JP5119183B2 - Paper feeding device and image forming apparatus having the same - Google Patents

Description

  The present invention relates to an image forming apparatus such as a digital copying machine or a laser printer, and more particularly to a paper feeding apparatus.

  2. Description of the Related Art Conventionally, in an image forming apparatus, for example, as a sheet feeding method for sheets stored in a sheet feeding tray, a sheet feeding device having a sheet feeding roller and a separation pad that separate and convey sheets one by one from the sheet feeding tray is used. ing. In such a sheet feeding device, the sheet feeding roller is rotated to convey the sheet, and the sheets are separated one by one by a separation pad pressed against the sheet feeding roller. Then, by utilizing the friction between the sheet feeding roller and the separation pad and the sheet, one of the sheets contacting the sheet feeding roller is separated and conveyed.

  In such a sheet feeding method that separates and conveys a sheet using friction, if the separation pad is worn, the separation performance of the sheet is deteriorated. Therefore, it is necessary to replace the separation pad. However, in order to remove the separation pad, the sheet feeding roller has to be removed, and the replacement work is complicated. Thus, a method for easily exchanging the separation pad has been proposed.

  For example, in Patent Document 1, a mounting portion for mounting the separating means (separating member) to the apparatus main body is exposed by releasing the engagement between the sheet stacking member and the cover member, and the separating means can be attached and detached. Thus, a method is disclosed in which the separation means can be replaced easily and in a short time.

  In Patent Document 2, a call roller for feeding a document bundle and a counterpart member (separating member) are provided so as to be slidable, and the document bundle fed by the call roller is clamped together with the counterpart member. A separation rotating body (paper feed roller) that separates the uppermost document from the document bundle one by one and a guide plate (conveyance guide) that guides the document are attached to a drive shaft (rotation shaft), and the drive shaft is connected to the device. A method has been disclosed for improving the workability of replacement and maintenance work of these parts by making them detachable from the main body.

Further, Patent Document 3 includes a pair of support members that sandwich both end portions in the axial direction of the roller body (separating member), and enables engagement / disengagement between the pair of support members and both end portions in the axial direction. The roller body is removed and engaged with each support member by moving the support member in the direction away from and close to the other support member, and the pair of support members are engaged at both ends. In addition, a method is disclosed in which a roller body can be easily replaced and reliably supported by detachably providing a restricting means for restricting the movement of the support member.

  Further, Patent Document 4 discloses an automatic document feeder that replaces a feeding member by moving a feeding member (separating member) in a thrust direction and inserting and removing a rotating shaft, in the thrust direction of the feeding member. By providing a snap fit that is attached to the rotating shaft of the feeding member and serves as an attachment of the guide member to the apparatus main body and a movement stop of the feeding member in the thrust direction at the end of the guide member adjacent to the guide member. There is disclosed a method for facilitating replacement work of a feeding member by functioning as a stopper for the feeding member and making screwing of the guide member unnecessary.

JP 2007-217065 A Japanese Patent No. 3560742 Japanese Patent No. 3278341 Japanese Patent No. 3457141

  However, in the method of Patent Document 1, although the separation member is exposed by releasing the engagement of the sheet stacking unit with the cover member and rotating the sheet stacking unit toward the apparatus main body, the arrangement of the sheet feeding rollers is not changed. For this reason, it is difficult to access the separation pad due to the presence of the sheet feed roller, and it is necessary to remove the sheet feed roller in order to replace the separation member, and it may take time to replace the separation pad. .

  In the method of Patent Document 2, since the paper feed roller and the conveyance guide are attached to the drive shaft and are integrally attached and detached, it is necessary to remove the paper feed roller in order to replace the separation member. In addition, the methods of Patent Documents 3 and 4 are methods for making the separation member itself detachable and not for accessing the separation member.

  SUMMARY OF THE INVENTION In view of the above problems, the present invention facilitates easy access to a separating member with a simple operation, and can easily perform the replacement operation in a short time. An object of the present invention is to provide an image forming apparatus including the same.

