JP2020197585A - Fixing device and image forming apparatus - Google Patents

Abstract

To provide a fixing device that can prevent a heater from coming off from a heater holding member, and an image forming apparatus.SOLUTION: A fixing device 12 comprises: a fixing belt 70; and a heating unit 30. The heating unit 30 faces an inner peripheral surface of the fixing belt 70. The heating unit 30 includes a heater 22, a first holding member 20, and regulation members 24. The heater 22 heats the fixing belt 70. The first holding member 20 is attached with the heater 22. The regulation members 24 are each attached with the first holding member 20 attached with the heater 22 while surrounding the first holding member, so as to regulate the heater from moving with respect to the first holding member 20.SELECTED DRAWING: Figure 2

Description

The present invention relates to a fixing device and an image forming device.

A heating film type fixing device mounted on an electrophotographic image forming device is known. For example, the fixing device described in Patent Document 1 has a fixing assembly and a pressure roller that presses the fixing assembly to form a fixing nip portion. The fixing assembly has a tubular fixing film, a heater that contacts the inner surface of the fixing film, a heat insulating holder that holds the heater, and a metal stay that presses the heat insulating holder against a pressure roller. The thermistor is provided in the heat insulating holder and is contact-arranged with the heat conductive member at a predetermined pressure through the through hole of the heat insulating holder. The heat conductive member is sandwiched between the heater and the heat insulating holder and held by the heat insulating holder.

JP-A-2017-97143

However, in the fixing device described in Patent Document 1, since the metal stay presses the thermistor provided in the heat insulating holder with a predetermined pressure, there is a problem that the heater is easily disengaged from the heat insulating holder (heater holding portion).

The present invention has been made in view of the above problems, and an object of the present invention is to provide a fixing device and an image forming device capable of suppressing the heater from coming off from the first holding member.

The fixing device according to the present invention includes a fixing belt and a heating unit. The heating portion faces the inner peripheral surface of the fixing belt. The heating unit includes a heater, a first holding member, and a regulating member. The heater heats the fixing belt. The first holding member is equipped with the heater. The restricting member surrounds and mounts the first holding member to which the heater is mounted, and restricts the heater from moving with respect to the first holding member.

The image forming apparatus according to the present invention includes the fixing apparatus described above and an image forming unit. The image forming portion forms a toner image on the sheet. The fixing device fixes the toner image on the sheet.

According to the fixing device and the image forming device of the present invention, it is possible to prevent the heater from coming off from the first holding member.

It is a figure which shows the image forming apparatus which includes the fixing apparatus which concerns on embodiment of this invention. It is a perspective view which looked at the fixing device which concerns on this embodiment from the diagonally upward direction. (A) and (b) are external perspective views of the regulation member used in the fixing device according to this embodiment. (A) and (b) are diagrams showing specific examples of regulatory members used in the fixing device according to the present embodiment. It is a figure which shows the specific example of the regulation member used in the fixing device which concerns on this embodiment. It is a figure which shows the specific example of the regulation member used in the fixing device which concerns on this embodiment. It is a figure which shows the specific example of the regulation member used in the fixing device which concerns on this embodiment. It is a figure which shows the specific example of the regulation member used in the fixing device which concerns on this embodiment.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the drawings, the same or corresponding parts are designated by the same reference numerals and the description is not repeated. Further, in the present embodiment, the X-axis and the Y-axis of the three-dimensional Cartesian coordinate system are parallel in the horizontal direction, and the Z-axis is parallel in the vertical direction. The direction along the Y-axis is an example of the direction along the "rotational axis" of the "pressurizing member" of the present invention.

The configuration and operation of the image forming apparatus 2 including the fixing apparatus 12 will be described with reference to FIG. FIG. 1 is a diagram showing an image forming apparatus 2. The image forming apparatus 2 is, for example, a copying machine, a printer, a fax machine, or a multifunction device having these functions.

As shown in FIG. 1, the image forming apparatus 2 includes a reading unit 4, a feeding unit 6, a conveying unit 8, an image forming unit 10, a fixing device 12, and a discharging unit 14.

