JP2021054656A - Belt transfer device, sheet feeding device, image forming device and image forming system - Google Patents

Abstract

To provide a belt transfer device capable of increasing a suction efficiency of a duct as compared with the conventional art.SOLUTION: In a belt transport device provided with an endless belt provided with a through hole and a duct 43 provided with suction ports 81 and 82 arranged in a space surrounded by the inner peripheral surface of the endless belt, a first rectifying unit 85a is provided inside the duct 43 and extends in the width direction orthogonal to the transport direction by the belt. A second rectifying unit that rectifies an airflow from a suction port side toward one end side in the width direction may be provided in at least one of the internal spaces separated from each other by the first rectifying unit 85a.SELECTED DRAWING: Figure 12

Description

The present invention relates to a belt transfer device, a sheet feeding device, an image forming device, and an image forming system.

Conventionally, a belt transport device including an endless belt having a through hole and a duct arranged in a space surrounded by an inner peripheral surface of the endless belt and having a suction port is known.
For example, Patent Document 1 is a sheet feeding device that blows air onto a bundle of seats loaded on a seat loading platform by an air blowing means to lift the top sheet from the bundle of seats and feed the bundle by the feeding means. As a feeding means, those using this type of belt transport device are disclosed.

When this type of belt transport device is used for sheet transport, it is desired to improve the suction efficiency of the duct in order to satisfactorily transport various sheets having different weights and flexibility, particularly sheets that are heavy or difficult to bend.

In order to solve the above-mentioned problems, the present invention has a belt provided with an endless belt having a through hole and a duct provided in a space surrounded by an inner peripheral surface of the endless belt and having a suction port. The transport device is characterized in that a first rectifying section extending in a width direction orthogonal to the transport direction is provided inside the duct.

According to the present invention, the suction efficiency of the duct can be improved as compared with the conventional case.

The schematic block diagram of the image formation system of an embodiment. Schematic diagram of the main body of the electrophotographic image forming apparatus. The schematic block diagram of the sheet feeding device of this embodiment. The perspective view which shows the schematic structure of the sheet feeding device. Enlarged view of the vicinity of the suction belt unit. Enlarged view of the vicinity of the suction belt unit. A perspective view of the suction belt unit viewed from diagonally below. A perspective view of the suction belt drawn transparently. A perspective view of the lower wall side of the duct. Explanatory drawing of the duct which concerns on a comparative example. Explanatory drawing of the airflow in the duct which concerns on a comparative example. The perspective view in which the inner surface of the lower wall of the duct of an embodiment can be seen. A perspective view of the duct viewed from different angles. The perspective view of the duct of the modification 1. Perspective view of the duct seen from different angles. A perspective view of the duct as viewed from a different angle. Explanatory drawing of the air flow in the duct which concerns on modification 1. FIG. The perspective view of the duct of the modification 2. Perspective view of the duct seen from different angles. Explanatory drawing of the duct which concerns on modification 3. The explanatory view of the position Yo of the end part of the modification 3. Explanatory drawing of yet another deformation.

Hereinafter, an embodiment of a sheet feeding device to which the present invention is applied will be described.
FIG. 1 is a schematic configuration diagram of the image forming system 1 of the present embodiment. The image forming system 1 includes an image forming device 2 as an image forming means for forming an image on a sheet, and a sheet feeding device 3 for feeding the sheet to the image forming device 2. The sheet feeding device 3 is provided on the side surface of the image forming device 2 main body.

Among the electrophotographic and inkjet image forming devices to which the sheet feeding device of the present embodiment can be applied, the overall configuration and operation of the image forming device will be described by taking an electrophotographic image forming device as an example. FIG. 2 is a schematic configuration diagram of an electrophotographic image forming apparatus main body. The image forming apparatus main body 2 includes four process units 4Y, 4C, 4M, and 4Bk. Each process unit 4Y, 4C, 4M, 4Bk has the same configuration except that it accommodates toners of different colors of yellow, cyan, magenta, and black corresponding to the color separation components of the color image.

Each process unit 4Y, 4C, 4M, 4Bk has a photoconductor 5 as an electrostatic latent image carrier, a charging roller 6 as a charging means for charging the surface of the photoconductor 5, and a toner image on the surface of the photoconductor 5. A developing device 7 as a developing means for forming the surface of the photoconductor 5 and a cleaning blade 8 as a cleaning means for cleaning the surface of the photoconductor 5 are provided.

