Patent Application
20080163773
The present invention is directed to inking units of a printing press and to methods for operating an inking unit. The inking unit is configured as a single train roller inking unit with two distribution cylinders that are arranged in series in the roller train. One distribution cylinder is close to or proximate the forme cylinder while the other is more distant or remote from the forme cylinder.
In WO 03/039872 A1, an inking unit for a printing press is described. Two distribution cylinders of that inking unit are mechanically coupled to each other and are rotationally actuated via a shared first drive motor. These two distribution cylinders are placed in oscillating motion together via a second drive motor that is different from the first drive motor.
DE 44 30 693 A1 describes a drive for an inking unit. The distribution cylinders of the inking unit are either coupled to one another and are actuated via a shared, angular position-controlled drive motor, or are rotationally actuated separately, each via its own drive motor. In one embodiment, under actuation conditions, in which the requirements for synchronization, such as, for example, of the web tension elements or of the distribution cylinders, are not too high, speed- or torque-controlled electric motors can also be used.
DE 100 44 860 A1 describes an inking unit which is comprised of four distribution cylinders. Three of the distribution cylinders are rotationally actuated by a positive coupling with a rotational drive. One distribution cylinder is rotationally actuated solely via friction.
DE 101 57 243 A1 describes a drive for a distribution cylinder. A rotative motion of the cylinder is generated via a first, preferably speed-controlled electric motor. An oscillating motion of the distribution cylinder is generated via a second, preferably angle-controlled motor by the use of a difference in the rotational speeds.
DE 102 19 903 A1 describes a drive for a distribution cylinder, in which both rotative and translational motion can be generated by the provision of a special arrangement of coil windings. By acting unevenly upon two windings, which are arranged axially side by side, uneven torque is generated, thereby resulting in movement in an axial direction. The axial and angular positions are then reported back to the control system via a position sensor.
The object of the present invention is to provide inking units for a printing press, which inking units are improved in terms of their cost and/or their ink transfer; and to provide methods for operating these inking units.
The object is attained in accordance with the present invention.
The benefits to be achieved by the present invention consist especially in that the inking unit allows ink motion to be improved by enabling a nearly uninterrupted rolling of the rollers which are engaged against one another in the area of the roller train that is near the forme cylinder. At the same time, decreased wear and tear and/or reduced energy consumption and/or reduced expenditures on control assemblies can be achieved.
It is advantageous, in accordance with the present invention, that the distribution cylinder which is positioned close to the forme cylinder is not drive connected to a drive motor, and is instead rotationally actuated solely via frictional contact with interacting rollers. This close distribution cylinder thus executes no rotational motion that is forced via a mechanical drive connection with a drive motor. The distribution cylinder that is distant from the forme cylinder receives rotary drive energy via a mechanical coupling with a drive motor, in addition to the frictional actuation via the rollers.
In a further advantageous improvement of the subject invention, the inking unit and/or the roller train of the inking unit can be configured as a modular component with its own side frame. The drive for the inking unit can also be configured as a transmission module with a separably connected drive motor, and can be separably connected to the inking unit frame outside of the printing press.
Preferred embodiments of the present invention are illustrated in the accompanying drawings and will be described in greater detail below.
The drawings show in:
a) a first position of the inking unit drive; and in
b a second position of the inking unit drive.
A printing press, such as, for example, a web-fed rotary printing press, and especially a multicolor web-fed rotary printing press, has, as depicted schematically in
The forme and transfer cylinders 07; 06 are preferably each configured with, for example, a cylinder width of at least two, and for example with a width of four or even six, vertical print pages which are arranged side by side in newspaper format, and especially in broadsheet format. In one embodiment, at least the forme cylinders 07 can, for example, each have a circumference that corresponds essentially to two print pages arranged in tandem in newspaper format. In another embodiment, the circumference of at least the forme cylinder can correspond to a single print page of this type.
