JP5287388B2 - Heat roller manufacturing method and fixing device including heat roller manufactured by the manufacturing method - Google Patents

Description

  The present invention relates to a fixing device installed in an image forming apparatus such as a copying apparatus, a facsimile apparatus or a printer apparatus, or a multifunction machine having these functions, and a method of manufacturing a heat roller used in the fixing apparatus.

As an image forming apparatus as described above, a recording medium such as a sheet is fed from a sheet storage unit such as a sheet cassette one by one, passed through a pair of conveyance (registration) rollers installed in the middle of a sheet conveyance path, and electrophotographic. An image recording unit that performs image recording may be used.
The toner image formed on the surface of the photosensitive drum is transferred to the sheet conveyed and supplied to the nip portion between the photosensitive drum and the transfer roller constituting the image recording unit. The sheet on which the toner image is transferred is fixed to the toner image by the fixing device, and is discharged to the discharge unit.

An example of the fixing device installed in the image forming apparatus includes a heat roller and a press roller that elastically contacts the heat roller. Such a fixing device fixes a toner image transferred onto a sheet as a permanent image by heating and pressing at a nip portion between a heat roller and a press roller.
As the heat roller, there is known a heat roller made of a hollow cylinder such as aluminum, in which a heating element such as a halogen lamp is accommodated, and the hollow cylinder is heated by the halogen lamp.
A heat roller containing such a halogen lamp has a problem that power consumption is relatively large, and a warm-up time until the outer surface (outer peripheral surface) of the heat roller reaches a predetermined temperature (fixing temperature) after the power is turned on. There was a problem of becoming longer.

Therefore, recently, a heat roller has been proposed in which a planar (sheet-like) heating element (or a layer including a heating element) is arranged on the inner peripheral surface of a hollow cylindrical base material.
For example, in Patent Document 1 below, heat fixing includes a metal pipe, a heat-resistant insulating layer including a heating element disposed on the inner peripheral surface of the metal pipe, and a pressure contact body attached to the inner surface of the heat-resistant insulating layer. Laura has been proposed.
The pressure contact member is formed of a rubber elastic pipe having an outer diameter that is 0 to 30% larger than the inner diameter of the metal pipe. The heat fixing roller has a heat-resistant insulating layer provided with the heating element and the metal elastic pipe. It is configured to be pressed and fixed to the inner peripheral surface of the pipe.

Patent Document 2 below proposes a roll heater in which a heat generating sheet having a resistance heat generating member formed on one surface is fixed to an inner peripheral surface of a cylindrical roller member with a heat conductive viscosity agent. Yes.
The heat generating sheet has an insulating member formed on the outer peripheral surface side (the inner peripheral surface side of the roller member) of the resistance heat generating member, and a heat conductor made of elastic phosphor bronze is provided on the outer peripheral surface side of the insulating member. It has been configured. In this roll-shaped heater, silicone grease as a viscosity agent is applied to the surface of the heat conductor of the heat generating sheet or the inner peripheral surface of the roller member, and the viscosity of the viscosity agent and the elasticity of the heat conductor are utilized. The heat generating sheet is configured to be in close contact with the inner peripheral surface of the roller member.

Japanese Patent No. 3436625 JP 2001-28289 A

However, in the heat fixing roller described in Patent Document 1, the heat quantity of the heat generating member of the heat-resistant insulating layer is taken away by the rubber elastic pipe having a relatively large heat capacity attached to the inner surface of the heat-resistant insulating layer. . Therefore, there is a problem that the metal pipe cannot be efficiently heated and the warm-up time becomes relatively long.
In the roll heater described in Patent Document 2, the heat generating sheet is configured to be in close contact with the inner peripheral surface of the roller member by the viscosity of the viscosity agent and the elasticity of the heat conductor. ing. Accordingly, it is conceivable that a positional deviation or the like occurs between the roller member and the heat generating sheet depending on the usage mode (fixing temperature or rotational speed) of the device, and further improvement has been desired.

  The present invention has been made in view of the above situation, and can improve the adhesion between the inner peripheral surface of the hollow cylindrical base material and the heating element, and can also reduce the warm-up time, and a heat roller manufacturing method, and It is an object of the present invention to provide a fixing device including a heat roller manufactured by the manufacturing method.

In order to achieve the above object, a manufacturing method of a heat roller according to the present invention is a manufacturing method of a heat roller used in a fixing device for fixing a toner image formed on a recording medium, and has a hollow cylindrical shape. In the hollow portion of the base material, a mesh-like cylinder that can be enlarged and reduced in the radial direction is accommodated in a state in which the diameter is reduced, and then the diameter of the mesh-like cylinder is enlarged and the mesh- like cylinder is a heating element disposed on the outer peripheral side in close contact with the inner peripheral surface of the substrate, characterized that you fixed.

  In the heat roller manufacturing method according to the present invention, the mesh cylinder may be a mesh spring cylinder in which a spring material is formed in a mesh and a cylinder. In this case, in a state where the diameter reduction state of the mesh spring cylinder is restrained by the restraining member, it is accommodated in the hollow portion of the base material, and then the restraining state by the restraining member is released to restore the elasticity. It is preferable to enlarge the diameter of the mesh spring cylinder by force.

  Alternatively, in the method for manufacturing the heat roller according to the present invention, the mesh tube is formed as a mesh fiber tube in which heat-resistant fibers containing an uncured thermosetting heat-resistant resin are formed in a mesh shape and a tube shape. Also good. In this case, a heat-resistant tube that can be expanded by the introduction of the medium is inserted into the mesh fiber cylinder, and the diameter of the mesh fiber cylinder is reduced in the hollow portion of the base material. Preferably, the heat-resistant tube is expanded, the diameter of the mesh fiber cylinder is expanded, and the thermosetting heat-resistant resin is cured by heating while maintaining the expanded state.

