JP7318456B2 - CLEANING DEVICE AND IMAGE FORMING APPARATUS INCLUDING THE SAME - Google Patents

Description

The present invention relates to a cleaning device and an image forming apparatus having the cleaning device.

2. Description of the Related Art In an image forming apparatus such as a printer, a sheet is conveyed to a predetermined image forming position, and an image is formed on the sheet at the image forming position. Conventionally, a pair of registration rollers for feeding a sheet to an image forming position is known. The pair of registration rollers each have a length corresponding to the width of the sheet, and form a nip portion through which the sheet passes. When the leading edge of the sheet comes into contact with the nip portion while the registration roller pair stops rotating, the skew of the sheet is corrected. After that, when the registration roller pair rotates, the sheet is conveyed into the nip portion, and then sent out (conveyed) in accordance with the appropriate image forming timing at the image forming position.

Patent Documents 1 and 2 disclose cleaning devices for removing paper dust adhering to the surfaces of registration rollers. The cleaning device has a web wound in a roll and a pressing roller that presses the web against the surface of the registration roller. As the web is successively fed out, a new web surface comes into contact with the surface of the registration roller. and remove paper dust.

JP 2004-345805 A JP-A-2006-117420

In the techniques described in Patent Documents 1 and 2, the pressing roller presses the web against the lower registration roller of the pair of registration rollers, and the web cleans the surface of the registration roller. When the rolled web is completely unwound, it is necessary to replace the cleaning device. In the pair of registration rollers, mutual nip loads must be appropriately managed in order to send out the sheet. Therefore, when the cleaning device is separated from the main body of the image forming apparatus along the axial direction of the pressing roller while the pressing roller is pressing the web against the lower registration roller, the nip load of the registration roller pair fluctuates. , there is a problem that it is difficult to feed the sheet appropriately. Moreover, such a problem can occur not only in the pair of registration rollers but also in the transport rollers that transport the sheet. If paper dust or toner adheres to the surface of the transport roller, sheet transport failure or toner stains on the sheet will occur, so the transport roller needs to be cleaned. When the cleaning device is attached or detached while the cleaning member such as the web is in contact with the conveying roller, the conveying roller may be deformed or scratched, and the conveying function of the conveying roller may be deteriorated.

SUMMARY OF THE INVENTION The present invention has been made in view of such circumstances, and an object of the present invention is to make it possible to clean the surface of a conveying roller that conveys a sheet and to apply a load to the conveying roller. To provide a cleaning device which can be easily attached to and detached from an apparatus main body and an image forming apparatus having the same.

A cleaning device according to one aspect of the present invention is a cleaning device capable of cleaning the surface of a transport roller that is rotatably supported by an apparatus main body of an image forming apparatus and transports a sheet, wherein the shaft of the transport roller A cleaning unit having a contact surface extending along a direction, the contact surface contacting the surface of the conveying roller from below to clean the surface, and a cleaning housing supporting the cleaning unit. and a moving mechanism capable of moving the cleaning unit between a cleaning position and an attachment/detachment position below the cleaning position, wherein the cleaning portion abuts against the conveying roller at the cleaning position. and a moving mechanism that allows the cleaning section to be spaced downward from the conveying roller at the attachment/detachment position, and allows the cleaning unit to be attached to and detached from the apparatus main body. The cleaning housing includes a pair of wall portions arranged to face each other in the axial direction and supporting the cleaning portion, and a pair of housing shafts protruding from the outer side surfaces of the pair of wall portions in the axial direction. The moving mechanism includes a unit accommodating portion that accommodates the cleaning unit arranged at the attachment/detachment position, and a unit accommodating portion that is arranged in the unit accommodating portion so as to sandwich the cleaning housing from both sides in the axial direction. a pair of support members capable of supporting the cleaning housing in the space between the pair of support members, each of the pair of support members having a shaft support portion for receiving the housing shaft portion and rotatably supporting the housing shaft portion; A support member and a pair of housing shaft portions above the shaft support portions so that the cleaning unit moves between the cleaning position and the attachment/detachment position while the pair of housing shaft portions are supported by the pair of shaft support portions. A rotation drive unit arranged to rotate the pair of support members around a first central axis parallel to the axial direction, wherein the rotation drive unit rotates the cleaning unit in an upward posture as the cleaning unit. a rotation drive portion for rotating the pair of support members while allowing the pair of housing shaft portions to rotate relative to the pair of shaft support portions so as to maintain the unit in the cleaning position; a positioning portion that abuts on the cleaning unit and positions the cleaning unit so that the cleaning portion can clean the conveying roller; A shaft forming a first central axis, a drive unit generating a rotational driving force to rotate the shaft, and a pair of fixed members fixed to the shaft so as to be able to hold the pair of support members. and a pair of spring members interposed between the pair of support members and the pair of fixing members, wherein the pair of spring members are arranged so that the cleaning unit reaches the cleaning position. When rotation of the pair of support members about the first central axis is restricted by abutting on the positioning portion, application of rotational force of the fixed member by the driving portion to the support member is suppressed. and a pair of spring members elastically deformable between the fixed member and the support member so as to allow the fixing member and the support member to perform elastic deformation.

According to this configuration, the cleaning device has the cleaning unit and the moving mechanism, and cleans the surface of the transport roller. The moving mechanism can move the cleaning unit between the cleaning position and the attachment/detachment position. When the moving mechanism places the cleaning unit in the cleaning position, the cleaning portion of the cleaning unit can clean the conveying roller. It can be detached from the main body. As a result, the cleaning unit can be detached from the apparatus main body without applying a load to the conveying roller. Further, the cleaning unit can be moved between the attachment/detachment position and the cleaning position simply by rotating the pair of support members around the first center axis by the rotation driving section. At this time, the pair of housing shaft portions rotate relative to the pair of shaft support portions, so that the cleaning unit can maintain a posture in which the cleaning portion faces upward. Therefore, when the cleaning unit reaches the cleaning position, the cleaning section can quickly contact the conveying roller from below. In addition, since the spring member is interposed between the support member and the fixed member, the spring member is compressed and deformed between the support member and the fixed member, thereby stopping the rotation of the support member around the shaft. is prevented (restricted) from imparting the rotational force of the fixed member to the support member by the driving portion. Therefore, even after the cleaning unit reaches the cleaning position, the shaft can be rotated slightly, so that the difference (error) between the mounting positions of the pair of support members can be absorbed, and the cleaning unit can be reliably brought to the cleaning position. can be placed.

In the above configuration, the cleaning housing includes a pair of outer peripheral surfaces each supported by the pair of wall portions above the housing shaft portion and rotatable about a second central axis parallel to the axial direction. The moving mechanism further includes a guide roller, and the moving mechanism is located on one end side in the width direction perpendicular to the axial direction and spaced from each other in the axial direction from the cleaning unit arranged at the attachment/detachment position. and a pair of guide portions arranged so as to extend in the vertical direction, and allowing the pair of guide rollers to come into contact with the rotation of the pair of support members about the first central axis. It is desirable to further include a pair of guides for guiding the cleaning unit between the cleaning position and the attachment/detachment position.

According to this configuration, the cleaning housing has a pair of guide rollers. Therefore, the cleaning unit can be stably guided between the attachment/detachment position and the cleaning position by the pair of guide rollers and the pair of guide portions according to the rotation of the pair of support members by the rotation drive portion. .

In the above configuration, the pair of support members are arranged to extend downward from the first central shaft in a state where the cleaning unit is arranged at the attachment/detachment position, and the shaft support portion is the one of the support members. The side portion on the one end side in the width direction has a shape in which the other end side opposite to the one end side in the width direction is notched downward, and the housing shaft portion is perpendicular to the axial direction. The rotation driving portion moves the housing shaft portion upward and toward the one end side in the width direction from a state in which the cleaning unit is arranged at the attachment/detachment position. It is preferable that the cleaning unit is moved to the cleaning position by rotating the member about the first central axis.

According to this configuration, at the attachment/detachment position, the pair of housing shaft portions of the cleaning housing can be easily inserted into and removed from the shaft support portions of the pair of support members along the direction perpendicular to the axial direction. In addition, the cleaning unit can be stably moved to the cleaning position above the attachment/detachment position in a state in which the pair of housing shafts are fitted in the shaft supports of the pair of support members.

In the above configuration, when the cleaning unit arranged at the attachment/detachment position is viewed from a direction parallel to the axial direction, the center of the housing shaft portion supported by the shaft support portion is located below the first central axis and The cleaning unit is arranged on the one end side in the width direction, the center of gravity of the cleaning unit is arranged on the one end side in the width direction with respect to the housing shaft portion, and the cleaning unit is rotated from a state in which it is arranged in the attachment/detachment position. When the drive section rotates the pair of support members around the first central axis, the cleaning unit tilts toward the one end side in the width direction about the housing shaft section due to the weight of the cleaning unit itself. , it is preferable that the pair of guide rollers contact the pair of guide portions, respectively.

According to this configuration, when the rotation driving section rotates the pair of support members about the first central axis at the attachment/detachment position, the cleaning unit is tilted by its own weight, and the pair of guide rollers respectively contacts the pair of guide sections. touch. Therefore, it is possible to stably move the cleaning unit from the attachment/detachment position to the cleaning position by means of the rotating drive portion without requiring another drive mechanism for bringing the pair of guide rollers into contact with the pair of guide portions.

In the above configuration, the cleaning housing is made of a magnetic material, and has a connection wall that connects the pair of wall portions along the axial direction. It is preferred to have at least one magnetic member arranged opposite said connecting wall of the housing and generating a magnetic field for retaining said cleaning unit.

According to this configuration, at least one magnetic member generates a magnetic field that holds the cleaning unit in the attachment/detachment position. Therefore, the magnetic binding force of the magnetic member prevents the cleaning unit from falling out of the unit accommodating portion.

In the above configuration, the connection wall of the cleaning housing is a bottom wall that defines the bottom of the cleaning housing, and the at least one magnetic member is the bottom wall of the cleaning unit arranged at the attachment/detachment position. viewed from the direction parallel to the axial direction, the center of the magnetic member in the width direction is the housing supported by the shaft support portion. It is desirable that the shaft portion is arranged closer to the one end side in the width direction than the center of the shaft portion.

According to this configuration, when the rotation driving section rotates the pair of support members, the bottom portion of the cleaning unit tilts, thereby reducing the influence of the magnetic binding force of the magnetic member exerted on the bottom portion, thereby allowing the cleaning unit to move. It can be easily moved towards the cleaning position.

In the above configuration, the cleaning unit includes a strip-shaped web having a contact surface capable of coming into contact with the transport roller, a pressing roller that presses the web against the transport roller, and the transport roller of the web. a delivery roller that delivers the web and a take-up roller that winds the web so that a portion that abuts on the web is changed; It is desirable to further include a web driving mechanism for rotating at least the winding roller among the winding rollers.

According to this configuration, the surface of the transport roller can be stably cleaned by the strip-shaped web. Further, even if the surface of the web becomes dirty, the web can be moved by the rotation of the take-up roller, and the surface of the transport roller can be cleaned by a new contact surface.

In the above configuration, the moving mechanism can move the cleaning unit to a separated position between the cleaning position and the attaching/detaching position in addition to the cleaning position and the attaching/detaching position. , it is preferable that the cleaning unit is arranged below the conveying roller with a space therebetween, and that the cleaning unit and the web driving mechanism are disconnected from each other.

