JP6601344B2 - Paper feeding device and image forming apparatus - Google Patents

Description

    The present invention relates to a paper feeding device that feeds paper and an image forming apparatus including the paper feeding device.

  In an image forming apparatus such as a copying machine or a printer, a sheet on which an image is formed is fed from a sheet feeding cassette or the like to an image forming unit by a sheet feeding device. The paper feeder includes a paper feed roller that feeds paper from the paper feed cassette, a transport roller that transports the fed paper to the image forming unit, a retard roller that transports the paper one by one while preventing multiple paper feeds, Is provided. Since these rollers are in contact with the paper, wear occurs due to friction with the paper. As wear progresses, poor paper feeding occurs, and it is preferable that maintenance and replacement of these rollers can be facilitated.

  The conveyance path of the sheet fed from the sheet feeding device differs depending on the specifications of the image forming apparatus. As a conveyance path, a sheet feeding device is arranged on the front side of the image forming apparatus, and an S path path through which a sheet is conveyed in a substantially S shape, or a substantially C-shaped reversal conveyance path along the back surface of the image forming apparatus. The rear C path route provided with is generally used. In the case of the S path route, the retard roller can be arranged in the paper feed cassette, and the paper feed roller and the transport roller can be arranged in the apparatus main body, so that it becomes easy to separate the retard roller from the paper feed roller and the transport roller. Exchange of each roller is easy. However, in the case of the rear C path, each roller is disposed on the rear side of the apparatus main body, so that replacement is not easy.

  Further, in the paper feeding device described in Patent Document 1, the paper feeding roller and the transport roller are supported by a holder, the holder is detachably provided on the device main body, the holder is removed from the device main body, and each roller is replaced. It can be done.

JP 2001-294335 A

  However, in the paper feeding device described in Patent Document 1, when the holder is attached to and detached from the apparatus main body, the rotation shaft of the transport roller supported by the holder and the drive input shaft provided in the apparatus main body are It is necessary to position in the direction. For example, in the case of an image forming apparatus having a rear C path, since the holder is disposed on the rear side of the apparatus main body as described above, the positioning operation of the rotating shaft and the drive input shaft and the replacement operation of the holder are complicated. Become.

  In view of the above circumstances, an object of the present invention is to provide a sheet feeding device that facilitates maintenance and replacement of each roller by facilitating the attachment and detachment of the holder, and an image forming apparatus including the sheet feeding device. .

  In order to solve the above-described problems, a sheet feeding device according to the present invention includes a pickup roller that feeds a sheet, a feed roller that rotates around a rotation shaft and conveys the fed sheet along a conveyance path, and the pickup roller. And a feed frame that supports the feed roller, a support frame having a receiving recess that is detachably supported along a direction intersecting the axial direction of the rotation shaft, and A drive input shaft that is pivotally supported by the support frame on one side in the axial direction and that is coupled to the rotation shaft and transmits a driving force to the rotation shaft. A pair of side wall portions that are provided along the direction and are opposed to each other in the axial direction, and are provided on the pair of side wall portions along the attachment / detachment direction. A predetermined position at which the drive input shaft and the rotation shaft are arranged coaxially on a guide portion that is guided so as to be able to ride, and the paper feed holder that is provided along the guide portions and is guided along the pair of side walls. And a positioning portion that is positioned on the other side wall portion on the other side in the axial direction, and the paper feeding holder is moved in the axial direction as the paper feeding holder slides to the predetermined position along the guide portion. And a pressing portion that presses one side to connect the rotating shaft to the drive input shaft.

  By adopting such a configuration, it is possible to connect the rotation axis of the feed roller and the drive input shaft by simply sliding the paper feed holder to a predetermined position along the guide portion. It becomes.

  In the paper feeding device of the present invention, the one end portion of the rotary shaft and the one end portion of the drive input shaft are engaged with each other so as to connect the rotary shaft and the drive input shaft so as to be integrally rotatable. And a portion to be engaged, and a holder urging member for urging the paper feed holder to one side in the axial direction at the predetermined position and pressing the engagement portion against the engaged portion. When the drive input shaft rotates and the phase of the engaging portion and the phase of the engaged portion coincide with each other, the engaging portion and the engaged portion engage with each other, The drive input shaft may be connected.

  By adopting such a configuration, the engaging portion and the engaged portion can be reliably engaged.

  In the paper feeding device of the present invention, the paper feeding holder includes a cylindrical first shaft portion and a cylindrical second shaft portion that respectively support both end portions of the rotation shaft on the pair of side wall portions. The positioning portion includes a first bearing portion that supports the first shaft portion, and a portion along a circumferential direction is cut out at a proximal end portion of the first shaft portion. A small diameter portion having an outer diameter smaller than the outer diameter of the shaft portion is provided, and the first bearing portion is provided with a notch along the direction intersecting the axial direction through which the small diameter portion can pass. When the paper feed holder is slid along the guide portion, the small diameter portion enters the first bearing portion from the notch, and the outer peripheral surface of the small diameter portion contacts the inner peripheral surface of the first bearing portion. The paper feed holder is positioned at the predetermined position by regulating the slide of the paper feed holder. It may be characterized in that it is.

  By adopting such a configuration, it is possible to position the paper feed holder at a predetermined position where the rotation axis of the feed roller and the drive input shaft are coaxially arranged by simply sliding the paper feed holder along the guide portion. Therefore, it is possible to easily position the paper feed holder at the alignment position.

  An image forming apparatus according to the present invention includes any of the above-described sheet feeding devices.

  In the image forming apparatus of the present invention, the image forming apparatus includes an opening / closing unit that is pivotable about a lower end portion and opens or forms a conveyance path downstream of the feed roller in the conveyance direction. There may be provided a restricting portion for preventing movement of the sheet feeding holder to the other side in the axial direction when the sheet is rotated so as to form the conveyance path.

