JP2016145929A - Cleaning device and image forming apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a cleaning device that can clean a rotary member with an inexpensive configuration.SOLUTION: A torsion spring 28 as urging means is in contact at one end 28a with a rotation shaft 27a of a cleaning roller 27. The one end 28a of the torsion spring 28 applies an urging force in a direction of an arrow F1 to the rotation shaft 27a, and the cleaning roller 27 is urged in the direction of the arrow F1 and pressed against a pressure roller 23. The torsion spring 28 presses a bearing 31 against the cleaning roller 27 to apply a load to the rotation of the cleaning roller 27.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a cleaning device and an image forming apparatus in a copying machine, a printer, a facsimile, or a complex machine including the cleaning device.

  2. Description of the Related Art In an image forming apparatus in a copying machine, a printer, a facsimile machine, or a complex machine thereof, a cleaning device having a cleaning member for removing adhered substances such as toner and paper dust on the surface of a rotating member such as a fixing roller is provided.

  In such a cleaning apparatus, there is a configuration in which the cleaning member removes deposits on the surface of the cleaning member by contacting the rotating rotating member.

  In the cleaning device having such a configuration, one problem is to ensure sufficient cleaning performance of the cleaning member on the surface of the rotating member by generating a sufficient frictional force between the cleaning member and the rotating member. Become.

  For example, in Patent Document 1 (Japanese Patent Laid-Open No. 01-206382), as shown in FIG. 11, the rotating body 100, the cleaning rotating body 101 in contact with the rotating body 100, and the cleaning rotating body 101 are combined with the rotating body 100. A cleaning mechanism for a fixing device having an urging tool 102 that urges toward the side, a load applying member 103 that is a plate-like spring member, and a rotating rotating member 104 that is coaxial with the cleaning rotating member 101 is disclosed. ing.

  In the cleaning mechanism of the fixing device described above, the cleaning rotary body 101 abuts on the rotary body 100 by the biasing force of the biasing tool 102, and the cleaning rotary body 101 is driven to rotate by the rotary body 100, thereby Clean the surface. At this time, the pressing load from the load applying member 103 is applied to the cleaning rotating body 101 via the different diameter rotating body 104, and the load for rotating the cleaning rotating body 101 is increased. As a result, the frictional force between the cleaning rotary body 101 and the rotary body 100 is increased, and the cleaning rotary body 101 is rotated in a slipping manner with respect to the rotary body 100 so that the cleaning rotary body 101 is rotated. The effect of wiping off the toner on the surface 100 is obtained, and the toner can be removed appropriately.

  In the invention of Patent Document 1, as described above, by providing the load applying member 103 and the different-diameter rotating body 104 which are separate members, the frictional force between the rotating body 100 and the cleaning rotating body 101 is increased, thereby rotating the rotating body. 100 has an effect of removing the toner on the surface, and there is a problem that the cost of the entire apparatus is increased.

  Under such circumstances, an object of the present invention is to provide a cleaning device that can clean a rotating member with a cheaper configuration.

  In order to solve the above-described problems, the present invention provides a cleaning member that has a cleaning member that contacts and rotates with the rotating member, cleans the surface of the rotating member, and a holding member that holds the rotating shaft of the cleaning member. The apparatus is characterized in that the holding member is pressed against the cleaning member.

  In the cleaning device of the present invention, the holding member that holds the cleaning member also has a function of applying a load to the rotation of the cleaning member. As a result, the number of parts can be reduced, and the cost of the entire cleaning apparatus can be reduced.

1 is a schematic configuration diagram of an image forming apparatus. It is sectional drawing of the cleaning apparatus which concerns on 1st embodiment of this invention. It is a perspective view which shows the mode of the assembly | attachment of each member to a bearing. It is sectional drawing of the bearing periphery of the state which assembled | attached the torsion spring. It is a top view which shows the shape of the torsion spring before an assembly | attachment. It is the schematic which shows the direction of the force which a torsion spring receives. It is the schematic which shows the inclination of a bearing. It is sectional drawing of the cleaning apparatus which concerns on 2nd embodiment of this invention. It is a perspective view of the cleaning apparatus which concerns on 2nd embodiment of this invention. It is a perspective view of the cleaning apparatus which concerns on 2nd embodiment of this invention. It is a schematic block diagram of the conventional image forming apparatus.

  Hereinafter, embodiments according to the present invention will be described with reference to the drawings. In addition, in each figure, the same code | symbol is attached | subjected to the part which is the same or it corresponds, The duplication description is simplified or abbreviate | omitted suitably.

