JP2005164927A - Image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a cooling means having a high cooling effect in comparison with cooling by a fan, reducing noise and eliminating troubles such as toner scattering. <P>SOLUTION: In the image forming apparatus having a unit including toner and the cooling means for cooling the unit, the cooling means has configuration for taking away heat around a channel by making cooling liquid flow to the channel. The channel is installed at a part of a housing for supporting the unit, and a biasing means for biasing the channel to the unit set in an apparatus body is disposed in the housing. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to an image forming apparatus, and more particularly to an image forming apparatus having a developing device, a process cartridge, or a cleaner device that is cooled by a water-cooling type cooling unit.

  Generally, there are monochrome and color image forming apparatuses using an electrophotographic system, and there are a direct transfer system and an intermediate transfer system in terms of machine configuration. The direct transfer system is a system in which a toner image formed on a photoconductor as an image carrier is directly transferred to a transfer material held on a transfer body such as a transfer drum or a transfer belt. On the other hand, the intermediate transfer method is a method in which a toner image formed on a photoconductor as an image carrier is temporarily transferred onto an intermediate transfer member such as an intermediate transfer belt and then transferred to a transfer material in a secondary transfer portion. . In the recent intermediate transfer system, there is no need to hold a transfer material, it can be used for a wide variety of transfer materials, and has a merit that a paper path to the secondary transfer section can be simply configured, so it has attracted attention. . Hereinafter, an intermediate transfer type full-color image forming apparatus will be described as an example.

  FIG. 11 is a cross-sectional view of an intermediate transfer tandem color image forming apparatus. In the intermediate transfer tandem method, a plurality of image forming units 110Y to 110K are arranged side by side and toner images of each color are formed by parallel processing. Therefore, it is a configuration that is often used in high-speed machines as a configuration that can realize high productivity. Here, Y, M, C, and K represent yellow, magenta, cyan, and black, respectively.

  Each of the image forming units 110Y to 110K includes a charging device 111Y to 111K, an exposure device 112Y to 112K, a developing device 113Y to 113K, and a photoconductor 114Y to 114K. Further, the intermediate transfer belt 115 is stretched by a driving roller 116, a tension roller 117, and a secondary transfer inner roller 118, and rotates in the direction of the arrow in the drawing. As described above, the respective color toner images are sequentially transferred (primary transfer) on the intermediate transfer belt 115 by the primary transfer devices 119Y to 119K. In FIG. 11, the color order is Y, M, C, and K, but this is not a limitation.

  The color toner images thus obtained are collectively transferred onto the transfer material 121 conveyed from the feeding unit in the secondary transfer device 120. The secondary transfer device 120 has a secondary transfer outer roller 122, forms a nip by facing and pressurizing the secondary transfer inner roller 118, and electrostatically attracts the toner image onto the transfer material 121 Let

  After the secondary transfer, the transfer material 121 is delivered to the fixing device 123. The fixing device 123 forms a fixing nip with the fixing roller 124 and the pressure roller 125, and conveys the toner image on the transfer material 121 while heating and pressing. With the above configuration, a full color image fixed on the transfer material 121 is obtained.

  Here, in the above-described image forming apparatus, there is generally known an adverse effect caused by an increase in the ambient temperature in the image forming apparatus mainly due to radiation heat from the fixing device and other electrical components. In particular, the rise in the ambient temperature is severe for a unit containing toner, such as the developing device, and the melting, solidification, and alteration of the toner becomes a problem at about 45 ° C. or more.

  Conventionally, as a means for preventing an increase in ambient temperature, it is common to provide an air flow path in an image forming apparatus and cool or exhaust heat in the apparatus using a fan (for example, Patent Documents 1 to 5). reference).

JP2003-122181A JP 2003-005615 A JP 2003-005613 A Japanese Patent Laid-Open No. 08-022237 Japanese Patent Laid-Open No. 06-043788

  However, there are the following problems.

  When the ambient temperature in a substantially sealed container such as a developing device is cooled indirectly from the outside of the container like a fan, efficient cooling becomes difficult. In recent years, the on-board density of constituent units has become higher as image forming apparatuses for offices and consumers, and the trend toward smaller main body sizes are remarkable. For this reason, it is difficult to form an efficient air flow. In addition, due to the trend toward miniaturization, the distance between the heating element typified by the fixing device and the toner inclusion unit typified by the developing device is getting closer, and the ambient temperature is more likely to rise.

  In order to obtain a cooling effect in such a situation, it is conceivable to increase the fan output. However, fan cooling has a demerit of noise due to fan operation sound and wind noise, and this noise problem is highlighted. In the machine with remarkable downsizing as described above, it is often used as a desktop, and it is extremely important to reduce the noise of the fan.

  Another disadvantage of fan cooling is that pinpoint cooling is not good. As described above, when the distance between the heating element typified by the fixing device and the toner-containing unit typified by the developing device is short, the cooling of the fan cools the fixing device that is not the original cooling target. In general, it is desirable to keep the temperature of the fixing unit at a certain temperature regardless of whether it is during a job or during standby, and it is desired to avoid cooling the fixing unit itself.

