JP2022169260A - Cleaning unit and image forming apparatus - Google Patents

Abstract

To provide a cleaning unit that allows easy checking of the state of contact between an electrode and a collar.SOLUTION: A cleaning unit 7 comprises: a belt cleaning roller 71 that removes a toner attached to a transfer belt 41 in contact with a photoconductor drum 51, extends along an axis X, and includes one end 71A and the other end 71B in the axis X direction; a frame 70 that supports the belt cleaning roller 71; an electrode 85 that is electrically connected with the belt cleaning roller 71; a collar 81 that is attached to one end 71A of the belt cleaning roller 71 and in contact with the electrode 85; and a cover 90 that covers a first side wall 70A on one end in the axis X direction of the frame 70. The cover 90 has a through hole 91 penetrating in the axis X direction at a position opposite to the collar 81 in the axis X direction.SELECTED DRAWING: Figure 2

Description

The present invention relates to a cleaning unit and an image forming apparatus.

2. Description of the Related Art Conventionally, in an electrophotographic image forming apparatus that forms an image by transferring a toner image carried by a photosensitive drum onto a sheet, a developer remaining on the photosensitive drum is A cleaning unit is provided for collecting via a belt that contacts the photosensitive drum.

The cleaning unit includes a cleaning roller that removes developer adhering to the belt that contacts the photosensitive drum, a frame that supports the cleaning roller, a collar attached to the cleaning roller, and a conductive electrode. . The collar is formed of an electrically conductive member, the electrode is in contact with the collar, and the electrode, collar, and cleaning roller are electrically connected. This makes it possible to apply a bias voltage to the cleaning roller from outside the cleaning unit through the electrode.

In this case, by connecting the electrode and the cleaning roller through the collar, the abrasion of the cleaning roller is suppressed and the electrode and the cleaning roller can be maintained for a long period of time as compared with the case where the electrode and the cleaning roller are directly connected. It is possible to ensure a good connection. In the axial direction of the cleaning roller, the collar is attached to one end of the cleaning roller, the electrode is attached to the side wall of the frame on one end side, and the side wall of the frame on one end side is covered with a cover.

JP 2016-71213 A

In the cleaning unit configured as described above, it is important that the collar and the electrode are in proper contact in order to stably exhibit the function of collecting the developer. However, since the side wall at one end of the frame is covered with a cover, the portion where the collar and the electrode are in contact cannot be visually recognized from the outside, making it difficult to confirm the contact state between the electrode and the collar. rice field.

Accordingly, the present invention provides a cleaning unit and an image forming apparatus that allow easy confirmation of the contact state between the electrode and the collar.

A cleaning unit and an image forming apparatus that solve the above problems have the following features.

That is, the cleaning unit removes the developer adhering to the belt in contact with the photosensitive drum, and supports a cleaning member extending along the axis and having one end and the other end in the axial direction, and the cleaning member. a frame, an electrode electrically connected to the cleaning member, a collar attached to the one end of the cleaning member and in contact with the electrode, and a cover covering a side wall of the frame at one end in the axial direction. and the cover has a through-hole penetrating in the axial direction at a position facing the collar in the axial direction.

As a result, the portion where the collar and the electrode are in contact can be visually recognized from the outside through the through hole, and the contact state between the collar and the electrode can be easily confirmed.

Further, the diameter of the one end portion of the collar in the axial direction is smaller than the diameter of the through hole in the certain direction.

As a result, the inside of the cover can be easily seen through the through hole, and the state of contact between the collar and the electrode can be more easily confirmed.

Further, the collar includes a body portion fitted to the cleaning member, and a flange portion projecting radially outward from an outer surface of the body portion and overlapping a peripheral edge portion of the through hole in the cover when viewed from the axial direction. and have.

As a result, it is possible to prevent the collar from rotating together with the cleaning member due to the contact of the electrode with the collar, thereby stabilizing the state of contact between the collar and the electrode. In addition, it is possible to prevent the collar from falling out of the cleaning member through the through hole.

Further, the flange portion includes a first flange portion and a second flange portion positioned apart from the first flange portion in a direction orthogonal to the axial direction on the outer surface of the main body portion.

Thereby, the rotation of the collar can be restricted both when the electrode contacts the first collar portion and when the electrode contacts the second collar portion, and the rotation of the collar is restricted until the rotation of the collar is restricted. can be reduced in quantity.

Further, the collar has a protrusion that protrudes radially inward from the inner surface of the main body and engages with the cleaning member.

With this configuration, it is possible to prevent the collar from slipping out of the cleaning member due to the engagement of the protrusion with the cleaning member.

Further, the main body portion of the collar is cylindrical, and the collar portion protrudes from the outer peripheral surface of the cylindrical main body portion and has a semicircular arc shape.

As a result, the space occupied by the collar can be reduced at one end of the cleaning member to which the collar is attached, and the size of the cleaning unit can be reduced.

Also, the collar is a conductive member that electrically connects the cleaning member and the electrode.

Thereby, the cleaning member and the electrode can be electrically connected stably.

Also, the cleaning member is a cleaning roller that rotates around the axis.

As a result, the developer adhering to the belt can be easily and continuously removed.

Further, the cleaning roller includes a shaft extending along the axial direction and a roller body covering the shaft, and the collar is attached to one end of the shaft in the axial direction.

As a result, the collar can be stably attached to the cleaning roller.

Further, the cleaning unit according to any one of claims 1 to 9, wherein the cleaning unit is mounted by rotating with respect to the apparatus main body of the image forming apparatus, wherein the frame extends in the same direction as the axial direction. The cover includes a boss that extends and is pivotally attached to the apparatus main body, and a rib that is positioned on one side of the electrode in a direction orthogonal to the axial direction, and the cover extends in the axial direction of the rib. and a covering portion covering a side surface facing one side in a direction orthogonal to the axial direction, the covering portion having an inclined surface inclined with respect to a straight line connecting the rib and the boss in a direction orthogonal to the axial direction. 1 part.

As a result, even if the cover and the device-side electrodes, etc. provided on the apparatus main body abut when the cleaning unit is attached to the apparatus main body, the abutting device-side electrodes, etc., can be escaped by the inclined surface of the first portion. It is possible to prevent the cleaning unit from being prevented from being attached to the main body of the apparatus.

