JP6458670B2 - Image forming apparatus - Google Patents

Description

  The present invention relates to an image forming apparatus.

  Conventionally, for example, the following is known as an image forming apparatus in which a detachable unit is detachably mounted on a mounting portion of a housing (main body).

  A process cartridge (detachable unit) that is attached and detached by being inserted and removed in a horizontal direction with respect to the attachment portion of the apparatus main body, and a side plate in the attachment portion that is on the back side in the attachment (insertion) direction of the process cartridge A pressing member is provided at a position below the abutting portion of the positioning portion provided at the end of the process cartridge to press the end (pressed portion) of the process cartridge in the direction of the abutting portion (upper side) with a spring force. An image forming apparatus is known in which when a process cartridge is inserted, the pressing member is temporarily retracted and then restored, and the end on the back side of the cartridge is pressed against the abutting portion (Patent Document 1).

JP 2008-165189 A

  Even if the detachable unit is inserted into and removed from the mounting portion of the housing along the insertion direction that is inclined upward with respect to the reference horizontal plane, the downstream of the detachable unit in the insertion direction. When the side end portion is fitted into the holding hole of the holding member arranged in the mounting portion of the housing, the surface of the holding hole that contacts the detachable unit does not displace so that it tilts in the direction toward the upstream side in the insertion direction. It is an object of the present invention to provide an image forming apparatus that can be smoothly inserted and extracted as compared with the configuration.

The image forming apparatus of the present invention (A1)
A housing having a mounting portion;
Inserted into and removed from the mounting portion of the housing along the insertion direction that is inclined upward with respect to a reference horizontal plane, and is attached to and removed from the mounting portion. A detachable unit in which a portion is lifted and held in a posture parallel to the horizontal plane;
A holding member having a holding hole that is disposed at an end portion on the downstream side in the insertion direction of the mounting portion of the housing and is held by being fitted with a downstream end portion in the insertion direction of the detachable unit;
A pressing member that is attached to the holding member and has a pressing surface that elastically presses the downstream end of the detachable unit fitted into the holding hole toward the upper surface of the holding hole from below;
With
The pressing member can be displaced with respect to the holding member in a direction approaching and separating from the upper surface portion of the holding hole, and can be displaced so that the pressing surface is inclined in a direction toward the upstream side in the insertion direction. It is what is attached.

In the image forming apparatus of the invention (A2), in the image forming apparatus of the invention A1, the holding member has an accommodation arrangement part in which the pressing member is accommodated and arranged below the holding hole, The pressing member is attached to the holding member in a state where there is a gap with respect to the housing arrangement portion.
In the image forming apparatus of the invention (A3), in the image forming apparatus of the invention A1 or A2, the pressing member has an end portion at least upstream in the insertion direction of the pressing surface along the insertion direction. It is formed in the shape containing the inclined surface which inclines.
The image forming apparatus according to the present invention (A4) is the image forming apparatus according to any one of the inventions A1 to A3, wherein the pressing member is provided with a protrusion, and the protrusion of the pressing member is fitted to the downstream end of the detachable unit. A matching depression is provided, or a depression is provided in the pressing member, and a protrusion that fits into the depression of the pressing member is provided at the downstream end of the detachable unit.
In the image forming apparatus of the invention (A5), in the image forming apparatus of the invention A3, a protrusion is provided on the pressing surface of the pressing member, and a recess in which the protrusion of the pressing member fits in an end of the detachable unit. The protrusion on the pressing surface of the pressing member has an inclined surface in which the upstream portion in the insertion direction is continuous with the inclined surface of the pressing surface.

  According to the image forming apparatuses of the inventions A1 and A2, the detachable unit is inserted into and removed from the mounting portion of the housing along the insertion direction inclined upward with respect to the reference horizontal plane. In addition, when the downstream end portion in the insertion direction of the attachment / detachment unit is fitted into the holding hole of the holding member arranged in the mounting portion of the housing, the surface of the holding hole that contacts the attachment / detachment unit is the upstream in the insertion direction. It is possible to smoothly insert and extract as compared with a configuration that does not displace so as to incline in the direction toward the side.

In the image forming apparatus according to the invention A3, the effect of the invention A1 is further improved as compared with the case where the upstream end of the pressing surface of the pressing member is not formed in a shape including an inclined surface that is inclined along the insertion direction. Can be easily obtained.
In the image forming apparatus according to the invention A4, the downstream end of the detachable unit protrudes from the holding hole of the holding member as compared with the case where the protrusion and the depression are not distributed and provided at the downstream end of the pressing member and the detachable unit. The possibility that the detachable unit is pulled out from the mounting portion can be easily reduced.
In the image forming apparatus according to the invention A5, the downstream end of the detachable unit can be more smoothly fitted into the holding hole of the holding member than when the inclined surface is not formed on the protrusion of the pressing surface of the pressing member. .

FIG. 2 is a perspective view illustrating an appearance (an appearance with an exterior cover opened) of the image forming apparatus according to the first embodiment. FIG. 2 is a schematic diagram illustrating an internal configuration of the image forming apparatus in FIG. 1. FIG. 2 is a perspective explanatory view showing an attachment / detachment unit attached to / detached from the image forming apparatus in FIG. 1 and an attached state thereof. It is a perspective view which shows the state when the detachable unit in FIG. 3 is seen from the direction of the near side edge part at the time of the mounting | wearing. It is a perspective view which shows the state when the attachment / detachment unit in FIG. 4 is seen from the direction of the back side edge part at the time of the attachment. FIG. 5 is a perspective view showing the detachable unit in FIG. 4 in a state when looking up from the bottom side. It is a rear view which shows the state when the attachment / detachment unit in FIG. 4 is seen from the direction of the back side edge part at the time of the attachment. It is a schematic sectional drawing in alignment with the QQ line of the attachment / detachment unit in FIG. It is a perspective view shown in the state when the detachable unit in FIG. 5 is looked up from the diagonally lower side. (A) is a perspective view showing the operating lever of the detachable unit when viewed from the front side, (b) is a perspective view showing the operating lever of (a) when viewed from the back side, (c) is sectional drawing which follows the QQ line of the operation lever of (b). FIG. 5 is an explanatory perspective view illustrating a configuration of a bottom surface side at a front end portion when the detachable unit is mounted in FIG. 4. It is perspective explanatory drawing which shows the to-be-fitted part as an incorrect attachment prevention means of four attachment / detachment units. It is a perspective view which shows the exposure apparatus with which the image forming apparatus in FIG. 1 is provided. (A) is sectional drawing which follows the QQ line | wire of the attachment / detachment unit in FIG. 8 (It is changing into the state which fell down the operation lever, and the holding part of the mounting part is also written together), (b) is a figure. It is sectional drawing which follows the QQ line of 13 exposure apparatuses (In addition, the mounting base of the mounting part is written together.). FIG. 2 is a perspective explanatory view of a main part showing one state of a process of attaching / detaching a mounting part (including an intermediate transfer device) and a mounting / detaching unit of the housing of the image forming apparatus in FIG. 1. It is sectional explanatory drawing which shows the state of the stage which inserted the attachment / detachment unit in the mounting part of the housing | casing in FIG. It is explanatory drawing which shows the state of the mounting part and attachment / detachment unit of a housing | casing in FIG. 16 in the state when it sees from the near side of an insertion direction. FIG. 16 is an explanatory cross-sectional view showing a state where the detachable unit is positioned in the mounting portion of the housing in FIG. 15. It is explanatory drawing which shows the state of the mounting part of a housing | casing in FIG. 18, and the attachment / detachment unit in the state when it sees from the near side of an insertion direction. It is a side view which shows the mounting part of the housing | casing in FIG. 15 in the state when it sees from the insertion direction near side of an attachment / detachment unit. FIG. 21 is a perspective explanatory view showing the mounting portion of the housing in FIG. 20 in a state in which an intermediate transfer device, an exposure device, a back support plate, and the like are removed. It is plane explanatory drawing which shows the mounting part of the housing | casing in FIG. 21 in the state which attached the exposure apparatus. It is the front view and right-and-left side view which show the holding | maintenance part in a mounting part. It is a disassembled perspective view which shows each structure of the holding | maintenance part in a mounting part. It is explanatory drawing which shows the structure in the axial part of a detachable unit as a cross-sectional part while showing the structure of a holding | maintenance part as a cross-sectional part which follows the QQ line in FIG. FIG. 22 is a perspective explanatory view showing a front side end portion of the mounting portion of the housing in FIG. 21. It is perspective explanatory drawing which expands and shows a part of front side edge part of the mounting part in FIG. It is explanatory drawing which shows the structure regarding the guidance etc. of the mounting part of the housing | casing in FIG. 20, and the attachment or detachment unit in FIG. The upper part of the figure shows the state of the bottom side of the correctly inserted and detached unit and the insertion position, and the middle part of the figure shows one of the divided parts of the mounting part as seen from above, The lower part of the figure shows the state and the insertion position on the bottom side of the detachable unit that has been erroneously inserted. It is explanatory drawing which shows the structure regarding the guidance etc. of the mounting part of the housing | casing in FIG. 20, and the attachment or detachment unit in FIG. The upper part of the figure shows the state of the upper surface side and the insertion position of the detachable unit correctly inserted, and the middle part of the figure shows one of the divided parts of the mounting part as seen from above, The lower part of the figure shows the state and the insertion position on the upper surface side of the detachable unit that is erroneously inserted. It is perspective explanatory drawing which shows the state and positional relationship of the back side edge part of an attachment / detachment unit when attaching / detaching an attachment / detachment unit to an attachment part, and the insertion side near-end part of an attachment part. The perspective view which shows the state and positional relationship of the back side edge part of the attachment / detachment unit when attaching / detaching the attachment / detachment unit to / from the attachment part and the insertion end side end part of the attachment part when viewed from an angle different from FIG. It is explanatory drawing. It is partial cross-sectional explanatory drawing which shows the state of the attachment / detachment unit and attachment part at the time of attachment / detachment in the state when it sees from the downstream of an insertion direction. It is a partial cross-section explanatory drawing which shows the state of the attachment / detachment unit and attachment part at the time of attachment / detachment in the state when it sees from the upstream of an insertion direction. It is a perspective explanatory view showing the state of the attachment / detachment unit and the attachment part at the time of attachment / detachment when looking down from the upper side on the upstream side in the insertion direction. It is perspective explanatory drawing of the principal part which shows the state of the middle stage when inserting and extracting a detachable unit with respect to a mounting part. FIG. 36 is a cross-sectional explanatory view taken along the line QQ of the detachable unit and the mounting portion (including a part of the intermediate transfer device) in FIG. It is perspective explanatory drawing which shows each positional relationship with respect to the mounting part of the attachment / detachment unit inserted correctly, and the attachment / detachment unit inserted incorrectly. FIG. 38 is an explanatory plan view showing the positional relationship between the correctly inserted / detached unit and the incorrectly inserted / detached unit in FIG. 37 relative to the mounting portion. It is a perspective explanatory view showing a state when the detachable unit is correctly inserted into the mounting portion. It is side surface explanatory drawing which notches a part of attachment / detachment unit and shows the state when an attachment / detachment unit is correctly inserted in the attachment part. FIG. 6 is a cross-sectional explanatory view of a main part showing a state of a shaft portion of the photosensitive drum and a pressing member in a holding hole of the holding portion when the detachable unit is inserted (extracted) from the mounting portion. It is a perspective explanatory view showing a state when the detachable unit is positioned (attached) to the attachment part. FIG. 43 is an explanatory sectional view taken along the line QQ of the detachable unit and the mounting portion in FIG. 42. It is side surface explanatory drawing which notches a part of attachment / detachment unit and shows the state when an attachment / detachment unit is positioned by the attachment part. It is sectional explanatory drawing which shows the state (movement of a middle step) when attaching / detaching an attachment / detachment unit to an attachment part, and the state of exposure apparatus. FIG. 46 is a cross-sectional explanatory view showing the movement of attaching / detaching the detachable unit to / from the mounting portion (movement at a middle stage slightly shifted from the timing of FIG. 45) and the state of the exposure apparatus. FIG. 47 is an explanatory cross-sectional view showing a state when the detachable unit in FIG. 46 is positioned and a state of the exposure apparatus. 48 is a cross-sectional view taken along the line QQ of the detachable unit and the exposure apparatus excluding the intermediate transfer device and the mounting portion in FIG. 47. FIG. FIG. 6 is a cross-sectional explanatory view of a main part showing a state of a shaft portion of the photosensitive drum and a pressing member in a holding hole of the holding portion when the detachable unit is positioned on the mounting portion.

  Hereinafter, modes for carrying out the present invention (hereinafter referred to as “embodiments”) will be described with reference to the drawings.

[Embodiment 1]
1 to 6 show an image forming apparatus and the like according to the first embodiment.
FIG. 1 shows the appearance of the image forming apparatus (the appearance with the exterior cover 14 opened), FIG. 2 shows the internal configuration of the image forming apparatus, and FIG. 3 shows the developer recovery container in the image forming apparatus. FIG. 4 to FIG. 6 show a detachable unit that is detachably attached to the image forming apparatus. In addition, the arrows indicated by reference signs X, Y, and Z in each drawing such as FIG. 1 are orthogonal coordinate axes (directions) indicating the respective directions of the width, height, and depth of the three-dimensional space assumed in each drawing.

<Overall Configuration of Image Forming Apparatus>
The image forming apparatus 1 according to Embodiment 1 forms an image composed of a developer on a recording sheet 9 as an example of a recording medium. For example, an image input from an external device such as an information terminal The printer is configured to receive information and form an image.

