JP3678067B2 - Gravure engraving equipment - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a gravure engraving apparatus that engraves a gravure printing cell on a gravure cylinder.
[0002]
[Prior art]
In the field of soft packaging used for vinyl packaging of various products, gravure printing using a gravure cylinder is used. An apparatus for forming a gravure printing cell for this gravure cylinder is a gravure engraving apparatus. For example, a mechanical engraving gravure engraving apparatus for engraving a cylinder surface by vibrating a diamond engraving needle relative to the cylinder is known. is there. In this mechanical engraving type gravure engraving apparatus, the volume of the cell is determined by changing the vibration amount of the engraving needle in accordance with image data. The amount of ink to be filled is determined by the change in the volume of the cell, and the shade at the time of gravure printing is reproduced by the change in the amount of ink.
[0003]
The diamond tool used for the engraving needle has a tip angle of, for example, about 120 degrees, and the engraved cross section also has a substantially triangular shape due to the tool shape. Therefore, in order to engrave a cell having a large cell volume, that is, a deep cell in order to increase the printing density of the vinyl packaging, the cell width must be increased.
[0004]
[Problems to be solved by the invention]
When engraving with high printing density as described above, the cell width is increased in the conventional gravure engraving apparatus, so the number of engraving lines is reduced and high-definition printing cannot be performed. In order to prevent this, it is conceivable to use a sharp diamond tool with a small tip angle that can be deeply engraved. In this case, however, the engraving needle is easily broken, which is not practical. It was.
[0005]
In order to solve this problem, a method of enlarging the engraved cell by etching can be considered. That is, when engraving is performed on a gravure cylinder coated with a protective layer for etching, the protective layer on the cell is removed with the formation of the cell. By etching this, only the engraved cell portion can be etched deeply.
[0006]
An object of the present invention is to provide a gravure engraving apparatus that can easily perform engraving work even when an etching process is used in combination after engraving.
[0007]
[Means for Solving the Problems]
The invention according to claim 1 is a gravure engraving apparatus that includes an engraving head that processes a surface of a gravure cylinder, and engraves a gravure printing cell on the gravure cylinder according to desired image data, A first engraving mode for engraving normal gravure cylinders under predetermined engraving conditions, and a gravure cylinder with a protective layer for etching in a later process to perform engraving by correcting the engraving conditions. And the second engraving mode is characterized in that the engraving conditions are corrected based on the etching conditions in the etching step .
[0008]
According to a second aspect of the present invention, in the first aspect of the invention, in the second engraving mode, the engraving condition is corrected based on at least one of a type or a thickness of the protective layer .
[0009]
According to a third aspect of the invention, in the invention of the first or second aspect, the engraving condition is corrected by correcting the image data .
[0010]
According to a fourth aspect of the present invention, in the invention according to any one of the first to third aspects, the engraving condition is corrected by changing a distance between the gravure cylinder and the engraving head .
[0011]
According to a fifth aspect of the present invention, in the first aspect of the invention, the deburring means for removing the burrs generated by engraving in contact with the peripheral surface of the gravure cylinder, and deburring in the second engraving mode And prohibiting means for prohibiting use of the means .
[0013]
A sixth aspect of the present invention is the first aspect of the present invention, wherein the boundary surface between the gravure cylinder and the protective layer is provided on the protective layer so as to be movable along the axial direction of the cylinder. Detecting means for detecting the position of the engraving head, and distance adjusting means for adjusting the distance of the engraving head to the gravure cylinder based on the detection result of the detecting means.
[0014]
DETAILED DESCRIPTION OF THE INVENTION
First, a gravure plate making process using a gravure engraving process and an etching process which are the premise of the present invention will be described with reference to FIG. In addition, FIG. 8 is a figure which shows the cross section in the cylinder surface vicinity in each process.
