Developing cartridge and frame manufacturing method

Abstract

To provide technology for easily manufacturing a housing having a rib to cover a separation shaft.SOLUTION: A housing 10 of a developing cartridge 1 has a first groove 17, a second groove 18, and a rib 19 on an outer surface 151. The first groove 17 extends in a first direction. A separation shaft 63 is disposed in the first groove 17. The first groove 17 has a first edge in a second direction and a second edge separated from the first edge in the second direction. The rib 19 extends in the second direction from the first edge toward the separation shaft 63. The rib 19 covers part of the separation shaft 63. The second groove 18 extends from the second edge of the first groove 17 in a bearing to separate from the rib 19 in the second direction. The second groove 18 includes a portion located at a same position as the rib 19 in the first direction. When manufacturing the housing 10, the rib 19 is molded by extracting a slide core along the second groove 18.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present disclosure relates to a method of manufacturing a developer cartridge and a frame. [Background technology]

[0002] 2. Description of the Related Art Conventionally, electrophotographic image forming apparatuses such as laser printers, LED printers, etc. are known. A conventional image forming apparatus is described in, for example, Patent Document 1.

[0003] The image forming apparatus of Patent Document 1 includes a developing cartridge and a drum unit. The developing cartridge includes a developing roller. The drum unit includes a photosensitive drum. When the developing cartridge is attached to the drum unit, the developing roller comes into contact with the photosensitive drum.

[0004] Moreover, the developer cartridge of Patent Document 1 has a spacing member. The spacing member has a shaft. When the image forming apparatus presses the shaft in the axial direction while the developer cartridge is attached to the drum unit, the spacing member moves in the axial direction relative to the housing of the developer cartridge. Then, the spacing member comes into contact with the frame of the drum unit, and the developer cartridge moves in the spacing direction relative to the drum unit. As a result, the developer roller can be separated from the photosensitive drum. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2019-179128 A Summary of the Invention [Problem to be solved by the invention]

[0006] In the above structure, if the separation shaft is bent when the image forming apparatus presses the separation shaft, it becomes difficult to separate the developing roller from the photosensitive drum. Therefore, in order to suppress the bending of the separation shaft, it is conceivable to provide a rib on the housing that covers a part of the separation shaft. However, if a rib that covers a part of the separation shaft is provided on the frame of the housing, it becomes difficult to mold the frame.

[0007] An object of the present disclosure is to provide a technique for easily manufacturing a housing having ribs covering spaced shafts. [Means for solving the problem]

[0008] The first disclosure comprises a housing capable of containing toner, a developing roller rotatable about a developing axis extending in a first direction, the developing roller being located at one end of the housing in a second direction intersecting the first direction, and a spaced shaft movable in the first direction relative to the housing, wherein the housing has an outer surface extending in the first direction and the second direction, the outer surface having a first groove extending in the first direction and in which the spaced shaft is disposed, the first groove having a first edge in the second direction and a second edge away from the first edge in the second direction, a rib extending in the second direction from the first edge toward the spaced shaft and covering a portion of the spaced shaft, and a second groove including a portion located at the same position as the rib in the first direction, the second groove extending from the second edge in a direction away from the rib in the second direction.

[0009] The second disclosure is the developing cartridge of the first disclosure, characterized in that the second groove is passed through by a sliding core serving as a mold for molding the rib when the sliding core is opened in the second direction during manufacturing of the housing.

[0010] A third disclosure is the developing cartridge according to the first or second disclosure, characterized in that a width of the second groove in the first direction is larger than a width of the rib in the first direction.

[0011] A fourth disclosure is a developing cartridge according to any one of the first to third disclosures, characterized in that the second edge is closer to the developing roller than the first edge, the rib extends in the second direction from the first edge toward the second edge, and the second groove extends in the second direction from the second edge toward the developing roller.

[0012] A fifth disclosure is a developing cartridge according to any one of the first to fourth disclosures, wherein the first groove has a convex portion protruding in a third direction intersecting the first direction and the second direction.

[0013] A sixth disclosure is the developing cartridge of the fifth disclosure, characterized in that the first groove has a first convex portion that is the convex portion, and a second convex portion that is the convex portion and is positioned away from the first convex portion in the first direction.

[0014] A seventh disclosure is the developing cartridge of the sixth disclosure, wherein the second groove is positioned between the first convex portion and the second convex portion in the first direction.

[0015] An eighth disclosure is a developing cartridge according to any one of the first to seventh disclosures, characterized in that the housing has a boss protruding from the outer surface in a third direction intersecting the first direction and the second direction, and the second groove is located at a position different from the boss in the first direction.

[0016] A ninth disclosure is the developing cartridge according to the eighth disclosure, wherein the boss is cylindrical and extends in the third direction, and has a screw groove on its inner surface.

