Watch component and method for manufacturing watch component

Abstract

To provide a watch component and a method for manufacturing a watch component, the watch component having a pear-skin texture processed so that scratches are less noticeable even when gripped with tweezers.SOLUTION: The present invention relates to a watch component in which a pear-skin texture is formed, the average value of RSm of the roughness profile of the surface of the pear-skin texture being at least 40 μm and 135 μm or less, and the average value of a skewness Rsk of the roughness profile being at least -3.1 and 0 or less.SELECTED DRAWING: Figure 5A

Description

[Technical Field]

[0001] The present invention relates to a timepiece component and a method for manufacturing the timepiece component. [Background technology]

[0002] Blasting, as described in Patent Document 1, is known as a method for forming a matte finish on various timepiece parts such as the dial, case, back cover, and main plate. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 9-38864 Summary of the Invention [Problem to be solved by the invention]

[0004] However, when watch components that have been processed with a matte finish by blasting are grasped with tweezers during watch assembly, the convex portions are crushed and the scratches are easily noticeable. For this reason, there is a demand for watch components that have been processed with a matte finish and that do not show scratches even when grasped with tweezers, and a method for manufacturing watch components. [Means for solving the problem]

[0005] The watch component of the present disclosure is a watch component having a matte texture formed thereon, characterized in that the average value of the average length RSm of the roughness curve of the surface of the matte texture is 40 μm or more and 135 μm or less, and the average value of the skewness Rsk of the roughness curve is -3.1 or more and 0 or less.

[0006] The manufacturing method for watch components disclosed herein is a manufacturing method for watch components that forms a matte pattern in a processed area of ​​a substrate by irradiating the substrate with a laser, and is characterized in that the processing is performed so that the average value of the average length RSm of the surface roughness curve of the matte pattern is 40 μm or more and 135 μm or less, and the average value of the skewness Rsk of the roughness curve is -3.1 or more and 0 or less. [Brief explanation of the drawings]

[0007] [Figure 1] FIG. 1 is a front view showing a timepiece according to an embodiment. [Figure 2] 1 is a schematic cross-sectional view showing a laser irradiation device according to an embodiment. [Figure 3] FIG. 2 is a schematic plan view showing the scanning direction of a pulse laser and processing marks in the embodiment. [Figure 4A] FIG. 10 is a diagram showing a processing area in an embodiment. [Figure 4B] FIG. 10 is a diagram showing a processed region of a comparative example. [Figure 5A] FIG. 2 is a diagram showing the measured values ​​of each parameter of surface roughness in the examples. [Figure 5B] FIG. 10 is a diagram showing the measured values ​​of each parameter of the surface roughness of a comparative example. [Figure 6A] FIG. 10 is a diagram showing an example of a roughness curve according to an embodiment. [Figure 6B] FIG. 10 is a diagram showing an example of a roughness curve of a comparative example. DETAILED DESCRIPTION OF THE INVENTION

[0008] A timepiece 1 according to an embodiment of the present disclosure will now be described with reference to the drawings. 1 is a front view of the timepiece 1. In this embodiment, the timepiece 1 is configured as a wristwatch that is worn on the user's wrist. As shown in FIG. 1, timepiece 1 has a metal exterior case 2. Inside exterior case 2 are a circular dial 10, a second hand 3, a minute hand 4, an hour hand 5, a crown 7, button A 8, and button B 9. Dial 10 has hour marks 6 for indicating the time. The back of dial 10 is also equipped with a movement and other components (not shown).

[0009] The surface of the dial 10 of the timepiece 1 is laser-processed to create a matte finish similar to sandblasting. The laser processing method for the dial 10 will be described with reference to Figures 2 and 3. The base material 10A that constitutes the dial 10 is made of a metal material such as brass, titanium, stainless steel, pure iron, nickel silver, duralumin, steel, or an alloy containing one of these. However, the material of the base material 10A is not limited to these, and any material that is used for timepiece components and that can be laser processed may be used.

