JP2010026149A - Image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To easily fit a waste toner carrying-out pipe in an opening of a recovery pipe. <P>SOLUTION: The image forming apparatus includes an intermediate transfer unit 20 comprising an intermediate transfer belt 21 to which a toner image is transferred from a photoreceptor drum 131 and a belt cleaning device 30 which cleans a surface of the intermediate transfer belt 21, and a toner recycling device 80 which recovers a waste toner that the belt cleaning device 30 removes from the intermediate transfer belt 21. The belt cleaning device 30 has the waste toner carrying-out pipe 60 for carrying the waste toner removed from the intermediate transfer belt 21 to the toner recycling device 80. The toner recycling device 80 has a head pipe 83 having a connection opening 831 into which the waste toner carrying-out pipe 60 is inserted by pressing the intermediate transfer unit 20 into a printer body 11. An annular inclined edge surface 625 which is tapered and inclined over the entire periphery is formed at a peripheral edge of a circular cover body 62 on the tip side of the waste toner carrying-output pipe 60. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an image forming apparatus configured to transfer a toner image onto a sheet via an intermediate transfer belt on which a toner image transferred from a photosensitive drum is formed. The present invention relates to an image forming apparatus in which a cleaning device that performs a cleaning process on the surface thereof is unitized.

  Conventionally, a cleaning device applied to an image forming apparatus as described in Patent Document 1 is known. This cleaning device removes residual toner (hereinafter referred to as waste toner) remaining on the surface of the transfer belt and cleans it, and a brush roller that scrapes the waste toner on the surface of the transfer belt while rotating, A bias roller to which a voltage for electrically transferring the waste toner scraped by the brush roller is applied, a blade for scraping the waste toner on the circumferential surface of the bias roller, and a waste tank for scraping the waste toner scraped by the blade A conveying screw that conveys toward the inner side is formed in a predetermined housing.

  Such a cleaning device is attached to a support plate that supports a transfer belt in a belt unit (intermediate transfer unit) that is detachable from the main body of the image forming apparatus. Therefore, for example, when the belt unit is inserted into and removed from the apparatus main body for maintenance work, the cleaning apparatus is also inserted and removed with the belt unit.

  Therefore, when the cleaning device is provided on the apparatus main body side, it is necessary to ensure the relative positional relationship between the two precisely, and it is necessary to provide a member for that purpose. In addition to going backwards, there was a problem that the workability of the maintenance work was inferior, but these problems were solved by integrating the cleaning device with the belt unit, improving the installation accuracy of the device, This is effective in improving maintainability and ease of assembly, and further promoting the downsizing of the apparatus.

  In an image forming apparatus of the type in which such a cleaning device is integrally attached to the belt unit, the belt unit is pulled out from the apparatus main body and a predetermined maintenance operation is completed, and then the belt unit is pushed into the apparatus main body. Then, the tip of the waste toner discharge pipe for discharging the waste toner with the conveying screw in the cleaning device is inserted into a recovery pipe provided in a predetermined frame on the apparatus main body side. The tank is in communication.

By rotating the conveying screw about the axis in this state, the collected toner in the cleaning device can be collected into the collecting tank through the waste toner discharge pipe and the collecting pipe on the apparatus main body side.
JP 2000-19861 A

  By the way, the apparatus main body of the image forming apparatus has a pair of guide rails laid at the same height level, and the belt unit is inserted into and removed from the apparatus main body while being guided by these guide rails. Since the belt unit guided by the guide rail is not necessarily moved while ensuring a precise positional relationship with the recovery pipe, the waste toner of the cleaning device laid on the belt unit once pulled out from the main body of the device The tip of the carry-out pipe does not necessarily correspond exactly to the opening of the recovery pipe.

  In particular, the tip of the waste toner discharge pipe is often lowered from the position of the connection opening of the recovery pipe due to its weight. Therefore, when the waste toner pipe is directed to the recovery pipe by the pushing operation of the belt unit, the waste toner pipe interferes with the peripheral edge of the recovery pipe, and cannot be connected to the recovery pipe.

  In order to eliminate such inconvenience, when the belt unit is pushed in, the belt unit is pushed into the apparatus main body while properly correcting the posture of the belt unit so that the tip of the waste toner discharge pipe faces the opening of the collection pipe. There is a problem that it has to go, it is very complicated and troublesome, and workability is inferior.

  The present invention has been made in view of the situation as described above, and when the intermediate transfer unit once pulled out is pushed into the apparatus main body, the waste toner carrying pipe is not particularly required to pay attention to the posture of the intermediate transfer unit. It is an object of the present invention to provide an image forming apparatus that can be fitted into an opening of a recovery pipe, thereby improving the workability of connecting the waste toner discharge pipe to the recovery pipe.

  According to a first aspect of the present invention (image forming apparatus), an intermediate transfer belt on which a toner image from an image carrier is transferred to a surface and a cleaning device for performing a cleaning process on the surface of the intermediate transfer belt are unitized. And an intermediate transfer unit that can be inserted into and removed from the apparatus main body, and a toner collecting device that collects waste toner removed from the intermediate transfer belt by the cleaning device, and the cleaning device is removed from the intermediate transfer belt. A waste toner carry-out pipe that conveys the waste toner toward the toner collection device, and the toner collection device has a waste waste pipe into which the waste toner carry-out pipe is inserted when the intermediate transfer unit is pushed into the apparatus main body. A waste toner collecting pipe having a toner receiving port; It is characterized in that the inclined annular inclined edge surface is formed on Ri.

  According to such a configuration, the waste toner carrying pipe of the cleaning device is moved to the toner by pushing the intermediate transfer unit, which is pulled out from the device main body and made into a unit of the intermediate transfer belt and the cleaning device, into the device main body. The waste toner that is inserted into a waste toner receiving port provided in the waste toner recovery pipe of the recovery device and removed by the cleaning device cleaning the intermediate transfer belt by the cleaning device is disposed in the waste toner discharge pipe and the waste toner recovery pipe. And is collected in the toner collecting device.

