JP6270134B2 - Cooling device and image forming apparatus - Google Patents

Description

  The present invention relates to a cooling device including a heat receiving portion that directly or indirectly receives heat to be cooled, and a heat radiating portion that radiates heat of a refrigerant circulating between the heat receiving portion and the cooling device. The present invention relates to an image forming apparatus provided.

2. Description of the Related Art Conventionally, there is known an electronic apparatus including a cooling device for cooling a heat generation place or a processed object.
An electrophotographic image forming apparatus has a plurality of heat generation points in the apparatus. For this reason, depending on conditions such as the target device size, image forming speed, device manufacturing cost, etc., an air cooling type or liquid cooling type cooling device can be arbitrarily selected with a plurality of heat generation points in the device as cooling targets. Or those provided at a plurality of arbitrary locations are known.
As an object to be cooled in the image forming apparatus, for example, a stirring / conveying portion of a developing device in which frictional heat is generated by stirring of toner or developer when a charge is applied to the toner, or a toner image transferred to the surface is fixed. And a sheet (paper) as a recording medium after that.

  For example, Patent Document 1 describes an image forming apparatus including a liquid cooling type cooling device that cools a sheet (sheet-like member) after fixing. A belt conveyance mechanism including a pair of endless belts that sandwich and convey the sheet is provided, and a substantially flat cooling member serving as a heat receiving portion is brought into contact with an inner peripheral surface (back surface) of a portion that contacts the sheet of each endless belt, The sheet heat is indirectly received through the endless belt. The cooling member is provided with an internal flow path through which a coolant, which is a refrigerant, passes, and a circulation path is formed through which the coolant circulates with a heat exchanger (radiator) provided in the heat radiating section. In addition, the heat radiating section forcibly generates a flow of air that hits the heat exchanger (hereinafter referred to as airflow) to improve the heat exchange efficiency between the coolant and the airflow that passes through the heat exchanger, thereby exchanging heat. A blower means (fan) is provided to increase the heat dissipation capability of the vessel.

However, in the image forming apparatus disclosed in Patent Document 1, the air flow velocity hitting the heat exchanger decreases due to a failure of the blowing means or the heat exchanger clogging, or the area of the heat exchanger where the heat exchange efficiency decreases due to clogging increases. There is a risk that the heat dissipating part whose heat exchange efficiency has been reduced may continue to operate in an abnormal state.
Thus, when the heat radiating portion is in an abnormal state, a desired cooling capacity cannot be obtained when the sheet is cooled by the cooling device. Then, the toner is softened by the heat accumulated in the sheets that are insufficiently cooled and stacked on the stacking tray through the cooling device, and the sheets are stuck between the sheets by the pressure generated by the weight of the overlapped sheets. There is a problem that so-called blocking occurs.

Further, unlike the image forming apparatus of Patent Document 1, even in an image forming apparatus provided with a liquid cooling type cooling device that cools other heat generation points in the apparatus, the heat radiating portion is in an abnormal state, that is, the cooling capacity of the cooling device. Various problems arise if the operation is continued in a state in which the temperature is lowered.
For example, in an image forming apparatus provided with a cooling device for cooling the developing device, the developer temperature in the developing device rises and the softened toner aggregates to generate an abnormal image, or any configuration in the developing device. There is a problem that the developing device breaks down due to being fixed to the member.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide a cooling device that can suppress the occurrence of problems due to an abnormality in the heat dissipating part that radiates the heat of the refrigerant circulating between the heat receiving part and the heat receiving part. Is to provide.

In order to achieve the above object, the invention according to claim 1 is directed to a heat receiving part that directly or indirectly receives heat to be cooled and a heat release that dissipates the heat of the refrigerant circulating between the heat receiving part. The air temperature detection means for detecting the temperature before the heat exchange of the air heat exchanged with the refrigerant in the heat radiating portion, and the refrigerant temperature flowing into the heat radiating portion from the heat receiving portion comprising an inlet temperature detecting means for detecting, and an outlet temperature detection means for detecting the refrigerant temperature flowing in the heat receiving section from the heat radiating portion, and the abnormality determination means for determining presence of an abnormality before Symbol radiating unit, the, said The abnormality determining means is provided in the heat radiating section in a state in which the temperature range detected by the air temperature detecting means is divided and the heat radiating section is operating normally for each of the plurality of temperature sections. Temperature of the medium flowing into the heat exchanger and the heat exchanger Information on the time-dependent change of the threshold value of the medium temperature flowing out from the temperature, the time-dependent change information on the threshold value of the temperature section including the temperature detected by the air temperature detecting means, the inflow temperature detecting means, and the outflow on the basis of the detection result of the difference of the temperature detection means and is characterized that you determine the presence or absence of abnormality of the heat radiating portion.

  INDUSTRIAL APPLICABILITY The present invention can provide a cooling device that can suppress the occurrence of problems caused by an abnormality in a heat radiating part that radiates heat of a refrigerant that circulates between the heat receiving part.

1 is a schematic configuration diagram of a printer according to an embodiment. FIG. Explanatory drawing of the cooling device which concerns on FIG. Explanatory drawing about the cooling member which the cooling device of FIG. 2 has. FIG. 2 is an explanatory perspective view from the rear side of the printer according to FIG. 1. The perspective explanatory view which removed the external duct from the thermal radiation part of the cooling device which concerns on FIG. The graph of the time-dependent change of the inflow temperature of the cooling fluid which flows in into a radiator for every airflow temperature, and the outflow temperature of the cooling fluid which flows out of a radiator. FIG. 3 is a block diagram of a cooling control unit, each sensor, each movable member, a main body control unit, and the like provided in the cooling device according to the first embodiment. Explanatory drawing of the principle which judges abnormality of the thermal radiation part of Example 1. FIG. The control flow figure when judging abnormality of the thermal radiation part of Example 1. FIG. FIG. 6 is another example of an explanatory diagram of the principle for determining abnormality of the heat dissipating unit of the first embodiment. The another example of the control flow figure when judging abnormality of the thermal radiation part of Example 1. FIG. The control flow figure when judging abnormality of the thermal radiation part of Example 2. FIG. The graph of the temperature change of the cooling fluid which flows in into a radiator from the cooling member side of a heat receiving part, and the cooling fluid which flows out out of a radiator into a cooling member side for every kind of paper in M environment. The graph of the time-dependent change in the plain paper and cardboard of the inflow temperature of the cooling fluid which flows in into a radiator for every airflow temperature, and the outflow temperature of the cooling fluid which flows out from a radiator. FIG. 9 is a control flow diagram when determining an abnormality of the heat dissipation unit of the third embodiment. The graph which added H environment convergence outflow temperature used for judgment of cancellation of an image formation operation to the graph of a time-dependent change in plain paper of inflow temperature and outflow temperature of cooling fluid for every air current temperature. The control flow figure of another example when judging abnormality of the thermal radiation part of Example 3. FIG.

Hereinafter, an embodiment in which the present invention is applied to a cooling device provided in an image forming apparatus will be described with reference to the drawings. First, an outline of a printer 300 that is an image forming apparatus according to the present embodiment common to the respective examples will be described.
FIG. 1 is a schematic configuration diagram of a printer 300 according to the present embodiment.

  As shown in FIG. 1, the printer 300 according to this embodiment includes an intermediate transfer in the apparatus main body 200 by a plurality of rollers (first stretching roller 22, second stretching roller 23, third stretching roller 24, etc.). An intermediate transfer belt 21 as a body is stretched. The intermediate transfer belt 21 is configured to rotate in the direction of arrow a in the figure when one of the plurality of rollers is rotationally driven. In addition, the printer 300 has image forming process means disposed around the intermediate transfer belt 21. Here, the subscripts Y, C, M, and Bk added after the symbols indicate that the specifications are for yellow, cyan, magenta, and black.

  When the direction of rotation of the intermediate transfer belt 21 is indicated by an arrow a in the figure, an image is formed for each color between the first stretching roller 22 and the second stretching roller 23 above the intermediate transfer belt 21. As the process means, four image stations 10 (Y, C, M, Bk) are arranged. The Y image station 10Y, the C image station 10C, the M image station 10M, and the Bk image station 10Bk are arranged in this order from the upstream side in the surface movement direction of the intermediate transfer belt 21.

The four image stations 10 (Y, C, M, Bk) have substantially the same configuration except that the colors of the toners used are different.
In each image station 10, a charging device 5, an optical writing device 2, a developing device 3, and a photoconductor cleaning device 4 are arranged around a drum-shaped photoconductor 1. Further, a primary transfer roller 11 is provided as a toner image transfer unit to the intermediate transfer belt 21 at a position facing the photoconductor 1 across the intermediate transfer belt 21. Such four image stations 10 (Y, C, M, Bk) are arranged along the surface movement direction of the intermediate transfer belt 21 so as to have a predetermined pitch interval.
In this printer 300, the optical writing device 2 is an optical system using an LED as a light source. However, the optical writing device 2 can also be configured by a laser optical system using a semiconductor laser as a light source, and each photoconductor 1 is exposed according to image information. I do.

Below the intermediate transfer belt 21, a paper feed cassette 31, a paper feed roller 41, and a pair of registration rollers 42 for a sheet P as a sheet as a recording medium are arranged. In addition, secondary transfer as a toner image transfer unit from the intermediate transfer belt 21 to the paper P so as to face the third stretching roller 24 that stretches the intermediate transfer belt 21 via the intermediate transfer belt 21. A roller 25 is arranged. Further, a belt that cleans the front surface of the intermediate transfer belt 21 so that the cleaning facing roller 26 that contacts the back surface of the intermediate transfer belt 21 contacts the front surface of the intermediate transfer belt 21 at a position where it contacts the intermediate transfer belt 21. A cleaning device 27 is provided.
In FIG. 1, on the right side of the registration roller pair 42, a manual paper feed path 35, a manual paper feed roller 43, and a manual tray 34 for manual paper feeding are arranged.

  Further, a paper transport path 32 extending from the paper feed cassette 31 to the paper discharge tray 33 extends, and the downstream side of the secondary transfer roller 25 in the paper transport path 32 in the paper transport direction (hereinafter simply referred to as the downstream side) is heated. A fixing device 15 having a roller and a pressure roller is disposed. A heater (not shown) as a heating member is provided in the pressure roller of the fixing device 15 and functions as a heat source when the paper P is heat-fixed. A cooling device 100 that cools the paper P is disposed downstream of the fixing device 15 in the paper conveyance path 32. Outside the apparatus main body 200 further downstream of the cooling device 100, a paper discharge tray 33, which is a discharge portion for the paper P after heat fixing, is disposed. Further, when forming an image on the back side of the paper P during the double-sided image formation, the reverse side for forming the double-sided image that reverses the front and back of the paper P that has once passed through the cooling device 100 and transports the paper P to the registration roller pair 42 again. A conveyance path 36 is also provided.

