JP7625448B2 - SHEET CONVEYING DEVICE AND IMAGE FORMING SYSTEM - Google Patents

Description

The present invention relates to a sheet transport device that transports sheets, and an image forming system equipped with the same.

Conventionally, image forming devices such as copiers, printers, and facsimiles that form images on sheets (recording materials) are provided with a sheet transport device for transporting the sheets. In image forming devices, a so-called jam may occur in which a sheet becomes stuck in the sheet transport path. In such a case, the sheet transport device is provided with a pair of guide plates that are arranged opposite to each other so as to sandwich the sheet and can be opened and closed so that the user can remove the sheet stuck in the sheet transport device (Patent Document 1). One of the guide plates is provided with a jam release lever that the user can hold and operate so that the user can manually open the sheet transport path. The user can operate the jam release lever with a door that is attached to the device body and can be opened and closed open.

JP 2016-204142 A

As described above, when a jam occurs, the user can open the door and operate the jam release lever to move one of the guide plates to an open position where the sheet transport path is open, and remove the sheet stuck in the sheet transport device. At this time, the moved guide plate is held in the open position so that it does not return to the closed position where the sheet transport path is not open while the user is removing the sheet. Therefore, after removing the sheet, the user must return the guide plate to the closed position before closing the door. In the device described in the above-mentioned Patent Document 1, if the guide plate is not returned to the closed position, it is difficult to close the door. However, if the user forgets to return the guide plate to the closed position and forcibly closes the door with the guide plate in the open position, there is a risk that the guide plate and other parts will be damaged by being pressed hard by the door.

The present invention has been made in consideration of the above problems, and aims to provide a sheet conveying device and image forming system that can prevent damage to the guide plates that accompany the closing operation of the door, even if the door is closed while the pair of guide plates that guide the sheets are in the open position.

A sheet transport device according to an embodiment of the present invention includes transport means for transporting a sheet, a first guide for guiding a sheet transported by the transport means, a second guide provided to face the first guide and capable of forming a sheet transport path through which a sheet passes together with the first guide, the second guide being rotatable between a first position which forms the sheet transport path and a second position which opens the sheet transport path, holding means for holding the second guide at the second position, a cover which constitutes part of the exterior of the device and which is movable between a closed position which covers the second guide and an open position in which the second guide can be operated, and a mechanism for connecting the first guide and the second guide. the cover is provided with a support frame supporting a cover and the cover, and an abutment portion provided on the cover and abutting the second guide, the cover is capable of being opened and closed about a rotation axis extending vertically relative to the support frame, the second guide is capable of being rotated between the first position and the second position about a rotation axis extending horizontally, and the abutment portion is arranged to release the holding of the second guide by the holding means by abutting against the second guide when the cover moves from the open position to the closed position with the second guide located at the second position and held by the holding means.

An image forming system according to one embodiment of the present invention includes an image forming unit that forms a toner image on a sheet, a fixing device that fixes the toner image by heating the sheet on which the toner image has been formed, and a sheet cooling device that cools the sheet heated by the fixing device, the sheet cooling device including a sheet cooling means having a first belt, a second belt that contacts an outer peripheral surface of the first belt to form a nip portion for nipping and transporting the sheet, and a heat sink that contacts an inner peripheral surface of the first belt, a conveying means that conveys the sheet, a first guide that guides the sheet conveyed by the conveying means, and a sheet cooling means that is provided at least one of upstream and downstream of the sheet cooling means in the sheet conveying direction at the nip portion, the sheet cooling means being arranged opposite to the first guide, The sheet cooling device comprises a second guide that is rotatable to a first position that, together with the first guide, forms a sheet transport path through which a sheet passes and a second position that opens the sheet transport path, a holding means that holds the second guide at the second position, a cover that constitutes part of the appearance of the sheet cooling device and is movable to a closed position that covers the second guide and an open position in which the second guide can be operated, and an abutment portion provided on the cover that abuts against the second guide, wherein the abutment portion is positioned so as to release the holding of the second guide by the holding means by abutting against the second guide when the cover moves from the open position to the closed position while the second guide is positioned at the second position and is held by the holding means.
A sheet transport device according to an embodiment of the present invention includes a transport means for transporting a sheet, a first guide for guiding a sheet transported by the transport means, a second guide provided to face the first guide and capable of forming a sheet transport path through which a sheet passes together with the first guide, the second guide being rotatable between a first position which forms the sheet transport path and a second position which opens the sheet transport path, a holding means for holding the second guide at the second position, a cover which constitutes a part of the exterior of the device and which is movable between a closed position which covers the second guide and an open position in which the second guide can be operated, and a holding means provided on the cover. the cover is provided with a first abutment portion that abuts against the second guide, and a second abutment portion that is provided on the cover and abuts against the second guide at a position different from the first abutment portion, wherein the first abutment portion is arranged to abut against the second guide, thereby releasing the holding of the second guide by the holding means, when the cover moves from the open position to the closed position in a state in which the second guide located at the second position is held by the holding means, and the second abutment portion is arranged to abut against the second guide to position the second guide at the first position when the cover is in the closed position.

According to the present invention, when the second guide plate is in the open second position that opens the sheet transport path relative to the first guide plate, even if the door is closed, it is possible to suppress damage to the guide plates that occurs as the door closes with a simple configuration.

1 is a schematic diagram showing a configuration of an image forming system according to an embodiment of the present invention. FIG. FIG. 4 is a partial perspective view showing the external cooling device with the front door open. FIG. FIG. 2 is a schematic diagram showing a sheet cooling unit. 1A is a perspective view showing an upstream transport unit as viewed obliquely from above, and FIG. FIG. FIG. 4 is an enlarged perspective view of an upstream holding release portion. FIG. 4 is an enlarged top view of the upstream holding release portion. 5A to 5D are schematic diagrams to explain the upstream guide section, (a) before the front door is closed, (b) when the front door is partially closed, (c) when the front door is further partially closed, and (d) after the front door is closed. FIG. 4 is an enlarged perspective view of a downstream holding release portion. FIG. 4 is an enlarged top view showing the downstream holding release portion.

<Image forming system>
The schematic configuration of an image forming system according to this embodiment will be described with reference to Figures 1 and 2. The image forming system 1X shown in Figure 1 includes an image forming apparatus 100, an external cooling device 110, and a sheet processing apparatus 310.

<Image forming apparatus>
The image forming apparatus 100 is a tandem-type full-color printer of an electrophotographic system. The image forming apparatus 100 has image forming units PY, PM, PC, and PK that form images of yellow, magenta, cyan, and black, respectively. The image forming apparatus 100 forms and fixes a toner image on a sheet S in response to an image signal from an external device, such as a document reading device (not shown) connected to the apparatus main body 100A or a personal computer connected to the apparatus main body 100A in a communicable manner. The sheet S may be any of various types of sheet materials, such as plain paper, thick paper, rough paper, textured paper, coated paper, plastic film, cloth, and the like. In this embodiment, the image forming units PY to PK, the primary transfer roller 5, the intermediate transfer belt 8, the secondary transfer inner roller 9, the secondary transfer outer roller 10, and the tension rollers 121 and 122 constitute an image forming unit 200 that forms a toner image on the sheet S.

As shown in FIG. 1, the image forming units PY, PM, PC, and PK are arranged in line in the direction of movement of the intermediate transfer belt 8 within the device main body 100A (inside the device main body). The intermediate transfer belt 8 is stretched around multiple rollers and configured to run in the direction of arrow R2 in the figure. The intermediate transfer belt 8 carries and transports the toner image transferred from the photosensitive drum 1 (see FIG. 2). A secondary transfer outer roller 10 is arranged at a position opposite to the secondary transfer inner roller 9 that stretches the intermediate transfer belt 8, sandwiching the intermediate transfer belt 8 therebetween, forming a secondary transfer unit T2 that transfers the toner image on the intermediate transfer belt 8 to the sheet S.

