JP3520850B2 - Image forming device - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to the structure of an electrophotographic image forming apparatus. More specifically, in the image forming apparatus having a detachable process cartridge, a technique for reliably connecting a drive portion to the process cartridge while holding the rotation axis of the photosensitive drum inside the process cartridge at an accurate position. Regarding

[0002]

2. Description of the Related Art In an electrophotographic image forming apparatus, an electrostatic latent image is formed by selectively exposing a photosensitive drum uniformly charged by a charging means in accordance with image information. . A toner image is formed on the electrostatic latent image by the developing device, and the toner image is transferred and recorded on the paper by the transfer device. It is known that the photosensitive drum and the process means acting on the photosensitive drum are integrated into a cartridge and the cartridge can be attached to and detached from the image forming apparatus. This configuration has excellent maintainability, and even if the toner runs low or the photosensitive drum part fails, it can be used normally again by replacing it with a new cartridge, so that you can perform maintenance yourself. This is advantageous in that it is not necessary to call a person who is specialized in repair service.

For example, a drive output gear for driving a process cartridge is supported on the apparatus main body side, while a process input cartridge has a structure in which a drive input shaft is projected on a side surface facing the drive output gear. . In this structure, the axes of the two are aligned with each other, a coupling is formed on the drive output gear, and the drive output gear is slidable in the axial direction and is engaged with the drive input shaft via the coupling. It is detachable, and the drive part is connected / disconnected in this part. According to this, at the time of maintenance, it is possible to release the connection state of the drive portion to the process cartridge and remove the process cartridge. On the other hand, when the process cartridge is set, the drive portion is connected to the photosensitive drum or the like. Can be driven.

[0004]

In such a structure, due to an error in assembling, the axes of the drive input shaft and the drive output gear may not be aligned with each other and may be attached with a deviation. In this case, if they are forcedly engaged with each other via the coupling, the coupling is pryed and damaged,
There is a risk that the connection may not be possible. Further, by engaging the drive input shaft and the drive output gear whose shaft centers are displaced from each other, an unreasonable radial force acts on the tip of the drive input shaft, and the shaft center of the drive input shaft is displaced. There is a risk of tilting. In this case, for example, when the drive input shaft is arranged on the rotation axis of the photoconductor drum, the axis of the photoconductor drum shifts to cause eccentric rotation, which deteriorates the quality of the image formed.

[0005]

The problem to be solved by the present invention is as described above, and the means for solving this problem will be described below.

That is, in the present invention, the process cartridge is detachably provided in the main body of the image forming apparatus, and the drive output gear is supported on the main body side concentrically with the drive input shaft of the process cartridge. In the image forming apparatus in which the drive output shaft is engaged with and disengaged from the drive input shaft via a coupling, the drive output gear includes a first bearing on a side far from the drive input shaft. And a second bearing on the side closer to the drive input shaft, and the drive output gear is engaged by the coupling and the first bearing when engaged with the drive input shaft. It is to be positioned.

In the present invention, the first bearing and the second bearing are configured to allow the drive output gear to move in the axial direction. In claim 3, the drive output gear is allowed to tilt in its axis.
While being supported by the first bearing and the second bearing
It is what

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION Next, embodiments of the present invention will be described. FIG. 1 is a perspective view showing the overall configuration of a copy / facsimile multifunction peripheral according to an embodiment of the present invention. 2 is a perspective view showing a state in which the front side of the reading unit is pulled up and rotated to remove a paper jam, FIG. 3 is a perspective view showing a state in which the top cover is rotated and opened, and FIG. 4 is a cartridge removed. FIG. 5 is a perspective view showing a state, and FIG. 5 is a perspective view showing a state of pulling out and removing a jammed sheet.

[Overall Configuration] FIG. 1 shows a copying / facsimile multifunction peripheral according to an embodiment of the present invention. This multifunction peripheral is configured by arranging a reading unit 3 above an image forming apparatus 2. There is.

The reading unit 3 is used as a flat bed type scanner that scans a reading device provided in the reading / placing table 6 to read a stationary document or the like, and also fixes the reading device in position to fix the document pressing cover. It is also configured so that it can be used as a sheet-feed type scanner which reads an original while feeding the original by an automatic document feeder (ADF) attached to one end of 7.

A sheet feeding device 1 is arranged below the image forming apparatus 2, and a plurality of sheet feeding cassettes 1 constituting the sheet feeding device 1 are arranged.
Recording sheets of different sizes are accumulated and stored in sheets 0 and 10, and the sheet can be fed from one of the sheet feeding cassettes and fed to the image forming apparatus 2 according to the required sheet size. is doing.

The image forming apparatus 2 is the same as that in a usual electrophotographic copying machine, and a sheet conveying path for conveying the sheet fed from the sheet feeding apparatus 1 is formed,
A transport roller, a photosensitive drum, a transfer device, and a fixing device are arranged in the middle of the paper transport path. The photoconductor drum is uniformly charged by the charging means, and thereafter, the photosensitive drum is selectively exposed according to the image information read by the reading unit 3 (or the image information received from the facsimile of the other party), and the electrostatic latent image is formed. An image is formed. A toner image is formed on the electrostatic latent image by the developing device, and the toner image is transferred and recorded on the paper by the transfer device. The paper sheet that has passed through the transfer device is sent to a fixing device, the toner is heat-fused by the fixing device, the image is fixed, and the image forming process is completed. After that, the sheet is sent to the upper surface of the image forming apparatus 2, discharged to the discharge tray 5, and accumulated.

