Sheet feeding device and image forming apparatus including the same

Abstract

To provide a sheet feeding device that can improve convenience when opening while reducing the amount of waste and an image forming apparatus including the same.SOLUTION: A sheet feeding device includes a sheet storage part for storing sheets, a sheet loading plate, and a lift mechanism. The sheet storage part has a bottom wall part and a peripheral wall part. The sheet loading plate has a plate-shaped base body part, support pieces, and protruding parts. The protruding parts protrude axially outward from an upper end of each support piece. The peripheral wall part has a pair of support protruding parts and groove parts. The pair of support protruding parts protrude from both inner peripheral surfaces facing the axial direction of a pivot axis and are inserted into through-holes to support the sheet loading plate in a rotatable manner. The groove parts are recessed axially outward from both inner peripheral surfaces facing the axial direction of the pivot axis and extend along the direction of rotation of the protruding parts. The protruding parts are arranged inside the groove parts when the sheet loading plate is raised.SELECTED DRAWING: Figure 9

Description

[Technical field]

[0001] The present invention relates to a sheet feeding device and an image forming apparatus including the same. [Background technology]

[0002] A conventional sheet feeding device is disclosed in Patent Document 1. This sheet feeding device includes a sheet storage section, a sheet stacking plate, and a lift mechanism. The sheet storage section stores sheets. The sheet stacking plate is supported so as to be rotatable in the vertical direction about a rotation shaft disposed at the end on the upstream side in the sheet transport direction. The lift mechanism raises and lowers the sheet stack. The topmost sheet stacked on the sheet stacking plate is fed sequentially. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2017-30877 A Summary of the Invention [Problem to be solved by the invention]

[0004] In the configuration of Patent Document 1, if an impact such as a drop occurs during transportation, the sheet stacking plate may come off from the sheet storage section. In this case, the work of attaching the sheet stacking plate to the sheet storage section when opening the package increases, which reduces convenience. In addition, if the sheet stacking plate is fixed to the sheet storage section with a packaging material such as tape, the work of removing the packaging material when opening the package increases, which reduces convenience. In addition, there is a problem of an increase in the amount of waste.

[0005] In view of the above problems, an object of the present invention is to provide a sheet feeding device that can improve convenience when opening a package while reducing the amount of waste, and an image forming apparatus including the same. [Means for solving the problem]

[0006] In order to achieve the above object, a sheet feeding device of a first configuration of the present invention includes a sheet storage section for storing sheets, a sheet stacking plate, and a lift mechanism. The sheet stacking plate is supported so as to be rotatable in the vertical direction about a rotation shaft arranged at an end on the upstream side in the sheet conveying direction. The lift mechanism raises and lowers the sheet stacking plate. The sheet storage section has a bottom wall portion and a peripheral wall portion. The sheet stacking plate is placed on the bottom wall portion. The peripheral wall portion protrudes upward from the peripheral edge portion of the bottom wall portion to surround the bottom wall portion. The sheet stacking plate has a plate-shaped base portion, a support piece, and a protrusion portion. The base portion is arranged on the bottom wall portion and has a sheet stacked thereon. The support piece protrudes upward from both axial ends of the base portion and has a through hole penetrating in the axial direction. The protrusion portion protrudes axially outward from the upper end portion of each support piece. The peripheral wall portion has a pair of support protrusions and a groove portion. The pair of support protrusions protrude from both inner peripheral surfaces of the pivot shaft that face each other in the axial direction and are inserted into the through holes to rotatably support the sheet stacking plate. The grooves are recessed axially outward from both inner peripheral surfaces of the pivot shaft that face each other in the axial direction and extend along the rotation direction of the protrusions. The protrusions are disposed inside the grooves when the sheet stacking plate is raised. Effect of the Invention

[0007] According to the first aspect of the present invention, it is possible to provide a sheet feeding device that can improve convenience when opening a package while reducing the amount of waste, and an image forming apparatus including the same. [Brief description of the drawings]

