JP2008064999A - Image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To enable easy mounting of an addition unit into an opening/closing cover. <P>SOLUTION: An image forming apparatus (U) has an opening/closing cover (U2) opened and closed around a center of rotation (U2a), central side supporting sections (6, 7) arranged on the center of rotation (U2a) side, and fixing sections (11, 12) arranged on a side distant from the center of rotation (U2a), and comprises an addition unit supporting member (2) opened during opening of the opening/closing cover (U2), and fixed sections (32b, 33b) fixed via a fixing member (51) to the fixing sections (11, 12). The apparatus includes the addition unit (U14) which is supported in the addition unit supporting member (2) and adds a function to the image forming apparatus (U). <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

The present invention relates to an image forming apparatus such as a printer, a FAX, a copying machine, or a multifunction machine having all or a plurality of functions, and in particular, an image forming that can be equipped with an additional unit (optional unit) that adds functions to the image forming apparatus. Relates to the device.

In the conventional electrophotographic image forming apparatus, the functions (print function, standard paper feed tray, standard paper discharge tray, etc.) that are provided as standard in the apparatus are built in the image forming apparatus main body, and the duplex printing function and paper Post-processing functions such as alignment, stapler, punch hole formation, and additional paper feed trays and paper discharge trays may be provided as additional functions (options) in an additional unit or a separate unit.
Such an additional unit is widely installed on the side or outside of the image forming apparatus (see, for example, Patent Document 1 (Japanese Patent Laid-Open No. 2002-258564)).
There is a problem that the size of the entire image forming apparatus is increased, and the installation area and the exclusive area are increased. Also, when supporting on the side of the image forming apparatus like a double-sided printing unit, the center of gravity position of the entire image forming apparatus changes, the balance is lost, the image quality deteriorates due to twisting, etc., and a frame is used to prevent twisting. There is a problem that measures to be strengthened are necessary.

In order to cope with such a problem, the following conventional technique (J01) is conventionally known as a technique for supporting the additional unit inside the image forming apparatus.
(J01) Technology described in Patent Document 2 (Japanese Patent Laid-Open No. 2001-235905) Patent Document 2 describes a space in which an additional unit for double-sided printing can be accommodated between a side cover that can be opened and closed and an image forming apparatus main body. In a state in which the side cover is opened and an additional unit having a sheet reversing path and a sheet conveying roll unit for double-sided printing is inserted and mounted from above, that is, the additional unit inside the image forming apparatus Techniques that support the above are described. Reference 2 also describes that the side cover is configured to be detachable and the side cover is also attached and detached when the unit is mounted.

Japanese Patent Laid-Open No. 2002-258564 (FIGS. 3, 7, and 8) JP 2001-235905 A ("0029" to "0033", FIGS. 1 to 3)

(Problems of conventional technology)
In the prior art (J01), there is no specific description of how to mount the additional unit to the image forming apparatus main body, and it is unclear how it is fixed. Normally, when an additional unit is attached to the image forming apparatus main body, a service engineer, not a user, may attach it. However, calling the service engineer causes a problem that communication, waiting time, and labor costs increase. However, when the user installs an additional unit in the image forming apparatus, there are mounting methods such as removing the cover as in the prior art (J01) or mounting using various screws. If it is complicated, there is a problem that it is difficult to mount. Further, when the additional unit is accommodated inside the opening / closing cover, the opening / closing cover may become an obstacle to the operation when the additional unit is attached / detached, and there is a problem that the mounting operation becomes difficult.

In view of the above circumstances, the present invention has the following description (O01) as a technical problem.
(O01) To make it possible to easily mount an additional unit inside the opening / closing cover.

Next, the present invention that solves the above problems will be described. In order to facilitate correspondence with the constituent elements of the embodiments described later, the constituent elements of the present invention are enclosed in parentheses. I will add that.
The reason why the present invention is described in correspondence with the reference numerals of the embodiments described later is to facilitate the understanding of the present invention, and not to limit the scope of the present invention to the embodiments.

(First invention)
In order to solve the technical problem, the image forming apparatus (U) of the first invention is:
An open / close cover (U2) that is opened and closed around the rotation center (U2a);
A center side support (6, 7) disposed on the rotation center (U2a) side, and the rotation center (U
2a) and a fixing portion (11, 12) disposed on the side far from the open / close cover (U2).
An additional unit support member (2) that is opened when the
A supported part (32a, 33a) disposed on the rotation center (U2a) side and supported by the center side supporting part (6, 7), and a fixing member (51) through the fixing part (11, 12). And an additional unit (32b, 33b, 32b ′, 33b ′) that is fixed to the image forming apparatus (U) by being supported by the additional unit support member (2). U4)
It is provided with.

(Operation of the first invention)
In the image forming apparatus (U) according to the first aspect of the present invention having the above-described structural requirements, the open / close cover (U2) is opened / closed around the rotation center (U2a). When the opening / closing cover (U2) is opened, the additional unit support member (2) is opened. The supported parts (32a, 33a) of the additional unit (U4) that adds functions to the image forming apparatus (U) are arranged on the rotation center (U2a) side, and the rotation center (U2a) of the additional unit support member (2). It is supported by the center side support part (6, 7) arranged on the side. The fixed part (32b, 33b, 32b ′, 33b ′) of the additional unit (U4)
Fixed part (11) of the additional unit support member (2) disposed on the side far from the rotation center (U2a)
, 12) through a fixing member (51). As a result, the additional unit (U4)
It is fixed to the additional unit support member (2).
Therefore, in the image forming apparatus (U) of the first invention, when the additional unit (U4) is supported by the additional unit support member (2), it is supported on the side close to the rotation center (U2a) of the open / close cover (U2). , Fixed on the side far from the center of rotation (U2a). Therefore, the opening / closing cover (
When the U2) is opened and the additional unit (U4) is attached to and detached from the inside of the image forming apparatus (U), it is possible to reduce the obstruction of the opening / closing cover (U2) and to make the additional unit (U4) easy. Can be installed.

(First Embodiment 1)
The image forming apparatus (U) according to the first aspect of the present invention is the first invention, wherein
The open / close cover (U2) having a side cover (U2d) that covers the side of the main body of the image forming apparatus (U) and an upper surface cover (U2e) that covers a part of the upper surface of the main body of the image forming apparatus (U). ),
It is provided with.
(Operation of Form 1 of the First Invention)
In the image forming apparatus (U) according to the first aspect of the present invention having the above-described structural requirements, the opening / closing cover (
U2) includes a side cover portion (U2d) that covers the side surface of the main body of the image forming apparatus (U), and an upper surface cover portion (U2e) that covers a part of the upper surface of the main body of the image forming apparatus (U).
Therefore, by opening the opening / closing cover (U2), not only the side surface of the image forming apparatus (U) but also a part of the upper surface can be opened, and the opening / closing cover (U2) does not interfere with the additional unit (U4).
) Can be installed.

(First Embodiment 2)
The image forming apparatus (U) according to the second aspect of the first invention is the image forming apparatus (U) according to the first invention or the first aspect of the first invention.
The fixing portions (11, 12) disposed at a position equal to or higher than the height of the upper end of the side cover portion (U2d) in a state in which the opening / closing cover (U2) is opened;
It is provided with.
(Operation of the second aspect of the first invention)
In the image forming apparatus (U) according to the second aspect of the present invention having the above-described structural requirements, the fixing portion (11
, 12) is arranged at a position higher than the height of the upper end of the side cover part (U2d) with the open / close cover (U2) open, so that the open / close cover (U2) does not get in the way, The fixing work by the fixing member (51) can be easily performed.

(Embodiment 3 of the first invention)
An image forming apparatus (U) according to a third aspect of the first invention is the image forming apparatus (U) according to any one of the first and first aspects of the present invention.
A transport unit having an additional transport path (SH2) for transporting the recording sheet (S) transported from the main body of the image forming apparatus (U) and an additional transport member (Ra) for transporting the recording sheet (S). The additional unit (U4) configured by (U4),
It is provided with.
(Operation of the third aspect of the first invention)
In the image forming apparatus (U) according to the third aspect of the first invention having the above constituent elements, an additional unit (U
4) includes an additional conveyance path (SH2) for conveying the recording sheet (S) conveyed from the main body of the image forming apparatus (U), an additional conveyance member (Ra) for conveying the recording sheet (S), It is comprised by the conveyance unit (U4) which has. Therefore, when adding the recording sheet (S) conveyance function, the additional unit (U4) can be easily mounted.