Further, the first portion is positioned with a gap with respect to the rib in a direction orthogonal to the axial direction, and the covering portion fills the gap between the rib and the first portion. A second part covering from one axial side is provided.

As a result, it is possible to prevent the apparatus-side electrodes and the like of the apparatus body on which the cleaning unit is attached from getting stuck in the gap between the rib and the first portion, so that the cleaning unit can be smoothly attached to the apparatus main body.

Further, the first portion is positioned with a gap from the rib in a direction perpendicular to the axial direction, and the frame moves the gap between the rib and the first portion to the axial line. A third part is provided that blocks from a direction orthogonal to the direction and orthogonal to the separation direction between the rib and the first part.

As a result, it is possible to prevent the apparatus-side electrodes and the like of the apparatus body on which the cleaning unit is attached from getting stuck in the gap between the rib and the first portion, so that the cleaning unit can be smoothly attached to the apparatus main body.

Further, an image forming apparatus includes an image forming section having a photosensitive drum and a belt that contacts the photosensitive drum, and the cleaning unit according to any one of claims 1 to 12.

As a result, in the cleaning unit attached to the image forming apparatus, the portion where the collar and the electrode are in contact can be visually recognized from the outside through the through hole, and the contact state between the collar and the electrode can be easily confirmed. .

According to the present invention, the portion where the collar and the electrode are in contact can be visually recognized from the outside through the through hole, and the contact state between the collar and the electrode can be easily confirmed.

1 is a central sectional view showing an image forming apparatus; FIG. 4 is a perspective view showing a cleaning unit; FIG. FIG. 4 is a side cross-sectional view showing a cleaning unit; FIG. 4 is a perspective view showing a conveying member of the cleaning unit; FIG. 4 is a front perspective view showing the right end of the cleaning unit; FIG. 4 is a side view showing the right end of the cleaning unit; FIG. 4 is a front cross-sectional view showing the right end portion of the cleaning unit; FIG. 10 illustrates a collar attached to one end of the belt cleaning roller; FIG. 3 is a perspective view showing an apparatus main body to which a cleaning unit is attached; FIG. 3 is a perspective view showing a device-side first electrode, a device-side second electrode, and a device-side third electrode; FIG. 10 is a rear perspective view showing the right end portion of the cleaning unit without the cover attached; FIG. 10 is a rear perspective view showing the right end portion of the cleaning unit with the cover attached. FIG. 4 is a rear sectional view showing the right end portion of the cleaning unit; FIG. 11 is a side view showing a covering portion of a cover attached to the right end of the cleaning unit; FIG. 4 is a side view showing the first and second parts of the cover portion of the cover, the gap between the first part and the rib, and the third part of the frame;

Next, a mode for carrying out the present invention will be described with reference to the accompanying drawings.

[Image forming device]
An image forming apparatus 1 shown in FIG. 1 is an embodiment of the image forming apparatus according to the present invention, and is a color laser printer that forms images of multiple colors on a sheet S by electrophotography.

In the following description, the right side in FIG. 1 is defined as the front side of the image forming apparatus 1, the left side in FIG. The back side of the paper is defined as the right side of the image forming apparatus 1 . Further, the upper side and the lower side in FIG. 1 are defined as the upper side and the lower side of the image forming apparatus 1, respectively.

The image forming apparatus 1 includes an apparatus main body 2, a sheet feeding section 3 having a sheet feeding tray 10 for supporting a sheet S and a sheet conveying section 30 for conveying the sheet S, and a sheet S conveyed by the sheet feeding section 3. and an image forming unit 5 for forming an image.

The apparatus main body 2 is formed in a substantially rectangular parallelepiped shape, and accommodates the paper feeding section 3 and the image forming section 5 . An opening 2A is opened in the upper surface of the apparatus main body 2, and the apparatus main body 2 has a top cover 23 capable of opening and closing the opening 2A.

The top cover 23 is configured to be rotatable about a rotating shaft 23a at its rear end, and rotates about the rotating shaft 23a to move between a closed position for closing the opening 2A and a closed position for closing the opening 2A. It is movable between an open position to open 2A. A top cover 23 of the apparatus main body 2 is formed with a discharge tray 23b that slopes downward from the front side to the rear side.

The paper feeding section 3 is arranged in the lower part of the apparatus main body 2 and conveys the sheet S supported by the paper feeding tray 10 to the image forming section 5 by the sheet conveying section 30 . The paper feed tray 10 is configured to be slidable in the front-rear direction, and is configured to be movable between an accommodation position accommodated in the apparatus main body 2 and a separation position pulled forward from the accommodation position.

The sheet conveying section 30 includes a sheet feed roller 32 , a separation roller 33 , a separation pad 33 a , a pair of conveying rollers 34 , and a pair of registration rollers 35 . In the apparatus main body 2, a conveying path P for the sheet S is configured from the paper feed tray 10 to the paper discharge tray 23a via the image forming section 5. As shown in FIG.

The sheets S supported by the paper feed tray 10 are separated one by one by the paper feed roller 32, the separation roller 33 and the separation pad 33a, and sent to the transport path P. As shown in FIG. The paper feed roller 32 is a roller that conveys the sheet S from the paper feed tray 10 toward the image forming section 5 . The separation roller 33 and the separation pad 33a constitute separation means for separating the sheets S supported by the paper feed tray 10 one by one.

The sheet S sent out to the transport path P is transported toward the image forming section 5 by the transport roller pair 34 and the registration roller pair 35 . The registration roller pair 35 restricts the movement of the leading edge of the conveyed sheet S to temporarily stop it, and then conveys the sheet S toward the image forming unit 5 at a predetermined timing.

The image forming section 5 is arranged above the paper feeding section 3 and has four process cartridges 50 arranged side by side in the front-rear direction. Each process cartridge 50 is provided for each color of black, yellow, magenta, and cyan. The process cartridge 50 is detachably attached to the apparatus main body 2 . The process cartridge 50 includes a photosensitive drum 51 , a developing roller 52 , a supply roller 53 , a charger 54 and a drum cleaning roller 55 .

The photosensitive drum 51 is formed in a substantially cylindrical shape whose axial direction is the horizontal direction, and is rotatably supported by the process cartridge 50 . The developing roller 52 extends laterally and is rotatably supported by the process cartridge 50 . The supply roller 53 supplies toner contained in the process cartridge 50 to the developing roller 52 . Toner is an example of a developer. The developing roller 52 supplies toner to the photosensitive drum 51 .

