JP3985472B2 - Developer transport device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a developer conveying device that conveys a powdery developer.
[0002]
[Prior art]
In an image forming apparatus represented by a printer, a copying machine, a facsimile machine, a multifunction machine, etc. using a dry electrophotographic system, a desired developer is developed by developing an electrostatic latent image using a powdery developer. In some cases, an image is formed, and a developer conveying device is used that conveys the developer from a part on the sending side to a part on the receiving side via a developer conveying pipe.
[0003]
As this type of developer transport device, for example, a developer storage pipe that connects a developer storage section that stores a replenishment developer and a developer device that receives the developer is connected by a developer transport pipe. A developer feeding member (hereinafter also simply referred to as a “coiled auger”) in which a wire such as a metal material is spirally wound inside is rotated to feed the developer, and the developer fed by the coiled auger There is a type in which the toner is finally naturally discharged from a discharge port formed on the lower surface side of the tip of the developer conveying pipe connected to the developing device side.
[0004]
[Problems to be solved by the invention]
By the way, in such a developer conveying device, when trying to reduce the size (such as reducing the diameter of the developer conveying pipe) in response to the size reduction of the main body of the image forming apparatus, the developer receiving side particularly The developer is easily clogged at the discharge port at the tip of the developer transport pipe connected to the developing device.
[0005]
As illustrated in FIG. 6, this clogging is caused by connecting the winding terminal portion 125, which is a free end of the coiled auger 120 of the developer transport pipe 100 in the conventional developer transport apparatus, to the developing device side of the pipe 100. 7 is provided so as to rotate in a state of being separated from the abutting end surface 105 in the vicinity of the discharge port 103 of the leading end portion, and as illustrated in FIG. 7, the winding end portion 125 of the coiled auger 120 and the conveying pipe The developer 130 easily adheres to the inner wall surface of the pipe tip portion that becomes a gap with the end surface 105 at the end of contact. The fixed developer 130a gradually grows and finally grows up to the state of closing the discharge port 104. It is caused by.
[0006]
Further, as shown in FIG. 7B, the growth of the fixed developer 130a is caused by the fact that the winding end portion 125 side of the coiled auger 120 is pushed and contracted gradually by the influence of the growing fixed developer 130a. May be encouraged. Further, when the developer transport device is used for a long time, the auger 120 is slightly shrunk or elastically deformed due to friction generated between the coiled auger 120 and the inner wall surface of the developer transport pipe 100. In the transport pipe made of the elastic pipe to be obtained, the pipe may be slightly extended, and the gap between the winding end portion 125 and the end portion 105 of the transport pipe abuts due to the phenomenon of the auger contraction or the elastic hype extension. In some cases, it may be promoted. Such clogging of the developer becomes more prominent particularly as the inner diameter of the developer transport pipe becomes smaller.
[0007]
Incidentally, in Japanese Patent Laid-Open No. 11-24524, there is technically provided with vibration means for vibrating at least a part of the toner conveyance path in order to prevent toner clogging (blocking) in the toner conveyance path having conveyance means such as an auger. Means are shown. However, in this case, there is a problem that noise is generated due to vibration of the toner conveyance path, and a problem that the cost is increased by adding a new means such as the vibration means.
[0008]
The present invention has been made to solve the above-described problems, and the main object of the present invention is to provide a discharge port at the tip of the developer transport pipe without causing noise or increasing costs. It is an object of the present invention to provide a developer transport device that can easily prevent clogging of the developer.
[0009]
[Means for Solving the Problems]
In the developer transport device of the present invention, a developer transport pipe is connected between the powder developer delivery side and the developer receiving side, and a wire is wound spirally in the developer transport pipe. The developer feeding member is rotated to feed the developer, and the developer fed by the developer feeding member is connected to the developer receiving side from a discharge port formed on the lower surface side of the tip of the developer transport pipe. In the developer conveying device that spontaneously drops and discharges, the winding end portion of the developer feeding member is rotated in a state of being pressed against the abutting end surface of the leading end portion of the developer conveying pipe. .
[0010]
Here, the winding end portion of the developer feeding member rotates the feeding member in the direction opposite to the winding direction (for example, when the winding is right-handed, it rotates to the left). Part) may be left as it is (there is no risk that the cut will be caught on the abutting surface). If necessary, an end turn may be formed at the end of the turn. As the developer transport pipe, it is possible to use a hard pipe made of a metal material, a plastic material, or the like, but in order to reduce the size of the apparatus, it is necessary to use a flexible elastic pipe that can be elastically deformed. The degree of freedom increases and is advantageous. This transport device is particularly effective when a relatively small diameter developer transport pipe having an inner diameter of the pipe (transport path) of 15 mmφ or less is used.
