JP2021056291A - Belt device and image forming apparatus - Google Patents

Abstract

To facilitate work to remove, from a support member, an endless belt and a plurality of support rotating members for supporting the belt.SOLUTION: A belt device 25 comprises a support member 81 that removably supports shanks 83, 84 of a plurality of support rotating members 26A, 26B for supporting an endless belt 26, and the support member supports the shank parts such that the shank parts of the plurality of support rotating members pass through the same removable attachment path 81a formed by the support member and are removably attached in an axial orthogonal direction orthogonal to an axial direction.SELECTED DRAWING: Figure 4

Description

The present invention relates to a belt device and an image forming device.

Conventionally, there is known a belt device including a support member that detachably supports each shaft portion of a plurality of support rotating members that support the endless belt.

For example, Patent Document 1 discloses a fixing device that supports a fixing belt (endless belt) with a fixing roller and a heating roller (a plurality of supporting rotating members). In this fixing device, each bearing (shaft portion) of the fixing roller and the heating roller is supported by a side plate (support member) of the fixing device.

In a belt device such as the fixing device described above, when the endless belt or a plurality of support rotating members supporting the endless belt are replaced, the endless belt and the plurality of support rotating members are removed from the support members. Generally, in a conventional belt device, it is necessary to perform a complicated work of pulling out a part of the support rotating member from the support member in the axial direction and then removing the remaining support rotating member together with the endless belt in the axial orthogonal direction. It was.

In order to solve the above-mentioned problems, the present invention is a belt device including a support member that detachably supports each shaft portion of a plurality of support rotating members that support the endless belt, and the support member is a support member. Each shaft portion of the plurality of support rotating members is supported so that the shaft portion can be attached / detached in a direction orthogonal to the axis orthogonal to the axial direction through the same attachment / detachment passage formed in the support member. It is characterized by that.

According to the present invention, the work of removing the endless belt and the plurality of support rotating members from the support members becomes easy.

The schematic block diagram of an example of the image forming apparatus which concerns on embodiment. Explanatory drawing which shows the structural example of the tandem type image forming part of the image forming apparatus. The explanatory view which shows the structure of the fixing device in the image forming apparatus. The side view for demonstrating the structure of the support mechanism which supports the fixing roller, the heating roller, the pressure roller, etc. of the fixing device. Top view showing the fixing frame supporting the shaft portion of the fixing roller and the heating roller, and the second fixing frame and the sub face plate attached to the fixing frame. The side view which shows the fixing frame which supports the shaft part of the fixing roller and the heating roller. (A) is a side view showing a state in which the fixing frame and the pressure frame are closed. (B) is a side view showing a state in which the fixing frame is opened from the pressure frame. The side view for demonstrating the support means which supports the shaft part of the heating roller in the fixing device. The side view which shows the pinching release state which released the pinching state of the shaft part of the heating roller by the 1st sheet metal and the 2nd sheet metal by rotating a 1st sheet metal around a rotation shaft on a fixing frame.

Hereinafter, embodiments will be described with reference to the drawings.
FIG. 1 is a schematic configuration diagram of an example of an image forming apparatus according to the present embodiment.
Referring to FIG. 1, the image forming apparatus 1 of the present embodiment is mounted on the apparatus main body (printer unit) 100, the paper feed table 200 which is the recording material supply unit on which the apparatus main body is mounted, and the apparatus main body 100. It is provided with a scanner 300 as an image reading device. Further, the image forming apparatus 1 of the present embodiment includes an automatic document transporting apparatus (ADF) 400 mounted on the scanner 300.

The apparatus main body 100 is provided with an intermediate transfer belt 10 as an intermediate transfer body composed of an endless belt which is an image carrier in the center thereof. The intermediate transfer belt 10 is hung on the support rollers 14, 15 and 16 as three support rotation members, and rotates in the clockwise direction in the drawing. Of these three support rollers, an intermediate transfer belt cleaning device 17 for removing residual toner remaining on the intermediate transfer belt 10 after image transfer is provided on the left side of the second support roller 15 in the drawing. Further, among the three support rollers, the tandem image forming portion 20 which is an image forming means is arranged to face each other on the belt portion stretched between the first supporting roller 14 and the second supporting roller 15.

As shown in FIG. 1, the tandem image forming unit 20 has four image forming units 18Y of yellow (Y), magenta (M), cyan (C), and black (K) along the belt moving direction of the belt portion. , 18M, 18C, 18K are arranged side by side. In the present embodiment, the third support roller 16 is used as a drive roller. Further, an exposure device 21 as an exposure means is provided above the tandem image forming unit 20.

A secondary transfer device 22 as a second transfer means is provided on the opposite side of the tandem image forming unit 20 with the intermediate transfer belt 10 in between. In the secondary transfer device 22, a secondary transfer belt 24, which is an endless belt as a transfer sheet transport member, is hung between the two rollers 231 and 232. The secondary transfer belt 24 is provided so as to be pressed against the third support roller 16 via the intermediate transfer belt 10. The secondary transfer device 22 transfers the toner image on the intermediate transfer belt 10 to the transfer sheet S as a recording material. As shown in FIG. 1, a cleaning device 170 for cleaning the outer peripheral surface of the secondary transfer belt 24 may be provided.

On the left side of the drawing of the secondary transfer device 22, a fixing device 25 for fixing the toner image transferred on the transfer sheet S is provided. The fixing device 25 has a configuration in which the pressure roller 27 is pressed against the fixing belt 26, which is an endless belt to be heated.

