JPH08175006A - Laser marking apparatus for can - Google Patents

Abstract

PURPOSE: To rapidly and efficiently carve an identifier capable of certainly identifying a painting apparatus applying painting to the inner surface of a can body in the surface of a can. CONSTITUTION: A laser marking apparatus for a can comprises marker heads 35a-35f irradiating the surface of the can 31 arranged at the midway position of a can manufacturing line 32 with laser beams L to carve an identifier in the surface of the can 31, laser oscillators 36 arranged at a remote position with respect to the manufacturing line 32 and the optical fiber cables 37 connecting the laser oscillators 36 and the marker heads 35a-35f. The laser oscillators 36 are isolated from the vicinity of the manufacturing line 32 not only to make the periphery of manufacturing line 32 well-ordered but also to arrange the laser oscillators 36 under the optimum operation environment and laser beams L are efficiently transmitted to the marker heads 35a-35f by the optical fiber cables 37.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a laser marking device for a can which stamps an identifier on the surface of the can that is distributed in a manufacturing line.

[0002]

2. Description of the Related Art Generally, as shown in FIG. 7, a can manufacturing line has a metal plate 2 as a raw material fed from an uncoiler 1.
Punching step 3 to form a large-diameter shallow-bottom cup shape, deep-drawing and ironing step 4 to form the cup-shaped can body into a small-diameter deep-bottomed bottomed cylinder shape, and the open end of the can body A trimming step 5 for cutting the cut can body, a washing step 6 for washing the cut can body, a printing step 7 for applying a base coating and printing to the outer surface of the washed can body, and a can body for printing the outer surface. Inner surface coating step 8 of applying an inner surface to the inner surface, and necking and flanging step 9 of forming a flange by reducing the diameter of the open end of the can body printed and painted on the inner and outer surfaces.
And an inspection step 10 for inspecting the formed can body.

In FIG. 7, reference numeral 11 is a cupping press, 12 is a DI press, 13 is a trimmer, 14 is a washer, 15 is a base coater, 16 is a base coater oven, 17 is a printer, 18 is a printer oven, and 19 is a coating device. , 20 is an inner coating oven, 21 is a necker flanger, 22 is a pinhole tester, and 23 is a palletizer.

In these steps, the can is subjected to each processing / treatment while being conveyed at a high speed by a conveying means such as a star wheel or a conveyor. Further, among these steps, in the deep drawing and ironing step 4 and the inner surface coating step 8, the working time required for one can is longer than that of the other steps, so a plurality of DI presses 12 and coating devices 19 are provided. Is typically done using.

That is, a large number of cans are conveyed at high speed, and in the deep drawing and ironing step 4, each DI press 12
In the inner coating process 8, each coating device 19
After being branched into two parts and subjected to each work, they are merged again and transported. This allows each DI
Since the number of cans that the press 12 or each coating device 19 has to handle is reduced, a large number of cans can be manufactured at high speed without reducing the manufacturing speed of the entire manufacturing process.

By the way, as in the above manufacturing process, a plurality of D
When the I press 12 or the coating device 19 is used, it is desirable that the DI press 12 and the coating device 19 that actually worked the can in those steps can be specified thereafter. That is, in the deep drawing and ironing process 4, the inner surface coating process 8 such as wear and breakage of the die is performed.
In the case of the above, in the case where some trouble such as paint supply shortage, nozzle clogging, etc. occurs, the can and the DI press 12 or the coating device 19 are associated with each other so that the machine in which the trouble has occurred can be immediately investigated. Need to be kept.

Conventionally, associating a deep-drawn and ironed can with a DI press 12 that has been processed is such that the die itself of the DI press 12 forms minute irregularities different for each DI press 12. It was done by configuring. This is because even after the printing process 7 and the like arranged in the subsequent stage of the deep drawing and ironing process 4 are carried out, the DI press 12
In order to be able to specify, the unevenness was usually provided on the bottom of the can or the like which is inconspicuous.

[0008]

However, it has been difficult to associate the coating device 19 in the inner surface coating step 8 with the can body having the inner surface coated by the coating device 19. That is, since the coating device 19 does not have a mold as in the DI press 12, it is not possible to form irregularities on the can body. Further, it is difficult to provide a special process such as providing unevenness for each coating device 19 from the viewpoint of shortening the process. Therefore, the identifier is formed quickly and accurately so as not to affect the manufacturing speed of the can body. It is desired to do.

