JP2001252736A - Manufacturing method for shape memory alloy coil - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a manufacturing method of a shape memory alloy coil capable of efficiently manufacturing the shape memory alloy coil of high quality. SOLUTION: While letting out a core wire continuously in its axial direction, a wire stock 2 of the shape memory alloy coil is wound around the core wire 1, the shape memory alloy coil is manufactured by coiling the wire stock 2.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method of manufacturing a shape memory alloy coil.

[0002]

2. Description of the Related Art In recent years, shape memory alloy coils have been used as actuators for endoscopes, catheters, guide wires, and the like for insertion into blood vessels, internal organs, and the like for examination and surgery of the body. It is widely used because of low dust generation. The shape memory alloy coil is Ni-
It is manufactured by forming a wire such as a Ti alloy or a Cu—Zn—Al alloy into a coil shape and performing a shape memory process on the wire.

FIG. 5 is a schematic view showing a method of manufacturing a conventional shape memory alloy coil. In FIG. 5, reference numeral 1 denotes a core wire. As the core wire 1, a wire having high strength such as a stainless steel wire is usually used. Both ends of the core wire 1 are fixed to rolls 20 and 21, respectively.
Reference numeral 21 is configured to rotate in synchronization. Accordingly, if one end of the wire 2 of the shape memory alloy coil is fixed to the core wire 1 and the rolls 20 and 21 are rotated and the wire 2 is moved in the axial direction of the core wire 1 while being sent out in the axial direction,
The strand 2 is formed in a coil shape. Next, a shape memory process is performed on the wire 2 and the core wire 1 is pulled out to obtain a shape memory coil.

[0004]

The core wire used in the above-mentioned manufacturing method is usually about 20 cm. This is because if the core wire becomes longer, twisting occurs during coiling and the quality of the shape memory alloy coil deteriorates, and the distance between the rolls 20 and 21 becomes longer and the device becomes larger. is there.

However, the maximum length of a shape memory alloy coil that can be manufactured with a core wire of about 20 cm is about 8 cm.
For this reason, for example, if a large number of coils of about 8 cm are to be manufactured, the work of exchanging the core wires and the work of fixing the ends of the strands to the core wires at the start and end of winding are performed by the number of coils to be manufactured. It must be performed frequently, and it is not possible to improve production efficiency. The coil length is 8
When a coil of cm or more is required, it is necessary to connect a plurality of coils by bonding, welding, or the like.

An object of the present invention is to solve the above-mentioned problems and to provide a method of manufacturing a shape memory alloy coil capable of efficiently producing a long or large volume of shape memory alloy coil.

[0007]

A method of manufacturing a shape memory alloy coil according to the present invention has the following features. (1) At least a step of forming a coil into a coil shape while continuously feeding the core wire in the axial direction, winding the wire of the shape memory alloy coil around the core wire and winding the wire around the core wire. A method for manufacturing a shape memory alloy coil, characterized by comprising:

(2) The method for manufacturing a shape memory alloy coil according to (1), wherein a wire material different from the wire is wound around the core wire before the wire is wound, and the wire is wound from above the wire.

(3) The method for manufacturing a shape memory alloy coil according to (2), wherein the another wire is a flat wire.

(4) The method for manufacturing a shape memory alloy coil according to (3), wherein the rectangular wire has a thickness that continuously changes in the axial direction.

(5) The method for manufacturing a shape memory alloy coil according to the above (1), further comprising a step of heating the wire wound around the core wire to perform a shape memory process.

(6) The method for manufacturing a shape memory alloy coil according to the above (1), further comprising a step of attaching a plurality of pipe members at intervals outside the strand wound around the core wire.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in detail with reference to the drawings. FIG. 1 is a diagram showing an example of a method for manufacturing a shape memory alloy coil of the present invention. FIG. 1 also shows a manufacturing apparatus for implementing the method for manufacturing a shape memory alloy coil of the present invention. FIG. 2 is an enlarged view showing a region R surrounded by a dotted line in FIG.

