JP2005227315A - Drive switch estrangement mechanism - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To perform the estrangement operation of a unit at low costs without adding an electrical member such as a motor. <P>SOLUTION: The drive switch estrangement mechanism includes: a clutch mechanism; a member for holding a developing unit; a cam mechanism which uses the vertical movement of the member of the clutch mechanism and, thereby, lifts the member holding the developing unit; and a stopper mechanism for keeping the developing unit lifted. Every time that power is supplied to a solenoid for a moment, the mechanism performs the operation of switching between the discontinuation and continuation of drive and between the estrangement/abutment of the developing unit from/on a photoreceptor. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a mechanism for performing an intermittent switching operation of a drive and a unit separation / contact operation when transmitting a drive from a motor to a driven side in a color copying machine or a color printer using an electrophotographic technology. It is.

  For convenience, an electrophotographic full-color image forming apparatus in which a plurality of image forming units of different colors are arranged side by side and an intermediate transfer member that moves through each image forming unit is provided will be described as an example.

  When a full-color image is output (in the full-color image formation mode), the image forming apparatus applies each color toner image formed by betting a component color image of a full-color image on the photosensitive drum surface that is an image carrier of each image forming unit. A full-color toner image is synthesized and formed by sequentially superimposing and transferring by a primary transfer means on the surface of the intermediate transfer member moving through the image forming section.

  Then, the full-color toner image synthesized and formed on the surface of the intermediate transfer member is secondarily transferred to a recording material such as paper or a plastic sheet by a secondary transfer unit, and then thermally fused, mixed, Fix and output a full-color image formed product.

  Further, when outputting a monochrome image (in the black image forming mode), only the image forming unit that forms the black toner image among the plurality of image forming units of different colors is operated to perform the image forming unit. The black toner image formed on the surface of the photosensitive drum is primarily transferred onto the surface of the intermediate transfer member, and further transferred to the secondary transfer portion from the surface of the intermediate transfer member to the recording material at the secondary transfer portion. Fix and output a monochrome image formed product.

  When a monochrome image is output, other than the black toner image forming unit, for the purpose of preventing deterioration due to contact between the photosensitive drum and the intermediate transfer member of the image forming unit other than the black toner image forming unit that is not involved in image formation. An intermediate transfer member avoiding mechanism is employed in which the intermediate transfer member is not separated and brought into contact with the photosensitive drums of the other color toner image forming units (see, for example, Patent Document 1).

Japanese Patent Laid-Open No. 9-292753

  However, since the conventional example requires a motor and a drive train for the separation operation, the cost of the motor itself and the power supply etc. can be further increased while the cost of the motor and the drive train are high. Had an influence.

  A first object of the present invention is to provide a drive switching / separating mechanism that enables an operation of separating units / parts using an existing clutch mechanism without adding any electric parts such as a motor.

  A second object of the present invention is to provide a mechanism for driving / disengaging which can easily control the rotational position of the chipped gear in the clutch mechanism and simplify the home position setting.

  In order to achieve the above object, a first invention provides a driving source from a motor, a gear train for transmitting driving, a clutch mechanism for driving intermittently, a unit for separating, and a member for holding the unit And a cam mechanism for lifting the unit using moving parts in the clutch mechanism, and a stopper for holding the member. First, when the solenoid is energized, the clutch is operated, and the drive is cut from the state where the drive is transmitted. At that time, the gear in the clutch mechanism moves in the axial direction, the cam mechanism pushed by the gear lifts the member holding the unit, and the unit is separated. When it is lifted to a certain extent, the stopper moves to hold the member from returning from the separated state. In this state, the clutch is disengaged and the unit is separated. From here, when the solenoid is energized once, the clutch is actuated again, and the drive is disconnected from the disconnected state. At that time, the gear in the clutch mechanism moves in the opposite direction, and the cam that has lifted the member holding the unit returns to its original state. Further, since the stopper which has held the member in the separated state is released in conjunction with the movement of the gear, it is returned to the contacted state. In this state, the clutch transmits driving and the unit is in contact.

  Thus, the drive is interrupted every time the solenoid in the clutch mechanism is energized, and the unit is separated when the drive is cut off.