An exposure device 9 as an exposure means is arranged above each process unit 4Y, 4C, 4M, 4Bk. The exposure apparatus 9 is configured to irradiate the photoconductor 5 of each process unit 4Y, 4C, 4M, 4Bk with a laser beam. A transfer device 10 is arranged below each process unit 4Y, 4C, 4M, 4Bk. The transfer device 10 has an intermediate transfer belt 15 composed of endless belts hung on a plurality of rollers 11 to 14. The intermediate transfer belt 15 is configured to be able to orbit in the direction shown by the arrow in the figure by rotating one of the plurality of rollers 11 to 14 as a drive roller.

Four primary transfer rollers 16 as primary transfer means are arranged at positions facing the four photoconductors 5. Each primary transfer roller 16 forms a primary transfer nip at a position where the pressed portion of the intermediate transfer belt 15 and each photoconductor 5 come into contact with each other. A secondary transfer roller 17 as a secondary transfer means is arranged at a position facing one roller 14 on which the intermediate transfer belt 15 is stretched. The secondary transfer roller 17 forms a secondary transfer nip at a position where it comes into contact with the intermediate transfer belt 15.

In the image forming apparatus main body 2, a transport path R for guiding the paper supplied from the sheet feeding device 3 to the output tray 18 provided outside the machine through the secondary transfer nip is arranged. There is. In the transport path R, the resist roller 19 is arranged on the upstream side in the paper transport direction from the position of the secondary transfer roller 17. Further, the fixing device 20 is arranged on the downstream side in the paper transport direction from the position of the secondary transfer roller 17. Further, a pair of paper ejection rollers 21 are arranged on the downstream side of the fixing device 20 in the paper transport direction. The fixing device 20 includes a heating roller 20a having a heating source inside, and a pressurizing roller 20b that pressurizes the heating roller 20a. The heating roller 20a and the pressure roller 20b are in pressure contact with each other, and a fixing nip is formed at the pressure contact portion.

The basic operation of the image forming apparatus is as follows. The photoconductors 5 of the process units 4Y, 4C, 4M, and 4Bk are rotationally driven counterclockwise in the figure, and the surface of each photoconductor 5 is uniformly charged to a predetermined polarity by the charging roller 6. Based on the image information of the document read by the scanning device, the surface of each photoconductor 5 charged from the exposure device 9 is irradiated with laser light, and an electrostatic latent image is formed on the surface of each photoconductor 5. .. The image information exposed to each photoconductor 5 is monochromatic image information obtained by decomposing a desired full-color image into yellow, cyan, magenta, and black color information. By supplying toner to the electrostatic latent image thus formed on the photoconductor 5 by each developing device 7, the electrostatic latent image is visualized as a toner image.

One of the rollers for tensioning the intermediate transfer belt 15 is rotationally driven to rotate the intermediate transfer belt 15 in the direction of the arrow in the figure. Further, by applying a constant voltage or a constant current controlled voltage opposite to the charging polarity of the toner to each primary transfer roller 16, the primary transfer nip between each primary transfer roller 16 and each photoconductor 5. A transfer electric field is formed in. Then, the toner images of each color formed on each photoconductor 5 are sequentially superimposed and transferred onto the intermediate transfer belt 15 by the transfer electric field formed in the primary transfer nip. Thus, the intermediate transfer belt 15 carries a full-color toner image on its surface. Further, on the surface of each photoconductor 5 after transfer, toner that could not be completely transferred to the intermediate transfer belt 15 remains. The toner remaining on the photoconductor 5 is removed by the cleaning blade 8.

Paper is carried out from the sheet feeding device 3 shown in FIG. The carried-out paper is timed by the resist roller 19 and sent to the secondary transfer nip between the secondary transfer roller 17 and the intermediate transfer belt 15. At this time, a transfer voltage having a polarity opposite to the toner charging polarity of the toner image on the intermediate transfer belt 15 is applied to the secondary transfer roller 17, and a transfer electric field is formed in the secondary transfer nip. Then, the toner images on the intermediate transfer belt 15 are collectively transferred onto the paper by the transfer electric field formed in the secondary transfer nip.

The paper on which the toner image is transferred is conveyed to the fixing device 20. In the fixing device 20, the paper is sandwiched between the heating roller 20a and the pressure roller 20b to be heated and pressurized, and the toner image is fixed on the paper. After that, the paper is ejected to the output tray 18 by the pair of output rollers 21.

