JPH07148904A - Humidifier for offset printing press - Google Patents

Abstract

PURPOSE:To provide a humidifier for an offset printing press which can prevent the lowering of printing quality, the defective operation of the printing press, wear and the like. CONSTITUTION:A part of a water plate roller 5 is brought into contact with the water in a water plate 3, and also brought into contact with an auxiliary roller 25 and a transfer roller 7. As the auxiliary roller 25 is in contact with the water plate roller 5 by means of adjustable press force, excessive water in ink on the water plate roller 5 can be removed. The emulsification of ink on the water plate roller 5 can be prevented by the arrangement, and water can be fed to the transfer roller 7 by the required amount only to prevent the splash of water from the water plate roller 5.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a moisturizing device for an offset printing apparatus, and more particularly to proper moisturizing.

[0002]

2. Description of the Related Art In an offset printing apparatus, it is necessary to provide a plate cylinder with an appropriate amount of water according to the amount of ink used so that a high quality printed matter can be obtained. In order to provide appropriate moisture supply in this way, Japanese Patent Application Laid-Open No. 1-286856 discloses an automatic moisture supply device as shown in FIG.

The humidifying device 50 shown in FIG.
9, a water tray 3, a water tray roller 5, a transfer roller 7, and a watering roller 9. Water used for offset printing is supplied to the water tray 3, and the water tray roller 5
Is rotatably held by the support member 17, and a part thereof is in contact with the water in the water tray 3. The transfer roller 7 is in contact with the water tray roller 5 so that the water tray roller 5
It is rotatably held by the support member 17 in a state parallel to. The watering roller 9 is in parallel with the transfer roller 7 so as to come into contact with the transfer roller 7.
9 is rotatably held. The relationship between the water tray roller 5, the transfer roller 7, and the watering roller 9 is shown in the perspective view of FIG.

Each of the water tray roller 5, the transfer roller 7, and the watering roller 9 is provided with a gear (not shown) on each shaft and rotates at the same speed as the peripheral speed of the plate cylinder 11. Therefore, when the plate cylinder 11 rotates, water is supplied to the plate cylinder 11 as follows. The water tray roller 5 holds water on its surface and transfers it to the transfer roller 7. The transfer roller 7 transfers the received water to the watering roller 9. The watering roller 9 supplies the received water to the plate cylinder 11.

In the humidifying device 50, ink is supplied to the plate cylinder 11 from an ink supplying device (not shown). After printing, the ink remaining on the plate cylinder 11 is
It is also supplied to the water tray roller 5 via the transfer roller 7.

In this way, since the ink remaining on the plate cylinder 11 is also supplied to the water tray roller 5, the amount of water to be supplied is automatically determined according to the amount of ink on the plate cylinder 11. It This is because the watering roller 9 holds water on its surface according to the amount of ink supplied.

Further, since the water tray roller 5 rotates in conjunction with the peripheral speed of the plate cylinder 11, when the peripheral speed of the plate cylinder 11 increases (when the printing speed increases), a larger amount of the peripheral speed is produced. Water is supplied to the plate cylinder 11. Therefore, the amount of water supplied is automatically adjusted.

[0008]

However, the humidifying device 50 has the following problems. Ink is supplied to the water tray roller 5 via the plate cylinder 11, the watering roller 9, and the transfer roller 7, and water is supplied to the plate cylinder 11 in the reverse order. When the dampening water is too much on the plate cylinder 11, the ink held on the plate cylinder 11 is emulsified. As a result, the water supply to the plate cylinder 11 becomes unstable, and the printed matter becomes soiled.

In addition, such emulsified ink spreads to both ends of the water tray roller 5 and accumulates so as to wrap around the side surfaces of the both ends to form irregularities. As the ink accumulation progresses, the unevenness increases, and the accumulated ink portion 6 is formed as shown in FIGS. 7A and 7B. The portion where the accumulated ink portion 6 is formed is also in contact with the water 8 stored in the water tray 3. Therefore, the water tray roller 5
When is rotated, the accumulated ink portion 6 causes the water stored in the water tray 3 to be scattered outside the water tray 3. 7A is a sectional view taken along line XX of FIG. 7B.

If water splashes on the printed matter, the density of the printed matter will be reduced, and if it splashes on the mechanical portion of the printing apparatus, problems such as malfunction and wear due to rusting and burning of parts occur.

In order to prevent such water splash, the water tray roller 5 has a longer axial length than the other rollers, as shown in FIG. In this way, by making the length of the water tray roller 5 in the axial direction longer than the other rollers, the ink that has spread to both ends of the water tray roller 5 is
Accumulating in the axial direction rather than the radial direction (that is, the thickness direction). Therefore, it is possible to slightly delay the time until the shape of the accumulated ink becomes an uneven shape that causes water splashing.

