JPH01258814A - Method and apparatus for manufacturing flexible tube for endoscope - Google Patents

Abstract

PURPOSE:To grade up the quality and performance of a product by inserting a core with a recessed groove which can be structurally easily removed because of shrinkage of the external circumference by extraction of a spacer into an internal diameter part of a flexible tube and press-forming the flexible tube. CONSTITUTION:A round bar forming the recessed groove 41 on the external circumferential surface along an axial direction is divided into two parts centering the recessed groove 41 and a spacer 44 is held on the divided part so that it can be taken in and out freely and one core 41 is formed as a whole. In manufacturing the flexible tube, first, a reticulated tube 13 is attached and fixed to the external circumference of a spiral tube 12, then, a grooved core 40 is inserted, the external part of the reticulated tube 13 is press-formed to provide a recessed groove 11 in the axial direction, then, the spacer 44, core 40 are removed in this sequence. Thus, it is possible to obtain a product having enough strength and flexibility.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a method and apparatus for manufacturing a flexible tube that forms the insertion portion of an endoscope, and in particular, it relates to a method and an apparatus for manufacturing a flexible tube that forms the insertion portion of an endoscope. The present invention relates to a method and apparatus for manufacturing a flexible tube having grooves formed along the length thereof.

[Prior Art] A conventional flexible tube of an endoscope is generally a spiral tube formed to have a uniform diameter over its entire length, and the outer side of the spiral tube is covered with a mesh tube, and the outer side is further covered with a flexible tube made of a synthetic resin material. It was covered with an outer skin, and was formed into an elongated cylinder with a circular cross section.

[Problems to be Solved by the Invention] In a general endoscope, channels are inserted into a flexible tube. However, when it is desired to add a second or third forceps channel, the additional forceps channels must be placed along the outside of the flexible tube, and To prevent infection from occurring, the channel may be disposable after each use. In such cases, the channels are arranged along the outside of the flexible tube (see Japanese Patent Application Laid-Open No. 61-17912
Publication No. 8).

However, the flexible tube of conventional endoscopes had a simple circular external shape, so if the channel was placed along the outside of the flexible tube, the channel would protrude from the flexible tube, impairing insertion into the body cavity. However, it had the disadvantage of causing significant pain to patients.

Therefore, it is also conceivable to form a groove along the tube axis on the outer circumferential surface of the flexible tube, and to house the channel in the groove from the outside. Forming a concave groove along the tube axis in a flexible tube is relatively easy if a spiral tube is not used in the structure of the flexible tube. However, the flexible tube of an endoscope must have both sufficient strength against bending and crushing, and sufficient flexibility to easily bend along the inner wall of the patient's body cavity. It is essential to use To form a concave groove in this helical tube along the tube axis direction, a grooved core metal with a concave groove shape (female type) is inserted into the helical tube, and the helical tube is inserted into the helical tube from the outside. It is sufficient to press-form the core metal along the concave grooves, but in reality, when such a forming process is performed, the core metal sticks tightly to the helical tube due to the twisting of each turn, etc. Therefore, it is not possible to make a flexible tube with grooves formed along the tube axis using a helical tube, and it is not possible to make a flexible tube using a helical tube with sufficient strength and flexibility for practical use. It has not been possible to create a flexible tube that combines these features.

This invention solves such conventional problems, and uses a spiral tube to provide a flexible tube having grooves on the outer circumferential surface along the tube axis direction, so as to have both sufficient strength and flexibility. An object of the present invention is to provide a method and apparatus for manufacturing a flexible tube for an endoscope, which can be formed into a flexible tube.

[Means for Solving the Problems J To achieve the above objects, 1. The method for manufacturing a flexible tube for an endoscope according to the present invention is to divide a round bar having a groove in the axial direction into two parts. It is divided vertically around the groove so that the halves contact each other only at the bottom of the groove, and a spacer is inserted and removed between the divided parts to form a single grooved core bar as a whole. After inserting the grooved core into the inside of a helical tube formed to have a uniform diameter over its entire length, the helical tube is pressed from the outside into the groove of the grooved core to insert the helical tube in the axial direction. A concave groove is press-formed along the groove, and then the spacer is removed from the grooved core metal to form a movement space in the grooved core metal, and the grooved core metal is removed from the helical tube. Features.

The manufacturing equipment used therein divides a round bar with grooves formed along the axial direction vertically around the grooves so that the bipartite parts contact each other only at the bottoms of the grooves.
It is characterized by being made of a grooved core bar formed into one piece by holding a spacer between the divided portions so as to be freely insertable and detachable.

[Operation] By pressing the helical tube from the outside into the groove of the grooved core metal, a groove extending along the axial direction is press-formed in the helical tube. Then, by removing the spacer from the grooved core metal, the two halves of the grooved core metal can be rotated relative to each other around the bottom of the groove, opening the groove of the grooved core metal to rotate the spiral. Clearance can be provided between the pipe and the pipe. Therefore, the grooved core metal can be easily removed from the helical tube in this state.