  In addition, since an annular inclined edge surface that is tapered and tapered is formed at the peripheral edge portion on the front end side of the waste toner discharge pipe, there is a misalignment between the waste toner discharge pipe and the waste toner receiving port. However, in the case of misalignment within the range of the annular inclined edge surface, any portion of the annular inclined edge surface comes into contact with the edge of the waste toner receiving port with the center being out of alignment. Therefore, after that, by pushing in the waste toner carrying pipe, the annular inclined edge surface is fitted into the waste toner receiving port while receiving a force in the direction of correcting the misalignment from the edge of the waste toner receiving port. Therefore, when the intermediate transfer unit is pushed into the apparatus main body, the waste toner carry-out pipe is fitted into the waste toner receiving port.

  In this manner, by forming an annular inclined edge surface that is tapered and tapered at the peripheral edge on the front end side of the waste toner discharge pipe, the waste toner can be obtained simply by pushing the intermediate transfer unit once drawn into the apparatus main body. It becomes possible to reliably insert the carry-out pipe into the waste toner receiving port. Therefore, the conventional troublesome operation of adjusting the strength and direction of the pushing force according to the situation while comparing the front end side of the waste toner carrying pipe and the waste toner receiving port as compared with the conventional one becomes unnecessary. The operability of the insertion / removal operation with respect to the apparatus main body of the intermediate transfer unit obtained by unitizing the cleaning apparatus is greatly improved.

  According to a second aspect of the present invention, in the first aspect of the present invention, at least a pair of guide projecting pieces extending outward in the pipe center direction protrude from the further tip side of the annular inclined edge surface. On the outer edge surface of each guide protrusion, an inclination is set so that the distance from the pipe core gradually decreases toward the tip.

  According to this configuration, the edge portion of the waste toner receiving port on the inclined edge surface of the waste toner discharge pipe is provided by projecting at least a pair of guide protrusions extending outward in the pipe center direction from the annular inclined edge surface. Therefore, even if a considerable misalignment exists between the waste toner carrying pipe and the waste toner receiving port, it is possible to sufficiently cope with the elimination of the misalignment.

  According to a third aspect of the present invention, in the second aspect of the present invention, the guide projecting pieces are provided at positions above and below the annular inclined edge surface, respectively.

  According to this configuration, the cleaning device attached to the intermediate transfer unit has a tendency that the side on which the waste toner discharge pipe protrudes tends to be inclined downward due to its weight, so that the guide protrusion is positioned above and below the annular inclined edge surface. It is possible to cope with the vertical inclination of the waste toner carrying pipe.

  According to the image forming apparatus of the present invention, when the intermediate transfer unit once pulled out is pushed into the apparatus main body, the situation is compared with the front end side of the waste toner carry-out pipe and the waste toner receiving port as conventionally performed. This eliminates the need for troublesome operations such as adjusting the strength and direction of the push-in force depending on the machine, so it is only necessary to push the drawn-out intermediate transfer unit into the main body, and the intermediate transfer belt and the cleaning device The operability of pushing the united intermediate transfer unit into the apparatus main body can be greatly improved.

  FIG. 1 is a cross-sectional explanatory view for explaining the internal structure of an embodiment of an image forming apparatus to which a cleaning device according to the present invention is applied. In the present embodiment, the printer 10 is employed as the image forming apparatus. As shown in FIG. 1, the printer 10 includes a paper feeding unit 12 that stores a bundle of paper P, an image forming unit 13 that transfers a toner image onto the paper P conveyed from the paper feeding unit 12, and the image The printer main body 11 includes a fixing unit 14 that performs a fixing process on the toner image transferred to the paper P by the forming unit 13 and a paper discharge unit 15 that discharges the paper P subjected to the fixing process by the fixing unit 14. It is configured by being attached.

  The paper feeding unit 12 is provided at a lower right side in FIG. 1 of the paper cassette 121 that can store a plurality of papers P that are removably attached to the lower part of the printer main body 11. And a pickup roller 122. The sheets P stored in the sheet cassette 121 are picked up one by one by driving the pickup roller 122 and sent out toward the image forming unit 13.

  The image forming unit 13 forms a toner image on the paper P fed from the paper feeding unit 12. In the present embodiment, a magenta unit 13M that uses magenta toner and a cyan unit 13C that uses cyan toner are sequentially arranged from the upstream side (left side of the paper surface in FIG. 1) to the downstream side. And a yellow unit 13Y using yellow toner and a black unit 13K using black toner.

  Each of the units 13M, 13C, 13Y, and 13K has an electrostatic latent image on the peripheral surface and a front-rear direction in which a toner image is formed along the electrostatic latent image (a direction perpendicular to the paper surface of FIG. 1). A photosensitive drum (image carrier) 131 that can rotate around the extended axis, and a charging wire that forms a uniform charge on the peripheral surface of the photosensitive drum 131 by performing a charging process on the peripheral surface. A charging device 132, and an exposure device 133 that forms an electrostatic latent image by irradiating a laser beam based on image information onto the peripheral surface of the photosensitive drum 131 to which a uniform charge is applied by the charging device 132; A developing device 134 that forms a toner image on the peripheral surface of the photosensitive drum 131 on which the electrostatic latent image is formed by supplying toner, and each developing device that supplies toner to the developing device 134 To 134 A toner container 135 which is detachably mounted to, and a drum cleaning device 136 for cleaning by removing the waste toner on the peripheral surface of the photosensitive drum 131.

  On the other hand, an intermediate transfer unit 20 for forming a color image by applying toner images formed on the peripheral surface of each photosensitive drum 131 is provided below the image forming unit 13. The intermediate transfer unit 20 is attached to the printer main body 11 so as to be detachable from the front and rear direction (a direction orthogonal to the paper surface of FIG. 1) and is detachably mounted. 201.

