Sheet feeding device

Abstract

The present invention provides a sheet feeding device, wherein the sheet feeding device comprises: a conveying section, which conveys the topmost sheet among a plurality of sheets floating from a sheet bundle; a blowing section, which blows air obliquely upward from a position lower than the conveying section toward the side of the sheet bundle; and a direction changing section, which changes the direction of the air blown out by the blowing section downward compared with the direction of the air at the position where the air is blown out from the blowing section, and conveys the air between the topmost sheet and the second sheet from the top among the plurality of sheets floating from the sheet bundle.

Description

Technical Field

[0001] The present invention relates to a sheet material feeding device for feeding sheets. Background Art

[0002] As a sheet feeding device for feeding sheets, a paper feeding device is known that blows air to a paper bundle loaded on a paper feeding table to float the paper, uses a suction conveying component to suck and convey the topmost paper among the floated paper, and feeds the paper to a printing device.

[0003] In such a paper feeding device, in order to feed the paper sheets one by one, it is necessary to separate the topmost paper sheet sucked and fed by the suction feeding member from the second paper sheet from the top.

[0004] Japanese Patent Application Laid-Open No. 2008-222400 describes that air is blown obliquely upward from the downstream side of a sheet bundle in the conveying direction of the sheets by suction conveying means toward the sheet bundle side (upstream side) to sort the sheets, thereby separating the top sheet from the second sheet from the top. Summary of the invention

[0005] Problem that the invention aims to solve

[0006] In Japanese Patent Application Laid-Open No. 2008-222400, since the air for separating the sheets is blown obliquely upward, the air generates a buoyancy force on the sheets, and the top sheet may not be sufficiently separated from the second sheet or less from the top. As a result, sheet feeding defects such as overlapping feeding may occur.

[0007] If the air outlet is arranged so as to blow out air horizontally for separating the paper, the generation of the buoyancy force described above can be suppressed. However, this structure causes the air outlet to interfere with the paper being transported, and is therefore difficult to implement.

[0008] An object of the present invention is to provide a sheet feeding device capable of suppressing sheet feeding defects.

[0009] Solutions for solving problems

[0010] The present invention provides a sheet feeding device, wherein the sheet feeding device comprises: a conveying section, which conveys the topmost sheet among a plurality of sheets floating from a sheet bundle; a blowing section, which blows air obliquely upward from a position lower than the conveying section toward the side of the sheet bundle; and a direction changing section, which changes the direction of the air blown out by the blowing section downward compared with the direction of the air at the position where the air is blown out from the blowing section, and conveys the air between the topmost sheet and the second sheet from the top among the plurality of sheets floating from the sheet bundle.

[0011] With the above-described structure, it is possible to reduce sheet feeding defects. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 It is a schematic structural diagram of a paper feeding device according to an embodiment.

[0013] Figure 2 yes Figure 1 The control block diagram of the paper feeding device is shown.

[0014] Figure 3 yes Figure 1 A partially enlarged top view of the paper feeding device is shown.

[0015] Figure 4 yes Figure 1 An enlarged view of the vicinity of the flotation air outlet of the paper feeding device is shown.

[0016] Figure 5 It is an explanatory diagram of the separated air flow. DETAILED DESCRIPTION

[0017] In the following detailed description, for the purpose of explanation, many specific structures are proposed to provide a comprehensive understanding of the disclosed embodiments. However, it is obvious that one or more embodiments can be implemented without these specific structures. In other embodiments, well-known structures and devices are schematically represented for the purpose of simplifying the illustration.

[0018] Hereinafter, an embodiment of the present invention will be described with reference to the accompanying drawings. It should be noted that the same or similar components and elements in the accompanying drawings are marked with the same or similar reference numerals, and the description of these components and elements is omitted or simplified. In addition, it should be noted that the accompanying drawings are schematic diagrams and therefore may differ from actual conditions.

[0019] Figure 1 It is a schematic configuration diagram of a paper feeding device 1 according to an embodiment of the present invention. Figure 2 yes Figure 1 A control block diagram of the paper feeding device 1 is shown. Figure 3 yes Figure 1 A partially enlarged top view of the paper feeding device 1 is shown. Figure 4 yes Figure 1 FIG. 1 is an enlarged view of the vicinity of the floating air outlet 23 of the paper feeding device 1 shown in FIG. Figure 1 The direction perpendicular to the paper surface is called the front-back direction. Figure 1 The up, down, left, and right directions of the paper are called up, down, left, and right directions. Figure 1 , Figure 3 to Figure 5 In the text, RT, LT, UP, DN, FR, and RR are used to represent right, left, above, below, front, and back respectively.