[0010] The laser irradiation device 20 that irradiates the base material 10A of the dial 10 with a pulsed laser includes a laser irradiation unit 21, a movement mechanism (not shown), and a control device 26, as shown in FIG. The laser irradiation unit 21 includes a laser emission unit 22 and a focusing optical system 23. The laser emission unit 22 emits a pulsed laser 24, which is a nanosecond laser having a pulse width on the nanosecond level. The focusing optical system 23 focuses the pulsed laser 24 onto the focusing section 24A. Because the energy of the pulsed laser 24 is high at the focusing section 24A, metal particles are removed from the surface of the substrate 10A. When the pulsed laser 24 is irradiated onto the substrate 10A once, as shown in FIG. 3 , a recess, i.e., a processed mark 31, having a spot diameter R controlled by the focusing optical system 23 is formed in the processed region 30 on the surface of the substrate 10A. In this embodiment, the laser irradiation unit 21 is set to irradiate a pulsed laser 24 with a frequency f=160 kHz and a spot diameter R=30 μm.

[0011] The movement mechanism may be, for example, a mechanism for moving a table on which the substrate 10A to be processed is placed in the X-axis and Y-axis directions, and may be any mechanism that can move the pulsed laser 24 irradiated from the laser irradiation unit 21 relative to the substrate 10A in the scanning direction. As shown in Fig. 3, the movement mechanism of this embodiment moves the laser irradiation unit 21 relative to the substrate 10A in the X1 direction, then moves it in the Y1 direction by a predetermined pitch P, then moves it in the X2 direction, and then moves it in the Y1 direction by the pitch P, repeating this operation. In this embodiment, the control device 26 controls the movement device to move the laser irradiation unit 21 relative to the substrate 10A in the X1 and X2 directions at a scanning speed V of 1500 mm / s, and the pitch P, which is the spacing in the Y1 direction, is set in the range of 0.3 to 1.15 times the spot diameter R. If the pitch P is set to less than 0.3 times the spot diameter R, the overlapping area of ​​adjacent machining marks 31 will increase, reducing machining efficiency. If the pitch P is set to more than 1.15 times the spot diameter R, the unmachined area will increase, detracting from the aesthetic appearance of the watch component. For this reason, the pitch P is preferably set in the range of 0.3 to 1.15 times the spot diameter R. Furthermore, the pitch P is more preferably set in the range of 0.3 to 1 times the spot diameter R.

[0012] When processing marks 31 with a spot diameter R are continuously formed by the pulse laser 24, the length α of the overlapping portion of the processing marks 31 in the scanning direction is α = RV / f, as shown in Fig. 3. Here, V / f is the distance traveled by the pulse laser 24 in one cycle when the pulse laser 24 with frequency f is continuously irradiated, that is, the travel distance from the irradiation position of the pulse laser 24 to the irradiation position of the next pulse laser 24. In this embodiment, it is set such that a part of the machining marks 31 continuous in the scanning direction overlaps, that is, 0 ≦ α < R. In this embodiment, since R = 30 μm, V = 1500 mm / s = 1500000 μm / s, and f = 160 kHz = 160000 Hz, α = 30 - 9.375 = 20.625 μm. Note that the expression that a part of each machining mark 31 overlaps includes the state where each machining mark 31 contacts, and 0 = α indicates that state. That is, that a part of each machining mark 31 overlaps means that each machining mark 31 is continuous without a gap.

[0013] The control device 26 alternately sets the irradiation on-time Ton and the irradiation off-time Toff of the pulsed laser 24, and controls each irradiation on-time Ton and irradiation off-time Toff at random times. Thereby, the machining marks 31 by laser machining are irregularly formed on the surface of the base material 10A, and rough machining such as sandblasting is performed. In this embodiment, since the frequency f of the pulsed laser 24 is 160 kHz, the period T of the pulsed laser 24 is 6.25 μm. The control device 26 sets the irradiation on-time Ton = T × Ron and the irradiation off-time Toff = T × Roff. Here, Ron and Roff are random integers. In this embodiment, Ron is a random integer in the range of 0 to 8, and Roff is a random integer in the range of 0 to 6. Note that random means having no regularity, being random, and irregular. While the laser irradiation unit 21 is moving in the X1 direction and the X2 direction, the control device 26 randomly sets the irradiation on-time Ton and the irradiation off-time Toff, and controls the irradiation of the pulsed laser 24. Further, while the laser irradiation unit 21 is moving in the Y1 direction, the control device 26 controls the irradiation of the pulsed laser 24 to be off. Thereby, the machining marks 31 by the irradiation of the pulsed laser 24 are continuously formed with various lengths in the X1 direction and the X2 direction which are the scanning directions, and since the length of the non-machined part is also randomly set, random machining marks 31 similar to sandblasting can be formed.

