CN221008090U

CN221008090U - Process cartridge and image forming apparatus

Info

Publication number: CN221008090U
Application number: CN202322723216.8U
Authority: CN
Inventors: 李颖豪; 陈柔娟
Original assignee: Zhuhai Nastar Information Technology Co ltd
Current assignee: Zhuhai Nastar Information Technology Co ltd
Priority date: 2022-11-04
Filing date: 2023-10-10
Publication date: 2024-05-24
Anticipated expiration: 2033-10-10
Also published as: CN117991610A

Abstract

The utility model discloses a process cartridge and an image forming apparatus, the process cartridge includes: a drum unit rotatably provided with a photosensitive drum; a developing unit rotatably provided with a developing roller, a developing coupling including a meshing portion and a transmitting portion which are drivingly connected, the meshing portion being movable between an extended position and a retracted position in an axial direction of the developing coupling; a movable member for receiving a first force or a second force movement of the image forming apparatus; an action assembly cooperating with the movable member to move the engagement portion from the retracted position to the extended position upon receipt of a first force by the movable member and from the extended position to the retracted position upon receipt of a second force by the movable member; in the extended position, the developing shaft coupling receives the driving force to rotate, and the torque generated by the rotation of the developing shaft coupling enables the developing unit to move from the second position to the first position, so that the structure is simple and easy to implement, the cost is low, the service life of the processing box is prolonged, and the use stability of the processing box is improved.

Description

Process cartridge and image forming apparatus

Technical Field

The present utility model relates to the field of image forming apparatuses, and more particularly, to a process cartridge and an image forming apparatus.

Background

In the field of image forming apparatuses, an electrophotographic photosensitive member (hereinafter referred to as a photosensitive drum) and a process device acting on the photosensitive drum are integrally formed as a cartridge (generally referred to as a process cartridge). Such a process cartridge is detachable from the main assembly of the image forming apparatus.

In the related art, a process cartridge includes a photosensitive drum, a developing roller, a movable member, and a holding member, the movable member being capable of receiving a contact force (the photosensitive drum being in contact with the developing roller) from an image forming apparatus and a drum-roller spacing force (the photosensitive drum being separated from the developing roller), the process cartridge being in an initial non-operating state, the holding member being mounted on a developing unit being abutted against the drum unit to hold the drum roller apart;

When the movable member receives the contact force, the movable member pushes the retaining member to move forwards and upwards, so that the developing unit is driven to move towards the drum unit to realize the contact of the drum roller, and the retaining member is engaged with one protrusion on the drum unit after the movement, so that the retaining member always keeps the contact of the drum roller under the condition that the contact force of the image forming device to the movable member is removed;

When the movable member receives the spacing force, the developing unit is pushed away from the drum unit, so that the retaining member is driven to reset, the drum roller separation is realized, and the retaining member always maintains the drum roller separation state under the condition that the spacing force of the image forming device to the movable member is removed.

In the prior art, in the case where the process cartridge does not receive an external force, the drum roller is held in contact by virtue of engagement of the holder with the protrusions in the drum unit, since the holder is supported by the protrusions by sliding from the side surfaces of the protrusions toward the upper surfaces of the protrusions, the supported area is very small, and the holder is easily dropped due to vibration during operation of the process cartridge, or the subsequent problem of failure to engage with the protrusions due to abrasion caused by interference of the holder with the drum unit, thereby causing the problem that the drum roller cannot be held in contact during operation of the process cartridge. The technical aim of the technology is to solve the technical problems.

Disclosure of utility model

According to an aspect of the present utility model, there is provided a process cartridge detachably mountable to an image forming apparatus, comprising:

a drum unit rotatably provided with a photosensitive drum;

a developing unit rotatably provided with a developing roller, the developing unit being movable relative to the drum unit between a first position in which the developing roller is in contact with the photosensitive drum and a second position in which the developing roller is separated from the photosensitive drum;

The developing coupling is arranged on the developing unit and comprises a meshing part and a transmission part which are in transmission connection, and the meshing part can move between an extending position and a retracting position along the axial direction of the developing coupling;

A movable member movably disposed at the developing unit for receiving a first force or a second force of the image forming apparatus;

An action assembly cooperating with the movable member to move the engagement portion from a retracted position to an extended position when the movable member receives a first force and from the extended position to the retracted position when the movable member receives a second force;

In the extended position, the developing coupling is rotated by receiving a driving force, and torque generated by the rotation of the developing coupling moves the developing unit from the second position to the first position.

In some embodiments, the developing device further includes a separating elastic member disposed between the drum unit and the developing unit for moving the developing unit from the first position to the second position.

In some embodiments, the end of the developing unit is provided with a developing cap, the end of the drum unit is provided with an end cap, and the developing cap moves relative to the end cap when the developing unit moves relative to the drum unit.

