JP2004243410A - Metal foil tube, and method and device for manufacturing the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a metal foil tube of 10-100 μm thick, and a method and a device for reliably manufacturing the metal foil in a tubular shape even when the metal foil is very thin. <P>SOLUTION: The metal foil tube is formed by welding a metal foil stock W having the thickness t of 10-100 μm. The metal foil stock W is worked to form an overlapping part G, and opposing sides are welded, and a welded portion is finished smoothly. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

  The present invention relates to a novel metal foil tube, a method for manufacturing the same, and a manufacturing apparatus. More specifically, a novel metal foil tube suitable for use in an electrophotographic printer, a laser beam printer (LBP), a copying machine, a toner printing roll such as a facsimile machine, a developing roll, a fixing roll, and a method of manufacturing the same, and The present invention relates to a manufacturing apparatus.

  In current image forming apparatuses such as an electrophotographic printer, a laser beam printer (LBP), a copying machine, and a facsimile, a photosensitive drum is exposed by an image signal, and a toner image is formed by a developing machine. The toner image formed on the recording medium is transferred to a recording sheet, and is further thermally fixed by a fixing device and output. In such an image forming process, various roll members such as the photosensitive drum, the toner printing roll, the developing roll, the pressure roll, and the fixing roll are used. Usually, the roll member is formed in a cylindrical shape or a column shape, and is driven by a driving device (such as a motor).

  A cylindrical metal thin tube that can be used as a toner baking roll, a developing roll, a fixing roll, etc. of an image forming apparatus such as an electrophotographic printer, a laser beam printer (LBP), a copying machine, a facsimile, etc. Due to the metal's high elasticity, high rigidity, high thermal conductivity and ultra-thin technology, the tube surface achieves high rotation accuracy without vibration and rotation unevenness that has a negative effect on lightweight, sharp full-color image quality. There is a demand for a thin metal tube that is entirely smooth and has excellent durability. For this reason, metal thin-walled tubes made by welding stainless steel plates into a cylindrical shape by press working, laser welding, plasma welding, etc., are used as thin-walled tubes. It is processed to an extremely thin thickness by processing, spinning, drawing, bulging, or the like (for example, see Patent Document 1).

In addition, as a metal thin-walled tube that can be used as a toner baking roll, a developing roll, a fixing roll, and the like of an image forming apparatus such as an electrophotographic printer, a laser beam printer (LBP), a copying machine, and a facsimile, a thermoplastic resin is used. (For example, see Patent Literature 2).
JP-A-2002-55557 JP 2000-280339 A

  However, in a thin metal tube made by thinning technology of a base tube (metal thick tube) made by press working, laser welding, plasma welding, etc., the structure of the welded portion is once melted by laser welding or plasma welding. The hardness Hv is reduced to about half, and the strength is also reduced. Further, when the tube is made thinner, the surface thereof is rougher (skin is rough) than a metal rolled material (for example, stainless steel foil). For example, in the case of spinning processing in which processing of about 90% is performed, the surface roughness Rz is The thickness is about 3 μm, and there is a problem that a surface defect occurs due to the thinning. For this reason, there is a problem that it is difficult to sufficiently obtain rotation accuracy such as vibration and rotation unevenness that adversely affect sharp full-color image quality. Further, in such a thinning technique, a manufacturing process is complicated and a manufacturing cost tends to be high.

  Further, in the method of joining the metal thin film sheet end face with a thermoplastic resin, the resin film covering the metal thin film needs to be a thermoplastic resin, and non-thermoplastic or thermosetting polyimide or other resin. Molding is not possible. In addition, compared to metal bonding, resin bonding has low bonding strength and it is difficult to provide long-term durability. Particularly when used at high temperatures, a load applied to the bonding portion causes a problem in the bonding portion. It is unsuitable for a toner baking roll or the like, because thermal embrittlement is observed such as peeling. In addition, it is necessary to uniformly coat the resin on the metal thin film, and there has been a problem that the manufacturing cost is increased.

