JP2019045850A - Image forming device - Google Patents

Abstract

To prevent the size and weight of an image forming device main body from increasing.SOLUTION: An image forming device comprises a device main body having an image forming section for forming an image on a recording material, a unit detachably attached to the device main body, a switching member rotatably provided at the device main body and selectively switching a path for guiding the recording material in a state of intruding the inside of the unit attached to the device main body, and retreating means provided at the device main body and causing the switching member to retreat outside of an attachment region of the unit in a process of removing the unit from the device main body.SELECTED DRAWING: Figure 14

Description

  The present invention relates to an image forming apparatus such as a copying machine or a printer having a switching member for selectively switching a path for guiding a recording material, and a unit which can be inserted into and removed from the apparatus main body.

  Conventionally, there has been proposed an image forming apparatus such as a copying machine or a printer having a flapper for selectively switching a path for guiding a recording material, and a fixing device which can be inserted into and removed from the apparatus main body. As an image forming apparatus to which the relationship between the flapper of this type and the fixing device that can be inserted and removed is applied, for example, the one described in Patent Document 2 is known. Patent Document 1 describes an image forming apparatus having a fixing device that can be inserted into and removed from the apparatus main body.

  That is, in view of exchangeability and operability at the time of paper jam (at the time of JAM), it is required that the fixing device to be inserted and removed from the image forming apparatus main body and the unit to open and close can be removed without stress.

  The configuration described in Patent Document 2 will be described using FIGS. 17 and 18. As shown in FIGS. 17 and 18, the door 200 is provided to be able to open and close the image forming apparatus. At the time of paper jam processing or replacement of the fixing device, the door 200 is opened as shown by a broken line in FIG. Then, with the opening operation of the door 200, the flapper 202 located on the downstream side of the fixing device 201 in the recording material conveyance direction becomes free from the restriction of the abutment portion 200a of the door 200, and becomes the retracted position. As a result, when the fixing device 201 is inserted and removed, the insertion and removal can be performed without contacting the flapper 202.

JP, 2016-75752, A JP, 2014-130376, A

  On the other hand, for the installation space and energy saving at the time of physical distribution, it is required to reduce the size of the image forming apparatus main body and to reduce the weight of the image forming apparatus main body by simplifying the component configuration.

  However, as described in Patent Document 2, in the case where the flapper 202 is in the retracted position when the door 200 is opened, the butting portion 200a for abutting the flapper 202 on the door 200 is required. In particular, in the case where the flapper is disposed at a deep position of the image forming apparatus main body or the like, the abutment portion also needs to be disposed at the deep position of the image forming apparatus main body.

  That is, in the configuration of Patent Document 2, the turning locus of the door 200 provided with the abutment portion 200a for abutting the flapper 202 becomes large, and the size of the image forming apparatus main body becomes large. In addition, if the link is rotated using a complicated link configuration in order to reduce the rotation path, many parts are required, which results in an increase in the weight of the image forming apparatus.

  An object of the present invention is to suppress an increase in the size and weight of an image forming apparatus main body.

  In order to achieve the above object, according to the present invention, there is provided an apparatus main body having an image forming portion for forming an image on a recording material, a unit removably mounted on the apparatus main body, and the apparatus main body rotatably A switching member for selectively switching a path for guiding a recording material in a state of being provided and entering the inside of the unit mounted on the apparatus main body, and provided on the apparatus main body, the unit being the apparatus main body And evacuating means for evacuating the switching member to the outside of the mounting area of the unit in the process of removing from the housing.

  According to the present invention, it is possible to suppress an increase in the size and weight of the image forming apparatus main body.

Schematic cross-sectional view showing an example of an image forming apparatus Schematic of opening the right door of the image forming apparatus Schematic of fixing device Perspective view of the pressure application mechanism of the fixing device Sectional view of pressure application mechanism of fixing device Perspective view of fixing device Figure of flapper butting component equipped in fixing device Schematic configuration of the insertion and removal mechanism of the fixing device Component parts diagram of the discharge reversing unit of the image forming apparatus Parts diagram of flapper rotation link mechanism of image forming apparatus Component parts diagram of the discharge reversing unit in the process of pulling out the fixing device (A) is a perspective view around the insertion link in a state where the fixing device is mounted, (b) is a perspective view around the insertion link in the process of removing the fixing device Component parts diagram of the discharge reversing unit with the fixing device removed (A), (b) is a figure which shows a mode that a fixing device is inserted in and removed from an apparatus main body. (A)-(c) is a figure which shows the motion of the flapper seen from the apparatus front side (A)-(c) is a figure which shows the movement of the flapper seen from the apparatus back side Illustration of prior art Illustration of prior art

  Hereinafter, preferred embodiments of the present invention will be exemplarily described in detail with reference to the drawings. However, the dimensions, materials, shapes, relative positions and the like of the component parts described in the following embodiments should be appropriately changed according to the configuration of the apparatus to which the present invention is applied and various conditions. Accordingly, the scope of the present invention is not intended to be limited only to those unless otherwise specified.

