Suction head mechanism control of sheet feeder

Abstract

The invention relates to a device for controlling a suction head mechanism (1) for a feeder (20) for sheets (3), the suction head mechanism (1) comprising a lifting suction device (2) for lifting sheets (3) from a stack (4) and a pull suction device (5) for sequentially receiving sheets (3) from the lifting suction device (2), characterized in that at least one distance sensor (10) is arranged on the suction head mechanism (1), at least one distance sensor (10) is provided which points to the respective sheet (3) held by the lifting suction device (2), the at least one distance sensor (10) is controllably connected to an adjustment drive (7) arranged on the suction head mechanism (1), and the adjustment drive (7) is drivingly connected to at least one of the pull-type suction devices (5), in order to adjust a defined distance (A) between the pull-type suction device (5) and the sheet (3) held by the lift-type suction device (2).

Description

Technical Field

[0001] The invention relates to a device for controlling a suction head mechanism of a feeder for sheets, wherein the suction head mechanism comprises a lifting suction device for lifting sheets from a stack and a dragging suction device for successively receiving sheets from the lifting suction device. Background Art

[0002] Such devices are used in feeders of printing presses, die-cutters and other sheet processing machines.

[0003] A lifting suction machine is a synonym for a truncation suction machine, and a trailing suction machine is a synonym for a conveying suction machine. Synonyms of .

[0004] DE 22 20 535 C2 describes a suction head mechanism, which comprises a separation suction device and a transport suction device, wherein a mechanical device for controlling the suction head mechanism is provided. Summary of the invention

[0005] The object of the present invention is to provide another device for controlling a suction head mechanism.

[0006] This object is achieved by a device for controlling a suction head mechanism of a sheet feeder, wherein the suction head mechanism comprises a lifting suction device for lifting sheets from a stack and a dragging suction device for successively taking over (übernehmen) sheets from the lifting suction device, characterized in that at least one distance sensor is arranged on the suction head mechanism, the distance sensor points to the corresponding sheet held by the lifting suction device, the at least one distance sensor is connected to an adjusting drive (Stellantrieb) arranged on the suction head mechanism in terms of control technology, and the adjusting drive is connected to at least one of the dragging suction devices in a driving manner The suction device is connected to the lifting device in order to set a specific distance between the pulling suction device and the sheet held by the lifting suction device.

[0007] In the device according to the invention, the manual operation effort is reduced and machine downtime, which may be caused by operating errors when manually adjusting the height of the trailed vacuum cleaner, is avoided.

[0008] The following developments of the device according to the invention are possible:

[0009] The adjusting drive can be connected in a driving manner to another of the trailing vacuum devices in order to set a specific distance between the other trailing vacuum device and a sheet held by the lifting vacuum device.

[0010] A further distance sensor can be arranged on the suction head mechanism, which is directed toward the respective sheet held by the lifting suction device and can be connected in terms of control technology to a further adjustment drive arranged on the suction head mechanism.

[0011] The further adjusting drive can be connected in a driving manner to the further trailing suction device in order to set a defined distance between the further trailing suction device and the sheet held by the lifting suction device. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Further developments emerge from the following description of exemplary embodiments and the corresponding figures.

[0013] The accompanying drawings show:

[0014] Figure 1 The side view shows the suction head mechanism when lifting a sheet from the stack by means of a lifting suction device.

[0015] Figure 2 Shown in side view Figure 1 The suction head mechanism shown is in the state of automatically adjusting the height of the towed suction machine.

[0016] Figure 3 Shown in side view Figure 1 and Figure 2 The suction head mechanism shown is in the state when the sheet is transported by the dragging suction device.

[0017] Figure 4 According to a first variant, a single distance sensor is shown in a top view. Figures 1 to 3 The lifting type suction device and the dragging type suction device of the suction head mechanism shown,

[0018] Figure 5 According to a second variant, a plan view of a plurality of distance sensors is shown. Figures 1 to 3 The lifting type suction device and the dragging type suction device of the suction head mechanism shown, and

[0019] Figure 6 A schematic diagram is shown for Figures 1 to 3 The dragging suction device of the suction head mechanism shown has a regulating circuit for height adjustment.

[0020] In all drawings, the same elements are provided with the same reference numerals. DETAILED DESCRIPTION

[0021] A suction head mechanism 1 is arranged in a feeder 20 of a die-cutter or printing press. The suction head mechanism 1 comprises a separating or lifting suction device 2 for lifting a sheet 3 from a stack 4 and also a conveying or dragging suction device 5. The dragging suction device 5 receives the lifted sheet 3 from the lifting suction device 2 and conveys it further in a horizontal conveying movement 6. Reference numeral "23" denotes a dragging suction device support.

