JPH0432983B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Technical Field of the Invention) The present invention relates to an apparatus for inspecting the quality of the inner surface protective coating of an inner surface coated can.

(Prior art and its problems) Normally, the inner surface of a metal can is protected from corrosion caused by the attack of the contents of the can, and from deterioration of quality due to the can material leaching into the can contents. A protective coating is applied to prevent this.

However, the protective coating on the inner surface of a can may have eye holes, etc., depending on the condition of the inner surface of the can before painting and the adjustment condition of the coating equipment, and may also be affected by the adjustment condition of the conveying device, etc. after painting. Since scratches may occur, prevent the occurrence of such paint film defects,
In addition, in order to prevent cans with paint film defects from being shipped, cans are sampled at regular intervals to ensure that no cans with paint film defects have been produced. It is necessary to constantly check that mechanical equipment is maintained in good condition.

The QTV (Quick Test Value) measurement method is used to test the quality of the inner coating of cans.

In the QTV measurement method, an electrolytic solution such as saline or sodium sulfate solution is placed in a can, and one electrode (usually the positive electrode) of a current measuring device consisting of a DC power source, an ammeter, and two electrodes is connected to the can. Contact the exposed metal part (bottom or open end of the can) with the other electrode (usually the negative electrode)
In this method, the electrolyte is immersed in the electrolyte in the can, a voltage is applied between both electrodes, and the current flowing between the can and the electrode in the electrolyte is measured using an ammeter.

If there are no defects in the inner surface protective coating, the value on the ammeter remains zero, and if the defects in the coating are large and numerous, the value on the ammeter increases.

This inspection method is a destructive inspection, so it usually takes about 30 minutes.
Sample once every 2 hours (5-10 at a time)
Cans are inspected for paint film defects.

Traditionally, commercially available inspection devices have a built-in DC power supply and a digital display ammeter, and on one side of the device body, there is a top and bottom section that extends vertically from the top for a predetermined height and curves laterally from the middle. An electrode for dipping into the electrolyte (hereinafter referred to as the center electrode) is suspended from the tip of the movable L-shaped arm, and from near the bottom end on the same side, An arm part, to which a dish-shaped can mounting electrode (hereinafter, an electrode that contacts the exposed metal part of the can is referred to as a contact electrode) is fixed to the tip thereof, extends laterally.

How to use this testing device (or measuring device) is to first fill a sample can with electrolyte, then place the can on the contact electrode, and then push down the vertically movable arm by hand. When the center electrode suspended from the lateral extension of the arm is immersed in the electrolyte in the can (the arm is designed to descend only a predetermined distance), the arm When the descent is complete, the current circuit is turned on, and the value of the current flowing between the can and the center electrode is displayed digitally.

This inspection device cannot inspect if the outer surface of the bottom of the can (grounded part) or the outer surface of the can lid that is fixed to the can body at the can manufacturing factory is coated, and the inspector may
It is unclear whether measurements were taken after filling the electrolyte close to the open end where coating film defects are most likely to occur (i.e., for cans filled with electrolyte close to the open end of the can,
Since liquid spills are likely to occur, inspectors tend to psychologically reduce the amount of electrolyte put into the can.On the other hand, since coating film defects tend to occur near the open end, do not pour the electrolyte all the way to the open end. Otherwise, even if the display indicates that no current flows, it cannot be said that there are no paint film defects, so the measurement results will be unreliable and the test will be insufficient. ) However, there is a drawback that only cans of approximately the same height can be inspected because the amount of descent of the vertically movable arm is constant.

Of these drawbacks, an inspection device that eliminates the first two drawbacks is disclosed in Japanese Utility Model Application Publication No. 55-36400.
to ensure that the is placed in place.
Base 10 having a recess 104 for receiving a can C
3, a spring contact 105 that firmly contacts the open end 102 of the can and acts as a contact electrode when the can C is placed in the recess 104 of the base 103, and an L-shaped arm 106 that is movable up and down. A center electrode 108 is suspended from the lateral extension 107 of the L-shaped arm 106, and a detection electrode 109 is used to detect that the electrolyte has entered a predetermined position near the open end of the can. In addition, although not shown, an enabling circuit that emits a signal to indicate that measurement preparation is complete when the electrolyte reaches a predetermined position near the open end of the can, a DC power source, and Since it is equipped with an instrument panel, it is possible to inspect even cans whose bottom outer surface is painted, and there is no need to measure cans that do not contain electrolyte near the open end. Paint film defects near the opening end will not be overlooked.

However, this inspection device
L-shaped arm 1 that is lowered after injecting electrolyte into
06 is still constant (therefore, the center electrode 1
08 and the amount of descent of the detection electrode 109 are also constant. ), there is a drawback that cans of different heights cannot be inspected, and furthermore, sample cans C
When the bottom of the sample can C is accommodated in the recess 104 of the base 103, the spring contactor 105 just contacts the open end (flange tip) 102 of the sample can C. It also has the disadvantage that it cannot be tested.

