JP2002087591A - Powder carrying device, and image forming device having same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To easily conduct cleaning work to discharge toner from a powder carrying passage in a powder carrying device to carry powder of toner contained in a powder container through the powder carrying passage by sucking action of a powder pump. SOLUTION: A release port 16 is provided in a powder inlet tube 15 adjacent to a rotor 8 and a stator 7 of the powder pump 5, a cover 17 is removed in cleaning the powder carrying passage, and atmospheric air is sucked from the release port 16 into the powder carrying passage to discharge toner inside.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a powder transfer device and an image forming apparatus having the transfer device.

[0002]

2. Description of the Related Art A powder transfer device which operates a powder pump and transfers powder in a powder container to a powder pump through a powder transfer path by a suction action thereof is used in many technical fields. For example, in an image forming apparatus configured as a copier, a printer, a facsimile, or the like,
A powdery toner for visualizing a latent image formed on the image carrier is transferred by a powder transfer device and supplied to a developing device. Further, the above-described powder transfer device can be used for transferring powder such as cement and grain powder.

[0003] By the way, powder is transferred through a powder transfer path, and it may be necessary to discharge the powder from the powder transfer path and clean the transfer path. For example, when a powder transfer device is employed in an image forming apparatus, before the image forming apparatus is shipped from a factory,
The toner is supplied to the developing device by the powder transfer device, a toner image is formed on the image carrier by the toner, and the state of the image forming apparatus is inspected. If the image forming apparatus is shipped while the toner remains in the transfer path, the toner in the powder transfer path is aggregated and fixed until the image forming apparatus is used by the user, The powder transfer path is clogged. Therefore, it is necessary to discharge the toner in the powder transfer path before shipping the image forming apparatus.

Therefore, for example, if the powder container is emptied and the powder pump is operated in this state to discharge the powder in the powder transfer path, the powder transfer path is cleaned. Is possible. However, in general, the ability of a powder pump to transfer powder, that is, the amount of powder transferred per unit time is not so large. Discharge requires a lot of time.

[0005] Therefore, it is possible to forcibly suck the powder transfer path by connecting the suction port of the suction device to the end of the powder transfer path opposite to the powder pump side, and to discharge the powder inside the powder transfer path. Conceivable. However, since the end of the powder transfer path on the powder pump side is connected to the powder pump, the inside of the powder transfer path is evacuated even if strongly suctioned from the opposite end. However, the powder cannot be efficiently discharged from the powder transfer path.

[0006]

SUMMARY OF THE INVENTION The present invention has been made on the basis of the above-described novel recognition, and a first object of the present invention is to reduce the efficiency of powder transfer in a powder transfer path without reducing the powder transfer efficiency. An object of the present invention is to provide a powder transfer device capable of easily performing cleaning.

A second object of the present invention is to provide an image forming apparatus having the above-described powder transfer device.

[0008]

According to the present invention, in order to achieve the first object, powder in a powder container is transferred to a powder pump through a powder transfer path by a suction action of the powder pump. A powder transfer device that is normally closed and has an opening for communicating the powder transfer route to the outside when cleaning the powder transfer route. (Claim 1).

At this time, the operation of the powder pump is stopped,
In addition, it is possible to adopt a configuration in which the powder transfer path is sucked and the powder in the powder transfer path is discharged while the opening is opened (claim 2).

[0010] In the powder transfer device according to claim 1 or 2, the opening is advantageously provided at a downstream end of the powder transfer path in the powder transfer direction or in the vicinity thereof. Item 3).

Further, according to the present invention, in order to achieve the second object, a powder transfer device according to any one of claims 1 to 3, and a developing device for forming a toner image on the surface of an image carrier. An image forming apparatus is provided that supplies the developing device with the powdery toner transferred by the powder transfer path (claim 4).

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below in detail with reference to the drawings.

