Developing device and image forming apparatus

Abstract

To provide a developing apparatus and an image forming apparatus that can be formed smaller compared with cases where a large-sized heat sink is provided.SOLUTION: A developing apparatus 95 has a housing 300 as an enclosure. A transportation path for transporting a developer is formed within the housing 300. A cooling unit 200 is arranged in part of the transportation path for the developer. The cooling unit 200 is a pipe-shaped member composed of aluminum or aluminum alloy with a higher heat transfer coefficient than resin which constitutes the housing 300. The cooling unit 200 covers the inner surface of the transportation path for the developer at the area where the cooling unit is arranged, and is formed to extend in a circumferential direction of the transportation path.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to a developing device and an image forming apparatus. [Background technology]

[0002] Patent Document 1 discloses a developing device and an image forming apparatus equipped with the same, which includes a developing container that contains developer, an agitator that transports the developer while stirring it, a developing sleeve that rotates by adsorbing the developer transported by the agitator onto its surface, and a developing blade that is arranged with a uniform, small gap from the surface of the developing sleeve and that regulates the amount of developer adsorbed on the surface of the developing sleeve to be thin and uniform. The developing device and image forming apparatus equipped with the same have at least one cooling means that contacts the agitator inside the developing container and absorbs heat from the agitator, a cooling means that contacts the developing sleeve inside the developing container and absorbs heat from the developing sleeve, and a cooling means that contacts the developing blade inside the developing container and absorbs heat from the developing blade, and the heat dissipation portion of the cooling means is arranged outside the developing container, outside the transport area of ​​the transfer material when the image forming apparatus is viewed from above. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2003-114577 Summary of the Invention [Problem to be solved by the invention]

[0004] SUMMARY OF THE INVENTION An object of the present invention is to provide a developing device and an image forming apparatus that can be made smaller than when a large heat sink is provided. [Means for solving the problem]

[0005] The developing device according to the first aspect has a hollow transport path for transporting developer, and a portion of the surface constituting the transport path is formed by a cooling section made of a material with a higher thermal conductivity than other portions.

[0006] In a developing device according to a second aspect, the transport path is covered with a housing, and the housing has an opening at a portion located outside the cooling unit, through which the cooling unit faces the outside of the housing.

[0007] In a developing device according to a third aspect, the housing is composed of an elongated main body housing and an end housing located at one end of the main body housing, and the opening is provided in the end housing.

[0008] The developing device according to a fourth aspect includes a seal member between the cooling section and the end-side housing at a contact portion.

[0009] In the developing device according to a fifth aspect, the opening is provided at a position where the developing device is exposed to an air flow generated inside the image forming device when the developing device is installed in the image forming device.

[0010] In a developing device according to a sixth aspect, the opening is provided on a surface of the transport path that is parallel to the direction in which the developer is transported.

[0011] In the developing device according to a seventh aspect, the cooling section is formed in a pipe shape extending in the circumferential direction of the transport path.

[0012] An image forming apparatus according to an eighth aspect includes the developing device according to any one of the first to seventh aspects, and an air blower that blows air toward the cooling section.

[0013] The image forming apparatus according to the ninth aspect includes an intake section that draws air into the image forming apparatus and an exhaust section that exhausts the air, and when the developing device is installed in the image forming apparatus, the cooling section is disposed on the intake section side. [Effects of the Invention]

[0014] According to the first aspect, it is possible to provide a developing device that can be made smaller than when a large heat sink is provided.

[0015] According to the second aspect, the cooling effect can be improved compared to when the cooling portion does not face the outside of the housing.

[0016] According to the third aspect, compared to when an opening is provided in the elongated main body housing, the opening can be opened while maintaining the strength of the housing.

[0017] According to the fourth aspect, compared to a configuration in which a seal member is disposed only between the main body housing and the cooling portion, it is possible to prevent developer from leaking from the gap.

[0018] According to the fifth aspect, the cooling effect of the cooling section facing the opening can be improved compared to when the air flow does not come into contact with the cooling section.

