JP2020071452A - Drive transfer mechanism, sheet conveyance apparatus, and image forming apparatus - Google Patents

Abstract

To allow a unit to be easily attached or detached.SOLUTION: A driving unit (141) having a drive source and output gears (143, 144) connected to the drive source, and a driven unit having an input gear engaged with the output gear and driven by driving force of the drive source are mounted on a device body. The device body includes projections (156, 157) formed so that a downstream surface in a first direction is a convex (156a) protruding in the first direction and an upstream surface in the first direction is a concave (156b) recessed toward the first direction. The driving unit and the driven unit are fixed to the device body while a convex part formed in one of the driving unit and the driven unit is engaged with the concave and a concave part formed in the other of the driving unit and the driven unit is engaged with the convex.SELECTED DRAWING: Figure 6

Description

  The present invention relates to a drive transmission mechanism that transmits drive, a sheet conveying device that conveys a sheet, and an image forming apparatus that forms an image on a sheet.

  Image forming apparatuses such as printers, copiers, and multifunctional machines often have a unitized structure for each function of the apparatus in order to improve assembly and maintenance. Examples of such a unit include a conveyance unit that conveys a sheet, an image forming unit that forms an image on a sheet, and a drive unit that supplies a driving force to a driven unit such as a conveyance unit or an image forming unit. When connecting the drive unit and the driven unit, the positioning accuracy of the gear that transfers the driving force between the units is one of the factors that affect the drive transmission efficiency and the noise level.

  Patent Document 1 discloses a drive mechanism that transmits a driving force between a first gear provided in a device body having a drive source and a second gear provided in a paper feeding unit attached to the device body. Have been described. According to this document, a U-shaped groove-shaped cutout portion is provided in the paper feeding unit, and the cutout portion is fitted to the rotary shaft of the first gear when the paper feeding unit is attached to the apparatus main body. Then, the first gear and the second gear are positioned.

JP, 11-184196, A

  In addition to the driven unit being attachable / detachable to / from the apparatus main body like the paper feeding unit of the above document, it is considered that the drive unit having a drive source is also attachable / detachable to / from the apparatus main body in order to improve maintainability. Be done. However, as a result of the study conducted by the inventors, in the configuration in which the groove shape provided in one unit is directly engaged with the shaft member provided in the other unit like the cutout portion described in the above document, the unit is There was a case where the putting on and taking off was hindered. That is, when one unit is removed, the engagement of the shaft member with the groove shape is lost, and the other unit may be displaced from its original position due to gravity or the like. Sometimes the groove shape did not engage smoothly.

  Therefore, it is an object of the present invention to provide a drive transmission mechanism, a sheet conveying device, and an image forming apparatus in which the unit can be easily attached and detached.

  One aspect of the present invention includes a drive unit having a drive source and an output gear connected to the drive source, and an input gear engaging with the output gear, and the driven unit driven by the drive force of the drive source. A unit, an apparatus body to which the drive unit and the driven unit are attached, and a downstream surface in the first direction, which is provided in the apparatus body and has a convex shape protruding in the first direction, A protrusion formed so that an upstream surface of the drive unit has a concave shape that is recessed in the first direction; a protrusion provided on any one of the drive unit and the driven unit; A unit and a recess provided on the other side of the driven unit, wherein the protrusion engages with the recess of the protrusion, and the recess engages with the protrusion of the protrusion. In the state The drive unit and the driven unit is fixed relative to the apparatus main body, a drive transmission mechanism, characterized in that.

  According to the present invention, the unit can be easily attached and detached.

1 is a schematic diagram of an image forming apparatus according to an embodiment of the present disclosure. Sectional drawing of the manual feeding unit which concerns on this embodiment. FIG. 3 is a perspective view showing a manual feeding unit and a main body frame of the image forming apparatus according to the present embodiment. The perspective view (a) and side view (b) which show a part of manual feeding unit which concerns on this embodiment. The perspective view which shows the drive module which concerns on this embodiment. FIG. 6A is a perspective view showing a state in which a part of the frame is removed from FIG. The perspective view which shows the motor unit which concerns on this embodiment. The figure (a-c) for demonstrating the attachment method of the manual feeding unit which concerns on this embodiment. Drawing 8 (a-c) which expressed the same state as Drawing 8 (a)-(c) with another section. The figure (a-c) which represented the same state as FIG. 8 (a)-(c) by another cut surface. Sectional drawing which shows the mounting state (a) and removal state (b) of the motor unit which concerns on this embodiment. The perspective view which shows the drive module of a reference example.

  Hereinafter, exemplary embodiments for carrying out the present invention will be described with reference to the drawings.

  FIG. 1 is a schematic diagram of an image forming apparatus according to this embodiment. The image forming apparatus 1 according to the present embodiment is a multi-function peripheral including an electrophotographic image forming unit 1B inside the apparatus main body 1A. The image forming apparatus 1 forms an image on the sheet S based on image information input from an external PC or image information read from a document. However, sheets used as recording media or originals include paper such as paper and envelopes, surface-treated sheet materials such as coated paper, plastic films for overhead projectors, and cloth.