From this point of view, it is possible to provide an ink jet or the like in each coating device 19 and apply ink to the surface of the can body to draw an identifier for identifying each coating device 19. However, in the latter stage of the inner surface coating step 8, since a transparent coating is usually performed on the bottom of the can such as bottom spraying, even in the case of this method, the identifier drawn with ink is bleeding and the distinguishability is improved. It is thought that there is an inconvenience that it is damaged.

Furthermore, the identification is not limited to the above-mentioned application of the coating device 19, but the identification is made by printing or coating even when managing the metal plate 2 as a raw material, the manufacturing date, the lot, and the like. It is desired to form an identifier on the surface of the can that does not damage the.

The present invention has been made in view of the above-mentioned circumstances, and is of a can that can be engraved with an identifier capable of surely performing various identifications, such as a coating device in which a can body is internally coated. An object of the present invention is to provide a laser marking device.

[0012]

In order to achieve the above object, the present invention provides a marker which is arranged at an intermediate position in a can manufacturing line and which is irradiated with a laser beam for marking an identifier on the surface of the can. A head comprising a head, a laser oscillator arranged at a remote position with respect to the manufacturing line, and an optical fiber cable for connecting the laser oscillator and the marker head to transmit laser light from the laser oscillator to the marker head. A laser marking device is proposed.

In the above laser marking apparatus, in the case where the can manufacturing line is one in which a plurality of cans conveyed by the conveying means are branched into a plurality of coating devices for inner surface coating and then joined again to the conveying means. In addition, it is effective to dispose the marker head at an intermediate position of the transport path connecting the transport means and the coating device. Also,
The marker head may be arranged on the production line so as to face the can bottom of the can.

[0014]

With the laser marking device for a can according to the present invention, the laser light generated in the laser oscillator arranged at a remote position from the manufacturing line is transmitted through the optical fiber cable and emitted from the marker head. To be done.
The marker head is arranged at an intermediate position in the can manufacturing line, and the laser beam is emitted to the can to mark the identifier on the surface of the can.

The surroundings of the manufacturing line are likely to be in a narrow environment where various processing devices are arranged close to each other. However, by arranging the laser oscillator at a remote position from the manufacturing line, the marker arranged on the manufacturing line is compact. Only the head is provided, and the periphery of the production line can be tidied.
Further, since the laser oscillator is arranged at a remote position from the periphery of the manufacturing line which is in a high temperature state by an oven or the like arranged in the latter stage of the printing process and the inner surface coating process, the operating environment can be maintained in an optimum state. In this case, the laser light generated by the laser oscillator is efficiently transmitted by the optical fiber cable.

Further, in the above laser marking device for a can, if the marker head is arranged at an intermediate position of the transport path connecting the transport means and the coating device, the can and the can are internally coated. It is possible to associate the coating device with the identifier, so that the coating device in which a failure has occurred can be quickly identified.

Further, in the above laser marking device for a can, if the marker head is arranged on the manufacturing line so as to face the can bottom of the can, it is relatively inconspicuous and distinctive by printing or the like. It is possible to manufacture cans that have an identifier on the bottom of the can that is not reduced. In this case, since the can bottom is relatively flat, the fluctuation of the focus position of the laser light is small, high positioning accuracy with respect to the marker head is not required, and the identifier can be easily engraved.

[0018]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a laser marking device for a can according to the present invention will be described below with reference to FIGS. As shown in FIG. 1, the laser marking device 30 of the present embodiment, for example, in a manufacturing line 32 of an aluminum can 31 (hereinafter referred to as an aluminum can), is conveyed at a high speed and in large quantities by a mass conveyor 33 (conveying means). Marker heads 35a, 35b, 35c, 35d arranged on the respective transport paths 34 for transporting the plurality of incoming aluminum cans 31 to the plurality of coating devices 19 in the inner surface coating step 8.
35e and 35f, a laser oscillator 36 disposed at a remote position with respect to the manufacturing line 32, for example, in a room of a separate building whose temperature is adjusted, and an optical fiber cable connecting the laser oscillator 36 and the marker heads 35a to 35f And 37.

Each of the marker heads 35a to 35f is attached so that the emission port for emitting the laser beam L is directed toward the inside of the transport path 34. In addition, the aluminum can 31, which is circulated in the transport path 34, has the can bottom 31 a at the marker head 35.
It can be moved so as to face the emission ports a to 35f.

