JP5949039B2 - Fixing device - Google Patents

Description

The present invention relates to fixing equipment.

  For example, Patent Document 1 includes a fixing roller having a built-in heat source and a pressure roller pressed against the fixing roller, and the toner image on the recording medium is fixed to the recording medium by the fixing roller and the pressure roller. And a heat-resistant heat insulating member having a bearing member rotatably supporting the fixing roller, and a heat-resistant heat-insulating member disposed between the inner peripheral surface of the bearing member and the outer peripheral surface of the fixing roller. A fixing device is disclosed in which the member is provided with a restricting means for restricting the axial movement of the fixing roller of the bearing member and the heat-resistant heat insulating member itself.

JP 2005-37825 A

The present invention aims at providing a fixing equipment capable of performing the positional regulation of the heating member with a simple configuration.

According to the first aspect of the present invention, a pressure member that is rotatably held and pressurizes in one direction, and is held rotatably while facing the pressure member, and is pressed in one direction by the pressure member. A cylindrical member whose end is deformed and a heating unit disposed in the cylindrical member, and the toner image transferred to the sheet is applied to the sheet by the pressure of the pressing member and the heat of the heating unit. The heating member to be fixed and the end portion of the cylindrical member disposed so as to rotate together with the heating member are in contact with the end surface of the cylindrical member to be deformed to regulate the position of the cylindrical member in the length direction. A regulating portion that is fixed to the apparatus main body and that is in surface contact with the regulating portion and rotatably holds the regulating portion, and the regulating portion engages with the holding portion. A fixing device having a curved engagement portion.
The invention according to claim 2 further includes a restricting portion that restricts a moving amount of the restricting portion that moves with respect to the holding portion by engaging the engaging portion of the restricting portion with the holding portion. a fixing device according to claim 1, wherein.

According to claim 1, as compared with the case where the present invention is not adopted, the position of the heating member can be regulated with a simple configuration, and the mutual contact state between the regulating part and the holding part is ensured. Is possible.
According to the second aspect, it is possible to restrict the inclination of the restricting portion relative to the holding portion as compared with the case where the present invention is not adopted .

1 is a diagram illustrating a schematic configuration of an image forming apparatus to which an embodiment of the present invention is applied. FIG. 2 is a longitudinal sectional view showing a configuration of a fixing device according to the present embodiment. It is a figure explaining the structure of a heating roll. FIG. 3 is a diagram illustrating a main part of the fixing device according to the first embodiment. FIG. 3 is a diagram illustrating a main part of the fixing device according to the first embodiment. FIG. 6 is a diagram illustrating a main part of a fixing device according to a modification of the first embodiment. It is a figure explaining the fixing sleeve used for the fixing device which concerns on 2nd Embodiment. FIG. 4 is a diagram illustrating a main part of a fixing device according to a second embodiment. FIG. 4 is a diagram illustrating a main part of a fixing device according to a second embodiment. FIG. 4 is a diagram illustrating a main part of a fixing device according to a second embodiment. It is a figure explaining the fixing sleeve used for the fixing device which concerns on 3rd Embodiment. FIG. 10 is a diagram illustrating a main part of a fixing device according to a third embodiment. FIG. 10 is a diagram illustrating a main part of a fixing device according to a modification of the third embodiment.

Embodiments of the present invention will be described below in detail with reference to the accompanying drawings.
FIG. 1 is a diagram showing a schematic configuration of an image forming apparatus 1 to which an embodiment of the present invention is applied.
The image forming apparatus 1 includes an image forming unit 10 that forms an image on a recording medium (hereinafter sometimes referred to as “sheet P” as a representative), and a sheet supply that supplies the sheet to the image forming unit 10. A unit 170 and a stacking unit 177 for stacking sheets on which images are formed by the image forming unit 10. The image forming apparatus 1 also includes a paper transport unit 180 that transports the paper on which an image is formed by the image forming unit 10 and a control unit 190 that controls the operation of each unit described above.

  The image forming unit 10 includes four image forming units 11Y, 11M, 11C, yellow (Y), magenta (M), cyan (C), and black (K) arranged in parallel at substantially constant intervals. 11K. Each image forming unit 11 predetermines an electrostatic latent image formed by laser irradiation by a photosensitive drum 12, a charger 13 for uniformly charging the surface of the photosensitive drum 12, and an optical system unit 20 described later. And a developing device 14 for developing and visualizing the obtained color component toner. The image forming unit 10 is provided with toner cartridges 19Y, 19M, 19C, and 19K for supplying toner of each color to the developing devices 14 of the image forming units 11Y, 11M, 11C, and 11K. An optical system unit 20 for irradiating the photosensitive drum 12 of the image forming units 11Y, 11M, 11C, and 11K with laser light is disposed below the image forming units 11Y, 11M, 11C, and 11K.

  Further, the image forming unit 10 includes an intermediate transfer unit 30 that multiplex-transfers toner images of respective colors formed on the photosensitive drums 12 of the image forming units 11Y, 11M, 11C, and 11K onto the intermediate transfer belt 31, and an intermediate transfer unit. The image forming apparatus includes a secondary transfer roll 41 that transfers a toner image formed on the sheet 30 onto a sheet, and a fixing device 60 that fixes the toner image formed on the sheet by heating and pressing.

  The optical system unit 20 includes, in addition to a semiconductor laser and a modulator (not shown), a polygon mirror 21 that deflects and scans laser light (LB-Y, LB-M, LB-C, LB-K) emitted from the semiconductor laser, A glass window 22 through which laser light passes and a rectangular parallelepiped frame 23 for sealing each component are provided.

  The intermediate transfer unit 30 includes an intermediate transfer belt 31 as an example of an image carrier that is an intermediate transfer member, a drive roll 32 that drives the intermediate transfer belt 31, and a tension that applies a substantially constant tension to the intermediate transfer belt 31. And a roll 33. Further, the intermediate transfer unit 30 has a plurality of (this embodiment) for transferring the toner images formed on the photosensitive drum 12 facing each photoconductor drum 12 and the intermediate transfer belt 31 on the intermediate transfer belt 31. 4) primary transfer rolls 34, and a backup roll 35 provided opposite to the secondary transfer roll 41 with the intermediate transfer belt 31 interposed therebetween.

