through the laser light guide fiber 31. The reflected light is reflected by the half mirror 32 and detected by the reflected light detector 34. At this time, since the distance is different and the intensity of the reflected light is different depending on the bending amount of the bending member 13, the bending amount of the bending portion 10 can be detected by detecting the intensity of the reflected light by the reflected light detector 34.

FIG. 15 shows a second disclosed example, in which the shape memory alloy coil 14 is heated in the bending portion 10 composed of the bending member 13 made of a shape memory alloy and the shape memory alloy coil 14 formed in a coil shape. This is the case where the laser light guide fiber 31 is used as the means. Laser light guide fiber 3
1 is housed in a flexible tube 12 and has a tip portion 31a.
Faces the shape memory alloy coil 14 of the bending portion 10.

Therefore, the deformation of the shape memory alloy coil 14 due to the bending of the bending portion 10, that is, the bending amount of the bending portion 10 can be detected by the laser light guide fiber 31. FIG. 16 shows a third disclosed example. In the bending portion 10 including the bending member 13 made of a shape memory alloy and the shape memory alloy coil 14 formed in a coil shape, the bending member 13 is directly heated by the semiconductor laser 33. The bending portion 10 is configured to bend. That is, the pickup 36, which is a micronized solid-state device, includes the half mirror 32, the semiconductor laser 33, and the reflected light detector 3.
4 and a heating control section 35 are provided, and the pickup 36 is provided in the bending section 10 to directly heat the bending member 13 by the laser light emitted from the semiconductor laser 33, thereby controlling the bending section 10. You can

FIG. 17 shows a fourth disclosed example, in which the temperature of the bending member 13 is detected instead of the reflected light detection of the first disclosed example. That is, the temperature indicating material 37 is attached to the bending member 13, and the color detector 38 is provided on the reflection optical path of the reflection surface of the half mirror 32.

Therefore, the laser light emitted from the semiconductor laser 33 passes through the half mirror 32 and enters the base end portion 31b of the laser light guide fiber 31, and the tip end portion 31 thereof.
It is emitted from a toward the temperature indicating material 37 of the bending member 13. The bending member 13 bends when heated by the laser light, and the temperature indicating material 37 receives the heat of the bending member 13 and changes color. By accurately measuring the color change of the temperature indicating material 37 by the color detector 38 via the laser light guide fiber 31 and the half mirror 32, the bending amount of the bending member 13 can be indirectly detected. In response to the output signal from the container 38, the heating controller 35 causes the semiconductor laser 3
3 can be controlled to control the bending amount of the bending portion 10. In addition,
The temperature indicating material 37 may be attached to the shape memory alloy coil 14 instead of the bending member 13.

FIG. 18 shows the fifth disclosed example, and the radiation temperature of the bending member 13 is detected instead of the reflected light detection of the third disclosed example. That is, the pickup 36, which is a micronized solid-state device, is provided with the half mirror 32, the semiconductor laser 33, the radiation temperature detector 39, and the heating controller 35. The bending member 13 can be bent by directly heating the bending member 13 with the laser light emitted from 33.

The radiation temperature of the bending member 13 is determined by the half mirror 3.
The amount of bending of the bending member 13 can be indirectly detected by reflecting radiation 2 and being detected by the radiation temperature detector 39 and measuring the radiation temperature precisely. The output signal from this radiation temperature detector 39 Thus, the heating control unit 35 can control the semiconductor laser 33 to control the bending amount of the bending unit 10. The shape memory alloy coil 1 is used instead of the bending member 13.
4 may be directly heated by the laser light emitted from the semiconductor laser 33.

