JPH05257090A - Spectacle frame composed of joined parts of nickel-titanium shape memory alloy and its production - Google Patents

Abstract

PURPOSE:To attain high bonding strength and to prevent the deformation of the body of joined parts by melt-bonding joining chips of a metal to the faces of parts of a shape memory alloy to be joined and carrying out brazing or melt bonding through the chips as protrusions. CONSTITUTION:The objective frame of spectacles are composed of an Ni-Ti shape memory alloy and an Ni-Cr alloy joined to each other and have such bonding strength that the constituent parts are not separated even when the frames are bent or twisted. For example, in the case where rims are joined to a bridge 2, joining chips 7, 7 are melt-bonded beforehand to the face of the bridge 2 to be joined. The chips 7 are made of an Ni-Cr alloy and melt- bonded by spot welding or projection welding. This projection welding is carried out by supplying impulse current under pressure and ensures further enhanced bonding strength in a welding atmosphere of an inert gas such as Ar.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an eyeglass frame constructed by joining parts made of nickel-titanium type shape memory alloy and parts made of eyeglass frame material such as nickel-chromium alloy, and a manufacturing method thereof. Is.

[0002]

2. Description of the Related Art In recent years, nickel-titanium type shape memory alloys have attracted attention as a material for eyeglass frames. Since this material is lightweight, has high spring properties, and has excellent corrosion resistance, it has ideal characteristics as an eyeglass frame material. It is being considered for use in parts that do not have. As is well known, nickel-titanium type shape memory alloys and superelastic alloys have poor metallic bondability. Therefore, conventionally, the surface of nickel-titanium type shape memory alloy parts is plated with a metal that is easily brazed A method of brazing and fixing via layers is adopted. Also known is a structure in which a locking tube is provided like "eyeglasses" according to Japanese Utility Model Publication No. 3-26493, other parts connected to the locking tube are fitted, and then the locking tube is pressed and fixed from the outside. Has been. It is also possible to fix with screws or rivets.

By the way, in the former plating method, since the bonding strength of the bonding member depends on the adhesive force of the plating layer, the bonding member may peel off together with the plating layer by the action of an external force. In the latter case, if a locking tube is provided or a screw is used, the number of manufacturing steps of the spectacle frame increases, and at the same time the appearance is impaired, which is not suitable as a spectacle frame that requires fashionability.

Therefore, what was developed as a technique for solving the above-mentioned problems is "Metal frame eyeglasses including nickel-titanium engaging metal parts and a method for manufacturing the same" according to Japanese Patent Laid-Open No. 3-264915. This is because by rapidly raising the temperature of the joining target portion to near the melting temperature of nickel, and pressing the joining target portion in the heat-heated and flexible state at high pressure,
This is a method of metallurgically joining and joining the joints of both alloys with a forged structure. As described above, the nickel-titanium alloy can be firmly joined as a metallic forging structure by momentary temperature rise / pressurization, but as the above-mentioned temperature raising means, a large current is passed, and the current does not flow. If it is not possible to specify the joint portion that heats up and if pressure is applied, the shape of the component body of the spectacle frame may collapse. In addition, since the bonding site is not constant, the bonding strength may be reduced depending on the case, and there is a problem in stabilizing the quality.

[0005]

As described above, the joining of parts made of nickel-titanium type shape memory alloy has the above problems. Problems to be solved by the present invention are these problems, the temperature rising region to be joined is determined,
(EN) Provided are a spectacle frame in which a large joining force is obtained and the shape of a joined component body is not deformed, and a manufacturing method thereof.

[0006]

A spectacle frame of the present invention uses a nickel-titanium alloy as a shape memory alloy, and the alloy is used for other parts except a rim for holding a lens and a hinge for connecting a temple. Conventional spectacle materials such as nickel-chromium alloy, titanium, nickel silver, stainless steel, and cobalt alloy are used as the material of the rim. Therefore, when joining nickel-titanium-based shape memory alloys and nickel-chromium-based alloys, etc., part of the surface of the rim made of nickel-chromium-based alloys is made convex, and a large current is passed through the convexes to raise the temperature. -It is sufficient to pressurize, but it is practically difficult to form a partially convex rim surface. Of course, even if a convex portion is formed on a bridge made of nickel-titanium type shape memory alloy, it cannot be welded.

