JP2003042993A - Inner surface coating inspection device of metal vessel - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an inner surface coating inspection device of a metal vessel, capable of improving inspection reliability of the inspection device and quality assurance of the inspected metal vessel, regardless of the shape of the inner surface of the metal vessel. SOLUTION: This inner surface coating inspection device 2 of the metal vessel 1 for inspecting the inner surface coating 4 of the metal vessel 1, having the non-conductive inner surface coating 4 applied thereto, is equipped with an application device for applying an arbitrary voltage by using a metal part 3 of the metal vessel 1 as one polarity and a conductive member 19, arranged in the metal vessel 1 as the reverse polarity, an inspection water supply device for filling the metal vessel with an inspection water 17 having electrochemical properties necessary for inspection, an inner surface coating defect determination means for determining defects on the inner surface coating based on a current detected, when the inspection water 17 is filled and the voltage by the application device is applied, and a detected current monitoring device for discriminating the detection state pattern of the current and determining the inspection operation of the inspection device 2.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a metal container made of a surface-treated steel plate, an aluminum alloy plate or the like, and in particular, an inner surface covering the inner surface side of a metal container having both ends opened and one of which has a small diameter. The present invention relates to an inner surface coating film inspection apparatus that detects defects such as scratches, cracks, and pinholes that occur in a coating film.

[0002]

2. Description of the Related Art In order to prevent the metal container from being corroded by its filling, the inner surface of the metal container is covered with an insulator made of synthetic resin such as a thermosetting resin coating film or a thermoplastic resin film film. It has been widely performed in the past.
The material and thickness of the coating applied to the inner surface of the body of the metal container and the method of forming the coating are determined according to the properties of the filling material of the metal container. The thickness of the coating is usually 4 μm to 13 μm in the case of a thermosetting coating film, and 10 μm to 30 μm in the case of a thermoplastic resin film film.

However, defects such as scratches, cracks, and pinholes sometimes occur in the inner surface coating during the formation of the inner surface coating and in the subsequent processing step of the body part of the metal container. Then, if the filler is sealed inside the metal container while leaving the defects of the inner surface coating, the metal constituting the body part of the metal container is corroded by the filler and a corrosion hole is generated, or the body part of the metal container is corroded. There is a possibility that the metal used in the above may be eluted in the filling material to impair the flavor of the filling material. Therefore, in the process before filling the filling material into the metal container, a defect of the inner surface coating film is detected by a sampling inspection.

As a method for detecting defects on the inner surface coating film (coating film) of the metal container, the enamellator method is generally known. The enamellator method will be described. First, the electrolytic solution is injected into a metal container having one end closed and the other end opened, and the negative electrode of the detection device is immersed therein. Next, the positive electrode of the detection device is brought into contact with the exposed metal portion of the metal container, and a voltage of about several volts (eg, 6 V) is applied between these electrodes for a predetermined time (eg, 3 seconds). Then, the defect of the inner coating is detected by measuring the current flowing by applying a voltage of about several volts.

However, in the enamellator method, since an aqueous solution of sodium chloride or an aqueous solution of sodium sulfate is used as the electrolytic solution, it is a metal container with a one-end opening for which the inspection result that there is no defect in the inner coating is obtained. However, the electrolytic solution adhering to the inner surface of the metal container may corrode the inner surface of the metal container with the lapse of time thereafter. Therefore, the metal container used for the inspection is discarded, and a sampling inspection is a prerequisite. Therefore, if this method is adopted for 100% inspection of metal containers with one-end opening, a cleaning process is required to completely remove the highly corrosive electrolytic solution from the inside of the metal container, which complicates the process. There is a problem that the manufacturing cost of the container increases.

[0006] Japanese Patent Laid-Open No. 2000-046776 discloses an example of a method and apparatus for detecting defects in the inner surface coating of a metal container having one end opening which can deal with such a problem. In this publication, a conductive brush is inserted into the inside of a metal container to bring it into contact with the inner surface coating, and a conductive liquid is supplied to the surface of the inner surface coating to rotate the brush and the metal container relative to each other. It is described that the liquid is made into fine particles by the method, and in that state, a low voltage is applied between the brush and the metal container, and the current is measured.

However, in the method and apparatus described in the above publication, since the conductive liquid is made into fine particles by the brush, the inner surface of the metal can has a complicated shape in which the tip of the brush is hard to reach (for example, from the middle. It is difficult to spread the conductive liquid evenly over the surface of the inner coating when the shape is small or spiral irregularities are formed near the opening on one end side. is there. As a result, there is a possibility that the defect detection accuracy of the inner coating and the reliability of the inspection may decrease. Further, even if the inner surface shape of the metal can is such that the tip of the brush can reach, if the brush is relatively rotated while being in contact with the inner surface coating of the metal can, the inner surface coating may be damaged by the brush or repeated. Due to contact with the inner coating, the tip of the brush may be worn or broken, and the broken portion of the brush may remain attached to the inner coating. Therefore, after inspecting the inner coating, it is necessary to inspect whether the fragments of the brush are attached to the inner coating of the metal can.However, if the fragments are minute, it is difficult to detect the fragments. However, in order to remove such debris, a separate washing and removing process of washing the inner surface of the metal can to remove debris is required, which complicates the inspection process and may reduce the inspection efficiency.

Therefore, even if the metal can has an opening formed at least at one end and the inner surface of the metal can has a complicated shape, the inner surface coating can be satisfactorily detected for defects and applied to 100% inspection. The applicant has already filed Japanese Patent Application No. 2001-132403 for possible inner surface coating inspection method and apparatus.

[0009]

However, the following problems have occurred when detecting defects in the inner coating. That is, due to deterioration of the sealing material of the Abber seal rubber, which is a sealing jig that seals the large-diameter opening side of the metal container body, malfunction of the Abber seal sleeve, etc.
A perfect seal is not formed, and the filled test water leaks from the large-diameter opening, and leaks between the conductive member that is inserted inside the container and the other electrode that contacts the part where the inner surface coating does not exist. It becomes conductive via the discharged inspection water, and an appropriate detection current cannot be obtained, and accordingly, an appropriate defect inspection of the inner surface coating cannot be performed.

Further, deterioration of the sealing material of the lower seal rubber, which is a sealing jig for sealing the side of the small diameter opening which is the lower side opening of the body of the metal container, and the tip of the cylindrical portion on the side of the small diameter opening. A perfect seal is not formed due to defective molding of the curl part formed by external winding, and the filled test water leaks from the small diameter opening, and a suitable amount of test water is filled into the metal container during voltage application. Since the test water is insufficient, there is a portion where the test water does not reach the inner surface coating to be inspected, and it is not possible to inspect for defects in that portion, or there is a leak to the area where the inner surface coating does not exist at the tip of the curl edge. Even if the discharged test water comes into contact with the conductive member inserted into the container and the electrode is brought into conduction through the test water, a proper detection current cannot be obtained.

Furthermore, if the test water is not electrochemically adjusted to a predetermined level, the electrical properties of the test water change, and a normal detection current cannot be obtained, which also causes defects in the inner coating. Not exactly done.

Furthermore, it is also possible that various electrical system failures are caused. That is, a conductive member or electrode, a voltage applying device for applying a voltage between the conductive member and the electrode, a switch for turning on / off the power supply of the voltage applying device, an ammeter for measuring a detected current, in each station, or The voltage becomes normal due to an abnormality in various sensors or electronic control devices that detect the position, movement, stop, etc. of the body part of the metal container between stations, or due to a break in the electrical circuit system that connects them. If the voltage is not applied or if there is an abnormality in the electric circuit such as a contact failure of the electrode that should contact the body of the metal container, the detected current becomes unstable and the defect detection of the inner coating is incomplete. It can only be done.

As a result, there is a problem that an erroneous determination that a defective product is a good product is generated, and an erroneous determination that a good product is a defective product is generated and a non-defective product is discharged.

The present invention has been made in view of the above circumstances. Regardless of the shape of the inner surface of a metal container having an opening formed at least at one end, the reliability of inspection and the product quality in the detection of defects in the inner surface coating film are improved. It is an object of the present invention to provide an inspection device that can improve the assurance of the.

[0015]

In order to achieve the above-mentioned object, the invention of claim 1 provides an opening formed at least at one end and a non-conductive material provided on the inner peripheral surface. In an inner surface coating inspection device for a metal container for detecting defects in the inner surface coating in a metal container provided with an inner surface coating,
A conductive member inserted into the inside of the metal container through the opening and the metal container and the conductive member are moved relatively to each other, so that the conductive member is inside the metal container and the conductive member. A non-contact insertion into the metal container, and a drive device for retracting the conductive member from the inside of the metal container to the outside, and an electrode contacting a portion of the metal container where the inner surface coating does not exist. , The conductive member is inserted into the inside of the metal container, over a region facing the inner surface coating in the metal container and a region facing the conductive member, a test water supply device for filling test water, The conductive member inserted inside the metal container under a state of being filled with test water over a region facing the inner surface coating and a region facing the conductive member inside the metal container. A voltage applying device that applies a voltage between the electrode and the electrode that is in contact with the metal container; an ammeter that detects a current flowing through the test water by applying a voltage by the voltage applying device; When the current value in the steady state area of the current detected by the meter is compared with the preset good product current value, and the detected current value exceeds the preset good product current value In, the inner coating defect determining means for determining that there is a defect in the inner coating of the metal container, the detection current monitoring means for monitoring the detection state of the current, the inner coating defect determination means there is a defect in the inner coating When it is determined, or when the detected current monitoring means recognizes that the current detection state is abnormal, it is provided with a determination means for outputting a signal instructing the discharge of the metal container. You It is a device.

According to the invention of claim 1, the conductive member is inserted into the inside of the metal container having the opening formed at least at one end, and the electrode is brought into contact with the portion of the metal container where the inner surface coating does not exist. The test water is filled over the region facing the inner surface coating of the metal container and the region facing the conductive member, a voltage is applied between the conductive member and the electrode, and the inner surface is based on the current flowing through the test water. Even if the inner surface of the metal container has a complicated shape, the inspection water with high fluidity penetrates along the complicated inner surface shape to detect the presence or absence of film defects. Is increased.

