JP2003065992A - Equipment and method for inspecting inner surface coating of metal container - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an equipment and a method for inspecting the inner surface coating of a metal container in which the reliability of inspection can be enhanced at the time of detecting a defect in the inner surface coating of a metal container having an opening at at least one end thereof by grasping an appropriate filling state of inspection water throughput the inspection and the quality of product can be guaranteed furthermore. SOLUTION: After a metal container 1 is filled with inspection water 17, an arbitrary voltage is applied between one electrode, i.e., the metallic part 3 of the metal container 1 applied with a nonconductive inner surface coating, and an opposite electrode, i.e., a conductive member 19 disposed in the metal container 1 and the inner surface coating 4 of the metal container 1 is inspected by detecting a current generated upon application of the voltage. In such an equipment 2 for inspecting the inner surface coating 4 of the metal container 1, a passage 113 is provided from a position below the water level of inspection water 17 filling the metal container to cover a region of the inner surface coating being inspected toward a position above the water level, and water level detecting means 25 and 26 are provided in the passage 113 at the same position as the water level of the inspection water 17 or at an upper position.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a scratch generated on a non-conductive inner surface coating made of synthetic resin or the like which covers the inner surface side of a conductive metal container made of a surface-treated steel plate or an aluminum alloy plate. The present invention relates to an apparatus and method for detecting defects such as cracks, cracks, and pinholes.

[0002]

2. Description of the Related Art In order to prevent a metal container from being corroded by its filling, the inner surface of the metal container is coated with a non-conductor made of a synthetic resin such as a thermosetting resin coating film or a thermoplastic resin film film. It has been widely performed conventionally. The material and thickness of the coating applied to the inner surface of the metal container and the method of forming the coating are determined by the properties of the filler in 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 subsequent processing steps of the metal container. Then, when the filling is sealed inside the metal container while leaving the defects of the inner surface coating, the metal constituting the metal container is corroded by the filling and corrosion holes are generated, or the metal is used in the metal container. There is a possibility that the metal contained therein may be eluted into the filling to impair the flavor of the filling. 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, an electrolytic solution (for example, an aqueous sodium chloride 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, a sodium chloride aqueous solution or a sodium sulfate aqueous solution is used as an electrolytic solution, so that it is a metal container with a one-end opening that has been inspected to find that there is no defect in the inner surface coating. However, the electrolyte adhered to the inner surface of the metal container may corrode the inner surface of the metal container with the passage of time, so the metal container used for the inspection will be discarded. There is. Therefore, if this method is adopted for 100% inspection of metal containers with one-end opening,
Since a dedicated cleaning process is required to completely remove the highly corrosive electrolyte from the inside of the metal container, the inspection process is complicated and the manufacturing cost of the metal container is increased.

[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. According to the method and apparatus described in this publication, by using pure water as the conductive liquid, the metal container is naturally dried, or air (air at room temperature or warm air) is blown on the metal container. It is said that after the drying, the traces of water are not left on the inner surface coating of the metal container after the drying, the metal container can be returned to the state before the inspection, and the cleaning step is not required.

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 container having the opening formed at least at one end is In the case of a complicated shape that is difficult to reach (for example, a shape with a small diameter in the middle or a shape with spiral irregularities near the opening on one end side), the conductive liquid is used to coat the inner surface. May not evenly spread over the surface of. As a result, there is a possibility that the defect detection accuracy of the coating may be reduced.

Therefore, a defect detecting apparatus and method which can eliminate the above-mentioned problems and improve the defect detection accuracy of the inner coating by using conductive inspection water instead of the above-mentioned conductive brush are described. , Japanese Patent Application 2001-
The present applicant has already filed No. 132403.
That is, this application is to fill the inside of the metal container with inspection water, and apply the inspection voltage from the inside of the metal container to the inner surface coating film through the filled inspection water. By detecting the defect of the inner surface coating of the metal container based on the value, it is possible to detect the defect of the inner surface coating irrespective of the inner surface shape of the metal container having the opening at least at one end.

[0009]

However, in the method and apparatus described in the above publication, the inner coating film of the metal container must be maintained during the inspection unless the filling amount of the inspection water is maintained at the specified amount. There was a problem that the inspection of was inaccurate.

That is, if the test water is insufficient during the test, the water level of the test water supplied to the inside of the metal container becomes low, and a part of the inner surface coating which the test water cannot contact occurs. As a result, the portion of the inner surface coating that was not in contact with the inspection water was not subjected to the coating inspection, but it was not clear with the conventional inspection method whether or not there was such a fact. .

For example, in the case of a metal container having openings at both ends, when the metal container is set in an inspection device and inspected, a sealing treatment for sealing a small-diameter opening which is a lower opening of the metal container. The lower seal rubber, which is a tool, deteriorates due to deterioration of the seal material, lowering of the lower seal rubber's elasticity, wear, etc., or of the curl part formed by wrapping the cylindrical end of the small diameter opening Due to poor molding or deformation, the small-diameter opening on the lower side of the metal container cannot ensure a completely sealed state, and the filled test water leaks out from the poorly sealed part, causing a shortage of test water during the inspection. Occur.

Further, due to a physical defect in the supply system for supplying the inspection water to the inspection device, that is, clogging or leakage of the inspection water flow path such as the water supply pipe and the water supply passage constituting the supply system, or control of the supply system. Due to such a problem, that is, due to a malfunction due to malfunction of the flow control valve, flow sensor, check valve, etc., less than the preset prescribed amount of test water was supplied to the metal container, A shortage of test water occurs.

Further, even after the water level detecting device (sensor) detects and confirms that the inspection water is filled in the metal container according to the regulation, the inner surface film of the metal container is detected for defects. In addition, the inspection water may leak from the metal container due to the above-mentioned defective sealing, and the inspection water may be insufficient during the inspection.

When the shortage of test water occurs in this way, a portion of the inner surface coating which is not in contact with the test water is generated, so that the defect of the inner surface coating of the metal container cannot be accurately detected.

That is, if there is a defect in a portion of the inner surface coating that the inspection water should originally come into contact with, which is not in contact, the defect in this portion cannot be detected, and the inner surface coating has a defect. Although it is a non-defective product, defects are overlooked, and the inspection result of the inner surface coating is determined to be a normal product, which causes a problem that the inspection of the inner surface coating cannot be accurately determined.

Further, for example, the inspection device is arranged on the outer periphery of a disk-shaped pedestal which can be rotationally driven and whose upper surface is axially supported in a horizontal state, and a metal container to be inspected is externally supplied to the inspection device and the pedestal is supplied. In the case of a turret inspection device that is configured to inspect the inner surface coating while transporting the metal container in the circumferential direction with the rotation drive of, the amount of inspection water to fill the metal container in order to speed up the inspection device. The test water is filled in and out of the metal container as quickly as possible by, for example, filling the test water as specified up to a position slightly above the large-diameter open end of the metal container. Need to go to. However, if the water surface of the filled test water is open to the atmosphere side and communicates with it, the water surface of the test water becomes wavy, and a portion of the inner surface film that does not come into contact with the test water is generated. There is a possibility that the inner surface coating inspection of the above is not performed accurately.

That is, when the metal container is inspected by the turret inspection device, the metal container is moved along an arcuate path so that the inspection water in the metal container and the inside of the metal container moves from its rotation center to the metal container. Because the centrifugal force acts on the test water from the radius and the rotation speed, which are the distances, if this turret inspection device rotates its pedestal at a relatively high speed, or if the rotation speed of the pedestal of the inspection turret is the same. , If the pedestal radius is relatively large and the turning radius distance to the metal container is large, and if they are improperly combined to increase centrifugal force, the inspection of the metal container and its interior Since a relatively large centrifugal force acts on the water, the water surface of the test water filled in the metal container cannot be maintained in a horizontal state, and the water surface of the test water is opposite to the radial center direction around the rotation axis. Toward direction, it will be inclined.

That is, in the turret inspection device,
Due to the centrifugal force associated with the rotational transfer operation during the inspection, the water level of the inspection water in the metal container is always higher on the outer peripheral side opposite to the central axis side of the inspection turret, while the inspection turret's water level is higher. The water level of the test water is always lower on the rotation center axis side. As a result, during the inspection by the turret inspection device, even if a prescribed amount of inspection water is filled, it is near the large-diameter opening end above the metal container, and the inspection turret rotation center axis side of the metal container. There is a possibility that a portion where the test water does not come into contact may occur in the inner surface coating on the inner peripheral side that faces toward.

Therefore, also in this case, if there is a defect in the portion of the inner surface coating film which is not in contact with the inspection water, this defect cannot be detected, and it is judged as a normal product although it is a defective product having a defect. An erroneous judgment will occur in the inspection of the inner surface coating.

The present invention has been made in view of the above circumstances, and a metal having an opening formed at least at one end can be obtained by grasping that the inspection water is properly filled during the inspection. It is an object of the present invention to provide a metal container inner surface coating inspection device and inspection method capable of improving the reliability of inspection and the assurance of product quality in detecting defects in the inner surface coating of a container.

[0021]

Claims Means for Solving the Problems and Their Actions
Of the invention, the metal portion of the metal container coated with a non-conductive inner surface has one polarity, the conductive member placed in the metal container has the opposite polarity, after the inspection water is filled into the metal container. ,
Applying an arbitrary voltage between both poles, detecting the current generated at the time of application, in the internal coating film inspection device of the metal container for inspecting the internal coating film based on the detected current value, the inspection target of the internal coating film of the metal container and The test water filled so as to cover the area to be covered with water, the passage provided upward from the water surface position above the water surface position, and the water surface position of the test water at the same height in the passage in the vertical direction. And a water level detecting means provided at the upper position or the upper position.