  First, the overall configuration of an image forming apparatus to which the present invention is applied will be schematically described with reference to FIGS. 1 and 2. FIG. FIG. 1 is a schematic cross-sectional view showing an example of the image forming apparatus. FIG. 2 is a schematic cross-sectional view in which the right door of the image forming apparatus shown in FIG. 1 is opened. Here, when the image forming apparatus shown in FIG. 1 is viewed from the direction orthogonal to the paper surface of FIG. 1, the front side of the paper surface of FIG. 1 is the front side of the device, and the back side of the paper surface of FIG.

  As shown in FIG. 1, the image forming apparatus 100 fixes an image on an apparatus main body 101 having an image forming unit 11 that forms an image on a recording material P such as paper and a recording material P removable from the apparatus main body 101. And a fixing device 30. The apparatus main body 101 has a flapper 40 as a switching member for selectively switching a path (conveying path) for guiding the recording material P. A flapper 40 as a switching member is rotatably provided on the device body 101. The fixing device 30 in the present embodiment is a unit removably mounted on the apparatus main body 101. Of the insertion and removal directions Ya and Yb of the fixing device 30 with respect to the apparatus main body 101, the removal direction is Ya and the insertion direction is Yb (see FIG. 2).

  In the image forming unit 11, process cartridges 11Y, 11M, 11C, and 11K having photosensitive drums are disposed along the intermediate transfer belt 11a. In the process cartridge 11Y, a yellow toner image is formed on the photosensitive drum, and is primarily transferred to the intermediate transfer belt 11a. In the process cartridge 11M, a magenta toner image is formed on the photosensitive drum, and is superimposed on the yellow toner image of the intermediate transfer belt 11a to be primarily transferred. In the process cartridges 11C and 11K, a cyan toner image and a black toner image are formed on the photosensitive drums, respectively, and similarly, the toner images on the intermediate transfer belt 11a are superimposed on one another and sequentially primary-transferred.

  On the other hand, the recording material P fed from the paper feeding unit 10 stands by in front of the transfer unit 12 and is sent to the transfer unit 12 in timing with the toner image of the intermediate transfer belt 11 a.

  The four color toner images carried on the intermediate transfer belt 11a are conveyed to the transfer unit 12, superimposed on the intermediate transfer belt 11a, and collectively transferred onto the recording material P which is conveyed by sandwiching the transfer unit 12. Thereafter, the recording material P passes through the fixing device 30 so that the toner image is heat-fixed on the recording material P, and is discharged from the paper discharge roller 13 in the case of single-sided printing only. When the sheet is discharged from the sheet discharge roller 13, the flapper 40 switches the conveyance path in the direction of the sheet discharge roller 13 as shown by a broken line in FIG. 1, and the recording material P passes below the flapper 40. In the case of double-sided printing, the leading end of the recording material P passes through the flapper 40 whose conveyance path has been switched in the direction of the reversing roller 14 as shown by the solid line in FIG. The reverse roller 14 conveys the recording material P in the direction of the reverse path 141 until it is completed. Thereafter, the flapper 40 can be switched in the direction of the duplex conveying roller 15 by a switching mechanism described later. Here, when the reversing roller 14 reverses the rotation direction, the recording material P is switched back to the front end of the above-described recording material P, passes over the flapper 40, and is conveyed toward the duplex conveying roller 15. Then, the recording material P passes through the double-sided conveyance path 16 and passes through the image forming unit 11, the transfer unit 12, and the fixing device 30 again. The paper discharge roller 13 is provided downstream of the fixing device 30 in the conveyance direction of the recording material, and is a discharge unit that discharges the recording material. The reversing roller 14 is provided on the downstream side of the fixing device 30 in the conveyance direction of the recording material, and reverses the rotation direction to reversely convey the recording material.

  Here, in the present embodiment, the attitude of the flapper 40 when conveying the recording material P in the direction of the double-sided conveyance roller 15 and the attitude of the flapper 40 when conveying the recording material in the direction of the discharge roller 13 are broken lines in FIG. It is the same as shown by. For this reason, the posture switching operation of the flapper 40 is unnecessary at this time. Therefore, the recording material P having passed through the fixing device 30 reaches the flapper 40 and is discharged toward the discharge roller 13.

  Here, the right door unit 60 including the transfer unit 12 and the double-sided conveyance path 16 is configured to be able to open and close about the right door rotation center 61 with respect to the image forming apparatus main body 101. As shown in FIG. 2, by making the right door unit 60 open with respect to the apparatus main body, it becomes possible to remove the recording material remaining around the transfer portion at the time of paper jam. Further, the fixing device 30 can be removed from the image forming apparatus main body 101 in the removal direction Ya, and the recording material P caught in the fixing device 30 can be easily removed.

  By the way, the operation panel 80, for example, performs operation guidance to the user at the time of paper jam, and sets various image forming apparatuses. The operation panel 80 is disposed on the right side of the sheet discharge reversing portion including the sheet discharge roller 13 and the reversing roller 14, that is, on the right door unit 60 in order to efficiently use the visibility to the user and the space. When the operation panel 80 is rotated together with the right door unit 60, the visibility is deteriorated, so the operation panel 80 is fixedly disposed on the image forming apparatus main body 101. As a result, the paper discharge reversing unit including the paper discharge roller 13 and the reversing roller 14 is also fixedly disposed in the image forming apparatus main body.