In some embodiments, the action assembly includes a first pressing ring, a second pressing ring and a connecting rod, the first pressing ring and the second pressing ring are sleeved on the meshing portion, the connecting rod is arranged on the developing box cover in a swinging mode and is in driving connection with the first pressing ring, at least one part of the connecting rod is located in a motion track of the movable component, and the movable component can drive the connecting rod to move when moving.

In some embodiments, the first clamping ring is capable of pushing against the second clamping ring when in motion.

In some embodiments, the first pressing ring is provided with at least one first protrusion, the first protrusion is provided with a first inclined plane, the second pressing ring is provided with at least one second protrusion, the second protrusion is provided with a second inclined plane, and the first inclined plane is in contact with the second inclined plane.

In some embodiments, the developing box cover is provided with a limiting part, and the second pressing ring is provided with a limited part matched with the limiting part, so that the second pressing ring moves along the axial direction of the developing coupling when being pressed by the first pressing ring.

In some embodiments, when the movable component receives a second acting force to move along a second swinging direction, the connecting rod is driven to swing, the connecting rod drives the first pressing ring to rotate, and the first pressing ring rotates to generate pushing force on the second pressing ring so that the second pressing ring moves along the axial direction of the developing coupling, and the meshing part is driven to retract inwards to a retracted position along the axial direction.

In some embodiments, the acting assembly further includes a first elastic member defined between the engagement portion and the transmitting portion, the first elastic member being configured to be expandable and contractible in an axial direction of the developing coupling, the first elastic member being for extending the engagement portion axially outward to the extended position.

In some embodiments, the action assembly further includes a stopper movably disposed at the developing cartridge cover, the stopper being movable between a locking position and an unlocking position, and abutting the engagement portion when in the locking position, blocking the engagement portion from protruding axially outward.

In some embodiments, when the movable component receives a first force to move along a first swinging direction, the stop piece is driven to move from the locking position to the unlocking position, and the stop piece is separated from the meshing part.

In some embodiments, the acting assembly further includes a second elastic member defined between the stopper and the developing cartridge cover for maintaining the stopper in the locking position.

According to another aspect of the present utility model, there is provided an image forming apparatus including the process cartridge as set forth in any one of the above.

The utility model has the beneficial effects that: the processing box controls the axial movement of the meshing part of the developing coupling through the movable part and the action assembly arranged on the developing unit, when the meshing part moves to the extending position to receive the driving force, the developing unit is moved to the first position by utilizing the torque generated by rotation, and when the driving force is removed, the processing box disappears due to the action of the torque and the separation elastic piece, so that the developing unit moves to the second position.

Drawings

FIG. 1 is a schematic view showing the overall structure of a process cartridge according to some embodiments of the present utility model;

FIG. 2 is a schematic view of a process cartridge according to some embodiments of the present utility model, with the end cap and the developer cartridge cover omitted;

FIG. 3 is a schematic view showing the construction of the action assembly, engagement portion and developing cartridge cover of the process cartridge according to some embodiments of the present utility model;

FIG. 4 is a schematic view of a first clamping ring of a process cartridge according to some embodiments of the present utility model;

FIG. 5 is a schematic view of a second clamping ring of a process cartridge according to some embodiments of the present utility model;

Fig. 6 is a schematic structural view of a stopper of a process cartridge according to some embodiments of the present utility model;

FIG. 7 is a schematic side view of a process cartridge according to some embodiments of the present utility model after a movable member is depressed;

FIG. 8 is a schematic view of a structure of a process cartridge according to some embodiments of the present utility model after the movable member is depressed, with the end cap and the developer cartridge cover omitted;

FIG. 9 is an enlarged schematic view of FIG. 8 at A;

FIG. 10 is a schematic side view of a process cartridge according to some embodiments of the present utility model mated with a developer separation control unit when the developer unit is in a first position;

FIG. 11 is a schematic view of a development unit of a process cartridge according to some embodiments of the present utility model in a first position, with an end cap and a developer cartridge cover omitted;

FIG. 12 is a schematic view of the structure of the action assembly and engagement portion of the developing unit of the process cartridge of some embodiments of the present utility model in a first position;

FIG. 13 is a schematic side view of a process cartridge according to some embodiments of the present utility model mated with a developer separation control unit when the developer unit is in a second position;

FIG. 14 is a schematic view of a development unit of a process cartridge according to some embodiments of the present utility model in a second position, with the end cap and the developer cartridge cover omitted;

Fig. 15 is a schematic view showing the structure of the action assembly and the engagement portion when the developing unit of the process cartridge according to some embodiments of the present utility model is in the second position.

Detailed Description

The present utility model will now be described in further detail with reference to the accompanying drawings, wherein the embodiments described are some, but not all embodiments of the utility model. All other embodiments, which can be made by those skilled in the art based on the embodiments of the utility model without making any inventive effort, are intended to be within the scope of the utility model.

It should be noted that the terms "first," "second," and the like are used for descriptive purposes only and are not to be construed as indicating or implying a relative importance or implying a number of technical features being indicated. Thus, a feature defining "a first" or "a second" may explicitly or implicitly include at least one such feature. In the description of the present utility model, the meaning of "plurality" means at least two, for example, two, three, etc., unless specifically defined otherwise.