The marker heads 35a to 35c are shown in FIG.
In the example shown in, the first lens 38 for converting the laser light L transmitted through the optical fiber cable 37 into parallel light.
And a second lens 39 for condensing the parallel light so as to focus the parallel light at a predetermined distance. Therefore, FIG.
Approximately 0.2 mm in diameter as shown in (a), (b) and (c)
An aluminum can 31 with an identifier 41 consisting of one dot symbol 40
It can be formed on the surface of the can bottom 31a.

3A to 3C show identifiers 41 formed by the marker heads 35a to 35c, respectively, and the aluminum cans 31 can be classified according to their radial positions. Reference numeral 42 in the drawing denotes a bottom rim portion.

In addition, other marker heads 35d to 35f
In the example shown in FIG. 3, the parallel light formed by the first lens 38 is split into two between the first lens 38 and the second lens 39, and the parallel light is split to the second lens 39. It is provided with a prism 43 for incidence. Therefore, the laser light L emitted from the second lens 39 is
As shown in (e) and (f), an identifier 41 composed of two dot symbols 40 having a diameter of about 0.2 mm and an interval of about 0.5 mm can be formed on the surface of the bottom 31 a of the aluminum can 31. Has become.

3 (d) to 3 (f) show the identifier 41 formed by the marker heads 35d to 35f, respectively, so that the aluminum can 31 can be classified by its radial position similarly to the above. It has become.

Furthermore, these marker heads 35a-3
5f is provided with a shutter (not shown) so that the laser light L is emitted / blocked as required. In addition, the transport path 34 corresponding to the coating device 19a
No laser marking device is provided in a. As a result, the unmarked aluminum can 31 is identified as being painted by the painting device 19a.

Therefore, depending on the inner surface coating step 8 configured as described above, the radius consisting of one dot symbol 40 and two dot symbols 40 is provided inside the bottom rim portion 42 of the can bottom 31a of the aluminum can 31. An aluminum can 31 having six kinds of identifiers 41, each of which has a different directional position, is formed.
Including 7 unpainted aluminum cans, 19 coating devices
a can be identified.

The laser oscillator 36 is, for example, a YAG
It is a laser oscillator. Also, the optical fiber cable 3
For example, 7 has a diameter of about 400 μm, and energy loss can be suppressed.

In the present embodiment, each of the marker heads 35a-3a.
One laser oscillator 36 is provided for each 5f, and each of these laser oscillators 36 independently supplies the laser light L. Therefore, with respect to the aluminum can 31 supplied to each coating device 19, the marking work of the identifier 41 is continued regardless of the movement of the aluminum can 31 supplied to the other coating devices 19 and 19a. . The aluminum cans 3 supplied to all the coating devices 19
In the case where the behavior of No. 1 can be precisely controlled, each marker head 35a ...
A method of allocating the laser light L to 35f in a time division manner may be adopted.

Also, a single or a small number of laser oscillators 3
6, the laser light L is distributed to each of the marker heads 35a to 35f in a time-sharing manner at an extremely short cycle (for example, 10 Hz or more), and the behavior of the aluminum can 31 is monitored on the side of each coating device 19 as necessary. With a shutter or the like, at a cycle longer than the above (for example, 5 Hz or less), the aluminum can 31
The laser light may be irradiated toward the target.

The inner surface coating step 8 will be described below. In the inner surface coating step 5, the bottomed cylindrical aluminum can 31 that is transported by the mass conveyor 33 and branched into each transport path 34 is supplied to the coating devices 19 and 19a. Each of the coating devices 19 and 19a has a turntable 44 such as a star wheel and a suction mechanism (not shown), and holds each aluminum can 31 in the pocket 44a of the turntable 44 by the suction mechanism. While sending it intermittently. In the meantime, paint is sprayed into the aluminum can 31 from a paint injection port (not shown) to perform internal coating.

Therefore, the aluminum can 31 in the transfer path 34 arranged between the mass conveyor 33 and the coating devices 19 and 19a is also intermittently transferred in synchronization with the rotation of the turntable 44. , The laser light L is emitted from the marker heads 35a to 35f at the moment when the aluminum can 31 is stopped.
Is emitted, the identifier 41 is engraved at a desired position on the can bottom 31a. Then, the aluminum can 31 is discharged from each of the coating devices 19 and 19a after the can bottom 31a is coated with a transparent coating by bottom spray.