  The intermediate frame 201 is provided with an intermediate transfer belt 21 having a surface disposed so as to face the photosensitive drum 131 of each unit 13M, 13C, 13Y, and 13K. A belt cleaning device 30 that removes waste toner remaining on the surface of the transfer belt 21 and performs a cleaning process on the discussion surface is provided.

  A primary transfer roller 22 disposed opposite to the photosensitive drum 131 with the intermediate transfer belt 21 interposed therebetween is provided at a position facing the photosensitive drum 131 on the intermediate transfer belt 21. The toner image on the photosensitive drum 131 is electrically peeled off by the bias applied to the primary transfer roller 22 and transferred to the surface of the intermediate transfer belt 21.

  Further, a secondary transfer roller 137 that electrically peels off the color toner image on the intermediate transfer belt 21 and transfers it to the paper P fed from the paper feeding unit 12 is provided below the intermediate transfer belt 21 in FIG. Is provided.

  The photosensitive drum 131 is for forming an electrostatic latent image and a toner image along the electrostatic latent image on the peripheral surface, and is an extremely smooth amorphous silicon that is tough and has excellent wear resistance on the peripheral surface. The layers are stacked, making them suitable for forming these images. Each of the photosensitive drums 131 is supplied with toner from the corresponding developing device 134 while rotating counterclockwise in FIG.

  The charger 132 is applied with a high voltage from a power supply (not shown) to the charging wire, and a uniform charge is formed on the peripheral surface of the photosensitive drum 131 by corona discharge. Instead of the charger 132, a charging roller to which a high voltage is applied may be brought into contact with the peripheral surface of the photosensitive drum 131, thereby forming a charge on the peripheral surface of the photosensitive drum 131. Good.

  The exposure device 133 irradiates the peripheral surface of the photosensitive drum 131 uniformly charged by the charger 132 with laser light based on image data input from a computer (not shown). An electrostatic latent image is formed on the peripheral surface of the photosensitive drum 131 by the light irradiation. By supplying toner from the developing device 134 to the electrostatic latent image, a toner image is formed on the peripheral surface of the photoconductive drum 131, and this toner image is transferred to the intermediate transfer belt 21 that circulates.

  The developing device 134 is provided with an agitating and conveying member therein, and is provided with a developing roller whose peripheral surface is opposed to the peripheral surface of the photosensitive drum 131 at the lowermost position. It is supplied to the peripheral surface of the body drum 131.

  The fixing unit 14 performs a fixing process on the transfer image transferred to the paper P by the image forming unit 13. The fixing roller 141 is heated by an energizing heating element such as a halogen lamp, and the fixing roller 141 at the lower part. And a pressure roller 142 whose peripheral surface is pressed against and in contact with the peripheral surface of the fixing roller 141.

  The sheet P that has been subjected to the transfer process by the intermediate transfer belt 21 in the image forming unit 13 is guided to the circumference of the intermediate transfer belt 21 while being sandwiched between the intermediate transfer belt 21 and the secondary transfer roller 137, and is fixed to the fixing unit. 14, the toner image is fixed on the paper P by heating when passing between the fixing roller 141 and the pressure roller 142.

  The sheet P after the fixing process is moved up the discharge conveyance path 101 by driving the discharge roller pair 143, and is discharged to the discharge tray 151 provided on the top of the printer main body 11 through the discharge outlet 152.

  FIG. 2 is an explanatory diagram showing an extracted intermediate transfer unit 20 including the intermediate transfer belt 21 and the like in FIG. As shown in FIG. 2, the intermediate transfer unit 20 has a primary transfer roller 22, a driving roller 23, a driven roller 24, a pressing roller 25, a bending roller 26, an upper tension roller 27, and a lower tension roller 28 mounted on an intermediate frame frame 201. In this state, the intermediate frame 201 is formed around these rollers.

  The intermediate frame frame 201 has an elongated shape in the left-right direction when viewed from the direction orthogonal to the paper surface of FIG. 2, and an inverted triangular plate extends downward from the lower edge at a substantially right half position. It has the shape that was set. In the plan view, it has a long rectangular shape in the left-right direction.

  Four primary transfer rollers 22 are arranged in parallel at equal pitches in the left-right direction along the upper edge of the intermediate frame 201 and corresponding to the photosensitive drums 131 of the units 13M, 13C, 13Y, and 13K. ing.

  The drive roller 23 is provided at the left end of the intermediate frame 201. The driving roller 23 is driven by a belt driving motor 230. The belt driving motor 230 is provided concentrically with the driving roller 23 on the rear surface side of the driving roller 23 (the back side of the paper surface of FIG. 2). The driving roller 23 is concentrically connected to the driving shaft 231 of the belt driving motor 230 so as to be integrally rotatable. Accordingly, the drive roller 23 rotates integrally around the drive shaft 231 by driving the belt driving motor 230.

  The driven roller 24 is provided at the right end of the intermediate frame frame 201. Then, in a state where the intermediate transfer belt 21 is wound around the driving roller 23 and the driven roller 24, a plurality of primary transfer rollers 22 and a plurality of upper tensions are provided on the lower surface side along the upper belt of the intermediate transfer belt 21. A roller 27 is provided.

  The pressing roller 25 is for pressing the intermediate transfer belt 21 toward the secondary transfer roller 137, and the intermediate transfer belt 21 is placed at the lowest position of the inverted triangular portion of the right half of the intermediate frame frame 201. Via the secondary transfer roller 137. When the pressing roller 25 presses the intermediate transfer belt 21 toward the secondary transfer roller 137, the toner image on the intermediate transfer belt 21 can be transferred to the paper P conveyed to the position of the pressing roller 25. .

  The bending roller 26 is disposed in the intermediate frame frame 201 at a position directly below the primary transfer roller 22 of the cyan unit 13C on the right side of the drive roller 23, and the intermediate transfer belt 21 is bent at this position. .