[0008] [Figure 1] 1 is a cross-sectional view showing the internal structure of an image forming apparatus 100 according to an embodiment of the present invention. [Diagram 2] FIG. 1 is a perspective view showing a sheet feeding device 1a of an image forming apparatus 100 according to an embodiment of the present invention. [Diagram 3] 1 is a perspective view showing a sheet stacking plate 20 of an image forming apparatus 100 according to an embodiment of the present invention. [Figure 4] 2 is a side cross-sectional view showing the structure around a lift mechanism 30 of an image forming apparatus 100 according to an embodiment of the present invention. FIG. [Diagram 5]2 is an enlarged perspective view showing the periphery of a support piece 22 of a sheet stacking plate 20 of the image forming apparatus 100 according to an embodiment of the present invention. FIG. [Figure 6] 2 is an enlarged perspective view showing the periphery of a support piece 22 of a sheet stacking plate 20 of the image forming apparatus 100 according to an embodiment of the present invention. FIG. [Figure 7] 2 is an enlarged vertical cross-sectional view showing the periphery of a support piece 22 of a sheet stacking plate 20 of an image forming apparatus 100 according to an embodiment of the present invention. FIG. [Figure 8] 2 is an enlarged vertical cross-sectional view showing the periphery of a support piece 22 of a sheet stacking plate 20 of an image forming apparatus 100 according to an embodiment of the present invention. FIG. [Figure 9] 2 is an enlarged perspective view showing the periphery of a support piece 22 of a sheet stacking plate 20 of the image forming apparatus 100 according to an embodiment of the present invention. FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] <Configuration of Image Forming Apparatus 100> Hereinafter, an embodiment of the present invention will be described with reference to the drawings. Fig. 1 is a cross-sectional view showing the internal structure of an image forming apparatus 100 according to an embodiment of the present invention. Note that the solid arrows in the figure indicate the transport path and transport direction of paper.

[0010] Image forming apparatus 100 has a cassette mounting section 101, paper feeding units 117a, 117b, a manual feed tray 102, a paper transport section 103, a document transport device 104, an image reading section 105, an image forming section 106, a transfer section 107, a fixing section 108, a discharge / branching section 109, a double-sided printing unit 110, and a control section 120.

[0011] The cassette mounting section 101 is disposed at the bottom of the image forming apparatus 100. Two sheet feeding devices 1a and 1b are mounted in the cassette mounting section 101. A stack of unprinted paper (sheets) P ​​is loaded and stored inside the sheet feeding devices 1a and 1b.

[0012] The sheet feeding units 117a and 117b separate and feed sheets P one by one from a stack of sheets P. The sheet feeding unit 117a has a pickup roller 129a and a sheet feeding roller pair 130a provided in correspondence with the sheet feeding device 1a. The sheet feeding unit 117b has a pickup roller 129b and a sheet feeding roller pair 130b provided in correspondence with the sheet feeding device 1b.

[0013] The manual feed tray 102 is provided on the exterior of the upper right side of the image forming apparatus 100. Paper of a different size or thickness from the sheets P in the sheet feeding devices 1a and 1b, and items that are fed one by one, such as overhead projector sheets, envelopes, postcards, and shipping labels, are placed on the manual feed tray 102.

[0014] The paper transport unit 103 is located on the downstream side in the sheet transport direction (sheet transport direction) of the cassette mounting unit 101, and is located on the downstream side in the sheet transport direction of the manual feed tray 102, and is located on the left side in the sheet transport direction of the manual feed tray 102. The sheet P sent out from the sheet feeding devices 1a and 1b is transported vertically upward along the side of the main body of the image forming apparatus 100 by the paper transport unit 103, and the sheet P sent out from the manual feed tray 102 is transported horizontally.

[0015] The document transport device 104 is disposed on the upper surface of the image forming apparatus 100, and the image reading unit 105 is disposed below the document transport device 104. When a user copies a document, multiple documents are loaded on the document transport device 104. The document transport device 104 separates and sends out the documents one by one, and the image data thereof is read by the image reading unit 105.