Further, the secondary transfer device 22 also has a sheet transfer function of transferring the transfer sheet S after transferring the toner image from the intermediate transfer belt 10 to the transfer sheet S to the fixing device 25. Further, under the secondary transfer device 22 and the fixing device 25, a sheet reversing device 28 for reversing the transfer sheet S so as to record an image on both sides of the transfer sheet S is provided in parallel with the tandem image forming unit 20. There is.

When making a copy using the image forming apparatus 1 having the above configuration, the original is set on the original table 30 of the automatic original transfer device 400. Alternatively, the automatic document transfer device 400 is opened, the document is set on the contact glass 32 of the scanner 300, and the automatic document transfer device 400 is closed and pressed by the automatic document transfer device 400. After that, when the start switch on the operation panel is pressed, when the document is set in the automatic document transfer device 400, the document is conveyed and moved onto the contact glass 32.

On the other hand, when the document is set on the contact glass 32, the scanner 300 is immediately driven to drive the first traveling body 33 and the second traveling body 34. Then, the first traveling body 33 emits light from the light source, and the reflected light from the document surface is further reflected and directed toward the second traveling body 34, which is reflected by the mirror of the second traveling body 34 and is reflected by the imaging lens 35. The image reading sensor 36 is inserted through the image reading sensor 36 to read the contents of the original.

In parallel with reading the document, the drive roller 16 is rotationally driven by a drive motor that is a drive source. As a result, the intermediate transfer belt 10 moves in the clockwise direction in the drawing, and the remaining two support rollers (driven rollers) 14 and 15 rotate along with this movement.

Further, at the same time as the document reading and the movement of the intermediate transfer belt 10, the drum-shaped photoconductors 40Y, 40M, 40C, and 40K as the image carriers are rotated in the individual image forming portions 18. Then, exposure development is performed on each of the photoconductors 40Y, 40M, 40C, and 40K using the color-coded information of yellow, magenta, cyan, and black to form a monochromatic toner image (visual image).

A primary transfer device 62Y, which is composed of a primary transfer roller as a primary transfer means, is located at a position facing each of the photoconductors 40Y, 40M, 40C, 40K with a belt portion between the support rollers 14 and 15 of the intermediate transfer belt 10 interposed therebetween. 62M, 62C, 62K are provided. By this primary transfer device 62Y, 62M, 62C, 62K, the toner images on the photoconductors 40Y, 40M, 40C, 40K are sequentially transferred onto the intermediate transfer belt 10 so as to overlap each other, and synthesized on the intermediate transfer belt 10. Form a color toner image.

In parallel with the image forming operation, one of the paper feed rollers 42 of the paper feed table 200 is selectively rotated, and the transfer sheet S is fed out from one of the paper feed cassettes 44 provided in the paper bank 43 in multiple stages. Then, the transferred transfer sheet S is separated one by one by the separation roller 45, put into the paper feed path 46, conveyed by the transfer roller 47, guided to the paper feed path in the apparatus main body 100, and abutted against the resist roller 49. And stop. Alternatively, the paper feed roller 50 is rotated to feed out the transfer sheet S on the manual feed tray 51, separated one by one by the separation roller 52, put into the manual paper feed path 53, and similarly abutted against the resist roller 49 to stop.

Next, the resist roller 49 is rotated in time with the synthetic color toner image on the intermediate transfer belt 10, and the transfer sheet S is fed between the intermediate transfer belt 10 and the secondary transfer device 22, and the secondary transfer device 22 is used. Transfer the color toner image onto the transfer sheet S.

The transfer sheet S after the toner image is transferred is conveyed by the secondary transfer belt 24 and sent to the fixing device 25, and heat and pressure are applied by the fixing belt 26 and the pressure roller 27 by the fixing device 25 to apply the transfer toner image. To fix. After this fixing, the paper is switched by the switching claw 55, discharged by the discharge roller 56, and stacked on the paper discharge tray 57. Alternatively, it is switched by the switching claw 55 and put into the sheet reversing device 28, where it is reversed and guided to the transfer position again, an image is recorded on the back surface, and then the paper is discharged onto the paper ejection tray 57 by the ejection roller 56.

The intermediate transfer belt 10 after the toner image transfer is removed by the intermediate transfer belt cleaning device 17 from the residual toner remaining on the intermediate transfer belt 10 after the toner image is transferred, and the tandem image forming unit 20 can form the image again. Be prepared. Here, the resist roller 49 is generally grounded and used, but it is also possible to apply a bias for removing paper dust from the sheet.

Further, the apparatus main body 100 includes a toner adhesion amount sensor 310 which is an optical sensor unit composed of an optical sensor or the like as an image density detecting means for detecting the density of the toner image formed on the outer peripheral surface of the intermediate transfer belt 10. ing. The toner adhesion amount sensor 310 functions as an image density detecting means for detecting the density of the toner image on the intermediate transfer belt 10 in order to detect the toner adhesion amount on the intermediate transfer belt 10 and detect the density unevenness of the image. It is also called a toner image detection sensor or a toner adhesion amount detection sensor. The toner adhesion amount sensor 310 detects the density of the toner image of the test pattern for correction control described later, which is formed on the surface of the intermediate transfer belt 10 for use in the correction control of the image density unevenness. As shown in FIG. 1, an opposing roller 311 may be provided at a position facing the toner adhesion amount sensor 310 with the intermediate transfer belt 10 in between.

