JP2017198859A - Cleaning device and imaging forming apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image forming apparatus capable of suppressing the accumulation of toner on the upstream side of a screw member in the conveyance direction of the toner and to provide a cleaning device used for the image forming apparatus.SOLUTION: A cleaning device 51 includes a cleaning member 513, a screw member 514, and a toner receiving part 518. The cleaning member 513 removes the toner from a second roller 512 being a member to be cleaned. The screw member 514 conveys the toner removed by the cleaning member 513 along a predetermined conveyance direction. The toner receiving part 518 is provided on a toner drop path from the cleaning member 513 to the upstream side end of the screw member 514 in the conveyance direction of the toner in such a state that one end 518A energizes the surface of the screw member 514. The one end 518A is rocked with the rotation of the screw member 514.SELECTED DRAWING: Figure 2

Description

  The present invention relates to an electrophotographic image forming apparatus and a cleaning apparatus used therefor.

  For example, in a color electrophotographic image forming apparatus, a toner image is transferred from a plurality of photosensitive members corresponding to a plurality of colors to an intermediate transfer belt, and then the toner image is transferred from the intermediate transfer belt to a sheet. The Also, this type of image forming apparatus is provided with a cleaning device that removes toner remaining on the surface of the intermediate transfer belt. Specifically, the cleaning device includes a roller member that removes toner from the intermediate transfer belt, a cleaning member that removes toner from the roller member, and a screw member that conveys the removed toner toward a predetermined discharge port. It is done. In addition, the structure which provides a level | step difference in the bearing of a screw member is known as related technology (for example, refer patent document 1).

JP 2004-353664 A

  By the way, in the cleaning device as described above, on the downstream side in the toner conveyance direction by the screw member, the toner conveyance force is strengthened by the propulsion force from the toner conveyed from the upstream side in the toner conveyance direction. However, on the upstream side in the toner conveyance direction by the screw member, since the propulsive force from the toner conveyed from the upstream side in the toner conveyance direction is not received, the toner conveyance force becomes weak. In addition, a minute gap is generated between the rotating shaft of the screw member and the bearing. Therefore, for example, when a large amount of toner scraped off by the cleaning member flows into the upstream of the screw member in the toner transport direction, the toner accumulates without being transported downstream in the toner transport direction, There is a possibility that the toner may enter the gap between the end of the screw member rotating shaft in the toner conveyance direction and the bearing. In this case, the toner is melted and fixed by frictional heat between the rotating shaft and the bearing of the screw member, and the rotation of the screw member may be restricted.

  An object of the present invention is to provide an image forming apparatus capable of suppressing toner accumulation on the upstream side in the toner conveying direction of a screw member, and a cleaning device used therefor.

  A cleaning device according to one aspect of the present invention includes a cleaning member, a screw member, and a toner receiving portion. The cleaning member removes toner from the member to be cleaned. The screw member conveys the toner removed by the cleaning member along a predetermined conveyance direction. The toner receiving portion is provided on a toner dropping path from the cleaning member to an upstream end portion in the transport direction of the screw member, with one end portion biasing the surface of the screw member, As the member rotates, the one end swings.

  An image forming apparatus according to another aspect of the present invention includes the member to be cleaned and the cleaning device.

  According to the present invention, it is possible to provide an image forming apparatus capable of suppressing toner accumulation on the upstream side of the screw member in the toner conveyance direction, and a cleaning device used therefor.

FIG. 1 is a configuration diagram of an image forming apparatus according to an embodiment. FIG. 2 is a schematic diagram illustrating a part of the cleaning device in the image forming apparatus according to the embodiment. FIG. 3 is a schematic diagram illustrating a state transition of the toner receiver in the cleaning device in the image forming apparatus according to the embodiment. FIG. 4 is a schematic diagram illustrating a state transition of the toner receiver in the cleaning device in the image forming apparatus according to the embodiment. FIG. 5 is a schematic diagram illustrating a state transition of the toner receiver in the cleaning device in the image forming apparatus according to the 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.

  As shown in FIG. 1, the image forming apparatus 10 according to the present embodiment includes a plurality of image forming units 1 to 4, an intermediate transfer belt 5, a cleaning device 51, an optical scanning device 6, a secondary transfer device 7, and a fixing device. 8, a color printer including a paper discharge tray 9, a paper feed cassette 21, a transport path 22, and the like.