However, even in this case, it is possible to delay the time until the water splashes, and eventually,
Water splashes.

The present invention solves the above-mentioned problems and prevents deterioration of printing quality even after printing for a long time, and at the same time, provides an offset printing apparatus capable of preventing malfunction or wear of the printing apparatus. The purpose is to provide a humidifying device.

[0014]

According to a first aspect of the present invention, there is provided a moisturizing device for an offset printing apparatus, wherein a moisturizing liquid is stored and a part of the moisturizing liquid is stored in the moisturizing liquid. A first roller rotatably held, a roller indirectly receiving the dampening liquid held on the surface of the first roller and supplying it to the plate cylinder, and a second roller rotatably held. A moisturizing device for an offset printing apparatus including a roller is provided with an auxiliary roller that abuts against the first roller and is held so as to rotate together with the first roller.

According to another aspect of the present invention, there is provided a moisturizing device for an offset printing apparatus, comprising a pressing force adjusting mechanism for adjusting a pressing force for pressing the auxiliary roller against the first roller.

According to another aspect of the present invention, there is provided a moisturizing device for an offset printing apparatus, wherein the auxiliary roller is made of a material to which ink easily adheres, and has a hardness difference from the first roller. And

[0017]

In the moisturizing device for an offset printing apparatus according to claim 1, since the auxiliary roller is in contact with the first roller, when the auxiliary roller rotates together with the first roller, Discard excess water on roller 1. Therefore, emulsification of the ink on the first roller can be prevented. This stabilizes the supply of water on the plate cylinder. Further, it is possible to prevent the dampening liquid stored in the dampening liquid reservoir from scattering outside the dampening liquid reservoir.

In the moisturizing device of the offset printing apparatus according to the second aspect, the pressing force adjusting mechanism adjusts the pressing force for pressing the auxiliary roller against the first roller. Therefore, the pressing force that presses the auxiliary roller against the first roller can be easily adjusted. By adjusting the pressing force, the size of the flat surface formed near the contact surface of the first roller or the auxiliary roller can be adjusted. This makes it possible to adjust the supply amount of the dampening liquid to the plate cylinder.

In the moisturizing device for an offset printing apparatus according to a third aspect of the present invention, the auxiliary roller is made of a material to which ink easily adheres. Since the dampening liquid is held on the surface of the auxiliary roller according to the amount of the attached ink, more dampening liquid can be held. Furthermore, since a hardness difference is provided between the auxiliary roller and the first roller, when a roller with a low hardness is pressed by a roller with a high hardness, the roller with a low hardness is flattened near both contact surfaces. Is formed. Thereby, excess water on the first roller can be removed.

[0020]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described with reference to the drawings. The humidifier 1 is shown in FIG. The moisturizing device 1 is provided with a water tray 3 which is a dampening liquid reservoir, a water tray roller 5 which is a first roller, a transfer roller 7, a watering roller 9 which is a second roller, and an auxiliary roller 25. .

The water tray 3 is attached to the frame 19 with screws or the like, and stores water as a moisturizing liquid. The water in the water tray 3 is supplied from the water tank 27.

The water tray roller 5 has the same support member 1 as the conventional one.
It is rotatably held by 7, and a part of it is in contact with the water in the water tray 3. Since the auxiliary roller 25 is rotatably held by the support member 17 and is in contact with the water tray roller 5 and is provided in a rotatable position, when the water tray roller 5 rotates clockwise, the auxiliary roller 25 is assisted. The roller 25 rotates counterclockwise.

Since the transfer roller 7 and the watering roller 9 are the same as the conventional ones, their explanations are omitted.

In the moisturizing device 1, ink is applied to the plate cylinder 11 from an ink roller (not shown) and water is applied from the moisturizing device to print on the printing paper. The water supplied from the humidifying device is sequentially transferred to the water tray roller 5, the transfer roller 7, and the watering roller 9 and supplied to the plate cylinder 11 as in the conventional case. As described above, in this embodiment, the watering roller 9 transfers the water held on the surface of the water tray roller 5 through the transfer roller 7 to the water.
It is indirectly received and supplied to the plate cylinder 11.

The ink and water remaining on the plate cylinder 11 are transferred to the watering roller 9. The vibration roller 8 is in contact with the watering roller 9. The vibration roller 8 makes the ink and water coatings on the watering roller 9 uniform and makes the ink and water rough.

The ink and water on the watering roller 9 come into contact with the vibration roller 8, and then are transferred by the transfer roller 7 and further transferred to the water tray roller 5. The ink and water on the water tray roller 5 come into contact with the auxiliary roller 25 before coming into contact with the water in the water tray 3. Since the auxiliary roller 25 is in contact with the water tray roller 5, excess water can be removed from the ink on the water tray roller 5.
Therefore, the emulsification of the ink on the water tray roller 5 can be prevented. As a result, it is possible to prevent ink from accumulating on both ends of the water tray roller 5 and forming irregularities (see FIG. 7). Therefore, it is possible to prevent the water stored in the water receiving tray 3 from scattering outside the water receiving tray 3.

