JPH07120684A - Multijoint flexible tube - Google Patents

Abstract

PURPOSE:To provide a multijoint flexible tube capable of sufficiently obtaining a required curve angle without adding an excessive load even when the outer diameter of the flexible tube is narrowed. CONSTITUTION:The multijoint flexible tube has a first connected body 8a formed by connecting, in the longitudinal direction of a flexible tube body 10, a plurality of shape memory wire pairs 19 constituted by connecting two shape memory wire rods 12, 13 different in transformation temperature, and having both ends 14 fixed to a joint body 11, the connecting part 15 of the two shape memory rods 12, 13 being movable in the longitudinal direction of the flexible tube body 10, a second connected body 8b formed by connecting, in the position opposite to the first connected body 8a, the shape memory wire pairs 19 in the longitudinal direction of the flexible tube body 10, and a heating means for selectively heating each shape memory wire rod 12, 13, and the second connecting body 8b is arranged to the first connecting body 8a in such a manner that the transformation temperatures of the mutually opposed shape memory wire rods of the first connecting body 8a and the second connecting body 8b are differed from each other.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a flexible tube which is used by being inserted into a duct or the like in a living body cavity, and in particular, it has a multi-joint body capable of performing a bending operation with multiple degrees of freedom. The present invention relates to a flexible joint tube.

[0002]

2. Description of the Related Art Conventionally, flexible tubes such as medical catheters and endoscopes, or flexible tubes of industrial endoscopes for inspecting and repairing industrial pipelines such as gas pipes have been used. Some have a plurality of bent portions and can perform a bending operation with multiple degrees of freedom.

That is, such a flexible tube is provided with a flexible tube body formed by connecting a plurality of joint bodies so as to be rotatable relative to each other in the longitudinal direction, and inside the flexible tube body, in response to a temperature change. A shape memory wire whose length is contracted / extended is arranged.
When the shape-memory wire rod is expanded / contracted by electrically heating the bending operation wire, each joint body is rotated so that the bending operation of the flexible tube body can be performed. Thus, the tip of the flexible tube can be made to face the target site.

An example of the structure of such an articulated flexible tube is shown in FIG.
Is shown in. The flexible tube main body that constitutes the multi-joint flexible tube is composed of a plurality of joint bodies that are rotatably connected to each other in the longitudinal direction, but only one joint is shown in FIG. As shown, these joint bodies 6 that form the joints
Reference numerals 2 and 62 have a cylindrical shape, and are rotatably connected to each other via a rotation shaft 64. Joint body 62,62
A plurality of through holes 66 extending in the longitudinal direction are formed at equal angular intervals in the circumferential direction. The shape memory wire 63 is arranged in each of the two axially symmetrical through holes 66, 66 facing each other. This shape memory wire 63
Is disposed so as to straddle two joint bodies 62, 62, and both end portions of each joint body 62,
It is fixed to 62.

When the joint portion having such a structure is bent in one direction, one shape memory wire rod 63 arranged in the joint body 62, for example, the shape memory wire rod 63 located on the upper side in the drawing is heated. Just shrink it. As a result, each joint body 6
When the reference numerals 2, 62 receive the contracting force of the shape memory wire 63, they rotate about the rotation shaft 64 and bend upward. When the joint portion is bent in the opposite direction, the other shape memory wire rod 63, that is, the shape memory wire rod 6 located on the lower side in the figure.
It suffices to heat 3 to shrink it. That is, in the multi-joint flexible tube as shown in FIG. 20, one joint can bend in two directions.

[0006]

By the way, in an endoscope that is inserted into a narrow conduit, it is necessary to make the outer diameter of the flexible tube that is the insertion portion as small as possible. In this case, of course, FIG.
The outer diameter of the joint body 62 shown in FIG. 0 also becomes thin, and accordingly, the through holes 66 of the joint body 62 come close to each other, and the through hole 6
Two shape memory wire rods 6 respectively arranged in 6, 66
3,63 Comrades will come closer. Therefore, the heat applied to the one shape memory wire 63 is applied to the other shape memory wire 6
The inconvenience of being transmitted to 3 also occurs.

That is, taking the joint structure shown in FIG. 20 as an example, when the upper shape memory wire rod 63 is heated in order to bend the joint portion upward, this heat is applied to the upper shape memory wire rod 63 so that it is in contact with the upper shape memory wire rod 63. The shape memory alloy 63 on the side is also transmitted and the shape memory alloy 63 on the lower side is also heated,
The contraction of the shape memory wire 6 on the upper side restricts the movement of the joint portion that tends to bend upward, and the contraction of the shape memory alloy 63 on the lower side restricts the movement of the joint part. Similarly, when the joint portion is to be bent downward, the contraction of the lower shape memory wire 6 causes the movement of the joint portion that is about to bend downward due to the contraction of the upper shape memory alloy 63. The phenomenon of being regulated occurs.

