JP7233907B2 - Method for manufacturing tube body - Google Patents

Description

TECHNICAL FIELD The present invention relates to a method for manufacturing a tubular body and a tubular body.

In recent years, it has been studied to change the wire material of the mesh tube, which is a structural member of the insertion portion of the endoscope, to a resin material with high corrosion resistance and chemical resistance. The mesh tube of a conventional endoscope is made of metal, and up to now, the mesh tube has been molded with a resin-made exterior member by extrusion molding. On the other hand, in a resin-made mesh tube, the mesh tube is melted by the heat during extrusion molding. Therefore, when using a resin mesh tube, a method of covering the mesh tube with a tubular exterior member and fixing the end of the mesh tube to the end of the exterior member has been studied.

As a method of covering a tubular exterior member to a mesh tube and fixing them together, for example, Patent Document 1 discloses a method of welding the ends of the mesh tube and the exterior member using high-frequency heating. disclosed.

Japanese Patent Application Laid-Open No. 2002-214540

However, the method disclosed in Patent Document 1 is a method of heating a metal mesh tube by high-frequency heating and welding it to an exterior member, so even if it is applied to a resin mesh tube, the mesh tube does not generate heat. Therefore, it cannot be welded to the exterior member.

The present invention has been made in view of the above, and an object of the present invention is to provide a tube body manufacturing method and a tube body that can fix a resin mesh tube to an exterior member.

In order to solve the above-described problems and achieve the object, a method for manufacturing a tube body according to the present invention provides a method of manufacturing a tubular body by pulling both ends of a resin mesh tube having a first outer diameter and a first inner diameter in the longitudinal direction. By tightening, the first outer diameter and the first inner diameter are reduced, and after inserting the mesh tube in a tensioned state into a resin-made exterior member having an inner diameter close to the first outer diameter. , by releasing the tension state of the mesh tube , an integrated body of the mesh tube and the exterior member is formed, and a core bar having an outer diameter approximate to the first inner diameter is attached to the mesh tube in the integrated body. by inserting it into the inner hole of the integrated body, pressing an ultrasonic horn against the entire circumference of both ends of the integrated body to vibrate the exterior member, melting the exterior member, and A member forms a weld embedded in the mesh tube and cools the weld.

Further, in the method for manufacturing a tube body according to the present invention, in the above invention, the formation of the welded portion includes pressing the ultrasonic horn having a curved pressing surface of 90° or less on both ends of the integrated body. , by vibrating the integrated body while rotating it about its axis.

Further, in the method for manufacturing a tube body according to the present invention, in the above invention, the exterior member is made of a material having a melting point lower than that of the resin forming the mesh tube, and the formation of the welded portion is performed by the exterior member. Ultrasonic welding is performed under the condition that the member is melted and the mesh tube is not melted, and the exterior member is embedded in the mesh tube.

Further, in the method for manufacturing a tube body according to the present invention, in the above invention, after cooling the welded portion, an intermediate position between one end portion and the other end portion of the welded portion is cut.

According to the present invention, the resin mesh tube can be fixed to the exterior member by using ultrasonic welding.