Further, the detected current monitoring means monitors the detected state of the current, and when it recognizes that the inner surface coating inspection device itself has an abnormality, it instructs the metal container to be discharged. It is possible to obviate the problem caused by imperfect detection of defects on the inner surface coating due to various factors, that is, due to various factors.
In other words, it is possible to recognize that the inspection is incomplete due to an abnormal operation of the inspection device and discharge the metal container that was the object of the inspection when the inspection is incomplete as an incomplete inspection. It is possible to prevent an erroneous product determination or a defective product determination of the metal container by the coating inspection.

In this way, the presence or absence of defects in the inner coating is detected based on the detected current, while confirming that the inner coating inspecting device itself is functioning normally every time the inner coating is detected as defective. Therefore, the reliability of the inspection by the inner surface coating inspection device can be improved. That is, since the inspection operation is performed while monitoring the operation abnormality of the inspection apparatus itself, the inspection is performed after confirming that the inspection apparatus operates normally, and the reliability of the inspection can be secured.

Furthermore, the function of the inspection apparatus itself is diagnosed by using the current detected by the voltage application without additionally providing an electrical configuration such as a power supply voltage device or a sensor for diagnosis. , Low cost.

According to a second aspect of the present invention, there is provided a metal container inner surface coating inspection device for inspecting an inner surface coating of a metal container provided with a non-conductive inner surface coating, wherein the metal portion of the metal container has one polarity. An application device for applying an arbitrary voltage with a conductive member arranged in the container having an opposite polarity, and an inspection water supply device for filling the metal container with inspection water having an electrochemical property required for the inspection. And an inner coating defect determining means for determining a defect of the inner coating based on a current detected when the inspection water is filled and a voltage is applied by the applying device, and a detection state pattern of the current is identified. Then, the apparatus is provided with a detected current monitoring means for judging the inspection operation of the inspection apparatus.

According to the second aspect of the present invention, the inner surface coating film inspection apparatus itself functions normally to perform the inner surface coating film inspection operation by monitoring the current detection state pattern by the detected current monitoring means. Since it is possible to detect the presence or absence of a defect in the inner surface coating film based on the detected current while checking, it is possible to improve the reliability of the inspection by the inner surface coating film inspection apparatus. That is, since the inspection operation is performed while constantly monitoring the operation abnormality of the inspection device, it is possible to ensure the reliability of the inspection for the non-defective product determination when the normal operation is confirmed.

According to a third aspect of the present invention, in addition to the configuration of the first or second aspect, the detected current monitoring means monitors a current detection state in a region where a voltage application is started and is in a transient state, An apparatus comprising: a first current determination unit that determines that the inspection apparatus itself has an abnormality when the maximum current value detected in the transient region is smaller than a predetermined current value. is there.

According to the third aspect of the present invention, in addition to the same effect as that of the first or second aspect of the present invention, the current detected in the region in which a voltage is applied and in a transient state causes the inspection apparatus itself to Since the operation abnormality is determined, the reliability of the inspection and the assurance of the inspection quality can be ensured. That is, when it is determined that the inspection device normally operates, the detected current in the transient state is properly detected, and thus the detected current reflecting the defect state of the inner coating was properly measured. Therefore, it is possible to sufficiently secure the reliability of the defect determination of the inner surface coating of the metal container based on the detected current.

According to a fourth aspect of the present invention, in addition to the configuration of any one of the first to third aspects, the detected current monitoring means is in a steady state after the transitional region is completed. When the difference between the maximum value and the minimum value of the current detected in the steady region is larger than a predetermined current fluctuation width value, the inspection device itself is monitored. The apparatus is provided with a second current determining means for determining that there is an abnormality.

According to the invention of claim 4, in addition to the same operation as the invention of any one of claims 1 to 3,
Since the operation abnormality of the inspection device itself is determined based on the fluctuation range of the current detected in the steady state region, it is possible to further secure the reliability of the inspection and the assurance of the inspection quality. That is, when it is determined that the inspection device operates normally, it means that the detection current in the steady state is properly detected. Therefore, it is possible to sufficiently secure the reliability of the defect determination of the inner surface coating of the metal container based on such detected current.

When inspecting the quality of the inner surface coating,
Since the normal operation of the inspection device is checked by the detection state of the current detected in the steady region that reflects the defect state of the inner surface coating, the reliability of the inspection is further improved.

The detection current used in this specification includes not only the current flowing through the conductor but also the discharge current flowing through the insulator. That is, even if the inner surface coating is a normal inner surface coating, if the inner surface coating used in the metal container is a thin film having a low withstand voltage, a slight discharge current is detected when a voltage is applied.

[0028]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Specific examples of the present invention will be described below with reference to the drawings. The defect detection method of the present invention is shown in FIG.
The defect inspection station K1 shown in FIG. 1, a water drop removing station (not shown), and a drying station (not shown) are divided. First, the configuration of the inspection device used in the defect inspection station K1 will be described with reference to FIGS. FIG. 1 shows a bottle-shaped can body 1 with a screw, which is an inspection object, and an inspection device 2 for inspecting the bottle-shaped can body 1.
2 is a block diagram mainly showing a control circuit of the inspection apparatus of the present invention. The bottle-shaped can body 1 includes a metal container body portion 3 formed in a tubular shape, and an inner surface coating 4 applied to the entire inner peripheral surface of the metal container body portion 3, and openings are formed at both ends thereof. ing.

The metal container body 3 is made of a conductive material such as a surface-treated steel plate or an aluminum alloy plate. The metal container body 3 has a cylindrical body 6 having a large-diameter opening 5 on one end side, and a predetermined range is reduced in diameter from an opening end of the body 6 opposite to the large-diameter opening 5. A shoulder portion 7 formed on the body portion 6 and having an arcuate cross-section from the body portion 6 side, and a small diameter connected to the shoulder portion 7 and having a screw cap (not shown) attached to the outer peripheral portion thereof. And a mouth / neck portion 8. The small-diameter mouth / neck portion 8 has a curl portion 81 formed by winding the tip of a cylindrical portion outward, and a screw portion 82 continuously formed on the shoulder portion 7 side of the curl portion 81. . A small diameter opening 80 is formed in the small diameter mouth / neck portion 8.

As a method of manufacturing the bottle type can body 1 as described above, there are the following first method and second method. The first method is, for example, as shown in FIG. 1, an epoxy-phenolic paint, an acryl-modified epoxy-phenolic paint, or an epoxy-urea on the inner peripheral surface of the metal container body 3 processed into a cylindrical shape. A bottle type can body 1 having an inner coating 4 by spraying a paint such as a system paint in a liquid state and drying and baking the paint.
Is a method of manufacturing. In the second method, a thermoplastic resin film or an inner resin film is attached or extruded on the surface of a metal plate to produce a resin-coated metal plate.
As the thermoplastic resin film, polyester-based, polypropylene-based, nylon-based or the like is used, and as the inner surface resin film, an oriented crystal inner surface resin film or an amorphous structure is used. Next, this resin-coated metal plate is drawn and redrawn or drawn and ironed to form a cylindrical can body with a bottom, and then drawn and smoothed several times on the bottom side of the bottom can body. The small-diameter mouth / neck portion 8 and the shoulder portion 7 are formed by performing the chemical processing. Further, the tip of the small-diameter mouth / neck portion 8 is cut and opened, and the tip portion of the small-diameter mouth / neck portion 8 is externally wound to form a curl portion 81, and a screw portion 82 is formed below the curl portion 81, and a tamper evidence mechanism is formed. The bottle-shaped can body 1 having the inner coating 4 is manufactured by forming the annular protrusion 83 for fixing the breaking band of the cap (not shown).

On the other hand, the inspection device 2 has an insertion head 100 which is an insertion member inserted into the bottle type can body 1 through the large diameter opening 5. This insertion head 10
0 is made of an insulating material (for example, synthetic resin), and the outer surface of the insertion head 100 has a shape similar to the inner surface of the bottle-shaped can body 1. That is, the shape is smaller and similar to the shape formed by the inner peripheral surface of the metal container body 3 of the bottle-type can body 1 to be inspected. The insertion head 100 connects a hollow shaft-shaped portion having a diameter smaller than that of the metal container body portion 3, a small-diameter shaft portion 12 having a diameter smaller than that of the small-diameter mouth neck portion 8 of the bottle-type can body 1, and these portions. And a shoulder portion 11. The current detection electrode 19 is provided so as to cover almost the entire outer peripheral surface of the insertion head 100. Therefore, the current detecting electrode 19 is smaller than the inner peripheral surface of the metal container body 3 and has a shape similar to the inner peripheral surface, and the current detecting electrode 19 and the inner peripheral surface of the metal container body 3 are at a substantially constant interval. (Eg 2 to 3
mm) and are opposed to each other. Since the current detection electrode 19 is formed to cover 95% or more of the outer peripheral surface of the insertion head 100 facing the inner peripheral surface of the metal container body 3, the inner peripheral surface of the metal container body 3 is covered. Almost the entire inner peripheral surface of the bottle-shaped can, which is commercialized, faces the current detection electrode 19. In particular, it is preferable that a portion of the outer peripheral surface of the insertion head 100, which faces the inner surface coating 4 of the body portion 6 of the metal container body portion 3 which is likely to cause a defect due to ironing, is covered with the current detection electrode 19,
It is more preferable to cover almost 100% of the insertion head 100 with the current detection electrode 19. In addition, the insertion head 100,
An upper cylinder mechanism 9A (see FIG. 2) is provided for reciprocating the bottle type can body 1 in the axial direction, specifically, in the vertical direction.

The insertion head 100 is attached to the tip portion (lower end portion in FIG. 1) of the clamp cylinder 102. The clamp cylinder 102 includes a cylindrical upper seal sleeve 98 and a piston rod 10.
4, and the piston rod 104 thereof projects toward the tip end side (lower side in FIG. 1). A portion of the core rod that axially penetrates the upper seal sleeve 98 and the central portion of the piston rod 104 is integrated with the insertion head 100, and the base end portion of the insertion head 100 (the end portion on the clamping cylinder 102 side) is formed. On the outer circumference, the piston rod 10
The upper seal rubber 96 and the guide ring 106 are fitted in order from the 4 side.

