JP2023174516A - Powder conveying device and image forming apparatus - Google Patents

Abstract

To reduce the likelihood of the occurrence of a trouble that a floating member gets out from an inflow port of a fall conveyance path.SOLUTION: A powder conveying device is provided with: a fall conveyance path 41 through which waste toner (powder) flowing in from an inflow port 41a falls by its own weight; an intersection conveyance path 42 that is in communication with a lower end of the fall conveyance path 41 and extends in an intersection direction intersecting the fall conveyance path 41; a conveying screw 43 that is provided in the intersection conveyance path 42 and rotates in a predetermined direction to convey the waste toner in the intersection direction; and a floating member 45 that is installed floatable inside the fall conveyance path 41 and brought into contact with the conveying screw 43 rotating in the predetermined direction to float in the fall conveyance path 41. The inflow port 41a and the floating member 45 are configured to be able to interfere with each other so that the floating member 45 does not get out from the inflow port 41a of the fall conveyance path 41.SELECTED DRAWING: Figure 3

Description

The present invention relates to a powder conveying device that conveys powder such as waste toner, and an image forming apparatus including a copying machine, a printer, a facsimile machine, or a multifunctional device thereof.

Conventionally, in image forming apparatuses such as copiers and printers, there have been two transport paths for transporting powder such as waste toner: a fall transport path in which the powder that flows in from the inlet falls under its own weight, and a fall transport path in which the powder that flows in from the fall transport path falls. A device is known that is provided with a cross-conveyance path in which the body is conveyed in the cross-direction by rotationally driving a conveyance screw (see, for example, Patent Document 1).

In Patent Document 1, in order to prevent waste toner from adhering to the inner wall surface of the falling conveyance path, a pillar-shaped floating member is installed in the falling conveyance path, and the floating member is attached to the rotating conveyance screw. A technique has been disclosed in which the floating member is brought into contact with the movable member to cause the floating member to collide with the inner wall surface of the falling conveyance path.

In the technology of Patent Document 1, when powder (waste toner) in the falling conveyance path is sucked and cleaned from the inlet during maintenance, etc., the floating member slips out of the inlet of the falling conveyance path, Problems such as parts being lost occurred.

The present invention was made in order to solve the above-mentioned problems, and provides a powder conveying device and an image forming device in which the problem of the floating member slipping out from the inlet of the falling conveying path is less likely to occur. There is a particular thing.

The powder conveyance device according to the present invention includes a falling conveyance path through which the powder flowing in from an inlet falls under its own weight, and a falling conveyance path that communicates with the lower end of the falling conveyance path and extends in a cross direction intersecting the falling conveyance path. a conveyance screw that is installed in the cross conveyance path and rotates in a predetermined direction to convey the powder in the cross direction; and a conveyance screw that is movably installed inside the drop conveyance path, a floating member that moves freely within the drop conveyance path due to contact with the conveyance screw rotating in the predetermined direction, and a movable member that moves freely within the drop conveyance path by contact with the conveyance screw that rotates in the predetermined direction; The movable member is configured to be able to interfere with the movable member.

According to the present invention, it is possible to provide a powder conveyance device and an image forming apparatus in which the problem of a floating member slipping out from an inlet of a falling conveyance path is unlikely to occur.

1 is an overall configuration diagram showing an image forming apparatus in an embodiment of the present invention. FIG. 3 is a configuration diagram showing an image forming section. FIG. 2 is a cross-sectional view showing the main parts of the waste toner conveying device. They are a top view and a side sectional view showing a floating member. FIG. 4 is a view of the inlet of the falling conveyance path and the floating member as seen from the direction A in FIG. 3; FIG. 3 is a cross-sectional view showing the main parts of the waste toner conveying device in which a cleaning device is installed. FIG. 7 is a cross-sectional view showing a main part of a waste toner conveying device in which a cleaning device is installed as Modification 1; FIG. 7 is a sectional view showing a main part of a waste toner conveying device in a state where a cleaning device is installed as a second modification. FIG. 7 is a cross-sectional view showing a main part of a waste toner conveying device in which a cleaning device is installed as a third modification. (A) A cross-sectional view showing the main parts of the waste toner conveyance device with the cleaning device installed, and (B) A view of the floating member viewed from the inlet side of the falling conveyance path, as Modification 4. be. FIG. 7 is a diagram showing a waste toner conveying device and a developing device as a fifth modification.

Hereinafter, embodiments for carrying out the present invention will be described in detail with reference to the drawings. In each figure, the same or corresponding parts are denoted by the same reference numerals, and repeated explanations thereof will be simplified or omitted as appropriate.

First, referring to FIG. 1, the overall configuration and operation of the image forming apparatus 1 will be described.
In FIG. 1, 1 is a color copying machine as an image forming device, 3 is a document conveyance unit that conveys a document to a document reading unit 4, 4 is a document reading unit that reads image information of the document, and 6 is a color copying machine based on input image information. A writing section (exposure section) that emits laser light is shown.
Further, 7 is a paper feeder in which sheets P such as paper are stored, 10Y, 10M, 10C, and 10BK are process cartridges as image forming units corresponding to each color (yellow, magenta, cyan, black), and 17 is a multi-color An intermediate transfer belt (image carrier) onto which the toner images are transferred in a superimposed manner; 18 represents a secondary transfer roller that transfers the toner image formed on the intermediate transfer belt 17 onto the sheet P;
Further, 20 is a fixing device that fixes the unfixed image on the sheet P, 28 is a toner container for replenishing toner of each color to the developing device of each process cartridge 10Y, 10M, 10C, and 10BK, and 30 is a waste toner that is collected. A waste toner collection container is shown.

Here, each of the process cartridges 10Y, 10M, 10C, and 10BK (image forming section) is one in which a photosensitive drum 11 as an image carrier, a charging device 12, a developing device 13, and a cleaning device 15 are integrated. Yes (see Figure 2). Each of the process cartridges 10Y, 10M, 10C, and 10BK is replaced with a new one when it reaches the end of its life.
Toner images of respective colors (yellow, magenta, cyan, and black) are formed on the photosensitive drums 11 (image carriers) in each of the process cartridges 10Y, 10M, 10C, and 10BK.