In the present utility model, unless explicitly specified and limited otherwise, the terms "mounted," "connected," "secured," and the like are to be construed broadly and include, for example, either fixedly attached, detachably attached, or integrally formed; may be mechanically connected, may be electrically connected or may be in communication with each other; either directly or indirectly, through intermediaries, or both, may be in communication with each other or in interaction with each other, unless expressly defined otherwise. The specific meaning of the above terms in the present utility model can be understood by those of ordinary skill in the art according to the specific circumstances.

In the present utility model, unless expressly stated or limited otherwise, a first feature "up" or "down" a second feature may be the first and second features in direct contact, or the first and second features in indirect contact via an intervening medium. Moreover, a first feature being "above," "over" and "on" a second feature may be a first feature being directly above or obliquely above the second feature, or simply indicating that the first feature is level higher than the second feature. The first feature being "under", "below" and "beneath" the second feature may be the first feature being directly under or obliquely below the second feature, or simply indicating that the first feature is less level than the second feature.

In the above description, descriptions of the terms "one embodiment," "some embodiments," "examples," "specific examples," or "some examples," etc., mean that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the utility model. In this specification, schematic representations of the above terms are not necessarily directed to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples. Furthermore, the different embodiments or examples described in this specification and the features of the different embodiments or examples may be combined and combined by those skilled in the art without contradiction.

The image forming apparatus forms an image on a recording material using, for example, an electrophotographic image forming process. The image forming apparatus includes, for example, an electrophotographic copying machine, an electrophotographic printer (LED printer, laser printer, etc.), a facsimile machine of the electrophotographic printer type, and the like. The process cartridge is detachably mounted in the image forming apparatus, and includes a photosensitive drum, a developing roller for developing an electrostatic latent image formed on the photosensitive drum, and the like. The image forming apparatus includes a driving head for transmitting a driving force of the image forming apparatus to the process cartridge to operate the process cartridge. The image forming apparatus further includes a development separation control unit 200 and a first pressing mechanism.

As shown in fig. 1, the present utility model provides a process cartridge including a developing unit, a drum unit, a driving assembly, a movable member, and an acting assembly. The developing unit includes a developing frame 11, a developing roller, a powder feeding roller, a stirring frame, and a powder discharging knife. The drum unit includes a photosensitive frame 21, a photosensitive drum, and a charging roller.

As shown in fig. 1, the developing frame 11 encloses a toner hopper for storing toner, the developing frame 11 is substantially in the shape of a long box, both ends of the developing frame 11 in the length direction are respectively provided with a driving side bearing 12 and a non-driving side bearing, and the stirring frame, the toner feeding roller and the developing roller are rotatably supported on the driving side bearing 12 and the non-driving side bearing at both ends of the developing frame 11 in the length direction, and the stirring frame, the toner feeding roller and the developing roller can rotate under the action of the driving unit, and the axial directions of the stirring frame, the toner feeding roller and the developing roller are all along the length direction of the developing frame 11. The carbon powder in the powder bin is stirred by the stirring frame, so that the carbon powder in the powder bin is prevented from caking, and meanwhile, the carbon powder can be conveyed towards the direction of the powder conveying roller, and the powder conveying roller conveys the carbon powder to the developing roller and is adsorbed by the charged developing roller.

As shown in fig. 1 and 2, the photosensitive frame 21 also has a longitudinal direction, the longitudinal direction of which coincides with the longitudinal direction of the developing frame 11, and photosensitive drums are rotatably supported at both ends of the photosensitive frame 21 in the longitudinal direction, specifically, the photosensitive drums are provided at the lower end side of the photosensitive frame 21 in the height direction. The toner adsorbed by the developing roller transfers the toner to the photosensitive drum by a potential difference with the photosensitive drum, and the toner on the photosensitive drum is transferred by a transfer belt of the image forming apparatus to form an image on a recording material (e.g., paper). The charging roller is used for charging the surface of the photosensitive drum with uniform charges, so that the photosensitive drum can adsorb carbon powder.

As shown in fig. 1 and 2, the driving assembly includes a photosensitive coupling 31, a developing coupling, a developing roller gear 33, and a powder feeding roller gear. The driving assembly may be disposed at one or both ends of the process cartridge 100 in the length direction, and in this embodiment, the driving assembly is disposed at the same end of the process cartridge 100 in the length direction. The photosensitive coupling 31 is fixedly arranged at one end of the photosensitive drum in the length direction, the photosensitive coupling 31 and the photosensitive drum can be integrally formed or can be of a split structure, and the photosensitive coupling 31 is used for being meshed with a driving head of the image forming device so as to receive the rotary driving force of the image forming device and drive the photosensitive drum to rotate. The photosensitive coupling 31 is provided with an engagement head at one end thereof remote from the end face of the photosensitive frame, and the engagement head may be a regular or irregular projection as long as it can engage with the photosensitive driving head to stably receive the driving force.

