EP0775655B2 - Vacuum- and/or compressed air controller - Google Patents

Abstract

The air blast controller has an electrically controllable valve whose outlet is directly connected to the pressure connection (32) of the load device via which the pressure or vacuum is delivered through a feed line. The valve is driven by an electronic control device (12) and is connected to the feed line (4). The outlet of the electrically controllable valve can be connected to the pressure connections of several loads. The load and valve can form a single unit or can have a common housing (18). The load device can be a suction device of a sheet feeder.

Description

The invention relates to a suction air control for consumers of a feeder for Feeding sheets to a sheet processing machine Machine, according to the preamble of claim 1.

Such controls are particularly in sheet layers for sheet processing machines to supply vacuum cleaners with vacuum or from Blow nozzles with overpressure required. From the respective Negative or positive pressure source and the corresponding pneumatic control unit lead relatively long supply lines to consumers. The most varied Sheets such as paper, cardboard, cardboard, corrugated cardboard or sheet metal that should be processable require one Adjustment of the intensity and the time of each Pressurization or vacuum application on Consumer.

This is only the case with the known controls possible with restrictions.

A suction air control is known from EP-A-0 194 511 known after the type mentioned. It is by means of an adjustable frequency generator the opening and closing frequency of the valve can be changed.

From DE-C-615 746 it is known by means of of an electromagnet an anchor against the force a spring to be lifted, the anchor in one Cylinder guided piston is arranged. Through the Lifting motion of the piston is on one with the cylinder space connected suction nozzle to a negative pressure Detection of an arc created.

From US-A-4, which is still cited 513 957 a bow dispenser is known in which from a sheet stack by means of pressurizable Suction cups of the top sheet removable and can be spent. To make sure the bows too Two groups of suckers are securely grasped available. It is found that from the first group the sheet is not transported by suction cups, so is controlled via a microprocessor control the second group of suckers which then ensures that the top sheet is gripped and closed an issue is transported.

In the case of a blown air control, it is from EP-A-0 503 623 known an electric valve dependent of parameters that can be entered from an electrical one Control unit.

A suction air control of the type mentioned at the outset is from DE 38 42 390 A1 known.

From DE 40 11 663 A1 is a sheet feeder with a control of the Suction air for a vacuum cleaner in time with the sheet processing machine known in which a ventilation line and a vacuum line by means of a switching valve arranged close to the vacuum can be opened or closed, the in turn by means of a control valve which can be actuated by a cam disk is controllable.

The DD 123 800 is a pneumatic sheet separating and conveying device known for sheet-processing machines that have a rotary slide valve has a suction air outlet and a compressed air outlet has. The suction air outlet and the compressed air outlet are each via lines with a suction air connection and a compressed air connection one connected as a vacuum cleaner of a sheet feeder consumer. The rotary valve is rotatably driven in the work cycle of the sheet feeder.

From DIN-ISO 1219-1, March 1996 are circuits of valves and their arrangements for supplying compressed air to consumers, in particular Directional valves actuated by electromagnets are known.

Solenoid valves are also known in DIN ISO 1219, page 9, 7.2.2.6.

The object of the invention is therefore controls of the type mentioned at the outset, through which the amount of pressure and / or the temporal pressure or Vacuum supply to the consumer can be precisely regulated are characterized by the characteristic features of the Claim 1 solved.

This training means that the vacuum source generated negative pressure or that of Pressure source generated overpressure in a sufficient Volume immediately and in the desired and constant height at the consumer, so that no time delay by emptying or filling the particular different line lengths to the different Supply system having consumers can occur. Significant fluctuations in Pressure or. Vacuum levels can occur and that proper treatment of the sheets to be conveyed negative tangent.

This is especially important when the bow processing machine clocked works and the bow be fed to it exactly in your work cycle have to.

Changes in the timing of work the consumer and the amount of their pressurization can according to the control by the electronic control device directly take effect on consumption consumers. So that z. B. also a fine adjustment of the pressure or negative pressure exactly in terms of pressure level and timing possible.

This ensures an accurate and optimal on the Sheet processing machine set working method the feeding of the sheets to be processed to the sheet processing machine.

Are at the outlet of the electrically controllable Valve the pressure connections of several consumers are connected, so can be arranged with several together like consumers with a single Valve exactly even pressure or vacuum pressures respectively. Unevenly effective this consumer group is excluded so that the exact sheet conveyance is ensured becomes.

It is particularly space-saving when consumers and electrically controllable valve a structural unit form. They also have consumers and electrically controllable valve a common housing, this also reduces the number of required Components.