  The intermediate transfer belt 31 includes a plurality of rotary members such as a drive roll 32, a tension roll 33, a plurality of primary transfer rolls 34, and a backup roll 35. A drive roll that is stretched so as to be longer than the length in a direction substantially orthogonal to the plane including the rotation axis of the roll 34 and is stretched with a substantially constant tension, and is rotationally driven by a drive motor (not shown). 32 circulates at a predetermined speed in the direction of the arrow. As the intermediate transfer belt 31, for example, a belt formed of rubber or resin is used.

Further, the intermediate transfer unit 30 includes a cleaning device 36 that removes residual toner and the like existing on the intermediate transfer belt 31. The cleaning device 36 includes a cleaning brush 36a and a cleaning blade 36b, and removes residual toner, paper dust, and the like from the surface of the intermediate transfer belt 31 after the toner image transfer process is completed.
In this way, the intermediate transfer unit 30 is stretched so that the intermediate transfer belt 31 is elongated in the direction in which the plurality of primary transfer rolls 34 are arranged on the drive roll 32, the tension roll 33, and the like. The intermediate transfer belt 31 has an elongated shape in which a backup roll 35 is disposed at one end portion in the longitudinal direction and a cleaning device 36 is disposed at the other end portion in the longitudinal direction.

The secondary transfer roll 41 forms a secondary transfer portion with the intermediate transfer belt 31 by pressing the backup roll 35 via the intermediate transfer belt 31, and a toner image is formed on the sheet at the secondary transfer portion. Secondary transfer. In order to transfer the toner image formed on the intermediate transfer belt 31 to the sheet, the secondary transfer roll 41 gives a charge opposite to the toner charging polarity to the sheet, and the toner on the intermediate transfer belt 31 by electrostatic force. Transfer the image to the paper. Therefore, a predetermined transfer electric field is generated between the secondary transfer roll 41 and the backup roll 35.
The fixing device 60 applies the image (toner image) on the paper secondarily transferred by the intermediate transfer unit 30 and the secondary transfer roll 41 to the paper using heat and pressure by the heating roll 61 and the endless belt 62. This is a fixing device. The fixing device 60 will be described in detail later.

  The paper supply unit 170 includes a paper storage unit 171 that stores paper on which an image is recorded, a supply roll 172 that picks up the paper from the paper storage unit 171 and supplies the paper to the transport path 174, and the paper supplied from the supply roll 172. And a feed roll 173 that separates and conveys the sheets one by one. In addition, the paper supply unit 170 transports the paper separated by the feed roll 173 one by one toward the secondary transfer position, and the paper transported via the transport path 174 is secondary to the transport path 174. And a resist roll 175 that conveys the transfer position in time.

The paper transport unit 180 transports the paper fed from the fixing device 60 toward the stacking unit 177 while niping the paper, and reverses the paper by a switchback method if necessary, and a reversing roll 181. A reversing conveyance unit 182 for conveying the reversed paper again toward the secondary transfer position. Further, the paper transport unit 180 includes a switching gate 183 that is disposed between the fixing device 60 and the reverse roll 181 and switches the paper traveling direction.
The reverse conveyance unit 182 includes a plurality of conveyance rolls, and again conveys the sheet reversed by the reverse roll 181 toward the secondary transfer position. The switching gate 183 determines the traveling direction of the sheet sent out from the fixing device 60 so as to be guided to the reversing roll 181 or to guide the sheet reversed by the reversing roll 181 to the reversing conveyance unit 182. Switch the paper advance direction.

The image forming apparatus 1 configured as described above operates as follows.
A document image read by an image reading device (not shown) or image data received from a personal computer (not shown) is subjected to predetermined image processing, and the image data subjected to the image processing is yellow (Y). , Magenta (M), cyan (C), and black (K) are converted into color material gradation data of four colors and output to the optical system unit 20.

  The optical system unit 20 emits laser light emitted from a semiconductor laser (not shown) to the polygon mirror 21 via an f-θ lens (not shown) in accordance with the input color material gradation data. . In the polygon mirror 21, the incident laser light is modulated in accordance with gradation data of each color, deflected and scanned, and image forming units 11Y, 11M, 11C, and 11K through an imaging lens (not shown) and a plurality of mirrors. The photosensitive drum 12 is irradiated.

  On the photosensitive drums 12 of the image forming units 11Y, 11M, 11C, and 11K, the surface charged by the charger 13 is subjected to scanning exposure to form an electrostatic latent image. The formed electrostatic latent image is developed as a toner image of each color of yellow (Y), magenta (M), cyan (C), and black (K) in each of the image forming units 11Y, 11M, 11C, and 11K. Is done. The toner images formed on the photosensitive drums 12 of the image forming units 11Y, 11M, 11C, and 11K are multiplex-transferred onto an intermediate transfer belt 31 that is an intermediate transfer member.

  On the other hand, in the paper supply unit 170, the supply roll 172 rotates in accordance with the timing of image formation and picks up the paper stored in the paper storage unit 171, and is separated one by one by the feed roll 173, and then the transport path 174. After that, it is conveyed to the resist roll 175 and temporarily stopped. Thereafter, the registration roll 175 rotates in accordance with the movement timing of the intermediate transfer belt 31 on which the toner image is formed, and is conveyed to the secondary transfer position formed by the backup roll 35 and the secondary transfer roll 41. On the sheet conveyed from the lower side to the upper side at the secondary transfer position, the toner images in which the four colors are multiplexed are sequentially transferred in the sub-scanning direction by using the pressing force and a predetermined electric field. . The sheet on which the toner image of each color is transferred is subjected to a fixing process by heat and pressure by the fixing device 60, and is then stacked on the stacking unit 177 by the sheet transport unit 180 or reversed and secondarily transferred again. Sent toward the location.

