JPH045680A - Residual toner collecting device - Google Patents

Abstract

PURPOSE:To surely carry residual toner by making the flexural rigidity of a planar member positioned in a cleaning device larger than that of an intercepting member in a toner collecting box. CONSTITUTION:When the residual toner in the toner collecting box 31 gets equal to or above a specified quantity, a float member 49 follows the level of the toner and rises with the intercepting member 51. When the member 51 rises in a projection part 53 and attains a certain height, it intercepts an optical path which is emitted from a light emitting element 57, transmitted through the projection part 53 and reaches a light receiving element 59. By detecting this interception, that the box 31 is full of the residual toner is detected. The planar member 34 is provided on a partition 32 which divides the box 31 so as to perform an action for scraping the toner and an action for preventing the toner accumulated in the box 31 from returning in the cleaning device 30. By making the flexural rigidity of the coil spring-like spiral body of the device 30 larger than that of a toner carrying auger 35 in a U-shaped pipe, the residual toner is surely carried.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a residual toner recovery device for an image forming apparatus such as an electronic copying machine that uses toner to develop an electrostatic latent image. The present invention relates to a device that reliably collects residual toner collected from a latent image carrier.

[Conventional technology]

Conventionally, an electrostatic latent image formed on a photoreceptor such as a drum is developed with toner in a one-component or two-component developer, and after the developed toner image is transferred, the toner remaining on the photoreceptor is removed. The most common method was to collect residual toner from the photoconductor using a brush, blade, etc. of a cleaning device and store it in a residual toner collection bin attached to the cleaning device. This residual toner collection bin is replaced after it is full of toner, or after a predetermined number of copies have been made regardless of whether it is full of toner or not.

By the way, recently, a latent image carrier such as a photosensitive drum, a developing device, a cleaning device, etc. have been integrated into a replaceable unit.
Copying machines in which the unit is replaced with a new one after making a predetermined number of copies are becoming popular. In such units, residual toner is stored in a toner collection box attached to a cleaning device or in a space within a drum.

However, in the above-mentioned unit, if the number of copies to be replaced is 100,000 or more, the amount of residual toner collected will be considerable, and the toner collection box attached to the above-mentioned cleaning device will have to be collected. In this method, the size of the toner collection box must be made excessively large. however,
Integrating a latent image carrier such as a photosensitive drum, a developing device, a cleaning device, etc. into a replaceable unit requires handling 1.
In addition to facilitating service, the main objective is to make the copying apparatus itself smaller and more compact, so the size of the toner collection box cannot be increased too much. On the other hand, in the method of storing in the space inside the drum, the inner diameter of the drum is from several centimeters to at most 10 centimeters or less in order to make the entire device compact. It is not possible to accommodate all the residual toner of the copy. Further, the image densities of original documents used by users of copying machines vary, and when a document with high image density is copied, the amount of collected toner inevitably increases. On the other hand, normally sheet-like originals are copied with the original holding plate closed, but when copying thick originals such as books, copies are often made with the original holding plate open. In this case, the amount of toner collected per normal copy is five to ten times greater.

Therefore, it is possible to collect and store the residual toner in both the toner collection box attached to the cleaning device and the space inside the drum, but the problem is how to properly store the residual toner in both. .

In view of this situation, the applicant decided on December 2, 1999.
In a patent application titled "Residual Toner Collection Device" dated 7th, in a photoconductor unit configured by integrating at least a photoconductor drum and a cleaning device, a residual toner collection box is provided adjacent to the cleaning device, and The structure is configured so that the residual toner can also be stored in the space inside the photosensitive drum, and a means is provided for transporting the residual toner collected by the cleaning device to the residual toner collection box, and the residual toner collection box and the space inside the photosensitive drum are are connected by a U-shaped pipe and a coil spring-like helical body (auger) which is passed through the U-shaped pipe and rotates to convey the residual toner in the axial direction, and the coil spring-like helical body and means for rotationally driving the auger are connected. By interposing a torque limiter mechanism that cuts the connection when a torque exceeding a predetermined value is applied between the two, the space between the toner collection box installed adjacent to the cleaning device and the photosensitive drum can be reduced. We have proposed a residual toner collection device that self-contained, automatically, and reliably collects, fills, and stores residual toner collected from a photosensitive drum by a cleaning device. Then, the arrangement position of the coil spring-like spiral body in the residual toner collection box is selected from various locations, and various means for detecting that the space inside the photosensitive drum and the residual toner collection box are full of residual toner are provided. Proposed.

[Problem to be solved by the invention]

By the way, in the above-mentioned residual toner collecting device, if the toner conveying auger does not have sufficient rigidity, and the space inside the photosensitive drum is full of residual toner, the torque IJ will increase.
Before the Mitsuter mechanism operates, the tip is pushed back, deforms inside the toner collection box, and starts dancing wildly), damaging the cleaning brush, photoconductor 1, residual toner collection device, fullness detection means, etc. located in the vicinity. This may cause the fullness detection means to malfunction, and may cause residual toner to spill from the cleaning device.

Moreover, when the toner transport auger starts dancing like this,
It forms a loop inside the cleaner housing and continues to rotate in that shape. In this state, the torque limiter mechanism detects not the rotational load on the auger caused by the toner collected in the drum that is originally intended to be detected, but the load that forces the auger into a loop. In order to prevent such movement of the toner transport auger and ensure reliable operation of the torque limiter mechanism, it is possible to provide rigidity to the auger, but in this case, the toner collection box is connected to the space inside the photosensitive drum. The portion of the auger located inside the U-shaped pipe is frequently subjected to alternating tensile stress and compressive stress as it rotates, making it susceptible to breakage.

Therefore, the present invention solves the above-mentioned problems of the toner conveying auger in a residual toner collecting device configured to accommodate residual toner in the space inside the photosensitive drum.
Prevents the auger for transporting residual toner from dancing and also prevents the part located inside the U-shaped pipe from bending, ensuring that residual toner is transported from the cleaning device or residual toner collection box to the space inside the photosensitive drum. The torque limiter mechanism is operated to ensure that the residual toner collection light is switched from the interior space of the photosensitive drum to the residual toner collection box. An object of the present invention is to provide a residual toner collection device that prevents malfunction of a fullness detection means caused by uneven distribution of toner.

