JP4754023B2 - Toner transport device, process cartridge, and image forming apparatus - Google Patents

Description

  The present invention relates to an image forming apparatus such as a copying machine, a printer, a facsimile, or a complex machine thereof. In particular, the present invention relates to an electrophotographic image forming apparatus for transferring a toner image formed on a photoreceptor directly or indirectly via an intermediate transfer member and recording the image on a recording medium such as a sheet / OHP film. The present invention also relates to a toner transport device that transports toner in such an image forming apparatus. Further, the present invention relates to a process cartridge that includes such a toner conveying device and that is integrated with at least a cleaning device together with a photosensitive member so as to be detachable from the image forming apparatus main body.

  In an electrophotographic image forming apparatus, after a toner image is transferred to a recording medium, the toner remaining on the photoreceptor is removed by a cleaning device, and the surface of the photoreceptor is neutralized. Yes. The residual toner removed by the cleaning device is transported from the cleaning device by the toner transport device and collected in a waste toner tank for disposal or returned to the developing device for recycling.

  Some toner conveying devices include a toner conveying member in a pipe and convey the toner in the axial direction of the toner conveying member through the pipe by rotating the toner conveying member. As the toner conveying member, there are a screw-like member and a spiral-like member, but from the viewpoint of cost, a spiral member having no core shaft is preferable.

  For example, a toner having a spiral toner conveying member in a pipe, a spiral second toner conveying member in a second pipe, the pipe and the second pipe being connected, and the toner conveyed through the pipe by the toner conveying member Was continuously conveyed through the second pipe by the second toner conveying member, and the toner removed by the cleaning device was conveyed to a waste toner tank or a developing device at the target site.

  However, although the spiral toner conveying member without a core shaft is inexpensive, the length varies greatly, and the length varies depending on the posture in the pipe such as the curve, and the downstream end reaches the pipe outlet. There was a case where it was not or it protruded greatly from the pipe exit.

  For example, if the downstream end of the toner conveying member does not reach the outlet of the pipe, the toner conveying force is reduced when the downstream end is passed, and toner blocking occurs at the connecting position of the pipe and the second pipe, thereby causing toner clogging. Become. On the other hand, if the downstream end of the toner conveying member protrudes from the outlet of the pipe, it interferes with, for example, the second pipe or the second toner conveying member, causing troubles during assembly. When a waste toner tank or shutter is provided at the pipe outlet, the downstream end of the toner conveying member interferes with the waste toner tank or shutter.

  SUMMARY OF THE INVENTION Accordingly, a first object of the present invention is to provide a toner conveying device that does not cause toner clogging or interference with other parts even if the length of the toner conveying member varies.

  A second object of the present invention is to provide a toner conveying device that stably rotates a toner conveying member.

  A third object of the present invention is to provide a toner conveyance device that conveys a toner conveyance path without aggregation of toner.

  A fourth object of the present invention is to provide a toner conveying device that suppresses vibration due to rotation of a toner conveying coil.

  A fifth object of the present invention is to prevent the downstream end of the toner carrying coil from being caught by the length regulating member when the toner carrying coil is rotated.

  A sixth object of the present invention is to provide a toner conveying device that can reliably convey toner to the downstream end of the toner conveying path forming member even when the load is large.

  A seventh object of the present invention is to provide a toner conveying device that does not cause toner clogging or interference with other parts at a pipe connecting position.

  An eighth object of the present invention is to provide a toner conveying device that is less likely to cause toner clogging at a pipe connecting position.

  A ninth object of the present invention is to provide a toner conveying apparatus that is less likely to cause toner clogging by shortening the portion where the toner conveying force is reduced.

  A tenth object of the present invention is to provide a toner conveying apparatus that reduces the number of parts and reduces the cost.

  By the way, in a toner transport device that includes a toner transport member in a pipe that is a toner transport path forming member and transports toner through the pipe with the toner transport member, the toner transport member scrapes off the toner adhering to the inner peripheral wall of the pipe. Since the toner drops, there is little possibility that the toner adheres to the inner peripheral wall and causes toner clogging.

  However, at the connection position near the outlet of the pipe, the toner is normally free-falling to the second pipe or the like by gravity, so there is no member that actively scrapes off the toner adhering to the inner peripheral wall of the pipe, and the toner is clogged. It is easy to generate. If toner clogging occurs, for example, when a process cartridge including the toner conveying device is taken out, toner spillage may occur.

  For this reason, some conventional image forming apparatuses provide a stirring member near the outlet of the pipe to scrape off toner adhering to the inner peripheral wall of the pipe. However, even if a stirring member is used, it is difficult to completely scrape off the toner adhering to the inner peripheral wall, and if toner having high adhesion is used, there is a high possibility that toner clogging will occur.

  In some cases, the downstream end of the toner conveying member protrudes from the outlet of the pipe to scrape off toner adhering to the inner peripheral wall near the outlet of the pipe. However, in this case, as described above, interference occurs with the second pipe, the second toner conveying member, and the like, resulting in trouble during assembly. In addition, there is a possibility that a large amount of toner is placed in the vicinity of the connection position of the toner conveying member, and toner spills may occur when the process cartridge is taken out.