The operation of the image forming apparatus during normal color image formation will be described below.
First, the document is conveyed from the document table by the conveyance rollers of the document conveyance section 3 and placed on the contact glass of the document reading section 4 . Then, the image information of the document placed on the contact glass is optically read by the document reading section 4.
Then, the image information of each color of yellow, magenta, cyan, and black is transmitted to the writing section 6. Laser light (exposure light) based on the image information of each color is emitted from the writing section 6 onto the photoreceptor drums 11 of the corresponding process cartridges 10Y, 10M, 10C, and 10BK, respectively.

On the other hand, the four photosensitive drums 11 are rotating clockwise in FIGS. 1 and 2, respectively. Referring to FIG. 2, first, the surface of the photosensitive drum 11 is uniformly charged at a position facing the charging device 12 (charging roller) (this is a charging process). In this way, a charged potential is formed on the photoreceptor drum 11. Thereafter, the charged surface of the photosensitive drum 11 reaches the irradiation position of each laser beam.
In the writing section 6, laser beams L corresponding to image signals are emitted from a light source in correspondence to each color. The laser beam L is incident on the polygon mirror, reflected, and then transmitted through a plurality of lenses. After passing through the plurality of lenses, the laser light passes through different optical paths for each color component of yellow, magenta, cyan, and black (this is an exposure process).

Laser light corresponding to the yellow component is irradiated onto the surface of the photosensitive drum 11 of the first process cartridge 10Y from the left side of the paper. In this way, an electrostatic latent image corresponding to the yellow component is formed on the photosensitive drum 11 after being charged by the charging roller 12a.
Similarly, the cyan component laser light is irradiated onto the surface of the photosensitive drum 11 of the second process cartridge 10C from the left in the paper, and an electrostatic latent image of the cyan component is formed. The laser beam corresponding to the magenta component is irradiated onto the surface of the photoreceptor drum 11 of the third process cartridge 10M from the left in the paper, and an electrostatic latent image corresponding to the magenta component is formed. The black component laser light is irradiated onto the surface of the photosensitive drum 11 of the fourth process cartridge 10BK from the left in the paper, and an electrostatic latent image of the black component is formed.

Thereafter, the surface of the photosensitive drum 11 on which the electrostatic latent image of each color is formed reaches a position facing the developing device 13 (see FIG. 2). Then, toner of each color is supplied onto the photoreceptor drum 11 from each developing device 13, and the latent image on the photoreceptor drum 11 is developed (this is a developing process).
Thereafter, the surfaces of the photoreceptor drums 11 after the development process reach positions facing the intermediate transfer belt 17 (intermediate transfer body) serving as an image carrier. Here, a primary transfer roller 14 is installed at each opposing position so as to come into contact with the inner circumferential surface of the intermediate transfer belt 17. Then, at the position of the primary transfer roller 14, the toner images of each color formed on the photoreceptor drum 11 are sequentially transferred onto the intermediate transfer belt 17 in an overlapping manner (this is a primary transfer step).

After the primary transfer process, the surfaces of the photosensitive drums 11 each reach a position facing the cleaning device 15 (see FIG. 2). Then, the cleaning device 15 collects the untransferred toner remaining on the photoreceptor drum 11 (this is a cleaning process).
Thereafter, the surface of the photoreceptor drum 11 passes through the position of the static eliminator, and a series of image forming processes on the photoreceptor drum 11 are completed.

On the other hand, the surface of the intermediate transfer belt 17, onto which the images of each color are superimposed and transferred on the photosensitive drum 11, travels in the direction of the arrow in FIG. 1 and reaches the position of the secondary transfer roller 18. Then, at the position of the secondary transfer roller 18, the full-color image on the intermediate transfer belt 17 is secondarily transferred onto the sheet P (this is a secondary transfer process).
After that, the surface of the intermediate transfer belt 17 reaches the position of the intermediate transfer belt cleaning device 9 (cleaning device). Then, the untransferred toner on the intermediate transfer belt 17 is collected by the intermediate transfer belt cleaning device 9, and a series of transfer processes on the intermediate transfer belt 17 is completed.

Here, the sheet P at the position of the secondary transfer roller 18 is conveyed from the paper feeder 7 via a conveyance guide, registration rollers 19, and the like.
Specifically, the sheet P is fed by the paper feed roller 8 from the paper feed device 7 that stores the sheet P. After passing through a conveyance guide, the sheet P is guided to the registration rollers 19 . The sheet P that has reached the registration rollers 19 is conveyed toward the secondary transfer roller 18 in synchronization with the toner image on the intermediate transfer belt 17 .

Thereafter, the sheet P on which the full-color image has been transferred is guided to the fixing device 20. In the fixing device 20, the color image is fixed onto the sheet P at the nip between the fixing roller and the pressure roller.
After the fixing process, the sheet P is discharged as an output image outside the apparatus main body 1 by the paper discharge roller 29, and then stacked on the paper discharge section 5, completing a series of image forming processes.

Next, referring to FIG. 2, the image forming section of the image forming apparatus will be described in detail.
FIG. 2 is a configuration diagram showing the process cartridge 10BK for black color. The other three process cartridges 10Y, 10M, and 10C have almost the same configuration as the black process cartridge 10BK, except for the difference in the color of toner used in the image forming process, so they are illustrated and explained below. and is omitted.

As shown in FIG. 2, the process cartridge 10BK includes a photoreceptor drum 11 as an image carrier, a charging device 12 that charges the photoreceptor drum 11, and an electrostatic latent image formed on the photoreceptor drum 11. A developing device 13 that performs development and a cleaning device 15 that collects untransferred toner on the photosensitive drum 11 are integrally housed in a case.

Here, the photoreceptor drum 11 is a negatively chargeable organic photoreceptor, and has a photosensitive layer etc. provided on a drum-shaped conductive support. This is a charging roller coated with a resistive elastic layer. A predetermined voltage is applied from a power source to this charging device 12 (charging roller), thereby uniformly charging the surface of the opposing photoreceptor drum 11.

