JPH0325963Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Field of Application] The present invention relates to a printing device, and more particularly to a cooling roller that cools printing paper printed by an offset printing machine and heated and dried to room temperature.

In the case of normal offset, the printing paper is
The printing paper is heated and dried in a dryer, but the temperature of the printing paper that comes out of this dryer is 120° to 130°, and the printing ink has not yet fully cured, so it must be dried as quickly as possible in order to move on to the next process. It needs to be cooled to room temperature.

Therefore, conventionally, as shown in FIG. 1, the cooling roller 1 is composed of a cylindrical drum 2 and a shaft 3 that rotatably supports the drum 2. This drum 2 is a drum around which the printing press 4 is wound. Side 5
A cylindrical outer cylinder 5a forming a cylindrical outer cylinder 5a, an inner cylinder 5b coaxially and spaced apart inside this outer cylinder, and this outer cylinder 5
a and an end plate 5c that supports the inner cylinder 5b, and a partition wall 8 that spirally partitions a cooling water circulation space 6 between the outer cylinder 5a and the inner cylinder 5b, and a partition wall 8 that spirally partitions a cooling water circulation space 6 between the outer cylinder 5a and the inner cylinder 5b. Therefore, the structure was such that the roller surface 5 was cooled from the back side.

This known cooling roller 1 has a structure in which the space 6 flows from one end of the roller surface 5 to the other, so that the entire surface of the roller surface 5 is cooled. Moreover, this roller surface 5 is usually made longer than the width of the printing press around which it is wound. Therefore, the roller surface 5
Even if the printing paper 4 is wrapped around the printing paper 4, there will be a portion at the end where the printing paper does not come into contact, and this portion will condense as it cools. Water droplets generated by this condensation gradually accumulate to form a layer of water.

This water at the end of the roller surface 5 interferes with the printing operation by wetting the printing paper 4 and causing paper breakage when the printing press starts operating, and also splashes around while the printing press is running, staining the printing paper. This causes inconveniences such as degrading the quality of the product and staining the area around the cooling roller.

The above dew condensation can be prevented by making the length of the roller surface 5 match the width of the printing paper 4, but the width of the printing paper must be changed depending on the printing purpose, and a dedicated cooling device is required for each paper width. Providing rollers is practically impossible because the economic burden would be too large.

[Purpose of invention]

Therefore, the purpose of this invention is to eliminate the above-mentioned drawbacks and provide a cooling roller for a printing press that can cool printing paper of various paper widths without changing the length of the roller surface or causing dew condensation on the roller surface. do.

[Summary of the idea]

The object is to consist of a drum and a shaft that rotates this drum, the peripheral surface of the drum forms a roller surface around which printing paper is wound, and a cooling water circulation space is provided inside this roller surface for flowing cooling water. ,
This axial length of the cooling water circulation space is achieved by the cooling roller approximately equal to the minimum width of the printing paper wound around the roller surface.

〔Example〕

Hereinafter, embodiments of the present invention will be described with reference to the drawings.

FIG. 2 is a longitudinal sectional view of the cooling roller 10 based on the present invention. In this figure, the cooling roller 10 consists of a drum 11 for cooling printing paper and a shaft 3 that rotatably supports the drum 11.

The drum 11 includes a cylindrical outer cylinder 12 forming a roller surface 5 around which the printing paper 4 is wound, and a cylindrical inner cylinder 13 coaxially and spaced apart from the outer cylinder 12 inside the outer cylinder 12. and an end plate 14 that supports both sides of the outer cylinder 12 and the inner cylinder.

Inside the gap between the outer cylinder 12 and the inner cylinder 13, partition walls 15 and 16 are watertightly spaced apart so as to go around the gap in a direction perpendicular to the axis.
5 and 16 is approximately equal to the minimum paper width W ₂ of the printing paper 4. Preferably, the partition walls 15 and 16 are positioned at equal distances from the center of the roller surface 5. the outer cylinder 12, the inner cylinder 13, and the partition wall 15,
A cooling water circulation space 17 is formed by 16 .