  The image forming unit 1B, which is an example of an image forming unit, includes four image forming units 10Y, 10M, 10C, and 10K that form toner images of yellow, magenta, cyan, and black, and an intermediate transfer belt 31. The tandem type intermediate transfer system is provided. The image forming units 10Y, 10M, 10C, and 10K are electrophotographic units each including a photosensitive drum 11 formed of a photoconductor and exposure devices 13Y, 13M, 13C, and 13K that irradiate the photosensitive drum 11 with laser light. is there. The configurations of the image forming units 10Y, 10M, 10C, and 10K are substantially the same except for the color of the toner used for development, and therefore the yellow image forming unit 10Y will be described below as an example.

  The image forming unit 10Y includes a charger 12, a developing device 14, and a cleaner 15 arranged around the photosensitive drum 11. When the image forming operation is started, the surface of the photosensitive drum 11 is uniformly charged by the charger 12 as the photosensitive drum 11 rotates. The exposure device 13Y scans the surface of the photosensitive drum 11 based on the image information, and forms an electrostatic latent image corresponding to a yellow color separation image. The developing device 14 supplies charged toner to the photosensitive drum 11 to visualize (develop) the electrostatic latent image as a toner image.

  The intermediate transfer belt 31, which is an intermediate transfer member, is made of an endless belt-shaped film and is stretched around a drive roller 33, a tension roller 34, and a secondary transfer inner roller 32. The intermediate transfer belt 31 is rotationally driven by the drive roller 33 in the direction along which the photosensitive drum 11 is rotated (arrow R1). On the inner peripheral side of the intermediate transfer belt 31, a primary transfer roller 35 is arranged at a position facing the photosensitive drum 11 of each image forming unit. The toner images formed in the image forming units 10Y, 10M, 10C, and 10K are primarily transferred to the intermediate transfer belt 31 so as to be superimposed on each other by applying a bias voltage to the primary transfer roller 35.

  Further, on the outer peripheral side of the intermediate transfer belt 31, a secondary transfer roller 41 facing the inner secondary transfer roller 32 across the intermediate transfer belt 31 is arranged. The secondary transfer roller 41 is an example of a transfer unit that transfers a toner image onto a sheet, and forms a secondary transfer portion as a nip portion between the intermediate transfer belt 31 and the secondary transfer roller 41. The full-color toner image carried on the intermediate transfer belt 31 is secondarily collectively transferred to the sheet S at the secondary transfer portion by applying a bias voltage to the secondary transfer roller 41.

  In parallel with such an image forming operation, a plurality of feeding cassettes 71 provided in the lower portion of the apparatus main body 1A, or a manual feeding portion 60 provided on a side portion of the apparatus main body 1A is directed to the image forming portion 1B. Sheet S is fed. The sheets S stored in the respective feeding cassettes 71 are separated and fed one by one by a feeding unit 70 including a pickup roller 72a, a feed roller 72b, and a retard roller 72c. The sheet S sent out from the feeding cassette 71 is conveyed to the registration roller pair 76 via the vertical path conveying roller pair 73 and the pre-registration conveying roller pair 74. It should be noted that the sheet sent out from the feeding cassette 71 on the upper left side of the drawing is conveyed via a part of the double-sided conveying path 85. On the other hand, the sheets S placed on the tray 110 of the manual feeding unit 60 are separated one by one by the feeding unit 65 including the pickup roller 65a, the feed roller 65b, and the retard roller 65c, and the registration roller pair 76 is separated. Be transported to.

  The registration roller pair 76 corrects the skew of the sheet S and conveys the sheet S toward the secondary transfer unit in accordance with the progress of the image forming operation by the image forming unit 1B. The sheet S to which the toner image has been transferred at the secondary transfer portion is conveyed to the fixing device 45 having a pair of rollers for nipping and conveying the sheet S and a heat source (not shown) via the pre-fixing conveyance portion 42. .. The fixing device 45 fixes the toner image on the sheet S by heating and pressing the sheet S. The sheet S that has passed through the fixing device 45 is conveyed toward the branch portion 82 by the pair of conveying rollers 46.

  In the case of single-sided printing, the sheet S is guided to the discharge roller pair 83 by a switching member (not shown) at the branch portion 82, and is discharged to the discharge tray 66 outside the apparatus by the discharge roller pair 83. In the case of double-sided printing, the sheet S that has passed through the fixing device 45 is guided to the reversal conveyance section at the branch section 82. The reversing conveyance unit has a plurality of pairs of rollers 91, 92, 93 capable of normal rotation and reverse rotation, and switches back the sheet S guided to the reversing path 84 to send it to the double-sided conveyance path 85. A plurality of pairs of rollers are arranged in the double-sided conveyance path 85, and the sheet S is conveyed toward the registration roller pair 76. Then, the sheet S on which the image is formed on the second surface by the same process as the above-described first surface is guided toward the discharge roller pair 83 at the branch portion 82 and discharged to the discharge tray 66.

(Manual feed section)
Next, the manual feeding unit 60, which is an example of the sheet conveying device, will be described. The manual feed unit 60 includes a manual feed unit 65 and a motor unit (described later) that drives the manual feed unit 65. The manual feeding unit 65 is arranged on the right side when the image forming apparatus 1 is viewed from the front (that is, the right side when viewed from the viewpoint of FIG. 1). Hereinafter, the left-right direction of the image forming apparatus 1 is the X-axis direction, the front-back direction of the image forming apparatus 1 is the Y-axis direction, and the vertical direction of the image forming apparatus 1 (the vertical direction when the apparatus is installed on a horizontal plane) is the Z-axis. Direction.

