JPH0710589B2 - Multicolor printer - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial field of application) The present invention relates to multicolor overprinting (ink overprinting) on an outer peripheral surface or a sheet surface of a cylindrical container formed of metal or plastic into a tubular shape. The present invention relates to an improved technique of a multi-color printing device for performing non-multi-color printing, and particularly to a rotary drive system of the multi-color printing device.

(Prior Art) As a multicolor printing method for a cylindrical container, the applicant of the present invention discloses Japanese Patent Laid-Open No.
A method as described in Japanese Patent No. 72958 has been proposed.

In this prior art, in multicolor printing, one transfer roller transfers two or more colors of ink so that the image lines of ink to be overprinted (referred to as halftone dots or thin lines) are not displaced, and at the time of transfer, It was a method of forcibly rotating the cylindrical container side as well.

In other words, by transferring two or more colors of ink with one transfer roller, it is possible to prevent the relative displacement of the ink transfer positions for each color, and forcibly rotate the cylindrical container side during transfer. The purpose of the present invention is to prevent slippage due to collision at the start of contact, which occurs when the cylindrical container is contact-rotated by using the rotation of the transfer roller.

(Problems to be Solved by the Invention) However, in the above-described prior art, a relative rotation error between the rotation of the cylindrical container that is the printing target during printing and the rotation of the transfer roller that transfers the ink. If the rotation of the transfer roller and the rotation of the transfer roller (the roller that transfers ink to the blanket of the transfer roller according to the pattern of the plate) are rotated even if the value is suppressed to a small value, the error is considered to be the cause of streaking. Therefore, if the relative rotation error between the two is not minimized, it is impossible to achieve the purpose of preventing the deviation of image lines and double-color in the multicolor printing.

That is, a normal printing apparatus employs a gear driving unit as a rotation driving unit of a transfer roller or a transfer roller, which suppresses backlash at the time of meshing of each gear to a small amount so that an image doublet (ink transferred to the transfer roller The position is not constant, and therefore the image line printed on the cylindrical container is not displaced, which means that ink is attached to unnecessary portions).

However, when the gears mesh with each other, zero backlash is not possible due to the nature of the gears, so some backlash remains.

As a result, the tooth contact of the gear between the transfer roller and the transfer roller is alternately changed due to the fluctuation of the rotation speed during the printing operation, and the backlash-related image dubbing occurs.

(Means for Solving Problems) The present invention has been made for the purpose of solving the above-mentioned problems, and in order to achieve this object, the present invention uses a blanket for transferring ink to an object to be printed. A transfer roller provided with a transfer roller, a plurality of transfer rollers that transfer ink to the blanket, and a rotation driving unit that drives the transfer roller and the transfer roller to rotate by gears. Of the transfer roller rotating shaft that rotates the transfer roller and the transfer roller rotating shaft that rotates the transfer roller, a brake torque is applied to the rotating shaft that is the driven shaft in the direction opposite to the rotating direction,
A powder brake that can control the torque according to the rotation speed is provided.

(Operation) Therefore, in the multicolor printing apparatus of the present invention, as described above, among the transfer roller rotating shaft for rotating the transfer roller and the transfer roller rotating shaft for rotating the transfer roller, the rotary shaft to be the driven shaft is By providing a powder brake that applies a brake torque in the opposite direction to the rotation direction, even if the rotation speed between the transfer roller and the transfer roller fluctuates, the tooth surfaces of the gears that mesh with each other can always be the same. Therefore, the relative rotation error between the transfer roller and the transfer roller due to the gear backlash can be eliminated.

Further, since the brake torque applying means is a powder brake capable of torque control according to the rotation speed, it is possible to apply the minimum required braking according to the rotation speed of the multicolor printing device at high speed operation. The driving load of the multicolor printing apparatus can be greatly reduced.

(Examples) Hereinafter, examples of the present invention will be described in detail with reference to the drawings. In the description of this embodiment, a multicolor printing device for printing on a can body (an example of a cylindrical container) of a two-piece can used for a container for beverages will be taken as an example.

