JP3112149B2 - Switchable sheet-fed printing press condition monitoring device - Google Patents

Abstract

The condition monitor detects the angular setting of the printing machine both before and after the sheet turning point in the sheet transport direction, with the difference between the detected angular settings compared with a required difference value, to allow the operation of the printing machine to be interrupted. Pref. the angular settings of the printing machine both before and after the sheet turning point in the sheet transport direction, with the difference between the detected angular settings compared with a required difference value, to allow the operation of the printing machine to be interrupted. Pref. the angular settings of the printing machine are detected in digital format each time the printing machine is brought to a standstill, with comparison of the difference with the required difference value before the printing machine is brought back into operation.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for monitoring the condition of a switchable sheet-fed printing press.

Switchable sheet-fed printing presses which operate in the form of sheet trailing edge reversal are known and can be used selectively in single-sided or double-sided printing modes. Switching from a single-sided printing mode to a double-sided printing mode in this type of printing press means the following. This means that the part of the printing press following the reversing device has to be adjusted and moved with respect to the part of the printing press before the reversing device according to the format of the material to be printed. This type of printing press therefore has a clutch device and a reversing device, with which the switching of the operating mode can be carried out. The reversal process described above is shown in DE 35 26 123 A1. In addition to the format-dependent rotation of the printing unit after the reversal, further component units used for the reversal need to be switched depending on the format.
This is also indicated in the publications mentioned above.

[0003] Sheet-fed printing presses capable of switching from single-sided printing to double-sided printing have to maintain a format-dependent setting (setting adjustment) at all times, since they have a detachable and possible clutch in the main drive. is there. In the case of this type of printing press, a clutch which normally acts in a frictional connection is used. This clutch allows for arbitrary formatting. When operating improperly or when contaminated, the clutch may slip. Slip in the clutch of a switchable sheet-fed printing press can cause significant press damage during printing, which can create operator danger.

[0004] EP 0 243 700 B1 shows a device for protecting a rotary printing press. This protection device monitors, via mechanical means, the clamped state of the clutch of the switchable reversing device (closing connection). Due to the large number of components to be additionally provided, this solution is very costly.

[0005]

The object of the invention is to provide a device for monitoring the state of a switchable sheet-fed printing press, which is described in the preamble of the device claim.
An improvement is made to allow for an accurate inspection of the normal working condition.

[0006]

SUMMARY OF THE INVENTION The object is to provide a printing press in which first and second angle transmitters are mounted in front of and behind a switchable reversing device, these angle transmitters being connected to a calculator. With this angle transmitter, the difference formation of the supplied angle values is performed, and the calculator is configured as follows: the difference of the supplied angle values is calculated from a predetermined target value. Is configured to stop the main drive of the printing press when a deviation is detected, a positioning drive is operatively connected to the calculator, and the second positioning drive is used to The problem is solved in that, in cooperation with the angle transmitter, a switch from single-sided printing to double-sided printing and vice versa is performed. Advantageous developments of the invention are set out in the dependent claims.

According to the invention, values corresponding to the angular position of the printing press are detected by means of a switchable reversing device and these values are compared with one another taking into account the format-dependent angle differences in the operating type duplex printing. evaluate. The correct engagement of the switchable reversing device in the clutch results from the fact that this difference in angle values does not change over time. The absolute value of this difference plays no role in monitoring, only the temporal consistency of this difference matters. In other words, in the state monitoring of the present invention, the detection of the angular position and the monitoring of the angular difference at two different positions, that is, before and after the reversing device, are performed not only during the switching process but also during the operation of the printing press. It is monitored whether or not the phase difference (angle difference) once set between the printed portions at the front and the back of the reversing device is maintained. If the phase difference (angle difference) is maintained during the operation of the printing press, it means that the correct engagement state of the clutch of the reversing device is maintained. Conversely, if the phase difference (angle difference) is not maintained during the printing press operation, it means that the clutch has slipped as described above, causing serious printing press damage during printing. May cause operator danger. The condition monitoring of the present invention avoids this risk of significant press damage during printing.

