Fixing device

Abstract

To provide a fixing device that allows a reduction in assembly man-hours.SOLUTION: A fixing device has a heating rotating body and a pressure rotating body, and fixes a toner image to a recording material. The fixing device has: a flange that restricts the movement of a film in a longitudinal direction of the film and supports a heater; a fixing frame that supports the pressure rotating body, the fixing frame having positioning holes formed therein; a pressure member that applies pressure to the flange; and a sheet metal that has a pressure target part applied with pressure by the pressure member, and insertion parts inserted into the positioning holes. In a first state in which the pressure member is contracted, the positions of the insertion parts are determined by the positioning holes, and in a second state in which the pressure member is further contracted from the first state, the insertion parts can be removed from the positioning holes.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a fixing device that applies heat and pressure to an unfixed toner image to fix it. [Background technology]

[0002] The image forming apparatus has a fixing device that fixes the unfixed toner image onto the recording material.

[0003] The fixing device according to the present invention includes a heater, a thin film, and a pressure roller. The pressure roller is driven to rotate by being pressed against the heater via the film, forming a nip. An unfixed toner image is sandwiched and conveyed through the nip, and is fixed to the recording material by being heated by the heater via the film.

[0004] Patent Document 1 discloses a configuration relating to a pressure mechanism of a fixing device.

[0005] A pressure spring is used in a pressure mechanism that applies pressure to an unfixed toner image to fix it on a recording material.

[0006] Flanges are attached to both longitudinal ends of the heater to restrict the film from moving in the longitudinal direction. A pressure spring presses the flanges in the direction of the pressure roller, generating a pressure force.

[0007] The pressure spring is disposed between the flange and a metal plate fixed to the fixing frame that supports the pressure roller.

[0008] During assembly, the pressure spring is pressed against the flange by a metal plate held by hand. When pressed, the pressure spring contracts from its natural length. With the pressure spring in its contracted state, the metal plate is fixed to the fixing frame. Screws were used to fix the metal plate to the fixing frame. By fixing the metal plate to the fixing frame, the pressure spring was maintained in a contracted state between the flange and the metal plate, generating pressure. [Prior art documents] [Patent documents]

[0009] [Patent Document 1] Patent Publication No. 2003-122147 Summary of the Invention [Problem to be solved by the invention]

[0010] Conventionally, screws have been used to secure the metal plate to the fixing frame. This requires the assembly worker to turn the screws while suppressing the spring's restoring force, resulting in a large number of assembly steps. Therefore, there was a need to reduce the assembly steps required to position the metal plate on the fixing frame.

[0011] Therefore, the fixing device according to the present invention makes it possible to reduce the number of assembly steps. [Means for solving the problem]

[0012] In order to solve the above problems, a fixing device according to the present invention comprises: a first rotating body that heats the recording material; a second rotating body that is rotatably configured and presses the first rotating body, forming a nip portion together with the first rotating body, and fixing the toner image onto the recording material together with the first rotating body when the recording material carrying an unfixed toner image passes through the nip portion; a pressure member that presses the second rotating body toward the first rotating body; a metal plate that comes into contact with one end side of the pressure member and has a pressure-receiving portion that receives pressure from the pressure member; and a metal plate that comes into contact with the other end side of the pressure member and has a pressure-receiving portion that receives pressure from the pressure member. a pressure lever that receives pressure from the first rotating body and the second rotating body, the pressure lever being movable between a first position where the first rotating body and the second rotating body are pressed and a second position where the pressure between the first rotating body and the second rotating body is released; a fixing frame portion that supports the second rotating body, the fixing frame portion including a first side portion disposed upstream of the nip portion in the recording material conveyance direction and a second side portion disposed downstream of the nip portion in the recording material conveyance direction; a first hole portion that is provided in the first side portion and into which a first end of the metal plate is inserted; and a second hole portion into which a second end of the metal sheet is inserted, the first hole portion and the second hole portion being provided such that, when the first end of the metal sheet is inserted into the first hole portion and the second end of the metal sheet is inserted into the second hole portion, the position of the metal sheet is movable to a first predetermined position and a second predetermined position which are different in the pressure direction of the pressure member, and when the metal sheet is positioned at the first predetermined position, the pressure member is compressed between the metal sheet and the pressure lever in a first state, and the first end of the metal sheet is inserted into the When the metal plate is engaged with the first hole portion, the position of the first end of the metal plate is determined in a third direction perpendicular to a first direction in which the pressure member applies pressure and a second direction that is the longitudinal direction of the first rotor, and when the metal plate is positioned at the second predetermined position, the pressure member is compressed between the metal plate and the pressure lever in a second state in which the pressure member is compressed more than in the first state, and the engagement between the first end of the metal plate and the first hole portion is released, thereby making the metal plate detachable. It is characterized by: [Effects of the Invention]