Of the group of devices forming the image forming apparatus 2, the photosensitive drum and the process means acting on the photosensitive drum (that is,
The charging unit, the exposing unit, the developing unit, etc. are integrated into a process cartridge (hereinafter referred to as “cartridge”), and this cartridge is configured to be detachable from the image forming apparatus for the convenience of maintenance. For example, FIG. 2 to FIG. 5 show a procedure for removing a sheet when a sheet jam occurs in the sheet conveying path of the image forming apparatus 2, and in accordance with this, the reading and placing table 6 will be described. The handle 6a is provided as shown in FIG. 2, and the top cover 8 of the image forming apparatus 2 appears by pulling the handle 6a and lifting the front side of the reading and placing table 6 to rotate the handle upward. The top cover 8 is configured to be rotatable and openable via a fulcrum on the back side, and the cartridge 9 and the fixing device 11 inside the image forming apparatus 2 are opened by opening the top cover 8 as shown in FIG. Etc. are exposed. By grasping the gripping portion 9a formed on the upper surface of the cartridge 9 and pulling it up as shown in FIG. 4, the cartridge 9 can be removed and the paper transport path can be exposed. The paper jam condition is cleared by pulling out the folded paper as shown in FIG.

[Drive Unit] As shown in FIG. 5, a drive unit 12 is supported on one side of the image forming apparatus 2,
Power from the drive unit 12 is transmitted to the cartridge 9, the fixing device 11 and the like for driving. The drive unit 12 will be described below. FIG. 6 is an overall side view of the drive unit.

The overall structure of the drive unit 12 is shown in FIG. 6. The drive unit 12 has a frame body 13 as a frame made of sheet metal, and one side surface of the frame body 13 has a motor 14 as a drive source. Is attached in a cantilever manner, and a large number of gear trains for transmitting the power of the motor 14 are supported by the frame body 13. Two drive output parts, that is, a fixing device drive output part 15 and a cartridge drive output part 16 are arranged on the upper portion of the frame body 13.
The driving force of the motor 14 is constantly transmitted to the motor through the gear train.

[Fixer Driving Output Unit] The fixing device driving output unit 15 will be described. FIG. 7 is a plan sectional view showing the structure of the fixing device drive output section of the drive unit.

A fixing device drive input gear 17 for receiving a driving force for the fixing device 11 is disposed on the fixing device drive output section 15, and the driving force is connected to and disconnected from the fixing device drive input gear 17. The fixing device drive output unit 15 is configured so as to be capable. Specifically, the sun gear 1 supported by the frame 13 and interlockingly connected with the motor 14 via a gear train.
8, a swing arm (second frame) 19 pivotally supported by the frame 13 so as to be vertically swingable about the same axis as the axis of the sun gear 18, and the swing arm 1
9 and a planetary gear 20 that is a drive gear and is constantly meshed with the sun gear 18. With this configuration, when the swing arm 19 rotates upward, the planetary gear 20 engages with the fixing device drive input gear 17 and is in a state in which power can be transmitted. When the swing arm 19 rotates downward, the engagement is released and power transmission is cut off.

Now, a structure for smoothly swinging the swing arm 19 up and down will be described. That is,
In the drive unit 12 of this embodiment, the sun gear shaft 21 is supported between the frame bodies 13, and the sun gear 18 is rotatably arranged on the sun gear shaft 21. As shown in FIG. 7, the swing arm 19 is formed by bending a sheet metal into a "U" shape in plan view (frame shape) so that both ends thereof face the same side, and the both ends respectively turn bases 19a and 19a. As described above, the swing arm 19 is supported so as to be swingable about the sun gear shaft 21, as described above. The rotating base 19a-1
The outer surface of 9a is close to the inner surface of the frame body 13, respectively. The sun gear shaft 2 is provided inside the swing arm 19.
1, the planetary gear shaft 22 is supported in parallel, and the planetary gear 20 is supported on the planetary gear shaft 22 and is rotatable. Even when the swing arm 19 swings, the distance between the two gear shafts 21 and 22 is constant, and the two gears 18 and 20 do not move.
The meshing state of is always maintained.

In the structure described above, a plurality of small projections 23, 23 are formed on the outer surface of the rotation bases 19a, 19a of the swing arm 19 (FIGS. 6 and 7), and the tips of the projections 23 are formed. The swing arm 19 is adapted to rotate while being in contact with the inner surface of the frame body 13. That is, if such a protrusion 23 is not formed, both the frame 13 and the swing arm 19 are made of sheet metal. Therefore, when the swing arm 19 is tried to rotate, the sheet metals rub against each other and become different from each other. Sound may be generated or it may get caught and may not operate smoothly. In this respect, in the present embodiment, the frame 1
3. Since the swing arm 19 is in contact with each other, the sheet metals do not rub against each other, so that the generation of abnormal noise is suppressed, catching is prevented, and the rocking motion is highly reliable. Therefore, it is not necessary to perform secondary processing such as deburring of sheet metal, which contributes to cost reduction.

