JPH0353233Y2 - - Google Patents

Description

[Detailed Description of the Invention] Industrial Application Field The present invention relates to a toner recovery device for recovering toner removed by a cleaning device from the surface of a photoreceptor in a copying machine or the like.

Conventional technology Generally, in a copying machine using xerography, an electrostatic latent image formed by exposing a uniformly charged photoreceptor is developed into a toner image, and this toner image is transferred to a transfer material such as paper. After being transferred to a computer, it is fixed and a copy is obtained. Toner remaining on the photoreceptor after transfer is usually removed by a cleaning device. Typical cleaning devices include those that have an elastic blade in contact with the photoreceptor, those that use a rotationally driven brush to forcibly remove residual toner from the photoreceptor, and those that use magnetic brushes used in developing devices. Examples include those that are used for both purposes.

Among these, brush cleaning devices using brushes have good toner removal efficiency, and are therefore used in high-speed copying machines that use belt-shaped photoreceptors.The toner removed from the photoreceptor is usually removed by a blower filter bag and/or
Alternatively, the toner is collected by a toner collection device configured using a cyclone or the like.

A toner recovery device configured using a cyclone has a configuration as shown in FIG. 4, for example, and includes a cyclone 1 connected to a brush cleaning device (not shown), and an impeller 21 provided inside the cyclone 1. a rotary valve 2 having a
It is comprised of an auger (not shown) that is fitted into a hole 20 provided at the bottom of the rotary valve 2 and extends in a direction perpendicular to the drawing.

The toner forcibly removed from the surface of the photoreceptor by the brush cleaning device is guided into the cyclone 1 by a blower (not shown) along with air in a spiral, and only the toner with a large mass is passed through the side of the cyclone by centrifugal force to the rotary valve. Guided by 2. The impeller 21 provided in the rotary valve is rotated by a rotation driving means (not shown), sealingly isolates the inside of the cyclone 1 and the inside of the hole 20 provided at the bottom of the rotary valve 2, and also transports the toner in the direction of arrow A in the figure. Transport to. hole 20
The toner sent to the cyclone is transported in a desired direction by an auger (not shown) without being affected by the negative pressure inside the cyclone.

Problems to be Solved by the Invention In such a toner recovery device, if the sealing performance of the rotary valve 2 is not good, the pressure difference between the negative pressure inside the cyclone 1 and the atmospheric pressure inside the auger will cause the auger to There was a problem in that the toner collected inside the rotary valve 2 flows back into the rotary valve 2, resulting in a decrease in toner collection efficiency. For this reason, it is required to control and maintain the machining accuracy of rotary valves, resulting in high costs, and there has been a demand for reduced inspection man-hours and maintenance-free manufacturing.

Therefore, an object of the present invention is to provide a toner recovery device in which the toner recovery rate is not directly affected by the sealing performance of the rotary valve.

Means for Solving the Problems In order to solve the problems of the prior art described above, the present invention provides a cyclone that collects toner by centrifugal separation, a rotary valve that sends the collected toner to the outside of the cyclone, and the rotary valve. In the toner recovery device, the rotary valve includes a housing, and an impeller that rotates while separating a cyclone side space and an auger side space in the housing, A toner recovery device is provided in which the housing is provided with a ventilation hole communicating from the auger side space to the outside of the housing.

Effect In the configuration of the present invention, the rotary valve equipped with a housing and an impeller that rotates while isolating the cyclone side space and the auger side space in the housing is used because the pressure inside the cyclone and the auger is This is to prevent the toner once collected in the auger from flowing back into the cyclone due to the difference. As described above, if the sealing performance of the impeller in this rotary valve is not good, the toner will flow backwards and the toner recovery efficiency will be reduced. In this invention, the housing of the rotary valve is provided with a ventilation hole that communicates from the auger side space to the outside of the housing, so if the impeller in the rotary valve does not have good sealing, only air will be allowed to flow through this ventilation hole. Flows into the cyclone, eliminating the risk that the toner once collected by the auger will flow back into the cyclone. As described above, according to the present invention, it is possible to provide a toner recovery device in which the toner recovery rate is not directly affected by the sealability of the rotary valve.

