CN111003547A

CN111003547A - Negative pressure conveying method and system

Info

Publication number: CN111003547A
Application number: CN201911295324.1A
Authority: CN
Inventors: 汤振华; 王金刚
Original assignee: Guangzhou Kingtau Machinery & Electronics Equipment Co ltd
Current assignee: Guangzhou Kingtau Machinery & Electronics Equipment Co ltd
Priority date: 2019-12-16
Filing date: 2019-12-16
Publication date: 2020-04-14

Abstract

The invention relates to an industrial printing technology, and discloses a negative pressure conveying method, which is used for conveying hard light media from back to front and comprises the following steps: s1, placing a medium on a negative pressure conveying platform, wherein the negative pressure conveying platform is provided with a negative pressure cavity capable of forming a negative pressure adsorption effect on the medium; s2, giving an instantaneous thrust to the medium in the step S1 from two opposite sides to make the medium in the step S1 to be straightened; and S3, conveying the medium subjected to the alignment in the step S2 under negative pressure. The negative pressure conveying system comprises a negative pressure conveying platform used for conveying the medium from back to front and a righting mechanism used for righting the conveyed medium. The medium is prompted to be straightened by the instant thrust and is removed immediately after the action, so that the medium in the conveying process cannot be blocked and cannot be clamped; and the instantaneous thrust is applied from two sides of the medium, so that the medium cannot be damaged as long as the acting area and the acting force are proper.

Description

Negative pressure conveying method and system

Technical Field

The invention relates to the technical field of industrial printing, in particular to a negative pressure transmission method and a negative pressure transmission system.

Background

The industrial printer is widely applied to printing of large-size printing media such as ceramic tiles, wood boards, glass, corrugated paper, buckle plates and the like, ink of various colors or effects is printed on the printing media in an ink-jet mode and is further processed to obtain expected patterns, the ink permeates into the inside of the printing media through corrosion in the printing process, the patterns obtained by spray painting are not easy to fade, and the printing media have the characteristics of water resistance, ultraviolet resistance, scratch resistance and the like.

The industrial printer is often equipped with negative pressure conveying platform to the realization constantly sends the printing medium to the printing district and prints and constantly sends the printing medium who prints away from the printing district, guarantees the automation and smooth and easy of printing. As for printing media such as ceramic tiles, glass and the like, because the printing media have very high hardness, the printing media cannot be damaged by small-degree collision, so that the printing media can be straightened only by installing a channel which is just suitable for the printing media to pass through at one end of the negative pressure conveying platform, and because the negative pressure conveying platform has larger weight, the printing media cannot be displaced after being straightened. However, for light printing media with certain hardness, such as corrugated paper, thin wood boards, etc., because of their light weight, the prior art generally uses a negative pressure adsorption negative pressure conveying platform for conveying, even though the hardness is far inferior to that of tiles, glass, etc., the printing media may be damaged by a small degree of collision, and even machine equipment may be damaged by paper jam, so the conventional alignment method is not feasible for printing media requiring a negative pressure conveying platform for conveying.

Disclosure of Invention

In view of the above, the present invention provides a negative pressure conveying method and system to overcome at least one of the above disadvantages of the prior art.

In order to solve the technical problems, the invention adopts the following technical scheme:

a negative pressure conveying method is used for conveying hard light media from back to front, and comprises the following steps:

s1, placing a medium on a negative pressure conveying platform, wherein the negative pressure conveying platform is provided with a negative pressure cavity capable of forming a negative pressure adsorption effect on the medium;

s2, giving an instantaneous thrust to the medium in the step S1 from two opposite sides to make the medium in the step S1 to be straightened;

and S3, conveying the medium subjected to the alignment in the step S2 under negative pressure.

After the medium is placed on the negative pressure conveying platform, instantaneous thrust is given from two sides to enable the medium to be automatically aligned, and after the medium is aligned, the medium is conveyed forwards according to the aligned direction due to the existence of negative pressure adsorption, so that the medium can be accurately printed. The medium is prompted to be straightened by the instant thrust and is removed immediately after the action, so that the medium in the conveying process cannot be blocked and cannot be clamped; and the instantaneous thrust is applied from two sides of the medium, so that the medium cannot be damaged as long as the acting area and the acting force are proper.

To further improve the degree of automation, in step S1, a medium is stacked on the negative pressure conveying platform, the medium being stacked as a plurality of media stacked in a pile; in step S2, an instantaneous thrust is given to the media stack in step S1 to correct the media stack; in step S3, the first medium from the bottom up in step S2 is conveyed under negative pressure, and a continuous resistance is given to the second and the higher media from the bottom up so that the second and the higher media are not conveyed. After the setting, exert a continuous resistance through the front and hinder it and then the bottommost layer medium by the conveying forward to the medium pile that removes the bottommost layer medium, consequently can realize putting into the mesh of conveying one by one in pile, the medium can become to pile up and put negative pressure conveying platform on pile ground, does not need artifical or manipulator to put negative pressure conveying platform on one by it, improves production efficiency greatly.