The protrusion 23 is not limited to being provided on the swing arm 19, but the same effect can be obtained by providing the protrusion on the inner surface side of the frame body 13 and contacting the tip thereof with the outer surface of the swing arm 19. You can That is, by forming a protrusion on either the frame 13 or the swing arm 19 in the portion of the surface where the frame 13 and the swing arm 19 face each other, the above-mentioned abnormal noise is prevented and smooth operation is achieved. It is possible. The shape of each of the protrusions 23 is not limited, and any shape may be used as long as the area where the frame body 13 and the swing arm 19 are in contact with each other can be reduced. Therefore, it is sufficient if it is formed in a protruding shape (projecting portion). However, from the viewpoint of more effectively suppressing the generation of abnormal noise when swinging the swing arm 19 and reliably preventing the operation from being caught, the protrusions 23 as in the present embodiment.
It is desirable to form 23 into a small rounded shape so that both 13 and 19 rub at one point. In the present embodiment, as shown in FIG.
The number of the protrusions 23 formed on the outer surface of the a is three, and the protrusions 23 are formed at equal intervals on the circumference around the sun gear shaft 21. However, this is not a limitation, either.
For example, a structure having four or more protrusions may be used.

[Cartridge Drive Output Unit] The cartridge drive output unit 16 will be described. FIG. 8 is a sectional view taken along the line AA in FIG. 6 showing the fixing device driving output portion, and FIG. 9 is a fixing device driving output portion in which there is an axial deviation between the driving output gear and the driving input shaft of the cartridge. FIG. 10 is a cross-sectional view showing a certain case, and FIG. 10 is a cross-sectional view showing a state where the axis line of the drive output gear is tilted from the state of FIG. 9 and engages with the drive input shaft of the cartridge.

As shown in FIG. 6, the drive output gear 24 is provided at a position adjacent to the fixing device drive output section 15 so that the frame 1
3, the driving output gear 24 is constantly transmitted with power from the motor 14 via the gear train. The mounting position of the drive output gear 24 is shown in FIG.
As shown in FIG. 8, it is arranged concentrically with the drive input shaft 25 as a driven member that receives the driving force for the cartridge 9. As shown in FIG. 8, the drive input shaft 25 is arranged at the rotation axis of the photosensitive drum 39 housed in the cartridge 9 and has one end protruding from the side surface of the cartridge 9. An annular guide 40 is attached to the side surface of the cartridge 9 around the protruding portion of the drive input shaft 25. The drive output gear 24 is formed as a shaft-integrated type in which support shafts 24b and 24c are projected from both side surfaces of the drive output gear 24. The support shaft 24b on the side far from the cartridge 9 is attached to a cylindrical first bearing 41 and the cartridge 9 is attached. 24 on the side close to
c are respectively supported by the second bearings 42. The second bearing 42 is formed in a guide cover 43 mounted on the outer surface of the frame body 13 facing the cartridge 9 side, and the guide cover 43 is an oblique guide into which the annular guide 40 is inserted. The groove 43a is integrally formed (FIGS. 6 and 8), and the second bearing 42 is positioned at the end (lower end) of the guide groove 43a. With this configuration, the annular guide 40 of the cartridge 9 is inserted into the guide groove 43a and slid along the guide groove 43a, so that the cartridge 9 can be set while being guided to an accurate position. It can be easily removed.

At the end of the support shaft 24c of the drive output gear 24, a coupling portion 24a is formed which can be engaged with and disengaged from the drive input shaft 25 of the cartridge 9. Both the first bearing 41 and the second bearing 42 are configured as sliding bearings, and support shafts 24b and 24c of the drive output gear 24 are provided.
Not only the sliding rotation but also the slide movement in the thrust direction is possible, and the drive input shaft 25 of the cartridge 9 and the coupling portion 24a are engaged and disengaged by the movement in the thrust direction.

Here, the support structure of the drive output gear 24 will be described. That is, the drive output gear 24 is arranged on the same axis as the drive input shaft 25 on the cartridge 9 side as described above, but the axes of both members 24, 25 can be attached with a deviation due to an assembly error or the like. In this case, if the shaft misaligned members 24 and 25 are engaged as they are, the coupling portion 24a is twisted and damaged, and rotation cannot be transmitted.
Is forcedly connected, a strong radial force acts on the end portion of the drive input shaft 25 to tilt or shift the rotation axis thereof, which causes eccentric rotation of the photoconductor drum 39, and There was a risk that the quality would deteriorate. In this respect, in the present embodiment, the shaft hole of the second bearing 42 is made slightly larger to secure a small clearance with the supported support shaft 24c and to allow a small inclination of the axis. Drive output gear 2 with two bearings 41 and 42
4 is supported. In other words, the second bearing 42 only gently supports the support shaft 24c and does not perform strict positioning. Instead, the drive output gear 24 is provided with the drive input shaft 25 when the drive output gear 24 is engaged with the drive input shaft 25. The positioning is performed by the coupling portion 24a and the first bearing 41.