  In the center of the color image forming apparatus 1 shown in FIG. 1, an image forming unit 2 in which four process units 9Y, 9M, 9C, 9Bk are detachably provided is arranged. Each process unit 9Y, 9M, 9C, 9Bk contains developers of different colors of yellow (Y), magenta (M), cyan (C), and black (Bk) corresponding to the color separation components of the color image. The configuration is the same except that.

  Specifically, each process unit 9 includes a drum-like rotating body capable of carrying toner as a developer on its surface, and a photosensitive drum 10 as a rotating member, and the surface of the photosensitive drum 10 uniformly. A developing device 12 having a charging roller 11 for charging and a developing roller 13 for supplying toner to the surface of the photosensitive drum 10 is provided.

  The toner used for image formation can also use silica containing oil as an external additive. The effects of using the oil-containing silica as an external additive include extending the life of the process cartridge, improving cleaning properties, and improving transfer efficiency.

  An exposure unit 3 is disposed above the process unit 9. The exposure unit 3 is configured to emit laser light based on the image data.

  A transfer unit 4 is disposed immediately below the image forming unit 2. The transfer unit 4 is an endless intermediate transfer belt 16 that is stretched around the drive roller 14 and the driven roller 15 so as to be able to run around, and the intermediate transfer belt with respect to the photosensitive drum 10 of each process unit 9. 16 is composed of a primary transfer roller 17 and the like arranged at opposed positions across 16. Each primary transfer roller 17 presses the inner peripheral surface of the intermediate transfer belt 16 at each position, and a primary transfer nip is formed at a place where the pressed portion of the intermediate transfer belt 16 and each photosensitive drum 10 come into contact. Has been.

  A secondary transfer roller 18 is disposed at a position opposite to the drive roller 14 of the intermediate transfer belt 16 and the drive roller 14 across the intermediate transfer belt 16. The secondary transfer roller 18 presses the outer peripheral surface of the intermediate transfer belt 16, and a secondary transfer nip is formed at a location where the secondary transfer roller 18 and the intermediate transfer belt 16 are in contact with each other.

  The paper feed unit 5 is located below the image forming apparatus 1 and includes a paper feed cassette 19 that stores paper P as a recording medium, a paper feed roller 20 that carries the paper P out of the paper feed cassette 19, and the like. ing.

  The conveyance path 6 is a conveyance path that conveys the paper P carried out from the paper feeding unit 5, and the conveyance roller pair is located in the middle of the conveyance path 6 until it reaches the paper discharge unit 8 described later in addition to the pair of registration rollers 21. Are appropriately arranged.

  The fixing device 7 is a roller-shaped rotating member (or a fixing member) heated by a heating source 26, or a roller-shaped rotating member (or a fixing member) that can pressurize the fixing roller 22 (or And a pressure roller 23 as a pressure member.

  The paper discharge unit 8 is provided on the most downstream side of the conveyance path 6 of the image forming apparatus 1. The paper discharge unit 8 is provided with a pair of paper discharge rollers 24 for discharging the paper P to the outside and a paper discharge tray 25 for stocking the discharged paper P.

  The image forming unit 2, the exposure unit 3, the transfer unit 4, and the like are image forming units for forming an image on the paper P.

  The basic operation of the image forming apparatus 1 will be described below with reference to FIG.

  In the image forming apparatus 1, when an image forming operation is started, an electrostatic latent image is formed on the surface of the photosensitive drum 10 of each process unit 9Y, 9C, 9M, 9Bk. The image information exposed to each photosensitive drum 10 by the exposure unit 3 is single-color image information obtained by separating a desired full-color image into color information of yellow, cyan, magenta, and black. An electrostatic latent image is formed on each photosensitive drum 10, and toner stored in each developing device 12 is supplied to the photosensitive drum 10 by a drum-shaped developing roller 13. It is visualized as a toner image (developer image) that is a visible image.

  In the transfer unit 4, the intermediate transfer belt 16 is driven to run in the direction of arrow A in the figure by the rotational drive of the drive roller 14. Further, each primary transfer roller 17 is applied with a constant voltage or a constant current-controlled voltage having a polarity opposite to the charging polarity of the toner. As a result, a transfer electric field is formed in the primary transfer nip, and the toner images formed on the respective photosensitive drums 10 are sequentially superimposed and transferred onto the intermediate transfer belt 16 in the primary transfer nip.

