JPH08141971A - Manipulator - Google Patents

Abstract

PURPOSE: To provide a manipulator capable of producing large bending amount through a process of preventing a shape memory member from slipping in the bending operation, and capable of easily performing assembly of the shape memory member. CONSTITUTION: A manipulator formed by connecting structural bodies 5a to 5e provided with a plurality of joint parts in the longitudinal direction is provided with groove parts 14 formed on the outer surfaces of the structural bodies 5a to 5e, and extending along the longitudinal direction of the structural bodies 5a to 5e, shape memory members 11 arranged on the groove parts 14..., and a heating means 13 for heating the shape memory members 11, and for preventing the shape memory members 11 from slipping from the groove parts 14....

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a manipulator which is used by being inserted into a living body cavity, a duct or the like, and more particularly to a multi-joint manipulator which performs a bending motion with a plurality of joint bodies in multiple degrees of freedom.

[0002]

2. Description of the Related Art A shape memory alloy is arranged in a longitudinal direction of a structure formed by connecting a plurality of tubular members, and the shape memory alloy is deformed by heating the shape memory alloy to form the structure. Manipulators that perform a bending operation have been conventionally known. In this case, a method of mounting the shape memory alloy on the outer surface of the structure has been conventionally performed in order to improve the assemblability when disposing the shape memory alloy in the structure.

However, when the shape memory alloy is attached to the outer surface of the structure, the structure shown in FIG.
As shown in FIG. 3, the shape memory alloy b is largely separated from the structure a, which causes a disadvantage that the amount of bending cannot be large. Therefore, tubular guide means are provided on the structure at regular intervals, and the shape memory alloy is held by the guide means to prevent the shape memory alloy from separating from the structure during the bending operation.

[0004]

However, in the multi-joint manipulator, since the structure is long, the number of guide means provided on the structure is inevitably large. Therefore, the work of attaching the guide means becomes very difficult. Further, with a manipulator having a small diameter, it is very difficult to fix the guide means to the structure.

The present invention has been made in view of the above circumstances, and an object thereof is to prevent a shape memory member from being detached during a bending operation to obtain a large amount of bending and to have a shape memory. An object of the present invention is to provide a manipulator that can easily assemble members.

[0006]

In order to solve the above problems, the present invention provides a manipulator formed by connecting structures having a plurality of joints in a longitudinal direction, the manipulator being formed on the outer surface of the structure and having a structure. A groove extending along the longitudinal direction of the body; a shape memory member disposed in the groove; and heating means for heating the shape memory member and preventing the shape memory member from being separated from the groove. is there.

[0007]

In the above structure, when the shape memory member is heated by the heating means, the shape memory member is deformed, and the manipulator bends accordingly. At this time, the heating means prevents the shape memory member from being greatly separated from the structure. Therefore, a large bending angle can be efficiently obtained.

Further, since the shape memory member is arranged in the groove formed on the outer surface of the structure, the shape memory member can be assembled from the outside, and the assembling work is easy. Further, since the assembling property is good, the shape memory member can be easily arranged even in a small structure, so that the manipulator can be easily reduced in diameter.

[0009]

Embodiments of the present invention will be described below with reference to the drawings. 1 to 6 show a first embodiment of the present invention. FIG. 1A shows an endoscope as a manipulator. As shown in the figure, the endoscope 1 includes an insertion section 2, an operation section 3, and a control section 4,
The endoscope main body is configured by attaching the insertion portion 2 formed by connecting a plurality of bendable joint bodies 5a to 5e in series to the tip of the operation portion 3. At the tip of the insertion section 2, a tip forming section 6 in which an observation optical system, an illumination optical system, etc. are incorporated.
Is provided.

The structure of each of the joint bodies 5a to 5e is shown in FIG. Each of the joint bodies 5a to 5e is configured by rotatably connecting three tubular members 9 ... With rivets 10. A concave groove 14 is formed in the longitudinal direction of each tubular member 9. A shape memory alloy wire (hereinafter referred to as SMA wire) 11 that contracts when heated and returns to its original length when cooled (heat radiation) 11 is disposed in these grooves (recesses). In this case, both ends of each SMA wire 11 are fixed to the fixing member 1 fixed to the tubular member 9.
It is fixed at 2 by crimping.

A linear heater 13 is wound around each of the joint bodies 5a to 5e on the outer peripheral portion of the tubular member 9 ...
A space for accommodating and holding the SMA wire 11 is formed by the linear heater 13 and the groove 14 of the tubular member 9. 3 shows the SMA wire 11 and the linear heater 13.
It shows a cross section of the tubular member 9 in which and are arranged.

As shown in FIG. 4, the SMA wire 11 is
One joint body is provided for each of the joint bodies 5a to 5e, and a plurality of staggered bodies are provided in the longitudinal direction of the insertion portion 2. That is, the adjacent SMA wires 11 are arranged alternately (upper and lower positions in the figure) with the rivet 10, which is a rotating shaft, interposed therebetween. According to this configuration, in FIG. 1, for example, when the joint body 5a bends in the right direction (arrow direction) in the drawing, the next joint body 5b moves leftward, the next joint body 5c moves rightward, and the next joint body 5c moves rightward. The bending direction of each of the joint bodies 5a to 5e is different from the distal end side of the insertion portion 2 alternately, such as 5d to the left and the next joint body 5e to the right. You can

In FIG. 2, joint bodies 5a to 5e are shown.
Is drawn in a state where the SMA wire 11 and the linear heater 13 are exposed, but in reality, as shown in FIG. 3, the protective tube 21 is coated on the outside,
In addition, inside each of the tubular members 9 forming the joint bodies 5a to 5e, the light guide cable 15 for illumination and the light guide cable 15 for observation that are guided to the observation optical system and the illumination optical system provided in the distal end configuration unit 6 are provided. The image guide cable 16 and the like are inserted. In addition, a channel tube 17 through which a treatment tool can be inserted is also disposed inside the joint bodies 5a to 5e.

