JP2019078980A - Waste toner conveying device and image forming apparatus - Google Patents

Abstract

To provide a waste toner conveying device and an image forming apparatus that can inhibit the generation of abnormal noise.SOLUTION: A waste toner conveying device according to one embodiment comprises: a housing that stores a waste toner; a coil auger 73 in a screw shape that is arranged inside the housing and stirs and mixes the waste toner; and screw extension means 90 that extends the coil auger 73 in an axial direction D of the coil auger 73 at one end in the axial direction D. The screw extension means 90 switches between an extension state for extending the coil auger 73 and an extension release state for releasing the extension of the coil auger 73.SELECTED DRAWING: Figure 6

Description

  The present invention relates to a waste toner conveying device for conveying collected waste toner, and an image forming apparatus.

  An image forming apparatus forms an image on a print medium using a developer containing toner. The toner is contained in a tank, and is conveyed to the photosensitive member when forming an image. The toner is transferred from the photoreceptor to the print medium, but some toner remains on the photoreceptor. The remaining toner is collected as waste toner by the cleaning device.

  JP-A-2015-225173 describes a toner conveyance device provided with a process cartridge unit. The toner conveyance device includes a conveyance path in which the waste toner is conveyed, a screw-like conveyance member provided inside the conveyance path to convey the waste toner, and a drive source that rotates the conveyance member. The transport path includes a first transport path located outside the process cartridge unit and a second transport path provided inside the process cartridge unit.

  When the conveyance member is rotated by the drive of the drive source, the toner positioned in the second conveyance path is conveyed toward the first conveyance path, and the toner is discharged to the outside of the toner conveyance device through the first conveyance path. The transport member has an axis extending along the transport path, and a helical member helically extending in the direction in which the axis extends. The helical member is fixed to the shaft at at least three points of its both ends and a portion located between the two ends.

JP, 2015-225173, A

  In the toner transport device described above, since the spiral member extends long along the transport path, a slack occurs in the spiral member, and the slack can cause the spiral member to contact the inner wall surface of the transport path. When the helical member rotates in contact with the inner wall surface, noise may be generated from the contact portion between the helical member and the inner wall surface.

  An object of the present invention is to provide a waste toner conveying device and an image forming apparatus capable of suppressing the generation of abnormal noise.

  The waste toner conveyance device according to the present invention includes a first housing for containing waste toner, a screw-shaped waste toner conveyance member disposed inside the first housing to agitate and convey the waste toner, and a waste toner conveyance member. Screw extending means for axially extending the waste toner conveying member at one end in the axial direction. The screw extension means switches between an extension state in which the waste toner conveyance member is extended and an extension release state in which the extension of the waste toner conveyance member is released.

  The waste toner conveyance device includes a first housing for containing waste toner, and a screw-shaped waste toner conveyance member is provided inside the first housing. The waste toner conveying member is stretched by screw extending means provided at one end of the waste toner conveying member in the axial direction. Therefore, when the waste toner conveyance member is stretched by the screw extending means, slack of the waste toner conveyance member can be suppressed and the posture of the waste toner conveyance member can be stabilized. Therefore, since the contact of the waste toner conveying member with the inner wall surface of each part can be suppressed by suppressing the slack of the waste toner conveying member, the generation of the abnormal noise due to the contact of the waste toner conveying member can be suppressed. it can. In addition, if the waste toner conveying member is always pulled, there is a concern that a part or the like supporting the waste toner conveying member may be deformed or damaged due to creep. However, the screw extension means switches between the extension state in which the waste toner conveyance member is extended and the extension release state in which the extension of the waste toner conveyance member is released. Therefore, it is possible to suppress deformation and damage of the part due to creep.

  Further, the waste toner conveyance member may be axially expandable, and the outer diameter of the waste toner conveyance member when the waste toner conveyance member is extended may be smaller than the inner diameter of the first housing. In this case, the outer diameter of the waste toner conveyance member extended in the axial direction is smaller than the inner diameter of the first housing. Therefore, the extended waste toner conveyance member can be prevented from coming into contact with the inner wall surface of the first housing, so that the generation of abnormal noise in the extended state can be suppressed more reliably.