In such a state, the joint cannot be bent as desired, and an extra load is applied to the rotary shaft 44. The present invention has been made in view of the above circumstances, and an object thereof is to sufficiently obtain a desired bending angle without applying an extra load even when the outer diameter of the flexible tube is reduced. An object is to provide a multi-joint flexible tube that can be used.

[0009]

In order to solve the above-mentioned problems, the present invention provides a flexible tube body composed of a plurality of joints rotatably connected to each other in the longitudinal direction with a shape memory wire which expands and contracts due to temperature change. Two shape memory wire rods having different transformation temperatures in a multi-joint flexible tube that is disposed and that causes each joint body to rotate by expanding and contracting the shape memory wire rod to bend the flexible tube body. A plurality of shape memory wire pairs that are connected to each other and are fixed to the joint body at both ends thereof, and that the connecting portion of the two shape memory wire rods are movable in the longitudinal direction of the flexible tube body. A first connecting body formed by connecting in the longitudinal direction of the flexible tube body and a second connecting body formed by connecting the shape memory line pair in the longitudinal direction of the flexible tube body at a position facing the first connecting body. And the shape memory wire rods are selectively heated. Comprising a heat means, the first coupling member second coupling member to transformation temperature is different from the shape-memory wire and a second connecting member of the shape memory wire facing each other 1
A multi-joint flexible tube characterized in that it is arranged with respect to a connected body.

[0010]

Function: A shape memory wire pair is formed by connecting two shape memory wire rods having different transformation point temperatures, and the connecting portion of the two shape memory wire rods having different transformation point temperatures is the longitudinal direction of the flexible tube body. Since the shape memory wire pair is arranged and fixed to the flexible tube body so as to be movable in the direction, for example, by preliminarily slackening each shape memory wire, the shape memory wire pair of the shape memory wire pair can be formed without bending the joint body. The length can be adjusted.

Further, the second connecting body is attached to the first connecting body so that the transformation temperature of the shape memory wire of the first connecting body and the shape memory wire of the second connecting body facing each other are different from each other. Since they are arranged as described above, it is possible to suppress the thermal influence between the shape-memory wire rods facing each other as much as possible.

[0012]

Embodiments of the present invention will be described below with reference to the drawings. 1 to 11 show an embodiment of the present invention. FIG. 2 shows a usage state of the industrial endoscope 1 inserted into the industrial pipe P such as a gas pipe. This industrial endoscope 1 has one illumination window 2 on the front end surface.
And two observation windows 3 are provided. Further, on the distal end surface of the industrial endoscope 1, there are three multi-degree-of-freedom manipulators (multi-joint flexible tubes) with a multi-joint structure that flexibly bends.
The base end portions of 4a, 4b and 4c are fixed. These manipulators 4a, 4b, 4c are used to perform various works in the industrial pipeline P.

The first manipulator 4a is provided with an illuminating device and an observing device 5 such as a CCD at its tip, and a working section for monitoring the repair section Q in the industrial pipeline P in close proximity and directly is enlarged. It is configured as an endoscopic system unit.

A micro gripper 6 is provided at the tip of the second manipulator 4b. The micro gripper 6 is configured as a tool transfer unit that holds a work tool 7 such as a welding material and brings the work tool 7 close to the repair unit Q.

The third manipulator 4c has a tip end portion for emitting a laser beam or the like and a grinding work portion 8 for a grinder or the like.
Is provided, and repair work such as welding with a laser beam or grinding using a grinder can be performed by approaching the repair portion Q in the industrial pipeline P.

The first to third manipulators 4a, 4b,
Since 4c has basically the same structure, the first manipulator 4a, which is one of them, will be described as an example with reference to FIG.

As shown in FIG. 1, the first manipulator 4a is composed of a flexible tube body 10 in which six joint bodies 11 (11a to 11f) are rotatably connected to each other in the longitudinal direction. . Each of the joint bodies 11a to 11f is composed of a cylindrical short tube, and the joint bodies adjacent to each other are joint fixing pins 1.
6 is rotatably connected. Further, each of the joint bodies 11a to 11f is provided with a total of six through holes as shown in FIG. These through-holes extend in the longitudinal direction of the joint body 11, and the through-holes 9 and 9'are provided symmetrically to each other with respect to the axial center of the joint body 11. In this configuration, the joint body 11f arranged at the base end of the flexible tube body 10 is fixed to the distal end surface of the industrial endoscope 1.

In the flexible tube body 10 formed by connecting the joint bodies 11a to 11f, the through holes 9 of the joint bodies 11a to 11f are formed.
Are arranged continuously in the longitudinal direction to form a first lumen (upper lumen in the drawing), and the through holes 9 ′ are arranged continuously in the longitudinal direction to form the second lumen. A lumen (lower lumen in the figure) is formed (of course, similarly, another lumen is formed by another through hole). A first connecting body 8a, which is formed by sequentially connecting the shape memory line pairs 19a, 19b, 19c, is inserted and arranged in the first lumen. Further, a second connecting body 8b formed by sequentially connecting the shape memory line pairs 19d, 19e, 19f is also inserted and arranged in the second lumen.

