JP2014137464A - Detachable unit, process cartridge, developing unit, and image forming apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a detachable unit capable of efficiently cooling a driving mechanism on one end and the other end of a device without increasing the size of the device.SOLUTION: An imaging unit 23 is detachably attached in a front-rear direction X to a body case 2 of an image forming apparatus 1, and includes at least driving mechanisms as a heat generating part to be cooled. The imaging unit 23 comprises a front cover 25 and a rear cover 45 that cover driving mechanisms at a unit front end part 100a and at a unit rear end part 100b of the imaging unit 23, respectively. The front cover 25 includes a development side introduction port 26 that introduces an air from the body case 2 and guides the air into the imaging unit 23, and the rear cover 45 includes a development rear side introduction port 46 that introduces the air guided into the imaging unit 23 and an exhaust port 47 that exhausts the air introduced from the development rear side introduction port 46 to a body frame side.

Description

  The present invention relates to an attachment / detachment unit, a process cartridge, and a development unit that can be attached to and detached from an apparatus main body of an image forming apparatus such as a copying machine, a facsimile machine, a printer, a plotter, or a multi-function machine having a plurality of functions.

  With recent demands for downsizing image forming apparatuses and speeding up of image processing, developing devices and the like arranged around the photosensitive member have been driven at high speed. From such a point, by increasing the stirring speed of the developer in the developing device (for example, the process cartridge or the developing unit) that can be attached to and detached from the apparatus main body of the image forming apparatus, There is a tendency for the temperature rise to become significant. In particular, the temperature rise in the process cartridge or the developing unit may cause abnormal images such as defective development and white streaks due to repeated melting and solidification of toner in the developer. In view of this point, there is a case where it is desired to cool the drive mechanism of the detachable unit including the process cartridge and the developing unit. Usually, the driving mechanism of the developing device is detachable from a main body side driving mechanism disposed (meaning to be provided) on the back side of the main body of the apparatus via joints such as various couplings. .

As a method for cooling the developing device, there is a technology for blowing air along the outer surface of the cover of the developing device, a technology for forming a storage box on one end side of the developing device, and introducing and discharging air into the storage box (for example, a patent Documents 1, 2, etc.) are known.
The technology described in Patent Document 1 includes a blower fan that cools the developing device with an airflow, and the direction of the airflow generated by the blower fan is set in parallel to the direction in which the supply pipe is inserted and removed.
In the technique described in Patent Document 2, an intake port and an exhaust are provided in a storage box that stores a stirring gear that rotates a stirring member that stirs the developer and a developing gear that rotates a developing member that supplies the developer to the image carrier. A mouth is formed and a blower fan is provided.

However, in the configuration of the prior art including the above-described Patent Documents 1 and 2, the driving mechanism on one end side of the developing device cannot be efficiently cooled without increasing the size of the device.
For example, the technique described in Patent Document 1 requires a large duct member that guides the airflow (wind) along the outer surface of the cover of the developing device toward the drive mechanism on one end side of the developing device. There is a problem of becoming. Further, the technique described in Patent Document 2 also has a problem that the size of the apparatus increases because it is necessary to provide a blower fan around the housing box constituting the developing device.

  Therefore, the present invention has been made in view of the above circumstances, and has realized a detachable unit that can efficiently cool the drive mechanism on one end side or the other end side of the device without increasing the size of the device. The main purpose is to provide.

In order to solve the above problems and achieve the above object, the present invention employs the following characteristic means / invention specific items (hereinafter referred to as “configuration”).
The present invention is an attachment / detachment unit that is attachable / detachable in a predetermined attachment / detachment direction with respect to the apparatus main body of the image forming apparatus and includes at least a drive mechanism as a heat generating portion to be cooled. A cover member that covers the drive mechanism of the detachable unit is provided on one end side and the other end side, and any one of the cover members introduces air from the apparatus main body and is in the detachable unit. At least one first introduction port that guides to the other, and the other cover member of the cover members includes a second introduction port that introduces air guided into the detachable unit; And a discharge port for discharging the air introduced from the introduction port to the apparatus main body side.

  According to the present invention, a novel detachable unit that solves the above problems can be realized and provided by the above configuration. That is, according to the present invention, with the above configuration, the drive mechanism on one end side or the other end side of the apparatus can be efficiently cooled without increasing the size of the apparatus.

1 is a schematic configuration diagram of an entire image forming apparatus showing a first embodiment of the present invention. FIG. 6 is a schematic cross-sectional view of S5-S5 in FIG. 5 showing an enlarged view of one of four image forming units (process cartridges). FIG. 2 is an external perspective view of the entire image forming apparatus showing a state in which a front cover of the main body case is closed. It is a perspective view of the principal part explaining the positional relationship between each image forming unit and the flow dividing duct with the front cover of the main body case opened. It is the perspective view which looked at the image formation unit from the front diagonal side of the direction of order. (A) is a front view showing a state where a front cover is attached to the unit front end of the image forming unit, and (b) is a front view showing a state where the front cover is removed and the drive mechanism and the like of the unit front end are exposed. It is the perspective view which looked at the image forming unit from the back slant side of the front-back direction. FIG. 6 is a perspective view mainly showing a back side shape and a downstream side of a development side air flow path in a single rear cover state. (A) is a rear view showing a state in which a rear cover is attached to the rear end of the image forming unit, and (b) is a rear view showing a state in which the rear cover is removed and the unit driving mechanism and the like at the rear end of the unit are exposed. is there. It is a top view which shows a development drive transmission mechanism and a unit drive mechanism. (A) is a partial cross-sectional top view explaining the assembly | attachment shape state of the conveyance screw idler gear which comprises a unit drive mechanism, and its axis | shaft, (b) is a front view of (a). FIG. 6 is a rear view showing a development-side air flow path and air flow on the rear end side of a unit to which the rear cover is mounted, with a part of the rear cover broken away. (A) is an expanded sectional view of the principal part explaining a state before a guide part is inserted in a sheet metal frame, and (b) a state when a guide part is inserted in a sheet metal frame, respectively. FIG. 6 is a cross-sectional view of a main part for explaining a state in which one end portion of a developing roller shaft is in contact with an inclined portion for applying a developing bias when a rear cover is attached to a rear end portion of a unit. It is a perspective view which shows the 1st drive transmission mechanism which transmits the drive force of a photoconductor drive motor. It is a perspective view which shows the structure by the side of the apparatus main body of a 1st drive transmission mechanism. FIG. 4 is a perspective view illustrating a configuration of an image forming unit (process cartridge) side of a first drive transmission mechanism. It is a perspective view of the principal part which shows the structure by the side of the ventilation which ventilates to each image formation unit. It is a partial cross section perspective view of the principal part which shows the structure by the side of the exhaust which exhausts from each image formation unit.

  DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments of the present invention including examples will be described in detail with reference to the drawings. In the embodiments and the like, components (members and components) having the same function, shape, and the like will be omitted by giving the same reference numerals after being described once unless there is a possibility of confusion.

An embodiment of an image forming apparatus to which the present invention is applied will be described with reference to FIG. FIG. 1 is a schematic configuration diagram of an entire image forming apparatus showing an embodiment of the present invention. An image forming apparatus 1 shown in the figure is a tandem indirect transfer type image forming apparatus.
As shown in FIG. 1, an image forming unit 3, an optical writing device 4, a paper feed cassette 5, a fixing device 6, a waste toner collecting container 7, and the like are included in a main body case 2 as an apparatus main body of the image forming apparatus 1. It is arranged (means that it is provided by being arranged, or provided at a determined position). The main body case 2 includes a housing, a case-like skeleton, and a frame on the image forming apparatus 1 side.
The image forming unit 3 is also called a printer engine, and is a part that forms a toner image and transfers the formed toner image to a recording medium. The optical writing device 4 is a portion that emits a light beam toward an image carrier, which will be described later, constituting the image forming unit 3. The paper feed cassette 5 is a recording medium storage unit that stores a sheet-like recording medium P that is a transfer target. The fixing device 6 is a part for fixing the recording medium P to which the toner image is transferred. The waste toner collection container 7 is a part for collecting waste toner generated after transferring the toner image.