[0014] 2 and 3, laser processing is performed by moving the laser irradiation unit 21 in the X1 and X2 directions relative to the base material 10A, but in this embodiment, laser processing is performed by movement not only in the X1 and X2 directions but also in the Y1 and Y2 directions, and by movement in directions at 45 degrees to the X and Y directions. That is, in this embodiment, the matte pattern is processed by scanning the pulsed laser 24 with respect to the base material 10A from multiple directions. The control device 26 controls the pulse laser 24 and the moving device based on preset processing pattern data to process a predetermined matte finish pattern in the processing area 30. Therefore, by using the same processing pattern data, laser processing by the laser irradiation device 20 can always process the same matte finish pattern.

[0015] Next, an example in which the matte finish pattern is formed by laser processing and a comparative example in which the matte finish pattern is formed by sandblasting will be compared and described. Fig. 4A shows an example of a matte finish pattern formed by laser processing. Fig. 4B shows an example of a matte finish pattern formed by sandblasting. As shown in Fig. 4A and Fig. 4B, ten reference lines, each with a reference length of 250 µm, were set in an area of ​​a predetermined size, for example, 500 µm x 700 µm, and the surface roughness was measured along each reference line using a surface roughness measuring instrument. Fig. 5A is a diagram showing the measured values ​​of each parameter of surface roughness in an example. Fig. 5B is a diagram showing the measured values ​​of each parameter of surface roughness in a comparative example. Note that there are two types of surface roughness measuring instruments: contact type, which uses a stylus, and non-contact type, which uses a laser or the like. In this embodiment, measurements were performed using a non-contact type surface roughness measuring instrument. Fig. 6A shows a roughness curve of the example measured with a surface roughness measuring instrument along one of the ten reference lines in Fig. 4A. Fig. 6B shows a roughness curve of the comparative example measured with a surface roughness measuring instrument along one of the ten reference lines in Fig. 4B.

[0016] As shown in Fig. 5A, in the example, the average value of the average length RSm of the roughness curve is 94.03 µm, which is within the range of 40 µm or more and 135 µm or less. On the other hand, as shown in Fig. 5B, in the comparative example, the average value of the average length RSm of the roughness curve is 34.83 µm, which is outside the range of 40 µm or more and 135 µm or less. Therefore, as shown in Fig. 6A, the spacing between the projections and recesses in the roughness curve of the example is larger than that of the comparative example shown in Fig. 6B. The average value of the average length RSm being within a predetermined range means that even if the average length RSm of some roughness curves is outside the range, the average value of the average lengths RSm of a plurality of roughness curves is within the range. The same applies to other parameters.

[0017] As shown in FIG. 5A, in the example, the average value of skewness Rsk is -0.43, which is within the range of -3.1 or more and 0 or less. As shown in FIG. 5B, in the comparative example, the average value of skewness Rsk is -0.03, which is within the range of -3.1 or more and 0 or less. Note that the average value of skewness Rsk in the comparative example is closer to 0 than in the example. Therefore, in the comparative example, the surface irregularities are approximately uniform with respect to the average line, whereas in the example, the surface irregularities are biased upward with respect to the average line compared to the comparative example.

[0018] As shown in Fig. 5A, in the example, the average value of the root mean square height Rq of the roughness curve is 1.16 µm, which is within the range of 0.7 µm to 1.8 µm, whereas as shown in Fig. 5B, in the comparative example, the average value of the root mean square height Rq of the roughness curve is 0.48 µm, which is outside the range of 0.7 µm to 1.8 µm. As shown in Fig. 5A, in the example, the average value of the arithmetic mean height Ra of the roughness curve is 0.95 µm, which is within the range of 0.6 µm or more and 1.5 µm or less. On the other hand, as shown in Fig. 5B, in the comparative example, the average value of the arithmetic mean height Ra of the roughness curve is 0.38 µm, which is outside the range of 0.6 µm or more and 1.5 µm or less. Therefore, as shown in FIGS. 6A and 6B, the difference in height between the projections and recesses is greater in the example than in the comparative example.

