JP6545019B2 - Sheet conveying apparatus and image forming apparatus - Google Patents

Description

  The present invention relates to a sheet conveying apparatus for conveying a sheet, and an image forming apparatus provided with the sheet conveying apparatus.

  An image forming apparatus for forming an image on a sheet such as a printer or a copier includes a sheet conveying apparatus for conveying a sheet. The sheet conveying apparatus has a conveying roller for conveying the sheet, but when foreign matter such as paper dust adheres to the conveying roller, the coefficient of friction of the outer peripheral surface of the conveying roller may be reduced, and the sheet may not be smoothly conveyed. .

  For this reason, the structure provided with the cleaning member which contacts the outer peripheral surface of a conveyance roller and cleans an outer peripheral surface is known conventionally (for example, refer patent document 1). Here, in order to secure the cleaning ability by the cleaning member, it is preferable to accurately maintain the positional relationship between the outer circumferential surface of the conveyance roller and the cleaning member. In the case of the configuration described in Patent Document 1, the positional relationship between the outer peripheral surface of the transfer roller and the cleaning member is accurately maintained by pressing the cleaning member supported by the frame against the outer peripheral surface of the transfer roller with a pressure spring. It is like that.

JP, 2008-156095, A

  Here, in order to maintain the cleaning ability of the cleaning member, it is preferable to periodically maintain the cleaning member. In maintenance of the cleaning member, for example, the cleaning member is removed from the apparatus and replaced, or foreign matter is removed and re-installed. In order to perform such maintenance of the cleaning member, it is preferable that at least the cleaning member can be easily removed from the apparatus. However, in the case of a configuration in which the cleaning member is pressed toward the transport roller, removing the cleaning member complicates the configuration.

  On the other hand, when the cleaning member is supported by the frame without pressure, the shaft portion of the conveyance roller is bent and the position of the conveyance roller is changed, the outer circumferential surface of the conveyance roller and the cleaning member It is difficult to maintain the positional relationship accurately. For example, when the conveyance roller conveys a high-rigidity sheet such as thick paper, the sheet abuts on the conveyance guide, and there is a possibility that the shaft may be bent due to the reaction force. Alternatively, the conveying roller forms a nip portion with the opposing roller to convey the sheet. In this case, the opposing roller is biased against the conveying roller, and the biasing force of the opposing roller The shaft may bend.

  In order to suppress such bending of the shaft portion of the conveyance roller, for example, it is conceivable to increase the support rigidity of the conveyance roller by increasing the diameter of the shaft portion or increasing the thickness of the frame. . However, in this case, the manufacturing cost of the device is increased.

  SUMMARY OF THE INVENTION In view of such circumstances, the present invention has an object to accurately maintain the positional relationship between the outer peripheral surface of a conveyance roller and a cleaning member with a low cost and simple configuration.

According to the present invention, a conveying roller for conveying a sheet, a cleaning member for cleaning the outer peripheral surface in contact with the outer peripheral surface of the conveying roller, and the cleaning member are held . The transport roller includes a holding member that is relatively rotatable, and a rotation restricting portion that restricts the removable holding member from rotating about the shaft, and the shaft of the conveyance roller has a small diameter portion. The holding member has an opening through which the small diameter portion can pass and the large diameter portion can not pass in the direction perpendicular to the axial direction of the transport roller. According to another aspect of the present invention, there is provided a sheet conveying apparatus characterized in that the sheet is formed and moved relative to the large diameter portion by moving along the axial direction of the conveyance roller .

  According to the present invention, the positional relationship between the outer peripheral surface of the transport roller and the cleaning member can be accurately maintained with low cost and a simple configuration.

FIG. 1 is a schematic sectional view of an image forming apparatus according to a first embodiment. FIG. 1 is a schematic cross-sectional view of a sheet conveying apparatus according to a first embodiment. FIG. 6A is a schematic configuration cross-sectional view showing (a) swinging of the swinging guide and (b) opening and closing of the first outer guide in the sheet conveying apparatus according to the first embodiment. (A) Sectional drawing of a periphery of the conveyance roller which concerns on 1st Embodiment. (B) The perspective view of the holder which similarly hold | maintained the cleaning member. (C) The perspective view of the conveyance roller which removed the holder similarly. (D) The perspective view of the 1st step which similarly assembles a holder to a conveyance roller. (E) Similarly a perspective view of the second stage. (F) A perspective view of the same third stage. (G) The figure which cut | disconnected one part and was seen from diagonally downward of (a). (A) Sectional drawing of a periphery of the conveyance roller which concerns on 2nd Embodiment. (B) The perspective view of the holder which similarly hold | maintained the cleaning member. (C) The perspective view of the conveyance roller which removed the holder similarly. (D) The perspective view which similarly shows the state which assemble | attaches a holder to a conveyance roller. (E) The figure which cut | disconnected one part and was seen from diagonally downward of (a).

