JP2005099774A - Aluminum tube superior in surface quality, manufacturing method thereof, manufacture device, and photoreceptor drum substrate - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a manufacturing method of manufacturing an aluminum tube which is free from surface defects like white scratches and is superior in surface quality, with high production efficiency. <P>SOLUTION: In the manufacturing method of drawing an extruded tube 4 after extruding an aluminum billet to obtain the extruded tube 4, the aluminum extruded tube 4 is cut in a position ≤10m off an ejection position M of an extrusion die to obtain the aluminum extruded tube 4 of which the length (R) is ≤10m, and this extruded tube 4 is subjected to drawing. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an aluminum tube excellent in surface quality that is suitably used as a photosensitive drum of an electrophotographic apparatus such as a copying machine, a printer, and a facsimile, a manufacturing method thereof, and a photosensitive drum substrate excellent in surface quality.

  In this specification, the term “aluminum” is used to include both aluminum and aluminum alloys.

  An aluminum tube used as a photosensitive drum of an electrophotographic apparatus such as a copying machine, a printer, or a facsimile machine is desired to have a surface state relatively close to a mirror surface due to its nature. Conventionally, mirror finishing has been carried out by cutting an aluminum tube, but adjustment and management of cutting tools are not easy, and the problem is that it is not suitable for mass production because it requires skill in work. there were.

Therefore, in recent years, an aluminum drawn tube called an ED tube obtained by drawing an aluminum extruded element tube has been widely used as a photosensitive drum base. This ED pipe is obtained by first extruding an aluminum billet to obtain an aluminum extruded element pipe, cutting the extruded element pipe into a predetermined length, and then performing a drawing process to improve the surface properties to obtain a predetermined diameter (outer diameter). It was manufactured by obtaining an aluminum tube defined in terms of dimensions, inner dimensions and wall thickness, and further washing (see Patent Document 1).
JP-A 63-188422

  However, the aluminum drawn tube manufactured as described above has a very fine and elongated streak-like surface defect (hereinafter simply referred to as “white mussel”) as shown in the optical micrograph of FIG. It occurred relatively frequently along the direction (in FIG. 14, white mussels extended obliquely upward to the right from the center of the photographic image). In recent years, photosensitive drums for electrophotographic apparatuses such as copying machines, printers, facsimiles and the like have been required to be able to realize excellent image quality. It was not possible to meet the demands. In the aluminum drawn tube obtained by the above-described conventional manufacturing method, the rate at which a good quality product free from surface defects such as white mussels is obtained, that is, the yield is about 70%. Therefore, the production efficiency is very high. It was bad. Accordingly, there has been an urgent need to develop a manufacturing method that does not cause such surface defects such as white mussels.

  The present invention has been made in view of such a technical background, does not cause surface defects such as white mussels, and can be manufactured with a production method and a production apparatus capable of producing an aluminum pipe excellent in surface quality with high production efficiency, and An object of the present invention is to provide an aluminum tube and a photosensitive drum substrate having excellent surface quality.

  In order to achieve the above object, the present inventor has tried to investigate the cause of the occurrence of white smears (surface defects). First, the present inventor thought that the following factors might cause or have an effect on the occurrence of white mussels.

(I) Influence of fluctuation of composition of raw billet (effect of impurity concentration, etc.)
(Ii) Deterioration of extrusion dies and drawing dies
(iii) Influence of the cooling method of the tube after extrusion (air cooling, mist cooling, etc.)
(Iv) Deterioration of the roller that transports the extruded element tube and adhesion of foreign matter (v) Dirt on the support receiving part of the extruded element tube and adhesion of foreign matter (vi) Influence of fluctuation (unstableness) in the drawing speed
(vii) Deterioration of lubricating oil used during drawing processing and contamination with foreign matter Carefully investigated whether the above factors that are likely to cause white spotting are the cause of white spotting. As a result of investigation, it has been clarified that none of the above factors (i) to (vii) is involved in the generation of white mussels. Therefore, the present inventor has made various attempts to investigate and investigate the cause of the occurrence of white mussels. As a result, when the extruded raw tube (about 50 m in length) is observed with an optical microscope in order from the extrusion die side to the distal end side in the extrusion direction, the occurrence frequency of white smear increases toward the distal end side in the extrusion direction. There was found. That is, it has been found that the generation rate of white mussels is low on the extrusion die side. Further, it was found that as a cause of white smearing, there is a possibility that the fibers of the felt layer on the surface of the roller for transferring the raw pipe immediately after extrusion adhere to the raw pipe surface. Therefore, when the fiber of the felt layer was intentionally adhered to the extruded element tube for confirmation and the drawing was performed, the same white muscular defect as shown in FIG. 14 was observed, which was caused by the adhesion of the fiber. I found out. When the time when the raw tube immediately after extrusion contacts the felt layer of the roller becomes long, the fibers adhere to the surface of the raw tube, and when drawing is performed in this state, along the drawing direction as shown in FIG. It is presumed that extended white mussels are generated on the tube surface. From such a series of various cause investigation and analysis results, in order to prevent the occurrence of white spotting, the extruded aluminum extruded tube is cut at a position within 10 m from the discharge position of the extrusion die, and the length is 10 m. The conclusion was reached that the following aluminum extruded tube should be obtained.

  That is, in order to achieve the above object, the present invention provides the following means.

  [1] A method for producing an aluminum tube by extruding an aluminum billet to obtain an aluminum extruded tube, and then drawing the extruded tube to form an extruded die. A method for producing an aluminum tube excellent in surface quality, characterized in that an aluminum extruded element tube having a length of 10 m or less is obtained by cutting at a position within 10 m from the discharge position, and the extruded element tube is subjected to the drawing process.

  [2] An extrusion process for obtaining an aluminum extruded element tube by extruding an aluminum billet, and the extruded aluminum extruded element tube is cut at a position within 10 m from the discharge position of an extrusion die, and an aluminum extrusion having a length of 10 m or less A method for producing an aluminum pipe excellent in surface quality, comprising: a cutting step for obtaining a raw pipe; and a drawing step for drawing an aluminum extruded raw pipe after the cutting to obtain an aluminum pipe.

  [3] The extruded aluminum extruded element tube is cut at a position within 10 m from the discharge position of the extrusion die to obtain an aluminum extruded element tube having a length of 1 to 6 m. A method for manufacturing an aluminum tube.

  [4] The extruded aluminum extruded element tube is cut at a position within 7 m from the discharge position of the extrusion die to obtain an aluminum extruded element tube having a length of 2 to 5 m. A method for manufacturing an aluminum tube.

  [5] Any one of items 1 to 4 above, wherein the extruded aluminum extruded tube is conveyed toward the extrusion direction while being supported by a support roller in which a synthetic fiber felt is circumferentially attached to the outer peripheral surface of the roller core portion. The manufacturing method of the aluminum pipe | tube excellent in the surface quality of any 1 item | term.

  [6] The method for producing an aluminum tube excellent in surface quality as described in 5 above, wherein the main fiber constituting the felt is an aramid fiber.

  [7] As the aluminum billet, Mn: 1.1 to 1.6 mass%, Si: 0.7 mass% or less, Fe: 0.8 mass% or less, Cu: 0.04 to 0.21 mass% Zn: The manufacturing method of the aluminum pipe excellent in the surface quality of any one of the preceding clauses 1-6 using the billet which contains 0.11 mass% or less and consists of remainder aluminum and an unavoidable impurity.

  [8] The length L in the extrusion direction of the die bearing part forming the outer surface of the aluminum extruded element tube is 5 mm or less, and the center line average roughness Ra (Y) in the circumferential direction of the bearing part and the center in the extrusion direction The surface quality according to any one of the preceding items 1 to 7, wherein the extrusion is performed using an extrusion die set to Ra (Y) <Ra (X). An excellent aluminum tube manufacturing method.

