JP3973594B2 - Drum unit, process cartridge, and image forming apparatus - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a drum unit having an image bearing drum, a process cartridge having the drum unit, and an image forming apparatus having the drum unit or the process cartridge.
[0002]
[Prior art]
In an image forming apparatus configured as an electronic copying machine, a printer, a facsimile, or a complex machine thereof, an image carrying drum on which a toner image is formed is used. The image bearing drum is configured as a photosensitive drum on which a toner image is formed on the surface by a developing device, or an intermediate transfer drum on which the toner image is transferred. Since such an image bearing drum vibrates due to an external vibration force applied thereto, abnormal noise is generated from the image bearing drum. For example, in the case of an image bearing drum made of a photosensitive drum, a charging device or a cleaning blade is in contact with the outer peripheral surface thereof, but the charging device vibrates due to the influence of an AC voltage applied to the charging device, Further, since the cleaning blade vibrates due to a stick slip accompanying the rotation of the image bearing drum, these vibrations are transmitted to the image bearing drum, and the image bearing drum vibrates and generates noise, which may cause discomfort to the user. There is. Further, in the case of an image carrying drum composed of an intermediate transfer drum, the image carrying drum may vibrate due to the vibration of a device in contact therewith, and abnormal noise may be generated.
[0003]
Therefore, conventionally, a damping member is inserted inside the image bearing drum, and the drum unit is configured by the image bearing drum and the damping member, and the vibration of the image bearing drum is suppressed by the damping member, thereby suppressing abnormal noise generation. The structure which does is employ | adopted (for example, refer patent document 1).
[0004]
On the other hand, in recent years, for the purpose of protecting the environment and further resource saving, the appearance of a product with excellent recyclability is demanded, and the same is required for the image bearing drum. In order to improve the recyclability of a product composed of a plurality of parts, it is necessary to configure each part of a used product so that it can be easily disassembled, and to make it easy to reuse or recycle each disassembled part. However, since the damping member inserted into the image bearing drum is fixed to the image bearing drum, the work of removing the damping member from the image bearing drum is not easy, and the recyclability is poor. .
[0005]
[Patent Document 1]
JP-A-10-97158 (5th page, FIG. 4)
[0006]
[Problems to be solved by the invention]
SUMMARY OF THE INVENTION An object of the present invention is to eliminate the above-mentioned conventional drawbacks, and to provide a drum unit and a process capable of easily attaching the vibration damping member to the inside of the image bearing drum and easily removing the vibration damping member from the image bearing drum An object is to provide a cartridge and an image forming apparatus.
[0007]
[Means for Solving the Problems]
In order to achieve the above object, the present invention inserts an image bearing drum into the image bearing drum through an opening at one end in the axial direction of the image bearing drum, and is mounted inside the image bearing drum. A damping member that is disengaged from the opening on the other end side in the axial direction of the image bearing drum to the outside of the image bearing drum, and a flange that is fitted to the opening at each end in the axial direction of the image bearing drum. The vibration member has a cylindrical portion having an outer peripheral surface fixed to the inner peripheral surface of the image bearing drum, and an end wall integrally provided on the front end side of the cylindrical member in the moving direction of the vibration damping member. In addition, a chamfered portion is formed at the edge of the end wall on the inner peripheral surface side of the image carrying drum, and when the vibration damping member is inserted or removed, an external force is applied to the end wall of the vibration damping member by the bias member. And is configured to move in the image bearing drum, and the biasing member serves as an image bearing member. A support shaft that supports the drum is used, a large-diameter portion is provided in a longitudinal intermediate portion of the support shaft, and a hole having a diameter larger than that of the support shaft is formed in an end wall of the vibration damping member. When the damping member is inserted and removed, the end wall of the damping member is inserted into the hole formed in the end wall of the damping member by the large-diameter portion provided on the supporting shaft in a state where the supporting shaft is inserted. The vibration damping member is moved in the axial direction of the image carrying drum while elastically deforming at least a part of the vibration damping member in a direction to reduce the diameter, and the vibration damping member and the support shaft are connected to the image carrying drum. A drum unit is proposed in which the image bearing drum is supported by the support shaft through the flanges fitted to the openings at the respective axial ends of the image bearing drum in a state of being disposed inside. (Claim 1).
[0008]
At this time, it is advantageous that the damping member is held inside the image carrying drum by being pressed against the inner peripheral surface of the image carrying drum by the elasticity of the damping member.
[0009]
In the drum unit according to claim 1 or 2, it is advantageous that the vibration damping member is configured to be fixed to the inner peripheral surface of the image bearing drum by an adhesive (claim 3).
[0010]
The drum unit according to any one of claims 1 to 3, wherein when the damping member is moved in the image bearing drum so as to be detached from the image bearing drum, the axial direction of the image bearing drum is determined. It is advantageous that the flange attached to the opening on the other end side is pressed by the damping member so that the flange is detached from the image bearing drum.
[0011]
Further, in the drum unit according to any one of claims 1 to 4, it is advantageous that the flange is fitted and held on the image bearing drum by press-fitting or clearance fitting (claim 5).
[0012]
The drum unit according to any one of claims 1 to 5, wherein the flange includes a first flange member that fits into an opening on the other end side in the axial direction of the image bearing drum, and a first flange member. A second flange member that fits and presses the first flange member against the inner peripheral surface of the image bearing drum; When moved in the carrier drum, the front end surface of the vibration damping member abuts only on the second flange member of the first flange member and the second flange member and presses the second flange member It is advantageous if it is configured to do so (claim 6).
[0013]
In order to achieve the above object, according to the present invention, the drum unit according to any one of claims 1 to 6 and at least one image forming device for forming a toner image on an image bearing drum of the drum unit are provided. And a process cartridge that is detachably attached to the main body of the image forming apparatus.
[0014]
In order to achieve the above object, the present invention proposes an image forming apparatus comprising the process cartridge according to claim 7 (claim 8).
[0015]
In order to achieve the above object, the present invention proposes an image forming apparatus comprising the drum unit according to any one of claims 1 to 6 (claim 9).