FIG. 1 shows a powder transfer device 2 and a developing device 3 disposed in a main body of an image forming apparatus configured as a copier, a printer, a facsimile, or a multifunction machine having at least two of these functions. FIG. As is well known per se, in the developing container 4 of the developing device 3, for example, a powdery two-component developer (not shown) having a toner and a carrier is contained, and the toner in the developer causes Similarly, a toner image is formed on the surface of an image carrier (not shown). When a toner concentration sensor (not shown) detects a decrease in the toner concentration of the developer in the developing container, a powdery toner is supplied to the developing container 4 by the powder transfer device 2. The powder transfer device 2 of this example is configured as follows.

First, the powder transfer device 2 includes a powder pump 5
, A powder container 37, and a powder transfer pipe 51 connecting them.
As shown in FIG. 2, the powder container 37 contains a toner T which is an example of powder. Powder container 37
Is set in the image forming apparatus main body so as to be attachable and detachable, and a powder sealing member 3 made of a tubular foam is provided in an opening 38 below the main body.
9 is attached.

One end of a powder discharge pipe 45 and one end of an air supply pipe 46 are inserted into the center hole of the powder sealing member 39. The opening 38 of the powder container 37 is detachably fitted to the powder discharge pipe 45 and the air supply pipe 46. An annular air flow path 47 is provided between the powder discharge pipe 45 and the air supply pipe 46.
The powder discharge pipe 45 and the air supply pipe 46 are integrally fixed. A powder discharge port 44 is formed at one end of the powder discharge pipe 45 inserted into the powder container 37, and one end of the powder transfer pipe 51 is connected to the other end of the powder discharge pipe 45. Have been. An air outlet 48 at one end of the air supply pipe 46 is open to the powder container 37, and the other end of the air supply pipe 46 is connected to an air discharge port of an air pump 50 via a conduit 49. ing. Powder transfer tube 5
1 is made of a rigid body such as metal or hard resin, or is made of a flexible tube made of rubber or soft resin.

On the other hand, as shown in FIG. 3, the powder pump 5 of this embodiment has a cylindrical stator 7 having a through hole 6 in which two spirally extending grooves are formed on the inner peripheral surface thereof. Stator 7
And a rotor 8 rotatably arranged in the through-hole 6 of the first embodiment. The rotor 8 spirally extends so as to form a gap S for powder transfer between the rotor 8 and the inner peripheral surface of the through hole of the stator 7. That is, the rotor 8 has a circular cross section in any of its cross sections, and the center of the circle is eccentric with respect to the central axis of the rotor 8 and spirally extends around the central axis. The stator 7 is in contact with the rotor 8 so as to enclose the rotor 8 having a spiral structure, and is fixedly held by the case 9. The rotor 8 is made of a rigid body such as a metal, and the stator 7 is made of an elastic body such as a rubber. The powder pump having the rotor 8 and the stator 7 is called a uniaxial eccentric screw pump or a mono pump.

The powder pump 5 has a connecting shaft 11 connected to one end of the rotor 8 via a pin joint 10, and the connecting shaft 11 is connected to a driving shaft 18 via another pin joint 19. The drive shaft 18 is rotatably supported via a bearing 12 by a casing 13 whose lower part is open. A gear 14 is fixed to a drive shaft portion protruding to the outside of the casing 13, and a mating gear (not shown) meshes with the gear 14, and the rotation of a drive motor (not shown) is also driven via these gears. It is transmitted to the shaft 18 and the connecting shaft 11, whereby the rotor 8 is configured to be driven to rotate around its central axis.

The lower part of the casing 13 is connected to the developing container 4 of the developing device 3, and the inside of the casing 13 and the inside of the developing container 4 communicate with each other. The casing 13 is fixedly connected to the case 9 described above.

One end of a powder inlet pipe 15 is integrally connected to the end of the case 9 opposite to the side where the connecting shaft 11 is located. The other end of the body transfer pipe 51 is connected.

As described above, the toner density sensor
When a decrease in the toner concentration of the two-component developer in the developing container 4 is detected, the air pump 50 shown in FIG. 2 starts operating, and the drive shaft 18 and the connecting shaft of the powder pump 5 shown in FIG. 11 is driven to rotate, and the rotor 8 starts rotating.