  [9] The preceding items 1 to 7 in which extrusion is performed using an extrusion die in which the bearing portion is formed of a super hard material and the surface roughness of the bearing portion is adjusted to Ry (maximum height) 5 to 30 μm. The manufacturing method of the aluminum pipe | tube excellent in the surface quality of any one of these.

  [10] The surface quality according to any one of items 1 to 9 above, wherein the surface roughness in the circumferential direction of the extruded aluminum tube obtained by the cutting is Ry (maximum height) of 0.5 to 10 μm. A manufacturing method of aluminum pipe.

  [11] When the extruded aluminum tube is drawn through a drawing die and a drawing plug to draw the extruded tube, the viscosity between the drawing die and the pushing tube is 200 cst or less. Any one of the preceding items 1 to 10, wherein the lubricating oil is supplied and is drawn so that the outer diameter reduction rate from the extruded tube to the aluminum tube is 30% or less and the cross-sectional area reduction rate is 5% or more. The manufacturing method of the aluminum pipe excellent in the surface quality as described in 1.

  [12] When the extruded aluminum pipe is drawn through a drawing die and a drawing plug to draw the extruded pipe, the rod is used as a rod for supporting the drawing plug. 12. The surface quality according to any one of the preceding items 1 to 11, wherein a rod having a configuration in which one or a plurality of cores contacting the peripheral surface is mounted over the entire length of the extruded element tube is used. A superior method of manufacturing aluminum tubes.

  [13] The method for producing an aluminum tube excellent in surface quality as described in [12] above, wherein a groove parallel to the axis is formed on the outer peripheral surface of the core.

  [14] When the extruded aluminum pipe is drawn by passing it through a drawing die and a drawing plug to draw the extruded pipe, an approach angle of 10 to 40 ° and a bearing length are used as the drawing die. Any of the preceding items 1 to 13, wherein a die set in a range of 8 to 25 mm is used, and a plug set in a range of an approach angle of 6 to 10 ° and a bearing length of 1.5 to 3 mm is used as the drawing plug. The manufacturing method of the aluminum pipe | tube excellent in the surface quality of 1 item | term.

  [15] The average length in the drawing direction of crystal grains on the surface of the extruded aluminum tube obtained by the cutting is 60 μm or more, and the average length in the drawing direction of the crystal grains is 1.3 times or more. The aluminum tube excellent in surface quality according to any one of items 1 to 14 above, wherein an aluminum tube having an average length in the drawing direction of the surface crystal grains exceeding 300 μm is obtained by drawing into an aluminum tube. Production method.

  [16] The method according to any one of items 1 to 15, wherein the aluminum tube obtained by the drawing process is cut off by a press cutting method, and then the aluminum tube is bent using a roll straightener. A method for manufacturing aluminum tubes with excellent surface quality.

  [17] The aluminum tube obtained by the drawing process is washed with a solvent having a KB (Kauributanol) value of 20 or more within 3 days after drawing, according to any one of the above items 1 to 16 For producing aluminum tubes with excellent surface quality.

  [18] The relationship between the ultrasonic frequency f (kHz) in the ultrasonic oscillator and the ultrasonic cleaning time T (min) of the aluminum tube obtained by the drawing process is expressed as f × T ≦ 120 (kHz · min). 18. The method for producing an aluminum tube having excellent surface quality according to any one of 1 to 17 above, wherein the ultrasonic cleaning is performed by setting.

[19] The relationship between the output P (W) of the ultrasonic oscillator and the ultrasonic oscillation area S (cm ² ) is set to 0.1 ≦ P / S ≦ 1.0 (W / cm ² ). 19. A method for producing an aluminum tube excellent in surface quality according to item 18 above.

  [20] The manufacturing method according to any one of items 1 to 19, wherein the aluminum tube is a photosensitive drum aluminum tube.

  [21] An aluminum tube manufactured by the manufacturing method according to any one of items 1 to 19.

  [22] A photosensitive drum substrate comprising an aluminum tube manufactured by the manufacturing method according to any one of items 1 to 19.

  [23] The photosensitive drum substrate according to [22], wherein the aluminum tube has substantially no fine streak-like surface defects extending on the surface in the drawing direction.

[24] an extruder;
A cutting machine that is disposed at a forward position in the extrusion direction of the extruder, and performs cutting while moving in synchronization with the moving speed of the aluminum extruding tube extruded from the extruder;
An aluminum tube manufacturing apparatus, wherein an aluminum extruded element tube is cut by a cutter at a position within 10 m from a discharge position of an extrusion die of the extruder.

  [25] The apparatus for producing an aluminum tube as recited in the aforementioned Item 24, wherein a support roller comprising a synthetic fiber felt is circumferentially disposed on an outer peripheral surface of a roller core portion between the extruder and the cutting machine. .

  [26] The production of an aluminum tube according to item 24 or 25, further comprising a control device that controls execution of the cutting operation of the cutting machine based on information on the moving speed of the aluminum extruded element tube obtained from the speed sensor. apparatus.

  [27] An aluminum drawn tube characterized by having substantially no fine streak-like surface defects extending substantially in the drawing direction on the surface.

  [28] A photosensitive drum substrate comprising an aluminum drawn tube substantially free of fine streak-like surface defects extending in the drawing direction on the surface.

  [29] A photosensitive drum characterized in that a photosensitive layer is coated on the outer peripheral surface of the photosensitive drum substrate of the above item 22, 23 or 28.

  [30] An electrophotographic apparatus constituted by using the photosensitive drum as described in 29 above.

  In the invention of [1], the extruded aluminum extruded element tube is cut at a position within 10 m from the discharge position of the extrusion die to obtain an aluminum extruded element pipe having a length of 10 m or less, and the extruded element tube is drawn. Thus, an aluminum tube free of surface defects such as white mussels can be manufactured, and as a result, an aluminum tube excellent in surface quality can be manufactured with high production efficiency. In this way, the occurrence of surface defects such as white mussels can be prevented because the time during which the extruded element tube in the high temperature state immediately after extrusion contacts the felt layer on the surface of the support roller is shortened, and the fibers of the felt layer become the surface of the element tube. It is estimated that it is possible to effectively prevent seizing and adhering to the surface.

  In the invention of [2], after the extruded aluminum extruded element tube is cut at a position within 10 m from the discharge position of the extrusion die to obtain an aluminum extruded element pipe having a length of 10 m or less, the extruded element tube is drawn. Therefore, an aluminum tube having no surface defects such as white mussels can be manufactured, and as a result, an aluminum tube excellent in surface quality can be manufactured with high production efficiency. In this way, the occurrence of surface defects such as white mussels can be prevented because the time during which the extruded element tube in the high temperature state immediately after extrusion contacts the felt layer on the surface of the support roller is shortened, and the fibers of the felt layer become the surface of the element tube. It is estimated that it is possible to effectively prevent seizing and adhering to the surface.

  In the invention of [3], generation of surface defects such as white mussels can be sufficiently prevented.

  In the invention of [4], the occurrence of surface defects such as white mussels can be reliably prevented.

  In the invention of [5], since the extruded element pipe is transported in the extrusion direction while being supported by a support roller around which a synthetic fiber felt is attached, a good surface is obtained without damaging the surface of the extruded element pipe. It can be conveyed while maintaining the state.

  In the invention of [6], since the main component of the fiber constituting the felt is an aramid fiber, it is possible to further sufficiently prevent the fibers of the felt layer from being seized and adhered to the surface of the extruded tube (high temperature state). .

  In the invention of [7], since the billet composition is regulated within the specific range, an aluminum tube suitable for a photosensitive drum can be manufactured.

  In the invention of [8], since the adhesion and migration of Al scum on the surface of the extruded aluminum extruded tube can be prevented, the surface smoothness can be improved, and the aluminum tube having a better surface quality Can be manufactured.

