Processing box

Abstract

The utility model provides a processing box which comprises a drum unit which comprises a photosensitive frame; a developing unit including a developing frame; the developing unit is mounted on the drum unit through a connecting part, and the developing unit can move between a contact position and a separation position relative to the drum unit around the connecting part; the limiting piece is connected with the photosensitive frame and the developing frame; under the action of self gravity of the developing unit, the developing frame swings around the connecting part and moves from the contact position to the separation position; the limiting piece is used for limiting the distance of the developing frame moving from the contact position to the separation position, so that the developing frame and the extension part on the photosensitive frame are always kept in a non-contact state, the damage caused by rigid collision between the developing frame and the photosensitive frame is prevented, and the service life of the processing box can be effectively prolonged.

Description

TECHNICAL FIELD

[0001] The utility model relates to electronic imaging technical field, concretely relates to a processing box. BACKGROUND

[0002] Electronic imaging devices form images on recording materials (such as paper) using electrophotographic image forming processes. Examples of electronic imaging devices include electrophotographic copiers, electrophotographic printers, facsimile machines, word processors, and the like. A cartridge includes at least one of an electrophotographic photosensitive drum as a photosensitive member and a developing member (such as a developing roller) capable of acting on the drum, and the photosensitive member and the developing member can be integrally configured as a cartridge (which can be referred to as a process cartridge) detachably mounted into an electronic imaging device. A frame including the photosensitive member in the process cartridge is a photosensitive frame, and a frame including the developing member is a developing frame.

[0003] During operation of the electronic imaging device, the developing roller contacts and presses the photosensitive drum, and the developer on the developing roller is transferred to the surface of the photosensitive drum on which a specific latent electrostatic image is formed, thereby completing the developing process. However, when the developing roller contacts the photosensitive drum during non-operation of the electronic imaging device, the developer carried on the developing roller is unnecessarily deposited to the photosensitive drum, and such developer is deposited on the recording material, which results in contamination of the recording material. In addition, as the photosensitive drum and the developing roller rub against each other for a long time, the developing roller and / or the developer can be deteriorated. The above problems can occur regardless of whether an elastic layer is provided on the surface of the developing roller. Therefore, it is necessary to separate the photosensitive drum from the developing roller during non-development operation of the electronic imaging device to extend the service life of the photosensitive drum and the developing roller. The process cartridge of the related art separates by relying on the self-weight of the developing frame. During the separation process, the weight of the toner in the developing frame changes with the amount of toner used, and thus the degree of difficulty of separation by relying on the self-weight of the developing frame changes. The speed and stability of separation of the drum roller can be affected by the reduction of the amount of toner. In addition, when the process cartridge has a large amount of toner, the mass of the developing cartridge is large, and thus a rigid collision between structures occurs when the process cartridge is separated by relying on the self-weight. Over a long period of time, the process cartridge can be damaged due to wear of components. SUMMARY

[0004] In view of the above problems in the prior art, the purpose of the present utility model is to provide a process cartridge to solve the above problems.

[0005] The above technical purpose of the utility model is realized through the following technical scheme: a processing box, which is detachably installed in an image forming device, comprises: a drum unit, the drum unit comprises a photosensitive frame, the photosensitive frame rotatably supports a photosensitive drum, and the photosensitive drum extends along a first direction; a developing unit, the developing unit comprises a developing frame, the developing frame rotatably supports a developing roller, and the developing roller extends along the first direction; the developing frame is further rotatably provided with a fixed developing driving head, is used for receiving driving force from the image forming device, and the driving force is used for driving the developing roller to rotate at least; the developing unit is installed on the drum unit through a connecting part, and the developing unit can move between a contact position and a separation position relative to the drum unit around the connecting part; characterized by further comprising: a limiting piece, the limiting piece is connected with the photosensitive frame and the developing frame; wherein under the action of self-gravity, the developing frame swings around the connecting part, and moves from the contact position to the separation position; wherein the limiting piece is used for limiting the distance of movement of the developing frame from the contact position to the separation position.