[0017] A tenth disclosure is the developing cartridge of the ninth disclosure, further comprising a blade that contacts the outer peripheral surface of the developing roller and a screw that fixes the blade to the housing, the screw being inserted into the screw groove.

[0018] An eleventh disclosure is a developing cartridge according to any one of the first to tenth disclosures, characterized in that the spacing shaft has a recess that penetrates the spacing shaft in a third direction that intersects the first direction and the second direction, and the length of the recess in the first direction is greater than that of the rib.

[0019] A twelfth disclosure is the developing cartridge according to any one of the first to eleventh disclosures, characterized in that the spaced shaft is made of resin.

[0020] The thirteenth disclosure is a manufacturing method for a frame including the outer surface used in the housing of a developing cartridge of any one of the first to twelfth disclosures, comprising: a) a step of pouring molten resin into a cavity in a mold formed by a first core, a second core movable in a third direction intersecting the first direction and the second direction relative to the first core, and a sliding core movable in the second direction relative to the first core and the second core; b) a step of forming the frame by hardening the resin in the mold; and c) a step of removing the frame from the mold by opening the second core in the third direction relative to the first core and opening the sliding core in the second direction relative to the first core and the second core through the second groove, wherein at least a portion of the rib is molded by the sliding core. Effect of the Invention

[0021] According to the first to thirteenth disclosures, when the housing is manufactured, the slide core is removed along the second groove to form the rib, which makes it easy to manufacture the housing having the rib.

[0022] Furthermore, according to the fifth disclosure, even if burrs are generated on the parting line of the first groove during molding of the housing, the separation shaft can be prevented from coming into contact with the burrs.

[0023] Moreover, according to the sixth disclosure, the position of the separated shaft can be stabilized by supporting the separated shaft with the protrusions at two locations.

[0024] Moreover, according to the eleventh disclosure, the spaced shaft can be disposed in the first groove with the recess overlapping the rib. [Brief description of the drawings]

[0025] [Figure 1] FIG. 1 is a schematic diagram of an image forming apparatus. [Diagram 2] FIG. [Diagram 3] FIG. [Figure 4] 4 is a cross-sectional view of the developing cartridge taken along line AA in FIG. 3. [Diagram 5] FIG. 2 is a perspective view of a first frame. [Figure 6] 4 is a cross-sectional view of the first frame taken along line BB in FIG. 3. [Figure 7] 4 is a cross-sectional view of the drum unit with the developing cartridge mounted thereon, including a spacing member. FIG. [Figure 8] 4 is a cross-sectional view of the drum unit with the developing cartridge mounted thereon, including a spacing member. FIG. [Figure 9] 10 is a flowchart showing a manufacturing procedure of the first frame. [Figure 10] FIG. 4 is a diagram showing a state of the first frame during manufacturing. [Figure 11] FIG. 4 is a diagram showing a state of the first frame during manufacturing. [Figure 12] FIG. 4 is a diagram showing a state of the first frame during manufacturing. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0026] Hereinafter, embodiments of the present disclosure will be described with reference to the drawings.

[0027] In the following, the direction in which the development shaft of the development roller 30 extends is referred to as the "first direction." Also, the direction in which one end of the housing 10 of the development cartridge 1 where the development roller 30 is located is aligned with the other end of the housing 10 is referred to as the "second direction." Also, the direction in which the second core 92 moves during the manufacture of the housing 10 is referred to as the "third direction."

[0028] The first direction and the second direction intersect with each other. For example, the first direction and the second direction are perpendicular to each other. The second direction and the third direction intersect with each other. For example, the second direction and the third direction are perpendicular to each other. The third direction and the first direction intersect with each other. For example, the third direction and the first direction are perpendicular to each other.

[0029] <1. Configuration of image forming device> FIG 1 is a schematic diagram of an image forming apparatus 100. The image forming apparatus 100 is an electrophotographic printer. Specifically, the image forming apparatus 100 is a laser printer or an LED printer. As shown in FIG 1, the image forming apparatus 100 includes a main body frame 101, a drum unit 2, and four developing cartridges 1.

[0030] The four developing cartridges 1 can be attached to the drum unit 2. Furthermore, the drum unit 2 to which the four developing cartridges 1 are attached can be attached to a main body frame 101.

[0031] The four developer cartridges 1 contain toner of different colors. For example, a developer cartridge 1 containing yellow toner, a developer cartridge 1 containing magenta toner, a developer cartridge 1 containing cyan toner, and a developer cartridge 1 containing black toner can be attached to the drum unit 2. The image forming device 100 prints an image on the surface of a printing paper using toner supplied from the developer cartridges 1.

