JPH087108B2 - Container airtightness measuring method and apparatus and container conveying method - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and apparatus for measuring the airtightness of a sealed container.

[0002]

2. Description of the Related Art For example, in a storage container for medicines, foods, etc., it is extremely important in the manufacturing process to inspect for defects such as pinholes, etc. in order to prevent external contamination and leakage of contents during storage. It is a process. Particularly in pharmaceutical vial bottles, ampoules and the like, it is necessary to inspect even minute pinholes having a diameter of several mμ or less in order to prevent bacteria and the like from entering with the atmosphere. Therefore, conventionally, as a method for detecting an extremely small pinhole, as described in JP-A-45-77179 and JP-A-55-124533, an electrode is brought into close contact with the outer peripheral surface or the bottom surface of the container to be inspected. A method and apparatus for detecting a defect from a current value flowing between both electrodes by applying a high voltage to both electrodes have been proposed. However, with this method and device, even minute pinholes can be detected, but since the dielectric constant between the electrodes is low, it is not possible to obtain high accuracy, and all minute pinholes can be detected. I can't expect results. Therefore, the present inventor proposes to solve the above-mentioned drawbacks in the previous application by interposing a fluid having a high dielectric constant between the electrode and the container to be inspected and arranging a container having no defect between the electrodes. By comparing the differences, a container airtightness measuring method for detecting a container defect and an apparatus thereof have been developed (Japanese Patent Publication No. 2-17071).

Further, as shown in FIG. 9, a method in which a screw and a star wheel are combined is used to convey the container to be inspected in the inspection process.

[0004]

Although the above method can detect extremely small pinholes as described above, it has a problem in accuracy. Further, although the method and the apparatus are excellent in accuracy, it is time-consuming and troublesome because it is necessary to compare with the sensitivity of a container having no defect. Therefore, it is difficult to measure a large number of containers with high accuracy in any of the above methods or apparatuses. Further, in the conventional conveying method, there is a possibility that the object to be inspected may be damaged by the screw or the star wheel, and it is unsuitable especially for those made of thin glass such as ampoule.

[0005]

SUMMARY OF THE INVENTION The present invention provides a method and apparatus for easily detecting extremely small pinholes having a diameter of several mμ or less with high accuracy and enabling continuous measurement. Is. That is, the method includes a grid-shaped inner cylinder having a diameter larger than that of the container to be inspected and formed of a conductive material, and a grid-shaped inner cylinder having a diameter larger than that of the inner cylinder and formed of a conductive material. An outer cylinder having a diameter larger than that of the middle cylinder and formed of a conductive material, and an oversized cylinder formed of a heat-resistant insulator having a diameter larger than that of the outer cylinder are coaxially overlapped with each other, and the outer peripheral surface of the oversized cylinder is By immersing the detector provided with a heater in a highly insulating fluid and applying a cathode voltage to the inner cylinder and the middle cylinder and an anode voltage to the outer cylinder, or the inner cylinder and the middle cylinder. By applying an anode voltage to the outer cylinder and a cathode voltage to the outer cylinder, the fluid in the container to be inspected interposed in the inner cylinder is ionized, and the capacitance between the outer cylinder, the middle cylinder, and the inner cylinder is increased. And the ion current flowing out from the defective portion of the container to be inspected that is present in the inner cylinder. The detection circuit connected to the detector is to detect the defect of the inspection container.

Further, the apparatus includes an inner cylinder formed of a conductive material and capable of interposing a container to be inspected, a middle cylinder formed of a conductive material and having a diameter larger than that of the inner cylinder, and a middle cylinder formed of the middle cylinder. An outer cylinder having a large diameter and formed of a conductive material and an oversized cylinder formed of a heat-resistant insulator having a larger diameter than the outer cylinder are superposed coaxially, and a heater is provided on the outer peripheral surface of the oversized cylinder. The detector configured as described above is immersed in a highly insulating fluid, and a voltage supply circuit and an ion current detection circuit are connected to the detector.