Next, the fixing device 60 will be described.
FIG. 2 is a longitudinal sectional view showing the configuration of the fixing device 60 according to the present embodiment.
The fixing device 60 includes a heating roll 61 as an example of a heating member that heats a sheet, and an endless belt (hereinafter referred to as an additional belt) that is an example of a pressing unit that pressurizes the heating roll 61 and constitutes a part of the pressing unit. 62). As another example of the pressing means, a pressing roll having a shaft as an example of a rotating shaft and an elastic body layer (for example, a rubber layer) formed on the outer periphery of the shaft may be used. The fixing device 60 functions as one form of a heating device that heats the paper. In the following description, the endless belt 62 will be described as an example of an opposing member which is an example of the pressing unit and constitutes a part of the pressing unit and is a member facing the heating roll 61. Instead of the endless belt 62, a pressure roll may be used.

First, the heating roll 61 will be described.
The heating roll 61 is a member that rotates with an axis extending in a direction orthogonal to the paper surface in FIG. 1 (a direction from either the front side or the back side toward the other) as a rotation axis, and a thin cylindrical base 611; A heat-resistant elastic layer 612 formed around the base 611 and a release layer 613 formed on the surface of the heat-resistant elastic layer 612 are included. The heating rolls 61 are attached to a fixing device frame 60a (see FIG. 3) that is fixed to or detached from a main body frame (not shown) of the image forming apparatus 1, and are respectively disposed on both end sides in the rotation axis direction. It is supported rotatably with respect to the frame 60a (see FIG. 3) via a bearing member such as a ball bearing. Note that the rotation axis may be an axis having a physical state or a virtual axis having a physical state.

  The base 611 is a thin cylindrical member. The base 611 is a material that is elastically deformed by the contact between the heating roll 61 and the endless belt 62 and is restored by its own rigidity when not in contact with the endless belt 62, and is formed of a material having high thermal conductivity. Has been. Examples of the material exhibiting such characteristics include iron, nickel, nickel steel, stainless steel (SUS (Stainless Used Steel)), nickel-cobalt alloy, copper, gold, nickel-iron alloy, and the like. Since the base 611 has such characteristics, the heating roll 61 is elastically deformed by coming into contact with the endless belt 62 to widen the area of the nip portion N that is a contact region along the paper conveyance direction. Pressure is applied to the sheet in the nip portion N by its own elastic force with the endless belt 62, and when it is not in contact with the endless belt 62, it is restored to a cylindrical shape with its own rigidity. In addition, on the inner surface side (the inner side of the thin cylindrical shape) corresponding to the nip portion N of the base body 611, a member that supports the base body 611 from the inner surface side is not disposed. However, since the base 611 is a material that is elastically deformed by the contact between the heating roll 61 and the endless belt 62 and is restored by its own rigidity when not in contact with the endless belt 62, the base 611 corresponds to the nip portion N of the base 611. Even if the supporting member is not disposed on the inner surface side, it elastically deforms when it comes into contact with the endless belt 62, and when it is not in contact with the endless belt 62, it is restored to a cylindrical shape with its own rigidity. However, there is no problem even if a supporting member is arranged as necessary. The nip portion N is an example of a heating and pressing unit that heats and pressurizes the sheet with the endless belt 62 when the heating roll 61 is pressed from the pressure pad 64 via the endless belt 62.

  The base body 611 according to this embodiment is made of nickel, and has an outer diameter of 25 mm and a thickness of 0.1 mm. The outer diameter is exemplified by a diameter of 25 mm, but is not limited thereto, and may be in a range of 20 mm to 30 mm, and the wall thickness is exemplified by 0.1 mm, but is not limited thereto. It may be in the range of 0.05 mm to 0.2 mm. The cylindrical base body 611 made of nickel and having a thickness of 0.1 mm is formed by any method, and for example, it may be formed by electroforming, deep drawing, or the like.

The heat resistant elastic layer 612 is formed of an elastic body having high heat resistance. Any material can be used as long as it is an elastic body having high heat resistance, and it is particularly preferable to use an elastic body such as rubber or elastomer having a rubber hardness of about 5 ° to 20 ° (JIS-A). . Specifically, silicone rubber, fluorine rubber and the like can be exemplified.
The release layer 613 is formed of a heat resistant resin. Any resin can be used as long as it is a heat-resistant resin. For example, a silicone resin, a fluororesin, or the like can be used. From the viewpoint of releasability and abrasion resistance of the release layer 613 to the toner, Is suitable. As the fluororesin, PFA, PTFE (polytetrafluoroethylene), FEP (tetrafluoroethylene hexafluoropropylene copolymer), or the like can be used. The thickness of the release layer 613 is preferably 5 to 30 μm.

  The fixing device 60 includes a halogen heater 615 that is disposed inside the heating roll 61 and functions as a heat source, and a temperature sensor 616 that detects the temperature of the surface of the heating roll 61. The control unit 190 described above controls lighting of the halogen heater 615 based on the temperature detection value by the temperature sensor 616 so that the surface temperature of the heating roll 61 is maintained at a predetermined fixing temperature (for example, 170 ° C.). Adjust to.

Next, the endless belt 62 will be described.
The endless belt 62 is an endless belt whose original shape is formed in a cylindrical shape having a diameter of 30 mm. The endless belt 62 is composed of a base layer and a release layer (not shown) coated on the surface or both surfaces of the base layer on the heating roll 61 side. It is configured. The base layer is formed of a polymer such as polyimide, polyamide, or polyimideamide, or a metal such as SUS, nickel, or copper, and the thickness is preferably 30 to 200 μm. The release layer coated on the surface of the base layer is formed of a fluororesin such as PFA, PTFE, or FEP, and the thickness is preferably 5 to 100 μm.
Further, the inner peripheral surface of the endless belt 62 has a surface roughness Ra (arithmetic average roughness) set to 0.4 μm or less in order to reduce a sliding resistance with a pressure pad 64 described later. Further, the outer peripheral surface of the endless belt 62 is set to have a surface roughness Ra of 1.2 to 2.0 μm so that the driving force from the heating roll 61 is easily received.

