JP2002040875A - Process cartridge - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce wear of a coupling engagement part between a process cartridge and an image forming device main body, to improve the strength of this part, and to improve the picture quality. SOLUTION: In an axially rectangular section, the contact part of a coupling projecting part 37a of the process cartridge to a coupling recessed part 39a of the device main body forms a curve r2, and the contact part of the projecting part 37a is not twisted in the axial direction. The part on the side opposite to the contact part of the projecting part 37 is twisted, and the root side is made thick, or a large circle r1 of the projecting part 37 is made equal to an inscribed circle of the recessed part 39a.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a process cartridge detachably mountable on a main body of an electrophotographic image forming apparatus. Here, the electrophotographic image forming apparatus forms an image on a recording medium using an electrophotographic image forming method. Examples of the electrophotographic image forming apparatus include, for example, an electrophotographic copying machine, an electrophotographic printer (for example, a laser beam printer, an LED printer, and the like), a facsimile machine, a word processor, and the like.

A process cartridge is a unit in which a charging unit, a developing unit or a cleaning unit and an electrophotographic photosensitive drum are integrally formed into a cartridge, and this cartridge is made detachable from an image forming apparatus main body.
In addition, at least one of the charging unit, the developing unit, and the cleaning unit and the electrophotographic photosensitive drum are integrally formed into a cartridge so that the cartridge can be attached to and detached from the image forming apparatus main body. Further, it means that at least the developing means and the electrophotographic photosensitive drum are integrally formed into a cartridge so as to be detachable from the apparatus main body.

[0003]

2. Description of the Related Art An electrophotographic image forming apparatus using an electrophotographic image forming system forms a latent image by selectively exposing an electrophotographic photosensitive member uniformly charged by a charging means in accordance with image information. I do.

[0004] The latent image is developed by a developing means using toner to form a toner image. Thereafter, the toner image formed on the electrophotographic photosensitive member is transferred to a recording medium by a transfer unit to form an image.

Conventionally, in an image forming apparatus using an electrophotographic image forming process, a drum-shaped electrophotographic photosensitive member and process means acting on the electrophotographic photosensitive member are integrally formed into a cartridge, and this cartridge is used as an image forming apparatus. A process cartridge system that can be attached to and detached from the forming apparatus main body is employed. According to this process cartridge system, the maintenance of the apparatus can be performed by the user himself without relying on a serviceman, so that the operability can be remarkably improved. Therefore, this process cartridge system is widely used in image forming apparatuses.

In such a process cartridge, at least the electrophotographic photosensitive drum is driven. Therefore, when the process cartridge is mounted on the image forming apparatus main body,
A power transmission member connected to a drive source of the image forming apparatus main body and the electrophotographic photosensitive drum are connected.

Here, various methods have been conceived to rotationally drive the electrophotographic photosensitive drum. One method is as described in JP-A-62-65049, in which a pin fixed on the side of a gear provided on the image forming apparatus main body is attached to the side of a gear provided on the photosensitive drum. This is a method in which the photosensitive drum is rotated by being fitted into the provided concave portion.

As another method, as described in Japanese Patent Application Laid-Open No. 63-4252, there is a method of rotating a photosensitive drum by fitting it with a helical gear provided in an image forming apparatus main body.

[0009]

All of the techniques described in the publications described in the description of the prior art are very effective as a configuration for transmitting a rotational force to a photosensitive drum. The present invention is a further development of the prior art described below.

It is an object of a first invention according to the present application to provide a process cartridge capable of reliably transmitting a driving force from an apparatus main body to an electrophotographic photosensitive drum of a process cartridge.

A second object of the present invention is to provide a process cartridge capable of efficiently transmitting a driving force from an apparatus main body to an electrophotographic photosensitive drum of a process cartridge. That is.

A third object of the present invention is to provide a process cartridge capable of obtaining a higher quality image by reducing the fluctuation of the rotation of the photosensitive drum in addition to the above objects.

[0013]

In order to achieve the above-mentioned object, the invention according to the main application of the present invention will be described below with reference to the numbers corresponding to the claims.

According to a first aspect of the present invention, there is provided a drive source, an apparatus body-side drive transmission unit rotationally driven by the drive source, a protruding portion extending in a rotation center axis direction of the drive transmission unit, and An electrophotographic photosensitive drum, a process unit acting on the electrophotographic photosensitive drum, and a process cartridge detachable from an image forming apparatus main body having a connection hole provided on a rotation center axis of the unit. A process cartridge, which is provided integrally with the photoreceptor and is provided with a connection protrusion that is in contact with the connection hole, wherein the contact portion with the connection hole has a connection protrusion having a curved cross-sectional shape. It is.

Since the contact portion has a curved shape, the strength can be increased in shape as compared with the case where the contact portion comes into contact with a corner portion.
The contact part is difficult to break or chip.

A second invention according to the present application is the process according to the first invention, wherein a contact portion of the connection projection with the connection hole has a shape parallel to a rotation center axis direction of the connection hole. It is a cartridge. When transmitting drive,
No thrust force that is unnecessary for rotational driving is generated.

According to a third aspect of the present invention, in the first or second aspect, the shape of the non-contacting side of the contact portion of the connection projection with the connection hole is twisted in the direction of the rotation center axis and is not closer to the tip. Is a process cartridge characterized in that the root side is bulged.

The opposite side of the contact portion of the connection protrusion that is not in contact with the connection protrusion is twisted so as to bulge from the tip of the connection protrusion toward the root, so that the connection protrusion and the connection hole can easily be initially engaged. The cross section can be enlarged without impairing the height, and the strength of the connecting projection can be increased.

[0019]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below in detail with reference to the drawings.

Next, a preferred embodiment of the present invention will be described. In the following description, the process cartridge B
The short direction means that the process cartridge B is
4, which is the same as the direction in which the recording medium is conveyed. The longitudinal direction of the process cartridge B is
This is a direction intersecting (substantially perpendicular to) the direction in which the process cartridge B is attached to and detached from the apparatus main body 14, a direction parallel to the surface of the recording medium, and intersecting (substantially perpendicular to) the conveying direction of the recording medium. . The left and right of the process cartridge are right or left when the recording medium is viewed from above according to the recording medium transport direction.

FIG. 1 is an explanatory diagram of a configuration of an electrophotographic image forming apparatus (laser beam printer) to which an embodiment of the present invention is applied, and FIG. 2 is an external perspective view thereof. 3 to 8 are drawings related to a process cartridge to which an embodiment of the present invention is applied. 3 is a side sectional view of the process cartridge, FIG. 4 is an external perspective view schematically showing the external appearance, FIG. 5 is a right side view thereof, FIG. 6 is a left side view thereof, and FIG. FIG. 8 is a perspective view when the process cartridge is turned over and viewed from above. Further, in the following description, the upper surface of the process cartridge B is a surface located above when the process cartridge B is mounted on the apparatus main body 14, and the lower surface is a surface located below.

(Electrophotographic Image Forming Apparatus A and Process Cartridge B) First, a laser beam printer A as an electrophotographic image forming apparatus to which an embodiment of the present invention is applied will be described with reference to FIGS. FIG. 3 is a side sectional view of the process cartridge B.

As shown in FIG. 1, the laser beam printer A forms an image on a recording medium (for example, recording paper, OHP sheet, cloth, etc.) by an electrophotographic image forming process. Then, a toner image is formed on a drum-shaped electrophotographic photosensitive member (hereinafter, referred to as a photosensitive drum).
More specifically, the photosensitive drum is charged by the charging unit, and then the photosensitive drum is irradiated with a laser beam corresponding to the image information from the optical unit to form a latent image corresponding to the image information on the photosensitive drum. The latent image is developed by a developing unit to form a toner image. Then, in synchronization with the formation of the toner image, the recording medium 2 set in the sheet feeding cassette 3a is picked up by the pickup roller 3b and the conveying roller pair 3
It is reversed and conveyed by c, 3d and a pair of registration rollers 3e. Next, the toner image formed on the photosensitive drum 7 of the process cartridge B is transferred to the recording medium 2 by applying a voltage to a transfer roller 4 as a transfer unit. Thereafter, the recording medium 2 to which the toner image has been transferred is transported to the fixing unit 5 by the transport guide 3f. The fixing unit 5 includes a driving roller 5c and a fixing roller 5 including a heater 5a.
b. Then, heat and pressure are applied to the passing recording medium 2 to fix the transferred toner image. Then, the recording medium 2 is conveyed by a pair of discharge rollers 3g, 3h, 3i, and discharged to a discharge tray 6 through a reversing path 3j. The discharge tray 6 is provided on the upper surface of the apparatus main body 14 of the image forming apparatus A. It is also possible to operate the swingable flapper 3k and discharge the recording medium 2 by the discharge roller pair 3m without passing through the reversing path 3j. In the present embodiment, the pickup roller 3b, the transport roller pair 3c, 3d, the registration roller pair 3e, the transport guide 3
f, discharge roller pair 3g, 3h, 3i and discharge roller pair 3
The transport means 3 is constituted by m.