Further, the present invention provides a method capable of eliminating the drawbacks of the conventional method of transporting an inspected container. That is, the method means that the container to be inspected passes through the carry-out side of the detector of the airtightness measuring apparatus according to claim 1, which is provided in the carry-in tank for carrying in the container to be inspected, and the carry-out tank filled with the fluid. In addition to connecting with a possible transport pipe, the carry-in tank and the carry-out tank are connected with a water supply pipe, and the fluid is circulated in the transport pipe from the carry-in tank to the carry-out tank, thereby carrying out the container to be inspected from the carry-in tank. It is to transfer to the tank.

[0008]

[Function] The inspected container filled with the highly insulating fluid is
The molecular motion of the fluid becomes active by being heated by the heater provided on the outer peripheral surface of the oversized cylinder. When the container to be inspected is placed in an electric field formed by an inner cylinder to which a voltage is applied, the fluid is ionized, and the ionized ions appear on the inner surface of the fluid. Further, since electrostatic capacitance is generated around the middle cylinder and the outer cylinder due to the applied voltage, if there is a defect such as a pinhole in the DUT, the ions appear around the inner cylinder. It is attracted by ions having a polarity opposite to that of, and flows out from the defect part together with active molecular motion and reaches the inner cylinder. Then, the potential of the inner cylinder with respect to the outer cylinder increases by the amount of the ions that have reached the inner cylinder, and the surplus ions flow into the middle cylinder as an ion current. Therefore, by connecting the ion current detection circuit to the middle cylinder, it is possible to measure the presence / absence and magnitude of the ion current, that is, the presence / absence and magnitude of the defective portion.

Next, in the method of transporting the container to be inspected according to the third aspect, the container to be inspected is transported by the fluid circulating in the transport pipe that connects the carry-out tank and the carry-in tank, and is not damaged.

[0010]

1 to 6 are explanatory views of a container airtightness measuring apparatus according to the present invention. Hereinafter, the present invention will be described in detail with reference to these drawings. Reference numeral 1 is a detector for detecting defects in an object to be inspected, which has a quadruple cylindrical structure with a common central axis and is spaced at regular intervals. A cathode K as a cylinder, a grid G as a middle cylinder, a plate P as an outer cylinder, an oversized cylinder L, and a heater H are arranged, and the cathode K, grid G,
The plate P is made of a conductive material, the extra large cylinder L is made of a heat-resistant insulating material, and the cathode K and the grid G are formed in a mesh shape. The measuring circuit 3 is connected to the cathode K, the grid G, and the plate P, and the heater circuit 6 is connected to the heater H. Reference numeral 4 is a trumpet portion for guiding the ampoule 2 as the container to be inspected into the detector, and reference numeral 5 is a brush for eliminating residual ions in the ampoule through the grid G by contacting the ampoule. 7
Indicates a transport pipe for transporting the ampoule that has been inspected. The detector 1 is installed in a state of being immersed in a pure water tank 8 filled with highly insulating distilled water (hereinafter referred to as pure water) 9, and an ampoule 2 passes through the cathode K. . FIG. 2 shows an embodiment of the measuring circuit 3, in which a cathode D is provided with a diode D1 and a resistor R1, a plate P is provided with a diode D3 and a resistor R3, and a grid G is provided with an ammeter A1 via a resistor R2, , Ammeters A2 are respectively connected via the amplifier 11. Further, the AC power supply 10 is connected via the transformer T1 so that the DC power supply can be supplied. FIG. 3 is an explanatory diagram of the heater circuit, to which the AC power source 10 is connected via the heater transformer T2.