[0016]
In the image forming apparatus according to claim 8 or 9, a toner image is formed on the image bearing drum with toner having an outflow start temperature measured by a flow tester method of 102 ° C. or lower, and a loss tangent tan δ is 0.5. It is advantageous to use a vibration damping member made of the above substances (claim 10).
[0017]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below in detail with reference to the drawings.
[0018]
FIG. 1 is a schematic cross-sectional view showing an example of an image forming apparatus having an image carrying drum 2 on which a toner image is formed. The image carrying drum 2 shown here is a cylinder made of a conductive metal such as aluminum. The photosensitive drum is provided with a photosensitive layer on the outer peripheral surface of a tube. The image bearing drum 2 is rotatably supported with respect to the case 19 of the process cartridge 18 and is driven to rotate clockwise in FIG. 1 by a drive motor (not shown). At this time, the charging device including the charging roller 20 rotatably supported by the case 19 rotates while being in contact with the outer peripheral surface of the image carrying drum 2, and a charging voltage is applied to the charging roller 20, whereby the image carrying is performed. The surface of the drum 2 is charged with a predetermined polarity.
[0019]
The surface of the image bearing drum 2 after charging is irradiated with a modulated laser beam L emitted from an exposure device (not shown) provided separately from the process cartridge 18, and thereby electrostatically is applied to the image bearing drum. A latent image is formed. The electrostatic latent image is visualized as a toner image by the developing device 22, and the toner image is carried on a transfer medium 8 which is carried on the transfer belt 8 and conveyed in the direction of arrow A. Transfer is performed by the action of the transfer brush 9 as an example. The toner image transferred to the recording medium P is fixed on the recording medium P by a fixing device (not shown). Further, the toner remaining on the image bearing drum after the toner image is transferred is removed by the cleaning brush 29 and the cleaning blade 30 of the cleaning device 27.
[0020]
The developing device 22 includes a developing case 23 constituted by a part of the case 19 of the process cartridge 18 and a developing roller 24 rotatably supported by the developing case 23, and developer D is accommodated in the developing case 23. Has been. The developer D is carried on the rotating developing roller 24 and conveyed, and the electrostatic latent image is visualized by the conveyed developer. Here, a dry two-component developer having toner and carrier is used as a developer, and when a decrease in the toner concentration of the developer is detected, the toner is replenished from the toner container 33.
[0021]
The cleaning device 27 also has a cleaning case 28 constituted by a part of the case 19 of the process cartridge 18, and the cleaning brush 29 and the cleaning blade 30 are supported on the cleaning case 28. The toner collected from the image carrying drum 2 is returned to the toner container 33 through the toner conveyance tube 31 connected to the case 19.
[0022]
FIG. 2 is a longitudinal sectional view of the image bearing drum 2, and flanges 3 and 3 </ b> A are fitted into openings at respective end portions in the axial direction of the image bearing drum 2 shown here. 3A is rotatably supported by the case 19 (FIG. 1), so that the image bearing drum 2 is rotatably supported by the case 19. Either one of the flanges 3 or 3A may be omitted, or both of the flanges may be omitted, and each end of the image bearing drum 2 may be directly supported by the case 19 so as to be freely rotatable. When it is necessary to identify these flanges 3 and 3A, one flange 3 is referred to as a first flange and the other flange 3A is referred to as a second flange.
[0023]
A gear 5 is integrally formed on the outer peripheral portion of the second flange 3A, and a mating gear (not shown) is engaged with the gear 5 and the rotation of a drive motor (not shown) is also transmitted through these gears via the second gear. Is transmitted to the flange 3A. Further, the rotation of the flange 3A is transmitted to the image bearing drum 2, and the image bearing drum 2 rotates about its central axis. As shown in FIG. 3, a notch 6 is formed at the end of the image bearing drum 2, and a protrusion 7 projecting from the second flange 3A is fitted into the notch 6, whereby the second flange 3A and the second flange 3A are fitted. Relative rotation with the image bearing drum 2 is prohibited, and rotation of the second flange 3 </ b> A is transmitted to the image bearing drum 2.
[0024]
The flanges 3, 3 </ b> A may be press-fitted into the openings at the respective ends of the image bearing drum 2 or may be fixed to the image bearing drum 2 with an adhesive. It can also be fitted and held. In the case of a clearance fit, a thrust stopper (not shown) is provided to prevent the flanges 3 and 3A from moving outward in the axial direction of the image bearing drum 2 and coming off the drum 2. It is necessary to press 3,3A. As the thrust stopper, the side wall of the case 19 shown in FIG. 1 can also be used.
[0025]
By the way, as shown in FIG. 1, the charging roller 20 and the cleaning blade 30 are in contact with the outer peripheral surface of the image bearing drum 2, respectively. A charging voltage in which a DC voltage and an AC voltage are superimposed on the charging roller 20 is applied. When applied, the charging roller 20 vibrates due to the application of the AC voltage. Further, when the image carrying drum 2 rotates, the cleaning blade 30 causes stick-slip to vibrate. These vibrations are transmitted to the image bearing drum 2, thereby causing the image bearing drum 2 to vibrate, and abnormal noise is generated when the vibration becomes intense.
[0026]
Therefore, a damping member 4 is arranged inside the image bearing drum 2 of this example as shown in FIGS. The vibration damping member 4 illustrated here has a cylindrical portion 17 having an outer peripheral surface 14 fixed to the inner peripheral surface of the image bearing drum 2 and an end wall 10, and the longitudinal sectional shape thereof is substantially U. It is formed in a letter-shaped cup shape. The end opposite to the end wall 10 is an open end that is open.
[0027]
The damping member 4 can be made of an appropriate material such as an elastic body or rigid body such as rubber, resin, metal, or a composite material thereof.
[0028]
Further, the damping member 4 having an outer diameter slightly smaller than the inner diameter of the image bearing drum 2 may be used, and the damping member 4 may be fixed to the inner peripheral surface of the image bearing drum 2 with an adhesive. A damping member 4 having an outer diameter slightly larger than the inner diameter of the image bearing drum 2 before being inserted into the drum 2 is used, and when this is inserted into the image bearing drum 2, the damping member 4 is reduced in diameter. The vibration damping member 4 may be fixed to the image bearing drum 2 by being elastically deformed in the direction so that the vibration damping member 4 is pressed against the inner peripheral surface of the image bearing drum 2.