Further, in this embodiment, the auxiliary roller 2
5, the emulsification of the ink on the water tray roller 5 can be prevented. As a result, the effect of stabilizing the supply of water to the plate cylinder 11 and preventing the quality of the printed matter from decreasing is also obtained. This is for the following reasons.

Generally, when the emulsified ink is accumulated in the water tray 3, there arises a problem that the retention of water on the water tray roller 5 is hindered. However, in the present embodiment, since it is possible to prevent the ink from being emulsified, the emulsified ink does not collect in the water tray 3, and water is stably supplied from the water tray roller 5 to the watering roller 9. Because. By the way, if the rubber of the auxiliary roller 25 is soft, excess water cannot be removed from the water held in the ink to the extent that emulsification can be prevented. Therefore, the hardness of the auxiliary roller 25 is preferably high to some extent so that excess water can be removed to the extent that the water in the ink held on the surface of the water tray roller 5 can be prevented from being emulsified. In this embodiment, the auxiliary roller 25 has a rubber hardness higher than that of the water tray roller 5. By thus forming the auxiliary roller 25 with a material harder than the water tray roller 5, a flat surface is formed in the water tray roller 5 near the contact surface with the auxiliary roller 25. The amount of water supplied to the plate cylinder 11 changes depending on the size of the flat surface. That is, the amount of water supplied can be changed depending on the hardness difference between the two.

Regarding the hardness of the auxiliary roller 25,
The rubber hardness is preferably 40 degrees or more, and more preferably 40 to 60. Most preferred is a rubber hardness of 50.

Further, in the present embodiment, the auxiliary roller 2
Although the material of No. 5 is made of rubber (NBR), a rilsun roller coated with rilsun resin may be used. Alternatively, ebonite, metal plated with copper, or the like may be used.

Next, the pressing force adjusting function of the auxiliary roller 25 will be described with reference to FIGS. 2 to 4A. Note that FIG.
3A is a detailed view around the auxiliary roller 25 in FIG.
2A is a cross-sectional view taken along line I-I in FIG. 2A, and FIG. 4A is a cross-sectional view taken along line II-II in FIG.

As shown in FIGS. 2A and 3, the frame 19
A bracket 45 is provided on the. Bracket 4
5 has a groove 45a, and the line I- of the bracket 45
The I cross section is U-shaped as shown in FIG.

A bearing 33 is provided on the shaft of the auxiliary roller 25.
Is installed. The bearing 33 is fitted in the groove 45a as shown in FIG. 4A. Therefore, the auxiliary roller 25 is rotatably held by the bracket 45. Further, the auxiliary roller 25 is movable in the β direction of the groove 45a shown in FIG. 2A.

An arm 47 is attached to the bracket 45 with a screw 4
It is screwed at 9. The arm 47 is provided with a screw hole, and the pressing force adjusting screw 3 is provided in the screw hole.
1 is screwed. Pressing force adjusting screw 3 shown in FIG. 4A
The protrusion amount α of the No. 1 from the arm 47 is determined by adjusting the nut 36.

That is, after the bearing 33 attached to the auxiliary roller 25 is moved in the β direction along the groove 45a and brought into contact with the water tray roller 5 at a desired roller pressure,
(After determining the protrusion amount α shown in FIG. 2A), the nut 36
Tighten up. This makes it possible to adjust the pressing force with which the auxiliary roller 25 contacts the water tray roller 5.

By adjusting the pressing force in this way, the size of the flat surface formed near the contact surface between the water tray roller 5 and the auxiliary roller 25 can be adjusted. As a result, the amount of water supplied to the plate cylinder 11 can be adjusted, so that the ink on the water tray roller 5 can be prevented from being emulsified.

In the present embodiment, the auxiliary roller 2
Since the pressing force adjustment function of No. 5 is provided, the pressing force adjustment can be easily performed while printing.

[Other Application Examples] In this embodiment, water was used as the dampening liquid, but any dampening liquid that emulsifies in relation to the ink may be used. it can.

In the present embodiment, the mechanism shown in FIGS. 2 to 4A is adopted as the pressing force adjusting mechanism, but any mechanism capable of adjusting the pressing force for pressing the auxiliary roller 25 against the water tray roller 5 can be used. It can be anything.

In the present embodiment, the auxiliary roller 2
5 is made of a material having a hardness higher than that of the water tray roller 5,
It suffices that the materials of the auxiliary roller 25 and the water tray roller 5 have a hardness difference, and the auxiliary roller 25 may be made of a material softer than the water tray roller 5.

