JP2020030440A - Image heating device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent damage to a rotating body and to have a safe and long life by suppressing tilt of a rotating body regulating member and realizing stable contact with the rotating body without hindering smooth pressurization and pressure release operation. Image heating is provided. SOLUTION: A gap (A, B, Of C and D), the gap (A, C) between the frame and the regulation surface (10a, 10c) on the side approaching the frame when the rotating body regulation member tilts during pressurization by the elastic member (50L, 50R) It should be smaller than the gap (B, D) between the regulation surface (10b, 10d) on the side away from the frame and the frame. [Selection diagram] Fig. 1

Description

  The present invention relates to an image heating device suitable for use as a fixing device mounted on an image forming apparatus such as a copier, a printer, a facsimile, and a multifunction peripheral having a plurality of these functions.

  2. Description of the Related Art As a fixing device mounted on an image forming apparatus such as an electrophotographic system, a film system including a flexible sleeve (hereinafter referred to as a rotating body) as a fixing film (fixing belt) moving while being in contact with a heating body (heater). Is known. Since this fixing device has good heat transfer efficiency, there is an advantage that the time from the start of energization of the heating element (heater) to the temperature at which fixing can be performed is short, and the time until the first image is output is short. There is. In addition, there is an advantage that power consumption during standby for waiting for a print command is small, and it has been introduced in many recent image forming apparatuses.

  In a film-type fixing device, a rotating body including a heating body is supported by a rotating body regulating member (fixing flange) and a heating body supporting member (heater holder). The rotating body regulating member is engaged so as to sandwich the fixing frame as the apparatus main body, and performs positioning of the pressure roller in the roller axis direction (thrust direction). These are pressed toward the pressing roller by an elastic member (a pressing spring) and a pressing sheet metal.

  Heat and pressure are reduced by nipping and transporting a recording material (sheet: hereinafter, referred to as paper or paper) carrying a toner image in a fixing nip portion between the rotating body and the pressure roller configured as described above. The applied toner is fixed on the paper. The elastic member and the pressure sheet metal are disposed outside the fixing frame in the roller axial direction with respect to the installation space.

  On the other hand, in order to easily remove the paper from the fixing nip portion when a paper jam (jam) occurs during paper passing, the rotating body is separated from the pressure roller against the pressing force of the elastic member. A pressure release mechanism is provided. The rotating body restricting member that supports the rotating body is configured to be movable in the pressing direction with respect to the fixing frame. The rotating body restricting member presses while moving in the direction of the pressure roller when pressurized by the elastic member, and moves in the direction opposite to the pressure roller when pressure is released by the pressure release mechanism, thereby fixing. The pressure at the nip is reduced.

  For this reason, an appropriate gap is provided between the engaging portion between the rotating member regulating member and the fixing frame so that the rotating member regulating member can move smoothly with respect to the fixing frame. The position of the rotating body in the roller axis direction is regulated by the regulating surface of the rotating body regulating member. When the rotating body approaches the roller axis direction, the end of the rotating body abuts on the regulating surface, so that the rotating body is prevented from rotating. Prevents misalignment.

  However, since there is a possibility that the rotor will be damaged if a strong local stress is applied to the end thereof, for example, a configuration that prevents local stress concentration by making the regulating surface of the rotor regulating member a curved surface is proposed. (Patent Document 1).

JP 2006-293225 A

  However, in a configuration in which the center line of the elastic member is disposed outside the fixing frame in the roller axis direction, the rotating body restricting member may be inclined within the range of the gap when the pressure is applied. Therefore, since the regulating surface of the rotating body regulating member is also inclined, it may locally contact the end face of the rotating body, which may lead to breakage.

  From the above, there is a need for an apparatus that suppresses the inclination of the rotating body regulating surface with respect to the fixing frame and achieves stable contact between the rotating body regulating surface and the end surface of the rotating body. On the other hand, there is a demand for a stable pressure release configuration that does not hinder a smooth operation during pressurization and pressure release, and a device that balances these two is desired.

  In view of the above problems, the present invention suppresses the inclination of the rotating body regulating surface and realizes stable contact with the rotating body without hindering smooth pressurizing and depressurizing operations. And to provide a long-life image heating apparatus.

  A typical configuration of the image heating apparatus according to the present invention for achieving the above object is an image heating apparatus that heats a recording material carrying a toner image by nipping and conveying the recording material at a nip portion, and a rotating body; A heating body that heats the rotating body, an opposing body that forms the nip portion together with the rotating body, a frame, and a longitudinal end of the rotating body that come into contact with the end surface to restrict the longitudinal movement of the rotating body. A rotating body restricting member, which is disposed so as to sandwich the frame and movably disposed in a direction intersecting with the axial direction of the opposing body in a direction approaching the opposing body and in a direction opposite thereto. An elastic member that is disposed outside the frame in the axial direction of the opposed body and presses the rotating body regulating member to press the rotating body against the opposed body; and pressing of the rotating body regulating member by the elastic member. Cancel A release mechanism, wherein a gap between the frame and the plurality of regulating surfaces that sandwich the frame provided on the rotating body regulating member, when the rotating body regulating member is tilted when pressurized by the elastic member. The gap between the regulating surface on the side approaching the frame and the frame is smaller than the gap between the regulating surface on the side away from the frame and the frame.

  ADVANTAGE OF THE INVENTION According to this invention, the inclination of the rotating body regulating surface with respect to a frame in a rotating body regulating member is suppressed, without obstructing smooth pressurizing and pressure releasing operations, and the local contact between the rotating body regulating surface and the rotating body is reduced. Can be prevented. Thus, it is possible to provide a long-life image heating apparatus that prevents damage to the rotating body.