A cassette 12 containing sheets S is disposed at the bottom of the image forming apparatus 100. The sheets S are transported from the cassette 12 to the registration roller 14 by the transport roller 13. The registration roller 14 then starts to rotate in synchronization with the toner image formed on the intermediate transfer belt 8 as described below, and the sheets S are transported to the secondary transfer section T2. Although only one cassette 12 is shown here, multiple cassettes 12 may be disposed so as to be able to accommodate sheets S of different sizes and thicknesses. In this case, the sheets S are transported selectively from one of the multiple cassettes 12. In addition, the sheets S may be transported from a manual feed section (not shown) or an external paper feed device (not shown) connected to the apparatus main body 100A, instead of from the cassette 12.

The four image forming units PY, PM, PC, and PK of the image forming device 100 have substantially the same configuration, except for the different developing colors. Therefore, here we will explain the image forming unit PK, which forms black images, as a representative example, and omit explanations of the other image forming units.

As shown in FIG. 2, the image forming unit PK is provided with a cylindrical photosensitive drum 1 as a photosensitive member. The photosensitive drum 1 rotates in the direction of arrow R1 at a predetermined process speed. Around the photosensitive drum 1, a charging device 2, an exposure device 3, a developing device 4, a primary transfer roller 5, and a cleaning device 6 are arranged.

The process of forming a full-color image by the image forming apparatus 100 will be described. First, when the image forming operation is started, the surface of the rotating photosensitive drum 1 is uniformly charged by the charging device 2. The charging device 2 is, for example, a corona charger that irradiates charged particles associated with corona discharge to charge the photosensitive drum 1 to a uniform negative polarity dark potential. Next, the photosensitive drum 1 is scanned and exposed by laser light L corresponding to an image signal emitted from the exposure device 3. As a result, an electrostatic latent image corresponding to the image signal is formed on the surface of the photosensitive drum 1. The electrostatic latent image formed on the photosensitive drum 1 is visualized by the toner (developer) contained in the development device 4, becoming a visible image.

The toner image formed on the photosensitive drum 1 is primarily transferred to the intermediate transfer belt 8 at the primary transfer section T1, which is formed between the photosensitive drum 1 and the primary transfer roller 5 arranged with the intermediate transfer belt 8 sandwiched therebetween. At this time, a primary transfer voltage is applied to the primary transfer roller 5. Toner remaining on the surface of the photosensitive drum 1 after the primary transfer is removed by the cleaning device 6.

Returning to FIG. 1, these operations are performed in sequence at each of the yellow, magenta, cyan, and black image forming units PY to PK, and the four color toner images are superimposed on the intermediate transfer belt 8. After that, in accordance with the timing of the formation of the toner images, the sheet S stored in the cassette 12 is transported to the secondary transfer unit T2. Then, a secondary transfer voltage is applied to the outer secondary transfer roller 10, so that the full-color toner image formed on the intermediate transfer belt 8 is secondarily transferred all at once to the sheet S.

The sheet S onto which the toner image has been secondarily transferred is transported to the fixing device 11. The fixing device 11 has a fixing roller 11a arranged to be freely rotatable, and a pressure roller 11b which rotates while being in pressure contact with the fixing roller 11a. The fixing roller 11a is rotated by a drive motor (not shown) while being in pressure contact with the pressure roller 11b. A halogen heater 11c is arranged within the fixing roller 11a, and the halogen heater 11c heats the fixing roller 11a.

The fixing device 11 clamps and conveys the sheet S on which the toner image has been formed in the fixing nip T3 formed by the fixing roller 11a and the pressure roller 11b, and heats and pressurizes the conveyed sheet S to fix the toner image to the sheet S. That is, the toner of the toner image formed on the sheet S is melted and mixed by the heating and pressure, and is fixed to the sheet S as a full-color image. In this way, the series of image formation processes is completed. The sheet S on which the toner image has been fixed is then conveyed by the conveying device 170.

In the present embodiment, the image forming apparatus 100 is capable of double-sided printing. In the case of single-sided printing, the sheet S on which the toner image is fixed is discharged by the discharge roller 15 to the outside of the apparatus main body 100A (outside the apparatus main body). In the case of double-sided printing, the sheet S on which the toner image is fixed is conveyed to the double-sided inversion conveying path 600. In the double-sided inversion conveying path 600, the sheet S is inverted to switch the front and back sides of the sheet S. The inverted sheet S is conveyed toward the registration roller 14, and conveyed to the secondary transfer section T2 by the registration roller 14 with the unprinted back side facing the intermediate transfer belt 8 side. In the secondary transfer section T2, the full-color toner image formed on the intermediate transfer belt 8 is secondarily transferred to the sheet S (back side) all at once. After that, the toner image is fixed to the sheet S by the fixing device 11, and the sheet S is discharged to the outside of the apparatus main body 100A.

The image forming apparatus 100 is connected to an external cooling device 110 and a sheet processing device 310 so that the sheet S can be transferred in that order from the upstream side in the conveying direction of the sheet S. The external cooling device 110 and the sheet processing device 310 are configured to be connectable to the image forming apparatus 100 as peripheral devices (optional units) that can be added later to expand the functions of the image forming apparatus 100. The image forming apparatus 100, the external cooling device 110, and the sheet processing device 310 are connected to each other so that data can be sent and received via a communication cable (not shown) capable of serial communication and parallel communication. By connecting to each other so that they can communicate with each other via the communication cable, the image forming apparatus 100 controls the external cooling device 110 and the sheet processing device 310.

The external cooling device 110 of this embodiment has a sheet cooling unit 20 as a sheet cooling means for cooling the sheet S, and an upstream transport unit 40 and a downstream transport unit 60 for transferring the sheet S between the sheet cooling unit 20. The upstream transport unit 40 transports the sheet S discharged from the image forming device 100 and transfers it to the sheet cooling unit 20, and the downstream transport unit 60 receives the sheet S from the sheet cooling unit 20 and transports it toward the sheet processing device 310. In the external cooling device 110, the upstream transport unit 40, downstream transport unit 60, and sheet cooling unit 20 form a series of sheet transport paths 210. A detailed description of the external cooling device 110 as a sheet transport device (or sheet cooling device) will be given later.

The sheet S cooled by the external cooling device 110 is conveyed to the sheet processing device 310. The sheet S conveyed to the sheet processing device 310 is subjected to a punching process in which holes are made in the sheet S, or a stapling process in which a plurality of sheets S are bound and stapled. When the sheet processing device 310 performs a punching process, the sheet S is temporarily stopped in the punching process unit 314 and punched. Then, the conveying path is switched by the discharge destination switching unit 311, and the punched sheet S is discharged to the upper discharge tray 312. On the other hand, when the sheet processing device 310 performs a staple process, the conveying path is switched by the discharge destination switching unit 311, and the sheet S is conveyed to the staple processing tray 315. Then, when a predetermined number of sheets S are placed on the staple processing tray 315, staples are closed by the stapler 316. Then, the stapled bundle of sheets S is discharged to the lower discharge tray 313.

<External cooling device>
Next, the external cooling device 110 will be described with reference to Fig. 3 to Fig. 12(d). Fig. 3 is a schematic diagram showing the external cooling device 110 with the front door 120 open, and Fig. 4 is a top cross-sectional view showing the external cooling device 110 with the front door 120 open.