  By adopting such a configuration, the movement of the paper feed holder is prevented by rotating the open / close unit so as to form a transport path, so that the paper feed holder can be prevented from being unintentionally detached from the housing recess. Can be prevented.

  In the image forming apparatus according to the aspect of the invention, the restricting portion is a rib that enters between the side wall portion on the other axial side of the housing recess and the paper feed holder, and the paper feed holder contacts the rib. Thus, the movement of the paper feed holder in the other axial direction may be prevented.

  By adopting such a configuration, the space of the housing recess can be effectively utilized.

  In the image forming apparatus of the present invention, a notch is formed at a lower edge of the opening / closing unit at a position corresponding to the paper feed holder, and the opening / closing unit is rotated so as to open the conveyance path. In addition, the paper feed holder may be detachable through the notch.

  By adopting such a configuration, it is possible to easily attach and detach the paper feed holder.

  According to the present invention, the paper feed holder is slid in a direction intersecting the axial direction of the rotation axis of the feed roller to position the rotation axis and the drive input shaft at a predetermined position on the same axis, and the rotation axis And the drive input shaft can be connected, so that the attachment and detachment work of the paper feed holder can be facilitated.

1 is a front view schematically showing an internal structure of a color printer according to an embodiment of the present invention. FIG. 3 is a perspective view illustrating a transport unit of a color printer according to an embodiment of the present invention. It is a perspective view showing a paper feeder concerning one embodiment of the present invention. It is a longitudinal cross-sectional view which shows the paper feeder which concerns on one Embodiment of this invention. FIG. 6 is a perspective view showing a first side wall portion of an upper receiving recess of the upper support frame in the paper feeding device according to the embodiment of the present invention. FIG. 6 is a perspective view showing a second side wall portion of the upper receiving recess of the upper support frame in the paper feeding device according to the embodiment of the present invention. FIGS. 7A and 7B are a perspective view and a holder urging member, respectively, illustrating a rib and a holder urging member provided on the upper support frame in the paper feeding device according to the embodiment of the present invention. FIG. FIG. 6 is a longitudinal sectional view showing a lower accommodating recess of the lower support frame in the sheet feeding device according to the embodiment of the present invention. 1 is a perspective view showing a paper feed holder in a paper feed device according to an embodiment of the present invention. FIG. 10A is a perspective view showing first and second shaft portions of a paper feed holder in the paper feeding device according to the embodiment of the present invention, FIG. 10A is the first shaft portion, and FIG. The shank is shown. FIG. 11A is a front cross-sectional view showing the rotation axis of the feed roller and the drive input shaft in the sheet feeding device according to the embodiment of the present invention, and FIG. 11A shows the rotation axis and the drive input shaft aligned in the axial direction. FIG. 11B shows a state in which the rotating shaft and the drive input shaft are connected. FIG. 12B is a perspective view showing the paper supply holder in the upper housing recess in the paper supply device according to the embodiment of the present invention, and FIG. 12A shows the paper supply holder before contacting the rib, and FIG. ) Shows the paper feed holder which has started to be guided in the axial direction by the rib, and FIG. 12C shows the paper feed holder slid to a predetermined position. FIG. 13A is a perspective view showing a drive input shaft and a rotary shaft in the paper feeding device according to the embodiment of the present invention, and FIG. 13A shows a state in which the drive input shaft and the rotary shaft are in contact with each other. FIG. 13B shows a state in which the phases of the engagement hole of the drive input shaft and the engagement projection of the rotary shaft coincide with each other. FIG. 13C shows the engagement projection of the rotary shaft in the engagement hole of the drive input shaft. The engaged state is shown. FIG. 5 is a side sectional view showing an intermediate guide and an upper support frame that are rotated rearward in the paper feeding device according to the embodiment of the present invention. FIG. 6 is a side cross-sectional view showing an intermediate guide and an upper support frame that are rotated forward in the paper feeding device according to the embodiment of the present invention. FIG. 5 is a front view showing an intermediate guide and an upper support frame that are rotated forward in the paper feeding device according to the embodiment of the present invention.

  Hereinafter, an image forming apparatus and a sheet feeding device according to an embodiment of the present disclosure will be described with reference to the drawings.

  First, an overall configuration of a color printer 1 as an image forming apparatus according to the present embodiment will be described with reference to FIGS. 1 and 2. FIG. 1 is a cross-sectional view schematically showing the internal structure of the color printer 1, and FIG. 2 is a perspective view showing a transport unit. In the following description, the left direction in FIG. 1 is the front side (front side) of the color printer, and the left-right direction is based on the direction when the color printer is viewed from the front side.

  As shown in FIG. 1, the color printer 1 includes a box-shaped housing 2. A manual feed tray 3 is provided on the front surface of the housing 2. On the upper surface of the housing 2, a paper discharge tray 4 for discharging paper is formed. An opening 2 a is formed on the rear surface of the housing 2. The opening 2 a is opened and closed by the opening / closing unit 5. The opening / closing unit 5 includes a rear cover 6 that covers the opening 2 a, a transport unit 7 that is provided inside the rear cover 6, and an intermediate guide 8 that is provided inside the transport unit 7. The rear cover 6 is supported by the housing 2 so as to be rotatable about a fulcrum 6a at the lower end. As shown in FIG. 2, a support shaft 7 a is provided at the lower end of the transport unit 7. The support shaft 7a is rotatably supported by a bearing portion (not shown) provided in the housing 2 slightly above the support point 6a of the rear cover 6. In addition, a rectangular notch 7 b is formed at the lower edge of the transport unit 7 at the center in the left-right direction. The intermediate guide 8 is rotatably supported on the support shaft 7 a of the transport unit 7. The intermediate guide 8 will be described later.