  Therefore, an object of the present invention is to provide a metal having an extremely smooth surface, high elasticity, high rigidity, and high thermal conductivity without using a press working, a laser welding or a plasma welding method, a thinning technique, and a resin material. A novel thin metal tube having excellent rotation durability, having high rotation accuracy without vibration or rotation unevenness that has an adverse effect on sharp full-color image quality, and having excellent durability, and a method for manufacturing the same, and A manufacturing apparatus is provided.

  The present inventors have conducted intensive studies on a novel metal thin tube, a method for manufacturing the same, and a manufacturing apparatus for achieving the above object, and as a result, a conventional press working, laser welding or plasma welding method + thinning technology, By welding and pressing a metal foil such as a stainless steel foil almost without melting without using a resin material, there is no or very little molten part, so the hardness does not decrease, and the durability is high. A new manufacturing method and a manufacturing apparatus capable of finishing the part smoothly can be found, whereby the manufacturing cost can be remarkably reduced, and the obtained metal foil tube can also be formed using a conventional thinning technique or resin material. High elasticity, high rigidity, high thermal conductivity, ultra-thin and lightweight, and excellent surface smoothness and sharpness Have high rotation accuracy without vibrations or rotational irregularity adversely affect for full color image quality, found that the novel metal foil tube is obtained which is excellent in durability, it has been led to completion of the present invention.

  Furthermore, the present inventors have tried diligently without being satisfied with the novel metal foil tube obtained by the above-described novel production method and the production apparatus, and as a result, have obtained the following knowledge, and have further obtained the present invention. It could be improved.

  That is, generally, the welded portion tends to be slightly irregular in shape with respect to the foil base material, and the surface roughness tends to be large. In the present invention, the metal foil is welded and pressure-welded almost non-melting. For this reason, the welded portion can be finished smoothly, and the shape of the welded portion does not become irregular with respect to the foil base material, and the surface roughness can be reduced. However, in the course of further research and improvement, when using a metal foil with almost no fusion, welding and pressure welding, the use of a soft foil material makes it easier to crush the overlapped part and reduces electrode flaws. On the other hand, it has been found that in many cases, a harder tube material is desirable in order to prolong the high cycle fatigue life from the viewpoint of use performance. Therefore, as a means for solving this inconsistency and further improving the metal foil tube of the present invention, the annealed foil is welded and pressed with almost no melting, followed by swaging, split roller rolling, hole die, and spatula drawing. Fatigue life of metal foil tubes by applying cold working by the method or a combination of these methods to reduce wall thickness, smoothen the welded part, adjust the shape and surface roughness of the welded part, and simultaneously work harden the material Can be lengthened. Here, in a metastable austenitic steel such as SUS301 or SUS304, a martensite phase is generated by cold working, and work hardening is remarkable, and a Vickers hardness of up to about 600 is possible. Even if not so much, high nitrogen stainless steel such as SUS304N1, N2, SUS316N, and SUS836L, and high Mn stainless steel such as SUS201 and 202 also have large work hardening, and a Vickers hardness of up to about 500 is possible. Other ordinary austenitic stainless steels have been found to be possible up to a Vickers hardness of about 430, and have further improved the present invention.