On the other hand, in the process cartridge B, as shown in FIGS. 3 to 8, the photosensitive drum 7 having the photosensitive layer 7e (see FIG. 11) is rotated, and the surface thereof is transferred to the charging roller 8 as a charging means. Is uniformly charged by the application of the voltage. Next, a laser beam corresponding to the image information from the optical system 1 is applied to the photosensitive drum 7 through the exposure opening 1e to form a latent image. Then, the latent image is developed by developing means 9 using toner. That is, the charging roller 8
Is provided in contact with the photosensitive drum 7 and charges the photosensitive drum 7. The charging roller 8 is driven and rotated by the photosensitive drum 7. The developing unit 9 supplies toner to a developing area of the photosensitive drum 7 to develop a latent image formed on the photosensitive drum 7. The optical system 1 includes a laser diode 1a, a polygon mirror 1b, a lens 1
c, a reflection mirror 1d.

Here, the developing means 9 includes the toner container 1
The toner in 1A is rotated by rotation of the toner feeding member 9b.
It is sent to the developing roller 9c. Then, the developing roller 9c having the fixed magnet built therein is rotated, and the developing blade 9c is rotated.
A toner layer provided with a triboelectric charge by d is formed on the surface of the developing roller 9c, and the toner is supplied to the developing area of the photosensitive drum 7. Then, the toner is transferred to the photosensitive drum 7 in accordance with the latent image to form a toner image and visualize the toner image. Here, the developing blade 9d
Defines the amount of toner on the peripheral surface of the developing roller 9c and imparts a triboelectric charge. A toner stirring member 9e for circulating toner in the developing chamber is rotatably mounted near the developing roller 9c.

Then, a voltage having a polarity opposite to that of the toner image is applied to the transfer roller 4 to transfer the toner image formed on the photosensitive drum 7 to the recording medium 2.
By 0, the residual toner on the photosensitive drum 7 is removed.
Here, the cleaning means 10 scrapes off the toner remaining on the photoconductor drum 7 by an elastic cleaning blade 10a provided in contact with the photoconductor drum 7 and collects it in the waste toner reservoir 10b.

In the process cartridge B, a toner frame 11 having a toner container (toner storage section) 11A for storing toner and a developing frame 12 for holding developing means 9 such as a developing roller 9c are connected. A cleaning means 10 such as a photosensitive drum 7, a cleaning blade 10a, and the like, and a cleaning frame 13 to which a charging roller 8 is attached are combined with the photosensitive drum 7. The process cartridge B is moved by the operator to the image forming apparatus main body 14.
It is removable.

The process cartridge B is provided with an exposure opening 1e for irradiating the photosensitive drum 7 with light corresponding to image information and a transfer opening 13n for facing the photosensitive drum 7 to the recording medium 2. is there. More specifically, the exposure opening 1e is provided in the cleaning frame 13, and the transfer opening 13n is formed between the developing frame 12 and the cleaning frame 13.

Next, the configuration of the housing of the process cartridge B according to the present embodiment will be described.

In the process cartridge B shown in this embodiment, the photosensitive member is housed in a housing formed by connecting a toner frame 11 and a developing frame 12 and a cleaning frame 13 is rotatably connected thereto. A cartridge is formed by accommodating the drum 7, the charging roller 8, the developing means 9, the cleaning means 10, and the like. Then, the process cartridge B is detachably mounted on a cartridge mounting means provided on the image forming apparatus main body 14.

(Structure of Housing of Process Cartridge B) The process cartridge B according to the present embodiment is
As described above, the housing is configured by combining the toner frame 11, the developing frame 12, and the cleaning frame 13. Next, the configuration will be described.

As shown in FIG. 3, a toner feeding member 9b is rotatably attached to the toner frame 11. A developing roller 9c and a developing blade 9d are mounted on the developing frame 12, and a stirring member 9e for circulating toner in the developing chamber is rotatably mounted near the developing roller 9c. As shown in FIG. 3, the developing frame 12 faces the longitudinal direction of the developing roller 9c.
An antenna rod 9h is attached substantially parallel to c. Then, the toner frame 11 and the developing frame 12 are welded (in this embodiment, ultrasonic welding JP) to form a developing unit D (see FIG. 13) as an integrated second frame.

When the process cartridge B is removed from the main body 14 of the image forming apparatus, the drum shutter member 18 which covers the photosensitive drum 7 and protects the photosensitive drum 7 from exposure to light for a long time or from contact with foreign matter, etc. Attached to.

As shown in FIG. 6, the drum shutter member 18 has a shutter cover 18a for opening and closing the transfer opening 13n shown in FIG. 3, and links 18b and 18c for supporting the shutter cover 18a. At both ends in the longitudinal direction of the shutter cover 18a and on the upstream side in the transport direction of the recording medium 2, one end of a right link 18c is pivotally attached to a hole 40g of the developing holder 40 as shown in FIGS. As shown in FIGS. 6 and 7, one end of the left link 18c is pivotally attached to a boss 11h provided on the lower frame 11b of the toner frame 11. The other ends of the links 18c on both sides are pivotally mounted on the upstream side in the mounting direction of the process cartridge B of the shutter cover 18a. The link 18c is a metal wire, and a portion pivotally connected to the shutter cover 18a is connected between both sides of the process cartridge B, and the left and right links 18c are integrated. The link 18b is provided only on one side of the shutter cover 18a. One end of the link 18b is pivotally attached to the shutter cover 18a at the downstream end in the transport direction of the recording medium 2 from the position where the link 18c is pivotally connected, and the other end is developed. It is pivotally attached to a dowel 12 d provided on the frame 12. This link 18b is a synthetic resin.

The links 18b and 18c have different lengths, and form a four-bar chain mechanism in which the shutter cover 18a and the frame including the toner frame 11 and the developing frame 12 are linked. The side projections 18c1 provided on the links 18c on both sides come into contact with a fixed member (not shown) provided near the cartridge mounting space S of the image forming apparatus 14,
The movement of the process cartridge B operates the drum shutter member 18 to open the shutter cover 18a.

The shutter cover 18a and the link 18
b, 18c, the drum shutter member 18
The shutter cover 18a is biased so as to cover the transfer opening 13n by a not-shown torsion coil spring inserted into 2d and locked at one end by a link 18b and at the other end by the developing frame 12.

As shown in FIGS. 3 and 12, the photosensitive frame 7, the charging roller 8 and the cleaning means 10 are attached to the cleaning frame 13 to form a cleaning unit C (FIG. 12) as a first frame. Reference).

Then, the developing unit D and the cleaning unit C are rotatably connected to each other by a connecting member 22 of a round pin, thereby forming a process cartridge B. That is, as shown in FIG. 13, a circular turning hole 20 is provided at the tip of an arm portion 19 formed on both sides in the longitudinal direction (axial direction of the developing roller 9c) of the developing frame 12 in parallel with the developing roller 9c. (See FIG. 13).
On the other hand, concave portions 21 for entering the arm portions 19 are provided at two places on both sides in the longitudinal direction of the cleaning frame 13 (see FIG. 12). The arm 19 is inserted into the recess 21, the coupling member 22 is press-fitted into the mounting hole 13 e of the cleaning frame 13, and is fitted into the pivot hole 20 at the end of the arm 19 and further press-fitted into the inner hole 13 e. By attaching the developing unit D and the cleaning unit C, the developing unit D and the cleaning unit C are rotatably connected around the connecting member 22. At this time, the compression coil spring 22a inserted and attached to a dowel (not shown) standing upright at the root of the arm 19 is attached to the cleaning frame 1.
By pressing the developing frame 12 downward by the compression coil spring 22a against the upper wall of the concave portion 21 of the third 3, the developing roller 9c is reliably pressed against the photosensitive drum 7. The upper wall of the concave portion 21 of the cleaning frame 13 is inclined so that the compression coil spring 22a gradually increases the compression from the non-compression state when the developing unit D and the cleaning unit C are assembled. Therefore, as shown in FIG. 13, by attaching spacer rollers 9i having a diameter larger than that of the developing roller 9c to both ends in the longitudinal direction of the developing roller 9c, the rollers 9i are pressed against the photosensitive drum 7, and the photosensitive drum 7 and the developing roller 9c oppose each other at a constant interval (about 300 μm). Therefore, the developing unit D and the cleaning unit C are rotatable with respect to each other about the coupling member 22, where the peripheral surface of the photosensitive drum 7 and the peripheral surface of the developing roller 9c are moved by the elastic force of the compression coil spring 22a. Can be maintained.

