JP4397472B2 - Printing apparatus and driving method thereof - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention has a plate cylinder on which a printing plate is mounted, an ink supply means for supplying ink to the plate cylinder, and an impression cylinder on which a printing medium is wound, and the impression cylinder and the plate cylinder are driven to rotate. The present invention relates to a printing apparatus that performs printing on a printing medium that passes between them and a driving method thereof.
[0002]
[Prior art]
In a rotary printing apparatus such as a flexographic printing machine that supports multicolor printing, a printing apparatus corresponding to the number of inks used for printing is arranged in-line, and each printing apparatus includes a plate cylinder, an impression cylinder, and an anilox roll. Each rotating body is incorporated. When continuously performing a printing operation on a print medium such as roll paper using such a multi-color rotary printing apparatus, it is necessary to rotationally drive these rotating bodies in accordance with the conveyance speed of the print medium. All printing apparatuses are synchronously driven by a single drive source.
[0003]
A power transmission mechanism of such a conventional flexographic printing machine is schematically shown in FIG. That is, a driving force distributed from a single driving source (not shown) is transmitted to the driving gear 1 of each printing apparatus, and rotational driving of the impression cylinder 2 and the anilox roll 3 is brought about. The driving force is transmitted to the cylinder 4 and the driving force is transmitted from the anilox roll 3 to the pickup roll 5 so that the plate cylinder 4 and the pickup roll 5 are rotationally driven. The ink 7 stored in the ink reservoir 6 is supplied to a printing plate (not shown) mounted on the plate cylinder 4 by the rotation of the pickup roll 5 and the anilox roll 3, and is also wound around the impression cylinder 2 and conveyed. The medium 8 is subjected to predetermined printing while passing between the impression cylinder 2 and the plate cylinder 4.
[0004]
In the rotary printing apparatus having the structure shown in FIG. 4, particularly the flexographic printing machine, the inertia mass of the main body of the plate cylinder 4, the flywheel effect of the printing plate B, or improper adjustment of the impression cylinder 2 and the plate cylinder 4 Due to the printing pressure, a rotational load fluctuation occurs in the plate cylinder 4. For this reason, the rotation of the gear on the side of the plate cylinder 4 is not constant according to the backlash of the gear meshing between the impression cylinder 2 and the plate cylinder 4, and a subtle change in rotational speed occurs in the plate cylinder 4, Along with this, print quality such as gear marks (striped pattern generated at equal intervals along the transport direction of the print medium) and banding (striped pattern randomly generated along the transport direction of the print medium) are impaired. A phenomenon sometimes occurred.
[0005]
In order to eliminate such a problem, conventionally, by adjusting the relative phase of the plate cylinder gear 4G that is attached to the plate cylinder 4 and meshes with the impression cylinder gear 2G, the relative phase of the plate cylinder gear 4G is adjusted. Consideration is made so that the amount of backlash formed between the gear 2G and the gear 2G is appropriate.
[0006]
[Problems to be solved by the invention]
In the conventional printing apparatus shown in FIG. 4, the backlash between the impression cylinder gear 2G and the impression cylinder gear 2G is reduced by adjusting the relative phases of the split cylinder gears 4G. However, it is necessary to adjust the phase of the plate cylinder gear 4G according to the thickness of the printing medium, and this phase adjustment operation is very delicate. If the backlash amount is too large, an adjustment effect can be obtained. If the amount of backlash is too small, printing pressure does not work, and there are adverse effects such as generation of gear eyes.
[0007]
OBJECT OF THE INVENTION
An object of the present invention is to provide a printing apparatus and a driving method thereof that can suppress the occurrence of a phenomenon that impairs printing quality such as gear marks and banding without performing gear backlash adjustment according to the thickness of the printing medium. is there.
[0008]
[Means for Solving the Problems]
According to a first aspect of the present invention, a plate cylinder on which a printing plate is mounted, an ink supply means for supplying ink to the plate cylinder, a printing medium is wound thereon, and the printing cylinder is abutted against the printing cylinder via the printing medium. A printing apparatus having a pressure cylinder in contact with and a drive mechanism that rotationally drives the pressure cylinder and the plate cylinder, wherein the drive mechanism applies a drive source and a drive force from the drive source to the plate cylinder. Plate cylinder driving means for rotationally driving the plate cylinder, and an impression cylinder drive for rotating the impression cylinder by transmitting a driving force applied to the plate cylinder by the plate cylinder driving means. have a means, the plate cylinder drive means includes a drive gear rotatably driven by said drive source, and an idle gear rotatably mounted relative to the impression cylinder so as to mesh with the drive gear, the idle gear Integrally with the plate cylinder to mesh with And a plate cylinder gear being Attach, the impression cylinder drive means, said plate cylinder gear, to have a impression cylinder gear integrally attached to said impression cylinder to engage with the plate cylinder gear It is a feature.
