JP5877414B2 - Exhaust system and image forming apparatus - Google Patents

Description

  The present invention relates to an exhaust system that exhausts air inside a machine to the outside of the machine, and an image forming apparatus including the exhaust system.

  Conventionally, as an exhaust system as described above, for example, there is one described in Patent Document 1. In this exhaust system, a duct is provided above the fixing unit. The duct is adjacent to the fixing unit, and includes a main body portion that is a cover without a bottom disposed immediately above the fixing unit, and two hollow cylindrical portions extending from the main body portion. The two cylindrical portions respectively communicate with two exhaust ports provided in the housing, and the inside is an air flow path. The diameter of each cylinder part is uniform, and is the same size as the diameter of each exhaust port.

  One exhaust fan is provided at the rear end of each exhaust port, and a filter for removing dust is provided at the front end of each exhaust port so as to block the flow path. Each exhaust fan rotates so as to convey the air inside the cylinder part from the main body part side to the exhaust port side. As a result, the air heated by the fixing unit is collected by the main body portion of the duct, and is discharged from the exhaust port to the outside of the housing through each cylindrical portion.

JP 2008-251514 A

  In general, the exhaust system is required to have a low pressure loss and to improve particle collection performance.

  SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide an exhaust system capable of enhancing the particle collection performance with a low pressure loss, and an image forming apparatus including the exhaust system.

In order to achieve the above object, one aspect of the present invention is an exhaust system provided in a device, and the exhaust system that forms a flow path of the air when the air is discharged from the inside of the device to the outside A duct, a blower provided in the exhaust duct, sucking air in the exhaust duct from the axial direction, and blowing in the axial direction; and a blower in contact with the blower port of the blower; Filter means for collecting air contained in the air, and a circulation channel for guiding a part of the air that has passed through the filter means to the upstream side of the air blowing means, The exhaust duct discharges the remainder of the air that has passed through the filter means to the outside of the device. Further, the exhaust duct has a duct portion in which the air blowing means and the filter means are provided, and there is a space between any one of the inner wall surfaces of the duct portion and the air blowing means and the filter means. The duct portion is provided with a first closing plate on the downstream side by a first predetermined distance from the filter means, and a second closing plate on the upstream side by a second predetermined distance from the air blowing means. The first closing plate overlaps with a partial area of the exhaust port of the filter means and the intake port of the duct portion in a plan view from the axial direction, and the second closing plate is a plan view from the axial direction. The duct overlaps with the exhaust port of the duct portion, and the circulation flow path includes the first closing plate, the inner wall surface, the air blowing means, and the filter means, and has passed through the filter means. Part of air Leads to the upstream side of the blowing means.
Another aspect of the present invention is an exhaust system provided in an apparatus, and when exhausting air from the inside of the apparatus to the outside, an exhaust duct that forms a flow path of the air, and the exhaust system It is provided in the duct, and is arranged so as to be in contact with the blower means for sucking air in the exhaust duct from the axial direction and blowing the air in the axial direction, and the blower port of the blower means, and passes the air from the blower means And a filter means for collecting particles contained in the air, and a circulation channel for guiding a part of the air that has passed through the filter means to the upstream side of the blower means, the exhaust duct, The remaining air that has passed through the filter means is discharged to the outside of the device. The exhaust duct has a duct part in which the air blowing means and the filter means are provided, and a space is formed between any inner wall surface of the duct part and the air blowing means and the filter means. The duct portion is provided with a closing plate at a predetermined distance downstream from the filter means, and the closing plate overlaps with the entire area of the outlet of the filter means in a plan view from the axial direction, The duct portion is formed with an exhaust port for exhausting air in a direction non-parallel to the axial direction, and the circulation flow path includes the closing plate, the inner wall surface, the air blowing means, and the filter means. And part of the air that has passed through the filter means is guided upstream of the air blowing means.

  This exhaust system is typically provided in an image forming apparatus.

  According to the above aspect, the circulation channel allows a part of the air that has once passed through the filter means to pass again through the filter means, so that it is possible to improve particle collection performance with low pressure loss. It becomes.

