JP5140353B2 - Drive unit and image forming apparatus - Google Patents

Description

  The present invention relates to a drive unit used, for example, for transporting and raising / lowering recording paper in a paper feed cassette, and an image forming apparatus including the drive unit.

  The paper cassette in the image forming apparatus includes, for example, a drive motor for transporting recording paper in the paper feed cassette and an electromagnetic for turning on and off a force transmission system to a transport roller driven by the drive motor or another drive motor. Various heat generating parts such as clutches are used.

For cooling the drive motor as the heat generating component, for example, a cooling fan is attached to the rotation shaft of the drive motor provided in the case to directly cool the drive motor, or the shaft is rotationally driven by the drive motor. A method is proposed in which the cooling fan is driven to rotate, the cooling fan is disposed in the case opening, and the entire area in the case is to be cooled (see, for example, Patent Document 1).
Japanese Patent Laid-Open No. 9-34339

  By the way, in the former case, even if the drive motor can be cooled, other cooling objects cannot be cooled, and a separate fan is required for cooling other cooling objects, which increases the cost. There is a difficulty. On the other hand, in the latter case, since the entire region in the case is cooled, a plurality of objects to be cooled can be cooled by one cooling fan, but there is a drawback that the cooling efficiency of each object to be cooled is lowered.

  The present invention has been made to solve the above-described problems of the prior art, and provides a drive unit and an image forming apparatus capable of cooling each of a plurality of objects to be cooled with high efficiency and reducing costs. For the purpose.

A drive unit according to claim 1 of the present invention includes a substantially hermetically sealed housing having two or more objects to be cooled including a drive motor therein, an air intake hole provided in the vicinity of the drive motor in the housing, An exhaust hole provided in the vicinity of an object to be cooled other than the drive motor, and provided coaxially with the rotation shaft of the drive motor, cools the drive motor with air sucked from the intake hole, and also cools an object other than the drive motor. A cooling fan that cools an object and exhausts the air from the exhaust hole, and is provided in the housing in communication with the intake hole. The air sucked from the intake hole by the cooling fan is directed to the exhaust hole. And a fan gear that guides air blown toward the exhaust port to the exhaust port .

The drive unit according to claim 2 of the present invention is the drive unit according to claim 1, wherein a gear train having the fan gear is installed between the drive motor and a cooling object other than the drive motor. The driving motor and the cooling object other than the driving motor are configured such that the rotation of the driving motor is transmitted to the cooling object other than the driving motor via the gear train, The outlet is separated from the exhaust hole and substantially directed to the exhaust hole.

  The drive unit according to claim 3 of the present invention is the drive unit according to claim 1 or 2, wherein the housing is constituted by a lid and a housing body, and the air duct is formed by the lid and the housing body. It is characterized by being.

  An image forming apparatus according to a fourth aspect of the present invention includes the drive unit according to any one of the first to third aspects.

  In the case of the drive unit and the image forming apparatus according to the present invention, the air sucked from the intake hole by the cooling fan attached to the rotating shaft of the drive motor cools the drive motor that is the cooling object to which the cooling fan is attached. Then, it is led to the exhaust hole through the air duct. Since another cooling object is provided in the vicinity of the exhaust hole, the cooling object is also cooled, and a plurality of cooling objects can be cooled by one cooling fan. Therefore, cost reduction can be achieved. Moreover, since the housing is in a substantially sealed state and each of the objects to be cooled is arranged in the air passage, each of the plurality of objects to be cooled can be cooled with high efficiency.

  In the case of the drive unit according to claim 2 of the present invention, since the outlet of the air duct is separated from the exhaust hole and substantially directed to the exhaust hole, a duct is installed between the outlet of the air duct and the exhaust hole. Even if it is a difficult part, air can be efficiently led to the exhaust hole.

  In the case of the drive unit according to claim 3 of the present invention, the air duct can be easily formed by disposing the object to be cooled in the housing body and closing the lid.