Especially when a pressing force adjusting mechanism is provided,
Excluding excess water on the water tray roller 5 by adjusting the pressing force for pressing the auxiliary roller 25 against the water tray roller 5 according to the hardness difference between the materials of the auxiliary roller 25 and the water tray roller 5. You can

A compression spring 32 may be provided between the bearing 33 and the arm 47 as shown in FIG. 4B. This makes it easier to finely adjust the pressing force. Further, two adjusting mechanisms provided at both ends may be interlocked.

Further, in this embodiment, the auxiliary roller 2
5 is arranged at a position higher than the water tray roller 5 so as to face the transfer roller 7. However, the present invention is not limited to this, and the water tray roller 5 may be arranged in any position as long as the water tray roller 5 comes into contact with the water before contacting the water in the water tray 3. By arranging in such a position, the blending degree of water with respect to the ink can be made appropriate.

The auxiliary roller 25 may be arranged at a position where the water tray roller 5 comes into contact with the water in the water tray 3 and then comes into contact therewith, for example, a position as shown in FIG. 2B.

[0045]

According to the first aspect of the present invention, there is provided a moisturizing device for an offset printing apparatus, which comprises an auxiliary roller which is in contact with the first roller and is held so as to rotate together with the first roller. Therefore, it is possible to prevent the dampening liquid from scattering outside the dampening liquid reservoir due to the emulsification of the ink on the first roller. As a result, it is possible to provide a moisturizing device for an offset printing apparatus, which can prevent the printing quality from deteriorating even when printing is performed for a long time, and can prevent malfunction of the printing apparatus, wear, and the like.

According to another aspect of the present invention, there is provided a moisturizing device for an offset printing apparatus, comprising a pressing force adjusting mechanism for adjusting a pressing force for pressing the auxiliary roller against the first roller. Therefore, the pressing force that presses the auxiliary roller against the first roller can be easily adjusted. By adjusting the pressing force, the size of the flat surface formed near the contact surface of the first roller or the auxiliary roller can be adjusted. As a result, the amount of the dampening liquid supplied to the plate cylinder can be adjusted, so that the emulsification of the ink on the first roller can be prevented more easily. That is, it is possible to provide a moisturizing device for an offset printing apparatus, which can prevent the printing quality from deteriorating even after printing for a long time, and can prevent malfunction of the printing apparatus and abrasion.

In the moisturizing device for an offset printing apparatus according to a third aspect of the present invention, the auxiliary roller is made of a material to which ink easily adheres. Since the dampening liquid is held on the surface of the auxiliary roller according to the amount of the attached ink, more dampening liquid can be held. Furthermore, since a hardness difference is provided between the auxiliary roller and the first roller, when a roller with a low hardness is pressed by a roller with a high hardness, the roller with a low hardness is flattened near both contact surfaces. Is formed. As a result, excess water on the first roller can be removed, so that emulsification of the ink on the first roller can be prevented more easily.
That is, it is possible to provide a moisturizing device for an offset printing apparatus, which can prevent the printing quality from deteriorating even after printing for a long time, and can prevent malfunction of the printing apparatus and abrasion.

[Brief description of drawings]

FIG. 1 is a diagram showing a printing apparatus including a humidifying device 1 according to an embodiment of the present invention.

FIG. 2A is a diagram showing a main part of a humidifier 1 according to an embodiment of the present invention, and FIG. 2B is an auxiliary roller 25.
It is a figure which shows the example which has arrange | positioned in another position.

3 is a cross-sectional view taken along the line I-I of FIG.

FIG. 4 is a sectional view taken along the line II-II in FIG.

FIG. 5 is a diagram showing a printing apparatus including a conventional moisture supply device 50.

FIG. 6 is a perspective view showing each roller in a conventional humidifier.

FIG. 7 is a diagram showing an ink accumulation state in a conventional humidifier.

[Explanation of symbols]

 3 ... Water tray 5 ... Water tray roller 7 ... Transfer roller 9 ... Watering roller 25 ... Auxiliary roller

Claims (3)

[Claims] 1. A dampening liquid reservoir for accumulating a dampening liquid, a first roller which is rotatably held while partly contacting the dampening liquid in the dampening liquid reservoir, and a surface of the first roller. A roller for indirectly receiving the dampening fluid held by the roller and supplying the dampening fluid to the plate cylinder, the roller being rotatably held by the second roller; A humidifying device for an offset printing apparatus, comprising: an auxiliary roller that is in contact with a roller and is held so as to rotate together with the first roller. 2. The moisturizing device for an offset printing apparatus according to claim 1, further comprising a pressing force adjusting mechanism for adjusting a pressing force for pressing the auxiliary roller against the first roller. 3. The auxiliary roller is made of a material to which ink easily adheres, and is provided with a hardness difference from the first roller, wherein the auxiliary roller has a hardness difference from that of the first roller. Moisture supply device of the offset printing apparatus described.