Configuration explanatory view of a main part of the fixing device according to the first embodiment. Configuration explanatory view of a main part of a fixing device according to a second embodiment. Configuration explanatory view of a main part of a fixing device according to a third embodiment. Schematic configuration diagram of an example of an image forming apparatus External perspective view of an example of a fixing device FIG. 5 is a schematic cross-sectional right side view taken along line (6)-(6). FIG. 2 is an exploded perspective view of the fixing device, in which (a) is one end side (left side) of the apparatus, and (b) is the other end side (right side). Exploded perspective view of the film unit Configuration illustration of flange (A) is a right side view of the fixing device in a pressure state, and (b) is a right side view of the fixing device in a pressure release state. Illustration of inclination of flange

<< Example 1 >>
[Image forming apparatus]
FIG. 4 is a schematic diagram showing a schematic configuration of an example of the image forming apparatus 100 in which the image heating device according to the present invention is mounted as a fixing device (fixing device) 70. The image forming apparatus 100 is a monochrome printer using an electrophotographic process. Image information is input to a control unit A from an external device B such as a host computer, and the control unit A executes a predetermined image formation control sequence.

  An image forming unit 101 that forms a toner image on a recording material (hereinafter, referred to as paper or paper) S is a drum-type electrophotographic photosensitive member (hereinafter, referred to as a drum) 102 that is driven to rotate clockwise as indicated by an arrow. Having. Around the drum 102, a charging roller 103, a laser scanner unit 104, a developing device 105, and a transfer roller 106 are arranged in this order along the drum rotation direction. The above-described image forming operation (electrophotographic process) of the image forming unit 101 is well-known, and thus detailed description is omitted.

  The sheets S stacked on the sheet cassette 107 or the feed tray (manual tray) 108 are fed one by one by the rotation of the feed rollers 109 or 110. Then, the sheet S is introduced at a predetermined control timing into a transfer nip portion 113 formed by the drum 102 and the transfer roller 106 by a transport path 111 having a pair of registration rollers 112 and receives the transfer of the toner image on the drum 102 side. .

  The sheet S that has passed through the transfer nip 113 is sent to the fixing device 70 along the transport path 114, and undergoes a heat-pressure fixing process of the toner image. The sheet S that has exited the fixing device 70 passes through a transport path 115 and is discharged to a discharge tray 117 as an image formed product by a pair of discharge rollers 116.

[Fixing device]
In the fixing device 70 of the embodiment, the front is the entrance side of the sheet S, and the back is the exit side. The left and right are the left (one end side) or the right (the other end side) when the apparatus 70 is viewed from the front. Up and down means above or below in the direction of gravity. The upstream side and the downstream side are the upstream side and the downstream side in the sheet transport direction (recording material transport direction). In addition, the generatrix direction of the fixing film, the axial direction of the pressure roller, or a direction parallel thereto is defined as a longitudinal direction, and a direction orthogonal thereto is defined as a lateral direction.

  The fixing device 70 is a film (belt) heating type image heating device (OMF: on-demand fixing device) capable of shortening a startup time and reducing power consumption. 5 is an external perspective view of the fixing device 70, and FIG. 6 is a schematic right side cross-sectional view taken along line (6)-(6) in FIG.

  The fixing device 70 is roughly divided into a film unit (belt unit) 73, an elastic pressing roller 71 as an opposing body (pressing member), and a fixing frame (housing: apparatus main body) 20 containing these. Have. 7A and 7B are exploded perspective views of the fixing device 70. FIG. 7A illustrates one end (left side) of the apparatus, and FIG. 7B illustrates the other end side (right side).

(1) Film unit (belt unit) 73
The film unit 73 is a fixing film (a flexible sleeve, an endless belt, and a fixing belt: hereinafter, referred to as a film), which is a hollow (endless, endless belt, or tubular) first rotating body having flexibility. 72. Inside the film 72, a heater (heating body) 30, a heater holder (heating body supporting member: hereinafter, referred to as a holder) 40 for holding the heating and guiding the rotation of the film, and a stay 45 for holding the holder 40 are provided in an internal assembly. It is arranged as. FIG. 8 is a schematic exploded perspective view of the film unit 73.

  The heater 30, the holder 40, and the stay 45 are members whose length is longer than the width (length) of the film 72, and one end (left side) and the other end (right side) are respectively separated from both ends of the film 72. It protrudes in the direction. Reference numeral 40a denotes an outwardly projecting portion of the holder 40, and reference numeral 45a denotes an outwardly projecting portion of the stay 45. Fixing flanges (rotary member regulating members: hereinafter, referred to as flanges) 10L and 10R at one end and the other end are fitted to the outwardly protruding portions 45a at one end and the other end of the stay 45, respectively. I have. That is, the flanges 10L and 10R are arranged at both ends in the longitudinal direction of the film 72.

  The flexible film 72 is a heat-resistant heat-resistant member having a cylindrical shape due to its own elasticity in a free state. For example, a three-layer composite layer consisting of a base layer made of a heat-resistant resin material or a thin metal, an elastic layer made of silicone rubber or the like, and a surface layer made of fluorine resin or the like is arranged in order from the inside to the outside.

  As the heater 30, a ceramic heater is generally used. The heater 30 has a heat-resistant heater substrate (ceramic substrate) made of aluminum nitride, alumina, or the like. On the front side of the heater substrate, a resistor pattern as a heating resistor (resistance heating element) that generates heat by energization is formed along the longitudinal direction of the heater substrate by, for example, printing. Further, the surface of the resistor pattern is covered with a glass layer as a protective layer. The inner surface of the film 72 slides in close contact with the heater surface. A thermistor TH as a temperature detecting member for detecting the temperature of the heater 30 is provided on the back side of the heater substrate.

  The holder 40 is a member formed of a heat-resistant resin, supports the heater 30, and also serves as a rotation guide of the film 72. A groove is formed along the length of the lower surface of the holder 40, and the heater 30 is fitted into and supported by the groove with its front side facing outward. As a material of the holder 40, a heat-resistant resin such as a liquid crystal polymer, a phenol resin, PPS, and PEEK is used. The stay 45 is a rigid member made of a metal such as iron, and is a member that presses the holder 40 over its entire length.