As shown in the examples of FIGS. 1 and 2, the method of manufacturing a shape memory alloy coil according to the present invention provides a method of manufacturing a shape memory alloy coil around a core wire 1 while continuously feeding the core wire 1 in its axial direction. At least a step of winding the wire 2 around the core wire 1 and forming the element wire 2 into a coil shape is provided. This step includes a sending bobbin 3 for sending out the core wire 1, a winding bobbin 4 for winding up the sent core wire 1,
This is performed by a manufacturing apparatus having at least a wire sending bobbin 5 for sending out the wire 2 and a winding means 6. The winding means 6 is provided around the core wire 1 so that the wire 2 sent from the wire sending bobbin 5 is wound around the core wire 1 sent from the sending bobbin 3 to form a coil. It has the function of circling the bobbin.

In the example of FIG. 1, after completion of the above steps, the core wire 1
The shape memory processing and the attachment of the terminals are performed on the element wire 2 wound around as described later. Further, finally, the core wire 1 is extracted, cut into a predetermined length, and the like, and a product of the shape memory alloy coil is obtained. Reference numeral 13 denotes a capstan for applying a certain tension to the core wire 1 and is composed of two non-rotating rolls. The core wire 1 is wound between the rolls, and tension is applied to the core wire 1 by friction between the rolls and the core wire 1. In addition,
In addition, using a device that presses a friction plate (brake shoe) against the delivery bobbin 3 to add resistance to the rotation, the core wire 1 is used.
Can also be given tension.

As described above, in the production method of the present invention,
The core wire 1 is fed in the axial direction, and instead of rotating the core wire 1, the element wire 2 is rotated to form a coil. Therefore, unlike the related art, the core wire 1 can be provided in a wound state, so that a long core wire can be used without increasing the size of the device. In addition, the twist generated in the core wire can be suppressed.
Further, it is not necessary to frequently replace the core wire or fix the end of the element wire to the core wire.

In the present invention, a metal wire such as stainless steel, tungsten, molybdenum, and shape memory alloy is used as the core wire. The core wire is, for example, as shown in FIG.
Since it can be sent out from the state wound on the bobbin,
The length of the core wire is not particularly limited as in the prior art.

In the present invention, the method of sending out the core wire is not particularly limited, but as shown in the example of FIG.
The use of two bobbins arranged at an interval is a preferable mode in that a long core wire and a shape memory alloy coil can be easily handled. The distance between the bobbins is 1 m to 3 m, preferably 1.5 m to
It is better to set it to 2.5 m. The feed speed of the core wire depends on the size (soaking length) of the electric furnace 9 for performing a shape memory process described later in the example of FIG. For example, the soaking length is 1200 mm (the diameter of the heated portion is 30 m
m), the shape memory processing generally requires about 30 minutes to 1 hour, so the core wire sending speed is 1.2 m / h to 2.4 m / h, preferably 1.5 m / h.
/ Hour to 1.8 m / hour is good.

In the present invention, a wire made of a shape memory alloy, for example, Ti
-Ni binary alloy, Ti-Ni-Cu alloy, Ti-Ni-
A wire made of a Ti-Ni-based alloy such as Cu alloy, Ti-Ni-Nb alloy, Ti-Ni-Fe alloy, Cu
-Cu such as Zn-Al alloy, Cu-Al-Ni alloy
Wire made of a series alloy. In the present invention, the wire diameter of the element wire is not particularly limited, and may be appropriately selected according to the return force required for the shape memory alloy coil. The method of sending out the strands of the shape memory alloy coil is also
Although it is not particularly limited, it is a preferable embodiment to send out from a state wound around a bobbin similarly to the core wire.

In the present invention, the winding of the wire around the core wire may be performed by winding the wire as shown in FIG.
There is no particular limitation as long as the process is performed without rotating the core wire as in the related art. For example, in the manufacturing apparatus shown in FIG. 1, the wire 2 is wound around the core wire 1 by rotating the wire bobbin 5 around, but the present invention is not limited to this mode. Also in the present invention, it is necessary to fix the element wire to the core wire at the beginning and end of winding as in the conventional case. This fixing can be performed in the same manner as in the prior art.

