JPH0319066B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a method and a device for adjusting the position of individually adjustable ink metering elements with an ink section width relative to the ink ductor roller of an ink fountain of a printing press, for example by means of an electric motor. Regarding.

It is known to adjust an ink metering element with an ink section width by means of an electric motor (DE-A-2814889). In this case, the position of the ink metering element is not indicated, so that any play between the electric motor and the ink metering element does not pose a problem.

The object of the invention is to provide a method that produces a precise position of the ink metering element even if there is play in the drive mechanism.

A particular advantage of the invention is that a very precise adjustment of the ink metering element is possible even if there is play in the drive mechanism for the ink metering element. By using a step motor as a drive device for each individual ink metering member and adding up the number of steps of the step motor, the position of the ink metering member can be easily indicated. As the drive mechanism for adjusting the ink metering member, it is possible to use a drive mechanism that does not have very high mechanical precision and is extremely inexpensive. This requires a unique drive mechanism for each ink metering member.
This is a huge advantage. It is also possible to accurately adjust the ink metering member in both directions without knowing exactly the play of the drive member. Compensation for play can be easily accomplished. Furthermore, play compensation can be easily adapted to increased wear.

In the following, the configuration of the present invention will be specifically explained with reference to embodiments shown in the drawings.

A driven ink ductor roller 2 is located in an ink fountain 1 of a rotary printing press. In order to adjust the ink thickness for each ink section, a number of ink metering elements 3, which can be pivoted in a known manner, are arranged closely next to each other. The ink metering element 3 is pivotable about a pivot edge 4 of the bottom 6 of the ink fountain 1 . A pivoting arm 7 is fixed to the ink metering element 3 for driving the ink metering element 3. The lower part 8 of the swivel arm 7 is formed with an open control groove 9, which forms two vertical control surfaces 1
0.15. A control roller 12, which is mounted eccentrically on a gear wheel 11, engages in the control groove 9. The gear 11 via a large number of gears 13,
It is connected to a pinion 14 of a step motor 16 whose rotation direction can be switched.

The drive mechanism of each ink metering element 3 with its ink metering edge 21 has play. Each drive member (9, 12, 11, 13, 1) of the ink metering member 3
4) has play of various sizes, the total value of which is represented by the total amount of play a. This total amount of play a
The magnitude of the step motor 16 is determined and converted into the number of steps of the step motor 16. The motor shaft of the step motor 16 rotates in one direction or the other by a precisely determined angle for each step.

In order to simplify the explanation, only one ink metering element 3 of the ink fountain 1 will be described below.

The ink is removed by the weight of the ink in the ink fountain 1 or by the force acting when the ink is conveyed through the ink gap b between the ink metering edge 21 and the outer circumferential surface of the ink fountain roller 2. The metering member 3 is always subjected to a moment about the pivot edge 4 in the same direction A (eg clockwise in FIG. 1). In other words, the control surface 15 on the right side of the control groove 9 of the pivoting arm 7 is in contact with the control roller 12 .

The number of steps necessary to compensate for the total play a of the drive mechanism of the ink metering element 3 can be determined by practical tests or calculated.
However, it is sufficient to choose a number of steps that reliably exceeds the total amount of play a. Of course, in practice, in order to shorten adjustment time as much as possible,
It is desirable to find the number of steps as accurately as possible.

When the pivoting arm 7 with the ink metering member 3 is pivoted in the clockwise direction A around the pivoting edge 4, the ink gap b increases and the thickness of the ink film on the ink dispenser roller 2 increases. On the other hand, when the ink metering member 3 is turned in the counterclockwise direction B, the ink gap b is reduced and the thickness of the ink film on the ink dispenser roller 2 is reduced. By the way, when reducing the ink gap b between the ink metering member 3 and the ink dispenser roller 2 by the amount c, the step motor 16 is
must be rotated in the negative direction by the number of steps corresponding to . As a result, the pivoting arm 7 is pivoted counterclockwise about the pivoting edge 4 by means of the control roller 12. In this case there is no need to compensate for play in the drive mechanism. it is,
Because of the force exerted by the ink in the fountain 1 on the ink metering element 3 and thus on the pivot arm 7, the control surface 15 on the right side of the control groove 9 is constantly pressed against the control roller 12.

In order to increase the ink gap b between the ink metering member 3 and the ink dispenser roller 2 by an amount d, the step motor 16 must be rotated in the positive direction by a number of steps corresponding to the amount d. As a result, the pivoting arm 7 is pivoted clockwise about the pivoting edge 4 by the control roller 12. The ink in the ink fountain 1 exerts a moment on the ink metering member 3 and thus on the pivot arm 7, pressing the control surface 15 on the right side of the control groove 9 against the control roller 12. However, when increasing the ink gap b, is the drive mechanism (9, 10,
15, 11, 13, 14) must be additionally compensated for, and for this purpose the stepper motor 16 must additionally be rotated in the positive direction by steps corresponding to the total amount of play a.

The desired increase in the ink gap b by the amount d is accomplished as follows.