  A paper feed cassette 9 in which the paper S is accommodated is detachably accommodated in the lower part of the housing 2. The paper feed cassette 9 is provided with an elevating plate 9a on which the sheets S are stacked, and a spring member 9b that urges the rear end portion of the elevating plate 9a upward. A paper feeding device 10 that feeds the paper S from the paper feeding cassette 9 is provided behind the paper feeding cassette 9. The paper feeder 10 will be described later. An exposure device 11 composed of a laser scanning unit (LSU) is provided above the paper feed cassette 9. Above the exposure device 11, an intermediate transfer unit 13 and a lower portion of the intermediate transfer unit 13 are provided. And four image forming units 14 arranged for each color of toner.

  The intermediate transfer unit 13 includes an intermediate transfer belt 16 provided between a plurality of rollers, and four primary transfer rollers 17 that are arranged inside the intermediate transfer belt 16 in the front-rear direction. Each image forming unit 14 includes a photosensitive drum 18 that is rotatably provided, a charging device 19 that is sequentially arranged around the photosensitive drum 18 along the rotation direction of the photosensitive drum 18, a developing device 20, and a cleaning device. A device 21 and a static eliminator 22 are included. Between the developing device 20 and the cleaning device 21, the photosensitive drum 18 faces the primary transfer roller 17 via the intermediate transfer belt 16, and the primary transfer unit 24 is interposed between the photosensitive drum 18 and the intermediate transfer belt 16. Is forming. Above the intermediate transfer unit 13, four toner containers 26 corresponding to each image forming unit 14 are mounted for each toner color (Y, M, C, K).

  Further, on the rear side of the intermediate transfer unit 13, a secondary transfer roller 27 that forms a secondary transfer portion 28 with the intermediate transfer belt 16 is rotatably supported by the transport unit 7 (see FIG. 2). . A registration roller pair 25 is provided below the secondary transfer unit 28 (upstream in the transport direction). Further, a fixing device 29 is provided above the secondary transfer unit 28, and a paper discharge device 30 facing the paper discharge tray 4 is provided above the fixing device 29.

  Inside the housing 2, a main transport path 33, a manual transport path 34, and a duplex printing path 35 for the paper S are formed. The main transport path 33 is formed along the inner side of the transport unit 7 from the paper feeder 10 through the rear cover 6 and the intermediate guide 8. The registration roller pair 25, the secondary transfer unit 28, the fixing device 29, and the paper discharge device 30 are arranged along the main transport path 33 in order from the upstream side in the transport direction. The manual feed path 34 is formed so as to join the main feed path 33 along the intermediate guide 8 on the upstream side of the registration roller pair 25 from the manual feed tray 3 through the upper part of the sheet feeding cassette 9. . The duplex printing path 35 is formed so as to be curved in a substantially C shape between the rear cover 6 and the transport unit 7 and to join the main transport path 33 along the intermediate guide 8 on the upstream side of the registration roller pair 25. Yes.

  Next, an image forming operation of the color printer 1 having such a configuration will be described. In each image forming unit 14, after the surface of the photosensitive drum 18 is charged by the charging device 19, the photosensitive drum 18 is exposed to the image data by the laser beam from the exposure device 11, and the photosensitive member is exposed. An electrostatic latent image is formed on the surface of the drum 18. The electrostatic latent image is developed into a corresponding color toner image by the developing device 20, and the toner image is primarily transferred to the surface of the intermediate transfer belt 16 in the primary transfer unit 24. Each image forming unit 14 sequentially repeats the above operation, whereby a full-color toner image is formed on the intermediate transfer belt 16. Note that the toner and charge remaining on the photosensitive drum 18 are removed by the cleaning device 21 and the static eliminator 22.

  On the other hand, the paper S taken out from the paper feed cassette 9 by the paper feeding device 10 is conveyed to the secondary transfer unit 28 along the main conveyance path 33 in synchronization with the above-described image forming operation, and the secondary transfer unit 28. 2, the full-color toner image on the intermediate transfer belt 16 is secondarily transferred to the paper S. The sheet S on which the toner image is secondarily transferred is conveyed downstream through the main conveyance path 33 and enters the fixing device 29, where the toner image is fixed on the sheet. The paper S on which the toner image is fixed is discharged from the paper discharge device 30 to the paper discharge tray 4. When duplex printing is performed, a sheet on which an image is formed on one side is conveyed along the main conveyance path 33 from the duplex printing path 35 and an image is formed on the other side. Discharged from. The sheet fed from the manual feed tray 3 is transported from the manual transport path 34 to the main transport path 33 and image formation is performed in the same manner.

  When handling a paper jam occurring in the main transport path 33, the main transport path 33 is opened by rotating the rear cover 6 and the transport unit 7 downward. Further, when handling a paper jam occurring in the manual feed path 34, the manual feed path 34 is opened by turning the open / close unit 5 (rear cover 6, transport unit 7, intermediate guide 8) downward. The double-sided printing path 35 is opened by rotating the rear cover 6 downward.

  Next, the paper feeding device 10 will be described with reference to FIGS. 3 and 4. FIG. 3 is a perspective view of the paper feeding device 10, and FIG. 4 is a cross-sectional view of the paper feeding device 10.

  The sheet feeding device 10 accommodates an upper support frame 41 and a lower support frame 42, a pickup roller 44, and a feed roller 45 that are arranged above and below the main transport path 33 (see FIG. 4). A sheet feed holder 46 that is detachably supported, a retard holder 49 that accommodates a retard roller 48 and is detachably supported by the lower support frame 42, and a stopper 50 that prevents the retard holder 49 from coming off are provided. .