[0029]
In this way, the damping member 4 mounted inside the image bearing drum 2 is held inside the image bearing drum 2 by being pressed against the inner peripheral surface of the image bearing drum 2 by the elasticity of the damping member. Alternatively, it is fixed to the inner peripheral surface of the image bearing drum 2 with an adhesive. The damping member 4 may be fixed to the inner peripheral surface of the image bearing drum 2 by the action of both the elasticity of the damping member 4 and the adhesive.
[0030]
Since the damping member 4 as described above is provided inside the image bearing drum 2, the damping member 4 suppresses the vibration of the image bearing drum 2 and effectively suppresses the generation of abnormal noise. Is done.
[0031]
In the image forming apparatus of this example, the image bearing drum 2, the damping member 4 mounted therein, and the pair of flanges 3 and 3A constitute an integral drum unit 34. Thus, the flanges 3 and 3A can be omitted. The drum unit has at least an image bearing drum and a vibration damping member.
[0032]
Further, in the image forming apparatus of this example, the drum unit 34 and an image forming device such as the charging roller 20, the developing device 22 and the cleaning device 27 disposed around the drum unit 34 are integrally assembled. Although configured, an image forming device configuring the process cartridge 18 can be appropriately selected. In short, the process cartridge includes a drum unit and at least one image forming device for forming a toner image on an image bearing drum of the drum unit, and the process cartridge is detachable from the main body of the image forming apparatus. Installed. The image forming apparatus of this example includes the process cartridge 18 or the drum unit 34 thereof.
[0033]
When the image bearing drum 2 deteriorates with time and reaches the end of its life, the process cartridge 18 shown in FIG. 1 is removed from the image forming apparatus main body, and a new process cartridge is set. The process cartridge 18 removed from the image forming apparatus main body is regenerated. That is, the image carrier drum 2 is removed from the case 19 of the process cartridge 18, the image carrier drum 2 and the parts assembled to the image carrier drum 2 are disassembled, and parts that can be reused as they are are reused as they are. After being subjected to predetermined processing, it is used for reuse.
[0034]
Here, in order to improve the recyclability of the image bearing drum 2, the damping member 4 and the flanges 3 and 3A assembled thereto, these can be easily assembled and disassembled by the following method.
[0035]
4 and 5 are cross-sectional views showing an example of a method for attaching the vibration damping member 4 to the image bearing drum 2. In the example shown here, first, the image bearing drum 2 to which the flanges 3 and 3A are not attached is prepared. As shown in FIG. 4, the damping member 4 is formed in the opening 11 at one end in the axial direction of the image bearing drum 2. The end walls 10 are opposed to each other. In the example shown in FIGS. 4 and 5, the damping member 4 is made of an elastic material such as rubber, and the outer diameter of the damping member 4 before being inserted into the image bearing drum 2 is the inner diameter of the image bearing drum 2. It is assumed that it is set slightly larger than the above.
[0036]
In the state shown in FIG. 4, the bar-like biasing member 13 is inserted from the open end side of the damping member 4 into the cylindrical portion 17 of the damping member 4 as indicated by an arrow B, and the biasing member 13 is brought into contact with the end wall 10 of the damping member 4, and the biasing member 13 is pushed in the direction of arrow B, that is, the axial direction of the image bearing drum 2. As a result, the damping member 4 is pushed into the image bearing drum 2 as shown in FIG. 5 and moves to the position shown in FIG. Next, the urging member 13 is pulled in the direction opposite to the arrow B, and the urging member 13 is extracted from the image carrying drum 2. In this way, the damping member 4 whose outer diameter before being inserted into the image bearing drum 2 is slightly larger than the inner diameter of the image bearing drum 2 is easily inserted into the image bearing drum 2, and this is inserted into the image bearing drum 2. Can be attached to.
[0037]
The damping member 4 mounted in the image carrier drum 2 is fixed by the outer peripheral surface 14 of the cylindrical portion 17 being pressed against the inner peripheral surface of the image carrier drum 2 due to its elasticity. Next, first and second flanges 3 and 3A are respectively attached to the opening 11 on one end side in the axial direction of the image bearing drum 2 and the opening 12 on the other end side as shown in FIG. The image bearing drum 2 is used by being assembled in the case 19 shown in FIG.
[0038]
The outer peripheral surface 14 of the vibration damping member 4 can be fixed to the inner peripheral surface of the image bearing drum 2 via an adhesive. When the vibration damping member 4 is made of a rigid body, the same as described above, The damping member 4 can be inserted into the image bearing drum 2 and the damping member 4 can be fixed to the inner peripheral surface of the image bearing drum 2.
[0039]
When disassembling the image bearing drum 2 and the damping member 4 assembled thereto, first, the first flange 3 shown in FIG. 2 is removed from the image bearing drum 2. When the flange 3 is bonded to the image bearing drum 2, a force is applied to the flange 3 to break the adhesive, and the flange 3 is separated from the image bearing drum 2. Next, as shown in FIG. 6, the urging member 13 is inserted into the image bearing drum 2 from the opening 11, and the urging member 13 is inserted from the open end of the vibration damping member 4 into the cylindrical portion 17. Inserted, the tip 13A of the urging member 13 is brought into contact with the end wall 10, and the urging member 13 is pushed in the direction of arrow B. As a result, the damping member 4 moves in the axial direction of the image bearing drum 2, that is, in the direction of arrow B. Even when the damping member 4 is bonded to the inner peripheral surface of the image bearing drum 2, by pressing the damping member 4 in the direction of arrow B, the adhesive is broken and the damping member 4 is moved to the arrow B. Can be moved in the direction.
[0040]
By pushing the urging member 13 in the direction of arrow B as described above, the end wall 10 of the vibration damping member 4 that is pressed and moved by the urging member 13 contacts the second flange 3A as shown in FIG. The flange 3 </ b> A is removed from the image bearing drum 2 because it is in contact and pressurized. Also in this case, when the flange 3A is bonded to the image bearing drum 2, the adhesive is broken by pressurizing the flange 3A. When the urging member 13 is further moved in the arrow B direction, the damping member 4 is finally detached from the image bearing drum 2 as shown in FIG. Next, the urging member 13 is extracted from the image carrying drum 2. In this way, the vibration damping member 4 and the flange 3A can be removed from the image bearing drum 2 simply by pressing the vibration damping member 4 with the urging member 13, and these elements can be easily and inexpensively disassembled. can do.