  On the other hand, when the image forming operation is started, the sheet P stored in the sheet feeding cassette 19 is moved to the transport path 6 by rotating the sheet feeding roller 20 of the sheet feeding unit 5 below the image forming apparatus 1. Sent out. The sheet P sent to the conveyance path 6 is timed by the registration roller 21 and is sent to the secondary transfer nip between the secondary transfer roller 18 and the drive roller 14. At this time, a transfer voltage having a polarity opposite to the toner charging polarity of the toner image on the intermediate transfer belt 16 is applied, and a transfer electric field is formed in the secondary transfer nip. The toner images on the intermediate transfer belt 16 are collectively transferred onto the paper P by the transfer electric field formed in the secondary transfer nip.

  The sheet P on which the toner image has been transferred is conveyed to the fixing device 7, and the sheet P is heated and pressed by the fixing roller 22 and the pressure roller 23, so that the toner image is fixed on the sheet P. Then, the paper P on which the toner image is fixed is separated from the fixing roller 22, transported by a pair of transport rollers, and discharged to the paper discharge tray 25 by the paper discharge roller 24 in the paper discharge unit 8.

  The above description is an image forming operation when a full color image is formed on the paper P. A single color image can be formed using any one of the four process units 9Y, 9C, 9M, and 9Bk. It is also possible to form two or three color images using two or three process units 9.

  Next, the cleaning device according to the first embodiment of the present invention will be described. The cleaning device of this embodiment is a cleaning device for cleaning the pressure roller 23 of the fixing device 7.

  As shown in FIG. 2, the pressure roller 23 is provided with a cleaning roller 27 as a cleaning member in contact with the pressure roller 23 in the axial direction. One end 28a of a torsion spring 28 as an urging means abuts on the rotation shaft 27a of the cleaning roller 27. The other end 28 b of the torsion spring 28 is locked to the housing 29 of the fixing device 7, and the shaft 30 is inserted into the center circle portion 28 c.

  The cleaning roller 27 is assembled to a bearing, which will be described later, and is provided so as to be movable in the direction of arrow D around the shaft 30 with one end 28a of the torsion spring 28 in contact with itself. One end 28a of the torsion spring 28 applies a biasing force in the direction of arrow F1 to the rotating shaft 27a. As a result, the cleaning roller 27 is urged in the direction of the arrow F <b> 1 and pressed against the pressure roller 23.

  The cleaning roller 27 pressed against the pressure roller 23 rotates following the rotation of the pressure roller 23. At this time, as the cleaning roller 27 rotates while being pressed against the pressure roller 23, friction is generated between the surface of the cleaning roller 27 and the surface of the pressure roller 23. The adhering matter such as toner and paper dust is removed from the surface of 23 (cleaning the surface of the pressure roller 23).

  A pressure release lever is provided at the tip of the shaft 30. By operating the pressure release lever, the contact between the fixing roller 22 and the pressure roller 23 can be released, and jamming can be easily performed. The shaft 30 is held by a housing or the like of the fixing device 7.

  FIG. 3 is a view showing a bearing 31 as a holding member to which the torsion spring 28, the cleaning roller 27, and the shaft 30 are assembled to hold the rotating shaft 27a.

  First, one end 28 a of the torsion spring 28 is inserted into the spring receiving portion 31 a of the bearing 31, and the torsion spring 28 is assembled to the bearing 31. In a state where the torsion spring 28 is assembled to the bearing 31, the central circle portion 28 c of the torsion spring 28 is aligned with the second holding hole 31 c of the bearing 31. The other end 28b is locked to a boss of the casing 29 described later.

  Then, the cleaning roller 27 is inserted into the first holding hole 31b of the bearing 31, and the shaft 30 is inserted into the second holding hole 31c.

  FIG. 4 is a view seen from the direction of arrow C in FIG. 3 and shows a state in which the torsion spring 28, the cleaning roller 27, and the shaft 30 are assembled to the bearing 31.

  When the cleaning roller 27 and the shaft 30 are respectively inserted into the bearings 31, one end 28 a of the torsion spring 28 comes into contact with the rotating shaft 27 a, and the shaft 30 is inserted into the central circle portion 28 c of the torsion spring 28. One end 28 a of the torsion spring 28 is assembled to the spring receiving portion 31 a and the other end 28 b is locked to the boss 29 a of the housing 29.

  Here, the shape of the torsion spring 28 in a state before assembly will be described. As shown in FIG. 5, the torsion spring 28 before assembly has a configuration in which the other end 28b and the center circle portion 28c, and the center circle portion 28c and the one end 28a are connected by a straight portion and arranged in a straight line. .