  Furthermore, there is a type in which a shutter is provided at the outlet of the pipe to reduce toner spillage when the process cartridge is attached or detached. However, even in this case, since the shutter member is required, not only the number of parts is increased, but there is a possibility that a large amount of toner spilled on the shutter when the process cartridge is attached / detached may leak to the outside.

  Accordingly, an eleventh object of the present invention is to reduce the amount of toner remaining in the vicinity of the outlet of the pipe and prevent toner spillage from the vicinity of the outlet when a process cartridge or the like equipped with a toner conveying device is taken out.

  The twelfth object of the present invention is to further reduce the amount of toner remaining in the vicinity of the circular outlet of the pipe, and to prevent toner spillage from the vicinity of the outlet when a process cartridge equipped with a toner conveying device is taken out. is there.

  A thirteenth object of the present invention is to provide a toner conveying device that can easily regulate the length by increasing the elasticity of the toner conveying member.

  A fourteenth object of the present invention is to provide a process cartridge provided with a toner conveying device that does not cause toner clogging or interference with other parts even if the length of the toner conveying member varies.

  A fifteenth object of the present invention is to provide an image forming apparatus provided with a toner conveying device that does not cause toner clogging or interference with other parts even if the length of the toner conveying member varies.

According to a first aspect of the present invention, there is provided a toner conveying device for conveying toner through a toner conveying path forming member by a toner conveying coil.
The toner transport path forming member is provided outside a cleaning case provided facing the photoconductor in the longitudinal direction of the photoconductor,
The toner transport coil is wound around the entire length of the coil shaft in the cleaning case on the upstream side in the toner transport direction, and the downstream side in the toner transport direction is provided in the toner transport path forming member outside the cleaning case .
The coil shaft has a shape of an impeller that, when rotated, causes the toner that has entered the toner conveying coil to fly around.

According to a second aspect of the invention, the third object described above is also to achieve, in the toner conveying device according to claim 1, wherein the coil axis in cross section is cross-shaped, characterized in that.

  The coil shaft plays the role of an impeller and repels the toner that has entered the hollow portion at the center of the coil.

According to a third aspect of the present invention, in the toner conveying device according to the first or second aspect , the coil shaft is made of a resin material .

According to a fourth aspect of the present invention, in the toner conveyance device according to any one of the first to third aspects, the toner conveyance path forming member is curved and the curved toner conveyance path forming member is within the curved area. The toner conveyance path is not provided with the coil shaft.

According to a fifth aspect of the present invention, in the toner conveying device according to the fourth aspect , the downstream side of the toner conveying coil is provided in a toner conveying path in the curved toner conveying path forming member. It is characterized by.

According to a sixth aspect of the present invention, in order to achieve the thirteenth object described above, in the toner conveying device according to any one of the first to fifth aspects, the toner conveying coil is formed with a flat plate material in a spiral shape. It is characterized by.

When the toner conveying coil is pressed against the length regulating member, it is bent with a small force.

According to a seventh aspect of the present invention, in order to achieve the fourteenth object described above, in the process cartridge, a cleaning device for removing toner remaining on the photosensitive member, and a toner removed by the cleaning device are conveyed. The toner conveying device according to any one of 1 to 6 is provided.

  Then, the toner removed by the cleaning device provided inside is transported to a waste toner tank, a developing device or the like by the toner transport device.

According to an eighth aspect of the present invention, in order to achieve the fifteenth object, in the image forming apparatus, a cleaning device that removes toner remaining on the photosensitive member, and a toner that is removed by the cleaning device are conveyed. Item 7. A toner conveying device according to any one of Items 1 to 6 , comprising the toner conveying device.

  Then, the toner removed by the cleaning device is conveyed to a waste toner tank, a developing device or the like by the toner conveying device.

According to the present invention, the toner transport coil is wound around the coil shaft, and the coil shaft has an impeller shape that, when rotated, causes the toner that has entered the toner transport coil to fly around . Blocking can be prevented by preventing toner aggregation at the upstream position. In addition, in an image forming apparatus that employs a toner recycling system, the aggregated toner returned to the developing device can be used for development as it is without the need for a step of pulverizing the aggregated toner or a classification step. Further, even if the toner conveyance path is formed in an R shape in the toner conveyance device so that the toner is more likely to aggregate than in the linear conveyance, it is possible to reduce the toner aggregation at the upstream position of the toner conveyance coil to reduce the downstream position. However, toner aggregation can be more effectively prevented.

According to the sixth aspect of the present invention, when the toner carrying coil is pressed against the length regulating member, the toner carrying coil is deflected with a small force. Therefore, the elasticity of the toner carrying coil is enhanced and the length regulation is facilitated. Can do.

According to the invention described in claim 7, the toner removed by the cleaning device provided therein, it carries to and waste toner tank and the developing device with toner conveying device, toner length of the toner conveying coil in the natural length regulating the length by deflecting the toner transporting coil length regulating member as the length protruding from the downstream end of the transport path forming member, even if variations in the length of the toner conveying coil, toner clogging and other components It is possible to provide a process cartridge including a toner conveying device that does not cause interference with the toner.