By giving a continuous resistance in the front direction, the lowest layer of the piled media can pass through, and the media on the piled media are blocked and cannot pass through, so that the purpose of paper separation is achieved. However, at the moment when the bottommost layer of media is completely pulled away from the piled media under the negative pressure adsorption effect, the second layer of the piled media from bottom to top becomes a new bottommost layer, so that the media can be continuously conveyed, the upper part of the negative pressure conveying platform is also fully paved with the media, and the distance between the adjacent media cannot be adjusted, which is not beneficial to the printing operation. To this end, in step S3, when the first media from bottom to top is delivered partially or completely out of the media stack, an upward supporting force is imparted to the media stack from below the media stack to at least the front away from the negative pressure delivery platform surface. When the bottommost medium is about to be conveyed away, upward supporting force is given to the newly bottommost medium in time to enable at least the front part of the newly bottommost medium to leave the surface of the negative pressure conveying platform to temporarily lose the action force of negative pressure adsorption, so that the newly bottommost medium cannot be conveyed, and when the conveyed medium is far enough, the supporting force is removed again to enable the newly bottommost medium to be adsorbed by the negative pressure again and dragged away by the conveying belt.

Each time the instantaneous thrust acts to straighten the medium to be conveyed, as the bottommost medium to be conveyed first, it is necessary to ensure that the instantaneous thrust can act on both sides of the medium to straighten the medium, but it is difficult to ensure when the medium is too thin, and for this reason, in step S2, after the medium stack is given an upward supporting force from below the medium stack in step S1 so that at least the front part of the medium stack is separated from the surface of the negative pressure conveying platform, the medium stack is given an instantaneous thrust to straighten the medium stack. In this way, it is guaranteed that the media is centered before being transported, regardless of the thickness of the media.

In step S3, the transfer is stopped after the medium is transferred to the work area, the transfer is continued after the work area operation is completed, and the step S1 to S3 or S2 to S3 is repeated to transfer the next medium.

The central line of the working area perpendicular to the conveying direction is taken as a symmetry axis, the negative pressure cavities of the working area are symmetrically distributed and two or two groups of symmetrical negative pressure cavities are associated, and the central line of the working area is taken as a positioning line during conveying. The difficulty of negative pressure cavity planning of the negative pressure conveying platform is reduced by changing the positioning method. Firstly, determining a working area with a negative pressure adsorption positioning effect in the operation process through fixed-point positioning operation; secondly, the distribution of the negative pressure cavities in the working area adopts a mode of symmetrically distributing along the central line of the working area, and the symmetrical negative pressure cavities are associated; finally, because of the fixed-point positioning mode, the medium needs to be positioned at a certain position of the working area during operation, and the conveying positioning of the medium adopts a center-to-center positioning mode, namely the operation center of the medium is aligned with the central line of the working area. Therefore, the medium is conveyed and positioned to the central line of the working area during operation, the negative pressure cavities symmetrically distributed on two sides of the central line of the working area can be effectively covered to the maximum extent, and the negative pressure adsorption effect is exerted to the maximum extent.

In step S3, accurate delivery of the media to the work area is ensured by sensing timing or sensing distance or sensing number of motor revolutions. And when the sensing is used for timing or sensing distance counting or sensing the revolution of the motor, timing or distance counting or motor revolution counting is carried out according to the distance between the sensing position and the central line.

In step S3, the conveyed medium passes through the paper passing area and the strengthening area in sequence before being conveyed to the working area; the paper separating area and the strengthening area are mediated by resistance action points, and the negative pressure value of the strengthening area is greater than the negative pressure values of the paper separating area and the working area. When the medium is partially conveyed into the strengthening area and partially remains in the paper separating area, if the negative pressure adsorption effect is not strong enough, the positive swinging result of the paper separating area can not be ensured, therefore, the strengthening area is arranged in front of the resistance action point, the negative pressure value is increased, and the negative pressure adsorption effect is enough to protect the positive swinging result.

The invention also provides a negative pressure conveying system applying the method, which is used for conveying hard light media and comprises a negative pressure conveying platform for conveying the media from back to front and a righting mechanism for righting the conveyed media, wherein the negative pressure conveying platform comprises a negative pressure cavity and a conveying belt wound on the outer side of the negative pressure cavity, and the conveying belt is provided with an air suction hole communicated with the negative pressure cavity; the straightening mechanism is arranged above the rear part of the negative pressure conveying platform and comprises a guide rail, two symmetrically arranged ejector structures and at least one ejector driving device, wherein at least one ejector structure is connected with the guide rail in a sliding mode and driven by the ejector driving device to slide along the guide rail.

