JP2018180395A - Fixing device and image forming apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a fixing device that can reduce deviation of a meandering fixing belt and correct the meander.SOLUTION: A fixing device has a fixing belt 53 stretched over a heating roller 52, and comprises: a shaft support member 60 that supports an end in the axial direction W of the heating roller 52; and a regulating member 70 that is engaged with the shaft support member 60. The shaft support member 60 is provided with an outer periphery support part 61 that covers the outer peripheral surface of the heating roller 52, and the leading end of the outer periphery support part 61 is made to be a shaft support leading end 62. The regulating member 70 is provided with a belt regulating surface 73 that covers the shaft support leading end 62, and a belt contact surface 74 that is drawn from the belt regulating surface 73 toward the center. The belt contact surface 74 is inclined such that the diameter is reduced toward the center, and is provided with a gap between its inner peripheral surface and the outer peripheral surface of the heating roller 52 at an end toward the shaft support leading end 62.SELECTED DRAWING: Figure 6

Description

  The present invention relates to a fixing device and an image forming apparatus in which a fixing belt is stretched between a heating roller and a fixing roller.

  In recent years, a belt system using an endless fixing belt has been proposed as a fixing device used in an electrophotographic image forming apparatus such as a copying machine or a printer. In a belt system in which a fixing belt is stretched between a heating roller and a fixing roller, the end of the roller is supported by a member.

  FIG. 10 is an enlarged explanatory view showing the end portion of the roller in the conventional fixing device. In the conventional fixing device, rollers 101 having partially different diameters are used. That is, at the end portion 101a supported by the support member 103, the diameter is smaller than the portion (center portion of the roller 101) on which the belt 102 is stretched. Therefore, even if the belt 102 is offset to the side of the end portion 101a, it strikes the support member 103. Therefore, even if there is a gap between the support member 103 and the end portion 101a, there is no concern that the belt 102 sinks. It was not.

  Further, in order to restrict the meandering of the belt, it has been proposed to attach a meandering restricting member or a slip stopper to the end of the roller (see, for example, Patent Document 1 and Patent Document 2).

JP, 2014-153512, A Unexamined-Japanese-Patent No. 11-133771

  In the fixing device described in Patent Document 1, meandering restricting members for restricting meandering are disposed at both ends in the axial direction of the fixing roller, and the tapered outer peripheral portion facing the inner circumferential surface of the belt is the meandering restricting member Provided in In the fixing device described in Patent Document 1, the flange member to which the meandering restriction member is adhered is attached to the fixing roller itself, so that the structure such as processing of the fixing roller is complicated, and the diameter of the fixing roller is increased. There are concerns about such issues.

  In the fixing device described in Patent Document 2, the anti-slip member is attached to the end of the roller, and the anti-slip member is perpendicular to the base through which the roller is inserted and the inner circumferential surface of the base There is provided a first wall surface portion which rises up and a second wall surface portion which is inclined and extended from the first wall surface portion. Also in the fixing device described in Patent Document 2, the anti-slip member is attached to the roller, and there is a concern about the same as the fixing device described in Patent Document 1. Further, the first wall surface portion, which is first in contact with the end of the meandering belt, rises perpendicularly to the outer peripheral surface of the roller, and there is a problem that it can only receive the meandering belt so that it does not further deviate.

  The present invention has been made to solve the above-described problems, and it is an object of the present invention to provide a fixing device and an image forming apparatus capable of performing the correction of the meandering while suppressing the deviation of the meandering fixing belt. Do.

  The fixing device according to the present invention is a fixing device in which a fixing belt is stretched around a heating roller and a fixing roller, and a shaft supporting member for supporting an axial end of the heating roller, and the shaft supporting member An outer peripheral support portion covering an outer peripheral surface of the heating roller at an axial end of the heating roller, and the shaft supporting member is provided with the outer peripheral supporting portion of the heating roller in the axial direction When the distal end of the outer peripheral support portion positioned at the center side is a shaft support tip, the restriction member covers the belt control surface covering the shaft support tip in the axial direction, and the heating in the axial direction from the belt control surface A belt contact surface extending toward the center of the roller, and the belt contact surface is inclined so that the diameter decreases toward the center of the heating roller in the axial direction; At the end of the tip side, Wherein the gap between the outer peripheral surface of the heating roller and the peripheral surface is provided.