The upper seal rubber 96 is made of an elastically deformable material and is formed in a ring shape having an outer diameter slightly smaller than the inner diameter of the large diameter opening 5 of the metal container body 3, and is pressed by the piston rod 104. By doing so, it expands to the outer peripheral side. A receiving ring 107 having an inner diameter substantially equal to the outer diameter of the large-diameter opening 5 is arranged on the outer peripheral side of the upper seal rubber 96 so as to face the upper seal rubber 96 in the radial direction. . Therefore, by inserting the large-diameter opening 5 of the metal container body 3 between the upper seal rubber 96 and the receiving ring 107, and then pressing the upper seal rubber 96 by the piston rod 104, the metal container body 3 is pressed. The large-diameter opening 3 of 3 is clamped by the upper seal rubber 96 and the receiving ring 107.

Between the receiving ring 107 and the upper seal rubber 96 and the clamping cylinder 102,
The edge electrode 20 is provided. That is, the large-diameter opening 5 of the metal container body 3 fitted to the outer peripheral side of the upper seal rubber 96 is brought into contact with the edge electrode 20 so as to be electrically connected to a voltage applying device (not shown). The receiving ring 107 is fixed to the tip of the clamping cylinder 102 so that the edge electrode 20 is sandwiched between the edge ring 20 and the tip of the clamping cylinder 102.

The guide ring 106 disposed on the opposite side of the piston rod 104 with the upper seal rubber 96 sandwiched therebetween has a reaction from the lower side when the upper seal rubber 96 is pressed by the piston rod 104 from the upper side. It is a so-called receiving member that generates force and holds the upper seal rubber 96, and its outer peripheral surface is formed in a tapered shape in which the diameter gradually decreases from the upper seal rubber 96 side toward the current detection electrode 19 side. That is, when the insertion head 100 is inserted into the inner circumference of the metal container body 3, the large-diameter opening 5 is guided to the outer peripheral side of the upper seal rubber 96 to make the insertion head 100 and the metal container body 3 identical. It is designed to match on the axis.
Each part other than each of the electrodes 19 and 20 is made of an insulating material such as synthetic resin.

On the other hand, below the insertion head 100, a sealing jig 33 for opening and closing a small diameter opening 80 formed at the lower end side of the small diameter neck 8 is provided. This sealing jig 3
3 is a pedestal formed by stacking substantially short cylinders, and a drainage channel 95d that can be arbitrarily closed or opened is provided inside thereof, and communicates with the drainage channel 95d at its upper portion, and the lower end of the metal container body 3 Is provided with a close contact portion. That is, the block 95c has at least the small-diameter opening 80.
Is formed in a short cylindrical shape having a larger diameter than the outer diameter, and a recess having a predetermined diameter is provided at the center of the upper portion, and a passage is formed from the recess to the side surface. A substantially wide ring-shaped housing 95b having a drain 95e of a predetermined diameter is provided above the block 95c, and a drain 95d extending from the drain 95e to the side surface is formed. The drain port 95e of the housing 95b can be arbitrarily opened and closed by a lower seal sleeve 99. That is,
The upper portion of the lower seal sleeve 99 has a drain port 95.
It has a large diameter with a hemispherical shape larger than the inner diameter of e, and its lower portion is formed into a long rod shape. The upper portion is on the same axis as the diameter center of the drain outlet 95e, and the upper portion is the drain outlet 95e.
The block 95c is disposed in the block 95c, and the lower end portion of the block 95c passes through a through hole provided in the block 95c.
Air cylinder mechanism (not shown) protruding downward from c
It is connected to the. Therefore, the lower cylinder sleeve 99 is arbitrarily moved up and down by the air cylinder mechanism, and the drain port 95e is closed and opened by the upper portion of the lower cylinder sleeve 99.

A cylindrical protrusion protruding upward is formed on the upper side of the housing 95b, and the small-diameter opening 80 of the metal container body 3 is guided by interposing this protrusion and the lower seal rubber 97. A tubular cap 95a is attached. That is, the cap 95a has an inner diameter slightly larger than the outer diameter of the small-diameter opening 80 of the metal container body 3, and an inwardly projecting protrusion is provided therein. The lower seal rubber 97 is made of an elastically deformable material and has an inner diameter smaller than the inner diameter of the small diameter opening 80 of the metal container body 3 and an outer diameter larger than the outer diameter of the small diameter opening 80. Has been formed. Therefore, the lower seal rubber 97 includes the cap 95a and the housing 9
5b, a lower pocket cap 95a including a block 95c and a housing 95b are sandwiched and fixed. Further, the sealing jig 33 is the lower cylinder mechanism 3
7 (see FIG. 2) so that it can be arbitrarily moved up and down, and the lower cylinder mechanism 37 (see FIG. 2) drives the sealing jig 33 upward to move the metal container body 3 The lower seal rubber 97 is brought into close contact with the small-diameter opening 80 of the above so that the drainage port 95e of the drainage channel 95d provided in the sealing jig 33 can be communicated.

Therefore, when the defect of the inner surface coating is detected, the lower seal rubber 97 is brought into close contact with the small diameter opening 80 of the metal container body 3, and the small diameter opening 80 which is the lower side opening of the metal container body 3. Is communicated with the drainage channel 95d of the sealing jig 33, and the lower seal sleeve 99 is driven to rise.
By the upper end of the lower seal sleeve 99, the drainage channel 95
By closing the drain port 95e of d, the small diameter opening 8
0 is sealed so that the inspection water 17 does not flow out from the metal container body 3 through the small diameter opening 80. When the inspection water 17 is drained after the inspection is completed, the lower seal sleeve 99 is driven downward to open the drain port 95e, and the inspection water 17 passes through the drainage channel 95d and is discharged from the metal container body 3. To be done. The lower seal rubber 97, the lower seal sleeve 99, the cap 95a, and the housing 95b are made of an insulating material such as synthetic resin.

A water supply channel 109 is formed along the central axis of the insertion head 100, and the water supply channel 109 is formed.
While opening at the tip of the insertion head 100, it branches off from the middle and opens at a location near the shoulder. A check valve 110 is provided in the water supply passage 109. Further, the water supply passage 109 is connected to a pure water supply pump (not shown) by a pipe through an ion exchange processor (not shown).

At the upper end of the insertion head 100, a plurality of overflow outlets 113 are provided slightly on the tip side (lower side in FIG. 1) of the guide ring 106. The overflow outlets 113 are the core rods. Is communicated with a drainage channel 114 formed by penetrating the portion in the axial direction. To this drainage channel 114, one end of a drainage pipe 115 protruding outside the insertion head 100 is connected. A three-way valve (not shown) is connected to the other end of the drain pipe 115, and the other first valve of the three-way valve is connected to the outside so as to open to the atmosphere side. At the same time, the other second valve is connected to a pressurized air source (not shown). Therefore, when the inspection water is supplied by switching the three-way valve, the inside of the metal container body 3 is opened to communicate with the outside atmosphere side, while the inspection water inside the metal container body 3 is discharged. At this time, a pressurized air source (not shown) can communicate with the inside of the metal container body 3.

In FIG. 1, reference numeral 116 denotes a positive electrode lead wire connected to the current detection electrode 19, reference numeral 117 denotes a negative electrode lead wire connected to the edge electrode 20, and reference numeral 118. Indicates an air supply pipe for supplying air to the clamping cylinder 102 and the upper seal sleeve 98 for the clamp operation, and reference numeral 119 supplies air to the clamping cylinder 102 and the upper seal sleeve 98 for release. The air supply pipe which does is shown.

Further, the edge electrode 20 has a ring shape and a plate shape. That is, the edge electrode 20 projects like a collar from the outer peripheral surface of the body portion 10, and the outer diameter of the edge electrode 20 is set to be larger than the outer diameter of the bottle-type can body 1. In addition, the current detection electrode 19
Is connected to the positive electrode of the DC power supply 22 via the switch 21, while the edge electrode 20 is connected to the negative electrode of the DC power supply 22. When the switch 21 is turned on / off, the voltage applied to the current detection electrode 19 is lower than the withstand voltage of the inner surface coating 4 (this voltage is the type of the inner surface coating 4, the thickness of the inner surface coating 4, the inner surface coating 4). Although it depends on the crystallinity of the coating film 4 and the like, it is maintained at, for example, 200 to 700 V). An ammeter 23 is provided between the negative electrode of the DC power source 22 and the edge electrode 20,
The output terminal of the ammeter 23 is connected to the data processor 24. The data processor 24 is also connected to the electronic control unit 58. Further, an inspection device that analyzes the current value measured by the ammeter 23 and determines by the defect determination circuit 91 of the electronic control unit 58 whether or not a defect has occurred in the inner coating 4 and detects a defect in the inner coating 4. Whether or not the device 2 itself is operating normally is determined by the inrush current determination circuit 92 and the converging current determination circuit 93 of the electronic control unit 58.

Further, the operation of loading the bottle-shaped can body 1 from the previous process to the inspection station, the transfer of the bottle-shaped can body 1 between the stations, and the discharge of the bottle-shaped can body 1 from the drying station to the subsequent process. A transport device (not shown) that performs the above-described operation is provided. This transfer device includes known actuators (not shown) such as an electric motor and a cylinder, and known mechanisms such as a turntable, a belt conveyor, and a chuck that are operated by these actuators. Furthermore, during each station,
Alternatively, various sensors 57 are provided for photoelectrically or mechanically detecting the position, movement, and stop of the bottle-shaped can body 1 between the stations. Furthermore, a discharging mechanism 59 for discharging the bottle-shaped can body 1 determined to have a defect in the inner coating 4 out of the line is provided.

