JPH08206061A - Curving device - Google Patents

Abstract

PURPOSE: To obtain curving to a large extent and ensure a sufficient curving capacity. CONSTITUTION: This curving device is to curve a flexible joint using SMA wires 10, 11 expanding and contracting according to the change in the temp. and is equipped with rotary shafts 8 to convert the contraction force generated when the wires 10, 11 are heated into a bending and a cylindrical members 7 coupled by these shafts 8. The wires 10, 11 are laid parallel in a position where the wire bending direction is approx. the same and the amount of bending capacity as the output at heating of the wires differs, and they are heat controlled by a controlling means one by one from the wire having a greater capacity first.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a bending device such as an endoscope inserted into a living body cavity, a manipulator inserted into a duct or the like, and more particularly, a bending device capable of bending with a plurality of joints.

[0002]

2. Description of the Related Art There are various structures of bending devices such as medical endoscopes to be inserted into a living body cavity and industrial manipulators to be inserted into a duct or the like. On the street.

(1) A shape memory alloy which expands and contracts due to temperature change is arranged in the longitudinal direction of a structure constituted by connecting a plurality of cylindrical members, and the shape memory alloy is heated to shrink the shape memory alloy. Then, the structure is bent.

It is considered that the bending device, for example, an industrial manipulator is used to insert into a complicated pipe or to perform a complicated work in the pipe. The structure has a plurality of bending portions, and each bending portion has a plurality of bending portions. Also requires a large amount of bending. In order to increase the amount of bending, it has been considered to lengthen the shape memory alloy and to arrange the shape memory alloy at a position closer to the rotation axis to which the tubular member is rotatably connected.

(2) In order to insert into a pipe having a complicated shape or to perform a complicated work in the pipe, the structure is provided with a plurality of bending portions and the bending control of the bending portions is performed. In this case, when each curved part of the manipulator becomes thinner,
It becomes difficult to provide a plurality of shape memory alloys in each bending portion to bend in a plurality of directions, and one bending portion makes bending in one direction, and a plurality of them are connected in the longitudinal direction. It is considered to perform complicated work by changing.

(3) In order to increase the amount of bending force in each bending portion, it is known that a plurality of shape memory alloys of each bending portion are provided in parallel or folded back to increase the amount of bending force.

(4) As a constitution of a medical endoscope to be inserted into an extra-fine blood vessel or the like, the distal end portion of the insertion portion is made of a flexible material in order to bend the distal end portion, and a shape memory alloy is provided in the inside thereof to obtain this shape. It is curved by the power of the memory alloy. At this time, for example, the insertion portion was made of Teflon and the tip portion was made of silicon, and the two were connected. However, as a method, a thin tube is inserted inside as a guide, and an ultrafine tube is fitted from the outside and fixed from both sides. There is a way.

(5) As another example of a medical endoscope to be inserted into an extremely thin blood vessel or the like, a shape in which the distal end portion of the insertion portion is made of a flexible material and expands and contracts due to temperature change in order to bend the distal end portion. A memory alloy is arranged, and the tip portion is curved by the force of this shape memory alloy. Then, a current-carrying wire for energizing the shape memory alloy is connected to the caulking member, and in order to fix the caulking member in the insertion portion, a heat-shrinkable tube is tightened from the outside.

(6) In some cases, a shape memory alloy that expands and contracts due to temperature change is provided in the insertion portion, and the tip end portion is curved by the force of the shape memory alloy when the shape memory alloy is heated. It is considered that this curved endoscope is combined with a duodenoscope and is inserted into Ferta's papilla as a parent-child type endoscope to observe the inside of the pancreatic duct. In this case, it is desirable that the child scope has a small diameter and that the shape memory alloy provided therein does not reach a high temperature when the heat is generated.

Therefore, a certain length from the distal end of the insertion portion (the portion that goes out from the duodenoscope) is a stainless steel angle wire, a shape memory alloy is provided behind it, and the shape memory alloy pulls the angle wire. There are some that are curved. The tip portion is bent in a plurality of directions by providing a plurality of combinations of the angle wire and the shape memory alloy in parallel.

[0011]

However, each of the bending devices constructed as described above has the following problems. That is, in (1), when the shape memory alloy is made long, the bending length becomes long, and the bending state also has a gentle bending radius, which makes it difficult to work in a narrow place. In addition, since a large bending occurs in a short bending length, when a shape memory alloy is arranged in the vicinity of the rotation axis, there arises a problem that the force is lowered.

In (2), when the position where the shape memory alloy is arranged is changed and the bending direction is changed, the position where the shape memory alloy is arranged is different depending on each joint. For example, as shown in FIG. 36, the shape memory alloy is formed. 101a and 101b are arranged above and below the structure 102 with the rotating shaft 103 interposed therebetween.
As for the cross section at this time, as shown in FIGS. 37 (a) and 37 (b), it is necessary to provide many grooves for arranging the shape memory alloys 101a and 101b, and the space of the built-in object becomes narrow. Also,
As shown in FIGS. 38 (a) and 38 (b), the structure 102 has a shape
It is conceivable that the shape memory alloys 101a and 101b may have a groove only in the portion where they are arranged, but in this case, the built-in material is not linear and is bent at a position where the shape changes from FIG. 38 (a) to (b). In other words, the smaller the diameter, the more difficult it is to incorporate the built-in object into the structure 102, and the bending action on the built-in object increases, and the load on the built-in object increases.