[0006] In one embodiment, the limiting piece is a tensile elastic piece.

[0007] In one embodiment, during the movement of the developing unit to the separation position, the pulling force of the tensile elastic piece gradually increases, and when the pulling force of the tensile elastic piece offsets the self-gravity of the developing unit, the movement of the developing unit stops.

[0008] In one embodiment, the photosensitive frame is provided with a first connecting column, the developing frame is provided with a second connecting column, and the tensile elastic piece is connected between the first connecting column and the second connecting column.

[0009] In one embodiment, the first connecting column is provided with a first locking portion, the second connecting column is provided with a second locking portion, and the two ends of the tensile elastic piece are connected in the first locking portion and the second locking portion respectively.

[0010] In one embodiment, when the developing unit is in the contact position, the distance between the first connecting column and the second connecting column is D3; the length of the tensile elastic piece under no external force is D4, and D3>D4.

[0011] In one embodiment, the tensile elastic piece is one of a tension spring, an elastic rubber band or an elastic rubber ring.

[0012] In one embodiment, the photosensitive frame is provided with an extension.

[0013] In one embodiment, when the developing roller is in contact with the photosensitive drum, the distance between the developing frame and the extension part in the direction of gravity is D1; when the developing roller is separated from the photosensitive drum under the action of gravity, the distance between the developing frame and the extension part in the direction of gravity is D2, D1>D2.

[0014] In one embodiment, the limiting piece is specifically a compression elastic piece; the limiting piece is in contact between the developing frame and the extension part.

[0015] In one embodiment, during the movement of the developing unit along the separation direction, the supporting force of the compression elastic piece gradually increases, and when the supporting force of the compression elastic piece offsets the gravity of the developing unit, the movement of the developing unit stops.

[0016] In one embodiment, the limiting piece is specifically a compression spring.

[0017] In one embodiment, the limiting piece is provided with a positioning assembly; one end of the compression spring is fixed on the positioning assembly.

[0018] In one embodiment, the positioning assembly is specifically a positioning column, and one end of the compression spring is sleeved on the positioning column.

[0019] In one embodiment, the positioning assembly is specifically a positioning slot, and one end of the compression spring is inserted into the inside of the positioning slot.

[0020] In one embodiment, the limiting piece is a local rotation structure, one end of the local rotation structure is rotationally connected with the photosensitive frame, and the other end of the local rotation structure is rotationally connected with the developing frame; when the developing frame swings around the connecting part to a predetermined position under the action of gravity, the local rotation structure generates a pulling force to offset the gravity of the developing unit, and the movement of the developing unit stops.

[0021] In one embodiment, the local rotation structure is specifically a double-rod rotation structure, when the developing roller is in contact with the photosensitive drum, the two rod parts of the limiting piece rotate relative to each other to form a folded shape; when the developing frame swings around the connecting part under the action of gravity, the two rod parts of the limiting piece rotate until the limiting piece forms a straight rod shape, and the movement of the developing unit stops.

[0022] In summary, the utility model has the following beneficial effects: the processing box of the application sets the limiting piece between the photosensitive frame and the developing frame, so that the developing frame can normally drive the developing roller and the photosensitive drum to abut after receiving the thrust of the image forming device, after the image forming device cancels the thrust, the developing frame swings around the connecting part under the gravity to drive the developing roller and the photosensitive drum to separate, at this time, the limiting piece can limit the swing amplitude of the developing frame, so that the developing frame and the extension part keep a spacing, that is, the developing frame and the extension part always keep the state of not contacting, thereby preventing rigid collision between the developing frame and the extension part and causing damage, and effectively prolonging the service life of the processing box. BRIEF DESCRIPTION OF DRAWINGS

[0023] Figure 1 It is a structural schematic view of the processing box of the utility model;

[0024] Figure 2 It is a structural schematic view of the drum unit in the utility model;