In any one of the heat roller manufacturing methods according to the present invention, the heating element may be a planar heating element. In this case, the planar heating element is fixed to the inner peripheral surface of the base material by enlarging the diameter of the mesh cylinder.
In order to achieve the above object, a method for manufacturing a heat roller according to the present invention is a method for manufacturing a heat roller used in a fixing device for fixing a toner image formed on a recording medium. In a hollow portion of a base material having a shape, a mesh-like cylindrical body as a heating element that can be enlarged and reduced in the radial direction and made of an electrothermal resistance material is accommodated in a state in which the diameter is reduced, and then the mesh-like cylindrical body The mesh-shaped cylindrical body is fixed in close contact with the inner peripheral surface of the substrate by enlarging the diameter.

  In order to achieve the above object, a fixing device according to the present invention includes a heat roller manufactured by any one of the heat roller manufacturing methods, and a press roller that elastically contacts the heat roller. It is characterized by that.

According to the method for manufacturing a heat roller according to the present invention, a mesh-like cylinder that can be enlarged and reduced in the radial direction is accommodated in a hollow portion of the base material in a state where the diameter is reduced, and then the mesh-like cylinder is stored. The diameter of the body is enlarged to fix the heating element to the inner peripheral surface of the base material. Therefore, the heating element can be fixed to the inner peripheral surface of the base material by a simple method, and the heating element is fixed by utilizing the expansion in the radial direction of the mesh-shaped cylindrical body. It is possible to improve the adhesion between the inner peripheral surface and the heating element by a simple method.
In addition, since the member that fixes the heating element to the inner peripheral surface of the base material is a mesh-like cylindrical body, the heat capacity is relatively small, and heat from the heating element is efficiently transferred to the base material, The substrate can be heated. Therefore, the warm-up time of the heat roller can be shortened.
Alternatively, it is also possible to grasp the mesh-like cylinder as a heating element by using the mesh-like cylinder made of an electrothermal resistance material. According to this, the heat capacity of the heating element itself can be reduced, and the warm-up time of the heat roller can be shortened.

In the heat roller manufacturing method according to the present invention, the mesh-shaped cylinder is a mesh-like spring cylinder formed of a spring material in a mesh-like and cylindrical shape, and the diameter of the mesh-like spring cylinder is reduced by a restraining member. In a state where the state is constrained, it is accommodated in the hollow portion of the base material, and then the state of restraint by the constraining member is released, and the diameter of the mesh spring cylinder is enlarged by an elastic restoring force. The following effects are achieved.
That is, since the heating element is fixed to the inner peripheral surface of the base material using the elastic restoring force of the mesh spring cylinder, the adhesion between the inner peripheral surface of the base material and the heating element is further improved. While being able to improve effectively, this heat generating body can be more firmly fixed to the internal peripheral surface of a base material.

Alternatively, in the method for producing the heat roller according to the present invention, the mesh tube is a mesh fiber tube formed of a heat-resistant fiber containing an uncured thermosetting heat-resistant resin in a mesh shape and a tube shape, A heat-resistant tube that can be expanded by introduction of a medium is inserted into the mesh fiber cylinder, and is contained in the hollow portion of the base material in a state where the diameter of the mesh fiber cylinder is reduced, and then If the heat-resistant tube is expanded to expand the diameter of the mesh fiber cylinder and heated while maintaining the expanded state, the following effects can be obtained.
That is, the heat-resistant tube is expanded to expand the diameter of the mesh fiber cylinder, and the thermosetting heat-resistant resin of the mesh fiber cylinder is cured by heating while maintaining the expanded state. Therefore, the adhesiveness between the inner peripheral surface of the substrate and the heating element can be improved more effectively.
In addition, for example, when the substrate is made of a metal aluminum pipe or the like in order to increase thermal conductivity and rigidity, the degree of thermal expansion is larger than that of the substrate, and the heat generation is performed. By energizing the body, the mesh fiber cylinder is thermally expanded and its diameter is expanded. Thereby, this heat generating body can be firmly fixed to the inner peripheral surface of a base material.

In any one of the heat roller manufacturing methods according to the present invention, the heating element is a planar heating element, and the planar heating element is expanded by increasing the diameter of the mesh-shaped cylindrical body. If fixed to the peripheral surface, the following effects can be obtained.
That is, since the planar heating element is fixed to the inner peripheral surface of the base material by the mesh-like cylindrical body, the heat capacity is relatively small, and the heat from the planar heating element is efficiently transferred to the base material. The substrate can be heated. Therefore, the warm-up time of the heat roller can be shortened.

Alternatively, in the configuration in which the mesh-like cylinder is a mesh-like spring cylinder in which a spring material is formed in a mesh-like and cylinder shape, the mesh-like spring cylinder is made of an electrothermal resistance material, and the mesh-like spring cylinder If the body is configured to be fixed to the inner peripheral surface of the base member with an enlarged diameter, the following effects can be obtained if the heating element is configured.
That is, since the heating element itself is formed of a mesh-like cylinder, the heat capacity can be reduced, and the warm-up time of the heat roller can be shortened.

The fixing device according to the present invention includes a heat roller manufactured by any one of the heat roller manufacturing methods, and a press roller that elastically contacts the heat roller. Therefore, since the heating element and the inner peripheral surface of the base material are in close contact as described above, uneven fixing or poor fixing can be prevented.
Further, as described above, the heat roller efficiently conducts heat from the heating element to the base material and can shorten the warm-up time, so that energy saving (power saving) can be achieved.