According to the first aspect of the present invention, during the inspection in which the voltage is applied, it is detected that the inspection water is filled so as to cover the area to be inspected of the inner surface coating of the metal container. It is possible to inspect the inner surface coating while confirming by means, and it is confirmed that the inspection water is properly filled during the inspection, and if the inner surface coating is detected as defect-free, the inner surface It is guaranteed that the area of the coating to be inspected has been inspected, and it can be determined that the metal container is a good product. On the other hand, if it is confirmed that the inspection water is insufficient during the inspection and it is detected that the inner surface coating is defect-free, some parts of the inner surface coating have not been inspected and the metal container has not been inspected. Since it can be determined that it is a product, it is possible to prevent erroneous inspection in this case.

According to a second aspect of the present invention, the metal container is provided with an opening formed at least at one end and a non-conductive inner surface coating formed on the inner peripheral surface of the metal container from the opening to the inside of the metal container. The conductive member to be inserted and the metal container and the conductive member are relatively moved so that the conductive member is inserted into the metal container in a non-contact state with respect to the metal container. And, a driving device for retracting the conductive member from the inside of the metal container to the outside, an electrode contacting a portion of the metal container where the inner surface coating does not exist, and the conductive member inside the metal container. A test water supply device that is inserted and fills test water over a region facing the inner surface coating inside the metal container, and a region facing the inner surface coating inside the metal container and the conductive member. A voltage applying device that applies a voltage between the conductive member inserted inside the metal container and the electrode that is in contact with the metal container while being filled with inspection water over the entire area. And a current detector that detects a current between a conductive member and an electrode when a voltage is applied by the voltage applying device, and a discriminating device that discriminates a defect in the inner surface coating film from the current detected by the current detector. In a device for inspecting an inner surface of a metal container provided with, a flow rate control valve for controlling a flow rate of test water supplied to the inside of the metal container; and a flow control valve provided between the flow rate control valve and the test water supply passage. A flow rate sensor for detecting a flow rate of the test water supplied to the container, the conductive member, a passage provided so as to communicate the inside and the outside of the metal container, and a passage provided at a predetermined position of the passage, Provide inside metal container The water level detection sensor for detecting the water level of the inspection water to be detected, the detected flow rate measured by the flow rate sensor, and a preset flow rate are compared, and when the detected flow rate reaches the preset flow rate, the inspection is performed. An electronic control device that outputs a signal to stop the supply of water and that determines whether or not a preset amount of test water has been supplied to the metal container from the detection state of the water level detection sensor is provided. It is characterized by.

According to the invention of claim 2, in addition to the same effect as that of the invention of claim 1, a flow rate sensor for detecting the flow rate of the test water supplied to the metal container is provided. Even if it can be detected that the specified amount has been supplied,
If the amount supplied to the body of the metal container by the water level detection sensor does not reach the predetermined amount, it is possible to determine that the inspection water supply route or the inspection water leakage of the metal container itself has occurred if detected. .

According to the third aspect of the present invention, the metal portion of the metal container provided with the non-conductive inner surface coating has one polarity, the conductive member disposed in the metal container has the opposite polarity, and the test water is made into metal. After filling the container, apply an arbitrary voltage between both electrodes,
Detecting a current generated at the time of application, the inner surface coating is inspected based on the detected current value, in the inner surface coating inspection method for a metal container, wherein the inspection is performed while transferring the metal container through a predetermined path, wherein the metal container is the When the filled test water surface is maintained in a predetermined horizontal state when it is transferred through the route, it is monitored from different directions around the entire circumference inside the metal container, and when an abnormal water level is detected. Is an inspection method characterized by determining that the inspection of the inner coating is not completed.

According to the third aspect of the present invention, it is monitored whether the water surface of the filled test water is maintained in a predetermined horizontal state. Therefore, when the transfer route changes irregularly or the transfer speed is changed. When non-constant acceleration / deceleration occurs and when these are combined, centrifugal force and acceleration are complicated or interact with each other in the metal container, and even if the water level of the inspection water in the metal container changes, Since it is possible to detect changes in the water level over the entire circumference in the metal container, it is possible to determine whether or not an uninspected part has occurred due to insufficient water level of the inspection water in the area to be inspected for the inner surface coating, and It is possible to prevent the non-tested product of the inner surface coating, which is not maintained in the horizontal state, from being treated as a non-defective product.

According to a fourth aspect of the present invention, the metal portion of the metal container provided with the non-conductive inner surface coating has one polarity, the conductive member arranged in the metal container has the opposite polarity, and the test water is a metal. After filling the container, apply an arbitrary voltage between both electrodes,
Detecting the current generated at the time of application, the inner surface coating is inspected based on the detected current value, in the method for inspecting the inner surface coating of a metal container, wherein the inspection is performed while transferring the metal container along a path on the circumference of a predetermined radius, When the metal container is transferred through the path, the centrifugal force acting on the metal container passes through the line of action passing through the center of the metal container and the line along the inner circumference of the metal container. When an abnormal water level is detected by detecting the water level of the test water at or near the center of the circumference of the route, or at a place far from the center of the circumference of the transfer route, or both. Is an inspection method characterized by determining that the inspection of the inner coating is not completed.

According to the fourth aspect of the present invention, when the metal container is transferred along the circumferential transfer path, the centrifugal force applied to the metal container causes the filled test water to have the lowest water level or its location. Since the water level in the vicinity, or the place where the water level rises the most or in the vicinity of the water level, or both, is detected, it is possible to detect an uninspected part on the inner coating of the metal container due to insufficient water level of the inspection water. Can be determined,
It is possible to prevent the non-tested product of the inner surface coating whose test water is not maintained in a predetermined horizontal state from being treated as a non-defective product.

[0029]

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 structure 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 an enlarged sectional view showing the vicinity of the opening of the bottle-type can body 1 in FIG. 1. FIG. Note that FIG.
FIG. 3 is a circuit block diagram showing an electrical configuration of the inspection device 2 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. And a shoulder portion 7 formed into a circular shape in section from the body portion 6 side, and a small diameter for connecting to the shoulder portion 7 and for attaching a screw cap (not shown) 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. In the first method, for example, a paint such as an epoxy-phenol-based paint, an acrylic-modified epoxy-phenol-based paint, or an epoxy-urea-based paint is liquid-applied on the inner peripheral surface of the tubular container-shaped metal container body 3. By spraying in the state of, and baking the paint dry
This is a method for producing a bottle-type can body 1 having an inner coating 4. In the second manufacturing method, a resin-coated metal plate is manufactured by sticking or extrusion-coating a thermoplastic resin film such as polyester resin or an inner resin film on the surface of the metal plate. As the thermoplastic resin film, a polyester-based film, a polypropylene-based film, a nylon-based film, or the like is used, and as the inner surface resin film, an oriented crystal inner surface resin film or an amorphous structure film is used.
Next, the resin-coated metal plate is drawn or redrawn or ironed to form a cylindrical can body with a bottom, and then the bottom side of the bottom can body is drawn and smoothed several times. The small-diameter mouth-neck portion 8 and the shoulder portion 7 are formed by performing the chemical conversion process, and 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 wound outside. The inner surface coating 4 is formed by molding the curl portion 81, forming a screw portion 82 thereunder, and forming an annular protrusion 83 for fixing a breaking band of a cap (not shown) having a tamper evidence mechanism. It is a method for manufacturing the bottle type can body 1 having

On the other hand, the inspection device 2 for inspecting the metal container body 3 has the bottle-shaped body 1 through the large-diameter opening 5.
It has an insertion head 9 which is an insertion member to be inserted into the inside of. Further, in the present embodiment, the insertion head 9 is arranged so as to face substantially the entire inner peripheral surface to be inspected for the presence or absence of a defect in the inner surface coating 4 of the metal container body 3 with a constant interval. For example, a non-conductive material such as a synthetic resin is used as an internal material, and a small-diameter cylindrical protrusion 12 is provided on one end side of the cylindrical body 10 via a shoulder 11 having an arcuate longitudinal section. Has been formed.

The insertion head 9 corresponding to the conductive member of the present invention is smaller than the shape formed by the inner peripheral surface of the metal container body 3 of the bottle-shaped can body 1 to be inspected and has a similar shape. . That is, the insertion head 9 connects these parts with a hollow shaft-shaped body 10 having a smaller diameter than the metal container body 3, a small-diameter shaft portion 12 having a smaller diameter than the small-diameter neck 8 of the bottle-type can body 1. It has a gentle shoulder 11 which is A current detection electrode 20 is provided so as to cover almost the entire outer peripheral surface of the insertion head 9.

Therefore, since the current detecting electrode 20 is smaller than the inner peripheral surface of the metal container body 3 and formed in a shape similar to the inner peripheral surface, the current detecting electrode 20 and the metal container body 3 are formed. The inner surface has a substantially constant interval (for example, 2 to 3).
mm) and are opposed to each other.

