JP2015087464A - Pressing member, fixing device, and image forming apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a pressing member that requires a short warm-up time and suppresses deformation of a pressing part pressing a tubular body, and a fixing device and an image forming apparatus including the pressing member.SOLUTION: There is provided a pressing member that is arranged inside a tubular body rotating while in contact with a rotatable rotating member, and has a pressing part 72 that presses the tubular body against the rotating member to form a nip part between the rotating member and the tubular body through which recording media pass, where the pressing part 72 has a plurality of long holes 75 having a longitudinal direction substantially parallel to the rotation shaft direction (arrow X direction) of the tubular body.

Description

  The present invention relates to a pressing member, a fixing device, and an image forming apparatus.

  In an image forming apparatus such as a copying machine or a printer using an electrophotographic system, an unfixed toner image formed on a recording medium such as recording paper is fixed by a fixing device to form an image. As a fixing device used in such an image forming apparatus, for example, a fixing roll and a pressure roll disposed in pressure contact with the fixing roll are provided, and an unfixed portion is provided between the fixing roll and the pressure roll. There is a fixing device that passes a recording medium on which a toner image is formed and heats and pressurizes the unfixed toner image to fix the toner image on the recording medium. Such a fixing device is called a roll nip method, a two-roll method, or a heating roll method.

  In the fixing device, from the viewpoint of saving energy and preventing the user from waiting as much as possible when using the image forming apparatus, the members such as the fixing roll are heated instantaneously until the predetermined fixing temperature is reached. It is desired to reduce this time (hereinafter sometimes referred to as warm-up time).

  Therefore, instead of the above-described two-roll fixing device, for example, a rotatable rotating member, a tubular body rotating in contact with the rotating member (for example, a fixing belt such as an endless belt), and the tubular body A pressing member that is disposed on the inner peripheral surface and has a pressing portion that presses the tubular body against the rotating member and forms a nip portion through which the recording medium passes between the rotating member and the tubular body. There is known a fixing device that employs a so-called belt nip system that allows a recording medium to pass therethrough.

  For example, Patent Document 1 includes a pressure roll that is rotationally driven and has elasticity or flexibility, a heat-resistant endless belt that rotates in contact with the pressure roll, and a flat surface portion. A pressing member that presses the heat-resistant endless belt from the inside and forms a nip portion in a substantially flat shape between the pressure roll and the heat-resistant endless belt, and a heat source disposed on the inner periphery of the heat-resistant endless belt. A fixing device is disclosed which heats a heat-resistant endless belt directly by radiant heat from a heat source and heats it through a pressing member by heat conduction.

  For example, Patent Document 2 discloses a fixing device that performs heating by passing a recording medium through a nip formed between a heating member and a pressure roll that are in pressure contact with each other. And a frame that holds the heater, a metal stay that presses the frame, and is sandwiched between the heater and the pressure roller, and moves at the same speed as the pressure roller while sliding on the heater. A fixing device comprising a heat-resistant film having a low heat capacity, wherein the metal stay is provided with holes of 3% or more with respect to the surface area at regular intervals in the longitudinal direction is disclosed.

  For example, Patent Document 3 discloses a fixing device in which a belt member is used as a fixing-side rotating member or a pressure-side rotating member.

JP 2007-121469 A JP 2010-134094 A JP 2012-118488 A

  An object of the present invention is to provide a pressing member that has a short warm-up time and suppresses deformation of a pressing portion that presses a tubular body, and a fixing device and an image forming apparatus having the pressing member.

  The invention according to claim 1 is arranged inside a tubular body that rotates while being in contact with a rotatable rotating member, and presses the tubular body against the rotating member, so that the rotating member is interposed between the rotating member and the tubular body. A pressing member that forms a nip portion through which the recording medium passes; and the pressing member is a pressing member having a plurality of long holes whose longitudinal direction is substantially parallel to the rotational axis direction of the tubular body. .

  The invention according to claim 2 is the pressing member according to claim 1, wherein the pressing portion is made of metal.

  According to a third aspect of the present invention, the pressing portion includes a first pressing portion disposed on the recording medium inlet side of the nip portion, and a second pressing portion disposed on the recording medium outlet side of the nip portion. And at least the second pressing portion of the first and second pressing portions has a plurality of long holes whose longitudinal direction is a direction substantially parallel to the rotation axis direction of the tubular body. It is a press member of description.

  According to a fourth aspect of the present invention, in any one of the first to third aspects, a lubricant or a sliding material is held in the elongated hole formed in the surface of the pressing portion facing the tubular body. It is a press member of description.

  The invention which concerns on Claim 5 is provided with the sliding member arrange | positioned between the said tubular body and the said press part, and the said slide member coat | covers the surface of the said press part which contacts the said slide member And an anchor part that enters at least a part of the elongated hole formed on the surface of the pressing part, and the covering part and the anchor part are integrated. It is a pressing member given in any 1 paragraph.

  According to a sixth aspect of the present invention, there is provided a rotatable rotating member, a tubular body that rotates while being in contact with the rotating member, the inside of the tubular body, and the tubular body is disposed from an inner peripheral surface of the tubular body. A pressing unit that presses against the rotating member and has a pressing unit that forms a nip through which a recording medium passes between the rotating member and the tubular body, and the pressing unit includes: A fixing device which is the pressing member according to claim 1.

  According to a seventh aspect of the present invention, there is provided an image carrier, a latent image forming unit for forming a latent image on the surface of the image carrier, and developing the latent image using a developer for developing an electrostatic image to form a toner image. The fixing device according to claim 6, further comprising: a developing unit that forms, a transfer unit that transfers the toner image to a recording medium, and a fixing unit that fixes the toner image onto the recording medium. An image forming apparatus.

  According to the invention which concerns on Claim 1, compared with the case where it does not have this structure, the press member by which a warm-up time is short and a deformation | transformation of the press part which presses a tubular body is suppressed is provided.

  According to the invention which concerns on Claim 2, compared with the case where it does not have this structure, the press member by which a warm-up time is short and a deformation | transformation of the press part which presses a tubular body is suppressed is provided.

  According to the invention which concerns on Claim 3, compared with the case where it does not have this structure, the press member by which a warm-up time is short and a deformation | transformation of the press part which presses a tubular body is suppressed is provided.

  According to the invention which concerns on Claim 4, compared with the case where it does not have this structure, the press member by which a warm-up time is short and a deformation | transformation of the press part which presses a tubular body is suppressed is provided.

  According to the invention which concerns on Claim 5, compared with the case where it does not have this structure, the press member by which a warm-up time is short and a deformation | transformation of the press part which presses a tubular body is suppressed is provided.

  According to the sixth aspect of the present invention, there is provided a fixing device in which the warm-up time is short and the deformation of the pressing portion that presses the tubular body is suppressed as compared with the case where this configuration is not provided.

  According to the seventh aspect of the present invention, there is provided an image forming apparatus in which the warm-up time is short and the deformation of the pressing portion that presses the tubular body is suppressed as compared with the case where this configuration is not provided.

1 is a schematic configuration diagram illustrating an example of a configuration of an image forming apparatus according to an embodiment of the present invention. 1 is a schematic configuration diagram illustrating an example of a configuration of a fixing device according to an exemplary embodiment of the present invention. It is a partial schematic perspective view which shows an example of a structure of the press part which concerns on embodiment of this invention. It is a partial schematic perspective view which shows an example of the other structure of the press member which concerns on embodiment of this invention. (A) is a partial model perspective view which shows an example of the other structure of the press member which concerns on embodiment of this invention, (B) is an example of the other structure of the press member which concerns on embodiment of this invention FIG. FIG. 6 is a schematic configuration diagram illustrating another example of the configuration of the fixing device according to the embodiment of the present invention. FIG. 6 is a schematic configuration diagram illustrating another example of the configuration of the fixing device according to the embodiment of the present invention.