  The secondary transfer roller 137 is pressed by the pressing roller 25 via the intermediate transfer belt 21 at a position directly below the pressing roller 25. A bias voltage for electrostatically peeling off the toner image on the intermediate transfer belt 21 is applied to the secondary transfer roller 137 from a power source (not shown). Accordingly, the toner image on the intermediate transfer belt 21 is transferred to the paper P passing between the intermediate transfer belt 21 and the secondary transfer roller 137.

  Further, the upper tension roller 27 is provided at the left position of each primary transfer roller 22, and between the bending roller 26 and the pressing roller 25 and between the driven roller 24 and the pressing roller 25. Each of the lower tension rollers 28 is provided. These upper and lower tension rollers 27 and 28 are for maintaining a tension state so that the intermediate transfer belt 21 does not slack.

  In this embodiment, the belt cleaning device 30 is mounted at a position below the left lower tension roller 28 via the intermediate transfer belt 21 in the intermediate frame 201 of the intermediate transfer unit 20 configured as described above. .

  3 and 4 are perspective views schematically illustrating the relative positional relationship between the intermediate frame 201 and the belt cleaning device 30, and FIG. 3 is a perspective view seen from the front side. FIG. 3 is a perspective view seen from the back side. In these drawings, (A) shows the state immediately before the waste toner carrying pipe 60 is connected to the waste toner collecting pipe 82, and (B) shows the waste toner carrying pipe 60 connected to the waste toner collecting pipe 82. Each state is shown. 3 and 4, the X direction is referred to as the left-right direction, and the Y direction is referred to as the front-rear direction. In particular, -X is referred to as the left, + X is referred to as the right, -Y is referred to as the front, and + Y is referred to as the rear.

  As shown in these drawings, the intermediate frame 201 has a front frame plate 202 having a shape corresponding to the rotation route of the intermediate transfer belt 21 in a front view viewed from the −Y direction, and the front frame plate 202 at the rear. An opposed rear frame plate 203 having substantially the same shape, a left frame plate 204 installed at the left end portion between the front and rear frame plates 202, 203, and a right frame plate 205 installed between the right end portions. It has a rectangular shape that is long in the left-right direction in plan view.

  The primary transfer roller 22, the driving roller 23, the driven roller 24, the pressing roller 25, the bending roller 26, the upper tension roller 27, and the lower tension roller 28 are respectively rotated by a front frame plate 202 and a rotatable shaft around a predetermined axis. It is installed between the rear frame plates 203. The intermediate transfer belt 21 is wound around these rollers 22 to 28.

  On the other hand, the printer main body 11 includes a rear wall 111 provided at the rear, and a left side wall 112 and a right side wall 113 that extend forward from the left and right edges of the rear wall 111. . The intermediate transfer unit 20 is mounted so as to be movable forward and backward between the left and right side walls 112 and 113.

  Specifically, rail members 29 are interposed between the left frame plate 204 and the left side wall 112 and between the right frame plate 205 and the right side wall 113, respectively. The rail member 29 includes a fixed rail 291 that is fixed to the left and right side walls 112 and 113 so as to extend in the front-rear direction, and the fixed rails that are provided on the left and right frame plates 204 and 205, respectively. 291 is provided with a movable rail 292 supported in a sliding contact state.

  Accordingly, the intermediate transfer unit 20 can be repositioned between the storage position and the drawer position by gripping and moving the handle 202a provided at a suitable position on the front surface of the front frame plate 202 back and forth.

  A positioning pin 114 projecting forward is projected from a substantially central portion in the left-right direction of the rear wall 111 and slightly below the upper edge of the intermediate transfer unit 20. A positioning hole 206 is formed in the rear frame plate 203 of the transfer unit 20 at a position corresponding to the positioning pin 114. Then, by pushing the intermediate transfer unit 20 into the printer main body 11, the positioning hole 206 is fitted onto the positioning pin 114, whereby the intermediate transfer unit 20 is positioned within the printer main body 11.

  The belt cleaning device 30 is located immediately to the left of the pressing roller 25 in the intermediate frame frame 201 of the intermediate transfer unit 20 and directly below the left lower tension roller 28 via the intermediate transfer belt 21. It is attached so that it moves along with the movement of the intermediate frame 201.

  FIG. 5 is a perspective view showing an embodiment of the belt cleaning device 30. The direction display by X and Y in FIG. 5 is the same as in FIG. 4 (−X: leftward, + X: rightward, −Y: forward, + Y: backward).

  As shown in FIG. 5, the belt cleaning device 30 includes a brush roller 40 whose peripheral surface is in contact with the surface of the intermediate transfer belt 21 in a casing 31 indicated by a two-dotted line having a box shape, and this brush. A charging roller 45 that electrostatically sucks and removes the waste toner scraped off from the intermediate transfer belt 21 by the roller 40, a blade 43 that scrapes off the waste toner adhering to the peripheral surface of the charging roller 45, and scraping off by the blade 43. A screw member 50 that conveys the waste toner that has been discharged toward a waste toner collection pipe 82, which will be described later, and a waste toner discharge pipe that projects through the rear plate 311 of the casing 31 toward the rear waste toner collection pipe 82 60 and a shutter member 70 that is externally fitted to the waste toner carrying pipe 60.

  The brush roller 40 includes a brush shaft 41 installed at an upper position between the rear plate 311 and the front plate 312 of the casing 31 and brush bristles 42 concentrically planted on the brush shaft 41 in a cylindrical shape. Yes. On the other hand, the front plate 312 is provided with a brush drive motor 39 with a drive shaft directed in the front-rear direction on the front side. The drive shaft of the brush drive motor 39 is concentrically connected to the brush shaft 41 so as to be integrally rotatable, whereby the drive rotation of the brush drive motor 39 is directly transmitted to the brush roller 40.

  The waste toner scraped off from the intermediate transfer belt 21 by the rotation of the brush roller 40 and attached to the peripheral surface of the charging roller 45 is removed by the blade 43 and falls onto the screw member 50 below.

