JPS6228056B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION A sheet-fed printing machine stacks a large number of sheets in its feeder section and supplies them one by one to a printing unit, and then stacks the printed sheets again in a delivery section and discharges them. There is. Since this printing machine performs printing by supplying printing paper sheet by sheet, the position of the printing paper must be adjusted in advance in relation to the printing section before feeding. This position correction is necessary for additional printing in the case of multicolor printing.
Furthermore, even in the case of monochrome printing, when printing on the front and back sides in separate processes, the printing positions on the front and back sides must be aligned in relation to the subsequent cutting process, so positioning is still required. Furthermore, since a large number of sheets of printed paper taken out from the delivery section are cut while being stacked one on top of the other, it is necessary to keep the pattern positions uniform among the printed sheets, and positioning is also required from this point of view.

For position correction or position regulation when feeding printing paper,
Usually, as shown in the first diagram, the front cover 10 and the horizontal needle 12a,
After this correction is made, it is taken out by a gripping claw (not shown) of the printing section on the front cover side. Here, the position regulation of the printing paper 14 by the front cover 10 is done in the running direction A of the printing paper, so it can be done relatively easily and accurately, but the position regulation (needle pulling operation) by the horizontal needle 12, that is, the direction Trajectory correction to B often causes a malfunction and the sheet is sent to the printing unit in a deviated state, resulting in a color shift in the above-mentioned additional printing, or a shift in the design position between sheets after cutting.

Conventionally, the needle pulling operation has been performed using a device as shown in the second figure. In the figure, 16 is a notch provided in the horizontal needle 12, and 18 is a feeder board 20.
The rollers 22 are provided in these notches and are constantly rotating. Therefore, when the sheet 14 traveling on the feeder board in the direction of the arrow A reaches the top of the roller 22, a force is applied in the direction of the arrow B due to frictional force and it is brought into contact with the transverse needle 12a. Next, after the front and rear positions are regulated by the front cover 10, the paper is held in the gripping claws of the printing section and used for printing.

However, since the needle pulling operation as described above is simply due to the action of frictional force due to the rotation of the rollers, if there are factors that reduce the frictional force, such as paper dust adhering to the paper surface, Sometimes things are not done well.

As mentioned above, sheets with such needle-pulling defects cause cutting defects and become defective sheets in the bookbinding process, etc. Therefore, sheets with needle-pulling defects are detected in advance and removed while traveling in the delivery section. Alternatively, it is preferable to mark the location of the defective stapled paper when it is stacked again in the delivery section.

Therefore, conventionally, detectors as shown in FIGS. 3 and 4 have been used to perform the above operations. In Fig. 3, 24 is a floodlight;
Reference numeral 6 denotes a light receiver, which is provided ahead of the rollers 22 in the running direction of the sheet 14 so that the spot-like irradiated light hits a position that is deviated from the side edge of the horizontal needle 12 within a permissible range. It is installed in

On the other hand, in the case of the one in Fig. 4, the needle actuator 2 such as a micro switch is used instead of the light irradiation method.
8 to detect the edge of a sheet.

The detection method described above works well in the initial stage, but begins to malfunction as time passes. That is, in the case of the one shown in Fig. 3, the amount of light received changes due to paper dust, delivery powder for preventing show-through, etc. adhering to the projectors 24 and 26, and when the mechanical detection shown in Fig. 4 is also used, the actuator 2
8 is worn out by contact with paper.

Therefore, these detection methods require frequent cleaning of the light emitter and receiver, replacement of the actuator, and adjustment of its position.

The present invention was made in view of the above-mentioned problems with the detection method.

In other words, although the present invention employs a light projection/reception method, it utilizes outside light such as indoor light as the light projection, and the light receiver is buried in the feeder boat, so that the needle is hardly affected by paper powder, etc. The purpose is to detect whether the pull is good or bad.

Furthermore, the present invention sends the signal from the detector to a computer for processing, and based on the output from the computer, prevents the contamination of defective needle paper at the delivery section or indicates the location of contamination. It is.

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 5 shows a four-color sheet-fed printing press.
In the figure, 30 is a feeder section, 32 is a printing unit for each color, and 34 is a delivery section. and a light receiver 36a for detecting poor needle pulling;
b are installed on both sides of the feeder section 30 along the sheet feeding direction. One of these light receivers 36 is used depending on which of the horizontal needles 12 on both sides shown in FIG. 6 is used.

As shown in FIG. 7, the light receiver 36 includes a light receiving element 38 provided near the side edge of the horizontal needle 12 on the feeder board 20, and a transparent or translucent covering member 40 covering the top or the periphery of the light receiving element 38. It is what it is. The covering member may be made of glass, synthetic resin, or the like. The upper surface thereof is made to coincide with the upper surface of the feeder board 20. This is to prevent the running of the sheet 14 on the feeder board from being obstructed and to keep it in constant contact with the sheet.

The light receiving element 38 is connected via a shielded cable to a control device 42 (FIG. 5) consisting of an electronic computer.