As shown in fig. 1 and 2, a developing coupling, a developing roller gear 33, and a powder feeding roller gear are provided outside the drive side bearing 12, specifically, a support hole for supporting the developing coupling for engaging with a developing drive head of the image forming apparatus and receiving a driving force is provided on the drive side bearing 12; the developing roller gear 33 is sleeved at one end of the shaft of the developing roller, which extends out of the driving side bearing 12, the powder feeding roller gear is sleeved at one end of the shaft of the powder feeding roller, which extends out of the driving side bearing 12, and the developing roller gear 33 and the powder feeding roller gear are directly or indirectly meshed with the developing coupling so as to transmit the driving force received by the developing coupling, thereby driving the developing roller and the powder feeding roller to rotate.

As shown in fig. 2, 3, 8 and 9, the developing coupling includes an engagement portion 34 and a transmission portion 35, the transmission portion 35 is of a cylindrical structure, and is supported at a support hole of the drive side bearing 12, and an outer circumferential surface thereof is provided with tooth portions, which may be a primary gear or a multistage gear, by engagement with the developing roller gear 33, the toner feeding roller gear and/or the agitator gear. The transmission portion 35 is hollow inside, and the engagement portion 34 is inserted into the transmission portion 35 and is movable in the transmission portion 35 in the axial direction between an extended position in which the engagement portion 34 is closer to the drive side bearing 12 than it is in the extended position in which the engagement portion 34 is engageable with the developing drive head to receive the driving force, and a retracted position in which the engagement portion 34 is not engageable with the developing drive head. At least two slots or insertion holes which are arranged at intervals can be formed in the inner wall or the bottom wall of the transmission part 35, one end of the engagement part 34, which is inserted into the transmission part 35, can be arranged on an insertion column 341 which is matched with the slots, so that the engagement part 34 and the transmission part 35 are in a synchronous state in the circumferential direction, one end of the engagement part 34, which is far away from the drive side shaft side 12, is an engagement head, and the engagement head can be a regular or irregular protrusion, so long as the engagement head can be engaged with the development drive head to stably receive driving force, and when the engagement part 34 receives the driving force to rotate, the transmission part 35 is driven to synchronously rotate, and the transmission part 35 transmits the driving force to other gears through tooth parts.

As shown in fig. 1, a developing box cover 15 is further provided on the outer side of the drive side bearing 12, and the developing box cover 15 covers the developing roller gear 33, the powder feeding roller gear, the stirring rack gear, and a part of the developing coupling, so that the drive assembly can be protected. Specifically, the developing box cover 15 is provided with a cylindrical portion protruding along a side away from the developing frame 11, the cylindrical portion is hollow, an axial direction thereof extends along a longitudinal direction of the developing frame, and a part of the engaging portion 34 of the developing coupling extends from the inside of the cylindrical portion to the outside of the developing box cover 15 while extending axially outward.

As shown in fig. 1, the process cartridge 100 further includes end caps provided at both ends of the process cartridge 100 in the longitudinal direction, respectively, a driving-side end cap 41 and a non-driving-side end cap 42, the non-driving-side end cap 42 being housed outside the non-driving-side bearing, the driving-side end cap 41 being housed outside the developing cartridge cover 15, and the driving-side end cap 41 and the developing cartridge cover 15 being at least partially overlapped as viewed in the longitudinal direction of the process cartridge 100. The driving-side end cap 41 and the non-driving-side end cap 42 cover at least a portion of the ends of the photosensitive frame 21 and the developing frame 11, respectively. The driving-side end cap 41 is fixedly connected to an end of the photosensitive frame 21.

In this embodiment, the driving-side end cap 41 is provided with a first through hole through which the photosensitive coupling 31 is exposed and a second through hole through which the developing coupling is exposed when the driving-side end cap 41 is mounted on the ends of the developing frame 11 and the photosensitive frame 21, so that the coupling is engaged with the driving head of the image forming apparatus to receive the driving force. On the developing frame 11 side, a developing coupling, a cylindrical portion, and a second through hole into which at least a part of the cylindrical portion is inserted are coaxially provided.

In the working process of the image forming device, the developing roller and the photosensitive drum need to be in tight contact, when the image forming device does not work, the developing roller and the photosensitive drum need to be separated by a certain distance, and the problems that the photosensitive drum is polluted by redundant developer attached to the developing roller, the developing roller deforms, the photosensitive drum is worn and the like due to long-time contact of the developing roller and the photosensitive drum are avoided.

Therefore, the developing unit in the present embodiment is provided so as to be movable relative to the drum unit, thereby enabling the developing roller and the photosensitive drum to be brought into contact when the image forming apparatus is operated and separated when not operated. When the process cartridge 100 is mounted in the image forming apparatus, the drum unit is brought into abutment with a member in the image forming apparatus, the drum unit is immovable, and the developing unit is provided so as to be movable relative to the drum unit between a first position at which the developing roller is in contact with the photosensitive drum and a second position; the developing roller is separated from the photosensitive drum when the developing unit is at the second position.

