JP2944482B2 - Method for manufacturing drawn tube for photosensitive drum substrate - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a photosensitive drum
The present invention relates to a method for producing a drawn tube having excellent surface smoothness used as a body .

[0002] In this specification, the term aluminum includes aluminum and its alloys.

[0003]

2. Description of the Related Art In an OPC photosensitive drum of an electrophotographic apparatus such as a copying machine, a printer, a facsimile, etc., an aluminum tube is used as a base and a charge generation layer (CGL) is formed on an outer peripheral surface thereof.
A method of providing a laminated photosensitive layer comprising a charge transport layer (CTL) and a charge transport layer (CTL) is often used.

In order to form a photosensitive drum having high sensitivity in order to obtain high image quality, it is necessary to apply the charge generating layer (CGL) thinly and uniformly to about 0.2 to 0.5 μm. There is. Therefore, an aluminum tube having a high smoothness with few irregularities on its surface must be used as the base.

On the other hand, market demands for lowering the cost of electrophotographic apparatuses have demanded a low-cost photosensitive drum base.

In such a background, a drawn tube called a non-cut ED tube is used as a substrate for a photosensitive drum because a high surface smoothness can be obtained by a simple process without requiring surface cutting. As shown in FIG.
(2) is an extruded raw tube passed between the drawing die (11) and the drawing plug (13) by using a drawing apparatus (10) composed of a combination of a drawing die (11) and a drawing plug (13). (1)
It is manufactured by drawing. As shown in FIGS. 2 and 3 (a), (b) and (c), the outer peripheral surface of the extruded raw tube (1) is usually provided with a die mesh along the extrusion direction at the time of extrusion.
(3) is formed, but the non-cutting ED pipe (drawn pipe)
(2) is to close the dice (3) by reducing the diameter at the time of drawing, and to obtain the required surface smoothness only in this step.

[0007]

However, in the conventional non-cutting ED pipe (drawing pipe), FIGS. 2 and 3 (a) and 3 (b)
As shown in (c), the die (3) of the extruded raw tube (1) remains as a thin wrinkle-like convex or concave defect (4),
Due to this, partial CGL breakage or CG in the charge generation layer
It was difficult to form a thin and uniform photosensitive layer due to L accumulation.

[0008] The present invention solves the above-mentioned problems and provides an outer peripheral surface.
It is an object of the present invention to provide a method for manufacturing a drawn tube for a photosensitive drum substrate, which can easily obtain high surface smoothness by drawing a raw extruded tube having a die .

[0009]

According to the present invention, there is provided a photosensitive drum according to the present invention.
In order to achieve the above object, a method for manufacturing a drawn tube for a ram base includes passing an aluminum extruded raw tube (1) between a drawing die (11) and a drawing plug (13), and forming the drawn die (1).
While supplying lubricating oil between 1) and the extrusion pipe (1),
Pull out the extruded raw tube (1) and draw the photosensitive drum substrate
In the method for producing (2), the extruded raw tube (1) has an outer periphery.
A surface having a die (3), a lubricating oil having a viscosity of 200 cst or less,
The outer diameter reduction rate from (1) to the drawn pipe (2) is 30% or less, and the cross-sectional area reduction rate is 5% or more.

In the method of the present invention , the die (3)
The present invention can be applied to drawing of an extruded aluminum pipe (4) having the following formula, and the composition of the raw pipe is not particularly limited as long as it is aluminum-based. The drawn tube manufactured by the method of the present invention has high surface smoothness and is used as a substrate for a photosensitive drum .

Lubricating oil is used for the purpose of preventing abrasion of the drawing die (11), reducing the pulling force, preventing seizure, and the like. Different ones are used properly. However, when the high-viscosity lubricating oil is pushed between the drawing die (11) and the extruded raw tube (1), it tends to form oil pits and easily become concave defects. Therefore, in the present invention, a lubricating oil having a low viscosity of 200 cst or less is used in order to suppress the formation of oil pits and thus the occurrence of concave defects. Preferred lubricating oils have a viscosity of 100 cst or less. Examples of lubricating oils having a viscosity of 200 cst or less include mineral oils and fats and oils.