Next, a configuration for supporting the endless belt 62 will be described.
The fixing device 60 includes a pressure pad 64 and an edge guide (not shown) that rotatably support the endless belt 62, and a low friction sheet 621 that reduces the frictional resistance between the inner peripheral surface of the endless belt 62 and the pressure pad 64. And a metal holder 622 for holding the pressure pad 64 and the low friction sheet 621.
The pressure pad 64 is disposed inside the endless belt 62 while being pressed against the heating roll 61 via the endless belt 62, and functions to form a nip portion N between the heating roll 61 and the endless belt 62. To do. The pressure pad 64 includes a pre-nip member 64a for securing a wide nip portion N having a length in the paper conveyance direction (length in the moving direction of the endless belt 62 and the heating roll 61), and peeling for imparting distortion to the heating roll 61. And a nip member 64b. The pre-nip member 64 a is disposed on the inlet side of the nip portion N, and the peeling nip member 64 b is disposed on the outlet side of the nip portion N.

The pre-nip member 64 a is configured by an elastic body such as silicone rubber or fluorine rubber, a leaf spring, or the like, and the surface on the heating roll 61 side is formed in a concave shape that substantially follows the outer peripheral surface of the heating roll 61.
The peeling nip member 64b is formed of a heat-resistant resin such as PPS (polyphenylene sulfide), polyimide, polyester, or polyamide, or a metal such as iron, aluminum, or SUS. As the shape of the peeling nip member 64b, the outer surface shape in the nip portion N is formed into a convex curved surface having a substantially constant radius of curvature.

In the endless belt 62, except for the nip portion N and the vicinity thereof, the inner peripheral surfaces of both side portions in the rotation axis direction are supported by the outer peripheral surface of the belt traveling guide portion 651, and along the outer peripheral surface of the belt traveling guide portion 651. Rotate. Therefore, the belt traveling guide portion 651 is formed of a material having a small coefficient of static friction so that the endless belt 62 can smoothly rotate, and further has low thermal conductivity so that it is difficult to remove heat from the endless belt 62. It is made of material. In addition, the distance between the inner side surfaces of the flange portions arranged at both ends of the holder 622 in the rotation axis direction is substantially matched with the width of the endless belt 62, and the movement of the endless belt 62 in the rotation axis direction (belt walk) is restricted. doing. Thus, the endless belt 62 is set so that the movement in the rotation direction and the rotation axis direction is regulated by the edge guide (not shown).
In the present embodiment, the heating roll 61 is pressed by the pressure pad 64 through the endless belt 62 with a total load of 50 to 250 N (5.1 to 25.5 kgf). With this configuration, the endless belt 62 rotates following the rotation of the heating roll 61.

  The low friction sheet 621 is provided on the surface of the pre-nip member 64a and the peeling nip member 64b that are in contact with the endless belt 62. The low friction sheet 621 is formed of a material having a small friction coefficient and excellent wear resistance and heat resistance in order to reduce the friction resistance (friction resistance) between the inner peripheral surface of the endless belt 62 and the pressure pad 64. ing. Further, minute unevenness is formed on the surface of the low friction sheet 621 on the endless belt 62 side so that the lubricant applied to the inner peripheral surface of the endless belt 62 can enter the sliding portion with the endless belt 62. Yes. The roughness of the unevenness is Ra (arithmetic mean roughness) of 5 to 30 μm. This is not appropriate if the roughness of the unevenness is less than Ra = 5 μm, and it is not appropriate because it is difficult to allow a sufficient lubricant to enter the sliding portion with the endless belt 62. This is based on the fact that the mark is not preferable because it is noticeable as uneven gloss when OHP or coated paper is fixed. Furthermore, the low-friction sheet 621 is formed so as not to be infiltrated into the lubricant (i.e., difficult to pass through) so that the lubricant does not permeate and leak from the back surface. Specifically, a porous resin fiber cloth made of a fluororesin is used as a base layer, and a surface of the pressure pad 64 is wrapped with a PET resin sheet, a sintered PTFE resin sheet, and Teflon (registered trademark) are impregnated. It can be illustrated that it is formed by a glass fiber sheet or the like. The low friction sheet 621 may be configured separately from the pre-nip member 64a and the peeling nip member 64b, or may be configured integrally with the pre-nip member 64a and the peeling nip member 64b.

  The holder 622 holds the pressure pad 64 and the low friction sheet 621, and holds the lubricant application member 623 that extends in the direction of the rotation axis of the heating roll 61 and applies lubricant to the inner peripheral surface of the endless belt 62. To do. The lubricant application member 623 is made of heat-resistant felt, and is impregnated with about 3 g of a lubricant such as amino-modified silicone oil having a viscosity of 300 cs, for example. The lubricant applying member 623 is disposed so as to be in contact with the inner peripheral surface of the endless belt 62, and supplies an appropriate amount of lubricant to the inner peripheral surface of the endless belt 62 by osmotic pressure from the heat resistant felt. The lubricant application member 623 is configured such that the edge portion of the heat-resistant felt is in contact with the inner peripheral surface of the endless belt 62 so that the supply of lubricant from the heat-resistant felt is not excessive. As a result, the lubricant is supplied to the sliding portion between the endless belt 62 and the low friction sheet 621, and the friction resistance between the endless belt 62 and the pressure pad 64 via the low friction sheet 621 is further reduced. 62 is smoothly rotated.

Next, the heating roll 61 of the fixing device 60 will be described.
FIG. 3 is a diagram illustrating the configuration of the heating roll 61.
As shown in FIG. 3, the fixing device 60 includes the frame 60 a, the heating roll 61, and the pressure belt 62 described above. The frame 60a is positioned and attached to the image forming apparatus.
The heating roll 61 is rotatably attached to the frame 60a, and the pressure belt 62 is attached to a support 60b that is movable with respect to the frame 60a. The frame 60a and the support 60b are connected to each other by a compression coil spring 60c. The pressure belt 62 presses (presses) the heating roll 61 by the action of the compression coil spring 60c.

The fixing device 60 includes a drive motor 66 that outputs a driving force for driving the heating roll 61, and a drive transmission unit 67 that transmits the driving force output from the driving motor 66 to the heating roll 61 side.
The drive motor 66 is driven and controlled by the control unit 190 (see FIG. 1). The drive transmission part 67 is attached to the cylindrical member 61a as the base 611 described above. More specifically, the drive transmission part 67 is attached to the drive side end part (left end part of FIG. 3) which is one end part of the cylindrical member 61a.

