JP5557098B2 - Cooling device and image forming apparatus - Google Patents

Description

  The present invention relates to a cooling device used in an image forming apparatus such as a printer, a facsimile machine, and a copying machine, and an image forming apparatus provided with the cooling device.

  2. Description of the Related Art As an image forming apparatus, an apparatus that forms a toner image on a sheet-like sheet using electrophotographic technology and melts and fuses the toner by passing through a thermal fixing device is known. In general, the temperature of the heat fixing device varies depending on the type of toner and paper, the paper conveyance speed, and the like, but is set and controlled at a temperature of about 180 [° C.] to 200 [° C.] to fuse the toner instantaneously. The surface temperature of the paper immediately after passing through the heat fixing device is a high temperature of about 100 [° C.] to 130 [° C.] although it depends on the heat capacity (specific heat, density, etc.) of the paper. Since the melting temperature of the toner is lower, the toner is slightly soft at the time immediately after passing through the heat fixing device, and remains in a sticky state for a while until the paper cools down. Therefore, when the image output operation is repeated continuously and the paper after passing through the heat fixing device is stacked in the paper discharge container, if the toner on the paper cannot be sufficiently cured and is in a soft state, the toner on the paper A so-called blocking phenomenon that sticks to another sheet may occur, and the image quality may be significantly reduced.

  In the image forming apparatus described in Patent Literature 1, a cooling device including a cooling roller that is rotatably supported by a bracket via a bearing and that cools the paper while contacting the paper and transporting the paper is more paper than the thermal fixing device. It is provided on the downstream side in the transport direction. The paper after passing through the heat fixing device is cooled by the cooling roller of the cooling device, so that the toner on the paper is cooled and hardened, and the occurrence of the blocking phenomenon can be suppressed. In addition, the cooling roller has a tubular structure, and the cooling liquid flows into the cooling roller from one end side to the other end side in the axial direction of the cooling roller. To be cooled.

  In recent years, there has been an increasing need for light printing such as high-speed printing such as telephone bills and receipts, and printing of color glossy images on cardboard, coated paper, and the like. In such a light printing, a large amount of printing is performed at a high speed, and thus it is necessary to cool a high-temperature sheet-like member in a shorter time. In addition, unlike office use, color printing is frequently performed and glossy images are also frequently used. Therefore, high-efficiency cooling has been demanded in order to fix images at a high temperature with a thermal fixing device.

  However, if the coolant is simply flowed into the cooling roller, the temperature of the coolant near the inner wall surface of the cooling roller becomes too high, and the cooling roller cannot be cooled effectively by the coolant. This may cause a problem that the sheet cannot be properly cooled.

  The present invention has been made in view of the above problems, and an object thereof is to provide a cooling device and an image forming apparatus capable of improving the cooling efficiency of a sheet-like member by a cooling roller.

In order to achieve the above object, the invention of claim 1 comprises a cooling roller made of a hollow tubular member, and a cooling medium conveying means for conveying the cooling medium into the tubular member, and a sheet is provided on the cooling roller. In the cooling device that cools the sheet-like member by bringing the sheet-like member into contact with each other, the inner member is included in the tubular member, and a cooling medium is provided between the inner wall surface of the tubular member and the outer peripheral surface of the inner member. are channel through the formation, the turbulence generating means for generating turbulence in the cooling medium, the area of the sheet-like member approximately the same width, wherein the tubular member of the outer peripheral surface is cooled by contact of the encapsulating member It is characterized by providing .
Further, those of invention of claim 2, a cooling device according to claim 1, wherein said turbulence generating means, characterized in that it is a protrusion or groove of the spiral shape provided on the outer peripheral surface of the enclosing member It is.
Further, the invention of claim 3, a cooling device according to claim 1, wherein said turbulence generating means is characterized in that a hole provided in the outer peripheral surface of the enclosing member.
According to a fourth aspect of the present invention, there is provided the cooling device according to the first aspect , wherein the turbulent flow generating means is an uneven surface or a roughened surface provided on the outer peripheral surface of the inner member. It is.
The invention of claim 5, claim 1, a cooling apparatus 4 according were 3 or, the enclosed member is core member, the outer periphery of the core member provided with the turbulence generating means It has a flow path through which a cooling medium flows in a gap formed by the surface and the inner wall surface of the tubular member.
The invention of claim 6, claim 2, 3 or is a cooling device according 4, the enclosed member is an inner tube of the tubular structure than the upper Symbol tubular member, said tubular member outer channel which a cooling medium flows between the inner tube, and that the double pipe structure having an inner passage through said inner tube cooling medium is formed between the inner pipe and the tubular member It is a feature.
The invention of claim 7, claim 1, 3 or is a cooling device according 4, the enclosed member is a cylinder having a hollow cooling medium can pass into the interior, the turbulence A flow path through which a cooling medium flows is formed in a gap formed by the outer peripheral surface of the cylinder provided with the generating means and the inner wall surface of the tubular member.
The invention of claim 8, claim 1, 2, 3, 4, a cooling device 7 described was 6 or, the turbulence generating means further separate from the above-mentioned enclosed member A cooling device, wherein the cooling device is formed on a body member, and the separate member is attached to an outer peripheral surface of the inner packaging member.
According to a ninth aspect of the present invention, there is provided a toner image forming means for forming a toner image on a sheet-like member, and a heat fixing means for fixing the toner image formed on the sheet-like member to the sheet-like member at least by heat. And a cooling unit that cools the sheet-like member on which the toner image is fixed by the thermal fixing unit, wherein the cooling unit is the first, second, third, fourth, fifth, sixth, or seventh. Alternatively, the cooling device described in 8 is used.

  In the present invention, the flow of the cooling medium flowing through the flow path formed between the inner wall surface of the tubular member and the outer peripheral surface of the inner member becomes turbulent by the turbulent flow generating means provided on the outer peripheral surface of the inner member. . Thereby, replacement of the cooling medium having a high temperature in the vicinity of the inner wall surface of the tubular member and the cooling medium having a low temperature at a position away from the inner wall surface is actively performed. Therefore, the temperature of the cooling medium in the vicinity of the inner wall surface can be lowered as compared with the case where the turbulent flow generation means is not provided on the outer peripheral surface of the inner member, and accordingly, the tubular member can be effectively cooled by the cooling medium. it can. Therefore, the cooling efficiency of the sheet-like member by the cooling roller made of a tubular member can be improved.

  As mentioned above, according to this invention, there exists the outstanding effect that the cooling efficiency of the sheet-like member by a cooling roller can be improved.

FIG. 3 is an enlarged cross-sectional view of a cooling roller according to Configuration Example 1. The schematic block diagram of the cooling device which concerns on embodiment. 3 is a schematic diagram of a cooling roller according to Configuration Example 1. FIG. The expanded sectional view of the cooling roller by which the spiral groove | channel was provided in the outer peripheral surface of the core included in the sleeve. FIG. 6 is an enlarged cross-sectional view of a cooling roller according to Configuration Example 2. FIG. 6 is an enlarged cross-sectional view of a cooling roller according to Configuration Example 3. FIG. 9 is an enlarged cross-sectional view of a cooling roller according to Configuration Example 4. FIG. 9 is an enlarged cross-sectional view of a cooling roller according to Configuration Example 5. The expansion schematic diagram of a separate member of a thin plate-shaped round hole type. The expansion schematic diagram of a separate member of a thin plate-shaped long hole type. The expansion schematic diagram of the separate member of a rectangular type of a thin wire net. The expansion schematic diagram of the separate member of a fine wire net-like rhombus type. FIG. 10 is an enlarged cross-sectional view of a cooling roller according to Configuration Example 6. FIG. 10 is an enlarged cross-sectional view of a cooling roller according to Configuration Example 7. FIG. 10 is an enlarged cross-sectional view of a cooling roller according to Configuration Example 8. 1 is a schematic configuration diagram of an image forming apparatus according to an embodiment.

  A cooling roller and a cooling device according to an embodiment of the present invention will be described using an image forming apparatus in which toner on a sheet, which is a sheet-like member, is fixed by a thermal fixing device. However, the cooling roller and the cooling apparatus of the present invention are not limited to those used in the image forming apparatus, and can be applied to any apparatus that needs to cool the sheet-like member.

  FIG. 2 is a schematic configuration diagram of an example of the cooling device 18 provided with the cooling roller 20 of the present invention that also functions as paper conveyance. The cooling roller 20 as a cooling means has a tubular structure, and cools the surface of the cooling roller by flowing and circulating a cooling liquid therein. The cooling device 18 having the cooling roller 20 is disposed in the paper conveyance path immediately after the heat fixing device, and the paper is conveyed by the cooling roller 20 and simultaneously brought into contact with it to remove heat from the paper and cool it.

  The cooling device 18 is provided with a roller 140 and a roller 141 arranged at intervals in the conveyance direction (left-right direction) of the sheet P, which is a sheet-like member, and the conveyance belt 142 for conveying the sheet is a roller. 140 and a roller 141. The roller 140 is a driving roller that rotationally drives the conveying belt 142 by a driving force from a driving source (not shown), and rotates the conveying belt 142 in the counterclockwise direction in the drawing to carry the paper P carried on the conveying belt 142. Is transported from the right side to the left side in the figure.

  A thermal fixing device 16 is disposed upstream of the cooling device 18 in the paper conveyance direction, and a paper discharge accommodating portion 17 is disposed downstream of the cooling device 18 in the paper conveyance direction. Above the roller 141, an upper guide 143 for guiding the paper P conveyed from the heat fixing device 16 is provided. Further, the cooling roller 20 is pressed against the conveying belt 142 from above so as to bite into the conveying belt 142 at an intermediate position between the rollers 140 and 141, and the cooling roller 20 uses the conveying force of the conveying belt 142. It is designed to rotate around. Reference numeral 44 in the drawing is a bracket that constitutes the main body of the cooling device 18, and is a member that supports components such as the roller 140, the roller 141, the cooling roller 20, and the upper guide 143 in a fixed or rotatable manner. The cooling device 18 is unitized by the bracket 144 and incorporated in the image forming apparatus main body.