Each shape memory wire pair 19a to 19f has two shape memory wires 12 (12a) having the same length but different transformation temperatures.
.About.12f) and 13 (13a to 13f) are connected via a connecting member 15. That is,
Taking the shape memory wire pair 19a as an example, the shape memory wire pair 19a is composed of a low transformation point shape memory wire 12a having a low transformation point temperature and a high transformation point shape memory having the same length and a high transformation point temperature. The wire 13a is formed by being connected via a connecting member 15 that blocks heat transfer between them. The shape memory wire 12
(12a to 12f) and 13 (13a to 13f) are those whose length expands and contracts at the transformation point in Sakai. That is, it is a bidirectional one in which its length contracts when it is heated to a temperature higher than the transformation point, and it expands to its original length when the temperature is lowered from this state to a temperature lower than the transformation point.

In the first connecting body 8a, each shape memory line pair 19a, 19b, 19c is fixed to the fixing member 14 respectively.
It is configured by connecting via b and 14c. Further, in this state, each shape memory line pair 19a, 19
The heat transfer between the b and 19c is blocked by the fixing members 14b and 14c. In this case, each shape memory line pair 19
a, 19b, 19c are low transformation point shape memory wire 12 on the front side.
a, 12b, 12c are arranged, and the high transformation point shape memory wire rods 13a, 13b, 13c are arranged on the rear side and are connected to each other. That is, in this state, the first connecting body 8
The structure a is configured such that the low transformation point shape memory wire and the high transformation point shape memory wire are alternately repeated from the tip side.

Each shape memory line pair 19a, 19b, 1
The connecting means of 9c are shown in (b) and (c) of FIG. 1 (the same applies to 19d, 19e, 19f described later). The fixing member 14 (14b to 14c and 1 described later)
4f, 14g) are shown in the figure (shape memory line pair 19a, 1
9b is shown as an example of a comrades connection. ), The shape memory wire rods (13a, 12b) are connected by caulking and fixing by a caulking member 17 having a thin central portion, and the shape memory wire rods (13a, 12b) are arranged in the thin central portion of the caulking member 17. It is supported and fixed to the joint body 11 by the two support pins 18 formed. FIG. 1B is a view of the connecting portion viewed from the side, and FIG. 1C is a view of the connecting portion viewed from above.

The first connecting body 8a having the above structure is arranged in the first lumen in the following state. That is, the low transformation point shape memory wire 12 of the shape memory wire pair 19a
a is a first joint body 11a and a second joint adjacent to the first joint body 11a in a state where the tip thereof is fixed in the through hole 9 of the first joint body 11a located closest to the tip end using the fixing member 14a. It is arranged across the body 11b. In addition, the low transformation point shape memory wire 12a and the high transformation point shape memory wire 13a
The connecting member 15, which is a connecting portion with the, is arranged movably in the axial direction at a substantially central portion in the through hole 9 of the second joint body 11b. The high transformation point shape memory wire 13a is arranged so as to straddle between the second joint body 11b and the third joint body 11c, and the high transformation point shape memory wire rod 13a and the low transformation point shape memory wire rod 13a are arranged. A fixing member 14b which is a connecting portion with 12b (a connecting portion between the shape memory line pair 19a and the shape memory line pair 19b).
Is fixed to the substantially central portion of the through hole 9 of the third joint body 11c. Low transformation point shape memory wire rods 12b and 12c and high transformation point shape memory wire rods 13b and 13c on the rear side of this
Similarly to the arrangement configuration described above, the connection member 15 is arranged so as to be movable in the axial direction, the fixing member 14c is fixed to the joint body 11e, and the end of the high transformation point shape memory wire 13c located at the base end. The portion is fixed to the base end portion of the sixth joint body 11f. That is, each shape memory line pair 1
9a, 19b, and 19c are arranged so as to straddle the three joint bodies, and both ends thereof are fixed, and the central connecting member 15 is arranged so as to be movable in the axial direction. .

On the other hand, the second connecting body 8b inserted and arranged in the second lumen has the shape memory line pairs 19d and 19b.
e and 19f are connected to each other via fixing members 14f and 14g, respectively. Further, in this state, the heat transfer between the shape memory line pairs 19d, 19e, 19f is blocked by the fixing members 14f, 14g. Each shape memory wire pair 19d, 19e, 19f has low transformation point shape memory wire rods 12d, 12e, 12f arranged on the front side,
High transformation point shape memory wire rods 13d, 13e, 13f are arranged on the rear side and are connected to each other.

The second connecting body 8b thus constructed is also arranged in the second lumen in substantially the same manner as the first connecting body 8a. That is, the tip of the low transformation point shape memory wire 12d of the shape memory wire pair 19d is fixed to almost the tip of the through hole 9 of the first joint body 11a via the fixing member 14e, and is connected on the rear side thereof. The member 15 is movably arranged in the axial direction, the fixing members 14f and 14g are fixed to the joint bodies 11b and 11d, and the end portion of the high transformation point shape memory wire 13f located at the base end is connected to the sixth joint body 11f. It is fixed to almost the center of the.