  FIG. 2 is a sectional view of the manual feeding unit 65 taken along the XZ plane. The feeding unit 65 includes the pickup roller 65a, the feed roller 65b, and the retard roller 65c described above. A pull-out roller pair 75 is arranged downstream of the feed roller 65b in the sheet feeding direction. The pickup roller 65a, the feed roller 65b, and the pull-out roller pair 75 are all examples of a sheet conveying unit that conveys a sheet by using a driving force of a driving source.

  The pickup roller 65a is supported by the pickup arm 121. The pickup arm 121 can swing up and down about a feed roller shaft that is a rotation shaft of the feed roller 65b. When a sheet is fed from the tray 110, each roller of the feeding unit 65 is driven to rotate, and the cam mechanism moves the pickup arm 121 downward from the position shown in FIG. 2 to bring the pickup roller 65a into contact with the sheet. The pickup operation is performed.

  The sheet fed out in the feeding direction by the pickup roller 65a is conveyed toward the pull-out roller pair 75 by the feed roller 65b. At this time, in the separation nip portion between the feed roller 65b and the retard roller 65c, the retard roller 65c applies a frictional force to the sheet to separate the sheet. That is, the retard roller 65c receives a driving force in the direction opposite to the feeding direction (clockwise direction in the drawing) via the torque limiter, and when a plurality of sheets enter the separation nip portion, a friction force is applied. Then, the sheets other than the topmost sheet are pushed back to the tray 110. When only one sheet enters the separation nip portion, the torque limiter slides and the retard roller 65c is rotated by the feed roller 65b. The pull-out roller pair 75 conveys the sheet received from the feed roller 65b to the registration roller pair 76 (FIG. 1). The retard roller 65c is an example of a separating member that separates sheets, and a roller member connected to a non-rotating shaft member via a torque limiter or a pad-like friction member may be used.

  The tray 110 is supported by the frame 130 of the manual feeding unit 65, and is rotatable between the posture opened from the right side surface of the image forming apparatus 1 and the posture closed along the right side surface. As shown in FIG. 3, the tray 110 is provided with side regulating plates 111 and 112 for regulating the sheet position to improve the stability of the feeding operation and the printing accuracy. After placing a desired sheet on the tray 110, the user regulates the sheet position by moving the side regulating plates 111 and 112 to bring them into contact with the end portions of the sheet. The image forming apparatus 1 is loaded on the tray 110 using a volume sensor or the like that outputs a signal according to the distance between the side regulation plates 111 and 112 (or based on information input by the user via the operation panel). Figure out the size of the sheet that you have. In the present embodiment, the manual feeding unit 65 can handle sheets of envelope size / postcard size to A3 size.

(Drive transmission mechanism)
Next, a drive transmission mechanism for transmitting the driving force to the manual feeding unit 65 will be described with reference to FIGS. FIG. 3 is a perspective view showing a state in which the manual feeding unit 65 is attached to the apparatus body of the image forming apparatus 1. 4A is a perspective view showing a portion (driving coupling portion) where the manual feeding unit 65 is coupled to the driving module of the image forming apparatus 1, and FIG. 4B is a side view of the driving coupling portion. .. FIG. 5 is a perspective view showing the drive module, and FIG. 6A is a perspective view showing the drive module with a part of the frame removed. FIG. 7 is a perspective view of a motor unit that drives the manual feeding unit 65.

  As shown in FIG. 3, the frame 130 of the manual feeding unit 65 is fixed to the main body frame 200, which is the frame body of the apparatus main body 1A, by fasteners such as screws. Of the frame 130, a front frame 131 located on one side in the Y-axis direction (front side of the image forming apparatus 1) is fixed to the right front frame 201 of the apparatus body 1A, and a rear frame 132 located on the other side in the Y-axis direction. Is fixed to the right rear frame 202 of the apparatus body 1A.

  The drive connecting portion for connecting the manual feed unit 65 and the drive module of the image forming apparatus 1 is located on the rear side of the manual feed unit 65 as shown in FIGS. 4A and 4B. That is, the feeding input gear 133 and the pulling-out input gear 134 of the manual feeding unit 65 are both held by the rear frame 132. The feed input gear 133 is a gear that meshes with a feed output gear 143 described below and rotates about a rotation axis (second axis) parallel to the rotation axis (first axis) of the feed output gear 143. is there. The pull-out input gear 134 is a gear that meshes with a pull-out output gear 144, which will be described later, and rotates about a rotation axis parallel to the rotation axis of the pull-out output gear 144.

  The feed input gear 133 is connected to a pickup roller 65a, a feed roller 65b, a retard roller 65c, and a cam mechanism that swings the pickup arm 121. The pull-out input gear 134 is connected to the pull-out roller pair 75. The feed input gear 133 and the pull-out input gear 134 of the present embodiment use gears of the same specifications (module 0.8, number of teeth 23, helical gear with left twist direction).