  The image forming apparatus 1 has a casing 10 having a box-like appearance as a whole, and the internal space of the casing 10 is configured with toner as a developer as shown in FIG. An image forming apparatus 2 for forming a toner image, and a toner image formed by the image forming apparatus 2 after being held by primary transfer and then transported to a secondary transfer position where the toner image is finally secondary-transferred to the recording paper 9 The intermediate transfer device 30, the paper feeding device 40 that receives and sends the recording paper 9 to be supplied to the secondary transfer position of the intermediate transfer device 30, and the toner image secondarily transferred by the intermediate transfer device 30 are recorded on the recording paper 9. A fixing device 45 and the like for fixing are disposed. A discharge storage portion 12 for discharging and storing the recording paper 9 on which the image is formed is formed on the upper surface portion 10 a of the housing 10. A one-dot chain line shown in FIG. 2 is a main conveyance path of the recording paper 9 inside the housing 10.

  The image forming apparatus 2 includes four image forming apparatuses 2Y, 2M, and 4D that individually form developer (toner) images of four colors of yellow (Y), magenta (M), cyan (C), and black (K), respectively. 2C and 2K are used. Further, these image forming apparatuses 2 (Y, M, C, K) are arranged in a state (inclined state) in which the position gradually increases in the order of black, cyan, magenta, and yellow in the internal space of the housing 10. ing.

  Each of the four image forming apparatuses 2 (Y, M, C, and K) is a photosensitive drum 21 that is rotationally driven in a direction indicated by an arrow A (a clockwise direction in FIG. 2), and an outer peripheral surface of the photosensitive drum 21. A charging device 22 such as a roll for charging the image forming surface to a required potential, and the image forming surface after charging of each photosensitive drum 21 are irradiated with light separated into each color component based on the required image information. The exposure device 23 for forming the electrostatic latent images of the components, and the electrostatic latent images on the photosensitive drums 21 are visualized as the toner images of the respective colors by supplying and developing the corresponding color component toners. Developing device 24 (Y, M, C, K) and the toner image remaining on the outer peripheral surface after the toner image on each photosensitive drum 21 is primarily transferred to intermediate transfer device 30 (intermediate transfer belt 31 thereof). Drum to remove unnecessary materials and clean It is composed of a sweep apparatus 26 or the like. In FIG. 2, the reference numerals 22 to 24 and 26 of the respective devices are all given as representatives only for the image forming device 2K.

  In each image forming device 2 (Y, M, C, K), when a request (information) for image formation is received, after the charging device 22 charges the outer peripheral surface of the photosensitive drum 21 that starts rotating to a required potential, An electrostatic latent image of each color component is formed by irradiating light corresponding to the image signal of each color component from the exposure device 23 onto the outer peripheral surface of the charged photosensitive drum 21. Subsequently, the developing device 24 (Y, M, C, K) corresponding to the electrostatic latent image of each color component formed on the outer peripheral surface of each photosensitive drum 21 has the four colors (Y, M, C, K). The four color toner images are formed on the respective photosensitive drums 21 by developing with any color toner.

  The intermediate transfer device 30 corresponds to the fact that the image forming devices 2 (Y, M, C, K) are arranged in an inclined state at a position above the gravity direction of the image forming devices 2 (Y, M, C, K). It is arranged in a slightly inclined state.

The intermediate transfer device 30 is an endless intermediate transfer capable of transporting a toner image formed on the photosensitive drum 21 of the image forming device 2 (Y, M, C, K) to a secondary transfer position after holding the toner image by primary transfer. A plurality of support rolls 32a to 32a that support the belt 31 and the intermediate transfer belt 31 so as to sequentially pass through the primary transfer positions of the image forming device 2 (Y, M, C, K) and rotate in the direction indicated by the arrow B. 32e and each toner image disposed on the inner side of the intermediate transfer belt 31 and formed on the photosensitive drum 21 of each image forming device 2 (Y, M, C, K) are primarily transferred to the outer peripheral surface of the intermediate transfer belt 31. A primary transfer device 34 that generates a primary transfer action, and a secondary transfer device that is disposed outside the intermediate transfer belt 31 and that secondarily transfers the toner image primarily transferred to the intermediate transfer belt 31 onto the recording paper 9. B that generates transcription A secondary transfer device 35, such as Le form, and a like belt cleaning device 36 that unwanted matter is removed cleaned such as toner remaining on the outer peripheral surface of the intermediate transfer belt 31 after the secondary transfer.
Among these, the support roll 32a is a drive roll and a secondary transfer backup roll, the support roll 32b is a cleaning backup roll, the support roll 32c is a tension applying roll, and the support rolls 32d and 32e are primary transfer surfaces of the intermediate transfer belt 31. Each surface forming roll is formed.

The paper feeding device 40 is disposed at a position on the lower side in the gravity direction of the image forming device 2 (Y, M, C, K).
The sheet feeding device 40 is detachably attached to the housing 10 and includes one or a plurality of sheet containers 41 that accommodate recording sheets 9 having a desired size and type on the stacking plate 42. And a feeding device 43 that feeds the recording paper 9 from the paper container 41 one by one. In the paper feeding device 40, when an image is formed, the required recording paper 9 is sent out one by one from the paper container 41 by the sending device 43. The recording paper 9 sent out from the paper feeding device 40 travels along a transport path indicated by a one-dot chain line, and the intermediate transfer device 30 is matched with the secondary transfer time by a transport time adjusting roll pair 44 arranged on the transport path. To the secondary transfer position (the portion where the secondary transfer device 35 is in contact with the intermediate transfer belt 31).

  In the intermediate transfer device 30, when an image is formed, each color toner image formed by the image forming device 2 (Y, M, C, K) is subjected to the primary transfer action of the primary transfer device 34, and the intermediate transfer belt 31. The primary transfer is sequentially performed while being aligned with the outer peripheral surface. At this time, in the image forming device 2 (Y, M, C, K), the outer peripheral surface after the primary transfer of the photosensitive drum 21 is cleaned by the drum cleaning device 26. Subsequently, the intermediate transfer belt 31 rotates in the direction indicated by the arrow to convey the primary transferred toner image to the secondary transfer position facing the secondary transfer device 35. Thereafter, in the intermediate transfer device 30, the toner image on the intermediate transfer belt 31 is subjected to the secondary transfer action of the secondary transfer device 35 on the recording paper 9 supplied from the paper supply device 40 to the secondary transfer position. Secondary transferred. At this time, in the intermediate transfer device 30, the outer peripheral surface after the secondary transfer of the intermediate transfer belt 31 is cleaned by the belt cleaning device 36.

The fixing device 45 is disposed at a position on the upper side in the gravity direction of the secondary transfer position of the intermediate transfer device 30.
The fixing device 45 is driven to rotate inside a casing of the device in a required direction and is heated by a heating unit, and is heated by a heating unit to maintain a surface temperature at a required temperature. And a pressurizing rotating body 47 such as a roll form or a belt form that contacts and rotates at a required pressure so as to substantially follow the rotation axis direction of the heating rotating body 46.

  At the time of image formation, the fixing device 45 sends the recording paper 9 on which the toner image is secondarily transferred by the intermediate transfer device 30 to the pressure contact portion where the heating rotator 46 and the pressure rotator 47 are in pressure contact with each other. By heating and pressurizing, the toner image is melted and fixed on the recording paper 9. The recording sheet 9 after being fixed is sent out from the fixing device 45 and travels on a transport path indicated by a one-dot chain line, and then is transported to the outside of the casing 10 by a discharge roll pair 48 disposed on the transport path. Is accommodated in the discharge accommodating portion 12.

  Further, in the image forming apparatus 1, all or a part (at least a plurality of colors of toner) of the image forming apparatus 2 (Y, M, C, K) is selected and operated to select four colors (Y, M, It is possible to form a multicolor image configured by combining all or some of the C, K) toner colors. Further, by operating one of the image forming devices 2 (Y, M, C, K), it is possible to form a single color image composed of one color toner such as black.

  Further, in the image forming apparatus 1, the collection target scraped and removed by the drum cleaning devices 26 of the four image forming devices 2 (Y, M, C, and K) and the belt cleaning device 36 of the intermediate transfer device 30. The developer is finally collected and collected in a detachable developer collecting container 6. The developer recovery container 6 is detachably mounted on a container mounting part 10f provided as a structure part recessed in one side surface part 10b of the casing 10 (FIG. 1 and the like), for example, recovered. It is replaced when it becomes full of developer.

<Configuration for detachable unit>
In the image forming apparatus 1, as shown in FIG. 3 to FIG. 9 and the like, a photosensitive drum 21 which is a part of the components constituting the image forming device 2 (Y, M, C, K), a charging device, and the like. 22, the developing device 24 (Y, M, C, K) and the drum cleaning device 26 are supported and integrated by a common support frame 201, and the whole is part of the casing 10 of the image forming apparatus 1. It is configured as a unit structure (detachable units 20Y, 20M, 20C, 20K) that is detachably attached to the mounting portion 13 provided.

  The detachable unit 20 (Y, M, C, K) is in a direction along the axial direction of the rotation axis of the photosensitive drum 21 with respect to the mounting portion 13 of the housing 10 as shown in FIGS. It is configured to be attached and detached by inserting and extracting in the directions indicated by arrows D1 and D2. That is, the detachable unit 20 is inserted by being moved along the insertion direction (insertion direction) indicated by the arrow D1 with respect to the mounting portion 13, and is also along the extraction direction (extraction direction) indicated by the arrow D2. It is designed to be extracted by moving it.

Incidentally, the remaining exposure devices 23 constituting each image forming device 2 (Y, M, C, K) are attached in advance to required portions of the mounting portion 13 (see FIGS. 15, 20, etc.). .
Further, the intermediate transfer device 30 is attached in a state of being positioned in a mounting portion (not shown) formed in a part of the housing 10 as a space for mounting the intermediate transfer device 30. In addition, in the intermediate transfer device 30, the portion excluding the secondary transfer device 35 (transfer unit 300: FIG. 15) is, for example, extracted from the dedicated mounting portion located above the mounting portion 13 of the housing 10. It is pulled out in the same direction as the direction D2 and attached so as to be exposed to the outside of the housing 10.

<Outline of attaching / detaching operation of attaching / detaching unit>
The attachment / detachment of the attachment / detachment unit 20 (Y, M, C, K) with respect to the attachment portion 13 is generally performed as follows. In the image forming apparatus 1, when the attachment / detachment unit 20 is attached / detached, a displacement operation such as separating or approaching the intermediate transfer device 30 with respect to the attachment / detachment unit 20 (the photosensitive drum 21) and a displacement mechanism therefor are performed. It is unnecessary.

First, when mounting, the detachable unit 20 (Y, M, C, K) is inserted into the mounting portion 13 of the housing 10 and housed as shown in FIG.
At this time, as shown in FIG. 16 and the like, the detachable unit 20 is inserted and accommodated in a state where the end on the upstream side in the insertion direction D1 is displaced in a direction away from the intermediate transfer device 30. ing. As a result, the detachable unit 20 moves downward from the intermediate transfer belt 31 (actually, the belt portion supported by the transfer roll of the primary transfer device 34) on the end side where the photosensitive drum 21 is upstream in the insertion direction D1. They are displaced so as to be separated from each other, and the entire unit is maintained in a state where one side is lowered and inclined. At this time, as shown in FIG. 17 and the like, each detachable unit 20 (Y, M, C, K) has an end portion on the upstream side in the insertion direction D1 (an end portion on the side where the side plate 201A exists). The mounting portion 13 is slightly lowered from a position where an image forming operation can be performed.

  Incidentally, in the attachment / detachment unit 20 at this time, the angle (inclination angle) θ1 formed by the outer surface along the axial direction of the photosensitive drum 21 and the intermediate transfer belt 31 (the belt outer peripheral surface 31a) is a required angle (for example, 1 °). (FIGS. 16, 46, etc.). For this reason, the insertion direction D1 of the detachable unit 20 is a direction inclined with respect to the reference horizontal plane so as to have an upward gradient toward the downstream side of the insertion direction D1. In other words, the extraction direction D2 of the detachable unit 20 is inclined so as to have a descending gradient toward the downstream side of the extraction direction. The reference horizontal plane corresponds to, for example, a plane formed by the coordinate axes X and Z in the drawing, and also assumes a horizontal plane assumed in the design, a floor assumed in the place where the image forming apparatus 1 is installed, and the like. Is applicable.

Subsequently, the detachable unit 20 (Y, M, C, K) is positioned at the mounting portion 13 of the housing 10.
At this time, the detachable unit 20 is displaced in a direction (E1) in which the end on the upstream side in the insertion direction D1 approaches the intermediate transfer device 30 by operating an operation lever (50) described later. It becomes a state. Thereby, as shown in FIG. 18 and the like, the detachable unit 20 includes the intermediate transfer belt 31 (actually, the primary transfer) including the end side where the photosensitive drum 21 (outer peripheral surface) is upstream in the insertion direction D1. The belt portion supported by the roll of the apparatus 34 can be kept in contact with the entire area.

  As described above, the detachable unit 20 (Y, M, C, K) is positioned in the mounting portion 13 and is officially mounted (a state in which an image forming operation is possible). At this time, each detachable unit 20 (Y, M, C, K) has an end portion (201A) on the upstream side in the insertion direction D1 as shown in FIG. It will be displaced so that it can be lifted to a possible position.

