Embossing device, embossing method, and embossed can

To provide an embossing device, an embossing method and an embossed can which are capable of conducting embossing having a non-shaped section and an arbitral number of embossed areas, and are capable of improving quality or productivity.An embossed can 10 is a double-embossed surface can in which on a can barrel 101 a first pattern 104 is printed; a first concave part 105 is formed in the state that it is so positioned as to almost conform to the first pattern 104; a second pattern 106 is printed at a position which is distant in the circumferential direction with the non-shaped section therebetween; and a second concave portion 107 is formed in the state that it is so positioned as to almost conform to the second pattern 106.

RELATED APPLICATIONS

The present application is National Phase of International Application No. PCT/JP2010/003588 filed May 28, 2010, and claims priority from Japanese Application No. 2009-136094 filed Jun. 5, 2009.

TECHNICAL FIELD

The present invention relates to an embossing device, an embossing method and an embossed can.

BACKGROUND ART

In recent years, because of diversification in design, improvement in strength of a can barrel with a decrease in thickness of a can barrel or for other reasons, a can of which the can barrel has been processed (embossed) to have convex parts and/or concave parts thereon (embossed can) has been developed and put on the market.

If processing is conducted such that convex parts and/or concave parts are formed so as to conform to patterns, characters or the like (hereinafter, they are named generically as “patterns” in this specification) which have been printed on a can barrel, the design of the can body is enhanced. Therefore, processing has been conducted to form concave parts and/or convex parts in at least part of a pattern such that they conform to the pattern.

In general, an embossed can means a can which is shaped while being so positioned to a prescribed design (including a design composed of concave parts and/or convex parts, with no pattern being printed).

For example, Patent Document 1 discloses a technology of a can characterized in that a pattern is printed on the outer peripheral surface of a can barrel and at least part of the pattern is processed to have convex parts and/or concave parts so as to be positioned to the pattern, and two or more positioning marks for positioning the pattern to a predetermined position are formed on the outer peripheral surface.

Further, Patent Document 2 discloses a technology of a method for producing an embossed can body in which a pattern is printed on the outer peripheral surface of a cylindrical can barrel, and, at least part of the pattern is subjected to embossing to have convex parts and/or concave parts so as to be positioned to the pattern, wherein a plastic processing step of forming a plastically deformed part by conducting deformation processing on the part of outer surface of a can barrel is provided prior to an embossing processing step in which positioning to a pattern is conducted and convex parts and/or concave parts (embossing) are formed.

Patent Document 3 discloses a method of processing a can barrel in which predetermined processing is conducted on a barrel of a can body having a barrel and a bottom provided on the one side of this barrel, wherein a stopping mark is provided on the downstream side of the rotation direction and a confirmation mark is provided on the upstream side of the rotation direction are provided on the barrel as positioning marks, a conformation sensor is provided on the upstream side of the rotation and a stopping sensor is provided on the downstream side of the rotation in the positioning step for conducting rotational positioning, when the stopping mark is detected by the confirmation sensor, the rotation of the can barrel is slowed down and, when the stopping mark is detected by the stopping sensor, the can barrel is stopped, and when the rotation of the can barrel is stopped, it is determined whether the rotational positioning of the can barrel is accurately conducted or not by whether the confirmation mark is detected by the confirmation sensor or not.

Further, Patent Document 4 discloses a technology of positioning a printed design of a can barrel in which, before a can barrel is processed in conformity to a design which has been printed on the outer surface of the can barrel beforehand, respective cans which are continuously transferred in the state that the printed design is positioned at a random position are rotated in the circumferential direction of the can barrel at a high speed and then a can rotation speed is lowered at the timing when a large mark printed on the can barrel is detected by a sensor, successively, rotation of the can is stopped when a small mark printed on the can barrel is detected, whereby positioning of the printed design is conducted.