Nowadays, when many types of cans are on the market (cans that differ in at least one of the height and opening end diameter are treated as different types), many cans can be made at the same time in one can factory. As more and more types of cans are manufactured, inspection equipment that can only inspect one type of can is
Inspection equipment is required for the number of types of cans manufactured in the industry, and the cost of inspection equipment increases considerably.Furthermore, space is required for many inspection equipment, so the number of cans increases. This results in increased costs, and since different types of cans are often manufactured on the same production line, inspectors are confused as to which equipment to use.

Among the beverage cans (2-piece cans and 3-piece cans) for which it is especially necessary to inspect the quality of the inner protective coating film by QTV measurement, the body diameter (outer diameter) of the cans that are commonly available today is approximately 53 mm. (so-called 202 diameter) ~ 83.8mm (so-called
307 mm), and the height is approximately 79 to 204.5 mm.

Note that if the diameter of the body changes, the diameter of the opening end will also change.

If two or more types of cans among these many types of cans can be inspected using one inspection device, these drawbacks will be reduced or eliminated.

(Means for Solving the Problems) The present invention eliminates or reduces the defects of the inspection device as disclosed in the above-mentioned Japanese Utility Model Publication No. 55-36400, and inspects (QTV measurement) the quality of the inner surface protective coating of the inner surface coated can. It is an object of the present invention to provide an apparatus for inspecting the quality of an inner protective coating film that can inspect cans having different heights and diameters of the opening end (flange tip).

That is, a DC power source, a center electrode connected to one terminal of the DC power source and immersed in an electrolyte in a sample can having a protective coating on the inner surface, and connected to the other terminal of the DC power source; An electrochemical cell is constituted by a contact electrode in contact with the exposed metal portion of the open end of the sample can, and an ammeter disposed between the DC power source and the center electrode or one of the contact electrodes. , an inspection device of the type that detects a current flowing between the center electrode and a sample can having an inner surface protective coating to detect defects in the inner surface protective coating of the sample can, on which the sample can is placed. a base; a vertically movable arm having a lateral extension extending above the base; a center electrode and an electrolyte surface suspended from the lateral extension; and a motor for moving the arm downward, and an opening of a sample can suspended from the lateral extension and placed on the base. It has a can detector that detects the end, and a control device that stops the downward movement of the arm in response to a signal from the can detector, and the contact electrode is in a state where it can move up and down and cannot fall off. It is composed of a rod-shaped portion attached to the horizontally extending portion, and a contactor fixed to the lower end of the rod-shaped portion and in contact with the open end of the sample can, and furthermore, the contactor is connected to the base. It slopes downward from the axis of the sample can on the table toward the outside, and its horizontal length corresponds to the highest and lowest open end diameters of the sample can to be inspected. , and furthermore, at least the portion of the contact that contacts the open end of the sample can to be inspected is at the height of the detection part of the can detector before the arm moves downward. A quality inspection device for the inner surface protective coating of an inner-coated can (hereinafter referred to as
a DC power source; a center electrode connected to one terminal of the DC power source and immersed in an electrolyte in a sample can having a protective coating on the inner surface; A contact electrode connected to the terminal and in contact with the exposed metal part of the open end of the sample can, and an ammeter disposed between the DC power supply and the center electrode or one of the contact electrodes, This is a type of inspection device that detects a current flowing between the center electrode and a sample can having an inner surface protective coating to detect defects in the inner surface protective coating of the sample can. a base on which a can is placed; an arm that can move up and down and has a lateral extension extending above the base; and a center suspended from the lateral extension. The device is equipped with an electrode and an electrolyte level detector, and includes a motor that moves the arm downwardly, and a motor that is suspended from the horizontally extending portion and is placed on the base. a can detector that detects the open end of the sample can that is in the sample can; and a control device that stops the downward movement of the arm in response to a signal from the can detector; It has a shape in which the center part is bent by a folding line in the vertical direction, and the ridge line formed by the folding line is placed outward at a distance sufficiently wider than the diameter of the sample can to be inspected. two or more contacts having a vertical length greater than the difference between the highest and lowest heights of the sample cans to be tested, each contact horizontally and A quality inspection device for the inner surface protective coating of an inner-coated can, characterized in that it can move toward the can at the same speed as other contacts.