FIG. 1 is a cross-sectional view showing the configuration of a tube body manufactured by a method for manufacturing a tube body according to an embodiment of the present invention. FIG. 2 is a side view for explaining an integrated product forming step of inserting a mesh tube into an exterior member in the method of manufacturing a tube body according to the embodiment of the present invention. FIG. 3 is a side view including a partial cross-section for explaining a metal core insertion step of inserting the metal core into the inner hole of the mesh tube in the manufacturing method of the tube body according to the embodiment of the present invention. FIG. 4 is a side view including a partial cross section for explaining the state after the metal core insertion step in the method of manufacturing the tube body according to the embodiment of the present invention. FIG. 5 is a front view for explaining an ultrasonic welding step in the tube body manufacturing method according to the embodiment of the present invention. FIG. 6 is a side view including a partial cross section for explaining the ultrasonic welding step in the method of manufacturing the tube body according to the embodiment of the present invention. FIG. 7 is a front view for explaining an ultrasonic welding step in the tube body manufacturing method according to the embodiment of the present invention. FIG. 8 is a side view including a partial cross section for explaining the ultrasonic welding step in the method of manufacturing the tube body according to the embodiment of the present invention. FIG. 9 is a cross-sectional view showing the states of the mesh tube and the exterior member before and after the ultrasonic process in the method of manufacturing the tube body according to the embodiment of the present invention. FIG. 10 is a side view including a partial cross section, showing a state after the ultrasonic welding step in the method for manufacturing the tube body according to the embodiment of the present invention. FIG. 11 illustrates a core metal removing step of removing the core metal from the inner hole of the mesh tube and a cutting step of cutting a part of the welded portion in the method of manufacturing the tube body according to the embodiment of the present invention. is a side view including a partial cross section for FIG. 12 is a side view including a partial cross-section for explaining a helical tube inserting step for inserting a helical tube into an inner hole of a mesh tube in the tube body manufacturing method according to the embodiment of the present invention. FIG. 13 is a side view including a partial cross-section for explaining a mouthpiece attaching step of attaching a mouthpiece to a welded portion in the method of manufacturing a tube body according to the embodiment of the present invention. FIG. 14 is a side view including a partial cross section, showing a state after the mouthpiece attaching step in the method for manufacturing the tube body according to the embodiment of the present invention.

Hereinafter, a method for manufacturing a tube body and an embodiment of the tube body according to the present invention will be described with reference to the drawings. In addition, the present invention is not limited to the following embodiments, and the constituent elements in the following embodiments include those that can be easily replaced by those skilled in the art, or those that are substantially the same.

(tube body)
First, the configuration of a tube body manufactured by a method for manufacturing a tube body according to an embodiment of the present invention will be described with reference to FIG. In the figure, a flexible tube 1 for an endoscope is shown as an example of the tube body. The flexible tube 1 includes a mesh tube 11, an exterior member 12, a helical tube 13, and a mouthpiece .

The mesh tube 11 is formed in a cylindrical shape. The mesh tube 11 is formed by weaving strands of thermoplastic resin into a cylindrical shape. Moreover, the outer peripheral side of the mesh tube 11 is covered with an exterior member 12 . As a result, the mesh tube 11 and the exterior member 12 form an integrated body 20. As shown in FIG. A helical tube 13 is inserted into the inner peripheral side of the mesh tube 11 .

The exterior member 12 is formed in a cylindrical shape and is made of a thermoplastic resin. The exterior member 12 is made of a material having a melting point lower than that of the thermoplastic resin forming the mesh tube 11 . A welded portion 11a is formed on the entire periphery of both ends of an integral body 20 composed of the exterior member 12 and the mesh tube 11. As shown in FIG.

The welded portion 11 a is obtained by melting the exterior member 12 by ultrasonic welding and embedding the exterior member 12 in the mesh gaps of the mesh tube 11 . A mouthpiece 14 is inserted and fixed to the outer peripheral side of the welding portion 11a.

(Method for manufacturing tube body)
A method for manufacturing a tube body according to the present embodiment will be described with reference to FIGS. 2 to 14. FIG. The method of manufacturing the tube includes a tensioning step, an integral forming step, a metal core inserting step, an ultrasonic welding step, a cutting step, a helical tube inserting step, and a mouthpiece attaching step in this order.

<Tension process>
In this step, the first outer diameter and the first inner diameter of the reticular tube 11 are reduced by stretching both ends of the reticular tube 11 having the first outer diameter and the first inner diameter in the longitudinal direction.

<Integrated object forming process>
In this step, as shown in FIG. 2, the tensioned mesh tube 11 is inserted into the exterior member 12 having an inner diameter that is close to the first outer diameter, and then the tensioned mesh tube 11 is released. As a result, as shown in the left diagram of FIG. 3, the reticular tube 11 is covered with the exterior member 12, and an integrated body 20 composed of the reticular tube 11 and the exterior member 12 is formed. In addition, the above-mentioned "inner diameter approximate to the first outer diameter" specifically includes an inner diameter that is slightly larger than the first outer diameter in addition to the same inner diameter as the first outer diameter. .