Furthermore, an electronic control unit 58 is provided which controls the respective parts of the inspection device in association with each other. This electronic control unit is configured by a microcomputer mainly including an arithmetic processing unit (CPU or MPU), a storage device (RAM and ROM), and an input / output interface, and based on input data, according to a program stored in the storage device, It makes various judgments and controls the operation of each device. That is, the signals of the data processor 24, the signals of various sensors 57, and the like are input to the electronic control unit 58. On the other hand, a signal for controlling each cylinder, a signal for controlling an electric motor (not shown), a signal for controlling an on-off valve (not shown), a signal for controlling a transfer device, and a flow rate control valve are output from the electronic control device 58. A signal for controlling, a signal for controlling the discharging mechanism 59, etc. are output. In addition, the electronic control unit 58 detects a defect in the inner surface coating film 4 from the detected current detected during the inspection of the bottle-shaped can body 1 input from the data processor 24, and the inspection unit 2 itself. The first current determination means (inrush current determination circuit) 92 and the second current determination means (convergent current determination circuit) 93 for determining the presence or absence of abnormality are realized.

A method of determining whether or not the inspection device is normal by using the detected current when the inspection of the inner surface coating is executed and its basis will be described below.

That is, a bottle-shaped can body 1 having an inner surface coating having a polyester-based amorphous structure having a low withstand voltage and a film thickness of about 10 to 30 μm was used as an inspection object. Then, the specific resistance of the test water using pure water is set to 0.18 MΩ · c by an ion exchange processor.
m, the inspection water was properly filled between the bottle type can body 1 and the current detection electrode 19, and the applied voltage for inspection was set to 500V. Then, when the inspection device 2 operates properly and the bottle-shaped can body 1 is a non-defective product in which the inner surface coating has no defect, the observed current is patterned and shown in FIG.

Under these conditions, the region of α shown in FIG. 3 (1) from the start of application of the inspection voltage to 30 millisecond (hereinafter referred to as ms) is considered to be a transient state. Edge electrode 20 connected to the current detection electrode 19 and the can body 1
It is considered that a conductive test water intervenes between the insulating film and the insulating inner surface film, resulting in an electric circuit configuration substantially similar to that of the capacitor. Therefore, a voltage was applied to the inner surface film to cause discharge. In the initial stage, an inrush current protruding upward is observed in a waveform. It was found that the maximum peak value α1 of the inrush current is usually about 6000 to 7000 μA.

Next, under the above experimental conditions, 30 ms have passed from the start of application of the inspection voltage, and from this 30 ms to 5
It is considered that in the steady region β of 00 ms, the detected current converges and shifts to a stable state as it approaches the end, and in the case of a good product, it was found that the detected current stably converges to 50 μA or less. Therefore, 400 ms to 500 ms from the start of application of the voltage located at the end of this β region
During this period, if the detected current value converged is smaller than the specified value of the normal product, it can be determined that the metal container is a non-defective metal container having no defect in the inner coating.

On the other hand, under the same conditions as above, when a metal container having a defect in the inner surface coating is to be inspected,
The detected current pattern shown in FIG. 3 (2) can be observed.

That is, even when a defective product having a defect in the inner surface film is inspected, an inrush current protruding upward is measured in the transient α region of 30 ms from the start of application of the inspection voltage, similarly to the above. Maximum peak value of inrush current α2
Was found to reach 6000-7000 μA.

However, in this case, in the steady β region of 30 ms to 500 ms after the application of the inspection voltage is started, the detection current corresponding to the defect of the inner surface coating also becomes a high value and is constantly measured. To be done. That is, in the case of a defective product having a defect in the inner surface coating, the detection current reflecting this defect usually converges to a value exceeding 100 to 200 μA, and therefore 100 to 100 ms during 400 ms to 500 ms from the start of voltage application. When the detected current exceeding 200 μA is measured, it can be determined that the metal container is a defective metal container having a defect in the inner coating.

From these results, first, the maximum peak value of the appropriate inrush current is usually 6000 to 7000 μA during the period from the start of voltage application to 30 ms.
A value serving as a criterion for determination can be preset to 5000 to 6000 μA. Then, as shown in FIG. 4A, the maximum value of the inrush current actually detected is the reference value 5000 to 600.
If it is lower than 0 μA, it can be determined that the operation of the inspection device itself is abnormal.

That is, the following factors can be considered as factors that prevent the inrush current from rising to the reference value.
For different reasons in each case we cannot guarantee that a proper inspection has been performed.

1) In the case where the filling amount of the test water is insufficient, in this case, a partial region of the inner surface coating which does not come into contact with the test water is generated. Defects cannot be detected. Therefore, if a defect has occurred in this partial area, this defect cannot be identified in the defect detection period described below, resulting in the defective metal container being distinguished as a non-defective product. Has been done.

The first reason why the filling amount of the test water is insufficient is that the test water leaks from the metal container. That is, having an opening at the upper and lower ends of the metal container,
This is the case where the bottom opening is not tightly sealed. The cause of this sealing failure is a) deterioration of the material of the seal member on the inspection device side that seals the lower opening, and b) the lower opening shape of the metal container on the inspection target side has a predetermined appropriate shape (within a predetermined size range). It is conceivable that it was not formed. Therefore, due to these, a gap is created between the two, and the inspection water flows out from this gap. In addition, in addition to this, even if a metal container having an opening on one end side, that is, a metal container whose lower end is not opened and which does not need to be sealed at the lower part, has a through hole in the container itself for some reason. Of course, although depending on the location and size of the through hole, the test water filled will flow out from this through hole.

The second reason is that the test water was not supplied to an appropriate filling amount. That is, it is a case where the test water is supplied insufficiently, that is, the test water is less than the prescribed filling amount from the beginning. this is,
Assuming that the flow rate is constant, this supply amount is defined by the product of the flow rate per unit time and the supply time that is the elapsed time when this flow rate has flowed. Therefore, as a cause of the shortage of the supply amount, a) one flow rate that regulates the supply amount is not satisfied with a certain amount due to physical damage to the piping of the supply system on the inspection device side, and the accumulated supply amount. And b) malfunction of the control body that controls the supply amount of test water, malfunction of the on-off valve installed in the pipe that executes the operation based on the operation command from the control body, operation command It is conceivable that the other supply time that regulates the supply amount does not actually satisfy the regulation due to a transmission error or the like due to a defective electric wiring to be transmitted, and the cumulative supply amount may similarly decrease.

It should be noted that the above-mentioned adverse effects due to insufficient filling of the test water are considered to increase as the regular filling amount of the test water decreases. In other words, if the volume of test water that is lacking due to various causes is approximately constant, the ratio of the test water that has flowed out to the test water that remains in the metal container will be large, and the capacity of a capacitor that corresponds to this will be large. It seems that the rate of decrease decreases, and it is more sensitively reflected in the decrease in inrush current.

2) Due to the fact that the current and voltage required for inspection are not properly supplied, in this case, of course, the detected measurement value for defect detection, which will be described later, is also similarly affected. The validity of the comparison between the detected value and the reference value is impaired, and the inspection becomes an invalid inspection without a substance. Will be transmitted from the inspection device.

The reason why the detected current becomes improper is that the electrical path through which the detected current flows is physically obstructed or blocked. That is, a) the metal part of the metal container and one of the electrodes contacting the metal container could not be sufficiently contacted with each other for some reason, b) disconnection of a cable or cord forming an electrical transmission path, and c) electricity. It is conceivable that leakage and grounding may occur due to a defective insulation, and that a voltage drop may occur due to an abnormal power supply voltage.

3) Due to the fact that the components and specific resistance of the test water are not adjusted to predetermined values, in this case, the electrochemical properties of the test water change, and this is reflected to detect current. The measured value of 1 also changes, and the same process as 2) is followed, and similarly, an inappropriate result is generated as an inspection.

The component or the specific resistance of the test water becomes inappropriate.
The reason for this is due to the cause that occurred when adjusting the test water. That is, a) malfunction of the adjusting device that adjusts and presets the component and specific resistance of the test water, b) human error of the operator who inputs the component and specific resistance of the test water into the adjusting device, c ) If the above malfunction or artificial setting error occurs due to the error between the measured component and the actual component due to the adjustment and malfunction of the water quality meter that measures the component and specific resistance of the test water, d) Previous When inspecting a metal container different from the above, when the material and thickness of the inner coating changes, the electrochemical properties of the inner coating change according to the change in material and thickness, while It is conceivable that there will be a mismatch, etc. when the settings of the specific components and the specific resistance remain unchanged.

The second reason is due to the cause of the adjusted test water itself. That is, in the case where the adjusted components and the specific resistance in the test water are variously affected after the adjustment, and a) when a large amount of test water is prepared, it depends on the storage state and the storage period, When a local component concentration bias occurs, b) when the adjustment component and the specific resistance show characteristics that depend on the temperature and the temperature of the test water becomes unstable,
It is possible that the ratio of the components changes and the specific resistance changes.

As a result, when the current pattern shown in FIG. 4 (1) is observed, that is, the rush current in the transient α region is smaller than the specified value indicating no defect in the inner coating, and the subsequent steady state When the detected current in the β region converges to a value indicating no defect, it can be determined that the inspection device has an abnormal operation.

Next, the detected current in the β region is shown in FIG.
When observed with the current pattern shown in (2), that is, the detected current does not become a constant value although it is tentatively constant at a certain current value, and it projects upward based on this certain current detection value. If some sharp waveforms are measured,
It can be determined that the operation of the inspection device itself is abnormal.

That is, as a factor that the detected current does not converge to a constant value and some steep waveforms are observed, the electric path is intermittently interrupted for some reason, that is, instantaneously. It is conceivable that the device will be disconnected and then reconnected, and the detected current affected by this will be improper, and it will be impossible to guarantee whether or not a proper inspection has been performed.

It is considered that this is because the contact portions of the solids conducting the current contacted and separated several times irregularly during the period of applying the voltage. In other words, during the application of voltage, the mechanism or part for stably locking and holding the metal container loosens, and the metal part of the metal container and the electrode are intermittently separated from each other due to the looseness or vibration. I think that the. Therefore, when the metal portion and the electrode are momentarily separated from each other and come into contact with each other again, an inrush current is formed and observed similarly to the start of voltage application.

