JP2019056900A - Fixation device - Google Patents

Abstract

To provide a fixation device that can suppress breakage of the edge of a cylindrical heating rotational body by reducing the approaching force of the rotational body.SOLUTION: A regulation part 13b of a regulation member 13 provided on both sides of the film 8 in a longer direction has at least two opposed surfaces 13a11 and 13a12 for regulating the rotational path of the film by contacting with the inner surface 8b of the film in an upstream position of the regulation part in the direction of conveyance of a recording material in the longer direction of the film. The opposed surface 13a11, which is closer to the regulation part than the opposed surface 13a12, has a larger arc extending to the inside of the film than the opposed surface 13a12.SELECTED DRAWING: Figure 4

Description

  The present invention relates to a fixing device mounted on an image forming apparatus such as an electrophotographic copying machine or an electrophotographic printer.

  As a fixing device mounted on an electrophotographic copying machine or printer, a film heating type device is known. This type of fixing device has a rotatable cylindrical film, a plate-shaped heater that contacts the inner peripheral surface of the film, and a pressure roller that forms a nip portion together with the heater via the film. Yes. The recording material carrying the unfixed toner image is heated while being conveyed by the nip portion, whereby the toner image is fixed on the recording material.

  In a film heating type fixing device, in the longitudinal direction of the film perpendicular to the recording material conveyance direction, the deviation of the parallelism of the pressure roller and the film and the pressure distribution of the nip part due to the component tolerance and assembly tolerance in the production of the device May be biased. In that case, a force for moving the film in the film longitudinal direction (hereinafter referred to as a film shifting force) acts, and the film shifts in the film longitudinal direction.

  Therefore, the fixing device disclosed in Patent Document 1 is provided with a restricting member that faces the film end, and when the film is displaced, the end of the film is received by the restricting portion of the restricting member. The restricting portion is provided with a surface whose inner diameter gradually decreases toward the outer side in the film longitudinal direction, and the damage of the film end portion is suppressed by the surface.

Japanese Patent No. 3814542

  In a film heating type fixing device, it is required to reduce the shifting force of the film and suppress the breakage of the film end.

  SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a fixing device that can reduce the shifting force of a cylindrical film and suppress the breakage of the film end.

In order to achieve the above object, a fixing device according to the present invention includes:
A fixing device for fixing an image formed on a recording material to the recording material,
The frame of the device,
Components that fit into the frame of the device;
A cylindrical film that rotates while in contact with the recording material;
A support part disposed in a position facing the end in the longitudinal direction of the film in the internal space of the film, the support part provided in the component;
A roller that contacts the outer peripheral surface of the film and forms a nip portion for nipping and conveying the recording material between the film and the film,
The support portion includes a first facing surface facing an inner surface of an end portion in the longitudinal direction of the film, and a second facing surface facing an inner surface in the longitudinal direction of the film with respect to the first facing surface. And both the first facing surface and the second facing surface are surfaces that fit with the frame of the component and are opposed to the flat portion of the frame of the component. The angle between the surface and the surface is almost vertical,
When the component is viewed along the longitudinal direction of the film, the contour of the first facing surface is larger than the contour of the second facing surface.

  According to the present invention, it is possible to provide a fixing device that can reduce the shifting force of the cylindrical film and suppress the breakage of the film end.

1 is a perspective view illustrating a schematic configuration of a fixing device according to Embodiment 1. FIG. Sectional drawing which shows schematic structure of the fixing apparatus which concerns on Example 1. FIG. 1 is a perspective view showing the right flange of FIG. FIG. 1 is a perspective view of the right flange of FIG. 1 and the right end of the film supported by the support portion of the flange as viewed from the upstream side in the recording material conveyance direction. The figure which shows the positional relationship of the support part of the right flange of FIG. 1, and the film by which a rotation track is controlled by the support part. The figure which shows the relation between the distance between the control part of the right and left flange and the length of the film The figure which shows a state when a film has shifted | deviated to the film longitudinal direction The figure for demonstrating the 1st opposing surface of a flange, and a 2nd opposing surface The figure which shows the right and left flange and film which provided the 1st opposing surface and the 2nd opposing surface in the recording material conveyance direction upstream The figure which shows the right and left flange and film which provided the 1st opposing surface and the 2nd opposing surface in the recording material conveyance direction downstream side FIG. 6 is a view for explaining a first facing surface and a second facing surface of a flange of a fixing device according to a second embodiment. The perspective view which shows the flange of FIG. FIG. 6 is a view for explaining a first facing surface and a second facing surface of a flange of a fixing device according to Embodiment 3. The perspective view which shows the flange of FIG. Sectional drawing which shows schematic structure of image forming apparatus The figure for explaining the angle of the opposite surface

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. Although the preferred embodiment of the present invention is an example of the best embodiment of the present invention, the present invention is not limited to the following embodiment, and various other configurations are possible within the scope of the idea of the present invention. It is possible to replace this with a known configuration.