(First aspect 4)
An image forming apparatus (U) according to a fourth aspect of the first invention is the same as that according to the third aspect of the first invention.
The recording sheet (S) conveyed from the main body of the image forming apparatus (U) is transferred to the image forming apparatus (U
) The additional unit (U4) having the additional conveyance path (SH2) constituted by the sheet reversing path (SH2) returning to the main body,
It is provided with.
(Operation of the fourth aspect of the first invention)
In the image forming apparatus (U) according to the fourth aspect of the first invention having the above constituent elements, an additional unit (U
4) The additional conveyance path (SH2) configured by a sheet reversing path (SH2) for returning the recording sheet (S) conveyed from the main body of the image forming apparatus (U) to the main body of the image forming apparatus (U).
Have. Therefore, an additional unit having a sheet reversing path (SH2) for duplex printing (SH2)
U4) can be easily mounted.

(First embodiment 5)
An image forming apparatus (U) according to a fifth aspect of the first invention is any one of the first invention and the first to fourth aspects of the first invention.
The additional unit support member having the fixing part (11, 12) constituted by a key hole (
2) and
The key-shaped fixing member (51) engaged with the keyhole;
The additional unit (U4) is moved by the fixing member (51) to the additional unit support member (
2) the fixed portions (32b, 33b, 32b ′, 33b ′) that are rotatably supported between a fixed position fixed to 2) and a fixed release position where the fixing is released;
It is provided with.

(Operation of the fifth aspect of the first invention)
In the image forming apparatus (U) according to the fifth aspect of the first invention having the above-described structural requirements, the fixing portions (11, 12) of the additional unit support member (2) are configured by key holes. The key-shaped fixing member (51) engages with the key hole. The fixed parts (32b, 33b, 32b ', 33
b ′) is rotatable between a fixing position where the additional unit (U4) is fixed to the additional unit support member (2) and a fixing release position where the fixing is released by the fixing member (51). To support. Therefore, since the additional unit (U4) can be fixed to the additional unit support member (2) by rotating the fixing member (51) between the fixing position and the fixing release position, it can be easily attached and detached. .

(First Embodiment 6)
An image forming apparatus (U) according to a sixth aspect of the first invention is the fifth aspect of the first invention, wherein
A pair of said fixed part (32b, 33b) arrange | positioned at the both ends of the said additional unit (U4)
, 32b ', 33b') and one end-side fixed portions (32b, 32b) having one end-side guide portions (46c + 46f, 46c ') for guiding the fixing member (51) in a predetermined rotational direction.
′) And the one end side guide portion (46c + 46f, 46c ′) and the other end side fixed portion having the other end side guide portion (49c + 49f, 49c ′) for guiding the fixing member (51) in the reverse rotation direction. (33b, 33b ′) and a pair of the fixed parts (32b, 33b, 32)
b ', 33b'),
It is provided with.

(Operation of the sixth aspect of the first invention)
In the image forming apparatus (U) according to the sixth aspect of the first invention having the above-described structural requirements, the pair of fixed parts (32b, 33b, 32b ′, 33b) disposed at both ends of the additional unit (U4).
′) Is one end side fixed portion (32b, 32b ′) and the other end side fixed portion (33b, 33b ′).
And have. One end side guide part (46c + 46f,) of the one end side fixed part (32b, 32b ')
46c ′) guides the fixing member (51) in a predetermined rotational direction. Fixed part at the other end (
The other end side guide portions (49c + 49f, 49c ') of 33b, 33b') guide the fixing member (51) in the direction opposite to the one end side guide portions (46c + 46f, 46c '). Accordingly, since the rotation direction is opposite between the one end side and the other end side, when the fixing member (51) is operated simultaneously on the one end side and the other end side, it becomes a natural ergonomic operation (if the rotation direction is the same, the body The fixing member (51) can be easily rotated and fixed.

(First embodiment 7)
An image forming apparatus (U) according to a seventh aspect of the first invention is the fifth or sixth aspect of the first invention, wherein
The fixed part having a through hole (45, 48) through which the fixing member (51) passes and an arcuate guide surface (46a1, 49a1) formed on the outer peripheral part of the through hole (45, 48) ( 3
2b, 33b, 32b ', 33b'),
The fixed part (32b, 33b, 32b ', 33b') and the fixed part (11, 12)
) Penetrating through the shaft portion (52), and the keyhole-shaped fixing portion (11, 11) formed in the shaft portion (52).
12) a key portion (56) that engages and locks, and the fixed portion (32b, 33b, 32b ′).
, 33b '), the fixed member (51) having a bearing portion (57) that contacts the guide surfaces (46a1, 49a1) and is guided when the fixing member (51) rotates,
It is provided with.

(Operation of the first aspect 7)
The image forming apparatus (U) according to the seventh aspect of the present invention having the above-described structural requirements is provided with the fixed portion (32
b, 33b, 32b ', 33b') are passed through the through holes (45, 48) by the fixing member (51). Arc-shaped guide surfaces (46a1, 49a1) are formed on the outer periphery of the through holes (45, 48). The supported part (57) is connected to the fixed part (32b, 33b, 32b ′, 33).
It contacts the guide surface (46a1, 49a1) of b ') and is guided when the fixing member (51) rotates. The shaft portion (52) of the fixing member (51) is connected to the fixed portion (32b, 33b, 32).
b ', 33b') and the fixing part (11, 12). The key portion (56) formed on the shaft portion (52) of the fixing member (51) engages and locks with the keyhole-shaped fixing portion (11, 12). Accordingly, the fixed member (51) has the bearing portion (57) having the guide surface (46a).
1, 49a1) is rotated by being guided by the key portion (56), and the additional unit (U4) can be fixed to the additional unit support member (2).

(Embodiment 8 of the first invention)
The image forming apparatus (U) according to the eighth aspect of the first invention is the seventh aspect of the first invention, wherein
The fixed portion (32b, having a protrusion (46d, 46e, 49d, 49e) formed on the guide member and formed at a position corresponding to the fixed position and the fixed release position.
33b, 32b ', 33b'),
As the fixing member (51) rotates, the protrusions (46d, 46e, 49d, 49e)
The protrusion engaging elastic deformation part (58) which is engaged and elastically deformed and then released and elastically restored.
The fixing member (51) having:
It is provided with.
(Operation of the eighth aspect of the first invention)
In the image forming apparatus (U) according to the eighth aspect of the first invention having the above-described structural requirements, the protrusion engaging elastic deformation portion (58) is fixed in position and released as the fixing member (51) rotates. After engaging with the protrusions (46d, 46e, 49d, 49e) formed at the position corresponding to the position and elastically deforming, the engagement is released and elastic recovery is performed. Accordingly, the elastic deformation and elastic restoration of the protrusion engaging elastic deformation portion (58) conveys the sensation to the operator who holds the fixing member (51) at the fixing position and the fixing release position and operates the fixing member (51). The operator can sensuously recognize that the fixing member (51) has moved to the fixing position or the fixing release position.

The above-described present invention has the following effect (E01).
(E01) An additional unit can be easily mounted inside the opening / closing cover.

Next, specific examples (examples) of the embodiments of the present invention will be described with reference to the drawings, but the present invention is not limited to the following examples.
In order to facilitate understanding of the following description, in the drawings, the front-rear direction is the X-axis direction, the left-right direction is the Y-axis direction, the up-down direction is the Z-axis direction, and arrows X, -X, Y, -Y, The direction indicated by Z and -Z or the indicated side is defined as front, rear, right, left, upper, lower, or front, rear, right, left, upper, and lower, respectively.
In the figure, “•” in “○” means an arrow heading from the back of the page to the front, and “×” in “○” is the front of the page. It means an arrow pointing from the back to the back.
In the following description using the drawings, illustrations other than members necessary for the description are omitted as appropriate for easy understanding.

1 is a perspective explanatory view of an image forming apparatus according to a first embodiment of the present invention.
In FIG. 1, in a printer U as an image forming apparatus according to a first embodiment of the present invention, a discharge tray TRh is provided on the upper surface of the printer body U1, and a recording sheet S on which an image is recorded is accommodated in the lower portion of the printer body U1. The sheet cassette TR1 to be used is accommodated. The printer body U1
Includes a front cover (open / close cover) U2 that is rotatably supported between a normal position (see a solid line in FIG. 1) and an open position (see a broken line in FIG. 1) around the front rotation center U2a. The front cover U2 rotates the front cover U2 to the open position by pushing the cover open / close button U2b or pushing the rotary frame open / close section U2c upward from the bottom when a paper jam occurs. Thus, the sheet conveyance path (SH, SH2) can be opened to eliminate the paper jam. Members opened and closed by the cover opening / closing button U2b and the rotating frame opening / closing portion U2c will be described later.
In FIG. 1, a front cover U2 according to the first embodiment includes a front cover portion (side cover portion) U2d of the printer U that extends in the vertical direction, and extends rearward from the upper end of the front cover portion U2d.
And an upper cover portion (upper surface cover portion) U2e that covers a part of the upper surface of the device and supports the user interface UI.
Further, a top cover (opening / closing member) U3 that is opened and closed when replacing an internal replaceable member (toner cartridge or the like) is provided at the upper rear side of the printer body U1.
Is supported so as to be rotatable around.

