JP3192511B2 - Method for manufacturing substrate for photoreceptor drum - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of manufacturing a substrate for a photosensitive drum, and more particularly to a method of manufacturing a substrate for a photosensitive drum for obtaining a photosensitive drum applied to various image forming apparatuses. .

[0002]

2. Description of the Related Art In an electrophotographic process used for an image forming apparatus such as an electrophotographic copying machine, a laser printer, and a facsimile, a uniform electrostatic charge is applied to a photosensitive drum, and then the photosensitive drum is exposed to an image. An electrostatic latent image is formed on the surface of the drum, and the electrostatic latent image is developed to form a toner image. This toner image is transferred onto a transfer sheet and then fixed to form a visible image.

In one example of a photosensitive drum applied to the above-described electrophotographic process, a photosensitive layer is formed on a surface of a cylindrical photosensitive drum base made of an aluminum alloy or the like.

However, the surface of the photosensitive drum on which an electrostatic latent image or a toner image is formed is required to be smooth,
Therefore, the substrate for the photosensitive drum is subjected to surface finishing by a cutting tool or the like. In addition, from the viewpoint of adhesion to the photoconductor layer, the surface state of the substrate for the photoconductor drum may be processed so as to be coarser than the mirror surface state and to the extent that minute irregularities are present. Is 0.2-1
A uniformly finished surface is required in the range of μm.

Recently, as a suitable means for making the surface of the photosensitive drum substrate smooth, a finishing process using a diamond tool has been performed. As such a diamond tool, a single crystal diamond chip such as a natural diamond is used. Things are used.

[0006] However, a diamond bite using a single crystal diamond tip is extremely expensive. In addition, since the cutting edge of the single crystal diamond tip is sharp and the sharpness is too good, when processing the surface of the photosensitive drum substrate using these single crystal diamond tools, a surface roughness of about 1 μm will be obtained. In this case, there is a problem that the cutting edge shape is regularly transferred to the base material along with the feed pitch, so that the pitch of the unevenness becomes coarse and the adhesion of the photoconductor layer is reduced.

Incidentally, in order to obtain the surface condition (surface roughness of about 0.2 to 1 μm) required for the photosensitive drum substrate, a cutting tool made of a polycrystalline diamond chip can be used. A cutting tool made of diamond tips is advantageous because of its low cost. However, a polycrystalline diamond chip composed of a large number of diamond crystals has large irregularities on the cutting edge from the beginning due to steps at the crystal interface and falling off of the crystals. In the case of processing, the surface roughness of the obtained photosensitive drum base varies greatly from tool to tool, and it is difficult to obtain a stable surface state.

On the other hand, as a method of treating the cutting edge ridge to obtain a good surface condition, a method of polishing the flank of the diamond chip to a state without polishing marks, and then polishing the rake face to finish the cutting edge. It has been proposed (see Japanese Patent Publication No. 3-75282). However, this processing method is effective for a single crystal diamond chip capable of forming a sharp cutting edge by polishing, but has large irregularities on the cutting edge due to a step at a crystal interface and the like as in a polycrystalline diamond chip. Regarding diamond chips, even if this processing method is applied, large irregularities on the cutting edge cannot be removed, and as a result, a substrate for a photosensitive drum having a good surface state cannot be obtained.

By the way, in order to solve the above-mentioned problem, a so-called "break-in process" is performed in which the cutting edge of the manufactured (polished) diamond tip is worn to some extent by cutting a dummy material. It has been known. By performing this break-in processing, the unevenness existing on the cutting edge ridge is reduced, and a defect or the like generated at the time of polishing is also removed to obtain a high-quality cutting edge ridge. Therefore, if the base material is finished after the break-in process, good cutting is performed, and an excellent surface state is formed on the obtained photosensitive drum base.

[0010]

However, the cutting distance required for the break-in processing is less than 50 to 200 km (corresponding to 60 to 200 photosensitive drums), and the time required for the break-in processing and the time required for the break-in processing are reduced. Dummy material, setup work, etc. are enormous and cause a decrease in productivity. In addition, the life of the cutting tool itself is shortened.

The present invention has been made in view of the above circumstances, and an object of the present invention is to make it possible to immediately perform surface finishing of a base material without performing break-in processing of a polycrystalline diamond tool. Another object of the present invention is to provide a method for manufacturing a substrate for a photoreceptor drum, which can produce a substrate for a photoreceptor drum having a stable surface state (uniform surface roughness) with high production efficiency.