However, in this case, the second connecting member 8
b is arranged so as to be displaced from the first connecting portion 1 toward the distal end side by one joint. That is, the second connecting body 8
b is the low transformation point shape memory wire 12 on the first connecting portion 1 side.
High transformation point shape memory wire rods 13d, 13e, 13f are arranged at positions facing a, 12b, 12c, and high transformation point shape memory wire rods 13a, 13b, 1 on the side of the first connecting portion 1 are formed.
Low transformation point shape memory wire 12e, 1 at a position facing 3c
2f is placed. Along with this, in the first connecting portion 1 and the second connecting body 8b, the positions where the fixing member 14 and the connecting member 15 are arranged are reversed.

Further, each shape memory wire rod 12 (12a to 12).
F) and 13 (13a to 13f) are preliminarily provided with slack as shown in FIG. Specifically, for each shape memory wire pair 19a to 19f, the shape memory wire (12 or 1
3) The slack is given by an amount corresponding to the maximum contraction amount for one piece.

Further, as shown in FIG. 3, signal lines 19 are connected to the fixing member 14 and the connecting member 15, and the signal lines 19 correspond to the joints A to E, respectively. It is connected to the control IC 21 ... Also,
A control line 20 is connected to each control IC 21, and the control line 20 controls a power supply to each shape memory wire rod 12, 13 (not shown) 22 (provided on the hand side).
It is connected to the. In addition, as shown in FIG.
The C21, the signal line 20, and the control line 21 are arranged inside a groove 29 provided in the axial direction of the joint body 11. In this case, the signal line 20 and the control line 21 are arranged near the axis of the joint fixing pin 16. That is, with such a configuration, the shape memory wire rods 12a to 12f and 13a to 13f can be selectively energized and heated.

Next, the operation of the manipulator 4a having the above structure will be described. In the manipulator 4b, a bending operation of each of the joint portions A to E is performed by a signal input to the control IC 21 by the control device 22 (not shown) on the hand side. Hereinafter, the bending operation of the manipulator 4b will be described with reference to FIGS. 6 to 10.

First, a case will be described in which only the first joint portion A located closest to the tip side is curved upward in the drawing. When the high transformation point shape memory wire 13a is heated and shrunk by the maximum shrinkage amount (assumed to be S) from the linear state (non-energized state) shown in FIG. 6, a low transformation point shape memory wire 12a and a high transformation point shape memory wire 13a are obtained. When the low transformation point shape memory wire 12a is heated and shrunk from this state, the amount of slack (= S) provided in advance disappears, as shown in FIG.
Each of the two joints A and B bends upward by an angle corresponding to a half length of the contracted amount of the low transformation point shape memory wire 12a. That is, the amount of slack is eliminated by contracting one shape memory alloy wire, and the two joints are bent by heat-contracting another shape memory alloy wire.

In order to return the second joint B to the linear shape from this state, it is necessary to heat the shape memory wire (12e or 13e) between the fixing members 14f to 14g to apply tension. Shape memory wire (12e or 13e)
When the shape memory wire (12e or 13e) is contracted, the shape memory wires (12e or 13e) are arranged so as to straddle the second joint portion B and the third joint portion C. Therefore, as shown in FIG. The force in the direction indicated by the arrow acts on the joint portion C of No. 3, and the third joint portion C is bent downward.
Further, in order to return the third joint C to the linear shape from this state, it is necessary to heat the shape memory wire (12b or 13b) between the fixing members 14b to 14c to apply tension. , In this case also, as shown in FIG.
A force in the direction indicated by the arrow acts on the joint D of the above, and the fourth joint D is bent upward. Further, from this state, in order to return the fourth joint portion D to the linear shape, the shape memory wire (12) between the fixing members 14g to 14h is used.
f or 13f) needs to be heated and tensioned, but for the same reason, the fifth joint E bends downward. Then, finally, by heating the shape memory wire (12c or 13c) between the fixing members 14c to 14d, the state as shown in FIG. 10 can be obtained as a whole.

That is, in order to bend only the first joint portion A in the upward direction, between the fixing members 14f to 14g, 14g to 1
It is necessary to set the slack of each shape memory wire between 4h, 14b to 14c, and 14c to 14d to zero, and further shrink the shape memory wire between the fixing members 14a to 14b to the original slack amount or more.