[0041]
The vibration damping member 4 and the flanges 3 and 3A disassembled as described above can be reused as they are by cleaning them. Further, since the vibration damping member 4 before disassembly is disposed in a space surrounded by the image bearing drum 2 and the flanges 3 and 3A, the vibration damping member 4 is not used for the toner or toner during the use of the image bearing drum 2. The vibration damping member 4 can be reused without being cleaned after being separated from the image bearing drum without being contaminated by dust or the like.
[0042]
As described above, the method for inserting and removing the damping member from the image bearing drum according to this example inserts the damping member 4 into the image bearing drum 2 from the opening 11 on one end side in the axial direction of the image bearing drum 2. The vibration member 4 is mounted inside the image bearing drum 2, and the vibration damping member 4 is separated from the opening 12 on the other axial end side of the image bearing drum 2. A drum unit 34 is inserted into the image carrier drum 2 through the image carrier drum 2 and an opening 11 on one end side in the axial direction of the image carrier drum 2 and is mounted inside the image carrier drum 2. The vibration damping member 4 is separated from the image bearing drum 2 through the opening 12 on the other axial end side of the drum 2. With this configuration, the vibration damping member 4 can be attached to the image bearing drum 2 or removed from the image bearing drum 2 with a very simple operation, and the recyclability can be improved. It is only necessary to perform the same operation when the damping member 4 is attached and when it is detached.
[0043]
In addition, according to the method of inserting / removing the vibration damping member of this example, an external force is applied to the vibration damping member 4 by the biasing member 13 to move the vibration damping member 4 in the axial direction of the image carrying drum 2. The member 4 is mounted inside the image bearing drum 2, and similarly, an external force is applied to the damping member 4 by the biasing member 13 to move the damping member 4 in the axial direction within the image bearing drum 2. The vibration damping member 4 is configured to be detached from the image bearing drum. The damping member 4 is applied with an external force by the urging member 13 and moves in the image bearing drum 2 in the axial direction thereof, and is attached to the inside of the image bearing drum 2, and an external force is applied by the urging member 13 to apply the image. It is configured to move in the axial direction within the carrying drum and detach from the image carrying drum 2. According to this configuration, by operating the biasing member 13, the vibration damping member 4 can be inserted and removed from the image bearing drum 2 very easily.
[0044]
Further, when the damping member 4 is inserted into and removed from the image bearing drum 2, the damping member 4 moves in the axial direction within the image bearing drum 2, and this direction is simply referred to as a moving direction. Then, the end wall 10 of the damping member 4 is integrally provided on the front end side in the moving direction of the tubular portion 17 of the damping member 4, and the biasing member 13 is brought into contact with and engaged with the end wall 10. The damping member is pressurized by the biasing member 13. Thus, the end wall 10 of the damping member 4 constitutes an engaging portion with which the biasing member 13 is engaged, and hereinafter, the engaging portion made of the end wall 10 is denoted by reference numeral 1. To do.
[0045]
As described above, the vibration damping member 4 of this example is an engagement in which the biasing member 13 is engaged with the front end side in the movement direction when the vibration damping member 4 moves in the axial direction within the image bearing drum 2. And a biasing member 13 configured to apply an external force to the engaging portion 1 in the moving direction of the damping member 4 to move the damping member 4 in the axial direction of the image bearing drum 2. ing. The damping member 4 is configured to move in the image carrying drum 2 when an external force is applied to the end wall 10 of the damping member 4 by the urging member 13 when the damping member 4 is inserted and removed. A chamfered portion is formed at the edge of the end wall 10 of the damping member 4 on the inner peripheral surface side of the image bearing drum.
[0046]
According to the above configuration, the biasing member 13 can apply an external force to the engaging portion 1 in the axial direction of the image bearing drum 2 to reduce the outer diameter of at least a part of the vibration damping member 4. The member 4 can be smoothly moved in the image bearing drum 2. That is, in the illustrated example, the damping member 4 is made of an elastic body, and the outer diameter of the damping member 4 before being inserted into the image bearing drum 2 is set slightly larger than the inner diameter of the image bearing drum 2. Therefore, as shown in FIG. 5, when the damping member 4 is slightly pushed in the direction of arrow B by the urging member 13, the gap between the inner peripheral surface of the image bearing drum 2 and the outer peripheral surface 14 of the damping member 4 is increased. Due to the frictional force acting on the vibration damping member 4, the damping member 4 tries to stop once. However, when the engaging portion 1 is further pressed by the urging member 13, the vibration damping member 4 made of an elastic body tends to extend in the axial direction, and the vibration damping member 4 is moved as shown by an arrow C in FIG. Elastically deforms in the direction of diameter reduction. For this reason, the damping member 4 can be moved smoothly. This is the same when the vibration damping member 4 is pushed out of the image bearing drum 2.
[0047]
Assuming that the urging member 13 is configured to press the rear end side in the moving direction of the vibration damping member 4 made of an elastic body, a frictional force acting between the vibration damping member 4 and the inner wall surface of the image bearing drum is generated. By being added to the damping member 4, the damping member 4 swells in the radial direction, making it difficult to move it smoothly. However, by positioning the engaging portion 1 on the front end side in the moving direction of the damping member 4 Such a problem can be prevented.
[0048]
By the way, in the example described above, the damping member 4 is pushed in the axial direction of the image bearing drum 2 by the biasing member 13, and the damping member 4 is mounted inside the image bearing drum 2. The vibration damping member 4 is pushed out in the axial direction so that the vibration damping member 4 is detached from the image bearing drum 2. By pressing the engaging portion 1 of the damping member 4 from one end side to the other end side of the image bearing drum 2 by the urging member 13, the damping member 4 is moved in the image bearing drum. It is configured as follows.