  Further, as a problem specific to the unit around the toner, there is a problem of toner scattering in the apparatus. For example, the developing device or the like is almost sealed to prevent toner leakage, but there is a slight gap at the developing position facing the photosensitive drum. In addition, a small amount of toner that is not adsorbed on the photosensitive drum or the intermediate transfer belt at the time of image formation floats in the apparatus. In the case of fan cooling, the toner floating in the machine is scattered, which causes dirt in the machine and, in some cases, lens contamination of the exposure device, leading to a reduction in image quality.

  Therefore, an object of the present invention is to provide a cooling means that obtains a higher cooling effect than fan cooling, reduces noise, and has no problems such as toner scattering.

  In order to achieve the above object, as a typical configuration according to the present invention, in an image forming apparatus having a unit containing toner and a cooling unit for cooling the unit, the cooling unit allows the cooling liquid to flow. The flow path is configured to take heat around the flow path, and the flow path is installed in a part of a housing that supports the unit. And an urging means for urging the flow path.

  As described above, the present invention is configured such that the flow path is urged against the unit by the urging means, so that the unit and the flow path of the cooling means can be brought into close contact with each other, and a wide contact area can be ensured. Can do. Further, since the cooling means is provided not on the unit side but on the housing side of the image forming apparatus, the unit can be provided with high usability and maintainability, and the simplicity of the configuration of the cooling means and the cost associated therewith can be provided. An advantage can be obtained.

  As described above, the present invention is configured such that the flow path is urged against the unit by the urging means, so that the unit and the flow path of the cooling means can be brought into close contact with each other, and a wide contact area can be ensured. Can do. As a result, the efficiency of the exhaust heat action into the forced convection coolant having a large heat capacity and a high heat transfer effect can be enhanced, and a higher cooling effect can be obtained.

  In addition, since the cooling means is provided not on the unit side but on the housing side of the image forming apparatus, the unit can be provided with high usability and maintainability, and the simplicity of the structure of the cooling means and the cost associated therewith can be provided. An advantage can be obtained. In addition, with the abolition of the cooling fan, it is possible to achieve noise reduction of the image forming apparatus and prevention of toner scattering.

  Embodiments of the present invention will be described with reference to the drawings.

  FIG. 1 is a detailed view for explaining Example 1 of the present invention. FIG. 1 is a side view illustrating a developing device of an image forming apparatus and a supporting configuration of the developing device. Here, the image forming apparatus may be either monochrome or color. In the case of monochrome, the toner contained in the developing device (developing means) is black, and in the case of color, there are four colors of yellow, magenta, cyan and black. FIG. 1 describes any of these cases. 1A is a diagram illustrating a process of mounting the developing device to the image forming apparatus main body, and FIG. 1B is a diagram illustrating a state where the setting of the developing device to the image forming apparatus main body is completed.

(Case configuration of image forming apparatus)
The image forming apparatus main body 1 is mainly composed of a front side plate 2 and a rear side plate 3, and a plurality of stay members connecting the front side plate 2 and the rear side plate 3 to form a casing. The stay member 4 in FIG. 1 is one of the casings. Here, the stay member 4 serves not only to increase the strength of the housing of the image forming apparatus but also to hold the developing device 5 in an auxiliary manner. Here, the auxiliary holding means that the developing device 5 functions as a guide material when the developing device 5 is attached to and detached from the image forming apparatus main body 1 and is temporarily held.

  Accordingly, when the developing device 5 is set in the image forming apparatus main body 1, it is positioned and held by the regular positioning members 6a and 7a. The developing device 5 is provided with positioning holes 6b and 7b that fit into the positioning members 6a and 7a. Here, the positioning member 6 a is installed on the rear side plate 3, and the positioning member 7 a is installed on the inner cover member 8.

  In the configuration shown in FIG. 1, the developing device 5 is inserted into and removed from the image forming apparatus main body through an opening 9 provided in the front plate 2. The inner cover member 8 rotates around the hinge portion 10 and closes the opening 9 in order to prevent troubles such as accidental removal after the developing device 5 is set in the image forming apparatus. At this time, the positioning member 7a is simultaneously fitted into the positioning hole 7b, and the position of the developing device 5 is determined and held.

(Configuration of cooling means)
The cooling means of the developing device having the above configuration will be described. A pump 11 and a flow path 12 for circulating the cooling liquid w to the temperature raising unit in the image forming apparatus are provided in the image forming apparatus main body. Here, the position of the pump 11 is provided on the rear side plate 3 in FIG. Further, the image forming apparatus main body is provided with a tank (not shown) that stores a coolant.

  The flow path 12 exits from the pump 11 and is wound around any place in the image forming apparatus to form a cooling flow path 13 having a required flow area in each heat exchange unit, and then again to the image forming apparatus by the flow path 12. It leads to the provided heat dissipation part 14. The heat radiating portion 14 is provided, for example, on a front cover of the main body that can have a large heat radiating area. The coolant that has been cooled again by the heat radiation is circulated through the image forming apparatus by the pump 11 again. FIG. 1 focuses on the periphery of the developing device as one of the heat exchange units provided in the image forming apparatus.