The current detection electrode 20 is used for the insertion head 9
Since it is formed in a state of covering 95% or more of the outer peripheral surface facing the inner peripheral surface of the metal container body 3, the inner peripheral surface of the metal container body 3 is commercialized as a bottle-shaped can. Almost the entire circumferential surface faces the current detection electrode 20. Particularly, of the outer peripheral surface of the insertion head 9, it is preferable to cover the portion of the body 6 facing the inner surface coating 4 of the body portion 6 which is susceptible to defects due to the ironing process, by covering the outer surface of the insertion head 9 substantially with the current detection electrode 20. 100% is the current detection electrode 20
It is more preferable to cover with.

The current detecting electrode 20 is made of stainless steel, aluminum alloy, or the like, and is connected to the positive electrode of the DC power source 22.

Further, the current detection electrode 20 and the DC power source 22
On the connection line with the positive electrode of,
A switch 21 that can be connected is provided.
1 is connected to an electronic control unit 58 which will be described later, and the switching operation of disconnection / connection by the switch 21 is performed by the electronic control unit 5.
It is controlled by 8.

Furthermore, the insertion head 9 is supported by a cylinder (not shown), and the cylinder is driven by the cylinder to move the insertion head 9 in the axial direction of the bottle type can body 1.
Specifically, it reciprocates vertically.

The insertion head 9 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 103 and a piston rod 104.
And the piston rod 104 thereof projects toward the tip side (lower side in FIG. 1). A core rod portion that penetrates the center portions of the upper seal sleeve 103 and the piston rod 104 in the axial direction is integrated with the insertion head 9, and the base end portion of the insertion head 9 (clamping cylinder 102).
Side end portion), the upper seal rubber 105 and the guide ring 10 are arranged in this order from the piston rod 104 side.
6 is fitted.

The upper seal rubber 105 has an outer diameter slightly smaller than the inner diameter of the large-diameter opening 5 of the metal container body 3, and is deformed so as to bulge to the outer peripheral side when pressed by the piston rod 104. As a result, the large diameter opening 5 of the metal container body 3 is clamped. Therefore, 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 105 so as to face the upper seal rubber 105 in the radial direction.

Therefore, by inserting the large-diameter opening 5 of the body part 3 of the metal container between the upper seal rubber 105 and the receiving ring 107, and then pressing the upper seal rubber 105 with the piston rod 104, the metal container The large-diameter opening 5 of the body 3 is clamped by the upper seal rubber 105 and the receiving ring 107.

An edge electrode 19 is provided between the receiving ring 107 and the upper seal rubber 105 and the clamping cylinder 102. The edge electrode 19 has a ring shape and a plate shape. That is, the edge electrode 19 projects like a brim from the outer peripheral surface of the body portion 10, and the outer diameter of the edge electrode 19 is set to be larger than the outer diameter of the bottle type can body 1. Therefore, the metal container body 3 is attached to the upper seal rubber 105.
The large-diameter opening 5 of the metal container body 3 comes into contact with the edge electrode 19 when fitted to the outer peripheral side of the.

Further, as shown in FIG. 3, the edge electrode 19
Is connected to the negative electrode of the DC power supply 22. Then, by turning on / off the switch 21, the current detection electrode 20
The voltage applied to the inner surface film 4 is lower than the withstand voltage of the inner surface film 4 (this voltage is the type of the inner surface film 4, the thickness of the inner surface film 4,
Depending on the crystallinity of the inner surface coating 4 and the like, for example, 2
00 to 700V).

An ammeter 23 is provided on the connection line between the negative electrode of the DC power source 22 and the edge electrode 19.
The output line of the ammeter 23 is connected to the data processor 24, and the output line of the data processor 24 is connected to the electronic control unit 58. Further, by analyzing the current value measured by the ammeter 23, the electronic control unit 58 determines whether the inner surface coating 4 has a defect.

The receiving ring 107 is the edge electrode 1
9 is fixed to the tip of the clamp cylinder 102 so as to be sandwiched between the clamp cylinder 102 and the tip of the clamp cylinder 102.

The guide ring 106 arranged on the opposite side of the piston rod 104 with the upper seal rubber 105 interposed therebetween is a so-called receiving member which produces a reaction force when the upper seal rubber 105 is pressed by the piston rod 104. Has become.

Further, the outer peripheral surface of the guide ring 106 is connected to the current detecting electrode 2 from the upper seal rubber 105 side.
It is formed in a taper shape whose diameter gradually decreases toward the 0 side. Therefore, the insertion head 9 is attached to the metal container body 3
When inserting into the inner periphery of the metal container, the large-diameter opening 5 of the metal container body 3 is guided along the tapered outer peripheral surface of the upper seal rubber 105, so that the insertion container 9 is axially shaped. Since the axes of the body 3 are made to coincide with each other, they are always coincident with each other on the same axis so that they can be clamped as described later.

The parts other than the electrodes 19 and 20 and the water level detection electrodes 25 and 26 described later are made of a non-conductive material.

On the other hand, below the insertion head 9, a sealing jig 33 for opening and closing a small diameter opening 80 formed on the lower end side of the small diameter neck 8 is installed. This sealing jig 33
Is a drainage channel 95 that can be closed or opened at will.
d is provided, and this drainage channel 95 is provided above it.
A close contact portion is provided which communicates with d and is connected to the lower end of the metal container body 3.

That is, the block 95c is formed in a short cylindrical shape having a diameter at least larger than the outer diameter of the small-diameter opening 80, a recess having a predetermined diameter is provided at the center of the upper portion, and a passage extending from the recess to the side surface is formed. ing. Further, on the upper side of the block 95c, a substantially wide ring-shaped housing 95b having a drainage port 95e of a predetermined diameter is provided, and a drainage channel 95d extending from the drainage port 95e to the side surface of the block 95c is formed. Is connected to a water pipe (not shown).

The drain port 95 of the housing 95b is also
The e can be opened and closed arbitrarily by the lower seal sleeve 99. That is, the lower seal sleeve 99
Has an upper part formed in a large diameter having a hemispherical shape larger than the inner diameter of the drainage port 95e, and a lower part formed in a long rod shape on the same axis as the diameter center of the drainage port 95e. , The upper part of the block 95c facing the drain port 95e
It is located inside. Also, the lower seal sleeve 99
The lower end portion of the air cylinder mechanism projects downward from the block 95c through a through hole provided in the block 95c.
(Not shown). 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. The protrusion and the lower seal rubber 97 are interposed to guide the small diameter opening 80 of the metal container body 3. 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 constructed as described above
Is supported by a cylinder mechanism (not shown) so that it can be arbitrarily moved up and down, and the cylinder mechanism drives the sealing jig 33 up and down to move the small diameter opening of the metal container body 3. The lower seal rubber 97 is closely attached to 80, and the drainage channel 9 provided in the sealing jig 33.
The drain port 95e of 5d can be communicated.

Therefore, according to the sealing jig 33 configured as described above, when the defect of the inner coating 4 is detected,
The lower seal rubber 97 is in close contact with the small diameter opening 80 of the metal container body 3, and the small diameter opening 80 which is the lower opening of the metal container body 3 is communicated with the drainage channel 95d of the sealing jig.
The lower seal sleeve 99 is driven upward, and the upper end portion of the lower seal sleeve 99 closes the drain outlet 95e of the drainage channel 95d, thereby sealing the small diameter opening 80, and the metal container body 3 through the small diameter opening 80. Therefore, the inspection water 17 is prevented from flowing out. On the other hand, when the inspection water 17 is drained after the inspection, the lower seal sleeve 9
9 is driven downward, the drain port 95e is opened, and the inspection water 1
7 passes through the drainage channel 95d and is discharged from the metal container body 3.

The lower seal rubber 97, the lower seal sleeve 99, the cap 95a and the housing 95b are made of a non-conductive material such as synthetic resin.

Along the central axis (not shown) of the insertion head 9 described above, the water supply passage 1 is provided from the upper portion 9A of the insertion head 9.
09 is formed, and this water supply passage 109 opens at the tip of the small diameter shaft portion 12 of the tip 9B below the insertion head 9, while branching from the middle and opening at a location near the shoulder 11. Note that the check valve 1 is provided in the middle of the water supply passage 109.
10 are provided.

In addition, the inspection water 17
The water supply pipe 111 for supplying the
Is connected to a pure water supply pump 16 (see FIG. 3) via an ion exchange processor 17A (see FIG. 3). Then, known ion exchange treatment is applied to the pure water pumped up by the pure water supply pump 16 (see FIG. 3),
The test water 17 whose specific resistance is adjusted to a predetermined value is manufactured. The inspection water 17 is sent to the water supply passage 109 via the water supply pipe 111.

The pure water supply pump 16 and the water supply pipe 111
A flow rate control valve 18 is provided in the flow path between and.
The flow rate control valve 18 controls the flow rate of the test water 17 supplied to the water supply passage 109.

In the middle of the water supply pipe 111, a flow rate sensor 11 for detecting the amount of water supply that has passed through the flow rate control valve 18.
Two are provided. Therefore, when the metal container body 3 passes through the predetermined position and the test water 17 is supplied, the flow rate sensor 112 supplies the amount of the test water 17 supplied between the insertion head 9 and the metal container body 3. Is detected and the supply of the test water 17 is stopped based on the detection result, so that the filling amount is not excessive.

A plurality of overflow outflow passages 113 are provided at the upper end portion of the insertion head 9 slightly distal to the guide ring 106 (lower side in FIG. 1). Is communicated with a drainage channel 114 formed by penetrating the portion in the axial direction.