The above description is an image forming operation when forming a full-color image on paper, but one of four process units 4Y, 4C, 4M, and 4Bk is used to form a monochromatic image, or two. Alternatively, three process units can be used to form a two-color or three-color image.

FIG. 3 is a schematic configuration diagram of the sheet feeding device 3 of the present embodiment. FIG. 4 is a perspective view showing a schematic configuration of the sheet feeding device 3. The sheet feeding device 3 includes a paper feed tray 30 as a sheet loading table (sheet loading unit) capable of loading a plurality of sheets P, and a transporting means, a feeding means, or a belt transporting device for transporting the paper P. The suction belt unit 40 is provided. Paper P includes thick paper, postcards, envelopes, plain paper, thin paper, coated paper (coated paper, art paper, etc.), tracing paper, and the like. As a sheet-shaped recording medium other than paper, an OHP sheet, an OHP film, or the like can also be supplied.

The paper feed tray 30 includes a bottom plate 31, a front fence 36 that positions the front end of the paper bundle loaded on the bottom plate 31 in the transport direction, and a pair of side fences 32 that position both ends of the paper bundle in the width direction (FIG. 4). (See) and an end fence 33 for positioning the rear end of the bundle of paper in the transport direction. At the upper end of the front fence 36, a regulating member 34 for restricting the movement of paper other than the paper at the top position (the second and subsequent sheets from the top position) in the transport direction is provided. The regulating member 34 is arranged so as to project upward from the uppermost position of the paper bundle loaded on the paper feed tray 30. A pressing member 35 projecting from the end fence 33 toward the loaded paper P is provided on the upper portion of the end fence 33.

The suction belt unit 40 is arranged above the paper P loaded on the paper feed tray 30. The suction belt 41 as an endless belt having a through hole is provided. The suction belt is provided with a plurality of suction ports (through holes). A duct 43 having a suction port is arranged in a space surrounded by the inner peripheral surface of the suction belt 41. The paper is sucked onto the lower surface of the suction belt 41 by the air sucked from the suction port of the duct 43 through the suction port of the suction belt 41. The suction belt 41 is stretched by a plurality of rollers 42a and 42b, and one of the rollers is rotationally driven to rotate the suction belt 41 in the direction of the arrow in the figure. A pair of transport rollers 50 for transporting the paper P and a paper detection sensor 60 for detecting the transported paper P are arranged in this order on the downstream side of the suction belt 41 in the paper transport direction.

Above the paper feed tray 30, a top surface position detecting device 70 for detecting the position of the top surface of the paper bundle loaded on the paper feed tray 30 is provided. The top surface position detecting device 70 includes an actuator 71 that is configured to come into contact with the upper surface of the paper bundle and swing, and a swing detection sensor 72 that detects the swing of the actuator 71. Paper is supplied from the paper bundle, and the actuator 71 swings as the height of the paper bundle decreases. The swing detection sensor 72 detects the swing amount of the actuator 71, and the push-up means raises the bottom plate 31 of the paper feed tray 30 based on the detection signal at that time, from the top surface of the paper bundle to the suction belt 41. The height h (distance) of the paper is controlled to be constant.

A front blower 46 as an air blowing means for blowing air onto the paper P loaded on the paper feed tray 30 is provided in front of the paper feed tray 30 in the paper transport direction. The side fence 32 is provided with outlets 47a and 47b of the side blower 47 (see FIG. 4).

FIG. 5 is an enlarged view of the vicinity of the suction belt unit 40. The front blower 46 is for separating the levitation nozzle 46a that ejects the levitation air a1 for levitation of the paper, the paper at the highest position (top sheet), and the second and subsequent sheets below it. It has a separation nozzle 46b for ejecting the separation air a2. Further, a lower suction nozzle 45a for generating a lower suction air a3 that sucks air near the tip of the upper part of the sheet bundle downward is arranged. The downward suction nozzle 45a is connected to the downward suction device.

As shown in FIG. 5, the suction port of the lower wall 80 of the duct 43 includes a suction opening 81 (suction opening) facing the tip of the sheet bundle from above and a sheet transport downstream of the sheet bundle in the feeding direction. There is a transport opening 82 (suction opening) so as to face the path (see FIG. 8).

FIG. 6 is an enlarged view of the vicinity of the suction belt unit 40 with the front fence 36 removed, as viewed from the paper feed tray 30 side. In the example shown in FIG. 6, the suction belt 41 is composed of three belts 41a, 41b, and 41c. The separation nozzle 46b is arranged corresponding to the central portion in the paper width direction and faces the central belt 41b. The levitation nozzles 46a are arranged so as to correspond to both end sides in the paper width direction and face the belts 41a and 41b at both ends. The lower suction nozzles 45a are arranged on both end sides in the paper width direction and face the belts 41a and 41c at both ends. The regulating member 34 (see FIG. 3) is arranged at a position facing the lower suction nozzle 45a.

