JP2016155670A - Conveyance device and image formation apparatus including the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a conveyance device and the like which achieve miniaturization, prevent falling of a multi-feeding prevention part, and improve the replace workability of the multi-feeding prevention part.SOLUTION: A conveyance device 5 comprises: a multi-feeding prevention part 42 which cooperates with a sheet feeding roller 41 to convey sheets S one by one; and a guide part 43 which includes a storage part 45 recessedly provided on a guide surface 44 of the sheet S. The multi-feeding prevention part 42 includes: a holder 61 which is detachably stored in the storage part 45; and a separation member 71 which is supported by the holder 61. The holder 61 includes: a holder body 62 having a displacement part 65b formed elastically deformable to the position apart to the downstream side in the conveyance direction of the sheet S from the support position of the separation member 71; an engagement boss 63 which is connected to a side wall 45a of the storage part 45; and an operation part 64 which extends toward the downstream side from the displacement part 65b. With elastic deformation of the displacement part 65b to the separation member 71 side via the operation part 64, connection between the side wall 45a and the engagement boss 63 is released.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a conveyance device suitably used for a copying machine, a printer, and the like, and an image forming apparatus including the same.

  An image forming apparatus such as a copying machine or a printer performs an image forming process on a sheet conveyed along a conveyance path. A conveyance device for conveying sheets includes a multifeed prevention unit that prevents conveyance (multifeed) of a plurality of overlapping sheets.

  For example, the conveyance device described in Patent Literature 1 includes a conveyance unit (paper feed roller) that conveys a sheet, and a multifeed prevention unit that is accommodated in a concave portion of a guide surface that guides the sheet. The double feed preventing portion includes a drag portion (retard roller) supported by the support portion of the holder, a filling member that holds the holder in the recess, and a guide plate that constitutes a part of the guide surface. . The holder has a connection piece disposed between the side wall of the recess and the support portion. The connection piece is provided with a connection portion (boss) connected to the hole in the side wall. When the connection piece is elastically deformed toward the support portion, the connection between the hole portion of the side wall and the connection portion is released. In this state, the double feed prevention unit that has consumed the drag unit is replaced. On the other hand, in a state where the hole portion of the side wall and the connection portion are connected, the filling member suppresses the elastic deformation of the connection piece by filling the space between the connection piece and the support portion.

JP 2011-190077 A

  However, the above-described transport device needs to set a wide interval between the side wall and the support portion according to the displacement amount of the connection piece. For this reason, it has been difficult to reduce the size of the transfer device described above.

  Moreover, since the space | interval of a side wall and a support part is wide, there existed a possibility that a holder might fall out from a recessed part. In order to prevent the holder from falling off, the transport device described above has to fill the gap between the connecting piece and the support portion with a filling member that is a separate member. For this reason, there existed a problem of the increase in the cost concerning manufacture and attachment work of a filling member.

  In addition, when replacing the double feed prevention part (holder and drag part), after removing the filling member, it was necessary to operate the connecting piece to remove the holder and to remove the guide plate. For this reason, the above-described transport device has a problem that the replacement work of the double feed prevention unit cannot be easily performed.

  In order to solve the above-described problems, the present invention includes a transport device that reduces the size and prevents the double feed prevention unit from falling off, and additionally improves the exchange workability of the double feed prevention unit. An object is to provide an image forming apparatus.

  In order to achieve the above-described object, the conveying device of the present invention includes a sheet feeding unit that conveys sheets one by one in cooperation with a sheet feeding member and a multifeed preventing unit, and the sheet conveyed by the sheet feeding unit. And a guide portion including a receiving portion recessed in a guide surface for guiding, the double feed preventing portion is detachably received in the receiving portion, and is supported by and overlapped with the holder. A separation member that separates a sheet, and the holder includes a holder main body in which a displacement portion that is elastically deformable is formed at a position away from a support position of the separation member on the downstream side in the sheet conveyance direction; An engaging portion provided in the displacement portion and rotatably connected to the side wall of the storage portion; and an operation portion extending from the displacement portion toward the downstream side in the sheet conveyance direction, The displacement part is moved through the operation part. By being elastically deformed toward the member, connection between the said side wall engaging portion is released.

  According to this configuration, the holder main body (displacement portion) can be provided at a position close to (or in contact with) the side wall of the housing portion. Therefore, since the gap between the side wall of the housing portion and the holder main body (displacement portion) is minimized, the transport device can be reduced in size. Moreover, since the space | interval of a side wall and a holder main body is narrow, the drop-off | omission of the holder from an accommodating part can also be suppressed. Moreover, according to this structure, a displacement part rotates elastically by using the periphery of the support position of a separation member as a fulcrum. Since the engaging portion is provided at a position away from the support position on the downstream side in the sheet conveying direction, the engaging portion is largely displaced by the elastic deformation of the displacement portion. Thereby, since the displacement amount of an engaging part can be ensured largely, the connection cancellation | release of an engaging part and a side wall can be performed appropriately. Furthermore, since the operation unit is provided at a position away from the displacement unit on the downstream side in the sheet conveyance direction, the displacement unit (engagement unit) can be greatly elastically deformed with a light force by the lever principle. As a result, the operator can easily replace the double feed prevention unit in which the separating member is consumed.