First Embodiment
The first embodiment will be described using FIGS. 1 to 4. First, a schematic configuration of the image forming apparatus according to the present embodiment will be described with reference to FIG.

[Image forming apparatus]
The image forming apparatus 100 includes an apparatus main body 101 and a sheet feeding apparatus (paper deck) 102. A reader unit 21 having a scanning optical system for reading an image of a document is provided in the upper portion of the apparatus main body 101, and an image forming unit 1Y, 1M for forming a read image on a sheet under the reader unit 21. , 1C, 1K are provided. Further, on the lower side of the apparatus main body 101, there are provided a plurality of front loading type cassettes 61 to 64 which are accommodated so as to be accommodated in and removable from the front side of the apparatus. Further, on the right side of the apparatus main body 101 in the drawing, a sheet feeding apparatus 102 capable of stacking and feeding large-capacity sheets is connected.

  The image forming units 1Y, 1M, 1C, and 1K of each color of the apparatus main body 101 perform image formation based on image information sent from an external terminal such as a personal computer or image information read by the reader unit 21. For example, in the image forming unit 1Y that forms a yellow toner image, an electrostatic latent image is formed on the photosensitive drum 11Y whose surface is charged by the charging device 12Y by the scanner unit 13Y based on image information. The electrostatic latent image formed on the photosensitive drum 11Y is developed with yellow toner by the developing device 14Y, and a yellow toner image is formed on the photosensitive drum 11Y. The yellow toner image thus formed is transferred to the intermediate transfer belt 31 by the primary transfer portion 35Y. The toner remaining on the photosensitive drum 11Y after the transfer is removed by the cleaning device 15Y.

  Such an image forming process is similarly performed in the image forming unit 1M for forming a magenta toner image, the image forming unit 1C for forming a cyan toner image, and the image forming unit 1K for forming a black toner image. Then, the toner images of the respective colors are transferred onto the intermediate transfer belt 31 in an overlapping manner, and a full-color toner image is formed on the intermediate transfer belt 31.

  The toner image on the intermediate transfer belt 31 is conveyed to the secondary transfer portion 41 as the intermediate transfer belt 31 rotates. The toner image is transferred to the sheet S sent from the cassettes 61 to 64 or the sheet feeding device 102 at the secondary transfer portion 41. The sheet S on which the toner image has been transferred is conveyed by the conveyance belt 42 to the fixing device 5, and heat and pressure are applied by the fixing device 5 so that the toner image is fused to the sheet S.

  Thereafter, if the user's designation is in the single-sided image forming mode, the sheet S is discharged from the discharge port 50 to the outside of the apparatus. On the other hand, if the user's designation is in the double-sided image forming mode, the sheet S is reversed in the reverse path 51, is conveyed again to the secondary transfer portion 41 through the double-sided path 52, and the toner image Is formed.

  The sheet feeding apparatus 102 can feed the sheet S from the plurality of cassettes 201 to 203 to the apparatus main body 101 via the sheet conveyance path 200, respectively. A sheet conveying apparatus 300 for conveying the sheet S is provided on the downstream side of the sheet conveying path 200 in the conveying direction, and the sheet conveying apparatus 300 is connected to the apparatus main body 101 to feed the sheet S to the main body entrance roller 91 of the apparatus main body 101. Hand over. Then, the sheet S delivered to the main body inlet roller 91 is conveyed to the secondary transfer portion 41 as described above.

[Sheet conveying device]
Next, the sheet conveying apparatus 300 will be described with reference to FIGS. 2 to 4. First, a schematic configuration of the sheet conveying apparatus 300 will be described using FIGS. 2 and 3. FIG. 2 is a cross-sectional view orthogonal to the conveyance direction of the sheet conveyance device 300, and shows a conveyance path for delivering the sheet S fed from the sheet feeding device 102 to the main body inlet roller 91 of the device main body 101 of FIG. ing.

  The sheet S conveyed from the sheet conveyance path 200 is conveyed by the first conveyance roller pair 301 to the sheet conveyance device 300 via the curved guide pair 330 including the curved lower guide 331 and the curved upper guide 332. The sheet conveying apparatus 300 includes a second conveying roller pair 302, a conveying guide pair 310, and a swinging guide pair 320. Although described in detail later, the second conveyance roller pair 302 includes a conveyance roller 302A and an opposing roller 302B that forms a nip portion 302C that nips and conveys a sheet between the conveyance roller 302A. Then, the second conveyance roller pair 302 conveys the sheet conveyed from the curved guide pair 330 toward the conveyance guide pair 310 and the rocking guide pair 320. The swinging guide pair 320 is disposed at an angle α with respect to the conveyance guide pair 310. Thus, a bent conveyance path is formed in which the conveyance path of the sheet is bent.