The aluminum cans 31 discharged from each of the coating devices 19 and 19a are merged again at another mass conveyor 45 (conveying means) and are conveyed into the next inner surface coating oven 20. In this case, the mass conveyor 4
The aluminum cans 31 merged in 5 are mixed with those discharged from all of the coating devices 19 and 19a, but the inner surface of the cans 31 was coated with the identifier 41 stamped on the can bottom 31a. The coating devices 19 and 19a can be quickly specified.

As described above, according to the laser marking device 30 according to the present embodiment, the identifier 41 can be swiftly stamped on the aluminum can 31 supplied to each of the coating devices 19 and 19a. Therefore, the identifier 41 that can quickly identify the coating device 19 or 19a that has been internally coated when a problem occurs
The attached aluminum can 31 can be manufactured.

Further, since the identifier 41 is imprinted on the base material of the aluminum can 31, even when the surface thereof is coated with a transparent material such as bottom spray, it does not bleed like ink and is accurate. The distinctiveness can be retained. Further, since the identifier 41 is formed on the can bottom 31a that is not normally printed, the distinguishability is not reduced by printing or the like, and the visual identification can be performed easily and reliably.

Further, since the identifier 41 is stamped on the can bottom 31a which is relatively flat in the conveying direction of the aluminum can 31, even if the positioning of the aluminum can 31 with respect to the marker heads 35a to 35f is slightly deviated. The identifier 41 can be surely imprinted without changing the focal length.

Further, according to the laser marking apparatus 30 of this embodiment, the laser oscillator 36 is arranged at a remote position from the periphery of the manufacturing line 32, and only the compact marker heads 35a to 35f are arranged in the manufacturing line 32. Therefore, the periphery of the production line 32 can be made orderly. Further, the laser oscillator 36 can be placed in a room in which optimum temperature setting and the like have been made, and an optimum operating environment can be secured. Further, since the laser oscillator 36 and the marker heads 35a to 35f are connected by the optical fiber cable 37, energy loss during transmission can be suppressed to a minimum and the identifier 41 can be marked efficiently.

An identifier 4 consisting of two point symbols 40
1, in addition to the above-described identification method of the radial position and the number thereof, as shown in FIGS.
The two dot symbols 40 are arranged in the radial direction, or as shown in FIG.
As shown in (a) and (b), the new identifier 41 can be configured depending on whether the identifiers are arranged in the circumferential direction. That is, in addition to the three types in which two point symbols 40 are arranged in the radial direction, the two types of aluminum cans in which the point symbols 40 of other identifiers 41 are arranged in the circumferential direction except for the identifier 41 imprinted near the center 31 can be manufactured.

In the above embodiment, the identifier 41
Although the number of the dot symbols 40 constituting the above is two or less, the number is not limited to this, and the coating device 19
When there are many units, it is possible to set three or more. However, as the number of the dot symbols 40 increases, the energy required by the laser oscillator, that is, the power, may increase, and it may be difficult to visually identify it. Therefore, the number of the dot symbols 40 is the minimum required. It is desirable to keep it to the limit.

In the above embodiment, the diameter is about 0.
The dot symbol 40 having a circular shape of 2 mm is used as the identifier 41, but the diameter dimension is not limited to this.
Further, in the identifier 41 composed of the two dot symbols 40, the interval dimension of the dot symbols 40 is set to about 0.5 mm, but this can also be set arbitrarily.

In addition, the two dot symbols 4 in the above embodiment
Instead of 0, for example, as shown in FIGS. 6A to 6C, a directional identifier 4 such as a rectangle, an ellipse, a polygon, etc.
1 may be stamped. Alternatively, a high-density identifier 41 such as a barcode may be stamped. Furthermore, although the identifier 41 is provided on the aluminum can 31,
It goes without saying that it may be applied to steel cans.

The case where the marker heads 35a to 35f are arranged to face the can bottom 31a of the aluminum can 31 and the identifier 41 is provided on the can bottom 31a has been described. However, the present invention is not limited to this, and the side surface of the aluminum can 31 is not limited to this. It may be provided in. In this case, in a can manufacturing process that is performed separately from the manufacturing line 32 of the aluminum can 31, if the identifier 41 is engraved near the opening end of the aluminum can 31 that is to be wound with the can lid, The identifier 41 can be engraved at an inconspicuous position as in the case of forming on the can bottom 31a. In this case, the identifier 41 may be formed on the coating applied to the outer surface of the aluminum can 31.