  As shown in FIG. 1, the cooling flow path 13 is installed on the stay member 4 and forms a part of the stay member 4. Therefore, the cooling flow path 13 also serves as a guide for holding the developing device 5 when it is attached or detached (FIG. 1A). Here, the first embodiment shown in FIG. 1 includes means for pressing the surface of the cooling flow path 13 against the bottom surface of the developing device 5.

  Specifically, a pressure lever 15 and a pressure cam mechanism (not shown) that pressurizes the stay member 4 in the direction of arrow A in conjunction with the pressure lever 15 are provided on the inner cover member 8 (FIG. 1B). In particular, if the locking mechanism and the pressurizing mechanism when the inner cover member 8 is closed are linked to the pressurizing lever 15, the pressurizing mechanism becomes an urging means in the direction of arrow A, and the user or serviceman can develop the developing device. When 5 is set in the image forming apparatus main body, the surface of the cooling flow path 13 can inevitably be brought into pressure contact with the bottom surface of the developing device 5 manually. As a result, a contact area related to heat exchange can be ensured and cooling efficiency can be improved.

  Further, by installing the cooling channel 13 in the stay member 4, the cooling channel can be widened in the longitudinal direction, so that the cooling area can be increased. Further, since the main body side of the image forming apparatus has the cooling flow path 13, a structure that prevents the leakage of the cooling liquid accompanying the attachment and detachment of the developing device 5 is not particularly required. Therefore, high usability and maintainability of the developing device 5 can be ensured, and a relatively simple configuration can be obtained, so that superiority can be secured in terms of cost.

(Effect of water-cooled cooling means)
Here, the effect of the water cooling type cooling means will be described with reference to FIG. FIG. 2 schematically illustrates heat exchange between the developing device 5 and the cooling flow path 13. It is assumed that the atmospheric temperature in the developing device is T ₁ = 50 ° C. and the initial temperature of the cooling liquid is T ₂ = 25 ° C. At this time, if it is assumed that heat exchange is performed between the two in contact with each other and the heat equilibrium temperature T is reached, the amount of heat exchanged between the two is equal, and can be expressed by the following equation (1).

ρ ₁ c ₁ V ₁ (T ₁ −T) = ρ ₂ c ₂ V ₂ (T−T ₂ ) (1)

Assuming that the size of the developing device 5 is approximately the width w ₁ = 100 mm, the length L ₁ = 300 mm, and the height h ₁ = 70 mm, the volume V ₁ = 2.1 × 10 ⁻³ (m ³ ). On the other hand, assuming that the size of the cooling channel 13 is approximately the width w ₂ = 50 mm, the length L ₂ = 300 mm, and the height h ₂ = 10 mm, the volume V ₂ = 1.5 × 10 ⁻⁴ (m ³ ). ρ ₁ and c ₁ are the density and specific heat of air, ρ ₁ = 1.2 (kg / m ³ ), c ₁ = 0.24 (kcal / (kg · ° C.)), ρ ₂ and c ₂ are the density and specific heat of water, respectively. If ρ ₂ = 1.0 × 10 ³ (kg / m ³ ) and c ₁ = 1.0 (kcal / (kg · ° C.)) are used, T is about 25.1 ° C. from equation (1).

At this time, the amount of heat Q _{w taken} by the coolant before reaching thermal equilibrium is determined to be approximately 0.015 (J) from the right side of equation (1).

Here, while the developing device 5 is deprived of heat from the cooling flow path 13, it is always given heat by a heating element such as a fixing device in the image forming apparatus. If the heat flux flowing out from the developing device 5 to the cooling flow path 13 is q _out , q _out can be expressed by the following equation (2).

q _out = (T ₁ −T ₂ ) / (1 / h ₁ + d ₁ / λ ₁ + d ₂ / λ ₂ + 1 / h ₂ ) (2)

Here, h ₁ is the heat transfer coefficient of the contact portion of the casing of the developing device 5, λ ₁ is the same heat conductivity, and d ₁ is the same wall thickness. Similarly, h ₂ is the heat transfer coefficient to the coolant during forced convection, λ ₂ is the heat conductivity of the contact portion of the cooling flow path 13, and d ₂ is the wall thickness.

d ₁ = 2.5 mm, d ₂ = 2.0 mm, and at least the contact portion of the casing of the developing device 5 is formed of a resin (a resin having a relatively excellent heat transfer coefficient and heat conductivity), and the cooling channel Even if it is assumed that at least the contact portion is made of resin or rubber, q _out is approximately 5.0 × 10 ⁻² (W / m ³ ) from the equation (2). Of course, the contact portion may be formed of a metallic member. In this case, since the heat transfer coefficient and the heat conductivity are further improved, the value of q _out becomes larger and the cooling effect becomes higher.

Here, h ₂ is about 3.0 × 10 ³ (W / m ² · K), which is a relatively large value (by the way, it is about 66.4 (W / m ² · K) for air at 40 ° C). You can see the superiority of the water-cooled type with liquid. Since the contact area with the cooling channel 13 is approximately 1.5 × 10 ⁻³ (m ² ) from w ₂ × L _{2, the} heat quantity Q _out taken from the developing device 5 per unit time is approximately 7.5 × 10 ⁻⁴ ( J / s).

