JP5594906B2 - Stirring member, developing device including the same, and image forming apparatus - Google Patents

Description

  The present invention relates to an agitating member having a screw for agitating and conveying a developer used in a copying machine, a printer, a facsimile, a composite machine thereof, and the like, a developing device including the same, and an image forming apparatus including the stirring device. is there.

  The developing device includes a developing roller that supplies the developer to the photosensitive member, and a stirring member that stirs and conveys the developer and supplies the developer to the developing roller. The stirring member sufficiently stirs and stirs the developer. It is necessary to supply the developer in a uniformly distributed manner in the longitudinal direction of the developing roller. The stirring member is provided with a spiral screw on the outer periphery of the stirring shaft extending in the longitudinal direction in order to stir and transport the developer.

  However, since the agitation shaft extends in the longitudinal direction, the diameter of the agitation shaft increases when the developer adheres to and accumulates on the outer peripheral surface of the agitation shaft during agitation and conveyance. As a result, there is a problem that the developer cannot be sufficiently stirred, and a space in which the developer is transported becomes narrow and transportability is lowered.

  Therefore, in the stirring member described in Patent Document 1, a hollow screw with the stirring shaft removed from the stirring member is attached to a plurality of ribs extending in the longitudinal direction. With this configuration, the developer is prevented from adhering and accumulating on the stirring shaft, and the developer transportability is improved.

JP 2004-307140 A (paragraphs [0007] and [0008], FIG. 2)

  However, the above-described stirring member of Patent Document 1 has a disadvantage that the developer stirred by the screw adheres to the downstream end portions of the plurality of ribs with respect to the rotation direction of the stirring member.

  The present invention has been made in order to solve the above-described problems, and prevents the developer from adhering to the ribs between the blades of the hollow screw, so that the developer can be conveyed with good transportability. It is an object of the present invention to provide a member, a developing device using the member, and an image forming apparatus including the developing device.

  In order to achieve the above object, a first invention is an agitating member that agitates a developer and conveys the developer in a longitudinal direction. The agitating member is rotatably supported on one rotating shaft and the other is rotatably supported. Between a rotating shaft, a screw that forms a hollow portion in a spiral portion that extends spirally from the one rotating shaft to the other rotating shaft, and the spiral portion that is opposed in the longitudinal direction of the screw A rib formed on the downstream end in the rotational direction and having an inclined surface inclined at a predetermined angle with respect to the rotational direction at the downstream end. .

  In the second invention, in the agitating member, the inclined surface is inclined at an angle smaller than 45 degrees with respect to the rotation direction at the downstream end.

  In the third aspect of the present invention, in the stirring member, the downstream end portion of the rib has the inclined surface and a flat surface that is flat in a direction perpendicular to the rotation direction at the downstream end portion. The flat surface and the inclined surface each have a width in the perpendicular direction, and the width of the flat surface is smaller than the width of the inclined surface.

  According to a fourth aspect of the present invention, there is provided a developing device including the stirring member having the above-described configuration and a developing container in which the stirring member and the developer are accommodated.

  According to a fifth aspect of the present invention, in the developing device, the developer container has a first transport path in which the developer is transported in a predetermined direction, and the developer is transported in a direction opposite to the first transport path. And a second conveying path that extends in parallel adjacent to the first conveying path, a partition member that partitions the first and second conveying paths, and a developer in the first and second conveying paths. And a communicating portion in which both end sides in the longitudinal direction of the partition member are opened so as to circulate, and the stirring member includes a first stirring member disposed in the first conveyance path, A second agitating member disposed in the second conveyance path, wherein the first and second agitating members are provided to face the communicating portion, respectively, and the inclined surface is an axial center of the rotation shaft It is characterized by being provided on the outer edge side of the rib with reference to.

  According to a sixth aspect of the invention, there is provided an image forming apparatus including the developing device having the above-described configuration.

  According to the first invention, since the screw extends spirally and is formed in a hollow shape, the stirred developer is favorably conveyed while being dispersed in the hollow portion. As the stirring member rotates, the downstream end of the rib circulates in contact with the developer, but the inclined surface is formed at the downstream end of the rib, so that the development in the vicinity of the downstream end is performed. Since the developer slides along the inclined surface with respect to the rib and moves upstream, the developer does not adhere to the rib, and good transportability of the developer can be obtained.