FIG. 7 is a perspective view of the suction belt unit 40 as viewed from diagonally below. FIG. 8 is a perspective view in which the suction belt 41 is drawn transparently so that the lower wall 80 of the duct 43 can be seen. A plurality of suction openings 81 are formed so as to face the respective belts 41a, 41b, 41c. The transport openings 82 are formed one by one so as to face the belts 41a and 41c on both sides. In both FIGS. 7 and 8, the suction port is omitted for the suction belt 41 portion where the roller is wound.

FIG. 9 is a perspective view of the lower wall 80 side of the duct 43. In the illustrated example, four suction openings 81 are formed so as to face the belts 41a, 41b, and 41c. The positions of the suction opening 81 and the transport opening 82 on the lower wall 80 are the same for the duct according to the embodiment and the duct according to the comparative example described below. The virtual line (two-dot chain line) indicates the paper P on the sheet bundle, and the arrow indicates the transport direction by the suction belt 41.

The suction opening may be one large hole, but ribs are provided to prevent the paper from being deformed due to the suction force during suction or to make the paper uniform with the belt surface during suction. It is provided and divided into a plurality of openings. The transport opening is provided to prevent the paper from hanging from the belt suction surface when the rear end of the paper comes out of the suction opening during paper transport, and to transport the paper while firmly sucking it. ..

FIG. 10 is an explanatory diagram of a duct according to a comparative example. FIG. 5 is a perspective view in which the inner surface of the lower wall 80 of the duct 43 can be seen by rotating 180 degrees around the center line in the longitudinal direction from the state of FIG. The upper wall member fixed to the screw hole 80a with a screw is in a removed state. The four sides around the lower wall 80 are formed with side walls 83a and 83b on the long side and side walls 84F and 84R on the short side. The lower wall 80, the side walls 83a, 83b, 84F, 84R, and the upper wall member form an internal space of a rectangular parallelepiped. An exhaust port portion 43a is formed at a connection portion with the outside on the side wall 84R on the short side, which is on the back side of the seat feeding device 3. The side walls 83a and 83b on the long side have a tapered shape that narrows the width toward both ends of the exhaust port 43a in the vicinity of the exhaust port 43a.

FIG. 11 is an explanatory diagram of the airflow in the duct according to the comparative example, and shows the flow velocities at various locations by computer simulation with arrows. FIG. 11A is a view seen from a direction perpendicular to the lower wall 80, and FIG. 11B is a view seen from a direction perpendicular to the side wall 83b on the long side. In each case, each opening is not covered with paper. FIG. 11C is a view seen from a direction perpendicular to the lower wall 80, when all of the suction openings 81 are closed with paper, and the transport openings 82 are not closed with paper. ..

As shown in FIGS. 11A and 11B, the air flowing from the suction opening 81 and the transport opening 82 flows in the chamber toward the exhaust port portion 43a. The air flowing into the chamber from the suction opening 81 and the transport opening 82 randomly spreads in the space inside the chamber. Normally, we want the air to flow evenly to the exhaust port 43a side, but when the air flows into a place where the air density is low, backflow air (vortex) is generated. For example, in the region A of FIG. 11A and the region B of FIG. 11B, a flow in the direction opposite to that of the exhaust port portion 43a is generated. In this way, the vortex interferes with the suctioned air. As a result, a flow in the direction of blowing out from the suction opening 81 is also generated as in the region C of FIG. 11B.

Further, as shown in FIG. 3, when the uppermost sheet of the sheet bundle is adsorbed, the transport opening 82 remains open, and an air flow as shown in FIG. 11C is generated. The paper is once sucked by the suction opening 81, but air continues to flow in from the transport opening 82. This air creates a vortex in the chamber, and the air flows in the direction of peeling the adsorbed paper from the belt. Therefore, since a minute gap is formed between the paper and the belt suction surface, the paper cannot be completely sucked, and there may be a problem that the paper advances minutely.