  In this case, the guide unit is detachably provided to the first guide unit so as to cover a part of the first guide unit having the storage unit and the storage unit, and is attached to the first guide unit. A second guide portion that forms the guide surface together with the first guide portion, and the second guide portion is fitted in the holder while being attached to the first guide portion. And it is preferable to restrict the elastic deformation of the displacement part.

  According to this configuration, the second guide portion is mounted on the first guide portion, thereby constituting a part of the guide surface and restricting elastic deformation of the displacement portion. That is, the 2nd guide part which comprises a guide surface is combined as a member which controls the displacement of a displacement part. Thereby, for example, a dedicated member that regulates the displacement of the displacement portion can be omitted, so that the cost for manufacturing and assembling the transfer device can be reduced. On the other hand, when the second guide part is removed from the first guide part, the displacement part can be elastically deformed. That is, it is possible to perform the replacement work of the double feed prevention unit simply by removing the second guide unit.

  In this case, the storage unit has a pair of side walls arranged so as to sandwich the holder, and the holder body has a pair of support plates that sandwich and support the separation member, and the pair of support members Each of the plates has the displacement portion, and the pair of displacement portions displaces the pair of operation portions in directions approaching each other, thereby releasing the connection between the side walls and the engagement portions. It is preferable that the second guide portion is interposed between the pair of support plates on the downstream side in the sheet conveyance direction with respect to the separation member and restricts elastic deformation of the pair of displacement portions.

  According to this structure, the operator can cancel | release the connection of each side wall and each engaging part by picking up a pair of operation part. Thereby, the operator can replace | exchange the multifeed prevention part easily and rapidly. In addition, since the second guide portion is provided on the downstream side in the sheet conveyance direction in which the displacement portion is largely displaced, the elastic deformation of the displacement portion can be effectively restricted.

  In this case, the first guide portion has a pair of slide locking portions provided with the accommodating portion interposed therebetween, and the second guide portion slides on the pair of slide locking portions of the first guide portion. It is preferable to have a pair of slide locked portions that engage with each other.

  According to this structure, the 2nd guide part is mounted | worn in the state which can slide to the 1st guide part (accommodating part). Thereby, since the attaching / detaching operation of the second guide portion can be easily performed, the operator can easily and quickly replace the double feed preventing portion.

  In order to achieve the above object, an image forming apparatus of the present invention includes any of the above-described transport apparatuses.

  According to this configuration, it is possible to use a downsized transport device, and thus it is possible to reduce the size of the image forming apparatus. In addition, the double feed prevention unit (holder) of the transport device includes a structure that suppresses dropping from the storage unit and a structure that allows the double feed prevention unit to be easily replaced. Thereby, usability concerning maintenance can be improved.

  According to the present invention, it is possible to reduce the size, to prevent the double feed prevention unit from falling off, and to improve the replacement workability of the double feed prevention unit.

1 is a side view schematically showing an internal structure of a color printer according to an embodiment of the present invention. It is a perspective view which shows the conveyance structure which concerns on one Embodiment of this invention. It is a perspective view which shows a part of conveying apparatus which concerns on one Embodiment of this invention. It is a perspective view which shows the guide part which concerns on one Embodiment of this invention. It is a perspective view which shows the 1st guide part which concerns on one Embodiment of this invention. It is a perspective view which shows the 2nd guide part which concerns on one Embodiment of this invention. It is a perspective view which shows the double feed prevention part which concerns on one Embodiment of this invention. It is a perspective view which shows the 1st guide part and double feed prevention part which concern on one Embodiment of this invention.

  Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings. Hereinafter, for convenience of explanation, explanation will be made with reference to the directions shown in the drawings. The terms “upstream” and “downstream” and similar terms refer to “upstream” and “downstream” in the conveying direction of the sheet S and similar concepts.

  With reference to FIG. 1, an overall configuration of a color printer 1 as an image forming apparatus will be described. FIG. 1 is a side view schematically showing the internal structure of the color printer 1.

  The color printer 1 includes an apparatus main body 2, a paper feed cassette 3, and a paper discharge tray 4. The apparatus main body 2 is formed in a substantially rectangular box shape. The paper feed cassette 3 is provided in the lower part of the apparatus main body 2. The paper discharge tray 4 is provided in the upper part of the apparatus main body 2.

  Further, the color printer 1 includes a conveyance device 5, an image forming unit 6, and a fixing device 7 inside the apparatus main body 2. The transport device 5 is provided on the upstream side of the transport path 8 extending from the paper feed cassette 3 to the paper discharge tray 4. The image forming unit 6 is provided in an intermediate part of the conveyance path 8. The fixing device 7 is provided on the downstream side of the conveyance path 8.