  The flanges 10 (LR) arranged at both ends in the longitudinal direction of the film 72 are left-right symmetrical heat-resistant resin molded products. As the material of the flange 10 having excellent heat resistance, relatively low thermal conductivity, and excellent slipperiness, for example, a resin containing glass fiber such as PPS, liquid crystal polymer, PET, PA, or the like is used. In the following description, “flange 10L” is a left (one end) flange, “flange 10R” is a right (other end) flange, and “flange 10” or “flange 10 (LR)” is both left and right. Flange.

  FIGS. 9A, 9B, and 9C are views of the flange 10 as viewed from the inner surface, the side surface, and the top surface, respectively. (D) is a longitudinal sectional view of (c). The flange 10 includes a flange seat 10A having a rotating body regulating surface 10r, a rotating body guide 10B, a pressure receiving section 10C, a fitting section 10D, and a fitting vertical groove 10E.

  The rotating body guide portion 10B is provided on the side of the rotating body regulating surface 10r of the flange seat portion 10A. The pressure receiving portion 10C is provided on the side opposite to the side of the rotating body regulating surface 10r of the flange seat portion 10A. The fitting portion 10D extends over three members: a rotating body guide portion 10B, a flange seat portion 10A, and a pressure receiving portion 10C. The fitting vertical groove portion 10E is provided on both sides of the meeting portion when the flange is viewed from the top at the meeting portion between the flange seat portion 10A and the pressure receiving portion 10C.

  The rotating body regulating surface 10r is a surface facing the end surface 72a of the longitudinal end of the film 72, and serves to regulate the movement of the film 72 when the film 72 moves in the longitudinal direction, and the film 72 is positioned at a predetermined position in the longitudinal direction. To stay. That is, the rotating body regulating surface 10r regulates the movement of the film 72 in the longitudinal direction by coming into contact with the end face 72a of the longitudinal end of the film 72.

  The rotator guide 10B guides the rotation of the film 72 by supporting the inner peripheral surface of the longitudinal end of the film 72 from the inside. That is, the rotating body guide portion 10B serves to draw a desired rotation locus on the film 72 by regulating the longitudinal end of the film 72 from the inside.

  The fitting portion 10D is a portion fitted to the outwardly protruding portion 45a of the stay 45. The pressure receiving portion 10C is in direct contact with the outwardly protruding portion 45a when fitted to the outwardly protruding portion 45a of the stay 45, and plays a role of pushing down the stay 45 by a pressing mechanism described later.

  The fitting vertical groove portion 10E is an engagement portion with the side plates 20L and 20R of the fixing frame 20. The flanges L and 10R are arranged so as to sandwich the side plates 20L and 20R, that is, the frame in the fitting vertical grooves 10E, and to approach the pressure roller 71 in a direction intersecting the axial direction of the pressure roller 71 and the opposite direction ( Distant direction). This will be described later.

(2) Pressure roller 71
The pressure roller 71 as a second rotating body (opposite body) is a driving rotating body that forms a nip portion N between the film 72 and the heater 30 and that drives the film 72 to rotate. . The pressure roller 71 is an elastic roller formed of an elastic layer formed by foaming heat-resistant rubber such as silicone rubber or fluorine rubber or silicone rubber on the outer peripheral side of a metal core such as SUS, SUM, or Al. A release layer such as PFA, PTFE, or FEP may be formed on the elastic layer.

  The pressure roller 71 is rotatably supported by bearing a shaft portion at one end and the other end between side plates 20L and 20R at one end and the other end of the frame 20 via a bearing member 23, respectively. The pressure roller 71 is driven to rotate at a predetermined peripheral speed in the direction of arrow R71 in FIG. 6 by transmitting the driving force of the driving source M1 controlled by the control unit A via a driving transmission mechanism (not shown). Is done.

  The film unit 73 is disposed between the side plates 20L and 20R, with the heater 30 facing downward, arranged above the pressure roller 71 and substantially parallel to the pressure roller 71. The flanges 10L and 10R of the film unit 73 are engaged with the fitting vertical grooves 10E while sandwiching the vertical edges 24a of the vertical guide slits 24 and 24 provided in the side plates 20L and 20R. In this engaged state, the flange seat portion 10A of the flange 10L is located inside the side plate 20L, and the pressure receiving portion 10C is located outside the side plate 20L. The flange seat portion 10A of the flange 10R is located inside the side plate 20R, and the pressure receiving portion 10C is located outside the side plate 20R.

  Thus, the flanges 10L and 10R are held so as to be slidable in the vertical direction with respect to the side plates 20L and 20R, respectively. That is, the film unit 73 has a degree of freedom in which the film unit 73 can be moved between the side plates 20L and 20R along the vertical edges 24a of the slits 24 and 24 toward and away from the pressure roller 71.

(3) Pressing mechanism The pressure receiving portions 10C of the flanges 10L and 10R are pressed by a pressing mechanism having pressing springs (elastic members) 50L and 50R and pressing levers (pressing metal plates) 51L and 51R, respectively. Receive pressure. The pressure levers 51L and 51R are disposed above the pressure receiving portion 10C outside the side plates 20L and 20R, respectively, and the leading end 51a is inserted into and engaged with the hole 21a on the top plate 21 side of the frame 20. ing. 51c is the engaging portion. The pressing levers 51L and 51R can swing up and down around the engaging portion 51c.

  The pressure springs 50L and 50R are contracted (compressed) between the pressure levers 51L and 51R and the spring receiving portions 21b on one end and the other end of the top plate 21, respectively. The pressure springs 50L and 50R are coil-shaped compression springs in this example. Depending on the device configuration, a tension spring or another pressing mechanism may be used.