FIG. 2 is an explanatory diagram of the image forming apparatus according to the first embodiment.
In FIG. 2, the printer main body U1 has a controller C constituted by a microcomputer, an IPS (image processing system) whose operation is controlled by the controller C, a laser drive circuit DL, a power supply device E, and the like. The power supply device E applies a bias voltage to a charging roller CR, a developing roller GR, a transfer roller (T1, T2b) and the like which will be described later.
The IPS (image processing system) converts print data input from an external host computer or the like into image data for forming a latent image and outputs it to the laser drive circuit DL at a predetermined timing. The laser drive circuit DL outputs a laser drive signal to the latent image forming device ROS (optical scanning device) according to the input image data. The ROS emits a laser beam (image writing light) L for image writing in accordance with a laser drive signal.

The rotationally driven image carrier (rotating member) PR disposed above the ROS is uniformly charged by the charging roll CR and then the ROS (latent image forming apparatus) at the latent image writing position Q1. ) Is exposed and scanned by the laser beam L to form an electrostatic latent image. When forming a full-color image, electrostatic latent images corresponding to four color images of K (black), Y (yellow), M (magenta), and C (cyan) are sequentially formed. Only the electrostatic latent image corresponding to the (black) image is formed.
The surface of the image carrier PR on which the electrostatic latent image is formed rotates and moves sequentially through the development area Q2 and the primary transfer area Q3.

A rotary developing device G is arranged above the ROS. The rotary type developing device G sequentially rotates and moves to the developing area Q2 as the rotation axis Ga rotates.
, Y (yellow), M (magenta), C (cyan) four color developing devices GK, GY, GM, G
C. The developing devices GK, GY, GM, GC of the respective colors have developing rolls GRk, GRy, GRm, GRc that convey the developer to the developing area Q2, and are on the image carrier PR that passes through the developing area Q2. The electrostatic latent image is developed into a toner image.
The developing containers of the developing units GK, GY, GM, and GC are configured to be supplied with toner of each color from toner replenishing cartridges TCk, TCy, TCm, and TCc, respectively. Such a rotary developing device is known in the art (for example, Japanese Patent Laid-Open No. 12-13194).
2, refer to Japanese Patent Laid-Open No. 12-231250, etc.), and detailed description thereof is omitted.

An intermediate transfer belt B wound around the image carrier PR is disposed in front of the image carrier PR. The intermediate transfer belt B includes a plurality of driven rolls Rj, a wrap-in roll Rw1 disposed at a winding start position, a primary bias roll (primary transfer roll) T1 to which a primary transfer bias is applied, and a winding end position. Belt support rolls (Rj, Rw1, Rw2, T1, T) including a wrap-out roll Rw2 and a backup roll T2a
2a) is rotatably supported. During the image forming operation, the intermediate transfer belt B rotates in the direction of the arrow Yb following the rotationally driven image carrier PR.

When forming a full-color image, an electrostatic latent image of the first color is formed at the latent image writing position Q1, and a toner image of the first color is formed in the development region Q2. When this toner image passes through the primary transfer region Q3 between the wrap-in roll Rw1 and the wrap-out roll Rw2,
The primary transfer is electrostatically performed on the intermediate transfer belt B by the primary bias roll T1. Thereafter, similarly, the second, third, and fourth color toner images are sequentially superimposed and transferred onto the intermediate transfer belt B carrying the first color toner image in order, and finally, full-color multiplexing is performed. A toner image is formed on the intermediate transfer belt B.
In the case of forming a monochromatic monochromatic image, only one developing device is used, and the monochromatic toner image is primarily transferred onto the intermediate transfer belt B.
After the primary transfer, residual toner remaining on the surface of the image carrier PR is cleaned by the image carrier cleaner CL1.

At a position facing the backup roll T2a, a secondary transfer roll T2b is arranged so as to be movable between a position separated from the backup roll T2a and a position in contact with a separation / contact device (not shown). . The backup roll T2a and the secondary transfer roll T2b constitute a secondary transfer device T2. A secondary transfer region Q4 is formed by a contact region between the backup roll T2a and the secondary transfer roll T2b.
The secondary transfer roll T2b has a polarity 2 opposite to the charging polarity of the toner used in the developing device G.
The next transfer voltage is supplied from the power supply circuit E, and the power supply circuit E is controlled by the controller C.

A paper feed tray TR1 that accommodates the recording sheet S is disposed below the printer body U1, and the recording sheet S in the paper feed tray TR1 is placed on the pickup roll Rp by the sheet placement plate TR1a. It is held at the paper feed position that touches it. Feed tray TR
The recording sheets S accommodated in 1 are taken out by a pick-up roll Rp at a predetermined timing, separated one by one by a separating roll Rs having a feed roll Rs1 and a retard roll Rs2, and are conveyed by a conveying roll Ra in the sheet conveying path SH. It is conveyed to the registration roll Rr. The recording sheet S set in the manual paper feed tray TR0 is conveyed to the registration roll Rr by the manual paper feed roll Rp0. The recording sheet S conveyed to the registration roll Rr is subjected to the secondary transfer from the pre-transfer sheet guide SG1 at the timing when the primary transferred multiple toner image or single color toner image moves to the secondary transfer area Q4. Transported to region Q4.
In the secondary transfer area Q4, the secondary transfer unit T2 electrostatically secondary-transfers the toner image on the intermediate transfer belt B onto the recording sheet S. The residual toner is removed from the intermediate transfer belt B after the secondary transfer by the belt cleaner CL2.

The secondary transfer roll T2b and the belt cleaner CL2 are disposed so as to be separated from (contacted with and separated from) the intermediate transfer belt B. When a color image is formed, an unfixed toner image of the final color is formed. Is separated from the intermediate transfer belt B until it is primarily transferred to the intermediate transfer belt B.
A toner image forming apparatus that forms a toner image by transferring the toner image onto the recording sheet S by the image carrier PR, the charging roll CR, the developing device G, the primary transfer roll T1, the intermediate transfer belt B, the secondary transfer device T2, and the like. PR + CR + G + T1 + B + T2).

The recording sheet S on which the toner image is secondarily transferred is conveyed to a fixing region Q5 configured by a region (nip) where the heating roll Fh and the pressure roll Fp of the fixing device F are in pressure contact with each other. The recording sheet S passing through the fixing area Q5 is heated and fixed by the fixing device F. The recording sheet S on which the toner image has been heat-fixed is conveyed to a sheet discharge roll Rh, and is discharged from a sheet discharge port Ka formed at the upper end of the image forming apparatus U1 to a discharge tray TRh.
At the time of duplex printing, the registration roll Rr is switched back by the sheet discharge roll Rh, conveyed through the sheet reversing path (additional conveying path) SH2, and the recording sheet S is reversed.
Resent to The sheet reversing path SH2 according to the first exemplary embodiment is formed inside the image forming apparatus U when the reversing unit (additional unit, transport unit) U4 is mounted, and the upstream reversing path SH2a on the upstream side in the reversing path transport direction and the middle stream A side inversion path SH2b and a downstream inversion path SH2c are provided.

(Explanation of frame and cover and opening / closing mechanism)
(Description of fixed frame)
FIG. 3 is an explanatory view showing a state in which only the opening / closing cover (front cover) of the first embodiment is moved to the open position.
FIG. 4 is a side view of FIG.
FIG. 5 is an explanatory diagram of a state in which the opening / closing cover and the rotating frame of the first embodiment are moved to the open position.
FIG. 6 is an enlarged explanatory view of a main part of the cover opening / closing mechanism that opens only the opening / closing cover, and is a view illustrating a state in which a part of the opening / closing cover is omitted and the cover opening / closing mechanism is moved to the openable position.
FIG. 7 is an enlarged view of a main part of a rotating frame opening / closing mechanism that opens and closes the opening / closing cover and the rotating frame.
3 to 7, an image forming apparatus U according to the first exemplary embodiment has a fixed frame 1 that supports a developing device G, an intermediate transfer belt B, and the like, and the fixed frame 1 centered on a position that is substantially the same as the rotation center U2a. The rotary frame 2 is rotatably supported and supports the secondary transfer roll T2b, the fixing device F, the manual paper feed roll Rp0, and the like. In FIG. 7, the fixed frame 1
On both left and right end surfaces (only the right end surface side is shown in FIG. 7), there are formed rotating frame locking projections 1a protruding outward.