Particularly precise switching movements and exact Switch positions, in particular intermediate position are possible. When the electrically controllable valve is on Solenoid valve is.

The parameters of the suction or blast air control can by sensors in particular on the bow processing machine detectable and the electronic Control device can be fed.

It is also possible to change the parameters manually the electronic control device can be entered. With this e.g. Data on the nature and quality of the fed each sheet to be conveyed to the control device become. According to the data supplied depending on the program and / or characteristic curve Regulation e.g. the timing, the start and of the end as well as the pressure level and the pressure curve the pressurization or vacuum application of the Consumer through the electronic control device.

Depending on the size to be regulated, this can electrically controllable valve one way and / or one Pressure control and / or a flow control valve. Become can perform several of these functions the various valve functions integrated by an built valve.

Should the ventilation of the vacuum cleaner in your Time and if necessary also in their chronological sequence and can be determined in intensity, so in the second Switch position of the pressure connection of the consumer connectable to a positive pressure source via a control valve his. For this purpose, the control valve is preferably one electrically controllable control valve that also by the electronic control device can be controlled can.

The control valve can be a 2/2-way valve be whose passage is blocked in the first switching position is and in the second switching position the source of excess pressure connects to the electrically controllable valve.

Figur 1

eine Seitenansicht einer Saug- und Blasluftsteuerung

Figur 2

einen Querschnitt einer Sauger/Ventileinheit in Normalstellung

Figur 3

einen Querschnitt der Sauger/Ventileinheit nach Figur 2 in der Saugstellung

Figur 4

ein Schaltbild der Sauger/Ventileinheit nach Figur 2

Figur 5

ein Schaltbild eines zweiten Ausführungsbeispiels einer Sauger/Ventileinheit

Figur 6

ein Schaltbild eines dritten Ausführungsbeispiels einer Sauger/Ventileinheit

Figur 7

ein Schaltbild eines vierten Ausführungsbeispiels einer Sauger/Ventileinheit.

Embodiments of the invention are shown in the drawing and are described in more detail below. Show it

Figure 1

a side view of a suction and blowing air control

Figure 2

a cross section of a suction / valve unit in the normal position

Figure 3

a cross section of the suction / valve unit according to Figure 2 in the suction position

Figure 4

a circuit diagram of the suction / valve unit according to Figure 2

Figure 5

a circuit diagram of a second embodiment of a suction / valve unit

Figure 6

a circuit diagram of a third embodiment of a suction / valve unit

Figure 7

a circuit diagram of a fourth embodiment of a suction / valve unit.

Figures 4 and 7 do not belong to the invention.

The suction and blowing air control shown in Figure 1 for a sheet feeder has one above Sheet stack 1 arranged suction head 2 on which is a vacuum cleaner 3 is arranged. To that Vacuum cleaner 3 leads from a vacuum source, not shown a feed line 4. Through the separating suction 3 is the top sheet of the sheet stack 1 detectable and liftable, in order to then by a not shown Further conveying device such as also on Suction head 2 arranged vacuum cleaners detected and to be promoted.

In the conveying direction 5 behind the sheet stack 1 is approximately level with the top arch directed a blowing air nozzle 6 arranged through the Blown air is blown against the uppermost sheet is so that they are separated from each other, or that under that at its lower end by the Separator 3 raised top bow an air cushion is formed, which is a separation of the top one The entire length of the arch from the one below Arc causes.

The blowing nozzle 6 is fed via a feed line 7 from a pressure source, not shown, with under Pressurized air supplied.

Between the suction pad 3 and its feed line 4 and between the blow nozzle 6 and its feed line 7, a solenoid valve 8 and 9 is arranged, through which the vacuum or overpressure is applied controllable by separating suction device 3 or blowing nozzle 6 is. To control the solenoid valve 8 via a Control line 10 and the solenoid valve 9 via a Control line 11 with an electronic control device 12 connected. If drag vacuums are available, so this can be done in the same way through the electronic control device can be controlled.

The data lines 13 and 14 are electronic Control device 12 data of a not shown Printing machine feedable to which the sheet of the sheet stack 1 are promoted individually.

The data of the printing press can by Sensors detects e.g. Information about speeds, the angle of rotation or the cycle of the printing press his. In addition, sensors can also be used detected pressure values in the feed lines 4 and 7 supplied to the electronic control device 12 become.

