JPS586952A - Parts for watch - Google Patents

Abstract

PURPOSE:To provide inexpensive parts of a wrist watch consisting of Al, Ni, Si, Zn and Cu in a restricted composition and having high machinability and superior strength. CONSTITUTION:A Cu alloy consisting of, by weight, 2.0-4.0% Al, 2.0-8.0% Ni, 0.5-1.5% Si, 6.0-15.0% Zn and the balance Cu with inevitable impurities has very low elongation such as about 3% and improved machinability and prevents the discharge of fine shavings during cutting. The strength is about 150kg/mm.<2> as bending strength, and it exceeds >= about 100kg/mm.<2> necessary for the pinion of a gear. When the Al, Ni and Si contents are below the lower limits of said ranges, sufficient strength is not obtd., and when the contents exceed the upper limits, the material is made brittle, causes cracking during drawing, and is difficult to manufacture. Below the lower limit of Zn deteriorates the machinability, and above the upper limit of Zn reduces the strength.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to parts for watches such as wristwatches (hereinafter mainly referred to as parts for wristwatches), and provides inexpensive parts for wristwatches. More specifically, it is a wristwatch component made of a precipitation hardening steel alloy that has good machinability and is functionally satisfactory, and it is possible to reduce costs by streamlining processing.

Traditionally, watch parts, especially gears, have a high pinion. However, free-cutting steel with hard cement tact causes the tool bit to wear out quickly during automatic locking processing, and the tool tool has to be replaced frequently. is the current situation.

Furthermore, since the cutting resistance is high, there is a limit to the improvement in cycle time, making it difficult to reduce costs.

Brass, free-cutting brass, etc. have excellent machinability, but in terms of material functionality, that is, strength, they cannot be used as gears for wristwatch parts. The reason is that the required strength of kana is
This is because a bending strength of about 100 S/- is required, whereas brass has a bending strength of about 80 S/-.

In addition, there are copper alloys containing free-cutting components such as B@-Ou and IJ bronze steel, but although they are satisfactory in strength, their machinability is slightly better than free-cutting steel due to small burrs.

Therefore, the present inventor investigated metal materials that have good machinability and excellent strength, and describes the claims of the present patent. ,2
．． If it is less than 0%, it is inferior in strength as a wristwatch kana, and 4.
This is because if it is 0% or more, it is difficult to manufacture the material. In other words, this is because the material becomes brittle and cracks occur during wire drawing. Ni and 81 are also used for the same reason as At, and are set to 2.0 to 8.0% and tO to 4.0%, respectively. Regarding the amount of Zn added, if it is less than 6.0%, the machinability will deteriorate, and if it is more than 15.0%, the strength will be weakened and the material will become brittle, so it was set at 40 to 15.0%.

Note that, of course, if a free-cutting component such as a ship is included, the machinability will be further improved.

The material having the above composition has a very small elongation of 3%, which eliminates small burrs during cutting, resulting in good machinability. It also has excellent strength, with a bending strength of about 150 f-p/-.

The present invention will be described in detail below based on examples.

Example A copper alloy having the composition of the present invention shown in Table 1 was melted using a high-frequency melting furnace, a hot extruder, and a wire drawing machine.
A 0- bar material was produced.

The steel alloy of the present invention was cut into a pinion for a wrist watch part using an automatic lathe.

The cutting conditions are as follows.

Cutting machine: Automatic lathe Cutting curve: With tool: Carbide (K-01) Number of rotations: 6800 r, p, m Feed: α008 error/r・machine cycle time = 28 seconds The results are shown in Table 2. α8%C-α20% for reference
Pb free-cutting steel and 60%Ou-2.0%pb-remaining Zn
Table 2 also shows the results of the free-cutting yellow surface.

Table 1 Chemical composition (weight ratio) Table 2 Cutting test results As shown in Table 2, the machinability is very good. In addition, B e −
Qu had an average bite life of 15 hours, and PB human phosphor bronze had a bite life of 20 hours.

Next, we conducted an integration test using the kana wristwatch we had created. Naturally, the above-mentioned free-cutting steel was quenched back. The hardness is Hu650. Moreover, the steel alloy of the present invention is heated at 300°C
Hu350 obtained by H hardening effect treatment was incorporated into the test.

As a result, the free-cut brass clock stopped running after two hours of operation. The cause of this was the bending of the kana. However, both the parts made of the present invention and the parts made of free-cutting steel operated normally during a 10-year durability test.

As shown in the examples above, the wristwatch parts of the present invention have excellent machinability and fully satisfy the functions of the parts, and can provide the world with inexpensive wristwatches due to reduced cutting costs. .

In the embodiment, only the pinion was described, but the invention is not limited to pinion parts and can be used in a wide variety of watch parts.

that's all Applicant: Suwa Seikosha Co., Ltd. Agent Patent Attorney Mogami

Claims (1)

[Claims] Both have a weight ratio of At2. O~4.0%, Ni2,0
~a 0%, Si0.5~15%, Zn & 0~
15.0-2 Watch parts consisting of the balance O and inevitable impurities.