  The image forming apparatus 10 can form a monochrome image or a color image on a sheet such as paper based on input image data. The image forming apparatus according to the present invention may be, for example, a facsimile machine, a copier, or a multifunction machine.

  Each of the image forming units 1 to 4 is an electrophotographic image forming unit including a photosensitive drum (image carrier), a charging device, a developing device, a primary transfer device, and a drum cleaning device. The image forming units 1 to 4 are juxtaposed along the traveling direction of the intermediate transfer belt 5 and constitute a so-called tandem image forming unit. Each of the image forming units 1 to 4 is supplied with toner (developer) of each color from each of the toner containers 11 to 14.

  The intermediate transfer belt 5 travels along a predetermined direction while being stretched by a plurality of roller members, and the toner images of the respective colors formed on the photosensitive drums of the image forming units 1 to 4 are superimposed. It is an intermediate transfer member that is transferred together. The toner image formed on the intermediate transfer belt 5 is transferred to the sheet supplied from the paper feed cassette 21 by the secondary transfer device 7 and melted and fixed to the sheet by the fixing device 8.

  The cleaning device 51 can remove the toner remaining on the intermediate transfer belt 5, and includes a first roller 511, a second roller 512, a cleaning member 513, and a screw member 514. The first roller 511, the second roller 512, the cleaning member 513, and the screw member 514 are elongated in the same direction. In addition, the 1st roller 511, the 2nd roller 512, and the cleaning member 513 may be divided | segmented into multiple in the longitudinal direction.

  The cleaning device 51 is also provided with a drive transmission mechanism such as a gear that transmits a driving force from a predetermined driving motor to the first roller 511, the second roller 512, and the screw member 514. For example, the predetermined drive motor is driven at least while the intermediate transfer belt 5 is running, and may also serve as a belt motor that drives a drive roller that runs the intermediate transfer belt 5. In the image forming apparatus 10, the control device that controls the image forming apparatus 10 continues to drive the intermediate transfer belt 5 and the predetermined drive motor for a predetermined period after the transfer of the toner image from the intermediate transfer belt 5 to the sheet. The cleaning process for removing the toner remaining on the intermediate transfer belt 5 is executed.

  The first roller 511 is disposed in contact with the surface of the intermediate transfer belt 5, and is rotated in the counter direction with respect to the traveling direction of the intermediate transfer belt 5 by the predetermined drive motor. For example, a fur brush to be removed. The first roller 511 is a long member having a width equal to or larger than an image forming region to which a toner image is transferred at least on the surface of the intermediate transfer belt 5.

  The second roller 512 rotates in the direction opposite to the first roller 511 with respect to the rotation axis while contacting the surface of the first roller 511, and removes the toner from the first roller 511. For example, in FIG. 1, the first roller 511 rotates counterclockwise, and the second roller 512 rotates clockwise. In the present embodiment, the second roller 512 is an example of a member to be cleaned.

  The cleaning member 513 is disposed so as to come into contact with the surface of the second roller 512 from the downstream counter direction of the rotation direction of the second roller 512 at the contact position of the first roller 511 and the second roller 512, and the second roller 512. This is a blade-like member that removes toner from the surface.

  The screw member 514 transports the toner removed by the cleaning member 513 along a predetermined transport direction D1 (see FIG. 2) from one end portion in the axial direction (depth direction in FIG. 1) to the other end portion. The toner conveyed by the screw member 514 falls from a not-shown opening provided at the other end in the axial direction to the waste toner storage unit and is stored in the waste toner storage unit.

