JP2014191136A - Fixing device and image forming apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To shorten a first print time to reduce power consumption and cost.SOLUTION: A fixing device of the present invention includes a heating member 21 that rotates around a predetermined rotation shaft A, a heat source 36 that is provided inside the heating member 21, and attachment members 44 and 50 that are attached to ends of the heating member 21. The attachment members 44 and 50 respectively include lid parts 47 and 52 that are provided to cover openings 35a and 35b formed at the ends of the heating member 21, and one or a plurality of protrusions 48, 53, and 54 that protrude from the lid parts 47 and 52 toward the inside in the rotation shaft A direction, where spaces S1 to S3 opening toward the inside in the rotation shaft A direction are formed at least one of between the heating member 21 and protrusions 48 and 54 and between the plurality of protrusions 53 and 54.

Description

  The present invention relates to a fixing device that fixes a toner image on a sheet, and an image forming apparatus including the fixing device.

  Conventionally, an electrophotographic image forming apparatus such as a copying machine or a printer is provided with a fixing device for fixing a toner image on a sheet.

  The fixing device includes, for example, a heating member (see, for example, “Heat Roller 1” in Patent Document 1), and a heat source provided in the heating member (see, for example, “Halogen Lamp 3” in Patent Document 1). And a mounting member (see, for example, “Bearings 11a and 11b” and “Gear 12” in Patent Document 1) mounted on an end portion of the heating member. And it is comprised so that a heating member may be heated from the inside with a heat source.

JP 2011-169930 A

  In the fixing device configured as described above, there is a problem that heat escapes from the inside of the heating member to the outside through the openings formed at both ends of the heating member. If the heat escapes in this way, the heating member becomes difficult to warm up, so that it takes time to heat the heating member to a certain temperature by the heat source, and the first print time (time until the first printing is completed) is increased. There is a problem of becoming longer. Further, when the time until the heating member is heated to a certain temperature by the heat source becomes longer, the operation time of the heat source becomes longer, which causes a problem that power consumption increases. Further, when heat escapes from the inside of the heating member to the outside as described above, the inside of the image forming apparatus is warmed by the escaped heat. As a result, it is necessary to take measures to suppress the increase in the in-machine temperature, and there is a problem that the cost increases.

  In view of the above circumstances, an object of the present invention is to shorten the first print time and reduce power consumption and cost.

  The fixing device of the present invention includes a heating member that rotates about a predetermined rotation axis, a heat source provided in the heating member, and a mounting member that is mounted on an end of the heating member. The member includes a lid portion provided so as to cover an opening formed at the end portion of the heating member, and one or a plurality of projection portions projecting inward in the rotation axis direction from the lid portion. A space opened toward the inner side in the rotational axis direction is formed between at least one of the heating member and the protrusions or between the plurality of protrusions.

  By adopting such a configuration, it is possible to suppress heat from escaping from the inside of the heating member to the outside through the opening. Therefore, the heating member is easily warmed, and the time until the heating member is heated to a constant temperature by the heat source can be shortened. Accordingly, the first print time can be shortened, and the convenience of the fixing device can be improved. In addition, since the time until the heating member is heated to a constant temperature by the heat source is shortened, the operation time of the heat source can be shortened, power consumption can be reduced, and energy saving can be achieved. Furthermore, since heat does not escape from the inside of the heating member to the outside via the opening, the inside of the image forming apparatus is not warmed by the escaped heat. This eliminates the need for a measure for suppressing the increase in the in-machine temperature, leading to cost reduction.

  Moreover, the heat inside a heating member can be stored in said space. For this reason, it is possible to more effectively suppress the escape of heat from the inside of the heating member to the outside.

  An inner peripheral surface of the protrusion may be provided so as to be separated from the heat source toward the inner side in the rotation axis direction.