[0020] like Figure 1 , Figure 2 As shown, the paper feeding device (sheet feeding device) 1 of the present embodiment comprises a paper feeding table 2, a lifting motor 3, a paper feeding guide plate 4, an operating door 5, an end guard plate 6, a floating portion 7, a separation portion (blowing portion) 8, a conveying portion 9, an upper limit sensor 10 and a control portion 11.

[0021] The paper feeding device 1 is a device for feeding paper (sheet material) P to a printing device (not shown). Figure 1 In the figure, the direction from left to right is the conveying direction of the conveying unit 9 conveying the paper P. The conveying direction of the conveying unit 9 conveying the paper P is parallel to the horizontal direction. The upstream and downstream in the following description refer to the upstream and downstream in the conveying direction of the conveying unit 9 conveying the paper P.

[0022] The paper feed table 2 is loaded with paper P for printing. The paper feed table 2 is configured to be able to be raised and lowered.

[0023] The lifting motor 3 lifts the paper feed table 2 up and down.

[0024] The paper feed guide plate 4 is a member that limits the position of the downstream end (right end) of the paper P on the paper feed table 2. The paper feed guide plate 4 is arranged near the downstream side of the paper feed table 2. The upper end of the paper feed guide plate 4 is inclined so as to be higher toward the downstream side. The paper feed guide plate 4 has a vertical guide surface 4a that limits the position of the downstream end of the paper P on the paper feed table 2. In addition, as shown in FIG. Figure 3 , Figure 4 As shown, the paper feed guide plate 4 has a notch portion 4 b formed by cutting away an upper portion of a central portion in the front-rear direction. The notch portion 4 b is used to blow air from the floating portion 7 toward the paper P on the paper feed table 2 .

[0025] The control gate 5 is a member for intercepting the paper P floated by the floatation portion 7 except for the uppermost paper P adsorbed to the conveyance portion 9. The two control gates 5 are provided near the lower downstream end of the conveyance portion 9 and spaced apart from each other in the front-rear direction.

[0026] The end guard 6 is a member that regulates the position of the upstream end (left end) of the paper P on the paper feed table 2 .

[0027] The floating unit 7 blows air toward a paper bundle (sheet bundle) PT composed of a plurality of paper sheets P stacked on the paper feed table 2 to float the plurality of paper sheets P at the upper end of the paper bundle PT. The floating unit 7 is disposed on the downstream side of the paper bundle PT. The floating unit 7 includes a floating fan 21, a shutter 22, and two floating air outlets 23.

[0028] The floating fan 21 is a source for generating a floating airflow for floating the sheets P of the sheet bundle PT on the sheet feeding table 2 .

[0029] The shutter 22 switches on / off the blowing of the upward air flow from the upward air blowing port 23 .

[0030] The floating air outlet 23 is an outlet for the floating airflow generated by driving the floating fan 21. The two floating air outlets 23 are arranged near the lower side of the downstream end of the conveying unit 9, spaced apart from each other in the front-rear direction.

[0031] The separation section 8 blows out air for separating the topmost paper P which is floated by the floating section 7 and held by the conveying section 9 from the second and following paper P from the top, thereby generating a separation airflow F (see Figure 5 The separation unit 8 is disposed on the downstream side of the paper bundle PT. The separation unit 8 includes a separation fan 26 and two separation air outlets (blowout ports) 27.

[0032] The separation fan 26 is a source for generating the separation airflow F.

[0033] The separation air outlet 27 is an outlet for separating the air flow F. The separation air outlet 27 extends obliquely upward ( Figure 5 The two separation air blowing outlets 27 are arranged side by side in the front-to-back direction near the lower part of the downstream end of the conveying section 9. The two separation air blowing outlets 27 are arranged in a positional relationship so that the air blown out from each of them can collide with each other and increase the pressure between the topmost paper P and the second paper P from the top.

[0034] The conveying unit 9 holds and conveys the topmost paper P among the plurality of papers P floated from the paper bundle PT by the floating airflow blown by the floating unit 7 by air suction. The conveying unit 9 includes two belt units 31 , a conveying motor 32 , a chamber 33 , and a suction fan 34 .

[0035] The belt unit 31 holds and conveys the paper P. The two belt units 31 are arranged side by side in the front-rear direction. The belt unit 31 includes a conveying belt 36 , a driving roller 37 , and a driven roller 38 .