[0015]
First, FIG. 8A is a cross-sectional view of the cylinder surface showing a state in which a protective layer b for etching treatment is further formed on a gravure cylinder having a general copper plating layer a on the surface. Here, the protective layer b is formed by applying and coating a resist material that is not corroded by the etching solution. For example, a rosin-based, acrylic resin-based, or cellulose-based resist material can be used. This resist material has a considerably lower hardness than the copper plating. It should be noted that other materials such as a hot-melt adhesive can be used as long as they are not corroded by the etching solution and can be easily engraved.
[0016]
When the gravure cylinder with the protective layer b shown in FIG. 8A is mechanically engraved, for example, the engraving is performed with a cross section as shown in FIG. 8B, and protection is provided from the engraved cell portion. Layer b is removed. The volume of the cell c by this engraving is almost the same as that of the conventional gravure engraving when the presence of the protective layer b can be ignored. In other words, the protective layer b made of the resist material is much lower in hardness than the copper plating layer, and therefore the influence on the entrance of the engraving needle is almost negligible.
[0017]
Then, when the engraved gravure cylinder shown in FIG. 8B is immersed in an etching solution and etched, as shown in FIG. 8C, a portion where the protective layer b is removed, that is, a copper plating layer a is formed. Etching is performed from the opened openings, so that cells d having a large cell volume are formed. Thereafter, the resist is stripped and removed as shown in FIG. 8D, and if necessary, a chromium plating layer f is formed as shown in FIG. 8E, and the gravure plate making is completed. In this way, if the etching process is used in combination, the cell d having a larger volume than the cell c formed by the normal engraving process can be formed.
[0018]
Hereinafter, in this embodiment, a gravure engraving apparatus that can use two types of gravure cylinders, a normal gravure cylinder and a gravure cylinder with a protective layer, will be described. 1 is a front view showing an example of a gravure printing apparatus according to the present invention, FIG. 2 is a top view of the apparatus, and FIG. 3 is a side sectional view of the apparatus.
[0019]
In the figure, the gravure engraving apparatus has a base 1, a spindle stock 2 and a core pusher 3 for holding the gravure cylinder GC rotatably, and an engraving mechanism 4 for engraving the gravure cylinder GC.
[0020]
The head stock 2 is fixed on the base 1 and rotatably supports a support portion 5 having a truncated cone shape at the tip so as to fit into the mounting hole of the gravure cylinder GC. The support portion 5 is rotationally driven by a drive mechanism 6 including a motor and a belt.
[0021]
On the other hand, a support portion 7 having a conical tip is rotatably supported also on the core support 3 so as to be fitted into the mounting hole of the gravure cylinder GC. Further, the core pusher 3 is movably mounted on a rail 8 provided on the base 1 so as to be close to or away from the headstock 2 and is driven by a drive mechanism including a motor 9 and a ball screw 10. It is configured to move in a direction approaching or separating from the headstock 2.
[0022]
In this gravure engraving apparatus, the gravure cylinder GC is sandwiched between the support part 5 on the headstock 2 side and the support part 7 on the core pusher base 3 side as shown by a two-dot chain line in FIG. It is rotationally driven according to the rotation of the support part 5.
[0023]
The engraving mechanism 4 includes a sub-scanning table 11 movable along the axial direction of the gravure cylinder GC, a sub-table 12 installed on the sub-scanning table 11, and an engraving head installed on the sub-table 12. 13 and burr removing means 14 for removing burr after engraving.
[0024]
The sub-scanning table 11 is a flat table-like member that can move in a direction parallel to the axis of the gravure cylinder GC along the rail 15 provided on the base 1, and is moved and driven by a motor 16 and a ball screw 17. The A rail 18 is provided on the sub-scanning table 11 in a direction in which the gravure cylinder GC is in contact with and separated from the gravure cylinder GC, and the sub-table 12 is movably mounted on the rail 18. Then, the sub-table 12 is moved by the motor 19 and the ball screw 20 in a direction in which the sub-table 12 comes in contact with and separates from the cylinder surface.
[0025]
Next, the engraving head 13 and the burr removing means 14 installed on the sub-table 12 will be described with reference to FIGS. 4 is a side view of the engraving head 13, and FIG. 5 is a front view thereof.