(Description of rotating frame)
FIG. 8 is a perspective view of a main part in a state where the reversing unit is mounted on the rotating frame of the first embodiment.
FIG. 9 is an explanatory perspective view of a main part in a state where the reversing unit is removed from the state of FIG.
FIG. 10 is an enlarged view of the main part of the upper right part of the rotating frame.
FIG. 11 is an enlarged view of the main part of the upper left portion of the rotating frame.
8 and 9, the rotating frame 2 is fixed to the fixed frame 1 with a rotation center 2a (FIG. 8,
In FIG. 9, it is supported so as to be rotatable about the right side only). The rotating frame 2
At the lower part of the front end surface of the downstream side inner guide part 3 which is an inner side guide of the downstream side reversing path SH2c.
Is formed. A unit mounting recess 4 in which the reversing unit U4 is mounted is formed in the upper part of the downstream side inner guide portion 3, and the unit mounting recess 4 and the opening / closing cover U2 are provided.
A unit mounting space is formed by a space surrounded by the inner surface of the unit.
In FIG. 9, a right side unit support portion (center side support portion, hook portion) 6 having a U-groove shape in a side view is formed at the right end portion of the downstream side inner guide portion 3. 9 and 11, a left side unit support portion (center side support portion, hook portion) 7 having a U-groove shape in a side view is formed at the left end portion of the downstream side inner guide portion 3.

9 to 11, the upper right end portion of the rotating frame 2 has a keyhole-shaped right-side fixing portion 11 (a fixing portion, see FIGS. 9 and 10) having a circular hole and a square hole extending vertically from the circular hole. ), And a left-side fixing portion 12 (a fixing portion, see FIGS. 9 and 11) having a keyhole shape similar to the right-side fixing portion 11 is formed at the upper left end portion of the rotating frame 2.
6, 8, 9, and 10, a right cover lock portion 13 having a lock member guide portion 13 a and a lock hole 13 b is formed on the upper left side of the right fixing portion 11.
Similarly, in FIGS. 9 and 11, a left cover lock portion 14 having a lock member guide portion 14 a and a lock hole 14 b is formed on the upper left side of the left fixed portion 12.

3 to 5 and 7, the rotary frame 2 supports a rotary shaft 15 that is penetrated in the front-rear direction so as to be rotatable, and a rotary frame lock member is provided at both left and right ends of the rotary shaft 15. 16, 17 are supported. The rotary frame lock members 16 and 17 have rear arm portions 16b and 17b, and engage with the rotary frame lock projections 1a of the fixed frame 1 on the upper ends of the rear arm portions 16b and 17b. Claw portions 16c and 17c are formed. Closed guide surfaces 16c1 and 17c1 are formed on the rear upper portions of the claw portions 16c and 17c. The rotary frame lock members 16 and 17 are respectively connected to the front arm portion 16.
d (the left front arm portion 17d is not shown). Between the front arm portion 16d and the pin 2b formed on the rotating frame 2 below the front arm portion 16d, a spring 1 is provided.
8 is installed. An engaged portion 17e (FIG. 7) that engages with a rotary frame opening / closing portion U2c (see FIG. 1) of the front cover U2 is provided at the front end portion of the left rotating frame lock member 17.
Reference) is formed.

(Description of front cover)
In FIG. 6, a pair of left and right pins 21 (only the right side is shown in FIG. 6) projecting inward from the front cover U2 is provided on the upper inner surface of the front cover U2. An extending slide bar 22 is supported by a pair of pins 21 so as to be slidable in the left-right direction.
The slide bar 22 has a button engaging portion 22a extending rearward from the right end portion, and the inner end portion of the cover opening / closing button U2b disposed on the right side portion of the front cover U2 is included in the button engaging portion 22a. Is engaged. The cover lock portion 1 is provided at both ends of the slide bar 22.
Corresponding to 3 and 14, a pair of left and right cover lock members 23 (only the right side is shown in FIG. 6) are fixedly supported. The cover lock member 23 is configured by a long hole extending in the left-right direction, and has a guided portion 23a through which the pin 21 passes and is guided so as to be slidable in the left-right direction. Further, the cover lock member 23 has a triangular prism-shaped lock portion 23b that penetrates the slide bar 22 and protrudes backward. The lock portion 23b is connected to the lock holes 13b, 14
a fitting portion 23c that can be fitted to b and hold the front cover U2 on the rotary frame 2, and a rear (
And a guide surface 23d that inclines from the outside toward the inside as it goes in the (X direction).
The slide bar 22 is formed with a pair of left and right spring mounting holes 24 (shown only on the right side in FIG. 6) and a spring accommodating port 26 in the inner portion of the cover lock member 23.
A spring 27 is accommodated in the spring accommodating port 26. One end of the spring 27 is supported by the spring mounting hole 24, and the other end is supported by a spring support portion of the front cover U2 (not shown).

Accordingly, during the normal image forming operation, the front cover U2 is held (locked) on the rotary frame 2 by the cover lock member 23 and the cover lock portions 13 and 14, and the rotary frame 2 is 17 and the rotating frame locking projection 1a are held (locked) on the fixed frame 1.
When the reversing unit U4 is attached / detached or when a paper jam occurs in the sheet reversing path SH2, the slide bar 22 is slid by pressing the cover opening / closing button U2b, and the cover lock member 23 and the lock member guide portions 13, 14 are moved. The engagement is released and only the front cover U2 moves from the closed position to the open position (see FIGS. 1, 3, and 4). Cover open / close button U2b
When the user (or a service engineer or an operator at the manufacturing site) releases his / her finger, the spring 27 returns the slide bar 22 to its original state. When the front cover U2 is returned from the open position to the closed position in this state, the guide surface 23d of the cover lock member 23 is guided by interfering with the front end surfaces of the lock member guide portions 13 and 14, and the slide bar 22 is once moved to the left ( Move to the open position side. When the front cover U2 is further pushed in from this state and the fitting portion 23c of the cover lock member 23 passes through the front end face, the fitting portion 23c moves to the right by the force of the spring 27, and the fitting portion 23c is moved to the lock member guide portions 13,14. Is engaged and locked.

On the other hand, when a paper jam occurs in the sheet conveyance path SH, the front arm portion of the left rotary frame lock member 17 is moved upward by operating the rotary frame opening / closing portion U2c of the front cover U2 to be pushed upward from below. And the left and right rotary frame lock members 16 and 17 are rotated from the rotary frame lock position (see the solid line in FIG. 7) to the rotary frame lock release position (see the broken line in FIG. 7). Then, when the engagement between the claw portions 16 c and 17 c and the rotating frame locking protrusion 1 a of the fixed frame 1 is released, the rotating frame 2 becomes rotatable with respect to the fixed frame 1. At this time, since the front cover U2 and the rotary frame 2 are locked by the cover lock member 23 and the lock member guide portions 13 and 14, the front cover U2 and the rotary frame 2 are integrally moved from the closed position (see FIG. 1). It can be moved to the open position (see FIGS. 1 and 5). The left rotating frame locking member 17 is not shown in the figure, which engages with the left cover locking member 23 when the rotating frame locking member 17 moves to the unlocked position, thereby restricting the movement of the cover locking member 23. A slide restricting portion is provided so that the slide bar 22 cannot slide while the rotary frame opening / closing portion U2c is being pressed.

In a state where the rotary frame opening / closing part U2c is not operated (a state in which the user releases his / her hand), the rotary frame lock members 16 and 17 are moved to the rotary frame lock position by the spring 18. In this state, when the front cover U2 is returned to its original position, the rotating frame locking projection 1
When the claw portions 16c and 17c are closed, the guide surfaces 16c1 and 17c1 come into contact with and are guided to the open position side. However, when the front cover U2 is further pushed, the claw portions 16c and 17
c reaches the rotating frame locking projection 1a, and the spring 18 engages the claw portions 16c,
17c and the rotating frame locking projection 1a are engaged and locked. In addition, the rotary frame 2 and the front cover U2 provided with such an opening / closing mechanism are conventionally known, and various configurations can be employed.