  The screw member 50 includes a screw shaft 51 disposed at a lower position between the rear plate 311 and the front plate 312 in the casing 31 and a spiral fin 52 formed concentrically with the screw shaft 51. The screw member 50 extends to the inside of the waste toner discharge pipe 60. Accordingly, the waste toner accumulated at the bottom of the casing 31 is sent out toward the toner collecting device 80 through the waste toner carry-out pipe 60 as the spiral fin 52 rotates integrally around the screw shaft 51.

  A gear mechanism 38 for transmitting the driving force of the brush driving motor 39 to the screw member 50 is provided on the rear plate 311 side of the casing 31. Accordingly, the drive rotation of the brush drive motor 39 is transmitted to the screw member 50 via the brush shaft 41 and the gear mechanism 38.

  In such a belt cleaning device 30, a front plate 312 of the casing 31 is provided with a predetermined number of cylindrical front locking protrusions 32 protruding forward from the appropriate position, and the casing 31 has a casing. A predetermined number of columnar rear locking protrusions 33 are also provided on the rear plate 311 of 31.

  On the other hand, the front frame plate 202 of the intermediate frame 201 is provided with a locking hole 202b for inserting the front locking protrusion 32 in a sliding state at a position corresponding to the front locking protrusion 32. In addition, the rear frame plate 203 is provided with a long hole 203 a extending in the vertical direction for fitting the rear locking projection piece 33 into a position corresponding to the rear locking projection piece 33. . Then, the belt locking device 30 is mounted on the intermediate frame frame 201 by inserting the front locking protrusion 32 into the locking hole 202b and inserting the rear locking protrusion 33 into the long hole 203a.

  The long hole 203a into which the rear locking projection piece 33 is fitted is formed into a long hole so as to absorb a dimensional error and an assembling error when the waste toner carrying pipe 60 is connected to a waste toner collecting pipe 82 described later. As much play as possible is required, and the waste toner carry-out pipe 60 can be swung up and down to cope with this.

  The waste toner carry-out pipe 60 is connected to a toner collecting device 80 provided on the rear side of the rear wall 111 in the printer body 11 at the front end side when the drawn intermediate transfer unit 20 is pushed into the printer body 11. As a result, the waste toner scraped off from the intermediate transfer belt 21 by the belt cleaning device 30 is recovered by the toner recovery device 80.

  As shown in FIG. 2, the toner collecting device 80 is erected upward from the waste toner storage container 81 disposed on the bottom plate at the back of the printer main body 11 and the top plate of the waste toner storage container 81. The waste toner collecting pipe 82 is provided. As shown in FIG. 7, a horizontal head pipe 83 having a connection opening (waste toner receiving port) 831 for connecting a later-described transport pipe main body 61 is provided on the top of the waste toner collecting pipe 82. Yes.

  6 and 7 are partially enlarged views of FIG. 5 showing one embodiment of the waste toner carrying pipe 60 and the shutter member 70, FIG. 6 is an exploded perspective view, and FIG. 7 is an assembled perspective view. 6 and 7 are the same as those shown in FIG. 3 (-X: leftward, + X: rightward, -Y: forward, + Y: backward). Incidentally, FIG. 6 shows a perspective view of the circular lid 62 viewed from the front (−Y side) in a circle.

  First, as shown in FIG. 6, the waste toner carrying pipe 60 includes a cylindrical carrying pipe main body 61 projecting rearward from the rear plate 311 of the casing 31 and a front end (rear side) of the carrying pipe main body 61. And a circular lid 62 attached to the end.

  The transport pipe main body 61 has a constant inner diameter, but the outer diameter varies depending on the location. The large diameter portion 611 on the base end side (front side), the middle diameter portion 612 in the center portion, and the distal end And a small-diameter portion 613 on the side (rear end side). The front and rear dimensions of the large diameter part 611 and the small diameter part 613 are slight, but the front and rear dimensions of the medium diameter part 612 are set to be considerably long. A waste toner discharge port 614 for discharging toner is provided on the lower surface side behind the middle diameter portion 612. The waste toner that has been transported through the transport pipe main body 61 is discharged from the waste toner discharge port 614 to the waste toner collection pipe 82.

  The small-diameter portion 613 is provided with a pair of anti-rotation grooves 615 formed in a state of being cut from the rear end face at point-symmetric positions. These anti-rotation grooves 615 are used to prevent the circular lid body 62 fitted on the small-diameter portion 613 of the transport pipe main body 61 from rotating.

  The circular lid 62 is for closing the rear end opening of the transport pipe main body 61. The circular lid 62 includes a lid body 621 whose inner diameter is slightly larger than the outer diameter of the small diameter portion 613 of the transport pipe body 61, and a closed disc 622 that closes the rear opening of the lid body 621. ing.

  The outer diameter of the lid body 621 is set slightly smaller than the inner diameter of the connection opening 831 of the head pipe 83 provided at the top of the waste toner collecting pipe 82. Accordingly, the waste toner discharge pipe 60 passes through the connection opening 831 by moving the waste toner discharge pipe 60 rearward in a state where the pipe center of the transport pipe body 61 and the opening center of the connection opening 831 coincide with each other. Is inserted into the head pipe 83.

  On the other hand, the lid body 621 is provided with a pair of anti-rotation protrusions 623 that fit into the anti-rotation grooves 615 at positions corresponding to the anti-rotation grooves 615 of the transport pipe main body 61 on the inner peripheral surface thereof. . Then, when the circular lid 62 is externally fitted to the small-diameter portion 613 of the transport pipe main body 61, the anti-rotation protrusion 623 is fitted into the anti-rotation groove 615, whereby the circular lid 62 is prevented from rotating.

  An inner cylinder 624 through which the screw shaft 51 of the screw member 50 passes is concentrically provided on the inner surface side of the closing disk 622. The screw shaft 51 is dimensioned so as to penetrate the inner cylinder 624 and protrude to the outside in a state where the circular lid 62 is mounted on the transport pipe main body 61. An annular groove 511 is recessed at the tip of the screw shaft 51 protruding outside. Then, with this circular lid 62 attached to the transport pipe body 61, a bifurcated stopper 63 is provided in the annular groove 511 at the tip of the screw shaft 51 protruding outside from the closing disk 622 of the circular lid 62. By fitting the circular lid 62, the circular lid 62 is prevented from being removed from the transport pipe main body 61.

