JP2000135105A - Production of band for wristwatch - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable the secure coupling of barrels and connecting pins of a band for wristwatches. SOLUTION: A band body 1 is integrally assembled by press fitting drive pins 4 of the diameter slightly larger than the bore of through-holes 2a of the barrels 2 molded by stainless steel or titanium into these through-holes 2a. The band body 1 is then heated to at least the recrystallization temperature region of the stainless steel or titanium and is then held for about 3 minutes at the temperature in the case of the stainless steel or is held for about 45 minutes at the temperature in the case of the titanium. The barrels 2 and the drive pins 4 are thus securely coupled by diffusion joining.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a wristwatch band in which pieces are connected to each other by connecting pins.

[0002]

2. Description of the Related Art To form a flexible wristwatch band by connecting pieces together, usually, a driving pin or a knurled pin is used as a connecting pin for connecting the pieces, and the outer diameter of these press-fit portions is adjusted. By making the diameter slightly larger than the inner diameter of the hole formed in the outer piece, the two are closely fitted.

[0003] However, when a driving pin is used as a connecting pin, the driving pin may be displaced within the range of a difference in tolerance between the outer diameter of the press-fit portion and the inner diameter of the hole caused by the combination. However, although the rate of occurrence is low, the driving pin may fall out of the outer piece in long-term carrying.

On the other hand, when a knurled pin is used as a connecting pin, the knurled pin must be formed of a metal having high hardness in order to prevent buckling deformation at the time of driving. It is difficult to secure the permissible setting tolerance of the difference between the outer diameter of the knurled part and the inner diameter of the hole because the outer diameter of the knurled part is more varied than the tolerance due to the rolling process. As a result, the knurling pin is pulled out from the outer piece by a large amount depending on the pulling force of the outer piece.

[0005]

SUMMARY OF THE INVENTION The present invention has been made in view of such a problem.
It is an object of the present invention to provide a new wristwatch band manufacturing method that enables a firm connection between an outer piece and a connecting pin regardless of the combination of components.

[0006]

That is, the present invention provides a method for manufacturing a wristwatch band for achieving the above object by connecting a wristband having a diameter slightly larger than the inner diameter of the hole to the hole provided in the outer piece. A plurality of pieces formed of stainless steel or titanium by press-fitting the pins are integrally assembled as a band body by a connecting pin also formed of stainless steel or titanium. By heating the band to the recrystallization temperature range of the metal constituting the band and finally holding the band for a time determined by the metal constituting the band under this temperature range, the inner wall of the outer piece and the connecting pin are connected. The peripheral surface is firmly bonded to the peripheral surface by diffusion bonding.

[0007]

Embodiments of the present invention will be described below. FIG. 1 shows a method of manufacturing a wristwatch band in which an outer piece and a middle piece formed of stainless steel are integrally joined by using a connecting pin also formed of stainless steel.

An overhang portion 2 of the outer piece 2 having an H-shape in plan view.
b, a through-hole 2a whose inner diameter is slightly smaller than the diameter of the large-diameter portion 4a of the driving pin 4 is formed. First, the middle piece 3 is inserted between the left and right overhanging parts 2b, 2b of the outer piece 2. After the fitting, the driving pin 4 is pressed into the through-hole 2b from the outside of the left and right overhanging portions 2b, 2b with the small-diameter portion 4b facing first, so that the small-diameter portion 4b is inserted into the hole 3a provided in the middle block 3. The band body 1 is integrally assembled so as to be inserted (FIG. 1
a).

Next, the main body portion of the band body 1 thus assembled and integrated, that is, the portion whose length does not need to be adjusted, is housed in a non-oxidizing continuous furnace 9 as an electric furnace. Above, the band body 1 is heated to 550 ° C. to 650 ° C. which is a recrystallization temperature region of stainless steel (FIG. 1).
b).

[0010] Then, in this temperature range, about 3
When the band body 1 is held in the furnace 9 for one minute, the outer peripheral surface of the large-diameter portion 4a of the driving pin 4 and the outer piece 2 as shown in FIG.
The diffusion of atoms occurs between the inner peripheral surface of the through-hole 2a and the large diameter portion 4a of the driving pin 4 is integrally diffusion-bonded into the through-hole 2b of the outer piece 2 (FIG. 1c).

By the way, actually, a band 1 as a product
In order to provide a good corrosion resistance by applying a solution treatment to the band body 1 integrated with the
Although it is necessary to heat to 50 ° C. to 1150 ° C., even when heated to this temperature range, the diffusion bonding between the outer peripheral surface of the driving pin 4 and the inner peripheral surface of the through hole 2a of the outer piece 2 is as follows. This is performed without any trouble as seen in the embodiment.