  In the second aspect of the invention, the drive transmission intermittent mechanism includes a solenoid, a drive intermittent member, a drive transmission gear, and a driven gear. The chipped gear that is rotationally controlled by the flapper of the solenoid has a locking portion for maintaining two states of the clutch driving state and the disconnected state, and further functions in a state where the solenoid is energized and the flapper is sucked. By having the three locking portions, the flapper is always hooked on the third locking portion when the solenoid is sucked for a predetermined time or longer. Thereby, the home position of the clutch mechanism is set.

  According to the present invention, the unit separation operation can be performed in addition to the intermittent switching operation of the drive transmission by simply energizing the solenoid of the clutch mechanism for a moment without newly adding an electric component such as a motor. , Low cost and simple.

  Further, by providing a projection shape on the chipped gear in the clutch mechanism, the home position can be obtained only by energizing the solenoid for a certain period of time without complicated control, thereby enabling quick initialization.

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

<Embodiment 1>
FIG. 1 is a perspective view showing a drive switching / separating mechanism, which best represents the features of the present invention.

  The separation mechanism performs development separation by utilizing the fact that the chipped gear in the clutch mechanism moves up and down.

  FIG. 4 shows a perspective view of the chipped gear incorporated in the clutch mechanism.

  The chipped gear has latching portions 3a, 3b, and 3c on which the solenoid flapper is caught, and is biased in one direction by a spring.

  FIG. 4 is a view showing the movement positions of the chipped gear 3 and the gear 2 when the flapper 8 of the solenoid 9 is located at each position of the locking portion of the chipped gear 3. In the figure of (a), the flapper 8 is hooked on 3a, the chipped gear 3 is located above, and the gear 2 sandwiched between them is also above. Therefore, the coupling portion of the gear 2 does not mesh with the coupling portion of the gear 10 and does not transmit drive.

  Next, when the solenoid 9 is energized and the flapper 8 is sucked, the chipped gear 3 is rotated by a spring, and the flapper 8 is caught by the position 3b and stops (FIG. 4B). And the gear 2 starts to move, at which time the coupling portion of the gear 2 starts to mesh with the coupling portion of the gear 10.

  Next, when the energization of the solenoid 9 is stopped and the flapper 8 becomes free by the spring force, the chipped gear is rotated again and is caught by the locking portion 3c, and the rotation is stopped (FIG. 4 (c)). At this time, the chipped gear is completely lowered. The coupling of the gear 2 is also engaged with the coupling portion of the gear 10 to transmit driving. From this point, when the solenoid is energized again for a certain period of time and the flapper is sucked, the chipped gear moves upward while rotating the helical shape of the meshing bearing 5 and the gear 2 (FIG. 4 (d)). The chipped gear is moved upward and the gear 2 is also moved upward, the coupling part is detached and the drive is cut off. Then, the flapper is caught by the locking portion 3a, and the state returns to the state shown in FIG.

  Even when it is not clear which locking portion the flapper 8 is hooked on, if the solenoid 9 is energized only for the time that the chipped gear 3 makes one or more rounds, the flapper is always hooked on the locking portion 3b. The position of the missing gear is determined.

  Thus, the rotational position control of the chipped gear 3 can be performed by energizing the solenoid 9 for a certain time or more, and the initialization can be performed quickly and easily.

  FIG. 2 is a perspective view showing the clutch mechanism.

  Reference numeral 1 denotes a gear that constantly rotates by transmitting driving from a motor as a driving source. Reference numeral 2 denotes a gear which receives driving from the gear 1 and constantly rotates, and has a coupling shape on the side facing the gear 10 and is held so as to be movable in the axial direction. Reference numeral 3 denotes a chipped gear that meshes with the gear 2, and when it rotates, it moves up and down in the axial direction by the spiral shape cut inward and the spiral shape of the bearing 5, and the chipped gear 3 sandwiches the gear 2 together with the flange 4a. Therefore, the gear 2 also moves in conjunction with the vertical movement of the chipped gear 3. 4b is a chipped spring that pushes the chipped gear 3 in the -Y direction.

