JP6351445B2 - Paper transport device, document feeder, and image forming apparatus - Google Patents

Description

  The present invention relates to a sheet conveying apparatus, a document feeding apparatus, and an image forming apparatus having an anti-rotation mechanism portion of an electromagnetic clutch coupled to a rotation shaft of a conveying roller that conveys a sheet.

  In an electrophotographic image forming apparatus such as a copying machine or a printer, a plurality of conveying rollers among various conveying rollers arranged in a sheet conveying path are connected to a driving device.

  In this case, the drive source of the drive device is always driven, but the transport roller connected to the drive source is driven and driven as necessary in consideration of the transport timing of the paper. There are things that need to be switched between stop and stop.

  For this reason, an electromagnetic clutch is connected to such a conveying roller on the rotation shaft of the conveying roller, and the driving and driving of the conveying roller are switched by turning on and off the electromagnetic clutch.

  In this case, in the electromagnetic clutch coupled to the rotating shaft, when the electromagnetic clutch is turned on, the support member arranged to support the electromagnetic clutch may rotate together with the rotating shaft.

  In view of this, a transmission device provided with a rotation prevention mechanism portion for preventing rotation of a support member arranged to support the electromagnetic clutch when the electromagnetic clutch is on, and an image forming apparatus having the transmission device have been proposed. (For example, refer to Patent Document 1).

  FIG. 11 shows a configuration example of a rotation preventing mechanism provided in the transmission device described in Patent Document 1. This anti-rotation mechanism part fits an engagement concave part 153 of the anti-rotation part 152 provided on the support member 151 supporting the electromagnetic clutch 150 on an engagement convex part 142 formed by cutting and raising one piece of the frame 140. Thus, the structure is engaged.

JP 2008-26472 A

  By the way, in a paper transport apparatus having a configuration in which a transport roller having an electromagnetic clutch coupled to a rotating shaft is disposed in a paper transport path, a number of components (gears, pulleys, etc.) including the transport roller are disposed along a narrow paper transport path. Is done.

  For this reason, when a transport roller to which an electromagnetic clutch is connected is attached to a predetermined paper transport path, a large number of gears, pulleys, and the like are disposed around the transport roller, so that the transport roller is disposed at a predetermined position with poor visibility. There was a need.

  Therefore, if there is an electromagnetic clutch in a mounting portion with poor visibility, it is difficult to align the engagement recess 153 of the electromagnetic clutch 150 so as to sandwich the engagement projection 142 of the frame 140 in the configuration shown in FIG. There was a problem that assembly mistakes such as attaching the engaging concave portion 153 in a state of being detached from the engaging convex portion 142 are likely to occur.

  That is, in the structure in which the engagement concave portion 153 of the electromagnetic clutch 150 is fitted so as to sandwich the engagement convex portion 142 formed by cutting and raising the frame 140, the engagement convex portion 142 of the frame 140 is engaged with the engagement of the electromagnetic clutch 150. Although it is necessary to insert between the narrow grooves of the recess 153, even when the engagement recess 153 of the electromagnetic clutch 150 is slightly displaced (rotated) in the direction around the axis of the rotation shaft when attached, the engagement recess 153 is It will come off from the part 142 easily.

  When the electromagnetic clutch 150 is operated in a state where the engagement concave portion 153 is disengaged from the engagement convex portion 142, the anti-rotation portion 152 also rotates with the rotation of the clutch, and hits and is damaged by surrounding gears, pulleys, and the like. Problem occurs.

  The present invention was devised to solve such problems, and an object of the present invention is to eliminate the mounting error of the rotation prevention mechanism provided in the electromagnetic clutch when the conveying roller is arranged in the sheet conveying path. It is an object of the present invention to provide a sheet conveying device, a document feeding device and an image forming apparatus having the same.

  In order to solve the above-described problems, a paper transport device according to the present invention includes a transport roller that transports a paper, an electromagnetic clutch attached to a rotation shaft of the transport roller, a support member that supports the electromagnetic clutch, and the support member. And a rotation restricting portion that restricts the rotation of the rotation preventing portion, and the rotation restricting portion restricts the rotation of the support member by sandwiching an outer portion of the rotation preventing portion. It is configured.

  According to this configuration, when the conveyance roller is attached, even if the rotation stop portion of the electromagnetic clutch is displaced (rotated) in the direction around the rotation shaft, the rotation stop portion is not attached to the rotation restriction portion. , Can eliminate installation mistakes.

