JP2782211B2 - How to preset the ink supply - Google Patents

Description

The present invention relates to an ink supply method for an offset printing press.

[Prior art] Conventionally, an ink supply method using an ink key in a printing machine is based on the ink film thickness on paper and the position of the ink key with reference to the outer peripheral surface of an ink fountain roll (hereinafter referred to as ink key opening). On the premise that the ink keys are in a proportional relationship, a method has been adopted in which the positions of the ink keys are controlled to supply an optimum amount of ink. However, the ink film thickness on the ink fountain roll and the key opening are not linearly proportional in reality, but each depends on the error between the screw shaft that moves the ink key and the fixed nut, the viscosity of the ink, etc. Has a key-specific error. For that purpose, ink
Even when the screw shaft integrated with the key is driven by a servomotor to position the ink key, it has been difficult to obtain a desired ink film thickness on paper.

That is, conventionally, when setting the ink film thickness of the ink ejection roll from the ink film thickness data on paper,
Since the ink film thickness on the ink fountain roll could not be set directly, the ink key opening was set and printed as being linearly proportional to the ink film thickness on the ink fountain roll. However, even if the ink key opening has the same value for each ink key, the ink film thickness on the ink ejection roll in each ink key does not match. That is, even if the ink key opening between each ink key and the ink roll outer peripheral surface is made the same, the ink film thickness of each ink key on the ink roll does not match. In other words, due to problems such as mechanical manufacturing accuracy, the ink film thickness on the ink delivery roll differs for each ink key and varies.

To correct this, a table for converting preset data (for example, picture area ratio data) into ink key opening data is provided to position the ink keys. However, this method cannot incorporate the characteristics of the individual ink keys, and it has been difficult to obtain a desired ink film thickness on paper.

[Problems to be Solved by the Invention] The present invention has been made in view of the problems of the prior art, and an object of the present invention is to provide a method for presetting an ink supply amount for obtaining an optimum ink film thickness on paper. To provide.

[Means and Actions for Solving the Problems] The present invention has the following means and actions to solve the above problems.

The ink key is controlled according to each pattern corresponding to each zone where the printing plate surface is divided into multiple parts, and the preset method of the optimum ink supply amount is based on the ink film thickness on paper and the outer peripheral surface of the ink supply roll The measured values of the positions of the ink keys (openings of the ink keys) are stored in advance in a memory table related to the servo controller, and the required ink film thickness on the ink fountain roll is obtained by referring to the memory table. The position of the ink key is controlled so as to obtain a desired ink film thickness on paper.

That is, the ink key opening (PT
Value), the ink film thickness value on the ink dispensing roll is determined in advance, and this is used to make corrections when presetting the ink key opening for each ink key from the ink film thickness data on paper, Precise ink key opening can be preset so that the ink film thickness on the ink delivery roll corresponding to the key becomes an appropriate value.

EXAMPLES Examples of the present invention will be described below.

First, the relationship between the ink key opening and the ink film thickness is determined as shown in FIG. In addition, this ink film thickness is a predetermined ratio 0%, 10%, 30%, 100% to a certain reference ink film thickness.
The ink opening is indicated by the position of the ink key 2 and the outer peripheral surface of the ink fountain roll 1. A plurality of ink keys 2 are arranged in parallel along the cylindrical surface of the ink fountain roll 1. The movement of this ink key 2
Screw the screw shaft 3 into the nut 2a provided at the rear of the key 2,
A servo motor 4 for rotating and driving the screw shaft 3 is fixed.

5 is a guide rail, and the film thickness measuring element 6 is a guide rail 5.
The upper part is made freely movable, and the ink film thickness on the ink discharging roll 1 is measured.

The film thickness measuring element 6 is connected to a light emitting / receiving section 8 through an optical fiber 7, and the ink key 2 is controlled so that the film thickness of the ink on the ink discharging roll 1 is 0%, 10%, 30%,. Is adjusted, and the data PT value (ink key opening) of the potentiometer 9 connected to the screw shaft 3 corresponding to the film thickness of the ink on the ink discharge roll 1 is stored in the memory table 11 as shown in FIG. . The film thickness measuring element 6 is positioned at a predetermined measuring position by the driving device 12, and the film thickness (of the ink on the ink discharging roll 1) is measured.

Next, adjust the ink and ink according to each pattern corresponding to the plate surface.
A method for controlling the keys and supplying the optimum ink will be described.

First, the position of the ink key 2 based on the ink film thickness on the paper and the outer peripheral surface of the ink fountain roll, ie, the ink key opening (PT value), is stored in the memory 11 in correspondence with the ink film thickness on the ink fountain roll. Remember.

The servo motor 4 is driven by the servo controller 10 based on the data of the ink key opening (PT value) corresponding to the ink film thickness on the paper and the ink film thickness on the ink fountain roll in the memory table 11. , For each ink key 2, the ink
The key is positioned (set of the PT value, which is the opening of the ink key) to obtain the required ink film thickness on the ink fountain roll to obtain the desired ink film thickness on the paper. That is,
When printing is performed, it is possible to obtain a printed material having a desired ink film thickness on paper.

[Effects of the Invention] As described above, according to the present invention, the printing plate surface is divided into a plurality of portions and the ink and
Since the keys are controlled and the actually measured values of the ink film thickness on the paper and the ink key opening are stored in advance in a memory table related to the servo controller, a desired ink film thickness on the paper can be obtained.

[Brief description of the drawings]

1 and 2 are drawings showing an embodiment of the present invention. FIG. 1 is a diagram showing the relationship between the ink film thickness on the ink fountain roll 1 and the opening of the ink key, and FIG. The block diagram of the control system which controls the ink film thickness on the roll 1 is each shown. 1: Ink roll, 2: Ink key, 2: Screw, 4: Servo motor

Continuation of front page (58) Field surveyed (Int.Cl. ⁶ , DB name) B41F 31 / 02,31 / 04

Claims (1)

(57) [Claims] 1. A method for presetting an ink supply amount for controlling an ink key in accordance with each picture corresponding to each of a plurality of divided zones of a printing plate surface to supply an optimum amount of ink. The measured values of the ink key position (ink key opening) based on the film thickness and the outer peripheral surface of the ink discharge roll are stored in advance in a memory table related to the servo controller, and the memory table is referred to. A method for presetting an ink supply amount by controlling the position of the ink key so as to obtain a desired ink film thickness on paper by making the ink film thickness on the ink ejection roll appropriate. .