FR2765146A1 - METHOD AND DEVICE FOR CONTROLLING INK DELIVERY IN PRINTING MACHINES - Google Patents

Abstract

The present invention relates to a method and a device for controlling the ink supply for the ink taker unit of a printing machine, the device comprising an ink roller extending over the width of format of the machine and of the dosing elements cooperating with the ink roller, the dosing elements for stopping the supply of ink outside the printing format being in active connection with an inking remote control having a format memory. - According to the invention, the inking remote control (4) has a format control (4.2) in active connection with the format memory (4.1), thanks to which at least one metering element (2) can be ordered outside the print format (DF; FG) to generate an ink layer thickness (s1 - sn) at least temporarily different from zero on the ink roller (1).

Description

The present invention relates to a method for controlling

  the ink supply for the taker's inking unit of a printing machine

  pressure, in particular a sheetfed offset printing machine, in which, in adjacent metering areas, on an ink roller, layer thicknesses of the intended value are adjusted accordingly

  according to the ink requirement of the plate and, in the dosing areas ex-

  no later than the printing format, no ink is supplied. The pre-

  sente invention also relates to a device for the implementation

of the above process.

  In sheetfed offset printing machines, the ink is

  glued by metering elements on an ink roller in the form of layers of ink. From the ink roller, a transport takes place

  ink by means of a pick-up roller making a gradual movement

  dular back and forth between the ink roller and an inking unit roller produced in particular as the first distributor roller, by means of other inking unit rollers, on the plate. On the

  ink roller, it is regulated by several metering elements in particular

  bind remotely adjustable, each time, an ink film corresponding to the ink need in the respective dosing area. The thickness of this ink film (layer thickness) depends on the ink requirement of the plate in the

respective printing area.

  EP-0 353 625 discloses a control panel for a printing machine, in particular a printing machine.

  rotary offset, thanks to which the individual metering elements telecom-

  Mandables are adjustable in the ink units. A pair of control elements is associated with each individual dosing area, so that in the chosen ink unit and the ink dosing area

  desired, the dosing element can be moved to generate the thick-

  ink layer desired at this location on the ink roller.

  In this control panel, it is further provided that actuators

  double pairs of key pairs cause the zone to stop

  respective wise (of the corresponding dosing element) with regard to settings in whole or in percentage or that, by double actuation of two pairs of keys in different dosing zones, the dosing zones each time intermediate can be associated with the print format. Outside the print format, that is to say in the dosing areas in which no ink is taken from the plate, the dosing elements are set completely against the roller. inkwell, that is to say that there is no ink supply via the inkwell roller. Thanks to the positioning

  continuous ink metering elements against the ink roller, the

  cre is scraped there permanently, i.e. the ink roller

  turns, in these ink metering areas, "empty".

  Because the ink metering elements in the dosing areas

  wise outside the print format are completely applied against the ink roller, this results in two drawbacks. On the one hand, in a first phase, the pick roller simply comes into contact with the ink metering zones inside the format zone, which

  contact taking place at the start of the contact phase in the areas of

  ink in which, due to the high ink requirement, the elements

  ink metering elements are adjusted as far as possible from the ink roller,

  that is to say that the greatest thickness of ink layer prevails there.

  With this separation process depending on the thickness of the layer

  ink between the ink roller and the pick roller or the pre-roller

  neur and the distributor roller, there is moreover also between these

  generally central pressure, that is,

  corresponding flexions for the pairs of rollers lying

  actually in contact with each other.

  Furthermore, it must be considered disadvantageous that,

  outside the print format, due to the dosing elements

  fully applied against the ink roller, the ink roller and the pick-up roller, as well as the pick-up roller that does not transfer ink

  in these areas and the distributor roller have a reciprocal action

  than one with the other without ink. Precisely when using ele-

  ink metering elements, which allow the ink to be scraped very well,

  turning "unladen" results in increased wear on the wheels.

  corresponding waters or their surfaces.

  Document DE-4 038 574 discloses a process for

  order the application of the printing ink to obtain prints

  polychrome elements in conjunction with a special ink control strip

  ciale. In this case an ink control strip is used to

  which, for specific inks, measurement fields are pre-

  seen only in each second dosing area. For a propor-

  particularly small print surface area, in areas

  which the plate has no proportion of print surface

  and in which the ink control strip for the ink remains

  pective also does not present any measurement field, the element of

  ink can be fully applied against the ink roller.

  Determining the proportion of the printing surface for the zo-

  The respective dosing is carried out by means of a plate sweep

that (preset).