As a method of heat-shrinking the shape memory wire in this way, for example, the low transformation point shape memory wire 12b,
12c and 12f are heated to shrink by the maximum shrinkage amount, and further the high transformation point shape memory alloy 13a is heated to shrink by the maximum shrinkage amount. At this time, the high transformation shape memory wire rods 13e, 13f, 13b arranged to face the low transformation point shape memory wire rods 12b, 12c, 12f set the transformation point high (the reverse transformation end temperature of the low transformation point shape memory wire rod). Af
Point <high transformation shape memory wire rod reverse transformation start temperature As point), so low transformation point shape memory wire rods 12b, 12c, 12f
Does not shrink due to the effect of heat. Further, in this case, the heat generated when the high transformation point shape memory alloy 13a is heated and contracted is also transmitted to the low transformation point shape memory wire 12e,
The low transformation point shape memory wire 12e is shrunk by the maximum shrinkage amount.

That is, the shape memory wire rods 12b, 12c, 1
When 2f and 13a are heated, the fixing members 14a to 14b
, 14b to 14c, 14c to 14d, 14f to 1
The shape memory wire between 4g and 14g to 14h is in a state without slack, and the joints B, C, D, and E are not bent in either the upper or lower direction. Then, in this state, the shape memory wire 1
When 2a is heated and contracted, the first joint portion A bends upward. Also in this case, since the point shape memory wire 13d has a higher transformation point than the shape memory wire 12a,
The shape-memory wire rod 13 is affected by the heat of the shape-memory wire rod 12a.
d does not shrink.

In addition, the shape memory wire is heated and shrunk to
As another method of bending the joint part A of the above upward, the high transformation point shape memory wire rods 13a, 13b, 13c, 13e, 13f
It is also conceivable that the material is heated to shrink by half the maximum shrinkage. In this case, 13a, 13b, 13c, 1
The heat generated when the high transformation point shape memory wire rods 13a, 13b, 13e, 13f are heated is also transmitted to the low transformation point shape memory wire rods 12e, 12f, 12b, 12c facing the 3e, 13f, and these shrink. . The transformation point is set in advance so that the shrinkage amount of the low transformation point shape memory wire rods 12e, 12f, 12b, 12c at this time is half the total shrinkage amount. Thereby, the fixing members 14a to 1
4b, 14b-14c, 14c-14d, 14f
The shape memory wire rod between 14g and 14g is in a state where there is no slack, and the joint portions B, C, D, and E are not bent in either the upper or lower direction. Then, in this state, when the low transformation point shape memory wire 12a is heated and completely contracted, the joint portion A bends upward.

Further, as another method, the high transformation point shape memory wire rods 13a, 13b, 13c may be heated to shrink them by the maximum shrinkage amount. In this case, heat is also transmitted to the low transformation point shape memory wire rods 12e and 12f, which are located opposite to the high transformation point shape memory wire rods 13a, 13b and 13c, and these are completely shrunk. Thereby, the fixing members 14a to 1
4b, 14b-14c, 14c-14d, 14f
The shape-memory wire rods for 14 g to 14 g and 14 g to 14 h have no slack, and the joint portion A bends upward when the 12 a is heated and shrunk in this state.

Further, in order to bend the joint portion A downward, the shape memory wire rod 12d is heated and completely contracted to eliminate slack between the fixing members 14e to 14f, and the shape memory wire rod 13d is heated here. do it.

Based on the above concept, the other joints B to E
Similarly, it can be bent in both upper and lower directions. It is to be noted that FIG. 11 shows the energization places when the respective joints are bent in both up and down directions. In the figure, the underlined shape memory wire rods are heated so as to be contracted by half the maximum contraction amount, and the underlined shape memory wire shapes are shown. It is shown that the memory wire is heated so as to be contracted by its maximum contraction amount. In addition, the bending angle of the joint can be changed by adjusting the heating amount of the shape memory wire having the number marked with *.

As described above, the manipulator 4a of the present embodiment forms a shape memory wire pair by connecting two shape memory wire rods having different transformation point temperatures, and the two shape memory wire pairs having different transformation point temperatures are connected. Since the shape memory wire pair is arranged and fixed to the flexible tube body so that the connecting portion of the shape memory wire is movable in the longitudinal direction of the flexible tube body, each shape memory wire has a slack in advance as described above. By letting me know
The length of the shape memory line pair can be adjusted without bending the joint bodies 11a to 11f. Therefore, by the above-described operation, it is possible to bend only the necessary joints by a certain angle without bending the joints other than the desired portion. Further, since each shape memory wire is configured to be selectively heated, the bending angle of the joint can be adjusted freely. Further, the second connecting body 8b is replaced with the first connecting body 8a so that the transformation temperature of the shape memory wire of the first connecting body 8a and the shape memory wire of the second connecting body 8b facing each other are different. Since they are arranged opposite to each other, heat transfer between the opposing shape memory wire rods does not occur as long as the low transformation point shape memory wire rod is heated. Further, even in the case of heating the high transformation point shape memory wire, in the present embodiment, the heat transferred from the shape memory wires facing each other is utilized effectively for the bending operation of the joint portion, so to speak, the thermal influence from the shape memory wire. Since the flexible tube body has a small diameter, the desired joint can be bent surely and easily without applying an extra load.