As described above, since the compression coil spring 22a is attached to the developing frame 12 at the root side of the arm portion 19, the pressing force of the compression coil spring 22a does not reach other than the root of the arm portion 19, and Even if the circumference of the spring seat is not particularly strengthened so that the attached member is used as a spring seat, the root side of the arm portion 19 is a portion having high strength and rigidity, which is effective in maintaining accuracy.

(Structure of Guide Means for Process Cartridge B) Next, guide means for attaching and detaching the process cartridge B to and from the apparatus main body 14 will be described. This guide means is shown in FIGS. FIG. 9 is a left perspective view when the process cartridge B is viewed in a direction (arrow X) in which the process cartridge B is mounted on the apparatus main body 14 (when viewed from the developing unit D side). FIG. 10 is a perspective view of the right side.

As shown in FIGS. 4, 5, 6, and 7, guide means serving as guides for attaching and detaching the process cartridge B to and from the apparatus main body 14 are provided on both outer side surfaces of the cleaning frame 13. Is provided. The guide means includes a cylindrical guide 13aR as a positioning guide member,
13aL and detent guides 13bR and 13bL as guide members serving as attitude holding means at the time of attachment / detachment.

As shown in FIG. 5, the cylindrical guide 13a
R is a hollow cylindrical member, and a detent guide 13bR
Is formed integrally with the cylindrical guide 13aR, and projects almost radially integrally from the circumference of the cylindrical guide 13aR. The mounting flange 13a is attached to the cylindrical guide 13aR.
R1 is provided integrally. Thus, the cylindrical guide 13aR, the detent guide 13bR, the mounting flange 13
The right guide member 13R having aR1 is the mounting flange 1
The small screw 13aR2 is screwed and fixed to the cleaning frame 13 through the small screw hole 3aR1. The detent guide 13bR of the right guide member 13R fixed to the cleaning frame 13 is disposed on the side of the developing frame 12 so as to extend to the side of the developing holder 40 fixed to the developing frame 12. I have.

As shown in FIG. 6, the enlarged diameter portion 7a of the drum shaft 7a is inserted into the hole 13k1 of the cleaning frame 13 (see FIG. 11).
2 are fitted. Then, it is fitted to a positioning pin 13c protruding from the side surface of the cleaning frame 13 and is stopped from rotating. The flat flange 29 fixed to the cleaning frame 13 with small screws 13d is directed outward (perpendicular to the plane of FIG. 6). The cylindrical guide 13aL protrudes toward the front side. The fixed drum shaft 7a rotatably supports the spur gear 7n fitted on the photosensitive drum 7 inside the flange 29 (see FIG. 11). The cylindrical guide 13aL and the drum shaft 7a are coaxial. The flange 29, the cylindrical guide 13aL, and the drum shaft 7a
Is integrally or integrally made of a metal material, for example, an iron material.

As shown in FIG. 6, the cylindrical guide 13aL
The rotation preventing guide 13bL, which is slightly apart from the cylindrical guide 13aL in the radial direction of the cylindrical guide 13aL,
Are formed integrally with the cleaning frame 13 so as to protrude to the side of the cleaning frame 13. The flange 29 is cut off at a portion where the detent guide 13bL interferes with the flange 29. The protrusion height of the rotation preventing guide 13bL to the side is such that the top surface substantially coincides with the top surface of the cylindrical guide 13aL. The detent guide 13bL extends to the side of the developing roller bearing box 9v fixed to the developing frame 12. As described above, the left guide member 13L includes a metal cylindrical guide 13aL and a synthetic resin detent guide 13bL.
Are provided separately from each other.

Next, the upper surface 13i of the cleaning unit C
Will be described. Here, the upper surface is a surface located above when the process cartridge B is mounted on the image forming apparatus main body 14.

In the present embodiment, as shown in FIGS. 4 to 7, the right and left ends 13p and 13q of the upper surface 13i of the cleaning unit C in a direction perpendicular to the mounting direction of the process cartridge are respectively regulated. A contact portion 13j is provided. The regulation contact portion 13j defines the position of the process cartridge B when the process cartridge B is mounted on the image forming apparatus main body 14. That is, when the process cartridge B is mounted on the apparatus image forming main body 14, the regulating contact portion 13j is fixed to the fixed member 25 (see FIGS. 9 and 10) provided on the image forming apparatus main body 14.
Abuts on the process cartridge B and the cylindrical guide 1
Rotational positions around 3aR and 13aL are defined.

Next, guide means on the image forming apparatus main body 14 side will be described. Opening / closing member 35 of image forming apparatus main body 14
Is rotated counterclockwise in FIG. 1 around the fulcrum 35a, the upper part of the image forming apparatus main body 14 is opened, and the mounting portion of the process cartridge B looks like FIG. 9 and FIG. When viewed from the mounting direction of the process cartridge B on the left and right inner walls of the image forming apparatus main body 14 from the opening where the opening / closing member 35 is opened, guide members 16R and 16L are provided on the left and right sides, respectively, as shown in FIG. Is provided.

As shown in the figure, the guide members 16R, 16L
The guide portions 16a and 1 are obliquely provided so as to descend forward as viewed from the arrow X in the insertion direction of the process cartridge B.
6c and the cylindrical guides 13aR, 13a of the process cartridge B connected to the guide portions 16a, 16c, respectively.
It has semicircular positioning grooves 16b and 16d into which L just fits. The peripheral walls of the positioning grooves 16b and 16d have a cylindrical shape. The centers of the positioning grooves 16b and 16d are at the center of the cylindrical guides 13aR and 13aL of the process cartridge B when the process cartridge B is mounted on the apparatus main body 14.
Therefore, it also coincides with the center line of the photosensitive drum 7.

The width of the guide portions 16a and 16c is such that the cylindrical guide 13a is
R and 13aL have a width for loose fitting. Cylindrical guide 13
Although the detent guides 13bR and 13bL each having a narrower width than the diameters of the aR and 13aL fit loosely, the cylindrical guides 13aR and 13aL and the detent guide 13 naturally fit loosely.
The rotation of bR and 13bL is restricted by the guide portions 16a and 16c, and the process cartridge B is mounted while maintaining a certain range of posture. When the process cartridge B is mounted on the image forming apparatus main body 14, the cylindrical guides 13aR and 13aL of the process cartridge B are provided.
Are the positioning grooves 16b of the guide members 13R and 13L, respectively.
16 d and the right and left regulating contact portions 13 j of the cleaning frame 13 of the process cartridge B contact the fixed member 25 of the apparatus main body 14.

In the above-described process cartridge B, if the center lines connecting the centers of the cylindrical guides 13aR and 13aL at the cleaning unit C side and the developing unit D side are kept horizontal, the developing unit D side is higher than the cleaning unit C side. The weight distribution is such that a large first moment is generated.

When the process cartridge B is mounted on the image forming apparatus main body 14, each of the ribs 11c on the concave portion 17 side and the lower side of the toner frame 11 is grasped with one hand, and the cylindrical guides 13aR and 13aL are respectively held by the image forming apparatus. The detents 13bR and 13bL are inserted into the guides 16a and 16c of the cartridge mounting portion of the main body 14 and then the process cartridge B is lowered forward as viewed from the insertion direction, and the detent guides 13bR and 13bL are moved to the guides 16a and 16c of the main body 14 of the image forming apparatus. insert. Cylindrical guides 13aR, 13a of process cartridge B
L, the detent guides 13bR, 13bL advance to the back side along the guide portions 16a, 16c of the image forming apparatus main body 14, and the cylindrical guides 13aR, 13b of the process cartridge B.
13aL is a positioning groove 16b of the image forming apparatus main body 14,
16d, the cylindrical guides 13aR, 13a
L is seated on the positioning grooves 16b and 16d by the gravity of the process cartridge B. Thus, the positions of the cylindrical guides 13aR and 13aL of the process cartridge B are accurately determined with respect to the positioning grooves 16b and 16d. Since the center line connecting the centers of the cylindrical guides 13aR and 13aL is the center line of the photosensitive drum 7, the position of the photosensitive drum 7 is accurately determined in the image forming apparatus main body 14.