In this embodiment, the developing unit swings with the axis of the developing coupling as the rotation center, that is, when the developing unit is located at the first position, the lower end of the developing unit is close to the lower end of the drum unit, so that the developing roller can contact with the photosensitive drum, and at this time, the upper end of the developing unit is located at a position far from the drum unit; when the developing unit moves from the first position to the second position, the lower end of the developing unit swings in a direction away from the drum unit to drive the developing roller to separate from the photosensitive drum, and at the moment, the upper end of the developing unit swings in a direction close to the drum unit.

As shown in fig. 1, in the transportation and storage stage before the use of the process cartridge, it is also necessary to avoid the long-time contact between the developing roller and the photosensitive drum, in this embodiment, the process cartridge further includes a separation elastic member 61, and the separation elastic member 61 may be a tension spring, one end of which is connected to the driving-side end cover 41, and the other end of which is connected to the developing box cover 15, and the tension force of the tension spring acts on the developing unit, so that the lower end of the entire developing unit has a tendency to rotate around the rotation center away from the drum unit, and the lower end of the developing unit is away from the lower end of the drum unit, and the photosensitive drum is not in contact with the developing roller. Specifically, the driving-side end cap 41 may be provided with a first hooking portion fixedly connected to one end of the separation elastic member 61, and the developing box cover 15 may be provided with a second hooking portion fixedly connected to the other end of the separation elastic member 61.

In the process cartridge use stage, when the process cartridge 100 is mounted to the image forming apparatus, the drum unit and the image forming apparatus are relatively stationary, the end cap fixedly connected to the drum unit is also stationary with respect to the drum unit, and the process cartridge 100 receives torque generated by rotation of the driving force through the developing coupling to move the developing unit from the second position to the first position with respect to the drum unit, so that the developing roller is brought into contact with the photosensitive drum when the image forming apparatus is operated.

The driving side and the non-driving side of the developing unit are provided with movable members 51, and the movable members 51 are movably provided to the developing unit for receiving the first force or the second force of the developing separation control unit 200 of the image forming apparatus. Specifically, as shown in fig. 1, 2 and 3, the movable member 51 is a bar-like member, the movable member 51 is movable relative to the developing frame 11, and specifically, as an example of the driving side, the movable member 51 is movably provided between the driving side shaft side 12 and the developing cartridge cover 15, the upper portion of the movable member 51 is a pressure receiving portion 511, and the lower portion is a force receiving projection 512, and in the initial state (state in which the process cartridge is just set to the image forming apparatus), at least a part of the pressure receiving portion 511 protrudes from the driving side shaft 12, the upper portion of the developing cartridge cover 15 so that it can be pressed by a first pressing mechanism in the image forming apparatus, so that the movable member 51 moves downward relative to the developing frame 11, and further the force receiving projection 512 at the lower end of the movable member 51 moves to a position to be engaged with the developing separation control unit 200 of the image forming apparatus. The force receiving projection 512 is provided on the movable member 51, and before the force of the first pressing mechanism is not received, the force receiving projection 512 is in a position where it cannot be mated with the developing separation control unit 200, so that damage caused by interference and collision of the force receiving projection 512 with the developing separation control unit 200 during mounting of the process cartridge 100 can be avoided.

Further, as shown in fig. 1, the process cartridge further includes a third elastic member 62, the third elastic member 62 may be a tension spring, one end of which is connected to the movable member 51 and the other end of which is connected to the developing cartridge cover 15 for holding the movable member 51 in a position where the force receiving projection 512 is retracted upward before being subjected to the urging force of the first urging mechanism, and the third elastic member 62 is stretched after the movable member 51 is pressed by the first urging mechanism.

As shown in fig. 3, a guide groove 513 extending in the up-down direction may be provided on the movable member 51, the guide groove 513 may be located at an end of the movable member 51 near the pressure receiving portion 511, and a guide post 152 may be provided on the developing box cover 15 in cooperation with the guide groove 513, and when mounted, the guide post 152 is inserted into the guide groove 513, so as to guide and limit the movement of the movable member 51. Alternatively, a guide post may be provided on the movable member 51, and a guide groove may be provided on the developing cartridge cover 15 or the drive side bearing 12, to achieve the same effect. The movable member 51 can be moved in the up-down direction, and can be swung about the guide post 152, and specifically, the movable member 51 can be swung about the guide post 152 under the urging force of the development separation control unit 200 in the first swing direction and the second swing direction (opposite directions). When the movable member 51 receives the first urging force, the movable member 51 swings in the first swinging direction, and the force receiving projection 512 moves in a direction approaching the photosensitive drum; when the movable member 51 receives the second urging force, the movable member 51 swings in the second swinging direction, and the force receiving projection 512 moves in a direction away from the photosensitive drum.