1 is a schematic longitudinal sectional view illustrating an example of an image forming apparatus to which an embodiment of a fixing device according to the present invention is applied. FIG. 2 is a schematic longitudinal sectional view schematically showing an example of the fixing device and a partially enlarged schematic longitudinal sectional view. FIG. 2 is a schematic longitudinal sectional view schematically showing an example of a mesh-like cylindrical body of a heat roller provided in the fixing device and showing a state in which the diameter is expanded. It is a schematic longitudinal cross-sectional view which shows the state which contracted the diameter of the same mesh-shaped cylinder. It is explanatory drawing for demonstrating one Embodiment of the manufacturing method of the heat roller which concerns on this invention, and is a schematic longitudinal cross-sectional view of the base material of the heat roller. It is explanatory drawing of the manufacturing method. It is explanatory drawing of the manufacturing method. It is a schematic longitudinal cross-sectional view which shows typically an example of the heat roller manufactured by the manufacturing method. It is explanatory drawing for demonstrating other embodiment of the manufacturing method of the heat roller which concerns on this invention, and is a schematic longitudinal cross-sectional view which shows the state which shrunk | reduced the diameter of the mesh-shaped cylinder. It is a partially expanded schematic longitudinal cross-sectional view which shows typically an example of the heat roller manufactured by the manufacturing method. It is explanatory drawing for demonstrating other embodiment of the manufacturing method of the heat roller which concerns on this invention, and is a schematic longitudinal cross-sectional view which shows the state which inserted the heat resistant tube in the mesh shaped cylinder. It is explanatory drawing of the manufacturing method. It is explanatory drawing of the manufacturing method. It is a schematic longitudinal cross-sectional view which shows typically an example of the heat roller manufactured by the manufacturing method.

Embodiments of the present invention will be described below with reference to the drawings.
FIGS. 1-8 is explanatory drawing for demonstrating an example of the manufacturing method of the fixing device which concerns on 1st Embodiment, and the heat roller with which this fixing device is provided.
In the following description of each embodiment, the upstream side and the downstream side will be described with reference to the conveyance direction of a sheet conveyed through a sheet conveyance path described later.
Further, in each drawing showing the mesh-like cylinder, the mesh-like cylinder is schematically shown, and as will be described later, about the expansion and contraction of the length along the roller axis direction when the diameter is enlarged or reduced. The illustration is omitted.

The image forming apparatus 1 illustrated in FIG. 1 is illustrated by taking a printer including an electrophotographic recording unit as an example, but is not limited thereto, and is not limited thereto, a copying machine including an image reading apparatus, a facsimile apparatus, or functions thereof. It may be a so-called multi-function machine or the like having both of the above. In addition, the fixing device according to the present embodiment can be applied to various apparatuses including a recording unit of various color recording methods and the like without being limited to a monochrome electrophotographic recording unit.
The apparatus main body 10 of the image forming apparatus 1 accommodates and supplies paper (recording medium), a paper supply unit 2, an image recording unit composed of an electrophotographic process unit 3 and a fixing device 4, and a post-recording unit The recording paper discharge unit 5 is configured to be stacked in the height direction in this order.
An image reading apparatus including an ADF (auto document feeder) reading unit and an FBS unit (flat bed scanner unit) for realizing an image reading function and a copying function can be installed on the upper part of the apparatus body 10. Has been.

The paper supply unit 2 includes a paper cassette 20 that constitutes a paper storage unit that can store a large number of sheets in a stacked state, a separation roller 22 installed at a front end portion of the paper cassette 20 in the paper conveyance direction, and the separation roller 22 and a separation pad 21 that elastically contacts the peripheral surface of 22.
The paper cassette 20 can be inserted into and removed from the apparatus main body 10. Further, the paper cassette 20 includes a push-up plate 23 to which elasticity is always applied upward by a compression coil spring or the like. Further, the paper cassette 20 regulates the rear end of the paper, is given elasticity in the transport direction, and matches the paper size. It is equipped with an end guide that can be adjusted in position.
In the paper supply unit 2, the front end of the paper stored and accumulated in the paper cassette 20 is pressed against the circumferential surface of the separation roller 22. When the separation roller 22 rotates, the stacked sheets are separated one by one from the uppermost layer portion by the cooperative action of the separation roller 22 and the separation pad 21, and are fed out toward the sheet conveyance path 6 described later. The

The process unit 3 includes a plus (or minus) charger 31, an exposure device 32 including an LED, a developing device 33, a transfer roller (transfer device) 34, and a cleaning device 35 around the photosensitive drum 30. Arranged in this order.
The photosensitive drum 30, the charger 31 and the cleaning device 35 are unitized as a drum unit, and the developing device 33 is unitized as a developing unit, and both units are individually or relative to the apparatus body 10. It is detachably mounted in a combined state.
A registration roller pair 61 is installed in the vicinity of the upstream side of the process unit 3. The paper fed from the paper cassette 20 is registered by the registration roller pair 61 and introduced into the nip portion between the photosensitive drum 30 and the transfer roller 34.
The surface of the photosensitive drum 30 is rotated positively (or minus) by the charger 31 while rotating in the direction of the arrow in FIG. 1, and an optical image based on the image information is transferred to the photosensitive drum 30 by the exposure device 32. The surface is irradiated and an electrostatic latent image is formed on the surface of the photosensitive drum 30.

The electrostatic latent image is successively developed by the developing unit 33 to be a toner image. This toner image reaches the nip portion with the transfer roller 34 as the photosensitive drum 30 rotates. The registration roller pair 61 is rotationally driven under registration control so that the paper is introduced into the nip portion in synchronization with the movement of the toner image on the surface of the photosensitive drum 30.
The transfer roller 34 nips and conveys the sheet while being rotationally driven as described above, and the toner image on the surface of the photosensitive drum 30 is transferred to the sheet by passing through the nip portion. The recorded paper on which the toner image has been transferred is introduced into a fixing device 4 to be described later, heated and pressurized to be fixed as a permanent image, and then reaches the discharge unit 5.
The residual toner remaining on the surface of the photosensitive drum 30 that has passed through the nip portion with the transfer roller 34 is collected by the cleaning device 35 and returned to the developing unit 33 as recycled toner.
The series of paper transports rises substantially vertically (vertically) immediately after feeding out from the paper cassette 20, and makes a U-turn on the downstream side of the fixing device 4 in a direction of about 180 degrees from the feeding direction from the paper cassette 20. It is made along the paper conveyance path 6 formed as described above.