12 and 13 show a first multi-joint flexible tube.
A modification of is shown. In this configuration, by devising the method of arranging the shape memory wire rods in the joint body 11 which is the same as that of the embodiment, the joint body is bent in two directions as in the embodiment. FIG. 12 shows the structure for one joint. The shape-memory wire rods 31 are provided so that they intersect each other at the central portion and the intersections thereof are tied so that the intersections are on the axis of the joint fixing pin 16.
Then, in this state, both ends of the shape memory wire 31 are fixedly supported by the joint body 11. Further, an elastic body 32 is provided at the joint portion of the joint body 11. The elastic body 32 normally keeps the joint portion straight when no force is applied. The shape memory wire 31 is also provided on the opposite side in FIG. A current-carrying wire (not shown) is arranged at the end of the shape-memory wire rod 31.

Next, the operation of the above configuration will be described with reference to FIG. When the joint portion is bent upward, when the shape memory wire 31 of nn ′ in FIG. 13A is energized to be heated and contracted, the shape memory alloy nn ′ exerts a force as illustrated. f is generated, and the resultant force f ′ causes the shape memory wire 31
The knot 0 receives an upward force in the figure and moves upward as indicated by the dotted line (indicated by 0'in the figure). at the same time,
Since the shape memory wire nn ′ is contracted, the joint portion is bent upward as shown in FIG.

Further, when the joint portion is bent, n-n 'and m
Since the shape memory wire member 31 of −m ′ is in close proximity, the heat generation of n−n ′ is also transmitted to m−m ′, so that m−m ′ also contracts. In other words, the joint portion is bent by the combined force of the contraction force of n-n 'and the contraction force of m-m',
Its ability is quite large.

Further, as shown in FIG. 13C, when the slack of the shape memory wire rod 31 when the knot 0 of the shape memory wire rod 31 is moved to 0 ', the length of n-0 and n in the figure are measured. -0
Comparing the lengths of ', the length of n-0' is shorter by x. That is, only this x is contracted and bent. When the length of m-0 and the length of m-0 'are compared, the length of m-0' is shorter by x'without much difference. That is, m-0-m 'causes a slight slack when it becomes m-0'-m', and n-0-n 'becomes n-0'-n.
Since there is a possibility that it will be able to contract as much as the contraction amount when it became ‘′, the joint part bent by the contraction force of n−n ′ will be greatly curved by this further contraction of m−0′−m ′. It is possible to do that, in the figure, a is a point n
Is a circle passing through the zero point centered at, and b is a circle passing through the zero point centered at the point m.

Therefore, with this construction, even if the flexible tube is made thin, one joint can be bent reliably and easily in two directions, and the bending angle can be made large accordingly.

In this structure, as shown in FIG. 14, if the knot of the shape memory wire 31 is fixed by the pipe member 33 made of a magnet, and the joint fixing pin 16 is also made of a magnet, the magnetic force of the magnets will be generated. The pipe member 33 can be positioned with respect to the joint fixing pin 16. That is, the pipe member 33 at the intersection of the shape memory wire 31 can be held at the position of the joint fixing pin 16. Therefore, it is possible to prevent the displacement of the intersecting portion of the shape memory wire rod 31 and ensure a reliable operation. Further, as a method of holding the pipe member 33 at the intersection of the shape memory wire 31 at the position of the joint fixing pin 16, there is also a method of supporting the pipe member 33 on four sides by elastic bodies 34 as shown in FIG. .

The second part of the multi-joint flexible tube is shown in FIGS.
A modification of is shown. As shown in FIG. 16, the joint fixing pin 1
A pair of shape memory wire rods 36 are provided in the longitudinal direction passing on the axis of 6, and both ends thereof are fixed to the joint body 11. A pipe member 38 is provided near the joint fixing pin 16 outside the shape memory wire 36, and shape memory springs 37 that contract when heated are provided above and below the pipe member 38, respectively. The shape memory springs 37 are connected to energizing wires connected to the control IC 21, respectively.

In this configuration, in order to bend the joint portion upward, first, as shown in FIG. 17A, the upper side of the shape memory spring 37 is heated to move the pipe member 38 to the upper side in the figure. Let When the shape memory wire rod 36 is heated and shrunk in this state, the joint portion bends upward as shown in FIG. Further, when the joint portion is bent downward, the lower side of the shape memory spring 37 may be heated to heat the shape memory wire rod 36.

18 and 19 show a third example of the articulated flexible tube.
A modification of is shown. Similar to the second modified example, the shape memory wire 36 is provided in the central portion of the joint body 11, and further, as shown in (a) of FIG. 18, at the positions above and below the joint portion of the joint body 11. The electromagnet 51 and the permanent magnet 52 are provided so as to face each other.

