JP2023154439A - Image forming device - Google Patents

Abstract

To provide an image forming device which suppresses deterioration in replacement workability of roller members while suppressing an increase in the number of parts.SOLUTION: A transfer member is configured thicker than pivotally supported support parts, provided on a shaft part to rotate integrally with the shaft part, and is provided with gripping parts to be held by a user when replacing the transfer member.SELECTED DRAWING: Figure 3

Description

The present invention relates to an image forming apparatus that forms a toner image on a recording material.

2. Description of the Related Art Conventionally, as a replacement roller member for an image forming apparatus, a transfer roller that is removably attached to the main body of the image forming apparatus is known. This transfer roller is placed in a position facing the image carrier when installed in the main body of the image forming apparatus, and is arranged so that it comes into contact with the back surface of the sheet when the sheet passes between the image carrier and the transfer roller. It is provided. The transfer roller is used to convey the sheet along the moving direction of the surface of the image carrier while bringing the surface of the sheet into contact with the image carrier. The transfer roller replacement work is generally performed by a professional service person who is accustomed to the replacement work, and is rarely performed by a general user who is inexperienced with the replacement work. Therefore, no emphasis was placed on the ease of handling the transfer roller during replacement work. However, in recent years in image forming apparatuses, there are increasing opportunities for general users to replace the transfer rollers of the image forming apparatuses in order to reduce the cost burden. Therefore, it is desired to improve the workability of replacing the transfer roller so that even general users can appropriately and easily replace the transfer roller.

In Patent Document 1, a handle member is attached to both end shaft portions extending outward from both ends of the transfer roller in the direction of the roller rotation axis. Further, a part of the handle member is used as a guide member that regulates the direction of conveyance of the sheet by coming into contact with the sheet being conveyed when the image forming apparatus is attached to the main body. With this configuration, the operator who replaces the transfer roller can handle the handle member by holding the handle member in his/her hand, so that the replacement work can be easily performed.

Japanese Patent Application Publication No. 2011-107733

However, the handle member described in Patent Document 1 also serves as a guide member that regulates the conveyance direction of the sheet. For this reason, the unit to be replaced is larger and more complex than the case of a single roller member. Further, when the handle member is attached to the device, the position is fixed, so that the handle member slides on the roller member. For this reason, new parts such as bearings for reducing frictional resistance are required between the handle member and the roller member, resulting in an increase in the number of parts.

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide an image forming apparatus that has a simple configuration and can suppress deterioration in workability for replacing roller members.

Therefore, the present invention provides an image forming section that forms a toner image, and an intermediate transfer belt to which the toner image formed by the image forming section is transferred. an image forming apparatus comprising: a transfer member that transfers a toner image from the intermediate transfer belt to a recording material; and a bearing that rotatably supports the transfer member; Image formation comprising: a roller section made of an elastic body that forms a transfer section that contacts the outer peripheral surface of a belt to transfer a toner image; and a shaft section that rotates together with the roller section and supports the roller section. In the apparatus, the shaft portion includes a contact portion that abuts and is supported by the bearing portion, and a handle portion for gripping when the transfer member is replaced, and the handle portion is configured to hold the transfer member. is arranged outside the abutting part in the direction of the rotation axis of the transfer member, and is configured to be thicker than the abutting part, and when the transfer member is attached to the bearing part, the transfer member is arranged on the apparatus main body side and It is characterized in that it is provided so as to rotate integrally with the shaft portion at a position where it does not come into contact with the shaft portion.

According to the present invention, it is possible to provide an image forming apparatus that has a simple configuration and can suppress deterioration in workability for replacing roller members.

A simplified cross-sectional view of the image forming apparatus of this embodiment (when the cover is closed) A simplified cross-sectional view of the image forming apparatus of this embodiment (when the cover is open) Perspective view of secondary transfer outer roller Front view of secondary transfer outer roller Perspective view of secondary transfer unit Simplified sectional view of the rotational axis direction when installing the secondary transfer outer roller

Embodiments of the present invention will be described below based on the accompanying drawings. It should be noted that the dimensions, materials, shapes, and relative positions of the components are not intended to limit the scope of the present invention, unless specifically stated otherwise.

(Overall configuration of image forming apparatus)
The overall configuration of an image forming apparatus according to an embodiment of the present invention will be described. FIG. 1 is a schematic diagram of a color image forming apparatus using an electrophotographic method. This image forming apparatus 100 is an intermediate transfer tandem type image forming apparatus in which four color image forming sections of yellow (Y), magenta (M), cyan (C), and black (Bk) are arranged side by side on an intermediate transfer belt 2. It is. Note that in FIG. 1, the direction perpendicular to the paper surface is the front-rear direction of the apparatus.