The figure which shows schematic structure of the image forming apparatus provided with the stirring member which concerns on 1st Embodiment of this invention. Sectional drawing which shows schematic structure of the developing apparatus provided with the stirring member which concerns on 1st Embodiment. Sectional top view which shows the stirring part of the developing device which concerns on 1st Embodiment. The perspective view which shows the stirring member which concerns on 1st Embodiment. The side view which shows typically the screw and rib of the stirring member which concern on 1st Embodiment. The side view which shows typically the screw and rib of the stirring member which concern on 2nd Embodiment. The side view which shows typically the screw and rib of the stirring member which concern on 3rd Embodiment. The side view which shows typically the screw and rib of the stirring member which concern on 4th Embodiment.

  Embodiments of the present invention will be described below with reference to the drawings, but the present invention is not limited to these embodiments. Further, the use of the invention and the terms shown here are not limited thereto.

(First embodiment)
FIG. 1 is a diagram illustrating a schematic configuration of an image forming apparatus including a stirring member according to an embodiment of the present invention. The image forming apparatus 1 includes a paper feed unit 2 disposed in a lower portion thereof, a paper transport unit 3 disposed on the right side of the paper feed unit 2, and an image forming unit disposed on the upper side of the paper transport unit 3. 4, a fixing unit 5 disposed on the discharge side of the image forming unit 4, and an image reading unit 6 disposed on the upper side of the image forming unit 4 and the fixing unit 5.

  The paper feed unit 2 includes a plurality of paper feed cassettes 7 for containing paper 9, and the paper 9 is picked up from the selected paper feed cassette 7 among the plurality of paper feed cassettes 7 by rotating the paper feed roller 8. One by one is sent to the paper transport unit 3.

  The paper 9 sent to the paper transport unit 3 is transported toward the image forming unit 4 via the paper supply path 10. The image forming unit 4 forms a toner image on a sheet 9 by an electrophotographic process, and a photoreceptor 11 that can rotate in a predetermined direction (the arrow direction in FIG. 1), and the periphery of the photoreceptor 11. A charging unit 12, a developing device 14, a transfer unit 15, a cleaning unit 16, and a charge removal unit 17 are provided along the rotation direction.

  The charging unit 12 includes a charging wire to which a high voltage is applied. When a predetermined potential is applied to the surface of the photoconductor 11 by corona discharge from the charging wire, the surface of the photoconductor 11 is uniformly charged. . Then, when light based on the image data of the original read by the image reading unit 6 is irradiated to the photoconductor 11 by the exposure unit 13, the surface potential of the photoconductor 11 is selectively attenuated, and the surface of the photoconductor 11. An electrostatic latent image is formed. Next, the developing device 14 develops the electrostatic latent image on the surface of the photoconductor 11, and a toner image is formed on the surface of the photoconductor 11. This toner image is transferred by the transfer unit 15 to the paper 9 supplied between the photoconductor 11 and the transfer unit 15.

  The sheet 9 on which the toner image has been transferred is conveyed toward the fixing unit 5 disposed on the downstream side of the image forming unit 4 in the sheet conveying direction. In the fixing unit 5, the paper 9 is heated and pressed by the heating member 18 and the pressure roller 19, and the toner image is melted and fixed on the paper 9. Next, the sheet 9 on which the toner image is fixed is discharged onto the discharge tray 21 by the discharge roller pair 20. After the transfer by the transfer unit 15, the toner remaining on the surface of the photoconductor 11 is removed by the cleaning unit 16, and the residual charge on the surface of the photoconductor 11 is removed by the charge eliminating unit 17. Then, the photosensitive member 11 is charged again by the charging unit 12 and image formation is performed in the same manner.

  FIG. 2 is a cross-sectional view showing a schematic configuration of the developing device 14 used in the image forming apparatus 1.

  The developing device 14 includes a developing container 22 that contains a one-component magnetic developer, and a first stirring member 23 and a second stirring member that stir and transport the developer (hereinafter, sometimes referred to as “toner”). 24, a developing roller composed of the developing sleeve 26 and the magnetic pole member 25, and a regulating member 41.

  The first and second stirring members 23 and 24 are rotatably disposed in the developing container 22 with a partition member interposed therebetween. Moreover, the 1st and 2nd stirring members 23 and 24 are provided with the screw formed helically in the axial direction. When the first and second agitating members 23 and 24 rotate, the toner is agitated, and the agitated toner is passed through the communication container provided in the partition member in the longitudinal direction (front and back of the paper surface of FIG. 2). The toner is charged by friction between the toners. Then, the toner is supplied to the developing sleeve 26 by the second stirring member 24.

