Recording material cooling device, image forming apparatus, and image forming system

Abstract

To improve the efficiency in cooling a heat sink in a configuration in which a belt and the heat sink are integrally and rotatably provided and a fan cools the heat sink.SOLUTION: A cooling fan 40 is attached in a first unit 21U such that when the first unit 21U rotates, the cooling fan rotates together with the first unit 21U. With the provision of the cooling fan 40 in the first unit 21U, air taken in by the cooling fan 40 from the outside passes through the inside of the first unit 21U without passing the outside of the first unit 21U. Thus, the amount of air passing through a heat sink 30 (passage amount) is not largely different from the amount of air taken in (inflow amount). That is, with a simple configuration in which the cooling fan 40 is attached in the first unit 21U, the air taken in by the cooling fan 40 can be efficiently caused to pass through the first unit 21U, and thereby the efficiency in cooling the heat sink 30 can be improved.SELECTED DRAWING: Figure 4

Description

[Technical field]

[0001] The present invention relates to a recording material cooling device that cools a recording material via a belt, and to an image forming apparatus and an image forming system that include the same. [Background technology]

[0002] In an image forming apparatus, a toner image formed on a recording material is fixed to the recording material by heating and pressurizing the toner image formed on the recording material with a fixing device. Therefore, the temperature of the recording material that has passed through the fixing device becomes higher than that before fixing. If the recording material after the toner image is fixed and discharged to a stacking section while still at a high temperature, the stacked recording materials may stick to each other due to the toner. In order to prevent such sticking of the recording material, a recording material cooling device that lowers the temperature of the recording material after the toner image is provided (Patent Document 1). The recording material cooling device described in Patent Document 1 is a belt cooling type device, in which one of a pair of belts that sandwich and transport the recording material that has passed through the fixing device is cooled by a heat sink, and the temperature of the recording material is lowered through the cooled belt. The heat sink is disposed inside the endless belt and abuts against the inner peripheral surface of the belt.

[0003] In such a recording material cooling device, a so-called jam may occur, in which the recording material is stuck. In that case, one of the pair of belts can be separated from the other so that the user can remove the stuck recording material. As in the device described in Patent Document 1, in the past, the belt cooled by the heat sink is made rotatable with the heat sink relative to the other belt, and these belts and the heat sink are unitized (called a belt unit). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2015-169705 A Summary of the Invention [Problem to be solved by the invention]

[0005] Incidentally, in order to maintain the cooling efficiency of the heat sink, a fan (called a cooling fan) capable of taking in air from the outside and discharging it is provided in the recording material cooling device so that the outside air (external air) is taken in and passed through the heat sink. Conventionally, the cooling fan has been provided at a position a predetermined distance away from the belt unit so as not to interfere with the rotating belt unit. In other words, a predetermined gap has been provided between the heat sink and the cooling fan. When a predetermined gap is provided between the heat sink and the cooling fan, the passage (also called an air path or air flow) of the air taken in by the cooling fan is branched, and the taken in air passes not only inside the belt unit but also outside the belt unit. In other words, compared with the amount of air taken in from the outside (inflow amount), the amount of air passing through the heat sink (passing amount) is relatively reduced, making it difficult to efficiently cool the heat sink.

[0006] In view of the above problems, the present invention aims to provide a recording material cooling device, an image forming apparatus, and an image forming system that can improve the cooling efficiency of the heat sink compared to conventional devices when a belt and a heat sink are arranged to rotate integrally and the heat sink is cooled by a fan. [Means for solving the problem]

[0007] A recording material cooling device according to one embodiment of the present invention is a recording material cooling device that cools a recording material on which a toner image has been fixed by heating, the recording material cooling device comprising: a belt unit having a rotating endless belt, a plurality of rollers around which the belt is stretched, and a cooling member that cools the belt by contacting an inner peripheral surface of the belt and dissipating heat; a rotating body that contacts an outer peripheral surface of the belt to form a nip portion between the belt and the rotating body and nip-conveys the recording material at the nip portion; a rotating unit that can rotate the belt unit to a contact position where the belt and the rotating body contact each other to form the nip portion, and a separation position where the belt and the rotating body separate from each other to open the nip portion; and a fan unit having a fan that generates an air flow that passes through the cooling member to cool the cooling member, the fan unit being rotatable together with the belt unit. when the belt unit is located at the contact position, the fan unit is located at a first position, and when the belt unit is located at the separation position, the fan unit is located at a second position different from the first position. It is characterized by: Effect of the Invention

[0008] According to the present invention, in a configuration in which a belt unit having a belt and a cooling member that contacts the belt and cools the belt by heat dissipation is rotatable and the cooling member is cooled by blowing air onto it using a fan, it is possible to achieve a simple configuration that improves the cooling efficiency of the cooling member compared to the conventional system. [Brief description of the drawings]

