JP2018012566A - Sheet discharge apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent failure of sheet conveyance caused by displacement of a discharge roller in a width direction while preventing occurrence of rotation failure of the discharge roller when a frame part supporting the discharge roller at a discharge port of a sheet can be deformed by thermal expansion.SOLUTION: A driving roller 6x has a drive shaft part 62 rotatably supported by portions on both sides of a discharge port 1x of a discharge frame body 60 in a state of having play in a width direction D1 of the discharge port 1 of a body part 1, and a plurality of driving roller bodies 61 fixed to the drive shaft part 62. A regulation part 66a provided on the discharge frame body 60 or a driven roller body 66 limits displacement of the driving roller 6x in the width direction D1 to a range smaller than the play P0 by coming into contact with a regulated part 7 provided on the driving roller 6x.SELECTED DRAWING: Figure 6

Description

  The present invention relates to a sheet discharging apparatus.

  Generally, an electrophotographic image forming apparatus includes a fixing device that fixes a toner image transferred to a sheet to the sheet by heating, and a sheet that discharges the sheet after passing through the fixing apparatus to the outside of the main body. A discharge device.

  The sheet discharge device includes a discharge frame made of synthetic resin, a discharge roller, and a plurality of driven rollers. The discharge frame body forms a discharge port of the sheet to the outside of the main body. The discharge roller is a drive roller including a drive shaft portion rotatably supported by both side portions of the discharge port in the discharge frame body and a plurality of drive roller bodies fixed to the drive shaft portion. The plurality of driven rollers include a driven roller body that is disposed at a position facing the plurality of driving roller bodies and that rotates following the plurality of driving roller bodies.

  In some cases, the sheet discharge device is disposed above the fixing device in the main body of the image forming apparatus (see, for example, Patent Document 1).

JP 2005-104607 A

  By the way, when the sheet discharge device is disposed above the fixing device, the discharge frame body is expanded by high-temperature air rising from the fixing device. Therefore, the shaft portion is rotatably supported by the discharge frame body with a relatively large play in the width direction of the discharge port.

  The play prevents a member such as a bearing attached to the shaft portion from being caught by a part of the discharge frame deformed due to thermal expansion, and consequently prevents the rotation failure of the drive roller.

  However, when the play of the shaft portion in the width direction is large, the driving roller is displaced in the width direction during the conveyance of the sheet, and sheet conveyance defects such as skewing of the sheet and jamming of the sheet occur. There is a fear.

  In addition, when the double-sided printing process is performed, the drive roller rotates the reverse to convey the sheet to the reverse conveyance path. At this time, if the driving roller is displaced in the width direction, the position of the image on the front and back surfaces of the sheet is misaligned.

  An object of the present invention is to prevent the rotation of the drive roller in the width direction while preventing the rotation failure of the drive roller when the frame supporting the drive roller at the sheet discharge port can be deformed by thermal expansion. An object of the present invention is to provide a sheet discharge device capable of preventing the sheet conveyance failure caused by the failure.

  A sheet discharge apparatus according to one aspect of the present invention is an apparatus that discharges a sheet after image formation from a main body of the image forming apparatus in an electrophotographic image forming apparatus. The sheet discharge device includes a discharge frame, a discharge roller, a plurality of driven rollers, and a limiting unit. The discharge frame body is disposed above the fixing device in the main body portion of the image forming apparatus, and forms a discharge port to the outside of the main body portion of the sheet after passing through the fixing device. The drive roller includes a drive shaft portion rotatably supported by portions on both sides of the discharge port in the discharge frame body with play in a width direction of the discharge port, and a plurality of the drive rollers fixed to the drive shaft portion. And the drive shaft is rotated by being driven. The plurality of driven rollers have a plurality of driven roller bodies that are disposed at positions facing the plurality of driving roller bodies through the discharge port, and are individually supported so as to be rotatable about the driven shaft portions. . The restricting portion includes a restricting portion provided on the discharge frame body or the driven roller and a restricted portion provided on the discharge roller. The restricting portion limits the displacement of the discharge roller in the width direction to a range smaller than the play by contacting the restricted portion.

  According to the present invention, when the frame portion that supports the drive roller at the sheet discharge port can be deformed by thermal expansion, the rotation of the drive roller in the width direction is prevented while preventing the rotation failure of the drive roller. It is possible to provide a sheet discharge device that can prevent the sheet conveyance failure caused by the failure.

