JP4780729B2 - Drive transmission device and image forming apparatus - Google Patents

Description

  The present invention relates to an image forming apparatus such as a copying machine, a printer, and a facsimile. The present invention also relates to a drive transmission device that is applied to an image forming drive system in such an image forming apparatus and transmits the rotation of a drive motor to an image carrier, a paper feed roller, a fixing roller, and the like via a gear train.

  Conventionally, in a printer device, for example, as described in Patent Document 1, a gear shaft is formed integrally with a resin cover, and gears of a gear train are rotatably supported by the gear shaft. Some of them include a drive transmission device that attaches a resin cover that supports the side cover to a side plate frame that constitutes a structure in the printer apparatus body.

JP-A-7-304233

  However, in such a drive transmission device, if the side plate frame is made of sheet metal, it becomes expensive. In addition, if it is a resin molded product, the gear shaft vibrates due to insufficient rigidity, and the side plate frame vibrates together with the resin cover itself, and the vibration propagates to the resin outer cover of the printer device, for example. There was also a problem of generating noise based on vibrations of the resin cover and the side plate frame as well as rubbing noise and tapping noise.

  SUMMARY OF THE INVENTION Accordingly, a first object of the present invention is to reduce the generation of noise caused by vibration of a resin cover, a side plate frame, and the like, in the drive transmission device described above, which can be manufactured at low cost. .

  A second problem is to further reduce the cost by reducing the number of parts.

  The third problem is to further reduce the cost by reducing the number of parts and to further improve the assemblability.

  A fourth problem is to reduce the generation of noise by applying it to an image forming apparatus and reducing the cost similarly.

Therefore, this invention is to solve the first problem described above.
In the drive transmission device that transmits the rotation of the drive motor via the gear train,
The drive motor is provided on the plate surface of the resin frame constituting the structure of the image forming unit of the image forming apparatus, and the gear shaft is formed by integral molding.
The gear shaft is rotatably supported by the gear shaft, and the rotation of the drive motor is transmitted to the image carrier of the image forming unit through the gear train,
A sheet metal frame is attached to the resin frame, and the plate surface of the sheet metal frame is pressed against or fitted to the gear shaft .
It is characterized by that.

In the drive transmission device that transmits the rotation of the drive motor via the gear train,
A gear shaft is formed by integral molding on the plate surface of the resin frame constituting the structure of the image forming unit of the image forming apparatus,
The gear shaft is rotatably supported by the gear shaft, and the rotation of the drive motor is transmitted to the image carrier of the image forming unit through the gear train,
A sheet metal frame is attached to the resin frame, and a plate surface of the sheet metal frame is pressed against or fitted to the gear shaft, and is between the resin frame and the sheet metal frame, and the sheet metal frame. A motor gear side surface is attached to the frame side and the drive motor is provided.
It is characterized by that.

In order to solve the third problem, to form a stud integrally molded on the plate surface of the resin frame, screwed to the stud, it has good when attaching the sheet metal frame to the plastic frame.

  In order to solve the second problem, the heat dissipation bracket of the drive motor may be used as a sheet metal frame.

  In order to solve the fourth problem, the image forming apparatus may include the drive transmission device as described above.

  According to the present invention, a complicated and relatively large frame constituting the structure is made of an inexpensive resin, and a simple and relatively small frame to be attached to the frame is made of an expensive sheet metal.

  In addition, since the gear shaft is integrally formed on the plate surface of the resin frame, and the gear of the gear train is rotatably supported by the gear shaft, the gear can be supported at low cost.

  Furthermore, since the sheet metal frame is attached to the resin frame, it is possible to suppress the vibration of the resin frame with a more rigid and strong sheet metal frame and prevent noise generated by propagation to the resin outer cover or the like. it can.

  According to the invention of claim 3, since the stud is integrally formed on the plate surface of the resin frame, there is no need to provide a separate stud, the number of parts is reduced, and the cost is reduced, and the stud is screwed to the stud. Since the sheet metal frame is attached to the resin frame, the sheet metal frame can be easily attached while holding a space for housing the gear between the resin frame.