(Function) In the inspection device of the first invention, the downward movement (descending) of the arm means that the can detector suspended from the lateral extension of the arm detects the open end of the sample can on the base. Since it stops when it is detected, even if the height of the sample can changes (varies), the distance between the lateral extension of the arm and the open end of the sample can is always constant; The distance between the tip of the liquid level detector suspended from the extension and the open end of the sample can is always constant, so the inspector injects electrolyte into the sample can (by turning on the liquid supply pump). When injecting (using or manually injecting), simply continue injecting until the liquid level detector detects it (injection can be stopped automatically by a detection signal or by stopping work by visually checking the detection signal). No matter the height of the sample can, electrolyte can always be reliably injected to a certain distance from the open end, improving the reliability of test results for sample cans of different heights. The contact, which is attached to the lateral extension of the arm so as to be movable up and down, is inclined so as to descend outward from the axis of the sample can, and furthermore, the horizontal component of the contact is The length is greater than 1/2 of the difference between the highest and lowest open end diameters of the sample can to be tested, and at least the part of the contact that comes into contact with the open end of the sample can to be tested. However, before the arm moves downward, it is at a position below the height of the detection part of the can detector, so the contact that descends with the downward movement of the arm is within the height of the opening end diameter. It is possible to reliably contact not only two or more types of sample cans with one side different, but also the open ends of two or more sample cans with both different types, and since the contactor is slanted as described above, the electrolyte can be opened. Since the contacts do not come into contact with the raised electrolyte surface that occurs when the electrolyte is injected to a height very close to the end (in other words, there is no short circuit), it is possible to For any of two or more types of sample cans, the quality of the inner protective coating can be inspected without overlooking coating defects near the open end where coating defects are most likely to occur.

Also in the inspection device of the second invention, the downward movement of the arm stops when the can detector suspended from the lateral extension of the arm detects the open end of the sample can on the base. Even if the height of the sample can changes, the distance between the tip of the liquid level detector suspended from the lateral extension and the open end of the sample can is always constant. Even if it is a can, the electrolyte can always be reliably injected to a certain distance from the open end, improving the reliability of test results for sample cans of different heights. It has a shape in which the center part is bent by a folding line in the vertical direction, and the ridge line formed by the folding line is placed outward at a distance sufficiently wider than the diameter of the sample can to be inspected. 2
Each contact has one or more contacts, each of which faces horizontally and toward the sample can, is movable at the same speed as the other contacts, and has the highest height of the sample can to be tested. Since the vertical length is larger than the difference between the sample cans and the lowest sample cans, the contact can reliably contact any of the open ends of two or more types of sample cans with different open end diameters and heights. Moreover, since the contact approaches and contacts the open end of the sample can from the side, it does not come into contact with the raised electrolyte surface that would occur if the electrolyte was injected to a height near the open end ( (In other words, there will be no short circuit.) Therefore, for any of two or more types of sample cans with different opening end diameters and heights, the inner surface can be inspected without overlooking coating film defects near the opening end where coating film defects are most likely to occur. The quality of the protective coating can be inspected.

Example 1 An example of the first invention will be described with reference to the drawings.

FIG. 1 is a partially cutaway front view showing essential parts of a first embodiment of the device of the present invention, and FIG. 2 is a side view of the device shown in FIG. 1 taken along line A-A in FIG. ,
FIG. 3 is a plan view of the first illustrated device with the cover removed.

Reference numeral 1 denotes an arm part which can be moved up and down by the driving force of a motor (not shown), and is hollow, into which an electrolyte supply pipe 4 is installed and conductors to various devices to be described later are wired. It is fixed to the vertically extending portion 2 by a nut 8, and the vertically extending portion 2 is fixed to the vertically extending portion 2.
Laterally extending portion 3 extending horizontally to
It consists of

The horizontally extending portion 3 has a metal plate-like portion 9 (second
) and a disc-shaped part 1 made of nylon resin that is fixed to this plate-shaped part 9 with two bolts 10, 10.
It consists of 1.

Reference numeral 12 designates an electrolyte injection pipe which is threadedly engaged with the disc-shaped part 11 constituting the lateral extension part 3 of the arm part 1 and is suspended from the disc-shaped part 11, and is hollow as a whole. It is connected to the supply pipe 4 by an elbow 13 at the upper part.

The amount of electrolyte injected into the sample can can be reduced by making the lower part of the liquid injection tube 12 into a large diameter part 23, but this outer diameter is larger than the inner diameter of the smallest diameter sample can to be tested. Of course it's small.

Reference numeral 14 designates a copper center electrode attached around the large diameter portion 23 of the liquid injection tube 12, and is connected to a DC power source (not shown) via a conductive wire 15.

Reference numerals 16 and 16' indicate conductors 17 and 17' for the electrolytic solution level injected into the sample can.
The reason why two short pieces are provided is that the liquid level detector 16' is the longer one, that is, the one whose tip is positioned downward (for example, the tip is positioned 5 to 6 mm below the open end of the sample can) to measure the liquid level. After detecting this, the amount of electrolyte to be supplied (supply speed) is determined by means such as closing one of two solenoid valves (not shown) provided in the supply pipe 4 based on a signal sent through the conductor 17'. This is to reduce the electrolyte supply so that the supply of electrolyte can be stopped almost exactly at the position detected by the liquid level detector 16 whose tip is located upward (from the time the detection signal is sent until the valve is closed). Since the supplied amount of electrolyte is small, the electrolyte will not overflow from the sample can even if the tip of the liquid level detector 16 is almost aligned with the open end of the sample can. Since the liquid can be injected, the reliability of the inspection is increased.) In place of the two solenoid valves, the opening amount of the valve is reduced by a signal from the liquid level detector 16' whose detection part is located at the bottom. A method of reducing the supply amount (supply speed) may be adopted, and if it is acceptable that the electrolyte injection time is somewhat longer, it is of course sufficient to use only one liquid level detector 16.