1 is a longitudinal sectional view showing an internal configuration of an image forming apparatus according to an embodiment of the present invention. It is a perspective view which expands and shows the exhaust system of FIG. It is a perspective view of the ion generator of FIG. 2, a ventilation means, and a filter means. It is a longitudinal cross-sectional view of the ion generator of FIG. 2, a ventilation means, and a filter means. 6 is a longitudinal sectional view showing an exhaust system according to Modification Example 1. FIG. It is a perspective view which shows the exhaust system which concerns on the modification 2. FIG.

(Embodiment)
Hereinafter, an exhaust system according to an embodiment of the present disclosure and an image forming apparatus including the exhaust system will be described with reference to the drawings. First, some drawings show arrows X, Y, and Z. An arrow X indicates the right direction of the image forming apparatus, an arrow Y indicates the backward direction (depth direction) of the image forming apparatus, and an arrow Z indicates the upward direction of the image forming apparatus. In addition, alphabetic small letters a, b, c, and d described after the reference numerals are subscripts representing yellow (Y), magenta (M), cyan (C), and black (Bk). For example, the photoconductor drum 22a means the photoconductor drum 22 for yellow.

(Schematic configuration of image forming apparatus)
In FIG. 1, an image forming apparatus is a typical example of a device provided with an exhaust system, and is an MFP (Multifunction Peripheral) adopting an electrophotographic system. The image forming apparatus forms a full-color image by, for example, a tandem method and prints it on a recording medium such as paper. For this purpose, the image forming apparatus generally includes process units 20a to 20d, a laser scanning optical system 42, an intermediate transfer belt 30, and a fixing unit 48 in the main body 10.

  The process units 20a to 20d are arranged side by side from the left to the right of the image forming apparatus, and have photosensitive drums 22a to 22d as typical examples of image carriers. The photosensitive drums 22a to 22d extend in the depth direction and rotate by a driving force from a motor (not shown). Further, around the photosensitive drums 22a to 22d, charging means 24a to 24d, developing means 26a to 26d, cleaning means 28a to 28d, and the like are arranged from upstream to downstream in the rotation direction.

  The laser scanning optical system 42 is provided below the process units 20a to 20d, and receives image data of Y, M, C, and K colors from, for example, a personal computer. The laser scanning optical system 42 emits light beams Ba to Bd modulated with the received image data toward the photosensitive drums 22a to 22d.

  The intermediate transfer belt 30 is rotationally driven endlessly in the counterclockwise direction indicated by an arrow α when viewed from the front of the image forming apparatus. Further, primary transfer rollers 36a to 36d are provided at positions facing the photosensitive drums 22a to 22d with the intermediate transfer belt 30 interposed therebetween. Further, the secondary transfer roller 38 is pressed against the roller 32 with the intermediate transfer belt 30 interposed therebetween. The secondary transfer roller 38 and the intermediate transfer belt 30 form a secondary transfer region 40.

  A supply device 44 is provided below the main body 10. The supply device 44 takes out the sheets stacked inside one by one and sends them out to a transport path (hereinafter referred to as a transport path β) indicated by a one-dot chain line arrow β.

  On the transport path β, a timing roller pair 46, a secondary transfer region 40, a fixing unit 48, a discharge / reverse roller 50, and a discharge tray 52 are provided from the upstream side to the downstream side.

(Schematic operation of the image forming apparatus)
Next, a schematic operation of the image forming apparatus will be described. In the image forming apparatus, the charging units 24a to 24d charge the peripheral surfaces of the rotating photosensitive drums 22a to 22d. The laser scanning optical system 42 irradiates (exposes) light beams Ba to Bd on the peripheral surfaces of the charged photosensitive drums 22a to 22d, thereby forming Y, M, C, and K color electrostatic latent images. . The developing means 26a to 26d supply (develop) toner to the photosensitive drums 22a to 22d carrying the electrostatic latent images, thereby forming Y, M, C, and K color toner images. The toner images on the photosensitive drums 22a to 22d are electrostatically and sequentially transferred to the same area of the intermediate transfer belt 30 by the voltage applied to the primary transfer rollers 36a to 36d (primary transfer). As a result, a full-color synthetic toner image is formed on the intermediate transfer belt 30. The synthesized toner image is conveyed toward the secondary transfer region 40 while being carried on the intermediate transfer belt 30.