  By employ | adopting such a structure, the heat which a heat source generate | occur | produces can be induced | guided | derived to the inside of a heating member with the internal peripheral surface of a protrusion part. For this reason, it is possible to more effectively suppress the escape of heat from the inside of the heating member to the outside.

  A gap may be formed between the mounting member and the heat source, and the gap may be set to 2 mm or less.

  By forming the gap between the mounting member and the heat source as described above, it is possible to suppress an excessive increase in the temperature of the mounting member due to the heat generated by the heat source. On the other hand, by setting the gap to 2 mm or less, it is possible to suppress heat from escaping more than necessary from the inside of the heating member to the outside.

  The heat source includes a heating element, a tube having an accommodating part for accommodating the heating element, and a sealing part for sealing both ends of the accommodating part in the rotation axis direction, and the sealing The portion may be disposed on the outer side in the rotational axis direction than the mounting member.

  By employ | adopting such a structure, it can suppress that the temperature of a sealing part rises too much. Therefore, it is possible to suppress the deterioration of the sealing portion and extend the life of the heat source.

  A housing for accommodating the heating member may be further provided, and the mounting member may be fixed to the housing and rotatably support the heating member.

  By adopting such a configuration, the number of parts can be reduced as compared with the case where the member that rotatably supports the heating member and the mounting member are separate parts.

  The housing may further include a housing for accommodating the heating member, and the mounting member may be rotatably supported by the housing and may rotate integrally with the heating member.

  By employ | adopting such a structure, abrasion of the edge part of a heating member and a mounting member can be suppressed.

  A drive gear connected to a drive source may be further provided, and the mounting member may include a driven gear that meshes with the drive gear, and may rotate integrally with the heating member.

  By adopting such a configuration, the number of parts can be reduced as compared with the case where the member that transmits the driving force of the driving source to the heating member and the mounting member are separate parts.

  The mounting member may have a flat plate shape and may be fitted to an inner periphery of the end portion of the heating member.

  By employ | adopting such a structure, the opening part formed in the edge part of a heat roller can be covered with a simple structure.

  The image forming apparatus of the present invention includes any one of the fixing devices described above.

  According to the present invention, the first print time can be shortened, and the power consumption and cost can be reduced.

1 is a schematic diagram illustrating an outline of a printer according to a first embodiment of the present invention. 1 is a cross-sectional view illustrating a fixing device of a printer according to a first embodiment of the present invention. FIG. 3 is a side cross-sectional view showing a heat roller and its peripheral part in the printer fixing device according to the first embodiment of the present invention. FIG. 6 is a side sectional view showing a heat roller and its peripheral part in a fixing device for a printer according to a second embodiment of the present invention. FIG. 10 is a side sectional view showing a heat roller and its peripheral part in a fixing device for a printer according to a third embodiment of the present invention.

<First Embodiment>
First, the overall configuration of a printer 1 as an image forming apparatus will be described with reference to FIG.

  The printer 1 includes a box-shaped printer main body 2, a paper feed cassette 3 for storing paper (not shown) is provided at the bottom of the printer main body 2, and a paper discharge tray is provided at the upper end of the printer main body 2. 4 is provided.

  An exposure unit 5 composed of a laser scanning unit (LSU) is arranged at the upper right part of the printer main body 2, and an image forming unit 6 is provided at the left part of the printer main body 2. The image forming unit 6 is rotatably provided with a photosensitive drum 7 serving as an image carrier. Around the photosensitive drum 7, a charger 8 and a developing unit 10 connected to a toner container 9 are provided. The transfer roller 11 and the cleaning device 12 are arranged along the rotation direction of the photosensitive drum 7 (see arrow X in FIG. 1).

  A paper transport path 13 is provided on the left portion of the printer main body 2 from below to above. A paper feed unit 14 is provided at the upstream end of the conveyance path 13, and a transfer unit 15 configured by the photosensitive drum 7 and the transfer roller 11 is provided at a middle portion of the conveyance path 13, and a downstream part of the conveyance path 13. Is provided with a fixing device 16. On the left side of the transport path 13, a reverse path 17 for duplex printing is provided.