  In order to achieve the above object, the present invention separates and conveys sheets one by one, and forms a nip between a sheet feeding roller for conveying the sheet and the sheet feeding roller. A sheet feeding device having a separating member for separating one sheet at a time, and a conveyance guide that guides a sheet to the downstream side of the sheet feeding roller and is disposed in proximity to the sheet feeding roller. The rotation axis of the paper feed roller has a notch formed by cutting out a part of the outer peripheral surface at a predetermined position with respect to the axial direction of the rotation shaft. The conveyance guide has a substantially C-shaped cross section having a part of an opening that is allowed to pass through the notch of the rotating shaft, and the opening is formed by the cut. Can rotate with the rotating shaft by passing through the notch An engaging portion that can be engaged and disengaged protrudes, and the conveyance guide is rotatable about the rotating shaft and engaged in the axial direction by the engagement of the engaging portion with the rotating shaft. The engaging portion is pivotally supported so as to be movable between a first position adjacent to the paper feed roller without overlapping with the notch portion and a second position overlapping with the notch portion, The sheet is guided to the downstream side at the position 1 and detachable from the rotating shaft at the second position, and the conveyance guide is moved from the first position to the second position to By detaching from the rotating shaft, the sheet feeding roller can be moved on the rotating shaft in a direction away from the separating member.

  According to the present invention, in the paper feeding device having the above-described configuration, a restricting portion capable of restricting rotation of the transport guide when the transport guide is disposed at the first position is provided.

  According to the present invention, in the sheet feeding device having the above-described configuration, the sheet feeding roller is disposed at a central portion in the axial direction of the rotation shaft, and the two conveyance guides are disposed with the sheet feeding roller interposed between the rotation shafts. It is characterized by being.

  According to the present invention, in the sheet feeding device having the above-described configuration, the separation member is a separation pad.

  The present invention also provides an image forming apparatus including the paper feeding device.

  According to the first configuration of the present invention, the notch is formed on the rotation shaft of the paper feed roller, the rotation shaft supports the paper feed roller so as to be movable in the axial direction, and the conveyance guide passes through the notch. An engaging portion that has an opening that is allowed to rotate and engages and disengages in a rotatable manner with the rotary shaft is projected, and the conveyance guide is engaged with the rotary shaft of the engaging portion. The rotary shaft is pivotally supported so as to be movable to the first position and the second position along the axial direction, and the conveyance guide is moved from the first position to the second position to rotate the rotary shaft. The paper feed roller can be moved on the rotating shaft in a direction away from the separating member.

  As a result, the transport guide can be easily detached from the rotating shaft simply by moving in the axial direction. Further, the separation member can be easily accessed without removing the paper feed roller simply by moving the paper feed roller in the axial direction by the removal of the conveyance guide. Therefore, it is possible to easily access the separating member and perform the replacement operation easily and in a short time with a simple operation. Further, after the separation member is exchanged, the conveyance guide can be easily mounted simply by performing the reverse operation.

  According to the second configuration of the present invention, in the paper feeding device of the first configuration, by providing the restricting portion capable of regulating the rotation of the transport guide when the transport guide is arranged at the first position, The sheet can be guided to the downstream side more stably.

  According to the third configuration of the present invention, in the sheet feeding device having the first or second configuration, the sheet feeding roller is disposed in the axial center of the rotation shaft, and the conveyance guide is fed to the rotation shaft. By disposing the two with the roller in between, the sheet can be conveyed more stably. In addition, since the conveyance guides adjacent to both sides of the paper feed roller can be detached from the rotation shaft, access to the separation member can be further facilitated.

  According to the fourth configuration of the present invention, in the sheet feeding device having any one of the first to third configurations, by using the separation member as the separation pad, the separation pad is more easily worn and frequently replaced. Since it is easy to access, it is effective.

  According to the fifth configuration of the present invention, by forming the image forming apparatus including the sheet feeding device having any one of the first to fourth configurations, image formation in which the influence due to the sheet feeding failure is prevented is performed. be able to.

1 is a side cross-sectional view illustrating a configuration of an image forming apparatus including a sheet feeding device according to an embodiment of the present disclosure. The perspective view which shows the structure of the paper feeder concerning this embodiment. FIGS. 3A and 3B are diagrams illustrating a configuration around a shaft and a first conveyance guide used in the sheet feeding device of the present embodiment, in which FIG. 3A is a partial top view, and FIG. ) Is a partial side view as seen from direction A It is a figure which shows the state which the 1st conveyance guide moved to the attachment or detachment position to the axial direction, Comprising: Fig.4 (a) is a top view, FIG.4 (b) was seen from A direction of Fig.4 (a). Side view The perspective view which shows the state which the 1st conveyance guide moved to the attachment or detachment position to the axial direction. FIGS. 6A and 6B are diagrams illustrating a state in which the first conveyance guide is rotated upward, FIG. 6A is a top view, and FIG. 6B is a side view as viewed from the A direction in FIG. FIGS. 7A and 7B are diagrams illustrating a state in which the first conveyance guide is detached from the shaft, FIG. 7A is a top view, and FIG. 7B is a side view as viewed from the A direction in FIG. The perspective view which shows the state which the 1st conveyance guide detached from the shaft. The perspective view which shows the state which the feed roller moved on the shaft in the direction away from the separation pad The perspective view which shows the state which a 2nd conveyance guide moves to an attachment or detachment position to an axial direction. The perspective view which shows the arrangement | positioning state of a separation pad FIG. 11 is an enlarged perspective view showing the periphery of the separation pad of FIG. The perspective view which shows the state which the separation pad fell down 13 is an enlarged perspective view around the separation pad of FIG. The top view which shows the engagement state of the separation pad seen from the upper direction of FIG. Top view showing a state in which the separation pad is disengaged

  Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a side cross-sectional view illustrating a configuration of an image forming apparatus including a paper feeding device according to an embodiment of the present invention.

  In the image forming apparatus 100, an image forming portion P for forming a predetermined image by each process of charging, exposure, development and transfer is disposed. In this image forming portion P, a photosensitive drum 2 carrying a visible image (toner image) is disposed, and the toner image formed on the photosensitive drum 2 is disposed adjacent to the image forming portion. The image is transferred onto the sheet 6 conveyed through the sheet conveyance path, and after being fixed on the sheet 6 in the fixing unit 7, the sheet is discharged from the apparatus main body. While the photosensitive drum 2 is rotated clockwise in FIG. 1, an image forming process for the photosensitive drum 2 is executed.

  Next, the image forming unit P will be described in detail. Around and around the photosensitive drum 2 rotatably disposed, a charger 3 for charging the photosensitive drum 2, an exposure unit 4 for exposing image information to the photosensitive drum 2, and the photosensitive drum 2 Further, a developing unit 5 for forming a toner image and a cleaning unit 9 for removing developer (toner) remaining on the photosensitive drum 2 are provided.

  First, the surface of the photosensitive drum 2 is uniformly charged by the charger 3 and then irradiated by the exposure unit 4 to form an electrostatic latent image corresponding to the image signal on the photosensitive drum 2. A toner container 10 is built in the developing unit 5. The toner in the toner container 10 is supplied onto the photosensitive drum 2 by the developing unit 5 and electrostatically attached thereto, so that a toner image corresponding to the electrostatic latent image formed by exposure from the exposure unit 4 is formed. It is formed.

  The sheet 6 on which the toner image is transferred is accommodated in a paper feed cassette 11a and a stack bypass (manual feed tray) 11b provided thereabove. The sheet 6 accommodated in the sheet feeding cassette 11a passes through the first sheet feeding roller 12 and the registration roller 14, and the sheet 6 accommodated in the stack bypass 11b passes through the sheet feeding device 20 and the registration roller 14 to the image forming unit P. To the position of the photosensitive drum 2. Details of the paper feeding device 20 will be described later.

  The image writing signal is turned ON in accordance with the timing at which the sheet 6 is conveyed from the registration roller 14, and an image is formed on the photosensitive drum 2. The toner image on the photosensitive drum 2 is transferred onto the sheet 6 by applying an electric field to the lower portion of the photosensitive drum 2 with the transfer roller 16 to which a predetermined transfer voltage is applied.

  The sheet 6 on which the toner image has been transferred is detached from the photosensitive drum 2 and conveyed to the fixing unit 7. In addition, the photosensitive drum 2 after the toner image is transferred is removed by the cleaning unit 9 in preparation for the subsequent formation of a new electrostatic latent image. The sheet 6 conveyed from the image forming unit P to the fixing unit 7 is heated and pressed by the fixing roller pair 7a, and the toner image is fixed on the surface of the sheet 6 to form a predetermined image. The sheet 6 on which the image has been formed is then discharged onto a discharge tray 18 by a discharge roller 17.

  FIG. 2 is a perspective view illustrating a configuration of a paper feeding device according to an embodiment of the present invention. FIG. 3A is a configuration around a shaft and a first conveyance guide used in the paper feeding device of the present embodiment. FIG. 3B is a partial side view of FIG. 3A viewed from the A direction. Portions common to FIG. 1 are denoted by the same reference numerals and description thereof is omitted.

