JP5874332B2 - Image forming apparatus - Google Patents

Description

  The present invention relates to an image forming apparatus, and more particularly to an exhaust heat structure in the apparatus.

  In an image forming apparatus using an electrophotographic method in a copying machine, a facsimile machine, a printer, a printing machine, etc., a non-fixed image made of unfixed toner transferred and carried on a recording medium such as paper is fixed and copied. Get things and print output.

  On the other hand, the configuration of the image forming unit will be described in the case of performing image formation of a plurality of colors. A photoconductor as a latent image carrier and a charging device, a developing device for performing image forming processing on the photoconductor It is known to use a process cartridge that houses a cleaning device.

  The process cartridge is provided so as to be detachable from a casing used as a main body of the image forming apparatus, and is taken out from the casing at the time of replacement of parts or developer or maintenance and inspection.

Inside the image forming apparatus, it is used for driving the photosensitive member and developing device of the process cartridge described above, for driving a transfer device used for transferring an image formed by each image forming unit, and for transferring to a recording sheet or the like. A driving motor is used for driving a fixing device that fixes a printed image and for driving a recording paper transport device.
These drive motors are members that serve as heat sources. For this reason, if the heat generated by the drive motor is left as it is, there is a possibility that the developer contained in the developing device in the process cartridge is deteriorated or overheated in the periphery of the process cartridge.

Therefore, a configuration is well known in which a heat exhaust duct that communicates with the outside of the device from the vicinity of the heat source such as a drive motor or a fixing device is provided, and heat from the heat source is discharged to the outside of the device using forced air blowing means such as a fan. .
However, with this configuration, ducts are arranged inside and outside the casing, and as a result, the apparatus becomes large due to an increase in the space volume inside the casing.

  For such a configuration, by utilizing the fact that a part of the drive motor is provided on one surface of the casing constituting the apparatus main body, a plate-like member to which a part of the drive motor is attached is attached to the casing. A configuration has been proposed in which an exhaust fan is disposed on the outer surface, an exhaust fan is disposed on the plate-like member, and an exhaust heat exhaust port is provided at the bottom of the housing when the drive motor side is the exhaust heat intake side (for example, Patent Literature 1).

By the way, among the above-mentioned electrical boards, electrical boards such as a control board for driving control of the drive source are also included. When the drive motor is a target, the electrical board is disposed in the vicinity of the drive motor. Convenience during maintenance is planned.
The electrical board may include many heat generating elements, and becomes a heat generating source different from the drive source described above.

  Therefore, as an exhaust heat structure for electrical boards, a lunch box-shaped inner bracket that houses an electrical board with a low maintenance frequency and has many exhaust heat ports on the top surface, and an opening surface of the bracket that has a high maintenance frequency and has a high maintenance frequency And an outer bracket to which an electrical board having an area smaller than the opening area is attached, and the inner bracket can be opened and closed with respect to the housing wall surface, and the outer bracket can be opened and closed with respect to the inner bracket Each of the inner brackets has a structure in which a fan is disposed below the heat sink and the heat sink opposite to each other that form a duct (for example, Patent Document 2).

In the configuration disclosed in Patent Document 2, it is possible to expose the electrical board simply by opening and closing the bracket during maintenance of the electrical board, and the heat generated from the electrical board is a duct and fan configured by a heat sink. By so doing, it is discharged into the space outside the bracket.
In addition, regarding the exhaust heat of the electrical board, a configuration in which a dedicated exhaust heat duct is provided instead of the bracket described above has been proposed (for example, Patent Document 3).

In the configuration of Patent Document 1 in which the exhaust heat structure for the drive motor is disclosed, when the drive motor needs to be maintained, the plate-like member on which the drive motor is supported must be removed. For this reason, there is a possibility that disassembly and assembly during maintenance work may be troublesome. In addition, the configuration disclosed in Patent Document 1 is configured to block noise generated from a drive motor or the like by disposing an inner cover between the plate-like member and the electrical board.
For this reason, when maintaining the drive motor, it is necessary to remove and assemble the inner cover in addition to the plate-like member described above, so the maintenance workability is poor.