[0032] <2. Structure of the developing cartridge> Fig. 2 is a perspective view of the developing cartridge 1. Fig. 3 is a front view of the developing cartridge 1 when the developing cartridge 1 is viewed in a third direction. Fig. 4 is a cross-sectional view of the developing cartridge 1 taken along line AA in Fig. 3. As shown in Figs. 2 to 4, the developing cartridge 1 includes a housing 10, an agitator 20, a developing roller 30, a supply roller 35, a gear portion 40, and a spacing member 60.

[0033] <2-1. Cabinet> The housing 10 is a container capable of storing toner. The housing 10 has a first end surface 11 and a second end surface 12. The first end surface 11 is located at one end of the housing 10 in the first direction. The second end surface 12 is located at the other end of the housing 10 in the first direction. The first end surface 11 and the second end surface 12 are separated from each other in the first direction.

[0034] A storage chamber 13 is provided inside the housing 10. The toner is stored in the storage chamber 13. The housing 10 also has an opening 14. The opening 14 is located at one end of the housing 10 in the second direction. The external space of the housing 10 and the storage chamber 13 communicate with each other via the opening 14. As shown in FIG. 4, the developing cartridge 1 also has a handle 161 at the other end of the housing 10 in the second direction.

[0035] The housing 10 has a first frame 15 and a second frame 16. The first frame 15 and the second frame 16 are aligned in the third direction. The second frame 16 is cup-shaped. Specifically, the second frame 16 is recessed in a direction away from the first frame 15 in the third direction. The first frame 15 is plate-shaped. The first frame 15 covers the second frame 16.

[0036] The first frame 15 has an outer surface 151. The outer surface 151 is a surface that extends in the first direction and the second direction. In other words, the outer surface 151 is a surface that intersects with the third direction. The first frame 15 and the second frame 16 are fixed to each other. The accommodation chamber 13 is a space surrounded by the first frame 15 and the second frame 16.

[0037] <2-2. Agitator> The agitator 20 is a member that agitates the toner in the housing 10. As shown in FIG. 4, the agitator 20 has an agitator shaft 21 and an agitator blade 22. The agitator shaft 21 extends in a first direction in the housing 10. The agitator shaft 21 is supported by the second frame 16 in a state in which it can rotate about the agitator axis extending in the first direction. The agitator blade 22 spreads outward from the agitator shaft 21 in the radial direction of the agitator shaft 21. The agitator 20 rotates about the agitator axis by a driving force supplied from the image forming apparatus 100. This agitates the toner in the housing 10.

[0038] <2-3. Developing roller> The developing roller 30 is a roller that can rotate about a developing axis that extends in the first direction. The developing roller 30 is located in the opening 14 of the housing 10. That is, the developing roller 30 is located at one end of the housing 10 in the second direction. As shown in FIG. 1, the drum unit 2 has a photosensitive drum 70. When the developing cartridge 1 is attached to the drum unit 2, the developing roller 30 comes into contact with the photosensitive drum 70.

[0039] As shown in FIG. 4, the developing roller 30 has a developing roller body 31 and a developing roller shaft 32. The developing roller body 31 is a cylindrical member extending in a first direction. The developing roller body 31 is made of, for example, elastic rubber. The developing roller shaft 32 is a columnar member extending in the first direction through the developing roller body 31. The developing roller body 31 is fixed to the developing roller shaft 32. The developing roller shaft 32 is made of metal or conductive resin.

[0040] The developing roller 30 is supported by the second frame 16 in a state in which it can rotate about a developing axis extending in the first direction. The developing roller 30 rotates about the developing axis by a driving force supplied from the image forming apparatus 100. The toner in the housing 10 is carried on the outer surface of the developing roller 30.

[0041] As shown in FIG. 4, the developer cartridge 1 has a blade 33. The blade 33 is located in the opening 14. The blade 33 has a blade portion 331 and a holder portion 332 that supports the blade portion 331. The blade portion 331 and the holder portion 332 may be separate parts, or may be molded as a single unit. The blade portion 331 may be welded to the holder portion 332, or may be attached by, for example, a screw. The blade portion 331 is an elastic plate.

[0042] One end of the blade 33 is fixed to the housing 10. More specifically, the end of the holder portion 332 in the second direction is fixed to the housing 10. The other end of the blade 33 contacts the outer circumferential surface of the developing roller 30. More specifically, the end of the blade portion 331 in the third direction contacts the outer surface of the developing roller 30. More specifically, the other end of the blade 33 contacts the toner carried on the outer circumferential surface of the developing roller 30. The blade 33 extends in the first direction along the outer circumferential surface of the developing roller 30. The blade 33 shapes the toner carried on the outer circumferential surface of the developing roller 30 to a predetermined thickness.