According to the paper conveying device of the present invention, the electromagnetic clutch is disposed in an opening formed in a frame, and the rotation restricting portion is formed by a member of an opening portion when the opening is formed from the frame. It is as formed configuration.

  According to this configuration, the punched portion of the frame that is originally discarded to form the opening can be used effectively as the rotation restricting portion.

  Further, according to the paper transport device of the present invention, the rotation restricting portion includes a pair of rotation restricting pieces extending from the edge of the opening, and the outer portion of the rotation stopping portion is the rotation restricting piece. The rotation is restricted by being inserted between them.

  According to this configuration, even when the rotation stop portion of the electromagnetic clutch is displaced (rotated) in the direction around the rotation shaft when the transport roller is attached, the rotation stop portion does not come off the rotation restriction portion.

  Further, according to the paper transport device of the present invention, the opening portions on both outer sides of the rotation restricting piece in the opening portion have a shape in which the rotation stopping portion is not inserted.

  According to this configuration, when the conveyance roller is attached, even if the rotation stop portion of the electromagnetic clutch is displaced (rotated) in the direction around the rotation shaft, the rotation stop portion is inserted away from the rotation restriction portion. It is possible to eliminate mounting mistakes.

  Moreover, according to the paper conveying apparatus of the present invention, the pair of rotation restricting pieces may be bent in the same direction, and the bent tip portions may be connected to each other.

  According to this configuration, the rigidity of the rotation restricting piece can be increased, and the vibration of the rotation restricting piece can be reduced.

  Further, according to the paper transport device of the present invention, a buffer member may be provided at a portion where the rotation restricting portion and the rotation stop portion are in contact with each other.

  According to this configuration, the shock noise when the electromagnetic clutch is operated can be reduced by providing the buffer member.

Moreover, according to the paper conveying apparatus of this invention, a phosphor bronze board can be used suitably as a buffer member. The phosphor bronze plate may be loosely fitted between the rotation restricting portion and the rotation stopping portion.

  According to this configuration, since the phosphor bronze plate is excellent in slipperiness, it is possible to reduce an impact sound when the electromagnetic clutch is operated.

  Further, the document feeder of the present invention is configured to include the paper transport device having the above-described configurations.

  Further, the image forming apparatus of the present invention is configured to include the paper conveying device having the above-described configurations.

  Since the present invention is configured as described above, even when the rotation stop portion of the electromagnetic clutch is displaced (rotated) in the direction around the rotation shaft when the transport roller is attached, the rotation stop portion is disengaged from the rotation restriction portion. It is possible to eliminate mounting mistakes.

1 is a schematic cross-sectional view of an image forming apparatus according to an embodiment of the present invention as viewed from the front. It is a schematic sectional drawing which expands and shows the part of a conveyance path. It is a schematic sectional drawing which expands and further shows the part of the conveyance path shown in FIG. FIG. 3 is a schematic perspective view of the document feeder viewed from the back side. FIG. 5 is a perspective view schematically showing a part extracted from parts arranged in a conveyance path of the document feeder. It is the perspective view which looked at the structure of the rotation prevention mechanism part of the electromagnetic clutch provided in the registration roller of the drive side from the apparatus front side. It is the perspective view which looked at the structure of the rotation prevention mechanism part of the electromagnetic clutch provided in the registration roller of the drive side from the apparatus back side. It is the front view which looked at the structure of the rotation prevention mechanism part of the electromagnetic clutch provided in the registration roller of the drive side from the apparatus front side. It is a perspective view which shows the whole structure of a buffer member. It is sectional drawing which shows the state which provided the buffer member between the rotation prevention piece and the rotation control piece. It is a front view which shows one structure of the conventional rotation prevention mechanism part.

  Embodiments of the present invention will be described below with reference to the drawings.

<Embodiment 1>
In the first embodiment, a case will be described in which the sheet conveying device of the present invention is applied to a document feeder mounted in an image forming apparatus.

-Description of overall configuration of image forming apparatus-
FIG. 1 is a schematic cross-sectional view of the image forming apparatus according to the first embodiment when viewed from the front.

  An image forming apparatus 1 shown in FIG. 1 includes an in-body discharge space portion formed in a U-shaped cross section between an apparatus main body 10 having an image forming unit and an image reading housing having an image reading unit 20 for a document. 13 is an in-body discharge type image forming apparatus in which 13 is formed.

  The in-body discharge space 13 is formed by an inner bottom surface 10 a, an inner side surface 10 b, and an inner back surface 10 c of the apparatus main body 10, and the upper portion of the space is closed by the image reading unit 20. A paper space is formed. An inner bottom surface 10a of the apparatus main body 10 is a sheet discharge tray 17, and a sheet discharge roller 136 described later is disposed on the inner back surface 10c.