As a result, each time such an inrush current is observed, the electrical state of the detected current is returned to a transient state, and it is possible that the detected current has transitioned to a stable steady state. Therefore, the converged detection current cannot be normally observed in the steady state region, and proper defect detection of the inner coating cannot be performed.

In the small-diameter opening 80 which is the lower opening of the metal container body 3, the end surface shape of the portion of the small-diameter opening 80 which comes into contact with the seal member is formed so as to be in close contact with the seal member. If there is no pressure, or if the pressing force that presses the small diameter opening against the seal member fluctuates, the contact location of the small diameter opening 80 is in a state close to a point contact from an arc line shape with respect to the seal member. Will vary. In addition, when the end of the large-diameter opening 5 of the bottle-shaped can body 1 is inserted while being inclined with respect to the edge electrode 20, or when the end of the large-diameter opening 5 is deformed and is perpendicular to the electrode. If the contact cannot be made, similar to the small-diameter opening 80,
It changes from a circular arc line shape to a state close to point contact.
Therefore, also in these cases, the unspecified and steep protrusion current as described above may be measured.

Therefore, when the current pattern as shown in FIG. 4 (2) is measured, that is, the voltage is 30 m from the application.
After s has elapsed (after the inrush detection current has been generated), the maximum time and the minimum value of the detection current measured are 470 ms from the start time to the end of the inner surface film defect detection, that is, in the β region. When it can be determined that the difference from the value (that is, the maximum fluctuation width of the detected current) is 200 μA or more, it can be determined that the inner surface coating inspection device itself is abnormal based on the above reason. In addition, the following FIG.
In each of the cases (3) to (5), the inner coating film inspection apparatus itself can be determined to be abnormal based on the reason that the detected current is determined under the same comparison condition for each case.

Further, when the detected current is observed in the current pattern shown in FIG. 4 (3) in the β region, that is, the detected current is tentatively at a certain current value, it is in the middle of the period of the β region. If the detected current rises from an indefinite point of time, it can be determined that the inspection device has an abnormal operation.

That is, as a factor that the detected current increases from an indefinite point in the middle of the period, even if the inner surface coating is defect-free, at some point in the middle of the period, the leaked test water bypasses the insulative inner surface coating so that the electrical conductivity is high. It is conceivable that a proper path will be formed and an improper conduction state will be established, and this conduction state will interfere with the proper detection current at the end of the period, so that proper inspection cannot be performed.

This is a metal container having openings at both ends, that is, on the upper side and the lower side, in an upper or lower sealed state that separates the inner surface side of the metal container having the inner surface coating from the other metal parts, The reason may be that some trouble has occurred.

That is, as the first reason why the upper or lower sealing condition is disturbed, the upper or lower sealing member is deteriorated, and the test water spontaneously drains even a little, and it takes a certain amount of time. Then, the case where an electrical conduction path is formed is mentioned.

As the second reason, even if the upper or lower seal member is not deteriorated, if the opening shape of the metal container is not properly formed, the inspection water is There is a case where the electrical conduction path is formed with a slight delay and a time delay. this is,
In particular, when a curl edge is formed in the small diameter opening of the metal container on the lower end side, even a small amount of test water leaks out, and this test water is the boundary between the surface on which the inner coating is formed and the surface of the metal part. By reaching this end, the inner and outer electrodes become conductive via the leaked test water in a form bypassing the inner coating, and the detected current rises and appears. Also, this is because it takes some time for the leaked test water to reach the boundary part of the shape in which the end that is the curl portion of the small-diameter opening is rolled up,
The current does not immediately become conductive after the leakage starts, and the current increase starts at an indefinite point even during the steady state period. Furthermore, since the curled edge whose cross-sectional shape is arcuate and the seal member whose contact part has a straight cross-sectional shape, it is apparently formed into a cylindrical shape by a thin plate, although it depends on the radius of the arcuate part. Even if the contact portion increases and the sealing member elastically deforms and covers compared to the end of the square shape, the pressing force will be dispersed, the sealing ability will decrease, and even a small amount of test water It seems to be a factor causing leakage. Also, if the vicinity of the large-diameter opening on the upper side is deformed, or if the pressing force of the upper seal is reduced, even a small amount of test water leaks from the upper side, and the inner surface passes through the leaked test water. The inner and outer electrodes become conductive while bypassing the coating, and the detection current increases. At this time as well, similar to the phenomenon of the small-diameter opening, it is necessary for some time to elapse, so the test water does not immediately become conductive after it begins to leak, and is indefinite even during the steady state period. At some point, the increase of the detection current will start.

As a third reason related to the above-mentioned first and second reasons, the metal container is set in the inspection device in a proper posture, but if this posture is slightly tilted, the contact end portion is contacted. The entire peripheral portion of the lower opening, which is the location, is biased toward the seal side, and the test water may easily leak from the location where the pressing force is insufficient. Similarly, if the attitude of the metal container is slightly inclined, contact failure between the upper opening portion and the seal portion similarly occurs, and leakage of test water easily occurs from the contact failure location. This is because the longer the total length of the metal container, that is, the longer the length from the upper opening held by the inspection device to the lower small-diameter opening, the pressing force caused by the slight tilting of the posture. The homogenization is increased, and leakage of test water easily occurs in the upper opening or the lower small-diameter opening.

Next, the detected current in the β region is shown in FIG.
When observed with the current pattern shown in (4), that is, after the detected current ends the transitional state, that is, in the region of α, the current value temporarily becomes a certain current value, but immediately after that, the current value is set as the starting time point and If the detected current increases, it can be determined that the inspection device has an abnormal operation.

That is, the reason why the detected current gradually increases from the start of the β region in this manner is that even if the inner surface coating is defect-free, the leaked test water bypasses the insulating inner surface coating, and the electrical inspection is performed. It is conceivable that a path is formed and an illegal electrical connection is established, and the leakage of test water accumulates over time, and the contact part that conducts with the test water expands. Since proper detection currents are all disturbed, proper inspection cannot be performed.

This means that some trouble may occur in the sealed state on the upper side or the lower side of the metal container that separates the inner surface side of the metal container on which the inner surface coating is present from the other metal parts, and the test water may be discharged from the metal container. It is considered that the leakage is from the upper side or the lower side.

That is, the first reason why the upper or lower sealed state is impaired is that the upper or lower sealing member deteriorates, and the inspection water continues to drain through this deteriorated portion even if only a little. It is possible to continue expanding while forming a general conduction path. This is probably because even if the test water is properly filled, the test water continues to squeeze out little by little due to the insufficient sealing ability on the upper side or the lower side of the metal container.

The second reason is that even if the upper or lower seal member is normal, the opening of the metal container to be sealed by the seal member is not formed in a predetermined proper shape (within a predetermined size range). Is mentioned. This is because the sealing member cannot be sufficiently adhered to the opening because the opening is not formed in a predetermined proper shape, and the inspection water continues to drain from the insufficiently adhered portion even little by little. . Therefore, similarly to the first reason, the electrically conducting path is formed and expanded by the test water that has continued to drain slowly.

Next, the detected current in the β region is shown in FIG.
When observed in the current pattern shown in (5), that is, even when the detected current reaches the end point of the transient state, the inner coating does not decrease to a defect-free current value or a current value indicating a defect,
If the detected current value gradually decreases from the current value in the middle until the end of the steady period, it can be determined that the inspection device has an abnormal operation.

That is, the reason why the detected current gradually decreases from the start of the β region in this way is that even if the inner coating is not defective, the upper sealed state is impaired and
The test water was overfilled from the time of filling.

In this case, the overfilled test water overflows from the upper side due to insufficient sealing of the upper side, and the overflowed test water makes wide contact with the upper edge electrode, resulting in an incorrect conduction state. After that, the leakage continues from the overflowed portion, so that the contact area between the overflowed test water and the electrode decreases with time. Therefore, since the contact is made in a wide range at the beginning, the detected current value is large, but the detected current value decreases as the contact range decreases.

A method for detecting the presence / absence of a defect in the inner coating 4 of the bottle-type can body 1 by the inspection apparatus 2 configured as described above, and whether the inspection apparatus for the inner coating 4 is operating normally or not. The method of determining is described. First, the bottle type can body 1 provided with the inner coating 4 is subjected to the defect inspection station K1 from the previous step by a container supply device (not shown) including, for example, a conveyor and a chuck mechanism.
Be delivered to. Then, as shown in FIG. 1, with the axis of the bottle-shaped can body 1 oriented vertically and the small-diameter mouth / neck portion 8 directed downward, the bottle-shaped can body 1 is sealed with the small-diameter opening 80. The bottle-shaped can body 1 and the sealing jig 33 are relatively moved so that the tool 33 approaches, and the small-diameter mouth / neck portion 8 of the bottle-shaped can body 1 is inserted into the cap 95 a of the sealing jig 33. When the bottle type can body 1 and the sealing jig 33 are moved relative to each other, for example, a moving device including a chuck mechanism, an electric motor, a rack and pinion mechanism, a hydraulic or pneumatic cylinder, a cam mechanism, etc. (Not shown) is used.

Then, the small diameter opening 80 of the bottle type can body 1
And the lower seal rubber 97 of the sealing jig 33 come into contact with each other, the relative movement between the bottle-type can body 1 and the sealing jig 33 ends (that is, stops), and the lower seal rubber 97 causes the small-diameter opening 80. Liquid-tightly seal. Before the operation of the sealing jig 33, the lower seal sleeve 99 of the sealing jig 33 is driven upward, and the upper end portion of the lower seal sleeve 99 closes the drain port 95e of the drain passage 95d. I shall. As described above, the small-diameter opening 80 of the bottle-shaped can body 1 is closed by the sealing jig 33, whereby the setting of the bottle-shaped can body 1 at the defect inspection station K1 is completed.

