JP2013105057A - Metal tube and manufacturing method thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a metal tube formed by providing a sure and stable spiral pattern shape on a metal tube with thin wall thickness by spinning and roughing the outer peripheral surface thereof, and to provide a manufacturing method thereof.SOLUTION: The metal tube has a hollow-core tube body made of metal and has uniform wall thickness of 20 to 50 μm. The metal tube is obtained by spinning while being pressed by a top disposed on the outer periphery thereof. By the spinning, rugged parts are formed on the outer peripheral face and inner peripheral face of the metal tube at a substantially fixed interval. Later, the outer peripheral face of the metal tube is roughened by the spinning by using another top 5a having a tip end angle sharper than that of the top .

Description

  The present invention relates to a metal tube and a manufacturing method thereof. Specifically, the present invention relates to a metal tube used for an electrophotographic printer, a fixing roller of a copying machine, and the like, and a manufacturing method thereof. More specifically, the present invention relates to a metal tube that is spun and used for a fixing roller and the like, and a manufacturing method thereof.

  A metal tube made of metal and having a through-hole in the center is used as a fixing tube for a laser beam printer or the like. This fixing tube is used in a different manner from monochrome copying machines, color copying machines, color printers, and the like. In a monochrome copying machine, a method of fixing an image, characters, and the like by fixing toner on a sheet with a heated roller (fixing roller) is widely used.

  Many fixing rollers for performing such fixing generally have a thin metal tube coated or coated with fluorine resin (fluororesin) on the surface of the metal tube. As a technique related to a metal tube, a method of manufacturing a metal plate by plastic working has been proposed. In the technique of plastic processing of this metal tube, the present applicant has proposed a technique of processing a thin metal cylinder by performing rotational plastic processing, that is, spinning processing (see, for example, Patent Document 1). .

  Also in Patent Document 2, a belt using stainless steel whose strength has been increased by spinning is used as a photoreceptor. When the thickness of the metal cylinder is reduced, for example, when used as a fixing roller for a copying machine, the thickness is reduced as much as possible within the range that can withstand the required mechanical strength because of the advantage of a short preheating time. Better. Further, as a tube processing technique of a fluororesin to be coated on a metal tube, a fluorine tube for a fixing member having an axial shrinkage rate of 1 to 8% and a radial shrinkage rate of 2 to 8% when heated at 150 ° C. has been proposed. .

  Further, a manufacturing method is disclosed in which minute uneven portions are formed at substantially constant intervals on the outer peripheral surface and the inner peripheral surface of a metal tube (see Patent Document 3). The metal tube according to this manufacturing method is a hollow metal tube having a uniform thickness of 20 to 50 μm and a metal ring-shaped metal original, together with a rotating support, the metal original. It is the metal tube processed by the spinning process which rotates the circumference | surroundings of the center axis of this, and presses the frame | tip arrange | positioned on the outer periphery of the said metal original body, and plastically processes it. After spinning, both ends of the metal original body are cut into a tube.

  Patent Document 4 discloses a belt tubular body in which a plurality of irregularities extending in a predetermined direction are formed on the inner peripheral surface of a fixing belt, and circulates with the rotation of the rotating body while retaining a lubricant in these irregularities. doing. This uneven | corrugated | grooved part is formed by cutting the surrounding surface of an iron cylinder. Patent Document 5 discloses a fixing roller in which a spiral rib is formed on an inner week surface in order to hold a lubricant. In order to obtain this fixing roller, a spiral groove is formed on the outer peripheral surface of the core metal by spinning, and at the same time, a spiral rib is formed on the inner week surface thereof. Thereafter, a groove on the outer peripheral surface is cut and flattened by diamond cutting to obtain a fixing roller having ribs on the inner week surface.

JP 2004-174555 A JP 2001-225134 A International publication WO2009 / 060692 JP 2006-267408 A JP 2001-109306 A

  However, even if the above-described metal original body is made into a tube by spinning, the surface of the metal tube is then roughened, and the surface of the metal tube is coded with a fluororesin or the like. The roughening treatment of the metal tube surface is performed by processing such as sand blasting, grinding, or laser. From these processing treatments, a roughening treatment of the metal tube surface that is simple and inexpensive is required.