  A document feeder (ADF) 30 is provided on the upper part of the image reading unit 20, and this document feeder 30 rotates a hinge (not shown) provided at an edge on the back side of the upper surface of the image reading unit 20. The front side is provided as a moving center so that it can be opened and closed in the vertical direction (that is, it can be opened and closed with respect to the image reading unit 20).

  In the image forming apparatus 1 having such a configuration, a color image using each color of black (K), cyan (C), magenta (M), and yellow (Y), or a monochrome image using a single color (for example, black). The image data corresponding to is handled. The image forming unit 104 is provided with four developing devices 112 for forming four types of toner images, a photosensitive drum 113, a cleaning device 114, and four chargers 115, each of which includes black, cyan, magenta, and Corresponding to yellow, four image stations Pa, Pb, Pc, and Pd are configured.

  An intermediate transfer belt 121 is disposed on the upper side of the photosensitive drum 113. The intermediate transfer belt 121 circulates in the direction of arrow C, the residual toner is removed and collected by the belt cleaning device 125, and the toner images of the respective colors formed on the surfaces of the photosensitive drums 113 are sequentially transferred and superimposed. Thus, a color toner image is formed on the surface of the intermediate transfer belt 121.

  A nip area is formed between the transfer roller 126a of the secondary transfer device 126 and the intermediate transfer belt 121, and the sheet conveyed through the sheet conveyance path R1 is sandwiched and conveyed in the nip area. When the sheet passes through the nip area, the toner image on the surface of the intermediate transfer belt 121 is transferred and conveyed to the fixing device 117.

  The fixing device 117 sandwiches the sheet with the toner image transferred between the fixing roller 131 and the pressure roller 132 and heats and presses the sheet to fix the toner image on the sheet.

  The paper feed cassette 16 is provided below the optical scanning device 111. The paper is pulled out of the paper feed cassette 16 by the pickup roller 133a and the suction roller 133b, and is transported to the paper transport path R1. The paper discharge roller is provided in the paper discharge unit 138 via the secondary transfer device 126 and the fixing device 117. It is carried out to the paper discharge tray 17 via 136. A registration roller 134, a transport roller 135, and a paper discharge roller 136 are disposed in the paper transport path R1.

  When image formation is performed on the back side, the paper is conveyed in the reverse direction from the paper discharge roller 136 to the reverse conveyance path Rr, the front and back sides of the paper are reversed, and the paper is guided again to the registration roller 134, and Similarly, image formation is performed on the back surface, and the paper is carried out to the paper discharge tray 17.

-Description of Image Reading Unit 20-
The image reading unit 20 includes a document table glass 21, a document reading glass 22, a light source unit 23, a mirror unit 24, and an imaging unit 25.

  The light source unit 23 includes a light source 23 a that irradiates light toward the document M, and a mirror 23 b that guides reflected light from the document M to the mirror unit 24. The mirror unit 24 includes a mirror 24a and a mirror 24b. The imaging unit 25 includes a condenser lens, a CCD (Charge Coupled Device), and the like.

  Although details are omitted, the image reading unit 20 is configured to be able to perform reading by the document fixing method and reading by the document moving method.

-Description of Document Feeder 30-
FIG. 2 is an enlarged schematic cross-sectional view showing a portion of the document transport path of the document feeder 30.

  The document feeder 30 includes a document tray 31 on which a document (paper) M is placed, a discharge tray 32 from which the document M is discharged, and a document M placed on the document tray 31 from the document tray 31 at a reading position P1. A main conveyance path 50 that conveys the original M that has been conveyed to the reading position P1 to the discharge tray 32, and a reverse conveyance path that returns the original M that has passed the reading position P1 to the main conveyance path 50. 54. The reading position P <b> 1 is a position where light is emitted from the light source 23 a through the document reading glass 22.

  A pickup roller 34 is provided in the vicinity of the document tray 31. The pickup roller 34 is provided for taking the document M placed on the document tray 31 into the main transport path 50 in order from the top.

  In the vicinity of the pickup roller 34, a paper feed roller 35a and a suction roller 35b are provided. The suction roller 35b is provided to prevent the plurality of documents M from being transported to the main transport path 50 in a state where they overlap each other (double feeding).

  The main conveyance path 50 includes a curved conveyance path 52 formed in a U shape when viewed from the front. Specifically, the main conveyance path 50 is formed so as to be folded back from the document tray 31 toward the reading position P <b> 1 through the straight conveyance path 51 and the curved conveyance path 52.