As a result, for example, as shown in FIG. 9, even when the drive output gear 24 is attached to the drive input shaft 25 with the axis deviated by the distance s, the shaft center of the drive output gear 24 at the time of engagement. Is inclined within a range allowed by the clearance c of the second bearing 42 as shown in FIG. 10, and the axial deviation s is absorbed. Therefore, the drive output gear 2 is not forcedly applied to the drive input shaft 25.
4 can be connected, and damage to the coupling portion 24a and misalignment of the photosensitive drum 39 can be prevented.

[Coupling Structure of Both Output Units] Next, a linking structure of the fixing device drive output unit 15 and the cartridge drive output unit 16 will be described. That is, the swing arm 19 of the fixing device drive output unit 15 and the cartridge drive output unit 16
The drive output gear 24 of the cartridge 9 is linked by a cam mechanism described below, and when the fixing device drive output portion 15 is disconnected from the fixing device drive input gear 17, the cartridge driving output portion 16 of the cartridge 9 is released. Drive input shaft 25
It is configured to release the connection with. FIG. 11 is a cross-sectional view showing the configuration of a cam mechanism that pushes the side surface of the drive output gear to move the drive output gear in the axial direction.
FIG. 13 is also a perspective view, and FIG. 13 is a perspective view showing a state in which the swing arm rotates downward from the state of FIG. 12 and the push cam pushes the side surface of the drive output gear.

The cam mechanism 27 will be described. 6 and 1
As shown in FIG. 1 and FIG. 12, a pin 37 is projectingly provided on the free end side of the swing arm 19 and is brought close to the free end side of the swing arm 19, and a plate-like push cam as a push member. 26 is erected with its lower end pivotally supported.
The side edge portion on one side is close to the one side surface of the drive output gear 24. As shown in FIGS. 11 and 12, the rotary cam 26 is provided with an oblique slender cam groove 26a, and the tip of the pin 37 is inserted into the cam groove 26a. On the other hand, a biasing spring 38 is interposed between the other side surface of the drive output gear 24 and the frame 13 in a contracted state (FIG. 11).
The biasing spring 38 constantly applies a biasing force in a direction in which the drive output gear 24 is engaged with the drive input shaft 25.
As shown in FIG. 12, on the side surface of the drive output gear 24 near the push cam 26, reinforcing ribs 24d are formed in an annular shape along the circumferential direction. The reinforcing rib 24d
The head of the is opposed to the side edge of the pushing cam 26. Therefore, when the swing arm 19 rotates downward from the state shown in FIG. 12, the pin 3 is rotated as shown in FIG.
7 moves downward in the cam groove 26a, and the cam groove 26a
The pushing cam 26 falls due to the cam action of a, and the side edge portion thereof comes into contact with the reinforcing rib 24d and the drive output gear 24
Push. The drive output gear 24 moves in the axial direction against the urging force of the urging spring 38, and the connected state with the drive input shaft 25 is released. With the configuration of the cam mechanism described above, when the swing arm 19 is rotated downward to release the connection between the fixing device drive input gear 17 and the planetary gear 20, the drive output gear 24 and the drive input shaft 25 are also moved together with the swing arm 19. The connection with is released.

When the force for rotating the swing arm 19 downward is released, the urging spring 38 pushes the side surface of the drive output gear 24 to project the coupling portion 24a and the drive input shaft 25. Connect with. At this time, the drive output gear 24 pushes the pushing cam 26 through the reinforcing rib 24d to raise the pushing cam 26.
An upward force is applied to the pin 37 by the cam action of a, and the swing arm 19 is rotated upward. That is, the urging spring 38 also serves as a return spring that returns the downward rotation of the swing arm 19. Therefore, in the cam mechanism 27 described later, when the cam 30 does not push the pushing surface of the swing arm 19 downward,
The swing arm 19 rotates upward, and the supported planetary gear 20 engages with the fixing device drive input gear 17.

As described above, the drive output gear 24 is formed with the reinforcing rib 24d in an annular shape along the circumferential direction, and when the pushing cam 26 is tilted to push the drive output gear 24, the pushing rib 26d is pushed. The moving cam 26 contacts the reinforcing rib 24d and pushes it. That is, in the structure in which such a reinforcing rib 24d is not provisionally provided and the pushing cam 26 directly contacts the side surface of the drive output gear 24 and pushes,
There is a risk of damaging and damaging the drive output gear 24 when the push cam 2 is pushed.
If the portion where 6 comes into contact is a portion close to the tooth surface of the drive output gear 24, the tooth surface will be scratched or dented, and good meshing with other gears will not be obtained, resulting in smooth drive transmission. There is a strong possibility that it will not be done. From this point of view, in the present embodiment, by providing the reinforcing rib 24d at the portion of the drive output gear 24 that comes into contact with the push cam 26, the drive output gear 24 (particularly, its tooth surface) is as described above. By preventing scratches and pits from being formed, it is possible to prevent the quality of the recorded image quality from deteriorating due to image distortion due to uneven rotation.