On the other hand, 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, as shown in FIG.
A view of the operation unit 3 viewed from above is shown in FIG. 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 of the endoscope 1 having the above structure 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 is turned on ((b in FIG. 1). You can press ()). Bending operation button 1
An operation signal is sent to the energization control unit 20 only while the ON side of 8a is pressed, and the energization control unit 20 energizes the linear heater 13 wound around the joint body 5a.
Give an order to. As a result, the heating amount of the linear heater 13 wound around the joint body 5a increases, the SMA wire 11 arranged on the joint body 5a contracts, and the joint body 5a bends. When the bending operation button 18a is released from the ON side when the required bending amount is reached, the energization of the linear heater 13 is controlled so that the bending state is maintained. Further, when it is desired to reduce the bending amount from this state, when the OFF side of the bending operation button 18a is pressed, the bending amount decreases only while the button is pressed, and when the bending amount is decreased to the predetermined bending amount, the OF is reduced.
When the F side is released, the reduced curved state is maintained. If you want to reduce the amount of bending and set the bending angle to 0,
It suffices to press the OFF side of the bending operation button 18a for a predetermined time.

An example of the bending operation state is shown in FIG. In order to bend the distal end portion of the insertion portion 2 slightly, the SMA wire 11 provided on the joint body 5a or the joint body 5b is used.
Can be heated. As a result, the distal end portion of the insertion portion 2 is curved in the DOWN direction as shown in (a) in the figure or is curved in the UP direction as shown in (b) in the figure.

When the SMA wires 11 arranged on the joint bodies 5a, 5c and 5e are heated at the same time, the entire insertion portion 2 is largely curved in the DOWN direction as shown in FIG.
Further, when the SMA wires 11 arranged on the joint bodies 5b and 5d are heated at the same time, the entire insertion portion 2 is largely curved in the UP direction as shown in FIG.

Other than the above, the joint bodies 5a-5
The curvature of e can be selected. For example, the insertion portion 2 is inserted into the curved conduit P as shown in FIG.
In the case of observing and treating, the insertion portion 2 can be bent as shown by simultaneously heating the SMA wires 11 arranged on the joint bodies 5a and 5d.

As described above, the endoscope 1 of this embodiment
Depending on the operation amount of the operation buttons 18a to 18e.
The wire 11 is heated and shrunk, the tubular members 9 ... Rotate around the rivet 10 as a pivot, and the joint bodies 5a to 5e bend. In this case, the operation buttons 18a to 18e are turned off.
When the FF side is pushed, the amount of heating to the SMA wire 11 is reduced, the temperature of the SMA wire 11 is lowered, and the bending of the SMA wire 11 due to the expansion of the SMA wire 11 and the elastic force of the insertion portion 2 which tries to return to a straight line. The corners are reduced. That is, the bending state of each joint body 5a to 5e can be skillfully controlled by selectively operating the operation buttons 18a to 18e, and a complicated operation is performed by combining the bending of each joint body 5a to 5e. be able to.

Further, in the endoscope 1 of the present embodiment, since the linear heater 13 regulates the detachment of the SMA wire 11 from the groove 14 of the tubular member 9, the SM is bent during the bending operation.
The A wire 11 does not largely separate from the tubular member 9 (see FIG. 34). Therefore, a large bending angle can be efficiently obtained.

Further, the endoscope 1 according to the present embodiment has a joint body 5
Since the structure of a to 5e is simple and it is not necessary to provide a guide means for arranging the SMA wire 11 as a separate member in the joint body, assembly work and component processing are easy. Further, the SMA wire 11 can be attached from the outside of the joint bodies 5a to 5e, so that the assemblability is good. Since the assemblability is good, the SMA wire 11 can be easily arranged even in the small joint bodies 5a to 5e.
It is also possible to reduce the diameter.

7 and 8 show a second embodiment of the present invention. This embodiment is a modification of the first embodiment.
That is, as shown in FIG. 7, one SMA wire 11 is provided for each of the joint bodies 5a to 5e as in the first embodiment, and the adjacent SMA wires 11 are pivots. Alternate across a rivet 10 (upper and lower positions in the figure)
Are located in Further, a thin film heater 22 is attached and fixed to the portion where the SMA wire 11 is located by an adhesive or the like so as to cover the groove 14 in which the wire 11 is arranged from above. In this case, each joint body 5a-5e
Then, the thin film heaters 22 are connected to each other by the wiring 23 (see FIG. 8). That is, the thin film heater 22 ...
Can be independently heated for each of the joint bodies 5a to 5e. The other structure is the same as that of the first embodiment.

Also in the case of this configuration, as in the first embodiment,
If the thin film heaters 22 ... Are heated and controlled independently for each of the joint bodies 5a to 5e, the SMA wire 1 is provided for each of the joint bodies 5a to 5e.
1 can be heat-shrunk. Therefore, the joint bodies 5a to 5e can be independently curved.

As described above, according to the structure of this embodiment, the SMA wire 11 can be held in the concave groove 14 of the tubular member 9 by the thin film heater 22 as in the first embodiment. During operation, the SMA wire 11 moves the tubular member 9
(See FIG. 34). Therefore, a large bending angle can be efficiently obtained. Also,
Since substantially the entire SMA wire 11 is covered with the thin film heater 22, the SMA wire 1 is different from that of the first embodiment.
The heating efficiency of 1 is good.