In the apparatus main body 200, there is provided a main body control unit 210 (not shown) having a CPU (Central Processing Unit), a RAM (RAM), a ROM (ROM), a nonvolatile memory, a driver for each part, and the like. (See FIG. 7). Then, a program or the like stored in the ROM or nonvolatile memory is loaded into the RAM, and calculation is performed based on information from the external device, detection results of each sensor, and input data from the display / operation unit 220. It communicates with the control part and each device of each part, and performs the control. The display / operation unit 220 includes a touch panel type liquid crystal panel (hereinafter referred to as a touch panel), a click sound when operated, a warning sound generated when an abnormality occurs in each apparatus in the apparatus main body 200, and the like. Has a speaker to output.
When an abnormality occurs, the main body control unit 210 displays a warning on the display / operation unit 220, sounds a warning sound from a speaker, or abnormally transmits to a user's personal computer that is transmitting a signal such as a print job. Notify that has occurred and display a warning message. In other words, the main body control unit 210 has, as means for notifying the user, a touch panel, a speaker of the display / operation unit 220, a means for communicating with a user's personal computer or the like transmitting a signal such as a print job, and the like. ing.

Next, an image forming process of the printer 300 of this embodiment will be described.
The image forming process of the printer 300 will be described with respect to one image station 10. In accordance with a general electrostatic recording method, an optical writing device is formed on the photosensitive member 1 uniformly charged by the charging device 5 in the dark. 2 to form an electrostatic latent image. The electrostatic latent image is visualized as a toner image by the developing device 3. The toner image is transferred from the photoreceptor 1 to the intermediate transfer belt 21 by the primary transfer roller 11. The surface of the photoreceptor 1 after the transfer is cleaned by the photoreceptor cleaning device 4. Such an image forming process is performed in each of the four image stations 10 (Y, C, M, Bk).

  Each of the developing devices 3 (Y, C, M, Bk) in the four image stations 10 (Y, C, M, Bk) has a visible image forming function using different four color toners. For this reason, if each image station 10 (Y, C, M, Bk) shares yellow, cyan, magenta, and black, a full-color toner image can be formed. Further, each image station 10 includes a primary transfer roller 11 provided so as to face each photoconductor 1 with the intermediate transfer belt 21 interposed therebetween, and a transfer bias is applied to the primary transfer roller 11, and a primary transfer unit. Configure.

  With the above configuration, the same image forming area of the intermediate transfer belt 21 sequentially passes through the four image stations 10 (Y, C, M, Bk). During the sequential passage, the toner images are transferred one by one on the intermediate transfer belt 21 by the transfer bias applied to the primary transfer roller 11. As a result, when the same image forming area described above passes through the primary transfer portion of each image station 10 (Y, C, M, Bk) once, a full-color toner image is obtained by overlapping transfer in the same image area. be able to.

The full-color toner image formed on the intermediate transfer belt 21 in this way is transferred to the paper P conveyed from the paper feed cassette 31 or the manual feed tray 34, and the intermediate transfer belt 21 after transfer is transferred by the belt cleaning device 27. To be cleaned.
Here, the transfer of the full-color toner image from the intermediate transfer belt 21 to the paper P is performed as follows. During transfer, a transfer bias is applied to the secondary transfer roller 25 to form a transfer electric field between the secondary transfer roller 25 and the third stretching roller 24 via the intermediate transfer belt 21, and the secondary transfer roller 25. The sheet P is passed through the nip portion between the intermediate transfer belt 21 and the intermediate transfer belt 21. The paper P conveyed from the paper feed cassette 31 or the manual feed tray 34 is transferred onto the intermediate transfer belt 21 conveyed to the transfer nip portion by a registration roller pair 42 disposed upstream of the transfer nip portion in the paper conveyance direction. The toner image is conveyed to the transfer nip portion in accordance with the timing of the toner image.

After the transfer of the full-color toner image from the intermediate transfer belt 21 to the paper P, the full-color toner image carried on the paper P is fixed on the paper P by heating and pressing the fixing device 15 (hereinafter referred to as heat fixing). And a full-color final image is formed on the paper P. Thereafter, the paper P is cooled by a cooling device 100 having a belt conveying device that sandwiches and conveys the paper P and a cooling member 141 that is a heat receiving member provided on the inner peripheral surface of the conveying belt of the belt conveying device. Stacked on the paper tray 33. For this reason, when the paper P is stacked on the paper discharge tray 33, the toner on the paper P can be surely cured, and the paper P with insufficient cooling is stacked on the paper discharge tray 33. Can prevent the blocking phenomenon (hereinafter referred to as blocking).
Note that the printer 300 of this embodiment also functions as a multifunction machine having a copy function and a fax function by connecting an optional scanner unit (not shown) and a fax unit (not shown). Further, in addition to the paper feed cassette 31 provided in the apparatus main body 200, a paper feed table (not shown), which is a paper feed unit having a plurality of optional paper feed cassettes, is connected to the lower side of the apparatus main body 200 and the manual feed tray 34 side. can do.

Further, in this embodiment, in order to prevent the overlapping sheets P from sticking and blocking, which occurs when the sheet P after heat fixing is stacked on the sheet discharge tray while the temperature is high, the sheet P after heat fixing is used. An example applied to the cooling device 100 that cools the air will be described. However, the present invention is not limited to such a configuration.
For example, a cooling device that cools the heat generating part of the developing device in order to prevent the developer from agglomerating due to the frictional heat of the developer and the sticking of the stirring screw due to the frictional heat of the developer in the developing device. Applicable. In order to prevent the temperature in the image forming apparatus from exceeding the allowable temperature due to the frictional heat of the developer, the heat generated by the motor used in each process unit, and the heat generated by the heater of the fixing device. The present invention can also be applied to a cooling device or the like in which an arbitrary heat generating portion is a cooling target.

Next, a basic configuration and operation of the cooling device 100 included in the printer 300 according to the present embodiment, which is a feature of the present invention, will be described.
Here, in the following description, the side to which the toner is adhered in the softened state of the paper P heat-fixed by the fixing device 15 is referred to as the front side of the paper P unless it is particularly necessary to explain using individual terms. In the following description, the opposite side is called the back side of the paper P. Further, when describing the relative directions of the constituent members included in the printer 300 and the cooling device 100, in FIG. 1, the upstream side of the substantially horizontal paper transport path 32 in the paper transport direction is the right side, and the paper transport direction. The description will be made by referring to the downstream side as the left side. Further, the description will be made by referring to the paper surface, front side of FIG. 1 as the front side, and the back side of the paper as the rear side.
FIG. 2 is an explanatory diagram of the cooling device 100 according to the present embodiment, and FIG. 3 is an explanatory diagram of the cooling member 141 included in the cooling device 100 of FIG.

  As shown in FIG. 2, the cooling device 100 of the present embodiment serves as a nipping unit for nipping and conveying the sheet P after being heat-fixed by the fixing device 15 from the front side of the sheet P adhering in a softened state. A front-side clamping unit 160 for clamping and a back-side clamping unit 170 for clamping from the back side are provided. In addition, the heat receiving unit 140 provided in the front side clamping unit 160 is a metal (aluminum) cooling member that absorbs heat from the sheet P after fixing via the front side driven roller 162 provided in the front side clamping unit 160. 141. The cooling member 141 also includes a heat radiating section 180 having a radiator 181 that is a heat exchanger that radiates heat absorbed from the paper P. Then, the heat absorbed by the cooling member 141 is converted into a liquid flow path 143 (see FIG. 3), which is the internal flow path of the cooling member 141, and an internal flow path (liquid cooling) of the radiator 181. The circulation path is configured to be transported by circulating between the two.

  The front-side clamping unit 160 mainly includes four front-side driven rollers 162 arranged in a trapezoidal shape in the upper side of the sheet conveyance path 32 shown in FIG. 1, and the front-side conveyance spanned by these front-side driven rollers 162. A belt 161, a cooling member 141, and the like are included. On the other hand, the back-side clamping unit 170 mainly spans three back-side driven rollers 172 and drive rollers 173 arranged in a trapezoidal shape below the sheet conveyance path 32, and these back-side driven rollers 172 and drive rollers 173. It has a back side conveying belt 171 and the like.

The coolant circulation path is mainly composed of a fluid flow path part 143 of the cooling member 141, an internal flow path of the radiator 181, a liquid feed pump 182 for conveying the coolant, a liquid reservoir tank 183 for storing the coolant, and a rubber tube. 184 and the like. The rubber tube 184 functions as an external flow path for flowing the coolant by connecting the outlet of the upstream component in the conveyance direction of the coolant and the inlet of the downstream component, and forms the above-described circulation path. It is a pipe line which connects each component to be performed. The cooling liquid circulating in the cooling liquid circulation path has an internal flow path through which the cooling liquid flows the heat of the paper P absorbed from the cooling surface 142 of the cooling member 141 via the front conveying belt 161. It plays a role of heat transfer means for transferring to the radiator 181.
Here, as a coolant that is a refrigerant, a propylene glycol solution that contains water as a main component and is known as an antifreeze for lowering the freezing temperature is used. Also, ethylene glycol for lowering the freezing temperature based on water as the main component, and rust preventives for preventing rusting of metal parts (for example, phosphate substances: potassium phosphate, inorganic potassium, etc. ) And the like can also be suitably used.

As shown in FIG. 2, the radiator 181 is provided such that a plurality of cooling fins (not shown) are orthogonal to a plurality of refrigerant tanks provided in parallel in a substantially horizontal direction in the drawing. The coolant flowing in from the inlet of the radiator 181 is sequentially branched into the refrigerant tanks when flowing downward through the introduction path, flows in the refrigerant tanks from right to left in the figure, and sequentially joins in the outlet path. It flows out from the outlet provided in the upper part. Then, when the coolant passes through each refrigerant tank, each cooling fin, and the saddle material that forms the introduction path and the outlet path, the coolant passes through the ventilation portion between the members and contacts (contacts) the surface of each member. ) Heat exchange (heat radiation) with the outside air (air) to cool.
In the cooling device 100 of the present embodiment, the above-described radiator 181 is used. However, the type of the radiator is not limited to the above configuration, and the size, cost, and the size of the cooling device 100 and the printer 300 are not limited. It may be a format according to the required heat dissipation capacity.

Further, the heat radiating section 180 also has a fan unit 185 that is a blowing means for forcibly generating an airflow that hits the radiator 181 to improve the heat exchange efficiency between the coolant and the outside air and to increase the heat dissipating ability of the radiator 181. ing.
The fan unit 185 has eight blower fans 186 and a fan duct 194, and a fan duct opening 194a (see FIG. 5) formed in the fan duct 194 by airflow generated by rotationally driving each blower fan 186. It is applied to a radiator 181 provided opposite to the radiator 181. By applying the airflow in this way, the heat dissipation capability by the radiator 181 is increased, and the cooling capability of the cooling device 100 is increased.

  In addition to the fan duct opening 194a described above, the fan duct 194 has eight fan mounting openings 194b to which the blower fan 186 is attached. The gap between the opening except the opening through which the air flow generated by the blower fan 186 passes and the fan duct opening 194a is eliminated as much as possible. By eliminating the gap as described above, the air is connected to the air blowing opening of the internal duct 191 (see FIGS. 4 and 5) which is a duct for accommodating the radiator 181 and the liquid feed pump 182 and the like, and the inside of the internal duct 191 of each air blowing fan 186 The air blowing capacity is increased.