RELATED ART DOCUMENTS

Patent Documents

SUMMARY OF THE INVENTION

Problems to be Solved by the Invention

However, in the technology of each of the above-mentioned patent documents, a match mark (mark for positioning) provided on the can barrel is detected, the can barrel is rotated by a driving means such as a stepping motor, thereby to conduct positioning of the can barrel. As a result, the rotation of the can barrel is stopped. Subsequently, the can barrel, which is rotatable held, is subjected to embossing while being rotated by engaging between the convex parts and concave parts of the inner roll and the outer roll. At this time, while the inner roll and the outer roll are rotated at a circumferential speed of several hundreds mm/sec, the can barrel which has been stopped rotating rotates almost instantly at a circumferential speed of several hundreds mm/sec by being engaged between the convex parts and the concave parts of the inner roll and the outer roll. Therefore, variations in embossing position relative to the design are larger than positional variations of the can barrel relative to the design. That is, in order to attain further improvement in embossing position accuracy relative to the design, it is required to reduce significantly and effectively variations in embossing position which occur at the time of engagement.

Further, normally, in an adjustment operation in which the embossing position is adjusted to the design, it was necessary to move a positioning sensor manually in the circumferential direction of a can to conduct position adjustment. Since this position adjustment requires accuracy of 0. several mm or less, a long period of time is taken to adjust the embossing position to the design. That is, it is necessary to improve productivity or the like.

Further, in canned coffee or the like, the design of a can is important since it affects greatly the sales or the like. Therefore, a technology which is capable of realizing an innovative design has been demanded. For can manufacturers, to establish a technology of capable of realizing an innovative design to meet the demand of customers is significantly important in order to allow them to be differentiated from other manufactures.

For example, in conventional technologies, it was impossible to produce an embossed can having two embossed sections which are distant from each other in the circumferential direction with a non-shaped section (hereinafter, appropriately referred to as the “double-embossed surface can”) (seeFIG. 7).

The reason therefor is that, as mentioned above, the can barrel which has been positioned and has stopped rotating rotates almost instantly at a circumferential speed of several hundreds mm/sec by being engaged in convex parts and concave parts of the inner roll and the outer roll when embossing of the first surface (“EMBOSS”) is conducted. However, in a non-shaped section (between the “EMBOSS” and “NEWCAN”), the inner roll and the outer roll cannot engage the can barrel since no concave parts and convex parts are formed, and hence, the can barrel is stopped (or slowed down), and as a result, embossing of the second surface (“NEWCAN”) cannot be conducted at a predetermined position.

The present invention has been made in order to solve the above-mentioned problem, and is aimed at providing an embossing device, an embossing method and an embossed can which enable embossing having a non-shaped section and an arbitral number of embossed areas and are capable of improving quality, productivity or the like.

Means for Solving the Subject

In order to solve the above object, the embossing device of the present invention is an embossing device which comprises an embossing turret for conducting embossing on a can barrel, wherein the embossing turret is provided with:

an inner roll and an outer roll which revolve and rotate on its axis around the rotational shaft in a synchronized way;

a holding means which revolves around the rotational shaft while conducting the predetermined contact and retract movement and the predetermined swing movement, thereby to allow the can barrel to rotatably hold;

a driving means which allows the can barrel which is held by the holding means to rotate on its axis;

a sensor which detects a match mark on the can barrel;

an encoder which is attached to the rotational shaft; and

a rotational positioning controller which receives signals from the sensor and the encoder and controls the driving means based on these signals;

wherein embossing is conducted on the can barrel in the state where the can barrel is rotated on its axis at the same circumferential speed as that of the inner roll.

Further, the embossing method of the present invention is an embossing method in which embossing is conducted on a can barrel by using an embossing turret of an embossing device, which comprises the steps of:

positioning the can barrel which is held by the holding means of the embossing turret between the predetermined positioning start position and the predetermined positioning position while allowing the can barrel to rotate on its axis; and

embossing the can barrel which has been positioned and is rotating on its axis in the state where the can barrel is allowed to rotate at the same circumference speed as the circumference speed of the rotation on its axis of the inner roll.

Further, the embossed can according to the present invention is an embossed can which is embossed by the embossing method according to claim7.

Advantageous Effects of the Invention

According to the embossing device, the embossing method and the embossed can of the present invention, it is possible to conduct embossing which has a non-shaped section and an arbitral number of embossed areas and also to improve quality and productivity. In particular, in the case of a double-embossed surface can, it is possible to realize an innovative design, and as a result, to improve the additional value.

MODE FOR CARRYING OUT THE INVENTION

One Embodiment of an Embossing Device, an Embossing Method and an Embossed Can

FIG. 1shows a schematic view of an embossing device according to one embodiment of the present invention.