  Embodiments of the present invention will be described below. This embodiment is an example for carrying out the present invention, and the present invention is not limited to this embodiment.

  FIG. 1 is a schematic configuration diagram illustrating an example of a configuration of an image forming apparatus according to an embodiment of the present invention. FIG. 2 is a schematic configuration diagram showing an example of the configuration of the fixing device according to the embodiment of the present invention.

  As shown in FIG. 1, the image forming apparatus 10 according to the present embodiment is roughly divided into two configurations of an image forming unit (image forming unit) X and a fixing unit (fixing unit) Y.

  The image forming unit X includes a photosensitive drum (latent image holding member) 1 that rotates in the direction of an arrow D in which a latent image due to a difference in electrostatic potential is formed on the surface by irradiating image-like light after charging. Around this, in order of rotation (arrow D direction), a charging roll (charging means) 2 for charging the surface of the photosensitive drum 1, and image-like light is applied to the photosensitive drum 1 to statically irradiate the surface. An image exposure device (latent image forming means) 3 for forming an electrostatic latent image, and a developer for selectively transferring toner to the latent image formed on the surface of the photosensitive drum 1 to form a toner image (unfixed image). (Developing means) 4, a transfer roll (transfer means) 5 that faces the photosensitive drum 1, generates a transfer bias electric field between the photosensitive drum 1 and a recording paper (recording medium) P, and toner A cleaner (cleaner) for removing toner remaining on the photosensitive drum 1 after image transfer. Grayed member) 6 and is provided.

  For example, the photosensitive drum 1 shown in FIG. 1 is formed by forming a photosensitive layer made of an organic photosensitive material, an amorphous selenium photosensitive material, an amorphous silicon photosensitive material, or the like on the surface of a metal pipe.

  The charging roll 2 shown in FIG. 1 is a roll made of a conductive metal such as stainless steel or aluminum and provided with a high resistance material such as epichlorohydrin rubber on the surface thereof. It is designed to be driven and rotated. When a predetermined voltage is applied, a continuous discharge is generated in the gap in the vicinity of the contact portion between the charging roll 2 and the photosensitive drum 1, and the surface of the photosensitive drum 1 is charged.

  The image exposure device 3 in FIG. 1 generates, for example, a blinking laser beam based on an image signal, and scans this in the main scanning direction of the photosensitive drum 1 by a polygon mirror or the like. An electrostatic latent image is formed on the surface of 1.

  The developing device 4 in FIG. 1 contains, for example, black toner, and an electrostatic latent image formed on the surface of the photosensitive drum 1 by causing a developing roll carrying the toner to approach and face the photosensitive drum 1. The toner is transferred corresponding to the above, and a visualized toner image (unfixed image) is formed (developed).

  The transfer roll 5 in FIG. 1 is composed of, for example, a conductive or semiconductive roll-shaped member, and the toner on the surface of the photosensitive drum 1 by applying a transfer bias voltage to the photosensitive drum 1. The image is transferred to the recording paper P.

  The cleaner 6 in FIG. 1 is, for example, a blade-like member that is pressed against the surface of the photosensitive drum 1, and removes toner remaining on the surface of the photosensitive drum 1. The cleaner 6 may be one that scrapes off toner with a roll-like member or sweeps out toner with a brush, instead of such a blade-like one.

  In the image forming section X having the above-described configuration, the recording paper P is supplied in the direction of arrow C from the upstream side (right side in FIG. 1) to the facing portion between the photosensitive drum 1 and the transfer roll 5. A paper feed mechanism is configured (not shown). A toner image is transferred from the photosensitive drum 1 by the transfer roll 5 to the surface of the recording paper P conveyed to the opposite portion between the photosensitive drum 1 and the transfer roll 5. That is, in the image forming unit X, a toner image (unfixed image) is formed on the surface of the recording paper P.

  The fixing unit Y located on the downstream side of the image forming unit X in the conveyance direction (arrow C direction) of the recording paper P heats and melts the toner image transferred to the surface of the recording paper P, etc. And a fixing device 7 for fixing the toner image.

  2 includes a pressure roll 73 as an example of a rotating member, a fixing belt (for example, an endless belt) 71 as an example of a tubular body that rotates while being in contact with the pressure roll 73, and a fixing belt. The recording paper (recording medium) P is disposed between the pressure roll 73 and the fixing belt 71 by pressing the fixing belt 71 against the pressure roll 73 from the inner peripheral surface of the fixing belt 71. And a pressing member (pressing means) having a pressing portion 72 that forms the nip portion N. Inside the fixing belt 71, for example, a halogen lamp 74 as an example of a heating unit having an output of 500 W or more and 1200 W or less is provided. The pressing portion 72 in FIG. 2 is disposed so as to surround the halogen lamp 74, and the fixing belt 71 in FIG. 2 is provided so as to surround the outer periphery of the pressing portion 72. The recording paper P on which the unfixed toner image is formed is inserted in the direction of arrow C through the nip portion N formed between the fixing belt 71 and the pressure roll 73, and the heat and pressure fixing is performed. To be done.

  The operation of the fixing device 7 shown in FIG. 2 will be described. First, the fixing belt 71 is heated to a predetermined temperature (fixing temperature) by radiant heat from the halogen lamp 74. In this embodiment, the time until the fixing belt 71 reaches the fixing temperature is the warm-up time. Then, the pressure roll 73 is connected to a drive motor (not shown) and rotates in the direction of arrow B. Following this rotation, the fixing belt 71 also rotates in the direction of arrow A. Then, the recording paper P is conveyed by a pressing unit 72 to a nip portion N formed between the fixing belt 71 and the pressure roll 73 by a conveying unit (not shown). When the recording paper P passes through the nip portion N, pressure acting on the nip portion N, heat supplied from the fixing belt 71, and the like are applied to the recording paper P, and an unfixed toner image is formed on the recording paper P. It is fixed. After fixing, the recording paper P passes through the nip portion N, is peeled off from the fixing belt 71, and is discharged from the fixing device 7.

  Next, the press part 72 which comprises the press member of this embodiment is demonstrated. The pressing member used in the fixing device 7 of FIG. 2 has a substantially C-shaped cross section as a whole, and is provided with a flat surface portion H at the apex portion thereof, and has a substantially C-shape opened on the opposite side to the flat surface portion H.

  FIG. 3 is a partial schematic perspective view showing an example of the configuration of the pressing portion according to the embodiment of the present invention. As shown in FIG. 3, the pressing portion 72 has a rotation axis direction of the fixing belt 71 (arrow X, the fixing belt 71 has a rotation axis in the arrow X direction, and the arrow A direction shown in FIG. A plurality of long holes 75 having a direction substantially parallel to the longitudinal direction as a longitudinal direction. Here, in this embodiment, when the longitudinal direction of the long hole 75 is substantially parallel to the rotation axis direction (arrow X) of the fixing belt 71, the inclination of the long hole 75 with respect to the rotation axis direction of the fixing belt 71 is inclined. It is included up to the range of 75 ° or more and −105 ° or less.