First, regarding the apparatus of the first embodiment shown in FIGS. 1 to 4,
The configuration and operation will be described.

The multicolor printing apparatus A of the first embodiment is an apparatus of the type in which a mandrel cylinder is driven intermittently, and as shown in FIG. 2, a can body feeding means 1, a mandrel cylinder 2, an upper transfer roller 3, a lower portion, Transfer roller 4, upper transfer roller 5,
6, the lower transfer rollers 7 and 8, the finishing varnish coating roll 9, and the transfer unit 10 are the main components.

The can body supplying means 1 is a molded bottomed cylindrical can body T.
To the mandrel cylinder 2, and sequentially attaches the mandrel 11 to the mandrel 11 of the mandrel cylinder 2, and includes a feeder 12 and an attachment mechanism (not shown) for attaching the mandrel 11 to the mandrel 11.

The mandrel cylinder 2 intermittently rotatably transfers the can body T supported on the circumference in order to print and varnish the outer surface of the can body T. A plurality of mandrels 11 that support the can body T are lined up in the section.

The mandrels 11 are provided in parallel with the cylinder shaft 38 of the mandrel cylinder 2 and projecting at equal intervals on the same circumference.

The upper transfer roller 3 and the lower transfer roller 4 are the can body T.
It is for transferring multicolor ink C to the outer peripheral surface of
Blankets 14 and 15 are wound and fixed on the outer peripheral surfaces of the transfer rollers 3 and 4.

The upper transfer rollers 5 and 6 and the lower transfer rollers 7 and 8 are rollers for providing desired printing on their outer circumferences, and for transferring the predetermined ink C to the blankets 14 and 15 according to the pattern of the plate,
In the embodiment, the upper transfer rollers 5, 6 for transferring the first color ink C1 and the second color ink C2 to the blanket 14 and the lower transfer roller 7, for transferring the third color ink C3 and the fourth color ink C4 to the blanket 15. 8 and.

In addition, the ink C1,
A group of kneading rolls 16, 17, 18, 19 for kneading C2, C3, C4 is provided.

The finish varnish coating roll 9 is a multi-color printed can body T.
This finishing varnish coating roll 9 is provided with a pair of kneading rolls 20 and 21.

The transfer unit 10 is a device that removes the can body T, which has been subjected to multicolor printing and varnishing, from the mandrel 11, attaches it to the transfer chain 24 hung on the sprockets 22 and 23, and transfers it to the next dryer.

Next, the rotation driving means B of the first embodiment device will be described.

As shown in FIG. 1, the rotation driving means B drives the mandrel cylinder 2, the mandrel 11, the transfer rollers 3, 4, and the transfer rollers 5, 6, 7, 8 by using one motor 25 as a drive source. In this rotation driving means B, a mandrel rotating shaft 13 for rotating the mandrel 11 and a transfer roller rotating shaft 26 for rotating the transfer rollers 3 and 4,
Transfer roller rotating shaft 4 for rotating the transfer rollers 5, 6, 7, 8
The first gear 101, the second gear 10 and the second gear 10 are in a driving connection state.
2, third gear 103, fourth gear 104, fifth gear 105, sixth gear 106,
A gear train including the seventh gear 107 is provided.

First, the intermittent rotation drive system of the mandrel cylinder 2 includes a motor 25, a first pulley 27, a first timing belt 28, a second pulley 29, a first intermediate shaft 30, a third pulley 31, a second timing belt 32, and a fourth timing belt 32. The pulley 33, the bevel gears 34 and 35, the rotation input shaft 36, the intermittent rotation device 37, and the cylinder shaft 38.

The cylinder shaft 38 is an unrelated drive system for the second gear 102, the third gear 103, and the ninth gear 109 through bearings.