[0016] The image forming unit 106 and the transfer unit 107 are disposed downstream of the paper transport unit 103 in the paper transport direction and below the image reading unit 105. In the image forming unit 106, an electrostatic latent image of the document image is formed based on the image data read by the image reading unit 105, and this electrostatic latent image is developed to form a toner image. Meanwhile, in synchronization with the formation of the toner image in the image forming unit 106, the sheet P is transported from the sheet feeding devices 1a and 1b to the transfer unit 107 via a pair of registration rollers 119 of the paper transport unit 103. The toner image formed in the image forming unit 106 is transferred onto the sheet P in the transfer unit 107.

[0017] The fixing unit 108 is disposed downstream of the transfer unit 107. The sheet P onto which the unfixed toner image has been transferred in the transfer unit 107 is transported to the fixing unit 108, which has a nip portion between a pair of fixing rollers consisting of a heating roller and a pressure roller. The unfixed toner image is fixed to the sheet P by the sheet P passing through the nip portion.

[0018] The discharge / branching section 109 is disposed downstream of the fixing section 108 and in the vicinity of the left side surface of the image forming apparatus 100. When double-sided printing is not performed, the sheet P discharged from the fixing section 108 is discharged from the discharge / branching section 109 to a paper discharge tray 111 provided on the outside of the left side surface of the image forming apparatus 100.

[0019] The duplex printing unit 110 is disposed above the cassette mounting section 101. When performing duplex printing, the sheet P discharged from the fixing section 108 is sent to the duplex printing unit 110 via the discharge / branch section 109. The sheet P sent to the duplex printing unit 110 is inverted by a switchback, and is conveyed again through the paper conveying section 103 to the transfer section 107 with the side on which the image is not formed facing upward.

[0020] The control unit 120 controls the driving of each unit constituting the image forming apparatus 100, such as the cassette mounting unit 101, the paper transport unit 103, the image reading unit 105, the image forming unit 106, the transfer unit 107, and the fixing unit .

[0021] <Configuration of Sheet Feeding Apparatus 1a> Fig. 2 is a perspective view of the sheet feeding device 1a, and Fig. 3 is a perspective view of the sheet stacking plate 20. Fig. 4 is a side cross-sectional view showing the structure around the lift mechanism 30 of the sheet stacking plate 20 of the sheet feeding device 1a. Note that although the configuration of the sheet feeding device 1a will be described here, the sheet feeding device 1b has an entirely similar configuration.

[0022] In the figure, the insertion direction of the sheet feeding device 1a into the cassette mounting portion 101 is indicated by an arrow X1, and the withdrawal direction is indicated by an arrow X2, and the sheet transport direction of the sheet feeding device 1a coincides with the insertion direction X1 of the sheet feeding device 1a. The axial direction (Y1-Y2) of the rotation shaft C coincides with the width direction of the sheet P and the front-rear direction of the image forming apparatus 100. In this embodiment, the sheet transport direction (X1-X2 direction), the axial direction (Y1-Y2 direction), and the up-down direction (Z1-Z2 direction) are perpendicular to each other.

[0023] The sheet feeding device 1a is mounted in the cassette mounting portion 101. A paper feeding unit 117a (see FIG. 1) is disposed above the sheet feeding device 1a, and a sheet P (see FIG. 1) is supplied in the X1 direction. The sheet feeding device 1a includes a sheet storage portion 10, a sheet stacking plate 20, a cursor 7, and a lift mechanism 30.

[0024] The sheet storage section 10 is in the shape of a box with an open top. The sheet storage section 10 stores stacked sheets P inside. The sheet storage section 10 has a bottom wall 11 and a peripheral wall 12. The bottom wall 11 is formed in a rectangular shape when viewed from above.

[0025] The peripheral wall portion 12 is formed in an annular shape and protrudes from the peripheral edge portion of the bottom wall portion 11 to the upper side Z1. A pair of support protrusions 121 are formed on each inner peripheral surface of the peripheral wall portion 12 facing the axial direction (Y1-Y2 direction) of the rotation axis C. The support protrusions 121 are formed protruding from the inner peripheral surface of the peripheral wall portion 12 in the axial direction (Y1-Y2 direction).

