JP2005054934A - Drive connection mechanism, sheet elevating/lowering device, and image forming device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve problems wherein the phase of projecting parts of a pair of couplings is different from each other every time in a conventional pair of couplings, a drive side coupling is idled before the pair of couplings are engaged and the drive can be transmitted, and the drive is not rapidly transmitted. <P>SOLUTION: When an object to be driven is pulled out of a body, a driven side coupling is constituted in a predetermined waiting phase, and the phase when the drive of the driving side coupling is completed has a predetermined relationship to the waiting phase of the driven side coupling. In the phase relationship, the driven side coupling is at the phase angle at which a tip of the projecting part is not collided with a tip of the driving side coupling. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a drive coupling mechanism for transmitting driving, a sheet lifting apparatus using the same, and an image forming apparatus.

  2. Description of the Related Art Conventionally, as a structure of a drive transmission unit to a driven object configured to be detachable from the apparatus main body, there is a structure shown in FIG. 7, for example (see, for example, Patent Document 1).

  Explaining this, a driven-side coupling 101 provided in the apparatus main body, a driven body having a driven-side coupling 102 coupled to the driving-side coupling and configured to be detachable from the apparatus main body; It has.

  Both couplings have a plurality of recesses and projections extending in the axial direction and adjacent to each other in the circumferential direction, and a detection means 103 for detecting the rotational phase of the drive side coupling in the apparatus body; Drive means 104 is provided for always stopping the drive side coupling at a constant phase angle based on the detection result of the detection means.

The driven body is mounted in a state where the driven side coupling is adjusted to a phase angle at which the tip of the convex portion does not collide with the tip of the convex portion of the driving side coupling.
JP 2002-132092 A

  In the conventional apparatus described above, a detection unit that detects the rotational phase of the driving side coupling and a driving unit that always stops the driving side coupling at a constant phase angle based on the detection result of the detection unit are necessary. In addition to hindering downsizing / cost reduction of the apparatus, the effect cannot be expected because the phase detection means and the drive means for stopping at a constant phase angle based on the detection result of the detection means do not operate in the power-off state. was there.

  Further, in the conventional coupling pair that does not guarantee the avoidance of the collision of the convex portion of the coupling pair, the convex phase of the coupling pair is different every time, and the coupling pair is engaged to enable drive transmission. The drive side coupling needs to run idle until the drive transmission is not performed promptly.

  The present invention has been made paying attention to the above points, and the driven side coupling is mounted in a state in which the leading end of the convex portion is adjusted to a phase angle that does not collide with the leading end of the convex portion of the driving side coupling. Therefore, it is easy to smoothly engage the coupling, and the operation of mounting the driven body can be easily performed. In addition, since the coupling meshes smoothly, it is possible to shorten the coupling idle running time that was conventionally required until the coupling meshes, and the drive input to the driven body is performed quickly. It is an object of the present invention to provide a drive coupling mechanism, a sheet lifting apparatus, and an image forming apparatus that have a quick return operation after detachment and are easy to use.

  The present invention comprises a driving side coupling provided in the apparatus main body, and a driven body configured to be detachable from the apparatus main body having a driven side coupling coupled to the driving side coupling, The two couplings are an image forming apparatus having a plurality of recesses and projections extending in the axial direction and adjacent to each other in the circumferential direction, and when the driven body is pulled out from the main body The driven side coupling is configured to have a fixed standby phase, and the phase at the end of driving of the driving side coupling has a fixed relationship with the standby phase of the driven side coupling, and the fixed relationship Is characterized in that the driven side coupling has a phase angle at which the tip of the convex part does not collide with the tip of the convex part of the driving side coupling.

  In more detail, the present invention can solve the above problems by the following configuration.

  (1) a driving-side coupling provided in the apparatus main body, and a driven body configured to be detachable from the apparatus main body having a driven-side coupling coupled to the driving-side coupling, Both couplings have a plurality of concave and convex portions extending in the axial direction and adjacent to each other in the circumferential direction, and are driven when the driven body is pulled out from the main body. The side coupling is configured to be a fixed standby phase, and the phase at the end of driving of the driving side coupling has a fixed relationship with the standby phase of the driven side coupling, and the fixed relationship The drive coupling mechanism, wherein the driven side coupling has a phase angle at which the tip of the convex portion does not collide with the tip of the convex portion of the drive side coupling.

  (2) When the coupling pair according to (1) is applied to drive transmission of the sheet lifting and lowering means of the sheet storage portion in the sheet storage device, the sheet storage portion is taken out from the sheet storage device. In the seat lifting apparatus in which the lifting means is located at a predetermined standby position by its own weight, a spring or the like, the driven lifting coupling is directly connected to the seat lifting means, so that the seat lifting means becomes the predetermined standby position. A seat elevating device characterized by having a standby phase that is sometimes determined.