[0019] According to this embodiment, the matte texture is formed by laser processing, the average value of the average length RSm of the surface roughness curve is 40 μm or more and 135 μm or less, and the average value of the skewness Rsk is -3.1 or more and 0 or less, so scratches caused when the watch component on which the matte texture is formed is held with tweezers or the like are less noticeable. In other words, when the dial 10 is grasped with tweezers or the like, a certain load is applied to the matte surface on which the matte pattern is formed, crushing the convex portions. Therefore, if the spacing between the convex and concave portions of the matte pattern, i.e., the average length RSm, is small and the convex and concave portions are biased downward relative to the average line, i.e., the skewness Rsk is positive and the convex portions are sharp, multiple convex portions are easily crushed when the timepiece component is grasped with tweezers, and the crushed convex portions appear connected and linear, making scratches more noticeable. Furthermore, if the average value of the average length RSm is greater than 135 μm, the spacing between the convex and concave portions of the matte pattern becomes too wide, reducing the matte pattern-like appearance. If the skewness Rsk is less than -3.1, the convex portions of the matte pattern become flat and their area is significantly larger than that of the concave portions, reducing the matte pattern-like appearance. Therefore, by forming irregularities in the processing area 30 of the base material 10A by irradiating it with a laser, and by setting the average length RSm of the surface roughness curve of the processing area 30 to 40 μm or more and 135 μm or less, and the skewness Rsk to -3.1 or more and 0 or less, it is possible to express a matte pattern and make the convex portions less likely to be crushed when grasped with tweezers, thereby making scratches less noticeable and suppressing a decrease in the design of the dial 10, which is a watch component.

[0020] By using the registered processing pattern, the laser irradiation device 20 can reproduce the same matte finish pattern, enabling the mass production of dials 10 of consistent quality. This makes it possible to manufacture watches 1 with dials 10 that have a matte finish with a subdued gloss, improving the commercial value of the watches 1.

[0021] [Variations] The scanning direction of the pulse laser 24 is not limited to that in the above embodiment. That is, the scanning direction of the pulse laser 24 may be one direction, two directions, or three or more directions. For example, in the case of a dial, the matte pattern may be processed by scanning the pulse laser 24 along a first direction connecting 12 o'clock and 6 o'clock, a second direction connecting 2 o'clock and 8 o'clock, and a third direction connecting 4 o'clock and 10 o'clock.

[0022] The configuration of the laser irradiation device 20, and processing conditions such as the output level of the pulse laser 24, scanning speed V, frequency f, irradiation on time Ton, and irradiation off time Toff can be set appropriately depending on the type and material of the watch component to be processed.

[0023] The timepiece parts to be laser processed are not limited to the dial 10, but may also be various other timepiece parts such as the case, back cover, main plate, oscillating weight, second bridge, gear train bridge, balance bridge, back support, etc. The processing area may be the entire surface of the timepiece part, or only a part of it, and the scanning path may also be set according to the processing area, design, etc.