  The paper P heated to a high temperature by the heat fixing device 16 that fixes the toner on the paper P to the paper P by heat and pressure passes through the cooling device 18 before being discharged to the paper discharge accommodating portion 17. Specifically, the sheet P that has become hot through the heat fixing device 16 enters between the upper guide 143 and the roller 141 of the cooling device 18 and is carried by the conveying belt 142, and then the cooling roller 20 and the conveying belt 142. The sheet passes through the nip region formed in step, and is discharged to the sheet discharge container 17. The inside of the cooling roller 20 has a pipe structure, and the cooling liquid sufficiently cooled outside is supplied into the cooling roller 20 and circulated through the cooling roller 20, and then the cooling liquid is discharged from the cooling roller 20. Since the sheet P passes through the nip region formed by the contact between the cooling roller 20 and the conveying belt 142 while being in close contact with the cooling roller 20, the heat of the sheet P is absorbed by the cooling roller 20 at that time. P is sufficiently cooled. For example, when the surface temperature of the paper P immediately after passing through the heat fixing device 16 is about 100 [° C.], the paper P is passed through the cooling device 18, so that the surface temperature of the paper P is 50 [° C.] to 60 [° C.]. [° C.].

  As will be described later, the cooling roller 20 communicates / connects with a coolant circulation means such as the radiator 103 equipped with the tank 101, the pump 100, and the cooling fan 104 via the rotary pipe joint means, and the enclosed coolant is circulated. Then, the cooling roller 20 is cooled (see FIG. 16 and the like).

  Here, in the electrophotographic image forming apparatus, the high-temperature paper on which the toner is fixed by the heat fixing device causes curling or the toner is not completely solidified. Since the toner adheres to the toner and the image quality is remarkably deteriorated, the paper must be cooled.

  Conventionally, in an electrophotographic image forming apparatus for offices, in order to cool high-temperature paper, a cooling fan is used to directly cool the top and bottom surfaces of the paper, or a cooling fan is used to cool the end. Many methods have been adopted in which a sheet is brought into contact with a pipe roller to cool the sheet.

  However, in recent years, electrophotographic image forming apparatuses have been increasingly demanded for light printing, such as high-speed printing such as telephone bills and receipts, and printing of color glossy images on cardboard and coated paper. It was. In light printing by such an electrophotographic image forming apparatus, a large amount of printing is performed at high speed, and thus it is necessary to cool a high-temperature paper in a shorter time. Also, unlike office use, color printing is more frequent and glossy images are more frequent. Therefore, the fixing unit fixes toner on paper at a higher temperature, so cooling that is more efficient than the conventional method is required. It was.

  Therefore, a liquid cooling method has started to be proposed in which circulating cooling liquid having higher cooling efficiency than the above-described cooling fan and heat pipe roller is passed through a hollow cooling roller, and the high-temperature paper is cooled by the cooling roller.

  In order to efficiently reduce the temperature of the sheet, it is necessary to increase the heat flux from the sheet to the cooling liquid across the wall of the cooling roller. Here, the heat flux between the wall portion of the cooling roller and the coolant is the number by convective heat transfer from "JP Hallman Heat Transfer Engineering <Top> (Brain Book Publishing), P11-12". It is expressed as 1.

ただし、
Ｗ［Ｗ］：熱流束
ｈ［Ｗ／ｍ^２・℃］：冷却ローラ内壁面の熱伝達率
Ａ［ｍ^２］：冷却ローラ内壁面積
Ｔｒ［℃］：冷却ローラ内壁面温度
Ｔｗ［℃］：液温（冷却ローラ内壁面より十分離れた位置）

However,
W [W]: Heat flux h [W / m ² · ° C.]: Heat transfer coefficient A [m ² ] of the cooling roller inner wall surface: Cooling roller inner wall area Tr [° C.]: Cooling roller inner wall surface temperature Tw [° C.]: Liquid temperature (position sufficiently away from the inner wall of the cooling roller)

  From Equation 1, in order to increase the heat flux W, it is necessary to lower the liquid temperature Tw, increase the inner wall area A of the cooling roller, or improve the heat transfer coefficient h of the inner wall surface of the cooling roller.

  In order to increase the heat flux W in Equation 1, changing the fluid flowing inside the cooling roller from air to cooling liquid to increase the thermal conductivity and specific heat, or increasing the speed of the fluid inside the cooling roller, This corresponds to increasing the heat transfer coefficient h of the inner wall surface of the cooling roller. However, increasing the fluid velocity is not easy because it imposes a heavy burden on the pump for supplying the coolant to the inside of the cooling roller.

  In addition, the heat flux W can be increased by lowering the liquid temperature Tw in Equation 1, but when a cooling fan and a radiator are used as means for lowering the liquid temperature Tw, the liquid temperature Tw is essential. Since the liquid temperature Tw cannot be lowered below room temperature, the liquid temperature Tw does not decrease as much as expected. In addition, when a refrigerator is used as a means to lower the liquid temperature Tw, the liquid temperature Tw is lowered below room temperature, but the power consumption of the refrigerator and the initial investment cost are increased, which is realized from the viewpoint of energy saving and cost reduction. Is not easy.

  Therefore, in the present embodiment, the cooling efficiency of the paper P by the cooling roller 20 is improved while suppressing the occurrence of these problems.

  Next, the cooling roller 20 according to this configuration example will be described with reference to FIG. As shown in FIG. 3, the cooling roller 20 of this configuration example has a tube structure composed of a sleeve 1 and a core 2, and the sleeve 1 is rotatably supported by a bearing 123, and is formed by the sleeve 1 and the core 2. In this configuration, the cooling liquid flows through the flow path 116, which is a narrow gap.

  In FIG. 3, the cooling liquid cooled by the cooling liquid circulation device 500 as shown in FIG. 16 is supplied to the cooling roller 20 from the supply port 118 of the rotary joint 120 serving as the rotary pipe joint means. The flow path 116 in the cooling roller 20 has a narrow structure so as to pass water near the inner peripheral surface of the sleeve 1. The coolant that has flowed through the flow path 116 in the sleeve 1 is discharged from the discharge port 119 of the rotary joint 121.

  A cooling roller having a tube structure including an outer tube such as a sleeve and an inner member included in the outer tube has been conventionally used. The purpose of the cooling roller is a gap between the inner wall surface of the outer tube and the outer peripheral surface of the inner member. By narrowing the flow path formed by, the flow rate of the coolant is increased without relying on the pumping ability of the pump, and the heat transfer coefficient is improved as compared to the cooling roller in which the inner member is not included in the outer tube. It is in.

  However, in the case of such a roller configuration, if the flow path (gap) is not extremely narrow, a difference occurs in the flow velocity between the vicinity of the outer peripheral surface of the inner member and the inner wall surface of the outer tube, and cooling that flows through the flow path There is a drawback that the temperature of the liquid is different in the radial direction of the cooling roller.

  Fluid simulation analysis confirms that the flow velocity is slower near the inner wall surface of the outer tube than the vicinity of the outer surface of the inner member when the gap between the channels is wide. However, the coolant temperature in the vicinity of the inner wall surface of the outer tube is increased, the efficiency of heat transfer from the inner wall surface of the outer tube to the coolant is poor, and the temperature of the outer tube is difficult to decrease. Therefore, it is necessary to make the flow path extremely narrow so as to eliminate as much as possible the flow velocity difference between the vicinity of the outer peripheral surface of the inner member and the inner wall surface of the outer tube, but the flow path (gap) is said to be extremely narrow. This is because the outer diameter of the inner packaging member is made as close as possible to the inner diameter of the outer tube, so that the cooling roller is not a tube but a solid metal bar, which is very heavy. In addition, the assembly operation for inserting the enclosing member into the outer tube is also difficult because it may come into contact with each other due to the narrow interval and may be scratched.

  Therefore, in the present embodiment, the heat transfer efficiency can be increased, and the weight can be reduced and the assembly workability can be improved even if the flow path is not set to an extremely narrow interval. In other words, the heat transfer coefficient is improved while allowing a certain amount of space between the flow paths.

  Specifically, the cooling roller 20 is composed of a sleeve 1 that is an outer tube and a core 2 that is an inner member that is long in the axial direction of the cooling roller and has an outer diameter smaller than the inner diameter of the sleeve 1. The cooling fluid flow path interval that is a cooling medium formed between the core 2 and the core 2 is allowed to have a margin, and a turbulent flow is generated in the fast flow of the coolant flowing in the vicinity of the core 2 Due to the generated turbulent flow, the coolant near the outer peripheral surface of the core 2 and the coolant near the inner wall surface of the sleeve 1 are mixed together, and the coolant near the inner wall surface of the sleeve 1 is made uniform by making the coolant temperature in the flow path substantially uniform. The temperature is lowered.

  As a method for generating turbulent flow, a turbulent flow generating means having a minute shape as described later is provided on the outer peripheral surface of the core 2, and a fast flow near the outer peripheral surface of the core 2 is used. Even if the turbulent flow generating means has a minute shape, the generated turbulent flow is small and strong as long as the flow velocity flowing therethrough is fast. Furthermore, by providing a large number of turbulent flow generating means, even if small, a strong turbulent flow is generated in the vicinity of the outer peripheral surface of the core 2. Then, the low-temperature coolant near the outer peripheral surface of the core 2 is lifted up by a turbulent flow (image of sand dust rolling up and soaring), and mixed with the high-temperature coolant near the inner wall surface of the sleeve 1.