(Description of reversing unit (additional unit))
FIG. 12 is a perspective explanatory view of a reversing unit as Embodiment 1 of the additional unit of the present invention.
8 and 12, a reversing unit U4 as an additional unit is supported in the unit mounting space on the front side of the rotating frame 2. The reversing unit U4 includes a guide portion 31 extending in the vertical direction, end wall portions 32 and 33 formed integrally with the left and right ends of the guide portion 31, and the end wall portion 32 disposed above the guide portion 31 and the end wall portion 32. , 33 rotatably supported on the upstream side guide member 34, a motor unit M supported on the upper end of the left end wall 32,
A connector CN is connected to a connector (not shown) of the rotating frame 2 and performs input / output of control signals, power supply, and the like. Therefore, the reversing unit U4 according to the first embodiment is formed in an inverted L shape as a whole by the guide portion 31 extending in the vertical direction and the upstream guide member 34 extending rearward.

On the front surface of the guide portion 31, a middle flow inner guide portion 31 a that extends in the vertical direction and forms a middle flow inner guide surface of the sheet reversing path SH <b> 2 is formed. In addition, a pair of left and right driven roller support holes 31b, 31c, 31d, and 31e are formed in the upper end portion and the lower end portion of the guide portion 31, respectively. Each driven roller support hole 31b, 31c, 31d, 31e has a transport roller (
The additional roller Ra) is driven by a driven roller Ra1 (only two lower rollers are shown in FIG. 12).
Is supported in a state of being urged outward by. A paper sensor 37 is supported at the center of the guide portion 31 and is used for detecting a paper jam by contacting the recording sheet S being conveyed.
Above the middle flow inner guide portion 31, the upstream guide member 34 is connected to the upstream inner guide surface 34 a that is continuous from the middle flow inner guide portion 31 a and is curved backward to form the upstream sheet reversing path SH 2 a and the upstream side. An outer guide surface 34b (see FIG. 2) is formed.

Between the both end wall portions 32, 33, two rotating shafts 41, 4 crossing the front side of the guide portion 31.
2 is supported. A driving roller Ra2 facing the driven roller Ra1 is supported on each of the rotary shafts 41 and 42, and the driven roller Ra1 is in contact with the driving roller Ra2 with a predetermined contact pressure by the spring 36. A gear train 43 is disposed on the left end wall portion 32, and the drive from the motor box M is transmitted to the rotary shafts 41 and 42 via the gear train 43, so that the transport roller Ra (the drive roller Ra1 and the driven roller) is transmitted. Ra2) is driven to rotate.
8 and 12, the lower end portions of the both end wall portions 32 and 33 have arc-shaped lower end surfaces, and are supported by the unit support portions 6 and 7 (see FIG. 9) having a U-groove shape in a side view. Supported portions (hanging supported portions) 32a and 33a are formed.
A left fixed portion 32b that protrudes to the left is formed at the center in the vertical direction of the left end wall portion 32, and a right fixed portion 33b that protrudes to the right at the center in the vertical direction of the right end wall portion 33. Is formed.

(Explanation of left fixed part)
FIG. 13 is an explanatory view of the main part of the left fixed part and the fixing member.
FIG. 14 is a view as seen from the direction of arrow XIV in FIG.
In FIG. 13, a keyhole-shaped fixing member through hole 45 is formed in the left fixed portion 32 b, and the left fixed portion 32 b protrudes forward corresponding to the keyhole-shaped fixing member through hole 45. A left front protrusion 46 is formed. The left front projecting portion 46 includes a cylindrical left cylindrical portion 46a and a square left key passage portion 4 formed continuously from the right portion of the left cylindrical portion 46a to the right.
6b. A bearing surface (guide surface) 46a1 is constituted by the inner peripheral surface of the left cylindrical portion 46a. The left cylindrical portion 46a is formed with an arc-shaped left fixed member rotation guide portion 46c that protrudes forward from the left portion to the lower portion. The left fixed member rotation guide portion 4
The diameter of the inner peripheral surface of 6c is formed larger than the diameter of the inner peripheral surface of the left cylindrical portion 46a.

Further, a pair of left projections 46d and 46e are formed on the upper front end surface of the left cylindrical portion 46a so as to be separated from each other in the left-right direction, and the left unlocking projection 46d is formed by a projection formed on the right side. The left lock position protrusion 46e is formed by the protrusion formed on the left side. Further, a left-side mounting guide portion 46f having a substantially triangular shape in side view that is inclined forward as it goes upward along the circumferential direction is formed at the upper boundary portion of the left cylindrical portion 46a and the left key passage portion 46b. ing. The left side fixing member rotation guide portion 46c and the left side mounting guide portion 46f constitute the left side guide portion (one end side guide portion) (46c + 46f) of the first embodiment.
A ring-shaped left outer guide surface 46a is provided inside the left fixing member rotation guide portion 46c, the left projections 46d and 46e, the left mounting guide portion 46f, and on the front surface of the left cylindrical portion 46a.
2 is formed.
13 and 14, on the rear side (−X side) of the inner peripheral surface of the left front protrusion 46c,
A left claw engagement portion 46g formed by an arc-shaped step is formed, and a claw engagement surface 46g1 is formed at a step portion between the fixing member through hole 45 and the left claw engagement portion 46g.

(Explanation of right-side fixed part)
FIG. 15 is an explanatory diagram of a main part of the right-side fixed portion and the fixing member according to the first embodiment.
FIG. 16 is an explanatory diagram of a state in which a fixing member is attached to the right-side fixed portion.
15 and 16, the right-side fixed part 33b of the first embodiment includes the left-side fixed part 32.
The fixing member through-hole 45 b is formed symmetrically with the fixing member through-hole 48, and has a right front protruding portion 49 that protrudes forward in a shape corresponding to the fixing member through-hole 48. The right front projecting portion 49 includes a cylindrical right cylindrical portion 49a and a square right key passage portion 49b formed continuously from the left to the left of the right cylindrical portion 49a. A bearing surface (guide surface) 49a1 is constituted by the inner peripheral surface of the right cylindrical portion 49a. The right front protruding portion 49 is formed with an arc-shaped right fixing member rotation guide portion 49c that protrudes forward from the left portion to the lower portion. The diameter of the inner peripheral surface of the right fixed member rotation guide portion 49c is formed larger than the diameter of the inner peripheral surface of the right cylindrical portion 46a.

Also, a pair of left projections 49d and 49e are formed on the upper front end surface of the right cylindrical portion 49a so as to be separated from each other in the vertical direction, and the right unlock position projection 49d is constituted by the projections formed above. The right lock position projection 49e is configured by the projection formed below. Further, on the upper left side of the right unlocking position protrusion 49d, a right mounting guide portion 49f having a substantially triangular shape in side view is formed, which is inclined forward as it goes rightward along the circumferential direction. The right side fixing member rotation guide part 49c and the right side mounting guide part 49f constitute the right side guide part (the other end side guide part) (49c + 49f) of the first embodiment.
A ring-shaped right outer guide surface 49a is provided inside the right fixing member rotation guide portion 49c, the right projections 49d and 49e, and the right mounting guide portion 49f and on the front surface of the right cylindrical portion 49a.
2 is formed.
15 and 16, on the rear side (−X side) of the inner peripheral surface of the right front protrusion 49c,
A right claw engagement portion 49g formed by an arc-shaped step is formed, and a claw engagement surface 49g1 is formed at a step portion between the fixing member through hole 45 and the right claw engagement portion 49g.

(Description of fixing member)
FIG. 17 is a perspective explanatory view of the fixing member of the first embodiment.
18 is a view as seen from the direction of arrow XVIII in FIG.
13 to 18, the fixing member 51 according to the first embodiment is integrally formed of resin, and has a cylindrical shaft portion 52 and a disc-like shape formed at the base end portion of the shaft portion 52. Guided portion 53
And a plate-like operation part 54 that is continuous with the guided part 53 and can be operated by a user by pinching with a finger.
And have.
A key portion 56 extending from the shaft portion 52 to both sides in the radial direction (radial direction) is formed at the tip end portion (front end portion in the fixing member mounting direction) of the cylindrical shaft portion 52, and the key portion 56 of the first embodiment is formed. The shaft portion 52
Is formed at the same position as the operation portion 54 in the rotation direction. The key portion 56 includes a keyhole-shaped right side fixing portion 11 and left side fixing portion 12 (FIGS. 9 to 11).
It is formed so that it may fit (see).

The shaft portion 52 on the base end side (the rear end side in the fixing member mounting direction) of the key portion 56 is formed with a bearing portion 57 extending from the shaft portion 52 to both sides in the radial direction (radial direction). The shaft-supported portion 57 is formed at a position where the phase in the rotational direction advances about 45 ° in the clockwise direction with respect to the operation portion 54 when the shaft portion 52 is viewed from the front side (+ X side) of the apparatus as the central axis. ing. Further, the bearing portion 57 is set so that the outer end portion is guided in contact with the bearing surfaces 46a1 and 49a1 of the fixed portions 32b and 33b (see FIG. 18).
The shaft portion 52 on the base end side of the bearing portion 57 includes a plate-like clutch portion (protrusion engaging elastic deformation portion) 58 extending in the radial direction (radial direction) from the shaft portion 52, and the opposite side of the clutch portion 58. An extended outer guided portion 59 (see FIGS. 13 to 15) is formed. The clutch portion 58 and the outer guided portion 59 are formed in the same position as the bearing portion 57 in the rotational direction.