[Example 1]
(1) Image forming apparatus 20
With reference to FIG. 15, an image forming apparatus equipped with a fixing device according to the present invention will be described. FIG. 15 is a cross-sectional view showing a schematic configuration of an example of an image forming apparatus (monochiro printer in this embodiment) 20 using an electrophotographic recording technique.

  In the image forming apparatus 20, an image forming unit 21 that forms an image on a recording material includes a photosensitive drum 22 as an image carrier, a charging member 23, a laser scanner 24, a developing device 25, a transfer member 26, and a photosensitive member. And a cleaner 27 for cleaning the outer peripheral surface of the drum. Since the operation of the image forming unit 21 described above is well known, detailed description thereof is omitted.

  The recording material P stored in the cassette 28 in the apparatus main body 20A is fed one by one by the rotation of the roller 29, and then conveyed to the transfer portion formed by the photosensitive drum 22 and the transfer member 26 by the rotation of the roller 30. . The recording material P onto which the toner image has been transferred by the transfer unit is sent to a fixing device (fixing unit) 31 and the toner image is heated and fixed on the recording material by the fixing device. The recording material P exiting the fixing device 31 is discharged to the tray 33 by the rotation of the roller 32.

(2) Fixing device 31
(2-1) Device Configuration The fixing device 31 shown in the present embodiment is a film heating type device. The fixing device 31 will be described with reference to FIGS. FIG. 1 is a perspective view showing a schematic configuration of the entire fixing device 31. FIG. 2 is a cross-sectional view showing a schematic configuration of the fixing device 31. 1 and 2, X is the recording material conveyance direction, Y is the longitudinal direction of the fixing device perpendicular to the recording material conveyance direction X (longitudinal direction of the film 8), and Z is the recording material thickness direction.

  The fixing device 31 includes a heating unit 5, a pressure roller 9 as a pressure rotator, left and right flanges 13 as restriction members, and a frame 6 that supports the heating unit, the pressure roller, and the flange. ing. In this example, the flange 13 corresponds to a part that fits into the frame 6.

  As shown in FIG. 2, the pressure roller 9 is provided on a core metal 9a, an elastic layer 9b made of silicone rubber, fluorine rubber or the like provided on the outer peripheral surface of the core metal, and on the outer peripheral surface of the elastic layer. And a release layer 9c made of PFA, PTFE, or the like. Here, PFA is a tetrafluoroethylene / perfluoroalkyl vinyl ether copolymer, and PTFE is polytetrafluoroethylene.

  As shown in FIG. 1, the pressure roller 9 is rotatably supported by the left and right side plates 6 a of the frame 6 via bearing members 16 in both ends of the core metal 9 a in the direction Y.

  As shown in FIG. 2, the heating unit 5 includes a rotatable cylindrical film 8, a plate-like heater 14 as a heating body, a holder 10 as a support member that supports the heater, and a pressure member. And stay 11.

  The holder 10 made of a heat-resistant resin material supports the heater 14 by a recess 10 a provided along a direction Y on a flat surface on the pressure roller 9 side. A stay 11 made of metal or a heat-resistant resin material is provided on the flat surface of the holder 10 opposite to the pressure roller 9 side. The cross-sectional shape of the stay 11 is U-shaped to reinforce the holder 10. The holder 10 that supports the heater 14 and is provided with the stay 11 is inserted through the hollow portion of the film 8.

  The heater 14 has an elongated ceramic substrate 14 a extending along the direction Y. On the surface of the substrate 14a on the side of the pressure roller 9, a resistance heating layer 14b made of silver palladium or the like that generates heat when energized is provided along the longitudinal direction of the substrate. The resistance heating layer 14b is covered with a glass coat as a protection layer 14c provided on the substrate 14a in order to ensure protection and insulation of the resistance heating layer.