The outer diameter (D ₀ ) and cross-sectional area (S ₀ ) of the extruded raw pipe (1) and the outer diameter (D) and cross-sectional area (S ), The following equation (i) (i
Depending on the outer diameter reduction rate and cross-sectional area reduction rate defined in (i), there is a difference in the repair condition of the die (3) formed during extrusion of the raw tube (1).

Outer diameter reduction rate (%) = (D ₀ −D) / D ₀ × 100 (i) Cross-sectional area reduction rate (%) = (S ₀ −S) / S ₀ × 100 (ii) If the outer diameter reduction rate is too large, FIG.
(B) As shown in (c), the die of the extruded raw pipe (1)
(3) is crushed and the corner protrudes, and a burr-like (b) or eave-like (c) defect (5) occurs on the surface of the drawn tube (2). On the other hand, if the cross-sectional area reduction rate is too small, as shown in FIGS. 6 (a) and 6 (b), the dice (3) is not sufficiently closed even by drawing, and remains as a concave defect (6). Therefore, it is necessary to perform the drawing so that the outer diameter reduction rate is 30% or less and the cross-sectional area reduction rate is 5% or more. A preferable outer diameter reduction rate is 10% or less, and a preferable cross-sectional area reduction rate is 20% or more.

When the outer diameter reduction rate is too small, the dice (3) is not sufficiently closed as shown in FIG. 6 (b) and remains as a concave defect (6). However, usually, when the pipe is drawn, both the outer diameter and the inner diameter are reduced, and if the cross-sectional area is reduced beyond the above ratio, the outer diameter is naturally reduced by a certain amount. Therefore, since setting the lower limit of the cross-sectional area reduction rate is equivalent to reducing the outer diameter at a certain ratio or more, the present invention does not set the lower limit of the outer diameter reduction rate. In addition, when the cross-sectional area reduction rate is too large, FIGS.
Burr-like or eave-like defects (5) may occur. However, setting the upper limit of the outer diameter reduction rate while securing the necessary wall thickness as a drawn tube is equivalent to reducing the cross-sectional area at a certain ratio or less. There is no upper limit.

According to the method of the present invention, the use of a low-viscosity lubricating oil makes it difficult to form oil pits, suppresses the occurrence of concave defects caused by the oil pits, and reduces the outer diameter at a predetermined rate. By pulling out the extruded tube at the rate of reduction in cross-sectional area, the dice existing on the outer peripheral surface of the extruded tube are closed and repaired without excess or shortage , and a drawn tube for the photosensitive drum substrate with high surface smoothness is manufactured. it can.

[0016]

Next, specific examples of the method for manufacturing a drawn tube for a photosensitive drum substrate according to the present invention will be described.

In each of the following examples, as a material for the drawn tube,
Outer diameter 38.0 made of JIS A3003 aluminum
An extruded raw tube having a size of 3 × 35.0 mm was used. And
With a drawing device (10) shown in FIG. 1 consisting of a combination of a drawing die (11) and a drawing plug (13) supported on a rod (12), the drawing is performed by drawing to each diameter shown in Table 1 below. A tube (2) was made. Also, during these withdrawals,
Lubricating oil was appropriately supplied between the drawing die (11) and the extrusion tube (1). The lubricating oil is “Strol (trade name)” manufactured by Kyoei Yuka Co., Ltd. and has a viscosity of 80 cst or 300 cst.
Was used. Table 1 shows the outer diameter reduction rate, cross-sectional area reduction rate, and lubricating oil viscosity of each drawn tube (2).

Further, regarding the outer peripheral surface of the processed drawn tube,
The surface roughness (Rmax) was measured and observed under an optical microscope and a scanning electron microscope to evaluate the presence or absence of burrs or eaves and the presence of oil pits according to the following criteria. Further, based on these results, the surface condition of the photosensitive drum substrate was comprehensively determined. Table 1 shows the evaluation results.
Are shown together.