  The developing sleeve 26 is formed in a cylindrical shape with a nonmagnetic material such as aluminum and incorporates a magnetic pole member 25. The developing sleeve 26 is rotatably supported in the developing container 22 at a position adjacent to the second stirring member 24. Further, the developing sleeve 26 is exposed from the opening of the developing container 22 and is opposed to the photosensitive member 11 that is an image carrier with a certain distance. A developing area D for supplying the toner carried on the developing sleeve 26 toward the photoconductor 11 is formed in the opposed area.

  The magnetic pole member 25 has a plurality of magnetic pole portions in the circumferential direction, and carries a charged toner on the surface of the developing sleeve 26 by generating a magnetic field toward the surface of the developing sleeve 26.

  The regulating member 41 regulates the toner carried on the surface of the developing sleeve 26 to a predetermined layer thickness, has a blade shape, and is located upstream of the developing region D in the rotating direction of the rotating sleeve 26 with respect to the developing region D. It is attached to the developing container 22 with a predetermined distance from the surface of 26.

  The toner supplied from the second agitating member 24 is carried on the surface of the developing sleeve 26, and the carried toner is regulated to a constant layer thickness by the regulating member 41, and is further moved to the developing flow area D by the rotation of the developing sleeve 26. It is conveyed toward. By applying a bias voltage between the developing sleeve 26 and the photosensitive member 11, the toner on the developing sleeve 26 is supplied to the photosensitive member 11 in the developing region D, and the electrostatic latent image on the photosensitive member 11 is The toner image is developed.

  Next, the stirring unit of the developing device will be described in detail with reference to FIG. FIG. 3 is a cross-sectional plan view of the stirring unit as viewed from above.

  As described above, the developing container 22 is formed with the first conveyance path 22c, the second conveyance path 22d, the partition member 22b, and the communication portions 22e and 22f.

  The partition member 22b extends in the longitudinal direction of the developing container 22 and partitions the first transport path 22c and the second transport path 22d in parallel. The right end portion in the longitudinal direction of the partition member 22b forms a communication portion 22e together with the side wall portion of the developing container 22, while the left end portion in the longitudinal direction of the partition member 22b forms the communication portion 22f together with the side wall portion of the developing container 22. Is forming. The communicating portions 22e and 22f are opened so that the toner can move between the first conveyance path 22c and the second conveyance path 22d. Therefore, the toner can circulate counterclockwise in the first conveyance path 22c, the communication part 22e, the second conveyance path 22d, and the communication part 22f.

  A first stirring member 23 is disposed in the first transport path 22c, and a second stirring member 24 is disposed in the second transport path 22d.

  The first agitating member 23 is rotatably supported by the developing container 22 by the rotating shafts 31 and 32 and extends in a spiral shape with a fixed pitch in the axial direction of the rotating shafts 31 and 32 between the first and second stirring members 27 and 28. And a rib 34 that rotates and holds the screw 33 without being eccentric with respect to the center of the rotation shaft 31 or 32 during rotation. The screw 33 and the rib 34 extend to both end portions in the longitudinal direction of the first transport path 22c, and are also provided to face the communication portion 22e and the communication portion 22f.

  The second stirring member 24 has the same configuration as the first stirring member 23. Specifically, the second agitating member 24 is rotatably supported by the developing container 22 by the rotating shafts 31 and 32, and has a constant pitch in the axial direction of the rotating shafts 31 and 32 between the flange portions 27 and 28. The screw 33 extends in a spiral shape and is formed in a hollow shape, and a rib 34 that rotates and holds the screw 33 without being eccentric with respect to the shaft centers of the rotation shafts 31 and 32 during rotation. The screw 33 and the rib 34 extend to both end portions in the longitudinal direction of the second transport path 22d, and are also provided to face the communication portion 22e and the communication portion 22f.

  When the first and second stirring members 23 and 24 are rotated in opposite directions by a drive source such as a motor or gear (not shown), the screw 33 of the first stirring member 23 rotates in the first direction. The toner is conveyed by the screw 33 while being agitated in the direction of arrow P in the first conveyance path 22c. When the toner is transported in the first transport path 22c, the agitated toner is transported satisfactorily while being dispersed around the outer edge and the hollow portion of the screw 33, and then passes through the communication portion 22e to the second. Is transported into the transport path 22d. Further, the screw 33 of the second stirring member 24 rotates in the direction opposite to the first direction, and the toner is transported while being stirred in the second transport path 22d by the screw 33 in the arrow Q direction. When the toner is transported in the second transport path 22d, the agitated toner is transported satisfactorily while being distributed around the outer edge portion and the hollow portion of the screw 33, and further through the communication portion 22f. It is conveyed to the conveyance path 22c. Thus, the toner is agitated while circulating from the first conveyance path 22c to the communication part 22e, the second conveyance path 22d, and the communication part 22f, and the agitated toner is supplied to the developing sleeve 26 (see FIG. 2). Supplied.