  In the fixing device according to the present invention, the restriction member may be engaged with the shaft support member in a state where a gap is provided in the axial direction.

  In the fixing device according to the present invention, the restricting member includes a restricting facing portion facing the outer peripheral supporting portion in a direction orthogonal to the axial direction, and the restricting facing portion projects toward the outer peripheral supporting portion. A regulation engagement portion is provided, and the outer circumferential support portion is provided with a support engagement portion projecting toward the regulation opposite portion, and the support engagement portion is in the axial direction from the regulation engagement portion. It is good also as composition which is located in the center side of the above-mentioned heating roller, and estranged from the above-mentioned regulation engaging part in the above-mentioned axial direction.

  In the fixing device according to the present invention, the restriction member may be formed of the same material as the heating roller.

  In the fixing device according to the present invention, the heating roller may have a cylindrical shape with a uniform diameter in the axial direction.

  In the fixing device according to the present invention, a control inclined surface is provided on the outer periphery of the belt control surface in a direction toward the end of the heat roller in the axial direction as it is separated from the heat roller. It may be

  In the fixing device according to the present invention, the restriction member may be provided at both ends of the heating roller.

  In the fixing device according to the present invention, the regulating member may be provided at one end of the heating roller.

  An image forming apparatus according to the present invention includes the fixing device according to the present invention.

  According to the present invention, by providing the regulating member covering the tip of the shaft supporting member, it is possible to suppress the meandering fixing belt from invading the gap between the shaft supporting member and the heating roller. Further, the meandering of the fixing belt is suppressed by riding on the inclined belt contact surface. Further, in the regulating member, the belt abutting surface is pressed by the fixing belt and inclined, and the belt regulating surface located opposite to the pressed side is pushed out toward the center side, and the fixing belt is pushed back toward the center side. It can be corrected.

FIG. 1 is a schematic view of an image forming apparatus according to a first embodiment of the present invention. FIG. 2 is a schematic top view showing the fixing device shown in FIG. It is a schematic side view which extracts and shows a control member. It is a schematic sectional drawing of the limitation member shown in FIG. It is a schematic plan view of the control member shown in FIG. It is principal part sectional drawing which expands and shows the edge part vicinity of a heating roller. FIG. 7 is a cross-sectional view of an essential part showing the vicinity of the end of the heating roller in an enlarged manner in a state in which the fixing belt meanders. FIG. 6 is a cross-sectional view of an essential part showing the vicinity of the end of the heating roller in an enlarged manner in a state where the fixing belt further meanders. FIG. 6 is a schematic top view showing a fixing device according to a second embodiment of the present invention. FIG. 10 is an enlarged explanatory view showing an end portion of a roller in a conventional fixing device.

First Embodiment
Hereinafter, an image forming apparatus according to a first embodiment of the present invention will be described with reference to the drawings.

  FIG. 1 is a schematic view of an image forming apparatus according to the first embodiment of the present invention.

  The image forming apparatus 1 includes an image forming unit 1a that forms a multi-color image and a single-color image on a predetermined sheet according to image data transmitted from the outside.

  The image forming unit 1a includes an exposure device 11, a developing device 12, a photosensitive drum 13, a cleaner device 14, a charger 15, an intermediate transfer belt device 16, a fixing device 17, a paper feed tray 18, a paper discharge tray 19, and sheet conveyance. A device 20 is provided.

  Image data handled in the image forming apparatus 1 corresponds to a color image using each color of black (K), cyan (C), magenta (M), and yellow (Y). Therefore, the developing device 12, the photosensitive drum 13, the charger 15, and the cleaner device 14 are provided four by four so as to form four types of latent images corresponding to the respective colors, respectively for black, cyan, magenta and yellow. These are set up to constitute four image stations.

