JP5818130B2 - Cooled object and image forming apparatus - Google Patents

Description

  The present invention relates to an object to be cooled which is provided in an image forming apparatus main body and is cooled by a cooling device, and an image forming apparatus including the object to be cooled.

  In an image forming apparatus such as a copying machine, a printer, a facsimile, or a complex machine of these, various methods are employed as a method for recording an image such as characters and symbols on a recording medium such as paper or an OHP sheet. Among them, the electrophotographic method is widely used because it can form a high-definition image at high speed. In general, an image forming process in an electrophotographic image forming apparatus includes a process of reading image information with an optical device, a process of writing an electrostatic latent image on a photoconductor based on the read image information, And a step of supplying a toner from the developing device to form a toner image, a step of transferring the toner image formed on the photoreceptor to a recording medium, and a step of fixing the transferred toner image to the recording medium.

  It is known that when the image forming process is performed, the temperature in the apparatus rises due to heat generated by driving various apparatuses in the image forming apparatus, causing various adverse effects. For example, in an optical apparatus, a scanner lamp that scans a document and a scanner motor that drives the scanner lamp generate heat, and in a writing apparatus, a motor that rotates a polygon mirror at a high speed generates heat. In the developing device, frictional heat is generated when the toner is stirred and charged, and in the fixing device, a heater for thermally fixing the toner image generates heat. In the case of duplex printing, since the recording medium heated by the fixing device is sent to the conveyance path for duplex printing, the ambient temperature of the conveyance path rises. When the temperature in the apparatus rises due to these heats, the toner is softened and a defective image is generated. When the melted toner is hardened, the movable part in the developing apparatus is locked and a failure occurs. In addition, the temperature rise causes problems such as deterioration of oil such as bearings, shortening of the mechanical life of the motor, malfunction of IC on the electric board, failure, and deformation of resin parts having a low heat-resistant temperature. Conventionally, in order to prevent such an adverse effect due to temperature rise in the image forming apparatus, cooling is performed by an air cooling type cooling device using a cooling fan and a duct.

  However, in recent years, the number of heating elements provided in the image forming apparatus is increasing with an increase in the speed of processing such as printing. In addition, in order to achieve downsizing of the image forming apparatus, the density of its constituent parts is increased, and accordingly, it becomes difficult to optimize the airflow design inside the image forming apparatus, and the inside of the image forming apparatus is filled with heat. It has become easier. In addition, due to the demand for energy saving, toners having a low melting temperature have been developed in order to reduce energy consumption during image fixing. In particular, when a toner having a low melting temperature is used, the temperature inside the image forming apparatus increases. Need to be suppressed more than before. For these reasons, it is becoming difficult to obtain a sufficient cooling effect with the conventional air cooling system. Therefore, a liquid cooling type cooling device has been proposed as a cooling method with higher cooling capacity (for example, see Patent Document 1).

  In general, a liquid cooling type cooling device circulates a cooling liquid between a heat receiving portion disposed at a temperature rising portion of the image forming apparatus, a heat radiating portion that releases heat of the cooling liquid, and the heat receiving portion and the heat radiating portion. And a pump for feeding a coolant in the circulation path. By circulating the coolant between the heat receiving portion and the heat radiating portion by a pump, the heat absorbed by the heat receiving portion is radiated by the heat radiating portion. Unlike the air-cooled type, the liquid-cooled type cooling device transports heat with a liquid refrigerant (coolant) that has a larger heat capacity than air, so it has high heat-receiving characteristics and effectively cools the temperature rise points. Is possible.

  By the way, in the cooling device having the heat receiving portion, the cooling effect varies depending on the degree of adhesion between the heat receiving portion and the cooled object (temperature rise location). That is, when the heat receiving part and the object to be cooled are in close contact with each other and the contact area between them is large, the heat exchange rate between the object to be cooled and the heat receiving part is increased, and the cooling effect is also increased. On the other hand, if the shape of the contact surface between the heat receiving part and the object to be cooled does not match and an air layer is formed between the contact surfaces, the contact area between the two becomes smaller and the cooling effect decreases. .

  In order to avoid this, it is necessary to increase the flatness of the contact surface between the object to be cooled and the heat receiving portion. In addition, conventionally, by interposing a heat conductive sheet or grease between the cooled object and the heat receiving part, the air layer between the cooled object and the heat receiving part is filled to suppress a decrease in cooling effect. (For example, refer to Patent Document 2).

  However, raising the flatness of each contact surface between the body to be cooled and the heat receiving part has a problem of increasing the cost. Moreover, since the heat conductive sheet is usually composed mainly of a resin material, its heat conductivity is low. Furthermore, since a heat conductive sheet compensates those badness of flatness by being compressed between a to-be-cooled body and a heat receiving part, it needs to have a certain amount of thickness. For this reason, when a heat conductive sheet is used, there exists a problem that a heat exchange rate will fall remarkably as a whole. In addition, when grease is used, repainting is required when the grease deteriorates over time. Further, the use of grease has a problem that it is difficult to use in a location where a developer such as toner exists nearby.

  As described above, the conventional cooling method in which the heat receiving portion is brought into contact with the body to be cooled has various problems with respect to cost, heat exchange rate, and handleability. Such a problem is not limited to the liquid cooling method, but is a problem common to all cooling methods in which the heat receiving portion is brought into contact with the object to be cooled.

  Therefore, in view of such circumstances, the present invention is intended to provide a cooled object that can improve the cooling effect at low cost and has excellent handleability, and an image forming apparatus including the cooled object. .

The invention of claim 1 is a body to be cooled, which is provided on the image forming apparatus main body, is in contact with the heat receiving portion of the cooling device, and is cooled by a cooling medium circulating between the heat receiving portion and the heat radiating portion, A hole that penetrates from the outer surface side to the inner surface side is formed in the contact portion of the casing that contacts the heat receiving portion , and the hole portion is covered with a flexible member.

  With this configuration, when the heat receiving portion is brought into contact with the body to be cooled, the flexible member is deformed along the shape of the contact surface of the heat receiving portion, so that the heat receiving portion and the flexible member interpose an air layer. It is possible to contact without letting. As a result, a large contact area between the heat receiving portion and the flexible member can be ensured, and high heat receiving characteristics (heat exchange rate) can be obtained, so that the cooling effect can be improved.