  On the peripheral surfaces of the photosensitive drums 22a to 22d, toner (transfer residual toner) that could not be primarily transferred remains. The transfer residual toner is scraped off by the cleaning units 28a to 28d and collected in a waste toner box (not shown) (cleaning).

  In addition, the sheet fed from the supply device 44 is transported on the transport path β and abuts against the stopped timing roller pair 46 without rotating. Thereafter, the timing roller pair 46 starts rotating so as to synchronize with the transfer timing in the secondary transfer area 40, and sends the temporarily stopped paper to the secondary transfer area 40.

  In the secondary transfer area 40, the composite toner image on the intermediate transfer belt 30 is transferred to the sheet fed by the timing roller pair 46 (secondary transfer). The sheet after the secondary transfer is sent out downstream of the conveyance path β by the secondary transfer roller 38 and the intermediate transfer belt 30.

  The fixing unit 48 includes a heating roller and a pressure roller that extend in the front-rear direction. A sheet fed from the secondary transfer region 40 is introduced between these rollers. The heating roller heats the toner on the paper passing between it and the pressure roller, and at the same time, the pressure roller presses the paper (fixing process). Thereafter, both rollers send out the fixed sheet downstream of the transport path β. The fixed sheet is discharged to the discharge tray 52.

(Exhaust system)
Since various particles are generated inside the main body 10, an exhaust system 66 as shown in FIG. 1 is provided inside the main body 10 so as not to be diffused outside the apparatus. In the example of the present embodiment, an exhaust system 66 fixed to the main body 10 is provided above the fixing unit 48. As shown in FIGS. 2 to 4, the exhaust system 66 includes an exhaust duct portion 68, an ion generator 70, a blower 72, and a filter 74.

  The exhaust duct portion 68 is made of a resin material or a metal material having heat resistance with respect to the temperature of the fixing unit 48, and constitutes a flow path for the air when the air inside the image forming apparatus is discharged to the outside. Specifically, the exhaust duct portion 68 includes first and second vertical duct portions 68e and 68f, first and second horizontal duct portions 68g and 68h, a third horizontal duct portion 68i, and a hopper. A portion 68j, a closing plate 68k, and a fourth horizontal duct portion 68l are provided. In the present embodiment, the duct portions 68e to 68i, 68l will be described as being formed of rectangular ducts.

  The first vertical duct portion 68e extends from directly above the rear end of the heating roller 48e, and the second vertical duct portion 68f extends from directly above the front end of the heating roller 48e.

  The first horizontal duct portion 68g is connected to the downstream end of the first vertical duct portion 68e and extends in the right direction. The upstream end of the second horizontal duct portion 68h is connected to the downstream end of the second vertical duct portion 68f, extends rightward, bends in the middle, and extends rearward. Further, the downstream end of the first horizontal duct portion 68g is further connected to the second horizontal duct portion 68h.

  The upstream end of the third horizontal duct part 68i is connected to the downstream end of the second horizontal duct part 68h via a hopper part 68j and extends rearward. Here, as shown in the dotted frame in FIG. 2, the area of the upstream end opening (that is, the intake port) A3 of the third horizontal duct portion 68i is equal to the downstream end opening (that is, the exhaust port) of the second horizontal duct portion 68h. ) It is larger than the area of A4. Also, the upper side of the downstream end of the third horizontal duct portion 68i is closed by, for example, a closing plate 68k (see the hatched portion), and the lower side is an opening A5. The opening A5 is an opening (that is, an exhaust port) at the downstream end of the third horizontal duct portion 68i.

  The upstream end of the fourth horizontal duct portion 68l is connected to the opening A5 of the third horizontal duct portion 68i. Further, the downstream end of the fourth horizontal duct portion 68l is connected to an exhaust port (not shown) formed on the back surface of the main body 10.

  The ion generator 70 is a preferable configuration that further improves the collection performance of particles and the like by the filter means 74 described later. As shown in FIGS. 3 and 4, the ion generator 70 is provided in the third horizontal duct portion 68 i and on the downstream side by a distance Δ from the air inlet A <b> 3. Moreover, the ion generator 70 is attached to the upper inner wall surface of the 3rd horizontal duct part 68i in this embodiment. The ion generator 70 applies a high voltage to its own electrode to create a flow of ions (discharge) in the air, and charges particles and the like that have entered the air.

