JP2535642Y2 - Toner recovery device in photoconductor unit - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial application field] The present invention is to unitize a latent image carrier such as a photosensitive drum and peripheral devices such as a developing device and a cleaning device in an image forming apparatus such as a copying machine and a printer. The present invention also relates to a toner collecting device applied to a system in which the photosensitive unit can be replaced.

[Prior Art] Conventionally, an electrostatic latent image formed on a photoreceptor such as a drum is
After developing with the toner in the two-component or two-component developer and transferring the developed toner image, the toner remaining on the photoreceptor is collected from the photoreceptor by a brush or a blade of the cleaning device, and attached to the cleaning device. Most commonly, it is stored in a residual toner collection bin or the like.

By the way, recently, a latent image carrier such as a photosensitive drum and peripheral devices such as a developing device and a cleaning device are unitized, and an image forming apparatus such as a copying machine or a printer in which the photosensitive unit can be replaced after a predetermined number of copies is made. Devices are becoming popular due to their good maintainability. In such a photoreceptor unit, in order to effectively use the space for collecting the residual toner, a method of accommodating the residual toner in a toner collection box provided in the cleaning device and a space in the photosensitive drum is known.

In this toner recovery device, the toner recovery box and the space in the photosensitive drum are connected by a U-shaped toner transport pipe, and a coil spring-shaped spiral body (auger) is provided in the toner recovery box, the toner transport pipe, and the photosensitive drum. ) Is arranged, and the spiral body is driven to rotate, so that the residual toner is sequentially conveyed from the toner collection box into the space inside the photosensitive drum, and it is detected that the toner collection box following the photosensitive drum is full. In such a case, the photoconductor unit is replaced.

[Problems to be Solved by the Invention] In the above-mentioned conventional toner collecting device, when the toner in the photosensitive drum is full, the rotation of the spiral body causes the toner to be pressed against the toner in the photosensitive drum via the transport pipe. Therefore, the reaction force acts on the toner transport pipe,
There is a problem that the toner is dropped or the seal is incomplete and the toner leaks.

Conventionally, in order to prevent this, a double-sided adhesive tape made of urethane foam is wound around both ends of the toner transfer pipe, and then both ends of the toner transfer pipe are pressed into the toner collection box and the photosensitive drum. However, wrapping the tape or press-fitting the pipe to complete the seal requires a great deal of time and cost, and because of the existence of the beginning and end of the tape, the radial length is small. There was a problem that it was not uniform and it was difficult to completely seal.

The purpose of the present invention is to solve the above problems,
An image forming apparatus of a type in which a photosensitive unit in which a photosensitive drum and its peripheral devices are unitized is made replaceable, wherein a toner collecting device for connecting a toner collecting box and a photosensitive drum by a toner conveying pipe is used for toner transfer. An object of the present invention is to simplify a connection operation between both ends of a pipe, a toner collection box and a photosensitive drum, and to improve a sealing property to prevent leakage of toner and falling off of a toner transport pipe.

[Means for Solving the Problems and Action Thereof] In order to achieve the above object, the toner collecting device in the photoconductor unit of the present invention stores the photosensitive drum (3) and its peripheral devices in the housing (11). In an image forming apparatus in which a unitized photoreceptor unit (1) is detachable from an apparatus main body, a toner collection box (31) formed in the housing and an opening (11a) formed in the toner collection box. And a cylindrical member (1) protruding into the housing and rotatably supporting the photosensitive drum.
3), a toner conveying pipe (43) connecting the opening and the cylindrical member, and a sealing projection (43a) and a stopper projection formed at both ends of the toner conveying pipe over the entire circumference. (43b), and the cylindrical member is provided with a flange portion (13
a) and a cylindrical portion (13b) for supporting the photosensitive drum, the opening diameter of the flange portion is set smaller than the inner diameter of the cylindrical portion, and the outer diameter of the sealing projection is set to the opening portion and the cylindrical portion. The sealing member is press-fitted into the opening and the tubular member, and the stopper projection is brought into contact with the opening and the peripheral edge of the tubular member. Note that the numbers added to the above configuration are compared with the drawings to facilitate understanding of the present invention, and the present invention is not limited thereto.