When the pressure levers 51L and 51R are in the free state, the pressure receiving portions 10C of the flanges 10L and 10R are pressed downward via the pressure levers 51L and 51R due to the contraction reaction force of the pressure springs 50L and 50R, respectively, and thus are predetermined. Of the same pressure. FIG. 10A is a right side view of the fixing device 70 in the pressurized state. The left side surface of the fixing device 70 is symmetrical with the right side surface. Z indicates the pressing direction. The center line 50c of the pressure spring 50R (50L) is the side plate 20R.
(20L).

  Since the flanges 10L and 10R are fitted to the outwardly protruding portions 45a and 45a at one end and the other end of the stay 45, respectively, the stay 45 is also fitted to the flange 10L in the pressurized state of FIG. A predetermined equivalent pressing force is acting downward through the 10R.

  As a result, the holder 40 having the heater 30 and the pressure roller 71 are pressed against each other with a predetermined pressing force across the film 72 against the elasticity of the elastic layer of the pressure roller 71. In the fixing device 70 of this example, the heater 30 and a part of the holder 40 function as a sliding member (backup member) that comes into contact with the inner surface of the film 72. Therefore, as shown in FIG. 6, a nip portion N having a predetermined width is formed between the film 72 and the pressure roller 71 with respect to the sheet conveying direction (recording material conveying direction) a.

  The levers 51L and 51R are respectively extended to the opposite sides of the engagement portions 51c with the pressure receiving portions 10C of the flanges 10L and 10R as the center. 51b is an extension lever portion. A pressure release mechanism for releasing the pressing of the flanges 10L and 10R by the pressing springs 50L and 50R below the extension lever portions 51b of the pressing levers 51L and 51R is provided on the outside of the side plates 20L and 20R. Release cams 60L and 60R are provided. The pressure release cam 60L is not shown. The cams 60L and 60R are eccentric cams having the same shape and fixed to one end and the other end of the rotation center shaft 60c rotatably supported between the side plates 20L and 20R.

  The cams 60 </ b> L and 60 </ b> R are intermittently controlled by half a rotation when the driving force of the driving source M <b> 2 controlled by the control unit A is transmitted via a driving transmission mechanism (not shown). When the cams 60L and 60R are controlled to the postures of rotation at which the small diameter portions are directed upward as shown in FIG. 10A, the cams 60L and 60R are attached to the extension lever portions 51b of the pressure levers 51L and 51R. Become non-contact. Therefore, the pressure levers 51L and 51R are in a free state, and the fixing device 70 is in a pressure state in which a nip portion N having a predetermined width is formed between the film 72 and the pressure roller 71.

  Further, the cams 60L and 60R are controlled to the postures at which the large-diameter portions are turned upward as shown in FIG. 10 (b), so that the cams 60L and 60R are extended levers of the pressure levers 51L and 51R. It contacts the part 51b. Further, the cams 60L and 60R push the pressure levers 51L and 51R upward against the compression reaction force of the pressure springs 50L and 50R, respectively, around the engagement portion 51c between the distal end portion 51a and the insertion hole portion 21a. lift. Thus, the pressing of the flanges 10L and 10R against the pressure receiving portion 10C by the pressing levers 51L and 51R is released. That is, the formation of the nip N is released or the pressing force of the nip N is reduced.

  As described above, the fixing device 70 is configured to be able to switch between a pressurized state (FIG. 10A) and a pressure released state (FIG. 10B). By setting the pressure release state during non-image formation, plastic deformation of the elastic layer of the pressure roller 71 can be prevented. Further, when a paper jam (jam) occurs during paper passing, the paper can be easily removed from the nip N by switching from the pressurized state to the pressure released state.

(4) Fixing Operation The control unit A starts the image forming operation sequence control of the image forming apparatus 100 based on the image forming start signal. The fixing device 70 is switched from the pressure release state (FIG. 10B) to the pressurized state (FIG. 10A), and the pressure roller 71 is driven to rotate. Due to the rotation of the pressure roller 71, a rotational force acts on the film 72 by a frictional force with the pressure roller 71 in the nip portion N. As a result, the film 72 rotates in the direction of arrow R72 (FIG. 6) while the inner surface of the film 72 slides in the nip portion N in close contact with the surface of the heater 30 and a part of the outer surface of the holder 40. , And driven by the peripheral speed.

  On the other hand, the heater 30 receives power supply from a power supply unit (not shown) controlled by the control unit A via a power supply path (not shown) and generates heat rapidly. The temperature of the heater 30 is detected by a thermistor TH disposed in contact with the back surface of the heater, and the detected temperature information is input to the control unit A. The control unit A appropriately controls the current flowing from the power supply unit to the heater 30 in accordance with the input detected temperature information, thereby raising the temperature of the heater 30 to a predetermined temperature and controlling the temperature so that the temperature is maintained. I do.

  As described above, the pressure roller 71 is driven to rotate, and the film 72 is driven to rotate accordingly, and the temperature of the heater 30 is raised to a predetermined temperature. The paper S carrying the deposited toner image T is introduced into the nip N. The sheet S is introduced into the nip portion N such that the carrying surface of the toner image T faces the film 72, and is nipped and conveyed. As a result, the unfixed toner image T on the paper is heated and pressurized and fixed as a fixed image. The sheet S having passed through the nip portion N is separated from the surface of the film 72 by a curvature and is discharged and conveyed from the fixing device 70.

(5) Attaching Configuration of Flanges to Side Plates As described above, the flanges 10L and 10R of the film unit 73 are attached to the side plates 20L and 20R so as to be movable in the pressing direction. At the time of pressing (at the time of pressing), the pressing stay 45 is pressed while moving in the direction of the pressing roller 71. That is, the nip portion N is set to a predetermined pressurized state. When the pressure is released by the pressure release mechanism 60, the pressure in the nip N is reduced by moving in a direction opposite to the pressure roller 71.