  In addition, the closed disc 622 of the circular lid 62 has an annular inclined edge surface (inclined edge surface) 625 that is set so that the diameter dimension gradually decreases toward the front end (rear side) at the peripheral portion on the rear surface side. Is formed. Such an annular inclined edge surface 625 is formed in a state where the pipe core of the waste toner discharge pipe 60 and the pipe core of the head pipe 83 are not aligned, that is, there is an upset. Even in such a state, the annular inclined edge surface 625 is caused to interfere with the edge of the connection opening 831 of the head pipe 83, and the waste toner discharge pipe 60 is inserted into the head pipe 83 in order to correct the upset by this interference. This is to make it possible.

  Further, in the present embodiment, guide protrusions 626 are provided at the upper and lower positions on the front end surface (rear surface) of the circular lid 62 and projecting rearward. The pair of guide protrusions 626 are inclined so that their opposite edge surfaces are flush with the annular inclined edge surface 625. By providing the guide protrusion 626, the range in which the misalignment of the waste toner carrying pipe 60 with respect to the head pipe 83 can be corrected is expanded.

  Incidentally, the guide protrusions 626 are provided above and below the closing disk 622 because the rear end of the waste toner discharge pipe 60 is lowered due to the weight of the waste toner discharge pipe 60 protruded rearward by the belt cleaning device 30. This is because the possibility of swinging in the vertical direction by tilting toward the top is high, so that it is possible to cope with the upset by the swinging in the vertical direction.

  The shutter member 70 is fitted on the conveyance pipe main body 61 in a sliding contact state, and is moved forward and backward relative to the front-rear direction in response to the insertion / removal operation of the intermediate transfer unit 20 with respect to the printer main body 11. The discharge port 614 is opened and closed. The shutter member 70 includes a shutter cylinder 71 that is externally fitted to the conveyance pipe main body 61 in a sliding contact state, and a flange 72 that is formed at an appropriate position (rear end in the present embodiment) at the rear half of the shutter cylinder 71. And a coil spring 73 fitted on the front side of the flange 72 of the shutter cylinder 71. The coil spring 73 is set to be slightly longer than the middle diameter portion 612 of the transport pipe main body 61. Therefore, after the coil spring 73 is externally fitted to the middle diameter part 612 of the transport pipe body 61, the coil spring 73 is fixed by fitting and fixing the circular lid 62 to the small diameter part 613 at the tip of the transport pipe body 61. The compressed pipe is sandwiched between the large-diameter portion 611 of the transport pipe body 61 and the flange 72 of the shutter member 70.

  Such a shutter member 70 is fitted into the transport pipe main body 61 in a state where the coil spring 73 is fitted on the shutter cylinder 71. As a result, the coil spring 73 is sandwiched between the large diameter portion 611 of the transport pipe body 61 and the flange 72 of the shutter cylinder 71. Then, the coil spring 73 is arranged such that the rear end of the shutter cylinder 71 protrudes slightly rearward from the rear end of the transfer pipe body 61 by fitting the shutter cylinder 71 to the transfer pipe body 61. The length dimension is set.

  The length of the shutter cylinder 71 is set slightly shorter than the middle diameter portion 612 of the transport pipe main body 61 (specifically, shorter than the front and rear dimensions of the waste toner discharge port 614). When the shutter member 70 fitted on 61 is pushed to the foremost position against the urging force of the coil spring 73, the waste toner discharge port 614 is opened, and when the pushing force of the shutter member 70 is weakened, The shutter member 70 is moved rearward by the urging force of the spring 73, whereby the waste toner discharge port 614 is closed.

  Hereinafter, the operation of connecting the belt cleaning device 30 to the toner recovery device 80 will be described with reference to FIG. 8 with reference to other drawings as necessary. FIG. 8 is a cross-sectional view for explaining the connection operation of the belt cleaning device 30 to the toner recovery device 80. FIG. 8A shows the waste toner discharge pipe 60 of the belt cleaning device 30 as a toner recovery device. FIG. 8B shows a state immediately before being connected to the head pipe 83 of 80, and a state in which the waste toner discharge pipe 60 of the belt cleaning device 30 is connected to the head pipe 83 of the toner recovery device 80. Yes. In addition, the direction display by Y in FIG. 8 is the same as that in FIG. 5 (−Y: forward, + Y: backward).

  First, the intermediate transfer unit 20 is pushed into the printer main body 11 as indicated by the white arrow in FIGS. 3 and 4, so that the belt cleaning supported by the intermediate frame frame 201 of the intermediate transfer unit 20 is performed. The device 30 approaches the toner recovery device 80. As a result, the waste toner carry-out pipe 60 passes through the through window 111a provided in the rear wall 111 of the printer main body 11, and as shown in FIG. 8A, the circular lid 62 of the waste toner carry-out pipe 60 becomes the toner collection device. The 80 head pipe 83 faces the connection opening 831.

  At this time, the belt cleaning device 30 is inclined slightly downward toward the rear due to the weight of the waste toner carrying pipe 60 protruding rearward. Accordingly, the pipe core of the waste toner carrying pipe 60 and the pipe core of the head pipe 83 do not coincide with each other, so that a so-called upset is generated.

  When the operation of pushing the intermediate transfer unit 20 into the printer main body 11 is continued in this state, the inclined edge surface of the outer side of the guide protrusion 626 on the lower side of the circular lid 62 is below the connection opening 831 of the head pipe 83. It will contact the edge surface. Therefore, when the pushing operation of the intermediate transfer unit 20 into the printer main body 11 is continued in this contact state, the transport pipe main body 616 receives an upward force from the lower edge surface of the connection opening 831. Therefore, if the pushing operation is continued, the pipe core of the waste toner carrying pipe 60 approaches the pipe core of the head pipe 83, and the misalignment is corrected.