[0011]
According to such a developer transport apparatus of the present invention, the winding end portion of the developer feeding member rotates in a state of being pressed against the abutting end surface of the tip end portion of the developer transport pipe, and therefore, the winding end portion and the abutting portion are contacted. There is no unnecessary gap between the developer and the developer, which is difficult to fix. As a result, there is no possibility that the fixed developer grows with time and blocks the discharge port at the front end of the transport pipe, and clogging of the developer at the discharge port is less likely to occur.
[0012]
Further, in such a developer conveying device, the amount of pressure contact at the winding end portion of the developer feeding member is generated when the developer feeding member rotates for a time corresponding to the service life on the developer receiving side. It may be set to the predicted shrinkage amount of the developer feeding member. The amount of pressure contact corresponds to the difference between the dimension in a natural state where the winding end portion is not pressure-contacted and the dimension in a state of pressure contact.
[0013]
In this case, even if the developer feeding member starts to shrink and shrink over time, the winding terminal portion of the developer feeding member continues to come into pressure contact with the abutting surface of the leading end of the transport pipe. Developer clogging is less likely to occur. The predicted shrinkage amount of the developer feeding member is set as a completely predicted value, or when the feeding member is rotated on a trial basis for a time corresponding to the service life on the developer receiving side. What is necessary is just to set with reference to what measured the amount of shrinkage.
[0014]
Furthermore, in such a developer transport apparatus, the opening dimension in the developer feed direction of the discharge port at the tip of the developer transport pipe is set to a length that is at least 1.5 times the winding pitch of the developer feed member. Good.
[0015]
In this case, when the developer feeding member rotates once, the developer is fed by one pitch of the winding pitch by the developer feeding member and moves, so that it is easy to be discharged at the discharge port and is fixed near the discharge port. It becomes difficult to do. Thereby, clogging of the developer at the discharge port is less likely to occur. In addition, although the upper limit of the said opening dimension of this discharge port can be set suitably, it is preferable to set it as about 4 pitches of a winding pitch, for example.
[0016]
In such a developer transport device, when the developer transport pipe is a flexible elastic pipe that can be elastically deformed, the developer feed member determines the pressure contact amount of the winding end portion of the developer feed member. It is good to set it to the predicted amount of elongation of the elastic pipe that occurs when it rotates for a time corresponding to the service life on the receiving side.
[0017]
In this case, even when the developer transport pipe as the developer transport pipe starts to grow with time, the winding end portion of the developer feeding member continues to be in pressure contact with the abutting surface of the front end of the transport pipe. In addition, clogging of the developer at the discharge port is less likely to occur. The predicted amount of elastic pipe elongation is set as a completely predicted value, or the amount of contraction of the elastic pipe when the feed member is experimentally rotated for a time corresponding to the service life on the developer receiving side. This can be set with reference to the measured values.
[0018]
When the developer transport pipe is the above elastic pipe, a layer made of a low friction material (polyethylene, fluorine resin, etc.) having a lower frictional resistance (dynamic friction coefficient) than the pipe base material on the inner wall surface of the elastic pipe. It is good to form.
[0019]
In this case, it becomes difficult for the developer to adhere to the inner wall surface of the transport pipe. Further, since the winding end portion of the developer feeding member is rotated in a state where it is in pressure contact with the end surface of the end of the developer conveying pipe, the developer feeding member contacts the inner wall surface of the conveying pipe and rotates. Although the frictional resistance is often increased, the frictional resistance is lowered because the inner wall surface is formed of a coating layer of a low friction material, and the developer feeding member rotates well without impairing its rotation. It becomes like this. As a result, the developer is favorably fed by the developer feeding member in the transport pipe. This makes it difficult for the developer to adhere to the inner wall surface of the transport pipe, so that clogging of the developer at the discharge port is less likely to occur.
[0020]
Furthermore, when the developer transport pipe is the elastic pipe, the curvature of the bent portion of the elastic pipe is preferably R40 mm or more.