  The cooling member 141 provided in the heat receiving unit 140 is provided so as to cover the sheet width direction of the front-side conveyance belt 161 as shown in FIG. 3, and is a straight line portion substantially parallel to the sheet width direction of the liquid flow path unit 143. 2 are provided on the right side in the figure and one place on the left side in the figure. An inlet and an outlet of the liquid channel portion 143 are formed at the upstream and downstream sides of the liquid channel portion 143 in the sheet conveying direction, and at the left end portion in the drawing, and the rubber tube 184 from the heat radiating portion 180 is formed. Are connected to each other. Note that the folded portion of the liquid flow path section 143 described above has a maximum sheet width: in order to obtain a good cooling effect even when the maximum sheet width: W paper P is conveyed to the printer 300 of the present embodiment. It is provided outside the area where the W paper P is conveyed. In particular, the two folded portions on the right side in the drawing where the inlet and the outlet are not provided are provided on the outer side of the right end portion in the drawing of the front side conveyor belt 161.

  In the cooling device 100 configured as described above, the back-side driven roller 172 is rotationally driven counterclockwise in FIG. 2 to move the back-side conveyance belt 171 endlessly counterclockwise. Then, by the endless movement of the back side transport belt 171, the front side transport belt 161 that is in contact directly or via the paper P is endlessly moved clockwise. The sheet P is sandwiched and conveyed along the sheet conveyance path 32 by sandwiching the sheet P between the front-side conveyance belt 161 and the back-side conveyance belt 171 (hereinafter referred to as each conveyance belt) that move endlessly in this manner. Can do.

Then, the liquid feed pump 182 is driven to circulate the cooling liquid between the liquid flow path portion 143 of the cooling member 141 and the radiator 181 shown in FIG. 3, and indirectly contact the paper P via the front side conveying belt 161. The cooling surface 142 of the cooling member 141 to be cooled can absorb the heat from the paper P and cool it. More specifically, as described above, the cooling member 141 is provided with the liquid flow path portion 143 that is an internal flow path through which the cooling liquid passes, and is conveyed on the front side in contact with the cooling surface 142 of the cooling member 141. The coolant transports the heat (heat amount) absorbed from the paper P via the belt 161 to the outside. In this way, the cooling member 141 is kept at a low temperature.
Here, the cooling liquid is stored in the liquid storage tank 183, and after being sent by the liquid feed pump 182, the cooling liquid is radiated to the outside air when passing through the internal flow path of the radiator 181. As a result, the temperature decreases.

  The cooling liquid having a low temperature as described above absorbs heat from the cooling member 141 by heat transfer when passing through the liquid flow path portion 143 of the cooling member 141, and the high temperature cooling liquid is stored in the liquid storage tank 183. Return to. The coolant circulates between the liquid flow path portion 143 of the cooling member 141 and the internal flow path of the radiator 181 while driving the liquid feed pump 182, and heat radiation when passing through the radiator 181. The heat absorption at the time of passing through the liquid flow path part 143 of the cooling member 141 is repeated. Here, in the cooling device 100 of the present embodiment as described above, when the path through which the coolant circulates is based on, for example, the liquid feed pump 182, the liquid feed pump 182, the radiator 181, and the cooling member as described above. 141 and the liquid storage tank 183 are circulated in this order.

By circulating the coolant in this manner, the length of the path through which the coolant that has been radiated and is cooled when passing through the radiator 181 is sent to the cooling member 141 of the heat receiving unit 140 can be shortened. Therefore, it is possible to prevent the cooling performance of the cooling device 100 from being deteriorated due to the rise in temperature of the coolant that receives heat from the surface of the rubber tube 184.
By cooling the sheet P as described above, the temperature of the toner heated and fixed by the fixing device 15 and softened can be lowered, and the toner on the sheet P can be surely cured, and the discharge tray shown in FIG. Even if the sheet is discharged and loaded on 33, the occurrence of so-called blocking can be suppressed.

The cooling apparatus 100 is provided with a cooling control unit 230 that communicates with the main body control unit 210 and controls each drive motor and the like separately from the main body control unit 210 (see FIG. 7). Similar to the main body control unit 210, the cooling control unit 230 includes a central processing unit, a RAM, a ROM, a nonvolatile memory, a driver for each unit, and the like. And the program etc. which were memorize | stored in ROM or the non-volatile memory are loaded into RAM, a calculation is performed based on the information and control signal from the main body control part 210, and detection results of each sensor etc. Each part is controlled.
However, the present invention is not limited to such a configuration, and can be applied to a configuration in which the cooling control unit 230 is provided in the main body control unit 210.

Next, the structure of the heat radiating unit 180 provided in the cooling device 100 of the present embodiment will be described in more detail with reference to the drawings.
FIG. 4 is an explanatory perspective view from the rear side of the printer 300 according to the present embodiment. FIG. 5 is an explanatory perspective view in which the external duct 195 is removed from the heat radiation part 180 of the cooling device 100 according to the present embodiment.

  As shown in FIG. 2, the fan unit 185 which is a blowing unit of the present embodiment has eight blowing fans 186. This is because the cooling target of the cooling device 100 of this embodiment is the paper P after heat fixing, and the paper P used in the printer 300 corresponds to a wide variety of paper types from thin paper to thick paper. This is because the maximum amount of heat to be generated is larger than when the developing device 3 and the like are cooled. Then, as described above, in order to secure the intake air amount corresponding to the exhaust air amount by the eight blower fans 186 provided in the fan unit 185, the internal passage 191 has two of the first passage opening 192a and the second passage opening 192b. There are two passage openings.

First, with reference to FIG. 4, the arrangement of the heat radiating unit 180 and the relationship between the heat radiating unit 180 and the external duct 195 provided in the heat radiating unit 180, the exterior panel provided in the apparatus main body 200, and the like will be described.
As shown in FIG. 4, a heat dissipating part 180 is provided in the vicinity of the portion of the exterior panel provided in the apparatus main body 200 of the printer 300 that is in contact with the rear and left side surfaces. By providing the heat dissipating part 180 in this manner, outside air outside the apparatus main body 200 is sucked from the first passage opening 192a and the second passage opening 192b, which are two passage openings, and the fan mounting opening 194b of the fan unit 185 is provided. It is easy to exhaust from the main body 200 to the outside.

  Specifically, the fan unit 185 is protruded from the rear of the apparatus main body 200, the first passage opening 192 a of the internal duct 191 is disposed above the fan unit 185, and the internal duct 191 is disposed on the rear left side of the apparatus main body 200. The second passage opening 192b is disposed. An external duct 195 is connected to the rear of the first passage opening 192a and the fan unit 185, and the air after heat exchange is guided from the rear of the apparatus main body 200 to the first passage opening 192a and blown out from the fan unit 185. Is guided downward and rearward of the apparatus main body 200. In addition, an opening is provided in the exterior left panel of the apparatus main body 200 facing the second passage opening 192b, and outside air is guided to the second passage opening 192b from the left side of the apparatus main body 200.

  The outer duct 195 has a substantially rectangular parallelepiped shape, and the upper and left and right side walls are not provided with openings through which air passes, and the rear side walls are provided with a first outer opening 196a at the upper part, and the lower part. Is formed with a second external opening 197a. Then, by the external duct partition member 195a, a first external duct portion 196 that allows the air sucked from the first passage opening 192a to pass therethrough, and a second external duct portion 197 that is an external duct that allows the air blown from the fan unit 185 to pass therethrough, It is divided into.

  On the side of the internal duct 191 of the first external duct portion 196, the three side walls of the external duct 195 and the external duct partition member 195a are connected by four walls to the side wall of the internal duct 191 around the first passage opening 192a. A first external communication opening 196b is formed. On the other hand, the first external opening 196a is formed with a plurality of long holes for allowing air to pass therethrough and for preventing entry of foreign substances and the like. By configuring the first external duct portion 196 in this way, air that is sucked into the internal duct 191 from the space behind the external duct 195 protruding rearward of the apparatus main body 200 through the first passage opening 192a. A (outside air) flow path can be formed.

  On the side of the internal duct 191 of the second external duct portion 197, the second side wall is connected to the side wall of the internal duct 191 around the fan unit 185 with three walls by the two side walls of the external duct 195 and the external duct partition member 195a. An external communication opening 197b is formed. The second external communication opening 197 b communicates with a second external opening 197 a that is an opening at the lower part of the second external duct 197. In addition, the 2nd external opening part 197a of a present Example is attached with the metal net | network for letting air pass and suppressing the penetration | invasion of a foreign material. By configuring the second external duct portion 197 in this manner, the flow of air (outside air) exhausted from the internal duct 191 by the fan unit 185 to the space below the external duct 195 that protrudes rearward of the apparatus main body 200. A path can be formed.

  Also, a plurality of slits (which allow air to pass through the opening provided in the left exterior panel of the apparatus main body 200 so as to face the second passage opening 192b of the internal duct 191 and to prevent entry of foreign substances or the like ( A slit panel 199 provided (not shown) is attached. By configuring the periphery of the second passage opening 192b of the internal duct 191 in this way, the air (outside air) sucked into the internal duct 191 from the space on the left side of the apparatus main body 200 via the second passage opening 192b. The flow path can be formed. The slit panel 199 provided opposite to the second passage opening 192b is connected to the side wall of the internal duct 191 provided with the second passage opening 192b, and air flows from the space in the other apparatus main body 200. It is desirable to provide a partition member that does not.

Next, the configuration of the fan duct 194 and the internal duct 191 of the heat radiating unit 180 will be described in more detail.
FIG. 5 shows only main components related to the cooling device 100 provided in the printer 300. That is, the fixing device 15 that heats the sheet P to be cooled that is cooled by the cooling device 100, the front side clamping unit 160 in which the heat receiving unit 140 that absorbs heat from the heated paper P is disposed, and the front side clamping unit 160 They are the back side clamping part 170 and the heat radiating part 180 which are arrange | positioned.
In addition, the heat radiating section 180 includes a fan duct 194 that forms a heat radiating section casing 190, and an internal duct 191 that forms the heat radiating section 180 with the fan duct 194 and the eight fan fans 186. Is provided.

The internal duct 191 has a substantially rectangular parallelepiped shape, and a fan unit 185 is connected to the rear side wall, and a first passage opening 192a is formed above the fan unit 185. A two-pass opening 192b is formed. The first passage opening 192a includes five openings divided by four reinforcing members, and the second passage opening 192b includes four openings divided by the three reinforcing members.
In the fan unit 185, the blower fans 186 are respectively attached to the eight fan attachment openings 194 b on the rear side wall of the fan duct 194. A fan duct opening 194 a is provided on the side facing the fan mounting opening 194 b and is connected to the air blowing opening of the internal duct 191. A radiator 181 that is a heat exchanger is connected to the ventilation opening of the internal duct 191 from the inside so that the ventilation portion faces the fan duct opening 194a.

Next, the configuration and operation of the abnormality determination unit that determines the abnormality of the heat radiating unit 180, which is the largest characteristic part of the cooling device 100 of the present embodiment, will be described with reference to a plurality of examples.
In addition, about the cooling device 100 of each Example, the same code | symbol is attached | subjected and demonstrated about the same structural member or the structural member which has the same function, unless it distinguishes in particular.