  The sub transport path 53 is formed so as to extend from the reading position P1 to the downstream side in the paper transport direction Y (the discharge tray 32 side). The reverse conveyance path 54 is provided between the main conveyance path 50 and the sub conveyance path 53, from the junction P <b> 2 with the straight conveyance path 51 of the main conveyance path 50 to the junction P <b> 3 with the sub conveyance path 53. This is the route. That is, a circulation path is formed by the curved conveyance path 52, the sub conveyance path 53, and the reverse conveyance path 54 of the main conveyance path 50. The sub-transport path 53 between the junction P3 and the discharge tray 32 functions as a switchback path for switching between the leading edge and the trailing edge of the document M with respect to the sheet transport direction Y.

  The main conveyance path 50 is provided with a registration roller pair 36, a conveyance roller pair 37, and a registration roller pair 38, and the sub conveyance path 53 is provided with a conveyance roller pair 39, a conveyance roller pair 41, and a discharge roller pair 42. Yes.

  The conveyance roller pair 41 and the discharge roller pair 42 are disposed between the junction P3 and the discharge tray 32. The conveyance roller pair 41 includes a driving roller 41a and a driven roller 41b. The discharge roller pair 42 includes a driving roller 42a and a driven roller 42b.

  A claw member 40 is provided in the vicinity of the junction P3. The claw member 40 is configured to open the sub-transport path 53 by being pushed up by the document M when the document M is transported in the sub-transport path 53 in the paper transport direction Y.

  The above is the description of the overall configuration of the image forming apparatus 1.

  In the first embodiment, since the paper conveying device of the present invention is mounted on the document feeder 30, the document feeder 30 will be described in more detail with reference to FIGS. However, FIG. 3 is a schematic cross-sectional view showing a further enlarged portion of the document conveyance path shown in FIG. 2, and FIG. 4 is a diagram showing the document feeder 30 from the back side (that is, the side opposite to FIGS. 1 and 2). FIG. 5 is a perspective view schematically showing a part extracted from the parts arranged in the conveyance path portion of the document feeder 30 shown in FIG. FIG. 4 shows a state in which the upper cover 60 shown in FIG. 2 is opened and removed.

  The document conveyance path is formed by a pair of guides that are plate-like bodies.

  More specifically, as shown in FIG. 3, the inner peripheral guide 71 forms the inner peripheral surface of the main transport path 50 and the sub transport path 53 and the inner peripheral surface of the reverse transport path 54. An outer peripheral guide 72 is disposed outside the inner peripheral guide 71, and a main transport path 50, a sub transport path 53, and a reverse transport path 54 are formed between the inner peripheral guide 71 and the outer peripheral guide 72.

  Two driving-side registration rollers 36 a and 38 a are provided inside the inner peripheral guide 71, and a part of the two driving-side registration rollers 36 a and 38 a is conveyed from the openings of the inner peripheral guide 71. Each protrudes into the road. The outer peripheral guide 72 is provided with two driven-side registration rollers 36b and 38b, and the driven-side registration rollers 36b and 38b pass through the respective openings to drive two registration rollers 36a and 38a. Are pressed against each other.

  Similarly, two drive-side transport rollers 37 a and 39 a are provided inside the inner peripheral guide 71, and a part of the two drive-side transport rollers 37 a and 39 a is provided in each opening of the inner peripheral guide 71. Respectively projecting into the conveyance path. Further, the outer peripheral guide 72 is provided with two driven-side transport rollers 37b and 39b, respectively, and the driven-side transport rollers 37b and 39b are respectively driven by the drive-side two transport rollers 37a and 39a. Are pressed against each other.

  Further, a conveyance roller pair 41 is disposed downstream from the junction P3 in the sheet conveyance direction Y, and a discharge roller pair 42 is disposed further downstream.

  Further, as shown in FIGS. 4 and 5, a drive system of the document feeder 30 is provided on one side (the apparatus back side) of the inner peripheral guide 71. In this drive system, a paper feed motor 73, a transport motor 74, registration roller electromagnetic clutches (hereinafter simply referred to as electromagnetic clutches) 75, 76, and the like are provided.