[0009]
According to the present invention, the driving force from the driving source is applied to the plate cylinder having a large inertial mass by the plate cylinder driving means, and the plate cylinder is stably rotated. Next, the driving force applied to the plate cylinder is transmitted to the impression cylinder by the impression cylinder driving means.
[0011]
In the printing apparatus according to the first aspect of the present invention, the plate cylinder gear may include a first gear that meshes only with the idle gear, and a second gear that meshes only with the impression cylinder gear.
[0012]
According to a second aspect of the present invention, there is provided a plate cylinder on which a printing plate is mounted, an ink supply means for supplying ink to the plate cylinder, a pressure cylinder on which a printing medium is wound, and the pressure cylinder and the plate cylinder. A drive mechanism for rotationally driving, the drive mechanism providing a drive source, a plate cylinder driving means for rotating the plate cylinder by applying a driving force from the drive source to the plate cylinder, and the plate Pressure cylinder drive means for rotating the impression cylinder by transmitting a driving force applied to the plate cylinder by the cylinder drive means, and the plate cylinder drive means is driven by the drive source. A drive gear that is rotationally driven, an idle gear that is rotatably attached to the impression cylinder so as to mesh with the drive gear, and a plate cylinder gear that is integrally attached to the plate cylinder so as to mesh with the idle gear; And the impression cylinder driving means includes the plate cylinder gear. When a driving method of a printing device having a impression cylinder gear integrally attached to said impression cylinder to engage with the plate cylinder gear, for rotating the plate cylinder by applying a driving force to the plate cylinder And a step of transmitting a driving force applied to the plate cylinder to the impression cylinder to rotationally drive the impression cylinder.
[0013]
DETAILED DESCRIPTION OF THE INVENTION
An embodiment in which a printing apparatus according to the present invention is applied to a flexographic printing machine will be described in detail with reference to FIGS. 1 to 3. However, the present invention is not limited to such an embodiment, and the claims of this specification are described. The present invention can be applied to other techniques to be included in the concept of the present invention described in the scope of the present invention.
[0014]
In the flexographic printing machine according to the present embodiment, a plurality of printing apparatuses 10 are arranged inline along a conveyance direction of continuous paper (hereinafter referred to as a web) 15 that is a printing medium, one of which The schematic structure of the printing apparatus 10 is schematically shown in FIG. 1, the plate cylinder and the impression cylinder are extracted and enlarged in FIG. 2, and the cross-sectional structure of this part is shown in FIG.
[0015]
That is, in FIG. 3, a side plate (not shown) of the printing apparatus 10 passes through a central portion of a cylindrical plate cylinder 12 to which the printing plate 11 is attached, and a plate cylinder shaft that rotatably supports this through a bearing 13. 14, both ends of the impression cylinder shaft 17 on which the impression cylinder 16 around which the web 15 is wound are integrally formed are rotatably attached via a bearing 18. In addition, as shown in FIG. 1, the printing apparatus 10 has an anilox roll shaft 20 integrally provided with an anilox roll 19 and a pick-up roll whose lower end is immersed in ink 22 stored in an ink reservoir 21. 23, a pick-up roll shaft 24 integrally formed, a web introduction roll shaft 26 integrally provided with a web introduction roll 25 for guiding the web 15 to the impression cylinder 16 side, and a web 15 printed from the impression cylinder 16 A web 15 that is integrally provided with the next printing apparatus 10 or a web discharge roll 27 for completing printing and sending it out of the apparatus is rotatably attached to a discharge roll shaft 28.
[0016]
A main drive shaft 29 connected to a single drive source (not shown) is arranged along the arrangement direction of the printing apparatuses 10 and passes through a gear box 30 provided for each printing apparatus 10 via a bearing 31 so as to be rotatable. It has become a state. The gear box 30 houses a worm 32 that is integrally connected to the main drive shaft 29 and a worm wheel 33 that meshes with the worm 32. The worm wheel 33 is provided at one end. The shaft 34 is rotatably supported by the gear box 30 via a bearing 35 and is also rotatably supported by a side plate of the printing apparatus 10 (not shown).
[0017]
On the other end side of the output shaft 34, a drive gear 36 and a gear 37 that transmits drive to the anilox roll 19 and the pickup roll 23 are attached. Further, a one-way clutch 38 is incorporated between the gear 37 and the output shaft 34, and only a forward rotation of the gear 37 with respect to the output shaft 34 is allowed.
