JPS6315537B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention solves the problem of pinholes and cracks in ceramic containers.
This invention relates to a method for inspecting liquid leakage due to cracks, etc.

Conventionally, defects such as relatively large pinholes, cracks, and chips in ceramic wares such as vases and ornaments can be inspected visually or by sound, and such inspections have been sufficient to ensure that the pottery retains its functionality.

However, when used as a container for liquids with low surface tension, such as alcohol, even the smallest pinholes, cracks, or chips can cause liquid to leak, making it impossible to use the container as a container. Such minute pinholes cannot be inspected at the time the container is manufactured using conventional inspection methods.
Therefore, before filling, a time-consuming and expensive method has been adopted in which a liquid with low surface tension is filled and heated for a long period of time to check for leakage.

The present invention provides an inspection method that can safely, easily, reliably and efficiently detect minute pinholes and the like as described above.

That is, the present invention involves filling the inside of a ceramic container to be inspected with water or an aqueous electrolyte solution, inserting a rod-shaped electrode that penetrates an insulating plug and reaching the water or aqueous electrolyte solution inside the container, and then Place the container in water or an aqueous electrolyte solution in an insulated water tank.
Submerge the bottle up to the neck, and then submerge the electrode in the water or electrolyte aqueous solution in the tank to create a connection between the rod-shaped electrode in the ceramic container and the electrode in the tank, which has an insulating strength higher than that of air, and the insulating strength of the ceramic is higher than that of air. A lower voltage is applied to detect the voltage drop due to dielectric breakdown of the air in the microscopic gap that penetrates from the inside of the ceramic container to the outside. This is a method of pre-inspecting for liquid leakage caused by through-holes after filling.

In order to facilitate understanding of this method, the method will be explained below using drawings. FIG. 1 is a schematic vertical cross-sectional view of an inspection device showing an embodiment of the present invention.

In FIG. 1, a ceramic container 1, which is a test specimen, is placed in an insulating water tank 2 made of polyethylene or the like filled with water or an aqueous solution of a salt such as common salt; A rod-shaped electrode 3a is inserted into the opening of 1 through an insulating plug made of rubber or the like. Further, on the outside of the container 1, a ring-shaped electrode 5 as an external electrode 4a is attached to a support 6 so as to be movable up and down along the circumferential surface of the container, and a voltage load meter 7 with a built-in voltage display meter is connected to the container's internal and external electrode terminals. It is connected to the. When a suitable voltage, for example 8 to 9 KV, is applied to both electrodes from the voltage load meter 7, if there are pinholes in the test specimen container 1, dielectric breakdown of the air present in the pinholes will occur and the voltage will drop. do. By reading this change in voltage, it is possible to determine whether the container 1 is good or bad. If a high voltage is applied during this operation, the device should be placed on an insulating plate 8 made of rubber or the like, and an isolation lid 10 that can be opened and closed vertically by a motor 9 should be provided on the top of the water tank 2. In order to ensure safety, it is desirable to detect the opening/closing state of the voltage load meter 10 with a limit switch (not shown) and to turn on/off the voltage load meter 7.

As described above, the present invention utilizes the voltage drop caused by the dielectric breakdown of the air present in pinholes, etc., and can detect liquid leakage very easily, reliably, and efficiently. Furthermore, since the inside and outside of the container are in contact with water or an aqueous salt solution, measurements can be made regardless of the external or internal shape of the container, and cleaning after inspection can be easily performed. Although this method requires electric current for inspection, it can be operated extremely safely by using one or more limit switches and by surrounding the device with an insulating shield.

Example 1 Using the device shown in Figure 1, a ceramic liquor bottle (capacity
700-800ml, outer diameter 110mm, height 160mm) was tested for liquid leakage. Polyethylene water tank 2 (diameter 250mm,
When the above bottle 1 is immersed in the water (height 160 mm), the water depth is 50 mm.
Add tap water to a depth of ~60mm. A low-frequency high-voltage pulse discharge type pinhole tester (commercially available) is used as the instrument 7, and a ring-shaped electrode 5 (a ring-shaped copper wire with a diameter of 2.0 mm and a ring with a diameter of 130 mm) connected to the electrode side terminal is placed in the water tank 2. Submerge it so that 5 is below 1. On the other hand, pour 600 to 650 ml of tap water into a good-quality Western liquor bottle 1 with no liquid leakage, dip it into the water tank 2, and connect the electrode 3a (diameter 3
mm, length 160 mm) from the mouth of the bottle. Lid 10
After turning on the opening/closing motor 9 and closing the lid, turn on the meter and set the indicated voltage to 8.7KV as the test voltage. Next, fill water in the sample liquor bottle for testing in the same manner as described above, and
Insert it, apply voltage in the same way, and read the voltage indicated by the meter. Those with an indicated voltage of 6.0 to 6.5 KV will not leak when exposed to water, but if you put whiskey in the bottle and leave it for more than a day or night, a slight leakage of the contents was confirmed. on the other hand
There was no whiskey leakage in all cases over 7.0KV. Also, those below 5.5KV showed leakage even with water.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram showing an embodiment of the method of the present invention. 1 is a container, 2 is a water tank, 3a, 4a and 5 are electrodes, and 7 is a meter.

Claims (1)

[Claims] 1 Fill the inside of a ceramic container to be inspected with water or an aqueous electrolyte solution, insert a rod-shaped electrode that penetrates the insulating stopper and reaches the water or aqueous electrolyte solution inside the container, and then insulate the ceramic container. Submerge the bottle up to the neck in the water or electrolyte solution in the aquarium,
Furthermore, the electrode is submerged in the water or electrolyte aqueous solution in the tank, and a voltage higher than the dielectric strength of air but lower than the dielectric strength of the ceramic is applied between the rod-shaped electrode of the ceramic container and the electrode in the tank. , detects the voltage drop due to dielectric breakdown of the air in the minute gap that penetrates from the inside of the ceramic container to the outside, and detects the voltage drop due to the dielectric breakdown of the air in the minute gap that penetrates from the inside of the ceramic container to the outside. A method of pre-inspecting for liquid leakage after filling.