JPH08285151A - Forming method of spiral pipe - Google Patents

Abstract

PURPOSE: To thin a metallic belt piece, and make a surface easily slidable by forming a spiral body by arranging the metallic belt piece at prescribed pitch intervals, polishing this spiral body, inserting its polishing part into an outside diameter regulating member, and regulating an outside diameter so as to become the same outside diameter with an unpolished work part. CONSTITUTION: A metallic belt piece 31 such as stainless steel having specific width and thickness is used for a rod-shaped winding jig 30, and is wound in a condition of leaving prescribed pitch intervals, and a spiral body is formed. A tip part of this spiral body is soaked in a electrolytic bath, and electrolytic polishing is performed. Its polishing part is inserted into an outside diameter regulating member, and an outside diameter D1 of an inside spiral body 32a is regulated so as to become the same outside diameter with an unpolished work part as well as to become slightly larger than an inside diameter D2 of an outside spiral body 32b. Therefore, the metallic belt piece 31 is thinned after being wound in a spiral shape, and since its surface becomes easily slidable, an inserting member can be protected.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for forming a spiral tube forming a tubular structure in a flexible tube used as a flexible tube section or a light guide flexible section in an insertion section of an endoscope. Is.

[0002]

2. Description of the Related Art An endoscope widely used for medical purposes, industrial purposes, etc. generally has a main body at the base end portion of an insertion portion 1 which is inserted into a body cavity, a mechanical device or the like as shown in FIG. The operation section 2 is provided in series, and the main body operation section 2 is generally provided with a light guide flexible section 3 which is detachably connected to a light source device (not shown). The insertion portion 1 is a flexible tube portion 1a for most of the length from the continuous portion to the main body operation portion 2, the flexible tube portion 1a has an angle portion 1b, and the angle portion 1b has a tip portion. The main body 1c is sequentially connected. Further, the light guide flexible portion 3 has substantially the same structure as the flexible tube portion 1a of the insertion portion 1.

Of the three parts constituting the insertion part 1, the flexible tube part 1a secures a length such that the distal end part main body 1c can reach a predetermined observation target part, and the main body operation part 2 is operated by an operator. The object is to be separated from the patient or the like to the extent that it does not hinder gripping and operation, and is quite long. The flexible tube portion 1a needs to have flexibility over substantially the entire length thereof, and in particular, a portion to be inserted inside a body cavity or the like must have a structure having more flexibility. Here, the flexibility required for the flexible tube portion 1a is
It is flexible in the bending direction, and must have sufficient strength in the expansion / contraction direction and the crushing direction.

Further, the flexible tube portion 1a is required to have a certain degree of rigidity on the side of the connecting portion of the flexible tube portion 1a to the main body operating portion 2 in order to give a pushing thrust when it is inserted into a body cavity or the like. On the other hand, it is preferable that the portion of the side of the angle portion 1b that is connected to the angle portion 1b be more flexible so that when the angle portion 1b bends, the portion follows the bending to some extent. That is, it is advantageous to change the degree of flexibility of the flexible tube portion 1a in the axial direction from the viewpoint of insertion operability, reduction of patient's pain, and the like.

The flexible tube portion 1a is formed by inserting a light guide, an image guide (a signal cable in the case of an electronic endoscope), a treatment instrument insertion channel, an air / water supply pipe, etc. into the flexible tube. The flexible tube is usually constructed as shown in FIG. That is, in the figure, 10 is a flexible tube, and the flexible tube 10 includes inner and outer spiral tubes 11a,
The tubular net body 12 and the outer skin layer 13 are sequentially laminated on 11b. The spiral tubes 11a and 11b constitute a structure of the flexible tube 10, and are metal strips made of stainless steel or the like that are spirally wound at a predetermined pitch. Further, the tubular net body 12 is formed by eccentrically arranging metal wire rods according to a predetermined number of holding and striking numbers. The skin layer 13 is formed by molding means or the like.

Therefore, in order to change the degree of flexibility of the flexible tube 10 in the axial direction, the spiral tube 11a,
This can be achieved by changing the pitch interval of 11b, changing the thickness, or partially performing surface treatment such as plating. The flexibility can also be changed by making the mesh of the cylindrical net body 12 coarse and dense or by changing the amount of the adhesive applied to it.

[0007]

Various techniques have been proposed, including those described above, for changing the flexibility. Among these, the thickness of the spiral tube should be changed. It is advantageous to maintain stable characteristics over a long period of time. However, in the conventional technique, the metal strip is wound into a spiral shape after being subjected to processing such as roll pressing and grinding. Here, the spiral winding is performed by winding a metal strip on the jig using a rod-shaped jig. For this reason, the formed spiral tube has a uniform inner diameter in the axial direction, and the outer diameter becomes smaller than other portions by the amount of thinning the metal strip.