Furthermore, the present invention provides a residual toner collecting device configured to store residual toner in a space within a photosensitive drum, which reliably pushes and fills the collected residual toner into the space within the photosensitive drum. Another purpose is to provide.

[Means to solve the problem]

The present invention has been made to achieve the above object, and a residual toner collecting device of the present invention collects residual toner collected by a cleaning device of an image forming apparatus that uses toner to develop an electrostatic latent image. A residual toner collection device for transporting to a space inside a photosensitive drum, the cleaning device or a container attached thereto and a space inside the photosensitive drum,
Connected by a U-shaped pipe and a coil spring-like spiral body that is passed through the U-shaped pipe and conveys residual toner in the axial direction by rotational drive, and between the coil spring-like spiral body and a means for rotationally driving the same. In a residual toner collection device that is equipped with a torque limiter mechanism that disconnects the connection when a torque exceeding a predetermined value is applied between the two, the bending rigidity of the helical body like a coil spring located in the cleaning device or the container attached thereto. It is characterized in that the bending rigidity is larger than the bending rigidity of the coil spring-like helical body located within the U-shaped pipe.

In this case, the winding pitch of the coil spring-like spiral body located in the cleaning device or the container attached thereto is p1.
, the width of the wire is b1, the thickness of the wire is t1, the outer diameter is d, the winding pitch of the coil spring-like helix located in the U-shaped pipe is p2, the width of the wire is b2, and the thickness of the wire is When t7 is the outer diameter and d2 is the outer diameter, p+ >p2, b+ >b2.1. >1. ,d,<a,
, pl ・b+ −t+ /(1+>p2 ・b, ・t 2 / d 2 ) By configuring the coil spring-like spiral body to satisfy one or more of the following conditions, the cleaning device or the container attached thereto can be cleaned. The bending rigidity of the coil spring-like helix located inside the U-shaped pipe can be made greater than the bending rigidity of the coil spring-like helix located inside the U-shaped pipe.

Furthermore, the bending rigidity can be similarly increased by passing a thin rod in the axial direction of any part of the inner diameter of the coil spring-like helical body located in the cleaning device or the container attached thereto and fixing it together.

Another residual toner collection device of the present invention is a residual toner collection device that conveys residual toner collected by a cleaning device of an image forming apparatus that uses toner to develop an electrostatic latent image to a space inside a photosensitive drum. In a residual toner collection device in which a cleaning device or a container attached thereto and a space inside the photosensitive drum are connected by a thread conveying means for conveying the residual toner, a side plate partitioning one end of the photosensitive drum or a side plate thereof is rotatably supported. This device is characterized in that one end of a spiral body like a coil spring is fixed to the means, and the other end is arranged on the other end side of the photosensitive drum.

[Effect]

According to the first residual toner recovery device of the present invention, the bending rigidity of the coil spring-like spiral body located within the cleaning device or the container attached thereto is greater than the bending rigidity of the coil spring-like spiral body located within the U-shaped pipe. Because of this configuration, before the torque limiter mechanism operates, the coil spring-like spiral body is subjected to a load and deforms and becomes violent inside the cleaning device or toner collection box, causing the cleaning brush, photoreceptor 1, and residual toner collection located in the vicinity to be damaged. It will not damage or destroy the device, the fullness detection means, etc., and will not cause the fullness detection means to malfunction.

Further, residual toner does not spill from the cleaning device or the like.

Further, according to the second residual toner collecting device of the present invention, one end of the coil spring-like spiral body is fixed to a side plate partitioning one end of the photosensitive drum or a means for rotatably supporting the side plate,
Since the other end is disposed on the other end side of the photosensitive drum, the collected residual toner can be reliably pushed and filled into the space within the photosensitive drum.

〔Example〕

The present invention will now be described by way of example with reference to the accompanying drawings.

The overall configuration of one example of a copying machine using the residual toner collection device of the present invention is, in addition to an exposure device fixed to the device, a photoconductor unit including a photoconductor drum, a cleaning device, and a charging device, a developer unit, and a transfer device unit. , a fuser unit, and a paper tray, and each of these units is configured to be able to be pulled out independently toward the front of the device, so that each unit can be removed from the device for maintenance such as paper jams, cleaning, etc. It has become. and,
The photosensitive unit is configured to be replaced with a new one every 100,000 copies, for example.

During 100,000 copies, the residual toner collected from the photoconductor drum by the cleaning device is automatically collected and contained in the photoconductor unit, ensuring that the user is exposed to the residual toner collected in the photoconductor unit. Never.

FIG. 1 shows a cross section taken perpendicular to the rotation axis of the photosensitive drum of the photosensitive unit y) 1, and FIG. 2 shows the line n-n' in FIG. 1.
A cross section taken about is shown. In the figure, photosensitive drum 3
Die-cast cylindrical side plates 5 and 7 are fitted at both ends of the drum, and a space partitioned by the photosensitive drum 3 and the side plates 5 and 7 constitutes a first container 4 for storing residual toner. A rotating shaft 9 is integrally provided at the center of the side plate 7 of the photosensitive drum 3 on the back side of the apparatus, and is rotatably attached to the housing 11 of the photosensitive unit 1 via a bearing. A circular opening is provided at the center of the front side plate 5, and is rotatably fitted into a cylindrical portion 13 protruding from the housing 11 to the inside of the unit via a bearing. In addition, a gear 15 is cut on the outer periphery of the side plate 7 on the back side, so that the unit 1 can be pushed into the main body of the device from the front.
When this occurs, the drum rotation drive gear (not shown) on the device body side
It is designed to mesh with the Note that the device body has a positioning hole (not shown) into which the tip of the rotating shaft 9 protruding outward from the housing 11 is fitted, and a shaft (not shown) into which the tip of the rotating shaft 9 that projects outward from the housing 11 is fitted into the positioning hole 16 provided in the housing 11 of the unit 1.
(not shown), which constitutes a positioning mechanism when the unit 1 is pushed into the apparatus main body and set.