The image forming apparatus 100 includes process cartridges Pa, Pb, Pc, and Pd for forming toner images. These process cartridges use toners of different colors: yellow, magenta, cyan, and black, but otherwise have the same configuration. In FIG. 1, photoreceptors 6a, 6b, 6c, and 6d are driven to rotate clockwise. The surface is exposed and scanned by exposure devices 7a, 7b, 7c, and 7d driven based on image information signals, and an electrostatic latent image is formed. This electrostatic latent image is developed as a toner image by process cartridges Pa, Pb, Pc, and Pd. Thereafter, a predetermined pressing force and primary transfer bias are applied by the primary transfer devices T1a, T1b, T1c, and T1d, and a toner image is formed on the intermediate transfer belt 2.

Primary transfer bias rollers 5a, 5b, 5c, and 5d and a transfer cleaning device 4 are in contact with the intermediate transfer belt 2. Further, the intermediate transfer belt 2 is an endless belt, stretched by a plurality of stretching rollers, and conveyed counterclockwise in the figure. The plurality of tension rows include a secondary transfer inner roller 1 that also serves to transmit drive to the intermediate transfer belt 2, a tension roller 3, and a secondary transfer upstream roller 8. The primary transfer devices T1a, T1b, T1c, and T1d include primary transfer bias rollers 5a, 5b, 5c, and 5d. The primary transfer bias rollers 5a, 5b, 5c, and 5d sandwich the intermediate transfer belt 2 with the photoreceptors 6a, 6b, 6c, and 6d, thereby forming a primary transfer nip. The toner image primarily transferred onto the intermediate transfer belt 2 passes through the primary transfer nip on the downstream side in the rotational direction of the intermediate transfer belt 2 as the intermediate transfer belt 2 is driven to convey. The images are transferred so that they overlap. Then, four-color toner images are formed on the intermediate transfer belt 2, and transported to the secondary transfer section T2.

The recording sheets S (recording media or recording materials) stacked and stored in the recording sheet storage 11 are fed one by one by the feeding roller 12, and are corrected for skew by the registration rollers 13 and are transferred to the secondary sheet at an appropriate timing. It is sent to the transfer section T2. In the secondary transfer section T2, a nip is formed by the secondary transfer inner roller 1 and the secondary transfer outer roller 200 sandwiching the intermediate transfer belt 2 between them, and the four color toners formed on the intermediate transfer belt 2 are The image is secondarily transferred onto the recording sheet S.

The recording sheet S after the secondary transfer is conveyed to the fixing device 14, the toner image on the recording sheet S is fixed, and the recording sheet S is discharged outside the machine by a pair of discharge rollers 15, and is sequentially stacked on the stack section 16. Ru.

(Cover opening/closing operation)
In this embodiment, a cover 10 that can be opened and closed is provided on the right side of the image forming apparatus 100. This is to clear the jam of the recording sheet S that occurred in the conveyance path and to replace parts such as the secondary transfer outer roller 200. The cover 10 is provided with a cover rotation shaft 18, and is rotatably supported around a horizontal axis in the front-rear direction by engaging the image forming apparatus 100 with the cover rotation shaft 18. Here, FIG. 2 shows how the cover 10 is released. As shown in FIG. 2, the cover 10 is supported by the main body of the apparatus by a link mechanism (not shown), and is configured to stop at a predetermined position when opened.

Here, the secondary transfer unit 300 is included in the cover 10. When the cover 10 is closed as shown in FIG. 1, the secondary transfer unit 300 is sandwiched between the apparatus main body and the cover 10 and positioned at a predetermined position. At this time, the secondary transfer outer roller 200 is opposed to the secondary transfer inner roller 1 via the intermediate transfer belt 2 and is pressed against the intermediate transfer belt 2, and becomes operable. That is, the secondary transfer outer roller 200 comes into contact with the outer peripheral surface of the intermediate transfer belt 2 to form the secondary transfer portion T2.

When the cover 10 is opened as shown in FIG. 2, the secondary transfer outer roller 200 is separated from the intermediate transfer belt 2 (secondary transfer inner roller 1) and released, and the operator can move It can be accessed.

(Configuration of secondary transfer outer roller)
Next, the structure of the secondary transfer outer roller 200 as a transfer member, which is a replacement roller member and is a characteristic part of the present invention, will be described.

