JP2006181180A - Connecting guide wire and manufacturing method for connecting guide wire - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a highly reliable connecting guide wire which has a very small diameter and prevents the breaking of a connecting part. <P>SOLUTION: In the connecting guide wire 3 constituted by connecting a wire 27 of a main body and an extension wire 28 at a connecting part 31, the connecting part 31 is characterized with a connection welding part 30 provided between an end 27a of the wire 27 of the main body and an end 28a of the extension wire 28 by welding and a connection auxiliary member 34 which is placed over the connection welding part 30 and is fixed to the wire 27 of the main body and the extension wire 28 by welding. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a connection guide wire used for, for example, a medical instrument and a method for manufacturing the connection guide wire.

  In general, as a guide wire used for a medical instrument or the like, there are an operation wire for operating a bending portion of an endoscope, a wire for a treatment instrument inserted into a channel of an endoscope, and the like. As a guide wire used in such a form, a body wire having a certain degree of flexibility and rigidity is used on the hand operation side, and a flexible extension wire is used on the distal end side. A connecting guide wire in which a main body wire and an extension wire are connected via a connecting portion is often used.

As such a connecting guide wire, one having a structure in which end surfaces of metal wires are abutted with each other and a butt portion is welded by irradiating a laser beam is disclosed (for example, see Patent Document 1).
Also disclosed is a technique in which end faces of a wire formed by bundling a plurality of strands and a wire made of a single wire are abutted and this abutting portion is laser-welded (for example, see Patent Document 2).
Furthermore, there is also disclosed a core wire that protrudes from the end portions of a pair of guide wires and a metal pipe in which these core wires are inserted from both end portions, and each core wire is welded to the metal pipe. (For example, refer to Patent Document 3).

Here, in recent years, with the miniaturization and thinning of medical instruments and the like, it has been required to reduce the diameter of the connecting guidewire itself. On the other hand, since a mechanical external force such as pulling, bending, friction, and twisting is applied to the connecting guide wire during operation, the connecting portion is required to have a predetermined strength so that the connecting portion does not break. ing.
JP-A-8-19883 JP-A-10-201704 JP 2000-84088 A

  However, in the connection guide wire having the above structure, when the diameter is reduced, a heat-affected portion due to heat input at the time of welding easily spreads, so that material deterioration or softening occurs in the connection portion, and strength against external force is reduced. There is a problem of end up.

  The present invention has been made in view of such circumstances, and a highly reliable connecting guide wire and a manufacturing method of the connecting guide wire that can prevent breakage of the connecting portion while reducing the diameter. The purpose is to provide.

In order to solve the above problems, the present invention provides the following means.
According to the first aspect of the present invention, in the connecting guide wire configured by connecting the main body wire and the extension wire by the connecting portion, the connecting portion is provided by welding between one end of the main body wire and one end of the extension wire. A connecting auxiliary member fixed to the main body wire and the extension wire by welding across the connecting welding portion.

In the connection guide wire according to the present invention, the main body wire and the extension wire are connected via the connection welding portion, and the connection auxiliary member is fixed to the main body wire and the extension wire by welding across the connection welding portion. .
Thereby, even if external force is added to the connection part of a main body wire and an extension wire, the external force can be disperse | distributed to a connection welding part and a connection auxiliary member, and the intensity | strength of the whole connection part can be increased.

  According to a second aspect of the present invention, in the connection guide wire according to the first aspect, the connection auxiliary member is any one of a rod shape, a semi-cylindrical shape, and a cylindrical shape.

In the connection guide wire according to the present invention, the connection auxiliary member is formed in any one of a rod shape, a half tube shape, and a tube shape. And the both ends of the connection auxiliary member of those shapes are each fixed to a main body wire and an extension wire.
Thereby, a connection auxiliary member can be fixed easily and reliably across a connection welding part. In particular, when a semi-cylindrical shape or a cylindrical shape is used, not only the welding operation is facilitated, but also the breaking force amount of the connecting portion can be further increased.

  According to a third aspect of the present invention, in the connection guidewire according to the first aspect, the connection auxiliary member has a cylindrical shape, and an opening is formed in a peripheral wall portion thereof.

In the connection guide wire according to the present invention, when the main body wire and the extension wire are passed through the connection auxiliary member, the ends of the main body wire and the extension wire are exposed from the opening.
Thereby, not only the intensity | strength of a connection part can be increased, but the welding operation | work of a main body wire and an extension wire can be performed much more easily.