[0025] Figure 3 It is a structural schematic view of the developing unit after the developing frame is opened in the utility model;

[0026] Figure 4 It is a position schematic view of the gear assembly of the developing unit at the non-driving end in the utility model;

[0027] Figure 5 It is a structural schematic view of the driving end of the processing box in the utility model;

[0028] Figure 6 It is Figure 5 It is an enlarged view of part A in the utility model;

[0029] Figure 7 It is a structural schematic view of the developing unit after swinging under the gravity in the utility model;

[0030] Figure 8 It is a schematic view of the limiting piece being a compression elastic piece in the utility model;

[0031] Figure 9 It is a schematic view of the limiting piece being a local rotation structure in the utility model.

[0032] In the figure: 100 - process cartridge, 101 - driving end, 102 - non-driving end, 103 - connecting part, 1 - drum unit, 2 - developing unit, 11 - photosensitive frame, 12 - photosensitive drum, 13 - charging roller, 11a - waste powder bin, 14 - drum driving head, 21 - developing frame, 22 - developing bearing, 221 - force receiving part, 23 - developing roller, 26 - fixed developing driving head, 28 - stirring frame, 21a - powder bin, 41 - powder feeding gear, 42 - developing gear, 43 - transmission gear, 44 - idler, 45 - stirring gear, 5 - limiting piece, 15 - extension, 16 - first connecting column, 17 - first locking part, 211 - second connecting column, 212 - second locking part. DETAILED DESCRIPTION

[0033] In order to make the purpose, technical scheme and advantages of the embodiments of the present application more clear, the technical scheme in the embodiments of the present application will be described clearly and completely below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the present application.

[0034] It should be noted that the terms "first" and "second" are only used for description purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined with "first" and "second" can explicitly or implicitly include at least one of the features. In the description of the present application, the meaning of "multiple" is at least two, such as two, three, etc., unless otherwise explicitly specified.

[0035] The present application relates to a kind of process cartridge, it is detachably installed in image forming device, image forming device includes, for example, electronic photocopier, electronic photocopier printer (LED printer, laser printer etc.), electronic photocopier printer type facsimile machine etc..Process cartridge includes photosensitive member, for developing formation and with photosensitive member electrostatic latent image developing member etc..Image forming device includes driving force transmission unit, driving force transmission unit is used to transmit the driving force of image forming device to process cartridge, so that process cartridge works.

[0036] The present application will be described in further detail below in conjunction with the drawings.

[0037] Figure 1 A process cartridge 100 according to an embodiment of the present application is schematically shown. For the convenience of description, a three-axis coordinate system is established,

[0038] A direction in which X1 and X2 are located is a first direction, wherein the X1 direction is a positive direction of the first direction, and the X2 direction is a negative direction of the first direction.

[0039] A direction in which Y1 and Y2 are located is a second direction, wherein the Y1 direction is a positive direction of the second direction, and the Y2 direction is a negative direction of the second direction.

[0040] A direction in which Z1 and Z2 are located is a third direction, wherein the Z1 direction is a positive direction of the third direction, and the Z2 direction is a negative direction of the third direction. The negative direction of the third direction is a direction of gravity, and an end of the direction of gravity is a lower side.

[0041] Figure 7 A processing cartridge 100 of an embodiment of the present application is schematically shown. For the convenience of description, the swinging direction of the developing unit 2 is limited. The clockwise swinging of the developing unit around the connecting portion is a separation direction, that is, the R1 direction in the figure, and the counterclockwise swinging of the developing unit around the connecting portion is a contact direction, that is, the R2 direction in the figure.

[0042] The first direction, the second direction, and the third direction intersect each other.