  The photosensitive drum 13 is disposed substantially at the center of the image forming unit 1 a of the image forming apparatus 1. The charger 15 uniformly charges the surface of the photosensitive drum 13 to a predetermined potential. The exposure device 11 exposes the surface of the photosensitive drum 13 to form an electrostatic latent image. The developing device 12 develops the electrostatic latent image on the surface of the photosensitive drum 13 to form a toner image on the surface of the photosensitive drum 13. A toner image of each color is formed on the surface of each photosensitive drum 13 by the above-described series of operations. The cleaner device 14 removes and collects residual toner on the surface of the photosensitive drum 13 after development and image transfer.

  The intermediate transfer belt device 16 is disposed on the upper side of the photosensitive drum 13 and includes the intermediate transfer belt 21, the intermediate transfer belt drive roller 22, the intermediate transfer belt driven roller 23, the intermediate transfer roller 24, the intermediate transfer belt cleaning device 25, and the tension. A roller 26 is provided. Incidentally, four intermediate transfer rollers 24 are provided corresponding to the image stations of respective colors for Y, M, C, and K.

  The intermediate transfer belt driving roller 22, the intermediate transfer belt driven roller 23, the intermediate transfer roller 24, and the tension roller 26 stretch the intermediate transfer belt 21 to extend the surface of the intermediate transfer belt 21 in a predetermined direction (in FIG. In the direction of mark C).

  The intermediate transfer belt 21 circulates in the direction of arrow C, and the residual toner is removed and collected by the intermediate transfer belt cleaning device 25, and toner images of respective colors formed on the surfaces of the respective photosensitive drums 13 are sequentially transferred. The color toner images are formed on the surface of the intermediate transfer belt 21.

  The image forming unit 1a further includes a secondary transfer device 27 including a transfer roller 27a. The transfer roller 27 a has a nip area formed with the intermediate transfer belt 21, and nips and conveys the sheet P conveyed through the sheet conveyance path S in the nip area. When the sheet P passes through the nip area, the toner image on the surface of the intermediate transfer belt 21 is transferred.

  The paper feed tray 18 is a tray for accumulating the paper P used for image formation, and is provided below the exposure device 11. Further, the paper discharge tray 19 is provided on the upper side of the image forming unit 1a, and is a tray on which the sheet P on which an image has been formed is placed.

  Further, the image forming unit 1a of the image forming apparatus 1 is provided with a sheet conveying device 20 for feeding the sheet P of the sheet feeding tray 18 to the sheet discharge tray 19 via the secondary transfer device 27 and the fixing device 17. ing. The sheet conveying device 20 has an S-shaped sheet conveying path S, and along the sheet conveying path S, the pickup roller 31, the pair of separation rollers 31a and 31b, the registration roller 32, the pre-registration roller 33, and the fixing device 17. , And the discharge roller 34 are disposed.

  The pickup roller 31 is a feeding roller provided near the end of the sheet feeding tray 18 and feeding sheets P one by one from the sheet feeding tray 18 to the sheet conveyance path S. One separation roller 31a conveys the sheet P to the sheet conveyance path S while passing the sheet P between the other separation roller 31b and separating the sheet P one by one. The registration roller 32 temporarily holds the sheet P conveyed from the sheet feeding tray 18, and conveys the sheet P to the transfer roller 27a at timing when the leading end of the toner image on the photosensitive drum 13 and the leading end of the sheet P are aligned. . The pre-registration roller 33 is a small roller for promoting and assisting the conveyance of the sheet P.

  The fixing device 17 is a belt fixing type fixing device, and the fixing belt 53 is wound around the fixing roller 51 and the heating roller 52. The fixing belt 53 can transfer heat from the heating roller 52 to the fixing roller 51. In the fixing device 17, the pressure roller 54 is pressed against the fixing roller 51 via the fixing belt 53. The fixing device 17 receives the sheet P on which an unfixed toner image is formed, and nips and conveys the sheet P between the fixing belt 53 and the pressure roller 54. The sheet P after fixing is discharged onto the discharge tray 19 by the discharge roller 34. The fixing device 17 will be described in detail with reference to FIGS. 2 to 4 described later.