  The upper support frame 41 will be described with reference to FIGS. FIG. 5 is a perspective view of the upper housing recess viewed from the right rear, FIG. 6 is a perspective view of the upper housing recess viewed from the left rear, and FIG. 7 is a perspective view of the holder urging member.

  The upper support frame 41 is provided along the paper width direction (left-right direction) intersecting the transport direction. On the lower surface of the upper support frame 41, a plurality of ribs inclined rearward and obliquely upward are provided to form an upper guide surface of the main transport path 33. On the upper surface of the upper support frame 41, a plurality of ribs inclined rearward and upward are provided to form a lower guide surface of the manual conveyance path. On the lower surface of the upper support frame 41, an upper receiving recess 51 is formed at the center in the paper width direction as a mounting portion on which the paper feed holder 46 is detachably supported.

  As shown in FIGS. 5 and 6, the upper accommodating recess 51 has a rear surface (surface on the downstream side in the transport direction) and a lower surface that are open, and a first side wall as a pair of wall portions facing each other in the paper width direction. It has the part 51a and the 2nd side wall part 51b, the upper wall part 51c, and the front wall part 51d.

  Boss hole-shaped first bearing portions 57 and second bearing portions 58 are respectively provided in the rear end portions (end portions on the downstream side in the transport direction) of the first side wall portion 51a and the second side wall portion 51b. Are formed on the same axis. As will be described later, the first bearing portion 57 functions as a positioning portion that positions the rotation shaft 45b of the feed roller 45 and the drive input shaft 53 at a predetermined position on the same axis. As shown in FIG. 5, a notch 59 communicating with the first bearing portion 57 is formed in the rear end edge 51e of the first side wall portion 51a. The width of the notch 59 is smaller than the inner diameter of the first bearing portion 57. On the other hand, as shown in FIG. 6, on one side (right side) of the second bearing portion 58 in the sheet width direction, the drive input shaft 53 for transmitting the driving force of the feed roller 45 rotates to the upper support frame 41. Supported as possible. An engagement hole 53 a having an oval cross section is formed on the distal end surface of the drive input shaft 53. The engagement hole 53a is engaged with an engagement protrusion 91 (see FIG. 9) having an oval cross section formed on the tip end surface of the rotation shaft 45b of the feed roller 45, so that the feed roller 45 and the drive input shaft 53 are integrated. It is formed as an engaged portion that is rotatably connected.

  Furthermore, the first side wall 51a and the second side wall 51b are guided above the first bearing 57 and the second bearing 58 so that the paper feed holder 46 can slide along the front-rear direction (conveyance direction). Guide grooves 55 as guide portions to be formed are formed to face each other. The guide groove 55 extends forward while inclining downward from the opening end 55a that opens rearward (in the downstream direction in the transport direction) toward the closing end 55b.

  As shown in FIG. 5, a rib 61 as a pressing portion that presses the paper supply holder 46 toward the second side wall 51b is formed at the front end (upstream side end in the transport direction) of the first side wall 51a. Has been.

  The rib 61 is formed to protrude substantially horizontally along the lower edge of the first side wall 51a in a direction orthogonal to the first side wall 51a and the front wall 51d. The rib 61 has an inclined edge 61a inclined inward toward the front, and a parallel edge 61b parallel to the first side wall 51a.

  Further, an opening 63 is formed above the rib 61 at the front end of the first side wall 51a. As shown in FIG. 7A, a hollow accommodating portion 64 is formed on the back side (left side) of the opening 63. A holder urging member 66 is accommodated in the accommodating portion 64. As shown in FIG. 7B, the holder urging member 66 urges the pressing member 67 in a direction in which the pressing member 67 protrudes from the opening 63 and the pressing member 67 that can be protruded through the opening 63 in the upper housing recess 51. And a coil spring 68. The pressing member 67 has a shaft portion 67 a whose tip is triangular in plan view and a size smaller than the size of the opening 63, and a base portion 67 b whose size is larger than the size of the opening 63. The coil spring 68 is interposed between the base portion 67b of the pressing member 67 and the accommodating portion 64 in a slightly compressed state.

  The pressing member 67 is urged by the coil spring 68 in the direction toward the upper housing recess 51, the base portion 67 b is locked around the opening 63, and the shaft portion 67 a projects through the opening 63 into the upper housing recess 51. ing. When the pressing member 67 is pushed in against the urging force of the coil spring 68, the tip of the shaft portion 67a is retracted from the upper housing recess 51 (see the two-dot chain line in FIG. 7B).

  The lower support frame 42 will be described with reference to FIGS. 3 and 8. FIG. 8 is a side view showing the lower accommodating recess. The lower support frame 42 is provided along the paper width direction. The upper surface of the lower support frame 42 is curved rearward and upward to form a lower guide surface of the main transport path 33. The lower support frame 42 is formed with a lower receiving recess 71 having a rear surface and an upper surface opened at the center in the sheet width direction. The lower housing recess 71 is positioned to face the lower right of the upper housing recess 51.

  As shown in FIG. 8, the lower housing recess 71 has a first side wall portion 71a and a second side wall portion facing each other in the paper width direction (only the left wall portion 71a is shown in FIG. 7). The first side wall 71a and the second side wall are formed with a notch 73 cut out from the rear edge in substantially the upper half. A semicircular engaging recess 74 is formed in the lower part of the front edge of each notch 73. Further, the first side wall 71a and the second side wall are provided with a first groove 75 extending downward from the lower edge of each notch 73, and a second groove 76 inclined downward from the front side of the lower edge toward the front. And are formed.

  Next, the paper feed holder 46 will be described with reference to FIGS. 9 is a perspective view showing the paper feed holder, FIG. 10 is a perspective view showing the left and right shaft portions of the paper feed holder, FIG. 10A shows the left shaft portion, and FIG. 10B shows the right shaft portion. Show.

