JP2005055819A - Method for manufacturing electrophotographic photoreceptor drum unit, electrophotographic photoreceptor drum unit and apparatus for machining electrophotographic photoreceptor drum unit - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for manufacturing a high-precision electrophotographic photoreceptor drum unit at a low cost with high manufacturing efficiency, and to provide an electrophotographic photoreceptor drum unit, an image forming apparatus using the electrophotographic photoreceptor drum unit, and an apparatus for machining an electrophotographic photoreceptor drum unit. <P>SOLUTION: When an electrophotographic photoreceptor drum unit is manufactured, a machining step is carried out in which after an edge engagement member with a shaft or bearing is fastened to an edge of a cylindrical member with a photosensitive layer, the shaft or bearing of the edge engagement member is machined. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a method for producing a high-precision electrophotographic photosensitive drum unit used in an image forming apparatus such as an electrophotographic copying machine, a laser beam printer, and a facsimile printing machine, a processing apparatus therefor, an electrophotographic photosensitive drum unit, The present invention relates to an image forming apparatus using an electrophotographic photosensitive drum unit.

  In an image forming apparatus such as an electrophotographic copying machine, a laser beam printer, a facsimile, or a printing machine, a latent image is generally formed on an electrophotographic photosensitive member by charging means and exposure means, and this latent image is further developed by developing means. Develop and visualize the latent image faithfully.

  An electrophotographic photosensitive drum unit (hereinafter referred to as a “drum unit”) generally has a cylindrical member having a photosensitive layer on its surface (generally also referred to as an “electrophotographic photosensitive drum” having a photosensitive layer on a cylindrical substrate). , And end engaging members provided at both ends or one end of the cylindrical member.

  The end engaging member is also commonly referred to as a gear or a flange, and is connected to a cylindrical member at an outer peripheral portion, and has a shaft or a bearing portion (hereinafter also referred to as “shaft” including “shaft” and “bearing”), Through this, the drum unit is supported at a predetermined position in the image forming apparatus, further receives a driving force from the driving means, and has an effect of rotating the electrophotographic photosensitive drum around a predetermined axis with high accuracy.

  The distance between the cylindrical member and the developing means, such as when the cylinder unit of the drum unit is not good, the shaft is eccentric, and when the drum unit is incorporated in the image forming apparatus and rotated, the outer periphery of the drum unit is shaken during image formation. Cannot be kept constant, and unevenness in image density occurs during development, and a good image cannot be obtained. Furthermore, unevenness occurs in the peripheral speed of the outer periphery of the unit, causing image displacement (especially a phenomenon in which the transfer position shifts in color images and blurring color in a color image), and a good image cannot be obtained. Occurs.

  Therefore, in the drum unit, in particular, the cylindrical swing accuracy (difference between the coaxial outer cylindrical diameters of the maximum outer peripheral portion and the minimum outer peripheral portion when rotated with reference to the drum unit axis, “JIS-B0021 18.6.11 Total swing tolerance” The value of (corresponding to) must be reduced. In a monotone and low-resolution electrophotographic apparatus, the cylindrical swing accuracy was about 100 μm, and there was no problem. However, in recent years, the electrophotographic apparatus has been improved in resolution and full color, and the drum unit has high precision. It is requested. Furthermore, in color electrophotographic apparatus, a tandem electrophotographic apparatus using a plurality of drum units arranged in parallel and using a different drum unit for each of yellow, cyan, magenta, and black toners has been developed. High accuracy is required. In an electrophotographic apparatus with high resolution and full color, a drum unit is required to have a cylindrical swing accuracy of 50 μm or less, and in particular, a high accuracy device of 30 μm or less.

  Conventionally, in order to manufacture a drum unit with high cylindrical swing accuracy (equivalent to the total runout tolerance in JIS B0021 circumferential direction), that is, high cylindrical accuracy of the cylindrical member and less shaft eccentricity, It has been practiced to manufacture a joint member with a high processing accuracy and to join it with a more precise joining technique.

As a conventional method of manufacturing a cylindrical member base, for example, an aluminum alloy is extruded and processed into a cylindrical shape by a method such as drawing, and then the accuracy of the cylinder is increased by a correction means and cut into a predetermined length. Furthermore, a method of finishing the outer peripheral surface of the member manufactured by the above method by cutting (for example, see Patent Document 1) has been developed. This method is also called lathe processing. For example, while rotating the central axis of the cylindrical member to be constant, the cutting tool is applied to the outer periphery of the cylindrical member and fed at a constant speed parallel to the central axis. This is a cutting method. However, even when manufactured by the method as described above, the inner peripheral core and the outer peripheral core of the cylindrical member often do not coincide with each other, and uneven thickness of about several microns to several tens of microns is often present. Furthermore, there is known a method of selecting a cylindrical member with accuracy during the manufacturing process and creating a drum unit using only a highly accurate cylindrical member. However, the cost is unavoidable.

  Further, when the end engagement member is joined to a cylindrical member having a large thickness deviation (non-uniformity in the thickness of the cylindrical member) and the center of the outer periphery does not coincide with the center of the inner periphery, the shaft or bearing portion of the end engagement member The center of the cylinder does not necessarily coincide with the center of the outer periphery of the cylindrical member, and the outer periphery of the drum unit rotates eccentrically, causing image defects. Therefore, it is called inlay processing, and a method of processing the inner periphery of the joint portion with the end engaging member of the cylindrical member on the basis of the outer periphery of the cylindrical member (for example, see Patent Document 2) is performed. It is inevitable that time increases and costs increase.

  Many conventional end engaging members are manufactured by molding a resin. In the case of such a manufacturing method, deformation due to shrinkage after molding or the like is unavoidable, and the center of the outer periphery of the end engaging member and the center of the shaft do not match and have variations. Therefore, in order to increase the cylindrical swing accuracy, for example, it is common to perform cutting on the outer peripheral portion with reference to the shaft center to increase the dimensional accuracy of the flange and the concentricity between the outer periphery and the shaft. However, if such a process is performed, it is inevitable that the cost of the end engaging member becomes high.

  In the conventional drum unit manufacturing method, it is necessary to join the cylindrical member and the end engaging member with high accuracy. After assembly, in order to make the center of the shaft of the end engaging member or the bearing portion coincide with the center of the outer peripheral surface of the cylindrical member, high dimensional accuracy is required on the inner periphery of the cylindrical member joint and the outer periphery of the end engaging member. If the fitting is loose, it cannot be joined with high precision, and if the fitting is tight, the cylindrical member is deformed, which causes a decrease in the accuracy of the outer periphery of the drum unit. For this reason, a highly accurate press-fitting device or the like is required. On the other hand, a method of joining at an angle that cancels the eccentricity of the cylindrical member and the end engaging member is known (for example, see Patent Document 3), but the capital investment is large, the production efficiency is reduced, and the cost is increased. Inevitable.

As described above, in order to manufacture a drum unit with high cylindrical swing accuracy, a high-precision cylindrical member, an end engaging member, and further a high joining technique are required, and there is a problem that costs increase.
JP 2002-169421 A Japanese Patent Laid-Open No. 11-242407 JP 2002-91233 A

  The present invention has been made in order to solve the above-described conventional problems, and an object thereof is to provide an electrophotographic photosensitive drum unit having extremely high cylindrical swing accuracy. It is another object of the present invention to provide an electrophotographic photosensitive drum unit manufacturing method and processing apparatus that can be manufactured at a low cost, including equipment investment, and that can greatly reduce the defect occurrence rate. Another object of the present invention is to provide an image forming apparatus using the electrophotographic photosensitive drum unit manufactured by the manufacturing method.