The rotation drive system of the mandrel 11 includes a motor 25 and a first pulley 2
7, first timing belt 28, second pulley 29, first intermediate shaft 30, eighth gear 108, ninth gear 109, tenth gear 110, second
Intermediate shaft 39, eleventh gear 111, twelfth gear 112, third intermediate shaft 40,
13th gear 113, 3rd gear 103, 2nd gear 102, 1st gear 10
1. The mandrel rotating shaft 13 is used. still,
The eighth gear 108 and the ninth gear 109 are a gear set that meshes with each other, and the second gear 102 and the third gear 103 are connecting members.
41 is formed so as to rotate integrally.

The rotation drive system of the transfer rollers 3 and 4 is derived from the third gear 103, and is composed of a fourth gear 104, a fourth intermediate shaft 43, a fifth gear 105, a sixth gear 106, and a transfer roller rotation shaft 26. It is configured.

The rotary drive system of the transfer rollers 5, 6, 7, 8 is derived from the sixth gear 106, and includes a seventh gear 107 and a transfer roller transfer shaft 4.
It is composed of two.

The transfer roller rotary shaft 42, which is a driven shaft, has a pulley 4
A powder brake 47 (brake torque applying means) is provided via 4, 45 and the belt 46 to apply a brake torque in a direction opposite to the rotation direction of the seventh gear 107 (fourth brake).
In the figure, the meshing tooth surfaces (tooth contact) of the sixth gear 106 and the seventh gear 107 are prevented from changing due to fluctuations in the rotation speed.

The structure of the powder brake 47 used in the embodiment shown in FIG. 3 will be described.

This powder brake 47 is called an electromagnetic powder type (magnetic powder type) that can obtain a torque proportional to the electric current.
A torque proportional to the electric current can be obtained.

The structure is roughly divided into a stationary part and a rotating part. In the stationary part, a yoke 472 having a coil 471 incorporated therein,
A fixed side bracket 473, a fixed rotor boss 474, and a fixed rotor 475 are provided.
It is equipped with a cylinder 477 (connected to the pulley 45). Then, the gap between the fixed rotor 475 and the cylinder 477.
Magnetic powder 479 (so-called powder) is inserted in 478.

The gear ratio of each gear set among the mandrel rotary shaft 13, the transfer roller rotary shaft 26, and the transfer roller rotary shaft 42 is set to an integral multiple gear ratio as follows.

1st gear: 2nd gear = 1: 5 3rd gear: 4th gear = 2: 1 5th gear: 6th gear = 1: 2 6th gear: 7th gear = 2: 1 That is, 2nd gear 102 Is set so that the first gear 101 makes five revolutions and the sixth gear 106 makes one revolution while the mandrel rotating shaft 13 rotated by the first gear 101 makes five revolutions. In addition, the transfer process by the upper transfer roller 3 and the one-pitch rotational transfer process are performed on the can body T.

Next, the operation of the first embodiment will be described.

First, the transfer process to the can body T and the rotational transfer process of the can body T will be described.

(A) Transfer process At the start of transfer, as shown in FIG.
On the other hand, the upper transfer roller 5 transfers the first color ink C1 (transfer section S1) and the upper transfer roller 6 transfers the second color ink C2 (transfer section S2).

In this state, while the can body T makes one rotation (first rotation), the upper transfer roller 3 makes 1/5 rotation to transfer the ink C1 of the first color to the outer peripheral surface of the can body T. T is the next 1
While rotating (second rotation), the upper transfer roller 3 further rotates 1/5 to transfer the second color ink C2 onto the outer peripheral surface of the can body T.

At the time of this transfer, the mandrel cylinder 2 is stationary and only the mandrel 11 is rotated, and the peripheral speeds of the can body T, the upper transfer roller 3, and the upper transfer rollers 5 and 6 are slippery. The peripheral speeds are made equal so that they do not exist.

Also at the position of the lower transfer roller 4, the third color ink C3 and the fourth color ink C4 are transferred in the same manner as described above.

The can body T is 2 1 / while the mandrel cylinder 2 is stationary.
Although it makes two rotations, 1/2 rotation other than the two rotations used for transfer is used as the time for damping mechanical vibration at the moment when the mandrel cylinder 2 that transfers the can body T to the transfer process stops.