  As shown in FIG. 9, the paper feed holder 46 is a substantially rectangular parallelepiped box-like member having an open bottom surface, and the front side plate 46a and the rear side plate 46b, the first side plate 46c and the first side plate 46c facing each other in the paper width direction. A two-side plate 46d and an upper plate 46e are provided.

  As shown in FIG. 10A and FIG. 10B, a first shaft portion 81 and a second shaft portion 82 are provided at the rear portions of the first side plate 46c and the second side plate 46d, respectively. The first shaft portion 81 and the second shaft portion 82 are cylindrical, and the first bearing portion 57 and the second bearing portion 58 (FIG. 5) formed in the first side wall portion 51a and the second side wall portion 51b of the upper housing recess 51. ) (See FIG. 6), each has an outer diameter that can be fitted.

  As shown in FIG. 10A, a small-diameter portion 81a having an oval cross section is provided at the proximal end portion of the first shaft portion 81. The length in the minor axis direction of the small diameter portion 81a is smaller than the outer diameter of the first shaft portion 81 and is formed to be equal to the width of the notch 59 (see FIG. 5) of the first bearing portion 57. Thereby, the small diameter portion 81 a can pass through the notch 59.

  As shown in FIG. 9, a pickup roller bearing opening 84 on which the pickup roller 44 is pivotally supported is formed coaxially at the front portion (upstream end portion in the transport direction) of the first side plate 46c and the second side plate 46d. (Only the pickup roller bearing opening 84 of the second side plate 46d is shown in FIG. 9). Further, on the outer surfaces of the first side plate 46c and the second side plate 46d, guide shafts 85 are formed coaxially so as to protrude in opposite directions from above the pickup roller bearing openings 84.

  Further, an idle gear 87 is rotatably supported on the inner surface of the second side plate 46 d between the pickup roller bearing opening 84 and the second shaft portion 82.

  The pickup roller 44 has a cylindrical roller body 44a and a rotation shaft 44b provided at the axis of the roller body 44a. A gear 88 that meshes with the idle gear 87 is fixed to one end (right side) of the rotating shaft 44b. Both end portions of the rotating shaft 44b are rotatably supported by pickup roller bearing openings 84 of the paper feed holder 46, respectively. At this time, both end portions of the rotating shaft 44b slightly protrude from the first side plate 46c and the second side plate 46d of the paper feed holder 46 and are prevented from being detached by a retaining member such as a C ring. The protruding length of the both ends of the rotating shaft 44 b from the first side plate 46 c and the second side plate 46 d is shorter than the protruding length of the guide shaft 85.

  The feed roller 45 has a cylindrical roller body 45a and a rotation shaft 45b provided at the axis of the roller body 45a. A gear 89 that meshes with the idle gear 87 is fixed to one end (right side) of the rotating shaft 45b. Both ends of the rotating shaft 45b are supported by the first side plate 46c and the second side plate 46d, respectively. On one end (right side) end surface of the rotation shaft 45b, an engagement protrusion 91 is formed as an engagement portion that is coupled to the drive input shaft 53 so as to be integrally rotatable. As described above, the engagement protrusion 91 has an oval cross-sectional shape and can be engaged with the engagement hole 53 a of the drive rotation shaft 53.

  The retard holder 49 will be described with reference to FIG. The retard holder 49 includes a support portion 49a on which the retard roller 48 is supported, and a guide portion 49b provided on the downstream side in the transport direction of the support portion 49a. Similarly to the upper surface of the lower support frame 42, the guide portion 49 b is curved obliquely in the upper right direction along the transport direction to form the lower guide surface of the main transport path 33. The retard holder 49 has protrusions (not shown) that engage with engaging recesses 74 and second grooves 76 formed in the left wall 71a and the right wall of the lower receiving recess 71 of the lower support frame 42, respectively. The protrusions are formed so as to slide obliquely rearward and upward with respect to the lower housing recess 71, so that the protrusions engage with the engagement recess 74 and the second groove 76, respectively.

  The retard roller 48 is pivotally supported on the rotating shaft via a torque limiter and stops until a torque exceeding a predetermined torque is applied. When a torque exceeding the predetermined torque is applied, the retard roller 48 idles with respect to the rotating shaft. ing. That is, when a torque exceeding a predetermined torque is applied, the retard roller 48 is driven to rotate by the pickup roller 44 and separates and transports only the uppermost sheet.

  The stopper 50 is formed with protrusions (not shown) that engage with the first grooves 75 formed in the first side wall 71a and the second side wall of the lower housing recess 71 of the lower support frame 42, respectively. The protrusion engages with the first groove 75 by sliding in the vertical direction with respect to the lower housing recess 71 to prevent the retard holder 49 from coming off. Detailed description of the retard holder 49 and the stopper 50 will be omitted.

  In the paper feeder 10 having the above-described configuration, as shown in FIGS. 3 and 4, a paper feed holder 46 in which the pickup roller 44 and the feed roller 45 are accommodated, and a retard holder 49 in which the retard roller 48 is accommodated. The upper receiving recess 51 and the lower receiving recess 71 of the lower support frame 42 are respectively mounted on the upper support frame 41. The paper feed holder 46 and the retard holder 49 are attached and detached through a notch 7 b formed at the lower edge of the transport unit 7 in a state where the rear cover 6 and the transport unit 7 are rotated to open the main transport path 33.

  A method of mounting the paper feed holder 46 in the upper housing recess 51 will be described with reference to FIGS. FIG. 11 is a cross-sectional view illustrating the process of mounting the paper feed holder, and FIG. 12 is a perspective view of the process of urging the paper feed holder in the right direction by the guide rib as viewed from below (the feed roller and the pickup roller are not shown). FIG. 13 is a perspective view showing an engagement process between the engagement protrusion and the engagement hole.