[0026]
In the figure, the engraving head 13 comprises a support base 21 fixed on the sub-table 12 and a head body 23 supported on the support base 21 so as to be rotatable about a shaft 22. The head main body 21 is a housing frame having a storage space inside, and a vibration mechanism 25 (shown in FIG. 6) for vibrating the engraving needle 24 and a distance between the engraving needle 24 and the cylinder surface. And a capacitance type sensor 26 for detecting the. Here, the engraving needle 24 is arranged so as to protrude from the head main body 21 toward the cylinder surface, and the electrostatic capacitance sensor 26 can detect the distance to the cylinder surface at a position close to the engraving needle 24. Has been placed. Instead of the capacitive sensor 26, another non-contact distance sensor may be used.
[0027]
On the other hand, the bottom of the head body 23 is permanently placed on the piezo drive means 27 fixed on the support base 21. The piezo driving means 27 is an actuator in which a plurality of piezo elements are stacked, and can apply a minute amount of expansion and contraction in the vertical direction in FIGS. 4 and 5 by applying a predetermined voltage. In this configuration, the head main body 23 can be rotated around the shaft 22 by expansion and contraction of the piezo driving means 27, so that the engraving needle 24 can be brought into and out of contact with the gravure cylinder GC in real time. . Instead of the piezo driving means 27, an electromagnetic actuator or a combination of a high-speed motor and a ball screw may be used.
[0028]
As shown in FIG. 5, the burr removing means 14 includes an arm member 28 arranged in a gate shape so as to surround a part of the side surface and the upper surface of the head main body 23, and a position above the engraving needle 24 of the arm member 28. And a cutter member 29 provided on the surface. In the present embodiment, the cutter member 29 is made of a diamond tool similar to the engraving needle 24, and is located downstream of the engraving needle 24 when viewed from the rotation direction of the gravure cylinder GC.
[0029]
As shown in FIG. 4, a short arm portion 28 a is formed at the lower end of the arm member 28 so as to have a substantially L-shaped structure when viewed from the side. On the other hand, it is supported so as to be rotatable about the shaft 30. A spring 31 is fitted between the short arm portion 28a of the arm member 28 and the sub table 12, and urges the cutter member 29 so as to contact the cylinder surface.
[0030]
On the other hand, an electromagnetic solenoid 32 is provided above the short arm portion 28a. When a predetermined voltage is applied to the electromagnetic solenoid 32, the short arm portion 28a is pushed down to bring the cutter member 29 from the cylinder surface. It can be selectively saved.
[0031]
In FIG. 4, reference numeral 33 denotes a manual adjustment micrometer for moving the engraving needle 24 forward or backward with respect to the cylinder surface and finely adjusts the position of the vibration mechanism 25.
[0032]
Next, the structure of the vibration mechanism 25 of the engraving needle 24 will be described with reference to FIG. Here, FIG. 6 is a perspective view of a general vibration mechanism 25. In the figure, the vibration mechanism 25 includes a torsion shaft 36 having torsional elasticity and one end fixed to a pedestal 35, and a stylus 37 fixed to the free end side of the torsion shaft 36 and having an engraving needle 24 at one end. The rotor part 38 made of a substantially rhomboid magnetic material fixed to the middle part of the torsion shaft, the winding 39 wound around the rotor part 38, and the rotor part 38 are sandwiched in close proximity from both sides. It comprises a stator portion 40 made of a magnetic material and a permanent magnet 41 that applies a magnetic force to the stator portion 40.
[0033]
In this vibration mechanism, when an engraving signal based on image data is applied to the winding 39, a magnetic flux is generated in the rotor portion 38, so that the rotor portion 38 acts on the magnetic field of the stator portion 40 and rotates. The engraving needle 24 is driven by the rotational force of the rotor portion 38 via the torsion shaft 36 and the stylus 37. The engraving signal has a sine wave-shaped carry signal superimposed with a density signal representing the density of the image, and the engraving needle 24 vibrates by a vibration amount corresponding to the density signal at a period corresponding to the amplitude of the carry signal. It is configured as follows.