(Embodiment 1) A through hole is provided in an outer piece made of stainless steel having a hardness of Hv174, and a through hole is formed in the outer piece.
At 335, the distance between the outer diameter of the large diameter portion and the inner diameter of the through hole is 0.0.
Eight specimens frictionally joined by press-fitting a pull-out pin made of 1.1 mm diameter stainless steel having a diameter difference of 2 mm and 0.04 mm to a depth of 1 mm and 2 mm, and press-fitting 1050 When the specimens were heated to a temperature of about 1 to about 1150 ° C., and then held in this temperature range for a certain period of time and subjected to diffusion bonding, the extraction forces were compared. The results shown in Table 1 were obtained.

[0013]

[Table 1]

(Embodiment 2) A through hole is provided in an outer piece made of stainless steel having a hardness of Hv320, and the hardness is Hv335.
Then, a withdrawal pin made of 1.1 mm diameter stainless steel having a diameter difference of 0.02 mm and 0.04 mm between the outer diameter of the large diameter portion and the inner diameter of the through hole has a depth of 1 mm and 2 mm. Table 2 shows the results obtained by comparing the extraction force of each of the eight samples that were press-fitted and friction-bonded and the eight samples that were press-fitted and diffusion-bonded.

[0015]

[Table 2]

On the other hand, in a second embodiment of the present invention, an outer piece 2 and a middle piece 3 formed of pure titanium are connected by a driving pin 4 formed of titanium alloy. The band piece 1 is press-fitted into the hole 2b of the outer piece 2 and integrally formed as a band body 1 by diffusion bonding.

In this embodiment, a band 1 of a non-lengthened portion is constructed by assembling an outer piece 2 and a middle piece 3 with a driving pin 4, and then the band 1 is placed in an electric furnace 9. After heating to 850 ° C. to 880 ° C., which is a recrystallization temperature range and a temperature range where crystal grains are not coarsened, about 4
This temperature is maintained in the vacuum furnace 9 for 5 minutes, and diffusion bonding is performed between the outer peripheral surface of the driving pin 4 and the inner peripheral surface of the through hole 2b of the outer piece 2 so that the two are integrally coupled. It was done.

(Embodiment 3) The hardness annealed by itself is Hv1
30 has an H-shaped outer piece with a hardness of Hv322, and the outer diameter of the large diameter portion is 0.01 mm, 0.0 mm
Eight specimens which were driven into a 1 mm and 2 mm depth of a 1.1 mm diameter alloy titanium pin having a diameter difference of 2 mm and 0.04 mm and frictionally joined, and The sample was heated in a vacuum furnace at 850 ° C. to 880 ° C., and the extraction force of each of the eight specimens held in the furnace at this temperature for 45 minutes was compared. The results shown in Table 3 were obtained. .

[0019]

[Table 3]

(Embodiment 4) A through hole of an outer piece made of pure titanium having a hardness of Hv232 and an H shape in plan view is provided with a hardness of Hv.
At 322, the distance between the outer diameter of the large diameter portion and the inner diameter of the through hole is 0.01.
1.1 with a diameter difference of mm, 0.02 mm and 0.04 mm
The pulling force of each of the driving pins was examined for eight sets of specimens into which frictional welding was performed by press-fitting a driving pin made of alloy titanium having a diameter of mm, and eight sets of specimens subjected to diffusion bonding in the same manner as in Example 3. However, the results shown in Table 4 were obtained.

[0021]

[Table 4]

From Tables 3 and 4, the large difference in the frictional joining when the diameter difference is small indicates that it is difficult to make a perfect circular hole in the outer piece formed of titanium. Even in this case, it has been found that, in the case where the diffusion bonding process is performed, the difference in the pulling force becomes small, and the reliability of the bonding can be improved.

FIG. 3 shows a third embodiment of the present invention in which a knurl pin is used as a connecting pin.

A knurled pin 14 made of stainless steel is inserted through the middle piece 13 and a knurled pin 1 formed on the inner surface of the outer piece 12 also made of stainless steel.
4 is slightly smaller in diameter than the outer diameter of both end portions 14a.
Then, both ends 14a of the knurled pin 14 are press-fitted and assembled as a band body 10 into an integrated body. Then, the band body 10 is heated in an electric furnace 19 to a temperature of 1050 ° C. to 1150 The band 10 was heated to a temperature range of ° C., and the band 10 was held in the furnace 19 for about 3 minutes.