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

Referring to FIG. 3, an example of a copying machine to which the toner recovery device of the present invention is applied is shown, in which a belt-shaped photoreceptor 16 is wound around a tension roll 5, a drive roll 3, and a stripper roll 4. ing. Various devices for uniform charging, exposure, development, transfer, and cleaning are provided around the belt-shaped photoreceptor 16. To explain these operations, first, the belt-shaped photoreceptor rotates in the direction of arrow B. 1
6 is uniformly charged by a charging corotron 17, and an electrostatic latent image is formed on its surface by a flash exposure system 15. This electrostatic latent image is turned into a toner image by a developing device 6 that supplies a developer containing toner, the charge is adjusted by a pre-transfer corotron 7, and the image is sent by a transfer corotron 10 via an inlet chute 8. The image is transferred to the paper 9 that comes next. After completing the transfer, the paper adsorbed on the belt-shaped photoreceptor 16 is peeled off by a peeling corotron 11, and transferred to a prefuser transport 12, which is made up of a belt wound between a pair of rollers, by a suction means (not shown). The paper is carried and discharged onto a tray or the like via a fixing device (not shown).

On the other hand, the belt-shaped photoreceptor 1 after the paper has been peeled off
6 is statically neutralized by a static eliminating corotron 13 as required, and the toner remaining on the surface thereof is removed by a cleaning device 14, and is reused.
A brush 18 that rotates while rubbing the belt-shaped photoreceptor 16 is provided inside the cleaning device 14, and the toner removed by the brush is sucked by a blower (not shown) and sent to the toner recovery device according to the present invention. Sent. Incidentally, reference numeral 19 denotes a static elimination lamp that irradiates light from inside the belt-shaped photoconductor 16 to eliminate static electricity from the belt-shaped photoconductor 16.

The structure of the toner recovery device is best shown in FIG. 2 is a rotary valve connected to the cyclone 1, and a housing 22 is fixed to the frame 33 of the copying machine with a bolt 32;
It is composed of a lid member 23 that seals the housing 22, and an impeller 21 that is rotatably supported via a bearing 24 provided on the housing 22 and the lid member 23. A first gear is provided at one end of the impeller 21. 2
5 is provided.

A hole 20 that communicates with the rotation space of the impeller 21 is provided below the housing 22, and a pipe 31 is fitted into this hole. A screw 29 is rotatably supported inside the pipe 31 via a bearing 34 provided in the housing 22, and forms an auger 28 together with the pipe 31. Further, at one end of the screw 29, a second gear 26 meshing with the first gear 25 and a sprocket 27 connected to a rotation drive means (not shown) using a chain or the like are provided in this order. Therefore, by rotating the sprocket 27,
The screw 29 and the impeller 21 rotate at a predetermined speed.

The ventilation hole 36, which is characteristic of the present invention, is formed in the housing 22 so that one end opens into a space (hereinafter referred to as a connection part) 37 defined between the rotation space of the impeller 21 and the auger 28. The other end is open to the outside of the housing 22, as shown in FIG. 35 rolls freely while contacting the screw 29 within the connecting portion 37,
These are steel balls that prevent toner from sticking to screws, etc.

Now, the toner that has been centrifuged by the rotating airflow generated in the cyclone 1 falls into the rotary valve 2 due to gravity, is guided to the auger 28 by the rotation of the impeller 21, and is further placed in the right direction in the figure by the rotation of the screw 29. The collected toner is transported to a toner collection box (not shown) or the like.

Toner was actually collected from the cleaning device using a conventional device with the same structure except for the toner recovery device and ventilation holes as described above, and with the air volume of the blower connected to cyclone 1 being 600 liters/min. In the case of the conventional product, the amount of air leakage from the rotary valve 2 was 6 liters/min and the toner recovery rate was reduced, but in the product of the present invention, for example, the vent hole 36 is formed with a diameter of 5 mm. The toner recovery rate did not decrease despite air leakage of 20 liters/minute.

Effects of the Invention As detailed above, the toner recovery device of the present invention has the effect that the toner recovery rate does not decrease even if there is some air leakage from the rotary valve.

[Brief explanation of the drawing]

Fig. 1 is a cross-sectional configuration diagram of the toner recovery device of the present invention, Fig. 2 is a front view when the lid member of the rotary valve constituting the toner recovery device of the present invention is opened, and Fig. 3 is a cross-sectional view of the toner recovery device of the present invention. FIG. 4 is a schematic cross-sectional configuration diagram showing an example of a conventional toner recovery device. 1...Cyclone, 2...Rotary valve,
14...Cleaning device, 18...Brush, 2
1... impeller, 28... auger, 35... steel ball, 36... ventilation hole, 37... connection part.

Claims (1)

[Claim for Utility Model Registration] Toner recovery system consisting of a cyclone that collects toner by centrifugal separation, a rotary valve that sends the collected toner outside the cyclone, and an auger that transports the toner sent out by the rotary valve. In the device, the rotary valve includes a housing 22;
The housing includes an impeller 21 that rotates while separating the cyclone side space and the auger side space in the housing, and the housing 22 is provided with a ventilation hole 36 that communicates from the auger side space to the outside of the housing. Characteristic toner collection device.