  Next, an image forming operation of the printer 1 having such a configuration will be described.

  When the printer 1 is turned on, various parameters are initialized, and initial setting such as temperature setting of the fixing device 16 is executed. Then, when image data is input from a computer or the like connected to the printer 1 and an instruction to start printing is given, an image forming operation is executed as follows.

  First, after the surface of the photosensitive drum 7 is charged by the charger 8, exposure corresponding to image data is performed on the photosensitive drum 7 by laser light from the exposure device 5 (see arrow P in FIG. 1). Then, an electrostatic latent image is formed on the surface of the photosensitive drum 7. Next, the developing unit 10 develops the electrostatic latent image into a toner image with the toner supplied from the toner container 9.

  On the other hand, the sheet taken out from the sheet cassette 3 by the sheet feeding unit 14 is conveyed to the transfer unit 15 in synchronization with the above-described image forming operation, and the toner image on the photosensitive drum 7 is transferred to the sheet by the transfer unit 15. Is transcribed. The sheet on which the toner image has been transferred is conveyed downstream in the conveyance path 13 and enters the fixing device 16 where the toner image is fixed on the sheet. The sheet on which the toner image is fixed is discharged from the downstream end of the transport path 13 to the discharge tray 4. The toner remaining on the photosensitive drum 7 is collected by the cleaning device 12.

  Next, the overall configuration of the fixing device 16 will be described with reference to FIG. Hereinafter, for convenience of explanation, the front side of the sheet in FIG. 2 is defined as the front side (front side) of the fixing device 16.

  As shown in FIG. 2, the fixing device 16 includes a housing 20 having a box shape, a heat roller 21 (heating member) accommodated in a lower right portion of the housing 20, and the housing 20 facing the heat roller 21. The press roller 22 accommodated in the left side, the cover member 23 covering the upper side of the housing 20, and a pair of upper and lower discharge rollers 24 provided on the right end side of the cover member 23 are mainly configured.

  A heat roller accommodating portion 25 is formed on the right side portion of the housing 20. A press roller accommodating portion 26 is formed on the left side portion of the housing 20. A discharge switch 27 is provided on the upper right side of the press roller accommodating portion 26. The discharge switch 27 is configured to rotate around the fulcrum portion 28.

  The heat roller 21 is accommodated in the heat roller accommodating portion 25 of the housing 20. The heat roller 21 has a long shape in the front-rear direction. The heat roller 21 is, for example, a cylindrical core material made of metal such as aluminum or iron, an elastic layer that is provided around the core material and made of silicon rubber, etc., and covers the elastic layer, and fluorine such as PFA. And a release layer made of resin.

  A separation claw 30 is provided on the upper side of the heat roller 21 (downstream side in the paper conveyance direction). The separation claw 30 is in contact with the outer peripheral surface of the heat roller 21 by a biasing force of a biasing body (not shown). Thereby, the paper can be separated from the outer peripheral surface of the heat roller 21 by the separation claw 30.

  The press roller 22 is accommodated in the press roller accommodating portion 26 of the housing 20. The press roller 22 has a long shape in the front-rear direction. The press roller 22 is, for example, a cylindrical core material made of metal such as aluminum or iron, an elastic layer that is provided around the core material and made of silicon rubber, and the like, and covers the elastic layer, and fluorine such as PFA. And a release layer made of resin.

  The press roller 22 is pressed against the heat roller 21 by a biasing force of a biasing member (not shown), and a fixing nip 31 is formed between the heat roller 21 and the press roller 22. The sheet passes through the fixing nip 31 so that the toner image is fixed on the sheet. The press roller 22 is configured to be driven to rotate in the direction opposite to that of the heat roller 21 as the heat roller 21 rotates (see an arrow in FIG. 2).