According to this configuration, when an image is formed under conditions in which the surface of the transport roller is not easily soiled, the cleaning unit is arranged at the separated position, thereby reducing the load on the transport roller caused by the contact of the cleaning unit with the transport roller. can be reduced, and unnecessary feeding out of the web can be suppressed.

An image forming apparatus according to another aspect of the present invention includes an apparatus main body, a conveying roller that conveys a sheet, an image forming section that forms an image on the sheet, and any of the above-described image forming apparatuses capable of cleaning the conveying roller. 1. A cleaning device according to 1.

According to this configuration, when the moving mechanism arranges the cleaning unit at the cleaning position, the cleaning section of the cleaning unit can clean the conveying roller. You can put it on and take it off. Therefore, it is possible to stably form an image in the image forming apparatus while stably cleaning the surface of the transport roller.

In the above configuration, the conveying unit includes a conveying unit that conveys the sheet at a position different from the conveying roller, and is attachable to the apparatus main body along a first direction parallel to the axial direction and opposite to the first direction. and a transport unit detachable from the apparatus main body along a second direction of, wherein the unit accommodating section is arranged in the transport unit, and when the cleaning unit is arranged at the attachment/detachment position, the cleaning unit It is desirable that the transfer unit and the transfer unit are detachable from and attachable to the apparatus body integrally.

According to this configuration, it is possible to easily attach and detach the cleaning unit to and from the apparatus main body as well as attach and detach the conveying section that conveys the sheet to and from the apparatus main body.

In the above configuration, when the cleaning unit is detached from the apparatus body integrally with the transport unit, a part of the drive transmission system between the rotary drive section and the pair of support members is cut off. Preferably, the pair of support members are rotatable about the first central axis so as to assist the pair of housing shaft portions of the cleaning unit to be separated from the pair of shaft support portions. .

According to this configuration, when the cleaning unit is detached from the apparatus body integrally with the transport unit, the pair of support members are rotatable about the first central axis, thereby allowing the pair of housing shaft portions of the cleaning unit to rotate. can be easily detached from the pair of shaft supports. As a result, the cleaning unit can be easily removed from the transport unit.

In the above configuration, the transport unit includes a pair of unit frames that are arranged to face each other in the axial direction and that support the transport section, and that connect the pair of unit frames to each other along the axial direction, a lower connection frame that supports the cleaning unit arranged at the attachment/detachment position from below; an upper connection frame defining the unit accommodating portion between the lower connection frame and the lower connection frame so as to cover at least a portion of the arranged cleaning units; The pair of support members are rotated about the first central axis so that the cleaning unit can move out of the unit accommodating portion in a horizontal direction perpendicular to the axial direction and reach the cleaning position above the upper connection frame. It is desirable to move

According to this configuration, the rigidity of the transport unit can be maintained by connecting the pair of unit frames with the upper connection frame and the lower connection frame around the unit housing provided in the transport unit. In addition, even though the upper side of the cleaning unit arranged at the attachment/detachment position is covered by the upper connection frame, the cleaning unit slips out of the unit accommodating portion in the horizontal direction orthogonal to the axial direction and rises above the upper connection frame. The cleaning position can be reached.

The above-described configuration further includes an upper registration roller that conveys the sheet toward the image forming unit in accordance with image formation timing in the image forming unit, and the conveying roller is arranged below the upper registration roller and is positioned below the upper registration roller. A lower registration roller forms a nip portion between itself and an upper registration roller through which the sheet passes, and conveys the sheet toward the image forming section in accordance with the image forming timing. It is desirable to clean the surface of the lower registration roller.

According to this configuration, the cleaning device cleans the surface of the lower registration roller, so that the sheet can be sent out stably to the image forming section.

ADVANTAGE OF THE INVENTION According to the present invention, there is provided a cleaning device capable of cleaning the surface of a conveying roller that conveys a sheet and being easily attached to and detached from an apparatus main body without imposing a load on the conveying roller. can be provided.

1 is a schematic cross-sectional view showing the internal structure of an image forming apparatus according to an embodiment of the invention; FIG. FIG. 2 is a cross-sectional view of the periphery of a pair of registration rollers and a cleaning unit of the image forming apparatus according to one embodiment of the present invention, and is a cross-sectional view in which the cleaning unit is arranged at a cleaning position; 1 is a perspective view of a cleaning unit of an image forming apparatus according to an embodiment of the invention; FIG. 1 is a perspective view of a cleaning unit of an image forming apparatus according to an embodiment of the invention; FIG. 1 is a perspective view of a cleaning unit of an image forming apparatus according to an embodiment of the invention; FIG. 3 is a cross-sectional view of a cleaning unit of the image forming apparatus according to one embodiment of the invention; FIG. FIG. 2 is a front view showing the cleaning unit of the image forming apparatus according to the embodiment of the invention, with some members omitted; 2 is a perspective view showing the internal structure of a cleaning unit of the image forming apparatus according to one embodiment of the invention; FIG. 1 is a perspective view of a cleaning unit and a web delivery mechanism of an image forming apparatus according to an embodiment of the invention; FIG. 2 is an enlarged perspective view of a part of the cleaning unit of the image forming apparatus according to one embodiment of the present invention; FIG. 2 is an enlarged perspective view of a part of the cleaning unit of the image forming apparatus according to one embodiment of the present invention; FIG. FIG. 2 is a perspective view showing a state in which a transport unit frame is detached from a body frame that constitutes the apparatus body of the image forming apparatus according to one embodiment of the present invention; FIG. 2 is a perspective view showing how a conveying unit frame is attached to a main body frame that constitutes the main body of the image forming apparatus according to the embodiment of the present invention; 1 is a perspective view of a transport unit frame of an image forming apparatus according to an embodiment of the invention; FIG. 1 is a perspective view of a transport unit frame of an image forming apparatus according to an embodiment of the invention; FIG. FIG. 4 is a perspective view of a cleaning unit rotating portion of the transport unit frame according to one embodiment of the present invention; FIG. 4 is an enlarged perspective view showing an enlarged part of a cleaning unit rotation portion of the transport unit frame according to the embodiment of the present invention; FIG. 4 is an enlarged perspective view showing an enlarged part of a cleaning unit rotation portion of the transport unit frame according to the embodiment of the present invention; FIG. 4 is a cross-sectional view showing how the cleaning unit is attached to the transport unit frame according to the embodiment of the present invention; FIG. 4 is a cross-sectional view showing how the cleaning unit is attached to the transport unit frame according to the embodiment of the present invention; FIG. 4 is an enlarged perspective view showing how the cleaning unit is attached to the transport unit frame according to the embodiment of the present invention; FIG. 4 is an enlarged perspective view showing how the cleaning unit is attached to the transport unit frame according to the embodiment of the present invention; FIG. 4 is a perspective view showing how a cleaning unit is attached to a transport unit frame according to an embodiment of the present invention; FIG. 4 is a cross-sectional view of the periphery of a pair of registration rollers and a cleaning unit of the image forming apparatus according to the embodiment of the present invention, and is a cross-sectional view of a state in which the cleaning unit is arranged at the attachment/detachment position; FIG. 4 is a cross-sectional view of the periphery of the pair of registration rollers and the cleaning unit of the image forming apparatus according to the embodiment of the present invention, and is a cross-sectional view in which the cleaning unit is slightly pushed up from the attachment/detachment position; FIG. 4 is a cross-sectional view of the vicinity of the pair of registration rollers and the cleaning unit of the image forming apparatus according to the embodiment of the present invention, and is a cross-sectional view in which the cleaning unit is arranged at a separated position; 1 is a cross-sectional perspective view of a pair of registration rollers and a cleaning unit of an image forming apparatus according to an embodiment of the present invention, and is a cross-sectional perspective view of a state in which the cleaning unit is arranged at an attachment/detachment position; FIG. 1 is a cross-sectional perspective view of a registration roller pair and a cleaning unit of an image forming apparatus according to an embodiment of the present invention, and is a cross-sectional perspective view of a state in which the cleaning unit is arranged at a cleaning position; FIG. 1 is a cross-sectional perspective view of a pair of registration rollers and a cleaning unit of an image forming apparatus according to an embodiment of the present invention, and is a cross-sectional perspective view of a state in which the cleaning unit is arranged at an attachment/detachment position; FIG. 1 is a cross-sectional perspective view of a registration roller pair and a cleaning unit of an image forming apparatus according to an embodiment of the present invention, and is a cross-sectional perspective view of a state in which the cleaning unit is arranged at a cleaning position; FIG. FIG. 2 is a cross-sectional view of a pair of registration rollers and a cleaning unit of the image forming apparatus according to one embodiment of the present invention, the cross-sectional view showing a state in which the cleaning unit is arranged at a cleaning position; 7A and 7B are graphs (A), (B) and (C) showing nip load distributions of a pair of registration rollers; FIG. 10 is a cross-sectional perspective view of another pair of registration rollers and a cleaning unit compared with one embodiment of the present invention;

A cleaning device and an image forming apparatus according to one embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a schematic cross-sectional view showing the internal structure of an image forming apparatus 1 according to one embodiment of the invention. The image forming apparatus 1 shown in FIG. 1 is an inkjet recording apparatus that forms (records) an image on a sheet S by ejecting ink droplets. The image forming apparatus 1 includes an apparatus main body 10 , a paper feeding section 20 , a registration roller section 30 , a belt conveying unit 40 , an image forming section 50 and a curl correction section 60 .

The device main body 10 is a box-shaped housing that accommodates various devices for forming an image on the sheet S. As shown in FIG. A first conveying path 11, a second conveying path 12, and a third conveying path 13, which serve as conveying paths for the sheet S, are formed in the apparatus main body 10. As shown in FIG.

The sheet feeding unit 20 feeds the sheet S to the first conveying path 11 . The paper feed unit 20 includes a paper feed cassette 21 and a paper feed roller 22 . The paper feed cassette 21 is detachable from the apparatus main body 10 and accommodates the sheets S therein. The paper feed roller 22 is arranged on the right side of the upper end of the paper feed cassette 21 . The paper feed roller 22 conveys the sheet S accommodated in the paper feed cassette 21 to the downstream side of the first conveying path 11 .

The sheet S fed to the first transport path 11 is moved by the first transport roller pair 111 provided on the first transport path 11 to the registration roller section 30 arranged at the downstream end of the first transport path 11 . be transported. A paper feed tray 24 is arranged on the right side surface of the apparatus main body 10 , and a sheet S can be placed on the upper surface of the paper feed tray 24 . The sheet S placed on the paper feed tray 24 is sent out toward the registration roller section 30 by the paper feed roller 23 .

The registration roller unit 30 is a device that conveys the sheet S conveyed through the first conveying path 11 or the sheet feeding roller 23 toward the conveying belt 41 of the belt conveying unit 40 in the sheet conveying direction A1. Note that the registration roller section 30 and the belt conveying unit 40 convey the sheet S at different positions. Details of the registration roller unit 30 will be described later.

The sheet S conveyed by the registration roller section 30 is conveyed in the sheet conveying direction A2 by the belt conveying unit 40 . Note that the sheet conveying directions A1 and A2 are leftward in FIG.