In FIG. 17, since the clutch portion 58 is made of resin, the distal end portion can be elastically deformed along the axial direction of the shaft portion 52, and a protrusion is formed on the surface of the clutch portion 58 on the distal end side of the shaft portion 52. The protrusion engaging part 58a comprised by these is formed. The clutch portion 58 is guided in the rotational direction in a state in which the protrusion engaging portion 58a of the protrusion is locked to the front end surface of the cylindrical portion 46a,
Depending on the rotational position, the projections 46d, 46e, 49d, 49e and the mounting guide portions 46f, 49
It is formed to be engageable with f. Further, the outer guided portion 59 has a bearing portion 5 on the tip side.
7 is formed so as to be guided in the rotational direction while being in contact with and locked to the outer guide surfaces 46a2 and 49a2.

In FIG. 17, the disk-shaped guided portion 53 is formed with a pair of retaining portions 61 extending along the shaft portion 52 toward the distal end side of the shaft portion. The retaining portion 61 is formed at a position where the phase in the rotational direction moves about 45 ° in the counterclockwise direction with respect to the operation portion 54 when the shaft portion 52 is viewed from the front side (+ X side) of the apparatus as the central axis. Has been. The retaining portion 61
A guide surface 61a at the time of mounting formed so that the thickness thereof becomes thinner toward the tip portion.
When the fixing member 51 is attached to each of the fixed portions 32b and 33b, a claw portion 61b that is hooked on the claw engaging surface 49g1 is formed. Further, on the base end side of the retaining portion 61, the outer guide surfaces 46a2 and 49a are provided when the fixing member 51 is mounted on the fixed portions 32b and 33b.
2 is formed with an outer retaining portion 61c that is guided in the rotational direction while being in contact with and locked to the second portion.

FIG. 19 is an explanatory diagram of a state in which the fixing member of Example 1 has been moved to the mounting position where it is mounted on the additional unit, and FIG. 19A is a diagram of the state in which the left fixed portion is viewed from the inside of the guided portion on the front side. FIG. 19B is an explanatory diagram of a state where the left fixed part is viewed from the rear side, FIG. 19C is a main part sectional view of the right fixed part viewed from the inside of the guided part on the front side, and FIG. It is explanatory drawing of the state which looked at the right side fixed part from the rear side.
FIG. 20 is an explanatory diagram of a state in which the fixing member of Example 1 has moved to the unlocked position (fixed release position), and FIG. 20A is a diagram of the left-side fixed part viewed from the inside of the guided part on the front side. FIG. 20B is an explanatory diagram of a state where the left fixed part is viewed from the rear side, FIG. 20C is a main part sectional view of the right fixed part viewed from the inside of the guided part on the front side, and FIG. It is explanatory drawing of the state which looked at the right side fixed part from the rear side.
FIG. 21 is an explanatory diagram of a state in which the fixing member of Example 1 has moved to the lock position (fixed position), and FIG. 21A is a cross-sectional view of the main part in a state in which the left fixed portion is viewed from the inside of the guided portion on the front side. Fig. 2
1B is an explanatory view of the left fixed part as viewed from the rear side, FIG. 21C is a main part sectional view of the right fixed part as viewed from the inside of the guided part on the front side, and FIG. 21D is the right fixed part. FIG. 21E is a cross-sectional view taken along line XXIE-XXIE in FIG. 21A.

In FIG. 19, when the fixing member 51 is attached to the fixed portions 32b and 33b of the reversing unit U4, the fixing member 51 is fixed to the fixing member through hole 45 with the key portion 56 corresponding to the key passage portions 46b and 49b. , 48. Next, when the fixing member 51 is pushed back,
When the retaining portion 61 is mounted, the guide surface 61a comes into contact with the front end surfaces of the cylindrical portions 46a and 49a, and the retaining portion 61 is elastically deformed inward. Further, the fixing member 51 is pushed back, and the claw portion 61 is pressed.
When b is pushed to the position of the claw engaging surfaces 46g1 and 49g1, the retaining member 61 returns to the original state by the elastic restoring force, and the claw portion 61b engages with the claw engaging surfaces 46g1 and 49g1 to prevent the retaining. (See FIG. 18). Accordingly, the fixing member 51 moves to the mounting position shown in FIG. At this time, the clutch portion 58 is located between the fixed member rotation guide portions 46c and 49c and the mounting guide portions 46f and 49f.
At the mounting position, the fixing member 51 can be removed by elastically deforming so as to release the engagement of the claw portion 61b.

19 and 20, when the user pinches the operation portion 54 and rotates the clutch portion 58 so as to move toward the attachment guide portions 46f and 49f with the fixing member 51 attached, the bearing portion 57 On the bearing surfaces 46a1 and 49a1, the guided portion 53 on the fixed member rotation guide portions 46c and 49c, the claw portion 61b on the claw engaging surfaces 46g1 and 49g1, and the clutch portion 58 on the front end surfaces of the cylindrical portions 46a and 49a. The outer retaining portion 61c is provided on the outer guide surfaces 46a2 and 49a2.
Are guided in contact with each other. When the clutch portion 58 reaches the inclined surfaces of the substantially triangular mounting guide portions 46f and 49f, the movement of the fixing member 51 along the axial direction (mounting direction) is performed by the claw portion 61b and the outer retaining portion 61c. Since it is regulated, the clutch portion 58 that contacts the mounting guide portions 46f and 49f is elastically deformed to the front side (+ X side).

When the fixing member 51 is further rotated from this state, the clutch portion 58 is attached to the mounting guide portion 4.
Overcoming 6f and 49f, it returns to its original state from the elastically deformed state. As a result, the fixing member 5
1 moves to the unlock position (fixed release position, see FIG. 20). When the fixing member 51 is moved to the unlock position, the rotation is restricted by the vertical surfaces of the mounting guide portions 46f and 49f even if the fixing member 51 is rotated to return to the mounting position side. I can't go back to it. On the contrary, even if the fixing member 51 tries to rotate in a state where the user does not operate, the protrusion engaging portion 58a of the clutch portion engages with the protrusion 46d for unlock position, and the opposite side to the mounting position (the lock described later) Rotation to the position side) is also restricted. Therefore, the fixing member 51 is stably held at the unlock position. At the unlock position, the key portion 56
Can not pass through the fixing member through-holes 45 and 48, so the fixing member 51 cannot be removed from the reversing unit U4.
It is possible to prevent the fixing member 51 from being detached from the reversing unit U4. Therefore, Example 1
When only the unit is stored in the warehouse or the like, the reversing unit U4 can be held in the unlocked position after the fixing member 51 is mounted.

20 and 21, when the user pinches the operation portion 54 and rotates the fixing member 51 in a direction in which the fixing member 51 can be rotated from the unlock position (a direction opposite to the mounting position), the protrusion engaging portion 58 a of the clutch portion 58. Engages with the unlock position protrusion 46d. When further rotated in this state, the clutch portion 58 is elastically deformed, the protrusion engaging portion 58a gets over the unlock position protrusion 46d, and the fixing member 51 rotates. When further rotated, the protrusion engaging portion 58a engages with the lock position protrusion 46e. When further rotated from this state, the clutch portion 58 is elastically deformed, the protrusion engaging portion 58a gets over the lock position protrusion 46e, and the fixing member 51 moves to the lock position (fixed position) shown in FIG. Therefore, to the user who operates the operation unit 54,
A feeling (click feeling) when the protrusion engaging portion 58a gets over the lock position protrusion 46e is transmitted, and the user can sensibly recognize that the protrusion has moved to the lock position.
In addition, when moving from the locked position to the unlocked position, the user can move it by pinching the operating portion 54 and moving it to the unlocked position side. At this time, the protrusion engaging portion 58a also moves the unlocked position protrusion 46d. You can recognize that you have moved to the unlock position as if you were getting over.
As a result, once the fixing member 51 mounted at the mounting position moves to the unlock position,
It is rotatably supported between the unlock position and the lock position.