  FIG. 2 is a schematic top view showing the fixing device shown in FIG.

  In FIG. 2, among the fixing device 17 shown in FIG. 1, particularly, the fixing roller 51, the heating roller 52, the pressure roller 54, and the end portion in the axial direction W of the fixing belt 53 are viewed from above The state is shown enlarged. Although not shown in FIG. 2, the fixing roller 51, the heating roller 52, the pressure roller 54, and the fixing belt 53 have a sufficiently longer structure in the axial direction W than the sheet P to be conveyed. In the following, for simplification of the description, the center side of the heating roller 52 in the axial direction W may be referred to as the center side, and the end side of the heating roller 52 in the axial direction W may be referred to as the end side. The fixing device 17 is not limited to the above-described configuration, and may include a tension roller or the like that presses the inner peripheral surface of the fixing belt 53 to apply a load.

  Both ends of the heating roller 52 in the axial direction W are supported by the shaft supporting member 60, and a heating source (not shown) is provided inside. The structure of the heating roller 52 will be described in detail with reference to FIG. 6 described later.

  The shaft support member 60 supports the end of the inserted heating roller 52, but the boundary between the heating roller 52 and the shaft support member 60 in the axial direction W is covered by the restriction member 70. Next, the regulating member 70 will be described in detail with reference to FIGS. 3 to 5.

  3 is a schematic side view showing the regulation member extracted, FIG. 4 is a schematic cross-sectional view of the regulation member shown in FIG. 3, and FIG. 5 is a schematic plan view of the regulation member shown in FIG. is there.

  The restricting member 70 has a hollow substantially cylindrical shape in which the upper surface (the end surface on the upper side in FIG. 3) and the bottom surface (the end surface on the lower side in FIG. 3) are opened. Specifically, the restricting member 70 includes, in order from the bottom surface side, the base 71, the restricting facing portion 72, the belt restricting surface 73, and the belt abutting surface 74, and the diameters are different. In the fixing device 17 shown in FIG. 2, the upper surface is located at the center side, and the bottom surface is located at the end side. Hereinafter, for the sake of explanation, the direction in which the top surface and the bottom surface face each other in the regulating member 70 will be referred to as the facing direction T.

  The outer surface of the base 71, the restriction facing portion 72, the belt restricting surface 73, and the belt contact surface 74 are formed in a circular shape when viewed from the bottom (see FIG. 5), and their diameters are appropriately set. But the centers are in agreement. The heating roller 52 is mounted so that the center of the shaft coincides with the center of the regulating member 70. In the following, for convenience of explanation, a portion overlapping with the center of the axis of the heating roller 52 may be referred to as the center of the regulating member 70.

  The base 71 is formed in an annular shape extending in the direction orthogonal to the facing direction T from the outer peripheral surface of the restriction member 70, and the shaft support member 60 is inserted from the opening of the base 71. From the inner circumferential portion of the base portion 71, a restriction facing portion 72 is provided along the opposing direction T.

  The regulation facing portion 72 is formed in a cylindrical shape whose outer peripheral surface is substantially parallel to the facing direction T, and the upper end is connected to the belt regulating surface 73. The restricting facing portion 72 is provided with a restricting engagement portion 75 projecting toward the inside. The restricting engagement portion 75 is provided closer to the end of the restricting opposing portion 72 in the opposing direction T. The restricting member 70 is engaged with the shaft support member 60 by the restricting engagement portion 75. The structure for engaging the restriction member 70 with the shaft support member 60 will be described in detail with reference to FIG. 6 described later.

  In the present embodiment, as shown in FIG. 5, the regulation engaging portions 75 are provided at four locations, and are arranged at equal intervals along the arc of the inner circle of the regulation opposing portion 72. The present invention is not limited to this, and the number of restricting engaging portions 75 may be changed, or the restricting engaging portion 75 connected over the entire circumference of the inner circle in the restricting facing portion 72 may be provided. Good.

