JPH026703A - Inspecting device for flange part of metallic can drum - Google Patents

Abstract

PURPOSE:To simultaneously inspect a flange bend part and the roundness by providing a photoelectric converting element group provided annularly so that it can receive reflected light from a normal flange part and only reflected light from the flange bend part. CONSTITUTION:In an inspecting head 12 for a flange part 4 of a drum part 2 of a metallic can 1, about 90 pieces of optical fibers 13 which have been connected to a light emitter 14 for projecting, light beam to the flange part 4 are inserted through a head body 12a in the vertical direction. Also, about 10 pieces of optical fibers 16 for receiving, reflected light from the normal flange part 4 are inserted through the body 12a toward the upper part of the diagonal inside on the inside of the fibers 13, and connected to photoelectric converting elements 17. The element 17 does not receive reflected light from the part which has lacked roundness of the flange part 4. About 60 pieces of optical fibers 19 for receiving reflected light from a flange bend part are inserted through the body 12a toward the upper part of the diagonal outside on the outside of the fibers, and photoelectric converting elements 20. In such a way, the roundness of the flange part 4 and the flange bend part can be inspected.

Description

[Detailed description of the invention] (Industrial application field) The present invention relates to carbonated beverage cans, beer cans, and coffee cans.

In the Franz part of metal can bodies used for fruit juice cans, etc.
The present invention relates to an apparatus for optically inspecting obliquely downward or downwardly curved portions and roundness.

(Prior art) Cans such as carbonated beverage cans are usually metal cans (made of tin-plated steel, tin-free steel, etc.) that consist of a body and a bottom, and the bottom is double-sealed to the flange of the body. 1 formed by a can or drawing process or drawing-ironing process
It is manufactured by filling a metal can (such as a piston can) with contents and then sealing it by double-sealing a lid to the flange of the opening of the metal can. Note that a so-called easy open end with a gel tab is often used as the bottom, but in this specification, such an end is also referred to as the bottom if it is double-sealed to the body before filling.

Plants that manufacture these metal cans and canneries that perform filling and sealing are often located relatively far from each other, and metal cans are usually loaded onto large pallets and transported to the cannery by truck or freight car. Or transported by ferry etc. Vibrations during transportation, or contact with the guide of a depalletizer during loading and unloading from a pallet in a cannery, tend to cause bends in the flange or damage its roundness. Similar defects are likely to occur during transportation using conveyors or the like within a factory.

In FIGS. 1 and 2, 1 is a metal can, 2 is a body, 3 is a bottom portion wrapped around the body, and 4 is a flange. The flange portion 4 is usually on the left side in FIG. As shown in the section,
Although the Franz bend portion 5 extends diagonally upward and outward, the Franz bend portion 5 may extend downward (in the case of FIG. 2) or, although not shown,
It is curved diagonally downward.

FIG. 3 shows the metal can 1 having such a Franz bent portion 5 filled with contents 6 and then fully tightened with the lid 7, and the normal Franz portion 11 is in a normal double Although the seaming portion 8 is formed, the flange bent portion 5 becomes a defective seaming portion as shown in 9, and sealing performance cannot be ensured. Therefore, a problem arises in that the contents 6 deteriorate completely during storage.

47a shown by a solid line in FIG. 4 shows the outer circumferential line of the flange portion 4' whose roundness has been impaired, and 4a shown by a dotted chain line has maintained normal roundness. Flange part 4
This shows the outer circumferential line of . If the roundness of the flange part 4' is impaired, the curled part of the lid part will not be placed perfectly on the flange part 4' during seaming work, and therefore double seaming will be required. It may become impossible to do so, or even if it is possible, it will likely result in a defective seam portion, and the same problems as described above will likely occur. Maximum diameter D1 of normal outer circumference line 4'a
The above problem is likely to occur when the difference between the minimum diameter D2 and the minimum diameter D2 is about 3 mm or more.

FIG. 5 shows a flange portion 4 which has been subjected to a very large external force and has locally suffered severe crushing deformation in the height direction, resulting in loss of roundness. , such a flange 4 is not only impossible to double seam, but also
There is no product installation at all.

Note that the flange portions 4', 4// whose roundness is impaired may be formed with a flange bent portion 5 (for example, see FIG. 5) or may not be formed. Furthermore, even in the flange portions 4/4, 4'' whose roundness is impaired, there are often normal flange portions 11 partially present as shown by 11 in FIGS. 4 and 5.

Incidentally, due to trouble during transportation at a can manufacturing factory, the above-mentioned defect may occur in the flange portion of the body before the bottom portion is fully tightened.