  On the other hand, in the configurations disclosed in Patent Documents 2 and 3, since the exhaust heat of the electrical board that is not related to the drive motor is targeted, the configuration related to the exhaust heat of the drive motor is not considered. Moreover, it is necessary to provide special members such as inner and outer brackets as components for exhaust heat of the electrical board, and the number of parts cannot be denied.

  An object of the present invention is to perform maintenance work of equipment arranged inside using existing components without increasing the number of parts or complicating in view of the problem in the heat exhaust mechanism in the conventional image forming apparatus. It is an object of the present invention to provide an image forming apparatus having a configuration capable of effectively exhausting heat without impairing performance.

In order to achieve this object, the present invention supports a drive motor used as a drive source of an image forming unit arranged in a casing constituting the apparatus main body by one surface of the casing, In the image forming apparatus having a structure in which the exterior surface of the apparatus main body is located outside the support surface,
Between the one surface of the housing that supports the drive motor and the exterior surface, an electrical unit having a surface that is supported by the housing so as to be opened and closed and forms the exterior surface is provided,
The electrical unit is provided with electrical components , and a position facing the drive motor and / or an electrical board in the drive unit on a side opposite to the exterior surface, a position facing the drive motor and / or the electrical board, and A duct having an opening at a position away from a position facing the drive motor and / or the electrical board, and an exhaust fan positioned near the opening at a position away from the drive motor and / or the electrical board are provided. In the image forming apparatus,

According to the present invention, the duct and the exhaust fan that can discharge the heat from the driving roller are provided by using one surface of the electrical unit that is often provided in advance, so that only the electrical unit used as an existing structural product is used. Heat can be discharged without adding a special heat exhaust structure.
Moreover, since the electrical unit is supported so as to be openable and closable with respect to the housing, when the drive motor is located behind the electrical unit, the electrical unit is opened when maintaining the drive motor. As a result, the duct is also retracted from the position facing the drive motor, so that it is not necessary to remove the duct.
This makes it possible to improve maintenance workability unlike the case where maintenance work such as removal or assembly of ducts other than maintenance is required.

1 is a schematic diagram for explaining a configuration of an image forming apparatus according to an embodiment. It is a figure for demonstrating the structure of the process cartridge used in the apparatus shown in FIG. FIG. 2 is an external view illustrating the image forming apparatus illustrated in FIG. 1 with an exterior panel removed to leave only an electrical unit. It is an external view which shows the open state of the electrical equipment unit shown in FIG. It is an external view which shows the housing | casing part which removed the electrical equipment unit shown in FIG. FIG. 2 is an external view showing a peripheral portion including a process cartridge used in the image forming apparatus shown in FIG. 1. It is an external view which shows one surface of the electrical equipment unit shown in FIG. It is a side view of the electrical equipment unit shown in FIG. It is a perspective view for demonstrating the structure of the exhaust heat duct provided in one surface of the electrical equipment unit shown in FIG. It is an external view which shows the electrical equipment unit shown in FIG. 4, and the exhaust heat duct shown in FIG. 1 is an external view of an image forming apparatus. It is an external view which shows a part of heat exhaust duct in the state which removed a part in the image forming apparatus shown in FIG.

Hereinafter, embodiments for carrying out the present invention will be described with reference to the drawings.
In FIG. 1, the image forming apparatus 100 corresponds to each color (yellow, magenta, cyan, black) facing the lower surface of an intermediate transfer belt 80 as an unfixed image carrier in the intermediate transfer unit 101 in the main body. Image forming units 6Y, 6M, 6C, and 6Bk are arranged in parallel.
These image forming units 6Y, 6M, 6C, and 6Bk have the same structure except that the colors of toner used in the image forming process are different.

  Each of the image forming units 6Y, 6M, 6C, and 6Bk includes a photosensitive drum 1Y, 1M, 1C, and 1Bk as a latent image carrier, a charging unit (not shown) disposed around the photosensitive drum 1, and a developing device 5Y. 5M, 5C, 5Bk, cleaning means (not shown), and the like.