[0049]
On the other hand, the vibration member is moved in the image carrying drum by pulling the engaging portion of the vibration damping member from one end side to the other end side of the image carrying drum by the urging member. You can also FIG. 8 is a cross-sectional view showing an example, and FIG. 8 shows a state in which the damping member 4 is pulled out from the image carrying drum 2. The end wall 10 of the vibration damping member 4, that is, the engagement portion 1 has an engagement hole 35. The hook portion 113A at the tip of the urging member 113 inserted into the image bearing drum 2 through the center hole 36 of the flange 3A is engaged with the engagement hole 35 of the engagement portion 1, and the urging member 113 is moved to the arrow B. By pulling in the direction, the damping member 4 can be detached from the inside of the image bearing drum 2. Also in this case, the flange 3 </ b> A can be pressurized by the damping member 4, and the flange 3 </ b> A can be detached from the image bearing drum 2. When the damping member 4 is inserted into the image bearing drum 2, the hook portion 113 </ b> A of the biasing member 113 is engaged with the damping member 4 with the flange 3 removed from the image bearing drum 2. The vibration damping member 4 may be pulled in the direction of arrow B by engaging with the joint hole 35.
[0050]
Other configurations of the drum unit 34 shown in FIG. 8 can be configured in the same manner as the drum unit described above. Also in the case of the drum unit shown in FIG. 8, the biasing member 113 applies an external force to the engaging portion 1 in the axial direction of the image bearing drum 2 to reduce the outer diameter of at least a part of the damping member 4. The vibration member 4 can be smoothly moved in the image bearing drum 2.
[0051]
In the example described above, the dedicated members 13 and 113 are used as the urging members for moving the vibration damping member 4 in the image carrying drum 2, but these urging members are arranged in the image carrying drum. A support shaft that supports the image bearing drum can also be used. FIG. 9 is a cross-sectional view showing an example thereof. In the drum unit 34 shown here, a support shaft 37 passes through the image bearing drum 2, and the support shaft 37 is press-fitted into the flanges 3 and 3 </ b> A. Further, the damping member 4 shown in FIG. 9 also has a cylindrical portion 17 having an outer peripheral surface fixed to the inner peripheral surface of the image bearing drum 2, similarly to the damping member 4 of the example described above. , And the end wall 10 integrally provided on the front end side in the moving direction of the cylindrical portion 17, and the end wall 10 constitutes the engaging portion 1 described above. Further, the engaging portion 1 composed of the end wall 10 of the vibration damping member 4 disposed inside the image bearing drum 2 has a diameter larger than the diameter of the support shaft 37 that supports the image bearing drum 2 and the support member. A hole 38 through which the shaft 37 passes is formed.
[0052]
The support shaft 37 is rotatably supported by the case 19 of the process cartridge 18 shown in FIG. 1, and the support shaft 37 constitutes an element of the process cartridge. A large-diameter portion 39 is provided in the middle portion in the longitudinal direction of the support shaft 37, and the large-diameter portion 39 can be brought into contact engagement with the engaging portion 1 of the vibration damping member 4.
[0053]
In order to assemble the damping member 4 in the image bearing drum 2, for example, the damping member 4 is disposed on the left side of the image bearing drum 2 in FIG. 9, and the support shaft 37 to which the flanges 3 and 3A are not attached is image bearing. The support shaft 37 is inserted into the hole 38 of the vibration damping member 4 while being inserted into the inside of the opening of the left end portion of the drum 2, and the engagement portion 1 of the vibration suppression member 4 is subsequently continued by the large diameter portion 39 of the support shaft 37. The support shaft 37 is inserted into the image bearing drum 2 together with the damping member 4 while pressing the damping member 4 in the direction of arrow B in FIG. Next, the flanges 3 and 3A are fitted to the respective end portions of the support shaft 37, and the flanges 3 and 3A are fitted into the openings of the respective end portions of the image carrying drum 2 to thereby hold the vibration damping member 4 in the image carrying manner. It can be mounted in the drum 2.
[0054]
When the vibration damping member 4 is removed from the image bearing drum 2, for example, the first flange 3 is first extracted from the support shaft 37, and then the support shaft 37 is moved in the direction indicated by the arrow B in FIG. The drum 2 is moved in the axial direction. Then, the large-diameter portion 39 of the support shaft 37 comes into contact with the engaging portion 1 of the vibration damping member 4 and presses it in the arrow B direction. For this reason, the damping member 4 moves together with the support shaft 37 in the axial direction of the image bearing drum, that is, in the arrow B direction. When the damping member 4 is bonded to the inner peripheral surface of the image bearing drum 2, the adhesive is broken by pressurizing the damping member 4 in the direction of the arrow B, and the damping member 4 is moved to the arrow B. Move in the direction. At this time, the support shaft 37 slides with respect to the second flange 3A. If the support shaft 37 is further moved in the direction of the arrow B, as shown in FIG. 10, the damping member 4 that moves together with the support shaft 37 pressurizes the second flange 3A, so that the flange 3A becomes the image bearing drum 2. Removed from. When the support shaft 37 is further moved in the arrow B direction, the vibration damping member 4 is finally detached from the image carrying drum 2. When the flange 3A is fitted to the image bearing drum 2 with a clearance fit, the flange 3A can be detached from the image bearing drum 2 before the damping member 4 contacts the flange 3A.
[0055]
As described above, the large diameter provided on the support shaft 37 in a state where the support shaft 37 is inserted into the hole 38 formed in the end wall 10 of the vibration control member 4 when the vibration control member 4 is inserted and removed. The end wall 10 of the damping member 4 is pressed by the portion 39 and elastically deformed in a direction to reduce the diameter of at least a part of the damping member 4, and the damping member 4 is moved in the axial direction of the image bearing drum 2. In the state where the damping member 4 and the support shaft 37 are arranged in the image bearing drum 2, the image is passed through the flanges 3 and 3A fitted to the openings at the respective axial ends of the image bearing drum 2. The support drum 2 is supported by the support shaft 37.