  The invention according to claim 4 is the connection guidewire according to any one of claims 1 to 3, wherein the cross-sectional area of the connection auxiliary member is a cross-sectional area of the main body wire and a cross-sectional area of the extension wire. Of these, the cross-sectional area of the smaller one is set to be equal to or smaller than that.

In the connection guide wire according to the present invention, the cross-sectional area of the connection auxiliary member is set equal to or smaller than the smaller cross-sectional area of the cross-sectional area of the main body wire and the cross-sectional area of the extension wire. Therefore, even if the stress acts on the main body wire and the extension wire due to the distortion of the coupling auxiliary member, the stress is weaker than the limit holding force that does not cause the main body wire and the extension wire to bend.
As a result, even if thermal distortion or the like occurs in the connection auxiliary member due to heat input at the time of welding, deformation such as bending or displacement of the main body wire and the extension wire can be prevented.

  According to a fifth aspect of the present invention, in the connection guidewire according to any one of the first to fourth aspects, a welding heat input amount during welding of the connection auxiliary member is a welding amount during welding of the connection welding portion. It is characterized by being set equal to or less than the heat input.

In the connection guide wire according to the present invention, the welding heat input amount during welding of the connection auxiliary member is set to be equal to or less than the welding heat input amount during welding of the connection welding portion. Therefore, it is possible to prevent the thermal effect of the welded portion of the connection auxiliary member during welding from reaching the entire radial direction of the wire.
Thereby, the range which the heat influence of the welding part of a connection auxiliary | assistant member can be made small, and material deterioration or softening can be suppressed.

Shrinkage can be reduced, and deformation such as bending and displacement of the main body wire and the extension wire due to the contraction force can be prevented.

  The invention according to claim 6 is a method of manufacturing a connecting guide wire in which a main body wire and an extension wire are connected by a connecting portion, and a connecting step of connecting one end of the main body wire and one end of the extension wire by welding; A fixing step of fixing a connection auxiliary member by welding to the main body wire and the extension wire across a connecting weld portion between one end of the main body wire and one end of the extension wire connected by the connecting step. It is characterized by.

In the manufacturing method of the connection guide wire according to the present invention, in the connection step, one end of the main body wire and one end of the extension wire are connected by welding, and a connection welding portion is provided between one end of the main body wire and one end of the extension wire. Provided. And a connection auxiliary member is fixed to a main body wire and an extension wire by welding across the connection welding part by a fixing process.
As a result, even when an external force is applied to the connection portion between the main body wire and the extension wire, the external force can be distributed to the connection welding portion and the connection auxiliary member, and the connection guide can increase the strength of the entire connection portion. A wire can be obtained easily.

  According to the present invention, even if an external force is applied to the connecting portion, the external force can be dispersed. Therefore, the connecting portion can be prevented from being broken while the main body wire and the extension wire are reduced in diameter, and reliability is improved. Can be improved.

Example 1
Hereinafter, a connection guide wire according to a first embodiment of the present invention will be described with reference to the drawings. In the present embodiment, a case where the connection guide wire is used as an operation wire of a treatment tool used together with an endoscope apparatus will be described as an example. In FIG. 1, reference numeral 1 denotes an endoscope apparatus, reference numeral 2 denotes a treatment instrument, and reference numeral 3 denotes a connecting guide wire.
First, the endoscope apparatus 1 and the treatment tool 2 to which the connection guide wire 3 according to the present invention is applied will be described.

The endoscope apparatus 1 includes an elongated insertion portion 5 that is inserted into a body cavity, and an operation portion 10 that is disposed at the proximal end of the insertion portion 5 and operates the insertion portion 5.
The insertion portion 5 includes a hard distal end portion 6, a bendable bending portion 7 provided at the proximal end of the distal end portion 6, and a long flexible portion extending from the proximal end of the bending portion 7 to the operation portion 10. 8 and. In the insertion portion 5, a channel 16 is provided that extends across the insertion port 17 and the distal end portion 6 provided in the middle of the flexible portion 8.
The operation unit 10 includes a bending operation knob 12, and by operating the bending operation knob 12, the bending unit 7 can be bent in any direction in the vertical and horizontal directions. Furthermore, the operation unit 10 is provided with a universal cord 14 and is connected to an endoscope body (not shown).