FIG. 1 is a perspective view of an image forming apparatus including a sheet discharging apparatus according to the first embodiment. FIG. 2 is a configuration diagram of the image forming apparatus including the sheet discharging apparatus according to the first embodiment. FIG. 3 is a perspective view of the sheet discharging apparatus according to the first embodiment. FIG. 4 is an exploded perspective view of the sheet discharging apparatus according to the first embodiment. FIG. 5 is a cross-sectional view of the support portion of the discharge rotator in the sheet discharge apparatus according to the first embodiment, FIG. 5A is a cross-sectional view of the support portion on the first end side of the discharge rotator, and FIG. It is sectional drawing of the support part by the side of the 2nd end of a rotary body. FIG. 6 is a front view of portions of the discharge roller and the driven roller in the sheet discharge apparatus according to the first embodiment. FIG. 7 is a front view of portions of the discharge roller and the driven roller in the sheet discharge apparatus according to the second embodiment. FIG. 8 is a perspective view of a portion of the discharge roller in the sheet discharge apparatus according to the third embodiment. FIG. 9 is a partially exploded perspective view of the sheet discharging apparatus according to the fourth embodiment. FIG. 10 is a perspective view of a pair of limiting portions in the sheet discharge apparatus according to the fourth embodiment.

  Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. In addition, the following embodiment is an example which actualized this invention, Comprising: It does not have the character which limits the technical scope of this invention.

First Embodiment: Configuration of Image Forming Apparatus 10
First, the configuration of the image forming apparatus 10 including the sheet discharging apparatus 6 according to the first embodiment will be described with reference to FIGS. The image forming apparatus 10 is an apparatus that forms an image on the sheet 9 by electrophotography. The sheet 9 is a sheet-like image forming medium such as paper and an envelope.

  As shown in FIGS. 1 and 2, the image forming apparatus 10 includes a sheet supply unit 2, a sheet conveyance unit 3, an image forming unit 40, an optical scanning unit 46, a fixing device 49, and a sheet discharge unit provided in the main body unit 1. The apparatus 6 etc. are provided.

  As shown in FIGS. 1 and 2, the sheet discharge device 6 is disposed on the upper portion of the main body 1 of the image forming apparatus 10, and the sheet 9 after image formation is transferred from the discharge port 1 x of the main body 1 to the upper portion of the main body 1. To the discharge tray 1y.

  In each figure, arrows representing coordinate axes indicate the vertical direction D0, the first horizontal direction D1, and the second horizontal direction D2 of the image forming apparatus 10 in a state where the image forming apparatus 10 is installed to be usable. The first lateral direction D1 is the width direction of the sheet discharge device 6. The second lateral direction D2 is a horizontal direction orthogonal to the first lateral direction D1.

  The image forming unit 40 executes an image forming process for forming a toner image on the sheet 9. The image forming unit 40 includes an image forming unit 4. The image forming unit 4 includes a drum-shaped photoreceptor 41, a charging unit 42, a developing device 43, a drum cleaning device 45, and the like.

  An image forming apparatus 10 shown in FIG. 2 is a tandem color image forming apparatus. Therefore, the image forming unit 40 includes a plurality of image forming units 4 corresponding to a plurality of color toners and an intermediate transfer unit 5.

  As shown in FIG. 2, the intermediate transfer unit 5 includes an intermediate transfer belt 51, a pair of belt support rollers 52, a belt cleaning device 53, and a plurality of belt transfer devices 54 corresponding to the plurality of image forming units 4. Is provided. The pair of belt support rollers 52 rotatably support the intermediate transfer belt 51.

  The image forming apparatus 10 includes four image forming units 4 and four belt transfer devices 54 corresponding to the toners of four colors of yellow, cyan, magenta, and black. The four image forming units 4 are arranged along the traveling direction of the lower surface of the intermediate transfer belt 51. The lower surface of the intermediate transfer belt 51 is a surface with which a plurality of photoconductors 41 are in contact.

  The sheet supply unit 2 sends the sheet 9 to the main conveyance path 30 in the main body 1, and the sheet conveyance unit 3 conveys the sheet 9 along the main conveyance path 30.

  The photoconductor 41 rotates and the charging unit 42 charges the surface of the photoconductor 41. Further, the optical scanning unit 46 writes an electrostatic latent image on the surface of the photoreceptor 41 by scanning with laser light.

  Further, the developing device 43 develops the electrostatic latent image as a toner image. Then, the belt transfer device 54 transfers the toner image on the surface of the photoreceptor 41 to the intermediate transfer belt 51.

  The color toner images are formed on the lower surface of the intermediate transfer belt 51 by transferring the toner images of a plurality of colors from the plurality of photoreceptors 41 to the intermediate transfer belt 51.

  The sheet transfer device 48 transfers the toner image formed on the intermediate transfer belt 51 to the sheet 9 being conveyed along the main conveyance path 30. The fixing device 49 fixes the toner image transferred to the sheet 9 to the sheet 9 by heating.

  The sheet 9 after image formation that has passed through the fixing device 49 is discharged to the discharge tray 1 y by the sheet discharge device 6. As shown in FIG. 2, the sheet discharge device 6 is disposed above the fixing device 49 in the main body 1.