  Further, in the present invention, as a method of welding and pressure welding almost in a non-melting manner, a means for joining metal foils by electric resistance welding such as seam welding or mash seam welding has been found. Seam-welded joints have a stable nugget strength due to the presence of a continuous nugget (melted and solidified part) along the weld line or an intermittent nugget at more than 50% along the weld line It has been found that it is possible to raise the cost. That is, in seam welding in which welding and pressure welding are performed in a substantially unfused state, once a nugget is generated, even if the disk-shaped electrode (see reference numeral 32 in FIG. 6) rotates, much of the current flows through the nugget portion having a small electric resistance. (Reactive current), and only a small amount of current flows at the interface to be newly joined due to high electric resistance. Therefore, this portion is brought into a pressure contact state without reaching the melting temperature. Once the press-contact portion is formed, the electric resistance is also reduced here, so that the nugget is prevented from being generated in the same manner as the nugget. In order to avoid such a vicious cycle, the present inventors perform seam welding using a pulsed power source, provide a relatively long non-energization time after a short energization time, and obtain a continuous nugget by repeating this cycle. succeeded in. In this case, the optimal ratio between the energizing time and the non-energizing time is 1/12 to 1/8, and if it is less than 1/12 or more than 1/8 to 1/6, an intermittent nugget is generated. According to the experiments performed by the present inventors, it has been found that even if the nugget becomes an intermittent one, if the nugget covers 50% or more of the weld line, there is no problem in strength. From the above, in order to obtain a nugget covering 50% or more of the welding length, it is necessary to perform seam welding by setting the ratio of energizing time to non-energizing time to 1/15 to 1/7 using a pulse power source. I knew there was. Based on such findings, the present invention can be further improved.

  On the other hand, in mash seam welding, which can be welded and pressed in a non-molten manner (there is an advantage that the hardness is not reduced because a non-molten portion cannot be formed because a non-molten portion cannot be formed), so that the strength of the welded portion can be increased more stably. It has been found that mash seam welding is preferably performed using a pulse power source, and in this case, there is also an optimum ratio between the energizing time and the non-energizing time. That is, it has been found that in mash seam welding, it is desirable to perform welding by using a pulse power source and setting the ratio of the energizing time to the non-energizing time to 1/3 to 1/1. Based on such findings, the present invention can be further improved.

  Further, the surface of the fixing roll of the printer may be flawed due to foreign matters or the like, and once flaws are formed, there is an adverse effect such as adversely affecting a subsequent printing result.

  Also, in the novel metal foil tube discovered by the present inventors, when seam welding a metal foil, a nugget formed by melting and solidification may not be continuously generated, and this portion has a welding strength in a pressed state. Has been found to be relatively low and there is room for improvement. Therefore, it has been found that it is necessary to improve these points to improve product yield and quality.

  Therefore, a further improvement of the present invention solves these problems as well, and the first is that at least one of the surface and the inner surface of the foil tube formed by joining and forming a metal foil by resistance welding or the like. And a metal foil tube whose surface is hardened by a hard plating layer.

  The second one is the above-mentioned metal foil tube, wherein the composition of the plating layer is mainly one or more metals of chromium, nickel, cobalt, and palladium.

  The third one is the above-mentioned metal foil tube, wherein the composition of the plating layer is a Ni-P-based alloy.

  The fourth one is a group consisting of a group 10-11 element or an alloy containing one or more of these elements, or a metal having a melting point of 1200 ° C. or less, in the vicinity of at least one of the joints on both surfaces of the stainless steel foil. A metal foil tube formed by plating and then resistance welding the foil, and a method for producing the same.

  The fifth one is the above metal foil tube and the method for producing the same, wherein the composition of the plating layer is a Ni-P alloy containing 1 to 14% of P by weight.

  The sixth one is a metal foil tube and a method for producing the same, wherein a stainless steel foil is joined or formed by resistance welding or the like and a foil tube is heat-treated at a temperature of 800 to 1100 ° C.

  The seventh one is a metal obtained by heat-treating a foil tube obtained by joining or further forming a stainless steel foil by resistance welding or the like at a temperature of 800 to 1100 ° C., and then performing hard plating on at least one of the inner and outer surfaces of the foil tube. A foil tube and a method for manufacturing the same.

  The object of the present invention is achieved by the following means.

    (1) A metal foil tube obtained by joining or welding metal foils having a thickness of 10 to 100 μm.

(2) the metal foil is a stainless steel foil,
The metal foil tube according to (1), wherein the material of the stainless steel foil is any one of ferritic stainless steel, martensitic stainless steel, austenitic stainless steel, and precipitation hardening stainless steel. .