The developing device 13 mainly includes a developing roller 13a facing the photosensitive drum 11, a first conveying screw 13b1 facing the developing roller 13a, and a second conveying screw 13b2 facing the first conveying screw 13b1 via a partition member. and a doctor blade 13c facing the developing roller 13a. The developing roller 13a includes a magnet that is fixedly installed inside and forms a magnetic pole on the circumferential surface of the roller, and a sleeve that rotates around the magnet. A plurality of magnetic poles are formed on the developing roller 13a (sleeve) by the magnet, and the developer is carried on the developing roller 13a.
A two-component developer consisting of carrier and toner is housed within the developing device 13 .

The cleaning device 15 includes a cleaning blade 15a that comes into contact with the photosensitive drum 11, and a conveyance screw 15b that conveys the untransferred toner collected in the cleaning device 15 as waste toner toward a waste toner collection container 30 (see FIG. 3). (transport pipe 16), etc. are installed. The cleaning blade 15a is made of a rubber material such as urethane rubber, and contacts the surface of the photoreceptor drum 11 at a predetermined angle and with a predetermined pressure. As a result, deposits such as untransferred toner on the photoreceptor drum 11 are mechanically scraped off and collected into the cleaning device 15. The untransferred toner collected in the cleaning device 15 is then transferred to a waste toner conveying device 40 (see FIG. 3) as a powder conveying device via a conveying pipe 16 (a conveying screw 15b is installed therein). The waste toner is conveyed to the waste toner collection container 30 and collected therein as waste toner (powder). The conveyance screw 15b receives driving force from a drive motor via a gear 50 (see FIG. 3), and is rotated in the direction of the arrow in FIGS. 2 and 3.
Similarly, with reference to FIG. 1, an intermediate transfer belt cleaning device 9 as a cleaning device includes a cleaning blade that contacts the intermediate transfer belt 17, and a cleaning blade that converts untransferred toner collected in the intermediate transfer belt cleaning device 9 into waste toner. A conveying screw (conveying pipe 16) and the like for conveying the waste toner toward the waste toner collection container 30 (see FIG. 3) are installed. The untransferred toner collected in the intermediate transfer belt cleaning device 9 is then transported to the waste toner collection container 30 by the waste toner transport device 40 via the transport pipe 16 (in which a transport screw is installed). Then, the toner is collected as waste toner (powder) inside the waste toner collection container 30. Note that the waste toner conveying device 40 will be explained in more detail later.
In addition to the untransferred toner, the deposits that adhere to the photoreceptor drum 11 and the intermediate transfer belt 17 include paper dust generated from the sheet P (paper) and particles generated on the photoreceptor drum 11 during discharge by the charging device 12. There are discharge products, additives added to toner, etc., but in this application, these will be collectively referred to as "untransferred toner".

Referring to FIG. 2, the above-described imaging process will be explained in more detail.
The developing roller 13a is rotating in the arrow direction (counterclockwise) in FIG. The developer in the developing device 13 is replenished from the toner container 28 by a toner replenishing section (not shown) through the rotation of the first conveyance screw 13b1 and the second conveyance screw 13b2, which are arranged with a partition member interposed therebetween. The toner particles circulate in the longitudinal direction while being agitated and mixed together with the toner particles (this is the direction perpendicular to the plane of the paper in FIG. 2).

The toner that has been frictionally charged and attracted to the carrier is carried on the developing roller 13a together with the carrier. The developer carried on the developing roller 13a then reaches the position of the doctor blade 13c. After the developer on the developing roller 13a is adjusted to an appropriate amount at the position of the doctor blade 13c, it reaches a position facing the photoreceptor drum 11 (which is a developing area).
Thereafter, in the development area, toner in the developer adheres to the electrostatic latent image formed on the surface of the photoreceptor drum 11. Specifically, the toner is formed into a latent image by an electric field formed by a potential difference (development potential) between the latent image potential (exposure potential) of the image area irradiated with the laser beam L and the development bias applied to the development roller 13a. (a toner image is formed).
Thereafter, most of the toner attached to the photoreceptor drum 11 in the developing process is transferred onto the intermediate transfer belt 17. Then, the untransferred toner remaining on the photosensitive drum 11 is collected into the cleaning device 15 by the cleaning blade 15a.

The waste toner conveying device 40 as a powder conveying device installed in the image forming apparatus 1 in this embodiment will be described below.
Referring to FIG. 3, a waste toner conveying device 40 as a powder conveying device collects waste toner in the form of powder collected by the cleaning device 15 and the intermediate transfer belt cleaning device 9 and conveyed through the conveying pipe 16. , and transported in the direction of the black arrow in FIG. 3 toward the waste toner collection container 30.
The waste toner collection container 30 is removably (replaceably) installed in the image forming apparatus main body 1, and when the waste toner collection container 30 is attached to the image forming apparatus main body 1, the waste toner transport device 40 (cross It will be communicatively connected to the transport path 42). Then, the waste toner transported by the waste toner transport device 40 is collected inside the waste toner collection container 30.

Here, as shown in FIG. 3, the waste toner conveyance device 40 (powder conveyance device) is provided with a drop conveyance path 41, a cross conveyance path 42, a conveyance screw 43, a floating member 45, and the like.
The falling conveyance path 41 is a conveyance path through which toner (waste toner) as a powder that flows in from the inflow port 41a falls under its own weight, and in this embodiment, it is formed to extend substantially vertically. . Furthermore, the drop conveyance path 41 in this embodiment is formed so that its cross section (horizontal cross section) is approximately circular. Further, the inlet 41 a of the drop conveyance path 41 is connected to an outlet formed on the downstream side of the conveyance pipe 16 .
The cross conveyance path 42 is a conveyance path extending in a cross direction that intersects with the drop conveyance path 41, and its upper portion communicates with the lower end (outlet 41b) of the fall conveyance path 41. In this embodiment, the cross conveyance path 42 extends straight in a substantially horizontal direction, and is formed so that its cross section is circular, slightly larger than the screw diameter of a conveyance screw 43, which will be described later.
The conveyance screw 43 is disposed inside the cross conveyance path 42 and rotates in a predetermined direction (the direction of the arrow in FIG. 3) to convey the toner in the cross direction. The conveyance screw 43 has a screw portion 43b wound around a shaft portion 43a in a spiral manner, and is driven to rotate in the direction of the arrow by inputting driving force from a drive motor via a gear 44. The transport screw 43 is rotatably supported at both ends in the axial direction by the housing of the waste toner transport device 40 . Further, in the present embodiment, both the shaft portion 43a and the screw portion 43b of the conveying screw 43 are made of a metal material with high mechanical strength such as stainless steel.