Further, since the reinforcing ribs 24d are formed along the circumferential direction, the pushing cam 26 is always in contact with the pushing cam 26 regardless of the rotation phase of the drive output gear 24 when the pushing cam 26 falls. It is ensured that the drive output gear 24 is pressed against the reinforcing rib 24d via the reinforcing rib 24d. Therefore, it is possible to reliably prevent the drive output gear 24 from being scratched or dented. In the present embodiment, the reinforcing rib 24d has a trapezoidal cross section as shown in FIG. 11, but the shape is not limited to this, and may be, for example, an arc shape.

[Drive transmission / open / close according to opening / closing of the top cover]
Configuration for Canceling Transmission] Next, the cam mechanism 27 that connects the top cover 8 and the swing arm 19 of the fixing device drive output unit 15 will be described. That is, the swing mechanism 19 and the top cover 8 will be described below with respect to the cam mechanism 2
When the top cover 8 is closed, the swing arm 19 is pivoted upward to connect the fixing device driving output portion 15 to the fixing device driving input gear 17 and the cartridge. 9 drive input shaft 25
The cartridge drive output unit 16 is connected to the fixing device 11 and the cartridge 9 are driven. On the other hand, when the top cover 8 is rotated upward to open for accessing the inside of the image forming apparatus 2 such as clearing a paper jam, the swing arm 19 is rotated downward to fix the fixing device drive input gear 17. The fixing device drive output unit 15 is disconnected from the fixing unit 11 to free the rotation of the roller of the fixing unit 11, and the cartridge driving output unit 16 is disconnected from the drive input shaft 25 of the cartridge 9 to remove the cartridge 9. Thus, the jammed paper can be easily removed. 14
FIG. 6 is a side view showing a cam mechanism that links a top cover and a swing arm.

The cam mechanism 27 shown in FIG. 14 is arranged at a position sandwiched by the top cover 8 rotatably and rotatably via a fulcrum 44 and the drive unit 12 from above and below. . The cam mechanism 27 has a lever 29 that has a pin 28 that is a convex body provided on the top cover 8 and a hook portion 29a that can be engaged with the pin 28 at the upper end.
And a cam 30 whose one end is pivotally connected to the lower end of the lever 29. As shown in FIG. 14, the pin 28 has a bracket 8a integrally formed on the ceiling surface of the top cover 8 (the surface facing the inside of the image forming apparatus 2) and hangs down.
It is provided integrally with the lower end of a. The pin 2
8 is the lever 29 when the top cover 8 is closed.
It is located inside the hook portion 29a, and is configured so that the lever 29 can be pulled up through the hook portion 29a as the top cover 8 rotates upward. The upper end of the lever 29 is hook-shaped on the front side of the device and serves as the hook portion 29a, which is detachable from the top cover 8 via the pin 28. On the back side of the lever 29 in the device, an opening 29e is formed to open upward.

The lever 29 is arranged in the up-down direction, and a long hole 29b is not provided at a middle portion in the longitudinal direction thereof, and the support pin 33 provided on the main body of the image forming apparatus 2 is inserted into the long hole to make it It supports the lever 29. The lever 29 can be vertically moved and tilted within a certain range while being guided by the elongated hole 29b.
A wide play portion 29c is provided on the lower side of the long hole 29b, and when the lever 29 moves upward as described later, the support pin 33 enters the play portion 29c, so that the lever 29 moves. Lower end (cam 3
It is designed so that it can be rotated about its center (a joint with 0).

Two urging springs 31 and 32 are interposed between the lever 29 and the main body of the image forming apparatus 2. The first urging spring 31 moves the lever 29 to the front side of the apparatus and the second urging spring. The biasing spring 32 applies a biasing force that pulls the lever 29 in a substantially downward direction. The stopper 34 is provided in the main body of the image forming apparatus 2.
Is provided, and the lever 29, which receives the biasing force of the first biasing spring 31, brings its side edge into contact with the stopper 34, thereby restricting further tilting of the lever 29 in the front direction of the device. ing. A concave portion 29d is provided on a side edge of the lever 29 that comes into contact with the stopper 34, and when the lever 29 moves upward, the lever 29 can be tilted so that the stopper 34 is inserted into the concave portion 29d. It is like this.

The hook portion 29a at the upper end of the lever 29 has a bottom portion 35 which is inclined with respect to the longitudinal direction of the lever 29.
When the top cover 8 is closed, the pin 28 abuts on the bottom portion 35, and the lever 2 slides while sliding.
9 is configured to be able to be pushed in a direction against the tension of the first biasing spring 31.

A cam 30 is pivotally supported by the main body of the image forming apparatus 2 in the middle of the swing arm 19 of the drive unit 12 like a seesaw, and one end of the cam 30 is the lower end of the lever 29. Is linked to. The swing arm 19 has a flat pushing surface 19b.
As shown in FIGS. 12 and 13, the other end of the cam 30 is brought into contact with the pushing surface 19b to push downward or release the pushing. Is configured as follows.

