JP2002082316A - Method for manufacturing magnesium spectacle frame - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for manufacturing a spectacle frame, made of Mg or Mg alloy which is superior in all of rigidity, spring characteristic and weatherability (corrosion resistance), and to provide the spectacle frame and spectacles obtained therefrom. SOLUTION: This method for manufacturing magnesium or a magnesium alloy spectacle frame includes a process step of subjecting the entire surface of a spectacle frame blank, obtained by cutting and forming the magnesium or magnesium alloy to the sand blasting treatment by spraying of a blast material in manufacturing the spectacle frame made of the magnesium or the magnesium alloy.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a magnesium spectacle frame having excellent rigidity, spring properties and deflection recovery, and to a magnesium spectacle frame and a magnesium spectacle having good weatherability obtained by this method.

[0002]

2. Description of the Related Art Conventionally, spectacle frames have been made of celluloid, tortoiseshell, brass, acetate, SUS, NWS, Ni alloy, Co alloy, Ti, T
It has been developed according to the times, using i-alloy, NT alloy and the like as a material, and has reached today. And, in recent years, Ti alloy spectacle frames have excellent quality in terms of functionality. On the other hand, Mg or Mg alloy has poor surface treatment technology for both cast and rolled products to date,
In addition, it has poor corrosion resistance and weather resistance, and has been avoided as a material for eyeglasses. For this reason, SUS and Ti alloy materials, which are difficult-to-cut materials, were developed earlier than Mg or Mg alloy, and have reached the present.

However, considering the problem of EU nickel regulation on metal allergy to the skin, which is considered to be caused by Ni and Ni alloy, and the recycling of earth and resources such as Ti and Ti alloy, these metals and alloys are considered. Then, there are various problems, and there are many problems that need to be solved.

On the other hand, Mg and Mg alloy have excellent recyclability. Further, there is no lighter metal in the metal spectacle frame that satisfies Mg. However, commercially available Mg and Mg alloy materials have not obtained the properties enough to satisfy the function of the spectacle frame.

As a method for manufacturing an eyeglass frame using such Mg or Mg alloy material, the following four processing methods are generally employed. (A) A general method of assembling a brazed joint by preparing several types of parts, such as forming a deformed wire, forming a part by plastic working, and forming a part by cutting. (B) Casting cutting and finishing methods. (C) A method of slicing a material made of an extruded material having a sectional shape of a front frame portion of an eyeglass frame and using the sliced material as a front frame. (D) Rolled product cutting (celluloid shaving type) method.

The above method (A) is a general method in the art at present, but a brazing method for Mg or an Mg alloy has not yet been established. In addition, the method (C) is not practical because the cost is high due to diversification of designs and the like. Further, in the above method (B), the grain size of the cast product is coarse in the structure of the material, and the thickness and thickness of the cast product vary depending on the design and shape of the cast product. I haven't. Therefore, heat treatment such as annealing must be performed to promote recrystallization, and quality must be averaged. In addition, this inevitably leads to enlargement of the tissue, and loses the hardness, the tensile strength, and the resiliency essential to glasses. In addition, the design of the spectacle frame inevitably generates at least two cold weld line flow interfaces, which are likely to be broken by some force and lack the safety of the spectacle frame.

In the method (D), the rolled product (extended product) has a relatively small grain size in the material structure with respect to the cast product, and the structure is stretched in the rolling direction. It is well known that the bending strength in the rolling direction is greater in the vertical direction. In addition, it goes without saying that the rolled product is more uniform than the cast product in terms of the uniformity of the structure. Further, Mg or Mg alloy has good machinability, and the processing time for mirror finishing is shortened to a level that is incomparable to other materials. In addition, the sponge resistance, which is a characteristic of Mg or Mg alloy, is high, and scratches and the like are less likely to occur as compared with light metals such as Al and Al alloy. Furthermore, Mg or Mg alloy is expected as a promising light metal that can solve recycling energy, environmental problems, and the like.

However, conventional eyeglass frames made of Mg or a Mg alloy have not yet obtained the required rigidity, spring property, and weather resistance (corrosion resistance). That is, M
Conventional eyeglass frames made of g or Mg alloy have high bubbling properties but low hardness of around HV40. Further, even if the spectacle frame has been subjected to a surface treatment, it has low weather resistance (corrosion resistance), and may cause contact corrosion (electric corrosion) with dissimilar metals. Furthermore, this spectacle frame lacks the requisite springiness and great deflection recovery.