FIG. 19 shows a sixth disclosed example and shows a multidirectional bending mechanism which is a modification of the second embodiment shown in FIG. A second tube 42 such as a flexible silicon tube is connected to the tip of a first tube 41 such as a Teflon tube, and a shape memory alloy pipe 43 having a notch is connected to the tip of the second tube 42. Has been done. The memory shape of the shape memory alloy pipe 43 at the time of heating is stored so as to bend in the direction of a in the figure, as in the second embodiment. Second tube 42 and shape memory alloy pipe 4
A shape memory alloy coil 44, which contracts when heated and expands when cooled, is provided in the interior of the coil 3.
The other end of the tube 41 is connected to the tip of the shape memory alloy pipe 43. The second tube 42 and the shape memory alloy coil 44 constitute a rotating portion 45 that rotates (twists) around its axis.

The shape memory alloy pipe 43 is provided with a notch 46 in a part of its peripheral wall, and the shape memory alloy coil 44 that contracts in the axial direction during heating and expands during cooling is provided inside. The memory alloy pipe 43 and the shape memory alloy coil 44 form a bending portion 47 that bends toward the notch 46. The shape memory alloy coil 44 is connected to a lead wire 48 for electric heating,
It is connected to a power source (not shown) provided on the near side of the first tube 41.

According to the multi-directional bending mechanism configured as described above, the bending portion 47 is bent in the direction of arrow a by the notch portion 46 by heating the shape memory alloy coil 44 by supplying electricity to the shape memory alloy coil 44. Is a shape memory alloy coil 4
Since 4 contracts while twisting, the second tube 42 also twists in the direction of the arrow b. Therefore, by combining bending and twisting, the tip of the shape memory alloy pipe 43 can be bent in any direction. Therefore, by incorporating an image guide fiber and a light guide fiber (not shown) in the first and second tubes and the shape memory alloy pipes 41 to 43, they can be applied to medical and industrial endoscopes. Instead of the shape memory alloy pipe at the tip, an elastic tube may be made of urethane, Teflon, silicone, or the like.

FIG. 20 shows a seventh example of disclosure and shows another example of the multidirectional bending mechanism. A second tube 52 such as a flexible silicon multi-lumen tube is connected to the tip of a first tube 51 such as a Teflon multi-lumen tube, and a second tube 52 such as a Teflon multi-lumen tube is connected to the tip of the second tube 52. 3 tubes 53 are connected. A shape memory alloy coil 54 that contracts when heated and expands when cooled is fitted around the outer circumference of the second tube 52. One end of the shape memory alloy coil 54 is connected to the first tube 51, and the other end is connected to the end of the third tube 53. Are linked to. And
Rotating part 55 that rotates (twists) about its axis by the second tube 52 and the shape memory alloy coil 54.
Is composed.

A shape memory alloy wire 56, which is curved at the time of heating and extends straight at the time of cooling, is provided in a part of the peripheral wall of the third tube 53 along the axial direction, and by the third tube 53 and the shape memory alloy wire 56. The curved portion 57 is configured. Further, the shape memory alloy coil 54 and the shape memory alloy wire 56 are connected to lead wires (not shown) for electric heating, respectively, and are connected to a power source (not shown) provided on the proximal side of the first tube 51. ing.

According to the multi-directional bending mechanism configured as described above, the shape memory alloy wire 56 is bent when energized and heated, and the bending portion 57 is bent in the direction of arrow a. When the shape memory alloy coil 54 is energized and heated, the shape memory alloy coil 54 contracts while being twisted, so that the second tube 52
Also twists in the direction of arrow b, so that the third tube 53 also rotates in the direction of arrow c around the axis. Therefore, by combining the bending and twisting, the third tube 53
The tip of the can be curved in any direction. Therefore, by incorporating an image guide fiber and a light guide fiber (not shown) in the first to third tubes 51 to 53, they can be applied to medical and industrial endoscopes.

FIG. 21 shows an eighth disclosed example. In place of the shape memory alloy wire 5 in the multidirectional bending mechanism of the seventh disclosed example, a bidirectional shape memory alloy plate 58 as an actuator is attached to the third tube 53. The curved portion 59 is provided by the third tube 53 and the shape memory alloy plate 58. Further, instead of the shape memory alloy plate 58, an angle wire (not shown) for operating the bending portion 59 on the hand operating portion side may be provided as an actuator to bend the bending portion 59.

