JP2018057512A - Operation wire and manufacturing method of the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an operation wire capable of obtaining sufficient bond strength with the counterpart member even when the wire is thin.SOLUTION: An operation wire 10 comprises a wire body 11 and a locking part 12 formed on a lateral face of one end of the wire body and composed of a plating layer 13. It is desirable that the wire body is a twisted wire, and it is also desirable that the locking part is generally cylindrical.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a wire for operating a posture or the like of a member away from a hand, and particularly relates to an ultrafine operation wire used for operation of a medical device or the like.

  In various medical devices inserted into the body, an operation wire is used to operate the distal end portion of the device from outside the body. The contents of the operation include an operation of bending an endoscope and a catheter, a rotation / opening / closing operation of a treatment tool such as a forceps, and an operation of a treatment tool attached to a medical robot. The distal end of the operation wire is joined to a curved portion or a treatment tool near the catheter tip, and the proximal end is joined to the operation portion. Accordingly, the bending portion and the treatment instrument in the body can be operated by moving the wire forward and backward with the operation portion at hand.

  As a method of joining the distal end of the operation wire to a counterpart member such as a treatment instrument, there are a method of fixing by brazing or welding, a method of caulking a pipe or the like to the tip of the wire and locking it to a recess or the like of the counterpart member, etc. Conventionally known. For example, Patent Document 1 describes an endoscope in which a wire receiver is formed on the most advanced bending piece of a bending portion, and a wire tip is brazed and fixed to the wire receiver in a vacuum environment or an inert gas environment. Yes. In Patent Document 2, a stop member is caulked and fixed to the tip of the operation wire, the operation wire is passed through a throttle hole provided in the most advanced node ring of the curved portion, and the operation wire is locked to the node ring by the stop member. An endoscope is described. In Patent Document 3, the distal end of the bending operation wire is inserted into a tubular fixing member, the fixing member is crimped and fixed to the bending operation wire by crimping, and the fixing member is brazed onto the inner surface of the joint piece distal end of the bending portion. The endoscope fixed by is described.

JP 2001-149307 A JP 2000-225121 A Japanese Patent Laid-Open No. 10-258025

  However, the conventional operation wire bonding method has a problem when it is desired to use a thinner wire and realize a smaller bonding structure.

  The joining of wires by brazing has a problem that the wire is corroded by the residual flux, or the strength of the wire is lowered by heating the vicinity of the brazing portion more than necessary. As the wire becomes thinner, it tends to break when there is corrosion, and the temperature tends to rise excessively because the heat capacity is small. In addition, when crimping a tubular member or the like on the wire, if the wire is too thin, sufficient crimping strength could not be obtained.

  The present invention has been made in consideration of the above, and an object of the present invention is to provide an operation wire capable of obtaining sufficient bonding strength with a counterpart member even when the wire is thin.

  In response to the above problem, the operation wire of the present invention has a wire body and a locking portion formed on a side surface of one end of the wire body and made of a plating layer.

  Preferably, the wire body is a stranded wire.

  Preferably, the locking portion has a substantially cylindrical shape. Moreover, Preferably, the length of the said latching | locking part is 8 mm or less. Preferably, the diameter of the wire main body is 1 mm or less, and the thickness of the locking portion is 0.01 mm or more and 0.1 mm or less. Preferably, the plating layer contains nickel.

  Preferably, the operation wire is used by being incorporated in a medical device.

  The operating wire manufacturing method of the present invention includes a step of preparing a wire body, a step of forming a first mask layer on a side surface near the tip of the wire body, and a second side of the wire body on both sides of the first mask. A step of forming a mask layer, a step of removing the first mask layer, a step of forming a plating layer in a portion where the first mask layer is removed, a step of removing the second mask layer, Cutting the wire body and the tip side of the plating layer to form a locking portion of a predetermined length.

  According to the operating wire or the manufacturing method of the operating wire of the present invention, since the wire main body and the engaging portion made of the plating layer are firmly integrated, even if the wire is thin, the wire main body and the engaging portion are Sufficient bonding strength can be obtained. Thereby, even if strong tension is applied to the operation wire, the joint structure with the counterpart member is hardly broken. Further, heat is not applied to the wire at the time of forming the locking portion, the range of selection of the wire material is expanded, and the durability is improved.

It is sectional drawing of the operation wire of one Embodiment of this invention. It is a partial expanded sectional view of the operation wire of one embodiment of the present invention. It is a figure which shows the manufacturing method of the operation wire of one Embodiment of this invention. It is a figure which shows the usage method of the operation wire of one Embodiment of this invention.

  As one embodiment of the operation wire of the present invention, an operation wire used for a bending operation of a catheter or the like will be described.

  In FIG. 1, the operation wire 10 of this embodiment includes a wire body 11 and a locking portion 12. The locking portion 12 is formed on the side surface of one end of the wire body and includes a plating layer 13.