Further , according to the present invention, when the sheet metal frame is attached to the resin frame, the plate surface of the sheet metal frame is pressed against the gear shaft or fitted to the gear shaft. The vibration can be reliably suppressed, the vibration of the resin frame can be prevented, and the vibration can be prevented from propagating to the resin outer cover.

According to the invention which concerns on Claim 4 , since the bracket for heat radiation of a drive motor is utilized also as a metal-made frame, in addition to the said effect, a number of parts can be reduced and the further cost reduction can be aimed at.

According to the fifth aspect of the present invention, when the structure in the image forming apparatus main body is made of a resin material to reduce the cost, a part of the structure is used as a resin frame that supports the gear train. By attaching a sheet metal frame to it, the vibration of the resin frame can be eliminated, the propagation of vibration to the exterior cover can be prevented, and the generation of noise can be reliably prevented.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
FIG. 1 shows an overall schematic configuration of an image forming apparatus including a drive transmission device according to the present invention.

  Reference numeral 10 in the figure denotes an image forming apparatus main body. The apparatus main body 10 includes an image forming unit 20 and an image reading unit 40 thereon.

  An image forming unit 21 is provided in the image forming unit 20. The image forming unit 21 includes a drum-shaped image carrier 23 that is partially exposed from the opening in the unit case 22, and has a roller-shaped charging unit 24, a developing roller 25, and the like around the drum-shaped image carrier 23. Means 26, cleaning means 27, etc. are provided.

  The image forming unit 20 has a paper feed tray 28 attached to the right side and a paper discharge tray 29 attached to the left side.

  A recording paper conveyance path 30 is formed under the image forming unit 21. A paper feed roller 31 is provided on the right side along the recording paper conveyance path 30, a roller-like transfer unit 32 is provided below the image carrier 23, and a fixing unit 33 is provided on the left side. The fixing unit 33 includes a fixing roller 34 and a pressure roller 35, and a discharge roller pair 36 is provided at the exit. A writing means 37 is provided above the image forming unit 21.

  On the other hand, the image reading unit 40 includes an automatic document feeder 42 on the optical system storage device 41 that can be opened and closed up and down. The optical system storage device 41 stores a CCD unit 43 together with an optical system (not shown), and a contact glass 44 on the upper surface.

  The automatic document feeder 42 is provided with a document placement table 45, and a document conveyance path 46 for conveying a document fed therefrom is formed. A document pickup roller 47, a document separation pad 48, a document feed roller 49, and a previous document transport roller pair 50 are provided on the left side of the reading position R along the document transport path 46. On the right side of the reading position R, a rear document transport roller pair 51 is provided, and a document receiver 52 is attached.

  And when making a copy now, a power switch (not shown) is turned on. When the automatic document feeder 42 is used, the document is set on the document table 45, and when not used, the automatic document feeder 42 is opened and the document is set on the contact glass 44. Next, a start switch (not shown) is turned on to drive the image forming unit 20 and operate the image reading unit 40.

  Thus, when the automatic document feeder 42 is used, the document pickup roller 47 feeds out the set document to the document transport path 46, and the document separation pad 48 separates them one by one and transports them by the document feed roller 49. The front document transport roller pair 50 feeds the document to the reading position R.

  At the reading position R, the optical system inside the optical system storage device 41 emits light, the reflected light enters the CCD unit 43, and the image reading unit 40 sequentially reads the image information on the document surface while conveying the document. The original after image reading is discharged onto the original receiver 52 by the rear original document conveyance roller pair 51.

  When the automatic document feeder 42 is not used, the optical system in the optical system storage device 41 is moved along the contact lens 44, and the set document on the contact glass 44 is read by the image reading unit 40.

  On the other hand, in the image forming unit 20, as the image carrier 23 rotates, the surface of the image carrier 23 is first uniformly charged by the charging unit 24, and then the writing unit 37 according to the content read by the image reading unit 40. Then, for example, an electrostatic latent image is formed on the image carrier 23 by performing writing by irradiating a laser beam. Subsequently, toner is attached by the developing roller 25 of the developing unit 26, and the electrostatic latent image is visualized to form an image on the image carrier 23.