On the other hand, when detaching, the detachable unit 20 (Y, M, C, K) is extracted from the mounting portion 13 of the housing 10.
At this time, prior to the extraction, first, an operation lever (50) described later is operated to displace the end portion on the upstream side in the insertion direction D1 of the detachable unit 20 in a direction away from the intermediate transfer device 30. Set to the state (positioning released). As a result, as described above, the detachable unit 20 is shifted so as to be spaced downward from the intermediate transfer belt 31 on the end side where the photosensitive drum 21 is upstream in the insertion direction D1, and is inclined as a whole unit. . At this time, each detachable unit 20 (Y, M, C, K) has an end portion (201 A) on the upstream side in the insertion direction D 1 at the mounting portion 13, as in the state when it is inserted into the mounting portion 13. The state is lowered slightly from the normal position (FIG. 16 and the like).

  Thereafter, the detachable unit 20 is pulled out by being moved along the pulling direction D2 from the mounting portion 13 in the inclined state. Thereby, the detachable unit 20 is removed to the outside of the mounting portion 13 in the housing 10 (FIG. 3).

<Detailed configuration of removable unit>
The detachable units 20 (Y, M, C, K) all have a photosensitive drum 21, a charging device 22, a developing device 24 (Y, M, C, K) and a drum as shown in FIGS. This is a structure in which the cleaning device 26 is supported by the support frame 201 and integrated.

Main components constituting the detachable unit Of these, the support frame 201 is mainly composed of two side plates 201A and 201B, and is composed of a connecting member (not shown) that connects and holds the side plates 201A and 201B. Yes.

  As the photosensitive drum 21, for example, a drum in which a photosensitive layer made of an organic conductive material or the like is formed on the outer peripheral surface of a cylindrical conductive substrate to be grounded is used. At both ends in the longitudinal direction corresponding to the axial direction of the photosensitive drum 21, disk-shaped flange portions 212 and 213 constituting a part of the conductive substrate are provided. Further, the photosensitive drum 21 is rotatably attached to the side plates 201A and 201B of the support frame via shaft portions protruding from both end portions thereof. Further, the photosensitive drum 21 is transmitted from the mounting portion 13 side to the inner side of the shaft portion 214 provided so as to protrude outward from the side plate 201B which becomes the distal end side (the back side when mounting) of the detachable unit 20 in the insertion direction D1. A transmitted gear 215 (FIG. 9) that receives the rotational power is disposed. As the transmitted gear 215, for example, a female gear having gear teeth formed on an inner wall surface of a cylinder is used.

  As the charging device 22, a contact-type charging device is used in which a charging roll 221 that contacts and rotates with the image forming surface of the photosensitive drum 21 is contacted. Both ends of the charging roll 221 are rotatably attached to the side plates 201A and 201B of the support frame, and are in contact with the outer peripheral surface of the photosensitive drum 21 to be driven to rotate. The charging roll 221 is supplied with a charging voltage sent from the mounting portion 13 side. Furthermore, the outer peripheral surface of the charging roll 221 is cleaned by a cleaning brush roll 222 that rotates in contact with the outer peripheral surface of the roll (FIG. 8).

  As the developing device 24 (Y, M, C, K), for example, a two-component developing device that performs development using a two-component developer containing toner and carrier is applied. Each of the developing devices 24 includes a developing opening facing along the axial direction of the photosensitive drum 21, an accommodating portion including a partition space for accommodating and circulating the developer, and replenishment development supplied to the accommodating portion. It has a housing 240 in which a replenishment receiving portion 240c for receiving the agent is formed. The housing 240 includes therein a developing roll 241, a screw auger 242 that is an example of an agitating and conveying member that stirs and conveys the developer stored in the storage unit toward the developing roll 241, and the developing roll 241. A round bar-shaped layer thickness regulating member 243 that regulates the thickness of the developer layer that is supplied to and held in the cylinder is disposed.

Among these, the developing roll 241 includes a cylindrical sleeve 241a that is arranged to rotate in the direction indicated by the arrow C, and a magnet roll 241b that is arranged inside the sleeve 241a. Further, the developing roll 241 is provided with disc-shaped tracking rolls 244 that are in contact with the flange portions 212 and 213 of the photosensitive drum 21 and hold a required gap with the image forming surface of the photosensitive drum 21 at both ends thereof. Yes.
Further, as shown in FIGS. 5 and 7, the developing roll 241 (sleeve 241 a thereof) serves as a shaft coupling for receiving rotational power at the end portion on the downstream side in the insertion direction D <b> 1 of the detachable unit 20. The driven-side coupling 245 is attached so as to protrude from the end of the housing 240.

Further, the developing device 24 (Y, M, C, K) includes a protruding end portion 246 that extends upward from the developing opening of the housing 240 as shown in FIGS. 4, 5, 8, and the like. A swing support portion (swing shaft portion) 247 formed at both ends of the detachable unit 20 is attached by being rotatably fitted in the swing bearing holes 202 formed in the side plates 201A and 201B of the support frame of the detachable unit 20. It has been. With this attachment structure, the developing device 24 is supported in the detachable unit 20 so as to be swingable (swaying) in the directions indicated by the arrows H1 and H2 around the swing support portion 247.
Further, the developing device 24 (Y, M, C, K) is pushed in a direction indicated by an arrow H1 by a coil spring 248 attached between a part of the housing 240 and the side plates 201A, 201B of the support frame. It has become. As a result, the developing device 24 assists the tracking roll 244 of the developing roll 241 in contact with the flange portions 212 and 213 of the photosensitive drum 21.

  The drum cleaning device 26 is scraped off by a cleaning member 261 such as an elastic plate that contacts the outer peripheral surface of the photosensitive drum 21 and scrapes unnecessary materials such as residual toner, and the cleaning member 261 inside the device casing. A rotary conveying member 262 such as a screw auger that feeds residual toner through the inside of the conveying pipe 263 to the developer recovery container 6 is provided. The drum cleaning device 26 is attached in a state in which both end portions thereof are fixed to the side plates 201A and 201B (or connection members thereof) of the support frame.

◎ Operating lever in the detachable unit In addition, the detachable unit 20 (Y, M, C, K) is inserted in the insertion direction D1 when mounted in the mounting portion 13 and housed as shown in FIGS. An operation lever 50 is provided for performing an operation of displacing the downstream end in the direction approaching and separating from the intermediate transfer device 30 (directions indicated by arrows E1 and E2). The approaching and separating directions E1 and E2 at this time are different directions from the insertion direction D1 and the extraction direction D2, which are constant directions of the detachable unit 20. As the approaching and separating directions E1, E2, for example, a gravitational direction substantially orthogonal to the insertion direction D1 is set.

  The operation lever 50 is a member that performs an operation of displacing the downstream end of the detachable unit 20 in the directions E1 and E2 that approach and separate from the intermediate transfer device 30. As a result, the operation lever 50 performs an operation of finally bringing the photosensitive drum 21 in the detachable unit 20 into contact with or away from the intermediate transfer belt 31 (part supported by the primary transfer device 34). Can be done.

  As shown in FIG. 10 and the like, the operation lever 50 includes a plate-shaped main body 51 formed in a required shape, and a swing shaft 210 inserted on the lower side of the main body 51 so that the main body 51 is moved. A bearing portion 52 that is rotatably supported in directions indicated by arrows J1 and J2, and a direction (arrows K1 and K2) in which the bearing portion 52 approaches and separates from the bearing portion 52 at a portion below the bearing portion 52 of the main body portion 51. A displacement bottom 53 that is freely displaceable, and a coil spring 67 that elastically presses the displacement bottom 53 between the displacement bottom 53 and the bearing 52 in a direction K2 that separates from the bearing 52 are provided. The rocking shaft portion 210 serves as a rocking fulcrum disposed under the support frame side plate 201 </ b> A of the detachable unit 20.

The operation lever 50 is indicated by arrows J1 and J2 centering on the swinging shaft portion 210 disposed at the lower portion of the side plate 201A of the detachable unit 20, as shown in FIG. 14, FIG. 16, FIG. It is operated by swinging (moving) in the direction.
Specifically, when the operation lever 50 displaces the downstream end of the attachment / detachment unit 20 in the direction E1 approaching the intermediate transfer device 30, the operation lever 50 is operated to swing in the raising direction indicated by the arrow J1. On the other hand, when the downstream end of the detachable unit 20 is displaced in the direction E2 away from the intermediate transfer device 30, the detachable unit 20 is operated so as to swing in the tilting direction indicated by the arrow J2.

The operation lever 50 is a displacement bottom portion that becomes a lower end portion when the operation lever 50 swings in a direction J1 that causes the downstream end portion of the detachable unit 20 to be displaced in a direction E1 approaching the intermediate transfer device 30. 53 is configured to be held in contact with a part of the mounting portion 13 (fixed surface portion 135).
The operating lever 50 is elastically pressed by a coil spring (not shown) so as to be swung in the direction J2 in which it is tilted. The coil spring (not shown) is attached in a state where one end of the coil spring is brought into contact with the side plate 201A and the other end is brought into contact with the main body 51 after the coil portion is attached to the bearing portion 52.

The displacement bottom 53 has a box-like shape in which a space for accommodating the lower part of the main body 51 and the coil spring 67 is formed on the inside thereof, as shown in FIG. The protrusion 51c of the main body 51 is fitted in the guide groove 55, and is attached so as to be guided and moved in the directions indicated by the arrows K1 and K2.
Further, the displacement bottom 53 is moved in the direction K2 away from the shaft portion 52 when, for example, the upper end 55a of the guide groove 55 formed on the side surface of the displacement bottom portion 53 comes into contact with the projection 51 provided in the lower portion of the main body 51. Being regulated. The displacement bottom 53 is restricted from moving in the direction K <b> 1 approaching the shaft 52, for example, when a part of the upper end (notch) 53 b contacts the stop protrusion 51 d provided on the main body 51. It has become so.

  Further, the displacement bottom 53 has a coil spring 67 arranged in a state in which the upper end is brought into contact with the bearing portion 52 while the lower end is brought into contact with the inner bottom surface. As a result, the displacement bottom 53 is kept elastically pressed in the direction K2 away from the bearing 52 by the spring force F1 of the coil spring 67. The displacement bottom 53 comes into contact with a part of the mounting portion 13 (the fixed surface portion 135) when the detachable unit 20 is mounted on the mounting portion 13 and is operated by swinging in the direction J1 in which the operation lever 50 is raised. (FIG. 18, FIG. 43, etc.). At this time, the displacement bottom 53 is pressed by the spring force F 1 of the coil spring 67, and a reaction force against the spring force F 1 is generated in the bearing portion 52, and the reaction force (F 1) is transmitted through the swing shaft portion 210. 20 is exerted as a force that presses the downstream end 20 (side plate 201A) in the direction E1 approaching the intermediate transfer device 30 (FIGS. 18 and 43).

◎ Space for Exposure Device In addition, the detachable unit 20 (Y, M, C, K) includes an exposure device 23 between the developing device 24 and the drum cleaning device 26 as shown in FIGS. An arrangement space 203 for accommodating and arranging is provided.
The arrangement space portion 203 is an elongated space that extends substantially along the insertion direction D1 and the extraction direction D2 of the detachable unit 20, and is an end portion that becomes the downstream side (back side) of the insertion direction D1 of the detachable unit 20. The side is open, and the end side that is the upstream side (front side) in the insertion direction D1 of the detachable unit 20 is a closed space.

  In addition, the detachable unit 20 is guided to be accommodated by guiding one end portion (guided portion 27), which will be described later, of the exposure apparatus 23 to the upstream end in the insertion direction D1 when the detachable unit 20 is inserted. 204 is provided (FIGS. 7 to 11, FIG. 14, etc.).

◎ Configuration for positioning of detachable unit In addition, the detachable unit 20 (Y, M, C, K) is arranged on the downstream side (back side) in the insertion direction D1, as shown in FIGS. A protrusion 205 for fixing is provided on the side plate 201B of the support frame located.
The protruding portion 205 is provided at a portion of the side plate 201B that is below the drum cleaning device 26 so as to protrude toward the downstream side in the insertion direction D1 of the detachable unit 20. The protrusion 205 is fitted into a mounting hole (17) formed in a holding part (15) described later in the mounting part 13. Thereby, the protrusion part 205 is attached in the state which fixed the lower part of the side plate 201B of the support frame to the holding | maintenance part (15).

Further, the detachable unit 20 (Y, M, C, K) is attached to the side plate 201A located on the upstream side (front side) in the insertion direction D1, as shown in FIGS. A contact surface portion 206 is provided for positioning when the end portion on the upstream side of the unit is inserted and accommodated in the mounting portion 13.
The positioning contact surface portion 206 is formed of an arc having substantially the same curvature as the curvature of the outer peripheral surface of the photosensitive drum 21 at a position that is substantially the same height as the arc-shaped outer peripheral surface of the photosensitive drum 21 at the upper end portion of the side plate 201A. It is provided as a curved part. The contact surface portion 206 is fitted in contact with a positioning receiving shape portion (302) formed on a support plate (301) (described later) of the intermediate transfer device 30 disposed in the mounting portion 13 during the positioning. It is kept in the state. As a result, the contact surface portion 206 causes the photosensitive drum 21 in the detachable unit 20 (strictly, the end portion on the upstream side in the insertion direction D1) to be inserted and accommodated in the mounting portion 13 to the intermediate transfer belt 31 in the intermediate transfer device 30. It is positioned with respect to the contact position.