  In addition, regarding the flow path gap formed by the inner wall surface of the sleeve 1 and the outer peripheral surface of the core 2, the narrower the flow rate is, the faster the flow velocity becomes, and the vicinity of the outer peripheral surface of the core 2 and the sleeve 1 are increased. There is no difference in flow velocity from the vicinity of the inner wall surface, and the heat transfer rate from the inner wall surface of the sleeve 1 to the coolant is improved, but there are also problems (weight, assembly workability). On the other hand, if the flow passage gap formed by the inner wall surface of the sleeve 1 and the outer peripheral surface of the core 2 has an excessive margin (too wide), the core 2 must have a large turbulent flow unless the turbulent flow generating means causes a large turbulent flow. It becomes difficult to stir the coolant in the vicinity of the outer peripheral surface and the vicinity of the inner wall surface of the sleeve 1. In order to generate a large turbulent flow, a turbulent flow generating means having a large shape is required. Therefore, the fluid resistance due to the turbulent flow generating means inevitably increases, and a load is applied to the pump that feeds the cooling liquid into the cooling roller. It will be.

  Therefore, in order to avoid the problem of the channel gap being too narrow or too wide, the channel gap is narrowed to such an extent that the weight and assembly workability do not matter, and the turbulent flow generating means is made into a minute shape, and further the turbulent flow A large number of turbulent flow generating means are provided so that the cooling liquid is mixed while suppressing fluid resistance.

  Here, although it differs from the structure which provides a turbulent flow generation means in the core 2 which is an inclusion member like the cooling roller 20 provided in the cooling device 18 of this embodiment, the cooling described in JP-A-2006-003819 is disclosed. In the apparatus, fins, which are spiral partition plates, are provided on the wall surface without the cooling roller, and the difference between the cooling apparatus 18 of the present embodiment and the cooling apparatus described in JP-A-2006-003819 will be described. .

  In order to clarify the difference from the cooling device described in Japanese Patent Laid-Open No. 2006-003819, the turbulent flow generating means provided on the outer peripheral surface of the core 2 included in the sleeve 1 of the cooling roller 20 of this embodiment is small. The case where a spiral projection is used will be described. Also, the spiral winding direction of the protrusion is set to a winding direction in which a feed in the same direction as the flow direction of the coolant fed into the cooling roller 20 by the pump is generated so that the fluid resistance does not increase. In JP-A-2006-003819, the winding direction of the spiral fin is not specified, but from the contents described in paragraph No. 0048 of JP-A-2006-003819, the fin is in the same direction as the liquid flow. It can be read that this is the winding direction in which the feed occurs.

  Although the cooling device according to the present embodiment and the cooling device described in Japanese Patent Application Laid-Open No. 2006-003819 are similar to the provision of the spiral protrusion in the cooling roller, the purpose and the purpose are achieved. Therefore, there is a great difference in the location where the projections (partition plates) are provided, the size and number of the projections, and the effects. In the cooling device described in Japanese Patent Application Laid-Open No. 2006-003819, the fin provided on the inner wall surface of the tubular cooling roller increases the roller inner wall area to increase the contact area with the cooling medium, and the fin accompanying the rotation of the cooling roller. The spiral motion is positively generated by the spiral motion to cause a fast flow in the spiral direction along the inner wall surface of the roller, thereby improving the heat transfer rate from the inner wall surface of the cooling roller to the cooling medium.

  However, to satisfy both of these conditions, the fins provided on the inner wall surface of the cooling roller must have a large protrusion shape. However, the large fins cause large fluid resistance as described above, and the pump feed You will have to rely on liquid capacity to solve the problem.

  Here, the cooling roller disclosed in Japanese Patent Application Laid-Open No. 2006-003819 corresponds to the sleeve 1 that is the outer tube in the present embodiment. Therefore, when only a small spiral protrusion is provided on the sleeve 1 of the present embodiment. When the flow of the cooling liquid near the inner wall surface of the sleeve 1 is slower than the vicinity of the outer peripheral surface of the core 2, it is assumed that the turbulent flow generated near the inner wall surface of the sleeve 1 is weak with a small spiral protrusion. Of course, it is difficult to stir the coolant in the flow path formed between the inner wall surface of the sleeve 1 and the outer peripheral surface of the core 2. Therefore, in this embodiment, the core 2 that is the inner member is included in the sleeve 1 that is the outer tube, and a small spiral protrusion is provided on the core 2 as the turbulent flow generation means. Even if the turbulent flow generating means is a small protrusion, if the fast flow in the vicinity of the outer peripheral surface of the core 2 is used, the whole coolant in the flow path can be stirred.

  In the case of the present embodiment, as a method of increasing the heat flux W of Equation 1, the roller inner wall area is not obtained or a fast flow is generated in the spiral direction. First, the core, which is an inner member, is included in the sleeve 1, which is the outer tube, and the flow passage gap through which the coolant flows is narrowed to some extent, and the flow velocity flowing therethrough is increased. This alone improves the heat transfer coefficient, but in the present embodiment, a small spiral protrusion is provided on the outer peripheral surface of the core 2 in consideration of a reduction in fluid resistance, and the flow around the outer peripheral surface of the core 2 is fast. A turbulent flow is caused by the flow of the cooling liquid and a small spiral-shaped protrusion, and the cooling liquid near the inner wall surface of the sleeve 1 that is stagnant and stagnant due to the stirring action by the turbulent flow (warmed by stagnation) The cooling medium) and the cooling liquid in the vicinity of the outer peripheral surface of the core 2 (a cooled cooling liquid that flows without stagnation), in which a new cooling liquid is sent one after another, are mixed. Since the turbulent effect is added to the increase in the flow velocity, the heat transfer rate is synergistically improved, and the temperature of the paper P can be further reduced.

  In short, in this embodiment, a large number of small-sized turbulent flow generating means are provided on the outer peripheral surface of the core 2 to generate strong turbulent flow even if small everywhere, thereby increasing the heat flux W and fluid resistance. I try to suppress it.

  If a large fin is provided on the inner wall surface of the cooling roller as in the cooling device described in Japanese Patent Application Laid-Open No. 2006-003819, naturally, not only a fast flow is generated in the spiral direction, but also the entire coolant in the roller is stirred at once. Can be made. However, as described above, since a large fluid resistance is involved, a countermeasure such as a pump is required, and the heat transfer rate by stirring is improved, but it also has a large demerit.

  Therefore, the present applicants studied the configuration of the cooling roller that can improve the heat transfer coefficient and suppress the fluid resistance by fluid simulation. As a result, as described above, first, the flow rate is increased by narrowing the flow path by the inclusion member, and the turbulent flow generating means having a small shape in consideration of fluid resistance on the outer peripheral surface of the inclusion member, such as a protrusion or a groove, etc. If a large number of small turbulent flows are generated near the outer peripheral surface of the inclusion member, the turbulent flow is entangled and changed in a complex manner, and is spread and synergistically. It was found that the coolant near and the coolant near the inner wall surface of the sleeve were mixed. That is, it was found that if a large number of small protrusions and grooves are provided in a region where the flow velocity is high, the stirring function is sufficiently effective, which contributes to an improvement in heat transfer coefficient. If the cooling roller 20 as in the present embodiment is used, it is possible to achieve both suppression of fluid resistance and stirring action of the cooling liquid, and it is possible to improve the heat flux W by increasing the heat transfer rate without depending on the pump. become.

  The turbulent flow generating means provided on the outer peripheral surface of the core 2 included in the sleeve 1 of the cooling roller 20 of the present embodiment has been described by taking a spiral protrusion as an example, but it is considered that the fluid resistance does not increase. For example, the size, shape and configuration of the turbulent flow generation means are not limited.

[Configuration example 1]
In FIG. 1, the inclusion member described above is the core 2, and a narrow flow path gap is formed between the sleeve 1 and the core 2, and a small spiral projection 21 as a turbulent flow generating means is formed on the outer peripheral surface of the core 2. It is the schematic when providing.

  The cooling medium flows from the left side to the right side of the flow path gap (the left side is upstream and the right side is downstream), and both the sleeve 1 and the core 2 are rotating clockwise as viewed from the downstream axial direction. A turbulent flow is generated in the flow in the vicinity of the outer peripheral surface of the core 2 by the spiral projection 21, and the heat transfer rate can be improved by the turbulent flow effect and the flow rate increasing effect by the narrow channel.

  The spiral protrusion 21 also rotates to the right along with the core 2 that rotates to the right. At this time, the winding direction of the spiral protrusion 21 is a right-hand winding in which the feed in the same direction as the flow direction of the cooling medium occurs. . If the winding direction is the same as the flow direction of the cooling medium, the fluid resistance can be further reduced because the cooling medium flows smoothly while turning.

  Since the protrusion 21 which is a turbulent flow generation means of the present configuration example is not intended to increase the spiral movement of the coolant and the area of the outer peripheral surface of the core 2, the protrusion 21 of FIG. Compared with the case where it aims at earning the spiral movement and the area of the outer peripheral surface of the core 2, the magnitude | size shape can be made remarkably small. In addition, since the size of the protrusion 60 is smaller than the protrusion provided on the outer peripheral surface of the core 2 for the purpose of increasing the area of the outer peripheral surface of the core 2 and the positive spiral movement of the coolant, A larger number of protrusions 21 are provided on the outer peripheral surface of the core 2 than when the protrusions are provided on the outer peripheral surface of the core 2 for the purpose of positive spiral movement of the coolant and the area of the outer peripheral surface of the core 2.

  In the case of FIG. 1, this is equivalent to providing a large number of pseudo-pitch intervals with a fine spiral pitch interval. The smaller the shape of the protrusion 21, the more advantageous for the fluid resistance. However, in order to reduce the shape, it is necessary to make the helical pitch interval fine. However, if the spiral pitch interval is too small, the generated turbulent flow is also reduced and the stirring force of the cooling liquid due to the turbulent flow is weakened, so it must be determined in consideration of the balance with the fluid resistance. That is, not only the protrusions 21 but also the turbulent flow generation means in general, the appropriate configuration, size, shape, and number thereof cannot be specified, so the size (diameter) of the sleeve 1 and the cooling liquid It is necessary to determine in a timely manner the factors that influence the heat flux W of the above formula 1 such as the flow rate and the flow velocity as parameters. That is, for each apparatus configuration, the designer considers the system balance so as to achieve high cooling performance, verifies and confirms by simulation and trial experiment evaluation, and finally, an appropriate configuration of the turbulent flow generation means such as the protrusion 21 The shape will be decided.