  The paper feed motor 73 rotates the pickup roller 34 and the paper feed roller 35a. Although not shown, a pulley is fixed to the output shaft of the paper feed motor 73, the pulley is fixed to the shaft 35a1 of the paper feed roller 35a, and an endless belt is bridged between both pulleys. The rotation of the output shaft is transmitted to the shaft 35a1 of the paper feed roller 35a through each pulley and an endless belt to rotate the paper feed roller 35a. Further, as shown in FIG. 3, the rotation of the paper feed roller 35a is transmitted to the pickup roller 34 through the pulleys 81 and 82 and the endless belt 83, thereby rotating the pickup roller 34. The pickup roller 34 is supported so as to be rotatable about the shaft 35a1 of the paper feed roller 35a. When the paper feed roller 35a and the pickup roller 34 are driven to rotate, a rotational moment is generated around the shaft 35a1 of the paper feed roller 35a, and the pickup roller 34 is rotated about the shaft 35a1 of the paper feed roller 35a to move the document. The original M is pressed against the original M on the tray 31, and the original M is pulled out by the pickup roller 34.

  The conveyance motor 74 rotationally drives the registration roller pairs 36 and 38, the conveyance roller pairs 37, 39 and 41, and the discharge roller pair 42. The rotational driving force of the output shaft of the conveyance motor 74 is a driving force obtained by combining a plurality of gears 77, a plurality of pulleys 78, a plurality of endless belts 79, etc. (only part of which is shown in FIG. 5). Each of the rollers 36a, 37a, 38a, 39a, 41a, 42a on the driving side is transmitted to the respective shafts (rotating shafts) 36a1, 37a1, 38a1, 39a1, 41a1, 42a1 through the transmission mechanism, and each of the rollers 36a, 37a, 38a, 39a, 41a, 42a rotate.

  The registration roller pairs 36 and 38 are always in pressure contact with each other, and when the driving side registration rollers 36a and 38a are rotationally driven, the driven side registration rollers 36b and 38b are driven to rotate. The pair of transport rollers 37 and 39 are also always in pressure contact with each other, and when the drive-side transport rollers 37a and 39a are driven and rotated, the driven-side transport rollers 37b and 39b are driven and rotated.

  Further, as shown in FIG. 5, the electromagnetic clutches 75 and 76 are respectively attached to one ends of the shafts 36a1 and 38a1 of the drive-side registration rollers 36a and 38a, and rotate the output shaft of the transport motor 74. The drive-side registration rollers 36a and 38a are individually rotated or stopped by transmitting or blocking the shafts 36a1 and 38a1. That is, the electromagnetic clutches 75 and 76 use the shafts 36a1 and 38a1 of the registration rollers 36a and 38a as output shafts.

  Each electromagnetic clutch 75, 76 is provided with a pulley 78 for transmitting the rotational driving force of the transport motor 74 via an endless belt 79. The pulley 78 is rotatably supported by shafts 36a1 and 38a1 that are output shafts via electromagnets (not shown). Each pulley 78 is disposed concentrically with each shaft 36a1, 38a1.

  Moreover, each electromagnetic clutch 75 and 76 is provided with the supporting member 85 similarly to the electromagnetic clutch of the prior art shown in FIG. The support member 85 is rotatably supported by shafts 36a1 and 38a1 that are output shafts via bearings (not shown). The support member 85 is also provided so as to be rotatable with respect to the pulley 78.

  6 and 7 are perspective views showing the configuration of the rotation preventing mechanism portion of the support member 85 in the electromagnetic clutch 75 attached to the driving side registration roller 36a. FIG. 6 is a perspective view seen from the front side of the apparatus. FIG. 7 and FIG. 7 are perspective views as seen from the back side of the apparatus. FIG. 8 is a front view of the structure of the rotation preventing mechanism as viewed from the front side of the apparatus. Since the structure of the anti-rotation mechanism portion of the support member 85 is common to the electromagnetic clutches 75 and 76, the anti-rotation mechanism portion of the electromagnetic clutch 75 attached to the registration roller 36a is shown in FIGS. It is shown.

  The anti-rotation mechanism includes an anti-rotation portion 86 provided on the support member 85 of the electromagnetic clutch 75, and a rotation restricting portion 91 that restricts the rotation of the anti-rotation portion 86. The configuration is such that rotation is restricted by pressing (pinching) the outer shape portion of the portion 86.

  Hereinafter, the rotation stopper 86 and the rotation restricting unit 91 will be specifically described.

  In the present embodiment, the rotation stopper 86 is formed of a plate-shaped metal plate, and extends in parallel from a fixed piece 86a formed in a substantially arc shape and an arcuate edge on the outer side of the fixed piece 86a. It comprises a pair of anti-rotation pieces 86b, 86b provided.

