JP3512295B2 - Pinhole inspection device - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pinhole inspection device for detecting the presence or absence of pinholes in a hermetically sealed packaging container which is molded from a resin material and is filled with contents.

[0002]

2. Description of the Related Art As shown in FIGS. 10 (A) and 10 (B), a tube container 1 is provided with a flexible tube body 3, and the end of the tube body 3 is subjected to heat welding or ultrasonic bonding. The seam portion 5 is joined by means to form a seam portion 5, and the tip portion of the tube body 3 is provided with a shoulder portion 7, and the upper portion of the shoulder portion 7 is provided with a mouth portion 9. A cap 11 is attached to the mouth portion 9.
Is installed.

By the way, the seam portion 5 may have a defect of poor sealing at the time of joining. For example, in FIG.
As shown in (A), a part of the seam portion 5 is not joined to form a hollow portion 13 and the inside and outside of the tube container 1 communicate with each other, or a joint defect, as shown in FIG. 11 (B). This is a pinhole defect in which the pinhole 15 is formed at the boundary of the portion 5 and the inside and outside of the tube container 1 communicate with each other.

In order to eliminate such defects, for example,
As shown in FIG. 9, the conventional inspection device 17 for a tube container 1 arranges the tube container 1, which is an object to be inspected, between the first electrode 19 and the second electrode 21. An alternating voltage is supplied to the primary coil 25 of the transformer 23, and the boosted alternating voltage generated in the secondary coil 27 via the core 26 is applied to the electrodes 19, 21.
Apply between.

When the tube container 1 is defective, the content of the tube container 1 is regarded as a conductor and the content itself serves as the first electrode 19, and the wall thickness of the tube body 3 is regarded as a dielectric, and the dielectric is used. A capacitor composed of the second electrodes 21 that are in contact with each other is formed. By applying a voltage between the bipolar plates 19 and 21, a current associated with charging flows (hereinafter referred to as a detected current). This detected current flows through the secondary coil 27 and the magnetic flux of the secondary coil 27 changes. Therefore, the magnetic flux in the primary coil 25 also changes and the primary coil 2
Electromagnetic induction occurs at 5 and a new current is generated at the primary coil 25. By detecting this newly generated current with the detection circuit 29, it is possible to find a defect defect in the tube container 1.

[0006]

However, the conventional inspection device for inspecting the current newly generated in the primary coil is as follows.
Even if the detection current flows in the secondary coil, the magnitude of the current newly generated in the primary coil by electromagnetic induction becomes smaller than the magnitude of the detection current flowing in the secondary coil. That is, the number of turns of the primary coil is smaller than that of the secondary coil, and the induced electromotive force is proportional to the number of turns of the coil.

Therefore, the current flowing through the primary coil is a very small current, and this current cannot be detected accurately. The present invention has been made in view of the above problems of the conventional technology, and by detecting the detection current with high accuracy, it is possible to reliably determine the presence or absence of a defect in the hermetically sealed packaging container and improve the productivity. The purpose is to

[0008]

The present invention adopts the following means in order to solve the above problems. The present invention arranges a hermetically-sealed packaging container, which is made of an insulating material and is filled with conductive contents, between electrodes, and a potential difference is provided between the electrodes to inspect a current value flowing in the hermetically-sealed packaging container. In the pinhole inspection device that inspects the sealed packaging container for defects,
A boost rectifier circuit that rectifies the AC voltage after boosting it to a constant voltage value, a smoothing circuit that flattens the boosted and rectified pulsating current voltage, and a sealed packaging container after applying a voltage to the sealed packaging container. A pinhole inspecting device is provided with a detection circuit for detecting a flowing current value (corresponding to claim 1).

An AC voltage boosted to the secondary coil side is converted into a DC voltage through a boost rectifier circuit and a smoothing circuit, and this DC voltage is applied to a hermetically sealed container, and a smoothing circuit and an electrode to which the voltage is applied. By providing a detection circuit for detecting the value of the current flowing through the sealed packaging container between the two, the current flowing through the sealed packaging container can be directly detected.

Further, a voltage adjusting circuit may be provided between the smoothing circuit and the electrode to which the voltage is applied to correct the voltage value output from the smoothing circuit in response to environmental changes (corresponding to claim 2). ).

Since the voltage output from the smoothing circuit via the step-up rectifying circuit changes due to environmental changes (for example, temperature and humidity), the voltage adjusting circuit adjusts the environmental conditions and the voltage value output from the smoothing circuit. The relationship with the quantity is stored, environmental conditions are measured when the sealed packaging container is inspected, and the voltage is corrected based on the measured value. Therefore, a constant voltage can always be applied to the hermetically sealed container.