By the operation of the air pump 50, the air sent from the air pump 50 is sent to the air supply pipe 46 through the conduit 49, and then the air passes through the air flow passage 47,
As shown by an arrow in FIG.
Supplied within. Thereby, the powder in the powder container 37,
In this example, the powdery toner T is loosened and fluidized,
It becomes a state easily sucked.

On the other hand, when the rotor 8 of the powder pump 5 shown in FIG. 3 rotates, the gap S formed between the through hole 6 of the stator 7 and the outer peripheral surface of the rotor 8 moves rightward in FIG. As a result, a suction pressure is generated, and the toner in the powder transfer pipe 51 passes through the powder inlet pipe 15 and the gap S in the through hole 6.
And transported to the right in FIG. Next, the toner is discharged from the through hole 6 into the casing 13. As described above, the rotation of the rotor 8 can transfer the powdery toner from the inlet opening side of the through hole 6 to the outlet opening side.

Along with this operation, the toner T fluidized in the powder container 37 shown in FIG. 2 is fed into the powder discharge pipe 45 through the powder discharge port 44 and transferred to the powder pump 5. You. Thus, the toner is conveyed into the casing 13 and the toner is supplied into the two-component developer in the developing container 4. After a predetermined time has elapsed, the air pump 50
Then, the operation of the powder pump 5 stops. By performing such toner supply, the toner concentration of the developer in the developing container 4 is maintained within a predetermined range, and a toner image having a predetermined density can be formed on the image carrier.

As described above, the operation of the air pump 50 is
Instead of synchronizing with the operation of the powder pump 5, the air pump 5
0 as appropriate, and the toner T loosened by this
The powder may be transferred to the developing device 3 by the operation of the powder pump 5.

As described above, the powder transfer device 2 transfers the powder in the powder container 37, in this example, the toner T, to the powder pump 5 through the powder transfer path by the suction action of the powder pump 5. Make a transfer. In the illustrated example, the powder discharge pipe 4
5, a powder transfer pipe 51, and a powder inlet pipe 15 constitute a powder transfer path.

By the way, the above-mentioned image forming apparatus is manufactured at a factory and shipped to a user. As described above, before the shipment, the powder transfer device 2 is moved to the powder transferring apparatus 2 as described above. When the inspection is performed to supply the toner to the developing device and form a toner image on the image carrier, after the inspection is completed, the toner in the powder transfer path is discharged and the powder transfer is performed. The route needs to be cleaned.

In order to facilitate such cleaning, in the powder transfer device of this embodiment, as shown in FIG. 3, an opening 16 is provided in the middle of the powder transfer path. In the example shown, an opening 16 is provided in the powder inlet tube 15, which is normally closed by a lid 17 screwed into it.

When the toner in the powder transfer path is discharged and the inside of the powder transfer path is cleaned, as shown in FIG.
The operation of the powder pump 5 is stopped, the lid 17 is removed, and the inside of the powder transfer path is communicated with the outside via the opening 16. On the other hand, the powder container 37 shown in FIG. 2 is pulled upward in FIG. 2 to remove it from the powder discharge pipe 45 and the air supply pipe 46, and is shown in the powder discharge port 44 of the powder discharge pipe 45. Connect the suction port of a vacuum cleaner, for example, a vacuum cleaner, and operate the vacuum cleaner to forcibly suction the powder in the powder transfer path. At this time, since the opening 16 is open, outside air is introduced from the opening 16 and the air is introduced into the powder inlet pipe 1.
5, passes through the powder transfer pipe 51 and the powder discharge pipe 45, and is sucked by the suction machine together with the toner remaining there. In this manner, the toner in the powder transfer path can be discharged to the outside in a short time and can be cleaned.

Although the suction port of the suction device may be connected to the opened opening 16 to discharge the toner in the powder transfer path, the powder pump 5 of the image forming apparatus is Since it is often located at the back of the main body, in the case of the powder transfer device provided in the image forming apparatus, as described above, the end of the powder transfer path opposite to the opening 16 is used. The operation can be performed more easily by taking in the air from the side of the unit and discharging the toner.