  The image forming unit 3 includes four image forming units 23Y, 23M, 23C, and 23K corresponding to yellow (Y), magenta (M), cyan (C), and black (K) toners from the left side of FIG. They are arranged in this order toward the right side. In addition to the above configuration, the image forming unit 3 includes a primary transfer roller 12 disposed corresponding to each of the image forming units 23Y, 23M, 23C, and 23K, an intermediate transfer belt 13 as an intermediate transfer member, and a secondary transfer roller. A transfer roller 14 and the like are disposed.

  Since any image forming unit of the four image forming units 23Y, 23M, 23C, and 23K has the same configuration, the subscripts Y, M, C, and K representing the distinction of colors are appropriately displayed starting with FIG. Omitted. Further, in the description of the image forming unit 23, the subscripts Y, M, C, and K representing the distinction of colors are omitted as appropriate for the sake of simplicity. In FIG. 1, only the four image forming units 23Y, 23M, 23C, and 23K and the four photoconductors 8Y, 8M, 8C, and 8K are provided with subscripts Y, M, C, and K that indicate color distinction. ing.

  FIG. 2 is an enlarged schematic sectional view showing one of the four image forming units 23 described above, and is also a sectional view taken along the line S5-S5 in FIG. The image forming unit 23 shown in FIG. 2 has a function and configuration as an example of the detachable unit of the present invention, and the basic configuration except the configuration of the characteristic portion according to the present invention is the same as that of a known image forming unit. It has become. That is, as shown in FIG. 2, the image forming unit 23 has a function / configuration as an example of a process cartridge and is detachable from the main body case 2.

  As shown in FIG. 2, the image forming unit 23 includes a photoconductor 8 as an image carrier, a charging roller 9 as a charging unit, a developing device 10 as a developing unit, and a photoconductor cleaning device 11 as a cleaning unit. The unit main body 100 is provided integrally. The unit main body 100 represents a skeleton / frame portion as a unit apparatus main body on the image forming unit 23 side. Since the photoconductor 8, the charging roller 9, the developing device 10, and the photoconductor cleaning device 11 are unitized as a process cartridge, replacement and maintenance work can be facilitated and the positional accuracy between the members can be maintained with high accuracy. Therefore, the quality of the formed image can be improved.

  In this embodiment, the image forming unit 23 itself as a process cartridge is replaced. However, there are various process cartridge configurations. For example, a configuration in which at least one of the charging roller 9, the developing device 10, and the photoconductor cleaning device 11 and the photoconductor 8 are housed in a unit main body may be used. Alternatively, the image forming unit 23 may be removed from the main body case 2 and replaced with a new one in units such as the photoconductor 8, the charging roller 9, the developing device 10, and the photoconductor cleaning device 11.

With reference to FIG. 1 and FIG. 2, the image forming process will be described while supplementing the detailed configuration. The photoconductor 8 is formed in a cylindrical shape, and is connected to a single photoconductor drive motor M1 that is a drive source of the photoconductor 8 via a drive transmission unit having a gear train described later. The photoconductor 8 rotates around the central axis by the driving force from the photoconductor drive motor M1. A photosensitive layer on which an electrostatic latent image is formed is provided on the outer peripheral surface of the photoreceptor 8. The charging roller 9 is disposed in the vicinity of the outer peripheral surface of the photoconductor 8. When a voltage is applied to the charging roller 9 from a power supply unit (not shown) (meaning that a voltage is applied), the outer peripheral surface of the photoconductor 8 is uniformly charged. Reference numeral 9a denotes a charging cleaning roller for cleaning the charging roller 9.
The drive source of the photoconductor 8 is not limited to the example of driving by the single photoconductor drive motor M1 as described above, and may be as follows. For example, the photosensitive member 8K (black) and the intermediate transfer belt 13 are driven by a common driving motor, and the three-color photosensitive members 8Y, 8M, and 8C are driven by a common driving motor different from the above. .

The optical writing device 4 emits a light beam corresponding to the image data, and exposes the outer peripheral surface of the uniformly charged photoreceptor 8. By this exposure, an electrostatic latent image corresponding to the image data is formed on the outer peripheral surface of the photoreceptor 8.
The developing device 10 supplies toner as a developer to the photoreceptor 8. The supplied toner adheres to the electrostatic latent image formed on the outer peripheral surface of the photoconductor 8, and the electrostatic latent image on the outer peripheral surface of the photoconductor 8 is visualized as a toner image. As the developer, a two-component developer containing toner and carrier is used, but a one-component developer containing no carrier may be used.

  The intermediate transfer belt 13 is an endless / loop belt formed of a resin film or rubber as a base, and is wound around a driving roller 16, an entrance roller 17, and a tension roller 18. The intermediate transfer belt 13 rotates in the direction of arrow A when a driving roller 16 connected to a driving motor (not shown) is driven to rotate. The entrance roller 17 and the tension roller 18 are driven to rotate by the frictional force with the intermediate transfer belt 13 as the intermediate transfer belt 13 rotates in the direction of arrow A.

  The primary transfer roller 12 is disposed on the inner peripheral surface side (inside the loop) of the intermediate transfer belt 13, and a transfer voltage (primary transfer bias) is applied to these primary transfer rollers 12. The toner image on each photoconductor 8 is transferred onto the intermediate transfer belt 13. The toner images formed on the respective photoreceptors 8 are sequentially transferred and superimposed on the intermediate transfer belt 13, and a color toner image is formed on the intermediate transfer belt 13.

  The color toner image formed on the intermediate transfer belt 13 is transferred to the secondary transfer roller 14 at the timing when the recording medium P is sent to the transfer position where the intermediate transfer belt 13 and the secondary transfer roller 14 are in contact with each other. When the working voltage is applied, it is transferred to the recording medium P. The recording medium P is fed and fed from the inside of the paper feed cassette 5 and is conveyed by the conveyance roller 19 and the registration roller 20, and is transferred to the fixing device 6 after the toner image is transferred. The recording medium P to which the toner image has been transferred is subjected to fixing processing by applying heat and pressure in the fixing device 6, and the toner image melted by this fixing processing is fixed to the recording medium P. The recording medium P for which the fixing process has been completed is conveyed and discharged by a discharge roller or the like, and discharged onto a discharge tray 21 formed on the upper surface of the main body case 2.

  The photoconductor cleaning device 11 cleans the outer peripheral surface of the photoconductor 8 after the toner image is transferred to the intermediate transfer belt 13. By this cleaning, toner, paper dust, and the like remaining on the outer peripheral surface of the photoreceptor 8 after the toner image is transferred to the intermediate transfer belt 13 are collected as waste toner. Further, the photoconductor cleaning device 11 includes a lubricant supply mechanism that supplies a lubricant to the outer peripheral surface of the photoconductor 8 after cleaning.

  The photoconductor cleaning device 11 includes a cleaning blade 61, a coating roller 62 that is a rotary body, and a leveling blade 66 in this order from the upstream side in the rotation direction (surface movement direction) indicated by the arrow in the drawing of the photoconductor 8. In the photoconductor cleaning device 11, the toner is removed by the cleaning blade 61. The cleaning blade 61 is fixed to the holder, and is supported so as to abut on the surface of the photoconductor 8 in the counter direction with respect to the surface movement direction of the photoconductor 8 (meaning that it contacts the abutted state). ing. The cleaning blade 61 is configured to abut against the photosensitive member 8 by a pressure spring (not shown) so as to remove toner.