The fixing device 60 includes a position restriction member 68 attached to each end of the cylindrical member 61 a of the heating roll 61, and a fixing sleeve 69 attached to the frame 60 a and engaged with the position restriction member 68. . The position regulating member 68 is made of, for example, PPS resin, and the fixing sleeve 69 is made of, for example, PPS resin or PPA resin.
The position regulating member 68 and the fixed sleeve 69 are attached to the driving side end (left end in FIG. 3) of the cylindrical member 61a, and the driven side end (right end in FIG. 3) which is the other end of the cylindrical member 61a. Part). The fixed sleeve 69 is fixed to the frame 60a.

More specifically, in the heating roll 61, both end portions of the cylindrical member 61a are held by the frame 60a via the position regulating member 68 and the fixed sleeve 69. The cylindrical member 61a and the position restricting member 68 are both rotatable. That is, when the heating roll 61 is elastically deformed by the pressurization of the pressure belt 62, both can rotate in the same rotational direction and the same rotational speed.
More specifically, at the driving side end (left end in FIG. 3), when the driving force of the driving motor 66 is transmitted to the position restricting member 68 via the drive transmitting portion 67, the cylindrical member 61a is positioned. It rotates in conjunction with the rotation of the restricting member 68 (followed). Further, when the cylindrical member 61a is rotated by the driving force of the drive motor 66 at the driven side end (the right end in FIG. 3), the position regulating member 68 is rotated in conjunction with the rotation of the cylindrical member 61a.
As described above, in the fixing device 60, the cylindrical member 61a of the heating roll 61 and the position regulating member 68 are in a relationship of being rotated together.

  The pressure belt 62 as the endless belt 62 is an example of a pressure member. The heating roll 61 is an example of a heating member, the cylindrical member 61a as the base 611 is an example of a cylindrical member, and the halogen heater 615 is an example of a heating unit. Moreover, the drive transmission part 67 is an example of a restriction part, and the position restriction member 68 is an example of a restriction part.

Next, the fixing device 60 according to the first embodiment will be described.
4 and 5 are diagrams for explaining the main part of the fixing device 60 according to the first embodiment, and the relationship among the cylindrical member 61a of the heating roll 61, the position regulating member 68, and the fixing sleeve 69 is explained. It is a figure to do. 4 shows a case where the cylindrical member 61 a is not pressurized by the pressure belt 62, and FIG. 5 shows a case where the cylindrical member 61 a is pressurized by the pressure belt 62. (A) of each figure is a longitudinal sectional view near the driven side end of the heating roll 61, and (b) of each figure is a transverse sectional view of the heating roll 61 taken along line XX of (a). It is.
As shown in FIG. 4A, the position regulating member 68 is formed with a recess 71 that receives the end of the cylindrical member 61 a of the heating roll 61, and a projection 72 that engages with the fixing sleeve 69. Is formed.

First, the relationship between the heating roll 61 and the position regulating member 68 will be described more specifically.
The recess 71 of the position restricting member 68 has an inner peripheral surface 71a and an inner wall surface 71b corresponding to the shape of the cylindrical member 61a.
More specifically, as shown in FIG. 4A, the inner wall surface 71b of the recess 71 corresponds to the end surface 61d of the cylindrical member 61a and is in contact with the end surface 61d. In other words, the position regulating member 68 receives the end surface 61d of the cylindrical member 61a with the inner wall surface 71b.

  As shown in FIG. 4B, the inner peripheral surface 71a of the concave portion 71 of the position regulating member 68 corresponds to the outer peripheral surface 61c of the cylindrical member 61a. That is, the outer peripheral surface 61c of the heating roll 61 has a circular cross section, and the inner peripheral surface 71a of the position regulating member 68 has a circular cross section. More specifically, the position regulating member 68 is not press-fitted by fitting with the cylindrical member 61a of the heating roll 61, and is formed so as to have a gap (for example, 0.5 mm) as shown in FIG.

  More specifically, if the cylindrical member 61a of the heating roll 61 is not pressurized by the pressure belt 62, the outer peripheral surface 61c of the heating roll 61 is the inner peripheral surface 71a of the position regulating member 68, as shown in FIG. Like, it has a circular shape. On the other hand, when the cylindrical member 61a of the heating roll 61 is pressurized by the pressure belt 62, the cylindrical member 61a is deformed as shown in FIG. That is, when the pressure belt 62 presses the cylindrical member 61 a of the heating roll 61, the cylindrical member 61 a is crushed and tries to swell, thereby filling the gap. And the cylindrical member 61a deform | transforms according to the internal peripheral surface 71a of the position control member 68, and a cross-sectional circular shape changes to a circular shape with a cross section. Since such a deformed shape of the cylindrical member 61a is formed over the entire length in the length direction (thrust direction) D, the cylindrical member 61a has each end, that is, a driving side end (left end in FIG. 3). Further, the driven side end (the right end in FIG. 3) is also deformed.

The cylindrical member 61a deforming in this way elastically receives the pressure applied by the pressure belt 62 without a support member (for example, the pressure pad 64 (see FIG. 2) of the pressure belt 62). For this reason, the cylindrical member 61a is made of a material that can withstand internal stress caused by the pressure of the pressure belt 62 and has elasticity (spring property).
In addition, in this embodiment, the plate thickness is 0.1 mm by using a relatively hard steel material for the cylindrical member 61a. However, when a softer material is used, the plate thickness is further increased.

  In the state shown in FIG. 4, the cylindrical member 61a of the heating roll 61 is not in close contact with the inner peripheral surface 71a of the position regulating member 68, and in the state shown in FIG. 5, the elasticity of the cylindrical member 61a. As a result, the outer peripheral surface 61c is in close contact with the inner peripheral surface 71a. That is, the outer peripheral surface 61c is pressed against the inner peripheral surface 71a of the position restricting member 68 at each end of the cylindrical member 61a by the pressurization of the pressurizing belt 62, whereby the outer peripheral surface 61c is separated from the inner peripheral surface 71a. Close contact with the surface. In other words, the outer peripheral surface 61c of the cylindrical member 61a is not in contact with the inner peripheral surface 71a of the position regulating member 68 at a point (point contact) but in a surface having a certain range (surface contact).