As shown in fig. 2 and 3, in the present embodiment, the acting assembly is movably disposed on the developing unit and is configured to cooperate with the movable member 51 to move the developing coupling from the retracted position to the extended position when the movable member 51 receives the first force, and the developing coupling is capable of engaging with the developing drive head to receive the driving force and generate torque to drive the developing unit to move to the first position; when the movable member 51 receives the second force, the developing coupling moves from the extended position to the retracted position, the developing coupling is disengaged from the developing drive head, the rotational force disappears, the torque generated by the rotation disappears, and the developing unit moves to the second position under the force of the separation elastic member 61. Specifically, the acting assembly includes a first press ring 52, a second press ring 53, a link 54, a stopper 55, a first elastic member 36, and a second elastic member 56.

As shown in fig. 2 to 5, 12 and 13, the first pressing ring 52 and the second pressing ring 53 are sleeved outside the engaging portion 34, a convex ring 342 is provided on the outer surface of the engaging portion 34, the second pressing ring 53 abuts against the convex ring 342 to position the second pressing ring 53, the first pressing ring 52 is sleeved outside the engaging portion 34 and abuts against the side of the second pressing ring 53 away from the developing frame 11, at least one first protrusion 521 is provided on the first pressing ring 52, a first inclined surface 522 is provided on the first protrusion 521, the first inclined surface 522 faces the developing frame 11, at least one second protrusion 531 is provided on the side of the second pressing ring 53 facing away from the developing frame 11, a second inclined surface 532 is provided on the second protrusion 531, and when assembled in place, the first protrusion 521 abuts against the second protrusion 531 and the first inclined surface 522 is attached to the second inclined surface 532. In this embodiment, the number of the first protrusions 521 and the second protrusions 531 is three, and the first protrusions 521 and the second protrusions 531 are arranged at intervals in the circumferential direction, alternatively, the number of the first protrusions 521 and the second protrusions 531 may be more or less.

As shown in fig. 3, the second pressing ring 53 is further provided with a limited portion 533, the limited portion 533 is a plurality of grooves formed on the circumferential surface of the second pressing ring 53, the grooves may be circumferentially distributed on the circumferential surface of the second pressing ring 53, the developing box cover 15 is provided with a limiting portion 151 matching with the limited portion 533, the limiting portion 151 may be a protrusion or a bump, the protrusion may extend in the axial direction of the developing coupling, and when assembled, the limiting portion 151 is embedded in the limited portion 533, so that the movement of the second pressing ring 53 in the circumferential direction is limited, that is, the second pressing ring 53 cannot rotate, but can only move in the axial direction along the limiting portion 151.

As shown in fig. 4, the first press ring 52 has a first coupling portion 523 thereon, the first coupling portion 523 being a hole portion provided on a circumferential surface of the first press ring 52 for connection with the link 54 to form a driving connection.

As shown in fig. 2, 8 and 9, the connecting rod 54 is a long-strip-shaped object, the connecting rod 54 is arranged on the developing box cover 15 in a swinging way, the swinging center of the connecting rod 54 is approximately at the middle position of the connecting rod, specifically, the middle position of the connecting rod 54 is provided with a rotating shaft, the rotating shaft is rotatably arranged on the developing box cover 15 through the rotating shaft, and the rotating shaft can be a split shaft, penetrates through the connecting rod 54 and the developing box cover 15, or can be a protruding shaft integrally formed on the connecting rod 54. The upper end of the connecting rod 54 is provided with a second coupling portion 541 for matching with the first coupling portion 523, and the second coupling portion 541 is a protrusion, and the protrusion is inserted into the hole, so that the connecting rod 54 can drive the first pressing ring 52 to rotate when swinging. At least a part of the link 54 is located in the movement locus of the movable member 51, specifically, the lower end of the link 54 is located at a position that can be contacted by the movable member 51, when the movable member 51 swings under the force of the developing separation control unit 200, the movable member 51 abuts against the lower end of the link 54 and pushes the link 54 to swing around the rotation axis, and the first presser ring 52 coupled thereto is driven to rotate when the link 54 swings; when the first pressing ring 52 rotates, the first inclined surface 522 and the second inclined surface 532 contact to apply a pushing force to the second pressing ring 53, so that the second pressing ring 53 moves inwards in the axial direction, and the second pressing ring 53 contacts the convex ring 342 of the engagement portion 34, so that the engagement portion 34 is driven to move inwards in the axial direction when the second pressing ring 53 moves inwards in the axial direction.

Further, as shown in fig. 3, the first elastic member 36 is defined between the engaging portion 34 and the transmitting portion 35, specifically, the engaging portion 34 has a cavity therein, the first elastic member 36 is disposed in the cavity, and when the engaging portion 34 is assembled to the transmitting portion 35, one end of the first elastic member 36 abuts against the bottom wall of the transmitting portion 35, the other end abuts against the bottom wall of the engaging portion 34, the first elastic member 36 is configured to be expandable and contractible in the axial direction of the developing coupling, and in a state where no external force is applied, the first elastic member 36 keeps the engaging portion 34 in an outwardly extended position, that is, when the engaging portion 34 is moved inward to a retracted position by the external force, the first elastic member 36 is compressed; the first elastic member 36 is preferably a compression spring, and may be an elastic member such as elastic rubber, elastic sponge, or a spring piece.