  When the waste toner discharge pipe 60 is fitted into the head pipe 83 by a predetermined dimension, the flange 72 of the shutter member 70 interferes with the peripheral edge portion of the connection opening 831. When the intermediate transfer unit 20 is further pushed into the printer main body 11 in this state, the flange 72 is pressed relatively forward, whereby the waste toner carrying pipe 60 resists the biasing force of the coil spring 73. The waste toner discharge port 614 of the transport pipe main body 61 is opened while being compressed relatively forward.

  Therefore, as shown in FIG. 8B, in the state where the intermediate transfer unit 20 is pushed into the printer main body 11 to the end and positioned at the storage position, the tip of the waste toner discharge pipe 60 is the head pipe. The waste toner discharge port 614 is opened in the head pipe 83 due to the relative movement of the shutter member 70 in the state of being inserted into the head 83.

  In this state, when the screw member 50 is driven and rotated about the screw shaft 51, the waste toner in the casing 31 of the belt cleaning device 30 is conveyed toward the head pipe 83 in the waste toner discharge pipe 60, and waste toner is discharged. The toner is recovered into the waste toner storage container 81 through the outlet 614, the head pipe 83, and the waste toner recovery pipe 82.

  As described above in detail, the printer 10 according to the present invention includes the intermediate transfer belt 21 onto which the toner image is transferred from the photosensitive drum 131, and the belt cleaning device 30 that performs a cleaning process on the surface of the intermediate transfer belt 21. And an intermediate transfer unit 20 that can be inserted into and removed from the printer main body 11 and a toner collecting device 80 that collects waste toner removed by the belt cleaning device 30 from the intermediate transfer belt 21. It will be.

  The belt cleaning device 30 includes a waste toner carry-out pipe 60 that conveys the waste toner removed from the intermediate transfer belt 21 toward the toner collection device 80. The toner collection device 80 includes the intermediate transfer unit 20 in the printer body 11. A head pipe 83 having a connection opening 831 into which the waste toner discharge pipe 60 is inserted by being pushed in is provided, and the peripheral portion of the circular lid 62 on the front end side of the waste toner discharge pipe 60 is disposed around the entire circumference. An annular inclined edge surface 625 is formed so as to taper.

  According to such a configuration, the intermediate transfer unit 20 formed by unitizing the intermediate transfer belt 21 and the belt cleaning device 30 drawn out from the printer main body 11 is pushed into the printer main body 11, thereby cleaning the belt. The waste toner carrying pipe 60 of the apparatus 30 is inserted into the connection opening 831 provided in the head pipe 83 of the toner collecting apparatus 80, and thus the belt cleaning apparatus 30 is removed by performing the cleaning process on the intermediate transfer unit 20. The waste toner can be collected in the toner collection device 80 through the waste toner carry-out pipe 60 and the head pipe 83.

  In addition, an annular inclined edge surface 625 that is tapered toward the entire periphery is formed on the peripheral edge portion on the front end side of the waste toner discharge pipe 60, and therefore, between the waste toner discharge pipe 60 and the connection opening 831. Even if there is a misalignment, if the misalignment is within the range of the annular inclined edge surface 625, any portion of the annular inclined edge surface 625 is connected to the connection opening 831 in a state where the center is out of alignment. Contact the edge. Therefore, thereafter, by pushing in the waste toner discharge pipe 60, the annular inclined edge surface 625 is fitted into the connection opening 831 while receiving a force from the edge of the connection opening 831 in the direction in which the misalignment is corrected. Therefore, when the intermediate transfer unit 20 is pushed into the printer main body 11, the waste toner carry-out pipe 60 can be fitted into the connection opening 831 with the misalignment eliminated.

  In this way, by forming the annular inclined edge surface 625 that is tapered to the entire periphery at the peripheral edge portion on the front end side of the waste toner discharge pipe 60, the intermediate transfer unit 20 that has been once drawn out is connected to the printer main body 11. The waste toner carry-out pipe 60 can be reliably inserted into the connection opening 831 simply by performing an operation of pushing in. Therefore, unlike the conventional case, the troublesome operation of adjusting the strength and direction of the pushing force according to the situation while comparing the front end side of the waste toner carrying pipe 60 and the connection opening 831 is not required, and therefore the intermediate transfer belt. The operability of the insertion / removal operation of the intermediate transfer unit 20 formed by unitizing the belt 21 and the belt cleaning device 30 with respect to the printer main body 11 can be improved.

  Further, at least a pair of guide projecting pieces 626 extending outward in the pipe center direction is provided on the further distal end side of the annular inclined edge surface 625, and the outer edge surface of each guide projecting piece 626 has a distal end. Since the slope is set so that the distance from the pipe core gradually decreases toward the pipe, the annular inclined edge surface 625 of the closing disk 622 of the waste toner carrying-out pipe 60 with respect to the edge of the connection opening 831 is formed. The interference range is widened, and even if a considerably large misalignment exists between the waste toner carry-out pipe 60 and the connection opening 831, it is possible to sufficiently cope with the elimination of the misalignment.

  Further, since the guide protrusions 626 are provided at positions above and below the annular inclined edge surface 625, the belt cleaning device 30 attached to the intermediate transfer unit 20 has a side on which the waste toner discharge pipe 60 protrudes. Although there is a tendency to incline downward due to its weight, it is possible to cope with the up and down inclination of the waste toner carrying pipe 60 by providing the guide protrusion 626 at the upper and lower positions of the annular inclined edge surface 625.

  The present invention is not limited to the above embodiment, and includes the following contents.

  (1) In the above embodiment, the printer 10 has been described as an example of the image forming apparatus. However, the image forming apparatus is not limited to the printer 10 and may be a copying machine or a facsimile machine.

