JP2013029844A - Transfer material cooling device, and image forming apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a transfer material cooling device which can achieve low heat resistance in a heat transfer path from a transfer material to a heat radiation part, and to provide an image forming apparatus.SOLUTION: In a transfer material cooling device, an endless belt member 16 having satisfactory heat conductivity is stretched over belt cooling rollers 13 and 14 disposed side by side from a fixing device 8 in a conveyance direction D. A transfer material heated by the fixing device 8 is brought into contact with the endless belt member 16 stretched over the belt rollers 13 and 14 to be cooled. Further, the endless belt member 16 heated by the transfer material is cooled by the belt cooling rollers 13 and 14. Accordingly, temperature of the transfer material can be speedily and effectively reduced.

Description

  The present invention relates to a transfer material cooling device used in an image forming apparatus including a fixing unit that heats and fixes a toner image on a transfer material, and an image forming apparatus including the same.

  Electrophotographic image forming apparatuses such as printers, facsimiles, and copying machines record images such as characters, symbols, and photographic images on a transfer material such as paper or an OHP sheet based on image information. There are various types of such image forming apparatuses, and the electrophotographic system is widely used because it can record high-definition images on plain paper at high speed. In recent years, as the speed and color of an image forming apparatus increase, the transfer speed of a transfer material increases in a high-speed output machine, and cooling by a cooling unit becomes insufficient. Further, in a color machine, a plurality of developing devices such as four are required, and as a result, the amount of toner on the transfer material increases, so that a larger fixing device is required to fix the toner image on the transfer material. An amount of heat is required. For this reason, even if a transfer material cooling means is provided after the fixing process by the fixing device, there is a problem that the cooling by the cooling means cannot keep up.

  As described above, when the transfer material immediately after passing through the fixing device is discharged without being sufficiently cooled, the transfer material sticks on the discharge tray, or the transfer material is heated. If the sheet is transported to the duplex unit while holding, there will be a problem of increasing the ambient temperature in the path. In particular, at a location where toner is present, such as a developing device, the toner melts and adheres, which adversely affects the reliability and image quality of the device. Conventionally, as a method of cooling a transfer material, the transfer material is directly cooled by a heat pipe roller in which a transfer material is cooled by an air flow (for example, see Patent Document 1) or a heat pipe roller incorporating a heat pipe. There was a method (for example, refer patent document 2). However, in the device described in Patent Document 1, the thermal resistance between the transfer material and the air flow must be reduced in order to ensure sufficient cooling performance. For this purpose, it is necessary to increase the speed of the airflow or to increase the area where the transfer material and the airflow contact. Moreover, since the heat capacity of air is small, the flow rate must be increased. For this reason, it has been difficult to achieve an appropriate air flow rate with a realistic duct space or fan.

  Moreover, in the thing of patent document 2, since the contact area and contact pressure of a transcription | transfer material and a heat pipe are restricted, thermal resistance will become large in the part. Furthermore, since the thermal resistance is large at the connecting portion (usually caulking or welding) between the heat pipe roller and the radiation fin, sufficient cooling performance cannot be obtained. By the way, a liquid cooling system is mentioned as a more efficient cooling method. In the liquid cooling method, a flow path is formed at a temperature rising point, or a heat receiving part that forms the flow path is brought into close contact or in close proximity, and a coolant having a temperature lower than the temperature rising point is supplied to the flow path from the temperature rising point. It takes heat away. In general, the coolant is mainly composed of water, and propylene glycol or ethylene glycol is added to lower the freezing temperature, or a rust inhibitor (for example, phosphate-based material: phosphoric acid to prevent rusting of metal components) Potassium salt, inorganic potassium salt, etc.) are added and used.