[0056]
The support shaft 37 is supported on the image forming apparatus main body, the support shaft 37 is left on the image forming apparatus main body side, the drum unit 34 is extracted from the support shaft 37, and the drum unit 34 is fitted to the support shaft 37. In this case, after the drum unit 34 is removed from the image forming apparatus main body, the damping member 4 is moved by the dedicated urging member 13 as shown in FIGS. If the damping member 4 is mounted inside the image bearing drum 2 by taking it out from the inside of the image bearing drum 2 or by a dedicated biasing member 13, the damping member 4 can be easily attached to the image bearing drum 2. Can be inserted and removed.
[0057]
Other configurations of the drum unit 34 shown in FIGS. 9 and 10 are the same as those shown in FIGS. 1 to 7.
[0058]
In addition, as shown in FIG. 11, the damping member 4 can be configured by a compression coil spring 40. The compression coil spring 40 is also pressed against the inner peripheral surface of the image bearing drum 2 by its elasticity, or is fixed to the inner peripheral surface of the image bearing drum 2 by an adhesive.
[0059]
When the damping member 4 comprising the compression coil spring 40 is inserted into the image bearing drum 2, the first flange 3 is removed from the image bearing drum 2, and the engaging portion 1 </ b> A on one end side of the spring 40 is engaged with the engaging portion 1 </ b> A. By engaging the hook portion 113 </ b> A of the urging member 113 and pulling the urging member 113 in the direction of arrow B, the vibration damping member 4 is moved from the opening 11 at one end in the axial direction of the image bearing drum 2 to the image bearing drum 2. Can be inserted in.
[0060]
Also, when the damping member 4 composed of the compression coil spring 40 is removed from the image bearing drum 2, the spring 40 is pulled in the direction of arrow B by the urging member 113 as described above. Thereby, the damping member 4 formed of the compression coil spring 40 can be detached from the image carrying drum 2 from the opening 12 on the other axial end side of the image carrying drum 2. Also in this case, the second flange 3A can be pressurized by the coil spring 40, and the flange 3A can be detached from the image bearing drum 2. The other configuration can be the same as the above-described example. At least a part of the compression coil spring 40 is applied by applying an external force to the engaging portion 1A in the axial direction of the image bearing drum 2 by the biasing member 113. There is no change in that the outer diameter of the spring 40 can be reduced and the spring 40 can be easily moved in the image bearing drum 2.
[0061]
As in each of the above-described examples, at least the vibration damping member portion that contacts the inner wall surface of the image bearing drum 2 is formed of an elastic body, and the vibration damping member 4 is caused by the elasticity of the vibration damping member 4 itself, that is, its restoring force. The vibration-damping member 4 is held inside the image-carrying drum 2 by being pressed against the inner wall surface of the image-carrying drum 2, so that the vibration-damping member 4 can be connected to the image-carrying drum 2 without using an adhesive. The vibration damping member 4 can be easily moved in the axial direction within the image bearing drum 2.
[0062]
In the illustrated example, when the damping member 4 is moved in the image bearing drum so as to be detached from the image bearing drum 2, the opening 12 on the other end side in the axial direction of the image bearing drum 2 is formed. Since the attached flange 3A is pressed by the vibration damping member 4 and the flange 3A is detached from the image bearing drum 2, the flange 3A can also be image bearing simply by pushing out the vibration damping member 4. The drum 2 can be detached from the drum 2 and the workability can be improved.
[0063]
At this time, if the flange 3A is press-fitted or held to the image carrier drum 2 by press-fitting or clearance fitting without using an adhesive, the flange 3A is removed along with the operation of removing the damping member 4 from the image carrier drum 2. Can be removed from the image bearing drum 2 with a small force, and the problem of scratching the flange 3A can also be prevented.
[0064]
As shown in FIG. 12, the second flange 3A has a cylindrical first flange member 15 fitted into the opening 12 on the other axial end side of the image bearing drum 2, and the first flange member. Alternatively, the second flange member 16 may be configured to be fitted to the first flange member 16. In this example, the gear 5 is formed on the first flange member 15. FIG. 13 is an exploded perspective view of the first flange member 15 and the second flange member 16.
[0065]
In order to attach the flange 3A to the image bearing drum 2, as shown in FIG. 14, the first flange member 15 is first fitted into the opening 12 at the end of the image bearing drum 2, and then the second flange member 16 is engaged. Is fitted to the first flange member 15. At this time, the outer diameter of the second flange member 16 before being fitted to the first flange member 15 is D1, and the thickness of the portion of the first flange member 15 inserted into the image bearing drum 2 is the same. Where T is T and the inner diameter of the image bearing drum 2 is D2, the diameters and thicknesses are set so that D1 + 2T> D2. As a result, when the second flange member 16 is fitted to the first flange member 15 as shown in FIG. 12, the portion of the first flange member 15 inserted into the image bearing drum 2 becomes the image bearing drum. The entire flange 3 </ b> A is fixed to the image bearing drum 2 by being strongly pressed against the inner peripheral surface 2. In this way, the second flange member 16 is fitted to the first flange member 15 so that the first flange member 15 is brought into pressure contact with the inner peripheral surface of the image bearing drum 2, and the flange 3 A is moved to the image bearing drum 2. It is fixed against. At this time, if a plurality of slits 42 are formed in the first flange member 15 as shown in FIG. 13, the second flange member 16 can easily press the first flange member 15 against the inner peripheral surface of the image bearing drum 2. Become. As the first flange 3 (FIG. 2), the types of flanges shown in FIGS. 12 to 14 can be used.
[0066]
When the second flange 3A is configured as described above, the diameter of the front end portion of the vibration damping member 4 on the side facing the flange 3A is reduced as shown in FIG. When the damping member 4 is moved in the direction of the arrow B in the image bearing drum 2 by the urging member 13 so as to be separated, the front end surface 41 of the front end portion of the damping member 4 is only on the second flange member 16. It is preferable to be configured to abut. The damping member 4 moves in the axial direction of the image bearing drum 2, and the front end surface 41 of the damping member 4 is the second flange member 16 of the first flange member 15 and the second flange member 16. The second flange member 16 is pressed against the first flange member 16 only.
