JPH0360667B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an inking device for a printing press that can be applied to offset sheet-fed printing and offset rotary printing presses.

Referring to Fig. 1, a general inking device of the delivery roller type of an offset printing machine will be explained.
Ink 2 of ink fountain 1 is applied to each ink roller 3 to 14.
is transferred to the plate cylinder 15 via. As shown in the ink roller drive system diagram shown in FIG. peripheral speed (300m
It is manufactured to rotate at a circumferential speed equivalent to ~500 m/min).

On the other hand, the ink source roller 3 rotates at a low speed (variable speed of 0 to 5 m/min) to adjust the amount of ink to be supplied. Further, the delivery roller 4 is in contact with the reciprocating roller 5 and rotates at the same circumferential speed, and maintains a gap C (0.08 to 0.1 m/m) from the ink source roller 3 as shown in FIG. Therefore, the ink source roller 3 and the delivery roller 4
During this period, the ink is only transferred and the rotations between the two rollers are separated.

Note that the transfer roller 4 can be driven by a side end gear 4G as shown in FIG. 3, or a driven (coupled) system in which it is driven by contact with the drive roller (reciprocating roller) 5 without being driven by a gear. Further, reference numeral 16 in FIG. 1 indicates a blanket cylinder, and 17 indicates an impression cylinder or blanket cylinder (in the case of an upper and lower printing unit). Furthermore, 1 in Figure 3
9, 20, and 21 are intermediate gears, and 22 is a frame.

By the way, the gap C has to be very small (it is desired to adjust it to 0.05 to 0.08 mm, but it is set to about 0.13 mm in high-speed printing machines) and must be operated constantly at a constant rate, but with the increase in speed of printing machines in recent years, Accordingly, the gap C fluctuates due to the rotational runout due to the high-speed rotation of the delivery roller 4 itself. Therefore, during operation, the ink source roller 3 and the transfer roller 4 may come into instantaneous contact, or the gap C may become larger. As a result, the following disadvantages arise.

First, in the case of contact, the inertia force caused by the high speed rotation of the transfer roller 4 momentarily causes the ink source roller 3, which rotates at a low speed, to continuously rotate to supply extra ink.
Therefore, there was a drawback that the amount of ink transfer changed, resulting in paper waste due to changes in the density of printed matter. In addition, there were cases in which abnormal noises were generated between the rollers and the rollers were deformed due to contact.

Next, when the gap C becomes large, the amount of ink supplied decreases, and the amount of ink transfer changes, resulting in paper waste due to changes in the density of printed matter. Also, when the gap C becomes smaller, the amount of ink transfer changes and waste paper similarly occurs.

Conventionally, in Japanese Patent Laid-Open No. 58-94468, a high-speed delivery roller with a rotation speed equal to that of the plate cylinder was provided with a gap of about 0.01 mm from the ink source roller, and a high-speed delivery roller was provided on the side of this delivery roller and the plate cylinder. An inking device for a printing press has been proposed in which a calling roller is disposed between this roller and a roller having the same speed.

However, in this conventional device, the gap between the ink source roller and the ink source roller fluctuates due to the rotational runout caused by the high speed rotation of the transfer roller, and the ink source roller and the transfer roller may come into contact with each other momentarily during operation, or conversely, this gap may become larger. or

First, in the case of instantaneous contact, the inertial force caused by the high-speed rotation of the transfer roller causes the ink source roller, which rotates at a low speed, to be rotated momentarily, causing a problem in which extra ink is supplied from the ink fountain. Furthermore, when the gap becomes large, the amount of ink supplied to the delivery roller decreases, resulting in a change in the amount of ink transfer, resulting in the problem of paper waste due to changes in the density of printed matter. Furthermore, when the transfer roller rotates at high speed, the centrifugal force applied to the ink itself on the transfer roller increases, resulting in disadvantages such as an increase in the amount of ink scattering.

The present invention was proposed to solve the above-mentioned conventional drawbacks, and the ink is transferred from a low-speed rotating ink source roller provided at the outlet of an ink fountain to a plate cylinder via a large number of high-speed rotating ink rollers. In the inking device of a printing press, a delivery roller rotating at medium speed is provided with a slight distance from the ink source roller, and the ink roller is placed between the delivery roller and the upstream ink roller farthest from the plate cylinder. To provide an inking device for a printing press in which the gap between the ink source roller and the delivery roller is minimized and does not fluctuate by providing a calling roller that swings into contact with each of the delivery roller and the inking roller. That is.