In the present embodiment, the developing device 33 exemplifies a developing device using a two-component developer. The developing device 33 stores a developer composed of toner and carrier in a resin-molded casing, and in the casing, there is a stirring member for stirring the developer and a photosensitive drum. A developing roller for supplying toner is provided.
In addition, a toner bottle 36 for storing toner and a toner hopper 37 for temporarily storing toner from the toner bottle 36 are installed at positions separated from the developing device 33. The toner accommodated in the toner bottle 36 is supplied to the developing device 33 by a screw conveyor (pipe screw) 38 through a toner hopper 37.
The developing device 33 is not limited to a method using a two-component developer, and a one-component method and other methods can also be adopted.

The discharge unit 5 includes a discharge roller pair 50 installed on the downstream side of the fixing device 4 to be described later, and a discharge tray 51 for stacking discharged recorded sheets.
By rotating the discharge roller pair 50, a recorded sheet on which a toner image is fixed by the fixing device 4 described later is discharged toward the discharge tray 51.

The paper supply unit 2 is not limited to the illustrated separation pad type, and may be a separation claw type or retard roller type supply unit including a half-moon roller and a separation claw.
In FIG. 1, reference numeral 24 denotes a manual feed supply unit that constitutes a part of the paper supply unit 2. The manual feed tray provided on the side of the apparatus body 10 so as to be openable and closable, Separating and feeding means and the like are provided. The paper supplied from the manual feed supply unit is joined to the paper transport path 6 through the manual transport path.
In FIG. 1, reference numeral 60 denotes a transport path for transporting paper from the optional cassette when an optional cassette (not shown) as a multi-stage cassette system is installed under the paper cassette 20. The conveyance path 60 constitutes a part of the sheet conveyance path 6.
In FIG. 1, reference numeral 62 denotes a switching gate provided on the downstream side of the fixing device 4, and the recorded paper recorded on one side as described above through the paper transport path 6 is transferred to the discharge roller pair 50. Is reversely rotated and guided to the reverse conveyance path 7 for double-sided recording.

Next, an example of a fixing device according to the present embodiment and a method for manufacturing a heat roller included in the fixing device will be described with reference to FIGS.
As shown in FIG. 2, the fixing device 4 is disposed on the downstream side of the process unit 3 (see FIG. 1), and the heat roller 40 pressed against each other in a resin-molded fixing device housing 42. And a press roller 41.
An upstream opening 421 for receiving a sheet onto which a toner image conveyed along the sheet conveyance path 6 is transferred is provided on the upstream side wall (lower side of the sheet in FIG. 2) of the fixing device housing 42. In addition, a downstream opening 422 for discharging the recorded sheet on which the toner image is fixed toward the discharge unit 5 is provided on the downstream side wall of the fixing device housing 42 (above the paper surface in FIG. 2).
When the fixing device 4 is mounted on the apparatus main body 10, the nip portion between the heat roller 40 and the press roller 41 is arranged along the sheet conveyance path 6 as shown in FIG. 1.

Further, the fixing device housing 42 is provided with peeling claws 43 for peeling the conveyed paper from the heat roller 40 and guide ribs 420 for guiding the conveyance of the paper at a plurality of locations along the roller axial direction.
The base end portion of the peeling claw 43 is swingably supported, and elasticity is always applied by a torsion spring or the like so that the distal end contacts the outer peripheral surface of the heat roller 40.
The fixing device housing 42 is provided with a temperature sensor 44 such as a thermistor for measuring the surface temperature of the heat roller 40. Based on the measured temperature output from the temperature sensor 44, energization (ON) is applied to the planar heating element 402 (resistance heating element 142) described later so that the outer peripheral surface of the heat roller 40 is maintained at a predetermined fixing temperature. / OFF) is controlled.
Although not shown, the fixing device housing 42 is provided with a power supply unit for supplying power to the resistance heating element 142 of the heat roller 40 described later.

As shown in FIGS. 2 and 8, the heat roller 40 generally follows the base material 400, the release layer 401 formed on the outer peripheral surface of the base material 400, and the inner peripheral surface of the base material 400. A fixed sheet heating element 402 and a mesh spring cylinder 403 disposed inside the sheet heating element 402 are provided.
As shown in FIG. 5, the base material 400 is made of an aluminum pipe having a hollow cylindrical shape.
The release layer 401 is for reducing adhesion of toner or paper powder, and is made of, for example, a fluorine-based resin such as tetrafluoroethylene / perfluoroalkylvinyl copolymer, and is formed on the outer peripheral surface of the substrate 400. It is fixed or coated with an adhesive or the like. The thickness of the release layer 401 may be about 30 μm to 50 μm.
The base material 400 is not limited to the aluminum pipe, and may be made of other metal materials. Alternatively, the substrate 400 may be formed of a synthetic resin having electrical insulating properties and heat resistance, for example, a synthetic resin such as polyphenylene sulfide (PPS), or ceramics in a hollow cylindrical shape.

The planar heating element 402 has a generally three-layer structure in which a resistance heating element 142, a heat-resistant insulating layer 242 and a heat transfer layer 342 are stacked in this order outward in the radial direction. It is arrange | positioned toward the inner peripheral surface side. Further, on the opposite side, a heat-resistant insulating coating layer 442 is provided to cover the resistance heating element 142 so as to leave both ends in the roller axial direction. In this embodiment, the heat-resistant insulating coating layer 442 is also provided. The four layers included are grasped as the planar heating element 402.
In addition, electrode portions are provided at both ends of the resistance heating element 142 that is not covered with the heat-resistant insulating layer 442, and is electrically connected to the power feeding portion to supply power.
Examples of the heat transfer layer 342 include a copper foil having high thermal conductivity, and a thickness of about 10 μm to 30 μm. The heat transfer layer 342 may be other metal material such as aluminum, or may be ceramic such as aluminum nitride or silicon carbide.
Examples of the heat-resistant insulating layer 242 and the heat-resistant insulating coating layer 442 include those made of a heat-resistant adhesive having electrical insulation and heat resistance. For example, the heat-resistant insulating layer 242 and the heat-resistant insulating coating layer 442 may be formed of a polyimide-based, phenol-based, or silicone-based adhesive. May be. The heat-resistant insulating layer 242 may be thick enough to electrically insulate the heat transfer layer 342 and the resistance heating element 142, and has a thickness of about 10 μm to 70 μm, for example. Similarly, the heat-resistant insulating coating layer 442 may have a thickness that can electrically insulate the resistance heating element 142 and the mesh spring cylinder 403 described later.
The resistance heating element 142 is made of stainless steel, nickel chrome, or the like, and the resistance heating element 142 has a heater pattern formed in a plurality of lines. The resistance heating element 142 has a thickness of about 10 μm to 70 μm.