In the present invention, when both ends of the toner conveying pipe are inserted into the opening to be attached to the toner collecting box and the photosensitive drum, the sealing projection of the toner conveying pipe is pressed into the opening, and the stopper for the pipe is formed. The projection is brought into contact with the opening to establish connection. Therefore, since the sealing projection of the toner conveying pipe is press-fitted into the opening, connection work between both ends of the pipe, the toner collection box and the photosensitive drum is simplified, and the sealing property is improved. can do.

Further, by setting the opening diameter of the flange portion formed in the opening portion to be smaller than the inner diameter of the cylindrical portion, a retaining step is formed, and the toner in the photosensitive drum becomes full,
Even if the reaction force acts on the toner transport pipe, the sealing projection abuts against the retaining step, so that the toner transport pipe can be prevented from falling off.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.

The overall configuration of an example of a copying machine using a photoreceptor unit according to the present invention includes a photoreceptor unit including a photosensitive drum, a cleaning device, and a charging device, a developing device unit, and a transfer device unit in addition to an exposure device fixed to the device. , A fuser unit, and a paper tray, each of which is independently configured to be able to be pulled out toward the front of the apparatus, and each unit can be removed from the apparatus for maintenance such as paper jam, cleaning, and replacement. It has become. The photoreceptor unit is configured to be replaced with a new one every 100,000 copies, for example. Ten
The residual toner collected from the photosensitive drum by the cleaning device during every 10,000 copies is automatically and reliably collected and stored in the photoconductor unit, and the user contacts the residual toner collected in the photoconductor unit. There is no.

FIG. 1 is an enlarged sectional view showing one embodiment of the present invention, FIG. 2 is a sectional view taken along a line perpendicular to the rotation axis of a photosensitive drum of a photosensitive unit, and FIG. 3 is a sectional view taken along line II-II of FIG. FIG. 2 shows a cross-sectional view taken along the arrow direction.

2 and 3, the photosensitive drum 3 is fitted with die-cast cylindrical side plates 5 and 7 at both ends, and the residual toner is accommodated in a space partitioned by the photosensitive drum 3 and the side plates 5 and 7. This constitutes a first container 4. A rotary shaft 9 is integrally provided at the center of the side plate 7 on the rear side of the photosensitive drum 3, and is rotatably attached to a housing 11 of the photosensitive unit 1 via a bearing.

A circular opening is provided at the center of the side plate 5 on the front side, and is rotatably fitted via a bearing 14 to a cylindrical member 13 projecting from the opening 11b of the housing 11 to the inside of the unit via a bearing 14. 13 is rotatably supported. A driven gear 15 for the drum is cut on the outer periphery of the side plate 7 on the rear side, and when the photoconductor unit 1 is pushed into the apparatus main body from the front side and set, the drum driving gear 15 on the apparatus main body side (not shown). Zu) to be engaged.

A positioning hole (not shown) into which the tip of the rotating shaft 9 protruding out of the housing 11 is fitted, and a shaft (not shown) fitted into a positioning hole 16 provided in the housing 11 are provided on the apparatus body side. ) Are provided.

A cleaning brush 17 is rotatably provided between bearings 11 at both ends of the photosensitive drum 3 between extended side walls of a housing 11 through bearings.
The cleaning brush 17 rotates in contact with the photosensitive drum 3 to sweep off toner remaining on the drum 3 without being transferred by the transfer device. A brush rotating gear 21 is fixed to the rear end (rear side of the apparatus) of the rotating shaft 19 of the cleaning brush 17, and meshes with a rotating gear 29 of a toner transport rotary paddle 27 described later. Further, downstream from the contact point between the photosensitive drum 3 and the cleaning brush 17, the other side of which one side is fixed to the support member 11 'provided on the housing 11 is in contact with the drum 3 at an acute angle with respect to the rotation direction. An elastic cleaning blade 23 is provided to scrape off the toner left behind by the cleaning brush 17 from the photosensitive drum 3.

The photosensitive unit 1 includes a cleaning blade.
Downstream of 23, a charger 24 for uniformly charging the cleaned photosensitive drum 3 for forming a latent image is provided.

Further, in order to transport 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, the cleaning brush 17 in the housing 11 is moved.
On the rear side (far side from the drum 3), a toner conveying rotary paddle 27 is provided rotatably via a bearing in parallel with the rear side. A gear 29 is fixed to the rear end of the shaft of the rotary paddle 27 and meshes with the 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 in the figure.