The forme cylinder 07 is preferably rotationally actuated via an angular position-controlled drive motor 15, as may be seen in
The inking unit 08, which is characterized, for example, as a single-train roller inking unit 08 or as a “long inking unit”, has multiple rollers 11; 12; 13; 14; 16. The inking unit 08 which is depicted in
The soft surfaces of the application rollers and/or of the transfer rollers 11; 13, referred to in short as the soft rollers 11; 13, are resilient in a radial direction. For example they may be constructed with a rubber layer, which is indicated in
When the rollers 11; 12; 13; 14 of the inking unit 08 are engaged against one another, the hard surfaces of the respective first and second distribution cylinders 12.1; 12.2 dip into the soft surfaces of the respective interacting soft rollers 11; 13 to a greater or lesser degree, based upon engagement pressure between the rollers and/or the adjustment path of these rollers. This engagement causes the circumferential ratios of interacting rollers 11; 12; 13; 14 to change, depending upon the roller impression depth, as the several rollers roll against one another.
If, for example, one of the multiple interacting rollers in the roller inking unit 08 is forced into rotational actuation based upon a preset speed, such as, for example, via a drive motor or a corresponding mechanical drive connection to another actuated component, then an adjacent soft roller that is actuated solely by virtue of friction with the former roller will rotate at a different speed based upon the impression depth of the first roller. However, if this soft roller were to also be actuated by its own drive motor, or additionally were to be driven via friction resulting at a second nip point, and by another speed-controlled roller, then, in a first case, this could result in a difference between the motor-driven preset speed of the drive roller and the speed generated by friction of the second roller, and in a second case, it could result in a difference between the two speeds which are both generated by friction. This will result in roller slippage at the nip points and/or will result in unnecessary strain on the drive motor or motors.
In the area of the inking unit 08 near the forme cylinder, and especially in the area of the application of ink by the application rollers 11 onto the printing forme, with the solution to be described below, and in accordance with the present invention, a slip-free rolling or “true rolling” and a slip-free or true rolling inking are achieved.
The first distribution cylinder 12.1, which is situated near the forme cylinder, is rotationally actuated solely via friction with the adjacent application roller 11 and the first transfer roller 13. It has no additional mechanical drive connection to the drive for the printing group cylinders 06; 07, or to another inking unit roller that is forced into rotational actuation, or to its own separate drive motor for executing its rotational actuation. In this manner, the first distribution cylinder 12.1 is rotationally actuated predominantly via the, in this example, two, or optionally also one or three forme application rollers 11 that are actuated via friction with the forme cylinder 07, and thus essentially has the circumferential speed of the forme cylinder 07, regardless of the impressions at the nip points that lie between them. The second distribution cylinder 12.2 that is distant from the forme cylinder, as indicated in
Preferably, both of the distribution cylinders 12.1; 12.2 have an oscillation or a friction gearing 19 that is symbolized in
In an embodiment of the present invention that is mechanically less complicated, the first distribution cylinder 12.1 that is near the forme cylinder has its own oscillation gearing 19 that converts only its rotational motion into an oscillating motion. This oscillation gearing 19 can advantageously be configured as a cam mechanism, in which, for example, an axial stop that is fixed to the frame interacts with a curved, peripheral groove which is secured to the roller. Alternatively, an axial stop, that is fixed to the roller, interacts in a peripheral groove of a cam disk, which is fixed to the frame. In principle, this oscillation or friction gearing or transmission 19, that converts the cylinder rotation to an oscillating axial linear stroke, can be implemented as another suitable gearing transmission 19, such as, for example, as a worm gear or as a crank mechanism that is equipped with an eccentric.