  The fixed piece 86a is disposed on the end surface 85a of the support member 85 along the axis 36a1 of the registration roller 36a, and is fastened by a fastener 87 such as a screw or a screw (or in combination with an uneven fitting structure or an adhesive). Are fixedly attached to the end face 85a. In this attached state, the pair of anti-rotation pieces 86b, 86b are extended in a direction orthogonal to the shaft 36a1, and have a shape protruding outward from the outer peripheral portion of the cylindrical support member 85. Further, the pair of detent pieces 86b, 86b are formed so that the width W1 between the outer edge portions thereof is sufficiently wide.

  In the present embodiment, the anti-rotation pieces 86b, 86b are substantially U-shaped divided into two forks. However, it is sufficient that a sufficient width W1 can be secured as the anti-rotation piece. A rectangular plate-shaped piece may be used.

  On the other hand, the rotation restricting portion 91 is provided in an opening 92 formed in the frame 90. That is, the rotation restricting portion 91 is formed integrally with the frame 90 by punching a member of the opening portion when the opening 92 is formed from the frame 90. According to this configuration, the punching member of the frame 90 that is originally discarded to form the opening 92 can be effectively used as the rotation restricting portion 91.

  Specifically, the rotation restricting portion 91 includes a pair of rotation restricting pieces 93 and 93 extending downward from the upper edge of the opening 92, and the pair of rotation restricting pieces 93 and 93 are the same. It is bent in the direction (specifically, in an L shape toward the back of the apparatus), and the ends of the bent pieces 93a, 93a are integrally connected by a connecting piece 93b. The width W2 (mainly refer to FIG. 8) between the opposite inner edges of the rotation restricting pieces 93, 93 is sufficiently larger than the width W1 (mainly refer to FIG. 8) between the outer edges of the rotation stopper pieces 86b, 86b. Wide spacing.

  When assembling the document feeder 30, the registration roller 36 a is assembled so as to be inserted from the opening 92 of the frame 90 toward the back of the apparatus, and the electromagnetic clutch 75 is disposed in the opening 92. At this time, the rotation stopper pieces 86b and 86b are arranged so as to be inserted between the rotation restricting pieces 93 and 93 of the opening 92, thereby restricting the rotation of the support member 85 (that is, the support member 85 and the electromagnetic clutch 75 together). (Restriction of rotation)

  In this case, as described in the above problem, it is difficult to dispose the rotation stopper pieces 86b and 86b between the rotation restricting pieces 93 and 93 because the attachment portion of the electromagnetic clutch 75 has poor visibility. In this embodiment, the width W2 between the inner edge portions of the rotation restricting pieces 93, 93 is sufficiently wide, so that the detent pieces 86b, 86b are slightly displaced in the direction of the axis along the axis 36a1 (rotation). However, the rotation stopper pieces 86b and 86b can be aligned between the inner edges of the rotation restricting pieces 93 and 93.

  On the other hand, the anti-rotation pieces 86b and 86b are also formed so that the width W1 between the outer edges is sufficiently wide. Therefore, even when the rotation preventing pieces 86b and 86b are slightly displaced (rotated) along the shaft 36a1 when the registration roller 36a is attached, the rotation preventing pieces 86b and 86b are the inner edges of the rotation restricting pieces 93 and 93. Since there is no complete disengagement between the parts, it is blocked by hitting any one of the rotation restricting pieces 93, so that an assembly error such that the rotation preventing pieces 86b, 86b are attached in a state of being disengaged from the rotation restricting pieces 93, 93 also occurs. do not do.

  Moreover, in this Embodiment, the opening part (namely, the edge part of the outer side of the rotation control piece 93, and the edge part of the opening part 92 continuing to it) of the opening part of the both sides of a pair of rotation control piece 93,93 among the opening parts 92 is mentioned. The opening recesses 94, 94 formed in (1) have a shape with a reduced width so that the anti-rotation pieces 86b, 86b are not inserted.

  Specifically, the width W3 of the opening recess 94 is formed to be narrower than the width W1 between the outer edges of the pair of detent pieces 86b and 86b. Thereby, even if the rotation prevention piece 86b rotates in the direction around the axis and reaches the position of the opening recess 94 (indicated by a two-dot chain line in FIG. 8) beyond the rotation restriction piece 93, the rotation prevention piece 86b is erroneously It does not fit into the opening recess 94. That is, no assembly error occurs.