  The belt cleaning device 53 removes the toner remaining in the portion of the intermediate transfer belt 51 that has passed through the sheet transfer device 48.

[Outline of Sheet Discharge Device 6]
As shown in FIGS. 3 and 4, the sheet discharge device 6 includes a discharge frame body 60, a drive roller 6x, a plurality of driven rotation mechanisms 6y, and the like.

  The discharge frame 60 is a synthetic resin member. The discharge frame 60 is disposed above the fixing device 49 in the main body 1 of the image forming apparatus 10. The discharge frame 60 forms a discharge port 1x to the outside of the main body 1 of the sheet 9 after passing through the fixing device 49. The width direction of the discharge port 1x corresponds to the first lateral direction D1.

  The drive roller 6 x has a metal rod-shaped shaft portion 62 and a plurality of drive roller bodies 61. The shaft portion 62 is rotatably supported by the two first support portions 601 in the discharge frame body 60. The two first support portions 601 are formed on both sides of the discharge port 1x in the discharge frame body 60. In the present embodiment, the two first support portions 601 are part of the upper frame portion 60a. The shaft portion 62 is an example of a drive shaft portion.

  In the present embodiment, the shaft portion 62 is supported by two first support portions 601 via two bearings 64 through which the shaft portion 62 penetrates. In a state where the shaft portion 62 is supported by the two first support portions 601, the longitudinal direction of the shaft portion 62 corresponds to the first lateral direction D1.

  Each of the plurality of drive roller bodies 61 is a cylindrical elastic member fixed to the shaft portion 62. For example, the drive roller body 61 is an elastomer member such as urethane rubber.

  In the present embodiment, the two drive roller bodies 61 are fixed to the shaft portion 62 with an interval in the first lateral direction D1. It is also conceivable that the sheet discharge device 6 includes three or more drive roller bodies 61.

  A gear 63 is attached to one end portion of the shaft portion 62, and a stop ring 65 is attached to the other end portion of the shaft portion 62. The connecting portion 63 a of the gear 63 is fixed to one end portion of the shaft portion 62. For example, one end portion of the shaft portion 62 is formed in a non-circular cross section, and the gear 63 is formed with a through hole through which one end portion of the shaft portion 62 passes. The inner shape of the through hole is a non-circular shape that follows the outer shape of one end of the shaft portion 62. Further, the connecting portion 63 a is provided with a lock mechanism such as a snap fit that engages with a recess formed in the shaft portion 62. The gear 63 and the stop ring 65 prevent the shaft portion 62 from being detached from the two first support portions 601.

  The gear 63 is rotationally driven by a gear mechanism (not shown) provided in the main body 1. The driving roller 6x rotates when the shaft portion 62 is driven via the gear 63.

  Each of the plurality of driven rotation mechanisms 6y includes a driven roller body 66 that is a hard member made of synthetic resin, a metal shaft portion 67, and a spring 68. The shaft portion 67 is an example of a driven shaft portion.

  The plurality of driven roller bodies 66 are arranged at positions facing each of the plurality of driving roller bodies 61 via the discharge port 1x, and are individually supported so as to be rotatable around the shaft portion 67. The driven roller body 66 and the shaft portion 67 constitute a driven roller 660. In this embodiment, each driven roller body 66 is formed integrally with a shaft portion 67, and the shaft portion 67 is rotatably supported by two second support portions 602.

  The plurality of second support portions 602 are a part of the discharge frame body 60. In the present embodiment, the plurality of second support portions 602 are a part of the lower frame portion 60b. The discharge frame body 60 has two second support portions 602 for each driven roller body 66.

  The plurality of springs 68 are provided corresponding to the plurality of driven roller bodies 66. Each spring 68 elastically urges each driven roller body 66 against each corresponding drive roller body 61. Each spring 68 is an example of an elastic member that biases each driven roller body 66 against each drive roller body 61.

  As shown in FIG. 4, the discharge frame body 60 in the present embodiment is a member in which an upper frame portion 60a and a lower frame portion 60b are combined. The drive roller 6x is supported by two first support portions 601 formed on the upper frame portion 60a, and the plurality of driven roller bodies 66 are respectively provided with a plurality of second support portions formed on the lower frame portion 60b. Supported by part 602.

  The plurality of driven roller bodies 66 are driven to rotate with the sheet 9 interposed between the plurality of driving roller bodies 61. When the driving roller 6x rotates in a predetermined forward direction, the plurality of driving roller bodies 61 and the plurality of driven roller bodies 66 feed the sheet 9 sandwiched between them into the main conveyance path 30 in the main body 1. To the discharge tray 1y.

  Further, when double-sided printing for forming images on both sides of the sheet 9 is performed, the driving roller 6x is arranged before the rear end of the sheet 9 sandwiched between the plurality of driven roller bodies 66 passes through the discharge port 1x. Reverse rotation in the opposite direction of the forward direction. Thereby, the plurality of driving roller bodies 61 and the plurality of driven roller bodies 66 convey the sheet 9 from the discharge port 1x to the reverse conveyance path 30a in the main body 1.