As a result, diffusion of atoms occurs between the outer peripheral surfaces of both ends of the knurl pin 14 and the inner peripheral surface of the blind hole 12a of the outer piece 12, and the two are firmly and integrally connected by diffusion bonding.

(Example 5) An outer piece made of stainless steel having a hardness of Hv300 has a hardness of Hv345 and a thickness of 0.1 mm at both ends.
A specimen in which a knurl pin made of stainless steel having a diameter difference of 05 mm and 0.07 mm and having an outer diameter of 1.3 mm was pressed into a depth of 1.8 mm, and after being pressed, heated at 1150 ° C. With respect to the sample held at this temperature for 3 minutes, the extraction force was measured, and the results shown in Table 5 were obtained.

[0027]

[Table 5]

The above description has been made on the step of connecting the non-length adjusting portion of the wristwatch band. In the length adjusting portion provided at one end of the band body, the length of the outer piece previously positioned at the end portion is adjusted. Perform the diffusion bonding process with the hairpin etc. inserted in the hole, remove the hairpin etc. from the hole after finishing the process, insert a new hairpin with sufficient spring properties as an adjustment part here It will be assembled and completed as a wristwatch band.

[0029]

As described above, according to the present invention, at least a band body formed by press-fitting a connecting pin also made of stainless steel or titanium into a hole of an outer piece made of stainless steel or titanium is assembled. Heat to the recrystallization temperature range of the metal constituting the band body,
Since this temperature was maintained for a time determined by the metal constituting the band body, through heating to the recrystallization temperature region and maintaining the temperature at this temperature for a certain time,
Attachment due to diffusion of atoms occurs between the inner peripheral surface of the hole of the outer piece and the outer peripheral surface of the connection pin, and there is a variation between the outer diameter of the hole of the outer piece and the outer diameter of the connection pin, for example, within the range of a tolerance difference. Even so,
The stability of the wristband can be greatly improved by stably maintaining the connection between the fine members that make up the band body for a long period of time. By shortening the press-fit depth of the pin, it is possible to solve the restriction on the shape of the outer piece and to give the watch band a more novel design.

Moreover, the allowable setting range of the difference between the connecting pin and the inner diameter of the hole of the outer piece can be widened, and it is not necessary to separate and re-layer the members for securing the allowable setting range. The manufacturing cost of the band can be further reduced.

[Brief description of the drawings]

FIGS. 1 (a) to 1 (c) are views showing a manufacturing process of a wristwatch band according to an embodiment of the present invention.

FIGS. 2 (a) and 2 (b) are photographs showing, on an enlarged scale, a state of connection between an outer piece and a driving pin which are respectively connected by a diffusion bonding step and a simple press-fitting step.

FIGS. 3 (a) to 3 (c) are views showing a manufacturing process of a wristwatch band according to another embodiment of the present invention.

[Explanation of symbols]

 1, 10 Band body 2, 12 Outer piece 2a Through hole 3, 13 Middle piece 4 Driving pin 14 Knurling pin

Claims (5)

[Claims] A plurality of pieces made of stainless steel or titanium are formed by pressing a connecting pin having a diameter slightly larger than the inner diameter of the hole into a hole provided in the outer piece. The above-mentioned connecting pins are integrally assembled as a band body, and then the band body is heated at least to a recrystallization temperature region of a metal constituting the band body. A method for manufacturing a wristwatch band, characterized in that the wristband is held for a time determined by a metal constituting the band body. 2. A hole in the outer piece made of stainless steel,
The band body into which the plurality of pieces are assembled by press-fitting the connecting pin also made of stainless steel is heated to at least a recrystallization temperature range of 550 ° C. to 650 ° C., and then the band body is heated in the temperature range. 2. The method of manufacturing a wristwatch band according to claim 1, wherein the holding is performed for about 3 minutes. 3. A hole in the outer piece made of stainless steel,
The band body in which the plurality of pieces are assembled by press-fitting the connecting pins also made of stainless steel is heated to a temperature range of 1050 ° C. to 1150 ° C. necessary for a solution treatment that is not lower than a recrystallization temperature. 2. The method according to claim 1, wherein the band is held under the temperature range for about 3 minutes. 4. A band body in which a plurality of pieces are assembled by press-fitting a connecting pin also made of titanium into the hole of the outer piece made of titanium, and the band body having at least a recrystallization temperature region of 850 ° C.
2. The method of claim 1 wherein the band is heated to about 880 DEG C., and the band is held under the temperature range for about 45 minutes. 5. The wristwatch according to claim 1, wherein a connecting pin having a diameter larger than the inner diameter of the hole by 0.01 mm to 0.04 mm is press-fitted into a hole provided in the outer piece. Band manufacturing method.