The apparatus main body 2 has an exposure head 59 that exposes the surface of the photosensitive drum 51 . The exposure head 59 is supported by the top cover 23 . Four exposure heads 59 are provided corresponding to each photosensitive drum 51, and each exposure head 59 is arranged side by side in the front-rear direction.

The exposure head 59 extends downward from the top cover 23 and has an exposure portion 59a at its lower end. The exposure unit 59a is arranged above and close to the photosensitive drum 51 when the top cover 23 is closed. The exposure unit 59a is configured by an LED array having a plurality of LED elements arranged side by side in the left-right direction.

A transfer belt 41 is arranged below the photosensitive drum 51 with the transport path P interposed therebetween. The transfer belt 41 is in contact with the photosensitive drum 51 . The transfer belt 41 is stretched between a drive roller 42 and a driven roller 43 arranged in front of the drive roller 42 . Transfer rollers 44 are arranged at positions facing the respective photosensitive drums 51 with the transfer belt 41 interposed therebetween. In the image forming section 5, a transfer belt 41, a drive roller 42, a driven roller 43, a transfer roller 44, and the like constitute a belt device 40. As shown in FIG.

In the image forming section 5 , the photosensitive drums 51 uniformly charged by the charger 54 are selectively exposed by the exposure heads 59 . This exposure selectively removes charges from the surface of the photosensitive drum 51 and forms an electrostatic latent image on the surface of the photosensitive drum 51 .

The toner contained in the process cartridge 50 is positively charged between the supply roller 53 and the developing roller 52 and carried on the surface of the developing roller 52 . A developing bias is applied to the developing roller 52 , and when the electrostatic latent image formed on the photosensitive drum 51 faces the developing roller 52 , the potential difference between the electrostatic latent image and the developing roller 52 causes the developing roller 52 to supplies toner to the electrostatic latent image. Thereby, a toner image is formed on the surface of the photosensitive drum 51 .

When the sheet S conveyed toward the image forming unit 5 reaches the transfer belt 41 , it is conveyed by the transfer belt 41 and sequentially passes between the transfer belt 41 and each photosensitive drum 51 . Then, the toner image carried on the surface of the photosensitive drum 51 is transferred onto the sheet S by the transfer bias applied to the transfer roller 44 when facing the sheet S. As shown in FIG.

At this time, toner that has not been transferred to the sheet S may remain on the surface of the photosensitive drum 51 . Waste toner remaining on the surface of the photosensitive drum 51 faces the drum cleaning roller 55 as the photosensitive drum 51 rotates. The waste toner facing the drum cleaning roller 55 is electrically retained on the surface of the drum cleaning roller 55 by the drum cleaning bias.

In this embodiment, the transfer belt 41 is configured as a conveying belt that conveys the sheet S onto which the toner image is transferred. It is also possible to construct an intermediate transfer belt to be transferred to S.

The sheet S onto which the toner image has been transferred is conveyed to the fixing device 60 . The fixing device 60 has a heating roller 61 and a pressure roller 62 that presses against the heating roller 61 . The toner image is thermally fixed on the surface.

The sheet S on which the toner image is thermally fixed is conveyed from the fixing device 60 to the downstream side in the conveying direction. It is conveyed by pair 64 and ejected to paper ejection tray 23b.

A cleaning unit 7 is provided below the transfer belt 41 and above the paper feed tray 10 in the apparatus main body 2 to collect and store toner adhering to the transfer belt 41 . The cleaning unit 7 is detachably attached to the apparatus main body 2 .

The cleaning unit 7 has a frame 70 , a belt cleaning roller 71 , a collecting roller 72 and a scraping blade 73 . The belt cleaning roller 71 and the collection roller 72 are each rotatably supported by the frame 70 .

The belt cleaning roller 71 is arranged below the transfer belt 41 at a position facing the backup roller 45 arranged inside the transfer belt 41 . The backup roller 45 is arranged inside the transfer belt 41 so as to contact the transfer belt 41 from above.

The collecting roller 72 is in contact with the belt cleaning roller 41 from behind. The scraping blade 45 is supported by the frame 70 and arranged behind and below the collecting roller 44 . A front end of the scraping blade 45 is in contact with the surface of the collection roller 44 . A storage chamber 74 is formed inside the frame 70 to store collected waste toner.

[Waste Toner Cleaning Operation]
In the image forming apparatus 1 , after image formation by the image forming section 5 is completed, a cleaning operation is performed in which waste toner held by the drum cleaning roller 55 is collected by the cleaning unit 7 and stored in the storage chamber 74 .

In the cleaning operation, waste toner held by the drum cleaning roller 55 is first discharged onto the surface of the photosensitive drum 51, and the photosensitive drum 51 is rotated. The waste toner ejected onto the surface of the photosensitive drum 51 faces the transfer belt 41 as the photosensitive drum 51 rotates.

The waste toner on the surface of the photosensitive drum 51 facing the transfer belt 41 is transferred to the surface of the transfer belt 41 by the transfer bias of the transfer roller 44 . After that, the waste toner transferred to the surface of the transfer belt 41 is transported to a position facing the belt cleaning roller 71 as the transfer belt 41 rotates.

The waste toner facing the belt cleaning roller 71 is electrostatically held on the surface of the belt cleaning roller 71 by the belt cleaning bias applied to the belt cleaning roller 71 . That is, the belt cleaning roller 71 removes toner adhering to the transfer belt 41 .

The belt cleaning roller 71 is an example of a cleaning member that removes developer adhering to the belt. By configuring the cleaning member with the belt cleaning roller 71 which is a roller member, it is possible to easily and continuously remove the toner adhering to the transfer belt 41 .

In the present embodiment, an example in which the belt cleaning roller 71, which is a roller-shaped member, is applied as the cleaning member is shown, but as the cleaning member, other types of cleaning member such as a blade-shaped cleaning member may be used. It is also possible to use

The toner held by the belt cleaning roller 71 is electrostatically transferred to the collection roller 72 . The waste toner transferred to the collection roller 72 is scraped off by the scraping blade 73 and falls, and is stored in the storage chamber 74 .