FIG. 3 is an external perspective view showing the secondary transfer outer roller 200. As shown in FIG. The secondary transfer outer roller 200 of this embodiment has a roller portion 201 made of an elastic body formed on the circumferential surface of a core metal. The secondary transfer outer roller 200 has a shaft portion 202 made of a metal member that supports the roller portion 201 . The shaft portion 202 is longer than the roller portion 201, supports the inner surface of the roller portion 202, and is configured to extend outward from both ends of the roller portion 201 in the direction of the roller rotation axis. Further, the shaft portion 202 is formed with two holding portions 203 as handle portions for an operator to hold during replacement. The secondary transfer outer roller 200 is rotatably supported by the secondary transfer unit 300 as described later.

FIG. 4 is a front view of the secondary transfer outer roller with the roller rotation axis direction being horizontal. The shaft portion 202 consists of a large diameter portion 202a with a large diameter that is flush with the inner diameter portion where the roller portion 201 is formed, and a small diameter portion 202b with a small diameter located outside of the large diameter portion 202a. Further, a part of the small diameter part 202b is a contact part 202b' that is rotatably abutted and supported (pivotally supported) by the main body (bearing part 302a), and this part has high sliding properties, for example, the surface texture is It is made with high precision, Ra approximately 0.8.

Further, the holding portion 203 is provided outside the contact portion 202b' in the direction of the roller rotation axis. The holding portion 203 has a substantially cylindrical shape that is substantially symmetrical with respect to the cross section of the roller rotation axis. Here, the holding part 203 may be formed integrally with the shaft part 202 or may be a separate body. If they are separate bodies, they are made of, for example, a resin member, and are lightly press-fitted from the outside into the ends of the two small diameter portions 202b and fixed therein.

Here, the dimensional relationship between the shaft portion 202 and the holding portion 203 is as follows: If the diameter of the holding portion 203 is D1, the width in the rotational axis direction is L1, the diameter of the contact portion 202b' is D2, and the width in the rotational axis direction is L2, D1> D2, L1>L2.

Since the outer dimensions of the holding parts 203 located at both ends of the secondary transfer outer roller 200 are large in this way, it becomes easier for the operator to grasp the secondary transfer outer roller 200 during replacement work. This improves the ease of handling during replacement work. In addition, the outer diameter of the holding portion 203 is configured to be smaller than the outer diameter of the roller portion 201 of the secondary transfer outer roller 200, so that it is possible to suppress the increase in size of the apparatus while suppressing a decrease in replacement workability. can. Further, the holding portion 203 is provided at a position where it does not come into contact with the apparatus main body side when the secondary transfer outer roller 200 is attached. Moreover, the holding part 203 is provided so as to rotate together with the shaft part 202. Therefore, when the secondary transfer outer roller 200 rotates, the holding portion 203 does not slide against other members and no sliding resistance occurs. Therefore, there is no need to provide a new component between the holding part 203 and the sliding resistance to reduce the sliding resistance.

Further, the holding section 203 is colored in a designated color representing the operator's operation section, so that the holding section can be identified at a glance. This prevents the operator from accidentally holding other parts during operation. That is, it can be expected to be effective in preventing problems such as deterioration in paper conveyance performance of the outer secondary transfer roller 200 and deterioration in print quality due to the adhesion of hand oil to the surface of the roller portion 201.

(Configuration of secondary transfer unit)
The configuration of the secondary transfer unit 300, which is a portion to which the secondary transfer outer roller 200 is attached, will be described. FIG. 5 is an external perspective view showing the secondary transfer unit 300.

The secondary transfer unit 300 of this embodiment includes a sheet guide section 301 that guides the sheet S conveyed from the upstream side of the conveyance path, and a roller engagement section 302 that rotationally supports the secondary transfer outer roller 200. . Further, the roller engaging portion 302 includes a bearing portion 302a and a roller suppressing portion 302b.

Here, the support structure for the secondary transfer outer roller 200 of the secondary transfer unit 300 will be explained. FIG. 6 is a sectional view in the direction of the roller rotation axis showing the positional relationship between the secondary transfer outer roller 200 and the roller engaging portion 302 when the cover 10 is opened. Here, as shown in FIGS. 5 and 6, the rotation axis direction of the roller is P, the roller insertion/removal direction is Q, and the direction perpendicular to the above P and Q is R.

First, with respect to the direction P, as shown in FIG. The positioning is done by fitting.

Furthermore, regarding the direction Q and the direction R, as shown in FIG. 6, the upper part of the roller suppressing part 302b is a narrow opening part 302c. Here, if the width of this opening is defined as X2, then the relationship of X2<D2 holds true. That is, in the direction Q and the direction R, the secondary transfer outer roller 200 is fixed to the roller restraining portion 302b by a snap fit.