  As shown in FIG. 2, the reverse conveyance path 30 a is a path of the sheet 9 that connects the discharge port 1 x and the merging portion 30 b upstream of the image transfer position in the main conveyance path 30 in the sheet conveyance direction. The image transfer position is a position where the sheet transfer device 48 is disposed in the main conveyance path 30.

  By the way, when the sheet discharge device 6 is disposed above the fixing device 49, the synthetic resin discharge frame 60 is expanded by the high-temperature air rising from the fixing device 49. Therefore, as shown in FIGS. 5A and 5B, the shaft portion 62 of the drive roller 6x is rotated by the first support portion 601 of the discharge frame body 60 in a state having a relatively large play P0 in the first lateral direction D1. Supported as possible.

  As described above, the first lateral direction D1 corresponds to the width direction of the discharge port 1x and the longitudinal direction of the shaft portion 62. The first lateral direction D1 is also the width direction of the sheet 9 passing through the discharge port 1x.

  FIG. 5A shows that a play P0 is formed between the outer surface 601a of the first support portion 601 and the bearing 64 attached to the shaft portion 62 at one end portion of the shaft portion 62 of the driving roller 6x. Show. In the bearing 64 shown in FIG. 5A, relative movement with respect to the shaft portion 62 toward the one end side in the first lateral direction D <b> 1 is restricted by a stop ring 65 attached to the shaft portion 62.

  Similarly, in FIG. 5B, at the other end of the shaft portion 62 of the driving roller 6x, a play P0 is formed between the outer surface 601b of the first support portion 601 and the bearing 64 attached to the shaft portion 62. Indicates that The relative movement of the bearing 64 shown in FIG. 5B with respect to the shaft portion 62 toward the other end side in the first lateral direction D1 is restricted by the connecting portion 63a of the gear 63 fixed to the shaft portion 62 by the lock mechanism.

  The play P0 prevents a member such as the bearing 64 attached to the shaft portion 62 from rubbing against the two first support portions 601 where the distance in the first lateral direction D1 is increased due to the thermal expansion of the discharge frame body 60. As a result, the rotation failure of the drive roller body 61 is prevented.

  However, when the play of the shaft portion 62 in the first lateral direction D1 is large, the driving roller body 61 is displaced in the first lateral direction D1 while the sheet 9 is being conveyed, and the sheet 9 is skewed and the sheet 9 is jammed. There is a risk of poor conveyance.

  Further, when the double-sided printing process is performed, the driving roller body 61 conveys the sheet 9 to the reverse conveying path 30a by rotating in the reverse direction. At this time, if the driving roller body 61 is displaced in the first lateral direction D1, the position of the image on the front surface and the back surface of the sheet 9 is mismatched.

  In order to solve the above problem, the sheet discharge device 6 has a displacement limiting structure described later. Thereby, the sheet discharge device 6 prevents the rotation failure of the drive roller body 61 from occurring when the discharge frame body 60 that supports the drive roller body 61 can be deformed by thermal expansion at the discharge port 1x. It is possible to prevent sheet conveyance failure due to the displacement of the body 61 in the first lateral direction D1.

[Displacement limiting structure]
The displacement limiting structure in the sheet discharge apparatus 6 according to the first embodiment will be described with reference to FIG.

  The driving roller 6 x of the sheet discharge device 6 includes a pair of flange portions 7 fixed to both sides of the driving roller body 61. At least a pair of flange portions 7 are formed so as to protrude from both ends of one of the plurality of drive roller bodies 61 in the shaft portion 62.

  In the following description, among the plurality of drive roller bodies 61, one or more drive roller bodies 61 provided with a pair of flange portions 7 on both sides are referred to as first drive roller bodies 61x. Of the plurality of driven roller bodies 66, the one that faces the first drive roller body 61x is referred to as a first driven roller body 66x. It is also conceivable that all the driving roller bodies 61 are the first driving roller bodies 61x.

  The flange portion 7 is formed so as to protrude from the end portions on both sides of the first drive roller body 61x in the shaft portion 62 to a position facing the edge portions 66a on both sides of the first driven roller body 66x.

  The pair of flange portions 7 and the edge portions 66a on both sides of the first driven roller body 66x face each other in the first lateral direction D1. And the edge part 66a of the both sides of the 1st driven roller body 66x contact | abuts to a pair of flange part 7, and the displacement of the 1st horizontal direction D1 of the driving roller 6x is rather than the play P0 shown by FIG. Limit to a small range.

  That is, the sum of the distance in the first lateral direction D1 between the pair of flange portions 7 and the edge portions 66a on both sides of the first driven roller body 66x and the play in the first lateral direction D1 of the first driven roller body 66x. Is smaller than the play P0 of the driving roller 6x in the first lateral direction D1.

