JP6494290B2 - Process cartridge - Google Patents

Description

  The present invention relates to a process cartridge used in an electrophotographic image forming apparatus.

  There are electrophotographic image forming apparatuses that form an image on a recording medium using an electrophotographic image forming system, such as an electrophotographic copying machine, an electrophotographic printer (LED printer, laser beam printer, etc.), a facsimile machine, and a word processor. In the electrophotographic image forming apparatus, an electrophotographic photosensitive drum (hereinafter referred to as a photosensitive drum) and process means acting on the electrophotographic photosensitive drum are integrally formed into a cartridge, which is removed from the main body of the electrophotographic image forming apparatus. A process cartridge that can be mounted is used. As the process cartridge, for example, there is a cartridge in which at least one of an electrophotographic photosensitive drum, a developing unit as a process unit, a charging unit, and a cleaning unit is integrated into a cartridge. As a configuration of the process cartridge, there is one in which a photosensitive drum, a drum unit having a cleaning unit, and a developing unit having a developing unit are connected to each other so as to be rotatable (see, for example, Patent Document 1). In this process cartridge, a pin is used as a coupling member for rotatably connecting the drum unit and the developing unit. The pin is fixed by being press-fitted into the mounting hole of the drum unit.

JP 2002-268519 A

  However, the above conventional example has the following problems. Since the pin as the coupling member is press-fitted and fixed in the mounting hole of the drum unit, the press-fitting margin varies due to variations in the outer diameter of the pin and the inner diameter of the mounting hole. If the press-fitting allowance is small, the pin may come off due to vibration or impact, for example. If the press-fitting allowance is large, there is a possibility that a large load is applied to the mounting hole or the ease of assembly is reduced. Although it is conceivable to form (process) the pin outer diameter and the mounting hole inner diameter with high precision in order to reduce the variation, there is a problem that the processing cost and management cost of parts and molds increase.

  The present invention has been made in view of the above problems, and provides a process cartridge including two units that are pivotably connected to each other by a shaft member that can be press-fitted with an appropriate force and can be securely fixed. With the goal.

The present invention
A first unit provided with a first hole ;
A second unit provided with a second hole ;
A shaft member inserted into the first hole and the second hole, and connecting the first unit and the second unit ;
Have
By fitting engagement previous Kijiku member into the first hole, the first unit, to the second unit, rotatably coupled around the shaft member,
The second hole is formed with a resistance portion that comes into contact with the outer peripheral surface of the shaft member during insertion of the shaft member and becomes resistance to insertion,
The second unit includes a third hole for restricting a position of the shaft member in a direction perpendicular to the insertion direction when the shaft member is inserted,
The shaft member has a positioning portion restricted by the third hole,
The third hole and the positioning portion are arranged so that the resistance portion and the shaft member are in contact with each other in a state where the positioning portion is fitted in the third hole when the shaft member is inserted.
The second unit is configured such that when the shaft member is inserted into the second hole against the resistance, a portion on the outer peripheral surface side of the shaft member and the resistance portion are melted to cause the second hole and the shaft to melt. by and the members are welded, the shaft member is a process cartridge characterized in that it is fixed relative to the second unit.

  According to the present invention, it is possible to provide a process cartridge including two units that are rotatably connected to each other by a shaft member that can be press-fitted with an appropriate force and can be reliably fixed.

Sectional drawing which shows the assembly | attachment part of the connecting shaft of Example 1. FIG. Cross section of electrophotographic image forming apparatus Perspective view of image forming apparatus main body and process cartridge with open / close door open Cross section of process cartridge The perspective view explaining the structure of a process cartridge Sectional drawing explaining the assembly method of the connection shaft of Example 1. FIG. Sectional drawing explaining the assembly method of the connection shaft of the modification of Example 1. FIG. Sectional drawing explaining the assembly method of the connection shaft of Example 2. FIG. Sectional drawing explaining the assembly method of the connection shaft of the modification of Example 2. FIG. Sectional drawing explaining the assembly method of the connection shaft of Example 3. Sectional drawing explaining the assembly method of the connection shaft of the modification of Example 3. FIG. Sectional drawing explaining the assembly method of the connection shaft of the modification of Example 3. FIG. Sectional drawing explaining the assembly method of the connection shaft of the modification of Example 3. FIG.