[0019] According to the sixth aspect, the cooling effect can be improved compared to when the opening is provided on a surface other than the surface parallel to the developer transport direction of the second transport path.

[0020] According to the seventh aspect, the cooling effect can be improved compared to when the cooling portion is provided only on a part of the circumferential direction.

[0021] According to the eighth aspect, the cooling effect of the cooling unit can be improved compared to when the air from the blower does not come into contact with the cooling unit.

[0022] According to the ninth aspect, the cooling effect of the cooling section can be improved compared to when the cooling section is disposed on the exhaust section side. [Brief explanation of the drawings]

[0023] [Figure 1] 1 is a side view illustrating a configuration of an image forming apparatus according to an embodiment of the present invention. [Figure 2] 1 is a perspective view showing an external appearance of a developing device according to an embodiment of the present invention; [Figure 3] FIG. 2 is a perspective view showing an end portion of a developing device including a support portion according to an embodiment of the present invention. [Figure 4] 1 is a perspective view including a vertical cross section of a developing device according to an embodiment of the present invention; [Figure 5] FIG. 2 is a vertical cross-sectional view showing a developing device according to the embodiment of the present invention. [Figure 6] FIG. 2 is a horizontal cross-sectional view showing the developing device according to the embodiment of the present invention. [Figure 7] FIG. 4 is a vertical cross-sectional view showing a second transport path and a transport member from which a cooling unit has been removed according to the embodiment of the present invention. [Figure 8] 10 is a vertical cross-sectional view showing a second transport path and a transport member to which a cooling unit according to an embodiment of the present invention is attached. FIG. [Figure 9] FIG. 2 is a rear view showing an end portion of the developing device according to the embodiment of the present invention. [Figure 10] FIG. 10 is an external perspective view showing an example of another cooling unit according to an embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0024] The present embodiment will be described below with reference to the drawings. Note that the same components and processes are given the same reference numerals throughout the drawings, and redundant description will be omitted.

[0025] Figure 1 is a side view showing the configuration of an image forming apparatus, Figure 2 is an external perspective view showing a developing device, Figure 3 is an external perspective view showing the end of the developing device including a support part, Figure 4 is an external perspective view including a vertical section of the developing device, Figure 5 is a vertical cross-sectional view showing the developing device, Figure 6 is a horizontal cross-sectional view showing the developing device, Figure 7 is a vertical cross-sectional view showing a second conveying path and conveying member with the cooling part removed, Figure 8 is a vertical cross-sectional view showing the second conveying path and conveying member with the cooling part attached, Figure 9 is a rear view showing the end of the developing device, and Figure 10 is an external perspective view showing an example of another cooling part.

[0026] Next, an embodiment of the present invention will be described with reference to the drawings. Fig. 1 shows an image forming apparatus 10 used in the embodiment of the present invention. The image forming apparatus 10 has an image forming apparatus main body 12, which contains an image forming section 14, a transfer device 16, a fixing device 18, and a paper feeder 20. A transport path 22 for transporting a recording medium such as paper is also formed within the image forming apparatus main body 12. 1 is defined as the positive side of the X-axis direction, the upward direction is defined as the positive side of the Y-axis direction, and the forward direction is defined as the positive side of the Z-axis direction, and the same directions are used in other drawings as well.

[0027] The image forming section 14 employs an electrophotographic system to form an image on a recording medium. The image forming section 14 has, for example, a plurality of, for example, four, image forming units 24. The four image forming units 24 form toner images of different colors, for example, yellow, magenta, cyan, and black.

[0028] The image forming unit 24 has a photosensitive drum 26. The photosensitive drum 26 is an example of an image carrier, and rotates while holding a toner image to be transferred to a recording medium on its outer circumferential surface. The image forming unit 24 also has a charging device 28 that charges the photosensitive drum 26, a developing device 95 that develops the charged latent image with toner, and a cleaning device 32 that cleans the photosensitive drum 26 after transfer. The image forming unit 24 also has an optical writing device 48 that forms a latent image on the charged photosensitive drum 26.