[0013] According to the present invention, the metal plate can be fixed to the fixing frame without using screws. [Brief explanation of the drawings]

[0014] [Figure 1] FIG. 1 is a schematic cross-sectional view of an image forming apparatus. [Figure 2] FIG. 2 is a schematic cross-sectional view of the fixing device. [Figure 3] FIG. 3 is a cross-sectional view taken along line XX in FIG. 2. [Figure 4] FIG. [Figure 5A] FIG. 4 is a schematic cross-sectional view of the pressure mechanism in a pressure state. [Figure 5B] FIG. 10 is a schematic cross-sectional view of the pressure mechanism in a pressure-released state. [Figure 6A]Schematic diagrams of the metal plate and the fixing frame from viewpoints v1, v2, and v3. [Figure 6B] This is an enlarged view of both ends of the metal plate as seen from viewpoint v1. [Figure 7A] 10 is a schematic view of the pressure mechanism when the first insertion portion is inserted into the positioning hole. FIG. [Figure 7B] 10 is a schematic diagram of a pressure mechanism when a first insertion portion and a second insertion portion are inserted into positioning holes. FIG. [Figure 7C] 10 is a schematic diagram of a pressure mechanism when the metal plate is positioned on the fixing frame. FIG. [Figure 8] This is a modified example of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0015] <Embodiment> <Image forming device> Fig. 1 is a schematic cross-sectional view of an image forming apparatus 1. As shown in Fig. 1, image forming apparatus 1 is a tandem intermediate transfer full-color printer in which yellow, magenta, cyan, and black image forming units PY, PM, PC, and PK are arranged along the moving direction of intermediate transfer belt 31.

[0016] The image forming process will be explained using the image forming unit PY as an example.

[0017] First, in the image forming station PY, the charging device 12Y uniformly charges the surface of the photosensitive drum 11Y. Once the surface of the photosensitive drum 11Y is uniformly charged, the exposure device 13Y irradiates the photosensitive drum 11Y with a laser according to image data, forming an electrostatic latent image on the surface of the photosensitive drum 11Y. Thereafter, the developing device 14Y deposits yellow toner onto the photosensitive drum 11Y, forming a yellow toner image on the surface of the photosensitive drum 11Y. Thereafter, the formed yellow toner image is primarily transferred to the intermediate transfer belt 31 by applying a voltage to the primary transfer blade 17Y. After the primary transfer, any yellow toner remaining on the photosensitive drum 11Y that has not been transferred is scraped off and removed by the cleaning blade 15Y.

[0018] This series of processes is similarly carried out in the image forming units PM, PC, and PK, whereby a full-color toner image is formed on the intermediate transfer belt 31.

[0019] The full-color toner image on the intermediate transfer belt 31 is fed to a secondary transfer portion T2 formed by a pair of secondary transfer rollers 34, 35. Then, the full-color toner image on the intermediate transfer belt 31 is transferred (secondary transfer) onto recording materials P taken out one by one from the recording material cassette 20. At this time, the full-color toner image on the intermediate transfer belt 31 is not yet fixed to the recording material P. This unfixed full-color toner image is referred to as unfixed toner.

[0020] Specific examples of the recording material P include plain paper, resin sheets, coated paper, cardboard, and sheets for overhead projectors.