  In the simulation conducted by the present applicants, for example, the turbulent flow provided on the outer peripheral surface of the core 2 when the inner diameter φ30 [mm] of the sleeve 1 and the outer diameter φ24 [mm] of the core 2, that is, the flow path gap 3 [mm]. In the case where the generating means is a spiral protrusion 21, although depending on the flow rate and flow rate of the coolant, the height of the protrusion 21 is about 1.2 [mm] and the spiral pitch interval is about 5 [mm]. The balance between resistance and cooling performance was good. Moreover, although a simulation was attempted even when a large spiral protrusion (height from the outer peripheral surface of the core 2 [2.5 mm], helical pitch interval 10 [mm]) was provided on the outer peripheral surface of the core 2, The resistance becomes very large, and the coolant flowing through the cooling roller 20 (sleeve 1) does not have a desired flow rate unless the pump having the liquid feeding capacity several times that of the above-described configuration is used, and the cooling performance is deteriorated. As a result.

  FIG. 4 is a schematic view when the spiral projection 21 of FIG. As a result of trying the simulation with the spiral groove 23, the fluid resistance became very small, but the magnitude and strength of the generated turbulent flow did not reach the protrusion 21 in FIG. However, since the projection shape is not as shown in FIG. 1, the gap between the channels can be made narrower than in the case of FIG. 1, and the amount of turbulent flow that becomes smaller and weaker can be compensated for by increasing the flow velocity. In addition, since the fluid resistance is small, it can be said that the configuration is suitable for a case where a pump with a small power has to be used, or when it is desired to increase the flow rate or flow rate of the coolant.

  Further, in the case of the cooling roller 20 configured by the sleeve 1 and the core 2 of this configuration example, the fluid is generated along with the generation of turbulent flow by rotating the sleeve 1 and the core 2 in synchronization in the same direction as described above. Resistance can be suppressed.

  On the other hand, the rotation speed and the rotation direction of the sleeve 1 and the core 2 may be different. As a result, the swirl speed component of the coolant is greatly different between the vicinity of the inner wall surface of the sleeve 1 and the vicinity of the outer peripheral surface of the core 2, and the heat transfer rate from the inner wall surface of the sleeve 1 to the coolant is increased by promoting turbulence. improves. As the rotation of the core 2 is different from the number of rotations of the sleeve 1, such as, for example, the number of rotations several times that of the sleeve 1 or, on the contrary, stationary and non-rotation, the effect can be obtained. If the maximum effect is desired, the core 2 may be rotated in the direction opposite to the rotation direction of the sleeve 1. Further, in this configuration example, since the turbulent flow is amplified by the spiral projection 21 which is a turbulent flow generating means provided on the outer peripheral surface of the core 2, a remarkable turbulent flow effect can be expected, and the sleeve 1 and the core 2 can be expected. Since the high flow rate effect is added by the narrow gap flow path formed by the above, the heat transfer coefficient is further improved.

[Configuration example 2]
In FIG. 5, a protrusion 21, which is a spiral minute protrusion, is provided on the outer peripheral surface of the core 2 as turbulent flow generation means, and the spiral winding direction of the protrusion 21 is opposite to the flow direction of the coolant flowing in the sleeve 1. It is an expanded sectional view of the cooling roller 20 when it is set as the winding direction in which feed is generated in the direction of.

  In FIG. 1 of the configuration example 1, the flow direction of the coolant flowing in the sleeve 1 and the coolant feed direction by the spiral protrusion 21 are the same. In this case, when the core 2 together with the sleeve 1 rotates to the right, the coolant flows in the feeding direction (in FIG. 1, from the left to the right in the drawing) while spirally moving so as to generate a turbulent flow. It can be said that it is the structure which attaches importance to the fluid resistance suppression of the coolant which flows through.

  On the other hand, the protrusion 21 which is the turbulent flow generating means of the present configuration example suppresses the fluid resistance of the coolant flowing in the sleeve 1 and has a larger and stronger turbulent flow than the configuration example 1 so as to improve the heat transfer coefficient. Turbulent flow generation emphasis (consider heat transfer improvement).

  Making the turbulent flow too large or too strong is not good because the fluid resistance becomes too large, but if a large and strong turbulent flow is generated, the stirring force increases and the coolant becomes more mixed. As the method, the size of the spiral-shaped protrusion 21 provided on the outer peripheral surface of the core 2 may be small, and only the spiral winding direction is fed in the direction opposite to the coolant flow direction. What is necessary is just to make it the winding direction. For example, when the core 2 as shown in FIG. 5 rotates clockwise and the coolant flows from the left to the right in the figure, the spiral winding direction is the left-handed direction opposite to that in FIG. In this way, when the core 2 rotates to the right, in the vicinity of the outer peripheral surface of the core 2, the direction opposite to the original coolant flow from the upstream side in the coolant flow direction to the downstream direction in the sleeve 1 (upstream direction). Since the force (flow) that is going to be sent to the vehicle will collide, a larger, stronger, more complex and random turbulence will occur. Therefore, the heat transfer efficiency is remarkably improved by the turbulent flow effect by the reverse feed and the flow velocity increasing effect by the narrow flow path.

  However, depending on the size of the shape of the protrusion 21, care must be taken because the cooling liquid cannot be stirred well or the fluid resistance becomes too large. For example, if the projection 21 is very small, even if the feed direction is opposite to the flow direction of the coolant flowing in the sleeve 1, the fluid resistance is small and does not cause a problem. It is difficult to anticipate the flow effect. On the other hand, if the protrusion 21 is large, a large turbulent flow effect can be expected. However, naturally, the feeding force in the direction opposite to the flow direction of the coolant flowing in the sleeve 1 is greatly increased, so that the fluid resistance increases. End up.

  The size and shape of the protrusion 21 varies depending on each case depending on the size (diameter) of the sleeve 1, the flow rate and flow rate of the cooling medium, the specification conditions such as the cooling performance target, and so on. I can't. The present applicants have determined the optimal shape and size of the spiral of the protrusion 21 by comparison and confirmation through simulation and experimental evaluation so that the maximum turbulent effect can be obtained with the minimum fluid resistance. Further, in the case of a spiral shape, the spiral pitch interval is a factor that determines the frequency of occurrence of turbulent flow and the position interval at which it occurs, so the spiral pitch interval must be taken into consideration as well. For example, when the inner diameter φ30 [mm] of the sleeve 1 and the outer diameter φ24 [mm] of the core 2, that is, the flow path gap 3 [mm], the height of the spiral protrusion 62 from the outer peripheral surface of the core 2 is set to 0. About 8 [mm] and the helical pitch interval were about 5 [mm].

  In addition, if the spiral winding direction of the spiral groove 23 shown in FIG. 4 is also left-handed in which the feed in the direction opposite to the flow direction of the coolant is generated, the heat transfer rate is improved as compared with the right-handed FIG.

  Further, in the case of the cooling roller 20 configured by the sleeve 1 and the core 2 of this configuration example, the fluid is generated along with the generation of turbulent flow by rotating the sleeve 1 and the core 2 in synchronization in the same direction as described above. Resistance can be suppressed.

  On the other hand, the rotation speed and the rotation direction of the sleeve 1 and the core 2 may be different. As a result, the swirl speed component of the coolant is greatly different between the vicinity of the inner wall surface of the sleeve 1 and the vicinity of the outer peripheral surface of the core 2, and the heat transfer rate from the inner wall surface of the sleeve 1 to the coolant is increased by promoting turbulence. improves. As the rotation of the core 2 is different from the number of rotations of the sleeve 1, such as, for example, the number of rotations several times that of the sleeve 1 or, on the contrary, stationary and non-rotation, the effect can be obtained. If the maximum effect is desired, the core 2 may be rotated in the direction opposite to the rotation direction of the sleeve 1. Further, in this configuration example, since the turbulent flow is amplified by the spiral projection 21 which is a turbulent flow generating means provided on the outer peripheral surface of the core 2, a remarkable turbulent flow effect can be expected, and the sleeve 1 and the core 2 can be expected. Since the high flow rate effect is added by the narrow gap flow path formed by the above, the heat transfer coefficient is further improved. Moreover, the effect is further improved by making the turbulent flow generation means into a reverse feed type spiral projection 21 as shown in FIG.

[Configuration example 3]
FIG. 6 is an enlarged cross-sectional view of the cooling roller 20 when a large number of minute holes 24 are provided as turbulent flow generating means on the entire outer peripheral surface of the core 2.

  Similar to the spiral-shaped groove 23 shown in FIG. 4, the turbulent flow effect as in the case of the spiral-shaped protrusion 21 cannot be expected, but the fluid resistance can be very small, and the channel gap can be narrowed. The flow rate can be increased. If the holes are smaller, a large number of holes 24 can be formed in the entire outer peripheral surface of the core 2 without gaps. Therefore, the number of holes 24 provided on the outer peripheral surface of the core 2 is markedly larger than that of the spiral groove 23 shown in FIG. The turbulent flow can be uniformly generated over the entire outer peripheral surface of the core 2.

  Therefore, since the turbulent flow having the same magnitude and strength is generated almost uniformly over the entire area of the outer peripheral surface of the core 2 (circumferential direction and axial direction of the core 2), the coolant temperature in the channel gap is made uniform. In addition to suppressing fluid resistance, the heat flux W can be increased and its uniformity can be ensured. The shape of the hole 24 is not limited to a round hole, a long hole, a polygonal hole, and the like. You can decide.

  In addition, the formation method of the protrusion 21, the groove | channel 23, the hole 24 etc. which are the turbulent flow generation means to the outer peripheral surface of the core 2 should just be performed by die forming, such as cutting or casting and extrusion.

[Configuration Example 4]
FIG. 7 is an enlarged cross-sectional view of the cooling roller 20 when a large number of minute irregularities are provided on the entire outer peripheral surface of the core 2 as a turbulent flow generating means, and the entire outer peripheral surface of the core 2 becomes the irregular surface 65. is there.

