Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B41—PRINTING; LINING MACHINES; TYPEWRITERS; STAMPS
  • B41F—PRINTING MACHINES OR PRESSES
  • B41F7/00—Rotary lithographic machines
  • B41F7/20—Details
  • B41F7/24—Damping devices
  • B41F7/30—Damping devices using spraying elements

Definitions

• the invention relates to methods for setting a spray dampening system according to the preamble of claim 1, 2, 40 or 41.
• a dampening unit for an offset printing machine in which a dampening solution is atomized in a pulse-like manner as a function of the speed of a forme cylinder with a selectable pulse duration and is applied intermittently to a surface of a roller of the dampening unit by means of nozzles.
• the German design document DE 1 761 736 supplements DE 1 611 313 in such a way that a pulse duration and pulse repetition frequency can be set, the pulse duration being longer at a low printing speed of the forme cylinder and shorter at a higher printing speed, or the number of spray pulses being emitted per revolution of the forme cylinder a lower printing speed of the forme cylinder is higher and lower at a higher printing speed.
• a spray dampening system of a printing press is known from US Pat. No. 5,038,681, a dampening solution having a fixed pulse duration but a variable pulse repetition distance depending on the speed of a forme cylinder being able to be applied to a surface of a roller of the spray dampening system by means of nozzles.
• a spray dampening system for a printing press one surface preferably of a rotating roller through a plurality of Spray nozzles is sprayed with a dampening solution by activating the spray nozzles with a predetermined frequency and phase shift.
• the spray nozzles therefore spray one after the other cyclically in a fixed sequence, the time period between activation of the same spray nozzle always being the same.
• the pulse length ie the time during which the spray nozzles are open, is also preferably the same for all spray nozzles.
• the length of the area sprayed on the surface of the roller and a distance between successive sprayed areas depend on the working cycle of the spray nozzles and a surface speed of the roller.
• a spray dampening system for a printing press is known, an electronic control circuit controlling spray nozzles as a function of a detected machine speed of the printing press, a frequency of the spray pulses emitted by the spray nozzles preferably having a non-linear relationship to the machine speed.
• the spray frequency manually, e.g. B. with the help of graphical aids that show a relationship between the machine speed and a spray frequency to be set.
• damp curve is a graphic representation of damping D as a function of the speed of the forme cylinder.
• the moisture curve thus indicates which dampening D for a dampening solution dispenser, e.g. B. a nozzle in a spray bar to adjust.
• the dampening D quantifies a ratio between an adjustable dampening solution passage on the dampening solution dispenser to a maximum dampening passage.
• the amount of dampness can be varied by an operator of the printing press and can be set to any value in a range between blocking the spray nozzles up to their maximum flow rate.
• a change in the amount of moisture released by the spray nozzle is achieved via the ratio of its spraying time T on and pause time T 0 ff.
• preference is given to working with an on time that is as constant as possible, so that only the, off time is varied.
• T on it should be noted that a spray nozzle needs a certain minimum time to generate its spray cone and for the escape of a certain amount of moisture, so that the spraying time T o ⁇ cannot be set as short as desired.
• the invention has for its object to provide methods for adjusting a spray dampening system.
• a warning can be given before setting inadmissible, or at least undesirable, synchronization values; however, these correlations to be avoided can also be avoided.
• B. be excluded completely in terms of programming, which reduces the monitoring effort for an in-operation spray dampening unit and improves the quality of the printed products produced with an associated printing press.
• Fig. 1 is a perspective view of a spray dampening unit shown in a highly simplified manner
• FIG. 2 shows a flow diagram to illustrate the distribution of the spray pulses along a circumferential line of a rotating body, wherein a repetition duration of spray pulses is less than a rotation period of the rotating body;
• Fig. 3 is a flowchart showing the distribution of the spray pulses along a
• Circumferential line of the rotating body wherein a repetition duration of Spr spray pulses is greater than a rotation time of the rotating body.
• FIG. 1 generally shows a device for distributing a material 02 dispensed by a material dispenser 01 along a circumference U 0 3 of a rotating first rotary body 03, the material dispenser 01 being stationary with respect to the rotary body 03 at least during its dispensing of the material 02 is arranged and wherein the rotary body 03 during its rotation receives the material 02 on its outer surface along its circumference U 0 3 at a contact point 06 in a discontinuous quantity flow.
• a period T A0 3 of the first rotating body 03 for receiving the material 02 or its integer multiple nT A 03 with n 1, 2, 3 ...
• the following special correlations are preferably to be fulfilled:
• a time difference ⁇ T-i between the rotation time T 0 3 of the first rotating body 03 and the period should be T AO ⁇ to deliver material 02 or the period T A03 to take up material 02 or its integer multiples nT AO ⁇ ;
• nT 03 ⁇ T AD I; T A03 ⁇ (n + 1) * T 03 - T on with n 1, 2, 3 ...
• the dispensing time T on for the material 02 dispensed periodically by the material dispenser 01 can be variably adjustable within its period period T AO ⁇ , which is kept constant, while at the same time changing the pause time T off .
• the period T AO ⁇ can also be adjusted by adjusting the delivery time T on or the pause time T 0ff or both times T on ; T off can be variably adjustable.
• the dispensing period T on for the material 02 periodically dispensed by the material dispenser 01 and its period T AO ⁇ preferably begin at the same time, ie the period T AOt begins to count with the onset dispensing period T on for the material 02.
• An advantageous embodiment of the proposed device provides that the period T A0 ⁇ for dispensing the material 02 from the material dispenser 01 or the period T A03 of the first rotating body 03 for receiving the material 02 is at least twice the rotation time T 03 of the first rotating body 03 , thus T AO ⁇ ; T A 03> 2 * T 03 .
• the rotary body 03 If the duration of rotation T 03 of the first rotary body 03 differs from its period T A03 for receiving the material 02, the rotary body 03 inevitably picks up the material 02 at different points on its circumference U03 for at least a certain number of its revolutions. In some applications, it may be harmless with regard to the desired, as even as possible, distribution of the material 02 on the outer surface of the first rotary body 03 if, after a certain number of revolutions and thus repetitions of the revolution duration T 0 3, e.g. B from at least two, three, five, ten or any number of revolutions, material 02 is applied again in its full dose at the same point on its circumference U 03 .
• the temporal difference ⁇ T-i between the rotation period T 03 of the first rotating body 03 and the period T A o ⁇ for delivering the material 02 or the period T A03 for receiving the material 02 or its integer multiples nT AO ⁇ ; nT A03 with n 1,
