JP6544301B2 - Image forming device - Google Patents

Description

  The present invention relates to an image forming apparatus, and more particularly to an image forming apparatus provided with a fixing unit.

  Conventionally, in an electrophotographic image forming apparatus such as a copying machine or a printer, a toner image is carried on the surface of an image carrier such as a photosensitive drum or an intermediate transfer belt, and the toner image is carried on the surface of the image carrier. Is transferred to the recording medium, the recording medium is sent to a fixing unit, and the toner image is fixed to the recording medium by the fixing unit, and then the recording medium is conveyed to a discharge tray or the like.

  A partition made of resin in order to suppress the heat of the fixing unit from escaping above and to the side of such a fixing unit, and to prevent the heat of the fixing unit from adversely affecting other devices and members. A member was provided.

  An image forming apparatus provided with a duct through which cooling air passes in the vicinity of the fixing unit is disclosed, for example, in Patent Documents 1 and 2 in order to prevent the heat of the fixing unit from adversely affecting other devices and members. It is done.

JP, 2009-14895, A JP, 2011-221279, A

  However, to prevent the heat of the fixing unit from escaping to the upper side or the side of the fixing unit, and to prevent the heat of the fixing unit from adversely affecting other devices and members, a resin partition member is used. In the structure provided, it is difficult to improve the heat dissipation of the partition member, and there is a problem that the partition member becomes hot. In addition, it is necessary to use a resin having high heat resistance and flame retardancy for the partition member, which causes a problem that the cost is increased.

  Further, as in Patent Documents 1 and 2, in the structure in which a duct is provided in the vicinity of the fixing unit in order to suppress the adverse effect of heat of the fixing unit on other devices and members, a space for providing a duct is provided. Since it becomes necessary, there is a problem that the size of the image forming apparatus is increased.

  The present invention has been made to solve the problems as described above, and an object of the present invention is to suppress the partition member from becoming high temperature and to suppress the increase in cost, and the device body is large. It is an object of the present invention to provide an image forming apparatus capable of suppressing the image formation.

  In order to achieve the above object, an image forming apparatus according to a first aspect of the present invention has a heating rotating body and a pressure rotating body pressed against the heating rotating body, and a recording in which a toner image is carried on the surface A fixing unit including a fixing member for fixing a toner image to a recording medium by heating and pressing a medium, and a housing for containing the fixing member, and a sheet metal disposed above the fixing unit over the entire area in the longitudinal direction of the fixing unit. And a blower for blowing a cooling air in a longitudinal direction of the fixing unit along a surface of the dividing member opposite to the fixing unit.

  In the image forming apparatus according to the first aspect of the present invention, the sheet metal partition member is provided above the fixing unit over the entire area in the longitudinal direction of the fixing unit. Thereby, compared with the case where the resin-made partition member is used, since the heat dissipation of a partition member can be improved, it can suppress that a partition member becomes high temperature. Moreover, since it is not necessary to use resin with high heat resistance and a flame retardance for a partition member, it can suppress that cost becomes high.

  In addition, since it is not necessary to provide a duct in the vicinity of the fixing unit for suppressing the adverse effect of heat of the fixing unit on other devices and members, it is possible to suppress an increase in the size of the image forming apparatus main body. it can.

  Furthermore, since the rigidity of the partition member can be improved as compared with the case where the resin partition member is used, the strength of the partition member can be improved, and dimensional variation due to heat of the partition member can be suppressed. .