A cooling water supply system 18 is connected to one end of the space 17, and a cooling water discharge system 19 is connected to the opposite end. Further, a partition wall 20 is provided in a spiral shape from an inner end of the space 17 to the opposite end, and this partition wall 20 guides the cooling water flowing inside the space 17.

[Effect]

The cooling roller 10 according to the present invention operates as follows.

The space 17 receives cooling water supplied from the cooling water supply system 18 from one end thereof, and allows the cooling water to flow through the space 17 along a spiral path through the partition wall 20, so that the rollers can be cooled. Directly cooling the range from the partition wall 15 to the partition wall 16 on the back surface of the surface 5,
Thereafter, the cooling water is discharged from the opposite end of the space 17 to a drainage channel (not shown) outside the cooling roller 10 via a cooling water discharge system 19.

The cooling roller 10 rotates synchronously with a printing machine (not shown). The printed paper printed by the printing machine and heated and dried at 120° to 130° in a dryer (not shown) is wrapped around the directly cooled portion of the roller surface 5, and while the drum 11 rotates at a predetermined angle. Then, it is cooled by the roller surface 5 and transferred to the next step. The roller surface 5 rotates to the initial position while being cooled, and the uncooled printing paper is wound around it.

Since the width W ₂ of the space 17 of the cooling roller 10 is almost the same as the minimum paper width of the printing paper 4 as described above, the printing paper 4 is in the area directly cooled by the cooling water on the roller surface 5. Since it is always wrapped around and in contact to provide heat, no condensation occurs.

When the paper width of the printing paper 4 is wider than the minimum paper width W ₂ , the side edge of the printing paper is wrapped around the part of the roller surface 5 that is not directly cooled by the cooling water, but this part is not directly cooled by the heat transfer of the outer cylinder 12. Since the side edges of the printing paper 4 are easily cooled, the cooling is carried out without any problem, and the portion of the roller surface that is indirectly cooled is cooled by the cooling water on the roller surface 5. Since the temperature does not drop as much as in the parts that are directly cooled by the water, condensation does not occur. In this way, printing paper ranging from the minimum paper width to the maximum paper width can be cooled without causing dew condensation on the roller surface. Further, since the roller surface 5 is not cooled to the outermost end unlike the conventional cooling roller 1, dew condensation on the mirror plate of the drum 11 is also prevented.

〔effect〕

By using the cooling roller based on the present invention, it is possible to prevent dew condensation on the roller surface, thereby completely preventing the possibility of the printing paper being broken at the start of printing press operation, the printing paper being soiled due to water droplets flying during printing press operation, and the risk of staining the area around the cooling roller. be able to. Further, the required amount of cooling water can be reduced by reducing the area due to the shortening of the cooling water circulation space, and it is also possible to prevent undesirable dew condensation from forming on surfaces other than the roller surface, such as the end plate.

[Brief explanation of drawings]

FIG. 1 is a longitudinal sectional view of a conventional cooling roller, and FIG. 2 is a longitudinal sectional view of a cooling roller based on the present invention. 1... Conventional cooling roller, 2, 11... Drum, 3... Shaft, 4... Printing paper, 5... Roller surface, 5a, 12... Outer cylinder, 5b, 13... Inner cylinder, 5c, 14... End plate, 6, 17... Cooling water circulation space, 7... Print paper non-contact portion, 10... Cooling roller based on the present invention, 15, 16... Partition wall, 18
...Cooling water supply system, 19...Cooling water discharge system,
20...Partition wall, _W1 ...Maximum paper width, _W2 ...Minimum paper width.

Claims (1)

[Scope of utility model registration request] Consisting of a drum and a shaft that rotates this drum, the peripheral surface of the drum forms a roller surface around which printing paper is wound, and a cooling water circulation space is provided inside this roller surface to allow cooling water to flow. A cooling roller for a printing press, wherein the length of the circulation space in the axial direction is approximately equal to the minimum width of printing paper wrapped around the roller surface.