  When the paper supply holder 46 is mounted in the upper housing recess 51, the guide shaft 85 (see FIG. 9) is engaged with the guide groove 55 (see FIGS. 5 and 6) from the opening end 55a. At this time, the tip portion of the rotating shaft 44b of the pickup roller 44 protrudes below the guide groove 55, but the protruding length is short, so that it does not interfere with the first bearing portion 57 and the second bearing portion 58.

  When the guide shaft 85 is slid along the guide groove 55 with the paper feed holder 46 as close as possible to the first side wall portion 51a, the small diameter portion 81a of the first shaft portion 81 eventually removes the notch 59. It passes through and enters the first bearing portion 57. Then, as shown in FIG. 12A, the corners of the first side plate 46 c and the front side plate 46 a of the paper feed holder 46 abut on the inclined edge 61 a of the rib 61. Then, as shown in FIG. 12B, the paper feed holder 46 is pressed to the second side wall 51b side (one axial direction, rightward) along the inclined edge 61a of the rib 61, and the first The biaxial portion 82 begins to enter the second bearing portion 58. Further, the front end portion of the first side plate 46 c of the paper feed holder 46 abuts on the tip end portion of the pressing member 67 of the holder urging member 66 (see FIGS. 5 and 7), and the pressing member 67 is attached to the coil spring 68. It is pushed into the accommodating portion 64 against the force. In other words, the paper feed holder 46 is given a biasing force in the direction (right direction) from the coil spring 68 to the second side wall 51b.

  Further, the guide shaft 85 is slid along the guide groove 55, and as shown in FIG. 12C, the angle between the first side plate 46c and the front side plate 46a of the paper feed holder 46 is the inclined edge 61a of the rib 61. When the parallel edge 61b is reached, the second shaft portion 82 is fitted into the second bearing portion 58, and the end surface of the engaging protrusion 91 of the rotating shaft 45b is driven as shown in FIG. It is pressed against the end surface of the input shaft 53. In this state, the engaging protrusion 91 is not necessarily engaged with the engaging hole 53a (the second side plate 46d is not shown in FIGS. 13A and 13B). ing). However, when the phase of the engaging protrusion 91 and the phase of the engaging hole 53a match, the paper feeding holder 46 is pressed by the rib 61, so that the engaging protrusion 91 and the engaging hole 53a May engage. Further, the paper feeding holder 46 is biased by the holder biasing member 66 toward the second side wall 51b (rightward). At the same time, the outer peripheral surface of the small diameter portion 81a of the first shaft portion 81 comes into contact with the inner peripheral surface of the first bearing portion 57, and the slide of the paper feed holder 46 is restricted. As a result, as shown in FIG. 11A, the paper feed holder 46 is positioned at a predetermined position where the rotation shaft 45b and the drive input shaft 53 are aligned in the axial direction. Thus, the 1st bearing part 57 acts as a positioning part which positions in the predetermined position where the rotating shaft 45b of the feed roller 45 and the drive input shaft 53 are located on the same axis.

  In the state where the paper feed holder 46 is positioned at a predetermined position, the left and right guide shafts 85 are not in contact with the closed ends 55 b of the left and right guide grooves 55.

  After mounting the paper feed holder 46 in the upper receiving recess 51 in this way, the retard holder 49 is mounted in the lower receiving recess 71. When the retard roller 48 is mounted from the upper side of the lower receiving recess 71, the engaging protrusions of the guide portion 49b engage with the engaging recess 74 and the second groove 76 of the lower receiving recess 71, respectively. Further, the support portion 49a is urged in the clockwise direction of FIG. 3 by an urging member (not shown), and the retard roller 48 is in contact with the feed roller 45. Next, the stopper 50 is mounted from the upper side of the lower housing recess 71 and engaged with the first groove 75. Thereby, the movement of the retard holder 49 is regulated.

  With the paper feed holder 46 and the retard holder 49 attached, the pickup roller 44 accommodated in the paper feed holder 46 is loaded on the elevating plate 9a urged upward by the spring member 9b of the paper feed cassette 9. The uppermost sheet S is pressed against.

  Thereafter, when the drive input shaft 53 is driven to rotate the drive input shaft 53 by a predetermined angle, the phase of the engagement hole 53a of the drive input shaft 53 and the rotation shaft of the feed roller 45 are rotated as shown in FIG. The phase of the engagement protrusion 91 of 45b matches. Since the paper feed holder 46 is urged in the direction (right direction) of the second side wall 51b by the holder urging member 66, when the phase of the engagement hole 53a and the phase of the engagement protrusion 91 coincide, 13C, the paper feed holder 46 moves in the direction of the second side wall 51b, and the engaging protrusion 91 engages with the engaging hole 53a. Thereby, the rotating shaft 45b and the drive input shaft 53 are connected and rotated so as to be integrally rotatable, and the feed roller 45 is rotationally driven. Further, the pickup roller 44 rotates in the same direction as the feed roller 45 via the idle gear 87. By the rotation of the pickup roller 44, the paper S is sent out from the paper feed cassette 9 between the feed roller 45 and the retard roller 48. The drive input shaft 53 may be manually rotated until the phase of the engagement hole 53a and the phase of the engagement protrusion 91 coincide.

  When the paper feed holder 46 moves to the right, the first shaft portion 81 is fitted to the first bearing portion 57 as shown in FIG. Since the diameter of the first shaft portion 81 is larger than the width of the notch 59, the first left shaft portion 81 is prevented from coming off by the first bearing portion 57. As a result, the paper feed holder 46 is positioned in the upper accommodating recess 51.