  By using the pressing portion 72 of the present embodiment, that is, the pressing portion 72 having a plurality of long holes 75 whose longitudinal direction is substantially parallel to the rotational axis direction of the tubular body (fixing belt 71), the long holes 75 become the heat insulating portions. Therefore, it is considered that the heat of the fixing belt 71 is suppressed from being radiated from the pressing portion 72 as compared with the pressing portion having no hole. More specifically, when the fixing belt 71 heated by the radiant heat of the halogen lamp 74 outside the nip portion N moves to the nip portion N, the heat of the fixing belt 71 is radiated from the pressing portion 72. It is thought that it is suppressed. As a result, the fixing belt 71 is easily heated to a preset temperature (fixing temperature), that is, the heat capacity in heating the fixing belt 71 is suppressed, so that the warm-up time of the fixing device 7 is shortened and energy saving is achieved. It is thought that it will be realized.

  Further, when the tubular body (fixing belt 71) is pressed by the pressing portion 72, stress is applied to the pressing portion 72 mainly in a direction perpendicular to the axial direction of the tubular body (that is, the thickness direction of the pressing portion 72). Conceivable. The pressing portion 72 having a plurality of long holes 75 whose longitudinal direction is substantially parallel to the rotation axis direction of the tubular body (fixing belt 71) is a direction other than the direction substantially parallel to the rotation axis direction of the tubular body (for example, rotation). Compared with a pressing part or the like having a plurality of long holes whose longitudinal direction is perpendicular to the axial direction), the number of holes extending in the thickness direction of the pressing part is small, so the pressing part against stress (load) applied to the pressing part It is thought that deformation is suppressed. Thereby, the pressing force applied to the pressing portion is increased and applied to the nip portion N, compared to the case where the pressing portion having a plurality of long holes whose longitudinal direction is a direction other than the direction substantially parallel to the rotation axis direction of the tubular body is used. Since the load is also increased, it is considered that the fixing property of the toner image and the conveyance property of the recording medium can be stabilized. Note that the load of the nip portion N is a load between the pressing portion 72 and the pressure roll 73. And the load of the nip part N is set, for example to 10 kg or more, Preferably it is 15 kg or more by using the press member which has the press part 72 of this embodiment.

  The size of the long hole 75 provided in the pressing portion 72 is appropriately set according to the load applied to the pressing portion 72, dimensions such as thickness and length, material, and the like. The short diameter (which is an average diameter in the short direction and may hereinafter be referred to as a pore diameter) is, for example, preferably in the range of 0.01 mm to 1 mm, and more preferably in the range of 0.05 mm to 0.5 mm. . Moreover, the average major axis (average diameter in the longitudinal direction) of the long holes 75 is, for example, preferably in the range of 0.5 mm to 50 mm, and more preferably in the range of 2 mm to 20 mm. If the average short diameter of the long holes 75 is less than 0.01 mm or the average long diameter is less than 1 mm, the long holes 75 may not sufficiently function as a heat insulating part, and the average short diameter of the long holes 75 exceeds 1 mm or the average long diameter. If the thickness exceeds 100 mm, the strength of the pressing portion 72 may decrease. The average major axis / average minor axis is preferably in the range of 5 to 500, and more preferably in the range of 15 to 100. If the average major axis / average minor axis is less than 5, curing as a long hole may be thinned, and if it exceeds 500, the production of the present pore member may be expensive and unstable in shape.

  The porosity of the long hole 75 provided in the pressing portion 72 is appropriately set depending on the load applied to the pressing portion 72, dimensions such as thickness and length, material, etc., for example, 5% to 40%. The following range is preferable, and the range of 10% to 30% is more preferable. If the porosity of the long hole 75 is less than 5%, the long hole 75 may not sufficiently function as a heat insulating part, and if the porosity of the long hole 75 exceeds 40%, the strength of the pressing part 72 may decrease. . The porosity of the long hole 75 is the total volume of the long hole 75 with respect to the total volume of the pressing portion 72, the assumed weight when there is no long hole obtained from the specific gravity and outer shape of the material of the pressing member, and the long hole It is measured by dividing the difference from the weight of the main member having the hole by the weight of the main member having the long hole. The plurality of elongated holes 75 provided in the pressing portion 72 are preferably independent independent elongated holes from the viewpoint of the strength of the pressing portion 72, but a part of the plurality of elongated holes 75. It may include a communication-type long hole that communicates.

  The pressing portion 72 is preferably made of a metal material such as iron or aluminum from the viewpoint of durability and heat resistance, and from the viewpoint of thermal conductivity or the like, aluminum, aluminum alloy (for example, A3004 series) or the like. Aluminum-based materials are more preferable. In general, a metal pressing portion is preferable in terms of suppressing deformation of the pressing portion, but heat of the tubular body (fixing belt 71) is easily radiated from the metal pressing portion. However, in this embodiment, even if a metal pressing part is used, it is considered that the long hole 75 acts as a heat insulating part and the heat of the tubular body is suppressed from being radiated from the pressing part.

  The thickness of the pressing portion 72 is not particularly limited because it is entangled with the material strength. For example, the range of 0.5 mm to 10 mm is preferable, and the range of 1.5 mm to 5 mm is more preferable. If the thickness of the pressing portion 72 is less than 0.5 mm, the durability and heat-resistant material strength may be insufficient and may be deformed. If the thickness exceeds 10 mm, the heat capacity may be large and it may take too much warm-up time.

  Next, an example of the manufacturing method of the press part 72 is demonstrated. The pressing portion 72 having the plurality of long holes 75 is manufactured by, for example, a mold casting method, a continuous zone melting method, a gas compound pyrolysis manufacturing method, or the like.

  The mold casting method is, for example, a melting portion and a solidifying portion of a target material provided in a high-pressure container, and melting the target material (for example, metal) in the melting portion by high-frequency heating or the like, and predetermining in the solidifying portion. The gas is dissolved in the target material melted in the gas at a high pressure, and the bottom of the container is cast into a mold having a copper disk cooled by a water-cooled chiller or the like to solidify the target material in one direction from below to above. It is. For example, when the target material solidifies, the gas dissolved in the target material becomes the aforementioned long hole 75, and the longitudinal direction of the long hole 75 in the solidified target material is controlled in the solidification direction. The high-pressure container provided with the melting part and the solidification part is not particularly specified as long as it can withstand a desired high pressure and temperature.

  The continuous zone melting method is, for example, a method in which a rod-shaped target material (for example, metal) is partially dissolved by a high-frequency heating coil under high-pressure gas, and the gas is absorbed into the melting portion and continuously moved. For example, the gas absorbed in the melted portion becomes the aforementioned long hole 75, and the direction of the long hole 75 in the target material in the longitudinal direction is controlled by the moving direction. Note that the continuum melting method can obtain the pressing portion 72 having a more uniform pore diameter and porosity than the above-described mold casting method, even with a material having a lower thermal conductivity than aluminum such as stainless steel or an intermetallic compound.

  The gas compound pyrolysis method is, for example, a method in which a pyrolysis compound such as hydride or nitride is added to a molten target material (molten metal) and solidified in one direction with a mold. For example, the long hole 75 is formed by the thermal decomposition of the thermal decomposition compound in the molten metal, and the longitudinal direction of the long hole 75 is controlled in the solidification direction.

From the viewpoint of controlling the pore diameter and porosity of the pressing portion 72, it is preferable to use a gas compound pyrolysis method and a mold casting method in combination. A predetermined amount of pyrolytic compound (eg, TiH ₂ powder pellets) is set on the bottom of the mold, and the target material (eg, 200 g of copper) is heated in a crucible by high-frequency heating in an argon atmosphere of, for example, 0.05 MPa to 0.2 MPa. This is a method of casting the target material dissolved in the above mold with the bottom portion being water-cooled and solidifying in one direction.