  Therefore, an appropriate gap is provided in the engaging portion between the flanges 10L, 10R and the side plates 20L, 20R so that the flanges 10L, 10R can move smoothly with respect to the side plates 20L, 20R. That is, an appropriate gap is provided in the engaging portion between the fitting vertical groove portion 10E of the flanges 10L and 10R and the vertical edge portion 24a of the side plate slit 24. Hereinafter, the flange 10R on the other end will be described as a representative, but the same applies to the flange 10L on the one end.

  FIG. 11B is an enlarged view of a portion surrounded by a dashed line in FIG. A plurality of regulating surfaces (convex portions) 10m, 10n, 10o, and 10p sandwiching the side plate 20R (24a) in the fitting vertical groove portion 10E of the flange 10R and the inner surface and the outer surface of the vertical edge portion 24a of the slit 24 of the side plate 20R. Have gaps M, N, O, and P. M = N and O = P are set as follows.

  The position of the film 72 in the roller axis direction (thrust direction) is regulated by the regulation surface 10r of the flange seat portion 10A of the flange 10R. That is, when the film 72 shifts in the roller axis direction, the end surface 72a of the longitudinal end of the film 72 abuts on the regulating surface 10r, thereby preventing the film 72 from being displaced.

However, in a configuration in which the center line 50c of the pressing spring 50R is disposed outside the side plate 20R in the roller axial direction, the flange 10R is pressed within the range of the gaps M, N, O, and P in FIG. As shown in (c), it may be inclined in the R direction. Therefore, since the regulating surface 10r of the flange 10R is also inclined, it may locally contact the end surface 72a of the film 72, which may lead to breakage of the film end surface (film end). FIG. 11C is an exaggerated view of a state in which the flange 10R is inclined in the R direction.

  Therefore, as described in the section of the problem, there is a need for a fixing device that suppresses the inclination of the regulating surface 10r of the flange 10 with respect to the fixing frame 20 and achieves stable contact between the regulating surface 10r and the end surface 72a of the film 72. I have. On the other hand, there is a demand for a stable pressure release configuration that does not hinder a smooth operation during pressurization and pressure release, and a fixing device that balances the two is desired.

  For this purpose, the first embodiment employs a configuration for preventing the flange 10 from tilting as shown in FIG. FIG. 1A is a schematic configuration diagram in the roller axial direction (thrust direction) when the film 72 is pressed against the pressing roller 71. (B) is an enlarged view of a portion surrounded by a dashed line in (a), and shows an engagement portion between the flange 10R and the side plate 20R, that is, a fitting vertical groove portion 10E of the flange 10R and a vertical edge portion 24a of the side plate slit 24. It is explanatory drawing showing the clearance gap of the engaging part.

  Reference numerals 10a, 10b, 10c, and 10d denote regulating surfaces (convex portions) of the flange 10R with respect to the side plate 20R in the roller axis direction. The regulating surfaces 10a and 10b regulate the inner side in the roller axis direction, that is, the inner surface of the vertical edge 24a of the slit 24 of the side plate 20R. The regulating surfaces 10c and 10d regulate the outer side in the roller axis direction, that is, the outer surface of the vertical edge 24a of the slit 24 of the side plate 20R. A, B, C, and D are gaps between the regulating surfaces 10a, 10b, 10c, and 10d and the inner surface and the outer surface of the vertical edge 24a of the side plate slit 24, respectively.

  In the fixing device 70 of the first embodiment, the gaps between the regulating surfaces 10a, 10b, 10c, and 10d of the flange 10R and the engaging portions of the side plate 20R in the roller axis direction are A <B and C <D. More specifically, the protrusion amount (projection amount) of the regulating surface 10a is set to be larger than the protrusion amount of the restriction surface 10b, and the protrusion amount of the restriction surface 10c is set to be larger than the protrusion amount of the restriction surface 10bd. The protrusion amounts of the regulating surfaces 10a and 10c are the same, and the protrusion amounts of the regulating surfaces 10b and 10d are the same.

  With the configuration of the regulating surfaces 10a, 10b, 10c, and 10d, for example, A = 0.05 mm, B = 0.10 mm, C = 0.05 mm, and D = 0.10 mm, and the dimensions of the parts are A <B. , C <D are set and managed. That is, the gaps A and C when the flange 10R is inclined by being pressed by the pressing spring 50R and the pressing lever 51R in the Z direction are set smaller than the gaps B and D on the opposite side.

  The relationship between the regulation surface and the gap in the first embodiment is summarized as follows. There are gaps A, B, C, D between the plurality of regulating surfaces 10a, 10b, 10c, 10d that sandwich the side plate 20R provided on the flange 10R and the side plate 20R. The gaps A and C between the regulating surfaces 10a and 10c on the side approaching the side plate 20R and the side plates 20L and 20R when the flange 10R inclines at the time of pressurization by the pressure mechanism are the regulating surfaces 10b and 10d on the side moving away from the side plate 20R. It is smaller than the gaps B and D between the side plates 20R.

  Among the plurality of restricting surfaces 10a, 10b, 10c, and 10d, the restricting surfaces 10a and 10c on the side approaching the side plate 20R when the flange 10R is tilted during pressurization by the pressurizing mechanism are defined as first restrictive surfaces. Further, the regulation surfaces 10b and 10d on the side away from the side plate 20R are defined as second regulation surfaces. In this case, the first regulating surfaces 10a and 10c have a larger protrusion amount extending toward the flange 10R than the second regulating surfaces 10b and 10d.

  Thus, the inclination of the flange 10R with respect to the side plate 20R when pressed by the pressure spring 50R can be minimized. That is, the inclination of the regulating surface 10r of the flange 10R can be suppressed. Therefore, local contact between the regulating surface 10r and the film 72 can be prevented, and damage to the end of the film 72 can be prevented.