3 and 4, the device body 110A of the external cooling device 110 is provided with a front door 120 that can be rotated between an open state and a closed state. When the front door 120 is closed, it constitutes part of the external cooling device 110. By opening the front door 120, the user can access the sheet cooling unit 20, the upstream conveying unit 40, the downstream conveying unit 60, and the like in the device body 110A from outside the device body 110A. In this embodiment, the front door 120 can be opened and closed around a rotation axis extending vertically to the device body 110A, which is the support frame of the device body 110A (e.g., the frame 112). In addition, the front door 120 is provided downstream in the sheet conveying direction, closer to the downstream conveying unit 60 than the upstream conveying unit 40, with its rotation axis 125. When a jam occurs, the user can manually operate the upstream conveying unit 40 or the downstream conveying unit 60 with the front door 120 open to remove the sheet S stuck therein. As will be described in more detail later, an upstream closing unit 50 and a downstream closing unit 70 are provided on the inner surface of the front door 120 at positions facing the upstream transport unit 40 and the downstream transport unit 60, respectively, when the front door 120 is closed.

<Seat cooling unit>
An example of the sheet cooling unit 20 is shown in Fig. 5. The sheet cooling unit 20 shown in Fig. 5 is a cooling device of a belt cooling type. As shown in Fig. 5, the sheet cooling unit 20 is roughly divided into a first cooling unit 21U and a second cooling unit 25U. The first cooling unit 21U has an endless first belt 21, and the second cooling unit 25U has an endless second belt 25 that sandwiches and transports the first belt 21 and the sheet S. The first belt 21 and the second belt 25 are endless belts formed in a film shape using a resin such as high-strength polyimide.

The first belt 21 is wound around a plurality of first belt tension rollers 22a to 22d, and at least one of the first belt tension rollers 22a to 22d is rotated by a drive motor (not shown). As a result, the first belt 21 rotates in the direction of arrow B in the figure. On the other hand, the second belt 25 is wound around a plurality of second belt tension rollers 26a to 26d, and is in contact with the outer circumferential surface of the first belt 21. Therefore, the second belt 25 can rotate in accordance with the first belt 21. Note that here, the first belt 21 is driven to make the second belt 25 follow the first belt 21, but the second belt 25 may be driven to make the first belt 21 follow the second belt 25. Alternatively, both the first belt 21 and the second belt 25 may be driven.

The sheet S discharged from the image forming apparatus 100 is sandwiched between the first belt 21 and the second belt 25, and is transported in the transport direction (the direction of the arrow C in the figure) according to the rotation of these belts. At that time, the sheet S passes through the cooling nip T4 formed by the contact between the first belt 21 and the second belt 25. In the case of this embodiment, the first cooling unit 21U has a heat sink 30, and the first belt 21 is cooled by the heat sink 30. The heat sink 30 is arranged so as to contact the inner surface of the first belt 21 at the point where the cooling nip T4 is formed in order to efficiently cool the sheet S. The sheet S is cooled through the first belt 21 when passing through the cooling nip T4. As the sheet S is cooled, the toner on the sheet S is cooled and more firmly fixed on the sheet S.

The heat sink 30 as a cooling means is a heat dissipation plate formed of a metal such as aluminum. The heat sink 30 has a heat receiving portion 30a for contacting the first belt 21 to take heat from the first belt 21, a heat dissipation portion 30b for dissipating heat, and a fin base 30c for conducting heat from the heat receiving portion 30a to the heat dissipation portion 30b. The heat dissipation portion 30b is formed of a number of heat dissipation fins to increase the contact area with the air and promote efficient heat dissipation. In addition, a cooling fan 140 is provided to blow air toward the heat sink 30 (more specifically, the heat dissipation portion 30b) in order to forcibly cool the heat sink 30 itself. The cooling fan 140 is driven by a motor (not shown), and the air volume is set to, for example, "2 m ³ /min". The cooling of the heat sink 30 is not limited to the cooling fan 140.

In the above embodiment, the heat sink 30 is in contact with the first belt 21 to cool the first belt 21, but the present invention is not limited to this. The heat sink 30 may be provided in the second cooling unit 25U to cool the second belt 25. Alternatively, one heat sink 30 may be provided in each of the first cooling unit 21U and the second cooling unit 25U to cool both the first belt 21 and the second belt 25. In addition, the present invention is not limited to the heat sink 30. The first belt 21 and the second belt 25 may be cooled by providing a belt cooling fan that blows air toward the belts, or a water cooling unit that brings a pipe through which cooled liquid is circulated into contact with the belts.

Returning to FIG. 3, the sheet cooling unit 20 described above is provided with a first cooling unit 21U that is rotatable relative to the second cooling unit 25U. In this embodiment, a rotation shaft (not shown) that extends along the sheet conveying direction is provided at the "rear side" opposite the front door 120 in the front-rear direction, which is a direction perpendicular to the vertical direction and the sheet conveying direction. The first cooling unit 21U is configured so that the "front side" where the front door 120 is located in the front-rear direction is opened and closed in the up-down direction. A user can lift the first cooling unit 21U upward by operating the handle 202 of the first cooling unit 21U to release the engagement with the second cooling unit 25U by the latch part 201 having a hook-shaped tip. This is to enable the user to remove the sheet S that is stuck in the sheet cooling unit 20 when a jam occurs. The first cooling unit 21U adopts a so-called free stop configuration in which a damper is provided on the hinge part of the rotation shaft (not shown) so that the first cooling unit 21U can remain at any position in the open state.

<Transport unit>
3, the external cooling device 110 has an upstream transport unit 40 disposed on the upstream side and a downstream transport unit 60 disposed on the downstream side (here, the side closer to the rotation axis of the front door 120) so as to sandwich the sheet cooling unit 20 in the sheet transport direction. The upstream transport unit 40 and the downstream transport unit 60 are also configured to be rotatable so that a user can remove the sheet S remaining in the upstream transport unit 40 or the downstream transport unit 60 in the event of a jam. The upstream transport unit 40 and the downstream transport unit 60 will be described with reference to FIGS. 6(a) and 6(b).

Note that although there are some differences between the upstream transport unit 40 and the downstream transport unit 60, they are essentially the same configuration, so the downstream transport unit 60 will be used as an example for explanation here. For the upstream transport unit 40, the reference numerals of corresponding parts are written in parentheses in the figure. Also, Figures 6(a) and 6(b) show the case where the upper guide portion 60A is in an open position relative to the lower guide portion 60B, where the upper guide portion 60A does not form a sheet transport path within the sheet cooling unit 20.

As shown in FIG. 6(a) and FIG. 6(b), the downstream transport unit 60 includes a lower guide portion 60B and an upper guide portion 60A. In this embodiment, when the upper guide portion 60A is in a closed position relative to the lower guide portion 60B, the lower guide portion 60B and the upper guide portion 60A form a part of the sheet transport path 210 in the external cooling device 110 (see FIG. 1), and the sheet S can be transported.

The lower guide section 60B is provided with a first guide plate 65 and a drive roller 64 (first roller), and the upper guide section 60A is provided with a second guide plate 62 and a driven roller 63 (second roller). When the upper guide section 60A is in the closed position, the lower guide section 60B and the upper guide section 60A face each other so as to sandwich the sheet S. The first guide plate 65 is disposed along the sheet transport path so as to guide one side of the sheet S, and the second guide plate 62 is disposed along the sheet transport path so as to guide the other side of the sheet S opposite to the one side.