[0021]
In this case, when the developer feeding member is made of a metal material, the metal developer feeding member is deformed in the elastic region at the bent portion of the elastic pipe, thereby preventing the progress of metal fatigue and damage due to metal fatigue. Can do. As a result, the developer feeding by the developer feeding member is favorably performed. Therefore, this also makes it difficult for the developer to be fixed due to poor conveyance at the lead-bending portion of the conveyance pipe, and therefore clogging of the developer at the discharge port is less likely to occur.
[0022]
The developer conveying device of the present invention may be any device as long as it conveys the powdery developer by the developer conveying pipe having the developer feeding member and the discharge port as described above. For example, this developing and conveying apparatus can be used as a developer replenishing apparatus that conveys the developer in the developer container to the developing apparatus, or can be used as a developer collecting apparatus that conveys the discarded developer to the developer collecting container. Can do.
[0023]
DETAILED DESCRIPTION OF THE INVENTION
1 and 2 show a developer replenishing apparatus to which the present invention is applied. FIG. 1 is a schematic diagram showing the overall configuration, and FIG. 2 is a perspective view of an essential part thereof.
[0024]
This developer replenishing device 1 is used for transporting and replenishing a replenishing toner (developer) contained in a cylindrical toner bottle 10 to a developing device 20 in an image forming apparatus such as an electrophotographic printer. It is a device. The developer replenishing device 1 basically holds the toner bottle 10 in a detachable manner and temporarily stores the toner in the toner bottle 10, the holder 30 and the developing device 20. A toner conveying pipe 40 arranged so as to connect between them, a screw-type auger 35 for feeding the toner stored in the holder 30 to the toner conveying pipe 40 side, and the auger 35 for feeding the toner into the toner conveying pipe 40 The main part is composed of a coiled auger 50 that conveys the toner to be developed toward the developing device 20 and a rotation driving device 60 that rotates the screw-shaped auger 35, the coiled auger 50, and the like.
[0025]
The holder 30 includes a holder main body portion 31 having a substantially semi-cylindrical shape that holds the lower half of the cylindrical toner bottle 10, and a toner storage portion 32 formed so as to protrude downward from the holder main body portion 31. And is formed. The toner storage unit 32 is provided with a toner detection sensor 33 that detects whether or not there is toner that is discharged and stored from the toner bottle 10. The screw auger 35 has a shape in which a toner feed blade is spirally wound around a rotation shaft, and is rotatably attached to the bottom of the toner storage unit 32.
[0026]
The toner conveying pipe 40 is a flexible plastic elastic pipe that has a circular passage space having a pipe inner diameter slightly larger than the winding diameter of the coiled auger 50 and can be elastically deformed. Is connected to the toner delivery port 32 a of the storage portion 32 of the holder 30, and the other end is connected to the toner receiving port (28) of the developing device 20 via the connection nozzle 43.
[0027]
The coiled auger 50 is formed by winding a metal wire in a spiral shape at a predetermined pitch with a winding diameter smaller than the inner diameter of the toner transport pipe 40 so that the coil auger 50 can be inserted into the toner transport pipe 40 and rotated. Is. Further, one end portion (winding start portion) of the coil-shaped auger 50 is connected to the tip end portion of the rotating shaft of the screw-shaped auger 35, and rotates simultaneously with the rotation of the auger 35. . In addition, the other end portion (winding end portion) of the coiled auger 50 is a free end and is rotated while being inserted also into the connection nozzle 43.
[0028]
The rotary drive device 60 transmits the rotational power of the drive motor 61 to the screw-type auger 35 via a predetermined reduction gear train 62, rotates the auger 35, and also has a coil-shaped auger 50 connected to the auger 35. It is designed to rotate at the same time.
[0029]
As shown in FIGS. 2 and 4 to 5, the nozzle 43 for connection in the toner transport pipe 40 is inserted with the nozzle tip 45 and the toner transport pipe 40 having a rectangular shape in which a toner discharge port 44 is formed. The outer appearance is mainly composed of a nozzle body composed of a cylindrical nozzle rear end portion 46 and a slide shutter 47 that slides at the nozzle front end portion 45 to open and close the discharge port 44.
[0030]
Among these, the nozzle tip 45 is formed with a passage space having a rectangular cross section in which a coiled auger 50 can be inserted and rotated, and a toner discharge port 44 is formed on the lower surface on the tip side. (Figure 5b). The nozzle rear end portion 46 has a circular passage space in which a coiled auger 50 is inserted and can be rotated (FIG. 5b). The slide shutter 47 is a quadrangular hollow frame that is fitted on the outside of the nozzle tip 45 and is slidably attached. The slide shutter 47 is formed on the abutting portion 47a and the nozzle tip 45 that are formed to protrude on the lower surface thereof. It is elastically biased toward the nozzle tip side by a spring 48 attached between the flange portion 45a. In FIG. 4, reference numeral 45 b denotes a locking projection that prevents the shutter 47 from coming off from the nozzle tip 45 by entering and locking the locking groove 47 b of the slide shutter 47, and 45 c denotes the rear end of the spring 48. It is a support pin inserted and supported.