According to the eighth aspect of the present invention, the toner removed by the cleaning device is conveyed to a waste toner tank, a developing device, or the like by the toner conveying device. Therefore, the length is regulated by bending the toner conveying coil. In addition, it is possible to provide an image forming apparatus including a toner conveying device that does not cause toner clogging or interference with other components even if the length of the toner conveying coil varies.

1 is a schematic configuration diagram of a main part in an image forming apparatus according to the present invention. 2 is a longitudinal sectional view of a cleaning device provided in the image forming apparatus. FIG. FIG. 2 is an external perspective view of a toner conveying device provided in the image forming apparatus. FIG. 3 is a longitudinal sectional view taken along line AA of the toner conveying device. FIG. 6 is a partial perspective view of a toner transport coil provided in the toner transport device. FIG. 6 is a perspective view of a length regulating member provided in the toner conveying device. It is a perspective view which shows the other example of a process cartridge. FIG. 6 is a longitudinal sectional view of the process cartridge near the back side plate of the cartridge case. FIG. 8 is a perspective view showing a state where the developing device is removed from the process cartridge shown in FIG. 7. FIG. 3 is a perspective view showing the developing device as well as the photosensitive member as viewed from the opposite direction. It is an expansion perspective view of the edge part on the back side. It is an external appearance perspective view of the cleaning apparatus with which the process cartridge shown in FIG. 7 is equipped. It is a longitudinal cross-sectional view of the cleaning device. The rear side part of the coil axis | shaft which wound the toner conveyance coil with which the cleaning apparatus is equipped is shown, (A) is a partial perspective view of the state which attached the coil drive gear, (B) is a partial perspective view of the state which removed. It is. FIG. 6 is a front view of a front side portion of a coil shaft around which a toner conveying coil is wound. It is a figure which shows distance L1 from the level | step difference formed in the external shape of a coil axis | shaft to the length control member, and the natural length L2 of the small diameter part of a toner conveyance coil. FIG. 4 is a cross-sectional view of a boundary portion between a cleaning device and a toner transport device. FIG. 4 is a perspective view of a front end portion of a toner conveying coil. FIG. 6 is a cross-sectional view of another example of the toner conveying device. FIG. 6 is a view of the outlet of the pipe of the toner conveying device as viewed from the outside. FIG. 10 is a cross-sectional view of still another example of the toner conveying device. FIG. 6 is a view of the outlet of the pipe of the toner conveying device as viewed from the outside.

The best mode for carrying out the present invention will be described below with reference to the drawings.
FIG. 1 shows a schematic configuration of a main part of an image forming apparatus according to the present invention.

  Reference numeral 10 in the figure denotes a drum-shaped photoconductor that rotates counterclockwise in the figure. In the illustrated example, a drum shape is used, but a belt-shaped photoconductor may be used. Around the photoconductor 10, a developing device 12, a transfer device 13, a cleaning device 14, a static elimination device (not shown), and the like are provided in the rotational direction from the charging device 11 on the photoconductor 10. A writing device 15 is provided on the charging device 11.

  A recording medium conveyance path 16 is provided below the photosensitive member 10 to convey the recording medium from the left to the right in the drawing while passing between the transfer device 13.

  At the beginning of the recording medium conveyance path 16, for example, a medium cassette 17 is provided outside the image forming apparatus main body. In the medium cassette 17, recording media such as paper and OHP film are stacked and stored. And the supply roller 18 is provided in the feeding part. A pair of registration rollers 19 is provided along the recording medium conveyance path 16 at a position downstream of the supply roller 18 and upstream of the photoreceptor 10 and the transfer device 13.

  A fixing device 22 including a heating roller 20 and a pressure roller 21 is provided along the recording medium conveyance path 16 at a downstream position of the photoconductor 10 and the transfer device 13. A pair of discharge rollers 23 is disposed at the downstream position. A discharge tray 24 is provided downstream of the discharge roller 23 and attached to the image forming apparatus main body.

  As the photoconductor 10 rotates, the surface of the photoconductor 10 is first charged uniformly by applying a bias voltage by the charging device 11, and then exposed by the writing device 15 to perform writing so that the surface of the photoconductor 10 is electrostatically charged. A latent image is formed. Subsequently, toner is attached by a developing roller 25 provided in the developing device 12, and the electrostatic latent image is visualized to form a toner image on the photoreceptor 10.

  On the other hand, as the photosensitive member 10 rotates, the supply roller 18 rotates to feed the recording medium out of the medium cassette 17, put into the recording medium conveyance path 16, and abut against the registration roller 19 to stop. Then, the registration roller 19 is rotated in synchronization with the toner image on the photoconductor 10, conveyed through the recording medium conveyance path 16, and the recording medium is fed between the photoconductor 10 and the transfer device 13.

  Between the photoconductor 10 and the transfer device 13, the transfer device 13 transfers the above-described toner image formed on the photoconductor 10 to the recording medium.