An IJ cleaning brush 17 is rotatably attached via a bearing between the extended side walls of the housing 11 provided at both ends of the photosensitive drum 3.
By rotating in contact with the photosensitive drum 3, the toner remaining on the drum 3 without being transferred by the transfer device is swept away. A gear 21 is fixed to the rear end (on the rear side of the apparatus) of the rotating shaft 19 of the cleaning brush 17, and meshes with a gear 29 for rotationally driving a toner conveying rotary paddle 27, which will be described later. Further, downstream of the point of contact between the photosensitive drum 3 and the cleaning brush 17, an elastic cleaning blade 23 is provided such that one side is fixed to the nozzing 11 and the other side contacts the drum 3 at an acute angle with respect to its rotating direction. The toner left behind by the cleaning brush 17 is scraped off from the photosensitive drum 3.

Further, a scraping member 22 for scraping off toner adhering to the cleaning brush 17 downward is attached to a partition wall 32, which will be described later, and its tip is in contact with the cleaning brush 17. Further, in order to convey the residual toner scraped off onto the bottom plate 25 of the housing 11 by the cleaning brush 17 and the cleaning blade 23 in a direction away from the cleaning device 30, a no.
A toner conveying rotary paddle 27 is rotatably provided on the rear side of the cleaning brush 17 in the housing 11 (on the side far from the drum 3) and parallel to the cleaning brush 17 via a bearing. A gear 29 is fixed to the shaft diameter end of the rotary paddle 27 and meshes with a gear 21 for rotating the cleaning brush 17, so that the rotary paddle 27 and the cleaning brush 17 rotate in the direction of the arrow shown. By the way, the housing 11 is
A toner collection box 31, which is a second container for storing residual toner, is formed on the rear side of the cleaning device 30, which is composed of a cleaning brush 17, a cleaning blade 23, and a toner transport rotating paddle 27. The box 31 is partially separated by a partition wall 32.

An elastic plate member 34 is provided with one end fixed to the partition wall 32 and extending downward, and its lower end is connected to the rotary paddle 2.
It is in elastic contact with the plane of 7. The rotary paddle 27 has a regular polygonal cross section as shown in the figure, and by rotating in the direction of the arrow shown in the figure, serves to scrape out residual toner accumulated on the rear side of the cleaning brush 17 into the toner collection box 31. .

A plate member 34 whose tip is in elastic contact with this polygonal cross-sectional surface
has the function of scraping off the toner adhering to the surface, and the function of preventing the toner from accumulating in the toner collection box 31 and returning into the cleaning device 30 again.

Rear housing 11 near the bottom of toner collection box 31
A rotary shaft 33 is rotatably provided on the toner collection box 31 side, as described later.
An elastic toner conveying auger 35, which is formed by forming a J-shaped plate member into a helical shape (spiral shape) with the normal line of its surface facing the axial direction of the cylinder, is coaxially fixed. Further, a gear 37 for rotating the auger is attached to the rear end of the rotating shaft 33 via a torque IJ mittator mechanism 38 (described later) that is disconnected when a predetermined torque or more is applied. The toner transport auger 35 extends along the bottom of the toner collection box 31 in parallel with the toner transport rotary paddle 27 and the like, and its tip has a length that projects through a circular opening 39 provided in the front wall of the housing 11. ing. A U-shaped pipe 43 having an inner diameter slightly larger than the cross section of the toner conveying auger 35 is connected between the circular opening 39 and the hole 41 inside the bearing 3 in which the photosensitive drum 3 is rotatably supported by the housing 11. a toner transport auger 3 connected to the toner transport auger 3 and projecting through a circular opening 39;
5 is bent along this pipe 43, and its tip 45 protrudes into the space 4 inside the drum 3.

As mentioned above, the toner conveyance auger 35 has the shape of a flexible helical spring, and when it is rotated, it conveys the toner that has entered between its blades in the axial direction using the principle of a helical pump. It is something to do. Therefore, by rotating the toner collection box 31,
The residual toner at the bottom within the toner collection box 31 can be conveyed along the pipe 43 to the space 4 within the drum 3. In addition, a gear 37 for rotating the toner conveying auger 35
and a gear 29 for rotating the rotary paddle 27 are engaged with a drive gear 47 rotatably provided on the rear wall of the housing 11 . When set in the main body of the apparatus, it engages with a drive gear (not shown) provided on the main body to rotate the cleaning brush 17, the toner conveying rotary paddle 27, and the toner conveying auger 35.

The toner collection box 31 is provided with a float member 49 that floats up from below with the accumulated toner when the residual toner contained therein exceeds a predetermined amount. Opaque shielding member 5
1 is provided integrally. When the float member 49 levitates and rises above the housing 11,
A protrusion 53 made of a transparent wall is provided that forms a space into which the shielding member 51 enters from below.

On the other hand, the main body of the apparatus is provided with a groove 55 into which the protrusion 53 enters when the photoreceptor unit 1 is set.
A light emitting element 57 and a light receiving element 59 are provided facing each other on both sides. Therefore, when the residual toner in the toner collection box 31 reaches a predetermined amount or more, the float member 49 rises to follow the surface thereof, and the shielding member 51 also rises together.

This shielding member 51 rises within the protrusion 53 and, when it reaches a certain height, blocks the optical path that exits the light emitting element 57, passes through the protrusion 53, and reaches the light receiving element 59. Therefore, by detecting this interruption, it is possible to detect that the toner collection box 31 is full of collected residual toner. This full detection mechanism 6
Regarding the details of 0, the present applicant previously filed a U.
Please refer to Japanese Utility Model Application Publication No. 63-39259, which has been filed as No. 2700.