  The swinging guide pair 320 is pivotable about a pivoting shaft 341 as shown in FIG. 3A. That is, the angle α (FIG. 2) with respect to the conveyance guide pair 310 can be changed. As a result, the swinging guide pair 320 rotates according to the difference in height when the apparatus main body 101 and the sheet feeding device 102 are installed, and the position of the downstream end of the swinging guide pair 320 in the conveying direction The smooth delivery of the sheet S is enabled according to the position of. For example, when the height of the receiving port of the apparatus main body 101 is low, the rocking guide pair 320 is rocked in the direction of the arrow C in FIG. 3A to adjust the height.

  Further, the conveyance guide pair 310 includes an outer guide 311 and an inner guide 312, and the rocking guide pair 320 includes a rocking outer guide 321 and a rocking inner guide 322. In addition, although the material of each guide of this embodiment is made into stainless steel, another material property may be sufficient. As shown in FIG. 3B, the door 340 including the outer guide 311, the opposing roller 302B, and the curved lower guide 331 is pivotable about the pivot shaft 342. Then, when a sheet jam or the like occurs in the transport path, the user can remove the sheet by rotating the door 340 in the direction of the arrow D in FIG. 3B.

  Here, the sheet S transported by the first transport roller pair 301 and the second transport roller pair 302 is sent to a bending transport path formed by the transport guide pair 310 and the swing guide pair 320. Then, when the rear end (upstream end) of the sheet S in the conveyance direction passes through the nip portion of the first conveyance roller pair 301, the sheet S is sent to the apparatus main body 101 only by the second conveyance roller pair 302. At this time, if the rigidity of the sheet S is high, foreign matter such as paper powder mainly composed of calcium carbonate or the like is formed on the outer peripheral surface (surface) of the conveyance roller 302A of the second conveyance roller pair 302 due to conveyance resistance from the bending conveyance path. It is easy to adhere. Therefore, as described below, the sheet conveying apparatus 300 according to the present embodiment includes the foreign matter removing apparatus 400 having the removing brush 402 as a cleaning member that cleans the outer peripheral surface of the conveying roller 302A.

Foreign substance removal device
The foreign matter removing device 400 will be described with reference to FIGS. 4 (a) to 4 (g). As described above, the second conveyance roller pair 302 includes the conveyance roller 302A and the opposing roller 302B. The conveying roller 302A is driven by a motor as a driving source (not shown), and the opposing roller 302B in contact with the conveying roller 302A rotates following the conveying roller 302A. The conveyance roller 302A is fixed to a conveyance roller shaft 303A as a shaft portion, and the opposing roller 302B is fixed to the opposing roller shaft 303B.

  The opposing roller 302B is biased toward the conveying roller 302A by a pressure spring 315 as a biasing member provided on the outer guide stay 317 fixed to the outer guide 311, as shown in FIG. 4 (g). There is. As a result, the opposing roller 302B is brought into contact with the transport roller 302A to form a nip portion 302C that nips and transports the sheet. As shown in FIG. 4G, a plurality (two in the present embodiment) of the conveying roller 302A and the opposing roller 302B are provided in the axial direction, respectively, and the nipping portions 302C are formed to face each other.

  As shown in FIG. 4A, on the opposite side of the outer peripheral surface of the conveyance roller 302A to the opposite roller 302B, a removal brush 402 as a cleaning member is disposed in contact with the outer peripheral surface of the conveyance roller 302A. The removal brush 402 is, for example, a brush made of acrylic and having a fiber length of about 10 mm planted, and is held by a removal holder 401 as a holding member.

  As shown in FIG. 4B, the removal holder 401 has a holding portion 410 for holding the removal brush 402, an attachment / detachment portion 411, a guide portion 412, and a swing support portion 413. The removal holder 401 is provided with a roller front guide 404 extended from the upstream side of the transport roller 302A toward the nip portion 302C. The roller front guide 404 guides the sheet conveyed from the upstream side to the second conveyance roller pair 302 to the nip portion 302C of the second conveyance roller pair 302.

  The detachable portions 411 are respectively integrally formed on both sides of the holding portion 410, and have three positioning portions 411A to 411C which are different in the circumferential direction. The positioning portions 411A and 411C are provided to face each other, and the positioning portion 411B is provided above the positioning portions 411A and 411C in an installed state. These positioning parts 411A-411C are each independently provided on the virtual surface of a substantially cylindrical surface, as shown to Fig.4 (a). In other words, connecting the positioning portions 411A to 411C results in a substantially cylindrical surface.

  Further, the mounting / demounting portion 411 is formed with an opening 411D through which the transport roller shaft 303A can pass and the bearing 405 described later can not pass in the direction orthogonal to the axial direction of the transport roller shaft 303A. The opening 411D is formed between the tips of the positioning portions 411A and 411C facing each other. Therefore, the distance between the ends of the positioning portions 411A and 411C is larger than the outer diameter of the conveyance roller shaft 303A and smaller than the outer diameter of the bearing 405.

  Thus, the distance between the pair of detachable portions 411 provided on both sides of the holding portion 410 is not less than the length (width) of the transport roller 302A in the axial direction by a predetermined slide amount of the removal holder 401 described later. large. Further, the diameter of the inscribed circle of the positioning portions 411A to 411C is larger than the outer diameter of the transport roller shaft 303A.