In the example of FIGS. 1 and 2, before winding the wire 2, the wire 2 and another wire 7 are wound around the core wire 1, and the wire 2 is wound from above the wire 7. A flat wire is used as the wire 7. The manufacturing apparatus shown in FIGS.
A flat wire sending bobbin 8 for sending the flat wire 7 is also provided. The winding means 6 includes a flat wire sending bobbin 8
Also makes a revolving motion together with the wire sending bobbin 5. The orbital movement is such that the flat wire 7 sent out from the flat wire sending bobbin 8 winds around the core wire 1 before the wire 2 and the wire 2
Is wound around the core wire 1 from above the flat wire 7.

FIG. 3 is a view showing a flat wire 7 used in the examples of FIGS. 1 and 2, FIG. 3 (a) shows the upper surface, and FIGS. Line AA, Line BB, Line C
The cross section at -C is shown. As shown in the example of FIG. 3, the flat wire 7 has a thickness (t1, t2, t) in the axial direction.
3) changes continuously (t1 <t2 <t
3). In addition, the thickness of the flat wire referred to in the present invention means a length in a normal direction of the core wire when the flat wire is wound around the core wire. Therefore, if the wire 2 is wound from above the flat wire 7 and the manufacturing method of the present invention is performed, the outer diameter (coil outer diameter) of the wound wire 2 can be continuously changed. That is, by winding the rectangular wire 7, it is possible to obtain a plurality of types of shape memory alloy coils having different outer diameters.

The rectangular wire 7 shown in the example of FIG. 3 can be obtained by rolling a wire having a circular cross section with a roll. The thickness can be changed by changing the pressure of the roll during rolling. In addition, as long as the thickness is not changed, the flat wire 7 may be formed by extrusion using a die.

In the example of FIG. 1, a step of heating the wire 2 wound around the core wire 1 to perform a shape memory process is performed.
Reference numeral 9 denotes an electric furnace for performing a shape memory process. The heated part of the electric furnace 9 is a columnar space. As described above, in the manufacturing method of the present invention, since the shape of the strand 2 can be continuously processed, the production efficiency can be increased. Further, since the shape memory processing is performed before winding by the winding bobbin 4, even if the pitch of the shape memory coil is disturbed due to winding, simply heating and then performing a return processing can be easily performed. You can return to the original pitch. The heating temperature and the heating time in this shape memory processing may be set to the same values as in the related art.

Further, in the example shown in FIG. 1, a plurality of pipe members 10 are attached to the outside of the wire 2 wound around the core wire 1 at intervals. This pipe member 10 serves as an attachment margin for the shape memory alloy coil. FIG. 4 is a view showing a process of attaching the pipe member 10, which is shown in order. 1 is a cross-sectional view taken along line XX in FIG.

As shown in the example of FIG. 4A, the pipe members 10 are arranged on both sides of the core wire 1 in a state of being divided into two. 10a and 10b indicate half pipes. 11
Indicates a vacuum chuck manipulator holding half pipes (10a, 10b). When the core wire 1 and the strand 2 are sent to the position where the pipe member 10 is to be attached, the vacuum chuck manipulator 11 moves as shown in FIG. 4B, and the half pipes 10a and 10b
And are superimposed. Further, as shown in FIG.
These joints are irradiated with laser light 12. By the irradiation of the laser beam 12, the joint portion is fused to form the pipe member 10. Further, since local melting deformation occurs in the half pipes (10a, 10b), the pipe member 10 is not shown in FIG.
As shown in the figure, the wire 2 is fitted and firmly fixed.

[0027]

EXAMPLES The present invention will be specifically described below with reference to examples. Actually, according to the manufacturing method of the present invention shown in FIGS.
A shape memory alloy coil was manufactured.