After the medium is placed on the negative pressure conveying platform, instantaneous thrust is given from two sides through the centering mechanism to enable the medium to be automatically centered, and after centering, due to the existence of negative pressure adsorption, the medium is conveyed forwards according to the centered position, so that the medium can be accurately printed. The medium is prompted to be straightened by the instantaneous thrust generated under the driving of the pushing driving device, and the medium is removed immediately after being acted, so that the medium in transmission cannot be blocked, and the medium cannot be clamped; and the instantaneous thrust is applied from two sides of the medium, so that the medium cannot be damaged as long as the acting area and the acting force are proper.

The negative pressure conveying system further comprises a paper blocking mechanism used for separating piled and stacked media one by one, the paper blocking mechanism is arranged above the negative pressure conveying platform and in front of the straightening mechanism, a cross beam crossing the negative pressure conveying platform and perpendicular to the conveying direction is further arranged on the negative pressure conveying platform, the paper blocking mechanism comprises a baffle connected to the cross beam, and the baffle is perpendicular to the conveying direction. The baffle in the place ahead is applyed a continuous resistance to the medium pile that removes the bottom medium and is hindered its and then the bottom medium by the conveying forward, consequently can realize putting into the purpose of conveying one by one in pile, and the medium can become to pile up and put negative pressure conveying platform on the ground of piling up, does not need manual work or manipulator to come it to put negative pressure conveying platform one by one, improves production efficiency greatly.

In order to ensure that the bottommost layer of the piled media can pass through and the media on the piled media are blocked and cannot pass through during paper separation, the relationship between the distance a between the lower end of the baffle and the negative pressure conveying platform and the thickness h of the media satisfies the following conditions: a is belonged to (h,2 h). The thicknesses of different types and batches of media are different, in order to improve the universality of the paper separating system, the baffle is connected to the cross beam in a lifting mode, and the height of the baffle is changed by lifting the through hole, so that the baffle meets the relation. Preferably, the baffle is connected to the cross beam through a screw rod lifting mechanism. More preferably, the cross beam is provided with at least two guide holes, at least two screw rods, at least one connecting rod and a paper dividing driving device which are arranged at intervals, one side of the baffle is provided with at least two guide blocks matched with the guide holes, the guide blocks penetrate through the guide holes from one side of the cross beam to enter the other side of the cross beam and are in threaded connection with the screw rods connected to the other side of the cross beam, two adjacent screw rods transmit synchronous action through the connecting rod, and the paper dividing driving device drives one of the screw rods.

In the position where the negative pressure is not absorbed, the medium with a part of the softer material may be slightly arched, and thus may be blocked by mistake. In order to ensure that the conveyed medium can smoothly pass through, the bottom of the baffle is provided with a plurality of bulges or grooves arranged at intervals, so that the lower part of the baffle forms a structure with alternate concave and convex, the downward convex part is opposite to the position with negative pressure adsorption on the negative pressure conveying platform, and the upward concave part is opposite to the position without negative pressure adsorption. Thus, even if the medium to be conveyed is uneven or slightly arched, a part of the medium can smoothly pass under the baffle.

The bottommost layer of the piled media can pass through and the media on the piled media are blocked and cannot pass through by the blocking effect of the baffles, so that the purpose of paper separation is achieved. However, at the moment when the bottommost layer of media is completely pulled away from the piled media under the negative pressure adsorption effect, the second layer of the piled media from bottom to top becomes a new bottommost layer, so that the media can be continuously conveyed, the upper part of the negative pressure conveying platform is also fully paved with the media, and the distance between the adjacent media cannot be adjusted, which is not beneficial to the printing operation. Therefore, the negative pressure conveying system further comprises a paper pushing mechanism for supporting the medium, the paper pushing mechanism is arranged on the negative pressure conveying platform between the two symmetrical pushing structures and comprises a pushing block connected to the negative pressure conveying platform in a lifting mode and a paper pushing driving device for driving the pushing block to lift, and the pushing block is higher than the upper surface of the negative pressure conveying platform when rising and is not higher than the upper surface of the negative pressure conveying platform when falling. The paper ejection mechanism can support the medium to be the new bottommost layer in time when the bottommost layer medium is about to be conveyed away, so that at least the front part of the medium is away from the surface of the negative pressure conveying platform to temporarily lose the acting force of negative pressure adsorption, and the medium cannot be conveyed.