Next, a case will be described in which the apparatus is actually used to measure the airtightness of an ampoule in which a gas or a chemical solution (hereinafter referred to as an enclosure) is enclosed. Now, a constant cathode voltage is applied to the cathode K and the grid G, and a constant anode voltage is applied to the plate P. As shown in FIG.
It is assumed that the ampoule 2 as the object to be inspected is carried in via the trumpet part 4 in a state where the pure water 9 around each of the grid G and the plate P is charged. First, when the ampoule 2 comes into contact with the brush 5, residual ions inside are lost through the grid G. Then, when the ampoule is positioned inside the cathode K that constitutes the detector 1, the enclosure 19 in the ampoule is heated to a predetermined temperature by the heater H, the molecular activity becomes active, and a high insulating property is achieved. Then, the ampoule 2 is placed in an electric field due to the cathode voltage applied to the cathode K, and ions of the ionized ionized inclusions are generated in the ampoule 2. Here, as shown in FIG. 5, when the pinhole 20 is present in the ampoule 2, the ions of the inclusions are combined with the active molecular motion to cause the cathode K.
Since it is generated in the vicinity of, the ions having the opposite polarity to the ions of the inclusion are attracted and flow out from the pinhole 20. Then, the potential of the cathode K with respect to the plate P becomes higher by the amount of the ions attracted to the cathode K,
The surplus ions move to the grid G. This grid G
The ions flowing to become an ion current, which is detected by the ammeter A1 via the resistor R2 connected to the grid G. The detected ionic current is amplified by the amplifier 11 and detected by the ammeter A2. Therefore, the existence and size of the pinhole can be determined from the measurement value of the ammeter A2.

Incidentally, the cathode K, the grid G, and the plate P
When an AC voltage is applied to and, ions of ionized ionized gas or chemical liquid are generated in the ampoule 2, and the pure water 9 around the cathode K, the grid G, and the plate P is generated.
Are ionized and ionized, the ions of the ionized gas or chemical solution are attracted to the ions generated around the cathode K, flow out from the pinhole 20, and are detected by the ammeter A1 as described above.

Next, a method of transporting the container to be inspected according to the present invention will be described with reference to FIGS. In FIG. 7, 13 is an ampoule 2 carried out from the carry-in tank 12 via the transport pipe 7.
Is a carry-out tank for carrying in and leaving it floating, and like the carry-in tank, is filled with pure water. Further, the carry-in tank 12 and the carry-out tank 13 are connected by a water supply pipe 14, and the pump 1 in the carry-out tank is connected.
By sending the pure water in the carry-in tank into the carry-in tank 12 by 9, the pure water is circulated from the carry-out tank 12 toward the carry-in tank 13, and the ampoule 2 in the carry-in tank 13 is carried out through the transport pipe 7. It is supposed to be sent to 13. 16 is unloading tank 1
It is a conveyor for picking up the ampoule floating in 3 and transporting it to a predetermined place. 8 and 9 are explanatory views when a large-sized carry-in tank 15 provided with a plurality of detectors is installed. Each detector is installed by each chemical manufacturer, and when each ampoule is inspected by the measuring instrument for the presence of defects such as pinholes, it is sent to each unloading tank through each transport pipe. As described above, since the present transport method uses the fluid, it is possible to transport the test object without damaging it, and it is possible to continuously test various kinds of test objects.

[0014]

According to the present invention, not to mention defects such as very small pinholes having a diameter of several mμ or less,
All ions can be detected as long as the ions can pass therethrough. In addition, since it is not necessary to compare with the airtightness of a container having no defect, it is possible to measure instantaneously. In addition, regardless of whether the container to be inspected is an insulating material or a non-insulating material, as long as it is a closed container, iron, glass, plastic, or any other material can be measured, and ions can be ionized in the container. Or contains a substance capable of generating ions by an electric field, its contents are gas, liquid,
Even if it is a solid or the like, or if the gap in the container is filled with vacuum or air, it can be inspected without any problem. Further, by using the carrying method of the present invention, defects of the container can be continuously detected and the container is not damaged. INDUSTRIAL APPLICABILITY As described above, the present invention makes it possible to significantly reduce the inspection process time of a product using a container and dramatically improve the accuracy of inspection, and to achieve an improvement in product quality and a reduction in manufacturing cost. It is a target.

[Brief description of drawings]

FIG. 1 is an explanatory diagram of a container airtightness measuring method and apparatus according to the present invention.

FIG. 2 is an explanatory diagram of a measurement circuit.