The first guide plate 65 has an opening, and a drive roller 64, which is driven to rotate by a motor (not shown), is exposed from the opening and rotatably mounted. The second guide plate 62 has a similar opening, and a driven roller 63 is exposed from the opening so as to abut against the drive roller 64 and rotatably mounted. The driven roller 63 presses against the drive roller 64 by the biasing force of a compression spring (not shown), and the drive roller 64 and driven roller 63, which serve as rotating conveying means, can sandwich and convey the sheet S.

The upper guide portion 60A is provided rotatably with respect to the lower guide portion 60B so as to move between a closed position (first position) in which a sheet transport path is formed to transport the sheet S, and an upper open position (second position) in which the sheet transport path is opened and the sheet S is not transported. The second guide plate 62 of the upper guide portion 60A is rotatable between the closed position and the open position with a horizontally extending rotation axis as the rotation center. The upper guide portion 60A is provided with a jam release lever 61 as an operating means that is held and operated by the user so that the user can manually rotate the upper guide portion 60A between the closed position and the open position. The jam release lever 61 is provided from the end of the second guide plate 62 in the width direction (direction intersecting the sheet transport direction) toward the "front side" where the front door 120 is located (see FIG. 4) so that the user can operate it with the front door 120 (see FIG. 3) open. When moving the upper guide portion 60A from the closed position to the open position, the user grasps the jam release lever 61 and raises it upward, and when moving the upper guide portion 60A from the open position to the closed position, the user grasps the jam release lever 61 and lowers it downward. Note that the jam release lever 61 protrudes toward the front door 120 side beyond the sheet cooling unit 20 so that the user can easily grasp and operate it (see FIG. 4).

In addition, the second guide plate 62 is formed with a pin 68 that protrudes toward the first guide plate 65. When the upper guide portion 60A is moved to the closed position, the pin 68 is inserted into the pin fitting hole 67 formed in the first guide plate 65. As a result, the movement of the pin 68 in the sheet conveying direction is restricted by the pin fitting hole 67, and the relative positions of the upper guide portion 60A and the lower guide portion 60B in the sheet conveying direction are determined. These pins 68 and pin fitting holes 67 are formed near the rotation axes of the driven roller 63 and the driving roller 64 in the sheet conveying direction. In this way, in the downstream conveying unit 60 that is configured to be openable and closable, the amount of alignment deviation between the driven roller 63 and the driving roller 64 that abut and rotate with each other can be suppressed. If the amount of deviation in the alignment between the driven roller 63 and the drive roller 64 can be suppressed, the rotation axis of the driven roller 63 and the rotation axis of the drive roller 64 can be kept parallel, thereby suppressing skewing of the sheet S during transport.

Furthermore, in order to hold the upper guide portion 60A in the closed position, as shown in FIG. 6(b), a long magnet 69 (guide holding magnet) that is long in the sheet conveying direction is attached to the surface of the second guide plate 62 on which the pin 68 is formed. Also, as shown in FIG. 6(a), the first guide plate 65 is formed with a magnet attachment portion 66 at a location facing the magnet 69 when the upper guide portion 60A is in the closed position. When the upper guide portion 60A is moved to the closed position, the magnet 69 is attached to the magnet attachment portion 66 by magnetic force, so that the upper guide portion 60A is held in the closed position. The above-mentioned pin 68, magnet 69, pin fitting hole 67, and magnet attachment portion 66 are provided on the outside (end side) of the widthwise area W that allows the passage of the maximum size of the sheet S to be conveyed so as not to interfere with the conveyance of the sheet S by the driven roller 63 and the drive roller 64.

In addition, in the sheet conveying direction, the magnet 69 is preferably provided at a position where at least a portion overlaps the rotation axis N of the driven roller 43, and accordingly, the magnet attachment portion 66 is preferably provided at a position where at least a portion overlaps the rotation axis M of the drive roller 44. In this way, when the upper guide portion 60A is in the closed position, the magnetic force of the magnet 69 causes the driven roller 43 and the drive roller 44 to abut against each other with uniform and appropriate pressure in the rotation axis direction (width direction), thereby suppressing variation in the sheet conveying force.

In this embodiment, unlike the first cooling unit 21U, the upper guide portion 60A does not have a free stop configuration, and therefore the upper guide portion 60A cannot remain in any position in the open state. However, if the upper guide portion 60A is not maintained in the open position and falls to the closed position by its own weight, it is difficult for the user to remove the sheet S.

In this embodiment, as shown in FIG. 3, two guide holders 130 are provided on the frame 112 of the device main body 110A so that the upper guide portions 40A (60A) of the upstream transport unit 40 and the downstream transport unit 60 can be held in the open position. The guide holders 130 will be described using FIG. 7 with reference to FIG. 3.

<Guide holder>
7, the guide holder 130 has a magnet 131 as a holder, and a magnet attachment portion 132. The magnet 131 is attached to the magnet attachment portion 132 with its tip facing the upper guide portion 60A (here, downward). The guide holder 130 is fixed to the frame 112 of the device main body 110A via the magnet attachment portion 132. A magnet attachment portion 61a made of sheet metal is provided on the tip side in the width direction of the second guide plate 62. The magnet attachment portion 61a may be formed integrally with the jam release lever 61 described above.

The magnet 131 is disposed on the path along which the magnet attachment portion 61a moves as the second guide plate 62 rotates, and when the rotating second guide plate 62 reaches the open position, it is attached to the magnet attachment portion 61a by magnetic force. This holds the upper guide portion 60A in the open position and prevents it from moving from the open position to the closed position due to its own weight. In this case, in order to enable the upper guide portion 60A to move from the open position to the closed position, it is necessary to release the magnet 131 from holding the second guide plate 62. The user can release the magnet 131 from holding the second guide plate 62 by grasping the jam release lever 61 and lowering it downward.

In this embodiment, the upper guide portion 60A is held in the open position by the magnet 131, but this is not limited to this. For example, instead of the magnet 131, a hook-shaped engaging protrusion may be provided on the frame 112 of the device main body 110A, and instead of the magnet attachment portion 61a, an engaged hole may be formed in the upper guide portion 60A. In this case, the upper guide portion 60A is held in the open position by engaging the engaging protrusion with the engaged hole. In addition, the upper guide portion 60A is held in the closed position by the magnet 69, but this is not limited to this. However, as described above, in order to suppress variation in the sheet conveying force, it is preferable to hold the upper guide portion 60A in the closed position by the magnet 69.

The protrusion amount (length) of the pin 68 from the second guide plate 62 is set so that the tip of the pin 68 is inserted into the pin fitting hole 67 before the magnet 69 reaches the magnet attachment portion 66 when the upper guide portion 60A moves from the open position to the closed position. That is, as shown in FIG. 6B, the tip of the pin 68 protrudes toward the lower guide portion 60B more than the magnet 69 (the protrusion amount is larger). In other words, the pin 68 is inserted into the pin fitting hole 67 before the upper guide portion 60A reaches the closed position. In this way, when the upper guide portion 60A moving from the open position to the closed position reaches a position where the pin 68 and the pin fitting hole 67 fit, the upper guide portion 60A and the lower guide portion 60B are positioned in the planar direction by the pin 68 and the pin fitting hole 67. Therefore, the upper guide portion 60A moves to the closed position while being guided by the pin 68 and the pin fitting hole 67, so that the magnet 69 provided on the upper guide portion 60A can be reliably attached to the magnet attachment portion 66 provided on the lower guide portion 60B. This allows the driven roller 63 and the drive roller 64 to be properly abutted against each other.

