JP4428678B2 - Developer transfer device and image forming apparatus having the transfer device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a developer transfer device and an image forming apparatus having the transfer device.
[0002]
[Prior art]
A powder transfer device that operates a powder pump and transfers the powder in the powder container to the powder pump through a powder transfer path by its suction action is used in many technical fields. For example, in an image forming apparatus configured as a copying machine, a printer, a facsimile machine, or the like, powdery toner for visualizing a latent image formed on an image carrier is transferred by a powder transfer device, This is supplied to the developing device. Moreover, the above-mentioned powder transfer apparatus can also be used for the purpose of transferring powder such as cement and grain flour.
[0003]
By the way, although the powder is transferred through the powder transfer path, 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 the factory, toner is supplied to the developing device by the powder transfer device, and the toner is applied to the image carrier by the toner. A toner image is formed and the state of the image forming apparatus is inspected. After the inspection, it is assumed that the image forming apparatus is shipped in a state where the toner remains in the powder transfer path. For example, before the image forming apparatus is used by the user, the toner in the powder transfer path is agglomerated and fixed, and 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.
[0004]
Therefore, for example, if the powder container is left empty and the powder pump is operated in this state to discharge the powder in the powder transfer path, the powder transfer path can be cleaned. is there. However, in general, the ability of the powder pump to transfer the powder, that is, the amount of powder transferred per unit time is not so large, so that the powder in the powder transfer path is activated by the operation of the powder pump as described above. When it is discharged, a lot of time is required for the work.
[0005]
Therefore, it is conceivable that the suction port of the suction device is connected to the end of the powder transfer path opposite to the powder pump side to forcibly suck the powder transfer path and discharge the powder inside. 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 in a vacuum state even if it is strongly sucked from the opposite end. Therefore, the powder cannot be efficiently discharged from the powder transfer path.
[0006]
[Problems to be solved by 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 provide a developer transfer device capable of cleaning the developer transfer path easily and in a short time. is there.
[0007]
A second object of the present invention is to provide an image forming apparatus having the developer transfer device described above.
[0008]
[Means for Solving the Problems]
In order to achieve the first object, the present invention provides a developer that transfers the powdery developer in the developer container to the uniaxial eccentric pump through the developer transfer path by the suction action of the suction type uniaxial eccentric pump. In the transfer device, the uniaxial eccentric pump includes a case that forms an outer shell thereof, and an upstream end in the developer transfer direction of the developer transfer path is detachably connected to the developer container, and the developer transfer path A powder inlet pipe constituting the most downstream portion in the developer transfer direction is integrally connected to the case of the uniaxial eccentric pump , and an opening for cleaning communicating with the inside of the powder inlet pipe so as to be openable and closable is provided. A developer transfer device is provided which is provided (claim 1).
[0011]
Furthermore, in order to achieve the second object, the present invention includes the developer transfer device according to claim 1 and a developing device that forms a toner image on the surface of the image carrier, and the developer transfer path. According to another aspect of the present invention, there is provided an image forming apparatus that supplies the toner in the form of powder transferred by the above method to the developing device.
[0012]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below in detail with reference to the drawings.
[0013]
FIG. 1 shows a powder transfer device 2 and a developing device 3 arranged in the main body of an image forming apparatus configured as a copying machine, a printer, a facsimile, or a multifunction machine having at least two of these functions. It is a schematic explanatory drawing. As 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 accommodated, and the toner in the developer Similarly, a toner image is formed on the surface of an image carrier not shown. When a decrease in the toner concentration of the developer in the developing container is detected by a toner concentration sensor (not shown), powder toner is supplied to the developing container 4 by the powder transfer device 2. The powder transfer apparatus 2 of this example is configured as follows.
[0014]
First, the powder transfer device 2 includes a powder pump 5, a powder container 37, a powder transfer pipe 51 for connecting them, and the like. As shown in FIG. The toner T, which is an example of the above, is accommodated. The powder container 37 is detachably set in the main body of the image forming apparatus, and a powder sealing member 39 made of a cylindrical foam is attached to the lower opening 38 thereof.
[0015]
One end sides of the powder discharge pipe 45 and the 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 passage 47 is defined between the powder discharge pipe 45 and the air supply pipe 46, and the powder discharge pipe 45 and the air supply pipe 46 are integrally fixed. A powder discharge port 44 is formed at one end side of the powder discharge pipe 45 inserted into the powder container 37, and one end side of the powder transfer pipe 51 is connected to the other end side of the powder discharge pipe 45. Has been. An air outlet 48 on one end side of the air supply pipe 46 is open to the powder container 37, and an air discharge port of the air pump 50 is connected to the other end side of the air supply pipe 46 via a conduit 49. ing. The powder transfer tube 51 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.