  The screw extension means may include a second housing for receiving the waste toner stirred and transported by the waste toner transport member, and an opening and closing member for opening and closing the waste toner discharge port to the second housing. The screw extension means may extend the waste toner conveyance member when the opening and closing member opens the discharge port, and release the extension of the waste toner conveyance member when the opening and closing member closes the discharge port. In this case, the expansion and contraction of the waste toner conveyance member by the screw expansion means can be interlocked with the opening and closing of the discharge port. Further, the discharge port can be opened to operate the waste toner conveyance device, and the waste toner conveyance member can be extended in a state in which the waste toner can be received. Further, the waste toner conveyance member can be released from the extension state while the waste toner conveyance device is kept stationary and the discharge port is closed. Therefore, the waste toner conveying member can be extended when the waste toner can be discharged to the discharge port, and the extension can be released when the discharge can not be performed. Therefore, the extension state and the extension release state can be switched appropriately.

  In addition, the screw extension means may include a screw support member that supports an axial end of the waste toner conveyance member and is movable in the axial direction. The opening and closing member may rotate around the axis of the waste toner conveyance member to open and close the discharge port. The screw extension means may push the screw support member in the axial direction to extend the waste toner conveyance member when the opening and closing member is rotated to open the discharge port. In this case, a rotary opening and closing member can be used as the screw extending means. Further, when the discharge port is opened by the rotation of the opening and closing member, the screw extending means pushes out the screw supporting member to extend the waste toner conveying member. Accordingly, the rotation operation of the opening and closing member and the expansion and contraction of the waste toner conveyance member can be interlocked with each other. Therefore, in the case of using the rotary opening and closing member, it is possible to appropriately switch the extension state and the extension release state of the waste toner conveyance member.

  The waste toner conveyance device may further include an elastic body for biasing the opening and closing member in a direction to close the outlet, between the opening and closing member and the duct extending from the first housing and having the outlet formed. In this case, the elastic body biases the opening and closing member in the direction in which the discharge port is closed. Therefore, the extension of the waste toner conveyance member is released along with the closing by the opening / closing member, so that the extension released state can be reliably shifted when the extension of the waste toner conveyance member is unnecessary. Accordingly, since the elastic body can be reliably shifted to the extended release state by the biasing of the elastic body, deformation and breakage of the component due to creep can be suppressed more reliably.

  Further, a gear portion for rotating the waste toner conveying member may be provided at an end of the waste toner conveying member opposite to the screw extending means. The gear portion may extend the waste toner conveyance member in the direction opposite to the direction of extension of the screw extension means when rotating. In this case, since the waste toner conveying member is pulled in the opposite direction of the screw extending means when the gear portion rotates, the amount of pulling of the waste toner conveying member can be increased. Therefore, the slack of the waste toner conveyance member and the contact of the waste toner conveyance member with the inner wall surface can be more reliably suppressed.

  Further, the gear portion may extend the waste toner conveying member at the time of rotation in the above-described extended state. In this case, when the screw extending means is extending the waste toner conveying member, the gear portion rotates and pulls the waste toner conveying member, so that the slack of the waste toner conveying member at the time of the rotation of the gear portion is suppressed more reliably. can do.

  An image forming apparatus according to the present invention includes the above-described waste toner conveying device. Therefore, the same effects as those of the above-described waste toner conveying devices can be obtained.

  According to the present invention, the generation of abnormal noise can be suppressed.

FIG. 1 is a schematic configuration view of an image forming apparatus provided with a waste toner conveyance device according to an embodiment. FIG. 2 is an exploded perspective view of the waste toner conveyance device according to the embodiment. FIG. 3 is a cross-sectional view showing an internal structure of the waste toner conveyance device of FIG. 2; FIG. 3 is a view showing a state in which a shutter of the waste toner conveyance device of FIG. 2 closes a discharge port. (A) is the figure which looked at the state which the shutter of FIG. 4 obstruct | occluded the discharge port from the direction different from FIG. (B) is a figure which omitted the waste toner collection container from Fig.5 (a). It is a figure which shows the state which the shutter of FIG. 4 open | released the discharge port. (A) is the figure which looked at the state which the shutter of FIG. 4 obstruct | occluded the discharge port from the direction different from FIG. (B) is a figure which omitted the waste toner collection container from Fig.7 (a).

  Hereinafter, embodiments of a waste toner conveyance device and an image forming apparatus according to the present invention will be described in detail with reference to the drawings. In the description of the drawings, the same or corresponding elements will be denoted by the same reference symbols, and overlapping descriptions will be omitted as appropriate. In addition, the drawings may be drawn in an exaggerated manner for easy understanding, and dimensions, angles and the like are not limited to those described in the drawings.