When the setting of the bottle type can body 1 is completed, the insertion head 100 starts descending by the operation of the upper cylinder mechanism 9A (see FIG. 2). Then, the insertion head 100 passes through the large-diameter opening 5 and enters the inside of the bottle-shaped can body 1, and the edge electrode 20 faces the large-diameter opening 5 as shown in FIG. The insertion head 100 stops when it contacts the open end 5 </ b> A of No. 6.
In this way, when the insertion head 100 is inserted into the bottle-shaped can body 1 and stopped, the insertion head 10
A space is formed between the outer surface of No. 0 and the inner coating 4. After that, air is supplied from the air supply pipe 118, and the upper seal sleeve 98 descends in the vertical direction,
The upper seal rubber 96 is pressed by the upper seal sleeve 98, the upper seal rubber 96 expands toward the receiving ring 107 side, and as a result, the large diameter opening 5 of the bottle type can body 1 is sealed and injected into the space. The water 17 and the edge electrode 20 are electrically insulated.

The distance between the outer surface of the insertion head 100 and the inner coating 4 is not particularly limited, but it is possible to reduce defects by reducing the amount of inspection water 17 supplied to the inside of the bottle type can body 1. In order to increase the inspection speed, it is preferable to set the distance between the outer surface of the insertion head 100 and the inner coating 4 to about 1 to 4 mm. Further, considering the insertability when the insertion head 100 is inserted into the bottle-shaped can body 1 and the radial and axial positioning of the insertion head 100 and the bottle-shaped can body 1, The distance between the outer surface and the inner coating 4 is 2 to 3 mm
It is even more preferable to set it to a degree. The plurality of inspection water injection ports 15, the current detection electrode 19, and the inner coating 4 face the space.

Then, the test water 17 is supplied to the space through the water supply passage 109 and the test water inlet 15 by the operation of the flow rate control valve 18. Here, since the plurality of overflow outlets 113 face the space, the air in the space flows from the plurality of overflow outlets 113 to the drainage channel 11.
4, the test water 17 is smoothly supplied to the space by being discharged to the atmosphere through the drain pipe 115 and the three-way valve (not shown). On the other hand, when the water level of the test water 17 in the space rises and a specified amount of the test water 17 is injected into the space, the operation of the flow rate control valve 18 stops the supply of the test water 17.

Then, when the metal container body 3 has passed a predetermined voltage application position, a voltage for inspection is applied to the current detection electrode 19 by turning on / off the switch 21.
This voltage is controlled to a voltage lower than the withstand voltage of the inner coating 4, for example, 200V to 700V. The defects that occur in the inner coating 4 include cracks, scratches, pinholes, network defects that form a mesh-like crack on the surface, and minute metal pieces that are generated when the bottle-shaped can body 1 is formed. There is a one-sided adhesion defect. When defects such as cracks, scratches, and pinholes occur, the inspection water 17 penetrates into the cracks, scratches, and pinholes, directly contacts the metal base of the bottle-shaped can body 1, and an electric current flows by energization. . In addition, as in the case of the mesh defect, the crack does not reach the metal base, or in the case of the metal piece adhesion defect, the metal piece stuck to the inner surface coating 4 does not reach the metal base. If the inner surface coating 4 is damaged even when 17 is not energized, a current due to discharge flows.
In addition, the electric current due to the discharge also flows in the inner coating 4 having no defect. Therefore, by applying a voltage,
An electric circuit that is closed by the current detection electrode 19, the edge electrode 20, and the inspection water 17 is formed, and a current flowing through the defect, a discharge current through the defect, and a discharge through the inner surface coating 4 having no defect are formed in the electric circuit. A current such as a current flows. Here, the ammeter 23 detects a current in the range of μA, and the detection signal of the ammeter 23 is transmitted to the data processor 24. The data processor 24 removes the noise component of the input detection value signal and transmits it to the electronic control unit 58. Then, in the electronic control unit 58, the data processor 24
The presence or absence of a defect occurring in the inner coating 4 is determined from the detected current value sent from the device, and the normal or abnormal operation of the inspection device 2 that is performing the inspection is determined.

Although the detected current is used as the current value as it is, the present invention is not limited to this, and is converted into a voltage, and the above-mentioned determination is performed by using the voltage value having the high and low values according to the magnitude of the current. You can do it.

Here, the procedure of setting a determination flag relating to the defect determination of the inner coating using the inspection apparatus of this embodiment and the determination of the operation abnormality of the inspection apparatus when the defect determination is executed is shown in the flowchart of FIG. It will be explained based on.

That is, when the application of the inspection voltage is started, the operation processing shown in the flow chart is started,
First, the timer starts counting (step 1), and the maximum detected current value is held (step 2). That is, in this step 2, as long as the process returns in the subsequent step 3, the current value newly detected at that time is compared with the maximum current value held, and the newly detected current value is held. If the detected maximum current value is larger than the determined maximum current value, an update process is performed in which the detected maximum current value is replaced with a new maximum current value. In step 3, it is judged whether or not the count of the timer exceeds 30 ms. If it exceeds, it proceeds to step 4, and if it does not exceed, it proceeds to step 2
The process returns to. As a result, 30m from the start of application
The maximum current value of the current values detected in the area α up to s is acquired.

Next, in step 4, the acquired maximum current value is compared with 5000 to 6000 μA. If the maximum current value is greater than 5000 to 6000 μA, the process proceeds to step 6 and the maximum current value is 5000 to 6000 μA. If smaller, go to step 5
Then, the first abnormality flag is turned on, and the routine proceeds to step 6. Therefore, it is determined whether or not a current value exceeding 5000 to 6000 μA is detected within the region α from the start of application to 30 ms.

In step 6, the difference between the maximum value and the minimum value of the detected current value is compared with the specified value (200 μA) for judging that the inner surface coating inspection device itself is abnormal. That is, as long as the process returns in the subsequent steps 8 and 11, the newly detected current value at that time and the held maximum current value are compared, and the newly detected current value is held. When it is larger than the maximum current value, the detected current value is replaced with a new maximum current value, and the newly detected current value at that time is compared with the held minimum current value, and the newly detected current value is detected. If the current value is less than the held minimum current value, the detected current value replaces the new minimum current value and then the difference between these updated continuously held maximum and minimum detected current values. Is calculated, and finally the calculated difference and 20
A comparison is made with 0 μA. If it is determined in step 6 that the difference is smaller than 200 μA, the process proceeds to step 8, and if it is determined that the difference is larger than 200 μA, the process proceeds to step 7, and this step 7 Then, the second abnormality flag is turned on, and the routine proceeds to step 8.

In step 8, the timer count is set to 40.
It is determined whether the time exceeds 0 ms. If it exceeds, the process proceeds to step 9, and if not, the process returns to step 6. Therefore, as a result, including the processing of step 11 described later, the maximum and minimum current values detected and updated to the latest state within the range of β of less than 500 ms from the time point when 30 ms has elapsed from the start of application. If the difference is larger than 200 μA, the process of turning on the second abnormality flag is performed. That is, in the region of β, the detected current value deviates from a certain range and does not converge to a predetermined current value. Therefore, it is determined that the inspection device has abnormally operated, and the second abnormality flag is turned on. There is.

In step 9, the detected current value is compared with the normal value 100 to 200 μA of the normal value. If the detected current value is less than 100 to 200 μA, the process proceeds to step 11 to detect the detected current. Value is 100-200μA
In the above case, the process proceeds to step 10 and step 1
At 0, the defect determination flag is turned on, and step 11
Proceed to.

At step 11, the timer count is 5
It is determined whether or not 00 ms is exceeded, and when it is exceeded, this control routine ends, while when it is not exceeded, the process returns to step 6. Therefore, when a current value of 100 to 200 μA or more is detected within a period of less than 500 ms from the time point when 400 ms has elapsed from the start of application, it is determined that the inner coating has a defect and the defect determination flag is set. The process of turning on is performed. At the same time, the detected current value deviates from a certain range and does not converge to a predetermined current value. Therefore, the process of determining that the inspection device has abnormally operated and turning on the second abnormality flag is also performed.
It will be continued.

The count value of each timer, each flag, the maximum value and the minimum value of the detected current are cleared when the process returns or when the process starts, and are reset to the initial values.

Next, the procedure for determining the inspection result of the metal container based on the determination flag determined by the above-described process and determining that the inspection device 2 is normal or abnormal will be described with reference to the flowchart shown in FIG. To do.

First, at step 101, it is judged if the first abnormality flag is in the on state. If this condition is satisfied, the routine proceeds to step 106, and if not, the routine proceeds to step 102. That is, if the first abnormality flag is in the off state, the process proceeds to step 102, and if the first abnormality flag is in the on state, the process proceeds to step 106.

In step 106, it is judged that the inspection device 2 has abnormally operated, and it is impossible to determine whether the inspection device 2 is a good product or a defective product because the inspection of the inner coating of the metal container is not properly performed due to this abnormal operation. It is determined that the product is a metal container. That is, when the current detection state in the transient region α is incorrect, it is determined that the inspection device 2 has malfunctioned.

Next, at step 102, it is judged that the second abnormality flag is in the ON state. If this condition is satisfied, the routine proceeds to step 106, and if not, the routine proceeds to step 103. .. That is, if the second abnormality flag is in the off state, the process proceeds to step 103, and if the second abnormality flag is in the on state, the process proceeds to step 106.

Therefore, in step 106 after step 102, similarly to the above, it is determined that the inspection device 2 has abnormally operated, and it is determined that the abnormal operation does not properly inspect the inner surface coating of the metal container, and it is a non-defective product. It is judged that the container is a metal container that cannot be determined whether it is defective or defective. That is, if the current detection state in the transient region α is inappropriate, or if the current detection state in the transient region α is proper but the current detection state in the steady-state region β is incorrect, the inspection device It is judged that 2 has operated abnormally.

Then, in step 103, the ON state of the defect determination flag is determined, and if this condition is satisfied, the process proceeds to step 105, and if not, the process proceeds to step 104. That is, if the defect determination flag is in the off state, the process proceeds to step 104, and if the defect determination flag is in the on state, the process proceeds to step 105.