With this structure, in order to bend the joint portion upward, in FIG. 18 (a), an attractive force is generated between the upper electromagnet 51 and the permanent magnet 52, and the lower electromagnet 51 and the permanent magnet 52 are made permanent. The electromagnets 51 are controlled so that a repulsive force is generated between the magnets 52. Then, the joint portion bends slightly upward, and accordingly, the shape memory wire 36 shifts upward. In this state, if the shape memory wire 36 is heated and shrunk, the joint portion bends sufficiently upward as shown in FIG.
In order to bend the joint portion downward, the attraction / repulsion relationship between the electromagnet 51 and the permanent magnet 52 on the upper side and the lower side may be reversed from the above-described state.

[0049]

As described above, the multi-joint flexible tube of the present invention forms a shape memory wire pair by connecting two shape memory wire rods having different transformation point temperatures, and has different transformation point temperatures. Since the shape memory wire pair is arranged and fixed to the flexible tube body so that the connecting portion of the two shape memory wire rods can be moved in the longitudinal direction of the flexible tube body, for example, each shape memory wire rod is loosened in advance. By holding it, the length of the shape memory line pair can be adjusted without bending the joint body. Therefore, it is possible to bend only the necessary joints by a certain angle without bending the joints other than the desired portion.

Further, since each shape memory wire can be selectively heated, the bending angle of the joint can be adjusted freely. Further, the second connecting body is formed into the first connecting body so that the shape memory wire of the first connecting body and the shape memory wire of the second connecting body facing each other have different transformation point temperatures.
The heat transfer between the opposing shape memory wire rods does not occur as long as the low transformation point shape memory wire rod is heated. Further, even when the high transformation point shape memory wire is heated, if the heat transmitted between the opposing shape memory wires is properly used for the bending operation of the joint, even if the flexible tube body has a small diameter. The desired joint can be bent securely and easily without applying an extra load.

[Brief description of drawings]

1A is a side sectional view of a flexible tube body of a manipulator according to an embodiment of the present invention, FIG. 1B is an enlarged side sectional view of a fixing member in FIG. 1A, and FIG. 2) is a cross-sectional view when viewed from above.

FIG. 2 is a state diagram showing a state in which the endoscope apparatus including the manipulator of FIG. 1 is inserted and arranged in a pipe.

FIG. 3 is a schematic cross-sectional view showing a heating means for the shape memory wire arranged in the flexible tube body of the manipulator of FIG.

FIG. 4 is a front view of a joint body that constitutes the flexible tube body of the manipulator of FIG.

FIG. 5 is a perspective view schematically showing wiring in the vicinity of a joint portion.

FIG. 6 is a schematic view showing a linear state of a flexible tube body.

FIG. 7 is a schematic view showing a first bending state of the flexible tube body.

FIG. 8 is a schematic view showing a second bent state of the flexible tube body.

FIG. 9 is a schematic view showing a third bending state of the flexible tube body.

FIG. 10 is a schematic view showing a state in which only the first joint portion of the flexible tube body is bent.

FIG. 11 is a diagram showing an energization place when each joint portion is bent in the vertical direction.

FIG. 12 is a perspective view of an articulated flexible tube according to a first modification.

FIG. 13 is an explanatory view showing the operation of the articulated flexible tube of FIG.

FIG. 14 is an enlarged cross-sectional view showing a modified example of the intersecting portion of the shape memory wire rod arranged in the articulated flexible tube of FIG.

15 is a perspective view showing another modified example of the intersecting portion of the shape memory wire arranged in the multi-joint flexible tube of FIG.

16A is a schematic view of an articulated flexible tube according to a second modification, and FIG. 16B is a sectional view taken along line AA of FIG. 16A.

17 is a diagram showing an operating state of the articulated flexible tube of FIG.

18A is a schematic view of an articulated flexible tube according to a third modification, and FIG. 18B is a sectional view taken along line BB of FIG.

FIG. 19 is a diagram showing an operating state of the articulated flexible tube of FIG. 18.

20A is a cross-sectional view showing an example of one joint of a conventional multi-joint flexible tube, and FIG. 20B is a cross-sectional view taken along line CC of FIG. 20A.

[Explanation of symbols]

8a ... 1st connection body, 8b ... 2nd connection body, 10 ... Flexible tube main body, 11 ... Joint body, 12, 13 ... Shape memory wire, 1
4 ... Fixing member, 15 ... Connecting member, 19a, 19b ... Shape memory line pair.

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[Procedure amendment]

[Submission date] May 26, 1994

[Procedure Amendment 1]

[Document name to be amended] Statement

[Correction target item name] 0008

[Correction method] Change

[Correction content]

In such a state, the joint cannot be bent as desired, and an extra load is applied to the rotary shaft 64 .