[0022] In the first variant ( Figures 1 to 4 ), a common adjustment drive 7 for these towed suction devices 5 is arranged on the suction head mechanism 1 in a fixed position and is connected to each towed suction device 5 in a driving manner via a rope pulley 22 and a traction cable 8. Instead of the traction cable 8, other similar transmission components that can follow the conveying movement 6 can also be provided to connect the adjustment drive 7 to the towed suction device 5. The adjustment drive 7 is used to adjust the height of the towed suction device 5 by motor, and to adjust the height position of the towed suction device 5 relative to the lifting suction device 2 and the sheet 3 held by the lifting suction device 2. Here, these towed suction devices 5 respectively perform vertical adjustment movements 9. A distance sensor 10 is arranged on the suction head mechanism 1, and the distance sensor 10 points to a measuring point 11 on the sheet 3 held by the lifting suction device 2. The distance sensor 10 is fixed in position and does not follow the conveying movement 6 of the towed suction device 5. The measuring point 11 is located in the immediate vicinity of the position 12 which one of the trailing suction devices 5 takes up when taking over the sheet 3 from the lifting suction device 2. The distance sensor 10 measures the vertical distance between the distance sensor 10 itself and the sheet 3 held by the lifting suction device 2 without contact (e.g. optically). From this distance and the known vertical distance between the distance sensor 10 and the trailing suction device 5, the distance A between the trailing suction device 5 and the sheet 3 can be calculated by addition or subtraction. The distance sensor 10 and the regulating drive 7 are components of a regulating loop 13, which includes the trailing suction device 5 and a regulator 15. In addition, a memory 14 is provided for the measured values ​​of the distance sensor 10.

[0023] In the second variant ( Figures 1 to 3 , Figure 5), there are different adjustment drives 7 for each towed suction device 5. These adjustment drives 7 are arranged on the suction head mechanism 1 in a fixed position. Each adjustment drive 7 is connected to a different towed suction device 5 by a traction cable 8, so as to perform the height adjustment of the towed suction device 5. Instead of the traction cable 8, other similar transmission components that can follow the conveying movement 6 can also be provided to connect the adjustment drive 7 to the towed suction device 5. These adjustment drives 7 adjust the height position of these towed suction devices 5 relative to the lifting suction device 2 and the sheets 3 held by the lifting suction device 2. Here, these towed suction devices 5 respectively implement vertical adjustment movements 9. Distance sensors 10 are arranged on the suction head mechanism 1, and these distance sensors 10 point to measuring points 11 on the sheets 3 held by the lifting suction device 2. Each distance sensor 10 is fixed in position and does not follow the conveying movement 6 of the towed suction device 5. Each measuring point 11 is assigned to a different drag suction device 5, wherein the corresponding measuring point 11 is located in the immediate vicinity of the position 12 which the corresponding drag suction device 5 occupies when taking over the sheet 3 from the lift suction device 2. The corresponding distance sensor 10 measures the vertical distance between the distance sensor 10 itself and the sheet 3 held by the lift suction device 2 without contact (e.g. optically). From this distance and the known vertical distance between the distance sensor 10 and the drag suction device 5, the distance A between the drag suction device 5 and the sheet 3 can be calculated by addition or subtraction. The distance sensor 10 and the regulating drive 7 are components of structurally identical regulating loops 13, which respectively include one of the distance sensors 10 and one of the regulating drives 7. Each regulating loop 13 also includes a regulator 15. Each regulating loop 13 is assigned a memory 14 for the measured values ​​of the corresponding distance sensor 10.

[0024] Figure 6 A closed control loop 13 is shown, which can be the control loop 13 of the first variant or one of the control loops 13 of the second variant. The guide variable or command variable 16 of the control loop 13 is the rated distance between the dragging suction device 5 and the sheet 3. The rated distance is in the range of 1 to 3 mm. The control variable or regulating variable 17 is the height position of the dragging suction device 5 relative to the sheet 3 held by the lifting suction device 2. The interference variable 18 exists as a median or average value, which is formed by a certain number of the latest measured values ​​of the distance sensor 10, for example, always by the last ten measured values. These measured values ​​are stored in the memory 14. The feedback 19 of the control loop 13 is the actual distance between the dragging suction device 5 and the lifted sheet 3.