Further, as shown in an enlarged view in FIG. 2, the air escape groove 1 which extends in the radial direction on the lower surface side of the upper seal rubber 105 and communicates with the drainage channel.
A plurality of 14A are provided, and the notch groove 114 communicating with the air escape groove 114A is also provided on the outer peripheral portion of the guide ring 106.
B is provided.

The upper end 9A of the insertion head 9 has a through hole 1 for communicating the air escape groove 114A with the drainage channel 114.
14C is formed.

Therefore, when the test water 17 is supplied to the inside of the metal container, the air existing inside the metal container is pushed up as the water level of the test water 17 rises. The air is discharged from 114B to the outside through the air escape groove 114A of the upper seal rubber 105, the through hole 114C, and the drainage channel 114. For this reason, the test water 17 does not collect air in the upper part of the inside of the metal container, and the inspection water 17 is
In the non-contact state, the water is filled up to the position close to the end of the large diameter opening inside the metal container, and the inspection water 17 can surely contact the inspection target region of the inner surface coating 4.

On the other hand, one end of a drain pipe 115 protruding outside the insertion head 9 is connected to the drain passage 114. A three-way valve (not shown) is connected to the other end of the water distribution 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 17 is supplied by switching the three-way valve, the inside of the metal container body part 3 is opened to the outside atmosphere and communicates with the inspection water 17 inside the metal container body part 3. At the time of discharging, a pressurized air source (not shown) and the inside of the metal container body 3 can be communicated with each other. Therefore, when the inspection is completed, pressurized air is supplied from the pressurized air source, and the pressurized water is used to push out the inspection water 17 from the metal container body portion 3, thereby eliminating the unnecessary inspection water 17 It is designed so that it can be quickly discharged from the metal container.

Further, a water level detection device for detecting the water level (water surface position) of the inspection water 17 supplied into the metal container body 3 is provided at a predetermined position of the overflow outflow passage 113, and this water level detection The device includes a water level detection electrode 25,
26 are mainly configured. That is, in the insertion direction of the insertion head 9 into the inside of the metal container body 3 inside the insertion head 9, the metal container body 3 is attached to the insertion head 9 and the upper and lower edges of the large-diameter opening end are vertically moved. The water level detection electrodes 25 and 26 are attached to the overflow outflow passage 113 at the same height position in the direction or above and in the vicinity thereof. The water level detection electrodes 25 and 26 are formed of a conductive material such as stainless steel, aluminum alloy, platinum, or carbon. The water level detection electrodes 25 and 26 are provided at different positions in the axial direction of the insertion head 9. The water level detection electrode 26 is provided at a position closer to the drainage channel 114 than the water level detection electrode 25. Each water level detection electrode 25, 26 is formed in a strip shape and is attached over the entire circumference of the overflow outflow passage 113.

The water level detection electrodes 25, 26 for inspecting the inner coating 4 with the bottle-shaped can body 1 stationary.
The mounting position of may be at the same height position in the vertical direction as the large-diameter opening end.

The one water level detection electrode 25 is connected to the positive electrode of the DC power supply 27, and the other water level detection electrode 26 is connected to the negative electrode of the DC power supply 27. An ammeter 28 is provided on the connection line between the water level detection electrode 26 and the negative electrode of the DC power supply 27.

Further, the water level detecting electrode 25 and the DC power source 27
On the connection line with the positive electrode of,
A switch 29 that can be connected is provided, and this switch 2
9 is connected to an electronic control unit 58 which will be described later, and the switching operation of disconnection / connection by the switch 29 is performed by the electronic control unit 5.
It is controlled by 8.

In FIG. 1, reference numeral 25a indicates an electric wire for a plus electrode connected to the water level detection electrode 25, reference numeral 26a indicates an electric wire for a minus electrode connected to the water level detection electrode 26, and reference numeral 116 indicates. The electric wire for the positive electrode connected to the current detection electrode 20 is shown, and the reference numeral 117
Represents a wire for a negative electrode connected to the edge electrode 19, reference numeral 118 represents a clamp air supply pipe for the clamp cylinder 102 and the upper seal sleeve 103, and reference numeral 119 represents the clamp cylinder 102 and the upper seal sleeve. The release air supply pipe for 103 is shown. Although not shown in FIG. 1, the insertion head 9 is attached with an electric wire forming a part of an electric circuit including the detection electrode 20, the edge electrode 19, and the DC power supply 22. Further, in FIG. 3, the inspection device 2 is configured by the respective mechanisms provided in the region surrounded by the alternate long and short dash line showing the inspection device 2.

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. The transport device 56 that performs the operation described above is driven and controlled by the electronic control device 58. The transfer device 56 includes a known actuator (not shown) such as an electric motor and a cylinder, a turntable operated by these actuators, a belt conveyor,
A known mechanism such as a chuck is provided. Furthermore, various sensors 5 for photoelectrically or mechanically detecting the position, movement, stop, etc. of the bottle-shaped can body 1 in each station or between each station.
7, and 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 electrically connected to the electronic control unit 58.

Furthermore, each part of the inspection device 2, and
An electronic control unit 58 is provided for controlling the operation of the mechanical device interlocking with the inspection device 2. This electronic control unit 58
Is composed of an arithmetic processing unit (CPU or MPU), a storage device (RAM and ROM), and a microcomputer mainly including an input / output interface. Then, the electronic control unit 58 includes the data processor 2
4 signals, ammeters 23 and 28 signals, various sensors 57
Signal is input. On the other hand, from the electronic control device 58, a command signal for controlling each cylinder (not shown), a signal for controlling the transport device 56, a command signal for controlling the flow rate adjusting valve 18, a command signal for controlling the discharge mechanism 59, and the like are given. It is being output.

An inspection operation for detecting the presence / absence of a defect in the inner surface coating 4 of the bottle type can body 1 by the inner surface coating inspection apparatus 2 configured as described above will be described.

First, the bottle-shaped can body 1 coated with the inner surface coating 4 is carried into 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. It

Then, as shown in FIG. 1, the bottle-shaped can body 1 is in a predetermined inspection position with the axis of the bottle-shaped can body 1 oriented vertically and the small-diameter mouth / neck part 8 oriented downward. The sealing jig 33, which is held at the standby position immediately below the bottle-shaped can body 1 in this state, is driven upward from the lower position by a predetermined amount. Then, when the sealing jig 33 comes into contact with the small-diameter mouth / neck portion 8 of the bottle-shaped can body 1 in a predetermined manner, the relative movement between the bottle-shaped can body 1 and the sealing jig 33 is ended (that is, stopped), The small-diameter neck 8 is closed by the sealing jig 33. That is, the lower seal rubber 97 of the sealing jig 33 comes 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 connected to the discharge passage of the sealing jig 33. The lower seal sleeve 99 of the sealing jig 33 is driven upward, and the drain port 95e of the discharge flow passage is closed by the upper end of the lower seal sleeve 99.

By sealing the small diameter opening 80 as described above, the setting of the bottle type 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 9 starts descending due to the operation of the cylinder. Then, the insertion head 9 passes through the large-diameter opening portion 5 and enters the inside of the bottle-shaped can body 1, and as shown in FIG. 1, the edge electrode 19 causes the large-diameter opening portion 5 of the metal container body portion 6 to move. The insertion head 9 stops at the point of contact with the peripheral edge of the. Therefore, the periphery of the large-diameter opening 5 is the edge electrode 1
It comes into contact with 9 and becomes electrically conductive. In this way, a space is formed between the outer surface of the insertion head 9 and the inner coating 4 when the insertion head 9 is inserted into the bottle-shaped can body 1 and stopped. The plurality of inspection water inlets 15, the current detection electrodes 20, the plurality of air openings, and the inner coating 4 face this space.

Further, when the insertion head 9 is lowered toward the inside of the metal container body 3 as described above, if the axes of the two are slightly deviated, a large diameter opening is formed in the outer peripheral surface of the guide ring 106. The edges of part 5 contact. Since the outer peripheral surface of the guide ring 106 is formed in a tapered shape, the edge of the large-diameter opening 5 is guided by the tapered surface, and the metal container body 3 and the insertion head 9 are aligned on the same axis. And set in the fitted state.

In this state, when the clamping air is supplied, the upper seal sleeve 103 descends vertically,
Since the upper seal rubber 105 is compressed in the axial direction, it is elastically deformed so as to project outward in the radial direction. Therefore, the end of the large-diameter opening 5 is sandwiched and clamped between the deformed upper seal rubber 105 and the receiving ring 107. In this state, the insertion head 9 and the metal container body 3 are arranged on the same axis, and the insertion head 9 is smaller (smaller in diameter) than the metal container body 3, so that there is a constant gap between the two (one example As 1
˜4 mm, preferably about 2 to 3 mm), and the current detection electrode 20 and the inner peripheral surface of the metal container body 3 face each other with a gap therebetween.

Then, by the opening operation of the flow rate control valve 18,
When the supply of the test water 17 from the water supply pipe 111 is started, the test water 17 pushes open the check valve 110, and the test water 17 is supplied from the opening of the insertion head 9 into the metal container body 3.

In this case, the overflow outflow passage 113 is communicated with the outside by the three-way valve, and the air existing in the space between the insertion head 9 and the metal container body 3 is discharged into the overflow outflow passage 113 and the outside. The inspection water 17 is discharged to the outside from the drainage channel 114, and the space is smoothly filled.