  The film 8 is an elongated member extending along the direction Y. As the film 8, a single layer film or a composite layer film is used. As the single layer film, a sleeve made of a heat resistant resin material is used. As the composite film, use is made of a sleeve having a heat-treated polyimide (PI) or SUS thin film treated as a base layer, and a release layer provided on the sleeve surface by PTFE, PFA, or the like. .

  The configuration of the flange 13 will be described with reference to FIG.

  FIG. 3 is a perspective view showing the right flange 13 of FIG. Since the left flange 13 in FIG. 1 has the same configuration as the flange in FIG. 3, a detailed description thereof is omitted.

  The flanges 13 are provided on both sides of the film 8 in the longitudinal direction. Grooves 13 c are provided along the direction Z on the side surfaces of the flange 13 on the upstream side and the downstream side in the recording material conveyance direction X. On the other hand, on the side plate 6a, support portions 6a2 are formed on the upstream side and the downstream side in the recording material conveyance direction X so that the concave portion 6a1 is formed along the direction Z. In the direction Z, the flange is supported on the side plate by fitting the groove 13c of the flange 13 to the support portion 6a2 of the side plate 6a.

  Further, the flange 13 has a restricting portion 13b for restricting movement of the film 8 in the longitudinal direction in the direction Y. Further, the flange 13 has a support portion 13 a for supporting the end portion of the film 8 and a hole portion 13 d for supporting the end portion of the heating unit 5.

  The restricting portion 13 b is formed in a shape larger than the outer diameter of the film 8 in the direction Y. As a result, the end face 8a of the film 8 can be brought into contact with the restricting portion 13b.

  In the direction X, a support portion 13a is provided substantially at the center of the restriction portion 13b. The support portion 13a protrudes in the direction Y toward the film end surface 8a. The support portion 13 a is formed in a semicircular arc shape that can be inserted into the hollow portion of the film 8.

  Inside the support portion 13a, a hole portion 13d is provided along the direction Y. The hole 13d penetrates the restricting portion 13b. The heating unit is supported by the flange 13 by inserting and fitting the guide 10 of the heating unit 5 and the ends 10a and 11a of the stay 11 into the hole 13d.

  As shown in FIG. 1, the fixing device 31 has a pressure plate 12 that can swing in the direction Z with respect to the flange. The pressure plate 12 is pressed against the surface to be pressurized 13e (see FIG. 3) of the flange 13 by the pressure of the pressure spring 7 latched between the pressure plate 12 and the side plate 6a, whereby the flange is pressurized in the direction Z. The

  As shown in FIG. 2, the flange 13 pressurized in the direction Z pressurizes the holder 10 via the stay 11. The holder pushes the protective layer 14 c of the heater 14 toward the inner peripheral surface (inner surface) of the film 8, and further presses the outer peripheral surface (surface) of the film against the outer peripheral surface (surface) of the pressure roller 9. As a result, the elastic layer 9 b of the pressure roller 9 is crushed and elastically deformed, and a nip portion N having a predetermined width is formed in the direction X by the surface of the film 8 and the surface of the pressure roller 9.

(2-2) Heat Fixing Processing Operation As shown in FIG. 1, the gear 15 provided at one end of the cored bar 9a of the pressure roller 9 is rotationally driven in the direction of the arrow by a motor (not shown). Then, the pressure roller 9 rotates in the arrow direction shown in FIG. 2, and the film 8 follows the rotation of the pressure roller and rotates in the arrow direction shown in FIG.

  When electric power is supplied from a power source (not shown) to the resistance heating layer 14b of the heater 14, the resistance heating layer generates heat and the heater rapidly rises in temperature. A temperature control unit (not shown) takes in the heater temperature detected by the thermistor 15 (see FIG. 2) as a temperature detection member and supplies the heater temperature to the resistance heating layer 14b so as to maintain the heater temperature at a predetermined fixing temperature (target temperature). To control the power.

  The recording material P carrying the unfixed toner image T is heated while being conveyed by the nip portion N, whereby the toner image is fixed on the recording material.

(2-3) Support part 13a of flange 13
The support portion 13a of the flange 13 will be described with reference to FIGS.

  FIG. 4 is a perspective view of the right flange 13 and the right end of the film 8 supported by the support portion 13a of the flange as viewed from the upstream side in the recording material conveyance direction. FIG. 5 is a diagram showing a positional relationship between the support portion 13a of the right flange 13 and the film 8 whose rotation trajectory is restricted by the support portion.