[0031]
The abutting portion 47a of the slide shutter 47 has an external shape that abuts against the abutting portion 29 formed in the vicinity of the toner receiving port (28) of the developing device 20, while the inside thereof is hollow. In the inner space, the tip of the spring 48 is accommodated and supported. As a result, when the connecting nozzle 43 is inserted into or removed from the toner receiving port (28), the toner discharge port 44 of the nozzle tip 45 is opened and closed by the slide shutter 47, so that the toner receiving port ( 28) can be detachably connected.
[0032]
As shown in FIG. 2, the toner bottle 10 includes a cylindrical bottle body 12 in which a toner discharge port 13 is formed on a lower surface on one end side, and lid bodies 14 that block openings at both ends of the bottle body 12. , 15 and an agitator 16 that is rotatably supported by the lids 14 and 15 and rotates to convey the toner T toward the discharge port 13 inside the bottle body 12 (in this example, the rotation support 16a A film 16b that is in contact with the inner surface of the bottle is attached to the tip. The agitator 16 rotates when the gear 17 attached to one end thereof meshes with a part of the reduction gear train 62 of the rotational drive device 60 and the rotational drive force of the drive motor 56 is transmitted. .
[0033]
As shown in FIGS. 1 and 3, the developing device 20 is a two-component developing device that performs magnetic brush contact-type development using a two-component developer composed of toner (T) and a carrier. A developing roll 22, a paddle-shaped developer supply member 23, developer agitating and conveying members 24 and 25 made of a screw-shaped auger, a roll-shaped layer thickness regulating member 26, and the like are arranged in a housing 21 having a form containing a developer containing portion 20b. It has a configuration. A toner replenishing portion 27 is also formed at one end portion of the housing 21 so as to extend the developer agitating and conveying members 24 and 25 continuously with the developer containing portion 20b. A toner receiving port 28 with an openable / closable door into which the connection nozzle 43 in the toner transport pipe 40 of the developer supply device 1 is inserted is formed. In FIG. 1, reference numeral 2 denotes an image carrier such as a photosensitive drum on which an electrostatic latent image is formed.
[0034]
In the developer replenishing device 1 according to this embodiment, as the toner transport pipe 40, a polyethylene low friction material is applied to the inner wall surface of the pipe base material made of polyurethane when the pipe base material is extruded, and the inner surface of the pipe base material is extruded. An elastic pipe having an inner diameter of about 7 mm formed by simultaneously extruding to the side was used. As the coiled auger 50, a stainless steel wire having a rectangular cross section of 1 mm × 0.5 mm is spirally formed so that the winding diameter (outer diameter) is about 6 mm and the winding pitch P is 6 to 8 mm (dotted arrow in FIG. 5b). A rolled metal auger was used (with a right-hand turn indicated by M). This metal auger 50 was used by rotating in the left direction indicated by the solid arrow A in FIG.
[0035]
Further, in this developer replenishing device 1, as shown in FIG. 5, the winding end portion 51 of the coiled auger 50 is left in a state where the end of winding is left as it is, and the end of the tip of the toner transport pipe 40 is abutted. The end surface 40a, that is, the end of the connection nozzle 43 is abutted against the end surface 45d and is installed so as to be rotated in a pressed state. Regarding the pressure contact amount α of the winding end portion 51 of the auger 50, the service life of the developing device 20 or an image forming apparatus using the developing device 20 (for example, the image forming operation time on 300k sheets of A4 size recording paper, The estimated amount of shrinkage of the coiled auger 50 that occurs when it is rotated for a time corresponding to an average use time of 5 years, etc., is the time required for the image forming operation on 500 k sheets of A4 size recording paper. The amount of shrinkage when the toner rotation idling test is actually performed is set based on data obtained by actual measurement. In this embodiment, the pressure contact amount α is set to about 2 mm, but in general, it may be set within a range of 0 <α ≦ 5 mm.