Constitution regarding guide when attaching / detaching the detachable unit As shown in FIG. 9 and the like, the detachable unit 20 (Y, M, C, K) is arranged by housing the exposure device 23 in the housing 240 of the developing device 24. A first guided portion 71 that is guided by being fitted with a first guide portion (75) to be described later in the exposure apparatus 23 is provided at a portion facing the arrangement space portion 203.
The first guided portion 71 protrudes toward the arrangement space portion 203 at the end portion on the downstream side in the insertion direction D1 of the housing 240 of the developing device 24 and faces away from the vertical direction. Two opposing protrusions 71a and 71b are provided, and a guided space 71c into which the first guide part (75) is inserted is provided between the two opposing protrusions 71a and 71b. ing. The first guided portion 71 is guided only when the first guiding portion (75) is fitted in the guided space 71c. Therefore, the first guided portion 71 is used as a temporary guided portion of the temporary guiding portion.

The detachable unit 20 (Y, M, C, K) is attached to the lower end of the casing 260 and the lower end of the connecting member of the support frame 201 in the drum cleaning device 26 as shown in FIGS. A second guided portion 73 is provided that is fitted and guided and supported by a second guide portion (77) described later in the mounting portion 13.
The second guided portion 73 projects toward the opposite side to the arrangement space portion 203 of the exposure device 23 at the lower end portion of the casing 260 or the connecting member of the drum cleaning device 26 and along the insertion direction D1. It is formed as a plate-like portion having a required length (guided length) Gm2 (FIG. 28). When the second guided portion 73 is fitted into the second guide portion (77) of the mounting portion 13, the insertion direction D1 and the extraction direction of the detachable unit 20 cooperate with the guide portion (77). The movement along D <b> 2 is guided and the detachable unit 20 is supported by the mounting portion 13.

Further, the detachable unit 20 (Y, M, C, K) is positioned by being fitted to a later-described fitting portion (78) in the mounting portion 13 at the lower portion of the side plate 201A as shown in FIGS. A fixed protrusion 74 is provided.
The protruding portion 74 is formed on the inner surface side of the lower portion of the side plate 201A as a portion protruding in a direction facing a lower end portion of the housing 240 of the developing device 24 or a fitting protrusion (85) of an erroneous mounting preventing means described later. Yes. The protrusion 74 is held by being inserted into a fitting portion (78), which will be described later, in the mounting portion 13 and moved when the detachable unit 20 is aligned after being inserted into the mounting portion 13. Thus, the protrusion 74 holds the lower portion of the side plate 201A of the detachable unit 20 on the mounting portion 13 and positions the detachable unit 20 in the insertion direction D1 or the like.

◎ Structure relating to means for preventing erroneous mounting of the detachable unit The detachable unit 20 (Y, M, C, K), as shown in FIG. 6, FIG. 7, FIG. A fitting projection 85 is provided as an erroneous mounting preventing means that is fitted when the fitting groove (81) as the preventing means is fitted.

  One fitting projection 85 is provided in each section screen portion 249 that is partitioned into a common area and a planar shape on the bottom surface of the end portion on the upstream side in the insertion direction D1 of the housing 240 of the developing device 24 in each detachable unit 20. Each is provided, and is composed of four mated protrusions 85Y, 85M, 85C, 85K as a whole. Each fitting projection 85 (Y, M, C, K) is predetermined at a predetermined position on the partition screen portion 249 of the housing 240 of the developing device 24 in each detachable unit 20 and on the lower side. It is formed in a shape (for example, a prismatic shape) protruding by the length of.

  That is, the four fitted protrusions 85Y, 85M, 85C, and 85K correspond to positions corresponding to any one of four fitting grooves (81Y, 81M, 81C, and 81K) described later in the mounting portion 13. Is formed. Moreover, the four to-be-fitted protrusions 85 (Y, M, C, K) are formed in the same shape as each other, and only the positions where they are provided are different. Incidentally, the to-be-fitted protrusion 85 is formed at a position inward from the inner surface of the lowermost end portion 240 d of the housing 240 in the developing device 24 by the length of the fitting groove 81.

<Configuration of exposure apparatus>
As shown in FIG. 13 and the like, the exposure device 23 includes a light emitting structure 230 having a light emitting source 231 and a direction in which the light emitting structure 230 is moved toward and away from the photosensitive member 21 (directions indicated by arrows M1 and M2). It is comprised with the support structure part 232 supported so that it may move.

  As shown in FIG. 14B and the like, the light emitting structure 230 includes a light emitting source 231 formed by arranging a plurality of light emitting elements (LEDs, etc.) on a substrate along the axial direction (entire area) of the photosensitive drum 21. In addition, an optical component 233 such as a lens that emits light emitted from the light source 231 while focusing on the photosensitive drum 21, a support member 234 that supports the light source 231 and the optical component 233, and the like are provided.

  As shown in FIG. 13 and FIG. 14B, the support structure portion 232 includes a bowl-shaped main body 235 in which a housing portion for housing the light emitting structure portion 230 is formed, and the main body 235 is attached to the mounting portion 13 of the housing 10. A mounting projection 236 and a mounting plate 237 are provided. The housing portion of the main body 235 is formed as a space surrounded by an elongated rectangular bottom plate 235a extending along the axial direction of the photosensitive drum 21 and two side plates 235b that rise from the longitudinal end portion of the bottom plate 235a and face each other. Has been.

  Further, the support structure portion 232 swings to support the light emitting structure portion 230 in a swingable manner at the end portions on the downstream side in the insertion direction D1 of the detachable unit 20 in both longitudinal ends of the housing portion of the main body 235. A support portion 238 is provided. As shown in FIG. 14B, the swing support portion 238 is in contact with an end portion 234a on the downstream side in the insertion direction D1 in the support member 234 of the light emitting structure portion 230 with a point or a line from the lower side. A supporting fulcrum member 239 is arranged. As a result, the light emitting structure 230 swings in the directions indicated by the arrows M1 and M2 around the fulcrum member 239 in the housing portion of the support structure 232.

  The light emitting structure 230 is guided to the end of the detachable unit 20 on the upstream side in the insertion direction D1 so that the light emitting structure 230 is swung in a direction approaching the photosensitive drum 21 in the detachable unit 20. 27 is provided.

  The guided portion 27 is disposed on an enclosure frame 271 provided in a state of extending and projecting to an end portion on the upstream side in the insertion direction D1 of the support member 234 constituting the light emitting structure portion 230, and a lower surface of the support member 234. The swing member 272 that swings in the vertical direction within the inner space of the surrounding frame 271 with the swing fulcrum portion as the center, and the guide accommodation in the side plate 201A of the detachable unit 20 are provided at the tip of the swing member 272. The contact member 273 for positioning which contacts the contact receiving surface 204a which becomes the ceiling surface of the part 204, and a plate spring 274 which elastically presses the swinging member 272 so as to swing downward.

  When the detachable unit 20 is mounted on the mounting portion 13, the guided portion 27 moves in contact with a later-described guide portion (28) provided in the guide housing portion 204 of the detachable unit 20, thereby causing the light emitting structure portion 230. The end on the upstream side in the insertion direction D1 is guided to move in the direction M1 approaching the photosensitive drum 21. On the other hand, when the guided portion 27 is not in contact with a later-described guiding portion (28), the light emitting structure portion 230 has an end portion on the upstream side in the insertion direction D1 in the accommodating portion of the supporting structure portion 232. In 232, the moving state moves in the direction M2 away from the photosensitive drum 21 by its own weight.

Here, as shown in FIG. 9, FIG. 14A and the like, the guide housing portion 204 in the detachable unit 20 has a light emitting structure portion 230 on the inner surface of the lower portion facing the installation space portion 203 of the exposure device 23 of the side plate 201 </ b> A. It is a structure part which formed the space for accommodating the to-be-guided part 27 arrange | positioned at the one end part. Further, as shown in FIG. 14A and the like, the guide accommodating portion 204 includes a contact receiving surface (ceiling surface) 204a and a lower surface (bottom surface) that are substantially flat parallel to the axial direction of the photosensitive drum 21 in the detachable unit 20. ) 204b.
In addition, the guide portion 28 provided in the guide housing portion 204 is configured by the lower inner wall surface (bottom surface) 204 b in the guide housing portion 204. The guide portion 28 is a portion having a shape and strength capable of receiving a spring force (F2) by the leaf spring 274 in the guided portion 27.

As shown in FIG. 14B and the like, the plate spring 274 is configured by a plate spring that is bent in an S shape as a whole. Further, the leaf spring 274 has an S-shaped central portion fixed to the swinging member 272, and an upper end portion of the S-shape comes into contact with the support member 234 of the light emitting structure 230 or a part of the enclosure frame 271; The lower end portion of the S-shape is attached as a free end so as to be exposed to the lower side of the swing member 272 and the surrounding frame 271.
Further, the lower end of the S-shape of the leaf spring 274 is particularly easily introduced into the internal space (particularly the lower inner wall surface 204b) of the guide housing portion 204 of the detachable unit 20 when the detachable unit 20 is inserted into the mounting portion 13. A shape having an introduction surface portion 274a composed of an inclined surface having a rising slope and an installation end portion 274b that becomes a horizontal plane stably held on the bottom surface 204b of the guide housing portion 204 when it is housed in the guide housing portion 204. Is formed.

  Further, the leaf spring 274 is used when the guided portion 27 of the exposure apparatus 23 is accommodated in the accommodating space of the guiding accommodating portion 204 of the guiding portion 28 in the side plate 201A of the detachable unit 20 and the detachable unit 20 is finally positioned. In addition, the light emitting structure 230 of the exposure device 23 functions as a first pressing member that elastically presses the light emitting structure 230 toward the photosensitive drum 21. For this reason, the leaf spring 274 is set to press the light emitting structure 230 against the photosensitive drum 21 with a required spring force F2 (FIG. 47), for example.

  In the support structure portion 232, a first guide portion 75 is provided on one side plate 235b constituting the housing portion of the main body 235 for guiding the movement of insertion and extraction when the attachment / detachment unit 20 is attached / detached.

The first guide portion 75 has a predetermined length (guide) along the insertion direction D1 and the extraction direction D2 of the detachable unit 20 on the outer surface of the side plate 235b located on the side of the support structure portion 232 facing the developing device 24. The length is formed as a rail-shaped portion extending linearly at GL3 (FIGS. 13 and 28). Further, since the first guide portion 75 is set in a direction inclined so that the insertion direction D1 of the detachable unit 20 becomes an upward gradient toward the downstream side of the insertion direction D1, as described above, In correspondence with the inclined direction, the end portion 75a on the downstream side in the insertion direction D1 of the guide portion 75 is in a state relatively higher than the end portion 75b on the upstream side. Specifically, the first guide portion 75 is formed in a shape in which there are linear guide surfaces 75c and 75d extending above and below the first guide portion 75 so as to correspond to the direction inclined by the upward gradient.
When the first guide portion 75 is fitted into the first guided portion 71 of the detachable unit 20, the first guide portion 75 guides the detachable unit 20 along the insertion direction D1 and the extraction direction D2, respectively. However, the guide portion 75 functions as a temporary guide portion that guides only when the first guided portion 71 is fitted, as will be described later.

  As shown in FIGS. 14B, 15, 20, 32, and the like, the exposure apparatus 23 having the above-described configuration has a predetermined portion in the mounting portion 13 of the housing 10 via the support structure portion 232 thereof. (Installation surface 133: FIG. 21).

<Configuration of housing mounting part>
On the other hand, the mounting portion 13 of the housing 10 to which these detachable units 20 (Y, M, C, K) are detachably mounted has four detachable units 20 as shown in FIGS. A plate-shaped mounting base 131 to be installed, and the mounting base 131 is installed at a part on the downstream side (back side) of the detachable unit 20 in the insertion direction D1 to hold the end of the detachable unit 20 in the insertion direction D1 downstream side. And the support plate 301 on the near side that is installed above the portion of the mounting base 131 that is upstream (front side) in the insertion direction D1 of the detachable unit 20 and constitutes a part of the intermediate transfer device 30. It has.

  First, the mounting base 131 is partitioned into parts 132 (Y, M, C, K) that are partitioned so that the four detachable units 20 (Y, M, C, K) are individually mounted. For example, the detachable unit 20Y for yellow (Y) is attached to the segmented portion 132Y. The mounting base 131 is tilted with respect to the reference horizontal plane in the housing 10 in correspondence with the mounting / dismounting unit 20 (Y, M, C, K) being tilted as described above. (FIG. 16, FIG. 21, etc.). The divided portions 132 (Y, M, C, K) are configured as regions that extend long in the direction along the insertion direction D1 and the like of the detachable unit 20, and an installation surface portion for attaching the exposure device 23 to a part thereof. 133 is formed (FIG. 21 etc.).

  In the part 132 (Y, M, C, K) divided in the mounting base 131, second guide portions 77A and 77B are provided at the upper end of the part that also serves as the boundary partition plate, respectively. The second guide portions 77A and 77B guide the movement of each detachable unit 20 and support the detachable unit 20 when the second guided portion 73 in each detachable unit 20 is fitted. .

  The second guide portions 77A and 77B are bent downward toward the inside of each part at two predetermined positions (positions) in the insertion direction D1 of the detachable unit 20 at the upper end of the part that also serves as the boundary partition plate. It is formed as a plate-shaped portion having a shape that forms a guide space. As for 2nd guide part 77A, 77B, guide length GL in the insertion direction D1 of the attachment / detachment unit 20 is set to predetermined length GL1, GL2 (FIG. 28).

  In addition, the second guide portions 77A and 77B have a second guided portion 73 in the insertion / detachment unit 20 at least in the insertion direction D1 in the process (on the way) of being attached to the part 132 where the attachment / detachment unit 20 is separated. When the guide unit 77A located on the upstream side or the guide units 77A and 77B is fitted in at the same time and the detachable unit 20 is normally attached to the separated part 132, the removal unit 20 The second guided portion 73 is placed in a position (so as to be in a positional relationship) where it is fitted into the guide portion 77B located on the downstream side in the insertion direction D1 (FIG. 28).