  Similar to the spiral groove 23 shown in FIG. 4 and the hole 24 shown in FIG. 6, the turbulent flow effect as in the case of the spiral projection 21 cannot be expected, but the fluid resistance can be made extremely small, The passage gap can be narrowed and the flow velocity can be increased. Furthermore, since the concave / convex surface 65 can be finely formed in the hole 24 or more with the concave / convex surface 65, it is uniform over the entire outer peripheral surface of the core 2 (circumferential direction and axial direction of the core 2). Turbulence can be generated, that is, the coolant temperature in the channel gap can be made more uniform. Therefore, it is possible to suppress the fluid resistance, increase the heat flux W, and ensure its uniformity.

  In addition, it may be a rough surface that is a finer uneven shape, the shape is random, and the formation process does not require much labor. However, if the irregularities are made too fine, effective turbulence hardly occurs, and it becomes difficult to effectively mix the coolant. The optimum shape and size of the irregularities provided on the outer peripheral surface of the core 2 may be determined while confirming and examining the generation of turbulent flow together with fluid resistance through simulation or the like.

  When the unevenness as the turbulent flow generating means provided on the outer peripheral surface of the core 2 is minute or fine, the processing method is not only cutting, but with some variation in the shape, but with a file processing such as paper or grinder, Roughing such as sandblasting may be used. In the case of a fine uneven surface, it may be possible to use a rough substrate for roller production by casting or extrusion as it is, instead of intentionally forming the unevenness.

[Configuration Example 5]
In the configuration example 1 to the configuration example 4 described above, turbulent flow generating means (projections, grooves, holes, uneven surfaces, rough surfaces, etc.) are formed directly on the outer peripheral surface of the core 2 that is an internal member in which the sleeve 1 is included. Although the case where the core 2 and the turbulent flow generating means are integrated has been described, the turbulent flow generating means is not necessarily formed integrally with the core 2.

  Advantages when the turbulent flow generating means is integrally formed with the core 2 include reduction in the number of parts and assembly process. However, there is a possibility that problems may arise in part cost, time and weight of forming processing, and weight. In particular, regarding the weight, since it is necessary to make the outer diameter dimension of the core 2 close to the inner diameter dimension of the sleeve 1 in order to form a narrow flow path gap, the ratio of the core 2 in the sleeve 1 increases, and as a result, the core 2 Significantly affects the overall weight of the cooling roller 20.

  In addition, in order to form the turbulent flow generating means on the outer peripheral surface of the core 2, the material used for the core 2 needs to have strength and rigidity sufficient to withstand the forming process (cutting, molding, etc.). Therefore, the material used for the core 2 is inevitably iron or stainless steel, which is very heavy. Even if weight reduction is considered, it is an aluminum material and cannot be made as light as a resin material. In the case of a resin material, if the shape of the core 2 is a simple shape such as a columnar shape, the load at the time of molding or processing is not so much applied, so that the axial center accuracy can be obtained. However, if an attempt is made to form complicated shapes such as protrusions and grooves on the surface, the straightness may be distorted due to a large load during formation. In addition, it is difficult to form fine shapes with resin materials, maintaining shape and durability (protrusions are deformed or missing, grooves and holes are filled, uneven surfaces and rough surfaces become smooth surfaces. There is also a problem in avoiding it.

  Therefore, in this configuration example, in order to reduce the cost, reduce the time and effort of forming processing, increase the degree of freedom of the shape of the turbulent flow generation means, and reduce the weight of the core 2 that is the inclusion member, The flow generating means is formed on a member separate from the core 2, and the separate member is attached to the outer peripheral surface of the core 2.

  FIG. 8 shows a cylindrical separate member 26 provided with a spiral protrusion 21 on the outer peripheral surface of the cylindrical core 2a. The spiral winding direction of the protrusion 21 provided on the separate member 26 is shown in FIG. FIG. 4 is an enlarged cross-sectional view of the cooling roller 20 when the winding direction is such that feed occurs in a direction opposite to the flow direction of the coolant flowing in the sleeve 1.

  The core 2a is formed into a cylindrical shape that is not subjected to a molding load or a processing load using a resin material such as an engineering plastic having a light weight and corresponding rigidity, and the separate member 26 is formed of, for example, an elastic SUS301-CSP having a thin plate thickness. It is formed into a cylindrical shape using a stainless steel strip for leaf springs.

  In this configuration example, the protrusion 21 formed on the separate member 26 is formed to have a spiral shape like the protrusion 21 shown in FIG. 5 when the plate-like separate member 26 is curved into a cylindrical shape. . Then, the separate member 26 is wound around and fixed to the outer peripheral surface of the columnar core 2a formed of a resin material. At this time, if the separate member 26 is previously formed into a cylindrical shape (curved shape) having an inner diameter smaller than the outer diameter of the core 2a, the spring property (elasticity) force of the separate member 26 itself can be used. This makes it easy to attach to the core 2a.

  If the core 2a has a cylindrical shape, molding accuracy and straightness accuracy can be ensured even if it is not a material having high strength and rigidity, so that the core 2a can be made into a resin, and problems such as cost, labor, and weight are solved. Is done.

  However, as a selection criterion for the material of the inclusion member including the core 2 shown in FIG. 1 and the core 2a shown in FIG. 8, first, the first condition is the influence of the corrosiveness, solubility, permeability, etc. by the coolant. Therefore, weight reduction, cost, ease of forming, and the like are the next selection conditions. Therefore, in order to suppress the influence, the stainless steel material, the aluminum material, or the like may be used as an inclusion member such as the core 2 or the core 2a.

  As for the turbulent flow generating means, if the turbulent flow generating means is formed on a separate member 26 such as a thin sheet metal, various molding methods and processing such as press processing, laser processing, etching processing and the like that can be mass-produced at low cost. A fine shape and a desired shape of the turbulent flow generation means that could not be realized with the core 2 processed by integral molding as shown in FIG. 5 and the like can be freely formed.

  The material of the separate member 26 may be a stainless steel material, but first, considering compatibility with the coolant, iron, aluminum, copper, which may be easily processed at low cost, and in some cases, a resin system may be used.

  However, considering the ease of mounting on the core 2 that is the inclusion member, a material having elasticity is recommended as the material of the separate member 26. The form of the separate member 26 is not limited to a plate shape, but may be a linear shape (coil shape), a net shape, a fiber shape, a tubular shape, or a curved shape. 9 is a thin plate-shaped round hole type, FIG. 10 is a thin plate-shaped long hole type, FIG. 11 is a thin wire net-shaped rectangular type, and FIG. 12 is a thin wire net-shaped rhombus type.

  In consideration of assembling property, component replacement property, component recyclability and reusability, the separate member 26 is preferably configured to be detachable from the core 2a which is an inclusion member.

[Configuration Example 6]
In this configuration example, as shown in FIG. 13, the cooling roller 20 includes a sleeve 1 that is an outer tube, and a spiral-shaped minute protrusion 31 that generates a feed in a direction opposite to the flow of the cooling liquid as a turbulent flow generating means. The tube structure is formed of an inner tube 3 which is an inner member provided on the outer peripheral surface and included in the sleeve 1. Then, as shown in FIG. 13, the cooling liquid flows through the narrow gap formed by the sleeve 1 and the inner pipe 3 and the hollow inside of the inner pipe 3 as flow paths. The coolant flows so as to reciprocate in the cooling roller 20.

  In the present configuration example, the sleeve 1 and the inner tube 3 are both rotated to the right when viewed from the right side in the axial direction of the cooling roller 20 shown in FIG. 13, and the gap formed by the sleeve 1 and the inner tube 3 is used as the forward flow path. The cooling liquid flows in from the left side in the figure and flows toward the right side in the figure, and makes a U-turn at the right end of the sleeve 1 in the figure to flow the cooling liquid into the hollow interior of the inner pipe 3, and returns to the hollow inside of the inner pipe 3. It flows out as a road toward the left side in the figure. When the cooling liquid is flowed in this way, the flow velocity of the cooling liquid in the vicinity of the inner wall surface of the sleeve 1 increases due to the narrowing of the flow gap of the forward flow path, and the outer periphery of the inner tube 3 by the spiral protrusion 31 is further increased. Since the turbulent flow effect in the vicinity of the surface is added, the heat transfer rate from the inner wall surface of the sleeve 1 to the coolant is improved by a synergistic effect.

  If the outer diameter of the inner tube 3 is made closer to the inner diameter of the sleeve 1 and the gap is made narrower, the flow rate of the coolant near the inner wall surface of the sleeve 1 can be as high as that of the core 2 shown in FIG. As a result, the heat transfer rate from the inner wall surface of the sleeve 1 to the cooling liquid is further improved, and as a result, the cooling effect of the paper P by the cooling roller 20 is improved.

  Needless to say, in the present configuration example, the turbulent flow generating means is the reverse feed type spiral projection 31, so that the turbulent flow generation means is more than the forward feed type spiral projection 21 as shown in FIG. 1. Although the cooling performance is improved, care must be taken because the fluid resistance increases.

  Here, when the turbulent flow generating means provided on the outer peripheral surface of the inner tube 3 has a spiral shape, it is necessary to select a forward-feed type or a reverse-feed type depending on the specifications of the apparatus and to use them properly. That is, it is necessary to select which of the forward feed type turbulent flow generation means and the reverse feed type turbulent flow generation means is used in view of desired cooling performance, pump power, and the like. The turbulent flow generating means provided on the outer peripheral surface of the inner tube 3 is not limited to the spiral projection 31 as shown in FIG. 13, but can be applied to a groove, a hole, an uneven surface, or a rough surface. You can use them properly.

  The rotary pipe joint is attached to the end of the cooling roller 20 in the axial direction and has a mechanical seal in order to allow the cooling liquid to flow into or out of the cooling roller 20. Connect to a tube or pipe connected to a pump, etc. via a rotary joint.