[0067]
According to the configuration described above, when the second flange member 16 is pressed by the vibration damping member 4, the fitting between the second flange member 16 and the first flange member 15 is released with a small force. These flange members 15 and 16 can be easily detached from the image carrying drum 2 without applying a large load. For this reason, the malfunction that the 1st and 2nd flange members 15 and 16 are damaged can be prevented, and it becomes possible to reuse these flange members 15 and 16 as they are. This configuration can also be applied to the case where the urging member is composed of the support shaft 37 or configured as shown in FIGS.
[0068]
In addition, as shown in FIG. 12, at least a part 10A of the end wall 10 of the vibration damping member 4 that presses the second flange member 16 may be formed of a rigid body such as metal. According to this configuration, the force by the urging member 13 can be directly transmitted to the second flange member 16, and the second flange member 16 can be efficiently removed from the first flange member 15.
[0069]
Other configurations of the exemplary embodiments shown in FIGS. 12 to 14 can be configured in the same manner as the exemplary embodiments described above.
[0070]
In the image forming apparatus shown in FIG. 1, the drum unit 34 and an image forming device such as a charging roller 20, a developing device 22 and a cleaning device 27 for forming an image on the image bearing drum 2 are assembled together. Since the process cartridge 18 is configured, when the process cartridge 18 reaches the end of its life, it is only necessary to replace it, and maintenance of the image forming apparatus can be easily performed.
[0071]
In general, such process cartridges are reduced in size and weight so that the handleability thereof is improved. Therefore, since the small component is used as the component, the life of the process cartridge is generally short. The image forming apparatus shown in FIG. 1 is configured to replenish toner in the toner container 33. However, the toner is not replenished in this way, and the process cartridge is replaced when the toner in the developing device is used up. In such a configuration, the lifetime is further shortened. Thus, the short life of the process cartridge means that the number of production is increased and the number of process cartridges on the market is increased. Therefore, it is an important problem to make it easy to disassemble the image bearing drum 2, the damping member 4, and the flanges 3 and 3A and to improve the recyclability thereof. By constructing the image bearing drum 2, the damping member 4, and the flanges 3 and 3A so that they can be assembled or disassembled as described above, these can be easily recycled and the above requirements can be satisfied with certainty. it can.
[0072]
Incidentally, in the image forming apparatus shown in FIG. 1, in order to save energy, a low melting point toner is used, and the toner image transferred to the recording medium P can be fixed at a relatively low temperature. Yes. Specifically, the toner used in the developing device 22 so that the toner image transferred to the recording medium P can be fixed in the fixing device at a relatively low temperature of the fixing roller, for example, about 145 ° C. A low melting point toner is used. A toner image is formed on the image bearing drum with toner having an outflow start temperature measured by a flow tester method of 102 ° C. or lower, preferably 99 ° C. to 102 ° C. Shimadzu flow tester CFT500 type manufactured by Shimadzu Corporation is used for measurement of the outflow start temperature by the flow tester method. This flow tester heats and melts a sample contained in a cylinder from the periphery of the cylinder, applies pressure with a constant load from the top of the cylinder with a piston, and places the molten sample in a hole in a die disposed at the bottom of the cylinder. The temperature at which the sample flows out from the die hole is the outflow start temperature. The load applied to the piston is 10 kg / cm ² A toner image is formed on the image bearing drum using toner having a temperature rise rate of 3.0 ° C./min, a die diameter of 0.5 mm, and a die length of 10.0 mm and an outflow start temperature of 102 ° C. or less. It forms. The flow tester method is described in JP-A Nos. 2001-147551 and 2001-75106.
[0073]
When the low melting point toner as described above is used, abnormal noise is more likely to be generated from the image bearing drum than when a high melting point toner is used. The reason why abnormal noise increases when low-melting toner is used is not necessarily clear, but additives such as wax in the toner are likely to adhere to the surface of the image bearing drum, and the amount of adhesion becomes uneven depending on the image pattern. For this reason, it is considered that the member that contacts the surface of the image carrying drum, for example, the cleaning blade becomes non-uniform in movement, and the image carrying drum emits severe noise due to the vibration.
[0074]
Therefore, it is desirable to use the damping member 4 made of a material having a loss tangent tan δ of 0.5 or more as the damping member described above. The tangent of the stress and strain phase angle: δ (loss angle) in a certain material is the loss tangent (tan δ), and the larger the value of this loss tangent tan δ, the greater the damping effect. By paying attention to the characteristics of such a material and providing the damping member 4 made of a substance having a loss tangent tan δ value of 0.5 or more in the image bearing drum 2, the rotating image bearing drum 2 is effectively controlled. Even if the low-melting-point toner as described above is used, it is possible to keep the abnormal noise generated from the image carrying drum 2 that rotates during image formation to an extremely low level. As the substance having a loss tangent tan δ of 0.5 or more, for example, a rubber material such as butyl rubber or nitrile rubber can be used.
[0075]
Further, when a toner containing a higher fatty acid metal salt such as zinc stearate is used as the toner used in the image forming apparatus, a part of the toner adheres to the surface of the image carrying drum 2 and the friction coefficient with the cleaning blade 30. Therefore, the sliding of the edge portion of the cleaning blade 30 becomes good, the vibration of the cleaning blade 30 can be suppressed, and the effect of preventing abnormal noise generation can be further enhanced.
[0076]
The present invention can be applied to various forms of image forming apparatuses other than the form shown in FIG. 1, and can also be applied to, for example, the image forming apparatus shown in FIG. In the image forming apparatus shown in FIG. 15, the image carrying drum 2 rotating in the direction of the arrow is charged by the charging roller 20, and the charged surface is irradiated with a laser beam L emitted from an exposure device (not shown) to carry the image. A first electrostatic latent image is formed on the drum 2. Next, the electrostatic latent image is visualized as a yellow toner image by the yellow developing device 22Y of the developing device 22, and the toner image is transferred to the intermediate transfer belt 50 rotating in the direction of arrow E. The surface of the image bearing drum after the transfer of the yellow toner image is cleaned by the cleaning device 27.
[0077]
In exactly the same manner as described above, a second electrostatic latent image is formed on the image bearing drum 2, and the latent image is visualized as a magenta toner image by the magenta developing device 22M of the developing device 22. The toner image is transferred onto the intermediate transfer belt 50 so as to overlap the previously transferred yellow toner image. In exactly the same manner, a cyan toner image and a black toner image are sequentially formed on the image bearing drum 2 by the cyan developing device 22C and the black developing device 22BK of the developing device 22, respectively. It is transferred on top of it.