Accordingly, the present invention provides a method of manufacturing a spectacle frame made of Mg or a Mg alloy having excellent rigidity, spring properties, and weather resistance (corrosion resistance), and a spectacle frame and spectacles obtained by the method. The purpose is to:

[0010]

SUMMARY OF THE INVENTION In view of the above-mentioned problems in the conventional method for manufacturing an eyeglass frame, the inventors of the present invention have applied to a cut or formed Mg or Mg alloy eyeglass frame material in all directions (front, back, By applying a specific spraying process from the right and left side surfaces, the left and right lens V groove surfaces, etc., pressure is applied to the particles of the surface layer structure of the spectacle frame in a shocking manner, the crystal structure is densified, and the surface hardness is increased. And that the above object can be achieved.

The present invention has been made on the basis of the above findings, and when manufacturing a spectacle frame made of magnesium or magnesium alloy, the entire surface of the spectacle frame material obtained by cutting and forming magnesium or magnesium alloy,
An object of the present invention is to provide a method for manufacturing a magnesium spectacle frame having excellent strength and weather resistance by including a step of spraying a blast material and performing sand blasting.

[0012] The present invention also provides a spectacle frame obtained by the above-described manufacturing method, wherein the crystal structure of the surface is densified.

Further, the present invention provides spectacles provided with the magnesium spectacle frame.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a method for manufacturing a magnesium spectacle frame of the present invention will be described in detail based on preferred embodiments.

First, a magnesium or magnesium alloy eyeglass frame material is cut and formed as follows. 1: A rolled material (extended material) of magnesium or a magnesium alloy having a required thickness is cut into required dimensions. 2: The lens groove (inner diameter) is cut by an MC processing machine. 3: The left and right lens grooves are fixed with a clamping block that has been manufactured in advance, and processing such as outer shape, chamfering, end milling, and drilling is performed by an MC processing machine. (In the processing of the above 2 and 3, since the cutting chips discharged by the cutting process and the chips cut at a high speed may be ignited thinly, they are washed away with a large amount of special cutting oil, (4) Since the cut work is in a flat state, a lens curve, bridge curve, etc. are added by pressing. 5: Polish the surface of the work with a rough barrel, finish barrel, or the like.

Then, the entire surface of the spectacle frame material cut and formed (specifically, the entire surface such as the front surface, the back surface, the left and right side surfaces, the left and right lens groove surfaces, etc., is not formed). Sandblasting is performed by spraying a blasting material under the pressure described above. This sand blasting process aims at a conventional shot peening effect (hardening by hammering) and densification of crystal grains on the surface.

The formulation in the sand blasting step is not particularly limited, and any of a dry method and a wet method can be adopted. However, the dry method is particularly preferable from the viewpoint of preventing hydrogen explosion and fire.

In the present invention, it is particularly preferable that the pressurization in the sandblasting step is performed by injecting compressed air by a dry method. The injection pressure at this time is 0.1 to 0.9 MPa, particularly 0.2 to 0.4 MPa.
It is preferable that Further, within the above preferable range of the injection pressure, the injection distance from the nozzle is preferably set to 20 to 50 mm, and the injection is preferably performed for an injection time necessary for obtaining the effect of the present invention.

Examples of the blast material used in the sand blasting step include fine powders such as silica sand, alundum, emery, glass beads and the like. Among these blast materials, it is particularly preferable to use glass beads. The reason for this is that the glass beads have a small cutting force and dimensional stability, and have a large peening effect because they are continuously pressed in a spherical shape. In the present invention, a steel blast material is not used. The reason for this is that when fine steel powder stays on the surface of the work, it may cause contact corrosion peculiar to magnesium and magnesium alloys.

The blasting material is not particularly limited in its shape, and may be in an irregular shape, a spherical shape or the like, but a spherical shape is particularly preferable. Further, the central particle diameter (average particle diameter) of particles (preferably glass beads) as a blast material is 30 to 300 μm, particularly 45 to 90 μm.
m is preferred.

After the step of performing the sand blasting process, it is preferable that the surface is polished by a buff or barrel process, and the mirror finish is performed so that the cut amount is 5 to 70 μm, particularly 10 to 30 μm.

It is preferable that a chemical conversion treatment, an anodic oxidation treatment, and / or a coating treatment are further performed after the polishing treatment. Here, the chemical conversion treatment and the anodic oxidation treatment refer to JI
This is a magnesium alloy anticorrosion treatment method described in SH8651-1995. In addition, the coating process is a process that is applied because it must pass fashion resistance in the designed eyeglass frame, weather resistance as a final surface treatment step, artificial sweat test for corrosion resistance, etc. This is a process of dipping, electrodeposition coating or spray coating with a primer coating as a primer and an acrylic resin, an ester resin, an epoxy resin, a urethane resin or the like as a surface coating.

In particular, a chemical conversion treatment can improve weather resistance (corrosion resistance) on the premise of coating finish, and it is particularly preferable to form a chemical conversion coating film having excellent adhesion to paint. In addition, the anodizing treatment may be colored due to the treatment itself, and is not suitable as the final surface treatment of eyeglass frames that desire fashion, but using the base color enables a wider range of variations. I do. In particular, for the magnesium and magnesium alloy materials according to the production method of the present invention, such chemical conversion treatment and anodic oxidation treatment are important as a coating base treatment.

