RU2237607C2 - Sheet transportation and stacking device - Google Patents

Abstract

FIELD: metallurgy, metal working, wood working, chemical, paper and other industries.

SUBSTANCE: in process of stacking, sheet is moved under rarefication chamber with ejection of air from chamber and is separated from chamber by reducing rarefication with subsequent placing sheet in stack or transportation beyond the limits of rarefication chamber. Air is ejected from rarefication chamber section-by-section and only from those sections of chamber which are covered by moving sheet. Rarefication over sheet is maintained automatically at optimum level. Device is furnished with mechanism to feed sheets, and rarefication chamber with drive conveyor, ejector and air collector connected to ejector. Multisection rarefication chamber is used in device, each section being furnished with shutoff valve communicating section with air manifold after overlapping of section by moving sheet. Device is provided with system for automatic control of rarefication over moving sheet and system to reverse air from ejector outlet into rarefication chamber. Each section of rarefication chamber of device can be provided with separate ejector. Invention makes it possible to reduce power consumed by ejector and considerable reduce power consumption of device.

EFFECT: reduced power consumption, weight and overall dimensions of device.

17 cl, 23 dwg

Description

The invention relates to devices for transporting and stacking sheets and can be used in various industries where sheet materials are manufactured and / or used, in particular in the metallurgical, metalworking, woodworking, chemical, pulp and paper and other industries.

A device for transporting and stacking sheets containing a feeding unit, a rarefaction chamber with a window at its lower end and an ejector (fan), a conveyor envelope and an air supply nozzle located under the rarefaction chamber window and connected to an additional fan (ed. USSR No. 1342851, B 65 N 29/32, declared 05.05.86, publ. 07.10.87, BI No. 37).

The use of a known device for pumping air into the rarefaction chamber to tear off the sheet causes additional energy consumption for the operation of the device and at the same time complicates the design and increases the dimensions and weight of the device by introducing a nozzle with an additional fan into it. In addition, the disadvantage of the known device is the high level of energy consumption for laying and transporting sheets, due to the fact that during the movement of the sheet under the rarefaction chamber, the lower end of the latter remains open and air is constantly ejected through it. In such conditions, to create a predetermined degree of rarefaction over a moving sheet that is necessary to hold it under the rarefaction chamber, a high air flow rate and, consequently, a large air flow rate, and, therefore, a large fan capacity, requiring high energy consumption, and causing large dimensions, are required and a large weight of the fan with its drive, which ultimately affects the energy, overall and weight performance of the device.

Closest to the proposed device in technical essence is the prototype device for transporting and stacking sheets, containing a mechanism for feeding sheets, a vacuum chamber with a drive conveyor and an ejector, a lifting table for stacking sheets, mounted under the vacuum chamber, and an air collector located above a rarefaction chamber and connected to the input of the ejector, while the rarefaction chamber is made in the form of a series of sections, longitudinal with respect to the direction of movement of the sheet, each of which has two longitudinal and two lateral walls transverse relative to the indicated direction and the upper wall covering them with an outlet window communicating the internal cavity of the section with the air manifold, and equipped with a shut-off valve mounted on its upper wall with the possibility of closing the last outlet, with a shut-off valve of each section of the rarefaction chamber is equipped with a drive configured to open the shutoff valve at the end of the overlap of the section of the rarefaction chamber with a moving sheet and close the specified valve after separation on a sheet from the vacuum chamber - the device is in the stacking mode, sheets or the moving sheet before exiting from the said section - during operation in the conveying mode sheets (US Patent №3845950, cl. In 65 H 29/32, decl. 08/25/1971, publ. 11/05/1974).

A disadvantage of the known device is the possibility of lateral deflection and permanent deformation of the sheets, moreover, this possibility increases with the width of the stacked and transported sheets and, accordingly, the width of the vacuum chamber of the device. Another disadvantage of the known device is that all sections of its rarefaction chamber are serviced by one common ejector (fan), which necessitates the use of a high-capacity fan in the known device, prone to reach surge mode and having a large mass and dimensions with high energy consumption. In turn, the fan’s tendency to enter surge mode reduces the reliability of the device and requires the installation of anti-surge equipment in the known device, which complicates the design of the device.

An object of the invention is to eliminate the possibility of lateral deflection and permanent deformation of the sheets and to provide the possibility of using low-power fans with low energy consumption in the device, eliminating the possibility of their reaching the surge mode.

The technical result of the invention is to maintain the conditionability of stacked and transported sheets by eliminating the possibility of their transverse deflection and residual deformation, as well as increasing the efficiency of the fan by reducing energy consumption and increasing its reliability by eliminating the possibility of the fan entering the surge mode. In addition, the technical result of the invention is also to reduce the size and weight of the fan due to the use of low-capacity fans in the device, as well as simplifying the design of the device by eliminating the need to install anti-surge equipment on it, eliminating the fan output to surge mode.

The technical result of the invention is achieved by the fact that in the proposed device for transporting and stacking sheets, comprising a mechanism for feeding sheets, a vacuum chamber with a drive conveyor and an ejector, a lifting table for laying sheets, mounted under the vacuum chamber, and an air collector located above the vacuum chamber and connected to the input of the ejector, while the rarefaction chamber is made in the form of a series of sections longitudinal with respect to the direction of movement of the sheet, each of which has two longitudinal and two pop lateral walls relative to the indicated direction and the upper wall covering them with an outlet window communicating the internal cavity of the section with the air collector and equipped with a shut-off valve mounted on its upper wall with the possibility of closing the outlet window of the latter, while the shut-off valve of each section of the rarefaction chamber is equipped with a drive configured to open the shutoff valve at the end of the overlap of the rarefaction chamber section with a moving sheet and close said valve after the sheet is torn off rarefaction - when the device is in sheet-laying mode or before the moving sheet exits from under the indicated section — when the device is in sheet-transport mode, in contrast to the prototype, the vacuum chamber is equipped with at least one additional longitudinally directed row of sections with the formation of transverse relative to the direction of movement of the sheet of rows of sections of the rarefaction chamber, each of which includes a section of the main row and the adjacent section of the additional row, while the shut-off valves of the sections of each pop The row of rows is equipped with a common drive, made with the possibility of their simultaneous opening and closing.

The device can be equipped with a system for automatically regulating the rarefaction in sections of the rarefaction chamber covered by a moving sheet, which can be made in the form of a volumetric air flow regulator connected to the ejector, ejected from the rarefaction chamber, and a control device containing a pressure sensor connected to the internal cavity of the air manifold , a sensor for the volumetric flow rate of air ejected from the rarefaction chamber, a correction unit and a software device in which the input is connected to the sensor phenomenon, and the output - to one of the inputs of the correction unit, the second input of which is connected to the sensor volumetric flow rate of air ejected from the vacuum chamber, and an output - to a controller of said flow.

The ejector of the rarefaction chamber in the proposed device can be made in the form of a blade fan equipped with an adjustable drive. In this case, said automatic rarefaction control system can also have two other versions, according to the first of which at least one bypass window can be made in the air manifold of the device to bypass air from the environment to the collector, and the automatic rarefaction control system in sections of the rarefaction chamber, overlapped by a moving sheet, can be made in the form of at least one adjustable bypass valve mounted on an air manifold with by changing the area of the passage section of the bypass window of the last and equipped with an adjustable drive with a control device containing a pressure sensor connected to the internal cavity of the air manifold, a correction unit and a software device, the input of which is connected to the input device into it of the volumetric air flow through the fan, and the output - to one of the inputs of the correction unit, the second input of which is connected to a pressure sensor, and the output to an adjustable bypass valve actuator. In the control device of the adjustable bypass valve actuator, the input device into the software device for the volumetric flow rate of air through the fan can be made in the form of a manual input device of the specified value or in the form of a sensor of the specified flow rate.

According to the second embodiment of the automatic rarefaction control system when using a fan as a rarefaction chamber in the air manifold of the device, at least one bypass window can be made for bypassing air from the environment into the collector, and said automatic rarefaction control system may include at least one adjustable bypass valve mounted on the air manifold with the ability to change the area of the passage section of the bypass o to the latter and equipped with an adjustable drive, a volumetric air flow controller through a fan connected to the drive of the latter, and a control device containing a pressure sensor connected to the internal cavity of the air manifold, a volumetric air flow sensor through a fan, a rarefaction correction unit, a volumetric air flow correction unit through a fan and a software device, in which one input is connected to a pressure sensor, the second input to a volumetric air flow sensor through a fan, one you od - to the input of the rarefaction correction block and the second output to the input of the volumetric flow rate correction block through the fan, while the rarefaction correction block has a second input connected to the pressure sensor and an output connected to an adjustable bypass valve actuator, and the volumetric flow correction block air through the fan has a second input connected to a sensor of the specified flow rate, and an output connected to the regulator of the latter.

