JP2023137893A - Development apparatus - Google Patents

Abstract

To provide a screw-type development apparatus which is suitable for reduction of the size and the torque and increase of the rate.SOLUTION: A development apparatus 10 agitates a developer by circulating the developer back and forth by an agitation conveyance member 11, and charges the developer. The agitation conveyance member 11 includes: an axis 13 of rotation; and double cylinders 15, 18 which rotate around the axis 13 of rotation. The double cylinders 15, 18 include the cylinder 18 close to the axis 13 of rotation and the cylinder 15 less close to the axis 13 of rotation and convey the developer in opposite directions.SELECTED DRAWING: Figure 1

Description

The present invention relates to a developing device having a screw that can circulate developer in the longitudinal direction.

In conventional developing devices, one-point replenishment is the mainstream in order to simplify the toner replenishment mechanism. However, the disadvantage of this is that a method of sufficiently "uniforming the developer in the longitudinal direction" is required within the developing device, and as a result, two screws are provided in the longitudinal direction to circulate the developer. Such a conventional developing device is described in, for example, Japanese Patent Laid-Open No. 06-051634 (Patent Document 1). Although the configuration is different from that of Patent Document 1, FIG. 11 shows a perspective view of a developing device in which two conventional screws are provided to circulate the developer. Referring to FIG. 11, a conventional developing device 50 has two screws 51 arranged in parallel and a developing roll 52 arranged in parallel to the two screws 51. The developer is circulated and conveyed toward the side edges.

Japanese Patent Application Publication No. 06-051634

A conventional developing device was configured as described above. Since it has a configuration in which two screws are provided in the vertical direction, there is a problem in that it is necessary to secure space in the vertical direction. In addition, a wide variety of screw conveyors have been proposed, mainly for civil engineering, but they cannot be made into shape without using metal welding, etc., are not suitable for mass production, are expensive, and cannot be copied. There was a problem in that there was no screw feeder that was small and suitable for high speed and low torque like the machine.

This invention was made to solve the above-mentioned problems, and it is an object of the present invention to provide a screw type developing device that is small and suitable for high speed and low torque.

The developing device according to the present invention uses an agitation conveying member to reciprocate the developer and agitate and charge the developer. The stirring and conveying member includes a rotating shaft and a double cylinder that is provided to rotate around the rotating shaft, and the double cylinder includes a cylinder that surrounds the rotating shaft and a side that is close to the rotating shaft, and a cylinder that covers the circumference of the rotating shaft and a cylinder that is close to the rotating shaft. The developer is transferred in the opposite direction between the outside of the cylinder on the side close to the rotation axis and the inside of the cylinder on the side far from the rotation axis, and the outside of the cylinder on the side far from the rotation axis. Transport to.

Preferably, the double tube includes an inner tube provided on the rotating shaft side and an outer tube provided outside the inner tube, and is provided between the inner tube and the outer tube, It includes a first helical screw having a predetermined winding direction, and a second helical screw provided outside the outer cylinder and having a winding direction opposite to that of the first helical screw.

More preferably, the first and second helical screws each include a plurality of unit screws divided by a width of one period of the first and second helices, and the plurality of unit screws are arranged on the rotating shaft. inserted and concatenated.

The first helical screw and the second helical screw of the unit screw may have the same rotational pitch in the rotational axis direction.

It is preferable that the PL is provided at the center of the pleated portions of the first helical screw and the second helical screw of the unit screw.

The unit screw may have uneven portions on both sides so that the rotational directions of the unit screw are aligned.

In one embodiment of the present invention, the outer cylinder and the second helical screw are not provided at the conveyance start portion of the first helical screw.

In another embodiment of the present invention, the outer tube and the first helical screw are not provided at the conveyance start portion of the second helical screw.

According to this invention, the double cylinder provided around the rotating shaft is rotated around the rotating shaft, thereby reciprocating the developer in opposite directions and transporting the developer.

As a result, it is possible to provide a screw type developing device that is small and suitable for high speed and low torque.

The above-mentioned objects, other objects, features and advantages of the present invention will become more apparent from the detailed description of the embodiments given below with reference to the drawings.