FIG. 9 shows a third embodiment of the present invention. This embodiment is also a modification of the first embodiment. As shown, a flexible tube 2 formed by weaving a linear resistor 24 as a heater for heating the SMA wire 11.
5 covers the outer peripheral portion of the tubular member 9. Linear resistor 24
As in the first embodiment, each SMA wire 11 can be heated independently. The rest of the configuration is similar to that of the first embodiment.

According to this structure, the flexible tube 25
However, since it plays a role of holding the SMA wire 11 in the concave groove 14 of the tubular member 9 and a role of the protection tube 21 shown in FIG. 3 of the first embodiment at the same time,
The number of members can be reduced as compared with the above embodiment.

10 to 12 show a fourth embodiment of the present invention. In this embodiment, as a modification of the first embodiment, the groove 1 that is concave in the longitudinal direction of the tubular member 9 is used.
Not only 4 is provided, but the notch 26 is formed by notching the base end of the tubular member 9 in a triangular shape.
Further, adjacent tubular members 9 are rotatably connected to each other by rivets 10, and the tip of the tubular member 26 located at the connecting portion has a small diameter portion 9a having a smaller diameter than other portions.
Has become. The tubular members 9 are connected to each other by fitting the narrowed small-diameter portion 9a into the base end portion of the tubular member 9 located in front thereof. In addition,
Although not shown, the SMA wire 11 is arranged in the concave groove 14 of the tubular member 9, and the SMA wire 11 is inserted into the concave groove 1.
Holding means 13, 22, and 24 for holding the inside of 4 are provided as in the first to third embodiments. The other structure is the same as that of the first embodiment.

In the above structure, when the SMA wire 11 is heated by the same operation as in the first embodiment, as shown in FIG. 11, the tubular member 9 turns around the rivet 10 as a turning shaft, and the tubular member. The notch 26 at the base end of 9 is expanded in the arrow direction in the figure by the rear tubular member 26 connected here. The deformed state of the cutout portion 26 is shown in FIG.
Is shown in. (A) is a state before change, (b)
Is in a state of being expanded by the bending operation.

In this structure, when the heating of the SMA wire 11 is stopped, each tubular member 9 is rotated about the rotation shaft 10 by the elastic force that tries to return to the original position of the cut portion 26, and the joint body is rotated. 5a (the same applies to 5b to 5e) is forcibly returned to a straight line. That is, the joint body 5a (the same applies to 5b to 5e) due to the elastic force generated by the tubular member 9 itself.
The curved state of can be released.

As described above, according to the structure of this embodiment, the tubular member 9 itself can be given a biasing force, so that the joint body 5a (same for 5b to 5e) is returned to the original straight state. In this case, the response speed becomes faster and the controllability is improved. That is, conventionally, the joint body 5a (similarly for 5b to 5e) is returned to the straight state by relying on the extension force of the SMA wire 11 and the elastic restoring force of the built-in body contained in the insertion section 2, or Although the elastic member such as a spring disposed inside the cylindrical member 9 is used forcibly, the structure of the present embodiment is
The joint body 5a (5b to 5b-) without relying on only the extension force of the SMA wire 11 or the elastic restoring force of the internal components in the insertion portion 2 and without providing an elastic member for increasing the diameter of the tubular member 9.
(5e is also the same), and the insertion part 2
It is also possible to reduce the diameter.

In this embodiment, the tubular member 9 may be made of a super elastic alloy. 13 and 14 show a fifth embodiment of the present invention. This embodiment is a modification of the fourth embodiment, and as shown in FIG.
An elongated slit 29 is formed at the base end of the.
Others are the same as those in the fourth embodiment.

In this configuration, S is the same as in the fourth embodiment.
When the MA wire 11 is heated and contracted and the tubular members 9 are rotated, the base end portion of the tubular member 9 in which the slit 29 is formed is expanded as shown in FIG. 14B. Further, when the heating of the SMA wire 11 is stopped, the base end portion of the tubular member 9 is returned to the original state as shown in FIG. 14 (a), so that the joint body 5a (the same applies to 5b to 5e). It is forcibly returned to a straight shape.

15 and 16 show a sixth embodiment of the present invention. In the configurations shown in the first to fifth embodiments, the SMA wire 11 is indirectly heated by the heater, but in the present embodiment, the SMA wire 11 is directly heated by energization. The configuration will be specifically described below.

In this embodiment, a structure 29 in which tubular members 9 having the same shape as in the first embodiment are connected by rivets 10.
Are manufactured by, for example, MIM (Metal Iujection Molding). And this structure 2
9 is divided into two as shown in FIG.
Then, the insulating member 30 having the same cross-sectional shape is provided between them, and the structures 29a and 29b and the insulating member 30 are joined by an adhesive, fusion bonding or the like to obtain the joint body 31. The insulating member 30
Is formed of electrically insulating material such as ceramic, acrylic, Teflon, hard rubber, plastic, or the like.

The outer surface of the structure 29 is covered with an insulating coating such as Teflon, ceramics, fluororesin, parylene, etc., and thereby the structure 2 is formed.
Electrical insulation on the surface of 9 is ensured.

In the joint body 31 having the above-mentioned structure,
One SMA wire 11 is arranged by utilizing the concave groove 14 of each tubular member 9, and this SMA wire 11 is fixed to the electrodes 33a and 33b fixed on the surfaces of both ends of the joint body 31. There is. A lead wire 34 is connected to the electrodes 33a and 33b, and the lead wire 34 is wound around the surface of the tubular member 9. Like the first embodiment, the lead wire 34 is connected to the control unit 4 so that the SMA wire 11 can be electrically heated. The rest of the configuration is the same as in the first embodiment.

