JP6419391B2 - Watch case - Google Patents

Description

  The present disclosure relates to a watch case.

  In order to give a wristwatch a high-class feeling, it has been proposed that a watch case, which is an exterior part used for housing a movement or the like, is made of ceramics.

  For example, Patent Document 1 discloses a watch case in which a part or all of a case and a back cover are made of a ceramic or artificial gemstone material.

Japanese Patent Laid-Open No. 63-249085

  The watch case of the present disclosure is made of ceramics. Moreover, the fitting surface facing the lid member fitted together is provided. The fitting surface has an arithmetic average roughness Ra obtained from the roughness curve of 0.6 μm or less and a protruding peak height Rpk obtained from the roughness curve of 0.9 μm or less.

It is the schematic which shows an example of the timepiece case of this indication.

  A watch case of a wristwatch is configured to be capable of attaching or removing a lid member (hereinafter referred to as “detaching”). This lid member is a component that prevents water, dust, and the like from entering the inside of the watch case. Here, when replacing the wristwatch battery, it is necessary to remove the lid member from the watch case. When the watch case is made of ceramics, when the cover member is repeatedly attached and detached to replace the battery, the fitting surface of the watch case facing the lid member in the fitting with the lid member (hereinafter simply referred to as the fitting surface). May wear out easily). And if the fitting surface in a timepiece case wears out, water, dust, etc. will penetrate | invade easily from between a cover member and a timepiece case, and the waterproofness and dustproofness of a wristwatch will fall. Moreover, the waste generated when the fitting surface wears enters the movement, causing a failure.

  The watch case of the present disclosure can maintain waterproofness and dustproofness for a long period of time because the fitting surface hardly wears even when the lid member is repeatedly attached and detached. Hereinafter, the watch case of the present disclosure will be described in detail with reference to FIG. In the watch case 1 shown in FIG. 1, the lid member is fitted from below in the drawing, and the hatched surface is the fitting surface 2.

  The watch case 1 of the present disclosure is made of ceramics. Here, the ceramic is aluminum oxide ceramics, zirconium oxide ceramics, silicon nitride ceramics, silicon carbide ceramics, or the like. Among the ceramics, if the watch case 1 of the present disclosure is made of zirconium oxide ceramics, it is difficult to damage even after long-term use, so that the aesthetic appearance is hardly impaired.

  Here, the zirconium oxide ceramic is a ceramic mainly composed of zirconium oxide, and contains 70% by mass or more of zirconium oxide out of 100% by mass of all components constituting the ceramic. The content of the main component can be calculated by the following method. First, the watch case 1 is measured using an X-ray diffractometer (XRD), and the obtained 2θ (2θ is a diffraction angle) value is identified by a JCPDS card. At this time, when the watch case 1 is made of a zirconium oxide ceramic, the presence of zirconium oxide is confirmed.

Next, using an ICP (Inductively Coupled Plasma) emission spectroscopic analyzer (ICP), quantitative analysis of metal components (other than oxygen, carbon, nitrogen, etc.) among the identified components is performed. Then, the content of the component (compound) identified by XRD is calculated from the result of quantitative analysis. For example, if the component identified by XRD is zirconium oxide, the content of zirconium (Zr) obtained by measurement by ICP is converted to zirconium oxide (ZrO ₂ ). If content converted here is 70 mass% or more, it is a zirconium oxide ceramic. In addition, it can confirm with the same method also about other ceramics.

  And the timepiece case 1 of this indication is provided with the fitting surface 2 which opposes the cover member fitted. The fitting surface 2 has an arithmetic average roughness Ra obtained from the roughness curve of 0.6 μm or less and a protruding peak height Rpk obtained from the roughness curve of 0.9 μm or less.

  Here, the arithmetic average roughness Ra is a value defined in JIS B 0601 (2013). Further, the protruding peak height Rpk is defined in JIS B 0671-2 (2002) and is defined as follows. First, in the central portion of the load curve including 40% of the measurement points of the roughness curve, the straight line where the dividing line of the load curve drawn with the difference in load length ratio being 40% is the most gentle is defined as the equivalent line. . Next, a core portion is defined between two height positions where the equivalent straight line intersects the vertical axis at the load length ratios of 0% and 100%. In the roughness curve, the average height of the protruding ridge above the core is the protruding ridge height Rpk.