InFIG. 1, the embossing device1of this embodiment has a configuration in which, on a base11, a can barrel supply turret12, a heating turret13, a can barrel transfer turret14, an embossing turret2which conducts embossing on a can barrel101, a can barrel transportation turret15or the like.

Further, since other configurations than the embossing turret2are almost similar to those of the embossing device disclosed in the above-mentioned Patent Document 3, a detailed explanation thereof is omitted.

In the embossing device1, the can barrel supply turret12supplies the can barrel101to a heating turret13.

The heating turret13has a high-frequency coil131, and heats the can barrel101while allowing it to be rotated on its axis. As a result, damage or peeling by embossing of a coating, a film or the like of the inner surface or the outer surface of the can barrel101can be effectively prevented.

Here, the heating turret13may supply the can barrel101to the can barrel turret14after positioning by detecting a match mark102of the can barrel101. By doing this, the can barrel101which has been positioned is transported in the state that the rotation on its axis is stopped. Although the can barrel101slightly rotates by transfer or the like at the can barrel transfer turret14, it is supplied to the embossing turret2in the state that it directs to almost the fixed range direction. Therefore, the time required for positioning in the embossing turret2is shortened, and a high-speed operation becomes possible. As a result, the productive capacity of the embossing device1can be enhanced.

Further, the can barrel transfer turret14supplies the can barrel101which has been heated and positioned to the embossing turret2.

FIG. 2is a schematic view for explaining the relationship between the inner roll, the outer roll and the can barrel of the embossing device according to one embodiment of the present invention.

InFIG. 2, the embossing turret2has a configuration in which a plurality of inner rolls31and outer rolls32(respectively 16 in this embodiment), a holding means4provided such that it corresponds to each inner roll31, a stepping motor43provided in each holding means4, a sensor45provided in each holding means4, an encoder22which is attached to a rotational shaft21, a rotational positioning controller5for controlling the stepping motor43or the like are provided.

The embossing turret2of this embodiment differs from the embossing part (embossing turret) disclosed in the above-mentioned Patent Document 3 in that it is provided with the encoder22and the rotational positioning controller5. Other configurations of the embossing turret2are almost similar to those of the above-mentioned embossing part, and hence, a detailed explanation thereof is omitted.

The inner roll31and the outer roll32are arranged at an equal interval around the rotational shaft21, and are respectively attached to the two shafts which rotate in a synchronized manner with the rotational shaft21by a planet gear.

FIG. 3Ais a schematic plan view for explaining the outer roll of the embossing device according to one embodiment of the present invention.

FIG. 3Bis a schematic view for explaining the outer roll of the embossing device according to one embodiment of the present invention, showing a developmental view taken by an arrow A-A.

InFIG. 3AandFIG. 3B, the outer roll32has two embossing regions (that is, a first embossing region33and a second embossing region34) which are distant from each other in a circumferential direction with a non-shaped section35being therebetween. In the first embossing region33, a convex part corresponding to the character “EMBOSS” is formed, and in the second embossing region34, a convex part corresponding to the character “NEWCAN” is formed.

Although not shown, almost as in the case of the outer roll32, the inner roll31has two embossing regions which are distant from each other in a circumferential direction. In the first embossing region, a concave part corresponding to the character “EMBOSS” is formed, and in the second embossing region, a concave part corresponding to the character “NEWCAN” is formed.

FIG. 4shows a schematic side view of the holding means of the embossing turret of the embossing device according to one embodiment of the present invention.

InFIG. 4, the holding means4is provided with a base41, a chuck42, a stepping motor43, a can pocket (can-supporting means)44, a sensor45and the like.

The base41is arranged at an equal interval around the rotational shaft21, and is attached to a shaft which swings in a synchronized manner with the rotational shaft21by a cam mechanism. Specifically, the base41moves as follows: It contacts and retracts the inner roll31by a sliding body, a sliding cam mechanism or the like. Further, by a cam mechanism for swing movement using the cam element23, it swings in a direction in which the can barrel101is pushed to the inner roll31.

The chuck42has an almost cylindrical shape, and a magnet or the like is embedded in the upper surface thereof. This chuck42is rotatably attached to the base41, and rotates by means of the stepping motor43as the driving means. The can pocket44has a plurality of can barrel mounting rollers, magnets and the like.