[0036] The conveyor belt 36 is an endless belt hung on the driving roller 37 and the driven roller 38. A plurality of belt holes 36a are formed on the conveyor belt 36 over the entire circumference. The conveyor belt 36 holds the paper P on the conveying surface 36b by the suction force generated by the belt holes 36a driven by the suction fan 34. The conveying surface 36b is a horizontal surface that is the lower surface of the lower part of the conveyor belt 36 between the driving roller 37 and the driven roller 38. While holding the paper P on the conveying surface 36b, the conveyor belt 36 is rotated (circularly moved) by the driving of the driving roller 37, thereby conveying the paper P. The conveyor belt 36 is arranged so that the right end (the end on the downstream side) of the conveying surface 36b is located downstream (right side) of the guide surface 4a of the paper feed guide plate 4 in the left-right direction.

[0037] The conveyor belt 36 also functions as a direction changing section that changes the direction of the air (separation airflow F) blown obliquely upward and leftward from the separation section 8 to the horizontal direction and conveys the air between the topmost paper P and the second paper P from the top.

[0038] The driving roller 37 rotates (endlessly moves) the conveyor belt 36 . The driving rollers 37 of the two belt units 31 are connected to each other via a shaft 39 .

[0039] The driven roller 38 supports the conveyor belt 36 together with the driving roller 37. The driven roller 38 rotates following the rotating conveyor belt 36. The driven rollers 38 of the two belt units 31 are connected to each other via a shaft 40.

[0040] The conveyance motor 32 rotates the drive roller 37 by rotating the shaft 39 .

[0041] The chamber 33 is a chamber that forms a negative pressure chamber for generating an adsorption force on the belt hole 36a of the conveyor belt 36. The chamber 33 holds the belt unit 31 inside so that the conveying surface 36b of the conveyor belt 36 is exposed to the outside. A vent hole (not shown) is formed on the bottom plate of the chamber 33 at a portion through which the conveyor belt 36 passes. By sucking air into the chamber 33 through the belt hole 36a of the conveyor belt 36 and the vent hole of the chamber 33, an adsorption force is generated at the belt hole 36a.

[0042] The suction fan 34 exhausts air from the chamber 33. When the suction fan 34 exhausts air from the chamber 33, air is sucked from outside the chamber 33 into the chamber 33 through the belt holes 36a of the conveying surface 36b of the conveyor belt 36 and the vent holes of the chamber 33. The suction fan 34 is arranged on the upper side of the chamber 33.

[0043] The upper limit sensor 10 is used to monitor the downstream (right) end surface of the paper P loaded on the paper feed table 2. The upper limit sensor 10 is arranged at a height position downstream of the paper feed table 2 so as to detect the paper P floating by the floating portion 7. The upper limit sensor 10 is composed of a reflective optical sensor.

[0044] The control unit 11 controls the overall operation of the paper feeding device 1. The control unit 11 includes a CPU, a RAM, a ROM, a hard disk, and the like.

[0045] Next, the operation of the paper feeding device 1 will be described.

[0046] When paper feeding starts, the control unit 11 opens the shutter 22. In addition, the control unit 11 starts driving the floating fan 21, the separation fan 26, and the suction fan 34.

[0047] As a result, the flotation airflow is blown out from the flotation air outlet 23, and the separation airflow F is blown out from the separation air outlet 27. In addition, an adsorption force is generated in the belt holes 36a of the conveyor belt 36.

[0048] Under the action of the upward airflow from the upward air blowing port 23, the top plurality of paper sheets P of the paper bundle PT float up from the paper bundle PT, and the top paper sheet P is sucked and held by the conveying surface 36b of the conveying belt 36. Here, the downstream end of the conveying surface 36b is exposed and not covered by the top paper sheet P.

[0049] like Figure 5 As shown in FIG. 1 , the direction of the separated air flow F blown obliquely upward and leftward from the separated air blowing outlet 27 is changed by the downstream end of the conveying surface 36b to be horizontally directed to the upstream side (left side). The separated air flow F after the direction change is sent between the topmost paper P and the second paper P from the top, and flows toward the upstream side.

[0050] The air blown out from the two separation air blowout ports 27 collides with each other while flowing toward the upstream side, thereby increasing the pressure between the topmost paper P and the second paper P from the top.

[0051] In this state, the control unit 11 closes the shutter 22. As a result, the blowing of the floating airflow from the floating air blowing port 23 stops. As a result, the top sheet P and the second sheet or less from the top are separated by the separation airflow F, and the second sheet or less from the top falls.

[0052] Next, the control unit 11 drives the conveyance motor 32 to cause the conveyance unit 9 to convey the paper P.

[0053] Next, in order to supply the next paper P, the control unit 11 opens the shutter 22 and causes the paper P to float upward.