The water level of the test water 17 in the space rises and the switch 29 is connected to the water level detection electrodes 25, 26.
To the water level detection electrodes 25, 26
When the water level is such that both of them come into contact with the inspection water 17, the water level detection electrodes 25 and 26 are brought into conduction via the inspection water 17. Therefore, the ammeter 28 detects a current corresponding to the conduction, and the inspection water 17 is detected based on the detection signal of the ammeter 28.
It is determined by the electronic control device 58 that the prescribed amount of water has been injected into the space, and the supply of the test water 17 is stopped by the closing operation of the flow rate control valve 18. That is, the test water 17 is injected from the large-diameter open end of the metal container body 3 to the same height position in the vertical direction or to a position higher than the same height.

As another means for stopping the supply of the inspection water 17, the amount of the inspection water 17 flowing inside the water supply pipe 111 is
The flow rate is detected by the flow rate sensor 112, and the detected flow rate is a predetermined value, that is, the insertion head 9 and the metal container body 3.
When the flow rate is such that the test water 17 fills the space volume between the test water 17 and the inner peripheral surface thereof, the supply of the test water 17 is stopped by the closing operation of the flow rate control valve 18.

In this case, the inspection water 17 may momentarily overflow to the outside from the overflow outflow passage 113. However, the inspection water 17 to be filled between the insertion head 9 and the inner peripheral surface of the metal container body 3 is not discharged. Flow rate sensor 11
2, the inspection water 17 is sufficiently filled up to the vicinity of the large-diameter opening 5 of the metal container body 3, and the inspection water 17 is applied to the region of the inner surface coating 4 of the metal container body 3 to be inspected. Water level detection electrodes 25, 2
6 is configured to confirm. As a result,
As described above, since the water level of the inspection water 17 is confirmed before the inner surface film inspection, when it is confirmed that the water level is normal, the water up to the vicinity of the large diameter opening 5 of the metal container body 3 is confirmed. This means that the defect detection was reliably performed over the region of the inner surface coating 4 to be inspected.

Further, by providing a timer for measuring the elapsed time from the start of water supply, even if a predetermined time has elapsed after the start of water supply, the inflow amount supplied to the metal container body 3 is predetermined. Water level detection electrode 25,
When it is possible to determine that No. 26 is in the undetected state, the inspection water 17 leaks from the location where the flow rate sensor 112 is provided on the supply path of the inspection water 17 to the location downstream of the metal container body 3 side. Or the leakage of the test water 17 from the metal container body 3 occurs due to a poor seal of the metal container body 3 itself. Therefore, the electronic control unit 58 can determine such a leak of the test water 17 from the signals output from the timer, the flow rate sensor 112, and the water level detection electrodes 25 and 26, and issue an alarm.

As a result, even if the flow rate sensor can detect that a predetermined amount has been supplied, if the inflow amount supplied into the metal container body 3 does not reach the predetermined amount after the timer has timed, the water level is detected. The inspection water is not detected by the electrodes 25 and 26, and it can be determined that an inspection water leak has occurred in the supply path of the inspection water 17 or the metal container body 3 itself. 17
It can be judged that the cause of the lack of water is the possibility of leakage of inspection water.

Since pure water having an electrochemical property is used as the inspection water 17, even if the inspection water 17 is removed by heating and drying the metal container body portion 3 after the inspection, Since no residue is generated on the inner peripheral surface of the part 3, the inspection water 17
The additional steps such as washing after the removal of are eliminated.

As described above, when it is confirmed that the space between the insertion head 9 and the metal container body 3 is normally filled with the prescribed amount of test water 17, the switch 29 is turned off,
The electric circuit for detecting the water level is cut off, and the inspection of the inner coating 4 is executed.

That is, by turning on / off the switch 21, the inspection voltage is applied to the current detection electrode 20 for a predetermined time. This voltage is controlled to a voltage lower than the withstand voltage of the inner coating 4, for example, 200V to 700V.

As described above, since the inner surface coating 4 which is electrically non-conductive is formed on the inner peripheral surface of the metal container body 3, when the inner surface coating 4 is not defective. Causes no current other than the current due to discharge (for example, when the current value when there is a defect is 100 to 200 μA or more, the current value when there is no defect is 50 μA or less). On the other hand, when a defect such as a pinhole or a crack is generated in the inner coating 4, the metal base of the metal container body 3 and the inspection water 17 are directly contacted with each other, and the current detection electrode 20 and the metal base are inspected water. 1
It is in a conductive state through 7.

The defects generated in the inner surface coating 4 include cracks,
There are defects such as scratches, pinholes, and network defects with mesh-like cracks on the surface, and metal fragment adhesion defects in which minute metal fragments generated during the molding of the bottle-type can body 1 stab the inner surface coating 4. 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, in the case of a network defect, such as when the crack does not reach the metal base, or in the case of a metal piece attachment defect, the metal piece stuck to the inner surface coating 4 does not reach the metal base. Even if the inspection water 17 and the inspection water 17 are not energized, if the inner surface coating 4 is damaged, a current due to discharge flows. Even in the defect-free inner surface coating 4, a current due to discharge flows though it is smaller than that in the defective portion. As a result, the current associated with applying the DC voltage as described above increases.

Therefore, by applying a voltage,
An electric circuit closed by the current detection electrode 20, the edge electrode 19 and the inspection water 17 is formed, and the electric current passing through the defect, the discharge current passing through the defect, and the electric discharge passing through the inner coating 4 having no defect are formed in this electric circuit. A current such as a current flows.

At this time, the inner peripheral surface of the metal container body 3 to be inspected for the presence of defects and the current detection electrode 20 are opposed to each other at a constant interval over substantially the entire surface thereof. Regardless of the location of the defect, the defect and the current detection electrode 20
And the distance is almost the same. Therefore, the variation in the current value due to the variation in the distance between the defect and the current detection electrode 20 is eliminated, so that the defect detection accuracy can be improved.

However, since the thickness of the inner surface coating 4 is different in the vicinity of the large-diameter opening 5 of the metal container, the body 3, the shoulder 7, the small-diameter mouth / neck 8, etc., a slight accuracy error occurs.

The current thus generated is obtained by the ammeter 23.
Is detected as a current in the range of μA to mA,
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 signal and sends the processed signal to the electronic control unit 58. Then, the electronic control unit 58, based on a predetermined reference value (for example, a current value corresponding to 6 mA by the enamellator method), if the measured current value is less than the reference value, there is no defect, or more than the reference value. If so, it is determined that there is a defect, and it is determined whether or not there is a defect occurring in the inner coating 4, and the metal container body 3
Judge the non-defective product or defective product.

The inspection time for the presence or absence of defects in the inner surface coating 4, that is, the time for applying a voltage is preset to a predetermined time, and after that time, the switch 21
Is turned off and application of the inspection voltage is stopped. Further, the area of the inner surface coating film 4 to be inspected by the inspection device 2 of the present embodiment is an area other than the pressing surface of the upper seal rubber 105.

Then, the water level of the inspection water 17 filled in the metal container body 3 after the inspection is confirmed.

That is, after the inspection, if the water level of the inspection water 17 in the space remains the same as that before the inspection, both the water level detection electrodes 25 and 26 are in contact with the inspection water 17, so that before the inspection. Similarly, the water level detection electrodes 25 and 26 become conductive via the test water 17. Therefore, the ammeter 28 detects the current for confirming the water level according to this conduction,
Based on the detection signal of the ammeter 28, the electronic control unit 58 can determine that the inspection water 17 has been kept in the specified amount in the space throughout the entire process of inspecting the inner surface film to which the voltage is applied. it can.

As a result, before and after the inspection of the inner coating 4, when it is confirmed that the metal container body 3 is properly filled with the prescribed amount of the inspection water 17, the inspection is performed during the inspection. It is ensured that the inspection water 17 is spread over and brought into contact with the region to be inspected of the inner surface coating 4 of the metal container body 3, and thus the reliability of the inspection in the inspection device 2, that is, the quality assurance of the product. Can be improved.

On the other hand, after the inspection, if the water level of the inspection water 17 in the space is lower than that before the inspection, at least the water level detection electrodes 25, 26 do not come into contact with the inspection water 17, so the water level detection electrode 25, 26 does not become conductive via the test water 17. Therefore, the ammeter 28 did not detect the current for confirming the water level, and the inspection water 17 was not maintained in the specified amount in the space throughout the entire process of the inner surface film inspection to which the voltage was applied, and some abnormality occurred. Can be determined by the electronic control unit 58.

After the inspection as described above, the inspection water 17
If it is determined that the amount of water is less than the specified amount, the portion of the inner surface coating 4 which is not in contact with the inspection water 17 is generated during the inspection of the inner surface coating 4. Since the defect detection of the coating film 4 has not been performed, the electronic control unit 58 distinguishes the metal container body 3 into the uninspected products, and similarly to the defective metal container body 3 in which the defect is detected. , Will be excluded from subsequent lines.

Therefore, even if there is a defect in the portion of the inner surface coating film 4 which is not in contact with the inspection water 17, this defect cannot be detected, and the inspection result is the same as that of a defect-free product without defect. Since it is obtained, it can be avoided that it is determined as a normal product as it is, that is, an erroneous misjudgment occurs in the inspection of the inner coating 4.