• the time window excluded by the interval X from a permissible setting range should preferably be at most one tenth of the rotation duration T 0 3 of the first rotating body 03.
• these proposed settings for the duration of the time difference ⁇ ) or the interval X can be adapted to the respective conditions of the printing press.
• the material dispenser 01 can deliver the material 02 to at least one rotating second rotating body 04, which is preferably arranged axially to the first rotating body 03, the second rotating body 04 at least partially on the first rotating body 03 at a contact point 06 with the first rotating body 03 transfers.
• a plurality of rotating second rotating bodies 04 (FIG. 1) can also be provided, for. B. up to five in number, which form a transport chain leading from the material dispenser 01 to the first rotating body 03 for the material 02, one of the second rotating bodies 04 receiving the material 02 dispensed from the material dispenser 01 and at a contact point 07 to a subsequent second one Rotating body 04 at least partially transfers to this.
• second rotating bodies 04 are provided, this transfer from one to the next second rotating body 04 is repeated until the material 02 has reached the first rotating body 03.
• the dose of material 02 originally delivered by material dispenser 01 is reduced with each transfer to a next rotating body 03; 04 according to known laws (splitting law).
• a plurality of second rotating bodies 04 are provided, these can differ from one another in their diameter D 04 or their rotation duration T 04 .
• the diameter D 0 of at least one second rotating body 04 can also be smaller than a diameter D 03 of the first rotating body 03 (FIG. 1).
• the rotating body 03; 04 have z. B.
• the axial length L of the rotating body 03; 04 is z. B. in the range between 500 mm and 2400 mm, preferably between 1200 mm and 1700 mm. If the first rotating body 03 and the second rotating body 04 have different diameters D03; D 0 , the rotation time T03 and the rotation time T 0 can be in a quotient of the diameters D03; D 0 correspond to each other, especially when the rotating body 03; 04 z. B. are coupled by friction or a gear. The same applies to several second rotating bodies 04 with different diameters D 04 . However, it can also be provided that the rotating body 03; 04 are driven individually and independently of one another.
• the aforementioned correlations can also be a function of the diameters D 03 ; D ⁇ can be set.
• the correlations mentioned above with regard to the rotation time T 0 3 of the first rotary body 03 preferably apply accordingly to the correlation between the period T AO ⁇ for dispensing the material 02 from the material dispenser 01 and the rotation time T 04 of the second rotating body 04, on the outer surface of which the material 02 is applied by the material dispenser 01.
• the transport time T TR which corresponds to a throughput time of the material 02 through the device, depends on the number of second rotating bodies 04 present and their respective rotation time T 0 and on the arrangement of the contact points 06; 07 for transferring the material 02 from one to a next rotating body 03; 04, ie the time required to cover the path along a circumference U 0 of the second rotary body 04, which is between the individual contact points 06; 07 exists. The following therefore applies:
• the first rotary body 03 is, for. B. a forme cylinder 03 of a printing press, preferably an offset rotary printing press.
• the at least one second rotating body 04 is designed as a roller 04 z.
• the material 02 dispensed by the material dispenser 01 is then a printing substance or in particular a dampening solution 02, the material 02 preferably being sprayable, e.g. B. in the form of an aerosol that from a distance a on a moving surface, preferably a rotating outer surface of a rotating body 03; 04 discontinuously and quantitatively dosed, preferably by spraying.
• the material dispenser 01 is preferably designed as a nozzle 01, the nozzle 01 preferably ejecting the material 02 in a pulse-like manner and thus intermittently.
• several, preferably identical, material dispensers 01 e.g. B. in the form of several, preferably equidistantly spaced nozzles 01 in a spray bar 08 (Fig. 1).
• the period T AO ⁇ for dispensing the material 02 is composed of the dispensing duration T on of the material dispenser 01 and a pause time T off of the material dispenser 01 (FIGS. 2 and 3).
• the delivery time T on of the material dispenser 01, its pause time T or ⁇ or both times T on ; T off is preferably variably adjustable, in particular remotely controlled from a control station assigned to the printing press.
• the delivery time Ton of the material dispenser 01, its pause time T or ⁇ or both times T on ; T 0 f ⁇ are now set such that the desired correlation between the period T A01 for dispensing the material 02 and the rotation time T 0 3 of the first rotating body 03 or the duration of rotation T 04 of the second rotary body 04, if necessary taking into account the duration of transport T TR of the material 02 by the spray dampening unit.
• This setting is thus carried out as a function of the rotation time T 0 of the first rotary body 03 or the rotation time T u of the second rotary body 04.
• This setting and, if necessary, its adjustment is preferably carried out programmatically, ie with the aid of a program that for each possible value of the rotation time T 0 3 of the first rotating body 03 or the rotation time T 0 of the second rotating body 04 determines at least one value-based setting that fulfills the required correlations.
• the program only allows a permissible setting that fulfills the required correlations, whereas an operator of the printing press is at least warned of unfavorable or impermissible settings, provided that the program does not in itself exclude a setting that does not meet the required correlations as impermissible and thus a reference of the material application effectively prevents undesirable beating.
• a rotational frequency f 03 of the first rotary body 03 can preferably range from standstill to approximately 15 Hz, which corresponds to a rotational speed of more than 50,000 revolutions per hour.
• the latter specification is also referred to as the press speed of a printing press.
• the proposed device is designed as a spray dampening system, the spray nozzles 01, z. B. eight in number, stationary to a rotating second rotating body 04, ie a dampening roller, in the axial direction to the second rotating body 04 and at a distance a of z. B. 80 mm to 150 mm from this are arranged (Fig.
• the delivery time T on for the periodically released dampening solution 02 is adjustable between 5 ms and 30 ms by the spray nozzles 01 in a spray cone, which is directed towards the second rotating body 04 and widens towards the second rotating body 04.
• D 04 can be influenced and, if necessary, taking into account the transport time T TR in the presence of a plurality of second rotating bodies 04, the delivery time T on or the pause time T of the spray nozzles 01 are set such that the aforementioned correlations are met. This results in favorable correlations for every machine speed and configuration and also those which are to be avoided so that the most uniform distribution of the dampening solution on the lateral surface of the first rotating body 03 takes place.
• the correlations found should preferably be maintained over the entire range of the machine speed, but at least in the upper third of the Machine speed, ie in the main production area of the printing press.
• a z. B. double wide double circumference rotary printing machine e.g. B. a newspaper printing press, e.g. B. at a maximum speed of 45,000 revolutions per hour