FIG. 2 is an explanatory diagram showing a configuration example of a tandem type image forming unit of the image forming apparatus 1 according to the present embodiment.
Although the K (black) image forming unit 18K will be described here, the Y (yellow), M (magenta), and C (cyan) image forming units 18Y, 18M, and 18C have the same configuration. There is.

As shown in FIG. 2, for example, the image forming unit 18K has a charging device 60K as a charging means, a potential sensor 70K, a developing device 61K as a developing means, and a photoconductor cleaning device 63K around a drum-shaped photoconductor 40K. , Equipped with static elimination device, etc.

During the image forming operation, the photoconductor 40K is rotationally driven in the direction of arrow A by a drive motor as an image carrier rotation drive means. Then, the surface of the photoconductor 40K is uniformly charged by the charging device 60K, and then exposed by the write exposure L from the exposure device 21 controlled based on the image signal of the original or the like from the scanner 300 described above. , An electrostatic latent image is formed. The color image signal based on the image data from the scanner 300 is subjected to image processing such as color conversion processing in the image processing unit, and is output to the exposure apparatus 21 as an image signal of each color of K, Y, M, and C. The exposure device 21 converts the K image signal from the image processing unit into an optical signal, scans the surface of the uniformly charged photoconductor 40K based on the optical signal, and exposes the electrostatic latent image. To form.

A development bias is applied to the developing roller 61Ka as the developing agent carrier of the developing apparatus 61K, and a developing potential which is a potential difference is formed between the electrostatic latent image on the photoconductor 40K and the developing roller 61Ka. There is. Due to this development potential, the toner on the developing roller 61Ka is transferred from the developing roller 61Ka to the electrostatic latent image of the photoconductor 40K, so that the electrostatic latent image is developed and the toner image is formed. Further, a toner concentration sensor 312K capable of detecting the toner concentration in the developing agent is provided on the bottom surface of the developing agent conveying portion in which the developing agent conveying screw 61Kb in the developing apparatus 61K is arranged.

The K toner image formed on the photoconductor 40K is primarily transferred onto the intermediate transfer belt 10 by the primary transfer device 62K. After the toner image is transferred to the photoconductor 40K, the residual toner is cleaned by the photoconductor cleaning device 63K, and the charge is removed by the static elimination device to prepare for the next image formation. Similarly, the image forming units 18Y, 18M, 18C are provided with a charging device, a potential sensor, a developing device, a photoconductor cleaning device, a static elimination device, and the like around the drum-shaped photoconductors 40Y, 40M, 40C. Then, toner images of Y, M, and C are formed on the photoconductors 40Y, 40M, and 40C, and these are superposed on the intermediate transfer belt 10 and primarily transferred.

In the image forming apparatus 1 having the above configuration, the exposure apparatus 21 and the charging apparatus 60Y, 60M, 60C, 60K function as latent image forming means for forming an electrostatic latent image on the surface of the photoconductors 40Y, 40M, 40C, 40K. .. Further, the exposure device 21, the charging devices 60Y, 60M, 60C, 60K and the developing devices 61Y, 61M, 61C, 61K function as toner image forming means for forming a toner image on the surfaces of the photoconductors 40Y, 40M, 40C, 40K. To do.

Further, the image forming apparatus 1 of the present embodiment has a photo interrupter 71K as a rotation position detecting means capable of detecting the rotation position of the photoconductor 40K and a photo interrupter 72K as a rotation position detecting means capable of detecting the rotation position of the developing roller 61Ka. And have. The photo interrupter 71K and the photo interrupter 72K optically detect the rotational positions of the photoconductor 40K and the developing roller 61Ka, which are rotating members, respectively. In this photo interrupter, for example, a light emitting element and a light receiving element are arranged so as to face each other, and a detected portion such as a rotating position detecting filler provided in a rotating moving portion of a rotating member passes between them to transmit light. By blocking, the rotational position of the rotating member is detected. For example, if one notch is formed around the rotation position detection filler that rotates integrally with the photoconductor 40K, when the photoconductor 40K rotates, the light reaches the light receiving portion once per round, so that the light is photosensitive. The rotation position of the body 40K can be detected. The rotation position detecting means for detecting the rotation position of the photoconductor 40K and the developing roller 61Ka, which are the rotating members, may be other than the photo interrupter.

FIG. 3 is an explanatory diagram showing a configuration of a fixing device 25 as a belt device in the image forming device 1 according to the present embodiment.
The fixing device 25 of the present embodiment has a configuration in which the pressure roller 27 is pressed against the fixing belt 26 spanned between the fixing roller 26A which is a drive support rotating member and the heating roller 26B which is a driven support rotating member. It has become. Further, the fixing device 25 of the present embodiment includes an induction heating device 26C that heats the heating roller 26B by a non-contact heating method based on an induction heating method (IH method). The induction heating device 26C includes an exciting coil that generates an alternating magnetic field for inducing heat generation of the heat generating layer of the heating roller 26B.

In the fixing device 25 of the present embodiment, the heating roller 26B also functions as a tension roller and is urged in the direction of arrow F1 in FIG. In the fixing device 25 of the present embodiment, the fixing belt 26 is heated by the heat of the heating roller 26B heated by the induction heating device 26C, and the transfer sheet passes through the fixing nip between the heated fixing belt 26 and the pressure roller 27. The toner image on S is fixed to the transfer sheet S by heat and pressure.