In the joint body 31 having the above structure, when the SMA wire 11 is energized via the lead wire 34 by the signal of the control section 4, the SMA wire 11 is heated and contracted, and the tubular member 9 is riveted. It rotates about the position of 10 as a rotation axis. Therefore, the joint body 31 bends. At this time, the SMA wire 11 slides in the space formed by the recessed groove 14 and the lead wire 34 provided on the tubular member 9, but the SMA wire 11 is recessed by the lead wire 34 in the tubular member 9. Since it is held in the groove 14,
The SMA wire 11 is largely separated from the tubular member 9 (see FIG. 3).
4) never. Therefore, a large bending angle can be efficiently obtained.

By connecting the joint bodies 31 as described above, a complicated operation can be performed as in the first embodiment. As described above, the joint body 31 of this embodiment
Has an insulating coating on the surface of the structure 29, and the structures 29a and 29b are insulating members 30.
Since the electrodes are divided by the electrodes 33a and 33b,
Even if the insulation between the cylindrical member 9 and the cylindrical member 9 is no longer maintained, no current flows between the electrodes 33a and 33b except for the SMA wire 11. In addition, the joint body 31 of the present embodiment
Unlike the first to fifth embodiments, since the SMA wire 11 is directly heated, the heating efficiency is good and the responsiveness is good.

In this embodiment, the tubular member 9 may have the structure shown in FIGS. 17 to 20 show a seventh embodiment of the present invention. In the first to sixth embodiments, the shape memory alloy that expands and contracts according to the temperature change has been described as an example, but in the present embodiment, a shape memory alloy plate that exhibits a bent shape according to the temperature change will be described as an example. .

As shown in FIG. 17, two concave grooves 14 and 1 provided at the top and bottom along the axial direction of the elastic tube 35.
Shape memory alloy plates (hereinafter, referred to as SMA plates) 36a and 36b, each of which has a bent shape due to a temperature change and which becomes a linear shape when cooled, are arranged on each of the four plates. Thin film heaters 37a and 37a for holding the SMA plate 36a in the concave groove 14 and heating the SMA plate 36a and the SMA plate 36b in the concave groove 14 are provided in the concave grooves 14, 14 on the outer circumference of the elastic tube 35. A thin film heater 37b that holds and heats the SMA plate 36b is attached and fixed. The thin film heaters 37a and 37a and the thin film heater 37b are provided with the wiring 3 respectively.
A thin film heater 37a, 37a and a thin film heater 37b can be independently heated and controlled via a controller 8 (not shown). In this case, the wiring 3
8 is wound around the outer circumference of the elastic tube 35.

Here, the S arranged on the elastic tube 35
MA plates 36a, 36b and thin film heaters 37a, 37a, 3
The positional relationship with 7b will be described. SMA plate 36a
As shown in (a) of FIG. 18, the bending shape is memorized at two places on both sides, and the thin film heaters 37a and 37a are provided at the portions where the bending shape is memorized. Also,
As shown in FIG. 18B, the SMA plate 36b is shaped and memorized so that its central portion is largely bent, and the thin film heater 37b is provided at this central portion. That is,
As shown in FIG. 19, the SMA plates 36a and 36b are arranged in parallel with their bent and memorized portions displaced from each other, and accordingly, the thin film heaters 37a and 37b.
The a and 37b are also displaced. Although only one joint is shown in this example, the elastic tube 35
By providing a plurality of SMA plates 36a and 36b in the upper longitudinal direction, a multi-joint structure can be obtained. Further, as another means for achieving the multi-joint structure, a connecting body formed by connecting a plurality of SMA plates in the longitudinal direction is provided in parallel above and below a long elastic tube, and is arranged above and below. It is also conceivable that the bent and memorized portions are alternately displaced by the connected bodies. Also in this case, the thin film heater can be selectively heated.

Further, the above-mentioned SMA plates 36a, 36b
Is bidirectional, but may be unidirectional. When the elastic tube 35 is unidirectional, the elastic tube 35 returns to the linear shape by the elastic force of the elastic tube 35 itself.

Next, the operation of the manipulator having the above structure will be described with reference to FIG. First, through the wiring 38, the thin film heater 37a arranged on the SMA plate 36a,
When 37a is heated, as shown in FIG.
Both sides of the MA plate 36a are bent, and the elastic tube 35 is bent in the DOWN direction in the drawing. When the thin film heater 37b is heated, as shown in FIG.
The central portion of 6b is bent, and the elastic tube 35 is bent in the UP direction in the figure.

In such a bending operation, the characteristic structure of this embodiment in which the SMA plates 36a and 36b, which are linear plate members, are arranged in parallel vertically is significant.
Regarding this point, see the conventional configuration shown in FIG.

In FIG. 21, the SMA plates 39a and 39b, which have a curved shape as a whole with substantially concentric curvatures, are arranged in parallel above and below the elastic tube to bend the elastic tube in the vertical direction. In this case, S
When the MA plate 39a is heated by the heater 40a, this heat is applied to the SMA plate 39a on the other side in parallel.
It is transmitted to the board 39b. Therefore, the SMA plate 39
When a is to be bent downward, the SMA plate 39
There is an inconvenience that b is slightly bent upward, which is the opposite direction. That is, the upward bending force of the SMA plate 39b becomes a resistance, and the SMA plate 39a cannot be bent sufficiently downward. The SMA plate 39b whose shape before heating is already curved upward
Is further curved in the upward direction, the bending operation of the SMA plate 39a that tends to be curved in the downward direction is limited.

On the other hand, in this embodiment, the thin film heater 3
Even if electricity is supplied to 7a and 37a, the thin film heaters 37a and 3a
Since the portion of the SMA plate 39b facing the 7a has a linear shape, even if the heat from the thin film heaters 37a, 37a is transmitted to this portion to some extent, the SMA plate 39b will bend from the straight line state, so that its curvature Small quantity, SM
There is no great resistance to the bending operation of the A plate 39a.