A lubricant supply mechanism is configured by the configuration in which the application roller 62 and the solid lubricant 64 held by the solid lubricant holding member are pressed against the application roller 62 by the lubricant pressure spring 68.
As shown in FIG. 2, a unit front end portion 100 a (with parentheses) provided with a unit front side plate (not shown) or the like is disposed on the front side of the drawing of the unit main body 100. Further, a unit rear end portion 100b having a unit rear side plate (not shown) is disposed on the back side of the drawing of the unit main body 100 in the drawing. The application roller 62 is rotatably supported by the unit front end portion 100a and the unit rear end portion 100b via a shaft. The application roller 62 is a rotating body that comes into contact with the outer peripheral surface of the photoconductor 8. The outer peripheral portion is formed of a sponge that is an elastic body, and the lubricant removed from the solid lubricant 64 is applied to the outer peripheral surface of the photoconductor 8. It has a function to apply. The application roller 62 rotates in the counter direction with respect to the surface movement direction of the photoconductor 8.

  The intermediate transfer cleaning device 15 cleans the outer peripheral surface of the intermediate transfer belt 13 after the color toner image is transferred to the recording medium P. By this cleaning, toner, paper dust, and the like remaining on the outer peripheral surface of the intermediate transfer belt 13 after the toner image is transferred are collected as waste toner.

  The waste toner collection container 7 is a portion in which waste toner collected by the photoconductor cleaning device 11 and the intermediate transfer cleaning device 15 is input and the input waste toner is stored. The waste toner collection container 7 is detachably attached to the main body case 2, and is removed from the main body case 2 when the waste toner in the waste toner collection container 7 is almost full. A container 7 is attached.

Next, the common configuration and operation of each image forming unit 23 will be described in more detail with reference to FIG.
Each image forming unit 23 includes a photoconductor 8 that is an image carrier or a latent image carrier, and a charging roller 9 that charges the surface of the photoconductor 8. Further, the image forming unit 23 irradiates the electrostatic latent image formed on the photosensitive member 8 by irradiating the surface of the photosensitive member 8 charged by the charging roller 9 with the laser light L from the optical writing device 4. A developing device 10 that supplies toner and develops it is provided.

  The residual toner remaining on the surface of the photoconductor 8 after the toner image is transferred to the intermediate transfer belt 13 in the primary transfer portion is removed by the cleaning blade 61. The toner removed by the cleaning blade 61 is transported out of the photoconductor cleaning device 11 by the transport screw 67.

  A lubricant is applied to the outer peripheral surface of the photoconductor 8 from which the toner has been removed by the cleaning blade 61 by an application roller 62 that contacts the outer peripheral surface of the photoconductor 8. The lubricant used here is a mixture of zinc stearate, boron nitride, and alumina, and solidified by compression molding to obtain a solid lubricant 64. The lubricant is supplied to the outer peripheral surface of the photoconductor 8 as follows. That is, in a state where the solid lubricant 64 is pressed against the application roller 62 by the lubricant pressure spring 68, the application roller 62 rotates in the rotation direction of the photoconductor 8 and the counter direction, thereby removing the solid lubricant 64. And coated on the outer peripheral surface of the photoreceptor 8. The application roller 62 may be configured to rotate in the rotation direction and the trailing direction of the photoconductor 8.

The lubricant that has been scraped from the solid lubricant 64 by the application roller 62 and adhered to the surface of the photoreceptor 8 in powder form is a fixed pressure type leveling blade 66 that is supported so as to contact the surface of the photoreceptor 8. Is leveled on the photoconductor 8.
Each image forming unit 23 removes the transfer residual toner on the photoconductor 8 as described above, applies a lubricant, and prepares for the next image formation starting from uniform charging by the charging roller 9.
The application roller 62 and the conveying screw 67 are connected to a single photosensitive member driving motor M1 that is a driving source of the photosensitive member 8 via a driving transmission unit having a gear train described later, and the photosensitive member driving motor M1 is rotationally driven. To rotate.

The developing device 10 includes a developing roller 35 as a developer carrying member for carrying the developer supplied to the photosensitive member 8, two first stirring and conveying screws 36 as rotating bodies for stirring and conveying the developer, and a second agitating device. A conveying screw 37 and a doctor blade 38 as a developer layer thickness regulating member are provided. The developing roller 35 is rotatably provided via a developing roller shaft 35 a supported by a developing case 39 that is a developing container of the developing device 10. The developing roller shaft 35a functions as a developer carrying member shaft, and is formed of, for example, a stainless steel conductive member, to which a developing bias (voltage) is applied.
The developing roller 35, the first agitating and conveying screw 36, and the second agitating and conveying screw 37 are connected to a developing drive motor M2 as a single developer carrier driving means via a drive transmitting means having a gear train described later. The developing drive motor M2 is rotated by being driven to rotate.

FIG. 3 is a perspective view showing a state in which the front cover 24 as an opening / closing member provided on the front / front side of the main body case 2 so as to be openable / closable is closed, and FIG. 4 shows each image formation with the front cover 24 opened. 4 is a perspective view of a main part for explaining the positional relationship between a unit 23 and a flow dividing duct 40. FIG. 3 and 4, X is the front-rear direction of the image forming apparatus 1, Y is the left-right direction (also the width direction) of the main body case 2 orthogonal to the front-rear direction X, and Z is the front-rear direction X and the left-right direction. The vertical direction (also the height direction) perpendicular to the direction Y is shown.
The front cover 24 occupies a closed position when it is closed with respect to the main body case 2 as shown in FIG. 3, and occupies an open position when it is released from the main body case 2 as shown in FIG. On the side wall of the front cover 24, a louver portion 24a for taking in outside air is formed. As shown in FIG. 4, by opening the front cover 24, the image forming unit 3 and a waste toner collecting container (not shown) appear, and each color image forming unit 23 and intermediate transfer belt and waste toner collecting (not shown) are collected. Container replacement and other maintenance can be performed.

  As shown in FIG. 4, a shunt duct 40, which is a shunt duct member, is attached and fixed to the back side of the front cover 24 by fastening means such as screws. The branch duct 40 is integrally formed with a collection port 41 formed at the right end of the drawing, and a first distribution port 42 and a second distribution port 43 provided corresponding to each image forming unit 23. Yes. The collection port 41 collects and receives an air flow that is forcibly blown from a blower fan 103 as a blower provided in the main body case 2. The first distribution port 42 is inserted into the developing side introduction port 26 of the front cover 25 provided for each image forming unit 23 when the front cover 24 occupies the closed position, and the received air flow is divided to form an image. This is distributed for each unit 23. The second distribution port 43 is inserted into the charging side introduction port 27 of the front cover 25 provided for each image forming unit 23 when the front cover 24 occupies the closed position, and the received air flow is divided to form an image. This is distributed for each unit 23.

A more specific configuration of the image forming unit 23 will be described with reference to FIGS. FIG. 5 is a perspective view of the image forming unit 23 as viewed from the front oblique side in the front-rear direction X. 6A shows a state where the front cover 25 is attached to the unit front end portion 100a of the image forming unit 23, and FIG. 6B shows a state where the front cover 25 is removed and the drive mechanism and the like of the unit front end portion 100a are exposed. FIG. FIG. 7 is a perspective view of the image forming unit 23 as seen from the rear oblique side in the front-rear direction X.
As described above, the image forming unit 23 can be attached to and detached from the main body case 2 in the front-rear direction X, which is the predetermined attaching / detaching direction shown in FIGS. And a charging roller 9 shown in FIG.