  When one sheet S is sent out, the sheet S is transported along the main transport path 33 by the feed roller 45. On the other hand, when two or more sheets S are sent out, the uppermost sheet is conveyed by the feed roller 45, but the frictional force between the uppermost sheet S and the lower sheet is retarded by the lower sheet and the retarded sheet. Since the torque is smaller than the frictional force with the roller 48 and a torque exceeding a predetermined torque is not applied to the retard roller 48, the retard roller 48 does not rotate and the lower sheet is not conveyed. In this way, two or more sheets are spread and only the uppermost sheet S is conveyed downstream.

  As described above, in the paper feeding device 10 of the present invention, the paper feeding holder 46 is guided by the pressing portion 61 to one side in the rotational axis direction of the feed roller 45 as it slides to a predetermined position along the guide groove 55. Then, the rotation shaft 45 b of the feed roller 45 is pressed against the drive input shaft 53. Then, by rotating the drive input shaft 53 at a predetermined position, the engagement protrusion 91 of the rotation shaft 45b of the feed roller 45 and the engagement hole 53a of the drive input shaft 53 are engaged to rotate the feed roller 45. The shaft 45b and the drive input shaft 53 are automatically connected so as to be integrally rotatable. Therefore, the mounting operation of the paper feed holder 46 is simplified. Specifically, the rotation shaft 45b of the feed roller 45 and the drive input shaft 53 can be connected to each other so as to be integrally rotatable only by sliding the paper feed holder 46 along the guide groove 55.

  Further, by providing the holder urging member 66 that urges the paper feed holder 46 in the direction of the second side wall 51b, the engaging portion 91 and the engaged portion 53a can be reliably engaged. When the holder urging member 66 is not provided, when the phase of the engagement hole 53a matches the phase of the engagement protrusion 91 of the rotation shaft 45b, the rotation shafts pressed by the pressing portion 61 and in contact with each other. The engagement protrusion 91 is engaged with the engagement hole 53a by the length of the portion where 45b and the drive input shaft 53 are elastically deformed.

  When the paper feed holder 46 is slid along the guide groove 55, the outer peripheral surface of the small-diameter portion 81 a of the first shaft portion 81 comes into contact with the inner peripheral surface of the first bearing portion 57 and the paper feed holder 46. The slide is regulated, and the paper feed holder 46 is positioned at an alignment position where the rotation shaft 45b and the drive input shaft 53 are aligned in the axial direction. Therefore, the paper feed holder 46 can be easily positioned at a predetermined position.

  Next, the intermediate guide 8 and the upper support frame 41 will be described with reference to FIGS. FIG. 14 is a side sectional view showing the intermediate guide and the upper support frame rotated rearward, and FIG. 15 is a side sectional view showing the intermediate guide and the upper support frame rotated forward. FIG. 16 is a front view showing the intermediate guide and the upper support frame rotated in the forward direction.

  The intermediate guide 8 includes a guide portion 101 provided along the paper width direction and a pair of arm portions 102 provided at both ends of the guide portion 101 in the paper width direction.

  As shown in FIGS. 14 and 15, the guide portion 101 has a wedge-shaped side cross-sectional shape that is tapered toward the downstream side in the transport direction. A guide surface of the main transport path 33 is formed on the rear surface of the guide section 102, and a guide surface of the manual transport path 34 is formed on the front surface. Three rollers 104 are rotatably supported at the lower end of the front surface. The three rollers 104 are arranged at a predetermined interval on the center in the width direction and on both sides thereof.

  In addition, a regulation rib 106 is formed on the lower surface of the guide portion 101 so as to protrude from a position slightly to the left of the center in the width direction. The regulation rib 106 is L-shaped in a side view, and has a base portion 106a extending in the direction of the front surface and a tip portion 106b bent downward from the tip of the base portion 106a.

  A C-shaped shaft support portion 102 a is formed at the tip of the pair of arm portions 102. Each shaft support portion 102a is rotatably supported on a support shaft 7a (see FIG. 2) of the transport unit 7. The intermediate guide 8 can be rotated forward and backward about the support shaft 7a.

  When the intermediate guide 8 rotates forward, as shown in FIG. 15, the pair of arm portions 102 come into contact with both end portions in the width direction of the upper support frame 41, and the rear surface of the upper support frame 41 and the rear of the intermediate guide 8. A main transport path 33 that is curved upward and curved upward is formed by the side surface. Further, a manual feed path 34 is formed by the upper surface of the upper support frame 41 and the front surface of the intermediate guide 8 while being curved upward and curved upward.

  Further, as shown in FIG. 18, the leading portion 106 b of the regulation rib 106 of the intermediate guide 8 mainly includes a space between the first side wall portion 51 a of the housing recess 51 and the left side plate 46 c of the paper feed holder 46 and guidance. Enter the groove 55.

  In this way, the regulation rib 106 enters the space between the first side wall 51 a and the paper feed holder 46, so that the paper feed holder 46 accommodated in the upper accommodation recess 51 of the upper support frame 41 moves in the left direction. Is prevented.

  The paper feed holder 46 is urged rightward by a holder urging member 66, and the rotation shaft 45 b of the feed roller 45 and the drive input shaft 53 are coupled so as to be integrally rotatable. In order to move the paper feed holder 46 in the right direction in this way, the width of the housing recess 51 in the left-right direction is larger than the width of the paper feed holder 46 as shown in FIGS. 11A and 11B. Is also widely formed. Therefore, when the paper feed holder 46 is moved in the right direction in the housing recess 51, a space is opened on the right side of the first side wall 51a as shown in FIG.