The planar heating element 402 forms the heat-resistant insulating layer 242 with a predetermined thickness on one surface of the copper foil that becomes the heat transfer layer 342, for example. Next, a foil-like material made of stainless steel or nickel chrome is fixed to the heat-resistant insulating layer 242 by heating and pressing. Next, the heat-resistant insulating coating for forming the resistance heating element 142 by forming a heater pattern by processing into a pattern shape having a plurality of lines by a known method such as wet etching, and further covering the resistance heating element 142 The layer 442 may be formed.
With such a configuration, the planar heating element 402 becomes a flexible sheet-like heater. The sheet heating element 402 is rounded into a cylindrical shape so that the heat-resistant insulating coating layer 442 faces the axial center side, and is arranged so as to follow the inner peripheral surface of the base material 400. The spring cylinder 403 is fixed to the inner peripheral surface of the substrate 400.
The heater pattern forming the resistance heating element 142 is not limited to the above example, and may be formed by sputtering, vapor deposition, pattern printing, blasting, or the like.
The heat-resistant insulating layer 242 and the heat-resistant insulating coating layer 442 may be made of another adhesive having heat resistance that can withstand a predetermined fixing temperature. For example, a thermosetting epoxy type, acrylic type, or the like You may make it form with this adhesive agent.

The mesh spring cylinder 403 functions as a fixing member for fixing the planar heating element 402 to the inner peripheral surface of the base material 400. In this embodiment, stainless steel, stainless steel, nickel chromium alloy, tungsten, It is made of a metal spring material such as hard steel wire or copper nickel alloy.
The mesh spring cylinder 403 is formed, for example, by forming a metal spring material in a thin plate shape into a mesh shape (mesh shape) by punching, etching, laser processing, or the like, and rounding and welding the mesh thin plate. Or it joins and is formed in the cylinder shape. Alternatively, a metal pipe made of a metal spring material having a cylindrical shape may be formed in a mesh shape by the same processing method as described above.
The mesh-like spring cylinder 403 formed in a mesh-like and cylindrical shape with such a metal spring material is in a state where the diameter is expanded (expanded) in an unloaded state (a state where no external force is acting, a natural state). (Expanded state) (see FIG. 3). On the other hand, when an external force is applied from the outside in the radial direction to the inside, the diameter is contracted (reduced) (see FIG. 4). If the external force applied to the mesh spring cylinder 403 in the contracted state is unloaded, the mesh spring cylinder 403 returns to the expanded state by the elastic restoring force. That is, the mesh spring cylinder 403 has a self-expanding function (self-expandable function).

In the expanded state shown in FIG. 3, the mesh spring cylinder 403 has an outer diameter of the mesh spring cylinder 403 of the base material 400 in a state where the planar heating element 402 is fixed to the inner peripheral surface. It is formed to be larger than the inner diameter. Further, in the contracted state shown in FIG. 4, the outer diameter of the mesh-like spring cylinder 403 is formed to be smaller than the inner diameter of the substrate 400 in a state where the planar heating element 402 is fixed to the inner peripheral surface. Has been.
As shown in FIGS. 2 and 8, the mesh-like spring cylinder 403 is expanded in diameter in the hollow portion of the base material 400 in a state where the planar heating element 402 is arranged on the inner peripheral surface. It arrange | positions so that the inner side surface (surface of the axial center side) of the heating element 402 may be followed. The mesh-like spring cylinder 403 is configured to press the planar heating element 402 against the inner peripheral surface of the substrate 400 by the elastic restoring force of the mesh-like spring cylinder 403 so that the planar heating element 402 is pressed. Is fixed to the inner peripheral surface of the substrate 400.

By using the mesh-like spring cylinder 403 as a fixing member for fixing the planar heating element 402 to the inner peripheral surface of the base member 400 as described above, for example, fixing with a rubber elastic pipe or the like In comparison, the heat capacity of the fixing member itself is reduced. Therefore, the heat from the planar heating element 402 is efficiently transferred to the base material 400, the base material 400 can be heated, and the warm-up time of the heat roller 40 can be shortened.
In addition, since the planar heating element 402 is fixed to the inner peripheral surface of the base material 400 using the elastic restoring force of the mesh-like spring cylinder 403, for example, an adhesive or the like is a simple method. There is no risk of peeling due to the difference in linear expansion coefficient as compared with the case fixed with. Therefore, the adhesion between the planar heating element 402 and the base material 400 can be improved.

The mesh spring cylinder 403 is not limited to one made of a metal spring material, and may be made of another spring material such as a synthetic resin material having heat resistance and elasticity. . In this case, the heat-resistant insulating coating layer 442 may not be provided. Alternatively, the mesh spring cylinder 403 may be formed of a metal spring material having shape memory characteristics.
The mesh shape of the mesh-like spring cylinder 403 is not limited to the shape in which the individual openings are in the shape of rhombus as shown in the figure, and the shape in which the openings are in the shape of a honeycomb hexagon. Other various geometric shapes may be used.

Further, the mesh-like spring cylinder 403 formed as described above may be chamfered, or the surface may be coated with metal plating or synthetic resin.
Furthermore, although the mesh-like spring cylinder 403 is arranged over the entire length of the base member 400 in the roller axial direction as shown in FIG. 8, the following embodiment may be adopted. For example, when a roller shaft member, which will be described later, is fitted to both ends of the base material 400 in the roller axis direction, the mesh spring cylinder 403 is a roller so as to leave an allowance for the roller shaft member. It is good also as an aspect arrange | positioned only to the center side site | part of an axial direction. Further, the mesh-like spring cylinder 403 is disposed only at the central portion in the roller axial direction so as not to contact the resistance heating element 142 and the electrode portion thereof where the heat-resistant insulating coating layer 442 is not formed as described above. It is good also as an aspect which does.