A flow rate sensor is provided in the supply path of the test water 17, the flow rate of the test water 17 is discriminated by the flow rate sensor, and the metal container body 3 is filled with a prescribed amount of the test water 17. If there is a total of 2 before and after the inspection
The water level may be confirmed by the water level detection electrodes 25 and 26 only after the inspection, instead of performing the water level confirmation once.

During the inspection of the inner surface coating to which a voltage is applied, the electric circuit for detecting the water level is cut off by turning off the switch 29, and the water level detecting electrode 2 from the DC power source 27 is cut off.
The current supply to 5, 26 is stopped to prevent the current for detecting the water level from affecting the detection current for inspecting the inner surface film that also flows through the inspection water 17.

That is, it is determined whether the voltage for detecting the water level is energized through the test water 17 filled between the water level detecting electrodes 25 and 26 (whether the circuit is in an ON state or an OFF state). Therefore, it is not necessary to accurately measure the amount of electricity passed between the electrodes 25 and 26, and it is not necessary to apply a high voltage between the electrodes 25 and 26, so a low voltage is sufficient.
On the other hand, the inspection voltage of the inner coating 4 is
Voltage lower than withstand voltage of, for example, 200V to 700
Although it is V, which is a relatively high voltage, it is necessary to accurately measure the energization amount because it is determined based on the detected energization amount whether or not the inner coating 4 has a defect. Therefore, the simultaneous application of the inspection voltage for the inner coating 4 and the voltage for detecting the water level has an adverse effect on the inner coating inspection which requires accurate measurement of the amount of energization, and an accurate defect inspection of the inner coating 4 cannot be performed. Therefore, the inspection voltage of the inner coating 4 and the water level detection voltage are not applied at the same time.

It should be noted that the water level detection voltage is a low voltage, and since it is merely determined whether or not power is supplied through the inspection water 17 filled between the water level detection electrodes 25, 26, a plurality of voltages are required. It is also possible to provide a water level detection sensor including a combination of the water level detection electrodes 25 and 26 and simultaneously apply a voltage to these water level detection sensors for simultaneous use.

When such a water level confirmation process is completed,
The small-diameter opening 80 is unsealed, and the test water 17 inside is discharged. That is, the lower seal sleeve 99 is driven downward to open the drain port 95e, and the inspection water 17 passes through the drain channel 95d and is discharged from the metal container body 3. At this time, the drainage pipe 115 and the pressurized air source are communicated with each other by the three-way valve, and the pressurized air is blown out from the overflow outflow passage 113, whereby the discharge speed of the inspection water 17 can be increased.

Further, the sealing jig 33 is the sealing jig 33.
The cylinder mechanism is driven to move downward from the upper position and retracted to the standby position directly below the bottle can body 1.

Further, release air is supplied to the clamping cylinder 102. The release air lifts the upper seal sleeve 103 in the vertical direction, whereby the upper seal rubber 105 returns to its original shape by elasticity, and the clamp of the large diameter opening 5 is released. Then, finally, the insertion head 9 is moved upward along the axial direction of the bottle type can body 1 by the cylinder drive of the cylinder supporting the insertion head 9, and the bottle type can body 1 is moved. Exited from within.

After removing the insertion head 9 from the body part 3 of the metal container, the non-defective bottle-shaped can body 1 in which no defect was detected was sent to the process line of the normal product, and the defect was detected. It is judged that the defective bottle-shaped can body 1 or the inner surface coating 4 is not contacted with the inspection water 17 over the area of the inner surface coating 4 to be inspected. The bottle can 1 is removed from the line.

The bottle-shaped can body 1 determined to be a non-defective product is transferred to the water drop removing station, the water drops are removed, and after the drying operation in the drying station is completed, the transport device 5
It is conveyed to the subsequent process by 6.

At the inspection station K1,
Bottle-shaped can body 1, which is determined to have a defect in the inner coating 4,
That is, the bottle-shaped can body 1 that is determined to be a defective product, or the inspection water 17 does not come into contact with the inspection target area of the inner surface coating 4 and accurate defect detection of the inner surface coating 4 cannot be performed. The bottle-shaped can body 1 that has been inspected as
It is discharged to the outside of the line by the discharging device 56 without being transferred to the water drop removing station, or is discharged to the outside of the line by the discharging device 56 after passing through at least one of the water drop removing station and the drying station. Either of these controls is selected. (Other embodiments)

In the inspection apparatus 2 of the above-described specific example, an example in which the inner surface coating 4 applied to the inner peripheral surface of the metal container body 3 is inspected while the bottle type can body 1 is stationary has been described. However, in this example, while transferring the bottle type can body 1,
An example of performing the inspection will be described.

That is, the turret inspection device 15 of this example.
As shown in FIG. 4, the reference numeral 2 indicates the outer circumference of a disk-shaped pedestal 152a whose upper surface is pivotally supported in a horizontal state.
A plurality of inspection devices are arranged to supply the bottle-shaped can body 1 to be inspected to the turret inspection device 152 from the outside, and the pedestal 15
The inner coating 4 is inspected while the bottle-shaped can body 1 is transported in the circumferential direction in accordance with the rotational driving of 2a.

Numeral 153 is a supply conveyor section for receiving the bottle-shaped can body 1 to be inspected from an upstream process and transferring it to the inspection device 2 side, and 151 is a bottle-shaped can body transferred by the supply conveyor section. 1 is a first intermediate transfer section for delivering 1 to the turret inspection apparatus 152, and 154 is a second intermediate transfer section for receiving and transferring the bottle-shaped can body 1 inspected from the turret inspection apparatus 152 or uninspected.
Reference numeral 156 denotes a drying turret unit that receives and transfers the bottle-shaped can body 1 that has been transferred by the second intermediate transfer unit 154 while performing drying processing. It is an intermediate transport section,
7 is a bottle type can body 1 transferred by the third intermediate transfer section.
Is a discharge conveyor section that receives and transfers to the next process. In addition, the third intermediate transfer unit 155 is provided with a bottle-shaped can body 1 that has been inspected and determined to be defective, and an ejection mechanism (not shown) that ejects the bottle-shaped can body 1 that has not been inspected. .

In the turret inspection device 152, a pedestal 152a having a predetermined thickness and formed in a substantially disc shape is rotatably supported with its flat pedestal upper surface in a horizontal state. It is rotatably driven at a predetermined rotation speed by (not shown). A plurality of inspection devices 2 are arranged on the outer circle near the outer periphery of the pedestal 152a at equal intervals, and each inspection device 2 has its associated jigs, pipes, and wires. Is provided, and independent inspection operations are possible.

Further, this turret inspection device 152 is
Along the clockwise rotation direction, the first intermediate transfer unit 15
Starting from the point where the bottle type can body 1 is passed from
A predetermined area is divided into five areas while the end point is the location to be delivered to the intermediate conveyance section 154, and the operations shown in the following order are assigned to each area, and these operations are assigned to each area. By each inspection device 2 passing through
It is running. That is, the inserting operation of the inspection head 9,
It is the filling operation of the inspection water 17, the inspection operation of the inner surface coating 4, the discharging operation of the inspection water 17, and the leaving operation of the inspection head 9. As described above, the water level of the inspection water 17 can be confirmed before and after the inspection operation of the inner surface coating 4. Has been done.

Further, the water level detection electrodes 25 and 26 for confirming the water level of the inspection water 17 are arranged such that when the bottle type can body 1 and the inspection head 9 are moved circumferentially by the turret inspection device 152. 1 and inspection head 9
It is provided at a predetermined position of the inspection head 9 in which the water level of the filled inspection water 17 is likely to be lowered by the centrifugal force applied to.

That is, these water level detection electrodes 25, 2
As shown in FIG. 5, the centrifugal force acting on the metal container body 3 passes through the central axis 3A of the metal container body 3 when the metal container body 3 is transferred along the circumferential path. Line of action A
And a portion C, D where the line B along the inner circumference of the metal container body 3 intersects, the center of rotation of the pedestal 152a (center of the circumference)
It is arranged so as to detect the water level of the test water 17 on the central axis 3A side of the metal container body 3 at the location C near 152A.

That is, these water level detection electrodes 25, 26
In the inspection head 9, below the water surface position of the inspection water 17 filled inside the metal container body 3, and at the center 152A of the circumferential radius to which the metal container body 3 is transferred and the metal container body 3. In the overflow outflow passage 113 having the opening located on the line A connecting to the central axis 3A, the upper and lower portions are vertically arranged at the same height position as the peripheral portion of the large-diameter opening 5 or in a position slightly higher than that. The circumferential direction in which the metal container body 3 is moved by the centrifugal force acting on the metal container when the metal container body 3 is inspected while being transferred on the circumference. It is possible to detect whether or not the water level of the inspection water 17 on the center side of the is decreased.

Further, the inner diameters of the water level detection electrodes 25 and 26 are
The remaining liquid of the inspection water 17 is prevented from adhering by providing the same diameter as the inner diameter of the overflow outflow passage 113 and eliminating the step between the water level detection electrodes 25 and 26 and the inner peripheral surface of the overflow outflow passage 113. I have to.