As described above, in this embodiment, a large bending amount can be efficiently obtained, and the SMA can be obtained.
Heaters 37a, 37a, 3 for heating the plates 36a, 36b
Since 7b is provided only on the bent portions of the SMA plates 36a, 36b, the heaters 37a, 37a, 37b need not be made larger than necessary. Therefore, the bending control can be performed with a small electric power, and the manipulator can be downsized and its diameter can be reduced.

22 and 23 show an eighth embodiment of the present invention. As shown in FIG. 22, a plurality of SMA plates 44 are arranged above and below the elastic tube 35 along the longitudinal direction of the elastic tube 35 at regular intervals. A bending shape is stored in the center of each SMA plate 44. A heater 45 for heating is provided near the center of each SMA plate 44. In this case, as shown in the figure, the SM arranged above the elastic tube 35
The gap C between the A plates 44 is the SMA plate 4 arranged on the lower side.
4 is opposed to the heater 45. Of course, the gap C between the SMA plates 44 arranged below the elastic tube 35 is also
It faces the heater 45 on the SMA plate 44 arranged on the upper side. Further, the SMA plate 44 is fixed to the elastic tube 35 by a linear member 46 such as a Kepler or cotton thread.

A heater 45 for heating the SMA plate 44
The heating is controlled independently of each other. In the above-described configuration, for example, when the leading edge heater 45a arranged below the elastic tube 35 is heated, the lower leading edge SMA plate 44a bends and the tip of the elastic tube 35 is bent, as shown in FIG. Curved upwards. At this time, SM
At a position on the opposite side facing the curved portion of the A plate 44a, S
Since the gap C formed between the MA plate 44b and the SMA plate 44c exists, the elastic tube 35 can be bent without resistance. In this way, a complicated operation can be performed by controlling the heating to each SMA plate 44.

As described above, according to the structure of this embodiment, the bending down does not occur. When the SMA plate is arranged in this way to form a multi-joint structure, there is generally a problem that the elastic tube becomes long. However, this problem is caused by the gap C within a range in which bending down does not occur.
It can be easily solved by making as small as possible.

24 and 25 show a ninth embodiment of the present invention. In the first embodiment, one joint is oscillated (bent in one direction) and the joints are alternately changed in direction to increase the degree of freedom. However, in this embodiment, the shape expands and contracts due to temperature change. It is intended to perform both swings (bending in two directions) at one joint using a memory alloy wire.

As shown in FIG. 24, the joint bodies 5a to 5e.
Is formed by rotatably connecting a plurality of tubular members 9 ... With rivets 10. This is described in the first embodiment. In each joint body 5 a to 5 e, the concave groove 14 of the tubular member 9 is used to move the SMA wire 41 to the upper and lower positions.
a and 41b are provided. This SMA wire 41
It is memorized that a and 41b contract when heated and expand when cooled. Both ends of the SMA wires 41a and 41b are fixed to the joint bodies 5a to 5e via the fixing member 12. In addition, as shown in FIG. 25, the rear half of the SMA wire 41a and the front half of the SMA wire 41b (the hatched portion in the figure) do not contract even when heated, for example, by overheating or by an external force. Is added to cause plastic deformation. The wiring 13 is the SMA wire 41.
25, the wires 13 are wound around the outer circumferences of the joint bodies 5a to 5e (cylindrical members 9 ...) As in the first embodiment.

In this structure, first, when SW1 is closed,
The electric current flows through the front half of the SMA wire 41b and the front half of the SMA wire 41a, but does not flow into the rear half of the SMA wire 41b and the rear half of the SMA wire 41a. Therefore, the front half of the SMA wire 41a and the SMA wire 41a
The first half of b is heated. At this time, the SMA wire 41b
The first half of S does not react to heating because it is plastically deformed, and S
Only the front half of the MA wire 41a contracts. Therefore, the joint bodies 5a to 5e are curved in the UP direction in the figure. In this case, if the SMA wire 41b is provided with slack necessary for bending the joint bodies 5a to 5e, the joint bodies 5a to 5e
The SMA wire 41b does not become a resistance against the bending of e in the UP direction.

In order to bend the joint bodies 5a to 5e in the DOWN direction in the figure, SW2 may be closed and the rear half of the SMA 41a and the rear half of the SMA 41b may be energized. As a result, the rear half of the SMA wire 41b contracts.

As described above, according to the structure of this embodiment, the thermal interference can be reduced even if the diameter is reduced, and moreover, it is possible to bend in two directions (both swings) with one joint. FIG. 26 shows the first of the present invention.
0 shows an example of 0. This embodiment is a modification of the ninth embodiment. That is, in the ninth embodiment, the SMA
Although the wires 41a and 41b are heated by energization, in this embodiment, the SMA wires 41a and 41b are heated by the heater.

Therefore, as shown in FIG. 26, the thin film heater 42a and the thin film heater 42b are provided for each of the joint bodies 5a to 5e.
Are arranged vertically offset from each other, and the front half of the SMA wire 41a and the rear half of the SMA wire 41b can be independently heated. The other structure is the same as that of the ninth embodiment.

In this structure, when the heater 42a is heated, the front half of the SMA wire 41a is heated and contracts, so that the joint bodies 5a to 5e bend in the UP direction in the figure. At this time, even if the heat of the heater 42a is transmitted to the front half of the SMA wire 41b, the front half of the SMA wire 41b is plastically deformed and therefore does not contract. Therefore, the SMA wire 4
SMA wire 41b against bending motion associated with deformation of 1a
The first half of is not resistant.

In the present embodiment, the heaters 42a, 42a
The shape of b may be cylindrical. The shape is shown as heaters 43a and 43b in FIG. Hereinafter, a method for connecting the SMA wire and the lead wire will be described.