The belt conveying unit 40 is arranged below the image forming section 50 . The belt conveying unit 40 conveys the sheet S conveyed by the registration roller unit 30 toward the curl correcting unit 60 in the sheet conveying direction A2 so that the sheet S passes below the image forming unit 50 . The belt conveying unit 40 includes a conveying belt 41 (conveying section), a first support roller 421, a second support roller 422, a third support roller 423, a pair of fourth support rollers 424, and a suction section 43. have

The conveying belt 41 is an endless belt that has a predetermined width in the front-rear direction and extends in the left-right direction. The conveying belt 41 is arranged to face the image forming section 50 and conveys the sheet S on the outer peripheral surface 411 in the sheet conveying direction A2. An image forming position where an image is formed on the sheet S by the image forming unit 50 is set on the revolving movement path of the conveying belt 41 .

The transport belt 41 is stretched over a first support roller 421 , a second support roller 422 , a third support roller 423 and a pair of fourth support rollers 424 . Inside the stretched conveying belt 41 , a suction portion 43 is arranged facing the inner peripheral surface 412 of the conveying belt 41 . The first support roller 421 is rotationally driven by a drive motor (not shown) to rotate the conveying belt 41 in a predetermined rotation direction. Further, the transport belt 41 has a plurality of suction holes penetrating in the thickness direction from the outer peripheral surface 411 to the inner peripheral surface 412 .

The suction unit 43 is arranged to face the image forming unit 50 with the conveying belt 41 interposed therebetween. The suction unit 43 causes the sheet S held on the outer circumferential surface 411 of the conveying belt 41 to generate a negative pressure between the conveying belt 41 and the conveying belt 41 , thereby bringing the sheet S into close contact with the outer circumferential surface 411 of the conveying belt 41 . The suction unit 43 includes a belt guide member 431 , a suction housing 432 , a suction device 433 and an exhaust duct 434 .

Between the first support roller 421 and the second support roller 422 , the belt guide member 431 guides the circular movement of the transport belt 41 interlocked with the rotation of the first support roller 421 .

The suction unit 43 generates a suction force by sucking air from the space above the conveyor belt 41 through the grooves and through holes formed in the belt guide member 431 and the suction holes of the conveyor belt 41 . Due to this suction force, an air current (suction wind) directed toward the suction section 43 is generated in the space above the conveying belt 41 . When the sheet S is conveyed onto the conveying belt 41 by the registration roller unit 30 and covers part of the outer peripheral surface 411 of the conveying belt 41 , a suction force (negative pressure) acts on the sheet S, causing the sheet S to move onto the conveying belt 41 . is in close contact with the outer peripheral surface 411 of the .

The suction housing 432 is a box-shaped housing with an upper opening, and is arranged below the conveying belt 41 so that the upper opening is covered by the belt guide member 431 . The suction housing 432 cooperates with the belt guide member 431 to define a suction space 432A.

An opening 432B is formed in the bottom wall of the suction housing 432, and a suction device 433 is arranged corresponding to the opening 432B. An exhaust duct 434 is connected to the suction device 433 . This exhaust duct 434 is connected to an exhaust port (not shown) provided in the apparatus main body 10 .

An image forming section 50 is arranged above the belt conveying unit 40 . The image forming unit 50 forms an image by performing an image forming process on the sheet S that is conveyed in the sheet conveying direction A2 while being held on the outer peripheral surface 411 of the conveying belt 41 . In this embodiment, the image forming method of the image forming unit 50 is an inkjet type, and an image is formed on the sheet S by ejecting ink droplets.

The image forming section 50 includes line heads 51 (51Bk, 51C, 51M, 51Y). The line head 51Bk ejects black ink droplets, the line head 51C ejects cyan ink droplets, the line head 51M ejects magenta ink droplets, and the line head 51Y ejects yellow ink droplets. do. The line heads 51Bk, 51C, 51M, and 51Y are arranged side by side from the upstream side toward the downstream side in the sheet conveying direction A1.

The line head 51 forms an image on the sheet S by ejecting ink droplets onto the sheet S conveyed in the sheet conveying direction A2 while being held on the outer peripheral surface 411 of the conveying belt 41 . Thus, an image is formed on the sheet S. As shown in FIG.

The sheet S on which an image is formed is conveyed by the conveying belt 41 and discharged (delivered) toward the curl correcting section 60 while being guided by the sheet discharge guide section 44 . The curl correcting section 60 is arranged on the downstream side of the conveying belt 41 in the sheet conveying direction A2 with the sheet discharge guide section 44 interposed therebetween. The curl correction unit 60 corrects the curl of the sheet S while conveying the sheet S on which the image is formed to the downstream side.

The sheet S whose curl has been corrected by the curl correcting section 60 is delivered to the second conveying path 12 . The second transport path 12 extends along the left side surface of the apparatus main body 10 . The sheet S sent to the second conveying path 12 is conveyed toward the discharge port 12A formed on the left side of the apparatus main body 10 by the second conveying roller pair 121 provided on the second conveying path 12, It is discharged onto the paper discharge section 14 from the paper discharge port 12A.

On the other hand, when double-sided printing is performed on the sheet S, the sheet S on which the image forming process for the first side (front side) has been completed is sent out from the second conveying path 12 to the sheet reversing section 15 . The sheet reversing section 15 is a conveying path branched in the middle of the second conveying path 12, and is a portion where the sheet S is reversed (switched back). The sheet S whose front and back sides have been reversed by the sheet reversing section 15 is delivered to the third conveying path 13 . The sheet S sent to the third conveying path 13 is reversely conveyed by the third conveying roller pair 131 provided on the third conveying path 13, and conveyed again through the registration roller section 30 in a state where the front and back are reversed. It is supplied onto the outer peripheral surface 411 of the belt 41 . The sheet S supplied onto the outer peripheral surface 411 of the conveying belt 41 in a state in which the front and back are reversed in this way is conveyed by the conveying belt 41 while being conveyed by the image forming section 50 to form the second surface opposite to the first surface. An image forming process is performed on the (back surface). The sheet S for which double-sided printing has been completed passes through the second conveying path 12 and is discharged onto the paper discharge section 14 from the paper discharge port 12A.

FIG. 2 is a cross-sectional view of the periphery of the pair of registration rollers and the cleaning unit 70 of the image forming apparatus 1 according to the present embodiment, and is a cross-sectional view of a state in which the cleaning unit 70 is arranged at the cleaning position.

The above-described registration roller section 30 has a registration housing 30H and a pair of registration rollers including an upper registration roller 31 (upper registration roller) and a lower registration roller 32 (transport roller, lower registration roller). The resist housing 30H is attached to the apparatus main body 10 and rotatably supports the upper resist roller 31 and the lower resist roller 32 . The sheet S is carried into the nip portion of the pair of registration rollers in the registration housing 30H as indicated by the arrow in FIG. The registration roller section 30 has a roller driving section (not shown) that drives the upper registration roller 31 and the lower registration roller 32 to rotate.

The upper registration roller 31 is a roller arranged on the upper side of the pair of registration rollers. The resist upper roller 31 is made of a metal roller.

The lower registration roller 32 is a roller arranged on the lower side of the pair of registration rollers. The resist lower roller 32 is composed of a rubber roller, and a PFA (polytetrafluoroethylene-perfluoroalkoxyethylene copolymer resin) tube is wound (fitted) on its outer peripheral surface.

As shown in FIG. 2, the straight line L connecting the center of the upper registration roller 31 and the center of the lower registration roller 32 is inclined at an acute angle (for example, 10 degrees) with respect to the vertical direction. In other words, the lower registration roller 32 is arranged at a position shifted upstream in the conveying direction of the sheet S with respect to the upper registration roller 31 .

Furthermore, the image forming apparatus 1 includes a cleaning device 7 . The cleaning device 7 can clean the surface of the lower resist roller 32 . The cleaning device 7 has a cleaning unit 70 and a moving mechanism 75 (see FIG. 14). The moving mechanism 75 has a function of moving the cleaning unit 70 between a cleaning position (FIG. 2), an attachment/detachment position (FIG. 24), and a separated position (FIG. 26).

3 to 5 are perspective views of the cleaning unit 70 of the image forming apparatus 1 according to this embodiment. FIG. 6 is a cross-sectional view of the cleaning unit 70 at cross-sectional position II in FIG. FIG. 7 is a front view showing the cleaning unit 70 with some members omitted. FIG. 8 is a perspective view showing the internal structure (cleaning section 70A) of the cleaning unit 70. As shown in FIG.

The cleaning unit 70 has a cleaning portion 70A and a cleaning housing 70H. The cleaning part 70A has a shape extending along the axial direction of the lower resist roller 32 and contacts the surface of the lower resist roller 32 from below to clean the surface.

The cleaning housing 70H supports the cleaning portion 70A. The cleaning housing 70H includes a front wall 701 and a rear wall 702 (pair of walls), a connection wall 703, a pair of unit fulcrum pins 70P (housing shaft), a seat member 704, and a pair of guide rollers 705 (guides). rollers) and A front wall 701, a rear wall 702 and a connection wall 703 of the cleaning housing 70H are made of a metal material (magnetic material).

The front wall 701 and the rear wall 702 are arranged to face each other in the front-rear direction (the axial direction of the lower resist roller 32) and support the cleaning section 70A. The connection wall 703 connects the front wall 701 and the rear wall 702 along the front-rear direction. The connection wall 703 has a side wall 703A and a bottom wall 703B (FIGS. 5 and 6). A pair of front and rear ribs 703T protrude from the bottom wall 703B (see FIGS. 19 and 20).

The pair of unit fulcrum pins 70P protrude in the front-rear direction from the outer side surfaces of the front wall 701 and the rear wall 702 (pair of wall portions). The unit fulcrum pin 70P is arranged at the lower left portions of the front wall 701 and the rear wall 702 . Each unit fulcrum pin 70P has a two-stage cylindrical shape with an outer diameter that decreases toward the tip.

A sheet member 704 is fixed to the bottom wall 703B so as to define the left side of the cleaning unit 70 (FIG. 6). The sheet member 704 prevents collected materials such as paper dust collected by the cleaning unit 70 from scattering toward the belt conveying unit 40 (FIG. 1).

The pair of guide rollers 705 are respectively supported by the front wall 701 and the rear wall 702 above the unit fulcrum pin 70P, and each include an outer peripheral surface rotatable around a central axis (second central axis) parallel to the front-rear direction. . The guide rollers 705 are arranged on the upper right portions of the front wall 701 and the rear wall 702 . The pair of guide rollers 705 has a function of guiding the cleaning unit 70 when the cleaning unit 70 moves to the attachment/detachment position, the separated position and the cleaning position.

The cleaning unit 70A includes a web W, a web driven roller 71 (delivering roller), a pressing roller 72, and a web driving roller 73 (winding roller) which are rotatably supported by a front wall 701 and a rear wall 702, respectively. , (FIGS. 6-8). The web W is made of a belt-shaped member having a contact surface capable of coming into contact with the surface of the lower registration roller 32, and is made of a cloth material such as non-woven fabric, for example. In this embodiment, as shown in FIGS. 6 and 8, a web roll WR in which the web W is wound in advance is fitted around the web driven roller 71 . The leading end of the web W is fixed to the outer peripheral surface of the web driving roller 73 after being put on the outer peripheral surface of the pressing roller 72 . The pressing roller 72 contacts the back surface of the web W and presses the front surface of the web W against the lower resist roller 32 . When the cleaning unit 70 is arranged at the cleaning position (FIG. 2) described above, the pressing roller 72 contacts the lower registration roller 32 with the web W therebetween. The web driven roller 71 feeds out the web W so that the portion of the web W that contacts the lower registration roller 32 changes, and the web drive roller 73 winds up the web W described above. As shown in FIG. 5, the state of the web roll WR held by the web driven roller 71 can be viewed from the outside of the cleaning unit 70 through an opening formed between the side wall 703A and the bottom wall 703B. can. Therefore, it is possible to prevent the cleaning unit 70 from being detached from the apparatus main body 10 during use and the amount of the web W that can be fed out to become small, from being erroneously attached to the apparatus main body 10 .