[0021] The recording material P carrying the unfixed toner image passes through the secondary transfer portion T2, and is then transported to the fixing device 40. When transported to the fixing device 40, the recording material P carrying the unfixed toner image is subjected to heat and pressure by the fixing device 40, and the toner image is fixed to the recording material P. After passing through the fixing device 40, the recording material P with the fixed toner image is discharged to the paper discharge tray 64.

[0022] On the other hand, a case where a toner image is formed on both sides of recording material P will be described. After the toner image on one side has been fixed by fixing device 40, recording material P is conveyed to conveying path 73 by flapper 61. Recording material P is conveyed in a switchback manner on conveying path 73. After being conveyed in a switchback manner, recording material P passes through double-sided conveying path 70. Then, the toner image is secondarily transferred to the other side of recording material P at secondary transfer section T2. ​​After that, recording material P, after the toner image on the other side has been fixed by fixing device 40, is discharged to external tray 64.

[0023] <Fixing device used in the present invention> Next, the fixing device 40 used in the present invention will be described with reference to FIGS.

[0024] Fig. 2 is a schematic cross-sectional view of the fixing device, Fig. 3 is a cross-sectional view taken along line XX in Fig. 2, and Fig. 4 is a perspective view of the fixing device.

[0025] As shown in FIG. 2, the fixing device 40 includes a fixing film 100, a heater 102, and a pressure roller 101.

[0026] The fixing film 100 is a rotatable, endless film, and the heater 102 is in contact with the inner circumferential surface of the fixing film. The heater 102 has a heating resistor (not shown), and generates heat when a current flows through the heating resistor. When the heater 102 generates heat, the heat is transferred to the outer circumferential surface of the fixing film 100. The fixing film 100 is made of a thin film with high thermal conductivity. Therefore, the heat of the heater 102 is efficiently transferred to the outer circumferential surface of the fixing film 100. This allows the temperature of the outer circumferential surface of the fixing film 100 to reach a temperature exceeding the toner melting point temperature in a short time. This shortens the time from when a printing request is made to when the recording material is discharged. In addition, there is no need to constantly raise the temperature of the heater 102, thereby realizing power savings.

[0027] The pressure roller 101 forms a nip N by contacting the heater 102 with the fixing film 100 interposed therebetween. The pressure roller 101 is rotated in the direction of arrow A in FIG. 2 by a rotation drive motor (not shown). This causes the fixing film 100 to rotate.

[0028] The pressure roller 101 has a cylindrical core made of a metal such as iron or aluminum, and an elastic layer made of silicone rubber disposed on the outer surface of the cylindrical core. A release layer made of PFA resin is disposed on the outer surface of the elastic layer. The cylindrical core of the pressure roller 101 extends outward beyond the fixing film 100 in the longitudinal direction of the fixing film 100. Therefore, both ends of the pressure roller 101 protrude outward beyond the fixing film 100 in the longitudinal direction of the fixing film.

[0029] 4, a bearing member 116 that supports the rotational drive of the pressure roller 101 is disposed on the protruding cylindrical core metal portion. The bearing member 116 is supported by the fixing frame 115. Therefore, the fixing device 40 according to the present invention has a configuration in which both end portions of the pressure roller 101 are supported by the fixing frame 115.

[0030] When the recording material P is conveyed to the nip portion N, heat and pressure from the heater 102 are applied to the recording material P. Then, as the pressure roller 101 is driven to rotate, the recording material P is sandwiched and conveyed between the pressure roller 101 and the fixing film 100, and the toner image is fixed onto the recording material P.

[0031] <Pressure mechanism of fixing unit> The pressure mechanism 130 of the fixing device 40 will be described with reference to FIGS.

[0032] The recording material P is nipped and conveyed between a pressure roller 101 and a fixing film 100. In order to fix the unfixed toner image onto the recording material P, a pressure of at least a certain level is required.

[0033] The heater 102 is supported by a support member 103 that supports the heater. The support member 103 has a shape that extends outward from the fixing film 100 in the longitudinal direction of the fixing film 100, and is disposed inside the fixing film 100. The support member 103 has a groove on the nip portion N side into which the heater 102 is fitted. A metal stay 104 abuts against the support member 103. The stay 104 has a U-shape that extends in the longitudinal direction of the fixing film.