  (3) An image forming apparatus characterized in that an image is formed on a sheet fed from a sheet storage unit provided with the sheet lifting / lowering means according to (2), but the sheet forming unit is provided.

  According to the present invention, the driven body is driven-side coupled without using the phase detecting means as shown in the conventional example or the driving means for stopping at a constant phase angle based on the detection result of the detecting means. However, since the tip of the convex portion is mounted in a state adjusted to a phase angle that does not collide with the tip of the convex portion of the driving side coupling, it is easy to smoothly engage the coupling, Mounting operation can be performed easily. In addition, since the coupling meshes smoothly, it is possible to shorten the coupling idle running time that was conventionally required until the coupling meshes, and the drive input to the driven body is performed quickly. It is possible to provide a device that is quick to return after detachment and is easy to use.

  Hereinafter, the best mode for carrying out the present invention will be described in detail with reference to examples.

  An embodiment of the present invention will be described with reference to FIGS. 1 to 6 by taking cassette lifter driving in an image forming apparatus as an example. FIG. 1 is a schematic sectional view of an image forming apparatus to which the present embodiment is applied. Reference numeral 1 denotes an image forming apparatus, 2 denotes a paper feeding device, 3 denotes a cassette, 4 denotes a paper feeding unit, 5 denotes an image forming unit, 6 denotes a fixing device, 7 denotes a discharge port, and S denotes a sheet. 2A and 2B show details of the cassette 3.

  8 is a middle plate for stacking sheets. The lifter plate (not shown) connected to the lifter gear 9 swings according to the remaining amount of stacked sheets and supplies the sheet S to the sheet feeding unit 4. Reference numeral 10 denotes a cassette side coupling for inputting drive to the lifter gear 9. 2A is a perspective view showing a state in which the cassette is pulled out from the main body or a state in which the paper is full, and FIG. 2B is a perspective view showing a state in which the paper in the cassette is exhausted.

  FIG. 3 is a view showing in detail the cassette lifter motor 11 attached to the image forming apparatus main body side. Reference numeral 12 denotes a main body side coupling, and reference numeral 13 urges the main body side coupling 12 toward the front end of the cassette lifter motor shaft. It is a biasing spring. FIG. 4 is a perspective view showing a state where the cassette lifter motor 11 and the cassette side coupling 10 are separated from each other. FIG. 5 is a perspective view showing the connection between the cassette lifter motor 11 and the cassette side coupling 10.

  Next, the operation of the present embodiment will be described.

  The cassette 3 in the present invention is configured to be detachable from the image forming apparatus 1, and the cassette S lifter drive is performed by the main body side coupling 12 and the cassette side coupling 10 that can be brought into and out of contact with each other to raise and lower the sheet S in the cassette 3. Communicated. FIG. 4 shows a view in which the cassette 3 is separated from the image forming apparatus 1 and the main body side coupling 12 and the cassette side coupling 10 are separated. FIG. 5 is a diagram in which the cassette 3 is accommodated in the image forming apparatus 1 and the main body side coupling 12 and the cassette side coupling 10 are engaged.

  When the cassette lifter motor 11 is driven based on a paper surface height sensor (not shown) provided in the paper feeding unit 4 so that the uppermost surface of the sheet S in the cassette 3 has a constant height, the main body side coupling 12 and The driving force of the cassette lifter motor 11 is transmitted by the cassette side coupling 10, and the lifter gear 9 that engages with the cassette side coupling 10 rotates to raise the intermediate plate 8, thus keeping the uppermost surface of the sheet S constant. Control to height.

  FIG. 2A shows a state in which the cassette is pulled out from the main body or a state in which the paper is full. The middle plate 8 is lowered to its lowest position by its own weight, and the lifter gear 9 and the cassette side coupling 10 are operated by the middle plate 8. Is rotated by. The phase of the cassette side coupling 10 when the intermediate plate 8 is at the lowest position is referred to as a cassette side coupling standby phase.

  FIG. 2B shows a state when the sheet S in the cassette is exhausted. In order to supply the sheet S to the sheet feeding unit 4, the intermediate plate 8 is swung by a cassette lifter motor 11, which will be described later, via the cassette side coupling 10 and the lifter gear 9. The posture is as shown in 2 (b). The phase of the main body side coupling 12 when the intermediate plate 8 is in the position without the sheet S is referred to as a main body side coupling operation end phase.

  Here, the cassette side coupling standby phase of the cassette side coupling 10 and the main body side coupling operation end phase of the main body side coupling 12 will be described with reference to FIGS. 6 (a) to 6 (c). FIG. 6A is a front view of the cassette side coupling 10 as viewed from the cassette lifter motor 11 side. The cassette side coupling standby phase is a phase as shown in FIG.