On the other hand, consider the case where the internal atmosphere temperature of the developing device 5 is lowered by dT (° C.) due to the cooling flow path 13. At this time, if the heat flux flowing into the developing device 5 from the heated atmosphere in the image forming apparatus is q _in , q _in can be expressed by the following equation (3).

q _in = dT / (1 / h ₁ + d ₁ / λ ₁ + 1 / h ₃ ) (3)

Here, h ₃ is a heat transfer rate to the air. From the right side of equation (1) and equation (2), dT generated during unit time is required to be approximately 24.99 ° C., and q _in is approximately 1.0 × 10 ⁻² (W / m ³ ) from equation (3). ).

Assuming that q _in flows from the side surface B of the developing device 5 as shown in FIG. 2, the heat exchange area is 2.1 × 10 ⁻² (m ² ) from h ₁ × L ₁ . Accordingly, the amount of heat Q _in given to the developing device 5 per unit time is determined to be approximately 2.1 × 10 ⁻⁴ (J / s).

From the above, the net amount of heat Q _r taken from the developing device 5 per unit time is calculated as 5.4 × 10 ⁻⁴ (J / s) from the difference between the two, and it can be seen that the cooling effect is sufficient. Incidentally, the time required to reach thermal equilibrium is determined to be about 30 (sec) from dT = Q _w / Q _r .

Further, since the temperature rise of the coolant accompanying heat exchange is very small, there is no need for immediate heat dissipation and the circulation flow rate of the pump can be relatively small. For example, if the average flow velocity in the cooling flow path 13 is 5 (mm / s), the flow is about Reynolds number Re = 50 and the flow rate of the pump is about 2.5 (cm ³ / s). The total amount of cooling water required for the entire image forming apparatus is considered to be about 1.5 to 2.0 liters in the case of a color machine. From the above, there is almost no sound of pump operation or sound of cooling liquid, and it has a great advantage over fan cooling from the viewpoint of noise.

As described above, efficient cooling is possible if a reliable contact area (heat exchange area) is ensured by a large heat capacity of the coolant (for example, water) and a large heat transfer coefficient in the case of forced convection. Further, in order to increase the cooling efficiency, h ₁ , λ ₁ and λ ₂ may be increased from the equation (2). In particular, when the order of d ₁ and d ₂ is actually relatively small as in the image forming apparatus, h ₁ is the most effective parameter. For example, it is more effective if the member of at least the portion of the casing of the developing device 5 that is in contact with the cooling flow path 13 is a metallic member having an excellent heat transfer coefficient. Of course, one of the means for enhancing the cooling effect is to use a member (for example, a metallic member) having excellent thermal conductivity (λ ₁ and λ ₂ ) as the contacting portion of the casing of the developing device 5 and the cooling channel 13. It is.

  In addition, the dimension and each value used by the above description are one of the reference values for demonstrating the predominance of a water cooling type cooling means, and are not limited to this.

(Relationship between cooling flow path and developing device)
FIG. 3 shows a sectional view of the developing device and the cooling channel. 3 corresponds to a cross-sectional view seen from the direction of arrow C in FIG. The developing device 5 generally includes screws 31a and 31b for circulating toner 30 supplied from a toner hopper (not shown) or the like. Here, the number of screws is not limited as long as it is at least two or more.

  The toner circulating in the developing device 5 by the screws 31a and 31b is charged with the developer by being simultaneously stirred with the developer and moves to the developing sleeve 32. Here, a uniform toner layer is formed on the developing sleeve 32 by the blade material 33. When the coolant is circulating inside the cooling flow path 13, the screws 31a and 31b are always operated. As described above, the stirring operation by the screws 31a and 31b in the casing of the developing device 5 to which the cooling flow path 13 is pressed is added, so that heat can be uniformly taken from the toner contained therein.

  The cooling liquid in this embodiment is cooling water containing an antifreeze and a preservative. Thereby, even if the temperature is low, such as in winter, the cooling liquid does not freeze and the cooling effect can be maintained. Further, it is possible to prevent rupture of the flow path due to freezing of the coolant. Furthermore, the decay of the coolant can be prevented. However, the cooling liquid may be other than cooling water as long as it has a large specific heat and a large cooling effect.

  With the configuration of the first embodiment described above, it is possible to effectively cool the atmospheric temperature inside the developing device included in the image forming apparatus. As a result, it is possible to prevent melting, solidification, and alteration of the toner, and to prevent troubles associated with image defects and image quality degradation. Further, the noise of the image forming apparatus can be reduced by eliminating the fan as the cooling means.

  FIG. 4 is a detailed view for explaining the second embodiment of the present invention. FIG. 4 is a side view for explaining the process cartridge of the image forming apparatus and the support structure of the process cartridge. Here, the process cartridge is a cartridge in which at least a charging unit, a photosensitive drum, and a developing device are integrally formed. The image forming apparatus may be either monochrome or color. In the case of monochrome, the toner included in the developing device is black, and in the case of color, there are four colors of yellow, magenta, cyan, and black. FIG. 4 illustrates any of these cases.