  The image forming apparatus 1 according to the present embodiment is an apparatus for forming a color image using each color of magenta, yellow, cyan, and black. As shown in FIG. 1, the image forming apparatus 1 includes a recording medium conveyance unit 10 for conveying a sheet P, a developing device 20 for developing an electrostatic latent image, and a transfer unit for secondarily transferring a toner image to the sheet P. A photosensitive drum 40, which is an electrostatic latent image carrier on which an image is formed on the circumferential surface, and a fixing unit 50 for fixing a toner image on a sheet P are provided.

  The recording medium conveyance unit 10 accommodates the sheet P as a recording medium on which an image is formed, and conveys the sheet P onto the conveyance path R1. The sheets P are stacked and stored in the cassette K. The recording medium conveyance unit 10 causes the sheet P to reach the secondary transfer area R2 via the conveyance path R1 at the timing when the toner image transferred onto the sheet P reaches the secondary transfer area R2.

  Four developing devices 20 are provided for each color. Each developing device 20 includes a developing roller 21 that causes the photosensitive drum 40 to carry toner. In the developing device 20, the toner and the carrier are adjusted to have a desired mixing ratio, and the mixture is further mixed and stirred to uniformly disperse the toner, thereby adjusting the developer to which the optimum charge amount is applied. The developer is carried on the developing roller 21. Then, when the developer is conveyed to the area facing the photosensitive drum 40 by the rotation of the developing roller 21, the toner of the developer carried on the developing roller 21 is formed on the circumferential surface of the photosensitive drum 40. The electrostatic latent image is developed and developed. Further, in the developing device 20, the carrier together with the toner is supplied to the inside of the toner tank N at the time of the toner supplying operation in order to keep the charge amount of the developing agent constant, and the developer deteriorated in the developing device 20 is discharged. The trickle development method is adopted. Inside the developing device 20, the deteriorated developer is accommodated in a waste toner recovery device.

  The transfer unit 30 conveys the toner image formed by the developing device 20 to a secondary transfer area R2 for secondary transfer onto the sheet P. The transfer unit 30 includes a transfer belt 31, suspension rollers 31a, 31b, 31c and 31d for suspending the transfer belt 31, a primary transfer roller 32 for holding the transfer belt 31 with the photosensitive drum 40, and a transfer belt with a suspension roller 31d. And a secondary transfer roller 33 for sandwiching 31.

  The transfer belt 31 is an endless belt cyclically moved by the suspension rollers 31a, 31b, 31c, and 31d. The primary transfer roller 32 is provided to press the photosensitive drum 40 from the inner peripheral side of the transfer belt 31. The secondary transfer roller 33 is provided to press the suspension roller 31 d from the outer peripheral side of the transfer belt 31.

  Four photosensitive drums 40 are provided for each color. The four photosensitive drums 40 are provided along the moving direction of the transfer belt 31. On the periphery of the photosensitive drum 40, a developing device 20, a charging roller 41, an exposure unit 42, and a waste toner conveying device 70 including a cleaning unit are provided. The waste toner conveyance device 70 will be described in detail later.

  The charging roller 41 uniformly charges the surface of the photosensitive drum 40 to a predetermined potential. The exposure unit 42 exposes the surface of the photosensitive drum 40 charged by the charging roller 41 in accordance with the image formed on the sheet P. As a result, the potential of the portion of the surface of the photosensitive drum 40 exposed by the exposure unit 42 changes, and an electrostatic latent image is formed. The four developing devices 20 develop the electrostatic latent image formed on the photosensitive drum 40 by the toner supplied from the toner tank N provided opposite to each developing device 20 to generate a toner image . Inside of each toner tank N, toners and carriers of magenta, yellow, cyan and black are filled respectively.

  The fixing unit 50 causes the toner image, which is secondarily transferred from the transfer belt 31 to the paper P, to adhere to the paper P and fix it. The fixing unit 50 includes a heating roller 51 for heating the sheet P and a pressure roller 52 for pressing the heating roller 51. The heating roller 51 is formed in a cylindrical shape, and the heating roller 51 is internally provided with a heat source such as a halogen lamp. A fixing nip portion, which is a contact area, is provided between the heating roller 51 and the pressure roller 52. By causing the sheet P to pass through the fixing nip portion, the toner image is fused and fixed to the sheet P. Further, the image forming apparatus 1 is provided with discharge rollers 61 and 62 for discharging the sheet P on which the toner image is fixed by the fixing unit 50 to the outside of the apparatus.

  Next, the operation of the image forming apparatus 1 will be described. When an image signal of an image to be recorded is input to the image forming apparatus 1, the control unit of the image forming apparatus 1 uniformly charges the surface of the photosensitive drum 40 to a predetermined potential by the charging roller 41 based on the received image signal. To charge. Thereafter, the surface of the photosensitive drum 40 is irradiated with laser light by the exposure unit 42 to form an electrostatic latent image.