[Schematic Configuration of Fixing Device]
Next, with reference to FIGS. 3, 4 and 5, the fixing device 30, which is a unit detachable from the image forming apparatus main body, will be described. FIG. 3 is a schematic view of a fixing device in the image forming apparatus. FIGS. 4A and 4B are perspective views of a pressure application mechanism of the fixing device. FIG. 5 is a cross-sectional view of a pressure application mechanism of the fixing device.

  As shown in FIG. 3, the fixing device 30 includes a heating film assembly 302 as a heating rotator, and a pressure roller 303 as a pressure rotator that is in pressure contact with the heating film assembly 302. The fixing device 30 performs fixing by holding and conveying the recording material P having a toner image while heating by the heating film assembly 302 and the pressure roller 303. An inlet guide 317 for guiding the recording material to the nip portion is disposed upstream of the heating film assembly 302 and the nip portion N of the pressure roller 303 in the recording material conveyance direction. A fixing discharge guide 310 and a fixing reversing guide 311 are disposed downstream of the nip portion N in the recording material conveyance direction. The fixing sheet discharge guide 310 is a first guide member for guiding the recording material P from the nip portion N toward the sheet discharge roller 13. The fixing / reversing guide 311 is a second guiding member for guiding the recording material P, which has been switched back, toward the double-sided conveying roller 15 while guiding the recording material P from the nip portion toward the reversing roller 14. The fixing reversing guide 311 is provided on the upstream side of the fixing discharge guide 310 so as to face the fixing discharge guide 310 in the direction (arrow Yb direction in FIG. 2) in which the fixing device is attached or inserted into the apparatus main body. A fixing / reversing upper guide 312 is disposed on the opposite side of the fixing / reversing guide 311 across the two-sided conveyance path 16.

<Pressure configuration>
As shown in FIGS. 4A and 4B, both ends of the pressure roller 303 are rotatably supported by bearings (not shown) attached to the fixing side plate 339 fixed in the fixing device 30. It is done. A heating film assembly 302 as a heating member is supported by a fixing side plate 339 so as to be movable in the pressure contact direction with the pressure roller 303. A fixing nip portion is formed by pressing the film regulating member 337 of the heating film assembly 302 with pressure plates (parts of pressure applying mechanism) 322 and 323. One end portions of the pressure plates 322 and 323 are hooked on holes 341 and 351 (FIG. 5) of the support frames 324 and 325 attached to the fixing side plate 339. A pressure spring (part of a pressure application mechanism) 340 for pressing the film regulating member 337 while rotating the pressure plates 322 and 323 with the holes 341 and 351 as the rotation centers is the support frames 324 and 325 and the pressure plates 322 and 323. Provided between the

  Here, in order to nip and convey the recording material P having a toner image while heating it, it is necessary to apply a large pressure to the nip portion, and on the other hand, the recording material P caught in the nip portion during paper jam processing When the user removes it, the pressure in the nip needs to be reduced.

  For that purpose, the fixing device 30 has a pressure changing mechanism that changes the pressure applied to the fixing nip portion. The pressure changing mechanism has cams 328 and 329 as cam members acting on the pressure applying mechanism, and acts on pressure plates 322 and 323 which are a part of the pressure applying mechanism by the rotation of the cams 328 and 329. The pressure applied to the fixing nip N can be reduced.

  The cams 328 and 329 as cam members acting on the pressure applying mechanism are fixed on both sides with respect to the cam rotary shaft 350, and one side of the cam rotary shaft 350 has a gear 315 for transmitting the drive to the rotary shaft. doing.

  Further, a gear 314 for driving the pressure roller 303 is provided, and a driving force from a motor (not shown) as a driving source provided in the image forming apparatus main body 101 is transmitted to the gears 315 and 341. Are configured to

  As described above, in order to nip and transport the recording material P having a toner image while heating it, it is necessary to apply a large pressure to the nip portion. As shown in FIG. 5, the distance L1 from the nip N to the center of rotation of the pressure plates 322, 323 in order to efficiently generate pressure, the distance L2 from the center of rotation of the pressure spring 340 into the center of rotation of the pressure plates 322, 323. It is necessary to take long (L2> L1). Furthermore, in order to efficiently reduce the pressure in the nip N at the time of paper jam processing, it is necessary to further increase the distance L3 from the rotation center of the pressure plates 322 and 323 to the contact position of the cams 328 and 329 L3> L2).

  That is, the position of the cam rotary shaft 350 of the cams 328 and 329 from the nip portion N needs to be disposed at a distant place.

<Heating film assembly end cooling>
Here, when a recording material P having a narrow width with respect to the length in the longitudinal direction of the heating film assembly 302 is continuously passed, the area through which the recording material P passes of the heating film assembly 302 always passes continuously. Heat is taken away by the material P. However, since the heat is accumulated in the non-sheet passing area where the recording material P of the heating film assembly 302 does not pass, it is necessary to cool. For this purpose, as shown in FIG. 6, the front cover 354 is provided with a front cover louver 354H which is an air hole for cooling the non-sheet passing area of the heating film assembly 302.

  Here, the cam rotary shaft 350 needs to be disposed at a position that does not disturb the air path for cooling the non-sheet passing area of the heating film assembly 302 described above, so the direction of the upper left in FIG. Need to be placed.

  The above-described fixing discharge guide 310 is disposed so as to cover the cam rotation shaft 350 so that the recording material P advancing in the direction of the discharge roller 13 is not caught.