[0034] 3 has fitting portions 105a that sandwich both ends of the support member 103 and are fitted into both ends of the stay 104, restricting portions 105b that restrict movement of the fixing film 100 in the longitudinal direction of the fixing film, and a pressure-receiving portion 105c. When the pressure-receiving portion 105c of the flange 105 fitted into both ends of the stay 104 is pressed, the fitted stay 104 presses the support member 103, and the heater 102 supported by the support member presses the pressure roller 101 via the fixing film 100.

[0035] The pressure roller 101 that applies pressure is supported by a fixing frame 115 made of metal.

[0036] As a result, a nip portion N is formed, and pressure is generated to fix the unfixed toner image onto the recording material P.

[0037] The pressure mechanism 130 that applies pressure to the pressure-receiving portion 105c of the flange will be described with reference to FIG.

[0038] The pressure mechanism 130 has a pressure spring 113 which is a pressure member that generates a pressure force for forming the nip portion N. One end of the pressure spring 113 abuts against the pressure-receiving portion 114a of the metal plate 114. The other end of the pressure spring 113 abuts against the pressure lever 112. The pressure spring 113 applies pressure to the pressure lever 112 using the restoring force that causes it to return to its natural length.

[0039] When the fixing device 40 is assembled, the pressure spring 113 is in a state (first state) where it is contracted from its natural length. Therefore, the pressure spring 113 has a restoring force that tries to return it to its natural length from the first state. This restoring force causes the pressure spring 113 to pressurize the pressure lever 112. The pressure lever 112 abuts against the pressure-receiving portion 105c of the flange. Therefore, the pressure spring 113 presses the flange 105 via the pressure lever 112. This generates a pressure force that presses the recording material P.

[0040] 5, the direction in which the pressure spring 113 presses the flange 105 is defined as a pressure direction P. The direction opposite to the pressure direction P is defined as a repulsion direction R.

[0041] The switching between the pressurized state (a) and the pressure-released state (b) will be explained using FIG.

[0042] The pressure lever 112 is rotatable about a support shaft 112b as a fulcrum. The pressure lever 112 is pressed by a pressure spring 113, and presses the pressure-receiving portion 105c of the flange.

[0043] Eccentric cam 120 is connected to a motor. The motor rotates eccentric cam 120. When eccentric cam 120 receives drive from the motor, eccentric cam 120 rotates 180° around drive shaft 120a. As a result, the eccentric cam pushes up pressure applying lever 112, as shown in FIG. 5B. This causes pressure applying lever 112 to no longer apply pressure to pressure applying portion 105c of the flange, resulting in a pressure release state (b).

[0044] In the pressure-released state, when a motor (not shown) rotates the eccentric cam 180 degrees, the eccentric cam 120 and the pressure lever are no longer in contact with each other. Then, the pressure lever 112, which is pressurized by the pressure spring 113, presses the pressure-receiving portion 105c of the flange. This creates a pressure-receiving state (a) in which the nip N is formed.

[0045] <Positioning the metal plate on the fixing frame> Conventionally, screws have been used to fix the metal plate 114 to the fixing frame 115. The screws must be rotated while maintaining the pressure spring 113 in a compressed state. This increases the number of assembly steps required when assembling the fixing device 40. Therefore, there has been an issue of wanting to refrain from using screws when fixing the metal plate 114 to the fixing frame 115.

[0046] Therefore, the present invention is configured to position the metal plate 114 on the fixing frame 115 without using screws. A detailed description of this will be given below.

[0047] <Shape of fixing frame> As shown in FIG. 4, the fixing frame 115 has a groove into which the restricting portion 105b of the flange is fitted, and the fixing frame 115 restricts the movement of the flange 105 in the short-side direction of the fixing film.

[0048] As shown in FIG. 5A, the fixing frame 115 has two side plates 115a and 115b. The side plates 115a and 115b are located outside the fixing film 100 in the longitudinal direction of the fixing film. The side plates 115a and 115b are also arranged opposite each other in the transverse direction of the fixing film. Both the side plates 115a and 115b are made of a metal such as iron and are highly durable. A flange 105 and a pressure spring 113 are arranged inside the side plates 115a and 115b.