[0043] As shown in FIGS. 2 to 4, the first frame 15 of the housing 10 has a boss 152. The boss 152 protrudes from an outer surface 151 of the first frame 15 in the third direction. The boss 152 is cylindrical and extends in the third direction. The boss 152 has a screw groove on its inner circumferential surface. Also, as shown in FIGS. 2 to 4, the image forming apparatus 100 has a screw 153. The screw 153 is a component for fixing the blade 33 to the housing 10. The screw 153 is inserted into the boss 152 and fastened to the screw groove. One end of the blade 33 is sandwiched between the outer surface 151 of the first frame 15 and the head of the screw 153 in the third direction. In detail, the end of the holder portion 332 of the blade 33 in the second direction is sandwiched between the outer surface 151 of the first frame 15 and the head of the screw 153 in the third direction. This fixes the blade 33 to the first frame 15.

[0044] <2-4. Supply roller> The supply roller 35 is a roller that is rotatable about a supply axis that extends in the first direction. The supply roller 35 is located inside the housing 10. More specifically, the supply roller 35 is located between the developing roller 30 and the agitator 20 in the second direction.

[0045] As shown in FIG. 4, the supply roller 35 has a supply roller body 36 and a supply roller shaft 37. The supply roller body 36 is a cylindrical member extending in a first direction. The supply roller body 36 is made of, for example, elastic rubber. The outer peripheral surface of the supply roller body 36 contacts the outer peripheral surface of the developing roller body 31. The supply roller shaft 37 is a cylindrical member extending in the first direction through the supply roller body 36. The supply roller body 36 is fixed to the supply roller shaft 37. The supply roller shaft 37 is made of metal or conductive resin.

[0046] The supply roller 35 is supported by the second frame 16 in a state in which it can rotate about a supply shaft extending in the first direction. The supply roller 35 rotates about the supply shaft by a driving force supplied from the image forming apparatus 100. The toner in the housing 10 is supplied to the outer circumferential surface of the developing roller 30 via the outer circumferential surface of the supply roller 35.

[0047] <2-5. Gear section> The gear unit 40 is located on the first end surface 11 of the housing 10. The gear unit 40 has a first cover 41, a coupling 42, and a plurality of gears. The first cover 41 is attached to the first end surface 11 of the housing 10. Specifically, the first cover 41 is fixed to the first end surface 11 of the housing 10 by screws.

[0048] The coupling 42 and the multiple gears are each rotatable about an axis extending in the first direction. At least some of the multiple gears are located between the first end surface 11 of the housing 10 and the first cover 41 in the first direction. That is, at least some of the multiple gears are covered by the first cover 41.

[0049] The coupling 42 is exposed from the first cover 41. When the drum unit 2 in which the developing cartridge 1 is mounted is mounted to the image forming apparatus 100, the drive shaft of the image forming apparatus 100 is connected to the coupling 42. Then, the rotation of the drive shaft is transmitted to the agitator 20, the developing roller 30, and the supply roller 35 via the coupling 42 and multiple gears.

[0050] <2-6. Spacing members> When the drum unit 2 with the four developer cartridges 1 mounted therein is installed in the image forming apparatus 100, the image forming apparatus 100 can perform a separation operation for each developer cartridge 1. The separation operation is an operation for moving the developer roller 30 from a contact position where it contacts the photosensitive drum 70 to a separation position where it is separated from the photosensitive drum 70. The image forming apparatus 100 performs the separation operation for the developer cartridge 1 that is not being used among the four developer cartridges 1. As a result, the developer roller 30 of the developer cartridge 1 that is not being used is separated from the photosensitive drum 70.

[0051] The spacing member 60 is a member for switching the developing roller 30 between the contact position and the separated position described above. In other words, the developing cartridge 1 is switched by the spacing member 60 between a state in which the developing roller 30 is in the contact position and a state in which the developing roller 30 is in the separated position. The spacing member 60 is located between one end and the other end of the housing 10 in the second direction. As shown in FIGS. 2 and 3, the spacing member 60 has a first cam 61, a second cam 62, and a spacing shaft 63.

[0052] The spacing member 60 is made of, for example, resin. Specifically, the first cam 61, the second cam 62, and the spacing shaft 63 are integrally molded from resin. However, the first cam 61, the second cam 62, and the spacing shaft 63 may be separate parts. In that case, only the first cam 61 and the second cam 62 may be made of resin, and the spacing shaft 63 may be made of metal.

[0053] Fig. 5 is a perspective view of the first frame 15. Fig. 6 is a cross-sectional view of the first frame 15 at the position of the line BB in Fig. 3. As shown in Figs. 5 and 6, the first frame 15 of the housing 10 has a first groove 17 and a second groove 18. The first groove 17 and the second groove 18 are located on the outer surface 151 of the first frame 15.

[0054] The first groove 17 is a groove recessed in the third direction in the outer surface 151 of the first frame 15. The first groove 17 extends in the first direction. The first groove 17 has a first edge 171 and a second edge 172. The first edge 171 and the second edge 172 are edges of the first groove 17 in the second direction. The first edge 171 and the second edge 172 are spaced apart in the second direction. The second edge 172 is closer to the developing roller 30 than the first edge 171.