Due to the close contact between the cylindrical member 61a and the position restricting member 68, the frictional force between them increases, and the rotational driving force is reliably transmitted between the cylindrical member 61a and the position restricting member 68. In the present embodiment, the cylindrical member 61a is locked to the position regulating member 68 by such surface contact. When the close contact state between the cylindrical member 61a and the position restricting member 68 is released, the surface contact is lost and the lock is released, whereby the rotational driving force is not sufficiently transmitted.
In order to further increase the frictional force between the cylindrical member 61a and the position restricting member 68, for example, the surface of the inner peripheral surface 71a of the position restricting member 68 may be roughened.
If it adds, it is possible to suppress the shakiness of the heating roll 61 by employ | adopting the structure of this Embodiment.

Next, the relationship between the position regulating member 68 and the fixed sleeve 69 will be described more specifically.
As shown in FIG. 4A or FIG. 5A, the convex portion 72 of the position regulating member 68 has an outer peripheral surface 72 a and an outer end surface 72 b corresponding to the shape of the fixed sleeve 69. The outer peripheral surface 72 a of the convex portion 72 has a smaller diameter than the outer diameter of the cylindrical member 61 a of the heating roll 61.
The fixing sleeve 69 is an example of a holding member, and the outer peripheral surface 72a of the convex portion 72 is an example of an outer peripheral surface. The frame 60a is an example of the apparatus main body.

As described above, the fixed sleeve 69 is attached to the frame 60 a (see FIG. 3) and engages with the position restricting member 68. That is, the fixing sleeve 69 receives the outer peripheral surface 72 a and the outer end surface 72 b of the position regulating member 68.
Note that the force that pressurizes the cylindrical member 61 a by the pressure belt 62 is transmitted to the fixed sleeve 69 via the position regulating member 68.

More specifically, the fixing sleeve 69 is in contact with the outer end surface 72b of the position restricting member 68, thereby determining the position of the position restricting member 68 with respect to the frame 60a. As described above, the end surface 61 d of the cylindrical member 61 a is abutted against the inner wall surface 71 b of the position regulating member 68. Therefore, the cylindrical member 61a of the heating roll 61 is positioned with respect to the length direction D (also shown in FIG. 3) with respect to the frame 60a (see FIG. 3) by the position regulating member 68 and the fixing sleeve 69.
Therefore, for positioning the cylindrical member 61a, it is not necessary to form a notch (not shown) for a retaining ring, for example, in the cylindrical member 61a having a thin plate thickness, and further, a difficult notch processing step. Can be omitted, and there is no risk of a decrease in strength due to the notch. In this case, since the retaining ring is on the fixed side, the moving side may be worn, but in this embodiment, there is no such fear.

Further, as described above, the fixing sleeve 69 is fixed to the frame 60a (see FIG. 3), while the position regulating member 68 is pressurized by the pressure belt 62, It rotates with the cylindrical member 61a. That is, it slides on the fixed sleeve 69 by the outer peripheral surface 72 a and the outer end surface 72 b of the convex portion 72 in the position regulating member 68. Thus, the outer peripheral surface 72a of the position restricting member 68 becomes a bearing surface of the fixed sleeve 69, and the fixed sleeve 69 is a sliding member and has a function as a so-called resin bearing.
More specifically, the convex portion 72 of the position regulating member 68 has a stepped shape and is formed with a small diameter. For this reason, the outer peripheral surface 72a of the position restricting member 68, which is a bearing surface, has a small diameter, and therefore the driving torque for rotating the position restricting member 68 is low, and the fixing sleeve 69 can be downsized. become.
Moreover, in this Embodiment, it becomes possible to shorten the length dimension in the length direction of the heating roll 61. FIG.

Here, the modification about 1st Embodiment is demonstrated.
FIG. 6 is a diagram for explaining a main part of the fixing device 60 according to a modification of the first embodiment, and is a cross-sectional view of the heating roll 61. 6 (a) corresponds to FIG. 4 (b) showing a case where the cylindrical member 61a is not pressurized by the pressure belt 62, and FIG. 6 (b) is a cylinder. This corresponds to (b) of FIG. 5 showing a case where the shaped member 61 a is pressurized by the pressure belt 62.
In the modification shown in FIG. 6, a plurality of ribs 75 are formed on the inner peripheral surface 71 a that defines a part of the recess 71 of the position regulating member 68. And at the time of an assembly, as shown to (a) of FIG. 6, it press-fits into the recessed part 71 of the position control member 68 in the state which deform | transformed the edge part of the cylindrical member 61a (diameter press-fit). Thereby, the frictional force between the cylindrical member 61a and the position restricting member 68 is further increased.
This modified example can be applied to any one end of the cylindrical member 61a, for example, the driven side end (the right end in FIG. 3) of the cylindrical member 61a. When applied to the left end portion), the same positional relationship is obtained by assembling the ribs 75 of the position regulating member 68 at both ends.

Next, the fixing device 60 according to the second embodiment will be described. Since the second embodiment has the same configuration / function as the first embodiment, the same reference numerals are used for the common configuration, and the description and illustration of the common configuration / function are performed. May be omitted.
7A and 7B are diagrams illustrating a fixing sleeve 69 used in the fixing device 60 according to the second embodiment. FIG. 7A is a front view and a plan view of the fixing sleeve 69, and FIG. It is a longitudinal cross-sectional view by the line YY of (a), (c) is a perspective view of the fixing sleeve 69.
As shown in FIGS. 7A and 7C, the fixing sleeve 69 is a member formed in a semicircular arc shape in a front view, and a member formed in a plate shape in a plan view. . The fixed sleeve 69 has an outer edge 81 formed at a position farthest from the center position of the arc. As shown in FIG. 7C, the outer edge portion 81 extends in an arc shape. Further, the longitudinal sectional view of the fixing sleeve 69 taken along a line intersecting the line YY at the center position of the arc has the same shape at any position.

More specifically, as shown in FIG. 7B, in particular, the outer peripheral portion 81 of the fixing sleeve 69 has a convex curved surface portion swelled in a convex shape in one direction in a longitudinal sectional view, and a circular arc from the convex curved surface portion 82. A flange portion 83 extending in the direction of the center position is formed.
In addition, although the fixing sleeve 69 of this Embodiment is a semicircle (1/2 circumference) shape, it is also considered to employ | adopt the 1/4 circumference shape which can halve material cost.