  According to a second aspect of the present invention, in the body to be cooled according to the first aspect, the flexible member is disposed in a portion in contact with the developer, and at least the outermost surface on the developer side of the flexible member. The layer is a developer incompatible layer that does not dissolve the developer even when it comes into contact with the developer.

  Thereby, even if a developer contacts a flexible member, melt | dissolution of a developer and degradation accompanying this can be prevented.

According to a third aspect of the present invention, in the cooled object according to the first or second aspect, the flexible member is composed of a plurality of layers, and one of the layers is more thermally conductive than any of the other layers. It is a good heat conduction layer with good rate.

  Thereby, since the heat conductivity of a flexible member goes up, the heat receiving characteristic (heat exchange rate) between a heat receiving part and a flexible member increases, and it can improve a cooling effect.

According to a fourth aspect of the present invention, in the body to be cooled according to any one of the first to third aspects, the flexible member is composed of a plurality of layers, of which the outermost surface layer on the heat receiving portion side is It is a resin material layer having higher impact resistance or wear resistance than any other layer.

  Thereby, abrasion etc. of the flexible member by a heat receiving part contacting a flexible member can be suppressed, and the lifetime of a flexible member can be extended.

According to a fifth aspect of the present invention, in the cooled object according to any one of the first to fourth aspects, at least a part of the portion other than the contact portion that contacts the heat receiving portion is made to have a thermal conductivity higher than that of the contact portion. It is made of good material.

  Thereby, since the heat conductivity of parts other than the contact part of a to-be-cooled body goes up, a cooling effect can be improved.

  According to a sixth aspect of the present invention, there is provided a heat receiving portion that contacts a body to be cooled provided in the image forming apparatus main body, a heat radiating portion, and a circulation means for circulating a cooling medium between the heat receiving portion and the heat radiating portion. An image forming apparatus provided with a cooling device having the above-described configuration, wherein the object to be cooled is the object to be cooled according to any one of claims 1 to 5.

  Since the object to be cooled is the object to be cooled according to any one of claims 1 to 5, the object to be cooled can be effectively cooled, so that an abnormality associated with a temperature rise can be avoided. Is possible.

  According to a seventh aspect of the present invention, in the image forming apparatus according to the sixth aspect, the cooling device is a liquid cooling type cooling device that circulates the cooling liquid in a liquid state.

  As the cooling device, a liquid cooling type cooling device that circulates the cooling liquid in a liquid state can be applied.

  The invention according to claim 8 is the image forming apparatus according to claim 6, wherein the cooling device is a cooling device having a heat pipe.

  As the cooling device, a cooling device having a heat pipe can be applied. In this case, there is an advantage that a pump and a tank are not required.

  A ninth aspect of the present invention is the image forming apparatus according to the sixth aspect, wherein the cooling device is a vapor compression refrigeration device.

  As the cooling device, a vapor compression refrigeration device can be applied. Moreover, in this case, since the cooling medium is latent heat cooling in which the phase is changed between the liquid and the gas, the cooling is higher than the sensible heat cooling without the phase change between the liquid and the gas. An effect is obtained.

  The invention of claim 10 is the body to be cooled according to any one of claims 6 to 9, further comprising pressing means for pressing the heat receiving portion against the body to be cooled, and the reaction of the pressing force of the pressing means. It is configured to extend to a predetermined location of the object to be cooled.

  By applying the reaction of the pressing force of the pressing means to a predetermined part of the cooled body, the external force received by the cooled body due to the contact of the heat receiving part can be reduced, so that the position variation and deformation of the cooled body are suppressed. can do. Thereby, the function fall resulting from the position fluctuation | variation and deformation | transformation of a to-be-cooled body can be suppressed, and a function can be exhibited stably.

  In the present invention, by configuring the contact portion of the body to be cooled with the heat receiving portion with a flexible member, when the heat receiving portion contacts the body to be cooled, the flexible member has the shape of the contact surface of the heat receiving portion. Since it deform | transforms along, a flexible member and a heat receiving part can be made to contact without interposing an air layer. Thus, according to the present invention, since the contact area between the two objects can be increased without interposing a heat conductive sheet between the object to be cooled and the heat receiving part, the heat receiving characteristic (heat exchange rate) can be increased. Improve dramatically. As a result, the object to be cooled can be effectively cooled, and an abnormality associated with a temperature rise can be avoided.

  Moreover, according to this invention, the contact area between a to-be-cooled body and a heat receiving part can be increased, without using grease. For this reason, it is not necessary to perform a repainting operation such as when the grease is deteriorated, and the contact state between the body to be cooled and the heat receiving portion can be satisfactorily maintained over a long period of time. Furthermore, by not using grease, it becomes possible to install the heat receiving portion even in places where it is difficult to use grease, and the degree of freedom in layout of the arrangement of devices and members in the image forming apparatus is increased.

  In addition, according to the present invention, the contact area between the object to be cooled and the heat receiving part can be increased without securing the flatness of the contact area with high accuracy, so that the cooling effect can be reduced at a low cost. Improvements can be realized.

1 is a schematic cross-sectional view illustrating a configuration of an image forming apparatus according to an embodiment of the present invention. It is a schematic sectional drawing of a developing device and its peripheral structure. It is a figure which shows the state which made the heat receiving part contact the developing device. It is a figure which shows the state which spaced apart the heat receiving part from the image development apparatus. It is an expanded sectional view of a flexible film. It is an expanded sectional view of another flexible film. It is an expanded sectional view of another flexible film. It is a schematic sectional drawing of other embodiment of a developing device. It is a schematic block diagram of the cooling device which has a heat pipe. It is a schematic block diagram of a vapor compression refrigeration apparatus. FIG. 3 is a diagram illustrating a configuration when a toner bottle is a cooled body. It is a figure which shows the structure at the time of using the toner bottle of another structure as a to-be-cooled body. It is a figure which shows the structure at the time of using a sub hopper as a to-be-cooled body. FIG. 4 is a diagram illustrating a configuration when a toner conveyance path is a body to be cooled. It is a figure which shows the structure at the time of using a belt cleaning apparatus as a to-be-cooled body. It is a figure which shows the structure at the time of using a photoreceptor cleaning apparatus as a to-be-cooled body. It is a figure which shows the structure of this invention at the time of using a waste toner collection container as a to-be-cooled body.