Additional data can be entered via inputs 15, 16, 17 such as. about the type and quality of funding Manual sheet of the electronic control device 12 can be entered. According to the data supplied the program is controlled depending on the program Solenoid valves 8 and 9 by the electronic control device 12th

In Figures 2 and 3 are the solenoid valve 8 and the separating suction 3 in cross section both in the raised normal position as well as in the lowered Suction position shown. Solenoid valve 8 and Vacuum cleaners 3 are combined into one unit and have a common housing 18. In the housing 18 is formed with a cylinder bore 19, in which a step piston 20 with its large step 21 is arranged axially movable. With his little one Step 22 of the step piston 20 projects through a bore 23 same cross section down from the housing 18 and supports this protruding from the housing 18 End of a suction nozzle 24.

The step piston 20 is coaxial with a bore 25 provided on a suction surface 26 of the suction nozzle 24 opens out. In the lower end area of the stepped piston 20 branches suction bores 27 from the Bore 25 and also open into the suction surface 26th

The step piston 20 is the small one Cylindrical compression spring 28 enclosing step 22 biased towards its upper end position. there the compression spring 28 is supported with its upper end the large stage 21 of the stepped piston 20 and with it lower end at the transition from the cylinder bore 19 to bore 23.

The lowest possible position of the stepped piston 20 is compressed by the one on block Compression spring 28 defined (Figure 3).

The uppermost position of the stepped piston (fig 2) is by the abutment of the stepped piston 20 on one Stop defined by a stop disc 29th is formed. The stop disc 29 is coaxial in one at the cylinder bore 19 adjoining guide bore 30 larger diameter than the cylinder bore 19 displaceable by a certain amount arranged and has axial spacers 31 against which the stepped piston 20 comes to rest. By the spacer 31 ensures that the bore 25 always with the face of the large step 21 communicated.

A pressure port 32 of the vacuum cleaner 3 is via two bores 33 and 34 with the cylinder bore 19 connected. The bore 33 opens into the End area 23 facing bore in the cylinder bore 19 while bore 34 in the opposite End region of the cylinder bore 19 opens. This is in the raised normal position of the Step piston 20 between the small step 22 and the annular bore wall 35 formed over the both holes 33 and 34 with the pressure connection 32nd connected and pressurizable.

In the lowered suction position Annulus 35 only through the bore 33 with the Pressure port 32 connected. The bore 34 connects then the pressure connection with the cylinder bore 19 above the large level 21. This area of Cylinder bore 19 is then with the bore 25 the suction surface 26 connected so that this vacuum is fed for detecting an arc.

Between the pressure port 32 of the Separating suction and a feed line connection 36, to which the feed line 4 can be connected is a as 3/2-way valve 37 formed magnetic valve.

The 3/2-way valve has one in one Valve housing 38 between two end positions axially movable anchor 39, of a housing-fixed Coil 40 is enclosed. The path of movement of the anchor 39 is aligned vertically. In the interior 41 of the valve housing 38 opens a connection from below 42 to the feed line connection 36 and from above a connection 43 to the outside air. The mouths of the Connections 42 and 43 are opposite Valve seats 44 and 45 are formed. Each of them facing ends of the armature 39 have insert parts 46 made of a sealing material and form valve members, which cooperate with the valve seats 44 and 45.

By a coil which is fixed to the housing 40 supported compression spring 47 is the armature 39 against the lower valve seat 44 biased so that at not energized coil 40, the valve seat 44 is always closed is.

By energizing the coil 40, the armature 39 raised against the force of the compression spring 47 and with the insert 46 against its upper end the valve seat 45 pressed so that the connection 43 of the Interior 41 blocked off from outside air and the interior 43 with the supply connection 36 via the connection 42 is connected. Since the interior 41 continues permanently connected to the pressure connection 32 is dependent on the control of the coil 40 either with the feed line connection 36 or connected to the outside air.

When the coil 40 is not activated and outside air is applied the pressure port 32 is the large step 21 of the step piston 20 on both sides of the Outside air is applied so that the stepped piston 20 moved to its upper position by the compression spring 28 will (Figure 2).

If the coil 40 is energized, it opens of the valve seat 44 and closing the valve seat 45. As permanent at the supply line connection 36 Vacuum is applied, is largely without delay via the pressure connection 32 and the bores 33 and 34 a negative pressure application of the Annulus 35. Since the annulus 35 facing away Side of the large stage 21 through the bore 25 with the Outside air is connected, the stepped piston 20 lowers against the force of the compression spring 28 and moves in its suction position (Figure 3).