[Cleaning unit]
As shown in FIGS. 2 and 3, the belt cleaning roller 71 of the cleaning unit 7 extends along the axis X. As shown in FIG. The belt cleaning roller 71 is a roller member that rotates around the axis X. As shown in FIG. The belt cleaning roller 71 is an example of a cleaning roller. The belt cleaning roller 71 has one end portion 71A and the other end portion 71B in the axis X direction. The axis X is an axis extending in the left-right direction.

The frame 70 has a first side wall 70A facing in the left-right direction on the right end side, which is one end side of the axis X, and a first side wall 70A facing in the left-right direction on the left end side, which is the other end side of the axis X. It has a second side wall 70B that The first side wall 70A is an example of a side wall on the one end side in the axial direction of the frame. One end 71A of the belt cleaning roller 71 is supported by the first side wall 70A of the frame 70, and the other end 71B of the belt cleaning roller 71 is supported by the second side wall 70B of the frame 70. As shown in FIG.

The belt cleaning roller 71 includes a metal shaft 711 extending along the axis X direction, and a cylindrical roller body 712 made of a conductive resin member and covering the shaft 711 . The toner adhering to the transfer belt 41 is removed by contacting the belt 41 .

The recovery roller 72 is formed of a substantially cylindrical metal member extending in the left-right direction, and is in pressure contact with the roller body 712 of the belt cleaning roller 71 . The collecting roller 72 has one end 72A and the other end 72B in the X-axis direction.

The scraping blade 45 is formed of a plate-like member whose longitudinal direction is the left-right direction, and is in pressure contact with the recovery roller 72 . The scraping blade 45 scrapes off and collects the toner adhering to the collecting roller 72 . In the cleaning unit 7 , the toner adhering to the transfer belt 41 is removed by the belt cleaning roller 71 , collection roller 72 and scraping blade 45 and stored in the storage chamber 74 .

A bottom surface 70C of the frame 70 forming the storage chamber 74 has a stepped portion 701 in the middle in the front-rear direction. The storage chamber 74 includes a first storage portion 74A positioned forward of the stepped portion 701 and a second storage portion 74B positioned rearward of the stepped portion 701 . The vertical position of the bottom surface 70C of the second housing portion 74B is higher than the vertical position of the bottom surface 70C of the first housing portion 74A, and the depth of the second housing portion 74B is smaller than the depth of the first housing portion 74A. . The storage chamber 74 is closed from above by an upper surface 70</b>D of the frame 70 .

As shown in FIGS. 3 and 4 , the cleaning unit 7 has a conveying member 75 positioned inside the storage chamber 74 . The conveying member 75 is a member that conveys the toner accommodated in the accommodation chamber 74 rearward, and has a main body portion 751 , a crankshaft 752 and a fulcrum portion 753 .

The body portion 751 is a lattice-shaped member, and includes a rectangular frame 751a, first and second conveying ribs 751b and 751c extending in the left-right direction within the frame 751a, It has a connecting rib 751d extending in a direction orthogonal to the extending direction of the conveying rib 751b and the second conveying rib 751c, and a supported portion 751e.

The connecting rib 751d spans between the front end and the rear end of the frame 751a. The first conveying rib 751b and the second conveying rib 751c span between the left end and the right end of the frame 751a. The rear surface of the first transport rib 751b faces the extending direction of the connecting rib 751d. The rear surface of the second conveying rib 751c is inclined upward with respect to the extending direction of the connecting rib 751d. The second conveying rib 751c is positioned in front of the conveying member 75, and the first conveying rib 751b is positioned behind the second conveying rib 751c. The supported portion 751 e is located at the front end portion of the frame 751 .

The crankshaft 752 has a rotating shaft portion 752a, a support portion 752b, and an arm portion 752c. The rotating shaft portion 752 a is a shaft member that rotates around a rotating axis Y extending in the left-right direction, and is arranged at both left and right end portions of the crank shaft 752 .

The support portion 752b is a shaft member that extends in the left-right direction, is arranged eccentrically with respect to the rotation axis Y, and is positioned between the left and right rotation shaft portions 752a. The supporting portion 752b supports the supported portion 751e of the body portion 751. As shown in FIG. The arm portion 752c extends radially outward from the rotating shaft portion 752a and connects the rotating shaft portion 752a and the support portion 752b. That is, the left and right end portions of the support portion 752b are supported by the rotation shaft portion 752a via the arm portions 752c.

The supporting portion 752b is eccentric with respect to the rotating shaft portion 752a, and when the rotating shaft portion 752a rotates about the rotating shaft Y, the supporting portion 752b revolves around the rotating shaft Y.

The fulcrum portion 753 is positioned at the rear end portion of the main body portion 751 and is formed in a boss shape extending in the left-right direction. The fulcrum portions 753 are arranged at both left and right end portions of the body portion 751 .

The frame 70 has a lower support wall 702 protruding upward from the bottom surface 70C within the second housing portion 74B, and an upper support wall 703 protruding downward from the upper surface 70D. The fulcrum portion 753 is positioned between the upper end of the lower support wall 702 and the lower end of the upper support wall 703, and is sandwiched between the lower support wall 702 and the upper support wall 703 so as to be movable forward and backward.

In the conveying member 75 configured in this manner, when the rotation shaft portion 752a shown in FIG. 3 rotates counterclockwise, the support portion 752b revolves around the rotation axis Y counterclockwise. When the supporting portion 752b revolves, the front end portion of the conveying member 75 supported by the supporting portion 752 by the supported portion 751e moves along the circular revolving locus of the supporting portion 752b. Further, the rear end portion of the conveying member 75 supported by the frame 70 by the fulcrum portion 753 moves in the front-rear direction along with the movement of the front end portion of the conveying member 75 .

In this case, when the support portion 752b revolves counterclockwise from the lowest point in the revolution locus, the front end portion of the conveying member 75 moves rearward and obliquely upward, and the first conveying rib 751b and the second conveying rib 751c move. The toner stored in the storage chamber 74 is scraped off and conveyed backward.

In particular, when the front end portion of the conveying member 75 moves rearward and obliquely upward, the amount of vertical movement of the front end portion of the conveying member 75 is larger than the amount of vertical movement of the rear end portion of the conveying member 75, and the rear surface of the second conveying rib 751c is connected to the connecting rib 751d. , the toner stored in the storage chamber 74 is transported rearward and obliquely upward by the second transport rib 751c.