At the moment that the bottommost layer medium is completely pulled away from the piled medium under the action of negative pressure adsorption, the top block needs to rise in time to support a new bottommost layer medium to avoid the transfer of the new bottommost layer medium due to the negative pressure adsorption; if the top block rises too early, the bottommost media may be jammed and not transported further; if the top block rises too late, the new lowest level media will also be transferred prematurely; therefore, the time point at which the top block is lifted needs to be accurately grasped. In order to solve the problem, the roller partially exposed on the upper surface of the top block is arranged at the front part of the top block. Even if the top block rises earlier, due to the action of the roller, the bottommost medium can be conveyed away and cannot be clamped due to the front adsorption effect of the gravity center; and due to the action of the roller, even if the top block rises later, the roller is arranged at the front part, and the new bottommost medium cannot be conveyed too early due to the friction action of the gravity center of the medium which is adsorbed at the back part and at the back part of the top block, so that the rising time of the top block is effectively prolonged, and the precision requirement for controlling the rising and falling is lowered. Preferably, the front part of the top block is an 1/3 area close to the front end of the top block or an area 0-100 mm away from the front end of the top block.

In order to ensure that the roller is smooth and ensure the feeding assisting effect of the roller on the bottommost layer medium to be conveyed and the feeding resisting effect of the roller on the new bottommost layer medium to be conveyed, the bottom of the top block is provided with a roller groove and a roller cover matched and connected with the roller groove, and the roller is arranged in a cavity formed between the roller groove and the roller cover. The installation of gyro wheel is realized through the cooperation of gyro wheel groove and gyro wheel lid, can improve the degree of cooperation of gyro wheel and kicking block, improves the gyro wheel smooth and easy nature.

The paper pushing driving device is a paper pushing cylinder connected to the side face or the bottom of the pushing block. The invention adopts a cylinder driving mode, the jacking block can be directly connected with the paper jacking cylinder and can also be connected with the negative pressure conveying platform through the paper jacking cylinder, thereby effectively reducing the configuration of a transmission part, saving the installation space and being especially suitable for large and complicated equipment such as the negative pressure conveying platform.

For the negative pressure conveying platform of the conveying belt communicated with the negative pressure cavity, the structure of the paper pushing mechanism preferably adopts a long strip structure extending along the conveying direction or a deep structure extending downwards, so that the connection of the air cylinder to the bottom or the front side and the rear side of the top block is undoubtedly the best choice. Preferably, the ejector block front side or rear side extend forward or backward and are used for connecting the connecting portion of a paper ejection cylinder, and a paper ejection cylinder is connected in the connecting portion that extends from front side or rear side, compares in the bottom of direct connection in the ejector block, and the ejector block has certain elastic deformation space, avoids a paper ejection cylinder to be suppressed bad. More preferably, the connecting part extends from the front lower side or the rear lower side of the top block, a stepped structure is formed between the top block and the connecting part, and the part for supporting the medium is really concentrated on the top block, so that the damage to the top block or the paper ejection cylinder caused by collision is better avoided. Most preferably, the paper ejection cylinder is connected to the connecting portion that extends from the downside, because the existence of deformation space, will be to the paper ejection cylinder of its supporting role of kicking block connect in the connecting portion that extends from the downside, compare the downside after, deformation space exists in the rear of paper ejection cylinder, is favorable to preventing that the kicking block is too late to become the medium of new topmost layer by too early conveying when rising.

The upper surface of the front part of the top block is at least partially inclined forwards and downwards, which helps the bottommost medium to be conveyed away to be conveyed more smoothly.

The sufficiently large support surface can reduce the pressure of the top block on the medium to prevent the surface from deforming, and can provide more friction for the medium to be the new bottommost layer on the one hand, but the cross section of the part of the top block matched with the negative pressure conveying platform is not favorable for ensuring the negative pressure density of the negative pressure conveying platform and the compactness of the equipment if the cross section of the part of the top block matched with the negative pressure conveying platform is increased. To this end, the top block further includes a support portion forming an upper surface of the top block, the support portion having a cross-section larger than a cross-section of a middle portion of the top block.

The negative pressure conveying platform is sequentially divided into an input area, a paper dividing area, a reinforcing area, a conveying area, a working area and an output area from back to front, the straightening mechanism is arranged in the paper dividing area or extends backwards to the input area, the paper blocking mechanism is arranged at the boundary of the paper dividing area and the reinforcing area, and the paper pushing mechanism is arranged in the input area; the negative pressure values of the input area, the paper dividing area, the strengthening area, the conveying area, the working area and the output area are P1, P2, P3, P4, P5 and P6 in sequence, and satisfy the following relations: p3 > P1 ═ P2 ═ P5 ═ P4 ═ P6. When the medium is partially conveyed into the strengthening area and partially remains in the paper separating area, if the negative pressure adsorption effect is not strong enough, the positive swinging result of the paper separating area can not be ensured, therefore, the strengthening area is arranged in front of the paper blocking mechanism, the negative pressure value is increased, and the negative pressure adsorption effect is enough to protect the positive swinging result. The negative pressure value P1 of the input area is 16-18 KPa, the negative pressure value P2 of the paper separating area is 16-18 KPa, the negative pressure value P3 of the strengthening area is 20-22 KPa, the negative pressure value P4 of the conveying area is 11-13 KPa, the negative pressure value P5 of the working area is 16-18 KPa, and the negative pressure value P6 of the output area is 11-13 KPa.