(B) Rotational transfer step The can body T, which has finished the transfer, continues to rotate as it is, and while it is further rotated 2 1/2 times, the rotation transfer section P of 1 pitch is used.
Proceed to.

While the can body T is rotationally transferred, the upper transfer roller 3 is
After 1/2 rotation, the upper transfer rollers 5 and 6 rotate once, and the transfer start state shown in FIG. 2 is reached.

In this way, by repeating the transfer process and the rotation transfer process, multicolor printing on the can body T is performed.

Next, the operation of the rotary drive system will be described. First, in the transfer step, the mandrel cylinder 2 supporting the mandrel rotating shaft 13 does not rotate (hereinafter referred to as "revolution"),
Only the mandrel rotating shaft 13 is rotating (hereinafter referred to as rotation).

Therefore, the first gear 101 makes one rotation in the rotation section in which the second gear 102 rotates by 1/5, and the first gear 101 makes one rotation in the rotation section in which the second gear 102 rotates by 1/5. Then, the mandrel rotating shaft 13 is rotated twice for rotation, and transfer is performed during this period.

Then, in the rotation section in which the second gear 102 further rotates by 1/2, the first gear 101 performs the rotation of 2 1/2 rotation and the revolution of the rotation transfer section of 1 pitch.

Further, after the rotary transfer is completed and the mandrel cylinder 2 is stopped, the second gear 102 rotates 1/10 of a rotation section,
The first gear 101 makes one-half rotation, and during this period, mechanical vibration caused by an impact due to the rotation stop of the mandrel cylinder 2 is eliminated.

That is, the transfer step and the rotation transfer step are performed while the first gear 101 rotates 5 times and the second gear 102 rotates 1 time,
The gear position of the gear 102 at the start of transfer is always at the same position.

Incidentally, while the second gear 102 makes one revolution, the third gear 103 makes one revolution, the fourth gear 104 makes two revolutions, and the fifth gear makes the fourth revolution.
Like the gear, it makes two revolutions, the sixth gear makes one revolution, and the seventh gear
Since the 107 rotates twice, the mandrel rotating shaft 13
The gear train between the transfer roller rotary shaft 26 and the transfer roller rotary shaft 42 is always in the same meshing state in the section from the start of transfer to the end of rotational transfer and immediately before the start of the next transfer.

Therefore, the pitch error of each gear is not cumulatively added in the process of drive transmission, and only the pitch error due to the machining accuracy of the gear affects the printing accuracy. Further, in the gear train, a plurality of first gears 101 are provided, and even if the meshing state is the same, only the first gear 101 is different from the gear train. If the processing accuracy of 101 is increased and the uniformity is achieved, the deviation of the image lines can be made extremely small.

As described above, by setting the gear train in the driving connection state and setting the gear ratio of each gear set to an integral multiple ratio, the accumulated pitch error is eliminated, and the deviation of the image line can be prevented. However, the sixth gear 106 and the seventh gear 107 In meshing with the gear, it is impossible to have zero backlash due to the nature of the gear.

Then, the action of the powder brake 47 will be explained.
As shown in the figure, the powder brake 47 applies a brake torque to the transfer roller rotation shaft 42 in the direction opposite to the rotation direction (direction of arrow D).

Therefore, fluctuations in the rotation speed between the transfer rollers 3 and 4 and the transfer rollers 5, 6, 7, and 8 (the driving torque of the gear train drivingly connected at the time of starting or stopping the intermittent rotation driving of the mandrel cylinder 2 is However, the tooth surfaces of the gears meshing with each other can always be the same, and the transfer rollers 3, 4 due to the backlash of both gears 106, 107
It is possible to eliminate the relative rotation error between the transfer rollers 5, 6, 7, 8 and the transfer rollers 5, and thereby prevent the image lines from being doubled.

Incidentally, a test example conducted by the present inventor will be described below.