[0043] An electronic image forming apparatus forms an image on a recording material using, for example, an electrophotographic image forming process. The electronic image forming apparatus includes, for example, an electrophotographic copying machine, an electrophotographic printer (LED printer, laser printer, and the like), a facsimile machine of an electrophotographic printer type, and the like. A processing cartridge is detachably installed in the electronic image forming apparatus, and the processing cartridge 100 contains a photosensitive drum 12, a developing roller 23 for developing an electrostatic latent image formed on the photosensitive drum 12, and the like. The electronic image forming apparatus includes a drive head for transmitting a driving force of the electronic image forming apparatus to the processing cartridge 100 to operate the processing cartridge 100.

[0044] As shown in FIG. 1, Figure 1 The processing cartridge 100 includes a drum unit 1, a developing unit 2, and a limiting member 5. The processing cartridge 100 has a driving end 101 and a non-driving end 102 in a first direction.

[0045] As shown in FIG. 1, Figure 2As shown, the drum unit 1 includes a photosensitive frame 11, a photosensitive drum 12, and a charging roller 13. The photosensitive frame 11 has an open frame structure, and the photosensitive frame 11 has a waste powder tank 11a for collecting residual developer that is not transferred on the photosensitive drum 12. The photosensitive drum 12 is rotatably supported at both ends of the photosensitive frame 11 in a first direction, and the waste powder tank 11a is located at one side of the photosensitive drum 12. The charging roller 13 is used to uniformly charge the surface of the photosensitive drum 12, so that the photosensitive drum 12 can adsorb toner. In a third direction, the charging roller 13 is located on the lower side of the photosensitive drum 12 (negative direction of the third direction), and the charging roller 13 is in contact with the outer peripheral surface of the photosensitive drum 12 to uniformly charge the outer peripheral surface of the photosensitive drum 12. The photosensitive drum 12 is coaxially provided with a drum driving head 14 exposed outside the end face of the photosensitive frame 11 in the positive direction of the first direction, for receiving the driving force of the image forming device to rotate the photosensitive drum 12. The axial direction of the photosensitive drum 12 and the charging roller 13 is parallel to the first direction.

[0046] As Figure 3As shown, the developing unit 2 is mounted on the drum unit 1 via a connecting part 103. The connecting part 103 can be a pin or a fixing pin, etc. The connecting part 103 allows the developing unit 2 to be rotatably connected to the drum unit 1, that is, the connecting part 103 serves as the fulcrum for the swing of the developing unit 2. The developing unit 2 includes a developing frame 21, a developing bearing 22, a developing roller 23, a powder feeding roller (not shown), a fixed developing drive head 26, a stirring frame 28 installed in the powder hopper, and a drive gear set. The fixed developing drive head 26 is fixedly mounted on the developing frame 21 and can only rotate around its axis, and cannot achieve radial swing. The developing frame 21 forms a powder hopper 21a for storing toner. The developing frame 21 is approximately rectangular in shape. The developing frame 21 and the photosensitive frame 11 have matching through-hole structures at corresponding positions and are connected by the connecting part 103. The developing frame 21 can swing around the mounting position of the connecting part 103. The developing bearing 22 is disposed on both sides of the developing frame 21 in the first direction. The toner feeding roller, developing roller 23, and stirring frame 28 are rotatably supported on the developing bearing 22. The toner feeding roller can output toner to the developing roller 23. The developing roller 23 can abut against the photosensitive drum 12. When the developing frame 21 swings to the contact position, the developing roller 23 abuts against the photosensitive drum 12. When the developing frame 21 swings to the separation position, the developing roller 23 separates from the photosensitive drum 12. The axial directions of the toner feeding roller, developing roller 23, and stirring frame 28 are all parallel to the first direction. The stirring frame 28 is disposed in the toner hopper 21a. The toner in the toner hopper 21a is stirred by the stirring frame 28 to prevent the toner in the toner hopper 21a from clumping. At the same time, it can also convey toner towards the developing roller 23, where it is attracted by the charged developing roller 23. The powder feeding roller is coaxially fixed with a fixed developing drive head 26 on the positive side of the first direction, which is used to receive the driving force of the image forming apparatus to make the powder feeding roller rotate. The powder feeding roller drives the developing roller 23 and the stirring frame 28 to rotate on the negative side of the first direction through a drive gear set.