The second conveying rib 751c is positioned near the stepped portion 701 in the first containing portion 74A, and the toner is conveyed obliquely rearward and upward by the second conveying rib 751c to be contained in the first containing portion 74A. Toner can be easily conveyed to the second container 74B over the stepped portion 701.

As shown in FIGS. 5 to 7, at one end 71A of the belt cleaning roller 71, the shaft 711 has a bearing portion 711a, a collar support portion 711b, and an engaging portion 711c. A bearing portion 711 a of the shaft 711 is supported by the first side wall 70 A of the frame 70 via a bearing 80 . The collar support portion 711b of the shaft 711 is positioned to the right of the bearing portion 711a and protrudes to the right of the first side wall 70A of the frame 70 .

The cleaning unit 7 has a collar 81 attached to one end 71A of the belt cleaning roller 71 . The collar 81 is attached to a collar support portion 711b of a shaft 711 positioned at one end portion 71A of the belt cleaning roller 71. As shown in FIG.

That is, the collar 81 is attached to one end of the shaft 711 in the X-axis direction. By attaching the collar 81 to one end of the shaft 711 , the collar 81 can be stably attached to the belt cleaning roller 71 . The engaging portion 711c is formed in the shape of a groove extending in the circumferential direction at the boundary between the bearing portion 711a and the collar support portion 711b.

As shown in FIG. 8, the collar 81 is made of a conductive member such as a conductive resin, and includes a body portion 811, a first flange portion 812, a second flange portion 813, and a projecting portion 814. I have. The first collar portion 812 and the second collar portion 813 are examples of the collar portion.

The body portion 811 is formed in a cylindrical shape and is fitted on the collar support portion 711b of the shaft 711 . The first brim portion 812 and the second brim portion 813 protrude radially outward from the cylindrical outer peripheral surface, which is the outer surface of the main body portion 811 . The first brim portion 812 and the second brim portion 813 are formed to have a semicircular outer shape.

By forming the main body portion 811 in a cylindrical shape and forming the first flange portion 812 and the second flange portion 813 in a semi-circular shape, the one end portion 71A of the belt cleaning roller 71 to which the collar 81 is attached can be , the space occupied by the collar 81 can be reduced, and the size of the cleaning unit 7 can be reduced.

The second collar portion 813 is located apart from the first collar portion 812 in the circumferential direction of the body portion 811 . In other words, the second collar portion 813 is positioned apart from the first collar portion 812 in a direction orthogonal to the axis X direction on the outer surface of the main body portion 811 . In the present embodiment, the first flange portion 812 and the second flange portion 813 are positioned in phases that differ by 180° in the circumferential direction of the main body portion 811 .

The protruding portion 814 protrudes radially inward from the inner peripheral surface, which is the inner surface of the main body portion 811 . The projecting portion 814 can be engaged with the engaging portion 711 c of the shaft 711 . As shown in FIG. 8C, when the body portion 811 of the collar 81 is fitted onto the collar support portion 711b of the shaft 711, the projecting portion 814 and the engaging portion 711c are engaged. Accordingly, it is possible to prevent the collar 81 fitted in the collar support portion 711 b from coming off the shaft 711 .

One end of the recovery roller 72 in the X-axis direction is supported by the first side wall 70A of the frame 70, and the other end of the recovery roller 72 in the X-axis direction is supported by the second side wall 70B of the frame 70. . One end of the collection roller 72 is supported by the first side wall 70A via a bearing 82. As shown in FIG. One end of the collection roller 72 in the direction of the axis X protrudes to the right from the first side wall 70A of the frame 70 . A collar 83 is attached to one end of the collecting roller 72 .

The collar 83 is configured similarly to the collar 81 and includes a body portion 831 , a first flange portion 832 and a second flange portion 833 . The body portion 831, the first collar portion 832, and the second collar portion 833 correspond to the body portion 811, the first collar portion 812, and the second collar portion 813 of the collar 81, respectively.

The collar 83 has a protrusion (not shown) that protrudes radially inward from the inner peripheral surface of the main body 821 . By combining them, it is possible to prevent the collar 83 from slipping out of the recovery roller 72 .

The cleaning unit 7 has an electrode 85 attached to the first side wall 70A of the frame 70 . The electrode 85 has a first electrode 851 , a second electrode 852 and a third electrode 853 .

The first electrode 851 is made of a bent metal plate and has a body portion 851a and an external contact portion 851b. The body portion 851a is fixed to the right side surface of the first side wall 70A. The external contact portion 851b is formed continuously below the body portion 851a on the right side surface of the first side wall 70A.

The second electrode 852 is made of a bent metal plate and has a body portion 852a, an external contact portion 852b, and a contact portion 852c. The body portion 852a is fixed to the right side surface of the first side wall 70A. The external contact portion 852b is formed continuously below the body portion 852a on the right side surface of the first side wall 70A. The main body portion 852 a is positioned behind the main body portion 851 a of the first electrode 851 , and the external contact portion 852 b is positioned behind the external contact portion 851 b of the first electrode 851 .

The contact portion 852 c extends obliquely forward and upward from the body portion 852 a and contacts the outer peripheral surface of the body portion 811 of the collar 81 . Since the collar 81 is made of a conductive material, the second electrode 852 and the shaft 711 of the belt cleaning roller 71 are electrically connected when the contact portion 852c contacts the main body portion 811 . The second electrode 852 is an example of an electrode electrically connected to the cleaning member.

Further, the collar 81 is a conductive member that electrically connects the belt cleaning roller 71 and the second electrode 852 by coming into contact with the second electrode 852 , stably electrically connecting the belt cleaning roller 71 and the second electrode 852 . It is possible to connect to

The third electrode 853 is made of a bent metal plate and has a body portion 853a, an external contact portion 853b, and a contact portion 853c. The body portion 853a is fixed to the right side surface of the first side wall 70A. The external contact portion 853b is formed continuously below the body portion 853a on the right side surface of the first side wall 70A. The main body portion 853 a is located behind the main body portion 852 a of the second electrode 852 , and the external contact portion 853 b is located behind the external contact portion 852 b of the second electrode 852 .

The contact portion 853 c extends obliquely forward and upward from the body portion 853 a and contacts the outer peripheral surface of the body portion 831 of the collar 83 . Since the collar 83 is made of a conductive member, the third electrode 853 and the collection roller 72 are electrically connected by the contact portion 853c coming into contact with the main body portion 831 .