Example 1
First, a configuration relating to an abnormality determination unit that determines an abnormality of the heat radiating unit 180 included in the cooling device 100 according to the present embodiment, and an operation (control) example 1 thereof will be described with reference to the drawings.
FIG. 6 shows the time of the airflow temperature of the airflow hitting the radiator 181 provided in the heat radiating section 180: the inflow temperature of the coolant flowing into the radiator 181: Rin and the outflow temperature of the coolant flowing out of the radiator 181: Rout for each T0. It is a graph of change. FIG. 7 is a block diagram of the cooling control unit 230, each sensor, each movable member, the main body control unit 210, and the like provided in the cooling device 100 of the present embodiment.

  FIG. 8 is an explanatory diagram of the principle of determining abnormality of the heat radiating unit 180 of the present embodiment, and FIG. 9 is a control flow diagram when determining abnormality of the heat radiating unit 180 of the present embodiment. FIG. 10 is another example of an explanatory diagram of the principle of determining an abnormality of the heat dissipation unit 180 of the present embodiment, and FIG. 11 is another example of a control flow diagram for determining an abnormality of the heat dissipation unit 180 of the present embodiment. .

In general, the temperature of the coolant flowing into the radiator 181 and the temperature of the coolant flowing out of the radiator 181 vary depending on the airflow temperature T0, which is the flow of air hitting the radiator 181.
For example, the environment when the airflow temperature hitting the radiator 181 is 15 ° C. is the L environment, the temperature of the coolant flowing into the radiator 181 is the L environment inflow temperature: RinL, and the temperature of the coolant flowing out of the radiator 181 is the L environment outflow Temperature: RoutL. Also, the environment when the airflow temperature is 24 ° C. is the M environment, the temperature of the coolant flowing into the radiator 181 is the M environment inflow temperature: RinM, and the temperature of the coolant flowing out of the radiator 181 is the M environment outflow temperature: RoutM And The environment when the airflow temperature is 32 ° C. is the H environment, the temperature of the coolant flowing into the radiator 181 is the H environment inflow temperature: RinH, and the temperature of the coolant flowing out of the radiator 181 is the H environment outflow temperature: RoutH And

The relationship of each temperature with respect to the time from the start of printing when defined as described above, that is, the time-dependent changes in the inflow temperature: Rin and the outflow temperature: Rout in each environment from the start of printing, When it is operating, it is as shown in FIG.
The difference between the coolant inflow temperature Rin and the coolant outflow temperature Rout in each environment flowing into the radiator 181 at this time is expressed by the following equation (1).
(RinL-RoutL)>(RinM-RoutM)> (RinH-RoutH) (Equation 1)
In addition, when the heat radiating unit 180 is in a normal state, each temperature described above converges to a certain temperature as time elapses. Here, in the following description, for example, the temperature at which the outflow temperature RoutH, which is the outflow temperature of the coolant in the H environment, converges as time elapses is indicated by the symbol RoutHe in FIG. That's it. Further, the temperature at which the outflow temperature: RinH, which is the inflow temperature of the coolant in the H environment, converges with time, is referred to as the H environment convergence inflow temperature: RinHe, which is indicated by the symbol RinHe in FIG.

  Therefore, in the cooling device 100 according to the present embodiment, the airflow, which is an air temperature detecting means for detecting the airflow temperature: T0, which is the temperature of the air before the heat exchange by hitting the radiator 181 provided in the heat radiating section 180 shown in FIG. The temperature sensor 151 was provided in the internal duct 191 shown in FIG. Specifically, in this embodiment, the radiator 181 provided in the internal duct 191 is provided immediately before the upstream in the airflow direction to take in outside air, but may be provided in the second passage opening 192b.

Also, in the vicinity of the inlet of the radiator 181, inside the rubber tube 184 surrounded by a solid line in FIG. 2 is an inflow temperature detecting means for detecting the inflow temperature: Rin of the coolant flowing into the radiator 181. An inflow temperature sensor 152 was provided. On the other hand, in the vicinity of the outlet of the radiator 181, inside the rubber tube 184 surrounded by a broken line circle in FIG. 2 is an outflow temperature detecting means for detecting the outflow temperature Rout of the coolant flowing out from the radiator 181. An outflow temperature sensor 153 was provided. In this embodiment, the inflow temperature sensor 152 and the outflow temperature sensor 153 are provided inside the rubber tube 184, but may be provided as follows. An inflow temperature sensor 152 and an outflow temperature sensor 153 are provided so as to detect a temperature of the outer surface of the metal tube by replacing part of the rubber tube 184 near the inlet and the outlet with a metal tube, and indirectly. The temperature of the internal coolant may be estimated.
The ROM of the cooling control unit 230 includes a cooling control unit as an abnormality determination unit that determines whether there is an abnormality in the heat radiating unit 180 based on the detection results of the airflow temperature sensor 151, the inflow temperature sensor 152, and the outflow temperature sensor 153. An abnormality determination program for functioning 230 is stored.

In this way, by configuring the cooling device 100, the following effects can be achieved.
When the heat receiving unit 140 is normal and the heat radiating unit 180 is normal, the inflow temperature: Rin and the outflow temperature: Rout are respectively shown in accordance with the elapsed time from the start of heat radiation by the heat radiating unit 180 for each airflow temperature: T0. 6 so as to draw a predetermined curve. Each converges to a certain temperature. For this reason, the cooling device 100 can maintain the cooling capability of sufficiently cooling the paper P by exhibiting the heat dissipation capability according to the airflow temperature T0.
On the other hand, when the heat receiving unit 140 is normal and the radiator 181 is clogged or the heat dissipating unit 180 is malfunctioning, the inflow temperature: Rin and the outflow temperature: Rout are respectively the predetermined curves described above. Changes to draw different curves. For this reason, the cooling device 100 cannot exhibit the heat dissipation capability according to the airflow temperature: T0, and cannot maintain the cooling capability for sufficiently cooling the paper P.

Therefore, in the cooling control unit 230, the value of the curve of the relationship between the detection result of the outflow temperature sensor 153 and the time of the environment inflow temperature: Rin and outflow temperature: Rout when the heat radiating unit 180 shown in FIG. 6 is normal. From this, the predicted inflow temperature of the coolant: Rin (P) is predicted. Then, by comparing the predicted predicted inflow temperature: Rin (P) with the detection result of the inflow temperature sensor 152, it is possible to appropriately determine the presence or absence of an abnormality in the heat radiating unit.
Therefore, the cooling control unit 230 that functions as an abnormality determination unit can determine whether the heat dissipation unit 180 is abnormal before the printer 300 continues to operate while the heat dissipation unit 180 is in an abnormal state and blocking occurs. .
Therefore, it is possible to provide the cooling device 100 capable of suppressing the occurrence of blocking, which is a malfunction, due to the abnormality of the heat radiating unit 180 that radiates the heat of the coolant circulating between the heat receiving unit 140 and the heat receiving unit 140.

  More specifically, as shown in FIG. 7, the cooling controller 230 is provided with a sensor controller that converts the detection value of each sensor into a signal that can be calculated in the cooling controller 230. On the other hand, in the non-volatile memory of the cooling control unit 230, the elapsed time from the start of heat dissipation by the heat dissipation unit 180 and the inflow temperature for each airflow temperature shown in FIG. And the information of the profile which digitized the relationship of outflow temperature: Rout was stored. Here, the heat release by the heat radiating unit 180 starts the printing operation (image forming operation) by the printer 300, and the cooling of the paper P that has passed through the fixing device 15 passes through the liquid flow path part 143 of the cooling member 141. This is when the liquid is transported to the radiator 181 to start heat dissipation.

Further, the temperature range detected by the airflow temperature sensor 151 is a time-dependent change information with respect to a curve of the relationship between the time of entry temperature: Rin and outflow temperature: Rout in each environment when the heat radiating unit 180 shown in FIG. 6 is normal. It was divided into temperature categories used as profiled thresholds.
In addition, the range and profile of each specific temperature division when using each profiled threshold value use the profile of the L environment when the airflow temperature: T0 is 15 ° C. or less which is the temperature of the L environment. In addition, when the airflow temperature T0 exceeds 15 ° C. which is the temperature of the L environment and is 24 ° C. or less which is the temperature of the M environment, the profile of the M environment is used. And when airflow temperature: T0 exceeds 24 degreeC which is the temperature of M environment, the profile of H environment is used.
The temperature classification and the profile of each environment described above are determined in advance and stored in the nonvolatile memory of the cooling control unit 230.

Then, when determining whether there is an abnormality in the heat radiating unit 180, the cooling control unit 230 loads the necessary profile from the nonvolatile memory into the RAM according to the detection result of the airflow temperature sensor 151, and stores the abnormality stored in the ROM. Judgment is performed by the CPU using a determination program.
By configuring in this way, the following effects can be achieved.
For each temperature category, obtain an estimated flow-in temperature: Rin (P) of the coolant that is predicted from the outflow temperature: Rout threshold profile and the outflow temperature: Rout when the heat radiating section 180 is normal. The predicted inflow temperature: Rin (P) can be compared with the detected inflow temperature: Rin.
When the detected inflow temperature Rin is equal to or higher than the predicted inflow temperature Rin (P), the radiator 181 dissipates a predetermined amount of heat, and the difference between the inflow temperature and the outflow temperature of the radiator 181 is equal to or greater than a predetermined value. It is thought that. Therefore, it can be determined that there is no abnormality in the heat radiating unit 180.

On the other hand, when the detected inflow temperature Rin is smaller than the predicted inflow temperature Rin (P), the radiator 181 does not dissipate a predetermined amount of heat, and the difference between the inflow temperature and the outflow temperature of the radiator 181 has a predetermined value. It seems that it is getting smaller. Therefore, it can be determined that the heat dissipating unit 180 is abnormal.
Therefore, the presence or absence of abnormality of the heat radiating unit 180 can be appropriately determined while reducing the calculation load when the CPU calculates using the abnormality determination program.

  In this embodiment, the curve of the relationship between the time of the inflow temperature: Rin and the outflow temperature: Rout is a profile that is time-varying information, and the predetermined temperature divisions are the three environments of L environment, M environment, and H environment. The profile and the example with three temperature ranges have been described. However, the present invention is not limited to such a configuration, and a temperature range divided for each predetermined temperature and a profile of the temperature environment at the boundary of each temperature range may be determined and held in advance.

In the liquid cooling type cooling device 100, it is ideal to detect the outflow temperature: Rout when the inflow temperature: Rin of the coolant that has flowed into the radiator 181 flows out. The difference in temperature is not negligible and the difference is negligible. Therefore, in this embodiment, the outflow temperature Rout of the coolant flowing out the radiator 181 is detected at the timing of detecting the inflow temperature Rin of the coolant flowing into the radiator 181.
If the detection is strictly performed, an outflow time T1 from inflow to outflow of the radiator 181 from the flow rate of the coolant and the volume of the radiator 181 is obtained. Then, an outflow time: Rout of the coolant flowing out of the radiator 181 after the elapse of time T1 after flowing into the radiator 181 may be detected.