Next, as shown in FIG. 20 to FIG. 25 and the like, the holding portion 15 in the mounting portion 13 is one corresponding to each of the divided portions 132 (Y, M, C, K) of the mounting portion 13. Placed one by one.
The holding portion 15 is fixed to the plate-like main body 150 with the holding hole 16 for fitting and holding the shaft portion 214 of the photosensitive drum 21 in each detachable unit 10 and the projection 205 in each detachable unit 10 being fitted. The mounting hole 17 is configured as a member provided. Further, the holding portion 15 is attached in a state of being fixed to a support frame (not shown) disposed on the back side of the mounting portion 13. Reference numerals 158A and 158B in FIGS. 23 to 25 are screw through holes for passing fixing screws used when the main body 150 of the holding portion 15 is fixed to a support frame (not shown). Reference numeral 159 in FIG. 25 denotes a fixing screw passed through the screw through hole 158B.

  As shown in FIGS. 21 to 25, the holding hole 16 is formed as a substantially circular through hole having a size that allows the shaft portion 214 of the photosensitive drum 21 to be fitted into the main body 150 of the holding portion 15. Has been. In addition, a pressing member 18 that elastically presses the shaft portion 214 of the photosensitive drum 21 toward the upper surface portion 16 a of the holding hole 16 from below is disposed in the holding hole 16.

As shown in FIGS. 23 and 24, the pressing member 18 includes a main body portion 180 having a semicircular pressing surface 182 and a coil spring 19 that elastically presses the main body portion 180 upward. . The main body portion 180 has a plate-like shape that is curved in a semicircular arc as a whole, and is formed as a pressing surface 182 that presses the upper surface portion in contact with and supports the shaft portion 214 of the photosensitive drum 21 from below. Yes.
The pressing member 18 has a plate-like protruding portion 183 that protrudes toward the downstream side in the insertion direction D1 of the detachable unit 20 at a lower portion of the main body portion 180, and a lower portion of the main body portion 180. The upper end opening 19a of the coil spring 19 is inserted and fixed, and the pressing member 18 is moved to the outer surfaces that are the semicircular arc ends of the main body 180. Insertion protrusions 185 and 186 that are inserted into movement restriction holes (154 and 155) to be described later for restriction are provided.

Further, as shown in FIG. 24 and FIG. 25, the pressing member 18 includes a first end surface portion 182 a in which the pressing surface 182 of the main body portion 180 exists on the upstream side in the insertion direction D <b> 1 of the detachable unit 20. It is divided into a second end surface portion 182b.
The second end surface portion 182b is formed as a surface parallel to a reference horizontal plane (two-dot chain line SH in FIG. 25). As shown in FIG. 25, the first end surface portion 182a is formed in a shape including an inclined surface 182c that is formed along the insertion direction D1 of the detachable unit 20 (a direction that forms an angle θ1 with respect to the reference horizontal plane SH). Has been. The inclined surface 182c is formed as a surface that forms an angle θ2 with respect to the reference horizontal plane SH. The angle θ2 at this time is set, for example, within a range of 5 ° to 20 °. The first end surface portion 182a in the first embodiment is formed by an inclined surface 182c whose entire area forms an angle θ2 with respect to the reference horizontal plane SH.

Further, the pressing member 18 is a protrusion that fits into a recess 214b (FIGS. 9, 14, and 25) formed in the lower surface portion of the shaft portion 214 of the photosensitive drum 21 in each detachable unit 20 at the lower center of the pressing surface 182. 187 is provided. The recess 214b in the shaft portion 214 is formed in a recess shape having a required depth whose opening shape is a rectangle. Further, the protrusion 187 is set to be hooked with the end portion of the recess 214b at the downstream end portion in the insertion direction D1 by fitting with the recess 214b. The height of the protrusion 187 is set, for example, within a range of 0.2 mm to 1 mm.
The protrusion 187 in the first embodiment is formed in a shape in which a portion (top) on the upstream side in the insertion direction D1 of the detachable unit 20 has an inclined surface 187a continuous with the inclined surface 182c of the pressing surface 182 of the main body portion 180. ing. In addition, the protrusion 187 has a downstream end portion in the insertion direction D1 formed of a slope or an arcuate curved surface that is inclined downward at an angle of, for example, 60 ° or less with respect to the insertion direction D1 of the detachable unit 20. ing.

  On the other hand, as shown in FIG. 23 and FIG. 24, the main body 150 of the holding portion 15 has a recessed shape in which the accommodation arrangement portion 151 that accommodates and arranges the pressing member 18 and the coil spring 19 in the lower portion of the holding hole 16. Is provided. The housing placement portion 151 includes an upper placement portion 151 a that houses the pressing member 18 and a lower placement portion 151 b that houses the coil spring 19. The upper arrangement portion 151 a is a portion formed in a semicircular arc-shaped depression shape corresponding to the form of the main body portion 180 of the pressing member 18. The lower arrangement portion 151b is a portion formed in a prismatic depression shape that protrudes downward from the center of the lower portion of the upper arrangement portion 151a.

The upper arrangement portion 151a for the pressing member is set to have a dimensional shape that can displace the pressing member 18 in a direction (N1, N2) approaching and separating from the upper surface portion 16a of the holding hole 16. Further, the upper arrangement portion 151a moves in the above-described displacement directions N1 and N2 of the pressing member 18 with the protrusion 183 of the pressing member 18 fitted in the lower portion of the holding hole 16 corresponding to the center of the lower portion. A guide support portion 153 is provided for guiding and supporting. Furthermore, the upper arrangement portion 151a includes, at both ends of the semicircular arc, a movement range in the directions N1 and N2 in which the pressing member 18 is displaced, and a movement range in the insertion direction D1 of the detachable unit 20 toward the upstream side and the downstream side. Movement restriction holes 154 and 155 for restricting the movement are provided. The guide support part 153 is formed as a part cut out including the lower part of the holding hole 16, for example. The movement restricting holes 154 and 155 are formed as depressions or through holes each having a rectangular opening. Further, the lower arrangement portion 151 b for the coil spring is formed by connecting the spring fixing portion 184 and the coil spring 19 in the main body 180 of the pressing member 18. It is formed with dimensions that can be accommodated. On the lower end surface of the lower arrangement portion 151b, a projecting spring holding portion 156 is provided in which the lower end opening portion 19b of the coil spring 19 is inserted and held with a gap.

  And this holding | maintenance part 15 attaches and fixes the upper end part of the coil spring 19 to the lower part (spring fixing part 184) of the main-body part 180 of the press member 18, Then, the holding | maintenance part of the press member 18 and the coil spring 19 is hold | maintained. Assembling is performed by accommodating and arranging the upper arrangement portion 151a and the lower arrangement portion 151b of the accommodation arrangement portion 151 in the 15 main bodies 150.

  At this time, the pressing member 18 fits the protruding portion 183 in the main body portion 180 into the guide portion 153 in the upper housing placement portion 151a, and restricts the insertion protrusions 185 and 186 in the main body portion 180 in the housing placement portion 151a. Insert into holes 154 and 155. Thereby, the whole pressing member 18 is accommodated and arrange | positioned by the upper arrangement | positioning part 151a. Further, the coil spring 19 has its lower end opening portion 19a inserted into the spring holding portion 156 in the lower arrangement portion 151b. Thereby, the whole coil spring 19 is accommodated and arrange | positioned by the lower arrangement | positioning part 151b. As a result, the pressing member 18 is elastically pressed in the direction N1 approaching the upper surface portion 16a of the holding hole 16 by the spring force (F3) of the coil spring 19 in the upper arrangement portion 151a of the accommodation arrangement portion 151. (FIGS. 18 and 47).

At this time, the pressing member 18 is accommodated in a state where there is a gap S5 so that the entire pressing member 18 can be displaced vertically with respect to the accommodating / disposing portion 151a (FIG. 23). As a result, the pressing member 18 is disposed in a state where it can be displaced in the directions N1 and N2 approaching and separating from the upper surface portion 16a of the holding hole 16.
Further, the pressing member 18 is inserted and held in a state where the insertion protrusions 185 and 186 can generate a gap S6 vertically and horizontally with respect to the movement restricting holes 154 and 155. Here, the upper and lower gaps in the upper and lower and left and right gaps S6 are gaps that permit displacement in the approaching direction N1 and the separating direction N2, and the left and right gaps in the upper and lower and left and right gaps S6 are the insertion directions. It is a gap that allows displacement in D1 and extraction direction D2. As a result, the pressing member 18 is arranged in a state in which the pressing member 18 can be displaced in the directions N1 and N2 approaching and separating from the upper surface portion 16a of the holding hole 16 in the housing arrangement portion 151 of the main body portion 180 of the holding portion. It arrange | positions in the state which can be displaced so that 20 insertion direction D1 (or extraction direction D2) may be met.

In particular, as shown in FIGS. 25, 41, etc., the pressing member 18 has a pressing surface 182 on the upstream side of the insertion direction D1 of the detachable unit 20 (or the extraction direction D2). It is attached in a state where it can be displaced so as to be inclined in the direction P toward the downstream side. In other words, the pressing member 18 has a required angle θ4 from the vertical plane (solid line) with respect to the reference horizontal plane SH in the housing placement portion 151 of the holding portion 15, as indicated by the two-dot chain line VL in FIG. It is configured to be in a slightly forward tilted state (posture). The angle θ4 at which the pressing member 18 tilts is set to be a value equal to or larger than the angle θ1 with respect to the reference horizontal plane SH in the insertion direction D1 of the detachable unit 20, for example.
Such displacement of the pressing member 18 in each of the directions N1, N2, and P is also possible because the pressing member 18 is supported by the coil spring 19 at the lower portion thereof with an elastic force.

  Next, the front support plate 301 of the intermediate transfer device 30 is a plate-like member that supports the intermediate transfer belt 31, the plurality of support rolls 32, the belt cleaning device 36, and the like, as shown in FIG. The mounting unit 13 is disposed at a position on the upstream side (front side) in the insertion direction D1 of the detachable unit 20. Reference numeral 363 in FIG. 15 is a terminal discharge portion of a transport pipe that transports toner or the like removed by the belt cleaning device 36.

  The entire support plate 301 has a shape having a lower side portion 301 a extending in a state substantially parallel to the inclined surface of the mounting base 131 of the mounting portion 13. Further, the support plate 301 has four positioning receiving shape portions in which the contact surface portion 206 for positioning on the side plate 201A of each detachable unit 20 (Y, M, C, K) contacts and is positioned on the lower side portion 301a. 302, four third guide portions 304 that guide the movement of the attachment / detachment unit 20 when the attachment / detachment unit 20 is attached by contacting the protruding end portions 246 of the attachment / detachment unit 20 (Y, M, C, K) in the developing device 24. Is provided.

  The positioning receiving shape portion 302 is provided with a contact portion formed in an arc shape that matches the shape of the contact surface in the contact surface portion 206 at a position facing the positioning contact surface portion 206 in each detachable unit 20. The third guide portion 304 changes at a position facing the protruding end portion 246 in the developing device 24 when the protruding end portion 246 contacts and moves when the detachable unit 20 is attached or detached (particularly in a direction approaching the intermediate transfer belt 31). It is composed of a plate-like member that regulates and guides the fluctuation (displacement to E1). For this reason, the 3rd guide part 304 functions as a control part at the time of attachment / detachment of the attachment / detachment unit 20.

In addition, as shown in FIGS. 20 to 22, 26, and the like, the mounting portion 13 is provided with means for preventing erroneous mounting of the detachable unit 20 at the end of the mounting base 131 that is upstream in the insertion direction D1 of the detachable unit 20. A fitting groove 81 is provided.
The fitting groove 81 is provided for each part 132 (Y, M, C, K) divided in the mounting base 131, and is composed of four fitting grooves 81Y, 81M, 81C, 81K as a whole. These fitting grooves 81 (Y, M, C, K), as shown in FIG. 26 and the like, are formed on a section screen section 134 that is partitioned into a common area and a planar shape at the end of the mounting base 131. Of these, a groove-shaped portion having a predetermined depth and length extending along the insertion direction D1 of the detachable unit 20 is formed at a predetermined position set in advance.
The fitting groove 81 is formed in a linear groove shape whose upper side is opened (released). Further, the depth of the fitting groove 81 (Y, M, C, K) is set to a dimension slightly larger than the protruding height of the fitting projection 85 (Y, M, C, K) in each detachable unit 20. ing. Furthermore, the lengths along the insertion direction D1 of the fitting grooves 81 (Y, M, C, K) are all set to a common dimension. For example, when the detachable unit 20 is inserted into the mounting portion 13, the length is extended to a position where the mated protrusion 81 (Y, M, C, K) can be stopped by colliding at a predetermined insertion stop position. Is set to the specified length.

  The fitting grooves 81Y, 81M, 81C, 81K in the first embodiment are formed at positions that are the most right in this order in the direction intersecting the insertion direction D1 in the common section screen portion 134, and slightly to the right from the center. , A position slightly to the left of the center, and a position to the left most (FIGS. 20 and 26). The fitting projections 85 (Y, M, C, K) in the detachable unit 20 are respectively formed at positions corresponding to the forming positions of the fitting grooves 81 (Y, M, C, K).