The treatment instrument 2 includes a main body 21 having an operation ring 24 and a sheath tube 22 extending from the main body 21. In the sheath tube 22, the connection guide wire 3 according to the present invention is provided so as to be able to advance and retreat, and one end of the connection guide wire 3 is attached to the operation ring 24 in the main body portion 21. A forceps portion 23 is attached to the other end.
Under such a configuration, the forceps portion 23 is inserted into the channel 16 from the insertion port 17 toward the distal end portion 6, and the forceps portion 23 appears from the distal end portion 6. In this state, when the operation ring 24 is removed from the main body 21, the forceps 23 is opened and closed.

Next, the connection guide wire 3 according to the present invention will be described.
As shown in FIGS. 2 and 3, the connecting guide wire 3 includes a main body wire 27 having both flexibility and rigidity, and an extension wire 28 having flexibility, and the main body wire 27 and the extension wire 28. Are connected by a connecting portion 31. In addition, the manufacturing method of this connection guide wire 3 is mentioned later.

  The main body wire 27 and the extension wire 28 are made of, for example, an elastic material such as stainless steel, piano wire, or superelastic alloy, and the type of the wire may be either a single wire or a stranded wire. The outer diameter of the main body wire 27 and the extension wire 28 is set to several mm or less, and is preferably about 0.1 to 1.0 mm, for example. However, the extension wire 28 requiring flexibility has a smaller diameter than the main body wire 27 or has a larger number of wires. Furthermore, the length dimensions of the main body wire 27 and the extension wire 28 are not particularly limited, but the main body wire 27 is preferably about 100 to 5000 mm, and the extension wire 28 is preferably about 20 to 1000 mm.

  The main body wire 27 and the extension wire 28 are connected by butt welding. That is, for example, a connection welding portion 30 is provided between one end surface 27a of the main body wire 27 and one end surface 28a of the extension wire 28 by laser welding, arc welding, resistance welding or the like. The wire 27 and the extension wire 28 are connected concentrically.

Furthermore, the connection part 31 in a present Example is provided with the rod-shaped connection auxiliary member 34 by which the cross-sectional shape was formed circularly. The connection auxiliary member 34 is fixed to the main body wire 27 and the extension wire 28 across the connection welding portion 30. That is, one end of the connection auxiliary member 34 in the length direction is fixed to the surface layer surface of the main body wire 27 by welding, and the other end is fixed to the surface layer surface of the extension wire 28 by welding. Thus, fixed welds 35 extending to the main body wire 27 and the extension wire 28 are provided at both ends of the connection assisting member 34, respectively. In this case, the welding heat input Q ₂ during welding when providing the fixing welds 35 is set smaller than the welding heat input to Q ₁ when providing the connecting welds 30. For example, the welding heat input ratio Q ₂ / Q ₁ is preferably about ¼ to ¾.

Moreover, the connection auxiliary member 34 is made of the same kind of elastic material as that of the main body wire 27 and the extension wire 28, such as stainless steel, piano wire, and superelastic alloy. The length dimension of the coupling auxiliary member 34 is not particularly limited as long as it is a dimension that is fixed to the main body wire 27 and the extension wire 28 across the coupling welded portion 30. For example, it is about 3 to 10 mm. preferable. Further, the cross-sectional area of the coupling auxiliary member 34 is set to be smaller than the cross-sectional area of the smaller one of the cross-sectional areas of the main body wire 27 and the extension wire 28, that is, the cross-sectional area of the extension wire 28.
Under such a configuration of the connecting guide wire 3, the other end of the main body wire 27 is attached to the operation ring 24 shown in FIG. 1, and the forceps portion 23 is attached to the other end of the extension wire 28.

Next, the manufacturing method of the connection guide wire 3 as described above will be described with a focus on the process of connecting the main body wire 27 and the extension wire 28 among all the processes.
First, in the forming process, the main body wire 27, the extension wire 28, and the connection assisting member 34 are formed.
In the connecting step, the one end surface 27a of the main body wire 27 and the one end surface 28a of the extension wire 28 are arranged to face each other, and the both end surfaces 27a, 28a are welded by, for example, laser welding, arc welding, resistance welding or the like. The Thereby, the connection welding part 30 is provided between the one end surface 27a of the main body wire 27 and the one end surface 28a of the extension wire 28, The main body wire 27 and the extension wire 28 are mutually concentric by this connection welding part 30. Connected to each other.