Roller shaft members (not shown) are provided at both ends of the heat roller 40 configured as described above, and are rotatably supported by bearings (not shown) or the like provided in the fixing device housing 42. . In addition, a gear or the like is fixed to one end of the roller shaft member, and driving by a driving unit (not shown) such as a motor provided in the apparatus main body 10 is transmitted to the gear or the like, so that heat is generated. The roller 40 is rotationally driven.
As the heat roller 40 is driven to rotate, a press roller 41, which will be described later, is driven to rotate, and the paper introduced into the nip portion is conveyed in the nip. While the sheet passes through the nip portion, the transferred toner image is fixed on the sheet by heating and pressurization, and is conveyed toward the discharge unit 5 (see FIG. 1) as a recorded sheet.

As shown in FIG. 2, the press roller 41 includes a press roller shaft 410 formed of a metal material such as a steel material, a cylindrical elastic member 411 sheathed on the press roller shaft 410, a release layer 412, Consists of.
The cylindrical elastic member 411 is made of a rubber body such as silicone or urethane or a sponge body, and is fixed to the press roller shaft 410 with an adhesive or the like.
The release layer 412 is formed on the outer peripheral surface of the cylindrical elastic member 411. For example, a fluorine such as a tetrafluoroethylene / perfluoroalkylvinyl copolymer is used to improve the peelability of paper, toner or paper powder. It consists of a resin tube.
In addition, as a metal material applied to a press roller axis | shaft, it is good also as what gave nickel plating to steel materials, such as SUM24L and S20C. Further, the thickness of the release layer 412 may be about 30 μm to 50 μm.

Both ends of the press roller shaft 410 are rotatably supported by the bearing body 423. The bearing body 423 is slidably provided with respect to the fixing device housing 42 and is pressed toward the heat roller 40 by the elastic force of an elastic member 424 made of a coil spring or the like fixed to the fixing device housing 42. .
By this elastic member 424, the press roller 41 is pressed against the heat roller 40, and the press roller 41 elastically contacts the heat roller 40, thereby forming a nip portion.
As described above, since the fixing device 4 according to the present embodiment includes the heat roller 40, the adhesion between the planar heating element 402 and the inner peripheral surface of the substrate 400 is improved as described above. As a result, uneven fixing or defective fixing can be prevented. Further, the heat roller 40 efficiently transfers heat from the planar heating element 402 to the base material 400 as described above, and can reduce the warm-up time. Power).

The elastic member 424 has a base end portion fixedly supported by a metal chassis (not shown) fixed in the fixing device housing 42.
Further, the elastic member 424 is not limited to a coil spring, and may be any pressing member that can press the press roller 41 against the heat roller 40.
Further, although not shown, the fixing device 4 includes a nip releasing mechanism that releases the nip state (contact state) between the heat roller 40 and the press roller 41. Further, a cleaning roller or a cleaning blade for removing paper dust and toner adhering to the surface of the heat roller 40 is provided.

Next, an example of a method for manufacturing the heat roller 40 having the above configuration will be described.
5 to 8, the illustration of the release layer 401 is omitted.
First, as shown in FIG. 6, the heat transfer layer 342 (see FIG. 2) of the planar heating element 402 is on the outer peripheral side so as to follow the inner peripheral surface of the base material 400 shown in FIG. 5. The planar heating element 402 is rolled into a cylindrical shape and disposed in the hollow portion of the base material 400.
Next, as shown in FIG. 7, the solidified mesh spring cylinder 433 in a contracted state by the restraining member is accommodated in the hollow portion of the base material 400 on which the planar heating element 402 is disposed.
Examples of the restraining member include wax that melts, sublimes, or melts at a relatively low temperature. By the wax, the mesh-like spring cylinder 403 (see FIG. 4) that is in a contracted state is solidified. The solidified mesh spring cylinder 433 is formed.

  The solidified net-like spring cylinder 433 solidified by the wax as described above is accommodated, and the base material 400 on which the planar heating element 402 is disposed is heated by a heater such as a heat gun to melt the wax. Let Thereby, the restriction by the wax is released, and the mesh spring cylinder 403 is expanded in diameter by an elastic restoring force as shown in FIG. 8, and the base material 400 on which the planar heating element 402 is arranged. It expands in the hollow part. By the expansion of the mesh spring cylinder 403, the planar heating element 402 is pressed against the inner peripheral surface of the base member 400 and fixed so as to follow the inner peripheral surface of the base member 400.

As described above, according to the method for manufacturing a heat roller according to the present embodiment, the planar heating element 402 can be fixed to the inner peripheral surface of the substrate 400 by a simple method.
Further, in the present embodiment, the planar heating element 402 is fixed to the inner peripheral surface of the substrate 400 by utilizing the elastic restoring force of the mesh spring cylinder 403. The body 402 can be firmly fixed to the inner peripheral surface of the substrate 400.

Next, another embodiment according to the present invention will be described with reference to the drawings.
FIG. 9 is an explanatory view for explaining a manufacturing method of the heat roller according to the second embodiment, and is a schematic longitudinal sectional view showing a state in which the diameter of the mesh-like cylindrical body is contracted. FIG. It is a partially expanded schematic longitudinal cross-sectional view which shows typically an example of the heat roller manufactured by this.
Note that differences from the first embodiment will be mainly described, and the same components are denoted by the same reference numerals, and description thereof will be omitted or simplified. Also, the description of the same steps will be omitted or briefly described.