The fixing device 25 of the present embodiment has a unit configuration that can be attached to and detached from the main body of the image forming device 1. The driving force for driving the fixing roller 26A is transmitted by a driving force transmission mechanism from a driving source provided on the main body side of the image forming apparatus 1.

FIG. 4 is a side view for explaining the configuration of a support mechanism that supports the fixing roller 26A, the heating roller 26B, the pressure roller 27, and the like of the fixing device 25.
FIG. 5 is a top view showing a fixing frame 81 that supports the shaft portions of the fixing roller 26A and the heating roller 26B, and a second fixing frame 86 and a sub face plate 87 that are attached to the fixing frame 81.

The fixing device 25 of the present embodiment includes a fixing frame 81 and a pressure frame 82 as side plates of the fixing device 25 on both sides of the fixing roller 26A, the heating roller 26B, and the pressure roller 27 in the axial direction. The fixing frame 81 as a support member supports the fixing rollers 26A and the heating rollers 26B shafts 83 and 84, which are support rotating members, and the pressure frame 82 as an opposing member is a pressure roller which is a contact rotating member. Supports the shaft portion 85 of 27. Each of the shaft portions 83, 84, and 85 of the fixing roller 26A, the heating roller 26B, and the pressure roller 27 is composed of ball bearings.

A pressurizing lever 27A is rotatably attached to the pressurizing frame 82 about a lever rotating shaft 27B. In the used state, the pressurizing lever 27A presses the shaft portion 85 of the pressurizing roller 27 toward the fixing roller 26A, whereby the pressurizing roller 27 presses the pressing force F2 on the portion of the fixing belt 26 around the fixing roller 26A. Is pressed with.

FIG. 6 is a side view showing a fixing frame 81 that supports the shaft portions 83 and 84 of the fixing roller 26A and the heating roller 26B.
In the fixing frame 81, the fixing roller 26A and the heating roller 26B in a state where the fixing belt 26 is wound can be attached and detached in the direction orthogonal to the axis orthogonal to the axial direction of the roller axis. The attachment / detachment passage 81a for making the shaft portions 83 and 84 of 26B movable (detachable) in the direction orthogonal to the axis is provided. By attaching and detaching the fixing roller 26A and the heating roller 26B in which the fixing belt 26 is wound in this way, it is compared with the conventional work of pulling out the fixing roller 26A or the heating roller 26B in the axial direction and then taking out the fixing belt 26. As a result, there are few work procedures and the work becomes easy.

The attachment / detachment passage 81a of the fixing frame 81 is formed by a notch of the fixing frame 81, and the shaft portion 83 of the heating roller 26B is located near the end portion 81b of the attachment / detachment passage 81a, and is in the middle of the attachment / detachment passage 81a. The shaft portion 84 of the fixing roller 26A is located in the recessed portion 81c as a certain positioning portion. When removing the fixing roller 26A and the heating roller 26B in which the fixing belt 26 is wound, it is necessary to pull out the shaft portions 83, 84 of the fixing roller 26A and the heating roller 26B from the entrance / exit of the attachment / detachment passage 81a in the direction of the arrow B. However, in the usage state as shown in FIG. 7A, the entrance / exit of the attachment / detachment passage 81a is blocked by the pressurizing frame 82 as an opposing member, the pressurizing roller 27 supported by the pressurizing frame 82, and the like. Therefore, the fixing roller 26A and the heating roller 26B cannot be removed.

Therefore, in the present embodiment, the shaft support portion 81d of the fixing frame 81 is attached to the rotation shaft 82a of the pressure frame 82, and the fixing frame 81 is attached to the pressure frame 82 by such a rotation mechanism. It can rotate around the rotation shaft 82a. As a result, the fixing frame 81 is rotated so that the entrance / exit of the attachment / detachment passage 81a of the fixing frame 81 faces upward as shown in FIG. 7B, so that the entrance / exit of the attachment / detachment passage 81a is not blocked. It is possible to have a good posture (doorway open state).

By setting the doorway open state, the shaft portions 83 and 84 of the fixing roller 26A and the heating roller 26B can be pulled out from the doorway of the attachment / detachment passage 81a in the direction of arrow B, and the fixing belt 26 is wound and fixed. The roller 26A and the heating roller 26B can be removed in the direction orthogonal to the axis (upper side in FIG. 7).

At this time, in the present embodiment, the shaft portions 83 and 84 of the fixing roller 26A and the heating roller 26B are removed in the axial orthogonal direction through the same attachment / detachment passage 81a. As a result, the shaft portion 83 of the heating roller 26B is also pulled out from the attachment / detachment passage 81a together with the fixing belt 26 only by grasping and pulling out the fixing roller 26A supported on the entrance / exit side of the attachment / detachment passage 81a. If the shaft portions 83 and 84 of the fixing roller 26A and the heating roller 26B are removed in the direction orthogonal to the axis through separate attachment / detachment passages, the shaft portions 83 and 84 are individually pulled out from the respective attachment / detachment passages. Work is required. On the other hand, according to the present embodiment, the shaft portion 83 of the heating roller 26B is also pulled out together with the fixing belt 26 only by pulling out the shaft portion 84 of the fixing roller 26A from the attachment / detachment passage. Therefore, the fixing belt 26 and the fixing roller 26A and the heating roller 26B that support the fixing belt 26 can be removed at one time by a single pulling-out operation, which facilitates the work.

In the present embodiment, since the heating roller 26B functions as a tension roller as described above, an external force in the direction of arrow F1'in FIG. 4 acts on the fixing roller 26A via the fixing belt 26. Further, by pressurizing the fixing roller 26A by the pressurizing roller 27, an external force in the direction of reference numeral F2 in FIG. 4 also acts. Therefore, it is required to firmly position the shaft portion 84 of the fixing roller 26A so that the position of the fixing roller 26A does not displace even if these external forces are received.

However, in the present embodiment, the attachment / detachment passage 81a is formed in the fixing frame 81 so that the fixing roller 26A and the heating roller 26B in the state where the fixing belt 26 is wound can be removed in the direction orthogonal to the axis, and the attachment / detachment passage 81a is fixed at the intermediate portion of the attachment / detachment passage 81a. It is necessary to position the shaft portion 84 of the roller 26A. Due to such a configuration, the region of the fixing frame 81 (the region of the recessed portion 81c) for abutting and positioning the shaft portion 84 of the fixing roller 26A is small, and the shaft portion 84 of the fixing roller 26A can be formed only by the fixing frame 81. It is difficult to position it firmly.

Therefore, in the present embodiment, as shown in FIGS. 4 and 5, the second fixing frame 86 as a regulating member for positioning the shaft portion 84 of the fixing roller 26A and the fixing member are used separately from the fixing frame 81. A sub face plate 87 is provided. The second fixing frame 86 abuts on the shaft portion 84 of the fixing roller 26A from the terminal side (heating roller 26B side) of the attachment / detachment passage 81a to position the shaft portion 84 of the fixing roller 26A. The second fixing frame 86 is screwed to the sub face plate 87, and the sub face plate 87 is positioned with the fixing frame 81 by a pin or a boss and screwed to be fixed to the fixing frame 81.

If the second fixing frame 86 is directly fixed to the fixing frame 81, for example, when the fixing roller 26A is replaced, the shaft portion 84 of the replaced fixing roller 26A may not be properly positioned due to a dimensional error or the like. .. In order to cope with this, it is necessary to form an elongated hole or the like for adjusting the fixing position of the second fixing frame 86 in the fixing frame 81, but it may cause a problem such as lowering the strength of the fixing frame 81. There is.

As in the present embodiment, the sub-face plate 87 is positioned with a pin with respect to the fixing frame 81, and the sub-face plate 87 can be fixed at the same position as before the replacement even after the replacement, and the sub-face plate 87 is passed through the sub-face plate 87. (Ii) If the fixing frame 86 is fixed to the fixing frame 81, the second fixing frame 86 can be attached to the sub-face plate 87 in a position-adjustable manner, which causes problems such as a decrease in the strength of the fixing frame 81. However, the shaft portion 84 of the fixing roller 26A can be appropriately positioned even for the fixing roller 26A after replacement.

As a result, the external force F2 input from the pressure roller 27 to the shaft portion 84 of the fixing roller 26A is mainly received by the recessed portion 81c of the fixing frame 81 that abuts on the shaft portion 84 of the fixing roller 26A, and receives the fixing belt 26. The tension force F1'input to the shaft portion 84 of the fixing roller 26A via the fixing roller 26A can be mainly received by the second fixing frame 86. As a result, the shaft portion 84 of the fixing roller 26A can be firmly positioned so that the position of the fixing roller 26A does not displace even when these external forces are received.

Here, the fixing device 25 of the present embodiment adopts an induction heating method (IH method), and has a configuration in which the heating roller 26B is induced to generate heat by the induction heating device 26C. Therefore, in order to realize appropriate induction heating, it is desirable to keep the distance between the induction heating device 26C and the heating roller 26B constant. On the other hand, since the heating roller 26B of the present embodiment functions as a tension roller as described above, it has a configuration capable of being displaced in the direction orthogonal to the axis. Therefore, the induction heating device 26C is required to be configured so as to be integrally displaced with the heating roller 26B so as to follow the displacement of the heating roller 26B.

At this time, the induction heating device 26C may be attached to the heating roller 26B in a non-detachable state, but in this case, when the fixing roller 26A and the heating roller 26B in which the fixing belt 26 is wound are removed, The induction heating device 26C will also be removed integrally. Since it is essentially unnecessary to remove the induction heating device 26C for work such as replacement of the fixing belt 26, if the induction heating device 26C is also integrally removed, the work load will increase.

FIG. 8 is a side view for explaining the supporting means for supporting the shaft portion 83 of the heating roller 26B in the present embodiment.
In the present embodiment, the shaft portion 83 of the heating roller 26B, which is a support rotating member, is sandwiched between the first sheet metal 88A and the second sheet metal 88B, which are two sandwiching members, and the first sheet metal 88A and the second sheet metal 88B are sandwiched between them. Is supported by a fixing frame 81 as a supporting base material so that the heating roller 26B can be moved in the displacement direction.

Specifically, the first sheet metal 88A and the second sheet metal 88B are attached to the fixing frame 81 so as to be rotatable around the same rotating shaft 81e provided on the fixing frame 81. More specifically, the first sheet metal 88A and the second sheet metal 88B are supported at positions deviated from each other in the axial direction of the rotating shaft 81e. Then, in the sandwiched state in which the shaft portion 83 of the heating roller 26B is sandwiched between the first sheet metal 88A and the second sheet metal 88B, the first sheet metal 88A and the second sheet metal 88B partially overlap each other when viewed from the axial direction. It is configured in.