Further, the cleaning unit 70 has a unit input gear 711 (FIG. 4), an interlocking gear 711T, a transmission gear 712, and a driving roller gear 713 (FIG. 6).

The unit input gear 711 is rotatably supported at the lower end and right end of the front wall 701 . An input gear shaft 711S of the unit input gear 711 penetrates the front wall 701 and extends inside (rear side) of the front wall 701 . The interlocking gear 711T is fixed to the input gear shaft 711S and rotates integrally with the unit input gear 711 .

The transmission gear 712 is rotatably supported inside the front wall 701 and is engaged with the interlocking gear 711T and the driving roller gear 713, respectively. Drive roller gear 713 is a gear fixed to one end of web drive roller 73 .

FIG. 9 is a perspective view of the cleaning unit 70 and the web delivery mechanism 81 of the image forming apparatus 1 according to this embodiment. 10 and 11 are enlarged perspective views enlarging a part of the cleaning unit 70. FIG.

The cleaning device 7 further includes a web delivery mechanism 81 (web drive mechanism) and a controller 90 . The web delivery mechanism 81 is attached to the apparatus main body 10 of the image forming apparatus 1 . The web delivery mechanism 81 has a function of delivering the web W of the cleaning unit 70 . The web delivery mechanism 81 is connected to the cleaning unit 70 by arranging the cleaning unit 70 at the cleaning position. The web delivery mechanism 81 has a solenoid 811 , a rotating arm 812 , a third detection sensor 813 , a transmission gear 814 and a transmission gear 815 .

The solenoid 811 generates a driving force for moving the web W by receiving a command signal from the control section 90 . The solenoid 811 includes a retractable shaft 811S. The retractable shaft 811S retracts with respect to the main body of the solenoid 811. As shown in FIG. The solenoid 811 is supported by a drive frame (not shown) made of sheet metal arranged inside the apparatus main body 10 .

The rotating arm 812 is rotatably supported by a shaft 812S (FIG. 9) provided in the drive frame inside the apparatus main body 10. As shown in FIG. The shaft 812S is supported by the drive frame so as to be rotatable around a rotation center axis extending in the front-rear direction. The rotating arm 812 has a first arm portion 812A and a second arm portion 812B. The first arm portion 812A extends rightward from the rotation center axis of the rotating arm 812 . A distal end portion of the first arm portion 812A is connected to the retractable shaft 811S. The second arm portion 812B extends downward from the rotation center axis of the rotating arm 812 on the side opposite to the first arm portion 812A. A detection piece 812C is arranged at the tip (lower end) of the second arm portion 812B. Further, the rear end portion of the shaft 812S is provided with a gear portion 812T capable of integrally rotating with the shaft 812S. Further, the web delivery mechanism 81 has a first one-way clutch and a second one-way clutch (both not shown). The first one-way clutch is fixed inside the rotating arm 812 and fitted on the shaft 812S. Also, the second one-way clutch is fixed to the drive frame so as to be adjacent to the first one-way clutch and is fitted on the shaft 812S.

A third detection sensor 813 is fixed to the left end of the main body of the solenoid 811 . The third detection sensor 813 is a PI sensor that detects movement (rotation) of the detection piece 812C. The controller 90 can detect the feed amount of the web roll WR according to the number of detections of the detection piece 812</b>C output from the third detection sensor 813 . Further, when the number of times of detection reaches a preset threshold number of times, the control section 90 causes the display section (not shown) of the image forming apparatus 1 to display a replacement message for the cleaning unit 70 .

The transmission gear 814 is rotatably supported by the device main body 10 and is engaged with the gear portion 812T. Incidentally, the transmission gear 814 consists of a two-stage gear. Similarly, the transmission gear 815 is rotatably supported by the apparatus main body 10, engages with the rear gear portion of the two-stage gear of the transmission gear 814, and engages with the aforementioned unit input gear 711. are doing.

9 shows a state in which the retractable shaft 811S is retracted (contracted) with respect to the main body of the solenoid 811. FIG. When the controller 90 inputs a command signal to the solenoid 811 from the state of FIG. 9, the retractable shaft 811S protrudes (extends) from the main body of the solenoid 811, so that the rotating arm 812 rotates in the opposite direction of FIG. 9 around the shaft 812S. Rotate clockwise. At this time, since the rotating arm 812 rotates relative to the shaft 812S due to the action of the first one-way clutch, the shaft 812S does not rotate. On the other hand, when sending out the web W by a predetermined amount, the control section 90 inputs a command signal to the solenoid 811 to contract the projecting/retracting shaft 811S with respect to the main body of the solenoid 811 . As a result, the rotating arm 812 rotates clockwise in FIG. 9 around the shaft 812S. At this time, the shaft 812S rotates integrally with the rotating arm 812 by a predetermined angle due to the action of the first one-way clutch. As a result, the rotational driving force is input to the unit input gear 711 via the transmission gears 814 and 815 from the gear portion 812T fixed to the shaft 81S. Then, the rotational driving force is further transmitted to the unit input gear 711, the interlocking gear 711T, the transmission gear 712, and the driving roller gear 713 of the cleaning unit 70, and the web driving roller 73 rotates by a preset rotation angle, and the web W moves to be taken up by the web drive roller 73 . As a result, the portion of the contact surface of the web W that faces the lower registration roller 32 changes. It should be noted that every time the rotating arm 812 rotates one reciprocating motion, the third detection sensor 813 detects the detection piece 812C, thereby detecting that the unit input gear 711 rotates and the web W moves.

When the web W moves, the controller 90 inputs a command signal to the solenoid 811 to project the projecting/retracting shaft 811S from the main body of the solenoid 811 again. At this time, reverse rotation of the shaft 812S is prevented by the action of the aforementioned second one-way clutch. Further, as shown in FIG. 11, the one-way clutch 73T provided on the drive roller shaft 73S of the web drive roller 73 functions to prevent the web drive roller 73 from rotating in the reverse direction. Therefore, every time the control unit 90 performs the retracting motion of the retracting shaft 811S, the web W moves toward the web driving roller 73 by a predetermined amount. As described above, in this embodiment, it is possible to feed the web W from the web roll WR using a slight retraction stroke of the retraction shaft 811S of the solenoid 811 . In another embodiment, the web delivery mechanism 81 may rotate the web driven roller 71 in addition to the web drive roller 73 .

9, the pressure roller shaft 72S of the pressure roller 72 is provided with a torque limiter 72T. When the web W (pressing roller 72) of the cleaning device 7 is in contact with the lower resist roller 32 and the sheet S is sandwiched between the upper resist roller 31 and the lower resist roller 32, the sheet S is jammed in the image forming apparatus 1. may occur. In this case, the user opens a predetermined cover of the apparatus main body 10 of the image forming apparatus 1 and pulls out the sheet S in the direction opposite to the arrow in FIG. and try to remove the sheet S jammed between. At this time, when the force for pulling out the sheet S is transmitted from the lower registration roller 32 to the pressing roller 72 , the web W is excessively fed from the pressing roller 72 to the web drive roller 73 side. In the present embodiment, since the pressure roller shaft 72S is provided with the torque limiter 72T, when a sudden rotational force is applied to the pressure roller 72, the rotation of the pressure roller 72 is locked, and the web W is fed out. prevented.

Further, referring to FIG. 10, in the present embodiment, a brake spring 71T is interposed between an E-ring 71R1 and a flange 71R2 in a compressed and deformed state on the driven roller shaft 71S of the web driven roller 71. . 10, illustration of the front wall 701 of FIG. 9 is omitted. The flange 71R2 is a ring-shaped flange fixed to the pressing roller shaft 72S of the pressing roller 72. As shown in FIG. A rear end portion of the brake spring 71T is in contact with the flange 71R2. A front end portion of the brake spring 71T is in contact with the rear surface of the front wall 701 . As a result, the compressive force of the brake spring 71T is applied to the pressing roller 72 via the flange 71R2, preventing the pressing roller 72 from rotating unnecessarily. As a result, the web W is prevented from being let out from the pressing roller 72 even though the control unit 90 does not control the solenoid 811 .

The moving mechanism 75 (FIG. 2) moves the cleaning unit 70 to a cleaning position (FIG. 2), an attachment/detachment position (FIG. 24) below the cleaning position, and a separated position (FIG. 26) between the cleaning position and the attachment/detachment position. ) can be moved between The moving mechanism 75 allows the cleaning section 70A to abut against the lower resist roller 32 at the cleaning position, and the cleaning section 70A is spaced downward from the lower resist roller 32 at the attachment/detachment position, and the cleaning unit 70 is allowed to be attached to and detached from the apparatus main body 10 . At the separated position, the cleaning section 70A is arranged below the resist lower roller 32 and separated from the cleaning unit 70, and the connection between the cleaning unit 70 and the web delivery mechanism 81 (web drive mechanism) is released.

FIG. 12 is a perspective view showing a state in which the conveying unit frame 40H is detached from the body frame 100 forming the device body 10 of the image forming apparatus 1 according to this embodiment. FIG. 13 is a perspective view showing how the transport unit frame 40H is attached to the body frame 100. As shown in FIG. 14 and 15 are perspective views of the transport unit frame 40H.

The belt transport unit 40 (transport unit) shown in FIG. 1 further has a transport unit frame 40H. The transport unit frame 40H integrally includes the transport belt 41, a first support roller 421, a second support roller 422, a third support roller 423, a pair of fourth support rollers 424, and a suction unit 43. supported by The transport unit frame 40H can be attached to the body frame 100 of the apparatus body 10 along a first direction (backward direction) parallel to the front-rear direction (the axial direction of the lower registration roller 32), and can be mounted from the body frame 100 to the first direction. It is detachable along a second direction (forward direction) opposite to the first direction.

14 and 15, transport unit frame 40H includes front frame 401, rear frame 402, left frame 403, first right frame 404A (upper connection frame), and second right frame 404B (lower connection frame). side connection frame), a pair of front and rear magnets 404C (magnetic members), and a pair of left and right rail portions 40R.

The front frame 401 is a frame arranged on the front part of the transport unit frame 40H. As shown in FIGS. 14 and 15, the front frame 401 is provided with a front cover 401A. The front cover 401A forms part of the front surface of the apparatus body 10. As shown in FIG. The rear frame 402 is a frame arranged on the rear surface portion of the transport unit frame 40H, and is arranged to face the front frame 401 in the front-rear direction. The left frame 403 is arranged at the left end of the transport unit frame 40H and connects the front frame 401 and the rear frame 402 along the front-rear direction. Also, the first right frame 404A and the second right frame 404B are arranged at the right end of the transport unit frame 40H, and connect the front frame 401 and the rear frame 402 along the front-rear direction. The first right frame 404A is arranged along the upper surface of the transport unit frame 40H, and the second right frame 404B is arranged below the first right frame 404A. Both ends of the first right frame 404A and the second right frame 404B in the front-rear direction are connected to each other along the vertical direction by a pair of side plates (not shown) arranged inside the front frame 401 and the rear frame 402. ing. As a result, a rectangular frame structure is formed by the first right frame 404A, the second right frame 404B, and the pair of side plates. The pair of left and right rail portions 40</b>R are rail portions for allowing the transport unit frame 40</b>H to slide in the front-rear direction with respect to the main body frame 100 . Although only the right rail portion 40R is shown in FIGS. 14 and 15, a similar rail portion 40R is also arranged at the left end portion of the transport unit frame 40H. The pair of magnets 404C are magnets that are spaced apart in the front-rear direction on the upper surface of the second right frame 404B. A pair of magnets 404</b>C has a function of holding the cleaning unit 70 .