  A guide groove 135 is formed below the feed input gear 133 and the pull-out input gear 134 of the rear frame 132. The guide groove 135 has a groove shape that extends in the X-axis direction and has a rectangular cross-sectional shape that opens toward one side (rear side of the device) in the Y-axis direction. The guide groove 135 has a function of positioning the feed input gear 133 and the pull-out input gear 134 with respect to the corresponding output gear by engaging with a protrusion of the apparatus main body described later.

  As shown in FIG. 5, the drive module 140 that supplies a driving force to each part of the image forming apparatus 1 is arranged at the rear part of the image forming apparatus 1 and is assembled to the main body frame 200. As shown in FIG. 6A, the drive module 140 includes a front support plate 151 and a rear support plate 152 fixed to the main body frame 200, and a plurality of motor units supported by the front support plate 151 and the rear support plate 152. , 141, 241 and 341. That is, the front support plate 151 and the rear support plate 152 fixed to the main body frame 200 form a part of the apparatus main body 1A to which the drive unit can be attached / detached.

  Each of the motor units 141, 241 and 341 is an example of a driving unit that supplies a driving force to a driven unit such as the manual feeding unit 65. The motor unit 141 supplies a driving force to the manual feeding unit 65, rotates the pickup roller 65a, the feed roller 65b, and the retard roller 65c, and also rotates a cam for swinging the pickup arm 121. The other motor unit 241 rotates the pull-out roller pair 75 of the manual feeding unit 65. Still another motor unit 341 supplies driving force to the feeding unit 70 (FIG. 1) that feeds sheets from the feeding cassette 71.

  As shown in FIG. 7, the motor unit 141 that supplies a driving force to the manual feeding unit 65 includes a motor 142, a motor support plate 145, a feeding output shaft 146, a feeding output gear 143, and a timing belt 149. .. The motor 142, which is the drive source of this embodiment, is fixed to the motor support plate 145. The motor support plate 145 is fixed to the main body frame 200 by a method such as screwing to the rear support plate 152. The feed output shaft 146 is also fixed to the motor support plate 145 by a method such as caulking, and rotatably supports the feed output gear 143 which is an output member meshing with the feed input gear 133. The timing belt 149 connects the first pulley 142a attached to the motor output shaft and the second pulley 143a integrated with the feed output gear 143. Therefore, the rotation of the motor 142 is transmitted to the feeding output gear 143 via the timing belt 149.

  The motor unit 241 that supplies the driving force to the pull-out roller pair 75 of the manual feeding unit 65 also has the same configuration as the motor unit 141. That is, the motor unit 241 includes a motor, a motor support plate, a pull-out output shaft, a pull-out output gear 144, and a timing belt. A motor, which is another drive source of this embodiment, is fixed to a motor support plate fixed to the main body frame. The extraction output shaft is also fixed to the motor support plate, and rotatably supports the extraction output gear 144 that is an output member meshing with the extraction input gear 134. The rotation of the motor is transmitted to the pull-out output gear 144 via the timing belt.

  The configuration in which the motor output shaft and the rotary member provided on another shaft are connected by the belt member (the configuration in which the first stage of the reduction mechanism is driven by the belt) can reduce the noise level during operation. Further, by using such a belt member as a drive unit integrated with a motor, assembly becomes easier and maintainability is improved as compared with a configuration in which the belt member also needs to be attached and detached when attaching and detaching the motor. The other motors of the drive module 140 are also unitized. However, in the detachable structure of the drive unit described below, a drive unit not equipped with a belt drive (for example, instead of the pulley 142a, an output gear that meshes with the input gear of the driven unit is directly attached to the motor output shaft). Applicable configuration).

  Here, as shown in FIGS. 5 and 6A, protrusions 156 and 157 for positioning the motor unit 141 and the manual feeding unit 65 are formed on the front support plate 151. The protrusions 156 and 157 are integrally molded with the front support plate 151 with a resin material. Polycarbonate / acrylonitrile-butadiene-styrene mixed resin (PC + ABS), for example, can be used as a resin material that can form a three-dimensional shape such as the protrusions 156 and 157 relatively easily and has mechanical strength and heat resistance. Note that the protrusions 156 and 157 project through the opening of the right rear frame 202 when the front support plate 151 is fixed to the right rear frame 202 (FIG. 5). The right rear frame 202 of this embodiment is formed by punching and bending a metal plate as a material.

  The protrusion 156 is defined as a positive Y-axis direction (a direction from the rear side to the front side of the image forming apparatus 1; hereinafter, referred to as a first Y-axis direction Y1) with respect to the front support plate 151 extending substantially perpendicular to the Y-axis direction. ) Is protruding toward. The first Y-axis direction Y1 is the first direction in which the protrusion 156 of this embodiment projects. As shown in FIG. 6B, the outer surface 156a, which is the downstream surface of the protrusion 156 in the first Y-axis direction Y1, has a convex shape protruding in the first Y-axis direction Y1. On the other hand, the inner surface 156b, which is the upstream surface of the protrusion 156 in the first Y-axis direction Y1, has a concave shape that is recessed from the front support plate 151 in the first Y-axis direction Y1.