  Reference numeral 7 denotes a chipped tooth biasing spring attached to a spring hook 6 rotatably installed on the flange 4a, and performs a biasing force of the chipped gear 3 in one direction. Reference numeral 8 denotes a flapper attached to the solenoid 9 so as to be able to swing, and the rotational position is controlled by being caught by the engaging portion of the chipped gear 3. 10 has a coupling shape on the side facing the gear 2, and when the gear 2 moves in the −Y direction, it engages with the coupling portion of the gear 2 to receive the drive, and transmits the drive to the gear 11. The gear 11 receives the drive from the gear 10 and transmits the drive to the gear 16 of the cartridge in FIG.

  In operation, every time the solenoid 9 is energized and the flapper 9 is attracted, the chipped gear 3 rotates at a certain angle and simultaneously moves up and down in the axial direction. Thus, the gear 2 that moves in conjunction with the chipped gear 3 also moves up and down in the axial direction every time the solenoid 9 is energized. At this time, when the gear 2 is in the upward direction, the coupling portion does not mesh with the coupling portion of the gear 10, so that the drive from the gear 1 is transmitted to the gear 2 but not to the gear 10. When the gear 2 is in the −Y direction, the coupling portion meshes with the coupling portion of the gear 10, so that the drive is transmitted to the gear 10. In this way, each time the solenoid 9 is energized, the chipped gear 3 moves up and down, and the coupling portion of the gear 2 interlocked therewith engages and disengages to perform intermittent driving.

  Next, the structure of the separation mechanism will be described by taking separation of the cartridge as an example.

  Reference numeral 12a in FIG. 1 denotes a separation cam that contacts the flange 4 and the separation rod 13, and swings around the central axis 12b to move the separation rod 13 up and down. The separation rod 13 holds the cartridge swinging portion 15b and is pushed up in the Z direction in the drawing by the separation cam 12a. At this time, the cartridge swinging portion 15 b swings about the swinging shaft 15 c, and the developing sleeve 20 that is in contact with the drum 17 is separated from the drum 17.

  Further, the separation rod 13 is biased in the −Z direction by the spring 14. Reference numeral 15 a denotes a cartridge fixing portion, which holds the drum 17. Reference numeral 18 denotes a stopper that keeps the separation rod 13 from returning to the −Z direction by the rod biasing spring 14. Reference numeral 19 denotes a pushing spring that pushes the stopper 18 toward the separating rod 13.

  In the above configuration, the solenoid 9 is energized from the state in which the chipped gear 3 of the clutch mechanism is in the −Y direction and the coupling portion of the gear 2 and the gear 10 is engaged with each other to transmit the drive as shown in FIG. Is performed once, the chipped gear 3 is rotated by the chipped biasing spring 7 and meshes with the gear 2 to move in the + Y direction by moving up the spiral shape of the bearing 5 (b). At the same time, the toothless gear and the gear 2 sandwiched between the flanges 4 are also moved in the + Y direction in conjunction with each other, so that the coupling portion is not engaged and the drive is cut off. At this time, as shown in FIG. 3B, when the chip gear 3 moves in the + direction, the separating cam 12a rotates and pushes up the separating rod 13 upward (+ Z direction). At the same time, the spacing rod 13 in FIG. 3D holds the cartridge swinging portion 15 b and swings about the swinging shaft 15 c in accordance with the movement of the spacing rod 13. Separate. When the separating rod 13 is pushed up to a certain position, as shown in FIG. 3B, the stopper 18 pushed by the pushing spring 19 enters the concave portion of the rod, and the separating rod is held so as not to be lowered in the −Z direction. To do. With this operation, the cartridge drive is cut off, and the developing sleeve is separated from the drum 17.