  The guide portions 412 are integrally formed on the outer side of the holding portion 410 more than the pair of attachment / detachment portions 411, and the inner circumferential surface has a substantially cylindrical shape. The cross-sectional shape of the inner peripheral surface is smaller than a semicircle, and the inner diameter thereof is the same as or slightly larger than the outer diameter of the conveying roller shaft 303A, and is inscribed in the positioning portions 411A to 411C of the detachable portion 411. Less than the diameter of the circle. The removal holder 401 is guided in the axial direction by the guide portion 412 contacting the transport roller shaft 303A.

  The swing support portion 413 is integrally formed upstream of the holding portion 410 in the sheet conveyance direction, as shown in FIG. 4A. The swing support portion 413 is formed to be bent so as to open upward in FIG. 4B, and provided therein so as to sandwich a rotation restricting shaft 403 described later, and supporting surfaces 413A and 413B substantially parallel to each other. Is provided. As shown in FIG. 4B, the swing support portion 413 enters the pair of positioning plate portions 316A, which will be described later, as shown in FIG. The engaging portions 413C engage with the side surfaces, respectively.

  Thus, the removal holder 401 holding the removal brush 402 is fixed so as to be relatively rotatable with respect to the transport roller shaft 303A of the transport roller 302A. For this purpose, as shown in FIG. 4C, a bearing 405 as a large diameter portion is provided at a position adjacent to the conveyance roller 302A of the conveyance roller shaft 303A. The bearing 405 is externally fitted and fixed to the conveyance roller shaft 303A in a state of being axially positioned with respect to the conveyance roller 302A through the spacer 406.

  Further, the bearing 405 has a cylindrical outer peripheral surface, the outer diameter is larger than the outer diameter of the conveying roller shaft 303A as a small diameter portion, and the diameter of the inscribed circle of the positioning portions 411A to 411C of the detachable portion 411. The same as or slightly larger than this diameter. The end portions of the positioning portions 411A and 411C facing each other are located on the opposite side of the removal brush 402 than the center of the bearing 405 as shown in FIG. 4A, and the distance between the end portions is the same as that of the bearing 405. It is smaller than the outer diameter.

  Thus, the detachable portion 411 is fixed to the conveying roller shaft 303A by contacting the outer peripheral surface of the bearing 405 at at least three points of the positioning portions 411A to 411C, and the bearing 405 to the conveying roller shaft 303A. Relative rotation is possible. Further, as described above, the diameter of the inscribed circle of the positioning portions 411A to 411C is larger than the outer diameter of the transport roller shaft 303A. Therefore, as described later, the attaching / detaching portion 411 moves the removing holder 401 along the axial direction between the position deviated from the bearing 405 and the bearing 405, whereby the conveying roller shaft 303A is moved through the bearing 405. It is removable with respect to.

  As shown in FIG. 4G, one bearing 405 is provided outside each of the two conveyance rollers 302A, and is not provided inside. FIG. 4C and FIGS. 4D to 4F described later show the conveyance roller 302A on the right side of FIG. 4G.

  Further, as shown in FIG. 4C, the inner guide stay 316 as a frame straddles the conveyance roller 302A in the conveyance direction on the inner guide 312 (guide member) on the conveyance roller 302A side of the conveyance guide pair 310. Provided in A pair of positioning plate portions 316A as positioning members are provided on the upstream side of the inner guide stay 316 relative to the conveying roller 302A so as to be orthogonal to the direction parallel to the axial direction of the conveying roller 302A. There is.

  The distance between the pair of positioning plate portions 316A is set slightly larger than the width of the swing support portion 413 of the removal holder 401 so that the swing support portion 413 can enter. Further, in the pair of positioning plate portions 316A, insertion holes 316B through which the rotation restricting shaft 403 as a rotation restricting portion can be inserted are respectively formed. The rotation restricting shaft 403 is detachably attached to the pair of positioning plate portions 316A. The support surfaces 413A and 413B of the swing support portion 413 contact the rotation restricting shaft 403 attached to the positioning plate portion 316A in a state where the engaging portion 413C is adjacent to the positioning plate portion 316A.

  Thus, the removal holder 401 is restricted from rotating about the transport roller shaft 303A. That is, when the conveyance roller 302A is rotationally driven, the removal holder 401 tries to rotate in the direction of arrow G in FIG. 4F due to the friction between the conveyance roller 302A and the removal brush 402. Further, the removing holder 401 is fixed to the conveying roller shaft 303A via the bearing 405 by the attaching / detaching portion 411 as described above. Therefore, when the conveying roller shaft 303A rotates with the conveying roller 302A, the removal holder 401 tends to rotate along with it. In the present embodiment, such rotation is restricted by the support surfaces 413A and 413B of the rocking support portion 413 coming into contact with the rotation restricting shaft 403.