FIG. 22 is a ninth disclosure example and shows a bending mechanism which is another modification of the second embodiment shown in FIG. In the figure, a notch 61 is formed in the peripheral wall of the shape memory alloy pipe 60 bent downward and memorized, and the curved part 6 is provided.
Make up 2. Inside the shape memory alloy pipe 60 located in the curved portion 62, a first shape memory alloy coil 63 that expands when heated and contracts when cooled is installed, and both ends thereof are fixed to both ends of the curved portion 62. There is. Curved portion 62
A second shape memory alloy coil 64 that contracts when heated and expands when cooled is installed in the rearward shape memory alloy pipe 60, the base end of which is fixed to the shape memory alloy pipe 60, and the tip end of which is the first. The shape memory alloy coil 63 is fixed to the distal end portion of the bending portion 62 via a pulling wire 65 passing through the inside. In addition, the first and second shape memory alloy coils 6
3 and 64 are lead wires for electric heating (not shown)
Is connected to a power source (not shown) provided on the proximal side of the shape memory alloy pipe 60.

Therefore, the first shape memory alloy coil 6
When 3 is energized and heated, the first shape memory alloy coil 6
3 extends, and when the first shape memory alloy coil 63 is heated to the notch 61 of the shape memory alloy pipe 60, heat is transferred and bent, and the bending portion 62 is bent in the arrow a direction by both forces. When the energization of the first shape memory alloy coil 63 is stopped, the first shape memory alloy coil 63 is cooled and contracts to try to bend in the opposite direction, and the notch 61 of the shape memory alloy pipe 60 is cooled. It becomes almost straight. When the second shape memory alloy coil 64 is energized and heated, the second shape memory alloy coil 64 contracts. Therefore, the pulling wire 65 is pulled to pull the tip of the bending portion 62, and the bending portion 62 is Curved in the direction of arrow b. At this time, since the notch 61 of the shape memory alloy pipe 60 is not heated, it does not have a large resistance.

By selectively energizing the first and second shape memory alloy coils 63 and 64 in this manner, the bending portion 6
2 can be curved in the directions of arrow a and arrow b. Although the tip portion is a shape memory alloy pipe in FIG. 22, an elastic tube made of urethane, Teflon, silicon or the like may be used as the third tube instead. The operation in this case will be described.

When the first shape memory alloy coil 63 is energized and heated, the first shape memory alloy coil 63 expands, so that the bending portion 62 bends in the direction of arrow a. When the first shape memory alloy coil 63 is de-energized, it is cooled and the first shape memory alloy coil 63 contracts and tries to bend in the opposite direction, but the notch 61 of the tube body 60 becomes a resistance. It becomes almost straight. When the second shape memory alloy coil 64 is energized and heated, the second shape memory alloy coil 64 contracts. Therefore, the pulling wire 65 is pulled to pull the tip of the bending portion 62, and the bending portion 62 is Curved in the direction of arrow b.

By selectively energizing the first and second shape memory alloy coils 63 and 64 in this manner, the bending portion 6
2 can be curved in the directions of arrow a and arrow b. In addition, the first and second shape memory alloy coils 63, 64
Are arranged separately in the axial direction, thermal interference does not occur, and the first and second shape memory alloy coils 63 and 64 are in a heating state and a cooling state, respectively, during bending, and in that state. Since the combination is such that forces are generated in the same direction, there is an effect that the amount of bending force is increased and a large bending angle can be obtained.

FIG. 23 shows a tenth disclosed example, in which a shape memory alloy wire 66 is provided in place of the second shape memory alloy coil 64 and the pulling wire 65 of the ninth disclosed example, and another example. The part is the same as in the ninth disclosed example.