  In the invention of [9], it becomes easier to form a thin film of extruded material on the surface of the bearing portion of the extrusion die, thereby improving the affinity between the bearing portion and the extruded material, and reducing seizure during extrusion, An aluminum tube superior in surface smoothness can be produced.

  In the invention of [10], since the Ry in the circumferential direction of the extruded raw tube is defined within a specific range, it is possible to sufficiently generate ridge-like defects and hole-like defects caused by oil pits in the obtained aluminum pipe. Can be prevented. Accordingly, it is possible to suppress the accumulation of coating when thin film coating is performed on the surface of the aluminum tube, and thus it is possible to form a uniform image on the photosensitive drum.

  In the invention of [11], with the same number of steps as in the conventional drawing process, the occurrence of concave defects due to oil pits is suppressed, and the die existing on the surface of the extruded element pipe is repaired to achieve high surface smoothness. A drawn tube can be manufactured.

  In the invention of [12], one or more cores that contact the inner peripheral surface of the extruded element tube are mounted on the rod over the entire length of the extruded element pipe. It is possible to maintain the state in which the axis of the pipe is aligned with the axis of the die from the beginning to the end of drawing regardless of the length of the pipe. Thereby, the positional relationship of the three of the die, the plug, and the extruded element tube during drawing can be stabilized from beginning to end, and an aluminum tube (drawing tube) with less runout can be reliably manufactured.

  In the invention of [13], since the groove parallel to the axis is formed on the outer peripheral surface of the core, the lubricating oil at the time of drawing can be easily pulled backward, and the drawing can be performed particularly smoothly.

  In the invention of [14], an aluminum tube (drawn tube) having excellent surface smoothness and no variation in roundness, wall thickness, etc. can be reliably produced.

  In the invention of [15], an aluminum tube having further improved surface smoothness can be produced.

  In the invention of [16], since the bend of the aluminum tube is corrected by the roll straightening machine after the mouth part that becomes a foreign matter generation source is cut, the foreign matter is not brought into the roll straightening machine, and this is caused by the foreign matter. The bending of the aluminum tube can be corrected without scratching. Furthermore, since the cut-off portion is cut by the press cutting method, chips are not generated at the time of cutting, and therefore the bending of the aluminum tube can be corrected without causing scratches due to the chips.

  In the invention of [17], washing with a solvent having a KB value of 20 or more within 3 days after drawing out, there is almost no oil-based lubricant remaining on the surface of the aluminum tube, and the repelling of the photosensitive agent is remarkably reduced. . As a result, a uniform photosensitive layer without unevenness can be applied, so that the image quality can be further improved.

  In the invention of [18], it is possible to suppress the rise of convex defects on the surface of the aluminum tube. As a result, leakage of the photosensitive drum caused by the raised convex defects and generation of defects during coating of the photosensitive layer are prevented. It can be effectively prevented.

  In the invention [19], it is possible to reliably prevent the occurrence of surface roughness of the aluminum tube while ensuring sufficient cleaning power.

  In the invention [20], an aluminum tube suitable as a photosensitive drum of an electrophotographic apparatus such as a copying machine, a printer, or a facsimile can be manufactured.

  In the invention of [21], an aluminum tube excellent in surface quality can be provided.

  [22] According to the invention of [23], a photosensitive drum substrate excellent in surface quality suitable for a photosensitive drum of an electrophotographic apparatus such as a copying machine, a printer, or a facsimile is provided.

  According to the invention (production apparatus) of [24], an aluminum pipe free from surface defects such as white mussels can be produced, and as a result, an aluminum pipe excellent in surface quality can be produced with high production efficiency.

  In the invention of [25], it can be conveyed while maintaining a good surface state without damaging the surface of the extruded element tube.

  In the invention of [26], an aluminum extruded element tube precisely defined to a desired length can be manufactured.

  In the invention of [27], an aluminum tube excellent in surface quality can be provided.

  According to the invention [28], there is provided a photosensitive drum substrate excellent in surface quality, which is suitable for a photosensitive drum of an electrophotographic apparatus such as a copying machine, a printer or a facsimile.

  According to the invention [29], a photosensitive drum suitable for electrophotographic apparatuses such as copying machines, printers, facsimiles and the like and capable of forming excellent images is provided.

  According to the invention [30], an electrophotographic apparatus capable of realizing excellent image quality is provided.

  A method for manufacturing an aluminum tube excellent in surface quality according to the present invention will be described in the order of steps.

  First, an aluminum billet is extruded to obtain an aluminum extruded element tube (4) (extrusion process).

  In this extrusion, it is preferable to perform extrusion using an extrusion die having the following configuration. That is, the length L in the extrusion direction of the die bearing part forming the outer surface of the aluminum extruded element tube is 5 mm or less, and the center line average roughness Ra (Y) in the circumferential direction of the bearing part and the center line in the extrusion direction Extrusion is preferably performed using an extrusion die whose relationship with the average roughness Ra (X) is set such that Ra (Y) <Ra (X).

  At this time, the extrusion method is not particularly limited, and may be one using a porthole die or mandrel extrusion. FIG. 2 shows an example of a port hole die used for port hole extrusion. In FIG. 2, (1) is a die female die, and (2) is a die pressing die. The die female mold (1) is formed with a penetrating extrusion hole (11) at the center, and the peripheral surface on the inlet side of the extrusion hole is a circular bearing portion (12). Incidentally, (13) is a relief portion. On the other hand, the die pressing die (2) has a molding convex portion (21) having a circular cross section at the center thereof, and a circular bearing portion (22) is formed on the peripheral surface of the tip of the molding convex portion (21). Note that (23) is a passage hole through which the aluminum billet passes. Then, the die female die (1) and the die pressing die (2) are combined, and the tip of the molding convex portion (21) of the pressing die (2) faces the extrusion hole (11) of the female die (1). The bearing portions (12) and (22) are arranged opposite to each other via an annular forming gap (3).

  In this die, the length of the bearing portion forming the outer surface of the aluminum extruded element tube, that is, in the die of FIG. 2, the length L of the female bearing portion (12) in the pushing direction (indicated by the arrow X in FIG. 1) is 5 mm. The relationship between the center line average roughness Ra (Y) in the circumferential direction (indicated by arrow Y in FIG. 1) and the center line average roughness Ra (X) in the extrusion direction is Ra ( Y) <Ra (X) is set. If the length of the bearing portion (12) in the extruding direction exceeds 5 mm, the resistance during the extruding process increases, and molding cannot be performed unless the pushing force is increased. A particularly preferable range of the length of the bearing portion (12) in the extrusion direction is 3 mm or less. On the other hand, if the length of the bearing portion (12) in the extruding direction is too short, the strength of the bearing portion is reduced and the bearing portion is likely to be damaged, or the bearing portion is liable to be bent and the shape becomes unstable. Therefore, it is desirable to ensure a length of 1 mm or more.

  Moreover, since Ra (Y) <Ra (X) is set, the Al scum adhering to and deposited on the bearing part is easily captured by the groove on the bearing part surface, and the Al scum adheres to the surface of the extruded element tube. , Migration will be suppressed. The method for setting Ra (Y) <Ra (X) is not particularly limited. For example, it may be polished along the circumferential direction (Y direction) with a diamond file as shown in FIG.

  Furthermore, it is preferable to use an extrusion die satisfying the following conditions. That is, the extrusion die preferably has a bearing portion (12) formed of a super hard material, and the surface roughness of the bearing portion (12) is adjusted to Ry (maximum height) of 5 to 30 μm. By defining the surface roughness range within the specific range, it becomes easier to form a thin extruded material film on the surface of the bearing part (12), and the bearing part (12) is uniformly coated with a film having the same composition as the extruded material. Therefore, the affinity between the bearing portion (12) and the extruded material is improved, and seizure during extrusion can be alleviated, and the surface smoothness of the extruded element tube can be improved. If Ry is less than 5 μm, it is not preferable because the effect of forming a film is poor, and if Ry exceeds 30 μm, the surface smoothness decreases, which is not preferable. The surface roughness of the bearing part (12) is particularly preferably adjusted to Ry (maximum height) of 10 to 20 μm. Such a predetermined surface roughness of the bearing portion can be easily obtained by controlling, for example, the particle diameter and shot time of the sphere in the shot blast method. The cemented carbide material forming the bearing portion (12) is not particularly limited as long as it can be used as a normal die material such as various cemented carbides and ceramics. The Ry (maximum height) is defined in JIS B0601.