  As shown in FIG. 2, the sheet feeding device 20 is separated into a frame 21 by a second sheet feeding roller (sheet feeding roller) 22 for conveying the sheet 6 downstream and a sheet 6 separated one by one. A pad (separating member) 23 is provided. The second paper feed roller 22 forms a nip with the separation pad 23. When the second paper feed roller 22 is driven to rotate, the sheet 6 (see FIG. 1) accommodated in the stack bypass 11b is conveyed, and the second The sheets 6 are separated one by one by a separation pad 23 pressed against the paper feed roller 22.

  As described above, the second paper feed roller 22 and the separation pad 23 separate the sheets 6 one by one and convey them downstream. The second paper feed roller 22 is pivotally supported at the central portion of the shaft (rotating shaft) 24 in the axial direction (A direction in the figure). The shaft 24 is supported on both side walls of the frame 21 so as to be rotatable by the main body of the paper feeding device 20 and supports the second paper feeding roller 22 so as to be movable in the axial direction.

  One end of the shaft 24 in the axial direction is connected to a drive motor (not shown), and the shaft 24 is rotated by the drive of the drive motor. Further, the connection between the shaft 24 and the drive motor is adjusted so that a notch 24a, which will be described later, is positioned in a substantially vertical direction by stopping the drive motor.

  Two notches 24 a are formed at predetermined positions on both outer sides of the second paper feed roller 22 with respect to the axial direction of the shaft 24. As shown in FIGS. 3A and 3B, the notch 24a is formed by notching the outer peripheral surface of the shaft 24 in the vertical direction in a substantially parallel manner. Further, the notch 24 a is formed to have a width smaller than the outer diameter of the shaft 24.

  As shown in FIG. 2, a first conveyance guide (conveyance guide) 25 and a second conveyance guide that guide the sheet 6 to the downstream side close to both outer sides of the second paper feed roller 22 with respect to the axial direction of the shaft 24. A (conveyance guide) 27 is pivotally supported. A first engagement portion (engagement portion) 26 and a second engagement portion (engagement portion) 28 (FIG. 5) are provided at both ends of the first and second transport guides 25 and 27 in the longitudinal direction (direction A in the figure). (See below). In addition, since the structure of the 1st and 2nd conveyance guides 25 and 27 is completely the same, the 1st conveyance guide 25 is demonstrated below.

  As shown in FIGS. 3A and 3B, the first conveying guide 25 has a first opening (opening) 26a on the side opposite to the sheet conveying surface 25a and has a substantially C-shaped cross section. A first engaging portion 26 made of a bearing is projected. The first opening 26a is formed on the upstream side in the sheet conveying direction of the first engagement portion 26 (left side in FIG. 3B), and opens in a direction perpendicular to the notch direction of the notch portion 24a of the shaft 24. ing. The first opening 26 a is formed such that the opening interval is larger than the width of the notch 24 a and smaller than the outer diameter of the shaft 24.

  As a result, the first opening 26a is allowed to pass through the notch 24a in the shaft 24, but not allowed to pass at a position where the notch 24a is not formed. Moreover, the 1st engaging part 26 is arrange | positioned at the 1st conveyance guide 25 by the space | interval which can respectively oppose the two notch parts 24a (refer FIG. 4). Further, when the first engagement portion 26 engages with the shaft 24, the first transport guide 25 is pivotally supported by the shaft 24 so as to be rotatable and movable in the axial direction.

  As shown in FIGS. 2 and 3, at the sheet guide position (first position) where the first conveyance guide 25 can guide the sheet 6, the first engagement portion 26 is notched 24 a with respect to the axial direction. It is arrange | positioned in the position (here A direction upstream from the notch part 24a) which does not overlap. Further, the movement of the first transport guide 25 in the sheet guide position in the axial direction is restricted by a stop ring (not shown). Thus, the first engagement portion 26 is supported by the shaft 24 without being detached from the shaft 24, and can guide the seat 6 to the downstream side.

  On the other hand, the 1st conveyance guide 25 moves to the attachment / detachment position (2nd position) where the 1st engaging part 26 overlaps with the notch part 24a toward the outer side (A direction of a figure) with respect to the axial direction of FIG. Thereby (refer FIG. 4, FIG. 5), the 1st conveyance guide 25 can be rotated and the 1st opening part 26a of the 1st engaging part 26 can be made to correspond with the notch part 24a (refer FIG. 6).

  Thus, the 1st opening part 26a can pass the notch part 24a by pulling up the 1st conveyance guide 25 in the state which made the 1st opening part 26a correspond with the notch part 24a. Thereby, the engagement between the first engaging portion 26 and the shaft 24 can be released, and the first conveyance guide 25 can be detached from the shaft 24 (see FIG. 7).