When the first shape memory alloy coil 63 is energized and heated, the first shape memory alloy coil 63 expands, so that the bending portion 62 bends in the direction of arrow a. At this time,
Part of the shape memory alloy wire 66 contracts due to thermal interference, but since the shape memory alloy wire 66 itself is sufficiently long,
It does not hinder the bending motion. Shape memory alloy wire 6
When 6 is energized and heated, the shape memory alloy wire 66 contracts, and the bending portion 62 bends in the direction of arrow b. At this time,
The first shape memory alloy coil 63 overlapping the shape memory alloy wire 66 is affected by heat, but does not reach the transformation temperature because its heat capacity is sufficiently larger than that of the shape memory alloy wire 66. Therefore, the bending operation is not hindered. Further, there is an effect that the bending direction on the low temperature side of the first shape memory alloy coil 63 is amplified by the shape memory alloy wire 66 and a large bending angle can be realized.

FIG. 24 shows an eleventh disclosed example. Instead of the shape memory alloy wire 66 of the tenth disclosed example, a shape memory alloy coil 67 having an outer diameter smaller than the inner diameter of the first shape memory alloy coil 63 is used. Since the other parts are the same as those of the tenth disclosed example and the operation is the same, the description thereof will be omitted.

25 and 26 show a twelfth disclosed example,
The bending mechanism which is a modification of the 1st Example shown in Drawing 1 is shown. A tip ring 72 is connected to the tip of a tube body 70 such as a Teflon tube via a coil spring 71.
The curved portion 73 is configured. Inside the coil spring 71 located in the bending portion 73, a bending plate 74 is provided.
It is rotatably accommodated along the inner circumference of 1.

The tube main body 70 located rearward of the bending portion 73 accommodates a coil portion 75 made of a shape memory alloy that contracts when heated and expands when cooled. One end of the coil portion 75 has a terminal 76a. Is provided, and a flat U-shaped linear portion 77 is provided at the other end. The other end of the linear portion 77 penetrates the coil portion 75, and a terminal 76b is provided at the end thereof. Furthermore, the straight line portion 77
Is fixed to the surface of the curved plate 74. Terminals 76a and 76b are lead wires 78a,
It is connected to a power source (not shown) provided on the proximal side of the tube body 70 via 78b.

When the coil portion 75 and the straight portion 77 are energized and heated, the coil portion 75 contracts and twists, and the bending plate 74 rotates in the direction of arrow d inside the coil spring 71. Furthermore, when the linear portion 77 contracts,
The bending plate 74 bends, and the bending portion 73 bends. Therefore, the bending direction of the bending portion 73 is controlled by the position of the bending plate 74 accompanying the twisting of the coil portion 75, and bending in all directions is possible.

FIG. 27 shows a thirteenth disclosed example, in which the first diode 79 is provided between both ends of the coil portion 75 of the twelfth disclosed example, and the second diode 80 is provided between both ends of the linear portion 77. The coil portion 75 and the linear portion 77 are independently energized and heated so that the bending operation can be performed.

That is, when it is desired to rotate the bending plate 74 in a desired direction, when a negative voltage is applied between the terminals 76a and 76b, the current flows through the terminal 76a-the coil portion 75-.
The second diode 80 flows in the path of the terminal 76b, and the coil portion 75 is heated and rotates. Next, the curved plate 7
In the case of bending No. 4, when a positive voltage is applied between the terminals 76a and 76b, a current flows in the path of the terminal 76b-the coil section 75-the second diode 80-the terminal 76a, and the straight section 77.
Only the current is electrically heated to bend the bending plate 74. Therefore, the bending plate 74 can be bent, rotated, or selectively operated.

FIG. 28 is a fourteenth disclosed example, which is a modification of the twelfth disclosed example and shows a bending mechanism for performing bending and rotation without using a coil spring. Reference numeral 81 is an outer tube having flexibility, and 82 is an inner tube having flexibility. The inner tube 82 has a large diameter channel 83 and two small diameter through holes 8.
4 is a multi-lumen tube having a through hole 84
A straight portion 85 made of a shape memory alloy is inserted into the inner tube 82, which is folded back at the front end side and fixed at the rear end side.

