JP2595567B2 - Developing machine toner supply device - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a toner supply device for a developing machine used in an electrophotographic image forming apparatus.

[Conventional technology]

In an electrophotographic color image forming apparatus, a plurality of developing machines are arranged around a photosensitive material in the apparatus main body. In this case, if a developing machine using a two-component developer is used, each developing machine is used. It is important to replenish toner to the machine.In many cases, a toner hopper is installed in front of the main body of the machine, because of the space inside the machine and the ease of toner replenishment by the operator. Supply.

On the other hand, some color toners have very poor fluidity due to the nature of the colorant, and it is very difficult to transport such toner.

Therefore, a toner replenishing device as shown in FIGS. 5 to 7 is conventionally known.

That is, the first and second developing units 2 and 3 are disposed opposite to the photosensitive material 1 and the first and second developing units 2 and 3 are connected to the housing 4.
A developing roll 5, a transport roll 6, a paddle 7, an unloading auger 8, and an unloading auger 9 are disposed therein.
And the carry-in auger 9 faces the blender 10 outside the housing 4, and a part of the developer in the housing 4 is carried out into the blender 10 by the carry-out auger 8 so as to supply the toner from the inlet 10 a of the blender 10. Then, the toner is mixed with the supplied toner, and is carried into the housing 4 again by the carry-in auger 9.

[Problems to be solved by the invention]

On the other hand, in order to reduce the size of the apparatus for cost reduction or to arrange a large number of developing machines for multi-functionality, it is necessary to reduce the size of the developing machine itself.

In this way, the developing machine itself is reduced in size, and the carry-out auger 8 and the carry-in auger 9 are provided and the housing 4 is provided.
When the developer inside the housing 4 is carried out to the front side of the housing 4, the carry-out direction of the developer by the carry-out auger 8 is orthogonal to the developer flow toward the developing roll 5 in the housing 4. When the flow traverses the carry-out auger 8, the flow is blocked by the carry-out auger 8, and finally the developer 11 is clogged as shown in FIG.

 This is more remarkable in the developing machine disposed on the upper side.

SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide a toner replenishing device for a developing machine in which a developer augment is prevented from being prevented by a carry-out auger in which a developer flow in a housing is stopped.

[Means and actions for solving the problems]

A developing roll 5 is provided near the opening of the housing 4, a conveying means for conveying the developer to the developing roll 5, and a carry-in auger 9. The carry-out auger 8 is provided between the developing roll 5 and the conveying means in the housing 4. Is provided so as to traverse the flow of the developer in the housing 4 to form a developing machine. The unloading auger 8 and the unloading auger 9 project outside from the side wall 4a of the housing 4 to face the blender 10 outside the housing 4. In the toner replenishing device of the developing machine, a shaft 14 for rotationally driving the unloading auger 8,
A spiral blade 15 attached near one axial end of the shaft 14 to transport the developer in the axial direction, and a spiral blade 15 attached to a portion of the shaft 14 other than the spiral blade 15 to transport the developer in a direction perpendicular to the axial direction. A developer feed plate 16, wherein the unloading auger 8 is mounted on the housing 4 so that the spiral blades 15 pass through the side wall 4 a of the housing 4 and face the interior of the blender 10. Is a toner supply device.

According to the present invention, a required amount of the developer is taken out from the housing 4 of the developing machine by the carry-out auger 8 and the blender 10 is taken out.
And the toner is mixed with the replenishment toner in the blender 10 and re-conveyed into the housing 4 by the carry-in auger 9, so that a sufficient conveying force can be obtained even with toner having poor fluidity.

The unloading auger 8 is provided with a spiral blade 15 near one end of the shaft 14 in the axial direction, and a developer feed plate 16 attached to the other portion of the shaft 14. The spiral blade 15 is connected to the blender 10.
Blender with the required amount of developer
Can be carried out to 10.

Moreover, the spiral blade 15 is a side wall in the housing 4.
4a, the developer feed plate 16 is located in the remaining portion of the housing 4 so that the housing 4 is transported toward the developing roll 5 by the developer transport means.
Most of the developer inside is transported toward the developing roll 5 by the developer feed plate 16, and the developer is not clogged at the unloading auger 8.

〔Example〕

An embodiment of the present invention will be described below with reference to FIGS. Note that the overall configuration of the developing machine is the same as that of the related art, and the description will be made with the same reference numerals.

FIG. 1 is a sectional view in the axial direction of the unloading auger portion. The unloading auger 8 has a rotating member 13 rotatably disposed along a substantially semicircular guide member 12.
Is attached to the side wall 4a of the housing 4, and the rotating member 13 has a shaft 14 on which a spiral blade 15 and a developer feed plate 16 are mounted.
The shaft 14 is disposed along the inside 12a, and the shaft 14 projects from a hole 17 formed in one side wall 4a of the housing 4 into the upper entrance space 10b of the blender box 10 so as to be rotatable on the upper portion 10c of the blender box 10. The spiral blade 15 is mounted on the hole 17 side and has a length 1 protruding inward from the side wall 4a, is significantly shorter than the entire length of the shaft 14, and slightly faces the developer drop region A. In addition, a developer feed plate 16 is attached to the remaining portion of the shaft 14 with screws 18, and the developer feed plate 16 is wider than the diameter of the shaft 14 and a guide member.
It rotates with respect to the twelve semicircular recesses 12a.