[0018]
The drive gear 36 is engaged with an idle gear 40 rotatably attached to one end portion in the longitudinal direction of the impression cylinder 16 via a bearing 39. The idle gear 40 is fixed to one end portion in the longitudinal direction of the plate cylinder 12. The 1st gear 42 fixed integrally via the volt | bolt 41 (refer FIG. 3) has meshed | engaged. The second gear 43 fixed to the plate cylinder 12 together with the first gear 42 meshes with an impression cylinder gear 45 that is integrally fixed to one end portion in the longitudinal direction of the impression cylinder 16 via a fixing bolt 44.
[0019]
Accordingly, the driving force from the main drive shaft 29 is transmitted from the output shaft 34 to the idle gear 40 via the drive gear 36, and the idle gear 40 is rotatably supported by the bearings 39 with respect to the impression cylinder 16. Therefore, the impression cylinder 16 does not rotate, and the plate cylinder 12 is driven to rotate by the first gear 42 that meshes with the idle gear 40. Then, the impression cylinder 16 is rotationally driven by the impression cylinder gear 45 that meshes with the second gear 43 integral with the plate cylinder 12.
[0020]
On the other hand, due to the web 15 wound around the impression cylinder 16 by a tension device such as a powder brake (not shown) in the tension direction F of the web 15, a braking force in the direction opposite to the rotation direction of the impression cylinder 16 always acts on the impression cylinder 16. In this state, the second gear 43 on the plate cylinder 12 side is meshed with rotating while constantly pressurizing the tooth surface of the impression cylinder gear 45. Therefore, the plate cylinder 12 and the impression cylinder due to the load fluctuations and the like described above. Since no subtle rotation unevenness due to the backlash 16 occurs, the rotation unevenness of the plate cylinder 12 can be prevented in advance. For this reason, it is possible to suppress the occurrence of a phenomenon that impairs printing quality such as gear marks and banding.
[0021]
The above-described drive gear 36, idle gear 40, first gear 42, etc. constitute plate cylinder driving means of the present invention, and the second gear 43, impression cylinder gear 45, etc. constitute impression cylinder driving means of the present invention. ing. In this embodiment, the plate cylinder gear is divided into the first gear 42 and the second gear 43. However, the plate cylinder gear may be constituted by a single gear.
[0022]
The gear 37 meshes with a driven gear 46 provided integrally with the anilox roll shaft 20, and the driven gear 46 further includes a gear 47 provided integrally with the pickup roll shaft 24. I'm engaged.
[0023]
Accordingly, the driving force from the main drive shaft 29 is sequentially transmitted from the output shaft 34 to the driven gear 46 and the gear 47 via the gear 37, and the anilox roll 19 and the pick-up roll 23 are driven to rotate, respectively. The ink 22 is supplied to the printing plate 11 of the plate cylinder 12.
[0024]
On the other hand, an auxiliary drive gear 50 incorporating a one-way clutch 49 is connected to an ink stirring motor 48 that is an auxiliary drive source assembled on a side plate of the printing apparatus 10. Between them, a free gear 52 having a built-in bearing 51 and rotatably mounted is interposed. The ink stirring motor 48 is for driving the main drive shaft 29 while it is stopped to keep the properties of the ink 22 constant, and the forward rotation operation of the auxiliary drive gear 50 is applied to the gear 37 via the free gear 52. The anilox roll 19 and the pick-up roll 23 are driven to rotate.
[0025]
Therefore, when the rotation of the ink stirring motor 48 is stopped, the free gear 52 also rotates with the rotation of the gear 37, but the auxiliary driving gear 50 is also freely rotated by the one-way clutch 49, and the free gear 52 and the auxiliary driving are also rotated. It is considered that the gear 50 is simply idled and does not act as a load on the ink stirring motor 48.
[0026]
【The invention's effect】
According to the present invention, the drive mechanism for rotationally driving the impression cylinder and the plate cylinder includes a drive source, plate cylinder driving means for rotating the plate cylinder by applying a driving force from the drive source to the plate cylinder, the driving force applied to the plate cylinder by the plate cylinder drive means is transmitted to the impression cylinder have a impression cylinder driving means for rotationally driving the impression cylinder, the plate cylinder drive means is driven to rotate by a drive source A drive gear, an idler gear rotatably attached to the impression cylinder so as to mesh with the drive gear, and a plate cylinder gear integrally attached to the plate cylinder so as to mesh with the idle gear. drive means comprises a plate cylinder gear, since the organic and impression cylinder gear which is integrally attached to the impression cylinder to engage with the plate cylinder gear, a driving force from a driving source is first transmitted to the plate cylinder, then Because it is transmitted to the impression cylinder, the plate cylinder and printing plate It is possible to suppress subtle rotation unevenness due to gear backlash caused by load fluctuations that occur during adjustment of the wheel, plate cylinder, etc., and adjust the gear backlash according to the thickness of the print medium as before. Even if it is not performed, it is possible to suppress the occurrence of phenomena that impair the printing quality such as gear marks and banding. In addition, the drive mechanism can be made compact.