In this embodiment, the falling conveyance path 41 is formed to extend in a substantially vertical direction, but the falling conveyance path 41 may be any path that allows waste toner to fall under its own weight, for example, in the vertical direction. Alternatively, the toner may be allowed to slide down an inclined surface and fall under its own weight.
Further, in the present embodiment, the cross conveyance path 42 is formed to extend in a substantially horizontal direction, but the cross conveyance path 42 may be of any type as long as the waste toner is conveyed in the cross direction by the conveyance screw 43, for example. , it may be one that is inclined with respect to the horizontal direction, or one that has a curved conveyance path formed in part or all of it.

Here, in the waste toner conveyance device 40 in this embodiment, a movable member 45 is movably installed inside the drop conveyance path 41. This floating member 45 moves freely within the falling conveyance path 41 due to contact with the conveyance screw 43 rotating in a predetermined direction (the direction of the arrow in FIG. 3), and the vertical relationship does not change, such as falling sideways. It randomly hits the inner wall surface of the falling conveyance path 41 while maintaining its orientation to some extent.
Specifically, the floating member 45 is a columnar member that extends in substantially the same direction (vertical direction) as the falling conveyance path 41, and is not supported by any member and moves within the falling conveyance path 41. It is placed on the conveying screw 43 in a free state.
In addition, the floating member 45 has a cross-sectional diameter R1 (see FIG. 4) at its lower end that is set in the above-mentioned gap so that the floating member 45 can freely move on the rotating conveying screw 43 without entering the gap between the conveying screw 43 and the cross conveying path 42. It is set to be larger.

Then, the floating member 45 moves to the left in FIG. 3 along the rotation of the conveyance screw 43 and collides with the left inner wall surface of the falling conveyance path 41, or due to the reaction or the upper part loses its balance. It collides with the inner wall surface other than the left one, swings randomly in a free direction in a free posture, and collides with the inner wall surface of the falling conveyance path 41 almost uniformly.
As a result, the movable member 45 covers almost the entire inner wall surface of the falling conveyance path 41, with a relatively wide operating range upward from the lower end of the falling conveyance path 41 (which is the communication portion with the cross conveyance path 42). Since the toner collides over the circumference, it is possible to reduce the problem of waste toner adhering to the inner wall surface of the falling conveyance path 41. Further, even if waste toner adheres to the inner wall surface of the falling conveyance path 41, the adhering toner can be removed by the collision of the floating member 45. Therefore, the problem that the falling conveyance path 41 is blocked by the adhered toner is also prevented.
In particular, toner adhesion to the inner wall surface of the falling conveyance path 41 is less likely to occur on the upper end side of the falling conveyance path 41, but more likely to occur in the range from the lower end to the center. It becomes useful to set the length H (see Figure 4).
Further, since waste toner tends to adhere to the inner wall surface of the falling conveyance path 41 compared to new toner (fresh toner), it is useful to install the floating member 4 in the falling conveyance path 41 for waste toner. .

Here, in this embodiment, the hardness of the floating member 45 is configured to be smaller than the hardness of the conveyance screw 43.
Specifically, in this embodiment, the floating member 45 is made of a material such as a rubber material or a resin material, and has a lower hardness than the conveyance screw 43 made of a metal material.
By setting the hardness of the floating member 45 to be smaller than the hardness of the conveying screw 43 in this way, it is possible to reduce the problem that the conveying screw 43 is worn out due to repeated contact with the floating member 45. Therefore, good toner conveyance by the conveyance screw 43 is stably maintained over time.
Note that the hardness of the floating member 45 may be smaller as a whole than the hardness of the conveying screw 43, or may be smaller only in the surface portion. That is, the hardness of at least the surface (outer surface) of the floating member 45 can be configured to be smaller than the hardness of the conveying screw 43.

In addition, the floating member 45 will wear out due to repeated contact with the conveyance screw 43, but the worn portion is limited to the bottom portion that contacts the conveyance screw 43, and the inner wall surface of the falling conveyance path 41 Since the part that collides with the toner hardly wears, and the length H (see Fig. 4) of the collided part is set to be sufficiently long, the function of preventing toner from adhering to the inner wall surface of the falling conveyance path 41 is effective. It will be maintained stably over time. Furthermore, by using the pillar-shaped floating member 45, even if the bottom of the floating member 45 is worn out, the floating member 45 is caught between the screw portions 43b of the conveyance screw 43, compared to the case where a spherical one is used. Inconveniences such as malfunction or damage to the screw 43 will not occur.

Further, in the present embodiment, the hardness of the floating member 45 is configured to be smaller than the hardness of the inner wall surface of the falling conveyance path 41 (formed of a relatively strong resin material).
Thereby, it is possible to reduce the problem that the falling conveyance path 41 is worn out due to repeated contact with the floating member 45.
Note that the hardness of the floating member 45 may be smaller as a whole than the hardness of the inner wall surface of the falling conveyance path 41, or only the surface portion may be smaller. That is, the hardness of at least the surface (outer surface) of the floating member 45 can be configured to be smaller than the hardness of the inner wall surface of the falling conveyance path 41.

In this embodiment, the floating member 45 is preferably an elastic body made of an elastic material such as a rubber material.
As a result, the hardness of the floating member 45 can be made considerably smaller than the hardness of the conveying screw 43 formed of a metal material, so that the effect of reducing the wear of the conveying screw 43 is more likely to be exhibited. Furthermore, by making the floating member 45 an elastic body, the elastic force increases the reaction when the floating member 45 hits the conveying screw 43 or the inner wall surface of the falling conveying path 41. , the effect of preventing toner from adhering to the inner wall surface is more likely to be exhibited.

Further, as shown in FIGS. 3 and 4, in the present embodiment, the floating member 45 is formed into a substantially conical (columnar) shape so that the cross section is circular.
When the floating member 45 is formed to have a polygonal cross section, the corner portion thereof hits the inner wall surface of the falling conveyance path 41 and wears out, and the state of collision with the inner wall surface changes over time. Therefore, the effect of preventing toner from adhering to the inner wall surface may change over time. On the other hand, by using the floating member 45 having a circular cross section, such problems can be alleviated.