  For this reason, when an impact stronger than the urging force of the holder urging member 66 is applied during transportation of the color printer 1 or the like, the first shaft portion 81 is disengaged from the first bearing portion 57 to the left side, and the paper feed holder 46 is moved. A situation may occur in which the left side of the housing recess 51 moves.

  Therefore, as shown in FIG. 15 and FIG. 16, when the intermediate guide 8 is rotated forward so that the regulating rib 106 enters the space between the first side wall 51 a and the paper feed holder 46, the paper feed holder When 46 moves to the left, the left side plate 46c of the paper feed holder 46 abuts on the regulating rib 106, and the paper feed holder 46 is prevented from moving to the left. Therefore, even when an impact is applied, the paper feed holder 46 can be supported in the housing recess 51 so as not to move. Since the space between the first side wall 51a and the paper feed holder 46 is a space originally formed in the housing recess 51 in order to move the paper feed holder 46 to the right as described above, 51 spaces can be used effectively.

  The regulating rib 106 may be formed on the transport unit 7 or the rear cover 6.

  The above description of the embodiment of the present invention describes a preferred embodiment of the paper feeding device and the image forming apparatus according to the present invention, and therefore may have various technically preferable limitations. However, the technical scope of the present invention is not limited to these embodiments unless specifically described to limit the present invention. That is, the above-described components in the embodiment of the present invention can be appropriately replaced with existing components and the like, and various variations including combinations with other existing components are possible. The description of the embodiment of the present invention described above does not limit the contents of the invention described in the claims.

1 Color printer (image forming device)
5 Opening / Closing Unit 10 Paper Feed Device 33 Main Conveyance Route (Conveyance Route)
41 Upper support frame 44 Pickup roller 45 Feed roller 45b Rotating shaft 46 Paper feed holder 48 Retard roller 51 Upper accommodation recess (accommodation recess)
51a, 51b 1st side wall part, 2nd side wall part (a pair of wall part)
53 Drive input shaft 53a Engagement hole (engaged part)
55 Guide groove (guide section)
57 1st bearing part (positioning part)
58 Second bearing portion 59 Notch 61 Rib (pressing portion)
66 Holder urging member 81 First shaft portion 81a Small diameter portion 82 Second shaft portion 91 Engaging protrusion (engaging portion)
106 Restriction part (regulation rib)

Claims (7)

A pick-up roller for feeding out the paper;
A feed roller that rotates about a rotation axis and conveys the fed paper along a conveyance path;
A paper feed holder that supports the pickup roller and the feed roller;
A support frame having an accommodation recess that is removably supported along a direction intersecting the axial direction of the rotation shaft,
A drive input shaft that is pivotally supported by the support frame on the one axial side of the housing recess, is coupled to the rotation shaft, and transmits a driving force to the rotation shaft;
With
The receiving recess is
Provided along a wear de direction of the sheet paper holder, a pair of side wall portions opposed to each other in the axial direction,
A guide portion provided along the attachment / detachment direction on the pair of side wall portions to guide the paper feed holder in a slidable manner;
A positioning portion that is provided on the pair of side wall portions and that guides the paper feed holder guided along the guide portion at a predetermined position in which the drive input shaft and the rotation shaft are arranged coaxially;
Provided on the side wall portion on the other side in the axial direction, and with the slide of the paper feed holder to the predetermined position along the guide portion, the paper feed holder is pressed toward the one side in the axial direction to And a pressing portion for connecting a rotating shaft to the drive input shaft. One end portion of the rotating shaft and one end portion of the drive input shaft are engaged with each other to respectively engage and engage the engaging portion and the engaged portion that connect the rotating shaft and the drive input shaft so as to be integrally rotatable. Have
A holder urging member that urges the paper feed holder to the one side in the axial direction at the predetermined position and presses the engaging portion against the engaged portion;
When the drive input shaft rotates and the phase of the engaging portion and the phase of the engaged portion coincide with each other, the engaging portion and the engaged portion engage with each other, and the rotary shaft and the drive The paper feeding device according to claim 1, wherein the paper feeding device is connected to an input shaft. The paper feed holder is
A cylindrical first shaft portion and a cylindrical second shaft portion that respectively support both ends of the rotation shaft on the pair of side wall portions;
The positioning portion has a first bearing portion that supports the first shaft portion,
A proximal end portion of the first shaft portion is provided with a small-diameter portion having a smaller outer diameter than the outer diameter of the first shaft portion by cutting a part along the circumferential direction.
The first bearing portion is provided with a notch along the direction intersecting the axial direction through which the small diameter portion can pass.
When the paper feed holder is slid along the guide portion, the small diameter portion enters the first bearing portion from the notch, and the outer peripheral surface of the small diameter portion contacts the inner peripheral surface of the first bearing portion. The sheet feeding device according to claim 1, wherein the sheet feeding holder is positioned at the predetermined position by regulating a slide of the sheet feeding holder.   An image forming apparatus comprising the sheet feeding device according to claim 1. An opening / closing unit that is provided so as to be rotatable about a lower end portion, and that opens or forms a conveyance path downstream of the feed roller in the sheet conveyance direction;
The opening / closing unit is provided with a restricting portion for preventing the sheet feeding holder from moving to the other side in the axial direction when the opening / closing unit is rotated to form the transport path. 5. The image forming apparatus according to 4. The restricting portion is a rib that enters between the side wall portion on the other axial side of the housing recess and the paper feed holder, and the paper feed holder comes into contact with the rib so that the paper feed holder The image forming apparatus according to claim 5 , wherein movement to the other side in the axial direction is prevented.   A notch is formed at a lower edge of the opening / closing unit at a position corresponding to the paper feed holder. When the opening / closing unit is rotated so as to open the conveyance path, the feeding is performed through the notch. The image forming apparatus according to claim 5, wherein the paper holder is detachable.

Images