  The present invention will be specifically described below.

  FIG. 1 is a front sectional view for explaining the internal structure of an image forming apparatus 1 to which a drive unit according to the present invention is applied.

  The image forming apparatus 1 is a copying machine, reads an original with an optical unit 2 provided at an upper portion, forms the read content as a toner image on an image forming unit 3, and supplies a paper at a lower portion. 4, the recording paper P conveyed through the conveying line 5 is sent to the image forming unit 3, where the toner image is transferred onto the recording paper P by the transfer unit 6, and then the toner image is fixed by the fixing unit 7. The discharge unit 8 is configured to discharge to the outside. Note that the image forming apparatus 1 of the present embodiment is for color, and the image forming unit 3 includes magenta from the upstream side (right side) to the downstream side along the circumferential direction of the conveying belt 9 that circulates. A unit 3M for cyan, a unit 3C for cyan, a unit 3Y for yellow, and a unit 3K for black are sequentially arranged.

  The sheet feeding unit 4 is configured in two upper and lower stages, and includes an upper sheet feeding unit 4a and a lower sheet feeding unit 4b. The recording sheet P of the upper sheet feeding unit 4a is also the recording sheet P of the lower sheet feeding unit 4b. Is also sent to the image forming unit 3 via the transport line 5. The drive unit 10 according to the present embodiment is provided in the lower paper feed unit 4b. The lower paper feed unit 4b conveys the cassette housing hole 4c indicated by the alternate long and short dash line, the paper feed cassette 4d put in and out of the cassette housing hole 4c, and the recording paper P stored in the paper feed cassette 4d. It has two pairs of transport rollers 4e and 4f and a drive unit 10 for driving these two pairs of transport rollers 4e and 4f. The drive unit 10 is fixed at a predetermined position of the cassette housing hole 4c.

  The transport roller 4e has a roller 4e-1 and a roller 4e-2, one roller 4e-1 is provided in the drive unit 10, and the other roller 4e-2 is provided in the paper feed cassette 4d. When 4d is set in the cassette housing hole 4c, both rollers 4e-1, 4e-2 come into contact with each other. Similarly, the transport roller 4f has a roller 4f-1 and a roller 4f-2, one roller 4f-1 is provided in the drive unit 10, and the other roller 4f-2 is a paper feed cassette 4d. When the paper feed cassette 4d is set in the cassette housing hole 4c, both rollers 4f-1 and 4f-2 come into contact with each other. In the paper feed cassette 4d, the right bottom plate portion is tilted by a motor (not shown), and the pickup roller 4g comes into contact with the upper right end of the uppermost recording paper P, so that the paper can be fed.

  FIG. 2 is a front view showing the drive unit 10, FIG. 3 is a rear view showing the drive unit 10, and FIG. 4 is a front view showing the internal structure of the drive unit 10.

  The drive unit 10 includes a gear 12h to which the roller 4e-1 is mounted concentrically, a gear 12i to which the roller 4f-1 is mounted concentrically, a drive motor 14 that rotationally drives the gears 12h and 12i, and a drive And an electromagnetic clutch 13 for controlling whether or not the rotational force of the motor 14 is transmitted to the gear 12i.

  A gear (not shown) is provided on the rotation shaft 14a of the drive motor 14, and two gears 12j and 12e are provided between the gear of the drive motor 14 and the gear 12h. Between the gear 12i, a gear 12f having an electromagnetic clutch 13 and a gear 12g are provided. Therefore, the rotation of the drive motor 14 is transmitted to the gear 12h through the gears 12j and 12e, and is transmitted to the gear 12i through the gears 12j, 12e, 12f and 12g. The gear 12e is a gear with a fan in which a fan is provided at the center and a gear is formed on the outer periphery.