Further, as shown in FIG. 11B, the air flow in the chamber becomes faster as it is closer to the exhaust port portion 43a side. The line L in FIG. 11B shows the boundary line of the region where the high-speed airflow is generated as high as the inside of the exhaust port portion 43a. As described above, the air flow as high as the inside of the exhaust port 43a is limited to the vicinity of the exhaust port, and the air flow becomes faster as the suction opening 81 corresponding to the suction belt near the exhaust port 43a. Therefore, the paper is sucked from the side where the air flow for sucking the paper is fast. The facing paper portions are attracted in that order. Due to the difference in the suction order, the paper rotates and causes skew.

Therefore, in the duct of the present embodiment, among the various problems described above, first, in order to eliminate the problem that occurs when the suction opening 81 is closed, the air that has flowed in from the transport opening flows into the suction side. Adopted a configuration to prevent. FIG. 12 is a perspective view in which the inner surface of the lower wall 80 of the duct 43 of the embodiment can be seen. FIG. 13 is a perspective view seen from different angles. The duct 43 is provided with a partition portion 85a as a first rectifying portion extending in the width direction orthogonal to the transport direction by the belt. The partition portion 85a divides the space in the duct into a side provided with a suction opening 81 on the upstream side in the transport direction and a side provided with a transport opening 82 on the downstream side.

Further, in the illustrated example, the side wall 85b on the short side that partitions the side opposite to the exhaust port portion 43a in the space on the upstream side is provided at a position aligned with the edge of the suction opening 81. Similarly, the side wall 85c on the short side that partitions the side opposite to the exhaust port portion 43a in the space on the downstream side is provided at a position aligned with the edge of the transport opening 82. These narrow the space where turbulence can occur.

According to the duct of the present embodiment, the internal space of the duct can be completely separated into the suction opening 81 side and the transport opening 82 side. Therefore, when the suction opening 81 is closed, it is possible to prevent a problem caused by the air flowing in from the transport opening 82 entering the duct space having the suction opening 81 and forming a vortex.

14 to 16 are explanatory views of a duct according to a modified example (hereinafter referred to as a modified example 1). In the duct according to the first modification, in addition to the partition portion 85a, the air flowing into the space on the suction opening 81 side between the areas of the four suction openings 81 corresponding to the suction belts 41a, 41b, and 41c interfere with each other. Partitions 87 and 88 are provided to partition the exhaust port 43a so as not to prevent it. Further, in the space on the transport opening 82 side, a partition 90 for partitioning up to the exhaust port 43a is provided so that the air flowing in from the two transport openings 82 does not interfere with each other. As shown in FIG. 16, the ends 85d, 87c, 88c, 90c of the partition portions 85a, 87, 88, 90 extend to the opening of the exhaust port portion 43a.

14 to 16 show a state in which the side wall portion on the long side is excluded from the side wall portion on the long side except for the portion corresponding to the partition portions 87, 88, 90 added in the modification 1. ing. The portions corresponding to the added partition portions 87, 88, 90, etc. are provided with halftone dots so that the shape can be easily understood. In the illustrated example, the upper wall portion 86 of the duct is integrally formed.

In FIG. 14, the two added partition portions 87 and 88 are the block-shaped portion existing on the rib (the portion other than the opening) between the areas of the suction opening on the inner surface of the lower wall and the exhaust port portion 43a side from the tip thereof. It has a flat plate portion extending to. The corner 87a on the upper surface side of the flat plate portion and the corner 87b on the lower surface side of the flat plate portion of the block-shaped portion of the partition portion 87 are each provided with a curvature. Similarly, the other partition portion 88 also has curvatures at the corners 88a and 88b, respectively. In addition, in FIG. 14, the corner 86a connected to the upper wall portion 86 of the side wall 85b that partitions the end portion on the side opposite to the exhaust port portion 43a is also provided with a curvature.

The portions constituting the corners 86a, 87b, and 88b where the air flowing in from the suction opening 81 collides with the exhaust port portion 43a and can change the direction of the flow correspond to the second rectifying portion that changes the direction of the air flow. .. These have the same shape such as the magnitude of curvature. Further, the corners 87a and 88a on the side where the air whose direction is changed at this corner travels while tracing are also made to have the same shape such as the magnitude of curvature. It can be said that these corners 87a and 88a also form the second rectifying unit.

Further, the areas of the three areas of the suction opening 81 are equal to each other, and the cross-sectional area of the space (the space from the suction port side to the curved portion) is within the range of the straight line portion to the lowest point of the curvature portion of each corner. The cross-sectional shape of the virtual plane parallel to the suction port) is equal to the area of the above area, and is equal to each other even among the three areas. The distance between the inner surface of the lower wall of the duct and the flat plate portion of the lower partition portion 88, the distance between the flat plate portion of the partition portion 88 and the flat plate portion of the higher partition portion 87, and the flat plate portion and the upper portion of the partition portion 87. The three spacings of the wall 86 from the inner surface are equal to each other.