When a jam occurs, the user first opens the front door 120 and then removes the sheet S stuck in the upstream transport unit 40 or the downstream transport unit 60. For example, if a sheet S is stuck in the downstream transport unit 60, the user lifts the jam release lever 61 upward to move the upper guide portion 60A from the closed position to the open position. After removing the sheet S, the user pushes the jam release lever 61 downward to move the upper guide portion 60A from the open position to the closed position. The user then closes the front door 120. However, if the user closes the front door 120 without returning the upper guide portion 60A to the closed position, the downstream transport unit 60 may be pushed by the front door 120 and damaged. The upstream transport unit 40 may also be damaged in a similar state.

Therefore, in this embodiment, even if the user closes the front door 120 without returning the upper guide portion 40A or the upper guide portion 60A to the closed position, the upstream transport unit 40 or the downstream transport unit 60 is not damaged. The configuration of this embodiment to achieve this is described below.

As shown in FIG. 3, an upstream closing unit 50 and a downstream closing unit 70 are provided on the inner surface of the front door 120. In this embodiment, as the front door 120 closes, the downstream closing unit 70 first comes into contact with the jam release lever 61 of the downstream transport unit 60, and then as the front door 120 closes, the upstream closing unit 50 comes into contact with the jam release lever 41 of the upstream transport unit 40.

<Upstream closing unit>
The upstream closing unit 50 will be described with reference to Fig. 3 and Fig. 8 to Fig. 10(d). As shown in Fig. 3, the upstream closing unit 50 has an upstream holding release part 51 as a release means and an upstream guiding part 52 as a guiding means.

<Upstream side holding release section>
First, the upstream holding release section 51 will be described. The upstream holding release section 51 is provided so as to protrude from the inner surface of the front door 120 and form an inclined surface 51a inclined in the direction of gravity, and the inclined surface 51a is formed so that the upper side penetrates deeper into the device main body 110A than the lower side in the vertical direction. As the front door 120 closes, the upstream holding release section 51 abuts against the jam release lever 41 of the upstream conveying unit 40, and releases the holding of the second guide plate 42 by the upstream guide holder 130 (for details, the magnet 131, see FIG. 7) in the open position.

8 and 9, when the front door 120 is closed, the upstream holding release portion 51 of the front door 120 hits the tip of the jam release lever 41 as an operating means. Note that the downstream closing unit 70 is omitted in FIG. 9. When the front door 120 is further closed after the upstream holding release portion 51 hits the tip of the jam release lever 41, the jam release lever 41 is pushed by the front door 120 and moved downward in the direction of gravity along the inclined surface 51a of the upstream holding release portion 51. As a result, the upper guide portion 40A moves downward, and the magnet attachment portion 41a moves away from the guide holder 130, so that the magnet 131 (see FIG. 7) releases the hold of the upper guide portion 40A (i.e., the second guide plate 42).

After the hold is released, the upper guide portion 40A moves downward as if being pushed by the front door 120, with the jam release lever 41 abutting against the upstream hold release portion 51. In other words, the upstream hold release portion 51 is formed so that the inclined surface 51a splits the widthwise force applied to the upper guide portion 40A as the user closes the front door 120 into widthwise and downward force. This prevents damage to the upper guide portion 40A caused by the closing operation of the front door 120 while it is in contact with the upstream hold release portion 51. In addition, because a widthwise force is applied to the upper guide portion 40A even when the force is split, the upper guide portion 40A does not fall all the way to the closed position due to its own weight.

In this embodiment, while the jam release lever 41 is in contact with the upstream holding release portion 51, one end of the upper guide portion 40A in the sheet transport direction abuts against the guide holder 130, and the movement of the moving sheet in the transport direction is restricted by the guide holder 130. To achieve this, the magnet mounting portion 132 is formed with a restricting surface that extends in the direction of gravity, in this case, in the opening and closing direction of the upper guide portion 40A. That is, the guide holder 130 abuts against the second guide plate 42 on the side of the pivot shaft 125 of the front door 120 (the pivot shaft side, see FIG. 4) in the sheet transport direction, and also functions as a restricting means that restricts the movement of the second guide plate 42 toward the pivot shaft 125 of the front door 120.

<Upstream guide section>
Next, the upstream guide section 52 will be described. As described above, when the upper guide section 40A after the holding is released is moved downward along the inclined surface 51a of the upstream hold releasing section 51, the jam release lever 41 is moved vertically downward and reaches the upstream guide section 52 provided continuously below the upstream hold releasing section 51. The upstream guide section 52 guides the second guide plate 42 to the closed position (first position) via the jam release lever 41 while suppressing the movement of the jam release lever 41 of the second guide plate 42 released from holding by the upstream hold releasing section 51 in the sheet conveying direction.

As shown in FIG. 3, the upstream guide section 52 is formed in a hollow rectangular box shape, and a retraction member 52a is provided therein as a retraction means. An opening is formed in the upstream guide section 52 on the same side as the inclined surface 51a of the upstream hold release section 51, and the retraction member 52a is provided inside the upstream guide section 52 and exposed from the opening. As described below, the retraction member 52a is arranged to be movable in the direction opposite to the closing direction of the front door 120 by hitting the jam release lever 41 as the front door 120 closes.

As shown in FIG. 10(a), the retracting member 52a is rotatably provided on the upstream guide section 52. In this embodiment, the retracting member 52a has a rotation shaft 53 provided on the upper side, and rotates around the upper side as the center of rotation, with the elastic member 52b side (pressing means side) provided vertically below the center of rotation as the free end. The retracting member 52a and the elastic member 52b are provided integrally. The retracting member 52a is biased by a torsion spring 54 as a biasing means toward the opening side of the upstream guide section 52, in other words, toward the same direction as the direction in which the front door 120 is closed.

As described above, when the upstream holding release portion 51 of the front door 120 hits the tip of the jam release lever 41 as the user closes the front door 120, a widthwise force F1 is applied to the upper guide portion 40A. This widthwise force F1 applied to the upper guide portion 40A is divided into widthwise and downward forces by the inclined surface 51a of the upstream holding release portion 51 (resultant force f1). Then, due to the resultant force f1, the hold of the upper guide portion 40A by the magnet 131 is released, and the upper guide portion 40A falls downward while rubbing the jam release lever 41 against the inclined surface 51a.

As the front door 120 continues to close, as shown in FIG. 10(b), the tip of the jam release lever 41 reaches the upstream guide section 52, and the tip of the jam release lever 41 enters the upstream guide section 52 from the opening and abuts against the retracting member 52a. If the front door 120 is further closed in this state, the retracting member 52a is pushed by the jam release lever 41 and rotates in the opposite direction R3 to the biasing direction of the torsion spring 54 around the pivot shaft 53 as the center of rotation. In other words, the retracting member 52a abuts against the jam release lever 41 as the upper guide section 40A moves from the open position to the closed position, and thus swings in the R3 direction. The retracting member 52a then retracts the elastic member 52b from the movement trajectory of the jam release lever 41.

As shown in FIG. 10(c), the upper guide portion 40A is moved to the closed position while the jam release lever 41 slides against the retracting member 52a. At this time, since a force F1 in the width direction is applied to the upper guide portion 40A via the retracting member 52a, the upper guide portion 40A does not fall to the closed position by its own weight. In addition, since the retracting member 52a operates to retract from the jam release lever 41 toward the outside of the front door 120, damage to the upper guide portion 40A caused by the closing operation of the front door 120 is suppressed. In other words, since the retracting member 52a swings to retract from the rotation trajectory of the jam release lever 41, damage to the upper guide portion 40A caused by the closing operation of the front door 120 is suppressed. Note that, since the jam release lever 41 is maintained in a state of being inserted into the upstream guide portion 52 from the opening until the upper guide portion 40A is moved to the closed position, the movement in the sheet conveying direction during the movement is restricted by the upstream guide portion 52.