Further, the detection circuit may be connected with a comparison circuit for comparing the current value detected by the detection circuit with a reference current value for judging the presence or absence of a pinhole in the hermetically sealed container (corresponding to claim 3). ).

A pinhole of the hermetically-sealed packaging container is obtained by storing the detected current when the hermetically-sealed packaging container has a defect as a reference current value in a comparison circuit and comparing the detected current value with the actual detection current value flowing in the hermetically-sealed packaging container. The presence or absence of can be judged. That is, if the detected current value is larger than the reference current value, it is judged as a defective product, and if the detected current value is smaller than the reference current value, it is judged as a good product.

In the comparison circuit, the reference current value may be a current value including the amount of charges charged in the hermetically sealed container (corresponding to claim 4). By measuring the amount of charge attached to the hermetically sealed container and correcting the reference current value based on the measured value, the detected current can be measured when there is no amount of electric charge attached to the hermetically sealed container. Therefore, it is possible to accurately determine the defect of the hermetically sealed packaging container.

In the comparison circuit, the current value detected by the detection circuit per unit time may be compared with the magnitude of the current value detected by the detection circuit per unit time of a defective product in the sealed packaging container. Corresponding to).

In the comparison circuit, the integrated value of the current value detected by the detection circuit with respect to time may be compared with the magnitude of the integrated value of the current value detected by the detection circuit of the defective sealed packaging container with respect to time. (Corresponding to claim 6).

Even if the detected current exceeds the reference current value even temporarily, it is not appropriate to judge that the product is defective. Therefore, the magnitude of the current value with respect to the time of the detected current and the integrated value of the current value with respect to the unit time of the detected current are sealed. By comparing the detected current value with respect to time of the defective product of the packaging container and the integrated value of the detected current with respect to the unit time, it is possible to prevent the determination of the defective product due to a minute current change. <Inspection Object of the Present Invention> The sealed packaging container to be inspected is
For example, contents having conductivity inside (for example, cosmetics,
It is a sealed packaging container in which the contents are enclosed in a tube container filled with toothpaste, food, etc. or a container formed of resin such as polyethylene.

[0018]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to FIG.
From now on, the description will be made with reference to the drawing of FIG. The structure of the tube container 1 to be inspected is the same as that of the conventional one already described, and the description thereof will be omitted. However, in the inspection device of the present invention, from the principle, the tube body 3 and the cap 1
1 is formed of an insulating material (for example, resin), and has a conductive content inside (for example, cosmetics,
The tube container 1 filled with toothpaste, food, etc. is to be inspected. [First Embodiment] FIG. 1 shows a pinhole inspection apparatus (hereinafter referred to as an inspection apparatus) 30 according to the present invention. The inspection device 30 uses a sine wave voltage source 31 as a power supply voltage,
It has a transformer 33 that boosts the voltage of the voltage source 31. The transformer 33 is connected in series with a boost rectifier circuit 35 that further boosts and rectifies the boosted AC voltage. The step-up rectifier circuit 35 uses, for example, a voltage doubler rectifier circuit including a diode and a capacitor.

The step-up rectifier circuit 35 is connected in series with a smoothing circuit 37 for converting the boosted and rectified AC voltage into a DC voltage. The smoothing circuit 37 is composed of a filter and the like. Since the voltage output from the smoothing circuit 37 changes due to environmental changes (for example, temperature and humidity), the relationship between the environmental conditions and the correction amount of the voltage value output from the smoothing circuit 37 is stored and stored in a tube container. 1 is connected in series with a voltage adjusting circuit 39 that measures the environmental conditions when inspecting 1 and corrects the voltage based on the measured value. The voltage adjusting circuit 39 includes a sensor 41 for measuring environmental changes (for example, temperature, humidity, charge amount), and a voltage adjusting circuit 3 for the tube container 1.
It is connected with the 1st electrode 43 which applies the voltage output from 9.

The first electrode 43 is provided with a second electrode 45 at a portion facing each other with the tube container 1 which is an object to be inspected in between. This second electrode 45 is grounded. First
A detection circuit 47 for detecting a detection current flowing in the tube container 1 is provided in parallel on a path connecting the electrode 43 and the second electrode 45. This detection circuit 47 detects the detection current and the tube container 1 when the tube container 1 has a pinhole 15.
It is connected in series with a comparison circuit 49 that compares the magnitude of a detection current (hereinafter, referred to as a reference current) flowing inside.

The transformer 33 is composed of a primary winding 51, a secondary winding 53 and a core. The number of turns n1 of the primary winding 51 is smaller than the number of turns n2 of the secondary winding 53. Therefore, 2
The voltage output from the secondary winding 53 is boosted in proportion to the number of turns n2 of the secondary winding 53.