[Brief description of the drawings]
FIG. 1 is a perspective view schematically showing a schematic structure of an embodiment in which a drive mechanism of a printing apparatus according to the present invention is applied to a flexographic printing machine.
2 is an enlarged enlarged view of portions of a plate cylinder and an impression cylinder in the embodiment shown in FIG.
3 is a cross-sectional view showing the structure of the plate cylinder and the impression cylinder shown in FIG. 2 in a broken state.
FIG. 4 is a conceptual diagram showing a schematic structure of a conventional flexographic printing machine.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 10 Printing apparatus 11 Plate 12 Plate cylinder 13 Bearing 14 Plate cylinder axis 15 Web (print medium)
16 Impression cylinder 17 Impression cylinder shaft 18 Bearing 19 Anilox roll (ink supply means)
20 Anilox roll shaft 21 Ink reservoir 22 Ink 23 Pickup roll (ink supply means)
24 pickup roll shaft 25 web introduction roll 26 web introduction roll shaft 27 web discharge roll 28 web discharge roll shaft 29 main drive shaft (drive mechanism)
30 Gear box 31 Bearing 32 Worm 33 Worm wheel 34 Output shaft 35 Bearing 36 Drive gear (plate cylinder drive means)
37 gear 38 one-way clutch 39 bearing 40 idle gear (plate cylinder drive means)
41 Fixing bolt 42 First gear (plate cylinder driving means)
43 Second gear (impression cylinder drive means)
44 fixing bolt 45 impression cylinder gear (impression cylinder drive means)
46 driven gear 47 gear 48 ink stirring motor (auxiliary drive source)
49 One-way clutch 50 Auxiliary drive gear 51 Bearing 52 Free gear F Tension direction

Claims (3)

A plate cylinder on which a printing plate is mounted; ink supply means for supplying ink to the plate cylinder; a pressure cylinder on which a printing medium is wound and in contact with the plate cylinder via the printing medium; A printing apparatus having a drive mechanism for rotationally driving the plate cylinder,
The drive mechanism is applied to the plate cylinder by a drive source, plate cylinder driving means for rotating the plate cylinder by applying a driving force from the drive source to the plate cylinder, and the plate cylinder driving means. the driving force is transmitted to the impression cylinder have a impression cylinder drive means for rotating said impression cylinder,
The plate cylinder driving means includes a drive gear that is rotationally driven by the drive source, an idle gear that is rotatably attached to the impression cylinder so as to mesh with the drive gear, and the plate that meshes with the idle gear. A plate cylinder gear integrally attached to the cylinder,
Said impression cylinder drive means, the plate and the body gear, printing apparatus, characterized by chromatic and impression cylinder gear integrally attached to said impression cylinder to engage with the plate cylinder gear. The printing apparatus according to claim 1 , wherein the plate cylinder gear includes a first gear that meshes with only the idle gear, and a second gear that meshes with only the impression cylinder gear. A plate cylinder on which a printing plate is mounted; ink supply means for supplying ink to the plate cylinder ; an impression cylinder on which a printing medium is wound; and a drive mechanism for driving the impression cylinder and the plate cylinder to rotate. The drive mechanism is provided with a drive source, plate cylinder driving means for rotating the plate cylinder by applying a driving force from the drive source to the plate cylinder, and the plate cylinder driving means for applying the plate cylinder to the plate cylinder. An impression cylinder driving means for transmitting the generated driving force to the impression cylinder to rotationally drive the impression cylinder, and the plate cylinder driving means is driven by the drive source, An idler gear rotatably attached to the impression cylinder so as to mesh with the drive gear; and a plate cylinder gear integrally attached to the plate cylinder so as to mesh with the idle gear, the impression cylinder driving means Is meshed with the plate cylinder gear and the plate cylinder gear. Said impression cylinder so as to match a driving method of a printing apparatus and a impression cylinder gear integrally attached to,
Applying a driving force to the plate cylinder to rotationally drive the plate cylinder;
A driving method for a printing apparatus, comprising: a step of transmitting a driving force applied to the plate cylinder to the impression cylinder to rotationally drive the impression cylinder.

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