Mounting bosses 88Aa and 88Ba to which each end of the holding spring 88C, which is a compression spring, is attached to the first sheet metal 88A and the second sheet metal 88B, respectively, sandwich the shaft portion 83 of the heating roller 26B and rotate the shaft 81e. It is provided on the opposite side of. As a result, the first sheet metal 88A and the second sheet metal 88B rotate in opposite directions around the rotation shaft 81e due to the urging force of the holding spring 88C attached between the mounting boss portions 88Aa and 88Ba. Be urged. As a result, the shaft portion 83 of the heating roller 26B can be sandwiched between the first sheet metal 88A and the second sheet metal 88B by this urging force.

The first sheet metal 88A and the second sheet metal 88B in a state where the shaft portion 83 of the heating roller 26B is sandwiched can rotate around the rotation shaft 81e on the fixing frame 81, and the heating roller 26B is rotated along with this rotation. The shaft portion 83 of the above can be moved along the attachment / detachment passage 81a in the direction of contacting and separating from the fixing roller 26A. Of the two sheet metals 88A and 88B, the first sheet metal 88A, which is an entrance / exit side sandwiching member located on the entrance / exit side of the attachment / detachment passage 81a with respect to the shaft portion 83 of the heating roller 26B, has one end of a tension spring 88D which is a compression spring. A spring mounting portion 88Ab for mounting the spring is provided. The other end of the tension spring 88D is attached to the spring attachment portion 81f provided on the fixing frame 81. As a result, the first sheet metal 88A is urged against the fixing frame 81 in the direction of rotating counterclockwise in FIG. 8 by the urging force of the tension spring 88D. As a result, the urging force urges the shaft portion 83 of the heating roller 26B via the first sheet metal 88A in the direction away from the fixing roller 26A along the attachment / detachment passage 81a.

At this time, the shaft portion 84 of the fixing roller 26A that supports the fixing belt 26 together with the heating roller 26B is positioned and fixed to the fixing frame 81 by the second fixing frame 86 that is fixed via the sub face plate 87. Therefore, tension is applied to the fixing belt 26 by the urging force of the tension spring 88D acting on the shaft portion 83 of the heating roller 26B via the first sheet metal 88A.

Due to the tension fluctuation of the fixing belt 26 or the like, the shaft portion 83 of the heating roller 26B is displaced along the attachment / detachment passage 81a in the contact / separation direction with the fixing roller 26A. In the present embodiment, the induction heating device 26C is supported by the second sheet metal 88B so that the heating roller 26B can be displaced integrally with the heating roller 26B following the displacement of the heating roller 26B. That is, the second sheet metal 88B sandwiches the shaft portion 83 of the heating roller 26B with the first sheet metal 88A by the urging force of the holding spring 88C, and in that state, the shaft portion 83 of the heating roller 26B and the first sheet metal 88A It is configured to rotate around the rotation shaft 81e integrally with the rotation shaft 81e. Therefore, when the shaft portion 83 of the heating roller 26B is displaced along the attachment / detachment passage 81a due to the tension fluctuation of the fixing belt 26 or the like, the second sheet metal 88B is also integrally displaced (rotated) and supported by the second sheet metal 88B. The induction heating device 26C is also displaced integrally.

By removing the holding spring 88C and the tension spring 88D described above, the first sheet metal 88A can rotate around the rotation shaft 81e on the fixing frame 81 in the direction of the arrow C, as shown in FIG. .. As a result, the shaft portion 83 of the heating roller 26B is in the pinching release state in which the pinching state by the first sheet metal 88A and the second sheet metal 88B is released. Further, as shown in FIG. 9, the first sheet metal 88A is in a state of being separated from the shaft portion 83 of the heating roller 26B passing through the attachment / detachment passage 81a, so that the shaft portion 83 of the heating roller 26B is first. The sheet metal 88A and the second sheet metal 88B are taken out along the attachment / detachment passage 81a while remaining on the fixing frame 81 side. Therefore, the shaft portion 83 of the heating roller 26B can be taken out along the attachment / detachment passage 81a while the induction heating device 26C supported by the second sheet metal 88B is also left on the fixing frame 81 side.

As described above, in the present embodiment, the shaft portion 83 of the heating roller 26B is sandwiched between the two sheet metals 88A and 88B, and the induction heating device 26C is attached to the second sheet metal 88B of the two sheet metals 88A and 88B. Is supported to realize the integral displacement of the heating roller 26B and the induction heating device 26C, while the first sheet metal 88A is configured to be detachable to a position where it does not interfere with the shaft portion 83 of the heating roller 26B passing through the attachment / detachment passage 81a. The shaft portion 83 of the heating roller 26B can be taken out from the attachment / detachment passage 81a. Therefore, in the configuration including the induction heating device 26C that is integrally displaced with the heating roller 26B that is displaced in the axially orthogonal direction, the heating roller 26B can be attached and detached in the axially orthogonal direction.

In the present embodiment, the fixing device provided in the image forming apparatus has been described as an example, but the present invention can also be applied to other belt devices in the image forming apparatus and belt devices in devices other than the image forming apparatus.

The above description is an example, and the effect peculiar to each of the following aspects is exhibited [first aspect].
In the first aspect, a support member (for example, fixing) that detachably supports each shaft portion 83, 84 of a plurality of support rotating members (for example, fixing roller 26A and heating roller 26B) that support the endless belt (for example, fixing belt 26). A belt device (for example, a fixing device 25) provided with a frame 81), wherein each shaft portion of the plurality of support rotating members passes through the same attachment / detachment passage 81a formed in the support member. It is characterized in that each shaft portion is supported so that it can be attached and detached in a direction orthogonal to the axis orthogonal to the axial direction.
According to this aspect, each shaft portion of the plurality of support rotating members supported by the support member can be attached / detached in the direction orthogonal to the axis through the same attachment / detachment passage formed in the support member. According to this, each shaft portion of the plurality of support rotating members with the endless belt wound around can be taken out together from the attachment / detachment passage. Therefore, since it is not necessary to pull out a part of the support rotating members in the axial direction, the work of removing the endless belt and the plurality of support rotating members becomes simple.
In particular, in this embodiment, since each shaft portion of the plurality of support rotating members is removed in the direction orthogonal to the axis through the same attachment / detachment passage, one support rotation member supported on the entrance / exit side of the attachment / detachment passage is gripped. By simply pulling it out, the shaft portion of the other support rotating member is pulled out from the attachment / detachment passage together with the endless belt. If each shaft portion of the plurality of support rotating members is removed in the direction orthogonal to the axis through separate attachment / detachment passages, it is necessary to individually pull out each shaft portion from each attachment / detachment passage. According to this, the endless belt and the plurality of support rotating members can be removed only by pulling out one shaft portion from the attachment / detachment passage, which facilitates the work.

[Second aspect]
In the second aspect, in the first aspect, at least one support rotating member (for example, the heating roller 26B) of the plurality of support rotating members can be displaced in the axial orthogonal direction along the attachment / detachment passage. It is a tension member that is supported by the support member and applies tension to the endless belt.
Since each shaft portion of the plurality of support rotating members is removed in the direction orthogonal to the axis through the same attachment / detachment passage, at least one support rotation member is not restricted by the support member and is along the attachment / detachment passage. It can be displaced to the other support rotating member side. Therefore, the at least one support rotating member can be used as a tension member for applying tension to the endless belt. By using the at least one support rotating member as the tension member, it is not necessary to provide the tension member separately from the plurality of support rotating members, which is advantageous in terms of simplification of the configuration and space saving.

[Third aspect]
In the third aspect, in the second aspect, the shaft portion 84 of the other support rotating member (for example, the fixing roller 26A) among the plurality of support rotating members moves in the attachment / detachment passage by the tension of the endless belt. A regulating member (for example, a second fixing frame 86) for regulating the above is provided so as to be detachably attached to the supporting member.
Since each shaft portion of the plurality of support rotating members is removed in the direction orthogonal to the axis through the same attachment / detachment passage, the at least one support rotating member (tension member) side of the other support rotating member can be used. , There is a space for the detachable passage. Therefore, it is difficult to secure a sufficient area of the support member for abutting and positioning the other support rotating member so that the shaft portion does not move toward the tension member side due to the tension of the endless belt. ..
Therefore, in this embodiment, a restricting member for restricting the movement of the shaft portion of the other support rotating member in the attachment / detachment passage by the tension of the endless belt is provided, and the shaft portion of the other support rotating member is positioned. I am trying to do it. Since this restricting member is configured to be detachable from the support member, the restricting member can be removed when a plurality of support rotating members are attached / detached in the direction orthogonal to the axis through the attachment / detachment passage. It does not get in the way of putting on and taking off.

[Fourth aspect]
The fourth aspect has a fixing member (for example, a sub-face plate 87) that is positioned and fixed at a predetermined position of the support member in the third aspect, and the regulation member can be adjusted in position with respect to the fixing member. It is characterized by being attached.
If the regulating member is directly fixed to the support member, for example, when the other support rotating member is replaced, the shaft portion of the supported rotating member after the replacement may not be properly positioned due to a dimensional error or the like. In order to cope with this, it is necessary to form an elongated hole or the like for adjusting the fixing position of the regulating member in the support member, but there is a risk of causing a problem such as a decrease in the strength of the support member.
In this embodiment, the regulating member is fixed to the support member via the fixing member, and the regulating member is attached to the fixing member so as to be adjustable in position. According to this configuration, it is possible to appropriately position the shaft portion of the support rotating member after replacement without causing a problem such as reducing the strength of the support member.

[Fifth aspect]
A fifth aspect is, in any one of the first to fourth aspects, a facing member (for example, a pressure frame 82) arranged to face the entrance / exit of the attachment / detachment passage, and a rotation axis extending along an axial direction. The support member has a rotation mechanism (for example, a shaft support portion 81d and a rotation shaft 82a) that rotates the support member with respect to the facing member, and the support member has an entrance / exit due to rotation by the rotation mechanism. It is characterized in that the doorway is closed and the doorway is open so that the doorway does not face the facing member.
According to this, even in a configuration in which the facing members are arranged so as to face the entrance / exit of the attachment / detachment passage of the support members, the endless belt and the plurality of support rotating members can be easily removed.