  A configuration of a general liquid cooling device is shown in FIG. The liquid cooling device includes a configuration in which the heat receiving units 20Aa and 20Ba, the reserve tank 21, the heat radiating unit 23, and the pump 22 that are in close contact with the temperature increasing units 20A and 20B are connected via the pipe line 24. The coolant is circulated by the pump 22 and flows. By cooling the coolant heated in the heat receiving portions 20Aa and 20Ba by the heat radiating portion 23, it becomes possible to circulate a predetermined amount of coolant and perform cooling. The heat radiating part 23 is composed of a flow path formed in the good heat conduction member and fins by the good heat conduction member connected to the flow path, and cools the flow path and the fin by forced convection heat transfer using a cooling fan. As a result, the temperature of the coolant flowing in the flow path is lowered. When the coolant is water, the constant volume heat capacity is 3000 times or more that of air, and a large amount of heat can be transferred with a small flow rate, so that cooling can be performed more efficiently than forced air cooling. In addition, the heat pipe roller method increases the heat resistance of the heat dissipating part, whereas the liquid cooling can fill the cooling liquid up to the heat dissipating part 23 (radiator), so the heat resistance in the heat dissipating part 23 is reduced. be able to. Therefore, it has an excellent cooling capacity as compared with the above-described forced air cooling method and heat pipe method of Patent Document 1 and Patent Document 2. There has also been proposed a method of using a transfer material cooling device for cooling the transfer material after passing through the fixing device using the liquid cooling system. (For example, see Patent Document 3 and Patent Document 4)

In the thing of patent document 1, the cooling roller which accommodated the cooling liquid in the hollow roller is used, a cooling liquid is circulated by a pump in a heat radiating part and a cooling roller with a pump, and it fixes between a cooling roller and a counter roller. The transfer material is conveyed while sandwiching the subsequent transfer material, and the transfer material is cooled. However, since the contact area between the transfer material and the cooling roller is small, the thermal resistance is large, and even if this liquid cooling system is used, the cooling performance is not sufficient.
Moreover, in the thing of patent document 2, a film-like endless belt is stretched between the cooling part and roller which incorporate the coolant circulated through the heat radiation part with a pump, and the cooling part and the conveying roller are opposed to each other. The transfer material and the film endless belt are sandwiched between the cooling unit and the conveyance roller, and the transfer material is conveyed in a predetermined direction, and the transfer material is absorbed by the cooling unit to cool the transfer material. Is described. In the device described in Patent Document 2, the thermal resistance between the transfer material and the film endless belt can be reduced by increasing the contact portion between the film endless belt and the transfer material. However, since the film-like endless belt and the cooling part are slid, it is necessary to reduce the sliding resistance of the part, and the contact area between the film-like endless belt and the cooling part is reduced or the sliding resistance material is low. It is difficult to reduce the thermal resistance between the film-like endless belt and the cooling part. Accordingly, the heat resistance is not low over the entire heat transfer path, and sufficient cooling performance cannot be obtained. In view of the above problems, an object of the present invention is to provide a transfer material cooling device and an image forming apparatus that can realize low thermal resistance in a heat transfer path from a transfer material to a heat radiating portion.

  In order to solve the above problems, the invention described in claim 1 is a transfer material cooling device for cooling a transfer material that has passed through a fixing unit that heats and fixes a toner image on the transfer material, the fixing unit being A belt member that conveys the transfer material that has passed through the belt, and a belt cooling unit that contacts the belt member on the outer periphery and has a flow path for the cooling liquid inside to move heat of the belt member to the cooling liquid; A heat dissipating part that dissipates heat of the cooling liquid; a pump that circulates the cooling liquid; and a pipe that connects the belt cooling means, the heat dissipating part, and the pump to recirculate the cooling liquid, and The means has a plurality of the flow paths along the transfer material conveyance direction, and the direction of the cooling liquid flowing in the flow paths intersects the transfer material conveyance direction, and the cooling liquid flowing in the adjacent flow paths The directions are different from each other.

  According to a second aspect of the present invention, in the transfer material cooling device according to the first aspect of the present invention, the transfer material cooling device further includes a connecting flow path that connects the adjacent flow paths.

  According to a third aspect of the present invention, in the transfer material cooling device according to the second aspect, the connecting flow path is disposed outside the belt member.

  According to a fourth aspect of the present invention, in the transfer material cooling device according to the second or third aspect, the coolant flows from the downstream flow path to the upstream flow path via the connection flow path. It is characterized by that.