A coil portion 86 made of a shape memory alloy is provided behind the inner tube 82 and connected to one end portion of the linear portion 85, and the other end portion of the linear portion 85 is a conductive wire passing through the inside of the coil portion 86. 87 is provided. The end of the coil portion 86 and the end of the conductive wire 87 are connected to lead wires 89a and 89b via a ring-shaped terminal block 88.

The inner tube 81 is rotatably inserted into the outer tube 82 together with the coil portion 86 and the terminal block 88, and the rear tube 90 is provided at the rear end of the outer tube 82.
It is connected to the.

When the coil portion 86 and the straight portion 85 made of a shape memory alloy are energized and heated, the coil portion 86 contracts and twists, so that the inner tube 82 connected to the coil portion 86 is inside the outer tube 82. To rotate. further,
Since the straight portion 85 contracts, the inner tube 81 bends,
Bent with the outer tube 82. That is, the inner tube 81 bends while rotating with respect to the outer tube 82.

FIG. 29 shows a bending mechanism in a fifteenth disclosed example. A tip ring 93 is connected to a tip portion of a tube body 91 such as a Teflon tube via a shape memory alloy coil 92 that contracts when heated and extends when cooled. Further, between the tube body 91 and the tip ring 93, there is provided a shape memory alloy plate 94 which is curved upward as shown by a solid line in the drawing during heating and curved downward as shown by a broken line during cooling. The shape memory alloy plate 94 is fixed to the tube main body 91 and the tip ring 93 at the end while being inserted into the shape memory alloy coil 92,
Make up 5.

The curved portion 95 is covered with the thin tube 96. Further, the shape memory alloy coil 92 is connected to the tube body 91 via an electric heating lead wire (not shown).
Is connected to a power source (not shown) provided on the near side.

When the shape memory alloy coil 92 is energized and heated, the shape memory alloy coil 92 contracts and the shape memory alloy plate 84 bends upward, so the bending portion 95 bends upward, and when cooled, the shape memory Alloy coil 92
And the shape memory alloy plate 84 bends downward, the bending portion 95 bends downward. By bending the shape memory alloy plate 84 together with the shape memory alloy coil 92, a large bending angle can be obtained with a small amount of force. Further, an articulated manipulator can be configured by connecting a plurality of the above configurations in the axial direction.

According to the above embodiment, the following structure can be obtained.

(Supplementary Note 1) A tubular elastic member which is made of a shape memory alloy and expands and contracts in the axial direction according to a temperature change, and a shape memory alloy which restricts expansion and contraction of a part of the elastic member and bends according to a temperature change. A flexible tube comprising: a bending member made of a member; and a control means for heating and controlling the elastic member and the bending member.

(Supplementary Note 2) The flexible tube according to Supplementary Note 1, wherein the elastic member has a coil shape.

(Supplementary Note 3) The flexible tube according to Supplementary Note 1, wherein the elastic member is formed by folding back a plurality of shape memory alloy wires.

(Supplementary Note 4) The flexible tube according to Supplementary Note 1, wherein the elastic member is formed by folding back a plurality of coil-shaped shape memory alloy wires.

(Supplementary Note 5) The flexible tube according to Supplementary Note 1, wherein the elastic member and the bending member are fixedly supported by a contact portion.

(Supplementary note 6) The flexible tube according to Supplementary note 1 or 4, wherein the elastic member is provided with shape memory alloy wires in a circumferential shape in parallel in the longitudinal direction.

(Supplementary Note 7) The flexible tube according to Supplementary Note 4 or 6, wherein the shape memory alloy wires are electrically connected in series.

(Supplementary note 8) The flexible tube according to supplementary note 1, wherein a plurality of bending units each of which comprises the elastic member and the bending member are connected in the axial direction.

(Supplementary Note 9) The flexible tube according to Supplementary Note 8, wherein the bending units have different bending directions.

(Supplementary note 10) The flexible tube according to supplementary note 8, wherein the bending units have the same bending direction.