In the fixing step, the connection auxiliary member 34 is brought into contact with the surface layers of the main body wire 27 and the extension wire 28 so as to straddle the connection welding portion 30. From this state, one end of the connection auxiliary member 34 in the length direction is fixed to the surface layer surface of the main body wire 27 by welding, and the other end is fixed to the surface layer surface of the extension wire 28 by welding. Thereby, the fixed welding part 35 is provided in the both ends of the connection auxiliary member 34. As shown in FIG. Further, the welding heat input Q ₂ at this time is set smaller than the welding heat input to Q ₁ when provided with a connecting weld 30. For example, the welding heat input ratio Q ₂ / Q ₁ is set to about ¼ to ¾.
Thereby, the above-described connection guide wire 3 in which the main body wire 27 and the extension wire 28 are connected by the connection welding portion 30 and the connection auxiliary member 34 is obtained.

Next, the operation of the connection guide wire 3 in the present embodiment configured as described above will be described in accordance with the operation of the endoscope apparatus 1 and the treatment tool 2.
First, the forceps portion 23 is inserted into the channel 16 from the insertion port 17 shown in FIG. 1, and the main body portion 21 is pushed in until the forceps portion 23 reaches a predetermined position where it does not appear from the distal end portion 6. At this time, the forceps 23 is pushed through the connection guide wire 3, and the pushing force is transmitted to the entire connection guide wire 3 by the main body wire 27 having flexibility and rigidity.
Subsequently, the insertion unit 5 is inserted into the body cavity while grasping the operation unit 10. Then, by operating the bending operation knob 12 while observing an observation image displayed on a monitor provided in the endoscope body, the bending portion 7 is bent and the distal end portion 6 is directed in a desired direction. At this time, the connecting guide wire 3 is also bent, but the insertion portion 5 is easily bent by the flexible extension wire 28.
And it is confirmed that the front-end | tip part 6 is arrange | positioned facing a target object via a monitor.

In this state, the main body portion 21 is pushed in so that the forceps portion 23 appears from the distal end portion 6. Then, when the operation ring 24 is extracted from the main body 21 with a finger or the like, the forceps 23 are closed to each other via the connection guide wire 3. At this time, the connection guide wire 3 is pulled by the operation ring 24 while being rubbed against the inner peripheral surface of the sheath tube 22.
Then, the object is gripped by the forceps 23 and the treatment tool 2 is pulled out from the insertion port 17 as it is, so that the object is extracted to the outside.
Then, a predetermined treatment is performed and a series of work is completed.

Here, when the endoscope apparatus 1 and the treatment tool 2 are operated, various mechanical external forces such as pulling, bending, friction, and twisting act on the connection guide wire 3. On the other hand, when connected by welding, material deterioration and softening may occur due to thermal effects, and the strength of the connecting portion 31 may decrease.
In the present embodiment, the strength of the connecting portion 31 against these external forces is sufficiently ensured as follows.

  That is, for example, when the operation ring 24 is extracted from the main body portion 21, a tensile force acts on the connecting portion 31 through the main body wire 27, but the connecting portion 31 is fixed across the connecting welded portion 30. Since the connection auxiliary member 34 is provided, the tensile force is distributed to the connection portion 31 and the connection weld portion 30. Therefore, the tensile force acting on the connection welding part 30 decreases, and the strength of the connection part 31 as a whole increases.

Next, generally, when metal or the like is welded, there is a possibility that stress is generated due to thermal distortion of the welded body due to the influence of heat. In addition, while the welded portion expands due to heat, when the temperature cools down with a lapse of a predetermined time, the welded portion shrinks, and thus a shrinkage force is generated in the welded portion.
In this embodiment, since the cross-sectional area of the connection auxiliary member 34 is set smaller than the cross-sectional area of the extension wire 28, the connection auxiliary member 34 is distorted by heat input during welding of the connection auxiliary member 34. Even if the stress acts on the main body wire 27 and the extension wire 28, the stress becomes weaker than the limit holding force of the main body wire 27 and the extension wire 28. Moreover, since the cross-sectional area is set small, the fixed welded portion 35 can be small, and its contraction force is also small.

Further, since the welding heat input Q ₂ during welding when providing the fixing welds 35, is set smaller than the welding heat input to Q ₁ when providing the connecting weld 30, the thermal influence of the fixed welding unit 35 Is prevented from extending over the entire radial direction of the main body wire 27 or the extension wire 28. Therefore, material deterioration or softening is partially suppressed in the vicinity of the fixed weld portion 35.

  As described above, according to the connection guide wire 3 in the present embodiment, even if an external force is applied to the connection portion 31, the external force can be distributed to the connection welding portion 30 and the connection auxiliary member 34. Can be increased. Therefore, it is possible to prevent breakage of the connecting portion 31 while reducing the diameter of the main body wire 27 and the extension wire 28, and to improve the reliability.