  Document DE-4 429 481 discloses a process for improving

  printing ink in a printing machine, in which,

  when printing with plates with a small proportion of over-

  printing side, to improve the transient behavior between two

  stationary inking states in at least one metering zone which

  responds to a printing area with a proportion of surface area

  non-zero pressure, no ink supply occurs.

  For a small proportion of printing surface uniformly distributed on the plate, it can be provided that the ink metering elements do not

  open only in each second dosing area so

  meet the ink requirement and are closed per-

  in the intermediate dosing zones.

  With the two methods indicated above to order

  When the ink is supplied, an optimal adaptation of the dosage of

  created and the ink flow thus caused to the requirements of a plate. In re-

  However, indications such as adjusting the ink metering elements outside the printing area, i.e. on both sides of the format limits, cannot be removed from this state. of

the technique.

  Consequently, the aim of the present invention is to develop a method and a device, for implementing this method,

  to control the supply of ink to a printing machine,

  yielded as defined above, so that a significant improvement in ink transfer between an ink roller, a pick roller and a

  inking roller arranged downstream of it is possible and that an increase

  the wear of these rollers is avoided in the dosing zones

  outside the print format.

  To this end, the method for controlling the supply of ink for the taker's inking unit of a printing machine, as indicated above, is remarkable, according to the invention, in that, for generating an ink film on the pick-up roller in the area outside the printing format on the ink roller in at least one metering area, at least temporarily, an ink layer thickness, different from

zero, is set.

  Preferably, outside the print format, in zo-

  nes of determined dosing, an ink layer thickness different from zero is generated and, in each case at least one zone of

  intermediate dosage, no printing ink supply takes place.

  Advantageously, in the zone of the limits of the printing format

  sion, in a predefined number of dosing zones, the ink supply

  completely stopped.

  In addition, the adjustment, carried out in the metering areas outside

  of the print format, ink supply can be maintained

  unchanged during printing, or changed over time during printing

  pressure, or determined from the ink requirement of the plate.

  The present invention also relates to a device for controlling the ink supply for the taker inking unit of a printing machine, in particular an offset printing machine with

  sheets, comprising an ink roller extending over the width of the

  machine mat and metering elements cooperating with the roller

  ink, the metering elements to stop the ink supply to the outside

  of the printing format being in active connection with a telecom-

  inking command having a format memory, device for implementing the above method, remarkable, according to the invention, in that the inking remote control has a format command in active connection with the format memory, thanks to which at least one

  metering element can be ordered outside the print format

  at least temporarily an ink layer thickness

  non-zero on the ink roller.

  Advantageously, by format control, outside the print format, an ink layer thickness other than zero can be adjusted by means of determined metering elements and, in each case at least one zone of intermediate dosage, the elements of

  dosing can be adjusted completely against the inkwell roller.

  Preferably, by format command, in the area of limits

  print format, a number of which can be predefined

  can be adjusted completely against the ink roller.

  In addition, the portions of the printing surface of the plate can

  can be brought to the format control and from there the adjustment of the elements

  Dosage items can be determined outside of the format limits.

  According to the invention, it is provided that, on both sides of the limits of the printing format, the ink metering elements are adjusted in determined zones at a setting value other than zero relative to the ink roller, that is to say, in at least one dosing zone on each side of the format limits, it is generated, by means of a

  ink metering element, on the ink roller, at least temporarily

  rement, an ink layer thickness other than zero. In addition, it can be expected that this non-zero ink layer thickness

  is generated permanently, that is to say during all the function

  printing. Before the start of printing operation

  metering areas outside the format to be printed are determined and, in selected metering areas, the elements of

  ink dosages are set to expected values.

  Thanks to the corresponding adjustment of the ink metering elements and thus of the ink film generated on the ink roller (layer thickness) in the area outside the print format, it occurs, in these areas, an ink flow from the ink roller, via the pick-up roller, to the first distribution roller, thanks to the transverse ink flow (in particular the effect of the first distribution roller after the pick-up roller) , The ink in the intermediate dosing zones (ink dosing elements completely applied against the ink roller) being brought back towards the ink roller. The value of the layer thickness in the ink metering areas outside the print format, which is created by the ink metering elements which are not completely applied against the ink roller, is also chosen so that the ink transferred from the ink roller to the pick roller is transported to the first dispensing roller and, on the metering areas having metering elements completely

  applied against the ink roller, again transported to the

  yell. The adjustment values to be provided for this also depend on the geometry of the inking unit and, in particular, on the diameters of the roller.

  ink, the take-up roller and the first distributor roll.

