JP5465290B2 - Image heating device - Google Patents

Description

  The present invention relates to an image heating apparatus that heats an image on a recording material using a heating roller, and more particularly to an image heating apparatus having a heating unit that is rotatable with respect to the apparatus main body to open the heating roller.

  2. Description of the Related Art Conventionally, as an image heating apparatus that is used in an image forming apparatus such as a copying machine or a printer and heats an image on a recording material, a fixing device that heats and fixes the image on the recording material using a heating roller and a pressure roller. It has been known. In this fixing device, a heating roller and a pressure roller are provided separately in two upper and lower units that can be opened and closed for the maintenance of each roller and the processing of the recording material wound around the roller. Some units are configured to open and close two units depending on the situation.

  In the above-described fixing device, the heating roller is rotatably supported by the upper unit above the fixing device by holding and fixing a bearing disposed coaxially with the heating roller by a bearing holding member.

  In such a fixing device, when the fixing performance is deteriorated due to scratches on the outer peripheral surface of the heating roller or deterioration of durability, it is necessary to replace the heating roller. This heating roller reuses only the cored bar. However, as described above, the heating roller is fixed to the upper unit and is difficult to remove, so that the cored bar may be damaged during disassembly.

  Therefore, as in Patent Document 1, a fixing device has been proposed that is intended to be easily removed without scratching the core of the heating roller. In the fixing device of Patent Document 1, as a bearing holding member in which a bearing of a heating roller is fitted into the fitting opening of the upper unit, and further, one end is supported with respect to the upper unit and the other end is detachably engaged. The bearing is held by a bar-shaped elastic member.

Japanese Patent Laid-Open No. 8-04236 (FIGS. 1 and 2)

  However, the conventional configuration has the following problems.

  Normally, when performing the replacement operation of the heating roller, the image forming apparatus that has been operating until then is stopped and the removal operation is performed, but the heating roller may not be sufficiently cooled during the operation. Therefore, it is necessary to work in a state in which heat countermeasures are taken, such as using heat-resistant gloves at the time of removing the heating roller, and there is a problem that workability is impaired. Alternatively, it is necessary to wait until the heating roller is sufficiently cooled before removing it, and there is a problem that it takes more time to replace the heating roller than the actual working time.

  SUMMARY OF THE INVENTION An object of the present invention is to provide an image heating apparatus that can easily replace a heating roller without directly touching the heating roller.

In order to achieve the above object, the present invention comprises a heating roller, a bearing that rotatably supports the heating roller, and a holder that holds the bearing. In the image heating apparatus having a movable frame body, the holder can be removed by releasing a hook portion for fixing the heating roller to a groove portion having a U-shaped cross section of the frame body. And a stopper for stopping the rotation of the heating roller at a position where the heating roller can be placed on the holder .

  According to the present invention, the heating roller can be removed from the image heating apparatus together with the bearing without directly touching the heating roller, and the heating roller together with the bearing can be attached to the image heating apparatus. In addition, since the heating roller can be replaced without directly touching the heating roller, the heating roller replacement workability is not impaired, and the time required for the replacement operation is not increased. Work can be done.

Detailed explanation of image heating device Detailed perspective view of image heating device Operation explanatory diagram when replacing the heating roller of the image heating device Operation explanatory diagram when replacing the heating roller of the image heating device Operation explanatory diagram when replacing the heating roller of the image heating device Operation explanatory diagram when replacing the heating roller of the image heating device Operation explanatory diagram when replacing the heating roller of the image heating device

  Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the drawings. However, the dimensions, materials, shapes, and relative arrangements of the components described in the following embodiments should be appropriately changed according to the configuration of the apparatus to which the present invention is applied and various conditions. Therefore, unless specifically stated otherwise, the scope of the present invention is not intended to be limited thereto.

  The image heating apparatus will be described with reference to FIGS. Here, as an image heating apparatus, a fixing apparatus that heats and fixes a toner image transferred to a recording material in an image forming apparatus such as a printer or a copier will be described as an example.

  FIG. 1 is a detailed view of the fixing device. As shown in FIG. 1, the fixing device 30 has an upper fixing unit 1 on the upper side of the device and a lower fixing unit 2 on the lower side of the device that supports the upper fixing unit 1 so as to be openable and closable. The upper fixing unit 1 is a heating unit that is rotatable with respect to the lower fixing unit (apparatus main body) 2 so as to open a heating roller 3 described later.

  A hollow cylindrical heating roller 3 (heating member) supported at both ends by a bearing 5 so as to be rotationally driven is detachably attached to the upper fixing unit 1 as will be described later. Inside the heating roller 3, a heater 4 as a heat source is provided. The heating roller 3 is rotatably supported by a bearing 5 as a bearing member. The bearing 5 is provided coaxially with the heating roller 3. Further, a cleaning web (not shown) for cleaning the outer peripheral surface is pressed against the outer peripheral surface of the heating roller 3 by a web roller (not shown). Reference numeral 8 denotes a cover that covers the upper fixing unit 1, and 11 denotes a frame of the upper fixing unit 1.