The reading unit 4 reads the image of the document G. The reading unit 4 generates image data from the read image. The feeding unit 6 accommodates a plurality of sheets S and feeds the sheets S to the conveying unit 8. The sheet S is, for example, a sheet made of paper or synthetic resin. The transport unit 8 includes a plurality of transport roller pairs, and transports the sheet S to the image forming unit 10.

In the present embodiment, the image forming unit 10 forms a toner image on the sheet S by an electrophotographic method. Specifically, the image forming unit 10 includes a photoconductor drum, a charging device, an exposure device, a developing device, a replenishing device, a transfer device, a cleaning device, and a static elimination device.

The fixing device 12 heats and pressurizes the toner image to fix the toner image on the sheet S. The transport unit 8 transports the sheet S on which the toner image is fixed to the discharge unit 14. The discharge unit 14 discharges the sheet S to the outside of the image forming apparatus 2.

(Outline of the present invention)
Next, the fixing device 12 will be described with reference to FIG. FIG. 2 is a perspective view of the fixing device 12 according to the present embodiment as viewed from diagonally above.

As shown in FIG. 2, the fixing device 12 includes a fixing belt 70, a heating unit 30, a regulating member 24, and a second holding member 60. The fixing belt 70 is arranged on the side of the fixing device 12 shown in FIG. 1 closer to the side wall of the image forming device 2.

The fixing belt 70 fixes the toner image on the sheet S. The fixing belt 70 is endless, has a substantially cylindrical shape, and has flexibility. The fixing belt 70 rotates in accordance with the rotation of a pressure roller (not shown) arranged so as to face the fixing belt 70. The fixing belt 70 has a plurality of layers. The fixing belt 70 forms, for example, a polyimide layer, and a release layer is further formed on the polyimide layer. The release layer is, for example, a heat-resistant film made of fluororesin.

The heating unit 30 includes a first holding member 20, a heater 22, and an electrode 72. The heating unit 30 heats the fixing belt 70 by the heater 22. The heating unit 30 faces the inner peripheral surface of the fixing belt 70. The heating unit 30 extends along the virtual rotation axis of the fixing belt 70.

The first holding member 20 has a heater mounting portion 40 described later in FIG. 4 on a surface of the first holding member 20 facing the inner peripheral surface of the fixing belt 70, and the heater 22 is mounted by the heater mounting portion 40. To do.

The electrode 72 is connected to a power source (not shown). The heater 22 generates heat by electric power supplied from a power source (not shown) through the electrode 72, and heats the fixing belt 70.

The regulating member 24 surrounds and mounts the first holding member 20 to which the heater 22 is mounted so that the heater 22 does not come off from the first holding member 20, and the heater 22 moves with respect to the first holding member 20. Regulate that. The regulating member 24 includes a cavity 26. The regulating member 24 is fitted with the heating portion 30 by the heating portion 30 to which the heater 22 is attached penetrates through the cavity portion 26.

According to the present embodiment, the regulating member 24 can prevent the heater 22 from coming off from the first holding member 20.

One end of the fixing belt 70 in the rotation axis direction is slidably mounted on the second holding member 60. The second holding member 60 includes the legs 62. The leg portion 62 holds the heating portion 30 and the regulating member 24 so as to be held.

(Concrete example)
Next, a specific example of the fixing device 12 according to the present embodiment will be described with reference to FIGS. 3A to 8A. 3A and 3B are external perspective views of the regulating member 24.

As shown in FIGS. 3A and 3B, the regulating member 24 has a cavity 26. The cavity 26 includes a first surface 29, a second surface 27, a third surface 23, and a fourth surface 23. The first surface 29 faces the heater 22 mounted on the first holding member 20. The first surface 29 is preferably a flat surface. The second surface 27 faces the first surface 29. The third surface 23 and the fourth surface 23 are continuous with the first surface 29 and the second surface 27, respectively. The first surface 29, the second surface 27, the third surface 23, and the fourth surface 23 form a cavity 26 that surrounds the first holding member 20 to which the heater 22 is mounted.