    (3) The metal foil tube according to the above (1) or (2), which is joined by electric resistance welding.

    (4) The metal foil tube according to any one of (1) to (3), wherein the electric resistance welding is seam welding.

    (5) The method according to (4), wherein the seam welding is performed by using a pulsed power source and setting the ratio of energizing time to non-energizing time to 1/15 to 1/7. A metal foil tube as described.

    (6) The metal foil tube according to any one of the above (1) to (5), wherein the electric resistance welding is mash seam welding.

    (7) The above-mentioned (6), wherein the mash seam welding is performed by using a pulse power source and setting the ratio of the energizing time to the non-energizing time to 1/3 to 1/1. 2. The metal foil tube according to item 1.

    (8) The metal foil tube according to any one of (1) to (7), wherein at least a part of the bonding surface is solid-phase bonding.

    (9) The metal foil tube according to any one of (1) to (8) above, wherein the joining or the joining line is arranged in a straight line or a spiral shape.

    (10) The above (1) to (9), wherein the absolute value of the hardness difference between the joined or welded portion and the base material portion is not more than 25% of the hardness of the base material portion in Vickers hardness (Hv). The metal foil tube according to any one of the above items.

    (11) The metal foil tube according to any one of the above (1) to (10) is subjected to cold working to reduce the thickness, and the joint or welded portion is smoothed to form the joint or welded portion. Characterized in that the surface roughness is adjusted and the material of at least the joining portion or the welded portion is work-hardened.

(12) the metal foil is a stainless steel foil,
The metal foil tube according to any one of the above (3) to (11), wherein the stainless steel foil is an austenitic stainless steel annealed material.

    (13) The metal foil tube according to any one of the above (1) to (12), wherein the Vickers hardness of the base material portion is 180 or less.

    (14) The metal foil tube according to any one of the above (1) to (12), wherein the material has a Vickers hardness of 300 to 600.

    (15) The metal foil tube according to any one of the above (11) to (14), wherein the maximum nitrogen concentration in the surface layer of the stainless steel foil is 3% by mass or less.

(16) The bulk component is
C: 0.05% by mass or less,
Si: 0.05 to 3.6% by mass,
Mn: 0.05 to 1.0% by mass,
Cr: 15 to 26% by mass,
Ni: 5 to 25% by mass,
Mo: 2.5% by mass or less,
Cu: 2.5% by mass or less,
N: 0.06% by mass or less,
The metal foil tube according to any one of the above (3) to (15), wherein the metal foil tube is a soft austenitic stainless steel containing Fe and unavoidable impurities.

(17) The bulk component is
C: 0.05 to 0.2% by mass,
Si: 0.05 to 3.6% by mass,
Mn: 1.0 to 5.0 mass%,
Cr: 15 to 26% by mass,
Ni: 5 to 25% by mass,
Mo: 5.0% by mass or less,
Cu: 4.0% by mass or less,
N: more than 0.06% by mass to 0.4% by mass,
The metal foil tube according to any one of (3) to (11) above, wherein the metal foil tube is a high-strength austenitic stainless steel containing Fe and unavoidable impurities.

(18) the metal foil is a stainless steel foil,
The metal according to any one of the above (3) to (12), wherein the stainless steel foil is an as-rolled material of a ferritic stainless steel or a martensitic stainless steel, and a martensite phase is precipitated at a welded portion. Foil tube.

    (19) Any one of the above (1) to (18), wherein at least one of the surface and the inner surface of the foil tube to which the metal foil is bonded and formed is hardened by a hard plating layer. 4. A welded metal foil tube according to claim 1.

    (20) The welded metal foil tube according to the above (19), wherein the composition of the plating layer is mainly one or more of chromium, nickel, cobalt, and palladium.

    (21) The welded metal foil tube according to the above (19), wherein the composition of the plating layer is a Ni-P alloy.

    (22) Plating a Group 10 to 11 element or an alloy containing these elements, or a metal having a melting point of 1200 ° C. or less in the vicinity of at least one of the joints on both surfaces of the stainless steel foil. The metal foil tube according to any one of the above (1) to (21), which is formed by welding.

