JP2012177786A - Cooling mechanism and image forming apparatus incorporating cooling mechanism - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a cooling mechanism capable of performing optimal cooling by changing an amount of supplied cooling air according to an operation mode.SOLUTION: The cooling mechanism comprises: a cooling fan 16 for cooling a first object 18 to be cooled; a cooling air duct 17 provided between the first object 18 to be cooled and the cooling fan 16, having a shutter, and used for guiding cooling air from the cooling fan 16 to the first object 18 to be cooled; a brush-less motor 21 with vanes 23 attached thereto; and a driving air duct 24 disposed from the vicinity of the vanes 23 to the vicinity of the cooling air duct 17. During the stop of the brush-less motor 21, cooling air from the cooling fan 16 cools the first object 18 to be cooled. During the rotation of the brush-less motor 21, driving air generated by the rotation of the vanes 23 is supplied to the vicinity of the cooling duct 17 via the driving air duct 24, thereby actuating the shutter. A part of the cooling air is also supplied to a second object 19 to be cooled. Consequently, the second object 19 to be cooled is cooled together with the first object 18 to be cooled.

Description

  The present invention relates to a cooling mechanism that cools an object to be cooled using a cooling fan, and an image forming apparatus equipped with the cooling mechanism.

  Conventionally, in an image forming apparatus, a cooling mechanism has been proposed in which a cooling fan is attached to a substrate and an object to be cooled is cooled by cooling air generated by the rotation of the cooling fan (see, for example, Patent Document 1).

  Further, as a conventional image forming apparatus, one equipped with a cooling mechanism as shown in FIG. 16 is known. 16A is a side view showing the main part of the image forming apparatus, and FIG. 16B is a sectional view taken along the line SA-SA in FIG. The image forming apparatus 1 is provided with outer plates 2 and 2 on the right and left sides, and main body inner plates 3 and 3 are disposed between the outer plates 2 and 2.

  The cooling fans 4 and 5 are attached to the left inner body plate 3 of the main body inner plates 3 and 3. The cooling fans 4 and 5 have fan main bodies 4A and 5A therein, and the fan main bodies 4A and 5A are rotationally driven by a motor (not shown). Brushless motors 6, 7, and 8 are attached to the left main body inner plate 3.

  A cooling object 9 is disposed between the main body inner plates 3 and 3, and a through hole 3 </ b> A is formed in the left main body inner plate 3 at a position facing the cooling object 9. The cooling fan 5 is disposed at a position matching the through hole 3A. The left end surface of the cooling fan 5 (the left end surface in FIG. 16B) is open, and the outside air intake 2 (actually a slit-like intake) 2A is provided in the left outer plate 2 in accordance with the opening. Is formed.

  When the fan main body 5A of the cooling fan 5 rotates as indicated by an arrow A1, outside air is sucked as indicated by an arrow B1 through the outside air intake port 2A. The sucked outside air flows through the through hole 3A of the main body inner side plate 3 around the object 9 to be cooled as indicated by an arrow C1 to cool the object 9 to be cooled.

  However, in the above conventional technique, the cooling air from the cooling fan is merely sent around the object to be cooled, and sufficient cooling air cannot be supplied to the object to be cooled.

  For example, in an image forming apparatus, there are a plurality of objects to be cooled, and the amount of cooling air supplied by these objects to be cooled differs depending on the operation mode (printing operation and standby). It is common. On the other hand, in the conventional technology, there is a problem that the amount of cooling air supplied to each cooling object is always the same and optimal cooling is not performed.

  An object of the present invention is to provide a cooling mechanism that can perform optimal cooling by changing the supply amount of cooling air according to an operation mode, and an image forming apparatus equipped with the cooling mechanism.