Reference numerals 18 and 18' indicate metal L-shaped holders 19 and 1 that are fixed to the disc-shaped portion 11 constituting the lateral extension portion 3 of the arm portion 1 with bolts and are suspended.
The can detector 18, 18' is a can detector attached to the motor. As the arm part 1 moves downward due to the drive, it descends to a base (not shown).
When the open end of the sample can placed above is detected, a can detection signal is output. The signal is emitted from the receiver when it is blocked by the open end of the sample can and cannot reach the receiver.)

This can detection signal is sent to a control unit (not shown) through a cable 22, and the control unit that receives this signal performs either a clutch operation, a motor drive stop operation, or both operations. Lowering the arm 1 by an appropriate means such as
stop.

5 is a rod-shaped portion 24 that is vertically movably inserted into a vertical through-hole provided in the disc-shaped portion 11;
A contact electrode 25 is fixed to the lower end of the rod-shaped part 24 and is for contacting the open end of the sample can, and is a contact electrode for supplying current to the sample can from the exposed metal part of the open end. 6 is a contact electrode. It consists of a rod-like part 24' and a contact 25' similar to 5, 5, and it is confirmed whether the contact 25 of at least one of the two contact electrodes 5 is in contact with the open end of the sample can. This is a check electrode for

Rod-shaped portion 2 of contact electrodes 5, 5 and check electrode 6
4, 24, 24' are inserted into the through holes of the plate-shaped body 26, which has a donut shape or a substantially horseshoe shape (see FIG. 3) in which the upwardly projecting portion of the disc-shaped portion 11 is partially cut out. Bolts are tightened from the top and bottom of the body 26 to prevent it from falling out from the disc-shaped part 11, and springs 27, 27, 27' are attached to the lower part of the disc-shaped part 11. , the constant rod-shaped portions 24, 24, 24' (therefore,
Continue to apply downward pressing force to the contacts 25, 25, 25').

Note that the through hole of the disc-shaped portion 11 is connected to the rod-shaped portions 24 and 2.
4 and 24' can move up and down, so they may be slightly inclined.

Alternatively, a vertically elongated hole may be made in the rod-shaped parts 24, 24, 24' so that a part of the disc-shaped part 11 can be inserted into this hole (for example, a part of the disc-shaped part 11 may be inserted in a circle at intervals smaller than the width of the hole). Cut the plate from the edge toward the center to form the insertion rod.)

Contactor 2 of contact electrodes 5, 5 and check electrode 6
5, 25, and 25' are inclined so as to descend outward from the axis of the sample can when the sample can is placed at a predetermined position (inspection position) on the base. , and is curved in a direction perpendicular to this direction of inclination.

The reason why these contacts 25, 25, and 25' are inclined is to prevent contact with the liquid surface that rises due to surface tension when the electrolyte is injected to a height close to the open end of the sample can. Also, the reason why these contacts 25, 25, 25' are curved is that if they come into contact with the open end of each contact sample can at one point, the pressing force of the springs 27, 27, 27' and the plate-shaped body 26 will be reduced. The opening end portion (flange portion) is
This is to avoid damage to the opening end by distributing the pressing force from each contact so that each contact can come into contact with the opening end at two locations.

From the upper ends of the rod-shaped parts 24, 24 of the contact electrode 5,
Conductive wires 7, 7 extend through the vertically extending portion 2 of the arm portion 1 and are connected to a DC power source (not shown), and the conductive wires 7, 7 are further branched in the middle. , each contactor 2 is connected by a conductive wire 7' extending from the upper end of the rod-shaped portion 24' of the check electrode 6, a DC power source, a voltmeter, a resistor, and a sample can (not shown).
5 and 25' are configured as switches (contactors 25 and 25 of contact electrodes 5 and 5, sample can, contactor 25' of check electrode 6, power supply of the circuit consisting of DC power supply and each contactor). 25, 25'
A resistor is wired in parallel between the resistor and the terminals of a voltmeter are connected to both ends of the resistor to measure the voltage across the resistor. ), contact 25' of check electrode 6
and at least one of the two contacts 25, 25 of the contact electrodes 5, 5 are inspected when they are in contact with the open end of the sample can (the tip of the flange where the metal is exposed). (If the voltmeter scale reaches zero, it means that electricity has flowed between the check electrode 6, the sample can, and the contact electrode 5, and at least one of the contacts 25, 25 of the contact electrodes 5, 5 and the open end of the sample can are in contact.)
This prevents defects in the inner protective coating from being overlooked due to poor contact between the contact electrode and the open end of the sample can.