<Flaper abutment part>
FIG. 7 shows components included in the fixing device 30 for abutting the flapper 40.

  At both ends in the longitudinal direction of the fixing / reversing guide 311, flapper push-up portions 311R and insertion link push-up portions 311F extending toward the cam rotary shaft 350 are respectively provided. The flapper push-up portion 311R is provided on one side in the longitudinal direction (the rear side of the apparatus), pushes up the butting portion 402 of the flapper 40 described later, and moves the recording material P conveyed from the fixing nip toward the paper discharge roller 13. It is arranged to turn the transport path. The insertion link push-up portion 311F is provided on the other side in the longitudinal direction (the front side of the apparatus), and is arranged to push up a unit insertion link 90 described later.

  In addition, a flapper link 360 rotatably provided by a drive source described later is provided on the outside of the above-described flapper push-up portion 311R in order to direct the conveying path of the flapper 40 toward the reverse roller 14 on the cam rotating shaft 350. .

[Fixing device removal mechanism]
Next, with reference to FIG. 8, a schematic configuration of a mounting and demounting mechanism for the image forming apparatus main body 101 of the fixing device 30 will be described.

  In the image forming apparatus main body 101, main body frame horizontal guides 112 and 122 as a pair of detachable guides for supporting the positioning pins 330 of the fixing device 30 are disposed. The body frame horizontal guides 112 and 122 are provided horizontally on the body frames 110 and 120. Similar to the body frame horizontal guides 112 and 122, the body frames 110 and 120 are horizontally provided with a fixing rail 114 for guiding the guide 355 of the fixing device 30. In the fixing device 30, the positioning pin 330 is guided by the body frame horizontal guide portions 112 and 122, and the guide guide portion 355 is similarly guided by the fixing rail 114, thereby maintaining the fixed posture in the insertion and removal directions Ya and Yb. It becomes movable.

<Configuration of Paper Discharge Reversal Unit>
Next, FIG. 9 shows the arrangement of the paper discharge reversing portion fixedly arranged in the image forming apparatus main body 101, and the fixing paper discharge guide 310, the fixing reverse guide 311, and the fixing reverse upper guide 312 of the fixing device 30 arranged detachably. Show. FIG. 9 shows a state in which the fixing device 30 is mounted on the image forming apparatus main body 101 as viewed from the front side of the apparatus, and the flapper 40 is switched to the position shown by the broken line in FIG. The position of the flapper 40 shown in FIG. 9 is a position for guiding the recording material having passed through the fixing device in the direction of the paper discharge roller, and a position for guiding the recording material conveyed by reverse rotation of the reverse roller in the direction of the duplex conveying roller. FIG. 14A shows a state in which the fixing device 30 is attached to the image forming apparatus main body 101 as viewed from the rear side of the apparatus, and the flapper 40 is switched to the position shown by the solid line in FIG. The position of the flapper 40 shown in FIG. 14A is a position for guiding the recording material having passed through the fixing device in the direction of the reverse roller. FIG. 14A shows the entire fixing device 30 mounted on the apparatus main body 101.

  The flapper 40 as a switching member is disposed so as to be rotatable at a predetermined angle on the sheet discharge reversing guide 51 via the flapper pivot shaft 41. The sheet ejection reversing guide 51 is fixed to the sheet ejection reversing frame 52. The flapper 40 is always biased in the direction of arrow E shown in FIG. 9 around the flapper rotation shaft 41 by the biasing force of the biasing spring (biasing member). The flapper 40 comes into contact with the flapper push-up portion 311R of the fixing / reversing guide 311, as the flapper abutment portion 402 provided on the rear side of the flapper 40 abuts against the flapper push-up portion 311R in the process of mounting the fixing device in the image forming apparatus main body. Is rotated in the direction opposite to the direction of the arrow E shown in FIG. Therefore, as shown in FIG. 9, in the state in which the fixing device is attached to the image forming apparatus main body, the flapper 40 has a posture in the conveying path direction toward the sheet discharge roller 13. The flapper 40 at this time is the position shown in FIG. 9 and is located at the first guiding position shown by the broken line in FIG. For this reason, the recording material which has passed through the nip portion of the fixing device is discharged in the first direction through the first conveyance path between the one surface of the flapper 40 of the first guide position and the fixing discharge guide 310. It is guided in the direction of the paper roller 13.

  The flapper 40 at the first guide position has its tip 401 over the insertion / removal trajectory 310 T of the fixing sheet discharge guide 310 in the fixing device in the fixing device in the direction intersecting with the inserting / removing directions Ya and Yb. Only the amount of lap T has entered. In the overlap amount T shown in FIG. 9, the tip end portion 401 of the flapper 40 located at the first guide position intersects the insertion / removal direction Ya, Yb from the insertion / extraction trajectory 310 T of the fixing device. It is the amount of intrusion inside.