  As shown in FIG. 4, the support portion 13a of the flange 13 has a facing surface 13a1 on the outer periphery of the support portion. The facing surface 13a1 is formed in a semicircular arc shape so that the film 8 can smoothly rotate in the circumferential direction of the film 8. The rotation path of the film 8 is regulated by sliding the film inner surface 8b on the facing surface 13a1.

  Due to component tolerances and assembly tolerances in the manufacture of the apparatus, the gap between the film inner surface 8b and the opposing surface 13a1 of the support portion 13a is reduced, or the peripheral length of the opposing surface 13a1 is longer than the inner peripheral length of the film. The sliding resistance of the film inner surface 8b with respect to the facing surface 13a1 is increased. Then, there is a possibility that a film slip in which the film 8 slides with respect to the pressure roller 9 or a film twist due to a difference in rotational speed between the end portion and the center of the film.

  Therefore, as shown in FIG. 5, there is an appropriate gap S1 between the film inner surface 8b and the facing surface 13a1 in consideration of component tolerances and assembly tolerances in manufacturing the apparatus so as not to prevent the rotation of the film 8. It is secured.

  Next, the relationship between the distance L between the restricting portions 13b of the left and right flanges 13 and the length L1 of the film 8 will be described with reference to FIG.

  FIG. 6 is a diagram showing the relationship between the distance L between the restricting portions 13 b of the left and right flanges 13 and the length L 1 of the film 8.

  When the film 8 is shifted (shifted), the film end surface 8a abuts against the restricting portion 13b of the flange 13 to restrict the displacement of the film. If the distance L between the restricting portions 13b of the left and right flanges 13 becomes smaller than the length L1 of the film 8 due to component tolerances and assembly tolerances in the manufacture of the apparatus, the restricting portions and the film end surface 8a interfere with each other to the film end portions. Buckling will occur. Therefore, L is set to be larger than L1 in consideration of the tolerances of the left and right flanges 13 and parts constituting the heating unit 5 and the thermal expansion of the film 8.

  Therefore, in the direction Y, there is a gap S <b> 2 that changes according to the above-described tolerance and the thermal expansion of the film 8 between the restricting portion 13 b of the left and right flanges 13 and the film end surface 8 a. That is, the film 8 can move in the film longitudinal direction by the gap S2. Therefore, as shown in FIGS. 4 and 6, the length L2 of the facing surface 13a1 of the support portion 13a is set so that the film falls off from the support portion 13a in the film longitudinal direction in consideration of the above-described tolerance and the thermal expansion of the film 8. The length is not set (L2> S2).

  Here, the generation mechanism in which the deviation occurs in the film 8 will be described with reference to FIG. 7 (Comparative Example 1).

  FIG. 7 is a view showing a state when a deviation occurs in the film 8. FIG. 7 shows the positional relationship between the left and right flanges 13 and the film 8. Arc length In FIG. 7, R is the direction of rotation of the film 8.

  When the pressure roller 9 and the film 8 are rotating, the pressure roller 9 and the film 8 are not necessarily parallel to each other, and may have a crossing angle due to the above tolerance. Even if the pressure roller 9 and the film 8 are parallel to each other, a difference occurs between the pressure forces of the left and right pressure springs 7, and depending on the orientation of the recording material P conveyed to the nip N, There may be a difference in the rotational speed of the end portion.

  In such a case, as shown in FIG. 7, the inner surface 8 b at the right end of the film may contact a downstream region in the direction X of the facing surface 13 a 1 of the right flange 13. Then, the right end portion side of the film 8 is inclined upstream in the recording material conveyance direction X by a gap 2S1 corresponding to twice the gap S1.

  When the right end side of the film 8 is tilted, when the film is rotated by the pressure roller 9, a force (film offset force) that moves the film in the longitudinal direction of the film toward the left flange 13 acts, and the film is shredded. Deviation occurs. At this time, the greater the inclination of the film 8, the greater the shifting force of the film.

  Due to the offset force of the film 8, the film approaches the left flange 13 and the film end surface 8a abuts against the restricting portion 13b. At this time, the film inner surface 8b slides in the upstream region in the direction X of the facing surface 13a1 of the support portion 13a of the flange 13 on the side closer to the film. As a result, a gap 2S1 corresponding to twice the gap S1 is generated between the facing surface 13a1 and the film inner surface 8b on the downstream side in the recording material conveyance direction. As a result, the right end portion side of the film 8 is inclined by the angle α to the upstream side in the recording material conveyance direction with respect to the left end portion side.