For example, in the case of Patent Document 4, the surface of a stainless steel pipe manufactured by drawing on the core is subjected to a roughening process by honing. In this honing process, since the inner diameter of the stainless steel pipe is polished using a tool such as a cylindrical spindle with a grindstone, the roughening process takes time.
The present invention has been made based on the technical background as described above, and achieves the following objects.

An object of the present invention is to provide a metal tube capable of giving a reliable and stable spiral patterned shape to a thin metal tube by spinning.
Another object of the present invention is to provide a metal tube manufacturing method capable of manufacturing a tube having a spiral pattern at a low cost.
A further object of the present invention is to provide a metal tube capable of giving a spiral patterned shape by spinning in order to roughen the outer peripheral surface of a thin metal tube, and a method for producing the metal tube Is to provide.

In order to achieve the above object, the present invention employs the following means.
The metal tube according to the first aspect of the present invention is a metal tube having a hollow core, a uniform thickness of 20 to 50 μm, and a metal annular metal prototype with a rotating support. An outer peripheral surface and an inner periphery of the metal original body are rotated by a first spinning process in which the first frame arranged on the outer periphery of the metal original body is pressed and plastically processed by rotating around the central axis of the metal original body. A metal tube having irregularities formed on the surface at substantially regular intervals, and after the first spinning process, in order to roughen the outer peripheral surface of the metal tube, the angle of the tip is the first angle By arranging and pressing the second frame, which is sharper than the frame, on the outer periphery of the metal tube and performing plastic processing, minute uneven portions are formed at substantially constant intervals on the outer peripheral surface and inner peripheral surface of the metal original body. The minute irregularities are formed on the metal tube. Characterized in that the outer and inner peripheral surfaces of the blanking is made to roughening.

A metal tube according to a second aspect of the present invention is the metal tube according to the first aspect, wherein the minute uneven portions are minute uneven portions having a dimensional difference of 0.3 μm or more at substantially constant intervals, and the outer peripheral surface of the metal tube. Has a surface roughness Rz of 3 μm or more.
A metal tube according to a third aspect of the present invention is the metal tube according to the first or second aspect, wherein the metal tube is a tube for a fixing roller or belt used in an electrophotographic printer or a copying machine, and has a micro unevenness on the inner surface. The portion is a reservoir of lubricating oil.

  The metal tube manufacturing method according to the fourth aspect of the present invention is a rotating support for processing a metal original body made of a metal that can be plastically processed into a surface shape having inner and outer diameter surface shapes with minute irregularities at substantially constant intervals. A cylindrical portion of the metal original body that is plastically processed by pressing the first frame while rotating the attached metal original body around the central axis of the metal original body together with the rotating support. A first spinning process for performing a spinning process in which the wall thickness of the inner and outer diameters is reduced to a uniform thickness of 20 to 50 μm, and the inner and outer diameter surface shapes have irregularities at regular intervals, and the first spinning process Thereafter, in order to roughen the outer peripheral surface of the metal tube, the spinning metal base body is rotated around the central axis of the metal base body together with the rotary support. Then, the second frame having a sharper tip angle than the first frame is pressed and plastically processed, and the metal original body subjected to the spinning process is minutely formed at substantially constant intervals on the outer peripheral surface and the inner peripheral surface. Production of a metal tube comprising: a second spinning process for performing a spinning process with a surface having an uneven part; and a process of cutting both ends of the metal original body into a tube shape after the second spinning process. The method is characterized in that the surface having the minute concavo-convex portion is a surface having a fine concavo-convex indentation.

The method for producing a metal tube according to a fifth aspect of the present invention is the method according to the fourth aspect, wherein the minute uneven portion is a minute uneven portion having a dimensional difference between a peak and a valley of 0.3 μm or more at substantially constant intervals. The outer peripheral surface has a surface roughness Rz of 3 μm or more.
The method for producing a metal tube according to a sixth aspect of the present invention is characterized in that, in the fourth or fifth aspect, the material of the original metal form is stainless steel.

  According to a seventh aspect of the present invention, there is provided a metal tube manufacturing method of the present invention, wherein the metal tube is for a fixing roller or belt used in an electrophotographic printer or copying machine. The minute irregularities on the inner diameter surface are a reservoir of lubricating oil.