(Problem to be solved by the invention) A Franz bend inspection device is disclosed in Japanese Patent Application Laid-Open No. 59-87303.
This method has been proposed in Japanese Patent Publication No. 63-10362. However, the conventional device is for detecting the presence or absence of a Franz bend when the Franz portion has roundness. Therefore, although there are no bent flange parts, the roundness of each flange part is uneven, and therefore it is not possible to detect and eliminate metal can bodies that may impair the sealing performance after double seaming of the lid part. There was a problem.

SUMMARY OF THE INVENTION An object of the present invention is to provide an inspection device for a flange portion of a metal can body, which can simultaneously inspect a Franz bend portion and roundness.

(Means for Solving the Problems) The inspection device for the flange portion of a metal can body of the present invention is capable of simultaneously projecting projection light from directly above along substantially the entire circumference of the normal flange portion of the metal can body. A light projection device including a large number of cold light sources arranged in an annular shape, and a first photoelectric conversion element arranged in an annular shape inside the light projection device so as to be able to receive reflected light from a normal Franz portion. a first light receiving device having a group of photoelectric conversion elements; and a second light receiving device having a second group of photoelectric conversion elements disposed in an annular manner outside the light projecting device so as to be able to receive only reflected light from the bent portion of the flange. It is equipped with

In this specification, a normal flange section means that the roundness is substantially maintained, there is no bent part of the flange, and the sealing performance is ensured after double seaming of the end members such as the bottom and the lid. Refers to the flange part with possible shapes.

Further, the normal flange portion 11 refers to a portion having the above shape.

(Function) The inspection device of the present invention is located inside a light projection device that is equipped with a large number of annularly arranged light sources that can simultaneously project light from directly above along substantially the entire circumference of a normal flange portion. The first light receiving device includes a first photoelectric conversion element group arranged in an annular manner so as to be able to receive all of the reflected light from the normal Franz portion. Since the photoelectric conversion element of the first light receiving device does not receive reflected light from the out-of-roundness portion of the flange portion, the roundness of the flange portion can be inspected by the first light receiving device.

Further, on the outside of the light projecting device, a second light receiving device having a second photoelectric conversion element group arranged in an annular manner so as to be able to receive only the reflected light from the flange bending portion is provided. Since the photoelectric conversion element of the second light receiving device receives the reflected light from the Franz bend, the entire Franz bend can be inspected by the second light receiving device.

(Example) This figure shows an inspection head for the flange 4 of the body 2 of No. 1. Reference numeral 13 denotes a projection optical fiber for projecting projection light onto the flange portion 4, which is circularly shaped so that the projection light can be simultaneously projected from directly above along substantially the entire circumference of the normal flange portion 4. A large number of annular head bodies 12a (
i7 It is inserted vertically. The head body 12a is made of aluminum.

It is preferable that the number of optical fibers 13 is as large as possible within the range that can be manufactured so as to prevent uneven illuminance from occurring on the normal flange portion 4. In the case of this embodiment, the optical fiber 13
(0.55 mm in diameter) are provided. The optical fiber 13 is made of a material with a high infrared attenuation rate, for example, an acrylic plastic fiber. The optical fiber relay 13 is connected to a light emitter 14 located apart from the head 12. The light emitter 14 is equipped with a light emitter such as a light emitting diode or an incandescent lamp, and a reflector (a gicroic mirror with low infrared reflectance), and during inspection work, light always enters the optical fiber 13 via the reflector. are doing.

As shown in FIG. 10, the projected light 50 is transmitted through the optical fiber 13.
In this specification, the exit end 13ai of the optical fiber 13
It is called a light source. With the above configuration, even if the light emitter 14 generates heat and becomes somewhat high temperature, the optical fiber 1
The exit end of No. 3, that is, the light source 13a, is at the ambient environment temperature, that is, room temperature (approximately 40° C. or less). Therefore, the light source 13a is a cold light source. The diameter of the locus circle at the center of each light source 13a, that is, the diameter of the locus cylindrical surface 15a of the optical axis 15 of each light source 13a is approximately equal to or slightly larger than the outer diameter of the body 2 (approximately 1 to 2 It is preferable that the range is large).