  Further, in the case of the present embodiment, the removal holder 401 is swingably supported with respect to the inner guide stay 316 as a frame by the contact between the support surfaces 413A, 413B and the rotation restricting shaft 403. Further, the support surfaces 413A and 413B are formed substantially in parallel with the sheet conveyance direction by the conveyance roller pair 302. For this reason, the removal holder 401 is movably guided substantially parallel to the sheet conveyance direction by the contact between the support surfaces 413A and 413B and the rotation restricting shaft 403.

[Detachment of removal holder]
Next, attachment and detachment of the removal holder 401 will be described. First, as shown in FIG. 4D, the removal holder 401 is shifted in the direction of the arrow E (across the axial direction at a position where the mounting / demounting portion 411 deviates from the bearing 405 by a predetermined sliding amount in the axial direction opposite to the transport roller 302A. Assembly). At this time, the transport roller shaft 303A enters the mounting / dismounting portion 411 through the opening 411D, and the inner circumferential surface of the guide portion 412 contacts the outer circumferential surface of the transport roller shaft 303A. In FIG. 4D, since the bearing 405 is provided on the right side of the conveyance roller 302A, the removal holder 401 is assembled in a state of being shifted to the right. Under the present circumstances, since a bearing does not exist on the left side, the guide part 412 on the left side also contacts the outer peripheral surface of conveyance roller shaft 303A. Therefore, the guide portions 412 on both sides of the conveyance roller 302A contact the outer peripheral surface of the conveyance roller shaft 303A, and the removal holder 401 becomes movable along the conveyance roller shaft 303A.

  Next, when the removal holder 401 is moved along the axial direction in the direction of arrow F in FIG. 4 (e), the positioning portions 411A-C of the detachable portion 411 are externally fitted on the bearings 405, and the removal holder 401 is the transport roller. It is fixed rotatably relative to the shaft 303A.

  Next, when the removal holder 401 is rotated about the transport roller shaft 303A in the direction of arrow G in FIG. 4F, the swing support portion 413 of the removal holder 401 enters between the pair of positioning plate portions 316A. Do. Then, the engagement between the engaging portion 413C of the swing support portion 413 and the positioning plate portion 316A restricts the axial movement of the removal holder 401.

  Further, in this state, the rotation restricting shaft 403 is inserted into the insertion hole 316B of the positioning plate portion 316A. Thus, the rotation restricting shaft 403 enters between the support surfaces 413A and 413B of the swing support portion 413, and the removal holder 401 is restricted from rotating about the transport roller shaft 303A. At the same time, the removal holder 401 is swingably supported with respect to the inner guide stay 316, and can be moved substantially parallel to the sheet conveyance direction.

  When the removal holder 401 is removed, the above-described operation may be reversed. That is, the rotation restricting shaft 403 is removed from the positioning plate portion 316A, and the removal holder 401 is rotated in the direction opposite to the arrow G direction in FIG. 4 (f). Next, the removal holder 401 is moved in the direction opposite to the direction of the arrow F in FIG. Thereby, the removal holder 401 can be removed.

  As shown in FIG. 4 (g), the foreign matter removing device 400 can be attached symmetrically to the two conveying rollers 302A. Therefore, mounting and demounting of the removal holder 401 with respect to the conveyance roller 302A on the left side of FIG. 4G is possible by exchanging the right and the left in the above description.

  Further, the inner diameter of the two guide portions 412 is larger than that of the conveyance roller shaft 303A by the amount of misalignment (about several tens of μm). Then, even when the removal holder 401 tends to twist, the two guide portions 412 contact the transport roller shaft 303A centering on the mounting and demounting portion 411, the bearing 405, and the fixing portion, thereby restricting this twist.

  In the case of this embodiment, since the removal holder 401 holding the removal brush 402 is fixed so as to be rotatable relative to the transport roller shaft 303A, the positional relationship between the outer peripheral surface of the transport roller 302A and the removal brush 402 Can be accurately maintained. That is, even if the conveyance roller 302A bends and the position of the conveyance roller 302A changes, the removal holder 401 is fixed to the conveyance roller shaft 303A, so that the positional relationship between the removal brush 402 and the conveyance roller 302A is suppressed it can.

  Further, in the case of the present embodiment, the rotation restricting shaft 403 is brought into contact with the swing support portion 413 to restrict the rotation of the removal holder 401. Further, since the rotation restricting shaft 403 is in contact with the support surfaces 413A and 413B, the removal holder 401 is swingably supported with respect to the inner guide stay 316, and is movable substantially parallel to the sheet conveyance direction.

  Here, since the conveying roller 302A is biased by the opposing roller 302B, the conveying roller shaft 303A is bent in the biasing direction. Further, as described above, in the sheet conveying apparatus 300 according to the present embodiment, the bending conveying path is formed on the downstream side of the conveying roller pair 302. Therefore, for example, when a sheet having high rigidity such as thick paper is conveyed, the sheet may abut on the conveyance guide of the bending conveyance path, and the conveyance roller shaft 303A may be bent by receiving the reaction force.