  The recording medium after transfer of the toner image is put into the fixing device 22 through the recording medium conveyance path 16, and heat and pressure are applied by the heating roller 20 and the pressure roller 21 to fix the transferred image. The fixed recording medium is discharged out of the image forming apparatus main body by the discharge roller 23 and stacked on the discharge tray 24.

  After the toner image is transferred, the photoconductor 10 is rotated and the transfer residual toner remaining on the surface is removed by the cleaning device 14, and then the surface is neutralized by a neutralization device (not shown) to prepare for the image formation again.

  By the way, in this example, a process unit such as a charging device 11, a developing device 12, a cleaning device 14, and a static eliminator (not shown) is provided in one cartridge case together with the photoreceptor 10, and is integrated into the main body of the image forming apparatus. On the other hand, a process cartridge that is detachable in a lump is configured. As a result, the entire system is reduced in size, and individual defects can be dealt with by repairing or replacing the process cartridge, thereby improving maintainability.

  Of course, the process cartridge need not be provided with all the process devices such as the charging device 11, the developing device 12, the cleaning device 14, and the static elimination device (not shown) together with the photosensitive member 10. The at least cleaning device 14 may be provided integrally with the photoconductor 10.

  As shown in FIG. 2, the cleaning device 14 in the illustrated example attaches a blade holder 32 to a cartridge case 31 of the process cartridge 30, supports the proximal end of the cleaning blade 33 with the blade holder 32, and supports the distal end of the cleaning blade 33. Press against the outer peripheral surface of the photoreceptor 10. A base end of a resin film 34 such as Mylar (registered trademark) film is attached to the cartridge case 31, and the tip is lightly pressed against the outer peripheral surface of the photoconductor 10. A toner conveying coil 35 is rotatably provided at the bottom in the cartridge case 31.

  Then, along with the rotation of the photoconductor 10, the toner remaining on the photoconductor 10 is scraped off by the cleaning blade 33, and the scraped toner is removed while the resin film 34 prevents the scraped toner from falling off. It is stored in the cartridge case 31. The toner stored in the cartridge case 31 is collected on one side of the cleaning device 14 by the toner conveying coil 35, discharged to the outside of the cartridge case 31 by a toner conveying device according to the present invention described later, and conveyed to a waste toner tank for disposal. Or transported to the developing device 12 for recycling.

  3 and 4 show a toner conveying device 40 provided in the image forming apparatus shown in FIG. FIG. 3 is a perspective view showing the appearance of the toner conveying device 40, and FIG. 4 is a longitudinal sectional view taken along the line AA.

  Reference numeral 30 in the figure denotes a process cartridge. From one side of the process cartridge 30, the pipe 41 protrudes, curves and extends downward, and the downstream end opens in the axial direction to form an outlet. In the pipe 41, one end portion of the above-described toner conveying coil 35 in the cartridge case 31 enters as it is. The toner transport coil 35 functions as a toner transport member.

  For example, as illustrated in FIG. 5, the toner conveying coil 35 is formed by forming an elongated flat plate material into a spiral shape. Thereby, stretchability is improved and length regulation mentioned later is made easy. In the illustrated example, the entire toner transport coil 35 is formed to be extendable and contractible, but only a part thereof may be formed to be extendable and contractable in the length direction. When no external force is applied, the tip of the toner transport coil 35 protrudes several millimeters from the downstream end of the pipe 41 that is a toner transport path forming member.

  A length regulating member 42 is attached to the outlet at the downstream end of the pipe 41. The length regulating member 42 is made of a plate material having a circular toner passage hole 43 such as a stainless steel plate having a thickness of 0.3 mm, for example, as shown in FIG. The diameter of the toner passage hole 43 is made smaller than the outer diameter of the toner transport coil 35. Then, the length of the toner conveying coil 35 is made constant by being pressed and bent.

  In such a pipe 41, a second pipe 44, which is a second toner conveyance path forming member, is disposed below and connected, and an outlet thereof communicates with an inlet of the second pipe 44. A second toner conveying member 45 is provided in the second pipe 44. As the second toner conveying member 45, a screw-shaped or spiral-shaped member is used, and is provided to be rotatable around the core axis. In the illustrated example, a waste toner tank 46 is connected to the outlet of the second pipe 44.

  When the toner in the cleaning device 14 is transported to the waste toner tank 46 using the illustrated toner transport device 40, the toner transport coil 35 and the second toner transport member 45 as toner transport members are driven by a drive source (not illustrated). , The toner discharged to the outside of the cartridge case 31 is conveyed through the pipe 41 by the toner conveying coil 35, passes through the toner passage hole 43 of the length regulating member 42, and enters the second pipe 44. Then, the second toner conveying member 45 continuously conveys the toner through the second pipe 44 and enters the waste toner tank 46. When the waste toner tank 46 becomes full of toner, only the toner in the tank or in the tank is discarded.

