WO2007115739A2

WO2007115739A2 - Washing apparatus for an offset printing press

Info

Publication number: WO2007115739A2
Application number: PCT/EP2007/002979
Authority: WO
Inventors: Klaus Strobl; Jürgen Hillenbrand
Original assignee: Technotrans Ag
Priority date: 2006-04-03
Filing date: 2007-04-03
Publication date: 2007-10-18
Also published as: WO2007115739A3; CN101410252A; EP2001681B1; DE102006015831A1; EP2001681A2; CN101410252B

Abstract

Disclosed is a washing apparatus for an offset printing press, comprising several washing points on the cylinders of the printing press and a supply system for delivering water, cleaning agent, and compressed air to spray a mixture of water and cleaning agent (detergent) onto the cylinder surfaces that are to be cleaned. The inventive washing apparatus is characterized by annular ducts (14, 16, 18) for the water, cleaning agent, and compressed air, which extend from a central supply unit (10) along all potential washing points of the printing press. Said annular ducts (14, 16, 18) are provided with a number of modular washing units (20, 22) which are located directly at the washing points and are coupled to or enclosed in the annular ducts (14, 16, 18), and valves (40, 42, 48, 50, 54) for discharging water, cleaning agent, and compressed air.

Description

WASHING DEVICE FOR AN OFFSET PRINTING MACHINE

The invention relates to a washing device for an offset printing machine with multiple washing points on the cylinders of the printing press, surfaces with a supply system for the supply of water and detergent and compressed air for spraying a water-detergent mixture (detergent) on the cylinder to be cleaned.

In offset printing, the printed image is on the peripheral surface of a so-called plate cylinder. From this, the printed image is transferred to the substrate via a blanket-covered cylinder, the blanket cylinder. Counter pressure cylinders press the printing material against the blanket cylinder so that the printing material picks up the printed image.

A washing device serves to spray the cylinder surface of the blanket cylinder and the impression cylinder from time to time with a detergent and wash with it. During the printing process, dirt collects on the surfaces of the cylinder, which consists essentially of paint residues and paper dust.

For the washing process usually washing devices are used, which are mounted directly on the affected cylinders. From a central supply point, which is usually formed by a detergent supply cabinet, water and cleaning agents, which are mixed to form a detergent, are fed into the individual washing stations. The supply of detergent and compressed air via lines or hoses from the detergent dispenser.

Object of the present invention is to provide a washing device of the above type, which allows to reduce the number of hoses and lines to individual washing points and to ensure a uniform supply and equal pressure conditions at all washing points. To achieve this object, a washing device according to the invention of the above type is characterized by loops for water, detergent and compressed air, which run from a central supply unit along all potential washing stations of the printing press, as well as a number of modular washing units directly to the washing stations, which is coupled to the ring lines or are enclosed in these and have valves for the delivery of water and detergent and compressed air.

According to the invention, a closed loop system is formed in which the individual modular washing units are integrated or to which they are coupled. In this way, prevail at all washing points equal pressure conditions for the detergent supply and the compressed air supply and thus a reproducible liquid distribution at the individual washing points. Decentralized washing units on each printing unit can considerably reduce the size of the central supply unit. It is therefore not necessary to accommodate a relatively large and correspondingly bulky supply cabinet in the vicinity of the printing press.

The valves required for each printing unit are provided in the individual modular washing units which are assigned to each printing unit so that only very short paths exist between the valves and the actual washing station. Possible metering errors are very low or completely negligible.

The modular washing units may have integrated channels in the form of bores.

Moreover, the individual washing units can be supplied with control pulses for actuating the valves via a data bus from a central control cabinet.

In the following preferred embodiments of the invention will be described with reference to the accompanying drawings.

The sole figure is a schematic representation of a washing device according to the invention. In the drawing, a supply unit for detergent and compressed air is designated 10. Reference numeral 12 refers to a machine control station that houses a data processor and an electronic controller.

From the supply unit go lines 14, 16, 18, are discharged through the detergent, water and compressed air. Parallel to the lines 14, 16, 18 extend dashed lines through which not separately designated return lines are reproduced. The lines 14, 16, 18 are designed as ring lines, which extend over all potential washing positions of the printing press.

According to the drawing, modular washing units 20, 22 are integrated into the loop system, which comprises the lines 14, 16, 18 and their return lines. In these washing units are channels 24,26,28.

The washing units 20, 22 are assigned to individual printing units or washing stations of a printing machine.

The washing units 20,22 are, for example, frame-shaped or box-shaped structures, which are crossed by lines 24,26,28, which can be integrated into the entire loop system or are coupled to this. In the embodiment shown in the drawing, the lines 24,26,28 form part of the entire loop system.

In the ring lines 14, 16, 18 are pressure relief valves 30,32,34, which ensure that the internal pressure in the lines of the loop system is limited and pressure peaks are avoided.

Within the washing units 20, 22, spur lines 36, 38 can be connected to the lines 24, 26, 28, which are used, for example, for the supply of

Detergent from the line 14 of the loop system to a first

Wash place care. For example, the stub 36 supplies detergent to the washing station on the blanket cylinder, while the stub 38 provides for the supply of water. The two lines contain ventiles 40,42, which will be discussed again later. Further branch lines 44, 46 start from the ring lines 16. They serve to supply water to the washing point on the blanket cylinder. In these stubs 44,46 are valves 48,50.

To the ring line 18, which carries compressed air, a stub 52 is connected to a valve 54.

The stubs 36,38,44,46 lead, for example, to a spray bar, not shown, which is parallel to the blanket cylinder and having a number of directed to the blanket cylinder nozzles. Water and cleaning agent are introduced into this spray bar, and then compressed air is supplied via the further branch line 52 so that the meanwhile produced mixture, which is also to be referred to here as detergent, is sprayed out through the nozzles.

The second washing unit 22 serves, for example, for washing the impression cylinder.

Of course, only one example is shown in the drawing. In large printing presses, the loop system described in this example can be considerably expanded. For larger machines, the particular advantages of the present invention result in a particularly clear manner.

It was stated that a data computer is located in the machine control station 12, which may offer the possibility of forming a central microprocessor control valve via control lines, which controls the valves of all washing units 20, 22 via control lines 56, 58.

Claims

1. A washing machine for an offset printing machine having a plurality of washing stations on the cylinders of the printing press, with a supply system for the supply of water and detergent and compressed air for spraying a water-detergent mixture (detergent) on the cylinder surfaces to be cleaned, characterized by Ring lines (14, 16, 18) for water, detergent and compressed air, which run from a central supply unit (10) along all potential washing stations of the printing machine, and a number of modular washing units (20,22) directly at the washing stations, the to the ring lines (14, 16, 18) are coupled or included in these and valves (40,42,48, 50,54) for the discharge of water and detergent and compressed air.

2. Washing device according to claim 1, characterized in that the modular washing units (20,22) are frame-shaped or box-shaped and have integrated lines for water, detergent and compressed air, of which stubs (36,38,44,46, 52) go out, leading to the individual washing areas.

3. Washing device according to one of claims 1 or 2, character- ized in that a central microprocessor control (12) is provided, which via control lines (56, 58) with the valves (40,42,48,50,54) of the individual Washing units (20,22) are connected and control them.