As depicted in
In
The drive motor 18 acts on a drive sprocket 26, via a coupling 23 by way of a shaft 24. The drive sprocket 26, in turn, interacts with a spur gear 27 that is non-rotatably connected to the second distribution cylinder 12.2. This connection can be made, for example, on a journal 29 of the second distribution cylinder 12.2, via an axle section 28, which axle section 28 supports the spur gear 27. A corresponding axle section 28 of the first distribution cylinder 12.1 has no such spur gear 27 and has no drive connection to the drive motor 18. The drive connections between the drive sprocket 26 and the spur gear 27 of the second distribution cylinder 12.2 are preferably evenly toothed and are configured with a tooth engagement that has sufficient overlap to accommodate for each position of the oscillating motion of the second distribution cylinder 12.2. The two distribution cylinders 12.1; 12.2 are mounted in a side frame 31 in bearings 32, such as, for example, in radial bearings 32, which radial bearings 32 also enable axial movement. There is no rotational drive connection between the drive motor 18 and the first distribution cylinder 12.1. The drive sprocket 26 and the spur gear 27, which is arranged on the axle section 28, together form a transmission, and specifically form a speed-reducing transmission, for rotational actuation, which transmission forms a unit that can be enclosed and/or can be preassembled and which has its own housing 30. At its output side, the unit can be coupled with the journals 29.
The oscillation drive 22 is also actuated by the drive motor 18, such as, for example, via a worm gear 33, 34. In this configuration, actuation of the oscillation drive 22 is accomplished via a worm 33 which is arranged out of the shaft 24 or via a section of the shaft 24 which is configured as a worm 33 on a worm gear 34, and which is non-rotatably connected to a shaft 36 that extends perpendicular to the rotational axis of the distribution cylinder 12.1; 12.2. In each case, a drive 37 is arranged on the end surface of the shaft 36, and is also arranged eccentrically to the rotational axis of the shaft 36, which driver 37 is, in turn, connected, rigid with respect to pressure and tension in the axial direction of the distribution cylinders 12.1; 12.2, to the journals 29 of the distribution cylinders 12.1; 12.2. Such a connection may be, for example, via a crank mechanism, such as, for example, via a lever 38 that is rotatably mounted on the driver 37, and a joint 39. In
As is shown in
With reference to
The transmission unit, which is preferably preassembled as a module, such as from an axial gearing and/or oscillation gearing 22, can be completely pre-assembled as a sub-unit for the inking units 08 that are implemented, for example, as a module. In an advantageous embodiment, the transmission unit can be pre-mounted on the side frame 31 of the inking unit module before being installed in the printing unit 01. Modularity also allows the installation/replacement/exchange of the transmission unit that is implemented as a module if the inking unit module has already been installed in the machine.
Because the first distribution cylinder 12.1 that is near the forme cylinder has no forced rotational actuation, the rollers 11, 13 roll against one another largely without slip, at least in the area of the inking unit that is near the forme cylinder.
In principle, the drive motor 18, that rotationally actuates the second distribution cylinder 12.2, can be configured as an electric motor which can be controlled or regulated with respect to its output and/or with respect to its torque and/or also with respect to its speed. In the latter case, if the drive motor 18 is being operated in a speed-regulated/controlled manner, even in print-on, then, in the area of the inking unit 08 that is distant from the forme cylinder, the aforementioned problems involving the different effective roller circumferences can still occur.
With respect to the previously discussed set of problems involving a preset speed competing with the friction gearing, however, the drive motor 18 is advantageously configured such that it can be controlled or can be regulated in terms of its output and/or its torque, at least during the printing operation in print-on position. In contrast to speed or to angular position control, in this case a torque is preset as the command variable or as the target value, rather than a speed that is to be maintained or a preset angular position. However, this preset variable does not correspond to a solely short-term and constantly changing preset variable within a speed or an angular position control loop in the ms range for the purpose of regulating a preset angular position or a preset speed. Instead, it is a fixed preset variable, which is to be maintained over an extended period of time, in other words over a period of time lasting multiple roller revolutions, without overlapping a speed or an angular position control loop. For example, during a printing operation in the print-on position, up to an optional monitoring for a maximum speed, in order to protect the motor 18, the drive motor 18 is operated, at least within certain limits, at a free speed, i.e. without a preset speed. “Free speed” in this case means that the drive motor can be operated either without any specified speed, or in any case with a monitoring of an upper and/or lower speed limit.
Preferably, the drive motor 18 is regulated or is controlled in terms of its torque, since the preset torque is independent of the speed, which is essentially determined by the friction gearing.