In the case of (3), when the shape memory alloys arranged in parallel are energized to perform a bending operation, more than one electric power is required, and the length becomes long even when folded back. The electric power becomes large. Furthermore, since there are a plurality of wires in the longitudinal direction, there is a problem that the power source becomes large.

In (4), the strength of the connecting portion between the tip bending portion and the insertion portion is weak, and there is a problem that the bending portion bends during the bending operation. There is also a problem that it is weak against external force.

In (5), since the heat shrink tube is used when fixing the caulking member, it is necessary to apply heat from the outside. When this heat is applied, the shape memory alloy is deformed and the workability is poor, and it is difficult to fix it accurately.

In the case of (6), if the diameter is small, it is difficult to set the shape memory alloy and the angle wire so as to have slack in advance, and tension may be applied in the initial state. Durability may be deteriorated in a configuration in which tension is applied even when not bending. In addition, in this configuration, when used as a parent-child type endoscope in which a shape memory alloy is provided with a certain distance from the distal end, the shape memory alloy is placed inside the channel of the duodenoscope so as not to contact the living body. Even if it is provided, if the child scope is taken out of the channel too much, the shape memory alloy will come into contact with the living body. (However, if you control the length of the child scope from the beginning and consider the length that goes out of the channel according to the required length, placing a shape memory alloy behind it does not cause a problem.) The present invention has been made in view of the above circumstances, and an object thereof is to provide a bending device that can obtain a large bending amount and a sufficient bending force amount.

[0017]

In order to achieve the above object, the present invention provides a bending apparatus for bending a bendable structure with a shape memory alloy that expands and contracts in the axial direction according to temperature changes. The converting means for converting the contracting force during heating of the alloy into bending and the bending direction of the shape memory alloy are substantially the same, and the shape is located at a position such that the amount of bending force as the output during heating of the shape memory alloy is different. Memory alloys are provided in parallel, and a control means for sequentially controlling heating from the shape memory alloy having a large force is provided.

[0018]

In order to bend the joint body as a structure, when electricity is applied to one of the shape memory alloys arranged in the joint body by the energization control unit, the joint body is moved at a position far from the rotation axis connecting the joint bodies. This is a bending operation due to heat shrinkage of the shape memory alloy. It has a large ability but a small angle.
Further, when the shape memory alloy located closer to the rotation axis is electrically heated and contracted by heat, the force is small but the angle is large.

A large force is required to start the operation from a state where the joint bodies are straight and are not bending, but after that, the bending can be held even if the force is not so large. Therefore, when the bending operation is started, one of the shape memory alloys is heated to perform the bending operation with a large amount of force, and then the other shape memory alloy is heated to perform an operation of obtaining a large bending angle.

[0020]

Embodiments of the present invention will be described below with reference to the drawings. 1 to 9 show a first embodiment, and FIG.
1A is an endoscope as a manipulator, which is shown in FIG.
Is an operation unit. As shown in FIGS. 1A and 1B, the endoscope 1 includes an insertion section 2, an operation section 3, and a control section 4. The insertion portion 2 as a bendable structure is configured by connecting a plurality of bendable joint bodies 5a to 5e in series. The proximal end of the insertion section 2 is the operation section 3
The front end portion is provided with a front end forming section 6 incorporating an observation optical system, an illumination optical system, and the like.

The structure of each of the joint bodies 5a to 5e is shown in FIG. That is, each of the joint bodies 5a to 5e is configured by rotatably connecting a plurality of tubular members 7 with rivets 8. The tubular member 7 has a shape of, for example, 2 on the surface as shown in FIG. Grooves 9 are formed in a concave shape at the places. The groove 9 has a distance S from the axis of rotation of the rivet 8 and is provided at a position smaller than the radius of the tubular member 7. The shape memory alloy wire (hereinafter referred to as SMA wire) 10, which contracts when heated to a position (distance S ′) far from the rotation axis of the groove 9 and the rivet 8 and returns to the original length when cooled (heat radiation) 10, 11 are provided respectively.

The SMA wire 10 and the SMA wire 11 have substantially the same displacement amount and substantially the same transformation point. And
The tubular member 7 in which a plurality of SMA wires 10 and 11 are connected is, as shown in FIG. 4, a tubular member such as a thread-like member as the support member 12 for supporting the SMA wires 10 and 11 on the tubular member 7. It is wound around the outer periphery of the member 7. At this time, the support member 12 is attached to the SMA wires 10 and 11
Is not completely fixed to the tubular member 7, but is slidable. In addition, the SMA wire 1
The control unit 4 (see FIG. 1A) for controlling heating of 0 and 11 is provided, and each SMA wire of the plurality of joint bodies 5a to 5e configured as shown in FIG. It is possible to independently and selectively control heating for 10 and 11.