How the swing arm 19 is actually linked according to the opening / closing operation of the top cover 8 in the above-mentioned structure will be described. FIG. 15 is a side view showing a state in which the top cover is pulled up and opened from the state of FIG. 14, and the pin rotates the cam via the lever to push the swing arm downward. FIG. 16 shows the lever tilting. FIG. 11 is a side view showing a state in which the recess is engaged with the positioning pin, the swing arm is pushed downward and locked, and the pin is disengaged from the hook portion. On the other hand, FIG. 17 is a side view showing a state in which the open top cover is pulled down and the pin comes into contact with the bottom portion of the hook portion of the lever. FIG. 18 shows the pin pushing the bottom portion of the hook portion of the lever to tilt the lever. FIG. 19 is a side view showing a state, and FIG. 19 is a diagram showing a state in which the recess of the lever and the positioning pin are disengaged, the lever is pulled down, and the downward pushing motion of the swing arm is released. FIG. 20 is a table showing the relationship between the state of the top cover and the drive connection state.

First, the operation of opening the top cover 8 will be described. In the state shown in FIG. 14, the top cover 8 is closed, the pin 28 is inside the hook portion 29a of the lever 29, and the lever 29 is pulled downward by the second biasing spring 32. It is at the lower end position defined by the long hole 29b and the support pin 33. Further, the lever 29 is pulled toward the front side of the apparatus by a first biasing spring 31, and its side edge portion is brought into contact with the stopper 34 to be stationary. Since the cam 30 is pulled down on the pivotal side of the lever 29, the other side is pulled up and is not in contact with the pushing surface 19b of the swing arm 19. The swing arm 19, which is biased upward by the biasing spring 38 (FIG. 11) as described above, rotates upward to engage the supporting planetary gear 20 with the fuser drive input gear 17. The power from the motor 14 can be transmitted to the fixing device 11. The drive output gear 24 that is interlocked with the swing arm 19 via the push cam 26 and the like is in the state shown in FIG. 12 in which it is engaged with the drive input shaft 25 of the cartridge 9.

From this state, when the top cover 8 is rotated upward as shown by the chain line in FIG.
Comes into contact with the hook portion 29a of the lever 29. When the top cover 8 is further pulled up, as shown in FIG.
The pin 28 pulls up the hook portion 29a of the lever 29, and the lever 29 moves upward while being guided by the long hole 29b and the support pin 33. The cam 30 whose one end is pulled up by the lower end of the lever 29, lowers the other end,
The pushing surface 19b of the swing arm 19 is contacted and pushed,
The swing arm 19 is rotated downward. Therefore, the planetary gear 20 supported by the swing arm 19 moves downward to be disengaged from the fixing device drive input gear 17, and is also interlocked with the swing arm 19 via the push cam 26 or the like. The drive output gear 24 for the cartridge 9
13 is released from the drive input shaft 25, and the state of FIG. 13 is entered.

When the lever 29 is pulled up by a certain amount, the recess 29d formed in the lever 29 also moves upward to reach the height of the stopper 34, and at the same time, the support pin 33 is lengthened. Since the lever 29 enters the play portion 29c at the lower end of the hole 29b, the lever 29 is in a state where its upper portion can be tilted toward the front side of the apparatus. FIG. 15 shows a state immediately before the start of tilting. Immediately after this, the lever 29 is pulled by the tension of the first biasing spring 31.
16 is tilted toward the front side of the apparatus about its lower end (a portion connected to the cam 30), and the stopper 34 is inserted into the recess 29d, as shown in FIG.

When the tilting of the lever 29 is completed, the stopper 34
The state in which the recess 29d and the recess 29d are engaged is a locked state in which the lever 29 cannot move up and down,
Therefore, the cam 30 is maintained in a state of pushing the swing arm 19 downward. On the other hand, when the lever 29 tilts, the hook portion 29a at the upper end of the lever 29 releases the engagement with the pin 28 of the top cover 8 and the pin 2
The opening 29e is located at 8. Therefore, since the pin 28 can be removed from the inside of the hook portion 29a, the top cover 8 can be rotated upward to its limit. With this configuration, the top cover 8 can be largely opened, access to the inside of the image forming apparatus 2 is facilitated, and maintainability is improved.

Next, the operation of closing the top cover 8 in reverse will be described. FIG. 17 shows a state in which the top cover 8 is opened, and when the top cover 8 is pulled down and closed from this state, the pin 28 moves to the lever 2
9 enters the inside of the hook portion 29a through the opening portion 29e at the upper end and abuts on the slanted bottom portion 35 as shown by a chain line. The bottom portion 35 is formed by the pin 2 associated with the opening / closing operation of the top cover 8.
Since the pin 28 is slanted with respect to the locus of FIG.
As shown in, the bottom portion 35 is pushed toward the back side of the apparatus.
As a result, the lever 29 tilts so as to move the upper part toward the rear side of the device with its lower end substantially centered, while resisting the tension of the first biasing spring 31. With the tilting of the lever 29, the recess 29d formed on the side edge is provided with the stopper 34
To disengage. FIG. 18 shows a state immediately before the release of the engagement is completed. Immediately after this, the lever 29 pulled downward by the second biasing spring 32 is attached to the elongated hole 29b and the support pin 33. It moves downward while being guided, and finally the support pin 33 comes to rest in the state of FIG. 19 in which it abuts on the upper end of the long hole 29b.