  Since the watch case 1 of the present disclosure satisfies the above-described configuration, the unevenness of the fitting surface 2 is small and the protruding peak portion is small, so that it protrudes even when the lid member is repeatedly attached and detached. Mountains are less likely to wear. Therefore, the watch case 1 of the present disclosure can maintain waterproofness and dustproofness for a long period of time even when the lid member is repeatedly attached and detached. In addition, when the arithmetic average roughness Ra is 0.1 μm or more and the protruding peak height Rpk is 0.06 μm or more on the fitting surface 2, the cover member is formed by the presence of a peak. Easy to put on and take off.

  Further, the fitting surface 2 in the watch case 1 of the present disclosure may have a core portion level difference Rk obtained from a roughness curve of 0.8 μm or less. Here, the level difference Rk of the core part is defined in JIS B 0671-2 (2002) and is an index indicating the level difference between the upper side and the lower side of the core part described above in the roughness curve.

  If such a configuration is satisfied, the fitting surface 2 of the watch case 1 of the present disclosure has a small variation in the height of the core portion, so that the lid member contacts the portion corresponding to the core portion of the fitting surface 2. Even so, the part is less likely to wear. Therefore, even if the attachment and detachment of the lid member is repeated, the waterproofness and dustproofness can be maintained longer. In addition, in the fitting surface 2, if the level difference Rk of the core part is 0.11 μm or more, the lid member can be easily attached and detached while having excellent waterproof properties and excellent dust resistance.

  Further, the fitting surface 2 in the watch case 1 of the present disclosure may have a ratio Rpk / Rk between the level difference Rk of the core portion and the protruding peak height Rpk of 0.7 or less. If such a configuration is satisfied, the fitting surface 2 of the watch case 1 of the present disclosure has a surface property in which the protruding peak portion is small and the height variation of the core portion is small. Even if it repeats, waterproofness and dustproofness can be maintained longer. In addition, if the ratio Rpk / Rk is 0.5 or more in the fitting surface 2, the lid member can be easily attached and detached while having excellent waterproof properties and excellent dust resistance.

  Further, the fitting surface 2 in the watch case 1 of the present disclosure may have a negative skewness Rsk obtained from a roughness curve. Here, the skewness Rsk is defined in JIS B 0601 (2013), and is an index indicating a ratio between a peak portion and a valley portion when the average roughness height is a center line. If the skewness Rsk is negative, it indicates that the region that is a peak is larger than the valley. If such a configuration is satisfied, even if the lid member is repeatedly attached and detached, the crest portion itself in the fitting surface 2 becomes difficult to be chipped, so that the waterproofness and dustproofness can be maintained for a longer time.

  Further, the fitting surface 2 in the watch case 1 of the present disclosure may have an average peak height Rpm determined from a roughness curve of 0.5 μm or less. Here, the average peak height Rpm is the average height of the highest peak part included in each section in the section in which only the reference length is extracted from the roughness curve in the direction of the average line and the reference length is divided into five equal parts. When the height from the top to the top is Rpi, it is the average value of Rpi in these five sections. If such a configuration is satisfied, the fitting surface 2 of the watch case 1 of the present disclosure has few protruding peaks, and therefore, the wear on the fitting surface 2 is small even when the lid member is repeatedly attached and detached. The waterproofness and dustproofness can be maintained longer. In addition, in the fitting surface 2, if the average peak height Rpm is 0.2 μm or more, it is easy to attach and detach the lid member while having excellent waterproofness and excellent dustproofness.

  Further, the fitting surface 2 in the watch case 1 of the present disclosure may have a root mean square slope RΔq of 10 ° or less. Here, the root mean square slope RΔq is specified in JIS B 0601 (2013), and is an index indicating the gentleness of the slope of the peak. If such a configuration is satisfied, the slope of the peak portion on the fitting surface 2 of the watch case 1 of the present disclosure becomes gentle, and even if the lid member is repeatedly attached and detached, the peak portion is not easily worn. And dustproofness can be maintained longer. In addition, in the fitting surface 2, if the root mean square slope RΔq is 3 ° or more, the lid member can be easily attached and detached while having excellent waterproof properties and excellent dust resistance.

  In addition, the fitting surface 2 in the watch case 1 of the present disclosure may have an average interval S of peak portions obtained from a roughness curve of 15 μm or less. Here, the average interval S between peak portions is defined by JIS B 0601 (1994) and is an index indicating the average value of the intervals between adjacent peak portions. If such a configuration is satisfied, the gap between the ridges where water, dust and the like easily enter is narrowed on the fitting surface 2 of the watch case 1 of the present disclosure, so that waterproofness and dustproofness are improved. be able to. In addition, if the average space | interval S of a peak part is 3 micrometers or more in the fitting surface 2, it will be easy to attach or detach a cover member, having the outstanding waterproofness and the outstanding dustproof property.