FIG. 2 shows the voltage source 31, the transformer 33,
The circuit diagram which mounted the boost rectification circuit 35 and the smoothing circuit 37 is shown. In the figure, A indicates the boost rectification circuit 35 and the smoothing circuit 37, and B indicates the place where the detection current flowing in the tube container 1 is sent to the detection circuit 47. <Operation of Inspection Device 30> Next, the operation of the inspection device 30 will be described with reference to FIGS. 1 to 7.

In order to inspect the seam portion 5 of the tube container 1 for a defect, the tube container 1 is first moved by a transfer mechanism, for example.
It is conveyed between the electrode 43 and the second electrode 45. Current source 31
To supply a sinusoidal current to the primary winding 51 to excite the core 55. The magnetic flux penetrating the core 55 also penetrates the inside of the secondary winding 53, and electromotive force is generated in the secondary winding 53 by electromagnetic induction. This electromotive force is boosted in proportion to the coil turn ratio (n2 / n1). The boosted AC voltage is boosted and rectified by a large number of diodes and capacitors provided in the boost rectifier circuit 35.

The boosted and rectified voltage is converted into a DC voltage by a smoothing circuit 37 as shown in FIG. 1, and this DC voltage is sent to a voltage adjusting circuit 39. The voltage adjusting circuit 39 stores, for example, the relationship between the ambient temperature of the tube container 1 to be inspected and the set voltage to be applied to the tube container 1, in the memory, and based on the temperature data from the sensor 41, The difference with the data is obtained, and the voltage of the difference is increased or decreased. Therefore, the voltage output from the voltage adjusting circuit 39 can always be the same as the set voltage.

The voltage output from the voltage adjusting circuit 39 is
It is applied to the first electrode 43. The first electrode 43 acts as a positive electrode and the second electrode 45 acts as a negative electrode to charge this capacitor. The current flowing during this charging is detected by the detection circuit 47, and the detected current is sent to the comparison circuit 49.

In this comparison circuit 49, as shown in FIGS. 3 and 4, a reference current value Is for determining that the tube container 1 is defective is set, and the detected current Io is larger than the reference current value Is. If it is small, it is judged to be defective, and if it is small, it is judged to be good.

However, the detected current Io is not always a constant current value over time, but changes due to the difference in conductivity of the contents in the tube container 1 and the presence of foreign matter. Therefore, in a short time, the detected current may exceed the reference current value Is. In such a case, it is not appropriate to judge the defective product if the detected current exceeds the reference current value Is even temporarily.

Therefore, as shown in FIG. 5, the current value of the detected current with respect to time (hereinafter referred to as the current differential value) df.
(T) / dt is calculated, and the magnitude is compared with a current differential value (hereinafter referred to as a reference current differential value) that should be a defective product. If the current differential value is larger than the reference current differential value, it is determined as a defective product. However, if it is small, it can be judged as a good product. However, since the detected current changes periodically within a unit time, for example, the current change of only a frequency of 500 Hz or less is judged, and the frequency of 5
Current changes above 00 Hz are ignored.

Further, as shown in FIG. 6, the integrated value of the current value with respect to the time of the detected current (hereinafter referred to as the integrated current value).
S is calculated, and the magnitude is compared with a current integral value (hereinafter referred to as a reference current integral value) that should be a defective product. If the current integral value is larger than the reference current integral value, it is determined as a defective product, and conversely. If it is small, it can be judged as a good product. Here, if the method of taking the time can be arbitrarily changed, it is possible to ignore the ultra-fine high-frequency change in the detected current.

Further, as shown in FIG. 7, when a high voltage is generated, a minute current flows around the electrodes 43 and 45, and the air is charged (δ). Therefore, if the tube container 1 as a dielectric is installed between the electrodes 43 and 45, the tube container 1 itself is charged (α), although it changes depending on the environmental conditions. Therefore, when the tube container 1 has a defect, when a voltage is applied to the tube container 1, the charge (α) attached to the surface of the tube container 1 also flows, and the detected current is when the tube container 1 itself is not charged. It is a large value compared to.

Therefore, if the charge amount (α) attached to the tube container 1 is measured and the initial reference current value Is is corrected based on the measured value and the corrected reference current value Is is used, It is possible to measure the detected current when there is no amount of charge attached to the. [Second Embodiment] As shown in FIG. 8, the second embodiment is different from the first embodiment in that a voltage adjusting circuit 39 and a comparing circuit 49 are omitted.

In the second embodiment, the DC voltage output from the smoothing circuit 49 is directly applied to the first electrode 43, and the detection current flowing in the tube container 1 is detected by the detection circuit 47.