  Further, as shown in FIG. 6C, the outer surface 156a of the protrusion 156 has a rounded rectangular shape in which guide surfaces a1 and a2 extending in the X-axis direction are provided on both sides in the Z-axis direction. There is. On the other hand, the inner surface 156b of the protrusion 156 is partitioned by a plate-shaped partition 156c, and is formed in a shape suitable for fitting with a cylindrical shaft member. That is, the partition 156c is provided at a position circumscribing the circle c1 into which the semicircular portion located at one end of the inner surface 156b is inserted. Therefore, the shaft member engaged with the inner surface 156b is restricted from moving in the X-axis direction by the partition 156c. As will be described later, the protrusion 156 engages the manual feeding unit 65 on the outer surface 156a and engages the motor unit 141 on the inner surface 156b.

  Further, like the protrusion 156, the protrusion 157 has a convex outer surface protruding in the first Y-axis direction Y1 and a concave inner surface recessed in the first Y-axis direction Y1. It projects in the first Y-axis direction Y1. However, the outer surface of the protrusion 157 does not have a guide surface extending in the X-axis direction and is formed in a substantially columnar shape. As will be described later, the protrusion 157 engages with the manual feeding unit 65 on the outer surface and engages with the motor unit 241 on the inner surface.

  Each of the protrusions 156 and 157 is an example of a protrusion provided on the apparatus body. Therefore, in this embodiment, when the protrusion 156 is the first protrusion, the protrusion 157 as the second protrusion is provided.

(Detachment of manual feeding unit)
In the present embodiment having the above-described configuration, the operation of attaching and detaching the manual feeding unit 65 to and from the apparatus main body 1A will be described with reference to FIGS. 8 to 10 show how the manual feeding unit 65 is inserted into the apparatus main body 1A in the order of (a), (b), and (c). 8A to 8C are cross-sectional views for explaining the engagement between the guide groove 135 of the manual feeding unit 65 and the protrusions 156 and 157. 9A to 9C are cross-sectional views for explaining the positional relationship between the rotation shaft of the output gear and the rotation shaft of the input gear. 10A to 10C are cross-sectional views for explaining the meshing of the output gear and the input gear. The cross section of FIG. 8 is located downstream of the cross section of FIG. 9 in the first Y-axis direction Y1, and the cross section of FIG. 10 is located upstream of the cross section of FIG. 9 in the first Y-axis direction Y1. The broken lines in each figure represent the positions of the fastening surfaces of the manual feeding unit 65 and the main body frame 200 when the manual feeding unit 65 is completely attached.

  The manual feeding unit 65 of the present embodiment is attached to and detached from the apparatus main body by being moved in the X-axis direction (second direction) intersecting the protruding direction (first direction) of the protrusions 156 and 157. When attaching the manual feed unit 65 to the apparatus main body 1A, first, as shown in FIG. 8A, the operator grips the manual feed unit 65 and moves it in the X-axis direction (to the right in the figure) to manually feed the manual feed unit 65. The feeding unit 65 is inserted into the opening of the main body of the apparatus which serves as a mounting space. At this time, the manual feeding unit 65 is adjusted to the posture in which the guide groove 135 is substantially horizontal (that is, the posture in which the guide groove 135 extends in the same direction as the guide surfaces a1 and a2 of the protrusion 156). Further, as shown in FIGS. 9A and 10A, at this stage, the input gears 133 and 134 of the manual feeding unit 65 are not in contact with any of the output gears 143 and 144.

  When the gear on the downstream side in the insertion direction (that is, the extraction input gear 134) approaches the protrusion 156, the tip end portion 135a of the guide groove 135 located on the downstream side in the insertion direction from the extraction input gear 134 starts to be guided by the protrusion 156. Then, as shown in FIG. 8B, when the guide groove 135 of the manual feeding unit 65 engages with the protrusion 156, the upper surface and the lower surface of the guide groove 135 face the guide surfaces a1 and a2 of the protrusion 156. .. In this state, the protrusion 156 restricts the vertical movement of the manual feeding unit 65, and the manual feeding unit 65 is maintained at a height at which it can be drivingly connected to the drive module 140. That is, the positions of the input gears 133 and 134 in the vertical direction are maintained at the positions that properly mesh with the corresponding output gears 143 and 144. Further, since the positional displacement that the manual feeding unit 65 rotates when viewed from the Y-axis direction is restricted, the posture of the manual feeding unit 65 is maintained in the subsequent inserting operation.

  That is, the guide groove 135 and the protrusion 156 are engaged with each other at a relatively early stage of the insertion operation of the manual feeding unit 65, and the position and the posture of the manual feeding unit 65 are regulated. Therefore, for example, the possibility that the input gears 133 and 134 collide with the body frame and are damaged is reduced.

  As shown in FIGS. 9B and 10B, when the feed output shaft 146 passes below the rotation shaft 137 of the pull-out input gear 134, the feed output gear 143 is engaged with the original engagement partner. The feed input gear 133, which is different from the feed input gear 133, comes into contact with the pull-out input gear 134. Here, in the present embodiment, as the feed input gear 133 and the pull-out input gear 134, gears having the same specifications (that is, modules having the same number of teeth and tooth shapes) are used. Therefore, when the feed output gear 143 and the pull-out input gear 134 come into contact with each other, the pull-out input gear 134 having a smaller load than the feed output gear 143 idles in the clockwise direction in FIG. 10B. Therefore, the smooth insertion of the manual feeding unit 65 is not hindered.

