JPH06221954A - Device and method for inspecting waterproof performance of watch - Google Patents

Abstract

PURPOSE:To improve the inspection capacity of waterproof performance and also to judge qualities of the biting condition of a crystal to a body and the engaging condition of a back cap to the body, by producing an expansion strain by negative pressure air, in addition to a compression strain by pressurized air. CONSTITUTION:A case 3 is placed on a pedestal 7 within a capsule 1, the terminal 4a of a thickness sensor 4 is contacted with the center of a crystal 3b, and a standard position h0 is determined. Next, a pressure inlet valve 1d is opened, a vacuum inlet valve 1e is closed, pressurized air 12 is allowed to flow in the capsule 1, and the pressurization in the case 3 is started. As the pressurization is continued, the strain quantity generates a strain curve in the negative direction according to a compression strain generated in the case 3, and the curve reaches a pressure end point D. When the clearance exists in the case 3, the pressurized air leaks in the case 3 rapidly in the initial stage A-B and slowly in the middle stage B-C, and the strain quantity becomes constant in the later stage C-D. Then, when the valve 1d is closed, the valve 1e is opened and the decompression is done, a expansion strain is generated in the case 3 in the curve E-F-G region, the clearance is enlarged, the air within the case 3 is leaked, and the positive sttrain quantity of the case 3 can be measured.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a waterproof property inspection device and a waterproof property inspection method for inspecting the waterproof property of a timepiece.

[0002]

2. Description of the Related Art In a conventional timepiece waterproofness inspection apparatus, as shown in FIG.
Is poured and pressurized by an air pressurizer (not shown) to generate compressive strain in the timepiece or case 13 (hereinafter referred to as case) of the timepiece mounted on the table 17 in the capsule 11. It has been known that the process of generating the compressive strain is detected by the thickness sensor 14 in contact with the upper surface of the center of the glass 13b to judge the waterproof property of the case as a good product or a defective product. For example, Japanese Utility Model Laid-Open No. 55-116291 discloses such a conventional structure.

[0003]

In order to explain the problems associated with the conventional watertightness inspection device and watertightness inspection method for a timepiece, an example of a case with poor water resistance placed on the base 17 in the capsule 11 of FIG. 3 is taken as an example. Illustrated as.

FIG. 4 is a cross-sectional view of a case 13 showing an example at a normal pressure (usually close to 1 atm) before the pressurized air 12 is poured into the capsule 11, and FIG. It is sectional drawing of the case 13 which shows an example at the time of pressurization which flowed the pressurization air 12. The conventional timepiece waterproofness inspection device and waterproofness inspection method have the following problems.

FIG. 4 shows, as an example of the case 13 having poor waterproofness, there is a slight gap S between the lower surface of the body 13c of the case 13 and the rubber packing 15 attached to the outer peripheral groove of the back lid 13a of the case 13. Indicate the case. Figure 6
Pressurizes air 12 into the capsule,
7 is a strain curve showing a strain amount in the central portion of the case measured by the thickness sensor 14 in the process of pressurizing to. Reference position h indicated by the thickness sensor 14 up to the pressurization start point A at the time of measurement t _0
0 means that there is an inflow α of air into the case from the gap S (hereinafter referred to as inflow leak) up to t ₁ at the beginning of pressurization.
The amount of strain is measured as a straight line AB, and is smaller than the curve AB in the case of no gap. B at time t ₁
If pressure is further applied from the point, the case back 13a
Since it is pressed toward the c side, the gap S is closed as shown in FIG. Therefore, the distortion curve BCD after point B
Indicates that a distortion curve similar to the case without a gap is obtained, and even if there is a slight gap S in practice, it may be erroneously determined to be a good product in the determination of the waterproofness inspection.

FIG. 7 shows a distortion curve when the gap S is slightly large. Reference position h ₀ indicated by the thickness sensor 14 to the pressurization starting point A at the measurement time t ₀ is
When the pressurization is started, air flows into the case through the gap S and leaks. When the gap S is slightly large, as described above, since the gap S is not closed and a slight gap S1 remains, the pressurized air continues to flow into the case through the gap S1.