  According to a fifth aspect of the present invention, there is provided an image forming means for forming a toner image on a transfer material, a fixing means for heating and fixing the toner image formed on the transfer material on the transfer material, and the fixing 5. An image forming apparatus comprising: a transfer material cooling device that cools a transfer material conveyed from the unit. 5. The transfer material cooling device according to claim 1, wherein the transfer material cooling device is a transfer material cooling device. It is characterized by.

   ADVANTAGE OF THE INVENTION According to this invention, the transfer material cooling device and image forming apparatus which can implement | achieve low thermal resistance in the heat transfer path | route from a transfer material to a thermal radiation part can be provided.

1 is a cross-sectional view illustrating a schematic configuration of an image forming apparatus according to an embodiment of the present invention. It is sectional drawing which shows schematic structure of the transfer material cooling device of Example 1 by this invention. It is the plane schematic diagram which abbreviate | omitted the pressure roller and guide means seen from the G direction of FIG. It is sectional drawing of the endless belt member used in Example 1 by this invention. It is a perspective view of the thermal radiation part used in Example 1 by this invention. It is sectional drawing which shows schematic structure of the transfer material cooling device of Example 2 by this invention. It is sectional drawing which shows schematic structure of the transfer material cooling device of the reference example by this invention. It is sectional drawing which shows schematic structure of the transcription | transfer material cooling device of Example 3 by this invention. It is a schematic diagram which shows schematic structure of the conventional cooling device.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is a diagram showing a schematic configuration of a monochrome copying machine as an electrophotographic image forming apparatus according to an embodiment of the present invention. In the monochrome copying machine of the present embodiment, a document to be copied is optically read by the image reading device 7, the image information of the document is converted into an electrical signal, and the optical writing device according to the image information converted into the electrical signal An electrostatic latent image is written on the drum-shaped photoreceptor 2 of the image forming unit 1 by irradiating light from 5. In the image forming unit 1, a charging device 3, a developing device 4, a cleaning device 6, and a neutralizing device (not shown) are disposed around the photoreceptor 2. The charging device 3 is a contact charging method employing a charging roller, and uniformly charges the surface of the photoconductor 2 by applying a voltage in contact with the photoconductor 2. As this charging device, a non-contact charging type charging device employing non-contact scorotron charging or the like may be employed. The developing device 4 causes the toner in the developer to adhere to the electrostatic latent image on the photoreceptor 2 to form a toner image. The cleaning device 6 removes unnecessary toner on the photoreceptor 2. As the cleaning device 6, it is possible to use a blade configured such that the tip is pressed against the photoreceptor 2. The static eliminator is composed of a lamp, and initializes the surface potential of the photoreceptor 2 by irradiating light.

  In this image forming unit 1, the surface of the photoreceptor 1 rotating in the direction of arrow A is uniformly charged by the charging device 3, and the image information as described above is applied to the surface of the photoreceptor 1 thus charged. The corresponding light is emitted from the optical writing device to form an electrostatic latent image. Subsequently, toner is supplied from the developing device 4 to the toner image formed on the electrostatic latent image formed on the photoreceptor 1 in this way, and developed. The toner image formed on the photoreceptor 1 in this way is applied to a transfer material P such as paper or OHP which is biased by the transfer device 11 and conveyed from the paper supply unit 12 via the conveyance path S1. Transcribed. The toner remaining on the photoreceptor 1 after the toner image is transferred onto the transfer material P is removed by the cleaning device 6, and the charge remaining on the photoreceptor 1 is removed by the static eliminator. In this manner, a toner image is formed on the photoconductor 1 every time the photoconductor 1 rotates once.

The transfer material P onto which the toner image has been transferred is transported in the direction of the arrow along the transport path S2 and is heated and pressed by the fixing roller 8a and the pressure roller 8b of the fixing device 8 to fix the toner image on the transfer material P. . Thereafter, when recording on only one side of the transfer material P, the recording material P is discharged to the paper discharge tray 10 via the transport path S3. When recording on both surfaces of the transfer material P, the front and back sides of the transfer material P are reversed in the duplex unit 25 via the transport path S4 and transported again to the transport path S1, and the above-described process is performed again. In this embodiment, a monochrome copying machine using black toner is exemplified as the developing device 4, but a plurality of developing devices each containing color toners such as yellow, cyan, magenta, and black are used as the developing device. An image forming apparatus that forms a color image may be used. In this case, a color image may be formed by juxtaposing a plurality of image forming units 1 that form images of the respective colors along the transport path S2.
In this embodiment, in order to perform high-speed print output, the transfer material P on which the toner image is fixed by the fixing device 8 is cooled by a transfer material cooling device 9 disposed downstream of the fixing device 8 described later. , Transported to the transport path S3 or S4.