  Said 1st and 2nd stirring members 23 and 24 are comprised as shown in FIG. 4, FIG. 4 is a perspective view showing the first and second agitating members 23 and 24, and FIG. 5 is a side view schematically showing the first agitating member 23 taken along the plane YY of FIG. It is. 3 is a YY cross-sectional view, the screw 33 is continuously formed in a spiral shape, so that a broken line of the screw 33 appears. However, in FIG. The broken line is omitted. Since the first and second stirring members 23 and 24 have the same configuration, the first stirring member 23 will be described as a representative.

  As shown in FIG. 4, the first stirring member 23 includes a screw 33, a pair of ribs 34 and 34, disk-shaped flange portions 27 and 28, one rotating shaft 31, and the other rotating shaft 32. (Invisible behind the flange portion 28), and is integrally molded with a resin such as an ABS resin to which toner is difficult to adhere.

  One end of the screw 33 is continuously provided on the opposite surface of the one flange portion 27 where the one rotation shaft 31 is formed, and the other flange portion 28 where the other rotation shaft 32 is formed. The other end of the screw 33 is continuously provided on the opposite surface.

  The screw 33 has a spiral portion 33a formed to extend from one end side to the other end side in a spiral blade shape. The spiral portion 33a has an outer edge portion 33c having a circular shape, and an inner edge portion 33d formed with a rectangular hollow portion 33b. The spiral portion 33a is configured such that the thickness (length in the longitudinal direction) of the outer edge portion 33c is small, and the thickness increases toward the inner edge portion 33d.

  A rib 34 is formed between the mutually opposing surfaces of the adjacent spiral portions 33a, 33a. The rib 34 is formed in a substantially rectangular cross section along the inner edge portion 33d of the spiral portion 33a. A pair of ribs 34 is formed at positions symmetrical to a straight line passing through the axial centers of the rotary shafts 31 and 32. The pair of ribs 34, 34 are formed between all the surfaces of the spiral portions 33 a, 33 a facing each other, and further formed between the spiral portion 33 a on one end side and the one flange portion 27, and the other end It is formed between the spiral portion 33a on the side and the flange portion 28 on the other side.

  Note that the rib 34 is not limited to a configuration in which a pair of ribs 34a and 33a are provided between mutually facing surfaces, but when the first stirring member 23 is configured to be long in the longitudinal direction (the axial direction of the rotary shafts 31 and 32), Alternatively, when the diameter of the outer edge portion 33c of the screw 33 is configured to be relatively large, in order to ensure the strength that the screw 33 can rotate without being eccentric, the spiral portion 33a with the rotation shafts 31 and 32 as the center. Alternatively, three or more ribs 34 may be arranged at the position where the frame is equally divided. On the other hand, when the first stirring member 23 is relatively small, the rib 34 continuously extends between the one and the other flange portions 27 and 28, so that the strength of the screw 33 can be ensured. In this case, it may be constituted by one rib 34.

  As shown in FIG. 5, each rib 34 is formed in a rectangular shape having an inclined surface 34 a at one corner in a cross-sectional view. One long side portion of the rib 34 is disposed so as to overlap the inner edge portion 33 d of the spiral portion 33 a, and the short side portion is disposed so as to face the rotation direction A of the screw 33. The rib 34 is formed with an inclined surface 34a and a flat surface 34b on one short side (downstream end in the rotation direction A), and on the other short side (upstream end in the rotation direction A). A flat surface 34c is formed.

  The inclined surface 34a has an inclination angle X with respect to the rotation direction A (a direction substantially parallel to the long side portion) at the downstream end, and the inclination angle X is a predetermined angle, but an angle smaller than 45 degrees. It is preferable that it is comprised. As the screw 33 rotates in the direction of arrow A, the downstream end portion of the rib 34 circulates while contacting the toner. With the above configuration, the toner in the vicinity of the downstream end portion has the inclined surface 34 a of the rib 34. Therefore, the toner does not adhere to the ribs 34 and the toner is transported satisfactorily.

  The flat surface 34b is formed flat in a direction perpendicular to the rotational direction A at the downstream end, and has a width S in the perpendicular direction. Further, the inclined surface 34a has a width T in the perpendicular direction. The width S of the flat surface 34b of the rib 34 is configured to be smaller than the width T of the inclined surface 34a. With this configuration, the toner near the downstream end of the rib 34 is less likely to stay near the downstream end, and further moves to the upstream side in the sliding rotation direction A along the inclined surface 34a of the rib 34. The toner does not adhere to the ribs 34 and the toner is transported satisfactorily.