The housing 11 has a toner collection box 31 as a second container for storing residual toner formed behind the cleaning device 30 including the cleaning brush 17, the cleaning blade 23, and the toner conveying rotary paddle 27. 30 and the toner recovery box 31 are partially separated by a partition wall 32. An elastic plate-like member 34 is provided so that one end is fixed to the partition wall 32 and extends downward, and the lower end thereof is in elastic contact with the plane of the rotary paddle 27. The rotating paddle 27 has a regular polygonal cross section as shown in the figure, and is rotated in the direction of the arrow shown in the figure to rotate the cleaning brush 17.
To scrape the residual toner accumulated on the rear side into the toner collection box 31. The plate-like member 34, whose tip is in elastic contact with the surface of the polygonal cross section, has a function of scraping off the toner adhered to the surface and a function of returning the toner accumulated in the toner collection box 31 to the inside of the cleaning device 30 again. Has the effect of preventing.

A rotating shaft 33 is rotatably provided on the rear housing 11 near the bottom of the toner collection box 31. On the toner collection box 31 side, a strip-shaped plate-like member is formed with a normal to the surface. An elastic toner conveying auger 35 formed in a helical shape (spiral shape) so as to face the axial direction is coaxially fixed. An auger rotation gear 37 is attached to the rear end of the rotation shaft 33. The toner transport auger 35 extends along the bottom of the toner recovery box 31 in parallel with the toner transport rotary paddle 27 and the like.

Further, an opening 11a is formed in a front wall of the housing 11 at a position facing the toner transport auger 35. A toner conveying pipe 43 having an inner diameter slightly larger than the cross section of 35 is press-fitted, and the toner conveying auger 35 bends along the U-shaped pipe 43,
The tip 45 projects into the space 4 in the drum 3. As described above, the toner conveying auger 35 has a shape of a flexible helical spring, and when it is rotated, the toner conveying auger 35 acts to convey the toner that has entered between the blades in the axial direction by the principle of a helical pump. Is what you do. Therefore, by rotating the toner collection box 31 in the toner collection box 31, the residual toner at the bottom of the toner collection box 31 can be transferred to the space 4 in the drum 3 along the toner transfer pipe 43.

Note that both the gear 37 for rotating the toner transport auger 35 and the gear 29 for rotating the rotary paddle 27 are driven by a cleaner driven gear rotatably provided on the rear wall of the housing 11.
When the photosensitive unit 1 is set in the apparatus main body, the cleaner driven gear 47 meshes with a cleaner driving gear (not shown) provided in the main body, and the cleaning brush 17 is driven. Then, the toner transport rotation paddle 27 and the toner transport auger 35 are rotated.

The operation of the copier having the above-described configuration will be described. The photosensitive drum 3 uniformly charged by the charger 24 is subjected to image exposure in an exposure unit (not shown), and an electrostatic latent image is formed on the surface of the photosensitive drum 3. Is formed. Next, in a developing device (not shown), toner charged to a polarity opposite to the charge of the electrostatic latent image is brought into contact with the surface of the photosensitive drum 3 to form a toner image. The toner image contacts a sheet conveyed at the same speed as the peripheral speed of the photosensitive drum 3 and is transferred onto the sheet in a transfer device (not shown) provided at the next position. The sheet on which the toner image has been transferred is conveyed to a fixing device, where the toner image is fixed on the sheet and discharged from the apparatus. On the other hand, the photosensitive drum 3 reaches the cleaning device 30, and the toner remaining on the surface thereof 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 removed by a toner transport rotation paddle 27 rotating at this position by a toner collection box 31 provided adjacent to the cleaning device 30.
It is raked out. The residual toner scraped into the toner recovery box 31 is transported to the space 4 in the photosensitive drum 3 via the toner transport pipe 43 by the rotation of the toner transport auger 35.

Next, one embodiment of the toner collecting device of the photosensitive unit according to the present invention will be described with reference to FIG. The figure shows an enlarged cross-sectional view of a connecting portion between the toner conveying pipe 43 and the opening 11b on the side of the cylindrical side plate 5.