In FIG. 15, the added partition 90 has a block-shaped portion existing on the rib between the two transport openings 82 and a flat plate portion extending from the tip thereof toward the exhaust port portion 43a. The corner 90a on the upper surface side of the flat plate portion and the corner 90b on the lower surface side of the flat plate portion of the block-shaped portion of the partition portion 90 are each provided with a curvature. In addition, in FIG. 15, the corner 86b connected to the upper wall portion 86 of the side wall 85c that divides the end portion on the side opposite to the exhaust port portion 43a is also provided with a curvature. This curvature is equal to the curvature of the corner 90b.

Further, a block portion 89 is formed so as to extend from the edge of the transport opening 82 on the left side in FIG. 15 to the exhaust port portion 43a. The corner 89a corresponding to the corner 90b of the block portion 89 is provided with a curvature equal to that of the corner 90a. The distance between the upper surface of the block portion 89 in the drawing and the lower surface of the flat surface portion of the partition portion 90 is equal to the distance between the upper surface of the block portion and the flat plate portion of the partition portion 90 and the lower surface of the upper wall portion. The portions constituting the corners 86b and 90b where the air flowing in from the transport opening 82 collides with the exhaust port portion 43a and the direction of the flow can be changed corresponds to the second rectifying section for changing the direction of the air flow. The corners 90a and 89a on the side where the air turned around at this corner travels while tracing are also made to have the same shape such as the magnitude of curvature. It can be said that these corners 90a and 89a also form the second rectifying unit.

According to this modification 1, it is possible to prevent the inflowing air from interfering with each area of the suction opening 81 up to the exhaust port portion. Further, it is possible to prevent the inflowing air from interfering between the two transport openings 82 up to the exhaust port. Therefore, it is possible to eliminate the problem caused by the occurrence of turbulent flow due to these interferences, and it is also possible to reduce the problem caused by the fact that the exhaust port portion 43a has a higher speed and the suction takes turns. Further, since the shapes such as curvature are made equal to each other, the loss coefficients are the same, and the air flow flowing into the chamber can be made to have a similar speed. Since the cross sections orthogonal to the airflow traveling direction of the airflow passage such as a predetermined interval are made equal to each other, the velocity of the flow can be made closer.

FIG. 17 is an explanatory diagram of the air flow in the duct according to the first modification, and shows the flow velocities at various places by computer simulation with arrows. FIG. 17A is a view seen from a direction perpendicular to the lower wall 80, and FIG. 17B is a view seen from a direction perpendicular to the side wall 83b on the long side. In each case, each opening is not covered with paper. As is clear from the comparison between FIGS. 17 (a) and 11 (a), the space on the suction opening 81 side and the space on the transport opening 82 side are partitioned by the partition portion 85a, so that both spaces are separated. There is no flow across. Therefore, even if only the suction opening 81 is blocked by the paper when the suction of the paper is completed and air flows in from the transport opening 82, the air flowing in from the transport opening 82 is the space on the suction opening 81 side. Can be prevented from adversely affecting.

Moreover, as shown in FIG. 17B, since the interference of the airflow between the areas of the suction opening 81 is prevented, the same flow velocity is obtained at the suction opening 81 of each area. The leader lines X, Y, and Z are boundaries between the left, middle, and right areas in the figure and the air flow path between the exhaust port 43a and the region where a high-speed airflow is generated as high as the inside of the exhaust port 43a. Shimesu. In this way, a high-speed airflow can be generated up to a position facing each area in the left-right direction in the figure. As a result, it is possible to reduce the problem caused by the order of adsorption.

18 and 19 are explanatory views of a duct according to still another modified example (modified example 2).
FIG. 18 is a diagram corresponding to FIG. 14 for the modified example 1, and FIG. 19 is a diagram corresponding to FIG. 15 for the modified example 1. In the second modification, the flat plate portion of the partition portion in the first modification is shortened or eliminated, and the other points are the same.

In FIG. 18, the partition portions 87 and 88 provided in the space on the suction opening 81 side end where the flat plate portion does not reach the exhaust port portion 43a. Specifically, the second partition 87 from the exhaust port 43a is above the edge of the block-shaped portion of the first partition 88 adjacent to the exhaust port 43a (the edge opposite to the exhaust port 43a). It's over. The flat plate portion of the first partition portion 88 ends with the same length as the second flat plate portion.