  In order to solve the above-mentioned problem, an invention according to claim 1 is provided between a cooling fan that cools a first cooling object, the first cooling object and the cooling fan, and a shutter. And a cooling air duct that guides the cooling air from the cooling fan to the first object to be cooled, a motor to which blades having a fan function are attached, and from the vicinity of the blades to the vicinity of the cooling air duct. When the motor is stopped, the cooling air from the cooling fan is sent to the first object to be cooled through the cooling air duct to cool the first object to be cooled. During the rotation of the motor, a driving wind generated by the rotation of the blades is supplied to the vicinity of the cooling air duct via the driving air duct, and the shutter is operated, and a part of the cooling air flowing through the cooling air duct Is the second It is also sent to the retirement object, also characterized by cooling said second cooling object together with the first object to be cooled.

  According to the above configuration, when the motor is stopped, the cooling air from the cooling fan is sent to the first object to be cooled, and the first object to be cooled is cooled. When the motor rotates, driving air is generated by rotation of blades attached to the motor, and this driving air is sent to the vicinity of the cooling air duct via the driving air duct to operate the shutter of the cooling air duct. Thereby, a part of cooling air from the cooling fan is also supplied to the second cooling object, and the second cooling object is cooled together with the first cooling object. As described above, in the above configuration, the supply amount of the cooling air to the first cooling object and the second cooling object is changed according to the operation modes of when the motor is stopped and when the motor is rotating. Optimal cooling can be performed.

  According to a second aspect of the present invention, there is provided an image forming apparatus for transferring an image on a photosensitive member to a sheet fed by a conveying device and fixing the image after transfer by a fixing device. A cooling fan that cools an object, a cooling air that is provided between the first cooling object and the cooling fan, has a shutter, and guides the cooling air from the cooling fan to the first cooling object A duct, a brushless motor to which blades having a fan function are attached, and a driving air duct disposed from the vicinity of the blades to the vicinity of the cooling air duct, and when the brushless motor is stopped, Cooling air from the cooling fan is sent to the first object to be cooled via the cooling air duct to cool the first object to be cooled, and the brushless motor is rotating. During the operation, the driving air generated by the rotation of the blades is supplied to the vicinity of the cooling air duct through the driving air duct, the shutter is operated, and a part of the cooling air flowing through the cooling air duct is the second air. It has a cooling mechanism which is also supplied to a cooling object and cools the second cooling object together with the first cooling object.

  According to the above configuration, when the cooling mechanism is in a standby state (when the brushless motor is not rotating), the cooling air from the cooling fan is sent to the first cooling object that needs to be cooled in the standby state. The object to be cooled is cooled. During the printing operation (when the brushless motor rotates), driving air is generated by the rotation of the blades attached to the brushless motor, and this driving air is supplied to the vicinity of the cooling air duct via the driving air duct, and the shutter of the cooling air duct. Operates. Thereby, a part of cooling air from the cooling fan is also supplied to the second cooling object, and the second cooling object is cooled together with the first cooling object. As described above, in the image forming apparatus having the above-described configuration, the supply amount of the cooling air to the first cooling object and the second cooling object is changed according to the operation modes of standby and printing operation. Thus, optimal cooling can be performed.

  According to a third aspect of the present invention, in the second aspect, the brushless motor is a motor that drives the photosensitive member.

  According to a fourth aspect of the present invention, in the second aspect, the brushless motor is a motor that drives the fixing device.

  According to a fifth aspect of the present invention, in the second aspect, the brushless motor is a motor that drives the transport device.

  According to a sixth aspect of the present invention, in any one of the second to fifth aspects, the cooling fan is arranged so that the cooling air blows out perpendicularly or parallel to the side plate of the image forming apparatus main body. It is characterized by that.

  According to a seventh aspect of the present invention, in any one of the second to sixth aspects, the second cooling object is a fixing unit.

  The invention described in claim 8 is the cooling air duct according to claim 2, wherein the cooling air duct includes a cylindrical inner duct having a through hole, and a cylinder having a through hole and provided in close contact with the outer peripheral surface of the inner duct. When the through hole of the inner duct and the through hole of the outer duct match, a part of the cooling air is supplied to the second cooling object.

  According to a ninth aspect of the present invention, in the second aspect, a fin is attached to the inner peripheral surface of the inner duct in the vicinity of the through hole, and a fin is attached to the outer peripheral surface of the outer duct in the vicinity of the through hole. It is characterized by being.