FIG. 1 is a side perspective view of a developing device according to an embodiment of the present invention. FIG. 2 is a perspective view showing the stirring and conveying member shown in FIG. 1. FIG. FIG. 3 is a cross-sectional perspective view of the outer cylinder shown in FIG. 2 taken in the direction of the rotation axis. FIG. 4 is a perspective view showing one unit of the unit screw shown in FIG. 3 as viewed from its axial direction. FIG. 2 is a perspective view of the front helical screw seen from the front side in the axial direction. FIG. 3 is a cross-sectional view of the front helical screw and the rear helical screw taken in the X direction. FIG. 3 is a cross-sectional view of the front helical screw and the rear helical screw taken in the Y direction. It is a perspective view which shows the mold|type which forms the left half divided by PL of a unit screw. It is a figure which shows the state where the unit screw is arrange|positioned so that the axis may become horizontal. It is a perspective view which shows the mold|type which forms the right half divided by PL of a unit screw. It is a figure explaining the movement of a development. It is a schematic diagram which shows the whole 1st and 2nd helical screw which comprises a stirring conveyance member, and the detail of both ends. In FIG. 10A, it is a figure which shows typically the structure of one unit screw shown by 10B. FIG. 10A is a diagram schematically showing an axial cross section indicated by 10C in FIG. 10A. In FIG. 10A, it is a diagram schematically showing the configuration of the connecting portion of two adjacent unit screws indicated by 10D. FIG. 2 is a perspective view of a conventional developing device in which two screws are provided to circulate developer.

Hereinafter, one embodiment of the present invention will be described in detail with reference to the drawings. FIG. 1 is a side perspective view of a developing device 10 according to an embodiment of the present invention. Referring to FIG. 1, a developing device 10 according to an embodiment of the present invention includes an agitation conveyance member 11 that conveys a developer (not shown) while stirring the same, and an agitation conveyance member 11 that is arranged parallel to the agitation conveyance member 11. The developer roller 12 includes a developing roll 12, and the developer is attracted to a photoreceptor drum (not shown) via the developing roll 12. The stirring and conveying member 11 is rotated by a rotating shaft 13.

FIG. 2 is a perspective view showing the stirring and conveying member 11 shown in FIG. 1, and FIG. 3 is a cross-sectional perspective view of the stirring and conveying member 11 shown in FIG. 2, cut in the direction of the rotation axis. Referring to FIGS. 2 and 3, the stirring and conveying member 11 includes a rotating shaft 13 and a double cylinder provided to rotate around the rotating shaft 13, and rotates around the rotating shaft 13. As a result, unillustrated debris is conveyed in mutually opposite directions between the inner tube 18 surrounding the rotating shaft 13 and the outer tube 15 on the far side, and on the outside of the outer tube 15.

That is, with reference to FIGS. 2 and 3, the stirring conveyance member 11 is rotated by a rotating shaft 13 and includes an outer cylinder 15 extending in the axial direction and a second helical screw provided outside the outer cylinder 15. 16, and inside the outer cylinder 15 there is an inner cylinder 18 which is rotated by the rotating shaft 13 and extends in the axial direction; A possible first helical screw 19 is provided. The first helical screw 19 is connected (adhered) to the inner tube 18 and the outer tube 15.

Further, the outer cylinder 15 and the second helical screw 16 and the inner cylinder 18 and the first helical screw 19 are divided into equal lengths in the axial direction by the dividing line 17, and a plurality of divided unit screws 21 The stirring and conveying member 11 is formed by.

In other words, the first and second helical screws 19 and 16 each include a plurality of unit screws 21 divided by the width of one period of the first and second helices, and the plurality of unit screws 21 A rotating shaft 13 is inserted and connected to the inside of the inner cylinder 18. Further, the first helical screw 19 and the second helical screw 16 of the unit screw 21 have the same rotation pitch in the rotation axis direction.

In addition, in FIG. 3, the conveyance direction of the unillustrated debt is indicated by an arrow. The debris is conveyed to the left side in the figure by a second helical screw 16 formed on the outer tube 15, and conveyed to the right side in the figure by a first helical screw 19 formed on the inner tube 18.

That is, in this embodiment, the first helical screw 19 and the second helical screw 16 have different spiral winding directions, so when the rotating shaft 13 rotates, they rotate in opposite directions. The developer is transported in opposite directions.

FIG. 4 is a perspective view showing one unit of the unit screw 21 shown in FIG. 3 as viewed from its axial direction. The unit screw 21 includes a front screw portion 25 and a rear screw portion 26, and the front screw portion 25 is provided on the outer tube 15 shown in FIG. 2 and on the outside of the outer tube 15, respectively. The inner cylinder 18 includes a second helical screw 16 provided inside the outer cylinder 15 , an inner cylinder 18 provided inside the outer cylinder 15 , and a first helical screw 19 provided outside the inner cylinder 18 . A cavity 28 is provided inside, and a rotating shaft 13 (not shown) is provided therein.

[First embodiment]
Furthermore, a PL (Parting Line) 23 is formed at the center of the tip of the pleated portion 31 constituting the second helical screw 16 of the front screw portion 25, as shown by a dotted line in the figure.