[0034]
In the gravure engraving apparatus according to the present embodiment, first, the gravure cylinder GC is sandwiched between the spindle stock 2 and the core pusher 3. Then, the sub-table 12 is positioned with respect to the cylinder surface according to the cylinder diameter determined in advance. Then, the gravure cylinder GC is rotated and the sub-scanning table 11 is moved in the axial direction of the gravure cylinder. Accordingly, an engraving signal based on the image data is given to the engraving head 13 and the engraving needle 24 is vibrated to perform engraving. As a result, an image is formed in a spiral shape on the surface of the gravure cylinder GC. The sub-table 12 may be moved intermittently to form an image in a circular shape on the cylinder surface.
[0035]
In the case of a general gravure cylinder GC engraving, the burr generated by the engraving can be removed by the burr removing means 14. On the other hand, when engraving the gravure cylinder GC with the protective layer, the burr removing means 14 is retracted from the cylinder surface by the electromagnetic solenoid 32 so as not to damage the protective layer.
[0036]
On the other hand, in a general gravure cylinder GC, a material such as an iron core that is copper-plated is used and is produced with high precision. However, the diameter is, for example, due to variations in plating thickness or distortion of the substrate itself. It has an error of about several tens of μm. Therefore, in a general gravure engraving apparatus, the engraving head 13 is provided with a contact member (shoe) for keeping the distance between the cylinder surface and the engraving head 13 constant.
[0037]
However, since the gravure engraving apparatus of the present embodiment may use a gravure cylinder GC with a protective layer, the contact type shoe may damage the protective layer in the same manner as the burr removing means 14. Accordingly, in the present embodiment, the distance to the cylinder surface is detected in a non-contact manner by the capacitive sensor 26, and the piezo driving means 27 is driven in accordance with the detection result so that the distance between the engraving needle 24 and the cylinder surface is reached. The distance is adjusted to be constant.
[0038]
On the other hand, even in the gravure cylinder GC with the protective layer, the thickness of the protective layer b may not be uniform. Thus, when the thickness of the protective layer b is not uniform, the opening of the cell to be etched is not constant unless the distance between the engraving head 13 and the surface of the copper plating layer a is constant. Therefore, in the present embodiment, the position of the boundary surface e between the copper plating layer a and the protective layer b in the gravure cylinder shown in FIG. 8A is detected. In other words, since the capacitance sensor 26 can detect the thickness of the protective layer that is a non-dielectric material, the position of the boundary surface e can be grasped even if the protective layer b is present. Therefore, in this embodiment, when the gravure cylinder GC with the protective layer is used, the position of the engraving head is controlled by detecting the boundary surface e.
[0039]
Next, the operation of the gravure engraving apparatus in the present embodiment will be described using the flowchart of FIG. In the figure, first, in step S1, initial setting of each part of the apparatus, return to origin, and the like are performed. In the next step S2, the engraving mode is selected by the operator. That is, when the normal gravure cylinder GC is used, the first engraving mode is selected and the process proceeds to step S3. In this first engraving mode, normal engraving processing is performed, but description thereof will be omitted.
[0040]
On the other hand, when the gravure cylinder GC with the protective layer is used, the second engraving mode is selected in step S2 and the process proceeds to step S4 and subsequent steps. The second engraving mode is a mode for engraving a gravure cylinder with a protective layer.
[0041]
The second engraving mode has the following two features compared to the first engraving mode. The first is the setting change of the gravure engraving apparatus in step S4. Specifically, as described above, the burr removing means 14 is retracted and the control position of the engraving head by the capacitive sensor 26 is changed. is there. That is, when the second engraving mode is selected, the electromagnetic solenoid 32 is actuated to bring the cutter member 29 into a state in which contact with the cylinder surface is prohibited. On the other hand, the engraving head is positioned according to the boundary surface e.