    (23) The welded metal foil tube according to the above (21) or (22), wherein the composition of the plating layer is a Ni-P alloy containing 1 to 14% by weight of P.

    (24) The welded metal foil tube according to any one of the above (1) to (18), wherein the foil tube obtained by joining and forming the stainless steel foil is heat-treated at a temperature of 800 to 1100 ° C.

    (25) The above-mentioned (1), wherein the foil tube obtained by joining or further forming a stainless steel foil is heat-treated at a temperature of 800 to 1100 ° C., and then hard plating is applied to at least one of the inner and outer surfaces of the foil tube. -The welded metal foil tube according to any one of (18).

    (26) The welded portion of the metal foil tube has a continuous nugget (melted and solidified portion) along a weld line or an intermittent nugget at a portion of 50% or more along a weld line. The metal foil tube according to any one of (1) to (25) above.

    (27) The above-mentioned (1), wherein the overlapping margin (x) of the joining portion of the metal foil tube satisfies x ≦ 40 + 5t (unit is μm) as the metal foil thickness (t). -The metal foil tube according to any one of (26).

    (28) The metal according to any one of the above (1) to (27), wherein a ratio of a wall thickness of the tube to an inner diameter of the tube (wall thickness / inner diameter) is 1/500 or less. Foil tube.

    (29) The metal foil tube according to any one of (1) to (28), wherein a surface roughness Rz specified in JIS B0601-2001 (maximum height roughness) is 2.0 μm or less. The metal foil tube according to one.

(30) The metal foil tube has a durability of 1 × 10 ⁶ times or more in a fatigue test in which a strain of 0.2% or less is given to the metal foil tube at a cycle of 60 cycles / min or more. ) The metal foil tube according to any one of (29) to (29).

    (31) The metal foil tube as described in any one of (1) to (30) above, which is used for a toner baking roll and / or a developing roll of an image forming apparatus.

    (32) Production of a metal foil tube having a forming step of forming a metal foil base plate having a thickness of 10 to 100 μm such that a pair of opposed sides are overlapped, and a welding step of welding the overlapped opposed sides. Method.

    (33) The method for producing a metal foil tube according to (32), further comprising a finishing step of finishing the welded portion smoothly.

    (34) The above-mentioned (32) or (33), wherein the forming step includes a positioning step of positioning the metal foil base plate on a forming core bar before overlapping opposing sides of the metal foil base plate. Of manufacturing a metal foil tube.

    (35) In the positioning step, the metal foil base plate is held by a molding device that is always parallel to the core bar and is close to and separated from the core bar. The method for producing a metal foil tube according to the above (34), wherein the metal foil base plate is pressed against the core rod and positioned at the time of line contact.

    (36) In the molding step, after the positioning step, the molding device is further approached toward the core rod, and the metal foil base plate is placed between the core rod and a semicircular recess formed in the molding device. The method for producing a metal foil tube according to the above (34) or (35), further comprising a winding step of holding and winding the metal foil base plate around a core rod.

    (37) The metal according to (36), wherein the forming step includes a lap margin adjustment step of adjusting a lap margin by displacing a part of the circumference of the metal foil base plate in a radial direction after the winding step. Manufacturing method of foil tube.

    (38) The metal foil according to (36) or (37), wherein the overlap margin (x) satisfies x ≦ 40 + 5t (unit is μm) as the plate thickness (t). Tube manufacturing method.

    (39) The method for producing a metal foil tube according to the above (32) or (33), wherein the welding is an electric resistance welding method.

    (40) The method for producing a metal foil tube according to any one of (32) to (39), wherein the electric resistance welding is seam welding or mash seam welding.

    (41) Seam welding is performed by setting the ratio of the energizing time to the non-energizing time to 1/15 to 1/7 using a pulse power source, or the ratio of the energizing time to the non-energizing time using a pulse power source is set to 1/3 to The method for producing a metal foil tube according to the above (40), wherein mash seam welding is performed at a setting of 1/1.