[0024] Summary of this disclosure The watch component of the present disclosure is a watch component having a matte texture formed thereon, characterized in that the average value of the average length RSm of the roughness curve of the surface of the matte texture is 40 μm or more and 135 μm or less, and the average value of the skewness Rsk of the roughness curve is -3.1 or more and 0 or less. According to the present disclosure, the average value of the average length RSm of the roughness curve of the surface of the matte textured pattern is 40 μm or more and 135 μm or less, and the average value of the skewness Rsk of the roughness curve is -3.1 or more and 0 or less, so scratches caused when the watch component on which the matte textured pattern is formed is held with tweezers or the like are less noticeable. As a result, the watch component can be easily handled when assembling the watch, and scratches on the matte textured portion are less noticeable, which prevents a decrease in the design of the watch component. That is, if the average value of the average length RSm is less than 40 μm, the intervals between the projections and recesses of the matte texture will be narrow, and when the watch component is held with tweezers, multiple projections will appear crushed and connected, making scratches more noticeable. Also, if the average value of the average length RSm is greater than 135 μm, the intervals between the projections and recesses of the matte texture will be too wide, and the matte texture will not look like a matte texture. Furthermore, if the skewness Rsk is less than -3.1, the convex portions of the matte texture will be flattened and their area will be significantly larger than that of the concave portions, reducing the matte texture appearance. Furthermore, if the skewness Rsk is greater than 0, the convex portions will be sharp and will be easily crushed when hit with tweezers or the like, making scratches more noticeable. Therefore, by setting the average length RSm of the roughness curve of the textured surface to 40 μm or more and 135 μm or less, and the skewness Rsk to -3.1 or more and 0 or less, it is possible to express a matte pattern and make the convex parts less likely to be crushed when grasped with tweezers, which makes scratches less noticeable and prevents a decrease in the design of the watch part.

[0025] In the timepiece component of the present disclosure, it is preferable that the average value of the root mean square height Rq of the roughness curve is 0.7 μm or more and 1.8 μm or less. The design quality of the matte finish pattern can be improved by setting the average value of the root mean square height Rq of the surface roughness curve of the matte finish pattern to 0.7 μm or more and 1.8 μm or less. Since the root mean square height Rq corresponds to the standard deviation of height, if the average value of the root mean square height Rq is less than 0.7 μm, the unevenness in the height of the unevenness becomes small, resulting in a regular unevenness, and the matte finish pattern becomes less resembling a matte finish pattern. Furthermore, if the average value of the root mean square height Rq is greater than 1.8 μm, the unevenness in the height of the unevenness becomes too great, and the matte finish pattern becomes less resembling a matte finish pattern. In contrast, the design quality of the matte finish pattern can be improved by setting the average value of the root mean square height Rq to 0.7 μm or more and 1.8 μm or less.

[0026] In the timepiece component of the present disclosure, it is preferable that the average value of the arithmetic mean height Ra of the roughness curve is 0.6 μm or more and 1.5 μm or less. The design quality of the pearskin pattern can be improved by setting the average value of the arithmetic mean height Ra of the surface roughness curve of the pearskin pattern to 0.6 μm or more and 1.5 μm or less. That is, if the average value of the arithmetic mean height Ra is less than 0.6 μm, the height of the irregularities becomes small, and the appearance of the pearskin pattern decreases. On the other hand, if the average value of the arithmetic mean height Ra is greater than 1.5 μm, the height of the irregularities becomes too large, and the appearance of the pearskin pattern decreases. In contrast, by setting the average value of the arithmetic mean height Ra to 0.6 μm or more and 1.5 μm or less, the design quality of the pearskin pattern can be improved.

[0027] In the timepiece component of the present disclosure, it is preferable that the matte pattern is formed by irradiating the timepiece component with a laser. When forming a matte finish by laser irradiation, the same matte finish can be reproduced by using a registered processing pattern, enabling the mass production of watch parts with consistent quality.

[0028] In the timepiece component of the present disclosure, it is preferable that the matte pattern is formed by scanning the timepiece component with a laser from multiple directions. By scanning the laser in multiple directions, it is possible to create a matte pattern that looks more matte.

[0029] In the timepiece parts of the present disclosure, the timepiece parts are preferably any of a dial, case, back cover, main plate, oscillating weight, second bridge, train wheel bridge, balance bridge, and back clamp. According to the present disclosure, it is possible to express a matte pattern on these watch parts and make scratches less noticeable when gripped with tweezers, thereby improving the workability of assembling the watch parts and preventing a decrease in the design of the watch parts.

[0030] In the timepiece component of the present disclosure, the base material of the timepiece component is preferably any one of brass, titanium, stainless steel, pure iron, nickel silver, duralumin, steel, and alloys thereof. By using various metal materials as the substrate and roughening the surface with laser processing, it is possible to provide watch parts with a luxurious feel. Furthermore, laser processing can be easily performed by adjusting the output depending on the type of substrate, and it is also easy to set the processing area, so productivity can be improved compared to sandblasting.