The first electrode 851 is configured to be grounded when the cleaning unit 7 is attached to the apparatus main body 2 . Further, when the cleaning unit 7 is attached to the apparatus main body 2 , the belt cleaning bias is applied to the second electrode 852 and the power supply voltage is applied to the third electrode 853 .

The cleaning unit 7 has a cover 90 that covers the first side wall 70A of the frame 70 from the right side. The cover 90 covers the collar 81, the collar 83, the body portion 851a of the first electrode 851, the body portion 852a and the contact portion 852c of the second electrode 852, the body portion 853a and the contact portion 853c of the third electrode 853, and the like. .

The cover 90 has a circular through-hole 91 penetrating in the X-axis direction at a position facing the collar 81 in the X-axis direction. The diameter D1 of the right end portion 811a of the main body portion 811, which is one end portion of the collar 81 in the direction of the axis X, is smaller than the diameter D2 of the through hole 91. As shown in FIG.

In the present embodiment, the through-hole 91 is formed in a circular shape, and the body portion 811 of the collar 81 is formed in a cylindrical shape, so that the diameter D1 is smaller than the diameter D2 in all phases in the radial direction. there is However, for example, when the inner shape of the through hole 91 and the outer shape of the right end portion 811a of the main body portion 811 are formed in a rectangular shape other than a circular shape, at least the diameter of the right end portion 811a of the main body portion 811 in a certain direction is equal to the diameter of the right end portion 811a. It may be smaller than the diameter of the hole 91 in the certain direction.

In the cleaning unit 7, a belt cleaning bias is applied to the belt cleaning roller 71 via the second electrode 852 and the collar 81, so it is important that the collar 81 and the second electrode 852 are in proper contact. .

Therefore, in the cleaning unit 7, by forming the through hole 91 in the cover 90 covering the contact portion 852c of the collar 81 and the second electrode 852, the contact portion 852c of the collar 81 and the contact portion 852c is formed through the through hole 91. Visible from the outside. This makes it possible to easily confirm the contact state between the collar 81 and the second electrode 852 .

In particular, since the diameter D1 of the right end portion 811a of the main body portion 811 of the collar 81 is smaller than the diameter D2 of the through hole 91 of the cover 90, the inside of the cover 90 can be easily viewed through the through hole 91. It is possible to more easily confirm the contact state with the electrode 852 .

The first flange portion 812 and the second flange portion 813 of the collar 81 are formed to have a size that overlaps with the peripheral portion of the through hole 91 in the cover 90 when viewed from the axis X direction. That is, the first brim portion 812 and the second brim portion 813 extend to the outer diameter side of the peripheral portion of the through hole 91 in the cover 90 in the radial direction.

Collar 81 is prevented from slipping out of shaft 711 in a state before cover 90 is attached to first side wall 70A, for example, by engaging projecting portion 814 with shaft 711 . On the other hand, after the cover 90 is attached to the first side wall 70A, for example, when the cleaning unit 7 is carried, an impact may be applied to the cleaning unit 7 and the engagement state between the collar 81 and the shaft 711 may be released. be.

Thus, when the engagement state between the collar 81 and the shaft 711 is released, the diameter D1 of the right end portion 811a of the body portion 811 of the collar 81 is smaller than the diameter D2 of the through hole 91, so that the body portion 811 moves to the right end. There is a possibility that the collar 81 may enter the through hole 91 from the portion 811a and move to the right.

However, since the first collar portion 812 and the second collar portion 813 of the collar 81 are formed to have a size that overlaps with the peripheral portion of the through hole 91, when the collar 81 moves to the right, the first collar portion 812 and the second collar portion 813 interfere with the peripheral edge portion of the through hole 91 to suppress further rightward movement of the collar 81 . As a result, when the collar 81 moves rightward, it can be prevented from coming off the shaft 711 through the through hole 91 .

The first flange portion 812 and the second flange portion 813 protrude radially outward from the outer peripheral surface of the main body portion 811 . Therefore, when the belt cleaning roller 71 rotates, if the collar 81 tries to rotate along with the shaft 711, the contact portion 852c of the second electrode 852 contacting the outer peripheral surface of the main body portion 811 will not move to the first collar portion 812 or the second electrode. It is possible to prevent the collar 81 from rotating together with the shaft 711 by coming into contact with the collar portion 813 . This makes it possible to stabilize the contact state between the collar 81 and the second electrode 852 .

In particular, the collar 81 includes a first collar portion 812 and a second collar portion 813 that is positioned apart from the first collar portion 812 in the circumferential direction, and when the contact portion 852c contacts the first collar portion 812, , and when the contact portion 852c contacts the second collar portion 813, the rotation of the collar 81 can be restricted. Therefore, it is possible to reduce the amount of rotation of the collar 81 until the rotation of the collar 81 is restricted, compared to the case where only one of the first collar 812 and the second collar 813 is provided. .

The cover 90 has a circular through-hole 92 penetrating in the X-axis direction at a position facing the collar 83 in the X-axis direction. As a result, the state of contact between the collar 83 and the third electrode 853 can be easily confirmed by viewing from the outside through the through hole 92 . In particular, the diameter of the right end portion of the main body portion 831 of the collar 83 is formed to be smaller than the diameter of the through hole 92, so that the contact portion 853c of the collar 83 and the third electrode 853 contact through the through hole 92. It is possible to more easily confirm the contact state of

The first flange portion 832 and the second flange portion 833 of the collar 83 are formed to have a size that overlaps the periphery of the through hole 92 in the cover 90 when viewed from the axis X direction. Therefore, even if the collar 83 is disengaged from the recovery roller 72 and the collar 83 moves to the right, the first and second flanges 832 and 833 will interfere with the periphery of the through hole 92 . Therefore, it is possible to prevent the collar 83 from coming off the recovery roller 72 through the through hole 92 .

The first flange portion 832 and the second flange portion 833 protrude radially outward from the outer peripheral surface of the body portion 831 . Therefore, the contact portion 853c of the third electrode 853 that contacts the outer peripheral surface of the main body portion 831 contacts the first flange portion 832 or the second flange portion 833, and the collar 83 can be prevented from rotating together with the recovery roller 72. . This makes it possible to stabilize the contact state between the collar 83 and the third electrode 853 .