The heat roller 140 (see FIG. 10) manufactured by the heat roller manufacturing method according to the present embodiment is greatly different from the first embodiment in the configuration of the heating element fixed to the inner peripheral surface of the base material.
That is, in the heat roller 140, the mesh spring cylinder 404 itself constitutes a heat generating body of the heat roller 40.
The mesh-like spring cylinder 404 is made of an electrothermal resistance material among the spring materials, and is formed in a mesh-like and cylinder-like shape as described above.
Moreover, in this embodiment, the base material is comprised from the aluminum pipe 400 similar to the above, and the heat-resistant insulating layer 141 formed on the inner peripheral surface of the aluminum pipe 400. The heat-resistant insulating layer 141 is made of a heat-resistant adhesive having electrical insulation and heat resistance, similar to the heat-resistant insulating layer 242 (see FIG. 2) of the first embodiment. For example, polyimide-based, phenol-based Alternatively, it is formed into a thin film with a silicone-based adhesive as described above.

In the heat roller manufacturing method according to the present embodiment, the configuration of the restraining member for restraining the contracted state of the mesh-like spring cylinder 404 is different from that of the first embodiment.
That is, in this embodiment, as shown in FIG. 9, the restraining yarn 8 is used as a restraining member for restraining the contracted state of the mesh spring cylinder 404.
After the mesh-like cylindrical body 404 whose contracted state is constrained by the constraining yarn 8 in this manner is accommodated in the hollow portion of the base material, as in the first embodiment, the constraining yarn 8 is unwound and removed. By cutting or cutting, the restrained state is released as in the first embodiment. By releasing the restraint state, the mesh spring cylinder 404 is expanded in diameter by the elastic restoring force, expands in the hollow portion of the base material, and is fixed to the inner peripheral surface, as in the first embodiment. And constitutes a heating element.

As described above, according to the manufacturing method of the heat roller according to the present embodiment, a mesh spring cylinder as a heating element is formed on the inner peripheral surface of the base material of the heat roller 140 by a simple method as in the first embodiment. 404 can be fixed.
In addition, since the heating element itself is a net-like cylinder, the heat capacity can be reduced, and the warm-up time of the heat roller 140 can be shortened.

In addition, an aspect in which the electrode portion is configured by providing an electrode member by welding or the like at both ends in the roller axial direction of the mesh-like spring cylinder 404, or by making the both ends denser than the center side. It is good.
Further, in place of the thin-film heat-resistant insulating layer 141 formed on the inner peripheral surface of the aluminum pipe 400 as described above, a thin heat-resistant insulating sheet formed on the inner peripheral surface of the aluminum pipe 400 is disposed. It is good also as such an aspect.
Alternatively, instead of providing the heat-resistant insulating portion on the inner peripheral surface of the aluminum pipe 400, the mesh-like spring cylinder 404 is coated with the same heat-resistant insulating resin as described above, so that the mesh-like spring cylinder 404 and the aluminum are coated. The pipe 400 may be electrically insulated.
Furthermore, the heat roller 140 manufactured by the manufacturing method according to the present embodiment may be provided in the fixing device 4 instead of the heat roller 40 described in the first embodiment.

In addition, the restraining member (wax) described in the first embodiment may be used in place of the restraining yarn 8 according to the present embodiment. Further, the binding yarn 8 according to the present embodiment may be used in the first embodiment instead of the wax according to the first embodiment.
Furthermore, in the first embodiment and the second embodiment, as a restraining member for restraining the contracted state of the mesh-like spring cylinder, wax and restraint yarn are exemplified, but not limited thereto, for example, It is good also as a tube member which accommodates the mesh-like spring cylinder in a contracted state. Or it is good also as an aspect which restrains the contraction state of a mesh shaped spring cylinder by a some ring-shaped member or a clip-shaped member.

Next, still another embodiment according to the present invention will be described with reference to the drawings.
FIGS. 11-14 is explanatory drawing for demonstrating the manufacturing method of the heat roller which concerns on 3rd Embodiment, and the heat roller manufactured by this manufacturing method.
Note that differences from the first embodiment will be mainly described, and the same components are denoted by the same reference numerals, and description thereof will be omitted or simplified. Also, the description of the same steps will be omitted or briefly described.
In addition, in FIGS. 12 to 14, the release layer 401 is not shown.

In the present embodiment, the configuration of the mesh cylinder as a fixing member for fixing the planar heating element 402 to the inner peripheral surface of the base material 400 is the same as that of the mesh spring cylinder 403 described in the first embodiment. Is different.
That is, as shown in FIG. 14, the heat roller 240 manufactured by the manufacturing method according to the present embodiment has a mesh fiber as a fixing member for fixing the planar heating element 402 to the inner peripheral surface of the base material 400. A cylindrical body 405 is used.
The mesh-like fiber cylinder 405 is formed by forming a heat-resistant fiber containing an uncured (semi-cured, prepreg) thermosetting heat-resistant resin into a mesh-like and tubular shape.

Examples of the heat resistant fiber include carbon fiber, glass fiber, aramid fiber, texalium fiber, ceramic fiber, silica fiber, and alumina fiber. The heat-resistant fibers are coated or impregnated with, for example, a phenol-based or silicone-based thermosetting heat-resistant resin, and the fibers are knitted into a mesh shape and a tubular shape to form the mesh-like fiber cylinder 405. May be. Alternatively, the mesh-like fiber cylinder 405 may be formed by coating or impregnating a thermosetting heat-resistant resin after knitting the fibers as described above into a mesh and a cylinder.
As will be described later, the mesh fiber cylinder 405 has an outer diameter in an enlarged state that is substantially the same as an inner diameter of the base material 400 in a state in which the planar heating element 402 is fixed to the inner peripheral surface. Diameter or slightly larger. Further, the outer diameter when the diameter is reduced is formed to be smaller than the inner diameter of the base material 400 when the planar heating element 402 is fixed to the inner peripheral surface.