As shown in FIGS. 14 and 15, the transport unit mounting portion 40A is formed on the left side of the first right frame 404A and the second right frame 404B in the transport unit frame 40H. The transport belt 41, the first support roller 421, the second support roller 422, the third support roller 423, the pair of fourth support rollers 424, the suction unit 43, and the like are arranged in the transport unit mounting portion 40A. On the other hand, in the space between the first right frame 404A and the second right frame 404B, a cleaning unit mounting portion 40B (unit housing portion) is arranged. The cleaning unit mounting portion 40B accommodates the cleaning unit 70 described above, which is arranged at the mounting/demounting position, and allows the cleaning unit 70 to be mounted. The cleaning unit mounting portion 40B constitutes a part of the moving mechanism 75. As shown in FIG.

Further, the transport unit frame 40H has a cleaning unit rotating portion 45 and a rotating input gear 40G. FIG. 16 is a perspective view of the cleaning unit rotating portion 45 of the transport unit frame 40H according to this embodiment. 17 and 18 are enlarged perspective views enlarging a part of the cleaning unit rotating portion 45. FIG.

As shown in FIGS. 14 and 15, the cleaning unit rotating portion 45 is supported by the pair of side plates immediately below the first right frame 404A. 16, the cleaning unit rotating portion 45 includes a rotating shaft 451, a pair of front and rear bearings 451S, a rotating gear 452, a pair of front and rear lever support portions 453 (fixing members), and a pair of front and rear lever support portions 453 (fixing members). It has a rotating lever 454 (support member) and a pair of front and rear coil springs 455 (spring members).

The rotating shaft 451 is rotatably supported by the pair of side plates via a pair of front and rear bearings 451S. The rotating shaft 451 extends in the front-rear direction (the axial direction of the lower registration roller 32 ) and forms a central axis (first central axis) for rotation of the pair of rotating levers 454 . The rotating gear 452 is a gear fixed to the rear end portion of the rotating shaft 451 and is engageable with the rotating input gear 40G.

A pair of front and rear rotating levers 454 are arranged in the cleaning unit mounting portion 40B, and support the cleaning housing 70H of the cleaning unit 70 so as to sandwich the cleaning housing 70H from both sides in the front-rear direction (the axial direction of the lower registration roller 32). is possible. 17 and 18, each rotating lever 454 has a lever bottom portion 454A, a first lever side portion 454B, and a second lever side portion 454C. The lever bottom portion 454A includes a surface parallel to the axial direction of the rotating shaft 451 and extends in the radial direction of the rotating shaft 451 . The first lever side portion 454B and the second lever side portion 454C are walls erected from the front and rear side edges of the lever bottom portion 454A, and are arranged perpendicular to the axial direction of the rotating shaft 451, respectively. . The second lever side portion 454C has a substantially rectangular shape slightly larger than the outer diameter of the rotating shaft 451, and the first lever side portion 454B is larger than the rotating shaft 454C. It extends radially from 451.

The first lever side portion 454B and the second lever side portion 454C are each provided with a hole through which the rotating shaft 451 is inserted. As a result, the rotating lever 454 is rotatably supported by the rotating shaft 451 .

Further, the first lever side portion 454B is formed with a pin receiving portion 454P (shaft support portion) and a notch portion 454Q. The pin receiving portion 454P has a shape in which the side edge of the first lever side portion 454B is cut into an elongated hole shape. The pin receiving portion 454P receives the unit fulcrum pin 70P (FIGS. 3 and 4) of the cleaning unit 70 along a direction perpendicular to the front-rear direction (the axial direction of the lower registration roller 32) and enables the unit fulcrum pin 70P to rotate. It has a supporting function. The cutout portion 454Q has a substantially rectangular cutout shape on the side edge of the first lever side portion 454B between the pin receiving portion 454P and the rotating shaft 451 .

The pair of front and rear lever support portions 453 are fixed to the rotating shaft 451 by screws V so as to be able to hold the pair of rotating levers 454 respectively. The lever support portion 453 has a support protrusion 453A arranged in the notch portion 454Q so as to extend in the front-rear direction. The tip of the support projection 453A has a bent shape perpendicular to the body of the lever support 453 .

17 and 18, a pair of front and rear coil springs 455 are arranged so as to be interposed between a lever support portion 453 and a rotating lever 454, respectively. Specifically, each coil spring 455 has a first spring end 455A and a second spring end 455B. The first spring end portion 455A is locked to the upper surface portion of the support projection portion 453A. Also, the second spring end portion 455B is engaged with the lower surface portion of the lever bottom portion 454A of the rotating lever 454 . As a result, the coil spring 455 allows the rotating lever 454 to rotate relative to the lever support portion 453 about the central axis (first central axis) of the rotating shaft 451 within a predetermined allowable angle range. In addition, they are interposed between the rotating lever 454 and the lever support portion 453 so as to be elastically deformable. When no external force is applied to the lever support portion 453 and the rotating lever 454, the elastic force of the coil spring 455 changes the relative positions of the lever supporting portion 453 and the rotating lever 454 in the circumferential direction (rotational direction). Regulated. In other words, in FIGS. 17 and 18, when the position of the rotating lever 454 is fixed, the lever support portion 453 and the rotating shaft 451 elastically deform the coil spring 455 with respect to the rotating lever 454. It can rotate relative to the rotating lever 454 .

Further, the cleaning device 7 has a rotation driving portion 75K. The rotation driving section 75K constitutes a part of the moving mechanism 75. As shown in FIG. The rotation driving portion 75K is configured to move the cleaning unit 70 between the cleaning position and the attachment/detachment position while the pair of unit fulcrum pins 70P are supported by the pair of pin receiving portions 454P. The moving lever 454 is rotated around the central axis (first central axis) of the rotating shaft 451 . Note that the central axis is arranged above the pin receiving portion 454P in FIG. In addition, the rotation driving portion 75K rotates the pair of unit fulcrum pins 70P relative to the pair of pin receiving portions 454P so that the cleaning unit 70 maintains a posture in which the cleaning portion 70A (web W) of the cleaning unit 70 faces upward. The pair of rotating levers 454 are rotated while permitting relative rotation with each other.

The rotation driving section 75K has a unit driving section 80 (FIG. 2) (driving section) in addition to the cleaning unit rotating section 45 described above. The unit driving section 80 generates driving force for rotating the rotating shaft 451 of the cleaning unit rotating section 45 around its central axis.

Referring to FIG. 2 , unit drive section 80 includes a motor (not shown) including drive motor output shaft 801 , pulse plate 802 , first detection sensor 803 , second detection sensor 804 , and unit drive output gear 805 . (FIG. 24). Rotational driving of the motor is controlled by the controller 90 described above.

The pulse plate 802 is fixed to the drive motor output shaft 801 and rotates together with the drive motor output shaft 801 . A first detection sensor 803 detects the amount of rotation of the pulse plate 802 . Specifically, the first detection sensor 803 has a light-emitting portion that emits detection light and a light-receiving portion that receives the detection light. A plurality of slits are formed in the pulse plate 802 at intervals along the direction of rotation thereof. As the pulse plate 802 rotates, the detected light is blocked by the slit, and the light receiving unit outputs a signal corresponding to the waveform to the control unit 90, thereby driving the drive motor output shaft 801 (the pair of rotating levers 454). is detected.

The second detection sensor 804 is composed of a known PI sensor and detects that the cleaning unit 70 is placed at the cleaning position shown in FIG. In this embodiment, the cleaning unit 70 is detected by the second detection sensor 804 when a part of the cleaning housing 70H of the cleaning unit 70 enters between the light emitting portion and the light receiving portion of the second detection sensor 804 .

The unit driving output gear 805 transmits the rotational driving force generated by the motor of the unit driving section 80 to the rotation input gear 40G of the cleaning unit rotating section 45 . In this embodiment, when the transport unit frame 40H is attached to the main body frame 100, the rotation input gear 40G and the unit driving output gear 805 are engaged with each other to enable transmission of rotational driving force.

19 is a sectional view showing how the cleaning unit 70 is attached to the transport unit frame 40H according to this embodiment, and FIG. 20 is a sectional view showing how the cleaning unit 70 is attached to the transport unit frame 40H. is. 21 and 22 are enlarged perspective views showing how the cleaning unit 70 is attached to the transport unit frame 40H. FIG. 23 is a perspective view showing how the cleaning unit 70 is attached to the transport unit frame 40H. FIG. 24 is a cross-sectional view of the periphery of the pair of registration rollers and the cleaning unit 70 of the image forming apparatus 1, and is a cross-sectional view showing a state in which the cleaning unit 70 is arranged at the attachment/detachment position. It is the same sectional view in the state pushed up slightly from the attachment or detachment position. FIG. 26 is a cross-sectional view of the periphery of the pair of registration rollers and the cleaning unit 70 of the image forming apparatus, and is a cross-sectional view in which the cleaning unit 70 is arranged at the separated position. FIG. 27 is a cross-sectional perspective view of the cleaning unit 70 arranged at the attachment/detachment position. FIG. 28 is a cross-sectional perspective view of the cleaning unit 70 arranged at the cleaning position. FIG. 29 is a cross-sectional perspective view of the cleaning unit 70 arranged at the attachment/detachment position. FIG. 30 is a cross-sectional perspective view of the cleaning unit 70 arranged at the cleaning position. FIG. 31 is a cross-sectional view of the cleaning unit 70 arranged at the cleaning position.

Referring to FIG. 24, moving mechanism 75 further has a guide portion 100G. The guide portion 100G allows the pair of guide rollers 705 to come into contact with the rotation of the pair of rotation levers 454 about the first central axis, and moves the cleaning unit 70 between the cleaning position and the attachment/detachment position. guide between The guide portion 100G has a pair of front and rear first guide surfaces 101R and a pair of front and rear second guide surfaces 102R. The pair of front and rear first guide surfaces 101</b>R are formed from the left side surfaces of the pair of front and rear guide frames 101 provided on the body frame 100 . The first guide surface 101R is inclined so as to guide the cleaning unit 70 (guide roller 705) to the right as it advances upward. Similarly, the pair of front and rear second guide surfaces 102R are formed by parts of the pair of front and rear registration frames 102 (FIG. 27) provided on the body frame 100, respectively. The second guide surface 102R is slightly inclined so as to guide the cleaning unit 70 (guide roller 705) to the left as it advances upward.

Further, the moving mechanism 75 has a pair of front and rear positioning portions 102S. The positioning portion 102S contacts the guide roller 705 of the cleaning unit at the cleaning position, and positions the cleaning unit 70 so that the web W of the cleaning portion 70A can clean the lower resist roller 32. FIG. As shown in FIG. 24, the positioning portion 102S is connected to the second guide surface 102R and has an arc shape along the outer peripheral surface of the guide roller 705. As shown in FIG. In addition, in FIG. 24, respective members on the rear side of the pair of front and rear first guide surfaces 101R, second guide surfaces 102R, and positioning portion 102S are shown.