[0016]
On the other hand, as shown in FIG. 3, the powder pump 5 of this example has a cylindrical shape having a case 9 forming an outer shell thereof and a through hole 6 in which two grooves extending spirally are formed on the inner peripheral surface. Of the stator 7 and a rotor 8 rotatably disposed in the through hole 6 of the stator 7. The rotor 8 extends spirally so that a powder transfer gap S is formed between the stator 7 and the inner peripheral surface of the through hole. That is, the rotor 8 has a circular shape in any cross section, and the center of the circle is eccentric with respect to the central axis of the rotor 8 and extends spirally around the central axis. The stator 7 is in contact with and engaged 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 metal, and the stator 7 is made of an elastic body such as rubber. The powder pump having the rotor 8 and the stator 7 is called a uniaxial eccentric pump or a Mono pump.
[0017]
The powder pump 5 has a connecting shaft 11 connected to one end side of the rotor 8 via a pin joint 10, and this connecting shaft 11 is further connected to a drive shaft 18 via another pin joint 19. The drive shaft 18 is rotatably supported by a casing 13 having an open lower portion through a bearing 12. A gear 14 is fixed to a drive shaft portion protruding to the outside of the casing 13, and a mating gear (not shown) is engaged with the gear 14, and the rotation of a drive motor (not shown) is also driven through these gears. The rotor 18 is transmitted to the shaft 18 and the connecting shaft 11, whereby the rotor 8 is driven to rotate about its central axis.
[0018]
A lower portion 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.
[0019]
One end side of the powder inlet pipe 15 is integrally connected to the end portion side of the case 9 opposite to the side where the connecting shaft 11 is located, and the above-described powder transfer pipe is connected to the other end side of the powder inlet pipe 15. The other end side of 51 is connected.
[0020]
As described above, when the toner concentration sensor detects a decrease in the toner concentration of the two-component developer in the developing container 4, the air pump 50 shown in FIG. 2 starts operating and the powder shown in FIG. The drive shaft 18 and the connecting shaft 11 of the pump 5 are rotationally driven, and the rotor 8 starts to rotate.
[0021]
By the operation of the air pump 50, the air sent from here is sent to the air supply pipe 46 through the conduit 49, and then the air passes through the air flow passage 47 and flows from the air outlet 48 as shown by the arrow in FIG. 2. It is supplied into the body container 37. As a result, the powder in the powder container 37, in this example, the powdery toner T is loosened, fluidized, and easily sucked.
[0022]
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 to the right in FIG. As a result, a suction pressure is generated, and the toner in the powder transfer pipe 51 is fed into the gap S in the through hole 6 through the powder inlet pipe 15 and conveyed to the right in FIG. Next, the toner is discharged from the through hole 6 into the casing 13. Thus, the rotation of the rotor 8 allows the powdery toner to be transferred from the inlet opening side of the through hole 6 to the outlet opening side.
[0023]
With this operation, the toner T fluidized in the powder container 37 shown in FIG. 2 is sent into the powder discharge pipe 45 through the powder discharge port 44 and transferred to the powder pump 5. In this way, the toner is conveyed into the casing 13, and the toner is supplied into the two-component developer in the developing container 4. When a predetermined time has elapsed, the operations of the air pump 50 and the powder pump 5 are stopped. By 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 concentration can be formed on the image carrier.
[0024]
As described above, instead of synchronizing the operation of the air pump 50 with the operation of the powder pump 5, the air pump 50 is appropriately operated, and the toner T thus loosened is operated by the operation of the powder pump 5 to develop the developing device 3. You may make it transfer to.
[0025]
As described above, the powder transfer device 2 causes the powder in the powder container 37, in this example, the toner T, to flow to the powder pump 5 through the powder transfer path by the suction action of the suction type powder pump 5. Used for transportation. In the illustrated example, a powder transfer path is configured by the powder discharge pipe 45, the powder transfer pipe 51, and the powder inlet pipe 15, and the most downstream side portion of the powder transfer path in the powder transfer direction. Is integrally connected to the case 9 of the uniaxial eccentric pump 5.
[0026]
By the way, the above-described image forming apparatus is manufactured in a factory and shipped to the user. As described above, prior to the shipment, the powder transfer apparatus 2 is operated as described above. When the inspection for supplying the toner to the developing device and forming the toner image on the image carrier is performed, the toner in the powder transfer path is discharged after the inspection is completed, Need to be cleaned.