That is, the present invention is as follows.
(1) In the method of manufacturing an electrophotographic photosensitive drum unit including at least a step of assembling an end engaging member having a shaft or a bearing portion to an end of a cylindrical member having a photosensitive layer, the end engaging member is A method of manufacturing an electrophotographic photosensitive drum unit, wherein a processing step of processing a shaft or a bearing portion of the end engaging member is performed after the step of assembling the end portion of the cylindrical member.
(2) In the processing step, the shaft of the end engaging member or the bearing portion is the center of the cylinder member outer circumference reference in a state where the electrophotographic photosensitive drum unit is rotated around the center axis of the cylinder member outer circumference reference. The method for producing an electrophotographic photosensitive drum unit according to (1), which is a step of processing into a similar circular shape having the same central axis as the axis.
(3) The method for manufacturing an electrophotographic photosensitive drum unit according to (1) or (2), wherein the processing step is performed by cutting or grinding.
(4) In the processing step, a plurality of rollers are arranged so as to contact the outer peripheral surface of the cylindrical member to support the cylindrical member, and at least one of the plurality of rollers is driven to rotate the cylindrical member. The method for producing an electrophotographic photosensitive drum unit according to (2) or (3), wherein the process is performed in a state of being caused to occur.
(5) Of the plurality of rollers, when the roller group that shares the rotation axis and supports both ends of the cylindrical member on the same bus is taken as one set, in the processing step, three or more sets of roller groups become cylindrical members. Two sets of roller groups abut on the different buses on the outer peripheral surface of the cylindrical member at a position lower than the cylindrical member outer peripheral reference central axis to support the cylindrical member substantially horizontally, and one set of roller groups (4) The electrophotographic photosensitive member according to (4), wherein the electrophotographic photosensitive drum unit is rotated by abutting at a position higher than the reference central axis of the outer periphery of the cylindrical member and driving one or more rollers therein. Drum unit manufacturing method.
(6) In the processing step, a position where the shaft or the bearing portion of the end engaging member is processed contacts the cylindrical member outer peripheral reference central axis of the electrophotographic photosensitive drum unit and a different bus bar so that the cylindrical member is substantially 45 degrees or more and 135 degrees or less with respect to the straight line that bisects the angle between the two pairs of rollers that are horizontally supported and the angle between the two ends of the cylindrical member that connects the position where the roller contacts the roller. (5) The manufacturing method of the electrophotographic photosensitive drum unit which is direction.
(7) A cylindrical member of the electrophotographic photosensitive drum unit is centered on the outer peripheral reference central axis, and is placed on one end of the cylindrical member of two sets of rollers that contact the different buses and support the cylindrical member substantially horizontally. The angle obtained by dividing the angle between the straight lines connecting the positions where the rollers abut with each other into two is θ (degrees), and the roundness of the end part before processing of one of the outer circumferences of both ends of the cylindrical member abutting the roller is In the method of manufacturing an electrophotographic photosensitive drum unit, A (μm), the other end roundness before processing is B (μm), and the cylindrical degree before processing of the cylindrical member is C (μm). The method for producing an electrophotographic photosensitive drum unit according to (5) or (6), wherein the following formula is satisfied.
0 ≦ (Asinθ + Bsinθ + C) ≦ 50 μm
(8) The electrophotographic photosensitive member according to any one of (2) to (7), wherein in the processing step, the shaft or the bearing portion of the end engaging member is processed simultaneously from the ends on both sides of the cylindrical member. Manufacturing method of body drum unit.
(9) An electrophotographic photosensitive drum unit manufactured by any one of the methods (1) to (8).
(10) Cylindrical swing of the electrophotographic photosensitive drum unit based on the end engaging member axis or the bearing center axis after being processed into a similar circle having the same center axis as the center axis of the cylindrical member outer circumference reference The electrophotographic photosensitive drum unit manufactured by any one of the methods (4) to (8), wherein the accuracy is 50 μm or less.
(11) In an image forming apparatus having an electrophotographic photosensitive drum unit, a charging unit, an exposing unit, a developing unit, and a transferring unit, the electrophotographic photosensitive drum unit according to any one of (1) to (8) An image forming apparatus.
(12) An apparatus for processing an electrophotographic photosensitive drum unit, wherein an end engaging member having a shaft or a bearing portion is assembled, and a cylindrical member having a photosensitive layer is brought into contact with an outer peripheral surface of the cylindrical member. Support means for arranging and supporting a plurality of rollers, rotation means for driving at least one of the plurality of rollers to rotate the cylindrical member, shaft of the end engaging member assembled to the cylindrical member Alternatively, an electrophotographic photosensitive drum unit processing apparatus having processing means for processing the bearing portion.

  The drum unit manufactured by the drum unit manufacturing method of the present invention has high cylindrical swing accuracy, and good dimensional accuracy and surface roughness of the shaft or the bearing portion.

  Further, the drum unit of the present invention rotates without shaking when attached to the image forming apparatus, and a good image can be obtained without image unevenness and image misalignment during development and transfer.

  The drum unit processing apparatus of the present invention can manufacture a highly accurate drum unit using a cylindrical member and an end engaging member manufactured at low cost. Manufacturing costs such as joining accuracy, yield, equipment cost and maintenance cost of the cylindrical member and the end engaging member can be reduced, and the manufacturing cost of the electrophotographic photosensitive drum unit can be greatly reduced.

  Use of the drum unit of the present invention for an electrophotographic photosensitive member substrate can greatly contribute to high performance and low cost of the image forming apparatus.

  In the manufacturing method of an electrophotographic photosensitive drum unit configured by assembling an end engaging member having a shaft or a bearing portion to a cylindrical member end having a photosensitive layer, the end engaging member is assembled to the cylindrical member. An electrophotographic photosensitive drum unit (hereinafter, also simply referred to as “drum unit”) manufacturing method comprising a step of processing a shaft of the end engaging member after the attaching step.

  In the drum unit manufacturing method of the present invention, the shaft is processed after the drum unit is assembled. Even if the accuracy of the individual parts of the cylindrical member and the end engaging member is low, or the cylindrical member and the end engaging member Even if the joining accuracy is low, a highly accurate drum unit is obtained by processing after assembly.

As an example of processing contents in the drum unit manufacturing method of the present invention, it is particularly effective for the centering processing of the shaft and the bearing portion of the drum unit, but the outer peripheral portion, the inner peripheral portion, and the end portion of the single shaft portion of the end engaging member. Each length, diameter, chamfer, depth, roundness, straightness, cylindricity and other dimensional accuracy, surface roughness, and the like can be applied to processing that matches predetermined specifications. In the drum unit manufacturing method of the present invention, if the outer diameter accuracy of the cylindrical member is good, other accuracy, for example, thickness deviation of the cylindrical member, concentricity, dimensional accuracy of the inner diameter portion of the cylindrical member, roundness, When assembling the eccentricity of the shaft or bearing of the end engaging member, dimensional accuracy, roundness, surface roughness, dimensional accuracy of the outer periphery of the end engaging member, roundness, cylindrical member, and end engaging member The degree of coaxiality and dimensional accuracy of the shaft or bearing portion and the outer periphery of the cylindrical member are greatly relaxed.

  Examples of the processing step used in the method for manufacturing a drum unit of the present invention include a method performed by cutting, grinding, or the like. Examples of tools used for cutting include lathe tools, end mills, drills, and the like, and examples of tools used for grinding include grinding wheels. Examples of the material of the lathe tool include cemented carbide, single crystal diamond, sintered diamond, and special steel. There is an example in which the machining process is performed in two stages of rough cutting and finish cutting.

  In the method for manufacturing a drum unit of the present invention, “centering” is performed so that the axis of the end engaging member or the center axis of the bearing portion is close to the center axis of the cylindrical member outer circumference reference, that is, both Processing the shaft portion of the end engaging member so that the central shaft has a similar circular shape having the same central shaft.

  The drum unit of the present invention is processed into a concentric shape (continuous state of similar circles having the same center axis as the reference axis of the outer periphery of the cylindrical member), and is then electrophotographic on the basis of the center axis of the end engaging member axis. It is preferable that the cylindrical swing accuracy of the photosensitive drum unit is 50 μm or less. In particular, in a drum unit that requires high accuracy, it is particularly preferable that the cylindrical swing accuracy be 30 μm or less.

  The cylindrical swing accuracy of the electrophotographic photosensitive drum unit is determined by the cylindricality of the electrophotographic photosensitive drum and the coaxiality between the electrophotographic photosensitive drum and the shaft portion. For this purpose, the sum of the cylindrical degree of the electrophotographic photosensitive drum unit and the coaxiality of the electrophotographic photosensitive drum unit and the shaft portion needs to be less than or equal to the approximate cylindrical swing accuracy. The cylindricity of the electrophotographic photosensitive drum is determined by the processing accuracy of the cylindrical member. However, the coaxiality between the electrophotographic photosensitive drum unit and the shaft portion can be increased by the method of the present invention, and the cylindrical swing accuracy is 50 μm or less. Make it possible.

  In the present invention, the cylindrical swing accuracy is measured as follows. The drum unit is fixed with right or left shafts or shafts or bearings suitable for bearings, and a laser run-out measuring machine (a laser measuring machine that measures the distance between a reference gauge with a straightness of 3 μm or less and the outer circumference of a cylindrical member with a resolution of 1 μm. (For example, Shinko Co., Ltd.) measures the displacement of the surface of the drum unit image area at 10 points in the drum unit bus direction and the circumferential direction, and calculates the cylindrical swing accuracy by data processing).

  The coaxiality is determined by measuring the outer circumference of the cylindrical member of the electrophotographic photosensitive drum unit with a roundness meter to obtain the axis of the cylindrical member, and rotating the drum unit about the axis of the outer circumference of the cylindrical member while rotating the drum unit around the cylindrical member and the shaft. The center of the part is measured with a roundness meter to determine the axis and calculated from it.