[Example] Examples will be described with reference to the drawings.

In FIG. 1, numeral 40 indicates an example of a grooved core metal used in the present invention. This grooved core metal 40 is a round bar having a groove 41 formed on its outer circumferential surface along the axial direction, and is vertically divided into two parts with the groove 41 at the center, and a spacer 44 in the shape of an elongated rod, for example, is inserted into the divided part. The core metal is formed as a whole by sandwiching the metal core so that it can be inserted and removed. As shown in FIG. 2, the divided half portions 42a and 42b have divided surface portions 43a and 43b cut out in a tapered shape so that they contact each other only at the bottom 46 of the groove 41. and,
A spacer 44 is provided in the middle of the dividing surface portions 43a and 43b.
Guide grooves 45 are formed to face each other over the entire length along the axial direction.

The spacer 44 can be inserted into and removed from the guide groove 45. When the spacer 44 is removed from the guide groove 45, as shown in FIG. 46, and the tapered divided surfaces 43a and 43b are brought into contact with each other,
Conversely, the mouth of the groove 41 can be slightly opened.

Returning to FIG. 1, both halves 42a of the round bar are shown.

At both ends of the ring 42b, only the portion surrounding the guide groove 45 is formed to have a small diameter, and the ring 4 surrounds the small diameter portions 47a and 47b.
8 is fitted. This ring 48 is a grooved core metal 40
To prevent the metal from disassembling along the dividing part, the grooved core bar 4
It serves to temporarily hold 0 at both ends. In FIG. 1, illustration of the ring on one end side is omitted.

To manufacture a flexible tube, first, as shown in FIG. 4, a mesh tube 13 is closely fixed to the outside of the spiral tube 12. During this work, a temporary core metal 49 in the shape of a round bar is placed inside the spiral tube 12.
Insert it.

The helical tube 12 is made by winding a metal strip having a uniform width and thin thickness into a spiral shape with a uniform diameter over its entire length. As the material, for example, stainless steel or phosphor bronze, which has high strength and toughness, can be used, and a precipitation hardening alloy material such as beryllium copper can also be used. Stainless steel wire or the like can be used as the material for the mesh tube 13, but if a precipitation hardening alloy material is used for the spiral tube 12, it is more preferable to use the same alloy material for the mesh tube 13. .

Next, the spiral tube 12 and the mesh tube 13 are fixed at both ends by soldering 53, and then the soldered portion 53 is cut to remove irregular portions on the outside thereof. Then, the temporary core bar 49 is removed, and a grooved core bar 40 is inserted in its place, as shown in FIG. This grooved core metal 40 serves as a press die (female die) for press-molding concave grooves on the outer circumferential surface of the tube material consisting of the spiral tube 12 and the reticular tube 13 in the next step.

Next, the spiral tube 12 and the mesh tube 13 are integrated into a grooved core bar 4.
0 to form a groove along the axial direction. Figure 6 shows an example of the press process.
A tube material consisting of a spiral tube 12 and a mesh tube 13 is sandwiched between a pair of forming rolls 56.57, and the forming rolls 56.5
Rotate 7. The outer peripheral surfaces of the forming rolls 58 and 57 are formed in the shape of the outer surface of the reticular tube 13, as shown in FIG. A protrusion 58 is provided protruding around the entire circumference in accordance with the shape. Then, this protrusion 58 becomes a male die of a press die, and a groove flb is formed in the outer peripheral surface of the tube material made up of the spiral tube 12 and the mesh tube 13 along the tube axis direction.

Note that the above press forming may be performed by a general suppressing type press working, as shown in FIG. 8.
is a male protrusion.

After the press forming of the groove 11b is completed, the spacer 44 is removed from the grooved core bar 40. Then, both divided halves 42a and 42b of the grooved core metal are rotated about the contact portion of the groove bottom 46. Then, as shown in FIG. 9, the groove 41 of the grooved core bar opens slightly, and the spiral tube 12
A clearance 50 is generated between the two. As a result, next, the grooved core bar 40 can be easily removed from the inside of the helical tube 12.

When a precipitation hardening type alloy material is used for the spiral tube 12, the spiral tube 12 is subjected to solution treatment. The formed temporary core bar (not shown) is attached to the grooved core bar 40.
When beryllium copper is used as the zero alloy material to be inserted after being extracted, the solution treatment is performed by heating at 810° C. or higher for 10 minutes or more and then rapidly cooling.

By performing solution treatment in this way.

Processing distortion when forming the concave groove 11b by press is removed,
Twisting of the spiral tube 12 is prevented.