[0047] like Figure 4 As shown, the drive gear set is located on the non-drive end 102 and exposed on the developing bearing 22. The drive gear set includes a powder feeding gear 41, a developing gear 42, a transmission gear 43, an idler gear 44, and a stirring gear 45. The powder feeding gear 41 is coaxially mounted on the powder feeding roller, and the developing gear 42 is coaxially mounted on the developing roller 23. The idler gear 44 has two different rotating tooth diameters. The transmission gear 43 meshes with the powder feeding gear 41, the developing gear 42, and the idler gear 44 respectively. The idler gear 44 meshes with the stirring gear 45. The power received by the fixed developing drive head 26 can be transmitted to the powder feeding gear 41. The powder feeding gear 41 rotates to drive the transmission gear 43 to rotate, thereby causing the developing gear 42 and the idler gear 44 to rotate. The rotation of the idler gear 44 drives the stirring gear 45 to rotate. Therefore, the fixed developing drive head 26 receives driving force to rotate the powder feeding roller, and the powder feeding roller drives the developing roller 23 and the stirring frame 28 to rotate through the drive gear set.

[0048] The positive direction side of the first direction of the developing frame 21 is also provided with a force receiving part 221 exposed on the developing frame 21, which can receive the pushing force from the push rod of the image forming device to drive the developing frame 21 to swing around the connecting part 103, and further make the developing roller 23 abut against the photosensitive drum 12, so that the developing roller 23 abuts against the photosensitive drum 12 after being electrified and forms a potential difference through relative rotation, and the developing roller 23 and the photosensitive drum 12 realize electrostatic latent image development and imaging. The structure of the process cartridge 100 not mentioned above can refer to the prior art. In the third direction, the force receiving part 221 is located on the positive direction side of the third direction, and the connecting part 103 is located on the negative direction side of the third direction. By increasing the length of the force arm, the requirement for the size of the pushing force is reduced.

[0049] It should be noted that, as shown in Figure 5 The photosensitive frame 11 is also provided with an extension part 15 located on the positive direction side of the first direction of the photosensitive frame 11, which is designed in one piece with the photosensitive frame 11. In the third direction, the extension part 15 coincides or partially coincides with the projection of the developing frame 21, and the extension part 15 is closer to the negative direction of the third direction of the developing frame 21. The extension part 15 is used to limit the excessive swing of the developing frame 21, so as to limit the swing amplitude of the developing frame 21. For example, after the pushing force of the image forming device is removed, the force receiving part 221 is not pushed by external force, and the developing unit 2 swings around the connecting part 103 under the action of gravity, so that the developing roller 23 and the photosensitive drum 12 are separated. Generally, the developing frame 21 abuts against the extension part 15 to block the swing range of the developing frame 21, but the abutment between the developing frame 21 and the extension part 15 is rigid contact, which is easy to cause wear between the developing frame 21 and the extension part 15, and is not conducive to the service life of the process cartridge.

[0050] To solve the above problems, the process cartridge of the present application further comprises a limiting part 5 connected with the photosensitive frame 11 and the developing frame 21. When the developing frame 21 swings around the connecting part 103 to drive the developing roller to abut against or separate from the photosensitive drum, the limiting part 5 can be deformed, and the types of deformation include stretching action, local rotation, bending, etc. The stretching action of the limiting part 5 when deformed is taken as an example. The limiting part 5 is preferably a tensile elastic part, such as a tension spring, a rubber band or a rubber ring. When the limiting part 5 is a tension spring, the tension spring has two ends in a ring shape, which are connected to the photosensitive frame 11 and the developing frame 21 respectively, so that the limiting part 5 is elastically connected with the photosensitive frame 11 and the developing frame 21.