Reference numeral 16 denotes inner receiving optical fibers (diameter 0.55 mm) whose lower ends 16a are arranged in an annular manner and at equal intervals inside the optical fiber 13 so as to be able to receive the reflected light from the normal flange portion 4. . The optical fiber 16 is inserted through the head main body 12ai so that its optical axis 18 is along the radial plane 22 of the locus cylindrical surface 15a and toward the inner side upward, and its upper end is connected to a photoelectric conversion element 17 (for example, a phototransducer ). The optical axis 18 of the optical fiber 16 is the locus cylinder i 15 a of the optical axis 15 of the optical fiber 13.
The preferred angle θ is the radius of curvature on the inner surface of the curved portion 4X of the normal flange portion 4, the distance between the flange portion 4 and the light source 13EL, and the angle θ on the curved portion 4X of the intersection line between the locus cylindrical surface 15a and the upper surface of the flange portion 4. (In other words, the angle between the normal line at the corresponding point P on the circumferential line 15b and the optical axis 18 is 1/2°θ), but usually 25 ~50 degrees, more preferably 30-4
It is 0 degrees. In this example, θ is 35 degrees. The number of optical fibers 16 is preferably 10 to 2 in the case of a No. 202 can.
There are 0 pieces. In this embodiment, the number is 10.

Reference numeral 19 denotes an outer light-receiving optical fiber (diameter 0.55 mm), which is arranged outside the optical fiber 13 so that its lower end 19a is annular and equally spaced so as to be able to receive only the light reflected from the flange bent portion 5. . The optical fiber 19 has a head body 12 a 1,1, and its optical axis 21 is the trajectory cylindrical surface 1.
It is inserted along the extension part 23 of the radial plane of 5a and diagonally outward and upward, and its upper end is connected to the photoelectric conversion element 2.
0 (for example, a phototransistor).

The angle δ between the optical axis 21 of the optical fiber 19 and the trajectory cylindrical surface 15a of the optical axis 15 is preferably set to 50 to 70 degrees. In this embodiment, the angle is 60 degrees. optical fiber 19
The number of flange portions 4 must be at least 1, and the field of view seen from the adjacent lower ends 19a (the viewing angle is usually about 60 degrees) must be directly above the normal flange portion 4. In this embodiment, there are 60 optical fibers 19.

Further, the optical fibers 16 and 19 are arranged such that their respective optical axes 18 and 21 intersect with the circumferential line 15b at a predetermined height h below the lower surface of the bend 12 of the locus cylindrical surface 15a.

In the case of this embodiment, the standard trowel of height h is 8++1+++.

The metal can 1 has its central axis aligned with the central axis 1 of the locus cylindrical surface 15a.
5c, and the flange portion 4 is substantially aligned with the head 12.
The inspection is performed in a state where the optical fiber 16 is placed at a position approximately a height h below the lower surface of the optical fiber 16 so as to be able to receive the reflected light 51 from the normal flange portion 4.

The inspection device 24 includes an inspection box 259 housing the inspection head 12, a light emitter 14. Metal cans 1 are spaced at predetermined intervals (for example, about 1
0 am) Place the metal can 1 at a distance (with magnetic adsorption), and continuously move the center axis of the metal can 1 in the direction of the arrow to the center axis of the inspection head 12 (the center axis 15c of the trajectory cylindrical surface 15a).
(transfer speed is, for example, 1200 cans per minute) through a magnetic belt conveyor 26. A light emitter 2 for detecting when the metal can 1 passes below the inspection head 12
7a and a photoelectric sensor 27 including a light receiver 27bi. A determination circuit 28 for determining whether the flange portion 4 is good or bad based on the signal from the inspection head 12. A paste ejector 29 is also provided for discharging metal cans 1 determined to be defective by the determination circuit 28 to the side of the belt conveyor 26.

25a in the inspection box 25 is the photoelectric conversion element 17
．． 20 and a housing section for a preamplifier 31, 41, and a photoelectric conversion element 27b, which will be described later, connected to a light receiver 27b;
This is the storage section located above 2.

The photoelectric sensor 27 detects when the center axis of the metal can 1 reaches a point about one point upstream from the center axis of the inspection head 12.
It is arranged so that the optical path 27c is blocked.

FIG. 9 shows a block diagram including the discrimination circuit 28, which includes a roundness discrimination circuit 28a and a flange curved portion discrimination circuit 28b. 17a on the roundness discrimination circuit 28a side.

17b is a photoelectric conversion element (for example, a phototransistor) connected to each inner light-receiving optical fiber 16, and although not shown, in this embodiment, 17a.

In addition to 17b, 8 pieces are provided, for a total of 10 pieces. 31a.

31b is a preamplifier, and 32a and 32b are comparison circuits. 33 is a reference value setting circuit, which includes a preamplifier 31a (
or 31b), the comparison circuit 32a (or 32b) outputs an NG signal (defective signal) to the corresponding storage circuit 34a (or 34b). Although exact illustration has been omitted, the memory circuit group 34 in this embodiment is composed of 1(l) memory circuits 34at34b, . . . .

