Laser engraving device and laser engraving method

Abstract

To be able to mold an object to be molded with an engraved mark with high productivity, on a coil material that is supplied to a press machine that molds a portion of a can, when performing variable engraving for each object to be molded.SOLUTION: A laser engraving device, which performs laser engraving onto a coil material that is supplied to a press machine that molds a portion of a can, comprises a feed mechanism that feeds the coil material at set speed, a laser head that performs engraving on to each object to be molded by emitting a laser beam to the coil material to be fed at the set speed, and a data communication part that switches engraving data on the laser head. The data communication part collectively switches a plurality of engraving data that are engraved on a plurality of objects to be molded, and the laser head continuously engraves the plurality of engraving data on prescribed positions of the coil material.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present invention relates to a laser marking device and a laser marking method for performing laser marking on a coil material that is fed to a press machine that forms a part of a can. [Background technology]

[0002] Cans are often decorated with information, pictures, etc., to provide information about individual products or to advertise individual products. The opening tab of a can lid is a part that is particularly noticed by people holding the can when opening it, and in the case of a stay-on tab type, the tab is not separated from the main body of the can lid even after opening, so that by providing information, pictures, etc., to a part of the tab, it is possible to effectively enhance the decoration and provide information about the individual product.

[0003] To add information or a design to a can, laser engraving (laser marking) is used, in which a laser beam is irradiated directly onto the coating applied to the surface of the can or onto the surface of the can to engrave the information. By using laser engraving for the engraving on the tab described above, highly precise engraving can be performed in a relatively small space. A device (laser engraving device) that performs laser engraving on coil material that forms part of a can has a laser head disposed between a roll of coil material in which a strip-shaped plate material is wound into a roll and a press machine to which the coil material unwound from the roll is supplied, and laser engraves a predetermined position on the coil material supplied to the press machine before it is formed by the press machine (see Patent Document 1 below). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Special Publication No. 2015-531684 Summary of the Invention [Problem to be solved by the invention]

[0005] Such laser marking devices are required to perform variable marking, which marks different contents for each molding object. To perform variable marking, it is necessary to communicate marking data for each molding object and switch the operating program of the laser head. In this case, it takes time to switch the marking data, and the time per press stroke to send the coil material to the press is limited by the total time taken by the laser head to actually mark the contents of one marking data and the time required to switch the marking data for each molding object. This limitation has been an obstacle to molding objects with markings with high productivity.

[0006] The present invention aims to address such problems, i.e., to enable highly productive molding of objects with markings when applying variable markings for each object to be molded on coil material supplied to a press machine that molds a part of a can. [Means for solving the problem]

[0007] In order to solve such problems, the present invention has the following configuration. This is a device that performs laser engraving on coiled material fed to a press machine that forms a part of a can. The device has a feed mechanism that feeds the coiled material at a set speed, and irradiates the coiled material fed at the set speed with a laser beam to engrave the material for each molding object. The marking data for multiple molding objects is continuously recorded at the specified position of the coil material. and a data communication unit that switches marking data of the laser head, The above Switching between multiple engraving data for multiple molding objects at once The time required for one communication to switch the marking data collectively and the time required for consecutively marking each of the plurality of molding objects is set so as to be shorter than the time required for multiple strokes of the press machine, the number of which is the same as the number of the plurality of molding objects. A laser engraving device characterized by

[0008] This is an engraving method for laser engraving on a coil material fed to a press machine for forming a part of a can, in which a laser head irradiates a laser beam on the coil material fed to the press machine at a set speed, and for each molding object, Marking data for multiple molding targets is continuously added to the coil material at the specified position.The method includes a laser engraving step for engraving, and a data communication step for switching the engraving data of the laser head, , the above A plurality of marking data to be marked on a plurality of molding objects is switched at once, The time required for one communication to switch the marking data collectively and the time required for consecutively marking each of the plurality of molding objects is set so as to be shorter than the time required for multiple strokes of the press machine, the number of which is the same as the number of the plurality of molding objects. A laser engraving method characterized by: Effect of the Invention