  Hereinafter, embodiments according to the present invention will be described with reference to the drawings. In addition, in each figure, the same code | symbol is attached | subjected to the part which is the same or it corresponds, The duplication description is simplified or abbreviate | omitted suitably.

FIG. 1 is a schematic cross-sectional view showing a configuration of an image forming apparatus according to an embodiment of the present invention.
First, the overall configuration of the image forming apparatus will be described with reference to FIG.
The image forming apparatus 100 shown in FIG. 1 has four images that form images of different colors of yellow (Y), cyan (C), magenta (M), and black (Bk) corresponding to the color separation components of the color image. Forming portions 1Y, 1C, 1M, and 1Bk are provided. Each of the image forming units 1Y, 1C, 1M, and 1Bk has the same configuration except that it stores toners of different colors.

  Specifically, each of the image forming units 1Y, 1C, 1M, and 1Bk includes a drum-shaped photosensitive member 2 as a latent image carrier, a charging device 3 that charges the surface of the photosensitive member 2, and a surface of the photosensitive member 2. Are provided with a writing device 6 for forming an electrostatic latent image, a developing device 4 for forming a toner image on the surface of the photoconductor 2, and a photoconductor cleaning device 5 for cleaning the surface of the photoconductor 2. In FIG. 1, only the photoconductor 2, the charging device 3, the writing device 6, the developing device 4, and the photoconductor cleaning device 5 included in the yellow image forming unit 1 </ b> Y are denoted by reference numerals, and other image forming units are provided. Reference numerals are omitted in 1C, 1M, and 1Bk.

  A transfer device 7 is disposed below the image forming units 1Y, 1C, 1M, and 1Bk. The transfer device 7 has an intermediate transfer belt 10 constituted by an endless belt as a transfer body. The intermediate transfer belt 10 is stretched around a plurality of rollers, and the intermediate transfer belt 10 is configured to run around (rotate) when one of the rollers rotates as a driving roller.

  Four primary transfer rollers 11 as primary transfer means are disposed at positions facing the four photoconductors 2. Each primary transfer roller 11 presses the inner peripheral surface of the intermediate transfer belt 10 at each position, and a primary transfer nip is formed at a location where the pressed portion of the intermediate transfer belt 10 and each photoconductor 2 are in contact with each other. ing. Each primary transfer roller 11 is connected to a power source (not shown), and a predetermined direct current voltage (DC) and / or alternating current voltage (AC) is applied to the primary transfer roller 11.

  In addition, a secondary transfer roller 12 as a secondary transfer unit is disposed at a position facing one roller that stretches the intermediate transfer belt 10. The secondary transfer roller 12 presses the outer peripheral surface of the intermediate transfer belt 10, and a secondary transfer nip is formed at a location where the secondary transfer roller 12 and the intermediate transfer belt 10 are in contact with each other. Similar to the primary transfer roller 11, the secondary transfer roller 12 is connected to a power source (not shown) so that a predetermined direct current voltage (DC) and / or alternating current voltage (AC) is applied to the secondary transfer roller 12. It has become.

  In addition, the image forming apparatus 100 includes a paper feeding unit 13 that supplies a recording medium P such as paper or an OHP sheet to the secondary transfer nip, and a registration roller that adjusts the conveyance timing of the fed recording medium P. A pair 14 and a fixing device 8 that fixes an image on the recording medium P are provided.

An image forming operation of the image forming apparatus will be described with reference to FIG.
When the image forming operation is started, the photoreceptors 2 of the image forming units 1Y, 1C, 1M, and 1Bk are rotationally driven, and the surface of each photoreceptor 2 is uniformly charged to a predetermined polarity by the charging device 3. . Based on the image information of the document read by a reading device (not shown), the writing device 6 irradiates the charged surface of each photoconductor 2 with laser light, and forms an electrostatic latent image on the surface of each photoconductor 2. Is done. At this time, the image information written on the surface of each photoconductor 2 by the writing device 6 is monochromatic image information obtained by separating a desired full-color image into color information of yellow, cyan, magenta, and black. As the electrostatic latent image formed on the photosensitive member 2 is supplied with toner by each developing device 4, the electrostatic latent image is visualized (visualized) as a toner image.

  One of the rollers that stretch the intermediate transfer belt 10 is driven to rotate, causing the intermediate transfer belt 10 to run around. Also, a primary transfer nip between each primary transfer roller 11 and each photoreceptor 2 is applied to each primary transfer roller 11 by applying a constant voltage or a voltage controlled by a constant current opposite to the charging polarity of the toner. A transfer electric field is formed. Then, the toner images of the respective colors formed on the respective photoconductors 2 are sequentially superimposed and transferred onto the intermediate transfer belt 10 by the transfer electric field formed in the primary transfer nip. Thus, the intermediate transfer belt 10 carries a full-color toner image on its surface. Further, the toner on each photoconductor 2 that could not be transferred to the intermediate transfer belt 10 is removed by the photoconductor cleaning device 5.

  When the image forming operation is started, the recording medium P is supplied from the paper supply unit 13. The supplied recording medium P is temporarily stopped by the registration roller pair 14, then timed, and sent to the secondary transfer nip between the secondary transfer roller 12 and the intermediate transfer belt 10. At this time, a transfer voltage having a polarity opposite to the toner charging polarity of the toner image on the intermediate transfer belt 10 is applied to the secondary transfer roller 12, thereby forming a transfer electric field in the secondary transfer nip. Then, the toner images on the intermediate transfer belt 10 are collectively transferred onto the recording medium P by the transfer electric field formed in the secondary transfer nip. Thereafter, the recording medium P is sent to the fixing device 8 and the toner image is fixed on the recording medium P. Then, the recording medium P is discharged and stocked on a discharge tray (not shown) outside the apparatus.

  The above description is an image forming operation when a full-color image is formed on a recording medium. A single-color image is formed using any one of the four image forming units 1Y, 1C, 1M, and 1Bk. It is also possible to form a two-color or three-color image using two or three image forming units.