Furthermore, as shown in FIG. 4, the floating member 45 in this embodiment has a through hole 45a formed therein.
By providing the through hole 45a in the floating member 45 in this manner, the weight of the floating member 45 is reduced, and wear on the inner wall surfaces of the conveying screw 43 and the falling conveying path 41 due to collisions of the floating member 45 can be further reduced. . Furthermore, by reducing the weight of the floating member 45, the reaction force when the floating member 45 hits the conveying screw 43 or the inner wall surface becomes larger, so that the floating member 45 moves widely, which has the effect of preventing toner from adhering to the inner wall surface. becomes easier to demonstrate.
Furthermore, by providing the through hole 45a in the floating member 45, some of the waste toner that falls down the fall conveyance path 41 by its own weight will fall through the through hole 45a. In comparison, the fluidity (transportability) of waste toner in the falling transport path 41 can be improved.

Further, with reference to FIGS. 3 and 4, in this embodiment, the diameter (cross-sectional diameter) of the inscribed circle of the bottom surface (lower end) of the floating member 45 is set as R1, and the screw pitch of the conveying screw 43 is set as R1. When M is the plate thickness of the screw portion 43b of the conveying screw 43,
R1>MN
It is configured so that the following relationship is established.
If the above-mentioned relationship does not hold, the floating member 45 may fit or enter between the screw portions 43b of the conveying screw 43, and the floating member 45 may come into contact with the rotating conveying screw 43. There is a possibility that problems such as restriction of free movement or damage of the free movement member 45 may occur.
In contrast, in the present embodiment, the dimensions of the related members are determined so that the floating member 45 does not fit or enter between the screw portions 43b of the conveyance screw 43. The occurrence of such problems can be reduced.

Further, with reference to FIGS. 3 and 4, in this embodiment, the length of the floating member 45 is H, and the internal cross-sectional diameter (the largest part) of the falling conveyance path 41 is Dmax. When you do,
H>Dmax
It is configured so that the following relationship is established.
If the above-mentioned relationship does not hold, there is a possibility that the floating member 45 will fall down at a large angle with respect to the vertical direction and fit into the inner wall surface of the falling conveyance path 41. In such a case, the floating member 45 does not move freely, and the function of preventing toner adhesion is no longer exhibited.
On the other hand, in the present embodiment, the length H of the floating member 45 is set to be sufficiently larger than the cross-sectional diameter Dmax of the falling conveyance path 41, so that the occurrence of such problems can be reduced. can.
In this embodiment, the internal cross section of the drop transport path 41 is configured to be circular; however, when the internal cross section of the drop transport path 41 is rectangular, the length of the diagonal of the cross section is It is defined that the diameter is the cross-sectional diameter (D).

Further, in this embodiment, the specific gravity of the floating member 45 is set to be greater than the specific gravity of waste toner (powder).
As a result, a problem in which a large amount of waste toner is interposed between the conveyance screw 43 and the floating member 45 and the floating member 45 rises significantly with respect to the conveyance screw 43 can be alleviated. That is, even if there is a large amount of waste toner in the cross-conveying path 42, the floating member 45 will sneak into the waste toner due to the difference in specific gravity, and the floating member 45 will come into contact with the conveying screw 43. Become. Therefore, the floating member 45 comes into contact with the rotating conveyance screw 43 and moves freely, thereby maintaining the effect of reducing toner adhesion to the inner wall surface.

Here, referring to FIG. 3, the waste toner conveying device 40 in this embodiment is configured to be detachable from the conveying pipe 16 installed in the image forming apparatus main body 1. Further, the conveying pipe 16 is configured to be detachable from the waste toner conveying device 40 installed in the image forming apparatus main body 1. Further, the waste toner conveying device 40 is configured such that a cleaning device 90 (see FIG. 6) can be detachably attached to the inlet 41a of the falling conveying path 41 thereof.
With such a configuration, the drop conveyance path 41 can be used for the waste toner conveyance device 40 taken out from the image forming apparatus main body 1 or the waste toner conveyance device 40 in a state in which the conveyance tube 16 is taken out from the image forming apparatus main body 1. By connecting the suction port of the cleaning device 90 to the inlet 41a of the waste toner conveying device 40, it becomes possible to clean the waste toner conveying device 40. Specifically, by operating the cleaning device 90 with the cleaning device 90 set in the inlet 41a, the waste toner remaining in the waste toner conveying device 40 is sucked (removed) by the cleaning device 90. That will happen.
As shown in FIG. 3, the transport pipe 16 has a discharge port (an opening communicating with the inflow port 41a) that opens and closes in conjunction with the relative attachment/detachment operation of the waste toner transport device 40 to the transport pipe 16. A shutter 25 is provided. This prevents waste toner from leaking from the discharge port of the transport pipe 16 even if the waste toner transport device 40 is removed.

Hereinafter, the characteristic configuration and operation of the waste toner conveying device 40 as a powder conveying device in this embodiment will be described in detail.
Referring to FIGS. 3 to 6, in the waste toner conveying device 40 according to the present embodiment, the inlet 41a and the floating member 45 interfere with each other so that the floating member 45 does not come out from the inlet 41a of the falling conveying path 41. configured to be possible.
In other words, even if an attempt is made to take out the floating member 45 in the falling conveyance path 41 from the inlet 41a of the falling conveyance path 41, the inflow port 41a and the floating member 45 interfere with each other, so that the floating member 45 cannot be taken out.
Note that the inlet 41a of the drop conveyance path 41 becomes an opening connected to the suction port of the cleaning device 90 during suction and cleaning by the cleaning device 90 described above.