  By the way, in the cleaning device 51, on the downstream side of the toner conveyance direction D1 by the screw member 514, the toner conveyance force is increased by the propulsion force from the toner conveyed from the upstream side of the toner conveyance direction D1. However, on the upstream side of the toner conveyance direction D1 by the screw member 514, the propelling force from the toner conveyed from the upstream side of the toner conveyance direction D1 is not received, so the toner conveyance force becomes weak. On the other hand, a minute gap is generated between the rotating shaft of the screw member 514 and a bearing that rotatably supports the rotating shaft. Therefore, for example, when a large amount of toner scraped off by the cleaning member 513 flows into the upstream side of the screw conveyance direction D1 of the screw member 514, the toner is not conveyed downstream of the toner conveyance direction D1. And the toner may enter the gap between the upstream end portion of the rotating shaft of the screw member 514 in the toner conveyance direction D1 and the bearing. In this case, the toner is melted and fixed by frictional heat between the rotating shaft of the screw member 514 and the bearing, and the rotation of the screw member 514 may be restricted.

  On the other hand, in the image forming apparatus 10 and the cleaning apparatus 51, it is possible to suppress toner accumulation on the upstream side of the screw conveyance direction D1 of the screw member 514. Hereinafter, a configuration for suppressing toner accumulation will be described with reference to FIGS. FIG. 2 is a schematic diagram showing one end portion of the cleaning device 51. In FIG. 2, a state where the second roller 512 and the cleaning member 513 are removed is shown, and a connecting portion 512 </ b> A connected to the rotation shaft of the second roller 512 is shown.

  As shown in FIGS. 2 to 5, the cleaning device 51 includes a bearing 515, a support portion 516, a drive shaft 517, and a toner receiving portion 518. The bearing 515 is supported by a support portion 516, and supports one end portion of the screw member 514 so as to be rotatable. Similarly, the other end of the screw member 514 is rotatably supported by a bearing (not shown). The screw member 514 has one end connected to the drive shaft 517, and rotates when the drive shaft 517 is driven by a predetermined drive motor.

  A series of spiral protrusions 514A are provided on the surface of the screw member 514. When the screw member 514 rotates, the spiral protrusion 514A causes the screw member 514 to move in the transport direction D1 from one end to the other end. Toner is conveyed along. Note that a plurality of blade portions may be intermittently formed on the screw member 514 instead of the protruding portions 514A.

  The toner receiving portion 518 is disposed so as to correspond to the upstream end portion of the screw member 514 in the transport direction D1. Further, the toner receiving portion 518 is disposed on a toner dropping path that is scraped off from the second roller 512 by the cleaning member 513 and falls from the cleaning member 513 to the screw member 514.

  Specifically, the toner receiving portion 518 is an L-shaped film member in which one end portion 518A is a free end and the other end portion 518B is fixed to the upper surface of the support portion 516 using an adhesive or a screw. For example, the toner receiving portion 518 is molded from ultrahigh molecular weight polyethylene that has high slidability and excellent wear resistance. The material of the toner receiving portion 518 is not limited to ultrahigh molecular weight polyethylene, and may be other resin materials such as PET (polyethylene terephthalate) resin.

  The toner receiving portion 518 has elasticity, and the one end portion 518A and the other end portion 518B have an opening degree larger than 90 ° and smaller than 180 °, and the one end portion 518A is the screw member 514. It is arranged in a state in which the surface is urged in contact with the surface. More specifically, the inclination angle of the one end portion 518A of the toner receiving portion 518 with respect to the vertical direction is greater than 0 ° and smaller than 90 °.

  Therefore, a part of the toner scraped off from the second roller 512 by the cleaning member 513 slides down from the toner receiving part 518 toward the screw member 514, but the remaining part remains on the toner receiving part 518. become. That is, at the upstream end in the conveying direction D1 of the screw member 514, a part of the toner falling toward the screw member 514 is temporarily blocked by the toner receiving portion 518.

  The toner receiving portion 518 is a member bent from the other end portion 518B fixed on the support portion 516 toward the one end portion 518A so that the angle therebetween is 90 ° or more. It includes a flat portion from the portion 518B to the bent portion, and an inclined portion from the flat portion toward the one end portion 518A. Here, the toner receiving portion 518 is configured such that the flat portion does not exist inside the image forming area of the intermediate transfer belt 5.

  Further, the position of the one end 518A of the toner receiving portion 518 is a one-cycle spiral projection formed at the most upstream end in the toner conveying direction D1 of the screw member 514 in the axial direction of the screw member 514. It exists in the range of 514A.

  As a result, the toner receiving portion 518 swings in the direction perpendicular to the axial direction of the screw member 514 and in the biasing direction of the screw member 514 by the toner receiving portion 518 as the screw member 514 rotates.