Although not shown, the rear screw portion 26 also has a similar configuration.

Next, the front screw portion 25, which is one half of the unit screw 21 shown in FIG. 4, will be described. FIG. 5 is a perspective view of the front screw portion 25 viewed from the front side in the axial direction. Referring to FIG. 5, the front screw portion 25 includes a second helical screw 16 provided on the outer periphery of the outer cylinder 15 and a second helical screw 16 provided on the inside of the outer cylinder 15, as shown in FIG. It includes an inner cylinder 18 and a first helical screw 19 provided outside the inner cylinder 18, and a cavity 28 is provided inside the inner cylinder 18, and a rotation shaft (not shown) is provided therein. It will be done.

Moreover, in FIG. 5, PL23 seen from the axial direction is shown by a dotted line. As shown in FIG. 5, the PL 23 is provided along the inner tube 18, the first helical screw 19, the outer tube 15, and the second helical screw 16.

Next, the front screw portion 25 and the rear screw portion 26, which are formed separately at the PL 23, will be explained. 6 is a sectional view of the front screw portion 25 and the rear screw portion 26 taken in the X direction, and FIG. 7 is a sectional view of the front screw portion 25 and the rear screw portion 26 taken in the Y direction. FIG. Here, the X direction is a cross-sectional view of the unit screw 21 indicated by the arrow XX in FIG. 5, taken along a plane passing through the center of its rotating shaft, and the Y direction is The directions are perpendicular to each other.

Referring to FIGS. 6 and 7, PL23 is indicated by a dotted line. Here, too, the molds used are a cavity (fixed mold) and a core (movable mold), which are used for normal plastic molding, and these are combined to form a cavity. By injecting plastic, a molded product of the unit screw 21 shown in FIG. 4 etc. is completed. Note that in FIGS. 6 and 7, arrows indicate the direction in which the cores 36a and 36b are removed. Further, in the description of this embodiment, illustration of the cavity is omitted.

As shown in FIGS. 6 and 7, by extracting the core 36a on the front side and the core 36b on the rear side, the front screw portion 25 and the rear screw portion 26 separated by the PL 23 are formed. By joining these with PL23, one unit screw 21 is formed.

Next, a mold for forming the unit screw 21 will be explained. FIG. 8A is a perspective view showing the core 36b forming the left half of the unit screw 21 divided by the PL 23, and FIG. 8B is a view showing the unit screw 21 arranged so that its axis is horizontal. 8C is a perspective view showing the core 36a forming the right half of the unit screw 21 divided at the PL23. That is, one unit screw 21 shown in FIG. 8B is formed by the screw parts formed by the core 36b shown in FIG. 8A and the core 36a shown in FIG. 8C.

As described above, in this embodiment, the outer second helical screw 16 and the inner first helical screw 19 are formed by reversing each other, and the units constituting each are formed by one pitch of the helical screw. By doing the following, it was possible to mold a developing device having a double structure spiral screw.

Next, the movement of the developer 33, which is powder, in this embodiment will be explained. FIG. 9 is a diagram illustrating the movement of the developer 33 in this embodiment. Referring to FIG. 9, when the first helical screw 19 rotates and lifts up the debe 33 placed on the first helical screw 19 of the unit screw 21, the mass of the debe 33 collapses and slides down in the advancing direction. When the angle of repose of the debe 33 exceeds the angle of repose (the angle when the debe 33 is piled up in a free state without falling over), the mass of the debe 33 collapses and is pushed out to the right in the figure while circulating.

Next, both ends of the stirring and conveying member 11 having a double-layer spiral screw in this embodiment will be explained. FIG. 10A is a schematic diagram showing details of the entire first and second helical screws 19 and 16 constituting the stirring and conveying member 11 and both ends thereof. Here, a configuration in which a plurality of unit screws 21 are combined is shown, and the rotating shaft 13 is shown by a dotted line. 10B is a diagram schematically showing the configuration of one unit screw 21 indicated by 10B in FIG. 10A, and FIG. 10C is a schematic diagram showing a cross section in the axial direction indicated by 10C in FIG. 10A. , FIG. 10D is a diagram schematically showing the configuration of the connecting portion of two adjacent unit screws 21 indicated by 10D in FIG. 10A.

FIG. 10A shows the moving direction of the debt (not shown) that is conveyed by the second helical screw 16 provided on the outer periphery of the outer cylinder 15 and the first helical screw 19 provided on the outer periphery of the inner cylinder 18. Indicated by an arrow. As shown in FIG. 10A, the unillustrated debt is conveyed to the right between the inner tube 18 and the outer tube 15, and is conveyed to the left outside the outer tube 15.