Further, the bending directions of the respective joint bodies 5a to 5e are alternated, for example, as shown by arrows in FIG. 1 (a). 3 and 4, the joint bodies 5a to 5e are drawn with the SMA wires 10 and 11 exposed. However, as shown in FIG. 1C, the outer side is covered with the protective tube 14. The inside is provided with an image guide cable 15 and a light guide cable 16 that are guided to the observation optical system and the illumination optical system provided in the distal end configuration section 6 and a channel tube 17 for inserting a treatment tool. ing.

On the other hand, as shown in FIGS. 1A and 1B, the operation section 3 is provided with bending operation buttons 18a to 18e for bending the joint bodies 5a to 5e of the insertion section 2. . Further, the control unit 4 is provided with an energization unit 19 and an energization control unit 20. In this configuration, the operation button 18
The energization control unit 20 operates according to the signals a to 18e to issue a command to the energization unit 19 so that the linear heater 13 connected to the energization unit 19 is energized.

Next, the operation will be described. In FIG. 1, in order to bend a desired joint body of the insertion portion 2 of the endoscope 1, for example, the joint body 5a, the bending operation button 18a provided on the operation portion 3 shown in FIG. Press the ON side. An operation signal is sent to the energization control unit 20 while the ON side of the bending operation button 18a is being pressed, and the energization control unit 20
Energizes the SMA wire 10 and the SMA wire 11 arranged on the joint body 5a.

At this time, when only the SMA wire 10 is first energized, the SMA wire 10 is bent at a position far from the rotation axis which is the rivet 8 connecting the tubular members 7 with each other. . It has a large ability but a small angle. When only the SMA wire 11 located closer to the rotation axis of the rivet 8 is electrically heated and contracted by heating, the amount of force is small but the angle is large. This will be described with reference to the drawing. As shown in FIG. 5A, the load W lifted when performing a bending operation when the load W is provided at the tip is W = (S / L) F (F: Competence). From this equation, it can be seen that if S is made smaller, the load that can be lifted becomes smaller, and if S is made smaller than that in FIG. 5A, a large bending angle is obtained even if the wire drawing amount x is made small. Further, as the bending progresses, as shown in FIG. 5B, the length is reduced from L to L ′ due to the bending and becomes smaller, and the amount of force for holding the bending becomes a maximum value as shown in FIG. Decrease. In other words, a large force is required when the tubular members 7 start to move from a state where the tubular members 7 are straight and are not bending, but after that, the bending can be held even if the force is not so large. Therefore, when the bending operation is started, the SMA wire 10 is heated to perform the bending operation with a large amount of force, and then the SMA wire 11 is heated to perform an operation of obtaining a large bending angle. At this time, an example of heating control for the SMA wires 10 and 11 is shown in FIG.
Indicated by

The SMA wire 1 is shown in FIGS. 7 (a) and 7 (c).
The heating state of 0 and 11 is shown. First, the SMA wire 1
After heating at 0 for a certain time (Δt ₁ ), the SMA wire 1 is delayed.
The heating to 1 is started, and after a time of Δt ₂ , the SMA wire 10 is turned off and only the SMA wire 11 is heated to be bent. At this time, FIG. 7 shows the curved state when only one of the SMA wires 10 and 11 is heated.
(B) and (d), the bending amount increases with heating, and the bending amount decreases when heating is stopped. And SM
The bending amount when one of the SMA wire 10 and the SMA wire 11 is independently heated at the time (Δt ₁ + Δt ₂ ) at which the heating of the A wire 10 is stopped is set to be approximately Δθ and the same. As a result, the curved state becomes as shown in FIG.

In this way, the bending control of the joint bodies 5a to 5e of the endoscope 1 shown in FIG. 1A is performed, and the bending operation of the selected joint body is performed. An example of the bending operation state is shown in FIG. To bend the tip of the insertion section 2 slightly,
The respective SMA wires 10 and 11 arranged on the joint body 5a or the joint body 5b may be heated, whereby the distal end portion of the insertion portion 2 is (a) or (b) in the figure.
Curve like.

When the respective SMA wires 10 and 11 arranged on the joint bodies 5a, 5c and 5e are heated at the same time, the SMA wires arranged on the joint bodies 5b and 5d as shown in FIG. When the wires 10 and 11 are heated at the same time, the wires 10 and 11 bend as shown in FIG. further,
When the bending of the joint bodies 5a to 5e can be selected according to the use situation, and for example, when the insertion portion 2 is inserted into the curved conduit P as shown in FIG. 9 to observe and treat the site 22 At the same time, the SMA wires 10 and 11 arranged on the joint bodies 5a and 5d can be heated at the same time to bend the insertion portion 2 as shown in the figure.

Therefore, according to the first embodiment,
Two Ss provided at different positions inside the joint bodies 5a to 5e
By selectively heating the MA wires 10 and 11, a large amount of bending force can be obtained, and the bending angle can be increased even when the distal end portion of the insertion portion 2 has a load.

In the multi-joint manipulator having a plurality of joint bodies, when two SMA wires 10 and 11 are arranged in close proximity to each other, one SMA wire 1
When 0 is energized (ON), energization to the other SMA wire 11 is OFF, and when SMA wire 11 is energized (ON), SMA wire 10 is OFF and in parallel SMA wire 10 placed,
The energization may be controlled so that one of the SMA wires 10 or 11 is heated so that both of them are not heated.