With this downward movement the big one drives Step 21 past the mouth of bore 34 so that this then with the side facing away from the annular space 35 of the stepped piston 20 is connected.

The suction surface arrives approximately in the suction position 26 of the suction nozzle 24 on the top sheet of the Sheet stack 1 for edition. This closes the bore 25 and the suction bores 27 through the uppermost arch, so that also over the bore 34 on the side facing away from the suction surface 26, the large one Step 21 of the step piston 20 is subjected to negative pressure and the stepped piston 21 is lifted off with the detected arc becomes. By switching the 3/2-way valve 37 the separating vacuum is exposed to outside air 2 and thus an acceleration of the lifting movement as well as reducing the holding force of the bow, so that this easily through from the raised position e.g. a drag vacuum from the separation vacuum 3 in the conveying direction 5 can be deducted.

A circuit diagram of the 3/2-way valve 37 is shown in FIG 4 shown, the individual parts with the same Reference numerals are provided. To the supply line connection 36, a vacuum source 49 is connected.

The embodiment shown in Figure 5 as a circuit diagram largely corresponds to the embodiment from Figures 2 to 4. The only difference is that the connection 43 is not to Outside air leads to an overpressure source 48, so that the ventilation of the separating vacuum is done faster can.

The embodiment of Figure 6 is one further modification of the training example of the figure 5. The pressure source 48 is not immediate but via one designed as a solenoid valve 2/2-way valve 50 with the connection 43 of the 3/2-way valve 37 connected. With an electromagnet 51 is the 2/2-way valve 50 from its shown Position with blocked passage against the force a spring 52 in its open passage position adjustable. This enables controlled ventilation of the suction cup 3 via the 3/2-way valve 37.

Figure 7 shows a simple embodiment a suction air control according to the invention for a separating suction 3 with a 2/2-way valve 53, the by an electromagnet 54 against the force of one Spring 55 between a supply line connection 36 of the valve with a pressure connection 32 of the Vacuum cleaner connecting position and a locking Position is switchable.

reference numeral

1

sheet pile

2

suction head

3

suction separator

4

feed

5

conveying direction

6

blow nozzle

7

feed

8th

Solenoid valve vacuum cleaner

9

Blow nozzle solenoid valve

10

Control line separating suction

11

Control line blowing nozzle

12

electrical control device

13

data line

14

data line

Claims (11)

1. Suction control for user devices of a feed unit for feeding sheets to a sheet treating machine, particularly a printing press, wherein a pressure connection (32) of the user device can be subjected via a feed lead to reduced pressure from a source of reduced pressure (49), wherein connected directly to the pressure connection (32) of the user device is an outlet of an electrically controllable valve, which can be controlled by a control unit (12), wherein the user device is a sucker provided with a suction surface (26) which can be subjected to reduced pressure from the source of reduced pressure (49) and wherein the electrically controllable valve is controllable by an electronic control unit (12) dependent upon the parameters of the rotational angle and the timing of the sheet treating machine which can be input into the control unit (12), characterised in that the electrically controllable valve is a 3/2 distribution valve in the first switching position of which the feed lead (4) is connected with the pressure connection (32) of the user device and in the second switching position of which the feed lead (4) is blocked and pressure connection (32) of the user device is connected or connectable to a source of excess pressure (48).
2. Control according to one of the preceding Claims, characterised in that connected to the outlet of the electrically controllable valve are the pressure connections of several user devices.
3. Control according to one of the preceding Claims, characterised in that the user device and electrically controllable valve constitute one constructional unit.
4. Control according to Claim 3, characterised in that user device and electrically controllable valve have a common housing (18).
5. Control according to one of the preceding Claims, characterised in that the electrically controllable valve is a magnetic valve.
6. Control according to one of the preceding Claims, characterised in that the parameters can be captured by sensors and can be fed to the electronic control unit (12).
7. Control according to one of Claims 1 to 5, characterised in that the parameters can be input manually to the electronic control unit (12).
8. Control according to one of the preceding Claims, characterised in that the electrically controllable valve is a distribution and/or a pressure control and a volume control valve.
9. Control according to one of the preceding Claims, characterised in that in the second switching position, the pressure connection (32) of the user device is connectable via a control valve with a source of excess pressure (48).
10. Control according to Claim 9, characterised in that the control valve is an electrically controllable control valve.
11. Control according to Claim 9, characterised in that the control valve is a 2/2 distribution valve (50), the passage in which is blocked in the first switching position and which, in the second switching position connects the source of excess pressure (48) with the electrically controllable valve.

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