  The shaft portion 62 of the drive roller 6x is a member made of a metal such as iron. The discharge frame body 60 is a synthetic resin member, and has a higher thermal expansion coefficient than the shaft portion 62. And the length of the 1st horizontal direction D1 of the part covering the two 1st support parts 601 in the discharge frame 60 is long. Therefore, the extended length of the interval between the two first support portions 601 due to the thermal expansion of the discharge frame body 60 is larger than the extension length due to the thermal expansion of the shaft portion 62. Therefore, a relatively large play P0 is necessary.

  On the other hand, the driven roller 660 including the driven roller body 66 is a synthetic resin member, and the difference in thermal expansion coefficient between the driven roller 660 and the discharge frame body 60 is small. In addition, the length of the portion of the discharge frame 60 that extends over the two second support portions 602 and the driven roller 660 in the first lateral direction D1 is long. Therefore, the difference between the extended length of the interval between the two second support portions 602 due to the thermal expansion of the discharge frame 60 and the extended length due to the thermal expansion of the driven roller 660 is small. Therefore, the rotation failure of the first driven roller body 66x due to thermal expansion hardly occurs, and the play in the first lateral direction D1 of the first driven roller body 66x can be reduced.

  The pair of flange portions 7 and the edge portions 66 a on both sides of the first driven roller body 66 x constitute the displacement limiting structure in the sheet discharge device 6.

  In addition, the edge part 66a of the both sides of the 1st driven roller body 66x is an example of the control part provided in the driven roller 660. Moreover, a pair of flange part 7 is an example of the to-be-regulated part provided in the drive roller 6x. The pair of flange portions 7 and the edge portions 66a on both sides of the first driven roller body 66x are an example of a limiting portion. The pair of flange portions 7 is an example of a pair of first flange portions.

  If the sheet discharge device 6 is employed, even when the discharge frame body 60 is deformed in the first lateral direction D1 due to thermal expansion, the first rotation of the drive roller body 61 is prevented while preventing the rotation failure of the drive roller body 61. The displacement width in the lateral direction D1 can be reduced. As a result, it is possible to prevent sheet conveyance defects due to the displacement of the driving roller body 61 in the first lateral direction D1.

  Further, the sheet 9 is bent in a convex shape toward the first driving roller body 61x by the pair of flange portions 7 in a portion passing between the first driving roller body 61x and the first driven roller body 66x. As a result, the sheet 9 passing through the discharge port 1x toward the discharge tray 1y is less likely to hang down from the discharge port 1x onto the discharge tray 1y. As a result, it is possible to prevent the stacking failure of the sheets 9 on the discharge tray 1y.

  Moreover, the surface which opposes the edge part 66a of the both sides of the 1st driven roller body 66x in a pair of flange part 7 is the inclined surface 7a. These inclined surfaces 7a are formed so as to be inclined so that the protruding height from the inner side near the first driving roller body 61x toward the opposite outer side in the first lateral direction D1 toward the first driven roller body 66x increases. Has been. The inclined surfaces 7 a included in the pair of flange portions 7 are examples of side surfaces that spread outwardly from the end portions on both sides of the driving roller body 61.

  Moreover, the edge part 66a of the both sides of the 1st driven roller body 66x and the edge part 7b of the top part in a pair of flange part 7 are formed in the chamfering shape.

  The shape of the inclined surface 7a and the edge portions 66a and 7b prevents the pair of flange portions 7 from folding the sheet 9.

  In the sheet discharge device 6, it is conceivable that the pair of flange portions 7 are synthetic resin hard members. On the other hand, it is also conceivable that the pair of flange portions 7 are foamed members such as sponges. If a pair of flange part 7 is the said foaming member, it can prevent more reliably that a crease | fold will be formed in the sheet | seat 9. FIG.

[Second Embodiment]
Next, the displacement limiting structure in the sheet discharge apparatus 6A according to the second embodiment will be described with reference to FIG. 7, the same components as those shown in FIGS. 1 to 6 are given the same reference numerals.

  The sheet discharge device 6A is different from the sheet discharge device 6 only in the displacement limiting structure. Hereinafter, differences between the displacement limiting structure of the sheet discharging apparatus 6A and the displacement limiting structure of the sheet discharging apparatus 6 will be described.

  At least one of the plurality of driven roller bodies 66 in the sheet discharge device 6A is formed integrally with the pair of flange portions 7v. In the following description, of the plurality of driven roller bodies 66, one or more driven roller bodies 66 formed integrally with the pair of flange portions 7v are referred to as second driven roller bodies 66y.

  Further, among the plurality of driving roller bodies 61, the one facing the second driving roller body 61y is referred to as a second driving roller body 61y. It is also conceivable that all the driven roller bodies 66 are the second driven roller bodies 66y.