[0009] The laser engraving device of the present invention, which has these characteristics, can switch between multiple engravings for each molding object at once, so that even when performing variable engraving for each molding object, the time per press stroke can be set to a short time, making it possible to mold objects with engravings with high productivity. [Brief description of the drawings]

[0010] [Figure 1] FIG. 1 is an explanatory diagram showing a schematic configuration of a system for forming a can end with a tab. [Diagram 2] FIG. 2 is an explanatory diagram showing the configuration of a laser marking device. [Diagram 3] 1A and 1B are explanatory diagrams illustrating engraving data switching methods ((a) individual communication method and (b) collective communication method). [Figure 4] FIG. 1 is an explanatory diagram showing an example of a laser engraving method. [Diagram 5] FIG. 5 is an explanatory diagram showing the movement of the marking position in FIG. 4. [Figure 6] 11A and 11B are explanatory diagrams showing another example of a laser engraving method and an operation chart thereof; DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. In the following description, the same reference numerals in different drawings indicate parts with the same function, and duplicated description in each drawing will be omitted as appropriate. In the following description, the tab of a can lid will be described as an example of a molding target, but the present invention is not limited to this, and the object of the present invention is a part of a can, such as a can lid itself, a can body, or a metal cap, which is molded from a coil material.

[0012] First, the schematic configuration of a system for forming can ends with tabs will be described with reference to Fig. 1. In this example, a press (conversion press) 1 is used to form the tabs, process the lids, and join the lids and tabs. The coil material T from which the tabs are formed is a strip of aluminum sheet material, which is pulled out from a roll R wound in a roll shape and fed to the press 1 at a set speed. In the press 1, the tabs are formed on the coil material, and a can end panel P fed by a separate conveyor 2 is processed, and a can end product W with the formed tab joined to the processed can end is sent out from the exit of the press 1.

[0013] In the illustrated example, the press machine 1 is shown as performing a conversion press, but the present invention is not limited to this. The press machine 1 may be configured to form only the tab, and a separate press machine may be used to form the can lid and connect the tab formed by the press machine 1 (which is not separated from the coil material).

[0014] A laser engraving device 10 that applies an engraving to the tab is disposed on the coil material T that is pulled out from the roll R and supplied to the press machine 1. The laser engraving device 10 performs laser engraving on the coil material T before the tab is formed at a predetermined position corresponding to the stroke of the press machine 1.

[0015] As shown in FIG. 2, the laser engraving device 10 includes a feed mechanism 11 (feed roll 11A and tension roll 11B) that feeds the coil material T in the direction of the arrow at a set speed, laser heads 12 (first laser head L1, second laser head L2, and third laser head L3) that irradiate the coil material T fed at the set speed with laser light to engrave each tab to be formed, a control unit 13 that controls the laser head 12, and a data communication unit 14 that switches the engraving data for the laser head 12.

[0016] In the illustrated example, the laser engraving device 10 includes a base 10A, and on the base 10A, a laser irradiation unit 15 equipped with a feed mechanism 11 or a laser head 12 is arranged. Further, the control unit 13 and the data communication unit 14 are arranged in a control panel (not shown) arranged on the base 10A.

[0017] The laser engraving device 10 is equipped with a speed sensor 16 that measures the feeding speed of the coil material T. The speed sensor 16 can use a laser Doppler velocimeter that irradiates the coil material T with laser light to measure the feeding speed of the coil material T non - contact. The output of the speed sensor 16 is transmitted to the control unit 13, and the feeding amount (distance) is calculated from the measured feeding speed. The control unit 13 controls the engraving timing of the laser head 12 according to the output of the speed sensor 16 (the feeding amount of the coil material T) so that engraving is performed at a predetermined position on the coil material T.

[0018] The laser head 12 performs engraving for each individual tab with engraving data switched by the data communication unit 14. In the illustrated example, a plurality of laser heads (three laser heads L1, L2, and L3) are provided, and the data communication unit 14 switches the engraving data of each laser head 12 individually.