  The belt regulating surface 73 is formed in a substantially annular shape, and the circumference of the outer circle is connected to the regulation facing portion 72, and the circumference of the inner circle is connected to the belt contact surface 74. The belt regulating surface 73 is configured to have different inclinations on the inner circumference (inner circle side) and the outer circumference (outer circle side), and a regulation flat surface 73 b and a regulation inclined surface 73 a are provided. The regulation flat surface 73b is provided on the inner periphery of the belt regulation surface 73, and extends in a direction orthogonal to the facing direction T, that is, in a direction parallel to the top and bottom surfaces. The restricting inclined surface 73 a is provided on the outer periphery of the belt restricting surface 73, and is inclined in the direction toward the end as it is separated from the center of the restricting member 70.

  The belt contact surface 74 is formed in a substantially cylindrical shape whose diameter decreases toward the upper surface side in the opposing direction T. That is, the outer side surface of the belt contact surface 74 is inclined so as to decrease in diameter toward the center. Further, the belt contact surface 74 has a uniform thickness, and the internal space narrows toward the upper surface side. That is, in the belt contact surface 74, the distance from the center of the regulating member 70 is short on the center side of the inner surface, and the distance from the center of the regulating member 70 is long on the end side of the inner surface.

  In the present embodiment, the inclination of the belt contact surface 74 etc. is emphasized and shown in consideration of the legibility of the drawing, but the present invention is not limited to this, and in consideration of the size of each part, etc. The degree of inclination may be adjusted.

  FIG. 6 is a cross-sectional view of an essential part showing the vicinity of the end of the heating roller in an enlarged manner.

  In FIG. 6, the heating roller 52, the fixing belt 53, the shaft support member 60, and the regulating member 70 in the fixing device 17 shown in FIG. 2 are extracted, and the heating roller 52 and the fixing roller 51 are in the opposite direction. The cross section is shown. In FIG. 6, only one end of the heating roller 52 is shown, and the other end of the heating roller 52 is omitted because it has a substantially similar structure.

  The heating roller 52 is formed in a hollow cylindrical shape and has a uniform diameter in the axial direction W. In the present embodiment, the heating roller 52 is formed of stainless steel and slightly expands by being heated. The regulating member 70 is also made of stainless steel, and expands in the same manner as the heating roller 52. That is, by forming the regulation member 70 and the heating roller 52 with the same material, no difference occurs in the thermal expansion coefficients of both, so that it is possible to suppress the change in the positional relationship due to the deformation due to the heating.

  The shaft support member 60 is provided with an outer peripheral support portion 61 that covers the outer peripheral surface of the heating roller 52 at an end portion of the heating roller 52 in the axial direction W. The shaft support member 60 is formed of a heat insulating material that reduces the heat transfer, so that the heat generated from the heating roller 52 and the like is not transferred to the surroundings. Since the coefficient of thermal expansion is different between the shaft supporting member 60 and the heating roller 52, the outer peripheral supporting portion 61 can be supported between the outer peripheral surface of the heating roller 52 so that it can be supported without change even if the heating roller 52 expands. There is a gap.

  The outer peripheral support portion 61 has a tip located on the center side of the heating roller 52 in the axial direction W as a shaft support tip 62. In the vicinity of the shaft support tip 62, a support engagement portion 63 projecting in a direction away from the heating roller 52 is provided. The support engagement portion 63 protrudes toward the restriction facing portion 72 in a state in which the restriction member 70 is engaged with the shaft support member 60, and is positioned more to the center than the restriction engagement portion 75. As described above, by providing the protruding portions on both the restricting member 70 and the shaft supporting member 60, when the restricting member 70 is attached to the shaft supporting member 60, the hooked portion can be reduced and the operation can be performed smoothly. .