The device can be made with a system for reversing the air flow at the outlet of the ejector, which ensures the return of air from the outlet of the latter in the section of the first transverse row of sections of the rarefaction chamber along the sheet or into the air collector. Moreover, a device made with a system for reversing the air flow from the outlet of the ejector to the indicated sections of the rarefaction chamber can be equipped with an air duct with an outlet pipe located in front of the first transverse row of sections of the rarefaction chamber along the sheet, and each section in this row can be made with an inlet window for the passage of air, communicating its internal cavity with an air duct in which there is a two-position valve, configured to overlap the inlet windows of the sections specified row in the initial closed position and the possibility of translating into the open position with the opening of the indicated inlet windows and simultaneously blocking the passage of air from the air duct to the outlet of its outlet pipe and ensuring the passage of air from the air duct into sections of the indicated row through their inlet windows, while the ejector communicates with its output air duct and is installed near the indicated row of sections of the vacuum chamber, and the on-off valve is equipped with a drive configured to open the valve before tearing off the sheet and from the vacuum chamber and closing the valve after the specified separation. In the case of a device with a system for reversing the air flow from the outlet of the ejector to the air manifold, it can be equipped with an outlet pipe connected to the outlet of the ejector, which is installed close to the outlet of the air manifold, and the latter can be made with an inlet window for the passage of air communicating the internal cavity an air manifold with an outlet pipe, in which a two-position valve is placed, configured to overlap the inlet window of the air manifold in the original closed position and the possibility of translating into the open position with the opening of the specified inlet window and simultaneously blocking the air passage from the ejector to the outlet of the exhaust pipe and providing air passage from the ejector to the air manifold through its inlet window, while the on-off valve is equipped with an actuator configured to opening before separation of the sheet from the vacuum chamber and closing after the specified separation.

In each section of the rarefaction chamber of the device, the transverse side walls can be configured to interact with the moving sheet by rotating these walls relative to the upper wall of the section in the direction of movement of the sheet, and the longitudinal side walls can be configured to interact with the moving sheet by fitting them with lower ends the surface of the specified sheet, while the transverse side walls of the section can be spring-loaded relative to its upper wall with the possibility of their return together with the longitudinal E section of the side walls to the original position after the separation of the sheet from the vacuum chamber or after its exit from the latter.

The lower end part of the rarefaction chamber of the device, interacting with a moving sheet, can be made of a material having a small coefficient of friction, for example, fluoroplastic.

The technical result of the invention is also achieved by the fact that in the second embodiment of the device for transporting and stacking sheets, containing a mechanism for feeding sheets, a vacuum chamber with a drive conveyor and a lifting table for laying sheets installed under the vacuum chamber, while the vacuum chamber is made in the form of a longitudinal relative to the direction of movement of the sheet of a number of sections, each of which is connected to the ejector and has two longitudinal and two lateral walls transverse relative to the specified direction and the upper wall covering them, in contrast to the prototype, the rarefaction chamber is equipped with at least one additional longitudinally directed row of sections with the formation of rows of sections of the rarefaction chamber transverse relative to the sheet direction of movement, each of which includes a section of the main row and an adjacent section of the additional row wherein each section of the rarefaction chamber is equipped with an ejector mounted above its upper wall and communicating with the internal cavity of the specified section, every two adjacent sections in each The home row of sections of the rarefaction chamber is equipped with a shut-off valve installed between these sections and configured to separate the sections from each other in its initial closed position and the possibility of their communication in its open position, and in each two adjacent transverse rows of sections of the rarefaction chamber, the shut-off valves of adjacent sections equipped with a drive made with the possibility of their simultaneous opening at the end of the overlapping of the adjacent adjacent rows of sections of the rarefaction chamber with a moving sheet and closing after separation sheet from the rarefaction chamber when the device is in stacking mode.

In this embodiment of the device, each section of the rarefaction chamber can be equipped with a system for automatically regulating the vacuum acting in the section after it is blocked by a moving sheet, including a volume flow regulator ejected from the air section, connected to the ejector and equipped with a control device containing a pressure sensor connected to the internal cavity sections, a volumetric air flow sensor ejected from the section, a correction unit and a software device in which the input is connected to the sensor eniya, and an output - to one of the inputs of the correction unit, the second input of which is connected to the sensor volumetric flow rate of air ejected from the section, and an output - to a controller of said flow.

At the same time, in this embodiment of the device, in each section of its rarefaction chamber, the exhaust pipe can adjoin the upper wall, in which an inlet window can be made, communicating the internal cavity of the section with the exhaust pipe, and an ejector is located in front of the specified inlet window in the direction of the air flow in an outlet pipe, inside of which there is a two-position valve, made with the possibility of blocking the inlet window of the upper wall at the initial closed position and the possibility of moving to the open position with the opening of the indicated inlet window and simultaneously blocking the air passage from the ejector outlet to the outlet nozzle outlet and ensuring the air passage from the ejector outlet to the rarefaction chamber section through the inlet window of its upper wall, the two-position valves located in the outlet pipes of the rarefaction chamber sections are provided with a drive made with the possibility of their simultaneous opening before separation of the sheet from the vacuum chamber and closing after the specified separation.

In addition, in this embodiment of the device, in each section of the rarefaction chamber, the transverse side walls can be configured to interact with the moving sheet by rotating these walls relative to the upper wall of the section in the direction of movement of the sheet, and the longitudinal side walls can be configured to interact with the moving a sheet with a fitting to their lower ends of the surface of the specified sheet, while the transverse side walls of the section can be spring-loaded relative to its upper wall with the possibility x return along with the longitudinal side walls of the section to its original position after tearing the sheet from the vacuum chamber or after it leaves the last and in each transverse side wall of the section separating two adjacent sections in each longitudinal row of sections of the vacuum chamber, a bypass window can be made and the shutoff valve of each two adjacent sections in each specified row of sections of the vacuum chamber can be configured to overlap the specified bypass window in the initial closed position and the possibility of it opening when the valve is in the open position.

In this case, the lower end part of the rarefaction chamber of this device, interacting with the moving sheet, can be made of a material having a small coefficient of friction, for example, fluoroplastic.

The invention is illustrated by drawings, which depict:

figure 1 is a longitudinal section of a device according to the first embodiment;

figure 2 is a section aa in figure 1;

figure 3 - the ejector of the vacuum chamber, made in the form of a blade fan;

figure 4 - the ejector of the vacuum chamber, made in the form of a jet vacuum pump;

figure 5 is the same with an adjustable choke in the supply line of the pump;

figure 6 is a schematic diagram of a control system for the shutoff valves of the sections of the vacuum chamber;

7 is a schematic diagram of a system for automatically controlling the vacuum above a moving sheet by changing the volumetric flow rate of air ejected from the vacuum chamber;

on Fig is a schematic diagram of a system for automatically controlling the vacuum above a moving sheet by changing the volumetric flow rate of air bypassed into the air collector from the environment;

Figures 9 and 10 show variants of an input device for a predetermined volumetric flow rate of air through a fan to a control device of an air manifold bypass valve actuator;

figure 11 is a schematic diagram of a combined system for automatically controlling the vacuum above a moving sheet by changing the volumetric flow rate of air passed into the air collector from the environment, and the volumetric flow rate of air through the fan;

in Fig.12 is a variant of the sensor volumetric flow rate of air passing through the ejector of the rarefaction chamber;

in Fig.13 is a longitudinal section of a device equipped with a system for reversing the flow of air from the outlet of the ejector in the section of the vacuum chamber;

in Fig.14 is a view along arrow B in Fig.13;

on Fig is a longitudinal section of a device equipped with a system for reversing the flow of air from the outlet of the ejector to the air manifold;

in Fig.16 is a fragment of the rarefaction chamber of a device having movable side walls;

on Fig is a longitudinal section of a device according to the second embodiment;

on Fig - section bb In Fig;

on Fig is a schematic diagram of a control system shut-off valves of adjacent sections of the vacuum chamber;

in Fig.20 is a schematic diagram of a system for automatically controlling the vacuum in each of the sections of the vacuum chamber;

on Fig is a longitudinal section of a device in which the sections of the rarefaction chamber are equipped with a system for reversing the air flow from the outlet of the ejector to the section;

in Fig.22 is a section GG in Fig.21;

in Fig.23 is a fragment of the rarefaction chamber of a device having movable side walls.

A device for transporting and stacking sheets contains a mechanism for feeding sheets, made, for example, in the form of a feed conveyor 1 (Fig. 1), a vacuum chamber 2, equipped with a drive conveyor 3 (for example, belt, roller, etc.) with a drive 4 and a reducer 5, an air manifold 6 with an exhaust pipe 7 located above the vacuum chamber 2, an ejector 8 connected to the exhaust pipe 7, and a lifting table 9 for laying sheets located under the vacuum chamber 2 and provided with a front 10 and rear 11 stops. While the rarefaction chamber 2 is made in the form of at least one longitudinal relative to the direction of movement of the sheet of a number of sections 12, each of which has two lateral walls 13 and two longitudinal 14 (FIG. 2) relative to the indicated direction and the upper wall covering them 15 with an outlet window 16 communicating the internal cavity of the section with the air manifold 6, and is equipped with a shut-off valve 17 mounted on its upper wall 15 and configured to overlap in the initial closed position of the outlet window 16 of the latter and the possibility of opening it when the valve is in the open position. The ejector 8 can be made, for example, in the form of a blade fan 18 (figure 3), equipped with a drive 19, or in the form of a jet vacuum pump containing a housing 20 (figure 4) with an internal mixing chamber 21, communicating with the exhaust pipe 7, an active jet-forming nozzle 22 and a diffuser 23. The nozzle 22 is provided with a supply line 24, which can be connected to a compressor 25 with a drive 26 included in the design of the proposed device, or to a common (workshop, factory, etc.) compressed air line. To provide the ability to control the performance of the ejector (volumetric flow Q of air ejected through the exhaust pipe 7 of the air collector 6), the drive 19 (Fig. 3) of the fan 18 can be equipped with a speed controller 27 of the rotor speed of the fan, and the drive 26 (Fig. 4) of the compressor 25 can be equipped with a regulator 28 for the speed of rotation of the working shaft of the compressor, with a change in which the volumetric supply of compressed air at the compressor output changes, which leads to a change in the velocity of the ejection jet formed by the nozzle 22, and , accordingly, to a change in the volumetric flow rate Q of the air ejected by the specified stream from the nozzle 7 to the diffuser 23. However, when using an jet pump as an ejector to regulate the air flow Q through the ejector 8, an adjustable throttle can be used instead of the volumetric regulator 28 of the compressor 25 29 (figure 5), equipped with a drive 30 and connected to the last regulator 31 of the flow area of the throttle 29. When you change the specified area changes the volumetric flow rate of compressed air through the nozzle 22, and together with and it varies the speed of ejecting jet that ultimately leads to a change in the volumetric flow rate Q of air ejected from the nozzle 7 in the diffuser 23.