In FIG. 19, in the partition portion 90 of the space on the transport opening 82 side, the flat plate portion is eliminated by leaving a shape portion such that a corner can be formed in the block shape portion. Although the performance of this modification 2 is inferior to that of the modification 1, the difference in suction flow velocity between the areas of the suction opening 81 can be reduced.

FIG. 20 is an explanatory view of a duct according to still another modified example (modified example 3).
FIG. 20A is a diagram corresponding to FIG. 14 for the modification 1 and FIG. 18 for the modification 2. In the modified example 3, the flat plate portion of the second partition portion 87 in the modified example 2 is extended. The position of the end portion 87c of the flat plate portion of the partition portion 87 in the duct longitudinal direction coincides with the position Yo of the end portion 88c of the flat plate portion of the first partition portion 88 in the duct longitudinal direction.

The air sucked from the suction port is the partition part, and the air blowing direction is deflected so that it only needs to flow toward the exhaust port part 43a, so the end part 87c and the end part 88c are completely aligned at the position Yo. You don't have to let it. However, the position where the end portion 87c extends in the direction of the exhaust port portion 43a from above the edge of the block-shaped portion of the partition portion 88 (the edge opposite to the exhaust port portion 43a) (that is, the partition portion 87 and the partition portion 87c). It suffices that the portions 88 are at least partially overlapped with each other in the extending direction) and are not extended to the exhaust port portion 43a as in the partition portion 87 of FIG.

As shown in FIG. 20B, the end shape of these plate portions can be formed so that the thickness becomes thinner toward the tip. R may be added to the tip to form an arc. This tip shape can also be adopted in each of the above examples. This shape allows smooth airflow. When forming a flow path plate or the like with Mo (molybdenum metal), a surface layer may be formed. It may be only the surface of the partition plate or the entire wall surface of the flow path. A material such as ABS, POM, or nylon is used for plating or alumite treatment to protect the Mo surface, smooth the surface, and reduce air resistance.

The positions Yo of the ends 87c and 88c in the duct longitudinal direction are defined as follows. FIG. 21 shows the position Yo of the end portion using the explanatory view of the air flow of FIG. This position is a position where the flow velocity becomes constant on the suction opening 81 side. The effective cross section of the air flow path becomes larger than this position because the flat plate portion does not exist on the exhaust port portion 43a side. As a result, the flow is improved.

In each of the above examples, the partition portion 85a between the suction opening side and the transport opening side completely partitions the inner surface of the lower wall and the lower surface of the upper wall of the duct. As shown in FIG. 22, it may be partially partitioned so as to generate a gap G. In other words, it is sufficient to only partition the space.

As described above, according to the present embodiment, the following actions can be achieved.
1. 1. By separating the suction / transport flows, the performance can be improved without the respective air interfering with each other.
2. The flow in the chamber can be made uniform, and a flow without flow velocity loss can be provided.
3. 3. By making the shape of the inflowing duct the same, the loss coefficient of the flow in the duct can be made the same, and the flow can be made uniform.

From the above actions, the following effects can be achieved. That is, the suction power is increased, and it can be applied to thicker paper and heavier paper (which can be transported or fed to paper, for example, sheet transport such as film, plastic, and sheet metal). Further, since the air flowing in from the suction port can be made uniform, it is possible to prevent skewing and provide higher transfer accuracy.
A modeling method using a 3D prelinter can be used for manufacturing each part of the duct. Even if it cannot be integrally molded, it can be manufactured by dividing it and assembling the parts shape.

The above embodiment is an example, and various modifications are possible. For example, it can be applied to a belt having no through hole instead of a belt having a through hole. In this case, the belt is arranged so as to expose the suction port of the duct. Further, for example, the belt transport device is not limited to the sheet feeding device, and can be generally applied to a belt device using a suction belt such as a sheet transport device.