  Here, the arithmetic average roughness Ra, skewness Rsk, average peak height Rpm, and root mean square slope RΔq on the fitting surface 2 of the watch case 1 of the present disclosure can be measured in accordance with JIS B 0601 (2013). Good. Moreover, what is necessary is just to measure the average space | interval S of the peak part in the fitting surface 2 of the timepiece case 1 of this indication based on JISB0601 (1994). On the other hand, the protruding peak height Rpk and the core level difference Rk in the fitting surface 2 of the watch case 1 of the present disclosure may be measured in accordance with JIS B 0671-2 (2002). As measurement conditions, for example, the measurement length is 0.8 mm, the cutoff value is 1.0 mm, and the scanning speed of a stylus with a stylus radius of 2 μm may be set to 1 mm / second. Then, it is only necessary to measure at least three places on the fitting surface 2 and obtain the average value.

  Moreover, the timepiece case 1 of the present disclosure may have a groove portion 3 on the fitting surface 2 as shown in FIG. This groove part 3 is a part fitted to the protrusion when the cover member has a protrusion. Thus, if the timepiece case 1 of the present disclosure has the groove portion 3 and the projection of the lid member and the groove portion 3 are fitted, the lid member can be more firmly fixed to the timepiece case 1. it can.

  Further, as shown in FIG. 1, the watch case 1 of the present disclosure may have a through hole 4 that is a hole for inserting a crown on the fitting surface 2. Note that the crown is for performing a time adjustment operation of the clock from the outside.

  Hereinafter, a method for manufacturing the watch case 1 of the present disclosure will be described. Here, the case 1 made of a zirconium oxide ceramic will be described as an example.

First, zirconium oxide (ZrO ₂ ) powder as a main raw material is put in a mill together with a solvent and a ball and pulverized to a predetermined particle size to produce a slurry. Next, after adding a binder to the obtained thriller, granules are obtained by spray drying using a spray dryer.

  Next, the granule, thermoplastic resin, wax and the like are put into a kneader and kneaded while heating to obtain a clay. And the pellet used as the raw material for injection molding (injection molding) is obtained by throwing the obtained clay into a pelletizer. Next, the obtained pellets are put into an injection molding machine (injection molding machine) and injection molded to obtain a watch case-shaped molded body.

  As described above, in order to obtain a watch case-shaped molded body, a molding die capable of obtaining a watch case shape is prepared based on a general injection molding method, and this is placed in an injection molding machine and injection molded. That's fine. Here, the surface property of the inner surface of the mold is transferred to the surface of the molded body. Therefore, in order to obtain the fitting surface 2 having an arithmetic average roughness Ra of 0.6 μm or less and a protruding ridge height Rpk of 0.9 μm or less, a polishing amount by surface treatment such as barrel polishing after firing is set. What is necessary is just to produce a molded object using the shaping | molding die which has the surface property weighed on the inner surface. In the fitting surface 2, the core level difference Rk is 0.8 μm or less, the Rpk / Rk value is 0.7 or less, the skewness Rsk is negative, and the average peak height Rpm is 0.5 μm. The same applies to the following cases, when the root mean square slope RΔq is set to 10 ° or less, or the average interval S between the peak portions is set to 15 μm or less.

  Next, for example, when zirconium oxide is the main raw material, the obtained watch case-shaped molded body is fired at a maximum temperature of 1350 ° C. or higher and 1550 ° C. or lower in an air atmosphere to obtain a sintered body. . And the timepiece case 1 of this indication is obtained by carrying out barrel polishing of the obtained sintered compact. In addition, since baking conditions change with the shape and magnitude | size of a product, what is necessary is just to adjust as needed.

  Examples of the present disclosure will be specifically described below, but the present disclosure is not limited to these examples.

  On the fitting surface, samples (watch cases) having different arithmetic average roughness Ra, protruding peak height Rpk, and core level difference Rk were prepared, and a lid member attachment / detachment test was performed.

First, raw material powder was obtained by weighing and mixing zirconium oxide (ZrO ₂ ) at 94.8 mass% and stabilizer yttrium oxide (Y ₂ O ₃ ) at 5.2 mass%. . Then, with respect to the raw material powder 100 wt%, chromium oxide as a pigment component (Cr ₂ O _3), and the iron oxide (Fe ₂ O ₃₎ and cobalt oxide (Co ₃ O ₄₎ was added 4 wt% in total . Further, water was added to these and pulverized and mixed with a ball mill to obtain a slurry.