(2-4) Opposing surface upstream of recording material conveyance direction of support portion 13a The opposing surfaces 13a11 and 13a12 of the support portion 13a upstream of the recording material conveyance direction will be described with reference to FIG.

  8A is a view when the flange 13 is viewed from the side opposite to the pressure roller 9, and FIG. 8B is a view when the flange 13 of FIG. 8A is viewed from the outside in the film longitudinal direction. 8A and 8B, V is a virtual vertical surface (virtual surface) perpendicular to the center of the nip portion N (not shown) with respect to the recording material conveyance direction X.

  As described above, in order to reduce the inclination of the film 8 and reduce the shifting force of the film, it is necessary to reduce the gap S1 between the film inner surface 8b and the facing surface 13a1 of the support portion 13a of the flange 13. is there.

  However, if the circumferential length of the region of the opposing surface 13a1 of the support portion 13a is set large and, as a result, the gap S1 is further reduced due to the above-described tolerance, the film inner surface 8b and the opposing surface 13a1 when the film 8 is rotated Contact pressure increases. In the direction Y, the longer the region where the contact pressure between the film inner surface 8b and the facing surface 13a1 becomes higher, the more difficult the film rotates, and the greater the risk of film slipping, film twisting, and the like.

  As shown in FIGS. 8A and 8B, the facing surface 13a1 of the support portion 13a has a different arc length 2 in the direction X from the vertical surface V on the upstream side in the recording material conveyance direction. As one or more opposing surfaces, a first opposing surface 13a11 and a second opposing surface 13a12 are provided.

  As shown in FIG. 16, the first facing surface 13 a 11 and the second facing surface 13 a 12 are both surfaces that fit with the frame 6 of the component 13 and are fitted with the flat portion of the frame 6 of the component 13. The angles θ1 and θ2 formed with the mating surface 13c1 are surfaces that are substantially vertical. Specifically, the first facing surface 13a11 and the second facing surface 13a12 are both surfaces having angles θ1 and θ2 formed by the fitting surface 13c1 in the range of 86 ° to 94 °. Note that the surface SF is a virtual surface obtained by expanding the fitting surface 13c1.

  In the direction Y, the first facing surface 13a11 is provided at a position near the restricting portion 13b, and the second facing surface 13a12 is provided at a position far from the restricting portion. The first opposing surface 13a11 closer to the restricting portion 13b has a longer peripheral length extending along the inner surface 8b of the film 8 than the farther opposing surface 13a12. These facing surfaces 13a11 and 13a12 are both surfaces that come into contact with the film inner surface 8b to regulate the rotation trajectory of the film 8.

  Further, the circumference of the position where the facing surface 13a11 is provided is longer than the circumference of the position where the facing surface 13a1 of the comparative example 1 shown in FIG. 7 is provided, and the position where the facing surface 13a12 is provided. The circumference is equal to or less than the circumference of the position where the facing surface 13a1 of Comparative Example 1 shown in FIG. 7 is provided.

  The first facing surface 13a11 and the second facing surface 13a12 will be described in more detail.

  With reference to the vertical plane V, the arc length of the first facing surface 13a11 on the upstream side in the direction X is a, and the arc length of the first facing surface 13a11 on the downstream side in the direction X is a '. . In this embodiment, length a = length a ′. In addition, when the length of the arc of the second facing surface 13a12 on the upstream side in the direction X is b with respect to the vertical plane V, the length b is shorter than the length a. With reference to the vertical plane V, the arc length of the first facing surface 13a11 on the downstream side in the direction X and the arc length of the second facing surface 13a12 are the same (the contour is the same).

  Further, the length L21 in the direction Y of the first facing surface 13a11 is shorter than the total length L2 of the facing surface 13a1. The total length L2 of the facing surface 13a1 of this example is the same as the total length L2 of the facing surface 13a1 of Comparative Example 1 shown in FIG.

  Therefore, the flange 13 of this example is a region having a length L21 that is shorter than the total length L2 of the opposing surface 13a1 of the comparative example 1 shown in FIG. It has the opposing surface 13a11 which is an area | region of a big outline.