When one of the SMA wires 10 is electrically heated as described above, the SMA wires 11 provided close to each other are heated.
When heat is transferred to the SMA wire 11 and the SMA wire 11 is electrically heated, S
The heat is transferred to the MA wire 10 and both may not be heated at the same time. In addition, the heating method for the SMA wires 10 and 11 involves switching between ON and OFF with a certain frequency. If this interval is not long, the SMA wires 10 and 11 will not be cooled and the amount of heat required for transformation will be reduced. It can be kept low.

Furthermore, the SM shown in FIGS. 3 and 4 is used.
Without turning back the A wires 10 and 11 at the tip,
Two SMA wires 10 and 11 are arranged in parallel to form SMA wires 10a, 10b and SMA wire 11 respectively.
a and 11b. Then, the SMA wires 10a and 11
On the other hand, when one SMA wire 10a is energized, the other SMA wire 10b may not be energized by energization control with waveforms opposite to each other. Alternatively, the SMA wires 10a and 10b may not be energized at the same time by shifting the ON state of the pulse waveform. This also applies to the SMA wires 11a and 11b.

In the case of multiple joints, the SMA at each joint
Wires 10a, 10b and SMA wires 11a, 11
By shifting the time with respect to b, there is an advantage that the energization ON state can be reduced as much as possible and the entire energization amount can be reduced.

FIG. 10 shows a second embodiment. In the first embodiment, the bending direction is one joint with one swing, but this is also a double swing, and as shown in the figure, four points on the surface are concavely grooved around the rivet 8 which is the rotation axis. The SMA wires 10 and 11 are formed symmetrically to form 9 and shrink when heated and cool (radiate) to return to the original length. With such a configuration, both the SMA wires 10 and 11 to be heated can be swung by selecting the SMA wires 10 and 11 on the upper side and the lower side in the figure, and the degree of freedom can be increased and a complicated operation can be performed.

11 and 12 show a third embodiment.
Reference numeral 23 shown in FIG. 11 is a multi-lumen tube replacing the joint body of the first embodiment, which is made of a polymer material such as silicon, urethane, Teflon, polypropylene, etc., and has a plurality of holes 23a in the axial direction. It is provided.
Inside the hole 23a, SMA wires 24 and 25 that expand and contract due to temperature change are arranged at the tip of the multi-lumen tube 23, and behind the SMA wires 24 and 25 are lead wires 27a via caulking members 26a and 26b. , 27b.

The small-diameter endoscope 31 having a curved portion formed by the multi-lumen tube 23 constructed as described above is constructed as shown in FIG. 11, and is inserted into a blood vessel or the like. The portion 32 is formed to have a small outer diameter of 1 to 2 mm.

A branch portion 33 is provided on the base end side of the insertion portion 32, and the first cable 3 extended from the branch portion 33.
3a and the 2nd cable 33b are provided. The first cable 33a is detachably connected to the TV camera unit 35 having the TV monitor 35a and the light source device 34. Then, the illumination light from the light source device 34 is transmitted to the distal end forming portion 36 of the insertion portion 32 via a light guide (not shown) arranged in the cable 33a, and is irradiated to the observed region from the distal end forming portion 36. On the other hand, the image of the observed region is displayed on the TV via an image guide (not shown).
The data is transmitted to the camera unit 35, processed, and output to the TV monitor 35a.

On the other hand, the second cable 33b is detachably connected to a heating control section 38 having a bending operation section 37 and an air-cooling cooling device 39, and the second cable 33b is connected via a branch section 33. It is connected to the lead wires 27a and 27b provided inside the insertion portion 32.

Further, a bending portion 40 as a flexible tube is provided on the base end side of the tip forming portion 36, and by bending the bending portion 40, the tip forming portion 36 to be observed. It can be directed to the part.

Next, the operation will be described. When the bending operation section 37 shown in FIG. 11 is operated, the heating control section 38 electrically heats the SMA wires 24 and 25. However, when the bending amount is small, the bending operation is performed by heating only the SMA wire 24, and the bending operation is performed. When the amount increases to a certain degree, the first
The control is performed by switching between the SMA wire 24 and the SMA wire 25 in the same manner as in the above embodiment. Then, when the operation of the bending operation portion 37 is stopped and returned to its original state, the cooling device 39 operates to forcibly cool the SMA wires 24 and 25, so that the SMA wires 24 and 25 extend to the original length, The curved portion 40 has a linear shape.

Therefore, it is possible to construct the endoscope 31 having a small diameter and a large bending amount, which is more effective especially when the distal end forming portion 36 is loaded, and the bending operation can be performed even if there is some load. It will be possible.

13 to 17 show a fourth embodiment. In the first and second embodiments, the configuration in which the force amount and the bending amount are increased is shown, and in the third example, the bending amount is increased by the small diameter. As in the first embodiment, a plurality of joint bodies are provided to reduce the diameter.