[0009] [Figure 1] FIG. 1 is a schematic diagram illustrating a configuration of an image forming apparatus. [Diagram 2] FIG. 2 is a front view showing the configuration of the recording material cooling device. [Diagram 3] FIG. 4 is a side view showing the recording material cooling device of the first embodiment when it is in a contact position. [Figure 4] FIG. 4 is a side view showing the recording material cooling device of the first embodiment when it is in a separated position. [Diagram 5] FIG. 4 is a side view illustrating an airflow generated by a cooling fan. [Figure 6] 5A and 5B are diagrams for explaining the cooling fan and the main body rear duct, in which (a) is a view of the main body rear side plate side from the cooling fan side in the width direction, and (b) is a view from the recording material transport direction. [Figure 7] FIG. 11 is a side view showing a state in which the recording material cooling device according to the second embodiment is in a contact position. [Figure 8] FIG. 11 is a side view showing a state in which the recording material cooling device according to the second embodiment is in a separated position. [Figure 9] FIG. 1 is a schematic diagram showing an image forming system in which a recording material cooling device is provided outside an image forming apparatus. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] [First embodiment] <Image forming device> The recording material cooling device of this embodiment will be described below. First, a schematic configuration of an image forming apparatus suitable for using the recording material cooling device of this embodiment will be described with reference to FIG. 1. The image forming apparatus 100 shown in FIG. 1 is a tandem-type full-color printer of an electrophotographic system. The image forming apparatus 100 has image forming units Pa, Pb, Pc, and Pd that form images of yellow, magenta, cyan, and black, respectively. The image forming apparatus 100 forms a toner image on a recording material S in response to image information from a document reading device (not shown) that reads a document image or an external device (not shown) such as a personal computer communicably connected to the image forming apparatus 100. Examples of the recording material S include various types of sheet materials such as plain paper, thick paper, rough paper, textured paper, coated paper, and the like, plastic film, and cloth. In this embodiment, the image forming sections Pa to Pd, primary transfer rollers 6a to 6d, intermediate transfer belt 80, secondary transfer inner roller 14, secondary transfer outer roller 11, and tension rollers 15 and 16 constitute an image forming unit 200 that forms a toner image on recording material S.

[0011] The conveying process of the recording material S of the image forming apparatus 100 will be described. The recording material S is stored in a stacked form in a paper feed cassette 10, and is sent out from the paper feed cassette 10 by a paper feed roller 13 in accordance with the image formation timing. The recording material S sent out by the paper feed roller 13 is conveyed to a registration roller 12 arranged in the middle of a conveying path 114. Then, after the registration roller 12 performs skew correction and timing correction on the recording material S, the recording material S is sent to a secondary transfer portion T2. ​​The secondary transfer portion T2 is a transfer nip portion formed by a secondary transfer inner roller 14 and a secondary transfer outer roller 11, and a toner image is transferred onto the recording material in response to the application of a secondary transfer voltage to the secondary transfer outer roller 11.

[0012] The process of forming an image sent to the secondary transfer portion T2 at the same timing as the process of conveying the recording material S to the secondary transfer portion T2 described above will be described. First, the image forming portions will be described. The image forming portions Pa, Pb, Pc, and Pd for each color are configured almost the same except that the toner colors used in the developing devices 1a, 1b, 1c, and 1d are different, that is, yellow, magenta, cyan, and black. Therefore, the following description will be given of the black image forming portion Pd as a representative, and the description of the other image forming portions Pa, Pb, and Pc will be omitted.

[0013] The image forming section Pd is mainly composed of a developing device 1d, a charging device 2d, a photosensitive drum 3d, a photosensitive drum cleaner 4d, and an exposure device 5d. The surface of the photosensitive drum 3d, which is rotated in the direction of the arrow R1, is uniformly charged in advance by the charging device 2d, and then an electrostatic latent image is formed on the surface of the photosensitive drum 3d by the exposure device 5d, which is driven based on a signal of image information. Next, the electrostatic latent image formed on the photosensitive drum 3d is developed into a toner image by the developing device 1d using a developer. Then, the toner image formed on the photosensitive drum 3d is primarily transferred onto the intermediate transfer belt 80 in response to the application of a primary transfer voltage to a primary transfer roller 6d, which is disposed with the image forming section Pd and the intermediate transfer belt 80 sandwiched therebetween. A small amount of primary transfer residual toner remaining on the photosensitive drum 3d is collected by the photosensitive drum cleaner 4d.

[0014] The intermediate transfer belt 80 is stretched by the inner secondary transfer roller 14 and tension rollers 15 and 16, and is driven in the direction of the arrow R2. In this embodiment, the tension roller 16 also serves as a drive roller for driving the intermediate transfer belt 80. The image forming processes of each color, which are processed in parallel by the image forming units Pa to Pd, are performed at a timing when the images are sequentially superimposed on the toner images of the upstream colors that have been primarily transferred onto the intermediate transfer belt 80. As a result, a full-color toner image is finally formed on the intermediate transfer belt 80, and is conveyed to the secondary transfer unit T2. Note that the secondary transfer residual toner after passing through the secondary transfer unit T2 is removed from the intermediate transfer belt 80 by the transfer cleaner 22.

[0015] Through the above-described conveying process and image forming process, the timing of the recording material S and the full-color toner image coincides at the secondary transfer portion T2, and the secondary transfer is performed. After that, the recording material S is conveyed to the fixing device 50, where a predetermined pressure and heat are applied to fix the toner image on the recording material. The fixing device 50 conveys the recording material S on which the toner image has been formed by sandwiching and conveying it, and heats and pressurizes the conveyed recording material S to fix the toner image on the recording material S. That is, the toner of the toner image formed on the recording material S by heating and pressing is melted and mixed, and is fixed on the recording material S as a full-color image. In this manner, a series of image forming processes is completed. Then, in the case of the present embodiment, the recording material S on which the toner image has been fixed is conveyed from the fixing device 50 to the recording material cooling device 20 and cooled. For example, the temperature of the recording material S is about 90° C. immediately before the recording material cooling device 20, but is reduced to about 60° C. after passing through the recording material cooling device 20.