  A tenth aspect of the present invention is the method according to the second, eighth or ninth aspect, wherein the inner duct and the outer duct are arranged in a circumferential direction between the outer peripheral surface of the inner duct and the inner peripheral surface of the outer duct. A spring that urges them in opposite directions is interposed.

  According to the present invention, it is possible to realize a cooling mechanism capable of performing optimal cooling and an image forming apparatus equipped with the cooling mechanism by changing the supply amount of the cooling air according to the operation mode.

1 shows an image forming apparatus equipped with a cooling mechanism according to Embodiment 1 in a standby state, where (a) is a side view showing the main part thereof, and (b) is an SB-SB line of (a). FIG. 1 shows an image forming apparatus equipped with a cooling mechanism according to a first embodiment, and shows a state during a printing operation, wherein (a) is a side view showing an essential part thereof, and (b) is an SC-SC of (a). It is sectional drawing along a line. In Example 1, it is the figure which showed typically a mode that the cooling air from a cooling fan was sent to a 1st cooling target object and a 2nd cooling target object by a cooling wind duct. The inner duct of the cooling wind duct which has a shutter mechanism is shown, (a) is the sectional drawing, (b) is a side view. The outer duct of the cooling air duct which has a shutter mechanism is shown, (a) is the sectional drawing, (b) is a side view. The state where the shutter of the cooling air duct is closed is shown, (a) is a sectional view, and (b) is a side view. The state which the shutter of the cooling air duct opened is shown, (a) is the sectional view, (b) is a side view. The cooling air duct with which the fin was attached to the inner peripheral surface of an inner duct and the outer peripheral surface of an outer duct is shown, (a) is the sectional drawing, (b) is a side view. 2 shows an image forming apparatus mounted with a cooling mechanism according to a second embodiment, in a standby state, (a) is a side view showing the main part, and (b) is an SD-SD line of (a). FIG. 2 shows an image forming apparatus equipped with a cooling mechanism according to a second embodiment, and shows a state during a printing operation, where (a) is a side view showing an essential part thereof, and (b) is an SE-SE of (a). It is sectional drawing along a line. In Example 2, it is the figure which showed typically a mode that the cooling air from a cooling fan was sent to a 1st cooling target object and a 2nd cooling target object by a cooling wind duct. The inner duct by Example 3 is shown, (a) is the sectional drawing, (b) is a side view. The outer duct by Example 3 is shown, (a) is the sectional drawing, (b) is a side view. The cooling mechanism at the time of standby by Example 3 is shown, (a) is the sectional drawing, (b) is a side view. The cooling mechanism at the time of the printing operation by Example 3 is shown, (a) is the sectional drawing, (b) is a side view. 1 shows an image forming apparatus equipped with a cooling mechanism according to the prior art, in which (a) is a side view showing the main part thereof, and (b) is a sectional view taken along line SA-SA in (a).

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

Example 1
1A and 1B show an image forming apparatus equipped with a cooling mechanism in a standby state. FIG. 1A is a side view showing the main part of the image forming apparatus, and FIG. 1B is a line SB-SB in FIG. FIG. FIG. 2 shows an image forming apparatus equipped with a cooling mechanism in a printing operation. (A) is a side view showing the main part, and (b) is an SC- of (a). It is sectional drawing along SC line. 1 and 2, the photoconductor, the transfer device that transfers the image on the photoconductor to the paper, the fixing device that fixes the image after transfer, the transport device that transports the paper, and the like are omitted.

  The image forming apparatus 10 is provided with an outer plate 11 on the left side and an outer plate 12 on the right side, and main body inner plates 13 and 14 are arranged between the outer plates 11 and 12, respectively.

  The cooling fans 15 and 16 are arranged in the horizontal direction on the left inner body plate 13 of the main body inner plates 13 and 14, respectively. Among them, the cooling fan 15 is directly attached to the main body inner plate 13, but the cooling fan 16 is attached to the main body inner plate 13 via the cooling air duct 17.