[0055] As shown in FIG. 2, the first cover 41 has a shaft hole 410. The shaft hole 410 penetrates the first cover 41 in the first direction at a position overlapping with the first groove 17 in the first direction. Also, as shown in FIGS. 2 and 3, the developing cartridge 1 has a second cover 51. The second cover 51 is attached to the second end surface 12 of the housing 10. Specifically, the second cover 51 is fixed to the second end surface 12 of the housing 10 by a screw. As shown in FIG. 2, the second cover 51 has a shaft groove 510. The shaft groove 510 penetrates the second cover 51 in the first direction at a position overlapping with the first groove 17 in the first direction.

[0056] The spaced shaft 63 is disposed in the first groove 17. The spaced shaft 63 extends in the first direction along the first groove 17. One end of the spaced shaft 63 in the first direction is inserted into the shaft hole 410. As a result, one end of the spaced shaft 63 in the first direction is supported by the first cover 41. The other end of the spaced shaft 63 in the first direction is inserted into the shaft groove 510. As a result, the other end of the spaced shaft 63 in the first direction is supported by the second cover 51.

[0057] 2, 3, and 5, the housing 10 has a rib 19. The rib 19 is located on the outer surface 151 of the first frame 15. The rib 19 is a protrusion extending in the second direction from the first edge 171 of the first groove 17 toward the separation shaft 63. That is, the rib 19 is a protrusion extending in the second direction from the first edge 171 of the first groove 17 toward the second edge 172. The rib 19 is located near the center of the first groove 17 in the first direction.

[0058] The rib 19 covers a portion of the spaced shaft 63 disposed in the first groove 17. This prevents the spaced shaft 63 from bending in the third direction toward the outside of the housing 10. In particular, when the spaced shaft 63 is made of resin, the rigidity is smaller than when the spaced shaft 63 is made of metal, and the spaced shaft 63 is more likely to bend. However, the rib 19 covers the vicinity of the center of the spaced shaft 63 in the first direction, thereby preventing the vicinity of the center of the spaced shaft 63 in the first direction from bending in the third direction toward the outside of the housing 10.

[0059] As shown in FIG. 2 and FIG. 3, the spaced shaft 63 has a thin-walled portion 631. The thin-walled portion 631 is located on a side portion of the spaced shaft 63 in the second direction. The thin-walled portion 631 faces the first edge 171 in the second direction. The thin-walled portion 631 is located near the center of the spaced shaft 63 in the first direction. The thickness of the thin-walled portion 631 in the third direction is thinner than the thickness of the portion of the spaced shaft 63 other than the thin-walled portion 631 in the third direction. The rib 19 covers the thin-walled portion 631. This can prevent the rib 19 from protruding from the outer surface 151 of the first frame 15 in the third direction.

[0060] Furthermore, the spacer shaft 63 has a recess 632. The recess 632 penetrates a portion of the thin-walled portion 631 in the third direction. The recess 632 is recessed in the thin-walled portion 631 in a direction from the first edge 171 to the second edge 172. The length of the recess 632 in the first direction is longer than the length of the rib 19 in the first direction.

[0061] When the spaced shaft 63 is attached to the housing 10, first, the spaced shaft 63 is placed in the first groove 17 with the rib 19 and the recess 632 overlapping in the third direction. That is, the spaced shaft 63 is placed in the first groove 17 with the rib 19 and the recess 632 at the same position in the first direction. At this time, the rib 19 passes through the recess 632 in the third direction. Thereafter, the spaced shaft 63 is moved in the first direction relative to the housing 10. Then, the rib 19 and the recess 632 are placed at different positions in the first direction. This results in a state in which the rib 19 covers the thin portion 631. As a result, it is possible to prevent the spaced shaft 63 from coming off the first groove 17.

[0062] The second groove 18 is a groove recessed in the third direction in the outer surface 151 of the first frame 15. The second groove 18 extends in the second direction from the second edge 172 of the first groove 17 toward the developing roller 30. In other words, the second groove 18 extends from the second edge 172 of the first groove 17 in a direction away from the rib 19 in the second direction.

[0063] The second groove 18 is a groove for removing the slide core 93 for molding the rib 19 when the first frame 15 is manufactured by injection molding. Therefore, the second groove 18 includes a portion located at the same position as the rib 19 in the first direction. The width of the second groove 18 in the first direction is larger than the width of the rib 19 in the first direction.