The opening 11b is a cylindrical member 13 fixed to the housing 11.
The cylindrical member 13 has a flange portion 13a and a cylindrical portion 13b, and the opening diameter of the flange portion 13a is formed smaller than the inner diameter of the cylindrical portion 13b. A stopper portion 13c is formed between the housing 11 and the flange portion 13a. The flange portion 13a is fixed to a front wall of the housing 11.
A drum side plate 5 is rotatably fitted via 4. Note that the tubular member 13 may be formed integrally with the housing 11.

On the other hand, the toner conveying pipe 43 containing the toner conveying auger 35 is formed by resin molding with an elastic material such as polyethylene, and a sealing projection 43a is integrally formed at the tip of the pipe 43 over the entire circumference. A stopper projection 43b is formed integrally over the entire circumference inside the sealing projection 43a. Note that the sealing projection 4
The outer diameter of 3a is the opening 11b, that is, the cylindrical portion 13b of the cylindrical member 13.
The outer diameter of the stopper projection 43b is set slightly larger than the inner diameter of the flange 13a.

Then, when the tip of the toner conveying pipe 43 is inserted into the cylindrical member 13, the sealing projection 43a of the pipe 43 is press-fitted into the flange portion 13a and the cylindrical portion 13b of the cylindrical member 13, and the pipe 43 is pressed. The stopper projection 43b is brought into contact with the periphery of the opening 11b, that is, the flange 13a, and the connection is completed.

The structure of the connecting portion between the other end of the toner conveying pipe 43 and the opening 11a is the same as described above. In this case, a step for retaining is projected on the opening side of the opening 11a.

Accordingly, the sealing projection 43a of the toner conveying pipe 43 is provided.
Is pressed into the openings 11a and 11b,
The connection work between the both ends of 43 and the toner collection box 31 and the photosensitive drum 3 can be simplified, and the sealing property can be improved. Further, even if the toner in the photosensitive drum 3 becomes full and the reaction force acts on the pipe 43, the sealing projection 43a abuts on the retaining step 13c, so that the pipe 43 can be prevented from falling off. .

Note that the present invention is not limited to the above embodiment, and various modifications are possible.

For example, in the above-described embodiment, an example of the photoconductor unit having two driving diameters of the photoconductor drum and the cleaning device has been described. However, for example, a developing device or the like may be added to the photoconductor unit.

[Effects of the Invention] As described above, according to the present invention, in the image forming apparatus of the type in which the photosensitive drum and its peripheral devices are unitized, the projection portion for sealing the toner conveying pipe is used. Is pressed into the openings formed on the toner collection box side and the photosensitive drum side, simplifying the connection work between both ends of the toner transport pipe and the toner collection box and the photosensitive drum, and sealing. The toner can be prevented from leaking and the toner transport pipe can be prevented from falling off by improving the performance.

[Brief description of the drawings]

FIG. 1 is an enlarged sectional view showing an embodiment of the toner collecting device in the photoconductor unit of the present invention, FIG. 2 is a cross-sectional view taken perpendicular to the rotation axis of the photosensitive drum of the photoconductor unit, and FIG. 2 is a sectional view taken along the line II-II of FIG. 2 and viewed from the direction of the arrow. 1 photoconductor unit, 3 photoconductor drum, 11a, 11b
… Opening, 13a …… Flange, 13b …… Tube, 30…
Cleaning device, 31 ... Toner collection box, 43 ...
Toner conveying pipe, 43a …… Seal projection, 43b ……
Protrusion for stopper.

Claims (1)

(57) [Scope of request for utility model registration] 1. An image forming apparatus in which a photosensitive drum and its peripheral devices are housed in a housing and a unitized photosensitive unit is detachable from an apparatus main body, a toner collection box formed in the housing, and the toner An opening formed in the collection box, a cylindrical member protruding into the housing and rotatably supporting the photosensitive drum, a toner conveying pipe connecting the opening to the cylindrical member, and the toner conveying A seal projection and a stopper projection formed over the entire circumference at both ends of the pipe, and the cylindrical member supports a flange portion with which the stopper projection abuts, and a photosensitive drum. An opening diameter of the flange portion is set smaller than an inner diameter of the cylindrical portion, and an outer diameter of the sealing protrusion is larger than an inner diameter of the opening portion and the inner diameter of the cylindrical member. And a stopper projection is pressed into the opening and the cylindrical member, and a stopper projection is brought into contact with the opening member and the peripheral edge of the cylindrical member. apparatus.