It should be noted that the fullness detection mechanism 60 is not limited to the one described above, and it is obvious that various types of known types can be used.

In FIG. 1, the photosensitive unit 1 is integrally provided with a charger 61 downstream of the cleaning blade 23 for uniformly charging the photosensitive drum after cleaning for forming a latent image.

To explain the operation of the residual toner collecting device according to one embodiment of the present invention having such a configuration, the photosensitive drum 3, which is uniformly charged by the charger 61, undergoes image exposure in an exposure section (not shown). An electrostatic latent image is formed on the surface of the photosensitive drum 3. Next, in a developing device (not shown), toner charged to the opposite polarity to that of the electrostatic latent image is applied to the photosensitive drum 3.
A toner image is formed by contacting the surface. This toner image is brought into contact with a sheet of paper conveyed at a speed equal to the circumferential speed of the photosensitive drum 3 in a transfer device (not shown) provided at the next position, and is transferred onto this sheet of paper. The paper onto which the toner image has been transferred is conveyed to a fixing device, the toner image is fixed on the paper, and the paper is discharged from the apparatus. On the other hand, the photosensitive drum 3 reaches the cleaning device 30, and the toner remaining on its surface without being transferred by the transfer device is scraped off onto the bottom plate 25 of the housing 11 by the cleaning brush 17 and the cleaning blade 23.

The residual toner accumulated at this position is transferred to a toner collection box 30 provided adjacent to the cleaning device 30 by the toner transport rotary paddle 27 rotating at this position.
being pushed inside. The residual toner scraped out into the toner collection box 31 is placed near the bottom of the toner collection box 31, preferably near the toner transport rotating paddle 27 (however, this requirement is not necessarily required). As the toner transport auger 35 rotates, the toner is transported to the space 4 inside the photosensitive drum 3 via the pipe 43 . Note that even within the pipe 43, the toner conveying auger 35 can rotate around the axis while being bent due to its elasticity to convey the residual toner in the axial direction. During this time, the residual toner scraped into the toner collection box 31 is sequentially transported to the space 4 within the photosensitive drum 3 by the toner transport auger 35, so that the residual toner does not accumulate within the toner collection box 31. When the space 4 inside the photosensitive drum 3 becomes filled with residual toner, a large resistance begins to be applied to the toner transport auger 35. When this resistance exceeds a predetermined level, the torque limiter mechanism 38 provided between the rotating shaft 33 of the toner conveying auger 35 and the gear 37 for rotating the auger operates, and the toner conveying auger 35 rotates. The residual toner is no longer conveyed to the space 4 within the photosensitive drum 3. Therefore, the toner transport rotating paddle 2
The residual toner scraped out by 7 begins to accumulate in the toner collection box 31. When the residual toner contained therein reaches a predetermined amount or more, the float member 49 rises to follow the surface thereof, and the shielding member 51 also rises together. This shielding member 51 rises within the protrusion 53,
When a certain height is reached, the light path that comes out from the light emitting element 57, passes through the protrusion 53, and reaches the light receiving element 59 is blocked, and as a result, the toner collection box 31 becomes full with the collected residual toner. It is possible to detect that something has happened. The copying device may be stopped by this signal, but at the position where the shielding member 51 first blocks the optical path from the light emitting element 57 to the light receiving element 59, a predetermined amount of residual toner is further stored in the toner collection box 31. This signal is used as a warning signal to warn that the space 4 inside the photosensitive drum 3 and the toner collection box 31 will be full of collected residual toner after a predetermined number of copies have been made. You can also do this.

Next, a torque limiter mechanism 38 is provided between the rear end of the rotating shaft 33 of the toner conveying auger 35 and the gear 37 for rotating the auger, and breaks the connection when a torque exceeding a predetermined value is applied between the two. An example of this will be explained with reference to FIG. The auger rotation gear 37 is coaxially and rotatably fitted into the rotating shaft 33. A cylindrical hole 63 is coaxially formed in one end of the auger rotation gear 37, and a cylindrical portion 65 protrudes from the bottom with an outer diameter smaller than the inner diameter of the cylindrical hole 63 and shorter than the depth of the cylindrical hole 63. ing.

A coil spring 67 longer than the cylindrical portion 65 is wound around the cylindrical portion 65, and one end 69 of the coil spring 67 is wound around the cylindrical portion 65.
is fixed to the bottom of the cylindrical hole 63. A cylindrical body 71 coaxially fixed to the rotating shaft 33 is press-fitted into the inside of the coil spring 67 that protrudes from the cylindrical portion 65 . Since the outer diameter of the cylindrical body 71 is configured to be slightly larger than the inner diameter of the coil spring 67, when a rotational force is applied to the gear 37 with a torque below a predetermined value in the direction of loosening the winding of the coil spring,
This rotational force is transmitted to the rotating shaft 33 by the frictional engagement between the coil spring 67 and the cylindrical body 71. On the other hand, if strong resistance (load) is applied to the toner transport auger 35, which has one end fixed to the rotating shaft 33, for example, the drive gear 4
Even if a rotational force is applied to the gear 37 from the coil bar 267, the winding of the coil bar 267 loosens and the frictional engagement between the coil bar 267 and the cylindrical body 71 loosens, so the gear 37 simply rotates idly, and the rotating shaft 3
3, the rotational force is no longer transmitted.

That is, since the rotational force is transmitted from the gear 37 to the toner conveying auger 35 through the mechanism 38 known as a slip torque limiter, a resistance (load) exceeding a predetermined value is applied to the toner conveying auger 35. If this occurs, the toner transport auger 35 is stroked so that it no longer rotates. Note that by adjusting the size of the inner diameter of the coil spring 67 with respect to the outer diameter of the cylindrical body 71, the magnitude of the limit torque can be adjusted.

As the torque limiter mechanism 38, various mechanisms other than the one described above can be used, and a mechanism as shown in FIG. 4 can also be used. To explain this, a modified gear 370 is used in place of the auger rotation gear 37 in FIGS. 1 and 2.