On the photoreceptor drums 1Y, 1M, 1C, and 1Bk, as an image forming process, a charging process, an exposure process, a development process, a transfer process, and a cleaning process are sequentially performed, and a desired process is performed on the photoreceptor drums 1Y, 1M, 1C, and 1Bk. The toner image is formed.
In the charging step, the photosensitive drum 1 is rotationally driven in a clockwise direction in the drawing by a driving unit (not shown), and the surface is uniformly charged at the position of the charging unit.
In the exposure process, when the surface of the photosensitive drum 1 reaches the irradiation position of the laser beam emitted from the exposure writing unit LB, an electrostatic latent image is formed on the surface by exposure scanning at this position. .
In the development process, the surfaces of the photoconductive drums 1Y, 1M, 1C, and 1Bk reach a position facing the developing devices 5Y, 5M, 5C, and 5Bk, and the electrostatic latent image is developed at this position to obtain a desired toner image. Is formed.

  The transfer process includes a primary transfer process in which images are sequentially superimposed and transferred onto the intermediate transfer belt 80 provided in the transfer device 1001, and a secondary in which the superimposed images are collectively transferred onto a transfer sheet P as a recording medium. In the primary transfer process, the surfaces of the photosensitive drums 1Y, 1M, 1C, and 1Bk reach the positions facing the intermediate transfer belt 80 and the primary transfer bias rollers 90Y, 90M, 90C, and 90Bk. Then, the toner images on the photosensitive drums 1Y, 1M, 1C, and 1Bk are transferred onto the intermediate transfer belt 80 at this position.

In the secondary transfer process, as will be described later, the superimposed image on the intermediate transfer belt 80 is collectively transferred onto the transfer paper P by a secondary transfer roller 190 as a secondary transfer unit.
In the cleaning process performed after the primary transfer, when the surfaces of the photosensitive drums 1Y, 1M, 1C, and 1Bk reach a position facing the cleaning device 10 shown in FIG. 2, the photosensitive drums 1Y, 1M, and The untransferred toner remaining on 1C and 1Bk is collected. After cleaning, the potential of the surfaces of the photosensitive drums 1Y, 1M, 1C, and 1Bk is initialized by a neutralizing roller (not shown). Through these steps, a series of image forming processes performed on the photosensitive drum 1 is completed.

  The image forming process described above is performed in each of the four image forming units 6Y, 6M, 6C, and 6Bk as shown in FIG. That is, laser light based on image information is irradiated from the exposure writing unit LB disposed below the image forming unit onto the photosensitive drums 1 of the image forming units 6Y, 6M, 6C, and 6Bk. . Thereafter, the toner images of the respective colors formed on the photosensitive drums 1Y, 1M, 1C, and 1Bk through the developing process are transferred onto the intermediate transfer belt 80 in an overlapping manner. In this way, a color image is formed on the intermediate transfer belt 80.

The four primary transfer bias rollers 90Y, 90M, 90C, and 90Bk respectively sandwich the intermediate transfer belt 80 with the photosensitive drums 1Y, 1M, 1C, and 1Bk to form a primary transfer nip. The primary transfer bias rollers 90Y, 90M, 90C, and 90Bk are applied with a transfer bias having a polarity opposite to the polarity of the toner.
The intermediate transfer belt 80 travels in the direction of the arrow and sequentially passes through the primary transfer nips of the primary transfer bias rollers 90Y, 90M, 90C, and 90Bk. In this way, the toner images of the respective colors on the photosensitive drums 1Y, 1M, 1C, and 1Bk are primarily transferred while being superimposed on the intermediate transfer belt 80.

  Thereafter, the intermediate transfer belt 80 onto which the toner images of the respective colors are transferred in a superimposed manner reaches a position facing the secondary transfer roller 190 as a secondary transfer unit. The color toner image carried on the intermediate transfer belt 80 is transferred onto a transfer paper P as a recording medium conveyed to the secondary transfer nip position. A series of transfer processes is completed through such a procedure.