As shown in FIGS. 5 and 7, the image forming unit 23 includes a front cover as an example of a cover member that covers a driving mechanism (to be described later) of the image forming unit 23 on one end side and the other end side in the front-rear direction X of the unit main body 100. 25 and a rear cover 45. A front cover 25 as one cover member is detachably provided on the unit front end portion 100a which is one end side in the front-rear direction X of the unit main body 100. The unit front end portion 100a is provided with a first stirring and conveying screw gear 36A fixed to the front end portion of the shaft 36a of the first stirring and conveying screw 36, and a second stirring and conveying screw gear 37A that meshes with the first stirring and conveying screw gear 36A. Yes.
As described above, the first stirring and conveying screw gear 36A rotates integrally with the shaft 36a. The second agitating / conveying screw gear 37A is fixed to the front end portion of the shaft 37a of the second agitating / conveying screw 37, and rotates integrally with the shaft 37a.

  The first agitating and conveying screw 36, the shaft 36a, the second agitating and conveying screw 37, the shaft 37a, the first agitating and conveying screw gear 36A and the second agitating and conveying screw gear 37A have a function as a drive mechanism for the rotating body and the unit front end portion 100a. . The front end portion of the shaft 36a of the first agitating and conveying screw 36 and the front end portion of the shaft 37a of the second agitating and conveying screw 37 constituting this drive mechanism are exposed from the unit front end portion 100a. Further, the first agitation transport screw gear 36A and the second agitation transport screw gear 37A are also exposed from the unit front end portion 100a. The front end of the shaft 36a exposed from the unit front end 100a, the front end of the shaft 37a, the rotating portion including the first stirring / transporting screw gear 36A and the second stirring / transporting screw gear 37A are covered with at least the front cover 25. Will be.

  A rear cover 45 as the other cover member is detachably provided on the unit rear end portion 100b on the other end side in the front-rear direction X of the unit main body 100. Detailed configurations of the unit rear end portion 100b and the rear cover 45 will be described later. Reference numeral 101 c denotes a toner supply port for supplying toner as a developer to the developing device in the unit main body 100.

  The front cover 25 and the rear cover 45 are integrally formed with an appropriate resin and have a shape that will be described later, thereby reducing weight and contributing to cost reduction. As shown in FIGS. 5 and 7, the front cover 25 and the rear cover 45 can be attached to and detached from the unit front end portion 100 a and the unit rear end portion 100 b of the unit body 100 through screws 29 as first fastening members. It is configured.

  In the front cover 25, a flange 25a extending rearward in the front-rear direction X so as to cover the drive mechanism of the unit front end portion 100a is formed over the substantially outer peripheral shape of the front cover 25. Although there is a partial difference in the flange length of the front cover 25, the front cover 25 is fitted with an outer peripheral shape of the unit front end portion 100a and an engagement relationship of each portion with a concavo-convex shape. Thus, the front cover 25 has a shape that substantially seals the front end portion 100a of the unit so that leakage of air blown from the main body case 2 shown in FIG. In addition, by fastening one central lower portion of the front cover 25 with the screw 29, the front cover 25 can be securely fixed without being lifted or rattling.

  The front cover 25 is integrally formed with a developing side introduction port 26, a charging side introduction port 27, and a screw mounting hole 28. The development side introduction port 26 has a function as a first introduction port that introduces air from the main body case 2 side shown in FIG. 4 and the like and guides it into the image forming unit 23. The upstream side of the side air flow path 30 is formed. The charging side introduction port 27 has a function as a first introduction port that introduces air from the main body case 2 and guides it into the image forming unit 23. Forms the upstream side. As shown in FIG. 6, the screw attachment hole 28 is a part for fastening and fixing the front cover 25 to the female screw hole 34 formed in the unit front end portion 100 a via the screw 29.

The unit front end portion 100a of the image forming unit 23 is a second fastening member with respect to a main body front side plate (not shown) fixed to the front end portion in the front-rear direction X of the main body case 2 shown in FIGS. It can be attached and detached via a screw (not shown). As shown in FIG. 6 (b), a unit screw mounting hole 33 for fastening the image forming unit 23 to the main body front side plate of the main body case 2 via the screw is formed in the unit front end portion 100a. Has been.
As shown in FIGS. 5 and 6, the fastening position of a unit screw mounting hole 33 of a screw (not shown) to the main body case 2 of the unit front end portion 100 a and the fastening position of the screw 29 to the unit front end portion 100 a of the front cover 25 Is different. When the unit front end 100a of the image forming unit 23 is fastened to the main body case 2 via a screw (not shown) and the front cover 25 is fastened to the unit front end 100a via a screw 29, a screw (not shown) is attached by the front cover 25. And the unit screw mounting hole 33 is hidden.
According to the present embodiment, as described above, the image forming unit 23 cannot be detached from the main body case 2 without first removing the front cover 25 from the unit front end portion 100a of the image forming unit 23. . The front cover 25 and the rear cover 45 are configured to be detachable from the unit front end portion 100a and the unit rear end portion 100b of the unit main body 100 through screws 29. Thereby, when the image forming unit 23 is replaced, the front cover 25 and the rear cover 45 can be reused, so that it is possible to contribute to resource saving and cost reduction.

In the image forming unit 23, as shown in FIGS. 5 and 6, etc., a developing duct 32 as an example of a duct member that forms an air flow path between the front cover 25 and the rear cover 45 extends in the front-rear direction X. Is provided. The rear end portion of the developing duct 32 in the front-rear direction X is connected to the developing rear side introduction port 46 of the rear cover 45 shown in FIG. The developing duct 32 is manufactured by resin molding (for example, injection molding) because it is necessary to ensure a certain degree of shape accuracy. For this reason, as shown in the figure, it is impossible to manufacture with a closed cross-section (generally unequal trapezoidal trapezoidal shape) because of die cutting, so a single development duct is manufactured with an open top. When a single development duct is attached to the unit main body 100, the upper opening portion is closed using a partial shape of the bottom wall surface of the unit main body 100 to form a closed cross-sectional shape. A part of the bottom wall surface of the unit main body and the assembly / combination part of the developing duct 32 alone are in close contact with an appropriate sealing material such as a sponge.
The developing duct 32 is not limited to the above-described manufacturing method, and may be divided and manufactured at an appropriate portion in the longitudinal direction X, and the divided products may be used by fitting and connecting them. In addition, when it is not necessary to ensure the shape accuracy of the developing duct 32, it is possible to manufacture the developing duct 32 with a closed cross-sectional shape by, for example, blow molding.
As shown in FIG. 5, the front end portion of the developing duct 32 is slightly different from the rear end portion of the developing side introduction port 26 for the convenience of the air flow path layout in order to improve the mounting workability to the front end portion 100a of the front cover 25. It is provided with a gap.

  As shown in FIG. 6, the first agitating / conveying screw gear 36 </ b> A and the second agitating / conveying screw gear 37 </ b> A are arranged so as to be obliquely shifted in the vertical direction. The development duct 32 is disposed using the surplus space, and is attached and fixed via a fastening member such as a screw.

As described above, according to the present embodiment, the developing duct 32 as a duct member is arranged using the above-described surplus space of the unit main body 100 and contributes to the downsizing of the image forming unit 23.
Further, between the front cover 25 and the unit front end portion 100a of the unit main body 100, the front end portion of the shaft 36a of the first agitating and conveying screw 36 and the front end portion of the shaft 37a of the second agitating and conveying screw 37 constituting the drive mechanism. Is exposed from the unit front end 100a. The air blown from the main body case 2 hits these exposed shafts to some extent (when compared with the rear cover 45 covering the drive mechanism of the unit rear end portion 100b) and the developing side introduction port 26 and the developing side airflow of the front cover 25. A path 30 is formed. As a result, the front end portion of the shaft 36 a of the first agitating and conveying screw 36 and the front end portion of the shaft 37 a of the second agitating and conveying screw 37 can be always cooled with air blown from the main body case 2.