[0049] In the repulsion direction R, positioning holes 122 and 123 into which the metal plate 114 is inserted are formed at the end of the side plate 115a and the end of the side plate 115b, respectively.

[0050] <Shape of positioning holes provided on the fixing frame> The shape of the positioning holes provided in the fixing frame in this embodiment will be described using FIG. 6A. Positioning holes 122 and 123 have a first side, a second side, and a diagonal side. The first side is shorter than the second side. The first side of positioning hole 122 corresponds to 122a, and the second side corresponds to 122b. The first side of positioning hole 123 corresponds to 123a, and the second side corresponds to 123b. V1 in FIG. 6A is a view of fixing device 40 viewed from above with metal plate 114 facing upward. V2 in FIG. 6A is a view of positioning hole 123 viewed from the direction of arrow V2 shown in FIG. 7A. V3 in FIG. 6A is a view of positioning hole 122 viewed from the direction of arrow V3 shown in FIG. 7A.

[0051] The first side is a side in the rebound direction R, and the second side is a side in the pressure direction P.

[0052] The oblique sides 122c and 123c are sides that connect the first side and the second side.

[0053] The positioning hole 122 has two oblique sides 122c, but is not limited to two like the positioning hole 123, and may have only one oblique side.

[0054] The shape of the positioning hole 122 will be described. As shown in V3 of Fig. 6A, the first side 122a is disposed upstream in the pressure direction P, and the second side 122b is disposed downstream in the pressure direction P. In addition, the positioning hole 122 has an oblique side 122c formed therein.

[0055] The shape of the positioning hole 123 will be described. As shown in V2 of Fig. 6A, the first side 123a is disposed upstream in the pressure direction P, and the second side 123b is disposed downstream in the pressure direction P. In addition, the positioning hole 123 is formed with an oblique side 123c.

[0056] <Sheet metal shape> The shape of the metal plate 114 in this embodiment will be described with reference to FIGS. 6A and 6B.

[0057] The metal plate 114 has a metal plate pressure-receiving portion 114a that receives the restoring force of the pressure spring 113, and insertion portions 114b and 114c that are inserted into the positioning holes.

[0058] The first insertion portion 114b and the second insertion portion 114c are formed shorter in the longitudinal direction of the fixing film than the metal pressure-receiving portion 114a. By making the pressure-receiving portion 114a wider in the longitudinal direction than the insertion portion 114b, the area over which the pressure spring 113, which is a pressure-receiving member, can pressurize the pressure-receiving portion 114a is increased. This allows the pressure-receiving portion 114a to stably receive the pressure from the pressure spring 113.

[0059] The second insertion portion 114c has a first restricting portion 114d and a second restricting portion 114e that restrict movement of the metal plate 114 in the short-side direction of the fixing film. By having these restricting portions, the second insertion portion 114c has three widths in the long-side direction of the fixing film. The first is width L1, which includes the width of the first restricting portion 114d. The second is width L2, which includes the second restricting portion 114e. The third is width L3, which does not include the first restricting portion 114d and the second restricting portion 114e.

[0060] L1 is longer than the first side 123a and shorter than the second side 123b, and L2 is longer than the first side 123a.

[0061] L3 is shorter than or has the same width as first side 123a. However, if L3 and the width of first side 123a are the same, there is a possibility that second positioning portion 114c and side plate 115b may interfere with each other, and there is a risk that second positioning portion 114c and first side 123a may not abut against each other. Therefore, it is preferable that L3 be shorter than first side 123a.

[0062] In the longitudinal direction of the fixing film, the width L4 of the first insertion portion 114b is shorter than or equal to the width of the first side 122a. However, if L4 and the width of the first side 122a are the same, there is a risk of interference between the first insertion portion 114b and the side plate 115a. Therefore, it is preferable that L4 be shorter than the first side 122a.

[0063] <Metal sheet positioning method> A method for fixing the metal plate 114 to the fixing frame 115 will be described with reference to FIG.