  The lower fixing unit 2 includes an inlet guide 12 for guiding a recording material, a pressure roller (pressure member) 13 whose both ends are rotatably supported by bearings 14, and the pressure roller 13 in the direction of the heating roller 3. A biasing member 15 for biasing is attached. The biasing member 15 is swingable about the support shaft 17, biases the bearing 14 by a biasing spring 16, and biases the pressure roller 13 toward the heating roller 3. Reference numeral 19 denotes a frame of the lower fixing unit 2.

  The upper fixing unit 1 is supported so as to be openable and closable with respect to the lower fixing unit 2 around a support shaft 9. When the upper fixing unit 1 is in the closed state shown in FIG. 1, the fixing upper unit 1 is positioned and fixed with respect to the lower fixing unit 2 by inserting a fixing shaft (not shown) into the fixing portion 10.

  Next, with reference to FIG. 2, the support structure of the heating roller 3 in the upper fixing unit 1 will be described. FIG. 2 is a perspective view showing a support structure of the heating roller 3 in the upper fixing unit 1. As shown in FIG. 2, the frame 11 of the upper fixing unit 1 is provided with holding means 20 that detachably holds the bearing 5 attached coaxially with the heating roller 3 with respect to the upper fixing unit 1. Yes. The holding means 20 includes a holding member 21 and a pressing member 22 which will be described later.

  The holding member 21 contacts the bearing 5 and holds the bearing 5 in the upper fixing unit 1. The holding member 21 is configured to contact and hold both end surfaces of the bearing 5 in the axial direction. Here, the holding member 21 has a U-shaped cross section in a direction orthogonal to the roller rotation direction. As a result, the position of the bearing 5 is regulated by the holding member 21, the bearing 5 does not fall down due to the pressure contact or driven rotation of the heating roller 3 and the pressure roller 13, and vibration during driving can be prevented. The highly accurate sheet | seat conveyance property which becomes can be achieved. Further, the holding member 21 has an opening 21a that is open on the pressure contact portion side with the pressure roller 13, and the bearing 5 held by the holding member 21 is attached to and detached from the opening 21a.

  The pressing member (holder) 22 contacts the bearing 5 together with the holding member 21 to hold the bearing 5 in the upper fixing unit 1. The holding member 22 is provided so as to be rotatable with respect to the holding member 21 so as to open and close the opening 21 a of the holding member 21, and is provided detachably with respect to the holding member 21 while holding the bearing 5. Yes. This will be described in detail below.

  The holding member 22 has a holding portion 22 a that contacts the bearing 5 together with the holding member 21 to hold the bearing 5 in the upper fixing unit 1 and holds the bearing 5 detached from the holding member 21. Similar to the holding member 21 described above, the holding portion 22a of the pressing member 22 is configured to contact and hold both end surfaces of the bearing 5 in the axial direction. That is, the holding portion 22a also has a U-shaped cross section in a direction orthogonal to the roller rotation direction. Thereby, the bearing 5 does not fall down due to the pressure contact between the heating roller 3 and the pressure roller 13 or driven rotation, and vibration during driving can be prevented.

  Further, the pressing member 22 is provided with a connecting hook 23 as a connecting portion that is connected to the holding member 21 so as to be disengaged. The connection hook 23 is a hook portion for fixing the heating roller 3 to the upper fixing unit 1. The connection hook 23 is rotatably attached to the holding member 22 by a rotation shaft 25 and is always biased in the connection direction by a hook spring 24. The pressing member 22 is provided with an attaching / detaching portion 26 that can be attached to and detached from the holding member 21. The detachable portion 26 functions as a pivot point of the pressing member 22 when the connection of the connection hook 23 to the holding member 21 is released. That is, the pressing member 22 is attached to the holding member 21 by the attaching / detaching portion 26 so as to be rotatable and detachable. Further, the pressing member 22 stops its rotation at a position (position of the pressing member 22 shown in FIG. 4) where the heating roller 3 which can be removed by releasing the connecting hook 23 can be placed. It has a stopper (not shown).

  The holding member 21 has a positioning portion for connecting the upper fixing unit 1 and the lower fixing unit 2 and positioning and fixing the upper fixing unit 1 with respect to the lower fixing unit 2. Here, a support shaft 9 as a shaft portion serving as a rotation center of the upper fixing unit 1 with respect to the lower fixing unit 2 and a fixing portion 10 for releasably fixing the upper fixing unit 1 in the closed state to the lower fixing unit 2. However, it is the structure which functions as the said positioning part. That is, the positioning is performed directly by the holding member 21 that holds the heating roller 3 with respect to the lower fixing unit 2 having the pressure roller 13. Thereby, the heating roller 3 can be positioned with high accuracy with respect to the pressure roller 13 provided in the lower fixing unit 2, and high-accuracy sheet conveyance can be achieved.

  Next, replacement work of the heating roller 3 will be described. First, the removal of the heating roller 3 from the fixing device will be described. The fixing upper unit 1 including the heating roller 3 is opened around the support shaft 9 as shown in FIG. 3 by releasing the fixing of the fixing portion 10 that fixes the fixing upper and lower units 1 and 2 as described above. Can be rotated in the direction. When the upper fixing unit 1 is rotated in the opening direction around the support shaft 9, the heating roller 3 rotates integrally with the upper fixing unit 1 with the bearing 5 held by the holding means 20. Then, as shown in FIG. 3, the upper fixing unit 1 is opened with respect to the lower fixing unit 2.