This operation that is controlled/regulated in terms of its output and/or its torque can, in principle, be implemented by the use of a drive motor 18 which is configured as a synchronous motor 18 or as an asynchronous motor 18. If the drive motor 18 is configured as a synchronous motor 18, regulation, in this embodiment, is focused on maintaining a current/torque constant in order to maintain a preset torque, or in the case of control, the constant is firmly preset. If the drive motor 18 is configured as an asynchronous motor 18, phase relationships between the reactive current and active current are also taken into account via calculation.
Various embodiments of the present invention are presented in what follows.
In a first embodiment of the present invention, which is the simplest in terms of expenditure, the drive motor 18 is configured as an asynchronous motor 18, for which only one frequency, for example in print-off for the inking unit 08, and/or one electrical drive output or one torque, in print-on for the inking unit 08 is preset in an allocated drive control unit 46. When the inking unit 08 is in print-off, or in other words, when the application rollers 11 are out of rolling contact with the forme cylinder 07, the inking unit 08 can be placed in a circumferential speed that is suitable for the print-on position through use of the second distribution cylinder 12.2, using a preset frequency, at which speed the circumferential speeds of the forme cylinder 07 and of the application rollers 11 differ by less than 10%, and especially differ by less than 5%. This limit advantageously also applies as a condition for the print-on position in the embodiments which are set forth below. A preset frequency or output or torque, which is suitable for this, can be determined empirically and/or through a calculation which has been performed beforehand, and can be stored either in the drive control itself, in a machine control, or in a data processor of a control center. The preset value can preferably be changed by the operator in a procedure which advantageously also applies to the preset values listed below.
In the print-on position, or in other words when the application rollers 11 are in rolling contact with the forme cylinder 07, and all the inking rollers are engaged against one another, the rollers 11; 12.1; 13; 12.2; 13; 14 are rotationally actuated, in part, by the forme cylinder 07 via the friction gearing which is now produced between the rollers 11; 12.1; 13; 12.2; 13; 14. The drive motor 18 thus need only apply the decreased power that continues to decrease in the friction gearing with its increasing distance from the forme cylinder 07. In other words, the drive motor 18 can be operated at a low drive torque or at a low drive power, which contributes only to holding the rear area of the inking unit 08 at the circumferential speed that is predetermined essentially by the frictional contact. In a first variation, this driving output can be held constant for all production rates, or speeds of the forme cylinder 07 and can correspond either to that preset value for starting up in print-off, or can represent its own constant value for production. In a second variation, for different production rates, and optionally also for starting up in print-off, different preset values, with respect to frequency and/or driving output, can be predetermined and stored. Depending upon the production rate, or the production speed, the preset value for the drive motor 18 can then vary.
In a second preferred embodiment, in addition to the drive control unit 46 and the asynchronous motor 18 of the first embodiment, the drive also has a rotational speed reset feature. In the operational phase, in which the inking unit operation is in print-off, the drive motor 18 can essentially be synchronized with the speed of the assigned forme cylinder 07 or of the printing group cylinder 06; 07. In this second embodiment, a sensor 47, such as, for example, an angular sensor 47, which is configured to detect actual speed, can be arranged on a rotating component, such as, for example, on a rotor of the drive motor 18, the shaft 24, the shaft 28, or the journal 29, which is non-rotatably connected to the distribution cylinder 12.2. In
A third embodiment of the present invention has a synchronous motor 18 in place of the asynchronous motor 18 of the second preferred embodiment. A rotational speed resetting and a relevant synchronization and regulation in the print-off phase are accomplished, according to the second embodiment, for example, in the drive control unit 46.
In a fourth preferred embodiment, a drive motor 18, and particularly a synchronous motor 18, is provided, which drive motor 18 is optionally speed-controlled in a first mode, for the inking unit 08 in print-off and in a second mode can be regulated with respect to torque, for the inking unit 08 in print-on. For speed control, the drive control unit 46 and the drive motor 18 preferably again have an inner control circuit, which, in a manner similar to that of the second embodiment, comprises a reset for an external angular sensor 47 or for a sensor system which is internal to the motor. When synchronous motors 18 are used, several such synchronous motors 18 in a printing unit 01 can be assigned a shared frequency transformer or converter.