  In other words, the cooling fan 15 includes a square cylindrical fan casing 15A and a fan main body 15B rotatably disposed inside the fan casing 15A. The fan main body 15B is driven to rotate by a motor (not shown). Is done. The fan casing 15 </ b> A is directly attached to the main body inner plate 13.

  On the other hand, the cooling fan 16 has a square cylindrical fan casing 16A and a fan main body 16B rotatably disposed inside the fan casing 16A, and the fan main body 16B is rotationally driven by a motor (not shown). . Then, one end of the cooling air duct 17 (the left end in FIG. 1B) is fixed to the fan casing 16A, and the other end of the cooling air duct 17 (the right end in FIG. 1B). Part) is attached to the main body inner side plate 13.

  A first cooling object 18 is disposed between the main body inner plates 13, 14, and a through hole 13 </ b> A is formed in the main body inner plate 13 at a position facing the first cooling object 18. The cooling air duct 17 is disposed at a position where the other side end matches the through hole 13A. An opening 16C is formed on one side (left side in FIG. 1B) of the fan casing 16A of the cooling fan 16, and the outside plate 11 (in practice, the outside air intake port (actually) is aligned with the opening 16C. A slit-shaped intake) 11A is formed.

  The main body inner plate 13 is provided with a second cooling object 19 on the side of the cooling fan 16, a brushless motor 20 below the cooling fan 15, and a brushless motor 21 below the cooling fan 16. The brushless motors 22 are respectively mounted in the horizontal direction below the second cooling object 19. The second cooling object 19 is a fixing unit.

  In this embodiment, the brushless motor 21 is provided with blades 23 having a fan function. A driving air duct 24 is disposed from the vicinity of the blades 23 to the vicinity of the cooling air duct 17. The drive air duct 24 has a U-shaped cross section, and both end portions thereof are in close contact with the main body inner plate 13. The brushless motor 21 is a motor that drives the photosensitive member, a motor that drives the fixing device, or a motor that drives the conveying device.

  Here, the structure of the cooling air duct 17 is demonstrated in detail using FIG.4 and FIG.5. 4 shows an inner duct 171 constituting the cooling air duct 17, wherein (a) is a sectional view thereof and (b) is a side view. FIG. 5 shows an outer duct 172 constituting the cooling air duct 17, wherein (a) is a sectional view thereof and (b) is a side view.

  The inner duct 171 has a cylindrical shape, and three through holes 171A, 171B, and 171C are provided in a part thereof. The through holes 171A, 171B, and 171C are each formed in a rectangular shape, and all are directed in the same direction. That is, the central axes of the through holes 171A, 171B, and 171C are oriented in the horizontal direction in FIG. The inner duct 171 has one end face (left end face in FIG. 4B) on the fan casing 16A of the cooling fan 16, and the other end face (right end face in FIG. 4B) on the main body inner plate 13. Each is fixed.

  The outer duct 172 also has a cylindrical shape, and three through holes 172A, 172B, and 172C are provided in a part thereof. The inner diameter of the outer duct 172 is slightly larger than the outer diameter of the inner duct 171, and when the inner duct 171 is fitted to the outer duct 172, the outer duct 172 is rotatable around the inner duct 171 ( (See FIG. 7). The through holes 172A, 172B, and 172C are each formed in a rectangular shape, and all are directed in the same direction. That is, the central axis of each of the through holes 171A, 171B, and 171C is directed to the lower right in FIG.

  The outer duct 172 is provided with a driving wind receiving portion 172D having a substantially triangular cross section below the through hole 172C. The driving wind receiving portion 172D is arranged so as to be biased toward the one end face side of the outer duct 172, and a gap S (see FIGS. 6 and 7) is formed between the driving wind receiving portion 172D and the main body inner side plate 13. It has become.

  Next, the operation of the image forming apparatus equipped with the cooling mechanism in this embodiment will be described.