According to the present invention, the following effects can be obtained.
As described above, the metal tube manufacturing method of the present invention enables the formation of fine irregularities on the surface of the metal tube for the roughening treatment at the process step of spinning. This eliminates the need for sandblasting, which has been conventionally used to roughen the surface of the metal tube, and simplifies the manufacturing process. Further, the subsequent processing steps such as coating processing can be performed in the same process flow as before, and the manufacturing process is simplified.

  Therefore, the manufacturing cost can be reduced as compared with the prior art. The metal tube of the present invention is formed with a spiral pattern of fine irregularities by spinning. Therefore, the pattern on the outer peripheral side surface of the tube is formed with a minute uneven shape having the same pattern on the inner peripheral surface. The minute uneven shape on the inner peripheral surface of the metal tube becomes a pool of liquid such as lubricating oil, and this spiral patterned minute uneven shape has an effect of having a lubrication holding function.

FIG. 1 is a cross-sectional view showing a metal tube 1 according to an embodiment of the present invention. FIG. 2 is an explanatory diagram for explaining a process of spinning the bottomed element tube 2 that is a material of the metal tube 1 according to the embodiment of the present invention. FIG. 3 is a diagram illustrating the shape of the top 5a used in the roughing spinning process of the metal tube 1 according to the embodiment of the present invention. FIG. 4 is an explanatory diagram for explaining a process of cutting the bottomed element tube 2 into the metal tube 1. FIG. 5 is a conceptual diagram showing spiral pattern indentations 6 formed on the surface of the metal tube 1 according to the embodiment of the present invention. FIG. 6 is a diagram illustrating the shape of the top 5 used for spinning the metal tube. 7A, 7B, and 7C are graphs showing the measurement results of the outer surface of the bottom of the bottomed element tube of the example. 8A, 8B, and 8C are graphs showing the measurement results of the outer surface of the flange portion of the bottomed element tube. 9A, 9B, and 9C are graphs showing the measurement results of the inner surface of the bottom of the bottomed element tube. 10A, 10B, and 10C are graphs showing measurement results of the inner surface of the flange portion of the bottomed element tube. FIG. 11 is a graph showing another measurement example of the surface roughness Rz of the surface of the metal tube. FIG. 12 is a graph showing the results of measuring the outer shape of the metal tube of FIG. FIG. 13 is a graph showing the results of measuring the surface roughness of the inner surface of the metal tube of FIG.

Hereinafter, embodiments of the present invention will be described in detail.
FIG. 1 is a cross-sectional view showing a metal tube 1 of the present invention. FIG. 2 is an explanatory diagram for explaining a process of spinning the bottomed element tube 2 that is a material of the metal tube 1. The spinning process itself is a known technique as disclosed in Patent Document 1 and Patent Document 3 by the present applicant. Although not shown, the bottomed element tube 2 is made by pressing a metal thin plate between a female die and a punch. The bottomed element tube 2 becomes a metal original form of the metal tube 1.

  The deeper the bottomed tube 2 is, the easier it is to spin, so it is formed by the hot deep drawing method in which the female die is heated and the punch is cooled at the time of pressing, or plastic processing of cold deep drawing. Is done. In the present embodiment, the metal thin plate of the material for the bottomed bare tube 2 is stainless steel such as SUS304 (corresponding to US AISI 304). Moreover, the metal thin plate of the material for the bottomed element tube 2 may be aluminum alloy, nickel, iron or the like in addition to stainless steel.

  As shown in FIG. 2, the bottomed element tube 2 is subjected to processing to further reduce the thickness by a spinning processing machine 3. The bottomed element tube 2 is inserted into the rotation base shaft (mandrel) 4 of the spinning machine 3 and gripped to rotate. The rotation base 4 is also a mold that determines the shape of the bottomed tube 2. In the spinning process by the spinning machine 3, the bottomed bare tube 2 having a small thickness is forced to follow the outer peripheral surface of the rotating base shaft 4 to obtain the metal tube 1.

  A plurality of cones 5 having a conical shape are arranged at equal angular intervals on the outer periphery of the bottomed tube 2. The top 5 has a shape like an abacus ball and is a type of tool that is rotatably provided. Then, while rotating the bottomed element tube 2, the top 5 is brought into contact with the outer peripheral surface of the bottomed element tube 2 and pressed in a uniform and constant pressure in the direction of arrow A (in the direction of the rotation center axis of the rotation base shaft 4). Move. An arrow B illustrated in FIG. 2 illustrates the rotation direction of the rotation base shaft 4. Both ends of the bottomed element tube 2 have higher rigidity than the center part.