  Next, when the solenoid 9 is energized once again and the flapper 8 is sucked, the chipped gear 3 is rotated by the chipped biasing spring 7, and the chipped gear 3 is pushed in the -Y direction by the chipped pressing spring 4b. Then, it moves in the -Y direction by moving down the spiral shape of the bearing. Then, the gear 2 also moves in the −Y direction, the coupling portion meshes, and the drive is transmitted to the gear 10 again. At this time, when the chip gear 3 moves in the -Y direction as shown in FIG. 3A, the stopper 18 is pushed back in the -Y direction by the flange 4a. The release rod 13 held by the stopper so as not to go in the −Z direction is pulled by the rod biasing spring and moved in the −Z direction due to the movement of the stopper. As a result, the cartridge swinging portion 15 b sandwiched between the release rods swings to the original state around the swinging shaft 20, and the developing sleeve comes into contact with the drum 17. By this operation, the cartridge drive is transmitted again, and the developing sleeve comes into contact with the drum 17.

  As described above, it is possible to repeat the cartridge drive intermittent operation and the developing separation operation every time the solenoid is energized without adding an electric component such as a motor.

  The present invention is considered to be applicable not only to devices using electrophotographic technology but also to devices and apparatuses using a drive transmission mechanism.

It is a perspective view of the drive switching separation mechanism concerning Embodiment 1 of the present invention. It is a perspective view of the clutch mechanism which concerns on Embodiment 1 of this invention. It is explanatory drawing of the drive switching separation mechanism which concerns on Embodiment 1 of this invention. It is a figure explaining the position control of the solenoid which concerns on Embodiment 2 of this invention.

Explanation of symbols

1 drive gear 3 chipped gear 4a flange 4b chipped spring 5 bearing 8 flapper 9 solenoid 12a spacing cam 13 spacing rod 15a cartridge fixing portion 15b cartridge swinging portion 15c swinging shaft 17 drum 18 stopper 20 developing sleeve

Claims (4)

A driving source, a driven train transmitted from the driving source via a gear train, a clutch mechanism for interrupting driving from the driving source to the driven train, a member for holding the developing device, and a developing device. A cam mechanism that lifts a member to be held, and a stopper mechanism that maintains a state in which the developing device is lifted; a first state in which the driving force of the clutch is turned on to contact the developing device and the photosensitive member; A switching mechanism capable of alternately switching between a second state in which the drive transmission is turned off and the developing device and the photosensitive member are separated from each other,
Driving switching characterized in that the coupling is moved in the axial direction by an actuator to switch the drive transmission ON / OFF, and at the same time, the movement of the coupling is used as a driving source to perform contact / separation operations of the developing device. Separation mechanism.   The coupling that performs ON / OFF switching of drive transmission is a gear that always rotates in the clutch mechanism, and is a member that meshes with a coupling portion of a gear that is rotatably installed on the same axis and transmits drive. The drive switching separation mechanism according to claim 1.   The actuator for moving the coupling in the axial direction is a member that receives a drive from a drive source and moves up and down by rotating with respect to a member having a fixed spiral cam. The drive switching separation mechanism described.   An actuator that moves the coupling in the axial direction is a chipped gear, and this chipped gear is rotationally controlled by a flapper of a solenoid, and when the chipped gear is stopped at the first locking portion of the flapper The gear having the coupling shape is in a position in which the drive is cut off, and the gear having the coupling shape is in the position in a state of transmitting the drive when stopping at the second locking portion, and the third locking When the solenoid stops, it is in a position to transmit the drive, and when the solenoid is energized for a certain period of time, the chip gear is always stopped at this position. From the first locking portion to the second locking portion The movement when moving from the second locking portion to the first locking portion is performed by energizing the solenoid for a moment, and this chipped gear has a fixed helical shape The cam When the chipped gear is moved up and down by energizing the solenoid, it is sandwiched between the flanges of the chipped gear and has a coupling shape installed rotatably on the shaft. The gear also moves up and down at the same time, telling the drive when the gear coupling part meshes, cutting the drive when the coupling is released, and the cam that lifts the member that holds the developer when the chipped gear goes up When the mechanism is pushed up, the developing device is lifted and the developing device is separated, and at this time, the member holding the developing device is raised, the stopper is operated to maintain the separated state, When the flapper of the solenoid that controls the rotation of the chipped gear is sucked and the chipped gear is lowered, the flange stopper of the chipped gear is pushed and the developer Drive switching separation mechanism according to claim 1, wherein lifting to have members developing device by returning to the original state by the spring force, characterized in that the return to the contact state.

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