Further, as shown in FIGS. 21, 26, etc., the mounting portion 13 has a lower end portion of the operation lever 50 in the detachable unit 20 at an end portion of the mounting base 131 that is upstream in the insertion direction D1 of the detachable unit 20. A fixed surface portion 135 for holding the displacement bottom portion 53 is provided.
The fixed surface portion 135 is a portion whose upper surface is formed by a flat surface, for example, and is provided for each of the divided portions 132 (Y, M, C, K). When the operation lever 50 is operated when positioning the detachable unit 20, the fixed surface portion 135 moves and contacts the displacement bottom 53 of the operation lever 50, and holds the displacement bottom 53 in the contacted state. (FIG. 43).

Further, as shown in FIG. 26, FIG. 27, etc., the mounting portion 13 is configured such that the protruding portion 74 of the detachable unit 20 is fitted into the end portion of the mounting base 131 that is downstream in the insertion direction D1 of the detachable unit 20. An insertion portion 78 is provided to hold the
The fitting portion 78 extends upward along a direction (a direction E1 approaching the intermediate transfer belt 31) when an end portion of the detachable unit 20 on the upstream side in the insertion direction D1 is displaced in the positioning direction in the mounting portion 13. It is formed as a site | part which consists of a notch shape which was cut | disconnected so that the upper end might be closed. Further, the insertion portion 78 is formed in a state of being present at an end portion of the fixed surface portion 135 near the fitting groove 81 side. One insertion portion 78 is also provided for each segmented portion 132 (Y, M, C, K).

FIG. 28 shows each forming position and guided length Gm related to the first guided portion 71 and the second guided portion 73 provided in the detachable unit 20, and the first provided in the exposure device 23 in the mounting portion 13. The respective formation positions and the guide lengths GL related to the second guide portions 77A and 77B provided for each of the divided portions 132 of the guide portion 75 and the mounting portion 13 are shown.
In FIG. 28, one of the divided parts 132 of the mounting portion 13 is shown in the middle position, and the detachable unit 20 (insertion completion position) correctly inserted in the upper position is seen from the bottom side. In this state, the detachable unit 20X that has been erroneously inserted into the lower position (the position during insertion) is viewed from the bottom side.

Among these, the first guide portion 75 in the mounting portion 13 (exposure apparatus 23) is a guide portion having a relatively long guide length GL3 along the insertion direction D1, and the first guide portion 71 in the detachable unit 20. For a relatively long time. On the other hand, the first guide portion 75 has a position where the end portion 75a on the downstream side in the insertion direction D1 does not guide the first guided portion 71 in the correctly inserted / detached unit 20 (shown in the upper position). It is set to end before (guidance end position).
Further, the second guide portions 77A and 77B in the mounting portion 13 have guide lengths GL1 and GL2 that are separately arranged at the upstream end and the downstream end along the insertion direction D1. Thus, the guide part 77A starts to guide the second guided part 73 in the detachable unit 20 first, and then the guide part 77B is also added for guidance. On the other hand, the second guide portions 77A and 77B are set so as to guide and support the second guided portion 73 in the correctly inserted and removed detachable unit 20 (shown in the upper position in FIG. 28).

FIG. 29 shows the formation position and guided length Gm related to the protruding end 246 as the restricting portion provided in the developing device 24 of the detachable unit 20, and the third provided on the support plate 301 of the intermediate transfer device 30 in the mounting portion 13. The formation position regarding the guide part 304 and the guide length GL are shown.
In FIG. 29, similarly to the case of FIG. 28, one of the divided parts 132 in the mounting portion 13 is shown in the middle position, and the insertion / removal unit 20 (insertion completed position) correctly inserted in the upper position is shown. ) In the state when viewed from the bottom surface side, and the detachable unit 20X (position in the middle of insertion) erroneously inserted in the lower position is illustrated in the state when viewed from the bottom surface side.

  The third guide portion 304 in the mounting portion 13 (support plate 131) is a guide portion having a short guide length GL4 located at the upstream end portion in the insertion direction D1, and protruding as a restricting portion in the detachable unit 20. The end 246 is guided for a relatively long time corresponding to the guided length (Gm3) (FIG. 29). On the other hand, the formation position of the third guide portion 304 does not guide the protruding end portion 246 as a restricting portion of the detachable unit 20 (shown in the upper position) when it is correctly inserted into the mounting portion 13 (guide). It is set to exist at the end position (specifically, the most upstream position in the insertion direction D1).

<Details of attaching / detaching operation of attaching / detaching unit>
Hereinafter, the attaching / detaching operation of the attaching / detaching unit 20 (Y, M, C, K) to the attaching portion 13 will be described in detail.

◎ Insertion stage at the time of mounting First, at the time of mounting, as shown in FIG. 15 and the like, first, each detachable unit 20 (Y, M, C, K) is first divided into a portion 132 (Y, M) , C, K). Specifically, the detachable unit 20 moves along the insertion direction D1 with respect to the corresponding portion 132 of the mounting portion 13 with the side plate 201B on which the shaft portion 214 and the like of the photosensitive drum 21 is disposed at the top. Let Incidentally, when performing this insertion work, the operation lever 50 is brought into a tilted state (a state in which it is swung in the tilting direction indicated by the arrow J2 in FIGS. 16, 36, etc.).

  At this time, the detachable unit 20 has an exposure device 23 formed below the unit 20 with respect to a mounting space formed between the mounting base 131 and the intermediate transfer device 30 (support plate 301) in the mounting portion 13. In the installation space 203, the exposure apparatus 23 attached in advance to the segmented part 132 is moved in such a state as to enter. Then, as shown in FIGS. 30 to 33 and the like, the attachment / detachment unit 20 is first located on the exposure device 23 side of the attachment portion 13 with respect to the first guided portion 71 on the lower side of the attachment / detachment unit 20. One guide portion 75 is fitted, and guidance by the first guide portion 75 is started. Thereafter, the protruding end portion 246 on the upper side of the detachable unit 20 starts to contact the third guide portion 304 on the support plate 301 side of the mounting portion 13, and guidance (and regulation) by the third guide portion 304 is performed. Be started.

  Subsequently, when the attachment / detachment unit 20 further moves along the insertion direction D1, the second guided portion 73 on the lower side of the attachment / detachment unit 20 moves to the second guide portion 77A on the near side on the attachment portion 13 side. It is inserted and guidance by the second guide part 77A is also started (FIG. 32).

  Thereby, in the insertion / removal unit 20, the part on the side where the developing device 24 is disposed is guided by the first guide part 75 and the guide by the third guide part 304 (the third guide part 304). And the portion on the side where the drum cleaning device 26 is disposed is held and stabilized by the second guide portion 77A on the mounting portion 13 side. Move in the same state.

  As a result, the detachable unit 20 is guided in a state where it is supported at three points by the first guide portion 75, the second guide portion 73, and the third guide portion 246, and proceeds along the insertion direction D1. Inserted stably. For this reason, the photosensitive drum 21 in the detachable unit 20 is kept at a space (gap) with the light emitting structure 230 (optical component 233) of the exposure apparatus 23 on the lower side thereof, so that contact with the light emitting structure 230 is avoided. In addition, since the gap (gap) between the intermediate transfer device 30 and the intermediate transfer belt 31 is maintained on the upper side, contact with the intermediate transfer belt 31 is also avoided. In addition, the detachable unit 20 is prevented from unexpectedly moving (fluctuating) upward by being guided (restricted) by the third guide portion 304 of the support plate 301 via the protruding end portion 246 of the developing device 24. Is done.

  As shown in FIG. 34 and the like, the detachable unit 20 at the time of insertion finally has a photosensitive drum 21 at an end portion (end portion on the side where the side plate 201B is present) on the downstream side in the insertion direction D1. The shaft portion 214 and the mounting fixing projection 205 are moved until they are fitted into the holding holes 16 and the mounting holes 17 in the holding portion 15 arranged at the end portion of the mounting portion 13 on the downstream side in the insertion direction D1. It has become.

  However, in this attachment / detachment unit 20 (Y, M, C, K), as shown in FIG. 35 and the like, erroneous attachment prevention is performed at a position on the near side (in the middle of insertion) where the attachment portion 13 reaches the final insertion stop position. Whether or not the mating protrusions 85 (Y, M, C, K) as the means match with the fitting grooves 81 (Y, M, C, K) as the erroneous mounting preventing means in the mounting portion 13. Is confirmed. FIG. 36 schematically shows the detachable unit 20 and the mounting portion 13 in FIG. 35 as a cross section taken along the line QQ.

  Here, for example, with respect to the portion 132C divided for cyan (C) color in the mounting portion 13, other colors (any of Y, M, and K) that are not the detachable unit 20C for cyan (C) color are used. Assume that the detachable unit 20X (actually any of the detachable units 20Y, 20M, and 20K) is erroneously inserted (erroneously mounted).

In this case, the erroneously mounted detachable unit 20X is inserted into the mounting base 131 in the mounting portion 13 so that the outer surface of the end portion (side plate 201A) on the upstream side in the insertion direction D1 is inserted as shown in FIGS. It stops at a position on the near side by a predetermined distance α with respect to the end portion 131e on the upstream side in the direction D1. That is, the mating protrusion 85 (any of Y, M, and K) as the erroneous mounting preventing means in the detachable unit 20X does not match the fitting groove 81C as the erroneous mounting preventing means on the mounting portion 13 side. Therefore, it is not fitted into the fitting groove 8C, but it abuts on the front side portion 134a (FIG. 26, etc.) of the section screen 134 and is prevented from moving in the insertion direction D1.
By stopping the insertion movement, the user of the image forming apparatus 1 is informed that the detachable unit 20X is erroneously attached during the insertion.

At this time, in the erroneously mounted / removable unit 20X, the shaft portion 214 of the photosensitive drum 21 and the mounting projection 205 at the end portion (side plate 201B) on the downstream side in the insertion direction D1 are held by the holding portion 15 of the mounting portion 13. It will be in the state stopped in the position before the hole 16 or the attachment hole 17, and it does not insert (FIG. 34).
Further, the erroneously mounted / removable unit 20X is inserted to a position on the near side near the insertion completion position with respect to the segmented portion 132 (C) of the mounting portion 13. However, the detachable unit 20X at this time is, as shown in FIGS. 28 and 29, the first guided portion 71, the second guided portion 73, and the third guided portion on the detachable unit 20X side. The protruding end portion 246 of the part is guided by the first guide portion 75, the second guide portion 77A, and the third guide portion 304 on the mounting portion 13 side, so that unexpected movement is restricted. . For this reason, in the insertion process of the erroneously mounted detachable unit 20X, it is reliably prevented that the photosensitive drum 21 contacts the exposure device 23 on the lower side and the intermediate transfer belt 31 on the upper side. If such contact occurs, there is no possibility of inducing problems such as damage to parts.

  On the other hand, when the correct attachment / detachment unit 20 (Y, M, C, K) is correctly inserted into the separated regular part 132 (Y, M, C, K) of the mounting portion 13, each of the attachment / detachment units 20. The fitting protrusions 85 (Y, M, C, K) serving as erroneous mounting preventing means in the case respectively match the fitting grooves 81 (Y, M, C, K) serving as erroneous mounting preventing means on the mounting portion 13 side. Will do.

  At this time, each correct attaching / detaching unit 20 (Y, M, C, K) is fitted to a fitting projection 85 (Y, M, C) as an erroneous mounting preventing means, as shown in FIGS. , K) is inserted into the fitting groove 81 (Y, M, C, K) as an erroneous mounting preventing means on the mounting portion 13 side, and is inserted further into the rear side at each divided portion 132. Move to be. Further, since each of the detachable units 20 (Y, M, C, K) at this time is confirmed to be erroneously mounted and further inserted, the end portion (side plate) on the downstream side in the insertion direction D1. 201B) is fitted into the holding hole 16 and the mounting hole 17 in the holding part 15 on the mounting part 13 side (FIGS. 16 and 34).

  By the above, each attachment / detachment unit 20 (Y, M, C, K) is in a state of being inserted into each of the separated portions 132 (Y, M, C, K) of the mounting portion 13.

  As described above, the attachment / detachment units 20 (Y, M, C, and K) when the insertion is completed all have upstream ends in the insertion direction D1 from the intermediate transfer device 30 in the mounting portion 13. It is accommodated in a state of being displaced in the separating direction (FIG. 16). Further, the detachable unit 20 at this time has an outer periphery of the intermediate transfer belt 31 in the intermediate transfer device 30 that is positioned and attached in advance to the mounting portion 13 on the end portion side where the photosensitive drum 21 is upstream in the insertion direction D1. The surface 31a (actually, the belt portion supported by the transfer roll of the primary transfer device 34) is displaced downwardly, and the entire unit is maintained in a state where one side is lowered and inclined. Thereby, in the process in which the detachable unit 20 is inserted into the mounting portion 13, there is no possibility that the photosensitive drum 21 in the detachable unit 20 contacts the intermediate transfer belt 31.

  Further, when this insertion is completed, the detachable unit 20 (Y, M, C, K) is attached to the side plate 201A as shown in FIG. None of the provided contact surface portions 206 for positioning is in contact with the positioning receiving shape portion 302 of the support plate 30 in the intermediate transfer device 30 and is in a separated state.

  At this time, in the detachable unit 20, the shaft portion 214 of the photosensitive drum 21 is fitted into the holding hole 16 of the holding portion 15 in the mounting portion 13. As a result, the shaft portion 214 of the detachable unit 20 is elastic in the direction N1 approaching the upper surface portion 6a of the holding hole 16 by the pressing member 18 pressed against the holding hole 16 by receiving the spring force (F3) of the coil spring 19. Is kept pressed (FIGS. 16, 41, and 47).