28 is a cover made of synthetic resin, which is fixed to the plate-shaped part 9 and the disc-shaped part 11 of the arm part 1, and is
2, the elbow 13, and the conductor wires of each device.

Furthermore, like the conventional device, the device of this embodiment is equipped with an ammeter (not shown) between the DC power source and the contact electrodes 5, 5, and is mounted at a predetermined position on the base. The center electrode 14 is immersed in the electrolyte in the sample can, the electrolyte, the defective part of the inner protective coating of the sample can, the sample can, and the open end (exposed metal part) of the sample can. , the amount of electricity flowing through the circuit formed by the contact electrode in contact with the open end of the sample can, the ammeter and the conducting wire can be detected.

The base (not shown) of the apparatus of this embodiment is provided below the lateral extension 3 of the arm 1 in order to place the sample can to be tested. Therefore, a desk or the like placed in the place where the inspection equipment will be installed can be used instead.

Also, if a circle with each diameter of the sample can to be inspected is drawn on the base with the extension line of the central axis of the injection tube 12 as the center, the inspector can place the sample can at a predetermined position on the base (inspection position). ), this is convenient when using the method of placing it by hand.

In this embodiment, the vertically extending portion 2 and the plate-shaped portion 9 constituting the laterally extending portion 3 of the arm portion 1 are made of metal from the viewpoint of strength. The disk-shaped portion 11 constituting the extending portion 3, the plate-shaped body 26 having a partially cut-out donut shape or approximately horseshoe shape, the liquid injection tube 12, the elbow 13, and the cover 28 are insulating, Nylon resin is used from the viewpoints of strength, weight, workability, and electrolyte resistance, and the liquid level detectors 16, 16', contact electrode 5 are
and the rod-shaped parts 24, 24, 24' of the check electrode 6, the contacts 25, 25, 25' and the rod-shaped parts 24, 24,
The nut fixing 24' to the plate-like body 26 is made of a corrosion-resistant superalloy containing molybdenum and chromium as main components in view of electrolyte resistance and conductivity, and the rod-like parts 24, 24, Spring 2 attached to 24'
7, 27, 27' were made of stainless steel, and the L-shaped holders 19, 19' were made of metal. Furthermore, since a light projector and a light receiver were used for the detection parts 20 and 21 of the can detectors 18 and 18', the cable 22 was made of glass fiber.

Next, a method of operating the apparatus of this embodiment will be explained.

In addition, here, the height of the sample can is about 75 mm to about 160 mm, and the body diameter is about 53 mm (202 diameter) to 77.8 mm.
(301 diameter), the length from the lower surface of the disc-shaped part 11 to the large-diameter part 29 of the rod-shaped parts 24, 24, 24' of the contact electrodes 5, 5 and the check electrode 6 is 26 mm, Length l of 25, 25' (length in inclination direction)
32 mm, the horizontal length W and vertical length h of the contacts 25, 25, 25' are approximately 22.7 mm, respectively, and the rod-shaped portions 24, 24, 2 of each electrode from the center of the liquid injection tube 12
The horizontal distance to the center of 4' is 35 mm, and the upper end of the detection part 20 of the can detector 18 and each contactor 25, 2
An example of a device in which the upper ends of 5 and 25' are adjusted to be approximately the same height will be explained.

First, the sample can is placed at a predetermined position (inspection position) on the base.

Next, when the switch of the motor that moves the arm 1 downward is turned on to start the downward movement of the arm 1, the arm 1
can detectors 18, 18', center electrode 14, liquid level detector 16,
The contact electrodes 5, 5 and the check electrode 6, which are inserted into the vertical through hole of the lateral extending portion 3 in a manner that they cannot fall out, also start to descend together with the arm portion 1, and this descent is caused by the can. Detection section 2 of detector 18
The control section receives a signal from the detection section 21 that is emitted when the light from the light emitter 0 (emitter) is blocked by the open end of the sample can and no longer reaches the detection section 21 (receiver). The movement continues until it is stopped.

When the arm part 1 stops moving downward, the contact electrodes 5, 5
and the contacts 25, 25, 25' of the check electrode 6 are
It is in contact with the open end of the sample can, and the large diameter part 2
The center electrode 14 and the tip of the liquid level detector 16' attached around the sample can are inserted into the sample can, and the tip of the liquid level detector 16 is approximately parallel to the open end of the sample can. They are at the same height.

The liquid injection pipe 12, the liquid level detectors 16, 16', and the can detectors 18, 18' are suspended from (i.e., fixed to) the laterally extending portion 3 of the arm 1.
Therefore, even if the height of the sample can changes, the distance between the open end of the sample can and the tips of the can detectors 18, 18' and the liquid level detectors 16, 16' when the arm 1 stops moving downward is The distance is always almost constant.

Moreover, even if the height of the sample can is different, if the diameter of the opening end (flange tip) is the same, the contactors 25, 25,
25' contacts the open end of the sample can at the same location.