In this state, the fixed member 25 of the image forming apparatus main body 14 and the regulating contact portion 13 of the process cartridge B are
j has a slight gap. When the hand holding the process cartridge B is released, the process cartridge B descends around the cylindrical guides 13aR and 13aL, the cleaning unit C rises, and the regulating contact portion of the process cartridge B rises. Reference numeral 13j contacts the fixed member 25 of the image forming apparatus main body 14, and the process cartridge B is accurately mounted on the image forming apparatus main body 14. Thereafter, the opening / closing member 35 is connected to the fulcrum 3 in FIG.
Rotate clockwise around 5a and close.

The process cartridge B is detached from the apparatus main body 14 in the opposite manner to the above. The opening and closing member 35 of the apparatus main body 14 is opened, and the upper and lower ribs 11c forming the handle portion of the process cartridge B are put on the hands and lifted. Then, the cylindrical guides 13aR, 13aR,
13aL rotates about the positioning grooves 16b and 16d of the apparatus main body 14, and the regulating contact portion 1 of the process cartridge B is rotated.
3j is separated from the fixing member 25 of the apparatus main body 14. When the process cartridge B is further pulled, the cylindrical guide 13a
R, 13aL escape from the positioning grooves 16b, 16d and are fixed to the apparatus main body 14 by guide members 16R, 16L.
When the process cartridge B is lifted as it is, the cylindrical guides 13aR and 13aL and the detent guides 13bR and 13bL of the process cartridge B are moved to the guide portions 16a and 16b of the apparatus body 14.
The process cartridge 16 moves up and moves upward, whereby the attitude of the process cartridge B is regulated, and the process cartridge B is taken out of the apparatus main body 14 without hitting other parts of the apparatus main body 14.

As shown in FIG. 12, the spur gear 7n
Is provided at the end of the photosensitive drum 7 opposite to the helical drum gear 7b in the axial direction. This spur gear 7n is
When the process cartridge B is mounted on the apparatus main body 14, the driving force for rotating the transfer roller 4 by engaging with a gear (not shown) coaxial with the transfer roller 4 provided on the apparatus main body 14 is provided. To communicate from.

(Toner Frame) The toner frame will be described in detail with reference to FIGS. 3, 5, and 7. FIG.

As shown in FIG. 3, the toner frame 11 is composed of two parts, an upper frame 11a and a lower frame 11b. The upper frame 11a bulges upward so as to occupy the space to the right of the optical system 1 of the main body 14 of the image forming apparatus as shown in FIG. 1, and without increasing the size of the image forming apparatus A, The amount of toner in the process cartridge B is increased. As shown in FIGS. 3, 4, and 7, a concave portion 17 is provided at the center in the longitudinal direction of the upper frame 11a from the outside, and has a function of a handle. Therefore, the operator holds the concave portion 17 of the upper frame 11a and the lower frame 1 by hand.
Hold the lower side of 1b and hold it. Note that longitudinal ribs 11c provided on one side of the concave portion 17 and below the lower frame 11b are non-slip when the process cartridge B is held. Then, as shown in FIG. 3, the flange 11a1 of the upper frame 11a is fitted to the flange 11b1 of the lower frame 11b having a peripheral edge, and is fitted to the welding surface U, and the welding ribs are melted by ultrasonic welding to thereby form the two frames. Body 11a, 11b
Is integrated. However, the joining method is not limited to ultrasonic welding, and may be, for example, heat welding, forced vibration, or bonding. When the two frames 11a and 11b are ultrasonically welded, the two frames 11a and 11b are
In addition to supporting the flanges 11a and 11b, a step 11m is provided on the upper surface outside the opening 11i and substantially on the same plane as the flange 11b1.

As shown in FIG. 3, the toner frame 11
The slope K of the lower frame 11b naturally falls when toner is consumed, that is, the slope K of the process cartridge B mounted on the apparatus main body 14 with the apparatus main body 14 being horizontal, and a horizontal line. The angle θ with Z is about 65
Degree is preferred. In addition, the lower frame 11b is recessed downward so as to escape the rotation area of the toner feeding member 9b.
g. The rotation diameter of the toner feeding member 9b is 37
mm. The concave portion 11g may be recessed from the extension of the slope K by about 0 mm to 10 mm. This is because if the concave portion 11g is located above the slope K, the toner that has naturally dropped from above the slope K will not be fed into the developing frame 12 because the toner between the concave portion 11g and the slope K will not be sent. Is expected to remain, but in the present embodiment, the toner can be reliably sent from the toner frame 11 to the developing frame 12.

As described above, by providing the concave portion 11g as a relief for the toner feeding member 9b on the bottom surface of the toner frame 11, stable toner feeding performance can be obtained without increasing the cost.

When the process cartridge B is mounted on the image forming apparatus main body 14, the cartridge-side shaft coupling member and the apparatus main body-side shaft coupling member are coupled with each other in conjunction with the closing operation of the opening / closing member 35, as described later. The photosensitive drum 7 and the like are rotatable by being driven by the apparatus main body 14.

{Coupling and Driving Configuration} Next, a description will be given of a configuration of a shaft coupling device which is a driving force transmission mechanism for transmitting a driving force from the image forming apparatus main body 14 to the process cartridge B.

FIG. 14 shows a drum flange 36 as a driving force transmitting part in which a coupling convex shaft 37 is integrally formed.
15 is a partially cutaway perspective view of the photosensitive drum 7 to which the drum flange 36 is attached. FIG. 11 is a cross-sectional view showing a state where the photosensitive drum 7 shown in FIG. FIG. 16 is an enlarged perspective view of the vicinity of the coupling convex shaft 37 of the process cartridge B shown in FIG. 11, and FIG. 17 is a coupling convex shaft 37 (provided on the process cartridge B) as a shaft coupling member.
FIG. 4 is an explanatory diagram showing the relationship between a shaft and a concave shaft 39b (provided on the apparatus main body 14).

Now, as shown in FIGS. 15 to 17, the photosensitive drum 7 attached to the process cartridge B
A cartridge-side shaft coupling member is provided at one end in the longitudinal direction. The shaft coupling member has a coupling flange 3 attached to a drum flange 36 fixed to one end of the photosensitive drum 7.
7 (cylindrical shape), and a convex portion 37 a is formed on the distal end surface of the convex shaft 37. The end face of the convex portion 37a is parallel to the end face of the convex shaft 37. In addition, the convex shaft 37
Is rotatably and axially movably fitted to the bearing 38, and functions as a drum rotation shaft. In the present embodiment, the drum flange 36, the coupling convex shaft 37 and the convex portion 37a are provided integrally. The helical drum gear 7b is transmitted to the drum flange 36 in order to transmit the driving force to the developing roller 9c inside the process cartridge B.
Are provided integrally. Therefore, as shown in FIG. 14, the drum flange 36 is an integrally molded product having the helical drum gear 7b, the convex shaft 37, and the convex portion 37a, and is a driving force transmitting component having a function of transmitting driving force. is there.

Here, the convex shaft 37 and the convex portion 37a are
When the drum flange 36 is attached to one end of the photosensitive drum 7, the drum flange 36 is provided on the drum flange 36 so as to be located coaxially with the axis of the photosensitive drum 7.
Reference numeral 36b denotes a fitting portion which is fitted to the inner surface of the drum cylinder 7d when the drum flange 36 is mounted on the photosensitive drum 7. The drum flange 36 is attached to the photosensitive drum 7 by "caulking" or "adhesion". A photosensitive layer 7e is provided around the drum cylinder 7d.
(See FIGS. 11 and 15).

The other end of the photosensitive drum 7 has
The drum flange 34 is fixed. The spur gear 7n is integrally formed with the drum flange 34 (see FIG. 11).

It is to be noted that the process cartridge B is mounted on the main assembly 1 of the apparatus.
4, the cylindrical guide 13aL is fitted and positioned in the U-shaped positioning groove 16b (see FIG. 9) of the apparatus main body 14, and the spur gear 7n formed integrally with the drum flange 34 is formed. The gear meshes with a gear (not shown) that transmits a driving force to the transfer roller 4.