  Furthermore, since the attachment / detachment unit 20 at this time is after the confirmation of the erroneous attachment is completed (after the fitting projection 85 is fitted in the fitting groove 81), the first guided portion 71 is attached. The first guide portion 75 on the side of the portion 13 is no longer engaged with the first guide portion 75 (FIG. 28), and the projecting end portion 246 that is the restraining portion is connected to the third guide portion 304 on the mounting portion 13 side. There is no contact state (FIG. 29). For this reason, the part of the developing device 24 in the detachable unit 20 is released from the guidance by the first guide part 75 and the guidance and regulation by the third guide part 304.

  On the other hand, the detachable unit 20 at this time is in a state in which the second guided portion 73 is fitted only to the second guide portion 77B on the back side of the mounting portion 13 at the downstream end portion in the insertion direction D1. On the other hand, the second guided portion 73 is not fitted to the second guiding portion 77A on the front side of the mounting portion 13 at the upstream end in the insertion direction D1 (FIG. 28). Therefore, the part of the drum cleaning device 26 in the detachable unit 20 is supported by the second guide portion 77B at the downstream end in the insertion direction D1, while the upstream end in the insertion direction D1. The part is released from the guidance and support by the second guide part 77A.

  As a result, when the insertion is completed, the detachable unit 20 is held and supported by the holding portion 15 of the mounting portion 13 and the second guide portion 77B at the downstream end in the insertion direction D1. In addition, at the end on the upstream side in the insertion direction D1, the guide part 75, 77A, 304 is released from the guidance (regulation). Thereby, the detachable unit 20 is brought into a state in which the next positioning operation can be performed.

  Further, in the image forming apparatus 1, as described above, the detachable unit 20 is inserted into the mounting unit 13 by moving along the insertion direction D1 inclined upward by the angle θ1 with respect to the reference horizontal plane SH. The shaft portion 214 of the photosensitive drum 21 corresponding to the downstream end portion in the insertion direction D1 of the detachable unit 20 is fitted into the holding hole 16 of the holding portion 15 while moving along the insertion direction D1. At this time, as shown in FIGS. 41 and 45, the pressing member 18 in the holding portion 16 is affected by the load and the contact state when the shaft portion 214 in the detachable unit 20 is in contact, so that the upper surface portion 16a of the holding hole 16 is reached. The pressure surface 182 is displaced so as to incline within the range of the angle θ4 in the direction P toward the upstream side of the insertion direction D1.

As a result, the holding hole 16 of the holding portion 15 is adapted to the shaft portion 214 of the photosensitive drum 21 that moves along the insertion direction D1 inclined upward as the pressing member 18 is displaced so as to be inclined in the direction P. As a result, the lower portion of the holding hole 16 (actually, the pressing surface 182 of the pressing member 18) is inclined. For this reason, the shaft portion 214 of the photosensitive drum 21 is smoothly fitted into the holding hole 16 of the holding portion 16 without receiving an external force such as unnecessary frictional resistance.
Further, the pressing member 18 is formed by an inclined surface 182c that is inclined so that the first end surface portion 182a on the upstream side in the insertion direction D1 on the pressing surface 182 extends along the insertion direction D1 (FIG. 25, FIG. 25). 41) The shaft portion 214 of the photosensitive drum 21 that moves along the insertion direction D1 that is inclined upward is smoothly applied to the inclined surface 182c without receiving an external force such as unnecessary frictional resistance from the pressing surface 182 of the pressing member 18. Proceed with guidance. Also by this, the shaft portion 214 of the photosensitive drum 21 described above can be smoothly fitted into the holding hole 16 of the holding portion 15.

Note that, when the image forming unit 20 is inserted into the mounting portion 13, the image forming unit 20 when the insertion is completed is strictly elastic in a direction opposite to the insertion direction D1 (extraction direction D2). To receive external force that is pushed back. This is because, for example, the transmitted gear 215 in the shaft portion 214 of the photosensitive drum 21 is coupled to a driving gear (not shown) disposed on the housing 10 side, or the driven side coupling 245 in the developing device 24 is coupled to the housing 10. By coupling with a drive-side coupling (not shown) arranged on the side, the reaction force generated by the coupling elastically pushes back the image forming unit 20 in the direction opposite to the insertion direction D1 (extraction direction D2). Because it works as a strong external force.
In addition, since the image forming unit 20 when the insertion is completed is not configured to be prevented from moving in the extraction direction D2, the attachment unit 13 may move in the extraction direction D2.

In this regard, in the image forming unit 20, when the shaft portion 214 of the photosensitive drum 21 is fitted into the holding hole 16 of the holding portion 15, as shown in FIG. The recess 214b provided in the fitting hole is engaged with the protrusion 187 provided on the pressing member 18 of the holding hole 16 and is caught.
As a result, when the insertion is completed, the image forming unit 20 is in a state where the recess 214b in the shaft portion 214 of the photosensitive drum 21 is engaged with the protrusion 18 in the pressing member 18 of the holding hole 16 and is thus caught. Inadvertent movement in the direction D2 is prevented.

Incidentally, the protrusion 187 in the pressing member 18 is formed in a shape in which a portion (top) on the upstream side in the insertion direction D1 has an inclined surface 187a continuous with the inclined surface 182c which is the first end surface portion 182a of the pressing surface 182. 25 (FIG. 25), the shaft portion 214 of the photosensitive drum 21 comes into contact with the pressing member 18 without receiving external force such as unnecessary frictional resistance due to the protrusion 187, and proceeds smoothly. This also makes it easier to smoothly fit the above-described shaft portion 214 of the photosensitive drum 21 into the holding hole 16 of the holding portion 16.
Further, since the projection 187 is formed in the shape having the inclined surface 187a, the recess 214b in the shaft portion 214 of the photosensitive drum 21 can be smoothly engaged with the projection 18 in the pressing member 18.

◎ Positioning step at the time of mounting Next, at the time of mounting, as shown in FIGS. 18, 19, 42 to 44, etc., each detachable unit 20 (Y, M, C, K) is divided into the mounting portions 13. Work for positioning at each of the formed portions 132 (Y, M, C, K) is performed. Specifically, the detachable unit 20 performs an operation of operating the operation lever 50 provided in each detachable unit 20 from the tilted state to the raised state.

At this time, in the detachable unit 20, the operation lever 50 is swung in the direction J <b> 1 raised with the rocking shaft portion 210 in the side plate 201 </ b> A of the detachable unit 20 as a fulcrum. The corner portion and the bottom surface portion are swung while being in contact with the fixed surface portion 135 of the mounting base 131 of the mounting portion 13. As a result, the operation lever 50 functions as a “lever” in which the upper part of the main body 51 above the bearing part 52 is a force point, the bearing part 52 is a fulcrum, and the displacement bottom part 53 is an action point.
For this reason, when the operating lever 50 is swung in the direction J1 to be raised, as shown in FIGS. 42, 43, etc., the displacement bottom 53 comes into contact with the fixed surface 135 and is stretched. The effect | action which lifts the bearing part 52 upward generate | occur | produces. As a result, the side plate 201 of the detachable unit 20 is lifted by the bearing portion 52 via the swing shaft portion 210. At this time, the displacement bottom 53 is displaced in the direction K1 approaching the bearing 52 against the spring force of the coil spring 67 (FIG. 10B), and the bottom thereof is in surface contact with the fixed surface 135. Finally, the fixed surface portion 135 is completely raised.

  By the swinging operation in the direction J1 generated by the operation lever 50, the detachable unit 20 has an end portion (side plate 201A) on the upstream side in the insertion direction D1 as shown in FIGS. The transfer device 30 is displaced in the direction E1 approaching the intermediate transfer belt 31.

  At this time, in the detachable unit 20, as shown in FIG. 42, the projecting portion 74 on the lower side of the side plate 201A is fitted into the fitting portion 78 on the mounting portion 13 side. As a result, the detachable unit 20 is guided in the direction in which the detachable unit 20 is displaced in the direction E1 approaching the intermediate transfer device 30, and finally the protruding portion 74 is held at a position in the middle of the fitting portion 78. Thus, positioning in the insertion direction D1 (and extraction direction D2) is performed. In the detachable unit 20, as shown in FIG. 19, the positioning contact surface portion 206 on the upper side of the side plate 201 </ b> A is positioned in contact with the positioning receiving shape portion 302 of the support plate 301 on the mounting portion 13 side. The

  As described above, each detachable unit 20 (Y, M, C, K) is positioned at the segmented portion 132 (Y, M, C, K) of the mounting portion 13, and the mounting to the mounting portion 13 is completed. Will be in a state. Accordingly, each detachable unit 20 (Y, M, C, K) is positioned at a position where the image forming operation can be performed in the mounting portion 3. The operation lever 50 at this stage is held in a self-supporting state when the bottom surface of the displacement bottom portion 53 comes into surface contact with the fixed surface portion 135 on the mounting portion 13 side.

  Further, when this positioning is completed, the detachable unit 20 (Y, M, C, K), when viewed from the front side in the insertion direction D1 in the mounting portion 13, as shown in FIG. All of the positioning contact surface portions 206 are in contact with the positioning receiving shape portion 302 of the support plate 30 in the intermediate transfer device 30.

  As described above, all of the detachable units 20 (Y, M, C, K) when the positioning (mounting) is completed are intermediate including the end side where the photosensitive drum 21 is upstream in the insertion direction D1. The transfer belt 31 (actually, the belt portion supported by the primary transfer roll 34 of the primary transfer device) comes into contact (FIGS. 18 and 47).

  At this time, the attachment / detachment unit 20 has its contact surface portion 206 for positioning brought into contact with the positioning receiving shape portion 302 formed on the support plate 301 of the intermediate transfer device 30 so that the photosensitive drum 21 is intermediately transferred. The belt 31 contacts the belt 31 at an accurate position. As a result, during the above-described image formation, the toner images formed on the photosensitive drums 21 of the respective detachable units 20 (Y, M, C, K) are transferred to the intermediate transfer belt 31 in a normal primary transfer position. Will come to be.

  Furthermore, when the side plate 201A is displaced in the direction E1 approaching the intermediate transfer device 30 by the above operation of the operation lever 50, the detachable unit 20 at this time is detachable unit 20 side as shown in FIGS. The fitting projection 81 as the erroneous mounting preventing means in FIG. 5 is displaced upward from the fitting groove 85 as the erroneous mounting preventing means on the mounting portion 13 side. That is, the fitting projection 81 on the detachable unit 20 side is released from the fitting state with the fitting groove 85 on the mounting portion 13 side. FIG. 44 shows a state in which the operation lever 50 of the black (K) detachable unit 20 is in a tilted state and the above-described positioning is not performed.

  As a result, the developing device 24 adopting the swing support structure in the detachable unit 20 is released from the restriction by the erroneous mounting preventing means (81, 85) at the stage where the mounting is completed, and the above-described swinging device 24 is released. The dynamic support structure functions normally. That is, the developing device 24 is maintained in a state that can swing in the directions indicated by the arrows H1 and H2, for example. At this time, the portion of the developing device 24 in the detachable unit 20 is also released from the guide by the guide portion 75 in the mounting portion 13 and the restriction by the restriction portion 304 as the third guide portion as described above. .

Then, as shown in FIGS. 18, 43, 47, etc., the detachable unit 20 attached to the attachment portion 13 has a coil spring at the displacement bottom 53 at which the operation lever 50 is located at the upstream end in the insertion direction D1. Since the reaction force (F1) is received from the fixed surface portion 135 of the mounting portion 13 due to the spring force F1 of 67, the end portion (side plate 201A) is elastic so as to be displaced in the direction E1 approaching the intermediate transfer device 30. Pressed against.
Thereby, the state in which the photosensitive drum 21 in the detachable unit 20 is in contact with the intermediate transfer belt 31 is stably held. At this time, the detachable unit 20 has an angle θ1 with the reference horizontal plane SH that is substantially zero (θ1≈0).

State of the exposure apparatus when the detachable unit is mounted Further, in the image forming apparatus 1, when the detachable unit 20 is mounted on the mounting section 13, the mounting section is linked with the movement when the detachable unit 20 is mounted. 13 is in a state (positioned state) in which the exposure device 23 attached to 13 approaches the photosensitive drum 21 in the detachable unit 20.

  That is, as described above, the detachable unit 20 is inserted into the mounting portion 13 to which the exposure apparatus 23 is attached (FIG. 30). Thus, as shown in FIG. 45 and the like, the guide accommodating portion 204 on the side plate 201A on the end portion on the upstream side in the insertion direction D1 of the detachable unit 20 is the end on the upstream side in the insertion direction D1 in the exposure apparatus 23. Approach the part. On the other hand, the lower end portion of the leaf spring 274 of the guided portion 27 at the upstream end portion of the exposure apparatus 23 (actually, the inclined introduction surface portion 274a) is formed on the bottom surface 204b as the guiding portion 28 of the guiding housing portion 204. Touch the edge. At this time, the attachment / detachment unit 20 has been checked for the erroneous attachment preventing means described above, and the shaft portion 214 of the photosensitive drum 21 is in a state where it is started to be fitted into the holding hole 16 in the holding portion 15.

  Subsequently, the detachable unit 20 is further moved in the insertion direction D1 and inserted until the insertion is completed. Thus, as shown in FIG. 46 and the like, the inclined introduction surface portion 274a as the guided portion 27 of the leaf spring 274 on the exposure apparatus 23 side rides on the edge portion of the bottom surface 204b of the guide accommodating portion 204 and proceeds. As a result, the enclosure frame 271, the swinging member 272, and a part of the leaf spring 274 and the positioning contact member 273 constituting the guided portion 27 are all the internal space of the guide accommodating portion 204 on the detachable unit 20 side. It will be in the state where it was guided and stored.