A plurality of transfer sheets P are stacked and stored in a sheet feeding unit 260 disposed in the lower part of the main body of the image forming apparatus 100 (hereinafter also referred to as the apparatus main body 100 for convenience). Paper is separated and fed.
The fed transfer paper P is temporarily stopped by the registration roller pair 280, and after the oblique deviation is corrected, it is conveyed toward the secondary transfer nip by the registration roller pair 280 at a predetermined timing. Then, when the image carried on the intermediate transfer belt 80 is batch-transferred onto the transfer paper P at the secondary transfer nip, and the image on the intermediate transfer belt 80 is a superimposed image for each color, a desired color image is obtained. Is transcribed.

The transfer paper P onto which the color image has been transferred at the position of the secondary transfer nip is conveyed to the fixing unit 110 where the color image transferred to the surface is fixed by heat and pressure generated by the fixing roller and the pressure roller. The
After the fixing, the transfer paper P is discharged as an output image to the paper discharge unit 300 formed on the upper surface of the apparatus main body by the paper discharge roller pair 290 and stacked. Thus, a series of image forming processes in the image forming apparatus is completed. In FIG. 1, reference numeral 320 denotes a reading unit.

A process cartridge 102 having the configuration shown in FIG. 2 is used in the image forming units 6Y, 6M, 6C, and 6Bk that perform image formation for each color.
The process cartridge 102 is composed of a unit that can be attached to and detached from the apparatus main body 100, and a photosensitive drum (denoted by reference numeral 1 for convenience) used for image forming processing is disposed inside.
Around the photosensitive drum 1, there are a charging device 7, a writing device (for the sake of convenience, writing light is indicated by L), a developing device 5, and a cleaning device 10 for executing an image forming process along the direction of the arrow shown in the drawing. Has been placed.
The charging device 7 uses a charging roller that can rotate in the vicinity of the photosensitive drum 1, and the cleaning device 10 includes a cleaning blade 10 </ b> A that scrapes residual toner from the photosensitive drum 1 after transfer and the photosensitive drum 1. A lubricant applying device 10B for applying a lubricant for reducing the friction coefficient is provided. In FIG. 2, reference numeral 7A denotes a cleaning roller that performs cleaning of the charging roller.

  In FIG. 2, the developing device 5 is isolated by a developing sleeve 5 </ b> A disposed inside a developing tank 50 having a space capable of accommodating a developer, and a partition portion 50 </ b> A disposed above and below and provided in the developing tank 50. First and second developer conveying members 51 and 52 disposed in the space, and a layer thickness defining doctor blade 53 disposed to face the lower peripheral surface of the developing sleeve 5A are provided.

  Although not shown in detail, the developing sleeve 5A is configured by a sleeve that is rotatably provided on the outer periphery of a magnet roller provided with a plurality of magnetic poles along the circumferential direction. Each magnetic pole provided on the magnet roller generates magnetic lines of force according to the arrangement sequence of the N and S poles, and the carrier in the magnetic brush formed along the lines of magnetic force moves around the sleeve as the sleeve rotates. It rolls on the surface.

The characteristics of this embodiment will be described as follows for the image forming apparatus having the above-described configuration.
3 shows the image forming apparatus 100 in which the reading unit 320 and the exterior panel 100A are partially removed from the state where the reading unit 320 and the exterior panel 100A shown in FIG. It is a figure which shows the housing | casing 100B which comprises a main body.

  2, a space for arranging a plurality of process cartridges 102 shown in FIG. 2 is provided inside a housing 100B. On one side in the longitudinal direction of the process cartridge 102, an exterior panel 100A of the image forming apparatus 100 is provided. The electrical unit 2000 having a surface 2000H that is located on the same plane and forms a part of the exterior surface of the apparatus is provided. For this reason, the electrical unit 2000 is disposed between one surface of the housing 100B in the image forming apparatus 100 and the exterior panel 100A.

  The electrical unit 2000 is supported by the housing 100B so as to be openable and closable as shown in FIG. 4. When opened, the electrical unit 2000 supports a drive motor (shown by the symbol M for convenience) described in the drawings after FIG. The drive unit 2001 can be exposed to the outside.