    (42) In the welding, a conductive fixed electrode member provided in a groove formed along the axial direction on the outer surface of the core rod, and a conductive movable member provided opposite to the fixed electrode member. The method for producing a metal foil tube according to any one of the above (32), (33) or (39) to (41), wherein the method is carried out by applying a current to the electrode member.

    (43) The method for producing a metal foil tube according to the above (42), wherein the fixed electrode member is formed such that a part or the whole of an outer surface thereof is flat.

    (44) The method for producing a metal foil tube according to the above (42) or (43), wherein at least a part of each of the fixed electrode member and the movable electrode member is made of molybdenum or an alumina-dispersed copper alloy.

    (45) The metal foil tube according to any one of (42) to (44), wherein in the welding, the hardness of each of the electrode members and the hardness of the metal foil base plate are substantially the same. Production method.

    (46) Any of (34) to (36) above, wherein the metal foil tube is detached from the core rod by ejecting a fluid in a radial direction from inside the core rod and is detached. Or the method for producing a metal foil tube according to (42).

    (47) The above-mentioned (34) to (37), wherein the core rod is constituted by a plurality of members, and a part thereof is moved in the axial direction so that the metal foil tube is separated from the core rod. ) Or the method for producing a metal foil tube according to (42).

    (48) Any of (32) to (47) above, wherein the ratio of the thickness of the metal foil base plate to the inner diameter of the metal foil tube (plate thickness / inner diameter) is 1/500 or less. 3. The method for producing a metal foil tube according to item 1.

    (49) A metal core tube is put into the metal foil tube obtained by the method according to any one of (32) to (48), and further swaging, split roller rolling, hole die, spatula drawing, or any of these methods. The thickness of the joint or weld is smoothened by smoothing the shape and surface roughness of the joint or weld, and the material of at least the joint or weld is work-hardened. A method for producing a metal foil tube.

    (50) Plating a Group 10 to 11 element or an alloy containing these elements, or a metal having a melting point of 1200 ° C. or less, in the vicinity of at least one of the joints or welds on both surfaces of the stainless steel foil. The method for producing a metal foil tube according to any one of the above (32) to (49), wherein the foil is subjected to resistance welding.

    (51) The method for producing a metal foil tube according to any one of the above (32) to (50), wherein the foil tube obtained by joining or further forming a stainless steel foil is heat-treated at a temperature of 800 to 1100 ° C.

    (52) The above-mentioned (32) to (32) to (32) to (32), wherein, after the foil tube to which the stainless steel foil is joined or further processed is heat-treated at a temperature of 800 to 1100 ° C., at least one of the inner and outer surfaces of the foil tube is subjected to hard plating. 51) The method for producing a metal foil tube according to any one of the above items.

    (53) The method for producing a metal foil tube according to the above (50) or (52), wherein the composition of the plating is a Ni-P alloy containing 1 to 14% by weight of P.

    (54) Due to the welding of the metal foil tube, a continuous nugget (melted and solidified portion) along the weld line or an intermittent nugget at a portion of 50% or more along the weld line exists at the welded portion. The method for producing a metal foil tube according to any one of the above (32) to (53), wherein:

    (55) An apparatus for manufacturing a metal foil tube, comprising: a forming part for forming a metal foil sheet having a thickness of 10 to 100 μm into a predetermined shape; and a welding part for welding opposite sides of the metal foil sheet.

(56) The molding unit is provided so as to be able to approach and separate from the core rod having a circular cross section perpendicular to the axis, and a molding device for holding a metal foil base plate. At the time when the metal foil base plate and the core rod are brought into line contact with the rod, a positioning member that presses the metal foil base plate and positions the core foil relative to the core bar,
The above-mentioned (55), wherein the molding device approaches the positioned metal foil base plate toward the core bar, and the metal foil base plate is previously wound in a U-shape around the core bar. An apparatus for manufacturing a metal foil tube according to the above.