Shut-off valves 17 (Fig. 1) of sections 12 of each transverse row of sections of the vacuum chamber 2 can be made in the form of rotary dampers mounted on a common axis of rotation 32 (Fig. 2) equipped with a drive 33. Said actuator can be equipped with a sensor 34 (Fig. .2 and 6) mounted on the rear edge of the sheet along the edge of the indicated row of sections 12 and configured to generate a signal in its output line 35 at the entrance to the zone of its location of the moving sheet. The output line 35 of the sensor 34 is connected to the drive 33 through a switch 36 provided with a control drive 37, and a sensor 38 is mounted on the front edge of the sheet of the indicated row of sections, configured to generate a signal in its output line 39 when leaving the rear the edges of the moving sheet. Moreover, each drive 37 installed in one of the transverse rows of sections 12 of the rarefaction chamber 2 has two control inputs, one of which is connected via a switch 40 to the output line 39 of the sensor 38 mounted on the front edge of this row of sections 12, and the second to the output line 39 of the sensor 38 mounted on the front edge of the next sheet along the transverse row of sections 12 of the rarefaction chamber 2. Each two sensors 34 and 38 installed on the border of two adjacent transverse rows of sections 12 of the rarefaction chamber 2 can be combined into yn combined effect sensor, provided with two output lines - 35 and 39 and capable of generating a signal in line 35 at the entrance to the zone plate and its location in the line 39 - at the exit of the sheet from its location area. To improve the efficiency of controlling the device, the switches 40 can be connected to each other by a common bracket 41, enabling them to be simultaneously turned on or off. When the device is in sheet transport mode, a transfer conveyor 42 or the next device for stacking and transporting sheets can be installed next to it.

To reduce energy consumption for the operation of the ejector by maintaining at an optimal level the magnitude of the lifting force holding the moving sheet under the rarefaction chamber 2, the device can be equipped with an automatic control system for the given optimal program of the rarefaction value in sections 12 of the rarefaction chamber 2, overlapped by the moving sheet. This system can be made in the form of a regulator 43 (Fig. 7) of the volumetric flow rate Q of air through an ejector 8 provided with a control device 44. When using fan 18 as an ejector 8 (Fig. 3), a speed regulator 27 can be used as a regulator 43 rotation of the rotor of the fan, and when using a jet vacuum pump as an ejector 8 as a regulator 43, a regulator 28 (Fig. 4) of the speed of rotation of the working shaft of the compressor 25 or a regulator 31 (Fig. 5) of the passage area is adjustable about the throttle 29. The control device 44 contains a pressure sensor 45 connected to the internal cavity of the air manifold 6 and configured to register the amount of vacuum in the specified cavity, the sensor 46 of the volumetric flow rate Q of air through the ejector 8 connected to the latter, block 47 of the correction of the specified flow rate Q and a software device 48, in which the input is connected through a converter 49 to a pressure sensor 45, and the output is connected to one of the inputs of the correction unit 47, the second input of which is connected through a converter 50 to a sensor 46, and the output od - through the converter 51 to the controller 43.

When using fan 18 as an ejector 8 (Fig. 3), the automatic rarefaction control system over a moving sheet can also be implemented in two other ways. According to the first of them, it may contain at least one adjustable bypass valve 52 (Fig. 1) mounted on the air manifold 6 with the possibility of changing the passage area of the bypass port 53 made in the specified manifold and equipped with an adjustable actuator 54 (Fig. .2) with a control device 55 (Fig. 8) containing a pressure sensor 45 connected to the internal cavity of the air manifold 6, a rarefaction correction unit 56 in the air manifold 6, and a software device 57, the input of which is connected to the input device 58 and in the last value of the volumetric flow rate Q of air ejected by the fan 18 from the air manifold 6 through the exhaust pipe 7, and the output to one of the inputs of the correction unit 56, the second input of which is connected via a converter 60 to an adjustable drive 54. In this case, the device 58 can be made in the form of a device for manual input of the Q value into a software device 57, made, for example, in the form of a control device 55 of a scale 62 installed on the housing 61 (Fig. 9) with digital or level (I, II, III, etc.) divisions reflecting quantities inu Q, and a movable set handle 63 with a pointer 64 of a set value Q, while the handle 63 is connected to a software device 57 with the possibility of changing the last value Q when moving the handle 63 in accordance with the change in the position of its pointer 64 on the scale 62. Together with the device 58 can be made in the form of a sensor 46 (figure 10) of the volumetric flow rate Q of air ejected by the fan through the exhaust pipe 7 of the air collector 6, and a converter 65 through which the sensor 46 is connected to the software device 57. According to the second, To an option, said automatic control system may comprise an adjustable bypass valve 52 (Fig. 11) mounted on the air manifold 6 with the possibility of passing into the last air from the environment and equipped with an adjustable drive 54, a regulator 43 of the air volume flow Q through the fan 18 and the control device 66 comprising a pressure sensor 45 connected to an internal cavity of the air manifold 6, a volume flow sensor Q connected to a fan 18, a rarefaction correction unit 56 above a moving sheet (in sections 12 of the rarefaction chamber 2, covered by a moving sheet), Q flow correction unit 47 and software device 67, in which one input is connected via pressure transducer 49 to pressure sensor 45, and the second input is connected through Q converter 46 to Q flow sensor 46, one output - to the input of the rarefaction correction unit 56 and the second output to the input of the flow correction unit 47 of Q. In this case, the rarefaction correction unit 56 has a second input connected via pressure transducer 59 to pressure sensor 45, and an output connected through converter 60 to an adjustable drive 54 p the bypass valve 52, and the flow rate correction block Q has a second input connected via a converter 50 to a flow sensor 46 Q, and an output connected through a converter 51 to a controller 43.

In the presented variants of the automatic control system, the sensor 46 (Figs. 7, 10 and 11) of the volume flow Q can be made in the form of a sensor for rotational speed of the fan rotor 18 (Fig. 3) or the working shaft of the compressor 25 (Fig. 4) or in the form of a sensor the cross-sectional area of the inductor 29 (Fig. 5) and can be connected respectively to the drive 19 of the fan 18, or to the drive 26 of the compressor 25, or to the drive 30 of the inductor 29. In this case, the converters 50 and 65 (Figs. 7, 10 and 11) made with the possibility of converting the current value of the speed of rotation of the roto RA of the fan 18 or the working shaft of the compressor 25 or the current value of the flow area of the throttle 29 to the current value of the flow rate Q through the ejector 8. At the same time, the sensor 46 can be made in the form of an air flow velocity sensor installed in the outlet pipe 7 (Fig. 12) before the ejector 8. In this case, the transducers 50 and 65 are configured to convert the current value of the specified speed to the current value of the flow rate Q of air through the ejector 8.