  The cover member 23 is located on the uppermost part of the fixing device 16. The cover member 23 includes a lower member 32 and an upper member 33 that covers the upper side of the lower member 32. The lower member 32 and the upper member 33 are connected to each other.

  The upper discharge roller 24 is supported by the roller shaft 34. A right end portion of the cover member 23 is rotatably supported on the roller shaft 34. The lower discharge roller 24 is in pressure contact with the upper discharge roller 24.

  Next, the heat roller 21 and its peripheral part will be described in more detail with reference to FIG. 3 indicates the front side (front side) of the fixing device 16 (the same applies to FIGS. 4 and 5).

  As shown in FIG. 3, an opening 35 a is formed at the front end of the heat roller 21, and an opening 35 b is formed at the rear end of the heat roller 21. The heat roller 21 rotates about a rotation axis A extending in the front-rear direction. That is, in this embodiment, the front-rear direction is the rotation axis direction of the heat roller 21.

  A heater 36 (heat source) is installed in the heat roller 21. The heater 36 includes a filament 37 (heating element) and a glass tube 38 (tube body) that covers the filament 37.

  The filament 37 is made of, for example, tungsten. The filament 37 has a coil shape.

  The glass tube 38 is made of, for example, quartz glass. The glass tube 38 extends in the front-rear direction. The glass tube 38 includes a housing portion 40 that houses the filament 37, sealing portions 41a and 41b (front side sealing portion 41a and rear side sealing portion 41b) that are provided on the outside in the front-rear direction of the housing portion 40, and And mounting portions 42a and 42b (front mounting portion 42a and rear mounting portion 42b) provided outside the sealing portions 41a and 41b in the front-rear direction. A halogen gas is enclosed in the accommodating portion 40 together with the filament 37. That is, the heater 36 is a so-called “halogen heater”. The front side sealing portion 41 a seals the front end portion of the accommodating portion 40, and the rear side sealing portion 41 b seals the rear end portion of the accommodating portion 40. A screw hole 43 is formed in each of the attachment portions 42a and 42b, and the heater 36 is fixed to the housing 20 (see FIG. 2) by a screw (not shown) penetrating the screw hole 43.

  A first mounting member 44 is mounted on the front end portion of the heat roller 21. The first mounting member 44 is disposed on the rear side (inward in the front-rear direction) of the front sealing portion 41 a of the glass tube 38 of the heater 36. In other words, the sealing portion 41 a on the front side of the glass tube 38 of the heater 36 is disposed on the front side (outside in the front-rear direction) of the first mounting member 44.

  The first mounting member 44 includes a holding portion 45, a fixing portion 46 protruding from the front portion of the holding portion 45 toward the outer diameter side, and a front end portion (end portion on the outer side in the front-rear direction) of the holding portion 45 from the front end portion to the inner diameter side. A lid portion 47 that is bent toward the outside, and a protruding portion 48 that projects from the inner diameter side end portion of the lid portion 47 toward the rear side (inward in the front-rear direction).

  The holding part 45 has a cylindrical shape. The inner peripheral surface of the holding unit 45 is in contact with the outer peripheral surface of the heat roller 21. The holding | maintenance part 45 is supporting the front-end part of the heat roller 21 rotatably. That is, the first mounting member 44 is a slide bearing.

  The fixing portion 46 has a flat plate shape. The fixing portion 46 is provided perpendicular to the front-rear direction. The fixed portion 46 is fixed to the housing 20 (see FIG. 2).

  The lid portion 47 has an annular shape. The lid 47 is provided perpendicular to the front-rear direction. The lid 47 is provided so as to cover the opening 35 a formed at the front end of the heat roller 21. An annular gap is formed between the inner diameter side end of the lid portion 47 (the portion of the lid portion 47 that protrudes to the innermost diameter side) and the glass tube 38 of the heater 36, and the width of this gap g1 is set to 2 mm or less.