It is generally said that mechanical caulking is good when connecting dissimilar metals to the shape memory alloy. However, there is a drawback that the diameter becomes large, and it is necessary to make the diameter as small as possible. The method will be described below.

As shown in FIG. 28, a notch 47a is provided in the center of the pipe member 47, and the deformed SMA wire 48 and the lead wire 49 are connected to the pipe member 47. In this manufacturing method, as shown in FIG. 29 (a), the SMA wire 4
After passing through 8, the end portion of the SMA wire 48 is flatly crushed as shown in FIG. 29 (b) (in the figure, the crushed portion is 48a.
Indicated by. ). Alternatively, the end portion of the SMA wire 48 is melted into a spherical shape and then put into the cutout portion 47a.
This prevents the SMA wire 48 from coming off the pipe member 47. In this state, a part of the pipe member 47 is further lightly crushed and caulking is performed. Furthermore, FIG.
As shown in (c) of FIG. 9, caulking is performed by passing the lead wire 49 through the pipe member 47 from the opposite side. Finally, FIG.
As shown in (d), the solder 50 is embedded in the cutout portion 47a to make the outer diameter of the pipe member 47 uniform.

Next, another method for disposing the SMA actuator on the structure will be described. In the method described above, S
The SMA actuator was held, that is, guided by winding a heater or a lead wire for heating the MA actuator around the structure. However, in the method described below,
It is intended to hold the SMA actuator by providing the guide means separately.

FIG. 30 is a perspective view of the manipulator.
The manipulator 101 has a plurality of independently operating curved portions 102 in the longitudinal direction. The curved portion 102 is
The inner tube 105 is inserted through the inside of the structure formed by connecting the ring-shaped members 103 with the coil springs 104. The SMA actuator 10 is provided along the tube 105 between the ring-shaped members 103.
6 are provided. One end of the SMA actuator 106 is adhesively fixed to the ring-shaped member 103.
A thin film heater 107 for heating SMA is attached to the surface of 106. A lead wire (not shown) is extended from the heater 107, and the lead wire is connected to a control device (not shown) provided on the base end side of the manipulator 101.

As shown in FIG. 32B, the SMA actuator 106 is constructed by laminating a plurality of thin SMA plates 108, and each SMA plate 108 is called bidirectional or omnidirectional. It is formed of a NiTi-based shape memory alloy having characteristics.
This is a characteristic of spontaneously and reversibly deforming into different shapes on the high temperature side and the low temperature side at the boundary of the phase transformation temperature. Figure 31
31A shows the state before the deformation of the SMA plate 108, and FIG. 31A shows the state after the deformation of the SMA plate 108.

When the SMA actuator 106 bends, each SMA plate 108 slides relative to the bending, so that the frictional force at that time does not hinder the bending operation.
09 is coated. And Teflon 10
9, the SMA plates 108 are stacked one above the other and fixed to the ring-shaped member 103 with one end aligned. Further, the coil spring 104 has a large and small coil diameter for each pitch, and the actuator 106 is inserted into the gap of the coil spring 103.

With such a structure, when the heater 107 is energized to heat any SMA actuator 106, the SMA plate 108 bends as shown in FIG. 31, so that the manipulator 101 can be varied depending on the selection of the heater and the control of the amount of heat. Take different forms of operation.

In the prior art, one SMA with a large wall thickness
Since the bending portion was driven, the bending angle cannot be made large if the surface strain is kept within the deformation limit of the SMA. In contrast,
In this configuration, since the SMAs are laminated, the thickness of each SMA is small. Even if the same bending angle as in the conventional case is obtained, the surface strain is very small. Therefore, it is possible to operate up to a large bending angle.

Further, the number of laminated layers can be increased in order to obtain the same level of strength as the conventional one. In this case, in this configuration, the guide means by the coil spring 104 is provided so that the SMA plate can slide easily. Further, a lubricating means by Teflon coating is provided so that the amount of bending force is not lost due to sliding resistance during sliding. The coating agent is not limited to Teflon, but S
Any polymer that can be coated on the MA surface and has appropriate lubricity may be used.

Further, in FIG. 32, three SMA plates 108 are laminated. One of the S
Grooves 112 are formed on the surface of the MA, and the groove 112 is coated with lubricating oil. As the lubricating oil, any grease such as grease or silicone oil may be used. The guide means may be tied with a sheet 110 made of an elastic material having good extensibility such as rubber as shown in the figure.

A thin film heater may be sandwiched between the laminated SMA plates 108. Also in this case, the surfaces of the SMA plate and the heater are coated with Teflon so that they can slide easily. With this configuration, the heat of the heater is efficiently conducted to the SMA, so that the response is improved. In addition, power consumption can be reduced. Also,
The SMA plate may be manufactured in multiple layers by forming an SMA thin film by a sputtering method.

The configurations described above can provide various configurations shown in the following paragraphs. 1. In a manipulator formed by connecting structures having a plurality of joints in a longitudinal direction, a groove formed on an outer surface of the structure and extending along the longitudinal direction of the structure, and a shape memory member arranged in the groove. And a heating unit that heats the shape memory member and prevents the shape memory member from being detached from the groove portion.

2. The manipulator according to the first aspect, wherein the heating means is a linear heater spirally wound around the outer peripheral surface of the structure. 3. The manipulator according to claim 1, wherein the heating means is a thin-film heater attached along the groove of the structure.

4. The manipulator according to the first aspect, wherein the heating means is a composite of a linear heater and an elastic tube that are coated on the outer peripheral surface of the structure. 5. The heating means includes a thin film heater attached along the groove of the structure, and a lead wire electrically connected to the thin film heater and spirally wound around the outer peripheral surface of the structure. The manipulator according to the first item.