<Mandrel insertion process>
In this step, as shown in FIG. 3, the core bar 15 having an outer diameter close to the first inner diameter is attached to the integrated body 20 while the outer peripheral surface of the mesh tube 11 is brought into close contact with the inner peripheral surface of the exterior member 12. It is inserted into the inner hole of the mesh tube 11 . FIG. 4 shows a state in which the metal core 15 is inserted into the one piece 20. As shown in FIG. The above-mentioned "inner diameter approximate to the first inner diameter" specifically includes an inner diameter that is slightly smaller than the first inner diameter in addition to the same inner diameter as the first inner diameter.

<Ultrasonic welding process>
In this step, the exterior member 12 is melted by pressing the ultrasonic horn 17 against the entire periphery of both ends of the integrated object 20 to vibrate, and the exterior member 12 is formed on the entire periphery of both ends of the integrated object 20. A welded portion 11a embedded in the mesh tube 11 is formed.

In this step, as shown in FIGS. 5 and 6, the integrated object 20 into which the core metal 15 is inserted is placed on the receiving jig 16, and the end of the exterior member 12 of the integrated object 20 is welded by an ultrasonic welding machine ( (illustration omitted) ultrasonic horn 17 is applied. 7 and 8 show a state in which the ultrasonic horn 17 is in contact with the end of the exterior member 12. FIG.

A pressing surface 17 a of the ultrasonic horn 17 has a diameter slightly smaller than the outer diameter of the exterior member 12 . Further, the pressing surface 17a of the ultrasonic horn 17 is formed in a curved surface shape of 90° or less, and is configured to abut in a range of 90° or less with respect to the circumferential direction of the outer peripheral surface of the exterior member 12. there is Further, the pressing surface 17a of the ultrasonic horn 17 is configured to abut against the outer peripheral surface of the exterior member 12 in the axial direction for a predetermined length.

In this step, as shown in FIGS. 7 and 8, the exterior member 12 is vibrated while the ultrasonic horn 17 is in contact with the outer peripheral surface of the exterior member 12 . As a result, due to the ultrasonic vibration from the ultrasonic horn 17, the contact portion between the inner peripheral surface of the exterior member 12 and the wires on the outer peripheral surface of the mesh tube 11 is heated in the range where the ultrasonic horn 17 is applied. . As a result, the inner peripheral surface of the exterior member 12 is melted, and the exterior member 12 is embedded in the mesh tube 11 .

After that, the ultrasonic horn 17 is released, the integrated body 20 including the metal core 15 is rotated by 90° around the axis, the ultrasonic horn 17 is brought into contact with the outer peripheral surface of the exterior member 12, and vibration is again applied. As described above, in this step, ultrasonic welding is repeatedly performed while rotating the integrated object 20 about its axis, thereby forming welded portions 11a on the entire periphery of both ends of the integrated object 20 as shown in FIG. After that, the welded portion 11 a is cooled, and the integral body 20 including the metal core 15 is removed from the receiving jig 16 .

Here, as described above, the exterior member 12 is made of a thermoplastic resin having a melting point lower than that of the thermoplastic resin forming the mesh tube 11 . In this step, ultrasonic welding is performed under the condition that the exterior member 12 is melted but the mesh tube 11 is not melted, and the exterior member 12 is embedded in the mesh tube 11 . The ultrasonic welding conditions under which the exterior member 12 is melted and the mesh tube 11 is not melted are experimentally determined in advance in consideration of the combination of materials of the mesh tube 11 and the exterior member 12 .

<Cutting process>
In this step, as shown in FIG. 11, after the cored bar 15 is pulled out from the one piece 20, a portion of the welded portion 11a is cut. In this step, for example, as indicated by the dashed line in the figure, the welded portion 11a is cut at an intermediate position between one end portion 111 and the other end portion 112 thereof.