As shown in FIG. 12, when the transport unit frame 40H is pulled forward from the body frame 100 of the apparatus body 10, the operator can mount the cleaning unit 70 on the cleaning unit mounting portion 40B of the transport unit frame 40H. At this time, as shown in FIG. 19, the pair of rotating levers 454 are arranged so as to extend downward from the rotating shaft 451 (first central shaft), and the pin receiving portion 454P is located on the right side of the rotating lever 454 (in the width direction). (one end side in the width direction) is obliquely notched toward the left side (the other end side opposite to the one end side in the width direction) and downward. Therefore, the operator can insert and fit the pair of left and right unit fulcrum pins 70P of the cleaning unit 70 into the pin receiving portions 454P from above while gripping the side wall 703A and the bottom wall 703B (FIG. 6) of the cleaning unit 70. (Fig. 20). At this time, the aforementioned unit input gear 711 is arranged behind the unit fulcrum pin 70P on the front side of the cleaning unit 70 (FIG. 21). 22, the unit fulcrum pin 70P on the rear side of the cleaning unit 70 is fitted into the pin receiving portion 454P.

When the pair of unit fulcrum pins 70P of the cleaning unit 70 are fitted into the pin receiving portions 454P of the pair of rotating levers 454 by an operator, the bottom wall 703B of the cleaning housing 70H is arranged to face the pair of magnets 404C. , and a pair of ribs 703T abut on the upper surface of the second right frame 404B. As a result, the cleaning unit 70 is held by the second right frame 404B by the magnetic field generated by the pair of magnets 404C in addition to the pair of rotating levers 454. As shown in FIG. Therefore, even if the operator lets go of the cleaning unit 70, the cleaning unit 70 is prevented from falling off the transport unit frame 40H.

As described above, when the cleaning unit 70 is attached to the cleaning unit attachment portion 40B (attachment position) of the transport unit frame 40H, the operator inserts the transport unit frame 40H into the body frame 100 (FIG. 23). As a result, the cleaning unit 70 is inserted into the body frame 100, and the rotation input gear 40G of the transport unit frame 40H is engaged with the unit drive output gear 805 of the unit drive section 80 inside the body frame 100. FIG. Also, at this time, the pair of front and rear guide rollers 705 of the cleaning unit 70 are arranged to face the first guide surfaces 101R of the pair of front and rear guide portions 100G at a predetermined interval in the left-right direction.

As shown in FIG. 24, when the cleaning unit 70 arranged at the attachment/detachment position is viewed from a direction parallel to the axial direction of the lower registration roller 32, the center (P2) of the unit fulcrum pin 70P supported by the pin receiving portion 454P is , is arranged below and to the right of the central axis (P1) of the rotating shaft 451 (one end side in the width direction). Further, the center of gravity (J) of the cleaning unit 70 is arranged on the right side of the unit fulcrum pin 70P. In this embodiment, the shaft of the pressing roller 72 of the cleaning unit 70 is made of metal (for example, a SUS material with a diameter of 10 mm) and the surface of the pressing roller 72 is an EPDM sponge roller. The center of gravity of 70 is eccentric to the right side of cleaning unit 70 so as to be located further right than the center (P4) of pressing roller 72 . Further, the center (P3) of the magnet 404C in the left-right direction (width direction) is arranged on the right side of the center (P2) of the unit fulcrum pin 70P (the leading end in the moving direction of the cleaning unit 70 in the left-right direction).

From the state shown in FIG. 24, the control section 90 controls the unit drive section 80, and the rotation drive section 75K rotates the pair of rotation levers 454 around the rotation shaft 451 (arrow D251 in FIG. 25). At this time, the left end of the bottom wall 703B moves upward as the unit fulcrum pin 70P moves (arrow D252 in FIG. 25). As a result, the distance between the left end of the bottom wall 703B and the magnet 404C is increased, so that the influence of the magnetic binding force by the magnet 404C is reduced, and the bottom wall 703B of the cleaning unit 70 can be easily separated from the magnet 404C. can. After that, when the cleaning unit 70 tilts to the right around the unit fulcrum pin 70P due to its own weight (arrow D253 in FIG. 25), the pair of guide rollers 705 move along the first guide surfaces 101R of the pair of guide portions 100G. abut each other. In FIG. 25, since the guide roller 705 is hidden behind the rear wall 702, the contact portion between the guide roller 705 and the first guide surface 101R cannot be seen. , the guide roller 705 is in contact with the first guide surface 101R.

Thereafter, when the controller 90 further rotates the pair of rotating levers 454, the cleaning unit 70 moves upward and rightward while the pair of guide rollers 705 are guided by the first guide surface 101R. At this time, the locus of rotation of the pivot lever 454 and the locus of movement of the cleaning unit 70 guided by the first guide surface 101R are different from each other. In this embodiment, a pair of unit fulcrum pins 70P of the cleaning unit 70 are supported so as to be relatively rotatable with respect to the pin receiving portion 454P of the rotating lever 454. As shown in FIG. Therefore, as shown in FIGS. 25 and 26, the posture of the cleaning unit 70 can be changed as it moves upward, so that the cleaning unit 70 can move smoothly according to the rotation of the rotating lever 454. can rise to

In the state shown in FIG. 26, the pair of guide rollers 705 are transferred from the first guide surface 101R to the second guide surface 102R. Then, when the control unit 90 further rotates the rotating lever 454, the pair of guide rollers 705 are soon fitted into the pair of positioning portions 102S (FIG. 31). At this time, as shown in FIG. 2, the pressure roller 72 of the cleaning section 70A of the cleaning unit 70 is moved downward to the lower registration roller 32 along a straight line L connecting the center of the upper registration roller 31T and the center of the lower registration roller 32. abut from At this time, the rotating lever 454 extends obliquely downward from the rotating shaft 451 so as to cross the vertical direction at an acute angle (see FIG. 28). Therefore, the unit fulcrum pin 70P is prevented from being detached from the pin receiving portion 454P. 2, 28, 30, and 31, the pressing roller 72 presses the web W against the lower registration roller 32, thereby It is possible to clean pigments and paper dust adhering to the surface of the In the posture of the cleaning unit 70 at the cleaning position shown in FIG. 2, the center of gravity (pressing roller 72) of the cleaning unit 70 is arranged directly above the unit fulcrum pin 70P, so the posture of the cleaning unit 70 at the cleaning position is stable. and maintained. Further, the control section 90 keeps applying an exciting current to the motor of the unit driving section 80, so that the cleaning unit 70 can be held at the cleaning position without rotating the rotating lever 454 in the reverse direction. In another embodiment, a lock mechanism for locking the cleaning unit 70 in the cleaning position and an unlocking mechanism for releasing the lock and allowing the cleaning unit 70 to move from the cleaning position to the attachment/detachment position may be provided.

As described above, in this embodiment, the cleaning device 7 has the cleaning unit 70 and the moving mechanism 75 and cleans the surface of the lower resist roller 32 . The moving mechanism 75 is capable of moving the cleaning unit 70 at least between the cleaning position and the attachment/detachment position. Therefore, when the moving mechanism 75 places the cleaning unit 70 at the cleaning position, the cleaning portion 70A of the cleaning unit 70 is moved to the resist position. While the lower roller 32 can be cleaned, when the moving mechanism 75 disposes the cleaning unit 70 at the attachment/detachment position below the cleaning position, the cleaning section 70A is spaced downward from the resist lower roller 32, and the cleaning unit 70 is placed in the apparatus. It can be attached to and detached from the main body 10 . As a result, the cleaning unit 70 can be detached from the apparatus main body 10 without applying a large load to the lower registration roller 32 . Further, the cleaning unit 70 can be moved between the attachment/detachment position and the cleaning position simply by rotating the pair of rotating levers 454 around the rotating shaft 451 (first central axis) by the rotating drive section 75K. can. At this time, the pair of unit fulcrum pins 70P rotate relative to the pair of pin receiving portions 454P, so that the cleaning unit 70 can maintain the posture in which the pressing roller 72 (web W) of the cleaning portion 70A faces upward. can. Therefore, at the same time that the cleaning unit 70 reaches the cleaning position and contacts the positioning portion 102S, the pressing roller 72 of the cleaning portion 70A can contact the lower resist roller 32 from below.

In addition, in this embodiment, since the cleaning housing 70H has a pair of guide rollers 705, the pair of guide rollers 705 and the pair of guide rollers 705 and the pair of guide rollers 705 are rotated according to the rotation of the pair of rotation levers 454 by the rotation drive section 75K. The guide portion 100G can stably guide the cleaning unit 70 between the attachment/detachment position and the cleaning position.

2, in the present embodiment, the lower registration roller 32 is arranged below the upper registration roller 31 and shifted to the right side of the upper registration roller 31 (the upstream side in the conveying direction of the sheet S). be done. As a result, the sheet S can be stably conveyed toward the image forming position arranged at a position lower than the registration roller pair. On the other hand, the cleaning unit mounting portion 40B provided in the transport unit frame 40H is positioned below the pair of registration rollers and on the left side of the pair of registration rollers (on the upstream side in the sheet transport direction). When moving the cleaning unit 70 from the attachment/detachment position arranged in the cleaning unit mounting portion 40B to the cleaning position directly below the lower registration roller 32, a straight line connecting the center of the upper registration roller 31 and the center of the lower registration roller 32 is drawn. In order to bring the pressing roller 72 into contact with the lower registration roller 32 along L, a complicated moving mechanism is usually required. In particular, in order to move the cleaning unit 70 linearly, after linearly moving the cleaning unit 70 to an intermediate position to the right of the attachment/detachment position, the cleaning unit 70 is moved upward and to the left from the intermediate position. It is necessary to move along a straight line L toward In this case, multiple linear movement paths that intersect each other are required.

On the other hand, in this embodiment, the movement of the cleaning unit 70 between the attachment/detachment position and the cleaning position as described above is realized by the rotation of the pair of rotation levers 454 and the guide function of the guide portion 100G. In particular, the rotating lever 454 moves the cleaning unit 70 rightward and upward from the attachment/detachment position toward the cleaning position. On the other hand, the pair of guide portions 100G guide the guide rollers 705 of the cleaning unit 70 upward so that the movement trajectory of the pressing roller 72 of the cleaning unit 70 differs from the rotation trajectory of the rotation lever 454. The pressing roller 72 is arranged so that it reaches the lower resist roller 32 through a shorter trajectory. In order to prevent the cleaning unit 70 from contacting the lower registration roller 32 along the straight line L and preventing the cleaning unit 70 from interfering with the rotation of the rotation lever 454, the cleaning unit 70 is rotated while the rotation lever 454 is rotating. , the unit fulcrum pin 70</b>P can rotate relative to the rotating lever 454 . With such a configuration, the cleaning unit 70 can be moved between the attachment/detachment position and the cleaning position in the limited space below the registration roller pair, and the pressing roller 72 can move along the straight line L to the registration position. It can be brought into contact with and separated from the lower roller 32 . In addition, since the cleaning unit mounting portion 40B provided in the transport unit frame 40H can be arranged on the left side of the pair of registration rollers (toward the belt transport unit 40) instead of being placed directly below the pair of registration rollers, the transport unit frame 40H can be arranged. Of these, the cleaning unit mounting portion 40B is provided in a limited space adjacent to the transport unit mounting portion 40A, so that the transport unit frame 40H can be made compact.