Next, the principle and control flow when the cooling control unit 230 according to the present embodiment determines whether or not the heat radiation unit 180 has an abnormality using the abnormality determination program will be described with reference to FIGS. 8 and 9.
First, at the timing when printing (image formation) on the paper P of the printer 300 is started and heat dissipation of the heat of the coolant that has become high temperature in the heat receiving unit 140 is started to be released in the heat dissipation unit 180, the cooling control unit 230 Outflow temperature: Rout is acquired from the detection result of the outflow temperature sensor 153 (S101). Then, depending on whether or not the outflow temperature Rout is higher than the H environment convergence outflow temperature RoutHe shown in FIG. 6 (the outflow temperature: Rout is equal to or lower than the H environment convergence outflow temperature RoutHe), the image It is determined whether or not it is necessary to cancel the forming operation (S102).

  H environment convergence outflow temperature: Since RoutHe is a temperature in a high temperature H environment, when Rout is higher than this (No in S102), it is difficult to cool the paper P, and the image forming operation is stopped. It can be judged that it is necessary. Therefore, the cooling control unit 230 transmits a signal (communication) to the main body control unit 210 so as to immediately stop the image forming (printing) operation, and stops the image forming operation (S103). After that, the display / operation unit 220 shown in FIG. 7 displays that an abnormality has occurred via the main body control unit 210, sounds a warning sound from a speaker, and transmits a signal such as a print job. The user's personal computer or the like is notified that an abnormality has occurred (S104). Then, the control flow using the abnormality determination program is terminated.

  On the other hand, when the outflow temperature: Rout is equal to or lower than the H environment convergence outflow temperature: RoutHe (Yes in S102), it is determined that it is not necessary to stop the image forming operation, and the airflow temperature: T0 is determined from the detection result of the airflow temperature sensor 151. Obtain (S105). And the cooling control part 230 specifies the profile of the environment corresponding to the acquired airflow temperature: T0 from the non-volatile memory shown in FIG. 7, and loads it into RAM. It is assumed that this is the profile shown in FIG.

Next, the cooling control unit 230 predicts the coolant temperature that flows into the radiator 181 corresponding to Rout on the profile loaded in the RAM from the acquired outlet temperature: Rout (S101). Is acquired (S106).
Thereafter, the inflow temperature: Rin (actually measured value) is acquired from the detection result of the inflow temperature sensor 152 (S107).

Then, it is determined whether or not the inflow temperature Rin is equal to or higher than the predicted inflow temperature Rin (p) (S108). That is, a determination is made to compare the predicted inflow temperature: Rin (p) with the inflow temperature: Rin that is the detection result of the inflow temperature sensor 152.
In this determination, as shown on the right side of the graph of FIG. 8, the outflow temperature: Rout is Rout1, the predicted inflow temperature: Rin (p) is Rin (p) 1, the inflow temperature: Rin is the predicted inflow temperature: Rin (p). If Rin1 is 1 or more (Yes in S108), it can be determined as follows.
When the inflow temperature Rin1 is equal to or higher than the predicted inflow temperature Rin (p) 1, the radiator 181 dissipates a predetermined amount of heat, and the difference between the inflow temperature and the outflow temperature of the radiator 181 becomes a predetermined value or more. It can be determined that there is no abnormality in the heat dissipating unit 180. That is, the difference between the predicted inflow temperature: Rin (p) 1 and the outflow temperature: Rout1 is equal to or less than the difference between the inflow temperature: Rin1 and the outflow temperature: Rout1 (Rin (p) 1−Rout ≦ Rin−Rout ), It can be determined that there is no abnormality in the heat dissipating unit 180.

As described above, when it is determined that the inflow temperature: Rin is equal to or higher than the predicted inflow temperature: Rin (p) (Yes in S108), communication with the main body control unit 210 is performed to check whether the printing operation is continued. That is, it is determined whether or not the printing operation is completed (S110).
If it is determined that the printing operation has not been completed and is continuing (No in S110), the process returns to the acquisition of the outflow temperature (S101), and if it is determined that the printing operation has been completed. (Yes in S110), the control flow using the abnormality determination program is terminated.

On the other hand, as shown on the left side of the graph of FIG. 8, the outflow temperature: Rout is Rout2, the predicted inflow temperature: Rin (p) is Rin (p) 2, and the inflow temperature: Rin is from the predicted inflow temperature: Rin (p) 2. Can be determined as follows (No in S108).
When the inflow temperature: Rin2 is smaller than the predicted inflow temperature: Rin (p) 2, the radiator 181 does not dissipate a predetermined amount of heat, and the difference between the inflow temperature and the outflow temperature of the radiator 181 becomes smaller than a predetermined value. It can be determined that there is an abnormality in the heat dissipating unit 180. That is, the difference between the predicted inflow temperature: Rin (p) 2 and the outflow temperature: Rout2 is larger than the difference between the inflow temperature: Rin2 and the outflow temperature: Rout2 (Rin (p) 1-Rout> Rin− Rout), it can be determined that there is an abnormality in the heat dissipating unit 180.

As described above, when it is determined that the inflow temperature: Rin is smaller than the predicted inflow temperature: Rin (p) (No in S108), that is, when it is determined that the heat dissipating unit 180 is abnormal, the cooling control unit 230 The following control is performed. It is displayed on the touch panel of the display / operation unit 220 via the main body control unit 210 that the heat radiating unit 180 is abnormal, a warning sound is emitted from a speaker, or a user's personal computer is notified. A warning message is displayed (S109). However, since the heat radiation capability of the heat radiating unit 180 is not lowered to the extent that the printing operation (image forming operation) must be stopped (stopped), the printing operation continues.
Thereafter, communication with the main body control unit 210 is performed to determine whether the printing operation is continued, that is, whether the printing operation is finished (S110).
If it is determined that the printing operation has not been completed and is continuing (No in S110), the process returns to the acquisition of the outflow temperature (S101), and if it is determined that the printing operation has been completed. (Yes in S110), the control flow using the abnormality determination program is terminated.

As described above, in the cooling device 100 according to the present embodiment, the cooling control unit 230 having the abnormality determination program includes a plurality of L environments, M environments, H environments, and the like that classify the temperature ranges detected by the airflow temperature sensor 151. The temperature division is determined and held in advance. In addition, a threshold profile including an inflow temperature: Rin and an outflow temperature: Rout of the radiator 181 is also determined and held in advance in a state where the heat radiating unit 180 is operating normally for each temperature section. Then, the presence / absence of abnormality of the heat radiating unit 180 is determined based on the threshold value profile of the temperature classification including the airflow temperature: T0 detected by the airflow temperature sensor 151 and the detection results of the inflow temperature sensor 152 and the outflow temperature sensor 153. .
By determining in this way, the presence or absence of abnormality of the heat radiating unit can be appropriately determined while reducing the calculation load performed by the CPU of the cooling control unit 230.

In addition, as described above, the cooling control unit 230 determines whether there is an abnormality in the heat radiating unit 180 based on the difference between the detection results of the inflow temperature sensor 152 and the outflow temperature sensor 153.
By determining in this way, the heat dissipation capability in the heat dissipation part 180 is quantified from the difference between the detection results of the inflow temperature sensor 152 and the outflow temperature sensor 153, and the normal heat dissipation capability according to the detection result of the airflow temperature sensor 151 is obtained. It can be determined whether or not Therefore, the presence or absence of abnormality of the heat radiating unit 180 can be appropriately determined.

When the cooling control unit 230 determines that the heat radiation unit 180 has an abnormality, the cooling control unit 230 performs image formation (printing) on the paper P and communicates with the main body control unit 210 of the printer 300. Then, via the notification means such as the display / operation unit 220 to the user of the printer 300, the abnormality of the heat radiating unit 180 or more detailed information related to the abnormality can be notified.
Since the notification can be made in this way, the user can be notified of the abnormality of the heat radiating unit 180 and the maintenance (investigation) of the heat radiating unit 180 can be promoted. Accordingly, it is possible to suppress the occurrence of blocking, which is a malfunction, due to the operation of the printer 300 being continued with the abnormality of the heat radiating unit 180 left.

The cooling control unit 230 communicates with the main body control unit 210 of the printer 300 and relates to the paper P of the printer 300 when the detected outflow temperature Rout is not equal to or lower than the H environment convergence outflow temperature RoutHe in a normal state. Each image forming process is stopped.
By stopping each image forming process in this manner, the operation of the printer 300 using the cooling device 100 can be continued in a state where the abnormality of the heat radiating unit 180 is left, and the occurrence of blocking, which is a malfunction, can be reliably suppressed. .

In the above-described embodiment, an example in which the present invention is applied to the cooling device 100 that cools the paper P after heat fixing has been described. However, the present invention is not limited to such a configuration.
For example, the heat of the circulating coolant between the four image stations 10 in the printer 300 and the heat receiving unit having a cooling jacket brought into contact with the stirring / conveying unit of the developing device 3 respectively, The present invention is also applicable to a liquid cooling type cooling device having a cooling fan.

When such a cooling device for cooling the agitating / conveying unit of the developing device 3 is provided, if the heat radiating unit having the radiator and the blower fan is in an abnormal state, similarly to the cooling device 100 of the present embodiment described above, There is a problem that various problems occur. Specifically, the developer temperature in the developing device 3 rises and the softened toner aggregates to generate an abnormal image, or it adheres to any component in the developing device 3 and the developing device 3 fails. It is a problem that a malfunction occurs.
Then, by applying the present invention to the cooling device that cools the agitating / conveying unit of each developing device 3, the heat of the refrigerant circulating between the heat receiving unit and the malfunction caused by the abnormality of the heat radiating unit that radiates heat A cooling device capable of suppressing generation can be provided.

Moreover, although the cooling device 100 provided with the fan unit 185 having the blower fan 186 in the heat radiating unit 180 has been described, the present invention is not limited to such a configuration.
For example, it does not have a blowing means such as a blower fan, and naturally exhausts the airflow that has passed through the radiator and the intake port that takes in outside air so that the outside air passes through the ventilation section of the radiator The present invention can also be applied to a configuration in which a radiator is housed in a duct provided with an exhaust port.

In addition, the predicted inflow temperature: Rin (p) is acquired from the detected outflow temperature: Rout, and the predicted inflow temperature: Rin (p) is compared with the detected inflow temperature: Rin to determine whether there is an abnormality in the heat radiating unit 180. Although it was determined whether or not, the present invention is not limited to such a configuration.
For example, the predicted outflow temperature: Rout (p) is obtained from the detected inflow temperature: Rin, and the predicted outflow temperature: Rout (p) is compared with the detected outflow temperature: Rout to determine whether there is an abnormality in the heat radiating unit 180. It can also be determined whether or not.
Hereinafter, the principle and control flow when the cooling control unit 230 uses the abnormality determination program to determine whether or not the heat radiation unit 180 is abnormal will be described with reference to FIGS. 10 and 11. Note that the same points as the principle and control flow described with reference to FIGS. 8 and 9 will be omitted as appropriate.

  First, at the timing when printing (image formation) on the paper P of the printer 300 is started and heat dissipation of the heat of the coolant that has become high temperature in the heat receiving unit 140 is started to be released in the heat dissipation unit 180, the cooling control unit 230 The inflow temperature: Rin is acquired from the detection result of the outflow temperature sensor 153 (S101 ′). Then, depending on whether or not the inflow temperature: Rin is higher than the H environment convergence inflow temperature: RinHe shown in FIG. 6 (inflow temperature: Rin is less than or equal to the H environment convergence inflow temperature: RinHe), the image It is determined whether or not it is necessary to cancel the forming operation (S102 ′).