Next, a method for manufacturing the heat roller 240 using the mesh fiber cylinder 405 will be described.
Unlike the mesh-like spring cylinder 403 described in the first embodiment, the mesh-like fiber cylinder 405 does not have a self-expanding function, and the thermosetting heat-resistant resin is in an uncured state. Therefore, the diameter expansion state cannot be maintained as it is.
Therefore, in this embodiment, as shown in FIG. 11, in order to enlarge the diameter of the mesh fiber cylinder 405, a heat resistant tube 9 that can be expanded by introducing a medium is used.
The heat-resistant tube 9 is made of, for example, a heat-resistant and stretchable synthetic resin such as silicone, and expands by introducing a medium such as a gas or liquid, or a medium such as a foamable material. It is configured.

As shown in FIG. 11, the heat-resistant tube 9 is inserted into the mesh fiber cylinder 405 having a reduced diameter. Next, as shown in FIG. 12, the mesh fiber cylinder 405 in which the heat-resistant tube 9 is inserted is accommodated in the hollow portion of the substrate 400 as in the first embodiment.
Alternatively, as shown in FIG. 12, after the mesh fiber cylinder 405 in a reduced state is accommodated in the hollow portion of the base material 400, the heat-resistant tube 9 is inserted into the mesh fiber cylinder 405. It may be.

Next, as shown in FIG. 13, for example, a medium such as gas is introduced into the heat resistant tube 9, and the heat resistant tube 9 is expanded in the hollow portion of the base material 400. As a result, the diameter of the mesh fiber cylinder 405 is expanded, and the sheet heating element 402 is pressed against the inner peripheral surface of the substrate 400 by the mesh fiber cylinder 405. It arrange | positions so that it may follow the inner peripheral surface of.
The thermosetting heat-resistant resin of the mesh fiber cylinder 405 is cured by heating while maintaining this expanded state. Thereby, the mesh fiber cylinder 405 is cured in a state where the diameter is expanded, that is, in a state where the outer peripheral surface of the mesh fiber cylinder 405 is in close contact with the inner surface of the planar heating element 402.
After the mesh-like fiber cylinder 405 is cured, the medium is removed from the heat-resistant tube 9, and the heat-resistant tube 9 is taken out from the mesh-like fiber cylinder 405, so that as shown in FIG. 240 is formed.

As described above, according to the manufacturing method of the heat roller according to the present embodiment, the planar heating element 402 is fixed to the inner peripheral surface of the base material 400 of the heat roller 240 by a simple method, as in the first embodiment. can do.
Further, since the fixing member for fixing the planar heating element 402 is the mesh fiber cylinder 405 formed of the mesh cylinder as described above, the heat capacity of the fixing member can be reduced. The warm-up time of the heat roller 240 can be shortened.
Further, since the mesh fiber cylinder 405 has a higher thermal expansion than the base material 400 made of an aluminum pipe, the mesh fiber cylinder 405 is thermally expanded by energization of the planar heating element 402, Its diameter increases. Thereby, the planar heating element 402 can be more firmly fixed to the inner peripheral surface of the substrate 400.

The heat roller 240 manufactured by the manufacturing method according to this embodiment may be provided in the fixing device 4 instead of the heat roller 40 described in the first embodiment.
Further, the mesh-like fiber cylinders 405 used in the manufacturing method according to the present embodiment are the mesh-like spring cylinders 403 and 404 provided in the heat rollers 40 and 140 described in the first and second embodiments. You may make it provide further inside.

4 Fixing device 8 Restraint thread (restraint member)
9 Heat-resistant tube 40,140,240 Heat roller 41 Press roller 141 Heat-resistant insulating layer (base material)
400 Aluminum pipe (base material), base material 402 Planar heating element (heating element)
403 mesh spring cylinder (mesh cylinder)
404 Mesh spring cylinder (mesh cylinder, heating element)
405 Reticulated fiber cylinder (Reticulated cylinder)

Claims (6)

A method of manufacturing a heat roller used in a fixing device for fixing a toner image formed on a recording medium,
In a hollow portion of a hollow cylindrical base material, a mesh-like cylindrical body that can be expanded and contracted in the radial direction is accommodated in a state in which the diameter is reduced, and then the diameter of the mesh-shaped cylindrical body is increased to thereby form the mesh method for producing a heat roller, characterized in lock down the Jo cylinder outer circumferential side arranged a heating element is brought into close contact with the inner peripheral surface of the base material. In claim 1,
The mesh tube is a mesh spring tube formed of a spring material in a mesh and tube shape,
In a state where the reduced state of the diameter of the mesh spring cylinder is restrained by the restraining member, the mesh spring cylinder is accommodated in the hollow portion of the base material, and then the restrained state by the restraining member is released, and the mesh is recovered by an elastic restoring force. A method for manufacturing a heat roller, wherein the diameter of the cylindrical spring cylinder is enlarged. In claim 1,
The mesh-shaped cylinder is composed of a mesh-like fiber cylinder in which heat-resistant fibers containing an uncured thermosetting heat-resistant resin are formed into a mesh-like and cylindrical shape,
A heat-resistant tube that can be expanded by introduction of a medium is inserted into the mesh fiber cylinder, and is contained in the hollow portion of the base material in a state where the diameter of the mesh fiber cylinder is reduced, and then A method for producing a heat roller, wherein the heat-resistant tube is expanded to expand the diameter of the mesh fiber tube, and the thermosetting heat-resistant resin is cured by heating while maintaining the expanded state. In any one of Claims 1 thru | or 3,
Manufacturing of a heat roller, wherein the heating element comprises a planar heating element, and the planar heating element is fixed to the inner peripheral surface of the substrate by enlarging the diameter of the mesh tube. Method. A method of manufacturing a heat roller used in a fixing device for fixing a toner image formed on a recording medium,
The hollow portion of the base material of the hollow cylinder, after the reticulated tubular body as the heating element ing from the enlargement and reduction was obtained and electric resistance material radially, were housed in a state of reduced diameter, net-th A method of manufacturing a heat roller, comprising enlarging the diameter of a cylindrical tube and fixing the mesh tube to the inner peripheral surface of the substrate .   A fixing device comprising: a heat roller manufactured by the method for manufacturing a heat roller according to claim 1; and a press roller that elastically contacts the heat roller.

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