27b1 is the light receiver 27 of the photoelectric sensor 27 as described above.
38 is a timing circuit, which has a built-in delay circuit with a delay time of 0.5 to 2.0 m5ec. That is, when the central axis of the metal can 1 passes a point approximately 1 mm before the central axis of the inspection head 12, the projected light from the projector 27a is blocked, and the photoelectric conversion element 27bl outputs an OFF signal, the timing circuit 38 outputs a storage command to the storage circuit group 34 via the delay circuit at the time when the central axis of the metal can 1 and the central axis of the inspection head 12 coincide in the transport direction.

Adjustment to obtain accurate timing when the two central axes coincide is performed by finely adjusting the delay time of the delay circuit using &lJ, -mm (not shown).

The memory circuit group 34 and each photoelectric conversion element 17a.

17b, . . . (If an NG signal is input, it is stored in the corresponding storage circuits 34a, 34b, . . . Add the number n of NG signals.

Reference numeral 36 is a defect judgment circuit, and 37 is a one-direction setting circuit for good and defect judgment criteria. In other words, the defect judgment standard is n. (for example, n.=2), the number n of NG signals is n
If it is larger, the signal is output from the determination circuit 36 as OR dirt 3.
9 is output.

On the flange bent portion determination circuit 28b side, 20a,
Reference numeral 20b denotes a photoelectric conversion element connected to each outer light-receiving optical fiber 19, which is also omitted from illustration in this case, but in the case of this embodiment, in addition to 20a, t, and 20b, 58 elements, 60 in total, are provided. 41a.

41b is a preamplifier, 42a and 42b are comparison circuits, 43
44 is a reference page setting circuit, and 44 is a memory circuit group (44a).

(composed of 60 memory circuits such as 44b, etc.), 45 is an adder circuit, 46 is a switch, a defect determination circuit, and 47 is a switch.

Each of the defect determination criterion 1 setting circuits functions similarly to the corresponding circuit of the roundness determination circuit 28a. However, the comparator circuit 42a (or 42b) outputs the output from the preamplifier 41a (or 42b) to the reference page setting circuit 4.
3, the comparator circuit 42
An NG signal is output to a (or 42b).

Reference numeral 48 denotes a rejector drive circuit, which has a built-in delay circuit, and when a signal is input to the OR gate 39 from either or both of the defect determination circuits 36 and 46, the metal can 1 is driven to the rejector 29. When the metal can 1 reaches the front of the belt conveyor 26, the rejector 29 is driven to remove the metal can 1 from the belt conveyor 26. 49 is a counter for counting the number of rejected metal cans, and 40 is a counter for counting the number of metal cans 1 that have passed under the inspection head 12.

The flange portion is inspected using the above-mentioned device as follows. Prior to inspection, the inspection head 12 and metal can 1
After finely adjusting the height h by moving the inspection head 12 up and down so that the reflected light from the normal Franz part 4 correctly enters the optical fiber 16 when the central axes of the
Start the inspection.

When the metal can 1 is transferred by the belt conveyor 26, at the moment when its central axis passes through a position substantially coinciding with the central axis of the gutter 12 to be inspected, the reflected light that has passed through the ten inner receiving optical fibers 16 is The reflected light that has passed through the corresponding photoelectric conversion elements 17 and the 60 outer light-receiving optical fibers 19 is received by each corresponding photoelectric conversion element 20 and directly converted into a voltage.

As shown in FIG. 10(a), the projected light 50 from the light source 13a is projected while forming a cone-shaped light beam with a projection angle α of approximately 60 degrees, and is projected between the light source 13a and the point P, that is, the flange portion 4.
When the height between the upper surfaces of the two is approximately 8 mm, the diameter d of the light beam leaking from the point P is approximately 10 mm. Since the normal width W of the flange portion 4 is usually about 3 mm, the roundness of the flange portion 4 may be considerably lost, or a considerably thick bent portion 5 may be formed in the flange portion 4. Even in this case, the projected light 50 does not fail to hit the flange portion 4.

As shown in FIG. 10(a), the normal flange portion 11
The reflected light 51 from the corresponding inner receiving optical fiber 1
A relatively large amount of light enters the 6x lens.

However, the reflected light based on any of the projected lights 50 does not enter the corresponding outer receiving optical fiber 19x.

Therefore, in this case, the corresponding memory circuits 32x and 42
No NG signal is input to any of x.