The compressed air 12 flows into the case 13 through a slight gap S1 and leaks, so that the compressive strain generated in the case tries to return to the original state. However, the pressurizing speed by the compressed air is faster than the restoring speed. In this case, compared with the strain amount of the strain curve AF measured in the case where there is no air leak gap, the strain amount measured by the strain curve AE after A in FIG. To be measured.

That is, when the speed of the compression strain due to the pressurized air is faster than the speed of the compression strain restoration due to the inflow of the pressurized air, the compression strain continues and progresses.
It was judged that the air did not flow into No. 1, and a defective product was sometimes mistakenly judged as a non-defective product. In addition, in the conventional waterproofness inspection device that generates compressive strain in the case by the pressurized air 12, in order to finish the inspection in the direction of pressurizing the case, the glass 13b and the back cover 13a are used.
Since it was pressed in the direction of the body 13c, it was difficult to find defective adhesion of glass and defective sticking of the back lid.

Therefore, the object of the present invention is to make the inside of the capsule negative pressure air in order to solve the above-mentioned conventional problems.
By setting the pressure to 3 atmospheres or the like, expansion strain is generated in the case, a slight gap S in the case is increased, and more air in the case flows out from the gap (hereinafter, referred to as outflow leak), and waterproof. It is to improve the ability to detect sex.

Another object of the present invention is to make it possible to judge whether or not the adhesion of the glass to the body of the glass or the condition of the back lid on the body of the glass is good or bad.

[0011]

In order to solve the above-mentioned problems, the present invention provides a timepiece waterproofness inspection apparatus and a waterproofness inspection method, which use negative pressure air in addition to the conventional compressive strain due to pressurized air. It is configured to generate expansion strain in the case.

[0012]

With the watertightness inspection device and the watertightness inspection method for a watch configured as described above, it is possible to separately perform pressurized air measurement and negative pressure measurement, and by combining both measurements continuously, It is possible to inspect the waterproofness while observing the effects of both pressurization and negative pressure. The order of pressurization and negative pressure can be arbitrarily selected, and a plurality of types of inspection methods can be determined according to the purpose of inspection.

[0013]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a main cross-sectional view of a waterproofness inspection device for a timepiece according to the present invention. The main difference from FIG. 3 showing a conventional example is that pressurized air 12 and negative pressure air 2 are arbitrarily selected. That was possible. That is, the air circulation port 1a provided in the capsule 1 is provided with a pressurized air port 1b connected to an air pressurizer (not shown) and a negative pressure air port 1c connected to an air negative pressure device (not shown). A pressurizing port valve 1d and a negative pressure port valve 1e are provided between the air ports 1b and 1c and the air circulating port 1a, respectively.

FIG. 2 is an example showing a strain curve of a case by the waterproofness inspection apparatus of the present invention. First, a case where pressure measurement is performed and then negative pressure measurement is performed will be described as an example. First, the case 3 is placed on the table 7 in the capsule 1 under normal pressure, and the terminal 4a of the thickness sensor 4 is brought into contact with the central portion of the glass 3b of the case, and the reference position h of the terminal 4a.
_{Set 0} .

Next, the pressurizing port valve 1d is opened and the negative pressure port valve 1e is closed into the capsule 1, and the pressurized air 12 from the air pressurizer is introduced from the pressurized air port 1b, and the case 3 The pressurization of is started. When the pressurization is further continued from the pressurization start point A,
The strain amount draws a strain curve in the (-) direction according to the compressive strain amount generated in Case 3, and reaches the pressurization end point D. In the case where there is a gap in the case 3, the air rapidly flows into the case during the initial pressurization A to B, and the air slowly flows into the case during the middle pressurization period B to C and leaks. Late C
In the cases of ~ D, the negative (-) strain amount becomes constant for the reason described above.

That is, in the pressure measurement of A to D,
The compressive strain of the case can be measured according to the amount of air flowing into the case during pressurization. Next, the pressurizing port valve 1d is closed, the negative pressure port valve 1e is opened, the pressurized air in the capsule 1 is decompressed by the air negative pressure machine connected to the negative pressure air port 1c, and as shown in D to E. To normal pressure (which coincides with the reference position h ₀ of the terminal 4a of the thickness sensor).