The material of the drum flanges 34, 36 is polyacetal.
l), polycarbonate (polycarbonat)
e), polyamide (polyamide) and polybutylene terephthalate (polybutylenenet)
(e.g., elephthalate). However, other materials may be appropriately selected and used.

A cylindrical boss 38 a concentric with the convex shaft 37 is integrally formed with a bearing 38 fixed to the cleaning frame 13 around the convex portion 37 a of the coupling convex shaft 37 of the process cartridge B. (See FIG. 11). The process cartridge B is formed by the boss 38a.
The coupling convex portion 37a is protected when attaching and detaching the
Protected from damage and deformation due to external force. Therefore, it is possible to prevent rattling and vibration at the time of coupling driving due to damage to the convex portion 37a.

The shape of the boss 38a is not limited to the circular shape shown in the present embodiment, but may be guided by the guide portion 16c.
As long as it can be just fitted to d, for example, it may be not a perfect cylindrical shape but a partially circular arc shape. Further, in the present embodiment, an example is shown in which a bearing 38 for rotatably supporting the coupling convex shaft 37 and a cylindrical boss 38a are integrally formed and screwed to the cleaning frame 13 (not shown). However, the bearing 38 and the boss 38a may be separate bodies (see FIG. 11).

In this embodiment, the drum flange 34 is fitted to the drum shaft 7a integrated with the cylindrical guide 13aL provided on the cleaning frame 13 (FIG. 11).
The photosensitive drum 7 is attached to the cleaning frame 13 of the process cartridge B in a state where the coupling convex shaft 37 is fitted to the inner surface of the bearing 38 attached to the cleaning frame 13. I have. Then, the photosensitive drum 7 rotates around the coupling convex shaft 37 and the drum shaft 7a. In the present embodiment,
The photosensitive drum 7 is attached to the cleaning frame 13 so as to be movable in the axial direction as shown in FIG. This is because the mounting tolerance was considered. However, the present invention is not limited to this, and the photosensitive drum 7 may be attached to the cleaning frame 13 so as not to move in the axial direction. That is, the end face 7b1 of the drum flange 36 (the end face of the helical gear 7b) is connected to the end face 38 of the bearing 38.
b, and the end face 34a of the drum flange 34 may be slidably contacted with the step 7a3 of the drum shaft 7a fixed to the cleaning frame 13.

On the other hand, the image forming apparatus main body 14 is provided with a main body shaft coupling device. In this main body shaft coupling device, a coupling concave shaft 39b (cylindrical shape) is disposed at a position substantially coinciding with the axis of the photosensitive drum 7 when the process cartridge B is mounted on the device main body 14 (FIG. 11). reference). As shown in FIG. 18, the coupling concave shaft 39b is a drive shaft integrated with the large gear 43 that transmits the driving force of the motor 61 to the photosensitive drum 7. The coupling concave shaft 39b is provided at the rotation center of the large gear 43 and protrudes from a side end of the large gear 43 (see FIGS. 19 and 20). In the present embodiment, the large gear 43 and the coupling concave shaft 39b are formed by integral molding.

The large gear 43 on the side of the apparatus body 14 is formed by a helical gear, which meshes with a small helical gear 62 fixed to the shaft 61 a of the motor 61. It has teeth having a twisting direction and an inclination angle that generate a thrust for moving the coupling concave shaft 39b in the direction of the convex shaft 37 when the driving force is transmitted from the small gear 62. The concave portion 39a is provided at the tip of the coupling concave shaft 39b and at the center of rotation of the concave shaft 39b.

In this embodiment, the driving force is fixedly mounted on the motor shaft 61a and the driving force is transmitted directly from the small gear 62 to the large gear 43. A pulley, a friction roller pair, a timing belt and a pulley may be used.

Next, a configuration in which the concave portion 39a and the convex portion 37a are fitted together with the closing operation of the opening / closing member 35 as shown in FIG.
This will be described with reference to FIGS.

As shown in FIG. 23, a side plate 67 is fixedly provided between the side plate 66 provided on the apparatus main body 14 and the large gear 43. The side plates 66, 67 are integrally formed at the center of the large gear 43. The provided coupling concave shaft 39b is rotatably supported. An outer cam 6 is provided between the large gear 43 and the side plate 66.
3 and the inner cam 64 are densely inserted. The inner cam 64 is fixed to the side plate 66, and the outer cam 63 is rotatably fitted to the coupling concave shaft 39b. The axially opposed surface of the outer cam 63 and the inner cam 64 is a cam surface, which is a threaded surface that is in contact with the coupling concave shaft 39b. A compression coil spring 68 is compressed between the large gear 43 and the side plate 67 and inserted into the coupling concave shaft 39b.

As shown in FIG. 21, an arm 63a is provided radially from the outer periphery of the outer cam 63.
Of the opening / closing member 35 from the shaft 35a of the opening / closing member 35
In the state in which is closed, the position of the end opposite to the open side end of the opening / closing member 35 in the radial direction obliquely downward and left in FIG. 21 is connected to both ends of one link 65 by pins 65a and 65b, respectively. It is.

FIG. 22 is a view of FIG. 21 as viewed from the right. When the opening / closing member 35 is closed, the link 65, the outer cam 63 and the like are in the positions shown in FIG.
And the concave portion 39a is fitted so that the driving force of the large gear 43 can be transmitted to the photosensitive drum 7. When the opening / closing member 35 is opened, the pin 65a rotates about the shaft 35a and rises, the arm 63a is pulled up via the link 65, and the outer cam 63 rotates, so that the outer cam 63 and the inner cam 64 face each other. The cam surface slides and the large gear 43 moves in a direction away from the photosensitive drum 7. At this time, the large gear 43 is
23, and moves while pressing the compression coil spring 68 attached between the side plate 67 and the large gear 43, and as shown in FIG.
7a, the coupling of the shaft coupling is released, and the process cartridge B becomes detachable.

Conversely, when the cover 35 is closed, the pin 65a connecting the member 35 and the link 65 is connected to the shaft 35a.
23, the link 65 moves downward and pushes down the arm 63a, and the outer cam 63 rotates in the opposite direction and is pushed by the compression coil spring 68, whereby the large gear 43 moves leftward from FIG. 22, the large gear 43 is again set to the position shown in FIG. 22, the coupling concave portion 39a is fitted into the coupling convex portion 37a, and the state returns to the state where the drive can be transmitted. With such a configuration, the process cartridge B can be made detachable and drivable according to the opening and closing of the open / close cover 35. When the opening / closing member 35 is closed, the outer cam 63 rotates in the reverse direction, and the large gear 43 moves leftward from FIG.
Even if b and the end face of the coupling convex shaft 37 abut, and the coupling convex portion 37a and the coupling concave portion 39a do not engage with each other, they immediately engage after the image forming apparatus A is started as described later.

As described above, in the first embodiment, when the process cartridge B is attached to or detached from the apparatus main body 14, the opening / closing member 35 is opened. In conjunction with the opening / closing of the opening / closing member 35, the coupling recess 39a moves in the horizontal direction (arrow j).
Direction). Therefore, when the process cartridge B is attached to and detached from the apparatus main body 14, the convex portion 37a of the process cartridge B and the concave portion 39a of the apparatus main body 14 are not connected. They are not linked. Therefore, the process cartridge B can be smoothly attached to and detached from the apparatus main body 14. Further, in the first embodiment, the coupling recess 39 a is formed by the compression coil spring 68 so that the large gear 43.
Is pressed in the direction of the process cartridge B. Therefore, when the coupling convex portion 37a and the concave portion 38a engage with each other, the coupling convex portion 37a
Even if the recesses 38a collide with each other and are not properly engaged with each other, the motor 61 rotates only after the process cartridge B is mounted on the apparatus main body 14, whereby the coupling recesses 38a rotate, so that they are instantaneously engaged with each other.

(Coupling Means) Next, the construction and operation of the projection 37a and the recess 39a, which are the engaging portions of the coupling means, will be described.

Although the coupling concave shaft 39b provided on the apparatus main body 14 is movable in the axial direction as described above, it is supported so as not to move in the radial direction (radial direction). On the other hand, the process cartridge B is mounted on the apparatus main body 14 so as to be movable in the longitudinal direction. In addition,
When the process cartridge B is movable in the longitudinal direction, the photosensitive drum 7 may or may not be movable in the longitudinal direction with respect to the cartridge frame. Further, the process cartridge B may be mounted so as not to move in the longitudinal direction with respect to the apparatus main body 14. In this case,
The photosensitive drum 7 is mounted movably in the longitudinal direction of the cartridge frame.