When it is used as the flexible tube portion in the insertion portion, as described above, various insertion members are inserted inside and the insertion portion is constituted.
Since there is a strong demand for reducing the diameter, the filling rate in the flexible tube portion is considerably high. Since the tip end side of the flexible tube portion, that is, the vicinity of the continuous portion to the angle portion, bends following the bending operation of the angle portion to some extent, it is the most bendable portion of the entire flexible tube portion. is there. However, although the bent metal strip is thinned, there is a problem that this portion cannot be used for increasing the internal space of the flexible tube according to the conventional technique. Further, when the tubular net body is formed on the spiral tube to form the outer skin layer, the thickness of the outer skin layer changes in the axial direction, and the outer skin layer is formed by the molding means. However, there is a problem that the accurate processing becomes difficult.

The present invention has been made in view of the above points, and an object thereof is the same as a portion which is not thinned by spirally winding a metal strip and then thinning it. It is to be able to manufacture a spiral tube having an outer diameter.

[0010]

In order to achieve the above-mentioned object, the present invention provides a spiral body forming step of spirally winding metal strips at a predetermined pitch interval, and the spiral body,
An electropolishing step in which a portion in the axial direction is immersed in an electrolytic bath for electrolytic polishing, and an outer diameter is adjusted so that the polished portion of the spiral tube is inserted into an outer diameter regulating member to have the same outer diameter as the non-polished portion It is characterized in that it comprises an outer diameter regulating step for regulating.

[0011]

First, a spiral is obtained by spirally winding a metal strip. The spiral body has a shape which is used as a structure as it is when the flexible tube is formed. Next, in the axial direction of the spiral body, electrolytic polishing is performed by immersing a portion having more flexibility in the electrolytic bath. Generally, electrolytic polishing is a chemical polishing method performed to smooth the surface of a metal. This is applied to reduce the thickness of the metal strip, and is performed in the form of a spiral body wound in a spiral shape, not in a flat plate state.

By electrolytic polishing, the spiral body is made thinner by the amount of the surface polished, and at the same time, the pipe diameter of the thinned portion is increased. In addition, when electrolytic polishing is performed, the surface is naturally mirror-finished and the edges are rounded. In electrolytic polishing, the polishing amount changes depending on the position of the electrode connected to the spiral tube, and the thickness also changes by changing the immersion time in the electrolytic bath in the axial direction. Therefore, the hardness is gradually changed from the distal end side of the spiral tube on the basis of either one of these elements, or preferably both elements.

After the electrolytic polishing treatment, there is a difference in pipe diameter between the polished portion and the other non-polished portion. Therefore, in the outer diameter regulating step, the outer diameter is regulated so that the pipe diameter portion enlarged by electrolytic polishing has the same outer diameter as the non-machined portion. According to this outer diameter regulation, first, the outer diameter is reduced by inserting it into a jig or the like. Then, in order to be able to maintain the reduced diameter state, a tubular mesh body is inserted in advance in the jig, or
In the case of forming a heavy helix, it can be achieved by binding them by means such as welding.

The spiral tube is formed as described above, whereby the thinned portion becomes more flexible than the other portions, and the inner diameter of this portion is enlarged. When configured as a flexible tube,
The internal space is widened, and there is a margin in the members inserted inside. Further, the surface is made slippery by electropolishing and there is no edge, so that the internal insertion member can be protected.

[0015]

Embodiments of the present invention will be described below with reference to the drawings. Regarding the basic structure of the flexible tube, there is no particular difference from that shown in FIG. That is, as shown in FIG. 3, the flexible tube 20 includes inner and outer spiral tubes 21a and 2a.
The tubular net body 22 is laminated on the structure made of 1b, and the outer shell layer 23 is formed by a molding means or the like in a state where the tubular net body 22 is coated with an adhesive. . Here, the double spiral tube 21 including the inner and outer spiral tubes 21a and 21b is formed by the following steps.

First, the inner and outer spiral tubes 21a, 21
In forming b, as shown in FIG. 4, a rod-shaped winding jig 30 is used, and the winding jig 30 is provided with a metal strip such as stainless steel having a certain width and thickness. The piece 31 is used, and the piece 31 is wound at a predetermined pitch. Here, since the inner spiral tube 21a needs to be formed so as to have a smaller diameter than the outer spiral tube 21b, a winding jig that forms the inner spiral tube 21a and a winding jig that forms the outer spiral tube 21b. Use a jig with a different outer diameter.
Then, these two winding jigs are adapted to the shapes when they are finally formed as the inner and outer spiral tubes 21a and 21b.