  By rotating the connecting hook 23 in the direction of arrow A in FIG. 3 after the rotation, the connection with the holding member 21 is released, and the pressing member 22 can be separated from the holding member 21. After releasing the connection, the pressing member 22 is rotated in the opening direction around the attaching / detaching portion 26, so that the pressing member 22 is opened with respect to the holding member 21 as shown in FIG. Part 21a is opened. At this time, the rotation of the pressing member 22 is stopped at the position shown in FIG. 4 by the stopper (not shown) described above. The roller lower side surface B of the holding member 21 is provided with an inclination toward the opening 21a so that the bearing 5 together with the heating roller 3 is separated from the holding member 21 by its own weight in the direction of arrow C. Thereby, as shown in FIG. 5, the heating roller 3 automatically moves toward the opening 21 a together with the bearing 5. Then, the heating roller 3 stops when the bearing 5 that moves together is received by the holding portion 22a of the pressing member 22 that is first rotated and waiting in the open state. In other words, the holding member 22 in the open state also functions as a holding portion for holding the bearing 5 whose holding portion 22 a is detached from the holding member 21 by its own weight.

  Further, the pressing member 22 is provided so as to be detachable from the holding member 21. That is, the pressing member 22 is detachably mounted on the holding member 21 with an attaching / detaching portion 26 serving as a rotation fulcrum. For this reason, when the heating roller 3 is removed from the fixing upper unit 1, as shown in FIG. 6, the pressing member 22 is held in a state where the bearing 5 supporting the heating roller 3 is held on the pressing member 22. Remove from member 21. Accordingly, the heating roller 3 can be detached from the upper fixing unit 1 without directly touching the heating roller 3.

  On the other hand, when the heating roller 3 is attached to the upper fixing unit 1, as shown in FIG. 7, the heating roller 3 is placed on the holding portion 22a of the pressing member 22 so that both end faces of the bearing 5 are accommodated. Then, the attaching / detaching portion 26 of the pressing member 22 is attached to the holding member 21. Next, the pressing member 22 is rotated in the arrow D direction. By this operation, the bearing 5 attached to the heating roller 3 using the pressing member 22 and the holding member 21 as a guide guide moves together with the heating roller 3 in the direction of arrow E, and finally the connecting hook 23 of the pressing member 22 is held by the holding member 21. Concatenated with As a result, the bearing 5 is positioned and held on the upper fixing unit 1 by the holding means 20.

  As described above, the bearing 5 of the heating roller 3 can be detached from the holding member 21 by the rotation of the pressing member 22, and the holding member 22 is held in a state where the bearing 5 is held by the rotated pressing member 22. It can be removed from the member 21. In addition, the pressing member 22 can be attached to the holding member 21 of the upper fixing unit 1 while the bearing 5 of the heating roller 3 is held by the pressing member 22 removed from the holding member 21. Accordingly, the heating roller 3 together with the bearing 5 can be removed from the fixing device without directly touching the heating roller 3, and the heating roller 3 together with the bearing 5 can be attached to the fixing device. Further, since the heating roller 3 can be replaced without directly touching the heating roller 3, the heating roller 3 can be easily replaced without impairing the replacement workability or taking much time for the replacement operation. The roller 3 can be exchanged.

  In the above-described embodiment, the heat fixing apparatus mounted on the image forming apparatus such as a printer or a copying machine is exemplified as the image heating apparatus. However, the present invention is not limited to such a heat fixing apparatus, and can be applied to, for example, a gloss applying apparatus that improves the gloss of an image formed on a recording material. Further, the present invention can be applied to an image heating apparatus that is not mounted on the image forming apparatus.

B ... Roller lower side 1 ... Upper fixing unit 2 ... Lower fixing unit 3 ... Heating roller 4 ... Heating heater 5 ... Bearing 8 ... Cover 9 ... Support shaft 10 ... Fixed portion 11 ... Frame body 12 ... Inlet guide 13 ... Pressure roller DESCRIPTION OF SYMBOLS 14 ... Bearing 15 ... Energizing member 16 ... Energizing spring 17 ... Supporting shaft 19 ... Frame body 20 ... Holding means 21 ... Holding member 21a ... Opening part 22 ... Holding member 22a ... Holding part 23 ... Connecting hook 24 ... Hook spring 25 ... Rotating shaft 26 ... Detachable part 30 ... Fixing device

Claims (1)

An image heating apparatus comprising: a heating roller; a bearing that rotatably supports the heating roller; and a holder that holds the bearing; and a frame that is rotatable with respect to the apparatus main body to open the heating roller. ,
The holder places on the holder a hook portion for fixing the heating roller to a groove portion having a U-shaped cross section of the frame body, and the heating roller that is removable by releasing the hook portion. And a stopper for stopping the rotation at a position where the image can be moved.

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