  In the case of the present embodiment, the removal holder 401 is swingably supported with respect to the inner guide stay 316. Therefore, even if the conveying roller shaft 303A is bent by the urging of the opposing roller 302B and the conveying roller 302A is moved, the removing holder 401 can rock and maintain the positional relationship between the removing brush 402 and the conveying roller 302A. Further, the removal holder 401 is movable substantially parallel to the sheet conveyance direction. Therefore, even if the conveyance roller shaft 303A is bent by the reaction force of the sheet coming into contact with the conveyance guide and the conveyance roller 302A moves, the removal holder 401 moves in the conveyance direction of the sheet and the removal brush 402 and the conveyance roller 302A. Can maintain the positional relationship with As described above, in the case of the present embodiment, the removal brush 402 can be made to follow the transport roller 302A even if the transport roller shaft 303A is bent, and the positional relationship between the removal brush 402 and the outer peripheral surface of the transport roller 302A is maintained with high accuracy. it can.

  As a result, the removal brush 402 can more reliably clean the outer peripheral surface of the transport roller 302A. Further, the positional relationship between the removing brush 402 and the outer peripheral surface of the transport roller 302A can be maintained with high accuracy at low cost without increasing the rigidity of the transport roller 302A and the frame supporting the transport roller 302A.

  Further, in the case of the present embodiment, as described above, the removal holder 401 is fixed to the transport roller shaft 303A with a simple configuration, and the removal holder 401 and the portion supporting the removal holder 401 are pressurized. There is no such configuration. Therefore, as described above, the removal holder 401 can be easily attached and detached. If the removal holder 401 can be easily attached and detached, the maintainability such as replacement of the removal brush 402 can be improved.

  As described above, in the case of the present embodiment, the positional relationship between the outer circumferential surface of the transport roller 302A and the cleaning member can be accurately maintained with low cost and a simple configuration. In addition, the maintainability of the removal brush 402 is also improved.

Second Embodiment
The second embodiment will be described with reference to FIG. In the first embodiment described above, the removal holder 401 is fixed to the transport roller shaft 303A via the bearing 405. Thereby, the durability of the foreign matter removing device 400 can be enhanced, but the bearing 405 may be omitted if the durability is not required so much, such as periodically replacing the foreign matter removing device. For this reason, in the present embodiment, the foreign matter removing device 400A is directly fixed to the conveying roller shaft 303A without a bearing. The other configurations and functions are the same as those of the first embodiment, and therefore, the same symbols are given to the same configurations, and the description will be omitted or simplified, and the following description will be made focusing on parts different from the first embodiment. Do.

  As shown in FIGS. 5A and 5B, the removal holder 401A of the present embodiment has a holding portion 410, an attachment / detachment portion 411a, a guide portion 412, and a swing support portion 413a. The detachable portions 411a are integrally formed on both sides of the holding portion 410, and have three positioning portions 411aA to 411aC which are different in the circumferential direction. The positioning portions 411aA and 411aC are provided to face each other, and the positioning portions 411aB are provided above the positioning portions 411aA and 411aC in an installed state. As shown in FIGS. 5A and 5B, the positioning portions 411aA to 411aC are independently provided on the virtual surface of the substantially cylindrical surface. In other words, connecting the positioning portions 411aA to 411aC results in a substantially cylindrical surface.

  In addition, an opening 411aD is formed in which the mounting / demounting portion 411a can pass a groove 304 described later in a direction orthogonal to the axial direction of the transport roller shaft 303A and can not pass the transport roller shaft 303Aa as the shaft portion of the transport roller 302A. There is. The opening 411aD is formed between the tips of the positioning portions 411aA and 411aC facing each other. Therefore, the distance between the ends of the positioning portions 411aA and 411aC is smaller than the outer diameter of the conveying roller shaft 303Aa and larger than the outer diameter of the groove portion 304. Further, the diameter of the inscribed circle of the positioning portions 411aA to 411aC is larger than the outer diameter of the groove portion 304.

  As shown in FIG. 5A, the swing support portion 413a is integrally formed on the upstream side of the holding portion 410 in the sheet conveying direction. A support surface 413b is provided on the lower surface of the swing support portion 413a in FIG. 5B so as to abut on a protrusion member 316C described later. As shown in FIG. 5 (b), the swing support portion 413a enters the pair of positioning plate portions 316A and the inner side surfaces of the pair of positioning plate portions 316A, as shown in FIG. The engaging portions 413C engage with each other.