  As the material of the wire body 11, a material having required characteristics can be used depending on the application. In an operation wire for a medical device, preferably an austenitic stainless steel wire, more preferably an austenitic stainless steel wire whose tensile strength is increased by work hardening is used. This is because even a small diameter has high tensile strength and excellent corrosion resistance. Examples of such a steel wire include SUS304WPB defined in JISG4314 and a stainless steel wire with a smaller diameter manufactured by the same method as SUS304WPB. In the operation wire of the present embodiment, the locking portion is made of a plating layer, and no heat is applied to the wire body when the locking portion is formed. For this reason, even when an austenitic stainless steel wire whose tensile strength is increased by work hardening is used, internal strain due to work hardening is not annealed when the locking portion is formed, and the tensile strength of the wire body does not decrease.

  The wire body 11 has a substantially circular cross section. The wire body 11 is preferably a stranded wire in which finer strands are twisted together. This is because, in addition to the flexibility of the wire body, the shear strength of the joint between the wire body and the plating layer is increased due to the surface irregularities. The structure of the stranded wire is not particularly limited. The strand may be a strand in which strands are twisted, or may be a strand in which strands are further twisted.

  The length of the wire body 11 is determined by the application and is typically 50 to 150 cm. The diameter D of the wire body 11 is preferably 1 mm or less, and more preferably 0.5 mm or less. This is because the catheter or the like in which the operation wire 10 is incorporated is made thinner, and the structure of the operation wire of this embodiment is particularly advantageous when the wire diameter is small. On the other hand, the diameter D of the wire body is preferably 0.04 mm or more, and more preferably 0.08 mm or more. This is because if the wire diameter is too small, the required tensile strength cannot be obtained.

  Although the latching | locking part 12 may be formed in a part of circumferential direction of the wire main body 11 side surface, Preferably it is formed over the perimeter of the circumferential direction of a wire main body side surface. This is because the area of the interface between the wire body and the plating layer is large and the bonding strength is increased. The shape of the locking portion is preferably a substantially cylindrical shape concentric with the wire body and is rotationally symmetric about the central axis. This is because it is not necessary to consider the direction of the operation wire during the joining operation with the counterpart member, so that the medical device can be easily assembled. When the shape of the locking portion is substantially cylindrical, referring to FIG. 2, an angle formed by a plane P in contact with the locking portion end surface 14 opposite to one end of the wire body and the center line Z of the wire body. θ is preferably 90 ° ± 2 °, more preferably 90 ° ± 1 °. This is because if the angle θ is greatly deviated from 90 degrees, a force is generated in the direction of twisting the wire when the operation wire is used, and the operation wire does not smoothly advance and retract.

  Returning to FIG. 1, the material of the plating layer 13 constituting the locking portion 12 is preferably nickel. This is because it has sufficient hardness and excellent corrosion resistance. Moreover, when using an austenitic stainless steel wire as a wire main body, it is especially preferable that a plating layer is nickel. This is because high bonding strength can be obtained.

  The length L of the locking portion 12 is preferably 8 mm or less, more preferably 4 mm or less, and particularly preferably 2 mm or less. This is because the shorter the length L, the smaller the medical device. On the other hand, if the locking portion is too short, the required strength cannot be obtained. Therefore, the length of the locking portion is preferably 0.2 mm or more, more preferably 0.5 mm or more.

  The thickness t of the locking portion 12 is preferably 0.1 mm or less. This is because the thinner the locking portion, the smaller the medical device. On the other hand, the thickness t of the locking portion 12 is preferably 0.01 mm or more, more preferably 0.025 mm or more. This is because if the locking portion is too thin, the processing accuracy required for the locking portion and the counterpart member increases. When the wire body 11 is a stranded wire, the cross section perpendicular to the length direction is not a perfect circle due to the twisted shape, and the outer surface of the locking portion is also affected by the twisted shape. At this time, the thickness t of the locking portion refers to the radial distance from the surface of the wire in contact with the circumscribed circle of the cross section of the wire body to the outer surface of the locking portion. In particular, when the locking portion is substantially cylindrical and concentric with the wire body, the thickness t of the locking portion is the difference between the radius of the circumscribed circle of the cross section of the wire body and the radius of the circumscribed circle of the cross section of the locking portion. Become.

  Next, the manufacturing method of the operation wire of this embodiment is demonstrated based on FIG.

  First, referring to FIG. 3A, a wire body 11 is prepared. Referring to FIG. 3B, the first mask layer 21 is formed on the side surface near the tip of the wire in a range longer than the locking portion to be formed. The first mask layer can be formed, for example, by pad printing a heat resistant resist ink from a plurality of directions on the wire body. According to pad printing, even when a stranded wire is used as the wire body, the ink penetrates into the recesses on the surface, and the edge Q shape of the first mask layer is not easily jagged. Referring to FIG. 3C, a second mask layer 22 is formed at the tip of the wire. Although the formation method of a 2nd mask layer is not specifically limited, Preferably it forms by electrodeposition coating. In the case of electrodeposition coating, the second mask layer is formed on the exposed portions of the wire body on both sides of the first mask layer. According to the electrodeposition coating, a second mask layer having excellent adhesion to the wire body can be obtained. Referring to FIG. 3D, after the second mask layer is cured by heating, UV irradiation, or the like, the first mask layer is removed. Referring to FIG. 3E, the tip end side of the wire is immersed in a plating bath to form a plating layer 13. The plating layer is preferably formed by electrolytic plating. This is because a uniform plating thickness can be obtained. More preferably, the plating layer is formed by electrolytic plating using a sulfamic acid bath. This is because the internal stress of the plating layer can be reduced. Referring to FIG. 3F, the second mask layer is removed. The second mask layer can be removed using a release agent. With reference to FIG. 3G, the ends of the wire main body and the plating layer are cut so that a locking portion 12 having a desired length L is obtained.