  Next, the extruded aluminum extruded element tube is cut at a position within 10 m from the discharge position of the extrusion die to obtain an aluminum extruded element tube (4) having a length of 10 m or less (cutting step). That is, the distance (Q) from the discharge position (M) of the extrusion die of the extruder (24) to the cutting position (N) by the cutting machine (25) is set within 10 m, and the cutting by the cutting machine (25) Is cut so that the length (R) of the extruded aluminum tube (4) obtained by the above is 10 m or less (see FIG. 3).

  FIG. 3 shows a schematic plan view of an apparatus related to the extrusion process and the cutting process. In FIG. 3, (24) is an extruder, (25) is a cutting machine, (26) is a support roller, (27) is a control device, and (28) is a speed sensor.

After the aluminum billet is introduced from the left end of the extruder (24), the aluminum extruding tube (4) is extruded from the discharge port of the extrusion die at the right end. The extrusion conditions are adjusted as appropriate. For example, the extrusion temperature is set to 450 to 530 ° C. The cutting machine (25) is disposed at a forward position in the extrusion direction of the extruder (24), and moves in synchronization with the moving speed of the aluminum extruding tube (4) extruded from the extruder (24). Then, the raw tube (4) is cut. At this time, the aluminum extruding tube (4) is cut by the cutting machine (25) at a position within 10 m from the discharge position (M) of the extrusion die of the extruder (24). A plurality of pairs of support rollers (26) and (26) are arranged between the extruder (24) and the cutting machine (25). It is preferable that the arrangement interval from the discharge position (M) of the extrusion die to the first pair of support rollers and the arrangement interval (m) of the pair of support rollers adjacent in the extrusion direction are set to 0.1 to 1 m. As shown in FIG. 4, the pair of support rollers (26) and (26) are arranged in such a manner that the axes are orthogonal to each other, and are arranged in an upwardly opened V shape. The extruded aluminum tube (4) extruded at the bottom position of the V-shaped opening is supported, and the extruded tube (4) is conveyed forward in the extrusion direction in such a supporting manner. As shown in the cross-sectional view of FIG. 5, the support roller (26) has a configuration in which a felt (26b) made of synthetic fiber is circumferentially attached to the outer peripheral surface of a tubular roller core (26a). Felt (26b) contacts and supports the extruded tube (4). In the present embodiment, an aramid fiber is used as the main fiber of the fiber constituting the felt (26b). Although the diameter of the said roller core part (26a) is not specifically limited, It is preferable to set to 20-100 mm. The ratio d ₁ / d ₂ of the diameter d ₂ of the roller core (26a) diameter d ₁ and extruded raw pipe (4) of preferably set in the range of 1-2. The thickness of the felt (26b) is preferably set to 5 to 15 mm.

  Speed sensors (28) and (28) are arranged on the sides of the aluminum extruded element pipe (4) extruded from the extruder (24), and the aluminum extruded element pipes obtained from these speed sensors (28) and (28). Based on the movement speed information of (4), the control device (27) controls the execution of the cutting operation of the cutting machine (25). That is, the extruded element pipe (4) is cut at a timing such that the length (R) of the aluminum extruded element pipe (4) obtained by cutting with the cutting machine (25) becomes 10 m or less.

  In this way, the extruded aluminum extruded tube (4) is cut at a position within 10 m from the discharge position (M) of the extrusion die, and an aluminum extruded elementary tube (4) having a length (R) of 10 m or less is obtained. By using this for the next drawing process, an aluminum drawn tube (5) free of surface defects such as white mussels can be produced, and as a result, an aluminum tube (5) excellent in surface quality is produced with high production efficiency. can do. In this way, the occurrence of surface defects such as white mussels can be prevented because the high-temperature extruded element tube (4) immediately after extrusion contacts the felt layer (26b) on the surface of the support roller (26). It is estimated that this is because the fibers of the felt layer (26b) can be effectively prevented from seizing and adhering to the surface of the base tube (4). In particular, the extruded aluminum extruded element tube (4) is cut at a position within 10 m from the discharge position (M) of the extrusion die to obtain an aluminum extruded element tube (4) having a length of 1 to 6 m. Preferably, the extruded aluminum extruded element tube (4) is cut at a position within 7 m from the discharge position (M) of the extrusion die to obtain an aluminum extruded element tube (4) having a length of 2 to 5 m. It is particularly preferable that

  Moreover, when the extrusion element pipe (4) is supported by a conventional roller conveyor, the contact point between the extrusion element pipe and the roller is one point, but in this embodiment, a pair arranged in an open V-shape upward. Since the support rollers (26) and (26) are used, there are two contact points, and the pressing force at the contact points is dispersed and reduced, so that the extruded tube (4) adheres to the support roller (26). Can be suppressed. Further, since the extruded aluminum extruded pipe (4) is cut at a position within 10 m from the discharge position (M) of the extrusion die, the weight of the blank pipe is naturally reduced, thereby reducing the pressing force at the contact point. Therefore, adhesion of the extruded element tube (4) to the support roller (26) can be sufficiently suppressed.

  The aluminum billet to be introduced into the extruder (24) is not particularly limited, but Mn: 1.1 to 1.6% by mass, Si: 0.7% by mass or less, Fe: 0.8% by mass In the following, it is desirable to use a billet containing Cu: 0.04 to 0.21 mass%, Zn: 0.11 mass% or less, and the balance aluminum and unavoidable impurities. In this case, it is particularly suitable for a photosensitive drum. There is an advantage that an aluminum tube can be manufactured.

  The surface roughness in the circumferential direction of the extruded aluminum tube (4) obtained by the cutting is preferably in the range of Ry (maximum height) of 0.5 to 10 μm. When the surface roughness exceeds 10 μm in Ry (maximum height), the surface of the aluminum tube obtained by the drawing process tends to have fine wrinkle-like defects, and this causes a thin film of the photosensitive layer as a photosensitive drum. When coating is performed, it tends to cause coating accumulation. On the other hand, if the surface roughness is less than 0.5 μm in Ry, the extruded element tube is too smooth and the lubricating oil during drawing is pushed between the drawing die and the element tube, and oil pits are formed on the surface of the resulting aluminum tube. It is not preferable because a hole-like defect is easily formed. The particularly preferable lower limit of the surface roughness in the circumferential direction of the extruded element tube (4) is 1 μm in Ry, and the same upper limit is 7 μm in Ry.

  The means for defining the surface roughness in the circumferential direction of the aluminum extruded element tube (4) in the range of Ry 0.5 to 10 μm is not particularly limited. For example, the extrusion direction of the die bearing part of the extrusion die For example, the length may be specified, or the extrusion speed may be suppressed to a certain value or less.

  Next, the aluminum extruded tube (4) obtained by the cutting is drawn to obtain an aluminum tube (aluminum drawn tube) (5) (drawing step).

  In this drawing step, the cut aluminum extruded element pipe (4) is passed between a drawing die (31) and a drawing plug (33), and the drawing die (31) and the extruded element pipe (4) are connected. Pulling out the extruded element tube (4) while supplying lubricating oil with a viscosity of 200 cst or less in the meantime, the outer diameter reduction rate from the extruded element tube (4) to the aluminum tube (5) is 30% or less, reducing the cross-sectional area Drawing is preferably performed so that the rate is 5% or more.