The sensor45is attached to the supporting member for the can pocket44, and detects the match mark102of the can barrel101which is held by the chuck42.

The holding means4with the above-mentioned mechanism revolves around the rotational shaft21while conducting the predetermined contacting and retracting movements and swing movement, and holds the can barrel101such that its can rotate on its axis. Further, the stepping motor43allows the can barrel101which is held by the chuck42to rotate on its axis.

Further, the stepping motor43is used in order to allow the can barrel101to rotate. The means to rotate the can barrel101is not limited to the stepping motor43. For example, a servo motor, a motor provided with an encoder or the like which can control the rotation speed can be used.

The can barrel101of this embodiment has a bottomed cylindrical shape, and has a rectangular match mark102at one location of the side.

The shape or quantity of the match mark102is not limited to those mentioned above. Further, the can barrel101is described as the can barrel for a two-piece can, but the application of the can barrel101is not limited to a two-piece can. For example, the can barrel101can also be applied to a three-piece can in which a can bottom is provided at one side of the barrel.

Further, the encoder22is attached to the rotational shaft21, and normally, an encoder having a dissolving power of several hundreds to several thousands pulses is used. In this embodiment, by attaching the encoder22to the rotational shaft21, almost all controls can be conducted by the output pulse of the encoder22.

FIG. 5is a schematic block diagram for explaining a rotational positioning controller of an embossing turret of the embossing device according to one embodiment of the present invention.

InFIG. 5, the rotational positioning controller5receives detection signals from the sensor45and signals from the encoder22(Z-phase pulse signals and pulse signals), and based on these signals, control pulse signals are output to the driver46, and the driver46controls the stepping motor43.

In this embodiment, the rotational positioning controller5has a calculation processing part51, a machine position detection part52and a pulse control part53.

In correspondence with each holding means4, 16 rotational positioning controllers5are provided.

The calculation processing part51has a CPU (central processing unit) or the like, and is connected with the machine position detection part52, the pulse control part53and the sensor45. This calculation processing part51occasionally receives the positional (machine angle) information of the corresponding inner roll31. Further, when it receives from the sensor45detection signals that the match mark102has been detected, it obtains the amount of positional variations of the can barrel101which is held, and outputs control information for correcting the amount of variations to the pulse control part53.

The machine position detection part52receives Z-phase pulse signals and pulse signals from the encoder22, and by counting pulse signals after receiving the Z-phase pulse signals, the position of the inner roll31(machine angle) is calculated. This machine position detection part52outputs the position (machine angle) information or the like of the inner roll31, which has been calculated, to the calculation processing part51.

The pulse control part53as the driving means control part, when it receives from the calculation processing part51control information for correcting the amount of positional variations, outputs control pulse signals to the driver46based on this control information. As a result, the driver46controls the rotation speed on its axis of the stepping motor43, whereby the positional correction of the can barrel101is conducted. Further, pulse signals of the encoder22can be used for generation of control pulse signals, whereby reliability or the like of the control system can be improved.

By providing the above-mentioned rotational positioning controller5, the embossing turret2can conduct all controls by the output pulse from the rotational shaft21(pulse signals from the encoder22). As a result, positioning control can be conducted easily and without fail by inputting numerical values to the operation means (not shown) of the rotational positioning controller5. Therefore, the control operation time required to align the shaping position to the design can be significantly reduced, whereby productivity can be increased.

The can barrel transportation turret15discharges the can barrel101which has been embossed by means of the embossing turret2.

Next, the operation of the embossing device1with the above-mentioned configuration and the embossing method of this embodiment will be explained with reference to the drawings. In the meantime, the embossing method of this embodiment is a method of embossing the can barrel101using the embossing turret2of the above-mentioned embossing device1.

FIG. 6is a schematic view for explaining an embossing method according to one embodiment of the present invention.

InFIG. 6, the can barrel101is supplied to the embossing turret2from the can barrel transfer turret14. That is, at the point (a) shown inFIG. 2, the embossing turret2receives the can barrel101from the can barrel transfer turret14(Step S1). At this time, the machine position detection part52of the rotational positioning controller5has counted the number of pulse signals after inputting Z-phase pulse signals. In the meantime, when the embossing turret2rotates by 360°, the number of pulse signals counted is 4000. Therefore, the number of pulse signals is 500.