Next, the configuration of the cooling device according to the present invention will be described.
As shown in FIG. 1, the image forming apparatus 100 is provided with a cooling device 9 for cooling a temperature rise portion of the image forming apparatus. The cooling device 9 is a liquid cooling type cooling device. Specifically, the cooling device 9 includes four heat receiving units 31, three radiators 33 having a fan 34 as the heat radiating unit 30, a pump 32, and a tank 35, which are connected in series to supply coolant. It comprises a plurality of metal pipes 37 and a plurality of resin tubes 38 constituting a circulation path for circulation. In the example shown in FIG. 1, the coolant is circulated in the direction of the arrow. Note that the four heat receiving portions 31 may be connected in parallel. Further, the four heat receiving portions 31 are disposed in contact with the developing devices 4 included in the image forming portions 1Y, 1C, 1M, and 1Bk. As the cooling liquid, an antifreeze liquid containing a rust inhibitor is used.

The cooling device 9 operates as follows.
The cooling liquid cooled by the heat radiating unit 30 is sent to each heat receiving unit 31 by the pump 32. In each heat receiving portion 31, the heat of the corresponding developing device 4 is transmitted to the cooling liquid, and the developing device 4 is cooled. Further, the coolant whose temperature has risen in the heat receiving portion 31 due to the heat from the developing device 4 is sent again to the heat radiating portion 30 through the tank 35 and the pump 32 and cooled there. In this way, by circulating the coolant between the heat receiving unit 31 and the heat radiating unit 30, the cycle of heat absorption at the heat receiving unit 31 and heat dissipation at the heat radiating unit 30 is repeatedly performed. As a result, the temperature rise of the developing device 4 is suppressed and the occurrence of abnormal images is avoided. The tank 35 functions as a storage tank that temporarily stores the coolant from the radiator 33. This prevents large pressure fluctuations in the circulation path.

FIG. 2 is a schematic cross-sectional view of the developing device and its peripheral structure.
The developing devices included in the image forming units 1Y, 1C, 1M, and 1Bk and their peripheral structures are the same, and therefore, for convenience, one developing device 4 and its peripheral structures will be described in FIG.
As shown in FIG. 2, the developing device 4 has a casing 40, a developing roller 41 disposed at a location facing the photoreceptor 2 of the casing 40, and a thickness suitable for developing the developer supplied to the developing roller 41. A doctor blade 42 as a developer regulating means, a supply conveyance path 43 as a developer conveyance path disposed in the casing 40, a recovery conveyance path 44, an agitation conveyance path 45, the developer conveyance path 43, 44, 45, a supply screw 46, a recovery screw 47, a stirring screw 48, a concentration detection sensor (not shown) that detects the toner concentration in the developer, and the like. The developing roller 41 includes a magnet fixed inside, a sleeve that rotates around the magnet, and the like. In the supply conveyance path 43, the collection conveyance path 44, and the agitation conveyance path 45, a two-component developer G composed of a carrier and toner is accommodated. The developing device 4 may use a one-component developer composed only of toner instead of the two-component developer.

The developing device 4 operates as follows.
When the toner is replenished into the agitating / conveying path 45 by a toner replenishing device (not shown), the replenished toner is mixed and agitated with the developer by the agitating screw 48, and the shaft of the agitating screw 48 is passed through the agitating / conveying path 45. It is conveyed toward the direction. The developer transported to the downstream end of the stirring screw 48 in the transport direction is supplied to the supply transport path 43 through an opening (not shown).

  In the supply conveyance path 43 that receives the developer supplied from the agitation conveyance path 45, the developer is conveyed downstream in the conveyance direction of the supply screw 46 while supplying the developer to the developing roller 41. Then, the excess developer conveyed to the downstream end in the conveyance direction of the supply conveyance path 43 without being supplied to the developing roller 41 is supplied to the agitation conveyance path 45 through an opening (not shown).

  On the other hand, the developer supplied to the developing roller 41 is conveyed along with the rotation of the developing roller 41 in the direction of the arrow in FIG. 2 and reaches the position of the doctor blade 42. The developer on the developing roller 41 is conveyed to a position (development region) facing the photoconductor 2 after the developer amount is made appropriate at this position. Then, the toner is attracted to the latent image formed on the photoreceptor 2 by the electric field formed in the development area. Thereafter, the developer remaining on the developing roller 41 is separated / separated from the developing roller 41 and transferred to the collection conveyance path 44. The collected developer delivered from the developing roller 41 to the collection conveyance path 44 is conveyed to the downstream end in the conveyance direction of the collection conveyance path 44 by the collection screw 47 and is supplied to the agitation conveyance path 45 through an opening (not shown). .

  The surplus developer and the recovered developer supplied to the agitation conveyance path 45 are conveyed through the agitation conveyance path 45 while being mixed and agitated by the agitation screw 48 together with the appropriately supplied toner as described above, and again supplied and conveyed. Supplied to the passage 43. A toner concentration detection sensor including a magnetic permeability sensor (not shown) is provided below the agitation conveyance path 45, and the toner supply device is operated by the output of the sensor to supply the toner.

Next, with reference to FIG. 2, a support structure for the heat receiving portion 31 disposed in contact with the developing device 4 will be described.
The heat receiving portion 31 is held by the holding member 51. Specifically, a stepped screw 54 is loosely fitted in a hole 51 a provided in the holding member 51, and a screwed portion of the stepped screw 54 is screwed into a screw hole of the heat receiving unit 31. Further, a coil spring 55 that is an elastic member is wound around the step portion of the step screw 54. One end of the coil spring 55 is in contact with the holding member 51, and the other end is in contact with the bottom provided in the heat receiving portion 31. Accordingly, the heat receiving portion 31 is urged toward the developing device 4 by the coil spring 55 and is held by the holding member 51. In this embodiment, the elastic member that applies the pressing force is the coil spring 55, but the elastic member may be a leaf spring or a sponge that restores elastic force.

  The holding member 51 is supported by the support member 52 so as to be movable on the developing device 4 side and the opposite side. Specifically, the support member 52 has a pair of guide holes 52a and 52b at the upper and lower portions thereof, and pins 56a provided at the upper and lower portions of the holding member 51 in the guide holes 52a and 52b. , 56b are inserted. That is, the pins 56a and 56b are guided along the guide holes 52a and 52b, so that the holding member 51 moves to the developing device 4 side or the opposite side. As described above, in the present embodiment, the holding member 51 is configured to be movable to the developing device 4 side and the opposite side thereof, so that the heat receiving portion 31 can be contacted and separated from the casing 40 of the developing device 4. It has become. Further, in the casing 40 of the developing device 4, a portion with which the heat receiving portion 31 comes into contact is constituted by a flexible film (flexible member) 50.

  The support member 52 is attached to the frame 53 fixed to the image forming apparatus main body so as to be displaceable on the developing device 4 side and the opposite side. Specifically, a screw 57 is loosely fitted in a long hole 52 c formed in the support member 52, and the screw 57 is screwed into a screw hole (not shown) formed in the frame 53. In other words, the position of the elongated hole 52c is displaced with respect to the fixed screw 57, so that the support member 52 can be displaced to the developing device 4 side or the opposite side.

  Further, the support member 52 has two contact portions 52 d and 52 e that contact the casing 40 of the developing device 4. Specifically, the upper and lower portions of the casing 40 of the developing device 4 are respectively provided with contacted portions 40d and 40e protruding downward, and the support member 52 is provided with respect to the contacted portions 40d and 40e. The contact portions 52d and 52e are arranged so as to be able to contact each other. Further, the abutting portions 52d and 52e abut and separate from the abutted portions 40d and 40e as the support member 52 is displaced. That is, when the support member 52 is displaced toward the developing device 4, the contact portions 52 d and 52 e are separated from the contacted portions 40 d and 40 e, and conversely, the support member 52 is separated from the development device 4. In the case of displacement, the contact portions 52d and 52e contact the contacted portions 40d and 40e.

Hereinafter, the contact / separation operation of the heat receiving portion 31 will be described with reference to FIGS. 3 and 4.
FIG. 3 is a diagram illustrating a state in which the heat receiving unit is in contact (pressure contact) with the developing device, and FIG. 4 is a diagram illustrating a state in which the heat receiving unit is separated from the developing device.
When the heat receiving portion 31 is separated from the developing device 4, the holding member 51 is moved in a direction away from the developing device 4 by operating a lever (not shown). Thereby, as shown in FIG. 4, the heat receiving portion 31 held by the holding member 51 is separated from the developing device 4. In this state, the contact between the contact portions 52d and 52e of the support member 52 and the contacted portions 40d and 40e of the developing device 4 is released. As a result, the developing device 4 can be moved out in the direction perpendicular to the paper surface of FIG. 4 and taken out from the image forming apparatus main body. At this time, since the heat receiving portion 31 is separated from the flexible film 50 of the developing device 4, the heat receiving portion 31 does not rub against the flexible film 50 when the developing device 4 is taken out. Further, the flexible film 50 can be prevented from being damaged. Note that, here, the developing device 4 is described as being taken out alone, but the developing device 4 may be taken out as a process unit together with the photosensitive member or the like.

  On the other hand, when the heat receiving portion 31 is brought into contact (pressure contact) with the developing device 4, a holding member 51 is moved to the developing device 4 side by operating a lever (not shown). Thereby, as shown in FIG. 3, the heat receiving portion 31 contacts the developing device 4. At this time, the heat receiving portion 31 comes into contact with the flexible film 50 provided in the developing device 4. When the holding member 51 is further moved toward the developing device 4 from this state, the heat receiving portion 31 comes into pressure contact with the flexible film 50 by the pressing force F of the coil spring 55.

  In this state, the pins 56 a and 56 b of the holding member 51 are held in positions relative to the guide holes 52 a and 52 b of the support member 52. For this reason, the reaction force R opposite to the pressing force F applied to the heat receiving portion 31 by the holding member 51 from the coil spring 55 is transmitted to the support member 52 via the two pins 56a and 56b. As a result, the support member 52 is displaced in the direction of the reaction force R, that is, in the direction away from the developing device 4, and the contact portions 52d and 52e contact the contacted portions 40d and 40e, respectively. Then, the reaction force R received by the holding member 51 is transmitted to the support member 52 via the pins 56a and 56b, and thereby the contact forces T1 and T2 of the contact portions 52d and 52e with respect to the contacted portions 40d and 40e, and Acts. In this case, since these contact forces T1 and T2 act in the opposite direction to the pressing force F, the contact forces T1 and T2 and the pressing force F cancel each other.

  As described above, in this embodiment, the external force received by the developing device 4 due to the contact (pressure contact) of the heat receiving portion 31 is reduced by applying the reaction of the pressing force of the coil spring 55 to a predetermined portion of the developing device 4. Can do. As a result, the position fluctuation and deformation of the developing device 4 can be suppressed. As a result, the fluctuation of the distance (development gap) between the developing roller and the photosensitive member is suppressed, so that a high-quality image can be obtained over time. Can be maintained over time.

  In addition, since the location where the heat receiving portion 31 of the developing device 4 comes into contact is configured by the flexible film 50, the flexible film 50 is in the heat receiving portion when the heat receiving portion 31 is in contact (pressure contact) with the developing device 4. By being sandwiched between 31 and the developer G in the developing device 4, the flexible film 50 is deformed along the shape of the contact surface of the heat receiving portion 31. As a result, the contact surface of the heat receiving portion 31 and the flexible film 50, and the flexible film 50 and the developer G stored therein are in close contact with each other without interposing an air layer. That is, since a large contact area between the heat receiving portion 31 and the flexible film 50 and between the flexible film 50 and the developer G can be ensured, high heat receiving characteristics (heat exchange rate) are obtained. The cooling effect can be improved.

FIG. 5 is an enlarged cross-sectional view of the flexible film.
In the flexible film 50 shown in FIG. 5, the outermost surface layer 50a on the developer G side is composed of a developer-incompatible layer made of a material that does not dissolve the developer even when it comes into contact with the developer. As a result, even when the developer contacts the flexible film 50, the developer is not dissolved or deteriorated, and a high-quality image can be maintained over time. Examples of the material used for the developer incompatible layer include polyethylene terephthalate, polypropylene, and polyethylene.

FIG. 6 is an enlarged cross-sectional view of another flexible film.
In the flexible film 50 shown in FIG. 6, the intermediate layer 50 b is formed of a metal layer, and is a good heat conductive layer with good thermal conductivity. Thereby, since the thermal conductivity of the flexible film 50 increases, the heat receiving characteristics between the heat receiving portion 31 and the flexible film 50 and between the flexible film 50 and the developer G are enhanced, and the cooling effect is increased. Can be improved. Moreover, you may comprise a good heat conductive layer with materials with favorable heat conductivity other than a metal. Also in this case, as described above, it is desirable that the outermost surface layer 50a on the developer G side be a developer incompatible layer.