(Case configuration of image forming apparatus)
The main body 40 of the image forming apparatus is mainly composed of a front side plate 41 and a rear side plate 42, and a plurality of stay members connecting the front side plate 41 and the rear side plate 42, and forms a casing. The stay member 43 in FIG. 4 is one of them. Here, the stay member 43 serves not only to increase the strength of the casing of the image forming apparatus but also to hold the process cartridge 44 in an auxiliary manner. Here, the auxiliary holding means that the process cartridge 44 functions as a guide material when the process cartridge 44 is attached to or detached from the image forming apparatus main body 40 and is temporarily held. Accordingly, when the process cartridge 44 is set in the image forming apparatus main body 40, the process cartridge 44 is positioned and held by the regular positioning members 45a and 46a. The process cartridge 44 is provided with positioning holes 45b and 46b for fitting with the positioning members 45a and 46a. Here, the positioning member 45 a is installed on the rear plate 42, and the positioning member 46 a is installed on the inner cover member 47.

  In the configuration shown in FIG. 4, the process cartridge 44 is inserted into and removed from the image forming apparatus main body through an opening 48 provided in the front side plate 41. The inner cover member 47 rotates around the hinge portion 49 and closes the opening 48 in order to prevent troubles such as accidental removal after the process cartridge 44 is set in the image forming apparatus. At the same time, the positioning member 46a is fitted into the positioning hole 46b, and the position of the process cartridge 44 is determined and held.

(Configuration of cooling means)
The process cartridge cooling means having the above configuration will be described. A pump 401 and a flow path 402 for circulating the cooling liquid w to the temperature raising unit in the image forming apparatus are provided in the image forming apparatus main body. Here, the position of the pump 401 is provided on the rear side plate 42 in FIG. 4, but is not limited thereto. Further, the image forming apparatus main body is provided with a tank (not shown) that stores a coolant.

  The flow path 402 exits from the pump 401 and is wound around any place in the image forming apparatus to form a cooling flow path 403 having a required flow path area in each heat exchange unit, and then again to the image forming apparatus by the flow path 402. It leads to the provided heat dissipation part 404. The heat dissipating part 404 is provided, for example, on a front cover of the main body that can have a large heat dissipating area. The coolant that has been cooled again by heat radiation is circulated through the image forming apparatus by the pump 401 again. FIG. 4 focuses on the periphery of the developing portion of the process cartridge as one of the heat exchanging portions provided in the image forming apparatus.

  As shown in FIG. 4, the cooling flow path 403 is installed on the stay member 43 via the biasing means 405 and forms a part of the stay member 43. Furthermore, the cooling flow path 403 includes a protrusion 406 that functions as a guide portion, while the process cartridge 44 includes a groove 407 and a hole 408 that engage with the protrusion 406 in a part of the casing.

  By the urging means 405, when the process cartridge 44 is attached or detached, the cooling channel 403 contacts each other at the projection 406 and the groove 407, and the operability can be improved by engaging both. Thereafter, when the process cartridge 44 is set with respect to the main body of the image forming apparatus, the projection 406 engages with the hole 408 by the biasing means 405.

  Here, by making the depth of the hole 408 deeper than the height of the protrusion 406, the bottom surface of the process cartridge 44 (here, the bottom surface of the developing unit) and the surface of the cooling channel 403 can always be brought into pressure contact during engagement. . Accordingly, when the user or service person sets the process cartridge 44 in the image forming apparatus main body, the surface of the cooling flow path 403 can inevitably be brought into pressure contact with the bottom surface of the process cartridge 44 automatically. As a result, a contact area related to heat exchange can be ensured and cooling efficiency can be improved.

  Further, by installing the cooling channel 403 in the stay member 43, the cooling channel can be widened in the longitudinal direction, so that the cooling area can be increased. Further, since the main body side of the image forming apparatus has the cooling flow path 403, a mechanism for preventing leakage of the cooling liquid accompanying the attachment / detachment of the process cartridge 44 is not particularly required. Accordingly, high usability and maintainability of the process cartridge 44 are ensured, and a comparatively simple configuration is obtained, so that an advantage in terms of cost can be secured.

(Relationship between cooling flow path and process cartridge)
Next, a description will be given with reference to FIGS. FIG. 5 is a cross-sectional view when the process cartridge 44 is attached and detached, and corresponds to a view seen from the direction of arrow D in FIG. On the other hand, FIG. 6 is a cross-sectional view when the process cartridge 44 is set in the image forming apparatus main body, and similarly corresponds to a view seen from the direction of arrow D in FIG. The engagement relationship between the protrusion 406 and the groove 407 or the hole 408 by the urging means is as already described with reference to FIG. Further, since the configuration of the developing unit is almost the same as that in FIG. 3, detailed description thereof is omitted here.

  Here, in the casing of the process cartridge 44, the developing portion 50 to which the cooling flow path 403 is pressed is projected from the other surface constituting the same surface of the casing as shown in FIGS. In this embodiment, an arcuate convex shape that matches the circulating and stirring screws 51a and 51b of the developing device is employed. As a result, the contact area is increased and the surface area for heat exchange is increased, so that the cooling effect is enhanced. Further, the contact portion 52 with the cooling channel 403 is formed of a member that can be elastically deformed.

  In the present embodiment, as the elastically deformable member, for example, formation of the contact surface of the cooling flow path 403 by a vinyl resin material or rubber is cited, and the case where the contact surface itself is deformed is described. As a result, as shown in FIG. 6, the cooling flow path 403 pressed by the biasing means 405 can be brought into close contact with the arcuate convex shape, and the cooling effect is further enhanced.