However, the contact electrodes 5, 5 and the check electrode 6 of this embodiment are inserted into the vertical through hole of the horizontally extending portion 3 in a state that they cannot fall out, and the contacts 25, 25, 25 of these electrodes ′ is inclined outward from the axis of the sample can placed at a predetermined position (inspection position) on the base, so if the diameter of the sample can is different,
The position of the contact that contacts the open end of the sample can is different, and the timing at which the contact and the open end come into contact is also different (the contact occurs between the start of the downward movement of the arm 1 and the stop of the downward movement). (If the height of the sample can is the same, the contactor and the open end will come into contact with each other more quickly as the diameter of the open end is larger.) These will be further explained in the following specific examples.

For example, we sampled a DI can (350ml can) with an outer diameter of approximately 66mm (211 diameter) and a height of approximately 122.2mm, and a DI can (250ml can) that also had a diameter of 211 and a height of approximately 92.7mm. In the case of a can, the contacts 25, 25, 25' of the contact electrodes 5, 5 and the check electrode 6 descend with the downward movement of the arm 1, and the contactors 25, 25, 25' of the contact electrodes 5, 5 and the check electrode 6 descend with the downward movement of the arm 1, and the contactors 25, 25, 25' of the contact electrodes 5, 5 and the check electrode 6 descend with the downward movement of the arm 1, and each contactor touches the opening of the sample can at approximately the center of the contactors. The contact state is maintained even while the arm 1 continues to move downward (during this period, the open end of the sample can contacts the contacts 25 and 2).
5, 25', arm 1.
An interval corresponding to the amount of descent is provided between the disc-shaped part 11 and the plate-shaped part 26. In other words, contact 2
Arm part 1 after 5, 25, 25' contacts the open end
The disc-shaped portion 11 and the contacts 25, 25,
25' becomes narrower. ).

Thereafter, the detection parts 20 (projectors) and 21 of the can detectors 18 and 18' which descend as the arm part 1 descends.
When the upper end (of the light receiver) and the open end of the sample can coincide, the downward movement of the arm 1 is stopped by the action of the control section.

At this time, for both the 350ml can and the 250ml can, the distance from the open end to the liquid level detectors 16, 16' and the center electrode 14 is the same, and the part of each contact that is in contact with the open end is almost the same. are the same.

The only difference between these two types of sample cans is that the time from the start of the downward movement of the arm 1 to the contact with the contact is shorter in the 350 ml can with a higher can height.

In addition, sample cans with body outer diameter of approximately 74.5 mm (301
A three-piece can (diameter) and a height of approximately 113.5 mm (420
ml can) and a three-piece can (250ml can) with a body outer diameter of approximately 53.0 mm (202 diameter) and a height of approximately 133.3 mm (both cans have no netzin treatment, or both cans have the same number of pieces) (Assume that it has been treated with netquin.)
The latter has a body diameter approximately 21.5 mm smaller than the former, but the can height is approximately 19.8 mm higher than the former (1/1 of the body diameter).
2), the open end comes into contact with each contact earlier than in the former case.

At this time, each contactor contacts the former open end at a part slightly outside the center (slightly below the center), and the latter contacts at a part near its inner end (upper end). (closest part).

In addition, in this specific example device, the horizontal length W of each contactor is smaller than the range of the body diameter of the sample can to be inspected.
The reason for this is that when placing the sample can on the base, it may shift considerably from the specified position, so in such cases, each contact must be connected to the open end of the sample can. This is because we allowed a considerable amount of leeway so that we could make contact.

If the sample can is placed accurately on the predetermined position on the base, the horizontal length W of the contact will be the diameter of the open end of the sample can to be inspected (the outer diameter of the flange tip).
The length should be slightly longer than 1/2 of the range (the largest diameter - the smallest diameter).

Therefore, the horizontal length W of each contact required to inspect sample cans of different types or more with different opening end diameters is 1/2 of the difference between 301 diameter and 211 diameter which are close
(approximately 4.3 mm), the 301-diameter can is subjected to one stage of neck-in processing, which has been commonly implemented in recent years to reduce the amount of can material used, and the opening end portion is reduced in radius by approximately 1.5 mm. Considering that the sample can is displaced by 1.0 mm from the predetermined position on the base, it is sufficient that it is approximately 3.8 mm or more.

In this case, the inner end (upper end) and outer end (lower end) of the contact electrode and the check electrode are the open end of the smallest diameter sample can placed at a predetermined position (inspection position) on the base, respectively. Contact electrodes and check electrodes must be attached to the laterally extending portion of the arm so that they are positioned inward from the tip of the flange and outward from the opening end of the largest diameter one (tip of the flange). Needless to say.

If the body diameter is almost the same (in particular, the diameter of the open end is almost the same), but only the height is different, if it is only used to test two or more types of sample cans, each contactor should be Horizontal length of 1mm or more
It is also good to be less than 3.8 mm (in addition, if the body diameter is the same, and the one without the neck-in process and the one with the two-stage net-in process, the horizontal length is 4.2 mm.
mm is fine. ).