[Procedure Amendment 2]

[Document name to be amended] Statement

[Correction target item name] 0017

[Correction method] Change

[Correction content]

As shown in FIG. 1, the first manipulator 4a is composed of a flexible tube body 10 in which six joint bodies 11 (11a to 11f) are rotatably connected to each other in the longitudinal direction. . Each of the joint bodies 11a to 11f is composed of a cylindrical short tube, and the joint bodies adjacent to each other are joint fixing pins 1.
6 is rotatably connected. Further, a total of seven through holes are provided in each of the joint bodies 11a to 11f as shown in FIG. These through-holes extend in the longitudinal direction of the joint body 11, and the through-holes 9 and 9'are provided symmetrically to each other with respect to the axial center of the joint body 11. In this configuration, the joint body 11f arranged at the base end of the flexible tube body 10 is fixed to the distal end surface of the industrial endoscope 1.

[Procedure 3]

[Document name to be amended] Statement

[Name of item to be corrected] 0025

[Correction method] Change

[Correction content]

However, in this case, the second connecting member 8
b is arranged in a state of being displaced by one joint toward the tip side with respect to the first connecting body 8a . That is, the second connecting body 8b is the low transformation point shape memory wire 1 on the first connecting body 8a side.
High transformation point shape memory wire rods 13d, 13e, 13f are arranged at positions facing 2a, 12b, 12c .
High transformation point shape memory wire 13a, 13 on the side of the connecting body 8a of
low transformation point shape memory wire 12 at a position facing b and 13c
e and 12f are arranged. Along with this, the arrangement positions of the fixing member 14 and the connecting member 15 are reversed in the first connecting body 8a and the second connecting body 8b.

[Procedure amendment 4]

[Document name to be amended] Statement

[Name of item to be corrected] 0027

[Correction method] Change

[Correction content]

Further, as shown in FIG. 3, signal lines 19 are connected to the fixing member 14 and the connecting member 15, and the signal lines 19 correspond to the joints A to E, respectively. It is connected to the control IC 21 ... Also,
A control line 20 is connected to each control IC 21, and the control line 20 controls a power supply to each shape memory wire rod 12, 13 (not shown) 22 (provided on the hand side).
It is connected to the. In addition, as shown in FIG.
The C21, the signal line 19, and the control line 20 are arranged inside a groove 29 provided in the axial direction of the joint body 11. In this case, the signal line 19 and the control line 20 are arranged near the axis of the joint fixing pin 16. That is, with such a configuration, the shape memory wire rods 12a to 12f and 13a to 13f can be selectively energized and heated.

[Procedure Amendment 5]

[Document name to be amended] Statement

[Correction target item name] 0028

[Correction method] Change

[Correction content]

Next, the operation of the manipulator 4a having the above structure will be described. In the manipulator 4a , a bending operation of each of the joint portions A to E is performed by inputting a signal to the control IC 21 by the control device 22 (not shown) on the hand side. Hereinafter, the bending operation of the manipulator 4a will be described with reference to FIGS. 6 to 10.

[Procedure correction 6]

[Document name to be amended] Statement

[Name of item to be corrected] 0037

[Correction method] Change

[Correction content]

Based on the above concept, the other joints B to E
Similarly, it can be bent in both upper and lower directions. In addition, the figure shows the energizing place when bending each joint in both up and down directions .
Eleven . In the figure, the underlined shape memory wire rods are heated so as to be contracted by half the maximum contraction amount, and the underlined shape memory wire shapes are shown. It is shown that the memory wire is heated so as to be contracted by its maximum contraction amount. In addition, the bending angle of the joint can be changed by adjusting the heating amount of the shape memory wire having the number marked with *.

[Procedure Amendment 7]

[Document name to be amended] Statement

[Correction target item name] 0041

[Correction method] Change

[Correction content]

Further, at this time, the shapes of n-n 'and m-m'
When the joint body 11 has a small diameter,
Therefore, the heat generated in n-n 'is transmitted to m-m', and m-
m'will also contract. In other words, the joint portion is bent by the combined force of the contraction force of n-n 'and the contraction force of m-m', and the amount of force is considerably large.

[Procedure Amendment 8]

[Document name to be corrected] Drawing

[Name of item to be corrected] Fig. 10

[Correction method] Change

[Correction content]

[Figure 10]

Claims (1)

[Claims] 1. A shape-memory wire rod that expands and contracts according to temperature changes is provided in a flexible tube body that is formed by connecting a plurality of joint bodies so as to be rotatable relative to each other in the longitudinal direction, and the shape-memory wire rod is expanded and contracted. In a multi-joint flexible tube in which each joint body is rotated to bend the flexible tube main body, two shape memory wire rods having different transformation points are connected to each other, and both ends thereof are connected to the joint body. Fixed and above 2
A first connecting body formed by connecting a plurality of shape memory line pairs, each of which has a shape memory wire connecting portion movable in the longitudinal direction of the flexible tube body, in the longitudinal direction of the flexible tube body; A second connecting body formed by connecting the shape memory wire pair in the longitudinal direction of the flexible tube main body at a position facing the first connecting body; and a heating means for selectively heating each shape memory wire. And the second connecting body is arranged with respect to the first connecting body such that the transformation temperature of the shape memory wire of the first connecting body and the shape memory wire of the second connecting body facing each other are different. A multi-joint flexible tube characterized by.