JPS62137581A - Manufacture of time-piece case - Google Patents

Abstract

PURPOSE:To prevent a defective connection in the connecting portion of parts and enable a uniform a color tone to be obtained over the whole surface of a case by forming an inorganic film by a vapor phase plating after a plurality of case constituting parts are welded by a laser beam. CONSTITUTION:Stainless steel constituent parts 1 are welded by the continuous oscillating light beam 3 of a carbonic acid gas laser to be connected together to one case. Then, after washing, the case is set in an ion plating apparatus and, after evacuated, Ti is heated and evaporated by an electron beam to form a discharge plasma whereby an inorganic film 2 of titanium nitride is formed on the set case. Thus, defective connections in the connecting portions of the parts can be prevented and a uniform color tone can be obtained over the whole surface of the case. Further, a cost reduction effect due to the reduction in a vapor plating process is obtained.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a method for manufacturing a watch case on which an inorganic film of titanium nitride, titanium carbonitride, chromium nitride, chromium carbonitride, etc. is formed. .

[Summary of the invention]

In manufacturing a watch case composed of two or more parts, the present invention involves welding two or more metal parts using a laser beam as a heat source, and then applying titanium nitride, titanium carbonitride, titanium nitride, etc. using a vapor phase plating method. By using a process to form an inorganic film of chromium, chromium carbonitride, etc., it is possible to obtain a watch case of low cost and high quality.

[Conventional technology]

Conventionally, the following method has been used to form the same inorganic film of titanium nitride, titanium carbonitride, chromium nitride, chromium carbonitride, etc. on each component of a watch case consisting of two or more parts. It is being

In advance, each component 1 is coated with an inorganic film 2 such as titanium nitride.
is formed by vapor phase plating.

Next, the two or more components are joined together by caulking, biting, brazing, laser welding, etc. to form one watch case.

[Problem that the invention seeks to solve]

However, in the conventional method, the process of forming a lever film by vapor phase plating is performed for each individual component, which increases processing time and increases costs.

Also, quality problems arise, such as the color tone of the inorganic coating differing from part to part.

Furthermore, in brazing or laser welding, defects such as peeling or cracking are likely to occur at the joint.

[Means for solving problems]

In order to solve the above problem, in the present invention, first, each component part 1 is welded using laser light and bonded together as one part, and then a physical vapor deposition method such as ion blasting or sputtering or a thermal reaction method is used. Titanium nitride, titanium nitride,
Inorganic films such as titanium carbonitride, chromium nitride, and chromium carbonitride were formed.

[Effect]

By using the above process, an inorganic film such as titanium nitride is formed on the surface of each component l under the same conditions, so a uniform color tone can be obtained and vapor phase plating can be completed in one step.
It only takes a few degrees, which also reduces processing costs. In addition, since each component is laser welded without any inorganic coating, the optimal welding conditions can be selected and welding defects can be prevented.

Note that if a method other than laser welding, such as caulking, biting, or brazing, is used to join each component 1, the caulked portion may be deformed due to heating of the component in the vapor plating process. This is not preferable because there is a risk of problems such as poor bonding due to a decrease in the strength of the material, and poor adhesion of the inorganic film on the brazed part. In the case of laser welding, not only does it not have the above-mentioned drawbacks in joining, but it can also be applied to waterproof cases by seam welding, and is the most suitable joining method for the present invention.

〔Example〕

The present invention will be explained below based on Examples.

Example 1 Each component l made of stainless steel material was welded at a speed of 1 m/min using continuous oscillation light 3 of a carbon dioxide laser with an output of 350 watts, and joined to one case.

Next, after cleaning this case with an organic solvent, acid, and alkali, it was set in a jig installed in an ion blating device called an active reaction vapor deposition method.
After evacuation to orr, nitrogen partial pressure lXl0-Tor
Titanium was heated and evaporated with an electron beam in an atmosphere of R, and a discharge plasma was formed using the provided ion blating mechanism to form an inorganic film 2 of titanium nitride with a thickness of 1 μm on the set case.

This case was subjected to a 1-meter drop test on concrete five times, but no abnormalities were found in the joints.

Furthermore, the single color tone was uniform over the entire surface of the case, and no abnormality was observed in the adhesion test by bending.

Example 2 Each component 1 made of stainless steel material was welded at a speed of 1 m/min using continuous oscillation light 3 of a carbon dioxide laser with an output of 350 watts, and joined to one case.

Next, in the same manner as in Example 1, this case was cleaned and placed in an ion blating device, and the
Evacuate to a nitrogen partial pressure of 1.5XL0-3Torr,
Titanium is heated and evaporated with an electron beam in an atmosphere with an acetylene partial pressure of 2X10-'Tor, and titanium carbonitride is deposited on the set case while forming discharge plasma using the ion blating mechanism provided. An inorganic film 2 with a thickness of 1 μm was formed.

This case was subjected to the same strength test as in Example 1, but no abnormality was found in the joint.

Furthermore, the color tone was uniform over the entire surface of the case, and no abnormality was observed in the adhesion test by bending.

〔Effect of the invention〕

As mentioned above, by using a manufacturing method in which multiple case components are welded using laser light and then an inorganic film is formed by vapor phase plating, it is possible to prevent bonding defects at the joints of the parts and to cover the entire surface of the case. Uniform color tone can be obtained, and cost reduction effects can also be obtained by reducing the vapor phase plating process.

[Brief explanation of drawings]

FIG. 1 is a longitudinal sectional view of a watch case according to the present invention, and FIG. 2.3.4 is a longitudinal sectional view of a watch case according to a conventional method. 1-------Each component 2---Inorganic coating 3--Laser light 4--Biting section 5--Caulking section 6------Welding section application Person Seiko Electronic Industries Co., Ltd.

Claims (1)

[Claims] A watch case that consists of the process of welding two or more metal parts using laser light as a heat source and then forming an inorganic film of titanium nitride, titanium carbonitride, chromium nitride, chromium carbonitride, etc. using a vapor phase plating method. manufacturing method.