  In addition to this embodiment, for example, a metal leaf spring member or the like as an elastically deformable member may be provided on the contact surface of the cooling flow path 403 to form several contact portions. In this case, the contact area is slightly reduced, but a similar effect can be expected due to excellent thermal conductivity and contact properties.

  Further, since the screws 51a and 51b are provided as described above, the heat of the contained toner can be taken away uniformly, and the cooling efficiency is excellent. The screws 51a and 51b always operate when the coolant in the cooling channel 403 is circulating.

  The cooling liquid in this embodiment is cooling water containing an antifreeze and a preservative. Thereby, even if the temperature is low, such as in winter, the cooling liquid does not freeze and the cooling effect can be maintained. Further, it is possible to prevent rupture of the flow path due to freezing of the coolant. Furthermore, the decay of the coolant can be prevented. However, the cooling liquid may be other than cooling water as long as it has a large specific heat and a large cooling effect.

  With the configuration of the second embodiment described above, it is possible to effectively cool the atmospheric temperature inside the process cartridge (particularly the developing device) of the image forming apparatus. As a result, it is possible to prevent melting, solidification, and alteration of the toner, and to prevent troubles associated with image defects and image quality degradation. Further, the noise of the image forming apparatus can be reduced by eliminating the fan as the cooling means.

(Image forming device)
FIG. 7 is a cross-sectional view illustrating a cleaner device (cleaning unit) of the image forming apparatus. In the image forming units 70Y to 70K for the respective colors Y, M, C, and K, the toner images are sequentially transferred onto the intermediate transfer belt 71 sequentially. Here, the image forming units 70Y to 70K are composed of a photosensitive drum, a charging device, an exposure device, a developing device, and the like (refer to the description in FIG. 11 for details).

  The full-color toner image primarily transferred onto the intermediate transfer belt 71 is collectively transferred (secondary transfer) onto the transfer material conveyed by the feeding means in the secondary transfer portion 72. In this secondary transfer, excess toner that cannot be transferred onto the transfer material and remains on the intermediate transfer belt 71 is collected by the cleaner device 74 in preparation for the next image formation. In the cleaner device, the residual toner 73 on the intermediate transfer belt 71 is scraped off by the cleaning blade 75 and is transported by the transport screw 76 as waste toner.

  Thereafter, the waste toner is collected by a waste toner bottle or the like included in the image forming apparatus, and is subjected to processing such as periodic disposal. Although the cleaner device for cleaning the intermediate transfer belt has been particularly described here, a configuration other than the intermediate transfer belt may be used as long as it is an intermediate transfer member. Of course, other cleaner devices may be used as long as the image forming device has a cleaner device.

  FIG. 8 is a detailed view for explaining the third embodiment of the present invention. FIG. 8 is a side view for explaining the cleaner device of the image forming apparatus and the support structure of the cleaner device. In the third embodiment, the intermediate transfer belt cleaner described with reference to FIG. 7 will be described as an example.

  A main body 80 of the image forming apparatus is mainly composed of a front plate 81 and a rear plate 82, and a plurality of stay members connecting the front plate 81 and the rear plate 82, and forms a casing. The stay member 83 in FIG. 8 is one of them. Here, the stay member 83 serves not only to increase the strength of the casing of the image forming apparatus but also to hold the cleaner device 84 in an auxiliary manner. Here, the auxiliary holding means that the cleaner device 84 functions as a guide material when the cleaner device 84 is attached to and detached from the image forming apparatus main body 80 and is temporarily held.

  Accordingly, when the cleaner device 84 is set in the image forming apparatus main body 80, it is positioned and held by the regular positioning member 85a. The cleaner device 84 is provided with a positioning hole 85b for fitting with the positioning member 85a. Here, it is assumed that the positioning member 85a is installed on the rear plate 82. In the configuration shown in FIG. 8, the cleaner device 84 is inserted into and removed from the image forming apparatus main body through an opening 86 provided in the front plate 81.

(Configuration of cooling means)
The cooling means of the cleaner device having the above configuration will be described. A pump 88 and a flow path 89 are provided in the image forming apparatus main body to circulate the cooling liquid w to the temperature raising unit in the image forming apparatus. Here, the position of the pump 88 is provided on the rear side plate 82 in FIG. Further, the image forming apparatus main body includes a tank (not shown) for storing the cooling liquid.

  The flow path 89 exits from the pump 88 and is wound around any place in the image forming apparatus to form a cooling flow path 800 having a required flow area in each heat exchange unit, and then again to the image forming apparatus by the flow path 89. It leads to the provided heat dissipation part 801. The heat dissipating part 801 is provided, for example, on a front cover of the main body that has a large heat dissipating area. The coolant that has been cooled again by heat radiation is circulated through the image forming apparatus by the pump 88 again. FIG. 8 focuses on the periphery of the cleaner device as one of the heat exchange units provided in the image forming apparatus.

  As shown in FIG. 8, the cooling flow path 800 is installed on the stay member 83 via the biasing means 802 and forms part of the stay member 83. Furthermore, the cooling flow path 800 includes a protrusion 803 that functions as a guide portion, while the cleaner device 84 includes a groove 804 and a hole 805 that engage with the protrusion 803 in a part of the casing.