[0029] The transfer device 16 has an intermediate transfer belt 34. Toner images are primarily transferred from the photosensitive drums 26 onto the intermediate transfer belt 34 by a primary transfer member 36, and the primarily transferred toner images are secondarily transferred onto a recording medium by a secondary transfer member 38.

[0030] The intermediate transfer belt 34 is supported so as to be rotatable by a plurality of support members 40. Also, a backup member 42 is provided opposite the secondary transfer member 38.

[0031] The fixing device 18 fixes the toner image transferred onto the recording medium to the recording medium using, for example, heat and pressure.

[0032] The paper feeder 20 has a storage section 44 that stores stacked recording media, and a delivery member 46 that delivers the recording media stored in the storage section 44 toward the transport path 22 .

[0033] The transport path 22 transports the recording medium from the paper feed device 20 to between the secondary transfer member 38 and the backup member 42, then transports the recording medium further to the fixing device 18, and further transports the recording medium so that it is discharged outside the image forming device main body 12.

[0034] In the image forming device 10 configured as described above, the toner images formed on the outer peripheral surfaces of the photosensitive drums 26 are primarily transferred to the intermediate transfer belt 34, the toner images primarily transferred to the intermediate transfer belt 34 are secondarily transferred to a recording medium, and the toner images secondarily transferred to the recording medium are fixed to the recording medium by the fixing device 18.

[0035] The image forming apparatus 10 according to the present embodiment uses a developing device 95 that develops an electrostatic latent image formed on the electrostatic latent image holder of the photosensitive drum 26. Such developing device 95, for example, contains a two-component developer (hereinafter simply referred to as developer) made of a magnetic carrier and a resin-based toner in a housing 300 having a development opening facing the electrostatic latent image holder (photosensitive drum 26), and a developing roll 190 serving as a developer holder is disposed at a location facing the development opening of the housing 300. An auger is disposed on the back side of the developing roll 190 as a transport member that agitates and transports the developer inside a transport path in the housing 300 while transporting it to the developing roll.

[0036] As shown in FIGS. 1 to 9 , the developing device 95 according to the present embodiment has a housing 300 serving as a casing that is open at a portion facing the photosensitive drum 26 and that contains a developer. A developing roll 190 serving as a developing member that is a developer carrier is disposed facing the opening of the housing 300. Inside the housing 300, which serves as an example of a casing, there are provided, at a portion adjacent to the developing roll 190, a first transport path 100 that contains the developer so that it can be supplied to the developing roll 190, and a second transport path 150 that is disposed adjacent to the first transport path 100 and that contains the developer so that it can be supplied to the first transport path 100. As shown in FIG. 4 , the first transport path 100 and the second transport path 150 are disposed adjacent to each other in the direction of gravity, and the second transport path 150 is formed to be located below the first transport path 100.

[0037] Here, the first transport path 100 and the second transport path 150 are separated from each other by a partition wall and communicate with each other at both axial ends thereof. Specifically, a communication hole 110 (see FIG. 5) is formed at the front end, and a communication hole (not shown) is formed at the rear end. Within the housing 300, the developer circulates in the order of the second transport path 150, the front communication hole 110, the first transport path 100, and the rear communication hole.

[0038] The developing device 95 includes a conveying member that applies a conveying force to circulate the developer within the housing 300. Specifically, the developing device 95 includes a supply auger 120 disposed in the first conveying path 100 and an admix auger 170 disposed in the second conveying path 150. The supply auger 120 has a main winding portion 180, which is a helical blade, formed on the outer periphery of its shaft. By rotating about its shaft, the supply auger 120 conveys the developer in a predetermined axial direction (e.g., the negative side of the Z-axis direction in FIG. 5 ) while supplying it to the developing roll 190. The admix auger 170 has a main winding portion 180, which is a helical blade, formed on the outer periphery of its shaft. By rotating about its shaft, the admix auger 170 conveys the developer in the opposite direction to the supply auger 120 (e.g., the positive side of the Z-axis direction in FIG. 5 ) while stirring the developer. The supply auger 120 is an example of a first conveying member, and the admix auger 170 is an example of a second conveying member.