  As shown in FIG. 6, the duct member for the charging device connected to the rear end portion of the charging side introduction port 27 on the unit front end portion 100 a side facing the rear end portion of the charging side introduction port 27 in the front cover 25. The charging duct 101 is disposed. The charging duct 101 is not formed long so as to communicate with the rear cover 45 like the developing duct 32, and the airflow (from the charging side introduction port 27 to the front end of the charging roller 9 shown in FIG. It is formed relatively short so as to guide the wind.

As shown in FIG. 5, the air introduced from the charging side introduction port 27 and sent via the charging duct 101 is charged by the gap between the vicinity of the charging roller 9 shown in FIG. 2 and the optical writing device 4. It passes through the side air flow path 31 and is sent further back in the front-rear direction X. Then, the air is collected by the rear cover 45 and exhausted to a discharge port 47 shown in FIGS.
The reason for cooling the vicinity of the charging device including the charging roller 9 is to prevent the uniform charging function of the charging roller 9 from failing to function due to the change in the electrical resistance value of the charging roller 9 depending on the temperature. This is to prevent it in advance.
As described above, according to the present embodiment, the vicinity of the charging device including the charging roller 9 can be cooled, so that the uniform charging function of the charging roller 9 is always ensured to prevent abnormal images from occurring. Can be prevented.

The rear cover 45 and the unit rear end portion 100b will be described with reference to FIGS. FIG. 8 is a perspective view mainly showing the back side shape and the downstream side of the development side air flow path 30 in the state of the rear cover 45 alone. 9A shows a state in which the rear cover 45 is attached to the unit rear end portion 100b of the image forming unit 23, and FIG. 9B shows a state in which the rear cover 45 is removed and the unit drive mechanism 52 and the like of the unit rear end portion 100b are installed. It is a rear view which shows each exposed state.
In the rear cover 45, a flange 45a extending toward the front Xa in the front-rear direction X so as to cover a drive mechanism described later of the unit rear end portion 100b is formed over substantially the entire outer peripheral shape of the rear cover 45. It fits loosely with each part of the rear end 100b. As described above, the rear cover 45 has a shape that substantially seals the rear end portion 100b of the unit so that leakage of air blown from the development side introduction port 26 of the front cover 25 through the development duct 32 is reduced. .

As shown by a two-dot chain line in FIG. 8, the rear cover 45 has a development rear side introduction port 46 as a second introduction port for introducing air guided into the image forming unit 23, and a development rear side introduction port. A discharge port 47 for discharging the air introduced from 46 to the main body case 2 side is integrally formed. When the rear cover 45 is inserted and attached to the rear end of the unit with the front Xa in the front-rear direction X, the rear end opening of the development duct 32 indicated by a two-dot chain line is slightly different from the rear development side introduction port 46 of the rear cover 45. Connect with a gap of. At the same time, the unit discharge port 102 indicated by a two-dot chain line provided at the lower part of the rear end portion of the unit is connected to the discharge port 47 of the rear cover 45 with a slight gap. Here, “connecting with a slight gap” does not mean that the connection is made in a tightly fitted state with no gap at all, but does not impair the basic function of communication. This means that the connection is connected with a slight margin.
An air flow indicated by a thick arrow in the drawing is formed by the development rear side introduction port 46 and the discharge port 47 formed in the rear cover 45, thereby forming a downstream side of the development side air flow path 30 by the rear cover 45 itself. Yes. When the rear cover 45 is attached to the unit rear end portion 100b, the development-side air flow path 30 forms a branch flow path as will be described later depending on the arrangement relationship of the drive mechanism covered in the rear cover 45 (see FIG. 12). Further, as shown in FIG. 8, the air flow sent via the charging side air flow path 31 shown in FIG. 5 is collected on the back wall of the rear cover 45 to form the downstream side of the charging side air flow path 31. Exhausted to the outlet 47.

Next, a unit drive mechanism that is a drive mechanism on the unit rear end 100b side will be described with reference to FIGS. FIG. 10 is a plan view showing the configuration of the development drive transmission mechanism 110 that is the main body drive mechanism of the developing device on the main body case 2 side and the configuration of the unit drive mechanism 52. 11A is a partial cross-sectional plan view for explaining the assembled shape state of the transport screw idler gear 57 and the shaft 57a constituting the unit driving mechanism 52, and FIG. 11B is a front view of FIG. 11A. is there. In FIG. 10, the distance between the shaft pitches is ignored in order to clarify the meshing state of the gears.
As shown in FIG. 10, the development drive transmission mechanism 110 is connected to a development gear train 116 having a plurality of development gears that transmit the drive of the development drive motor M2, and an end gear (not shown) of the development gear train 116. And a developing joint member 114 for transmitting the driving of the developing gear train 116. The development joint member 114 includes a development joint gear (not shown) that meshes with the end gear (not shown) and a female joint 115. The development drive motor M2 is fixed to the main body rear plate 105 disposed on the rear side (back side) of the front and rear direction X of the main body case 2 shown in FIG. Has been.

  In the present embodiment, the female joint 115 is composed of a developing involute spline female part having a particularly high meshing rate among spline joints. In this embodiment, a spline joint is used for drive transmission from the apparatus main body side to the image forming unit 23 side which is a process cartridge. The spline joint has a high meshing rate because the inner teeth formed on the inner circumferential surface of the cylindrical female portion and the outer teeth formed on the outer circumferential surface of the shaft mesh with each other. Therefore, by using a spline joint, meshing vibration at the joint portion can be suppressed. In particular, by using an involute spline joint, the meshing rate can be further increased, and meshing vibration at the joint can be further suppressed. Thereby, the speed fluctuation of the developing roller 35, the speed fluctuation of the photosensitive member 8, and the speed fluctuation of the coating roller 62 described later can be suppressed by the meshing vibration in the joint portion. In the case where the above advantages / effects are not so desired, not only spline joints but also known shaft joints may be used.

  The unit drive mechanism 52 includes a male joint 53, a drive gear 54, a drive small-diameter gear 55, a developing idler gear 56, a transport screw idler gear 57, and a transport screw gear 58, as shown in FIGS. The male joint 53 functions as a first unit drive mechanism that is connected to the female joint 115 of the development drive transmission mechanism 110, is formed of an appropriate resin, for example, polyacetal resin, and includes an involute spline male part. In FIG. 9, by moving the image forming unit 23 shown in parentheses toward the rear Xa in the front-rear direction X, the male joint 53 of the unit drive mechanism 52 moves into the female joint 115 of the development drive transmission mechanism 110. And the drive transmission state of the development drive motor M2 is entered.

  The driving gear 54, the driving small-diameter gear 55, the developing idler gear 56, the conveying screw idler gear 57, and the conveying screw gear 58 are formed of appropriate resin and function as a second unit driving mechanism. The shaft 55a of the driving small-diameter gear 55, the shaft 56a of the developing idler gear 56, the shaft 57a of the transport screw idler gear 57, and the shaft 36a of the transport screw gear 58 are made of metal, for example, formed of stainless steel. In addition, the axis | shaft 36a of the conveyance screw gear 58 is coaxial with the axis | shaft 36a of the 1st stirring conveyance screw 36 shown in FIG. Each of the gears constituting the second unit drive mechanism is in a drive transmission relationship with the male joint 53, and is a first agitating and conveying screw 36, a second agitating and conveying screw 37, which are rotating bodies in the image forming unit 23, and a developing unit. The roller 35 and the like are driven.