As described above, the inner spiral body 32a and the outer spiral body 32b are formed as shown in FIG. 5, but the outer diameter D ₁ of the inner spiral body 32a is slightly larger than the inner diameter D ₂ of the outer spiral body 32b. To do. As a result, when the inner spiral body 32a is inserted into the outer spiral body 32b, both spiral bodies 32a and 32b come into close contact with each other.

Next, electrolytic polishing is performed on the spiral bodies 32a and 32b (hereinafter, reference numeral 32 is used when these spiral bodies are collectively referred to). For this purpose, the electrolytic cell 40 shown in FIG. 6 is used. The electrolytic solution is stored in the electrolytic bath 40. When the spiral body 32 is made of stainless steel, a mixed solution of hydrochloric acid and nitric acid or the like is used as the electrolytic solution. In addition, a stirring device 41 for stirring the electrolytic solution is inserted in the electrolytic bath 40. And
The negative electrode 42 is inserted in the electrolytic solution, and the spiral body 3
2 is used as a + electrode, and a power source 43 is connected between them to energize. Here, the + electrode 43 is the electrolytic cell 40 of the spiral tube 32.
The spiral tube 3 is connected to the tip of the part to be dipped in and is used as a flexible tube part in the insertion part.
The length of the portion of the No. 2 immersed in the electrolytic bath 40 is about several tens cm, for example, about 20 to 30 cm.

-When a current is passed between the electrode 42 and the spiral 32, the spiral 32 is electropolished to smooth the surface and reduce its thickness. In addition, the edge portion of the spiral body 32 is further polished and becomes rounded. Along with this, the diameter of the portion of the spiral body 32 that has been wound so as to have a predetermined diameter is immersed in the electrolytic cell 40, and the diameter of the portion increases. Here, since the + electrode is connected to the tip portion of the spiral body 32, the spiral tube 32 is polished most at the tip end side, and the polishing amount is continuously reduced toward the base end side. Then, by gradually pulling up the spiral body 32 from the electrolytic cell 40, the dipping time in the electrolytic solution is continuously reduced from the distal end side to the proximal end side, thereby further increasing the polishing amount. You can As a result, as shown in FIG.
The electrolytically polished tip portion has a thin wall and a smooth surface. The edge has a rounded shape, and the diameter of the tube expands into a trumpet shape as it goes toward the tip side.

The spiral body 32 thus obtained, that is, the inner spiral bodies 32a and 32b has a large diameter at the tip end portions thereof. 21a, outer spiral tube 2
A double spiral tube 21 made of 1b is formed. Here, in order to regulate the outer diameter, the cylindrical regulation jig 5 shown in FIG. 8 is used.
0 is used. The regulation jig 50 has a pair of regulation pieces 50a, 50a.
It is longer than the length of the portion where the electrolytic polishing was performed.
The restriction pieces 50a, 50a are connected by a hinge 51 so as to be openable and closable. In addition, the restriction piece 50a is provided with a plurality of openings 52 in the axial direction.

First, the restriction piece 50 of the restriction jig 50.
a and 50a are joined so as to be closed, and the outer spiral 32
By pulling b while twisting, it is deformed so that its outer diameter is smaller than the inner diameter of the regulation member 50, and is inserted into the regulation jig 50. As a result, the portion where the tube diameter is enlarged by electrolytic polishing is regulated by the regulation jig 50. Similarly, by inserting the inner spiral body 32a inside the outer spiral body 32b, the outer diameter of the portion of the inner spiral body 32a where the pipe diameter is enlarged by electrolytic polishing is restricted. Then, in this state, both spiral bodies 32a, 32b
The overlapping portion of the opening 5 from the outside of the regulation jig 50.
The double spiral tube 21 is formed by performing spot welding at a plurality of points on the joint portion using the laser welding machine 53 through the welding machine 2.

In the double spiral tube 21 formed in this way,
The regulating jig 50 is taken out by opening, the cylindrical net body 22 is eccentrically assembled on the regulating jig 50, and an adhesive is applied to the cylindrical net body 22, and then the outer skin layer 23 made of a soft resin is formed by a molding means. The flexible tube 20 is formed by forming the.