[0039] The rotation of the supply auger 120 and the admix auger 170 causes the developer G to circulate through the above-mentioned path. The second transport path 150 extends forward of the communicating hole 110, and in this section, a reverse wound portion 185, which is a spiral blade, is formed on the outer periphery of the shaft of the admix auger 170. The reverse wound portion 185 applies a transport force to the developer in the opposite direction to that of the main wound portion 180, thereby promoting the lifting of the developer that has been transported to the communicating hole 110 by the main wound portion toward the communicating hole 110.

[0040] On the other hand, the first transport path 100 extends forward beyond the communication hole 110 and forms a part of a developer discharge path 186 that discharges excess developer. The developer discharge path 186 is composed of a portion that extends in the positive Z direction forward beyond the communication hole 110 in the first transport path 100 and beyond the reverse winding portion 185 of the admix auger 170, and a portion that extends downward from the end of the portion and vertically penetrates the second transport path 150. The formation of the developer discharge path 186 allows a so-called trickle system to gradually discharge deteriorated developer to the outside of the housing 300. The portion of the developer discharge path 186 extending in the Z direction is provided with a portion where a reverse winding portion 185 is formed. The reverse winding portion 185 applies a transport force to the developer in the opposite direction to that of the main winding portion 180 of the supply auger 120.

[0041] In this embodiment, a third transport path 195 in which a counter auger 196, which is a third transport member, is disposed is formed in the housing 300. The counter auger 196 rotates around its axis to return the developer not consumed by the developing roll 190 to the second transport path 150.

[0042] The housing 300 is formed by joining a main body housing 320 and an end-side housing 340. The main body housing 320 is formed with the first transport path 100 and the second transport path 150 up to a portion slightly before the communication hole 110. The end-side housing 340 is formed with the remaining portions of the first transport path 100 and the second transport path 150. The main body housing 320 and the end-side housing 340 are fixed to each other by screwing fastening members 342, 344, 346 into the main body housing 320 (housing) from the end-side housing 340 side in an abutting state with a seal member 156 sandwiched between their ends.

[0043] 3 to 6, in this embodiment, the cooling unit 200 is disposed at a position adjacent to the communication hole 110 of the second conveying path 150. The cooling unit 200 is disposed on the front side of the communication hole 110 in the second conveying path 150. The cooling unit 200 is a pipe-shaped member made of aluminum or an aluminum alloy, which has a higher thermal conductivity than the resin that is the material of the housing 300. The cooling unit 200 covers the inner surface of the second conveying path 150 at the portion where it is disposed, and is formed to extend in the circumferential direction of the second conveying path 150. Specifically, the cooling unit 200 covers the periphery of the reverse winding portion 185 of the admix auger 170.

[0044] The cooling unit 200 is fixed to the casing 300 by being sandwiched between the main body side housing 320 and the end side housing 340 .

[0045] A specific description will be given below. A recessed portion 152 is formed in the main body side housing 320 at a portion where the second transport path 150 is formed. The recessed portion 152 has an inner diameter wider than the transport path 150, and extends to the end of the end side housing 340 in the main body side housing 320. The end of the recessed portion 152 opposite the end side housing 340 side forms an abutment surface facing the end side housing 340 side. A part of the cooling unit 200 on the negative side in the Z direction is fitted into the recessed portion 152 with the cooling unit 200 abutting against the abutment surface of the recessed portion 152. Another part of the cooling unit 200 is fitted inside the end-side housing 340. A seal member 154 is interposed between the end-side housing 340 and the end of the cooling unit 200 opposite to the main body-side housing 320. A fastening load is applied to the seal member 154 by the fastening members 342, 344, and 346 described above. That is, as described above, the cooling unit 200 is sandwiched between the main body-side housing 320 and the end-side housing 340 by the fastening load of the fastening members 342, 344, and 346, and is fixed to the casing 300.