8, 9, and 10 are diagrams for explaining a main part of the fixing device 60 according to the second embodiment. FIG. 8A is a driving side end portion of the heating roll 61 (FIG. 3). FIG. 5B is a longitudinal sectional view in the vicinity of the left end portion of FIG. 5B, and FIG. FIG. 8 shows a case where the heating roll 61 is not inclined with respect to the fixed sleeve 69, and FIG. 9 is a case where the heated heating roll 61 is inclined with respect to the fixed sleeve 69 during operation of the fixing device 60. FIG. 10 shows a case where the heating roll 61 is further tilted with respect to the fixed sleeve 69 as compared with FIG.
As described in the first embodiment, the cylindrical member 61a of the heating roll 61 changes from a circular cross section to an elliptical cross section when pressed by the pressure belt 62 (see FIG. 3) ( 4 and FIG. 5), the surface of the driving gear 91 is in close contact with an inner peripheral surface of an extending portion 91e described later.

  First, the structure of the drive transmission part 67 arrange | positioned at the drive side edge part (left edge part of FIG. 3) of the heating roll in this Embodiment is demonstrated. A drive transmission portion 67 shown in FIG. 8A is inserted into a drive gear 91 having a gear to which a drive force from a drive motor 66 (see FIG. 3) is input, and a cylindrical member 61 a of the heating roll 61. A torsion coil spring-like drive spring 92 and a lid member 93 that engages with the drive gear 91 and receives the end face 61d (see FIG. 5) of the cylindrical member 61a are provided.

The drive gear 91 includes an extending portion 91e extending in the length direction of the cylindrical member 61a, and the extending portion 91e holds the driving side end portion (left end portion in FIG. 3) of the cylindrical member 61a. In other words, the elastic layer and the surface release layer 61e described above are formed in the middle portion of the cylindrical member 61a.
The lid member 93 is accommodated in the drive gear 91, and the heating roller 61 is positioned in the length direction when the end surface 61d of the cylindrical member 61a abuts.

More specifically, the drive gear 91 includes a concave curved surface portion 91a that is recessed into a concave shape corresponding to the convex curved surface portion 82 of the fixed sleeve 69, as shown in FIG. The drive gear 91 includes an engaging portion 91 b that can engage with the flange portion 83 of the fixed sleeve 69 and a wall portion 91 d that positions the lid member 93 accommodated therein.
In the case shown in FIG. 8, the concave curved surface portion 91 a of the drive gear 91 is in surface contact with the convex curved surface portion 82 of the fixed sleeve 69, and the engaging portion 91 b of the drive gear 91 is in contact with the flange portion 83 of the fixed sleeve 69. It is in a state.

Here, the drive spring 92 is accommodated in the drive gear 91 in a state where one end is hooked on the drive gear 91. The inner diameter of the coil of the drive spring 92 is larger than the outer diameter of the cylindrical member 61a.
If no driving force is input to the drive gear 91, the drive spring 92 in the heating roll 61 has a gap between the outer peripheral surface 61c of the cylindrical member 61a. When a driving force is input to the drive gear 91, the drive spring 92 having one end hooked on the drive gear 91 has a reduced coil inner diameter, and extends over substantially the entire circumference of the outer peripheral surface 61c of the cylindrical member 61a. In close contact. Thereby, the driving force of the drive gear 91 is transmitted to the cylindrical member 61a, and the heating roll 61 rotates.
When the input of the driving force to the driving gear 91 is interrupted, the driving spring 92 has an enlarged coil inner diameter and a gap is formed between the outer peripheral surface 61c of the cylindrical member 61a. That is, the drive transmission part 67 of this Embodiment rotates the cylindrical member 61a with the drive spring 92, and employ | adopts a spring clutch structure.

As the heating roll 61 rotates, the cylindrical member 61a of the heating roll 61 may tilt and fall as shown in FIG. As the cylindrical member 61a is inclined, the drive gear 91 is also inclined. On the other hand, the fixing sleeve 69 fixedly attached to the frame 60a (see FIG. 3) does not fall down. Therefore, the engaging portion 91 b of the drive gear 91 is separated from the flange portion 83 of the fixed sleeve 69 in a state where the concave curved surface portion 91 a of the drive gear 91 is in surface contact with the convex curved surface portion 82 of the fixed sleeve 69. That is, the cylindrical member 61 a and the drive gear 91 move (displace) with respect to the fixed sleeve 69.
When the cylindrical member 61a is further inclined, the engaging portion 91b of the drive gear 91 is further away from the flange portion 83 of the fixed sleeve 69 as shown in FIG. Even in such a case, the close contact state between the concave curved surface portion 91 a of the drive gear 91 and the convex curved surface portion 82 of the fixed sleeve 69 can be maintained.
As described above, with the rotation of the heating roll 61, after the cylindrical member 61a is inclined in the order shown in FIG. 8, the state shown in FIG. 9, and the state shown in FIG. 10, the state shown in FIG. The behavior in which the cylindrical member 61a returns in the order shown is repeated.

  In the present embodiment, the fixed sleeve 69 has a convex curved surface portion 82 that is a convex portion, and the drive gear 91 that constitutes a part of the drive transmission portion 67 has a concave portion (concave curved surface portion 91a). A configuration example in which the unevenness is reversed, that is, a configuration example in which the fixed sleeve 69 has a concave portion and the drive transmission portion 67 has a convex portion is also conceivable.

Next, the fixing device 60 according to the third embodiment will be described. The third embodiment is different from the second embodiment in the shape of the fixing sleeve 69, and the other configurations and functions are the same as those in the second embodiment. The same reference numerals are used for the configuration, and the description and illustration may be omitted.
FIG. 11 is a diagram illustrating a fixing sleeve 69 used in the fixing device 60 according to the third embodiment, and corresponds to FIG. 7 in the second embodiment. 11A is a front view, a plan view, and a bottom view of the fixing sleeve 69, FIG. 11B is a longitudinal sectional view taken along line YY of FIG. 11A, and FIG. 11C is a fixing sleeve. 69 is a perspective view of FIG.
As shown in FIGS. 7A and 7C, the outer edge portion 81 of the fixing sleeve 69 includes a convex curved surface portion 82 and a flange portion 83, and in addition to the convex curved surface portion 82 in the longitudinal sectional view, Comprises a stopper 84 located in the opposite direction.
This stopper portion 84 is not provided in the second embodiment (see FIG. 7). More specifically, the convex curved surface portion 82 is located between the flange portion 83 and the stopper portion 84 in the longitudinal sectional view. The convex curved surface portion 82 and the stopper portion 84 are formed along the outer peripheral surface of the outer edge portion 81.