The flexible tube 20 formed as described above is
It can be configured as a flexible tube portion in the insertion portion. On the distal end side of the flexible tube 20, the thickness of the double spiral tube 21 is reduced, and the surface is smoothed so that the slidability is good with respect to each other. You can In particular, since the wall thickness changes continuously, the tip part is the most flexible and becomes harder toward the base end side. The flexible tube portion has advantageous characteristics because it has flexibility in the vicinity of the connecting portion to and is hardened continuously toward the base end side. In addition, since the outer diameter of the portion thinned by electrolytic polishing is matched with the outer diameter of the other portion that has not been polished, the inner diameter of the flexible tube 20 increases. When configured as a flexible tube portion, the internal space is widened, it is possible to allow a variety of members to be inserted into the flexible tube portion, the insertion member inserted in the flexible tube portion, Since the filling rate is reduced at the tip end portion where the angle portion considerably bends next to the angle portion, these insertion members are protected. Further, smoothing by electrolytic polishing improves the slidability, and the spiral tubes 21a and 21b have no edges, so that the slidability is maintained even if the insertion members slide in contact with each other. Also, it is very advantageous in terms of protecting the insertion member as well.

Although in the above-described embodiment, electrolytic polishing is performed on both of the double spiral tubes, electrolytic polishing may be performed on only one of the inner and outer spirals. Further, the spiral tube may be composed of a single spiral body instead of the double spiral tube. In this case, in order to control the outer diameter of the spiral body expanded by electrolytic polishing, the cylindrical net body is inserted in advance in the restriction jig 50, and the spiral body is inserted inside the cylindrical net body. Good. Further, at the time of electrolytic polishing, the polishing amount is controlled by the electrode connection position to the spiral 32 and the immersion time in the electrolytic solution, but it is not always necessary to use both in combination. Furthermore, although the portion to be electropolished is the tip portion of the spiral tube, any portion of the spiral tube can be electropolished by appropriately immersing the portion in the electrolytic solution. For example, when a flexible tube is used as the light guide soft part, it is preferable that both ends are hard and the middle part is more flexible. For this purpose, the middle part of the spiral tube is used as an electrolyte. It may be soaked.

[0025]

As described above, the method of the present invention is
A spiral forming step of spirally winding the metal strip at a predetermined pitch interval, an electrolytic polishing step of electrolytically polishing this spiral by partially immersing a part in the axial direction in an electrolytic bath, and a spiral tube It consists of an outer diameter regulation process that inserts the polished portion into the outer diameter regulation member and regulates the outer diameter so that it has the same outer diameter as the non-polished portion. And the surface becomes slippery, so the electrolytically polished portion becomes more flexible than other portions, and the thinned portion has the same outer diameter as the other portion, and the inner diameter is Since it expands, when it is configured as a flexible tube, the internal space becomes wider, a margin is created for the members to be inserted inside, and the edges of the spiral tube are eliminated, so it is possible to protect these insertion members. Has the effect of being able to .

[Brief description of drawings]

FIG. 1 is an external view showing a configuration of an endoscope.

FIG. 2 is a structural explanatory view of a flexible tube according to a conventional technique.

FIG. 3 is an enlarged sectional view of an essential part of a flexible tube manufactured according to the present invention.

FIG. 4 is an explanatory diagram showing a spiral body forming step.

FIG. 5 is a cross-sectional view of the inner and outer spirals formed by the spiral forming step.

FIG. 6 is an explanatory diagram showing an electrolytic polishing step.

FIG. 7 is a cross-sectional view of a spiral body formed by electrolytic polishing.

FIG. 8 is an explanatory diagram showing an outer shape regulation process.

[Explanation of symbols]

 20 flexible tube 21 double spiral tube 21a inner spiral tube 21b outer spiral tube 22 cylindrical net body 23 outer skin layer 30 winding jig 31 metal strip 32, 32a, 32b spiral body 40 electrolytic cell 42-electrode 50 for regulation Jig 53 Laser welder

Claims (5)

[Claims] 1. A spiral forming step of spirally winding metal strips at a predetermined pitch interval, and an electrolytic polishing step of electrolytically polishing the spiral by partially immersing a part of the spiral in an electrolytic bath. And an outer diameter regulating step of regulating the outer diameter so that the polished portion of the spiral tube is inserted into the outer diameter regulating member so as to have the same outer diameter as the non-polished portion. . 2. The outer diameter regulating step, while inserting the spiral body into the outer diameter regulating member, inserts another spiral body inside or outside the spiral body and spot-welds the spiral tube to the other spiral body. The method for forming a spiral tube according to claim 1, wherein the spiral tube is formed. 3. The method for forming a spiral tube according to claim 2, wherein the other spiral body is also electropolished. 4. The outer diameter regulating step, wherein the spiral body is inserted inside the mesh body while the tubular mesh body is inserted in the outer diameter regulation member. Method for forming spiral tube. 5. The method of forming a spiral tube according to claim 1, wherein, in the electrolytic polishing step, a dipping time of the spiral body in an electrolytic bath is changed in an axial direction thereof.