To check whether at least one of the contacts 25, 25 of the contact electrodes 5, 5 is in contact with the open end (flange tip) of the sample can, turn on the power supply and voltmeter of the continuity check circuit described above. You can know by this.

That is, a zero reading on the voltmeter indicates that the contactor 25 of one or more contact electrodes 5 is in contact with the open end of the sample can.

Therefore, defects in the inner surface protective coating due to poor contact between the contact 25 of the contact electrode 5 and the open end (exposed metal part) of the sample can are overlooked (the contact 25 and the open end of the sample can are in contact with each other). Otherwise, even if there is a coating defect, the ammeter value will be zero.)
can be avoided.

It goes without saying that the switch of the continuity check circuit may be turned on before the arm 1 moves downward.

Now, after the downward movement of the arm 1 has stopped, the liquid supply pump (not shown) is activated (for example, the inspector operates a switch, or the computer issues a signal to stop the downward movement of the arm 1). (The start switch of the pump may be turned on when the sample is filled.) Then, injection of the electrolyte into the sample through the injection tube 12 is started.

When the level of the injected electrolyte rises and is detected by the level detector 16' inserted deeper into the sample can, the level detector 1
6' is two electromagnetic valves (not shown) attached to the liquid supply pipe that emit a detection signal and receive this signal.
One of them closes to reduce the amount of electrolyte supplied, which slows down the rate at which the level of electrolyte in the sample can rises.

Therefore, when the remaining liquid level detector 16 detects the liquid level and issues a signal, and the other electromagnetic valve is closed to stop the supply of electrolyte, the electrolyte will not overflow from the sample can. .

Also, at this time, the liquid level of the electrolyte rises due to surface tension and becomes slightly higher than the open end of the sample can, but the contacts 25, 25 of the contact electrode 5 and check electrode 6 that are in contact with the open end of the sample can. , 25' are inclined downward from the axis of the sample can toward the outside, so that they do not come into contact with the electrolyte.

Next, the DC power supply and ammeter are switched on to measure the amount of electricity flowing between the center electrode 14 and the sample can, thereby determining whether the inner surface protective coating of the sample can is good or bad.

After inspecting one sample can, the motor is driven by a switch operation to move (raise) the arm 1 to its original position, and then the sample can is removed from a predetermined position on the base.

By repeating the above operations, a large number of sample cans can be tested.

In this embodiment, the electrolyte was injected into the sample can using a pump, but if the injection speed can be slow, it is of course possible for the inspector to inject the electrolyte from a beaker or the like.

Further, the description of the materials of each part in this embodiment is merely an example, and it goes without saying that materials having performance equivalent to or better than these or similar to these may be substituted depending on the intended use.

Embodiment 2 Next, an embodiment of the second invention will be described with reference to FIG.

This embodiment is the same as the first embodiment except for the contact electrode portion (that is, from the device of the first embodiment shown in FIGS. 1 to 3, contact electrodes 5, 5, check electrode 6, and contactors of these electrodes 25, 25, 25', rod-shaped part 2
4, 24, 24', spring 27, 27, 2
7', conductor wires 7, 7, 7' and horseshoe-shaped plate body 26
and the nuts fixing the rod-shaped parts 24, 24, 24' and the plate-shaped body 26 are removed. ), so the explanation of other parts will be omitted.

In this embodiment, the contact electrodes 41, 41 have a dogleg-shaped cross section formed by folding lines in the vertical direction at approximately the center of the plate-shaped body, with the ridge line formed by the folding lines facing outward. Two contacts 42, 42 face each other with an interval sufficiently wider than the diameter of the sample can to be inspected, and the contacts are fixed to the ridgeline portions of the contacts 42, 42 to transfer force from a driving source (not shown) to the contacts. 4
2, 42, and horizontally move the two contacts 42, 42 at the same speed and toward and away from each other (both are made of conductive material). ).

The contact electrodes 41, 41 of this embodiment are connected to the can detector 1 before or after the arm 1 moves downward.
8 and 18' detect the sample can C, and after the downward movement of the arm 1 has stopped, horizontally move toward the sample can C from both sides of the sample can C at the same speed, The open end (flange tip) of the sample can C is held between the contacts 42, 42 (fourth
(see figure), and since each of the contacts 42, 42 comes into contact with the open end of the sample can C at two places, the open end portion will not be damaged.

Also, the vertical length h' of the contacts 42, 42 is set to be larger than the difference between the highest and lowest heights of the sample can C to be inspected. The contact electrode 41,
41, the contacts 42, 42 can reliably come into contact with the open end even if the sample cans C have different heights. It is clear that it is possible to test the quality of the product.