  The transport device 5 sends out the sheet S in the paper feed cassette 3 toward the transport path 8. Although the details will be described later, the transport device 5 constitutes a transport structure 30 together with the paper feed cassette 3. The sheet S is not limited to a paper sheet, and includes a sheet material such as a resin film or an OHP (Over Head Projector) sheet.

  The image forming unit 6 includes four toner containers 10, an intermediate transfer belt 11, four drum units 12, and an optical scanning device 13. The four toner containers 10 are juxtaposed in the left-right direction below the paper discharge tray 4. The intermediate transfer belt 11 is disposed below each toner container 10. The four drum units 12 are juxtaposed in the left-right direction below the intermediate transfer belt 11. The optical scanning device 13 is disposed below each drum unit 12.

  The four toner containers 10 contain toners (developers) of four colors (yellow, magenta, cyan, black). The toner may be a one-component developer made of a magnetic toner or a two-component developer containing a toner and a carrier. The intermediate transfer belt 11 is driven to run in the direction of the white arrow in FIG.

  The four drum units 12 are provided corresponding to the toners of the respective colors. Each drum unit 12 includes a photosensitive drum 20, a charging device 21, a developing device 22, a primary transfer roller 23, a cleaning device 24, and a charge removal device 25. Since the four drum units 12 have the same configuration, only one drum unit 12 will be described below.

  The photosensitive drum 20 is formed in a cylindrical shape that is long in the front-rear direction (the depth direction in FIG. 1). The photosensitive drum 20 is pivotally supported by the apparatus main body 2. The photosensitive drum 20 is in contact with the lower surface of the intermediate transfer belt 11. The charging device 21, the developing device 22, the primary transfer roller 23, the cleaning device 24 and the charge eliminating device 25 are arranged around the photosensitive drum 20 in the order of the transfer process. The primary transfer roller 23 is disposed to face the photosensitive drum 20 from above with the intermediate transfer belt 11 interposed therebetween. A secondary transfer roller 26 is disposed on the right side of the intermediate transfer belt 11 to form a secondary transfer nip portion 26a.

  Here, the operation of the color printer 1 will be described. A control device (not shown) of the color printer 1 executes an image forming process as follows based on the input image data.

  Each charging device 21 charges the surface of the photosensitive drum 20. The optical scanning device 13 performs exposure corresponding to the image data (see broken line arrows in FIG. 1) toward each photosensitive drum 20. Each developing device 22 develops the electrostatic latent image formed on the surface of each photosensitive drum 20 into a toner image. The four toner images carried on each photoconductor drum 20 are primary-transferred sequentially to the traveling intermediate transfer belt 11 by a primary transfer roller 23 to which a primary transfer bias is applied. As a result, a full-color toner image is formed on the surface of the intermediate transfer belt 11.

  On the other hand, the sheet S supplied from the paper feed cassette 3 is transported through the transport path 8 and passes through the secondary transfer nip portion 26a. The full-color toner image is secondarily transferred to the sheet S by the secondary transfer roller 26 to which a secondary transfer bias is applied. The fixing device 7 fixes a full-color toner image on the sheet S. The sheet S after the fixing process is discharged to the paper discharge tray 4. The cleaning device 24 removes the toner remaining on the surface of the photosensitive drum 20 after the transfer. The static eliminator 25 irradiates the static elimination light and removes the charge on the photosensitive drum 20.

  Next, the conveyance structure 30 of the sheet S will be described with reference to FIGS. FIG. 2 is a perspective view showing the transport structure 30. FIG. 3 is a perspective view showing a part of the transport device 5. FIG. 4 is a perspective view showing the guide portion 43. FIG. 5 is a perspective view showing the first guide portion 46. FIG. 6 is a perspective view showing the second guide portion 47. FIG. 7 is a perspective view showing the double feed preventing portion 42. FIG. 8 is a perspective view showing the first guide portion 46 and the double feed prevention portion 42.

  As shown in FIGS. 1 and 2, the transport structure 30 includes a paper feed cassette 3 and a transport device 5. The sheet feed cassette 3 accommodates a single sheet S therein. The transport device 5 sends out the single sheet S accommodated in the paper feed cassette 3 toward the transport path 8.

  The paper feed cassette 3 is configured to be insertable into the apparatus main body 2 through an opening 2 a formed at the lower left side of the apparatus main body 2. In addition, the paper feed cassette 3 is configured to be pulled leftward from the apparatus main body 2 in order to replenish sheets S.

  The paper feed cassette 3 includes a cassette body 31 and a design surface portion 32. The cassette body 31 is formed in a substantially rectangular box shape for stacking and accommodating sheets S. The design surface portion 32 is provided at the left end portion of the cassette body 31. The design surface portion 32 constitutes a part of the exterior surface of the apparatus main body 2 in a state where the paper feed cassette 3 is mounted on the apparatus main body 2.

  The paper feed cassette 3 has a lift plate 33, a pair of front and rear first cursors 34, and a second cursor (not shown) inside the cassette body 31.