6. The manipulator according to claim 1, wherein the structure is configured by rotatably connecting a plurality of tubular members. 7. The manipulator according to the sixth aspect, wherein the tubular member is provided with a deformable portion that elastically deforms as the tubular member rotates.

8. The manipulator according to the first aspect, wherein the structure is made of a tube member having elasticity. According to the configurations of the sixth to eighth aspects, it is possible to add a bias force to improve the operability, and the manipulator can have a small diameter.

Conventionally, when a shape memory alloy is placed in a structure to perform a bending operation, the structure is bent by the generated force of the shape memory alloy during heating, and the shape memory alloy is cooled when returning the curve to a straight line. However, the force generated at this time is small. Therefore, in order to increase the returning force, a spring means such as a coil spring or a leaf spring is added as an elastic force. However, in this case, it is necessary to provide a spring means for generating an elastic force in a part or the whole of the structure. In particular, when the manipulator has a small diameter, if a spring means is provided in the internal space of the structure, other built-in objects will not enter and it is difficult to add functions such as an observation function and an illumination function. However, such inconvenience does not occur according to the configurations of the sixth to eighth aspects.

9. The shape memory member is a shape memory alloy that expands and contracts due to temperature change, and a plurality of shape memory alloys are provided in the longitudinal direction, and the shape memory alloy is provided with control means capable of independently heating and controlling the shape memory alloy. The manipulator according to item 1.

10. 10. The manipulator according to item 9, wherein the bending directions of the plurality of shape memory alloys are alternately shifted by about 180 °. 11. The shape memory member is a shape memory alloy in which a bent shape is memorized by a temperature change, and a plurality of the shape memory alloys are provided in the longitudinal direction, and the shape memory alloy is provided with a control means capable of independently controlling heating. The manipulator according to the first item.

12. The shape memory member is a shape memory alloy having a shape having alternating bent portions and straight portions due to temperature change, and the shape memory alloys are arranged in parallel with each other so that the bent portions are offset from each other. 13. The manipulator according to item 1, wherein a heater is provided. The shape memory alloy includes a first shape memory alloy having a bent shape at a central portion, a second shape memory alloy having both ends having a bent shape, and a first shape memory alloy and a second shape memory alloy. 13. The manipulator according to item 12, which is provided in parallel.

According to the constructions of the twelfth and thirteenth terms, the structure can be made as short as possible even if the manipulator has a small diameter, and moreover, it is possible to bend in both directions. Conventionally, a bent shape memory alloy plate is arranged on a structure, and the structure is curved by heating the shape memory alloy plate with a heater. In this case, in order to bend the structure in both directions (two directions), the shape memory alloy plates are arranged in parallel so that the bending directions are different, and the heating of the shape memory alloy plates is switched to perform bending in both directions. There is. However, when the structure has a small diameter, the shape memory alloy plates placed in parallel with each other are close to each other, and when one of the heaters is heated, heat is transferred to one of the shape memory alloy plates and is not curved. The shape memory alloy plate of will also bend a little. Therefore, it is difficult to increase the curvature contrary to the bending on the opposite side, and the curvature is considerably lowered. However, according to the configurations of the 12th and 13th terms, such an inconvenience does not occur.

14. In a manipulator in which a structure having a plurality of joints is connected in the longitudinal direction, a groove portion having a concave shape in the longitudinal direction of the surface of the structure, a shape memory alloy arranged in the groove portion, and for electrically heating the shape memory alloy And a conducting wire wound around the outer peripheral surface of the structure.

15. The structure comprises a first cylindrical member having an insulating property in an intermediate portion and a second cylindrical member made of a metal, and is formed as a composite structure having an insulating film having an electrically insulating property on a surface of the metal. 15. The manipulator according to Item 14, characterized in that

16. 16. The manipulator according to Item 15, wherein the first cylindrical member is ceramics, Teflon, urethane or the like, and the second cylindrical member is stainless steel, aluminum, aluminum alloy, copper alloy or the like.

17. An endoscope in which the insertion portion has a plurality of curved portions, wherein the curved portion has the configuration of items 11 to 16. According to the configurations of items 14 to 16, even if the insulating coatings at both end portions of the shape memory alloy are broken, the function of causing the bending operation can be secured, and in practice, the structure and the shape memory alloy are It is possible to reliably insulate the spaces.

Conventionally, the structure is curved by arranging a shape memory alloy that expands and contracts due to temperature change, and heats the shape memory alloy to shrink it. in this case,
When the structure body is made of metal, it is known that the shape memory alloy and the structure body are coated with parylene, ceramics, fluororesin or the like as electrical insulation. However, during the bending operation, a force is exerted on the structure at both ends of the shape memory alloy, and the coating strength at this portion is questionable. If the coating is broken, a current will flow through the structure when both ends of the shape memory alloy are energized, causing a problem that the shape memory alloy cannot be heated as expected. However, according to the configurations of the 14th to 16th terms, such inconvenience does not occur.

18. In a manipulator consisting of a flexible tubular body and a shape memory alloy actuator provided along the flexible tubular body, the shape memory alloy actuator comprises:
A manipulator which is formed by stacking shape memory alloy plates that have been bent and memorized, and each shape memory alloy plate is slidably connected to each other by a connecting means and a friction reducing means.

19. 19. The manipulator according to item 18, wherein the friction reducing means is formed by coating or coating a surface of a shape memory alloy plate with a lubricant that reduces friction during sliding.

20. 20. The manipulator according to Item 19, wherein the lubricant is a polymer. 21. 21. The manipulator according to item 20, wherein the high-molecular polymer is Teflon or parylene.