As shown in FIG. 13, the rotating shafts 41a of a plurality of rotatably connected tubular members 41 are vertically displaced from the center O, and the SMA expands and contracts substantially at the center due to temperature change.
A wire 42 is arranged. The SMA wire 4 is aligned with the position of the rotary shaft 41a connecting the tubular members 41 to each other.
2 is fixed to the tubular member 41 via fixing members 43a to 43c.

FIG. 16 is a perspective view showing a state in which a plurality of tubular members 41 are connected, and this tubular member 41 is, for example, MIM.
(Metal Injection Molding:
Metal powder injection molding). The surface of the tubular member 41 is coated with an insulating material 44 such as ceramic, fluororesin, Teflon, polyimide, and parisene, and the fixing members 43a and 43b are bonded to the tubular member 41 through the insulating material 44. It is fixed. The fixing members 43a and 43b and the SMA wire 42 are mechanically crimped so as not to slide. It should be noted that the shape of the tubular member 41 is such that the connecting portions on both sides are closer to one side (upper side in the figure) than the center as shown in FIG.
As shown in FIG. 15B, the centers are vertically displaced from each other, and the connecting portion of the connected tubular member 41 has a position where both ends of the SMA wire 42 are located as shown in FIGS. 15A and 15B. However, the rotation shaft 41 between the tubular members 41 is almost the same.
a is vertically displaced as shown in FIGS. 15 (a) and 15 (b).
Further, the lead wire 45 for energization is fixed to the fixing members 43a and 43b.
Are joined by soldering or the like. The SMA wire 42 thus formed is also provided at a position on the opposite side which cannot be seen in FIG. The other structure is the same as that of the first embodiment.

Next, the operation will be described. In FIG. 13, when current is applied between the fixing member 43a and the fixing member 43b, the SMA wire 42 in that portion contracts, so that FIG.
As shown in (a), when the first joint body 46a is curved and current is applied between the fixing member 43b and the fixing member 43c, the SMA wire 42 in that portion contracts and the second joint body 46b.
Bends. Also, the first and second joint bodies 46a, 4
In order to bend 6b simultaneously, electricity is applied between the fixing member 43a and the fixing member 43c. Thus, a plurality of joint bodies 46
A, 46b ... Can be selectively curved. The above bending operation is almost the same as that of the first embodiment.

As shown in FIGS. 15 (a) and 15 (b), SMA
Since the positions where the wires 42 are arranged are the same, the assemblability is good. In addition, the cross-sectional shape is almost the same in every part, the built-in object can be arranged straight, and no unreasonable force is applied to the built-in object. Moreover, the work of inserting the built-in object is easy.

18 and 19 show a fifth embodiment. In place of the tubular member of the fourth embodiment, this embodiment has the configuration shown in FIG.
As shown in FIG. 8, the slit 47a is provided in the pipe-shaped superelastic alloy pipe 47,
The shape is such that a part of 7 is left. Then, the SMA wire 42 is arranged in the central portion outside the superelastic alloy pipe 47. The tip end side portion of the super elastic pipe 47 is shown in FIG.
As shown in FIG. 19A, a part of the upper side of the drawing is left and a plurality of slits 47a are provided. At the next position, as shown in FIG. 19B, a part of the lower side of the drawing is left and a plurality of slits 47a are left. The slits 47a are provided, and then the slits 47a are provided alternately as shown in FIG. 19 (a), which is functionally the same as that of the fourth embodiment. The SMA wire 42 is joined to the superelastic alloy pipe 47 via fixing portions 43a and 43b. The other structure is the same as that of the fourth embodiment.

Next, the operation will be described. Similarly to the fourth embodiment, when the SMA wire 42 between the fixing member 43a and the fixing member 43b is energized, the SMA wire 42 at that portion contracts and bends the slit 47a portion of the superelastic alloy pipe 47. Therefore, it bends in the direction of the arrow in FIG. When the heating of the SMA wire 42 is stopped, the SMA wire 42 returns to its original length and becomes linear due to the elasticity of the superelastic alloy pipe 47. Therefore, since the structure of the joint body is simplified and the joint body itself is not assembled, it is suitable for downsizing.

FIGS. 20 and 21 show a sixth embodiment. Instead of the tubular member of the fourth embodiment, a plurality of pipe members 48 are arranged in the longitudinal direction as shown in FIG. A space 48 a is provided between the pipes 48, and a superelastic alloy rod 49 is fixed to these pipe members 48. At this time, when the pipe member 48 is a nonmetal such as ceramic, Teflon, or polypropylene, bonding is used, and when the pipe member 48 is made of metal such as stainless steel, aluminum alloy, or copper alloy, it is fixed by welding or bonding. The fixed positions are arranged alternately in the upper and lower sides as shown in FIG. 20, and the plurality of joint bodies are configured by alternating the positions as shown in FIGS. 21 (a) and 21 (b). The SMA wire 42 is arranged on the joint body configured as described above, as in the fifth embodiment. The other structure is the same as that of the fifth embodiment. According to the present embodiment, as compared with the fifth embodiment, the number of assembling is increased, but the portion using the superelastic alloy is a simple bar material, and as a result, there is an advantage that the cost is reduced.