When the upper guide portion 40A is moved to the closed position, the driven roller 43 of the upper guide portion 40A and the driving roller 44 of the lower guide portion 40B come into contact, and the magnet 49 (guide holding magnet) of the upper guide portion 40A sticks to the magnet attachment portion 46 of the lower guide portion 40B. However, since the driven roller 43 is biased by a compression spring (not shown), when the driven roller 43 (second roller) and the driving roller 44 (first roller) come into contact, a reaction force O acts due to the biasing force of the compression spring. Therefore, when the upper guide portion 40A reaches the closed position, the magnet 49 does not immediately stick to the magnet attachment portion 46, and may stick after the upper guide portion 40A bounces for a while. Therefore, it is preferable to generate a force f3 by the action of the weight of the retracting member 52a and the torsion spring 54, so that the magnet 49 sticks to the magnet attachment portion 46 without bouncing the upper guide portion 40A. To achieve this, in this embodiment, an elastic member 52b such as a rubber plate is provided at the lower end of the retracting member 52a. This elastic member 52b is elastically deformed by hitting against the jam release lever 41, and presses the second guide plate 42 toward the first guide plate 45 via the jam release lever 41. In other words, the elastic member 52b is an example of a pressing means for pressing the jam release lever 41. The elastic member 52b presses the jam release lever 41 of the second guide plate 42 while the second guide plate 42 is moving from the open position to the closed position, thereby pressing the second guide plate 42 against the first guide plate 45 and causing the magnet 49 to adhere to the magnet attachment portion 46. In addition, the elastic member 52b continues to press the jam release lever 41 of the second guide plate 42 in the closed position, so that the second guide plate 42 is positioned at the closed position. In addition, the elastic member 52b swings together with the retracting member 52a to retract from the rotation trajectory of the jam release lever 41, so that the upper guide portion 40A is prevented from being damaged when the front door 120 is closed.

However, the elastic member 52b does not need to always be in contact with the jam release lever 41 when the front door 120 is in the closed state. Even if the elastic member 52b is not in contact with the jam release lever 41 when the front door 120 is in the closed state, the magnet 49 can be attached to the magnet attachment portion 46 without bouncing the upper guide portion 40A even if the biasing force of the torsion spring 54 is increased. In addition, if the elastic member 52b is configured to contact the jam release lever 41 and apply a force to attach the magnet 49 to the magnet attachment portion 46 during the process of the front door 120 moving from the open state to the closed state, the elastic member 52b may not be in contact with the jam release lever 41 when the front door 120 is in the closed state. Note that, in the case of a configuration in which the magnet 49 is not provided as described above, it is sufficient that the elastic member 52b is always in contact with the jam release lever 41 when the front door 120 is in the closed state and presses the second guide plate 42 against the first guide plate 45.

As shown in FIG. 10(d), the force applied by the weight of the retracting member 52a and the biasing force of the torsion spring 54 generate a force f3 on the elastic member 52b of the retracting member 52a, causing the magnet 49 to stick to the magnet attachment portion 46, and the upper guide portion 40A is held in the closed position. In this way, the upstream guide portion 52 moves the upper guide portion 40A in response to the closing operation of the front door 120 so that the second guide plate 42, which has been released from the hold of the magnet 131, does not fall all the way to the closed position under its own weight, while retracting so as not to be damaged by being pushed by the front door 120.

<Downstream closing unit>
Next, the downstream closing unit 70 will be described with reference to Figures 3, 11 and 12. As shown in Figure 3, the downstream closing unit 70 has a downstream holding release section 71 as a release means and a downstream guide section 72 as a guide means. The downstream guide section 72 is formed in a hollow rectangular box shape, and a retraction member 72a as a retraction means is provided therein. The downstream guide section 72 is the same as the upstream guide section 52 of the upstream closing unit 50 described above, and therefore a description thereof will be omitted.

<Downstream holding release section>
The downstream side holding release portion 71 releases the holding of the second guide plate 62 by the downstream side guide holder 130 (more specifically, the magnet 131, see FIG. 7). Although the same inclined surface as the inclined surface 51a of the holding release portion 51 may be formed, in this embodiment, as shown in FIG. 3, an inclined member 71a is used which forms an inclined surface inclined in the width direction in addition to the gravity direction. This is because the downstream conveying unit 60 is disposed on the side closer to the rotation axis of the front door 120, and therefore if the inclined surface is the same as the inclined surface 51a of the upstream holding release portion 51, This is because it is difficult to release the holding of the second guide plate 62 by the guide holding body 130 in response to the closing operation of the door 120. In other words, when the guide holding body 130 is disposed on the side closer to the rotation axis of the front door 120, If the inclination is the same as that of the far side, a larger force must be applied to separate the magnet 131 from the magnet attachment portion 61a (see FIG. 7) than to the far side. Therefore, there is a risk of damaging the downstream transport unit 60. is large.

In this embodiment, therefore, as shown in Figures 11 and 12, an inclined member 71a is provided on the downstream holding release section 71. Figures 11 and 12 show the state in which the inclined member 71a of the downstream holding release section 71 begins to contact the jam release lever 61 of the upper guide section 60A, which is held by the guide holder 130 and in the open position.

The inclined member 71a is provided so as to face the rotation axis 125 side of the front door 120. The position and the direction of the inclined surface of the inclined member 71a are determined based on the rotation direction (arrow V11) of the front door 120 and the position of the guide holder 130 relative to the upper guide portion 60A. As the position of the downstream hold release portion 71 approaches the rotation axis of the front door 120, the ease of applying the force required to separate the magnet 131 from the magnet attachment portion 61a changes. Therefore, the ease of applying the force required to separate the magnet 131 from the magnet attachment portion 61a is adjusted by the direction in which the inclined surface of the inclined member 71a is faced.

In this embodiment, the inclined surface (butting portion) of the inclined member 71a is formed at an angle so that the lower side is closer to the inner surface of the front door 120 than the upper side in the vertical direction. The inclined surface (butting portion) of the inclined member 71a is formed at an angle so that the side closer to the rotation axis of the front door 120 is closer to the inner surface of the front door 120 than the far side. The inclined member 71a is preferably provided so that the angle θ between the "straight line Z, which is perpendicular to the rotation axis X of the upper guide portion 60A located in the open position and passes through the abutment point Q at which the jam release lever 61 of the inclined surface (abutting portion) of the inclined member 71a abuts" and the "straight line Y, which passes through the abutment point Q and the abutment point T at which the second guide plate 62 of the guide holder 130 abuts" is 3° or more and 10° or less. The inclined member 71a is preferably provided so that the angle between the downstream hold release part 71 and the rotation axis of the front door 120 is approximately 3.5°, although this depends on the distance between them.

Here, the downstream holding release portion 71 has been mainly described, but the same relationship also applies to the inclined surface 51a of the upstream holding release portion 51. However, since the positional relationship between the upper guide portion 40A and the upstream guide holder 130 is reversed with respect to the positional relationship between the upper guide portion 60A and the downstream guide holder 130, the shape of the inclined surface 51a of the upstream holding release portion 51 and the inclined surface of the downstream inclined member 71a are different. Since the upstream holding release portion 51 is provided at a position farther away from the rotation axis of the front door 120 than the downstream holding release portion 71, the inclined surface 51a can be inclined in the width direction with respect to the jam release lever 41 as the front door 120 is closed. Therefore, even if the inclined surface 51a has a configuration with a different inclination from the inclined member 71a, the upstream holding release portion 51 can release the hold of the upper guide portion 60A.