As a result, a part of the developer in the housing 4 is carried out to the blender box 10 by the spiral blade 15 of the carry-out auger 8, and most of the developer flow in the housing 4 is transferred to the developer feed plate 16. Since the developer is transported in the flow direction by the rotation, the developer flows smoothly in the housing 4 and the developer is not clogged at the unloading auger 8.

That is, since the carry-out auger 8 only needs to be able to carry out a part of the developer in the housing 4 to the blender box 10, the helical blade 15 for providing the developer with a conveying force is provided on one side wall.
The length is several tens of millimeters from 4a, and a developer feed plate 16 is attached to the remaining portion.

This makes it possible to obtain a small-sized developing machine free from developer clogging while ensuring good transportability even when toner having poor fluidity is used.

 Next, a specific example will be described.

By multiplying the amount of toner consumed in one development by a safety factor by an image forming apparatus that outputs 15 images of the maximum A3 size per minute, the toner carry-in amount is set to 200 mg / sec. Each value was set.

That is, when a toner dispensing signal is input from the process control system, the toner is carried into the housing 4 at 200 mg per second. This is the toner carry-in amount that follows even if 40% of the A3-size paper is solid.

First, the toner feed speed (the feed speed of the auger that transports the toner from the toner hopper to the blender box)
Was 7.5 cm / sec, assuming that the toner dropped at the end of a certain development cycle was completely absorbed into the developer housing during the next development cycle.

Next, the amount of developer required for 200 mg of the toner to be mixed satisfactorily was determined experimentally in the stirring chamber of the developing machine shown in FIG. 1 to be about 10 g.

As a result, the unloading auger 8 needs to unload the developer at 10 g / sec.

On the other hand, the amount of the developer falling from the developing roll is determined by the image quality parameter, and although there is a slight difference for each color,
200 g to 300 g, and the diameter of the shaft 14 is 6
^φ , the rotation speed of 180 rpm was sufficient when the width of the developer feed plate 16 was 12 mm.

The developer discharge amount was experimentally obtained by changing the pitch and the protrusion length l of the spiral blade 15 of the discharge auger 8 under the above conditions.

The results are as shown in the chart of FIG. 4, and it is 10 g / se at 12 pitches, 24 pitches and 18 pitches if the projection length 1 is approximately 20 mm.
The developer discharge amount of c was obtained.

If the number of revolutions of the carry-out auger 8 is limited due to driving reasons or the like, increasing the number of spiral blades can provide a necessary amount of developer carry-out.

〔The invention's effect〕

A necessary amount of developer is taken out of the housing 4 of the developing machine by the carry-out auger 8, sent to the blender 10, mixed with the replenishment toner in the blender 10, and again carried in to the carry-in auger 9.
Therefore, a sufficient conveying force can be obtained even with toner having poor fluidity.

The unloading auger 8 is provided with a spiral blade 15 near one end of the shaft 14 in the axial direction, and a developer feed plate 16 attached to the other portion of the shaft 14. The spiral blade 15 is connected to the blender 10.
Blender with the required amount of developer
Can be carried out to 10.

Moreover, the spiral blade 15 is a side wall in the housing 4.
4a, the developer feed plate 16 is located in the remaining portion of the housing 4 so that the housing 4 is transported toward the developing roll 5 by the developer transport means.
Most of the developer inside is transported toward the developing roll 5 by the developer feed plate 16, and the developer is not clogged at the unloading auger 8.

[Brief description of the drawings]

1, 2 and 3 show an embodiment of the present invention.
The figure is a cross-sectional view of the unloading auger part, FIGS. 2 and 3 are front views and side views of the shaft and the developer feed plate, and FIG. FIG. 5 is a sectional view of a conventional example, FIGS. 6 and 7 are a front view, a side view, and FIG. 8 of a developing machine. 4 is a housing, 8 is a carry-out auger, 14 is a shaft, 15 is a spiral blade, and 16 is a developer feed plate.

Claims (1)

(57) [Claims] A developing roller provided near an opening of the housing;
Conveying means for conveying the developer to the developing roll 5;
A carry-in auger 9 is provided, and a carry-out auger 8 is provided between the developing roll 5 in the housing 4 and the conveying means so as to cross the flow of the developer in the housing 4 to form a developing machine. Hanging Auger 9 4
And a shaft 14 for rotating the unloading auger 8 and a shaft 14 for rotating the unloading auger 8.
A spiral blade 15 attached near one end in the axial direction to transport the developer in the axial direction; and a developing device attached to a portion of the shaft 14 other than the spiral blade 15 to transport the developer in the direction perpendicular to the axial direction. A delivery auger 8 for the housing 4 and a spiral blade for the delivery auger 8.
15. A toner replenishing device for a developing machine, wherein 15 is mounted so as to penetrate the side wall 4a of the housing 4 and face the inside of the blender 10.