  The lift plate 33 is disposed on the right side of the bottom plate 31 a of the cassette body 31. A pair of front and rear plate rotation shafts 33 a is provided at the left end portion of the lift plate 33. The pair of front and rear plate rotation shafts 33 a are pivotally supported by the pair of front and rear side plates 31 b of the cassette body 31. A push-up spring 35 is provided between the right side of the lift plate 33 and the bottom plate 31a. The lift plate 33 is pushed up by the urging force of the push-up spring 35 and pivots upward about each plate pivot shaft 33a (see FIG. 1). Although the detailed description is omitted, the lift plate 33 is pressed downward by the pressurizing device and rotates downward against the urging force of the push-up spring 35.

  As shown in FIG. 2, the pair of front and rear first cursors 34 is provided on the bottom plate 31 a so as to face each other with the lift plate 33 interposed therebetween. The pair of front and rear first cursors 34 is connected to an interlocking mechanism (not shown) such as a rack and pinion. The pair of front and rear first cursors 34 are slid symmetrically by the interlocking mechanism to align the front and rear widths of the sheets S (bundle) placed on the lift plate 33. The second cursor is provided on the bottom plate 31a so as to slide in the left-right direction, and aligns the left-right width of the sheet S (bundle).

  Next, as shown in FIG. 1, the transport device 5 is provided on the right side of the paper feed cassette 3 attached to the device main body 2. The transport device 5 includes a pickup roller 40, a paper feed roller 41, a double feed prevention unit 42, and a guide unit 43. The pickup roller 40 is provided above the right end portion of the lift plate 33. The paper feed roller 41 is provided on the right side of the pickup roller 40. The double feed prevention unit 42 is provided facing the lower side of the paper feed roller 41. The guide part 43 constitutes an upstream end part of the transport path 8. Note that the paper feed roller 41 and the double feed prevention unit 42 cooperate to constitute a paper feed unit that transports the sheets S one by one.

  The pickup roller 40 and the paper feed roller 41 are each pivotally supported by the apparatus main body 2 and are rotationally driven by a driving device (not shown). The pickup roller 40 sends out the pushed sheet S on the lift plate 33 toward the conveyance path 8. A sheet feeding roller 41 as a sheet feeding member conveys the sheet S toward the downstream side of the conveyance path 8. The double feed preventing portion 42 is supported by the guide portion 43 so as to be rotatable (swingable). Next, the guide part 43 that supports the double feed prevention part 42 will be described.

  As shown in FIG. 2, the guide part 43 is formed in the substantially trapezoid column shape long in the front-back direction, for example with a synthetic resin material. The front-rear width of the guide portion 43 is formed to be substantially the same front-rear width as that of the paper feed cassette 3. A guide surface 44 that guides the sheet S conveyed by the paper feed roller 41 and the double feed prevention unit 42 is formed on the upper surface of the guide unit 43. The guide surface 44 constitutes a surface that curves so as to have an upward slope from the upstream (left side) to the downstream (right side). A receiving portion 45 is recessed in the center in the front-rear direction of the guide surface 44 (see FIG. 5).

  As shown in FIGS. 2 and 3, the guide portion 43 includes a first guide portion 46 and a second guide portion 47. The first guide part 46 has a housing part 45. The 2nd guide part 47 is provided in the 1st guide part 46 so that attachment or detachment is possible so that a part of accommodating part 45 may be covered.

  A pair of first guide surfaces 50 are formed on the surface (upper surface and left surface) of the first guide portion 46 so as to be separated in the front-rear direction across the housing portion 45. The pair of front and rear first guide surfaces 50 constitute most of the guide surface 44. On the first guide surface 50, a plurality of transport ribs 50a are projected. The plurality of conveyance ribs 50a are arranged in parallel in the front-rear direction at a predetermined interval in order to facilitate the conveyance of the sheet S.

  As shown in FIGS. 4 and 5, a plurality of first support ribs 51 protrude from the back surfaces (lower surface and right surface) of the pair of front and rear first guide surfaces 50. The plurality of first support ribs 51 are arranged in parallel in the front-rear direction at a predetermined interval.

  As shown in FIG. 5, the accommodating portion 45 is formed between a pair of side walls 45 a extending downward from each first guide surface 50. The pair of front and rear side walls 45a are connected to the upstream half of each first guide surface 50, respectively. The pair of front and rear side walls 45a are disposed so as to face each other so as to sandwich a holder 61 (described later) of the double feed preventing portion 42. A circular engagement hole 48 is recessed in each of the pair of front and rear side walls 45a. A pair of front and rear engagement holes 48 are formed on the first guide surface 50 side at the left and right intermediate portions of the side walls 45a.

  In addition, the first guide portion 46 has a pair of front and rear slide locking portions 52 provided with the accommodating portion 45 interposed therebetween. The pair of front and rear slide locking portions 52 are extended upward along the first guide surfaces 50 from the upper part of the downstream end of the side wall 45a. Each slide locking portion 52 extends to about half the distance from the upper end portion of the side wall 45a to the upper end portion of the first guide surface 50.