When closing the front door 120, the inclined member 71a applies pressure to the upper guide portion 60A in the rotation direction (arrow V11) of the front door 120 via the jam release lever 61 at the point where it comes into contact with the jam release lever 61 (impact point Q). This pressure direction (arrow V11) is set at an angle of 3° to 10° with respect to a direction (straight line Z) perpendicular to the rotation axis X of the rotation shaft 53 (see FIG. 10(a)) of the upper guide portion 60A, which rotates between the open position and the closed position. The inclined member 71a is provided so that this occurs.

In such a case, when the force of closing the front door 120 causes the inclined member 71a to press the upper guide portion 60A in the rotation direction (arrow V11) of the front door 120 via the jam release lever 61, the upper guide portion 60A can move in the direction of arrow V12. Then, the edge of the upper guide portion 60A comes into contact with the regulating surface of the guide holder 130 fixed to the frame 112 (see FIG. 3) of the device main body 110A from the direction of arrow V12. Then, as shown in FIG. 10(a) above, the downstream holding release portion 71 of the front door 120 hits the tip of the jam release lever 61, and the widthwise force F1 applied to the upper guide portion 60A is divided into the widthwise and downward directions by the inclined surface of the inclined member 71a (resultant force f1). Then, due to the resultant force f1, the upper guide portion 60A is released from the guide holder 130, and the upper guide portion 60A falls downward while the jam release lever 61 rubs against the inclined surface of the inclined member 71a. In other words, although the upper guide portion 60A has a long distance to the pivot shaft 53 (see FIG. 10(a)), pressure is applied at a short distance from the jam release lever 61, which is the pressure point, to the regulating surface of the guide holder 130. Therefore, the upper guide portion 60A only needs to have the rigidity required for the transport function and for normal user operation.

As described above, in this embodiment, the upstream closing unit 50 and the downstream closing unit 70 are provided on the inner surface of the front door 120. The downstream closing unit 70 (similar to the upstream closing unit 50) has a downstream holding release portion 71 (51), which abuts against the jam release lever 61 (41) when the front door 120 is closed, and releases the holding of the upper guide portion 60A (40A) by the guide holder 130. In addition, the downstream closing unit 70 (50) has a downstream guide portion 72 (52), and a retraction member 72a (52a) is provided on the downstream guide portion 72 (52) so as to be freely rotatable. As the front door 120 is closed, the jam release lever 61 (41) abuts against the retraction member 72a (52a). If the front door 120 is closed further in this state, the retraction member 72a (52a) is pushed by the jam release lever 61 (41) and retracts in the opposite direction to the closing direction of the front door 120 while sliding against the jam release lever 61 (41). This prevents damage to the downstream transport unit 60 (upstream transport unit 40) even if the user closes the front door 120 while forgetting to close the upper guide portion 60A (40A).

[Other embodiments]
In the above embodiment, as shown in Figures 10(a) to 10(d), the retracting member 52a is biased by the torsion spring 54 on the upstream transport unit 40 side, but this is not limited to the above. For example, it is possible to apply a force (f3) equivalent to that in the case where the torsion spring 54 is provided to the jam release lever 41 by increasing the weight of the retracting member 52a, particularly by making the lower tip side heavier, without providing the torsion spring 54. The same may be true for the downstream transport unit 60 side.

In the above-mentioned embodiment, as shown in Figs. 8 and 12, the upstream guide holder 130 is provided upstream of the upstream upper guide portion 40A in the sheet conveying direction, and the guide holder 130 is provided downstream of the downstream upper guide portion 60A in the sheet conveying direction, but this is not limited to the above. If the angle θ between "a straight line Z that is perpendicular to the rotation axis X of the upper guide portion 60A in the open position and passes through the abutment point Q where the jam release lever 61 of the inclined surface (abutment portion) of the inclined member 71a abuts" and "a straight line Y that passes through the abutment point Q and the abutment point T where the second guide plate 62 of the guide holder 130 abuts" is 3° or more and 10° or less, the positional relationship between the guide holder 130 and the upper guide portion 40A (60A) may be reversed from that of the above-mentioned embodiment.

As in the above-described embodiment, the present invention is not limited to application to the external cooling device 110, but may also be applied to, for example, a conveying device 170 (see FIG. 1) that conveys a sheet S within the device body 100A of the image forming apparatus 100. The above-described embodiment can also be applied to a sheet conveying device that is capable of transferring a sheet S between a sheet cooling unit 20 provided within the device body 100A of the image forming apparatus 100 and the sheet cooling unit 20. That is, the sheet conveying device of this embodiment may be disposed in any location, whether it is disposed within the device body 100A of the image forming apparatus 100 or within the device body 110A of the external cooling device 110.

1X...image forming system, 11...fixing device, 20...sheet cooling means (sheet cooling unit), 21...first belt, 25...second belt, 30...cooling means (heat sink), 41 (61)...operation means (jam release lever), 42 (62)...second guide plate, 43 (63)...conveying means (second roller, driven roller), 44 (64)...conveying means (first roller, drive roller), 45 (65)...first guide plate, 49 (69)...guide holding magnet (magnet), 51 (71)...release means (upstream holding release section, downstream holding release section), 52 (72)...Guide means (upstream guide section, downstream guide section), 52a (72a)...Retraction means (retraction member), 52b...Pressing means (elastic member), 54...Pressing means (torsion spring), 71a...Abutment section, 100...Image forming device, 110...Sheet conveying device (sheet cooling device, external cooling device), 110A...Device body (support frame), 120...Door (front door), 130...Regulation means (guide holder), 131...Holding means (magnet, magnet), 200...Image forming unit, 210...Sheet conveying path, S...Recording material, T3...Nip section (fixing nip section)

Claims (31)