In step 104, it is judged that the inspection device 2 has operated normally, and the inspection is performed under the normal operation of this inspection device. No defect is detected in the inner coating, and the metal container is a good product. Deciding.

That is, since the current detection state in the initial transient region α is determined to be proper, the first abnormality flag is maintained in the off state, and the subsequent current detection state in the region β in the steady state is also maintained. Since the second abnormality flag is also maintained in the off state because it is determined to be proper, the inspection device 2 is determined to have properly detected the current in the entire inspection region including the region α and the region β. It is judged to have operated normally.

Under the normal operation of the inspection apparatus 2 as described above, a detection current indicating that the inner surface coating is defect-free is obtained, and the defect determination flag is maintained in the OFF state. While securing the metal container, it can be judged that the inner coating of the metal container is a non-defective product.

Further, the normal operation of the inspection device is judged and guaranteed by the current detection state in the transient region α indicating the defect-free state of the inner surface coating and the current detection state in the steady state region β. The operation guarantee of the device 2 can be sufficiently ensured, and the non-defect determination of the inner coating is performed in the current detection state in the transient region α and the current detection state in the steady region β, so that it is a good product. The reliability assurance of the quality of will be further improved.

In step 105, it is judged that the inspection device 2 has operated normally, and the inspection is performed under the normal operation of this inspection device, and a defect is detected in the inner coating.
We judge that the metal container is defective.

That is, since the current detection state in the initial transient region α is determined to be proper, the first abnormality flag is maintained in the OFF state, and the subsequent current detection state in the region β in the steady state is also maintained. Since the second abnormality flag is also maintained in the off state because it is determined to be proper, it means that the current detection in all the inspection regions is properly performed, and it is determined that the inspection device 2 normally operates. .

Under the normal operation of such an inspection apparatus, a detection current indicating a defect is detected and the defect determination flag is turned on. However, it can be determined that the product is a defective product having a defect in the inner surface coating.

When the determination of the presence / absence of a defect in the inner coating film 4 is completed as described above, and the determination of whether the inner coating film inspection apparatus itself is operating normally is finished, the voltage application is stopped. At the same time, the inspection water 17 is discharged. That is, the lower seal sleeve 99 of the sealing jig 33 is lowered to open the drain port 95e to which the small diameter opening 80 of the metal container body 3 is connected, and the inspection water 17 is drained from the drain channel 9.
It passes through 5d and is discharged from the metal container body 3.

Here, the connection of the three-way valve (not shown) connected to the drain pipe 115 is switched to the side of the pressurized air source (not shown), and pressurized air is supplied from the pressurized air source. The pressurized air reaches the inside of the bottle-type can body 1 through the drain pipe 115, the drain passage 114, and the overflow outlet 113. Therefore, the pressurized air increases the discharging speed of the inspection water 17 from the inside of the bottle-type can body 1, and the drainage channel 9 of the sealing jig 33.
The test water is smoothly discharged to the outside after passing 5d.

The pressurized air supplied from the pressurized air source into the bottle-shaped can body 1 accelerates the discharge of the inspection water 17 from the inside of the bottle-shaped can body 1, and when the discharge of the inspection water 17 is completed, Release air is supplied to the air supply pipe 119, and the upper seal sleeve 98 rises vertically.
The pressing of the upper seal rubber 96 by the upper seal sleeve 98 is released, the elastic deformation of the upper seal rubber 96 is released, and the sealing of the large-diameter opening 5 of the bottle-type can body 1 by the upper seal rubber 96 is released.
Then, the operation of the upper cylinder mechanism 9A (see FIG. 2) raises the insertion head 100, and the insertion head 100 is retracted to the outside of the bottle type can body 1.

After that, the bottle-shaped can body 1 and the sealing jig 33 relatively move in the axial direction of the bottle-shaped can body 1, and the small-diameter opening 80 of the bottle-shaped can body 1 and the lower seal rubber 97 adhere to each other. The state is released, and the small-diameter opening 80 is closed by the sealing jig 33.
Exit from the inside of the cap 95a.

Next, the bottle type can body 1 is transferred to a water droplet removing station (not shown), and the water droplets in the bottle type body 1 are removed at the water droplet removing station. The bottle type can body 1 is transferred to a drying station (not shown), and the bottle type can body 1 is dried.

In this way, the bottle type can body 1 for which the drying operation in the drying station has been completed is conveyed to the subsequent step by the conveying device. When the inspection station K1 determines that the inner coating 4 is defective, that is, the bottle-shaped can body 1 that is determined to be a defective product is not transferred to the water drop removing station, but is directly discharged. Discharge to the outside of the line by means of the discharge mechanism 59, or discharge to the outside of the line by means of the discharge mechanism 59 after passing through at least one of the water drop removing station and the drying station. The bottle-shaped can body 1 that has been determined to have not been inspected by the operation is directly discharged from the discharge mechanism 59, like the defective product.
Alternatively, the control of passing through at least one of the water drop removing station and the drying station and then discharging out of the line is selected.

As described above, according to the inner surface coating film inspection apparatus of this embodiment, when inspecting the inner surface film 4 of the bottle type can body 1 for defects, pure water having an electrochemical property is used. Since it is used as the inspection water 17, it is not necessary to provide a cleaning step after the inspection, and the number of steps can be reduced. Further, in order to inspect the inner surface coating of the metal container body for defects, in the enamellator method using an electrolytic solution, since the residue such as the electrolytic solution adhered to the metal container body, the metal residue Although there is a possibility that traces of adhesion may remain on the container body and the filling material filled in the metal container body may be contaminated, the inspection water 17 is used according to the defect detection method and inspection device of the embodiment. By the bottle type can body 1
Since there is no residue, it is possible to completely eliminate the possibility that the filling in the bottle type can body 1 is contaminated by the residue. This is particularly effective when the filling material of the bottle type can body 1 is a food or drink.

It should be noted that the inspection water 17 does not impair the flavor of the filling material filled in the bottle type can body 1,
Moreover, it is possible to mix an alcohol that does not leave a residue or a trace of adhesion which is a problem in food hygiene. Further, this alcohol evaporates by performing a predetermined heat treatment and has no influence on the food and drink filled in the bottle type can body 1.

Further, the inspection water 17 is filled over the area to be inspected in the space formed between the inner surface coating 4 of the metal container body 3 and the outer surface of the insertion head 100. Specifically, the inspection water 17 is filled in the region to be inspected, which faces the inner coating 4, and the region to face the current detection electrode 19. Therefore, even if the inner surface shape of the metal container body 3 is complicated, for example, even if there are spiral irregularities,
The inspection water 17 can be evenly distributed over the area of the surface of the inner surface coating 4 to be inspected, and the inner surface coating 4 and the inspection water 17 can be brought into contact with each other. Therefore, the presence / absence of a defect in the inner surface coating 4 of the metal container body 3 having a complicated inner surface shape can be easily and quickly determined, and the determination accuracy can be improved.

Furthermore, when the detected current monitoring means recognizes that the inspection device 2 itself for the inner coating 4 is abnormal, it instructs the metal container to be ejected, so various factors that make the conventional inspection incomplete. Problems due to incomplete inspection based on can be avoided in advance. That is, it is possible to recognize that the inspection is incomplete due to an abnormal operation of the inspection device 2 and to eject the metal container to be inspected when the inspection is incomplete as an incomplete inspection product. It is possible to prevent an erroneous product determination or a defective product determination of the metal container due to the inspection, and improve the reliability of the inner surface coating inspection.

In this way, the presence / absence of a defect in the inner surface coating 4 is detected based on the detected current value while confirming that the inspection device 2 itself is functioning normally each time the defect in the inner surface coating 4 is detected. Therefore, the reliability of the inspection by the inner surface coating inspection device can be improved. That is, since the inspection device performs the inspection operation while being monitored for each inspection of each metal container, the reliability of the inspection of the non-defective product performed under the normal operation is ensured, and the inspection result is the metal container. It is possible to improve quality assurance as a non-defective product.

Furthermore, according to the present embodiment, since the current detected for the inner surface coating inspection is shared and the program for judging the detected state of the current is added, the apparatus is not added separately. It can be used at a low cost, can be used for an inspection device having a conventional configuration that does not use the present invention, and can be applied to a wide range of device configurations. That is, using the electrical configuration for detecting defects in the inner surface coating, only the determination means for determining the operation of the inspection device from the detected current is added, that is, the self-diagnosis function is added to the inspection device. Since it is only present, it can be applied to an inspection device having a conventional configuration.

Further, since the state of transient current detection immediately after the inspection voltage is applied is monitored to constantly check whether or not the inspection device itself is functioning normally, the inspection device is operating normally. When it is determined that the inspection operation is proper, the reliability of the non-defective determination of the metal container based on the current detection determination that the inner surface coating is defect-free can be further improved.

That is, when a metal container having a defect-free inner surface coating is inspected, the normal operation of the inspection device is checked by the transient current detection state indicating the defect-free inner surface coating. , The reliability of the inspection will be improved. Furthermore, when inspecting a metal container in which the inner surface coating has a defect, the normal operation of the inspection device is checked by the current detected in the steady region indicating the defect state of the inner surface coating. The reliability of the inner surface film inspection,
The quality assurance as the inspection result is further improved.

Here, the correspondence between the structure of the embodiment and the structure of the present invention will be described. The bottle type can body 1 corresponds to the metal container of the present invention, and the metal container body 3 is the metal container of the present invention. Of the inner surface coating film inspection apparatus 2 corresponds to the inner surface coating film inspection apparatus of the present invention, the current detection electrode 19 corresponds to the conductive member of the present invention, and the inspection water 17 corresponds to the inspection water of the present invention. However, the pump 16, the flow control valve 18, the test water inlet 15, and the water supply channel 109 correspond to the test water supply device of the present invention, and the electric circuit formed by the DC power source 22, the switch 21, and the edge electrode 20 is the present invention. Corresponding to the voltage applying device of the ammeter 23 and the data processor 24.
Corresponds to the current detector of the present invention, the edge electrode 20 corresponds to the electrode of the present invention, the insertion head 100 corresponds to the insertion member of the present invention, and the electronic control device 58 corresponds to the inner surface film defect determination means of the present invention. It corresponds to the first current determination means, the second current determination means, and the determination means that are the detected current monitoring means.