  FIG. 4 is a partial schematic perspective view showing an example of another configuration of the pressing member according to the embodiment of the present invention. As shown in FIG. 4, the pressing member has the aforementioned pressing portion 72 and a long hole 75 formed in the surface S of the pressing portion 72 facing the fixing belt 71, and a lubricant 76 is placed in the long hole 75. Is retained. The lubricant 76 only needs to be held in the long hole 75 formed on the surface (for example, the flat surface portion H) of the pressing portion 72 that contacts at least the fixing belt 71. In the present embodiment, a sliding material may be used instead of the lubricant 76. As described above, when the lubricant 76 or the sliding material is held in the long hole 75 formed on the surface of the pressing portion 72 facing the fixing belt 71, the fixing belt 71 and the pressing portion 72 slide. Since the lubricant 76 or the sliding material oozes out from the long hole 75, the friction between the pressing portion 72 and the fixing belt 71 can be suppressed as compared with the case where the lubricant 76 or the sliding material is not held in the long hole 75. it is conceivable that. As a result, it is considered that the driving torque for rotating the fixing belt 71 or the pressure roll 73 is suppressed, and the belt slip phenomenon at the time of starting the rotation of the fixing belt 71 is suppressed.

  As a method for holding the lubricant 76 or the sliding material in the long hole 75 formed on the surface of the pressing portion 72 on the fixing belt 71 side, for example, the sliding material is applied and baked, or in the sliding material dispersion liquid. For example, a method of immersing the pressing member and impregnating the long hole may be used.

  The lubricant 76 is not particularly limited as long as it imparts lubricity to the surface of the pressing portion 72. For example, amino-modified silicone oil, dimethyl silicone oil, mercapto-modified silicone oil, and antioxidant are contained. Examples thereof include silicone oils such as hindered amine oils that are amino-modified silicone oils, fluorine grease, and the like. The sliding material is not particularly limited as long as it provides slidability to the surface of the pressing portion 72. For example, thermosetting polyimide, thermoplastic polyimide, polyamide, polyamideimide, silicone Examples thereof include low friction resins such as elastomer (silicone resin), fluororesin, and fluorine-containing elastomer.

  FIG. 5A is a partial schematic perspective view showing an example of another configuration of the pressing member according to the embodiment of the present invention, and FIG. 5B shows the other of the pressing member according to the embodiment of the present invention. It is a partial schematic cross section which shows an example of the structure. As shown in FIGS. 5A and 5B, the pressing member is a sliding member (sliding sheet) 77 disposed on the surface of the pressing portion 72 facing the fixing belt 71 in addition to the pressing portion 72 described above. It has. That is, the sliding member 77 shown in FIG. 5 is disposed between the pressing portion 72 and the inner peripheral surface of the fixing belt 71. The sliding member 77 is formed in at least a part of a cover portion 78 that covers the surface of the pressing portion 72 that contacts the sliding member 77 and a long hole 75 that is formed on the surface of the pressing portion 72 that contacts the sliding member 77. The cover portion 78 and the anchor portion 79 are integrated with each other. For example, the sliding member 77 in which the covering portion 78 and the anchor portion 79 are integrated is obtained by applying a material constituting the sliding member 77 to the surface of the pressing portion 72 and heating the material. By using such a sliding member 77 having the covering portion 78 and the anchor portion 79, the sliding member 77 and the pressing portion 72 are compared with the case where a covering material not having the anchor portion 79 is used. Since the adhesiveness is improved, it is considered that when the fixing belt 71 and the sliding member 77 slide, the positional deviation of the sliding member 77 can be suppressed.

  The material constituting the sliding member 77 is not particularly limited as long as it imparts slidability to the surface of the pressing portion 72. For example, thermosetting polyimide, thermoplastic polyimide, polyamide, polyamide Examples thereof include low-friction resins such as imide, silicone elastomer (silicone resin), fluororesin, and fluorine-containing elastomer.

  Next, another configuration of the fixing device 7 of FIG. 2 will be described. The halogen lamp 74 in FIG. 2 is, for example, a glass-made cylindrical lamp tube with a filament arranged substantially at the center thereof, and a heat semi-shielding member such as white ceramics in a partial region of the peripheral surface of the lamp tube. Is coated. The range of this region is preferably, for example, a range of a central angle of 180 ° or more and 270 ° or less with a filament as a base point (center). By providing the heat semi-shielding member in this range, for example, the flat surface portion H of the pressing portion 72 corresponding to the nip portion N is easily heated, and the fixing belt 71 and the portions other than the flat surface portion H of the pressing portion 72 are excessive. Heating is prevented.

  The fixing belt 71 shown in FIG. 2 has, for example, a two-layer structure including a heat absorbing layer and a release layer disposed on the heat absorption layer, and the release layer is in contact with the pressure roll 73. It has become. The release layer is, for example, a layer having a thickness in the range of 1 μm to 40 μm. From the viewpoint of releasability and durability, for example, fluorine such as polyimide resin, perfluoroalkoxy resin, perfluoropolytetraethylene resin, etc. It is comprised from resin, such as resin. The heat absorbing layer is, for example, a layer having a thickness in the range of 30 μm or more and 100 μm or less, and a resin such as a polyimide resin, a fluoro resin such as a perfluoroalkoxy resin or a perfluoropolytetraethylene resin, and a heat such as carbon black It consists of a mixture of conductive fillers. The fixing belt 71 is a heat absorbing property that has been subjected to a process of improving heat absorption by mixing a heat conductive filler or the like in order to make the fixing belt 71 easily absorb the radiant heat from the halogen lamp 74. It is preferable to include a layer. Further, the fixing belt 71 is not limited to the two-layer structure, and may be, for example, a single-layer structure having only a heat-absorbing layer, or having both a release property and a heat-absorbing property. The outer diameter of the fixing belt 71 is appropriately set according to the size of the fixing device 7 or the like, and is set to, for example, φ15 mm or more and φ200 mm or less.

  The pressure roll 73 shown in FIG. 2 is preferably a so-called soft roll including a metal core and an elastic layer provided on the outer periphery of the core. The elastic layer is made of, for example, silicone rubber or a foam thereof from the viewpoint of heat resistance, elasticity, and the like. In this embodiment, due to the pressing force from the fixing belt 71 side, the elastic layer of the pressure roll 73 is recessed at the nip portion N, and the shape of the nip portion N is affected by the flat surface portion H of the pressing portion 72, so It is flat. As described above, the shape of the nip portion N becomes substantially flat due to the influence of the flat surface portion H of the pressing portion 72. For example, the conveyance speeds of the fixing belt 71 and the pressure roll 73 become substantially the same, and recording is performed. It is considered that the occurrence of paper wrinkles and curling of the paper P is suppressed. The pressure roll 73 is not necessarily provided with an elastic layer, but the surface property of the pressure roll 73 is desirably elastic or flexible so as to be deformed into a shape corresponding to the nip shape to be formed.

  FIG. 6 is a schematic configuration diagram showing another example of the configuration of the fixing device according to the embodiment of the present invention. The fixing device 60 shown in FIG. 6 includes a fixing roller 61 as an example of a rotating member, a pressure belt 62 as an example of a tubular body, and a pressing member 64, and the main part is configured on the pressure side. Is a free belt nip type fixing device using The pressing member 64 includes a first pressing portion 64 a and a second pressing portion 64 b that press the pressure belt 62 against the fixing roll 61, and a sliding member 68. Inside the fixing roll 61, heating means for heating and fixing the toner image on the recording paper P, for example, a heater lamp 66 is provided.