  If a lubricant having a high viscosity is used, if the lubricant is pushed between the drawing die (31) and the extruded element tube (4), an oil pit is easily formed, and a concave defect is likely to occur. If a lubricating oil of 200 cst or less is used, the formation of oil pits can be suppressed, and the occurrence of concave defects in the aluminum pipe (drawing pipe) (5) can be sufficiently suppressed. Particularly preferred lubricating oil has a viscosity of 100 cst or less. Examples of the lubricating oil having a viscosity of 200 cst or less include mineral oils and oils.

  The outer diameter reduction rate and the cross-sectional area reduction rate are respectively defined by the following equations (see FIG. 9).

Outer diameter reduction rate (%) = (D ₀ −D) / D ₀ × 100
Cross-sectional area reduction rate (%) = (S ₀ −S) / S ₀ × 100
When the outer diameter reduction rate exceeds 30%, the die of the extruded element tube (4) is crushed and the corners protrude, and burrs and eaves defects are likely to occur on the surface of the drawn tube (5). Therefore, it is not preferable. Also, if the cross-sectional area reduction rate is less than 5%, the die is not sufficiently closed even by drawing and may remain as a concave defect, which is not preferable. A particularly preferable outer diameter reduction rate is 10% or less, and a particularly preferable cross-sectional area reduction rate is 20% or more.

  Further, in the drawing step, that is, the extruded aluminum tube (4) after the cutting is passed between a drawing die (31) and a drawing plug (33) and drawn to draw the extruded tube (4). At this time, one or a plurality of cores (6) that contact the inner peripheral surface of the extruded element pipe (4) serve as the rod (32) for supporting the extraction plug (33). It is preferable to use a rod (32) (see FIGS. 6 to 8) configured to be mounted over the entire length.

  The core (6) attached to the rod (32) prevents the deflection of the element pipe (4) due to its own weight by contacting the inner peripheral surface of the extrusion element pipe (4). By attaching the child (6) over the entire length of the pipe (4), the axis of the pipe (4) is kept in line with the axis of the die (31) from the beginning to the end of drawing. it can. And by holding such a raw tube (4), it is possible to prevent a change in the positional relationship of the three of the die (31), the plug (33) and the raw tube (4) during drawing, so that the aluminum drawing The vibration of the tube (5) can be sufficiently suppressed.

  The core (6) may have any shape as long as it can hold the coaxiality between the drawing die (31) and the element pipe (4) by preventing the extrusion element pipe (4) from being bent, as shown in FIG. A substantially cylindrical shape (6a) (6b) (6c) can be illustrated. The cores (6a), (6b), and (6c) having such a shape are mounted on the entire circumference of the cores (6a), (6b), and (6c) by being inserted through the rod (32) at the center. A stable holding force can be obtained by inscribed in the tube (4). In addition, the core (6a) having a smooth outer peripheral surface as shown in FIG. 7 (a) has a large contact area with the base tube (4) and a large holding force, but on the other hand, the extracted lubricating oil is pulled back. Since it is difficult, as shown to FIG.7 (b) (c), what has the groove | channel (7) parallel to an axis line in an outer peripheral surface is preferable. The core (6b) shown in FIG. 7 (b) is provided with grooves (7) continuously on the entire outer peripheral surface, and the efficiency of lubricating oil removal is good, but the inner tube (4) The circumferential width of the contact surface (8) in contact with the peripheral surface is narrowed, and the holding force of the raw tube (4) is small. On the other hand, the core (6c) shown in FIG. 7 (c) is provided with a groove (7) at an appropriate interval on the outer peripheral surface, and is a contact surface (in contact with the inner peripheral surface of the base tube (4)). The width in the circumferential direction of 8) is widened, the holding force of the raw pipe (4) is large, and the lubricating oil is smoothly removed. Therefore, when providing a groove | channel (7) in a core (6), the shape of FIG.7 (c) is preferable. In FIGS. 7A, 7B, and 7C, the cores 6a, 6b, and 6c are illustrated as short cores, but the long core 6e also has a cross-sectional shape. Are common.

  The material of the core (6) is not particularly limited as long as it is a soft material that does not damage the extruded element tube (4), and is preferably made of a resin such as nylon, vinyl chloride, polyethylene, or polypropylene.

  The core (6) is connected to the rod (32) in order to secure a stable positional relationship between the drawing die (31), the drawing plug (33), and the pipe (4). 4) It is good to wear over the entire length. For mounting over the entire length, a plurality of short cores (6d) may be mounted at appropriate intervals as shown in FIG. 6, or one piece as shown in FIG. A long core (6e) may be used. In any case, it is possible to prevent the extruded element pipe (4) from being bent, and to sufficiently suppress the deflection of the aluminum pipe (drawing pipe) (5).

  Further, in the drawing step, that is, the extruded aluminum tube (4) after the cutting is passed between a drawing die (31) and a drawing plug (33) and drawn to draw the extruded tube (4). At this time, as the drawing die (31), a die having an approach angle of 10 to 40 ° and a bearing length of 8 to 25 mm is used, while as the drawing plug (33), an approach angle of 6 to 10 °, a bearing is used. It is preferable to use a plug having a length in the range of 1.5 to 3 mm (see FIGS. 10 and 11).

10 and 11 show a drawing die (31) and a drawing plug (33) for a ball drawing system. The drawing die (31) includes a die case (41) and a die body (42) made of a material such as die steel, cemented carbide, ceramics, etc., integrally fitted to the die case (41). It has a die hole (43) in the center and an approach portion (44), followed by a bearing portion (45) and a relief portion (46) around the die hole (43). . Therefore, the approach angle (θ ₁ ) of the approach portion (44) is preferably set in the range of 10 to 40 °. If the approach angle is less than 10 °, the degree of drawing is small and the shape, particularly the roundness of the aluminum tube (5), is difficult to be obtained, which is not preferable. On the other hand, when the approach angle exceeds 40 °, it is difficult to realize the surface smoothness of the aluminum tube (5), which is not preferable. The length (l ₁ ) of the bearing portion (45) that defines the outer diameter of the aluminum tube (5) is preferably set in the range of 8 to 25 mm. If the length of the bearing portion (45) is less than 8 mm, the roundness and thickness of the aluminum tube (5) will vary and the dimensions will become unstable. On the other hand, if the length of the bearing portion (45) exceeds 25 mm, seizure occurs and the surface smoothness of the aluminum tube (5) may be impaired, which is not preferable.

The extraction plug (33) also has an approach portion (51), followed by a bearing portion (52) and a relief portion (53). Accordingly, the approach angle (θ ₂ ) of the approach portion (51) of the plug (33) is preferably set in the range of 6 to 10 °. If the approach angle is less than 6 °, the roundness of the aluminum tube (5) is difficult to be obtained, which is not preferable. On the other hand, if the approach angle exceeds 10 °, the roundness and wall thickness of the aluminum tube (5) vary and the dimensions become unstable. Further, the length (l ₂ ) of the bearing portion (52) of the plug (33) is preferably set in a range of 1.5 to 3 mm. If the length of the bearing portion (52) is less than 1.5 mm, the roundness of the aluminum tube (5) is difficult to be obtained, which is not preferable. On the other hand, if the length of the bearing portion (52) exceeds 3 mm, seizure occurs and the surface smoothness of the aluminum tube (5) may be impaired, which is not preferable. The outer diameter of the bearing part (52) of the plug (33) and the inner diameter of the bearing part (45) of the die (31) are related to the inner and outer diameters and thickness of the aluminum pipe (5) to be manufactured. It goes without saying that it is determined by

  When the drawing die (31) and the drawing plug (33) are used for drawing, as shown in FIG. 11, the peripheral surface of the bearing portion (52) of the plug (33) is the bearing portion of the die (31). The die for drawing is combined with the substantially circumferential surface in the length direction of (45) so as to be opposed to each other through a gap corresponding to the desired thickness of the aluminum pipe (5). (54) is configured. And the extrusion element pipe (4) extruded by the extruder is pulled out as shown by a chain line in FIG. Although the drawing may be performed only once to obtain the aluminum tube (5), it is preferable to repeatedly perform the drawing a plurality of times and sequentially reduce the diameter to obtain the aluminum tube (5). . Among them, it is particularly preferable to obtain the aluminum tube (5) by performing drawing twice to reduce the diameter.