Although the can barrel has been described, the present invention is not limited to this, and may be applied to a can lid when a coating step is arranged after the press molding process. Furthermore, although it was decided to apply when the identifier 41 of the coating device 19 / 19a is engraved, other applications, such as lot management in the production line 32 of the aluminum can 31, production date, and material metal plate 2 are different. The laser marking device 30 may be applied for any identification such as.

[0042]

As described in detail above, the laser marking apparatus for a can according to the present invention is arranged at an intermediate position in the can manufacturing line and irradiates the can with laser light for marking an identifier on its surface. Since the marker head, the laser oscillator disposed at a remote position from the manufacturing line, and the optical fiber cable connecting the laser oscillator and the marker head are provided, only a compact marker head is installed in the manufacturing line. Therefore, there is an effect that the periphery of the manufacturing line can be made orderly. Also, the laser oscillator can be isolated from the manufacturing line to ensure an optimum operating environment.

Further, the laser light can be efficiently transmitted to the marker head by the optical fiber cable.
Since the identifier is imprinted on the surface of the can with the laser light at a high speed, it is possible to prevent a decrease in the speed of the entire manufacturing line and easily perform various identifications.

Further, in the above laser marking apparatus, when the can manufacturing line branches a plurality of cans conveyed by the conveying means to a plurality of coating devices to apply inner surface coating and join them again to the conveying means, the marker head By arranging in the middle of the conveying path connecting the conveying means and the coating device, the can and the coating device for applying the inner surface coating to the can can be associated with each other by the identifier, and a malfunction or the like occurs. The effect that the coating device can be specified quickly is exhibited. As a result, it is possible to shorten the down time of the production line required from the occurrence of a defect to the repair and improve the production efficiency.

Further, in the above laser marking apparatus, if the marker head is arranged on the manufacturing line so as to face the can bottom of the can, in addition to the above effects, it is inconspicuous in appearance and distinguishable by printing or the like. The effect is that a can having an identifier that does not damage the can can be configured. Moreover, since high positioning accuracy between the marker head and the can is not required, a special positioning mechanism is not required, and moreover, the time required for positioning can be shortened and the identifier can be stamped quickly.

[Brief description of drawings]

FIG. 1 is a schematic view showing an embodiment of a laser marking device for a can according to the present invention.

FIG. 2 is a schematic diagram showing a structure inside a marker head of the laser marking device of FIG.

FIG. 3 is a schematic diagram showing another internal structure of a marker head of the laser marking device of FIG.

4 is a front view showing an example of an identifier engraved on the can bottom by the laser marking device of FIG. 1. FIG.

5 is a front view showing another example of the identifier stamped on the can bottom by the laser marking device of FIG. 1. FIG.

6 is a front view showing another example of the identifier imprinted on the bottom of the can by the laser marking device of FIG. 1. FIG.

FIG. 7 is a schematic view showing a manufacturing process of a can.

[Explanation of symbols]

 L laser light 19 coating device 31 aluminum can (can) 31a can bottom 32 manufacturing line 33/45 carrier means 34 carrier path 35a to 35f marker head 36 laser oscillator 37 optical fiber cable 41 identifier

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Masao Kawanami 1-1, Shintsutsumi Nakadori, Yuki City, Ibaraki Prefecture Mitsubishi Materia Co., Ltd. Inside the Yuki Plant (72) Inoue Nagashige 1-15 No. 15 Kuryotsu, Hiratsuka, Kanagawa Prefecture Sumitomo (72) Inventor Makoto Tani, 1-15, Kuroyomi, Hiratsuka-shi, Kanagawa Sumitomo Heavy Industries, Ltd. Laser Business Center

Claims (3)

[Claims] 1. A marker head, which is arranged at an intermediate position in a manufacturing line of a can and irradiates a laser beam for marking an identifier on the surface of the can, and a laser arranged at a remote position from the manufacturing line. A laser marking device for a can comprising an oscillator and an optical fiber cable for connecting the laser oscillator and the marker head to transmit laser light from the laser oscillator to the marker head. 2. In a can manufacturing line in which a plurality of cans conveyed by a conveying means are branched to a plurality of coating devices to apply an inner surface coating and join the conveying means again, a marker head is used as a conveying means. The laser marking device for a can according to claim 1, wherein the laser marking device is arranged at an intermediate position of a conveying path connecting with a coating device. 3. The laser marking device according to claim 1, wherein the marker head is arranged in the manufacturing line so as to face the can bottom of the can.