  The thicknesses of the ink layers to be generated on the ink roller are also chosen so that, also outside the printing format, an ink film is created on the pick roller and the printing roller. inking (distributor roller) arranged downstream thereof and the ink supplied to the inking unit in this zone, in the zones in which the metering elements are closed, is brought back towards the inkwell

  or the ink roller, that is to say, in total, it does not occur

  no ink flow extending to the engraved cylinder or to the application rollers cooperating with the engraved cylinder. Thus, it is avoided that the

  rollers in the upper part of the inking unit (pick roller -

  first distributor roller) turn without ink and that, in the part

  of the inking unit (application rollers), create ac-

ink accumulations.

  In a development of the invention, it is intended that, in the transition zone between the format (that is to say the printing zones on

  the photo) and the area outside the format, a determined number of elements

  ink metering remains fixedly applied against the ink roller, that is to say that, in these ink metering areas, there is produced, permanently, no ink supply. Depending on the subject to be printed, there may also be provided one, two or three ink metering zones, as ink-free corridor, on the ink roller, an ink-free zone may also be found, for example. example, in print format. Thanks to this ink-free corridor, it is avoided that, by the transverse flow of ink (lateral distribution), ink from the metering areas of the printing format having a portion of printing surface (metering elements open) reaches beyond the limits of the format and, there, drives on the inking rollers, the engraved cylinder

  and / or the blanket cylinder, ink accumulations.

  According to one embodiment of the invention, in the dosing zones outside the printing format, the dosing elements are adjusted, in each second dosing zone, to a determined value different from zero. This setting of the ink metering elements in the

  dispensing areas outside the print format are kept for

  during all the printing operation. According to another form of reaction

  As a preferred embodiment of the invention, it can be provided that, in the metering areas outside the print format, the settings to be provided are modified from time to time. Outside the print format, for example, a periodic exchange takes place between the dosing areas

  ink with zero ink application and ink dosing areas

created with ink supply.

  The inking remote control developed according to the invention includes

  carries, next to a format memory, a format command by which, by means of the inking remote control, in the zones

  outside the print format, the previous settings

  are explained. In particular, preset data due to a plate scan can be brought to the inking remote control, to the format memory and to the format control

  or due to data from previous steps properly prepared

  laying, from which the dosing zones or the dosing elements

  outside the print format and must have a setting other than zero and the corresponding setting values

  can be determined. In addition, thanks to the pre-setting data

  we can also determine the number of dosing zones for

  ink-free corridor, i.e. how many dosing areas must

  Can be considered as a transition from the print format to the area outside the format for zero ink application. It can also be provided that, by means of the format command, due to the size of the printing format and the portion of the printing surface in the printing format (ink consumption of the plate), the elements ink dosing outside the print format are set in every second or simply in every third or fourth dosing area to an expected dosing value other than zero or that such settings / setting recommendations are derived from data

  a plate scan or previous step data.

  The figures in the accompanying drawing will make it clear how

The invention can be realized.

  Figure 1 shows the device according to the invention for setting

implements the process of the invention.

  FIG. 2 illustrates the principle of supplying ink according to the invention.

tion.

  FIG. 1 shows an ink roller 1 and elements of do-

  ink ink 2 cooperating with the ink roller 1, each of which

  is available via a 3 remote adjustment drive

  controllable. The ink roller 1 spans the width of the machine format, and therefore a number of metering elements 2 are associated, next to each other, with ink roller 1 (figure 2). The individual adjustment drives 3 of the dosing elements

  ink 2 are in active connection with an inking remote control 4

  read as a programmable calculator, from which, after corresponding choice of inking units, ink metering elements 2 can be moved relative to the ink roller 1 by a keyboard

not shown.

  The inking remote control 4 has a memory of format 4.1, to which, by means of input means not shown of the inking remote control 4, in the individual inking units, the

  format limits can be set as the correct dosage areas

  corresponding to the format limits (numbering of the dosing zones

  Zil; Zi2). Thanks to the memory of format 4.1, in connection with a pro-

  gram rotating in the inking remote control 4, the elements of

  sage 2 in the respective ink unit outside the print format

  sion are blocked against global settings (for example a percentage setting, a parallel setting), that is to say that, for such an order, only the dosing elements in the format are

  ordered accordingly.