Referring to FIG. 10A, the first helical screw 19 located at the left end of the rotating shaft indicated by 13a in the figure is located at its transport start portion (where the developer is between the outer tube 15 and the inner tube 18). One of the first helical screws 19 provided in the inner tube 18 may be made larger in the radial direction without providing a periphery of the outer tube 15 (portion to be transported).

Similarly, the second helical screw 16 located at the right end of the rotating shaft indicated by 13b in the figure also has a transport start portion (a portion where the developer is transported to the outer cylinder 15) around the outer cylinder 15. It is not necessary to provide

Referring to FIG. 10B, the unit screw 21 includes an outer cylinder 15, a second helical screw 16 formed outside the outer cylinder 15, an inner cylinder 18, an inner cylinder 18 and an outer cylinder. 15 and a first helical screw 19 formed between the first helical screw 19 and

Referring to FIG. 10C, the axial cross section of the stirring and conveying member 11 has a double cylindrical structure, each having a helical screw. That is, it has a first helical screw 19 provided outside the inner tube 18 and a second helical screw 16 provided outside the outer tube 15.

[Second embodiment]
Referring to FIG. 10D, two adjacent unit screws 21 have a concave portion 22b on one side and a convex portion 22a on the other side, whereby the plurality of unit screws 21 are connected in succession. Note that the uneven portions 22a and 22b may be provided on the inner tube 18 or on the outer tube 15. In this way, the concavo-convex portions 22a and 22b formed by adjacent resin parts can be fitted into each other, and can also serve as a slip-out locking mechanism.

In the above embodiment, the first helical screw provided between the inner tube and the outer tube is in contact with the inner periphery of the outer tube, but the present invention is not limited to this. The first helical screw may be independent of the outer cylinder without contacting the inner circumference.

As described above, according to this embodiment, the developing device is configured with a double-structured screw including a first helical screw and a second helical screw centered on the rotating shaft, and the inside of the screw and Since the external winding direction is reversed, it is possible to provide a screw type developing device that is small and suitable for high speed and low torque.

The invention may be embodied in various other forms without departing from its spirit or essential characteristics. Therefore, the above-described embodiments are merely illustrative and should not be interpreted in a limiting manner. All modifications and changes that come within the scope of equivalents of the claims of the present invention are intended to be within the scope of the present invention.

According to the present invention, it is possible to provide a screw-type developing device that is small and suitable for high speed and low torque, and is thus useful as a developing device.

10 Developing device 11 Agitating and conveying member 12 Developing roll 13 Rotating shaft 15 Outer tube 16 Second spiral screw 17 Parting line 18 Inner tube 19 First spiral screw 21 Unit screw 23 PL (Parting Line)
25 Front screw part 26 Rear screw part 28 Cavity 31 Fold part 33 Deve 36a, 36b Core

Claims (8)

A developing device that uses an agitation conveying member to reciprocate developer and agitate and charge the developer,
The agitation conveyance member includes a rotating shaft;
including a double cylinder provided to rotate around the rotation axis,
The double cylinder includes a cylinder that surrounds the rotation axis and a cylinder that is closer to the rotation axis and a cylinder that is farther from the rotation axis,
Conveying the developer in opposite directions between the outside of the cylinder on the side closer to the rotation axis and the inside of the cylinder on the side far from the rotation axis, and the outside of the cylinder on the side farther from the rotation axis, Developing device. The double cylinder includes an inner cylinder provided on the rotating shaft side and an outer cylinder provided outside the inner cylinder,
a first helical screw provided between the inner tube and the outer tube and having a predetermined winding direction;
The developing device according to claim 1, further comprising a second helical screw provided outside the outer cylinder and having a winding direction opposite to that of the first helical screw. The first and second helical screws each include a plurality of unit screws divided by a width of one period of the first and second helices, and the plurality of unit screws are connected to the rotating shaft. The developing device according to claim 2, wherein the developing device is inserted and connected. The developing device according to claim 3, wherein the first helical screw and the second helical screw of the unit screw have the same rotation pitch in the direction of the rotation axis. The developing device according to claim 3, wherein a PL is provided at the center of pleated portions of the first helical screw and the second helical screw of the unit screw. 4. The developing device according to claim 3, further comprising uneven portions on both sides of the unit screw so that rotational directions of the unit screw are aligned. 3. The developing device according to claim 2, wherein the outer cylinder and the second helical screw are not provided at a transport start portion of the first helical screw. 3. The developing device according to claim 2, wherein the outer cylinder and the first helical screw are not provided at a transport start portion of the second helical screw.

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