FIG. 1 is a cross-sectional view showing the structure of an image forming apparatus according to an embodiment of the present invention. FIG. 2 is a cross-sectional view showing a structure around a fixing unit of the image forming apparatus of an embodiment of the present invention. FIG. 3 is a perspective view showing the structure of a fixing unit of the image forming apparatus of the embodiment of the present invention. FIG. 3 is a perspective view showing a structure around a fixing unit and a partition member of the image forming apparatus of an embodiment of the present invention. FIG. 2 is a perspective view showing the structure of a partition member of the image forming apparatus of the embodiment of the present invention. FIG. 2 is a perspective view showing a structure around a temperature detection sensor of the image forming apparatus according to an embodiment of the present invention. FIG. 2 is a perspective view showing the structure around the partition member of the image forming apparatus of an embodiment of the present invention from below. FIG. 2 is a perspective view showing the structure around the temperature detection sensor of the image forming apparatus of an embodiment of the present invention from below. FIG. 2 is a perspective view showing the structure of a main body frame of the image forming apparatus of one embodiment of the present invention. FIG. 3 is a side view showing the structure around the blower of the image forming apparatus according to the embodiment of the present invention, and is a view showing the flow of air (cooling air). It is the side view which showed the structure of the air blower periphery of the image forming apparatus of one Embodiment of this invention, and is the figure which showed the state which attached the duct to the side surface frame.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  An image forming apparatus 100 according to an embodiment of the present invention will be described with reference to FIGS. As shown in FIG. 1, the image forming apparatus 100 (here, a monochrome printer) is provided with a sheet feeding cassette 2 for storing sheets (recording media) stacked under the apparatus main body (image forming apparatus main body) 1 There is. In FIG. 1, the right side is illustrated as the front side of the image forming apparatus 100. Above the sheet feeding cassette 2 is formed a sheet conveying path 4 extending substantially horizontally from the front to the rear of the apparatus main body 1 and further extending upward to the sheet discharge portion 3 formed on the upper surface of the apparatus main body 1 The pickup roller 5, the feed roller 6, the image forming unit 9, the fixing unit 10, and the discharge roller pair 11 are disposed in this order along the sheet conveyance path 4 from the upstream side. Further, in the image forming apparatus 100, a control unit 90 for controlling the operation of each roller, the image forming unit 9, the fixing unit 10, etc. is disposed.

  The image forming unit 9 forms a predetermined toner image on a sheet by an electrophotographic process, and the photosensitive drum 14 is an image carrier rotatably supported in a clockwise direction in FIG. A charging device 15 disposed around the body drum 14, a developing device 16, a cleaning device 17, a transfer roller 18 disposed so as to face the photosensitive drum 14 with the sheet conveyance path 4 interposed therebetween, an upper portion of the photosensitive drum 14 , And an electrostatic discharger.

  When image data is input from a host device such as a personal computer, first, the surface of the photosensitive drum 14 is uniformly charged by the charging device 15. Then, an electrostatic latent image is formed based on the image data input on the photosensitive drum 14 by the laser beam from the exposure device 19. Further, toner is attached to the electrostatic latent image by the developing device 16 and a toner image is formed on the surface of the photosensitive drum 14.

  The toner image formed on the surface of the photosensitive drum 14 is transferred by the transfer roller 18 onto the sheet supplied to the nip (transfer nip) between the photosensitive drum 14 and the transfer roller 18. The sheet on which the toner image has been transferred is separated from the photosensitive drum 14 and conveyed toward the fixing unit 10. The fixing unit 10 is disposed downstream of the image forming unit 9 in the sheet conveying direction, and the sheet on which the toner image is transferred in the image forming unit 9 is heated by the fixing member 21 provided in the fixing unit 10. , And the toner image transferred onto the sheet is fixed. Then, the sheet on which an image is formed in the image forming unit 9 and the fixing unit 10 is discharged to the sheet discharge unit 3 by the discharge roller pair 11.

  Next, the fixing unit 10 and the structure around it will be described. As shown in FIG. 2, the fixing unit 10 uses, for example, an electromagnetic induction heating method, and a pressure roller (pressure rotation) that is in pressure contact with the belt member (heating rotating body) 21a as a heating member and the belt member 21a. A fixing member 21 including a body 21b, and a housing 23 accommodating the fixing member 21.

  As shown in FIG. 3, the housing 23 is formed to extend in the sheet width direction (perpendicular to the sheet conveying direction, perpendicular to the sheet of FIG. 2), and the whole is formed of resin. . At a predetermined position on the upper surface of the housing 23, a first through hole 23a is formed.

  In addition, a sheet metal frame 24 having an opening 24a formed thereon is attached to the upper surface of the housing 23 so as to avoid the first through hole 23a. The sheet metal frame 24 is formed by bending so as to cover the upper surface of the housing 23 and the upper portion of the front side surface. Further, a plurality of convex portions 24 b extending in the longitudinal direction of the fixing unit 10 are formed by drawing in a predetermined area of the sheet metal frame 24 (here, a portion covering the upper surface of the housing 23).