  When the control member 70 is engaged with the shaft support member 60, the shaft support tip 62 abuts against the belt control surface 73 (in particular, the control flat surface 73b), whereby the control member 70 (belt control surface 73) The movement toward the end side relative to the support tip 62 is restricted. Further, when the restricting member 70 moves to the center side, the restricting engagement portion 75 is caught on the support engaging portion 63, so that the movement of the restricting member 70 is restricted, and the restricting member 70 can be prevented from being detached. In the state in which the shaft support tip 62 is in contact with the belt control surface 73, the support engagement portion 63 is separated from the control engagement portion 75 in the axial direction W. That is, the restriction member 70 is engaged with the shaft support member 60 in a state where a gap is provided in the axial direction W. Therefore, by causing the regulating member 70 to be loosely engaged with the shaft support member 60, it is possible to provide a delay for the regulating member 70 to be inclined, and to securely lock the inclined regulating member 70. Further, since the locking in the axial direction W does not inhibit the movement in the axial direction, the regulating member 70 rotates independently of the shaft supporting member 60 to avoid damage to the fixing belt 53 and the like due to friction. it can.

  As described above, the heating roller 52 is a straight pipe having a uniform diameter, which can be easily thinned, and effectively functions to miniaturize the fixing device 17. In the heating roller 52, which is a straight tube, no difference in diameter is provided in the vicinity of the shaft support tip 62, and there is a concern that the fixing belt 53 may slip into the shaft support member 60. Prevention is more important. Here, the opening of the upper surface of the regulating member 70 is substantially equal to the diameter of the heating roller 52. Therefore, at the center side of the shaft support tip 62, the belt contact surface 74 prevents the fixing belt 53 from invading. A gap is provided between the outer circumferential surface of the heating roller 52 and, particularly, in the vicinity of the shaft support tip 62 among the inner circumferential surfaces of the belt contact surface 74.

  FIG. 7 is an enlarged cross-sectional view of the vicinity of the end of the heating roller in a state in which the fixing belt meanders.

  FIG. 7 shows the fixing belt 53 meandering toward the end (in the direction of the arrow mark A1) with respect to FIG. The end of the meandering fixing belt 53 rides on the belt contact surface 74. Here, as a result of the difference in speed caused by the inclination of the belt contact surface 74, the fixing belt 53 is pushed back to the center side, the movement to the end side is decelerated, and the meandering is suppressed.

  FIG. 8 is a cross-sectional view of an essential part showing the vicinity of the end of the heating roller in a state where the fixing belt further meanders.

  FIG. 8 shows a state in which the fixing belt 53 further meanders toward the end (in the direction of the arrow mark A2) with respect to FIG. In FIG. 7, the end of the fixing belt 53 runs on a part of the belt contact surface 74, but in FIG. 8, the end of the fixing belt 53 is on substantially the entire belt contact surface 74. I am riding on In the following description, for the sake of explanation, the side of the regulating member 70 where the heating roller 52 and the fixing belt 53 are in contact (the lower side in FIG. 8) is referred to as the tension side. The side which is separated (upper side in FIG. 8) may be called the release side.

  In the state shown in FIG. 8, the tension of the fixing belt 53 causes the belt contact surface 74 on the stretching side to be pressed so that the inner circumferential surface approaches the heating roller 52. Since a gap is provided between the belt contact surface 74 and the outer peripheral surface of the heating roller 52, the regulating member 70 is inclined, and the belt regulating surface 73 on the release side is pushed out toward the center (see arrow F). direction). The pushed-out belt regulation surface 73 can make a meandering correction by pushing the fixing belt 53 back to the center side. At this time, the end portion of the fixing belt 53 which is greatly meandered contacts the belt restricting surface 73, but in the restricting inclined surface 73a, since the inclination toward the end is maintained even if the restricting member 70 is inclined, the fixing belt 53 meanders can be corrected.

  In the present embodiment, since the belt contact surface 74 has a uniform and flat inclination, no load is applied to the fixing belt 53 when the fixing belt 53 rides on, and damage can be prevented.

  As described above, by providing the regulation members 70 at both ends of the heating roller 52, the meandering can be suppressed even when the fixing belt 53 meanders to whichever.

Second Embodiment
Next, a mobile unit according to a second embodiment of the present invention will be described with reference to the drawings. In addition, in 2nd Embodiment, since it has the general | schematic structure substantially the same as 1st Embodiment, the same code | symbol is attached | subjected and drawing and description are abbreviate | omitted.

  FIG. 9 is a schematic top view showing a fixing device according to a second embodiment of the present invention.