Further, in this embodiment, the rotating lever 454 has a pin receiving portion 454P for receiving the unit fulcrum pin 70P. Then, the rotary driving section 75K rotates the pair of rotary levers 454 around the rotary shaft 451 so that the unit fulcrum pin 70P moves rightward and upward from the state in which the cleaning unit 70 is arranged at the attachment/detachment position. By rotating, the cleaning unit 70 is moved to the cleaning position. With such a configuration, in the attachment/detachment position, the pair of unit fulcrum pins 70P of the cleaning unit 70 can be easily inserted into and removed from the pin receiving portions 454P of the pair of rotating levers 454 along the direction perpendicular to the axial direction. can. Further, the cleaning unit 70 can be stably moved to the cleaning position above the attachment/detachment position in a state in which the pair of unit fulcrum pins 70P are fitted in the pair of pin receiving portions 454P by the weight of the cleaning unit 70.

Further, in the present embodiment, when the rotation driving portion 75K rotates the pair of rotation levers 454 around the rotation shaft 451 at the attachment/detachment position, the cleaning unit 70 is tilted by its own weight, and the pair of guide rollers 705 are connected to each other. are in contact with the guide portions 100G. Therefore, it is possible to stably and smoothly move the cleaning unit 70 from the attachment/detachment position to the cleaning position without requiring another driving mechanism for bringing the pair of guide rollers 705 into contact with the pair of guide portions 100G. can.

Also, in this embodiment, at least one magnet 404C is arranged on the second right frame 404B. Therefore, the magnetic binding force of the magnet 404C prevents the cleaning unit 70 from falling off from the cleaning unit mounting portion 40B.

Further, the center of the magnet 404C in the left-right direction is arranged on the right side (downstream in the movement direction of the cleaning unit 70) of the center of the rotating lever 454 supported by the pin receiving portion 454P. Therefore, when the rotation drive section 75K rotates the pair of rotation levers 454, the bottom wall 703B of the cleaning unit 70 tilts, thereby reducing the influence of the magnetic binding force of the magnet 404C on the bottom wall 703B. so that the cleaning unit 70 can be easily moved toward the cleaning position.

Further, in this embodiment, the cleaning unit rotating portion 45 has a pair of coil springs 455 . Therefore, even if the unit driving section 80 rotates the rotating shaft 451 after the cleaning unit 70 abuts on the positioning section 102S, application of a large load to the pair of lever supporting sections 453 is suppressed. As a result, the need to control the driving amount of the unit drive section 80 to reach the cleaning position with high accuracy is reduced.

Further, in the present embodiment, the surface of the lower resist roller 32 can be cleaned by the belt-like web W. FIG. Further, even if the surface of the web W becomes dirty, the rotation of the web drive roller 73 causes the web driven roller 71 to let out the web W, and the surface of the lower registration roller 32 can be cleaned by a new contact surface.

Further, in the present embodiment, when the cleaning unit mounting portion 40B is arranged on the conveying unit frame 40H and the cleaning unit 70 is arranged at the attachment/detachment position, the cleaning unit 70 and the belt conveying unit 40 are attached to the apparatus main body 10 integrally. It is attachable and detachable. Therefore, the cleaning unit 70 can be easily attached to and detached from the apparatus main body 10 as well as the belt conveying unit 40 that conveys the sheet S can be attached to and detached from the apparatus main body 10 .

Further, in this embodiment, the transport unit frame 40H has a first right frame 404A and a second right frame 404B. Therefore, the rigidity of the right portion of the transport unit frame 40H can be kept high. Also, the space below the first right frame 404A (the space between the first right frame 404A and the second right frame 404B) can be used to form the cleaning unit mounting portion 40B. Then, the rotation driving portion 75K moves the cleaning unit 70 rightward (horizontal direction orthogonal to the axial direction of the lower registration roller 32) from the cleaning unit mounting portion 40B to a cleaning position above the first right frame 404A. The pair of rotating levers 454 are rotated around the rotating shaft 451 so as to reach . Therefore, even though the upper part of the cleaning unit 70 arranged at the attachment/detachment position is covered by the first right frame 404A, the cleaning unit 70 moves out of the cleaning unit mounting portion 40B to the right side and is removed from the first right frame 404A. can also reach the upper cleaning position.

In the present embodiment, the first detection sensor 803 detects the amount of rotation of the pulse plate 802 with reference to the attachment/detachment position (storage position) shown in FIG. The position (cleaning position, separation position) of the cleaning unit 70 is detected. Further, when the second detection sensor 804 detects the cleaning housing 70H, it is detected that the cleaning unit 70 has reached the cleaning position. When the pair of guide rollers 705 of the cleaning unit 70 come into contact with the pair of positioning portions 102S, the rotation of the rotating lever 454 is restricted by the unit fulcrum pin 70P. After that, the unit driving section 80 is controlled to rotate the rotating shaft 451 slightly. At this time, since the coil spring 455 is interposed between the rotating lever 454 and the lever support portion 453, the coil spring 455 is compressed and deformed between the rotating lever 454 and the lever support portion 453, thereby causing the rotation. In a state where the rotation of the moving lever 454 about the rotating shaft 451 is stopped, the application of the rotating force of the lever support portion 453 by the unit driving portion 80 to the rotating lever 454 is blocked (restricted). In this way, even after the first detection sensor 803 and the second detection sensor 804 have detected that the cleaning unit 70 has reached the cleaning position, the rotary shaft 451 can be rotated slightly. The difference (error) in the mounting position of the moving lever 454 can be absorbed, and the cleaning unit 70 can be reliably arranged at the cleaning position. As a result, the pressing force of the pressing roller 72 against the lower registration roller 32 can be stably maintained.

FIG. 32 is graphs (A), (B) and (C) showing the nip load distribution of the pair of registration rollers. FIG. 33 is a cross-sectional perspective view of another registration roller pair and cleaning unit 70Z compared with this embodiment. FIG. 32A shows the axial distribution of the nip load (pressure) applied between the upper resist roller 31 and the lower resist roller 32 when the pressure roller 72 is not in contact with the lower resist roller 32. FIG. there is On the other hand, FIG. 32(B) shows the distribution of the same nip load in the configuration shown in FIG. In the cleaning unit 70Z of FIG. 33, contact rollers 72H are fixed to both ends of the pressure roller shaft 72S of the pressure roller 72 in the axial direction. The contact roller 72</b>H contacts the shaft 32</b>S of the lower registration roller 32 to regulate the distance between the axes of the lower registration roller 32 and the pressure roller 72 and regulate the pressing force of the pressure roller 72 against the lower registration roller 32 . In this way, when the pressing roller 72 is positioned with respect to the lower registration roller 32 by bringing parts thereof into contact with each other, the upper registration roller 31 and the lower registration roller 32 are arranged as shown in FIG. Both ends of the nip load between are likely to increase greatly. This phenomenon is caused by the fact that both ends of the lower resist roller 32 are strongly pressed against both ends of the upper resist roller 31 by the pressing force of the pressing roller 72 against the lower resist roller 32 . In this case, since the nip load at both ends of the registration roller pair in the axial direction is excessive compared to the central portion, a difference occurs in the conveying speed of the sheet S in the axial direction, and the sheet S tends to wrinkle.

On the other hand, in the present embodiment, as shown in FIG. 31, the positioning portion 102S provided at a position different from the lower registration roller 32 receives the unit fulcrum pin 70P of the cleaning unit 70, so that the pressing roller 72 is positioned under the registration. The position with respect to the roller 32 is regulated. As a result, as shown in FIG. 32C, compared to the cleaning unit 70Z, an increase in the nip load of the registration roller pair is suppressed, and the sheet can be conveyed stably by the registration roller pair.

In this embodiment, when the image forming apparatus 1 performs double-sided printing, the cleaning unit 70 cleans the lower registration roller 32 . As described above, the sheet S on which an image is formed on the front side in the double-sided printing operation passes through the sheet reversing section 15 and the third conveying path 13, and is conveyed into the registration roller section 30 again with the front side and the back side reversed. . At this time, if the ink of the image formed on the surface adheres to the surface of the PFA tube of the lower resist roller 32, the ink adheres to the leading edge of the next sheet S from the lower resist roller 32, causing sheet contamination. Further, when the ink adhering to the lower resist roller 32 is transferred to the upper resist roller 31, the ink adheres to the surface of the next sheet S, thereby causing an image defect in the printed image. Therefore, in the present embodiment, the web W of the cleaning unit 70 cleans ink adhering to the lower resist roller 32 when the back surface of the sheet S passes through the lower resist roller 32 during double-sided printing. For this reason, the control section 90 arranges the cleaning unit 70 at the cleaning position for double-sided printing, and arranges the cleaning unit 70 at the separated position for single-sided printing. As a result, it is possible to clean the lower registration roller 32 over a long period of time even with the limited length of the web roll WR, and it is possible to make the web roll WR compact and to reduce the size of the cleaning device 7. becomes.

Further, when an image is formed under conditions where the surface of the lower registration roller 32 is less likely to become dirty, such as during single-sided printing, the cleaning unit 70 is arranged at the separated position so that the cleaning section 70A can be applied to the lower registration roller 32. It is possible to reduce the load on the lower registration roller 32 due to the contact and to suppress unnecessary feeding out of the web W.

On the other hand, when it is detected from the detection result of the third detection sensor 813 of the web delivery mechanism 81 that the web roll WR has been completely delivered from the web driven roller 71, the control section 90 sends a replacement message for the cleaning unit 70 to the image forming apparatus. 1 is displayed on the display unit (not shown). When an operator instructs execution of replacement work of the cleaning unit 70 using an operation unit (not shown) of the image forming apparatus 1, the control unit 90 controls the moving mechanism 75 to move the cleaning unit 70 to the attachment/detachment position. After that, the operator pulls out the transport unit frame 40H forward from the main body frame 100 of the apparatus main body 10, removes the cleaning unit 70 from the cleaning unit mounting portion 40B of the transport unit frame 40H, and attaches a new cleaning unit 70 to the transport unit frame 40H. cleaning unit mounting portion 40B. In the present embodiment, as described above, the state of the web roll WR held by the web driven roller 71 is monitored through the opening formed between the side wall 703A and the bottom wall 703B in FIG. It is visible from the outside of 70 . Therefore, when the operator pulls out the transport unit frame 40H from the main body frame 100 of the apparatus main body 10, the remaining amount of the web roll WR of the cleaning unit 70 stored in the transport unit frame 40H is removed from the pulled out transport unit frame 40H. It can be seen from the right side. In other words, in the present embodiment, the cleaning unit mounting portion 40B is positioned on the right side of the transport unit frame 40H so that the right side of the cleaning unit 70 where the web roll WR is exposed outside the cleaning housing 70H is visible. are placed in

In the present embodiment, when the cleaning unit 70 is detached from the apparatus main body 10 integrally with the transport unit frame 40H, a part of the drive transmission system between the rotary drive section 75K and the pair of rotary levers 454 (device The engagement between the main body 10G and the unit drive output gear 805) is cut off. As a result, the pair of rotating levers 454 are rotatable around the rotating shaft 451 . Therefore, when the operator removes the old cleaning unit 70 from the cleaning unit mounting portion 40B, the pair of rotating levers 454 can rotate so as to send the cleaning unit 70 out of the cleaning unit mounting portion 40B. In other words, the pair of rotating levers 454 rotates around the rotating shaft 451 so as to assist the pair of unit fulcrum pins 70P of the cleaning unit 70 to be separated from the pair of pin receiving portions 454P. As a result, the operator can easily remove the pair of unit fulcrum pins 70P of the cleaning unit 70 from the pair of pin receiving portions 454P. As a result, the cleaning unit 70 can be easily removed from the transport unit frame 40</b>H of the belt transport unit 40 .