  The step portion between the first facing surface 13a11 and the second facing surface 13a12 is an inclined surface 13a13 that smoothly connects the first facing surface and the second facing surface. The surface 13a14 is a tapered surface provided at the tip of the support portion 13a. As shown in FIG. 16, the angle θ3 formed by the fitting surface 13c1 of the inclined surface 13a13 is smaller than 86 °, and the angle θ4 formed by the fitting surface 13c1 of the tapered surface 13a14 is 85 ° or less.

  When the film end surface 8a abuts against the restricting portion 13b of the flange 13, the film inner surface 8b slides with a portion on the upstream side in the direction X of the first facing surface 13a11. The sliding area is an area having a length L21. Since the surface shape of the first facing surface 13a11 is formed in an arc shape, the film 8 rotates smoothly.

  On the other hand, when the film end surface 8a does not hit any of the restricting portions 13b of the left and right flanges 13, the film inner surface 8b is either one of the first facing surface 13a11 and the second facing surface 13a12, or Slide on both opposing surfaces. Moreover, the area | region where the rotation track | orbit of the film 8 is controlled by the opposing surface 13a11 and the opposing surface 13a12 will change with said tolerance and the thermal expansion of a film. Therefore, the surface shape of the second facing surface 13a12 is also formed in an arc shape that allows the film 8 to rotate smoothly.

  Therefore, since the rotation trajectory of the film 8 can also be regulated by the second facing surface 13a12, even if the length L21 of the first facing surface 13a11 is shorter than the length L2 necessary for preventing the film from dropping off, the film The occurrence of slip and film twist can be reduced.

  Next, the reason why the first facing surface 13a11 and the second facing surface 13a12 are provided will be described with reference to FIG. 9 (Example) and FIG. 10 (Comparative example).

  FIG. 9 is a view showing the left and right flanges 13 and the film 8 provided with the first facing surface 13a11 and the second facing surface 13a12. FIG. 10 is a diagram showing a second comparative example.

  As shown in FIGS. 9 and 10, the film 8 is detached from the region of the first facing surface 13 a 11 of the flange 13 on the opposite side to the film-shifting direction due to variations in manufacturing tolerances in the film longitudinal direction of the film 8. The lever region may make it impossible to regulate the rotation trajectory of the film.

  As shown in FIG. 9, when the film inner surface 8b slides on the facing surface 13a1 of the support portion 13a of the flange (right side flange) 13 opposite to the direction close to the film, the film 8 is rotated by the first facing surface 13a11. The orbit cannot be regulated. In that case, the film end portion 8a of the film 8 abuts against the restricting portion 13b of the flange (left flange) 13 on the side where the film approaches, and the film inner surface 8b becomes the first opposing surface 13a11 (the left flange 13 of FIG. 9). It slides on the facing surface 13a11).

  As described above, the contour of the region of the first facing surface 13a11 is larger than the contour of the facing surface 13a1 of Comparative Example 1. As a result, the right end portion of the film 8 is inclined at an angle β (<α) toward the upstream side in the recording material conveyance direction with respect to the left end portion.

  Further, as in Comparative Example 2 shown in FIG. 10, when a portion having an enlarged outline is provided on the downstream side in the recording material conveyance direction, the film 8 is in the recording material conveyance direction with the right end side of the film relative to the left end side. Tilt upstream by angle γ.

  When comparing the angles β and γ in FIGS. 9 and 10, β is smaller than γ. Therefore, when the first facing surface 13a11 of the flange 13 is provided on the upstream side in the recording material conveyance direction, the shifting force of the film can be reduced as compared with the case where it is provided on the downstream side in the recording material conveyance direction.

  In the fixing device 31 of this embodiment, when the film 8 is displaced, the first facing surface 13a11 having a large outline regulates the rotation trajectory of the film. Therefore, since the inclination angle of the film 8 can be reduced, the shifting force of the film 8 can be reduced, and damage to the film end can be suppressed. Further, since the length L21 of the first facing surface 13a11 is short, the rotational resistance of the film 8 can be suppressed even if the contour of this portion is increased. Moreover, since the 2nd opposing surface 13a12 is provided, it can prevent that the film 8 falls off from a flange.

[Example 2]
Another example of the fixing device 31 will be described. In the present embodiment, only the configuration of the fixing device 31 different from that of the first embodiment will be described.