FIG. 3 is an explanatory diagram of a heater circuit.

FIG. 4 is an explanatory diagram of a detector.

FIG. 5 is an explanatory diagram of a detector and a measurement circuit.

6A and 6B are a cross-sectional explanatory view of a detector and a vertical cross-sectional explanatory view showing a generation state of ions.

FIG. 7 is an explanatory diagram of a container transport method according to the present invention.

FIG. 8 is an explanatory diagram of a method of transporting a container according to the present invention using a large loading tank.

FIG. 9 is an explanatory diagram of a method of transporting a container according to the present invention using a large loading tank.

FIG. 10 is an explanatory view showing a conventional container transport method.

[Explanation of symbols]

1 ... Detector, 2 ... Ampule, 3 ... Measuring circuit, 4 ...
・ Trumpet part, 5 ・ ・ Brush, 6 ・ ・ Heater circuit, 7 ・
・ Transport pipe, 8 ・ ・ Pure water tank, 9 ・ ・ Pure water, 10 ・ ・ AC power supply, 11 ・ ・ Amplifier, 12 ・ ・ Inlet tank, 13 ・ ・ Unload tank, 14 ・ ・ Water pipe, 15 ・ ・ Large-size carry-in Tank, 16 ・ ・ Conveyor, 17 ・ ・ Screw, 18 ・ ・ Star wheel, 19 ・ ・ Pump, M ・ ・ motor, P ・ ・ plate, G ・ ・ Grid, K ・ ・ Cathode, L ・ ・ Oversized cylinder,
D1, D2, D3 ... Diode, R1, R2, R3 ...
・ Resistance, A1, A2 ・ ・ Ammeter, H ・ ・ Heater, H
1, H2 ... Terminal, T1 ... transformer, T2 ... heater transformer.

Claims (3)

[Claims] 1. A lattice-shaped inner cylinder having a diameter larger than that of the container to be inspected and formed of a conductive material, a lattice-shaped middle cylinder having a diameter larger than that of the inner cylinder and formed of a conductive material, and the middle cylinder. An outer cylinder having a larger diameter and formed of a conductive material and an oversized cylinder formed of a heat-resistant insulator having a larger diameter than the outer cylinder are coaxially overlapped, and a heater is provided on the outer peripheral surface of the oversized cylinder. By immersing the detector provided and configured in a highly insulating fluid and applying a cathode voltage to the inner cylinder and the middle cylinder and an anode voltage to the outer cylinder, or by applying an anode to the inner cylinder and the middle cylinder. By applying a voltage to the outer cylinder, a cathode voltage is applied to ionize the fluid in the container to be inspected interposed in the inner cylinder and to form a capacitance between the outer cylinder, the middle cylinder, and the inner cylinder. Then
A method for measuring the airtightness of a container, wherein a defect of the container to be inspected is detected by a detection circuit connected to the detector for an ion current flowing out from a defective portion of the container to be inspected interposed in the inner cylinder. 2. An inner cylinder made of an electrically conductive material, capable of interposing a container to be inspected, a middle cylinder made of a conductive material and having a diameter larger than that of the inner cylinder, and an electrically conductive material having a diameter larger than that of the middle cylinder. An outer cylinder formed of a material and an oversized cylinder formed of a heat-resistant insulator having a diameter larger than that of the outer cylinder are superposed coaxially, and a heater is provided on the outer peripheral surface of the oversized cylinder. A container airtightness measuring apparatus, characterized in that the container is immersed in a highly insulating fluid, and a voltage supply circuit and an ion current detection circuit are connected to the detector. 3. The container to be inspected can pass through a carry-out side of a detector of the airtightness measuring apparatus according to claim 1, which is provided in a carry-in tank for carrying in the container to be inspected, and a carry-out tank filled with the fluid. The container to be inspected from the carry-in tank to the carry-out tank by connecting the carry-in tank and the carry-out tank with a water supply pipe and circulating the fluid in the transport pipe from the carry-in tank to the carry-out tank. A method of transporting a container to be inspected, which comprises transporting.