  In the drum unit manufacturing method of the present invention, particularly when centering the shaft of the end engaging member or the bearing portion, the drum unit is rotated around the central axis of the outer periphery of the cylindrical member, and the machining tool is pivoted in the machining process. A method of processing concentrically by hitting (or a bearing portion) is particularly preferable. This method is preferable because it can be processed concentrically by simply applying a cutting tool to the rotating shaft (or bearing portion), the equipment investment is small, and adjustment during processing is easy.

There is also a method of attaching the drum unit to the support, measuring the axis of both the drum unit and the processing tool, aligning them, and then machining the shaft with a rotating cutting tool. Necessary and disadvantageous in cost. Examples of simple shaft (or bearing) processing include an example in which the drum unit is fixed and the processing tool is rotated, an example in which the processing tool is fixed and the drum unit is rotated in processing, and an example in which both are moved to perform processing.

  When centering is performed in the drum unit manufacturing method of the present invention, the surface of the shaft (or bearing portion) of the end engaging member is rotated with the center axis as the reference of the outer periphery of the cylindrical member. It is more preferable to process concentrically with the outer periphery. As a method of rotating the drum unit around the central axis with respect to the outer periphery of the cylindrical member, the drum unit is supported by an apparatus in which a plurality of support rollers are arranged along the outer peripheral surface of the cylindrical member, and at least one of the plurality of rollers is supported. By rotating the drum unit by driving the roller, it is possible to easily rotate the drum unit around the center axis as the reference of the outer periphery of the cylindrical member without a costly process such as accuracy measurement with a simple device. Furthermore, the shaft or the bearing portion can be easily processed concentrically with the outer periphery of the cylindrical member by pressing the rotating shaft or bearing portion tool of the drum unit.

  The example of the processing apparatus used for the manufacturing method of the drum unit of this invention is described. 1 and 2 are schematic configuration diagrams of a processing apparatus used in the processing method of the electrophotographic photosensitive drum unit of the present invention, FIG. 1 is a front view, and FIG. 2 is a side view.

  In the example of the processing apparatus of the present invention, the drum unit 6 is supported by applying three sets of support rollers 3 a, 3 b, 4 a, 4 b, 5 a, and 5 b along the outer peripheral surface 2 of the cylindrical member 1. In FIG. 1, 3a, 3b and 3c are not shown. In FIG. 1, the rollers 3a, 4a, and 5a are arranged to abut one end of the cylindrical member, and the support rollers 3b, 4b, and 5b are arranged to abut the other end of the cylindrical member. Each of the support rollers is fixed to the processing apparatus by shafts 3c, 4c, and 5c that are set substantially parallel to the central axis that is the outer periphery of the cylindrical member, and is set so as to rotate smoothly around the shaft. 3a and 3b, 4a and 4b, 5a and 5b rotate with a common axis.

  The supporting rollers 3a, 3b, 4a and 4b which are lower than the outer peripheral center line of the cylindrical member are not driven, but have a function of supporting the drum unit with high accuracy, so that the shaft is strong enough to support the drum unit. 3c, 4c are required. Examples of the material include a metal rod such as iron or aluminum, or a pipe, and it is necessary to receive the bearing with a bearing such as a high-precision bearing or sintered metal. Further, it is preferable to use a highly accurate roller member. For example, it is preferable to use a metal material that does not easily wear, such as stainless steel or high carbon low chromium steel, or a resin such as polyester resin, urethane resin, or acrylic resin.

  Among the supporting rollers, rollers 5a and 5b (hereinafter, 5a and 5b are referred to as “driving rollers”) that are in contact with a position higher than the cylindrical member outer peripheral reference central axis are referred to as driving means including a motor 7a and power transmission means 7b and 7c. Thus, the surface material having a frictional resistance sufficient for driving the drum unit is selected. Examples of such a surface material include rubbers such as natural rubber and butadiene rubber, and resin materials such as urethane and polyester. Further, it is preferable that the frictional resistance of the surface of the support roller for rotating the cylindrical member is high.

  The support rollers 3a, 3b, 4a, 4b and the drive rollers 5a, 5b are arranged so that the drum unit 6 is rotated about the central axis 8. The position where the support roller and the driving roller are in contact with the surface of the cylindrical member is preferably an end portion of the cylindrical member avoiding an area related to image formation.

Furthermore, the vibration of the drum unit rotating shaft can be reduced by contacting the supporting roller and the driving roller in the vicinity of both ends of the cylindrical member. With the drum unit rotating, the tools 10a and 11b are respectively applied to the shafts 10a and 10b of the engaging members 9a and 9b (in the illustrated example, the outer periphery of the shaft) so as to be processed concentrically with the outer periphery 2 of the cylindrical member. Tools 11a and 11b are installed. The processing tools 11a and 11b are fixed to the tool bases 12a and 12b, and the tool bases are on the rails 13a and 13b, and can be moved along the shaft (or bearing portion) processing surface as necessary. Furthermore, in order to prevent the drum unit 6 from swinging in the direction parallel to the central axis of the cylindrical member (the left-right direction in FIG. 1), it is also preferable to include shake prevention rollers 14a and 14b in contact with the drum unit side surface.

  When the drum unit 6 is taken in and out, the driving rollers 5a and 5b can be released. In the present invention, as shown in FIGS. 3, 4, and 5, the structure of the processing part can be a structure corresponding to the structure of the shaft (or bearing part) and the processing place.

  A method for manufacturing a drum unit using the processing apparatus shown in FIGS. The drum unit is placed on the support rollers 3a, 3b, 4a and 4b, and the drive rollers 5a and 5b are pressed to hold the drum unit. Next, the drive rollers 5a and 5b are driven, and the drum unit 6 is rotated about the central axis 8 with the outer periphery of the cylindrical member as a reference. In this state, the processing tools 11a and 11b are pressed against the shafts 10a and 10b of the engaging members 9a and 9b (in the illustrated example, the outer periphery of the shaft), and the surfaces of the shafts 10a and 10b of the end engaging member are concentric with the outer periphery 2 of the cylindrical member. Can be processed. The tool stands 12a and 12b are on the rails 13a and 13b, and are moved along the axial surface to process a predetermined portion. At the time of machining, machining time can be shortened by machining the tool 11a from the right and 11b from the left and simultaneously scanning while scanning. After the machining tool is scanned and machining is completed over the entire length of the shaft portion, the holding of the drive rollers 5a and 5b to the drum unit 6 is released with the cutting tool moved and retracted. It is carried out.

  In the drum unit manufacturing method of the present invention, the cylindrical member is supported by applying a plurality of support rollers to the outer periphery of the cylindrical member. The number of support rollers is preferably two or more sets of support rollers arranged along the outer periphery of the cylindrical member when one set sharing the shaft and supporting both ends on the same bus is used. One of the groups is preferably a roller group having a driving roller for rotating the cylindrical member. Furthermore, in the present invention, two sets of non-driven support rollers are provided at a position lower than the height of the cylindrical member outer peripheral reference center line 8, and the support rollers are applied to and supported by the outer periphery of the cylindrical member. It is preferable to rotate the drum unit 6 by driving one or more drive rollers 5 positioned higher than the reference center line.

  The support roller at a position lower than the cylindrical member outer peripheral reference center line 8 plays an important function to ensure the drum unit cylindrical swing accuracy, and the support roller cylindrical swing accuracy has a significant effect on the drum unit finish accuracy. Therefore, it is preferable that the selection is made with an emphasis on the accuracy of the cylindrical swirling of the outer periphery. On the other hand, the driving roller located higher than the cylindrical member outer peripheral reference center line can be selected to focus on the function of rotating the drum unit at a constant speed, so that the drum unit 6 can be stably rotated. A high drum unit can be manufactured.

  In the present invention, the angle between the straight lines 16a and 16b connecting the contact positions of the support rollers 3 and 4 that are in contact with the two sets of different buses with the cylindrical member outer peripheral reference central axis 8 of the drum unit as a central point. A straight line 15 that bisects 2θ is made to coincide with a perpendicular line perpendicular to the central axis of the cylindrical member outer periphery as shown in FIG. 2 (the support rollers 3 and 4 contact positions are arranged symmetrically about the perpendicular line) Is preferable. With this configuration, it is possible to further stabilize the rotation of the drum unit 6 and to manufacture a drum unit with higher runout accuracy.