  When the manual feeding unit 65 is further inserted, the guide groove 135 engages with the other protrusion 157. Then, as shown in FIG. 8C, when the manual feeding unit 65 is pushed all the way in, a part of the manual feeding unit 65 comes into contact with the main body frame 200 of the apparatus main body 1A to complete the insertion. As shown in FIG. 10C, a seating surface 132a is provided on the rear frame 132 of the manual feeding unit 65, and the seating surface 132a is brought into contact with the right rear frame 202 of the apparatus body 1A to complete the insertion. .. A similar seating surface is also provided on the front frame 131 (FIG. 3) of the manual feeding unit 65. The guide groove 135 is formed with a sufficient length so that the protrusion 156 does not contact the end portion of the guide groove 135 in the X-axis direction before the insertion of the manual feeding unit 65 is completed.

  When the insertion of the manual feeding unit 65 is completed, the feed output gear 143 and the feed input gear 133 mesh with each other, and the pull-out output gear 144 and the pull-out input gear 134 mesh as shown in FIG. Fit. That is, the manual feed unit 65 and the motor units 141 and 241 are drive-connected by the operation of inserting the manual feed unit 65 while engaging the guide groove 135 and the protrusions 156 and 157. When the front frame 131 and the rear frame 132 are fastened to the main body frame 200 with fasteners such as screws in a state in which the manual feeding unit 65 is completely inserted, the attachment of the manual feeding unit 65 is completed. To do.

  In the process from the state of FIG. 10B to the state of FIG. 10C, the feed input gear 133 and the feed output gear 143 contact each other, but the feed input gear 133 causes the feed output gear 143 to move. Since the load is smaller, the feed output gear 143 idles in the clockwise direction in the figure. On the other hand, when the pull-out output gear 144 comes into contact with the pull-out input gear 134, the pull-out input gear 134 with a smaller load idles in the clockwise direction in the figure.

  When removing the manual feeding unit 65 from the apparatus main body, the operator releases the fixing to the main body frame 200, and then pulls out the manual feeding unit 65 in the X-axis direction (to the left in FIGS. 8 to 10). As a result, the input gears 133 and 134 are disengaged from the output gears 143 and 144 by reversing the process of attachment, and the drive connection between the manual feeding unit 65 and the motor units 141 and 241 is released.

  Here, when the manual feeding unit 65 and the motor unit 141 are mounted on the apparatus main body, the protrusion 156 engages with the guide groove 135 on the outer surface 156a and engages with the feed output shaft 146 on the inner surface 156b. Therefore, as shown in FIG. 9C, the feeding output shaft 146 is positioned at a position apart from the rotation shaft 136 of the feeding input gear 133 in a substantially downward vertical direction by a predetermined distance.

  This predetermined distance is determined by the distance from the rotation shaft 136 of the feed input gear 133 to the guide groove 135, the position of the protrusion 156 with respect to the guide groove 135, and the position of the feed output shaft 146 with respect to the protrusion 156. Of these, the distance from the rotating shaft 136 to the guide groove 135 is basically determined by the structure of the manual feeding unit 65 and therefore does not change. Further, the variation of the position of the protrusion 156 with respect to the guide groove 135 and the variation of the position of the feeding output shaft 146 with respect to the protrusion 156 can be suppressed by setting the play between the protrusion 156 and the guide groove 135 and the feeding output shaft 146 small. .. Therefore, due to the action of the protrusion 156, as shown in FIG. 10C, the manual feed unit 65 and the motor are arranged so that the axial distance between the feed input gear 133 and the feed output gear 143 is maintained at a desired value. The unit 241 can be positioned with high accuracy.

  The above description also applies to the protrusion 157. That is, when the manual feeding unit 65 and the motor unit 241 are mounted on the apparatus main body, the protrusion 157 engages the guide groove 135 on the outer surface and engages the pull-out output shaft 147 on the inner surface. Therefore, as shown in FIGS. 9C and 10C, the pull-out output shaft 147 is positioned at a position separated from the rotary shaft 137 of the pull-out input gear 134 by a predetermined distance downward in the vertical direction. The axial distance between 134 and the pull-out output gear 144 is maintained with high accuracy.

(Detachment of motor unit)
Next, attachment and detachment of the motor unit 141 with respect to the apparatus body will be described with reference to FIG. FIG. 11 is a cross-sectional view of the manual feed section in which the motor unit 141 is attached to the apparatus body (a) and removed (b), taken along a plane perpendicular to the X-axis direction.

  As shown in FIG. 11A, when the motor unit 141 is attached to the main body of the apparatus, the tip of the feeding output shaft 146 engages with the inner surface 156 b of the protrusion 156 and guides the manual feeding unit 65. The groove 135 engages with the outer surface 156a of the protrusion 156. In the present embodiment, the range in the Y-axis direction in which the feed output shaft 146 and the inner surface 156b are engaged and the range in the Y-axis direction in which the guide groove 135 and the outer surface 156a are engaged are at least partially. It is configured to overlap. FIG. 11A shows a region L where the two engagement ranges overlap in this embodiment.