  As shown in FIGS. 4 and 5, a pedestal portion 53 is provided below the first guide portion 46 so as to bulge out toward the accommodating portion 45. The pedestal portion 53 is provided near the front side wall 45 a of the housing portion 45. The pedestal portion 53 has an inclined surface 53a that is an upward gradient from upstream to downstream. A fitting projection 53b into which one end of the coil spring 60 is fitted projects from the inclined surface 53a.

  As shown in FIG. 3, the second guide portion 47 includes a guide main body portion 54 and an engagement piece 55. The guide body portion 54 is provided in the housing portion 45 so as to connect the pair of front and rear first guide surfaces 50. The engagement piece 55 is formed integrally with the guide main body 54.

  The guide main body 54 is provided so as to close the downstream half of the accommodating portion 45. A second guide surface 56 constituting a part of the guide surface 44 is formed on the surface (left surface) of the guide main body 54. That is, the second guide portion 47 is mounted on the first guide portion 46 to form a guide surface 44 together with the first guide portion 46.

  As shown in FIGS. 4 and 6, a bulging portion 57 bulging toward the right side is formed on the back side (right side) of the second guide surface 56. The bulging portion 57 is formed in a substantially box shape and extends below the second guide surface 56. The front-rear width of the bulging portion 57 is formed narrower (shorter) than the front-rear width of the second guide surface 56. A plurality of second support ribs 57 a protrude from the back surface of the bulging portion 57. The plurality of second support ribs 57a are arranged in parallel in the front-rear direction at a predetermined interval. At the lower end of the bulging portion 57, a hook portion 57b that is elastically deformed in the left-right direction is formed. The distal end portion of the hook portion 57b is locked in a hook hole (not shown) formed in the apparatus main body 2 (sheet metal frame) while being attached to the first guide portion 46.

  As shown in FIG. 6, a pair of front and rear slide grooves 58 (slide engaged portions) are formed at both front and rear end portions of the back surface of the guide main body portion 54. Each slide groove 58 is formed so as to connect the lower back side of the guide main body portion 54 to the side surface of the bulging portion 57. Each slide groove 58 is formed in a substantially L shape when viewed from the front, with the lower surface and the outer end surface in the front-rear direction opened. In the pair of front and rear slide grooves 58, a pair of front and rear slide locking portions 52 of the first guide portion 46 are formed to be slidable. Accordingly, the second guide portion 47 is supported so as to be slidable in the vertical direction with respect to the first guide portion 46 in a state where a part of the housing portion 45 is covered.

  As shown in FIG. 3, the engagement piece 55 extends from the lower end of the guide main body 54 in the lower left direction (upstream side). The front-rear width of the engagement piece 55 is formed narrower (shorter) than the front-rear width of the guide main body 54. Specifically, the engagement piece 55 is formed so as to fit inside a holder 61 described later. Further, the engagement piece 55 is formed so as to slightly protrude from the surface of the second guide surface 56 in the upper left direction. The engaging piece 55 is provided so as to have the same height as each of the conveying ribs 50a of the first guide surface 50.

  As shown in FIG. 3, the double feed preventing portion 42 includes a holder 61 and a separating member 71. The holder 61 is detachably accommodated in the accommodating portion 45. The separation member 71 is supported by the holder 61. The double feed prevention unit 42 is configured to prevent double feed of the conveyed sheet S.

  As shown in FIGS. 7 and 8, the holder 61 includes a holder main body 62, a pair of front and rear engagement bosses 63, and a pair of front and rear operation portions 64.

  As shown in FIG. 7, the holder main body 62 includes a pair of front and rear support plates 65 and a bottom plate 66. The pair of front and rear support plates 65 are erected along the pair of front and rear side walls 45 a of the housing portion 45. The bottom plate 66 is connected between a pair of front and rear support plates 65.

  As shown in FIG. 3 and FIG. 7, the pair of front and rear support plates 65 includes a fixed portion 65a and a displacement portion 65b, respectively. Each displacement part 65b is integrally formed in the downstream (right side) of each fixing | fixed part 65a.

  As shown in FIG. 7, a D-shaped fixing hole 67 penetrating in the front-rear direction is formed on the upstream side (left side) of each fixing portion 65a. Although the details will be described later, the pair of front and rear support plates 65 (fixed portions 65a) sandwich and support the separation member 71.

  Each displacement portion 65b extends from each fixed portion 65a toward the downstream side (right side). Each displacement part 65b is formed in the position away from the fixed hole 67 used as the support position of the separation member 71 in the downstream. Each displacement portion 65b is formed to be elastically deformed in the front-rear direction. Specifically, each displacement portion 65b is elastically rotated in the front-rear direction with the periphery of the fixing hole 67 (or the connecting portion with the fixing portion 65a) as a fulcrum.

  The bottom plate 66 connects the lower portions of a pair of fixing portions 65a that are separated in the front-rear direction. The bottom plate 66 is curved downward so as to cover the lower surface of the separation member 71 supported by the pair of front and rear support plates 65 (fixed portions 65a). A fitting projection 66 a is provided on the bottom plate 66 so as to face the pedestal 53 of the first guide portion 46. The other end of the coil spring 60 is fitted to the fitting protrusion 66a. The coil spring 60 is installed between the holder 61 and the first guide portion 46 (see FIG. 8).