  Here, the boss 29a is arranged on the upper right side of FIG. 4 with respect to the bearing 31, and when the torsion spring 28 having the above shape is assembled, the bent portion 28d is provided between the other end 28b and the central circle portion 28c. The one end 28 a is assembled to the spring receiving portion 31 a and the other end 28 b is locked to the boss 29 a of the housing 29. At this time, the torsion spring 28 tries to return to the shape before assembling shown in FIG. 5, and the force in the direction of the arrow F2 acts with the bent portion 28d as a fulcrum (FIG. 6), and the direction of the arrow F2 toward the one end 28a. The power to return to work. At this time, as shown in FIG. 4, since one end 28a of the torsion spring 28 is assembled to the spring receiving portion 31a, the one end 28a presses the wall 31d of the spring receiving portion 31a in the direction of arrow F4.

  Here, as shown in FIG. 7A, the diameter of the first holding hole 31 b of the bearing 31 is set to be slightly larger than the diameter of the rotating shaft 27 a of the cleaning roller 27. Further, the diameter of the second holding hole 31 c is set to be slightly larger than the diameter of the shaft 30. As described above, the rotating shaft 27 a and the shaft 30 are inserted into the bearing 31 with a backlash provided in the hole portion of the bearing 31.

  Due to the above configuration, when the wall 31d receives a force pressing in the direction of the arrow F4, the bearing 31 tilts in the clockwise direction. Then, as shown in FIG. 7B, the wall surface of the first holding hole 31b and the rotary shaft 27a come into contact with each other at the contact points B1 and B2, and the bearing 31 is held in this posture.

  In this posture, the bearing 31 continues to receive a force in the direction of the arrow F4, and the bearing 31 continues to be pressed against the rotating shaft 27a at the contact points B1 and B2. Thus, a load can be continuously applied to the rotation of the cleaning roller 27, and the frictional force between the cleaning roller 27 and the pressure roller 23 that rotates the cleaning roller 27 is increased. For this reason, the cleaning roller 27 can appropriately remove deposits on the surface of the pressure roller 23.

  As described above, the bearing 31 of this embodiment serves as a holding member that holds the rotating shaft 27a of the cleaning roller 27, and at the same time exerts a load on the rotation of the cleaning roller 27 by being pressed against the cleaning roller 27. It also has a function to give. As a result, the number of parts of the cleaning device can be reduced and the cost of the entire device can be reduced compared to a configuration in which a load member that applies a load to the rotation of the cleaning roller 27 is separately provided.

  Furthermore, the torsion spring 28 according to the present embodiment serves to urge the cleaning roller 27 in the direction of the arrow F1 to bring the cleaning roller 27 into contact with the pressure roller 23, and at the same time, separately from the urging force, a bearing 31 also has a function of inclining the bearing 31 against the cleaning roller 27 by tilting 31 in the direction of arrow F4.

  As shown in FIG. 8, the cleaning device according to the second embodiment of the present invention is provided in contact with the fixing roller 22 and removes deposits such as toner on the surface of the fixing roller 22.

  As shown in FIG. 9, the cleaning roller 27 of the present embodiment is provided with a bearing 32 as a holding member on the rotating shaft 27a. The bearing 32 has a holding portion 32a for holding the rotating shaft 27a, and the bearing 32 holds the rotating shaft 27a so that the holding portion 32a sandwiches the rotating shaft 27a.

  The diameter of the holding part 32a is set to 5.8 mm, and the diameter of the holding part 32a is set smaller than the diameter of the rotating shaft 27a of 6.0 mm. The holding portion 32a is configured to be elastically deformable in the direction of increasing its diameter. When the holding portion 32a is elastically deformed to increase its diameter, the rotation shaft 27a can be sandwiched and the bearing 32 can hold the rotation shaft 27a. At this time, the elastically deformed holding portion 32a is acted on by a force in a direction of returning to the original diameter (decreasing the diameter), and in the direction of tightening the rotation shaft 27a from the holding portion 32a to the rotation shaft 27a (rotation). A force (in the direction toward the center) is applied to the entire circumference of the shaft 27a.

  As shown in FIG. 10, the cleaning roller 27 is provided to face the fixing roller 22, and the rotation shaft 27 a is held by the bearing 32. The bearing 32 is provided with an urging spring 33 at an end opposite to the holding portion 32 a and is urged toward the fixing roller 22 by the urging spring 33.