  The inclined surface 34 a is provided on the outer edge side of the rib 34 with reference to the axis center of the rotating shaft 31. With this configuration, when the screw 33 is rotating, the toner in the vicinity of the inclined surface 34a of the rib 34 is dragged from the inclined surface 34a by the drag from the inclined surface 34a in a direction perpendicular to the inclined surface 34a (from the screw 33). Pushed away).

  Therefore, when the first stirring member 23 rotates at a position where the first stirring member 23 faces the communication portion 22e formed on the partition member 22b (see FIG. 3), the inclined surface 34a of the rib 34 communicates. It becomes possible to oppose the part 22e. When the inclined surface 34a of the rib 34 faces the communication portion 22e, the toner in the first conveyance path 22c (see FIG. 3) is pushed toward the communication portion 22e by the inclined surface 34a of the rib 34, and the second It is conveyed to the conveyance path 22d.

  Further, when the second stirring member 24 rotates at a position where the second stirring member 24 faces the communication portion 22f formed in the partition member 22b (see FIG. 3), the inclined surface 34a of the rib 34 communicates. It becomes possible to oppose the part 22f. When the inclined surface 34a of the rib 34 faces the communication portion 22f, the toner in the second conveyance path 22d (see FIG. 3) is pushed toward the communication portion 22f by the inclined surface 34a of the rib 34, and the first It is conveyed to the conveyance path 22c.

  As described above, the toner circulates well in the first conveyance path 22c, the communication part 22e, the second conveyance path 22d, and the communication part 22f while being agitated.

  In the first embodiment, the rib 34 is provided along the inner edge 33d of the screw 33. However, the present invention is not limited to this, and the rib 34 is provided along the outer edge 33c of the screw 33. Alternatively, it may be provided between the outer edge portion 33c and the inner edge portion 33d of the screw 33, and this different form also has the same effect as the above embodiment.

  Moreover, in the said 1st Embodiment, although the rib 34 was formed in the rectangular shape by sectional view, and the inclined surface 34a was provided in the corner, this invention is not limited to this, The rib 34 is screwed. Depending on the required strength for the size of 33, the shape may be square, and the short side, the size of each long side, the ratio between the short side and the long side, etc. are appropriately set, and the ribs thus set An inclined surface 34a may be provided at the corner (corner portion).

(Second Embodiment)
FIG. 6 is a side view schematically showing screws and ribs of the stirring member according to the second embodiment. The second embodiment is different from the first embodiment in that the screw 33 is configured in a disc shape and the rib 34 is disposed inside the screw 33, and the configuration different from the first embodiment will be mainly described. Henceforth, description of the same part as 1st Embodiment is abbreviate | omitted.

  The first stirring member 23 includes a screw 33, a pair of ribs 34, 34, one flange portion 27 that partially protrudes, and the other flange portion 28 (not shown for the same configuration as the one flange portion 27). , One rotating shaft 31 and the other rotating shaft 32 (not shown because of the same structure as the one rotating shaft 31), and integrally molded with a resin such as ABS resin that is difficult to adhere to toner. Is done.

  The first and second flange portions 27 and 28 are formed so as to protrude to the opposite side with the first and second rotating shafts 31 and 32 as centers. A pair of ribs 34, 34 are provided on the projecting portions of the one and the other flange portions 27, 28 so as to extend in the axial direction of the rotating shaft 31 (the front and back direction in FIG. 6).

  A screw 33 is integrally provided on the outer edges of the pair of ribs 34. The screw 33 has a spiral portion 33a formed to extend spirally at a constant pitch in the axial direction of the rotary shaft 31, and is configured by forming a hollow portion 33b in the spiral portion 33a. Specifically, the outer edge portion 33c of the spiral portion 33a has a circular shape, the inner edge portion 33d thereof has a circular shape, and a circular hollow portion 33b is formed in the inner edge portion 33d. Both end portions of the screw 33 are integrally provided on one and the other flange portions 27 and 28, respectively. By providing the hollow screw 33 integrally with the pair of ribs 34, 34 and the one and other flange portions 27, 28, the screw 33 can rotate without being eccentric when the first stirring member 23 rotates. it can.