The printing machine also includes a timing pulse generator 44, which includes a micro switch, etc., to generate a pulse for each sheet passing through the printing machine.
is provided in the feeder section 30, and a counter 46 for printed sheets and a removal device 48 for removing sheets with defective stitching are provided in the delivery section 3.
A body insertion detector 50 is provided in the first unit 32a and is provided at the first unit 32a to detect that printing pressure is applied at the start of printing. These timing pulse generator 44, counter 46, removal device 4
8. The body insertion detector 50 is also in communication with the control device 42.

FIG. 8 is a block diagram of a signal processing process in which the signals from the light receiving element 38 are processed to select those corresponding to poor needle pulling and are utilized.

As shown in the figure, the signal generated by the light receiving element 38 passes through an initial amplifier 52, an analog switch 54, and an A/D (analog/digital) converter 56, and then reaches an input section 58 of the computer. . A tolerance setting device 60 is connected to the input unit 58 for digitally setting the allowable distance between the horizontal needle 12 and the edge of the paper in relation to the characteristics of the printing machine and the required printing accuracy. A delay number setting device 62 for setting the time required for a sheet to reach the defective staple paper removal device 48 from the detection position is connected, and the timing pulse generator 44 is connected thereto.

Further, 64 is a central processing unit, to which the input section 58, internal storage device 66, and output section 68 are connected.

The output section 68 is connected to the needle-pull defective paper removing device 48 and the counter 46. Alternatively, instead of or in addition to the removing device 48, an alarm device or a device for indicating the position where the defective stapled paper is present among the discharged sheets of the delivery section 34, such as inserting a tape, indicates the position. A tape inserter or the like is connected to the output section 68.

As the removing device 48, for example, the one shown in FIG. 9 can be adopted. In the figure, 70 is a cylinder in the final printing unit 32d;
is a pile of normally printed paper accumulated in the delivery section,
Reference numeral 74 indicates a pile of paper with poor stitching. A dividing plate 76 is provided between the stack of sheets and the final printing unit, and is held rotatably about a fulcrum 78, and this rotation is made by an air cylinder 80. ing.

If the signal sent from the light receiver 36 corresponds to a needle drawing defect, this signal will reach the valve of the air cylinder 80 as a driving signal via the computer. Then, by one rotation of the dividing plate 76, the paper with poor stitching is caused to fall downward and removed.

Next, a method of selecting a signal corresponding to the occurrence of needle pulling defect from the signals generated by the light receiver 36 will be described.

In the present invention, indoor light installed near the printing machine or the like is used as the external light to be applied to the light receiver.

FIG. 10 shows the amount of external light that reaches the light receiver and the degree of poor stitching (distance between the horizontal needle and the edge of the paper) in relation to sheets of paper. The diagonal lines correspond to different types of sheets. L is the allowable distance and varies depending on the required print quality.

Now, let us use the sheet corresponding to the diagonal line 82, and let Emax be the maximum amount of light received within the range of acceptable needle drawing defects, and the minimum amount of light received with the best needle drawing.
Emin, if the amount of light received at any needle pull is E, then
When E exceeds Emax, that E is taken out as a needle pulling defect signal, and if it is smaller than Emax, it is considered normal and no signal is issued. Then, Emax may be set in the permissible value setting device.

However, since Emax fluctuates depending on the strength of external light, it is not desirable to input it as a constant value.
This is because a situation may occur where the amount of light used when setting Emax becomes excessive when the device is activated, causing E to exceed Emax, and in such a case, the amount of light used to set Emax may exceed Emax, and in such a case, the amount of light used to set Emax may exceed Emax. This is because it will be removed. In addition, when a worker passes by the light receiver, defective stapled paper is running on the feeder board, and external light is transmitted, causing a drop in E, resulting in the defective paper not being detected. This is because such a situation occurs.

Therefore, Emax is stored in the storage section of the computer with a range given in consideration of the fluctuations in the external light. For example, if the variation in Emax is due to the shadow of a worker, then the time that the shadow blocks the light receiver and the speed at which the sheet travels on the feeder board should be compared and examined in advance, and this result can be calculated.
Set by programming by giving it to Eax. Normally, a considerable number of sheets pass over the receiver during the time it takes for a person to pass by the receiver. Therefore, when E decreases over such a long period of time, Emax is also programmed to decrease automatically.

Also, if the fluctuation in Emax is due to the addition of sunlight to the illumination light, the amount of light reaching the receiver will also increase, but when the needle is pulled normally, E
It is programmed to level up Emax so as not to exceed Emax.

This will be explained using the flowchart shown in FIG.
First, E is fetched, and then it is checked whether E is continuously changing. If E is continuously changing, Emax is corrected, and the next E is fetched. Here, to explain the correction of Emax in a little more detail, first
If the value of E changes to a larger value, Emax is corrected to a higher value, and if the value of E changes to a smaller value, Emax is corrected to a lower value.
By the way, if E does not continue to change, next check whether E is greater than Emax.
If it is large, it means that the stitching is defective, and the defective paper should be removed. Furthermore, if E is not larger than Emax, then the needle is drawn well, and the next E is taken in.