[0046] 8, the pipe inner diameter of cooling section 200 and the pipe inner diameter of second conveying path 150 are formed to be the same, and the inner surfaces of both are formed to be continuous without any step. However, the pipe inner diameter of cooling section 200 may be formed to be smaller than the pipe inner diameter of second conveying path 150. This allows the developer conveyed by reverse winding section 185 to be smoothly conveyed in the direction of communication hole 110.

[0047] Furthermore, an opening 360 through which the cooling unit 200 faces the outside of the housing is formed in a portion of the housing 300 located outside the cooling unit 200. The opening 360 is formed in the shape of a rectangular window that penetrates from the inside to the outside of the housing, and is configured to allow the cooling unit 200 to come into contact with the air outside the housing 300.

[0048] In this embodiment, the opening 360 is formed in two places: an upper opening 362 facing diagonally upward from the casing 300 (housing) as shown in Fig. 2, and a lower opening 364 facing downward from the casing 300 (housing) as shown in the rear view of Fig. 9. The opening 360 is provided on a surface parallel to the developer transport direction (positive side in the Z-axis direction) of the second transport path 150. In this embodiment, the upper opening 362 and the lower opening 364 are formed in the end-side housing 340, and the above-mentioned seal member 156 is located on the edge of each opening on the main-body-side housing 320 side.

[0049] 2, the image forming apparatus 10 includes an intake unit 420 that draws air into the image forming apparatus 10 and an exhaust unit 430 that exhausts the air. When the image forming apparatus 10 is viewed from the side shown in FIG. 1, the intake unit 420 is an opening in the right-side plate, and when the image forming apparatus 10 is viewed from the side shown in FIG. 1, the exhaust unit 430 is an opening in the rear-side plate. When the developing device 95 is installed in the image forming apparatus 90, the cooling unit 200 is disposed on the intake unit 420 side, not the exhaust unit 430 side. The intake unit 420 includes a blower 400 that blows air toward the cooling unit 200. Therefore, the opening 360 is positioned so that it can come into contact with the airflow generated inside the image forming apparatus 10 when the developing device 95 is installed in the image forming apparatus 10. Here, intake section 420 is a portion that opens into the plate on the right side when image forming apparatus 10 is viewed from the side shown in Fig. 1, and exhaust section 430 is a portion that opens into the plate on the far side when viewed from the side shown in Fig. 1. The number of intake section 420 and exhaust section 430 is not limited to one, and each developing device 95 may be provided with one. Also, a duct that connects intake section 420 to opening 360 may be provided to make it easier to send the air taken in from intake section 420 to cooling section 200.

[0050] (action) Next, the operation of the above-described embodiment will be described. In the developing device 95, when the supply auger 120 and the admix auger 170 rotate, the developer circulates within the housing 300 in the order of the second conveying path 150, the front communicating hole 110, the first conveying path 100, and the back communicating hole.

[0051] In the embodiment described above, the transport direction of the developer in the second transport path 150 (from the negative side in the Z-axis direction to the positive side in the Z-axis direction in FIG. 5) is changed to the transport direction of the developer in the first transport path 100 (from the positive side in the Z-axis direction to the negative side in the Z-axis direction in FIG. 5), and pressure needs to be applied to the developer near the communication hole 110 of the second transport path 150 in order to lift and move the developer upward into the first transport path 100. At that time, the frictional force between the developer particles increases, generating frictional heat, which increases the temperature of the developer, etc.

[0052] Furthermore, in order to save space in the image forming device, if the conveying members such as the auger shaft are rotated at high speed without increasing the diameter and remaining small, heat will be generated in the bearings and drive system, and the heat generated in the area where the developer accumulates near the communicating hole will tend to become significant.

