EP1029672A1 - Method and device for adjusting the impression pressure between rollers of a printing press - Google Patents

Abstract

The device comprises double piston hydraulic cylinders (HA/B,HB/C) that are radially connected between rubber roller (B) and adjacent rollers (A,C) for force loading the roller (B) to rollers (A,C), and hydraulic loop which allows cylinders to communicate with hydraulic pressure source (P). The hydraulic loop has shut-off valves (7,8) which lock position of the roller (B) with respect to rollers (A,C). An Independent claim is also included for the method of force loading rubber roller to adjacent roller in printing press.

Description

The invention relates to an apparatus and a method for adjusting the Contact pressure between rubber rollers and other rollers in the inking and dampening unit Printing press.

In inking units, rubber rollers or blanket rollers are used to transfer ink used by the ink fountain roller on the plate cylinder. In dampening systems, by means of Rubber rollers transfer dampening solution from one cylinder to another. The The rubber roller must be biased to do this. H. be employed on the other rollers. In the Printing shutdown of the printing unit or for cleaning the rubber blanket, it is advantageous to Put the blanket roller away from the other rollers. It also happens in operation often become one due to high temperatures and other dynamic factors Swelling of the rubber coating, so that the contact pressure between the Rubber layer and the other rollers changes. Many prior art devices Technology does not offer the possibility of dynamic adjustment of the contact pressure during a production run, since the setting of the contact pressure between the Rolling by adjusting the respective inking unit and dampening unit positioning mechanisms during machine setup. This is a time-consuming process that also involves adapting to the Operating temperatures and the associated swelling of the roller is not possible.

US 4,354,431 describes a device for preventing bending vibrations especially when the tension or rubber blanket channels of the cylinder Rotary press meet. The device comprises two on both sides of the Cylinder bearing spaced brackets, which have a first and a second tensioning rail are interconnected. The tensioning rails grip each of the with respect to the middle of the cylinder bearings offset end portions of the bracket. The first tensioning rail comprises a tensioning joint which interrupts the Connection between the two brackets allows to reduce the contact pressure. The second tensioning rail comprises a compression spring, which is controlled by a hydraulic or Pneumatic device can be replaced to the pressure exerted by the brackets to reduce. A disadvantage of this device is that the between the The force acting on cylinders does not act directly on the center of the cylinder bearing, but on the end sections of the stirrups offset with respect to the center, which creates lateral forces arise, which affect the setting of the two cylinders.

One attempt to solve the problems described is to stop the Pressure by means of motors. However, this setting system is complicated and maintenance-intensive. Furthermore, the lack of adaptation affects Temperature fluctuations in print quality.

Accordingly, it is an object of the invention, a method and an apparatus for Setting the contact pressure between rollers in the inking and dampening unit To create printing press in which the disadvantages of the known, Generic devices and methods are eliminated and the exact and constant contact pressure between a rubber roller and a respective other roller guarantee.

This object is achieved by the features of claims 1 and 10.

Further features of the present invention result from the subclaims.

A device according to the invention for adjusting the contact pressure between Includes rubber rollers and other rollers in the inking and dampening unit of a printing press a hydraulic actuator for positioning the rubber roller on the at least one adjacent roller, which with the rubber roller and the at least one adjacent Roller is connected and is in communication with a source of pressurized fluid.

In the hydraulic control element, it can be, for. B. a hydraulic Act double piston cylinder.

There is preferably a between the hydraulic actuating element and the pressure fluid source Activation valve arranged.

The activation valve is preferably an electronically controlled, hydraulic four-way valve. Furthermore, the hydraulic valve via an electrical Signal line connected to a user interface, either as a separate User interface only for setting the contact pressure between the rubber rollers can be formed or integrated into the main user interface of the printing press can be. The control of the contact pressure can also be computer controlled.

Furthermore, in the pressurized fluid circuit, which connects the hydraulic control element to the Pressure fluid source connects, a check valve can be integrated.

As an alternative or in addition, the hydraulic fluid circuit containing the hydraulic control element can be used connects to the pressure fluid source, a pressure regulator can be integrated.

The rubber roller can be used as an ink transfer roller of an inking unit Printing machine be formed, and the at least one adjacent roller can, for. B. be designed as a friction roller.

The at least one roller adjacent to the rubber roller is preferably one Axle mounted in the frame of the machine, while the rubber roller preferably by one with respect to the machine frame by means of a hydraulic Adjusting element movably arranged axis is rotatable.

The inventive method for adjusting the contact pressure between one The rubber roller and an adjacent roller in a printing machine include the following Process steps: loading one between a rubber roller and one adjacent roller arranged hydraulic actuator with pressure, the Rubber roller placed on the adjacent roller by means of the hydraulic adjusting element and adjusting the pressure in the hydraulic actuator for adjusting the Contact pressure between the rubber roller and the adjacent roller.