[0054] By repeating the above-mentioned operation, the sheets P are sequentially fed from the sheet feeding device 1 to the printing device.

[0055] In this paper feeding operation, the control unit 11 performs control such that the paper feeding table 2 is raised in accordance with the decrease of the paper P on the paper feeding table 2 caused by the paper feeding. Specifically, each time a sheet of paper is fed, the control unit 11 obtains the sensor value of the upper limit sensor 10 at the time when the paper P is floating upward. Then, when the obtained sensor value is less than a predetermined tracking threshold, the control unit 11 raises the paper feeding table 2 to a height corresponding to the difference between the sensor value and the tracking threshold.

[0056] When the feeding of the number of sheets of paper supplied by the paper feeding operation is completed, the control unit 11 terminates the paper feeding operation.

[0057] As described above, in the paper feeding device 1, the conveyor belt 36 changes the direction of the air (separated airflow F) blown obliquely upward to the left by the separation unit 8 to the horizontal direction, and conveys the air between the topmost paper P and the second paper P from the top. By changing the direction of the separated airflow F in this way, it is possible to suppress the buoyancy generated on the paper P by the separated airflow F. As a result, the separation failure between the topmost paper P and the second or less paper P from the top is reduced, and thus paper feeding failures such as overlapping conveyance can be reduced.

[0058] In addition, in the paper feeding device 1, the conveyor belt 36 also serves as a direction-changing unit for changing the direction of the separated airflow F. Thus, the separated airflow F is changed in direction near the floating paper P, and air can be efficiently conveyed between the topmost paper P and the second paper P from the top. As a result, the separation failure between the topmost paper P and the second or less paper P from the top is further reduced, and paper feeding failures such as overlapping conveyance can be further reduced. In addition, since a dedicated component as a direction-changing unit is not required, the complexity of the device structure can be suppressed.

[0059] In addition, in the paper feeding device 1, the separation section 8 has two separation air blowing outlets 27. Thus, the air blown out from the two separation air blowing outlets 27 collides with each other while flowing to the upstream side, and the pressure between the topmost paper P and the second-to-top paper P can be increased. As a result, the separation failure between the topmost paper P and the second-to-top paper P and below is further reduced, and paper feeding failures such as overlapping feeding can be further reduced.

[0060] In addition, a direction-changing portion that changes the direction of the separated airflow F may be formed by using a component different from the conveyor belt 36. For example, a component that functions as a direction-changing portion may be provided on the downstream side of the conveyor belt 36 so that the separated airflow F blown obliquely upward and leftward by the separation portion 8 collides with the component.

[0061] In addition, in the above-mentioned embodiment, a structure in which two separation air outlets 27 are provided in the separation section 8 is shown, but the number of the separation air outlets 27 is not limited thereto. A structure in which three or more separation air outlets 27 are provided, and the air blown out of each separation air outlet 27 collides with the air blown out of a separation air outlet 27 different from the separation air outlet 27, thereby increasing the pressure between the topmost paper P and the second-top paper P. Since the effect of separating the topmost paper P and the second-top paper P can be obtained by using a smaller number of separation fans than the number of separation air outlets, the driving power of the separation fans can be reduced compared with a structure in which the number of separation air outlets and the number of separation fans are the same.

[0062] In addition, the number of the separation air outlet 27 may be one.

[0063] In addition to the separation unit 8 of the above-mentioned embodiment, two separation mechanisms (blowing units) may be further provided, and the two separation mechanisms are arranged opposite to each other in the front-rear direction across the paper bundle PT on the paper feed table 2, and respectively blow out air for separating the topmost paper P from the second-to-top paper P and below. In addition, these separation mechanisms may blow out air diagonally upward toward the paper bundle PT side, and the direction of the air may be changed to a horizontal direction by a direction changing unit, and the air may be conveyed between the topmost paper P and the second-to-top paper P. In this case, the conveyor belt 36 may also serve as the direction changing unit, or the direction changing unit may be formed by a member different from the conveyor belt 36. In this case, the separation mechanism (blowing unit) may have a plurality of blowing outlets or a single outlet for blowing out air.

[0064] In addition to the floating portion 7 of the above embodiment, two floating mechanisms may be further provided. The two floating mechanisms are arranged opposite to each other in the front-rear direction across the paper bundle PT on the paper feed table 2 and each blows air to the paper bundle PT to float the paper P.