  Thus, the removal holder 401A holding the removal brush 402 is fixed so as to be relatively rotatable with respect to the transport roller shaft 303Aa of the transport roller 302A. For this purpose, as shown in FIG. 5C, the small diameter portion of the outer peripheral surface of the conveying roller shaft 303Aa is smaller than the other portion at a position away from the conveying roller 302A by a predetermined distance in the axial direction. The groove portion 304 is formed as

  Is the outer diameter of the transfer roller shaft 303Aa including the portion 305 (large diameter portion) between the transfer roller 302A of the transfer roller shaft 303Aa and the groove portion 304 the same as the diameter of the inscribed circle of the positioning portions 411aA to 411aC of the detachable portion 411a? , Slightly larger than this diameter. The end portions of the positioning portions 411aA and 411aC facing each other are located on the opposite side of the removal brush 402 with respect to the center of the conveyance roller shaft 303Aa, as shown in FIGS. 5 (a) and 5 (b). The interval is smaller than the outer diameter of the transport roller shaft 303Aa.

  Thereby, the attachment / detachment part 411a contacts at least three points of the positioning parts 411aA to 411aC with respect to the outer peripheral surface of the portion 305 between the conveyance roller shafts 303Aa. The attachment / detachment portion 411a is fixed to the transport roller shaft 303Aa, and can be relatively rotated with respect to the transport roller shaft 303Aa by rubbing. Further, as described above, the diameter of the inscribed circle of the positioning portions 411aA to 411aC is larger than the outer diameter of the groove portion 304. Therefore, as described later, the detachable portion 411a is detachable from the transport roller shaft 303Aa by moving the removal holder 401 along the axial direction between the groove portion 304 and the space portion 305.

  Further, as shown in FIG. 5C, on the upstream side of the inner guide stay 316 relative to the conveying roller 302A, a pair of positioning plate portions 316A as positioning members is in a direction parallel to the axial direction of the conveying roller 302A. It is provided to be orthogonal to. Further, a plate-like protruding member 316C as a rotation restricting portion is provided so as to protrude from a portion between the pair of positioning plate portions 316A of the inner guide stay 316. The support surface 413b of the swing support portion 413a contacts the tip of the projecting member 316C in a state where the engaging portion 413C is adjacent to the positioning plate portion 316A. Thus, the removal holder 401 is restricted from rotating about the transport roller shaft 303Aa.

  Further, in the case of the present embodiment, the removal holder 401 is supported swingably with respect to the inner guide stay 316 as a frame by the contact between the support surface 413 b and the tip of the projecting member 316 C. Further, the support surface 413 b is formed substantially parallel to the sheet conveyance direction by the conveyance roller pair 302. For this reason, the removal holder 401 is guided so as to be movable substantially parallel to the sheet conveyance direction by the contact between the support surface 413 b and the leading end of the projecting member 316 C.

  The attachment and detachment of the removal holder 401 will be described. First, as shown in FIG. 5D, the arrow E is at a position where the removal holder 401 is aligned with the groove portion 304 deviated by a predetermined sliding amount in the axial direction opposite to the conveying roller 302A from the gap portion 305a. Assemble in the direction (direction orthogonal to the axial direction). At this time, the groove 304 enters into the attachment / detachment section 411a through the opening 411aD, and the inner circumferential surface of the guide section 412 contacts the outer circumferential surface of the transport roller shaft 303Aa.

  Next, when the removal holder 401 is moved in the direction of the arrow F along the axial direction, the positioning portions 411aA to aC of the detachable portion 411a are externally fitted to the gap 305, and the removal holder 401 with respect to the transport roller shaft 303Aa It is fixed to be relatively rotatable.

  Next, when the removal holder 401 is rotated in the direction of arrow G about the transport roller shaft 303Aa, the swing support portion 413a of the removal holder 401 enters between the pair of positioning plate portions 316A. Then, the movement of the removal holder 401 in the axial direction is restricted by the engagement between the engagement portion 413C of the swing support portion 413a and the positioning plate portion 316A.

  Furthermore, in this state, the support surface 413b of the swing support portion 413a abuts on the tip end of the projecting member 316C. Here, when the conveyance roller 302A is rotationally driven, the removal holder 401A tries to rotate in the direction of arrow G in FIG. 5 (d). For this reason, when the support surface 413b abuts on the tip end portion of the projecting member 316C, the removal holder 401 is restricted from rotating about the transport roller shaft 303Aa. At the same time, the removal holder 401 is swingably supported with respect to the inner guide stay 316, and can be moved substantially parallel to the sheet conveyance direction.

  Also in this embodiment, the removal brush 402 can be made to follow the transport roller 302A even if the transport roller shaft 303Aa is bent, and the positional relationship between the removal brush 402 and the outer peripheral surface of the transport roller 302A is made highly accurate. It can be maintained. Further, as described above, the removal holder 401 can be easily attached and detached. If the removal holder 401 can be easily attached and detached, the maintainability such as replacement of the removal brush 402 can be improved.

Other Embodiments
In each of the above-described embodiments, an acrylic brush is used as the cleaning member. However, the cleaning member is not limited thereto, and any net-like fiber or foam can be used if foreign matter such as paper powder can be removed. I don't care.