  11 and 12 show the flange 13 of the fixing device 31 of this embodiment. 11A is a view when the flange 13 is viewed from the side opposite to the pressure roller 9, and FIG. 11B is a view when the flange 13 of FIG. 11A is viewed from the outside in the film longitudinal direction. FIG. 12 is a perspective view when the right flange 13 is viewed from the upstream side in the recording material conveyance direction.

  As shown in FIGS. 11 and 12, the flange 13 of the present embodiment is provided with a first facing surface 13 a 11 and a second facing surface 13 a 12 over the entire circumferential direction of the support portion 13 a of the flange 13. The step portion between the first facing surface 13a11 and the second facing surface 13a12 is an inclined surface 13a13 that smoothly connects the first facing surface and the second facing surface.

  The fixing device 31 of the present embodiment can achieve the same effects as those of the first embodiment. Further, since the shifting force of the film 8 can be reduced, the risk of occurrence of film slip and film twist can be reduced as in the first embodiment.

[Example 3]
Another example of the fixing device 31 will be described. In the present embodiment, only the configuration of the fixing device 31 different from that of the first embodiment will be described.

  13 and 14 show the flange 13 of the fixing device 31 of the present embodiment. 14A is a view when the flange 13 is viewed from the side opposite to the pressure roller 9, and FIG. 14B is a view when the flange 13 of FIG. 14A is viewed from the outside in the thrust direction of the film 8. . FIG. 14 is a perspective view of the right flange 13 as viewed from the upstream side in the recording material conveyance direction.

  As shown in FIGS. 13 and 14, a first facing surface 13a11 and a second facing surface 13a12 are provided on the upstream side of the support portion 13a of the flange 13 in the recording material conveyance direction. In the longitudinal direction of the film 8, the first facing surface 13a11 and the second facing surface 13a12 are inclined surfaces that are smoothly connected.

  The fixing device 31 of this embodiment can also achieve the same effect as that of the first embodiment.

[Other embodiments]
In the fixing device 31 shown in the first to third embodiments, the flange 13 has two opposing surfaces 13a11 and 13a12 in the longitudinal direction of the film 8, but may have three or more. For example, when there are three facing surfaces, the contour of the facing surface may be increased as the facing surface is closer to the restricting portion 13b.

  8: Film, 8a: End surface of film, 8b: Inner surface of film, 9: Pressure roller, 13: Flange, 13b: Restriction part, 13a11: First restriction surface, 13a12: Second restriction surface, N: Nip , P: Recording material, T: Unfixed toner image

Claims (8)

A fixing device for fixing an image formed on a recording material to the recording material,
The frame of the device,
Components that fit into the frame of the device;
A cylindrical film that rotates while in contact with the recording material;
A support part disposed in a position facing the end in the longitudinal direction of the film in the internal space of the film, the support part provided in the component;
A roller that contacts the outer peripheral surface of the film and forms a nip portion for nipping and conveying the recording material between the film and the film,
The support portion includes a first facing surface facing an inner surface of an end portion in the longitudinal direction of the film, and a second facing surface facing an inner surface in the longitudinal direction of the film with respect to the first facing surface. And both the first facing surface and the second facing surface are surfaces that fit with the frame of the component and are opposed to the flat portion of the frame of the component. The angle between the surface and the surface is almost vertical,
The fixing device according to claim 1, wherein a contour of the first facing surface is larger than a contour of the second facing surface when the component is viewed along the longitudinal direction of the film.   The first opposing surface and the second opposing surface are both surfaces having an angle between the fitting surface and 86 ° or more and 94 ° or less. Fixing device.   2. The two surfaces having different contours are provided only on the upstream side of the support portion with reference to a virtual surface orthogonal to the center of the nip portion in the recording material conveyance direction. 3. The fixing device according to 2.   The two surfaces having different contours are provided on both the upstream side and the downstream side of the support portion with reference to a virtual surface orthogonal to the center of the nip portion in the recording material conveyance direction. The fixing device according to claim 1.   The fixing device according to claim 1, wherein an inclined surface is provided between the first facing surface and the second facing surface.   6. The fixing device according to claim 1, wherein the component has a regulation surface against which an end face of the film abuts when the film moves in the longitudinal direction. 7.   The fixing device according to claim 1, further comprising a heater that contacts an inner surface of the film.   The fixing device according to claim 7, wherein the nip portion is formed by the heater and the roller through the film.