According to the invention, the contact pressure is preferably set in a employed position of the rubber roller. However, the rubber roller is preferably in one Formed so that they can be parked by the adjacent roller and when necessary can be spaced.

According to the invention, there is an automatic adaptation to temperature fluctuations and other dynamic changes because the pressure acting in the system is direct is proportional to the contact pressure of the rubber roller. Compared to devices of the The prior art is reduced by the device according to the invention Maintenance effort, an automatic adjustment to temperature fluctuations and a Print quality improvement achieved.

The features of the present invention will become apparent in the following description preferred embodiments in connection with the accompanying, below listed drawing explained in more detail.

The drawing is a schematic top view of one adjacent two rollers employed rubber roller and a hydraulic pressure system according to the invention.

In the accompanying drawing, one is attached to a roller A and a roller C. Rubber roller B of a rotary printing machine shown. On the cylinder body of the Rubber roller B is a rubber blanket or rubber coating 1 applied. The roller C can e.g. B. be designed as a nylon coated ink roller. Rollers A, B and C rotate about mutually parallel axes.

The rollers can e.g. B. may be arranged in a web-fed rotary printing press. If it is in particular a double-width newspaper printing press, the rubber roller B is placed against the roller A and / or C with a maximum contact pressure of 18 N / cm. With a 100 cm long rubber roller strip, a contact pressure of 1800 N would be necessary. According to the invention, this force is applied by hydraulic actuating elements in the form of the hydraulic cylinders H _{A / B} and H _{B / C} , which according to the preferred embodiment of the invention, as shown in the single figure, are preferably designed as double-acting cylinders on their respective piston rods, or on the cylinder housing of which the respective roller axes are attached. As can be seen in the figure, the double-acting cylinders are each provided on both sides of the piston with supply lines for a pressure fluid, for example hydraulic fluid, via which the pressure fluid, as described in detail below, into the two working chambers arranged on either side of each of the pistons is fed. In the same way, however, it is also possible to design the cylinders as double-piston cylinders with two pistons acted upon by the pressure fluid, which are separated by a partition, and the associated piston rods of which are each connected to the rubber roller B and the rollers A and C. In the given example, each hydraulic cylinder applies 900 N.

An advantageous operating contact pressure of the hydraulic cylinders, in which the piston friction can be neglected, is 700 N / cm ² (≈ 1000 psi). A hydraulic cylinder with an inner diameter of 1.3 cm (≈ 0.5 ") applies the necessary force of approx. 900 N with 700 N / cm ² pressure (force is equal to pressure times the area).

Abstellung" und Anstellung" gekennzeichnet und unabhängig von einander betätigbar sein, so dass die Gummiwalze B beispielsweise an die Farbreiberwalze C angestellt sein kann, während sie von der Walze A abgestellt ist. In der Regel wird die Gummiwalze B jedoch gleichzeitig an beide Walzen A, C angestellt sein bzw. von beiden abgestellt sein. Die Ventile 3 und 4 werden über die elektrischen Signalleitungen E elektrisch betätigt. Die Signalleitungen E können mit einer nur für die Walzeneinstellung vorgesehenen Nebenbedienoberfläche 9 oder mit der zentralen Bedienoberfläche des Druckwerks und/oder der Druckmaschine verbunden sein. Der über die Ventile 3, 4 wirkende Druck wird von einer Druckfluidquelle P aufgebracht.Each of the hydraulic cylinders H _{A / B} and H _{B / C} is controlled by a four-way valve 3, 4. The valves can with

Shutdown "and Employment "and can be actuated independently of one another, so that the rubber roller B can, for example, be applied to the inking roller C while it is switched off from the roller A. As a rule, however, the rubber roller B will be applied to both rollers A, C at the same time The valves 3 and 4 are electrically actuated via the electrical signal lines E. The signal lines E can be connected to an auxiliary control surface 9 provided only for the roller adjustment or to the central control surface of the printing unit and / or the printing press Pressure acting via the valves 3, 4 is applied by a pressure fluid source P.

_A pressure regulator 5, 6 is integrated into the hydraulic circuit of the hydraulic cylinders H _{A / B} and H _{B / C} , the pressure regulator 5 regulating the contact pressure between the rollers A and B and the pressure regulator 6 regulating the contact pressure between the rollers B and C, if the four-way valves 3, 4 are set accordingly.