[0031] The manufacturing method for watch components disclosed herein is a manufacturing method for watch components that forms a matte pattern in a processed area of ​​a substrate by irradiating the substrate with a laser, and is characterized in that the processing is performed so that the average value of the average length RSm of the surface roughness curve of the matte pattern is 40 μm or more and 135 μm or less, and the average value of the skewness Rsk of the roughness curve is -3.1 or more and 0 or less. According to the present disclosure, a matte finish is produced in which the average value of the mean length RSm of the surface roughness curve is 40 μm or more and 135 μm or less, and the average value of the roughness curve skewness Rsk is -3.1 or more and 0 or less, making it possible to make scratches less noticeable when the watch component on which the matte finish is formed is held with tweezers or the like. As a result, the watch component can be easily handled when assembling the watch, and because scratches in the matte finish portion are less noticeable, it is possible to prevent a decrease in the design of the watch component.

[0032] In the manufacturing method for the watch component of the present disclosure, it is preferable to process the surface so that the average value of the root mean square height Rq of the roughness curve is 0.7 μm or more and 1.8 μm or less. According to the present disclosure, a pear-skin pattern is processed in which the average value of the root mean square height Rq of the surface roughness curve is 0.7 μm or more and 1.8 μm or less, so that when unevenness is formed in the processed area by laser irradiation, the design of the pear-skin pattern can be improved.

[0033] In the manufacturing method for the watch component of the present disclosure, it is preferable to process the surface so that the average value of the arithmetic mean height Ra of the roughness curve is 0.6 μm or more and 1.5 μm or less. According to the present disclosure, a matte pattern is processed in which the average value of the arithmetic mean height Ra of the surface roughness curve is 0.6 μm or more and 1.5 μm or less, so that when unevenness is formed in the processed area by laser irradiation, the design of the matte pattern can be improved. [Explanation of symbols]

[0034] 1...watch, 10...dial, 10A...base material, 20...laser irradiation device, 24...pulse laser, 26...control device, 30...processing area, 31...processing marks.

Claims

1. A watch component on which a matte pattern is formed, The average value of the average length RSm of the roughness curve of the surface of the pear-skin pattern is 40 μm or more and 135 μm or less, The average value of the skewness Rsk of the roughness curve is -3.1 or more and 0 or less. A watch component characterized by:

2. The timepiece component according to claim 1, The average value of the root mean square height Rq of the roughness curve is 0.7 μm or more and 1.8 μm or less. A watch component characterized by:

3. The timepiece component according to claim 1, The average value of the arithmetic mean height Ra of the roughness curve is 0.6 μm or more and 1.5 μm or less. A watch component characterized by:

4. The timepiece component according to claim 1, The matte pattern is formed by irradiating the watch component with a laser. A watch component characterized by:

5. The timepiece component according to claim 4, The matte pattern is formed by scanning the watch component with a laser from multiple directions. A watch component characterized by:

6. The timepiece component according to claim 1, The timepiece part is any one of a dial, a case, a back cover, a main plate, an oscillating weight, a second bridge, a train wheel bridge, a balance bridge, and a back support. A watch component characterized by:

7. The timepiece component according to claim 1, The base material of the watch component is any one of brass, titanium, stainless steel, pure iron, nickel silver, duralumin, steel, and alloys thereof. A watch component characterized by:

8. A method for manufacturing a watch component, which forms a matte pattern in a processed area of ​​a substrate by irradiating the substrate with a laser, comprising: The average value of the average length RSm of the roughness curve of the surface of the pear-skin pattern is 40 μm or more and 135 μm or less, The roughness curve is processed so that the average value of the skewness Rsk is -3.1 or more and 0 or less. A method for manufacturing a watch part, comprising:

9. 9. The method for manufacturing a watch component according to claim 8, The surface is processed so that the average value of the root mean square height Rq of the roughness curve is 0.7 μm or more and 1.8 μm or less. A method for manufacturing a watch part, comprising:

10. 9. The method for manufacturing a watch component according to claim 8, The surface is processed so that the average value of the arithmetic mean height Ra of the roughness curve is 0.6 μm or more and 1.5 μm or less. A method for manufacturing a watch part, comprising:

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