As shown in FIG. 10(b), although the roundness is impaired, the reflected light 51 based on the projected light 50 hitting the portion 11' which has a normal shape of the flange portion is reflected by the corresponding inner light-receiving optical fiber. 16x and outer receiving optical fiber 19x
No light enters any of them, or even if it does, the amount of light is very small. In this case, N
G signal is input.

As shown in FIG. 10(c), the reflected light 51 based on the projected light 50 hitting the flange bend 5 with its roundness intact is compared to both the inner receiving optical fiber 16x and the outer receiving optical fiber 19x. A large amount of light enters the target. In this case, the corresponding memory circuit 42xKNG signal is input.

As shown in FIG. 10(d), reflected light 51 is based on the projected light 50 that hits the Franz bent portion 5 whose roundness is impaired.
The light does not enter the inner light-receiving optical fiber 16x, or even if it does, the light intensity is very small. However, a relatively large amount of light enters the outer receiving optical fiber 19x.

In this case, the NG signal is input to both the corresponding storage circuits 32x and 42x.

As described above, for each metal can 1, the number of NG signals input to the 10 memory circuits 34a+34bl... and the 60 memory circuits 44a e 44b y... 35 and 45, and in the case of this embodiment, if either addition exceeds 2, and if both addition [original] exceeds 2, the rejector drive circuit 48 sends the reject signal to the rejector. -29, and the metal can 1 is discharged. Furthermore, the defective rate is calculated from the ratio of the count of the counter 49 and the count of the counter 40.

The present invention is not limited to the above embodiments,
For example, it is also applied to the body part 2 before the bottom part 3 is tightened. Further, the cold light source may be one based on V-the light which is scanned in an annular shape by a rotating reflecting mirror. The inspection may be carried out with the metal can body stopped. The relationship between the defect in the flange portion, the projected light, and the reflected light is not limited by the example shown in FIG.

The metal can 1 may be made of aluminum.

In this case, it is preferable to use an appropriate suction belt such as a vacuum suction belt instead of the magnetic belt 26.

(Effects of the Invention) The inspection device for the flange portion of a metal can body of the present invention can simultaneously inspect the bent portion of the flange and roundness. Alternatively, the double-sealed portion between the bottom parts has an effect of excellent sealing performance.

Furthermore, since the light source of the light projector is a cold light source, there is no risk that the temperature of the photoelectric conversion element of the light receiver will increase due to heat from the light source and its characteristics will change, resulting in high inspection accuracy. has.

[Brief explanation of the drawing]

FIG. 1 is a perspective view of an example of a metal can with a bent flange;
Figure 2 is a vertical sectional view taken along line II-II in Figure 1, and Figure 3 is a longitudinal sectional view of the main part showing the metal can in Figure 1 with the lid tightened after filling the contents. , FIG. 4 is a plan view of a first example of a flange portion with impaired roundness, and FIG. 5 is a front view of the main part of a metal can body having a second example of a flange portion with impaired roundness. 6 is a longitudinal sectional view of an inspection head of an inspection apparatus according to an embodiment of the present invention, FIG. 7 is a bottom view of the inspection head of FIG. 6, and FIG. 8 is a book having the inspection head of FIG. 6. An explanatory perspective view of an inspection device according to an embodiment of the invention, FIG. 9 is a block diagram showing a discrimination circuit of the device of FIG. 8, and FIG. 10(a)
b), (c), and (d) respectively show the first relationship between the projected light and the reflected light from the Franz portion when inspecting with the inspection head shown in FIG. Second. It is an explanatory drawing showing a 3rd and a 4th example. 2... Body part (metal can body), 4... Flange part, 5...
... Flange bent portion, 13a... Light source, 16... Inner light-receiving optical fiber (part of the first light-receiving device), 17...
- (First) photoelectric conversion element, 19... Outer light receiving optical fiber (part of second light receiving device), 20... (Second) photoelectric conversion element, 24... Inspection device, 50. ... Projected light, 51... Reflected light. ``1A Agent Patent Attorney Yue Shuto Department 11 ``Fig.

Claims (1)

[Claims] (1) A lighting device equipped with a large number of cold light sources arranged in an annular shape, capable of simultaneously projecting projection light from directly above along substantially the entire circumference of the normal flange portion of a metal can body; A first light receiving device having a first photoelectric conversion element group arranged in an annular shape so as to be able to receive reflected light from a normal flange portion is provided inside the device, and a flange bent portion is provided on the outside of the light projecting device. The second part is arranged in an annular manner so as to be able to receive only the reflected light from the second part.
1. An inspection device for a flange portion of a metal can body, comprising a second light receiving device having a group of photoelectric conversion elements.