[0016] In the case of single-sided image formation, the recording material S cooled by the recording material cooling device 20 is sandwiched and conveyed between a pair of discharge rollers 105, and is directly discharged onto a discharge tray 120. On the other hand, in the case of double-sided image formation, a switching member 110 (also called a flapper, etc.) switches the conveying path from the path continuing to the discharge tray 120 to a double-sided conveying path 111, and the recording material S sandwiched and conveyed between the discharge rollers 105 is sent to the double-sided conveying path 111. Thereafter, the leading and trailing ends are switched by a reversing roller 112, and the recording material S is again sent to a conveying path 114 via a double-sided path 113. The subsequent conveyance and the image formation process on the back side (second side) are the same as those described above, and therefore will not be described.

[0017] <Recording material cooling device> Next, an overview of the recording material cooling device 20 will be described with reference to FIG. 2. The recording material cooling device 20 shown here is a belt-cooling type recording material cooling device. As shown in FIG. 2, the recording material cooling device 20 includes a first unit 21U and a second unit 25U. The first unit 21U as a belt unit includes an endless first belt 21, first belt tension rollers (22a to 22d), and a heat sink 30. On the other hand, the second unit 25U includes an endless second belt 25, second belt tension rollers (26a to 26d), and pressure rollers (26e, 26f). Both the first belt 21 and the second belt 25 are film-like endless belts formed, for example, from a high-strength polyimide resin.

[0018] In the first unit 21U, the first belt 21 is stretched 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). For example, the roller 22d is rotated by the drive motor, so that the first belt 21 moves in the direction of the arrow Q. The roller 22d as the drive roller has, for example, a rubber layer with a thickness of 1 mm on the surface, and is formed to have an outer diameter of φ40 mm.

[0019] Roller 22b is a steering roller that is provided in contact with the inner circumferential surface of first belt 21 so as to be able to stretch first belt 21 together with roller 22c, and controls deviation in the width direction (the direction of the rotation axis of roller 22c) of first belt 21. Roller 22b has a rubber layer with a thickness of 1 mm on its surface, and can control meandering of first belt 21 by performing steering control to turn a steering angle with respect to roller 22c as the first roller.

[0020] Further, in addition to the first belt tension rollers (22a to 22d), a heat sink 30 is provided on the inside of the first belt 21. Both ends of the rotation shaft of the first belt tension rollers (22a to 22d) are rotatably supported by a pair of front and rear plates 71 and 72 (see FIG. 3 described later) arranged at an interval in the width direction in the first unit 21U. Further, the heat sink 30 is fixed and held by the front plate 71 (first holding plate) and the rear plate 72 (second holding plate) so as to abut against the inner circumferential surface of the first belt 21. The front plate 71 and the rear plate 72 are formed of, for example, a highly rigid metal plate.

[0021] The recording material S on which the toner image is fixed is sandwiched between the first belt 21 and the second belt 25, and is conveyed in the recording material conveying direction (arrow R direction) according to the rotation of these belts. At that time, the recording material S passes through a cooling nip portion T4, which is a nip portion formed by the contact between the first belt 21 and the second belt 25. The first belt 21 forming the cooling nip portion T4 is cooled by a heat sink 30. The heat sink 30 is in contact with the inner peripheral surface of the first belt 21 at a position forming the cooling nip portion T4 in order to efficiently cool the recording material S. When the recording material S passes through the cooling nip portion T4, the temperature is lowered through the first belt 21 cooled by the heat sink 30. The width direction of the first belt 21 described above is a direction perpendicular to the sheet conveying direction and the vertical direction in the cooling nip portion T4.

[0022] The heat sink 30 as a cooling member is a heat dissipation plate made of a metal such as aluminum. The heat sink 30 has a heat receiving portion 30a for contacting the first belt 21 to absorb 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 large number of heat dissipation fins in order to increase the contact area with the air taken in from the outside by the cooling fan 40 and promote efficient heat dissipation. For example, the heat dissipation fins are set to a thickness of 1 mm, a height of 100 mm, and a pitch of 5 mm, and the fin base 30c is set to a thickness of 10 mm.

[0023] On the other hand, in the second unit 25U, the second belt 25 as a rotating body is stretched over a plurality of second belt tension rollers (26a to 26d) and abuts against the outer circumferential surface of the first belt 21. Both ends of the rotation shaft of these second belt tension rollers (26a to 26d) are rotatably supported by a pair of front and rear plates 73 and 74 (see FIG. 3) arranged at an interval in the width direction in the second unit 25U. The front plate 73 and the rear plate 74 of the second unit 25U are formed of a highly rigid sheet metal, similar to the front plate 71 and the rear plate 72 of the first unit 21U. The recording material cooling device 20 is attached to the device body 100A by fixing the front plate 73 and the rear plate 74 to a support frame or the like as the device body 100A of the image forming apparatus 100. In the present embodiment, when the recording material cooling device 20 is attached, the first unit 21U moves relative to the apparatus main body 100A, while the second unit 25U does not move relative to the apparatus main body 100A. Here, the apparatus main body 100A refers to a support frame that supports each unit inside the image forming apparatus 100, and an exterior cover and the like that configure the appearance of the image forming apparatus 100 are attached to it.