  Further, by setting the cross-sectional area of the coupling auxiliary member 34 to be smaller than the cross-sectional area of the extension wire 28, stress due to distortion of the coupling auxiliary member 34 becomes weaker than the limit holding force of the main body wire 27 and the extension wire 28. Therefore, it is possible to prevent the main body wire 27 and the extension wire 28 from being bent or displaced. Further, by setting the cross-sectional area to be small, the fixed welded portion 35 can be made small and the contraction force thereof can be made small, so that it is also possible to prevent the main body wire 27 and the extension wire 28 from being bent or displaced. .

Furthermore, since the welding heat input Q ₂ is set to be smaller than the welding heat input Q ₁ and the fixed weld 35 is provided on a part of the entire circumference of the main body wire 27 and the extension wire 28, The influence is prevented from reaching the entire radial direction of the main body wire 27 and the extension wire 28, and material deterioration and softening can be suppressed.
In addition, the connection guide wire 3 can be easily obtained by the connection step and the fixing step.

In the present embodiment, the cross-sectional shape of the coupling auxiliary member 34 is circular, but is not limited to this, and can be changed as appropriate, such as a polygon such as a triangle or a quadrangle, or an ellipse. .
In addition, although one connection auxiliary member 34 is provided, the present invention is not limited to this, and the number of installation can be changed as appropriate. For example, as shown in FIGS. 4 and 5, two connection assisting members 34 may be provided. At this time, it is preferable that the plurality of connection assisting members 34 are arranged at equal intervals in the circumferential direction of the main body wire 27 and the extension wire 28.

(Example 2)
Next, a second embodiment of the present invention will be described.
6 and 7 show a second embodiment of the present invention.
6 and 7, the same components as those shown in FIGS. 1 to 5 are denoted by the same reference numerals, and the description thereof is omitted.
This embodiment and the first embodiment have the same basic configuration, and differ in the following points.

  That is, the connection assisting member 34 in the present embodiment is formed in a semi-cylindrical shape, and the longitudinal semi-inner peripheral surface 37 disposed on the inner side thereof is installed along the surface layers of the main body wire 27 and the extension wire 28. Yes. Both ends of the connection auxiliary member 34 in the length direction are fixed to the main body wire 27 and the extension wire 28 by fixed welding portions 35.

As described above, since the connection assisting member 34 is formed in a semi-cylindrical shape, when the connection assisting member 34 is installed so as to cover the connection welding portion 30, the position is easily maintained. The welding operation can be facilitated.
Moreover, since the connection auxiliary member 34 can be installed so as to cover the surface layers of the main body wire 27 and the extension wire 28, the thickness dimension of the connection auxiliary member 34 can be suppressed, and the operation can be caught. Can be prevented, and operability can be improved.

(Example 3)
Next, a third embodiment of the present invention will be described.
8 and 9 show a third embodiment of the present invention.
The connection auxiliary member 34 in the present embodiment is formed in a cylindrical shape, and the main body wire 27 and the extension wire 28 are passed through the cylindrical hole 36 and fixed by the fixed welding portion 35 at a position straddling the connection welding portion 30. Has been. Prior to the insertion of the main body wire 27 and the extension wire 28, the connection welding portion 30 may be formed by butt welding in advance, but after the main body wire 27 and the extension wire 28 are inserted into the connection auxiliary member 34, the connection is performed. It is also possible to form the auxiliary member 34 by heat input from the outer periphery of the central portion. Moreover, the fixed welding part 35 is provided in two places at equal intervals in the circumferential direction.

As described above, since the connection assisting member 34 is formed in a cylindrical shape and can be welded through the main body wire 27 and the extension wire 28, the welding operation can be further facilitated.
Moreover, since the external force which acts on the connection auxiliary member 34 can be disperse | distributed to the perimeter, the intensity | strength of the connection part 31 can be increased.
Furthermore, since the fixed welded portions 35 are provided at two locations at equal intervals in the circumferential direction, it is possible to prevent the thermal influence during welding from reaching the entire radial direction of the main body wire 27 and the extension wire 28. It is possible to suppress material deterioration and softening, and to install the connection auxiliary member 34 in a well-balanced manner.

Example 4
Next, a fourth embodiment of the present invention will be described.
10 and 11 show a fourth embodiment of the present invention.
This embodiment and the third embodiment have the same basic configuration and are different in the following points.