FIG. 7 is an enlarged cross-sectional view of still another flexible film.
In the flexible film 50 shown in FIG. 7, the outermost surface layer 50c on the heat receiving portion 31 side is formed of a resin material layer having at least one of impact resistance and wear resistance. Thereby, abrasion etc. of the flexible film 50 by the heat receiving part 31 contacting the flexible film 50 can be suppressed, and the lifetime of the flexible film 50 can be extended. Moreover, as a material used for this resin material layer, a polyethylene terephthalate, a polypropylene, polyethylene, etc. are mentioned. Also in this case, it is desirable that the outermost surface layer 50a on the developer G side be a developer incompatible layer, and the intermediate layer 50b may be composed of a heat conductive layer such as a metal layer.

FIG. 8 is a schematic cross-sectional view of another embodiment of the developing device.
The developing device 4 shown in FIG. 8 is a portion other than the contact portion (flexible film 50) with which the heat receiving portion 31 of the casing 40 comes into contact, and a portion 40f thereof is made of a metal material having a good thermal conductivity. Thereby, the heat receiving characteristics between the portion 40f made of the metal material and the developer G are enhanced, and the cooling effect can be improved. Moreover, you may comprise a part of casing 40 with materials with favorable heat conductivity other than a metal. Other configurations are the same as those of the developing device 4 of the above embodiment.

In addition, a cooling device having a heat pipe can be used as the cooling device 9.
As shown in FIG. 9, a heat receiving portion 31 is provided at one end of the heat pipe 59, and a heat radiating portion 30 having a fan 34 and a radiator 33 is provided at the other end. The cooling medium (hydraulic fluid) accommodated in the heat pipe 59 evaporates by absorbing heat at the heat receiving portion 31 and becomes vapor, and when the vapor moves to the heat radiating portion 30, it dissipates heat and condenses and liquefies. Then, the liquefied cooling medium moves again to the heat receiving part 31 and circulates in the heat pipe 59. As means for circulating the cooling medium in the heat pipe 59 (cooling medium circulation means), known means such as gravity, capillary phenomenon, or pressure vibration generated by self-excitation due to the pressure difference between the heat receiving portion 31 and the heat radiating portion 30 are known. Means can be used. Moreover, the cooling method using a heat pipe has an advantage that a pump and a tank are not required, compared to the liquid cooling type in which the cooling liquid shown in the above embodiment is circulated in a liquid state. However, the cooling effect is greater in the liquid cooling method than in the cooling method using a heat pipe.

Further, as the cooling device 9, a vapor compression refrigeration device may be used.
As shown in FIG. 10, the vapor compression refrigeration apparatus (cooling device 9) includes a heat receiving part 31, a compressor 61, an expansion valve 62, a fan 34 and a radiator 33, and circulates these components. It is connected with the pipes that make up the road. In this case, the cooling medium absorbs heat at the heat receiving unit 31 and changes from liquid to vapor, and then becomes high-temperature and high-pressure vapor by the compressor 61 and is sent to the heat radiation unit 30. The high-temperature and high-pressure steam sent to the heat radiating unit 30 is cooled, condensed and liquefied, depressurized and reduced in temperature by the expansion valve 62, and sent to the heat receiving unit 31 again. As described above, when the vapor compression refrigeration apparatus is used, the cooling medium is latent heat cooling in which the cooling medium is cooled by changing the phase between the liquid and the gas. Compared to sensible heat cooling without phase change at, high cooling effect is obtained.

  In the above-described embodiment, the object to be cooled by the cooling device is the developing device, but other devices or members can be the object to be cooled.

FIG. 11 is a diagram illustrating a configuration in the case where a toner bottle (developer container) is a cooling target.
A toner bottle 65 shown in FIG. 11 has a cylindrical casing 66 for containing toner. In this case, a part of the casing 66 of the toner bottle 65 is constituted by the flexible film 67, and the heat receiving part 31 of the cooling device is brought into contact with the part constituted by the flexible film 67. In the present embodiment, the casing 66 rotates as shown by the arrow in FIG. 11 so that the toner inside is conveyed and discharged from a toner discharge port (not shown). 67 is provided over the entire circumference. With this configuration, the heat receiving portion 31 is always in contact with the flexible film 67 even when the toner bottle 65 rotates. As a result, the contact surface of the heat receiving portion 31 and the flexible film 67, and the flexible film 67 and the accommodated toner adhere to each other without interposing an air layer. As a result, a large contact area between them can be secured, high heat receiving characteristics (heat exchange rate) can be obtained, and the cooling effect can be improved. Note that when the flexible film 67 is provided over the entire circumference as in the present embodiment, the strength of the toner bottle 65 decreases as it is, so that the reinforcing member 68 is provided in the casing 66 as shown in FIG. It is better to reinforce it.

FIG. 12 is a diagram illustrating a configuration in the case where a toner bottle having another configuration is used as a cooling target.
In the toner bottle shown in FIG. 12, the entire casing 71 is formed of a flexible film 69. In this case, by bringing the heat receiving portion 31 of the cooling device into contact with the side surface of the casing 71 of the toner bottle 70, the heat receiving portion 31, the casing 71 (flexible film 69), and the toner in the casing 71 are removed as described above. Adhesion can be achieved without interposing an air layer, and high heat receiving characteristics (heat exchange rate) can be obtained. However, the toner bottle 70 in which the casing 71 is entirely made of a flexible film as described above can be easily deformed, so that the heat receiving portion 31 can be brought into contact with the toner bottle 70 with a sufficient pressing force. It may not be possible. In that case, by providing a reinforcing member such as a rigid frame in the casing 71, the entire shape of the toner bottle 70 can be maintained to some extent, and the heat receiving portion 31 can be brought into contact with the toner bottle 70 with sufficient pressing force. Good.

