JPH0679347A - Production of superelastic alloy tube - Google Patents

Abstract

PURPOSE:To easily produce the tube consisting of a superelastic alloy having the resilience like the resilience of plastics and strength of metal by forming a deposited layer consisting of the superelastic alloy on the outer periphery of a core body, then removing the core body. CONSTITUTION:The tube 3 consisting of the superelastic alloy is produced by forming the deposited layer 2 consisting of the superelastic alloy on the outer periphery of the core body 1 by a vacuum vapor deposition method, etc., to <=1mm layer thickness, then dissolving away the core body 1 by a liquid chemical, etc. The core body 1 is formed of materials which can be dissolved away by liquid chemicals, such as potassium hydroxide soln., hydrogen fluoride soln. and water, polymers and the like which can be dissolved away by solns., and materials which can be melted at the temp. lower than the m.p. of the formed superelastic alloy layer. As a result, the tube which has a large bending angle, is substantially free from the permanent set in bending, is stiff and has excellent strength is obtd.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of manufacturing a superelastic alloy tube suitable for forming a swinging mechanism of an endoscope.

[0002]

2. Description of the Related Art Conventionally, as a swinging mechanism for facilitating entry into an endoscope or the like inserted in a bent thin tube such as a blood vessel, there is one that imitates a joint movement (Japanese Patent Publication No. 63-63).
JP-A-62213), a stainless steel tube or a coil tube is provided at the distal end portion of the endoscope, and a simple structure in which the tube is bent in a desired direction through a pulling operation of an operation wire is easy to manufacture. However, there is a problem in that the one using the stainless tube has a small bending angle and is likely to have a bending tendency, and the one using the coil tube has a weak stiffness and poor strength and the coil portion is easily collapsed.

[0003]

DISCLOSURE OF THE INVENTION The present invention has a supple and strong property such as plastic, which can easily form a swinging mechanism having a large bending angle, a hard bending tendency and a strong waist and excellent strength. The challenge is to get a tube that is comparable to metal.

[0004]

SUMMARY OF THE INVENTION The present invention provides a method for producing a superelastic alloy tube, which comprises forming a deposited layer of a superelastic alloy on the outer periphery of a core body and then removing the core body. To do.

[0005]

By the above-mentioned method, a tube made of a superelastic alloy having flexibility such as plastic and strength as a metal can be easily formed in an arbitrary shape advantageous for a swing mechanism and the like, and the bending angle is large and the bending tendency is small. It is possible to obtain a tube that is hard to stick and has high rigidity and is excellent in strength.

[0006]

The present invention is to manufacture a tube made of a superelastic alloy by forming a deposited layer made of a superelastic alloy on the outer circumference of the core and then removing the core. Figure 1 (A),
The manufacturing process is illustrated in FIG. Reference numeral 1 is a core body, 2 is a deposited layer made of a superelastic alloy, and 3 is a superelastic alloy tube.

As the core body, any removable body can be used. Examples thereof include those that can be dissolved and removed with a chemical solution such as potassium hydroxide solution or hydrogen fluoride solution, water such as silicon, silicon dioxide, sodium chloride, those that can be dissolved and removed with a solvent such as polymer, or the formed superelastic alloy layer. Examples thereof include those that can be melted at a lower temperature, and those that can be removed by an appropriate means while preserving the superelastic alloy layer.

The diameter and shape of the core body are arbitrary. For example, a circle, a polygon, a cross, a star, a radial shape based on the cross section, or a straight shape or a bellows based on the outer edge in the length direction. Shapes such as a shape, a trumpet shape, a drum shape, a barrel shape, and a composite different diameter shape are included. In the present invention, since a tube having an inner diameter and an outer edge shape corresponding to the diameter and outer edge shape of the core body can be formed, a tube having a diameter or outer edge shape which can be advantageously used for the purpose of use based on the diameter or the outer edge shape of the core body is used. It can be easily formed.

The core body can be formed into a tube shape or the like that is advantageous for its removal, or can be provided with an appropriate functional layer such as a conductive layer, a reinforcing layer, or a heat-resistant layer on the surface thereof. The layer does not necessarily have to be removable with the core, but may remain on the inner wall of the superelastic alloy tube.

As the superelastic alloy, for example, Ni.Ti alloy, Cu.Zn.Al alloy, Fe.Ni.Cr alloy or the like may be used as appropriate according to the purpose of use.

The deposition layer of the superelastic alloy on the outer periphery of the core body can be formed by an appropriate method such as a vacuum vapor deposition method, a sputtering method, an ion plating method, a plating method or a combination thereof. The thickness of the deposited layer to be formed can be appropriately determined according to the purpose of use, and is generally 1 mm or less, preferably 80 to 200 μm.

The superelastic alloy tube is obtained by forming a superelastic alloy deposited layer on the outer periphery of the core body as described above.
As shown in (B), it can be obtained by removing the core body by an appropriate method. The physical properties of the deposited layer of the superelastic alloy after removal of the core body can be adjusted by heat treatment or the like, if necessary. The superelastic alloy tube of the present invention can be used for various purposes such as a working channel, in addition to forming a swinging mechanism of an endoscope.

Example 1 Argon atmosphere pressure 0.5 to 10 Pa, high frequency power 200
˜500 W, target; Ni / Ti (50/50) alloy, while rotating the rod of 0.8 mm diameter made of silicon by the high frequency magnetron sputtering method under the conditions of the distance between the target and the film forming surface is 200 mm and the time is 30 minutes. After forming a Ni / Ti alloy layer having a thickness of 20 μm on the outer periphery (FIG. 1A), it is immersed in an etchant composed of a potassium hydroxide solution for 24 hours to dissolve and remove the silicon rod (FIG. 1B). A 30 mm Ni / Ti-based superelastic alloy tube was obtained.

As shown in FIG. 2, the Ni / Ti-based superelastic alloy tube 3 is attached to the tip of the image guide 5, and operation wires 4 are attached to the outside of the tube 3 at four positions, up, down, left and right, to operate the tube. As a result of examining the properties, it was possible to easily bend at a large bending angle by operating the operating wire, and even after bending 100 times in the same direction, no bending tendency was found. Furthermore, he was strong and had excellent strength.

[0015]

According to the present invention, a tube made of a superelastic alloy having flexibility such as plastic and strength as a metal can be easily obtained in any shape, and the tube can be bent at a large angle. It has the characteristics that it is hard to bend and is strong and has excellent strength.

[Brief description of drawings]

FIG. 1A is an explanatory perspective view of a manufacturing process.

FIG. 1B is a cross-sectional view of another manufacturing process.

FIG. 2 is an explanatory diagram of an application example.

[Explanation of symbols]

 1: Core body 2: Superelastic alloy deposition layer 3: Superelastic alloy tube

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification code Office reference number FI technical display location // C22C 19/03 C

Claims (1)

[Claims] 1. A method for manufacturing a superelastic alloy tube, comprising forming a deposited layer of a superelastic alloy on the outer periphery of a core body, and then removing the core body.