  FIG. 6B shows a state in which the convex portions of the cassette side coupling 10 and the main body side coupling 12 mesh with each other to transmit the drive, and the cassette side at the end of the main body side coupling operation end phase is shown. It is a figure which shows the phase of the coupling 10 and the main body side coupling 12. FIG. When the sheet S becomes empty in the cassette, the phase shown in FIG.

  FIG. 6C is a diagram showing a state when the cassette 3 is pulled out from the main body 1 (for example, for replenishing the sheet S to the cassette 3), and then the cassette 3 is mounted on the main body again.

  As described above, when the cassette 3 is pulled out from the main body, the cassette side coupling 10 enters the cassette side coupling standby phase. On the other hand, the main body side coupling 12 maintains the main body side coupling operation end phase shown in FIG.

  As shown in FIG. 6C, the main body side coupling operation end phase is slightly shifted in the reverse direction of the rotational drive with respect to the cassette side coupling standby phase of the cassette side coupling 10, and the main body side A feature of the present invention is that the main body side coupling operation end phase and the cassette side coupling standby phase are selected so that the convex portions of the coupling 12 and the cassette side coupling 12 do not collide.

  In the present embodiment, in order to prevent the convex portions of the main body side coupling 12 and the cassette side coupling 12 from colliding with each other, the gear ratio between the cassette side coupling 12 and the lifter gear 9 is set appropriately, thereby It avoids the bump collision of the coupling pair.

As described above, the main body side coupling operation end phase is slightly shifted in the reverse direction of the rotational drive with respect to the cassette side coupling standby phase of the cassette side coupling 10, and the main body side coupling 12 and the cassette By selecting the main body side coupling operation end phase and the cassette side coupling standby phase so that the convex part of the side coupling 12 does not collide,
When the cassette 3 is mounted on the main body, the cassette side coupling 10 and the main body side coupling 12 are slightly out of phase in the reverse direction of the rotational drive, and the cassette lifter motor 11 rotates to rotate the main body side. When the coupling 12 rotates, it engages with the cassette-side coupling 10 with a slight rotation, and drive transmission is possible. Therefore, in the conventional coupling pair, the main body-side coupling is idled until drive transmission is possible. There is no problem and quick drive transmission is possible.
-Since it is possible to prevent the collision of the convex part between the cassette side coupling 10 and the main body side coupling 12 without the need for detection means such as sensors or control means for the drive motor, it is possible to add sensors as described in the conventional example. It is unnecessary and can provide a cheaper and smaller coupling pair.

  In the present embodiment, the engagement between the cassette side coupling 10 and the main body side coupling 12 depends on the engagement of the convex portions provided in the respective couplings, but may be a combination of the convex portions and the concave portions.

The schematic front view which showed the apparatus to which embodiment of this invention is applied Schematic perspective view showing a cassette to which the embodiment is applied The perspective view which shows embodiment The perspective view which shows embodiment The perspective view which shows embodiment Schematic front view showing an embodiment Figure showing a conventional example

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Image forming apparatus 2 Paper feeding apparatus 3 Cassette 4 Paper feeding part 5 Image forming part 6 Fixing device 7 Discharge port 8 Middle plate 9 Lifter gear 10 Cassette side coupling 11 Cassette lifter motor 12 Main body side coupling 13 Energizing spring S Sheet

Claims (3)

A drive-side coupling provided in the apparatus main body, and a driven body having a driven-side coupling coupled to the drive-side coupling and configured to be detachable from the apparatus main body. Is a drive coupling mechanism that has a plurality of recesses and projections extending in the axial direction and adjacent to each other in the circumferential direction,
When the driven body is pulled out from the main body, the driven side coupling is set to a fixed standby phase, and the phase at the end of driving of the driving side coupling is the standby phase of the driven side coupling. And the fixed relationship is a drive angle characterized in that the driven side coupling is a phase angle at which the tip of the convex part does not collide with the tip of the convex part of the driving side coupling. mechanism. The coupling pair according to claim 1 is applied to drive transmission of the sheet lifting / lowering means of the sheet storage portion in the sheet storage device, and when the sheet storage portion is taken out from the sheet storage device, the sheet lifting / lowering means has its own weight. In the seat lifting device located at a predetermined standby position by a spring or the like,
The seat elevating device according to claim 1, wherein the driven side coupling is directly connected to the seat elevating means, thereby having a standby phase determined when the seat elevating means reaches a predetermined standby position.   An image forming apparatus comprising: a sheet forming unit that forms an image on a sheet fed from a sheet storage unit including the sheet lifting and lowering unit according to claim 2.

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