  On the other hand, the sheet feeding roller 31 is rotated to feed the recording sheet on the sheet feeding tray 28 to the recording sheet conveying path 30, and the image formed on the image carrier 23 is timed to match the image carrier 23. Transport toward the bottom of Then, the transfer unit 32 is used to transfer the image on the image carrier 23 onto the same recording paper. The recording paper after the image transfer is fixed on the transfer image by the fixing unit 33, and is then discharged out of the image forming unit 20 and stacked on the paper discharge tray 29.

  After the image transfer, the image carrier 23 is rotated and the residual toner on the surface is removed by the cleaning unit 27, and then the surface is neutralized by a neutralizing unit (not shown) to prepare for image formation again.

  In the image forming apparatus described above, the image carrier 23, the paper feed roller 31, the transfer means 32, the fixing roller 34, and the paper discharge roller 36 are not shown in FIG. 1, but according to the present invention as shown in FIG. Rotation is transmitted using the drive transmission device A.

  The drive transmission device A is provided with a drive motor 60 and a gear train G for transmitting the rotation. The gear train G is composed of first to seventh gears 61 to 67.

  Then, as shown in FIG. 3, the rotation of the drive motor 60 is transmitted to the third gear 63 via the first gear 61 and the second gear 62, and the third gear 63, the image carrier gear 23a, Is transmitted to the image carrier 23 through the meshing. Further, the rotation of the image carrier 23 is transmitted to the transfer means 32 through the meshing of another image carrier gear 23b and the transfer means gear 32a.

  The rotation of the second gear 62 is transmitted to the sixth gear 66 through the fourth gear 64 and the fifth gear 65, and is transmitted to the fixing roller 34 through meshing with the fixing roller gear 34a. Further, the rotation of the fixing roller 34 is transmitted to the paper discharge roller 36 through meshing of another fixing roller gear 34b and the paper discharge roller gear 36a.

  The rotation of the second gear 62 is also transmitted to the paper feed roller 31 via the seventh gear 67 and the like.

  By the way, the drive motor 60 and the gear train G described above are supported by a resin frame 70 as shown in FIG. The resin frame 70 constitutes the structure of the image forming unit 20 of the image forming apparatus.

  That is, the drive motor 60 is provided inside the resin frame 70, and only the motor gear 60a is provided outside.

  On the other hand, the gear train G is provided outside the resin frame 70. The resin frame 70 is formed integrally with a plurality of gear shafts 71 on the plate surface, and the gear shaft 71 rotatably supports some of the first to seventh gears 61 to 67 of the gear train G. . In particular, the first gear 61 and the second gear 62 near the drive motor 60 are preferably attached to a gear shaft 71 formed integrally with the plate surface of the resin frame 70.

  A plurality of studs 72 are formed on the plate surface by integral molding on the resin frame 70, and the sheet metal frame 74 is attached to the resin frame 70 by screwing the stud 72 with screws 73. At this time, the plate surface of the sheet metal frame 74 is pressed against the tip of the gear shaft 71, and the gear shaft 71 is pressed to prevent the gear shaft 71 from shaking when transmitting the rotation. In order to effectively prevent shaking, it is preferable to provide a stud 72 near the gear shaft 71.

  Then, the outside of the sheet metal frame 74 is covered with a resin exterior cover 75 attached to the image forming unit 20.

  In the example described above, when the sheet metal frame 74 is attached to the resin frame 70, the plate surface of the sheet metal frame 74 is pressed against the gear shaft 71, but the plate surface of the sheet metal frame 74 is against the gear shaft 71. For example, the gear shaft 71 may be prevented from shaking during rotation transmission by being fitted with unevenness.

  In the above-described example, the case where the present invention is applied to the image forming drive system of the image forming apparatus has been described. However, the present invention can be applied not only to the image forming drive system but also to other drive systems of the image forming apparatus.

  For example, as shown in FIG. 5, a gear shaft 71 is integrally formed as shown in FIG. 6 on a plate surface of a resin frame 70 constituting the structure of the device, and the gear shaft 71 is used to form a gear train G. 1 gear 61 is rotatably supported. In this example, the gear train G includes a first gear 61, a second gear 62, and a third gear 63.