Specifically, as shown in FIG. 5, the opening area of the inlet 41a (the area surrounded by the solid line in FIG. 5) is the projected area of the floating member 45 (in FIG. 3) when viewed from the inlet 41a side. This is the projected area seen from the viewing direction A, which is the area surrounded by the broken line in FIG. 5.). Specifically, in this embodiment, the hole diameter D of the inlet 41a is configured to be smaller than the outer diameter R2 of the large diameter portion 45x (see FIG. 4) of the floating member 45 (D<R2). ).
More specifically, as previously explained using FIG. 3 and the like, the waste toner conveying device 40 in this embodiment is configured so that the vertical relationship of the floating member 45 does not change within the falling conveying path 41. There is. As shown in FIG. 6 and the like, the floating member 45 is formed into a columnar shape, and a large diameter portion 45x that can interfere with the inlet 41a is formed in at least a portion of the floating member 45. That is, even if an attempt is made to take out the floating member 45 from the inlet 41a, at least the large diameter portion 45x gets caught in the inlet 41a, making it impossible to take out the floating member 45.
Note that, as described above, since the floating member 45 does not turn sideways in the falling conveyance path 41, the side surface (height H portion) of the floating member 45 does not interfere with the inflow port 41a (it functions as an interfering portion). There is nothing to do). Therefore, it is useful to provide a large diameter portion 45x with a large cross-sectional diameter R2 (outer diameter) in a part of the columnar floating member 45.
Further, when the hole shape of the inlet 41a is not circular but square, the hole diameter D corresponds to the length of the diagonal of the corner.

In this manner, in this embodiment, the inlet 41a and the floating member 45 are configured to be able to interfere with each other, so that the problem that the floating member 45 slips out from the inlet 41a of the drop conveyance path 41 is less likely to occur.
More specifically, as shown in FIG. 6, during maintenance of the waste toner conveying device 40, the cleaning device 90 removes waste toner in the falling conveyance path 41 (waste toner conveying device 40) from the inlet 41a in the direction of the black arrow. Even when suctioning and cleaning is performed, the problem that the floating member 45 comes out of the inlet 41a due to suction is less likely to occur. Therefore, problems such as the floating member 45 being sucked into the cleaning device 90 and the floating member 45 being lost or being damaged are less likely to occur.

Note that in the floating member 45 in this embodiment, in addition to the large diameter portion 45x being formed larger than the inlet port 41a as described above, the large diameter portion 45x is also larger than the outlet port 41b. It is formed. Therefore, as it is, the floating member 45 cannot be set in the drop transport path 41 during the manufacturing process.
On the other hand, by forming the floating member 45 from an elastic material such as a rubber material, the floating member 45 can be set in the falling conveyance path 41 in a state in which it is elastically deformed during the manufacturing process.
In addition, by configuring the drop conveyance path 41 itself so that it can be divided into two (for example, by configuring it so that it can be divided into two half-conical members), it is possible to A member 45 can also be set.
Furthermore, when the large diameter portion 45x is formed to be smaller than the outlet 41b, the falling conveyance path 41 and the cross conveyance path 42 are configured to be separable, so that the cross conveyance path 42 is separated from the drop conveyance path 41 during the manufacturing process. The floating member 45 is set in the falling conveyance path 41 in a separated state from the outlet 41b, and then the cross conveying path 42 is connected to the falling conveyance path 41, thereby setting the floating member 45 in the falling conveyance path 41. You can also.

Here, as previously explained using FIG. 4, in this embodiment, the floating member 45 has a through hole 45a inside thereof along the direction in which the drop conveyance path 41 extends (the vertical direction). It is formed.
By providing the through hole 45a in the floating member 45 in this way, the weight of the floating member 45 is reduced as described above, and wear of the inner wall surface of the conveying screw 43 and the falling conveying path 41 due to collisions of the floating member 45 is reduced. is reduced, the floating member 45 moves widely, and the effect of preventing toner from adhering to the inner wall surface is more likely to be exhibited.Furthermore, some of the waste toner that falls under its own weight along the falling conveyance path 41 passes through the through hole 45a. Since the waste toner falls under its own weight through the drop conveyance path 41, the fluidity (transportability) of the waste toner can be improved.
Furthermore, in this embodiment, by providing the through hole 45a in the floating member 45, air containing waste toner flows within the through hole 45a when cleaning is performed using the cleaning device 90 (see FIG. 6). As a result, cleaning efficiency is improved.

In particular, as shown in FIGS. 4 and 6, the through hole 45a of the floating member 45 is formed so that the cross-sectional area (hole diameter) gradually increases from the lower end to the upper end.
As a result, when performing cleaning using the cleaning device 90 (see FIG. 6), the floating member 45 (through hole 45a) functions like a tapered nozzle of a vacuum cleaner to efficiently remove waste toner from the lower end. (further improves cleaning performance).

Further, as shown in FIG. 3 and the like, in this embodiment, the drop conveyance path 41 and the floating member 45 are each formed so that the cross-sectional area gradually increases from the lower end to the upper end.
Specifically, the inside of the drop conveyance path 41 and the floating member 45 are both formed into a substantially conical shape so that the clearance of the floating member 45 with respect to the inner wall surface of the fall conveyance path 41 is approximately uniform from the lower end to the upper end. has been done.
With this configuration, the floating member 45 moves in a well-balanced manner in contact with each other within the falling conveyance path 41, thereby effectively reducing the problem of waste toner adhering to the inner wall surface of the falling conveyance path 41. be able to.

<Modification 1>
As shown in FIG. 7, in the waste toner conveying device 40 (powder conveying device) according to modification 1, the large diameter portion 45x of the floating member 45 is formed at the upper end like the floating member 45 shown in FIG. Rather, it is formed at a position other than the upper end (in the example of FIG. 7, it is near the lower end with respect to the upper end).
Even when the floating member 45 is configured in this way, the upper part of the floating member 45 protrudes upward from the inflow port 41a due to suction during cleaning by the cleaning device 90, but the large diameter portion 45x Since the floating member 45 is caught in the inlet 41a, it does not come out from the inlet 41a.
Note that the position and number of the large diameter portions 45x formed in the floating member 45 are not limited to those shown in FIG. 4 or FIG. 7.
Also, in the floating member 45 in Modification 1, a through hole 45a is formed inside along the direction in which the drop conveyance path 41 extends (the vertical direction), similarly to those shown in FIGS. 4 and 6. can do.