(Rmax) ◎: less than 0.5 μm ○: 0.5 to 1 μm ×: more than 1 μm (burrs or eaves) ◎: Nothing of 5 μm or more in visual field ○: 5 to 10 μm in visual field None ×: Some area in the visual field exceeds 10 μm (oil pit) ◎: Area ratio of oil pit in visual field is less than 15% ○: Area percentage of oil pit in visual field is 15 to 50% ×: The area ratio of oil pits in the visual field exceeds 50% (Comprehensive judgment) ◎: Good as product ○: Normal as product ×: Fail as product

[Table 1]

[0020] As apparent from the results in Table 1, extraction tube pulled by the method of each embodiment, had a good surface condition as a photosensitive drum for group member.

[0021]

As described above, according to the present invention, an aluminum extrusion tube (1) is passed between a drawing die (11) and a drawing plug (13), so that the drawing die (11) and the extrusion tube are formed. (1)
While supplying lubricating oil between the extruded raw pipe (1)
In the method for manufacturing a drawn tube for a photosensitive drum substrate (2) by drawing the die , the extruded raw tube (1) is provided with a die (3) on the outer peripheral surface.
It is those having a viscosity as the lubricant 200cst
Use the following and pull out the tube from the extruded tube (1) (2)
Since the rate of reduction in outer diameter is 30% or less and the rate of reduction in cross-sectional area is 5% or more, the occurrence of concave defects due to oil pits is suppressed by the same number of steps as in the conventional drawing process. In addition, a die tube existing on the surface of the extruded tube can be repaired to produce a drawn tube for a photosensitive drum substrate having high surface smoothness. That is, while selecting and using a low-viscosity lubricating oil, it is only necessary to change the diameter of the drawing die and the drawing plug so that the reduction rate of the outer diameter and the sectional area of the drawing tube is within a predetermined range. It is not necessary to add or change the process.

[0022] Therefore, in the production of uncut ED tube which are used as conventionally photosensitive drum group member, by applying the method of the present invention, it is easily improved the surface smoothness of the aluminum tube it can.

[Brief description of the drawings]

FIG. 1 is a sectional view showing an example of a drawing apparatus used in an embodiment.

FIG. 2A is a partial cross-sectional perspective view of an extruded raw tube, and FIG. 2B is a partially cross-sectional perspective view schematically showing a state in which the extruded raw tube of FIG.

3A is a sectional view taken along line IIIa-IIIa of FIG. 2B, FIG. 3B is a sectional view taken along line IIIb-IIIb of FIG. 2B, and FIG. 3C is a sectional view of FIG. FIG. 3 is a sectional view taken along line IIIc-IIIc.

FIG. 4 is an explanatory diagram illustrating definitions of the outer diameter reduction rate and the cross-sectional area reduction rate in the present invention.

FIGS. 5A and 5B are diagrams showing a case where the outer diameter reduction rate of a drawn tube is large beyond the scope of the present invention, wherein FIG. 5A is a cross-sectional view of an extruded raw tube, and FIGS. It is.

FIG. 6 is a diagram showing a case where the cross-sectional area reduction rate of the drawn tube is less than the range of the present invention, (a) is a cross-sectional view of the extruded raw tube,
(B) is a sectional view of the drawn tube.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Extrusion element pipe 2 ... Drawing tube 3 ... Die eye 11 ... Drawing die 13 ... Drawing plug

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁶ , DB name) B21C 1/00 B21C 9/00

Claims (1)

(57) [Claims] 1. An aluminum extrusion tube (1) is passed between a drawing die (11) and a drawing plug (13), and a lubricating oil is provided between the drawing die (11) and the extrusion tube (1). And extracting the extruded raw tube (1) to produce a drawn tube (2) for a photosensitive drum substrate , wherein the extruded raw tube (1) has a die (3) Having
, And the viscosity as the lubricant using the following 200 cSt, and extruded raw pipe (1) 30% outside diameter reduction rate of the drawn pipe (2) from below, the cross-sectional area reduction rate is 5% or more A method for producing a drawn tube for a photosensitive drum substrate, the method comprising: