JP4442134B2 - Waste toner conveying apparatus and image forming apparatus - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a toner conveying device that conveys waste toner to an image carrier using a metal spiral member, and an image forming apparatus having the toner conveying device.
[0002]
[Prior art]
The waste toner removed from the image carrier is transported to a discharge port by a toner transport screw arranged in the waste toner transport path (Patent Document 1). There are two types of screws in which plastic or metal is spirally wound. The metal-wrapped type has the following characteristics.
・ Since the waste toner can be uniformly transported to the discharge port little by little, clogging of the waste toner near the discharge port is unlikely to occur.
・ Because of its elasticity compared to plastic conveying screws, the shape of the waste toner conveying path and resistance from the surface are less likely to occur.
The metallic screw having such characteristics has problems of unstable posture and vibration. Therefore, conventionally, the problem of instability and vibration has been prevented by fixing both ends and rotating them.
[0003]
Conventionally, waste toner is transported using such characteristics. Regarding the transport of waste toner, it is not good that the waste toner remains in the transport path. In particular, if waste toner remains near the discharge port (on the side opposite to the screw drive side), there are the following problems.
・ Clogging near the discharge port due to residual waste toner ・ Contamination due to waste toner behavior at the time of replacement of the waste toner bottle and cleaning in the cleaner. Also, the following problems can be considered near the drive side.
Since problems such as the waste toner leakage from the bearing portion due to drive vibration occur, it is necessary to minimize the amount of clearance between the screw and the side surface of the transport path and to reduce the residual toner in the transport path as much as possible.
[0004]
[Patent Document 1]
Japanese Patent Laid-Open No. 2001-228771
[Problems to be solved by the invention]
However, if the clearance amount is small, the screw may be rubbed strongly with the side surfaces at both ends of the conveying path, which causes abnormal noise. The following two factors can be cited as the cause of strong rubbing.
・ Eccentricity of the screw in the nozzle (the cap part of the screw extending outward from the cleaner case) ・ The central axis of the screw in the slack nozzle generated by the friction between the screw and the side of the conveying path due to the eccentricity, and the center position of the screw by the bearing is Decided without room. For this reason, when the eccentricity in the nozzle occurs due to the rotation, the pressure generated by the eccentricity is applied to the side surface of the conveyance path, and an abnormal sound is generated by rubbing. Further, the slack of the screw due to the eccentricity rubs against the side surface of the conveyance path and an abnormal sound is generated. Since the screw is originally eccentric, when using a metal screw, it is necessary to take some measures against the factor of eccentricity.
[0006]
[Means for Solving the Problems]
An object of the present invention is to solve the above-described problems, and an object thereof is to prevent the generation of abnormal noise due to eccentricity of a screw and the generation of abnormal noise due to slack due to frictional force generated by the eccentricity.
To this end, the present invention provides a waste toner conveying device including a metal screw that is disposed in a waste toner accommodating portion and conveys waste toner, and a screw-side coupling member that is coupled to one end of the screw of the coupling pair is provided. The screw is loosely fitted to one end of a shaft provided in the screw and is movable in the axial direction with respect to the shaft .
[0007]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below.
FIG. 1 is a diagram illustrating an example of an image forming apparatus according to the present embodiment.
The photoreceptor 2 is uniformly charged by a charger (not shown), and an electrostatic latent image is formed by image exposure from the exposure device 5. A rotary developing unit 3 for developing toner on an electrostatic latent image has developing units of four colors Y, M, C, and K, and the developing roller 4 of each unit is positioned on the photosensitive member by intermittent rotation of the rotary developing unit. In this position, toner development is performed facing the photosensitive member 2 at that position. An intermediate transfer medium 1 stretched by a driving roller 6, a driven roller 7, a tension roller 8, a primary transfer roller 9 and the like is brought into contact with and separated from the photosensitive member 2 at the position of the primary transfer roller 9, and is placed on the photosensitive member. The formed toner image is transferred to the intermediate transfer medium 1 (primary transfer), and four colors are superimposed on the intermediate transfer medium.
[0008]
A secondary transfer roller 25 is provided at a position facing the drive roller 6 (also serving as a secondary transfer backup roller). The secondary transfer roller 25 is separated from and brought into contact with the intermediate transfer medium 1 by a separation / contact mechanism 24. The four color toner images are collectively transferred (secondary transfer). That is, the paper fed from the paper tray 21 by the paper feed roller 22 is conveyed to the position of the secondary transfer roller 25 through the paper conveyance path 23. While the color transfer is being performed on the intermediate transfer medium (during the primary transfer), the secondary transfer roller 25 is separated from the intermediate transfer medium. When applied, a four-color toner image is collectively transferred from the intermediate transfer medium to the paper (secondary transfer). The sheet after the secondary transfer passes through a paper guide 26 and is introduced into a fixing device 27 including a heating roller 27a and a pressure roller 27b, and is discharged to a discharge tray 28 on the upper surface of the apparatus.
[0009]
The cleaning blade 10 that comes in contact with the intermediate transfer medium 1 using the driven roller 7 as a backup roller comes into contact with the intermediate transfer medium 1 by the separation contact mechanism 11 and comes into contact with the toner after the secondary transfer, thereby remaining toner on the intermediate transfer medium 1. Remove. The cleaning member is not limited to the cleaning blade, and can be applied to any member such as a brush, a roller, and a sheet.
[0010]
FIG. 2 is a view for explaining the cleaning device of this embodiment.
The cleaning device 10 is provided at the position of the backup roller 7 so as to face the intermediate transfer medium 1, and a screw 12 made of a spiral member such as a metal spring is disposed in the cleaner case 11. Further, a cleaning blade 14 that is attached to the cleaner case 11 and can be brought into and out of contact with the intermediate transfer medium 1 by a blade fulcrum shaft 13 and an upper sheet 16 that can be brought into and out of contact with the intermediate transfer medium 1 by an upper sheet fulcrum shaft 15 are provided. It has been.
[0011]
After the secondary transfer, the toner remaining on the intermediate transfer medium 1 is scraped off by the cleaning blade 14 and accommodated in the cleaner case 11, transported by the screw 12, and transferred from the cleaner case 11 to a waste toner bottle (not shown). However, abnormal noise is generated by rubbing with the side of the transport path in the nozzle due to the eccentricity of the screw 12 and rubbing with the side of the transport path in the cleaner case 11 due to slack of the screw. Therefore, in the present embodiment, a configuration is adopted in which the generation of abnormal noise is prevented by devising a support method for both ends of the screw.
[0012]
FIG. 3 is a diagram showing an example of preventing abnormal sound generation according to this embodiment.
A metal screw 12 is disposed in the conveyance path 17 at the bottom of the cleaner case 11 that is a toner storage unit. One end of the screw is connected to a screw drive gear 31 through a coupling 30. In the coupling 30, a coupling member 30 a coupled to the drive gear side and a coupling member 30 b coupled to the screw side are engaged with each other with a margin in the axial direction and the radial direction. The outer coupling member 30a is a ring-shaped seal 3 2 for preventing the waste toner from leaking is provided.
[0013]
The screw 12 is provided with a central shaft 18 for determining the overall length and facilitating positioning on the coupling side when the screw is inserted / removed. Thus, the coupling member 30 b is movable in the axial direction with respect to the central axis 18.
[0014]
On the screw discharge port side, a nozzle 35 is provided on the side surface of the cleaner case 11, and the screw 12 extends from the cleaner case into the nozzle 35, and its end is attached to a mounting shaft 36. The mounting shaft 36 is rotatably supported by a bearing 37 of the nozzle 35. A ring-shaped seal 32 for preventing waste toner leakage is also provided outside the mounting shaft 36. Further, a discharge port 38 for discharging the waste toner conveyed from the cleaner case into the nozzle is formed on the bottom surface of the nozzle 35.
[0015]
4 is a diagram for explaining the state of eccentricity on the screw discharge port side, FIG. 5 is a diagram for explaining a method for preventing abnormal noise generation on the screw discharge port side, and FIG. 6 is a diagram for explaining a method for preventing abnormal noise generation on the drive side. It is.
When the screw in the nozzle is eccentric, if there is no allowance in the center position of the screw due to the mounting shaft 36 and the bearing 37, as shown in FIG. 4, the portions P1, P2, where the screw is strongly pressed against the side of the conveyance path in the nozzle, P3 and the like are generated, and this portion is rubbed strongly, so that an abnormal noise is generated, and the frictional force generated in the P1, P2, and P3 portions causes slack in the screw. Abnormal noise is generated by rubbing the sides.
[0016]
Therefore, as shown in FIG. 5, a backlash 39 is provided between the mounting shaft 36 and the bearing 37 in the nozzle so as to release the pressure in the radial direction.
Further, as shown in FIG. 6, the coupling member 30b to which the screw end on the driving side is connected has a margin in the axial direction with respect to the coupling member 30a, thereby absorbing sagging. Further, by making the diameter of the coupling member 30b movable in the axial direction with respect to the coupling member 30a smaller than the diameter D of the insertion hole of the coupling member 30a, a radial margin can be made, and the sag is absorbed similarly. Is done. In this way, the radial pressure in the nozzle due to the eccentricity of the screw and the slack of the screw are absorbed, and the generation of abnormal noise is prevented.
[0017]
【The invention's effect】
According to the present invention, an allowance is provided for the inner diameter of the bearing in the nozzle, thereby creating a relief area for the radial pressure generated by the eccentricity. As a result, the pressure on the side surface of the transport path can be reduced. In addition, the screw is fixed in a coupling type, and the slack generated by the frictional force is absorbed in the axial direction by providing a margin in the axial direction and the radial direction. As a result, the contact pressure on the side surface of the waste toner conveyance path due to the eccentricity of the screw is reduced, and the slack can be absorbed in the axial direction and the radial direction by the coupling type, so that abnormal noise can be eliminated.
[Brief description of the drawings]
FIG. 1 is a diagram illustrating an example of an image forming apparatus according to an exemplary embodiment.
FIG. 2 is a diagram illustrating a cleaning device of the present embodiment.
FIG. 3 is a diagram illustrating an example of preventing abnormal sound generation according to the present embodiment.
FIG. 4 is a diagram for explaining a state of eccentricity on the screw discharge port side.
FIG. 5 is a diagram for explaining the prevention of abnormal noise on the screw discharge port side.
FIG. 6 is a diagram for explaining the prevention of abnormal noise generation on the drive side.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 11 ... Cleaner case, 12 ... Screw, 18 ... Center shaft, 30 ... Coupling, 31 ... Screw drive gear, 36 ... Mounting shaft, 37 ... Bearing

Claims (7)

Disposed in the waste toner containing portion, a spiral screw in metal for conveying the waste toner, and the screw within the screw and shaft are provided separately, the waste toner conveying device Ru provided with,
A screw-side coupling member for coupling one end portion of the screw, the drive-side coupling member for engagement with the screw-side coupling member, further wherein the screw-side coupling member, one end portion of the front SL shaft waste toner conveying device, characterized in that the axially movable relative to the loosely fitted to the shaft. Waste toner conveying device according to claim 1, wherein the screw-side coupling member, characterized in that engage a margin with respect to the axial direction and the radial direction of the driving-side coupling member.   3. The waste toner conveying device according to claim 1, wherein a seal member is provided in the waste toner storage portion and outside the driving side coupling member. 4. An attachment member for attaching the other end of the screw is disposed at the other end of the shaft,
The shaft portion of the mounting member is supported so as to be pivotable through a bearing hole having an inner diameter larger than the outer diameter of the shaft portion. Waste toner transport device. The bearing hole is formed at an end of a nozzle provided on a side surface of the waste toner container;
The waste toner conveying device according to claim 4, wherein a seal member is provided outside the attachment member.   The waste toner conveying device according to claim 5, wherein a discharge port is formed in a bottom surface of the nozzle.   An image forming apparatus comprising the waste toner conveying device according to claim 1.

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