When the operation of cleaning the powder transfer path is completed, the powder container 37 is connected to the powder discharge pipe 45 and the air supply pipe 46, and the opening 16 is closed by the lid 17. It goes without saying that an appropriate lid other than the screw-in type lid may be used.

Since the opening 16 is closed by the lid 17, when the image forming apparatus is transported to the user and used, the toner in the powder transfer path does not leak out from the opening.

As described above, when the powder transfer path is normally closed and the powder transfer path is cleaned, the opening for communicating the powder transfer path with the outside is provided to reduce the powder transfer efficiency. In addition, it is possible to easily and quickly clean the inside of the powder transfer path. Specifically, with the operation of the powder pump 5 stopped and the opening 16 opened, the powder transfer path can be sucked and the powder in the powder transfer path can be discharged. .

The open port 16 can be provided at an appropriate position in the powder transfer path. However, if the open port 16 is provided at the downstream end of the powder transfer path in the powder transfer direction or in the vicinity thereof, the suction port is used. When inhaling, the suction action is exerted over the entire length of the powder transfer path, and the powder in the powder transfer path can be efficiently discharged. Further, a plurality of open ports may be provided. In the example shown in FIG. 3, one opening 16 is provided in the powder inlet pipe 15 near the powder pump 5.

The powder transfer device 2 of the above-described example is configured to transfer a powder made of toner, and the image forming apparatus and the powder transfer device 2 form a toner image on the surface of an image carrier. And the developing device 3 is configured to supply the powdery toner transferred from the powder transferring device 2 to the developing device 3. The present invention can be widely applied to a powder transfer device. Further, as the powder pump, various pumps other than the MONO pump can be appropriately used.

[0035]

According to the first to third aspects of the present invention, the powder transfer path can be easily cleaned without lowering the powder transfer efficiency.

According to the fourth aspect of the present invention, it is possible to provide an image forming apparatus having the above effects.

[Brief description of the drawings]

FIG. 1 is a diagram illustrating a developing device and a powder transfer device disposed in an image forming apparatus main body.

FIG. 2 is a sectional view showing a powder container and a powder transfer pipe connected to the powder container.

FIG. 3 is a sectional view of a powder pump.

FIG. 4 is a cross-sectional view showing a state when the powder transfer path is cleaned.

[Explanation of symbols]

 2 Powder transfer device 3 Developing device 5 Powder pump 16 Open port 37 Powder container T Toner

Continuation of the front page (72) Inventor Takaaki Yanagisawa 1-3-6 Nakamagome, Ota-ku, Tokyo Inside Ricoh Company (72) Inventor Masumi Sato 1-3-6 Nakamagome, Ota-ku, Tokyo Inside Ricoh Company (72) Inventor Shota Fujimori 1-3-6 Nakamagome, Ota-ku, Tokyo Inside Ricoh Co., Ltd. (72) Inventor Yoshio Hattori 1-3-6 Nakamagome, Ota-ku, Tokyo F-term in Ricoh Co., Ltd. Reference) 2H077 AA03 AA25 AA35 AC11 BA02 DA10 DA42 DB01 EA03 3F047 AA03 BA10

Claims (4)

[Claims] 1. A powder transfer apparatus for transferring powder in a powder container to a powder pump through a powder transfer path by a suction action of a powder pump. An opening for communicating the powder transfer path with the outside when the transfer is performed. 2. The method according to claim 1, wherein the operation of the powder pump is stopped and the powder transfer path is sucked to discharge the powder in the powder transfer path in a state where the opening is opened. A powder transfer device as described in the above. 3. The powder transfer device according to claim 1, wherein the opening is provided at or near a downstream end of the powder transfer path in the powder transfer direction. 4. A powder transfer device, comprising: the powder transfer device according to claim 1; and a developing device that forms a toner image on a surface of an image carrier. An image forming apparatus for supplying a toner in the form of a toner to the developing device.