  Further, the detachable portion is fixed to the conveying roller shaft directly or in contact with the bearing at three points, but the number of contact points may be three or more, and for example, the inner periphery of the detachable portion may be a cylindrical surface.

  1Y, 1M, 1C, 1K ... image forming unit / 300 ... sheet conveying device / 302A ... conveying roller / 302B ... opposing roller / 302C ... nip portion / 303A ... conveying roller shaft (Shaft portion, small diameter portion) / 303Aa ··· Transport roller shaft (shaft portion) / 304 · · · · Groove portion (small diameter portion) / 305 · · · · · · · · · · · · · · · · · · · · Guide inside member) / 315 ... pressing spring (biasing member) / 316 ... within the guide stay (frames) / 316A ... positioning plate portions (positioning member) / 316C ... projecting member / 400 and 400a · · · Foreign substance removal device / 401, 401 A · · · · · · removal holder (holding member) / 402 · · · removal brush (cleaning member) / 403 · · · rotation restriction shaft (rotation restriction portion, restriction shaft) / 405 · · · Bearing (large diameter part) / 410 ... Holding part / 411, 411a ... mounting part / 411D, 411aD ... opening / 412 ... guiding part / 413, 413a ... rocking supporting part / 413C ... engaging part / S ... Sheet

Claims (12)

A conveyance roller for conveying the sheet;
A cleaning member that contacts the outer peripheral surface of the transport roller to clean the outer peripheral surface;
Holds the cleaning member, with respect to the shaft portion of the conveying roller, relatively rotatably provided, and the holding member detachable,
E Bei and a rotation regulating portion for regulating said holding member is rotated around the shaft portion,
The shaft portion of the conveyance roller has a small diameter portion and a large diameter portion having an outer diameter larger than that of the small diameter portion.
The holding member is formed with an opening through which the small diameter portion can pass and the large diameter portion can not pass in the direction orthogonal to the axial direction of the conveyance roller, and is moved along the axial direction of the conveyance roller. Positioned relative to the large diameter portion,
Sheet conveying apparatus characterized in that. The holding member further includes a detachable portion positioned with respect to the large diameter portion,
The small diameter portion is a shaft portion of the transport roller,
The large diameter portion is a bearing provided at a position adjacent to the transport roller of the shaft portion of the transport roller,
The attachment / detachment portion is positioned on the bearing by being in contact with the outer circumferential surface of the bearing at at least three different circumferential points.
Characterized in that, the sheet conveying device according to claim 1. The holding member further includes a detachable portion positioned with respect to the large diameter portion,
The small diameter portion is a groove portion in which the outer diameter of the outer peripheral surface of the shaft portion of the conveyance roller is smaller than the other portion,
The large diameter portion is a portion of the shaft portion of the transport roller between the transport roller and the groove portion,
The attachment / detachment portion is positioned at the inter-portion by being in contact with the outer peripheral surface of the inter-portion at at least three different circumferential points.
Characterized in that, the sheet conveying device according to claim 1. The holding member has a guide portion which contacts the shaft portion of the conveyance roller to guide the holding member in the axial direction of the conveyance roller.
The sheet conveying apparatus according to any one of claims 1 to 3 , characterized in that: It has a frame provided with the rotation restricting portion,
The holding member has a swing support portion in contact with the rotation restricting portion to swingably support the holding member with respect to the frame.
The sheet conveying apparatus according to any one of claims 1 to 4 , characterized in that: The swing support portion contacts the rotation restricting portion to guide the holding member so as to be movable substantially parallel to the sheet conveyance direction.
The sheet conveying apparatus according to claim 5 , wherein The frame has a positioning member provided orthogonal to a direction parallel to the axial direction of the transport roller,
The holding member has an engaging portion which engages with the positioning member to restrict the holding member from moving in parallel with the axial direction of the transport roller.
The sheet conveying apparatus according to claim 5 or 6 , wherein The rotation restricting portion is a restricting shaft that is detachable with respect to the positioning member,
The rocking support portion is in contact with a restricting shaft mounted on the positioning member in a state where the engagement portion is adjacent to the positioning member.
The sheet conveying apparatus according to claim 7 , characterized in that: The rotation restricting portion is a projecting member provided to protrude from the frame,
The rocking support portion contacts the projecting member in a state where the engagement portion is adjacent to the positioning member.
The sheet conveying apparatus according to claim 7 , characterized in that: A guide member for guiding a sheet conveyed by the conveyance roller;
The frame is provided on the guide member.
The sheet conveying apparatus according to any one of claims 5 to 9 , characterized in that: An opposing roller that forms a nip portion that nips and conveys a sheet with the conveying roller;
And a biasing member for biasing the opposing roller toward the transport roller.
Characterized in that, the sheet conveying device according to any one of claims 1 to 1 0. A sheet conveying apparatus according to any one of claims 1 to 11.
An image forming unit configured to form an image on a sheet conveyed by the sheet conveyance device;
An image forming apparatus characterized by

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