  In the transfer material cooling device 9 according to the present invention, as will be described later, a low thermal resistance can be realized in the heat transfer path from the transfer material P to the heat radiating portion. That is, in order to increase the contact area between the endless belt member that transfers the heat of the transfer material P and the transfer material P, at least two rollers are disposed in the transport direction of the transport path S2 from the fixing device 8, An endless belt member is stretched around the at least two rollers. The transfer material P that has passed through the fixing device 8 is brought into contact with the endless belt member that is stretched between at least two rollers, and the heat of the transfer material P is absorbed by the endless belt member to be cooled. I am doing so. Further, the endless belt member that has absorbed heat in this manner is transferred in the transport direction to transport the transfer material P in the transport direction, and the endless belt member heated by the transfer material P is brought into contact with the belt cooling roller. And let it cool. Further, the cooled endless belt member again passes through the fixing device 8 and comes into contact with the heated transfer material P to cool the transfer material P.

  Next, the transfer material cooling device 9 according to the present invention will be described based on examples.

  [Embodiment 1] FIG. 2 is a sectional view showing a schematic configuration of a transfer material cooling device 9 according to an embodiment 1 of the present invention. FIG. 3 is a schematic plan view of the transfer material cooling device 9 when viewed from the upper G direction in FIG. 2. In the transfer material cooling device 9 of this embodiment, the transfer material P is heated and conveyed by the fixing roller 8a rotating in the arrow B direction and the pressure roller 8b rotating in the arrow C direction on the downstream side of the fixing device 8. The endless belt member 16 is arranged in a state of being stretched between the belt cooling rollers 13 and 14 and the tension roller 15. Further, as shown in FIG. 3, the belt cooling rollers 13 and 14 are rotatably supported by bearing portions 13a1, 13a2 and 14a1, 14a2, and a gear 14c is attached to the rotating portion 14b of the belt cooling roller 14. And connected to the gear of the drive motor M that meshes with the gear 14c. Accordingly, the rotating portion 14b of the belt cooling roller 14 is rotated by the rotation drive of the drive motor M, and the endless belt member 16 stretched around the outer periphery of the rotating portion 14b together with the rotation driving of the rotating portion 14b of the belt cooling roller 14. Is transferred in the direction of arrow D. As the endless belt member 16 is transferred, the rotating portion 13b of the belt cooling roller 13 is driven to rotate.

  The rotating portions 13b and 14b of the belt cooling rollers 13 and 14 formed of a heat conductive metal such as aluminum are formed in a cylindrical shape, and the hollow portions extending in the axial direction of the rotating portions 13b and 14b are formed. The flow paths 13d and 14d through which the coolant flows are formed. As shown in FIG. 3, one end of the flow path 13d is connected to the discharge port of the radiator 23a of the heat radiating section 23 via a tube 24e via a bearing section 13a1, and the other end of the flow path 13d is connected to the bearing The tube 24a is connected to one end of the flow path 14d via the bearing portion 14a2 via the portion 13a2. Furthermore, the other end of the flow path 14d is connected to the inlet of the pump 22 that recirculates the coolant through the tube 24b via the bearing portion 14a1. Further, the discharge port of the pump 22 is connected to the inlet of the reserve tank 21 that stores the coolant by the tube 24c, and is connected to the inlet of the radiator 23a by the discharge port of the reserve tank 21 and the tube 24d. Accordingly, the coolant heated by the heat transfer from the endless belt member 16 that has flowed through the flow paths 13d and 14d of the belt cooling rollers 13 and 14 and heated by the transfer material P is moved to the reserve tank 21 by the operation of the pump 22. Then, it flows to the radiator 23a, and the radiator 23a is cooled by the cooling fan 23b and is returned to the flow paths 13d and 14d of the belt cooling rollers 13 and 14 again. Note that both end faces of the flow paths 13d and 14d of the belt cooling rollers 13 and 14 are connected to a rotary joint, and the tubes 24a, 24b and 24e are rotated even if the rotating portions 13b and 14b of the belt cooling rollers 13 and 14 rotate. It is possible to connect with.

  In this case, the liquid flows F2 and F4 of the coolant flowing in the flow paths 13d and 14d of the belt cooling rollers 13 and 14 are connected to the bearing portion 13a2 and the bearing portion 14a2 by the tube 24a so as to be opposite to each other. ing. Therefore, the cooling action of the endless belt member 16 depending on the flow direction of the coolant can be substantially uniformly cooled without being biased. F1 and F2 indicate the liquid flow directions of the cooling liquid in the tubes 24c and 24a. Further, the surface of the driving belt cooling roller 14 is an elastic body, and a pressure roller 17 is disposed at a position facing the driving belt cooling roller 14 via the endless belt member 16, and is driven via the endless belt member 16. By pressing the belt cooling roller 14, the surface of the driving belt cooling roller 14 can be deformed so as to follow the shape of the pressure roller 17. The roller members such as the belt cooling rollers 13 and 14 and the tension roller 15 are preferably made of a material having excellent thermal conductivity such as aluminum. It is also possible to form an elastic body layer having excellent thermal conductivity on the surface of the aluminum roller member.

  As shown in FIG. 4, the endless belt member 16 in this embodiment has a two-layer structure in which an aluminum metal foil layer 16b is formed on a heat-resistant polyimide layer 16a in which a heat conductive filler such as carbon black is dispersed. The aluminum metal foil layer 16b is in contact with the transfer material P, and the polyimide layer 16a is in contact with the outer periphery of the rotating portions 13b and 14b of the belt cooling rollers 13 and 14 to transfer the heat of the transfer material P to the belt cooling roller 13, Heat can be transferred to the 14 rotating parts 13b and 14b. Therefore, due to the flexibility of the polyimide layer 16a, the endless belt member 16 comes into close contact with the outer periphery of the rotating portions 13b and 14b of the belt cooling rollers 13 and 14, and the endless belt member 16 is effectively cooled by the coolant. The endless belt member 16 can be appropriately transferred. The endless belt member 16 used in the present invention is not limited to the material and structure of the present embodiment, and can transfer heat from the transfer material P to the rotating portions 13b and 14b of the belt cooling rollers 13 and 14. It is sufficient if it has sufficient thermal conductivity, and a single-layer or multi-layer endless belt made of a heat-resistant resin mixed with another metal such as copper or a heat-conductive filler such as a metal filler can also be used. is there. For example, in order to improve heat resistance, what added the silicone resin layer on the heat resistant resin layer can also be used.

  In the present embodiment, as the heat radiating portion 23, for example, one having the structure shown in FIG. 5 can be used. The heat radiating section 23 includes a radiator 23a that cools the coolant and a cooling fan 23b that takes heat away from the radiator 23a by an air flow. The radiator 23a has a corrugated fin 23d brazed around a flat flow path 23c, and the coolant flowing in from the inlet 23a1 of the radiator 23a acts on the corrugated fin 23d with an air flow (arrow E) by the cooling fan 23b. When discharged from the discharge port 23a2, the heat is taken away by the air flow, and efficient heat exchange is performed and cooled.

  Further, in this embodiment, the endless belt member 16 between the two belt cooling rollers 13 and 14 along the transfer direction D of the transfer material P and the transfer material P are brought into contact with each other so that the endless shape of the transfer material P is reached. Since it becomes easy to increase the contact area of the belt member 16, it is possible to reduce the thermal resistance. In order to achieve good heat transfer from the transfer material P to the endless belt member 16, the entire width of the transfer material P from the opposite side of the belt cooling rollers 13 and 14 with respect to the endless belt member 16 (of the belt cooling roller). A pressure roller 17 for pressing in the axial direction) and a guide means 18 for conveying and guiding the transfer material P along the conveying direction D are provided. As the guide means 18, the transfer material P is applied to the endless belt member 16 by applying static electricity to the transfer material P or blowing air toward the endless belt 16. It is desirable that the entire surface is properly pressed and held. Further, the endless belt member 16 and the belt cooling rollers 13 and 14 constitute a cooling means capable of rotating and highly efficient cooling while forming a nip. The nip between the belt cooling rollers 13 and 14 and the endless belt member 16 indicates a portion between the contact start point of the belt cooling rollers 13 and 14 and the endless belt member 16 and the separation start point. The thermal resistance between the endless belt member 16 and the belt cooling rollers 13 and 14 decreases as the nip width and nip pressure increase. In order to increase the nip width, the endless belt member 16 is wound around the belt cooling rollers 13 and 14 by a predetermined angle.