The heater 22 and the first holding member 20 are mounted on the regulating member 24 by penetrating the first holding member 20 to which the heater 22 (FIG. 2) is mounted in the cavity 26.

The heater 22 may be attached to the heater attachment portion 40 using an adhesive. The adhesive takes time to dry. Therefore, after aligning the heater 22 with the heater mounting portion 40, the user manually presses the heater 22 and the first holding member 20 so that the heater 22 does not come off from the first holding member 20.

According to this embodiment, it is not necessary to bond the heater 22 to the first holding member 20. The user can easily attach the heater 22 to the first holding member 20 by fitting the first holding member 20 and the heater 22 into the cavity 26 of the regulation member 24 in a state where the heater 22 is attached to the first holding member 20. It is possible to suppress deviation from 20.

Next, a specific example of the fixing device 12 will be described with reference to FIGS. 4 (a) to 8 (8). 4 (a) to 8 are views showing a procedure for fitting the regulating member 24 into the fixing device 12.

FIG. 4A is a perspective view of the heater 22 and the first holding member 20 before the heater 22 is attached to the first holding member 20 as viewed from diagonally downward. FIG. 4B is a perspective view of the heater 22 and the first holding member 20 after the heater 22 is attached to the first holding member 20 in FIG. 4A as viewed from diagonally downward. FIG. 5 is a diagram showing a mode in which the regulating member 24 is fitted into the first holding member 20. FIG. 6 is a diagram showing a mode in which the fitting of the regulation member 24 is completed. FIG. 7 is a diagram showing a mode in which the second holding member 60 and the fixing belt 70 are attached to the fixing device 12. FIG. 8 is a diagram showing a mode in which the cap 90 is attached to the fixing device 12.

First, as shown in FIG. 4A, the first holding member 20 includes a heater mounting portion 40. The heater mounting portion 40 is formed on the surface of the first holding member 20 on the side in contact with the fixing belt 70. The heater mounting portion 40 includes at least an end portion 42, an end portion 46, and an end portion 48. The end portion 46 and the end portion 48 are formed on the N side in the lateral direction of the heater mounting portion 40. The end portion 42 is formed at one end of the heater mounting portion 40 on the P side in the longitudinal direction. The end portion 42 may be formed at the other end of the heater mounting portion 40 on the P side in the longitudinal direction.

As shown in FIG. 4B, the user fits the heater 22 into the heater mounting portion 40 in line with the end 42, the end 46, and the end 48 of the heater mounting portion 40.

In this case, a heat-sensitive body such as a thermistor (not shown) may be attached to the side of the first holding member 20 opposite to the heater attachment portion 40. The heat sensitive body may be pressed toward the heater 22 in order to accurately measure the temperature of the heater 22. Therefore, the heater 22 was easily detached from the heater mounting portion 40.

Therefore, as shown in FIG. 5, the user fits the regulating member 24 into the first holding member 20 from the end portion on the longitudinal direction P side of the first holding member 20 along the direction A. That is, the user inserts the first holding member 20 into the cavity 26 of the regulating member 24.

The user moves the regulation member 24 to a position where the first surface 29 of the regulation member 24 faces the heater 22. The heater 22 is restricted from moving in the longitudinal direction P and the lateral direction N by the end 42, the end 46, and the end 48 of the heater mounting portion 40. Further, the heater 22 is restricted from moving in the direction perpendicular to the longitudinal direction P and the lateral direction N by the regulating member 24. Therefore, the heater 22 is less likely to come off from the first holding member 20, and the heater 22 is prevented from falling off from the first holding member 20.

Next, as shown in FIGS. 3A and 3B, the second surface 27 of the regulating member 24 is the heater 22 when the first holding member 20 to which the heater 22 is mounted is passed through the cavity 26. Includes a pressing portion 25 that presses the first holding member 20 so as to bring the first holding member 20 into close contact with the first surface 29.