That is, when the process cartridge B is mounted on the apparatus main body 14, the drum shaft 7a into which the drum flange 34 attached to the other longitudinal end of the photosensitive drum 7 is fitted.
The cylindrical guide 13aL concentric with the drum flange 34 (see FIG. 11) enters the positioning groove 16b (see FIG. 9) of the apparatus main body 14 and is fitted and positioned without a gap. Tooth gear 7n is transfer roller 4
And a gear (not shown) for transmitting a driving force to the gear. On the other hand, at one end (drive side) in the longitudinal direction of the photosensitive drum 7, a boss 38a provided on the cleaning frame 13 is
Is fitted and positioned in the positioning groove 16d provided in the first position. When the opening / closing member 35 is closed as described above, the concave portion 39a moves horizontally and enters the convex portion 37a (see FIG. 24).

Next, positioning and drive transmission are performed on the drive side (coupling side) as follows.

First, when the main drive motor 61 rotates, the coupling concave shaft 39b is urged in the direction of the coupling convex shaft 37 (the direction of the arrow d in FIG. 19), and is pushed and engaged by the compression coil spring 68. At the point in time when there was no phase between the convex portion 37a and the concave portion 39a (in the present embodiment, since the cross section of the concave portion 39a is a substantially equilateral triangle, they can be engaged at every 120 °), they are engaged, The rotational force is transmitted from the apparatus main body 14 to the process cartridge B (from the state shown in FIG. 19 to the state shown in FIG. 20).

In this coupling engagement, the projection 37a
24 enters the concave portion 39a, as shown in FIG. 24 (a), there is a difference in the size of the cross-section between the two, and the liquid enters smoothly with a gap.

The convex portion 37a has a uniform cross section and is not twisted in the axial direction of the center of rotation, and has a shape in which a large circle r1 and a small circle r2 are connected by a common tangent line TL.

Further, a concave portion 39 fitted with the convex portion 37a is provided.
a is a hole having a substantially equilateral triangle (a hole formed by cutting a triangular prism) as shown by a broken line in FIG.

As shown in FIG. 24, the triangular inscribed circle R1 of the concave portion 39a has a cross-sectional shape of the concave portion 39a and the convex portion 37a.
It has a relationship that it is larger than the large circle r1 of the convex portion 37a and smaller than the circumscribed circle R0 of the large circle r1 and the small circle r2, that is, (r2 <r1 <R1 <R0).

Then, when the coupling concave shaft 39b rotates with the convex portion 37a inserted into the concave portion 39a, FIG.
As shown in (b), the inner surface 39a11 of the concave portion 39a has the ridge line 37a11 of the small circle r2 of the convex portion 37a and the inner surface 39a.
12 is a ridge line 37a12 of a large circle r1 of the convex portion 37a;
The inner surface 39a13 is in contact with another ridge line 37a13 of the large circle r1 of the convex portion 37a, and the driving force is transmitted.
Here, the inner surfaces 39a11, 39a12, 39a13 are respectively different surfaces of the triangular prism forming the concave portion 37a.

As described above, all the contact portions of the convex portions 37a with the concave portions 39a are circular curves, and the entire inner surface 39a1 (3
9a11, 39a12, and 39a13) can realize a state closer to a surface contact state than contact at any corner as compared with contact at a ridge line of a corner, so that the strength is high and the wear is advantageous. .

Further, since neither the convex portion 37a nor the concave portion 39a is twisted in the direction of the center of rotation, no force is generated in the thrust direction. Therefore, the driving force required to rotate the convex portion 37a is only the force required for rotation, and the power consumption of the motor 60 can be reduced. In addition, the force applied to the contact portion can be reduced, and the strength described above can be reduced. -It is more advantageous in terms of wear.

Further, since the cross-sectional shape is an extremely simple shape composed of two circles and their tangents, manufacture is easy.

In the above, in order to determine the axial positions of the process cartridge B and the photosensitive drum 7, the process cartridge B is mounted on the apparatus main body 14 when the process cartridge B is mounted on the apparatus main body 14.
For example, the side plate of the cleaning frame 13 is moved so that the position in the longitudinal direction is determined.
In the case where the coupling convex portion 37a is configured to abut against the coupling concave portion 39a, the coupling convex portion 37a moves in the axial direction with respect to the coupling concave portion 39a as shown in FIG. So that the end face 7b1 of the drum gear 7b of the drum flange 36 is not
8 may be brought into contact with the inner end surface 38b.

Furthermore, when the coupling convex portion is compared with the concave portion, the convex portion is easily damaged in shape, and is inferior in strength to the concave portion. For this reason, in the present embodiment, a coupling convex portion is provided in the process cartridge B so as to be replaceable, and a coupling concave portion is provided in the image forming apparatus main body 14 requiring higher durability. However, a coupling concave portion may be provided in the process cartridge B, a coupling convex portion may be provided in the apparatus body 14, and the driving force may be transmitted by fitting the convex portion and the concave portion.

In the first embodiment, the shape of the concave portion 39a of the coupling concave shaft 39b is an untwisted shape such as a hollow triangular prism, but may be a twisted shape.

According to this embodiment, the driving force can be stably and reliably transmitted from the coupling concave shaft 38 of the apparatus main body 14 to the coupling convex shaft 37 of the process cartridge B.

[Second Embodiment] In the first embodiment, the protrusion 3
Although the sectional shape of 7a is made uniform in the axial direction of the center of rotation,
However, it is not limited to this. With the concave section 39a having the same cross section in the axial direction, the shape of the convex section 37a is made smaller at the front end portion where fitting with the concave section 39a is started, and is increased toward the base, so that the enlarged section comes into contact with the concave section 39a. You may.

FIG. 25 is a perspective view showing an example of the convex portion 37a, and FIG. 26 is a cross-sectional view (corresponding to FIG. 24) showing a state of connection between the convex portion 37a and the concave portion 39a. In FIG. 25, an auxiliary line is drawn by a thin line for easy understanding of the shape. The actual shape is made of these fine lines and the corners are rounded.

As going from the distal end 37a2 of the convex portion 37a to the base, the guide portion has the same cross-sectional shape as the distal end portion 37a2 shown in FIG. When the taper portion 37a3 is continuously increased, the convex portion 37a is formed by the root portion 37a4 which continues to the root while maintaining the large cross-sectional shape shown in FIG. By reducing the tip portion 37a2, the cross-sectional size is small at the tip portion 37a2 of the convex portion 37a as in the first embodiment even if the center lines of the convex portion 37a and the concave portion 39a are misaligned. 26
As shown in (a), the tip portion 37a4 of the convex portion 37a is
a, and once in the concave portion 39a, the concave portion 39a is pressed in the direction of engagement with the convex portion 37a by the force of the compression coil spring 68 (see FIG. 22). As shown in FIG. 26 (b), the two enter the recess 39a and are connected to each other.

Here, the inscribed circle R1 of the substantially equilateral triangle of the concave portion 39a and the large circle r1 of the concave portion 37a are substantially the same. Thereby, the center of the two, that is, the coupling convex shaft 37 is formed.
And the center of the coupling concave shaft 39b. Among the contact portions between the concave portion 39a and the convex portion 37a, the portions 37a42 and 37a43 of the large circle r1 are the same as those in the above example, but the ridge line 37a11 shown in FIG. 24 becomes the planar contact portion 37a41 in this case (FIG. 26). (B) recess 39a
Of the inner surface 39a11), it is possible to receive a force in a wider portion, which is further advantageous in terms of strength and wear. In addition, since the rotation center is the center of the root portion 37a4, the inspection (the amount of misalignment) in the process becomes easy.