  The operation of the fixing device 60 shown in FIG. 6 will be described. First, the fixing roll 61 is connected to a drive motor (not shown) and rotates in the direction of arrow C, and the pressure belt 62 also rotates following this rotation. The fixing roll 61 is heated to a predetermined temperature (fixing temperature) by the radiant heat from the heater lamp 66. In the present embodiment, the time until the fixing roll 61 reaches the fixing temperature is the warm-up time. Then, the recording paper P is transported from the fixing device transport section 56 to a nip portion N formed between the fixing roll 61 and the pressure belt 62. When the recording paper P passes through the nip portion N, pressure acting on the nip portion N, heat supplied from the fixing roll 61, and the like are applied to the recording paper P, and an unfixed toner image is formed on the recording paper P. It is fixed. After fixing, the recording paper P passes through the nip portion N, is peeled off from the fixing roll 61 by a peeling member 40 described later, and is discharged from the fixing device 60.

  Next, the pressing member 64 shown in FIG. 6 will be described. The first pressing portion 64 a and the second pressing portion 64 b constituting the pressing member 64 shown in FIG. 6 are supported by a holder 65 made of metal or the like inside the pressure belt 62. The first pressing portion 64 a and the second pressing portion 64 b press the pressure belt 62 against the fixing roll 61 from the inner peripheral surface of the pressure belt 62, and record between the pressure belt 62 and the fixing roll 61. A nip portion N through which the paper (recording medium) P passes is formed. The first pressing portion 64a is disposed on the recording medium inlet side (recording medium upstream side) of the nip portion N, and a wide nip portion N, for example, is secured by the first pressing portion 64a. The second pressing portion 64b is disposed on the recording medium exit side (recording medium downstream side) of the nip portion N, and the surface of the fixing roll 61 is locally pressed by the second pressing portion 64b, for example. A down curl is formed.

  Usually, the second pressing portion 64b disposed on the recording medium outlet side of the nip portion N is disposed on the recording medium inlet side of the nip portion N, for example, in order to facilitate the separation of the recording paper P from the fixing roll 61. It is desirable to apply a load greater than or equal to the load applied to the first pressing portion 64a. Therefore, it is considered that the stress applied to the second pressing portion 64b in the thickness direction of the pressing portion is likely to be higher than the first pressing portion 64a. Further, as described above, it is desirable to suppress heat dissipation from the pressing portion from the viewpoint of shortening the warm-up time. Therefore, in the present embodiment, among the first pressing portion 64a and the second pressing portion 64b, at least the second pressing portion 64b has a longitudinal direction as a direction substantially parallel to the rotation axis direction of the pressure belt 62 (tubular body). It is preferable that the first pressing portion 64a and the second pressing portion 64b have a long hole whose longitudinal direction is substantially parallel to the rotation axis direction of the pressure belt 62 (tubular body). It is more preferable to have multiple. In addition, since this long hole is as above-mentioned, description is abbreviate | omitted. It is considered that the warm-up time of the fixing device 60 is shortened by at least providing the aforementioned long hole in the second pressing portion 64b, and at least the deformation of the second pressing portion 64b is suppressed.

  For the first pressing portion 64a of the pressing member 64, for example, an elastic body such as silicone rubber or fluorine-containing rubber, a leaf spring, or the like is used. The second pressing portion 64b of the pressing member 64 is formed of a heat-resistant resin such as PPS, polyimide, polyester, or polyamide, or a metal such as iron, aluminum, or SUS.

  The pressing member 64 shown in FIG. 6 includes a sliding member 68. The sliding member 68 is interposed between the first and second pressing portions (64a, 64b) and the pressure belt 62, and at least a part of the sliding member 68 upstream from the nip portion N is not shown. These are fixed to the holder 65 by a fixing member or the like. The sliding member 68 shown in FIG. 6 has the same configuration as the sliding member 77 shown in FIG. From the viewpoint of the slidability of the first and second pressing portions (64a, 64b) and the like, it is preferable to install the sliding member 68, but the sliding member 68 may not be provided. Further, the lubricant or the sliding member may be held in a long hole formed in the surface of the second pressing portion 64b (and the surface of the first pressing portion 64a) facing the pressure belt 62.

  Next, another configuration of the fixing device 60 shown in FIG. 6 will be described.

  A fixing roll 61 shown in FIG. 6 is a cylindrical roll configured by laminating an elastic body layer 612 and a release layer 613 around a core (cylindrical cored bar) 611 made of metal or the like, and is rotatable. It is supported.

  The core 611 of the fixing roll 61 is, for example, iron, aluminum (for example, A-5052 material), SUS, copper or other metal or alloy, ceramics, FRM, or the like in terms of mechanical strength and heat conductivity.

  The material of the elastic body layer 612 of the fixing roll 61 may be appropriately selected from conventionally known materials. For example, a silicone elastomer (hereinafter sometimes referred to as silicone rubber), a fluorine-containing elastomer (hereinafter referred to as “silicone rubber”). And may be called fluorine-containing rubber).

  Further, the material of the release layer 613 of the fixing roll 61 is desirably a material that exhibits an appropriate release property with respect to the toner image P, and examples thereof include fluorine rubber, silicone rubber, and fluorine resin.

  Further, around the fixing roll 61, a peeling member 40 for peeling the recording paper P after fixing and a temperature sensor 69 for controlling the temperature of the roll surface are provided. The peeling member 40 includes a peeling baffle 41 that is disposed in a direction facing the rotation direction C of the fixing roll 61 (counter direction) in a state of being close to the fixing roll 61, and a holder 42 that holds the peeling baffle 41. ing.

  In the present embodiment, the heater lamp 66 is used as the heating unit. However, the heating unit is not limited to the type in which the fixing roll 61 is internally heated as long as the nip portion N is heated. And the like that heat externally.

  The pressure belt 62 shown in FIG. 6 is rotatably supported by a pressing member 64 and a belt traveling guide 63 disposed inside the pressure belt 62, and is driven to rotate by receiving a driving force from the fixing roll 61. The Examples of the pressure belt 62 of the present embodiment include a belt member such as a seamless endless belt whose original shape is formed in a cylindrical shape and a belt having a seam.

  There is no restriction | limiting in particular about the shape, a magnitude | size, etc. as the pressure belt 62, According to the objective, it selects suitably from conventionally well-known things. The structure of the pressure belt 62 may be a single layer structure or a multilayer structure. Examples of the pressure belt 62 having a multilayer structure include those having a base layer and a release layer. Examples of the material of the base layer of the pressure belt 62 include thermosetting polyimide, thermoplastic polyimide, polyamide, and polyamideimide. Examples of the material for the release layer include fluororubber, silicone rubber, and fluororesin.

  A lubricant application member 67 is disposed on a holder 65 provided in the pressure belt 62. The lubricant application member 67 is disposed so as to contact the inner peripheral surface of the pressure belt 62, and the lubricant is supplied from the lubricant application member 67 to the inner peripheral surface of the pressure belt 62.

  Lubricants are, for example, amino-modified silicone oil, dimethyl silicone oil, mercapto-modified silicone oil, amino-modified silicone containing antioxidants, from the viewpoints of lubricity, kinematic viscosity as an index of lubricity, heat resistance, volatility, etc. A silicone oil such as a hindered amine oil that is an oil is preferable, and an amino-modified silicone oil is more preferable from the viewpoint of wettability. In addition, methylphenyl silicone oil is also preferable from the viewpoint of superior performance due to heat resistance. In view of heat resistance, hindered amine oil is preferable.