  At this time, the introduction surface portion 274a of the leaf spring 274 on the exposure device 23 side proceeds so as to ride over the edge portion of the bottom surface 204b of the guide accommodating portion 204. As a result, the end of the light emitting structure 230 on the upstream side in the insertion direction D1 of the exposure apparatus 23 receives a force in the upward direction via the leaf spring 274 and the swing member 272, so that the exposure apparatus 23 supports the support structure. The fulcrum member 239 of the portion 232 is displaced in the direction M1 approaching the photosensitive drum 21 around the fulcrum member 239. In addition, when the introduction surface portion 274a of the leaf spring 274 is completely in contact with the bottom surface 204b of the guide accommodating portion 204, the optical member 233 of the light emitting structure 230 in the exposure device 23 is spaced from the photosensitive drum 21 by a substantially required distance S. It becomes a state.

  Subsequently, the positioning unit 20 is swung in the direction J1 in which the operation lever 50 is raised in order to position the mounting / demounting unit 20 in the mounting portion 13. As a result, as shown in FIG. 47 and the like, the side plate 201A of the detachable unit 20 is displaced in the direction E1 approaching the intermediate transfer device 30 by the action of the lever of the operation lever 50. Displace similarly. As a result, the leaf spring 274 is lifted upward by the bottom surface portion 204b in the internal space of the guide housing portion 204, so that the installation surface portion 274b of the leaf spring 274 comes into contact with the bottom surface portion 204b, and positioning is performed. The upper surface portion of the contact member 273 comes into contact with the contact receiving surface 204 a of the guide housing portion 204.

  In this way, the exposure device 23 (the light emitting structure 230) attached in advance to the mounting portion 13 side is linked to the movement when the detachable unit 20 is mounted on the mounting portion 13, and the photosensitive drum in the detachable unit 20 is attached. 21 (FIGS. 47, 48, etc.).

At this time, the end portion (the guide accommodating portion 204 of the side plate 201A) on the upstream side in the insertion direction D1 in the light emitting structure portion 230 of the exposure apparatus 23 applies the spring force F2 by the plate spring 274 in the guided portion 27 to the contact member 273. (FIG. 47). As a result, the end of the light emitting structure 230 of the exposure device 23 is pressed in the direction M1 approaching the photosensitive drum 21, and the distance S between the light emitting structure 230 (optical component 233) and the photosensitive drum 21 is reached. (Corresponding to the focal length) is held stably.
Further, the upper surface portion of the contact member 273 in the guided portion 27 on the exposure apparatus 23 side comes into surface contact with the contact receiving surface 204a in the upper portion of the guide accommodating portion 204 on the detachable unit 20 side (FIG. 47). As a result, vibration is synchronized between the photosensitive drum 21 and the light emitting structure 230, and fluctuations in the focal distance between the light emitting structure 230 and the photosensitive drum 21 are suppressed.

  In this image forming apparatus 1, the upstream end portion in the insertion direction D 1 of the detachable unit 20 is displaced in the direction E 1 approaching the intermediate transfer belt 31 by the swinging operation of the operation lever 50 and positioned. At this time, the shaft portion 214 of the photosensitive drum 21 in the detachable unit 20 is slightly displaced in the holding hole 16 of the holding portion 15 with the contact portion with the pressing member 18 as a fulcrum.

In this case, the pressing member 18 in the holding hole 16 has the pressing surface 182 in the insertion direction D1 as described above when the shaft portion 214 of the photosensitive drum 21 is fitted in the holding hole 16 of the holding portion 15 in the housing placement portion 151a. As shown in FIG. 49, the state of being displaced so as to incline in the direction P toward the upstream side of the image (FIG. 41) is interlocked with the displacement of the image forming unit 20 (photosensitive drum 21) in the approaching direction E1. Thus, it is displaced so as to be returned to the downstream side in the insertion direction D1 (θ4≈0), and finally the pressing surface 182 (especially the second end surface portion 182b) is substantially the same as the upper surface portion 16a of the holding hole 16. It returns to the state of facing each other in parallel.
Thereby, even if the shaft portion 214 of the photosensitive drum 21 in the image forming unit 20 when the positioning is completed is slightly displaced in the holding hole 16 due to the displacement in the approaching direction E1, the pressing in the holding hole 16 is performed. When the member 16 is displaced in conjunction with each other, the normal state held in the holding hole 16 is maintained. Accordingly, the shaft portion 214 of the photosensitive drum 21 at this time appropriately receives the spring force F3 of the coil spring 19 by the pressing member 18 in the holding hole 16 and moves in the direction N1 approaching the upper surface portion 16a of the holding hole 16. The normal state of being elastically pressed is also maintained.

  Next, the removal of the detachable unit 20 (Y, M, C, K) from the mounting portion 13 is performed by advancing the above-described mounting operation in the reverse order.

◎ Positioning release stage at the time of detachment First, as shown in FIGS. 16, 46, etc., the operation lever 50 in each detachable unit 20 (Y, M, C, K) is swung in the direction J2 to be lowered. Let By the swinging operation of the operation lever 50 in the tilting direction J2, the displacement bottom 53 is released from the contact state with the fixed surface portion 135 in the mounting portion 13 and is brought into a non-contact state, so that the entire operation lever 50 is in a sideways state. Become.

As a result, the detachable unit 20 has an end that is downstream in the extraction direction D2 (upstream in the insertion direction D1) while the shaft portion 214 of the photosensitive drum 21 is held in the holding hole 16 of the holding portion 15. Since the portion (side plate 201A) does not receive the force lifted by the swinging operation in the direction J2 in which the operation lever 50 is tilted, it is displaced so as to move in the direction E2 away from the intermediate transfer device 30 by its own weight.
As a result, the photosensitive drum 21 in the detachable unit 20 is in a state where the downstream end portion in the extraction direction D2 is separated from the intermediate transfer belt 31 of the intermediate transfer device 30. As a result, the detachable unit 20 is in a state in which the entire photosensitive drum 21 is inclined and separated from the intermediate transfer belt 31, so that an extraction operation is possible.

At this time, the light emitting structure 230 of the exposure apparatus 23 is held by holding the contact member 273 and the like constituting the guided portion 27 in the guide receiving portion 204 of the detachable unit 20, and is spaced from the photosensitive drum 21. S also remains retained.
Further, at the end of the detachable unit 20 on the upstream side in the extraction direction D2 (downstream side in the insertion direction D1), the downstream end in the extraction direction D2 of the detachable unit 20 (upstream / downstream end in the insertion direction D1). With the displacement in the direction E2 away from the intermediate transfer belt 31, the pressing member 18 is displaced in the holding hole 16 of the holding portion 15 that holds the shaft portion 214 of the photosensitive drum 21 as follows. That is, the pressing member 18 at that time is displaced so as to sink in the direction 2 away from the upper surface portion 16a of the holding hole 16 in response to the load at the time of contact with the shaft portion 214, and the pressing surface 18a is inserted in the insertion direction D1. It is displaced so as to incline in the direction P toward the upstream side (FIG. 41). Thereby, even when the detachable unit 20 is taken out, the shaft portion 214 of the photosensitive drum 21 can be smoothly extracted without receiving an external force such as unnecessary frictional resistance from the holding hole 16 of the holding portion 15. The extraction operation of the detachable unit 20 is also performed smoothly.

Extraction stage at the time of removal Subsequently, the detachable unit 20 is pulled out from the mounting portion 13 along the extraction direction D2. At the time of this extraction, the shaft portion 214 of the photosensitive drum 21 in the attachment / detachment unit 20 is extracted from the holding hole 16 of the holding portion 15 in the attachment portion 15, and the attachment protrusion 205 of the side plate 201 </ b> B in the attachment / detachment unit 20 It is extracted from the mounting hole 17 (FIG. 34).

However, the first guided portion 71 on the attachment / detachment unit 20 side is a first portion on the mounting portion 15 side slightly before the shaft portion 214 of the photosensitive drum 21 is removed from the holding hole 16 of the holding portion 15. While starting to be fitted into the guide portion 75, the protruding end portion 246 of the developing device 24 on the detachable unit 20 side starts to contact the third guide portion 304 as a restricting portion on the mounting portion 13 side (FIGS. 28 and 28). 29). Thereby, the detachable unit 20 starts to receive guidance (and regulation) by the first guide part 75 and the third guide part 304.
In addition, the second guided portion 73 on the detachable unit 20 side is also released from the guidance of the second guide portion 77B on the mounting portion 13 side, while being fitted into the other second guide portion 77A. Start (FIG. 28). Thereby, the detachable unit 20 starts to receive guidance by the second guide portion 77B.

The state of the exposure apparatus when the detachable unit is removed Further, when the detachable unit 20 is taken out, the light emitting structure 230 of the exposure apparatus 23 is guided and accommodated by the contact member 273 constituting the guided part 27 and the like. It will be in the state which slipped out from the inside of the part 204 (FIG. 45, FIG. 46). As a result, the light emitting structure 230 has an end on the upstream side in the extraction direction D2 that is not supported by the guide accommodating portion 204 and naturally falls downward due to its own weight, and in the support structure 232, the photosensitive drum centering on the fulcrum member 239. It swings so as to move in a direction M2 away from 21. As a result, the light emitting structure 230 is finally in a state where the distance from the photosensitive drum 21 is widened.

Therefore, when the detachable unit 20 is pulled out, it is surely avoided that the photosensitive drum 21 comes into contact with the intermediate transfer belt 31 or the light emitting structure 230 of the exposure device 23, and the drawing operation is performed. The photosensitive drum 21, the intermediate transfer belt 31, the exposure device 23, and the like are not likely to be damaged by contact.
Further, the exposure device 23 (the light emitting structure 230) on the mounting unit 13 side is separated from the photosensitive drum 21 in the detachable unit 20 in conjunction with the movement when the detachable unit 20 is removed from the mounting unit 13. The state is switched (FIG. 45).

[Other embodiments]
In the actual form 1, the protrusion 87 is provided on the pressing member 18 of the holding unit 15 and the recess 214b is provided on the shaft 214 of the photosensitive drum 21 in the detachable unit 20. However, other examples include, for example, holding A depression may be provided in the pressing member 18 of the portion 15, and a protrusion that fits into the depression may be provided on the shaft portion 214 of the photosensitive drum 21 in the detachable unit 20.

  Further, the detachable unit 20 is not limited to the configuration example shown in the first embodiment, and may be a detachable unit having only the photosensitive drum 21, for example.

  In addition, in the first exemplary embodiment, the configuration example in which the four detachable units 20 (Y, M, C, and K) are detachably mounted as the image forming apparatus 1 has been illustrated. It may be one that attaches a plurality of detachable units or one that attaches a single detachable unit.

DESCRIPTION OF SYMBOLS 1 ... Image forming apparatus 10 ... Housing | casing 13 ... Mounting part 15 ... Holding part (an example of a holding member)
DESCRIPTION OF SYMBOLS 16 ... Holding hole 16a ... Upper surface part 18 ... Pressing member 20 ... Detaching unit 151 ... Accommodating arrangement part 182 ... Pressing surface 182a ... 1st edge part surface part (At least upstream edge part of an insertion direction among pressing surfaces)
182c ... inclined surface 187 ... protrusion (an example of protrusion)
187a ... Inclined surface 214 ... Shaft (an example of the downstream end of the detachable unit)
214b ... depression (an example of a depression)
D1 ... Insertion direction D2 ... Extraction direction N1 ... Direction approaching the upper surface of the holding hole N2 ... Direction separating from the upper surface of the holding hole SH ... Reference horizontal plane (reference horizontal plane)
θ1 ... Angle (An angle when tilting upward with respect to the reference horizontal plane)
P: Direction toward the upstream side of the insertion direction

Claims (5)

A housing having a mounting portion;
Inserted into and removed from the mounting portion of the housing along the insertion direction that is inclined upward with respect to a reference horizontal plane, and is attached to and removed from the mounting portion. A detachable unit in which a portion is lifted and held in a posture parallel to the horizontal plane;
A holding member having a holding hole that is disposed at an end portion on the downstream side in the insertion direction of the mounting portion of the housing and is held by being fitted with a downstream end portion in the insertion direction of the detachable unit;
A pressing member that is attached to the holding member and has a pressing surface that elastically presses the downstream end of the detachable unit fitted into the holding hole toward the upper surface of the holding hole from below;
With
The pressing member can be displaced with respect to the holding member in a direction approaching and separating from the upper surface portion of the holding hole, and can be displaced so that the pressing surface is inclined in a direction toward the upstream side in the insertion direction. The attached image forming apparatus. The holding member has an accommodation arrangement part in which the pressing member is accommodated and arranged at a lower part of the holding hole,
The image forming apparatus according to claim 1, wherein the pressing member is attached to the holding member in a state where there is a gap with respect to the housing arrangement portion.   3. The image according to claim 1, wherein the pressing member is formed in a shape including an inclined surface that is inclined so that at least an upstream side in the insertion direction of the pressing surface is along the insertion direction. 4. Forming equipment.   A protrusion is provided on the pressing member, and a depression in which the protrusion of the pressing member is fitted is provided at a downstream end of the detachable unit, or a depression is provided in the pressing member, and the detachment unit is provided on the downstream side. The image forming apparatus according to claim 1, wherein a protrusion that fits into a depression of the pressing member is provided at an end portion. A protrusion is provided on the pressing surface of the pressing member, and a recess in which the protrusion of the pressing member is fitted is provided at an end of the detachable unit,
The image forming apparatus according to claim 3, wherein the protrusion on the pressing surface of the pressing member has an inclined surface in which a portion on the upstream side in the insertion direction is continuous with the inclined surface on the pressing surface.

Images