JPH0723258Y2 - Box bed of flatbed offset printing machine - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial application] The present invention relates to a plate bed or a structure of a printing bed of a flatbed printing machine, and in particular, a vacuum convenient for attaching and detaching the plate and printing material to and from the bed. And a bed of a flatbed offset printing machine having a structure related to a blow air system and a heat medium system for adjusting a bed temperature for improving print quality.

[Prior art]

Conventionally, the temperature of the plate bed is adjusted, for example, to near the dew point temperature at room temperature to help control the amount of dampening water on the plate. It is known to have a single function, such as one that prevents sticking due to adsorption and printing.

However, the plate bed has vacuum pores for adsorbing the plate to the bed, and the vacuum pores can also be used as blowing pores, and further improves ink receptivity to the plate. In the past, there is no known one provided with a heat medium circulation passage for controlling the plate bed temperature for preventing the plate stain and plate stain.

Further, the printing bed has pores used for both vacuuming and blowing for adsorbing the printing material to the bed and lifting it up, like the plate bed described above. There is no known one provided with a heat medium circulating passage for controlling the temperature of the print bed for improving the transferability to

Conventionally, a method of applying ink on the plate bed has been generally used in order to firmly fix the plate to the plate bed, but this method is very troublesome, and it must be wiped clean after use, which is extremely inconvenient. Yes, it took time to install and remove the plate. Further, in this case, once the plate was brought into close contact with the plate bed, it was almost impossible to make subsequent fine adjustments.

The above-mentioned conventional flatbed printing machine is used as a proofreading machine for paper printing or for printing nameplates, and no one suitable for printing on a printed circuit board has been known.

[Problems to be solved by the invention]

The present invention is a plate for a flatbed offset printing machine, which is suitable for high-precision, high-density fine pattern printing by a waterless planographic printing method using a resist ink having a relatively high viscosity, and has good workability. It is an object to provide a bed or printing bed, or an improved plate bed or printing bed for a flatbed offset printing machine whose plate type is gravure or letterpress.

[Means for solving problems]

The bed of the flatbed printing press of the present invention for solving the above problems is a plate or printing bed of a box-type flatbed offset printing press having a chamber inside the bed upper wall, four side walls and a bottom plate. The partition wall forms one or more air chambers with the bed upper surface wall, and the bottom plate provided below the partition wall forms one or more bed temperature control heat medium chambers with the first partition wall. And a large number of pores penetrating the upper wall of the bed and communicating with the air chamber, and the side wall is provided with an air pipe attachment port and a heat medium for connecting the air chamber to an external vacuum or blow air source. It is characterized in that at least two attachment ports for the heat medium pipes that connect the chamber and the external heat medium circulation device are provided.

The partition wall is preferably a metal plate laminated with a rubber plate having a large sealing effect. However, other materials may be used as long as they are not attacked by water, oil, etc. used as a heat medium and have a sealing effect.

When the bed of the present invention is used as a plate bed, the temperature of the plate should be appropriately maintained in order to improve the inking property of the ink to the plate and at the same time to prevent so-called plate stain, which causes ink to adhere to areas other than the image area. is necessary. Therefore, when the room temperature is low, the heat medium is heated and circulated in the heat medium chamber, and when the room temperature becomes too high or the machine temperature rises, the temperature of the bed temperature control heat medium is cooled. The supply controls the bed temperature, and consequently the plate temperature, to the most suitable temperature for resolving both ink inking and plate stains. Depending on the purpose, the plate bed and the printing bed may have different temperatures or the same temperature.

[Action]

In order to perform printing with a flatbed offset printing machine equipped with the bed of the present invention, a) heating or cooling the heat medium and circulatingly supplying it to the heat medium chamber of the bed, the temperature of the plate bed and the print bed is adjusted.

B) Turn on the air source.

C) Place the plate at a predetermined position on the plate bed, connect the air chamber to the vacuum side of the air source, and fix the plate on the plate bed by the negative pressure acting on the pores. It should be noted that when positioning the plate, the air chamber may be set to a slightly weaker blow to smooth the movement adjustment of the plate.

D) Next, after placing the printing material on the printing bed and positioning it, the air chamber is connected and fixed to the vacuum side of the air source. Also in this case, the air chamber may be connected to the blow side of the air source when performing positioning before fixing.