  Next, the usage method of the operation wire of this embodiment is demonstrated.

  In FIG. 4, concave portions (locking receiving portions) 24 are formed at two opposing positions on the outer peripheral surface of the distal end side member 23 such as a catheter. The locking portion 12 at the distal end of the operation wire 10 is fitted into the locking receiving portion. A cylindrical holding ring 25 is fitted to the outside of the distal end side member to hold the locking portion 12 so that it does not come off the locking receiving portion 24. The whole of the distal end side member, the operation wire, and the pressing ring is further accommodated in a flexible tube or the like. By operating the two operation wires back and forth from the proximal end, the direction of the distal end member is changed, whereby the curvature of the catheter or the like can be controlled.

  In addition, the method of joining the latching | locking part of an operation wire with a front end side member is not restricted to the structure of FIG. For example, when there is a cavity inside the tip side member, a latch receiving portion is provided on the inner peripheral surface of the tip side member, the latching portion of the operation wire is fitted from the inside, and the pressing member is inserted into the cavity, The locking portion may be pressed from the inside. Also, as the latch receiving portion, a through hole having a size that passes through the wire body but not through the latch portion is formed in the tip side member, and a wire is inserted into the through hole from the distal side to It may be locked to the edge of the through hole.

  As the wire body, a stranded wire having a diameter of 0.21 mm in which seven austenitic stainless steel wires were twisted together was used. The wire has a wire diameter of 0.07 mm and has a tensile strength improved by work hardening in the same manner as SUS304WPB defined in JIS G4314. The tensile strength of the wire body was about 50N. By the above-described method, a cylindrical locking portion made of a nickel plating layer was formed on the side surface of one end of the wire body. As for the size of the locking portion, the length L was 1.5 mm, and the thickness t was 0.05 mm.

  Using a jig having a through hole through which the wire main body passes but not through the locking portion, a wire was inserted into the through hole, and the jig and the wire main body were gripped to perform a tensile test. The tensile strength of the wire body was not reduced, and the locking portion was not damaged before the wire broke. From this result, it was confirmed that the locking portion had sufficient strength.

  When the wire is fixed to the counterpart member by brazing or welding, the internal strain of the wire due to work hardening is annealed, and the tensile strength of the wire is reduced. When the same wire as in the example was fixed to another member by laser welding, the tensile strength of the wire in the vicinity of the fixed portion was reduced to about 20N. On the other hand, in the operation wire of the present example, since the wire body was not heated when the locking portion was formed, the tensile strength of the wire body did not decrease. Further, when the diameter of the wire main body is reduced to 0.21 mm, sufficient crimping strength cannot be obtained only by caulking a tubular member or the like.

  As described above, according to the operation wire of the present embodiment, sufficient bonding strength with the counterpart member can be obtained even if the wire is thin. Moreover, since it is only necessary to lock the locking portion to the mating member in order to join the operation wire and the mating member, other parts are not required, a small joining structure can be realized, and the joining work is also easy. .

  The present invention is not limited to the above-described embodiments and examples, and various modifications are possible within the scope of the technical idea.

DESCRIPTION OF SYMBOLS 10 Operation wire 11 Wire main body 12 Locking part 13 Plating layer 14 End surface of locking part 21 First mask layer 22 Second mask layer 23 Tip side member 24 Locking receiving part 25 Holding ring D Wire body diameter L Locking part Length t thickness of locking part

Claims (8)

A wire body;
A locking portion formed on a side surface of one end of the wire body and made of a plating layer,
Having operation wire. The wire body is a stranded wire,
The operation wire according to claim 1. The locking portion has a substantially cylindrical shape;
The operation wire according to claim 1 or 2. The length of the locking portion is 8 mm or less,
The operation wire according to any one of claims 1 to 3. The diameter of the wire body is 1 mm or less, and the thickness of the locking portion is 0.01 mm or more and 0.1 mm or less.
The operation wire according to any one of claims 1 to 4. The plating layer includes nickel;
The operation wire according to any one of claims 1 to 5. The operation wire is used by being incorporated in a medical device,
The operation wire according to any one of claims 1 to 6. Preparing the wire body;
Forming a first mask layer on a side surface near the tip of the wire body;
Forming a second mask layer on side surfaces of the wire body on both sides of the first mask;
Removing the first mask layer;
Forming a plating layer on the portion where the first mask layer is removed;
Removing the second mask layer;
Cutting the wire main body and the tip side of the plating layer to form a locking portion of a predetermined length;
The manufacturing method of the operation wire which has.

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