  As shown in FIGS. 2 and 4, a sheet metal partition member 30 is disposed above the fixing unit 10 over the entire area in the longitudinal direction of the fixing unit 10. The partition member 30 is formed to be bent so as to have an upper surface portion 31 covering the upper surface of the fixing unit 10 and a side surface portion 32 covering the upper portion of the front side surface of the fixing unit 10.

  As shown in FIG. 5, mounting portions 30 a for screwing and fixing to a pair of side frames 51 a and 51 b of the main body frame 50 described later are provided at both ends in the longitudinal direction of the partition member 30. In the partition member 30, a plurality of convex portions 30b extending in the longitudinal direction are formed by drawing.

  In the upper surface portion 31 of the partition member 30, a mounting recess 31a for mounting a temperature detection sensor 40 (see FIG. 4) made of a thermopile is formed. A second through hole 31 b is formed in the mounting recess 31 a at a position corresponding to the first through hole 23 a of the housing 23.

  As shown in FIG. 6, the temperature detection sensor 40 is fixed to the mounting recess 31 a of the partition member 30 via the mounting member 41 made of resin. A third through hole 41 a (see FIG. 8) is formed in the attachment member 41 at a position corresponding to the second through hole 31 b of the partition member 30. As shown in FIGS. 7 and 8, the detection unit 40a of the temperature detection sensor 40 includes the third through hole 41a, the second through hole 31b, and the first through hole 23a (see FIG. 3) in the belt member 21a. The surface temperature is detected, and the detection result is transmitted to the control unit 90. The control unit 90 controls the fixing temperature based on the detection result.

  Further, as shown in FIG. 6, the cooling air directed to the temperature detection sensor 40 is provided on the upstream side and the downstream side of the blowing direction of the blower 60 described later with respect to the temperature detection sensor 40 in the mounting member 41. A windproof wall 41b is formed to block the road.

  As shown in FIG. 9, the apparatus main body 1 has a main body frame 50 for supporting the fixing unit 10 and the partition member 30. The main body frame 50 includes a pair of side frames 51a and 51b disposed on both sides in the longitudinal direction of the fixing unit 10 and the partition member 30, an upper frame 52 bridged to the top of the side frames 51a and 51b, and side frames 51a and 51b. And a lower frame 53 bridged to the bottom of the frame.

  Attached to the side surface frame 51a is a blower 60 for feeding air outside the device body 1 into the device body 1. As shown in FIG. 10, the air (cooling air) sent into the inside of the device body 1 by the blower 60 passes through a duct (not shown) provided inside the device body 1, and the first opening of the side frame 51a. After being temporarily discharged to the outside of the apparatus main body 1 through the portion 51c, it passes through the duct 54 (see FIG. 11) provided on the outer surface of the side surface frame 51a and passes through the second opening 51d of the side surface frame 51a. 1 It is sent inside. The air (cooling air) sent into the inside of the apparatus body 1 is along the surface of the partition member 30 opposite to the fixing unit 10 (the upper surface of the upper surface 31 and the front surface of the side surface 32) in the longitudinal direction of the fixing unit 10. To cool the partition member 30.

  In the present embodiment, as described above, the sheet metal partition member 30 is provided above the fixing unit 10 over the entire area in the longitudinal direction of the fixing unit 10. Thereby, compared with the case where the resin-made partition member is used, since the heat dissipation of the partition member 30 can be improved, it can suppress that the partition member 30 becomes high temperature. Moreover, since it is not necessary to use resin with high heat resistance and a flame retardance for the partition member 30, it can suppress that a cost becomes high.

  In addition, since it is not necessary to provide a duct in the vicinity of the fixing unit 10 for suppressing the adverse effect of the heat of the fixing unit 10 on other devices and members, it is possible to suppress an increase in the size of the apparatus body 1. Can.

  Furthermore, since the rigidity of the partition member 30 can be improved as compared with the case of using the resin partition member, the strength of the partition member 30 can be improved, and the dimensional variation due to the heat of the partition member 30 can be suppressed. be able to.

  Further, as described above, the partition member 30 is fixed to the pair of side frames 51 a and 51 b in a bridging manner. Thus, the partition member 30 can be easily disposed above the fixing unit 10 over the entire area in the longitudinal direction of the fixing unit 10. In addition, the rigidity of the device body 1 can be improved.