[0065] In addition, in the above-mentioned embodiment, the direction of the air blown obliquely upward to the left by the separation unit 8 is changed to the horizontal direction, but the present invention is not limited thereto, and the direction may be changed downward compared to when the air is blown (the direction of the air at the position where the air is blown out from the separation air blow-out port 27 of the separation unit 8). By changing the direction of the air in this way, the buoyancy generated on the paper P can be reduced. As a result, the separation failure between the top paper P and the second or less paper P from the top is reduced, and thus the failure of paper feeding such as overlapping conveyance can be reduced.

[0066] Furthermore, in the above-mentioned embodiment, the paper feeding device for feeding paper is described, but the present invention is also applicable to a device for feeding sheet materials other than paper.

[0067] The embodiment has the following structure, for example.

[0068] The sheet feeding device of the embodiment comprises: a conveying section that conveys the topmost sheet among a plurality of sheets floating from a sheet bundle; a blowing section that blows air obliquely upward from a position lower than the conveying section toward the sheet bundle side; and a direction changing section that changes the direction of the air blown out by the blowing section downward compared with the direction of the air at the position where the air is blown out from the blowing section, and conveys the air between the topmost sheet among the plurality of sheets floating from the sheet bundle and the second sheet from the top.

[0069] The conveying unit may include a conveying belt that conveys the sheet in a conveying direction, and the conveying belt may also serve as the direction changing unit.

[0070] The blowing unit may include a plurality of blowing outlets each of which blows out air.

[0071] The conveyor belt may include a conveying surface that sucks and holds the uppermost sheet, and the direction-changing portion may include a downstream end portion of the conveying surface in the conveying direction.

[0072] Alternatively, the sheet feeding device may further include: a paper feeding table on which the sheet bundle is loaded; and a paper feeding guide plate having a guide surface for limiting the position of the downstream end of the sheet on the paper feeding table in the conveying direction. Alternatively, the end of the conveying surface on the downstream side in the conveying direction may be located downstream of the guide surface in the conveying direction, and the downstream end of the conveying surface may be exposed from the uppermost sheet before conveying which is sucked and held by the conveying surface.

[0073] The above describes the embodiments of the present invention. However, the present invention can be implemented in other specific forms without departing from its spirit or essential characteristics. Therefore, the present embodiment should be considered in all aspects as illustrative rather than restrictive, and the scope of protection of the present invention is shown by the attached claims rather than by the above description, and therefore, includes all changes that fall within the meaning and scope equivalent to the claims.

[0074] In addition, the effects described in the embodiments of the present invention are merely an enumeration of the best effects achieved by the present invention. Therefore, the effects of the present invention are not limited to the effects described in the embodiments of the present invention.

Claims

1. A sheet material feeding device, wherein: The sheet material feeding device comprises: a floating portion that blows air toward the sheet bundle to float a plurality of sheets of the sheet bundle, a conveying section that conveys an uppermost sheet among a plurality of sheets floating from the sheet bundle in a conveying direction; a blowing section configured to blow air obliquely upward from a position lower than the conveying section toward the sheet bundle side; a direction-changing section that changes the direction of the air blown out by the blowing section to a horizontal direction and delivers the air between the uppermost sheet and the second sheet from the top among the plurality of sheets floating up from the sheet bundle; as well as a control unit that stops the blowing of air by the floating unit while the floating unit blows air toward the sheet bundle to hold the top sheet on the conveying unit and the blowing unit blows air to a position between the top sheet and the second sheet from the top, so that the sheets below the second sheet from the top are separated from the top sheet and fall down; The blow-out port of the blow-out portion is located between the plurality of blow-out ports of the float portion in a direction perpendicular to the conveying direction when the sheet feeding device is viewed in plan.

2. The sheet material feeding device according to claim 1, wherein: The conveying unit has a conveying belt for conveying the sheet along a conveying direction. The conveyor belt also serves as the direction-changing portion.

3. The sheet material feeding device according to claim 1 or 2, wherein: The blowing portion includes a plurality of blowing outlets that respectively blow out air.

4. The sheet material feeding device according to claim 2, wherein: The conveyor belt has a conveying surface for sucking and holding the uppermost sheet. The direction-changing portion includes a downstream end portion of the conveying surface in the conveying direction.

5. The sheet material feeding device according to claim 4, wherein: The sheet material feeding device also comprises: a paper feed table on which the sheet bundle is loaded; and a paper feed guide plate having a guide surface for limiting the position of the downstream end of the sheet on the paper feed table in the conveying direction, An end portion of the conveying surface on the downstream side in the conveying direction is located downstream of the guide surface in the conveying direction. The downstream end portion of the conveying surface is exposed from the uppermost sheet before conveyance that is sucked and held by the conveying surface.

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