  Embodiments of the process cartridge of the present invention will be described below with reference to the drawings. However, since the dimensions, materials, shapes, relative positions, etc. of the components described in this embodiment are appropriately changed depending on the configuration of the apparatus to which the present invention is applied and various conditions, specific descriptions are provided. Unless otherwise specified, the scope of the present invention is not limited thereto.

Example 1
(Configuration of the entire image forming apparatus)
FIG. 2 is a cross-sectional view illustrating a configuration of the image forming apparatus 100 in a state where the process cartridge B is mounted on the apparatus main body A. The image forming apparatus 100 forms a latent image by irradiating information light 1 (laser light, LED light, etc.) based on image information from the exposure unit 3 onto the photosensitive drum 62 which is an electrophotographic photosensitive member. A toner image is formed by attaching toner as a developer to the image. At this time, the recording medium 2 is conveyed from the recording medium supply unit 4 in synchronization with the formation of the toner image, and the toner image formed on the photosensitive drum 62 is transferred to the recording medium 2 by the transfer unit 7. The transferred image is fixed on the recording medium 2 by the fixing unit 9 and then discharged to the recording medium discharge unit 11. An arrow D indicates the conveyance path of the recording medium 2.

(Removal of process cartridge)
Next, attachment / detachment of the process cartridge B to / from the apparatus main body A will be described with reference to FIG.
FIG. 3 is a perspective view of the apparatus main body A and the process cartridge B with the open / close door 13 opened to detach the process cartridge B.
An opening / closing door 13 is rotatably attached to the apparatus main body A. The process cartridge B is mounted in or removed from the apparatus main body A along the guide rail 12 with the open / close door 13 opened. When the door 13 is closed, the drive shaft 14 driven by a motor (not shown) of the apparatus main body A is driven by a driving force receiving portion 63 a (
(See FIG. 5), and the driving force can be transmitted to the photosensitive drum 62.

(Process cartridge configuration)
Next, the configuration of the process cartridge B will be described with reference to FIGS. FIG. 4 is a cross-sectional view of the process cartridge B, and FIG. 5 is a perspective view illustrating the configuration of the process cartridge B.
The process cartridge B is configured by combining a drum unit 60 (second unit) and a developing unit 20 (first unit).
The drum unit 60 includes a drum frame 71, a photosensitive drum 62, a charging roller 66, a cleaning blade 77, and the like.

On the other hand, the developing unit 20 includes a toner storage container 21, a lid 22, a developing container 23, a first side member 26L, a second side member 26R, a developing blade 42, a developing roller 32, a magnet roller 34, a conveying member 43, a toner T, It consists of an urging member 46 and the like.
The drum unit 60 and the developing unit 20 are connected to each other by a connecting shaft 75 as a connecting member so as to be rotatable. Thus, an integral process cartridge B is configured.

  Specifically, connecting holes 23bL and 23bR parallel to the axial direction of the developing roller 32 are provided at the ends of the arm portions 23aL and 23aR formed at both ends in the longitudinal direction of the developing container 23 (rotational axis direction of the photosensitive drum 62). It has been. In addition, insertion holes 71aL and 71aR for inserting the connecting shaft 75 are formed at both ends in the longitudinal direction of the drum frame 71.

  Then, the arm portions 23aL, 23aR are aligned with predetermined positions of the drum frame 71, and the connecting shaft 75 is inserted into the fitting hole 71aL, the connecting hole 23bL, the fitting hole 71aR, and the connecting hole 23bR, respectively. Here, the connecting shaft 75 is fixed to the fitting holes 71aL and 71aR, and is fitted to the connecting holes 23aL and 23aR so as to be rotatable. Thereby, the drum unit 60 and the developing unit 20 are coupled so as to be relatively rotatable about the connecting shaft 75.