[0051] The tension spring of the embodiment mainly provides tension to the developing frame 21. The tension spring is located at the upper side (positive direction of the third direction) of the connecting portion 103, and is exposed to the positive direction side of the first direction of the process cartridge 100. Compared with the force receiving portion 221, the tension spring is closer to the positive direction side of the third direction of the process cartridge 100, and the swing radius between the connecting portion 103 is longer, so the tension provided by the tension spring to the developing frame 21 is more significant. As shown in Figure 6 In order to facilitate the installation of the tension spring, the photosensitive frame 11 is provided with a first connecting column 16, and the developing frame 21 is provided with a second connecting column 211. The first connecting column 16 and the second connecting column 211 are both protruding columnar structures along the positive direction of the first direction, and the two ends of the tension spring can be connected to the first connecting column 16 and the second connecting column 211 respectively. In order to avoid the tension spring from slipping off or shifting, the first connecting column 16 is provided with a first locking portion 17, and the second connecting column 211 is provided with a second locking portion 212. The first locking portion 17 and the second locking portion 212 are both recessed structures, and the two ends of the tension spring can be clamped in the first locking portion 17 and the second locking portion 212 respectively, so as to limit the tension spring from being separated from the outside of the developing frame 21 and the photosensitive frame 11. Of course, the first locking portion 17 and the second locking portion 212 can also be provided as protruding structures, or as limiting hole structures, which can limit the annular structure of the two ends of the tension spring. Therefore, when the developing roller 23 abuts against the photosensitive drum 12, the tension spring is in a normal state or a weakly stretched state, and the tension generated thereby is less than the weight force of the developing unit 2. When the developing roller 23 is separated from the photosensitive drum 12, as the length of the tension spring becomes longer, the elastic force generated thereby increases, and after the elastic force is equal to the weight force of the developing unit 2, the developing unit 2 can be limited to continue to move.

[0052] If the tension elastic member is an elastic rubber band or an elastic rubber ring, the positioning of the tension elastic member can also be achieved by using the locking portions on the two connecting columns. For example, when the locking portion is a recess, the two ends of the rubber band can be wound in the recesses of the connecting columns. When the locking portion is a protruding structure, the two ends of the rubber band can be wound on the connecting columns, and in the first direction, the winding position is located on the negative direction side of the protruding structure, so as to avoid the winding position from falling off the connecting column. When the locking portion is a limiting hole structure, the two ends of the rubber band can pass through the two limiting holes respectively to achieve stable connection.

[0053] Since the two ends of the tension spring are annular structures, when the developing unit is in the contact position, the distance between the first connecting column 16 and the second connecting column 211 is the smallest, which is recorded as D3. In order to avoid the two ends of the tension spring from being no longer forced to fall off the connecting column, it is necessary to try to keep the two ends of the tension spring always under tension to maintain the stability of the installation of the tension spring. Therefore, if the length of the tension spring in the natural state without external force is recorded as D4, there is D3>D4.

[0054] As shown in Figure 7As shown, in the second direction, the straight line containing the axis of the photosensitive drum 12 is denoted as L1; the straight line containing the axis of the fixed developing drive head 26 is denoted as L2; ​​the limiting member 5 is located between the straight lines L1 and L2, and connects the developing frame 21 and the photosensitive frame 11 to achieve the limiting.

[0055] like Figure 7 As shown, after the image forming apparatus removes the thrust applied to the force receiving unit 221, the developing frame 21 swings around the connecting part 103 in the separation direction (clockwise) under its own weight, and drives the developing roller 23 to separate from the photosensitive drum 12. The limiting member 5 can apply a pulling force to the developing frame 21 to limit the swing amplitude of the developing frame 21, that is, limit the distance that the developing frame 21 moves toward the extension part 15, so that there is a gap between the developing frame 21 and the extension part 15. That is, when the developing frame 21 swings under its own weight, it can normally separate the developing roller 23 and remain in a non-contact state with the extension part 15. In addition, the elastic pulling force of the limiting member 5 can also provide a buffering and shock absorption effect for the developing frame 21, which can effectively avoid the problem of rigid contact between the developing frame 21 and the extension part 15.