In each of the hydraulic circuits, a check valve 7, 8 is also preferably integrated, by means of which the position of the rubber roller B and the adjacent rollers can preferably be locked after the desired contact pressure has been set via the pressure regulators 5, 6. As shown in the figure, the check valves 7, 8 assigned to each of the hydraulic cylinders H _{A / B} and H _{B / C} are preferably corresponding in one of the supply lines for the pressure fluid to the respective working chamber of the double-acting cylinder and the associated pressure regulator 5, 6 arranged in the other supply line for the pressure fluid. The positional relationships are locked because the hydraulic fluid cannot be compressed. The shut-off valve can be opened and closed again, preferably at regular intervals, for position adjustment and automatic pressure adjustment during the pressure operation, whereby the pressure fluid source P, with a corresponding position of the valves 3, 4, the hydraulic cylinders H _{A / B} and H _{B / C} via the pressure regulator 5, 6 pressurized with pressure fluid predetermined pressure.

Here it becomes clear that a swelling of the rubber roller due to Temperature fluctuations or other dynamic factors in the system automatically be compensated. It is also pointed out that the check valves 7, 8 preferably remain permanently open, but e.g. B. in the event of an occurrence of Vibrations can also be closed.

List of reference numbers

1

Rubber cover

3rd

Four-way valve

4th

Four-way valve

5

Pressure regulator

6

Pressure regulator

7

Check valve

8th

Check valve

9

Secondary user interface

A

roller

B

Rubber roller

C.

roller

H _{A / B}

Hydraulic cylinder

H _{B / C}

Hydraulic cylinder

P

Pressurized fluid source

E

electrical signal lines

Claims (12)

Device for adjusting the contact pressure between a rubber roller (B) and at least one roller (A, C) adjoining them in a printing press
marked by
a hydraulic actuating element (H _{A / B} , H _{B /} C) connecting the rubber roller (B) to the at least one adjacent roller (A, C), which can be acted upon by a pressure fluid source (P) in such a way that the pressure fluid Rubber roller (B) can be set with a predetermined contact pressure on the adjacent roller (A, C). Device according to claim 1,
characterized,
that the hydraulic control element (H _{A / B} , H _{A / C} ) is designed as a double-acting cylinder, in which the working chambers arranged on both sides of the piston can be acted upon by pressurized fluid via separate lines. Device according to one of the preceding claims,
characterized,
that an activation valve (3, 4) is arranged between the hydraulic control element (H _{A / B} , H _{B / C} ) and the pressurized fluid source (P). Device according to claim 3,
characterized,
that the activation valve (3, 4) is designed as a four-way valve. Device according to claim 4,
characterized,
that the hydraulic valve (3, 4) is designed as an electrically controllable valve which is connected to an operating surface (9) via an electrical signal line (E). Device according to one of the preceding claims,
characterized,
that a check valve (7, 8) is integrated in the pressure fluid circuit which connects the hydraulic control element (H _{A / B} , H _{B / C} ) to the pressure fluid source (P). Device according to one of the preceding claims,
characterized,
that a pressure regulator (5, 6) is integrated in the pressure fluid circuit, which connects the hydraulic control element (H _{A / B} , H _{B / C} ) to the pressure fluid source (P), with which the contact pressure of the rubber roller (B) is applied to the adjacent roller (A, C) can be changed. Device according to claims 6 and 7,
characterized,
that the check valve (7, 8) and the pressure regulator (5, 6) are arranged in separate feed lines which feed the pressure fluid into separate working chambers of the hydraulic actuating element (H _{A / B} , H _{B / C} ). Device according to one of the preceding claims,
characterized,
that the rubber roller (B) is designed as an ink transfer roller in an inking unit of the printing press and the at least one adjacent roller (A, C) is designed as a friction roller. Device according to one of the preceding claims,
characterized,
that the at least one adjacent roller (A, C) can be rotated about an axis fixed to the frame in the machine frame of the printing press and that the rubber roller (B) can be rotated about an axis that can be moved with respect to the machine frame by means of the hydraulic adjusting element. Method for adjusting the contact pressure between a rubber roller (B) and an adjacent roller (A, C) in a printing press,
marked by
the following steps: Acting a hydraulic actuating element (H _{A / B} , H _{B /} C) arranged between the rubber roller (B) and the adjacent roller (A, C) with a pressure fluid in such a way that the rubber roller (B) is actuated by the hydraulic adjusting element ( H _{A / B} , H _{B / C} ) is placed on the adjacent roller (A, C), and Interrupt the fluid supply after reaching the specified contact pressure. A method according to claim 11,
characterized,
that the interruption of the fluid supply from the pressurized fluid source (P) to the hydraulic actuating element is canceled again after a predetermined period of time in order to apply a predetermined pressure to the hydraulic actuating element again.

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