FIG. 22 shows a seventh embodiment. Instead of the tubular member of the fourth embodiment, as shown in FIG. 22, four small holes 50a and 50b are formed in the axial direction of a plurality of pipe members 50 made of, for example, a ceramic material. A pipe-shaped space member 51 made of a ceramic material is disposed between the holes 50 of the pipe member 50.
The wire member 52 is inserted into and connected to the holes a, 50b and the space member 51. And the space member 5
A joint body 0 has two holes 50a provided on the upper side of the pipe member 50 and two holes 50b provided on the lower side thereof. The other structure is the same as that of the fourth embodiment.

Next, the operation will be described. When the SMA wire 42 is heated and shrunk, the portion where the space member 51 exists is substantially the center of rotation so that the pipe members 50 rotate and the joint body bends in the direction of the arrow in FIG. When the heating of the SMA wire 42 is stopped, the SMA wire 42 returns to its original length, and is further linearized by the built-in image guide fiber and light guide fiber.

As described above, since most of the parts constituting the joint body are pipe-shaped members and can be easily processed, the material may be a general material, and the structure is simplified, so that it is special. It is not necessary to adopt an assembling method, and cost can be reduced.

FIG. 23 shows an eighth embodiment. This embodiment shows a modification of the third embodiment, in which the multi-lumen tube 23 is divided into a bending portion 53 and an insertion portion 54, and the connecting portions 55 lead wires 27a and 27b and SMA wires 24 and 2.
5 is connected. At this time, in order to prevent the connection portion 55 from being easily broken, the hard ring 56 made of an extremely thin SUS ring is fitted. Here, the bending portion 53
Is formed of a PU-multilumen tube and has an insertion part 5
4 is formed of FEP-multilumen tube. The outer peripheral surface of the channel 57 is formed by an ultrathin FEP tube 58.

With this structure, even if the connecting portion 55 is bent at a large bending angle, the connecting portion 55 can be prevented from being damaged and a smooth curved shape can be obtained. Also, FIG.
Then, the hard ring 56 to the multi-lumen tube 23
It was fitted on the outside of the channel, but as shown in FIG.
A hard ring 56 may be provided on the outer peripheral surface of the outer periphery of the ultra thin FEP tube 58.

25 to 30 show a ninth embodiment. 6
Reference numeral 0 denotes a catheter, which has an insertion portion 61 and a bending portion 62.
And a tip rigid portion 63. The catheter 60 is provided with an angle wire 64 made of, for example, a stainless wire and an SMA wire 65 connected to the rear of the tip hard part 63, the curved part 62 and the insertion part 61 to a certain length.

The catheter 60, as shown in FIG.
For example, a tube made of Teflon with a large diameter hole 6 in the center.
6 and is constituted by a multi-lumen tube 68 having a plurality of small diameter holes 67a to 67f around it. The Teflon tube 69 is inserted through the large diameter hole 66, and the angle wire 64 and the SMA wire 65 are inserted through the small diameter holes 67a to 67f.

Further, as shown in FIGS. 27 and 28,
The angle wire 64 and the SMA wire 65 are connected to each other through an opening 70 opened by cutting out a part of the outer peripheral portion of the multi-lumen tube 68, and outside the multi-lumen tube 68 located in the opening 70. A high-frequency contraction tube 71 is fitted.

That is, when the high frequency contraction tube 71 is fitted to the outside of the multi-lumen tube 68 as shown in FIG. 27 and a high frequency is applied to the high frequency contraction tube 71, the diameter becomes small as shown in FIG. , Opening 70
To block. The connecting portion between the angle wire 64 and the SMA wire 65 is movable, and the connecting portion between the SMA wire 65 and the lead wire 72 is fixed by the caulking member 73.

Further, as shown in FIGS. 29 and 30, the connecting portion between the SMA wire 65 and the lead wire 72 is an opening portion 74 opened by cutting out a part of the outer peripheral portion of the multi-lumen tube 68. A crimp member 73, for example, a copper pipe, is crimped, and then a high-frequency contraction tube 75 is fitted to the outside of the multi-lumen tube 68 located in the opening 74, and a high frequency is applied to the high-frequency contraction tube 75 to contract it. The caulking member 73 is fixed so as not to move inside the multi-lumen tube 68.

In this way, the high frequency contraction tubes 71, 75
Is used. In the past, the same thing was done with the heat shrink tube, but by applying heat to the heat shrink tube to shrink it, the SMA wire 65 contracts due to the heat applied, and the SMA wire 65 is accurately aligned. There was a problem that the high frequency contraction tube 71,
By using 75, the above problems can be solved.

31 to 33 show a tenth embodiment,
Reference numeral 79 is an SMA catheter, which is composed of an insertion portion 80 formed of a multi-lumen tube, a bending portion 81, and a rigid tip portion 82. SMA catheter 79
The angle wire 83 is inserted through the distal end of the SMA catheter 79 and the SMA wire 84 is inserted through the rear end of the SMA catheter 79. Then, the angle wire 83 is pulled and the bending portion 81 is bent by heat-shrinking the SMA wire 84.