  The urging means 802 allows the cooling channel 800 to contact with each other at the projection 803 and the groove 804 when the cleaner device 84 is attached / detached, thereby improving the operability. After that, when the cleaner 84 is set on the image forming apparatus main body, the projection 803 is engaged with the hole 805 by the biasing means 802.

  Here, by making the depth of the hole 805 deeper than the height of the protrusion 803, the bottom surface of the cleaner device 84 and the surface of the cooling flow path 800 can always be brought into pressure contact during engagement. Thus, when the user or service person sets the cleaner device 84 in the image forming apparatus main body, the surface of the cooling flow path 800 can inevitably be automatically pressed against the bottom surface of the cleaner device 84. As a result, a contact area related to heat exchange can be ensured and cooling efficiency can be improved.

  In addition, by installing the cooling channel 800 in the stay member 83, the cooling channel can be widened in the longitudinal direction, so that the cooling area can be increased. Furthermore, since the main body side of the image forming apparatus has the cooling flow path 800, a mechanism for preventing a leakage of the cooling liquid accompanying the attachment / detachment of the cleaner device 84 becomes unnecessary. Therefore, high usability and maintainability of the cleaner device 84 are ensured, and a relatively simple configuration is obtained, so that an advantage in terms of cost can be secured.

(Relationship between cooling flow path and cleaner device)
Next, description will be made with reference to FIGS. FIG. 9 is a cross-sectional view when the cleaner device 84 is attached and detached, and corresponds to a view seen from the direction of arrow E in FIG. On the other hand, FIG. 10 is a cross-sectional view when the cleaner device 84 is set in the image forming apparatus main body, and similarly corresponds to a view seen from the direction of arrow E in FIG. The engagement relationship between the projection 803 and the groove 804 or the hole 805 by the biasing means 802 is as already described with reference to FIG. Further, since the configuration of the cleaner device is almost the same as that of FIG. 7, detailed description thereof is omitted here.

  Here, of the casing of the cleaner device 84, the press-contact portion 91 that is press-contacted with the cooling flow path 800 protrudes from the other surface constituting the same surface of the casing as shown in FIGS. In the present embodiment, an arcuate convex shape matching the waste toner conveying screw 90 having the cleaner device 84 is employed. Thereby, the surface area where heat exchange is performed is increased, and the cooling effect is enhanced. Furthermore, the contact portion 801 of the cooling channel 800 is formed of a member that can be elastically deformed. In the present embodiment, as an elastically deformable member, for example, formation of the contact surface of the cooling flow path 800 using a vinyl resin material or rubber is cited, and the case where the contact surface itself is deformed is described. As a result, as shown in FIG. 10, the cooling flow path 800 pressed by the biasing means 802 can be brought into close contact with the arcuate convex shape, and the cooling effect is further enhanced. In addition to this embodiment, for example, a metal leaf spring member or the like as an elastically deformable member may be provided on the contact surface of the cooling flow path 800 to form several contact portions. In this case, the contact area is slightly reduced, but a similar effect can be expected due to excellent thermal conductivity and contact properties.

  Further, as described above, the agitation operation of the waste toner conveying screw 90 can be used to remove heat uniformly from the waste toner contained therein, resulting in a configuration with excellent cooling efficiency. The screw 90 always operates when the coolant in the cooling flow path 800 is circulating.

  Here, it is assumed that the contact portion of the casing of the cleaner device 84 and the cooling channel 800 that are pressed against each other by the urging means is formed of a resin or a metallic member. In the case of a resin member, there is an advantage in terms of moldability and cost, and a sufficient cooling effect can be obtained by selecting a resin material having a relatively excellent heat transfer coefficient and heat conductivity. Further, in the case of a metallic member, a higher cooling effect can be obtained due to the excellent heat transfer coefficient and heat conductivity.

  The cooling liquid in this embodiment is cooling water containing an antifreeze and a preservative. Thereby, even if the temperature is low, such as in winter, the cooling liquid does not freeze and the cooling effect can be maintained. Further, it is possible to prevent rupture of the flow path due to freezing of the coolant. Furthermore, the decay of the coolant can be prevented. However, the cooling liquid may be other than cooling water as long as it has a large specific heat and a large cooling effect.

  With the configuration of the third embodiment described above, it is possible to effectively cool the atmospheric temperature inside the cleaner device included in the image forming apparatus. As a result, waste toner can be prevented from melting and solidifying, and troubles such as locking and breakage of the waste toner conveying screw can be prevented. Further, the noise of the image forming apparatus can be reduced by eliminating the fan as the cooling means.

  The present invention can be applied to an image forming apparatus having a developing device, a process cartridge, or a cleaner device.