First, the number of steps corresponding to the desired adjustment amount d of the ink metering member 3 is determined, and the computer part in the microprocessor adds to this number of steps the number of steps corresponding to at least the total amount of play a and, if necessary, additional adjustment. Add a step number of at least 1 corresponding to the quantity z. The step motor 16 is controlled by a well-known electronic control device 5 to rotate in the positive direction by an adjustment step of d+a or d+a+z. The step motor 16 then rotates in the opposite direction by a or a+z adjustment steps.

Next, when adjusting in the direction of reducing the ink gap, the step motor 16 makes the desired reduction without adding the number of steps corresponding to the total play amount a and the number of steps corresponding to the additional adjustment amount z. It rotates in the negative direction by the number of steps corresponding to the adjustment amount c.

As can be seen from Fig. 2, the ink metering member 3
When adjusting the ink metering element 3 or the pivot arm 7, the ink metering element 3 or the pivot arm 7 is always in contact with its drive mechanism without play.

That is, in FIG. 2, the ink metering member 3 is moved from position L by an amount c in a direction that reduces the ink gap.
Considering the case where the control roller 12 is adjusted in position L, the control roller 12 is in contact with the control surface 15 on the right side of the control groove 9, and in this state, the control roller 12 is in contact with the right control surface 15 of the control groove 9.
2 presses on the control surface 15 on the right side of the control groove 9, so that the pivoting arm 7 with the ink metering element 3 is pivoted counterclockwise by a number of steps corresponding to the quantity c and reaches the position M. As a result, the ink metering member 3 itself turns in the direction B, and the ink gap b is accurately reduced by the desired amount c. In this position M, the control roller 12 remains in contact with the control surface 15 on the right side of the control groove 9.

If we then consider the case of pivoting the ink metering element 3 from the position M by an amount d in the direction A increasing the ink gap, this position M where the control roller 12 is in contact with the control surface 15 on the right side of the control groove 9 from step motor 16 and control roller 1
2 first performs an adjustment movement corresponding to the total play a,
This causes the control roller 12 to come into contact with the control surface 10 on the left side of the control groove 9, and only then does the control roller 12 pivot the pivoting arm 7 clockwise to a predetermined intermediate position N. In this case, the step motor 16 rotates in the positive direction by a number of steps corresponding to the sum of the total play amount a, the desired increase amount d, and optionally the additional adjustment amount z. When position N is reached, the step motor 16 is automatically reversed by a number of steps corresponding to a+z by means of corresponding programming of the microprocessor of the electronic control unit 5, so that the control roller 12 is moved onto the right control surface 15. Contact brings the pivoting arm 7 to the final position P (MN-NP=PM=d). Any adjustment in the negative or positive direction (c
Or d) can be performed in the same way.

Of course, the adjustment movement of the ink metering element 3 can be controlled by mechanical or electrical means to prevent damage to the ink ductor roller surface 20.

It should be noted that it is not necessary to individually compensate for the total amount of play a specific to the drive mechanism for each ink metering member 3, and the maximum value a of these total amounts of play is common to all the ink metering members 3. It is enough to apply it. When all the ink metering members are adjusted in the positive direction, they can be adjusted by adding this maximum value ag and, if necessary, an additional adjustment amount z to the desired adjustment amount d.

In addition, the increase in the amount of play due to wear and tear on the drive mechanism
This can be easily dealt with by changing a or a+z.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram of an ink fountain with a pivotable ink metering member, and FIG. 2 is a schematic diagram illustrating the adjustment operation of the ink metering member. 1... Ink fountain, 2... Ink dispenser roller,
3... Ink metering member, 4... Swivel edge, 5... Control device, 6... Bottom, 7... Swivel arm, 8... Lower portion, 9... Control groove, 10... Control surface, 11
... Gear, 12 ... Control roller, 13 ... Gear,
14...Pinion, 15...Control surface, 16...Step motor.

Claims (1)

[Scope of Claims] 1. A method for adjusting an ink metering member having an ink division width of an ink fountain of a printing press by a drive mechanism with play, in which the drive mechanism adjusts the ink metering member in a direction with play. When carrying out an adjustment movement, the drive mechanism is first moved by at least the sum of the desired adjustment amount d and the total play amount a of the drive mechanism, and then by the difference between this sum and the desired adjustment amount d. A method for adjusting an ink metering member with an ink section width of a printing press, characterized in that the drive mechanism is moved back in the opposite direction. 2. In a method for adjusting an ink metering member having an ink division width of an ink fountain of a printing press by means of a drive mechanism with play, first the desired adjusting movement of the drive mechanism engaged with the ink metering member is carried out. Check the total play amount a in the direction, set the total value of this total play amount a and the additional adjustment amount z, determine the adjustment amount d of the ink metering member, and then adjust the drive mechanism to the total value ( a+z) plus the adjustment amount d (a+z+d)
in the direction of the desired adjustment movement, and then by the difference between this movement value (a+z+d) and the adjustment amount d,
A method for adjusting an ink metering member with an ink section width of a printing press, characterized in that the drive mechanism is moved back in the opposite direction.