After that, it is best to perform age hardening treatment by heating at around 315°C for 2 hours or more. Precipitation hardening alloys such as beryllium copper can be finally hardened by age hardening treatment. By using a relatively soft material, the concave groove portion 11b can be easily processed. Note that various conditions such as the temperature and time of the heat treatment vary depending on the composition and dimensions of the material.

Finally, the outer surface of the reticular tube 13 is coated with an outer skin 14. This outer skin 14 is made of, for example, a synthetic resin such as a polyurethane resin. The outer skin 14 is formed by applying molten resin to the outer surface of the reticular tube 13 by extrusion molding or the like. Alternatively, an outer skin previously formed into a tube shape may be tightly attached to the outer surface of the reticular tube 13 by heat processing, vacuum suction, etc. FIG. A cross-section of the tube IO is shown.

A base (not shown) is attached to both ends of the flexible tube 10 thus formed by soldering or the like, and the flexible tube 10 is assembled into an endoscope as shown in FIG. 11.

In FIG. 11, reference numeral 2 denotes a distal end main body containing an objective lens (not shown), etc., and 3 a curved portion that can be bent freely by remote control. Reference numeral 4 denotes an operating section in which various operating devices are built-in, and on its side wall.

A bending operation knob 5 for remotely controlling the bending of the bending portion 3 is rotatably provided. IO is a flexible tube manufactured by the manufacturing method of the present invention, and connects the operating section 4 and the bending section 3. Reference numeral 11 denotes a groove formed in the outer circumferential surface of the flexible tube 10 in a 0-shape along the tube axis direction, and grooves 21 and 31 continuous to the groove 11 form the tip body 2 and the curved groove. It is also formed in part 3.

In the above embodiment, a single helical tube was used, but as shown in FIG. 12, a plurality of helical tubes 12a and 12b having different winding directions may be closely stacked and used. By doing so, the strength of the flexible tube against twisting is improved.

In the above embodiment, the groove formed in a 0-shape was described, but it can also be applied to a groove formed in a square groove or a rectangular groove, and the spacer 44 is formed in an elongated rod shape. The present invention is not limited thereto, and the spacer may have any shape as long as it can be inserted and removed between the two divided halves 42a and 42b of the grooved core bar 40. I don't mind.

[Effects of the Invention] According to the method for manufacturing a flexible tube for an endoscope of the present invention, after press-forming a concave groove in a helical tube, the grooved core can be easily removed from the helical tube. A flexible tube having a concave groove formed on its outer peripheral surface along the axial direction can be easily manufactured using a spiral tube. Therefore, it is possible to obtain a flexible tube having grooves and sufficient strength and flexibility to withstand practical use.

[Brief explanation of the drawing]

FIG. 1 is a perspective view of a grooved core metal used for manufacturing the flexible tube of the endoscope of the present invention, FIG. 2 is a sectional view of the grooved core metal, and FIG.
The figure is a cross-sectional view of the grooved core metal with the spacer removed, FIGS. 4 to 9 are perspective views showing the manufacturing process of an embodiment of the present invention, and FIG. FIG. 11 is a cross-sectional view of the flexible tube, FIG. 11 is a perspective view of an endoscope incorporating the flexible tube, and FIG. 12 is a perspective view of a plurality of helical tubes with different winding directions stacked one on top of the other. lO... Flexible tube, 11... Concave groove % llb... Concave groove, 12... Spiral tube, 13... Reticular tube, 14...
Outer skin, 40...grooved core metal, 41...concave groove, 42a,
42b... Both divided halves, 43a, 43b... Divided surface portion, 44... Spacer, 45... Guide groove. Agent Patent Attorney Kazuhiko MitsuiFigure 4Figure 5Figure 6Figure 7Figure 11

Claims (3)

[Claims] (1) A round bar with a groove formed along the axial direction is divided vertically around the groove so that both halves of the bar contact each other only at the bottom of the groove, and a spacer is inserted in the divided part. are held in a removable manner to form a single grooved core metal, and the grooved core metal is inserted into the inside of a helical tube formed to have a uniform diameter over the entire length, and then the helical tube is inserted outward. Press the spacer into the groove of the grooved core metal to press-form a groove along the tube axis direction in the helical tube. Next, after removing the spacer from the grooved core metal, remove the grooved core from the spiral tube. A method for manufacturing a flexible tube for an endoscope, characterized in that gold is removed. (2) A round bar with a groove formed along the axial direction is divided vertically around the groove so that both halves of the bar contact each other only at the bottom of the groove, and a spacer is inserted in the divided part. 1. A manufacturing device for a flexible tube for an endoscope, characterized in that the flexible tube is made of a grooved core metal that is formed as a single piece by holding the core metal so that it can be inserted and removed. (3) The apparatus for manufacturing a flexible tube for an endoscope according to claim 2, wherein the spacer is an elongated rod.