  The pair of flange portions 7v are formed to project from the end portions on both sides of the second driven roller body 66y to positions facing the edge portions 61a on both sides of the second drive roller body 61y.

  The pair of flange portions 7v and the edge portions 61a on both sides of the second drive roller body 61y face each other in the first lateral direction D1. And a pair of flange part 7v contact | abuts to the edge part 61a of the both sides of the 2nd drive roller body 61y, and the displacement of the 1st horizontal direction D1 of the drive roller 6x is rather than the play P0 shown by FIG. Limit to a small range.

  That is, the sum of the distance in the first lateral direction D1 between the pair of flange portions 7v and the edge portions 61a on both sides of the second drive roller body 61y and the play in the first lateral direction D1 of the second driven roller body 66y. Is smaller than the play P0 of the driving roller 6x in the first lateral direction D1.

  The pair of flange portions 7v and the edge portions 61a on both sides of the second drive roller body 61y constitute the displacement limiting structure in the sheet discharge device 6A.

  The pair of flange portions 7v is an example of a restriction portion provided on the driven roller 660. Further, the edge portions 61 a on both sides of the second drive roller body 61 y are an example of a regulated portion provided in the drive roller body 61. The pair of flange portions 7v and the edge portions 61a on both sides of the second drive roller body 61y are an example of a limiting portion. The pair of flange portions 7v is an example of a pair of second flange portions.

  If the sheet discharge device 6A is employed in the image forming apparatus 10, the same effects as those obtained when the sheet discharge device 6 is employed are obtained.

  Moreover, the surface which opposes the edge part 61a of the both sides of the 2nd drive roller body 61y in a pair of flange part 7v is the inclined surface 7c. The inclined surfaces 7c are formed so as to be inclined so that the protruding height from the inner side near the second driven roller body 66y toward the second outer side in the first lateral direction D1 toward the second driving roller body 61y increases. Has been. The inclined surfaces 7 a included in the pair of flange portions 7 v are an example of side surfaces that spread outwardly from the end portions on both sides of the driven roller body 66.

  Moreover, the edge part 61a of the both sides of the 2nd drive roller body 61y and the edge part 7d of the top part in a pair of flange part 7v are formed in the chamfering shape.

  The shape of the inclined surface 7 c and the edge portions 61 a and 7 d prevents the pair of flange portions 7 from folding the sheet 9.

  In the sheet discharge device 6A, it is conceivable that the pair of flange portions 7v are hard members made of synthetic resin. On the other hand, it is also conceivable that the pair of flange portions 7v are foamed members such as sponges. If the pair of flange portions 7v is the foam member, it is possible to more reliably prevent a crease from being formed in the sheet 9.

[Third Embodiment]
Next, the displacement limiting structure in the sheet discharge apparatus 6B according to the third embodiment will be described with reference to FIG. In FIG. 8, the same components as those shown in FIGS. 1 to 6 are denoted by the same reference numerals.

  The sheet discharge device 6B is different from the sheet discharge device 6 only in the displacement limiting structure. Hereinafter, differences between the displacement limiting structure of the sheet discharging apparatus 6B and the displacement limiting structure of the sheet discharging apparatus 6 will be described.

  In the following description, at least one of the plurality of drive roller bodies 61 constituting a part of the displacement limiting structure is referred to as a third drive roller body 61z.

  In the sheet discharge device 6B, at least a pair of restricting convex portions 7w corresponding to the third drive roller body 61z is formed on the discharge frame body 60. The pair of restricting convex portions 7w are portions that protrude to face both side surfaces 61c of the third drive roller body 61z at positions that do not interfere with the passage of the sheet 9.

  In the present embodiment, the upper frame portion 60 a of the discharge frame body 60 has a housing recess 603 that is a recess that houses a part of the drive roller body 61. The pair of regulating convex portions 7w are formed in the accommodating concave portion 603.

  The pair of restricting convex portions 7w are opposed to both side surfaces 61c of the third drive roller body 61z. The pair of restricting convex portions 7w abut on both side surfaces 61c of the third drive roller body 61z, so that the displacement of the drive roller 6x in the first lateral direction D1 is within a range smaller than the play P0 shown in FIGS. 5A and 5B. Restrict.

  That is, the distance in the first lateral direction D1 between the pair of restricting convex portions 7w and the both side surfaces 61c of the third drive roller body 61z is smaller than the play P0 in the first lateral direction D1 of the drive roller 6x.

  A pair of restricting convex portions 7w and both side surfaces 61c of the third drive roller body 61z constitute the displacement limiting structure in the sheet discharge device 6B.

  The pair of restricting convex portions 7w is an example of a restricting portion provided on the discharge frame body 60. Further, both side surfaces 61c of the third drive roller body 61z are an example of the regulated portion. Further, the pair of restricting convex portions 7w and the both side surfaces 61c of the third drive roller body 61z are an example of a limiting portion.