A further improvement on the fourth preferred embodiment of the present invention, that is advantageous in terms of versatility, but which is more complicated, involves configuring the drive motor 18 as a servomotor 18 that can optionally be position and torque-controlled. In other words motor 18 can be a three-phase alternating current synchronous motor with a device that allows the relevant rotational position or the formed rotational angle to be determined based upon an initial position of the rotor. The reporting of the rotational position can be accomplished via an angular sensor, such as, for example, a potentiometer, a resolver, an incremental position transducer or an encoder. In this embodiment, each drive motor 18 is equipped with its own frequency transformer or converter.
In the case of a drive motor 18 that is implemented in the manner of the second, third, or especially the fourth embodiment, and which can be at least speed-synchronized, and especially can be speed-controlled, the drive control unit 46 is advantageously in signal connection with a so-called virtual control axis, in which an electronically generated control axis position F rotates. The rotating control axis position F serves in synchronization, with respect to the correct angular position and its temporal change, angular velocity F, in mechanically independent drive motors of units that are assigned to the same web, and especially drive motors of individual printing group cylinders or groups of printing group cylinders, and/or the drive of a folding unit. In the operating mode, in which the inking unit 08 is to be actuated in synchronization with respect to the speed of the forme cylinder 07, a signal connection with the virtual control axis can thus supply the information on machine rate or speed to the drive control unit 46.
Preferably, in the actuation of the second distribution cylinder 12.2 via the drive motor 18, the process is thus that when the inking unit 08 is running, but is in the print-off position, wherein the application rollers 11 are disengaged, the drive motor 18 is actuated in a speed-controlled or regulated manner. When the machine is running, as soon as the inking unit 08, and specifically the application rollers 11 have been adjusted to the print-on position, the speed regulation or control is intentionally discontinued. In other words, a speed is no longer maintained. Instead, the drive motor 18 is operated in the remainder of the process with respect to torque, such as, for example, at a predetermined electrical output, and/or with respect to a torque that can be adjusted at the controller of a drive motor 18, especially an asynchronous motor 18. The torque to be adjusted, or the output to be adjusted, is, for example, chosen to be lower than a threshold torque that would lead to a first rotation, under slip of the actuated second distribution cylinder 12.2 with an interacting roller 13 that is engaged but which is fixed with respect to rotation.
The load characteristics of a drive motor 18, which is configured as an asynchronous motor 18, comply with the behavior which is intended for this purpose in such a manner that with an increasing load, a frequency decrease, with a simultaneous increase in drive torque, takes place. If, for example, a great deal of drive energy, and thus of circumferential speed originating from the forme cylinder 07, is lost in the friction gearing between the forme cylinder 07 and the second distribution cylinder 12.2, so that the load on the drive motor 18 increases, then the increased torque is provided at a reduced frequency. Conversely, a low level of torque is transmitted by the drive motor 18, so that it runs quasi unloaded when sufficient energy is transmitted via the friction gearing to the distribution cylinder 12.2.
While preferred embodiments of the inking systems of a printing press and a method for operating an inking system, in accordance with the present invention have been set forth fully and completely hereinabove, it will be apparent to one of skill in the art that changes in, for example, the structure of the printing cylinders, the type of web being printed, and the like could be made without departing from the true spirit and scope of the present invention which is accordingly to be limited only by the appended claims.
| Number | Date | Country | Kind |
|---|---|---|---|
| 102005014060.2 | Mar 2005 | DE | national |
This application is the U.S. National Phase, under 35 USC 371, of PCT/EP2006/050961, filed Feb. 15, 2006; published as WO 2006/100158 A2 and A3 on Sep. 28, 2006, and claiming priority to DE 10 2004 014 060.2, filed Mar. 23, 2005, the disclosures of which are expressly incorporated herein by reference.
| Filing Document | Filing Date | Country | Kind | 371c Date |
|---|---|---|---|---|
| PCT/EP06/50961 | 2/15/2006 | WO | 00 | 8/1/2007 |