[0056] Furthermore, the force receiving unit 221 receives the thrust of the image forming apparatus, causing the developing roller 23 to come into contact with the photosensitive drum 12. At this time, the distance between the developing frame 21 and the extension 15 in the third direction is denoted as D1. When the image forming apparatus removes the thrust applied to the force receiving unit 221, the developing frame 21 swings under its own weight and drives the developing roller 23 to separate. The limiting member 5 generates a pulling force on the developing frame 21, restricting the developing frame 21 from contacting the extension 15. During this process, the distance between the developing frame 21 and the extension 15 in the direction of gravity is denoted as D2. It can be seen that D1>D2, and since the developing frame 21 and the extension 15 will not be in complete contact, D2>0.

[0057] Therefore, by using the limiting member 5 to ensure that when the developing frame 21 swings under its own weight, the limiting member 5 can offset part of the weight of the developing frame 21, and the developing frame 21 and the extension 15 can still maintain a hollowed-out gap, that is, the developing frame 21 and the extension 15 will not make rigid contact, and the normal drum roller separation action of the processing cartridge 100 can be realized. The photosensitive frame 11 and the developing frame 21 will not collide and cause wear, which can effectively extend the service life of the processing cartridge 100.

[0058] In some embodiments, such as Figure 8As shown, the limiting member 5 can also be a compression elastic member, for example, the limiting member 5 is configured as a compression spring, and the limiting member 5 is elastically connected with the photosensitive frame 11 and the developing frame 21, in the embodiment, the limiting member 5 is located at the third direction negative side of the connecting portion 103, preferably, the limiting member 5 abuts between the developing frame 21 and the extension portion 15, the compression spring can provide elastic support force for the developing frame 21, for example, after the image forming device cancels the pushing force applied to the force receiving portion 221, the developing frame 21 swings around the connecting portion 103 under the gravity, the developing roller 23 is separated from the photosensitive drum 12, at this time, the developing frame 21 abuts with the limiting member 5 to limit the swing range of the developing frame 21, the limiting member 5 applies elastic support force to the developing frame 21 by the elastic force generated by compression, avoiding the developing frame 21 from contacting and colliding with the extension portion 15. Further, the extension portion 15 is provided with a positioning assembly (not shown in the figure), which can be a positioning column or a positioning groove, when the positioning column structure is used, one end of the limiting member 5 can be inserted on the positioning column to avoid the movement or disengagement of the limiting member 5, when the positioning assembly is the positioning groove, the bottom end of the limiting member 5 is inserted in the positioning groove, which can achieve the same effect.

[0059] In some embodiments, as Figure 9 As shown, the limiting member 5 can also be provided as a partial rotation structure, mainly providing pulling force to the developing frame 21, for example, the limiting member 5 can adopt a double-rod rotation structure, the two rod portions of the limiting member 5 can rotate relative to each other to complete deformation, when the image forming device applies pushing force to the force receiving portion 221, the two rod portions of the limiting member 5 rotate relative to each other to form a folded shape, so that the developing frame 21 can drive the developing roller 23 to abut with the photosensitive drum 12, when the developing frame 21 swings around the connecting portion 103 under the gravity, the developing roller 23 is separated from the photosensitive drum 12, the two rod portions of the limiting member 5 rotate until the limiting member 5 forms a straight rod shape, the limiting member 5 generates pulling force to the developing frame 21 to limit the swing range of the developing frame 21, avoiding the developing frame 21 from rigidly contacting with the extension portion 15.

[0060] The above is only a preferred embodiment of the present application, in order to make the description simple, all possible combinations of the technical features in the above embodiments are not described, and the present application is not limited in any form, therefore, any modification, equivalent change and modification of the above embodiments according to the technical essence of the present application, all still belong to the scope of the technical scheme of the present application.