  In the image forming apparatus, the brushless motor 21 and the like stop rotating when the printing operation is not performed. However, since the first cooling object 18 needs to be cooled even during the standby, FIG. ), The cooling fan 16 rotates in the direction of the arrow A2, so that the outside air passes through the outside air intake port 11A as shown by the arrow B2, that is, perpendicular to the outer plate 11 and the main body inner plate 13. Inhaled in the direction. The sucked outside air is sent to the first cooling object 18 through the cooling air duct 17 and the through hole 13A of the main body inner plate 13, and flows around the first cooling object 18 as indicated by an arrow C2. Thus, the first cooling object 18 is cooled.

  In this case, as shown in FIG. 6, the cooling air duct 17 has the driving air receiving portion 172 </ b> D positioned at the lowest position due to its own weight, and thereby the through holes 171 </ b> A, 171 </ b> B, 171 </ b> C of the inner duct 171, The cooling air flowing inside the cooling air duct 17 does not coincide with the through holes 172A, 172B, 172C of the outer duct 172, but reaches the through holes 171A, 171B, 171C as indicated by the arrow D1, but the cooling air duct There will be no outflow from 17 to the outside. For this reason, almost all the cooling air from the cooling fan 16 can be sent to the first cooling object 18.

  Since the brushless motor 21 and the like rotate during the printing operation, a driving wind is generated when the blades 23 attached to the brushless motor 21 rotate in the direction of the arrow A4, and this driving wind is generated as shown in FIG. Then, the air flows in the direction of the arrow E through the driving air duct 24 and reaches the vicinity of the cooling air duct 17 to operate the shutter of the cooling air duct 17. That is, as shown in FIG. 7, the driving air supplied as shown by the arrow E through the driving air duct 24 hits the driving air receiving portion 172 </ b> D of the outer duct 172 in the cooling air duct 17, and the wind pressure of this driving air To rotate the outer duct 172 in the direction of arrow F. The inner duct 171 is fixed and does not rotate.

  When the outer duct 172 rotates in the direction of arrow F, each of the through holes 171A, 171B, 171C of the inner duct 171 and each of the through holes 172A, 172B, 172C of the outer duct 172 coincide with each other. A part of the cooling air flows out from the cooling air duct 17 through the through holes 171A, 171B, 171C and the through holes 172A, 172B, 172C as indicated by an arrow D2. As a result, the cooling air in the cooling air duct 17 flows as indicated by an arrow D3 in FIG. 2A, and the second cooling object 19 is also cooled. At this time, the remaining cooling air flowing through the cooling air duct 17 is sent to the first cooling object 18 through the through-hole 13A of the main body inner plate 13, and the first cooling object 18 is cooled. Of course.

  FIG. 3 is a diagram schematically illustrating how the cooling air from the cooling fan 16 is sent to the first cooling object 18 and the second cooling object 19 by the cooling air duct 17. That is, a part of the cooling air from the cooling fan 16 is sent to the second cooling object 19 as indicated by the arrow D3, and the remaining part is sent to the first cooling object 18 as indicated by the arrow C2. .

  According to the present embodiment, a part of the cooling air from the cooling fan 16 is also supplied to the second cooling object 19 and the remaining part is supplied to the first cooling object 18. The supply amount of the cooling air can be changed according to the operation modes of the forming apparatus during standby and during printing operation, and optimal cooling can be performed.

  Further, since the gap S is formed between the driving wind receiving portion 172D of the outer duct 172 and the main body inner side plate 13, the driving wind receiving portion 172D does not hit the main body inner side plate 13, and the outer duct 172 is smoothly moved. Can be rotated.

  FIG. 8 shows a modification of the cooling air duct 17. In this modification, fins 171D and 172E are attached to the inner peripheral surface of the inner duct 171 and the outer peripheral surface of the outer duct 172, respectively. The fins 171D are attached between the through hole 171A and the through hole 171B, between the through hole 171B and the through hole 171C, and below the through hole 171C. The fins 172E are attached between the through hole 172A and the through hole 172B, between the through hole 172B and the through hole 172C, and below the through hole 172C.