  The drive gear 54 is integrally provided coaxially with the male joint 53. The drive small-diameter gear 55 is integrally provided coaxially with the male joint 53 and the drive gear 54. The drive small-diameter gear 55 is configured to rotate while sliding in contact with the shaft 55a (hereinafter also referred to as “sliding contact”). The development idler gear 56 is an idler / intermediate gear that meshes with the drive small-diameter gear 55, and is configured to rotate while sliding on the shaft 56a. It engages with a developing roller gear (not shown) provided on the developing roller shaft 35a. The transport screw idler gear 57 is configured to mesh with the drive gear 54 and rotate while being in sliding contact with the shaft 57a of the transport screw idler gear 57 (see FIG. 11). The transport screw gear 58 meshes with the transport screw idler gear 57 and is provided integrally with the first agitation transport screw shaft 36a.

As shown in FIGS. 9B and 11, the shaft 57a of the conveying screw idler gear 57 is fixed to a frame member 60 having a metal thin plate shape provided at the unit rear end portion 100b. The movement of the conveying screw idler gear 57 in the direction of the shaft 57a is restricted by a retaining ring 59 attached to the shaft 57a. A minute predetermined gap is provided between the shaft hole of the transport screw idler gear 57 and the outer diameter of the shaft 57a. The resin-made transport screw idler gear 57 rotates at a high speed while being in sliding contact with the metal shaft 57a, whereby the metal shaft 57a generates frictional heat. The frictional heat is transferred to the frame member 60 and further transferred to the conveying screw gear 58 supported by the frame member 60, whereby the heat is transferred to the shaft 36a of the first agitating and conveying screw 36 shown in FIG. Will be. This heat raises the temperature of the first agitating / conveying screw 36 and easily causes problems such as melting and coagulation of the toner in the developer.
The shaft 55a of the drive small-diameter gear 55 fixed to the similar frame member 60 has the same configuration as described above, and the metal shaft 55a generates frictional heat, and the first agitating and conveying screw 36 in the same manner as described above. There is a possibility that the temperature rises and the above-mentioned problems are likely to occur.

  As shown in FIGS. 7 and 9, the rear cover 45 covers the second unit driving mechanism provided at the unit rear end portion 100 b and exposes the male joint 53 that is the first unit driving mechanism. It has a configuration with a shape.

With reference to FIG. 12, the developing-side air flow path 30 and the air flow on the unit rear end 100b side where the rear cover 45 is mounted will be described. FIG. 12 is a rear view showing the development-side air flow path 30 and the air flow on the unit rear end 100b side where the rear cover 45 is mounted, with a part of the rear cover 45 broken away.
As shown in FIG. 12, the rear cover 45 is developed as an air flow path that passes through the second unit drive mechanism (drive gear 54, drive small-diameter gear 55, development idler gear 56, conveyance screw idler gear 57, conveyance screw gear 58). A downstream side of the side air passage 30 is formed.

The air flow sent from the developing duct 32 that forms the upstream side of the developing side air flow path 30 is shown in FIG. 8 that surrounds the periphery of the second unit driving mechanism, as indicated by a thick broken line in FIG. A downstream side of the development side air flow path 30 is formed. At the same time, the air flow sent from the developing duct 32 wraps around the lower part of the transport screw gear 58 and the transport screw idler gear 57 to form the first diversion air flow path 30a. Further, the air flow sent from the developing duct 32 forms a second diversion air flow path 30 b that passes between the conveyance screw gear 58, the conveyance screw idler gear 57 and the drive gear 54 on the downstream side.
As described above, between the rear cover 45 and the unit drive mechanism 52, the shaft 54a of the drive gear 54 and the drive small-diameter gear 55, the shaft 56a of the developing idler gear 56, the shaft 57a of the transport screw idler gear 57, and the transport screw gear 58 are provided. The shaft 36a is exposed. Each of the shafts (the shaft 54a, the shaft 56a, the shaft 57a, and the shaft 36a) is formed with a developing-side air flow channel 30 (a first diverted air flow channel 30a and a second diverted air flow channel 30b) as an air flow path so that the air hits it. ing.

  As described above, according to the present embodiment, even if heat is generated by the second unit driving mechanism covered with the rear cover 45, it is always cooled by the air flow sent from the development-side air flow path 30. It is possible to prevent problems such as melting and coagulation of the toner in the agent. In addition, the drive mechanisms of the unit front end 100a and the unit rear end 100b can be efficiently cooled without increasing the size of the apparatus.

As shown in FIGS. 7 and 9, the rear cover 45 has a guide portion 49 that guides the image forming unit 23 when the image forming unit 23 is attached to the main body case 2 shown in FIG. 4 and the like. The guide portion 49 has a distal end projecting rearward in the front-rear direction X, and is integrally formed with the rear cover 45. The distal end portion of the guide portion 49 has a tapered shape having a taper.
With reference to FIG. 13, the positional relationship between the guide portion 49 and the sheet metal frame 106 and the function of the guide portion 49 will be described. FIG. 13A is an enlarged cross-sectional view of a main part for explaining a state before the image forming unit 23 and the guide part 49 shown in parentheses are inserted and attached to the sheet metal frame 106 of the main body rear side plate 105. FIG. 13B is an enlarged cross-sectional view of a main part for explaining a state when the image forming unit 23 and the guide part 49 shown in parentheses are inserted and attached to the sheet metal frame 106 of the main body rear side plate 105.
As shown in FIG. 13, a sheet metal frame 106 is fixed to the main body rear side plate 105 (see FIG. 10) on the back side of the main body case 2. As shown in FIG. 13A, from the state before the image forming unit 23 is mounted on the main body rear side plate 105, the image forming unit 23 is moved in the rear direction Xa in the front-rear direction X as shown in FIG. When pushed in and attached to the main body rear side plate 105, the following operation is performed. That is, the guide portion 49 is guided to the rough guide hole 106a formed in the sheet metal frame 106 with a rough guide gap. The relationship between the guide portion 49 and the guide hole 106a of the sheet metal frame 106 is not for positioning the image forming unit 23 but for improving the mountability of the image forming unit 23.
As described above, according to the present embodiment, when the image forming unit 23 is attached to the main body rear side plate 105, the guide portion 49 is roughly guided by the rough guide hole 106 a of the sheet metal frame 106. Workability at the time of mounting on the side plate 105 can be improved.

  As shown in FIG. 9, the rear cover 45 has a hook portion 48 as an elastic attachment portion that comes into contact with and engages with a part of the unit main body 100 of the image forming unit 23 and is elastically deformed. The hook portion 48 is elastically deformed by the elasticity of the resin, and the tip end portion projects forward in the front-rear direction X, and is integrally formed with the lower end on the back surface side of the rear cover 45. The front end portion of the hook portion 48 has a hook-like hook shape, and is elastically deformed by contacting / engaging with a projection portion (not shown) formed at a lower portion of the unit rear end portion 100b which is a part of the unit body 100. Engage in a bullet (meaning to bounce back).

When the rear cover 45 is mounted and fixed to the unit front end portion 100b, the front end portion of the hook portion 48 is elastically engaged with the protruding portion of the unit front end portion 100b, and then the fastening formed on the rear cover 45 is performed. The screw 29 is fastened and fixed to a screw mounting hole 50 (see FIG. 8) as a part.
As described above, according to the present embodiment, the hook portion 48 is elastically engaged with the protruding portion of the unit front end portion 100b, and is fastened and fixed by the screw 29 through the screw mounting hole 50 formed in the rear cover 45. As a result, the rear cover 45 can be securely fixed while restrained from floating. The engagement by the hook portion 48 and the screw fastening are fixing at a portion near the lower right side of the rear cover 45 on the back surface side of the rear cover 45 in FIG. Local float and backlash can be suppressed. That is, the relatively long left flange 45a portion of the rear cover 45 in FIG. 8 is fitted to the outer peripheral shape of the corresponding unit front end portion 100b or an appropriate portion with a concavo-convex engagement shape relationship.