  Further, as described above, the partition member 30 is formed with the convex portion 30 b extending in the longitudinal direction. Thereby, since the surface area of the partition member 30 can be enlarged, the heat dissipation of the partition member 30 can be further improved. Moreover, the rigidity of the partition member 30 can be further improved, and the rigidity of the apparatus main body 1 can be further improved.

  Further, as described above, since the temperature detection sensor 40 is attached to the sheet metal partition member 30 with relatively small dimensional variation, displacement of the position of the temperature detection sensor 40 can be suppressed, and the surface of the belt member 21a It is possible to suppress variations in temperature detection results.

  Further, as described above, the windproof wall 41 b is provided at least on the upstream side of the temperature detection sensor 40 in the air blowing direction of the blower 60 to block the air path of the cooling air directed to the temperature detection sensor 40. As a result, direct contact of the cooling air with the temperature detection sensor 40 can be suppressed, and thus variation of the temperature detection result by the temperature detection sensor 40 can be further suppressed.

  It should be understood that the embodiments disclosed herein are illustrative and non-restrictive in every respect. The scope of the present invention is indicated not by the description of the embodiments described above but by the claims, and further includes all modifications within the meaning and scope equivalent to the claims.

  For example, although the example which applied this invention to the monochrome printer was shown, this invention is not limited to this. Needless to say, it may be another image forming apparatus such as a color printer, a monochrome copying machine, a color copying machine, a digital multi-function machine, and a facsimile.

  Moreover, although the example using the belt member 21a as a heating rotary body was shown in the said embodiment, you may use a heating roller as a heating rotary body.

  Moreover, in the said embodiment, although the example which provided the convex-shaped part 30b extended to a longitudinal direction in the partition member 30 was shown, this invention is not limited to this. The partition member 30 may be provided with a concave portion extending in the longitudinal direction. Further, the partition member 30 may be provided with a convex portion or a concave portion extending in the short direction.

  Although the temperature detection sensor 40 is attached to the partition member 30 in the above embodiment, the present invention is not limited to this, and the temperature detection sensor 40 may be directly attached to the fixing unit 10.

10 Fixing Unit 21 Fixing Member 21a Belt Member (Heating Rotator)
21b Pressure roller (pressure roller)
Reference Signs List 23 housing 23a first through hole 30 partition member 30b convex portion 31b second through hole 40 temperature detection sensor 41b windproof wall 50 main body frame 51a, 51b side frame (main body frame)
52 Upper frame (body frame)
53 Lower frame (body frame)
60 blower 100 image forming apparatus

Claims (4)

A fixing member that includes a heating rotator and a pressing rotator that is in pressure contact with the heating rotator, and that heats and presses a recording medium having a toner image carried on its surface to fix the toner image on the recording medium; A fixing unit including the housing for containing the fixing member;
A sheet metal partition member disposed above the fixing unit over the entire area in the longitudinal direction of the fixing unit;
A blower for blowing a cooling air in a longitudinal direction of the fixing unit along a surface of the partition member opposite to the fixing unit;
A pair of main body frames disposed on both sides in the longitudinal direction of the fixing unit and the partition member;
Equipped with
The partition member is fixed in a bridge shape to the pair of body frames,
The housing and the partition member each have a first through hole and a second through hole,
A resin mounting member is mounted on the opposite surface of the partition member;
In the partition member, a temperature detection sensor for detecting the surface temperature of the heating rotary member through the first through hole and the second through hole is the opposite surface of the partition member through the attachment member. An image forming apparatus attached to the image forming apparatus. Wherein the partition member, the image forming apparatus according to claim 1, characterized in that convex portions or concave portions extending in the longitudinal direction of the partition member is formed. An attachment recess is formed in the partition member,
The mounting member is fixed to the mounting recess,
A windproof wall is provided at least on the upstream side of the temperature detection sensor in the air blowing direction with respect to the temperature detection sensor among the attachment members, for blocking a wind path of the cooling air directed to the temperature detection sensor. The image forming apparatus according to claim 1 . The image forming apparatus according to any one of claims 1 to 3, wherein the temperature detection sensor is made of a thermopile.

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