The pressing portion 25 is a member such as a convex portion that is arranged on the second surface 27 of the regulating member 24 and projects from the second surface 27 toward the first surface 29 side. The pressing portion 25 extends in the direction in which the first holding member 20 advances when the first holding member 20 is passed through the hollow portion 26 of the regulating member 24 on the second surface 27 of the regulating member 24.

As shown in FIG. 3A, the pressing portion 25 has a small length on the side where the first holding member 20 is inserted, and as shown in FIG. 3B, the first holding member 20 has a hollow portion 26. It may be formed so that the length increases as the process proceeds.

As shown in FIG. 5, the user inserts the regulating member 24 into the first holding member 20 along the direction A. As the first holding member 20 is inserted into the cavity 26 of the regulating member 24, the pressing portion 25 (FIG. 3) presses the first holding member 20 toward the first surface 29 side of the regulating member 24. As a result, the heater 22 is strongly adhered to the first holding member 20.

According to the present embodiment, the opening area of the cavity 26 on the side where the first holding member 20 is inserted is large, so that the user can easily insert the first holding member 20 into the regulating member 24. Further, as the first holding member 20 advances through the cavity 26, the first holding member 20 is strongly adhered to the first surface 29 of the regulation member 24. As a result, the heater 22 is strongly adhered to the first holding member 20.

Next, a specific example of the fixing device 12 according to the present embodiment will be described with reference to FIGS. 3 (a) and 3 (b) and FIG.

As shown in FIGS. 3A and 3B, the regulating member 24 includes an engaging portion 28. The engaging portion 28 extends along the direction in which the first holding member 20 fits the hollow portion 26 of the engaging portion 28. The first holding member 20 includes an engaged portion 32 that engages with the engaging portion 28.

The engaging portion 28 is provided on the third surface 23 or the fourth surface 23 of the regulating member 24. Further, the first holding member 20 has a shape in which the engaging portion 28 engages on the path through which the engaging portion 28 of the regulating member 24 advances when the regulating member 24 is fitted into the first holding member 20. The formed engaged portion 32 is provided.

When the engaging portion 28 is a concave portion as shown in FIG. 6, the engaged portion 32 provided on the first holding member 20 is preferably a convex portion. Further, when the engaging portion 28 is a convex portion, it is preferable that the engaged portion 32 provided on the first holding member 20 is a concave portion.

Further, as shown in FIG. 6, the engaging portion 28 can form a wide opening on the side where the first holding member 20 is inserted. Further, the opening of the engaging portion 28 may be gradually narrowed along the direction in which the first holding member 20 advances through the cavity portion 26.

Further, as shown in detail in FIGS. 3A and 3B, the engaging portion 28 may be provided on either the 3rd surface 23 or the 4th surface 23, and the 3rd surface 23 or the 4th surface may be provided. It may be provided only in any one of 23.

According to the present embodiment, since the regulating member 24 is stably fitted to the first holding member 20, the heater 22 is stably mounted to the first holding member 20.

Further, as shown in FIG. 6, the fixing device 12 includes a metal stay 80. The metal stay 80 reinforces the first holding member 20. The metal stay 80 is arranged so as to face the first holding member 20, and extends along the longitudinal direction P of the first holding member 20.

The metal stay 80 includes a pair of projecting portions 82 at the end portion of the first holding member 20 on the P side in the longitudinal direction. The regulating member 24 fits into and engages with the space formed between the protruding portion 82 of the metal stay 80 and the engaged member 32 of the first holding member 20.

Next, as shown in FIG. 7, the first holding member 20 includes an electrode 72. The heater 22 is connected to the electrode 72. When the first holding member 20 is inserted into the regulating member 24 and the engaging portion 28 of the regulating member 24 engages with the engaged portion 32 of the first holding member 20, the electrode 72 of the first holding member 20 is exposed. ..

On the other hand, when the fixing belt 70 rotates, the inner peripheral surface of the fixing belt 70 slides with respect to the heater 22, so that the surface of the heater 22 may be coated with oil. Although the heater 22 is connected to the electrode 72, it is preferable that the oil is separated from the electrode 72.