As shown in fig. 2, 3, 6 and 9, the stopper 55 is movably disposed on the developing box cover 15, the stopper 55 is a rod-shaped member, one end of the stopper 55 is provided with a stopper 551, a middle portion of the stopper 55 is provided with a boss for swinging the stopper 55 on the developing box cover 15, the stopper 55 can move between a locking position and an unlocking position, and when in the locking position, the stopper 551 of the stopper 55 is located outside the convex ring 342 of the engaging portion 34 and abuts against the convex ring 342, so as to block the engaging portion 34 from extending outwards in the axial direction. The second elastic member 56 is defined between the stopper 55 and the developing cartridge cover 15 for holding the stopper 55 in the locking position, and specifically, the second elastic member 56 is a compression spring having one end abutting against one end of the stopper 55 where the stopper 551 is provided and disposed opposite to the stopper 551 and the other end abutting against the developing cartridge cover 15.

The second presser ring 53 is not a complete annular structure, and has a hollow portion for avoiding the stopper 55, from which the stopper 55 abuts against the collar 342 of the engagement portion 34.

The developing box cover 15 is provided with a notch portion for exposing the other end of the stopper 55 corresponding to the stopper 551, and the movable member 51 is provided with a pressing block 514, and when the movable member 51 is pressed down by the first pressing mechanism, the pressing block 514 is positioned so as to be able to contact the other end of the stopper 55 from the notch portion.

As shown in fig. 1 to 3, in the initial state, the process cartridge is in a state in which the developing roller is separated from the photosensitive drum, that is, the developing unit is held in the second position by the separating elastic member 61, the movable member 51 is not depressed, the stopper 55 is held in the locking position by the force of the second elastic member 56, the engaging portion 34 is stopped by the stopper 551, and the first elastic member 36 is in the compressed state.

As shown in fig. 7 to 9, when the process cartridge is mounted in the image forming apparatus and the image forming apparatus closes the door, the first pressing mechanism is driven to press the pressed portion 511 of the movable member 51 so that the movable member 51 as a whole moves down, the force receiving projection 512 of the movable member 51 moves to a position where it can cooperate with the development separation control unit 200, the pressing block 514 of the movable member 51 moves to a notched position where it can contact the stopper 55, but there is no force to the stopper 55, and the stopper 55 is still in the lock position.

As shown in fig. 10 to 12, when the developing operation is required, the image forming apparatus controls the developing separation control unit 200 to move in the A1 direction and abut against the force receiving projection 512, applies a first urging force (in the A1 direction) to the force receiving projection 512, moves the force receiving projection 512 so that the entire movable member 51 swings in the first swinging direction B1 (the first swinging direction B1 is clockwise as viewed from the angle of fig. 10), and when the movable member 51 swings, the push block 514 contacts the other end of the stopper 55 and pushes the stopper 55 to swing so that the stopper 55 swings from the locking position to the unlocking position, the stopper 551 is separated from the position of the collar 342 blocking the engaging portion 34, the engaging portion 34 is axially outwardly extended to the extended position under the urging force of the deformation recovery of the first elastic member 36, and simultaneously pushes the second pressing ring 53 to axially outwardly move, and the outwardly extended engaging portion 34 is capable of engaging with the developing drive head of the image forming apparatus to receive the rotational urging force; since the torque of the driving force and the force of the developing unit's own weight are much larger than the force of the separation elastic member 61 to the developing unit, the entire developing unit is rotated to the first position around the rotation center, so that the photosensitive drum is brought into contact with the developing roller, thereby enabling the developing work.

As shown in fig. 13 to 15, when the image forming apparatus finishes the developing operation, the developing drive head of the image forming apparatus stops rotating, the torque generated by the rotational force disappears, the force of the separating elastic member 61 to the developing unit is much larger than the torque of the driving force and the force of the developing unit self weight, so that the lower end of the developing unit rotates in a direction away from the photosensitive drum under the force of the separating elastic member 61, and the process cartridge returns to a state in which the developing roller is separated from the photosensitive drum. Meanwhile, the developing separation control unit 200 moves in the A2 direction (opposite to the A1 direction) under the control of the image forming apparatus, applies a second urging force to the force receiving projection 512 to move the force receiving projection 512, swings the entire movable member 51 in the second swinging direction B2 (the second swinging direction B2 is counterclockwise as viewed in the angle of fig. 13), contacts the lower end of the link 54 at the time of swinging and pushes the link 54 to swing, the link 54 thereby driving the first presser ring 52 to rotate, and when the first presser ring 52 rotates, the first inclined surface 522 moves along the second inclined surface 532, applies a urging force to the second presser ring 53, pushes the second presser ring 53 to move axially inward, the second presser ring 53 pushes the engagement portion 34 to retract axially inward, out of engagement with the developing drive head of the image forming apparatus, and the first elastic member 36 is compressed; meanwhile, when the movable member 51 swings in the second swinging direction, the pushing block 514 is away from the stopper 55, the force applied to the stopper 55 is removed, and the stopper 55 swings from the non-locking position to the locking position under the action of the second elastic member 56, so that the stopper 551 is located outside the convex ring 342 of the retracted engagement portion 34, and the engagement portion 34 is blocked from protruding. The whole acting assembly is reset under the second acting force of the developing separation control unit moving towards the direction A2, and the next working instruction of the image forming device is waited for to repeat the process.

The process cartridge of this embodiment controls the axial movement of the engaging portion 34 of the developing coupling by providing the movable member 51 and the action assembly on the developing unit, when the engaging portion 34 moves to the projecting position to receive the driving force, the developing unit is moved to the first position (the position where the developing roller contacts the photosensitive drum) by the torque generated by the rotation, and when the driving force is removed, the process cartridge moves to the second position (the position where the developing roller separates from the photosensitive drum) by the action of the torque vanishing and separating elastic member 61, so that the developing roller contacts the photosensitive drum when the image forming apparatus is in operation, the developing roller separates from the photosensitive drum when the image forming apparatus is not in operation, the problem of the deposition of toner on the photosensitive drum caused by the long-time contact of the photosensitive drum and the developing roller to pollute the photosensitive drum, and the problem of the acceleration of the deterioration of the developing roller and/or the developer due to the long-time friction of the photosensitive drum and the developing roller is avoided, and the contact/separation scheme of this embodiment is simple in structure and easy to implement, without providing the force receiving member and the holding member with complicated structure as in the prior art, the stability of the use of the process cartridge is increased, and the production cost of the process cartridge is reduced, and the service life of the process cartridge is prolonged.

What has been described above is merely some embodiments of the present utility model. It will be apparent to those skilled in the art that various modifications and improvements can be made without departing from the spirit of the utility model.

Claims

1. A process cartridge detachably mountable to an image forming apparatus, comprising:

a drum unit rotatably provided with a photosensitive drum;

2. A process cartridge according to claim 1, further comprising a separation elastic member provided between said drum unit and said developing unit for moving said developing unit from said first position to said second position.

3. A process cartridge according to claim 1 or 2, wherein an end of said developing unit is provided with a developing cap, an end of said drum unit is provided with an end cap, and said developing cap moves relative to said end cap when said developing unit moves relative to said drum unit.

4. A process cartridge according to claim 3, wherein said action assembly includes a first pressing ring, a second pressing ring, and a link, said first and second pressing rings being fitted over said engagement portion, said link being swingably provided to said developing cartridge cover and being drivingly connected to said first pressing ring, at least a portion of said link being located in a movement locus of said movable member, said movable member being movable with said link.

5. The process cartridge according to claim 4, wherein the first pressing ring is movable to push the second pressing ring.

6. The process cartridge of claim 5, wherein said first pressing ring has at least one first protrusion, said first protrusion has a first slope, said second pressing ring has at least one second protrusion, said second protrusion has a second slope, and said first slope is in contact with said second slope.

7. A process cartridge according to claim 5, wherein said developing cartridge cover is provided with a regulating portion, and said second pressing ring is provided with a regulated portion which is fitted with said regulating portion, so that said second pressing ring moves in an axial direction of the developing coupling when receiving a pressing force of said first pressing ring.

8. A process cartridge according to claim 7, wherein said movable member, upon receiving the second urging force, moves in the second swinging direction, swings said link, said link drives said first pressing ring to rotate, and said first pressing ring rotates to generate urging force to the second pressing ring to move said second pressing ring in the axial direction of the developing coupling, thereby driving said engaging portion to retract axially inward to the retracted position.

9. A process cartridge according to claim 8, wherein said action assembly further includes a first elastic member defined between the engaging portion and the transmitting portion, said first elastic member being configured to be expandable and contractible in an axial direction of the developing coupling, said first elastic member for axially outwardly extending the engaging portion to the extended position.

10. A process cartridge according to claim 9, wherein said action assembly further includes a stopper movably provided to said developing cartridge cover, said stopper being movable between a locked position and an unlocked position, when in the locked position, the stopper abutting against said engaging portion to block said engaging portion from protruding outward in the axial direction.

11. A process cartridge according to claim 10, wherein said movable member moves said stopper from the lock position to the unlock position upon receiving the first urging force in the first swing direction, and said stopper is disengaged from said engaging portion.

12. A process cartridge according to claim 10, wherein said action assembly further includes a second resilient member defined between said stopper and the developing cartridge cover for maintaining said stopper in the locked position.

13. An image forming apparatus comprising the process cartridge according to any one of claims 1 to 12.