The cleaning device 7 and the image forming apparatus 1 including the same according to one embodiment of the present invention have been described above. According to such a configuration, it is possible to stably form an image in the image forming apparatus 1 while stably cleaning the surface of the lower registration roller 32 . It should be noted that the present invention is not limited to the above-described embodiments, and it is possible to adopt the following modified embodiments.

(1) In the above embodiment, the cleaning portion 70A of the cleaning unit 70 has the web W, but the cleaning portion 70A for cleaning the lower resist roller 32 is not limited to the web W. Other cleaning members such as sponge rollers and brush rollers that contact the lower roller 32 may also be included.

(2) In the above embodiment, the lower resist roller 32 is used as the transport roller to be cleaned by the cleaning unit 70, but the transport roller may be another roller that transports the sheet S. FIG.

(3) In the above-described embodiment, the image forming unit 50 uses an ink jet method. .

1 Image forming apparatus 10 Apparatus main body 100 Main body frame 100G Guide section 101 Guide frame 101R First guide surface 102 Registration frame 102R Second guide surface 102S Positioning section 20 Paper feed section 30 Registration roller section 30H Registration housing 31 Upper registration roller (upper registration roller)
32 Lower registration roller (transport roller, lower registration roller)
40 belt transport unit (transport unit)
40A transport unit mounting portion 40B cleaning unit mounting portion (unit housing portion)
40G rotation input gear 40H transport unit frame 401 front frame (unit frame)
402 rear frame (unit frame)
404A first right frame (upper connection frame)
404B second right frame (lower connection frame)
404C magnet (magnetic member)
41 conveyor belt (conveyor)
45 cleaning unit rotating portion 451 rotating shaft 452 rotating gear 453 lever supporting portion (fixed member)
454 Rotating lever (supporting member)
454P pin receiving part (pivot part)
455 Coil spring 50 Image forming unit 60 Curling unit 7 Cleaning device 70 Cleaning unit 70A Cleaning unit 70H Cleaning housing 70P Unit fulcrum pin (housing shaft)
701 front wall 701 (wall portion)
702 rear wall 702 (wall portion)
703B bottom wall 704 sheet member 705 guide roller (guide roller)
71 web driven roller (delivery roller)
711 unit input gear 72 pressure roller 73 web drive roller (winding roller)
75 moving mechanism 75K rotating drive unit 80 unit drive unit 801 drive motor output shaft 802 pulse plate 803 first detection sensor 804 second detection sensor 805 unit drive output gear 81 web delivery mechanism (web drive mechanism)
811 solenoid 812 rotating arm 813 third detection sensor 90 control unit W web WR web roll

Claims (13)

A cleaning device capable of cleaning the surface of a conveying roller that is rotatably supported by an apparatus body of an image forming apparatus and conveys a sheet,
a cleaning unit having a contact surface extending along the axial direction of the transport roller, the contact surface contacting the surface of the transport roller from below to clean the surface; and a cleaning housing supporting the cleaning unit. and a cleaning unit having
A moving mechanism capable of moving the cleaning unit between a cleaning position and an attachment/detachment position below the cleaning position, wherein the cleaning unit is allowed to come into contact with the conveying roller at the cleaning position. a moving mechanism for allowing the cleaning unit to be attached to and detached from the apparatus main body, and the cleaning unit to be spaced downward from the conveying roller at the attachment/detachment position;
with
The cleaning housing is
a pair of wall portions arranged to face each other in the axial direction and supporting the cleaning portion;
a pair of housing shaft portions projecting in the axial direction from outer side surfaces of the pair of wall portions;
has
The moving mechanism is
a unit accommodating portion that accommodates the cleaning unit arranged at the attachment/detachment position;
A pair of supporting members arranged in the unit accommodating portion and capable of supporting the cleaning housing so as to sandwich the cleaning housing from both sides in the axial direction, wherein the pair of supporting members support the housing shaft portion. a pair of support members each having a pivot for receiving and rotatably supporting the housing shaft;
The cleaning unit is arranged above the shaft supports so that the cleaning unit can move between the cleaning position and the attachment/detachment position while the pair of housing shafts are supported by the pair of shaft supports. A rotation drive unit for rotating the pair of support members around a first central axis parallel to the axial direction, wherein the cleaning unit maintains a posture in which the cleaning unit faces upward in the rotation drive unit. a rotation drive unit that rotates the pair of support members while allowing the pair of housing shaft portions to rotate relative to the pair of shaft support portions;
a positioning part that contacts the cleaning unit at the cleaning position and positions the cleaning unit so that the cleaning part can clean the transport roller;
has
The rotation drive unit is
a shaft extending along the axial direction and forming the first central axis;
a drive unit that generates a rotational driving force that rotates the shaft;
a pair of fixing members respectively fixed to the shaft so as to be able to hold the pair of support members;
A pair of spring members arranged so as to be interposed between the pair of support members and the pair of fixing members, wherein the pair of spring members are arranged so that the cleaning unit reaches the cleaning position. When the rotation of the pair of support members about the first central axis is restricted by abutting on the support member, the rotation force of the fixed member by the drive unit is prevented from being applied to the support member. a pair of spring members elastically deformed between the fixed member and the support member;
a cleaning device. The cleaning housing further includes a pair of guide rollers each supported by the pair of walls above the housing shaft and including an outer peripheral surface rotatable about a second central axis parallel to the axial direction. death,
The moving mechanisms are spaced apart from each other in the axial direction and extend vertically on one end side in the horizontal width direction perpendicular to the axial direction from the cleaning unit arranged at the attachment/detachment position. a pair of guide portions disposed in the cleaning position, allowing the pair of guide rollers to come into contact with the rotation of the pair of support members about the first central axis, thereby moving the cleaning unit to the cleaning position; 2. The cleaning device according to claim 1, further comprising a pair of guide portions for guiding between said attachment/detachment position. In a state where the cleaning unit is arranged at the attachment/detachment position, the pair of support members are arranged so as to extend downward from the first central axis, and the shaft support portion is arranged at the one end of the support members in the width direction. has a shape in which the housing shaft portion is received along a direction orthogonal to the axial direction. ,
The rotation driving portion rotates the pair of support members to the first center so that the housing shaft portion moves to the one end side and upward in the width direction from the state in which the cleaning unit is arranged at the attachment/detachment position. 3. The cleaning device according to claim 2, wherein the cleaning unit is moved to the cleaning position by rotating about an axis. When the cleaning unit arranged at the attachment/detachment position is viewed from a direction parallel to the axial direction, the center of the housing shaft portion supported by the shaft support portion is located below the first central axis and in the width direction. The cleaning unit is arranged on one end side, and the center of gravity of the cleaning unit is arranged on the one end side in the width direction with respect to the housing shaft portion,
When the rotation driving section rotates the pair of support members about the first center shaft from the state in which the cleaning unit is arranged at the attachment/detachment position, the weight of the cleaning unit causes the cleaning unit to move toward the housing shaft. 4 . The cleaning device according to claim 3 , wherein the pair of guide rollers are brought into contact with the pair of guide portions by tilting toward the one end side in the width direction about the portion. the cleaning housing is made of a magnetic material and has a connecting wall connecting the pair of wall portions along the axial direction;
5. The unit storage portion according to claim 4, wherein the unit accommodating portion has at least one magnetic member arranged to face the connection wall of the cleaning housing arranged at the attachment/detachment position and generating a magnetic field for holding the cleaning unit. cleaning equipment. wherein the connecting wall of the cleaning housing is a bottom wall defining a bottom of the cleaning housing,
The at least one magnetic member is arranged to face the bottom wall of the cleaning unit arranged at the attachment/detachment position,
When the cleaning unit arranged at the attachment/detachment position is viewed from a direction parallel to the axial direction, the center of the magnetic member in the width direction is wider than the center of the housing shaft portion supported by the shaft support portion. 6. A cleaning device according to claim 5, arranged at said one end side of the direction. The cleaning unit
a strip-shaped web having a contact surface capable of coming into contact with the transport roller;
a pressing roller that presses the web against the transport roller;
a delivery roller for delivering the web and a take-up roller for taking up the web such that a portion of the web in contact with the transport roller changes;
has
7. The web drive mechanism according to any one of claims 1 to 6, further comprising a web drive mechanism connected to the cleaning unit arranged at the cleaning position and rotationally driving at least the take-up roller out of the delivery roller and the take-up roller. The cleaning device according to . The moving mechanism can move the cleaning unit not only to the cleaning position and the attachment/detachment position, but also to a separated position between the cleaning position and the attachment/detachment position. 8. The cleaning device according to claim 7, wherein the cleaning unit is spaced downward from the transport roller and the cleaning unit and the web drive mechanism are disconnected. a device body;
a conveying roller that conveys the sheet;
an image forming unit that forms an image on the sheet;
9. The cleaning device according to any one of claims 1 to 8, capable of cleaning the transport roller;
An image forming apparatus comprising: a conveying unit that conveys the sheet at a position different from the conveying roller, and is attachable to the apparatus main body along a first direction parallel to the axial direction and in a second direction opposite to the first direction; further comprising a transport unit detachable from the apparatus main body along
The unit accommodating section is arranged in the transport unit, and when the cleaning unit is arranged in the attachment/detachment position, the cleaning unit can be attached to and detached from the apparatus body integrally with the transport unit. 10. The image forming apparatus according to claim 9, wherein: When the cleaning unit is detached from the apparatus body integrally with the transport unit, a part of the drive transmission system between the rotary drive section and the pair of support members is cut off, so that the cleaning unit is removed. 11. The image according to claim 10, wherein the pair of support members are rotatable about the first central axis so as to assist the pair of housing shafts of the housing shafts to be disengaged from the pair of shaft supports. forming device. The transport unit is
a pair of unit frames arranged facing each other in the axial direction and supporting the conveying unit;
a lower connection frame that connects the pair of unit frames to each other along the axial direction and supports the cleaning unit arranged at the attachment/detachment position from below;
The lower connection frame connects the pair of unit frames to each other along the axial direction above the lower connection frame and covers at least a portion of the cleaning unit arranged at the attachment/detachment position. an upper connection frame defining the unit housing between
has
The rotary drive section moves the pair of support members so that the cleaning unit reaches the cleaning position above the upper connection frame while being removed from the unit housing section in a horizontal direction perpendicular to the axial direction. 12. The image forming apparatus according to claim 10, wherein the image forming apparatus is rotated around the first central axis. further comprising an upper registration roller that conveys the sheet toward the image forming unit in accordance with image formation timing in the image forming unit;
The conveying roller is disposed below the upper registration roller, forms a nip portion with the upper registration roller through which the sheet passes, and conveys the sheet toward the image forming section in accordance with the image forming timing. Configure the lower registration roller to
13. The image forming apparatus according to claim 9, wherein said cleaning device cleans the surface of said lower registration roller.

Images