(Operation of Example 1)
In the printer (image forming apparatus) U of Embodiment 1 having the above-described configuration, when the reversing unit U4 as an additional unit for adding the double-sided printing function is mounted, first, the cover opening / closing button U2b of the front cover U2 is operated. , Move only the front cover U2 to the open position,
Open the unit mounting space. That is, the side surface on which the unit of the rotating frame (additional unit support member) 2 is mounted is opened.
In this state, the supported portions 32a and 33a at the lower end of the reversing unit U4 are attached to the U-shaped unit support portions 6 and 7 (see FIG. 9). Next, the reversing unit U4 is rotated around the U-shaped unit support portions 6 and 7 as the center of rotation, and the fixed portions 32b and 33b are moved to positions facing the fixing portions 11 and 12, respectively. At this time, if the fixing member 51 is moved to the unlock position, the pair of key portions 56 of the fixing member 51 are along the vertical direction, so that the key portion 56 is fixed to the fixing portion 11.
, 12 are fitted through the keyholes.

When the fixing member 51 is rotated from the unlocked position to the locked position in a state where the key part 56 is fitted in the fixing parts 11 and 12, the key part 56 is rotated to 90 ° with respect to the key holes of the fixing parts 11 and 12.
Since it moves to the rotated position, it is locked (see FIG. 21E). As a result, the reversing unit U4 is fixed to the rotating frame 2. Then, the reversing unit U4 is accommodated in the printer U by moving the front cover U2 to the closed position.
Further, when removing the reversing unit U4 from the rotating frame 2, the fixing member 51 is moved to the unlocked position, and then the reversing unit U4 is rotated around the U-shaped unit support portions 6 and 7 to thereby fix the fixing member. It can be removed by removing 51 from the keyholes 11 and 12.

Therefore, in the printer U according to the first embodiment, when the additional unit U4 is mounted, the supported portions 32a and 33a disposed on the side closer to the rotation center U2a of the front cover U2 are hooked and far from the rotation center U2a. Since the fixed portions 32b and 33b are fixed on the side, there is little work on the rotation center U2a side where the work space is narrow, and the fixing work is performed on the fixing member 51 on the side farther from the rotation center U2a where the work space is relatively wide. It can be performed. Therefore, the additional unit U4 can be easily attached to the printer U, and workability is improved. Further, the supported portion 32a,
Since 33a is only supported by the U-shaped unit support portions 6 and 7, and does not need to be fixed with screws or the like, there are few places to fix and the workability is high. Furthermore, since the mounting can be performed simply by rotating the fixing member 51 and a tool such as a screwdriver necessary for screwing is not required, the mounting operation can be facilitated. For this reason, even without calling a service engineer or the like, the user can easily attach or replace the reversing unit U4, and the waiting time or labor costs can be suppressed.

Further, in the printer U according to the first embodiment, as illustrated in FIG. 4, when the front cover U <b> 2 is moved to the open position, the upper end portion of the front cover U <b> 2 (the upper end portion of the upper cover portion U <b> 2 e) Since the height is set to be substantially the same as the height in the direction, the work space for operating the fixing member 51 is wider than when the upper end portion of the front cover U2 is disposed above the fixing member 51, and the user can Since it is not necessary to put the hand all the way in, the fixing work can be easily performed.
Further, in the printer U according to the first embodiment, the same fixing member 51 can be used for the fixed portions 32b and 33b at the left and right ends, so that the parts can be shared and the cost can be reduced.

Further, in the reversing unit U4 of the first embodiment, when the fixing member 51 is rotationally moved between the unlock position and the lock position, the rotation direction (clockwise and counterclockwise) differs between the right side and the left side. When both are rotated in the same direction, the body is tilted ergonomically and it becomes difficult to operate, but in the reversing unit U4 of Example 1 that rotates in different rotation directions, the operation becomes ergonomically natural. The force can be easily applied, and the fixing work can be easily performed.
Further, in the printer U according to the first embodiment, the bearing portion 57, the guided portion 53, the claw portion 61b, the clutch portion 58, and the outer retaining portion 61c provided on the fixing member 51 are fixed portions 32b and 3b.
3b bearing surfaces 46a1 and 49a1, fixed member rotation guide portions 46c and 49c, claw engaging surface 46
g1, 49g1, the front end surfaces of the cylindrical portions 46a and 49a are guided by the outer guide surfaces 46a2 and 49a2, so that when the fixing member 51 is rotated, the fixing member 51 does not wobble and the shaft portion 52 is reliably used as the rotation axis. Can be rotated.

Further, in the printer U according to the first embodiment, the fixing member 51 can be held in the locked position or the unlocked position by the engagement between the protrusion engaging portion 58a and the protrusions 46d and 46e, and the user can The movement to the unlock position can be recognized with a click feeling, and the possibility of being left at the intermediate position can be reduced.
Further, in the first embodiment, when the fixing member 51 is attached to the reversing unit U4 and moved to the unlock position, it cannot be removed in principle. Therefore, when the reversing unit U4 is attached or removed, the fixing member 51 falls off. Can be prevented.

FIG. 22 is a perspective explanatory view of the right fixed part of the second embodiment of the present invention.
FIG. 23 is an explanatory diagram of a state in which a fixing member is attached to a fixed portion on the right side of the second embodiment.
FIG. 24 is a perspective explanatory view of a fixed portion on the left side of the second embodiment.
FIG. 25 is an explanatory diagram of a state in which a fixing member is attached to the left fixed portion of the second embodiment.
Next, a printer (image forming apparatus) U according to a second embodiment of the present invention will be described. In the description of the second embodiment, components corresponding to the components of the first embodiment are denoted by the same reference numerals. Detailed description thereof will be omitted. This Example 2 is different from Example 1 in the following points,
In other respects, the configuration is the same as in the first embodiment.

22 and 23, in the right-side fixed portion 33b ′ of the second embodiment, the right-side mounting guide portion 49f is omitted compared to the right-side fixed portion 33b of the first embodiment. In the right-side fixed portion 33b 'of the second embodiment, the right-side fixing member rotation guide portion (the other end side guide portion) 49c'
A portion corresponding to the position where the right-side mounting guide portion 49f is formed is formed.
FIG. In FIG. 25, the left fixed portion 32b ′ of the second embodiment is also the right fixed portion 33b ′.
Similarly, the left mounting guide portion 46f is omitted, and the left fixing member rotation guide portion (one end side guide portion) 46c 'is formed up to the portion corresponding to the position where the left mounting guide portion 46f was formed. .

(Operation of Example 2)
In the printer U of the second embodiment having the above-described configuration, each fixed portion 32 is compared to the case of the first embodiment.
Parts corresponding to the mounting positions when the fixing member 51 is mounted on b ′ and 33b ′ are omitted. Therefore, the fixing member 51 cannot be mounted from the axial direction of the shaft portion 52, but after the fixing member 51 is inserted obliquely with respect to the axial direction and the key portion 56 passes through the key passage portions 46b and 49b, The fixing member 51 can be attached to the fixed portions 32b ′ and 33b ′ by rotating the unlocking member while moving the fixing member 51 along the axial direction.
Therefore, the fixing member 51 of the second embodiment mounted on the reversing unit U4 in this way moves the fixing member rotation guide portions 46c 'and 49 when moving between the unlocking position and the locking position.
Since the arc length of c ′ is longer than that in the case of the first embodiment, the area where the guided portion 53 contacts is widened, and stable with less wobbling than in the case of the first embodiment. Can be rotated. In addition, the reversing unit U4 of the second embodiment has the same functions and effects as those of the first embodiment.

(Example of change)
As mentioned above, although the Example of this invention was explained in full detail, this invention is not limited to the said Example, A various change is performed within the range of the summary of this invention described in the claim. It is possible. Modification examples (H01) to (H08) of the present invention are exemplified below.
(H01) In the above-described embodiment, the printer as the image forming apparatus has been exemplified. However, the present invention is not limited to this, and a FAX, a copying machine, or a multifunction machine having all or a plurality of functions may be used. Further, the image forming apparatus is not limited to a color image forming apparatus, and may be configured by a monochrome image forming apparatus. The present invention is not limited to a so-called rotary image forming apparatus, and can be applied to an image forming apparatus such as a tandem type. is there.

(H02) In the above embodiment, the reversing unit is exemplified as the additional unit. However, the present invention is not limited to this, and the present invention can be applied to an additional unit fixed inside the image forming apparatus. For example, when the manual feed tray TR0 is an option, it can be applied to a manual feed tray unit as an additional unit. In addition, the present invention can also be applied to a configuration in which a transport unit for transporting paper to the post-processing apparatus can be added and mounted.
(H03) In the above-described embodiment, the fixed portions 11 and 12 and the fixed portions 32b and 33b are provided as a pair on the left and right sides. However, the present invention is not limited to this, and the number may be one or three or more. . Similarly, the unit support portions 6 and 7 and the supported portions (hanging supported portions) 32a and 33a are not limited to two on the left and right, and may be one or three or more.
(H04) In the above-described embodiment, the fixing member 51 is shared. However, the fixing member 51 is not limited to this, and a plurality of fixing members can be used.