  A pair of front and rear engaging bosses 63 as the engaging portions are respectively provided on the displacement portion 65b. Each engagement boss 63 is formed in a cylindrical shape. Each engagement boss 63 protrudes outward from the front-rear direction outer side surface of each displacement portion 65b. The pair of front and rear engagement bosses 63 are inserted into the engagement holes 48 opened in the pair of front and rear side walls 45a in a state where the holder 61 is housed in the housing portion 45 (see FIGS. 3 and 8). Thereby, each engagement boss | hub 63 is connected to each side wall 45a of the accommodating part 45 so that rotation (fluctuation) is possible.

  As shown in FIGS. 3 and 8, the front-rear width of the holder main body 62 (the arrangement distance of the pair of front and rear support plates 65) is slightly narrower (shorter) than the front-rear width of the housing portion 45. That is, the holder main body 62 (each displacement portion 65b) can be provided at a position close to (or slightly abutted against) each side wall 45a of the housing portion 45. Therefore, since the gap between each side wall 45a of the accommodating portion 45 and the holder main body 62 (displacement portion 65b) is minimized, the transport device 5 can be reduced in size. Moreover, since the space | interval of each side wall 45a and the holder main body 62 is narrow, the drop-off of the holder 61 from the accommodating part 45 can also be suppressed. For example, each engagement boss 63 is supported in each engagement hole 48 so as not to drop off even when the holder 61 moves in either one of the front and rear directions within the accommodating portion 45.

  As shown in FIGS. 7 and 8, the pair of front and rear operation sections 64 are extended from the displacement section 65b toward the downstream side. Specifically, the pair of front and rear operation portions 64 has a shape in which the distal end portions extending so as to approach each other from the downstream end portion of the displacement portion 65b are bent at a right angle. That is, the pair of front and rear operation portions 64 are formed in a substantially L shape that is front-rear symmetrical in a side view.

  The separating member 71 includes a retard roller 72 and a torque limiter 73. The separating member 71 is provided to separate the overlapping sheets S.

  The retard roller 72 is formed in a cylindrical shape and is rotatably supported on the peripheral surface of the torque limiter 73. The retard roller 72 is supported on the front side of the torque limiter 73. The torque limiter 73 is provided to control the rotation of the retard roller 72. At both front and rear ends of the torque limiter 73, a pair of front and rear fixed shafts 73a having a substantially D-shaped cross section are projected (see FIG. 7). Each fixed shaft 73a is fitted and fixed in a pair of front and rear fixing holes 67 formed in the holder 61. Thereby, the torque limiter 73 is supported so as not to rotate with respect to the holder 61.

  The holder 61 is biased by the coil spring 60 and pivots upward about the pair of front and rear engagement bosses 63 connected to the pair of front and rear engagement holes 48. As a result, the retard roller 72 is pressed against the paper feed roller 41 and forms a transport nip N between the retard roller 72 and the paper feed roller 41 (see FIG. 1).

  Next, the operation of the transport structure 30 will be described. As shown in FIG. 1, the bundle of sheets S placed on the lift plate 33 is urged and pushed up by the push-up spring 35. The pickup roller 40 contacts the uppermost surface of the bundle of sheets S and sends the sheet S toward the conveyance nip N.

  Here, when one sheet S is sent to the conveyance nip N, the retard roller 72 receives a large torque (torque exceeding the limitable range of the torque limiter 73) from the sheet feeding roller 41 with the sheet S interposed therebetween. Followed rotation. Accordingly, the sheet S is conveyed along the guide surface 44 and sent out to the conveyance path 8. On the other hand, when two sheets S are sent to the conveyance nip N, the torque transmitted from the paper feed roller 41 to the retard roller 72 is weakened. For this reason, the torque limiter 73 operates and the retard roller 72 does not rotate. As a result, the retard roller 72 applies a frictional force to the sheets S other than the sheet S that is in direct contact with the paper feed roller 41. As a result, the paper feed roller 41 sends out only the sheet S that is in direct contact to the transport path 8.

  As described above, since the retard roller 72 prevents the sheet S from being double fed by the frictional force, it wears over time. Therefore, the transport device 5 according to the present embodiment is configured so that the double feed prevention unit 42 including the worn retard roller 72 can be easily replaced.

  Next, a case where the double feed prevention unit 42 is replaced will be described. In the following description, it is assumed that the cover (not shown) of the apparatus main body 2 is opened and the worker can work on the transport device 5.

  First, the operator removes the second guide portion 47 from the first guide portion 46. Specifically, the operator releases the connection between the hook portion 57b of the second guide portion 47 and the hook hole of the sheet metal frame (see FIG. 4). Then, the operator slides the second guide part 47 upward with respect to the first guide part 46. Thereby, each slide groove 58 of the 2nd guide part 47 detaches | leaves from each slide latching | locking part 52 of the 1st guide part 46, and the 2nd guide part 47 is removed (refer FIG. 8).