  If the sheet discharge device 6B is employed, even when the discharge frame body 60 is deformed in the first lateral direction D1 due to thermal expansion, the first rotation of the drive roller body 61 is prevented while preventing the rotation failure of the drive roller body 61. The displacement width in the lateral direction D1 can be reduced. As a result, it is possible to prevent sheet conveyance defects due to the displacement of the driving roller body 61 in the first lateral direction D1.

[Fourth Embodiment]
Next, the displacement limiting structure in the sheet discharging apparatus 6C according to the fourth embodiment will be described with reference to FIGS. 9 and 10, the same components as those shown in FIGS. 1 to 6 are given the same reference numerals.

  The sheet discharging apparatus 6C is different from the sheet discharging apparatus 6 only in the displacement limiting structure. Hereinafter, differences between the displacement limiting structure of the sheet discharging apparatus 6C and the displacement limiting structure of the sheet discharging apparatus 6 will be described.

  In the sheet discharging apparatus 6C, the shaft portion 62 of the driving roller 6x has a groove portion 7x formed over the entire circumference. In the example shown in FIG. 9, the groove portion 7x is formed at the center of the shaft portion 62 in the first lateral direction D1.

  Further, in the sheet discharge device 6C, the discharge frame body 60 has a regulation rib 7y that interferes with the inner surface of the groove 7x. The restriction rib 7 y is a portion provided to protrude from the discharge frame body 60 at a position where it does not interfere with the passage of the sheet 9. The regulation rib 7y has a facing surface 70y that faces the inner surface of the groove 7x.

  That is, the portion of the regulating rib 7y where the facing surface 70y is formed is inserted into the groove 7x. In the example shown in FIG. 10, the portion of the regulating rib 7y where the facing surface 70y is formed is formed in a groove shape in a range extending from the lower side of the groove portion 7x to both sides.

  The inner surface of the groove 7x and the facing surface 70y of the regulating rib 7y are opposed in the first lateral direction D1. As a result, the inner surface of the groove 7x and the opposing surface 70y of the regulating rib 7y limit the displacement of the drive roller 6x in the first lateral direction D1 to a range smaller than the play P0 shown in FIGS. 5A and 5B.

  That is, the distance in the first lateral direction D1 between the inner surface of the groove 7x and the opposing surface 70y of the regulating rib 7y is smaller than the play P0 in the first lateral direction D1 of the drive roller 6x.

  The inner surface of the groove portion 7x and the facing surface 70y of the regulation rib 7y constitute the displacement limiting structure in the sheet discharge device 6B.

  The restriction rib 7y is an example of a restriction portion provided on the discharge frame body 60. Further, the groove portion 7x of the shaft portion 62 is an example of a regulated portion provided in the drive roller 6x. Moreover, the groove part 7x and the regulation rib 7y are examples of a restriction part.

  If the sheet discharge device 6C is employed, even when the discharge frame body 60 is deformed in the first lateral direction D1 due to thermal expansion, the first rotation of the drive roller body 61 is prevented while preventing the rotation failure of the drive roller body 61. The displacement width in the lateral direction D1 can be reduced. As a result, it is possible to prevent sheet conveyance defects due to the displacement of the driving roller body 61 in the first lateral direction D1.

  Furthermore, the restriction rib 7y supports the central portion in the longitudinal direction of the shaft portion 62 from below when the shaft portion 62 is bent by gravity. Thereby, it can prevent that the axial part 62 deform | transforms greatly with gravity.

[Application example]
In the sheet discharging apparatus 6 </ b> C, it is conceivable that the groove portion 7 x is replaced with an on-axis flange portion fixed to the shaft portion 62. The axial flange portion is an annular member projecting from the shaft portion 62 over the entire circumference with an outer diameter smaller than that of the drive roller body 61.

  In this application example, the discharge frame 60 has portions facing both side surfaces of the axial flange portion. For example, it is conceivable that the discharge frame 60 has a pair of protrusions facing both side surfaces of the axial flange portion or a recess that accommodates a part of the axial flange portion.

  Even when this application example is adopted, the same effects as those obtained when the sheet discharge device 6C is adopted can be obtained.

  The sheet discharge device according to the present invention can be freely combined with the above-described embodiments and application examples, or can be appropriately modified within the scope of the inventions described in the claims. Alternatively, it may be configured by omitting a part.