As shown in FIG. 2, the frame 70 of the cleaning unit 7 has a fulcrum boss 704 and a pivot boss 705 extending in the same direction as the axis X direction. A pair of fulcrum bosses 704 are arranged on the left and right at the rear end of the frame 70 . The right fulcrum boss 704 projects rightward from the first sidewall 70A, and the left fulcrum boss 704 projects leftward from the second sidewall 70B. A pair of rotating bosses 705 are arranged on the left and right at the front end of the frame 70 . The right rotating boss 705 projects rightward from the first side wall 70A, and the left rotating boss 705 projects leftward from the second side wall 70B.

As shown in FIG. 9, the apparatus main body 2 includes a first main body frame 24 and a second main body frame 25 which are spaced apart from each other in the left-right direction. The first body frame 24 is located at the right end of the device body 2 and extends in the front-back direction and the up-down direction. The second body frame 25 is located at the left end of the device body 2 and extends in the front-back direction and the up-down direction.

The cleaning unit 7 is arranged between the first body frame 24 and the second body frame 25 and is detachably supported by the first body frame 24 and the second body frame 25 .

The first body frame 24 includes a fulcrum guide portion 241 that rotatably guides the right fulcrum boss 704 of the frame 70, and a mounting guide portion 242 that guides the right fulcrum boss 705 of the frame 70. there is Similarly, the second body frame 25 also includes a fulcrum guide portion that rotatably guides the left fulcrum boss 704 of the frame 70 and a mounting guide portion that guides the left fulcrum boss 705 of the frame 70 . there is

When the cleaning unit 7 is attached to the apparatus main body 2, first, the right fulcrum boss 704 of the cleaning unit 7 is fitted into the fulcrum guide portion 241 of the first main body frame 24, and the left fulcrum boss 704 is attached to the second main body. It is fitted to the fulcrum guide portion of the frame 25 . Next, the cleaning unit 7 is rotated around the fulcrum boss 704 in the direction in which the rotation boss 705 moves downward.

Then, the right rotating boss 705 of the cleaning unit 7 is fitted into the mounting guide portion 242 of the first body frame 24, and the left rotating boss 705 is fitted into the mounting guide portion of the second body frame 25. Then, the cleaning unit 7 is attached to the apparatus main body 2 . In this manner, the cleaning unit 7 is configured to be mounted while rotating with respect to the apparatus main body 2 . The fulcrum boss 704 of the cleaning unit 7 is an example of a boss for rotating and attaching to the main body of the apparatus.

As shown in FIG. 10 , the first body frame 24 includes a device-side first electrode 245 , a device-side second electrode 246 , and a device-side third electrode 247 . The first body frame 24 has an inner side surface 24A that faces the second body frame 25 in the left-right direction. It protrudes leftward from the inner surface 24A of the 1 main body frame 24. As shown in FIG. The device-side first electrode 245, the device-side second electrode 246, and the device-side third electrode 247 are each formed by annularly bending a wire spring and have elasticity.

By attaching the cleaning unit 7 to the apparatus main body 2, the device-side first electrode 245 and the external contact portion 851b of the first electrode 851 are brought into contact with each other, and the device-side second electrode 246 and the external contact portion 852b of the second electrode 852 are brought into contact. are in contact with each other, and the device-side third electrode 247 and the external contact portion 853b of the third electrode 853 are in contact with each other.

Contact between the first device-side electrode 245 and the first electrode 851 causes the first electrode 851 to be grounded, and contact between the second device-side electrode 246 and the second electrode 852 causes the second electrode 852 to apply a belt cleaning bias. is applied, and the device-side third electrode 247 and the third electrode 853 come into contact with each other, so that the power supply voltage is applied to the third electrode 853 .

As shown in FIGS. 11 to 13, the frame 70 of the cleaning unit 7 has guide ribs 706 located below the electrodes 85 . Specifically, the guide rib 706 is positioned below the external contact portion 851 b of the first electrode 851 , the external contact portion 852 b of the second electrode 852 , and the external contact portion 853 b of the third electrode 853 . The guide rib 706 protrudes rightward from the first side wall 70A of the frame 70 .

The frame 70 also has ribs 707 located behind the electrodes 85 . Specifically, the rib 707 is located behind the external contact portion 851 b of the first electrode 851 , the external contact portion 852 b of the second electrode 852 , and the external contact portion 853 b of the third electrode 853 . The rib 707 is adjacent to the rear side of the external contact portion 853b. The front-rear direction is an example of a direction orthogonal to the axial direction, and the rear side is an example of one side of the direction orthogonal to the axial direction.

The rib 707 protrudes rightward from the first side wall 70A of the frame 70 . Rib 707 has a rearward facing rear surface 707a. The rear surface 707a is an example of a side surface facing one side in a direction orthogonal to the axial direction.

The cover 90 has a covering portion 93 that covers the rear surface 707a of the rib 707. As shown in FIG. The covering portion 93 has a first portion 931 and a second portion 932 .

As shown in FIG. 14, the first portion 931 covers the rear surface 707a of the rib 707 from behind. The first portion 931 has an inclined surface 931a inclined at an angle θ with respect to the straight line L connecting the rib 707 and the fulcrum boss 704 in the direction perpendicular to the axis X. As shown in FIG. The inclined surface 931a is an inclined surface that slopes upward toward the rear. The inclined surface 931 a is located at the lower end of the first portion 931 .

As shown in FIG. 15, the first portion 931 is positioned with a gap G from the rib 707 in the front-rear direction. The second portion 932 covers the rib 707 and the gap G between the rib 707 and the first portion 931 from the right side in the axis X direction. The right side is an example of one side in the axial direction.

The frame 70 includes a third portion 708 that covers and closes the gap G between the rib 707 and the first portion 931 from below. The third portion 708 protrudes rightward from the first side wall 70A of the frame 70 . The third portion 708 is located at the rear end portion of the guide rib 706 and below the gap G and the first portion 931 . The downward direction is an example of a direction orthogonal to the axial direction and orthogonal to the separation direction between the rib and the first portion.