Note that the "paper" in the "paper ejecting mechanism", "paper separating system", and "paper blocking mechanism" generally refers to a hard light medium such as corrugated paper, and not only refers to a cardboard such as corrugated paper, but also includes a non-paper hard light medium such as an extruded sheet.

Compared with the prior art, the invention has the following beneficial effects: the automatic alignment is promoted by giving instantaneous thrust from two sides, and after the alignment, due to the existence of negative pressure adsorption, the medium is conveyed forwards according to the aligned direction, so that the medium can be accurately printed. The medium is prompted to be straightened by the instant thrust and is removed immediately after the action, so that the medium in the conveying process cannot be blocked and cannot be clamped; and the instantaneous thrust is applied from two sides of the medium, so that the medium cannot be damaged as long as the acting area and the acting force are proper. After the setting, exert a continuous resistance through the front and hinder it and then the bottommost layer medium by the conveying forward to the medium pile that removes the bottommost layer medium, consequently can realize putting into the mesh of conveying one by one in pile, the medium can become to pile up and put negative pressure conveying platform on pile ground, does not need artifical or manipulator to put negative pressure conveying platform on one by it, improves production efficiency greatly.

Drawings

FIG. 1 is a schematic diagram of a negative pressure delivery method.

Fig. 2 is a schematic structural view of the negative pressure conveying system.

Fig. 3 is a side view of the negative pressure delivery system.

FIG. 4 is a first schematic structural diagram of the aligning mechanism and the paper blocking mechanism.

FIG. 5 is a second schematic structural view of the aligning mechanism and the paper stop mechanism.

Fig. 6 is a schematic structural view of the paper ejection mechanism.

Fig. 7 is an exploded view of the paper ejection mechanism.

Description of reference numerals: the paper cutting machine comprises a negative pressure conveying platform 100, a negative pressure cavity 110, a conveying belt 120, an input area 101, a paper separating area 102, a reinforcing area 103, a conveying area 104, a working area 105, an output area 106, a pushing structure 210, a baffle plate 310, a guide block 311, a cross beam 320, a guide hole 321, a screw rod 322, a connecting rod 323, a paper blocking driving device 324, a top block 410, a roller 411, a roller groove 412, a roller cover 413, a connecting part 414, a supporting part 415 and a paper pushing cylinder 420.

Detailed Description

The drawings are for illustration purposes only and are not to be construed as limiting the invention; for the purpose of better illustrating the embodiments, certain features of the drawings may be omitted, enlarged or reduced, and do not represent the size of an actual product; it will be understood by those skilled in the art that certain well-known structures in the drawings and descriptions thereof may be omitted; the positional relationships depicted in the drawings are for illustrative purposes only and are not to be construed as limiting the invention. The present invention will be described in further detail with reference to specific examples.

Example 1

As shown in fig. 1, a negative pressure conveying method for conveying hard light medium from back to front includes the following steps:

Example 2

As shown in fig. 2 to 3, a negative pressure conveying system applying the above method is used for conveying hard light media, and includes a negative pressure conveying platform 100 for conveying the media from back to front and a straightening mechanism for straightening the conveyed media, where the negative pressure conveying platform 100 includes a negative pressure cavity 110 and a conveying belt 120 wound around the outside of the negative pressure cavity 110, and the conveying belt 120 is provided with an air suction hole communicated with the negative pressure cavity 110; the aligning mechanism is disposed above the rear portion of the negative pressure conveying platform 100, and includes a guide rail, two pushing structures 210 symmetrically disposed, and at least one pushing driving device, wherein at least one pushing structure 210 is slidably connected to the guide rail and is driven by the pushing driving device to slide along the guide rail.

After the medium is placed on the negative pressure conveying platform 100, instantaneous thrust is given from two sides through the centering mechanism to promote the medium to be automatically centered, and after centering, the medium is conveyed forwards according to the centered position due to the existence of the negative pressure adsorption effect, so that the medium can be accurately printed. The medium is prompted to be straightened by the instantaneous thrust generated under the driving of the pushing driving device, and the medium is removed immediately after being acted, so that the medium in transmission cannot be blocked, and the medium cannot be clamped; and the instantaneous thrust is applied from two sides of the medium, so that the medium cannot be damaged as long as the acting area and the acting force are proper.

As shown in fig. 4 to 5, the negative pressure conveying system further includes a paper blocking mechanism for separating stacked media one by one, the paper blocking mechanism is disposed above the negative pressure conveying platform 100 and in front of the straightening mechanism, a cross beam 320 crossing the negative pressure conveying platform 100 and perpendicular to the conveying direction is further disposed on the negative pressure conveying platform 100, the paper blocking mechanism includes a baffle 310 connected to the cross beam 320, and the baffle 310 is perpendicular to the conveying direction. The baffle 310 arranged in the front applies continuous resistance to the medium stack except the bottommost layer of medium to prevent the medium stack from being conveyed forwards along with the bottommost layer of medium, so that the aim of conveying the medium stack one by one can be achieved, the medium can be put on the negative pressure conveying platform 100 in a stack manner, manual work or a mechanical arm is not needed to put the medium stack on the negative pressure conveying platform 100 one by one, and the production efficiency is greatly improved.