  FIG. 7 is a schematic configuration diagram illustrating another example of the configuration of the fixing device according to the embodiment of the present invention. 7 includes a fixing belt 51 as an example of a tubular body, a pressure roll 52 as an example of a rotating member, and an inner side of the fixing belt 51, and presses the fixing belt 51 against the pressure roll 52. This is a so-called IH belt type fixing device in which a main part is configured by a pressing member having a pressing portion 53 and a magnetic field generating unit 80 disposed on the outer peripheral surface of the fixing belt 51 and generating heat from the fixing belt 51.

  The operation of the fixing device 50 shown in FIG. 7 will be described. The pressure roll 52 is rotated in the direction of arrow C by a drive motor (not shown), and accordingly, the fixing belt 51 is rotated in the direction of arrow C ′. Further, the fixing belt 51 is heated to a predetermined temperature (fixing temperature) by the electromagnetic induction effect of the alternating magnetic flux generated by the magnetic field generation unit 80. The heated fixing belt 51 moves to the nip portion N with the pressure roll 52. The recording paper (recording medium) P on which the unfixed toner image is formed is conveyed from the fixing device conveyance unit 44 to the nip N formed between the fixing belt 51 and the pressure roll 52. When the recording paper P passes through the nip portion N, the unfixed toner image is heated by the fixing belt 51 and fixed on the surface of the recording paper P. The recording paper P on which the image is formed in this manner is discharged from the fixing device 50 by a conveyance unit (not shown).

  The pressing member shown in FIG. 7 includes a pressing portion 53 and a sliding member 55. The pressing portion 53 is supported by a metal holder 57 inside the fixing belt 51. The pressing portion 53 is disposed so as to face the pressure roll 52 via the fixing belt 51, and presses the pressure roll 52 against the fixing belt 51 from the inner peripheral surface of the fixing belt 51 to add to the fixing belt 51. A nip portion N through which recording paper (recording medium) P passes is formed between the pressure roll 52.

  The pressing portion 53 shown in FIG. 7 has a plurality of long holes whose longitudinal direction is a direction substantially parallel to the rotation axis direction of the fixing belt 51 (tubular body). In addition, since this long hole is as above-mentioned, description is abbreviate | omitted. Also in the present embodiment, it is considered that by providing the above-described long hole in the pressing portion 53, the warm-up time of the fixing device 60 is shortened and the deformation of the pressing portion 53 is suppressed. The pressing portion 53 is formed of, for example, a heat-resistant resin such as PPS, polyimide, polyester, or polyamide, or a metal such as iron, aluminum, or SUS.

  The sliding member 55 shown in FIG. 7 is interposed between the pressing portion 53 and the fixing belt 51, and both end portions of the sliding member 55 are fixed to the holder 57 by a fixing member (not shown). The sliding member 55 shown in FIG. 7 has the same configuration as the sliding member 77 shown in FIG. Although it is preferable to install the sliding member 55 from the viewpoint of the slidability of the pressing portion 53, the sliding member 55 may not be provided. Further, the lubricant or the sliding member may be held in a long hole formed in the surface of the pressing portion 53 facing the fixing belt 51.

  Next, another configuration of the fixing device 50 shown in FIG. 7 will be described.

  The fixing belt 51 is rotatably supported by a pressing portion 53 disposed on the inner peripheral side and a belt guide member 54. The material of the belt guide member 54 is, for example, a heat resistant resin such as tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer (PFA).

  The fixing belt 51 is, for example, an annular belt and has a layered structure in which a base material layer, a heat generating layer, an elastic layer, a release layer, and the like are laminated in order from the inside, although explanation in the drawing is omitted.

  The base material layer is formed of, for example, a resin having high heat resistance having a thickness of 10 μm to 100 μm. Examples of the resin include polyester, polyethylene terephthalate, polyimide, polyamide, and the like.

  The heat generating layer generates heat by the electromagnetic induction action of the alternating magnetic flux generated by the magnetic field generating unit 80. Examples of the material of the heat generating layer include metals such as cobalt, iron, nickel, and metal materials such as alloys thereof.

  The elastic layer is formed of, for example, silicone rubber, fluororubber, fluorosilicone rubber, or the like, which is a material having a heat resistance and a thermal conductivity of 10 μm to 500 μm.

  The material of the release layer is, for example, a fluororesin such as tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer (PFA), polytetrafluoroethylene (PTFE), tetrafluoroethylene-hexafluoropropylene copolymer (FEP), Silicone resin, silicone rubber, fluorine rubber and the like can be mentioned.

  The pressure roll 52 is configured by laminating an elastic body layer 522 and a release layer 523 around a cored bar 521 such as iron, aluminum, or SUS. Examples of the material of the elastic layer 522 include silicone sponge, silicone rubber, and fluororubber. Examples of the material of the release layer 523 include PFA (tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer), PTFE (polytetrafluoroethylene), FEP (tetrafluoroethylene-hexafluoropropylene copolymer), and those. Examples thereof include heat-resistant resins such as fluororesins that are composite materials.

  On the downstream side of the nip portion N, a peeling member 40 that includes a peeling baffle 41 that is disposed close to the fixing belt 51 in a direction opposite to the rotation direction of the fixing belt 51 and a holder 42 that holds the peeling baffle 41. Is provided. The recording paper P is peeled from the fixing belt 51 by the peeling member 40.

  The holder 57 is provided with a lubricant application member 67. The lubricant application member 67 is disposed so as to be in contact with the inner peripheral surface of the fixing belt 51, and the lubricant is supplied from the lubricant application member 67 to the inner peripheral surface of the fixing belt 51.

  The lubricant supplied by the lubricant application member 67 is, for example, a liquid oil such as silicone oil such as dimethyl silicone oil, amino-modified silicone oil, carboxy-modified silicone oil, silanol-modified silicone oil, sulfonic acid-modified silicone oil, or fluorine oil. Further, a grease obtained by mixing a solid substance and a liquid, and a combination of these may be used.

  The magnetic field generation unit 80 includes an excitation coil 81 that generates a magnetic field, a coil support member 82 that holds the excitation coil 81, and an excitation circuit 83 that supplies current to the excitation coil 81. The magnetic field generating unit 80 has a cross-sectional shape that is curved along the shape of the fixing belt 51, and is installed with a predetermined gap from the outer peripheral surface of the fixing belt 51.

  As the exciting coil 81, for example, a coil in which litz wires obtained by bundling mutually insulated copper wires are wound in a closed loop shape such as an oval shape, an elliptical shape, or a rectangular shape is used. An alternating current having a predetermined frequency is applied to the exciting coil 81 by the exciting circuit 83, and an alternating magnetic field is generated around the exciting coil 81.

  As the material of the coil support member 82, for example, a heat resistant resin such as heat resistant glass or polycarbonate is used. Further, a ferromagnetic material such as ferrite may be disposed at the center of the coil support member 82.

  Although the embodiments of the present invention have been described above, the present invention is not construed as being limited to the above-described embodiments, and various modifications, changes, and improvements can be made, and a range that satisfies the requirements of the present invention. Needless to say, this is feasible.

  Hereinafter, although an example and a comparative example are given and the present invention is explained more concretely in detail, the present invention is not limited to the following examples.

Example 1
Using an image forming apparatus DocuPrint P350D manufactured by Fuji Xerox Co., Ltd., the test was performed under the following conditions. The fixing device mounted on the image forming apparatus is the fixing device shown in FIG. 2 and has a specific configuration as follows.