[0064] The first cam 61 is located at one end of the spacing member 60 in the first direction. The first cam 61 is located at the first end surface 11 of the housing 10. The first cam 61 has a first inclined surface 611. The first inclined surface 611 is a part of a circumferential surface centered on the spacing shaft 63. The first inclined surface 611 is inclined with respect to the first direction. More specifically, the first inclined surface 611 is inclined so as to move away from the developing roller 30 in the second direction as it approaches the other end of the spacing member 60 in the first direction.

[0065] The second cam 62 is located at the other end of the spacing member 60 in the first direction. The second cam 62 is located at the second end surface 12 of the housing 10. The second cam 62 has a second inclined surface 621. The second inclined surface 621 is a part of a circumferential surface centered on the spacing shaft 63. The second inclined surface 621 is inclined with respect to the first direction. More specifically, the second inclined surface 621 is inclined so as to move away from the developing roller 30 in the second direction as it approaches the other end of the spacing member 60 in the first direction.

[0066] 2, the spacing member 60 has a positioning protrusion 64. The positioning protrusion 64 is located at one end of the spacing member 60 in the first direction. The positioning protrusion 64 protrudes from the first cam 61 toward the outside in the radial direction of the spacing shaft 63. When the developer cartridge 1 is attached to the drum unit 2, the positioning protrusion 64 comes into contact with the frame of the drum unit 2 in the first direction. This positions the spacing member 60 relative to the drum unit 2 in the first direction.

[0067] The spacing member 60 is movable in the first direction between a first position and a second position relative to the housing 10 and the developing roller 30. The first position is the position of the spacing member 60 in the first direction in a state in which the positioning protrusion 64 is in contact with the frame of the drum unit 2. Movement from the first position to the second position is movement in a direction from the first cam 61 toward the second cam 62. In other words, the position where the spacing member 60 moves toward the other end side from the first position in the first direction is the second position.

[0068] The developing cartridge 1 also has a return spring 66 (see FIGS. 7 and 8). The return spring 66 is an elastic member that is expandable and contractible in a first direction. For example, a compression coil spring is used for the return spring 66. The return spring 66 is located at the first end surface 11 of the housing 10. The return spring 66 is covered by the first cover 41. The return spring 66 is located between the first end surface 11 of the housing 10 and the first cam 61 in the first direction.

[0069] The return spring 66 is compressed in the first direction beyond its natural length. Therefore, the return spring 66 urges the spacing member 60 in the first direction from the second position toward the first position. In other words, the return spring 66 urges the spacing member 60 in the direction from the second cam 62 toward the first cam 61. Therefore, the spacing member 60 is located at the first position when not pressed by the pressing shaft 102 described below.

[0070] <3. About the separation operation> Next, the spacing operation of the image forming apparatus 100 will be described. Figures 7 and 8 are cross-sectional views including the spacing member 60 of the drum unit 2 to which the developer cartridge 1 is attached. Figure 7 shows a state in which the spacing operation is not being performed. Figure 8 shows a state in which the spacing operation is being performed.

[0071] 7 and 8, the image forming apparatus 100 has a pressing shaft 102. When the drum unit 2, to which the four developing cartridges 1 are attached, is attached to the main body frame 101, the pressing shaft 102 faces the first cams 61 of the developing cartridges 1 in the first direction.

[0072] The pressing shaft 102 is movable in the first direction between a retracted position and a protruding position closer to the developing cartridge 1 than the retracted position. FIG. 7 shows a state in which the pressing shaft 102 is located at the retracted position, and FIG. 8 shows a state in which the pressing shaft 102 is located at the protruding position. When the image forming apparatus 100 performs a separating operation, the pressing shaft 102 is moved from the retracted position to the protruding position. This causes the pressing shaft 102 to come into contact with the first cam 61. The pressing shaft 102 then presses the spacing member 60 in the first direction, in a direction from the first cam 61 to the second cam 62. Then, the return spring 66 is compressed, and the spacing member 60 moves in the first direction from the first position to the second position relative to the housing 10.

[0073] When the spacing member 60 moves from the first position to the second position, the first inclined surface 611 of the first cam 61 moves in the first direction while contacting the frame of the drum unit 2. At this time, the first cam 61 moves in the second direction relative to the drum unit 2 due to the resistance force received from the frame of the drum unit 2. More specifically, the first cam 61 moves in a direction away from the photosensitive drum 70 relative to the drum unit 2 due to the resistance force received from the frame of the drum unit 2.

[0074] Similarly, when the spacing member 60 moves from the first position to the second position, the second inclined surface 621 of the second cam 62 moves in the first direction while contacting the frame of the drum unit 2. At this time, the second cam 62 moves in the second direction relative to the drum unit 2 due to the resistance force received from the frame of the drum unit 2. More specifically, the second cam 62 moves in a direction away from the photosensitive drum 70 relative to the drum unit 2 due to the resistance force received from the frame of the drum unit 2.