As shown in FIG. 2, the cutting position or the grinding tool (hereinafter referred to as “cutting tool” or “grinding tool” as a representative of “cutting tool”) on the shafts 10a and 10b is processed. The angle between the straight lines 16a and 16b connecting the contact positions of the two sets of support rollers 3 and 4 that are in contact with the outer periphery of the cylindrical member of the drum unit and the cylindrical member outer peripheral reference central axis is divided into two equal parts. Most preferably, the cutting tool is applied to the shaft in the direction of 90 degrees with respect to the straight line 15. 1 and 2, for example, when processing a cylindrical member having a large outer diameter due to variations in the outer diameter of the cylindrical member, the drum unit is supported by a support roller from below, so that the rotation axis is a straight line 15. Move in the upward direction (upward). If the cutting tool is in contact with the straight line 15 in the direction of 90 degrees, there is an effect that the variation in the distance between the cutting edge of the cutting tool and the cylindrical reference outer peripheral reference axis is small and the change in the shaft diameter after machining is small. It is done. That is, even if there is a variation in the outer diameter of the cylindrical member, it is possible to suppress variations in the shaft diameter after processing. The angle between the bisector (straight line 15) sandwiched between the straight lines 16a and 16b and the direction in which the cutting tool is applied (straight line 17) is in the direction of 45 to 135 degrees, particularly in the direction of 75 to 105 degrees. Thus, the effect of the present invention can be obtained.

In order to stably produce at a high yield in the method for producing a drum unit of the present invention, it is preferable to satisfy the following points.
(1) As shown in FIGS. 1 and 2, two sets of support rollers 3a and 3b, 4a and 4b, which are in contact with the cylindrical member outer periphery at a position lower than the cylindrical member outer peripheral reference center line 8 on different buses, The cylindrical member supports the vicinity of both ends (in FIG. 1, the contact portions of 4a and 4b with respect to the cylindrical member are 2a and 2b).
(2) Further, the support rollers 3a and 4a, 3b and 4b support the same circumference (2a and 2b in FIG. 1) near the end of the cylindrical member.
(3) The processing tools 11a and 11b have two sets of support rollers 3 (3a and 3b) and 4 (4a and 4b) arranged at a position lower than the central axis 8 with the cylindrical member outer peripheral reference central axis 8 as a central point. ) Is applied to the circumference of the axis (or bearing portion) in the direction of approximately 90 degrees with respect to the straight line 15 that bisects the angle 2θ between the straight lines (16a, 16b) that connect the contact positions of).

In the drum unit manufacturing method satisfying the above (1), (2), and (3), the drum unit is arranged at a position lower than the central axis 8 with the cylindrical member outer peripheral reference central axis 8 as a central point as shown in FIG. A straight line 15 that bisects an angle 2θ sandwiched between straight lines (16a, 16b) connecting the contact positions of the two sets of support rollers 3 and 4 and a straight line connecting the contact positions of the two sets of the support rollers 3 and 4 (16a, 16b) is the two angles between θ (degrees), the roundness of one end 2a of the cylindrical member outer periphery with which the support roller is in contact before processing is A (μm), the other In the manufacturing method of the electrophotographic photosensitive drum unit in which the roundness before processing of the end portion 2b is B (μm) and the cylindricality before processing of the cylindrical member is C (μm), the following formula is satisfied. preferable.
0 ≦ (Asinθ + Bsinθ + C) ≦ 50 μm
In the present invention, the processing apparatus shown in FIGS. 1 and 2 will be described as an example. If the runout of the support rollers 3a, 3b, 4a, and 4b is sufficiently small, the runout width of the rotating drum unit shaft is the outer diameter of the cylindrical member. It is the same as the fluctuation range. Consider the end supported by the support rollers 3a, 4a. The roundness is the difference between the maximum and the minimum of the outer peripheral radius of the cylindrical member outer peripheral central axis, and the runout of the drum unit shaft during rotation is the cylindrical member roundness A (at the position supported by the support rollers 3a and 4a). μm). Furthermore, when the distance between the end of the drum unit and the processing part of the shaft (or bearing) is short, the amount of deflection at the center of rotation of the shaft 10a matches the amount of rotation at the end of the cylindrical member supported by the support rollers 3a and 4a. To do. Further, of the runout of the drum unit shaft, the direction in which the processing tools 11a and 11b are applied to the shaft (the straight line 16a connecting the contact position of the support rollers 3 and 4 and the cylindrical member outer peripheral reference central axis in the processing apparatus of FIGS. , 16 b, the vector component of the direction of approximately 90 degrees with respect to the straight line 15 that bisects the angle 2θ between two parts) is expressed as A (
μm) multiplied by sinθ.

  Therefore, the vibration during rotation of the drum unit and the variation in the distance between the rotation shaft and the cutting member are also Asinθ, and the deflection accuracy and roundness after processing of the drum unit shaft are also Asinθ. Similarly, the outer peripheral portion that contacts the supporting rollers 3b and 4b that support the other end also has a roundness and a shake accuracy after processing of Bsin θ (μm). The shake amounts of the shafts 10a and 10b after processing are Asinθ and Bsinθ, respectively. Here, considering only the shaft runout, when the shafts 10a and 10b after processing are rotated as a reference, the maximum value of the shaft swing is Asinθ on the 10a side and Bsinθ on the 10b side. Assuming that the shaft portions 10a and 10b touch each other in the opposite direction, the maximum value of the shaft swing is Asinθ + Bsinθ.

  Further, when the cylindricity C, which is a deflection component of the entire cylindrical member, is added, the maximum value of the drum unit cylindrical swing accuracy after processing becomes (Asinθ + Bsinθ + C).

  In other words, the cylindrical swing accuracy of the drum unit is defined as A (μm) and B (μm), respectively, of the roundness of the cylindrical member before processing at the portions where the support rollers are in contact with the left and right ends, respectively, In the method of manufacturing an electrophotographic photosensitive drum unit in which C is (μm), it is preferable that 0 ≦ (Asin θ + Bsin θ + C) ≦ 50 μm. More preferably, it is more preferable that 0 ≦ (Asin θ + Bsin θ + C) ≦ 30 μm. Thereby, the cylindrical swing accuracy of the drum unit after processing can be 50 or less, preferably 30 or less.

  In the present invention, it is possible to manufacture a drum unit having a high cylindrical swing accuracy even when a cylindrical member having the same accuracy is used when the angle θ is smaller. Even if the roundness of the cylindrical member is the same and A, the shaft runout after processing has a small value in proportion to sinθ. For example, if the angle θ is 70 degrees, the shaft runout after machining is 0.94 times A, 60 degrees is 0.71 times A, and 20 degrees is 0.342 times A. However, if the angle θ is too small, it becomes unstable when a force is applied in the horizontal direction. For example, the force when the machining tool is applied to the shaft makes it easier for the rotating shaft to move in the direction opposite to the direction in which the machining tool is applied. If the angle θ is too large, the rotation axis of the drum unit is likely to move in the vertical direction when a force is applied in the vertical direction. For example, there arises a problem that the rotating shaft is likely to fluctuate downward due to the reaction force when the shaft portion is cut by a processing tool. A drum unit having a good balance and high runout accuracy is preferable at 20 ° to 70 °.

  In the present invention, the roundness of the cylindrical member can be obtained by measuring the portion supported by the support roller. Usually, a cylindrical member is fixed to a measuring table of a roundness meter and the core is adjusted, and then the outer circumference (inner circumference) shape is measured with a stylus and the roundness is calculated from the value. A series of steps in the measurement is automatically measured using a roundness meter (for example, model: RA-662: manufactured by Mitutoyo Corporation). The cylindricity is measured for the entire image area of the electrophotographic photosensitive drum. Measurement points are preferably 10 points rather than 5 points. The cylindricity can also be automatically measured using a roundness meter.

  The roundness and cylindricity of the shaft (or bearing) part are measured with respect to the fitting part with the main body, and the drum unit is usually fixed to the measuring table of the roundness meter and the core is adjusted, and then the shaft is touched with a stylus. In this case, the outer circumference (inner circumference in the case of a bearing) is measured, and the roundness and cylindricity are calculated from the measured values. A series of steps in the measurement is automatically measured using a roundness meter (for example, model: RA-662: manufactured by Mitutoyo Corporation).

  The concentricity between the cylindrical member and the shaft (or bearing) portion is calculated from the value obtained by measuring the outer circumference of the cylindrical member and the center of the shaft (or bearing) portion with a roundness meter.

In the present invention, the dimensional accuracy of the shaft portion (bearing portion) needs to be processed so as not to be loose when incorporated in the image forming apparatus. In general, in an image forming apparatus that requires a drum unit having a cylindrical swing accuracy of 50 μm or less, the fitting accuracy of the coupling portion between the image forming apparatus main body and the drum unit is required to be 30 μm or less. In the present invention, the shaft portion diameter dimensional accuracy is 30 μm or less. More preferably, 20 μm can be achieved.

  Examples of the method for measuring the inner diameter in the present invention include a method using a caliper, a plug gauge, a cylinder gauge, a caliper gauge, and the like, and a method using a plug gauge that does not easily damage the processed part is particularly preferable. Regarding the method of measuring the outer diameter, a method using a vernier caliper, a micrometer, a caliper gauge or the like can be mentioned, and a method using a micrometer is particularly preferable.

  In the present invention, the entire unit length (distance between the tip portions of the shafts (bearing portions) on both sides) can be processed with high accuracy regardless of the accuracy and joining accuracy of the cylindrical member and the engaging member.

  In the method of manufacturing a drum unit according to the present invention, an example in which a tool with a flat tip is pressed against a portion to be machined, scanning is performed by an apparatus having a tool movement scanning means along the shaft of the end engaging member or the surface of the bearing portion. An example of processing is given. The latter is preferable because a better machined surface can be obtained and a more complicated shaft or bearing can be machined.

  In the drum unit manufacturing method of the present invention, when the engaging members are assembled to both ends of the cylindrical member and the end engaging members on both sides have shafts (or bearing portions), these two shafts (or bearing portions) Corresponding to the above, a processing tool and its adjusting means are provided on both sides, and the shaft (or bearing portion) of the end engaging member can be processed at the same time from both sides, thereby increasing the production efficiency. Furthermore, it is preferable that the tool scanning direction is opposite to the left and right, since the deflection of the drum unit in the left and right direction is reduced and the accuracy is improved.

  In the present invention, if the cylindrical member used in the drum unit is finished with a high degree of roundness and cylindricity on the outer periphery, the requirements for the unevenness, the roundness of the inner diameter, and the cylindricity are not so high. Manufacture can be made by a low cost method.

  Examples of the cylindrical member manufacturing method used in the present invention include a method of manufacturing a cylinder with a bottom by processing into a cup shape by deep drawing and then extending the wall of the cup by ironing (DI method), impact extrusion processing The cup wall is then stretched by ironing to produce a bottomed cylinder (Method II), and the cylinder obtained by extrusion is stretched by ironing to produce a thin cylinder (EI) Method), a method of producing a thin-walled cylinder by drawing after the extrusion (ED method), and the like. Moreover, the example of the cylindrical member manufactured by raising the precision of the hollow pipe extruded by the porthole system by the drawing process of 1 step | paragraph or 1 step | paragraph or more is also mentioned. The cylindrical member is cut, and both end portions are subjected to deburring processing, end taper processing, and cutting inlay processing (processing for finishing the inner peripheral portion of the end portion with a certain width and finishing with high accuracy).

  The cylindrical member used in the present invention may be used by processing the end after obtaining the cylinder by drawing after extrusion of the aluminum alloy, but the outer periphery may be processed as necessary. . In order to further increase the roundness and cylindricity of the outer periphery of the cylindrical member obtained by the above method, a method of cutting and grinding the outer periphery as necessary may be performed. In particular, as a means for obtaining a cylindrical member having high roundness and cylindricity on the outer periphery, cutting, particularly lathe processing is preferable.

  In the present invention, examples of the material for the cylindrical member include metals such as aluminum, copper, iron, nickel, titanium, and alloys thereof, and those obtained by conducting a conductive treatment on plastic, ceramic, glass, and the like. Preferably, 3000 (Al—Mn), 5000 (Al—Mg), or 6000 (Al—Mg—Si) aluminum or aluminum alloy is used.

  When the end engaging member used in the present invention is used in a drum unit, the drum unit manufacturing method of the present invention can be used even if it has a lower level of accuracy than that used in the conventional method of manufacturing a high precision drum unit. By applying, a highly accurate drum unit can be obtained. If the roundness of the outer circumference and the dimensional accuracy are finished to the specified accuracy, the unevenness and the roundness of the inner diameter of the shaft (or bearing part) are not important. Can be manufactured. If necessary, cutting or grinding may be performed after molding. The end engaging member has a shaft, a bearing, a cylindrical member and a shaft, a flange portion connecting the bearing, and a gear for receiving a driving force as required.

  The joining accuracy of the cylindrical member and the end engaging member used in the present invention can be improved by applying the drum unit manufacturing method of the present invention even if the accuracy is lower than the standard of the conventional method of manufacturing a high-precision drum unit. An accurate drum unit can be obtained. Even with an accuracy level obtained by normal bonding and press-fitting, it is possible to manufacture a drum unit with higher accuracy.

  The shaft (or bearing portion) of the end engaging member used in the present invention is made in advance in a dimension that takes into account a machining allowance for performing processing for obtaining cylindrical swing accuracy and bearing portion dimensional accuracy after assembling the drum unit. It is preferable to keep.

  3A, B, C, A, B, C in FIG. 4 and A, B, C in FIG. 5, examples of the shape and processing of the shaft (or bearing portion) of the end engaging member used in the present invention. Indicates. 3A and 3B are shaft shape examples, FIG. 3A is a side view, and FIG. 3B is a plan view (viewed from above). The engaging member 9 is joined to the cylindrical member 1. After assembly, the shape is 19 but the shaded portion (shaft outer periphery and end) is cut to obtain a predetermined shaft shape 18. FIG. 3C is a plan view of an example of processing. A tool (bite) 11 is fixed to a tool base 12 and can press the tool against a shaft (in the example of the figure, the outer periphery of the shaft) to process the shaft surface of the end engaging member concentrically. The tool stand 12 is on the rail 13 and moved along the axial surface to process a predetermined portion and retract after the processing. Similarly, A, B, and C in FIG. 4 are bearing portions, and A, B, and C in FIG.

  The cylindrical member used in the present invention may be applied with a known surface treatment, an undercoat layer, and a conductive layer for the purpose of preventing injection, preventing interference fringes, protecting surface defects, and the like, if necessary.

  Examples of the photosensitive layer of the cylindrical member used in the present invention include those used for inorganic photoreceptors, organic photoreceptors, and the like, and are not particularly limited. As a layer structure, a single layer type or a laminated structure type can be used. Examples thereof include those having a protective layer on the photosensitive layer.

  The cylindrical swing accuracy of the drum unit of the present invention is required to be 50 μm or less, more preferably 30 μm or less, in order to prevent multicolor image misalignment, image unevenness and the like in applications such as full-color printing.

  The drum unit manufacturing method of the present invention can provide a drum unit with high cylindrical swing accuracy. The drum unit with high cylindrical swing accuracy of the present invention rotates when the outer periphery is not shaken when mounted on an image forming apparatus, and a good image can be obtained without image unevenness and image shift during development and transfer. To preferred.

  The drum unit processing apparatus according to the present invention makes it possible to manufacture a highly accurate drum unit using a cylindrical member and an end engaging member manufactured at low cost.

  The electrophotographic photosensitive drum unit manufacturing method and processing apparatus of the present invention are other cylindrical members used in the image forming apparatus and members having a shaft (or bearing portion), such as a developing sleeve, a charging roller, a feeding roller, a fixing roller, etc. It can also be applied to.

Next, the present invention will be specifically described with reference to the following examples, but the present invention is not limited to these examples. In the examples, “part” indicates mass part, and the definition of the accuracy measurement tolerance in the examples is based on JIS-B0021 and JIS-B0621.
[Example 1]
The hollow pipe (made of aluminum alloy JIS-A3003) manufactured by extrusion and further drawing was cut to obtain a cylindrical member having an outer diameter of 60.4 mm, an inner diameter of 58.6 mm, and a length of 344 mm. Next, both ends were cut by cutting to adjust the overall length and the perpendicularity of the end face, and further chamfered with C0.3 on the inside and outside, respectively. As a result of the accuracy measurement, the cylindrical member was fixed on the surface plate and measured with a right angle measuring instrument Skoya Master (manufactured by Mitutoyo Corporation). As a result, the squareness of the end face was 150 μm or less. The end face parallelism was 30 μm or less as a result of measuring with a height gauge (manufactured by Mitutoyo Corporation) with a cylindrical member fixed on a surface plate.

  Next, the outer peripheral surface of the cylindrical member was cut by a lathe processing apparatus. The machining conditions were a cylindrical member rotation speed of 3000 rpm, a feed pitch per rotation of the cylindrical member was 0.1 mm / rev, and first, rough cutting was performed with an R0.2 sintered diamond tool cutting depth of 0.2 mm. Further, finishing was performed with an R4 sintered diamond cutting tool with a cutting depth of 0.03 mm. The obtained cylindrical member had an outer diameter of 59.94 mm and a length of 340 mm. Surface roughness Rz = 0.60 μm (surface roughness meter: measured using a surface roughness meter Surfcorder SE3500, Kosaka Laboratory, with a cutoff of 0.8 mm and a measurement length of 8 mm) was obtained.

