JPH11155871A - Treatment tool for endoscope - Google Patents

Abstract

PROBLEM TO BE SOLVED: To cover a part of a contact coil which is deteriorated by influence of heat in welding with a connecting ring to be effectively protected, and to reduce the length of a hard part produced by installing the connecting ring by fitting two tight contact coils mutually connected to a connecting ring where a through hole is formed in the peripheral drum part, and performing spot welding after confirmation on a joint part of both tight contact coils through a through hole. SOLUTION: Tight contact coils 20a, 20b forming a flexible shaft 20 are inserted in a connecting ring 21, and joined to each other in such a manner that the end parts of the tight contact coils 20a, 20b closely adhere to each other. A through hole for confirming the joining state and the joining position from the outside is bored in the connecting ring 21, and after such confirmation through the through hole 22 is performed, spot welding is applied to the joining part between the contact coils 20a, 20b by a laser welding device 23. Thus, the joining part between the connecting ring 21 and the contact coils 20a, 20b is welded.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a treatment tool for an endoscope, such as forceps, which is inserted into a treatment tool insertion channel of an endoscope.

[0002]

2. Description of the Related Art An endoscope used for medical purposes or the like is constructed by connecting an insertion part into a body cavity or the like to a main body operation part for an operator or the like to perform an operation by grasping with a hand. At the distal end portion of the insertion portion, an illuminating means for illuminating at least the inside of a body cavity, etc.
And an observation unit for performing a predetermined observation under illumination by the illumination unit. The structure of the insertion portion includes a rigid endoscope made of a hard pipe and a flexible endoscope that bends in an arbitrary direction along the insertion path. In the flexible endoscope, most of the insertion section from the side connected to the main body operation section is composed of a flexible section that bends in an arbitrary direction along the insertion path, and the flexible section includes an angle section and an angle section. Is provided with a continuous hard end portion. The illuminating means and the observation means described above are provided at the distal end hard portion, and constitute an extremely short hard portion with respect to the entire insertion portion. The angle portion is configured to be able to bend in a desired direction on the hand side, that is, the main body operation portion side, in order to direct the hard distal end portion in an arbitrary direction.

[0003] When the insertion portion of the endoscope is inserted into the body cavity, the inner wall of the body cavity and the like are observed. As a result of the observation, if a site to be treated such as the affected site is found, the affected site is removed. If a site suspected of an affected site is found, cells or the like at the site are collected. Since such an operation needs to be performed under monitoring by the endoscope, the endoscope is provided with a treatment instrument insertion channel. The treatment tool insertion channel is connected to a treatment tool introduction section provided in the main body operation section, extends over the entire length of the insertion section, and opens to a hard distal end portion provided with observation means and the like.

A typical example of a treatment tool inserted into the treatment tool insertion channel is a forceps shown in FIG. Here, the endoscope through which the forceps are inserted is a flexible endoscope in which an insertion portion bends in an arbitrary direction along the insertion path. In the figure, reference numeral 1 denotes a forceps, and the forceps 1 includes a pair of gripping claws 2 as an operating member.
This gripping claw 2 is provided with a link member 4 at the end of the flexible cable 3.
It is provided so as to be connected via. Flexible cable 3
In this example, an operation wire 6 for opening and closing the gripping claws 2 is inserted into a flexible shaft 5 formed of a close contact coil formed by winding a metal wire in a close contact spiral shape. A control member for pushing and pulling the operation wire 6 is formed at the base end of the flexible cable 3. An opening and closing operation unit 7 for pushing and pulling the operation wire 6 is provided at the base end of the flexible cable 3.

Here, the flexible cable 3 bends in an arbitrary direction along the insertion path, that is, has flexibility, but the flexibility imparted to the flexible cable 3 is It need not be uniform over its entire length, but rather has a varying degree of flexibility in the axial direction. As described above, in the insertion portion of the endoscope, an angle portion is provided in the vicinity of the distal end, and this angle portion is for directing the rigid distal portion in a desired direction, and is 180 ° Some are configured to be bent at more angles. Therefore, the flexible cable 3 of the forceps 1
If the flexibility of the distal end side from the portion located at the angle portion of the endoscope is not further improved, the operation of inserting the forceps 1 into the treatment instrument insertion channel will be hindered, and the forceps 1 will be inserted. When bending the angle portion in the bent state, the resistance increases. On the proximal end side from this part, the operation of pushing the forceps 1 into the treatment instrument insertion channel becomes easier if the user has a certain degree of waist. Further, the portion located outside the treatment instrument introduction section provided on the main body operation section is further strengthened to ensure smoothness of the opening / closing operation of the gripping claws 2 performed by gripping the opening / closing operation section 7.

As described above, the flexible cable 3 has at least two steps, preferably 3 steps, in the axial direction.
It is necessary to vary the degree of flexibility over the stages. In order to change the degree of flexibility, it is necessary to change the wire diameter of the metal wire constituting the close contact coil, or to change the material of the metal wire itself. Therefore, one flexible shaft 5 is formed by adding together the close-contact coils formed by dividing the close-contact coils having different properties into two or three in the axial direction, and the operation wire 6 is provided in the flexible shaft 5. The flexible cable 3 is formed by being inserted.

As described above, in order to form the flexible shaft 5, it is necessary to join a plurality of close-contact coils and fix them together. The following two types are conventionally used as typical examples of the bonding and fixing method of the contact coil. First
Is, as shown in, for example, Japanese Patent Publication No. 7-59236, a method in which two close-contact coils are joined so as to abut each other, and this joint portion is directly welded. Another joining and fixing method is a ring-fitting method, which is disclosed, for example, in Japanese Patent Publication No. 5-60752. The bonding and fixing method using this ring is configured as shown in FIG. That is, a metal connecting ring 8 is fitted to the connecting portion of the two close-contact coils 5a and 5b constituting the flexible shaft 5, and the connecting ring 8 is provided.
Of using a welding means from the outside, and the position W ₁ between one tightly wound coil 5a which is inserted into the coupling ring 8, and a position W ₂ between the coupling ring 8 and the other contact coil 5b Some are configured to perform welding at two locations.

[0008]

Of the above-mentioned two types of bonding and bonding methods of the close contact coils, the method of directly welding the connection portion between the close contact coils involves the joint portion and its vicinity due to the influence of heat due to welding. Will be in an annealed state,
It becomes weaker than other parts and its strength decreases. Therefore, when an external force such as a collision with another object is applied during use of the treatment instrument, there is a possibility that the treatment instrument may be easily broken at this portion. In Japanese Patent Publication No. Hei 7-59236, the effect of heat is eliminated as much as possible by performing the welding by laser spot welding. However, since the heat directly acts on the contact coil, there is a certain degree of variation in the welded portion. Vulnerability cannot be avoided.

On the other hand, in the system disclosed in Japanese Patent Publication No. Hei 5-60752, the portion of the contact coils 5a and 5b where heat is applied during welding is located inside the connecting ring 8, and the connecting ring 8 As a result, no external force acts directly on this portion, and there is no problem in the strength of the connecting portion between the two close-contact coils 5a and 5b. However, since the connecting ring 8 is a hard member, a hard portion is formed at an intermediate position of the flexible cable 3. Here, the connecting ring 8 has two axial
Since welding points W ₁ and W ₂ are formed and the surroundings are affected by heat during welding, the connecting ring 8 is formed.
Can not be welded in the vicinity of the end portion, the weld portion W _1, W ₂
From each position to the end face of the connection ring 8
_1, it is necessary to provide a L _1. Therefore, in addition to these dimension of a length obtained by adding the distance L ₂ between the welding portions W _1, W ₂ is the total length of the connection ring 8, the connecting ring 8 becomes longer in the axial direction. As a result, since the portion connected by the connecting ring 8 becomes a hard portion, if the hard portion is located in the angle portion that is largely bent at the insertion portion, not only does this hinder the operation of the angle portion, If there is a sharply bent portion in the entire insertion portion including the angle portion, there is a problem that it is difficult to pass the connecting ring 8 through this portion.

[0010] The present invention has been made in view of the above points, and an object of the present invention is to form a flexible shaft by bonding fixed coils having different properties to each other.
An object of the present invention is to make it possible to reliably reinforce a portion that is weakened by the influence of heat on a close contact coil and to prevent the generation of a hard portion that is long in the axial direction.

[0011]

SUMMARY OF THE INVENTION In order to achieve the above-mentioned object, the present invention provides a flexible shaft comprising a close-contact coil and an operating portion provided at the tip of the flexible shaft. What is claimed is: 1. A treatment tool inserted into a treatment tool insertion channel, wherein said flexible shaft is formed of contact coils having different properties so as to have a difference in flexibility in an axial direction thereof. Are connected to each other by welding means, and a connecting ring having a through hole for confirming a joint portion is fitted in a joint portion of the two closely-connected coils connected to each other. The welded portion is characterized in that it is a spot welded portion by a laser applied to the joint portion between the two closely-contacted coils confirmed by the through holes.

[0012] In order to make the contact coils joined to each other have a different degree of flexibility, for example, coils having different wire diameters,
Those having different materials can be used. In addition, the through-hole formed in the connecting ring only needs to be located at a position substantially at the intermediate position in the axial direction of the connecting ring, and in this case, the spot welding portion is also different from the portion where the through-hole is formed in the connecting ring. What is necessary is just to provide in the position of the opposite side.

[0013]

Embodiments of the present invention will be described below with reference to the drawings. Thus, as described in the prior art, the flexible shaft constituting the flexible cable in the forceps and other treatment tools is composed of a plurality of tight coils, and these tight coils are joined at their ends. In this state, it is fixed by welding means. As a treatment tool,
It is not necessarily limited to forceps as long as it has a flexible shaft having a close contact coil. FIG. 1 shows an overall configuration of a forceps as an example of a treatment tool, and FIGS. 2 and 3 show a configuration in which two front and rear close-contact coils constituting a flexible shaft are joined and fixed to each other.

First, in FIG. 1, reference numeral 10 denotes a forceps as an example of a treatment tool inserted into the treatment tool insertion channel C of the endoscope S. The forceps 10 has a gripping claw 11 provided at a distal end thereof. A flexible cable 12 is connected to the claw 11. An opening and closing operation unit 13 is provided at a base end of the flexible cable 12. Treatment instrument insertion channel C
The gripping claws 11 and the flexible cable 1
2, the portion on the proximal end side of the flexible cable 12 and the opening / closing operation section 13 are not inserted into the treatment instrument insertion channel C. In the insertion portion I of the endoscope S, length of the majority from the manipulation section O is a flexible section I _1, the angle portion I ₂ which is larger bending by the bending operation the tip of the flexible portion I ₁ It is installed continuously, and the angle part I
₂ is connected to a distal end hard portion I ₃ .

The flexible cable 12 has an operation wire (not shown) inserted through a flexible shaft 20 composed of a close-coil coil. Thereby, the gripping claws 11 are driven to open and close. Here, the degree of flexibility of the flexible shaft 20 constituting the flexible cable 12 is changed in at least two steps, preferably three steps. That is, sites extends to within the angle section I ₂ are those with the highest flexibility, site then positioned in the insertion portion I are those highly flexible behind it. Further, a portion that is not inserted into the treatment instrument insertion channel C has the lowest flexibility. As described above, in order to change the degree of flexibility, a plurality of close contact coils having different properties are connected by, for example, changing a wire diameter or changing a material.