  The protruding portion 48 has a cylindrical shape and is provided so as to cover the front end portion of the accommodating portion 40 of the glass tube 38. A space S <b> 1 is formed between the heat roller 21 and the protrusion 48. The space S1 is opened toward the rear side (inward in the front-rear direction).

  The inner peripheral surface of the lid portion 47 and the inner peripheral surface of the projecting portion 48 are tapered in diameter toward the rear side (front and rear direction inner side), and the glass tube 38 faces the rear side (front and rear direction inner side). It is separated from the accommodating part 40.

  A second mounting member 50 is mounted on the rear end portion of the heat roller 21. The second mounting member 50 is disposed on the front side (inward in the front-rear direction) of the sealing portion 41 b on the rear side of the glass tube 38 of the heater 36. In other words, the sealing portion 41 b on the rear side of the glass tube 38 of the heater 36 is arranged on the rear side (outside in the front-rear direction) with respect to the second mounting member 50.

  The second mounting member 50 includes a holding portion 51, a lid portion 52 bent toward the inner diameter side from the rear end portion (end portion on the outer side in the front-rear direction) of the holding portion 51, and an inner diameter side end portion of the lid portion 52. A first projecting portion 53 projecting toward the front side (front and rear direction inner side), and a second projecting portion 54 projecting from the radial center of the lid portion 52 toward the front side (front and rear direction inner side). .

  The holding part 51 has a cylindrical shape. The inner peripheral surface of the holding part 51 is fixed to the outer peripheral surface of the heat roller 21. A driven gear 55 is provided on the outer peripheral surface of the holding portion 51. The driven gear 55 meshes with the drive gear 57. The drive gear 57 is connected to a drive motor 58 (drive source) and is configured to rotate by a drive force from the drive motor 58.

  The lid portion 52 has an annular shape. The lid part 52 is provided perpendicular to the front-rear direction. The lid part 52 is provided so as to cover the opening part 35 b formed at the rear end part of the heat roller 21. A gap is formed between the end portion on the inner diameter side of the lid portion 52 (the portion of the lid portion 52 that protrudes to the innermost diameter side) and the glass tube 38 of the heater 36, and the width g2 of the gap is It is set to 2 mm or less.

  The first projecting portion 53 has a cylindrical shape and is provided so as to cover the rear end portion of the accommodating portion 40 of the glass tube 38.

  The inner peripheral surface of the lid portion 52 and the inner peripheral surface of the first projecting portion 53 are increased in diameter toward the front side (front and rear direction inner side), and the glass tube 38 faces the front side (front and rear direction inner side). It is separated from the accommodating part 40.

  The second protrusion 54 has a cylindrical shape. A curved surface 59 is formed on the inner diameter side portion of the front end portion (end portion on the inner side in the front-rear direction) of the second protrusion 54. A space S <b> 2 is formed between the first protrusion 53 and the second protrusion 54. The space S2 is opened toward the front side (inward in the front-rear direction). A space S3 is formed between the heat roller 21 and the second protrusion 54. The space S3 is opened toward the front side (front and rear direction inner side).

  A cylindrical bearing member 60 is attached to the rear portion of the heat roller 21. The bearing member 60 is disposed adjacent to the second mounting member 50 on the front side of the second mounting member 50. The bearing member 60 is fixed to the housing 20. The bearing member 60 rotatably supports the rear part of the heat roller 21. That is, the bearing member 60 is a sliding bearing.

  In the configuration as described above, when the toner image is fixed on the paper, the drive gear 57 is rotated by the drive motor 58. When the drive gear 57 is thus rotated, this rotation is transmitted to the second mounting member 50, and the second mounting member 50 rotates. When the second mounting member 50 rotates as described above, the heat roller 21 fixed to the second mounting member 50 rotates integrally with the second mounting member 50.

  Further, when fixing the toner image on the paper, the heater 36 is energized and the filament 37 of the heater 36 is heated. Thereby, the heat roller 21 is heated from the inside by the heater 36.

  At this time, in the present embodiment, the opening 35 a of the heat roller 21 is covered with the lid 47 of the first mounting member 44 and the opening 35 b of the heat roller 21 is the lid of the second mounting member 50 as described above. 52. Therefore, it is possible to prevent heat from escaping from the inside of the heat roller 21 to the outside through the openings 35a and 35b. Therefore, the heat roller 21 is easily warmed, and the time until the heat roller 21 is heated to a constant temperature by the heater 36 can be shortened. Accordingly, the first print time can be shortened, and the convenience of the fixing device 16 can be improved.

  Moreover, since the time until the heat roller 21 is heated to a constant temperature by the heater 36 is shortened, the operation time of the heater 36 can be shortened, and power consumption can be reduced to save energy. Furthermore, since heat does not escape from the inside of the heat roller 21 to the outside via the openings 35a and 35b, the inside of the printer 1 is not warmed by the escaped heat. This eliminates the need for a measure for suppressing the increase in the in-machine temperature, leading to cost reduction.

  In addition, a space S1 is formed between the heat roller 21 and the protrusion 48 of the first mounting member 44, and a space S2 is formed between the first protrusion 53 and the second protrusion 54 of the second mounting member 50. A space S3 is formed between the heat roller 21 and the second projecting portion 54 of the second mounting member 50. By employ | adopting such a structure, the heat inside the heat roller 21 can be stored in said space S1-S3. Therefore, it is possible to more effectively suppress heat from escaping from the inside of the heat roller 21 to the outside.

  Further, the inner peripheral surface of the protrusion 48 of the first mounting member 44 and the inner peripheral surface of the first protrusion 53 of the second mounting member 50 are separated from the housing portion 40 of the glass tube 38 toward the inner side in the front-rear direction. Is provided. By adopting such a configuration, the heat generated by the heater 36 is heated by the inner peripheral surface of the protrusion 48 of the first mounting member 44 and the inner peripheral surface of the first protrusion 53 of the second mounting member 50. It can be guided to the inside of the roller 21 (see arrow B in FIG. 3). Therefore, it is possible to more effectively suppress heat from escaping from the inside of the heat roller 21 to the outside.

  Further, between the end portion on the inner diameter side of the lid portion 47 of the first mounting member 44 and the glass tube 38 of the heater 36, the end portion on the inner diameter side of the lid portion 52 of the second mounting member 50, and the glass tube 38 of the heater 36. A gap is formed between each of them. Therefore, it is possible to prevent the temperature of the first mounting member 44 and the second mounting member 50 from excessively rising due to the heat generated by the heater 36. On the other hand, by setting the gap to 2 mm or less, it is possible to prevent heat from escaping more than necessary from the inside of the heat roller 21 to the outside.

  In addition, each of the sealing portions 41a and 41b of the glass tube 38 of the heater 36 has a specified heat resistant temperature such as 300 degrees or less, and when the heat resistant temperature is exceeded, the sealing portions 41a and 41b are It deteriorates and the life of the heater 36 is shortened. However, the sealing portion 41a on the front side of the glass tube 38 of the heater 36 is disposed on the front side (front and rear direction outside) of the first mounting member 44, and the sealing portion 41b on the rear side of the glass tube 38 of the heater 36 is It is arranged behind the second mounting member 50 (outside in the front-rear direction). Therefore, it is possible to suppress the temperature of each sealing portion 41a, 41b from rising excessively, suppress deterioration of each sealing portion 41a, 41b, and extend the life of the heater 36.

  Moreover, the 1st mounting member 44 is being fixed to the housing 20, and is supporting the heat roller 21 rotatably. Therefore, the number of parts can be reduced as compared with the case where the member that rotatably supports the heat roller 21 and the first mounting member 44 are separate parts.

  The second mounting member 50 includes a driven gear 55 that meshes with the drive gear 57 and is configured to rotate integrally with the heat roller 21. Therefore, the number of parts can be reduced compared to the case where the member that transmits the driving force of the drive motor 58 to the heat roller 21 and the second mounting member 50 are separate parts.

  In the present embodiment, the case where the first mounting member 44 and the second mounting member 50 are mounted on both front and rear ends of the heat roller 21 has been described. On the other hand, in another different embodiment, a mounting member may be mounted only on one end of a heating member such as the heat roller 21.

  In the present embodiment, the case where the heat roller 21 is a heating member has been described. On the other hand, in another different embodiment, the fixing belt may be a heating member.

  In the present embodiment, the case where a so-called “halogen heater” is used as a heat source has been described. On the other hand, in other different embodiments, other heat sources such as ceramic heaters and IH coils may be used.

  In this embodiment, the case where the configuration of the present invention is applied to the printer 1 has been described. However, in another different embodiment, the configuration of the present invention is applied to other image forming apparatuses such as a copying machine, a facsimile machine, and a multifunction machine. It is also possible.

<Second Embodiment>
Next, a fixing device 16 according to a second embodiment of the present invention will be described with reference to FIG. In addition, about the part similar to 1st Embodiment, the number same as 1st Embodiment is attached | subjected to FIG. 4, and description is abbreviate | omitted.

  A first mounting member 62 is mounted on the front end portion of the heat roller 21. The first mounting member 62 is formed of, for example, a synthetic resin having heat insulation properties.

  The first mounting member 62 includes a holding portion 63, a locking portion 64 that protrudes from the front end portion (end portion on the outer side in the front-rear direction) of the holding portion 63 toward the outer diameter side, and the front end portion (front-rear direction) of the holding portion 63. A lid portion 65 that is bent toward the inner diameter side from the outer end portion; and a protruding portion 66 that projects from the inner diameter side end portion of the lid portion 65 toward the rear side (inward in the front-rear direction). . About the structure of the cover part 65 and the protrusion part 66, since it is the same as that of the structure of the cover part 47 and the protrusion part 48 in 1st Embodiment, description is abbreviate | omitted.

  The holding part 63 has a cylindrical shape. The inner peripheral surface of the holding part 63 is fixed to the outer peripheral surface of the heat roller 21. A bearing 67 is attached to the outer periphery of the holding portion 63, and the first mounting member 62 is rotatably supported by the housing 20 (see FIG. 2) via the bearing 67.

  The locking part 64 has an annular shape, for example. The locking portion 64 is in contact with the bearing 67 and locks the bearing 67.

  A cylindrical bearing member 68 is attached to the rear portion of the heat roller 21. The bearing member 68 is made of, for example, a synthetic resin having heat insulation properties. The bearing member 68 is disposed adjacent to the second mounting member 50 on the front side of the second mounting member 50. The inner peripheral surface of the bearing member 68 is fixed to the outer peripheral surface of the heat roller 21. A bearing 69 is attached to the outer periphery of the bearing member 68, and the bearing member 68 is rotatably supported by the housing 20 (see FIG. 2) via the bearing 69.

  In the above-described configuration, when fixing the toner image on the paper, the heat roller 21 is rotated as in the first embodiment. When the heat roller 21 is rotated in this way, the first mounting member 62 and the bearing member 68 fixed to the heat roller 21 also rotate integrally with the heat roller 21. Therefore, wear of the heat roller 21, the first mounting member 62, and the bearing member 68 can be suppressed.

<Third Embodiment>
Next, a fixing device 16 according to a third embodiment of the present invention will be described with reference to FIG. In addition, about the part similar to 1st Embodiment, the same number as 1st Embodiment is attached | subjected to FIG. 5, and description is abbreviate | omitted.

