JPS6313006Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a printing position adjustment device for an offset printing press.

Figure 1 shows an example of an offset printing press, in which reference numeral 1 indicates a side plate of the printing press, 2 indicates a plate cylinder, 3 indicates a transfer cylinder, 4 indicates an impression cylinder, and 5 indicates a vertically movable paper feeder. 6 is a printing paper stacked on the paper feed tray, 7 is a paper feed roller that feeds the printing paper one sheet at a time, and 8 is a printing paper placed between the paper feed tray 5 and the impression cylinder 4. A number of paper guide members 9 are arranged in the axial direction on a part of the circumferential surface of the impression cylinder 4, and include well-known holding claws 10 that have the function of gripping the front edge of the printing paper fed by the paper feed roller 7. is transfer cylinder 3
The receiving trays for printed paper printed while passing between the roller and the impression cylinder 4 are shown.

In such an offset printing machine, when printing, the printing position in the horizontal direction of the printing paper is adjusted, for example, on a paper feed table on which the printing paper is placed, and then the printing position is adjusted in the longitudinal direction (back and forth direction) of the printing paper. The printing position is adjusted by appropriately changing the relative position of the impression cylinder in the rotational direction with respect to the transfer cylinder.

FIG. 1 shows an example of an offset printing machine equipped with a device for adjusting the printing position in the vertical direction. In explaining the present invention, this offset printing machine will first be described.

As shown in FIG. 2, on one end surface of the transfer cylinder 3 of the three printing cylinders, there is an impression cylinder 4, which is another printing cylinder.
A transmission gear 11 meshing with a gear (not shown) provided on an end surface of the transfer cylinder 3 is provided on the other end surface of the transfer cylinder 3 so that the transmission gear 11 can rotate relative to the transfer cylinder 3. Gear 13 fixed with screw 12
are attached to each. The fixed gear 13 meshes with a gear (not shown) provided on the end face of the plate cylinder 2, so that the three printing cylinders (plate cylinder 2, transfer cylinder 3, and impression cylinder 4) are mutually connected. They are connected by gears, and each rotates in the direction of the arrow shown in FIG.

In FIG. 2, a small diameter gear 15 rotatably provided on the shaft 14 of the transfer cylinder 3 includes a gear 16 mounted on a fixed position on the side plate 1, and an intermediate gear mounted on a movable arm 17. 18 are engaged with each other, and a planetary gear 19 is mounted on the movable arm 17.
meshes with the intermediate gear 18 and the fixed gear 13 at the same time. The movable arm 17 is loosely fitted around the outer periphery of a bearing 20 that is firmly attached to the side plate 1, and teeth 17a that mesh with the worm 21 are provided on the arcuate edge of the movable arm 17 centered on the shaft 14. ing. The worm 21 is mounted on a side plate, and an operating knob 23 is provided at the outer end of the shaft 22, as shown in FIG.

The gear 16 includes one gear 25 of a pair of gears 25 and 26 fixed to the drive shaft 24, and the transmission gear 11 rotatably provided with respect to the transfer cylinder 3 includes the other gear 26. are interlocked with each other. Therefore, when the drive shaft 24 is rotated in the direction of the arrow in FIG.
9 in the direction of arrow a, while the transmission gear 11 meshing with the gear 26 on the drive shaft 24 also rotates in the same direction and at the same speed as the transfer cylinder 3;
The rotation of the transmission gear 11 is transmitted to the impression cylinder, and the rotation of the fixed gear 13 is transmitted to the plate cylinder at the same speed.

Now, assuming that each printing cylinder is stationary, rotate the operating knob 23, rotate the movable arm 17 using the worm 21, and move the planetary gear 19 mounted on the movable arm 17 to the first position. When the gear 18 is rolled around the fixed gear 13 to the position shown by the dotted line 19A in FIG.
Rotated in the direction of the arrow by the planetary gear 19,
The rotation of this gear 18 is transmitted to the transmission gear 11 via the small diameter gear 15, gear 25, and gear 26,
Furthermore, since the rotation of the transmission gear 11 rotates the impression cylinder, the impression cylinder is rotated with respect to the stationary transfer cylinder 3, and therefore the relative position of the transfer cylinder 3 and the impression cylinder in the rotational direction changes. . In this case, the amount of deviation in the rotational direction between the transfer cylinder 3 and the impression cylinder is
3 and the small diameter gear 15, and the larger the difference in diameter between the two, the larger the above-mentioned deviation amount becomes.