FIG. 3 is a detailed diagram for explaining the developing device of the image forming apparatus and the supporting structure of the developing device (Example 1). FIG. 3 is a schematic diagram for heat exchange between a developing device and a cooling channel (Example 1). Sectional drawing of a developing device and a cooling channel (Example 1). FIG. 7 is a detailed diagram for explaining a process cartridge of the image forming apparatus and a support configuration of the process cartridge (second embodiment). Sectional drawing at the time of attachment or detachment of a process cartridge (Example 2). Sectional drawing at the time of setting a process cartridge to the image forming apparatus main body (Example 2). Sectional drawing explaining the cleaner apparatus of an image forming apparatus (Example 3). FIG. 7 is a detailed diagram for explaining a cleaner device of an image forming apparatus and a support configuration of the cleaner device (Example 3). Sectional drawing at the time of attachment and detachment of the cleaner device (Example 3). Sectional drawing when the cleaner device is set on the image forming apparatus main body (Example 3). Sectional drawing of a color image forming apparatus of an intermediate transfer tandem system (conventional example).

Explanation of symbols

w ... coolant,
DESCRIPTION OF SYMBOLS 1 ... Image forming apparatus main body, 2 ... Front side plate, 3 ... Rear side plate, 4 ... Stay member,
5: Developing device, 6a: Positioning member, 6b: Positioning hole, 7a: Positioning member,
7 ... Positioning hole, 8 ... Inner cover member, 9 ... Opening part, 10 ... Hinge part,
11 ... pump, 12 ... flow path, 13 ... cooling flow path, 14 ... heat dissipation part, 15 ... lever,
30 ... toner, 31a ... screw, 31b ... screw, 32 ... developing sleeve,
33… Blade material,
40 ... Image forming apparatus main body, 41 ... Front side plate, 42 ... Rear side plate, 43 ... Stay member,
44 ... Process cartridge, 45a ... Positioning member, 45b ... Positioning hole,
46a ... positioning member, 46b ... positioning hole, 47 ... inner cover member, 48 ... opening,
49 ... Hinge part, 50 ... Developing part, 51a ... Screw, 51b ... Screw,
70 ... Image forming section, 71 ... Sequential intermediate transfer belt, 72 ... Secondary transfer section, 73 ... Residual toner,
74 ... Cleaner device, 75 ... Cleaning blade, 76 ... Conveying screw,
80 ... Image forming apparatus main body, 81 ... Front side plate, 82 ... Rear side plate, 83 ... Stay member,
84 ... Cleaner device, 85a ... Positioning member, 85b ... Positioning hole, 86 ... Opening,
88 ... pump, 89 ... flow path, 90 ... waste toner conveying screw, 91 ... pressure contact part,
401 ... pump, 402 ... flow path, 403 ... cooling flow path, 404 ... heat dissipation part, 405 ... biasing means,
406 ... projection, 407 ... groove, 408 ... hole, 800 ... cooling flow path, 801 ... heat dissipation part, 802 ... biasing means,
803 ... projection, 804 ... groove, 805 ... hole

Claims (12)

In an image forming apparatus having a unit containing toner, and a cooling means for cooling the unit,
The cooling means is configured to remove heat around the flow path by flowing a coolant through the flow path,
The flow path is installed in a part of a housing that supports the unit,
The image forming apparatus according to claim 1, wherein the casing is provided with a biasing unit that biases the flow path with respect to a unit set in the apparatus main body. The image forming apparatus according to claim 1.
The cooling means is
A tank for storing the coolant,
A pump for circulating the coolant;
A heat dissipating part for dissipating the heat taken away by the coolant,
An image forming apparatus comprising: a flow path through which the cooling liquid flows. The image forming apparatus according to claim 1, wherein:
An image forming apparatus, wherein a portion of the casing of the unit that is pressed against the flow path by the biasing unit is formed of a resin or a metallic member. The image forming apparatus according to any one of claims 1 to 3,
An image forming apparatus, wherein a portion of the flow path that is pressed against the casing of the unit by the biasing unit is formed of a resin or a metallic member. 5. The image forming apparatus according to claim 1, wherein:
The image forming apparatus according to claim 1, wherein a portion of the flow path that is pressed against the unit by the biasing unit is formed of a member that can be elastically deformed. The image forming apparatus according to any one of claims 1 to 5,
The image forming apparatus according to claim 1, wherein a part of the casing of the unit, to which the flow path is pressed by the urging means, protrudes from other parts constituting the same surface of the casing. The image forming apparatus according to any one of claims 1 to 6,
The unit is a unit that is detachably supported with respect to the image forming apparatus main body,
An image forming apparatus, wherein a guide portion that guides the unit when the unit is attached and detached is formed in the housing, and a groove and a hole that engage with the guide portion are formed in the unit. The image forming apparatus according to claim 1,
The unit includes a screw member for stirring or conveying the toner inside.
The image forming apparatus, wherein the screw member performs a stirring or conveying operation of the toner when the cooling liquid is circulating in the flow path. The image forming apparatus according to claim 8.
The image forming apparatus according to claim 1, wherein the unit is a developing unit including toner of an arbitrary color in order to develop the latent image formed on the image carrier. The image forming apparatus according to claim 9.
The image forming apparatus, wherein the developing means is a part of a process cartridge integrated with the image carrier. The image forming apparatus according to claim 8.
The image forming apparatus according to claim 1, wherein the unit is a cleaning unit that collects excess toner generated in the image forming process. The image forming apparatus according to claim 1,
The image forming apparatus, wherein the cooling liquid contains an antifreeze and a preservative.

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