  FIG. 5 is a view showing the housing with the electrical unit 2000 removed. In FIG. 5, the drive motor M is placed on one surface of the housing, specifically on the wall facing the electrical unit 2000. It is attached via the drive unit 2001 described above.

  As shown in FIG. 6, the drive unit 2001 includes a bracket that collectively supports one side in the longitudinal direction of the plurality of process cartridges 102, and a drive motor M and an electrical board (labeled as PCB for convenience) on the outer surface. ) Is provided.

On the other hand, the configuration of the electrical unit 2000 provided between the drive unit support surface of the housing 100B and the exterior surface of the image forming apparatus 100, that is, the position of the exterior panel 100A is shown in FIG.
In FIG. 7, the electrical unit 2000 is provided with a duct 2002 on the surface facing the drive motor M and the electrical board PCB supported by the drive unit 2001 as shown in FIG.

  The duct 2002 is a housing having a space that communicates with a position facing the drive motor M and the electrical board PCB and a position away from the drive motor M and the electrical board PCB, and above the electrical unit 2000 as shown in FIG. It is configured.

  FIG. 9 is a diagram schematically illustrating the internal structure of the duct 2002 and the installation position of the duct 2002. In FIG. 9, the surface of the duct 2002 that faces the outer surface of the electrical unit 2000 is opened, and the drive motor The position facing the M and the electrical board PCB is a hot air intake section 2002A having a spread that can cover all or most of these members, and the position away from the drive motor M and the electrical board PCB is a hot air capture section. An exhaust section 2002B is formed by narrowing a space continuous from 2002A. Therefore, the air taken in from the hot air intake port 2002A side is aggregated and flows in the duct 2002 on the exhaust port 2002B side.

Inside the duct 2002, flow paths R1, R2, and R3 are formed for each member that requires exhaust heat in the hot air intake portion 2002A. Each of the flow paths R1, R2, and R3 is formed by a plurality of partition members 2002C. It is delimited.
The duct 2002 is attached to the outer surface of the electrical unit 2000 facing the drive unit 2001 on the housing side, thereby constituting a part of the outer wall of the electrical unit 2000, and the positions of the hot air intake part 2002A and the exhaust part 2002B are opened. Is configured. Accordingly, the hot air intake portion 2002A corresponds to an intake port, and the exhaust portion 2002B corresponds to an exhaust port.
Since the duct 2002 is provided along the wall surface of the electrical unit 2000, the air outlet 2002B has a direction from the direction parallel to the wall surface to the lath hole 320A1 on the exterior panel 320A described later. An elbow member 2004 for switching is attached.

  These flow paths R1, R2, and R3 are merged with the partition member 2002C missing in the vicinity of the exhaust portion 2002B, and are located inside the flow paths R1, R2, and R3 at the merge position, that is, near the exhaust port 2002B. An exhaust fan 2003 capable of discharging the taken-in hot air to the outside is provided.

  The duct 2002 is attached by fastening and engaging a plurality of screw insertion flanges 2002D and locking claws 2002E provided on a wall portion of one open surface with corresponding portions on the electrical unit 2000 side. .

The duct 2002 constitutes a part of the outer surface of the electrical unit 2000 facing the drive unit 2001 on the housing side, and the surface facing the electrical unit 2000 side is open. The hot air on the outer surface generated when the component generates heat can be discharged to the outside together with the hot air from the drive unit 2002 side. Therefore, by setting one surface of the electrical unit 2000 as an installation part of the duct 2002, in addition to the discharge of hot air from the drive unit 2001 which is the original function, the electrical unit 2000 which is the installation part also has a function of heat dissipation. be able to.

  Since the duct 2002 is integrated on one surface of the electrical unit 2000, as shown in FIG. 10, when the electrical unit 2000 supported to be openable / closable with respect to the housing 100B is opened, the housing 100B side Is not left behind. Thereby, at the time of maintenance for the drive unit 2001 located on the housing 100B side or a member in the vicinity thereof, a necessary portion can be exposed to the outside simply by opening the electrical unit 2000.