This gear 370 has a thin gear portion 37 that occupies most of the circumference.
2 and a thick gear portion 371 that occupies a part of the circumference and protrudes in the direction of the auger 35.

Separately from these gear parts 371 and 372, there is an engaging part 373 that is coaxial with these gear parts and has an outer diameter smaller than these outer diameters. This engaging portion 373 is arranged in the auger 3 in the axial direction.
A peak 375 protruding in five directions, a valley 374 recessed from this, and a slope 3 with a predetermined slope connecting these
76.

The difference in height in the axial direction between the peak portion 375 and the valley portion 374 is β
It is 1. This gear 370 is connected to the rotating shaft 33
A compressible spring 7 is fitted coaxially and rotatably into the
3 in the direction of the auger 35. On the other hand, an engaging body 710 is coaxially fixed to the rotating shaft 33. The engaging portion 37 of the engaging body 710 is located on the gear 370 side.
It has a conjugate surface on the front surface of 3. That is, the engaging portion 3
73 corresponding to the troughs 374 and the engaging portion 37
The valley portion 711 corresponding to the peak B575 of No. 3 and the engaging portion 373
The height difference in the axial direction between the peaks 712 and the valleys 711 is 11. Note that the slope portion 71 is located at the mountain portion 712.
A protruding portion 714 is provided that serves as a stopper to prevent the peak portion 375 of the engaging portion 373 that has climbed from the top 3 from returning again. In the normal state (shown in (a) of the figure), the deformable gear 370 presses into engagement with the engagement body 710 by the action of the expandable spring 73, and the engagement body 710 and the engagement portion 373 are pressed against each other. The conjugate surfaces fit into each other. In this state, the thin gear part 372 and the thick gear part 371 of the deformed gear 370 are meshed with the driving gear 47, and the meshing width between the thin gear part 372 and the driving gear 47 is 12, and the thick gear part 371 and the thick gear part 371 are meshed with each other. The meshing width of the driving gear 47 is β3. Between the height difference 1 and these widths p2 and β3, there is a relationship of C>L and β3>1. If the resistance (load) applied to the auger 35 increases in such a state, as shown in (b) of the figure,
The inclined portion 376 of the engaging portion 373 slides along the inclined portion 713 of the engaging body 710 against the action of the spring 73, and the deformation gear 370 begins to move away from the engaging body 710. However, the engagement between the thin gear portion 372 of the deformed gear 370 and the drive gear 47 is maintained. Therefore, the rotational force from the drive gear 47 is transmitted to the rotating shaft 33 through engagement between the inclined portion 376 and the inclined portion 713. Auger 35
When the resistance (load) applied to the engagement body 71 increases further, the inclined portion 376 of the engagement portion 373 moves toward the engagement body 71, as shown in (C) of the figure.
further slide along the slope 713 of 0. From the relationship β1>β2 described above, the slope portion 376 and the slope B713
Before the engagement of the drive gear 47 and the thin gear part 37
2 will be disengaged. At this time, as shown in Figure (C),
When the thick gear part 371 is not engaged with the driving gear 47, the thin gear part 372 and the driving gear 47 repeatedly engage and disengage, and deform until the thick gear part 371 engages with the driving gear 47. Gear 370 rotates. Thick gear part 37
1 engages with the drive gear 47, the above-mentioned As>j
! , as shown in (d) of the figure, the slope part 3
76 slides all at once on the inclined part 713, and the tip of the peak part 375 of the engaging part 373 of the deformable gear 370 touches the engaging body 71.
It overruns and crosses over the protruding part 714 of the peak B712 of 0, rides on the peak 712, and reaches a stable state (of course, the dimension 13 above takes into account the allowance for causing the Funi overrun in this way). ). At this time, the number of teeth of the thick gear part 371 has already been selected so that the engagement between the thick gear part 371 and the drive gear 47 is disengaged, so the engagement between the deformation gear 37 (l and the drive gear 47 is broken). There is.

And this state continues. Note that the engaging portion 3
The protruding portion 714 of the peak portion 712 of the engaging body 710 acts as a stopper, and the peak portion 375 of 73 is stroked so that it does not return to the valley portion 711 again. As described above, when the resistance of the residual toner accumulated in the drum space 4 is multiplied by the load torque multiplication mechanism described later and applied to the auger 35,
The rotational force of the drive gear 47 is not transmitted to the auger 35,
Therefore, conveyance of the residual toner from the toner collection box 31 to the space 4 within the drum 3 is stopped.

Note that the torque limiter mechanism 38 and the third
The difference between the mechanism 38 shown in the figure is that the mechanism 38 in Figure 3 restores the connection between the gear 37 and the auger 35 when the resistance acting on the auger 35 decreases, whereas the mechanism 38 in Figure 4 restores the connection between the gear 37 and the auger 35. This kind of recovery does not occur, and in the case of the one in Fig. 4, there is no engagement relationship between the gears, etc. when the connection between the two is broken, so there is no generation of frictional heat or noise, whereas in the case of the one in Fig. 3. The one in Figure 3 generates frictional heat and noise, and even if a large resistance is temporarily applied to the auger 35 for some reason, the auger can be rotated again once the resistance is gone. The problem with the one shown in Figure 4 is that even in such a case, the auger cannot be rotated again.

Although the torque limiter mechanism 38 exemplified above constitutes a mechanical detection mechanism for the torque applied to the toner transport auger 35, it may be constituted electrically.

That is, for example, the rotation shaft 33 of the toner conveying auger 35
A torque meter may be provided at the toner conveying auger 35, and the rotation of the toner conveying auger 35 may be stopped when the signal obtained from the torque meter exceeds a predetermined value.

Here, the results of a specific investigation of the relationship between the shaft torque of the toner transport auger 35 and the amount of residual toner collected will be shown.