  Further, by setting A <D and C <B, and by clearly separating the surface that positively abuts and the surface where the gap is provided, the operation of the flange 10R when the fixing device 70 switches between the pressed state and the released state. Can be configured so as not to hinder. The above configuration is the same for the flange 10L and the side plate 20L.

  Therefore, it is possible to achieve both prevention of breakage of the end portion of the film 72 and smooth operation at the time of pressurizing / releasing pressure.

<< Example 2 >>
FIG. 2 is an explanatory diagram of a mounting configuration of a flange to a side plate in the second embodiment. (A) is a schematic configuration diagram in the roller axis direction (thrust direction) when the film 72 is pressed against the pressing roller 71. (B) is an enlarged view of a portion surrounded by a dashed line in (a), and shows an engagement portion between the flange 10R and the side plate 20R, that is, a fitting vertical groove portion 10E of the flange 10R and a vertical edge portion 24a of the side plate slit 24. It is explanatory drawing showing the clearance gap of the engaging part. The basic configuration is the same as in FIG. 1 of the first embodiment, and a detailed description is omitted. Hereinafter, the flange 10R on the other end will be described as a representative, but the same applies to the flange 10L on the one end.

  The second embodiment is different from the first embodiment in that the protrusion 20e is formed on the side of the side plate 20R in order to reduce the gap between the fitting vertical groove 10E of the flange 10R and the vertical edge 24a of the side plate slit 24. 20 g is provided. That is, while the amount of protrusion (projection) of the regulating surfaces (projections) 10e and 10f of the flange 10R is equal to the amount of protrusion of 10g and 10h, the regulating surface (projection) of the side plate 20R is located at a position facing the regulating surfaces 10e and 10g. Parts) 20e and 20g are provided. Thereby, the gaps between the regulating surfaces (projections) 10e, 10f, 10g, and 10h of the flange 10R and the engaging portions of the side plate 20R and the regulating surfaces 20e and 20g in the roller axis direction are set to E <F and G <H.

  More specifically, for example, E = 0.05 mm, F = 0.10 mm, G = 0.05 mm, and H = 0.10 mm, and dimensions are set such that the dimensions of the parts satisfy E <F and G <H. The tolerance is set and managed. That is, the gaps E and G when the flange 10R is inclined by being pressed by the pressing spring 50R and the pressing lever 51R in the Z direction are set smaller than the gaps F and H on the opposite side.

  The relationship between the regulation surface and the gap in the second embodiment is summarized as follows. The side plate 20R, which is a fixing frame, has regulating surfaces 20e, 20f, 20g, and 20h at positions facing a plurality of regulating surfaces 10e, 10f, 10g, and 10h provided on the flange 10R.

  Among the regulating surfaces provided on the side plate 20L, the regulating surfaces 20e and 20g on the side closer to the regulating surfaces 10e and 10g of the flange 10R when the flange 10R is tilted during pressurization by the pressurizing mechanism are defined as first regulating surfaces. The restriction surfaces 20f and 20h on the side where the restriction surfaces 10f and 10h of the flange 10R are away from each other are defined as second restriction surfaces. In this case, the first regulating surfaces 20e and 20g have a larger protrusion amount extending toward the flange 10R than the second regulating surfaces 20f and 20h.

  Thus, the inclination of the flange 10R with respect to the side plate 20R when pressed by the pressure spring 50R can be minimized. That is, the inclination of the regulating surface 10r of the flange 10R can be suppressed. Therefore, local contact between the regulating surface 10r and the film 72 can be prevented, and damage to the end of the film 72 can be prevented.

  Further, by setting E <H and G <F, and by clearly separating the surface to be positively abutted and the surface to provide a gap, the operation of the flange 10R when switching between the pressurized state and the pressure released state is not hindered. It can be. The same applies to the flange 10L and the side plate 20L.

  Therefore, it is possible to achieve both prevention of breakage of the end portion of the film 72 and smooth operation at the time of pressurizing / releasing pressure.

<< Example 3 >>
FIG. 3 is an explanatory diagram of a mounting configuration of a flange to a side plate in the third embodiment. Hereinafter, the flange 10R on the other end will be described as a representative, but the same applies to the flange 10L on the one end. The basic configuration is the same as FIG. 9 and FIGS. 1 and 2 of the first and second embodiments, and a detailed description thereof will be omitted.

  FIG. 3A is a schematic configuration diagram in the roller axial direction (thrust direction) before the film 72 is pressed against the pressing roller 71. (B) is an enlarged view of a portion surrounded by a chain line in (a). (C) is a schematic configuration diagram in the roller axis direction (thrust direction) when the film 72 is pressed against the pressing roller 71.

  In the third embodiment, when the flange 10R is pressed by the pressing spring 50R and tilts in the gap between the engagement vertical groove 10E and the engaging portion between the vertical edge 24a of the side plate slit 24, the regulating surface 10r It is configured to be substantially parallel to 20R.

  That is, in the fixing device 70 of the third embodiment, the amount of protrusion of the regulating surfaces (projections) 10i and 10j in the fitting vertical groove 10E of the flange 10R is the same as the amount of protrusion of 10k and 10l. Then, before the pressure is applied by the pressing spring 50R, the gaps I, J, K, and L between the regulating surfaces (convex portions) 10i, 10j, 10k, and 10l and the side plate 20R are defined as I = J and K = L. To secure a gap between the flange 10R and the side plate 20R. At this time, in the fixing device 70 of the third embodiment, the regulating surface 10r of the flange 10R is slightly inclined downward with respect to the side plate 20R as shown in FIG.

  Here, when the flange 10R is pressed by the pressing spring 50R, the flange 10R rotates in the R direction within the range of the gaps I, J, K, and L with the side plate 20R as shown in FIG. Then, the regulating surfaces (convex portions) 10i and 10k are tilted to a position where they come into contact with the side plate 20R. At this time, the regulation surface 10r is substantially parallel to the side plate 20R.