1: Image forming system 2: Image forming device main body 3: Sheet feeding device 4Bk: Process unit 4C: Process unit 4M: Process unit 4Y: Process unit 5: Photoreceptor 6: Charging roller 7: Developing device 8: Cleaning blade 9 : Exposure device 10: Transfer device 11: Roller 14: Roller 15: Intermediate transfer belt 16: Primary transfer roller 17: Secondary transfer roller 18: Paper ejection tray 19: Resist roller 20: Fixing device 20a: Heating roller 20b: Pressurization Roller 21: Paper ejection roller 30: Paper feed tray 31: Bottom plate 32: Side fence 33: End fence 34: Regulatory member 35: Pressing member 36: Front fence 40: Suction belt unit 41: Suction belt 41a: Suction belt 41b: Suction Belt 41c: Suction belt 42a: Roller 42b: Roller 43: Duct 43a: Exhaust port 45a: Downward suction nozzle 46: Front blower 46a: Floating nozzle 46b: Separation nozzle 47: Side blower 47a: Outlet 47b: Outlet 50: Conveyor roller 60: Paper detection sensor 70: Top surface position detection device 71: Actuator 72: Swing detection sensor 80: Lower wall 80a: Screw hole 81: Suction opening 82: Conveyance opening 83a: Side wall 83b: Side wall 84F: Side wall 84R: Side wall 85a: Partition 85b: Side wall 85c: Side wall 85d: End 86: Upper wall 86a: Corner 86b: Corner 87: Partition 87a: Corner 87b: Corner 87c: End 88: Partition 88a : Corner 88b: Corner 88c: End 89: Block 89a: Corner 90: Partition 90a: Corner 90b: Corner 90c: End 100: Image forming apparatus 200: Sheet feeding device A: Area B: Area C: Area G: Gap L: Line P: Paper R: Conveyance path X: Leader line Y: Leader line Z: Leader line a1: Floating air a2: Separation air a3: Downward suction air

JP-A-2019-94212

Claims (12)

In a belt transport device provided with an endless belt and a duct provided in a space surrounded by an inner peripheral surface of the endless belt and provided with a suction port.
A belt transport device characterized in that a first rectifying unit extending in a width direction orthogonal to a transport direction by a belt is provided inside the duct. In the belt transport device according to claim 1,
The belt transport device is characterized in that the first rectifying unit is provided so as to partition the inside of the duct into an upstream side and a downstream side in the transport direction. In the belt transport device according to claim 1 or 2.
At least one of the internal spaces partitioned by the first rectifying unit is provided with a second rectifying unit that rectifies the airflow from the suction port side toward one end side in the width direction. Belt transfer device. In the belt transport device according to claim 3,
A belt transport device characterized in that at least one of the second rectifying portions is provided so as to partition a region on the side of the suction port. In the belt transport device according to claim 4,
A belt transport device characterized in that the shapes of portions having a curvature for rectifying an air flow from the suction port side toward one end side in the width direction are made equal to each other. In the belt transport device according to claim 5,
The cross-sectional shape of the space from the side of the suction port to the portion having the curvature by the virtual plane parallel to the suction port is equal to each other between the regions partitioned by at least one of the second rectifying portions. A belt transfer device characterized by the fact that it has been used. In the belt transport device according to any one of claims 4 to 6.
The belt is divided into a plurality of belts in the width direction, and the belt transport device is characterized in that the regions divided into the divided belts face each other. In the belt transport device according to any one of claims 1 to 7.
A connection portion with the outside is provided at one end of the duct in the width direction.
A belt transport device characterized in that at least one of the first rectifying unit and the second rectifying unit extends to the connecting portion. In a sheet feeding device that blows air onto a bundle of seats loaded on a seat loading platform by an air blowing means to lift the top sheet from the bundle of seats and feed the bundle by the feeding means.
A sheet feeding device according to any one of claims 1 to 8, wherein the belt feeding device is used as the feeding means. In the sheet feeding device of claim 9,
The suction port of the duct is composed of a plurality of suction openings formed on an outer wall, and the suction opening on the upstream side in the feeding direction with the first rectifying portion interposed therebetween is a sheet loaded on the sheet loading table. A sheet feeding device characterized in that the belt transporting device is arranged so as to face the bundle and the suction port on the downstream side in the feeding direction faces the sheet transport path downstream of the sheet bundle in the feeding direction. In an image forming apparatus including an image forming means for forming an image on a sheet, a feeding means for feeding the sheet to the image forming means, and a conveying means for conveying the sheet in the apparatus.
An image forming apparatus according to any one of claims 1 to 8 and the sheet feeding device according to claim 9 or 10 is used as the conveying means or the feeding means. At least in an image forming system including an image forming apparatus provided with an image forming means for forming an image on a sheet and a sheet feeding device for feeding the sheet toward the image forming apparatus.
An image forming system characterized in that the sheet feeding device according to claim 9 or 10 is used as the sheet feeding device.

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