[0075] As a result, the housing 10 and the developing roller 30 move together with the spacing member 60 in the second direction relative to the drum unit 2. More specifically, the housing 10 and the developing roller 30 move in a direction away from the photosensitive drum 70 relative to the drum unit 2. As a result, the developing roller 30 moves in the second direction from a contact position where it contacts the photosensitive drum 70 to a separated position where it is separated from the photosensitive drum 70.

[0076] <4. Manufacturing method of the first frame> Next, a manufacturing method of the first frame 15 used in the housing 10 of the developing cartridge 1 will be described. Fig. 9 is a flow chart showing the manufacturing procedure of the first frame 15. Figs. 10 to 12 are diagrams showing the state of the first frame 15 during manufacturing. Figs. 10 to 12 show cross sections perpendicular to the first direction.

[0077] The first frame 15 is manufactured by injection molding of resin. When manufacturing the first frame 15, the manufacturer first prepares a mold 90. The mold 90 has a first core 91, a second core 92, and a slide core 93. The first core 91 is a core for molding the inner surface of the first frame 15. The second core 92 is a core for molding the outer surface of the first frame 15. The second core 92 is movable in a third direction relative to the first core 91. The slide core 93 is a core (nested) for molding at least a portion of the rib 19. The slide core 93 is movable in a second direction relative to the first core 91 and the second core 92.

[0078] 10, a cavity 94 corresponding to the shape of the first frame 15 is formed inside the mold 90. Each of the first core 91, the second core 92, and the slide core 93 may be composed of a plurality of cores.

[0079] The manufacturer pours molten resin into cavity 94 in mold 90 (step S1). Mold 90 is provided with a gate (hole) not shown. The molten resin is supplied to cavity 94 through the gate. As shown in FIG. 11, when the resin has filled cavity 94 in mold 90, the manufacturer hardens the resin in mold 90 (step S2). For example, when a thermosetting resin is used, the resin in mold 90 is heated to harden the resin. In this way, first frame 15 is formed.

[0080] Thereafter, the manufacturer opens the mold 90 and releases the first frame 15 from the mold 90 (step S3). Specifically, as shown in FIG. 12, the second core 92 is opened in the third direction relative to the first core 91, and the slide core 93 is opened in the second direction relative to the first core 91 and the second core 92. At this time, at least a portion of the slide core 93 moves in the second direction through the second groove 18. As a result, the first frame 15 is removed from the mold 90.

[0081] Since the rib 19 protrudes in the second direction, the rib 19 and a part of the first groove 17 face each other in the third direction. For this reason, the surface of the rib 19 facing the first groove 17 and the surface of the first groove 17 facing the rib 19 cannot be molded by only the first core 91 and the second core 92 that open in the third direction. However, by using the slide core 93 that opens in the second direction as described above, it becomes possible to mold the surface of the rib 19 facing the first groove 17 and the surface of the first groove 17 facing the rib 19.

[0082] Furthermore, by providing the second groove 18 in the first frame 15 as described above, it becomes possible to pull out the slide core 93 in the second direction relative to the first core 91 and the second core 92. This makes it possible to easily manufacture the first frame 15 having the rib 19.

[0083] The second groove 18 is located at a different position in the first direction from the boss 152 described above. Therefore, when the slide core 93 is pulled out in the second direction, there is no interference between the slide core 93 and the boss 152. In this way, both the boss 152 and the second groove 18 can be provided in the first frame 15. Therefore, it is possible to both fix the blade 33 to the first frame 15 and form the rib 19 by pulling out the slide core 93 in the second direction.

[0084] In the first groove 17, a burr may occur at a parting line portion corresponding to the boundary between the second core 92 and the slide core 93. The burr is a thin-walled protrusion. When the burr contacts the separated shaft 63, the separated shaft 63 may be difficult to move in the first direction. Therefore, as shown in FIG. 5, the first groove 17 has two first convex portions 173 and a second convex portion 174. The first convex portion 173 and the second convex portion 174 protrude from the surface of the first groove 17 in the third direction. In this way, the separated shaft 63 contacts the first convex portion 173 and the second convex portion 174. Therefore, even if a burr occurs at the parting line portion of the first groove 17 during molding of the first frame 15, the separated shaft 63 can be prevented from contacting the burr.

[0085] The first convex portion 173 and the second convex portion 174 are located at positions spaced apart in the first direction. Specifically, the first convex portion 173 is located on one side of the second groove 18 in the first direction. The second convex portion 174 is located on the other side of the second groove 18 in the first direction. That is, the second groove 18 is located between the first convex portion 173 and the second convex portion 174 in the first direction. In this way, the separated shaft 63 can be supported by two convex portions spaced apart in the first direction. Therefore, the posture of the separated shaft 63 can be stabilized.

[0086] <5. Modifications> Although one embodiment has been described above, the present disclosure is not limited to the above embodiment.