  The second embodiment differs from the first embodiment in that a restricting member 70 is provided at one end of the heating roller 52. As described above, by providing the restricting member 70 only at one end of the heating roller 52, it is possible to suppress an increase in the number of parts and save space. In this configuration, the fixing belt 53 may be adjusted to meander only to the side of the regulating member 70 by applying a load to one end side or the like.

Third Embodiment
Next, a mobile unit according to a third embodiment of the present invention will be described with reference to the drawings. In the third embodiment, the general structure is substantially the same as that of the first embodiment and the second embodiment, so the same reference numerals are given and the drawings and the description are omitted.

  In the first embodiment, the belt contact surface 74 of the restricting member 70 has a uniform flat inclination. However, the present invention is not limited to this, and may have a curved inclination. That is, in the belt contact surface 74, in the vicinity of the shaft support tip 62, the gap with the outer peripheral surface of the heating roller 52 may be configured to be larger than the center side.

  The embodiment disclosed this time is an example in all points, and it is not a basis for a limited interpretation. Therefore, the technical scope of the present invention is not interpreted only by the above-mentioned embodiment, and is defined based on the statement of a claim. Moreover, all the changes within the meaning and range equivalent to a claim are included.

Reference Signs List 1 image forming apparatus 17 fixing device 51 fixing roller 52 heating roller 53 fixing belt 54 pressure roller 60 shaft support member 61 outer peripheral support portion 62 shaft support tip 63 support engagement portion 70 restricting member 71 base 72 restricting facing portion 73 belt restricting surface 73a Regulated inclined surface 73b Regulated flat surface 74 Belt contact surface 75 Regulated engagement portion

Claims (9)

A fixing device in which a fixing belt is stretched around a heating roller and a fixing roller,
An axial support member supporting an axial end of the heating roller;
And a regulating member engaged with the shaft support member,
The shaft support member is provided with an outer peripheral support portion covering an outer peripheral surface of the heating roller at an axial end of the heating roller.
When the tip of the outer peripheral support portion located on the center side of the heating roller in the axial direction is a shaft support tip,
The restricting member is provided with a belt restricting surface which covers the tip end of the shaft in the axial direction, and a belt contact surface which extends from the belt restricting surface to the center side of the heating roller in the axial direction.
The belt contact surface is inclined so that the diameter decreases in the axial direction toward the center side of the heating roller, and the inner peripheral surface and the outer peripheral surface of the heating roller at the end portion on the tip end of the shaft support And a gap is provided between the fixing device and the fixing device. The fixing device according to claim 1, wherein
The fixing device is characterized in that the restriction member is engaged with the shaft support member in a state where a gap is provided in the axial direction. The fixing device according to claim 2,
The restricting member includes a restricting facing portion facing the outer circumferential support portion in a direction orthogonal to the axial direction,
The regulation opposing portion is provided with a regulation engaging portion that protrudes toward the outer peripheral support portion,
The outer circumferential support portion is provided with a support engagement portion that protrudes toward the restriction facing portion,
The fixing device is characterized in that the supporting and engaging portion is located on the center side of the heating roller in the axial direction with respect to the restricting engaging portion, and is separated from the restricting engaging portion in the axial direction. . A fixing device according to any one of claims 1 to 3, wherein
The fixing device, wherein the restriction member is formed of the same material as the heating roller. A fixing device according to any one of claims 1 to 4, wherein
The fixing device according to claim 1, wherein the heating roller has a cylindrical shape with a uniform diameter in the axial direction. The fixing device according to any one of claims 1 to 5, wherein
A fixing inclined surface which is inclined in a direction toward the end portion side of the heating roller in the axial direction as being away from the heating roller is provided on an outer periphery of the belt restricting surface. A fixing device according to any one of claims 1 to 6, wherein
The fixing device is characterized in that the restriction member is provided at both ends of the heating roller. A fixing device according to any one of claims 1 to 6, wherein
The fixing device is characterized in that the restriction member is provided at one end of the heating roller.   An image forming apparatus comprising the fixing device according to any one of claims 1 to 8.

Images