Further, an urging member 46 attached to the base of the arm portions 23aL and 23aR abuts on the drum frame 71, and urges the developing unit 20 toward the drum unit 60 with the connecting shaft 75 as a rotation center.
Then, an interval holding member (not shown) attached to both ends of the developing roller 32 is brought into contact with the photosensitive drum 62 by the urging force, and the developing roller 32 is held from the photosensitive drum 62 at a predetermined interval.

(Structure of connecting part of drum unit and developing unit)
Next, a configuration for fixing the connecting shaft 75 to the drum frame 71 will be described.
The connecting shaft 75 is provided at both ends in the longitudinal direction of the process cartridge B, but since the structure is the same, only one side will be described.

FIG. 1 is a cross-sectional view of the connecting shaft 75, the insertion hole 71aR of the drum frame 71, and the arm portion 23aR of the developing container 23. The connecting shaft 75 and the drum frame 71 of the first embodiment are formed of compatible thermoplastic resins (polystyrene, ABS resin, etc.). As shown in the figure, the connecting shaft 75 that is a shaft member has a connecting portion 75a that is rotatably fitted to a connecting hole 23bR (first hole) provided in the arm portion 23aR. Further, the connecting shaft 75 has a welded portion 75b that fits into a second hole 71aR2 provided in the drum frame 71 and is fixed to the drum unit 60 by welding. Further, the connecting shaft 75 has a positioning portion 75c that is fitted in a third hole 71aR1 provided in the drum frame 71 and is used for positioning in a plane perpendicular to the insertion direction when the connecting shaft 75 is inserted. The connecting portion 75a and the positioning portion 75c are cylindrical, and the diameter of the positioning portion 75c is the connecting portion 75a.
Greater than the diameter of The welded portion 75b is a portion that is inserted into the second hole 71aR2 between the positioning portion 75c and the connecting portion 75a. On the outer peripheral surface side, the connecting shaft 75 is inserted when the drum unit 60 and the developing unit 20 are connected. A tapered surface that is reduced in diameter in the direction is formed. Moreover, the connection part 75a, the welding part 75b, and the positioning part 75c are arrange | positioned coaxially. In addition, the connection shaft 75 of Example 1 is formed by injection molding, and has a shape provided with a lightening.

  On the other hand, the insertion hole 71aR of the drum frame 71 has a shape in which a third hole 71aR1 that fits with the positioning portion 75c of the connecting shaft 75 and a second hole 71aR2 that is welded to the welding portion 75b of the connecting shaft 75 are arranged on the same axis. It has become. In a state where the drum unit 60 and the developing unit 20 are connected by the connecting shaft 75, the third hole 71aR1, the second hole 71aR2, and the connecting hole 23bR (first hole) are coaxial with the connecting shaft 75.

  Here, the portion of the drum frame 71 provided with the third hole 71aR1 and the portion of the drum frame 71 provided with the second hole 71aR2 are integrally configured. An example configured separately will be described later. On the inner peripheral surface of the second hole 71aR2, a tapered surface is formed that is reduced in diameter in the insertion direction of the connecting shaft 75 when the drum unit 60 and the developing unit 20 are connected. The taper small diameter ΦD71 is the same diameter as the taper small diameter ΦD75 of the weld portion 75b. The taper angle L of the welded portion 75b and the taper angle K of the second hole 71aR2 are set to different angles. Here, the taper angle L of the welded portion 75b is larger than the taper angle K of the second hole 71aR2. An example in which the taper angle L of the welded portion 75b is smaller than the taper angle K of the second hole 71aR2 will be described later.

(Fixing the connecting shaft)
Next, a method for fixing the connecting shaft 75 will be described.
First, as shown in FIG. 1, the drum unit 60 and the developing unit 20 are held so that the fitting hole 71aR and the connection hole 23bR are aligned so as to be approximately coaxial. Then, the connecting shaft 75 is inserted in the direction of the arrow X into the fitting hole 71aR.