  As described above, in the illustrated example, the length of the toner conveying coil 35 as the toner conveying member is regulated by pressing the toner conveying coil 35 provided in the pipe 41 against the length regulating member 42 provided at the downstream end of the pipe 41. Therefore, in a natural state where no external force is applied, the length of the toner transport coil 35 is set to a length protruding from the downstream end of the pipe 41, and the length of the toner transport coil 35 is regulated by the length regulating member 42. To do. Even if the length of the toner transport coil 35 varies, the toner transport coil 35 can be provided up to the full downstream end of the pipe 41, and toner clogging can be prevented from occurring by preventing the toner transport force from decreasing. .

  Even if the length of the toner transport coil 35 varies, the tip of the toner transport coil 35 does not protrude from the downstream end of the pipe 41, so that the second pipe 44, the second toner transport member 45, etc. provided at the outlet of the pipe 41, etc. The possibility of causing interference with other parts can be eliminated.

  In addition, the second pipe 44 is connected to the pipe 41, and the toner transported by the toner transport coil 35 through the pipe 41 is continuously transported by the second toner transport member 45 through the second pipe 44. The possibility of causing toner clogging and interference with other parts can be eliminated. An outlet is provided at the downstream end of the pipe 41 in the axial direction, and the outlet is brought close to the inlet of the second pipe 44 so that the toner can be delivered at the shortest distance.

  Further, at the connecting position of the pipe 41 and the second pipe 44, the toner transported by the toner transport coil 35 through the upper pipe 41 is put into the lower second pipe 44 by gravity, and the second pipe 44 is continuously passed through the second pipe 44. Since the toner is transported by the toner transport member 45, the portion without the toner transport coil 35 at the pipe connection position transports the toner using gravity, and the possibility of causing toner clogging can be further reduced.

  Further, since the toner transported by the toner transport coil 35 is transported, for example, into the second pipe 44 through the toner passage hole 43 of the plate-like length regulating member 42, the toner transport coil 35 is not provided with a thin plate shape. The portion where the toner conveying force is reduced is shortened only when passing through the toner passage hole 43 of the length regulating member 42, and the toner conveying coil 35 for forcibly conveying the toner is provided almost close to the outlet of the pipe 41. Further, the risk of toner clogging can be further reduced.

Next, FIG. 7 shows another example of the process cartridge 30.
In this example, the drum-shaped photoconductor 10 is attached to the cartridge case 31 of the process cartridge 30 so as to be rotatable in the direction of the arrow in the figure. A developing device 12 and a cleaning device 14 are provided around the photoconductor 10 with the photoconductor 10 interposed therebetween. On the cleaning device 14 side, a toner conveying device 40 is provided that protrudes from the front side plate 36 of the cartridge case 31 and curves downward.

  FIG. 8 shows a longitudinal section of the process cartridge 30 near the back side plate 37 of the cartridge case 31.

  Reference numeral 50 in the drawing denotes a geared flange provided at the rear side end of the photoreceptor 10. The geared flange 50 rotates in the clockwise direction in the drawing, and by the rotation, the toner conveying coil 35 that is a toner conveying member wound around the straight coil shaft 52 in the cleaning case 51 is driven counterclockwise. Rotate. The entrance of the cleaning case 51 faces the photoreceptor 10 and presses the front end of the cleaning blade 33 from below and the front end of the resin film 34 from above to the peripheral surface of the photoreceptor 10.

  A lubricant application brush 53 is provided downstream of the cleaning device 14 in the rotation direction of the photoconductor 10. A solid lubricant 55 is pressed against the lubricant application brush 53 by an urging member 54. Then, the lubricant application brush 53 is rotated with the rotation of the photosensitive member 10, and the lubricant scraped from the lubricant 55 is applied to the surface of the photosensitive member 10. Further, a charging roller 11 is provided at a position downstream of the lubricant application brush 53 in the rotation direction of the photoconductor 10. A charging roller cleaner 56 for cleaning the surface is pressed against the charging roller 11.

  FIG. 9 shows a state in which the developing device 12 is removed from the process cartridge 30 shown in FIG. FIG. 10 shows a state in which the photoconductor 10 is also removed together with the developing device 12. FIG. 11 is an enlarged view of the rear side end of FIG.

  As can be seen from FIG. 11, on the inner surface of the back side plate 37 of the cartridge case 31, there are a first idler gear 57 that meshes with the geared flange 50, and a second idler gear that meshes with the first idler gear 57 and is covered with the cover member 58. Is supported rotatably. A second idler gear (not shown) meshes with a coil drive gear 60 (described later) fixed on the coil shaft 52 described above. Then, the rotation of the geared flange 50 is transmitted to the coil drive gear 60 via the first idler gear 57 and the second idler gear, and the coil shaft 52 is rotated.

FIG. 12 shows the appearance of the cleaning device 14.
In FIG. 12, reference numeral 51 is a cleaning case, 33 is a cleaning blade, 34 is a resin film, 60 is a coil drive gear, 40 is a toner transport device, and 41 is a toner transport path forming member. It is a pipe. The tip of the pipe 41 is closed with a length regulating member 42 having a toner passage hole 43. As can be seen from FIG. 12, the length regulating member 42 is not formed as a separate member from the pipe 41, but is formed integrally with the pipe 41 with the pipe material itself.