[0078]
Thus, the superimposed toner image transferred onto the intermediate transfer belt 50 is transferred onto the recording medium P fed from the paper feeding device 51, and when the recording medium passes through the fixing device 52, the toner image is transferred. Is fixed on the recording medium.
[0079]
The image bearing drum 2 of the above-described image forming apparatus is also provided with a vibration damping member 4, and the vibration damping member 4 is inserted into the image bearing drum 2 as described above, and then from the image bearing drum 2. Will be withdrawn. In the case of the image forming apparatus shown in FIG. 15, the image carrier drum 2, at least one image forming device for forming a toner image on the image carrier drum, and the intermediate transfer member 50 are assembled together. The process cartridge 18 can also be configured.
[0080]
As described above, the embodiment in which the image bearing drum is composed of the photosensitive drum has been described. However, each of the above-described configurations can be applied even when the image bearing drum is composed of the intermediate transfer drum to which the toner image is transferred from the photoreceptor. .
[0081]
【The invention's effect】
According to the present invention, the image bearing drum and the vibration damping member can be easily disassembled, and the recyclability thereof can be improved.
[Brief description of the drawings]
FIG. 1 is a schematic cross-sectional view showing a part of an image forming apparatus.
FIG. 2 is a longitudinal sectional view of a drum unit.
FIG. 3 is an exploded perspective view of an image bearing drum and a flange.
FIG. 4 is a cross-sectional view showing a state when a damping member is inserted into the image bearing drum.
FIG. 5 is a cross-sectional view showing a state when a vibration damping member is pushed into an image bearing drum.
FIG. 6 is a cross-sectional view showing a state when the damping member comes into contact with the flange.
FIG. 7 is a cross-sectional view showing a state where the flange is removed from the image bearing drum and the vibration damping member is further pushed out.
FIG. 8 is a cross-sectional view showing an example in which the damping member is pulled with respect to the image bearing drum by pulling the damping member with an urging member.
FIG. 9 is a longitudinal sectional view showing another example of the drum unit.
10 is a cross-sectional view showing a state when the support shaft and the damping member are moved from the position shown in FIG.
FIG. 11 is a cross-sectional view of a drum unit in which a damping member is formed of a compression coil spring.
FIG. 12 is a cross-sectional view showing an example using a flange having first and second flange members.
FIG. 13 is a perspective view of first and second flange members.
FIG. 14 shows a state in which the first and second flange members are assembled to the image bearing drum.
It is sectional drawing.
FIG. 15 is a schematic cross-sectional view illustrating another example of the image forming apparatus.
[Explanation of symbols]
2 Image bearing drum
3,3A flange
4 Damping members
10 End wall
11,12 opening
14 Outer surface
15 First flange member
16 Second flange member
17 Cylindrical part
18 Process cartridge
34 drum units
37 spindle
38 holes
41 Front end face

Claims (10)

An image bearing drum and an opening on one end side in the axial direction of the image bearing drum are inserted into the image bearing drum and mounted inside the image bearing drum, and an opening on the other end side in the axial direction of the image bearing drum A damping member that is detached from the image bearing drum from the image bearing drum, and a flange that is fitted into an opening at each end in the axial direction of the image bearing drum. The damping member is an inner peripheral surface of the image bearing drum. A cylindrical portion having an outer peripheral surface that is fixed with respect to the inner wall of the cylindrical portion, and an end wall that is integrally provided on the front end side in the moving direction of the damping member of the cylindrical portion. A chamfered portion is formed on the edge on the surface side, and the damping member is moved in the image bearing drum by applying an external force to the end wall of the damping member by the urging member when the damping member is inserted and removed. And a supporting shaft for supporting the image bearing drum is used as the biasing member. A large-diameter portion is provided in the longitudinal intermediate portion of the support shaft, and a hole having a diameter larger than that of the support shaft is formed in the end wall of the vibration control member. In a state where the support shaft is inserted into the hole formed in the end wall of the vibration member, the end wall of the vibration suppression member is pressurized by the large diameter portion provided in the support shaft, and at least the vibration suppression member The image bearing drum is moved in a state where the vibration damping member and the support shaft are disposed in the image bearing drum while the vibration damping member is moved in the axial direction of the image bearing drum while being elastically deformed in a direction to reduce the diameter. A drum unit in which an image bearing drum is supported by the support shaft through the flanges fitted into openings at respective end portions in the axial direction of the drum. 2. The drum unit according to claim 1, wherein the damping member is held inside the image bearing drum by being pressed against an inner peripheral surface of the image bearing drum by elasticity of the damping member. The drum unit according to claim 1, wherein the damping member is fixed to an inner peripheral surface of the image bearing drum with an adhesive. When the damping member is moved in the image bearing drum so as to be detached from the image bearing drum, a flange attached to the opening on the other axial end side of the image bearing drum is pressed by the damping member. 4. The drum unit according to claim 1, wherein the flange is detached from the image bearing drum. The drum unit according to claim 1, wherein the flange is fitted and held on the image bearing drum by press fitting or clearance fitting. The flange includes a first flange member that fits in an opening on the other axial end side of the image bearing drum, and a first flange member that fits the first flange member to the inner periphery of the image bearing drum. A second flange member pressed against the surface, and when the vibration damping member is moved within the image bearing drum to disengage the vibration damping member from the image bearing drum, the front end surface of the vibration damping member is 6. The drum unit according to claim 1, wherein only the second flange member of the first flange member and the second flange member is brought into contact with and presses the second flange member. A drum unit according to any one of claims 1 to 6 and at least one image forming device for forming a toner image on an image bearing drum of the drum unit, and is detachably attached to an image forming apparatus main body. A process cartridge. An image forming apparatus comprising the process cartridge according to claim 7. An image forming apparatus comprising the drum unit according to claim 1. 10. A damping member made of a material having a loss tangent tan δ of 0.5 or more is formed using a toner having an outflow start temperature measured by a flow tester method of 102 ° C. or less to form an image bearing drum. The image forming apparatus described in 1.

Images