[0019] And the data communication unit 14 of the laser engraving device 10 switches the engraving data of the laser head 12 by a collective communication method as shown in Fig. 3(b), rather than an individual communication method as shown in Fig. 3(a). In the case of the individual communication method shown in Fig. 3(a), in order to perform the next engraving (for example, "Engraving 2"), the communication time tc1 required for engraving data switching and the time tw1 actually required to perform one engraving are combined (tc1 + tw1). It is necessary to make the time ts1 between the strokes of the press forming longer (that is, tc1 + tw1 < ts1), so there is a limit to shortening the time ts1 between the strokes, and it is not possible to form tabs with engraving with high productivity.

[0020] In contrast, if the batch communication method shown in Figure 3(b) is used, multiple pieces of marking data (six pieces in the illustrated example) can be switched in one communication time tc2, so the combined time (tc2+tw2) of one communication time tc2 and the time tw2 to perform multiple marks (marking 1 to marking 6) in succession needs to fit within the time required for multiple strokes (stroke 1 to stroke 6), and the time between strokes (ts2) can be set short. This makes it possible to mold tabs with markings with high productivity.

[0021] The multiple engraving data communicated by the batch communication method can include different engraving contents to correspond to each tab. In this case, if the multiple engraving contents include complex engraving that requires a relatively long engraving time, it is possible to include the complex engraving contents without lengthening the stroke time by combining it with engraving contents that require a short engraving time.

[0022] FIG. 4 shows a laser marking method in which three laser heads 12 (L1, L2, L3) are used to form a tab with an engraving with high productivity. In this example, the marking positions (F1, F2, F3) assigned to each of the multiple laser heads 12 (L1, L2, L3) are sequentially divided along the feed direction of the coil material T. In the illustrated example, a position where multiple marks (six marks) are continuously made is defined as one section, and the section (F1) assigned to the laser head L1, the section (F2) assigned to the laser head L2, and the section (F3) assigned to the laser head L3 are sequentially arranged along the feed direction of the coil material T. In other words, the section F2 is set next to the section F1 on the opposite side of the feed direction of the coil material T, and the section F3 is set next to the section F2.

[0023] For setting the marking positions on the coil material T in this way, multiple laser heads 12 (L1, L2, L3) are arranged along the longitudinal direction of the coil material T, and the marking areas E1, E2, E3 of each laser head L1, L2, L3 are set in a fixed state along the longitudinal direction of the coil material T. The marking area here refers to the range in which marking can be performed by one laser head.

[0024] Here, each laser head L1, L2, L3 switches multiple (6) pieces of marking data at once, and when the section (F1, F2, F3) of the marking position that it is responsible for reaches a predetermined position in its own marking area (E1, E2, E3), it performs multiple (6) marks in succession at the predetermined position within that section.

[0025] To explain the operation of laser head L1 individually, the coil material T is fed in the direction of the arrow in the figure, section F1 enters marking area E1, and immediately after multiple markings are made in succession by laser head L1, section F2 handled by laser head L2 and section F3 handled by laser head L3 enter marking area E1 in sequence (sections F2 and F3 have already been marked in the previous stage). The operation of laser heads L2 and L3 is similar.

[0026] Figure 5 shows the movement of the marking position in the example shown in Figure 4. The movement distance of the coil material T depends on the press stroke, and the movement distance of the coil material T in one stroke is set to S1 in the example shown. As shown in the figure, the number of strokes until one marking position section (F1) enters and exits one marking area (E1) is six strokes, and this number of strokes and the number of marking data within one marking position section (F1) are set to be the same.

[0027] Then, for one laser head 12, while the section F1 of the marking position that it is responsible for passes through the marking area E1 of its own laser head, it marks the marking data for multiple pieces (six pieces) to be marked in each section, and switches the marking data before the section of the next marking position that it is responsible for enters the marking area of ​​its own laser head.

[0028] According to this marking method, multiple laser heads are arranged along the feed direction of the coil material T, and the marking positions on the coil material T that each laser head is responsible for are divided sequentially along the feed direction of the coil material T, so that variable marking for each tab can be performed smoothly even if the press stroke time is set short.

[0029] Fig. 6 shows another marking method in which three laser heads 12 (L1, L2, L3) are used to form tabs with markings with high productivity. In this example, multiple laser heads 12 (L1, L2, L3) are arranged for each row of tabs to be formed on the coil material T, and the marking positions assigned to each laser head are divided for each row of tabs to be formed. Specifically, marking area E1 of laser head L1, marking area E2 of laser head L2, and marking area E3 of laser head L3 are aligned in parallel to the three rows of tabs to be formed, respectively.