The exhaust port 2002B provided in the duct 2002 is positioned above the electrical unit 2000. As shown in FIGS. 11 and 12, the position of the exhaust port 2002B is a reading unit 320 (see FIG. 1) in the housing 100B. It corresponds to the exterior panel 320A attached to the provided frame. FIG. 11 shows a state in which the exterior panel 320A is removed.
The exterior panel 320A is provided with a lath hole (a plurality of elongated holes) 320A1 for exhaust, and the outside communicates with the inside of the duct 2002.

  In the above configuration, the duct 2002 constituting the exhaust heat flow path is used as a configuration for discharging the heat of the drive motor M provided at a position deeper than the exterior surface in the casing. It is provided in the electrical unit 2000 used as an existing configuration in the image forming apparatus. As a result, a part of the electrical unit 2000 is used as a heat exhausting part of the drive motor M, so that it is not necessary to provide a heat exhaust structure dedicated to the drive motor in the housing in advance. Therefore, since one surface of the electrical unit 2000 constitutes the duct 2002 as the heat exhausting part, unlike the case where the heat exhausting duct is newly provided, the number of parts can be reduced and the space can be saved.

  In addition, the duct 2002 is provided on a surface of the electrical unit 2000 that faces the drive motor M and constitutes one surface of the electrical unit 2000. Therefore, during maintenance and inspection of the back of the casing including the drive motor M, etc. When the electrical unit 2000 is opened, the duct 2002 is also retracted in the opening direction of the electrical unit 2000 together, so that it does not interfere with maintenance and inspection.

  The duct 2002 is provided with flow paths R1, R2, and R3 that are separated from each other so as to correspond to the position of the heat generation source. Since the intake air can be effectively applied to each heat source, there is no possibility that the intake of hot air is unbalanced between the heat generation sources as in the case where the intake air is taken in at a time.

In addition, in the said form, although the structure provided so that opening and closing was possible was made into object as a support structure of the electrical equipment unit 2000, it can also be set as the support structure which can be attached or detached instead.
In addition, the exhaust fan 2003 is not limited to a flow rate setting format based on a constant rotational speed, but can also use a form in which the rotational speed is changed by detecting the temperature at the air gathering position or the temperature at the heating source side. is there.

DESCRIPTION OF SYMBOLS 100 Image forming apparatus 100B Case 2000 Electrical unit 2001 Drive unit 2002 Duct 2002A Hot air intake port 2002B Exhaust port 2002C Partition member 2003 Exhaust fan R1, R2, R3 Flow path
PCB circuit board
M drive motor
200B case

JP 2008-83305 A Japanese Patent Laid-Open No. 7-129061 JP 2005-84235 A

Claims (6)

A drive motor used as a drive source for an image forming unit arranged in a casing constituting the apparatus main body is supported by one surface of the casing, and an exterior surface of the apparatus main body is located outside the support surface of the drive motor. In an image forming apparatus having a structure,
Between the one surface of the housing that supports the drive motor and the exterior surface, an electrical unit having a surface that is supported by the housing so as to be opened and closed and forms the exterior surface is provided,
The electrical unit is provided with electrical components , and a position facing the drive motor and / or an electrical board in the drive unit on a side opposite to the exterior surface, a position facing the drive motor and / or the electrical board, and A duct having an opening at a position away from a position facing the drive motor and / or the electrical board, and an exhaust fan positioned near the opening at a position away from the drive motor and / or the electrical board are provided. An image forming apparatus. Opening of a position opposed to the drive motor and or the electrical component mounting board in the duct, claims, characterized in that it is formed in a size capable of covering all or most of the drive motor and or the electrical component mounting board The image forming apparatus according to 1.   The image forming apparatus according to claim 1, wherein an opening of the duct at a position away from the drive motor is positioned above the electrical unit.   4. The image forming apparatus according to claim 1, wherein a part of a surface of the electrical component unit facing a housing supporting the drive motor is used for the duct. 5.   5. The flow path partitioned according to the installation position of the drive motor and / or the electrical board is formed between the openings in the duct. The image forming apparatus according to one. The flow path of claim 5, wherein a guide portion for aggregating the flow of air toward the exhaust fan taken from the drive motor and or the electrical component mounting board and the opposing positions are provided Image forming apparatus.

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