  At this time, the tip end portion 401 of the flapper 40 overlaps the fixing / reversing guide 311 as shown in FIG. 9 so that the tip end of the recording material P coming out of the nip portion of the fixing device 30 is not scratched. It is set. In the process of mounting the fixing device on the image forming apparatus main body, the uppermost point of the fixing discharge guide 310 of the fixing device passes under the tip portion 401 of the flapper 40 retracted to the retraction position described later. Thereafter, as described above, the flapper push-up portion 311R of the fixing device abuts against the flapper butting portion 402. As a result, the flapper 40 in the retracted position is rotated, and the leading end 401 of the flapper 40 enters the fixing device from the insertion / extraction trajectory 310T of the uppermost point of the fixing / discharging guide 310 by the overlap amount T. Then, in a state in which the mounting of the fixing device is completed, the tip end portion 401 of the flapper 40 is overlapped with the fixing reversing guide 311 as shown in FIG. Further, as described above, the fixing discharge guide 310 of the fixing device 30 is disposed so as to cover the cam rotation shaft 350.

  On the other hand, the flapper 40 is switched in the direction of the reverse roller 14 by a solenoid 70 described later, in a state where the fixing device is mounted on the image forming apparatus main body as shown in FIG. 14A. The flapper 40 at this time is switched to the second guiding position shown by the solid line in FIG. For this reason, the recording material having passed through the nip portion of the fixing device is different from the first direction through the second conveyance path between the other surface of the flapper 40 of the second guide position and the fixing reversing guide 311 It is guided in the direction of the reverse roller 14 which is the second direction.

  Further, the flapper 40 switched to the second guiding position shown in FIG. 14A is further rotated in the direction opposite to the arrow E direction shown in FIG. 9 as compared with the first guiding position shown in FIG. There is. For this reason, the flapper 40 is in a state in which the tip end portion 401 further intrudes into the inside of the fixing device as compared with the first guide position. That is, the flapper 40 at the second guide position has its tip 401 inside the fixing device from the inserting and removing locus 310T of the uppermost point of the fixing sheet discharge guide 310 in the fixing device in the direction intersecting with the inserting and removing directions Ya and Yb. It is in the state where only the overlap amount Tmax has invaded. In the overlap amount Tmax shown in FIG. 14A, the flapper 40 is positioned at the solid line position shown in FIG. From the inside to the inside of the fixing device. The relationship between the amount of intrusion of the flapper 40 at the first guiding position shown in FIG. 9 and the inside of the fixing device of the flapper 40 at the second guiding position shown in FIG. 14A is T <Tmax. That is, the flapper 40 intrudes into the inside of the fixing device with respect to the fixing device insertion / removal trajectory 310T in the second guiding position shown in FIG. 14A as compared with the first guide position shown in FIG. The overlap amount Tmax is the maximum penetration amount of the flapper 40.

  FIG. 10 shows a link mechanism for rotating the flapper as viewed from the back side of the image forming apparatus main body 101. The link mechanism described below is a switching mechanism that selectively switches the flapper 40 in a state in which the tip end portion 401 has intruded into the fixing device 30 mounted on the apparatus main body 101 to a path (conveyance path) for guiding the recording material. It is. The link mechanism includes a solenoid 70, a solenoid link 71, a flapper link 360, and the like, which will be described later.

  When the solenoid 70 fixedly arranged in the image forming apparatus main body 101 is attracted by an electric signal, the solenoid link 71 is rotated to push down one end of the flapper link 360 and the other end flapper link tip portion 361 abuts the flapper The section 402 is pushed up. As a result, the flapper 40 has a posture in the transport path direction toward the reverse roller 14.

  Here, the suction is stopped by stopping the electric signal of the solenoid 70, and the flapper 40 is returned in the direction of the sheet conveyance path toward the sheet discharge roller 13 by the biasing force of the biasing spring (not shown).

Removal of fixing device
Next, the process of removing the fixing device 30 from the image forming apparatus main body 101 is shown in FIGS. 11 and 14B. Note that FIG. 11 illustrates the fixing sheet discharge guide 310, the fixing inversion guide 311, and the fixing inversion upper guide 312 of the fixing device 30. FIG. 14B shows the entire fixing device 30 in the process of taking out the fixing device 30 from the apparatus main body 101.

  As shown in FIGS. 11 and 14B, in the process of removing the fixing device 30 from the image forming apparatus main body 101, the butting portion 402 of the flapper 40 is released from the flapper push-up portion 311R of the fixing / reversing guide 311. For this reason, the flapper 40 can rotate to an angle at which the flapper tip portion 401 does not overlap with the fixing and discharging guide 310 in the direction intersecting with the insertion and removal direction Y.

  The driving sources such as the solenoid 70 and the motor are generally arranged in the area around the electric base in order to shorten the bundle as much as possible and to arrange them efficiently. That is, in the present embodiment, since the electric board is disposed on the rear side of the image forming apparatus, the solenoid 70 is also disposed on the rear side of the apparatus. Therefore, it is required to make the solenoid 70 as small as possible in the rear side area of the apparatus where the space is relatively small. In general, the suction force of the solenoid varies depending on the number of turns of the built-in coil, so it is necessary to reduce the suction force required to reduce the size of the solenoid itself.

  In this embodiment, in order to reduce the size of the above-mentioned solenoid 70 to a smaller size and to effectively reduce the size of the main body, the flapper biasing force by the biasing spring (arrow shown in FIG. The force in the E direction is reduced. Therefore, the biasing spring does not set the biasing force up to an angle at which the flapper tip end portion 401 does not overlap with the fixing and discharging guide 310 in the direction intersecting with the insertion and removal direction Y, that is, an angle close to horizontal.