  Subsequently, the operator grasps the pair of front and rear operation units 64 and displaces the pair of front and rear operation units 64 in a direction approaching each other (front-rear direction). The pair of front and rear displacement portions 65b are also integrated with each operation portion 64 and displaced so as to approach each other. Thereby, the pair of front and rear engagement bosses 63 are detached from the respective engagement holes 48 of the housing portion 45. The operator pulls the double feed preventing portion 42 disposed in the housing portion 45 upward while maintaining the state in which the connection between each engagement boss 63 and each engagement hole 48 is released.

  As described above, the double feed preventing portion 42 is removed from the guide portion 43 (see FIG. 5). At this time, the coil spring 60 is also removed together with the double feed preventing portion 42 (holder 61).

  Next, the operator attaches a new double feed prevention unit 42 (including the retard roller 72 that is not worn) to the storage unit 45 by a procedure reverse to the above-described procedure (removal process). That is, the operator holds the pair of front and rear operation units 64 and displaces the pair of front and rear operation units 64 and the pair of front and rear displacement units 65b in a direction approaching each other. The operator accommodates the multifeed preventing portion 42 in the accommodating portion 45 in a state where the pair of front and rear operation portions 64 are picked. When the operator weakens the force to grip each operation portion 64, each displacement portion 65b returns to its original position by its own restoring force (elastic force), and each engagement boss 63 is fitted in each engagement hole 48. . Thereby, the double feed prevention part 42 (holder 61) is accommodated in the accommodating part 45 in a rotatable state (see FIG. 8).

  Subsequently, the worker attaches the second guide portion 47 to the first guide portion 46. Specifically, the operator aligns each slide groove 58 with each slide locking portion 52 and slides the second guide portion 47 downward with respect to the first guide portion 46. When the upper end surface of each slide locking portion 52 comes into contact with the upper end surface of each slide groove 58, the slide of the second guide portion 47 stops. At this time, the hook portion 57b of the second guide portion 47 is engaged with the hook hole of the sheet metal frame.

  Thus, the second guide portion 47 is attached to the first guide portion 46 (see FIG. 4). In this state, the engagement piece 55 of the second guide portion 47 enters between the pair of front and rear support plates 65 (displacement portions 65b) on the downstream side of the separation member 71 (see FIG. 3). Therefore, the engagement piece 55 acts to restrict elastic deformation of the pair of front and rear displacement portions 65b. The engagement piece 55 is disposed so as to face the pair of front and rear engagement bosses 63 with the displacement portions 65b interposed therebetween. Thereby, the elastic deformation of each displacement portion 65b is appropriately regulated, and each engagement boss 63 is effectively prevented from dropping from each engagement hole 48. Note that the distal end portion (left lower end portion) of the engagement piece 55 extends to the vicinity of the separation member 71.

  As described above, the pair of front and rear displacement portions 65b are elastically deformed toward the separating member 71 via the operation portions 64, whereby the connection between the side walls 45a and the engagement bosses 63 is released. . According to the transport device 5 according to the present embodiment, each engaging boss 63 is provided at a position away from the periphery of the fixing hole 67 (or the connecting portion with the fixing portion 65a) on the downstream side. Large displacement is caused by elastic deformation of the portion 65b. Thereby, since the displacement amount of each engagement boss | hub 63 can be ensured large, the connection cancellation | release with each engagement boss | hub 63 and each side wall 45a can be performed appropriately. Furthermore, since each operation part 64 is provided in the position away | separated from the displacement part 65b in the downstream, each displacement part 65b (each engagement boss | hub 63) can be largely elastically deformed with a light force by the lever principle. it can. As a result, the operator can easily replace the double feed prevention unit 42 in which the separating member 71 is consumed.

  As described above, the second guide portion 47 is fitted in the holder 61 while being attached to the first guide portion 46, and restricts elastic deformation of each displacement portion 65b. At the same time, the second guide portion 47 (second guide surface 56) constitutes a part of the guide surface 44 together with the first guide portion 46 (first guide surface 50). That is, the 2nd guide part 47 which comprises the guide surface 44 is shared as a member which controls the displacement of each displacement part 65b. Thereby, for example, a dedicated member that regulates the displacement of each displacement portion 65b can be omitted, so that the cost for manufacturing and assembling the transport device 5 can be reduced. On the other hand, when the second guide portion 47 is removed from the first guide portion 46, each displacement portion 65b can be elastically deformed. The second guide portion 47 is attached to the first guide portion 46 (accommodating portion 45) in a slidable state. Thereby, since the attachment / detachment work of the 2nd guide part 47 can be performed easily, the operator can replace the double feed prevention part 42 easily and rapidly.

  Moreover, according to the conveying apparatus 5 which concerns on this embodiment, the displacement part 65b is formed in the front-back pair support plate 65, respectively. The pair of front and rear displacement parts 65b are elastically deformed so as to release the connection between each side wall 45a and each engagement boss 63 by displacing the pair of front and rear operation parts 64 in a direction approaching each other. According to this configuration, the operator can release the connection between each side wall 45a (engagement hole 48) and each engagement boss by grasping the pair of front and rear operation portions 64. As a result, the operator can easily and quickly replace the double feed prevention unit 42. Moreover, since the 2nd guide part 47 is provided in the downstream from which each displacement part 65b is displaced greatly, the elastic deformation of each displacement part 65b can be controlled effectively.