Embodiments of the present invention will be described below with reference to the drawings. FIGS. 4 and 5 show embodiments of the present invention,
The same parts as in FIG. 1 are indicated by the same reference numerals, and the difference between the embodiment in FIG. 4 and FIG. 1 is that a calling roller 18 is provided between the delivery roller 4 and the reciprocating roller 5. FIG. 5 is an enlarged view of the main part in FIG. 4.

Now, the rollers 5, 9, 13 in FIG. 4 are connected to the gears 5G, 9 shown in FIG. 3 attached to their side ends.
The drive rollers driven by the ink rollers G and 13G are appropriately mixed and arranged between the ink rollers 6 to 14, and the other rollers 6, 7, 8, 10, 11, 1
2 and 14 rotate in tandem as driven rollers, and these rollers have the same peripheral speed as the plate cylinder. On the other hand, the delivery roller 4 is a gear 4 shown in FIG. 3 attached to the side end.
G causes the plate cylinder to be driven at a much slower speed (temporarily 50%) than the circumferential speed of the plate cylinder. Note that an intermediate gear (not shown) is installed between the gears 4G and 5G to rotate the rollers in the forward direction.

Now, between the delivery roller 4 rotating at a medium speed and the reciprocating roller 5 rotating at a high speed, a calling roller 18 (a free rotating roller that is not driven) is making an oscillating movement, and when it comes into contact with the delivery roller 4, it is in the middle position. When it contacts the reciprocating roller 5, it rotates at high speed and transfers the ink. Here, 15 in Fig. 4 is the plate cylinder, 16
1 is a rubber cylinder, and 17 is an impression cylinder or a rubber cylinder. In addition,
Although the position of the ink fountain 1 in FIG. 1 and FIG. The rotation direction can be freely selected.

As explained in detail above, the present invention has a pick-up roller installed between the delivery roller and the roller on the downstream side near the plate cylinder, and the delivery roller has a reduced circumferential speed. It will rotate at medium speed. Therefore, it is possible to prevent defects such as fluctuation of the gap C due to roller run-out due to high-speed rotation of the delivery roller itself, which is the case in the prior art.

Generally, the pick-up roller is located between the ink source roller with a low circumferential speed and the reciprocating roller with a high circumferential speed. Especially when it comes into contact with the reciprocating roller, it requires instantaneous acceleration from low speed rotation, which causes a big shock. In addition to causing failures, this shock also had the disadvantage of increasing as the speed increased, but in the present invention, the pick-up roller is placed between the medium-speed delivery roller and the high-speed roller, so that both the medium-speed and high-speed rollers can be The difference in circumferential speed between the contacting rollers is greatly reduced compared to the prior art, and the shock is also greatly reduced. In addition, in the present invention, the circumferential speed of the delivery roller is reduced compared to the conventional one, so slippage occurs at each nip point between the delivery roller and the ink source roller, between the delivery roller and the calling roller, and between the calling roller and the downstream roller. This has the effect of smoothing the transmission of ink (due to shear fragmentation).

If the circumferential speed difference between the roller 5 and the calling roller were to be halved, 0.5=0.25 (%), and the kinetic energy (kinetic energy is proportional to the square of the speed) would be 1/4. In other words, the degree of shock is 1/4.

Therefore, according to the present invention, printing machines can be made faster than conventional structures by an amount corresponding to the reduction in the number of shots.

[Brief explanation of drawings]

Fig. 1 is a side view showing the inking device of a conventional offset printing press, Fig. 2 is an enlarged view of the same main part, Fig. 3 is a front sectional view showing the drive mechanism of the inking device, and Fig. 4 is the invention of the present invention. FIG. 5 is a side view of an inking device showing an embodiment of the present invention, and FIG. 5 is an enlarged view of the main parts thereof. Explanation of the main parts of the diagram, 1... Inkwell, 2...
Ink, 3... Ink source roller, 4... Delivery roller, 5... Reciprocating roller (roller), 4G, 5G
...gear, 15...plate cylinder.

Claims (1)

[Claims] 1. In an inking device of a printing press in which ink is transferred from a low-speed rotating ink source roller provided at the outlet of an ink fountain to a plate cylinder via a large number of high-speed rotating ink rollers, there is a slight gap between the ink source roller and the ink source roller. A delivery roller that rotates at a medium speed is installed,
An ink printing machine characterized in that a calling roller is provided between the delivery roller and an ink roller on the upstream side farthest from the plate cylinder, and which swings into contact with each of the delivery roller and the ink roller. Device.