FIG. 13 is a diagram illustrating a configuration in which a sub hopper of a toner replenishing device that replenishes toner from a toner bottle to a developing device is a cooled object.
The toner replenishing device shown in FIG. 13 includes a sub hopper 76 as a temporary storage unit that temporarily stores toner, and a MONO pump 77 that is a powder pump. The Mono pump 77 is connected to the toner bottle 64 through a tube 78 constituting a toner conveyance path. Further, the MONO pump 77 communicates with the developing device via the sub hopper 76. In the sub hopper 76, a stirring unit 81 and a stirring screw 82 for stirring the stored toner are disposed. In this case, the toner in the toner bottle 64 is stored in the sub hopper 76 via the tube 78 by driving the MONO pump 77. The toner stored in the sub hopper 76 is supplied to the developing device according to the image output in order to keep the toner density inside the developing device within a certain range.

  Here, in the toner replenishing device configured as described above, a part of the casing 79 of the sub hopper 76 is configured by the flexible film 80, and the heat receiving portion of the cooling device is formed in the portion configured by the flexible film 80. 31 is in contact. Thereby, the toner in the heat receiving part 31, the flexible film 80, and the sub hopper 76 can be closely contacted without interposing an air layer, and high heat receiving characteristics (heat exchange rate) can be obtained.

FIG. 14 is a diagram illustrating a configuration in a case where a toner transport path (developer transport path) disposed in the image forming apparatus is a cooling target.
In this case, as shown in FIG. 14, the toner conveyance path 83 has a cylindrical casing 83 that accommodates a toner conveyance means 86 such as a screw or a coil, and a part of the casing 83 is flexible. It is comprised by the property film 85. And the heat receiving part 31 of a cooling device is made to contact the part comprised by this flexible film 85. FIG. Thereby, the toner conveyed in the heat receiving part 31, the flexible film 85, and the casing 83 can be stuck without interposing an air layer, and a high heat receiving characteristic (heat exchange rate) can be obtained. .

FIG. 15 is a diagram illustrating a configuration in which a belt cleaning device that removes residual toner on the intermediate transfer belt is a cooling target.
A belt cleaning device 87 shown in FIG. 15 includes a casing 90, a cleaning brush 88 and a cleaning blade 89 as cleaning means, and a toner recovery coil 91. In this case, when the intermediate transfer belt 10 moves (rotates) in the direction of the arrow in FIG. 15, the toner remaining on the intermediate transfer belt 10 is removed and removed by the cleaning brush 88 and the cleaning blade 89 that are in contact with the intermediate transfer belt 10. The toner thus stored is accommodated in the casing 90. As the toner recovery coil 91 rotates, the toner in the casing 90 is conveyed to a waste toner recovery container (not shown).

  Here, in the belt cleaning device 87 configured as described above, a part of the casing 90 is configured by the flexible film 92, and the heat receiving portion 31 of the cooling device is provided in the portion configured by the flexible film 92. It is in contact. As a result, the toner in the heat receiving portion 31, the flexible film 92, and the casing 90 can be brought into close contact with each other without interposing an air layer, and high heat receiving characteristics (heat exchange rate) can be obtained.

FIG. 16 is a diagram showing a configuration in the case where a photosensitive member cleaning device that removes residual toner on the photosensitive member is a cooled object.
A photoreceptor cleaning device 93 shown in FIG. 16 includes a casing 94, a cleaning brush 95 and a cleaning blade 96 as a cleaning unit, and a toner recovery coil 97. In this case, when the photosensitive member 2 rotates in the direction of the arrow in FIG. 16, the toner remaining on the photosensitive member 2 is removed by the cleaning brush 95 and the cleaning blade 96 contacting the photosensitive member 2, and the removed toner is removed from the casing 94. Housed inside. As the toner recovery coil 97 rotates, the toner in the casing 94 is conveyed to a waste toner recovery container (not shown).

  Here, in the photoconductor cleaning device 93 configured as described above, a part of the casing 94 is configured by the flexible film 98, and the heat receiving portion 31 of the cooling device is formed in the portion configured by the flexible film 98. Are in contact. As a result, similarly to the belt cleaning device 87, the toner in the heat receiving portion 31, the flexible film 98, and the casing 94 can be brought into close contact without an air layer interposed therebetween, and high heat receiving characteristics (heat exchange rate). Is obtained.

FIG. 17 is a diagram showing a configuration when a waste toner collection container (developer collection container) for collecting waste toner is used as a cooled object.
As described above, the waste toner removed by the belt cleaning device 87 and the photoconductor cleaning device 93 is conveyed by the toner conveyance path 120 and collected in the casing 111 of the waste toner collection container 110 as shown in FIG. The Here, a part of the casing 111 of the waste toner collecting container 110 is constituted by the flexible film 112, and the heat receiving portion 31 of the cooling device is brought into contact with the portion constituted by the flexible film 112. Thereby, the waste toner in the heat receiving part 31, the flexible film 112, and the casing 111 can be adhered without interposing an air layer, and high heat receiving characteristics (heat exchange rate) can be obtained. Further, in this case, the portion constituted by the flexible film 112, that is, the portion to be cooled is positioned close to the inlet portion where the waste toner is carried from the toner conveyance path 120, so that the toner is frequently carried from the toner conveyance path 120. It is possible to effectively cool the waste toner to be used at an early stage.

  EXAMPLES Hereinafter, although an Example demonstrates this invention further more concretely, this invention is not limited to a following example.

Example 1 employs the configuration of the embodiment shown in FIG.
In the first embodiment, the heat receiving portion 31 is composed of a 30 mm × 330 mm × 14 mm aluminum block having a U-shaped flow path of φ6 inside. Three radiator corrugated aluminum corrugated radiators (thickness 20 mm) having a side of 120 mm are arranged in series in the heat radiating section 30, and the fan 34 has a square shaft having the same size as the radiator 33 and a side of 120 mm. A flow fan (flow rate 2.3 m / s) was used. The pump 32 has a deadline of 25 kPa, and a liquid contact portion in contact with the coolant is a resin-made piston type micro pump. The tank 35 is a polypropylene tank having a capacity of 1200 mL. Further, the metal pipe 37 is composed of an aluminum pipe, and here, a rubber tube of butyl rubber and EPDM mixed components is used instead of the resin tube 38. Further, as the cooling liquid, an antifreezing liquid of −30 ° C. antifreezing specification containing propylene glycol as a main component and containing a rust preventive agent was used. Further, the flow rate of the coolant supplied by the pump 32 was set to 0.5 L / min.