  Further, as shown in FIGS. 3A and 3B, a first protrusion 25 b bent downward is formed at the upper end of the first conveyance guide 25 on the left end side in the axial direction of the sheet conveyance surface 25 a. A second projecting portion 25c that is bent toward the downstream side in the sheet conveying direction (the right side in FIG. 3B) projects from the lower end portion.

  On the other hand, on the bottom surface of the frame 21, a restricting portion 29 that restricts the rotation of the first conveyance guide 25 when the first conveyance guide 25 moves to the sheet guide position is disposed. The restricting portion 29 is located outside the range in which the sheet is conveyed in the width direction of the conveyance path, and when the first conveyance guide 25 is disposed at the sheet guide position, as shown in FIG. It arrange | positions in the position which overlaps with the 1st and 2nd protrusion parts 25b and 25c with respect to a direction.

  In addition, as shown in FIG. 3B, the restricting portion 29 is disposed at a predetermined interval from the sheet conveyance surface 25 a of the first conveyance guide 25. The upper end surface of the restricting portion 29 is formed so as to come into contact with the first projecting portion 25b from below, and the end surface on the upstream side in the sheet conveying direction (the left side in FIG. 3B) is downstream of the second projecting portion 25c and the sheet conveying direction. It is formed so as to contact from the side.

  Then, the first projecting portion 25b of the first transport guide 25 disposed at the sheet guide position contacts the restricting portion 29, so that the first transport guide 25 is rotated downward (clockwise in FIG. 3B). The movement is restricted, and the second protrusion 25c comes into contact with the restriction part 29, whereby the upward rotation of the first conveyance guide 25 (counterclockwise in FIG. 3B) is restricted. As a result, the rotation of the first conveyance guide 25 is restricted by the restriction unit 29, and the sheet 6 can be stably guided downstream.

  On the other hand, when the first conveyance guide 25 moves to the outside (A direction) with respect to the axial direction to a position where the first and second projecting portions 25b and 25c do not come into contact with the restriction portion 29, the first conveyance guide 25 becomes the restriction portion. The restriction of the rotation by 29 is released. Therefore, when the first transport guide 25 moves to the attachment / detachment position (see FIG. 4), the first transport guide 25 can freely rotate. Thereby, as above-mentioned, the 1st conveyance guide 25 and the 1st engaging part 26 can be rotated, and the 1st conveyance guide 25 can be detached from the shaft 24.

  The second transport guide 27 has the same configuration as the first transport guide 25, and moves the second transport guide 27 to a position where the second engagement portion 28 overlaps the notch portion 24a of the shaft 24 in the axial direction. Thus, the second conveyance guide 27 can be rotated and detached from the shaft 24 (see FIG. 10). Further, the second transport guide 27 is also provided with a projecting portion and a restricting portion similar to the first and second projecting portions 25 b and 25 c and the restricting portion 29 of the first transport guide 25.

  Next, operations of the first and second transport guides 25 and 27 and the shaft 24 will be described. 4 is a top view showing a state in which the first conveyance guide has moved in the axial direction to the attachment / detachment position, and FIG. 4 (b) is a side view seen from the direction A in FIG. 4 (a). FIG. FIG. 6A is a top view showing a state in which the first transport guide is rotated upward, and FIG. 6B is a side view seen from the direction A of FIG. 6A. FIG. 7A is a top view showing a state in which the first conveyance guide is detached from the shaft, and FIG. 7B is a side view seen from the direction A in FIG. FIG. FIG. 9 is a perspective view showing a state in which the second paper feed roller moves on the shaft in a direction away from the separation pad. Portions common to FIGS. 2 and 3 are denoted by common reference numerals, and description thereof is omitted.

  2 and 3, the stop ring (not shown) of the first conveyance guide 25 is removed, and as shown in FIGS. 4A, 4 </ b> B, and 5, the first conveyance is performed. The guide 25 is moved to the attachment / detachment position where the first engagement portion 26 overlaps the notch portion 24a outward in the axial direction (A direction in the drawing). By such movement of the first conveyance guide 25, the first and second protrusions 25b, 25c of the first conveyance guide 25 and the restricting portion 29 do not come into contact with each other, and the first conveyance guide 25 can freely rotate. .