  The bottomed element tube 2 has its cylindrical portion gradually reduced in thickness according to the pressing movement of the top 5, and the wall thickness is reduced, and in other words, the direction of the center axis of the rotation base 4, in other words, the center axis of the bottomed element tube 2. The length of the direction becomes longer. When the top 5 passes along the center axis direction of the bottomed element tube 2 according to the spinning process, the processed surface of the bottomed element tube 2 is formed into an uneven shape having a spiral patterned impression described later. . By this spinning process, the thickness of the bottomed element tube 2 is reduced. At the stage where the intermediate processing shape is the bottomed element tube 2, the wall thickness can be 20 to 50 μm, and in this embodiment, such a shape is obtained.

  In the present embodiment, the bottomed element tube 2 made of a metal that can be plastically processed is subjected to a spinning process to reduce the thickness thereof, and the concave-convex shape that is a spiral patterned impression is formed in the bottomed element tube 2. Form on the wall. In the case of stainless steel SUS304, such spinning processing is performed by increasing the limit drawing ratio to 2.6 in the warm drawing method. In this way, when the bottomed bare tube 2 subjected to the spinning process is stainless steel SUS304, the tensile strength is 1666 MPa (170 kgf / mm 2), and the fatigue strength is 980 MPa (100 kgf / mm 2) or more, depending on conditions. Become.

  First, in the spinning process, a top 5 having a shape as shown in FIG. 6 is used. The frame 5 has a conical shape. The pressed surface that is plastically processed by the top 5 is the outer peripheral surface of the bottomed element tube 2. The outer peripheral surface is reciprocated several times by the frame 5 to perform a desired spinning process. After this processing is completed, the finishing piece 5a with a sharper tip is replaced with a roughing spinning process in one pass. The shape of the frame 5a is shown in FIG. Since the edge angle of the finishing piece 5a is sharper than the edge angle of the piece 5, a slightly spiral multi-groove is formed.

  In this roughing spinning process, finer irregularities are formed on the irregularities, which are spiral patterned indentations formed on the wall of the bottomed tube 2 in the first spinning process. When the roughing spinning process is performed in this way and the bottomed element tube 2 having a small wall thickness is formed, the bottomed element tube 2 is removed from the rotating base shaft 4. FIG. 4 is an explanatory diagram for explaining a process of cutting the bottomed element tube 2 into the metal tube 1. Both ends of the bottomed raw tube 2 pulled out from the rotating base shaft 4 are cut off by a cut-off tool or the like (not shown).

  In other words, the bottom portion 2 a and the flange portion 2 b of the bottomed element tube 2 are cut, and the central portion of the bottomed element tube 2 is the metal tube 1. Thus, the metal tube 1 is a non-elementary tube. By this cutting, the cylindrical body of the bottomed element tube 2 becomes a metal tube 1 such as a fixing roller or a belt. After cutting, the metal tube 1 may be subjected to low temperature annealing at a temperature of around 450 ° C. in order to adjust the spring property, remove internal stress, and form a uniform shape. By this low-temperature annealing, the hardness of the low-element tube 2c, in other words, the metal tube 1 is increased, and the tensile strength and fatigue strength are increased.

  Further, in the process of spinning the metal tube 1, a spiral pattern indent 6 is formed on the surface of the bottomed element tube 2 as shown in FIG. 5. The indentation 6 is generated by the press-contact movement of the top 5 and the top 5a, and fine regular irregular surfaces are formed at constant intervals on the inner and outer peripheral surfaces of the bottomed tube 2. This spiral pattern is also a trace of indentation due to spinning by the top 5 and the top 5a. Therefore, it is a fine regular concavo-convex surface formed by the multi-spiral pattern formed on the outer peripheral surface of the metal tube 1 by the top 5 and the top 5a.

  The number of spiral patterns varies depending on the number of frames 5 and 5a. For example, the fine regular uneven surface formed by the three frames 5 and the frame 5a has a triple spiral pattern. Since the bottomed element tube 2 is a thin tube, the indentation 6 is formed on the outer peripheral surface side and the inner peripheral surface side of the bottomed element tube 2. The formation of this indentation 6 which is a minute regular uneven surface is an important technical feature when this bottomed raw tube 2, in other words, the metal tube 1, is used as a product such as a roller. It is effective.