In order to ensure that the bottommost layer of the piled media can pass through and the media on the piled media are blocked from passing through during paper separation, the relationship between the distance a between the lower end of the baffle 310 and the negative pressure conveying platform 100 and the thickness h of the media satisfies the following condition: a is belonged to (h,2 h). The thicknesses of different types and batches of media are different, and in order to improve the universality of the paper separating system, the baffle 310 is connected to the cross beam 320 in a lifting manner, and the height of the baffle 310 is changed by lifting the through hole, so that the baffle can meet the relationship. Preferably, the baffle 310 is connected to the cross beam 320 by a screw 322 lifting mechanism. More preferably, the cross beam 320 is provided with at least two guide holes 321, at least two screw rods 322, at least one connecting rod 323 and a paper blocking driving device 324 which are arranged at intervals, one side of the baffle 310 is provided with at least two guide blocks 311 which are matched with the guide holes 321, the guide blocks 311 penetrate through the guide holes 321 from one side of the cross beam 320 to enter the other side of the cross beam 320 and are in threaded connection with the screw rods 322 connected to the other side of the cross beam 320, the two adjacent screw rods 322 are driven by one connecting rod 323 to synchronously act, and the paper blocking driving device 324 drives one of the screw rods 322.

In the position where the negative pressure is not absorbed, the medium with a part of the softer material may be slightly arched, and thus may be blocked by mistake. In order to ensure that the medium to be conveyed can smoothly pass through, the bottom of the baffle 310 is provided with a plurality of protrusions or grooves arranged at intervals, so that the lower part of the baffle 310 forms a concave-convex structure, the downward convex part is opposite to the position with negative pressure adsorption on the negative pressure conveying platform 100, and the upward concave part is opposite to the position without negative pressure adsorption. In this way, even if the medium to be conveyed is uneven or slightly arched, a portion thereof can smoothly pass under the flapper 310.

The paper separating purpose is achieved by the blocking effect of the baffle 310, so that the bottommost layer of the stacked media can pass through and the media on the stacked media are all blocked and cannot pass through. However, at the moment when the bottommost layer of media is completely pulled away from the piled media under the negative pressure adsorption effect, the second layer of the piled media from bottom to top becomes a new bottommost layer, so that the media will be continuously conveyed, the upper part of the negative pressure conveying platform 100 will be covered by the media, and the distance between adjacent media cannot be adjusted, which is not beneficial to the printing operation. For this reason, the negative pressure conveying system further includes a paper ejection mechanism for supporting the medium, as shown in fig. 6 to 7, the paper ejection mechanism is disposed on the negative pressure conveying platform 100 between the two symmetrical ejection structures 210, and includes an ejection block 410 connected to the negative pressure conveying platform 100 in a lifting manner and a paper ejection driving device for driving the ejection block 410 to lift, and when the ejection block 410 rises, the ejection block is higher than the upper surface of the negative pressure conveying platform 100, and when the ejection block 410 falls, the ejection block is not higher than the upper surface of the negative pressure conveying platform 100. The paper ejection mechanism can lift the new bottommost medium to be the bottommost medium when the bottommost medium is about to be conveyed away in time, so that at least the front part of the new bottommost medium is away from the surface of the negative pressure conveying platform 100 to temporarily lose the action force of negative pressure adsorption, and therefore the new bottommost medium cannot be conveyed, and when the conveyed medium moves far enough, the ejection block 410 descends in time to remove the supporting force, so that the new bottommost medium is sucked by negative pressure again and dragged away by the conveying belt 120.

At the moment that the bottommost layer medium is completely pulled away from the stacked medium under the action of negative pressure adsorption, the top block 410 needs to rise in time to support a new bottommost layer medium to avoid the transfer caused by the negative pressure adsorption; if the top block 410 rises too early, the bottommost media may become jammed and not be transported further; if the top block 410 rises too late, the new lowest level media will also be transferred prematurely; therefore, the point in time when the top block 410 is lifted needs to be accurately grasped. In order to solve this problem, the present invention provides a roller 411 partially exposed on the upper surface of the top block 410 at the front portion of the top block 410. Even if the top block 410 rises earlier, the bottommost medium is conveyed away due to the front adsorption effect of the gravity center in front and cannot be clamped due to the action of the roller 411; due to the roller 411, even if the top block 410 rises later, because the roller 411 is arranged at the front part, the new bottommost medium cannot be conveyed too early due to the friction effect that the gravity center of the new bottommost medium is adsorbed at the back part and the back part of the top block 410 is adsorbed at the back part, therefore, the rising time of the top block 410 is effectively prolonged, and the precision requirement for controlling the rising and falling is reduced. Preferably, the front part of the top block 410 is an 1/3 area close to the front end of the top block 410 or an area 0-100 mm away from the front end of the top block 410.