Therefore, when inspecting the metal container by the turret inspection device 152, the inspection is performed while transferring the metal container on the circumference, so that the metal container and the inspection water 17 therein are moved in an arc shape. The centrifugal force defined by the radius, which is the distance from the center of rotation to the metal container, and the rotation speed causes the turret inspection device 15 to operate.
2 rotates the pedestal 152a at a relatively high speed, or if the pedestal 152a of the turret inspection device 152 has the same rotation speed, the radius of the pedestal 152a is relatively large and the radius of gyration to the metal container is large. , And if they are improperly combined so as to increase centrifugal force, the metal container and the test water in it 1
Since a relatively large centrifugal force acts on 7, the water surface of the inspection water 17 filled in the metal container cannot maintain a horizontal state, and the water surface of the inspection water 17 is opposite to the radial center direction around the rotation axis. Turret inspection device 15 inclined toward the direction
The water level of the inspection water 17 is always low at the position of the metal container located on the inner peripheral side of the second pedestal 152a facing the rotation center axis side. As a result, during inspection by the turret inspection device 152, May cause a portion where the inspection water 17 does not come into contact with the large-diameter open end above the metal container and on the inner surface coating 4 on the inner peripheral side of the metal container toward the inspection turret rotation center axis. Therefore, even if there is a defect in the portion of the inner surface coating 4 which the inspection water 17 has not contacted, this defect cannot be detected, and the inspection result is the same as the normal product even though it is a defective product with a defect. Although an erroneous judgment may occur in the inspection of the coating film 4, since it is possible to detect that the water level of the inspection water 17 has decreased in such a case, it is not possible to inspect the metal container body 3 in which the water level decrease has been detected. Distinguished as finished product, inner coating That inspection misjudgment of results can be avoided in advance.

As in the above-described embodiment, also in this embodiment, the metal container body 3 is appropriately filled with the prescribed amount of inspection water 17 before and after the inspection of the inner coating 4. If it is confirmed that the inspection water 17 is applied to the area of the inner surface coating 4 of the metal container body 3 to be inspected during the inspection.
Since it is ensured that all the components are in contact with each other, the reliability of the inspection in the inspection device 2, that is, the quality assurance of the product can be improved.

In the above embodiment, when the bottle type can body 1 and the inspection head 9 are moved along the circumferential transfer path by the turret inspection device 152, they are added to the bottle type can body 1 and the inspection head 9. By the centrifugal force, the water level of the filled test water 17 is detected to be the substantially lowest in the water level. On the contrary, the water level of the filled test water 17 is substantially the highest. You may comprise so that the water level of the part to detect may be detected. Therefore, in this case, if the rise of one of the water levels is detected by the centrifugal force, it means that the fall of the other water level is detected, so that the same action and effect as above can be obtained. . It should be noted that if the configuration is such that the water levels of the filled test water 17 at both locations are detected, the water level state of the test water 17 can be monitored even more reliably.

Further, the horizontal state of the water surface of the test water 17 filled with a prescribed amount may be monitored. For example, in the inspection head 9, the surface of the inspection water 17 and the inspection head 9
Along the outer peripheral line of the inspection head 9 in contact with the outer peripheral surface of, a plurality of water level detection sensors including the above water level detection electrodes 25 and 26 are provided separately from each other, and each water level detection sensor is A configuration may be used in which a detection current is passed to detect the water level. Therefore, when the water surface of the inspection water 17 is horizontal, all combinations of the water level detection electrodes 25 and 26 come into contact with the inspection water 17 and are energized through the inspection water 17, and all the water level detection sensors are in the detection state. Therefore, it can be determined that the surface of the test water 17 is horizontal. On the other hand, when the water surface of the test water 17 is inclined, the single or some combination of the water level detection electrodes 25 and 26 does not come into contact with the test water 17 and cannot be energized through the test water 17, either alone or in some cases. Since the water level detection sensor is not detected, it can be determined that the water surface is inclined. As a result, it is possible to monitor the horizontal state of the water surface of the test water 17 filled with the specified amount.

According to this structure, since the horizontal state of the water surface of the test water 17 is monitored, the transfer route is on the circumference as described above, and the centrifugal force acts from the center of the circle, so that the metal container cylinder In addition to the case where the centrifugal force always acts on the part 3 from the same fixed direction, the transfer path is formed in an elliptical shape,
The water level of the inspection water 17 is complicated because the metal container body 3 is subjected to meandering or even when the transfer speed is not constant, and the fluctuating centrifugal force and acceleration act on the body 3 of the metal container from different directions of the entire circumference. Even if it changes, it is possible to detect such a change in water level over the entire circumference, and it is possible to support various forms of transfer routes, and it is possible to expand the range of application of this configuration. it can.

Although the embodiments of the present invention have been described above, various modifications can be made without departing from the spirit of the present invention.

For example, in each of the above-described embodiments, the parts corresponding to the water level are arranged at a predetermined distance from each other,
Although the water level of the test water 17 is detected by detecting the conduction state between these electrodes via the test water 17, the invention is not limited to this, and an ultrasonic sensor or an X-ray that does not utilize the conductivity of the test water 17, The water level of the test water 17 may be detected by another detection method using a pressure sensor, a photoelectric sensor, or the like.

When the water level of the inspection water 17 is detected by using the sensor that does not pass the current for detecting the water level in the inspection water 17 (excluding the inspection method having strong excitation energy such as X-ray). Since it does not affect the detection current for inspecting the inner surface film flowing through the inspection water 17, it can be configured to constantly detect and monitor the water level during the inspection in which the inspection voltage is applied. Since it is possible to more directly and surely guarantee that the inspection water 17 is filled so as to cover the area to be inspected of the inner coating 4 of the metal container during the inspection, the reliability of the inspection in the inspection device 2 can be improved. That is, the quality assurance of the product can be improved.

As described above, according to the inner surface coating inspection method and the inspection apparatus 2 of this embodiment, when the inner surface coating 4 of the bottle type can body 1 is inspected for defects, it has an electrochemical property. Since the pure water that has been used 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 4 of the metal container body 3 for defects, in an enamellator method using an electrolytic solution or the like, a residue such as an electrolytic solution adheres to the metal container body 3, and therefore the residue remains. Although there is a possibility that a trace of adhesion may remain on the metal container body 3 and the filler filled in the metal container body 3 may be contaminated by the object, according to the inner surface coating inspection method and inspection device of the embodiment, By using the inspection water 17, since there is no residue in the bottle-type can body 1, it is possible to completely eliminate the possibility that the filling in the bottle-type body 1 is contaminated with 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-shaped can body 1 and has a sterilizing effect without leaving a residue or an adhesion mark which is a problem in food hygiene. It is also possible to mix alcohol. Further, this alcohol is evaporated by performing a predetermined heat treatment, and there is no influence on the food or drink filled in the bottle-shaped can body 1.

Further, during the inspection in which the voltage is applied, while confirming by the water level detecting means that the inspection water 17 is filled so as to cover the region to be inspected of the inner coating 4 of the metal container, The inner surface coating 4 can be inspected, and the reliability of the inner surface coating inspection can be improved. That is, when it is confirmed that the inspection water 17 is properly filled during the inspection and it is detected that the inner surface coating 4 is defect-free, it is guaranteed that the area to be inspected of the inner surface coating 4 has been inspected. Then, while it is possible to determine that the metal container is a good product, it is confirmed that the inspection water 17 is insufficient during the inspection, and if the inner surface coating 4 is detected as no defect,
Since a part of the inner coating 4 that has not been inspected has occurred and it is possible to determine that the metal container is an incompletely inspected product, it is possible to prevent erroneous determination in the latter case, and the inner surface coating of the metal container is defective. The reliability of inspection in detection and the assurance of product quality can be improved.

Further, the metal container is moved along the circumferential transfer path, and at least during the inspection, the centrifugal force applied to the metal container causes the filled test water 17 to have the lowest water level or its vicinity. By detecting the water level of one or both of the location or the location where the water level rises most or the location in the vicinity thereof, uninspected due to insufficient water level of the inspection water 17 on the inner surface coating 4 of the metal container. When it is determined that a portion has occurred and an uninspected portion has occurred and the inner surface coating 4 is detected to be defect-free, it is possible to determine that the metal container has not been inspected, so erroneous inspection is prevented in advance. When the normal water level is detected and the inner coating 4 is detected to be defect-free, it is guaranteed that the area of the inner coating 4 to be inspected has been inspected. It can be determined that the goods, it is possible to improve the reliability and product quality assurance of inspection in the defect detection of the inner surface coating of a metal container.

Furthermore, since the water level of the inspection water 17 is confirmed after the inspection of the inner surface coating 4, if it is confirmed that the water level of the inspection water 17 is normal, the inspection of the inner surface coating 4 is performed. Since it can be guaranteed that the amount of inspection water covering the area is ensured during the inspection, it means that the defect detection is surely performed over the area to be inspected of the inner surface coating 4 of the metal container, and the defect of the inner surface coating of the metal container. The reliability of inspection in detection and the assurance of product quality can be improved.

Here, the correspondence between the structure of the embodiment and the structure of the present invention will be described. The metal container body 3 corresponds to the metal container of the present invention, and the inner surface coating 4 corresponds to the inner surface coating of the present invention. The current detection electrode 20 corresponds to the conductive member of the present invention, the test water 17 or the test water 17 mixed with alcohol corresponds to the test water of the present invention, and the flow rate control valve 18 functions as the flow rate control valve of the present invention. The pump 16, the flow rate control valve 18, the inspection water inlet 15, and the water supply passage 109 correspond to the inspection water supply device of the present invention, and the DC power supply 22 and the switch 2 are provided.
1 and the electric circuit formed by the edge electrode 19 correspond to the voltage applying device of the present invention, the ammeter 23 and the data processor 24 correspond to the current detector of the present invention, and the edge electrode 19 corresponds to the electrode of the present invention. Correspondingly, the insertion head 9 corresponds to the insertion member of the present invention, the sealing jig 33 corresponds to the sealing jig of the present invention, the overflow outflow passage 113 corresponds to the passage of the present invention, and the water level detection electrodes 25, 26. , DC power supply 27, ammeter 28, switch 29, electronic control unit 5
8 corresponds to the water level detection device of the present invention, and the flow rate sensor 11
2 corresponds to the flow rate sensor of the present invention, and the cylinder corresponds to the drive device of the present invention.