  When the paper feed cassette 4d is set in the cassette receiving hole 4c, a gear (not shown) provided concentrically with the roller 4e-2 in the paper feed cassette 4d is engaged with the gear 12h, and similarly to the paper feed cassette 4d. A gear (not shown) provided concentrically with the roller 4f-2 meshes with the gear 12i, and the rotation of the drive motor 14 is transmitted to the roller 4e-2 and the roller 4f-2. Therefore, the conveying roller 4e conveys the recording paper P of the paper feed cassette 4d one by one between the rotating rollers 4e-1 and 4e-2, and the conveying roller 4f rotates in the reverse direction. -1 and the roller 4f-2, the recording paper P of the paper feed cassette 4d is sent out from the paper feed cassette 4d.

  The electromagnetic clutch 13 is set to be turned on when energized when the rotation of the drive motor 14 is transmitted to the gear 12i, and is turned off when de-energized when it is not transmitted, and generates heat when energized. It is a heat generating part. The drive motor 14 is also a heat generating component. In the present embodiment, the drive motor 14 and the electromagnetic clutch 13 are objects to be cooled, and a cooling fan 15 is attached to the rotating shaft 14 a of the drive motor 14.

  When the electromagnetic clutch 13 is controlled to turn off, the gear 12i is not driven to rotate, and the feeding of the recording paper P from the paper feed cassette 4d is stopped. Further, a clutch (not shown) is interposed between the gear 12h and the roller 4e-1, and the clutch (not shown) blocks the rotation from the gear 12h so that the paper is not fed by the rotation of the gear 12h. Is to be done.

  The drive unit 10 has an intake port 20a provided in the vicinity of the drive motor 14, an exhaust port 20b provided in the vicinity of the electromagnetic clutch 13, and an opening 20c exposing a part of the gear 12h and a part of the gear 12i. Except for this, it is covered by the housing 20. The housing 20 has a housing body 21 provided with an exhaust port 20b and an opening 20c, and a lid 22 provided with an intake port 20a. When the lid 22 is fitted into the housing body 21, the intake port 20a, The drive unit 10 is substantially blocked except for the exhaust port 20b and the opening 20c. Note that the opening 20c is substantially closed by the gear 12h and the gear 12i. The gear 12i exposed from the opening 20c is a gear (not shown) provided concentrically with the roller 4f-2 in the paper feed cassette 4d by setting the paper feed cassette 4d in the cassette housing hole 4c as described above. Mesh.

  The lid 22 is formed as a circular convex portion 23 in which a portion incorporating the drive motor 14 protrudes outward, and the intake port 20a is arranged on the circular convex portion 23. A gap L1 communicating with the air inlet 20a is formed between the inner surface of the lid 22 and the drive motor 14, and the gap is also formed between the inner surface of the wall 23a of the circular convex portion 23 and the drive motor 14. A gap L2 communicating with L1 is formed. Furthermore, a part of the wall 23a of the circular convex portion 23 is a notch 24, and an air passage 25 is connected to the notch 24, and an outlet 25a of the air passage 25 is directed substantially toward the exhaust port 20b. Yes. The air passage 25 is configured by being surrounded by a pair of opposing walls 25 b and 25 c connected to the wall 23 a of the circular convex portion 23, the lid 22 and the housing body 21.

  The gap L1, the gap L2, and the air passage 25 constitute a blower duct. Therefore, the air that has entered from the intake port 20a is jetted substantially toward the exhaust port 20b through the gap L1, the gap L2, and the air passage 25.

  The rear surface of the housing main body 21 is formed as a circular convex portion 26 in which a portion incorporating the electromagnetic clutch 13 protrudes outward, and the exhaust port 20 b is arranged on the circular convex portion 26. Further, a gap L3 communicating with the exhaust port 20b is formed between the inner surface of the housing body 21 and the electromagnetic clutch 13, and also between the inner surface of the wall 26a of the circular convex portion 26 and the electromagnetic clutch 13. A gap L4 communicating with the gap L3 is formed. Furthermore, a part of the wall 26a of the circular convex portion 26 is a notch 27, and air sent by the fan-equipped gear 12e is supplied to the notch 27. Therefore, the air jetted substantially toward the exhaust port 20b through the air passage 25 is guided to the exhaust port 20b by the fan-equipped gear 12e and exhausted from the exhaust port 20b.