[0036]
Further, in the developer replenishing device 1, as shown in FIG. 5, the opening dimension L of the toner discharge port 44 in the toner feeding direction H is 1.5 to 1.8 times the winding pitch P of the coiled auger 50. Set to double length.
[0037]
In addition, the developer replenishing device 1 is installed in a state where its constituent parts are closely packed in order to reduce the size of the main body of the image forming apparatus to be used. From the viewpoint of efficiently connecting between the holder 30 for mounting the bottle 10 and the developing device 20 without using an extra space, the part 40b of the transport pipe 40 is drawn in a bent state. (Figs. 1-3). At this time, the curvature of the lead bent portion 40b of the toner transport pipe 40 is set in a range of R40 to 60 mm.
[0038]
Next, the operation of the developer supply device 1 having such a configuration will be described.
[0039]
First, the developer replenishing device 1 is attached by inserting the connection nozzle 43 of the toner transport pipe 40 into the toner receiving port 28 in the toner replenishing portion 27 of the developing device 20. By inserting the connection nozzle 43 into the toner receiving port 28, as shown in FIG. 4B, the abutting portion 47a of the slide shutter 47 abuts against the abutted portion 29 on the receiving port 28 side. Moving to the rear side of the tip 45, the toner discharge port 44 on the lower surface of the nozzle tip 45 is opened. On the other hand, the toner bottle 10 is attached to the holder 30. As a result, the developer supply device 1 is ready for use.
[0040]
Then, when the toner of the two-component developer in the housing 20 of the developing device 20 is consumed and reduced by the development, the developer replenishing device 1 starts at a predetermined timing and replenishes the toner (for example, at the consumed amount). Start supplying a corresponding amount of toner).
[0041]
That is, when the toner is replenished, the drive motor 61 of the rotation driving device 60 is started, whereby the agitator 16 of the toner bottle 10 is rotated and the toner T in the bottle body 13 is transferred from the toner discharge port 12 to the storage portion of the holder 30. Drop to 31. At the same time, the screw-type auger 35 rotates to send the toner in the storage unit 31 toward the toner transport pipe 40. In the toner transport pipe 40, the coiled auger 50 rotates as the screw-shaped auger 35 rotates. As a result, the toner fed from the storage unit 31 is fed through the transport pipe 40 by the auger 50 and is transported to the connection nozzle 43.
[0042]
The toner thus transported to the connection nozzle 43 naturally falls from the discharge port 44 so as to be finally pushed out by the coiled auger 50, and is replenished to the toner replenishing portion 29 (developer containing portion 20b) of the developing device 20. Is done.
[0043]
When the toner is replenished, as shown in FIG. 5a, the winding end portion 51 of the coiled auger 50 rotates in a state of being pressed against the abutting surface 45d of the connection nozzle 43. There is no unnecessary gap between the nozzle 45d and the toner hardly adheres to the inner wall surface of the nozzle tip 45. For this reason, there is no possibility that the toner fixed to the inner wall surface grows with time as described in the prior art and blocks the toner discharge port 44 (see FIG. 7), and the toner is clogged at the discharge port 44. It rarely occurs.
[0044]
Even if the connection nozzle 43 of the toner transport pipe 40 is removed from the toner receiving port 28 of the developing device 20 and left for a while, the toner is fixed even if the toner is fixed to the inner wall surface of the nozzle tip 45. The toner is written off by the coiled auger 50 that rotates while being pressed against the abutting surface 45 d of the connection nozzle 43. This also makes it difficult for toner to be clogged at the discharge port 44 of the nozzle tip 45.
[0045]
Further, by using the developer replenishing device 1 for a long time, even if the coiled auger 50 starts to shrink and shrink over time, the winding end 51 of the auger 50 is pressed against the contact surface of the front end of the transport pipe. Keep doing. For this reason, it is difficult for toner to adhere to the inner wall surface of the nozzle tip 45 and toner clogging at the discharge port 44 is unlikely to occur.
[0046]
Furthermore, since the opening dimension L of the toner discharge port 44 in the toner feeding direction is set to at least 1.5 times the winding pitch P of the coiled auger 50, the coiled auger 50 rotates once. The toner is always fed by the auger 50 by one winding pitch and moved. For this reason, it is easy to be discharged at the discharge port, and it is difficult to stick around the discharge port, which also makes it difficult for toner to be clogged at the discharge port 44.