E) Perform a test print, inspect whether the registration is correct, if it is okay, perform the actual printing as it is, and if there is misregistration, finely adjust the position of either the plate or the printing material, or both Therefore, the air chamber of the bed is separated from the vacuum air source, a small amount of the plate or printing material is moved, and then the air source is switched to the vacuum side.

〔Example〕

FIG. 1 is a perspective view of an embodiment of a flatbed offset printing machine according to the present invention as seen from below the bed, and FIG. 2 is a vertical sectional view taken along the line I--I of FIG.

The bed of the flatbed offset printing machine shown in FIG. 1 has a substantially box-like shape composed of a bed top wall (1), four side walls (2) and a bottom plate (5), and a partition wall provided inside. The air chamber (4) is formed by (3), and the heat medium chamber (6) is formed by the bottom plate (5) provided therebelow.

The partition wall (3) is fastened by bolts (15) to the step (14) inside the side wall (2), the step (14) of the cross-shaped rib (11) and the top surface of the rib (10). .

The air chamber (4) is divided into eight small chambers by the ribs (10) and (11), and all the small chambers communicate with each other through a through hole (12). The air chamber (4) is connected to the blower or vacuum air source (not shown) through the air pipe mounting port (8).
Further, the pressurizing air is filled or kept in a negative pressure state by a switching means such as a solenoid valve (not shown).

The bed upper surface wall (1) is provided with a large number of funnel-shaped pores (7). The spacing and arrangement of the pores can be selected appropriately.

The heat medium chamber (6) is divided into four by the rib (11),
The chambers are communicated with each other by a through hole (13). The heat medium supplied from the heat medium pipe mounting port (9) sequentially flows through the respective chambers, exits from the heat medium pipe mounting port (9 '), and returns to a heat medium circulating device such as a heat exchanger (not shown). In addition, in order to make the heat medium flow smoothly in the heat medium chamber without stagnation, a zigzag partition may be separately provided in each heat medium chamber by another material.

The construction and mounting method of the bottom plate (5) are the same as those of the partition wall (3).

Further, the number of air chambers (4) and the number of heat medium chambers (6) are not particularly limited.

[Effect of the Invention] Since both the plate bed and the printing bed are provided with the pores connected to the vacuum and blowing air chambers, the plate and the printing material can be easily and surely fixed to the bed. or,
Even when the plate and the printing material are moved by a small amount to match the register, it is advantageous that the vacuum and the blow can be easily switched.

Since the bed temperature control heating medium chamber is provided in both the plate bed and the printing bed, it is possible to improve the ink receptivity to the plate and the transferability of the ink from the blanket to the printing material. This is particularly noticeable when a resist ink having a high viscosity is used.

In addition, since the main part of the bed is easily manufactured by casting and there are few complicated machining parts, the manufacturing cost is low.

[Brief description of drawings]

1 is a perspective view of the bed according to the present invention seen from the back side, FIG. 2 is a sectional view taken along the line I--I of FIG. 1, and FIG. 3 is a schematic side view of a flatbed offset printing machine. 1 ... Bed top wall, 2 ... Bed side wall, 3 ... Partition wall, 4 ... Air chamber, 5 ... Bottom plate, 6 ... Heat medium chamber, 7 ...
… Pores, 10,11 …… ribs, 12 …… through holes, 13 …… steps.

Claims (2)

[Scope of utility model registration request] 1. A plate or a printing bed of a box-type flatbed offset printing machine having a chamber inside which is composed of a bed upper wall, four side walls and a bottom plate, wherein the chamber is divided by a partition wall (3) into the bed upper wall (1). And one or a plurality of air chambers (4) are formed between the partition walls and the bottom plate (5) provided below the partition wall, and one or a plurality of bed temperature controlling heat mediums between the partition wall and the partition wall (3). A large number of pores (7) which form the chamber (6) and penetrate the bed upper surface wall (1) and communicate with the air chamber (4) are provided, and the side wall (2) is provided with a vacuum provided outside the air chamber. Alternatively, at least two attachment ports (8) for the air pipe for connecting the air source for blow and the attachment port (9) for the heat medium pipe for connecting the heat medium chamber (6) and the external heat medium circulation device are provided. The flat bed of the flatbed offset printing machine. 2. The air chamber (4) and the heat medium chamber (6) are divided into a plurality of small chambers (4) and (6) by ribs (10) and (11), and each small chamber (4) and (6). Ribs (10) (11)
The box type bed of the flatbed offset printing machine according to claim 1, characterized in that they are communicated with each other through through holes (12) (13).