  The inking remote control 4 has, next to the format memory 4.1, another format command 4.2 reading the format limits of the individual inking units, which, next to the format limits (format memory 4.1), can receive the number of zones of

  dosage for corridors F without ink and the name

  bre of dosing areas outside the print format having an ink layer thickness other than zero and which sets these values or

  data, as described below, via remote

  ink command 4. Thanks to the 4.2 format command, it can be

  also generated, for the metering elements 2, outside the lines

  moths of FG format, setting values memorized or that can be

  determined (plate scan) from subject S of the radiograph DF and this

  these can be implemented.

  In Figure 2, we see the ink roller 1, as well as the elements

  metering elements 2 cooperating with the ink roller 1 in the individual zones Z1, Z2, ..., Zn. Above the ink roller 1 with the individual dosing zones Z1, Z2, ..., Zn, the maximum format MF is shown. It is printed, in this example (this inking unit), with a DF plate which, in its width (format width), is smaller

  than the maximum format MF. On the DF picture, the subject determining the sample

  ink ink is designated by S. The DF image shows the limits of

  FG format, which coincide with the corresponding zones Zil, Zi2.

  These zone numbers can be entered in format memory

  4.1 via the inking remote control 4.

  Within F format limits, i.e. between areas

  Zil, Zi2, it is adjusted by the metering elements 2 on the feed roller

  shout 1, an ink profile (sl-sn layer thickness distribution) of

  way corresponding to the ink need of the subject S on the plate DF. Formerly

  within FG format limits, by format 4.2 command, the elements

  metering elements 2 in the intended areas are alternately set to a predetermined value and, in the intermediate areas, completely

  against the ink roller 1. In the areas that coincide with the limits

  tes of format FG of the radiograph DF, the dosing elements 2 were total-

  applied against the ink roller 1. As already mentioned

  qué previously, the number of zones in the zone of limits of form-

  mat FG to generate ink-free corridors F can be bound

  short chosen, that is to say, it can be expected that in one, two or

  three metering zones, metering elements 2 are completely displaced

  against the FG format limits.

Claims (10)

  1. Method for controlling the ink supply for the feed unit   takeover of a printing machine, in particular a machine   sheetfed offset printing, in which in suitable dosing areas   adjacent, on an ink roller, layer thicknesses of expected value are adjusted in accordance with the ink requirement of the plate and, in the metering areas outside the printing format, no ink supply does not take place,   characterized in that, to generate an ink film on the pre-roll   neur in the area outside the printing format on the ink roller in at least one dosing area, at least temporarily,   an ink layer thickness, other than zero, is set.   2. Method according to claim 1,   characterized in that, outside the print format, in zo-   nes of determined dosing, an ink layer thickness different from zero is generated and, in each case at least one zone of   intermediate dosage, no printing ink supply takes place.   3. Method according to claim 1 or 2, characterized in that, in the zone of the limits of the printing format,   in a predefined number of dosing zones, the ink supply pressure is completely stopped.   4. Method according to one of the preceding claims,   characterized in that the adjustment, carried out in the dosing zones at   outside the print format, the ink supply is kept in changed during printing.   5. Method according to one of claims 1 to 3,   characterized in that the setting, made in the metering areas outside the print format, of the ink supply is changed in time during printing.   6. Method according to one of the preceding claims,   characterized in that the adjustment, made in the metering areas outside the printing format, of the ink supply is determined at   from the ink requirement of the plate.   7. Device for controlling the supply of ink for the taker inking unit of a printing machine, in particular a sheet-fed offset printing machine, comprising an ink roller extending   across the format width of the machine and co-operating metering elements   using the ink roller, the metering elements to stop the   born of ink outside the print format being in active connection with an inking remote control having a format memory,   for implementing the method according to one of the claims of pro- yielded previous,   characterized in that the inking remote control (4) has a   format command (4.2) in active connection with the format memory (4.1), by means of which at least one metering element (2) can be controlled   outside the print format (DF; FG) to create a thick-   ink layer seur (sl - sn) at least temporarily different from zero on the ink roller (1).   8. Device according to claim 7, characterized in that, by the format control (4.2), outside the printing format (DF; FG), an ink layer thickness (sl - sn)   non-zero can be set using metering elements   completed (2) and, in each case at least one inter-   medium (Zl - Zn), the metering elements (2) can be adjusted completely   against the ink roller (1).   9. Device according to claim 7 or 8, characterized in that, by the format control (4.2), in the area of   print format (DF) limits (FG), a number can be predefined   finished dosing elements (2) can be adjusted completely against ink roller (1).   10. Device according to claim 7, 8 or 9, characterized in that the portions of the printing surface of the plate (DF) can be brought to the format control (4.2) and, from there, the adjustment of the elements of dosage (2) can be determined outside format limits (FG).