[0047]
In addition, since the low friction material is applied to the inner wall surface of the toner transport pipe 40, the toner is less likely to adhere to the inner wall surface. In addition, the frictional resistance between the inner wall surface and the coiled auger 50 is reduced, and the rotation of the auger 50 is not impaired, so that the toner is transported satisfactorily. This also makes it difficult for toner clogging at the discharge port 44 to occur.
[0048]
Further, since the curvature R of the lead bent portion 40b of the toner transport pipe 40 is set to at least 40 mm or more, the metal coiled auger 50 is only deformed in the elastic region at the lead bent portion 40b. It is possible to prevent the metal fatigue of the auger 50 from progressing or being damaged by the metal fatigue. As a result, good toner feeding by the coiled auger 50 is stably performed over a long period of time, and the toner does not adhere to the lead-bending portion 40b of the transport pipe 40 or the like.
[0049]
In this embodiment, as the toner transport pipe 40, the type in which the connection nozzle 43 is coupled to the tip thereof is exemplified. However, in the present invention, there is no connection nozzle 43 and the tip of the pipe 40 itself. Part as it is, The pa It is also possible to use a type of transport pipe that forms a discharge port 44 or the like at the tip of the pipe.
[0050]
The coiled auger 50 was made of a stainless steel wire having a rectangular cross section and could be used for a long time without being damaged during use. According to the present inventor, Instead, when a coiled auger formed of the same configuration with a stainless steel wire having a circular cross section (for example, a diameter of 1 mm) is used in the same specification environment, it can be folded in the vicinity of the lead bending portion 40b in a short period of time. It has been confirmed that it becomes unusable.
[0051]
In the developer replenishing device 1, unnecessary fixing of toner is unlikely to occur in the toner transport pipe 40 including the connection nozzle 40, so that the fixed toner lump is not replenished to the developing device 20. For this reason, for example, there is no possibility that the development device 20 and the image quality defect are induced by supplying the fixed toner mass to the developing device 20.
[0052]
【The invention's effect】
As described above, according to the developer conveying device of the present invention, the developer clogging of the developer at the discharge port at the tip of the developer conveying pipe can be achieved without causing noise or increasing costs due to the above-described configuration. Can be prevented relatively easily.
[Brief description of the drawings]
FIG. 1 is a schematic diagram illustrating an overall configuration of a developer supply device as a developer transport device according to an embodiment.
FIG. 2 is a perspective view showing a developer supply device and a toner bottle.
3A is a cross-sectional explanatory view of the developer supply device, and FIG. 3B is a cross-sectional view taken along the line QQ in FIG. 3A.
4A and 4B show a toner conveying pipe and a connection nozzle, where FIG. 4A is a partial cross-sectional explanatory view showing a state when the toner is not connected, and FIG. 4B is a partial cross-sectional explanatory view showing a state when the connection is made; .
5A is a cross-sectional view mainly showing a nozzle body of a connection nozzle, and FIG. 5B is a cross-sectional view taken along line BB in FIG. 5A.
FIG. 6 is a cross-sectional explanatory view of main parts showing a configuration example of a conventional developer conveying pipe and a developer feeding member.
FIG. 7 is an explanatory cross-sectional view illustrating a process of generating a developer clogging phenomenon that occurs at a developer discharge port of a conventional developer transport pipe.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Developer supply apparatus (developer conveyance apparatus), 10 ... Toner bottle (developer delivery side), 20 ... Development apparatus (developer reception side), 40 ... Toner conveyance pipe, 40d ... Leading bending part, 44 ... discharge port, 45d (40a) ... abutting surface, 50 ... coiled auger (developer feed member), 51 ... winding end, T ... toner (developer), L ... opening size, P ... winding pitch, H ... Toner feed direction.

Claims (1)

A state in which a part of the pipe is bent and drawn by a developer transport pipe that can be elastically deformed between the developer container on the powder developer delivery side and the developing device on the developer receiving side. The developer feeding member formed by spirally winding the wire in the developer transport pipe is rotated while the developer feeding member is elastically deformed by the bent portion of the developer transport pipe and the developer is fed. In the developer transport device that drops and discharges the developer fed by the developer feeding member from the discharge port formed on the lower surface side of the tip of the developer transport pipe connected to the developer receiving side,
While rotating the winding end portion of the developer feed member in a state of being pressed against the end surface of the end of the developer transport pipe ,
An opening dimension in the developer feeding direction of the discharge port of the developer conveying pipe is set to a length of 1.5 times or more of a winding pitch of the developer feeding member in a state of being pressed against the abutting end surface. Developer transport device.

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