Since one end of the cam 30 is pulled down by the descending lever 29, the other end is pulled up, and the downward pushing motion of the swing arm 19 is released. Therefore, the swing arm 19 is pulled up by the action of the return spring 38, the supporting planetary gear 20 is meshed with the fixing device drive input gear 17, and the swing arm 1
Drive output gear 24 that is linked to 9 via a push cam 26
Are engaged with the drive input shaft 25 of the cartridge 9.

The operation of the cam mechanism 27 corresponding to the opening operation and the closing operation of the top cover 8 has been described above. As a result, as shown in the table of FIG. The gear 17 and the planetary gear 20 are disengaged from each other so that the rollers forming the fixing device 11 can be rotated freely to facilitate the removal of jammed paper during maintenance.・ 2
The fixing device 11 is driven by meshing 0. Further, when the top cover 8 is opened, the drive input shaft 25 of the cartridge 9 and the drive output gear 24 are disconnected from each other, and the cartridge 9 can be detached to improve maintainability, while the top cover 8 is closed. Then, both 25 and 24 are connected to drive the photosensitive drum 39 and the like in the cartridge 9.

Further, by configuring the cam mechanism 27 as described above, the force acts on the pin 28 of the top cover 8 when the opening operation of the top cover 8 is shown by the chain line in FIG. From the state to the state of FIG. 15, from the state shown by the chain line in FIG. 17 to the state of FIG. 18 in the closing operation, otherwise the force does not act on the pin 28. There is. That is, the top cover 8
The pin 28 in the open and closed positions.
Is not applied at all, and the force is applied only during a part of the opening / closing operation of the top cover 8. Therefore, the required strength of the pin 28 is weaker than the conventional one. In this embodiment, the pin 28
Is integrally formed with the plastic top cover 8 and does not have a reinforcing structure for improving the strength thereof, thereby reducing the manufacturing cost.

[Mounting Configuration of Driving Unit to Image Forming Apparatus] Finally, the image forming apparatus 2 of the driving unit 12 is attached.
The mounting configuration for will be described. 21 is a perspective view showing a method of assembling the drive unit to the image forming apparatus, FIG.
2 is a perspective view showing a state in which the motor of the drive unit is received in the through hole of the main body frame.

That is, the drive unit 12 is as described above.
The motor 14 is attached to the frame 13 (as a bracket).
In general, the motor 14 is a heavy object and occupies most of the weight of the entire drive unit 12. Further, in this embodiment, the drive unit 12 is a heavy load motor 14 as shown in FIG.
Is attached to the frame body 13 while supporting it in a cantilever manner. Since the center of gravity is biased and the balance is unbalanced, it is not easy to set it upright. On the other hand, drive unit 1
2 needs to be attached to the body frame 45 on the side of the image forming apparatus 2 in an upright state, and if it is left as it is, it will be difficult to assemble the image forming apparatus 2.

Under such circumstances, in this embodiment, the body frame 45 of the image forming apparatus 2 made of sheet metal is provided with the rectangular through hole 46 for mounting the motor 14, and the through hole 4 is formed.
Around the 6 (specifically, both sides and the bottom), the motor 1
A guide 47 for a plate-like object to be placed along the side surface or the bottom surface of No. 4
・ 47 ... is provided so as to project inward of the apparatus. With the above configuration, when the drive unit 12 is assembled to the image forming apparatus 2, first, the motor 14 is inserted from the outside of the main body frame 45 into the through hole 46 as shown in FIG. Is placed on the guide 47 on the bottom side so that the body frame 45 receives the weight of the motor 14 itself. Thereby, the drive unit 12 can be easily held in the upright state. In this embodiment, the motor 14 is moved from the state shown in FIG.
The frame 1 of the drive unit 12 so as to slide along
3 is attached to the main body frame 45, and both 13 and 45 are fixed by screws (not shown). Since such an easy assembling method can be adopted, the number of assembling steps can be reduced.

The guide 47 is constructed by punching the through hole 46 of the main body frame 45 while leaving the guide portion, and then bending the guide portion inward of the image forming apparatus 2. . This contributes to the compactness of the device by reducing the portion protruding to the outside of the device, and the direction in which the guide 47 is bent and the direction in which the motor 14 is inserted at the time of assembly match, so that the motor 14 can be smoothly moved. It can be inserted along the guide 47. Further, the through hole 46 is formed in a rectangular shape, and the guide 47 is formed in a flat plate shape so as to follow the shape of the casing of the motor 14 which is a substantially rectangular parallelepiped.

[0050]

Since the present invention is constructed as described above,
The following effects are achieved.