  By holding the rotary shaft 27 a by the bearing 32, the cleaning roller 27 receives a biasing force in a direction that the bearing 32 receives from the biasing spring 33 and is pressed against the fixing roller 22. The cleaning roller 27 is pressed against the fixing roller 22 and is driven to rotate as the fixing roller 22 rotates, so that the cleaning roller 27 can remove deposits such as toner on the surface of the fixing roller 22. it can.

  At this time, as shown in FIG. 9, when the rotation shaft 27a receives a force in the tightening direction from the holding portion 32a, the cleaning roller 27 rotates between the rotation shaft 27a and the holding portion 32a. A larger frictional force is exerted than a general bearing configuration simply holding the shaft 27a. As a result, the bearing 32 can continuously apply a larger load to the cleaning roller 27 with respect to the rotation of the cleaning roller 27 than the structure of the general bearing described above. For this reason, the frictional force between the cleaning roller 27 and the fixing roller 22 is increased, and the cleaning roller 27 can reliably remove deposits such as toner on the surface of the fixing roller 22.

  As described above, in the cleaning device of this embodiment, the bearing 32 that holds the rotating shaft 27 a of the cleaning roller 27 also has a function of applying a load to the rotation of the cleaning roller 27. Accordingly, the number of parts of the cleaning device can be reduced as compared with the configuration in which a load member that applies a load to the rotation of the cleaning roller 27 is provided separately from the holding member that holds the cleaning roller 27 (the bearing 32 of the present embodiment). The cost of the entire apparatus can be reduced.

  Although the cleaning device of the second embodiment is a device that removes deposits on the surface of the fixing roller 22, it may be configured to remove deposits on the surface of the pressure roller 23 with the same configuration. In the configuration of the second embodiment, a load is applied to the rotation of the cleaning roller 27, and the frictional force between the cleaning roller 27 and the fixing roller 22 increases, so that the surface of the fixing roller 22 may be more easily worn than usual. This may cause the formation of an abnormal image. However, by providing the pressure roller 23 with a cleaning device, the formation of the abnormal image can be prevented.

The embodiment of the present invention has been described above, but the present invention is not limited to the above-described embodiment, and it is needless to say that various modifications can be made without departing from the gist of the present invention.
The image forming apparatus according to the present invention is not limited to the color image forming apparatus shown in FIG. 1, but may be a monochrome image forming apparatus, a copying machine, a printer, a facsimile, or a complex machine thereof.

  In the description of each embodiment, the fixing member provided in the fixing device 7 is the roller-shaped fixing roller 22, but may be a pad-type or endless belt-type fixing member.

  In addition, the cleaning device of each embodiment may be a cleaning device that cleans the surfaces of rotating members such as the photosensitive drum 10 and the intermediate transfer belt 16.

DESCRIPTION OF SYMBOLS 1 Image forming apparatus 7 Fixing apparatus 22 Fixing roller (rotating member or fixing member)
23 Pressure roller (rotating member or pressure member)
27 Cleaning roller (cleaning member)
27a Rotating shaft 28 Torsion spring (biasing means)
31 Bearing (holding member)
32 Bearing (holding member)
P paper (recording medium)

JP-A-01-206382

Claims (6)

In a cleaning device having a cleaning member that contacts and rotates with the rotating member and cleans the surface thereof, and a holding member that holds the rotating shaft of the cleaning member.
A cleaning apparatus, wherein the holding member is pressed against the cleaning member. Biasing means for biasing the cleaning member toward the rotating member;
The cleaning device according to claim 1, wherein the biasing unit applies a force in a direction of pressing the holding member against the cleaning member. In a cleaning device having a cleaning member that contacts and rotates with the rotating member and cleans the surface of the rotating member, and a holding member that holds the rotating shaft of the cleaning member.
The holding member has a holding portion for holding the rotating shaft,
The cleaning device according to claim 1, wherein the holding portion has a smaller diameter than the rotation shaft, and the holding portion is elastically deformable in a direction of increasing the diameter.   An image forming apparatus comprising at least the cleaning device according to claim 1.   A fixing device having an image forming unit for forming an image on a recording medium, a fixing member for fixing the image formed on the recording medium to the surface of the recording medium, and a pressure member for pressing the fixing member; An image forming apparatus comprising at least the cleaning device according to claim 1 for cleaning the surface of the fixing member or the pressure member.   The image forming apparatus according to claim 4, wherein image formation is performed with a toner using oil-containing silica.