  For example, when this is used for a fixing roller of a copying machine, a high frequency heater for heating is incorporated in the inner hole, and the fixing roller rotates. At this time, the high frequency heater and the inner peripheral surface of the fixing roller Between them is a lubricating oil for lubrication. The indentation 6 on the inner peripheral surface side of the fixing roller becomes a pool of this lubricating oil, and the sliding of the inner peripheral surface of the high frequency heater and the fixing roller becomes smooth.

  The roughing spinning process is an alternative process to the sandblasting process that has been used in the production of conventional metal tubes. As a result, the metal tube 1 does not need to be sandblasted as in the prior art. Spinning has fewer steps than sandblasting, and only the frame 5 needs to be changed to the frame 5a. Therefore, the machining process can be reduced and the cost can be saved. The metal tube 1 of the present invention is completed as a tube 10 through a process such as coating the outer peripheral surface with a coating material 7 for final production.

  In these steps, the thickness and shape of the metal tube 1 are constant and unchanged. In the second spinning process, fine irregularities are generated on the surface of the metal tube 1 to increase the surface area and activate the surface. As a result, residual compressive stress is generated on the surface to increase the fatigue strength. The coating material 7 used in the coating process is a fluororesin. The fluorine resin of the coating material 7 is a polymer that can be plasticized and molded by heat. For example, as a material excellent in moldability, heat resistance, etc., a binary copolymer of ethylene and ethylene trifluoride chloride, or For example, a binary copolymer of tetrafluoroethylene and perfluoroalkyl vinyl ether. In addition to the fluororesin, a silicone layer and a fluorocarbon resin layer formed on the silicone layer may be used.

  The coating material 7 is heated on the surface of the metal tube 1 to be thermally contracted. The coating layer subjected to the coating process acts as a protective film for the metal tube 1 and its thickness is constant. Therefore, the spiral patterned shape of the tube 10 does not change even if it is coated. Further, oxidation of the surface of the metal tube 1 is prevented. Further, when the transfer paper is wound around the tube 10, the tube 10 has a function of making the paper easy to peel off and making it difficult to wrinkle.

  In the coating process, it is important that the coated fluororesin is not peeled off from the metal tube 1. In the present embodiment, a roughing spinning process is performed to roughen the surface. This rough surface processing has the two purposes of increasing the residual compressive stress of the metal tube 1 and at the same time providing roughening for preventing the coating layer from peeling off. The step of imparting the rough surface is preferably applied to a stainless steel material, but may be a tube of another metal.

  In this way, the tube 10 having the coating shown in FIG. 1 is finally obtained. This finished product is also called as a fixing roll, a pressure roller, a heating roller, a paper feed roller, a photosensitive drum, or the like. It is. The metal tube 1 referred to in the present embodiment is one obtained by spinning a plate material into a bottomed element tube 2 that has been drawn. The bottomed element tube 2 may be manufactured by a processing method other than drawing, such as turning, grinding, or plating.

  Next, examples of the present embodiment will be described. In this example, it was confirmed that indentations were formed in a spiral pattern on the surface of a metal tube obtained by spinning a bottomed element tube made of a plastically workable metal. Three pieces were arranged at equal intervals of 120 degrees on the outer periphery of the bottomed element tube and subjected to spinning processing. That is, the bottomed element tube was rotated at a predetermined rotational speed, and the spinning was performed by moving the frame at a predetermined moving speed.

  The bottomed tube was subjected to normal spinning and roughing. The bottomed bare tube used in the examples had a large diameter of 30 mm and a length of 54 mm. The material of the bottomed element tube was SUS304 which is an austenitic stainless steel.

  The tops used for spinning are the tops shown in FIG. 6 for normal spinning and the tops shown in FIG. 3 for roughing spinning. After normal spinning and roughing spinning, the surface roughness and thickness of the bottomed tube were measured. The surface roughness was measured using a surface roughness measuring machine manufactured by Tokyo Seimitsu Co., Ltd. The thickness was measured using a micrometer manufactured by Mitutoyo Corporation. These measurements are performed by moving the probe unit at a predetermined speed in a direction parallel to the central axis direction of the metal tube, and the probe unit can be moved by being guided by a highly accurate straightness surface. It is.