Furthermore, since the contacts 42, 42 have a dogleg shape in cross section, sample cans C with different opening end diameters can be used.
can reliably contact any open end of the
It is possible to inspect the quality of the inner surface protective coating of many types of sample cans C, from cans with large open end diameters (ie, body diameters) to small cans.

In addition, since the contacts 42 approach and contact the open end of the sample can C from the side, the electrolyte that swells up when the electrolyte is injected to a height very close to the open end. There is no contact (short circuit) with surfaces.

In addition, in FIG. 4, the respective contacts 42, 42
The two planar parts forming the flange are vertical faces, but they may be made to be slanted faces.In particular, the opening end part is necked in so that the diameter of the opening end (flange tip) is equal to that of the body. If the diameter is less than the diameter, in order to prevent the contacts 42, 42 from being obstructed by the body and unable to contact the open end, move them outward from the axis of the sample can C placed on the base 30. It is necessary to tilt it so that it descends towards the sky.

Further, one of the contact electrodes 41, 41 may be used as a check electrode, or three or more contact electrodes may be provided.

As described above, the quality inspection device for the internal protective coating of internally coated cans according to the present invention can inspect not only cans with different opening end diameters but also cans with different heights. Even factories that manufacture products only need to install a small amount of inspection equipment, which makes it possible to reduce inspection equipment costs and installation space.
It also has the advantage of being easy to inspect.

[Brief explanation of drawings]

FIG. 1 is a front view of the essential parts of the device according to the first embodiment of the present invention, and FIG. 2 is a line A-A in FIG.
3 is a plan view of the first embodiment with the cover removed; FIG. 4 is a perspective view showing the contact electrode portion of the second embodiment of the present invention; and FIG. 5 is a diagram of the conventional device. FIG. 1... Arm portion, 3... Laterally extending portion, 5, 41
... Contact electrode, 14 ... Center electrode, 18, 18'
... Can detector, 20, 21 ... Detection section, 24 ...
Rod-shaped portion, 25, 42... contact, 30... base.

Claims (1)

[Claims] 1. A DC power supply, a center electrode connected to one terminal of the DC power supply and immersed in an electrolyte in a sample can having a protective coating on the inner surface, and the other terminal of the DC power supply. A contact electrode connected to the terminal and in contact with the exposed metal part of the open end of the sample can, and an ammeter disposed between the DC power supply and the center electrode or one of the contact electrodes, constitutes a target battery,
This is a type of inspection device that detects a current flowing between the center electrode and a sample can having an inner surface protective coating to detect defects in the inner surface protective coating of the sample can, and includes a base on which the sample can is placed. a base, a vertically movable arm having a lateral extension extending above the base, a center electrode suspended from the lateral extension, and electrolyte level detection. a motor for moving the arm downward; and a motor suspended from the lateral extending part;
It has a can detector that detects the open end of the sample can placed on the base, and a control device that stops the downward movement of the arm in response to a signal from the can detector. a rod-shaped part on which a contact electrode is attached to the horizontally extending part in a state where it can move up and down and cannot fall off; a contactor which is fixed to the lower end of the rod-shaped part and comes into contact with the open end of the sample can; Moreover, the contactor is inclined downwardly from the axis of the sample can on the base, and its horizontal length is in line with the sample to be tested. The diameter of the open end of the can is greater than 1/2 of the difference between the highest and lowest open end diameters, and furthermore, at least the portion of the contact that contacts the open end of the sample can to be tested is A quality inspection device for an inner surface protective coating film of an inner surface coated can, characterized in that the device is located at a position below the height of the detection part of the can detector before being moved downward. 2. A DC power supply, a center electrode connected to one terminal of the DC power supply and immersed in an electrolyte in a sample can having a protective coating on the inner surface, and a center electrode connected to the other terminal of the DC power supply, An electrochemical cell is constituted by a contact electrode in contact with the exposed metal portion of the open end of the sample can, and an ammeter disposed between the DC power source and the center electrode or one of the contact electrodes,
This is a type of inspection device that detects a current flowing between the center electrode and a sample can having an inner surface protective coating to detect defects in the inner surface protective coating of the sample can, and includes a base on which the sample can is placed. a base, a vertically movable arm having a lateral extension extending above the base, a center electrode suspended from the lateral extension, and electrolyte level detection. a motor for moving the arm downward; and a motor suspended from the lateral extending part;
It has a can detector that detects the open end of the sample can placed on the base, and a control device that stops the downward movement of the arm in response to a signal from the can detector, The contact electrode has a shape in which the center part of the cheek of the plate-shaped body is bent by a folding line in an approximately vertical direction, and the diameter of the sample can is larger than the diameter of the sample can to be inspected with the ridge line formed by the folding line facing outward. 2 or more contacts spaced sufficiently widely apart and having a vertical length greater than the difference between the highest and lowest heights of the sample cans to be tested. An apparatus for inspecting the quality of an inner surface protective coating of an inner surface coated can, characterized in that each contact element is movable in the horizontal direction, facing the sample can, and at the same speed as the other contact elements.