  The air blowing means 72 and the filter means 74 are each attached to the lower inner wall surface of the third horizontal duct portion 68i.

  The blower 72 sucks upstream air from the direction of the axis α through the suction port 72e and blows the air from the blowout port 72f in the direction of the axis α by a rotating blade rotating around the axis α.

  The filter means 74 has an air supply port 74e and an exhaust port 74f, and the air supply port 74e is arranged so as to contact the blowout port 72f. Further, as shown in FIG. 4, the filter means 74 is arranged such that the exhaust port 74f is upstream from the closing plate 68k by a predetermined distance d1. Air from the blowout port 72f flows into the inside from the air supply port 74e of the filter means 74. The filter means 74 collects and passes the particles contained in the inflowed air, and discharges them from the exhaust port 74f. Further, the filter means 74 is constituted by an electrostatic filter by charging the fiber of the filter at the time of manufacture, or by a voltage application type filter that is charged to a polarity opposite to the charged polarity of the particles by a power supply circuit (not shown). Is done.

  Here, as shown in FIG. 3, the height of the upper surface of the air blowing means 72 relative to the lower inner wall surface of the third horizontal duct portion 68i is h1, and the lower inner wall surface and upper inner wall surface of the third horizontal duct portion 68i. If the height between is h2, h1 is smaller than h2. Here, if the height of the upper surface of the filter means 74 relative to the lower inner wall surface is h3, h3 is smaller than h2. In the present embodiment, h1 and h3 are set to the same value. Further, if the height of the exhaust port A5 with respect to the lower inner wall surface is h4, h4 is made smaller than h3. Thereby, the exhaust port 74f overlaps the closing plate 68k in a plan view from the axis α.

  With the above configuration, first, a space is formed between the exhaust port 74f of the filter means 74 and the closing plate 68k, and further, the upper surfaces of the blower means 72 and the filter means 74 and the upper side of the third horizontal duct portion 68i. A space is formed between the wall surfaces. This space becomes the circulation channel 76.

(About air flow)
In the exhaust system 66 configured as described above, the air around the rear end of the heating roller 48e flows in from the opening A1 of the first vertical duct portion 68e and flows upward. The air that has passed through the first vertical duct portion 68e flows in the first horizontal duct portion 68g.

  Air around the front end of the heating roller 48e flows from the opening A2 of the second vertical duct portion 68f and flows upward. The air that has passed through the second vertical duct portion 68f flows in the second horizontal duct portion 68h, and merges with the air from the first vertical duct portion 68e, and then enters the third horizontal duct portion 68i via the hopper portion 68j. Inflow.

  As shown in FIG. 2, since the intake port A3 is larger than the exhaust port A4, the air flowing into the third horizontal duct portion 68i stays in the vicinity of the intake port A3. In addition, air that has passed through the circulation channel 76 also flows in the vicinity of the air inlet A3. That is, the vicinity of the air inlet A <b> 3 serves as a joining point between the air that has flowed into the third horizontal duct portion 68 i and the air that is guided by the circulation flow path 76. The ion generator 70 charges particles contained in the air staying in the vicinity of the intake port A3. Thereafter, the air passes through the filter means 74 charged with a polarity opposite to that of the particle band electrode through the air blowing means 72. Particles contained in the air are collected by the filter means 74.

  Since the exhaust port 74f overlaps with the closing plate 68k in a plan view from the axis α, a part of the air that has passed through the filter means 74 hits the closing plate 68k and flows upward, passes through the circulation passage 76, and is blown. It is sent to the upstream side of the means 72 (near the air inlet A3). On the other hand, the remainder of the air that has passed through the filter means 74 is discharged to the outside of the image forming apparatus from the exhaust port on the back side of the main body 10 through the fourth horizontal duct portion 68l.

(Operation and effect of exhaust system)
As described above, according to the exhaust system 66, a part of the air that has passed through the filter unit 74 is circulated immediately upstream of the air blowing unit 72 through the circulation channel 76. This circulated air passes through the filter means 74 a plurality of times. Therefore, it is possible to use the filter means 74 with a low pressure loss and improve the particle collection performance.