In addition, in the presented embodiments of the automatic rarefaction control system over a moving sheet, each of the software devices 48 (Fig. 7), 57 (Fig. 8) and 67 (Fig. 11) can be connected via transducers 68 to sensors 34 (Fig. 6 ) the position of the sheet to enable this device to obtain information on the value of the current values of X ₁ , X ₂ , ... X _{m of the} discrete stroke X (Fig. 1) of the sheet, measured from the front along the edge of the rarefaction chamber 2 to the sensor 34, the location of which on the vacuum chamber corresponds to x value. Thus, the value of the sheet travel X ₁ is detected by the first sensor 34 in the direction of the sheet, the size of the sheet X ₂ is recorded by the second sensor 34 in the direction of the sheet, etc. The maximum value of the sheet travel X _m is recorded by the last sensor 34 in the direction of the sheet, where the serial number m of the parameter X is equal to the number of transverse rows of sections 12 available in the vacuum chamber 2. Moreover, each of these software devices 48, 57 and 67 can be executed with to input therein the specified design parameters k _1, k ₂ ... k _n of the vacuum chamber 2 having an impact on the optimal value of the vacuum above the moving sheet (e.g., its length, width, number of sections 12, their length and width, coefficient tre the surface of the material from which the lower end of the rarefaction chamber is made, which interacts with the surface of a moving sheet, etc.), as well as geometric dimensions (width h, length 1 and thickness δ) of transported and stacked sheets, specific gravity γ of their material and coefficient friction μ of the surface and the velocity V of motion of the conveyor 3. However, programming devices 57 and 67 may also be made to input to each of them a predetermined value of the initial (original) of the area S ₀ of the bypass passage section klapa and 52, corresponding to the beginning of the movement of the sheet under the rarefaction chamber 2. At the same time, the software device 48 (Fig. 7) is configured to generate a signal at its output that reflects the optimum value of the volumetric flow rate Q of air ejected from the vacuum chamber using the ejector 8, a software device 57 (Fig. 8) - with the possibility of generating at its output a signal reflecting the optimal value of the rarefaction p in sections 12 of the rarefaction chamber 2, blocked by a moving sheet and communicating with the air collector 6, and the software equipment 67 (Fig. 11) - with the possibility of generating at one of its outputs a signal reflecting the optimal value of the specified vacuum p and with the possibility of generating at its second output a signal reflecting the optimal value of the specified flow Q. These optimal values of the parameters p and Q can be set for each of the current values X ₁ , X ₂ , ... X _{m of the} discrete path X (Fig. 1) of the sheet under the rarefaction chamber 2, detected by the sheet position sensors 34. In this case, the optimal current values of the parameters p and Q relative to the current value of the discrete path X of the sheet can be set based on the conditions for ensuring the required value of the device performance at the lowest energy consumption for its operation and the exclusion of damage to sheets during their transportation and stacking and premature separation of sheets from the vacuum chamber.

To accelerate the separation of the sheet from the vacuum chamber 2 in order to increase the productivity of the device, it can be equipped with a system for reversing the air flow at the outlet of the ejector 8 (for example, fan 18) (Figs. 13 and 14), made in the form of an air duct 69 with an outlet pipe 70 located before the first transverse row of sections 12 of the rarefaction chamber 2 along the sheet, and each section 12 in the indicated row can be made with an inlet window 71 for the passage of air, communicating its internal cavity with the air duct 69, in which on-off valve 72, configured to block the inlet windows 71 of the sections 12 of the specified row in the initial closed position of the valve and the possibility of moving into the open position with the opening of the inlet windows 71 and simultaneously blocking the air passage from the air duct 69 to the outlet of its exhaust pipe 70 and providing an air passage from the air duct 69 in section 12 of the indicated row through their inlet windows 71. In this case, the fan 18 communicates with the air outlet 69 with the air outlet and is installed near the first downstream sheet transverse row of sections 12 the vacuum chamber 2 and the valve 72 may be configured as a rotary damper with a rotation axis 73 provided with a drive 74.

In another embodiment of the system for reversing the air flow at the outlet of the ejector 8 (for example, fan 18) (Fig. 15), the device can be equipped with an outlet pipe 75 connected to the outlet of the ejector, which is installed close to the outlet of the collector 6, and in this device the collector 6 can be made with an inlet window 76 for the passage of air, communicating the internal cavity of the manifold 6 with the pipe 75. Inside the pipe 75 there is a two-position valve 77 configured to overlap the intake window 76 of the collector 6 in the original closed m position and the ability to transfer to an open position with the opening of the inlet port 76 and simultaneously overlapping the passage of air from the output of the fan 18 at exit outlet 75 and ensuring the passage of air from the fan outlet 18 to the collector 6 via the inlet port 76 of the latter. The valve 77 may be made in the form of a rotary damper mounted on the axis of rotation 78, equipped with an actuator 79.

To reduce energy consumption for the operation of the ejector 8 by increasing the degree of tightness of the sections 12, overlapped by a moving sheet, in each section 12 two transverse side walls 13 (Fig. 16) can be made with the possibility of their interaction with the moving sheet with rotation of these walls relative to the upper wall 15 in the direction of movement of the sheet, and the longitudinal side walls 14 can be made with the possibility of interaction with the moving sheet with the fitting of their lower ends of the surface of the specified sheet. In this case, the longitudinal walls 14 can be made of a material capable of changing its geometric shape with its subsequent restoration, for example, from elastic rubber, fabric, polymer film, rubberized fabric, etc., and the transverse walls 13 can be spring-loaded relative to the upper wall 15 with the possibility of their return using the springs 80 together with the longitudinal walls 14 to their original position.

In another embodiment of the proposed device, each section 12 (Fig. 17) of the rarefaction chamber 2 is equipped with its own ejector 8, made, for example, in the form of a blade fan 18 with a drive 19 or in the form of a jet vacuum pump, shown in figures 4 and 5, and the upper wall 15 of each section 12 is made with an external outlet pipe 81 connected to the ejector. Moreover, in each longitudinal row of sections 12 of the rarefaction chamber 2, each two adjacent sections 12 are equipped with a shut-off valve 82 installed between them and configured to separate the sections from each other in its initial closed position and the sections being able to communicate with each other in its open position. The shut-off valve 82 can be mounted on the transverse wall 13 separating these adjacent sections 12, and can be made in the form of a rotary valve. However, the role of the shut-off valve 82 can be performed by the transverse wall 13 itself, made in the form of a rotary damper 82, as shown in Fig. 17. Moreover, in each two transverse adjacent rows of sections 12 of the rarefaction chamber, shut-off valves 82 of adjacent sections 12, made in the form of rotary dampers, are installed on a common axis of rotation 83 (Fig. 18), equipped with a drive 84 with a sensor 34 for the position of the sheet mounted on the rear the sheet moving along the edge of the second of these rows along the sheet (Fig. 19) and equipped with an output line 35 connected to the drive 84 through the switch 85. To improve the efficiency of the device control, the switches 85 can be fixed to a common rail 86, The ability to turn them on or off simultaneously.

To reduce energy costs for the operation of the ejectors of the rarefaction chamber by maintaining at an optimal level the lifting force holding the moving sheet under the rarefaction chamber 2, any i-th (i = 1,2,3, ... N, where N is equal to the number of sections 12 in the rarefaction chamber) section 12 of the latter in this device can be equipped with an automatic control system for a given optimal program of the rarefaction value p _i acting in it after it is blocked by a moving sheet. The specified system may include a regulator 43 (Fig. 20) connected to the ejector 8 of the volumetric flow rate Q _{i of} air ejected from section 12 using the specified ejector, and a control device 87, similar to the control device 44 shown in Fig. 7, and different from the last the fact that its software device 88 is not connected to the sheet position sensors 34 and is configured to input design parameters k _i1 , k _i2 ... k _{it of the} i-th section 12 of the rarefaction chamber, where the maximum numerical serial number t of the parameter k _i equal to the number k section structural parameters that affect the optimal value of the vacuum created in it. The indicated structural parameters of the section include, for example, its length, width, height; coefficient of friction of the lower end of the section, etc. To reduce energy consumption for the operation of the ejector 8 in each section 12 of the rarefaction chamber in the input line 89 of the controller 43 connecting the latter to the control device 87, a switch 90 is installed, equipped with a control drive 91 connected to a sheet position sensor 34 mounted on the back along the sheet the edge of the transverse row of sections 12 of the rarefaction chamber 2, in which this section 12 is located.

To accelerate the separation of the sheet from the rarefaction chamber 2 in order to improve the performance of this device in each section 12 of its rarefaction chamber, the exhaust pipe 81 (Fig. 21) is adjacent to the upper wall 15, in which an inlet 92 is made, communicating the internal cavity of the section with the exhaust pipe 81 in which the on-off valve 93 is placed, wherein an ejector 8 (for example, a fan 18) is placed in the exhaust pipe 81 in front of the inlet 92 in the direction of the air flow in the pipe. In its initial closed position, the valve 93 closes the inlet 92 of the upper wall 15, and when it is moved to the open position, it opens the hole 92 and simultaneously blocks the air passage from the outlet of the fan 8 to the outlet of the outlet pipe 81 and allows air to pass from the outlet of the fan 8 to the section 12 through the inlet 92 in its upper wall 15. On-off valves 93 can be made in the form of rotary dampers. While the valves 93 of each transverse row of sections 12 of the rarefaction chamber 2 can be installed on a common axis of rotation 94 (Fig.22). The axis of rotation 94 of the valves 93 of all the transverse rows of sections 12 of the rarefaction chamber can be equipped with a common rotary drive 95, the output shaft of which can have a gear or belt connection with the axis of rotation 94. When using a gear connection, the drive gear 96 is installed on the output shaft of the actuator 95, and at the ends of the axes of rotation 94 - driven gears 97, interacting with a movable gear rack 98, receiving reciprocating movement from the pinion gear 96, and when using a belt connection at the ends of this rotation 94 instead of gears 97, pulleys are mounted, covered by a common belt, while the output drive shaft of the drive 95 is connected to one of the axes of rotation 94, the pulley of which acts as a driving pulley, transmitting through the belt the movement of all other pulleys of the axis of rotation 94. It is also possible to use the movement of the valves 93 of the actuator 95 reciprocating action, the output power rod of which is connected to a long gear rack 98, interacting with gears 97, or with a short gear rack (not shown), interacting with with teeth with a drive gear mounted on the end of one of the axes of rotation 94, each of which is equipped with a pulley mounted on its end, while the pulleys of all axes of rotation 94 are surrounded by one belt through which the rotary movement from the drive gear is transmitted to all the pulleys and connected to them axes of rotation 94. With any of the transmission variants presented, it is possible to simultaneously transfer valves 93 of all sections 12 of the rarefaction chamber 2 from a closed to an open position and vice versa.