  At the front side of the apparatus main body 101, a unit insertion link 90 as a retracting means is provided. The unit insertion link 90 is provided to be able to abut or be separated from the flapper 40. The unit insertion link 90 is biased in a direction (arrow F direction in FIG. 12A) in which the flapper 40 is retracted to the outside of the mounting area of the fixing device. When the unit insertion link 90 pulls the fixing device 30 out of the apparatus main body 101, the flapper 40 is at an angle such that the tip portion 401 does not overlap the fixing discharge guide 310 with respect to the insertion / extraction direction Y. Securely lift. That is, the unit insertion link 90 is a retracting means for retracting the flapper 40 outside the mounting area of the fixing device in the apparatus main body in the process of removing the fixing device from the apparatus main body. The unit insertion link 90 is provided outside the conveyance region of the recording material in the width direction orthogonal to the conveyance direction of the recording material. Here, the mounting area of the fixing device is, as shown in FIG. 14B, an area 30T from the insertion and removal locus 310T of the uppermost point in the insertion and removal directions Ya and Yb of the fixing discharge guide 310 to the lower end portion of the fixing device. is there. The outside of the mounting area where the flapper 40 is retracted is the outside of the mounting area 30T. More specifically, as shown in FIG. 14B, the outer side of the mounting area for retracting the flapper 40 is the outer side (upper side) of the insertion / removal trajectory 310T of the uppermost point in the insertion / removal direction Ya, Yb of the fixing paper discharge guide 310. is there. The flapper tip end portion 401 of the flapper 40 is retracted to a position where it does not overlap with the fixing and discharging guide 310 in the direction intersecting with the inserting and removing directions Ya and Yb.

  FIG. 12A is a perspective view of the periphery of the unit insertion link 90 when the fixing device 30 is attached to the image forming apparatus main body 101. FIG. 12B is a perspective view of the periphery of the unit insertion link 90 disposed on the front side of the fixing reversing guide 311 at the position of the fixing device 30 in FIG. 11 in the process of pulling out the fixing device from the image forming apparatus main body. FIGS. 15A and 16A show unit insertion links in the process of pulling out the fixing device from the image forming apparatus main body. FIGS. 15B to 15C and 16B to 16C show unit insertion links when the fixing device is mounted on the image forming apparatus main body. 15 (a) to 15 (c) show the front side of the device, and FIGS. 16 (a) to 16 (c) show the rear side of the device. Here, the apparatus rear side is one side in the longitudinal direction where the flapper push-up portion 311R is provided in the fixing / reversing guide 311 shown in FIG. The front side of the apparatus is the other side in the longitudinal direction where the insertion link push-up portion 311F is provided in the fixing / reversing guide 311 shown in FIG.

  As shown in FIGS. 12 (a) and 12 (b), the unit insertion link 90 is disposed rotatably around the flapper pivot shaft 41 within a predetermined angle range, and a biasing force in the direction of arrow F always acts. The unit insertion link 90 is provided to be able to abut or be separated from the flapper 40. Specifically, when the unit insertion link 90 is rotated, the insertion link abutment portion 91 of the unit insertion link 90 abuts or separates from the flapper retraction abutment portion 403 of the flapper 40.

  In the process of pulling out the fixing device from the image forming apparatus main body, as shown in FIG. 15A, the unit insertion link 90 is disengaged from the insertion link push-up portion 311F of the fixing device. As a result, the insertion link abutment portion 91 of the unit insertion link 90 abuts against the flapper retraction abutment portion 403 of the flapper 40 by an urging force (not shown), and pushes up the flapper 40. As a result, as shown in FIG. 14B, the flapper 40 is retracted to the outside of the mounting area 30T of the fixing device.

  On the other hand, when the fixing device is attached to the image forming apparatus main body, as shown in FIGS. 15B and 15C, the unit insertion link 90 is pushed up by the insertion link push-up portion 311F of the fixing device. . Thus, the insertion link abutment portion 91 of the unit insertion link 90 is separated from the flapper retraction abutment portion 403 of the flapper 40.

  Further, when the fixing device is mounted to the apparatus main body, the flapper push-up portion 311R pushes up the butting portion 402 of the flapper 40 as shown in FIG. Thus, the flapper 40 is switched to the first guide position (indicated by the broken line in FIG. 1) for guiding the recording material having passed through the nip portion of the fixing device in the direction of the sheet discharge roller. The recording material that has passed through the nip portion of the fixing device passes through the first conveyance path between the fixing paper discharge guide 310 and one side of the flapper 40 at the first guide position, and the discharge roller 13 in the first direction. You will be guided in the direction. At this time, as shown in FIG. 15C, the insertion link abutment portion 91 of the unit insertion link 90 is separated from the flapper retraction abutment portion 403 of the flapper 40.