[Normal spinning process]
Spinning was performed with three pieces (H42, H34, H44) to obtain a normal bottomed element tube. The surface roughness and thickness of the obtained bottomed bare tube were measured. The measurement results are shown in Table 1 below.

[Spinning for roughing]
When the above normal spinning process was completed, the shape of the third frame was changed and the spinning process was performed. The surface roughness and thickness of the bottomed tube obtained by this roughing spinning process were measured. The measurement results are shown in Table 2 below.

  From the above results, in the case of Table 1, the surface roughness Rz of the bottomed element tube is 1.5 or less. On the other hand, in the case of Table 2, the surface roughness Rz of the bottomed element tube is 3.0 or more. It was possible to add surface roughness to the bottomed tube by spinning the top with a sharp top. 7, 8, 9 and 10 are measurement graphs obtained by measuring the surface roughness of the outer and inner surfaces of the bottomed tube. 7, 8, 9 and 10, the surface shape is displayed at a vertical display magnification: 20000 times (vertical scale: 5 μm / 10 mm) and a horizontal display magnification: 10 times (horizontal scale: 1 mm / 10 mm). Yes.

  That is, the surface shape is displayed by enlarging the vertical direction 200 times compared to the horizontal direction. 7A, 7B and 7C show the measurement results of the outer surface of the bottom of the bottomed element tube. FIGS. 8A, 8B, and 8C are measurement results of the outer surface of the flange portion of the bottomed element tube. 9A, 9B, and 9C are measurement results of the inner surface of the bottom of the bottomed element tube. 10 (a), (b) and (c) are measurement results of the inner surface of the flange portion of the bottomed element tube.

  These graphs are described in the example of FIG. The measurement result of the surface shape in FIG. 7 shows the amount of change in the surface shape curve (cross-sectional curve) of the metal tube at a predetermined measurement length in the center axis direction of the metal tube (displayed in the vertical direction in FIG. 7) Direction indication), that is, bumps on the surface (mountains and valleys on the actual surface) are shown enlarged. The surface of the metal tube is in a state (surface shape) in which indentations are formed that regularly repeat fine irregularities at regular intervals. This indicates that the surface of the metal tube has a surface shape in which a minute spiral-patterned uneven impression is formed.

  That is, it was confirmed that the surface of the metal tube was formed with a minute spiral pattern of unevenness by spinning. Similarly, FIG. 8 shows the measurement result of the flange portion of the metal tube. Similar to FIG. 7, the surface of the metal tube has a surface shape in which indentations that regularly repeat a fine uneven state at regular intervals are formed. In any case, the uneven shape has an uneven surface shape curve (cross-sectional curve), and was about 5 μm when expressed by the dimensional difference between the peaks and valleys of the surface shape curve.

  In the measurement of the inner surface in FIGS. 9 and 10, the peaks and valleys of the surface shape curve are not larger than those in FIGS. 7 and 8, but the peaks and valleys can be confirmed regularly. This fine concavo-convex shape has a great effect when the metal tube is applied as a finished product, for example, to a fixing roller or the like, and particularly the inner surface has a lubrication holding function.

  Next, FIG. 11 shows a measurement example of ten metal tubes. The horizontal axis of the graph in FIG. 11 indicates the length of the metal tube and indicates the position of the measurement location. The vertical axis of the graph in FIG. 11 indicates the surface roughness Rz of the surface of the metal tube. As can be seen from the figure, the normal spinning processed five metal tubes B1 to B5 have a surface roughness Rz of about 1 μm, and after the roughing spinning process, the surface roughness Rz is 3 μm or more. .

  In FIG. 12, the result of having measured the external shape of ten metal tubes of FIG. The horizontal axis of the graph of FIG. 12 indicates the length of the metal tube and indicates the position of the measurement location. The vertical axis | shaft of the graph of FIG. 12 shows the large diameter of the external shape of a metal tube. As can be seen from the figure, the outer shape of the metal tube after the roughing spinning process is slightly thicker than that of the ordinary spinning metal tube.

  In FIG. 13, the result of having measured the surface roughness of the inner surface of ten metal tubes of FIG. 11 is shown. The horizontal axis of the graph in FIG. 13 indicates the length of the metal tube and indicates the position of the measurement location. The vertical axis of the graph in FIG. 13 indicates the surface roughness Ra of the inner surface of the metal tube. As can be seen from the figure, the surface roughness Ra of the metal tube after the spinning process for roughening is larger than that of the normal spinning metal tubes B1 to B5. Is not seen. The surface roughness Ra is almost 0.3 μm or less, and this has no significant effect on the function of the lubricating oil.