  FIG. 6A shows a state in which the connecting shaft 75 is partially inserted partway into the insertion hole 71aR. In the example of FIG. 6, the third hole 71aR1, the second hole 71aR2, and the connection hole 23bR (first hole) are the third hole 71aR1, the second hole 71aR2, and the connection hole 23bR from the upstream side in the insertion direction X of the connection shaft 75. It is located in the order of (first hole). That is, from the upstream side in the insertion direction X, the portion of the drum frame 71 provided with the third hole 71aR1, the portion of the drum frame 71 provided with the second hole 71aR2, and the arm portion 23aR are positioned in this order.

  At this time, since the positioning portion 75c and the third hole 71aR1 are fitted, the connecting shaft 75 is positioned in the radial direction (in a plane perpendicular to the axial direction) with respect to the fitting hole 71aR. Further, the connecting portion 75a and the connecting hole 23bR are fitted, and the arm portion 23aR is rotatably supported by the connecting shaft 75. The welded portion 75b and the second hole 71aR2 are in a state in which the tapered surface of the welded portion 75b and the tapered entrance of the second hole 71aR2 abut each other at a point P. The portion of the second hole 71aR2 that contacts the tapered surface of the welded portion 75b at the taper entrance is a resistance portion that comes into contact with the outer peripheral surface of the connecting shaft 75 during insertion of the connecting shaft 75 and becomes resistant to insertion.

Then, from this state, the ultrasonic horn H is brought into contact with the end surface 75d of the connecting shaft 75 and pressed in the arrow X direction while applying ultrasonic vibration. As a result, frictional heat is generated by a slight vibration applied from the outside to the contact portion between the welded portion 75b and the resistance portion of the second hole 71aR2, and the resin on the outer peripheral surface side of the connecting shaft 75 and the resistance portion is melted. . Then, the connecting shaft 75 moves in the direction of the arrow X while melting the resin in the contact portion, and is inserted to the position shown in FIG.
Here, the second hole 71aR2 has a large-diameter portion that is adjacent to the tapered portion and has a diameter larger than that of the connecting shaft 75. In the example of FIG. 6, the large diameter portion has the same diameter as the third hole 71aR1. A part of the material (resin) melted when the connecting shaft 75 is inserted is pushed out into the space S between the fitting hole 71aR and the connecting shaft 75 as the connecting shaft 75 is inserted. In this way, by adopting a configuration in which there is a clearance space (gap) through which molten resin can flow, it is possible to suppress deformation due to excessive force applied to the components during welding.
In the welding region W indicated by the broken line, the welded portion 75b and the second hole 71aR2 are welded, and the connecting shaft 75 is fixed to the fitting hole 71aR. In FIG. 6B, the welded portion 75b and the second hole 71aR2 are drawn to overlap for the sake of explanation, but actually the resin is melted and integrated. The same applies to the description of other configurations. As described above, by performing the welding process in a state where the connecting shaft 75 is positioned in the radial direction, the connecting shaft 75 is accurately coupled to the insertion hole 71aR without being displaced when the resin is melted. be able to. In the state of FIG. 6B, the connecting shaft 75 is positioned in the axial direction with respect to the fitting hole 71aR by the flange portion 75e coming into contact with the entrance of the fitting hole 71aR.

  As described above, if the connecting shaft 75 is welded and fixed to the fitting hole 71aR of the drum frame 71, the shaft member can be press-fitted with an appropriate force, so that the assembly is easy and the connecting shaft 75 is securely fixed. Thus, a process cartridge in which the removal of the toner is suppressed can be obtained.

(Modification of Example 1)
Next, a modification of the first embodiment will be described with reference to FIG. The configuration of FIG. 7 differs from the above-described configuration in the arrangement of the connecting portion of the connecting shaft 75 and the fitting hole 71aR and the connecting portion.