Next, the following photosensitive layer was formed on the cylindrical member substrate. SnO ₂ coating treatment 10 parts of barium sulfate, 3 parts of titanium oxide, 6 parts of phenolic resin, 4 parts of methanol, and 20 parts of methoxypropanol are prepared. A conductive layer coating solution is prepared and applied to the resulting cylindrical member substrate. Then, it was thermally cured at 140 ° C. for 30 minutes to form a conductive layer having a thickness of 15 μm.

  Next, polyamide resin (trade name: Amilan CM8000, manufactured by Toray Industries, Inc.) 8 parts, methoxymethylated 6 nylon resin (trade name: Toresin EF-30T, Teikoku Chemical Co., Ltd.) 12 parts, methanol 300 parts and n-butanol 250 An undercoat layer having a film thickness of 0.7 μm was formed by applying a coating material dissolved in a part of the mixed solvent and drying with hot air at 95 ° C. for 13 minutes.

  Next, after dispersing a solution comprising 7 parts of an azo pigment, 5 parts of polyvinyl butyral resin (trade name: BX-1, manufactured by Sekisui Chemical Co., Ltd.) and 70 parts of cyclohexanone for 8 hours with a sand mill using glass beads, ethyl acetate 100 parts was added to prepare a dispersion for the charge generation layer. This dispersion was applied onto the intermediate layer and dried by heating at 95 ° C. for 10 minutes to form a charge generation layer having a thickness of 0.21 μm.

  Next, 8 parts of an amine compound of the following structural formula,

3 parts of an amine compound of the following structural formula,

And 10 parts of bisphenol Z-type polycarbonate resin (trade name: Iupilon Z-200, manufactured by Mitsubishi Gas Chemical Company) were dissolved in a mixed solvent of 80 parts of monochlorobenzene and 20 parts of dimethoxymethane. This paint was applied onto the charge generation layer and dried at 130 ° C. for 1 hour to form a charge transport layer having a thickness of 15 μm.

  The obtained cylindrical member after application of the photosensitive layer had an outer diameter of 60.0 mm and a length of 340.0 mm. The results are shown in Table 1. Using a roundness meter (model: RA-662: manufactured by Mitutoyo Corporation), 5 mm portion (A in Table 1) and one end of the outer peripheral surface from one end of the outer peripheral surface of the obtained cylindrical member Further, the roundness (difference between the maximum circumscribed circle and the maximum inscribed circle) of the 5 mm portion (B in Table 1) was measured. The measured results are shown in Table 1. Furthermore, by using a roundness meter (RA-662: manufactured by Mitutoyo Corporation), the outer diameter of 8 points is measured every 50 mm from 5 mm from one end of the outer peripheral surface to obtain cylindricity, and the results are shown in Table 1. Indicated.

  Furthermore, as a result of measuring the inner circumference accuracy using a roundness meter (RA-662: manufactured by Mitutoyo Corporation) as the accuracy of the cylindrical member, the roundness of the portion 5 mm from the end is 70 μm, and 5 mm from the end of the inner circumference. The roundness of the part is 70 μm, the outer circumference of the part measured using a roundness meter (type: RA-662: manufactured by Mitutoyo Corporation), the outer circumference of the part, the concentricity from the shape of the inner circumference (outer center and inner circumference) As a result of calculating (center distance), it was 70 μm.

  Next, an end engaging member (made of polycarbonate) manufactured by molding was prepared. The shape of the engaging member and the configuration schematic diagram of the processing steps are as shown in FIGS.

The accuracy before processing the end engaging member is as follows. In the following description, the “flange portion” is a portion connecting the outer peripheral portion of the end engaging member and the bearing portion.
Flange part outer diameter 58.4 ± 0.1 mm (micrometer: measured by Mitutoyo Corporation)
Flange thickness 14mm (Caliper: measured by Mitutoyo Corporation)
Roundness of the outer peripheral part of the flange part is 60 μm (7 mm part is measured from the end part using a roundness meter (RA-662: manufactured by Mitutoyo Corporation))
Flange part outer peripheral cylindricity of 65 μm (measured by 2 mm, 7 mm, and 12 mm from the end using a roundness meter (RA-662: manufactured by Mitutoyo Corporation))
Inner diameter before processing of bearing part 19.4 ± 0.2mm (Plug gauge: Measured by Mizonokuchi Seisaku Seisakusho)
Bearing length overhang from flange 21 ± 0.5mm (Caliper: measured by Mitutoyo Corporation)
Bearing part inner circumference roundness within 70 μm (measured with a roundness meter (RA-662: manufactured by Mitutoyo Corporation) 15 mm from shaft end)
Bearing part inner circumference cylindricity within 70μm (Measures 5mm, 15mm, 25mm and 35mm parts from shaft end using roundness meter (RA-662: manufactured by Mitutoyo Corporation))
Concentricity of bearing and flange outer circumference within 70μm (Measure roundness (model: RA-662: made by Mitutoyo Corporation) 25mm from bearing edge and 7mm from flange outer edge)
The prepared end engaging member was attached to the cylindrical member coated with the photosensitive layer, and fixed with a cyanoacrylate adhesive (Aron α: manufactured by Toagosei Co., Ltd.). The drum unit was adjusted so that the end engaging member bearing portion has the following specifications by the processing apparatus shown in FIGS. 1 and 2 described above, and the hatched portion was cut as shown in FIGS. The support roller was in contact with the 5 mm portion from the end portion of the cylindrical member. In the processing apparatus of FIG. 5, the cutting tool 21 is attached to the tool base 12 and can be moved in a parallel and perpendicular manner to the rotation axis of the drum unit by a tool base 12 rail (not shown). First, the cutting tool 21 was first brought into contact with the end of the bearing and moved in a direction perpendicular to the rotation axis of the drum unit, and the entire length of the drum unit was machined to a predetermined dimension. The overall length of the drum unit is determined by the distance between each end of the outer periphery of both ends of the cylindrical member (hereinafter referred to as “A side” and “B side”) and the cutting tool 21, respectively. The length of the bearing is determined. Further, the inner periphery of the bearing portion was machined to a predetermined size while the cutting tool 21 was brought into contact with the inner periphery of the bearing portion and moved in a direction parallel to the rotation axis of the drum unit. At this time, when the machining tool is moved away from the rotating shaft of the drum unit, the inner diameter becomes larger, and when the processing tool is moved closer to the rotating shaft, the inner diameter becomes smaller. The positions of the processing tools 11a and 11b of the processing apparatus were adjusted while measuring with a plug gauge so that the inner diameter of the bearing portion was 20.00 mm (tolerance within −0 / + 30 μm). The length of the bearing portion protruding from the flange portion is 20 mm on both sides of the AB, and the drum unit overall length is 380.0 mm (tolerance is within 0 / + 0.1 m) while measuring with a caliper, the machining tools 11a and 11b of the machining apparatus. The position of was adjusted.

  When a straight line was drawn from the center of the outer periphery of the cylindrical member and a straight line was drawn from the center of the outer periphery of the cylindrical member toward the center of the support roller, the angle between the normal and the straight line was 45 degrees. As a result of measuring the accuracy of the manufactured drum unit with a roundness meter in the same manner as before processing, the inner diameter of the bearing portion after machining the end engaging member was 20.008 mm, and the length of the bearing portion protruding from the flange portion of the bearing portion The A side was 20.05 mm, and the B side was 20.95 mm. Furthermore, the drum unit has a total length of 380.0 mm. Further, the inner circularity of the bearing portion was 7 μm on the A side, 8 μm on the B side, the accuracy of the cylindricity of the inner diameter of the bearing portion was 5 μm, and the coaxiality between the inner periphery of the bearing portion and the outer periphery of the cylindrical member was 5 μm.

  The manufactured drum unit is fixed with a penetrating shaft that fits right and left inner diameters of the left and right bearings, and a laser run-out measuring machine (a laser measuring machine that measures the distance between a reference gauge with a straightness of 3 μm or less and the outer circumference of a cylindrical member with a resolution of 1 μm. (Shinko Co., Ltd.) measured the displacement of the surface of the drum unit 10 points in the drum unit bus direction and 10 points in the circumferential direction, and calculated the deflection accuracy by data processing.

Ten drum units were prepared by the above steps, and the outer peripheral surface runout accuracy of the 300 mm portion excluding the 20 mm portion from both ends of the cylindrical member was measured. The maximum value is shown in Table 1.
[Evaluation Example 1]
The drum unit of the present invention thus produced was mounted on a tandem color copying machine (product name: Color Laser Copier 5000 manufactured by Canon Inc.), and color misregistration and halftone image unevenness were output and image evaluation was performed. . The results are shown in Table 1.