According to the device of the invention, in addition to the first angle transmitter in front of the first reversing device, an additional second angle transmitter is provided behind the last reversing device. I have. The angle transmitter can be configured as an absolute value transmitter, but can also be used as an increment transmitter. The signal of the angle transmitter is directed to a two-sided printing calculator which performs the monitoring according to the invention. The two-sided printing calculator also performs a switching process for switching the operation type from one-sided printing to two-sided printing and vice versa.

Next, an embodiment of the present invention will be described with reference to FIGS. These figures show a sheet-fed printing press having a reversing device behind the first printing unit.

[0010]

1 and 2 show, as a side view and a plan view, the first five printing units of a sheet-fed offset printing press. G is an impression cylinder, and T is a transfer cylinder or feed cylinder provided therebetween. First printing unit and second
Between the impression cylinders of the printing unit there is also provided a reversing cylinder W of twice the size. After a corresponding switch from one-sided printing to two-sided printing, the sheet is turned over in the form of a sheet trailing edge reversal and guided via a reversing cylinder W to a second impression cylinder G. In this case, the sheet is guided via the feed cylinder A to the impression cylinder G of the first printing unit.

A direct-current motor, which is controlled for driving the sheet-fed printing press, is provided in the main drive HA, whereby the longitudinal axis LW is driven. The longitudinal axis LW has in this embodiment three transmission gear units E, by which the impression cylinders G of the first, third and fifth printing units are driven. As shown in FIG. 2, the impression cylinder G, the transfer cylinder T, the reversing cylinder W and the sheet feeding cylinder A are connected to one another via a continuous gear train R. In order to be able to switch over the reversing device, the first impression cylinder G is furthermore mounted in a known manner via two clutches, not shown, which are arranged adjacent to one another and are adjustable relative to one another. It has gear rims that are engaged with each other. The reversing cylinder W has a single-width gear, and the subsequent impression cylinder G has a double-width gear. The impression cylinder G and the transfer cylinder T of the subsequent printing unit also have single-width gears in one plane.

Behind the reversing device and before the second transmission gearing E, an electrically switchable clutch KLW
Are provided in the longitudinal axis LW. The positioning drive PA is mounted on the transmission gear unit E of the third printing unit via a further clutch KPA. This P
A, after the release of the clutch KLW provided in the longitudinal axis LW and after the release of the clutch (not shown) in the double gear rim of the first impression cylinder G, the printing press behind the reversing device. Can be operated from single-sided printing to double-sided printing as per the format. The entire switching process and, for example, the operation of the printing unit in accordance with the format take place via the positioning drive PA under the control of the double-sided printing calculator SWR. This double-sided printing calculator controls another format-dependent switching process, not described here. Here, as an example, only the operation of the paper feeder opening curve from single-sided printing to double-sided printing will be described.

The two-sided printing calculator SWR is connected to two angle transmitters WG1, WG2. First angle transmitter W
G1 is attached to a paper feed cylinder A of the same size so as to make one rotation. The second angle transmitter WG2 is mounted on the end face at the end of the longitudinal axis LW behind the last transmission gear unit E. Since the longitudinal axis LW and the paper feed cylinder A operate at different rotational speeds, the second angle transmitter WG2
A corresponding gearing, not shown, is connected upstream. Therefore, the second angle transmitter WG2 operates at the same rotation speed as the first angle transmitter. The first angle transmitter WG1 is further connected to a printing press controller (not shown). A corresponding control via the first angle transmitter WG1 controls all operations which depend on the printing press rotation angle (eg printing on / off or sheet interrogation). The double-sided printing calculator SWR is connected to a printing press control unit via a bus device (not shown).

A double-sided printing calculator SWR for switching the mode of operation from single-sided printing to double-sided printing and vice versa.
Connects the positioning drive PA to the central transmission gear E via the clutch KPA. In normal printing operation, the positioning drive PA is disengaged via the clutch KPA. Further, the double-sided printing calculator SWR has a longitudinal axis L.
Open the clutch KLW at W as well as the clutch not shown between both gears of the first impression cylinder G. According to the input format, the double-sided printing calculator SWR controls the positioning drive unit PA as follows. That is, control is performed so that the reversing cylinder W and the subsequent printing unit can be switched from, for example, single-sided printing to double-sided printing. For this purpose, the double-sided printing calculator SWR reads the angle value of the second angle transmitter WG2 and determines when the actual value supplied from the second angle transmitter WG2 corresponds to the target value calculated depending on the format. Then, the positioning drive unit PA is stopped. Thus, the positioning drive PA is disengaged again via the clutch KPA, and the clutch on the first impression cylinder G and the clutch KLW on the longitudinal axis are closed. The double-sided printing calculator SWR additionally monitors during the switching process the value supplied by the first angle transmitter WG1 as to whether this value does not change. Therefore, advantageously,
More certainty regarding format switching is obtained. This makes it possible to detect whether the clutch of the reversing device is correctly disengaged.

After the switching process described above, the double-sided printing calculator S
The WR always or at least occasionally compares the angle values supplied from the first and second angle transmitters WG1, WG2. If a change occurs in this difference in the angle values, the double-sided printing calculator SWR triggers a printing press stop, for example via a printing press control (not shown), ie prevents the printing press from starting from a stop condition. . The difference between the two-sided printing calculator SWR comparing the angle values supplied from the first and second angle transmitters WG1, WG2 with each other can be, for example, the difference obtained by a previously performed switching process. Just for high-speed printing presses, the angle values supplied from the first and second angle transmitters WG1, WG2 can be time-critical. Therefore, in accordance with an advantageous embodiment of the invention, the double-sided printing calculator SWR only performs a comparison of the angle values each time the printing press is stopped. This is advantageous, for example, when the angle values of the angle transmitters WG1, WG2 are led via different bus systems to the double-sided printing calculator SWR.

The invention has been described with reference to a sheet-fed printing press having one switchable reversing device as described above.
The query of the angular position of the printing press according to the invention can also be used for printing presses having a plurality of switchable reversing devices. In this case, only the following matters. That is, the first angle detection before the reversing device and the second angle value detection after the last reversing device viewed in the sheet running direction.

[Brief description of the drawings]

FIG. 1 is a side view of the first five printing units of a sheet-fed offset printing press.

FIG. 2 is a plan view of the first five printing units of the sheet-fed offset printing press.

[Explanation of symbols]

 G impression cylinder T transfer cylinder W reversing cylinder A paper feed cylinder HA main drive unit LW longitudinal axis R gear train E transmission gear unit KLW clutch longitudinal axis KPA clutch positioning drive PA positioning drive SWR double-sided printing calculator WG1 first Angle transmitter WG2 Second angle transmitter

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-4-224950 (JP, A) JP-B-57-17714 (JP, B2) (58) Fields investigated (Int. Cl. ⁷ , DB name) B41F 33/00 B41F 33/06 B41F 33/14 B41F 21/00

Claims (2)

(57) [Claims] 1. A condition monitoring device for a switchable sheet-fed printing press having at least one sheet reversing device, wherein the printing press is provided with first and second angles before and after the switchable reversing device. Transmitters (WG1, WG2) are attached, and these angle transmitters (WG1, WG)
2) is connected to a calculator (SWR), which performs the difference formation of the supplied angle values, and the calculator (SWR) is configured as follows: The main drive unit (HA) of the printing press is stopped when a deviation of the obtained angle value difference from a predetermined target value is detected, and the calculator (SWR) determines the position of the drive unit. (PA) connection
And a second angle drive using the positioning drive.
Cooperating with the Shinki (WG2) to switch from single-sided printing to double-sided printing
A state monitoring device for a switchable sheet-fed printing press having at least one sheet reversing device, characterized in that switching and vice versa are performed . Wherein an angle transmitter (WG1, WG2) are constructed as absolute value transmitters of the same type, according to claim 1, wherein.