  The connecting shaft 75 of this configuration is provided with a welding portion 75b, a positioning portion 75c, and a connecting portion 75a in order from the upstream side in the insertion direction (the direction of the arrow X). Correspondingly, a second hole 71aR2 as a welding portion is provided on the entrance side of the fitting hole 71aR, and a third hole 71aR1 as a fitting portion is provided on the back side. The welded portion 75b and the second hole 71aR2 each have a tapered shape, and the taper angle of the welded portion 75b is smaller than the taper angle of the second hole 71aR2. In the example of FIG. 7, the third hole 71aR1, the second hole 71aR2, and the connection hole 23bR (first hole) are the second hole 71aR2, the third hole 71aR1, and the connection hole 23bR from the upstream side in the insertion direction X of the connection shaft 75. It is located in the order of (first hole). That is, from the upstream side in the insertion direction X, the portion of the drum frame 71 provided with the second hole 71aR2, the portion of the drum frame 71 provided with the third hole 71aR1, and the arm portion 23aR are positioned in this order.

  FIG. 7A shows a state where the taper surface of the welded portion 75b and the back side of the taper of the second hole 71aR2 abut each other at a point P. FIG. From here, as in the above configuration, the ultrasonic wave is applied to the connecting shaft 75 by the ultrasonic horn H while pressing in the direction of the arrow X, and inserted to the position shown in FIG. Thereby, the welding region W is welded to the connecting shaft 75 and the fitting hole 71aR. Further, the configuration in which the flange portion 75e abuts on the entrance of the insertion hole 71aR and the configuration in which the space S is provided as the escape space for the molten resin are the same as the configuration described above.

As described above, in the axial direction of the connecting shaft 75, the fitting portion between the connecting shaft 75 and the arm portion 23aR, the welded portion between the connecting shaft 75 and the fitting hole 71aR, and the positioning portion between the connecting shaft 75 and the fitting hole 71aR are arranged. Even if they are different, the same effect can be obtained.
According to the first embodiment, since the shaft member can be press-fitted with an appropriate force, the assembly is easy, and the process includes two units that are pivotally connected to each other by the shaft member that is difficult to be removed by welding and fixing. A cartridge can be provided.

(Example 2)
Next, a second embodiment of the present invention will be described. In the following description, members having the same functions as those in the first embodiment are denoted by the same reference numerals as those in the first embodiment. Explanation of the same configuration as that of the first embodiment is omitted.
The configuration of the second embodiment will be described with reference to FIGS. The feature of the second embodiment is that the connecting hole 23bR is provided between the third hole 71aR1 and the second hole 71aR2 in the axial direction of the connecting shaft 75.

  In the configuration of FIG. 8, a welding portion is provided on the upstream side in the insertion direction of the connecting shaft 75 (the direction of the arrow X), and a positioning portion is provided on the downstream side. That is, the third hole 71aR1, the second hole 71aR2, and the connection hole 23bR (first hole) are arranged in the second hole 71aR2, the connection hole 23bR (first hole), and the third hole 71aR1 from the upstream side in the insertion direction X of the connection shaft 75. It is located in the order. That is, from the upstream side in the insertion direction X, the part of the drum frame 71 provided with the second hole 71aR2, the arm part 23aR, and the part of the drum frame 71 provided with the third hole 71aR1 are positioned in this order. The portion of the drum frame 71 provided with the third hole 71aR1 and the portion of the drum frame 71 provided with the second hole 71aR2 are configured separately.

  In the configuration of FIG. 9, a positioning portion is provided on the upstream side in the insertion direction of the connecting shaft 75, and a welding portion is provided on the downstream side. That is, the third hole 71aR1, the second hole 71aR2, and the connection hole 23bR (first hole) are arranged in the third hole 71aR1, the connection hole 23bR (first hole), and the second hole 71aR2 from the upstream side in the insertion direction X of the connection shaft 75. It is located in the order. That is, from the upstream side in the insertion direction X, the part of the drum frame 71 in which the third hole 71aR1 is provided, the arm part 23aR, and the part of the drum frame 71 in which the second hole 71aR2 is provided are positioned in this order. The portion of the drum frame 71 provided with the third hole 71aR1 and the portion of the drum frame 71 provided with the second hole 71aR2 are configured separately.