In order to ensure that the roller 411 is smooth and thus ensures the feeding assisting effect on the bottommost layer medium to be fed away and the feeding resisting effect on the new bottommost layer medium to be conveyed, the bottom of the top block 410 is provided with a roller groove 412 and a roller cover 413 matched and connected with the roller groove 412, and the roller 411 is arranged in a cavity formed between the roller groove 412 and the roller cover 413. The roller 411 is mounted by matching the roller groove 412 and the roller cover 413, so that the matching degree of the roller 411 and the top block 410 can be improved, and the smoothness of the roller 411 is improved.

The paper ejection driving device is a paper ejection cylinder 420 connected to the side or bottom of the top block 410. According to the invention, an air cylinder driving mode is adopted, the top block 410 can be directly connected to the paper ejection air cylinder 420, and can also be connected to the negative pressure conveying platform 100 through the paper ejection air cylinder 420, so that the configuration of transmission parts is effectively reduced, the installation space is saved, and particularly, the negative pressure conveying platform 100 is a large-scale complex device.

For the negative pressure transfer platform 100 of the transfer belt 120 communicating with the negative pressure chamber 110, the structure of the paper ejection mechanism preferably adopts a strip structure extending along the transfer direction or a deep structure extending downward, and therefore, it is certainly preferable to connect the air cylinder to the bottom or the front and rear sides of the top block 410. Preferably, the front side or the rear side of the top block 410 extends forwards or backwards to form a connecting part 414 for connecting the paper ejection cylinder 420, and the paper ejection cylinder 420 is connected to the connecting part 414 extending from the front side or the rear side, so that compared with the connecting part directly connected to the bottom of the top block 410, the top block 410 has a certain elastic deformation space, and the paper ejection cylinder 420 is prevented from being damaged. More preferably, the connecting portion 414 extends from the front lower side or the rear lower side of the top block 410, a stepped structure is formed between the top block 410 and the connecting portion 414, and the portion of the supporting function for the medium is really concentrated on the top block 410, so that the damage to the top block 410 or the paper ejection cylinder 420 caused by collision is better avoided. Most preferably, the paper ejection cylinder 420 is connected to the connection portion 414 extending from the front lower side, and the paper ejection cylinder 420 supporting the top block 410 is connected to the connection portion 414 extending from the front lower side due to the presence of the deformation space, which is present behind the paper ejection cylinder 420 compared to the rear lower side, thereby facilitating to prevent the medium, which is to become the new topmost layer, from being prematurely conveyed when the top block 410 rises overnight.

The upper surface of the front portion of the top block 410 is at least partially inclined forward and downward to facilitate the smooth transfer of the bottommost medium to be transferred.

The sufficiently large support surface can reduce the pressure of the top block 410 on the medium and prevent the surface from deforming, and can provide more friction for the medium to be the new bottommost layer, but the cross section of the portion of the top block 410 engaged with the negative pressure conveying platform 100 is increased, which is not favorable for ensuring the negative pressure density of the negative pressure conveying platform 100 and the compactness of the device. To this end, the top block 410 further includes a support portion 415 forming an upper surface of the top block 410, the support portion 415 having a cross-section larger than that of a middle portion of the top block 410.

The negative pressure conveying platform 100 is sequentially divided into an input area 101, a paper dividing area 102, a reinforcing area 103, a conveying area 104, a working area 105 and an output area 106 from back to front, the straightening mechanism is arranged in the paper dividing area 102 or extends backwards to the input area 101, the paper blocking mechanism is arranged at the boundary between the paper dividing area 102 and the reinforcing area 103, and the paper pushing mechanism is arranged in the input area 101; the negative pressure values of the input area 101, the paper separating area 102, the strengthening area 103, the conveying area 104, the working area 105 and the output area 106 are P1, P2, P3, P4, P5 and P6 in sequence, and satisfy the following relations: p3 > P1 ═ P2 ═ P5 ═ P4 ═ P6. When the medium is partially conveyed into the strengthening area 103 and partially remains in the paper separating area 102, if the negative pressure adsorption is not strong enough, the positive swinging result of the paper separating can not be ensured, therefore, the strengthening area 103 is arranged in front of the paper blocking mechanism, the negative pressure value is increased, and the negative pressure adsorption is enough to protect the positive swinging result. The negative pressure value P1 of the input area 101 is 16-18 KPa, the negative pressure value P2 of the paper separating area 102 is 16-18 KPa, the negative pressure value P3 of the reinforcing area 103 is 20-22 KPa, the negative pressure value P4 of the conveying area 104 is 11-13 KPa, the negative pressure value P5 of the working area 105 is 16-18 KPa, and the negative pressure value P6 of the output area 106 is 11-13 KPa.