[0087] In the above embodiment, a portion of the rib 19 is molded by the slide core 93, and the other portion of the rib 19 is molded by the second core 92. However, the slide core 93 may mold the entire rib 19.

[0088] In the above embodiment, the rib 19 extends from the first edge 171 of the first groove 17 toward the second edge 172, and the second groove 18 extends from the second edge 172 of the first groove 17 toward one end of the housing 10 in the second direction. However, the rib 19 may extend from the second edge 172 of the first groove 17 toward the first edge 171, and the second groove 18 may extend from the first edge 171 of the first groove 17 toward the other end of the housing 10 in the second direction.

[0089] In the above embodiment, the number of developer cartridges 1 that can be attached to the drum unit 2 is four. However, the number of developer cartridges 1 that can be attached to the drum unit 2 may be one to three, or may be five or more.

[0090] In addition, the detailed shape and structure of the developing cartridge may be appropriately changed without departing from the spirit of the present invention. Furthermore, the elements appearing in the above embodiment and modified examples may be appropriately selected without departing from the spirit of the present invention. [Explanation of symbols]

[0091] 1 Developer cartridge 2 Drum Unit 10. Chassis 15 1st Frame 17 First groove 18 Second groove 19 Ribs 30 Developing roller 60 Spacer 61 First Cam 62 2nd Cam 63 Spaced shaft 70 Photoconductor drum 90 Mold 91 1st Core 92 2nd Core 93 Slide Core 100 Image forming device 152 Boss 171 First Edge 172 Second Edge 173 First protrusion 174 Second convex part 632 Recess

Claims

1. A housing capable of accommodating toner; a developing roller rotatable about a developing axis extending in a first direction, the developing roller being located at one end of the housing in a second direction intersecting the first direction; a spacer shaft movable in the first direction relative to the housing; Equipped with the housing has an outer surface that extends in the first direction and the second direction; The outer surface is a first groove extending in the first direction and in which the spaced shaft is disposed, the first groove having a first edge in the second direction and a second edge spaced from the first edge in the second direction; a rib extending in the second direction from the first edge toward the spaced shaft and covering a portion of the spaced shaft; a second groove including a portion located at the same position as the rib in the first direction, the second groove extending from the second edge in a direction away from the rib in the second direction; A developing cartridge comprising:

2. 2. The developing cartridge according to claim 1, A developing cartridge characterized in that the second groove is passed by a slide core serving as a mold for molding the rib when the slide core is opened in the second direction during manufacture of the housing.

3. 3. The developing cartridge according to claim 1, a width of the second groove in the first direction is greater than a width of the rib in the first direction.

4. 3. The developing cartridge according to claim 1, the second edge is closer to the developing roller than the first edge; The rib extends in the second direction from the first edge to the second edge, the second groove extends in the second direction from the second edge toward the developing roller,

5. 3. The developing cartridge according to claim 1, the first groove has a protrusion protruding in a third direction intersecting the first direction and the second direction.

6. 6. The developing cartridge according to claim 5, The first groove is A first protrusion, which is the protrusion; a second convex portion which is the convex portion and is located away from the first convex portion in the first direction; A developing cartridge comprising:

7. 7. The developing cartridge according to claim 6, a developing cartridge, wherein the second groove is located between the first convex portion and the second convex portion in the first direction.

8. 3. The developing cartridge according to claim 1, The housing includes: a boss protruding from the outer surface in a third direction intersecting the first direction and the second direction; having The developing cartridge, wherein the second groove is located at a position different from the boss in the first direction.

9. 9. The developing cartridge according to claim 8, a boss having a cylindrical shape extending in the third direction and having a screw groove on an inner surface thereof,

10. 10. The developing cartridge according to claim 9, a blade that contacts the outer peripheral surface of the developing roller; A screw for fixing the blade to the housing; Further equipped with A developing cartridge, wherein the screw is inserted into the screw groove.

11. 3. The developing cartridge according to claim 1, The spaced shaft includes: a recess extending through the spaced shaft in a third direction intersecting the first and second directions, the recess having a length in the first direction greater than that of the rib; A developing cartridge comprising:

12. 3. The developing cartridge according to claim 1, The developing cartridge, wherein the spacer shaft is made of resin.

13. A method for manufacturing a frame including the outer surface used for the housing of the developing cartridge according to claim 1, comprising the steps of: a) pouring molten resin into a cavity in a mold formed by a first core, a second core movable relative to the first core in a third direction intersecting the first direction and the second direction, and a slide core movable in the second direction relative to the first core and the second core; b) forming the frame by curing the resin in the mold; c) removing the frame from the mold by opening the second core relative to the first core in the third direction and opening the slide core relative to the first core and the second core through the second groove in the second direction; having The manufacturing method according to claim 1, wherein at least a portion of the rib is molded by the slide core.

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