[0012]

In order to achieve the above object, a method of manufacturing a substrate for a photoreceptor drum according to the present invention is to feed and move a diamond bit holding a diamond chip while abutting a substrate material. Thus, in the method for manufacturing a photosensitive drum substrate for performing a surface finishing process on the substrate material, the diamond chip includes a main cutting edge formed by intersecting a rake face and a lateral flank, and a rake face and a front flank. Consisting of polycrystalline diamond having a sub-cutting edge formed by intersecting, the front flank of the diamond tip is formed with a polished surface without polishing marks, and
The sub-cutting edge is characterized in that a finely polished portion with a minute width formed by a linear surface is formed .

[0013]

[Action]

(1) Since an inexpensive cutting tool made of polycrystalline diamond chips is used, the manufacturing cost of the photosensitive drum base can be reduced. (2) Since the front flank of the diamond tip is formed of a polished surface without polishing marks, minute waviness of the cutting edge is corrected. (3) Since the sub-cutting edge of the diamond tip is formed with a finely polished portion having a very small width, large unevenness existing on the cutting edge due to a step at a crystal interface or the like is removed, and a smooth cutting edge is obtained. Is newly formed. (4) Although the diamond tip used in the present invention is made of polycrystalline diamond, a high-quality cutting edge is formed from the beginning. Therefore, if a cutting tool having such a diamond tip is used, the surface finish processing of the base material can be immediately performed without performing the break-in processing, and the productivity can be improved. In addition, the manufactured photoreceptor drum substrate has a uniform surface roughness because the large unevenness transferred to the surface does not exist on the cutting edge ridge.

[0014]

EXAMPLES Examples of the present invention will be described below, but the present invention is not limited to these examples.

<Substrate Material> An example of manufacturing a substrate for a photosensitive drum made of aluminum is as follows.
mm aluminum tube is formed by a drawing method or an extrusion method, and this is cut at, for example, every 300 mm, and both end faces are finished with an end face to obtain a base material.

<Cutting Device> FIG. 1 is an explanatory view showing a cutting device used in the present invention. This cutting equipment
A headstock 82 and a tailstock 83 are fixed to both ends of the upper surface of the bed 81, and a chuck jig 85 is fixed to a spindle 84 extending from the headstock 82. A belt 86 is wound around the main shaft 84 via a pulley, and is rotated by a motor (not shown).

On the other hand, a tailstock shaft 87 extends from the tailstock 83 and a chuck jig 88 is fixed to the end thereof. A saddle 89 is mounted on the bed 81 between the headstock 82 and the tailstock 83 such that the saddle 89 can reciprocate in the direction of arrow A.
A tool rest 90 is attached so as to be movable in the direction. Cutting tools 91 and 94 are detachably mounted on the front surface of the tool post 90, and a knob 92 for adjusting the cutting amount is provided on the rear surface.

In the case of processing the surface of the photosensitive drum base, a chuck jig 85 is lightly applied to the opening at one end of the base material 93 with the tailstock shaft 87 retracted, and the other end is opened. After hitting one chuck jig 88, the tailstock shaft 87 is lightly pushed out to lightly push both chuck jigs from both ends of the base material 93.

The base material 93 thus fixed to the apparatus is rotated via a belt 86, while a saddle 89 is attached to a tool post 90 at a desired height from the left end in the drawing, and a roughing cutting tool 94 is attached to the base. The material 93 is cut in a fixed amount, and is moved rightward at a constant feed speed. When the entire length of the base material 93 is exceeded, the saddle 89 is stopped, the roughing tool 94 is returned, and then the finishing tool 91
Is moved slowly leftward at a constant feed speed while contacting the surface of the base material 93, and returns to the original left position. By this reciprocating motion, the surface of the base material 93 is finished by the finishing bit 91 (diamond bit).

<Diamond Tool> FIG. 2A is a plan view showing a diamond tool used as the finishing tool 91 in the above-mentioned cutting apparatus, and FIG. 2B is a side view thereof. In FIG. 2, reference numeral 1 denotes a chip made of polycrystalline diamond. The chip 1 is joined to an insert 2 made of a cemented carbide or the like, and the insert 2 is fixedly held at the tip of a shank 3. In this insert 1, the rake face 8 and the lateral flank face 4 intersect to form the main cutting edge 5
Are formed, and the rake face 8 and the front flank face 7 intersect to form the sub cutting edge 6.