(Appendix 1)
In the above-described embodiment, the circulation channel 76 is described as being formed between the upper surfaces of the blower unit 72 and the filter unit 74 and the upper inner wall surface of the third horizontal duct part 68i. However, the present invention is not limited to this, and the air blowing means 72 and the filter means 74 may be formed between the side surface parallel to the axis α and the inner side surface of the third horizontal duct portion 68i. Note 1 applies similarly to the following first and second modifications.

(Appendix 2)
In the above embodiment, the exhaust system 66 collects particles generated by the fixing unit 48. However, it may be provided anywhere as long as it is a particle generation location in the image forming apparatus. The image forming apparatus is not limited to the image forming apparatus and may be provided in another device. Note 2 applies similarly to the following first and second modifications.

(Modification 1)
Next, an exhaust system according to Modification 1 will be described with reference to FIG. The exhaust system 80 in FIG. 5 is different from the exhaust system 66 in FIG. 2 in that an exhaust duct 82 is provided instead of the exhaust duct portion 68. The exhaust duct 82 is different from the exhaust duct portion 68 in that it has a third horizontal duct portion 82e and a second closing plate 82f instead of the third horizontal duct portion 68i and the hopper portion 68j. Therefore, in FIG. 5, the same reference numerals are assigned to the components corresponding to those in FIGS.

  As shown in FIG. 5, the lower side of the upstream end of the third horizontal duct portion 82e is closed by a second closing plate 82f, and the upper side thereof is an opening (that is, an intake port) A6. The second closing plate 82f is provided upstream of the suction port 72e of the blower 72 by a second predetermined distance d2. The downstream end of the second horizontal duct portion 68h is connected to the intake port A6. Further, the upper side of the downstream end of the third horizontal duct portion 82e is a closing plate provided downstream by a predetermined distance (hereinafter referred to as a first predetermined distance for convenience) d1 with respect to the exhaust port 74f, as in the above embodiment. Hereinafter, for convenience, it is closed by 68k (referred to as a first closing plate), and its lower side is an exhaust port A5. The exhaust port A5 is connected to the upstream end of the fourth horizontal duct portion 68l.

  Here, the first closing plate 68k overlaps the upper area of the exhaust port 74f of the filter means and the intake port A6 of the third horizontal duct portion 82e in a plan view from the direction of the axis α, and the second closing plate 82f overlaps with the area below the suction port 72e and the exhaust port A5 in the same plan view.

  As is apparent from the above, in the first modification, the intake port A6 overlaps the first closing plate 68k without overlapping the exhaust port A5 in a plan view from the direction of the axis α. As a result, the air that has flowed into the third horizontal duct portion 82e is likely to pass above the filter means 74, hits the first closing plate 68k, and easily flows into the circulation flow path 76. as a result. It becomes possible to reduce the proportion of air discharged through the exhaust port A5 without passing through the circulation channel 76, and to improve the particle collection performance.

(Modification 2)
Next, an exhaust system according to Modification 2 will be described with reference to FIG. The exhaust system 90 of FIG. 6 is different from the exhaust system 66 of FIG. 2 in that an exhaust duct 92 is provided instead of the exhaust duct portion 68. The exhaust duct 92 is different from the exhaust duct portion 68 in that it has a third horizontal duct portion 92e, a closing plate 92f, and a fourth horizontal duct portion 92g instead of the third horizontal duct portion 68i and the hopper portion 68j. To do. Therefore, in FIG. 6, the same reference numerals are assigned to the components corresponding to those in FIGS.

  As shown in FIG. 6, the entire rear end area of the third horizontal duct portion 92e is closed by the closing plate 92f. The closing plate 92f is provided downstream from the exhaust port 74f by a predetermined distance d1 as in the above embodiment. Further, in the third horizontal duct portion 92e, an opening A7 is formed as an exhaust port A7 on one surface that is not parallel to the axis α and substantially orthogonal to the closing plate 92f. The fourth horizontal duct portion 68l is connected to the exhaust port A7, and the air flowing in from the exhaust port A7 is discharged out of the image forming apparatus from the exhaust port on the back side of the main body 10 through the fourth horizontal duct portion 92g. Is done.

  As described above, in the second modification, since the entire rear end area of the third horizontal duct portion 92e is closed, most of the air that has passed through the filter means 74 strikes the closing plate 92f and flows into the circulation flow path 76. Thereby, the ratio of the air which passes through the circulation flow path 76 increases further, and it becomes possible to improve the collection performance of particle | grains.

  The exhaust system according to the present invention has a low pressure loss and can improve the particle collection performance, and can be applied to various devices. In addition, the image forming apparatus according to the present invention includes an exhaust system that has a low pressure loss and can improve the performance of collecting particles. In addition to the MFP, the image forming apparatus can be used as a color printer, a copier, or a copier. Useful.

66, 80, 90 Exhaust system 68, 82, 92 Exhaust duct 68e First vertical duct part 68f Second vertical duct part 68g First horizontal duct part 68h Second horizontal duct part 68i, 82e, 92e Third horizontal duct part 68j Hopper Portions 68l and 92g Fourth horizontal duct portions 68k and 92f Closing plate 70 Ion generator 72 Blowing means 74 Filter means 76 Circulating flow path 82f Second closing plate

Claims (5)

An exhaust system provided in the device,
When exhausting air from the inside of the device to the outside, an exhaust duct constituting the air flow path;
Blower means provided in the exhaust duct, sucking air in the exhaust duct from the axial direction, and blowing in the axial direction;
A filter means disposed so as to be in contact with the air outlet of the air blowing means, allowing air from the air blowing means to pass therethrough, and collecting particles contained in the air;
A circulation flow path for guiding a part of the air that has passed through the filter means to the upstream side of the air blowing means,
The exhaust duct discharges the remainder of the air that has passed through the filter means to the outside of the device ,
The exhaust duct has a duct part in which the air blowing means and the filter means are provided, and a space is formed between any inner wall surface of the duct part and the air blowing means and the filter means. ,
The duct portion is provided with a first closing plate on the downstream side by a first predetermined distance from the filter means, and a second closing plate on the upstream side by a second predetermined distance from the air blowing means, the first closing plate. Is overlapped with a partial area of the exhaust port of the filter means and the intake port of the duct part in a plan view from the axial direction,
The second closing plate overlaps with the exhaust port of the duct portion in a plan view from the axial direction;
The circulation flow path is constituted by the first closing plate, the inner wall surface, the air blowing means and the filter means, and a part of the air that has passed through the filter means is upstream of the air blowing means. Leading exhaust system.   2. The exhaust system according to claim 1, further comprising ion generation means for charging particles contained in the air at a junction of the air guided by the circulation channel and the air in the exhaust duct. The exhaust duct has a duct part in which the air blowing means and the filter means are provided, and a space is formed between any inner wall surface of the duct part and the air blowing means and the filter means. ,
The duct portion is provided with a closing plate at a predetermined distance downstream from the filter means, and the closing plate overlaps with a partial area of the exhaust port of the filter means in a plan view from the axial direction,
The circulation channel is constituted by the closing plate, the inner wall surface, the air blowing means and the filter means, and guides a part of the air that has passed through the filter means to the upstream side of the air blowing means. The exhaust system according to claim 1 or 2. An exhaust system provided in the device,
When exhausting air from the inside of the device to the outside, an exhaust duct constituting the air flow path;
Blower means provided in the exhaust duct, sucking air in the exhaust duct from the axial direction, and blowing in the axial direction;
A filter means disposed so as to be in contact with the air outlet of the air blowing means, allowing air from the air blowing means to pass therethrough, and collecting particles contained in the air;
A circulation flow path for guiding a part of the air that has passed through the filter means to the upstream side of the air blowing means,
The exhaust duct discharges the remainder of the air that has passed through the filter means to the outside of the device,
The exhaust duct has a duct part in which the air blowing means and the filter means are provided, and a space is formed between any inner wall surface of the duct part and the air blowing means and the filter means. ,
The duct portion is provided with a closing plate on the downstream side by a predetermined distance from the filter means, and the closing plate overlaps with the entire area of the outlet of the filter means in a plan view from the axial direction,
The duct portion is formed with an exhaust port for exhausting air in a direction non-parallel to the axial direction,
The circulation channel is constituted by the closing plate, the inner wall surface, the air blowing means and the filter means, and guides a part of the air that has passed through the filter means to the upstream side of the air blowing means . exhaust system. An image forming apparatus including an exhaust system according to any of claims 1-4.

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