(57) The forming device is provided so as to be close to and separated from the core rod while always maintaining a position parallel to the core rod, and a concave part having a semicircular cross section for winding the metal foil base plate in a U-shape with the core rod. A holding plate having a first pressing member that presses one piece of the U-shaped metal foil sheet so as to be in close contact with the outer periphery of the core rod, and the other piece of the U-shaped metal foil sheet. A second pressing member that presses toward the outer periphery of the core rod,
The apparatus for manufacturing a metal foil tube according to the above (56), wherein after the winding, opposite ends of the metal foil base plate are overlapped to form an overlapped portion.

    (58) The forming section may adjust a part of the circumference of the metal foil base plate in the radial direction such that the overlapping margin of the overlapping portion of the opposing sides becomes a predetermined value before the pressing by the second pressing member is completed. The apparatus for manufacturing a metal foil tube according to the above (56) or (57), further comprising an overlap margin adjusting means displaced in a direction.

    (59) The apparatus for manufacturing a metal foil tube according to the above (58), wherein the overlap margin adjusting means is constituted by an eccentric device (such as a cam or a roller) provided inside the core rod.

    (60) The apparatus for manufacturing a metal foil tube according to (58), wherein the overlap margin adjusting means is constituted by an eccentric device (such as a cam or a roller) provided outside the core rod.

    (61) The metal according to the above (58), wherein the overlap margin adjusting means presses a non-contact portion where the metal foil base plate is not in close contact with the core rod by a pressing member. Equipment for manufacturing foil tubes.

    (62) The metal according to (58), wherein the overlap margin adjusting means pushes a pressing member provided outside the core bar toward a concave portion formed in the core bar. Equipment for manufacturing foil tubes.

    (63) The above-mentioned (61), wherein the pressurizing member is any one of a cam, a roll, a cylindrical body, and a rod-shaped member, and is provided at both axial end portions of the core rod so as to be individually operated. ) Or the apparatus for producing a metal foil tube according to (62).

    (64) The metal foil according to (57) or (58), wherein the overlap margin (x) satisfies x ≦ 40 + 5t (unit is μm) as the plate thickness (t). Tube manufacturing equipment.

    (65) The apparatus for manufacturing a metal foil tube according to (55), wherein the welding is an electric resistance welding method.

    (66) The welded portion includes a conductive fixed electrode member provided on the outer surface of the core rod along the axial direction, and a movable electrode member provided opposite to the fixed electrode member. The apparatus for manufacturing a metal foil tube according to the above (55), wherein the welding is performed while the overlapped portion of the metal foil base plate is sandwiched between the electrode members.

    (67) The apparatus for manufacturing a metal foil tube according to (66), wherein the fixed electrode member is formed such that part or all of an outer surface thereof is a flat surface.

    (68) The apparatus for manufacturing a metal foil tube according to (66), wherein the movable electrode member is an electrode wheel that energizes the overlapping portion while pressing the overlapping portion.

    (69) The metal foil tube according to any one of (66) to (68), wherein at least a part of each of the fixed electrode member and the movable electrode member is made of molybdenum or an alumina-dispersed copper alloy. manufacturing device.

    (70) The metal foil tube according to any one of (66) to (68), wherein in the welding, the hardness of each of the electrode members and the hardness of the metal foil base plate are substantially the same. manufacturing device.

    (71) The above-mentioned (56), (57), and (66), wherein the metal foil tube is detached from the core rod by ejecting a fluid in a radial direction from the inside of the core rod to be removed. The apparatus for manufacturing a metal foil tube according to any one of the above items.

    (72) The above-mentioned (56), (57), or (66), wherein the core rod has a fluid passage for ejecting a fluid for peeling the metal foil tube after welding from the core rod. An apparatus for manufacturing a metal foil tube according to the above.