[0027]
In order to facilitate such cleaning, in the powder transfer device of this example, as shown in FIG. 3, an opening 16 is provided in the middle of the powder transfer path. In the illustrated example, an opening 16 is provided in the powder inlet tube 15, and this opening 16 is normally closed by a lid 17 screwed therein.
[0028]
When the toner in the powder transfer path is discharged and the powder transfer path is cleaned, as shown in FIG. 4, the operation of the powder pump 5 is stopped, the lid 17 is removed, and the opening 16 is opened. The interior of the powder transfer path is communicated with the outside. On the other hand, the powder container 37 shown in FIG. 2 is pulled upward in FIG. 2 to be removed 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 non-suction machine, such as a vacuum cleaner, and activate the suction machine to forcibly suck the powder transfer path. At this time, since the opening 16 is open, external air is introduced from here, and the air passes through the powder inlet pipe 15, the powder transfer pipe 51 and the powder discharge pipe 45, and remains there. It is sucked into the suction machine together with the toner that has been stored. In this way, the toner in the powder transfer path can be discharged to the outside in a short time and cleaned here.
[0029]
The suction port of the suction device may be connected to the opened opening 16 to discharge the toner in the powder transfer path, but the powder pump 5 of the image forming apparatus is provided in the main body of the image forming apparatus. Since it is often located at the back, in the case of the powder transfer device provided in the image forming apparatus, as described above, on the side of the end of the powder transfer path opposite to the opening 16 The work can be performed more easily if the toner is sucked out and discharged.
[0030]
When the cleaning operation of 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 open port 16 is closed by the lid 17. Of course, a suitable lid other than the screw-in lid may be used.
[0031]
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.
[0032]
As described above, when the powder transfer path is normally closed and the powder transfer path is cleaned, by providing an open port for communicating the powder transfer path to the outside, the powder transfer efficiency is not reduced. Cleaning in the body transfer path can be performed easily and in a short time. Specifically, the powder transfer path can be sucked and the powder in the powder transfer path can be discharged while the operation of the powder pump 5 is stopped and the opening 16 is opened. .
[0033]
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 or near the downstream end in the powder transfer direction of the powder transfer path, the air is sucked by the suction device. In addition, a 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. Also, a plurality of open ports may be provided. In the example shown in FIG. 3, one cleaning opening 16 is provided in the powder inlet pipe 15 in the vicinity of the powder pump 5 so as to be openable and closable .
[0034]
The powder transfer device 2 of the example described above is configured to transfer powder made of toner, and the image forming apparatus includes the powder transfer device 2 and a developing device that forms a toner image on the surface of the image carrier. 3 is configured to supply the toner in powder form transferred from the powder transfer device 2 to the developing device 3. The present invention is a powder for transferring various powders other than toner. It can be widely applied to a transfer device. As the powder pump, various pumps other than the MONO pump can be appropriately employed.
[0035]
【The invention's effect】
According to the first aspect of the present invention, the developer transfer path can be cleaned easily and in a short time.
[0036]
According to the invention which concerns on Claim 2, the image forming apparatus which has the said effect can be provided.
[Brief description of the drawings]
FIG. 1 is a diagram illustrating a developing device and a powder transfer device arranged in an image forming apparatus main body.
FIG. 2 is a cross-sectional view showing a powder container and a powder transfer pipe connected to the powder container.
FIG. 3 is a cross-sectional view of a powder pump.
FIG. 4 is a cross-sectional view showing a state when cleaning a powder transfer path.
[Explanation of symbols]
2 Transfer device 3 Developing device 5 Pump
9 cases
15 Powder inlet tube 16 Open port 37 Container T Toner

Claims (2)

In the developer transfer device that transfers the powdery developer in the developer container to the uniaxial eccentric pump through the developer transfer path by the suction action of the suction type uniaxial eccentric pump,
The uniaxial eccentric pump includes a case that forms an outer shell thereof, and an upstream end in the developer transfer direction of the developer transfer path is detachably connected to the developer container, and a developer transfer direction of the developer transfer path The powder inlet pipe constituting the most downstream side is integrally connected to the case of the uniaxial eccentric pump , and the powder inlet pipe is provided with an opening for cleaning that can be opened and closed and communicates with the inside. A developer transfer device.   A developer transfer device according to claim 1, and a developing device that forms a toner image on the surface of the image carrier, and the powdered toner transferred by the developer transfer path is supplied to the developing device. An image forming apparatus.

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