Therefore, in the present invention, a small joining piece of nickel-chromium alloy or the like is made, and the joining piece is welded to the nickel-titanium side in advance by welding, and the nickel-titanium-based shape memory having the joining piece. The alloy parts are again welded or brazed to parts of nickel-chromium alloy or the like. That is, this is a technique for joining parts of both metals with a joining piece such as nickel / chrome interposed. The size of the above-mentioned joining piece is determined according to the required joining force. Hereinafter, embodiments according to the present invention will be described in detail with reference to the drawings.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows a general spectacle frame, 1 is a rim, 2 is a bridge, 3 is an armor, 4 is a temple, 5 is a hinge, and 6 is a nose pad. Here, a nickel-titanium type shape memory alloy having superelasticity is used as a material for the bridge 2, the endowment 3 and the vine 4, and the hinge 5 for connecting the rim 1 and the vine 4 for holding the lens in an openable and closable manner is nickel.・ Chromium alloy is used. Therefore, in this spectacle frame, the bridge 2 will not be broken even if the left and right rims 1 and 1 are largely bent or twisted, and also the temple 4 will be restored to the original shape by bending.

As described above, the spectacle frame of the present invention is formed by joining the nickel-titanium type shape memory alloy and the nickel-chromium type alloy to each other, and even if the spectacle frame is bent or twisted. It has a joint strength that prevents the parts from separating. For example, when joining the rim 1 and the bridge 2, the joining pieces 7 are welded to the joining surface of the bridge 2 as shown in FIG. The joining piece 7 is made of nickel-chromium alloy and is welded by spot welding or projection welding. Projection welding is a welding method in which an impact current is applied and pressure is applied, and when welding is performed in an inert gas atmosphere such as argon gas, the joining strength is further improved.

As described above, the joining pieces 7, 7 are welded to the joining surface of the bridge 2 in advance, so that the bridge 2 is joined to the rim 1. Since the joining piece 7 is a nickel-chromium alloy, it is made of the same material as the rim 1 and can be welded or brazed. As described above, it is theoretically possible to form a small convex portion on the joint surface of the rim 1 without using the joint piece 7 and apply an impact current to the convex portion for welding, but it is theoretically possible. It is almost impossible to form the convex portion on the plastic working. The joining piece 7 is welded to the bridge 2 as a substitute for the convex portion of the rim 1.

FIG. 3 shows the rim 1 with the joining piece 7 interposed therebetween.
2 shows a cross section in a state where the bridge 2 and the bridge 2 are joined.
Similarly, the hinge 5, which is made of a nickel-chromium alloy, is joined to the end piece 3 and the temple 4 as described above. That is, the nickel-chromium alloy joint piece is welded to the joint surface of the armor 3 or the temple 4, and the hinge 5 is brazed or welded through the joint piece. Of course, here is nickel
Although the case where the parts using the titanium-based shape memory alloy are the bridge 2, the armor 3 and the temple 4 has been described, the present invention is not limited thereto, and in the present invention, the parts composed of the nickel-titanium-based shape memory alloy and nickel-chromium. This is an eyeglass frame in which at least one joint portion of parts made of a system alloy or the like exists. Then, the joining is made by welding a joining piece such as a nickel-chromium alloy to a nickel-titanium-based shape memory alloy component, and brazing or welding to the nickel-chromium-based alloy component through the joining piece. The following effects can be obtained.

[0012]

The spectacle frame of the present invention is constructed by joining parts made of a nickel-titanium type shape memory alloy and parts made of a nickel-chromium type alloy. In joining the two alloys, a joining piece of nickel / chromium-based alloy or the like is welded to a nickel / titanium-based shape memory alloy part in advance, and is brazed to the nickel / chromium-based alloy part or the like through the joining piece. Alternatively, since they are welded, the joining force is high, and even if the spectacle frame is largely deformed, the respective parts do not come off.

In addition, since the portion that melts during welding is the joining piece and not the component body of the spectacle frame, the frame component is not deformed or scratched by the action of the pressing force. Also, without using a joining piece,
The productivity is high and the work is simplified as compared with the case where the convex portion is formed on the joint surface of the component. The joint strength can be adjusted by selecting the size of the joint piece, and it can be applied to eyeglass frames of any design.

[Brief description of drawings]

FIG. 1 is a specific example of a spectacle frame.

FIG. 2 shows a state in which a joining piece is welded to the joining surface of the bridge.

FIG. 3 is a cross section in which the rim and the bridge are joined via a joining piece.

[Explanation of sign]

 1 Rim 2 Bridge 3 Yoroi 4 Crane 5 Hinge 6 Nose pad 7 Joint piece

Claims (2)

[Claims] 1. An eyeglass frame comprising a nickel-titanium shape memory alloy component and another metal component joined together,
The above-mentioned nickel / titanium-based shape memory alloy is joined to the above-mentioned metal component by welding the above-mentioned metal joining piece to form a convex portion on the joining surface, and then brazing or welding through the joining piece. A spectacle frame made by joining parts made of nickel-titanium type shape memory alloy. 2. A method of manufacturing an eyeglass frame comprising joining a nickel / titanium type shape memory alloy part and another metal part, by welding a joining piece of the metal to the joining surface of the nickel / titanium type shape memory alloy part. A method for manufacturing an eyeglass frame, which comprises welding and joining the joining pieces to the metal parts by brazing or welding.