  With the above configuration, using a toner having a softening start temperature of 45 ° C. and performing 75-color double-sided printing per minute for 3 hours in an environment at a room temperature of 32 ° C. The maximum toner temperature was 42 ° C. for yellow, 42 ° C. for cyan, 43 ° C. for magenta, and 43 ° C. for black, and the toner temperature of any color was below the softening start temperature. As a result, a white streak image due to toner fixation and an abnormal image due to electrical noise, which are seen when the toner temperature is equal to or higher than the softening start temperature, did not occur.

In Example 2, the belt cleaning device was cooled with the same configuration as shown in FIG.
In this case, the heat receiving part 31 was comprised with the L-shaped aluminum block (depth 330mm) which has a copper pipe of (phi) 6 inside. A single aluminum corrugated radiator (thickness 20 mm) radiator 33 having a side of 120 mm is disposed in the heat radiating section 30, and a square axial fan having the same size as the radiator 33 and a side of 120 mm is provided in the fan 34. (Flow rate 2.3 m / s) was used. The pump 32 has a deadline of 25 kPa, and a liquid contact portion in contact with the coolant is a resin-made piston type micro pump. The tank 35 is a polypropylene tank having a capacity of 500 mL. Further, as the circulation path, the metal pipe 37 was not used, and a rubber tube of butyl rubber and EPDM mixed component was used. Further, as the cooling liquid, an antifreezing liquid of −30 ° C. antifreezing specification containing propylene glycol as a main component and containing a rust preventive agent was used. Further, the flow rate of the coolant supplied by the pump 32 was set to 1.0 L / min.

  With the above configuration, when a toner having a softening start temperature of 45 ° C. is used and 75-color double-sided printing is continuously performed for 2.5 hours in one minute in an environment at a room temperature of 32 ° C., the inside of the belt cleaning device The temperature rise of the waste toner was suppressed to 43 ° C. as an upper limit. In addition, there was no phenomenon such as toner sticking or toner recovery coil locking.

  As described above, in the present invention, the contact portion with the heat receiving portion of the object to be cooled is configured by the flexible film (flexible member), so that the heat receiving portion is flexible when it contacts the object to be cooled. Since the heat-resistant film is deformed along the shape of the contact surface of the heat receiving portion, the flexible film and the heat receiving portion can be brought into contact without interposing an air layer. Thus, according to the present invention, since the contact area between the two objects can be increased without interposing a heat conductive sheet between the object to be cooled and the heat receiving part, the heat receiving characteristic (heat exchange rate) can be increased. Improve dramatically. As a result, the object to be cooled can be effectively cooled, and an abnormality associated with a temperature rise can be avoided.

  Moreover, according to this invention, the contact area between a to-be-cooled body and a heat receiving part can be increased, without using grease. For this reason, it is not necessary to perform a repainting operation associated with the deterioration of the grease and the like, and the contact state between the cooled object and the heat receiving portion can be favorably maintained over a long period of time. Furthermore, by not using grease, it becomes possible to install the heat receiving portion even in places where it is difficult to use grease, and the degree of freedom in layout of the arrangement of devices and members in the image forming apparatus is increased.

  In addition, according to the present invention, the contact area between the object to be cooled and the heat receiving part can be increased without securing the flatness of the contact area with high accuracy, so that the cooling effect can be reduced at a low cost. Improvements can be realized.

  In the above-described embodiment, the case where an apparatus or member containing a developer is applied as an object to be cooled has been described as an example. However, the configuration of the present invention is not limited to this, and development is performed. The configuration of the present invention can also be applied to an object to be cooled that does not contain an agent. The image forming apparatus to which the present invention is applied is not limited to a four-color tandem type electrophotographic image forming apparatus in which four image forming units are arranged in the horizontal direction as shown in FIG. The present invention can also be applied to a monochrome image forming apparatus that uses only one color, a color image forming apparatus that uses five or more colors, a copying machine, a printer, a facsimile, or a complex machine thereof. It goes without saying that various modifications can be made without departing from the scope of the present invention.

4 Developing Device 9 Cooling Device 31 Heat-Receiving Part 50 Flexible Film 50a Outermost Surface Layer 50b Intermediate Layer (Good Heat Conducting Layer)
50c Outermost surface layer on heat receiving portion 55 Coil spring (pressing means)
59 Heat pipe

JP 2007-24985 A JP 2011-18008 A

Claims (10)

An object to be cooled, which is provided in the image forming apparatus main body, is in contact with the heat receiving portion of the cooling device, and is cooled by a cooling medium that circulates between the heat receiving portion and the heat radiating portion,
A body to be cooled , wherein a hole portion penetrating from an outer surface side to an inner surface side is formed in a contact portion of a casing that contacts the heat receiving portion , and the hole portion is covered with a flexible member. In the configuration in which the flexible member is disposed in a portion in contact with the developer,
The to-be-cooled body according to claim 1, wherein at least the outermost surface layer on the developer side of the flexible member is a developer-incompatible layer that does not dissolve the developer even when contacted with the developer. Said flexible member is composed of a plurality of layers, the cooling body according to claim 1 or 2 one layer of which is a good good heat conductive layer thermal conductivity than any other layers . The flexible member is composed of a plurality of layers, and the outermost surface layer on the heat receiving portion side is a resin material layer having higher impact resistance or wear resistance than any of the other layers. The to-be-cooled body according to any one of items 1 to 3. The to-be-cooled body according to any one of claims 1 to 4, wherein at least a part of a portion other than the contact portion that contacts the heat receiving portion is made of a material having a thermal conductivity better than that of the contact portion . A cooling device having a heat receiving portion that contacts a cooled object provided in the image forming apparatus main body, a heat radiating portion, and a circulation means for circulating a cooling medium between the heat receiving portion and the heat radiating portion. In the image forming apparatus,
An image forming apparatus, wherein the object to be cooled is the object to be cooled according to any one of claims 1 to 5.   The image forming apparatus according to claim 6, wherein the cooling device is a liquid cooling type cooling device that circulates a cooling liquid in a liquid state.   The image forming apparatus according to claim 6, wherein the cooling device is a cooling device having a heat pipe.   The image forming apparatus according to claim 6, wherein the cooling device is a vapor compression refrigeration device.   10. The device according to claim 6, further comprising a pressing unit that presses the heat receiving portion against the body to be cooled, wherein the reaction of the pressing force of the pressing unit can be applied to a predetermined portion of the body to be cooled. The image forming apparatus described.

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