Subsequently, the rotational positioning controller5keeps the state in which the control pulse signals are not output to the driver46. That is, the state in which the stepping motor43is stopped (the state in which the rotation on its axis of the can barrel101is stopped) is maintained (Step S2). By keeping the state in which the stepping motor43is stopped, the holding means4can hold the can barrel101, which has been supplied, without fail.

Subsequently, the can barrel101, which is held, revolves to the point (b) shown inFIG. 2, and reaches the position at which the positioning starts (Step S3). At this time, the number of pulse signals counted by the machine position detecting part52is 750.

The positioning start position and the positioning position, which will be mentioned later, are setting parameters, and hence, are set according to the processing speed or the like.

Subsequently, the rotational positioning controller5outputs to the driver46control pulse signals for allowing the can barrel101to rotate on its axis at the same circumference speed as that of the circumference speed of the rotation on its axis of the inner roll31. As a result, the stepping motor43rotates, and the can barrel101, which is held, rotates at the same circumference speed as that of the circumference speed of the rotation on its axis of the inner roll31(Step S4).

Meanwhile, the state in which the can barrel101rotates at the same circumference speed as that of the circumference speed of the rotation on its axis of the inner roll31is called as the “same speed operation”.

Subsequently, the sensor45detects the match mark102on the can barrel101which rotates at the same circumference speed as that of the circumference speed of the rotation on its axis of the inner roll31(that is, which operates at the same speed”) (Step S5), and then outputs the detection signals to the calculation processing part51of the rotational positioning controller5.

The calculation processing part51, upon receipt of the detection signals, obtains the amount of positional variations of the can barrel101based on the positional (machine angle) information of the inner roll31from the machine position detection part52. Then, control information for correcting the amount of positional variations is output to the pulse control part53. Subsequently, upon receipt of control information for correcting the amount of positional variations from the calculation processing part51, the pulse control part53outputs pulse signals for control to the driver46based on this control information. As a result, the driver46controls the speed of the rotation on its axis of the stepping motor43, whereby the correction of the position of the can barrel101is conducted (Step S6).

Here, the calculation processing part51confirms that the match mark102is detected by the sensor45at the point (c) shown inFIG. 2based on the positional (machine angle) information of the inner roll31from the machine position detection part52(normally, the number of pulse signals counted by the machine position detection part52(for example, 910)) at the time of receiving detection signals.

Subsequently, by comparing the point (c) with the positional (machine angle) information of the ideal state which suffers no positional variations (normally, the number of pulse signals counted by the machine position detection part52is 1000, for example), the calculation processing part51can obtain the amount of positional variations. That is, in the case of the ideal state suffering no positional variations, the number of pulse signals counted should be 1000. However, the calculation processing part52receives detection signals when the number of pulse signals counted is 910. Therefore, the amount of positional variations is an amount corresponding to the number of counted signals of 90 in the advance direction.

Subsequently, the calculation processing part51outputs to the pulse control part53control information for correcting the amount of positional variations corresponding to the number of counted signals of 90 in the advance direction, i.e. control signals for slowing the rotation speed of the stepping motor43. As a result, the driver46slows down the revolution speed of the stepping motor43, whereby the positional correction of the can barrel101is conducted. On the contrary, the positional correction of the can barrel101may be conducted by increasing the rotational speed of the stepping motor43.

Then, the can barrel101which rotates on its axis by the stepping motor43revolves to the point (d) shown inFIG. 2, and reaches the positioning position (Step S7). At this time, the number of pulse signals counted by the machine position detection part52is 1500.

As mentioned above, in this embodiment, the rotational positioning controller5conducts positioning from the predetermined positioning start position to the predetermined positioning position while allowing the can barrel101to rotate on its axis, and it does not stop the rotation on its axis of the can barrel101from the predetermined positioning start position to the predetermined positioning position. Therefore, a defect that the positioning accuracy is lowered by suddenly switching from the halt state to the same speed operation can be avoided.

The rotational positioning controller5allows the can barrel101to rotate on its axis at the same circumference speed as that of the circumference speed of the rotation on its axis of the inner roll31. When the sensor45detects the match mark102, the rotational speed of the stepping motor43is controlled, whereby the position of the can barrel101is corrected.