[0026] The sheet stacking plate 20 is supported so as to be rotatable in the vertical direction about a rotation axis C located at an end portion on the upstream side X2 in the sheet conveying direction. The sheet stacking plate 20 has a base portion 21 and a support piece 22. The base portion 21 is a plate-shaped member on which sheets P are stacked, and is located on the bottom wall portion 11. A pair of support pieces 22 are located at both ends in the axial direction (Y1-Y2 direction) at the end portion on the upstream side X2 in the sheet conveying direction of the base portion 21.

[0027] The support piece 22 is formed in a plate shape protruding from the upper surface of the base part 21 to the upper side Z1. The support piece 22 is arranged in a direction perpendicular to the axial direction (Y1-Y2 direction) and parallel to the peripheral wall part 12. Each support piece 22 has a through hole 22a penetrating in the axial direction (Y1-Y2 direction). The lower end of the through hole 22a extends across the base part 21. Therefore, the inner end of the through hole 22a in the axial direction (Y1-Y2 direction) is located more inward in the axial direction (Y1-Y2 direction) than the inner end of the support piece 22 in the axial direction (Y1-Y2 direction). The support protrusion 121 is inserted into the through hole 22a. As a result, the end of the sheet stacking plate 20 on the downstream side in the sheet conveying direction (X1 direction) is supported by the support protrusion 121.

[0028] The sheet stacking plate 20 is provided so that a swing end 20b (end on the downstream side X1 in the sheet conveying direction) can move up and down relative to the sheet storage unit 10, with the upper end edge of the through hole 22a in contact with the support protrusion 121 as a fulcrum. The attachment structure of the sheet storage unit 10 and the sheet stacking plate 20 will be described in detail later.

[0029] The cursor 7 is disposed on the upstream side X2 in the sheet transport direction from the sheet stacking plate 20. The cursor 7 is provided on the bottom wall portion 11 so as to be capable of reciprocating in the sheet transport direction (X1-X2 direction). The cursor 7 positions the end of the sheet P loaded on the sheet stacking plate 20 in the sheet transport direction (X1-X2 direction).

[0030] The lift mechanism 30 is disposed below and in the vicinity of the swing end 20b of the sheet stacking plate 20. The lift mechanism 30 has a swing shaft 31 and an operating plate 32. The swing shaft 31 extends in the sheet width direction (Y1-Y2 direction), and both ends of the swing shaft 31 are rotatably held by two bearings (not shown) formed on the bottom wall 11 of the sheet storage section 10. An axial end of the swing shaft 31 is connected to a lift drive section (not shown).

[0031] The operating plate 32 has a base end fixed to the swing shaft 31. The operating plate 32 is disposed, for example, at a position facing approximately the center of the rear surface of the sheet stacking plate 20 in the axial direction (Y1-Y2 direction).

[0032] The swing shaft 31 is rotated by a lift drive unit (not shown), and the operating plate 32 is also rotated. As a result, the sheet stacking plate 20 moves up and down between an elevated position where the sheet P is fed and a lowered position where the sheet P can be set (replenished).

[0033] <Attachment structure between sheet storage section 10 and sheet stacking plate 20>

[0034] 5 and 6 are enlarged perspective views showing the periphery of the support piece 22 of the sheet stacking plate 20, and Fig. 5 shows the state before the sheet stacking plate 20 is attached to the sheet storage section 10. Fig. 6 shows the state after the sheet stacking plate 20 is attached to the sheet storage section 10. Figs. 7 and 8 are enlarged vertical cross-sectional views showing the periphery of the support piece 22 of the sheet stacking plate 20, and Fig. 7 shows the state before the sheet stacking plate 20 is attached to the sheet storage section 10. Fig. 8 shows the state after the sheet stacking plate 20 is attached to the sheet storage section 10.

[0035] The sheet stacking plate 20 has a protrusion 222 and a convex portion 223. The protrusion 222 protrudes from the upper end of the support piece 22 outward in the axial direction (Y1-Y2 direction).