[0053] In this embodiment, the cooling unit 200 is disposed adjacent to the communication hole 110. The cooling unit 200 has a higher thermal conductivity than the housing 300.

[0054] According to this embodiment, it is possible to provide a developing device 95 that can be formed smaller than when a large heat sink is provided. Here, the cooling section 200 is provided on a part of the inner surface of the second transport path 150. As a result, the cooling section 200 can directly absorb heat from the heated developer and further dissipate the absorbed heat to the surroundings rather than the housing, thereby suppressing the concentration of heat and suppressing the temperature rise of the developer, etc.

[0055] According to this embodiment, the cooling effect can be improved compared to when the cooling unit 200 does not face the outside of the housing 300.

[0056] According to the present embodiment, compared to when the opening 360 is provided in the elongated main body housing 320, the opening 360 can be opened while maintaining the strength of the housing 300. That is, by forming the end side housing (support portion) 340 shorter than the elongated main body housing 320, it becomes possible to open the opening 360 while maintaining the strength and rigidity of the housing.

[0057] According to this embodiment, compared to a case where a seal member is disposed only between the main body side housing 320 and the cooling unit 200, leakage of developer from the gap can be suppressed.

[0058] According to this embodiment, the cooling effect of the cooling unit 200 can be improved compared to when the cooling unit 200 facing the opening 360 is not exposed to the air flow.

[0059] According to this embodiment, the cooling effect can be improved compared to when the opening 360 is provided on a surface other than the surface parallel to the developer transport direction of the second transport path 150.

[0060] According to this embodiment, the cooling effect can be improved compared to when the cooling section 200 is provided only on a part of the circumferential direction.

[0061] According to this embodiment, the cooling effect of the cooling unit 200 can be improved compared to when the air from the blower 400 does not come into contact with the cooling unit 200.

[0062] According to the present embodiment, the cooling effect of cooling unit 200 can be enhanced compared to when cooling unit 200 is disposed on the exhaust unit 430 side. That is, as shown in FIG. 2 , by providing intake unit 420, cooled fresh air from outside image forming apparatus 10 is taken into image forming apparatus 10 through intake unit 420 by blower device 400. The airflow is then directed directly at cooling unit 200. As a result, the air whose temperature has increased as a result of absorbing heat emitted from the surface of cooling unit 200 can be discharged to the outside of image forming apparatus 10 through exhaust unit 430. In addition, an airflow as shown in FIG. 2 can be generated inside image forming apparatus 10, thereby enhancing the cooling effect of cooling unit 200 without increasing the air temperature inside image forming apparatus 10.

[0063] 5 and 6, in the above-described embodiment, the cooling section 200 is provided from a position adjacent to the communication hole 110 to a position corresponding to the developer discharge path 186. This makes it possible to suppress a rise in temperature near the developer discharge path 186, to prevent malfunction of the developer discharge path 186 through which the developer is discharged, and to maintain the function of discharging excess developer.

[0064] Furthermore, in the above-described embodiment, as shown in Figures 3, 5, and 6, when the support part 340 is fixed to the end of the housing 300 with fastening members (342, 344, 346), the cooling part 200 is sandwiched between the support part 340 and the housing 300, and the support part 340 is fixed to the housing 300 with the fastening members (342, 344, 346). As a result, compared to a structure in which the cooling unit 200 is fixed to the housing 300 of the developing device 95 using a dedicated fastening mechanism or other attachment, the cooling unit 200 can be fixed to the developing device 95 without requiring a separate special fastening mechanism or the like for fixing the cooling unit 200. Furthermore, the structure of the developing device 95 can be simplified without being made complicated.