FIG. 13 shows a longitudinal section of the cleaning device.
In FIG. 13, similarly, reference numeral 51 is a cleaning case, 60 is a coil drive gear, 52 is a coil shaft, 35 is a toner conveying coil, 40 is a toner conveying device, and 41 is a pipe. The pipe 41 is formed by combining two semi-cylindrical members each having one of the length regulating members 42 divided into two. Then, the toner transport coil 35 is provided in the pipe 41, and the toner transport coil 35 is pressed against a plate-like length regulating member 42 provided at the downstream end of the pipe 41 so that the length of the toner transport coil 35 is constant. Become.

FIG. 14 shows the back side end of a straight coil shaft 52 around which the upstream portion of the toner conveying coil 35 is wound.
The coil shaft 52 is made of a resin material and has a substantially cross-shaped cross section in this example, and has a D-shaped cross section at the back side as shown in FIG. And as shown to (A), it supports by the slide bearing 61 and it fixes so that it may not slip | deviate. The coil shaft 52 and the toner conveying coil 35 are positioned with respect to the cleaning case 51 via the slide bearing 61.

  Here, if the toner conveying coil 35 is simply provided in the cleaning case 51, the toner staying in the hollow portion at the center of the coil is aggregated. As a result, the toner is conveyed as a lump, and the degree of aggregation is increased downstream. It tends to cause blocking. In addition, in an image forming apparatus that employs a toner recycling method, the aggregated toner returned to the developing device 12 cannot be used as it is for development, and a process for pulverizing the aggregated toner, a classification process, and the like must be provided. Therefore, in this example, by using the coil shaft 52 having a substantially cross-shaped cross section, the coil shaft 52 acts as an impeller and repels the toner that has entered the hollow portion at the center of the coil, thereby aggravating the degree of aggregation. The toner can be transported by the toner transport coil 35 without being caused.

  In particular, in this example, in order to reduce the size, the pipe 41 of the toner conveying device 40 into which the downstream portion of the toner conveying coil 35 enters is curved so that the toner conveying path in the pipe 41 has an R shape. By rubbing the toner conveying coil 35 on the toner, the toner is more likely to aggregate than in the case of linear conveyance. However, as described above, the toner conveying coil 35 is disposed around the impeller-shaped coil shaft 52 having a substantially cross-shaped cross section at the upstream position of the toner conveying coil 35, and the toner aggregates in the cleaning case 51. By reducing this, toner aggregation can be prevented more effectively at the downstream position as well.

  Further, the D-shaped section of the coil shaft 52 is inserted into the D-shaped hole at the center of the coil drive gear 60, and the coil drive gear 60 is fixed on the coil shaft 52 so as not to be relatively rotatable as shown in FIG. Thus, when rotation is transmitted to the coil drive gear 60, the rotation is transmitted to the coil shaft 52, the coil shaft 52 is rotated together with the toner transport coil 35, and the toner in the cleaning case 51 is transported to the front side. .

  The toner conveying coil 35 is a flat plate made of stainless steel and formed in a spiral shape so as to be freely stretchable in the length direction, and has an inner diameter that is slightly larger than the shaft diameter of the coil shaft 52. Then, when the front end of the coil shaft 52 is inserted and the coil shaft 52 is almost inserted into the toner transport coil 35, the toner transport coil 35 is brought into contact with the claw 62 on the coil shaft 52 and along the inclination of the claw 62. As a result of the deformation, the toner carrying coil 35 sequentially climbs over the two claws 62 and is prevented from being pulled out by the claws 62 when it has passed over. The toner conveying coil 35 is formed by bending the rear end 63 as shown in FIG. 5B, and the toner conveying coil 35 is rotated together with the coil shaft 52 by hooking the end 63 on the stepped portion 64 of the coil shaft 52. To do.

FIG. 15 shows the front side of the coil shaft 52 around which the toner conveying coil 35 is wound.
Incidentally, as shown in FIG. 15, the coil shaft 52 is formed such that the front side end has a slightly small diameter and a step 65 is formed on the outer shape. In accordance with this, the outer diameter of the toner conveying coil 35 is also made smaller to make the inner diameter slightly smaller.

  FIG. 16 shows a distance L1 from the step 65 formed on the outer shape of the coil shaft 52 to the length regulating member 42, and a natural length L2 of the portion where the inner diameter of the toner conveying coil 35 is reduced, that is, the small diameter portion 66.

  If L1 <L2 including the tolerance, the tip of the toner transport coil 35 is pressed against the length regulating member 42. Note that the small diameter portion 66 of the toner conveying coil 35 enters the curved pipe 41, so that the stress is reduced by shortening the pitch. Of course, the pitch may be shortened over the entire length, but this is not preferable in terms of cost.