  Since the connecting shaft 75 is held at both ends (having a bearing structure) in this way, the tilting of the connecting shaft 75 can be suppressed, so that the support position of the arm portion 23aR is stabilized, and the developing unit 20 is attached to the drum unit 60. The urging force that urges toward becomes stable. Thereby, the urging force can be set small, and the durability of the bearing of the developing roller 32 and the spacing member between the developing roller 32 and the photosensitive drum 62 is improved. Further, since the deflection of the developing roller 32 is suppressed, fluctuations in image density can be suppressed.

  According to the second embodiment, the connecting shaft can be prevented from falling down, so that the support position of the arm portion is stabilized, and the urging force that urges the developing unit toward the drum unit is stabilized. Thereby, the urging force can be set small, and the durability of the bearing member of the developing roller and the interval holding member between the developing roller and the photosensitive drum is improved. Further, since the deflection of the developing roller is suppressed, fluctuations in the image density can be suppressed.

(Example 3)
Next, a third embodiment of the present invention will be described. The configuration of the third embodiment of the present invention will be described with reference to FIGS. 10 to 13 each have a different shape, but all show the configuration of the third embodiment. A feature of the configuration of the third embodiment is that the fourth hole 71bR3 provided in the drum frame 71 and the second positioning portion 75f provided in the connecting shaft 75 are rotatably fitted. Further, in the axial direction of the connecting shaft 75, the connecting hole 23bR is provided between the third hole 71aR1 and the fourth hole 71aR3. In the third embodiment, the third hole 71aR1, the second hole 71aR2, the connection hole 23bR (first hole), and the fourth hole 71bR3 are coaxial with the connection shaft 75.

  In FIG. 10, the third hole 71aR1, the second hole 71aR2, the connection hole 23bR (first hole), and the fourth hole 71bR3 are located in this order from the upstream side in the insertion direction X of the connection shaft 75. The part of the drum frame 71 provided with the third hole 71aR1 and the part of the drum frame 71 provided with the second hole 71aR2 are integrally formed. The part configured integrally and the part of the drum frame 71 provided with the fourth hole 71bR3 are configured separately.

In FIG. 11, from the upstream side in the insertion direction X of the connecting shaft 75, the second hole 71aR2 and the third hole 71a.
R1, the connecting hole 23bR (first hole), and the fourth hole 71bR3 are positioned in this order. The part of the drum frame 71 provided with the third hole 71aR1 and the part of the drum frame 71 provided with the second hole 71aR2 are integrally formed. The part configured integrally and the part of the drum frame 71 provided with the fourth hole 71bR3 are configured separately.

  In FIG. 12, the third hole 71aR1, the connection hole 23bR (first hole), the fourth hole 71bR3, and the second hole 71aR2 are positioned in this order from the upstream side in the insertion direction X of the connection shaft 75. The portion of the drum frame 71 provided with the second hole 71aR2 and the portion of the drum frame 71 provided with the fourth hole 71bR3 are integrally configured. The integrally configured portion and the portion of the drum frame 71 provided with the third hole 71aR1 are configured separately.

  In FIG. 13, the third hole 71aR1, the connection hole 23bR (first hole), the second hole 71aR2, and the fourth hole 71bR3 are positioned in this order from the upstream side in the insertion direction X of the connection shaft 75. The portion of the drum frame 71 provided with the second hole 71aR2 and the portion of the drum frame 71 provided with the fourth hole 71bR3 are integrally configured. The integrally configured portion and the portion of the drum frame 71 provided with the third hole 71aR1 are configured separately.

  By adopting the configuration of the third embodiment, the connecting shaft 75 can be coupled to the drum frame 71 with high accuracy, and in addition, the connecting shaft 75 can be prevented from falling. Therefore, the effects described in the second embodiment can be further improved.