  In the developing device 20, the electrostatic latent image is developed to form a toner image. The toner image is primarily transferred from the photosensitive drum 40 to the transfer belt 31 in a region where the photosensitive drum 40 and the transfer belt 31 face each other. Toner images formed on the four photosensitive drums 40 are sequentially laminated on the transfer belt 31 to form one laminated toner image. The laminated toner image is secondarily transferred onto the sheet P conveyed from the recording medium conveyance unit 10 in the secondary transfer area R2 where the suspension roller 31d and the secondary transfer roller 33 face each other. The sheet P on which the laminated toner image is secondarily transferred is conveyed to the fixing unit 50. The layered toner image is fused and fixed to the sheet P by heating and pressing the sheet P while passing the sheet P between the heating roller 51 and the pressure roller 52. Thereafter, the sheet P is discharged to the outside of the image forming apparatus 1 by the discharge rollers 61 and 62.

  Next, the waste toner conveyance device 70 will be described. As shown in FIG. 2, the waste toner conveying device 70 includes a cleaning blade 71. The cleaning blade 71 recovers the toner remaining on the photosensitive drum 40 after the toner image formed on the photosensitive drum 40 is primarily transferred to the transfer belt 31.

  As shown in FIGS. 2 and 3, the waste toner conveyance device 70 includes a housing 72 (first housing) in which the waste toner collected by the cleaning blade 71 is stored, and a screw for conveying the waste toner in the housing 72. A coil auger 73 (waste toner conveying member) having a shape, a gear portion 74 for rotating the photosensitive drum 40 and the coil auger 73, and a cylindrical duct 75 extending from the housing 72 to the opposite side of the gear portion 74 are provided.

  The housing 72 is in the form of a box extending in the axial direction D of the photosensitive drum 40. Here, the axial direction D is the direction in which the photosensitive drum 40 and the screw-shaped coil auger 73 extend, and coincides with the direction in which the imaginary rotation axis L of the coil auger 73 extends. The housing 72 receives waste toner scraped off the photosensitive drum 40 by the cleaning blade 71 and stores the waste toner.

  The coil auger 73 transports the waste toner accommodated in the housing 72 in the axial direction D by rotating around the rotation axis L. The coil auger 73 is expandable in the axial direction D. The coil auger 73 is made of metal. The coil auger 73 extends in the axial direction D inside the housing 72 and extends in the axial direction D from the housing 72. That is, one end 73 a of the coil auger 73 in the axial direction D extends to the outside of the housing 72. Further, the outer diameter of the coil auger 73 at the time of extension is smaller than the inner diameter of the housing 72. The coil auger 73 is a non-axial screw having a screw shape, and a linear member is formed into a spiral shape.

  The gear portion 74 includes an input gear 74a rotating about the same axis as the rotation axis of the photosensitive drum 40, an idler gear 74b meshing with the input gear 74a, and a screw gear 74c meshing with the idler gear 74b and rotating the coil auger 73 including. The input gear 74a receives a rotational driving force from the motor and rotates, and the photosensitive drum 40 and the idler gear 74b rotate with this rotation.

  The idler gear 74b rotates in the opposite direction to the input gear 74a, and the screw gear 74c rotates as the idler gear 74b rotates. The screw gear 74 c rotates in the opposite direction to the idler gear 74 b and rotates around the rotation axis L of the coil auger 73. The idler gear 74 b or the screw gear 74 c of the gear portion 74 may include a helical gear that generates a thrust force in a direction in which the coil auger 73 is pulled. In this case, the coil auger 73 can be extended when the gear portion 74 rotates.

  The duct 75 protrudes from the housing 72 in the axial direction D. A coil auger 73 is passed through the inside of the duct 75, and accommodates the waste toner transported from the housing 72 by the coil auger 73. The duct 75 includes a first cylindrical portion 75a extending from the housing 72, a flange portion 75b expanding from the first cylindrical portion 75a, and a second cylindrical portion 75c opposite to the first cylindrical portion 75a of the flange portion 75b. And. The second cylindrical portion 75c has a discharge port 75d for discharging the waste toner in the duct 75, and the discharge port 75d has, for example, a rectangular shape. A shutter opening / closing spring 80 (elastic member) described later is wound around the flange portion 75b side of the discharge port 75d on the outer periphery of the second cylindrical portion 75c.

  The waste toner conveying device 70 further includes a waste toner collecting container 76 (second housing) having a receiving port 76a for receiving the waste toner conveyed by the coil auger 73, and a screw holder 77 (screw screw) supporting one end of the coil auger 73. A support member), a tension cam 78 (screw support member) for moving the screw holder 77 in the axial direction D, a rotary shutter 79 (opening and closing member) for opening and closing the discharge port 75d, and the shutter opening spring 80 described above Equipped with

  As shown in FIGS. 3 and 4, the waste toner recovery container 76 is a box-shaped waste toner recovery box, and receives waste toner transported by the coil auger 73 from the receiving port 76a. The waste toner recovery container 76 has a protrusion 76 b projecting toward the housing 72 at the receiving port 76 a and a recess 76 c recessed in the axial direction D at the receiving port 76 a. The projecting end 76 d of the projecting portion 76 b and the bottom surface 76 e of the recess 76 c are inclined with respect to the axial direction D. The bottom surface 76 e is curved and extends in an arc shape.

  The screw holder 77 is supported movably and non-rotatably in the axial direction D with respect to the waste toner collecting container 76. The screw holder 77 is disposed inside the waste toner recovery container 76 and supports one end 73 a of the coil auger 73 in the axial direction D. The screw holder 77 has a plate-like portion 77a extending along a plane orthogonal to the axial direction D, and a protrusion 77b projecting from the plate-like portion 77a toward the housing 72 side. One end 73a of the coil auger 73 is wound around and fixed to the projecting portion 77b.

  As shown in FIG. 4, FIG. 5 (a) and FIG. 5 (b), the tension cam 78 has a tubular shape and accommodates the screw holder 77. The screw holder 77 is fitted in the tension cam 78. The tension cam 78 is movable in the axial direction D together with the screw holder 77, and can not rotate with respect to the waste toner collecting container 76. The tension cam 78 has an inclined surface 78 c on which the shutter 79 abuts from the housing 72 side.

  The shutter 79 covers the end of the duct 75 in the axial direction D, and is supported rotatably relative to the duct 75 and immovable along the axial direction D. The shutter 79 has a cylindrical portion 79a through which the coil auger 73 and the duct 75 are inserted, a first fitting portion 79b fitted into the waste toner collecting container 76, and a second fitting portion 79c fitted into the tension cam 78. . The cylindrical portion 79a is formed in a cylindrical shape, and has an opening 79e (see FIGS. 2 and 3) communicating with the discharge port 75d when it is rotated. The opening 79e is, for example, rectangular.

  The first fitting portion 79b is provided on the housing 72 side of the cylindrical portion 79a, and the second fitting portion 79c is provided on the tension cam 78 side of the cylindrical portion 79a. The first fitting portion 79 b is fitted into the recess 76 c of the waste toner collecting container 76, whereby the waste toner collecting container 76 is attached to the shutter 79. The first fitting portion 79b has an inclined surface 79d in surface contact with the bottom surface 76e of the recess 76c. The second fitting portion 79 c has an inclined surface 79 f in surface contact with the inclined surface 78 c of the tension cam 78 and inclined with respect to the axial direction D.

  The shutter 79 is a rotary shutter that opens and closes the waste toner discharge port 75 d to the waste toner collection container 76 by rotation. 4, 5 (a) and 5 (b) show a state in which the shutter 79 closes the outlet 75d, and FIGS. 6, 7 (a) and 7 (b) show the shutter 79 being closed. A state where the discharge port 75d is opened is shown. As shown in FIGS. 4, 5A and 5B, when the waste toner collecting container 76 is separated from the shutter 79, the shutter 79 closes the discharge port 75d. Specifically, the position of the opening 79e and the position of the discharge port 75d in the rotational direction are offset from each other. At this time, the cylindrical portion 79a of the shutter 79 covers the discharge port 75d, and the inclined surface 79f of the second fitting portion 79c is in surface contact with the inclined surface 78c of the tension cam 78.

  The shutter opening and closing spring 80 is wound around the outer periphery of the second cylindrical portion 75 c of the duct 75 as described above. The shutter opening and closing spring 80 is, for example, a torsion spring that biases the shutter 79 in the rotational direction. The shutter open / close spring 80 biases the shutter 79 in a direction to close the outlet 75 d.

  The waste toner conveyance device 70 includes a screw extending unit 90 that switches between an extended state in which the coil auger 73 is stretched and an extended state in which the coil auger 73 is released. The screw extension means 90 includes the waste toner collecting container 76, the screw holder 77, the tension cam 78 and the shutter 79 described above.