To reduce energy costs for the operation of the ejectors 8 by increasing the degree of tightness of the sections 12 covered by a moving sheet, as in the first embodiment of the device (Fig. 16), in this embodiment, in each section 12 of the rarefaction chamber 2, the transverse side walls 13 (Fig. .23) can be made with the possibility of their interaction with the moving sheet with the rotation of these walls relative to the upper wall 15 of the section in the direction of movement of the sheet, and the longitudinal side walls 14 can be made of a material that can change its geometrical form when interacting with the walls of said moving sheet (for example of elastic rubber, cloth, polymeric film, rubberized cloth, etc.) to enable them to tightly fit the bottom end surface of said sheet. The walls 13 are provided with springs 80 for returning to the initial position together with the walls 14, and in each longitudinal row of sections 12 of the rarefaction chamber 2, a bypass window 99 is made in the side wall 13, which is closed by a shut-off valve 82 in its initial position, while the wall 13 and valve 82 can rotate about one axis.

In the presented variants of the proposed device, each of the drives 74 (Fig.13), 79 (Fig.15) and 95 (Fig.21) in the system for reversing the air flow at the outlet of the ejector 8 (for example, fan 18) can be connected, at least , to one of the sheet position sensors 34 through the switch 100, while the location of the sensor 34 on the vacuum chamber 2, to which each of these drives is connected, is determined by the length of the sheet, measured in the direction of its movement. With the largest length of stacked sheets equal to or close to the length of the rarefaction chamber 2, measured in the direction of movement of the sheet, the last sensor 34 is connected to the drive 74, 79 or 95, and when laying the shortest sheets, the length of which is equal to or close to the length of the first two first along the sheet sections 12, measured in the direction of movement of the sheet, with the specified drive is connected to the sensor 34 located between the second and third along the movement of the sheet transverse rows of sections 12. If necessary, stacking sheets of sheets, having an intermediate length, one of the sensors 34 located between these extreme sensors can be attached to the actuator 74, 79, or 95. When the device is in sheet stacking mode using the switch 100, the sensor 34 is connected to the actuator 74, 79 or 95, the location of which on the vacuum chamber 2 corresponds to the length of the sheets to be stacked, and the remaining sensors 34 are disconnected from the specified device using the switch 100. When working devices in the sheet transport mode, the system for reversing the air flow at the ejector outlet is blocked by turning off all switches 100.

Each of the actuators 54 (Fig.2), 30 (Fig.5), 33 (Fig.6), 74 (Fig.13), 79 (Fig.15), 84 (Fig.18) and 95 (Fig.21) ) can be performed, for example, in the form of a mechanical, electrical, electromechanical, electromagnetic, hydraulic, pneumatic or other type of drive, and as sensors 34 (6) and 38 the position of the moving sheet can be used, for example, mechanical, electrical, electromagnetic, electromechanical, optical (light), ultrasonic, pneumatic, etc. sensors. In this case, the valves 52 (Fig.2), 17, 72 (Fig.13), 77 (Fig.15), 82 (Fig.19) and 93 (Fig.21) can be equipped with return springs (not shown), returning them to their original closed position. In the presented devices, there are other possible versions of the control system for the position of the valves 17, 72, 77, 82 and 93, different from the options shown in Fig.6, 13, 15, 19 and 21, and based on known technical solutions used in systems automatic control and regulation of various devices, machines and mechanisms. In this case, the specific execution of the control system for these valves is determined mainly by the material (metal, plywood, plastic, cardboard, etc.) of the stacked and transported sheets, as well as the selected type of actuators of these valves and the selected type of sensors 34 and 38 of the position of the moving sheet interacting with valve actuators. Any of the actuators 33, 74, 79, 84 and 95 of these valves may be equipped with a control device connected to sensors 34 and 38 (not shown).

For ease of maintenance of the device, the switches 40 (Fig.6), 85 (Fig.19) and 100 (Fig.13, 15 and 21) can be placed on its control panel, and to reduce energy consumption on the conveyor drive 3 (Fig.2 and 18) by reducing the frictional force between the moving sheet and the lower end part 101 of the rarefaction chamber 2, said end part of the latter can be made of a material having a small coefficient of friction, for example, fluoroplastic.

In any of the presented device variants, the front stop 10 (Fig. 17) of the lifting table 9 can be made with the possibility of adjusting its position in the direction of movement of the sheet, if necessary, laying on the table 9 sheets of different lengths. For this purpose, the stop 10 can be equipped with a nut 102, which is moved along the guide 103, and the actuator 104 with a screw 105 interacting with the nut 102. When the actuator 104 is turned on, its screw 105 moves the nut 102 together with the stop 10 towards the rear table stop 11 - when decreasing the length of stacked sheets or in the opposite direction - with an increase in the specified length.

The device operates as follows.

In the initial position of the device operating in the mode of stacking sheets (1), the distance between the front 10 and rear 11 stops of the lifting table 9 is set equal to the length of the stacked sheets by adjusting the position of the stop 10 using the actuator 104 (Fig.17), and in each of the systems for reversing the air flow at the outlet of the ejector 8 (for example, fan 18) (Figs. 13-15), one of the switches 100 is installed, which is installed in the output line of the sensor 34 located near the front stop 10 of the lifting table 9. At the same time, the switches 40 (Fig.6) and remained Power switches 100 are turned off, switches 36 (FIG. 6) are turned on, and valves 17 (FIG. 1) and 72 (FIG. 13) or 77 (FIG. 15) are closed.

After turning on the ejector 8 (Fig. 1) and the conveyor 3, the sheet is conveyed by the conveyor 1 under the rarefaction chamber 2. At the moment the moving sheet covers the first in the direction of the transverse row of sections 12 of the rarefaction chamber, the sensor 34 (Fig. 6) is installed in the rear the movement of the sheet to the edge of the indicated row of sections 12, generates a signal arriving along the output line 35 to the actuator 33, which puts the shut-off valves 17 of the given row of sections 12 into the open position. The shut-off valves 17 of all the other transverse rows of the sections 12 of the rarefaction chamber open separately. Moreover, in any position of the sheet occupied by it during movement under the rarefaction chamber, the air inside the sections 12 covered by the moving sheet is ejected from them using an ejector 8 through the outlet windows 16 of the upper walls 15 of these sections, as a result of which inside these sections a vacuum is formed, and a pressure drop occurs on the moving sheet, creating a lifting force that holds the sheet under the vacuum chamber 2 and presses it to the conveyor 3, which moves the sheet under the specified chamber.

After depressurization of the first in the direction of movement of the sheet of the transverse row of sections 12 of the rarefaction chamber 2, when the trailing edge of the sheet exits under the specified row of sections 12, the rarefaction inside all sections 12 of the rarefaction chamber 2 falls and the sheet, under the action of gravity, breaks away from the rarefaction chamber 2 and is stacked on table 9. In a device equipped with a system for reversing the air flow at the outlet of the fan 18 (Fig.13-15), when the leading edge of the moving sheet reaches the zone of the sensor 34 with the switch 100 on, the specified sensor generates a signal to the actuator 74 (Fig.13), which translates the valve 72 into the open position, or to the actuator 79 (Fig.15), which translates the valve 77 into the open position, which leads to a rapid pressure drop in the sections 12 of the rarefaction chamber, thanks to which accelerates the separation of the sheet from the vacuum chamber 2, which helps to increase the productivity of the device.

After the sheet is detached from the rarefaction chamber 2, the signals from the sensors 34 cease and the actuators 33 and 74 or 79 return to their original position and, together with them, the valves 17 and 72 or 77 return to their original closed position. The subsequent sheets are laid in the described sequence. As a set of stacks of sheets, the table 9 periodically lowers automatically.

In the initial position of the device operating in the sheet transport mode, the switches 36 and 40 (Fig. 6) are turned on, the switches 100 (Fig. 13 and 15) are turned off, and the valves 17 (Fig. 1) and 72 (Fig. 13) or 77 (Fig. 15) are closed. After the ejector 8 and conveyors 3 and 42 are turned on, the sheet is fed by the conveyor 1 under the rarefaction chamber 2 with the shutters 17 sections 12 of the rarefaction chamber being opened in the above-described order, creating a lifting force on the sheet by holding it under the rarefaction chamber 2 and pressing the sheet to the conveyor 3, moving the latter to the side of the conveyor 42. When the rear edge of the sheet leaves the zone of the sensor 38 (Fig.6), installed in front of the first along the sheet along the transverse row of sections 12 of the rarefaction chamber , the specified sensor generates a signal coming through the output line 39 to the control actuator 37, which turns off the switch 36. In this case, the signal from the sensor 34 is interrupted and the actuator 33 returns to its original position and with it the shut-off valves 17 of the indicated series of sections return to their original closed position 12, which eliminates the depressurization of the air manifold 6 and the loss of vacuum in the remaining sections 12 of the vacuum chamber, overlapped by a moving sheet, when the rear end of the latter leaves the first transverse of a number of sections 12. When the rear edge of the sheet leaves the zone of the next sensor 38, the latter generates a signal that is supplied via the output line 39 to the second control input of the specified drive 37, which returns the switch 36 to its initial on position. In the same order, the shut-off valves 17 are sequentially closed. and the switches 36 of the remaining transverse rows of sections 12 return to their original position during the movement of the sheet under the rarefaction chamber 2 with its subsequent transfer to the conveyor 42 or adjacent Equipment for laying and transporting sheets. Transportation of subsequent sheets is carried out in the described sequence. If necessary, transport sheets from the table 9 include an ejector 8 and conveyors 3 and 42 and raise the table 9 with a stack of sheets laid on it. When the upper sheet of the foot approaches the rarefaction chamber 2, the sensors 34 generate signals arriving at the actuators 33, opening the valves 17, after which a vacuum is created in sections 12 of the rarefaction chamber 2, which are blocked from below by the sheet, attracting the sheet to the conveyor belts 3, which transfers the sheet to conveyor 42. In the process of moving the sheet under the vacuum chamber, the valves 17 are sequentially closed in the same manner as when transporting sheets from the conveyor 1 to the conveyor 42.

When the device is operating both in the stacking mode and in the sheet transport mode with an increase in the discrete path X (Fig. 1) of the sheet during its movement under the rarefaction chamber 2, the total volume of the internal cavities of the sections 12 of the last and the total area of the slots between the sheet and the lower end of the chamber rarefaction increase. As a result of this, with insufficient performance of the ejector 8, the rarefaction p inside the air manifold 6 and inside the sections 12 of the rarefaction chamber connected to it by a moving sheet can decrease to a level at which the sheet can come off the vacuum chamber ahead of time. With excessive productivity of the ejector 8, the indicated rarefaction p, on the contrary, may turn out to be excessively high, and at the same time, the energy consumption for the operation of the ejector will turn out to be unreasonably high and, at the same time, the force of pressing the sheet against the drives of the conveyor 3 will increase beyond the necessary level, which will cause excessively high friction of the sheet on the lower end of the chamber rarefaction and the associated increased energy consumption for the drive of the conveyor 3 and can also lead to the appearance of residual deformations of sheets (especially thin sheets) and nats x surface. To eliminate these negative aspects in the operation of the device, the current value of the rarefaction p during the movement of the sheet under the rarefaction chamber can be automatically adjusted depending on the current value of the discrete stroke X of the sheet, maintaining the specified optimal current values p _{(opt) 1} , p _{(opt ) 2} , ... p _{(opt) m of the} indicated rarefaction, corresponding to the current values of X ₁ , X ₂ , ... X _{m of the} discrete sheet stroke and providing the least energy consumption for the operation of the ejector 8 and conveyor 3 with the exception of damage sheets and their premature separation from the vacuum chamber. Maintaining the optimal value of the rarefaction p during the operation of the device can be achieved by adjusting the volumetric flow rate Q of air ejected using the ejector 8 from sections 12 of the rarefaction chamber 2, covered by a moving sheet. Regulation of the flow rate Q can be performed using the controller 43 (Fig. 7) and its control device 44, the software device 48 of which receives information about the current value of the discrete path X of the sheet from the sensors 34 through the transducers 68 and about the current value of the rarefaction p - from the sensor 45 through the transducer 49. In the software device 48, the received information is processed according to a given program and the optimal current value of p Ashod Q as a function of a number of the above parameters

Q _(opt) = f (k ₁ , k ₂ , ... k _n , p, X, h, l, δ, γ, μ V).

From the output of the software device 48, information about the value of Q _{(opt) is} fed to the input of the correction unit 47, through the second input of which information about the current value of flow Q from the sensor 46 through the converter 50 is received. In the correction unit 47, the current value of the flow Q is compared with its optimal current value Q _(opt) and after comparison, at the output of the indicated block, a correction signal Δ Q is generated, which reflects the difference of the indicated values. The signal Δ Q through the Converter 51 comes from the correction unit 47 to the controller 43, which sets the performance of the ejector 8 at a level that maintains the current value of the flow rate Q of the air ejected from sections 12 of the rarefaction chamber 2 at its optimal level Q _(opt) . In this case, with an increase in the current value of the discrete stroke X of the sheet as it moves under the rarefaction chamber 2, the control device 44 with the regulator 43 increase the current value of the flow rate Q to maintain the current value of the value of the rarefaction p acting on the moving sheet p at a given optimal level p _(opt) .

When using fan 18 as an ejector 8, maintaining the optimal value of the rarefaction p during the operation of the device can also be carried out in two other ways. According to the first of them, the rarefaction p is maintained at the optimum level p _(opt) by adjusting the area S of the passage section of the bypass valve 52 (Fig. 8) using the actuator 54, which receives control signals from the control device 55. In this case, the latter is supplied to the software device 57 information about the current value of the discrete path X of the sheet from the sensors 34 through the transducers 68. However, the volumetric flow rate Q of the air ejected through the fan 18 is inputted to the software device 57 using the device 58 This value of the flow rate Q can be entered into the software device 57 in advance (when setting up the proposed device before it is put into operation) using the handle 63 (Fig. 9) of the manual input device, the pointer 64 of which is set opposite the digital or level value Q on a scale 62, corresponding to actual fan performance 18. This input method Q is convenient to use when the value of Q does not change during operation of the device. In the case of a change in the value of Q during operation of the device, its value can be entered into the software device 57 using the sensor 46 (FIG. 10) of the flow rate Q through the converter 65. In the software device 57, the information about the current value of the value Q entered by means of the device 58 is processed according to a given program and according to the processing results, the optimal current rarefaction value p received as the function of a number of parameters

p _(opt) = f (k ₁ , k ₂ , ... k _n , Q, X, h, l, δ, γ, μ, S ₀ , V).

From the output of the software device 57, information about the value of p _{(opt) is} fed to the input of the correction unit 56, through the second input of which information about the current vacuum value p is received from the sensor 45 through the converter 59. In the correction unit 56, the current vacuum value p is compared with its optimal current value p _(opt) and after comparison, a correction signal Δ p is generated at the output of the block, reflecting the difference between the indicated values. Using a converter 60, the signal Δ p is transformed into a control signal Δ S corresponding to the size of the flow area of the valve 52, which should provide the optimal vacuum value p _(opt) over the moving sheet. The signal Δ S is supplied to an adjustable actuator 54, which moves the valve 52 to a position corresponding to the specified area of its bore, providing optimal vacuum p _(opt) . At the same time, as the current value of the discrete path X of the sheet increases as it moves under the rarefaction chamber, a control device 55 with an adjustable actuator 54 reduces the area S of the passage section of the valve 52 to maintain the vacuum p at an optimal level p _(opt) .

According to the second method, the rarefaction of p over a moving sheet when using fan 18 as an ejector 8 is maintained during operation of the device at an optimal level due to the combined control of the parameters S and Q. When using this method, the entire period of movement of the sheet under the vacuum chamber is divided into two stages. At the first initial stage of the sheet movement, the vacuum p is maintained at the optimum level p _(opt) by adjusting the area S of the bypass valve 52 (Fig. 11) using the actuator 54, which receives control signals from the control device 66, the software device 67 of which receives information about the current the value of the discrete stroke X of the sheet from the sensors 34 through the transducers 68 and the current value of the air flow rate Q from the sensor 46 through the converter 65. In the software device 67, the received information is processed by This program and the processing results calculate the optimal current vacuum value received at the output of the device as a function of a number of parameters

p _(opt) = f (k ₁ , k ₂ , ... k _n , Q, X, h, l, δ, γ, μ, S ₀ , V).

In the correction block 56, the current rarefaction p, coming from the sensor 45 through the converter 59, is compared with its optimal value p _(opt) and, after comparison, the correction signal Δ p is generated at the block output and transmitted through the converter 60 to an adjustable actuator 54 that changes the valve position 52 and its area S in accordance with the incoming correction signal Δ S. Moreover, with an increase in the current value of the discrete path X of the sheet as it moves under the rarefaction chamber, the control device 66 with with a driven actuator 54, the area S of the passage section of the valve 52 is reduced, and at the end of the first stage of the sheet movement, after closing the predetermined number of transverse rows of sections 12 of the rarefaction chamber 2, this valve is completely closed. A predetermined number of these rows of sections 12 of the rarefaction chamber is determined theoretically and / or empirically from the condition of ensuring reliable operation of the device without surging fan 18 and at the lowest energy consumption.

In the second stage of sheet movement after closing valve 52, the rarefaction p is maintained at the optimum level p _(opt) by adjusting the volumetric flow rate Q of air through the fan 18 using the controller 43 and control device 66, the software device 67 of which receives information about the current value of the discrete stroke X sheet from the sensors 34 through the transducers 68 and the current value of the rarefaction p - from the sensor 45 through the transducer 49. In the software device 67, the received information is processed and according to the results brabotki computed supplied to the output device optimal current value of the flow rate Q as a function of several parameters

Q _(opt) = f (k ₁ , k ₂ , ... k _n , p, X, h, l, δ, γ, μ, V).