  Then, the driving wind supplied through the driving wind duct 24 as shown by the arrow E hits the driving wind receiving portion 172D of the outer duct 172 in the cooling wind duct 17, and the wind pressure of this driving wind causes the outer duct 172 to move to the arrow F. Rotate in the direction.

  When the outer duct 172 rotates in the direction of arrow F, each of the through holes 171A, 171B, 171C of the inner duct 171 and each of the through holes 172A, 172B, 172C of the outer duct 172 coincide with each other. A part of the cooling air flows out from the cooling air duct 17 through the through holes 171A, 171B, 171C and the through holes 172A, 172B, 172C as indicated by an arrow D2, and the second cooling object 19 is allowed to flow out. Cooling.

  According to this modification, the cooling air is rectified by the fins 171D and 172E when passing through the through holes 171A, 171B and 171C and the through holes 172A, 172B and 172C, and the directivity of the cooling air is improved. The cooling air can be efficiently applied to the second cooling object 19.

Example 2
9 and 10 show the second embodiment. 9A and 9B show an image forming apparatus equipped with a cooling mechanism in a standby state. FIG. 9A is a side view showing an essential part thereof, and FIG. 9B is an SD-SD line in FIG. FIG. FIG. 10 shows an image forming apparatus equipped with a cooling mechanism during a printing operation. FIG. 10A is a side view showing the main part of the image forming apparatus, and FIG. It is sectional drawing along SE line.

  In this embodiment, the cooling fan 31 is provided so that the direction of the cooling air is parallel to the outer plate 11 and the main body inner plate 13. That is, the cooling fan 31 has a square cylindrical fan casing 31A and a fan main body 31B rotatably disposed inside the fan casing 31A. The fan main body 31B is rotationally driven by a motor (not shown). . Then, one side surface (left side surface in FIG. 9B) of the fan casing 31A is fixed to the outer plate 11, and the other side surface (right side surface in FIG. 9B) is fixed to the main body inner plate 13, respectively. The cooling air from 31 is configured to flow along the outer plate 11 and the main body inner plate 13.

  A cooling air duct 17 is attached to the cooling fan 31. The cooling air duct 17 has the same configuration as that shown in the first embodiment (see FIGS. 6 and 7 and the like), and one end face (the left end face in FIG. 9A) of the inner duct 171 is a fan casing. The outer duct 172 is fixed to 31A and is rotatable around the inner duct 171.

  A first cooling object 32 is attached to the main body inner plate 13 on the side of the cooling air duct 17. Further, a second cooling object 33 is provided between the main body inner plates 13 and 14. Although not shown in the drawing, the main body inner plate 13 is provided with a through hole at a position facing the second cooling object 33, and the cooling air flowing out from the cooling air duct 17 to the outside passes through the through hole. Then, it is configured to be sent to the second cooling object 33. Other configurations are the same as those in the first embodiment.

  Next, the operation of the image forming apparatus equipped with the cooling mechanism in this embodiment will be described.

  While the brushless motor 21 and the like have stopped rotating during standby when the printing operation is not being performed, the first cooling object 32 needs to be cooled even during standby, so as shown in FIG. The cooling fan 31 rotates in the direction of the arrow A3, so that outside air is sucked in as indicated by the arrow B3 through the intake port 31C. The sucked outside air is sent to the first cooling object 32 through the cooling air duct 17 and flows around the first cooling object 32 as indicated by an arrow C3, whereby the first cooling object. 32 is cooled.

  In this case, as shown in FIG. 6, the cooling air duct 17 is positioned at the lowest position due to its own weight of the driving air receiving portion 172D, and each of the through holes 171A, 171B, 171C of the inner duct 171 and the outer duct 172 are disposed. Since the through holes 172A, 172B, and 172C do not coincide with each other, that is, the shutter is closed, the cooling air from the cooling fan 31 is almost sent to the first cooling object 32.

  Since the brushless motor 21 and the like rotate during the printing operation, the driving wind is generated when the blades 23 attached to the brushless motor 21 rotate in the direction of the arrow A4 as shown in FIG. The inside of the air duct 24 flows as shown by an arrow E, reaches the vicinity of the cooling air duct 17, and the shutter of the cooling air duct 17 is opened.