A conveying means for conveying a sheet;
a first guide that guides the sheet conveyed by the conveying means;
a second guide provided opposite to the first guide and capable of forming a sheet transport path through which a sheet passes together with the first guide, the second guide being rotatable between a first position at which the sheet transport path is formed and a second position at which the sheet transport path is opened;
a holding means for holding the second guide at the second position;
a cover constituting a part of the external appearance of the device, the cover being movable between a closed position covering the second guide and an open position in which the second guide can be operated;
a support frame supporting the first guide, the second guide, and the cover;
a contact portion provided on the cover and contacting the second guide,
the cover is capable of being opened and closed about a rotation axis that extends in a vertical direction relative to the support frame;
the second guide is rotatable between the first position and the second position about a rotation axis extending in a horizontal direction;
the abutment portion is disposed so as to release the holding of the second guide by the holding means when the cover moves from the open position to the closed position in a state in which the second guide located at the second position is held by the holding means.
A sheet conveying device comprising: When the holding means releases the second guide, the second guide moves from the second position to the first position by its own weight.
2. The sheet transport device according to claim 1. an operating means provided on the second guide and operated when rotating the second guide;
a pressing means provided on the cover and configured to press the operating means so that the second guide is positioned at the first position;
a retracting means provided on the cover, the retracting means being brought into contact with the operating means of the second guide moving from the second position to the first position and swinging to retract the pressing means from a moving trajectory of the operating means when the second guide moves from the first position to the second position,
3. The sheet conveying device according to claim 1, wherein the sheet conveying device is a sheet conveying device. a guide means provided on the cover, which guides the second guide to the first position via the operation means while suppressing movement of the second guide in the sheet conveying direction of the conveying means when the second guide moves from the second position to the first position;
4. The sheet transport device according to claim 3. the guiding means has an opening into which the operating means of the second guide enters when the second guide moves from the second position to the first position, and guides the operating means along the opening, the operating means moving vertically downward as the cover moves from the open state to the closed state;
The retracting means is provided inside the guiding means and is exposed through the opening.
5. The sheet transport device according to claim 4. The retracting means has a rotation center above the pressing means in the vertical direction, and is provided integrally with the pressing means so as to be rotatable with the pressing means side as a free end.
6. The sheet transport device according to claim 3, wherein the sheet transport device is a sheet conveying device. The retracting means includes a biasing means for biasing the cover in a closing direction.
4. The sheet transport device according to claim 3. the pressing means includes an elastic member that is elastically deformed by hitting against the operating means and presses the second guide toward the first guide via the operating means.
4. The sheet transport device according to claim 3. a guide holding magnet provided on at least one of the first guide and the second guide,
the elastic member presses the operating means so that the second guide is held at the first position by the magnetic force of the guide holding magnet;
9. The sheet transport device according to claim 8. The conveying means includes a first roller provided in the first guide, and a second roller provided in the second guide, which is in contact with and presses the first roller at the first position.
10. The sheet transport device according to claim 1, wherein the sheet transport device is a sheet conveying device. the holding means is a magnet, and holds the second guide at the second position by a magnetic force of the magnet;
11. The sheet transport device according to claim 1, wherein the sheet transport device is a sheet conveying device. The abutment portion is formed obliquely so that a lower side thereof is closer to the inner surface of the cover than an upper side thereof in the vertical direction.
The sheet transport device according to any one of claims 1 to 11 . The abutment portion is formed obliquely so that a side closer to the rotation axis of the cover approaches the inner surface of the cover more than a side farther from the rotation axis.
The sheet transport device according to claim 12 . a restricting means for restricting movement of the second guide toward the pivot shaft of the cover by contacting the second guide on the pivot shaft side of the cover in the sheet conveying direction of the conveying means;
The sheet transport device according to claim 13 . an operating means provided on the second guide and operated when the second guide is rotated;
The second guide is provided so that an angle formed by a straight line perpendicular to the rotation axis of the second guide and passing through a contact point of the contact portion where the operating means contacts, and a straight line passing through the contact point and a contact point of the regulating means where the second guide contacts , is equal to or greater than 3° and equal to or less than 10°.
15. The sheet transport device according to claim 14 . an image forming unit that forms a toner image on a sheet;
a fixing device that fixes the toner image on the sheet by applying heat;
a sheet cooling device that cools the sheet heated by the fixing device,
The sheet cooling device includes:
a sheet cooling means including a first belt, a second belt that contacts an outer peripheral surface of the first belt to form a nip portion for nipping and conveying a sheet, and a heat sink that contacts an inner peripheral surface of the first belt;
a conveying means provided at least one of upstream and downstream of the sheet cooling means in the sheet conveying direction in the nip portion, the conveying means conveying the sheet;
a first guide that guides the sheet conveyed by the conveying means;
a second guide provided opposite to the first guide and rotatable between a first position forming a sheet transport path through which a sheet passes together with the first guide and a second position opening the sheet transport path;
a holding means for holding the second guide at the second position;
a cover that constitutes a part of the exterior of the sheet cooling device and that is movable between a closed position that covers the second guide and an open position that allows the second guide to be operated;
a contact portion provided on the cover and contacting the second guide,
the abutment portion is disposed so as to release the holding of the second guide by the holding means when the cover moves from the open position to the closed position in a state in which the second guide located at the second position is held by the holding means.
1. An image forming system comprising: A conveying means for conveying a sheet;
a first guide that guides the sheet conveyed by the conveying means;
a second guide provided opposite to the first guide and capable of forming a sheet transport path through which a sheet passes together with the first guide, the second guide being rotatable between a first position at which the sheet transport path is formed and a second position at which the sheet transport path is opened;
a holding means for holding the second guide at the second position;
a cover constituting a part of the external appearance of the device, the cover being movable between a closed position covering the second guide and an open position in which the second guide can be operated;
a first contact portion provided on the cover and contacting the second guide;
a second contact portion provided on the cover and contacting the second guide at a position different from the first contact portion;
the first abutment portion is disposed so as to release the holding of the second guide by the holding means when the cover moves from the open position to the closed position in a state in which the second guide located at the second position is held by the holding means, and
the second abutment portion is disposed so as to abut against the second guide to position the second guide at the first position when the cover is in the closed position;
A sheet conveying device comprising: When the holding means releases the second guide, the second guide moves from the second position to the first position by its own weight.
20. The sheet transport device according to claim 17 , an operating means provided on the second guide and operated when rotating the second guide;
a pressing means provided on the cover and configured to press the operating means so that the second guide is positioned at the first position;
a retracting means provided on the cover, the retracting means being brought into contact with the operating means of the second guide moving from the second position to the first position and swinging to retract the pressing means from a moving trajectory of the operating means when the second guide moves from the first position to the second position,
19. The sheet transport device according to claim 17 or 18 . a guide means provided on the cover, which guides the second guide to the first position via the operation means while suppressing movement of the second guide in the sheet conveying direction of the conveying means when the second guide moves from the second position to the first position;
20. The sheet transport apparatus according to claim 19 . the guiding means has an opening into which the operating means of the second guide enters when the second guide moves from the second position to the first position, and guides the operating means along the opening, the operating means moving vertically downward as the cover moves from the open state to the closed state;
The retracting means is provided inside the guiding means and is exposed through the opening.
21. The sheet transport apparatus according to claim 20 . The retracting means has a rotation center above the pressing means in the vertical direction, and is provided integrally with the pressing means so as to be rotatable with the pressing means side as a free end.
22. The sheet transport device according to claim 19, wherein the sheet transport device is a sheet conveying device. The retracting means includes a biasing means for biasing the cover in a closing direction.
20. The sheet transport apparatus according to claim 19 . the pressing means includes an elastic member that is elastically deformed by hitting against the operating means and presses the second guide toward the first guide via the operating means.
20. The sheet transport apparatus according to claim 19 . a guide holding magnet provided on at least one of the first guide and the second guide,
the elastic member presses the operating means so that the second guide is held at the first position by the magnetic force of the guide holding magnet;
25. The sheet transport apparatus according to claim 24 . The conveying means includes a first roller provided in the first guide, and a second roller provided in the second guide, which is in contact with and presses the first roller at the first position.
26. The sheet transport device according to claim 17 , the holding means is a magnet, and holds the second guide at the second position by a magnetic force of the magnet;
27. The sheet transport device according to claim 17 , The first contact portion and the second contact portion are each formed obliquely so that a lower side of the first contact portion and the second contact portion are closer to the inner surface of the cover than an upper side of the first contact portion in the vertical direction.
28. The sheet transport device according to claim 17 , The first contact portion is formed obliquely so that a side closer to the rotation axis of the cover is closer to the inner surface of the cover than a side farther from the rotation axis.
29. The sheet transport apparatus according to claim 28 . a restricting means for restricting movement of the second guide toward the pivot shaft of the cover by contacting the second guide on the pivot shaft side of the cover in the sheet conveying direction of the conveying means;
30. The sheet transport apparatus according to claim 29 . an operating means provided on the second guide and operated when the second guide is rotated;
The second guide is provided such that an angle between a straight line perpendicular to a rotation axis of the second guide and passing through a contact point of the first contact portion where the operating means contacts, and a straight line passing through the contact point and a contact point of the regulating means where the second guide contacts , is 3° or more and 10° or less.
31. The sheet transport apparatus according to claim 30 .

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