[0065] Furthermore, although the cooling section 200 according to this embodiment has an overall cylindrical pipe shape and does not have any openings or notches, the shape is not particularly limited to this. Specifically, for example, as shown in FIG. 10 , the cooling section 200 may have a notch 210 cut out at a position corresponding to the communication hole 110. When the notch 210 is provided, it is desirable to arrange the communication hole 110 between one side 211 and the other side 212 of the notch 210 that face each other. Note that, although the notch 210 is cut out at an end of the cooling section 200 in this embodiment, the position and shape of the notch 210 are not particularly limited to a notch at the end, and the cooling section 200 may be formed in the shape of a hole that opens further inward.

[0066] As shown in Figure 10, if the cooling section 200 has a notch 210 corresponding to the communicating hole 110, the cooling section 200 can be positioned close to the periphery of the communicating hole 110, and the temperature rise around the communicating hole 110 can be efficiently suppressed.

[0067] In addition, in this embodiment, the first transport path 100 and the second transport path 150 are arranged adjacent to each other above and below in the direction of gravity, in a so-called vertical arrangement, but the present invention is not particularly limited to such a vertical arrangement. Specifically, for example, even if the plurality of transport paths are arranged horizontally in the direction of gravity rather than vertically in the direction of gravity as described above, the same action and effect can be achieved by providing the cooling unit 200 as described above in a developing device that rotates at high speed to increase efficiency and is expected to cause a temperature rise in the developer due to frictional force, and this is applicable.

[0068] The present invention is not limited to the above-described embodiment, and various modifications, changes, and improvements are possible without departing from the spirit of the present invention. For example, the above-described embodiment may be configured by appropriately combining multiple embodiments. [Explanation of symbols]

[0069] 10 image forming apparatus, 12 image forming apparatus main body, 14 image forming section, 16 transfer device, 18 fixing device, 20 paper feeding device, 22 transport path, 24 image forming unit, 26 photosensitive drum, 28 charging device, 30 developing device, 32 cleaning device, 34 intermediate transfer belt, 36 primary transfer member, 38 secondary transfer member, 40 support member, 42 backup member, 44 storage section, 46 delivery member, 48 optical writing device, 95 developing device, 100 first transport path, 110 communication hole, 120 first transport member (supply auger), 150 second transport path, 152 recessed portion, 153 stepped portion, 154 sealing member, 156 sealing member, 170 second transport member (admix auger), 180 main winding portion, 185 reverse winding portion, 186 Developer discharge path, 190 developing member (developing roll), 195 third transport path, 196 third transport member (counter auger), 200 cooling section, 210 notch, 211 one side, 212 other side, 300 casing (housing), 320 main body side housing, 340 end side housing (support section), 342, 344, 346 fastening member, 360 opening, 362 upper opening, 364 lower opening, 400 blower device, 410 air flow, 420 intake section, 430 exhaust section

Claims

1. A hollow transport path for transporting a developer is provided, A part of the surface constituting the transport path is formed as a cooling portion made of a material having a higher thermal conductivity than other parts, The transport path is covered with a housing, an opening portion through which the cooling portion faces the outside of the housing is provided in a portion of the housing located outside the cooling portion; The housing is composed of an elongated main body housing and an end housing located at one end of the main body housing, The opening is provided in the end housing of the developing device.

2. The developing device according to claim 1 , further comprising a seal member between the cooling portion and the end housing at a portion where the cooling portion and the end housing are in contact with each other.

3. 3. The developing device according to claim 1, wherein the opening is provided at a position where the developing device is exposed to an air flow generated inside the image forming device when the developing device is installed in the image forming device.

4. 4. The developing device according to claim 1, wherein the opening is provided on a surface of the transport path parallel to a transport direction of the developer.

5. 5. The developing device according to claim 1, wherein the cooling section is formed in a pipe shape extending in a circumferential direction of the transport path.

6. A developing device according to any one of claims 1 to 5, an image forming apparatus comprising: a blower that blows air toward the cooling unit;

7. An image forming apparatus includes an intake section that draws air into the image forming apparatus and an exhaust section that exhausts the air, The image forming apparatus according to claim 6 , wherein the cooling unit is disposed on the side of the intake unit when the developing device is installed in the image forming apparatus.

Images