  By the way, in the present embodiment, a relatively wide gap is provided between the rotation restricting pieces 93 and 93 and the rotation preventing pieces 86b and 86b in consideration of the mounting property. Therefore, when the electromagnetic clutch 75 is actuated and the support member 85 is rotated along with this, the rotation preventing pieces 86b and 86b hit the rotation restricting pieces 93 and 93, and an impact sound (a metallic sound such as a catching or catching) is generated. Therefore, in the present embodiment, by connecting the distal ends of the bent pieces 93a and 93a with the connecting piece 93b, the vibration of the bent pieces 93a and 93a itself when the rotation preventing pieces 86b and 86b collide is reduced. Although this is configured to reduce the impact sound, this alone may not be sufficient.

  Therefore, in the present embodiment, the buffer member 95 for reducing the impact sound is provided at the portion where the rotation restricting pieces 93, 93 and the rotation preventing pieces 86b, 86b are in contact with each other.

  FIG. 9 is a perspective view showing the overall configuration of the buffer member 95, and FIG. 10 is a cross-sectional view showing a state in which the buffer member 95 is provided between the rotation stop pieces 86b and 86b and the rotation restricting pieces 93 and 93.

  The buffer member 95 has a structure that fits to the bent pieces 93a and 93a of the rotation restricting pieces 93 and 93 and the connecting piece 93b. Therefore, the buffer member 95 includes a band-shaped buffer main body 96 formed in a U-shape so as to contact the inner edge of the bent pieces 93a and 93a and the inner edge of the connecting piece 93b. The upper wing pieces 97a and 97a extend obliquely upward from the upper edges of the left and right body parts 96a and 96a of the buffer body part 96, and extend laterally from the lower edges of the left and right body parts 96a and 96a. The lower wing pieces 97b, 97b are extended. Further, a hook piece 98 extends from the upper edge of the central body portion 96b in the forward direction, and leg pieces 99, 99 extend from the rear end edges of the left and right body portions 96a, 96a to the left and right. It has an extended configuration.

  The upper wing pieces 97a and 97a and the hook piece 98 are retaining pieces for preventing the buffer member 95 from falling from between the bent pieces 93a and 93a of the rotation restricting pieces 93 and 93 and the connecting piece 93b. The lower wing pieces 97b and 97b are retaining pieces for preventing the buffer member 95 from accidentally coming out upward between the bent pieces 93a and 93a of the rotation restricting pieces 93 and 93 and the connecting piece 93b.

  As can be seen from FIG. 10, in the present embodiment, the buffer member 95 is provided in a loosely fitted state between the rotation stopper pieces 86 b and 86 b and the rotation restricting pieces 93 and 93. That is, the upper wing pieces 97a and 97a and the hook piece 98 are held in a state of being hooked on the edges of the bending pieces 93a and 93a of the rotation restricting pieces 93 and 93 and the edge of the connecting piece 93b, and are not fixed. . Therefore, each time the rotation stopper pieces 86b, 86b rotate between the rotation restricting pieces 93, 93, the buffer member 95 swings so as to slide (or to jump).

  Here, in the present embodiment, phosphor bronze is used as the material of the buffer member 95. As is well known, phosphor bronze has various characteristics such as excellent springiness, high strength, good bending and drawing workability, high electrical conductivity, good wear resistance, and excellent slipperiness. However, it is excellent in noise reduction among non-ferrous metals. The inventor conducted an experiment using a phosphor bronze plate as the buffer member 95, and confirmed that the silencing effect is superior to that when, for example, a stainless plate is used.

  That is, since phosphor bronze is excellent in slipperiness, it is possible to reduce an impact sound when the electromagnetic clutch is operated. Moreover, since phosphor bronze is excellent in wear resistance, sufficient durability can be expected, so that it is not necessary to frequently replace parts. If it is only silencer, it is also possible to use rubber or resin member as a buffer member, but this causes rapid deterioration due to impact and frequent replacement of parts, but by using a phosphor bronze plate, It is possible to save the trouble of replacing parts.

  When a resin material is used as the buffer member, for example, carbon-containing POM (Polyoxymethylene, Polyacetal) can be used in consideration of strength and the like.

<Embodiment 2>
In the first embodiment, the case where the paper transport device of the present invention is applied to the document feeder is illustrated, but the paper transport device of the present invention can also be applied to the paper transport path of the image forming unit.

  That is, since the registration roller 134 having the electromagnetic clutch is provided on the downstream side of the portion where the reverse conveyance path Rr joins on the paper conveyance path R1, the rotation prevention mechanism portion according to the present invention is provided at the electromagnetic clutch part. Apply.