Claims

1. A processing cartridge detachably installed in an image forming apparatus, comprising: a drum unit including a photosensitive frame rotatably supporting a photosensitive drum extending along a first direction; a developing unit including a developing frame rotatably supporting a developing roller extending along the first direction, the developing frame further rotatably provided with a fixed developing driving head for receiving a driving force from the image forming apparatus, the driving force at least for driving the developing roller to rotate; the developing unit being mounted on the drum unit through a connecting portion, the developing unit being movable relative to the drum unit about the connecting portion between a contact position and a separation position; characterized in further comprising: a limiting member connected with the photosensitive frame and the developing frame; wherein the developing unit is moved from the contact position to the separation position under the action of a self-gravity of the developing unit, the developing frame swinging about the connecting portion; wherein the limiting member is for limiting a distance of the developing frame moved from the contact position to the separation position.

2. A process cartridge according to Claim 1 wherein, the limiting member is a tensile elastic member.

3. A process cartridge according to claim 2 wherein, during the movement of the developing unit to the separation position, a tension of the tensile elastic member gradually increases, when the tension of the tensile elastic member offsets the self-gravity of the developing unit, the developing unit stops moving.

4. A process cartridge according to Claim 2 wherein, the photosensitive frame is provided with a first connecting post, the developing frame is provided with a second connecting post, the tensile elastic member is connected between the first connecting post and the second connecting post.

5. A process cartridge according to claim 4 wherein, the first connecting post is provided with a first locking portion, the second connecting post is provided with a second locking portion, two ends of the tensile elastic member are respectively connected in the first locking portion and the second locking portion.

6. A process cartridge according to claim 5 wherein, when the developing unit is in the contact position, a distance between the first connecting post and the second connecting post is D3; a length of the tensile elastic member when not subjected to external force is D4, D3>D4.

7. A process cartridge as claimed in any one of claims 2 to 6 wherein, the tensile elastic member is one of a tension spring, an elastic rubber band or an elastic rubber ring.

8. A process cartridge according to claim 1, wherein the photosensitive frame is provided with an extension.

9. A process cartridge according to claim 8 characterized in that, when the developing roller abuts against the photosensitive drum, a distance between the developing frame and the extension in a direction of gravity is D1; when the developing roller is separated from the photosensitive drum under the action of the self-gravity, a distance between the developing frame and the extension in the direction of gravity is D2, D1>D2.

10. A process cartridge according to claim 8, wherein, the limiting member is a compression elastic member, and the limiting member abuts between the developing frame and the extension.

11. A process cartridge according to claim 10 wherein, during the movement of the developing unit along the separation direction, a support force of the compression elastic member gradually increases, when the support force of the compression elastic member offsets the self-gravity of the developing unit, the developing unit stops moving.

12. A process cartridge according to claim 11, wherein, the limiting member is specifically a compression spring.

13. A process cartridge according to claim 12, wherein, the limiting member is provided with a positioning assembly; one end of the compression spring is fixed on the positioning assembly.

14. A process cartridge according to claim 13, wherein, the positioning assembly is specifically a positioning post, one end of the compression spring is sleeved on the positioning post.

15. A process cartridge according to claim 13, wherein, the positioning assembly is specifically a positioning slot, one end of the compression spring is inserted into the inside of the positioning slot.

16. A process cartridge according to claim 1, wherein The limiting piece is a partial rotating structure, one end of the partial rotating structure is rotatably connected with the photosensitive frame, and the other end of the partial rotating structure is rotatably connected with the developing frame; when the developing frame swings around the connecting portion under the self-gravity to a predetermined position, the partial rotating structure generates a pulling force to offset the self-gravity of the developing unit, and the developing unit stops moving.

17. A process cartridge according to claim 16, wherein, The partial rotating structure is specifically a double-rod rotating structure, when the developing roller abuts against the photosensitive drum, the two rod portions of the limiting piece rotate relative to each other to form a folded shape; when the developing frame swings around the connecting portion under the self-gravity, the two rod portions of the limiting piece rotate until the limiting piece forms a straight rod shape, and the developing unit stops moving.

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