  The pressure roll has an outer diameter in which an outer peripheral surface of a cylindrical aluminum core is coated with a foamed sponge having a thickness of 4 mm as an elastic layer, and a fluororesin is coated as a release layer on the surface of the elastic layer. It is a 28 mm roll. The fixing belt uses a polyimide resin containing 5% by mass of carbon black as a base material (thickness 70 μm, outer diameter 30 mm), and a fluororesin layer as a release layer is formed on the outer peripheral surface of the base material with a thickness of 25 μm. It is coated. Inside the fixing belt, an 850 w halogen lamp was disposed as a heating source.

  Aluminum was used as the material constituting the pressing portion, and the pressing portion was produced by using the above-described gas compound pyrolysis method and mold casting method in combination. The size of the long hole formed in the pressing portion produced by the above method and conditions, that is, the long hole whose longitudinal direction is substantially parallel to the rotation axis direction of the fixing belt, is a microscope device (VHX, manufactured by Keyence Corporation). -1000 type), the average minor axis was 0.2 mm and the average major axis was 10 mm (average major axis / average). Minor axis = 50). The porosity of the long holes was 15%. The size of the used pressing part was 250 mm in length (longitudinal direction), 7 mm in width (short direction), and 3 mm in thickness. In Example 1, since the longitudinal direction of the pressing portion corresponds to the rotation axis direction of the fixing belt, the longitudinal direction of the long hole formed in the pressing portion is substantially parallel to the longitudinal direction of the pressing portion. It was confirmed by the same method as above. As a result, since the longitudinal direction of the long hole was in the range of 85 ° to 95 ° with respect to the longitudinal direction of the pressing portion, the longitudinal direction of the long hole is the rotation axis direction of the fixing belt (the pressing portion in Example 1). It can be said that it is substantially parallel to the longitudinal direction of the.

  As a sliding member disposed on the surface of the pressing portion on the fixing belt side, a fluororesin sheet having a thickness of 20 μm was used. The sliding member is manufactured by applying a fluororesin to the surface of the pressing portion on the fixing belt side, and is formed on the surface of the pressing portion and the covering portion that covers the surface of the pressing portion as described above. And an anchor portion that enters at least a part of the long hole.

  In the fixing device of Example 1, the length from the upstream side to the downstream side of the flat surface portion H of the pressing portion is set to 7 mm, and the load between the pressing portion and the pressure roll (that is, the load of the nip portion N) is set to 15 kg. Then, the fixing temperature is controlled at 155 ° C. (measured by a temperature sensor placed near the pressing portion on the plain paper entrance side), and the plain paper (Fuji Fuji) printed at the image forming unit of the image forming apparatus at a speed of 200 mm / sec. J paper A4 manufactured by Xerox Co., Ltd. was set to the conditions for passing paper.

  In Example 1, before passing the plain paper, the time from the start of heating by the halogen lamp until the temperature of the fixing belt reached 155 ° C., which is the fixing temperature, was measured and found to be 14 seconds. . The temperature of the fixing belt was a value measured by the above-described temperature sensor, and the temperature of the fixing belt before heating with the halogen lamp was 20 ° C.

  Further, when the deformation of the pressing portion was visually observed at a stage where a load of 15 kg (nip load) was applied between the pressing portion and the pressure roll, no deformation of the pressing portion was confirmed. Under the above conditions, 10,000 sheets of plain paper (J paper A4 manufactured by Fuji Xerox Co., Ltd.) printed by the image forming unit of the image forming apparatus was passed. The following was good fixing property. Such good fixability is considered to be because the deformation of the pressing portion was suppressed and the flatness of the nip portion N was ensured for a nip load of 15 kg. Further, no slip phenomenon of the fixing belt was observed while 10,000 sheets of plain paper were passed. This is considered because the sliding torque of the fixing belt is suppressed by the sliding member disposed on the surface of the pressing portion on the fixing belt side.

(Example 2)
In Example 2, it tested on the conditions similar to Example 1 except not using a sliding member.

  In Example 2, the time from when the heating by the halogen lamp was started to the time when the temperature of the fixing belt reached 155 ° C., which is the fixing temperature, was 13 seconds before passing the plain paper. . The temperature of the fixing belt was a value measured by the above-described temperature sensor, and the temperature of the fixing belt before heating with the halogen lamp was 20 ° C.

  Further, when the deformation of the pressing portion was visually observed at a stage where a load of 15 kg (nip load) was applied between the pressing portion and the pressure roll, no deformation of the pressing portion was confirmed. Under the above conditions, 10,000 sheets of plain paper (J paper A4 manufactured by Fuji Xerox Co., Ltd.) printed by the image forming unit of the image forming apparatus was passed. The following fixity was the same as in Example 1. However, a fixing belt slip phenomenon occurred immediately after the start of passing plain paper. This is thought to be because the sliding torque of the fixing belt is higher than that of Example 1 in which the sliding member is arranged because the sliding member is not arranged on the surface of the pressing portion on the fixing belt side.

(Example 3)
In Example 3, the test was conducted under the same conditions as in Example 2 except that PTFE was retained by a method of dipping in a PTFE dispersion, baking, and impregnating into a long hole formed on the surface of the pressing portion on the fixing belt side.

  In Example 3, the time from the start of heating by the halogen lamp before passing the plain paper until the temperature of the fixing belt reached 155 ° C., which is the fixing temperature, was measured and found to be 16 seconds. . The temperature of the fixing belt was a value measured by the above-described temperature sensor, and the temperature of the fixing belt before heating with the halogen lamp was 20 ° C.

  Further, when the deformation of the pressing portion was visually observed at a stage where a load of 15 kg (nip load) was applied between the pressing portion and the pressure roll, no deformation of the pressing portion was confirmed. Under the above conditions, 10,000 sheets of plain paper (J paper A4 manufactured by Fuji Xerox Co., Ltd.) printed by the image forming unit of the image forming apparatus was passed. As a result, no fixed image misalignment and paper curl occurred, and the curl was 5 mm. The following fixity was the same as in Example 1. While 10,000 sheets of plain paper were passed, no slip phenomenon of the fixing belt was observed. This is presumably because the sliding torque of the fixing belt is suppressed by PTFE held in the long hole formed on the surface of the pressing portion on the fixing belt side.

Example 4
In Example 4, using the gas compound pyrolysis method and the mold casting method described above, a pressing portion having an average minor axis of 0.4 mm, an average major axis of 15 mm, and a porosity of 25% of the major hole was obtained. The test was performed under the same conditions as in Example 3 except for the production.

  In Example 4, the time from the start of heating by the halogen lamp before passing the plain paper to the time when the temperature of the fixing belt reached 155 ° C., which is the fixing temperature, was measured and found to be 14 seconds. . The temperature of the fixing belt was a value measured by the above-described temperature sensor, and the temperature of the fixing belt before heating with the halogen lamp was 20 ° C.

  Further, when the deformation of the pressing portion was visually observed at a stage where a load of 15 kg (nip load) was applied between the pressing portion and the pressure roll, no deformation of the pressing portion was confirmed. Under the above conditions, 10,000 sheets of plain paper (J paper A4 manufactured by Fuji Xerox Co., Ltd.) printed by the image forming unit of the image forming apparatus was passed. The following fixity was the same as in Example 1. While 10,000 sheets of plain paper were passed, no slip phenomenon of the fixing belt was observed. This is presumably because the sliding torque of the fixing belt is suppressed by PTFE held in the long hole formed on the surface of the pressing portion on the fixing belt side.

(Comparative Example 1)
In the comparative example 1, it tested on the conditions similar to Example 1 except having used the aluminum material which does not have a pore for a press part.

  In Comparative Example 1, the time from the start of heating by the halogen lamp before passing the plain paper until the temperature of the fixing belt reached 155 ° C., which is the fixing temperature, was 22 seconds. The results were slower than those of Examples 1 to 4. The temperature of the fixing belt was a value measured by the above-described temperature sensor, and the temperature of the fixing belt before heating with the halogen lamp was 20 ° C.