  The transfer material P that has passed through the fixing device 8 passes between the pressure roller 17 and the belt cooling roller 14 and moves to the position of the separation claw 19 while being in contact with the endless belt member 16 by the guide member 18. 19 is peeled from the endless belt member 16. During this time, the transfer material P is cooled by the endless belt member 16. In this embodiment, the transfer material temperature immediately after passing through the fixing device 8 is 100 to 105 ° C., whereas the transfer material temperature immediately after peeling from the endless belt member 16 is lowered to about 45 ° C. . As described above, in the transfer material cooling device according to this embodiment, the endless belt member 16 having good thermal conductivity is stretched between the belt cooling rollers 13 and 14 juxtaposed along the transport direction D from the fixing device 8. Then, the transfer material P heated by the fixing device 8 is brought into contact with the endless belt member 16 stretched between the belt rollers 13 and 14 to be cooled, and the endless belt member 16 heated by the transfer material P is further cooled. Is cooled by the belt cooling rollers 13 and 14, the temperature of the transfer material P can be quickly and effectively reduced.

  Further, as a transfer material cooling device according to this embodiment, instead of the pressure roller 17 and the guide device 18, a transfer material cooling device comprising another set of endless belt member 16, heat radiating portion 23, pump 22, and conduit 24 is used. It is also possible to cool the both surfaces of the transfer material P by using an apparatus and arranging the transfer material cooling devices facing each other. In the transfer material cooling device according to the present embodiment, the two belt cooling rollers 13 and 14 are used as rollers for stretching the endless belt member 16 in the conveying direction. However, the two belt cooling rollers are not necessarily provided. Instead of using, one belt cooling roller 13 or 14 may be used, and the remaining rollers may be simple stretching rollers that are not belt cooling rollers. Further, the rollers for stretching the endless belt member 16 in the conveying direction are not limited to the two stretching rollers as in the above-described embodiment, but may be three or more. In this case, all of these stretching rollers may be belt cooling rollers or simple stretching rollers. When all of these stretching rollers use simple stretching rollers, the belt cooling roller can be used as a contact roller that contacts the endless belt member as shown in Example 3 described later. .

  [Embodiment 2] FIG. 6 is a diagram showing a schematic configuration of a transfer material cooling apparatus according to Embodiment 2 of the present invention. In this embodiment, the structure of the guide means 18 is changed from the transfer material cooling device of the first embodiment. In this embodiment, five pressure rollers are installed between the belt cooling rollers 13 and 14 along the conveyance direction D of the transfer material P as the guide means 18, and these pressure rollers 181 to 185 are used. The transfer material P is conveyed and guided in the conveyance direction D, and the transfer material P is pressed against the surface of the endless belt member 16 so that the heat of the transfer material P can be effectively transmitted to the endless belt member 16. Thus, when the transfer material P is guided and conveyed by the plurality of pressure rollers 181 to 185, the transfer material P can be brought into contact with the endless belt member 16 in a more closely contacted state. It becomes possible to cool the transfer material P more effectively.

  [Reference Example] FIG. 7 is a diagram showing a schematic configuration of a transfer material cooling device of a reference example according to the present invention. In this reference example, the transfer material cooling device of Example 1 described above uses only one belt cooling roller 26 and is made of metal along the conveyance direction D as a transfer means for the endless belt member 16. The driving roller 151 and the driven roller 152 are disposed, tension is applied by the tension roller 153, and the endless belt member 16 is stretched. The belt cooling roller 26 is disposed between the tension roller 153 and the driving roller 151 so as to hang around the outer periphery of the rotating portion 26 b of the belt cooling roller 26 and to contact the endless belt member 16.