FIGS. 2 and 3 show a connection structure of the close contact coils constituting the flexible shaft 20. FIG. In these figures, a high flexibility tightly wound coil that may be directed adhesion coil 20a in the angle portion I _2, tightly wound coil 20b
Are connected to it to form a relatively stiff, low-flex, tight-fitting coil. For example, tightly wound coil 20a, when was inserted into the endoscope provided with the treatment instrument insertion channel C, a site that may located within the angle section I _2, also tightly wound coil 20b is flexible section I ₃ It has a degree of flexibility suitable for being located inside. A third contact coil having a lower flexibility and a higher rigidity can be connected to the base end portion of the contact coil 20b, but the bonding and fixing structure at this portion is provided between the contact coils 20a and 20b. It can be the same as the joint fixing structure. However, if the bonding portion between the close contact coil 20b and the third close contact coil is not particularly bent, the fixing structure shown in FIG. 5 may be employed.

A connecting ring 21 is used to fix the contact coils 20a and 20b in a connected state. The connecting ring 21 is formed of a thin metal ring. A through hole 22 is formed at a substantially middle position in the axial direction of the circumferential body of the connection ring 21. The through hole 22 is a connecting ring 21
The purpose is to allow the user to visually check from outside whether or not the two coils 20a and 20b are closely bonded together and the bonding position. In the drawing, the winding directions of the close contact coil 20a and the close contact coil 20b are opposite, but this is for clearly distinguishing the two close contact coils. However, the winding directions of the two contact coils 20a and 20b need not necessarily be reversed.

By using the connecting ring 21 having the above-described structure, the contact coils 20a and 20b are welded inside the connecting ring 21 using the laser welding device 23. Must be welded. To this end, first, the contact coil 20
It is necessary to insert a and 20b from both sides of the connection ring 21 and to join them so that the ends of these contact coils 20a and 20b are in close contact with each other. Moreover, it is preferable that the joining position is substantially the middle position in the axial direction of the connecting ring 21, that is, the distance from the joining portion to the end of the connecting ring 21 is substantially the same. The joining state and joining position between the close contact coils 20a and 20b can be visually confirmed through a through hole 22 provided in the connecting ring 21, as is apparent from FIG. Here, in order to accurately join the ends of the contact coils 20a and 20b, the contact coils 20a and
It is preferable that the edge portion of the edge portion 20b is accurately subjected to the edge treatment so that a level difference does not occur. Further, in order to be able to confirm the joining position more accurately, a joining display line 24 may be provided on the outer surface of the connecting ring 21.

After the contact coils 20a and 20b are accurately joined at predetermined positions in the connecting ring 21 as described above, the laser welding device 23 is mounted on the outer side of the connecting ring 21.
Is applied, and the joint between the connection ring 21 and the contact coils 20a and 20b is welded by heating and melting with the heat of the laser. Here, the laser irradiation position may be any position in the circumferential direction as long as it is a position avoiding the through hole 22 in the connection ring 21, but considering the strength of the connection portion and the like, the opening position of the through hole 22 Preferably, it is at the opposite position.

There may be a plurality of laser welds, but sufficient strength is obtained by welding only one location indicated by W in FIG. Here, in the forceps 10 as a treatment tool, the gripping claws 11 are opened and closed by pushing and pulling an operation wire inserted into the flexible shaft 20, but a large force is applied to the flexible shaft 20. When pulling the operation wire. Therefore, the force acting at this time is such that, of the close contact coils 20a and 20b constituting the flexible shaft 20, the close contact coil 20a, which is the highly flexible close contact coil located at the distal end side, is the close contact coil which is the low flexible close contact coil. Since the force is in the direction of pressing the contact coils 20a and 20b, the contact coils 20a and 20b can be separated from each other or any one of the contact coils can There is no inconvenience such as separation. Therefore, a single laser spot welding portion can maintain a sufficient connection strength.

As described above, laser spot welding is performed for W 1
The presence of only the individual portions can suppress the degree of deterioration of the close contact coils 20a and 20b due to the influence of heat. Moreover, even if the portions of the contact coils 20a and 20b where heat acts are slightly deteriorated and become brittle, the strength of the relevant portions does not decrease as a whole because they are covered by the connecting ring 21.