[0024] The first belt 21 and the second belt 25 come into contact with each other to form a cooling nip T4 for cooling the recording material S on which the toner image is formed while pinching and conveying it. Although not shown, the roller 26d is connected to a drive motor that drives the roller 22d via a drive gear, and the rotational drive force of the drive motor is transmitted by the drive gear to rotate the second belt 25 in the direction of the arrow R. In this way, the second belt 25 rotates together with the first belt 21. The roller 26b is a steering roller that controls the shift in the width direction of the second belt 25, and performs a steering operation to turn a steering angle with respect to the roller 26c around the center of the width direction, thereby controlling the meandering of the second belt 25.

[0025] A plurality of pressure rollers (26e, 26f) are provided on the inner side of the second belt 25 to pressurize the second belt 25 toward the heat sink 30 disposed on the inner side of the first belt 21. In the present embodiment, as an example, the pressure roller 26e is provided on the upstream side of the cooling nip T4 and the pressure roller 26f is provided on the downstream side of the cooling nip T4 with respect to the recording material conveying direction (arrow R direction). These pressure rollers (26e, 26f) press the second belt 25 with a pressure of, for example, 4.9 N (0.5 kgf), and the first belt 21 is reliably abutted against the heat sink 30 via the second belt 25. Note that both ends of the rotation shaft of the pressure rollers (26e, 26f) are rotatably supported by the front plate 73 and the rear plate 74 (see FIG. 3) of the second unit 25U, similarly to the second belt tension rollers (26a to 26d).

[0026] Although an example in which both the first belt 21 and the second belt 25 are driven has been shown here, the present invention is not limited thereto. For example, only the first belt 21 may be driven so that the second belt 25 is driven by the first belt 21, or only the second belt 25 may be driven so that the first belt 21 is driven by the second belt 25. Also, a roller (rotating body) may be used instead of the second belt 25 and brought into contact with the first belt 21 to form the cooling nip portion T4.

[0027] The first unit 21U and the second unit 25U are disposed above and below in the direction of gravity, and the first unit 21U having the heat sink 30 is provided so as to be rotatable upward with respect to the second unit 25U not having the heat sink 30. Here, an example is shown in which a rotation fulcrum is provided on the rear side plate 72 side, and the front side plate 71 side is moved up and down. The first unit 21U can move relative to the second unit 25U between a contact position (see FIG. 3) where the first belt 21 contacts the second belt 25 and a separation position (see FIG. 4) where the first belt 21 is separated from the second belt 25. This is to allow a user to separate the first belt 21 and the second belt 25 and remove the recording material S sandwiched in the cooling nip portion T4 when a so-called jam occurs in the recording material cooling device 20, in which the recording material S is stuck in the device. The apparatus main body 100A is provided with a front door 81 (see FIGS. 3 and 4) that can be opened and closed so that the user can manually connect and separate the first belt 21 and the second belt 25. If a jam occurs in the recording material cooling device 20, the user can access the recording material cooling device 20 by opening the front door 81. If the side surface of the image forming apparatus 100 on which the front door 81 is provided is the front surface (front face) of the image forming apparatus 100, the above-mentioned width direction is the same as the front-rear direction of the image forming apparatus 100.

[0028] Incidentally, in the belt-cooling type recording material cooling device 20, in order to maintain the cooling efficiency of the heat sink 30, the temperature of which rises with use, it is advisable to take in air from the outside into the apparatus main body 110A and pass it through the heat sink 30 to cool the heat sink 30. For this reason, a cooling fan 40 for cooling the heat sink 30 has conventionally been provided as shown in Fig. 2. However, as already described, in conventional apparatuses, the cooling fan 40 has been provided on the apparatus main body 110A side, away from the first unit 21U, so as not to rotate integrally with the rotating first unit 21U and so as not to interfere with the first unit 21U.

[0029] In the conventional case, as described above, a predetermined gap must be provided between the cooling fan 40 and the first unit 21U so that the cooling fan 40 does not interfere with the first unit 21U when the first unit 21U is rotated. Therefore, the passage of air taken in by the cooling fan 40 (called an air path or air flow) is branched in the device main body 110A, and the air passes not only inside the first unit 21U (specifically, the first belt 21) but also outside the first unit 21U. That is, when there is a gap on the cooling fan 40 side through which air can flow in, the inflow of air from the outside of the first unit 21U, which has a relatively small pressure loss, increases compared to the inside of the first unit 21U, which has a large pressure loss due to the heat sink 30, due to the characteristics of the cooling fan 40. As a result, the amount of air passing through the heat sink 30 becomes relatively small, and the cooling efficiency of the heat sink 30 may decrease.

[0030] As described above, in the past, the amount of air passing through the heat sink 30 in the first unit 21U (passing amount) was relatively small compared to the amount of air taken in by the cooling fan 40 into the device main body 110A (inflow amount), making it difficult to efficiently cool the heat sink 30.

[0031] In view of the above, the recording material cooling device 20 of this embodiment is designed to improve the cooling efficiency of the heat sink 30 by the cooling fan 40 with a simple configuration. Hereinafter, a description will be given using Figs. 3 to 6 with reference to Fig. 2. Figs. 3 and 5 show a state in which the front door 81 is closed and the first belt 21 and the second belt 25 are in an abutting position where they are in contact with each other. Fig. 4 shows a state in which the front door 81 is open and the first belt 21 and the second belt 25 are in a spaced position where they are spaced apart from each other.