  H environment convergence inflow temperature: Since RinHe is a temperature in a high H environment, when Rin is higher than this (No in S102 ′), it is difficult to cool the sheet P, and the image forming operation is performed. It can be judged that it is necessary to cancel. Therefore, the cooling control unit 230 transmits a signal (communication) to the main body control unit 210 so as to immediately stop the image forming (printing) operation, and stops the image forming operation (S103). After that, the display / operation unit 220 shown in FIG. 7 displays that an abnormality has occurred via the main body control unit 210, sounds a warning sound from a speaker, and transmits a signal such as a print job. The user's personal computer or the like is notified that an abnormality has occurred (S104). Then, the control flow using the abnormality determination program is terminated.

  On the other hand, when the inflow temperature Rin is equal to or lower than the H environment convergence inflow temperature RinHe (Yes in S102 ′), it is determined that it is not necessary to stop the image forming operation, and the airflow temperature T0 is determined from the detection result of the airflow temperature sensor 151. Is acquired (S105). And the cooling control part 230 specifies the profile of the environment corresponding to the acquired airflow temperature: T0 from the non-volatile memory shown in FIG. 7, and loads it into RAM. Assume that this is the profile shown in FIG.

Next, the cooling control unit 230 predicts the coolant temperature flowing out from the radiator 181 corresponding to Rin on the profile loaded in the RAM from the acquired inflow temperature: Rin (S101 ′), and the predicted outflow temperature: Rout (p ) Is acquired (S106 ′).
Thereafter, the outflow temperature: Rout (actually measured value) is acquired from the detection result of the outflow temperature sensor 153 (S107 ′).

Then, it is determined whether the outflow temperature: Rout is equal to or lower than the predicted outflow temperature: Rout (p) (S108 ′). That is, a determination is made to compare the predicted outflow temperature: Rout (p) with the outflow temperature: Rout, which is the detection result of the outflow temperature sensor 153.
In this determination, it is assumed that the inflow temperature: Rin is Rin1 and the predicted outflow temperature: Rout (p) is Rout (p) 1, as shown on the right side of the graph of FIG. If the outflow temperature: Rout is Rout1 which is equal to or lower than the predicted outflow temperature: Rout (p) 1 (Yes in S108 ′), it can be determined as follows.

  When the outflow temperature: Rout1 is equal to or less than the predicted outflow temperature: Rout (p) 1, the radiator 181 dissipates a predetermined amount of heat, and the difference between the inflow temperature and the outflow temperature of the radiator 181 becomes equal to or greater than a predetermined value. Therefore, it can be determined that there is no abnormality in the heat dissipating unit 180. That is, the difference between the inflow temperature: Rin1 and the predicted outflow temperature: Rout (p) 1 is equal to or less than the difference between the inflow temperature: Rin1 and the outflow temperature: Rout1 (Rin−Rout (p) 1 ≦ Rin−Rout). ), It can be determined that there is no abnormality in the heat dissipating unit 180.

As described above, when it is determined that the outflow temperature: Rout is equal to or less than the predicted outflow temperature: Rout (p) (Yes in S108 ′), communication is performed with the main body control unit 210, and the printing operation is continued. It is determined whether or not the printing operation is finished (S110).
If it is determined that the printing operation has not been completed and continues (No in S110), the process returns to the acquisition of the inflow temperature (S101), and if it is determined that the printing operation has been completed. (Yes in S110), the control flow using the abnormality determination program is terminated.

On the other hand, as shown on the left side of the graph of FIG. 10, the inflow temperature: Rin is Rin2, the predicted outflow temperature: Rout (p) is Rout (p) 2, and the outflow temperature: Rout is from the predicted outflow temperature: Rout (p) 2. Is larger (No in S108 ′), it can be determined as follows.
When the outflow temperature Rout2 is larger than the predicted outflow temperature Rout (p) 2, the radiator 181 does not dissipate a predetermined amount of heat, and the difference between the inflow temperature and the outflow temperature of the radiator 181 becomes smaller than a predetermined value. It can be determined that there is an abnormality in the heat dissipating unit 180. That is, the difference between the inflow temperature: Rin2 and the predicted outflow temperature: Rout (p) 2 is larger than the difference between the inflow temperature: Rin2 and the outflow temperature: Rout2 (Rin2-Rout (p) 2> Rin− Rout), it can be determined that there is an abnormality in the heat dissipating unit 180.

As described above, when it is determined that the outflow temperature: Rout is larger than the predicted outflow temperature: Rout (p) (No in S108 ′), that is, when it is determined that the heat radiating unit 180 is abnormal, the cooling control unit 230 The following control is performed. It is displayed on the touch panel of the display / operation unit 220 via the main body control unit 210 that the heat radiating unit 180 is abnormal, a warning sound is emitted from a speaker, or a user's personal computer is notified. A warning message is displayed (S109). However, since the heat radiation capability of the heat radiating unit 180 is not lowered to the extent that the printing operation (image forming operation) must be stopped (stopped), the printing operation continues.
Thereafter, communication with the main body control unit 210 is performed to determine whether the printing operation is continued, that is, whether the printing operation is finished (S110).
If it is determined that the printing operation has not been completed and continues (No in S110), the process returns to the acquisition of the inflow temperature (S101), and if it is determined that the printing operation has been completed. (Yes in S110), the control flow using the abnormality determination program is terminated.

(Example 2)
A configuration relating to an abnormality determination unit that determines an abnormality of the heat radiating unit 180 included in the cooling device 100 of the present embodiment and Example 2 of the operation (control) will be described with reference to the drawings.
FIG. 12 is a control flow diagram when determining an abnormality of the heat dissipation unit 180 of the present embodiment.
This embodiment differs from the cooling device according to the first embodiment only in the following points. In the configuration relating to the abnormality determining means for determining the abnormality of the heat radiating unit 180 provided in the cooling device of the first embodiment, it is determined whether or not the heat radiating unit 180 is in an abnormal state. The notification is made to the user or the image forming operation of the printer 300 is stopped. On the other hand, in the configuration according to the abnormality determination unit of the present embodiment, any of the radiator 181 that is the heat exchanger included in the heat radiating unit 180 and the fan unit 185 (the blowing fan 186) that is the blowing unit is abnormal. It is the point which can distinguish and judge whether it is in a state.

  About the point which concerns on another thing, the structure of the abnormality determination means with which the cooling device 100 of a present Example was equipped, and the effect | action and effect of judging the abnormality of the thermal radiation part 180 are the same as that of the thing of Example 1. Therefore, in the following description, the same configuration, operation and effect will be omitted as appropriate. In addition, unless there is a particular need to distinguish, the same components and components having similar functions will be described using the same reference numerals and designations.

In this embodiment, in addition to determining whether there is an abnormality in the heat radiating unit 180, in order to distinguish and determine which of the radiator 181 that is a heat exchanger and the fan unit 185 that is a blowing means is in an abnormal state, The cooling device 100 and the cooling control unit 230 were configured as follows.
In the cooling device 100 according to the present embodiment, as the eight blower fans 186 provided in the fan unit 185, those that can output a rotation pulse signal are used, and the number of rotations of the blower fan 186 is acquired from the rotation pulse signal to release heat. This is used to determine whether or not the part 180 is abnormal.
Specifically, the cooling control unit 230 is provided with a terminal for connecting a terminal for a pulse signal of each blower fan 186 so that the rotation speed of the blower fan 186 can be acquired (detected) from the fan control roller, and cooling control is performed. A pulse detection circuit is provided in the fan controller of the unit 230.
In addition, a subroutine for determining whether or not the pulse signal detected by the pulse detection circuit is within an allowable frequency range according to the rotation speed of each blower fan 186 controlled by the cooling control unit 230 is added to the abnormality determination program. did.

Next, the control flow when the cooling control unit 230 according to the present embodiment determines whether or not the heat radiation unit 180 has an abnormality using the abnormality determination program will be described with reference to FIG.
In the present embodiment, the abnormality of the heat radiating unit 180 after determining that the inflow temperature: Rin of the first embodiment described with reference to FIG. 9 is smaller than the predicted inflow temperature: Rin (p) (No in S108). In place of the step of displaying or notifying (S109), the following steps were added.

As shown in the control flow diagram of FIG. 12, when the cooling control unit 230 determines that the inflow temperature: Rin is smaller than the predicted inflow temperature: Rin (p) (No in S108), the blower fan 186 rotates normally. It is confirmed whether or not (S201).
If the blower fan 186 does not rotate normally (No in S201), the abnormality of the heat radiating unit 180, that is, the reason why the heat of the coolant is not normally radiated is determined as the abnormality of the blower fan 186, and the blower fan 186 An abnormality is displayed or notified (S202).
On the other hand, when the blower fan 186 is rotating normally (Yes in S201), the radiator 181 may be clogged (the air resistance is increased). For this reason, the fact that the radiator 181 is abnormal is displayed or notified, and the user is urged to perform maintenance on the radiator 181, that is, check whether the radiator 181 is clogged (S 203).

By configuring as described above, it is possible to distinguish between the clogging of the radiator 181 and the abnormality such as the failure of the air blowing means, and it is possible to specify a more detailed inspection location and shorten the maintenance time of the heat radiating unit. Therefore, the downtime of the printer 300 using the cooling device 100 can be shortened and the operating rate can be increased.
In addition, the structure which concerns on the abnormality judgment means which judges the abnormality of the thermal radiation part 180 with which the cooling device 100 of a present Example was abnormal, and its operation | movement (control) cool another cooling object similarly to Example 1. FIG. The present invention can also be applied to a liquid cooling type cooling device.

(Example 3)
A configuration relating to an abnormality determination unit that determines an abnormality of the heat radiating unit 180 included in the cooling device 100 of the present embodiment, and an operation (control) example 3 thereof will be described with reference to the drawings.
FIG. 13 shows the temperature change of the coolant flowing into the radiator 181 from the cooling member 141 side of the heat receiving section 140 and the change over time of the coolant flowing out from the radiator 181 to the cooling member 141 for each type of paper in the M environment. It is a graph. FIG. 14 shows the temperature of the airflow hitting the radiator 181: the flow-in temperature of the coolant flowing into the radiator 181: Rin and the flow-out temperature of the coolant flowing out of the radiator 181: Rout for each T0 in plain paper and cardboard It is a graph of a time-dependent change.

FIG. 15 is a control flow diagram for determining an abnormality of the heat dissipating unit 180 of the present embodiment. FIG. 16 is a graph of the change over time of plain paper with the inflow temperature: Rin and the outflow temperature of the coolant: Rout for each airflow temperature: T0, and the H environment convergence outflow temperature used to determine whether to stop the image forming operation. Added graph. FIG. 17 is a control flow diagram of another example when determining an abnormality of the heat dissipating unit 180 of the present embodiment.
The step of acquiring the sheet type, which is a feature of the present embodiment, can be added to any of the control flows in FIG. 9 of the first embodiment and FIG. 12 of the second embodiment. FIG. 17 shows a case where a step of acquiring the paper type is added to FIG. 12 of the second embodiment.