  The present invention can be applied to a configuration in which one of the first unit and the second unit is the drum unit 60 and the other is the developing unit 20. That is, in each of the above embodiments, the drum unit 60 is the second unit and the developing unit 20 is the first unit. However, the developing unit 20 may be the second unit and the drum unit 60 may be the first unit. Moreover, in the said Example, the angle of a taper surface formed in the outer peripheral surface side of a shaft member and the taper angle is made into the shape of the resistance part which contacts the outer peripheral surface of a shaft member at the time of insertion of a shaft member, and becomes resistance with respect to insertion. Different tapered surfaces are illustrated. However, the resistance portion is not limited to this as long as it has a shape that comes into contact with the outer peripheral surface of the shaft member during insertion of the shaft member and becomes resistance to insertion. For example, when a tapered surface that is reduced in diameter in the insertion direction of the shaft member is formed on the outer peripheral surface side of the position where the shaft member is fitted with the second hole, the resistance portion is formed on the inner peripheral surface of the second hole. A stepped protrusion may be used. This step-like protrusion is preferably provided on a tapered surface whose diameter decreases in the insertion direction. As a result, when the shaft member is inserted, the outer peripheral surface of the shaft member and the stepped protrusion come into contact with each other and become resistance when inserted, and frictional heat is generated in the resistance portion due to the application of ultrasonic vibration, and the resistance portion and the shaft member are melted. The second hole and the shaft member are welded and fixed.

20: development unit, 23bL, 23bR: connecting hole, 60: drum unit, 71aL, 71aR: insertion hole, 71aR1: third hole, 71aR2: second hole, 75: connecting shaft, 75a: connecting part, 75b: welded part, 75c: Positioning part

Claims (8)

A first unit provided with a first hole ;
A second unit provided with a second hole ;
A shaft member inserted into the first hole and the second hole, and connecting the first unit and the second unit ;
Have
By fitting engagement previous Kijiku member into the first hole, the first unit, to the second unit, rotatably coupled around the shaft member,
The second hole is formed with a resistance portion that comes into contact with the outer peripheral surface of the shaft member during insertion of the shaft member and becomes resistance to insertion,
The second unit includes a third hole for restricting a position of the shaft member in a direction perpendicular to the insertion direction when the shaft member is inserted,
The shaft member has a positioning portion restricted by the third hole,
The third hole and the positioning portion are arranged so that the resistance portion and the shaft member are in contact with each other in a state where the positioning portion is fitted in the third hole when the shaft member is inserted.
The second unit is configured such that when the shaft member is inserted into the second hole against the resistance, a portion on the outer peripheral surface side of the shaft member and the resistance portion are melted to cause the second hole and the shaft to melt. by and the members are welded, the shaft member is a process cartridge characterized in that it is fixed relative to the second unit.   2. The process cartridge according to claim 1, wherein the portion on the outer peripheral surface side of the shaft member and the resistance portion are melted by frictional heat generated by microvibration applied from the outside when the shaft member is inserted into the second hole. . A tapered surface that is reduced in diameter in the insertion direction of the shaft member is formed on a portion on the outer peripheral surface side of the position where the shaft member is fitted with the second hole.
The said resistance part is a taper surface in which the taper angle differs from the taper surface of the said shaft member formed in the internal peripheral surface of the said 2nd hole and diameter-reducing in the said insertion direction. Process cartridge. A tapered surface that is reduced in diameter in the insertion direction of the shaft member is formed on a portion on the outer peripheral surface side of the position where the shaft member is fitted with the second hole.
The process cartridge according to claim 1, wherein the resistance portion is a stepped protrusion formed on an inner peripheral surface of the second hole.   5. The gap between the second hole and the shaft member is formed with a gap through which a part of the material of the molten outer peripheral surface side of the shaft member and the resistance portion can flow. The process cartridge according to claim 1.   6. The process cartridge according to claim 1, wherein the portion on the outer peripheral surface side of the position where the shaft member is fitted with the second hole and the resistance portion are made of a thermoplastic resin. The position of the third hole is different from the position of the portion where the second hole and the shaft member are welded with respect to the insertion direction. Process cartridge according to.   The process cartridge according to claim 1, wherein one of the first unit and the second unit is a drum unit having a photosensitive drum, and the other is a developing unit having a developing roller.

Images