  Then, as shown in FIGS. 6A and 6B, when the first conveyance guide 25 is rotated upward (here, counterclockwise in FIG. 6B), the first engagement portion 26 is moved. The first opening 26 a can be made to coincide with the notch 24 a of the shaft 24.

  From this state, as shown in FIGS. 7A and 7B, when the first conveyance guide 25 is pulled upward, the engagement between the first engagement portion 26 and the shaft 24 can be released. . Thereby, as shown in FIG. 8, the first conveyance guide 25 can be detached from the shaft 24. Further, it is possible to move the second paper feed roller 22 on the shaft 24 toward the outside in the axial direction (downward in the A direction).

  Then, as shown in FIG. 9, the second paper feed roller 22 is separated on the outer side (downstream in the direction A in the figure) opposite to the second conveyance guide 27 in the axial direction, that is, the second paper feed roller 22 is separated. By moving away from the pad 23, the separation pad 23 hidden behind the second paper feed roller 22 appears. Thereby, access to the separation pad 23 becomes possible.

  With the above configuration, the first transport guide 25 can be easily detached from the shaft 24 only by moving in the axial direction. Further, the separation pad 23 can be easily accessed without removing the second paper feed roller 22 simply by moving the second paper feed roller 22 in the axial direction by detachment of the first transport guide 25. Accordingly, it is possible to facilitate access to the separation pad 23 and to perform the replacement operation easily and in a short time with a simple operation.

  FIG. 10 is a perspective view illustrating a state in which the second transport guide moves in the axial direction to the attachment / detachment position. Further, as shown in FIG. 10, the second transport guide 27 is moved from the sheet guide position (first position) toward the second paper feed roller 22 side (downward in the direction A in the drawing) with respect to the axial direction. 2 The second engagement portion 28 of the transport guide 27 can move to the attachment / detachment position (second position) where it overlaps the notch 24a of the shaft 24 (solid arrow).

  And although not shown in figure, similarly to the above-mentioned 1st conveyance guide 25, the 2nd conveyance guide 27 is rotated upwards in an attachment / detachment position, and the 2nd opening part (opening part) 28a and the notch part 24a of the shaft 24 are carried out. After matching, it can be detached from the shaft 24 by pulling upward. As described above, by removing the second conveyance guide 27 from the shaft 24 in addition to the first conveyance guide 25, access to the separation pad 22 is further facilitated.

  Here, since the second paper feed roller 22 is disposed in the axial center of the shaft 24 and the first and second transport guides 25 and 27 are disposed on the shaft 24 with the second paper feed roller 22 interposed therebetween, the sheet 6 ( 1) can be transported more stably. Further, since the first and second transport guides 25 and 27 can be detached from the shaft 24, access to the separation pad 23 can be further facilitated.

  On the other hand, after the separation pad 23 is replaced, the second conveyance guide 27 is engaged with the shaft 24 and mounted by the reverse operation to the above, and the second paper feed roller 22 is positioned to form a nip with the separation pad 23. The first conveyance guide 25 can be engaged with the shaft 24. Alternatively, the first and second transport guides 25 and 27 can be engaged with the shaft 24 after the second paper feed roller 22 is moved to the nip formation position. In this way, the first and second transport guides 25 and 27 can be easily attached.

  Next, replacement (detachment) of the separation pad 23 will be described. 11 is a perspective view showing an arrangement state of the separation pad, FIG. 12 is an enlarged perspective view showing the periphery of the separation pad in FIG. 11, and FIG. 13 is a perspective view showing a state in which the separation pad is lying down. 14 is an enlarged perspective view of the periphery of the separation pad in FIG. 13, FIG. 15 is a top view showing the engagement state of the separation pad as viewed from above in FIG. 14, and FIG. It is a top view which shows the state by which the match was cancelled | released. In FIG. 11, for convenience of explanation, the second paper feed roller 22 and the shaft 24 are omitted.

  As shown in FIGS. 11 and 12, a support portion 21a for supporting the separation pad 23 is provided substantially vertically on the bottom surface of the frame 21, and the separation pad 23 is supported by the support portion 21a. Yes. Further, as shown in FIGS. 13 and 14 to be described later, a cutout hole 21ab and a fixing portion 21ac for fixing the separation pad 23 are formed in the support portion 21a.

  As shown in FIGS. 11 and 12, the separation pad 23 includes a support member 31 and a pad portion 32, and the support member 31 is supported by the support portion 21 a of the frame 21 and supports the pad portion 32. ing. The support member 31 is substantially U-shaped, and a pad portion 32 is supported on the bottom of the U-shape, and a protruding portion 33 is projected on the outer surface of the distal end portion of both protruding piece portions 31a ( (Refer FIG. 15, FIG. 16).