As shown in FIG. 2A, the main cutting edge 5 has a required cutting angle κ ₁ with respect to the base material W,
The sub cutting edge 6 has a slight inclination angle κ ₂ with respect to the surface of the base material W. On the other hand, as shown in FIG. 2B, a required clearance angle γ is formed on the front clearance surface 7. Instead of the method of joining the chip 1 by the insert 2 described above, a holding member may be attached to the shank 3 and the chip may be detachably attached to the shank via the holding member.

<Diamond chip> The diamond chip constituting the diamond cutting tool has a front flank formed of a polished surface without polishing marks, and a fine polished portion having a fine polished portion with a small width. It is formed on the cutting blade.

FIG. 3A is a plan view showing a tip portion (a portion near the cutting edge) of the above-mentioned tip 1, and FIG. 3B is a side sectional view (IV-IV sectional view) thereof. . In addition,
The broken line portion shown in the figure shows the cutting edge shape before the fine polishing processing. The front flank 7 and the rake face 8 of the chip 1 are each polished, and in particular, the front flank 7
Is polished so that no polishing marks remain. As a method of polishing these surfaces, first, the rake face 8 is polished in advance, and then the front flank face 7 is polished while holding the shank so that no polishing marks remain. As a method of polishing so that polishing marks do not remain, for example, a grinding wheel may be pressed against the front flank, and grinding may be performed while feeding in a direction different from the polishing direction. The degree of unevenness of the polished front flank 7 is preferably 0.6 μm or less in a range from the ridgeline of the sub-cutting edge to about 0.1 mm below. In this state, the front flank 7 is polished so that no polishing marks remain (the cutting edge shape at this stage is indicated by a broken line, and b represents the tip level of the sub cutting edge).
In this case, minute waviness of the sub cutting edge 6 formed by the front flank 7 and the rake face 8 is considerably suppressed.

However, the microscopic state at the cutting edge of the sub cutting edge is still unstable only by the above-mentioned polishing. That is, FIG. 4 is an enlarged view of the cutting edge of the sub cutting edge.
As shown in FIG. 7, due to the crystal structure of the polycrystalline diamond constituting the chip 1, the cutting edge has large irregularities due to a step at the crystal interface of each diamond crystal 9 and the like.

Therefore, in the present invention, a diamond chip having a finely polished portion with a very small width formed on the sub cutting edge is used. That is, in manufacturing the chip 1, after the rake face 8 and the front flank 7 are polished, the fine polished portion 10 is formed by a fine lapping process in which a grinding wheel is brought into contact with the sub cutting edge 6. Here, the surface roughness of the finely polished portion 10 is preferably 0.6 μm or less.

As a result of this fine polishing process, the sub-cutting edge 6 of the chip 1 removes large irregularities of each diamond crystal 9 entering and exiting as shown by oblique lines in FIG. A smooth cutting edge 11 having no irregularities is newly formed at the boundary part a of FIG. Here, it is preferable that the degree of the unevenness of the cutting edge 11 is approximately a half of the surface roughness required for the photosensitive drum base to be manufactured, for example, 0.2 to 1 μm. In order to obtain the surface roughness, it is preferable to set the unevenness of the cutting edge 11 in the range of 0.1 to 0.6 μm.

The minor cutting edge 11 formed by the front flank 7 having no polishing marks and the finely polished portion 10 is made of polycrystalline diamond, but is entirely smooth and has a cutting edge. On the ridge 11, fine irregularities of, for example, about 0.1 to 0.6 μm, which are boundaries of many diamond crystals, remain. Therefore, when the photoreceptor drum base is processed with a diamond bit having such a tip, the surface roughness (for example, the surface roughness is about 0.2 to 1 μm) close to the mirror surface but not to the mirror surface is uniform. Obtained and a stable finished surface is formed. Since such a good finishing process is performed from the beginning of the production of the diamond cutting tool (polishing of the diamond chip), the conventional break-in process or the like is completely unnecessary.

Here, the width t of the finely polished portion 10 is large enough to remove a large unevenness due to a step at the crystal interface or the like, and does not adversely affect the life of the cutting tool itself. It needs to be large. More specifically, when using a polycrystalline diamond chip having a size not less than 20 μm and not less than twice the average particle size of the diamond crystal, for example, having an average particle size of about 0.5 μm, the fine polished portion 10 Is set in the range of 1 to 20 μm, preferably in the range of 5 to 10 μm. If the width t of the finely polished portion 10 is too small, large irregularities due to a step at the crystal interface of the diamond crystal and the like still remain, and even if the finishing process is performed with such a cutting tool, the obtained photoconductor is obtained. The variation in the surface roughness of the drum substrate cannot be prevented. On the other hand, when the width t exceeds 20 μm, it is effective from the viewpoint of removing the large irregularities, but is not preferable because the life of the cutting tool itself tends to be shortened.

On the other hand, the length for performing the fine polishing is set in consideration of the length of the sub-cutting edge 6 of the tip 1 and cutting conditions.
For example, if the feed rate is about 0.1 mm / rev,
The length L of the finely polished portion 10 is preferably set to about 1500 μm.

The width t and length L of the finely polished portion 10
Is extremely small, and therefore, in a polishing process in which a grinding wheel is brought into contact with the sub cutting edge 6 of the chip 1 for a short time, the fine polishing portion 1
0 is not an accurate linear surface, but actually has a shape in which a linear surface 12 and a curved surface 13 are combined as shown in FIG. That is, the finely polished portion 10 here includes not only a portion formed by a straight surface but also a shape formed by combining a straight surface and a curved surface.

<Example> A substrate for a photosensitive drum was manufactured by performing a surface finishing process on a substrate material according to the method of the present invention. The base material, diamond bite and cutting conditions are as follows. (1) Base material Base material for an electrophotographic photosensitive drum (diameter 80 mm, total length 355 mm, plate thickness 1.2 mm, material: aluminum alloy AL5000 series) (2) Diamond bite Polycrystalline diamond shown in FIG. 2 (FIG. 3) Diamond bite A using a tip [Average particle diameter of diamond crystal is about 0.5 μm, clearance angle γ is 11 °, fine polished part 1
0, the width t is 5 μm, the length L is 1500 μm, the angle β between the finely polished portion 10 and the rake face 8 is 45 °, the cutting edge 1
The unevenness of No. 1 was set in the range of 0.1 to 0.6 μm. The size of the unevenness of the cutting edge 11 is determined by an optical microscope “PM10
M-L2M "(manufactured by Olympus Corporation). (3) Cutting Conditions A cutting tool A was set as a finishing cutting tool 91 of the cutting apparatus shown in FIG. 1 to perform surface finishing. The inclination angle κ ₂ of the sub cutting edge 6 is set to 1 to 3 °, and the rotation speed is set to 3
000 rpm, the feed rate was set to 0.1 mm / rev, and the cutting depth was set to 0.01 mm. Finishing was continuously performed with the same cutting tool A until the processing distance became 500 km.

<Comparative Example> A substrate for a photosensitive drum was manufactured by performing a surface finishing process on a substrate material using a conventional diamond bit instead of the bite A used in the example. The base material, diamond bite and cutting conditions are as follows. (1) Base material Same base material for electrophotographic photosensitive drum as used in the examples (2) Diamond tool Diamond tool B made of polycrystalline diamond chip
~ D (the average particle size of the diamond crystal is about 0.5 μm,
Grinding the front flank and rake face of a diamond tip to form a cutting edge, and without a finely polished part. (3) Cutting Conditions Using diamond cutting tools B to D, finishing was continuously performed under the same conditions as in the example until the processing distance became 500 km.

<Experimental Example> The photosensitive drum bases manufactured in the above Examples and Comparative Examples were sampled at a constant processing distance, and an electrophotographic photosensitive drum was manufactured using these photosensitive drum bases. Then, each of the produced electrophotographic photosensitive drums is transferred to an electrophotographic copying machine “UBix-
3045 "(manufactured by Konica Corporation) to evaluate the variation of the toner supply control reference voltage with respect to the cutting distance. The results of these evaluations are shown in FIGS.

Incidentally, these electrophotographic photosensitive drums are
The sample was prepared by laminating an undercoat layer, a carrier generation layer, and a carrier transport layer shown below on the surface of each sampled photosensitive drum substrate. (1) Subbing layer A coating solution comprising an ethylene copolymer "ELVAX 4260" (binder), toluene (solvent), and methyl ethyl ketone (solvent) is applied to the surface of the substrate for a photosensitive drum and dried. As a result, an undercoat layer having a thickness of 0.2 μm was formed. (2) Carrier generation layer τ-type metal-free phthalocyanine (carrier generation substance) and silicone resin “KR-5240” (binder solution)
And methyl ethyl ketone (solvent)
By coating on the undercoat layer and drying, the amount of adhesion is 4
A carrier generation layer of mg / dm ² was formed. (3) Carrier transport layer “ED-485” (styryltriphenylamine carrier transport) and pentaerythryl-tetrakis [3-
(3,5-di-tert-butyl-4-hydroxyphenyl) propionate] "Irganox-1010"
(Antioxidant) and silicone oil "KF-54 (1
/ 10 diluted solution) ", a coating solution composed of polycarbonate BPZ" Iupilon Z-200 "(binder), and 1,2-dichloroethane (solvent) on the carrier generating layer, and dried. A carrier transport layer having a thickness of 20 μm was formed.