(Replacing the secondary transfer outer roller)
The replacement work when replacing the outer secondary transfer roller 200 will be explained.

When replacing the secondary transfer outer roller 200, the operator first opens the cover 10 to expose the secondary transfer unit 300, as shown in FIG. At this time, the secondary transfer outer roller 200 is fixed to the secondary transfer unit 300 by a snap fit as described above. The operator grasps the holding part 203 and lifts it in the roller insertion/removal direction Q. At this time, since the holding part 203 is colored in a designated color representing the operating part, the operator can easily visually recognize which part to grip while working. As a result of the above, the roller small diameter portion 202b of the secondary transfer outer roller 200 comes off from the roller engaging portion 302 of the secondary transfer unit 300, and the secondary transfer roller 200 comes off from the secondary transfer unit 300. In this way, the work of removing the secondary transfer roller 200 from the apparatus main body is completed.

Next, a new replacement secondary transfer outer roller 200 is attached to the secondary transfer unit 300 in the reverse order of the removal operation described above. The operator grasps the holding portion 203 of the secondary transfer outer roller 200 for replacement. In this state, the small diameter portion 202b is pressed so as to fit into the roller receiving portion 302 of the secondary transfer unit 300, and the secondary transfer outer roller 200 is snap-fitted and fixed to the secondary transfer unit 300.

At this time, since the secondary transfer outer roller 200 has a substantially symmetrical shape with respect to the two directions Q and R perpendicular to the rotational axis direction P, the operator needs to consider the orientation when installing with respect to the above two directions. There is no.

Finally, the operator closes the cover 10 to complete the installation work of the replacement secondary transfer roller 100.

As described above, by adopting the configuration of this embodiment, the worker who replaces the secondary transfer outer roller can grasp the large-outline holding portion 203 at the end of the secondary transfer outer roller 200. Replacement work will be carried out. Further, the secondary transfer outer roller 200 has a substantially symmetrical shape with respect to two directions perpendicular to the roller rotation axis direction P. For this reason, there is no need to consider the direction of assembly with respect to the two directions mentioned above. As a result, the operator can easily grasp the secondary transfer roller, which improves handling, and improves the workability when fitting the roller into the roller engaging portion. Furthermore, the risk of incorrect assembly due to unclear mounting positions and orientations is reduced. That is, the operator can easily and appropriately replace the secondary transfer outer roller 200.

Note that in this embodiment, a case has been described in which the conveyance roller to be replaced is the secondary outer transfer roller 200, but it may be another conveyance roller, and the conveyance roller may be a driving roller or a driven roller. .

S sheet 100 Image forming device 200 Secondary transfer outer roller 201 Roller section 202 Shaft section 202a Large diameter section 202b Small diameter section 203 Holding section 300 Secondary transfer unit 301 Sheet guide section 302 Roller engaging section 302a Bearing section a
302b Roller holding part P Roller rotation axis direction Q Roller insertion/extraction direction R Direction perpendicular to direction P and direction Q

Claims (5)

an image forming section that forms a toner image;
an intermediate transfer belt to which the toner image formed by the image forming section is transferred;
a transfer member that is rotatably provided, contacts the outer peripheral surface of the intermediate transfer belt, and transfers the toner image from the intermediate transfer belt to a recording material;
a bearing portion rotatably supporting the transfer member;
The transfer member includes a roller portion made of an elastic body that forms a transfer portion that contacts the outer peripheral surface of the intermediate transfer belt and transfers the toner image, and a shaft that rotates together with the roller portion and supports the roller portion. An image forming apparatus comprising:
The shaft portion includes a contact portion that abuts and is supported by the bearing portion, and a handle portion for gripping the transfer member when the transfer member is replaced, and the handle portion is configured to rotate around the rotation axis of the transfer member. a position that is arranged outside the abutting part in the direction and configured to be thicker than the abutting part, and does not come into contact with the apparatus main body side when the transfer member is attached to the bearing part; An image forming apparatus characterized in that the image forming apparatus is provided to rotate integrally with the shaft portion. The image forming apparatus according to claim 1, wherein an outer diameter of the handle portion is larger than an outer diameter of the contact portion and smaller than an outer diameter of the roller portion. 3. The image forming apparatus according to claim 1, wherein the shaft portion is made of a metal member, and the handle portion is made of a resin member. 4. The image forming apparatus according to claim 3, wherein the handle part is colored in a designated color in order to identify the handle part when the transfer member is replaced. The image forming apparatus according to claim 1 or 2, wherein the length of the handle portion is longer than the length of the contact portion in the direction of the rotation axis.

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