[0030] According to this, in order for each laser head (L1, L2, L3) to continuously mark multiple pieces of marking data (for example, six pieces) at a predetermined position, it is necessary to fit the time tw for multiple markings (marking 1 to marking 6) and the communication time tc for switching multiple pieces of marking data for the next marking all at once, within the time for multiple strokes (six strokes), as shown in the operation chart in Figure 6.

[0031] This means that one laser head is assigned to each row of tabs being formed, so the marking position for each row can be corrected for each laser head.It also makes it easier to identify the laser head that needs to be corrected if an engraving error occurs, providing advantages in terms of control and management.

[0032] As described above, according to the tab marking device and method of the embodiment of the present invention, variable marking can be smoothly performed on the coil material even when the time between strokes of the tab forming press is shortened to increase productivity. Therefore, it becomes possible to mark the coil material with various patterns and information while changing them as needed without reducing productivity.

[0033] Although the embodiments of the present invention have been described in detail above with reference to the drawings, the specific configuration is not limited to these embodiments, and the present invention includes design changes and the like that do not deviate from the gist of the present invention. In addition, the above-mentioned embodiments can be combined by utilizing each other's technologies as long as there are no particular contradictions or problems in the purpose, configuration, etc. [Explanation of symbols]

[0034] 1: Press machine, 2: Conveyor, 10: Laser engraving device, 10A: Base, 11: Feed mechanism, 12(L1, L2, L3): Laser head, 13: control unit, 14: data communication unit, 15: laser irradiation unit, 16: Speed ​​sensor, T: Coil material, R: Roll

Claims

1. An apparatus for laser marking a coil material fed to a press machine for forming a part of a can, comprising: A feed mechanism that feeds the coil material at a set speed; a laser head that irradiates a laser beam onto the coil material fed at a set speed, and continuously marks marking data for a plurality of molding objects at predetermined positions on the coil material for each molding object; A data communication unit for switching the marking data of the laser head, The data communication unit collectively switches marking data for a plurality of objects to be marked on the plurality of objects to be molded, and limits the time required for one communication to collectively switch the marking data and the time required for consecutively marking each of the plurality of objects to be molded so that the time required for one communication is shorter than the time required for multiple strokes of the press machine, the number of which is the same as the number of the objects to be molded. A laser engraving device characterized by:

2. 2. The laser marking device according to claim 1, wherein the plurality of pieces of marking data include different marking contents.

3. 3. The laser marking device according to claim 1, further comprising a plurality of said laser heads, said data communication section switching a plurality of pieces of marking data for each of said plurality of laser heads.

4. 4. The laser marking device according to claim 3, wherein the marking positions assigned to each of the multiple laser heads are divided sequentially along the feed direction of the coil material, and for each laser head, marking data for multiple marks to be engraved in each division while the division of the marking position assigned to that laser head passes through the marking area of ​​that laser head, and the marking data is switched before the division of the next marking position assigned to that laser head enters the marking area of ​​that laser head.

5. 5. The laser marking device according to claim 4, wherein a plurality of said laser heads are arranged along the longitudinal direction of said coil material.

6. 4. The laser marking device according to claim 3, wherein the marking positions assigned to each of the plurality of laser heads are divided for each row of forming objects to be formed on the coil material.

7. 7. The laser marking device according to claim 1, wherein the object to be molded is a tab for a can lid.

8. A method for laser engraving a coil material supplied to a press machine for forming a part of a can, comprising the steps of: a laser engraving process in which a laser head irradiates a laser beam onto the coil material fed to the press at a set speed, and engraves engraving data for a plurality of molding objects in succession at predetermined positions on the coil material for each molding object; A data communication step for switching the marking data of the laser head, In the data communication step, a plurality of marking data to be marked on the plurality of molding objects are collectively switched, The time required for one communication to switch the marking data collectively and the time required for consecutively marking each of the plurality of molding objects is set so as to be shorter than the time required for multiple strokes of the press machine, the number of which is the same as the number of the plurality of molding objects. A laser engraving method characterized by:

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