In correction block 47, the current flow rate Q from the sensor 46 through the converter 50 is compared with its optimal value Q _(opt) and, after comparison, the correction signal Δ Q is generated at the output of the block through the converter 51 to the controller 43, which sets the flow Q at the level of Q _(opt) ; providing the exit of rarefaction p to the optimal level p _(opt) . Moreover, with an increase in the current value of the discrete stroke X of the sheet as it moves under the rarefaction chamber, the control device 66 with the regulator 43 increases the current value of the flow rate Q and thereby maintains the current value of the rarefaction p above the sheet at a given optimal level p _(opt) until the end of the movement of the sheet under the vacuum chamber 2.

When using fan 18 as an ejector 8, out of the three presented methods for automatically regulating the rarefaction p, a method is selected that, for given design parameters of the rarefaction chamber, given geometric, weight and frictional indices of the transported and stacked sheets and a given working characteristic of the fan, ensures stable (without fan entry in surge mode and without premature separation of sheets from the vacuum chamber) and the most economical (with the lowest energy ozatratami on the fan drive 18 and conveyor 3) operation.

When changing the parameters h, l, δ, γ and μ of stacked and transported sheets, and / or design parameters k ₁ , k ₂ , ... k _n of rarefaction chamber 2, and / or the size of the initial (initial) area S _{o of the} passage section the bypass valve 52, and / or the speed V of the conveyor 3 in each of the software devices 48 (Fig.7), 57 (Fig.8) and 67 (Fig.11) are introduced new values of these variable parameters when preparing the proposed device for operation.

In the device made with sections 12 of the rarefaction chamber having rotatable transverse side walls 13 (Fig. 16) and elastic longitudinal side walls 14, the sheet interacts with the indicated side walls of sections 12. In doing so, the transverse walls 13 rotate relative to the upper walls 15 sections 12 in the direction of movement of the sheet, and the longitudinal walls 14 enclose the surface of the moving sheet with their lower end, thereby increasing the tightness of the sections 12 of the rarefaction chamber, overlapped by the moving sheet, due to reduced energy consumption for operation of the ejector plate 8. After separation from the vacuum chamber, or after it exits from the chamber 13 of said wall sections 12 and 14 are returned by the springs 80 to its original position.

In another embodiment, the proposed device when it is in the stacking mode of the sheets in the initial position in the system for reversing the air flow at the outlet of the ejectors 8 (for example, fans 18) (Fig. 21), one of the switches 100 is installed, installed in the output line of the sensor 34, located near the front stop 10 of the lifting table 9. In this case, the remaining switches 100 are turned off, the switches 85 (Fig. 19) are turned on, and the valves 82 and 93 are closed.

After turning on the fans 18 and the conveyor 3, the sheet is conveyed by the conveyor 1 under the rarefaction chamber 2. Further, the device operates similarly to the device according to the first embodiment by alternately opening the valves 82 of the transverse rows of sections 12 of the rarefaction chamber using actuators 84 interacting with the sensors 34 to tear off the sheet from the rarefaction chamber and stacking it on a table 9 when the trailing edge of the sheet exits from under the first transverse row of sections 12 of the rarefaction chamber along the movement of the sheet and the valves 82 return to their original rytoe position. In a device equipped with a system for reversing the air flow at the outlet of the fans 18 (Fig. 21), when the leading edge of the sheet reaches the zone of the sensor 34 with the switch 100 turned on, the sensor sends a signal to the actuator 95, which switches the valves 93 to the open position, which leads to a fast the pressure drop in the sections 12 of the rarefaction chamber, thereby accelerating the separation of the sheet from the rarefaction chamber, which helps to increase the productivity of the device. After tearing the sheet from the rarefaction chamber, the specified signal from the sensor 34 stops and the actuator 95, together with the valves 93, returns to its original position. The subsequent sheets are laid in the same sequence.

In the initial position of this variant of the device operating in the sheet transport mode, the switches 85 and 100 are turned off, and the valves 82 and 93 are closed. After the fans 18 and conveyors 3 and 42 are turned on, the sheet is fed by the conveyor 1 under the rarefaction chamber 2 and moved by the conveyor 3 towards the conveyor 42 with the sheet held under the rarefaction chamber by the lifting force created by ejecting air from the sections 12 of the rarefaction chamber by the fans 18.

When the device is operating both in the stacking mode and in the sheet transport mode, the rarefaction p _i inside any i-th section 12 of the rarefaction chamber 2 can be adjusted in automatic mode while maintaining the specified optimal current value p _{i (opt) of the} specified vacuum, which ensures the lowest energy consumption by the operation of the fan 18 of this section and the conveyor 3 with the exception of damage to the sheets and their premature separation from the vacuum chamber. The optimal value of the rarefaction value p _{i (opt) is} maintained by adjusting the volumetric flow rate Q _{i of} air passing through the fan of this section 12 using the controller 43 (Fig. 20) and its control device 87, the software device 88 of which receives information from the sensor 45 about the current value of the rarefaction value p _i . In the software device 88, the obtained information is processed according to a given program and the optimal current value of the flow rate Q _i, which is received as the function of a number of parameters, is received at the device output.

Q _{i (opt)} = f (k _i1 , k _i2 , ... k _im , p _i , h, l, δ, γ, μ, V).

From the output of the software device 88, information about the value of Q _{i (opt) is} supplied to the input of the correction unit 47 and compared with the current value of the value Q _i , information about which is supplied to the unit 47 from the sensor 46. After comparing the indicated values, the output of the unit 47 is generated a correction signal Δ Q _i , reflecting their difference. To reduce energy consumption for fan operation during the period when the ith section of the rarefaction chamber is not blocked by a moving sheet, the switch 90 is in the off position during this period, and the controller 43 ensures that the fan 18 operates at low revs with minimal energy consumption. At the moment of overlapping of this section, the leading edge of the sheet enters the zone of the sensor 34. In this case, the sensor 34 transmits to the control drive 91 a signal to turn on the switch 90, and after said switching on, the signal Δ Q _i is transmitted from the correction unit 47 to the controller 43, which after receiving the specified signal increases the current value of the flow rate Q _i to its optimal value Q _{i (opt)} for this section. After the sheet is torn off from the rarefaction chamber 2 or after it leaves the i-th section 12, the signal from the sensor 34 is stopped and the drive 91 together with the switch 90 are returned to their original position. In this case, the controller 43 loses communication with the control device 87 and reduces to the initial minimum value the volumetric flow rate Q _{i of} air through the fan 18.

When changing the parameters h, l, δ, γ and μ of the sheets, and / or design parameters k _i1 , k _i2 , ... k _{im of} section 12, and / or the speed V of the conveyor 3, new values of the indicated variable are entered into the software device 88 parameters when preparing the proposed device for work.

The execution of the rarefaction chamber of the device with additional longitudinal rows of sections eliminates the possibility of lateral deflection and permanent deformation of the sheets, which maintains the condition of the transported and stacked sheets, and the presence of the bypass valve 52 eliminates the surge mode of the fan 18, which is harmful for the device, which increases the reliability of operation devices. The presence in the device of the automatic control system for rarefaction inside sections 12 of the rarefaction chamber, overlapped by a moving sheet, allows you to optimize the operation of the device by reducing to the optimal level of energy consumption for the operation of the fan 18 and conveyor 3 while maintaining a stable mode of operation of the device, eliminating the fan 18 entering the surge mode, premature separation of the sheet from the vacuum chamber and its damage. The implementation of sections 12 with rotary transverse 13 and elastic longitudinal 14 side walls allows to reduce the required volumetric air flow through the ejector 8 and, accordingly, the energy consumption for its operation due to the high degree of tightness of these sections, achieved by tightly fitting the lower end of each section 12 of the surface of the moving sheet . The presence in the device of the system of reversing the air flow at the outlet of the ejector 8 allows you to accelerate the separation of the sheet from the vacuum chamber and thereby reduce the duration of the working cycle of laying the sheet and increase the productivity of the device without additional energy costs for its operation.

The supply of each section 12 of the rarefaction chamber with an individual ejector 8 in the second embodiment of the proposed device allows the use of fans with low performance (for example, fans built into vacuum cleaners) having low weight and dimensions and low power consumption, not subject to surging, as ejectors in this device due to which there is no need to equip the device with anti-surge valves 52, due to which its design is simplified. Moreover, a low-capacity fan is able to create a vacuum in a small volume of one section 12, larger than the vacuum created by a powerful fan serving all sections 12 of the vacuum chamber 2 simultaneously.

The noted advantages of the proposed device will provide a significant economic effect in the practical use of the invention.