The change in the relative position of the impression cylinder 4 with respect to the transfer cylinder 3 as described above means that the position of the printing paper holding claw 9 provided on the impression cylinder 4 changes with respect to the transfer cylinder 3. Therefore, the relative position between the original wrapped around the plate cylinder 2 that cooperates with the transfer cylinder 3 and the printing paper held by the holding claws 9 changes in the front-rear direction (vertical direction of the printing paper and the original). death,
At this time, the printing position of the original plate relative to the printing paper is adjusted. Although the above position adjustment is performed with the transfer cylinders stationary, it is of course possible to perform the position adjustment with each printing cylinder rotated, that is, with the printing press in operation.

In such an offset printing press, when printing, the driving force from the drive system is used to rotate one printing cylinder, for example, a transfer cylinder, at a speed necessary for printing, using a planetary gear mechanism, and adjust the printing position. When printing, the impression cylinder is rotated relative to the transfer cylinder using the function of a planetary gear mechanism, but due to the use of such a planetary gear mechanism, the printed image It has the disadvantage of causing slight misalignment.

As shown in FIG. 2, the drive system is affected by the frictional force between the movable arm 17 and the bearing 20, the backlash of the gears in the planetary gear mechanism, the frictional force of these gears against the support shaft, etc. This is because the load on the driven system side fluctuates, making it impossible for the transfer cylinder to always rotate at a constant angular velocity. For example, as shown in FIG. 1, a certain point A on the transfer cylinder 3 and a certain point B on the impression cylinder 4 do not coincide with each other every rotation of each cylinder, and there is a slight deviation between them. This means that the images of the printed materials that are printed will be shifted from one printed material to another.

SUMMARY OF THE INVENTION An object of the present invention is to provide an improved printing position adjustment device for an offset printing press that eliminates the drawbacks of the conventional device.

FIG. 4 shows a sectional structural view of an improved printing position adjusting device according to an embodiment of the present invention, and the planetary gear mechanism on the left side of the device is no different from the conventional device. Another feature is that a clutch mechanism is installed on the right side of the device.

In the apparatus of this embodiment, an electromagnetic clutch designated by the reference numeral 30 is used as the clutch mechanism.
2 and an electromagnet 33. The armature 31 is fitted onto the shaft 14 and screwed to a transmission gear 34 that is rotatable with respect to the transfer cylinder 3.
The two are essentially one. Further, the rotor 32 is substantially integrated with the shaft 14 by a key 35. On the other hand, an impression cylinder 4, which is another printing cylinder with respect to the transfer cylinder 3, is supported by a shaft 37 via a bearing 38, and a driven gear 36 is fixed to the end of the impression cylinder 4. , this driven gear 36 meshes with the transmission gear 34.

Now, assuming that the offset printing machine is in actual operation, in other words, the printing paper is being fed and the printing paper is being printed, in this case, the fourth
The electromagnetic clutch 30 shown in the figure is energized, the armature 31 and the rotor 32 are integrated, and the clutch function is in a connected state, and the shaft 14 and the transmission gear 3 are connected.
It becomes one with 4.

Therefore, the rotation of the drive shaft 24 is transmitted to the shaft 1 through the gear 26, the transmission gear 34, and the electromagnetic clutch 30.
The rotation of the transmission gear 34 is transmitted to the impression cylinder 4 via a driven gear 36 which meshes with the transmission gear 34, and the transfer cylinder 3 rotates in the direction of the arrow in Fig. 1. On the other hand, the rotation of the transmission gear 34 is transmitted to the impression cylinder 4 via a driven gear 36 which meshes with the transmission gear 34, and the impression cylinder 4 rotates in the direction of the arrow in Fig. 1. In other words, both cylinders 3, 4 rotate synchronously with each other.