<Spiral pipe insertion process>
In this step, as shown in FIG. 12, a helical tube 13 having an inner diameter similar to the first inner diameter is inserted into the inner hole of the reticular tube 11 in the one piece 20 .

<Clasp installation process>
In this step, as shown in FIGS. 13 and 14, the flexible tube 1 is completed by attaching the mouthpiece 14 to the welding portion 11a.

According to the tube body manufacturing method according to the present embodiment as described above, the resin mesh tube 11 can be fixed to the exterior member 12 by using ultrasonic welding. In addition, according to the method of manufacturing the tube body according to the present embodiment, heat is not generated in a portion other than the portion to which the ultrasonic horn 17 abuts. can be welded to

Conventionally, a method of bonding and fixing the ends of the mesh tube and the ends of the exterior member with an adhesive has also been used. However, in such adhesive fixing, it takes a long time for the adhesive to harden, uneven application of the adhesive and variations in the adhesive area occur, and an adhesive layer between the outer peripheral surface of the mesh tube and the inner peripheral surface of the exterior member. There are problems such as an increase in the outer diameter of the end of the completed tube body due to the formation of the .

On the other hand, in the tube body manufacturing method according to the present embodiment, by using ultrasonic welding, the ends of the mesh tube 11 and the ends of the exterior member 12 can be instantly fixed, and the ultrasonic horn Only the site with which 17 is contacted can be locally fixed. In addition, in the method for manufacturing the tube body according to the present embodiment, by using ultrasonic welding, the exterior member 12 is melted and embedded in the mesh tube 11, so that the outer diameter of the end portion of the completed tube body is It doesn't get bigger.

In addition, since flexible tubes and bending tubes for endoscopes to which the tube body according to the present embodiment is applied are generally disposable, they are required to be manufactured at a lower cost. In the method for manufacturing the tube body according to the present embodiment, by using ultrasonic welding, the end portion of the mesh tube 11 and the end portion of the exterior member 12 can be instantly and easily fixed. The manufacturing cost can be greatly reduced compared to the conventional adhesive fixation, etc., which has been done in the work.

As described above, the tube body manufacturing method and the tube body according to the present invention have been specifically described by the mode for carrying out the invention, but the gist of the present invention is not limited to these descriptions. It should be interpreted broadly based on the range statement. Further, it goes without saying that various changes and alterations based on these descriptions are also included in the gist of the present invention.

1 flexible tube (tube body)
REFERENCE SIGNS LIST 11 mesh tube 11a welding part 111 one end 112 other end 12 exterior member 13 helical tube 14 mouthpiece 15 cored bar 16 receiving jig 17 ultrasonic horn 17a pressing surface 20 integral object

Claims (4)

reducing the first outer diameter and the first inner diameter by pulling and tightening both ends of a resin mesh tube having a first outer diameter and a first inner diameter in the longitudinal direction;
After inserting the reticular tube in a tense state into a resin-made exterior member having an inner diameter close to the first outer diameter, the reticular tube and the exterior member are released from the tense state. form a unity,
inserting a cored bar having an outer diameter similar to the first inner diameter into the inner hole of the mesh tube in the integrated body;
By pressing and vibrating the entire periphery of both ends of the integrated body with an ultrasonic horn, the exterior member is melted, and the exterior member is embedded in the mesh tube around the entire periphery of both ends of the integrated body. forming a welded part with
cooling the weld;
A method for manufacturing a tube body. The welded portions are formed by pressing the ultrasonic horn having a pressing surface having a curved surface of 90° or less against both ends of the integrated body, and vibrating the integrated body while rotating it about its axis. to be
The manufacturing method of the tube body according to claim 1. The exterior member is made of a material having a lower melting point than the resin forming the mesh tube,
Formation of the welded portion is carried out by performing ultrasonic welding under conditions in which the exterior member is melted but the mesh tube is not melted, and the exterior member is embedded in the mesh tube.
The method for manufacturing the tube body according to claim 1 or 2. After cooling the welded portion, an intermediate position between one end and the other end of the welded portion is cut;
The method for manufacturing the tube body according to claim 1 or 2.

Images