(Test specifications) Gear type; Helical gear module; 3 tooth width; 45mm Backlash; 0.05 to 0.08mm Gear rotation speed; 300rpm Brake torque; 4.0kg ・ m (MAX) (Test result) As a result of the above specifications, gear rotation Even at several 300 rpm, beautiful multi-color printing with no deviation of image lines and no dubbing was obtained.

Next, a second embodiment shown in FIG. 5 will be described.

The multicolor printing apparatus A'of the second embodiment is an apparatus of a type in which a mandrel cylinder is continuously driven to rotate, so that the rotation driving locus M of the can body T can be transferred while simultaneously rotating and revolving. At the positions of the transfer rollers 3 and 4,
Part of the locus is corrected so as to follow the surfaces of the transfer rollers 3 and 4.

Although illustration of the drive means is omitted, it goes without saying that a brake torque applying means such as a powder brake can be applied to the transfer roller rotating shaft as in the first embodiment.

Although the embodiment of the present invention has been described in detail above with reference to the drawings, the specific configuration is not limited to this embodiment, and the present invention can be applied even if there is a design change or the like within a range not departing from the gist of the present invention. included.

For example, in the embodiment, the multicolor printing apparatus having a cylindrical container is illustrated, but the present invention can be applied to a multicolor printing apparatus such as a sheet printing apparatus.

(Effects of the Invention) As described above, in the multicolor printing apparatus of the present invention, among the transfer roller rotating shaft that rotates the transfer roller and the transfer roller rotating shaft that rotates the transfer roller, the driven shaft is Relative rotation error between the transfer roller and the transfer roller due to gear backlash is provided because the brake torque is applied to the rotating shaft in the direction opposite to the rotating direction and the powder brake that can control the torque according to the rotating speed is provided. The effect of being able to eliminate is obtained. Due to this effect, the position of the ink that is repeatedly transferred from the transfer roller to the transfer roller becomes the same position, so that the double dot of the image line is eliminated, and it is possible to perform multicolor printing of a precise pattern at high printing speed. it can.

In addition, since a powder brake that can control the torque according to the rotation speed is provided as the brake torque applying means, it is possible to apply the minimum required braking according to the rotation speed of the printing device. The effect that the driving load can be greatly reduced is obtained.

[Brief description of drawings]

FIG. 1 is a plan view showing a driving means of a multicolor printing apparatus according to a first embodiment of the present invention, FIG. 2 is an overall side view showing the apparatus of the first embodiment, and FIG. 3 is used for the apparatus of the first embodiment. FIG. 4 is a half sectional view showing the powder brake, and FIG. 4 is a sixth view of the first embodiment device.
FIG. 5 is a view showing a meshed state of the gear and the seventh gear, FIG.
It is explanatory drawing which shows an Example apparatus. B ... Rotation driving means T ... Can body (printed material) 3,4 ... Transfer roller 5,6,7,8 ... Transfer roller 14 ... Blanket 26 ... Transfer roller rotation shaft 42 ... Transfer roller rotation Axis 47 …… Powder brake (brake torque applying means) 106 …… Sixth gear 107 …… Seventh gear

 ─────────────────────────────────────────────────── ─── Continuation of the front page (56) References: 58-92047 (JP, U): 60-101262 (JP, U): 59-58456 (JP, U): 59-58456 69897 (JP, U) Actual development Sho 58-95946 (JP, U)

Claims (1)

[Claims] 1. A transfer roller provided with a blanket for transferring ink to an object to be printed, a plurality of transfer rollers for transferring ink to the blanket, and a rotation driving means for rotationally driving the transfer roller and the transfer roller by gears. In a multi-color printing apparatus including: a transfer roller rotating shaft that rotates the transfer roller and a transfer roller rotating shaft that rotates the transfer roller, a rotating shaft that is a driven shaft is rotated in a direction opposite to a rotating direction. A multicolor printing device characterized by being provided with a powder brake capable of applying a brake torque and controlling the torque according to a rotation speed.