This embodiment differs from the cooling devices according to the first and second embodiments only in the following points. In the present embodiment, in the configuration relating to the abnormality determining unit of the heat radiating unit 180 of the first and second embodiments, the type of paper is also added as a condition for determining whether or not the heat radiating unit 180 is in an abnormal state. It is.
About the point which concerns on another thing, the structure of the abnormality determination means with which the cooling device 100 of a present Example was equipped, and the effect | action and effect of judging the abnormality of the thermal radiation part 180 are the same as that of the thing of Example 1. FIG. Therefore, in the following description, the same configuration, operation and effect will be omitted as appropriate. In addition, unless there is a particular need to distinguish, the same components and components having similar functions will be described using the same reference numerals and designations.

First, the reason why the type of paper is added as a condition for determining whether or not the heat radiating unit 180 is in an abnormal state will be described.
The printer 300 is configured to be able to form images on a plurality of types of paper P. For example, thick paper, thick plain paper that is frequently used, and thin paper that is thin. The basis weight of these types of paper P varies depending on the thickness thereof, and the fixing temperature by the fixing device 15 varies depending on the type of paper set by a terminal such as a personal computer for which a user instructs printing. For example, the fixing temperature is higher for thick paper having a larger basis weight than that for fixing plain paper, and the fixing temperature is lower for thin paper having a smaller basis weight. For this reason, the temperature of the paper P after being thermally fixed by the fixing device 15 also differs depending on the type thereof, and the amount of heat received (absorbed) by the cooling member 141 is also different.

As described above, when the amount of heat received is different, the inflow temperature: Rin of the coolant flowing into the radiator 181 is different, and the inflow temperature: Rin and the coolant flowing out of the radiator 181 for each air temperature: TO. Outflow temperature: Rout varies with time.
For example, in the M environment, as shown in FIG. 13, as the paper thickness increases, the curvature of each temperature curve becomes tighter so that the convergence inflow temperature and the convergence outflow temperature become higher. In addition, there is a similar tendency in other temperature environments.
For example, the temperature curve of the time-dependent change graph of the inflow temperature: Rin and the outflow temperature: Rout in each temperature environment is higher than that of the plain paper shown in FIG. As the object becomes higher, the convergence value of each temperature curve also becomes higher.
For this reason, if the cooling device 100 that cools different types of paper P determines whether there is an abnormality in the heat radiating unit 180 based only on a profile of a certain paper type, an erroneous determination may be made.

Therefore, in this embodiment, the profiles stored in the non-volatile memory are not the profiles of the three sets (H environment, M environment, L environment) corresponding to the temperature classification shown in FIG. Nine sets of profiles defined for each paper and thin paper. Then, in order to load the necessary profile into the RAM as appropriate from the nine sets of profiles in the control flow for determining whether there is an abnormality in the heat radiating unit 180, information on the type of paper P from the main body control unit 210 is acquired. Added (S311 or S321).
In the control flow of the present embodiment, the control for acquiring the sheet type information from the main body control unit 210 by the cooling control unit 230 may be acquired at any of the following timings. The flow out temperature: Rout in FIG. 9 and FIG. 12 is acquired before acquiring (S101) (S311), or it is determined that it is not necessary to stop the image forming operation (Yes in S102), and the airflow temperature: T0 (S321) may be obtained before obtaining (S105).

Specifically, as shown in the control flow diagram of FIG. 15, when acquiring the outflow temperature: Rout (S101), when the printing on the paper P is started, the cooling control unit 230 Information on the type of paper P is acquired by communicating with the control unit 210 (S311). Then, the profiles necessary for the subsequent determination according to the type of the acquired paper P are loaded into the RAM, and the loaded profile is used.
For example, if the paper P to be cooled is plain paper, in the determination of stopping the image forming operation (S102), the H environment profile of plain paper corresponding to FIG. Convergent outflow temperature: RoutHe is extracted and compared with the acquired outflow temperature: Rout. Further, until it is determined that it is not necessary to stop the image forming operation (Yes in S102) and the end of printing is determined (S110), the profile corresponding to the type of the acquired paper P and the airflow temperature: T0 Each decision is made using.
That is, when the type information of the paper P to be cooled is acquired before S101, each determination is made using a profile that takes into account the paper type information after S102.

On the other hand, as shown in the control flow diagram of FIG. 17, it is determined that it is not necessary to stop the image forming operation (Yes in S102), and the airflow temperature: T0 is acquired (S105) before (S321). Then, communication with the main body control unit 210 is performed to acquire information on the type of the paper P (S321). In this case, in the determination of stopping the image forming operation (S102), the H environment profile of cardboard corresponding to FIG. 14B is loaded into the RAM, and the convergence outflow temperature: RoutHe of the H environment is extracted and acquired. Outflow temperature: Compared with Rout. Then, until it is determined that it is not necessary to stop the image forming operation (Yes in S102) and the end of printing is determined (S110), the profile corresponding to the type of the acquired paper P and the airflow temperature: T0 Each decision is made using.
That is, when the type information of the paper P is acquired between S102 and S105, in S102, the determination is made using the profile of the H environment corresponding to the thick paper P having the largest basis weight. Judgment is made using a profile that takes into account information.

With any one of the control flows described above, it is possible to make a more detailed determination according to the type (basis weight) of the paper P, and to suppress making an erroneous determination.
Here, the above-mentioned erroneous determination means that the paper P has a large basis weight, and thus exceeds the normal cooling temperature range when the basis weight is not taken into account (Rin (p) −Rout> Rin−Rout). That is, the control unit 230 determines that the heat radiation unit 180 is abnormal.

In addition, the structure which concerns on the abnormality judgment means which judges the abnormality of the thermal radiation part 180 with which the cooling device 100 of the present Example was equipped, and its operation | movement (control) are other cooling object similarly to Example 1,2. It can also be applied to a liquid cooling type cooling device that cools the liquid.
For example, the heat of the circulating coolant between the four image stations 10 in the printer 300 and the heat receiving unit having a cooling jacket brought into contact with the stirring / conveying unit of the developing device 3 respectively, The present invention is also applicable to a liquid cooling type cooling device having a cooling fan.

As described above, even in the printer 300 provided with the cooling device that cools the agitating / conveying unit of the developing device 3, the fixing temperature by the fixing device 15 varies depending on the type of paper set by a terminal such as a personal computer for which a user issues a print instruction. . For this reason, the temperature of the stirring / conveying unit of the developing device 3 also changes in accordance with the change in the environmental temperature in the printer 300, and the amount of heat received by the cooling jacket of the heat receiving unit also varies. For this reason, the inflow temperature of the coolant flowing into the radiator of the heat radiating unit is different, and the time-dependent changes in the inflow temperature and the outflow temperature of the coolant flowing out of the radiator for each airflow temperature are different. There is a risk of going.
Then, in the cooling device that cools the stirring / conveying unit of each developing device 3, when determining the presence / absence of abnormality in the heat radiating unit, any one of the above-described control flows is applied, and according to the type of the paper P More detailed determination can be made, and erroneous determination can be suppressed.

In the above-described embodiment, an example in which the present invention is applied to the printer 300 that is a color-compatible image forming apparatus has been described. However, the present invention is not limited to such a configuration.
For example, the present invention can also be applied to a monochrome image feed forming apparatus, a copying machine, a multifunction machine, and the like. Further, the present invention is not limited to an electrophotographic image forming apparatus, and can be applied to all electronic devices including a liquid cooling type cooling device using a cooling liquid.
That is, it is a cooling device that uses a coolant as a coolant and circulates the coolant between the heat receiving portion and the heat radiating portion, and can be applied to all electronic devices having a heat exchanger such as a radiator in the heat radiating portion.

What was demonstrated above is an example, and there exists an effect peculiar for every following aspect.
(Aspect A)
The coolant such as a coolant circulating between the heat receiving portion such as the heat receiving portion 140 that receives the heat to be cooled such as the paper P directly or indirectly via the front conveying belt 161 and the heat receiving portion. In a cooling device such as the cooling device 100 that includes a heat radiating unit such as the heat radiating unit 180 that radiates heat, air such as outside air that exchanges heat with the refrigerant in the heat radiating unit is subjected to heat exchange such as airflow temperature: T0. Air temperature detection means such as an airflow temperature sensor 151 that detects the previous temperature, inflow temperature detection means such as an inflow temperature sensor 152 that detects a refrigerant temperature flowing into the heat dissipation section from the heat receiving section, and the heat dissipation section Based on the detection results of the outflow temperature detecting means such as the outflow temperature sensor 153 for detecting the refrigerant temperature flowing out to the heat receiving section, the air temperature detecting means, the inflow temperature detecting means, and the outflow temperature detecting means. Te and is characterized in that it comprises, an abnormality determination means such as the heat radiating part of the cooling control unit 230 having an abnormality determining program that determines the presence or absence of an abnormality.

According to this, as described in the first embodiment (to 3), the following effects can be obtained.
When the amount of heat received by the heat receiving unit is constant and the heat radiating unit is normal, the refrigerant inflow and outflow temperatures in the heat radiating unit are the elapsed time from the start of heat radiation by the heat radiating unit for each temperature of the air before heat exchange with the refrigerant. Depending on the time, each changes so as to draw a predetermined curve and converges to a certain temperature. For this reason, the cooling device can maintain the cooling capability of sufficiently cooling the object to be cooled by exhibiting the heat dissipation capability according to the temperature of the air before heat exchange with the refrigerant in the heat dissipation portion.
On the other hand, even if the heat receiving amount of the heat receiving unit is constant, if the heat exchanger such as the radiator 181 is clogged or the heat dissipating unit such as the fan unit 185 is faulty, the refrigerant inflow and outflow temperatures are Each of them changes so as to draw a curve different from the predetermined curve described above. And a cooling device cannot exhibit the heat dissipation capability according to the temperature of the air before heat-exchanging with a refrigerant | coolant in a thermal radiation part, and cannot maintain the cooling capability which fully cools the cooling target.

Therefore, in the abnormality determination means, for example, from the detection result of the outflow temperature detection means and a predetermined curve of the refrigerant inflow temperature and outflow temperature when the heat dissipating part corresponding to the detection result of the air temperature detection means is normal, Predict the predicted inflow temperature. Then, by comparing the predicted predicted inflow temperature with the detection result of the inflow temperature detecting means, it is possible to appropriately determine whether there is an abnormality in the heat radiating unit.
Accordingly, the abnormality determination means determines whether or not there is an abnormality in the heat radiating unit before a device such as the printer 300 using the cooling device continues to operate while the heat radiating unit is in an abnormal state and a problem such as blocking occurs. it can.
Therefore, the cooling device which can suppress generation | occurrence | production of the malfunction resulting from abnormality of the thermal radiation part which thermally radiates the heat | fever of the refrigerant | coolant which circulates between heat receiving parts can be provided.

(Aspect B)
In (Aspect A), the abnormality determination means such as the cooling control unit 230 having the abnormality determination program is the detection result of the inflow temperature detection means such as the inflow temperature sensor 152 and the outflow temperature detection means such as the outflow temperature sensor 153. On the basis of the difference, it is determined whether there is an abnormality in the heat radiating part such as the heat radiating part 180.
According to this, as described in the first embodiment (to 3), the following effects can be obtained.
Determining whether normal heat dissipation capability is obtained according to the detection result of the air temperature detection means by quantifying the heat dissipation capacity at the heat dissipation part from the difference between the detection results of the inflow temperature detection means and the outflow temperature detection means It is possible to appropriately determine whether there is an abnormality in the heat radiating section.