  The extension state of the coil auger 73 by the screw extension means 90 will be described. As shown in FIGS. 4, 5A and 5B, when the waste toner recovery container 76 is separated from the shutter 79, the coil auger 73 is in the extension released state. Then, when the waste toner collecting container 76 is attached to the shutter 79, the projecting part 76 b of the waste toner collecting container 76 abuts on the first fitting part 79 b of the shutter 79. By this contact, the inclined surface 79d of the first fitting portion 79b moves relative to the projecting end 76d of the projecting portion 76b, whereby the shutter 79 rotates with respect to the duct 75.

  As shown in FIGS. 6, 7 (a) and 7 (b), with the rotation of the shutter 79, the first fitting portion 79b fits into the recess 76c, and the opening 79e communicates with the discharge port 75d. The shutter 79 opens the outlet 75d. Thus, the attachment of the waste toner recovery container 76 and the opening of the discharge port 75d are interlocked.

  Further, with the rotation of the shutter 79, the inclined surface 79f of the second fitting portion 79c rotates with respect to the inclined surface 78c of the tension cam 78, and the shutter 79 moves the tension cam 78 in the axial direction D (FIG. 6, FIG. 7). (A) and the right side of the sheet of FIG. 7 (b)). When the tension cam 78 is pushed out in the axial direction D, the screw holder 77 is pushed out together with the tension cam 78 in the axial direction D, and the pushing of the screw holder 77 causes the coil auger 73 to be stretched in the axial direction D.

  As described above, as the shutter 79 rotates with respect to the duct 75 and the tension cam 78, and the tension cam 78 and the screw holder 77 are pushed out in the axial direction D, the screw extending means 90 extends the coil auger 73. Transition to extension state. At this time, the gear portion 74 rotates, and the gear portion 74 extends the coil auger 73 in the direction opposite to the extension direction of the screw extension means 90.

  On the other hand, when removing the waste toner collecting container 76 from the shutter 79 by replacing the waste toner collecting container 76, the shutter 79 is rotated in the reverse direction by the biasing force of the shutter opening and closing spring 80 to close the discharge port 75d. The tension cam 78 and the screw holder 77 are pulled back to the shutter 79 side. As the screw extension means 90 releases the extension of the coil auger 73 by this pulling back, it shifts to the extension released state. At this time, extension of the coil auger 73 is released and the coil auger 73 is contracted, whereby the waste toner in the housing 72 and the duct 75 can be stirred.

  Next, the functions and effects of the waste toner conveyance device 70 and the image forming apparatus 1 according to the present embodiment will be described in more detail. The image forming apparatus 1 and the waste toner conveyance device 70 include a housing 72 for containing waste toner, and a screw-shaped coil auger 73 is provided inside the housing 72. The coil auger 73 is stretched by screw extension means 90 provided at one end of the coil auger 73 in the axial direction D. Therefore, when the coil auger 73 is stretched by the screw extension means 90, the slack of the coil auger 73 can be suppressed and the posture of the coil auger 73 can be stabilized.

  Therefore, since the contact of the coil auger 73 with the inner wall surface of each component can be suppressed by suppressing the slack of the coil auger 73, the generation of abnormal noise due to the contact of the coil auger 73 can be suppressed. In addition, if the coil auger 73 is always pulled, there is a concern that a part or the like supporting the coil auger 73 may be deformed or damaged due to creep. However, the screw extension means 90 switches between the extension state in which the coil auger 73 is extended and the extension release state in which the coil auger 73 is released. Therefore, it is possible to suppress deformation and damage of the part due to creep.

  The coil auger 73 is expandable in the axial direction D, and the outer diameter of the coil auger 73 when the coil auger 73 is extended is smaller than the inner diameter of the housing 72. That is, the outer diameter of the coil auger 73 extended in the axial direction D is smaller than the inner diameter of the housing 72. Therefore, since the extended coil auger 73 can be prevented from coming into contact with the inner wall surface of the housing 72, generation of abnormal noise in the extended state can be suppressed more reliably.

  The screw extension means 90 also includes a waste toner recovery container 76 for receiving the waste toner stirred and transported by the coil auger 73, and a shutter 79 for opening and closing the waste toner discharge port 75d to the waste toner recovery container 76. It is. The screw extension means 90 extends the coil auger 73 when the shutter 79 opens the discharge port 75d, and releases the extension of the coil auger 73 when the shutter 79 closes the discharge port 75d. Thus, the expansion and contraction of the coil auger 73 by the screw extension means 90 can be interlocked with the opening and closing of the discharge port 75d.

  Further, the discharge port 75d can be opened to operate the waste toner conveyance device 70, and the coil auger 73 can be extended in a state in which the waste toner can be received. Furthermore, the extension of the coil auger 73 can be released in a state where the waste toner conveyance device 70 is stopped and the discharge port 75 d is closed. Therefore, the coil auger 73 can be extended when the waste toner can be discharged to the discharge port 75d, and the extension can be released when the discharge can not be performed. Therefore, the extension state and the extension release state can be switched appropriately.

  The screw extension means 90 also includes a screw holder 77 and a tension cam 78 supporting one end of the coil auger 73 in the axial direction D. The shutter 79 rotates around the axis of the coil auger 73 to open and close the outlet 75 d. The screw extending means 90 pushes the tension cam 78 in the axial direction D to extend the coil auger 73 when the shutter 79 is rotated to open the discharge port 75d. Thus, a rotary shutter 79 can be used as the screw extension means 90.

  Further, when the discharge port 75d is opened by the rotation of the shutter 79, the screw extension means 90 pushes the tension cam 78 to extend the coil auger 73. Therefore, the rotational movement of the shutter 79 and the expansion and contraction of the coil auger 73 can be interlocked. Therefore, when the rotary shutter 79 is used, the extended state and the extended release state of the coil auger 73 can be switched appropriately.

  In addition, the waste toner conveying device 70 is a shutter opening / closing spring 80 for urging the shutter 79 in a direction to close the discharge port 75 d between the shutter 79 and the duct 75 extending from the housing 72 and having the discharge port 75 d formed. Equipped with That is, the shutter opening and closing spring 80 biases the shutter 79 in the direction in which the discharge port 75d is closed. Therefore, since the extension of the coil auger 73 is released along with the closing by the shutter 79, when the extension of the coil auger 73 is unnecessary, the state can be reliably shifted to the extension released state. Therefore, since the state can be reliably shifted to the extended release state by the biasing of the shutter open / close spring 80, deformation and breakage of the component due to creep can be suppressed more reliably.

  Further, a gear portion 74 for rotating the coil auger 73 is provided at the end of the coil auger 73 opposite to the screw extension means 90. The gear portion 74 extends the coil auger 73 in the direction opposite to the direction of extension of the screw extension means 90 when rotating. Therefore, since the coil auger 73 is pulled in the opposite direction of the screw extending means 90 when the gear portion 74 rotates, the amount of pulling of the coil auger 73 can be increased. Therefore, the slack of the coil auger 73 and the contact with the inner wall surface of the coil auger 73 can be suppressed more reliably.

  Further, the gear portion 74 extends the coil auger 73 at the time of rotation in the above-described extended state. Therefore, when the screw extension means 90 extends the coil auger 73, the gear portion 74 rotates and pulls the coil auger 73, so that the slack of the coil auger 73 at the time of rotation of the gear portion 74 is suppressed more reliably. be able to.

  The embodiments of the waste toner conveyance device and the image forming apparatus according to the present invention have been described above. However, the waste toner conveying device and the image forming apparatus according to the present invention are not limited to the above-described embodiments, and are modified or applied to other things without departing from the scope of the invention described in each claim. It may be one. That is, the configuration of each part of the waste toner conveyance device and the image forming apparatus can be appropriately changed without changing the above gist.

  For example, although the above-mentioned embodiment explained gear part 74 provided with input gear 74a, idler gear 74b, and screw gear 74c, composition of a gear part which rotationally drives coil auger 73 can be changed suitably. That is, the number, shape, size, material, and arrangement of the gears in the gear portion can be changed as appropriate.

  In the above embodiment, the duct 75 having the first cylindrical portion 75a, the flange portion 75b and the second cylindrical portion 75c and the waste toner collecting container 76 having the projecting portion 76b and the concave portion 76c have been described. The shape, size, material, and arrangement of the toner recovery container can be changed as appropriate.

  Further, in the above embodiment, the screw extending unit 90 including the waste toner collecting container 76, the screw holder 77, the tension cam 78, and the shutter 79 has been described, but the configuration of the screw extending unit can be appropriately changed. In addition, the shapes, sizes, materials, and arrangements of the screw holder, the tension cam and the shutter can be appropriately changed. Furthermore, the screw holder 77 and the tension cam 78 may be replaced by an integral screw support member, or the shutter 79 may be replaced by a non-rotational shutter. In addition, the shape, size, number, material, and arrangement of the shutter opening and closing spring can be appropriately changed.

  Moreover, in the above-mentioned embodiment, the example which the expansion-contraction of the coil auger 73 by the screw extending means 90 interlock | cooperates with opening and closing of the discharge port 75d was demonstrated. However, the expansion and contraction of the coil auger 73 may not be interlocked with the opening and closing of the discharge port 75d, and may be interlocked with another operation on the waste toner conveyance device or the image forming apparatus, for example. In addition, the extension and contraction of the coil auger 73 may be performed independently without being interlocked with another operation.

  Further, in the above-described embodiment, an example in which the waste toner conveyance member is the coil auger 73 made of a metal wire has been described. However, the shape, size, material, number, and arrangement of the waste toner conveyance member can be changed as appropriate. For example, in place of the coil auger 73, a waste toner conveyance member in which a metal flat plate is arranged in a spiral may be provided.

DESCRIPTION OF SYMBOLS 1 ... image forming apparatus, 10 ... recording medium conveyance unit, 20 ... developing device, 21 ... development roller, 30 ... transfer unit, 31 ... transfer belt, 31a, 31b, 31c, 31d ... suspension roller, 32 ... primary transfer roller, 33: secondary transfer roller, 40: photosensitive drum, 41: charging roller, 42: exposure unit, 50: fixing unit, 51: heating roller, 52: pressure roller, 61: discharge roller, 70: waste toner conveyance device 71: cleaning blade 72: housing (first housing) 73: coil auger (waste toner conveyance member) 73a: one end 74: gear portion 74a: input gear 74b: idler gear 74c: screw gear 75 ... Duct, 75a: first cylindrical portion, 75b: flange portion, 75c: second cylindrical portion, 75d: discharge port, 76: waste toner recovery container Second housing), 76a: receiving port, 76b: projecting portion, 76c: recessed portion, 76d: projecting end, 76e: bottom surface, 77: screw holder (screw supporting member), 77a: plate-like portion, 77b: projecting portion, 78 ... tension cam (screw support member), 78c ... inclined surface, 79 ... shutter (opening / closing member), 79a ... cylinder part, 79b ... first fitting part, 79c ... second fitting part, 79d ... inclined surface, 79e ... Opening, 79f ... inclined surface, 80 ... shutter opening / closing spring (elastic body), 90 ... screw extension means, K ... cassette, L ... rotation axis, N ... toner tank, P ... paper, R1 ... conveyance path, R2 ... secondary Transcript area.

Claims (8)

A first housing for containing waste toner;
A screw-shaped waste toner conveying member disposed inside the first housing to agitate and convey the waste toner;
Screw extending means for extending the waste toner conveying member in the axial direction at one end in the axial direction of the waste toner conveying member;
Equipped with
The screw extension means switches between an extension state in which the waste toner conveyance member is extended and an extension release state in which the waste toner conveyance member is released.
Waste toner transport device. The waste toner conveying member is extendable and contractible in the axial direction,
The outer diameter of the waste toner transport member when the waste toner transport member is expanded is smaller than the inner diameter of the first housing,
The waste toner conveying device according to claim 1. The screw extension means includes a second housing for receiving the waste toner stirred and transported by the waste toner transport member, and an opening and closing member for opening and closing a waste toner discharge port to the second housing.
The screw extending means extends the waste toner conveying member when the opening and closing member opens the discharge port, and extends the waste toner conveying member when the opening and closing member closes the discharge port. To release
The waste toner conveying device according to claim 1. The screw extension means includes a screw support member which supports the axial end of the waste toner conveyance member and is movable in the axial direction.
The opening and closing member rotates around an axis of the waste toner conveyance member to open and close the discharge port.
The screw extension means pushes the screw support member in the axial direction to extend the waste toner conveyance member when the opening and closing member is rotated to open the discharge port.
The waste toner conveying device according to claim 3. An elastic body is provided between the opening and closing member and a duct extending from the first housing and having the outlet formed therein, the elastic body biasing the opening and closing member in a direction closing the outlet.
The waste toner conveying device according to claim 3. The end portion of the waste toner conveying member opposite to the screw extending means is provided with a gear portion for rotating the waste toner conveying member.
The gear portion extends the waste toner conveyance member in a direction opposite to the direction of extension of the screw extension means when rotating.
The waste toner conveying device according to any one of claims 1 to 5. The gear portion extends the waste toner conveying member when rotating in the extended state.
The waste toner conveying device according to claim 6.   An image forming apparatus comprising the waste toner conveying device according to any one of claims 1 to 7.

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