Here, the connecting portion between the angle wire 83 and the SMA wire 84 is the loop portion 83a provided at the rear end of the angle wire 83 and the folded portion 8 of the SMA wire 84.
4a is connected, but a length left over in the length direction of the angle wire 83 and the SMA wire 84 so that tension is not applied to the angle wire 83 and the SMA wire 84 (the remaining length is called a surplus length). ) And satisfying the margin length <the contraction length of the SMA wire, the tension is applied only to the angle wire 83 when the bending portion 81 is bent by electrically heating the SMA wire 84. The angle wire 83 and the SMA wire 84 are less likely to stretch, and the durability is improved.

34 and 35 show an eleventh embodiment, in which 85 is a side-viewing endoscope, and a channel 87 is provided in the insertion portion 86. Then, the catheter 89 is inserted through the forceps port 88 of the channel 87, and the side-view endoscope 85 is inserted.
The catheter 89 is projected from the tip of the body to allow observation and treatment inside the body cavity.

At this time, a stopper 90 is preliminarily provided at a position of a distance b from the distal end of the catheter 87 in consideration of the length a of the distal end of the catheter 89 protruding from the distal end of the side-view endoscope 85. It can be fixed to the outside of. That is, the stopper 90 is a ring-shaped rubber and can be fixed to the outside of the catheter 89 by a frictional force. It should be noted that by providing the stopper 90, the length a of the catheter 89 protruding outside the side-view endoscope 85 can be made accurate, and the SMA wire 91 provided inside the catheter 89 is always in the channel 87. Since it does not go outside, the SMA wire 9
It is not necessary to make a delicate adjustment of the amount of electricity supplied to 1.

According to the above-mentioned embodiment, the following constitution is obtained. (Supplementary Note 1) In a bending device that bends a bendable structure with a shape memory alloy that expands and contracts in the axial direction in response to a temperature change, a conversion unit that converts the shrinkage force of the shape memory alloy during heating into bending. The shape memory alloys are arranged in parallel at positions such that the bending directions of the shape memory alloys are substantially the same and the bending force amounts as outputs during heating of the shape memory alloys are different from each other, and the shape memory alloys having a large force amount are sequentially heated. A bending device provided with a control means for controlling. (Supplementary Note 2) The converting means is a joint structure having a rotating shaft and composed of a plurality of rotatably connected tubular members, and a plurality of the shape memory alloys are provided in parallel on one side of the rotating shaft. The bending device according to appendix 1, wherein: (Supplementary Note 3) The bending device according to Supplementary Note 1, wherein the rotating shaft is a rivet that connects the tubular members. (Supplementary Note 4) The bending device according to Supplementary Note 1, wherein the plurality of shape memory alloys have substantially the same transformation temperature. (Supplementary note 5) The bending device according to supplementary note 1, wherein the plurality of shape memory alloys have substantially the same displacement amount. (Supplementary note 6) The bending device according to supplementary note 1, wherein the plurality of shape memory alloys have a lower transformation temperature on the outside. (Supplementary note 7) The bending device according to supplementary note 6, wherein a plurality of the shape memory alloys are electrically connected in series. (Supplementary Note 8) The bending device according to Supplementary Note 1, wherein the structure is a flexible polymer material such as silicon, urethane, or Teflon. (Supplementary note 9) In a manipulator comprising a plurality of joints made of a plurality of tubular members each having a joint that is bendably connected and connected in the longitudinal direction, a shape memory alloy provided for each joint, and A manipulator characterized in that the arrangement position of the shape memory alloy is substantially the same at a position where the joint portion is divided into two on the joint portion, and the connecting portions in the joint portion are sequentially shifted by 180 °. (Supplementary note 10) The manipulator according to supplementary note 9, wherein the shape memory alloy is continuous in the longitudinal direction and is fixedly supported for each joint. (Supplementary Note 11) The connecting means of the connecting portion between the tubular members is
The manipulator according to note 9, which is a rivet. (Additional remark 12) The manipulator according to additional remark 9, wherein the tubular member and the connecting portion are pipe members in which a cutting depth is changed in a longitudinal direction of a superelastic alloy which is integral. (Supplementary note 13) The manipulator according to supplementary note 9, wherein the joint portion is configured such that the tubular members are fixedly supported by a rod-shaped member made of a superelastic alloy with a certain interval. (Supplementary Note 14) The manipulator according to Supplementary Note 9, wherein the tubular member and the rod-shaped member are joined by welding. (Appendix 15) The manipulator according to Appendix 9, wherein the tubular member and the rod-shaped member are joined by adhesion. (Appendix 16) The manipulator according to Appendix 13, wherein the tubular member is a metal such as stainless steel, a copper alloy, an aluminum alloy, a nickel alloy, and a titanium alloy. (Appendix 17) The tubular member is made of ceramic, Teflon,
14. The manipulator according to note 13, which is a nonmetal such as polypropylene or polyurethane. (Supplementary note 18) The manipulator according to supplementary note 9, wherein the joint portion is provided with a minute space member between the tubular members to connect the tubular member and the space member. (Additional remark 19) A through hole is provided in the tubular member and the space member, and the tubular member and the space member are connected by a linear wire member.
The described manipulator. (Supplementary note 20) Supplementary note 18 characterized in that the tubular member and the space member are connected by welding, adhesion, or the like.
The described manipulator. (Supplementary note 21) The manipulator according to supplementary note 18, wherein the space member is made of a nonmetal such as ceramic, Teflon, polypropylene, or polyurethane. (Supplementary note 22) The manipulator according to supplementary note 18, wherein the tubular member is a metal such as stainless steel, a copper alloy, an aluminum alloy, a nickel alloy, or a titanium alloy.