  The above configuration in the third embodiment is summarized as follows. The restricting surfaces 10i, 10j, 10k, and 10l that hold the side plate 20R, which is a fixing frame, provided on the flange 10R are inclined when contacting the side plate 20R when pressed by the pressing mechanism. At this time, the rotating body regulating surface 10r for regulating the longitudinal movement of the film 72 on the flange 10R is substantially parallel to the side plate 20R.

  Thereby, the inclination of the regulating surface 10r can be suppressed in the pressurized state by the pressurizing spring 50R of the pressurizing mechanism. Therefore, local contact between the regulating surface 10r and the film 72 can be prevented, and damage to the end of the film 72 can be prevented.

  In addition, by securing the gaps I, J, K, and L between the regulating surfaces (convex portions) 10i, 10j, 10k, and 10l and the side plate 20R, the operation of the flange 10R when switching between the pressurized state and the pressure released state is achieved. A configuration that does not interfere can be adopted. The same applies to the flange 10L and the side plate 20L.

  Therefore, it is possible to achieve both prevention of breakage of the end portion of the film 72 and smooth operation at the time of pressurizing / releasing pressure.

  As in the above-described three embodiments, the inclination of the regulating surface 10r of the flange 10 with respect to the side plate of the fixing frame 20 when pressed by the pressing spring 50 can be minimized. Local contact can be prevented. Also, by clearly separating the surface on which the flange 10 and the side plate of the fixing frame 20 are positively abutted and the surface on which the gap is provided, the operation of the flange 10 when switching between the pressurized state and the pressure released state is prevented. It can be configured without. Therefore, it is possible to achieve both prevention of breakage of the end portion of the film 72 and smooth operation at the time of pressurizing / releasing pressure.

<< other matters >>
(1) In the above three embodiments, the number of regulating surfaces (projections) in the fitting vertical groove portion 10E of the flange 10 is two each with the side plate of the fixing frame 20 interposed therebetween. However, the present invention is not limited to this, and as described above, one side can be constituted by only one as long as the gap relationship is satisfied in consideration of the inclination of the flange 10, or three or more regulating surfaces are provided. Is also good.

  (2) In the fixing device 70 of the embodiment, the flanges 10L and 10R are provided at one end and the other end of the film 72, respectively. However, if the apparatus is configured such that the moving direction of the film 72 is exclusively one direction, the flange 10 may be one of the moving sides of the film 72.

  (3) As the fixing device 70 in the embodiment, a film-type fixing device as described above is mentioned as an example. However, the present invention is not limited to this, and can be applied to, for example, a fixing device of a type in which a halogen heater is provided inside a fixing roller (heat roller) to heat the fixing roller.

  (4) The sliding member (backup member) inside the film 72 may be a member other than the heater 30.

  (5) The means for heating the first rotating body film 72 is not limited to the heater 30 of the embodiment. Appropriate heating configurations such as an internal heating configuration, an external heating configuration, a contact heating configuration, and a non-contact heating configuration using other heating means such as a halogen heater and an electromagnetic induction coil can be employed.

  (6) The film 72 may be used as a driving rotating body, and the pressure roller 71 may be driven to rotate by the rotation of the film 72.

  (7) In the embodiments, the fixing device that heats and fixes an unfixed toner image formed on a recording material is described as an example of the image heating device, but is not limited thereto. The present invention can also be applied to a device (glossiness improving device) for increasing the gloss (glossiness) of an image by reheating a toner image fixed or assumed on a recording material.

  (8) The image forming apparatus is not limited to the one that forms a monocolor image as in the embodiment. An image forming apparatus for forming a color image may be used. Further, the image forming apparatus can be implemented in various applications such as a copier, a facsimile, and a multifunction peripheral having a plurality of these functions, in addition to necessary devices, equipment, and a housing structure.

  70 image heating device (fixing device), S. recording material, T. toner image, 72 rotating body (fixing film), 72a film end face, 71 facing body (pressure roller), N ・ ・ Nip, 20L ・ 20R ・ ・ Frame (side plate), 10L ・ 10R ・ ・ Rotating body regulating member (flange), 50L ・ 50R ・ ・ Elastic member, 60L ・ 60R ・ ・ Press release mechanism, 10a ・ 10b ・10c ・ 10d ・ ・ Regulatory surface, A ・ B ・ C ・ D ・ ・ Gap

The present invention is prevented in consideration of the above problems, without interfering with the smooth pressurization and pressure releasing operation, by realizing a stable contact between the regulation surface and the rotating body (film), the breakage of the rotary body And a long-life image heating apparatus.

A typical configuration of the image heating apparatus according to the present invention for achieving the above object includes a cylindrical film and a roller which is in contact with an outer peripheral surface of the film and forms a nip portion between the film and the film. And a regulating member arranged to face an end face of the film in a longitudinal direction of the film, and a regulating member for regulating movement of the film in the longitudinal direction, and a frame holding the regulating member and the roller, A pressure spring that applies pressure to the roller via the regulating member by urging the regulating member so that the nip portion is formed; and A regulating surface for receiving the end surface of the film when the film moves, a force receiving portion for receiving a biasing force of the pressing spring, and a groove for mounting the regulating member on the frame. In an image heating apparatus that heats the image while nipping and conveying the recording material on which the image is formed in the nip portion, the regulating member mounted on the frame may be moved in a direction in which the recording material is conveyed in the nip portion. When viewed, the regulation surface is located on the side of the first surface of the frame, and the force receiving portion is located on the side of the second surface of the frame opposite to the first surface. A first protruding portion that protrudes toward the first surface at a position in the groove portion of the regulating member that faces the first surface of the frame; A second protruding portion that protrudes toward the first surface and is located downstream of the first protruding portion in the biasing direction of the pressure spring. The position of the regulating member in the groove portion and the position of the frame A third protruding portion protruding toward the second surface is provided at a position facing the second surface, and the restricting member mounted on the frame is moved to the recording material in the nip portion. When viewed in the conveyance direction, the regulating surface and the groove are non-parallel, and the pressure when the image on the recording material is heated at the nip is applied to the regulating member by the pressure spring. The regulating surface is substantially parallel to the frame, the first protrusion is in contact with the first surface of the frame, the second protrusion is separated from the frame, The third protrusion is in contact with the second surface of the frame .