Here, the rotational positioning controller5may obtain the amount of positional variations (error in positioning) based on signals from the sensor45which has detected the mach mark102in the vicinity of the above-mentioned positioning position, thereby to confirm that the amount of positional variations is less than the predetermined threshold value (Step S8). If the amount of positional variations exceeds the predetermined threshold value, the rotational positioning controller5may output emergency signals. In this way, the positioning state before shaping can be confirmed, whereby the reliability of quality can be increased.

Subsequently, the rotational positioning controller5outputs to the driver46control pulse signals for allowing the can barrel101to rotate on its axis at the same circumference speed as that of the circumference speed of the rotation on its axis of the inner roll31. As a result, the stepping motor43rotates, and the can barrel101, which is held, rotates at the same circumference speed as that of the circumference speed of the inner roll31in the state in which the position has been corrected (that is, the state suffering almost no positional variations) (Step S9).

In the meantime, the state in which the can barrel101rotates on its axis at the same circumference speed as that of the circumference speed of the inner roll31in the state which suffers almost no positional variations) is called as the “synchronized operation state”.

In the embossing turret2, between the point (e) and the point (f) shown inFIG. 2, the first processing is conducted (Step S10). Further, the second processing is conducted (Step S11).

Further, the number of pulse signals counted by the machine position detection part52at the point (e) is 1750, and the number of pulse signals counted by the machine position detection part52at the point (f) is 2250.

Here, the embossing turret2of this embodiment can conduct embossing on the can barrel101in the state where the can barrel101is position-corrected (the state which suffers almost no positional variations) and in the state where the can barrel101rotates on its axis at the same circumference speed as that of those of the inner roll31and the outer roll32(“synchronized movement state”).

In this way, generation of molding scars in the embossing can be suppressed. Further, since the embossing positioning accuracy for the design can be improved, appearance can be improved.

Further, as mentioned above, the inner roll31and the outer roll32of this embodiment has two embossing regions which are distant from each other with the non-shaped section35therebetween (that is, the first embossing region33and the second embossing region34), and hence, the embossing turret2can produce double-embossed surface cans which conventionally could not be produced.

Then, the can barrel101, which is held, is allowed to move in a synchronized manner to the point (g) shown inFIG. 2. Subsequently, the rotational positioning controller5keeps the state where the control pulse signals are not output to the driver46. That is, the state where the stepping motor43is halted (the state in which the rotation on its axis of the can barrel101is halted) is maintained (Step S12).

Subsequently, the embossing turret2supplies the embossed can barrel101to the can barrel transportation turret15. That is, the embossing turret2, at the point (h) shown inFIG. 2, transfers the can barrel101to the can barrel transportation turret15(Step S13). At this time, the number of pulse signals counted by the machine detection part52is 3500.

Next, the embossed can10of this embodiment will be explained with reference to the drawings.

FIG. 7is a schematic perspective view of the embossed can according to one embodiment of the present invention.

InFIG. 7, the embossed can10has the can barrel101and a can lid103. This embossed can10is a double-embossed surface can, which is obtained by embossing by using the embossing device1and the embossing method as mentioned above.

That is, on the can barrel101, the first pattern104(“EMBOSS”) is printed, and the first concave portion105(“EMBOSS”) is formed in the state that it is so positioned as to almost conform to the first pattern104. Further, at a position which is distant in the circumferential direction with the non-shaped section therebetween, the second pattern106(“NEWCAN”) is printed, and the second concave portion107(“NEWCAN”) is formed in the state that it is so positioned as to almost conform to the second pattern106.

As mentioned above, according to the embossing device1, the embossing method and the embossed can10according to this embodiment, it is possible to conduct embossing having a non-shaped section and an arbitral number of embossing regions, whereby the quality or productivity can be improved. In particular, the embossed can10which is a double-embossed surface can is able to have an innovative design, whereby additive value can be improved.

Hereinabove, the embossing device, the embossing method and the embossed can of the present invention were explained with reference to preferred embodiments. The embossing device, the embossing method and the embossed can of the present invention are not limited to the above-mentioned embodiments or the like. It is needless to say various modifications are possible within the scope of the present invention.

For example, an explanation was made hereinabove taking the embossing as an example, in particular. However, the present invention can be applied to other processing which requires accurate rotational positioning of the can barrel while allowing the can barrel to rotate on its axis at a predetermined speed.