  With this configuration, when the motor unit 141 and the manual feed unit 65 are attached to the apparatus main body, a part of the load applied from the manual feed unit 65 to the protrusion 156 is supported by the feed output shaft 146. Therefore, it becomes easier to secure the necessary strength as compared with the case where the load of the manual feeding unit 65 is supported by the protrusion 156 whose inner surface 156b is not supported. In other words, even if the thickness of the protrusion 156 is thin, it is possible to prevent the protrusion 156 from being deformed by the load of the manual feeding unit 65. Particularly, in this embodiment, since the protrusion 156 is made of a resin material and the feeding / output shaft 146 is made of a metal material, the creep deformation of the protrusion 156 can be suppressed.

  The inner surface 156b of the protrusion 156 in this embodiment is formed such that the inner diameter of the region near the tip of the protrusion 156 is smaller than the inner diameter of the opening of the inner surface 156b of the front support plate 151. That is, the feeding output shaft 146 is engaged with the inner surface 156b of the protrusion 156 within a range from the tip to a certain length. Further, the engagement range of the guide groove 135 and the outer surface 156a in the present embodiment refers to a range in which the guide surfaces a1 and a2 of the protrusion 156 and the upper surface and the lower surface of the guide groove 135 overlap each other when viewed in the vertical direction.

  When removing the motor unit 141 from the apparatus main body, the motor unit 141 is pulled out in the Y-axis direction (upstream in the first Y-axis direction Y1) after releasing the fastening between the motor support plate 145 and the rear support plate 152. FIG. 11B shows the manual feeding unit with the motor unit 141 removed. By the operation of pulling out the motor unit 141, the feeding output gear 143 is disengaged from the feeding input gear 133, and the feeding output shaft 146 is disengaged from the inner surface 156b of the protrusion 156. At this time, the guide groove 135 of the manual feeding unit 65 and the outer surface 156a of the protrusion 156 are maintained in the engaged state, so that the manual feeding unit 65 is prevented from being displaced.

(Summary of this embodiment)
The advantages of the present embodiment described above will be described in comparison with the reference example shown in FIG. The configuration of this reference example is different from the present embodiment in that the feeding output shaft 146 of the motor unit 141 directly engages with the guide groove 135 of the manual feeding unit 65. That is, the leading end of the feed output shaft 146 projects in the Y-axis direction through the opening of the front support plate 151A.

  Also in the configuration of this reference example, by pulling out the motor unit 141 to the upstream side in the first Y-axis direction Y1, it is possible to remove the motor unit 141 with the manual feeding unit 65 attached to the apparatus main body. However, in this configuration, by removing the motor unit 141, the engagement between the guide groove 135 and the feeding output shaft 146 is lost, and as a result, the manual feeding unit 65 may be displaced. For example, the play between the screw fixing the frame of the manual feeding unit 65 to the main body frame and the hole provided in the frame for passing the screw may cause the manual feeding unit 65 to drop downward. Conceivable. If there is such a displacement, a strong force is required to engage the feeding output shaft 146 with the guide groove 135 when the motor unit 141 is attached to the apparatus main body again, or the feeding output shaft 146 is engaged. It may not be possible to engage 146 with the guide groove 135.

  On the other hand, according to the present embodiment, in the state where the feed output shaft 146 is engaged with the inner surface 156b of the projection 156 and the guide groove 135 is engaged with the outer surface 156a of the projection 156, the motor unit 141 is Further, the manual feeding unit 65 is fixed to the apparatus main body. In other words, with the convex portion of the drive unit engaging the concave shape of the protruding portion and the concave portion of the driven unit engaging the convex shape of the protruding portion, the drive unit and the driven unit are It has been fixed against.

  As a result, even if the drive unit is removed from the apparatus body while the drive unit is fixed to the apparatus body, the engagement state between the driven unit and the protrusion is maintained, so that the position of the drive unit is The deviation is suppressed. Such an advantage is also obtained when the driven unit is removed from the apparatus body while the driving unit is fixed to the apparatus body. That is, with the configuration of the present embodiment, it is possible to easily attach and detach the unit, and it is possible to provide a drive transmission mechanism, a sheet conveying device, and an image forming apparatus with improved maintainability.

(Modification)
In the above embodiment, the feed input gear 133 and the pull-out input gear 134 are helical gears having the same specifications, but they may be replaced with spur gears having the same number of teeth and modules, for example.

  Further, the feed output shaft 146 and the guide groove 135 in the above-described embodiment are examples of a convex portion and a concave portion that engage with the convex shape and the concave shape of the protrusion, respectively. For example, instead of the feed output shaft 146 supporting the output gear of the drive unit, a shaft member supporting an idler gear for transmitting drive between the gear attached to the motor output shaft and the output gear of the drive unit may be replaced. You may use as a convex part. Further, for example, the rotation shaft 136 of the feed input gear 133 may be used as a convex portion to be fitted into the concave shape provided on the motor support plate 145 of the motor unit 141.