Landscapes

• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• Rotary Presses (AREA)
• Application Of Or Painting With Fluid Materials (AREA)
• Reciprocating Pumps (AREA)
• Looms (AREA)
• Nozzles (AREA)
• Air Conditioning Control Device (AREA)
• Coating Apparatus (AREA)

Applications Claiming Priority (5)

Publications (2)

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• 2002
  • 2002-12-13 DE DE10258325A patent/DE10258325B4/de not_active Revoked
• 2003
  • 2003-10-21 WO PCT/DE2003/003487 patent/WO2004039587A1/fr active Application Filing
  • 2003-10-21 AU AU2003283192A patent/AU2003283192A1/en not_active Abandoned
  • 2003-10-21 DE DE50311381T patent/DE50311381D1/de not_active Expired - Lifetime
  • 2003-10-21 EP EP03775068A patent/EP1554120B1/fr not_active Expired - Lifetime
  • 2003-10-21 CN CNB2003801020464A patent/CN100572054C/zh not_active Expired - Fee Related
  • 2003-10-21 ES ES03775068T patent/ES2321605T3/es not_active Expired - Lifetime
  • 2003-10-21 US US10/532,573 patent/US7387067B2/en not_active Expired - Fee Related
  • 2003-10-21 AT AT03775068T patent/ATE427214T1/de active
  • 2003-10-21 JP JP2004547407A patent/JP4320300B2/ja not_active Expired - Fee Related

Non-Patent Citations (1)

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