  When the protrusion 33 is fitted (engaged) in the engagement hole 21aa formed in the support portion 21a, the support member 31 is rotatably supported by the support portion 21a. The protrusion 33 is configured to be engaged and released from the engagement hole 21aa when the protruding piece 31a of the support member 31 is bent.

  As a result, the support member 31 stands substantially vertically from the bottom surface of the frame 21 as shown in FIGS. 11 and 12 and is supported by the support portion 21a, and upstream of the sheet conveyance direction as shown in FIGS. It is possible to rotate between a side (lower right in the figure) and a state of lying down substantially parallel to the bottom surface of the frame 21.

  As shown in FIGS. 13 and 14, a handle portion 31 b having a substantially L shape that protrudes inward and is bent upward in the drawing is formed on the inner surface of the tip end portion of the protruding piece portion 31 a of the support member 31. ing. The protruding end portions 31ba of the handle portion 31b are arranged at a predetermined interval from each other. The protruding end 31ba penetrates the cutout hole 21ab formed in the support portion 21a when the support member 31 is erected.

  Thus, the protruding end portion 31ba does not prevent the separation pad 23 from being supported by the support portion 21a. In addition, a fixing portion 34 that can be fixed to and released from the fixing portion 21ac formed on the support portion 21a is formed on the side surface opposite to the pad portion 32 in the bottom portion of the U-shape of the support member 31. .

  The fixing portion 34 is fixed to the fixing portion 21ac by being pushed into the fixing portion 21ac, and is fixed to the fixing portion 21ac by being pulled out. Accordingly, when the support member 31 is erected and the fixing portion 34 is pushed into the fixing portion 21ac, the separation pad 23 is supported by the support portion 21a as shown in FIGS.

  On the other hand, when the separation pad 23 is pulled out from this state, the fixation of the fixing portion 34 with the fixing portion 21ac can be released, and the separation pad 23 is laid down as shown in FIGS. Can do. Further, when the separation pad 23 falls down, the protruding end portion 31ba of the handle portion 31b protrudes upward.

  Then, with the separation pad 23 lying down as shown in FIG. 15, the two projecting end portions 31ba are grasped by fingers from the outside and are pressed toward the inside, thereby supporting the support member as shown in FIG. The protruding piece part 31a of 31 can bend inward, and the projection part 33 can be removed from the engagement hole 21aa of the support part 21a (disengagement). Thereby, the separation pad 23 can be detached from the support portion 21a.

  Therefore, the separation pad 23 can be easily detached from the frame 21 after the separation pad 23 appears as described above. However, the method of supporting the separation pad 23 on the frame 21 is not particularly limited. For example, the fixing member 34 is fixed to the support member 31 of the separation pad 23 without providing the handle portion 31b or the protrusion 33. It can also be fixed to 21ac.

  On the other hand, when attaching the separation pad 23 to the frame 21, the projecting end portion 31 ba is grasped on both outer sides by the procedure reverse to the above, and the projecting piece portion 31 a of the support member 31 is bent inward to form the projecting portion 33. What is necessary is just to insert in the engagement hole 21aa of the support part 21a of the flame | frame 21, and to turn the isolation | separation pad 23 upright and to fix to the support part 21a. Then, after mounting the separation pad 23 on the frame 21 in this way, the first and second transport guides 25 and 27 can be mounted on the shaft 24 as described above.

  Since the separation pad 23 is used here, it is easy to access the separation pad 23 that is more easily worn and frequently replaced, which is effective. However, the separation member of the present invention is not particularly limited to the separation pad 23 of the present embodiment, and a separation roller or the like can also be used.

  In addition, this invention is not limited to the said embodiment, A various change is possible in the range which does not deviate from the meaning of this invention. For example, the shape, quantity, arrangement, etc. of the cutout portion 24a, the first and second transport guides 25, 27 and the first and second engagement portions 26, 28 can be set as appropriate according to the device configuration and the like. . In this embodiment, a monochrome printer is described as an example of the image forming apparatus. However, the present invention can be applied to other image forming apparatuses such as a tandem color printer, a copying machine, and a facsimile.