  In the above description, the drawing is performed by the ball drawing method. However, the drawing is not particularly limited thereto, and the drawing may be performed by a floating plug drawing method in which the plug is not fixed.

  Further, in the drawing step, it is preferable to perform drawing or the like so as to satisfy the following conditions. That is, the average length in the drawing direction of the crystal grains on the surface of the aluminum extruded element tube (4) obtained by the cutting is 60 μm or more, and the average length in the drawing direction of the crystal grains is 1.3 times or more. It is preferable to obtain an aluminum tube (5) whose average length in the drawing direction of the surface crystal grains exceeds 300 μm by drawing so as to be. The aluminum extruded element tube (4) having an average length in the drawing direction of the surface crystal grains of 60 μm or more is used if the average length in the drawing direction of the surface crystal grains is set to 300 μm in the subsequent drawing processing if it is less than 60 μm. It is because it becomes difficult to make it exceed. The longer the crystal grain length in the aluminum extruded element tube (4), the smaller the degree of processing for making the draw ratio, that is, the average length in the drawing direction of the crystal grains exceed 300 μm in the subsequent drawing process. However, it is desirable that the drawing ratio of the drawing process is performed so that the average length in the drawing direction of the surface crystal grains is 1.3 times or more. When the draw ratio is less than 1.3 times, fine irregularities such as die lines generated on the surface of the raw tube (4) can be removed by drawing, no matter how large the crystal grains in the aluminum extruded raw tube (4) are. This is not preferable because it becomes difficult and a mirror surface cannot be obtained. A particularly preferred draw ratio is 1.5 to 2.5 times. The average length of the crystal grains on the surface of the extruded aluminum tube (4) is adjusted by cold drawing the extruded tube (4) and then annealing at the recrystallization temperature or higher. It may be performed by adjusting the annealing temperature.

  Next, the aluminum pipe (5) obtained through the drawing process is straightened. This bending correction is preferably performed as follows. That is, it is preferable that the aluminum tube mouthpiece (57) obtained by the drawing process is cut by a press cutting method, and then the aluminum tube is bent and corrected using a roll straightening machine (61). First, the mouthpiece (57) of the extrusion tube (4) is passed through the die hole (43) from the rear side of the drawing die (31), the mouthpiece (57) is bitten by the chuck portion of the carriage (58), and the carriage (58) is moved forward to perform extraction (see FIGS. 6 and 8). Dirt concentrates on the mouth-attached portion (57) after drawing, and burrs are generated due to biting by the chuck. Therefore, the cut-out portion (57) is removed before bending correction. That is, as shown in FIG. 12 (a), the end of the aluminum drawn tube (5) on the side of the mouthpiece (57) is inserted into the mold (59) (59), and the cutting blade (60) The mouthpiece (57) is cut and removed by lowering. Since cutting is performed by the parting blade (60), no chips are generated. Thereafter, the aluminum drawn tube (5) is introduced into the roll straightening machine (61) from one end thereof, and straightened by the action of the internal straightening roll (62) (see FIG. 12 (b)). ). The aluminum drawing tube (5) is inserted into the roll straightening machine (61) after its mouthpiece (57) is cut without generating chips, so that foreign matter such as dirt, Al debris, chips and the like are not generated. It is not brought into the roll straightening machine (61), and therefore the aluminum drawing pipe (5) is not scratched during the straightening.

  Next, the aluminum pipe (5) subjected to the bending correction is washed. The lubricating oil is removed by this washing. This cleaning is preferably performed as follows. That is, it is preferable to wash the aluminum tube (5) with a solvent having a KB (Kauributanol) value of 20 or more within 3 days after drawing. Washing with a solvent within 3 days after drawing is difficult because the volatile components contained in the oil-based lubricant used at the time of drawing process evaporate and solidify when the time after drawing elapses. It is because removal will become difficult even if it uses a solvent with high degreasing power when it exceeds. The earlier the time of washing, the better the earlier, and the faster the withdrawal, the more complete removal is possible even with a solvent having a low degreasing power.

  The KB (kauributanol) value of the solvent indicates the dissolving ability of the solvent, that is, the degreasing power, and the test solvent is dropped at 25 ° C. into 20 g of a solution of 100 g of natural kauri gum dissolved in 500 g of butanol. Expressed by the number of mL of test solvent added before precipitation occurs, the higher the KB value, the greater the solubility. In this washing step, washing with a solvent having a KB value of 20 or more is preferable. This is because an oil-based lubricating oil cannot be sufficiently removed with a solvent having a low solubility of a KB value of less than 20 even if it is washed early within 3 days after drawing. Examples of the solvent having a KB value of 20 or more include kerosene (30), cyclohexane (60), toluene (100), aromatic naphtha (50-80), and dearomatized naphtha (20-30). Among these, it is particularly preferable to use a solvent having a KB value of 25 or more. Specific methods for cleaning are not particularly limited, and examples thereof include an immersion method and a shower method.

  Next, finish cleaning is further performed. As this final cleaning, it is preferable to perform the following ultrasonic cleaning. That is, for the aluminum tube (5), the relationship between the ultrasonic frequency f (kHz) in the ultrasonic oscillator and the ultrasonic cleaning time T (min) is set to f × T ≦ 120 (kHz · min). Ultrasonic cleaning is preferred. By carrying out cleaning under such conditions, it is possible to prevent the occurrence of convex defects on the surface of the aluminum tube (5). The reason is presumed as follows. That is, the product fT of the ultrasonic frequency f (kHz) and the ultrasonic cleaning time T (min) seems to be related to the cleaning energy, and when f × T> 120, the energy is too large and the convex defect. It is speculated that it will strike in the starting direction. Among these, it is particularly preferable to set f × T ≦ 100 (kHz · min). On the other hand, if fT is too small, the cleaning effect is poor, so the lower limit is preferably set to f × T ≧ 2 (kHz · min).

More preferably, the relationship between the output P (W) of the ultrasonic oscillator and the ultrasonic oscillation area, that is, the area S (cm ² ) of the vibrator is 0.1 ≦ P / S ≦ 1.0 (W / It is preferable to perform the ultrasonic cleaning described above by setting to cm ² ). If 0.1> P / S (W / cm ² ), the cleaning effect may be inferior regardless of the value of fT, which is not desirable. On the other hand, P / S> 1.0 (W / cm ² ) is not desirable because the surface of the aluminum tube (5) is roughened, which may increase leakage.

  The ultrasonic cleaning is for cleaning an aluminum tube, which is an object to be cleaned, by sending ultrasonic waves into the cleaning liquid. However, the ultrasonic irradiation method in the cleaning tank is not particularly limited. For example, a throwing type shown in FIG. 13A, an adhesive type shown in FIG. 13B, a vibration transmitter type shown in FIG. In FIG. 13, (71) is a cleaning tank, (72) is a plurality of aluminum tubes to be cleaned, (73) is a vibrator, (74) is a vibration transmitter, and (75) is a cleaning liquid. . As the cleaning liquid (75), white kerosene, light oil, alkali, surfactant, trichloroethylene or the like is generally used, but is not limited thereto, and water-based, hydrocarbon-based, chlorinated organic solvents, etc. are appropriately used. Use it.

  The distance between the vibrator or vibration transmitter and the aluminum tube is not particularly limited, but is preferably set to 2 to 50 cm.

  The aluminum tube (5) obtained through the extrusion process, the cutting process, the drawing process, the bending correction process, the cleaning process, and the finish cleaning process as described above is a fine streak-like surface defect extending substantially in the drawing direction on the surface. It has no (white mussels) and has excellent surface quality. Therefore, it is suitable as a photosensitive drum substrate of an electrophotographic apparatus such as a copying machine, a printer, or a facsimile.

