JPS6010289B2 - Manufacturing method for metal eyeglass frames - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for manufacturing metal eyeglass frames, and more specifically, a metal eyeglass frame suitable for use with relatively large diameter and thick lenses such as prescription sunglasses. This relates to the manufacturing method.

In the past, most sunglasses were simply made of colored glass without prescription lenses, but in recent years the demand for sunglasses with prescription lenses has increased rapidly.

By the way, sunglasses are characterized by having a larger lens area (hereinafter referred to as "lens diameter") compared to ordinary office glasses for the purpose of protecting the eyes from ultraviolet rays and the fashionability required of sunglasses. As a result, the circumference of the rim becomes longer and the volume of metal used for the frame becomes larger. Especially when using concave lenses for myopia in sunglasses, as the diameter of a concave lens increases, the area around the lens becomes thicker, so it is necessary to cover the thickness around the lens and attach the lens to the rim. As a result, the width of the rim becomes thicker. For the above reasons, when concave lenses for myopia are used in sunglasses, the volume of metal required to manufacture the eyeglass frames increases, making the sunglasses unavoidably heavier. This gives the wearer a feeling of restraint, and is a major drawback since sunglasses are often used under relatively strenuous conditions. In order to avoid such a weight ratio of sunglasses, it is sufficient to form the glasses frames with metals with low specific gravity.However, the metals traditionally used for glasses frames (Table 1) include the following: There was a drawback.

Table 1, that is, among the metal materials shown in Table 1, materials other than AI alloys are excellent in brazing properties, workability, plating properties, and strength.

However, all of these metal materials have a high specific gravity (see Table 2), and therefore, when used in prescription sunglasses such as those mentioned above, the weight becomes large and they are unsuitable for use as eyeglass frames for sunglasses. Table 2 On the other hand, forming eyeglass frames for sunglasses using AI alloys with low specific gravity has been put into practical use.

However, as is well known, N alloy cannot be brazed, so its use is limited to eyeglass frames with designs that do not require brazing. In addition, since brazing cannot be performed as described above, it is necessary to integrally form the rim of the eyeglass frame and the hinge. However, since the temples of eyeglass frames are also made of N alloy, the engagement part between the hinge and the temple is A]
The disadvantage is that the alloys come into direct contact with each other, and the hinge does not move smoothly. Furthermore, AI alloys have low corrosion resistance to human sweat and mechanical strength, and in addition, their optics do not feel expensive, so they are not suitable as frame materials for sunglasses. The present invention was made in view of the drawbacks of the conventional eyeglass frames, and an object of the present invention is to provide a method for manufacturing metal eyeglass frames that are lightweight and have sufficient mechanical strength and corrosion resistance.

According to this invention, T is used as a metal material for eyeglass frames.
Ti or Ti alloys are used.

Ti has excellent corrosion resistance against human sweat and mechanical strength, and as shown in Table 2, it has a low specific gravity of 4.5, making it suitable as a material for lightweight eyeglass frames that require a high degree of mobility. .

Furthermore, ``Ti has excellent workability as a metal and can be colored, so it is suitable for eyeglass frames for sunglasses that require a high level of fashion.However, Ti has poor brazing and plating properties, especially brazing properties. It has not been put to practical use as a material for eyeglass frames because of its inferior properties.According to the present invention, first, Ti alone or a Ti alloy is coated with a metal that can be brazed with Ag or Au so as to be surrounded by it. A wire rod is formed.

Next, each part of the eyeglass frame, such as the rim and temples, is manufactured using the wire rod manufactured by cladding this wire rod, and these parts are appropriately brazed at least in some places to form the eyeglass frame. Thereafter, only the metal that can be deposited and brazed is removed by appropriate means such as etching, thereby manufacturing a metal eyeglass frame in which Ti alone or a Ti alloy is exposed on the surface. The present invention will be explained in more detail below with reference to embodiments shown in the accompanying drawings.

First, a cylindrical Ti alloy containing 90% or more of Ti is coated with a Cu alloy or an Ag alloy, and a wire material for eyeglass frames is clad by a known method to produce the strand 10.

In addition, when cladding a Cu alloy around a Ti alloy, N is added between the Ti alloy 1 and the Cu alloy 7 as shown in Figure 1B.
i (or Ni alloy) layer 5 is interposed. This is to prevent the formation of intermetallic compounds (branches) between Cu alloy 7 and Ti alloy 1 due to heating. Examples of the cladding method include an explosive pressure drop method, a hot pressure acid method, and a hot isostatic extrusion method.