  On the back side of the rear cover 45, which is the inner side of the rear cover 45 facing the unit rear end portion 100b, as an elastically deformable developing bias transmission member that applies a developing bias to the developing roller 35 shown in FIG. A thin copper plate 51 is disposed. The copper plate 51 is attached and fixed by resin baking caulking or the like at an appropriate portion of the back wall surface of the rear cover 45, and the lower end portion is connected to a developing bias applying portion attached to the main body case (apparatus main body) side. . The copper plate 51 is formed with a copper plate inclined portion 51a inclined so as to be elastically deformable.

As shown in FIG. 14, when the rear cover 45 is attached to the unit rear end portion 100b facing the front Xa in the front-rear direction X, one end of the developing roller shaft 35a comes into contact with the copper plate inclined portion 51a. Thereby, in a state where the copper plate inclined portion 51a is elastically deformed as indicated by the solid line from the state indicated by the two-dot chain line, one end portion of the developing roller shaft 35a is surely brought into contact with the copper plate inclined portion 51a.
As described above, according to the present embodiment, when the rear cover 45 is mounted on the unit rear end portion 100b, the one end portion of the developing roller shaft 35a reliably contacts the copper plate inclined portion 51a. A bias can be reliably applied to the developing roller.

  Next, the first drive transmission mechanism 120 that transmits the driving force of the photosensitive member driving motor M1 to the photosensitive member 8, the conveying screw 67, and the application roller 62 shown in FIG. 2 will be described with reference to FIGS. To do. FIG. 15 is a perspective view showing the first drive transmission mechanism 120 that transmits the driving force of the photosensitive member driving motor M <b> 1 to the photosensitive member 8, the conveying screw 67, and the coating roller 62. FIG. 16 is a perspective view showing the configuration of the first drive transmission mechanism 120 on the apparatus main body side. FIG. 17 is a perspective view showing the configuration of the first drive transmission mechanism 120 on the image forming unit 23 (process cartridge) side.

As shown in FIGS. 15 and 16, a drive transmission member 122 and a cleaning female side joint member 123 are provided on the apparatus main body side of the first drive transmission mechanism 120.
The drive transmission member 122 includes a photosensitive member gear portion 122a, a first gear portion 122b, and a photosensitive member involute spline male portion 122c. The photoconductor gear portion 122a meshes with the driving gear 121 of the photoconductor drive motor M1. The first gear portion 122 b is for transmitting driving force to the conveying screw 67 and the application roller 62. The photoreceptor involute spline male part 122 c transmits drive to the photoreceptor 8. The drive transmission member 122 is rotatably attached to the main body rear side plate 105 (see FIG. 10).

  The cleaning female joint member 123 includes a second gear portion 123a that meshes with the first gear portion 122b, and a cleaning involute spline female portion 123b. As shown in FIG. 17, a photoreceptor involute spline female portion 128 that meshes with the photoreceptor involute spline male portion 122 c of the drive transmission member 122 is provided on the rear flange 8 a of the photoreceptor 8. The photoreceptor involute spline male part 122c and the photoreceptor involute spline female part 128 constitute an involute spline joint for photoreceptor.

  Further, as shown in FIG. 17, a cleaning male side joint member 124 and an idler gear 126 (see FIG. 9B) are rotatably attached to the unit rear end portion 100b of the image forming unit 23. The cleaning male side joint member 124 includes a cleaning involute spline male portion 124a that meshes with the cleaning involute spline female portion 123b, and a joint gear portion 124b. The cleaning involute spline male part 124a and the cleaning involute spline female part 123b constitute a cleaning involute spline joint. An application roller gear 125 fixed to the shaft of the application roller 62 and an idler gear 126 are engaged with the joint gear portion 124b. The idler gear 126 meshes with a conveyance gear 127 fixed to the shaft of the conveyance screw 67.

  As the image forming unit 23 is inserted, the photosensitive member involute spline female portion 128 moves in the direction of the arrow X1 shown in FIGS. 16 and 17, and the photosensitive member involute spline male portion 122c is inserted into the photosensitive member involute spline female portion 128. Is done. As a result, the photosensitive member involute spline male portion 122c meshes with the internal teeth of the photosensitive member involute spline female portion 128. As a result, the driving force of the photosensitive member driving motor M1 is transmitted to the photosensitive member 8 via the photosensitive member gear portion 122a and the photosensitive member involute spline joint, and the photosensitive member 8 is rotationally driven.

  Further, the cleaning involute spline male part 124a moves in the direction of the arrow Y1 shown in FIGS. 16 and 17, and the cleaning involute spline male part 124a is inserted into the cleaning involute spline female part 123b. Thereby, the cleaning involute spline male part 124a meshes with the internal teeth of the cleaning involute spline female part 123b. As a result, the driving force of the photosensitive member driving motor M1 is applied to the coating roller via the photosensitive member gear portion 122a, the first gear portion 122b, the second gear portion 123a, the cleaning involute spline joint, the joint gear 124b, and the coating roller gear 125. 62. Thereby, the application roller 62 is rotationally driven. Further, the driving force of the photosensitive member driving motor M1 is transmitted from the joint gear 124b to the conveying screw 67 through the idler gear 126 and the conveying gear 127, and the conveying screw 67 is rotationally driven.

With reference to FIGS. 6, 7, 16, and 17, a supplementary method for positioning the image forming unit 23 with respect to the main body case 2 is described.
Positioning in the left-right direction Y and up-down direction Z on the unit rear end 100b side of the image forming unit 23 with respect to the main body case 2 is performed by inserting / meshing the photosensitive member involute spline female portion 128 into the photosensitive member involute spline male portion 122c. . Positioning in the front-rear direction X, left-right direction Y, and up-down direction Z on the unit front end 100a side is performed by inserting a screw (not shown) through a unit screw mounting hole 33 shown in FIG. This is done by fixing the front end 100a.

With reference to FIGS. 18 and 19, the structure on the air blowing side of each image forming unit 23 and the structure and operation on the exhaust side from each image forming unit 23 will be described. FIG. 18 is a perspective view of a main part showing a configuration on the air blowing side for blowing air to each image forming unit 23. FIG. 19 is a partial cross-sectional perspective view of the main part showing the configuration of the exhaust side exhausted from each image forming unit 23.
FIG. 18 shows the development side introduction of the front cover 25 of the image forming unit 23 to which each first distribution port 42 and each second distribution port 43 of the diversion duct 40 correspond in a state where a front cover (not shown in detail) occupies the closed position. It shows a state where it is inserted into the port 26 and the charging side introduction port 27. The air blown from the blower fan 103 on the main body case 2 side is introduced into the main body of the diverting duct 40 from the collecting portion 41 of the diverting duct 40. Then, the flow is divided by the first distribution port 42 and the second distribution port 43 provided corresponding to each image forming unit 23, and the development side introduction port 26 and the charging side introduction port of the front cover 25 for each image formation unit 23. 27.