On the other hand, the rotation of the gear 25 is transmitted to the transfer cylinder 3 via a planetary gear mechanism including a gear 16, a small diameter gear 15, an intermediate gear 18, a planetary gear 19, a fixed gear 13, etc.
However, the driving force from the drive shaft 24, which is a drive system, is substantially transmitted by a power transmission system passing through an electromagnetic clutch.

Next, when adjusting the printing position while each printing cylinder is rotating, the electromagnetic clutch 30 is de-energized, and the transmission gear 34 and shaft 14 are accordingly released. The state of direct connection with is canceled. Therefore, the mechanical configuration is similar to that of the conventional device shown in FIG. 2, and by rotating the worm 21, the planetary gear mechanism, the gear 25, the drive shaft 24,
The impression cylinder 4 is rotated relative to the transfer cylinder 3 via the gear 26, the transmission gear 34, and the driven gear 36, and the printing position is adjusted.

On the other hand, normal rotation of the transfer cylinder 3 by the drive shaft 24 is performed via a planetary gear mechanism, and normal rotation of the impression cylinder 4 is performed via a transmission gear 34 and a driven gear 36. In addition, electromagnetic clutch 3
An example of a control means for turning on and off 0 is a means that turns on an electromagnetic clutch when a printing paper feed signal is issued, and turns off the electromagnetic clutch when the signal is not issued. In addition, in the embodiment of the present invention, an electromagnetic clutch is used as the clutch mechanism, but
In short, any device may be used as long as it can connect and disconnect the power transmission relationship between the transmission gear and the transfer cylinder.

In this way, according to the present invention, when printing paper is being printed, power is transmitted to the printing cylinder directly by the transmission gear, driven gear, clutch mechanism, etc., rather than through the planetary gear mechanism. Since the printing is carried out in a consistent manner, there is no occurrence of print image shift due to load fluctuations, which is a drawback of conventional apparatuses, and it is possible to obtain printed matter without variations in the position of the print images. Further, when the present invention is applied to a multicolor printing press, there is no fear of color misregistration. In addition, in this invention, the present applicant has already applied for the Utility Application No.
It can also be applied to the offset printing machine described in No. 37130 (Utility Model Publication No. 56-139549), and it is not a three-cylinder offset printing machine, but instead transfers the image directly from the original plate to the printing paper. It is also applicable to a two-cylinder printing press.

[Brief explanation of the drawing]

FIG. 1 is a side view showing an example of an offset printing machine, FIG. 2 is a sectional view of a conventional printing position adjustment device provided in the offset printing machine, and FIG. 3 is a side view showing an example of an offset printing machine.
FIG. 4 is a cross-sectional view of a printing position adjusting device for an offset printing press according to an embodiment of the present invention. 3...first printing cylinder, 4...second printing cylinder, 13...
...Fixed gear, 15...Small diameter gear, 16...Gear,
17...Movable arm, 18...Intermediate gear, 19...Planetary gear, 24, 25, 26...Drive system, 30...
An electromagnetic clutch as a clutch mechanism, 34...transmission gear, 36...driven gear.

Claims (1)

[Scope of utility model registration request] A device for adjusting a printing position by changing the relative rotational position of one first printing cylinder and another second printing cylinder, the transmission gear being rotatably provided with respect to the first printing cylinder; A driven gear that is fixed to the second printing cylinder and meshes with the transmission gear, a drive system that drives the transmission gear, and a drive system that is driven by an external drive operation to perform planetary motion.
a planetary gear mechanism for rotating a second printing cylinder relative to the printing cylinder via the transmission gear and the driven gear; and a planetary gear mechanism for connecting the transmission gear to the first printing cylinder when printing paper is being printed. 1. A printing position adjusting device for an offset printing press, comprising: a clutch mechanism for releasing the direct coupling operation when adjusting the printing position.