  However, in order to facilitate the length regulation by the length regulating member 42, when the elasticity of the toner carrying coil 35 is weakened and the elasticity is increased, the toner carrying coil 35 carries the toner to the front side. When the load increases, the tip of the toner transport coil 35 is immediately pushed to the back side. At this time, if there is no step 65 and the inner diameter of the toner conveying coil 35 is not made small, the total length of the toner conveying coil 35 is reduced and the tip of the toner conveying coil 35 is separated from the length regulating member 42. . For example, when the total length of the toner transport coil 35 is 400 mm, even if the toner transport coil 35 is shrunk by 4 mm, it is only 1%. Therefore, the repulsive force hardly occurs, and the toner transport coil 35 is greatly deflected with a small load.

  Therefore, when the step 65 is formed in the coil shaft 52 and the inner diameter of the toner transport coil 35 is made small, the small diameter portion 66 of the toner transport coil 35 hits the step 65 so that only a part of the toner transport coil 35 is contracted by the load. Even when the load is the same, the repulsive force is increased to reduce the amount of deflection of the toner conveying coil 35 so that the tip of the toner conveying coil 35 is not easily separated from the length regulating member 42.

FIG. 17 shows a cross section of the boundary portion between the cleaning device 14 and the toner transport device 40.
As shown in the figure, a ring-shaped tunnel member 67 is fixed to the inlet of the pipe 41 of the toner conveying device 40. The inner diameter of the tunnel member 67 is made slightly larger than the outer diameter of the small diameter portion 66 of the toner transport coil 35. Then, the front end of the coil shaft 52 around which the toner carrying coil 35 is wound is passed through the tunnel member 67.

  The downstream portion of the toner conveying coil 35 is curved because it passes through the curved pipe 41, and is easily shaken when rotated. Therefore, by passing not only the toner conveying coil 35 but also the coil shaft 52 through the tunnel member 67, the most downstream end of the coil shaft 52 is supported without play by the tunnel member 67 along with the toner conveying coil 35. The toner conveying coil 35 that has passed through the tunnel member 67 is positioned by the pipe 41 through the pipe 41. The outer diameter of the downstream portion of the toner conveying coil 35, that is, the curved small diameter portion 66 is slightly smaller than the inner diameter of the pipe 41.

FIG. 18 shows a front end portion of the toner conveying coil 35.
As shown in the drawing, the front end of the toner conveying coil 35 is bent and bent inward to form a bent portion 68. Thus, the apex 69 of the bent portion 68 is pressed against the length regulating member 42 to prevent the toner conveying coil 35 from being caught by the length regulating member 42. Further, the front end of the toner transport coil 35 is opposite to the rotation direction of the toner transport coil 35, and the front end of the toner transport coil 35 is allowed to escape even if the front end is likely to be caught by the length regulating member 42. The tip is caught.

  In this example, as described above, the pipe 41 is formed by combining two semi-cylindrical members each having one of the length regulating members 42 divided into two. If it does in this way, a resin mold can be made cheap. However, it is unavoidable that a minute step is generated in the divided part of the length regulating member 42 due to the molding variation within the dimensional tolerance. Therefore, in particular, as in this example, a type in which a toner conveyance path forming member such as a pipe 41 is formed by combining two semi-cylindrical members each having one of the length regulating members 42 divided into two. The catching of the toner conveying coil 35 is a serious problem. Forming the inwardly bent portion 68 at the front end of the toner conveying member 35 is particularly effective in such a type.

FIG. 19 shows another example of the toner conveying device 40. FIG. 20 is a view of the outlet of a pipe 41 that is a toner transport path forming member of the toner transport device 40 as viewed from the outside.
In the toner transport device 40 of this example, a circular curved pipe 41 is used as a toner transport path forming member, and a toner transport coil 35 that transports toner by rotating through the pipe 41 as a toner transport member. Is used. A length regulating member 42 that presses the toner conveying coil 35 is formed to project inward from the inner peripheral wall at the circular outlet of the pipe 41. Although the number is one in the illustrated example, a plurality may be formed.

  When the toner conveying coil 35 is rotated in the pipe 41, the tip 70 which is the downstream end of the coil 35 gets over the length regulating member 42 at least once every rotation, and the length of the toner conveying coil 35 is increased every time it gets over. It expands and contracts in the vertical direction, and the reaction causes vibration to drop toner on the toner conveying coil 35 and the vicinity of the circular outlet of the pipe 41. Therefore, the amount of toner remaining near the circular outlet of the pipe 41 can be reduced, and toner spillage from the vicinity of the outlet can be prevented when taking out a process cartridge or the like equipped with the toner conveying device 40.

  For example, if the tip 70 of the toner transport coil 35 is deformed so as to be strongly hooked to the length regulating member 42, the amount of expansion and contraction of the toner transport coil 35 is increased to increase the reaction, and the toner transport coil 35 can be further increased. The amount of toner remaining near the circular outlet of the pipe 41 can be reduced by dropping toner near the circular outlet of the pipe 41.