Further, from the point E of the normal pressure, the pressure inside the capsule 1 is reduced to below the normal pressure to form negative pressure air 2. This state EF
In G, the internal pressure of the capsule 1 becomes lower than the internal pressure of the case 3, and expansion strain occurs in the case 3. At this time, since the above-mentioned gap S increases, the air in the case leaks out into the capsule and leaks, and the positive (+) strain amount of the case at negative pressure can be measured.

Next, the pressurizing port valve 1d is opened and the negative pressure port valve 1e is opened.
Is closed, pressurized air is flown into the capsule 1 through the pressurized air port 1b, and the negative pressure air in the capsule is returned to the normal pressure as indicated by G to H. By measuring the amount of change in the thickness of the case before and after a series of measurements at normal pressure, it is possible to inspect whether the glass 3b or the back lid 3a is detached from the body 3c.

In addition, in the series of pressurization measurement and negative pressure measurement, the phenomenon shown in Table 1 is taken into consideration for the judgment of the waterproofness due to the inflow and outflow leakage into the case. In addition, the valve is provided with a three-way switching valve at the air flow port 1a, so that the first valve is the pressurizing port valve 1d, the second valve is the negative pressure port valve 1e, and the third valve is the normal pressure valve. The structure may be such that the normal pressure valve is opened when the normal pressure is set.

[0020]

[Table 1]

[0021]

As described above, according to the present invention, in the waterproof inspection device for a timepiece, in addition to the pressurization measurement which causes the compressive strain due to the pressurized air to the case, the negative strain which causes the expansion strain due to the negative pressure air is applied. Since it is configured so that pressure measurement can be performed, it has the effects described below.

Although only the pressurization measurement by the pressurized air may have mistakenly determined that the defective product is a non-defective product in the waterproofness inspection of the case, the negative pressure measurement by the negative pressure air is added to the waterproofness inspection of the case. There is no longer a false decision. After the pressure measurement, the pressure is returned to normal pressure, the negative pressure is measured, the pressure is returned to normal pressure, and then the case is inspected, so that it is possible to measure the quality of adhesion of the glass and the adhesion of the back cover.

[Brief description of drawings]

FIG. 1 is a main cross-sectional view of a timepiece waterproofness inspection device of the present invention.

FIG. 2 is a measurement progress chart showing a strain curve of a case by the inspection device of the present invention.

FIG. 3 is a main sectional view of a conventional watertightness inspection device for a timepiece.

FIG. 4 is a cross-sectional view of a case having a poor waterproof property under normal pressure.

FIG. 5 is a cross-sectional view of a waterproof case having a poor waterproof property.

FIG. 6 is a measurement progress chart showing a distortion curve in a case where a leak amount is small by a conventional waterproof inspection device for a timepiece.

FIG. 7 is a measurement progress chart showing a strain curve of a case during a leak amount by a conventional waterproof inspection device for a timepiece.

[Explanation of symbols]

 1 Capsule 1a Air Circulation Port 1b Pressurized Air Port 1c Negative Pressure Air Port 1d Pressurization Port Valve 1e Negative Pressure Port Valve 2 Negative Pressure Air 3 Clock or Watch Case 4 Thickness Sensor 12 Pressurized Air

Claims (2)

[Claims] 1. A device for inspecting the waterproofness of a watch or a case (hereinafter referred to as a case) of a watch due to air leakage, wherein a capsule serving as a closed tank of the device and an air flow port provided at a predetermined position of the capsule. A pressurized air port and a negative pressure air port communicating with the air flow port, a pressure port valve provided between the air flow port and the pressurized air port, the air flow port and the negative pressure air port And a thickness sensor for measuring the thickness of the case provided inside the capsule, and a watertightness inspection device for a timepiece. 2. The timepiece waterproofness inspection device according to claim 1, wherein (a) at normal pressure, a terminal of the thickness sensor is brought into contact with a thickness measurement position of the case placed in the capsule, A step of determining a reference position of the terminal, and (b) a step of pressure measurement in which pressurized air is flown into the capsule to generate a compressive strain in the case and inspect the waterproofness by pressurization. C) A step of negative pressure measurement in which negative pressure air is flown into the capsule to return it to normal pressure, and then expansion strain is generated in the case to inspect waterproofness due to negative pressure, and (d) the capsule. A method of inspecting waterproofness, which comprises the step of flowing pressurized air into the inside and returning to normal pressure.