[0032] As shown in Fig. 3 and Fig. 4, the recording material cooling device 20 of this embodiment includes the above-mentioned first unit 21U and second unit 25U, as well as a fan unit 400 and a rotating mechanism unit 500. The first unit 21U has a pair of front and rear plates 71 and 72 in the width direction, and the second unit 25U has a pair of front and rear plates 73 and 74 in the width direction. As described above, the front and rear plates 71 and 72 support the first belt tension rollers (22a to 22d) and support the heat sink 30, and the front and rear plates 73 and 74 support the second belt tension rollers (26a to 26d) and pressure rollers (26e, 26f). The front and rear plates 71 and 72, and the front and rear plates 73 and 74 each have a ventilation hole for passing air.

[0033] <Fan unit> The fan unit 400 is attached to the first unit 21U so as to rotate integrally with the first unit 21U. The fan unit 400 has a cooling fan 40 and a fan duct 41. The fan duct 41 has an intake port of approximately the same size as the opening formed in the rear plate 72, and an exhaust port of approximately the same size as the intake port of the cooling fan 40, in order to form an airflow generated by the cooling fan 40 and passing through the heat sink 30. With this configuration, the fan duct 41 is disposed between the rear plate 72 of the first unit 21U and the cooling fan 40. The fan duct 41 connects the first unit 21U and the cooling fan 40 without any gaps, forming a sealed air passage from the exhaust port of the rear plate 72 to the intake port of the fan duct 41, without any air leakage. The cooling fan 40 is, for example, an exhaust fan that can take in air from the outside of the device main body 100A into the first unit 21U and exhaust it. 5, when the cooling fan 40 is operated, air is taken into the device main body 100A from the outside, and the taken-in air passes through the first unit 21U, generating an airflow (arrow X) that reaches the fan duct 41. Note that in this embodiment, a state in which there is no gap between the fan duct 41 and the cooling fan 40 includes a state in which a minute gap occurs due to component tolerances, etc.

[0034] In order to improve the cooling efficiency of the heat sink 30, it is desirable that the air passing through the first unit 21U is at a temperature as low as possible. Therefore, the air inside the device body 100A, which has been heated by the influence of heat from other units (see FIG. 1) such as the fixing device 50 arranged in the device body 100A, is not taken in, but air outside the device body 100A is taken in. Specifically, an intake port for taking in air is formed in the front door 81, which can be opened and closed, and a main body front duct 83 is provided on the inner surface of the front door 81. The main body front duct 83 can be brought into and out of contact with the front side plate 71, and is connected to the first unit 21U when the front door 81 is closed, forming an air passage for passing air from the outside of the device body 100A to the inside of the first unit 21U. In other words, the main body front duct 83 forms an air passage for guiding the air taken in from the intake port of the front door 81 by the cooling fan 40 to the inside of the first unit 21U.

[0035] The air guided to the inside of the first unit 21U cools the heat sink 30 while passing through the inside of the first unit 21U. In order to prevent the air heated by cooling the heat sink 30 from being trapped inside the device main body 100A, the cooling fan 40 is configured to exhaust the air to the outside of the device main body 100A from an exhaust port formed in the main body rear plate 82. In addition, in order to prevent the heated air from diffusing into the device main body 100A, a main body rear duct 84 is provided on the main body rear plate 82. The air immediately after being exhausted by the cooling fan 40 is diffused in a form that is wider downstream than upstream of the air flow, as shown as a diffusion range 94 in FIG. 5. For this reason, an air opening that is larger than the diffusion range 94 is formed in the main body rear duct 84.

[0036] In this embodiment, the main body front duct 83, the first unit 21U, the fan unit 400, and the main body rear duct 84 are aligned in a line in the width direction to efficiently cool the heat sink 30. That is, the main body front duct 83, the first unit 21U, the fan unit 400, and the main body rear duct 84 are arranged so as to overlap when viewed from a direction intersecting the recording material transport direction (width direction) so that the airflow (arrow X) passes through the first unit 21U without branching.

[0037] <Rotation mechanism> In order to allow the first unit 21U having the heat sink 30 to rotate upward relative to the second unit 25U not having the heat sink 30, the recording material cooling device 20 of this embodiment is provided with a rotation mechanism 500. As shown in Figures 3 and 4, the rotation mechanism 500 is configured to have a rotation shaft 78 (rotation fulcrum) on the main body rear side plate 82 side and rotate the first unit 21U so as to move the front side plate 71 side up and down. As described above, the fan unit 400 is provided integrally with the first unit 21U, and therefore the rotation mechanism 500 rotates the first unit 21U so that the fan unit 400 (more specifically, the cooling fan 40) does not interfere with the main body rear duct 84.

[0038] The rotation mechanism 500 (rotation unit) is, for example, a hinge having a first rotation support 76, a second rotation support 77, and a rotation shaft 78 as rotation support members. Two rotation mechanism 500 are provided to sandwich the fan unit 400 in the recording material conveying direction. The first rotation support 76 protrudes from the rear plate 72 of the first unit 21U toward the main body rear plate 82 so as not to interfere with the fan unit 400, that is, the fan duct 41 and the cooling fan 40. On the other hand, the second rotation support 77 protrudes from the rear plate 74 of the second unit 25U toward the main body rear plate 82. The first rotation support 76 and the second rotation support 77 are connected by a rotation shaft 78 that is disposed closer to the main body rear plate 82 than the rear plate 72 of the first unit 21U. The rotation shaft 78 is preferably disposed between the intake port and the exhaust port of the cooling fan 40 in the width direction, as shown in FIG. 3, for example.