This is useful when the tube container 1 to be inspected is inspected in a place where the environmental conditions are always constant or when it is desired to downsize the inspection device 30. The voltage adjusting circuit 3
9 and the comparison circuit 49 can obtain the same effect as that of the first embodiment by connecting a PC or the like from the outside of the inspection device 30.

[0034]

As described above, according to the present invention,
By providing the step-up rectifier circuit, the smoothing circuit, and the detection circuit, the current flowing in the sealed packaging container can be directly detected, so that the presence or absence of a defect in the sealed packaging container can be accurately determined.

[Brief description of drawings]

FIG. 1 is a block diagram of a pinhole inspection device according to a first embodiment of the present invention.

FIG. 2 is a mounting diagram of a boost rectifier circuit and a smoothing circuit according to the first embodiment of the present invention.

FIG. 3 is an explanatory diagram illustrating comparison determination of a comparison circuit according to the first embodiment of the present invention.

FIG. 4 is an explanatory diagram illustrating a determination of comparison by a comparison circuit according to the first embodiment of the present invention.

FIG. 5 is an explanatory diagram illustrating a comparison determination in the comparison circuit according to the first embodiment of the present invention.

FIG. 6 is an explanatory diagram illustrating a comparison determination in the comparison circuit according to the first embodiment of the present invention.

FIG. 7 is an explanatory diagram illustrating a reference current value of a comparison circuit according to the first embodiment of the present invention.

FIG. 8 is a block diagram of a pinhole inspection device according to a second embodiment of the present invention.

FIG. 9 is a block diagram showing a conventional technique.

FIG. 10 (A) is a front view of a tube container,
(B) is the same side view

FIG. 11 (A) is a front view of a main part showing a defective bonding defect in a seam portion, and FIG. 11 (B) is a front view of a main part showing a pinhole defect.

[Explanation of symbols]

1 Tube container (sealed packaging container) 19,43 First electrode 21,45 Second electrode 30 pinhole inspection system 35 Step-up rectifier circuit 37 Smoothing circuit 39 Voltage adjustment circuit 47 detection circuit 49 Comparison circuit

─────────────────────────────────────────────────── --- Continuation of the front page (72) Inventor Kazuhiro Yagi 6-48 Yayoi-cho, Shizuoka-shi, Shizuoka Pola Kasei Kogyo Co., Ltd. (72) Ryohei Sagisaka 6-48, Yayoi-cho, Shizuoka-shi, Shizuoka Prefecture Incorporated (72) Inventor Kintoshi Yamaguchi 6-48 Yayoi-cho, Shizuoka-shi, Shizuoka Pola Kasei Kogyo Co., Ltd. JP, A) JP 63-253205 (JP, A) JP 62-276444 (JP, A) JP 63-294334 (JP, A) JP 5-187805 (JP, A) (58) ) Fields surveyed (Int.Cl. ⁷ , DB name) B65B 51/10 B65B 57/02

Claims (6)

(57) [Claims] 1. A sealed packaging container made of an insulating material and having a conductive content filled inside is disposed between electrodes, and a potential difference is provided between the electrodes to inspect a current value flowing in the sealed packaging container. In a pinhole inspection device that inspects sealed packaging containers for defects, (a) boost rectifier circuit that rectifies the AC voltage after boosting it to a certain voltage value, and (b) boosted and rectified pulsating voltage. A pinhole inspection device, comprising: a smoothing circuit for flattening the above, and (c) a detection circuit for detecting a current value flowing in the hermetically-sealed packaging container after applying a voltage to the hermetically-sealed packaging container. 2. A voltage adjusting circuit for correcting the voltage value output from the smoothing circuit in response to environmental changes is provided between the smoothing circuit and the electrode to which the voltage is applied. Pinhole inspection device described. 3. The detection circuit is provided with a comparison circuit connected thereto for comparing a current value detected by the detection circuit with a reference current value for determining the presence or absence of a pinhole in the sealed packaging container. The pinhole inspection device according to any one of claims 1 and 2. 4. The pinhole according to claim 1, wherein in the comparison circuit, the reference current value is a current value including a charge amount charged in a hermetically sealed container. Inspection device. 5. The comparison circuit compares the current value detected by the detection circuit for a unit time with the magnitude of the current value detected by the detection circuit for a unit time of a defective product in the sealed packaging container. The pinhole inspection device according to any one of claims 1 to 3. 6. The comparison circuit compares the integrated value of the current value detected by the detection circuit with respect to time with the magnitude of the integrated value of the current value detected by the detection circuit of the defective product in the sealed packaging container with respect to time. The pinhole inspection device according to any one of claims 1 to 3.