Photosensitive drum 3 Drum inner diameter: φ84mm Effective length in the longitudinal direction of the drum: 320mm Toner used: Two-component non-magnetic toner auger 35 Outer diameter: φ10mm Inner diameter: φ6mm Thickness: 0.4mm Pitch: 5mm Rotation speed: 1100rp More configurations FIG. 5 shows the results of measuring the shaft torque of the auger drive shaft 33 while measuring the amount of toner collected in the drum. FIG. 5 is a plot of the average value, maximum value, and minimum value of the result of overlapping the toner recovery amount and the transition of the auger shaft torque at that time many times. When the auger shaft torque exceeds 500 gf-cm, toner can no longer be pushed into the drum (at this time, the drum is almost filled with recovered toner). On the other hand, the auger shaft torque is between 50gf-cm and 150gf-cm.
In the range of , the amount of toner collected in the drum varies considerably.

The reason for this is that the contact resistance between the auger 35 and the housing 25 and the contact resistance between the auger 35 and the pipe 43 vary, so that the residual toner may not be sufficiently transported. It can also be seen that as the auger shaft torque increases, the variation in collected toner within the drum becomes smaller. On the other hand, the shaft torque is 500g
When f-cm is exceeded, the drum is already full of recovered toner, so that no more toner can be pushed into the drum, and the tip of the auger begins to be pushed back into the pipe 43. As a result, the slackened auger 35 inside the housing 11 will come loose, damaging and destroying the cleaning brush, photoreceptor 1, residual toner collection device, fullness detection means, etc. located in the vicinity of the auger 35. This may cause toner to spill. 1 on average
Assuming that 10 mg of residual toner is collected from the drum per copy, if the number of copies is plotted on the vertical axis in Figure 5, the variation in the amount of toner collected in the drum will directly affect the variation in the number of copies that the photoconductor unit can use. It will become.

As demonstrated above, the toner agitation auger 35 is activated when the space 4 inside the photosensitive drum 3 becomes full with recovered residual toner and the torque applied to the auger 35 becomes larger than a predetermined value, or due to other circumstances. When the torque limiter mechanism 38 operates normally and the connection between the gear 37 and the rotating shaft 33 is not broken even though the torque applied to the auger 35 temporarily exceeds a predetermined value, toner recovery is performed. It deforms and rotates in a large spiral inside the box 31 and starts dancing wildly), damaging the IJ-ning brush 17, photoreceptor 3, toner conveying rotary paddle 27, full detection mechanism 60, etc. located nearby. The full detection mechanism 60
Otherwise, the residual toner in the toner collection box 31 is thrown up and put into the protrusion 53, causing the full detection mechanism 60 to malfunction. Furthermore, as a result of the toner being thrown loose inside the toner collection box 31, the collected residual toner may spill out of the housing 11. Such a toner conveying auger 3
In order to prevent the bending of 5, it is sufficient to increase the bending rigidity. FIG. 6 shows a side view of the toner conveying auger 35 having a uniform configuration in the axial direction. As mentioned earlier, the toner conveying auger 35 attached to the rotating shaft 33 is formed by winding a strip-like plate-like member into a spiral spring shape with the normal line of its surface facing the axial direction of the cylinder. and
When this is rotated around the shaft, toner that has entered between the blades from the periphery is transported forward in the axial direction through the central space by the principle of a spiral pump. The winding pitch of the auger is p, the width of the IJ tubular cotton wire is b,
S) The thickness of the IJ tubular cotton wire is t1 The outer diameter of the auger is d
Then, the bending rigidity M of the auger satisfies the following relationship.

Mζc -p -b -t / a ----(1
) (C is a proportionality constant) Now, as shown in Fig. 7, the bending rigidity M of the auger 35 is expressed as follows:
It is defined by the amount of downward displacement (amount of slack) Y when the auger is extended to 0 mm.For example, if the outer diameter d of the auger is 16 mm.
, the width of the wire is 2 mm, and the thickness t of the wire is 0.45.
When the deflection amount Y is examined using the winding pitch p of the auger as a variable in the case of 0.6 mm and 0.6 mm, the result is as shown in FIG. Note that the length of the auger 35's tip extending in the horizontal direction in a free state is defined as X, and the thickness of some wire rods is t.
FIG. 9 shows the results of examining the amount of deflection Y for the combinations of the winding pitch p of the auger and the winding pitch p of the auger. In the case of FIG. 8, when we investigated the occurrence of deflection of the auger portion A within the housing 11, we found that this occurred when an auger with a deflection of 30 mm or more was used as shown in the figure. therefore,
In order to prevent the toner transport auger 35 from dancing, the amount of deflection Y may be set to 30 mm or less. In this way, in order to increase the bending rigidity for the purpose of preventing the toner conveying auger 35 from dancing, the width of the wound pitchle 1 strip-shaped wire material b, s) Either increase the wire thickness t or increase the auger diameter d.
All you have to do is make it smaller. However, if the rigidity of the toner transport auger 35 is uniformly increased, the toner collection box 3
1 and the space 4 inside the photosensitive drum 3.
Part B of the auger located inside is frequently subjected to alternating tensile stress and compressive stress as it rotates, making it more likely to break. When examining this in the example shown in Figure 8, this occurred with an auger whose deflection pot was 30 mm or less. As described above, the inside of the housing 11 and the U-shaped pipe 43
The requirements for the toner transport auger 35 are completely contradictory.