It is also preferable that after the polishing treatment, plating treatment and / or the same coating treatment as described above is carried out by an electroless zinc substitution method. Here, as a plating treatment, as a generally known method, a zinc substitution treatment is performed, and strike copper plating (pH of 9.6 to
10.4 cyanide bath) and a method of etching with a chromic acid-nitric acid solution and performing strike nickel plating in a bath mainly composed of chemical nickel or basic nickel carbonate-hydrofluoric acid-citric acid. ("Metal Fin
ishing Guide Book ”p.227 (1969)).

Further, after these treatments, a non-conductive or non-metallic material such as a plastic washer, a pipe or a plate-like material, a polymer compound, or the like is applied to bond or attach to a dissimilar metal. This is preferable because fitting, joining, and other direct contact can be avoided, and contact corrosion (electrolytic corrosion) is prevented.
It is desirable that the surface treatment for non-conductivity be selectively performed on a portion that may come into contact with a dissimilar metal, specifically, on a lens restraining screw portion, a temple fastening portion, and a pad arm fixing portion. .

The spectacle frame obtained by the method of the present invention has a surface hardness improved by 30 to 50% by sandblasting as compared with before the sandblasting. Specifically, the surface hardness of the spectacle frame is such that the HV is improved to about 90 by peening hardening. Since the eyeglass frame obtained by the method of the present invention has a high surface hardness as described above, the eyeglass frame is excellent in spring property and deflection recovery.

The spectacle frame obtained by the method of the present invention has a high extensibility and its crystal structure is elongated in the rolling direction. According to the method of the present invention, the crystal structure on the surface of the spectacle frame is densified as described above. The depth of the densified crystal structure is preferably about 140 μm.

The crystal structure of the spectacle frame obtained by the method of the present invention is different from the crystal structure of the spectacle frame that has not been subjected to the sandblast treatment, and is densified (FIG. 1).
And FIG. 2). FIG. 1 is a cross-sectional micrograph of the crystal structure of the magnesium spectacle frame obtained by the method of the present invention, and FIG. 2 is a cross-sectional micrograph of the crystal structure of the magnesium spectacle frame not subjected to sandblasting.

The spectacle frame of the present invention is made of magnesium or a magnesium alloy. Here, as a magnesium alloy, together with magnesium, aluminum, zinc, manganese, silicon, iron, copper, zirconium,
Rare earth (yttrium, scandium, etc.), thorium,
Alloys composed of calcium, nickel, lithium, silver and the like can be mentioned. Particularly, when a magnesium alloy is used in the present invention, 1.0 to 9.5 parts by weight of aluminum, 0.2 to 6.5 parts by weight of zinc, and 1 part of manganese are added to 100 parts by weight of magnesium. 2 parts by weight or more, silicon or iron 0.3 parts by weight or less, copper 0.1 parts by weight or less, zirconium, rare earth, thorium or calcium 0.04 parts by weight or less, nickel 0.03 parts by weight or less Preferably, it is used. Further, other metals or impurities may be contained in an amount of 0.30 part by weight or less based on 100 parts by weight of magnesium.

The spectacle frame of the present invention includes a rim (a substantially C-shaped or a substantially O-shaped one) for holding a lens, a bridge for connecting left and right rims, a rim lock for closing the rim after holding the lens, and a It consists of a temple for hanging, a hinge connecting the rim and the temple, a blow and the like. Further, both the front having one piece of the hinge and the temple having the other piece of the hinge are connected by hinge screws. Further, the spectacle frame of the present invention may be of a type in which a bridge and a temple are directly attached to a lens without providing a rim. In the eyeglass frame of the present invention, each of the above components is made of magnesium or a magnesium alloy.

Further, the spectacles of the present invention include the above-mentioned magnesium spectacle frame. And the spectacles of the present invention, in addition to including the lens, parts required at a predetermined position, for example, a nose pad at a predetermined position of a rim or a bridge,
At the rear end of the temple, a plastic front cell or the like which is to be in contact with the ear is attached. FIG. 3 shows an example of the glasses of the present invention. The eyeglasses shown in FIG. 3 include a rim 1 made of a magnesium alloy in which a bridge and two substantially O-shaped frames are integrated, and screws 6, a resin pipe 7, a nylon washer 8, and a resin nut 9 on both right and left ends of the rim 1. A temple 2 made of a magnesium alloy connected by
A modern (front cell) 3 attached to the rear ends of the left and right temples 2, a resin pad arm 4 attached to a predetermined position of the rim 1, a pad 5 attached to the tip of the pad arm 4, and a rim 1 (Omitted in FIG. 3). The glasses of the present invention having such a configuration are lightweight and have excellent rigidity, spring property, and weather resistance (corrosion resistance).