  The pair of ribs 34, 34 are provided in two positions symmetrical with respect to a straight line passing through the axis center of the rotating shaft 31. Each rib 34 extending in the axial direction of the rotating shaft 31 is formed in a rectangular shape in a cross-sectional view at a portion facing the spiral portion 33a of the screw 33, but between the facing spiral portions 33a and 33a. Then, in the cross sectional view, it is formed and formed in a rectangular shape having an inclined surface 34a at one corner. The long side portion of the rib 34 is provided so as to match the width of the flange portion 27, and the short side portion thereof is provided so as to face the rotation direction A of the screw 33. The rib 34 is formed with an inclined surface 34a and a flat surface 34b on one short side (downstream end in the rotation direction A), and on the other short side (upstream end in the rotation direction A). A flat surface 34c is formed.

  The inclined surface 34a has an inclination angle X with respect to the rotational direction A at the downstream end, and the inclination angle X is configured at a predetermined angle, but is preferably configured at an angle smaller than 45 degrees. As the screw 33 rotates in the direction of arrow A, the downstream end portion of the rib 34 circulates while contacting the toner. With the above configuration, the toner in the vicinity of the downstream end portion has the inclined surface 34 a of the rib 34. Therefore, the toner does not adhere to the ribs 34 and the toner is transported satisfactorily.

  The flat surface 34b is formed flat in a direction perpendicular to the rotational direction A at the downstream end, and has a width S in the perpendicular direction. Further, the inclined surface 34a has a width T in the perpendicular direction. The width S of the flat surface 34b of the rib 34 is configured to be smaller than the width T of the inclined surface 34a. With this configuration, the toner near the downstream end of the rib 34 is less likely to stay near the downstream end, and further moves to the upstream side in the sliding rotation direction A along the inclined surface 34a of the rib 34. The toner does not adhere to the ribs 34 and the toner is transported satisfactorily.

  The inclined surface 34 a is provided on the outer edge side of the rib 34 with reference to the axis center of the rotating shaft 31. With this configuration, when the screw 33 is rotating, the toner in the vicinity of the inclined surface 34a of the rib 34 is dragged from the inclined surface 34a by the drag from the inclined surface 34a in a direction perpendicular to the inclined surface 34a (from the screw 33). Pushed away).

  Therefore, when the first stirring member 23 rotates at a position where the first stirring member 23 faces the communication portion 22e formed on the partition member 22b (see FIG. 3), the inclined surface 34a of the rib 34 communicates. It becomes possible to oppose the part 22e. When the inclined surface 34a of the rib 34 faces the communication portion 22e, the toner in the first conveyance path 22c (see FIG. 3) is pushed toward the communication portion 22e by the inclined surface 34a of the rib 34, and the second It is conveyed to the conveyance path 22d. Similar to the first agitating member 23, the second agitating member 24 pushes the toner in the second conveying path 22d toward the communicating portion 22f by the inclined surface 34a of the rib 34, and conveys the toner to the first conveying path 22c. To do. As described above, the toner circulates well in the first conveyance path 22c, the communication part 22e, the second conveyance path 22d, and the communication part 22f while being agitated.

(Third embodiment)
FIG. 7 is a side view schematically showing screws and ribs of the stirring member according to the third embodiment. The third embodiment differs from the second embodiment in the configuration of the ribs 34.

  A screw 33 is integrally provided on the outer edges of the pair of ribs 34. The screw 33 has a spiral portion 33a formed to extend spirally at a constant pitch in the axial direction of the rotary shaft 31, and is configured by forming a hollow portion 33b in the spiral portion 33a. Specifically, the outer edge portion 33c of the spiral portion 33a has a circular shape, the inner edge portion 33d thereof has a circular shape, and a circular hollow portion 33b is formed in the inner edge portion 33d. Both end portions of the screw 33 are integrally provided on one and the other flange portions 27 and 28, respectively. By providing the hollow screw 33 integrally with the pair of ribs 34, 34 and the one and other flange portions 27, 28, the screw 33 can rotate without being eccentric when the first stirring member 23 rotates. it can.

  The pair of ribs 34, 34 are provided in two positions symmetrical with respect to a straight line passing through the axis center of the rotating shaft 31. Each rib 34 extending in the axial direction of the rotating shaft 31 is formed in a rectangular shape in a cross-sectional view at a portion facing the spiral portion 33a of the screw 33, but between the facing spiral portions 33a and 33a. Then, it is formed and formed in a rectangular shape in which each inclined surface 34a is provided at two corners in the sectional view. The long side portion of the rib 34 is provided so as to match the width of the flange portion 27, and the short side portion thereof is provided so as to face the rotation direction A of the screw 33. The rib 34 has two inclined surfaces 34a and a flat surface 34b formed on one short side portion (downstream end portion in the rotation direction A), while the other short side portion (upstream end portion in the rotation direction A). ) Is formed with a flat surface 34c.