  When the shutter of the cooling air duct 17 is opened, a part of the cooling air flowing through the cooling air duct 17 passes through the through holes 171A, 171B, 171C of the inner duct 171 and the through holes 172A, 172B, 172C of the outer duct 172. Then, as shown by the arrow D5, the second cooling object 33 flows through the second cooling object 33, and the second cooling object 33 is cooled. At this time, the remaining cooling air flowing through the cooling air duct 17 is sent to the first cooling object 32, and the first cooling object 33 is cooled.

  FIG. 11 is a diagram schematically showing how the cooling air from the cooling fan 31 is sent to the first cooling object 32 and the second cooling object 33 by the cooling air duct 17. That is, a part of the cooling air from the cooling fan 31 is sent to the second cooling object 33 as indicated by arrow D5, and the remaining part is sent to the first cooling object 32 as indicated by arrow C3. .

  According to the present embodiment, the first cooling object 32 that is disposed on the main body inner plate 13 and needs to be cooled even during standby can be reliably cooled, and the main body inner plates 13 and 14 can be used during the printing operation. The internal second cooling object 33 can also be reliably cooled.

  In the present embodiment, fins 171D and 172E as shown in FIG.

Example 3
12 to 15 show a cooling air duct 40 according to the third embodiment. FIG. 12 shows the inner duct 401 of the cooling air duct 40, where (a) is a sectional view and (b) is a side view. FIG. 13 shows the outer duct 402 of the cooling air duct 40, where (a) is a sectional view and (b) is a side view.

  The inner duct 401 has a cylindrical shape, and three through holes 401A, 401B, 401C are formed in a part thereof. These through holes 401A, 401B, 401C have the same configuration as the through holes 171A, 171B, 171C shown in FIG. The outer duct 402 also has a cylindrical shape, and three through holes 402A, 402B, 402C and a driving wind receiving portion 402D are formed in part of the outer duct 402. These through holes 402A, 402B, 402C and the driving wind receiving portion 402D have the same configuration as the through holes 172A, 172B, 172C and the driving wind receiving portion 172D shown in FIG.

  In the cooling air duct 40 of the present embodiment, notches 401D are formed at two locations on the outer peripheral surface of the inner duct 401, and notches 402E are formed at two locations on the inner peripheral surface of the outer duct 402. 14A, the coil spring 41 is interposed between the notch 401D of the inner duct 401 and the notch 402E of the outer duct 402. The coil spring 41 is arranged so that the through holes 401A, 401B, 401C of the inner duct 401 do not coincide with the through holes 402A, 402B, 402C of the outer duct 402, that is, in the direction opposite to the F direction in FIG. Is energized.

  Next, the operation of the cooling air duct 40 in this embodiment will be described.

  At the time of standby, as shown in FIG. 14, the cooling air duct 40 has the driving air receiving portion 402 </ b> D positioned at the lowest position due to its own weight and the urging force of the coil spring 41. 401A, 401B, 401C and the through holes 402A, 402B, 402C of the outer duct 402 do not coincide with each other, and the cooling air flowing inside the cooling air duct 40 reaches the through holes 401A, 401B, 401C as indicated by an arrow D1. However, the cooling air duct 40 does not flow outside.

  During the printing operation, driving wind is generated by rotation of the blades 23 (see FIG. 1 and the like) attached to the brushless motor 21, and this driving wind is supplied as indicated by an arrow E in FIG. 15 to drive the cooling wind duct 40. When hitting the receiving portion 402D, the outer duct 402 is rotated in the direction of arrow F by the wind pressure of the driving wind.

  When the outer duct 402 rotates in the direction of arrow F, each of the through holes 401A, 401B, 401C of the inner duct 401 and each of the through holes 402A, 402B, 402C of the outer duct 402 coincide with each other. A part of the cooling air inside flows out from the cooling air duct 40 through the through holes 401A, 401B, 401C and the through holes 402A, 402B, 402C as indicated by an arrow D2.