FIG. 21 shows still another example of the toner conveying device 40. FIG. 22 is a view of the outlet of the pipe 41 that is a toner transport path forming member of the toner transport device 40 as viewed from the outside.
Similarly, in the toner conveying device 40 of this example, a circular curved pipe 41 is used as a toner conveying path forming member, and a toner conveying coil 35 that conveys toner by rotating in the pipe 41 is used as a toner conveying member. Use. The length regulating member 42 that presses the toner conveying coil 35 is formed so as to cross the circular outlet of the pipe 41 in the radial direction. Although the number is one in the illustrated example, a plurality may be formed intersecting each other.

  In this way, when the toner conveying coil 35 is rotated in the pipe 41, the tip 70, which is the downstream end of the coil 35, gets over the length regulating member 42 at least twice every rotation, and every time it gets over the toner conveying coil. 35 is expanded and contracted in the length direction, and the reaction causes vibration to drop toner on the toner conveying coil 35 and in the vicinity of the circular outlet of the pipe 41. Therefore, the amount of toner remaining near the circular outlet of the pipe 41 can be further reduced, and toner spillage from the vicinity of the outlet can be prevented when the process cartridge including the toner conveying device 40 is taken out.

  In fact, even if the process cartridge is removed from the main body of the image forming apparatus after image formation is performed using the process cartridge having the toner conveying device 40 shown in FIGS. 19 to 22, no toner spills and toner clogging occurs. There wasn't.

  By the way, in the above-described example, the case where the toner image formed on the photoconductor 10 is directly transferred to form an image on a recording medium is described. However, as a matter of course, the toner image formed on the photosensitive member is once transferred to a drum-like or belt-like intermediate transfer member, and then the toner image on the intermediate transfer member is transferred to form an image on a recording medium. The same can be applied to the forming apparatus. In this case, the present invention is not limited to the case of transporting the toner of the primary cleaning device from which the residual toner on the photosensitive member has been removed, but also to the case of transporting the toner of the secondary cleaning device from which the residual toner on the intermediate transfer member has been removed. Can do.

  In the above-described example, the case where the present invention is applied to an image forming apparatus that forms a monochromatic image on a recording medium has been described. However, the image forming apparatus of a revolver type (rotary type) or a tandem type that forms a color image is similarly described. Can be applied. For example, when a plurality of photoconductors are provided and a cleaning device is provided for each photoconductor as in a tandem type image forming apparatus, the toner conveying device according to the present invention can be provided in each cleaning device. A plurality of process cartridges according to the present invention can be provided.

  In the illustrated example described above, the pipe 41 is connected to the waste toner tank 46 via the second pipe 44, but the pipe 41 may be directly connected to the waste toner tank 46. At this time, the toner conveying coil 35 is formed to be extendable and contracted, while a length regulating member 42 is provided at the downstream end of the pipe 41 and pressed against the length regulating member 42 to regulate the length of the toner conveying coil 35. However, the same effect can be achieved, and for example, the possibility of causing interference with the waste toner tank 46 can be eliminated. When a shutter is provided on a component provided downstream of the pipe 41, it is possible to eliminate the possibility of causing interference with the shutter.

DESCRIPTION OF SYMBOLS 10 Photoconductor 12 Developing device 14 Cleaning device 30 Process cartridge 35 Toner conveyance coil (toner conveyance member)
40 Toner transport device 41 Pipe (toner transport path forming member)
42 Length regulating member 43 Toner passage hole 44 Second pipe 45 Second toner conveying member 46 Waste toner tank 52 Coil shaft 65 Step of coil shaft 67 Tunnel member 68 Bending portion

JP 2000-284594 A JP 2001-109343 A Japanese Patent Laid-Open No. 11-84968 JP 2000-284660 A

Claims (8)

In a toner transport device that transports toner through a toner transport path forming member by a toner transport coil,
The toner transport path forming member is provided outside a cleaning case provided facing the photoconductor in the longitudinal direction of the photoconductor,
The toner transport coil is wound around the entire length of the coil shaft in the cleaning case on the upstream side in the toner transport direction, and the downstream side in the toner transport direction is provided in the toner transport path forming member outside the cleaning case .
The toner conveying device according to claim 1, wherein the coil shaft has an impeller shape that, when rotated, causes the toner that has entered the toner conveying coil to fly around.   The toner conveying device according to claim 1, wherein the coil shaft has a substantially cross-shaped cross section.   The toner conveying device according to claim 1, wherein the coil shaft is made of a resin material.   4. The toner transport path forming member is curved, and the coil shaft is not provided in the toner transport path in the curved toner transport path forming member. The toner conveying device according to any one of the above.   The toner conveying device according to claim 4, wherein a downstream side of the toner conveying coil is provided in a toner conveying path in the curved toner conveying path forming member.   6. The toner conveying device according to claim 1, wherein the toner conveying coil is formed by forming a flat plate material into a spiral shape.   A process cartridge comprising: a cleaning device that removes toner remaining on a photoconductor; and a toner transport device according to any one of claims 1 to 6 that transports toner removed by the cleaning device. A cleaning device for removing toner remaining on the photosensitive member, characterized in that it comprises a toner conveying device according to any one of claims 1 to 6 for transporting the toner removed by the cleaning device, an image forming apparatus .

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