[0039] The first rotating support 76 is provided to be rotatable around the rotating shaft 78 relative to the second rotating support 77, so that the first unit 21U and the fan unit 400 can rotate integrally with the second unit 25U fixed to the device body 100A, as shown in FIG. 4. In this embodiment, the first unit 21U is configured to rotate, and it is not necessary to provide a predetermined gap between the first unit 21U and the cooling fan 40 for the rotation path of the first unit 21U. This allows the cooling fan 40 and the first unit 21U to be closer than in the conventional configuration, so that the air taken in by the cooling fan 40 does not branch, and the taken in air passes inside the first unit 21U. In other words, most of the air taken in by the cooling fan 40 can pass through the heat sink 30, so the heat sink 30 is efficiently cooled. In addition, the cooling fan 40 can be brought as close as possible to the heat sink 30, so that the cooling efficiency of the heat sink 30 can be easily improved.

[0040] In this embodiment, the cooling fan 40 and the fan duct 41 are always integrally formed. However, any configuration may be used as long as there is no gap between the cooling fan 40 and the fan duct 41 when the first unit 21U is located at the separated position. In other words, a configuration may be used in which a gap is generated between the cooling fan 40 and the fan duct 41 when the first unit 21U is located at the separated position. For example, a configuration may be used in which the cooling fan 40 rotates relative to the first unit 21U using a rotation center different from the rotation mechanism 500, and the cooling fan 40 rotates relative to the fan duct 41 with the rotation of the first unit 21U from the contact position to the separated position. In this case, it is possible to maintain a state in which there is no gap between the cooling fan 40 and the fan duct 41 by, for example, biasing the cooling fan 40 so that it abuts against the fan duct 41 when the first unit 21U is located at the abutment position.

[0041] 3, in this embodiment, the rotation shaft 78 is disposed below a horizontal line W passing through the center of rotation of the cooling fan 40. Here, the center of the cooling fan 40 in the direction of gravity is the center of rotation of the cooling fan 40. In this case, as the first unit 21U rotates, the fan unit 400 rotates in a direction approaching the main body rear duct 84, and a part of the cooling fan 40 enters the main body rear duct 84.

[0042] Figures 6(a) and 6(b) show the positional relationship between the cooling fan 40 and the main body rear duct 84. Figure 6(a) shows the case when viewed from the cooling fan 40 side toward the main body rear side plate 82 side in the width direction, and Figure 6(b) shows the position of the cooling fan 40 with respect to the main body rear duct 84 when viewed in the width direction. The position of the cooling fan 40 when the first unit 21U is in the abutting position (see Figure 3) is indicated by a solid line, and when the first unit 21U is in the separated position (see Figure 4) is indicated by a dotted line.

[0043] As described above, the cooling fan 40 rotates together with the first unit 21U as the first unit 21U rotates, and a part of the cooling fan 40 enters the main body rear duct 84. In this embodiment, as shown in FIG. 6(a), the cooling fan 40 rotates so that the projection surface in the vertical direction is large. In order to achieve this, the above-mentioned rotation mechanism 500 is formed. The intake port of the main body rear duct 84 is formed to a size that includes this projection surface. On the other hand, the cooling fan 40 does not rotate in the recording material conveying direction (arrow R direction) when rotating. Therefore, the intake port of the main body rear duct 84 is formed so that the gap with the cooling fan 40 in the recording material conveying direction is as small as possible. In this way, in this embodiment, the above-mentioned rotation mechanism 500 is provided, so that the cooling fan 40 and the main body rear duct 84 can be brought close to each other, thereby improving the cooling efficiency of the heat sink 30.

[0044] In addition, in this embodiment, as shown in FIG. 6(b), when the first unit 21U rotates, the upper end 40a of the cooling fan 40 in the vertical direction moves more in the width direction than the lower end 40b of the cooling fan 40, and a part of the cooling fan 40 enters the main body rear duct 84. In order to do so, as described above, the rotation shaft 78 is disposed below the horizontal straight line W passing through the rotation center of the cooling fan 40 (see FIG. 3). However, the position of the rotation shaft 78 is determined taking into consideration the fact that the rotation mode of the first unit 21U changes depending on the distance from the rotation shaft 78 to the upper end 74a of the rear side plate 74, which affects the ease with which the user can remove the recording material S. In this embodiment, as shown in FIG. 3, the rotation shaft 78 is disposed below the upper end 74a of the rear side plate 74 of the second unit 25U.

[0045] 4, the above-described arrangement of the rotation shaft 78 prevents the cooling fan 40 from protruding below the upper end surface 25a of the second belt 25 that supports the recording material S from below. Therefore, when the first unit 21U is rotated to remove the retained recording material S, the retained recording material S is not pressed by the cooling fan 40. Therefore, even if the user rotates the first unit 21U, the retained recording material S can be easily removed without damaging the recording material S.