(Supplementary Note 11) The elastic member is one, and a plurality of bending members are axially arranged with respect to the elastic member.
The flexible tube according to appendix 1, further comprising: a control unit that independently heats the expandable member and the bending member in substantially equal lengths.

(Supplementary Note 12) The flexible tube according to Supplementary Note 1, wherein a control means for heating is provided on each of the elastic member and the bending member.

(Supplementary note 13) The flexible tube according to claim 1, wherein the transformation temperature of the elastic member is higher than the transformation temperature of the bending member.

(Supplementary Note 14) From a shape memory alloy which is made of a shape memory alloy and which expands and contracts in the axial direction in response to a temperature change, a shape memory alloy which restricts expansion and contraction of a part of the expansion and contraction member and bends in accordance with a temperature change An endoscope apparatus comprising: a bending portion of an endoscope including a bending member, and a control unit that heats and controls the elastic member and the bending member to bend the bending portion.

[0085]

As described above, according to the present invention, the expansion / contraction member made of a shape memory alloy and expanding / contracting in the axial direction according to the temperature change and the expansion / contraction of a part of the expansion / contraction member are restrained to the temperature change. The flexible tube can be bent with a small amount of force by configuring the flexible tube from the bending member made of a shape memory alloy that bends accordingly, and the control means for heating and controlling the elastic member and the bending member. Moreover, it is structurally simple and can be miniaturized, and the diameter of the insertion portion can be reduced, so that there is an effect that the burden on the patient can be reduced by using the endoscope for medical use.

[Brief description of drawings]

FIG. 1 is a perspective view of a flexible tube showing a first embodiment of the present invention.

FIG. 2 is a configuration diagram of an endoscope apparatus of the same embodiment.

FIG. 3 is an operation explanatory view of the flexible tube of the embodiment.

FIG. 4 is an operation explanatory view of the flexible tube of the same embodiment.

FIG. 5 is a sectional view taken along the line AA of FIG. 1;

FIG. 6 is an operation explanatory view of the flexible tube of the embodiment.

FIG. 7 is a perspective view of a flexible tube showing a second embodiment of the present invention.

FIG. 8 is a perspective view of a flexible tube showing a third embodiment of the present invention.

FIG. 9 is a perspective view of a flexible tube showing a fourth embodiment of the present invention.

FIG. 10 is a side view showing a part of the embodiment.

FIG. 11 is a perspective view of a flexible tube showing a fifth embodiment of the present invention.

FIG. 12 is a partial perspective view of the same embodiment.

FIG. 13 is a perspective view of a flexible tube showing a sixth embodiment of the present invention.

FIG. 14 is a configuration diagram showing a bending mechanism as disclosed example 1;

FIG. 15 is a configuration diagram showing a bending mechanism as a second disclosure example.

FIG. 16 is a configuration diagram showing a bending mechanism as a third disclosure example.

FIG. 17 is a configuration diagram showing a bending mechanism as a fourth disclosure example.

FIG. 18 is a configuration diagram showing a bending mechanism as a fifth disclosure example.

FIG. 19 is a perspective view showing a bending mechanism as disclosed example 6;

FIG. 20 is a perspective view showing a bending mechanism as disclosed example 7;

FIG. 21 is a perspective view showing a bending mechanism as disclosed example 8;

FIG. 22 is a perspective view showing a bending mechanism as disclosed example 9;

FIG. 23 is a perspective view showing a bending mechanism as disclosed example 10;

FIG. 24 is a perspective view showing a bending mechanism as disclosed example 11;

FIG. 25 is a side view and an end view showing a bending mechanism as disclosed example 12;

FIG. 26 is a perspective view showing a part of the bending mechanism of the disclosure example.

FIG. 27 is a circuit diagram of a bending mechanism as disclosed example 13;

FIG. 28 is a perspective view showing a bending mechanism as disclosed example 14;

FIG. 29 is a perspective view showing a bending mechanism and a side view of a shape memory alloy plate as disclosed example 15;

[Explanation of symbols]

8 ... Heating control part, 10 ... Bending part, 13 ... Bending member, 14
... Shape memory alloy coil (elastic member).