[0042]
The other is correction of image data in step S5. In this step S5, the image data is corrected in advance according to the etching conditions of the subsequent process, and the volume of the formed cell is controlled to a desired value. For example, even if the cell is engraved under the same engraving condition, the volume of the cell after etching varies if the etching process conditions (for example, the etching time, the type of etchant, the activity, etc.) are different. Accordingly, the image data is corrected in advance in accordance with an etching processing apparatus scheduled to be used in a later process.
[0043]
In the apparatus according to the present embodiment, an increase rate of the cell volume for each etching condition is obtained in advance as a test, and the image data is corrected according to the increase rate. For example, consider the following as a simple model case. This model case is for ease of understanding, and the numerical values are not actual. In this example, assuming that the cell volume increase rate by etching is 50%, a cell having a cell volume of 60 at the time of engraving becomes a cell volume of 90 after etching. Here, when the operator sets the density increase due to the etching to a somewhat lower limit and, for example, wants to hold a cell with a cell volume of 50 to about 80, the image data is stored in advance so that the cell volume at the time of engraving becomes 40. It is corrected.
[0044]
The above example is a simplified model case. Actually, the cell volume increase ratio changes depending on the opening area of the cell, and the cell volume increase ratio of a cell having a small opening is smaller than that of a large cell. Therefore, the correction is preferably performed for each cell size. By correcting the image data in advance according to the etching conditions as described above, the dimension of the cell after etching can be set to a desired value.
[0045]
On the other hand, depending on the etching conditions, a so-called side etching phenomenon may occur in which etching proceeds in the cell width direction. This is a case where the copper plating portion under the protective layer is eroded by etching and the cell width becomes larger than the opening of the cell formed in the copper plating layer. In such a case, the width of the gap between the cells, that is, a so-called generally banked portion is unduly reduced, which may adversely affect printing. Therefore, in the correction of the image data in step S5, the image data may be corrected in advance so as to reduce the cell width at the time of engraving in consideration of such an increase in cell width due to side etching.
[0046]
In the present embodiment, as shown in step S5, the image data is corrected in advance, and the dimension of the cell after etching can be set to a desired value. This is much easier than changing the conditions on the etching processing apparatus to vary the progress of etching.
[0047]
Returning to FIG. 7, in step S6, engraving is performed. Since this engraving operation itself is the same as the normal engraving operation in step S3, the following description is omitted. In step S7, it is determined whether there is a next engraving work. If there is a next engraving work, the process returns to step S1, and if there is no next engraving work, all the work is completed.
[0048]
[Other embodiments]
[0049]
(1) There may be a means for observing the cylinder surface, and a means for automatically determining whether the gravure cylinder is a normal gravure cylinder or a gravure cylinder with a protective layer. For example, this can be achieved by providing means for detecting the color and reflectance of the cylinder surface and comparing it with a reference value obtained in advance.
[0050]
(2) Although the hardness and thickness of the protective layer are ignored in the above embodiment, engraving conditions may be corrected according to the type and thickness of the protective layer. For example, test engraving is performed in advance for each type and thickness of the protective layer, and changes in cell dimensions due to the presence of the protective layer are measured in advance. Based on this result, the optimum distance of the engraving needle to the cylinder surface and the correction amount of the image data may be set in advance according to the type and thickness of the protective layer.
[0051]
(3) Other engraving conditions may be changed between the first engraving mode and the second engraving mode. For example, in the second engraving mode, the cell volume can be increased by etching in the subsequent process. Therefore, the number of engraving lines may be set higher than in the first engraving mode, or an engraving needle having a wide tip angle may be used. Good.
[0052]
(4) In the above embodiment, the engraving work is performed after correcting all the image data. However, the engraving work is performed while correcting the necessary image data or engraving signal during the engraving work. May be.
[0053]
(5) In the above embodiment, the cell size after etching is set to a desired value by correcting the image data, but this is achieved by changing the distance between the engraving needle and the cylinder surface. You may do it.