  Hereinafter, the state transition of the toner receiving portion 518 accompanying the rotation of the screw member 514 will be described with reference to FIGS. 3 to 5 are schematic diagrams for explaining the positional relationship between the screw member 514 and the toner receiving portion 518, and the screw member 514 is viewed from a direction perpendicular to the longitudinal direction of the screw member 514. The state is shown.

  Specifically, in the state shown in FIG. 3, one end portion 518A of the toner receiving portion 518 rides on the protruding portion 514A of the screw member 514 and is lifted from the shaft portion of the screw member 514.

  Thereafter, when the screw member 514 rotates, as shown in FIG. 4, the toner receiving portion 518 has one end portion 518 </ b> A falling from the projection 514 </ b> A of the screw member 514 toward the shaft portion, Transition to the touched state.

  When the screw member 514 further rotates, as shown in FIG. 5, the toner receiving portion 518 is gradually lifted from the shaft portion of the screw member 514 with one end portion 518A being pushed up by the projection 514A of the screw member 514. It will be. That is, the one end portion 518A of the toner receiving portion 518 is gradually separated from the shaft portion of the screw member 514.

  As described above, the one end portion 518A of the toner receiving portion 518 swings in a direction in which the one end portion 518A comes into contact with or separates from the shaft portion of the screw member 514 as the screw member 514 rotates. Accordingly, the toner falling on the toner receiving portion 518 gradually drops from the toner receiving portion 518 toward the screw member 514 due to vibration generated by the swing of the one end portion 518A of the toner receiving portion 518. Accordingly, in the cleaning device 51, a large amount of toner is prevented from flowing into the upstream of the toner conveyance direction D1 of the screw member 514 at once, and toner accumulation on the upstream side of the screw conveyance direction D1 of the screw member 514 is prevented. It is possible to suppress.

  In this embodiment, the cleaning device 51 that removes toner from the intermediate transfer belt 5 will be described as an example of the cleaning device according to the present invention. However, the cleaning device according to the present invention is also applicable to the drum cleaning device. Is possible. In this case, the photosensitive drum is an example of a member to be cleaned, and a member that removes toner from the photosensitive drum is an example of a cleaning member.

  In the present embodiment, the second roller 512 is an example of a member to be cleaned, and the cleaning member 513 is an example of a cleaning member. On the other hand, a configuration in which the second roller 512 is omitted and the cleaning member 513 removes toner from the first roller 511 is also conceivable as another embodiment. In this case, the first roller 511 is an example of a member to be cleaned. Furthermore, a configuration in which the first roller 511 and the second roller 512 are omitted and the cleaning member 513 removes toner from the intermediate transfer belt 5 is also conceivable as another embodiment. In this case, the intermediate transfer belt 5 is a member to be cleaned. It is an example.

1-4 Image forming unit 5 Intermediate transfer belt 51 Cleaning device 511 First roller 512 Second roller 513 Cleaning member 514 Screw member 518 Toner receiving portion 518A One end 518B The other end

Claims (5)

A cleaning member for removing toner from the member to be cleaned;
A screw member for conveying the toner removed by the cleaning member along a predetermined conveyance direction;
One end is provided on the toner dropping path from the cleaning member to the upstream end in the conveying direction of the screw member in a state of urging the surface of the screw member, and as the screw member rotates, A toner receiving portion on which the one end portion swings;
A cleaning device comprising: The toner receiving portion is an L-shaped film member having one end portion in contact with the surface of the screw member and the other end portion fixed to a support portion that rotatably supports the screw member.
The cleaning device according to claim 1. The toner receiving portion has the one end portion within a range of a spiral projection portion for one cycle formed on the most upstream side in the transport direction in the screw member.
The cleaning device according to claim 1 or 2. The member to be cleaned;
A cleaning device according to any one of claims 1 to 3,
An image forming apparatus comprising: An intermediate transfer belt on which toner images are transferred from a plurality of photoconductors;
The member to be cleaned is the intermediate transfer belt, a first roller for removing toner from the intermediate transfer belt, or a second roller for removing toner from the first roller;
The image forming apparatus according to claim 4.

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