The halftone image is one in which one effective line and two white lines are alternately continued, and one scanned in the vertical direction and the horizontal direction was used. The evaluation criteria are as follows. The evaluation results are shown in Table 1.
(Color shift)
A: Good.
○: Image unevenness but good level as a product.
X: Not good. Cannot be used as a product (uneven image)
A: Good.
○: Image unevenness but good level as a product.
X: Not good. Cannot be used as a product

Regarding the cylindrical swing accuracy of the drum unit, it was determined that 30 μm or less was particularly good, 30 μm or more and 50 μm or less was good as a product, and if it was larger than 50 μm, it was not good. With regard to the accuracy of the inner diameter of the bearing, it was judged that it was good when it was −0 or more and +30 μm or less, but it was not good when it was smaller than −0 μm or larger than 30 μm.
[Examples 2 to 5]
A cylindrical member coated with a photosensitive layer as in Example 1 and an end engaging member similar to that in Example 1 were prepared and joined in the same manner as in Example 1. The end roundness and cylindricity are adjusted as shown in Table 1. The bearing portion was processed in the same manner as in Example 1. Evaluation was performed in the same manner as in Evaluation Example 1 of Example 1. The results are shown in Table 1.
[Comparative Examples 1-2]
A cylindrical member coated with a photosensitive layer as in Example 1 and an end engaging member similar to that in Example 1 were prepared and joined in the same manner as in Example 1. The end roundness and cylindricity are adjusted as shown in Table 1. The bearing portion was processed in the same manner as in Example 1. Evaluation was performed in the same manner as in Evaluation Example 1 of Example 1, and the results are shown in Table 1.
[Comparative Example 3]
Similarly to Example 1, a cylindrical member coated with a photosensitive layer and an end engaging member were prepared. Before the assembly of the end engaging member into the cylindrical member, it was cut to the following accuracy and then joined in the same manner as in Example 1. The bearing portion of the end engaging member has an inner diameter of 20.090 mm. As a result of image evaluation by the method of Evaluation Example 1, the shakiness of the shaft portion was large and color misregistration occurred and a good image could not be obtained.
The length of the bearing part protruding from the flange part is 30.05mm.
(The dimensional accuracy was good, but the number of processes increased.)
Roundness 30μm
Runout accuracy 30μm
Coaxiality of bearing and flange outer circumference 30μm
(Inner diameter accuracy is not better than Example 1, and the number of processes is increased.)
Evaluation was performed in the same manner as in Evaluation Example 1 of Example 1, and the results are shown in Table 1.
[Example 6]
A cylindrical member coated with a photosensitive layer was prepared in the same manner as in Example 1. An end engaging member manufactured by a molding process (made of polycarbonate) having the following accuracy and dimensions was prepared, mounted on a cylindrical member in the same manner as in Example 1, and fixed with an adhesive. The shape of the end engaging member and the processing steps are shown in FIGS. (The measurement method was also the same as in Example 1)
End engaging member flange accuracy:
Outer diameter 58.4 ± 0.2mm
Thickness 16mm
Outer roundness within 60 μm Outer circumference runout accuracy within 60 μm Bearing accuracy:
Inner diameter 19.4 ± 0.2mm
Inner runout accuracy within 60 μm Inner circumference coaxiality within 60 μm This drum unit is mounted on the shaft machining apparatus shown in FIGS. 1 and 2 so that the end engaging member bearing portion has an inner diameter of 20.00 mm (tolerance within −0 / + 30 μm). The hatched portion was cut as shown in FIGS. 4A and 4B. The angle between the perpendicular and the straight line was 20 degrees when a straight line was drawn from the outer periphery center of the cylindrical member and a straight line was drawn from the outer periphery center of the cylindrical member toward the support roller center. As in Example 1, as a result of measuring the accuracy of the drum unit manufactured by the roundness meter, the bearing portion inner diameter of the end engagement member was 20.007 mm, the bearing inner circumference roundness was 5 μm, the bearing inner circumference deflection accuracy was 5 μm, The coaxiality between the inner periphery of the bearing portion and the outer periphery of the cylindrical member was within 5 μm. Evaluation was performed in the same manner as in Evaluation Example 1 of Example 1. The results are shown in Table 2.

[Examples 7 to 10]
A cylindrical member coated with a photosensitive layer as in Example 1 and an end engaging member similar to that in Example 6 were prepared and joined in the same manner as in Example 1. The end roundness and cylindricity are adjusted as shown in Table 2. The bearing portion was processed in the same manner as in Example 1. Evaluation was performed in the same manner as in Evaluation Example 1 of Example 1. The results are shown in Table 2.
[Comparative Example 4]
A cylindrical member coated with a photosensitive layer as in Example 1 and an end engaging member similar to that in Example 6 were prepared and joined in the same manner as in Example 6. The end roundness and cylindricity are adjusted as shown in Table 1. The bearing portion was processed in the same manner as in Example 6. Evaluation was performed in the same manner as in Evaluation Example 1 of Example 1. The results are shown in Table 2.
[Comparative Example 5]
A cylindrical member coated with a photosensitive layer as in Example 1 and an end engaging member similar to that in Example 6 were prepared. Before the assembly of the bearing portion of the end engaging member to the cylindrical member, it was cut to the following accuracy, and then joined in the same manner as in Example 1. The bearing portion of the end engaging member has an inner diameter of 20.095 mm. As a result of image evaluation by the method of Evaluation Example 1, the shakiness of the shaft portion was large and color misregistration occurred and a good image could not be obtained.
Bearing part inner circumference roundness 30μm
Bearing section inner runout accuracy 30μm
(Inner diameter accuracy is not better than Example 1, and the number of processes is increased.)
Evaluation was performed in the same manner as in Evaluation Example 1 of Example 1, and the results are shown in Table 2.
[Example 11]
A cylindrical member coated with a photosensitive layer was prepared in the same manner as in Example 1. An end engaging member manufactured by a molding process (made of polycarbonate) having the following accuracy and dimensions was prepared, mounted on a cylindrical member in the same manner as in Example 1, and fixed with an adhesive. The shape of the end engaging member and the processing steps are shown in FIGS.
Engagement member accuracy:
Flange part outer diameter 58.4 ± 0.2mm
Flange thickness 18mm
Flange outer circumference roundness within 70 μm Flange outer circumference runout accuracy within 70 μm The shaft used was an end engaging member flange that was press-fitted with an aluminum alloy: JIS6063 into the shaft. The dimensions are as shown below.
Shaft outer diameter 30.6 ± 0.2mm
Shaft outer circumference runout accuracy within 70μm Length of shaft protruding from flange is 21 ± 0.5mm
The outer peripheral concentricity is within 80 μm. This drum unit is attached to the shaft machining apparatus shown in FIGS. 1 and 2, and the cutting tool is set so that the end portion engaging member shaft portion has the following specifications, as shown in FIGS. The shaded area was processed.
Outer diameter 20.00mm (tolerance within 0 / + 30μm)
When a straight line is drawn from the center of the cylindrical member outer periphery and a straight line is drawn from the cylindrical member outer periphery center toward the support roller center, the angle between the perpendicular and the straight line is 70 degrees on both the left and right sides.

As in Example 1, as a result of measuring the produced drum unit with a roundness meter,
Shaft outer diameter of end engagement member 30.15mm
Overhang length 20.1mm from flange
Shaft outer circumference roundness 7μm
Shaft outer circumference runout accuracy 7μm
The coaxiality between the outer periphery of the shaft portion and the outer periphery of the cylindrical member was 7 μm.

  The manufactured drum unit was fixed with a bearing so that the left and right shaft portions fit tightly, and image output evaluation was performed in the same manner as in Evaluation Example 1 with a laser shake measuring machine similar to that in Example 1. The results are shown in Table 3.