  In the case of a roller configuration in which the cooling liquid flows in one direction from one end side to the other end side of the cooling roller 20 as shown in FIG. 3, the inflow joint is connected to one end side of the cooling roller 20 and the outflow joint is provided. It is necessary to provide joints at the other end of the cooling roller 20, that is, at both ends of the cooling roller 20. On the other hand, in the case of the cooling roller 20 having a reciprocating flow path as shown in FIG. 13 of this configuration example, a double joint having both functions of inflow and outflow is provided only at one end of the cooling roller 20. Therefore, an empty space is created on the other end side of the cooling roller 20. This empty space contributes to downsizing of an apparatus such as an image forming apparatus, and the workability is improved because the cooling liquid tube and piping are not obstructed when the cooling roller 20 is assembled to the apparatus.

  The path of the reciprocating flow path of the cooling liquid in the cooling roller 20 may be in the direction opposite to the direction shown in FIG. That is, contrary to the flow direction of FIG. 13, the cooling liquid flows in using the hollow interior of the inner pipe 3 as the forward flow path, and the cooling liquid flows out using the gap formed by the sleeve 1 and the inner pipe 3 as the return flow path. May be. However, since the flow direction of the coolant flowing through the gap is opposite to the direction shown in FIG. 13 (from right to left in FIG. 13), if the turbulent flow generating means is a spiral projection, the spiral winding Care must be taken in the direction.

  Further, in the case of the cooling roller 20 configured by the sleeve 1 and the inner tube 3 of the present configuration example, the turbulent flow is generated by rotating the sleeve 1 and the inner tube 3 in synchronization in the same direction as described above. At the same time, fluid resistance can be suppressed.

  On the other hand, the rotation speed and the rotation direction of the sleeve 1 and the inner tube 3 may be different. As a result, the swirl speed component of the coolant is greatly different between the vicinity of the inner wall surface of the sleeve 1 and the vicinity of the outer peripheral surface of the inner tube 3, and the heat transfer coefficient from the inner wall surface of the sleeve 1 to the coolant is promoted by generating turbulent flow. More improved. As the rotation of the inner tube 3 is different from the number of rotations of the sleeve 1, such as, for example, the number of rotations of the sleeve 1 is many times higher than that of the sleeve 1 or is stationary and non-rotation, the effect can be obtained. . If the maximum effect is desired, the inner tube 3 may be rotated in the direction opposite to the rotation direction of the sleeve 1. Furthermore, in this configuration example, since the turbulent flow is amplified by the spiral projection 31 which is a turbulent flow generating means provided on the outer peripheral surface of the inner tube 3, a remarkable turbulent flow effect can be expected. Moreover, the effect is further improved by making the turbulent flow generation means into a reverse feed type spiral projection 31 as shown in FIG.

[Configuration Example 7]
In this configuration example, as shown in FIG. 14, the cooling roller 20 includes a sleeve 1 that is an outer tube, and a coolant flow that is included in the sleeve 1 and that is described with reference to FIG. 5 as turbulent flow generation means. The tube structure is composed of a hollow cylinder 4 having a spiral-shaped projection 41 on the outer peripheral surface that generates feed in the opposite direction and an inner tube 3 inserted into the hollow inside of the cylinder 4. Then, as shown in FIG. 14, the cooling liquid flows through the gap formed by the sleeve 1 and the cylinder 4 and the hollow interior of the inner tube 3 as flow paths, and the gap and the hollow interior of the inner tube 3 are connected to each other. The coolant flows so that the coolant reciprocates in the cooling roller 20. In this configuration example, as shown in FIG. 14, the inner tube 3 is provided inside the cylinder 4, but the inner tube 3 is not provided inside the cylinder 4, and a through hole is provided instead of the inner tube 3. 4 may be formed, or the inner tube 3 and the through hole may be combined.

  The inner tube 3 is inserted and fixed in the cylinder 4. For example, when the large-diameter cylinder 4 is formed of a resin material and the small-diameter inner tube 3 is manufactured of a metal material such as aluminum, the weight can be reduced. . Further, if a turbulent flow generating means separate from the cylinder 4 is provided on the outer peripheral surface of the cylinder 4 as in the core 2a shown in FIG. 8, the advantages and effects described in the configuration example 5 can be obtained.

  In this configuration example, the sleeve 1, the inner tube 3, and the cylinder 4 all rotate clockwise as viewed from the right side in the axial direction of the cooling roller 20 shown in FIG. 14, and the gap formed between the sleeve 1 and the cylinder 4 passes through the forward flow path. As shown in FIG. 14, the coolant flows in from the left side in FIG. 14 and makes a U-turn at the right end of the sleeve 1 so that the coolant flows out toward the left side in FIG. When the coolant is flowed in this way, the flow velocity in the vicinity of the inner wall surface of the sleeve 1 increases as the flow passage gap of the forward flow passage becomes narrower than that in FIG. As a result, a heat transfer rate from the inner wall surface of the sleeve 1 to the cooling liquid is improved by a synergistic effect, and a further temperature reduction of the paper P can be expected.

  Needless to say, in the present configuration example, the turbulent flow generating means provided on the outer peripheral surface of the cylinder 4 is the reverse feed type spiral protrusion 41, so that the turbulent flow generating means is made to be a forward feed type helical protrusion. Although the cooling performance is improved, care must be taken because the fluid resistance increases as compared with the forward-feed type turbulent flow generating means. The turbulent flow generating means provided on the outer peripheral surface of the cylinder 4 is not limited to a spiral projection, but can be applied to a groove, a hole, an uneven surface, a roughened surface, or the like.

  Further, in the cooling roller 20 of this configuration example, similarly to the cooling roller 20 including the inner tube 3 in the sleeve 1 described in the configuration example 6, the path of the cooling liquid in the cooling roller 20 forms a reciprocating flow path. Therefore, a joint such as a rotary joint may be provided only on one end of the cooling roller 20. This creates an empty space on the other end side of the cooling roller 20 and contributes to the downsizing of the apparatus such as the image forming apparatus. Also, when the cooling roller 20 is assembled to the apparatus, the cooling liquid tube and piping are obstructive. Thus, workability is improved.

  That is, the cooling roller 20 of this configuration example can be said to be a configuration substantially equivalent to a combination of the configuration including the core 2 of the configuration example 5 and the configuration including the inner tube 3 of the configuration example 6 within the sleeve 1. It has the advantages and effects of both.

  The inflow / outflow path of the coolant may be in the direction opposite to the direction shown in FIG. That is, contrary to the flow direction of FIG. 14, the cooling liquid is allowed to flow using the hollow interior of the inner tube 3 as the forward flow path, and the cooling liquid is flowed out using the gap formed between the sleeve 1 and the cylinder 4 as the return flow path. Also good. However, since the flow direction of the coolant flowing through the gap is opposite to the direction shown in FIG. 14 (from right to left in FIG. 14), when the turbulent flow generating means is a spiral projection, the spiral winding Care must be taken in the direction.

  Further, in the case of the cooling roller 20 constituted by the sleeve 1, the inner tube 3 and the cylinder 4 of this configuration example, the turbulent flow is obtained by rotating the sleeve 1 and the cylinder 4 in synchronization in the same direction as described above. As a result, fluid resistance can be suppressed.

  On the other hand, the rotation speed and the rotation direction of the sleeve 1 and the cylinder 4 may be different. Thereby, the swirl speed component of the coolant is greatly different between the vicinity of the inner wall surface of the sleeve 1 and the vicinity of the outer peripheral surface of the cylinder 4, and the difference promotes the generation of turbulent flow and further improves the heat transfer coefficient. As the rotation of the cylinder 4 is different from the number of rotations of the sleeve 1, such as, for example, the number of rotations of the sleeve 1 is many times higher than that of the sleeve 1 or is stationary and non-rotation, the effect can be obtained. If the maximum effect is desired, the cylinder 4 may be rotated in the direction opposite to the rotation direction of the sleeve 1. Further, in this configuration example, since the turbulent flow is amplified by the spiral projection 41 which is a turbulent flow generating means provided on the outer peripheral surface of the cylinder 4, a remarkable turbulent flow effect can be expected, and the sleeve 1 and the cylinder 4 can be expected. Since the high flow rate effect is added by the narrow gap flow path formed by the above, the heat transfer coefficient is further improved. Moreover, as shown in FIG. 14, the effect is further improved by making the turbulent flow generating means provided on the outer peripheral surface of the cylinder 4 into a reverse feed type spiral projection 41.

[Configuration Example 8]
In this configuration example, as shown in FIG. 15, the inner tube 3 is enclosed in the sleeve 1 which is the outer tube of the cooling roller 20, and a hollow cylinder 4 is inserted outside the inner tube 3. ing. The cooling liquid flows through the gap formed by the sleeve 1 and the cylinder 4 and the hollow inside of the inner tube 3 as flow paths, and the cooling liquid flows through the gap and the hollow inside of the inner tube 3 to cool the cooling liquid. The coolant reciprocates in the roller 20.

  Further, a spiral-shaped protrusion 41 that generates a feed in the direction opposite to the flow of the coolant as shown in FIG. 15 is provided on the outer peripheral surface of the cylinder 4. Further, in this configuration example, as shown in FIG. 15, the outer peripheral surface of the cylinder 4 having substantially the same width as the width of the sheet P to be cooled by contacting the sleeve 1 of the cooling roller 20 (width in the cooling roller axial direction). A spiral projection 41 is provided in the region. In other words, the spiral protrusion 41 is not provided on the outer peripheral surface of the cylinder 4 outside the area of the paper P.