  Of the two inclined surfaces 34a, one inclined surface 34a is provided on the outer edge side of the rib 34 with respect to the flat surface 34b, and the other inclined surface 34a is provided on the inner edge side of the rib 34 with respect to the flat surface 34b. Each inclined surface 34a has an inclination angle X with respect to the rotation direction A at the downstream end, and the inclination angle X is configured at a predetermined angle, but is preferably configured at an angle smaller than 45 degrees. As the screw 33 rotates in the direction of arrow A, the downstream end portion of the rib 34 circulates while contacting the toner. With the above configuration, the toner near the downstream end portion is inclined to each inclined surface of the rib 34. Since the toner moves to the upstream side in the sliding rotation direction A along 34a, the toner does not adhere to the rib 34, and the toner can be transported satisfactorily.

  The flat surface 34b is formed flat in a direction perpendicular to the rotational direction A at the downstream end, and has a width S in the perpendicular direction. Each inclined surface 34a has a width T in the perpendicular direction. The width S of the flat surface 34b of the rib 34 is configured to be smaller than the width T of each inclined surface 34a. With this configuration, the toner near the downstream end of the rib 34 is less likely to stay near the downstream end, and further moves to the upstream side in the sliding rotation direction A along the inclined surface 34a of the rib 34. The toner does not adhere to the ribs 34, and the toner can be transported satisfactorily.

  One inclined surface 34 a is provided on the outer edge side of the rib 34 with respect to the axis center of the rotating shaft 31. With this configuration, when the screw 33 is rotating, the toner in the vicinity of the one inclined surface 34 a is dragged from the inclined surface 34 a by a force perpendicular to the inclined surface 34 a toward the outer side of the screw 33 (from the screw 33. Pushed away).

  Therefore, when the first stirring member 23 rotates at a position where the first stirring member 23 faces the communication portion 22e formed on the partition member 22b (see FIG. 3), one inclined surface 34a of the rib 34 is provided. Can face the communication portion 22e. When one inclined surface 34a faces the communication portion 22e, the toner in the first conveyance path 22c (see FIG. 3) is pushed toward the communication portion 22e by the one inclined surface 34a, and the second conveyance path It is conveyed to 22d. Similar to the first agitating member 23, the second agitating member 24 pushes the toner in the second conveying path 22d toward the communicating portion 22f by the one inclined surface 34a of the rib 34, and the first conveying path 22c. Transport to. As described above, the toner circulates well in the first conveyance path 22c, the communication part 22e, the second conveyance path 22d, and the communication part 22f while being agitated.

  In the third embodiment, the configuration in which the ribs 34 having the two inclined surfaces 34a and the flat surface 34b are provided between all the spiral portions 33a and 33a facing each other is shown. Not limited to this, the inclined surface 34a formed on the outer edge side of the rib 34 of the two inclined surfaces 34a may be provided only in a portion facing the communication portions 22e and 22f.

(Fourth embodiment)
FIG. 8 is a side view schematically showing screws and ribs of the stirring member according to the fourth embodiment. The fourth embodiment differs from the second embodiment in the configuration of the ribs 34.

  A screw 33 is integrally provided on the outer edges of the pair of ribs 34. The screw 33 has a spiral portion 33a formed to extend spirally at a constant pitch in the axial direction of the rotary shaft 31, and is configured by forming a hollow portion 33b in the spiral portion 33a. Specifically, the outer edge portion 33c of the spiral portion 33a has a circular shape, the inner edge portion 33d thereof has a circular shape, and a circular hollow portion 33b is formed in the inner edge portion 33d. Both end portions of the screw 33 are integrally provided on one and the other flange portions 27 and 28, respectively. By providing the hollow screw 33 integrally with the pair of ribs 34, 34 and the one and other flange portions 27, 28, the screw 33 can rotate without being eccentric when the first stirring member 23 rotates. it can.

  The pair of ribs 34, 34 are provided in two positions symmetrical with respect to a straight line passing through the axis center of the rotating shaft 31. Each rib 34 is configured to be formed in a rectangular shape having an inclined surface 34a at one corner in a cross-sectional view. The long side portion of the rib 34 is provided so as to match the width of the flange portion 27, and the short side portion thereof is provided so as to face the rotation direction A of the screw 33. The rib 34 is formed with an inclined surface 34a and a flat surface 34b on one short side (downstream end in the rotation direction A), and on the other short side (upstream end in the rotation direction A). A flat surface 34c is formed.

  The inclined surface 34a is provided on the inner edge side of the rib 34 with respect to the flat surface 34b. The inclined surface 34a has an inclination angle X with respect to the rotational direction A at the downstream end, and the inclination angle X is configured at a predetermined angle, but is preferably configured at an angle smaller than 45 degrees. As the screw 33 rotates in the direction of arrow A, the downstream end portion of the rib 34 circulates while contacting the toner. With the above configuration, the toner near the downstream end portion is inclined to each inclined surface of the rib 34. Since the toner moves to the upstream side in the sliding rotation direction A along 34a, the toner does not adhere to the rib 34, and the toner is transported satisfactorily.

  The flat surface 34b is formed flat in a direction perpendicular to the rotational direction A at the downstream end, and has a width S in the perpendicular direction. Further, the inclined surface 34a has a width T in the perpendicular direction. The width S of the flat surface 34b of the rib 34 is configured to be smaller than the width T of the inclined surface 34a. With this configuration, the toner near the downstream end of the rib 34 is less likely to stay near the downstream end, and further moves to the upstream side in the sliding rotation direction A along the inclined surface 34a of the rib 34. The toner does not adhere to the ribs 34 and the toner is transported satisfactorily.

  In the second to fourth embodiments, the configuration in which the pair of ribs 34 and 34 are provided along the inner edge portion 33d of the screw 33 is shown, but the present invention is not limited to this, and the pair of ribs 34 and 34 is provided. You may provide along the outer edge part 33c of the screw 33, and you may provide between the outer edge part 33c and the inner edge part 33d of the screw 33, and this another form also has an effect similar to the said embodiment.

  Moreover, in the said 1st-4th embodiment, although the structure which provides the inclined surface 34a and the flat surface 34b in the downstream edge part of the rib 34 was shown, this invention is not limited to this, The downstream edge of the rib 34 The structure may be provided with only the inclined surface 34a.

  The present invention is used for an agitating member having a screw for agitating and conveying a developer used in a copying machine, a printer, a facsimile, a composite machine thereof, and the like, a developing device including the same, and an image forming apparatus including the stirring member. be able to.

DESCRIPTION OF SYMBOLS 1 Image forming apparatus 14 Developing apparatus 22 Developing container 22b Partition member 22c 1st conveyance path 22d 2nd conveyance path 22e, 22f Communication part 23 1st stirring member 24 2nd stirring member 27 One collar part 28 The other鍔 31 Rotating shaft 32 Rotating shaft 33 Rotating shaft 33 Screw 33a Spiral portion 33b Hollow portion 33c Outer edge portion 33d Inner edge portion 34 Rib 34a Inclined surface 34b Flat surface A Rotating direction S Flat surface width T Inclined surface width X Inclined angle

Claims (4)

A first conveyance path in which the developer is conveyed in a predetermined direction, and a second conveyance in which the developer is conveyed in a direction opposite to the first conveyance path and extends in parallel with the first conveyance path. A path, a partition member that partitions the first and second transport paths, and a communication in which both ends in the longitudinal direction of the partition member are opened so that the developer circulates in the first and second transport paths A developing container having a portion;
A first stirring member disposed in the first transport path;
A second stirring member disposed in the second transport path;
With
The first and second stirring members are provided to face the communication part, respectively.
Each of the first and second agitating members is spirally supported from one rotating shaft that is rotatably supported, the other rotating shaft that is rotatably supported, and from the one rotating shaft to the other rotating shaft. A screw formed by forming a hollow portion in a spiral portion formed to extend, and a rib formed between the spiral portions opposed in the longitudinal direction of the screw,
The ribs have a sloped surface inclined at a predetermined angle with respect to the rotational direction of said downstream-side end portion provided on the downstream end portion of the rotational direction,
The developing device according to claim 1, wherein the inclined surface is provided on an outer edge side of the rib with respect to an axis center of the rotating shaft . The developing device according to claim 1, wherein the inclined surface is inclined at an angle smaller than 45 degrees with respect to a rotation direction at the downstream end portion. At the downstream end of the rib, the inclined surface and a flat surface that is flat in a direction perpendicular to the rotational direction at the downstream end are formed, and the flat surface and the inclined surface are each in the perpendicular direction. The developing device according to claim 2, wherein a width of the flat surface is smaller than a width of the inclined surface. Image forming apparatus including a developing device according to any one of claims 1 to 3.

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