[Examples 12 to 15]
A cylindrical member coated with a photosensitive layer as in Example 1 and an end engaging member similar to Example 11 were prepared and joined in the same manner as in Example 11. The end roundness and cylindricity are adjusted as shown in Table 3. The bearing portion was processed in the same manner as in Example 11. Evaluation was performed in the same manner as in Evaluation Example 1 of Example 1. The results are shown in Table 3.
[Comparative Example 6]
A cylindrical member coated with a photosensitive layer as in Example 1 and an end engaging member similar to Example 11 were prepared and joined in the same manner as in Example 11. The end roundness and cylindricity are adjusted as shown in Table 3. The bearing portion was processed in the same manner as in Example 11. Evaluation was performed in the same manner as in Evaluation Example 1 of Example 1. The results are shown in Table 3.
[Comparative Example 7]
As in Example 1, a cylindrical member coated with a photosensitive layer and an end engaging member similar to Example 11 were prepared. After the bearing portion of the end engaging member was cut to the following accuracy before being assembled to the cylindrical member, it was joined in the same manner as in Example 11. The bearing portion of the end engaging member has an inner diameter of 30.090 mm. As a result of image evaluation by the method of Evaluation Example 1, the shakiness of the shaft portion was large and color misregistration occurred and a good image was not obtained.
Shaft outer circumference roundness 25μm
Shaft outer circumference runout accuracy 25μm
(Inner diameter accuracy is not better than Example 1, and the number of processes is increased.)
Evaluation was performed in the same manner as in Evaluation Example 1 of Example 1. The results are shown in Table 3.
[Examples 16 to 22]
A cylindrical member coated with a photosensitive layer as in Example 1 and an end engaging member as in Example 1 were prepared and joined in the same manner as in Example 1. With respect to the position at which the processing tool is applied to the shaft portions 10a and 10b, the angle between the straight lines connecting the contact positions of the two sets of support rollers 3 and 4 at positions lower than the cylindrical member outer peripheral reference central axis 8 is divided into two equal parts. The bearing portion was processed in the same manner as in Example 1 so as to contact the circumference of the bearing member in the direction shown in Table 4 with respect to the straight line 15. The bearing unit diameter accuracy of the processed drum unit was evaluated. The results are shown in Table 4.

[Comparative Examples 8-9]
A cylindrical member coated with a photosensitive layer as in Example 1 and an end engaging member as in Example 1 were prepared and joined in the same manner as in Example 1. With respect to the position at which the processing tool is applied to the shaft portions 10a and 10b, the angle between the straight lines connecting the contact positions of the two sets of support rollers 3 and 4 at positions lower than the cylindrical member outer peripheral reference central axis 8 is divided into two equal parts. The bearing portion was processed in the same manner as in Example 1 so as to contact the circumference of the bearing member in the direction shown in Table 4 with respect to the straight line 15. The bearing unit diameter accuracy of the processed drum unit was evaluated. The results are shown in Table 1.

It is a front schematic diagram which shows the processing apparatus of the electrophotographic photosensitive drum unit of this invention. It is a side surface schematic diagram which shows the processing apparatus of the electrophotographic photosensitive drum unit of this invention. An end engaging member having a shaft portion used in the electrophotographic photosensitive drum unit of the present invention, A is a side view, B is a plan view, and C is a plan view showing a positional relationship with a cutting blade. An end engaging member having a bearing portion used in the electrophotographic photosensitive drum unit of the present invention, A is a side view, B is a plan view, and C is a plan view showing a positional relationship with a cutting blade. In the end engaging member having a convex bearing portion used in the electrophotographic photosensitive drum unit of the present invention, A is a side view, B is a plan view, and C is a plan view showing a positional relationship with a cutting blade.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Cylindrical member 2 Outer peripheral surface 2a, 2b of cylindrical member Outer peripheral surface support roller of cylindrical member and contact part 3a, 3b, 4a, 4b Support roller 3c, 4c, 5c Roller shaft 5a, 5b Drive roller 6 Drum unit 7a Motor 7b Driving force transmission gear
7c Driving force receiving gear 8 Peripheral reference center shafts 9a, 9b End engaging members 10a, 10b Shaft portions 11a, 11b of end engaging members Processing tools 12a, 12b Tool bases 13a, 13b Rails 14a, 14b Touching the drum unit side surface Shake prevention roller 15 Vertical line 16a drawn from the cylindrical member outer periphery center Straight line 16b drawn from the cylindrical member outer periphery center toward the support roller center Straight line 17 drawn from the cylindrical member outer periphery center toward the support roller center A cutting tool is applied to the shaft portion. Direction 18 Shaft shape after machining 19 Shaft shape before machining 20 Cutting tool blade 21 Bearing shape before machining 22 Bearing shape after machining 23 Bearing shape before machining 24 Bearing shape after machining θ 15 Angle between 2a and 16a, 16b 2θ Angle between 16a, 16b

Claims (12)

In the method for manufacturing an electrophotographic photosensitive drum unit, which includes at least a step of assembling an end engaging member having a shaft or a bearing portion to an end of a cylindrical member having a photosensitive layer, the end engaging member is attached to the cylindrical member. A method of manufacturing an electrophotographic photosensitive drum unit comprising performing a processing step of processing a shaft or a bearing portion of the end engaging member after the step of assembling to the end. In the processing step, the shaft of the end engaging member or the bearing portion is the same as the center axis of the cylindrical member outer periphery reference in a state where the electrophotographic photosensitive drum unit is rotated around the center axis of the cylindrical member outer periphery reference. 2. The method of manufacturing an electrophotographic photosensitive drum unit according to claim 1, wherein the method is a step of processing into a similar circle having a central axis. The method of manufacturing an electrophotographic photosensitive drum unit according to claim 1, wherein the processing step is performed by cutting or grinding. In the processing step, a plurality of rollers are arranged so as to contact the outer peripheral surface of the cylindrical member to support the cylindrical member, and at least one of the plurality of rollers is driven to rotate the cylindrical member 4. The method for producing an electrophotographic photosensitive drum unit according to claim 2, wherein the process is a step of performing the above-described processing. When the roller group that shares the rotation axis among the plurality of rollers and supports both ends on the same bus bar of the cylindrical member is one set, in the processing step, three or more roller groups abut on the cylindrical member, Of these, two sets of roller groups are in contact with different generatrixes on the outer peripheral surface of the cylindrical member at a position lower than the cylindrical member outer peripheral reference central axis to support the cylindrical members substantially horizontally, and one set of roller groups is the cylindrical group. 5. The electrophotographic photosensitive drum unit according to claim 4, wherein the electrophotographic photosensitive drum unit is rotated by abutting at a position higher than the member outer peripheral reference central axis and driving one or more rollers therein. Production method. In the processing step, the processing position of the shaft of the end engaging member or the bearing portion contacts the cylindrical member outer peripheral reference central axis of the electrophotographic photosensitive drum unit and a different bus bar to support the cylindrical member substantially horizontally. It is a direction of 45 degrees or more and 135 degrees or less with respect to a straight line that bisects an angle between two sets of roller groups that are sandwiched by straight lines connecting positions where the roller contacts one end of the cylindrical member. 6. A method for producing an electrophotographic photosensitive drum unit according to claim 5. A roller is applied to one end of the cylindrical member of two sets of rollers having a cylindrical member outer peripheral reference central axis of the electrophotographic photosensitive drum unit as a central point and abutting on different buses to support the cylindrical member substantially horizontally. The angle obtained by dividing the angle between the straight lines connecting the contact positions into two equal parts is θ (degrees), and the roundness of the end part before one of the outer peripheral ends of the cylindrical member contacting the roller is A (Μm), manufacture of an electrophotographic photosensitive drum unit in which the roundness of the end portion before the other processing step is B (μm) and the cylindricity of the cylindrical member before the processing step is C (μm) 7. The method for producing an electrophotographic photosensitive drum unit according to claim 5, wherein the following formula is satisfied.
0 ≦ (Asinθ + Bsinθ + C) ≦ 50 μm The electrophotographic photosensitive member according to any one of claims 2 to 7, wherein in the processing step, the shaft or the bearing portion of the end engaging member is processed simultaneously from the ends on both sides of the cylindrical member. Drum unit manufacturing method. An electrophotographic photosensitive drum unit manufactured by the method according to claim 1. The cylindrical swing accuracy of the electrophotographic photosensitive drum unit based on the end engaging member axis or the bearing center axis after being processed into a similar circular shape having the same center axis as the center axis of the cylindrical member outer circumference reference is 50 μm. The electrophotographic photosensitive drum unit manufactured by the method according to any one of claims 4 to 8, wherein: The image forming apparatus having an electrophotographic photosensitive drum unit, a charging unit, an exposing unit, a developing unit, and a transferring unit, wherein the electrophotographic photosensitive drum unit is the electrophotographic photosensitive drum unit according to claim 1. An image forming apparatus comprising: An apparatus for processing an electrophotographic photosensitive drum unit, wherein a plurality of rollers are provided so that a cylindrical member having a photosensitive layer is assembled with an end engaging member having a shaft or a bearing so as to abut on the outer peripheral surface of the cylindrical member. Supporting means for arranging and supporting, rotating means for driving at least one of the plurality of rollers to rotate the cylindrical member, shaft or bearing part of the end engaging member assembled to the cylindrical member An apparatus for processing an electrophotographic photosensitive drum unit having processing means for processing the above.