  As in the present configuration example, the spiral projection 41 is provided only in a region having substantially the same width as the region of the sleeve 1 with which the paper P is in contact, so that the flow of the portion where the spiral projection 41 on the outer peripheral surface of the cylinder 4 is not provided. In the path, no fluid resistance is generated by the protrusion 41 with respect to the coolant flowing in the sleeve 1, and the coolant in the flow path region flows smoothly. Thereby, the fluid resistance in an unnecessary area is suppressed, the load of the pump for sending the coolant into the cooling roller 20 is small, the power consumption is reduced, and the durability is improved. In addition, a pump with a liquid feeding performance that is one rank lower than the case where the spiral protrusion 41 is provided over the entire outer peripheral surface of the cylinder 4 can be achieved, and the cost can be reduced. In addition, by providing turbulent flow generation means only in the necessary area, waste is eliminated (cost reduction due to reduction of the formation area of the spiral protrusion, prevention of turbulent flow generation in areas where cooling is not required, etc.) ), The heat transfer coefficient can be improved efficiently and effectively.

[Configuration Example 9]
Next, FIG. 16 shows a schematic configuration diagram of a tandem type intermediate transfer belt type color image forming apparatus on which the cooling device 18 having any one of the cooling rollers 20 of the present invention shown in the configuration examples 1 to 8 is mounted. .

  The cooling device 18 having the cooling roller 20 of the present invention shown in the configuration example 1 to the configuration example 8 is not limited to that provided in the image forming apparatus, and may be an apparatus that needs to cool the sheet-like member. Can be adapted. In this configuration example, a liquid is used as a cooling medium. However, a gas may be used as long as it is a fluid medium.

  An intermediate transfer belt 51 as an intermediate transfer medium is stretched by a plurality of rollers, and the intermediate transfer belt 51 is configured to rotate by these rollers, and an image forming process means is disposed around the intermediate transfer belt 51. ing.

  When the rotation direction of the intermediate transfer belt 51 is indicated by an arrow a in the drawing, image formation is performed in order from the upstream side in the rotation direction of the intermediate transfer belt 51 above the intermediate transfer belt 51 and between the rollers 52 and 53. As the process means, an image station 54Y, an image station 54C, an image station 54M, and an image station 54Bk are arranged. For example, in the image station 54Y, a charging unit 10Y, an optical writing unit 12Y, a developing unit 13Y, and a cleaning unit 14Y are arranged around the drum-shaped photoconductor 11Y, and further, at an opposite position of the photoconductor 11Y with the intermediate transfer belt 51 interposed therebetween. A primary transfer roller 15 </ b> Y is provided as a transfer unit to the intermediate transfer belt 51. The other three image stations 54C, 54M and 54Bk have the same configuration. The four image stations 54Y, 54C, 54M, and 54Bk are arranged in parallel on the left and right sides so as to have a predetermined pitch interval.

  In this embodiment, the optical writing unit 12 is an optical system using an LED as a light source, but it can also be configured by a laser optical system using a semiconductor laser as a light source, and the photosensitive member 11 is exposed according to image information. .

  Below the intermediate transfer belt 51, a sheet storage unit 19 and a sheet feeding roller 223, a registration roller pair 221, and a roller 55 that stretches the intermediate transfer belt 51 are interposed via the intermediate transfer belt 51. The surface of the intermediate transfer belt 51 is opposed to a secondary transfer roller 56 that is provided so as to face the secondary transfer roller 56 as a toner image transfer unit from the intermediate transfer belt 51 to the paper P and a roller 58 that contacts the back surface of the intermediate transfer belt 51. Cleaning means 59 provided so as to be in contact with the surface and cleaning the front surface of the intermediate transfer belt 51, the heat fixing device 16, the cooling device 18 having the cooling roller 20 for cooling the paper P, and the discharge of the paper P after toner fixing. A paper discharge accommodating portion 17 and the like are arranged. A paper transport path 28 extending from the paper storage unit 19 to the paper discharge storage unit 17 extends. In addition, when forming an image on the back side of the paper P during double-sided image formation, the front and back of the paper P that has once passed through the cooling device 18 are reversed and transported to the registration roller pair 221 again. A path 29 is also provided.

  The cooling roller 20 of the cooling device 18 is a heat receiving portion that receives the heat of the paper P, and is connected / connected by the pipe 105 together with the radiator 103, the pump 100, and the tank 101, to which the cooling fan 104 is mounted, and the cooling liquid is enclosed. ing. As shown by the arrow of the pipe 105, the cooling liquid circulation path supplies the cooling liquid cooled by the radiator 103 to the cooling roller 20, discharges it after passing through the cooling roller 20, and thereafter, tank 101, pump The cooling liquid is circulated by the rotational pressure of the pump 100 and radiated by the radiator 103 to cool the cooling liquid, that is, the cooling roller 20. The liquid feeding capacity of the pump 100, the size of the radiator 103, and the like are selected based on the flow rate, pressure, cooling efficiency, and the like determined by the thermal design conditions (the amount of heat and temperature conditions that the cooling roller 20 should cool).

  When the image forming process is focused on the image station 54Y, the image forming process conforms to a general electrostatic recording method, and the light writing unit 12Y exposes the photosensitive member 11Y uniformly charged by the charging unit 10Y in the dark. Then, an electrostatic latent image is formed, and the electrostatic latent image is visualized as a toner image by the developing device 13Y. The toner image is transferred from the photoreceptor 11Y to the intermediate transfer belt 51 by the primary transfer roller 15Y. The surface of the photoreceptor 11Y after the transfer is cleaned by the cleaning unit 14Y. The other image stations 54 have the same configuration as the image station 54Y, and the same image forming process is performed.

  The developing devices 13Y, 13C, 13M, and 13Bk in the image stations 54Y, 54C, 54M, and 54Bk have a visible image forming function using toners of four different colors, and the image stations 54Y, 54C, 54M, and 54Bk. If yellow, cyan, magenta and black are shared, a full-color image can be formed. Therefore, while the same image forming area of the intermediate transfer belt 51 sequentially passes through the four image stations 54Y, 54C, 54M, and 54Bk, the primary provided so as to face the respective photoreceptors 11 with the intermediate transfer belt 51 interposed therebetween. If the toner images are transferred one by one on the intermediate transfer belt 51 by the transfer bias applied by the transfer roller 15, the same image forming area is assigned to each of the image stations 54Y, 54C, 54M and 54Bk. At the time of passing, the full color toner image can be obtained by overlapping transfer on the same image area.

  Then, the full color toner image formed on the intermediate transfer belt 51 is transferred to the paper P. The intermediate transfer belt 51 after the transfer is cleaned by a cleaning unit 59. For transfer onto the paper P, a transfer bias is applied to the secondary transfer roller 56 at the time of transfer, and a transfer electric field is formed between the secondary transfer roller 56 and the roller 55 via the intermediate transfer belt 51 to perform secondary transfer. This is done by passing the paper P through the nip portion between the roller 56 and the intermediate transfer belt 51. After the transfer of the full-color toner image from the intermediate transfer belt 51 to the paper P, the full-color toner image carried on the paper P is fixed on the paper P by the heat fixing device 16, so that a full-color final image is formed on the paper P. After that, the paper P is stacked in the paper discharge storage unit 17.

  In the image forming apparatus of the present embodiment, the paper P passes through the cooling device 18 disposed immediately after the heat fixing device 16 before the paper P is stacked in the paper discharge accommodating portion 17. When passing, the paper P heated by the heat fixing device 16 passes while contacting the cooling roller 20 which is a heat receiving portion, so the surface of the cooling roller 20 absorbs heat from the paper P, and this heat is absorbed. This is transmitted to the cooling liquid inside the cooling roller 20. The coolant that has been heated to a high temperature is then discharged from the cooling roller 20 and is sent to the radiator 103 with the cooling fan 104 through the tank 101 and the pump 100, where the heat is discharged outside the image forming apparatus. Be heated. The coolant whose heat has been removed by the radiator 103 and lowered to near room temperature is then sent to the cooling roller 20 again. By such an exhaust heat cycle with high cooling performance by the cooling liquid, the paper P heated to a high temperature by the heat fixing device 16 is efficiently cooled.

  Further, as described in the configuration example 1 to the configuration example 8, the cooling roller 20 of the present embodiment uses the inner member such as the core 2, the inner tube 3, and the cylinder 4 and the vicinity of the inner wall surface of the sleeve 1 that is an outer tube. Since the flow path of the coolant flowing through the nozzle is narrowed and the inclusion member is provided with a turbulent flow generating means such as a spiral projection, the cooling performance can be further improved for the reasons described above.

  Therefore, in the image forming apparatus according to the present embodiment, the toner on the paper P can be surely cured when the paper P is stacked on the paper discharge storage unit 17. In particular, it is possible to avoid the blocking phenomenon that has been a major problem in the double-sided image formation output in which the fixing operation is performed twice on the paper P by the thermal fixing device 16.