  Further, in a state where the fixing device is mounted to the apparatus main body, as shown in FIG. 16B, the flapper link 360 provided in the fixing device is rotated by the solenoid link 71 being rotated by the solenoid 70 (see FIG. 10). But pushes up the abutting portion 402 of the flapper 40. As a result, the flapper 40 is switched to the second guide position (solid line position shown in FIG. 1) for guiding the recording material having passed through the nip portion of the fixing device in the direction of the reverse roller. The recording material having passed through the nip portion of the fixing device passes the second conveyance path between the other surface of the flapper 40 at the second guide position and the fixing / reversing guide 311 to the direction of the reversing roller 14 which is the second direction. You will be guided. At this time, as shown in FIG. 15 (b), the insertion link abutment portion 91 of the unit insertion link 90 is separated from the flapper retraction abutment portion 403 of the flapper 40.

  Further, the recording material guided in the direction of the reversing roller 14 is conveyed in the direction of the reversing path 141 by the reversing roller 14 until the rear end reaches the reversing point B shown in FIG. After the trailing edge of the recording material reaches the reversal point B, the flapper 40 is switched to the first guide position (the position indicated by the broken line in FIG. 1). Here, by reversing the rotation direction of the reversing roller 14, the recording material P is reversely transported with the trailing end of the above-described recording material P at the top, passes over the flapper 40, and is transported in the direction of the duplex conveying roller 15. At this time, as shown in FIG. 15C, the insertion link abutment portion 91 of the unit insertion link 90 is separated from the flapper retraction abutment portion 403 of the flapper 40.

  Further, in the process of removing the fixing device from the apparatus main body, as shown in FIG. 16A, the butting portion 402 of the flapper 40 is released from the flapper push-up portion 311R of the fixing device. As a result, the flapper 40 can rotate to an angle at which the flapper tip 401 does not overlap in the direction intersecting the insertion and removal directions Ya and Yb (see FIG. 14B) with respect to the fixing discharge guide 310. Become. Further, in the process of removing the fixing device from the apparatus main body, as shown in FIG. 15A, the unit insertion link 90 is removed from the insertion link push-up portion 311F of the fixing device. As a result, the insertion link abutment portion 91 of the unit insertion link 90 abuts against the flapper retraction abutment portion 403 of the flapper 40 by an urging force (not shown), and pushes up the flapper 40 that has been able to rotate. At this time, the flapper 40 is retracted outside the mounting area 30T of the fixing device as shown in FIG. 14 (b). That is, the flapper tip end portion 401 of the flapper 40 is retracted above the insertion / removal trajectory 310 T of the uppermost point of the fixing and discharging guide 310.

  As shown in FIG. 12A, when the fixing device 30 is attached to the image forming apparatus main body 101, the insertion link push-up portion 311F on the fixing device side abuts against the unit insertion link 90 on the apparatus main body side. Then, the insertion link push-up portion 311F pushes up the unit insertion link 90 in the direction opposite to the biasing force in the arrow F direction. As a result, the insertion link abutment portion 91 of the unit insertion link 90 and the flapper retraction abutment portion 403 of the flapper 40 are separated from each other, and the biasing force in the direction of arrow F acting on the unit insertion link 90 Is not transmitted. Further, even when the fixing device is attached to the apparatus main body and the posture of the flapper 40 is changed in the direction of the reverse roller 14 by attracting the solenoid 70, the insertion link abutment portion 91 and the flapper retraction abutment portion 403 of the flapper 40 Are spaced apart. Therefore, the biasing force in the arrow F direction acting on the unit insertion link 90 is not transmitted to the flapper 40.

  Since the biasing force in the direction of arrow F acting on the unit insertion link 90 does not affect the necessary suction force of the solenoid 70, the size of the solenoid 70 can be further reduced.

  Next, as shown in FIG. 12B, in the process of pulling out the fixing device 30 from the apparatus main body, the unit insertion link 90 is released from the insertion link push-up portion 311F. Then, the insertion link abutment portion 91 of the unit insertion link 90 abuts against the flapper retracting abutment portion 403 of the flapper 40 by the biasing force in the arrow F direction acting on the unit insertion link 90, and the flapper 40 in the arrow F direction Push up. Further, the flapper 40 abuts against the sheet ejection reverse frame abutting portion 521 of the sheet ejection reverse frame 52 by the biasing force, whereby the retracting posture of the flapper 40 is determined.

  FIG. 13 shows the retracted posture state of the flapper 40, that is, the state in which the fixing device 30 is pulled out of the image forming apparatus main body 101.

  The flapper tip end portion 401 of the flapper 40 is retracted more than the insertion / removal trajectory 310T of the uppermost point in the insertion / removal direction Y of the fixing / discharge guide 310 shown in FIG. That is, the flapper 40 is retracted outside the mounting area 30T (see FIG. 14B) of the fixing device 30 in the apparatus main body. Therefore, when the fixing device 30 is inserted and removed, since the flapper tip end portion 401 does not hit the fixing sheet discharging guide 310, that is, the fixing device, the insertion and removal can be performed without stress.

  As described above, in the process of pulling out the fixing device 30 from the apparatus main body, the flapper tip end portion 401 of the flapper 40 is retracted in the direction intersecting with the inserting / removing direction Y. As a result, the size and weight of the image forming apparatus can be reduced, and replacement of the fixing device and operation at the time of paper jam (in JAM) can be smoothly performed.

  In the embodiment described above, the size of the entire image forming apparatus is efficiently suppressed by arranging the insertion link 90 on the front side of the apparatus which has a relatively large space, but the present invention is not limited to this. For example, when there is a space in the device, the biasing force E of the flapper 40 may be increased and the solenoid 70 may be increased without providing the insertion link 90.