As shown in FIG. 19, an exhaust fan 104 is disposed on the rear (back) side of the main body case 2 as exhaust means for forcibly exhausting the air that has passed through the discharge ports 47 of the image forming units 23. Yes. In the main body case 2 facing the rear side (unit rear end portion 100b) lower part of each image forming unit 23, an individual exhaust duct 108 shown in a cross section in the figure is connected to the unit discharge port 102 shown in FIG. It is arranged. The exhaust duct 108 includes a main body exhaust port 108 a that is connected to the unit discharge port 102. The exhaust duct 108 is integrally formed of resin, and forms an exhaust passage communicating with the unit discharge port 102.
An exhaust chamber 109 that collects air exhausted from the exhaust duct 108 is disposed downstream of each exhaust duct 108. The exhaust fan 104 described above is provided facing the exhaust chamber 109. The main body case 2 of the exhaust fan 104 mounting portion is provided with an exhaust louver portion 107 for discharging air discharged by the exhaust fan 104 to the outside of the main body case 2.

  In FIG. 19, air is sucked through the discharge port 47 and the unit discharge port 102 shown in FIG. 8 of each image forming unit 23 by the negative pressure and suction force generated when the exhaust fan 104 is rotationally driven. The Air sucked from each image forming unit 23 flows through each exhaust duct 108 and is collected in the exhaust chamber 109, and is exhausted from the exhaust louver unit 107 to the outside of the main body case 2 by the exhaust fan 104.

  As described above, according to the present embodiment, the image forming unit 23 that can efficiently cool the drive mechanism on one end side or the other end side of the device without increasing the size of the device by the above configuration and operation. The image forming apparatus 1 can be realized and provided. In addition, there are advantages and effects as described above as appropriate. That is, the front cover 25 and the rear cover 45 can perform a cooling action peculiar to the present invention as well as the function of covering the drive mechanism and have the above-described functions.

  Although the present invention has been described with respect to specific embodiments and the like, the technical contents disclosed by the present invention are not limited to those exemplified in the above-described embodiments or examples. That is, it may be configured by appropriately combining them, and it will be apparent to those skilled in the art that various embodiments, modifications, and examples can be configured within the scope of the present invention according to the necessity and application. It is.

  In the above-described embodiment, the image forming apparatus 1 including the blower fan 103 as the blower unit has been described. However, the present invention is not limited to this. For example, this means that the exhaust fan is removed by setting the exhaust fan on the exhaust side to be powerful. That is, “any one of the cover members includes at least one first introduction port that introduces air from the apparatus main body and guides it into the detachable unit”. Good.

  Although the image forming unit 23 as a process cartridge has been described in the above embodiment, the present invention is not limited to this. That is, for example, a developing unit in which only the developing device 10 as the developing unit is integrally formed in the unit frame and can be attached to and detached from the apparatus main body of the image forming apparatus may be used. At this time, the charging side introduction port may be removed from the front cover, and only the development side introduction port as the first introduction port may be provided. In addition, the image forming apparatus is a detachable unit in which only the developing device 10 as the developing means and the charging roller 9 as the charging means are integrally formed in the unit frame so as to be detachable from the apparatus main body of the image forming apparatus. May be.

DESCRIPTION OF SYMBOLS 1 Image forming apparatus 2 Main body frame (an example of an apparatus main body)
DESCRIPTION OF SYMBOLS 3 Image formation part 4 Optical writing device 5 Paper feed cassette 8 Photosensitive body (an example of an image carrier)
9 Charging roller (example of charging means / charging device)
10 Developing device (an example of developing means)
11 Photoconductor cleaning device (an example of cleaning means)
23 Image forming unit (detachable unit, example of process cartridge)
25 Front cover (an example of one cover member)
26 Development side inlet (an example of a first inlet)
27 Charging side inlet (example of first inlet)
29 Screw (first fastening member)
30 Development-side air flow path 31 Charging-side air flow path 32 Development duct (an example of a duct member)
35 Developing roller (example of developer carrier, rotating body)
35a Developing roller shaft (an example of a developer carrier shaft)
36 1st stirring conveyance screw (an example of a rotary body)
36a Shaft of the first stirring and conveying screw (an example of the shaft of the rotating body)
37 Second stirring and conveying screw (an example of a rotating body)
37a Shaft of second stirring and conveying screw (an example of a shaft of a rotating body)
40 Shunt duct 45 Rear cover (an example of the other cover member)
46 Post-development side inlet (example of second inlet)
47 Discharge port 51 Copper plate (an example of a developing bias transmission member)
52 unit drive mechanism (an example of first and second unit drive mechanisms)
53 Male joint (an example of a first unit drive mechanism)
100 Unit body 100a Unit front end (one end side of the detachable unit)
100b Unit rear end (the other end of the detachable unit)
102 Unit discharge port 103 Blower fan (an example of a blower)
104 Exhaust fan (an example of exhaust means)
105 Main body rear plate 108 Exhaust duct 110 Development drive transmission mechanism (an example of a main body drive mechanism)
120 First drive transmission mechanism M1 Photoconductor drive motor M2 Development drive motor X Front-rear direction (an example of an attachment / detachment direction)
Y Width direction Z Vertical direction

JP 2007-219398 A JP 2012-003059 A

Claims (11)

An detachable unit that is detachable in a predetermined detaching direction with respect to the apparatus main body of the image forming apparatus, and includes at least a drive mechanism as a heat generating portion to be cooled;
The detachable unit has a cover member that covers the drive mechanism of the detachable unit on one end side and the other end side in the detachment direction,
Any one of the cover members includes at least one first introduction port that introduces air from the apparatus main body and guides the air into the detachable unit,
The other cover member among the cover members includes a second inlet for introducing air guided into the detachable unit, and exhausts air introduced from the second inlet to the apparatus main body side. A detachable unit comprising a discharge port.   The detachable unit according to claim 1, further comprising a duct member provided in the detachable unit and forming an air flow path between the cover members. Between each of the cover members and the detachable unit, the shaft of the rotating body is exposed and provided,
The attachment / detachment unit according to claim 1 or 2, wherein an air flow path is formed so that air hits the shaft. The drive mechanism is configured such that the one end side of the detachable unit rotates integrally with a shaft and a gear, and the other end side of the detachable unit rotates while the gear is in sliding contact with the shaft.
The detachable unit according to any one of claims 1 to 3, wherein the one cover member including the first introduction port covers a driving mechanism on the one end side of the detachable unit.   The detachable unit according to any one of claims 1 to 4, wherein the one and the other cover members are detachable from the detachable unit via a first fastening member. The one end side of the detachable unit is detachable from the apparatus main body via a second fastening member,
The fastening position of the second fastening member to the apparatus main body on the one end side of the detachable unit is different from the fastening position of the first fastening member to the detachable unit of the one cover member, and the detachable unit When the one end side of the first cover member is fastened to the apparatus body via a second fastening member and the one cover member is fastened to the detachable unit via the first fastening member, the second cover member is The attachment / detachment unit according to claim 5, wherein the fastening member is hidden. In a process cartridge that is detachable from an apparatus main body of an image forming apparatus and integrally includes an image carrier and at least one unit selected from a charging unit, a developing unit, and a cleaning unit.
7. The process cartridge according to claim 1, wherein the attachment / detachment unit is a process cartridge integrally including the image carrier, the charging unit, and the developing unit.   One of the first introduction ports of the one cover member is used for cooling the developing unit provided with the drive mechanism, and the other one of the first introduction ports is used for cooling the charging unit. The process cartridge according to claim 7, wherein the process cartridge is used in a process. In the developing unit that is detachable from the apparatus main body of the image forming apparatus and integrally includes the developing means,
7. The developing unit according to claim 1, wherein the detachable unit is the developing unit. An image forming unit for forming an image on a recording medium;
An image forming apparatus comprising the process cartridge according to claim 7 or 8 or the developing unit according to claim 9.   The image forming apparatus according to claim 10, wherein the apparatus main body includes a blowing unit that blows air to the first introduction port of the one cover member.

Images