  Next, specific examples of the present invention will be described.

<Example 1>
Mn: 1.12% by mass, Si: 0.11% by mass, Fe: 0.39% by mass, Cu: 0.16% by mass, Zn: 0.01% by mass, Mg: 0.02% by mass, The billet consisting of the remaining aluminum and inevitable impurities was extruded under the following extrusion conditions to obtain an aluminum extruded element tube (outer diameter 32 mm, wall thickness 1.5 mm). The surface roughness in the circumferential direction of this aluminum extruded element tube was Ry 2.5 μm. Moreover, the average length in the drawing direction of the crystal grains on the surface of the aluminum extruded element tube was 200 μm.
(Extrusion conditions)
Extrusion temperature: 520 ° C
Extrusion speed: 0.5 m / min Extrusion die: The port hole die shown in FIGS. The length L in the extrusion direction of the die bearing part was 3 mm. The relationship between the center line average roughness Ra (Y) in the circumferential direction of the bearing portion and the center line average roughness Ra (X) in the extrusion direction is set to Ra (Y) <Ra (X). The bearing portion was formed of a super hard material, and the surface roughness of the bearing portion was Ry 5.5 μm.

  Next, using the apparatus shown in FIG. 3, the aluminum extruded element tube extruded from the extruder (24) is cut by the cutting machine (25) at a position 7 m from the discharge position (M) of the extrusion die. A 4 m thick aluminum extruded element tube (4) was obtained. That is, in FIG. 3, Q = 7 m and R = 4 m were set. The composition of the fibers constituting the felt (26b) on the surface of the support roller (26) was 35% by mass of flameproofed fiber and 65% by mass of p-aramid fiber.

Subsequently, the aluminum extruded element tube (4) having a length of 2.2 m after being cut was subjected to a drawing process under the following drawing conditions to obtain an aluminum pipe (5) having an outer diameter of 24 mm and a wall thickness of 0.8 mm.
(Extraction conditions)
Pulling device: having the structure shown in FIG. 6 (the shape of the core adopts FIG. 7B)
Drawing die: Configuration shown in FIGS. 10 and 11 Drawing die: Approach angle 15 °, bearing length 15 mm
Pull-out plug: Approach angle 7 °, bearing length 2mm
Drawing speed: 15m / min Drawing frequency: 2 times Outer diameter reduction rate with 1 drawing: 16%
Cross-sectional area reduction rate with one drawing: 32%
Lubricating oil viscosity: 140 cst
Other drawing conditions: Drawing was performed so that the average length in the drawing direction of crystal grains was 1.8 times by drawing, thereby obtaining an aluminum tube having an average length in the drawing direction of surface crystal grains of 360 μm.

  Next, after the cut portion (57) of the aluminum tube (5) obtained by the drawing process is cut by a press cutting method, the aluminum tube (5) is bent and corrected using a roll straightening machine (61). (See FIG. 12).

Further, the aluminum tube after correction was cleaned with toluene (KB value: 100) within one day, and then ultrasonically cleaned under the following conditions to obtain an aluminum tube (5) for a photosensitive drum.
(Ultrasonic cleaning conditions)
Ultrasonic frequency f: 37 kHz
Ultrasonic cleaning time T: 1 minute f × T = 37 kHz · minute Ultrasonic oscillator output P: 2400 W
Ultrasonic oscillation area S: 4.760 cm ²
P / S = 0.5 W / cm ² .

<Examples 2 to 7>
The distance (Q) from the discharge position (M) of the extrusion die of the extruder (24) to the cutting position (N) by the cutting machine (25), and the length (R) of the extruded element tube (4) obtained by cutting ) Was set to the values shown in Table 1, and an aluminum tube for a photosensitive drum was obtained in the same manner as in Example 1.

<Comparative Example 1>
An aluminum tube for a photosensitive drum was obtained by a conventional manufacturing method. That is, the above-mentioned Q was set to 50 m and R was set to 50 m to obtain an aluminum tube for photosensitive drum.

<Comparative example 2>
An aluminum tube for a photosensitive drum was obtained in the same manner as in Example 1 except that Q was set to 20 m and R was set to 20 m.

<Comparative Example 3>
An aluminum tube for a photosensitive drum was obtained in the same manner as in Example 1 except that Q was set to 15 m and R was set to 15 m.

  For each of the above examples and comparative examples, 1000 aluminum tubes for the photosensitive drum were manufactured. Then, for each example, the surface of the 1000 aluminum tubes was observed with an optical microscope to check for the occurrence of white mussels (fine streak surface defects) on the surface, and to determine the number of tubes of good quality. The defect rate (%) due to the occurrence of white spots was calculated. Moreover, about these 1000 aluminum pipes, in addition to the presence or absence of the occurrence of white smearing, the presence or absence of other surface defects (presence of scratches, etc.), straightness, thickness deviation, and roundness are evaluated, and the respective desired standards are evaluated. The ratio of what passed in all these five evaluations, that is, the yield rate (%) for manufacturing the photosensitive drum aluminum tube was also determined. These results are shown in Table 1.

  As is apparent from Table 1, the aluminum pipes of Examples 1 to 7 manufactured by the manufacturing method of the present invention have a remarkably small occurrence of white mussels (fine streak-like surface defects) on the surface thereof. The defect rate due to the occurrence of white spots was remarkably reduced. Furthermore, the product yield rate was remarkably improved in comprehensive evaluation including the presence / absence of other surface defects, straightness, thickness deviation, and roundness. In contrast, the aluminum pipes of Comparative Example 1, Comparative Example 2, and 3 manufactured by the conventional manufacturing method have a high frequency of occurrence of white mussels (fine streak-like surface defects) on the surfaces thereof. The defect rate due to occurrence was high. Further, since the frequency of occurrence of white mussels is high, the product yield rate is low even in the comprehensive evaluation.

(A) is the elements on larger scale of the die bearing part of an extrusion die, (b) is the Ib-Ib line sectional enlarged view of (a), (c) is the Ic-Ic line sectional enlarged view of (a). It is sectional drawing which shows an example of the porthole die for extruding an extrusion element pipe. It is a schematic plan view of the manufacturing apparatus of this invention. It is sectional drawing of the IV-IV line in FIG. It is sectional drawing of a support roller. It is sectional drawing which shows an example of a drawing processing apparatus. (A) (b) (c) is a perspective view of a core, respectively. It is sectional drawing which shows the other example of a drawing processing apparatus. It is explanatory drawing explaining the definition of an outer diameter reduction rate and a cross-sectional area reduction rate. (A) is an enlarged vertical sectional view showing the main part of the drawing plug, (b) is an enlarged vertical sectional view showing the main part of the drawing die. It is a longitudinal cross-sectional view of the drawing die which combined the drawing plug and drawing die shown in FIG. (A) is a partial cross section side view which shows a lip attachment part cutting process, (b) is a side view which shows a correction process. (A) is sectional drawing which shows an example of an ultrasonic cleaner, (b) is sectional drawing which shows another example, (c) is a partially notched perspective view which shows another example. It is the optical microscope photograph of the surface of the aluminum drawing tube manufactured by the conventional method, (a) is a 37.5 times enlarged photograph, (b) is a 100 times magnified photograph.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Die female type | mold 2 ... Die stamping die 4 ... Aluminum extrusion element pipe 5 ... Aluminum drawing pipe 6 ... Core 7 ... Groove 12 ... Bearing part 24 ... Extruder 25 ... Cutting machine 26 ... Support roller 26a ... Core part 26b ... Felt (layer)
DESCRIPTION OF SYMBOLS 27 ... Control apparatus 28 ... Speed sensor 31 ... Extraction die 32 ... Rod 33 ... Extraction plug 57 ... Mouth part 61 ... Roll straightening machine