  A bearing member 72 is attached to the front end portion of the heat roller 21. The bearing member 72 includes a holding portion 73 and a fixing portion 74 that protrudes from the front portion of the holding portion 73 to the outer diameter side.

  The holding part 73 has a cylindrical shape. The inner peripheral surface of the holding unit 73 is in contact with the outer peripheral surface of the heat roller 21. The holding | maintenance part 73 is supporting the front-end part of the heat roller 21 rotatably. That is, the bearing member 72 is a sliding bearing.

  The fixing portion 74 has a flat plate shape. The fixing portion 74 is provided perpendicular to the front-rear direction. The fixed portion 74 is fixed to the housing 20 (see FIG. 2).

  A first mounting member 75 is mounted on the front end portion of the heat roller 21. The first mounting member 75 is provided so as to cover the opening 35 a formed at the front end of the heat roller 21. The first mounting member 75 has an annular shape. The first mounting member 75 is formed of a flat metal plate. For example, a SUS plate having a thickness of 0.25 mm can be used as the sheet metal. The end portion on the outer diameter side of the first mounting member 75 is fitted to the inner periphery of the front end portion of the heat roller 21. A gap is formed between the inner diameter side end of the first mounting member 75 (the portion of the first mounting member 75 that protrudes to the innermost diameter side) and the glass tube 38 of the heater 36. The width g3 is set to 2 mm or less.

  In the present embodiment, as described above, the end portion on the outer diameter side of the flat first mounting member 75 is fitted to the inner periphery of the front end portion of the heat roller 21. By adopting such a configuration, the opening 35a of the heat roller 21 can be covered with a simple configuration.

1 Printer (image forming device)
16 Fixing device 20 Housing 21 Heat roller (heating member)
35a, 35b Opening 36 Heater (heat source)
37 Filament (heating element)
38 Glass tube
40 housing parts 41a, 41b sealing part 44 first mounting member 47 lid part (first mounting member)
48 Protrusion (first mounting member)
50 Second mounting member 52 Lid (second mounting member)
53 1st protrusion 54 2nd protrusion 55 Follower gear 57 Drive gear 58 Drive motor (drive source)
62 First mounting member 65 Lid (first mounting member)
66 Projection (first mounting member)
75 First mounting member A Rotating shaft S1 space S2 space S3 space

Claims (9)

A heating member that rotates about a predetermined rotation axis;
A heat source provided in the heating member;
A mounting member mounted on an end of the heating member,
The mounting member is
A lid provided to cover an opening formed at the end of the heating member;
One or a plurality of protrusions protruding from the lid portion toward the inner side in the rotation axis direction,
A fixing device, wherein a space opened toward the inner side in the rotational axis direction is formed between at least one of the heating member and the protrusions or between the plurality of protrusions.   The fixing device according to claim 1, wherein an inner peripheral surface of the protruding portion is provided so as to be separated from the heat source toward an inner side in the rotation axis direction.   The fixing device according to claim 1, wherein a gap is formed between the mounting member and the heat source, and the gap is set to 2 mm or less. The heat source is
A heating element;
A tubular body having a housing portion that houses the heating element and a sealing portion that seals both ends of the housing portion in the rotation axis direction;
The fixing device according to claim 1, wherein the sealing portion is disposed on the outer side in the rotation axis direction than the mounting member. A housing for accommodating the heating member;
The fixing device according to claim 1, wherein the mounting member is fixed to the housing and rotatably supports the heating member. A housing for accommodating the heating member;
The fixing device according to claim 1, wherein the mounting member is rotatably supported by the housing and rotates integrally with the heating member. A drive gear connected to the drive source;
The fixing device according to claim 1, wherein the mounting member includes a driven gear that meshes with the drive gear, and rotates integrally with the heating member.   The fixing device according to claim 1, wherein the mounting member has a flat plate shape and is fitted to an inner periphery of the end portion of the heating member.   An image forming apparatus comprising the fixing device according to claim 1.

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