[0054]
(6) Although the mechanical gravure engraving apparatus is used in the above-described embodiment, a laser gravure engraving apparatus that forms a cell by drilling with beam energy can also be used.
[0055]
【The invention's effect】
In the invention described in claim 1, a normal gravure cylinder and a gravure cylinder with a protective layer can be selected and used. When engraving a gravure cylinder with a protective layer, an etching process in a later step The volume of the engraved cell can be increased. Moreover, since the engraving conditions are corrected according to the etching conditions, the dimension of the cell after etching can be set to a desired value .
[0056]
In the second aspect of the invention, the engraving conditions are corrected according to the type and thickness of the protective layer, so that more accurate engraving can be performed .
[0057]
According to the third aspect of the present invention, the dimension of the cell after etching can be set to a desired value by correcting the image data .
[0058]
In the fourth aspect of the invention, the dimension of the cell after etching can be set to a desired value by changing the distance between the engraving head and the cylinder surface .
[0059]
In the invention according to claim 5, since the burr removing means does not work during engraving of the gravure cylinder with the protective layer, it is possible to prevent the protective layer from being damaged .
[0061]
In the invention described in claim 6 , since the boundary between the protective layer and the cylinder surface (copper plating surface) is detected and the distance between the engraving head and the gravure cylinder is adjusted, the protective layer Even if the thickness is not uniform, accurate engraving can be performed.
[Brief description of the drawings]
FIG. 1 is a front view of a gravure engraving apparatus according to an embodiment of the present invention.
FIG. 2 is a top view of the gravure engraving apparatus.
FIG. 3 is a sectional side view of the gravure engraving apparatus.
FIG. 4 is a side view of an engraving head of the gravure engraving apparatus.
FIG. 5 is a front view of the engraving head.
FIG. 6 is a perspective view showing a vibration mechanism of an engraving needle.
FIG. 7 is a flowchart showing an operation procedure of the gravure engraving apparatus.
FIG. 8 is an explanatory diagram showing the state of a cell when an etching process is performed after the engraving process.
DESCRIPTION OF SYMBOLS 1 Base 2 Main spindle 3 Core pushing stand 4 Engraving mechanism 13 Engraving head 14 Deburring means 24 Engraving needle 25 Vibration mechanism 26 Capacitance type sensor 27 Piezo drive means 28 Arm member 29 Cutter member 32 Electromagnetic solenoid a Copper plating layer b Protective layer c Cell after engraving d Cell after etching e Interface f f Chrome plating layer GC Gravure cylinder

Claims (6)

A gravure engraving apparatus comprising an engraving head for processing the surface of a gravure cylinder and engraving a cell for gravure printing on the gravure cylinder according to desired image data,
A first engraving mode for engraving normal gravure cylinders under predetermined engraving conditions, and a gravure cylinder with a protective layer for etching in a later process to correct the engraving conditions and perform engraving. 2 engraving modes ,
In the second engraving mode, the engraving condition is corrected based on an etching condition in an etching process . 2. The gravure engraving apparatus according to claim 1, wherein in the second engraving mode, the engraving condition is corrected based on at least one of a type or a thickness of the protective layer. The correction of the engraving conditions, gravure engraver according to claim 1 or 2 was performed by the correction of the image data.   The gravure engraving apparatus according to any one of claims 1 to 3, wherein the engraving condition is corrected by changing a distance between the gravure cylinder and the engraving head. Deburring means for removing burrs generated by engraving by contacting the peripheral surface of the gravure cylinder;
The gravure engraving apparatus according to claim 1, further comprising a prohibiting unit that prohibits the use of the burr removing unit in the second engraving mode. Detection means provided so as to be movable along the axial direction of the cylinder, and detecting a position of an interface between the gravure cylinder and the protective layer from above the protective layer;
The gravure engraving apparatus according to claim 1, further comprising a distance adjusting unit that adjusts a distance of the engraving head from the gravure cylinder based on a detection result of the detecting unit.

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