  Next, after adding a binder to this slurry, granules were obtained by spray drying using a spray dryer. Then, a thermoplastic resin and a wax were added to the obtained granules, and the mixture was put into a kneader and kneaded while heating to obtain a clay. Next, the obtained kneaded material was put into a pelletizer to obtain pellets as a raw material for injection molding. Then, the pellets were put into an injection molding machine to obtain a watch case-shaped molded body.

  Here, the surface property of the inner surface of the molding die installed in the injection molding machine is determined by considering the amount of polishing by barrel polishing after firing, and the mating surface of each sample has the arithmetic average roughness Ra, protruding peak shown in Table 1. The height Rpk and the core level difference Rk were set.

  Next, the watch case-shaped molded body was fired at a maximum temperature of 1500 ° C. in an air atmosphere to obtain a watch case-shaped sintered body. And each sample was obtained by carrying out barrel polishing of the obtained sintered compact.

  And about each obtained sample, using a contact-type surface roughness meter, based on JIS B 0601 (2001) and JIS B 0671-2 (2002), arithmetic average roughness Ra, protrusion peak in a fitting surface The part height Rpk and the core level difference Rk were measured. As measurement conditions, the measurement length is 0.8 mm, the cutoff value is 1.0 mm, the scanning speed of the stylus with a stylus radius of 2 μm is set to 1 mm / second, and measurement is performed at three locations on the mating surface. The average value was calculated.

  Next, the attaching / detaching test of the lid member was performed using each sample. First, as the lid member, a stainless steel lid member fitted to the fitting surface of each sample was used. Next, the lid member was attached to and detached from each sample 10 times using a commercially available lid member closing machine. At this time, using a push-pull gauge, a load σ0 required for attaching the lid member for the first time and a load σ1 required for attaching the lid member for the 10th time were measured. From the load σ0 and the load σ1, the required load reduction rate Δσ (%) = (σ0−σ1) / σ0 × 100 was calculated. Then, the samples were ranked in order from the lowest required load reduction rate Δσ. That is, the sample with the lowest necessary load reduction rate Δσ was ranked first, and the sample with the highest necessary load reduction rate Δσ was ranked lowest. The higher the required load reduction rate Δσ is, the more the fitting surface is not worn and the adhesion between the fitting surface and the lid member can be maintained even when the lid member is repeatedly attached and detached. Show.

  The results are shown in Table 1.

  As shown in Table 1, sample no. The rank of the required load reduction rate Δσ of 3 to 6 was high. From this result, when the arithmetic average roughness Ra is 0.6 μm or less and the protruding ridge height Rpk is 0.9 μm or less on the fitting surface, even if the lid member is repeatedly attached and detached, waterproofness and dustproof It was found that sex can be maintained for a long time.

  Sample No. 4 to 6 are sample Nos. Compared with 3, the required load reduction rate Δσ was higher. From this result, it was found that if the level difference Rk of the core portion is 0.8 μm or less on the fitting surface, the waterproofness and dustproofness can be maintained for a longer time.

  Furthermore, sample no. Samples Nos. 5 and 6 are sample Nos. Compared to 4, the rank of the required load reduction rate Δσ was higher. From this result, it was found that if the ratio Rpk / Rk between the core level difference Rk and the protruding peak height Rpk is 0.7 or less on the fitting surface, the waterproofness and dustproofness can be maintained longer. .

  Next, samples with different skewness Rsk on the fitting surface were prepared, and a lid member attachment / detachment test was performed.

  As a manufacturing method, the surface properties of the inner surface of the molding die installed in the injection molding machine are taken into account the amount of polishing by barrel polishing after firing, and the fitting surface of each sample becomes the skewness Rsk shown in Table 2. Except that the sample was changed as described above, the sample N o. 6 was the same as the manufacturing method. Sample No. 7 shows the sample No. of Example 1. Same as 6.

  And about each obtained sample, skewness Rsk was measured in the fitting surface, About the measurement conditions, it was the same as that of Example 1. FIG. The lid member attachment / detachment test was performed in the same manner as in Example 1.

  The results are shown in Table 2. The ranking of the required load reduction rate Δσ is made by comparing only the samples shown in Table 2.

  As shown in Table 2, sample no. Compared to sample No. 7, sample no. The required load decrease rate Δσ of 8 was low. From this result, it was found that if the skewness Rsk is negative, the waterproofness and dustproofness can be maintained for a longer time.