(H05) In the above embodiment, the rotation direction of the fixing member 51 is set in the opposite direction so as to be mirror-symmetrical on the right side and the left side. However, the rotation direction is not limited to this and can be the same rotation direction. It is also possible to change the angle on the right and left sides.
(H06) In the above-described embodiment, the protrusions 46d, 46e, 49d, and 49e and the protrusion engaging portion 58a of the ridge generated a click feeling at the locked position and the unlocked position, but the combination and shape are arbitrary. For example, a concave portion and a protrusion can be used.
It can be omitted.
(H07) In the above-described embodiment, the configuration in which the reversing unit as the additional unit is mounted on the rotating frame is exemplified, but the present invention is not limited to this, and an additional unit mounted on the fixed frame may be used.

(H08) In the above embodiment, the fixing member 51 is made of a resin material. However, the fixing member 51 is not limited to this, and may be made of any material. Moreover, although the shaft part 52, the key part 56, the bearing part 57, etc. were integrally formed, it is not limited to this, It is also possible to produce combining several members. Further, the retaining member 61 and the clutch portion 58 of the fixing member are made of an integral resin material that can be elastically deformed, but any configuration such as a configuration in which a spring and a plate are combined can be adopted.

1 is a perspective explanatory view of an image forming apparatus according to a first embodiment of the present invention. FIG. 2 is an explanatory diagram of the image forming apparatus according to the first embodiment. FIG. 3 is an explanatory view showing a state in which only the opening / closing cover (front cover) of the first embodiment is moved to the open position. FIG. 4 is a side view of FIG. FIG. 5 is an explanatory diagram of a state in which the opening / closing cover and the rotating frame of the first embodiment are moved to the open position. FIG. 6 is an enlarged explanatory view of a main part of the cover opening / closing mechanism that opens only the opening / closing cover, and is a view illustrating a state in which a part of the opening / closing cover is omitted and the cover opening / closing mechanism is moved to the openable position. FIG. 7 is an enlarged view of a main part of a rotating frame opening / closing mechanism that opens and closes the opening / closing cover and the rotating frame. FIG. 8 is a perspective view of a main part in a state where the reversing unit is mounted on the rotating frame of the first embodiment. FIG. 9 is a perspective explanatory view of a main part in a state where the reversing unit is removed from the state of FIG. FIG. 10 is an enlarged view of the main part of the upper right part of the rotating frame. FIG. 11 is an enlarged view of the main part of the upper left portion of the rotating frame. FIG. 12 is a perspective explanatory view of a reversing unit as Embodiment 1 of the additional unit of the present invention. FIG. 13 is an explanatory view of the main part of the left fixed part and the fixing member. FIG. 14 is a view as seen from the direction of arrow XIV in FIG. FIG. 15 is an explanatory diagram of a main part of the right-side fixed part and the fixing member of Example 1. FIG. 16 is an explanatory diagram of a state in which a fixing member is attached to the right-side fixed portion. FIG. 17 is a perspective explanatory view of the fixing member of the first embodiment. 18 is a view as seen from the direction of arrow XVIII in FIG. FIG. 19 is an explanatory diagram of a state in which the fixing member of Example 1 has been moved to the mounting position where it is mounted on the additional unit, and FIG. FIG. 19B is an explanatory diagram of a state where the left fixed part is viewed from the rear side, FIG. 19C is a main part sectional view of the right fixed part viewed from the inside of the guided part on the front side, and FIG. It is explanatory drawing of the state which looked at the right side fixed part from the rear side. FIG. 20 is an explanatory diagram of a state in which the fixing member of Example 1 has moved to the unlocked position (fixed release position), and FIG. 20A is a diagram of the left-side fixed part viewed from the inside of the guided part on the front side. FIG. 20B is an explanatory diagram of a state where the left fixed part is viewed from the rear side, FIG. 20C is a main part sectional view of the right fixed part viewed from the inside of the guided part on the front side, and FIG. It is explanatory drawing of the state which looked at the right side fixed part from the rear side. FIG. 21 is an explanatory diagram of a state in which the fixing member of Example 1 has moved to the lock position (fixed position), and FIG. FIG. 21B is an explanatory diagram of the left fixed part viewed from the rear side, FIG. 21C is a cross-sectional view of the main part of the right fixed part viewed from the inside of the guided part on the front side, and FIG. FIG. 21E is a cross-sectional view taken along line XXIE-XXIE in FIG. FIG. 22 is a perspective explanatory view of the right fixed part of the second embodiment of the present invention. FIG. 23 is an explanatory diagram of a state in which a fixing member is attached to a fixed portion on the right side of the second embodiment. FIG. 24 is a perspective explanatory view of a fixed portion on the left side of the second embodiment. FIG. 25 is an explanatory diagram of a state in which a fixing member is attached to the left fixed portion of the second embodiment.

Explanation of symbols

2 ... Additional unit support member,
6, 7 ... Center side support part,
11, 12 ... fixed part,
32a, 33a ... supported parts,
32b, 32b '... one end side fixed part,
32b, 33b, 32b ', 33b' ... fixed part,
33b, 33b '... other end side fixed part,
45, 48 ... through hole,
46a1, 49a1 ... guide surface,
46c + 46f, 46c '... one end side guide part,
46d, 46e, 49d, 49e ... projections,
49c + 49f, 49c '... the other end side guide part,
51. Fixing member,
52 ... Shaft part,
56 ... Key part,
57: Bearing part,
58 ... projection engaging elastic deformation part,
Ra: Additional conveying member,
S ... Recording sheet,
SH2: Additional conveyance path, sheet reversal path,
U: Image forming apparatus,
U2: Open / close cover,
U2a ... center of rotation,
U2d ... side cover,
U2e ... top cover,
U4: Additional unit, transport unit.

Claims (9)

An opening and closing cover that opens and closes around the center of rotation;
An additional unit support member having a center side support portion disposed on the rotation center side and a fixing portion disposed on a side far from the rotation center, and being opened when the opening / closing cover is opened;
A support portion disposed on the rotation center side and supported by the center side support portion; and a fixed portion fixed to the fixing portion via a fixing member, and supported by the additional unit support member. ,
An additional unit for adding functions to the image forming apparatus;
An image forming apparatus comprising: The open / close cover having a side cover portion that covers a side surface of the image forming apparatus main body and an upper surface cover portion that covers a part of the upper surface of the image forming apparatus main body;
The image forming apparatus according to claim 1, further comprising: The fixing part disposed at a position equal to or higher than the height of the upper end of the side cover part in a state in which the opening / closing cover is opened;
The image forming apparatus according to claim 1, further comprising: The additional unit constituted by a transport unit having an additional transport path through which the recording sheet transported from the image forming apparatus main body is transported, and an additional transport member for transporting the recording sheet;
The image forming apparatus according to claim 1, further comprising: The additional unit having the additional conveyance path configured by a sheet reversing path for returning the recording sheet conveyed from the image forming apparatus main body to the image forming apparatus main body;
The image forming apparatus according to claim 4, further comprising: The additional unit support member having the fixing portion constituted by a key hole;
The key-shaped fixing member engaged with the keyhole;
The fixed portion that is rotatably supported by the fixing member between a fixing position where the additional unit is fixed to the additional unit supporting member and a fixing release position where the fixing is released;
The image forming apparatus according to claim 1, further comprising: A pair of the fixed parts disposed at both ends of the additional unit, the one end-side fixed part having one end-side guide part for guiding the fixing member in a predetermined rotation direction; and the one end-side guide part; A pair of other fixed parts having the other end side fixed part having the other end side guide part for guiding the fixing member in the reverse rotation direction,
The image forming apparatus according to claim 6, further comprising: The fixed part having a through hole through which the fixing member passes, and an arcuate guide surface formed on an outer peripheral part of the through hole;
The fixed portion and a shaft portion that penetrates the fixed portion, a key portion that is formed on the shaft portion and engages and locks with the keyhole-shaped fixing portion, and contacts the guide surface of the fixed portion, The fixed member having a supported portion guided when the fixing member rotates, and
The image forming apparatus according to claim 6 or 7, further comprising: The fixed portion having a protrusion formed on the guide member and formed at a position corresponding to the fixed position and the fixed release position;
With the rotation of the fixing member, the fixing member having a protrusion engaging elastic deformation portion that is elastically deformed by engaging with the protrusion and then being released and elastically restored;
The image forming apparatus according to claim 8, further comprising:

Images