It should be understood that the above-described embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the embodiments of the present invention. Other variations and modifications will be apparent to persons skilled in the art in light of the above description. And are neither required nor exhaustive of all embodiments. Any modification, equivalent replacement, and improvement made within the spirit and principle of the present invention should be included in the protection scope of the claims of the present invention.

Claims

1. A negative pressure conveying method is used for conveying hard light media from back to front, and is characterized by comprising the following steps:

2. The negative pressure conveying method according to claim 1, wherein in step S1, a medium is stacked on a negative pressure conveying platform, the medium being stacked as a plurality of media stacked in a pile; in step S2, an instantaneous thrust is given to the media stack in step S1 to correct the media stack; in step S3, the first medium from the bottom up in step S2 is conveyed under negative pressure, and a continuous resistance is given to the second and the higher media from the bottom up so that the second and the higher media are not conveyed.

3. The method of claim 2, wherein in step S3, when the first medium from bottom to top is conveyed to be partially or completely separated from the medium stack, an upward supporting force is given to the medium stack from below the medium stack to separate at least the front portion from the surface of the negative pressure conveying platform.

4. The method of claim 3, wherein in step S2, the media stack is given an instantaneous pushing force to align after an upward supporting force is given to the media stack from below the media stack in step S1 to at least partially separate the front portion from the surface of the negative pressure transfer platform.

5. The negative pressure conveying method according to any one of claims 2 to 4, wherein in step S3, the conveying is stopped after the medium is conveyed to the working area, the conveying is continued after the working area operation is finished, and the step S1 to S3 or S2 to S3 is repeated to convey the next medium; the central line of the working area vertical to the conveying direction is taken as a symmetry axis, so that the negative pressure cavities of the working area are symmetrically distributed and two or two groups of symmetrical negative pressure cavities are associated, and the central line of the working area is taken as a positioning line during conveying.

6. The negative pressure conveying method according to claim 5, wherein in step S3, the conveyed medium passes through a paper passing area and a strengthening area in sequence before being conveyed to the working area; the paper separating area and the strengthening area are mediated by resistance action points, and the negative pressure value of the strengthening area is greater than the negative pressure values of the paper separating area and the working area.

7. A negative pressure conveying system applying the method according to any one of claims 1 to 6, which is used for conveying hard light media and is characterized by comprising a negative pressure conveying platform and a straightening mechanism, wherein the negative pressure conveying platform is used for conveying the media from back to front, the straightening mechanism is used for straightening the conveyed media, the negative pressure conveying platform comprises a negative pressure cavity and a conveying belt wound on the outer side of the negative pressure cavity, and the conveying belt is provided with an air suction hole communicated with the negative pressure cavity; the straightening mechanism is arranged above the rear part of the negative pressure conveying platform and comprises a guide rail, two symmetrically arranged ejector structures and at least one ejector driving device, wherein at least one ejector structure is connected with the guide rail in a sliding mode and driven by the ejector driving device to slide along the guide rail.

8. The negative pressure conveying system according to claim 7, further comprising a paper blocking mechanism for separating the stacked media one by one, the paper blocking mechanism being disposed above the negative pressure conveying platform in front of the straightening mechanism, the negative pressure conveying platform further having a cross beam crossing the negative pressure conveying platform and perpendicular to the conveying direction, the paper blocking mechanism including a flap connected to the cross beam, the flap being perpendicular to the conveying direction.

9. The negative pressure conveying system of claim 8, further comprising a paper ejecting mechanism for supporting the medium, wherein the paper ejecting mechanism is disposed on the negative pressure conveying platform between the two symmetrical ejecting structures, and comprises an ejecting block connected to the negative pressure conveying platform in a lifting manner and a paper ejecting driving device for driving the ejecting block to ascend and descend, and the ejecting block is higher than the upper surface of the negative pressure conveying platform when ascending and is not higher than the upper surface of the negative pressure conveying platform when descending.

10. The negative-pressure conveying system of claim 9, wherein the negative-pressure conveying platform is sequentially divided into an input area, a paper dividing area, a reinforcing area, a conveying area, a working area and an output area from back to front, the aligning mechanism is arranged in the paper dividing area or extends backwards to the input area, the paper blocking mechanism is arranged at a boundary between the paper dividing area and the reinforcing area, and the paper pushing mechanism is arranged in the input area; the negative pressure values of the input area, the paper dividing area, the strengthening area, the conveying area, the working area and the output area are P1, P2, P3, P4, P5 and P6 in sequence, and satisfy the following relations: p3 > P1 ═ P2 ═ P5 ═ P4 ═ P6.