[0064] 7A, the pressure spring 113 is pressurized in the pressure direction P by pressing the metal plate 114 in the pressure direction P. The pressurized pressure spring 113 is held at a length X2 that is shorter than its natural length. While the pressure spring 113 is held at the length X2 (second state), the first insertion portion 114b is inserted into the positioning hole 122.

[0065] 7B, second insertion portion 114c is inserted into positioning hole 123. At this time, second insertion portion 114c is inserted so that the portion having width L3 is disposed inside positioning hole 123.

[0066] Thereafter, by releasing the force pressing the metal plate 114 in the pressure direction P, as shown in FIG. 7C , the metal plate 114 is moved in the repulsion direction R by the restoring force of the pressing spring 113. At this time, the first insertion portion 114b abuts against the first edge 122a. This restricts the movement of the metal plate 114 in the pressure direction P or the repulsion direction R. At this time, the length of the pressing spring 113 changes from X2 (second state) to X1 (first state). X1 is shorter than the natural length of the pressing spring 113 and longer than X2. The pressing spring 113 in the X1 state has a restoring force that tries to return to its natural length. This restoring force is equal in magnitude to the force that presses the flange 105 and forms the nip portion N.

[0067] Both ends of the metal plate 114 are inserted into the positioning holes 122 and 123. Therefore, the range of movement of the metal plate 114 in the longitudinal direction of the fixing film is the width of the first sides 122a and 123a.

[0068] A case will be described where the insertion portion 114bc abuts against the oblique side when inserted into the positioning holes 122, 123. When the oblique side 123c and the second insertion portion 114c abut, the second insertion portion 114c is guided along the oblique side 123c to the first side 123a. Similarly, when the oblique side 122c and the first insertion portion 114b abut, the first insertion portion 114b is guided along the oblique side 122c to the first side 123a. The first insertion portion 114b is guided along the oblique side 122c from upstream to downstream in the repulsion direction R to the first side 123a. Thus, the metal plate 114 is easily positioned in the fixing frame 115.

[0069] In this embodiment, in which the pressure rotating body 101 is disposed between the metal plate 115ab and the fixing frame 115, the surface of the side plate 115ab on which the pressure rotating body 101 is disposed is referred to as the inner surface. When the metal plate 114 is positioned in the fixing frame 115, the insertion portion bc is inserted from the inner surface toward the outer surface of the side plate 115ab, with a portion of the insertion portion bc protruding from the side plate 115bc. Note that this is not limited to the case in which a portion of the insertion portion bc protrudes from the side plate 115ab. The insertion portion bc may be configured to fit within the positioning holes 122, 123.

[0070] The following description is based on the assumption that the metal plate 114 is positioned on the fixing frame 115. L1 shown in FIG. 6B is longer than the first side 123a, and L2 is longer than the first side 123a. Therefore, the first restricting portion 114d and the second restricting portion 114e sandwich the side plate 115b. This restricts movement of the metal plate 114 in the short-side direction of the fixing film.

[0071] The following describes how to remove the metal plate from the fixing frame. When the insertion portion 114ab of the metal plate 114 is positioned by the positioning holes 123, 123, the pressure spring 113 is in the first state. The pressure spring 113 is pressed in the direction of arrow P until it reaches the second state. Then, the insertion portion 114bc comes into contact with the positioning holes 122b and 123b, respectively. Then, either the insertion portion 114b or 114c is removed from the positioning hole. Then, the removed insertion portion moves in the direction of arrow R, allowing the metal plate 114 to be removed from the fixing frame 115.

[0072] Therefore, the metal plate 114 is fixed to the fixing frame 115 .

[0073] <Variation 1> A modified example as shown in Fig. 8 may also be used. In the modified example shown in Fig. 8, an insertion hole longer than the length in the plate thickness direction of the side plate 115b is provided in the second insertion portion 114c. Of the sides of the hole forming the insertion hole, the outer side in the short-side direction of the fixing film corresponds to the first restriction portion 114d of this embodiment. The inner side in the short-side direction of the fixing film corresponds to the second restriction portion 114e of this embodiment.