Claims (17)

1. A device for transporting and stacking sheets, containing a mechanism for feeding sheets, a vacuum chamber with a drive conveyor and an ejector, a lifting table for laying sheets, mounted under the vacuum chamber, and an air manifold located above the vacuum chamber and connected to the inlet of the ejector, the rarefaction chamber is made in the form of a series of sections longitudinal with respect to the direction of movement of the sheet, each of which has two longitudinal and two lateral and transverse relative to the specified direction their upper wall with an outlet window communicating the internal cavity of the section with the air manifold, and is equipped with a shut-off valve mounted on its upper wall with the possibility of closing the outlet window of the latter, while the shut-off valve of each section of the rarefaction chamber is equipped with a drive configured to open the shut-off valve at the end of the overlapping section of the rarefaction chamber by a moving sheet and closing the specified valve after tearing the sheet from the rarefaction chamber - when the device is in sheet-laying mode or the output of the moving sheet from under the specified section - when the device is in sheet transport, characterized in that the vacuum chamber is equipped with at least one longitudinally directed row of sections with the formation of rows transverse to the direction of movement of the sheet, while the shut-off valves of the sections of each transverse Rows are equipped with a common drive, made with the possibility of their simultaneous opening and closing. 2. The device according to claim 1, characterized in that it is equipped with a system for automatically controlling the vacuum in the sections of the vacuum chamber, covered by a moving sheet. 3. The device according to claim 2, characterized in that the system of automatic regulation of rarefaction in sections of the rarefaction chamber covered by a moving sheet is made in the form of a volumetric air flow regulator connected to the ejector, ejected from the rarefaction chamber, and a control device containing a pressure sensor connected to the internal cavity of the air manifold, a sensor for the volumetric flow rate of air ejected from the rarefaction chamber, a correction unit and a software device in which the input is connected to a pressure sensor, and in the output is to one of the inputs of the correction unit, the second input of which is connected to the sensor of the volumetric air flow ejected from the rarefaction chamber, and the output to the regulator of the specified flow. 4. The device according to claim 2, characterized in that the ejector is made in the form of a blade fan equipped with an adjustable drive. 5. The device according to claim 4, characterized in that at least one bypass window for bypassing air from the environment into the collector is made in the air manifold, and the automatic rarefaction control system in the rarefaction chamber sections covered by the moving sheet is made in the form at least one adjustable bypass valve mounted on the air manifold with the possibility of changing the area of the passage section of the bypass window of the last and equipped with an adjustable drive with a control device m, containing a pressure sensor connected to the internal cavity of the air manifold, a correction unit and a software device, the input of which is connected to the input device into it of the volumetric air flow rate through the fan, and the output to one of the inputs of the correction unit, the second input of which is connected to the sensor pressure, and the output - to an adjustable bypass valve actuator. 6. The device according to claim 5, characterized in that the input device into the software device the volumetric flow rate of air through the fan is made in the form of a device for manual input of the specified value. 7. The device according to claim 5, characterized in that the input device into the software device the volumetric flow rate of air through the fan is made in the form of a sensor of the specified flow rate. 8. The device according to claim 4, characterized in that at least one bypass window is made in the air manifold for bypassing air from the environment to the collector, and the automatic rarefaction control system in the rarefaction chamber sections covered by the moving sheet includes at least one adjustable bypass valve mounted on the air manifold with the possibility of changing the area of the passage section of the bypass window of the latter and equipped with an adjustable drive, the air volumetric flow regulator Without a fan connected to the drive of the latter, and a control device containing a pressure sensor connected to the internal cavity of the air manifold, a volumetric air flow sensor through the fan, a rarefaction correction unit, a volumetric air flow correction unit through the fan and a software device with one input connected to the pressure sensor, the second input to the sensor of the volumetric air flow through the fan, one output to the input of the rarefaction correction unit and the second output to the input of the volumetric correction unit the air flow through the fan, while the rarefaction correction unit has a second input connected to the pressure sensor and an output connected to an adjustable bypass valve actuator, and the volume air flow correction unit through the fan has a second input connected to the specified flow sensor, and an output, connected to the regulator of the latter. 9. The device according to any one of claims 1 to 8, characterized in that it is equipped with an air duct with an outlet pipe located in front of the first transverse row of sections of the vacuum chamber along the sheet, and each section in the indicated row is made with an inlet window for air passage, communicating its internal cavity with an air duct in which a two-position valve is placed, made with the possibility of overlapping the inlet windows of the sections of the specified row in the initial closed position and the possibility of moving into the open position with the opening connected inlet windows and at the same time blocking the air passage from the air pipe to the outlet of its exhaust pipe and ensuring the air passage from the air pipe into sections of the indicated row through their inlet windows, while the ejector communicates with the air outlet and is installed near the specified series of sections of the rarefaction chamber, and a two-position valve equipped with a drive configured to open the valve before tearing off the sheet from the vacuum chamber and closing the valve after said tearing. 10. The device according to any one of claims 1 to 8, characterized in that it is equipped with an exhaust pipe connected to the outlet of the ejector, which is installed close to the outlet of the air manifold, and the latter is made with an inlet window for air passage, communicating the internal cavity of the air manifold with an outlet pipe, in which a two-position valve is placed, configured to block the inlet window of the air manifold in the initial closed position and the possibility of translating into the open position with the opening of the specified inlet about the window and at the same time blocking the air passage from the outlet of the ejector to the outlet of the exhaust pipe and ensuring the passage of air from the exit of the ejector to the air manifold through its inlet window, while the on-off valve is equipped with a drive configured to open it before the sheet is removed from the vacuum chamber and closed after specified separation. 11. The device according to any one of claims 1 to 10, characterized in that in each section of the rarefaction chamber, the transverse side walls are configured to interact with a moving sheet by rotating these walls relative to the upper wall of the section in the direction of movement of the sheet, and the longitudinal side walls are made with the possibility of interacting with a moving sheet with a fitting to their lower ends of the surface of the specified sheet, while the transverse side walls of the section are spring-loaded relative to its upper wall with the possibility of their return together with the longitudinal side walls of the section to its original position after the sheet is torn off from the rarefaction chamber or after it leaves the latter. 12. The device according to any one of claims 1 to 11, characterized in that the lower end part of the rarefaction chamber interacting with the moving sheet is made of a material having a small coefficient of friction, for example, fluoroplastic. 13. A device for transporting and stacking sheets, containing a mechanism for feeding sheets, a vacuum chamber with a drive conveyor and a lifting table for stacking sheets mounted under the vacuum chamber, while the rarefaction chamber is made in the form of a series of sections longitudinal with respect to the sheet direction of movement, each of which connected to the ejector and has two longitudinal and two lateral walls transverse relative to the indicated direction and the upper wall covering them, characterized in that the rarefaction chamber is provided with at least at least one longitudinally directed series of sections with the formation of rows transverse relative to the direction of movement of the sheet, each section of the rarefaction chamber equipped with an ejector connected to the outer outlet of the upper wall of the rarefaction chamber, each two adjacent sections in each longitudinal row equipped with a shut-off valve installed between these sections and configured to separate the sections from each other in its original closed position and the possibility of their communication in its open position, and in stomach two adjacent transverse rows of vacuum chamber sections shutoff valves adjacent sections provided with a drive adapted to their simultaneous opening at the end of said overlapping adjacent rows of sections of the vacuum chamber a moving sheet and closure sheet after separation from the vacuum chamber when the device is in sheet stacking mode. 14. The device according to item 13, wherein each section of the rarefaction chamber is equipped with a system for automatically regulating the rarefaction acting in the section after it is blocked by a moving sheet, including a volume flow regulator ejected from the air section, connected to the ejector and equipped with a control device containing a sensor pressure connected to the internal cavity of the section, a sensor for the volumetric flow rate of air ejected from the section, a correction unit and a software device in which the input is connected to the sensor yes phenomena, and the output - to one of the inputs of the correction unit, the second input of which is connected to the sensor of the volumetric flow rate of air ejected from the section, and the output to the regulator of the specified flow rate. 15. The device according to item 13 or 14, characterized in that in each section of its rarefaction chamber the exhaust pipe is adjacent to the upper wall, in which there is an inlet window communicating the internal cavity of the section with the exhaust pipe, and the ejector is located in front of the specified inlet window along the way the movement of the air flow in the exhaust pipe, inside of which there is a two-position valve, made with the possibility of blocking the inlet window of the upper wall of the section at the initial closed position and the possibility of moving to the open position with by covering said inlet window and simultaneously blocking the air passage from the ejector outlet to the outlet nozzle outlet and ensuring the air passage from the ejector outlet to the rarefaction chamber section through the inlet window of its upper wall, while the on-off valves located in the outlet pipes of the rarefaction chamber sections are provided with an actuator, made with the possibility of their simultaneous opening before separation of the sheet from the vacuum chamber and closing after the specified separation. 16. The device according to any one of paragraphs.13-15, characterized in that in each section of the rarefaction chamber, the transverse side walls are configured to interact with a moving sheet with the rotation of these walls relative to the upper wall of the section in the direction of movement of the sheet, and the longitudinal side walls are made with the possibility of interacting with the moving sheet with the lower ends of the surface of the sheet being fitted with it, while the transverse side walls of the section are spring-loaded relative to its upper wall with the possibility of returning them together by the longitudinal side walls of the section in the initial position after the sheet is torn from the vacuum chamber or after it leaves the last and in each transverse side wall of the section separating two adjacent sections in each longitudinal row of the vacuum chamber sections, a bypass window is made, and a shut-off valve every two adjacent sections in each specified row of sections of the rarefaction chamber is configured to overlap the specified bypass window in the initial closed position and the possibility of its opening when the valve is open position. 17. The device according to any one of paragraphs.13-16, characterized in that the lower end part of the rarefaction chamber interacting with the moving sheet is made of a material having a small coefficient of friction, for example, fluoroplastic.

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