As described above, according to the present embodiment, the cooling roller 20 including the sleeve 1 that is a hollow tubular member, and the pump 100 that is a cooling medium conveying unit that conveys the cooling liquid that is the cooling medium into the sleeve 1 are provided. The cooling device 18 that cools the paper P by bringing the paper P, which is a sheet-like member, into contact with the cooling roller 20, has an inner member such as a core 2 included in the sleeve 1, and includes the inner wall surface and the inner wall of the sleeve 1. A flow path through which the coolant flows is formed between the outer peripheral surface of the member, and turbulent flow generating means such as a spiral projection 21 for generating turbulent flow in the coolant is provided on the outer peripheral surface of the inner member. In the present embodiment, the flow of the coolant flowing through the flow path is turbulent by the turbulent flow generating means provided on the outer peripheral surface of the inner member such as the core 2. Thereby, replacement of the coolant having a high temperature in the vicinity of the inner wall surface of the sleeve 1 and the coolant having a low temperature at a position away from the inner wall surface is actively performed. Therefore, since the temperature of the coolant near the inner wall surface can be lowered as compared with the case where the turbulent flow generating means is not provided on the outer peripheral surface of the inner member, the sleeve 1 can be effectively cooled by the coolant. it can. Therefore, the cooling efficiency of the paper P by the cooling roller 20 made of the sleeve 1 can be improved.
Further, by providing the spiral protrusion 41 in an area substantially the same width as the sheet P to be cooled by contact with the sleeve 1, the flow path of the portion of the outer peripheral surface of the cylinder 4 where the spiral protrusion 41 is not provided. Then, the fluid resistance due to the protrusion 41 does not occur with respect to the coolant flowing in the sleeve 1, and the coolant in the flow path region flows smoothly. Thereby, the fluid resistance in an unnecessary area | region is suppressed, the load of the pump 100 which sends a cooling fluid in the cooling roller 20 is small, power consumption can be reduced, and durability can also be improved. In addition, a pump with a liquid feeding performance that is one rank lower than the case where the spiral protrusion 41 is provided over the entire outer peripheral surface of the cylinder 4 can be achieved, and the cost can be reduced. In addition, by providing turbulent flow generation means only in the necessary area, waste is eliminated (cost reduction due to reduction of the formation area of the spiral protrusion, prevention of turbulent flow generation in areas where cooling is not required, etc.) ), The heat transfer coefficient can be improved efficiently and effectively.
Further, according to the present embodiment, the turbulent flow generating means is the spiral protrusion 21 or groove 23 provided on the outer peripheral surface of the inner member such as the core 2, so that the spiral protrusion 21 or groove 23 is provided. As a result, turbulent flow is generated in the flow near the outer peripheral wall of the inner member, and the heat transfer rate from the inner wall surface of the sleeve 1 to the coolant flowing through the flow path can be improved by the turbulent flow effect .
Also, according to this embodiment, the turbulence generating means, that is like a hole 24 provided on the outer peripheral surface of the enclosing member, such as a core 2, substantially equally as great over the entire outer peripheral surface of the enclosing member Since the turbulent flow can be generated, the temperature of the coolant in the gap between the channels can be made uniform, the fluid resistance can be suppressed, the heat flux W can be increased, and the uniformity thereof can be ensured.
Further, according to the present embodiment, the turbulent flow generating means is the uneven surface 25 or the roughened surface provided on the outer peripheral surface of the inner member such as the core 2, so that the outer periphery of the inner member as the turbulent flow generating means. It can be formed finer than the case where the holes 24 are provided on the surface. Therefore, it is possible to generate turbulent flow of substantially the same size over the entire area of the outer peripheral surface of the inclusion member as compared with the case where the hole 24 is provided in the outer peripheral surface of the inclusion member as the turbulent flow generation means. The coolant temperature can be made more uniform, the fluid resistance can be suppressed, the heat flux W can be increased, and the uniformity can be ensured.
Further, according to the present embodiment, the inner member is the core 2 which is a core member, and is formed by the outer peripheral surface of the core 2 provided with the spiral-shaped protrusion 21 which is a turbulent flow generating means and the inner wall surface of the sleeve 1. There is a flow path through which the coolant flows in the gap. As a result, the sleeve 1 has a high flow velocity effect due to the narrow gap flow path formed by the sleeve 1 and the core 2 and a turbulent flow effect due to the turbulence generating means, as compared with the case where the core 2 is not included in the sleeve 1. The heat transfer rate from the inner wall to the cooling liquid is further improved, and the cooling performance of the paper P by the cooling roller 20 can be remarkably improved.
Further, according to this embodiment, the enclosed member is an inner tube 3 of the tubular structure than sleeves 1, the outer channel flowing between the sleeve 1 and the inner tube 3 a cooling liquid, and the inner tube 3 A double pipe structure having an inner flow path through which the cooling liquid flows is formed by the sleeve 1 and the inner pipe 3 . As a result, the inner tube 3 is inserted into the sleeve 1 by the high flow velocity effect caused by the narrow gap flow path formed by the sleeve 1 and the inner tube 3 and the turbulent flow effect caused by the spiral projection 31 that is a turbulent flow generating means. Compared with the case where the sleeve is not encapsulated, the heat transfer rate from the inner wall of the sleeve 1 to the coolant is further improved, and the cooling performance of the paper P by the cooling roller 20 can be remarkably improved. Furthermore, since it is only necessary to provide a joint such as a double rotary joint at only one end of the cooling roller 20, an empty space is created on the other end side of the cooling roller 20, thereby reducing the size of an apparatus such as an image forming apparatus. In addition, when the cooling roller 20 is assembled to the cooling device 18, the tube and piping of the cooling liquid do not get in the way and workability is improved.
Further, according to the present embodiment, the inner member is a cylinder 4 having a hollow through which a coolant can pass, and an outer peripheral surface of the cylinder 4 provided with a spiral projection 41 as a turbulent flow generating means and a sleeve. 1 has a flow path through which the coolant flows in a gap formed by the inner wall surface. As a result, the sleeve 1 and the cylinder 4 have a high flow velocity effect due to a narrow gap flow path and a turbulent flow effect due to the projection 41, compared with the case where the cylinder 4 is not included in the sleeve 1. The heat transfer rate from the wall surface to the coolant is further improved, and the cooling performance of the paper P by the cooling roller 20 can be significantly improved. Further, by attaching a cylinder 4 having a larger outer diameter than the inner tube 3 inside the hollow of the sleeve 1 so as to enclose the inner tube 3, a joint such as a double rotary joint is attached only to one end of the cooling roller 20. Therefore, an empty space is created on the other end side of the cooling roller 20, which contributes to downsizing of the apparatus such as the image forming apparatus, and when the cooling roller 20 is assembled to the cooling apparatus 18, The tube and piping do not get in the way and workability is improved.
Further, according to the present embodiment, the turbulent flow generating means is formed on the separate member 26 or the like separate from the core 2 or the like that is the inclusion member, and the separate member 26 or the like is disposed on the outer peripheral surface of the core 2 or the like. As a result, it is possible to reduce the cost, reduce the time and effort of forming, increase the degree of freedom of the shape of the turbulent flow generation means, and reduce the weight of the inner member such as the core 2 and the cooling roller 20 as well. Become .
Also, according to this embodiment, the sheet and the toner image forming means such as an image station 54 for forming a toner image on the sheet P is a sheet-like member, by at least heat the toner image formed on the sheet P P In the image forming apparatus including the heat fixing device 16 that is a heat fixing means for fixing the toner image on the paper P and the cooling means for cooling the paper P on which the toner image is fixed by the heat fixing device 16, the cooling of the present invention is used as the cooling means. By using the cooling device 18 having the roller 20, the cooling efficiency of the paper P after the heat fixing by the heat fixing device 16 can be improved.

DESCRIPTION OF SYMBOLS 1 Sleeve 2 Core 3 Inner pipe | tube 4 Cylinder 10 Charging means 11 Photoconductor 12 Optical writing means 13 Developing device 14 Cleaning means 15 Primary transfer roller 16 Thermal fixing device 17 Paper discharge accommodating portion 18 Cooling device 19 Paper accommodating portion 20 Cooling roller 21 Protrusion 22 Protrusion 23 Groove 24 Hole 25 Concavity and convexity 26 Separate member 28 Paper conveyance path 29 Paper conveyance path 31 Protrusion 41 Protrusion 51 Intermediate transfer belt 52 Roller 53 Roller 54 Image station 55 Roller 56 Secondary transfer roller 58 Roller 59 Cleaning means 60 Protrusion 62 Projection 65 Uneven surface 100 Pump 101 Tank 103 Radiator 104 Cooling fan 105 Piping 116 Flow path 118 Supply port 119 Discharge port 120 Rotary joint 121 Rotary joint 123 Bearing 140 Roller 1 1 roller 142 conveyor belt 143 on the guide 144 bracket 221 pair of registration rollers 223 feed roller 500 coolant circulation device

JP 2006-003819 A

Claims (9)

A cooling roller made of a hollow tubular member;
Cooling medium conveying means for conveying the cooling medium into the tubular member,
In the cooling device that cools the sheet-like member by bringing the sheet-like member into contact with the cooling roller,
A flow path through which a cooling medium flows is formed between an inner wall surface of the tubular member and an outer peripheral surface of the inner member;
The turbulence generating means for generating turbulence in the cooling medium, wherein the tubular member of the outer peripheral surface of the encapsulating member is provided in the region of the sheet-like member substantially the same width of cooling by contact cooling device . A cooling device according to claim 1,
The cooling device according to claim 1, wherein the turbulent flow generating means is a spiral protrusion or groove provided on an outer peripheral surface of the inner member. A cooling device according to claim 1,
The cooling device according to claim 1, wherein the turbulent flow generating means is a hole provided in an outer peripheral surface of the inner member. A cooling device according to claim 1,
The cooling device according to claim 1, wherein the turbulent flow generating means is an uneven surface or a rough surface provided on an outer peripheral surface of the inner member. Claims 1, 3 or is a cooling device according 4,
The inner member is a core member, and has a flow path through which a cooling medium flows in a gap formed by an outer peripheral surface of the core member provided with the turbulent flow generation means and an inner wall surface of the tubular member. Cooling system. Claims 1, 3 or is a cooling device according 4,
The enclosed member is an inner tube of the tubular structure than the upper Symbol tubular member,
Formed between said tubular member outer channel the flowing cooling medium between the inner tube and double-tube structure having an inner passage through said inner tube cooling medium is, between the tubular member and the inner tube cooling device, characterized in that it is. Claims 1, 3 or is a cooling device according 4,
The inner member is a hollow cylinder through which a cooling medium can pass, and the cooling medium flows in a gap formed by the outer peripheral surface of the cylinder provided with the turbulent flow generating means and the inner wall surface of the tubular member. A cooling device having a flow path. Claim 1, 2, 3, 4, a cooling device 7 described was 6 or,
The said turbulent flow generation means is formed in the separate member separate from the said inclusion member, The cooling device characterized by attaching the said separate member to the outer peripheral surface of the said inclusion member. Toner image forming means for forming a toner image on a sheet-like member;
Thermal fixing means for fixing the toner image formed on the sheet-like member to the sheet-like member by at least heat;
An image forming apparatus comprising: a cooling unit that cools the sheet-like member on which the toner image is fixed by the heat fixing unit;
Wherein as the cooling means, according to claim 1,2,3,4,5,6, an image forming apparatus which comprises using a cooling device 7 or 8, wherein.

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