  Also in this example, the stud 72 is formed integrally on the plate surface of the resin frame 70, and the stud 72 is screwed to the stud 72 with the screw 73, and the sheet metal frame 74 is attached to the resin frame 70, and the sheet metal frame The plate surface 74 is pressed against the tip of the gear shaft 71.

  In this example as well, the drive motor 60 is attached to the inside of the resin frame 70, and the motor gear 60a attached to the motor shaft provided through the resin frame 70 is provided on the front side so as to mesh with the first gear 61. To do.

  By the way, in the example mentioned above, the drive motor 60 was attached to the resin frame 70, respectively. However, as shown in FIG. 7, a heat radiating bracket for radiating motor heat is attached to the drive motor 60 using screws 76, and the heat radiating bracket is used as a sheet metal frame 74, as shown in FIG. You may make it attach to the resin-made flame | frame 70 which comprises a structure using the screw 73. FIG. The plurality of screws 73 are screwed to studs 72 formed integrally with the plate surface of the resin frame 70.

  Also in this example, as shown in FIG. 9, a gear shaft 71 is formed integrally on the plate surface of the resin frame 70, and the first gear 61 and the second gear 62 of the gear train G are connected by the gear shaft 71. Support for rotation.

  Similarly, as shown in FIG. 10, a heat dissipation bracket is attached to the drive motor 60, the heat dissipation bracket is used as a sheet metal frame 74, and a resin frame 70 constituting a structure is formed using screws 73. You may make it attach to. In addition, the code | symbol used in a figure uses the code | symbol used for the corresponding part in the example mentioned above as it is, and abbreviate | omits duplication description.

1 is an overall schematic configuration diagram of an image forming apparatus including a drive transmission device according to the present invention. It is a description perspective view of the drive transmission device. It is a rotation transmission flowchart. 2 is a perspective view of an image forming unit of the image forming apparatus. FIG. It is a perspective view of the other example of the drive transmission device by this invention. It is a perspective view explaining attachment of the 1st gear. It is a disassembled perspective view of the drive motor which shows the further another example of the drive transmission device by this invention. It is a perspective view which shows the attachment state of the drive motor. It is a perspective view which shows the state after the attachment. It is a perspective view of the further another example of the drive transmission device by this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Image forming apparatus main body 20 Image forming part 40 Image reading part 60 Drive motor 61 1st gear 62 2nd gear 63 3rd gear 64 4th gear 65 5th gear 66 6th gear 67 7th Gear 70 Resin frame 71 Gear shaft 72 Stud 73 Screw 74 Sheet metal frame A Drive transmission device G Gear train

Claims (5)

In the drive transmission device that transmits the rotation of the drive motor via the gear train,
The drive motor is provided on the plate surface of the resin frame constituting the structure of the image forming unit of the image forming apparatus, and the gear shaft is formed by integral molding.
The gear shaft is rotatably supported by the gear shaft, and the rotation of the drive motor is transmitted to the image carrier of the image forming unit through the gear train,
A drive transmission device, wherein a sheet metal frame is attached to the resin frame, and a plate surface of the sheet metal frame is pressed against or fitted to the gear shaft . In the drive transmission device that transmits the rotation of the drive motor via the gear train,
A gear shaft is formed by integral molding on the plate surface of the resin frame constituting the structure of the image forming unit of the image forming apparatus,
The gear shaft is rotatably supported by the gear shaft, and the rotation of the drive motor is transmitted to the image carrier of the image forming unit through the gear train,
A sheet metal frame is attached to the resin frame, and a plate surface of the sheet metal frame is pressed against or fitted to the gear shaft, and is between the resin frame and the sheet metal frame, and the sheet metal frame. A drive transmission device in which a motor gear side surface is attached to a frame side and the drive motor is provided.   3. The drive transmission device according to claim 1, wherein a stud is integrally formed on a plate surface of the resin frame, and the metal plate frame is attached to the resin frame by screwing to the stud. 4. Wherein the heat dissipation bracket of the drive motor formed by utilizing as the sheet metal frame, the drive transmission device according to any one of claims 1 to 3. Comprising a drive transmission device according to any one of claims 1 to 4, the image forming apparatus.

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