Claims (30)

A method for producing an aluminum tube by extruding an aluminum billet to obtain an aluminum extruded tube and then drawing the extruded tube;
The extruded aluminum extruded element tube is cut at a position within 10 m from the discharge position of the extrusion die to obtain an aluminum extruded element tube having a length of 10 m or less, and the extruded element tube is subjected to the drawing process. A method for manufacturing aluminum tubes with excellent surface quality. An extrusion process of extruding an aluminum billet to obtain an extruded aluminum tube;
Cutting the extruded aluminum extruded element tube at a position within 10 m from the discharge position of the extrusion die to obtain an aluminum extruded element tube having a length of 10 m or less;
A method for producing an aluminum tube excellent in surface quality, comprising: a drawing step of drawing an extruded aluminum tube after cutting to obtain an aluminum tube.   The aluminum tube excellent in surface quality according to claim 1 or 2, wherein the extruded aluminum extruded tube is cut at a position within 10 m from a discharge position of an extrusion die to obtain an aluminum extruded tube having a length of 1 to 6 m. Manufacturing method.   The aluminum tube excellent in surface quality according to claim 1 or 2, wherein the extruded aluminum extruded tube is cut at a position within 7 m from a discharge position of an extrusion die to obtain an extruded aluminum tube having a length of 2 to 5 m. Manufacturing method.   5. The extruded aluminum extruded tube is conveyed in the extrusion direction while being supported by a support roller in which a synthetic fiber felt is circumferentially attached to the outer peripheral surface of a roller core portion. The manufacturing method of the aluminum pipe | tube excellent in the surface quality as described in a term.   6. The method for producing an aluminum tube with excellent surface quality according to claim 5, wherein the main fiber constituting the felt is an aramid fiber.   As the aluminum billet, Mn: 1.1 to 1.6 mass%, Si: 0.7 mass% or less, Fe: 0.8 mass% or less, Cu: 0.04 to 0.21 mass%, Zn: The manufacturing method of the aluminum tube excellent in the surface quality of any one of Claims 1-6 which uses 0.11 mass% or less and uses the billet which consists of remainder aluminum and an unavoidable impurity.   The length L in the extrusion direction of the die bearing portion forming the outer surface of the aluminum extruded element tube is 5 mm or less, and the center line average roughness Ra (Y) in the circumferential direction of the bearing portion and the center line average roughness in the extrusion direction The surface quality according to any one of claims 1 to 7, wherein the extrusion is performed using an extrusion die in which Ra (X) is set such that Ra (Y) <Ra (X). A method for manufacturing an aluminum tube.   Any of Claims 1-7 which extrude using the extrusion die by which the bearing part is formed with the super hard material, and the surface roughness of this bearing part is adjusted to Ry (maximum height) 5-30 micrometers. The manufacturing method of the aluminum pipe | tube excellent in the surface quality of any 1 item | term.   The aluminum having excellent surface quality according to any one of claims 1 to 9, wherein the surface roughness in the circumferential direction of the extruded aluminum pipe obtained by the cutting is Ry (maximum height) of 0.5 to 10 µm. A method of manufacturing a tube. When the extruded aluminum pipe is drawn by passing the extruded aluminum pipe after being cut between a drawing die and a drawing plug,
Lubricating oil having a viscosity of 200 cst or less is supplied between the drawing die and the extruded element tube, and the outer diameter reduction rate from the extruded element tube to the aluminum tube is 30% or less, and the cross-sectional area reduction rate is 5% or more. The manufacturing method of the aluminum pipe excellent in the surface quality of any one of Claims 1-10 which draw-process so that it may become. When the extruded aluminum pipe is drawn by passing the extruded aluminum pipe after being cut between a drawing die and a drawing plug,
As the rod for supporting the pull-out plug, a rod having a configuration in which one or a plurality of cores that are in contact with the inner peripheral surface of the extruded element pipe is mounted over the entire length of the extruded element pipe is used. The manufacturing method of the aluminum pipe | tube excellent in the surface quality of any one of Claims 1-11 to do.   The manufacturing method of the aluminum pipe excellent in the surface quality of Claim 12 with which the groove | channel parallel to an axis line is formed in the outer peripheral surface of the said core. When the extruded aluminum pipe is drawn by passing the extruded aluminum pipe after being cut between a drawing die and a drawing plug,
As the drawing die, a die having an approach angle of 10 to 40 ° and a bearing length of 8 to 25 mm is used, while as the drawing plug, an approach angle of 6 to 10 ° and a bearing length of 1.5 to 3 mm is used. The method for producing an aluminum tube having excellent surface quality according to any one of claims 1 to 13, wherein a plug set in a range is used.   Drawing process so that the average length in the drawing direction of the crystal grains on the surface of the extruded aluminum tube obtained by the cutting is 60 μm or more, and the average length in the drawing direction of the crystal grains is 1.3 times or more. The method for producing an aluminum tube excellent in surface quality according to any one of claims 1 to 14, wherein an aluminum tube having an average length in the drawing direction of crystal grains on the surface exceeding 300 µm is obtained. .   The surface quality according to any one of claims 1 to 15, wherein the aluminum pipe obtained by the drawing process is cut off by a press cutting method, and then the aluminum pipe is subjected to bending correction using a roll straightening machine. A superior method for producing aluminum tubes.   The surface according to any one of claims 1 to 16, wherein the aluminum tube obtained by the drawing process is washed with a solvent having a KB (Kauributanol) value of 20 or more within 3 days after drawing. A method of manufacturing aluminum tubes with excellent quality. The aluminum tube obtained by the drawing process,
The ultrasonic cleaning is performed by setting the relationship between the ultrasonic frequency f (kHz) and the ultrasonic cleaning time T (min) in the ultrasonic oscillator to f × T ≦ 120 (kHz · min). The manufacturing method of the aluminum pipe | tube excellent in the surface quality of any one of Claims 1. The ultrasonic cleaning is performed by setting the relationship between the output P (W) of the ultrasonic oscillator and the ultrasonic oscillation area S (cm ² ) to 0.1 ≦ P / S ≦ 1.0 (W / cm ² ). Item 19. A method for producing an aluminum tube excellent in surface quality according to Item 18.   The manufacturing method according to claim 1, wherein the aluminum tube is a photosensitive drum aluminum tube.   The aluminum pipe manufactured by the manufacturing method of any one of Claims 1-19.   A photosensitive drum substrate comprising an aluminum tube manufactured by the manufacturing method according to claim 1.   23. The photosensitive drum substrate according to claim 22, wherein the aluminum tube has substantially no fine streak-like surface defects extending in the drawing direction on the surface. An extruder,
A cutting machine that is disposed at a forward position in the extrusion direction of the extruder, and performs cutting while moving in synchronization with the moving speed of the aluminum extruding tube extruded from the extruder;
An aluminum tube manufacturing apparatus, wherein an aluminum extruded element tube is cut by a cutter at a position within 10 m from a discharge position of an extrusion die of the extruder.   The apparatus for manufacturing an aluminum tube according to claim 24, wherein a support roller is provided between the extruder and the cutting machine. The support roller is formed by surrounding a felt made of synthetic fiber on the outer peripheral surface of the roller core portion.   The apparatus for producing an aluminum pipe according to claim 24 or 25, further comprising a control device for controlling execution of a cutting operation of the cutting machine based on information on a moving speed of the aluminum extruded raw tube obtained from a speed sensor.   An aluminum drawn tube characterized by having substantially no fine streak-like surface defects extending in the drawing direction on the surface.   1. A photosensitive drum substrate comprising an aluminum drawn tube substantially free from fine streak-like surface defects extending in the drawing direction on the surface.   A photosensitive drum, wherein a photosensitive layer is coated on the outer peripheral surface of the photosensitive drum substrate according to claim 22, 23 or 28.   30. An electrophotographic apparatus configured using the photosensitive drum according to claim 29.