[Embodiment 3] Embodiment 3 is different from FIG.
As shown in FIG. 7, the cross-sectional area perpendicular to the axis is continuously increased from the tip to the root of the base 37a4 of the shape of the protrusion 37a of the second embodiment, thereby further increasing the strength of the protrusion 37a. is there. Tip part 37a2, taper part 37a
The cross section of the portion 3 and the portion closest to the tip of the root portion 37a4 is the same as that of the second embodiment as shown in FIG. Convex part 3
A center line connecting the center of the small circle r2 on the tip side of 7a and the center of the small circle r2 on the root side of the convex portion 37a that contacts the contact portion 37a41 is parallel to the center line O1 of the large circle r1. Then, the cross-sectional shape of the root portion 37a4 is a circle r that is smaller by an angle proportional to the amount from the tip portion toward the root.
2 and a tangent line TL and a shape PL1 ′ obtained by rotating the shape PL1 around the center line O1 of the large circle r1. That is, as shown in FIG. 27, the Z coordinate is taken from the top to the bottom in the height direction of the root 37a4, Z = o at the top of the root 37a4, Z = h at the bottom, and the shape PL at the root. The angle formed by the center of the two small circles r2 with respect to the center O1 of the large circle r1 is shown in FIG.
As shown in FIG. 27, when α is set, the angle formed by the shapes PL1 and PL1 ′ when the Z coordinate is Z = t is (t / h) α.

Contact portion 37a of convex portion 37a with concave portion 39a
Opposite portion 37a4 twisted with respect to axis 41
Reference numeral 4 denotes a curved surface twisted about the center of the inscribed circle R1 of a substantially equilateral triangle of the concave portion 39a and the large circle r1 of the convex portion 37a as shown by the hatched portion in FIG. With this configuration, when the process cartridge B is mounted on the apparatus main body 14, the concave portion 39 a rotates and the phase of the substantially equilateral triangle and the convex portion 37 a match, and when the process cartridge B engages with the process cartridge B, the same process as in the second embodiment is performed. Since they can be engaged even if they are misaligned, the opposite portion (torsion portion) 37a44 is engaged by the force of the compression coil spring 68 while contacting the substantially regular triangular portion with a line instead of a point. No large pressure is applied to the joint.
Therefore, scratches and abrasion are reduced, and a decrease in the strength of the engagement portion can be prevented.

The tip portion 37a2 has the concave portion 3 as in the second embodiment.
Since it is smaller than the substantially equilateral triangle of 9a, it is needless to say that it has an effect of being able to engage even if the two cores are misaligned, as in the second embodiment.
Has a larger cross-sectional area from the tip to the root, so that when the convex portion 37a is deformed (falls down or twists) when it receives a force, the bristle is dropped and the strength is efficiently increased to prevent or reduce the deformation. can do.

In particular, when the concave portion 39a is formed by hollowing out a twisted triangular prism, the contact portion 37a41 at the time of driving the convex portion 37a and the concave portion 39a is not at a surface extending over almost the entire area in the direction of the rotational axis of the concave portion but at the most root side (FIG. 27). (Z coordinate becomes maximum)
Ridge line only. Even in such a case, in the present embodiment, since the cross section on the base side is enlarged, the strength is further improved (strength improvement) as compared with the second embodiment. By increasing the strength of the convex portion in this way, it is possible to prevent the center of the convex portion from being decentered or causing rotational fluctuation to deteriorate the image quality,
Can be reduced.

The following is a summary of the above-described embodiments and supplementary explanation. The first is a motor 61 serving as a drive source, a small gear 63 and a large gear 43 serving as device-body-side drive transmission means which are driven to rotate by the drive source, and a protruding portion extending in the rotation center axis direction of the drive transmission means. In the process cartridge B detachable from the image forming apparatus main body 14 having the coupling concave shaft 39b and the concave portion 39a which is a connecting hole provided on the rotation center axis of the protrusion, the photosensitive drum 7 and the photosensitive drum A charging roller 8, a developing means 9, a cleaning means 10 as a charging means, which is a process means acting on the drum 7, and a connecting projection provided integrally with the photosensitive drum 7 and in contact with the connecting hole, The contact portion with the connecting hole is a process cartridge having a convex portion 37a which is a connecting protrusion having a curved cross-sectional shape. As a result, the concave portion 39a, which is the connection hole, and the convex portion 37a, which is the connection protrusion, increase the transmission torque with a large load capacity and increase the durability.

Secondly, in the first aspect, the contact portion of the connection projection with the connection hole has a shape parallel to the rotation center axis direction of the connection hole.

Thirdly, in the first or second embodiment, the contacting portion of the connecting projection with the connecting hole has a twisted portion 37a44 in which the shape of the non-contacting side is twisted in the rotation center axis direction. The base of the convex portion 37a is thick, and the engagement with the concave portion 39a is easy, and the strength of the convex portion 37a is large. The reason why the root side of the convex portion 37a is made thicker than the distal end portion is to bulge the non-contact side, that is, the small circle r2 is twisted in the circumferential direction.

Fourthly, in the first or second aspect, the connection hole has a shape twisted in the axial direction. That is, the concave portion 39a may be a space of a twisted triangular prism, that is, a hole. In this case, the root of the convex portion 37a contacts the inner surface of the concave portion 39a. In the range where the torsion angle is small, the generatrix of the large circle r1 is almost in contact with the inner surface of the recess 39a.

Fifth, in the first or second or fourth aspect, the connection hole is a space corresponding to a triangular prism, and the connection protrusion has a large circle r1 and a center O of the large circle r1.
1, a common tangent line TL between a small circle r2 having a center O2 at a position different from 1 and a large circle r1 and a small circle r2 located on one side of a line connecting the centers of the large and small circles, respectively.
, And is inserted into the connection hole.

Sixthly, in the fifth aspect, the connection protrusion is loosely inserted into the connection hole, and at the time of rotation, a large circle r1 comes into contact with the two inner surfaces 39a12 and 39a13 of the connection hole, and a small circle r2 is connected to the remaining of the connection hole. It contacts one surface 39a11.

Seventh and fifth embodiments are characterized in that the connecting projection has a leading end starting at a leading end surface 37a2 which is loosely inserted into the connecting hole, and a large circle r1 having two inner surfaces 39a11, 3 of the connecting hole.
9a12 and any one of the common tangent lines TL contacts the other surface of the connection hole. This allows the common tangent T
The tangent plane including L makes surface contact with the remaining one surface of the concave portion 39a. Here, the tangent plane is a plane tangent to two cylinders each having a cross section of a large circle r1 and a small circle r2.

Eighthly, in the first, third or fourth aspect, the connection hole is a space corresponding to a triangular prism, and the connection protrusion has a large circle r1 and a center O of the large circle r1.
1 has a cross section surrounded by a small circle r2 having a center O2 at a position different from 1 and a common tangent TL located on one side of a center line connecting the centers O1 and O2 of the large circle r1 and the small circle r2. On one side of the center line, the same cross-sectional portion in the axial direction and on the other side of the center line, the center O2 of the small circle r2 is rotated about the center O1 of the large circle r1 and the rotation is performed. The angle was gradually increased from the tip to the root, and a tangent line TL connecting the small circle r2 and the large circle r1 and an envelope surface formed by the small circle r2 were provided, and the root side was thickened.

Ninth, in any one of the first to eighth aspects, the diameter of the large circle r1 is equal to or slightly smaller than the diameter of the inscribed circle R1 of the connection hole.

Tenthly, in any one of the first to ninth aspects, the distal end of the connecting projection has a tapered portion 3 whose cross section gradually expands following the foremost portion which is loosely inserted into the connecting hole.
7a3, and has a cross section substantially similar to the cross section of the foremost portion following the tapered portion 37a3. This taper portion 37
The cross section following a3 is uniform at the root of the projection 37a.

[0114]

As described above, according to the invention of the present application, the following effects can be obtained.

Driving force can be transmitted stably and reliably.

It is easy to manufacture.

When the connection hole is not twisted in the axial direction, a further energy-saving device can be obtained.

Further, when the side of the connecting projection that does not contact the connecting hole is bulged at the root side, an even higher quality image can be obtained.

[Brief description of the drawings]

 Each of the drawings shows an embodiment of the present invention,

FIG. 1 is a longitudinal sectional view of an electrophotographic image forming apparatus.

FIG. 2 is an external perspective view of the apparatus shown in FIG.

FIG. 3 is a vertical sectional view of the process cartridge.

4 is an external perspective view of the process cartridge shown in FIG. 3 as viewed from the upper right side.

FIG. 5 is a right side view of the process cartridge shown in FIG.

FIG. 6 is a left side view of the process cartridge shown in FIG.

7 is an external perspective view of the process cartridge shown in FIG. 3 as viewed from the upper left side.

FIG. 8 is an external perspective view showing a lower left side of the process cartridge shown in FIG. 3;

FIG. 9 is an external perspective view of a mounting portion of a process cartridge of the apparatus main body.