<Modification 2>
As shown in FIG. 8, in the waste toner conveyance device 40 (powder conveyance device) in Modification 2, the drop conveyance path 41 has an opening area of the inflow port 41a (the opening area of the hole diameter D1). , is formed to be smaller than the cross-sectional area (this is the cross-sectional area of the inner diameter portion of the inner diameter D2) perpendicular to the direction in which the falling conveyance path 41 extends in a portion excluding the inlet 41a.
Further, in the second modification, a cylindrical (hollow cylindrical) floating member 45 whose outer diameter is R2 is used in accordance with the cross-sectional area (inner diameter D2) of the falling conveyance path 41. The outer diameter R2 of the floating member 45 is set to be larger than the hole diameter D1 of the inlet 41a (R2>D1).
Even with this configuration, the problem that the floating member 45 slips out from the inlet 41a of the drop conveyance path 41 can be prevented from occurring.
Note that the floating member 45 in Modification 2 also has a through hole 45a formed therein along the direction in which the drop conveyance path 41 extends (the vertical direction), similarly to those shown in FIGS. 4 and 6. can do.

<Modification 3>
As shown in FIG. 9, the waste toner conveyance device 40 (powder conveyance device) according to the third modification has an upstream fall conveyance path in which waste toner (powder) falls under its own weight toward an inlet 41a of a fall conveyance path 41. 49 are provided.
Specifically, an upstream drop conveyance path 49 is provided that connects to the inlet 41a and has a hole diameter D smaller than the outer diameter R2 of the large diameter portion 45x of the floating member 45.
In other words, when the upstream fall conveyance path 49 and the fall conveyance path are viewed as one integrated fall conveyance path, there is an opening 41a in the center of the fall conveyance path that restricts the floating member 45 from slipping out. It will be established.
Even with this configuration, the problem that the floating member 45 slips out from the inlet 41a of the drop conveyance path 41 can be prevented from occurring.
In addition, in the third modification, the upstream falling conveyance path 49 is formed in a funnel shape, so when the cleaning device 90 cleans, the upstream falling conveyance path 49 functions like a tapered nozzle of a vacuum cleaner. Therefore, waste toner can be efficiently sucked (cleaning performance is improved).
Note that the floating member 45 in Modification 3 also has a through hole 45a formed therein along the direction in which the drop conveyance path 41 extends (the vertical direction), similarly to those shown in FIGS. 4 and 6. can do.

<Modification 4>
As shown in FIG. 10, in the waste toner conveyance device 40 (powder conveyance device) in Modification 4, the inlet 41a of the falling conveyance path 41 is provided with a restriction member 41c that restricts the loose member 45 from slipping out. .
Specifically, at the inlet 41a (including positions near the inlet), a restriction member 41c in which two rod-shaped members intersect in a cross shape is installed. This restricting member 41c prevents the floating member 45 from coming out from the inlet 41a without interfering with the inflow of waste toner from the conveying pipe 16 (see FIG. 3) to the falling conveying path 41 via the inlet 41a. If so, it is not limited to what is shown in FIG.
In the case of this configuration, the inlet port 41a and the large diameter portion of the floating member 45 are not set in size, and the inlet port 41a is arranged so that the floating member 45 does not slip out from the inlet port 41a of the drop conveyance path 41. 41a and the floating member 45 are configured to be able to interfere with each other. That is, even if an attempt is made to take out the floating member 45 in the falling conveyance path 41 from the inlet 41a of the falling conveyance path 41, the restricting member 41c of the inlet 41a and the floating member 45 interfere with each other, making it impossible to take it out.
Note that the floating member 45 in Modified Example 4 also has a through hole 45a formed therein along the direction in which the drop conveyance path 41 extends (the vertical direction), similarly to those shown in FIGS. 4 and 6. can do.

<Modification 5>
As shown in FIG. 11, the powder conveyance device 40 in the fifth modification directs the waste developer (powder) discharged from the developing device 13 to a waste developer collection container 30 (waste toner collection container). It is for transportation.
The developing device 13 in Modification 5 is appropriately supplied with developer (a two-component developer consisting of toner and carrier) from a developer container (not shown). When the developer is supplied into the developing device 13, the surplus developer that exceeds the height of the discharge port 13x formed in the developer case is discharged from the discharge port 13x, and is discharged from the relay fall path 13w. The powder flows into the falling conveyance path 41 of the powder conveyance device 40 via . The developer that has flowed into the falling conveyance path 41 is then collected into the waste developer collection container 30 via the cross conveyance path 42. With this configuration, it becomes possible to refresh the developer contained in the developing device 13 as appropriate.
Here, the powder conveying device 40 in the fifth modification is also configured so that the inlet 41a and the floating member 45 can interfere with each other so that the floating member 45 does not slip out from the inlet 41a of the falling conveyance path 41. The problem that the floating member 45 slips out from the inlet 41a of the drop conveyance path 41 can be prevented from occurring.
Note that the floating member 45 in Modified Example 5 also has a through hole 45a formed therein along the direction in which the drop conveyance path 41 extends (the vertical direction), similarly to those shown in FIGS. 4 and 6. can do.

As described above, the waste toner conveyance device 40 (powder conveyance device) according to the present embodiment has a fall conveyance path 41 in which the waste toner (powder) flowing in from the inlet 41a falls under its own weight, and a fall conveyance path 41. A cross conveyance path 42 that communicates with the lower end of the drop conveyance path 41 and extends in a cross direction that intersects with the falling conveyance path 41; and a floating member 45 that moves freely within the drop conveyance path 41 by contact with the conveyance screw 43 that is movably installed inside the fall conveyance path 41 and rotates in a predetermined direction. The inflow port 41a and the floating member 45 are configured to interfere with each other so that the floating member 45 does not slip out from the inflow port 41a of the drop conveyance path 41.
Thereby, the problem that the floating member 45 slips out from the inlet 41a of the drop conveyance path 41 can be prevented from occurring.

In the present embodiment, a waste toner conveying device 40 (powder conveying device) is used in which untransferred toner collected by the cleaning device 15 and the intermediate transfer belt cleaning device 9 is conveyed as waste toner toward the waste toner collection container 30. ), but the application of the present invention is not limited thereto. For example, only untransferred toner collected by a cleaning device for a photoreceptor drum is collected as waste toner in the waste toner collection container 30. Naturally, the present invention can also be applied to the waste toner conveying device 40 that is conveyed toward.
Further, in this embodiment, the present invention is applied to the waste toner conveying device 40 (powder conveying device) that conveys waste toner in the form of powder, but the present invention is not limited to this. For example, the untransferred toner (powder) collected by the cleaning device 15 is transported to the developing device 13 as recycled toner, or the waste developer (powder) discharged from the developing device is used. The powder conveying device (see Figure 11) transports the waste developer to the waste developer collection container, and the new toner (powder) and two-component developer (powder) are transported to the developing device. The present invention can also be applied to powder conveyance devices and the like.
Even in such cases, the same effects as those of this embodiment can be obtained.