[0067]

As described above, according to the present invention,
By providing the shape memory alloys in parallel at positions where the bending force amounts as outputs during heating of the shape memory alloy are different, and controlling the heating sequentially from the shape memory alloys having a large force amount, a large bending amount can be obtained and There is an effect that it is possible to provide a bending device that can obtain a sufficient amount of force.

[Brief description of drawings]

1A and 1B show a first embodiment of the present invention, in which FIG. 1A is an overall configuration diagram of an endoscope, FIG. 1B is a plan view of an operation unit, and FIG. 1C is a sectional view of an insertion unit.

FIG. 2 is a schematic side view of a joint body that constitutes an insertion portion of the embodiment.

FIG. 3 is a transverse cross-sectional view of a joint body that constitutes the insertion portion of the embodiment.

FIG. 4 is a perspective view of a joint body that constitutes an insertion portion of the embodiment.

FIG. 5 is an explanatory view of the action of the joint body that constitutes the insertion portion of the embodiment.

FIG. 6 is a diagram showing a relationship between a bending angle and a bending holding force in the same embodiment.

FIG. 7 is an operation explanatory view of heating control of the same embodiment.

FIG. 8 is an explanatory view of the operation of the same embodiment.

FIG. 9 is an operation explanatory view of the same embodiment.

FIG. 10 is a transverse cross-sectional view of a joint body that constitutes an insertion portion according to the second embodiment of the present invention.

FIG. 11 is an overall configuration diagram of a small diameter endoscope according to a third embodiment of the present invention.

FIG. 12 is a perspective view of the insertion portion of the same embodiment.

FIG. 13 is a side view showing the tubular member connection structure according to the fourth embodiment of the present invention.

FIG. 14 is a perspective view of the tubular member of the embodiment.

FIG. 15 is a cross-sectional view of the tubular member of the same embodiment.

FIG. 16 is a perspective view of a joint body that constitutes the insertion portion of the embodiment.

FIG. 17 is an explanatory view of the operation of the insertion portion of the same embodiment.

FIG. 18 is a perspective view of a joint body that constitutes an insertion portion according to a fifth embodiment of the present invention.

FIG. 19 is a cross-sectional view of the insertion portion of the same embodiment.

FIG. 20 is a perspective view of a joint body showing a sixth embodiment of the present invention.

FIG. 21 is a cross-sectional view of the pipe member of the same embodiment.

FIG. 22 is a perspective view of a joint body showing a seventh embodiment of the present invention.

FIG. 23 is a longitudinal sectional side view of a catheter showing an eighth embodiment of the present invention.

FIG. 24 is a vertical sectional side view of a catheter showing a modified example of the eighth embodiment of the present invention.

FIG. 25 is a configuration diagram showing a distal end portion of a catheter showing a ninth embodiment of the present invention.

FIG. 26 is a cross-sectional view of the catheter of the same embodiment.

FIG. 27 is a vertical cross-sectional side view of the multi-lumen tube at the connection portion of the angle wire of the embodiment and the SMA wire.

FIG. 28 is a vertical cross-sectional side view of the multi-lumen tube at the connection portion of the angle wire of the embodiment with the SMA wire.

FIG. 29 is a vertical cross-sectional side view of the multi-lumen tube at the connection portion between the SMA wire and the lead wire in the example.

FIG. 30 is a vertical cross-sectional side view of the multi-lumen tube in the connecting portion between the SMA wire and the lead wire in the example.

FIG. 31 is a configuration diagram of a distal end portion of an SMA catheter showing a tenth embodiment of the present invention.

FIG. 32 is a side view of the connection portion of the angle wire of the embodiment with the SMA wire.

FIG. 33 is a side view of the connection portion of the angle wire of the embodiment with the SMA wire.

FIG. 34 is an overall configuration diagram of a side-viewing endoscope showing an eleventh embodiment of the present invention.

FIG. 35 is an overall configuration diagram of the catheter of the same embodiment.

FIG. 36 is a perspective view of a joint body that constitutes an insertion portion of a conventional endoscope.

FIG. 37 is a transverse sectional view of the joint body.

FIG. 38 is a transverse sectional view of the joint body.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Endoscope, 2 ... Insertion part, 3 ... Operation part, 4 ... Control part, 5
a to 5e ... Joint part, 6 ... Tip forming part, 7 ... Cylindrical member, 8
…Axis of rotation.

Claims (1)

[Claims] 1. A bending device for bending a bendable structure with a shape memory alloy that expands and contracts in the axial direction in response to a temperature change, and a conversion means for converting the shrinkage force of the shape memory alloy during heating into bending. The bending directions of the shape memory alloys are substantially the same, and the shape memory alloys are provided in parallel at positions such that the amount of bending force as an output during heating of the shape memory alloys is different,
A bending device provided with a control means for sequentially controlling heating from the shape memory alloy having a large force.