FIG. 10 is an external perspective view of a process cartridge mounting portion of the apparatus main body.

FIG. 11 is a longitudinal sectional view of a photosensitive drum and a driving device thereof.

FIG. 12 is a perspective view of a cleaning unit.

FIG. 13 is a perspective view of a developing unit.

FIG. 14 is a perspective view of a drum flange (a driving force transmitting component) according to the embodiment.

FIG. 15 is a perspective view of a photosensitive drum according to the embodiment.

FIG. 16 is a perspective view of a shaft coupling portion of the process cartridge according to the embodiment.

FIG. 17 is a perspective view of the shaft coupling according to the embodiment.

FIG. 18 is a sectional view showing a drive system of the main body of the electrophotographic image forming apparatus according to the embodiment.

FIG. 19 is a perspective view of a shaft coupling member provided on the apparatus main body according to the embodiment and a shaft coupling member provided on the process cartridge.

FIG. 20 is a perspective view of a shaft coupling member provided in the apparatus main body according to the embodiment and a shaft coupling member provided in the process cartridge.

FIG. 21 is a longitudinal sectional view illustrating a configuration of a cover and a shaft coupling portion of the apparatus main body according to the embodiment.

FIG. 22 is a side view illustrating a configuration around a coupling concave axis when the process cartridge of the apparatus main body according to the embodiment is driven.

FIG. 23 is a side view illustrating a configuration around a coupling concave axis when the process cartridge is attached to / detached from the apparatus main body according to the embodiment.

FIGS. 24A and 24B are cross-sectional views of a coupling convex portion and a concave portion according to the first embodiment.

FIG. 25 is a perspective view showing a coupling protrusion according to the second embodiment.

26A and 26B are cross-sectional views of a convex portion and a concave portion according to the second embodiment, respectively.

FIG. 27 is a perspective view showing a coupling protrusion according to the third embodiment.

FIGS. 28 (a), (b) and (c) are cross-sectional views of a coupling convex portion and a concave portion according to the third embodiment, respectively.

[Explanation of symbols]

A: laser beam printer (image forming apparatus) B: process cartridge C: cleaning unit D: developing unit JP: coupling surface K: slope r1: large circle r2: small circle TL: tangent line RO: circumscribed circle of r1 and r2 R1 ... Inscribed circles of the concave portions PL1, PL1 ': cross-sectional shape of the root h: height of the root α: angle 1: optical system 1a: laser diode 1b: polygon mirror 1c: lens 1d: reflection mirror 1e: exposure opening 2 ... Recording medium 3... Conveying means 3 a. Discharge roller pair 4 Transfer roller 5 Fixing means 5a Heater 5b Fixing roller 5c
... Driving roller 6 ... Discharge tray 7 ... Photoconductor drum 7a ... Drum shaft 7a2 ... Expanded diameter section
7a3 Stepped portion 7b Drum gear 7b1 End face 7d
... Drum cylinder 7e ... Photosensitive layer 7n ... Spur tooth gear 8 ... Charging roller 9 ... Developing means 9b ... Toner feed material 9c ... Developing roller 9d ... Developing blade 9e ... Toner stirring member 9h ... Antenna rod 9i ... Spacer roller 9j ... Developing roller bearing 9k developing roller gear 9v bearing box 10 cleaning means 10a cleaning blade 10b waste toner reservoir 11 toner frame 11A toner container 11a upper frame 11a1 flange 11b lower frame 11b
DESCRIPTION OF SYMBOLS 1 ... Flange 11c ... Rib 12 ... Developing frame 13 ... Cleaning frame (drum frame) 13aR1 ...
Flange 13aR2 ... Machine screw 13aR, 13aL ...
Cylindrical guide 13bR, 13bL ... detent guide
13c positioning pin 13d machine screw 13f regulating contact portion 13i upper surface 13j regulating contact portion 13L
Guide member 13n: transfer opening 13p: right end 1
3q: Left end 13R: Guide member 13R3: Positioning portion 13s: Outer wall 13t: Partition wall 14: Image forming apparatus main body 16 (16R, 16L): Guide member 16a: Guide portion 16b: Positioning groove 16c: Guide portion 16d:
Positioning groove 16f Positioning part 18 Drum shutter member 18a Shutter cover 18b, 18c Link 18c1 Projecting part 19 Arm part 20 Rotating hole 21 Depression 22 Joint member 22a Compression coil spring 24 Bearing 25 Fixed member 33 ... leaf spring 34 ... drum flange 34a ... end face 35 ... opening / closing member 35a ... fulcrum 36 ... drum flange 36a ... fitting part 37 ... coupling convex shaft 37a ... convex part (driven side shaft coupling part) 37a2 ... Tip part 37a3 ... taper part 37
a4 Root portions 37a11, 37a12 Ridge lines 37a13 Contact portions with concave portions 39a 37a41, 37
a42, 37a43... Contact portion 37a4 with concave portion 39a
Reference numeral 4 denotes a portion opposite to 37a41 (twisted portion) 38 ... Bearing 38a ... Boss 38b ... Inner end surface 39a ... Recess (driving side shaft coupling portion) 39a1 ... Internal surface 39a2 ... Bottom 39b ... Coupling concave shaft 40 ... Development holder 43 ... A first gear 50... A guide portion extending portion (body positioning portion) 61... A motor 61 a... A shaft 62 a small gear 63. An outer cam 63 a an arm 64 an inner cam 65 a link 65 a and 65 b a pin 66 a side plate 67. Side plate 68: Compression coil spring

Claims (10)

[Claims] 1. A drive source, an apparatus-body-side drive transmission unit that is rotationally driven by the drive source, a protruding portion extending in a rotation center axis direction of the drive transmission unit, and a projection on the rotation center axis of the projection. An electrophotographic photosensitive drum, a process unit acting on the electrophotographic photosensitive drum, and an integral part of the electrophotographic photosensitive drum. A connection protrusion provided on the contact hole and contacting the connection hole, wherein the contact portion with the connection hole has a connection protrusion having a curved cross-sectional shape. 2. The process cartridge according to claim 1, wherein a contact portion of the connection projection with the connection hole has a shape parallel to a rotation center axis direction of the connection hole. 3. The connecting projection according to claim 1, wherein the shape of the connecting projection that is not in contact with the connecting hole is twisted in the direction of the rotation center axis and bulges at the root side from the tip. Process cartridge. 4. The process cartridge according to claim 1, wherein the connection hole has a shape twisted in an axial direction. 5. The connection hole is a space corresponding to a triangular prism, and the connection protrusion is a large circle, a small circle having a center at a position different from the center of the large circle, and a large circle and a small circle, respectively. 5. A cross section surrounded by a large tangent line and a common tangent line of a small circle respectively located on one side of a line connecting the centers of the circles, and is inserted into the connection hole. A process cartridge according to any one of the above. 6. The connecting projection according to claim 1, wherein the connecting projection is loosely inserted into the connecting hole, and when rotating, a large circle contacts two surfaces of the connecting hole and a small circle contacts the remaining one surface of the connecting hole. 6. The process cartridge according to 5. 7. The connecting projection has a tip portion loosely inserted into the connecting hole, a large circle touching two surfaces of the connecting hole, and any one common tangent line touching the remaining one surface of the connecting hole. The process cartridge according to claim 5, wherein a tangent plane including a tangent makes surface contact with a remaining surface of the connection hole. 8. The connection hole is a space corresponding to a triangular prism, and the connection protrusion is a large circle, a small circle having a center at a position different from the center of the large circle, a large circle and a small circle, respectively. And a common tangent line located on one side of a center line connecting the centers of the center line.On one side of the center line, the same section in the axial direction, and on the other side of the center line, a small circle. And the angle of the rotation is gradually increased from the tip to the base, and a tangent line connecting the small circle and the large circle and an envelope surface defining a small circle r1 are provided. The process cartridge according to claim 1, wherein the root side is thickened. 9. The method according to claim 1, wherein the diameter of the large circle is equal to or slightly smaller than the diameter of the inscribed circle of the connecting hole.
The process cartridge described in any one of the above. 10. A tip of the connecting projection has a taper whose cross section gradually expands following a tip portion that is loosely inserted into the connection hole, and a cross section substantially similar to a cross section of the tip portion following the tapered portion. 10. Any one of claims 1 to 9 having:
The process cartridge described in any one of the above.