  In this case, the belt cooling roller 26 rotates along with the transfer of the endless belt member 16, and the coolant flows in the hollow channel 26 d formed in the axial direction of the rotating portion 26 b so that the endless belt 16 is moved. Cooling. Further, the surface of the drive roller 151 is an elastic body, and a pressure roller 17 is disposed at a position facing the roller member and the endless belt member 16 so as to press the drive roller 151 via the endless belt member 16. Thus, the surface of the drive roller 151 can be deformed so as to follow the shape of the pressure roller 17. The roller members such as the driving roller 151, the driven roller 152, the tension roller 153, and the belt cooling roller 26 are preferably made of a material having excellent thermal conductivity such as aluminum. It is also possible to form an elastic body layer having excellent thermal conductivity on the surface of the aluminum roller member.

  [Embodiment 3] FIG. 8 is a diagram showing a schematic configuration of a transfer material cooling apparatus according to Embodiment 3 of the present invention. In this embodiment, the structure of the guide means 18 is changed from the transfer material cooling device of the first embodiment. In this embodiment, a large-diameter pressure roller 186 is used instead of the pressure roller 17 and the guide means 18 used in the first embodiment. The transfer material P that has passed through the fixing device 8 passes between the large-diameter roller 186 and the endless belt member 16 and moves to the position of the separation claw 19 while contacting the endless belt member 16. The belt member 16 is peeled off. By using such a large-diameter pressure roller 186, there is an advantage that the number of parts can be reduced.

  DESCRIPTION OF SYMBOLS 1 Image forming unit 2 Photoconductor 3 Charging device 4 Developing device 5 Optical writing device 6 Cleaning device 7 Image reading device 8 Fixing device 8a Fixing roller 8b Pressure roller 9 Transfer material cooling device 11 Transfer device, 13, 14, 26 Belt cooling roller, 13a1, 13a2, 14a1, 14a2 Bearing part, 13b, 14b, 26b Rotating part, 13d, 14d, 26d Flow path, 15, 153 Tension roller, 16 Endless belt member , 17 Pressure roller, 18 Guide means, 19 Separation claw, 21 Reserve tank, 22 Pump, 23 Heat radiating part, 23a Radiator, 23b Cooling fan, 24a, 24b, 24c, 24d, 24e Tube (pipe), 151 Drive roller , 152 Driven roller, 181 to 185 Pressure roller, 186 Large aperture Pressure roller, D conveyance direction

JP 2005-227454 A JP 2003-241623 A JP-A-2005-298109 JP 2005-349627 A

Claims (5)

A transfer material cooling device that cools a transfer material that has passed through a fixing unit that heats and fixes a toner image on the transfer material,
A belt member that conveys the transfer material that has passed through the fixing unit;
Belt cooling means that contacts with the belt member at the outer periphery, and has a flow path for cooling liquid inside, and moves heat of the belt member to the cooling liquid;
A heat dissipating part for dissipating the heat of the coolant,
A pump for circulating the coolant;
A conduit for connecting the belt cooling means, the heat radiating portion and the pump to recirculate the coolant;
With
The belt cooling means has a plurality of the flow paths along the transfer material conveyance direction,
The transfer material cooling device, wherein the direction of the cooling liquid flowing in the flow path intersects the transfer material conveyance direction, and the directions of the cooling liquid flowing in the adjacent flow paths are different from each other. The transfer material cooling device according to claim 1,
A transfer material cooling device having a connecting channel for connecting between the adjacent channels. The transfer material cooling device according to claim 2,
The transfer material cooling device, wherein the connection channel is disposed outside the belt member. In the transfer material cooling device according to claim 2 or 3,
The transfer material cooling apparatus, wherein the coolant flows from the downstream flow path in the transfer material conveyance direction to the upstream flow path via the connection flow path.   Image forming means for forming a toner image on the transfer material, fixing means for heating and fixing the toner image formed on the transfer material onto the transfer material, and cooling the transfer material conveyed from the fixing means An image forming apparatus comprising: a transfer material cooling device that performs transfer material cooling, wherein the transfer material cooling device is the transfer material cooling device according to any one of claims 1 to 4.

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