  In the above embodiment, the motor unit 141 is removed from the apparatus main body toward the rear of the image forming apparatus 1, and the manual feeding unit 65 is removed from the apparatus main body toward the right of the image forming apparatus 1. did. That is, in the above-described embodiment, the attachment / detachment directions of the drive unit and the driven unit intersect substantially vertically. Instead of this, the driving unit and the driven unit may be detached in the substantially opposite directions with respect to the protruding portion (on the upstream side and the downstream side in the first direction in which the protruding portion projects). In this case, it is preferable that the concave portion that engages with the convex shape of the protrusion has a hole shape that fits into a convex shape, for example, instead of the groove shape such as the guide groove 135.

  Further, in the above-described embodiment, the motor unit 141 and the manual feeding unit 65 that are attached to the apparatus main body 1A of the image forming apparatus 1 have been described, but the technique illustrated in the present embodiment is not limited to other driving units and driven elements. It can also be applied to a combination of units. For example, the feeding unit 70 for the feeding cassette (FIG. 1) and the motor unit 341 (FIG. 6) for driving the feeding unit 70 can be attached to and detached from the apparatus main body 1A, and the protrusion for positioning the motor unit 341 and the feeding unit 70 The unit may be provided in the apparatus main body. In addition, the present technology may be applied to a driving unit and a driven unit that are attached to the apparatus body of an auxiliary device that is connected to the image forming apparatus. Examples of the attached device include an optional feeder that feeds sheets to the apparatus body, and a sheet processing apparatus that performs processing such as binding processing on the sheets discharged from the apparatus body after image formation.

1 ... Image forming apparatus / 1A, 151, 152, 202 ... Apparatus main body (front supporting plate, rear supporting plate, right rear frame) / 1B ... Image forming means (image forming unit) / 60 ... Sheet conveying device (manual feeding) Part) / 65 ... Driven unit (manual feeding unit) / 133,134 ... Input gear (feeding input gear, extraction input gear) / 135 ... Recessed shape (guide groove) / 141, 241 ... Drive unit (motor unit) ) / 142 ... Drive source (motor) / 143, 144 ... Output gear (feeding output gear, extraction output gear) / 156 ... Projection portion, first projection portion (projection) / 156a ... Convex shape (outer surface) / 156b ... concave shape (inner surface) / 157 ... projection portion, second projection portion (projection) / a1, a2 ... guide surface

Claims (11)

A drive unit having a drive source and an output gear connected to the drive source;
A driven unit that has an input gear that engages with the output gear and that is driven by the driving force of the drive source;
An apparatus body to which the drive unit and the driven unit are attached,
The downstream surface of the apparatus main body in the first direction has a convex shape projecting in the first direction, and the upstream surface of the first direction has a concave shape recessed in the first direction. And a protrusion formed as
A protrusion provided on either one of the drive unit and the driven unit,
A recess provided in the other of the drive unit and the driven unit,
The drive unit and the driven unit are connected to the apparatus main body in a state where the convex portion is engaged with the concave shape of the projection portion and the concave portion is engaged with the convex shape of the projection portion. Fixed to the
A drive transmission mechanism characterized by the above. The output gear is a gear that rotates about a first axis,
The input gear is a gear that rotates about a second axis parallel to the first axis,
The convex portion is arranged on the first axis or the second axis,
The drive transmission mechanism according to claim 1, wherein: The convex portion is a part of a shaft member that rotatably supports the output gear or the input gear,
The drive transmission mechanism according to claim 2, wherein. A range in the first direction in which the convex portion and the concave shape engage, and a range in the first direction in which the concave portion and the convex shape engage, overlap with each other,
The drive transmission mechanism according to claim 1, wherein the drive transmission mechanism is a drive transmission mechanism. The protrusion is made of a resin material,
The convex portion is formed of a metal material,
The drive transmission mechanism according to claim 4, wherein. The one of the drive unit and the driven unit is connected to the device body along the first direction in a state where the other of the drive unit and the driven unit is fixed to the device body. It is removable and
The other of the drive unit and the driven unit is along a second direction intersecting the first direction in a state where the one of the drive unit and the driven unit is fixed to the apparatus main body. Detachable from the device body,
The drive transmission mechanism according to claim 1, wherein the drive transmission mechanism is a drive transmission mechanism. The protrusion has a guide surface extending in the second direction,
The concave shape is a groove shape extending in the second direction, and is engaged with the guide surface.
The drive transmission mechanism according to claim 6, wherein. A second protrusion that is provided on the one of the drive unit and the driven unit with the protrusion as the first protrusion and is located at a position different from the first protrusion in the second direction. Further comprising a second protrusion arranged in
The recess has a groove shape extending in the second direction and is engaged with the first protrusion and the second protrusion.
The drive transmission mechanism according to claim 6 or 7, wherein. The one of the drive unit and the driven unit is the drive unit,
The other of the drive unit and the driven unit is the driven unit,
The drive transmission mechanism according to claim 1, wherein: A drive transmission mechanism according to any one of claims 1 to 9,
A sheet conveyance unit that is driven by the driving force transmitted from the drive transmission mechanism and that conveys a sheet.
A sheet conveying device characterized by the above. A sheet conveying device according to claim 10;
Image forming means for forming an image on a sheet conveyed by the sheet conveying device,
An image forming apparatus characterized by the above.

Images