In addition, although the present embodiment is provided with a structure for judging the inrush current in the transient region and a structure for judging the detected current in the steady region, the level of the applied voltage and the concentration of the test water Depending on various conditions such as the thickness and the thickness of the inner surface coating film thickness, it is possible to appropriately select and apply only one of the configurations.

Furthermore, in the present embodiment, from the experimental results, the period for determining the inrush current is 30 ms from the start of voltage application, the inrush current determination level is 5000 to 6000 μA,
The period for determining the fluctuation width of the steady detection current is 500 ms starting from 30 ms after the start of voltage application, the judgment level of the fluctuation width that is the difference between the maximum and minimum detection current values is 200 μA, and the inner coating 4 The period for determining a defect is 500 ms starting from 400 ms after the start of voltage application.
Up to 100-2, the standard value for determining defects in the inner coating 4 is
Although it is set to 00 μA, the material and thickness of the metal container,
Depending on various conditions such as the composition and orientation of the inner surface coating, the thickness, the specific resistance value that is the electrical property of the test water, the applied voltage value of the inspection device, the distance between the can body and the electrode, etc. You can change and set it.

In this embodiment, a DC power supply device is used as a power supply for inspection, but a power supply device in which AC is added to DC may be used.

The metal container to which the present invention is applied is not limited by its inner and outer shapes as long as it is a metal container having at least one end open. For example, a two-piece can of regular type or bottle type, both ends of which are opened. Any of a bottle type two-piece can and a three-piece can can be used.

[0131]

As described above, according to the invention of claim 1, the conductive member is inserted into the inside of the metal container having the opening formed at least at one end, and the inner surface coating of the metal container is present. The electrode is brought into contact with a portion not to be filled with test water over a region facing the inner surface coating of the metal container and a region facing the conductive member, and a voltage is applied between the conductive member and the electrode to pass the test water. Since the presence or absence of defects in the inner coating is detected based on the electric current flowing through it, even if the inner surface of the metal container has a complicated shape, the highly watered test water can infiltrate along the complicated inner shape. The accuracy of detecting defects in the inner coating is improved. Therefore, regardless of the inner surface shape of the metal container having the opening formed at least at one end,
It is possible to improve the defect detection accuracy of the inner coating.

Further, when the detected current monitoring means recognizes that the inner surface coating inspection device itself has an abnormality, it instructs the metal container to be ejected, so that the inconvenience caused by the incomplete inspection based on various factors in the related art is caused. It can be avoided in advance. In other words, it is possible to recognize that the inspection is incomplete due to an abnormal operation of the inspection device and to discharge the metal container that is the object of inspection when the inspection is incomplete as an unfinished inspection product. When the inspection is not completed, the determination of non-defective products and the determination of defective products can be prevented, and the reliability of the inspection can be improved. Further, in this way, the presence or absence of defects in the inner coating based on the detected current value is detected while confirming that the inner coating inspecting device itself is functioning normally for each detection of the inner coating defects. The reliability of the inspection by the film inspection device can be improved. That is, since the inspection operation is performed while monitoring the operation abnormality of the inspection apparatus, the inspection is performed after confirming that the inspection apparatus operates normally, the reliability of the inspection is ensured, and the inspection result is The quality assurance of the metal container as a non-defective product can be improved.

According to the second aspect of the present invention, the inner surface coating film inspection apparatus itself functions normally to perform the inner surface coating film inspection operation by monitoring the current detection state pattern by the detected current monitoring means. Since it is possible to detect the presence or absence of a defect in the inner surface coating film based on the detected current while checking, it is possible to improve the reliability of the inspection by the inner surface coating film inspection apparatus. That is, since the inspection operation is performed while constantly monitoring the operation abnormality of the inspection device, the reliability of the inspection of the non-defective product when the normal operation is confirmed is secured, and the quality assurance of the metal container as the non-defective product is improved. can do.

According to the invention of claim 3, the same effect as that of the invention of claim 1 or 2 can be obtained, and the transient current state at the start of the voltage application is monitored and detected in the transient state. When a current value is smaller than a predetermined current value, a configuration is added that determines that the inspection device is abnormal, so that when the inspection device is determined to be operating normally, a transient state is detected. Since the current is properly detected, it means that the detected current reflecting the defect state of the inner surface coating is properly measured, and the defect determination of the inner surface coating of the metal container based on such detected current is performed. The reliability can be sufficiently ensured, and the quality assurance of the non-defective non-defective metal container can be improved.

According to the invention of claim 4, the same effect as that of any one of claims 1 to 3 can be obtained, and
The detection state of the current in the region that is in the steady state after the region that is in the transient state is monitored, and the difference between the maximum value and the minimum value of the current detected in the steady region is, When it is larger than the predetermined current fluctuation width value,
By adding a configuration that determines that the inspection device is abnormal, when it is determined that the inspection device operates normally,
Since the detection current in the steady state is properly detected, in this case, the detection current reflecting the defect state of the inner coating is properly measured. In addition, the reliability of the defect determination of the inner coating of the metal container can be sufficiently ensured, and the quality assurance of the non-defective metal container as a good product can be improved.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing an inspection device used in an inspection station and a bottle type can body to be inspected according to an embodiment of the present invention.

FIG. 2 is a block diagram mainly showing a control circuit of the inspection device of the present invention.

FIG. 3 is an embodiment of the present invention, (1) is a schematic view showing a detection current pattern in which the inner surface coating is defect-free, and (2) is a schematic view showing a detection current pattern in which the inner surface coating is defective.

FIG. 4 is an embodiment of the present invention, including (1) to (5)
FIG. 6 is a schematic diagram showing a detected current pattern that reflects an abnormal operation of the inspection apparatus due to various different factors.

FIG. 5 is a flow chart showing an embodiment of the present invention, showing a procedure for determining a determination flag which serves as a basis for determination of operation abnormality of an inspection apparatus and defect determination.

FIG. 6 is a flow chart showing a procedure of determining the inspection result of the metal container and determining whether the inspection device is normal or abnormal according to the embodiment of the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Bottle type can body, 2 ... Inner surface coating inspection apparatus, 3 ... Metal container body part, 5 ... Large diameter opening part, 4 ... Inner surface coating, 1
4 ... Inspection water supply pipe, 17 ... Inspection water, 18 ... Flow control valve, 19 ... Current detection electrode, 20 ... Edge electrode, 2
2 ... DC power supply, 21 ... Switch, 23 ... Ammeter, 5
8 ... Electronic control device, K1 ... Defect inspection station.

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Masafumi Nagasawa             Yamato 5-5-1 Nishihashimoto, Sagamihara City, Kanagawa Prefecture             Seikan Co., Ltd. Technology Development Center (72) Inventor Shigeya Kawai             Yamato 5-5-1 Nishihashimoto, Sagamihara City, Kanagawa Prefecture             Seikan Co., Ltd. F-term (reference) 2G060 AA10 AA11 AE03 AF01 AG11                       EA04 EA07 EB06 HC07 HC10                       KA12 KA14

Claims (4)

[Claims] 1. An inner surface coating inspection of a metal container for detecting a defect of the inner surface coating in a metal container provided with an opening formed at least at one end and a non-conductive inner surface coating applied to an inner peripheral surface. In the device, a conductive member to be inserted into the inside of the metal container from the opening portion, and the metal container and the conductive member are relatively moved, so that the conductive member is inside the metal container, Insert the conductive member into the metal container in a non-contact manner,
And, a drive device for retracting the conductive member from the inside of the metal container to the outside, an electrode that contacts a portion of the metal container where the inner surface coating does not exist, and the conductive member is inserted into the metal container. And a test water supply device for filling test water over a region facing the inner coating and the conductive member inside the metal container, and a region facing the inner coating inside the metal container and the Over the region facing the conductive member, under the state of being filled with test water, a voltage is applied between the conductive member inserted inside the metal container and the electrode in contact with the metal container. A voltage applying device to be applied, an ammeter for detecting a current flowing through inspection water by applying a voltage by the voltage applying device, and a steady state among the currents detected by the ammeter Comparing the current value of the region to be in a state with the preset good product current value, if the detected current value exceeds the preset good product current value, the inner coating of the metal container is defective. There is an inner surface film defect determining means to determine that there is, a detection current monitoring means for monitoring the detection state of the current, when the inner surface film defect determining means determines that the inner surface film has a defect, or the detected current An inner surface coating inspection device for a metal container, comprising: a determination unit that outputs a signal instructing the discharge of the metal container when the monitoring unit recognizes that the current detection state is abnormal. 2. An inner surface coating inspection device for a metal container for inspecting the inner surface coating of a metal container provided with a non-conductive inner surface coating, wherein the metal portion of the metal container has one polarity and is arranged in the metal container. An application device that applies an arbitrary voltage with the conductive member having the opposite polarity, an inspection water supply device that fills the metal container with inspection water having an electrochemical property required for the inspection, and the inspection water Is filled, based on the current detected when the voltage is applied by the applying device, the inner surface coating film defect determination means for determining a defect of the inner surface coating film, the detection state pattern of the current is identified, the inspection device And a detection current monitoring means for determining the inspection operation of the metal container. 3. The detected current monitoring means monitors a current detection state in a transitional region where voltage application is started, and a maximum current value detected in the transitional region is predetermined. The inner surface coating film inspection device for a metal container according to claim 1 or 2, further comprising: first current determination means for determining that the inspection device itself has an abnormality when the current value is smaller than the current value. 4. The detected current monitoring means monitors a current detection state in a steady state region after the transitional state region ends, and the current is detected in the steady state region. A second current determination means for determining that the inspection device itself is abnormal when the difference between the maximum value and the minimum value of the current is larger than a predetermined current fluctuation width value is provided. Item 5. The inner surface coating film inspection device for a metal container according to any one of Items 1 to 3.