(Aspect C)
In (Aspect B), the heat dissipating part such as the heat dissipating part 180 includes a heat exchanger such as a radiator 181 and an air blowing unit such as a fan unit 185 that forcibly generates a flow of air such as outside air hitting the heat exchanger. The abnormality determination means such as the cooling control unit 230 having an abnormality determination program, when the difference does not satisfy a predetermined condition, from the operation state such as the rotation speed of each blower fan 186 of the blower means, It is determined which of the heat exchanger or the air blowing means is abnormal.
According to this, as explained in Example 2 (or 3), it is possible to distinguish and judge the clogging of the heat exchanger and the abnormality such as the failure of the air blowing means, and specify a more detailed inspection location, Maintenance time of the heat dissipation part can be shortened. Therefore, the downtime of the apparatus such as the printer 300 using the cooling apparatus such as the cooling apparatus 100 can be shortened and the operation rate can be increased.

(Aspect D)
In any one of (Aspect A) to (Aspect C), the abnormality determination unit such as the cooling control unit 230 having the abnormality determination program classifies the temperature range detected by the air temperature detection unit such as the airflow temperature sensor 151. A plurality of temperature sections such as the L environment, the M environment, and the H environment, and an inflow temperature flowing into the heat exchanger in a state where the heat radiating unit is operating normally for each of the plurality of temperature sections: Rin And the time-dependent change information such as the temperature profile of the medium temperature flowing out from the heat exchanger, and the time-dependent change of the threshold value of the temperature section including the temperature detected by the temperature detecting means. Based on the information and the detection results of the inflow temperature detection means such as the inflow temperature sensor 152 and the outflow temperature detection means such as the outflow temperature sensor 153, It is characterized in that to determine the presence or absence of normal.

According to this, as described in the first embodiment (to 3), the following effects can be obtained.
For each temperature category, obtain the predicted inflow temperature of the refrigerant predicted from the temporal change information of the threshold value of the refrigerant temperature flowing out from the heat exchanger when the heat radiating unit is normal, and the detection result of the outflow temperature detecting means, This predicted inflow temperature can be compared with the detection result of the inflow temperature detecting means.
When the detection result of the inflow temperature detection means is equal to or higher than the predicted inflow temperature, the heat exchanger dissipates a predetermined amount of heat, and the difference between the inflow temperature and the outflow temperature of the heat exchanger is equal to or greater than a predetermined value. It can be judged that there is no abnormality in the heat dissipation part. On the other hand, when the detection result of the inflow temperature detection means is smaller than the predicted inflow temperature, the heat exchanger does not dissipate the predetermined amount of heat, and the difference between the inflow temperature and the outflow temperature of the heat exchanger is less than the predetermined value. It is thought that it has become small, and it can be judged that there is an abnormality in the heat dissipation part.
Therefore, the presence or absence of abnormality of the heat radiating portion can be appropriately determined while reducing the calculation load performed by the abnormality determination means.

(Aspect E)
In any one of (Aspect A) to (Aspect D), when the abnormality determination unit such as the cooling control unit 230 having the abnormality determination program determines that there is an abnormality in the heat dissipation unit such as the heat dissipation unit 180, the sheet The cooling target such as P is subjected to processing such as image formation, or is communicated with control means such as a main body control unit 210 of a device such as a printer 300 provided with the cooling target, and is displayed / operated for the user of the device. Through the notification means such as the unit 220, notification of information on the abnormality of the heat radiating unit or more detailed inspection points related to the abnormality is performed.
According to this, as described in the first embodiment (to 3), it is possible to notify the user of the abnormality of the heat radiating section and to promote maintenance (investigation) of the heat radiating section. Therefore, it is possible to suppress the occurrence of problems such as blocking by continuing the operation of the apparatus using the cooling device in a state where the abnormality of the heat radiating portion is left unattended.

(Aspect F)
In any one of (Aspect A) to (Aspect E), the abnormality determination means such as the cooling control unit 230 having an abnormality determination program is an outflow temperature of the outflow temperature detection means such as the outflow temperature sensor 153: Rout When the detection result does not satisfy a predetermined condition such as H environment convergence outflow temperature: RoutHe or less in a normal state, the cooling target such as paper P is subjected to processing such as image formation or the cooling target It communicates with control means such as a main body control unit 210 of an apparatus such as a printer 300 provided to stop operations such as image forming processes related to the cooling target of the apparatus.
According to this, as described in the first embodiment (to 3), it is possible to reliably suppress the occurrence of problems such as blocking by continuing the operation of the apparatus using the cooling device while leaving the abnormality of the heat radiating portion left unattended. it can.

(Aspect G)
In any one of (Embodiment E) to (Aspect F), an image forming apparatus such as a printer 300 in which the apparatus transfers a toner image onto a sheet such as paper P and heat-fixes the transferred toner image on the sheet. It is characterized by being.
According to this, as described in the first embodiment (to 3), the operation of the apparatus using the cooling device such as the cooling device 100 is continued in the state where the abnormality of the heat radiating portion such as the heat radiating portion 180 is left, and blocking is performed. It is possible to reliably suppress the occurrence of the problem.

(Aspect H)
In (Aspect G), the abnormality determination unit such as the cooling control unit 230 having the abnormality determination program is configured such that the heat radiating unit 180 or the like depends on the type of the sheet such as the sheet P such as thick paper, plain paper, and thin paper. It is characterized in that conditions such as a profile when judging whether or not there is an abnormality in the heat radiating portion are made different.
According to this, as described in the third embodiment, it is possible to make a more detailed determination according to the type (basis weight) of the sheet, and to suppress making an erroneous determination.

(Aspect I)
In (Aspect G) or (Aspect H), the object to be cooled is the sheet such as paper P.
According to this, as described in the third embodiment, it is possible to reliably suppress the occurrence of blocking due to the sheets that are undercooled being stacked on the stacking tray such as the discharge tray 33.

(Aspect J)
In an image forming apparatus, such as a printer 300, which forms an image on a sheet such as paper P and has a cooling unit that cools the sheet, or a heat generation location in an apparatus such as a stirring / conveying unit of the developing device 3. As the cooling device, a cooling device such as the cooling device 100 of any one of (Aspect A) to (Aspect I) is provided.
According to this, as described in the present embodiment, it is possible to provide an image forming apparatus that can achieve the same effects as any of the cooling devices of (Aspect A) to (Aspect I).

DESCRIPTION OF SYMBOLS 1 Photoconductor 2 Optical writing device 3 Developing device 4 Photoconductor cleaning device 5 Charging device 10 Image station 11 Primary transfer roller 15 Fixing device 21 Intermediate transfer belt 22 First tension roller 23 Second tension roller 24 Third tension roller 25 Secondary transfer roller 26 Cleaning counter roller 27 Belt cleaning device 31 Paper feed cassette 32 Paper transport path 33 Paper discharge tray 34 Manual feed tray 35 Paper feed path 36 Reverse paper transport path 41 Paper feed roller (paper feed cassette)
42 Registration roller pair 43 Manual feed roller 100 Cooling device 140 Heat receiving part 141 Cooling member 142 Cooling surface 143 Liquid flow path part 151 Air flow temperature sensor 152 Inflow temperature sensor 153 Outflow temperature sensor 160 Front side holding part 161 Front side conveyance belt 162 Front side driven roller 170 Back side clamping part 171 Back side conveyance belt 172 Back side driven roller 173 Drive roller 180 Heat radiation part 181 Radiator 182 Liquid feed pump 183 Liquid reservoir tank 184 Rubber tube 185 Fan unit 186 Blower fan 190 Heat radiation part casing 191 Internal duct 192 Passing opening 192a First One passage opening 192b Second passage opening 194 Fan duct 194a Fan duct opening 194b Fan mounting opening 195 External duct 195a External duct partition member 196 First external duct portion 196 First external opening 196b First external communication opening 197 Second external duct 197a Second external opening 197b Second external communication opening 199 Slit panel 200 Device main body 210 Main body control unit 220 Display / operation unit 230 Cooling control unit 300 Printer P Paper

JP 2012-098677 A

Claims (8)

In a cooling device comprising a heat receiving part that directly or indirectly receives heat to be cooled, and a heat radiating part that radiates heat of the refrigerant circulating between the heat receiving part,
Air temperature detecting means for detecting the temperature of the heat exchanged with the refrigerant in the heat radiating section before the heat exchange;
Inflow temperature detecting means for detecting a refrigerant temperature flowing into the heat radiating section from the heat receiving section;
Outflow temperature detection means for detecting the refrigerant temperature flowing out from the heat radiating section to the heat receiving section;
Includes an abnormality determination means for determining presence of an abnormality before Symbol radiating portion,
The abnormality determining means includes a plurality of temperature sections that divide a temperature range detected by the air temperature detecting means, and the heat radiating section is in a state where the heat radiating section is operating normally for each of the plurality of temperature sections. A temperature change information of a medium temperature flowing into the heat exchanger and a threshold value of the medium temperature flowing out from the heat exchanger is previously determined and held, and the temperature section including the temperature detected by the air temperature detecting means and aging information in the threshold, the inlet temperature detecting means and the on the basis of the difference between the outflow temperature detection means of the detection result, the cooling apparatus characterized that you determine the presence or absence of abnormality of the heat radiating portion. The cooling device according to claim 1 , wherein
The heat dissipating part has a heat exchanger and a blowing means for forcibly generating a flow of air hitting the heat exchanger,
The abnormality determining means determines whether the heat exchanger or the air blowing means is abnormal from the operating state of the air blowing means when the difference does not satisfy a predetermined condition. apparatus. The cooling device according to claim 1 or 2 ,
The abnormality determining means, when it is determined that an abnormality in the heat radiating portion is present, notification to the heating to the cooling target process performed apparatus or communicates with the control means of the apparatus comprising the cooling object, the device user The cooling device characterized by notifying the abnormality of the heat radiating section or information relating to the abnormality through the means. In the cooling device according to any one of claims 1 to 3 ,
The abnormality determination means, the detection result of the outlet temperature detecting means, when not satisfy the predetermined condition, communicates with the control means of the apparatus including the device or the cooling object subjected to a heat treatment to said cooling target, said device The cooling apparatus characterized by stopping the operation related to the cooling object. The cooling device according to claim 3 or 4 ,
A cooling apparatus, wherein the apparatus is an image forming apparatus that transfers a toner image onto a sheet and heat-fixes the transferred toner image onto the sheet. The cooling device according to claim 5 , wherein
The cooling device according to claim 1, wherein the abnormality determination unit changes a condition when determining whether or not there is an abnormality in the heat radiating unit according to the type of the sheet. The cooling device according to claim 5 or 6 ,
The cooling device, wherein the object to be cooled is the sheet. In an image forming apparatus provided with a cooling device that performs image formation on a sheet and generates heat in the apparatus or a sheet to be cooled,
Wherein as a cooling device, an image forming apparatus comprising the cooling device according to any one of claims 1 to 7.

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