  In addition, according to the color printer 1 according to the present embodiment, since the transport device 5 that is downsized can be used, the color printer 1 can be downsized. In addition, the double feed prevention unit 42 (holder 61) of the transport device 5 has a structure that suppresses dropping from the storage unit 45 and a structure that allows the double feed prevention unit 42 to be easily replaced. Thereby, usability concerning maintenance can be improved.

  In the transport device 5 according to the present embodiment, a pair of engagement bosses 63 are provided in the holder 61 of the double feed prevention unit 42, and a pair of engagement holes 48 are provided in each side wall 45a of the storage unit 45. The present invention is not limited to this. For example, a pair of engagement holes 48 may be provided in the holder 61, and a pair of engagement bosses 63 may be provided in each side wall 45a.

  In addition, although the conveying apparatus 5 which concerns on this embodiment provided the pair of displacement part 65b, this invention is not limited to this. For example, the displacement portion 65b may be provided only on one of the pair of front and rear support plates 65. In this case, either one of the pair of front and rear support plates 65 is configured not to be greatly displaced. The pair of front and rear engagement bosses 63 are provided on one displacement portion 65 b and the other support plate 65. In this modification, when exchanging (removing) the double feed preventing portion 42, the operator displaces one of the displacement portions 65 b to disengage the engagement boss 63 from the engagement hole 48. The operator then pulls out the engagement boss 63 provided on the other support plate 65 from the engagement hole 48 by pulling the double feed prevention portion 42 obliquely upward. As a result, the double feed prevention unit 42 is removed from the storage unit 45.

  In the above-described replacement operation of the double feed prevention unit 42, the entire double feed prevention unit 42 (the holder 61 and the separation member 71) is exchanged, but the present invention is not limited to this. For example, only the worn retard roller 72 (or the separating member 71 including this) may be replaced, and the holder 61 and the like may be reused.

  The description of the above embodiment shows one aspect of the transport device according to the present invention and an image forming apparatus including the same, and the technical scope of the present invention is not limited to the above embodiment. The components in the above embodiment can be appropriately replaced or combined with existing components and the like, and the description of the above embodiment does not limit the content of the invention described in the claims. .

1 Color printer (image forming device)
5 Transport device 41 Paper feed roller (paper feed member)
42 Double Feed Preventing Part 43 Guide Part 44 Guide Surface 45 Housing Part 45a Side Wall 46 First Guide Part 47 Second Guide Part 52 Slide Locking Part 58 Slide Groove (Slide Locked Part)
61 Holder 62 Holder body 63 Engagement boss (engagement part)
64 Operation part 65 Support plate 65b Displacement part 71 Separation member S sheet

Claims (5)

A sheet feeding unit that conveys the sheets one by one in cooperation with the sheet feeding member and the double feed prevention unit;
A guide portion including a receiving portion that is recessed in a guide surface that guides the sheet conveyed by the sheet feeding portion,
The multifeed prevention unit is
A holder detachably accommodated in the accommodating portion;
A separating member that is supported by the holder and separates the overlapped sheets,
The holder is
A holder body in which a displacement part that is elastically deformable is formed at a position away from the supporting position of the separating member on the downstream side in the sheet conveying direction;
An engaging portion provided at the displacement portion and rotatably connected to a side wall of the accommodating portion;
An operation portion extending from the displacement portion toward the downstream side in the conveyance direction of the sheet,
The transfer device is characterized in that the connection between the side wall and the engagement portion is released by elastically deforming the displacement portion toward the separating member via the operation portion. The guide part is
A first guide part having the housing part;
A second guide part that is detachably provided on the first guide part so as to cover a part of the housing part, and that forms the guide surface together with the first guide part by being attached to the first guide part; Have
2. The transport device according to claim 1, wherein the second guide portion is fitted in the holder while being attached to the first guide portion, and restricts elastic deformation of the displacement portion. . The accommodating portion has a pair of side walls disposed so as to sandwich the holder,
The holder body has a pair of support plates that sandwich and support the separation member,
Each of the pair of support plates has the displacement portion,
The pair of displacement portions are elastically deformed so as to release the connection between the side walls and the engagement portions by displacing the pair of operation portions in a direction approaching each other.
The said 2nd guide part enters between between a pair of said support plates in the conveyance direction downstream of the said sheet | seat rather than the said separation member, The elastic deformation of a pair of said displacement part is controlled. Transport device. The first guide portion has a pair of slide locking portions provided with the accommodating portion interposed therebetween,
The said 2nd guide part has a pair of slide latching | locking part slidably engaged with the said pair of slide latching | locking part of the said 1st guide part, The Claim 2 or 3 characterized by the above-mentioned. The conveying apparatus as described.   An image forming apparatus comprising the transport device according to claim 1.

Images