  From this result, it is possible to fix by using a pressing portion having a plurality of long holes whose longitudinal direction is substantially parallel to the rotation axis direction of the fixing belt, as compared with a case where a pressing portion having no pores is used. It is considered that the warm-up time (time to reach a predetermined fixing temperature) is shortened because the heat of the belt is hardly dissipated from the pressing portion and the temperature of the fixing belt easily rises.

  In Comparative Example 1, when the deformation of the pressing portion was visually observed at the stage where a load of 15 kg (nip load) was applied between the pressing portion and the pressure roll, the deformation of the pressing portion was not confirmed. Under the above conditions, 10,000 sheets of plain paper (J paper A4 manufactured by Fuji Xerox Co., Ltd.) printed by the image forming unit of the image forming apparatus was passed. As a result, no fixed image misalignment and paper curl occurred, and curl was 5 mm. The following fixity was the same as in Example 1. While 10,000 sheets of plain paper were passed, the fixing belt slip phenomenon was not observed as in Example 1.

(Comparative Example 2)
In Comparative Example 2, a plurality of long holes whose longitudinal direction is a direction perpendicular to the rotation axis direction of the fixing belt (the vertical direction is the thickness direction of the aluminum material) are formed in the aluminum material having no pores. The test was performed under the same conditions as in Example 1 except that the formed part was used as the pressing part. The length (longitudinal direction) of the long holes of Comparative Example 2 was 5 mm, and the distance between the long holes was 10 mm.

  In Comparative Example 2, as a result of measuring the time from the start of heating by the halogen lamp before passing the plain paper until the temperature of the fixing belt reached 155 ° C. which is the fixing temperature, it was 14 seconds, The result was almost the same as in Example 1. The temperature of the fixing belt was a value measured by the above-described temperature sensor, and the temperature of the fixing belt before heating with the halogen lamp was 20 ° C. Comparative Example 2 differs from Example 1 in the longitudinal direction of the long holes, but has a long hole, so that the heat of the fixing belt is hardly dissipated from the pressing portion as in Example 1, and It is considered that the warm-up time was similar.

  In Comparative Example 2, the deformation of the pressing portion was confirmed by visually observing the deformation of the pressing portion when a 15 kg load (nip load) was applied between the pressing portion and the pressure roll. Under the above conditions, as a result of passing 100 sheets of plain paper (J paper A4 manufactured by Fuji Xerox Co., Ltd.) printed by the image forming unit of the image forming apparatus, fixing image misalignment and paper wrinkles occurred at the center of the plain paper. The curl was also 20 mm or more. From this result, the pressing portion having a long hole whose longitudinal direction is substantially parallel to the rotation axis direction of the fixing belt is longer in the direction other than the direction substantially parallel to the rotation axis direction of the fixing belt. It is considered that the pressing portion having a hole suppresses the deformation of the pressing portion with respect to the nip load, and exhibits good fixability.

(Comparative Example 3)
In Comparative Example 3, the test was performed under the same conditions as in Example 1 except that a plurality of circular holes having a diameter of 2 mm were formed as the pressing portion in an aluminum material having no pores. The interval between the holes in Comparative Example 3 was 8 mm.

  In Comparative Example 3, the time from the start of heating with the halogen lamp before passing the plain paper to the time when the temperature of the fixing belt reached 155 ° C., which is the fixing temperature, was 14 seconds. The result was almost the same as in Example 1. The temperature of the fixing belt was a value measured by the above-described temperature sensor, and the temperature of the fixing belt before heating with the halogen lamp was 20 ° C.

  In Comparative Example 3, when the load of 15 kg (nip load) was applied between the pressing portion and the pressure roll, the deformation of the pressing portion was observed visually, and the deformation of the pressing portion was confirmed. Under the above conditions, as a result of passing 100 sheets of plain paper (J paper A4 manufactured by Fuji Xerox Co., Ltd.) printed by the image forming unit of the image forming apparatus, fixing image misalignment and paper wrinkles occurred at the center of the plain paper. The curl was also 20 mm or more. From this result, the pressing portion having a long hole whose longitudinal direction is substantially parallel to the rotation axis direction of the fixing belt can suppress the deformation of the pressing portion with respect to the nip load than the pressing portion having a spherical hole, It is considered that good fixability is exhibited.

  DESCRIPTION OF SYMBOLS 1 Photosensitive drum, 2 Charging roll, 3 Image exposure device, 4 Developer, 5 Transfer roll, 6 Cleaner, 7 Fixing device, 10 Image forming device, 40 Release member, 41 Release baffle, 42 Holder, 44 Conveyance for fixing device , 50 fixing device, 51 fixing belt, 52 pressure roll, 53 pressing portion, 54 belt guide member, 55 sliding member, 56 fixing device conveying portion, 57 holder, 60 fixing device, 61 fixing roll, 62 pressure Belt, 63 Belt running guide, 64 pressing member, 64a first pressing portion, 64b second pressing portion, 65 holder, 66 heater lamp, 67 lubricant application member, 68 sliding member, 69 temperature sensor, 71 fixing belt, 72 Pressing part, 73 Pressure roll, 74 Halogen lamp, 75 long hole, 76 Lubricant, 77 Sliding member, 78 Covering part, 79 Anchor part, 80 magnetic field generation unit, 81 excitation coil, 82 coil support member, 83 excitation circuit, 521 cored bar, 522 elastic body layer, 523 release layer, 611 core, 612 elastic body layer, 613 release layer.

Claims (7)

A nip portion that is arranged inside a rotating tubular body while contacting a rotatable rotating member is pressed against the rotating member to form a nip portion through which a recording medium passes between the rotating member and the tubular body. Having a pressing part to
The pressing member has a plurality of long holes whose longitudinal direction is a direction substantially parallel to the rotation axis direction of the tubular body.   The pressing member according to claim 1, wherein the pressing portion is made of metal. The pressing portion includes a first pressing portion disposed on the recording medium inlet side of the nip portion, and a second pressing portion disposed on the recording medium outlet side of the nip portion,
The at least second pressing portion of the first and second pressing portions has a plurality of long holes whose longitudinal direction is a direction substantially parallel to the rotation axis direction of the tubular body. Or the pressing member of 2.   The pressing according to any one of claims 1 to 3, wherein a lubricant or a sliding material is held in the long hole formed in the surface of the pressing portion facing the tubular body. Element. A sliding member disposed between the tubular body and the pressing portion;
The sliding member includes a covering portion that covers a surface of the pressing portion that contacts the sliding member, and an anchor portion that enters at least a part of the long hole formed on the surface of the pressing portion. And the said covering part and the said anchor part are united, The press member of any one of Claims 1-3 characterized by the above-mentioned.   A rotatable rotating member, a tubular body that rotates while contacting the rotating member, and disposed inside the tubular body, pressing the tubular body from the inner peripheral surface of the tubular body to the rotating member, A pressing unit having a pressing unit that forms a nip through which a recording medium passes between the rotating member and the tubular body, wherein the pressing unit is a pressing unit according to any one of claims 1 to 5. A fixing device which is a member. An image carrier, a latent image forming unit for forming a latent image on the surface of the image carrier, a developing unit for developing the latent image using a developer for developing an electrostatic image to form a toner image, and the toner Transfer means for transferring an image to a recording medium, and fixing means for fixing the toner image to the recording medium,
The image forming apparatus according to claim 6, wherein the fixing unit is the fixing device according to claim 6.