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[Procedure amendment]

[Submission date] December 8, 1994

[Procedure Amendment 1]

[Document name to be amended] Statement

[Correction target item name] 0016

[Correction method] Change

[Correction content]

At both ends of the shape memory alloy coil 14,
The current-carrying wire 15 is connected to enable current-heating. As shown in FIG. 3, the memorized shape of the bending member 13 is curved as shown by a chain double-dashed line when heated, and when cooled, shows a linear shape as shown by a solid line or a shape bent in the opposite direction. It is a directional shape memory alloy, and the shape memory alloy coil 14 exhibits bidirectionality that contracts in the axial direction when heated and expands when cooled. Further, the positional relationship between the bending member 13 and the shape memory alloy coil 14, as shown in FIG. 4 (a), addition of the curved member 13
The bending direction when heated is oriented substantially in the center of the shape memory alloy coil 14 as indicated by the arrow.

[Procedure Amendment 2]

[Document name to be amended] Statement

[Correction target item name] 0017

[Correction method] Change

[Correction content]

There are other methods of combining the bending member 13 and the shape memory alloy coil 14, for example, assuming that the shape memory alloy coil 14 expands when heated and contracts when cooled, the two arrangement positions are shown in FIG. As shown in (b), the bending direction of the bending member 13 during heating may be the circumferential direction as indicated by the arrow. Further, the transformation temperature of the bending member 13 is lower than that of the shape memory alloy coil 14. Alternatively, the shape memory alloy coil 14 and the bending member 13 may have substantially the same transformation temperature, and heating control means may be provided for each.

[Procedure 3]

[Document name to be amended] Statement

[Correction target item name] 0065

[Correction method] Change

[Correction content]

The inner tube 82 is rotatably inserted into the outer tube 81 together with the coil portion 86 and the terminal block 88, and the rear tube 90 is provided at the rear end of the outer tube 81.
It is connected to the.

[Procedure amendment 4]

[Document name to be amended] Statement

[Correction target item name] 0066

[Correction method] Change

[Correction content]

When the coil portion 86 and the straight portion 85 made of a shape memory alloy are energized and heated, the coil portion 86 contracts and twists, so that the inner tube 82 connected to the coil portion 86 inside the outer tube 81 . To rotate. further,
Since the straight portion 85 contracts, the inner tube 82 bends,
Bent with the outer tube 81 . In other words, the inner tube
The bending operation is performed while rotating 82 with respect to the outer tube 81 .

[Procedure Amendment 5]

[Document name to be amended] Statement

[Correction target item name] 0069

[Correction method] Change

[Correction content]

When the shape memory alloy coil 92 is energized and heated, the shape memory alloy coil 92 contracts and the shape memory alloy plate 94 bends upward, so that the bending portion 95 bends upward, and when cooled, the shape memory alloy Alloy coil 92
As the shape memory alloy plate 94 bends downward, the bending portion 95 bends downward. By bending the shape memory alloy plate 94 together with the shape memory alloy coil 92, a large bending angle can be obtained with a small amount of force. Further, an articulated manipulator can be configured by connecting a plurality of the above configurations in the axial direction.

[Procedure correction 6]

[Document name to be corrected] Drawing

[Name of item to be corrected] Fig. 17

[Correction method] Change

[Correction content]

FIG. 17

[Procedure Amendment 7]

[Document name to be corrected] Drawing

[Correction target item name] Fig. 25

[Correction method] Change

[Correction content]

FIG. 25

Claims (1)

[Claims] 1. A tubular expansion member that is made of a shape memory alloy and expands and contracts in the axial direction according to temperature changes, and a shape memory alloy that restricts expansion and contraction of part of the expansion and contraction member and bends according to temperature changes. A flexible tube comprising: a bending member; and a control means for heating and controlling the elastic member and the bending member.