[0025] Thus, the automation of the height adjustment of the trailing vacuum cleaner is achieved. With the help of one (first variant) or more (second variant) distance sensors 10, the height of the sheet 3 to be gripped is determined in the area of ​​the trailing vacuum cleaner 5. One or more distance sensors 10 measure the height of the sheet 3 lifted by the lifting vacuum cleaner 2 in the area of ​​one or more trailing vacuum cleaners 5 at each rotation of the machine. The measured height is the basis for the electric adjustment of the height of the trailing vacuum cleaner 5. The above measurement is performed after the lifting vacuum cleaner 2 has completely lifted the uppermost sheet 3 from the stack 4, after the load-bearing air blower 21 is switched on, and before the trailing vacuum cleaner 5 grabs the sheet 3. Based on the measurement signal of the one or more distance sensors 10, the height of the trailing vacuum cleaner is electrically adjusted to the ideal value and, if necessary, supplementary adjustments are made during operation. Through the described automation method, the height of the trailing vacuum cleaner is automatically adjusted during the commissioning process. During continuous operation of the machine, the height of the trailing vacuum cleaner is continuously adapted so that the vertical stroke of the trailing vacuum cleaner 5 when gripping a sheet 3 is always minimal. This stroke can be in the range of 1 to 3 millimeters.

[0026] This has the following advantages:

[0027] These dragging suction devices 5 can be set to a very small distance from the sheets 3 held by the lifting suction devices 2. Due to such a small distance, the stroke performed by the dragging suction devices 5 when grabbing the sheets 3 is also correspondingly small, and the dragging suction devices 5 only lift the sheets 3 to a minimum. This leads to a smooth sheet separation process (Vereinzelungsvorgang), without sheet movements that could cause separation problems. The quality of the sheet flake formation (Bogenschuppenbildung) of the feeder 20 is improved.

[0028] Reference numerals list

[0029] 1. Suction head mechanism

[0030] 2 Lifting suction device

[0031] 3 pages

[0032] 4 Stack

[0033] 5 Towed Suction Machine

[0034] 6 Conveying movement

[0035] 7 Adjusting the drive

[0036] 8 Traction cable (Seilzug)

[0037] 9 Adjustment Movement

[0038] 10. Distance sensor

[0039] 11 Measurement points

[0040] 12 Location

[0041] 13 Regulation loop

[0042] 14 Memory

[0043] 15 Regulator

[0044] 16 Instruction variables

[0045] 17 Adjustment parameters

[0046] 18 Interference parameters

[0047] 19 Feedback

[0048] 20 Feeder

[0049] 21 Carrying air blower

[0050] 22 Rope pulley

[0051] 23 Towed suction device bracket

[0052] A Spacing

Claims

1. A device for controlling a suction head mechanism (1) of a feeder (20) for sheets (3), wherein: The suction head mechanism (1) comprises a lifting suction device (2) for lifting sheets (3) from a stack (4) and a dragging suction device (5) for sequentially receiving the sheets (3) from the lifting suction device (2). It is characterized in that At least one distance sensor (10) is arranged on the suction head mechanism (1), and the distance sensor points to the corresponding sheet (3) held by the lifting suction device (2). The at least one distance sensor (10) is connected to an adjustment drive (7) arranged on the suction head mechanism (1) in terms of control technology, and The adjusting drive (7) is connected to at least one of the trailing suction devices (5) in a driving manner in order to set a certain distance (A) between the trailing suction device (5) and a sheet (3) held by the lifting suction device (2).

2. The device according to claim 1, It is characterized in that The adjusting drive (7) is connected to another of the trailing vacuum cleaners (5) in a driving manner in order to set a certain distance (A) between the trailing vacuum cleaner (5) and a sheet (3) held by the lifting vacuum cleaner (2).

3. The device according to claim 1, It is characterized in that Another distance sensor (10) is arranged on the suction head mechanism (1), and the other distance sensor points to the corresponding page (3) held by the lifting suction device (2), and The further distance sensor (10) is connected in terms of control technology to a further adjustment drive (7) arranged on the suction head mechanism (1).

4. The device according to claim 3, It is characterized in that The further adjustment drive (7) is drive-connected to another of the trailing vacuum devices (5) in order to set a certain distance (A) between the trailing vacuum device (5) and a sheet (3) held by the lifting vacuum device (2).

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