[Sixth aspect]
In the sixth aspect, in the fifth aspect, the facing member is the endless shape on the entrance / exit side support rotation member (for example, the fixing roller 26A) supported on the entrance / exit side of the attachment / detachment passage among the plurality of support rotation members. The shaft portion 85 of the contact rotating member (for example, the pressure roller 27) that comes into contact with the belt portion is detachably supported in the direction orthogonal to the axis.
When the support member is rotated by the rotation mechanism to open the doorway, the contact rotating member can also be attached and detached in the direction orthogonal to the axis. As a result, when the contact rotating member is replaced, the supporting member is rotated by the rotating mechanism to enter and exit without removing the plurality of supporting rotating members and endless belts supported by the supporting member from the supporting member. The contact rotating member can be replaced only by opening it, and the replacement work becomes easy.

[7th aspect]
In the seventh aspect, in the sixth aspect, the support member is positioned in contact with the shaft portion of the entrance / exit side support rotation member at a position where the contact force transmitted from the contact rotation member to the entrance / exit side support rotation member is received. It is characterized by having a positioning portion (recessed portion 81c) to be formed.
According to this, even if the doorway side support rotating member is configured to receive a contact force from the contact rotating member, the shaft portion of the doorway side support rotating member can be positioned by the support member.

[8th aspect]
The eighth aspect is characterized in that, in the sixth or seventh aspect, the shaft portion of the contact rotating member is formed of a ball bearing into which the rotating shaft of the contact rotating member is press-fitted.
According to this, there is no rubbing between the rotating shaft of the contact rotating member and the ball bearing, and the life of the contact rotating member can be extended.

[9th aspect]
A ninth aspect is characterized in that, in any one of the first to eighth aspects, the shaft portion of the plurality of support rotating members is composed of ball bearings into which the rotating shafts of the supporting rotating members are press-fitted. Is.
According to this, there is no rubbing between the rotating shaft of the supporting rotating member and the ball bearing, and the life of the supporting rotating member can be extended.

[10th aspect]
A tenth aspect is an image forming apparatus, characterized in that it includes a belt apparatus according to any one of the first to ninth aspects.
According to this, it is possible to provide an image forming apparatus including an endless belt and a belt apparatus which facilitates the work of removing a plurality of support rotating members.

1: Image forming device 10: Intermediate transfer belt 18: Image forming unit 20: Tandem image forming unit 21: Exposure device 22: Secondary transfer device 25: Fixing device 26: Fixing belt 26A: Fixing roller 26B: Heating roller 26C: Induction Heating device 27: Pressurizing roller 27A: Pressurizing lever 27B: Lever rotating shaft 40: Photoreceptor 60: Charging device 61: Developing device 62: Primary transfer device 81: Fixing frame 81a: Detachable passage 81b: End portion 81c: Recess Part 81d: Shaft support 81e: Rotating shaft 81f: Spring mounting 82: Pressurizing frame 82a: Rotating shaft 83: Heating roller shaft 84: Fixing roller shaft 85: Pressurizing roller shaft 86: Second fixing frame 87: Sub face plate 88A: First sheet metal 88B: Second sheet metal 88C: Holding spring 88D: Tension spring

Japanese Unexamined Patent Publication No. 2006-133359

Claims (10)

A belt device provided with a support member that detachably supports each shaft portion of a plurality of support rotating members that support the endless belt.
The support member is provided so that each of the shaft portions of the plurality of support rotating members can be attached and detached in an axially orthogonal direction orthogonal to the axial direction through the same attachment / detachment passage formed in the support member. A belt device characterized by supporting a shaft portion. In the belt device according to claim 1,
At least one of the plurality of support rotating members is supported by the support member so that the shaft portion can be displaced in the direction orthogonal to the axis along the attachment / detachment passage, and tension is applied to the endless belt. A belt device characterized by being a tension member. In the belt device according to claim 2,
A restricting member that restricts the shaft portion of the other support rotating member among the plurality of support rotating members from moving in the attachment / detachment passage by the tension of the endless belt is provided detachably from the support member. A belt device characterized by being used. In the belt device according to claim 3,
It has a fixing member that is positioned and fixed at a predetermined position of the support member.
The belt device is characterized in that the restricting member is attached to the fixing member in a position-adjustable manner. In the belt device according to any one of claims 1 to 4.
Opposing members arranged to face the entrance and exit of the attachment / detachment passage, and
It has a rotation mechanism that rotates the support member with respect to the opposing member around a rotation axis extending along an axial direction.
The support member is a belt device characterized in that, by rotation by the rotation mechanism, the doorway is switched between a doorway closed state in which the doorway faces the facing member and a doorway open state in which the doorway does not face the facing member. In the belt device according to claim 5,
The facing member shafts a shaft portion of the contact rotating member that abuts on the portion of the endless belt on the entrance / exit side support rotating member supported on the entrance / exit side of the attachment / detachment passage among the plurality of supporting rotating members. A belt device that is detachably supported in the orthogonal direction. In the belt device according to claim 6,
The support member is characterized by having a positioning portion that contacts and positions the shaft portion of the entrance / exit side support rotation member at a position where the contact force transmitted from the contact rotation member to the entrance / exit side support rotation member is received. Belt device. In the belt device according to claim 6 or 7.
A belt device characterized in that the shaft portion of the contact rotating member is composed of a ball bearing in which the rotating shaft of the contact rotating member is press-fitted. In the belt device according to any one of claims 1 to 8.
A belt device characterized in that the shaft portion of the plurality of support rotating members is composed of ball bearings into which the rotating shafts of the support rotating members are press-fitted. An image forming apparatus comprising the belt apparatus according to any one of claims 1 to 9.

Images