  For these metal tubes, bending stress was measured, but no significant difference was found between the metal tube after the normal spinning process and the metal tube after the spinning process for roughening. As mentioned above, although embodiment of this invention was described, this invention is not limited to this embodiment. Needless to say, changes can be made without departing from the scope and spirit of the present invention.

  The present invention can be used in industries such as electrophotographic printers, copying machines, fixing rollers such as photoreceptors thereof, pressure rollers, photosensitive drums, and other printing machines, printing apparatuses, copying machines, and copying apparatuses.

DESCRIPTION OF SYMBOLS 1 ... Metal tube 2 ... Bottomed raw tube 2a ... Bottom part 2b ... Flange 4 ... Rotation basic shaft 4
5 ... Frame (for normal spinning process)
5a ... Top (for roughing spinning)
6 ... Indentation 7 ... Coating material 10 ... Tube

Claims (7)

A hollow metal core with a uniform thickness of 20 to 50 μm, and a metal annular metal original that rotates around the central axis of the metal original together with the rotating support. Let me
As a result of the first spinning process in which the first piece arranged on the outer periphery of the metal original body is pressed and plastically processed, irregularities are formed at substantially constant intervals on the outer peripheral surface and the inner peripheral surface of the metal original body. A metal tube,
After the first spinning process, in order to roughen the outer peripheral surface of the metal tube, a second frame whose tip angle is sharper than the first frame is arranged and pressed on the outer periphery of the metal tube. By carrying out plastic working, minute irregularities are formed at substantially constant intervals on the outer peripheral surface and inner peripheral surface of the metal original body,
The fine uneven portion roughens the outer peripheral surface and inner peripheral surface of the metal tube. The metal tube according to claim 1,
The minute irregularities are minute irregularities having a dimensional difference of 0.3 μm or more between peaks and valleys at substantially constant intervals,
The metal tube, wherein the outer peripheral surface of the metal tube has a surface roughness Rz of 3 μm or more. In the metal tube according to claim 1 or 2,
The metal tube is a tube for a fixing roller or belt used in an electrophotographic printer or copying machine, and the minute irregularities on the inner diameter surface are a reservoir of lubricating oil. A process of attaching a metal original body made of a plastic-workable metal to a rotary support for processing the surface shape of the inner and outer diameter surface shapes with minute irregularities at substantially constant intervals;
While the attached metal original body is rotated around the central axis of the metal original body together with the rotating support body, the first frame is pressed to perform plastic processing, and the thickness of the cylindrical portion of the metal original body is 20 Or a first spinning process for performing a spinning process to reduce the thickness to a uniform thickness of 50 μm and to form a surface having irregularities at regular intervals on the inner and outer diameter surfaces;
After the first spinning process, in order to roughen the outer peripheral surface of the metal tube, the spinning metal body is moved around the central axis of the metal body together with the rotary support. While rotating, the second piece whose tip angle is sharper than the first piece is pressed and plastically processed, and the outer peripheral surface and the inner peripheral surface of the metal original body subjected to the spinning process are minutely spaced at substantially constant intervals. A second spinning process for performing a spinning process with a surface having a rough surface,
After the second spinning step, a method for producing a metal tube comprising a step of cutting both end portions of the metal original body into a tube shape,
The method for producing a metal tube, wherein the surface having the minute uneven portion is a surface having a minute uneven shape indentation. In the manufacturing method of the metal tube of Claim 4,
The minute irregularities are minute irregularities having a dimensional difference of 0.3 μm or more between peaks and valleys at substantially constant intervals,
The outer peripheral surface of the said metal tube is surface roughness Rz is 3 micrometers or more. The manufacturing method of the metal tube characterized by the above-mentioned. In the manufacturing method of the metal tube of Claim 4 or 5,
The material of the said metal original body is stainless steel. The manufacturing method of the metal tube characterized by the above-mentioned. In the manufacturing method of the metal tube of Claim 1 selected from Claims 4 thru | or 6,
The metal tube is a tube for a fixing roller or belt used in an electrophotographic printer or a copying machine, and the minute irregularities on the inner diameter surface are a reservoir of lubricating oil. Method.

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