[0036] The protruding portion 223 protrudes outward in the axial direction (Y1-Y2 direction) from the periphery of the lower end of the through hole 221. More specifically, the protruding portion 223 extends downward from the periphery of the lower end of the through hole 221, and its tip portion is bent outward in the axial direction (Y1-Y2 direction). This makes the protruding portion 223 more easily deformable, and absorbs stress acting on the protruding portion 223, thereby preventing the protruding portion 223 from being damaged.

[0037] The support protrusion 121 has a locking portion 121a and a rib 121b. The locking portion 121a is formed in a plate shape extending in the vertical direction from the tip of the support protrusion 121 in the axial direction (Y1-Y2 direction). The locking portion 121a is disposed parallel to the support piece 22. The lower end of the locking portion 121a is located above the upper surface of the bottom wall portion 11, and a gap H is formed between the locking portion 121a and the bottom wall portion 11 (see FIGS. 7 and 8).

[0038] The rib 121b protrudes inward in the axial direction (Y1-Y2 direction) from the lower end of the locking portion 121a and extends in the sheet conveying direction (A1-A2 direction). The upper surface of the rib 121b is inclined downward from the lower end toward the inside in the axial direction (Y1-Y2 direction). This allows the protrusion 223 to slide on the upper surface of the rib 121b and be smoothly guided to the lower side Z2.

[0039] The peripheral wall portion 12 has grooves 122a and 122b. The grooves 122a and 122b are formed by being recessed outward in the axial direction (Y1-Y2 direction) from the inner peripheral surfaces of the peripheral wall portion 12 facing each other in the axial direction (Y1-Y2 direction). The grooves 122b extend from the base of the support protrusion 121 to the upper side Z1, and the upper end is open. The grooves 122a extend in the rotation direction (X1-X2) of the protrusion 222. In this embodiment, the grooves 122a extend in the rotation direction (X1-X2) of the protrusion 222 from the lower end of the grooves 122b. That is, the grooves 122a branch off from the grooves 122b at the base of the support protrusion 121 and extend in the upward direction Z1.

[0040] When attaching the sheet stacking plate 20 to the sheet storage unit 10, the protrusion 222 is placed on the groove 122b, and the sheet stacking plate 20 is pushed downward Z2. This causes the protrusion 222 to be guided along the groove 122a, and the support piece 22 moves smoothly toward the support protrusion 121 (see FIGS. 5 and 7).

[0041] When the sheet stacking plate 20 is further pushed downward Z2, the convex portion 223 slides on the upper surface of the rib 121b. At this time, the locking portion 121a and the convex portion 223 are bent. When the rib 121b is inserted into the gap H, the bent locking portion 121a and the convex portion 223 return to their original shapes. In addition, the upper end of the through hole 221 is supported on the support protrusion 121. As a result, the sheet stacking plate 20 is attached to the sheet storage unit 10, and is supported by the support protrusion 121 so as to be rotatable around the rotation axis C. When the sheet stacking plate 20 is raised and lowered, the convex portion 223 moves through the gap H in the sheet conveying direction (X1-X2 direction).

[0042] When the sheet stacking plate 20 is attached to the sheet storage unit 10, the upper side Z1 of the protrusion 223 is covered by the rib 121b. As a result, when the sheet stacking plate 20 receives a force in the upper side Z1 direction due to an impact during transportation, for example, the protrusion 223 comes into contact with the rib 121b. This makes it possible to prevent the sheet stacking plate 20 from coming off the sheet storage unit 10. Therefore, it is not necessary to fix the sheet stacking plate 20 to the sheet storage unit 10 with a packing material such as tape. This makes it possible to provide a sheet feeding device 1a that can improve convenience when opening while reducing the amount of waste.

[0043] 9 is an enlarged perspective view of the periphery of the support piece 22 of the sheet stacking plate 20, showing the sheet stacking plate 20 attached to the sheet storage unit 10 in a raised state. When the sheet stacking plate 20 is raised, the protrusion 222 rotates about the rotation axis C and moves to the upstream side X2 in the sheet conveying direction and is inserted into the groove 122a. Meanwhile, the convex portion 223 rotates about the rotation axis C and moves to the downstream side X1 in the sheet conveying direction. At this time, the convex portion 223 is shifted downward in the sheet conveying direction X1 with respect to the rib 121b.

[0044] Therefore, when the sheet stacking plate 20 receives a force in the upward Z1 direction in the raised state, the protrusion 223 may come off the rib 121b. In this embodiment, when the sheet stacking plate 20 is raised, the protrusion 222 is disposed inside the groove 122a. Therefore, the sheet stacking plate 20 can be more effectively prevented from coming off the sheet storage unit 10.

[0045] It should be noted that the embodiments disclosed herein are illustrative and not restrictive in all respects. The scope of the present invention is indicated by the claims, not by the description of the embodiments above, and further includes all modifications within the meaning and scope of the claims.

[0046] For example, in the above embodiment, the lift mechanism rotates the actuation plate 32 to raise and lower the sheet stacking plate 20, but it may be configured with other mechanisms. For example, the sheet stacking plate 20 may be raised and lowered by the biasing force of a coil spring. Also, in this embodiment, two sheet feeding devices 1a and 1b are provided, but one or three or more may be provided. [Explanation of symbols]

[0047] 1a, 1b Sheet feeding device 7 Cursor 10 Seat storage area 11 Bottom wall 12 Peripheral wall section 20 Sheet loading plate 20b Swing end 21 Base 22 Support piece 22a Through hole 30 Lift mechanism 31 Swing axis 32 Actuating plate 100 Image forming device 101 Cassette mounting part 102 Manual feed tray 103 Paper transport section 104 Document transport device 105 Image reading unit 106 Image forming section 107 Transcription section 108 Fixing part 109 Branch 110-page printing unit 111 Paper output tray 117a, 117b Paper feed unit 119 Registration Roller Pair 120 Control section 121 Support protrusion 121a Locking part 121b Rib 122a, 122b Groove 129a, 129b Pick-up roller 130a, 130b Paper feed roller pair 221 Through hole 222 Protrusion 223 Convex C Rotation axis H Gap P-sheet

Claims

1. a seat storage section for storing a seat; a sheet stacking plate supported so as to be rotatable in the vertical direction about a rotation shaft disposed at an end portion on the upstream side in the sheet conveying direction; a lift mechanism for lifting and lowering the sheet stacking plate, The sheet storage section includes: a bottom wall portion on which the sheet stacking plate is placed; a peripheral wall portion that protrudes upward from a peripheral edge portion of the bottom wall portion and surrounds the bottom wall portion, The sheet stacking plate is a plate-shaped base portion disposed on the bottom wall portion and on which the sheets are stacked; Support pieces protruding upward from both axial ends of the base portion and having through holes passing through in the axial direction; a protrusion protruding axially outward from an upper end of each of the support pieces, The peripheral wall portion is a pair of support protrusions that protrude from both inner circumferential surfaces that face each other in the axial direction of the pivot shaft and are inserted into the through hole to rotatably support the sheet stacking plate; a groove portion recessed axially outward from both inner circumferential surfaces facing each other in the axial direction of the rotation shaft and extending along the rotation direction of the protrusion portion, The protrusion is disposed inside the groove when the sheet stacking plate is raised.

2. The support protrusion is a locking portion extending in a vertical direction from a tip portion in an axial direction; a rib protruding axially inward from a lower end of the locking portion, the sheet stacking plate has a protrusion protruding axially outward from a lower end periphery of the through hole, The sheet feeding device according to claim 1 , wherein the protrusion is disposed in a vertical gap between the rib and the bottom wall portion.

3. The sheet feeding device according to claim 2 , wherein the rib has an upper surface that slopes downward toward the inside in the axial direction.

4. 4. The sheet feeding device according to claim 2, wherein the protrusion extends downward from a periphery of a lower end of the through hole, and a tip end of the protrusion is bent outward in the axial direction.

5. The sheet feeding device according to claim 1 , wherein the groove is branched at a base of the support protrusion and extends upward.

6. The sheet feeding device according to claim 1 or 2, an image forming unit that forms an image on a sheet; An image forming apparatus comprising:

Images