22. A recess for storing a lubricant is formed on the surface of the shape memory alloy plate.
The manipulator according to item 9. 23. 20. The manipulator according to Item 19, wherein the lubricant is fine powder.

24. 20. The manipulator according to Item 19, wherein the lubricant is oil. According to the configurations of items 18 to 24, it is possible to secure a necessary amount of force as a manipulator for working in a pipe and obtain a large bending amount.

Conventionally, Japanese Patent Application No. 6-42967 discloses an articulated manipulator in which an SMA plate and a flexible tubular body are combined. In this specification, S
Since the technical idea of making the MA plate multi-layered is not shown, it is necessary to increase the thickness of the plate in order to obtain a practical ability, and then the surface strain of the plate at the time of bending becomes large. As a result, the bending angle cannot be increased. Further, Japanese Patent Laid-Open No. 61-255669 discloses a curved catheter in which an SMA plate is slidably provided on a flexible tubular body. Even in the case of the configuration disclosed here, the bending angle cannot be increased. Further, Japanese Patent Laid-Open No. 61-150678 discloses that
A curved actuator having a Peltier element sandwiched between a plurality of SMA plates is shown. In this precedent, SMA
Since the plate is attached via the Peltier element, it does not slide, and as a result, the surface strain during bending is determined by the laminated thickness. Therefore, the problems described above occur. However, these problems are solved by the constitutions of items 18 to 24.

[0091]

As described above, according to the manipulator of the present invention, a large amount of bending can be obtained by preventing the shape memory member from being detached during the bending operation, and the shape memory member can be easily assembled. Can be done.

[Brief description of drawings]

FIG. 1A is an overall configuration diagram schematically showing an endoscope as a manipulator according to a first embodiment of the present invention,
(B) is a plan view of the operation unit of the endoscope of (a).

FIG. 2 is a perspective view showing in detail a configuration of an insertion portion of the endoscope shown in FIG.

3 is a vertical cross-sectional view of a tubular member that constitutes the insertion portion of FIG.

FIG. 4 is a schematic side view of a joint body that constitutes the insertion portion of FIG.

5 is a diagram showing a bending mode of an insertion portion of the endoscope of FIG.

FIG. 6 is a diagram showing another bending mode of the insertion portion of the endoscope of FIG.

FIG. 7 is a schematic side view of a joint body that constitutes a manipulator according to a second embodiment of the present invention.

8 is a perspective view showing in detail a configuration of an insertion portion of the endoscope shown in FIG.

FIG. 9 is a perspective view showing in detail a main part configuration of a manipulator according to a third embodiment of the present invention.

FIG. 10 is a perspective view schematically showing a main configuration of a manipulator according to a fourth embodiment of the present invention.

11 is a diagram showing a bending mode of the manipulator of FIG.

12 is a diagram for explaining a deformed state of a base end portion of a tubular member that constitutes the manipulator of FIG.

FIG. 13 is a perspective view schematically showing a main part configuration of a manipulator according to a fifth embodiment of the present invention.

FIG. 14 is a diagram for explaining a deformed state of a base end portion of a tubular member that constitutes the manipulator of FIG.

FIG. 15 is a perspective view showing in detail a main part configuration of a manipulator according to a sixth embodiment of the present invention.

16 is a diagram for explaining a manufacturing method of the manipulator of FIG.

FIG. 17 is a perspective view showing in detail a main part configuration of a manipulator according to a seventh embodiment of the present invention.

18 is an SMA arranged in the manipulator of FIG.
It is a figure which shows the deformation characteristic of a board.

19 is an SMA arranged in the manipulator of FIG.
It is a figure which shows the arrangement | positioning state of a board.

20 is a diagram showing a bending mode of the manipulator of FIG.

FIG. 21 is an explanatory diagram for explaining a deformed state of a conventional SMA plate.

FIG. 22 is a side view schematically showing a main part configuration of a manipulator according to an eighth embodiment of the present invention.

FIG. 23 is a diagram showing a bending mode of the manipulator of FIG. 22.

FIG. 24 is a perspective view schematically showing a main part configuration of a manipulator according to a ninth embodiment of the present invention.

25 is an SMA arranged in the manipulator of FIG. 24.
It is a circuit diagram which shows the wiring circuit of a wire roughly.

FIG. 26 is a perspective view schematically showing a main part configuration of a manipulator according to a tenth embodiment of the present invention.

27 is a perspective view showing a modified example of the manipulator of FIG. 26. FIG.

FIG. 28 is a perspective view showing an SMA wire, a lead wire, and a pipe member connecting them.

FIG. 29 is a diagram showing a method of connecting an SMA wire and a lead wire using the pipe member of FIG. 28.

FIG. 30 is a perspective view of a preferred manipulator.

31 is an SMA provided on the manipulator of FIG. 30.
It is a figure which shows the deformation state of the SMA board which forms an actuator.

32 is an SMA provided in the manipulator of FIG. 30.
It is a figure which shows the assembling method of an actuator, and a bending operation state.

FIG. 33 is a diagram showing a modification of the SMA actuator that constitutes the manipulator of FIG. 30.

FIG. 34 is a diagram showing a bending operation mode of a conventional manipulator.

[Explanation of symbols]

5a to 5e ... Joint body (structure), 11 ... SMA wire (shape memory member), 13 ... Linear heater (heating means), 3
6 ... SMA plate (shape memory member).

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Office reference number FI technical display location G02B 23/24 A

Claims (1)

[Claims] 1. A manipulator formed by connecting structures having a plurality of joints in a longitudinal direction, wherein a groove formed on an outer surface of the structure and extending along the longitudinal direction of the structure is provided in the groove. And a heating means for heating the shape memory member and preventing the shape memory member from being separated from the groove portion.