<Embodiment 3>
In the first embodiment, the paper transport device of the present invention is applied to the document feeder. In the second embodiment, the paper transport device of the present invention is applied to the paper transport path of the image forming unit. The paper transport device of the present invention can also be applied to a post-processing device that performs punching, sorting, and the like on the printed paper.

  Although illustration is omitted, since a registration roller having an electromagnetic clutch is provided in the paper conveyance path even when the paper is conveyed from the image forming unit to the post-processing apparatus, the rotation stopper according to the present invention is provided at the electromagnetic clutch portion. What is necessary is just to apply a mechanism part.

  It should be noted that the embodiment disclosed herein is illustrative in all respects and does not serve as a basis for limited interpretation. Therefore, the technical scope of the present invention is not interpreted only by the above-described embodiment, but is defined based on the description of the scope of claims. Moreover, all the changes within the meaning and range equivalent to a claim are included.

DESCRIPTION OF SYMBOLS 1 Image forming apparatus 10 Apparatus main body 20 Image reading part 30 Document feeding apparatus 31 Document tray 32 Output tray 34 Pickup roller 35a Paper feed roller 35a1 shaft 35b Sakiaki roller 36 Registration roller pair 36a Registration roller 36a1 shaft (rotation shaft) on driving side
36b Drive-side registration roller 37 Conveying roller pair 37a Driving-side conveying roller 37a1 shaft (rotating shaft)
37b Conveyor roller on the driven side 38 Registration roller pair 38a Registration roller on the driving side 38a1 shaft (rotating shaft)
38b Drive side registration roller 39 Conveying roller pair 39a Driving side conveying roller 39a1 shaft (rotating shaft)
39b Conveying roller on the driven side 40 Claw member 41 Conveying roller pair 41a Drive roller 41a1 shaft (rotating shaft)
41b Follower roller 42 Discharge roller pair 42a Drive-side discharge roller 42a1 shaft (rotary shaft)
DESCRIPTION OF SYMBOLS 50 Main conveyance path 51 Straight conveyance path 52 Curved conveyance path 53 Sub conveyance path 54 Reverse conveyance path 71 Inner periphery guide 72 Outer periphery guide 73 Paper feed motor 74 Conveyance motor 75,76 Registration roller electromagnetic clutch (electromagnetic clutch)
77 Gear 78 Pulley 79 Endless belt 81, 82 Pulley 83 Endless belt 85 Support member 85a End face 86 Anti-rotation portion 86a Fixed piece 86b Non-rotating piece 87 Fastener 91 Rotation restricting portion 92 Opening portion 93 Rotation restricting piece 93a, 93a Bending Piece 93b connecting piece 94 opening recess (opening part)
95 Buffer member 96 Buffer body 96a, 96a Left and right body 96b Center body 97a, 97a Upper wing piece 97b, 97b Lower wing piece 98 Hook piece 99 Leg piece M Paper (original)
P1 Reading position P2, P3 Merge section Y Paper transport direction

Claims (7)

A transport roller for transporting paper;
An electromagnetic clutch attached to the rotating shaft of the transport roller;
A support member for supporting the electromagnetic clutch;
A rotation stop provided on the support member;
A rotation restricting portion for restricting rotation of the rotation stop portion,
The rotation restricting portion, have rows rotation restriction of the support member by sandwiching the outer portion of the rotation stopper portion,
The electromagnetic clutch is disposed in an opening formed in the frame,
The rotation restricting portion is formed by a member of an opening portion when forming the opening from the frame, and includes a pair of rotation restricting pieces extending from an edge portion of the opening,
The rotation is restricted in such a manner that the outer portion of the rotation stopper is inserted between the rotation restriction pieces,
An opening portion on both outer sides of the rotation restricting piece in the opening is shaped so that the rotation stopper is not inserted . The sheet conveying device according to claim 1 ,
The pair of rotation restricting pieces are bent in the same direction, and the bent leading ends are connected to each other. The sheet conveying apparatus according to claim 1 or 2 ,
A sheet conveying device, wherein a buffer member is provided at a portion where the rotation restricting portion and the rotation stopping portion are in contact with each other. The paper conveying device according to claim 3 ,
The paper conveying apparatus, wherein the buffer member is a phosphor bronze plate. The sheet conveying device according to claim 4 ,
The paper transporting apparatus, wherein the phosphor bronze plate is loosely fitted between the rotation restricting portion and the rotation stopping portion. An original feeding device comprising the paper transport device according to any one of claims 1 to 5 . An image forming apparatus having a sheet conveying apparatus according to any one of claims 1 to 5.

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