When the cleaning unit 7 is rotated about the fulcrum boss 704 and attached to the apparatus main body 2, the apparatus side first electrode 245, the apparatus side second electrode 246, and the device side electrode 246 protruding from the inner surface 24A of the first main body frame 24 are mounted. After coming into contact with the guide ribs 706 of the frame 70, the device-side third electrodes 247 contact the external contact portion 851b of the first electrode 851, the external contact portion 852b of the second electrode 852, and the external contact portion 853b of the third electrode 853. come into contact with

The device-side first electrode 245 , the device-side second electrode 246 , and the device-side third electrode 247 have elasticity and are elastically deformed when coming into contact with the guide ribs 706 . In this case, for example, if the external contact portion 853b of the third electrode 853 is deformed rearward, it may contact the lower end portion of the covering portion 93 of the cover 90 . When the device-side third electrode 247 comes into contact with the lower end portion of the covering portion 93, the device-side third electrode 247 contacts with the inclined surface 931a because the inclined surface 931a is formed at the lower end portion of the covering portion 93. becomes.

Since the inclined surface 931a is inclined with respect to the straight line L connecting the rib 707 and the fulcrum boss 704, the device-side third electrode 247 in contact with the inclined surface 931a can be released backward along the inclined surface 931a. can be done. As a result, it is possible to prevent the apparatus-side third electrode 247 from being caught by the covering portion 93 and preventing the cleaning unit 7 from being attached to the apparatus main body 2 .

Further, when the device-side third electrode 247 is deformed when the cleaning unit 7 is attached to the apparatus main body 2, if the gap G between the rib 707 and the first portion 931 extends greatly in the vertical direction, the device-side third electrode 247 may be deformed. The electrode 247 may get stuck in the gap G and hinder the downward movement of the cleaning unit 7 .

However, in the cleaning unit 7, since the gap G between the rib 707 and the first portion 931 is covered from the right side in the direction of the axis X by the second portion 932, the size of the gap G in the vertical direction is small. As a result, the device-side third electrode 247 can be prevented from getting stuck in the gap G, and the cleaning unit 7 can be smoothly attached to the device main body 2 .

Furthermore, when the cleaning unit 7 is attached to the apparatus main body 2, the apparatus-side third electrode 247 approaches the cleaning unit 7 from below, so that it fits into the gap G between the rib 707 and the first portion 931 from below. The movement of the cleaning unit 7 may be hindered.

However, in the cleaning unit 7, since the gap G between the rib 707 and the first portion 931 is covered from below by the third portion 708, it is possible to prevent the apparatus-side third electrode 247 from being fitted into the gap G from below. Therefore, the cleaning unit 7 can be smoothly attached to the apparatus main body 2 .

REFERENCE SIGNS LIST 1 image forming apparatus 2 apparatus body 5 image forming section 7 cleaning unit 41 transfer belt 51 photosensitive drum 70 frame 70A first side wall 71 belt cleaning roller 71A one end 71B other end 72 collection roller 81 collar 85 electrode 90 cover 91, 92 penetration Hole 93 Coating Part 704 Fulcrum Boss 707 Rib 707a Rear Surface 708 Third Part 711 Shaft 711b Collar Supporting Part 712 Roller Body 811 Body Part 811a Right End 812 First Flange 813 Second Flange 814 Protrusion 851 First Electrode 852 Second Electrode 853 Third electrode 931 First part 931a Inclined surface 932 Second part D1 Diameter (right end of collar main body) D2 Diameter (through hole) G Gap X Axis

Claims (13)

a cleaning member that removes developer adhering to the belt in contact with the photosensitive drum, extends along the axis and has one end and the other end in the axial direction;
a frame supporting the cleaning member;
an electrode electrically connected to the cleaning member;
a collar attached to the one end of the cleaning member and in contact with the electrode;
a cover that covers a side wall of the frame on one end side in the axial direction;
with
The cleaning unit, wherein the cover has a through hole penetrating in the axial direction at a position facing the collar in the axial direction. 2. The cleaning unit according to claim 1, wherein the diameter of the one end of the collar in the axial direction is smaller than the diameter of the through hole in the predetermined direction. The color is
a main body fitted in the cleaning member;
a flange projecting radially outward from the outer surface of the main body and overlapping a peripheral edge of the through hole in the cover when viewed from the axial direction;
3. A cleaning unit according to claim 1 or 2, comprising: The said collar part is provided with the 1st collar part and the 2nd collar part located apart from the said 1st collar part in the direction orthogonal to the said axial direction in the said outer-surface of the said main-body part. cleaning unit. 5. The cleaning unit according to claim 3, wherein the collar protrudes radially inward from the inner surface of the main body and includes a protrusion that engages with the cleaning member. the body portion of the collar is cylindrical,
6. The cleaning unit according to any one of claims 3 to 5, wherein the collar protrudes from the cylindrical outer peripheral surface of the main body and has a semicircular arc shape. 7. The cleaning unit according to claim 1, wherein the collar is a conductive member that electrically connects the cleaning member and the electrode. The cleaning unit according to any one of claims 1 to 7, wherein the cleaning member is a cleaning roller that rotates around the axis. The cleaning roller includes a shaft extending along the axial direction and a roller body covering the shaft,
9. The cleaning unit according to claim 8, wherein the collar is attached to one end of the shaft in the axial direction. 10. The cleaning unit according to any one of claims 1 to 9, wherein the cleaning unit is mounted by rotating with respect to the apparatus main body of the image forming apparatus,
The frame extends in the same direction as the axial direction, and includes a boss for rotating and mounting to the apparatus main body, and a rib positioned on one side of the electrode in a direction orthogonal to the axial direction. ,
The cover includes a covering portion that covers a side surface of the rib facing one side in a direction perpendicular to the axial direction,
The cleaning unit, wherein the covering portion has a first portion having an inclined surface inclined with respect to a straight line connecting the rib and the boss in a direction orthogonal to the axial direction. The first part is positioned with a gap from the rib in a direction perpendicular to the axial direction,
11. The cleaning unit according to claim 10, wherein the covering portion includes a second portion that covers the gap between the rib and the first portion from one side in the axial direction. The first part is positioned with a gap from the rib in a direction perpendicular to the axial direction,
10. The frame includes a third portion closing the gap between the rib and the first portion in a direction orthogonal to the axial direction and orthogonal to a direction in which the rib and the first portion are separated. Or a cleaning unit according to claim 11. an image forming unit having a photosensitive drum and a belt in contact with the photosensitive drum;
the cleaning unit according to any one of claims 1 to 12;
An image forming apparatus comprising:

Images