FIGS. 6 and 7 are graphs showing the detected values of the toner supply control reference voltage for adjusting the image density for the electrophotographic photosensitive drums having different cutting distances, respectively. 7A shows the detection values on the photosensitive drum, and FIG. 7 shows comparative examples (bytes B to D).
Shows the detected values on the photosensitive drum.

As shown in FIG. 6, when the electrophotographic photosensitive drum using the drum substrate manufactured in the embodiment is mounted, the adjusted reference voltage is stable from the beginning of processing. This is understood to be because the surface roughness of the drum substrate is stable from the beginning of processing. On the other hand, as shown in FIG. 7, when the electrophotographic photosensitive drum having the drum base manufactured in the comparative example is mounted, the fluctuation of the adjusted reference voltage and the variation for each byte are recognized. 200 until the reference voltage becomes stable.
A processing distance of about km is required. It is understood that this is because the surface roughness of the drum base varies and varies.

[0037]

According to the present invention, since the surface is finished using a diamond tool having a high-quality cutting edge formed from the beginning of manufacture, the surface of the base material can be immediately formed without performing the break-in processing of the diamond tool. Finishing can be performed, and the substrate for the photosensitive drum can be stably manufactured with high production efficiency. Further, the photoreceptor drum substrate manufactured according to the present invention has a stable surface state (uniform surface roughness), so that the image density can be adjusted in an image recording apparatus equipped with the photoreceptor. An electrophotographic image with excellent and excellent image quality can be formed.

[Brief description of the drawings]

FIG. 1 is an explanatory view showing a cutting apparatus used in the present invention.

FIG. 2A is a plan view showing a diamond tool used as a finishing tool of a cutting device;
(B) is a side view thereof.

FIG. 3A is a plan view showing a tip portion of a diamond tip, and FIG. 3B is a side sectional view thereof.

FIG. 4 is an explanatory view schematically showing a crystal structure of a cutting edge of a diamond tip.

FIG. 5 is an enlarged side sectional view showing a finely polished portion.

FIG. 6 is a graph illustrating a detection value of a toner supply control reference voltage of the electrophotographic photosensitive drum according to the embodiment.

FIG. 7 is a graph showing a detected value of a toner supply control reference voltage of an electrophotographic photosensitive drum according to a comparative example.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Insert 2 Insert 3 Shank 4 Side flank 5 Main cutting edge 6 Secondary cutting edge 7 Front flank 8 Rake face 9 Diamond crystal 10 Finely polished part 11 Cutting edge ridge

──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Toyoji Ito 2970 Ishikawacho, Hachioji-shi, Tokyo Konica Corporation (72) Inventor Takami Hashimoto 2970 Ishikawacho, Hachioji-shi, Tokyo Konica Corporation (56 References JP-A-2-110570 (JP, A) JP-A-4-242745 (JP, A) JP-A-4-87705 (JP, A) JP-A-4-242742 (JP, A) Field surveyed (Int. Cl. ⁷ , DB name) G03G 5/00-5/16

Claims (2)

(57) [Claims] 1. A method of manufacturing a substrate for a photoreceptor drum, in which a diamond cutting tool holding a diamond chip is fed and moved while being in contact with a substrate material, thereby performing a surface finishing process on the substrate material. A main cutting edge formed by intersecting a rake face and a lateral flank, and a polycrystalline diamond having a sub-cutting edge formed by intersecting a rake face and a front flank, wherein the front flank of the diamond chip is Formed on a polished surface without polishing marks and straight on the secondary cutting edge
A finely polished portion having a very small width formed on the surface of the photosensitive drum. 2. The fine width of the finely polished portion formed on the sub-cutting edge is set to be at least twice the average grain size of the diamond crystal forming the diamond chip and within the range of 1 to 20 μm. The method for producing a substrate for a photosensitive drum according to claim 1, wherein