[0032]

The present invention will be described more specifically below with reference to examples and comparative examples. (Example 1) A magnesium alloy (Mg
-3Al-1Zn alloy)
Sandblasting was performed by spraying glass beads having a center particle diameter (average particle diameter) of 45 to 90 μm as a blast material from all directions using compressed air by a dry method. The injection pressure at this time is 0.3 MPa, the injection time is 15 seconds, and the injection distance from the nozzle is 20 to 50 mm.
Went as. Thereafter, the surface was polished with a rough barrel, a finished barrel, and a finished buff to perform mirror finishing.

The hardness of the magnesium spectacle frame thus obtained (measurement load: 500 g, pressurization time: 10 seconds), the hardness of the unfinished mirror-finished portion (uncompressed portion) is HV45.3, and the sandblast treatment The hardness of the part was HV 91.6, and the hardness HV of the mirror-finished part after sandblasting was 67.7, and the respective measured values were observed. In particular, 49% in the mirror finish after sandblasting
There was an increase in hardness. In addition, a hardness measurement value of 100 to 150% was obtained in the same part when the measurement load was 100 g. From this, it was found that only the surface had high hardness. It is also depicted in a surface micrograph (see the photograph in FIG. 1 (hardened layer, about 140 μm)).

(Comparative Example) An eyeglass frame was obtained in the same manner as in Example 1 except that the sandblasting was not performed. This magnesium spectacle frame has an HV of 45.
It had a surface hardness of 3.

The magnesium spectacle frames obtained in Example 1 and Comparative Example were used, and lenses and other necessary components were attached thereto to form spectacles shown in FIG. After examining the rigidity of these glasses, the manufacturing method of the first embodiment including the step of performing sandblasting (the present invention)
The glasses (magnesium spectacle frames) obtained by
Since the frame has high hardness as described above, the rigidity was superior to the glasses (magnesium glasses frame) obtained by the manufacturing method of the comparative example which did not include the step of performing the sand blast treatment. Further, when both glasses were touched by hand, the glasses (magnesium spectacle frame) obtained by the manufacturing method of Example 1 were glasses (magnesium spectacles) obtained by the manufacturing method of the comparative example which did not include the step of performing sandblasting. Compared to eyeglass frames, it was found to be extensible and excellent in spring properties.

[0036]

According to the method for manufacturing a spectacle frame of the present invention, a magnesium spectacle frame which is lightweight and has excellent rigidity, spring properties and weather resistance (corrosion resistance) and spectacles provided with the frame can be obtained. Can be.

[Brief description of the drawings]

FIG. 1 is a view showing a cross-sectional micrograph of a crystal structure in a magnesium spectacle frame obtained by a production method of the present invention.

FIG. 2 is a diagram showing a cross-sectional micrograph of the crystal structure of a magnesium spectacle frame that has not been subjected to sandblasting.

FIG. 3 is a perspective view showing an example of eyeglasses provided with a magnesium eyeglass frame obtained by the manufacturing method of the present invention, omitting lenses.

 ────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Masao Yao 15-22 Sugimotocho, Sabae City, Fukui Prefecture Sun Reeve Co., Ltd. F-term (reference) 2H006 AA01 AA04

Claims (9)

[Claims] 1. A method for manufacturing a magnesium or magnesium alloy spectacle frame, comprising the steps of spraying a blast material onto the entire surface of a spectacle frame material obtained by cutting and forming magnesium or a magnesium alloy to perform a sandblast treatment. A method for manufacturing an eyeglass frame. 2. The method according to claim 1, wherein the blasting material is quartz sand, alundum, emery or glass beads. 3. The method according to claim 1, wherein the blast material has a center particle diameter (average particle diameter) of 30 to 300 μm. 4. After passing through the step of performing the sand blast treatment, the surface is polished so that the cut amount is 5 to 70 μm.
The method for producing a magnesium spectacle frame according to any one of claims 1 to 3, wherein mirror finishing is performed so as to be as follows. 5. The method for manufacturing a magnesium spectacle frame according to claim 4, wherein a chemical conversion treatment, an anodic oxidation treatment, and / or a coating treatment are performed after the polishing treatment. 6. The method for manufacturing a magnesium spectacle frame according to claim 4, wherein after the polishing processing, plating and / or painting is performed by an electroless method of a zinc substitution method. 7. The method for manufacturing a magnesium spectacle frame according to claim 1, further comprising performing a surface treatment for deconduction. 8. A spectacle frame obtained by the manufacturing method according to claim 1, wherein the crystal structure of the surface is densified. 9. An eyeglass comprising the magnesium eyeglass frame according to claim 7.