  The present invention separates and conveys sheets one by one, and forms a nip between the sheet feeding roller for conveying the sheet and the sheet feeding roller to separate the sheets one by one. A sheet feeding device having a separating member and a sheet guide that guides a sheet to the downstream side of the sheet feeding roller, and is disposed in proximity to the sheet feeding roller, the rotation of the sheet feeding roller The shaft has a cutout portion formed by cutting out a part of the outer peripheral surface at a predetermined position with respect to the axial direction of the rotating shaft, and supports the paper feed roller so as to be movable in the axial direction. And the conveyance guide has a substantially C-shaped cross section having a part of an opening that is allowed to pass through the cutout portion of the rotating shaft, and the opening passes through the cutout portion. Engageable and disengageable with the rotation shaft A joint portion is projected, and the conveyance guide is rotatable about the rotation shaft by the engagement of the engagement portion with the rotation shaft, and the engagement portion is cut along the axial direction. The first position adjacent to the paper feed roller without overlapping with the notch and the second position overlapping with the notch are pivotally supported so as to move the sheet to the downstream side at the first position. And detachable from the rotary shaft at the second position, and by moving the transport guide from the first position to the second position and detaching from the rotary shaft, The paper feed roller is movable on the rotating shaft in a direction away from the separating member.

  Accordingly, it is possible to easily access the separating member and perform the replacement operation easily and in a short time with a simple operation. Further, by providing a restricting portion that can restrict the rotation of the conveyance guide when the conveyance guide is disposed at the first position, the sheet can be guided more stably to the downstream side.

  In addition, the sheet feeding roller is arranged in the center in the axial direction of the rotation shaft, and the two conveyance guides are arranged with the sheet feeding roller sandwiched between the rotation shaft, so that the sheet can be conveyed more stably, Since the conveyance guides adjacent to both sides of the paper feed roller can be separated from the separation member, access to the separation member can be further facilitated.

  In addition, by using a separation pad as the separation member, it is effective because it is easy to access the separation pad that is more easily worn and frequently replaced. In addition, by forming an image forming apparatus including the above-described paper feeding device, it is possible to perform image formation in which the influence of paper feeding failure is prevented.

20 Paper feeder 21 Frame 21a Support portion 21aa Engagement hole 22 Second paper feed roller (paper feed roller)
23 Separation pad (separation member)
24 Shaft 24a Notch 25 First transport guide (transport guide)
26 1st engaging part (engaging part)
26a First opening (opening)
27 Second transport guide (transport guide)
28 Second engaging portion (engaging portion)
28a Second opening (opening)
DESCRIPTION OF SYMBOLS 29 Restriction part 31 Support member 31a Projection piece part 31b Handle part 31ba Projection end part 32 Pad part 33 Projection part 100 Image forming apparatus

Claims (5)

Separating and conveying the sheets one by one, a sheet feeding roller for conveying the sheet, a separation member for forming a nip between the sheet feeding rollers and separating the sheets one by one, A sheet guide device that guides a sheet to the downstream side of the sheet feed roller, and a conveyance guide that is disposed in proximity to the sheet feed roller,
The rotation shaft of the paper feed roller has a notch formed by cutting out a part of the outer peripheral surface at a predetermined position with respect to the axial direction of the rotation shaft, and the paper feed roller in the axial direction. I support it to move,
The conveyance guide has a substantially C-shaped cross-section partially including an opening that is allowed to pass through the cutout portion of the rotation shaft, and the rotation is performed when the opening passes through the cutout portion. An engaging portion that can be engaged with and disengaged from the shaft in a rotatable manner is provided,
The conveyance guide is rotatable about the rotation shaft by the engagement of the engagement portion with the rotation shaft, and the engagement portion does not overlap the notch portion along the axial direction. The first position adjacent to the sheet feed roller and the second position overlapping the notch are movably supported, and guide the sheet to the downstream side at the first position, and the second position It can be attached to and detached from the rotating shaft at the position of
By moving the transport guide from the first position to the second position and detaching from the rotating shaft, the feeding roller can be moved on the rotating shaft in a direction away from the separating member. A sheet feeding device characterized by:   The sheet feeding device according to claim 1, further comprising a restricting portion capable of restricting rotation of the transport guide when the transport guide is disposed at the first position. The paper feed roller is disposed at a central portion in the axial direction of the rotation shaft,
3. The sheet feeding device according to claim 1, wherein two conveyance guides are arranged with the sheet feeding roller interposed between the rotation shafts.   The sheet feeding device according to claim 1, wherein the separation member is a separation pad.   An image forming apparatus comprising the paper feeding device according to claim 1.

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