  In the embodiment described above, the fixing device has been exemplified as a unit detachable from the image forming apparatus main body, but the present invention is not limited to this. The same effect can be obtained by applying the present invention to a configuration in which another unit (such as a transfer unit) detachable from the apparatus main body has a flapper having the same positional relationship as that of the unit described above. Can.

  In the embodiment described above, the heating film assembly has been exemplified as the heating rotator of the fixing device, but the present invention is not limited to this. Other heating rotators may be used, such as a heating roller including a heating element such as a heater, or an endless belt. Further, although the pressure roller 303 is illustrated as a pressure rotating body of the fixing device, the present invention is not limited to this. Other pressure rotating bodies may be used, such as an endless belt provided with a pressing portion for the heating rotating body.

  In the above-described embodiment, the printer is exemplified as the image forming apparatus, but the present invention is not limited to this. For example, it may be another image forming apparatus such as a copying machine or a facsimile machine, or another image forming apparatus such as a complex machine combining these functions. Similar effects can be obtained by applying the present invention to these image forming apparatuses.

N ... fixing nip portion 30 ... fixing device 40 ... flapper 41 ... flapper rotating shaft 51 ... discharge reversal guide 70 ... solenoid 71 ... solenoid link 90 ... unit insertion link 91 ... insertion link abutment portion 100 ... image forming device 101 ... Image forming apparatus body 302: heating film assembly 303: pressure roller 310: fixing discharge guide 311: fixing reverse guide 311F: insertion link push-up portion 311R: flapper push up portion 312: fixing reverse upper guide 314: gear 315: gear 317: gear 317: entrance Guides 322 and 323 ... Pressure plates 324 and 325 ... Support frames 328 and 329 ... Cams 330 ... Positioning pins 337 ... Film regulating members 339 ... Fixing side plates 340 ... Pressure springs 341 and 351 ... Holes 350 ... Cam rotation shaft 354 ... Front cover 354H ... Cover louver 360 ... flapper link 401 ... flapper tip 402 ... flapper abutment portion 403 ... flapper retraction abutting portion

Claims (11)

An apparatus main body having an image forming unit for forming an image on a recording material;
A unit removably mounted on the device body;
A switching member provided rotatably on the apparatus main body and selectively switching a path for guiding a recording material in a state where the apparatus is inserted into the unit mounted on the apparatus main body;
Retracting means provided in the device body, for retracting the switching member outside the mounting area of the unit in the process of removing the unit from the device body;
An image forming apparatus comprising: The retracting means is provided so as to be able to abut or be separated from the switching member, and is biased in a direction to retract the switching member to the outside of the mounting area of the unit,
2. The apparatus according to claim 1, wherein the retracting means is in contact with the unit in the process of mounting the unit to the apparatus main body, and is separated from the switching member against the biasing force. Image forming apparatus.   The retracting unit releases the contact with the unit in the process of removing the unit from the apparatus main body, and abuts against the switching member by urging force to retract the switching member to the outside of the mounting area of the unit The image forming apparatus according to claim 2,   4. The apparatus according to claim 2, wherein the retracting means is in a state of being separated from the switching member even when the switching member is switched in a state in which the unit is attached to the apparatus main body. Image forming apparatus.   A switching mechanism for selectively switching the switching member to a path for guiding a recording material in a state in which the unit is mounted on the apparatus main body is provided separately from the retracting means. The image forming apparatus according to any one of 4.   The image forming unit of the apparatus body is configured to form a toner image on a recording material, and the unit is a fixing device that fixes the toner image of the recording material. The image forming apparatus according to claim 1.   7. The image forming apparatus according to claim 6, wherein the fixing device is configured to nip and convey a recording material having a toner image while heating by a heating rotating body and a pressing rotating body to perform fixing.   The switching member guides a recording material having passed between the heating rotator and the pressing rotator in a first guide position for guiding the recording material in a first direction, and in a direction different from the first direction. The image forming apparatus according to claim 7, wherein the image forming apparatus is switched to a second guiding position for guiding in two directions. A discharge unit provided downstream of the fixing device in the conveyance direction of the recording material and discharging the recording material;
And a reversing unit provided downstream of the fixing device in the transport direction of the recording material, and reversing transport of the recording material by reversing the rotation direction.
The recording material which has passed between the heating rotating body and the pressing rotating body is guided in the direction of the discharging means by the switching member switched to the first guiding position, and switched to the second guiding position. The image forming apparatus according to claim 8, wherein the image forming apparatus is guided in the direction of the reversing unit by a member.   When forming an image on both sides of the recording material, the recording material having passed between the heating rotating body and the pressure rotating body is guided in the direction of the reversing means by the switching member switched to the second guide position. 10. The image forming apparatus according to claim 9, wherein after that, the switching member is switched to the first guide position, and the rotation direction of the reversing unit is reversed to guide the image forming unit again. apparatus.   The switching member is inserted from the first guide position from the first guide position in a state in which the leading end of the fixing device is inserted into the fixing device while the fixing device is being mounted to the device main body. The image forming apparatus according to any one of claims 8 to 10, wherein the amount of the leading end of the fixing device being intruded into the fixing device is maximized by switching to the second guiding position.