  In the case of the drive unit 10 of the present embodiment configured as described above, the air sucked from the intake hole 20a by the cooling fan 15 attached to the rotating shaft 14a of the drive motor 14 causes the drive motor 14 that is the object to be cooled. After cooling, the air is guided to the exhaust hole 20b through the air duct (gap L1, gap L2, and air passage 25). In the vicinity of the exhaust hole 20b, the electromagnetic clutch 13 that is an object to be cooled is provided. Therefore, the electromagnetic clutch 13 is also cooled, and the drive motor 14 and the electromagnetic clutch 13 are connected by one cooling fan 15. Since two objects to be cooled can be cooled, the cost can be reduced. In addition, since the housing 20 is in a substantially sealed state and the drive motor 14 and the electromagnetic clutch 13 are arranged on the air passageway, it is possible to cool the drive motor 14 and the electromagnetic clutch 13 with high efficiency. it can.

  In the present embodiment, the outlet 25a of the air duct (gap L1, gap L2, and air passage 25) is separated from the exhaust hole 20b and substantially directed to the exhaust hole 20b. Even if the space between the exhaust hole 20b and the gear train 12 is difficult to install a duct, air can be efficiently guided to the exhaust hole 20b. Furthermore, the air duct can be easily formed by disposing the drive motor 14 and the electromagnetic clutch 13 in the housing body 21 and closing the lid 22.

  In the above-described embodiment, the present invention is applied to a drive unit that rotationally drives the paper feed roller. However, the present invention is not limited to this, and is similarly applied to a drive unit that lifts and lowers the tray bottom plate in the paper feed cassette. be able to.

1 is a front cross-sectional view for explaining an internal structure of an image forming apparatus 1 to which a drive unit according to the present invention is applied. It is a front view which shows a drive unit. It is a rear view which shows a drive unit. It is a front view which shows the internal structure of a drive unit.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Image forming apparatus 10 Drive unit 13 Electromagnetic clutch (cooling target object)
14 Drive motor (cooling object)
14a Rotating shaft 15 Cooling fan 20 Housing 20a Intake port 20b Exhaust port 21 Housing body 22 Lid 25 Air passage (air duct)
25a Exit L1 clearance (air duct)
L2 clearance (air duct)

Claims (4)

A substantially hermetically sealed housing having two or more cooling objects including a drive motor therein;
An intake hole provided near the drive motor in the housing;
An exhaust hole provided in the vicinity of an object to be cooled other than the drive motor in the housing;
A cooling fan that is provided coaxially with the rotation shaft of the drive motor, cools the drive motor with air sucked from the suction holes, and exhausts the air from the exhaust holes while cooling a cooling object other than the drive motor. When,
A ventilation duct that is provided in communication with the intake hole in the housing, and sends air sucked from the intake hole by the cooling fan toward the exhaust hole ;
A drive unit comprising: a gear with a fan that guides air blown toward the exhaust port to the exhaust port . The drive unit according to claim 1, wherein
Between the drive motor and an object to be cooled other than the drive motor, a gear train having the fan gear is installed,
The drive motor and the cooling object other than the drive motor are configured such that the rotation of the drive motor is transmitted to the cooling object other than the drive motor via the gear train,
The drive unit, wherein the blower duct is provided in a state in which an outlet thereof is separated from the exhaust hole and substantially directed to the exhaust hole. The drive unit according to claim 1 or 2,
The drive unit, wherein the housing is constituted by a lid and a housing body, and the air duct is formed by the lid and the housing body.   An image forming apparatus comprising the drive unit according to claim 1.

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