Among these, an example will be shown in which the strand 10 is formed from a wire by cladding and reducing the diameter of an Ag alloy around a Ti alloy by hot isostatic extrusion. Firstly, the diameter is 50
Sail ◇ × 100 cylindrical pure Tj (for example, JIS day
4650) is covered with an Ag alloy (e.g. 5% A-25% Cu) with an outer diameter of 51.25, an inner diameter of 50, and a length of 100. It is extruded by hydrostatic extrusion at a temperature of 600°C to form a composite wire with a diameter of 1 inch. '. } The above compound line is age net (600
Diameter 2.6 by repeating wire drawing with o○) and machining
Form the strands of the sides. In the above manner, Figure 1 A or B
A strand 10 having a configuration as shown in is formed.

Since the surface of this Qin wire 10 is made of Ag alloy 3 or Cu alloy 7, this strand 10' has excellent brazing properties. Using the wire 10 having such excellent brazing properties, each part of the eyeglass frame (temple 11, rim 13, bridge 15, hinge 17, ring string 19) shown in FIG. Form. Next, these parts are joined by brazing.

As described above, since the surface of the wire 10 is formed of the Ag alloy 3 or the Cu alloy 7, each of these parts has excellent brazing properties. The parts to be brazed are:
There are one piece of the hinge 17 and the temple 11, the other piece of the hinge 17 and the rim 13, the rim 13 and the bridge 15, the rim 13 and the ringst 19, and so on. After these parts are brazed together, the temple 11 and the rim 13 are engaged with each other by the hinge 17, thereby forming a prototype of the eyeglass frame as shown in FIG. 2. Next, the original shape of the glasses frame manufactured by the above process is etched with acid, thereby removing the Ag alloy or Cu alloy formed around the Ti or Ti alloy and the N.
Remove j.

This etching solution may be, for example, a 50% solution of ferric nitrate. As a result, the surface of the eyeglass frame is formed with Ti alone or a Ti alloy exposed, and the Ag alloy or Cu alloy remains only on the brazed portion of the eyeglass frame, so that the brazed state is maintained as is. In addition, the composition of the Ag alloy that is pressure-welded to the surface of the Ti alloy should preferably contain 34% or more of Ag in order to ensure the above-mentioned brazing properties, and furthermore, to prevent the Ti alloy and the Ag alloy from alloying with each other. Therefore, it is desirable that Cu content be 35% or less.

Note that it is optional to add other metals as long as the above Ag content and Cu content are satisfied. In addition, as the Cu alloy 7 to be pressure-welded to the surface of the Ti alloy, nickel silver or cupro-Ni can be used.
etc., and the composition of these Cu alloys needs to have a Cu content of 55% or more in order to ensure brazeability and workability.

Table 3 below shows experimental results regarding the weight, brazing strength, and corrosion resistance of metal eyeglass frames manufactured by the method of the present invention described above. Table 3 On the other hand, the experimental results of a closing frame using nickel silver, which has existed in the past, are shown in Table 4 below.

Table 4 The composition of the artificial sweat used in the experiment is as follows, and it was soaked for 5 days.

Sodium chloride 9.8 pm / urination
1.7 ta' evening full course
0.2 t'lactic acid
0.8cc sodium sulfide
0.8 ta'quammonia water
As is clear from the above experimental results, the method of the present invention is extremely lightweight and has no inferior strength compared to conventional eyeglass frames, and also has excellent corrosion resistance against sweat. It becomes possible to provide extremely excellent eyeglass frames.

[Brief explanation of the drawing]

FIGS. 1A and 1B are cross-sectional views showing an example of wires used in the present invention, and FIG. 2 is a perspective view showing an example of a metal eyeglass frame. 1...Pure Ti or Ti alloy, 3...Ag alloy, 5...Ni layer, 7...Cu alloy, 10
...Bare wire tll...Temple, 13...
Rim, 15... Bridge, 17... Hinge, 19
・・・・・・Ring strike. Figure 1 Figure 2

Claims (1)

[Claims] 1. A wire made by coating a metal material that can be brazed on the surface of a metal material mainly composed of Ti is subjected to plastic processing to reduce the diameter to make a wire, and each part of an eyeglass frame is made using the wire,
A method for manufacturing metal eyeglass frames, which comprises removing brazable metal after brazing at least a portion of each of these parts.