FIG. 12 is a diagram illustrating a main part of the fixing device 60 according to the third embodiment. 12A to 12C are views for explaining the inclination of the cylindrical member 61a accompanying the rotation of the heating roll 61, and correspond to (b) in each of FIGS. 8, 9, and 10. FIG. FIG.
The drive gear 91 in the present embodiment includes an engaging portion 91 c that can be engaged with the stopper portion 84 of the fixed sleeve 69.

As the heating roll 61 rotates, the cylindrical member 61a of the heating roll 61 tilts and falls as shown in order in FIGS. In the states of FIGS. 12A and 12B, the engaging portion 91c of the drive gear 91 is not in contact with the stopper portion 84 of the fixed sleeve 69 and is separated.
More specifically, when the cylindrical member 61a is greatly inclined, as shown in FIG. 12C, the concave curved surface portion 91a of the drive gear 91 is in surface contact with the convex curved surface portion 82 of the fixed sleeve 69. The engaging portion 91 c of the drive gear 91 contacts the stopper portion 84 of the fixed sleeve 69. In this state, the cylindrical member 61a is restricted from further tilting.
In the present embodiment, a fixed sleeve 69 that can be opposed even when the cylindrical member 61a is tilted with rotation is employed. In the present embodiment, the fall regulation is performed so that the cylindrical member 61a is hard to fall.
The convex curved surface portion 82 of the fixed sleeve 69 is an example of a holding portion, and the concave curved surface portion 91a of the drive gear 91 is an example of an engaging portion.
The stopper portion 84 is an example of a limiting portion.

Here, a modification of the third embodiment will be described.
FIG. 13 is a diagram for explaining a main part of a fixing device 60 according to a modification of the third embodiment, and is a longitudinal sectional view in the vicinity of the driving side end portion (left end portion in FIG. 3) of the heating roll 61. .
As illustrated in FIG. 13, the drive transmission unit 67 according to the modification does not include a drive spring 92 (see, for example, FIG. 8). That is, the driving force of the drive motor 66 (see FIG. 3) is deformed at the end of the cylindrical member 61a by the pressure of the pressure belt 62 as in the case of the first embodiment (see FIG. 5). As the cylindrical member 61 a is deformed, the end of the cylindrical member 61 a comes into surface contact with the inner peripheral surface of the drive gear 91. As a result, the driving force is directly transmitted from the driving gear 91 to the cylindrical member 61a.

  Moreover, as shown in FIG. 13, the drive transmission part 67 which concerns on a modification is not provided with the cover member 93 (for example, refer FIG. 8). That is, the drive gear 91 includes a receiving portion 91f that receives the end surface 61d of the cylindrical member 61a. Thereby, the number of components of the drive transmission unit 67 can be reduced.

  In addition, the fixed sleeve 69 in the second embodiment and the fixed sleeve 69 in the third embodiment are provided on the driving side end (left end in FIG. 3) and the driven side end (right end in FIG. 3) of the cylindrical member 61a. A configuration example in which any one of the fixed sleeves 69 is disposed is conceivable. Further, the fixing sleeve 69 according to the second embodiment is disposed on either the driving side end (left end in FIG. 3) or the driven side end (right end in FIG. 3) of the cylindrical member 61a. On the other hand, a configuration example in which the fixing sleeve 69 in the third embodiment is disposed is also conceivable.

  Moreover, although 1st Embodiment thru | or 3rd Embodiment was demonstrated, it is also considered that the structure of 2nd Embodiment or 3rd Embodiment is applied to 1st Embodiment. . For example, the configuration in which the drive side end portion (left end portion in FIG. 3) of the cylindrical member 61a described in the second embodiment, the drive transmission portion 67, and the fixed sleeve 69 are engaged with each other is described in the first embodiment. This is a case where the driven side end portion (the right end portion in FIG. 3) of the cylindrical member 61a, the position regulating member 68, and the fixed sleeve 69 are applied to each other.

  As described above, in the first to third embodiments, the position restriction in the length direction D of the cylindrical member 61a of the heating roll 61 that rotates under the pressure applied by the pressure belt 62 is controlled with the cylindrical member 61a. This is realized with a simple configuration of the accompanying position regulating member 68 or the drive transmission portion 67.

DESCRIPTION OF SYMBOLS 1 ... Image forming apparatus, 60 ... Fixing device, 60a ... Frame, 61 ... Heating roll, 61a ... Cylindrical member, 615 ... Halogen heater, 61d ... End face, 62 ... Pressure belt, 67 ... Drive transmission part, 68 ... Position Restricting member 69 ... fixed sleeve 72a ... outer peripheral surface 82 ... convex curved surface portion 83 ... flange portion 84 ... stopper portion 91 ... drive gear 91a ... concave surface portion 91f ... receiving portion 93 ... lid member

Claims (2)

A pressure member that is rotatably held and pressurizes in one direction;
A cylindrical member that is rotatably held against the pressure member and whose end is deformed by one-way pressure by the pressure member, and a heating unit disposed in the cylindrical member are provided. A heating member that fixes the toner image transferred to the paper to the paper with the pressure of the pressure member and the heat of the heating unit;
A regulating portion that is disposed at the end of the tubular member so as to rotate together with the heating member and regulates the position of the tubular member in the length direction in contact with the end surface of the tubular member that is deformed;
A curved-shaped holding portion fixed to the apparatus main body and in surface contact with the restriction portion to hold the restriction portion rotatably;
Including
The fixing device according to claim 1, wherein the restricting portion includes a curved engagement portion that engages with the holding portion. The restriction part which restrict | limits the movement amount of the said control part which the said engaging part of the said control part engages with the said holding part and moves with respect to the said holding part is characterized by the above-mentioned. Fixing device .

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