On the other hand, when the sheet 14 travels on the feeder board, its front and rear ends are overlapped by the preceding sheet and the following sheet. Therefore, a timing pulse as shown in FIG. 11a is generated so that only the external light that passes through the portions where the sheets do not overlap can be extracted. The timing pulse is generated by a pulse generator 44.
, and reaches the central processing unit 64 via the input section 58 .

Further, each sheet comes into contact with the roller 22 and is needle-stretched, and is then held and pulled by the gripping claws of the printing section, and the time required for this operation is shown in Fig. 12a.
It is created in a computer as a signal such as .

The outside light transmitted through each sheet is sent to a light receiver 36.
Then, it becomes an electric signal and the initial amplifier 52
The signal reaches the analog switch 54 via , where the signal from either one of the light receivers 36 is deleted. This is accomplished by switching an analog switch, and a gate signal as shown in FIG. 12C corresponding to the side of the light receiver 36a covered by the sheet 14 as shown in FIG. This is accomplished by delayed formation. Δt is the time required from the completion of needle pulling until the switching of the analog switch is processed within the computer. Finally, a signal as shown in FIG. 12d reaches the inside of the computer. The completion of needle pulling is normally detected by a proximity switch or the like.

Here, if a needle pulling failure occurs on the feeder board 20, the amount of light received by the light receiver 36 is
becomes a signal exceeding Emax, and under the action of the gate signal, a needle pull failure signal as shown in FIG. 11b is formed.

Further, this signal is converted into a signal delayed by a predetermined time as shown in c by the signal shown in FIG. It will be done.

Then, the poorly stapled paper is removed while traveling through the delivery section, or its position is indicated by a tape while the printed papers are being piled up. The signal processing process will also become clear from the flowchart in FIG.

According to the present invention, a detector similar to the light receiver 36 is installed near the front cover 10 to detect overshooting of sheets, etc., and the signal generated based on this is processed as described above. It is also possible to remove or indicate sheets that are out of register due to overshooting.

Now, in the present invention, as described above, the upper surface of the light receiver is aligned with the upper surface of the feeder board, and the light is emitted from indoor light. In addition, since the light receiver is constantly being rubbed by sheets of paper, the light receiver is also prevented from adhering to paper dust, etc., and is always kept in a good light receiving condition. This is possible.

Furthermore, according to the present invention, the signal from the photoreceiver reaches the electronic computer, and from there the signal is sent to the defective paper removal device, etc., so that even indoor light can be used as the light source for detection. By removing disturbances in advance and extracting appropriate signals, it is possible to accurately eliminate or indicate defective paper.

[Brief explanation of the drawing]

FIG. 1 is a layout diagram of the front cover and the horizontal needle in the delivery section. Figure 2 is a plan view of the needle pulling device, Figure 3
FIG. 4 is a side view illustrating a detection device in a needle-pulled state. FIG. 5 is a schematic plan view of the sheet-fed printing press. FIG. 6 is a plan view of a delivery section in which a detector according to the present invention is installed, and FIG. 7 is a sectional view taken along the line -- in FIG. 6. FIG. 8 is a block diagram of the signal processing process in the present invention. FIG. 9 is a schematic diagram of an example of a device for removing defective stapled paper. 10th
The figure is a graph showing the relationship between the amount of received light and the degree of needle pulling. FIG. 11 is an analog switch operation time chart. FIG. 12 is a time chart for setting the number of delays. FIG. 13 is a signal processing flowchart.
FIG. 14 is a flowchart of Emax correction processing. 12a, b... Horizontal needle, 14... Sheet, 20...
...Feeder board, 22...Colo, 30...Feeder section, 34...Delivery section, 36a, b...
... Light receiver, 38 ... Light receiving element, 40 ... Covering member, 44 ... Timing pulse generator, 48 ...
...Needling defective paper removal device, 58...Input section, 62...
...Delay number setting device, 64...Central processing unit, 66
. . . Internal storage device, 68 . . . Output section.

Claims (1)

[Claims] 1 Covered with a transparent or translucent covering member, and installed on the feeder board near the horizontal needle side edge of a sheet-fed printing press so that the upper surface of this covering member coincides with the upper surface of the feeder board. , an electronic computer to which an output signal of the light receiving element generated by receiving external light such as indoor light through the printing paper passing through the feeder board and the covering member is inputted, and outputs a signal when a needle drawing defect occurs; , a needle removal defective paper removal device or an indicating device operated by a signal output from the electronic computer; , a reference value adjustment device that determines that external light is fluctuating due to external disturbances and lowers or increases a reference value for determining the quality of needle pulling; A needle for a sheet-fed printing press, comprising a needle drawing defect determination device that compares an output signal of an element with a reference value and determines that the needle drawing is defective if the output signal is larger than the reference value. Pull failure detection device.