As shown in FIG. 7, the first surface 29 of the regulating member 24 is in close contact with the heater 22 to prevent the oil applied to the heater 22 from flowing out to the electrode 72.

According to the present embodiment, when the regulating member 24 is fitted into the first holding member 20, the first surface 29 of the regulating member 24 is flat, so that the oil is prevented from flowing out to the electrode 72 by the regulating member 24. ..

Further, as described with reference to FIG. 3, the pressing portion 25 provided on the second surface 27 of the regulating member 24 presses the first holding member 20 toward the first surface 29 of the regulating member 24, so that the oil Is more preferably prevented from flowing out to the electrode 72 by the regulating member 24.

Next, as shown in FIG. 7, when assembling the fixing device 12, the user attaches the second holding member 60 to the first holding member 20 so that the legs 62 of the second holding member 60 hold the regulating member 24. Install along direction A.

The second holding member 60 includes a brim portion 64. The brim portion 64 includes and supports the heating portion 30 and the metal stay 80. Further, the brim portion 64 slidably holds one end of the fixing belt 70 in the rotation axis direction on the outer peripheral surface of the brim portion 64. That is, the user attaches the fixing belt 70 to the outer peripheral surface of the brim portion 64 along the C direction.

Next, as shown in FIG. 8, the fixing device 12 includes a cap 90. The cap 90 covers the exposed electrode 72 (FIG. 7). The cap 90 includes a cord (not shown) for connecting the electrode 72 and a power supply (not shown).

The embodiments of the present invention have been described above with reference to the drawings. However, the present invention is not limited to the above-described embodiment, and can be implemented in various embodiments without departing from the gist thereof. In addition, various inventions can be formed by appropriately combining the plurality of components disclosed in each of the above embodiments. For example, some components may be removed from all the components shown in the embodiments. In addition, components across different embodiments may be combined as appropriate. In order to make the drawings easier to understand, each component is schematically shown, and the thickness, length, number, spacing, etc. of each component shown are actual for the convenience of drawing creation. Is different. Further, the material, shape, dimensions, etc. of each component shown in the above-described embodiment are merely examples, and are not particularly limited, and various changes can be made without substantially deviating from the configuration of the present invention. is there.

The present invention can be used in the fields of fixing devices and image forming devices.

2 Image forming device 4 Reading unit 6 Feeding unit 8 Conveying unit 10 Image forming unit 12 Fixing device 14 Discharging unit 20 First holding member 22 Heater 23 Fourth surface 24 Regulatoring member 25 Pressing unit 26 Cavity part 27 Second surface 28 Joint part 29 First surface 30 Heating part 32 Engagement part 70 Fixing belt 72 Electrode

Claims (6)

With the fixing belt
A heating portion that faces the inner peripheral surface of the fixing belt is provided.
The heating part
A heater that heats the fixing belt and
The first holding member to which the heater is mounted and
A fixing device including a regulating member that surrounds and mounts the first holding member to which the heater is mounted and that restricts the heater from moving with respect to the first holding member. The regulatory member has a cavity and
The cavity is
The first surface facing the heater mounted on the first holding member and
The second surface facing the first surface and
The fixing device according to claim 1, further comprising the first surface and a third surface and a fourth surface continuous with the second surface. The second surface is a pressing portion that presses the first holding member so that the heater is brought into close contact with the first surface when the first holding member to which the heater is mounted is passed through the cavity. The fixing device according to claim 2, which includes. The regulating member includes an engaging portion extending along a direction in which the first holding member fits the cavity portion of the engaging portion, and the first holding member is an engaged portion that engages with the engaging portion. including,
The fixing device according to claim 2 or 3. The first holding member includes an electrode and includes an electrode.
The heater is connected to the electrode and
The fixing device according to claim 2 or 3, wherein the first surface is brought into close contact with the heater to prevent the oil applied to the heater from flowing out to the electrodes. The fixing device according to any one of claims 1 to 5.
The sheet is provided with an image forming portion for forming a toner image.
The fixing device is an image forming device that fixes the toner image on the sheet.

Images