[0046] As described above, in this embodiment, the cooling fan 40 is attached to the rotating first unit 21U via the fan duct 41, so that when the first unit 21U rotates, the cooling fan 40 rotates together with the first unit 21U. In this way, the cooling fan 40 is integrally provided with the first unit 21U, so that the air taken in from the outside by the cooling fan 40 passes through the inside of the first unit 21U without passing through the outside of the first unit 21U. In other words, the amount of air passing through the heat sink 30 (passing amount) is not very different from the amount of air taken in from the outside (inflow amount). In this way, with a simple configuration in which the cooling fan 40 is attached to the rotating first unit 21U, the air taken in by the cooling fan 40 can be efficiently passed through the first unit 21U, thereby improving the cooling efficiency of the heat sink 30. In addition, in this embodiment, the cooling fan 40 can be arranged closer to the heat sink 30 than in the conventional case, so that the cooling efficiency of the heat sink 30 can be easily improved.

[0047] In order to position the cooling fan 40 closer to the heat sink 30, the cooling fan 40 may be attached directly to the rear plate 72 of the first unit 21U without providing the fan duct 41. However, providing the fan duct 41 as described above is advantageous because interference between the cooling fan 40 and the main body rear duct 84 can be avoided by using the rotating mechanism 500 having the above-mentioned simple configuration.

[0048] [Second embodiment] Next, a recording material cooling device 20A of a second embodiment will be described with reference to Fig. 2 and Fig. 7 and Fig. 8. Fig. 7 shows the first unit 21U in the contact position, and Fig. 8 shows the first unit 21U in the separated position. The second embodiment shown here is the same as the first embodiment described above, except for the configuration of the rotation mechanism 500A. Therefore, the same components as those in the first embodiment are denoted by the same reference numerals, and the description thereof will be omitted here.

[0049] 7, in the rotation mechanism 500A, the rotation shafts 78 of the first rotation support 76 and the second rotation support 77 are disposed closer to the main body rear plate 82 than the rear plate 72 of the first unit 21U and above the horizontal straight line W passing through the rotation center of the cooling fan 40. To achieve this, the first rotation support 76 is provided to protrude upward from the rear plate 72, and the second rotation support 77 is provided to protrude upward from the rear plate 74 of the second unit 25U toward the first rotation support 76. The second rotation support 77 is formed, for example, in a substantially L-shape.

[0050] In the case of the rotation mechanism 500A, as shown in FIG. 8, when the first unit 21U rotates, the cooling fan 40 moves in a direction away from the main body rear duct 84. At this time, as can be understood by comparing FIG. 7 with FIG. 8, the lower end 40b of the cooling fan 40 moves more than the upper end 40a in the vertical direction, so that a part of the cooling fan 40 does not enter the main body rear duct 84. In this case, it is possible to bring the cooling fan 40 closer to the main body rear duct 84 than with the above-mentioned rotation mechanism 500. That is, when the first unit 21U is in the abutment position, the cooling fan 40 can be disposed at a position where it has entered the main body rear duct 84 in advance.

[0051] In the case of the rotation mechanism 500 in the first embodiment described above, if the cooling fan 40 is disposed at a position where it is inserted into the main body rear duct 84 in advance, it becomes difficult to rotate the first unit 21U. In contrast, in the case of the rotation mechanism 500A in the second embodiment, this is not likely to occur. In this way, in the second embodiment, by providing the rotation mechanism 500A that moves the cooling fan 40 in a direction away from the main body rear duct 84 when the first unit 21U rotates, it is possible to bring the cooling fan 40 and the main body rear duct 84 closer to each other than in the conventional configuration. This can improve the cooling efficiency of the heat sink 30.

[0052] However, the rotating mechanism 500 of the first embodiment is more advantageous than the rotating mechanism 500A of the second embodiment in the following respects. The advantages of the rotating mechanism 500 are, first, that it is simple in configuration, and, second, that even when the first unit 21U is rotated, the recording material S that is retained is not damaged, and the user can easily remove the recording material S. That is, in the case of the second embodiment, the cooling fan 40 is likely to protrude below the upper end surface 25a of the second belt 25 that supports the recording material S from below, and care must be taken with this point.

[0053] In the second embodiment, since the heat sink 30, which is a heavy structure, is supported by the rotation mechanism 500A, it is preferable to increase the strength of the first rotation support 76 and the second rotation support 77 compared to the first embodiment so that they can withstand a large load. Alternatively, it is preferable to add another means other than the first rotation support 76 and the second rotation support 77, such as hoisting the heat sink 30 with a wire.

[0054] [Other embodiments] In the above-described first and second embodiments, a configuration has been described in which the first unit 21U is provided with a heat sink 30 and the second unit 25U does not have a heat sink, but the second unit 25U may also be provided with a heat sink.

[0055] In the above-described first and second embodiments, the recording material cooling device 20 is provided inside the image forming apparatus 100 (see FIG. 1), but the present invention is not limited to this. For example, the recording material cooling device 20 may be provided outside the image forming apparatus 100. FIG. 9 shows an image forming system 1X in which the recording material cooling device 20 is provided outside the image forming apparatus 100.

[0056] 9 includes an image forming apparatus 100 and an external cooling device 101 connected to the image forming apparatus 100. The external cooling device 101 is configured to be connectable to an apparatus body 100A of the image forming apparatus 100 as one of peripheral devices (called an optional unit or the like) that can be added later to expand the functions of the image forming apparatus 100. The external cooling device 101 is disposed to cool the recording material S discharged from the image forming apparatus 100 and to lower the temperature of the recording material S, which is higher than that before fixing, to a predetermined temperature or lower. The external cooling device 101 includes the above-mentioned recording material cooling device 20 to cool the recording material S.