That is, as described in claim 1, the process cartridge is detachably provided in the image forming apparatus main body, and the drive output gear is supported on the main body side concentrically with the drive input shaft of the process cartridge. In the image forming apparatus in which the gear is slid in the axial direction to be engaged with and disengaged from the drive input shaft through the coupling, the drive output gear is provided on the side farther from the drive input shaft. A bearing and a second bearing on the side closer to the drive input shaft, and when the drive output gear is engaged with the drive input shaft, the coupling and the first bearing Even if there is an axial deviation between the drive output gear and the drive input shaft due to an assembly error, etc. Since the positioning by the receiving is performed, the drive output gear becomes possible to engage to appropriately inclined drive input shaft axis as required, connecting the drive portion is performed smoothly. Therefore, an unreasonable force acts on the coupling to damage it, or a strong force is applied to the end portion of the drive input shaft to cause a shaft center deviation or a shaft center inclination,
The eccentric rotation of the photosensitive drum does not cause deterioration of the quality of the recorded image.

According to a second aspect of the present invention, the first bearing and the second bearing are configured to allow the drive output gear to move in the thrust direction, and the drive output gear is
While allowing the inclination of the axis, the first bearing and the second bearing
Since it is supported by the bearing, together with the two bearings to regulate the movement in the radial direction, so allowing movement of the thrust direction can be carried out smoothly disengaged for driving the input shaft on the same axis . Also, the claims
As shown in Fig. 3, the drive output gear has the inclination of its axis line.
Allowed, but by the first bearing and the second bearing
Because it is supported , force is applied to the drive input shaft.
Drive output gear can be connected without
Prevents damage to the pulling section and misalignment of the photosensitive drum
It will be.

[Brief description of drawings]

FIG. 1 is a perspective view showing an overall configuration of a copy / facsimile multifunction peripheral according to an embodiment of the present invention.

FIG. 2 is a perspective view showing a state in which a front portion of a reading unit is pulled up and rotated to remove a paper jam.

FIG. 3 is a perspective view showing a state in which a top cover is rotated and opened.

FIG. 4 is a perspective view showing how the cartridge is removed.

FIG. 5 is a perspective view showing how a jammed sheet is pulled out and removed.

FIG. 6 is an overall side view of a drive unit.

FIG. 7 is a plan cross-sectional view showing the configuration of a fixing device drive output section of the drive unit.

FIG. 8 is a view of the fixing device drive output unit, which is indicated by A- in FIG.
FIG.

FIG. 9 is a cross-sectional view showing a case where there is an axial deviation between the drive output gear and the drive input shaft of the cartridge in the fixing device drive output section.

FIG. 10 is a cross-sectional view showing a state in which the axis line of the drive output gear tilts from the state of FIG. 9 and engages with the drive input shaft of the cartridge.

FIG. 11 is a cross-sectional view showing the configuration of a cam mechanism that pushes the side surface of the drive output gear to move the drive output gear in the axial direction.

FIG. 12 is a perspective view of the same.

FIG. 13 is a perspective view showing a state where the swing arm rotates downward from the state of FIG. 12 and the push cam pushes the side surface of the drive output gear.

FIG. 14 is a side view showing a cam mechanism that links a top cover and a swing arm.

FIG. 15 is a side view showing a state in which the top cover is pulled up and opened from the state of FIG. 14, and the pin rotates the cam through the lever to push the swing arm downward.

FIG. 16 is a side view showing a state in which the lever is tilted, the concave portion is engaged with the positioning pin, the swing arm is pushed downward and locked, and the pin is disengaged from the hook portion.

FIG. 17 is a side view showing a state in which the open top cover is pulled down and the pin comes into contact with the bottom portion of the hook portion of the lever.

FIG. 18 is a side view showing a state in which the pin pushes the bottom portion of the hook portion of the lever and the lever tilts.

FIG. 19 is a view showing a state in which the engagement between the recessed portion of the lever and the positioning pin is released, the lever is pulled down, and the downward pushing motion of the swing arm is released.

FIG. 20 is a table showing the relationship between the state of the top cover and the drive connection state.

FIG. 21 is a perspective view showing a method of assembling the drive unit to the image forming apparatus.

FIG. 22 is a perspective view showing a state in which the motor of the drive unit is received in the through hole of the main body frame.

[Explanation of symbols]

2 Image forming device 9 Process cartridge 24 Drive output gear 24a Coupling part (coupling) 25 Drive input shaft 41 First bearing 42 Second bearing

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Claims (3)

(57) [Claims] 1. An image forming apparatus having a process cartridge detachably mounted on an apparatus main body, wherein a drive output gear provided on the main body side is supported concentrically with a drive input shaft of the process cartridge, and the drive output gear is a shaft. In the image forming apparatus configured to slide in a direction to engage and disengage with the drive input shaft via a coupling, the drive output gear includes a first bearing on a side far from the drive input shaft, The drive output gear is supported by a second bearing on the side closer to the drive input shaft, and is positioned by the coupling and the first bearing when engaged with the drive input shaft. An image forming apparatus characterized by the above. 2. The image forming apparatus according to claim 1, wherein the first bearing and the second bearing are configured to allow the drive output gear to move in the thrust direction. 3. The drive output gear has an inclination of its axis.
Allowed, but by the first bearing and the second bearing
It is supported, The claim 1 or claim 2 characterized by the above-mentioned.
The image forming apparatus according to item 1.