According to the present invention, without interfering with smooth pressurization and pressure releasing operation, it is possible to prevent local contact with the regulatory surface and the rotating member (film). Thus, it is possible to provide a long-life image heating apparatus that prevents damage to the rotating body.

The rotating body guide portion 10B is provided on the side of the rotating body regulating surface 10r of the flange seat portion 10A. The pressure receiving portion 10C (force receiving portion) is provided on the side opposite to the rotating body regulating surface 10r of the flange seat portion 10A. The fitting portion 10D extends over three members: a rotating body guide portion 10B, a flange seat portion 10A, and a pressure receiving portion 10C. The fitting vertical groove portion 10E is provided on both sides of the meeting portion when the flange is viewed from the top at the meeting portion between the flange seat portion 10A and the pressure receiving portion 10C.

Reference numerals 10a, 10b, 10c, and 10d denote regulating surfaces (convex portions) of the flange 10R with respect to the side plate 20R in the roller axis direction. The regulating surfaces 10a and 10b regulate the inner side in the roller axis direction, that is, the inner surface (first surface) of the vertical edge portion 24a of the slit 24 of the side plate 20R. The regulating surfaces 10c and 10d regulate the outer side in the roller axis direction, that is, the outer surface (second surface) of the vertical edge portion 24a of the slit 24 of the side plate 20R. A, B, C, and D are gaps between the regulating surfaces 10a, 10b, 10c, and 10d and the inner surface and the outer surface of the vertical edge 24a of the side plate slit 24, respectively.

That is, in the fixing device 70 of the third embodiment, the protrusion amounts of the regulating surfaces (projections) 10i (first projections) and 10j (second projections) in the fitting vertical grooves 10E of the flanges 10R, 10k ( The projection amount of the third projection) and 10l (fourth projection) are the same. Then, before the pressure is applied by the pressing spring 50R, the gaps I, J, K, and L between the regulating surfaces (convex portions) 10i, 10j, 10k, and 10l and the side plate 20R are defined as I = J and K = L. To secure a gap between the flange 10R and the side plate 20R. At this time, in the fixing device 70 of the third embodiment, the regulating surface 10r of the flange 10R is slightly inclined downward with respect to the side plate 20R as shown in FIG.

Claims (6)

An image heating apparatus that heats a recording material carrying a toner image while nipping and conveying the recording material at a nip portion,
A rotating body,
A heating body for heating the rotating body,
An opposing body that forms the nip together with the rotating body;
Frame and
A rotating body restricting member that restricts longitudinal movement of the rotating body by being in contact with an end face of a longitudinal end of the rotating body, a direction intersecting the axial direction of the opposed body so as to sandwich the frame. A rotating body regulating member movably disposed in a direction approaching the opposing body and in a direction opposite thereto,
An elastic member disposed outside the frame in the axial direction of the opposed body, and pressing the rotating body regulating member to press the rotating body against the opposed body;
And a pressure release mechanism for releasing the pressing of the rotating body regulating member by the elastic member,
Of the gaps between the frame and the plurality of regulating surfaces that sandwich the frame provided on the rotating body regulating member, regulating the side approaching the frame when the rotating body regulating member is inclined when pressurized by the elastic member. An image heating apparatus, wherein a gap between a surface and the frame is smaller than a gap between the regulating surface on a side moving away from the frame and the frame.   Of the plurality of restricting surfaces, when the rotating member restricting member is tilted at the time of pressurization by the elastic member, a restricting surface closer to the frame extends toward the frame than a restricting surface that moves away from the frame. The image heating apparatus according to claim 1, wherein the amount is large.   The frame has a restricting surface at a position facing the plurality of restricting surfaces provided on the rotating body restricting member, and among the restricting surfaces provided on the frame, the rotation is performed when the elastic member presses. When the body regulating member is tilted, the regulating surface of the rotating body regulating member on the side closer to the regulating surface extends toward the rotating body regulating member than the regulating surface of the rotating body regulating member on the side away from the regulating surface. The image heating apparatus according to claim 1, wherein the amount is large. An image heating apparatus that heats a recording material carrying a toner image while nipping and conveying the recording material at a nip portion,
A rotating body,
A heating body for heating the rotating body,
An opposing body that forms the nip together with the rotating body;
Frame and
A rotating body restricting member that restricts longitudinal movement of the rotating body by being in contact with an end face of a longitudinal end of the rotating body, a direction intersecting the axial direction of the opposed body so as to sandwich the frame. A rotating body regulating member movably disposed in a direction approaching the opposing body and in a direction opposite thereto,
An elastic member disposed outside the frame in the axial direction of the opposed body, and pressing the rotating body regulating member to press the rotating body against the opposed body;
And a pressure release mechanism for releasing the pressing of the rotating body regulating member by the elastic member,
When the regulating surface provided on the rotating body regulating member for holding the frame inclines when pressed by the elastic member and comes into contact with the frame, the rotation regulating the longitudinal movement of the rotating body in the rotating body regulating member. An image heating device, wherein a body regulating surface is substantially parallel to the frame. The rotating body is an endless belt,
The opposed body is a pressure roller,
The image heating apparatus according to claim 1, wherein the heating body is a heating resistor provided on a substrate and in contact with an inner surface of the endless belt. The rotating body is a heat roller,
The opposed body is a pressure roller,
The image heating apparatus according to claim 1, wherein the heating body is a halogen heater disposed inside the heat roller.

Images