  That is, a rectangular opening 38 is formed at the center in the length direction of the peripheral wall 39 in the connection assisting member 34 in the present embodiment. The width dimension of the opening 38 in the direction orthogonal to the length direction is set larger than the outer diameters of the main body wire 27 and the extension wire 28. The connection assisting member 34 is fixed at a position where the opening 38 coincides with the connection welding portion 30, so that the connection welding portion 30 is exposed from the opening 38.

  Using this opening 38, the main body wire 27 and the extension wire 28 are connected as follows. That is, the main body wire 27 and the extension wire 28 are respectively inserted from both ends of the connection assisting member 34. Then, both end surfaces 27 a and 28 a of the main body wire 27 and the extension wire 28 are attached to each other, and the attached portions are exposed from the opening 38. From this state, the both end surfaces 27a and 28a are welded through the opening 38, and the main body wire 27 and the extension wire 28 are connected. Thereby, the connection welding part 30 is provided.

  From the above, not only the same effects as in the third embodiment can be obtained, but also welding can be performed in a state where the main body wire 27 and the extension wire 28 are inserted into the connection assisting member 34. The process can be simplified.

In this embodiment, the opening 38 is rectangular. However, the present invention is not limited to this, and the shape thereof can be changed as appropriate, for example, circular or elliptical.
Moreover, although the width dimension of the opening part 38 is set larger than the outer diameter of the main body wire 27 and the extension wire 28, it is not restricted to it and may be equivalent or less. However, it goes without saying that a larger setting can facilitate the welding operation.

In the first to fourth embodiments, the case where the connecting guide wire 3 is applied to the operation wire of the treatment instrument 2 has been described as an example. However, the present invention is not limited to the operation wire of the treatment instrument 2. Needless to say, the present invention can be applied to other wires.
Note that the technical scope of the present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the spirit of the present invention.

It is a figure which shows 1st Example of the connection guide wire which concerns on this invention, Comprising: It is explanatory drawing which shows a mode that it applied to the operation wire of a treatment tool. It is a side view which shows the connection part of the connection guide wire shown in FIG. FIG. 3 is a cross-sectional view taken along line AA in FIG. 2. It is a side view which shows the modification of the connection guide wire shown in FIG. FIG. 5 is a cross-sectional view taken along line B-B in FIG. 4. It is a side view which shows the principal part of 2nd Example of the connection guide wire which concerns on this invention. It is CC sectional view taken on the line of FIG. It is a side view which shows the principal part of the 3rd Example of the connection guide wire which concerns on this invention. It is the DD sectional view taken on the line of FIG. It is a side view which shows the principal part of the 4th Example of the connection guide wire which concerns on this invention. It is the EE arrow directional cross-sectional view of FIG.

Explanation of symbols

3 Connection Guide Wire 27 Main Body Wire 27a One End Surface (One End of Main Body Wire)
28 Extension wire 28a One end surface (one end of an extension wire)
30 connection welding part 31 connection part 34 connection auxiliary member 38 opening part 39 peripheral wall part

Claims (6)

In a connecting guide wire configured by connecting a main body wire and an extension wire by a connecting portion,
The connecting portion is a connecting weld portion provided by welding between one end of the main body wire and one end of the extension wire;
A connection guide wire comprising a connection auxiliary member fixed to the main body wire and the extension wire by welding across the connection weld.   The connection guide wire according to claim 1, wherein the connection auxiliary member has any one of a rod shape, a half tube shape, and a tube shape.   The connection guide wire according to claim 1, wherein the connection auxiliary member has a cylindrical shape, and an opening is formed in a peripheral wall portion thereof.   The cross-sectional area of the connection auxiliary member is set to be equal to or smaller than the smaller cross-sectional area of the cross-sectional area of the main body wire and the cross-sectional area of the extension wire. The connecting guide wire according to any one of the above.   The welding heat input amount at the time of welding of the connection auxiliary member is set to be equal to or less than the welding heat input amount at the time of welding of the connection welded portion, according to any one of claims 1 to 4. The connecting guidewire as described. In the manufacturing method of the connecting guide wire constituted by connecting the main body wire and the extension wire by the connecting portion,
A connecting step of connecting one end of the main body wire and one end of the extension wire by welding;
A fixing step of fixing a connection auxiliary member by welding to the main body wire and the extension wire across a connection welding portion between one end of the main body wire and one end of the extension wire connected by the connection step. A method for manufacturing a connected guide wire.

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