In the present embodiment, a DC power source is used as the power source for the inspection of the inner surface coating 4 and the power source of the water level detecting device, but a power source in which AC is added to DC is also used. Good.

Further, 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 such as a regular type or a bottle type, or a bottle type with both ends opened. Any of the two-piece can and the three-piece can described above may be applicable.

[0138]

As described above, according to the invention of claim 1, the inspection water is filled so as to cover the area to be inspected of the inner surface coating of the metal container during the inspection in which the voltage is applied. While confirming that the water level is detected,
The inner coating can be inspected, and the reliability of the inner coating can be improved. That is, it was confirmed that the inspection water was properly filled during the inspection,
If the inner coating is detected to be defect-free, it is guaranteed that the area to be inspected of the inner coating has been inspected, and it can be determined that the metal container is non-defective, but there is insufficient inspection water during the inspection. If it is confirmed that the inner coating is defect-free, a part of the inner coating that has not been inspected has occurred,
Since it is possible to determine that the metal container has not been inspected, it is possible to prevent erroneous inspection in this latter case, and to improve the reliability of inspection and the assurance of product quality in detecting defects on the inner coating of the metal container. Can be improved.

According to the invention of claim 2, in addition to the same effect as that of the invention of claim 2, since a flow rate sensor for detecting the flow rate of the test water supplied to the metal container is provided, the flow rate sensor can be used in advance. Even if it can be detected that the specified amount has been supplied,
If it is detected that the amount of inflow supplied to the body part of the metal container by the water level detection sensor does not reach the predetermined amount, it may be determined that the inspection water supply route or the inspection water leak of the metal container itself has occurred. In addition to being able to confirm the lack of test water, it can be determined that the cause of this test water shortage may be test water leakage.

According to the third aspect of the present invention, since it is monitored whether the water surface of the filled test water is maintained in a predetermined horizontal state, the transfer route is irregular or the transfer speed is constant. If not, and when these are combined, even if the water level of the test water changes due to the centrifugal force or acceleration acting on the metal container from different directions all around it, stably or fluctuating. By being able to detect such changes in the water level over the entire circumference, it is possible to support various forms of transfer routes, and it has been confirmed that uninspected parts have occurred in the inner surface coating due to insufficient water level of the inspection water. If it is possible to determine, uninspected parts occur, and the inner surface coating is detected as no defect,
Since it is possible to determine that the metal container has not been inspected, it is possible to prevent erroneous inspections in advance, and it is possible to improve the reliability of inspection and the assurance of product quality in detecting defects in the inner coating of the metal container. At the same time, the range of application of this configuration can be expanded to cases other than the case of a regular transfer path or the case where a constant centrifugal force acts on the metal container.

According to the fourth aspect of the present invention, when the metal container is transferred along the circumferential transfer path, the centrifugal force applied to the metal container causes the filled test water to have the lowest water level or its location. Since the water level is detected in the vicinity, or at the place where the water level rises most or in the vicinity thereof, or both, it is possible that an uninspected part may have occurred on the inner surface coating of the metal container due to insufficient water level of the inspection water. Determined,
If an uninspected part occurs and the inner coating is detected to be defect-free, it is possible to determine that the metal container has not been inspected, so it is possible to prevent erroneous inspections in advance, and the normal water level is maintained. If it is detected that the inner coating is defect-free, it is guaranteed that the area of the inner coating to be inspected has been inspected, and it is possible to determine that the metal container is a good product. It is possible to improve the reliability of inspections and the assurance of product quality.

[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 an enlarged cross-sectional view showing an inspection device used in an inspection station and a vicinity of a large-diameter opening portion of a bottle type can body to be inspected, which is an embodiment of the present invention.

FIG. 3 is a block diagram showing a control circuit of the inspection device of the present invention.

FIG. 4 is another embodiment of the present invention and is a plan view showing the overall configuration.

FIG. 5 is another embodiment of the present invention, which is a schematic diagram illustrating the relationship between centrifugal force and water level detection points.

[Explanation of symbols]

3 ... Metal container body part, 5 ... Large diameter opening part, 4 ... Inner surface coating, 9 ... Inspection head 9A ... Cylinder, 14 ... Inspection water supply pipe, 15 ... Inspection water inlet, 16 ... Pump, 17 ... Inspection water, 18 ...
Flow control valve, 19 ... Edge electrode, 20 ... Current detection electrode, 22 ... DC power supply, 21 ... Switch, 23 ... Ammeter, 25, 26 ... Water level detection electrode, 29 ... Switch, 33 ... Sealing jig 113 ... Overflow outflow Path 58 ... Electronic control unit, 80 ... Small diameter opening, 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 AA19 AD05 AE01 AE31                       AF01 AG11 EA07 EB05 EB06                       HC10 KA11

Claims (4)

[Claims] 1. A test container is filled with test water by setting the metal portion of a metal container coated with a non-conductive inner surface to one polarity and the conductive member disposed in the metal container to the opposite polarity. After that, by applying an arbitrary voltage between both electrodes, the current generated at the time of application is detected, and in the inner surface coating film inspection device of the metal container that inspects the inner surface coating film based on the detected current value, the inspection of the inner surface coating film of the metal container From a position below the water surface position of the test water filled so as to cover the target area, to a passage provided above the water surface position, and in the passage, the water surface position of the inspection water, and in the vertical direction. An inner surface coating film inspection device for a metal container, comprising: a water level detecting means provided at the same height position or at an upper position. 2. An opening formed at least at one end,
A conductive member inserted into the inside of the metal container from the opening of the metal container provided with a non-conductive inner surface coating applied to the inner peripheral surface, and the metal container and the conductive member are relatively moved. By doing so, the drive unit for inserting the conductive member into the metal container so as to be in a non-contact state with the metal container, and withdrawing the conductive member from the inside of the metal container to the outside. An electrode that contacts a portion where the inner surface coating of the metal container does not exist, the conductive member is inserted into the inside of the metal container, over the area facing the inner surface coating inside the metal container, the inspection water And a test water supply device for filling the inside of the metal container, over a region facing the inner surface coating and a region facing the conductive member, in a state of being filled with test water, inserted into the metal container. A voltage applying device that applies a voltage between the conductive member that is in contact with the metal container and the electrode that is in contact with the metal container, and a voltage is applied between the conductive member and the electrode when the voltage is applied by the voltage applying device. In a metal container inner surface coating inspection device comprising a current detector that detects the current of the current detector and a determination device that determines a defect of the inner surface coating from the current detected by the current detector, and supply to the inside of the metal container. A flow rate control valve for controlling the flow rate of the test water to be used, a flow rate sensor provided between the flow rate control valve and the test water supply path to detect the flow rate of the test water supplied to the metal container, and the conductive member In, a passage provided so as to communicate the inside and the outside of the metal container, a water level detection sensor provided at a predetermined position of the passage, for detecting the water level of the test water supplied to the inside of the metal container, The flow rate sensor The flow rate measured by the sensor is compared with a preset flow rate, and when the detected flow rate reaches a preset flow rate, a signal for stopping the supply of the test water is output and the water level detection sensor And an electronic control unit that determines whether or not a preset amount of test water has been supplied to the metal container from the detection state of 1. 3. The test container is filled with test water by setting the metal portion of the metal container having a non-conductive inner surface coating to one polarity and the conductive member arranged in the metal container to the opposite polarity. After that, an arbitrary voltage is applied between both electrodes, a current generated when the voltage is applied is detected, the inner surface coating film is inspected based on the detected current value, and the inspection is performed while transferring the metal container through a predetermined path. In the inner surface coating inspection method of a container, when the metal container is transferred through the path, whether the water surface of the filled inspection water is maintained in a predetermined horizontal state is different depending on the entire circumference in the metal container. A method for inspecting an inner surface coating of a metal container, which is characterized by monitoring from the direction and, when an abnormal water level is detected, determining that the inner surface coating has not been inspected. 4. The test container is filled with test water by setting the metal part of the metal container having the non-conductive inner surface coating to one polarity and the conductive member arranged in the metal container to the opposite polarity. After that, an arbitrary voltage is applied between both electrodes, the current generated when the voltage is applied is detected, the inner coating is inspected based on the detected current value, and the inspection transfers the metal container through a path on the circumference of a predetermined radius. In the inner surface coating film inspection method of a metal container performed while, when the metal container is transferred through the path, a centrifugal force acting on the metal container and an action line passing through the center of the metal container,
Of the points where the line along the inner circumference of the metal container intersects, a point near the center of the circumference of the transfer path or its vicinity, or
Detecting the water level of the test water at a location far from the center of the circumference of the transfer route or in the vicinity thereof, or both, and when an abnormal water level is detected, it is determined that the inner surface film is not tested. A method for inspecting an inner coating of a metal container, which is characterized.