[0057] The recording material S cooled by the external cooling device 101 is discharged from the external cooling device 101 by a discharge roller 85 and is stacked on a discharge tray 120. The discharge tray 120 is provided so as to be detachable from the external cooling device 101 and the image forming apparatus 100. That is, when the external cooling device 101 is not connected to the image forming apparatus 100, the discharge tray 120 is attached to the image forming apparatus 100 (see FIG. 1). Then, when the external cooling device 101 is connected to the image forming apparatus 100, the discharge tray 120 is removed from the image forming apparatus 100 by an operator and replaced with the external cooling device 101. Note that a plurality of external cooling devices 101 may be connected as peripheral devices. By increasing the number of external cooling devices 101 to be connected, an operator can easily improve the cooling capacity of the recording material S for an existing image forming apparatus 100.

[0058] The image forming system 1X may be configured such that an external cooling device 101 is connected to the image forming apparatus 100 having the recording material cooling device 20 therein. The image forming system 1X may also be configured such that another sheet processing device, such as a curl correction device, is interposed between the image forming apparatus 100 and the external cooling device 101, or such that a further sheet processing device is connected to the external cooling device 101 downstream in the sheet conveying direction. [Explanation of symbols]

[0059] 1X: image forming system, 20: recording material cooling device, 21: belt (first belt), 21U: belt unit (first unit), 22a (22b, 22c, 22d)... roller (first tension roller), 25: rotating body (second belt), 30: cooling member (heat sink, heat sink), 40: fan (exhaust fan, cooling fan), 41: duct (fan duct), 50: fixing device, 71: first holding plate (front plate), 72: second holding plate (rear plate), 76: rotation support member (first rotation support), 78: rotation shaft, 100: image forming device, 200: image forming unit, 400: fan unit, 500 (500A)... rotation unit (rotation mechanism), S: recording material, T4: nip portion (cooling nip portion)

Claims

1. A recording material cooling device for cooling a recording material on which a toner image has been fixed by heating, a belt unit including a rotating endless belt, a plurality of rollers around which the belt is tensioned, and a cooling member that cools the belt by contacting an inner peripheral surface of the belt and dissipating heat therefrom; a rotating body that contacts an outer peripheral surface of the belt to form a nip portion between the belt and the rotating body and that nip and conveys a recording material at the nip portion; a rotating unit that can rotate the belt unit between a contact position where the belt and the rotating body contact each other to form the nip portion and a separation position where the belt and the rotating body separate from each other to open the nip portion; a fan unit having a fan that generates an airflow passing through the cooling member to cool the cooling member, the fan unit is rotatable together with the belt unit, When the belt unit is located at the abutting position, the fan unit is located at a first position, When the belt unit is located at the separated position, the fan unit is located at a second position different from the first position. A recording material cooling device comprising:

2. The rollers each have an axis extending in a width direction intersecting with a conveying direction of the recording material, the belt unit includes a first holding plate and a second holding plate that support both ends of the shafts of the rollers and hold the cooling member, the rotating unit has a rotating shaft extending in a recording material conveying direction, and a rotating support member fixed to the second holding plate and configured to rotatably support the belt unit by the rotating shaft, The fan unit is attached to the second retaining plate.

2. The recording material cooling device according to claim 1,

3. the rotating unit rotates the belt unit such that an upper end of the fan in a vertical direction moves farther in the width direction than a lower end of the fan.

3. The recording material cooling device according to claim 2,

4. The rotation shaft is disposed below a horizontal line passing through a rotation center of the fan.

4. The recording material cooling device according to claim 2, wherein the recording material cooling device is a cooling device for cooling a recording material.

5. the rotating unit rotates the belt unit such that a lower end of the fan in a vertical direction moves farther in the width direction than an upper end of the fan.

3. The recording material cooling device according to claim 2,

6. The rotation shaft is disposed above a horizontal line passing through a rotation center of the fan.

6. The recording material cooling device according to claim 5,

7. the fan unit is provided between the belt unit and the fan and has a duct that forms an airflow generated by the fan; 7. The recording material cooling device according to claim 1, wherein the recording material cooling device is a cooling device for cooling a recording material.

8. the fan is an exhaust fan that exhausts air to the outside of the recording material cooling device; 8. The recording material cooling device according to claim 1, wherein the recording material cooling device is a cooling device for cooling a recording material.

9. The cooling member is a heat sink that comes into contact with the belt and dissipates heat.

9. The recording material cooling device according to claim 1, wherein the recording material cooling device is a cooling device for cooling a recording material.

10. The rotating body is another endless belt, the belt and the other belt form the nip portion for conveying the recording material; 10. The recording material cooling device according to claim 1, wherein the recording material cooling device is a cooling device for cooling a recording material.

11. The belt unit is located above the rotating body in the direction of gravity.

11. The recording material cooling device according to claim 1,

12. an image forming unit for forming a toner image on a recording material; a fixing device that heats the toner image formed by the image forming unit and fixes it onto a recording material; The recording material cooling device according to any one of claims 1 to 11, 1. An image forming apparatus comprising:

13. an image forming apparatus including an image forming unit that forms a toner image on a recording material and a fixing device that fixes the toner image by heating the recording material on which the toner image has been formed; and a recording material cooling device according to any one of claims 1 to 11 that is connected to the image forming apparatus and cools the recording material discharged from the image forming apparatus, 1. An image forming system comprising:

Images