  (2) In the above embodiment, the guide protrusions 626 provided at the tip of the circular lid 62 of the waste toner discharge pipe 60 are provided as a pair in the upper and lower directions, but are limited to a pair in particular. The guide protrusions 626 corresponding to the number of clothes may be provided at equal pitches in the circumferential direction.

  (3) In the above embodiment, the annular inclined edge surface 625 formed over the entire circumference is provided at the tip of the circular lid 62, but the present invention provides the entire circumference at the tip of the circular lid 62. It is not limited to forming the annular inclined edge surface 625 extending over the surface, and may be provided at least on the lower surface side. The reason for this is that the belt cleaning device 30 has a waste toner discharge pipe 60 protruding from the rear end of the casing 31 and tends to incline so that the rear end is inclined downward. This is because it is possible to cope with this by providing a surface.

1 is a cross-sectional view for explaining an internal structure of an embodiment of an image forming apparatus to which a cleaning device according to the present invention is applied. FIG. 2 is an explanatory diagram showing an extracted intermediate transfer unit including the intermediate transfer belt and the like in FIG. 1. FIG. 4 is a perspective view schematically illustrating the relative positional relationship between the intermediate saddle-shaped frame and the belt cleaning device as viewed from the front side, and (A) shows a waste toner discharge pipe connected to a waste toner recovery pipe. The state immediately before (B) shows a state in which the waste toner carrying pipe is connected to the waste toner collecting pipe. FIG. 3 is a perspective view schematically illustrating the relative positional relationship between the intermediate saddle-shaped frame and the belt cleaning device as viewed from the rear side, and (A) shows a waste toner discharge pipe connected to a waste toner recovery pipe. The state immediately before (B) shows a state in which the waste toner carrying pipe is connected to the waste toner collecting pipe. It is a perspective view which shows one Embodiment of a belt cleaning apparatus. FIG. 6 is a partially enlarged exploded view of FIG. 5 illustrating an embodiment of a waste toner carrying pipe and a shutter member. FIG. 7 is an assembled perspective view of a waste toner carrying pipe and a shutter member shown in FIG. 6. FIG. 6 is a cross-sectional view for explaining a connection operation of the belt cleaning device to the toner recovery device, (A) is a state immediately before the waste toner carrying pipe of the belt cleaning device is connected to the head pipe of the toner recovery device. The state (B) shows a state where the waste toner carrying pipe of the belt cleaning device is connected to the head pipe of the toner collecting device.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Printer 101 Paper discharge conveyance path 11 Printer main body 111 Back wall 111a Through window 112 Left side wall 113 Right side wall 114 Positioning pin 12 Paper feed part 121 Paper cassette 122 Pickup roller 13 Image forming part 13M Magenta unit 13C Cyan unit 13Y Unit for yellow 13K Unit 131 for black Photosensitive drum (image carrier)
132 Charger 133 Exposure Device 134 Development Device 135 Toner Container 136 Drum Cleaning Device 137 Secondary Transfer Roller 14 Fixing Unit 141 Fixing Roller 142 Pressure Roller 143 Discharge Roller Pair 15 Discharge Unit 151 Discharge Tray 152 Discharge Port 20 Intermediate Transfer Unit 201 Intermediate frame 202 Front frame plate 202a Handle 202b Locking hole 203 Rear frame plate 203a Long hole 204 Left frame plate 205 Right frame plate 206 Positioning hole 21 Intermediate transfer belt 22 Primary transfer roller 23 Drive roller 230 For belt drive Motor 231 Drive shaft 24 Drive roller 25 Press roller 26 Bending roller 27 Upper tension roller 28 Lower tension roller 29 Rail member 291 Fixed rail 292 Movable rail 30 Belt cleaning device 3 DESCRIPTION OF SYMBOLS 1 Casing 311 Back board 312 Front board 32 Front latching protrusion 33 Back latching protrusion 38 Gear mechanism 39 Brush drive motor 40 Brush roller 41 Brush shaft 42 Brush hair 43 Blade 45 Charging roller 50 Screw member 51 Screw shaft 511 Annular Groove 52 Spiral fin 60 Waste toner discharge pipe 61 Conveying pipe main body 611 Large diameter portion 612 Medium diameter portion 613 Small diameter portion 614 Waste toner discharge port 615 Non-rotating groove 616 Conveying pipe main body 62 Circular lid body 621 Lid body main body 622 Closing disc 623 Anti-rotation protrusion 624 Inner cylinder 625 Annular inclined edge surface (inclined edge surface)
626 Guide protrusion 63 Stopper 70 Shutter member 71 Shutter cylinder 72 Flange 73 Coil spring 80 Toner recovery device 81 Waste toner storage container 82 Waste toner recovery pipe 83 Head pipe 831 Connection opening (waste toner receiving port)
P paper

Claims (3)

Intermediate transfer that can be inserted into and removed from the main body of the apparatus, comprising an intermediate transfer belt onto which the toner image from the image carrier is transferred and a cleaning device that performs a cleaning process on the surface of the intermediate transfer belt. Unit,
A toner collecting device that collects waste toner removed from the intermediate transfer belt by the cleaning device;
The cleaning device has a waste toner discharge pipe for transporting waste toner removed from the intermediate transfer belt toward the toner collection device,
The toner recovery device includes a waste toner recovery pipe having a waste toner receiving port into which the waste toner discharge pipe is inserted when the intermediate transfer unit is pushed into the apparatus main body.
An image forming apparatus characterized in that an annular inclined edge surface that is inclined in a tapered manner is formed at a peripheral edge portion on a front end side of the waste toner discharge pipe.   At the further tip side of the annular inclined edge surface, at least a pair of guide projecting pieces extending outward in the pipe center direction is projected, and the outer edge surface of each guide projecting piece is directed toward the tip. The image forming apparatus according to claim 1, wherein an inclination is set so that a distance from the pipe core gradually decreases. The image forming apparatus according to claim 2, wherein the guide protrusions are provided at positions above and below the annular inclined edge surface, respectively.

Images