[0074] The modified example has the same effect as the present embodiment in that the metal plate 114 can be fixed to the fixing frame without using screws. [Explanation of symbols]

[0075] 1. Image forming device 40 Fixing device 100 Fixing Film 101 pressure roller 102 Heater 105 flange 105c Pressure receiving part 112 Pressure lever 113 Pressure spring 114 Sheet Metal 114a Sheet metal pressure part 114b first positioning portion 114c second positioning portion 114d First Regulatory Section 114e Second Regulatory Division 115 Fixing Frame 115ab side plate 122 Positioning hole 122a: First side of the positioning hole 122 122b: second side of the positioning hole 122 122c: Oblique side of the positioning hole 122 123 Positioning hole 123a: First side of the positioning hole 123 123b: second side of the positioning hole 123 123c: Oblique side of the positioning hole 123

Claims

1. A first rotating body that heats a recording material; a second rotating body that is rotatably configured and presses the first rotating body, forming a nip portion together with the first rotating body, and fixing the toner image onto the recording material together with the first rotating body when the recording material carrying the unfixed toner image passes through the nip portion; a pressure member for pressing the second rotor toward the first rotor; a metal plate having a pressure-receiving portion that is in contact with one end side of the pressure member and receives pressure from the pressure member; a pressure lever that comes into contact with the other end side of the pressure member and receives pressure from the pressure member, the pressure lever being movable between a first position where the first rotating body and the second rotating body are pressed and a second position where the pressure between the first rotating body and the second rotating body is released; a fixing frame portion that includes a first side portion disposed upstream of the nip portion in the recording material conveyance direction and a second side portion disposed downstream of the nip portion in the recording material conveyance direction, and that supports the second rotating body; a first hole provided in the first side portion and into which a first end of the metal plate is inserted; a second hole portion provided in the second side portion and into which the second end portion of the metal plate is inserted, the first hole portion and the second hole portion are provided so that the position of the metal plate can be moved to a first predetermined position and a second predetermined position that are different in a pressure direction of the pressure member when the first end of the metal plate is inserted into the first hole portion and the second end of the metal plate is inserted into the second hole portion, When the metal plate is positioned at the first predetermined position, the pressure member is compressed in a first state between the metal plate and the pressure lever, and the first end of the metal plate is engaged with the first hole portion, thereby determining the position of the first end of the metal plate in a third direction perpendicular to a first direction in which the pressure member applies pressure and a second direction that is the longitudinal direction of the first rotor, When the metal plate is positioned at the second predetermined position, the pressure member is compressed between the metal plate and the pressure lever in a second state that is more compressed than in the first state, and the engagement between the first end of the metal plate and the first hole portion is released, thereby making the metal plate detachable.

2. The fixing device described in claim 1, characterized in that the first end of the metal plate includes a first insertion portion that is inserted into the first hole portion, a first regulating portion that regulates movement of the first end when the first end moves in a first predetermined direction along the third direction, and a second regulating portion that regulates movement of the first end when the first end moves in a second predetermined direction opposite to the first predetermined direction along the third direction.

3. The first hole portion is configured to restrict the range of movement of the first end of the metal plate in the longitudinal direction of the first rotating body to a first range when the metal plate is located at the second predetermined position, and to restrict the range of movement of the first end of the metal plate in the longitudinal direction to a second range narrower than the first range when the metal plate is located at the first predetermined position; The fixing device described in claim 1 or 2, characterized in that the second hole portion is configured to restrict the movement range of the second end of the metal plate in the longitudinal direction of the first rotating body to a third range when the metal plate is located at the second predetermined position, and to restrict the movement range of the second end of the metal plate in the longitudinal direction to a fourth range narrower than the third range when the metal plate is located at the first predetermined position.

4. 4. The fixing device according to claim 1, wherein the pressure member is a pressure spring having elasticity.

5. A flange is provided to regulate the movement of the first rotating body in the longitudinal direction of the first rotating body, 5. The fixing device according to claim 1, wherein the pressure lever presses the first rotating body toward the second rotating body via the flange.

6. A fixing device described in any one of claims 1 to 5, characterized in that the first rotating body is an endless film.

Images