Therefore, in the present invention, the bending rigidity of the portion A located inside the toner collection box 31, which is a part where problems occur due to the movement of the toner transport auger 35, is relatively increased, and the inside of the U-shaped pipe 43, where there is no fear of movement, is increased. The bending rigidity of portion B located at is made relatively low in order to prevent it from collapsing. To do this, as is clear from the above formula [1), the winding pitch of part A is p1, the width of the +J tube-shaped edge wire is b1, the thickness of the strip-shaped wire is t1, the auger outer diameter is dl, When the winding pitch of part B is p2, the width of the IJ tube-like cotton wire is b2, the thickness of the strip-like wire is t2, and the outer diameter of the auger is d2, pl> p2 , bl > b2, t I> t 2 ,d
The structure may be configured to satisfy one or more of the following conditions: l < d, pl, bl, t, /d > p2, b2, t 2 / d 2. Specifically, any one of the parameters p, b, t, and d may be selected so as to satisfy the above conditions. For example, either the winding pitch of portion A or the width of the strip-like wire material, (i) + J-tube-like edge wire thickness, are made larger than the corresponding parameters of portion B. Or, change the auger diameter of part A to part B.
be smaller than the diameter of Furthermore, two or more parameters may be made different at the same time to satisfy the above conditions. As described above, instead of making the axial parameters of the toner transport auger 35 different between portions A and B, the first
As shown in FIG. 0, even if a thin round rod 63 of about 1 to 2 mm is passed in the axial direction of any part of the inner diameter of the part A located in the toner collection box 31 of the auger 35 and fixed together, As in the above case, the bending stiffness of the part increases. Furthermore, although the bending rigidity of the portion A is not increased, as shown in FIG.
It is also effective to hold the auger 35 in a rotatable manner with semicircular holding metal fittings 65 at 2.3 locations within the opening.

By the way, as described above, the bending rigidity of the toner transport auger 35 inside the toner collection box 31 is determined by the U-shaped pipe 4.
If the bending rigidity is larger than that in part B, the toner transport capacity to the part B will be larger than that in part B (for example,
This will be obvious if we consider the pitch p. ). therefore,
As shown by reference numeral 67 in FIG. 12, a portion of the residual toner conveyed by the toner conveying auger 35 in section A is not fully conveyed by the auger 35 in section B and accumulates near the pipe 43 of the toner collection box 31. It becomes a mountain. In addition, the recovered residual toner accumulated near the population of the space 4 inside the photosensitive drum 3 is transferred to the pipe 4 due to the pressure inside the space 4 (due to the inability of air to escape).
3, and this backflow toner is also added to this mountain 67. As the mountain of this unevenly distributed toner 67 increases, it may push up the float member 49 of the toner full detection mechanism 60, causing the full detection mechanism 60 to operate even though the toner collection box 31 is not full. . In order to prevent such malfunctions, the unevenly distributed toner 67 may be dispersed. From this point of view, the configuration shown in FIG. 6, that is, the auger 35
A structure in which a thin round rod 63 is passed through in the axial direction of any part of the inner diameter of the part A located in the toner collection box 31 of the toner collecting box 31 is suitable. With this configuration, the first
Since the round rod 63 constantly streaks the unevenly distributed toner pile 67 shown in FIG. 1 and disperses it to the surrounding area, the risk of pushing up the float member 49 and causing the fullness detection mechanism 60 to malfunction is reduced.

In this case, the position of the round rod 63 does not necessarily need to span the entire length of the toner collection box 31, and it is effective to arrange it, for example, only half the length of the toner collection box 31 near the pipe 43.

The residual toner conveyed to the internal space 4 of the photosensitive drum 3 through the pipe 43 by the toner conveying auger 35 as described above accumulates near the entrance and does not reach the depths of the space 4 easily. If you try to force it all the way in,
A strong torque must be applied to the toner conveying auger 35, and if the auger 35 is formed to withstand such strong torque, it will easily break within the U-shaped pipe 43.

Therefore, it is desirable to provide a mechanism separate from the toner transport auger 35 for transporting the incoming residual toner to the depths of the interior space 4 of the photosensitive drum 3. An example of such a mechanism is shown in FIGS. 13 and 14. In the example shown in FIG. 13, a large-diameter auger 69 is wound around and fixed to the cylindrical side plate 5 on the front side (inlet side) of the photosensitive drum 3. The other end of the auger 69 reaches deep into the interior space 4 of the photosensitive drum 3, and as the photosensitive drum 3 rotates, the auger 69 also rotates, so residual toner that has entered through the U-shaped pipe 43 is removed from the auger. 69, it is pushed deep into the space 4.

In the example shown in FIG. 14, a medium-diameter auger 73 is fixed to a bearing 71 that rotatably attaches the side plate 5 or a bearing 13 that protrudes from the housing 11 into the photoreceptor 3.
The other end is placed deep inside the photosensitive drum 3 interior space 4.

This auger 73 does not rotate even when the photosensitive drum 3 rotates, but as the photosensitive drum 3 rotates, the residual toner sent into it also rotates, so the auger 73 rotates relatively, and the depth of the space 4 is rotated. This will force the residual toner into the

In the embodiments shown in FIGS. 1 and 2, the toner conveying rotary paddle 27 is provided upstream of the toner conveying auger 35, but this toner conveying rotary paddle may be omitted as shown in FIG. . Even in such a case, the residual toner can be reliably accommodated in the space 4 within the photosensitive drum 3 by providing the toner conveying auger 35, the large diameter auger 69, and the medium diameter auger 73.

〔Effect of the invention〕

According to the first residual toner recovery device of the present invention, the bending rigidity of the coil spring-like spiral body located in the cleaning device or the container attached thereto is equal to the bending rigidity of the coil spring-like spiral body located in the U-shaped pipe. Since the structure is larger, before the torque limiter mechanism operates, the coil spring-like spiral body is subjected to a load and deforms and becomes violent inside the cleaning device or toner collection box, causing the cleaning brush, photoreceptor 1, and remaining particles located in the vicinity of the coil spring-like spiral body to deform and become violent. It will not damage or destroy the toner collection device, the fullness detection means, etc., and will not cause the fullness detection means to malfunction.

Further, residual toner does not spill from the cleaning device or the like.

Further, according to the second residual toner collecting device of the present invention, one end of the coil spring-like spiral body is fixed to a side plate partitioning one end of the photosensitive drum or a means for rotatably supporting the side plate,
Since the other end is disposed on the other end side of the photosensitive drum, the collected residual toner can be reliably pushed and filled into the space within the photosensitive drum.