Note that it is clear that the present invention is not limited to this embodiment, and that this embodiment can be modified as appropriate within the scope of the technical idea of the present invention in addition to what is suggested in this embodiment. be. Further, the number, position, shape, etc. of the constituent members are not limited to those in this embodiment, and can be set to a number, position, shape, etc. suitable for implementing the present invention.

In addition, in the specification of this application, etc., "column shape" includes not only a cylindrical shape and a polygonal column shape in which the cross-sectional area is constant in the direction in which the column extends, but also a shape in which the cross-sectional area is not constant in the direction in which the column extends, for example, It is defined to include conical, polygonal pyramidal, and drum-shaped shapes.
Furthermore, in the specification of this application, etc., the "large diameter portion" of a floating member refers to the "large diameter portion" of the floating member even when the cross section of the floating member (a cross section perpendicular to the direction in which it extends in a columnar shape) is circular. Even if the cross section is polygonal, it is defined as the part where the cross-sectional area is maximum.

Note that the embodiments of the present invention can also be, for example, a combination of Supplementary Notes 1 to 10 as shown below.
(Additional note 1)
A falling conveyance path in which the powder flowing in from the inlet falls under its own weight;
a cross-conveyance path that communicates with the lower end of the drop-conveyance path and extends in a cross direction that intersects with the fall-conveyance path;
a conveyance screw that is installed in the cross conveyance path and rotates in a predetermined direction to convey the powder in the cross direction;
a movable member that is movably installed inside the drop conveyance path and moves freely within the fall conveyance path by contact with the conveyance screw rotating in the predetermined direction;
Equipped with
A powder conveying device characterized in that the inlet and the floating member are configured to interfere with each other so that the floating member does not slip out of the inlet of the falling conveyance path.
(Additional note 2)
The powder conveying device according to appendix 1, wherein the opening area of the inlet is smaller than the projected area of the floating member when viewed from the inlet side.
(Additional note 3)
configured so that the vertical relationship of the floating member does not change within the falling conveyance path,
The powder conveying device according to Supplementary Note 1 or 2, wherein the floating member is formed in a columnar shape and has a large diameter portion formed in at least a portion thereof that can interfere with the inlet.
(Additional note 4)
The powder conveyance device according to any one of appendices 1 to 3, wherein the floating member has a through hole formed inside thereof along the direction in which the falling conveyance path extends.
(Appendix 5)
4. The powder conveying device according to appendix 4, wherein the through hole of the floating member is formed so that the cross-sectional area gradually increases from the lower end to the upper end.
(Appendix 6)
The powder conveyance device according to any one of appendices 1 to 5, wherein the falling conveyance path and the floating member are each formed such that a cross-sectional area gradually increases from a lower end to an upper end.
(Appendix 7)
Supplementary note 1, wherein the falling conveyance path is formed such that the opening area of the inlet is smaller than the cross-sectional area perpendicular to the direction in which the falling conveyance path extends in a portion excluding the inlet. - The powder conveying device according to any one of Appendix 6.
(Appendix 8)
The powder conveyance device according to any one of Supplementary Notes 1 to 7, further comprising an upstream fall conveyance path in which the powder falls under its own weight toward the inlet of the fall conveyance path.
(Appendix 9)
8. The powder conveying device according to any one of appendices 1 to 8, wherein the inlet includes a restriction member that restricts the floating member from slipping out.
(Appendix 10)
An image forming apparatus comprising the powder conveying device according to any one of Supplementary Notes 1 to 9.

1 Image forming device (image forming device main body),
15 cleaning device,
16 conveyor pipe,
30 Waste toner collection container,
40 Waste toner conveyance device (powder conveyance device),
41 Falling conveyance route,
41a inlet, 41b outlet,
41c restriction member,
42 Cross conveyance route,
43 Conveyance screw,
43a shaft part, 43b screw part,
45 floating member (column member),
45a through hole,
45x large diameter part,
49 Upstream side falling conveyance route,
90 Cleaning equipment.

JP2020-201476A

Claims (10)

A falling conveyance path in which the powder flowing in from the inlet falls under its own weight;
a cross-conveyance path that communicates with the lower end of the drop-conveyance path and extends in a cross direction that intersects with the fall-conveyance path;
a conveyance screw that is installed in the cross conveyance path and rotates in a predetermined direction to convey the powder in the cross direction;
a movable member that is movably installed inside the drop conveyance path and moves freely within the fall conveyance path by contact with the conveyance screw rotating in the predetermined direction;
Equipped with
A powder conveying device characterized in that the inlet and the floating member are configured to interfere with each other so that the floating member does not slip out of the inlet of the falling conveyance path. The powder conveying device according to claim 1, wherein the opening area of the inlet is smaller than the projected area of the floating member when viewed from the inlet side. configured so that the vertical relationship of the floating member does not change within the falling conveyance path,
The powder conveying device according to claim 1 or 2, wherein the floating member is formed into a columnar shape and has a large diameter portion formed in at least a portion thereof that can interfere with the inlet. 3. The powder conveyance device according to claim 1, wherein the floating member has a through hole formed therein along the direction in which the falling conveyance path extends. 5. The powder conveying device according to claim 4, wherein the through hole of the floating member is formed so that its cross-sectional area gradually increases from the lower end to the upper end. 3. The powder conveyance device according to claim 1, wherein the falling conveyance path and the floating member are each formed such that a cross-sectional area gradually increases from a lower end to an upper end. The falling conveyance path is formed such that the opening area of the inlet is smaller than the cross-sectional area perpendicular to the direction in which the falling conveyance path extends in a portion excluding the inlet. 3. The powder conveying device according to claim 1 or claim 2. 3. The powder conveyance device according to claim 1, further comprising an upstream fall conveyance path in which the powder falls under its own weight toward the inlet of the fall conveyance path. 2. The powder conveying device according to claim 1, wherein the inlet includes a restriction member that restricts the floating member from slipping out. An image forming apparatus comprising the powder conveying device according to claim 1 or 2.

Images