As the core wire 1, a stainless wire having a wire diameter of 0.2 mm and a length of 1000 m was used. The core wire 1 was wound around a delivery bobbin 3 and set in the manufacturing apparatus shown in FIG. The delivery bobbin 3 and the take-up bobbin 4 are each formed by sandwiching one cylindrical member (length: 90 mm, outer diameter: 50 mm) between two disks (diameter: 100 mm, thickness: 10 mm). Using.

As the strand 2 of the shape memory alloy coil, a Ti-Ni alloy (50.2 at%) wire having a wire diameter of 0.1 mm and a length of 1000 m was used. The wire 2 was wound around a wire delivery bobbin 5 and set on a winding means 6. A single cylindrical member (length: 60 m) is also used as the wire delivery bobbin 5.
m, outer diameter: 30 mm) into two disks (diameter: 60 mm,
(Thickness: 5 mm).

The rectangular wire 7 has a thickness of 10 μm to 50 μm.
μm, a width of 100 μm to 500 μm, soft stainless steel (SUS304), and a length of 100 m were used. The flat wire 7 was also wound around the flat wire sending bobbin 8 and set on the winding means 6. The flat wire sending bobbin 8 is similar to the element wire sending bobbin 5.

Next, the tip of the flat wire 7 and the tip of the wire 2 are welded to the core wire 1 and the feed speed of the core wire 1 is 1.62 m /.
At this time, the number of revolutions of the winding means 6 was set to 270 rpm to manufacture a shape memory alloy coil. The electric furnace 9 used had a soaking length of 1200 mm (the diameter of the portion to be heated was 30 mm), and the heating temperature was set to 350 ° C. The production was performed continuously for 7 hours. As a result, a shape memory alloy coil having a coil length of 11.34 m could be manufactured. This is 8c
When cut to length m, 141 coils could be obtained.

Comparative Example A shape memory alloy coil was manufactured according to the conventional manufacturing method shown in FIG. As the core wire, a stainless steel wire similar to that of the above-described embodiment cut into a length of 20 cm was used. As the strand, the same shape memory alloy wire as in the above embodiment was used. When production was performed for 7 hours continuously in the same manner as in the example, only 24 coils of 8 cm (total coil length: about 1.9 m) could be produced.

[0033]

As described above, according to the manufacturing method of the present invention, a shape memory alloy coil can be manufactured using a long core wire, so that troublesome work does not need to be performed frequently and the production efficiency can be reduced. Improvement can be achieved. In addition, despite the fact that the core wire is long, it is possible to prevent the core wire from being twisted and the manufacturing apparatus from being enlarged.

[Brief description of the drawings]

FIG. 1 is a diagram showing an example of a method for manufacturing a shape memory alloy coil of the present invention.

FIG. 2 is an enlarged view showing a region R surrounded by a dotted line in FIG. 1;

FIG. 3 is a view showing a flat wire 7 used in the examples of FIGS.

FIG. 4 is a view showing a process of attaching the pipe member 10;

FIG. 5 is a diagram illustrating a method of manufacturing a conventional shape memory alloy coil.

[Explanation of symbols]

 1 core wire 2 strand of shape memory alloy coil

Claims (6)

[Claims] At least a step of winding a core wire of a shape memory alloy coil around the core wire and winding the core wire around the core wire while continuously feeding the core wire in the axial direction thereof, and forming the wire into a coil shape is provided. A method for manufacturing a shape memory alloy coil, comprising: 2. The method of manufacturing a shape memory alloy coil according to claim 1, wherein a wire material different from the wire is wound around the core wire before the wire is wound, and the wire is wound over the wire. 3. The method for manufacturing a shape memory alloy coil according to claim 2, wherein said another wire is a rectangular wire. 4. The method of manufacturing a shape memory alloy coil according to claim 3, wherein the rectangular wire has a continuously changing thickness in the axial direction. 5. The method for manufacturing a shape memory alloy coil according to claim 1, further comprising a step of heating the wire wound around the core wire to perform a shape memory treatment. 6. The method for manufacturing a shape memory alloy coil according to claim 1, further comprising a step of attaching a plurality of pipe members at an interval outside the strand wound around the core wire.