[Brief explanation of drawings]

FIG. 1 is a sectional view taken perpendicular to the rotation axis of the photosensitive drum of a photosensitive unit 7) equipped with a residual toner recovery device using a toner conveying auger according to the present invention, and FIG. 2 is a cross-sectional view taken along the line n-- of FIG.
3 is a sectional view of one example of the torque IJ mittter mechanism used in the residual toner collection device of the present invention, and FIG. 4 is the structure of another torque IJ mittter mechanism. Figure 5 is a diagram showing the results of measuring the axial torque of the auger drive shaft without measuring the amount of toner collected inside the photosensitive drum, and Figure 6 is a diagram showing the results of measuring the axial torque of the auger drive shaft. Side view 1 of the toner conveying auger configured as shown in Fig. 7.
The figure is a diagram explaining one definition of the bending rigidity of the auger, Figure 8 is a diagram showing the results of investigating the amount of deflection using the winding pitch of the auger as a variable, and Figure 9 is the freedom of the auger tip in the horizontal direction. FIG. 10 is a side view of the toner conveying auger used in one embodiment of the present invention, and FIG. 11 is a diagram showing the results of examining the advancing length and the amount of deflection in the state. FIG. 11 is a side view of the toner conveying auger used in one embodiment of the present invention. Diagram of the Covenant Explaining the Means, Part 1
Figure 2 is a cross-sectional view taken along line ■-■' in Figure 1.
3 and 14 are diagrams for explaining a residual toner collection device according to another embodiment of the present invention, and FIG. 15 is similar to FIG. 1 of a photoreceptor unit equipped with another example of a residual toner collection device. FIG. 1... Photosensitive unit, 3... Photosensitive drum, 4...
・Space inside the photosensitive drum, 5.7... Cylindrical side plate, 9.
... Rotating shaft, 11... Housing, 13... Bearing protruding from the housing to the inside of the unit, 15...
There is a gear cut on the outer periphery of the side plate, 16... positioning hole,
17... Cleaning brush, 19... Rotating shaft of the cleaning brush, 21... Gear fixed to the rotating shaft of the cleaning brush, 22... Scraping member, 2
3...Cleaning blade, 25...Bottom plate of housing, 27...Toner conveyance rotating paddle, 29...Toner conveyance rotating paddle rotation drive gear, 3o...Cleaning device, 31...Toner collection box , 32...
Partition wall between cleaning device and toner collection box, 3
3... Rotating shaft, 34... Plate member, 35... Toner conveying auger, 37... Gear for auger rotation, 3
8...Torque limiter front, 39...Loop-shaped opening provided on the front wall of the housing, 41...Hole, 43...
・U-shaped pipe, 45...Tip of auger, 47...
- Driving gear rotatably provided on the rear wall of the housing, 49...Float member, 51...Shielding member, 53...Protrusion made of transparent wall, 55...Protrusion Groove to enter, 57... Light emitting element, 59... Light receiving element, 60... Full detection mechanism, 61... Charger, 63...
...Thin 1 round bar, 65...Semicircular presser metal fitting, 67.
...Pile of residual toner accumulated near the pipe population, 69.
...Large diameter auger, 71...Bearing, 73...
・Medium diameter auger, 370... Deformed gear, 371...
・Thick gear part, 372... Thin gear part, 373...
Engagement portion, 374... Valley portion, 375... Peak portion, 376
... Inclined part, 710... Engaging body, 711... Valley part, 712... Mountain part, 713... Inclined part, 714...
- Branching part, A...The part located inside the toner collection box 31 of the toner transport auger, B...The part located within the V-shaped knob of the toner transport auger, Applicant: Fuji Serotox Co., Ltd. Agent Person Patent attorney Hiroshi Nirasawa (7 others) Figure (b) Figure 9 Figure 7 Pitch P Figure 8

Claims (4)

[Claims] (1) A residual toner collection device that conveys residual toner collected by a cleaning device of an image forming apparatus that uses toner to develop an electrostatic latent image to a space within a photosensitive drum, and is attached to the cleaning device or attached thereto. The container and the space inside the photosensitive drum are connected by a U-shaped pipe and a coil spring-like spiral body that is passed through the U-shaped pipe and which conveys the residual toner in the axial direction by a rotational drive, and the coil spring-like spiral body and the spiral body are rotated. In a residual toner collection device that is provided with a torque limiter mechanism that disconnects the coupling between the coil spring and the driving means, the coil spring is located in the cleaning device or a container attached thereto. A residual toner collecting device characterized in that the bending rigidity of the coil spring-like spiral body is greater than the bending rigidity of the coil spring-like spiral body located within the U-shaped pipe. (2) The winding pitch of the coil spring-like spiral body located in the cleaning device or the container attached thereto is p_1,
The width of the wire is b_1, the thickness of the wire is t_1, and the outer diameter is d_1
When the winding pitch of the coil spring-like helix located in the U-shaped pipe is p_2, the width of the wire is b_2, the thickness of the wire is t_2, and the outer diameter is d_2, p_1>p_2, b_1>b_2, t_1>t_2, d
The residual coil according to claim 1, wherein the coil spring-like helical body is configured to satisfy one or more of the following conditions:_1<d_2, p_1・b_1・t_1/d_1 >p_2・b_2・t_2/d_2 Toner collection device. (3) The residual toner collecting device according to claim 1, wherein a rod is inserted in the axial direction of any part of the inner diameter of the coil spring-like helical body located in the cleaning device or a container attached thereto and fixed to the device. (4) A residual toner collection device that conveys residual toner collected by a cleaning device of an image forming apparatus that uses toner to develop an electrostatic latent image to a space inside a photosensitive drum, and is attached to the cleaning device or attached thereto. In a residual toner collection device in which a container and a space inside a photosensitive drum are connected by a conveying means for conveying the residual toner, one end of a helical body like a coil spring is attached to a side plate that partitions one end of the photosensitive drum or a means for rotatably supporting the side plate. A residual toner collecting device characterized in that the remaining toner is fixed and the other end is disposed on the other end side of the photosensitive drum.