At the joint between the close contact coils 20a and 20b, the portion covered by the connecting ring 21 is a hard portion.
Therefore, unless the length of the connecting ring 21 in the axial direction is made as short as possible, it becomes difficult to pass through the treatment instrument insertion channel C, particularly the portion of the treatment instrument insertion channel C located at the angle I _2. . Connecting ring 2
The length in the axial direction of 1 must not only completely cover the spot welding point W, but also the contact coils 20a,
At the end of 20b, it must also cover a part that has been deteriorated by the influence of heat due to laser irradiation.

Now, in FIG. 2, when it is assumed that the range affected by the heat by welding is the same as that shown in FIG.
In the case of FIG.
It is necessary to set the distance to the ends of the equivalent to L ₁ shown in FIG. Accordingly, the substantial length of the connecting ring 21 in the axial direction is L ₁ + L ₁ = 2L ₁ , but in the connecting ring 8 in FIG. 5, the distance L between the welds W ₁ and W _{2 is} further increased.
_{Since 2} is required, the total length is 2L ₁ + L ₂ , and the connecting ring 21 can be shortened by at least L ₂ from the connecting ring 8. This shortens the rigid portion of the flexible cable 12 and consequently inserts I
And greatly bending the angle portion I ₂ in, even in a state where the treatment instrument insertion channel C is bent largely,
The connecting ring 21 can smoothly pass through this bent portion. Accordingly, the operability of insertion into the treatment instrument insertion channel C is significantly improved.

[0024]

As described above, according to the present invention, a connecting ring is fitted to a joint portion of two closely-connected coils which are connected to each other, and a through hole is formed in a peripheral body of the connecting ring. After confirming the joining condition and joining position of both contact coils, spot welding by laser was performed from the outside of the connection ring, so that the portion of the contact coil that deteriorated due to the heat during welding was covered with the connection ring. Because it can protect effectively, the length of the hard part generated by attaching this connecting ring can be shortened,
This has the effect that the operability of the insertion operation in the treatment tool insertion channel is significantly improved.

[Brief description of the drawings]

FIG. 1 is an overall configuration diagram showing a treatment tool for an endoscope according to an embodiment of the present invention, together with an endoscope.

FIG. 2 is a cross-sectional view of a main part of the treatment tool for an endoscope, showing one embodiment of the present invention.

FIG. 3 is an external view of FIG. 2, which is a view showing a state rotated by 90 ° with respect to FIG. 2;

FIG. 4 is a cross-sectional view showing an overall configuration of a forceps as an example of a treatment tool.

FIG. 5 is a cross-sectional view of a connecting portion of a close contact coil constituting a flexible shaft according to the related art.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 10 Forceps 11 Gripping claw 12 Flexible cable 13 Opening / closing operation part 20 Flexible shaft 20a, 20b
Close contact coil 21 Connecting ring 22 Through hole 23 Laser welding device 24 Joining indication line C Treatment instrument insertion channel I Insertion part

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Shinichi Koshitaka 700, Konakacho, Sano City, Tochigi Pref.

Claims (3)

[Claims] 1. A treatment tool, comprising: a flexible shaft formed of a close-contact coil; and an operating portion provided at a distal end of the flexible shaft, wherein the treatment tool is inserted into a treatment tool insertion channel of an endoscope. The flexible shaft is formed from close-contact coils having different properties so as to have a difference in flexibility in the axial direction thereof, and the endoscope treatment tool in which these close-contact coils are connected to each other by welding means. A connecting ring formed with a through hole for confirming a joint portion in a peripheral body portion is fitted into a joint portion between the two contact coils that are connected to each other. A treatment tool for an endoscope, wherein the treatment tool is a spot welded portion by a laser applied to a joint portion of the endoscope. 2. The treatment tool for an endoscope according to claim 1, wherein the through hole is formed at one position substantially at an intermediate position in the axial direction of the connection ring. 3. The treatment tool for an endoscope according to claim 2, wherein the spot welding portion is provided at a position opposite to a portion where the through hole of the connection ring is formed.