1: Main unit 1x: Ejection port 1y: Ejection tray 2: Sheet feeding unit 3: Sheet conveying unit 4: Image forming unit 5: Intermediate transfer units 6, 6A, 6B, 6C: Sheet ejection device 6x: Drive roller 6y: Follower Rotating mechanism 7: flange portion (regulated portion, first flange portion)
7a: Flange portion inclined surface 7b: Flange portion edge portion 7c: Flange portion inclined surface 7d: Flange portion top edge portion 7v: Flange portion (regulator portion, second flange portion)
7w: Restriction convex part (regulation part)
7x: Groove (regulated part)
7y: Regulation rib (regulation section)
9: Sheet 10: Image forming apparatus 30: Main transport path 30a: Reverse transport path 30b: Merge section 40: Image forming section 41: Photoconductor 42: Charging section 43: Developing apparatus 45: Drum cleaning apparatus 46: Optical scanning section 48 : Sheet transfer device 49: fixing device 51: intermediate transfer belt 52: belt support roller 53: belt cleaning device 54: belt transfer device 60: discharge frame body 60a: upper frame portion 60b: lower frame portion 61: drive roller body 61a : Edges (regulated parts) on both sides of the first drive roller
61c: Both side surfaces of third driving roller (regulated portion)
61x: 1st drive roller 61y: 2nd drive roller 61z: 3rd drive roller 62: Shaft part (drive shaft part) of a drive roller
63: Gear 63a: Gear connecting portion 64: Bearing 65: Stop ring 66: Driven roller body 66a: Edges (regulators) on both sides of the first driven roller body
66x: 1st driven roller body 66y: 2nd driven roller body 67: Shaft part (driven shaft part) of driven roller
68: Spring 70y: Opposing surface 601: First support portion 601a: Outer surface 601b of the first support portion: Outer surface 602 of the first support portion: Second support portion 603: Housing recess 660: Driven roller D0: Vertical direction D1 : First lateral direction (width direction)
D2: Second lateral direction

Claims (11)

In the electrophotographic image forming apparatus, a sheet discharging apparatus that discharges a sheet after image formation from the main body of the image forming apparatus,
A discharge frame that is disposed above the fixing device in the main body portion of the image forming apparatus and that forms an outlet to the outside of the main body portion of the sheet after passing through the fixing device;
A drive shaft portion rotatably supported by portions on both sides of the discharge port in the discharge frame body with play in the width direction of the discharge port, and a plurality of drive roller bodies fixed to the drive shaft portion A drive roller that rotates when the drive shaft is driven;
A plurality of driven rollers having a plurality of driven roller bodies arranged at positions facing each of the plurality of driving roller bodies via the discharge port, and individually supported rotatably about a driven shaft portion;
A restricting portion having a restricting portion provided on the discharge frame or the driven roller and a restricted portion provided on the driving roller, and
The sheet discharge device, wherein the restricting portion limits the displacement of the driving roller in the width direction to a range smaller than the play by contacting the restricted portion. The regulated portion is provided in at least one of the plurality of driving roller bodies, and is a pair of protrusions formed to project from the end portions on both sides of the driving roller body to positions facing the edge portions on both sides of the driven roller. A first flange portion,
The sheet discharging apparatus according to claim 1, wherein the restriction portion is an edge portion on both sides of the driven roller body facing the drive roller body provided with the restricted portion.   The sheet discharging apparatus according to claim 2, wherein the pair of first flange portions have side surfaces that extend conically outward from end portions on both sides of the drive roller body.   The edge portions on both sides of the driven roller body facing the driving roller body provided with the regulated portion and the edge portions of the tops of the pair of first flange portions are formed in a chamfered shape. The sheet discharging apparatus according to claim 2 or 3.   The sheet discharging apparatus according to any one of claims 2 to 4, wherein the pair of first flange portions are foam members. The restricting portion is provided on at least one of the plurality of driven roller bodies, and is formed by a pair of first protrusions that extend from the end portions on both sides of the driven roller body to positions facing the edge portions on both sides of the drive roller body. 2 flanges,
The sheet discharging apparatus according to claim 1, wherein the regulated portion is an edge portion on both sides of the drive roller body facing the driven roller body provided with the pair of second flange portions.   The sheet discharging apparatus according to claim 6, wherein the plurality of second flange portions have side surfaces that spread outwardly from end portions on both sides of the driven roller body.   The sheet discharging apparatus according to claim 6 or 7, wherein edge portions on both sides of the drive roller body and top portions of the pair of second flange portions are formed in a chamfered shape.   The sheet discharging apparatus according to any one of claims 6 to 8, wherein the pair of second flange portions are foamed members. The discharge frame body has a housing recess for housing a part of the drive roller body,
The regulated portion is an end surface on both sides of the drive roller body, and the regulating portion is a pair of regulating convex portions that are formed in the housing recess and project opposite to the side surfaces on both sides of the drive roller body. The sheet discharging apparatus according to claim 1. The regulated portion is a groove portion formed over the entire circumference of the drive shaft portion,
The sheet discharge device according to claim 1, wherein the restriction portion is a restriction rib that protrudes from the discharge frame body at a position that does not interfere with the passage of the sheet and interferes with an inner surface of the groove portion.

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