  According to the present embodiment, at the time of standby, the outer duct 402 can be reliably returned to the original normal position by the weight of the driving wind receiving portion 402D and the urging force of the coil spring 41.

  Also in this embodiment, fins 171D and 172E as shown in FIG.

DESCRIPTION OF SYMBOLS 10 Image forming apparatus 11, 12 Outer plate 13,14 Main body inner plate 15,16 Cooling fan 17 Cooling air duct 171 Inner duct 171A, 171B, 171C Through hole 171D Fin 172 Outer duct 172A, 172B, 172C Through hole 172D Part 172E Fin 18 First cooling object 19 Second cooling object 20, 21, 22 Brushless motor 23 Blade 24 Drive air duct 31 Cooling fan 32 First cooling object 33 Second cooling object 40 Cooling air Duct 401 Inner duct 401A, 401B, 401C Through hole 402 Outer duct 402A, 402B, 402C Through hole 402D Drive wind receiving portion 41 Coil spring

JP-A-8-272169

Claims (10)

A cooling fan for cooling the first object to be cooled;
A cooling air duct that is provided between the first cooling object and the cooling fan, has a shutter, and guides cooling air from the cooling fan to the first cooling object;
A motor to which a blade having a fan function is attached;
A drive air duct disposed from the vicinity of the blades to the vicinity of the cooling air duct,
When the motor is stopped, cooling air from the cooling fan is sent to the first object to be cooled through the cooling air duct to cool the first object to be cooled,
During the rotation of the motor, the driving air generated by the rotation of the blades is supplied to the vicinity of the cooling air duct through the driving air duct, the shutter is operated, and a part of the cooling air flowing through the cooling air duct is the first. A cooling mechanism which is also sent to the second cooling object and cools the second cooling object together with the first cooling object. An image forming apparatus that transfers an image on a photosensitive member to a sheet sent by a conveying device and fixes the image after transfer by a fixing device,
A cooling fan for cooling the first object to be cooled;
A cooling air duct that is provided between the first cooling object and the cooling fan, has a shutter, and guides cooling air from the cooling fan to the first cooling object;
A brushless motor to which a blade having a fan function is attached;
A drive air duct disposed from the vicinity of the blades to the vicinity of the cooling air duct,
During standby when the brushless motor is stopped, cooling air from the cooling fan is sent to the first cooling object through the cooling air duct to cool the first cooling object,
During the printing operation in which the brushless motor is rotating, driving air generated by the rotation of the blades is supplied to the vicinity of the cooling air duct via the driving air duct, and the shutter is operated to cool the air flowing through the cooling air duct. An image forming measure, comprising: a cooling mechanism in which a part of the wind is supplied also to the second object to be cooled to cool the second object to be cooled together with the first object to be cooled.   The image forming apparatus according to claim 2, wherein the brushless motor is a motor that drives the photosensitive member.   The image forming apparatus according to claim 2, wherein the brushless motor is a motor that drives the fixing device.   The image forming apparatus according to claim 2, wherein the brushless motor is a motor that drives the conveyance device.   The image forming apparatus according to claim 2, wherein the cooling fan is disposed so that cooling air blows out perpendicularly or parallel to a side plate of the image forming apparatus main body. .   The image forming apparatus according to claim 2, wherein the second cooling object is a fixing unit.   The cooling air duct includes a cylindrical inner duct having a through-hole and a cylindrical outer duct having a through-hole and provided in close contact with the outer peripheral surface of the inner duct. 3. The image forming apparatus according to claim 2, wherein a part of the cooling air is supplied to the second object to be cooled when the through hole of the outer duct matches.   The fin according to claim 2, wherein fins are attached to the inner peripheral surface of the inner duct in the vicinity of the through hole, and fins are attached to the outer peripheral surface of the outer duct in the vicinity of the through hole. Image forming apparatus.   Between the outer peripheral surface of the inner duct and the inner peripheral surface of the outer duct, there is interposed a spring that urges the inner duct and the outer duct in opposite directions along the circumferential direction. The image forming apparatus according to claim 2, 8 or 9.