  Next, samples having different average peak heights Rpm on the fitting surface were produced, and a lid member attachment / detachment test was performed.

  As the production method, the surface properties of the inner surface of the molding die installed in the injection molding machine were determined by considering the amount of polishing by barrel polishing after firing, and the average crest height Rpm shown in Table 3 for the fitting surface of each sample is shown in Table 3. Except that the sample was changed so that 8 was the same as the manufacturing method. Sample No. 9 is the sample No. of Example 2. Same as 8.

  And about each obtained sample, although the average peak height Rpm was measured in the fitting surface, it was the same as that of Example 1 about measurement conditions. The lid member attachment / detachment test was performed in the same manner as in Example 1.

  The results are shown in Table 3. The ranking of the required load reduction rate Δσ is made by comparing only the samples shown in Table 3.

  As shown in Table 3, Sample No. Compared to sample No. 9, sample no. The required load reduction rate Δσ of 10 and 11 was low. From this result, it was found that if the average peak height Rpm is 0.5 μm or less, the waterproofness and dustproofness can be maintained longer.

  Next, samples having different root mean square slopes RΔq on the fitting surface were prepared, and a lid member attachment / detachment test was performed.

  In addition, as a manufacturing method, the surface property of the inner surface of the molding die installed in the injection molding machine is taken into consideration, the amount of polishing by barrel polishing after firing, and the fitting surface of each sample has a root mean square slope shown in Table 4 Except for the change to be RΔq, the sample N o. 11 was the same as the manufacturing method. Sample No. 15 is the sample No. of Example 3. 11 is the same.

  And about each obtained sample, although the root mean square inclination R (DELTA) q was measured in the fitting surface, it was made to be the same as that of Example 1 about measurement conditions. The lid member attachment / detachment test was performed in the same manner as in Example 1.

  The results are shown in Table 4. The ranking of the required load reduction rate Δσ is made by comparing only the samples shown in Table 4.

  As shown in Table 4, Sample No. Sample No. The required load reduction rate Δσ of 12 to 14 was low. From this result, it was found that if the root mean square slope RΔq is 10 ° or less, waterproofness and dustproofness can be maintained longer.

  Next, on the fitting surface, samples having different average intervals S between the peak portions were produced, and a lid member attachment / detachment test was performed.

  In addition, as a manufacturing method, the surface property of the inner surface of the molding die installed in the injection molding machine is considered, and the amount of polishing by barrel polishing after firing is taken into consideration. Except that the average interval S was changed, the sample N. 12 was the same as the manufacturing method. Sample No. 19 is the sample No. of Example 4. 12 is the same.

  And about each obtained sample, based on JISB0601 (1994), although the average space | interval S of the peak part was measured in the fitting surface, it was made to be the same as that of Example 1. The lid member attachment / detachment test was performed in the same manner as in Example 1.

  The results are shown in Table 5. The ranking of the required load reduction rate Δσ is made by comparing only the samples shown in Table 5.

  As shown in Table 5, sample no. Compared to sample No. 19, sample no. The required load reduction rate Δσ of 16-18 was low. From this result, it was found that if the average interval S between the peak portions is 15 μm or less, the waterproofness and dustproofness can be maintained longer.

1: Watch case 2: Fitting surface 3: Groove part 4: Through hole

Claims (8)

Made of ceramics,
A fitting surface facing the fitted lid member;
The fitting surface is a watch case in which an arithmetic average roughness Ra obtained from a roughness curve is 0.6 μm or less and a protruding peak height Rpk obtained from the roughness curve is 0.9 μm or less.   The watch case according to claim 1, wherein the fitting surface has a core portion level difference Rk of 0.8 µm or less determined from a roughness curve.   3. The timepiece according to claim 1, wherein the fitting surface has a ratio Rpk / Rk between a level difference Rk of the core portion obtained from a roughness curve and the protruding peak height Rpk of 0.7 or less. Case.   4. The watch case according to claim 1, wherein the fitting surface has a negative skewness Rsk obtained from a roughness curve. 5.   5. The watch case according to claim 1, wherein the fitting surface has an average peak height Rpm determined from a roughness curve of 0.5 μm or less.   The timepiece case according to claim 1, wherein the fitting surface has a root mean square slope RΔq of 10 ° or less.   The watch case according to any one of claims 1 to 6, wherein the fitting surface has an average interval S between peak portions obtained from a roughness curve of 15 µm or less.   The watch case according to any one of claims 1 to 7, wherein the ceramic is a zirconium oxide ceramic.

Images