    (73) The core rod according to any one of the above (56), (57), and (66), wherein the core bar has a cutout on an outer peripheral surface of the core bar so that the metal foil base plate does not adhere to the core rod. 3. The apparatus for manufacturing a metal foil tube according to claim 1.

    (74) The above-mentioned (56), (57), wherein the core rod is constituted by a plurality of members, and a part thereof is moved in the axial direction so that the metal foil tube is separated from the core rod. ), The apparatus for producing a metal foil tube according to any one of (66).

    (75) The metal foil tube according to any of (55) to (74), wherein a ratio of a thickness of the metal foil base plate to an inner diameter of the metal foil tube is 1/500 or less. manufacturing device.

    (76) The method is obtained by using the method for producing a metal foil tube according to any one of (32) to (54) or the apparatus for producing a metal foil tube according to any one of (55) to (75). And metal foil tube.

  In the metal foil tube of the present invention, a metal plate is joined into a tube shape (base tube) by press working, laser welding, plasma welding or the like as in the conventional method, and the base tube is thinned using a thinning technique (for example, ironing, Compared to the case of processing into a thin tube by spinning, drawing, bulging, etc.), regarding thinning, the metal plate is rolled, and if necessary, annealed or heat-treated to obtain a metal with a desired thickness. Since foils and tubes can be mass-produced, production costs can be significantly reduced as compared with a case where the thickness of each tube is reduced.

  Also, in the conventional method, when thinning a cylindrical tube made by press working, laser welding, plasma welding, etc., strong mechanical stress is applied to the tube surface. However, in the present invention, a metal foil having excellent surface smoothness can be finished by a rolling process, and the metal foil can be used as it is without performing a thinning process. Therefore, it is advantageous in that excellent surface smoothness can be maintained.

  Furthermore, in the present invention, since the tube is formed by the electric resistance welding method for the metal foil welding, the control is simple and the production of an extremely thin metal foil tube can be favorably performed. For this reason, the hardness difference between the hardness of the joined portion and the hardness of the non-joined portion can be reduced as compared with a thin tube in which a base tube is formed by conventional laser welding and plasma welding and the like, and this is thinned, It is possible to suppress a decrease in durability due to metal fatigue or the like at the boundary between the joined portion and the non-joined portion. Regarding the problem of welding delamination of a welded portion, a thin tube formed by forming a base tube by conventional laser welding, plasma welding, or the like, and reducing the thickness thereof, has a large size of about 90% in the welded portion at the time of thinning. Since processing is added, welding peeling is likely to occur in subsequent use.However, in the present invention, since large processing is not required after welding, it is advantageous in that problems such as welding peeling at the welded portion can be less likely to occur. is there.

  Further, the present invention is advantageous in that any material can be selected as the metal foil depending on the intended use. That is, in the present invention, existing materials from hard materials to soft materials can be used, and the required performances such as high elasticity, high rigidity, light weight, ultra-thinness, and high thermal conductivity are satisfied according to the use application. The material can be appropriately selected.

  Furthermore, in the present invention, by applying hard plating to the inner and outer surfaces of the tube, even if foreign matter is brought in together with the paper, it is possible to suppress flaws on the roller and to suppress adverse effects on the printing result. it can. Also, by performing hard plating, even when nuggets formed by melt-solidification may not be continuously generated during seam welding, the plating layer is melted and complete metal bonding is obtained along the weld line. Therefore, sufficient welding strength can be obtained in this portion in the pressure contact state, and the yield and quality of the product can be improved.

  In the method for manufacturing a metal foil tube of the present invention, even if the metal foil base plate has a thickness of 10 to 100 μm, after forming so as to form an overlapped portion, the opposite sides thereof are welded, and the welded portion is formed. Since it is finished smoothly, even a very thin metal foil can be surely finished in a tubular shape.

  In forming, the metal foil is not rounded at once, but is positioned and wound around a core rod having electrodes, and then, after forming an overlapped portion, welding is performed. Therefore, extremely precise forming can be performed, and welding becomes easy. Since the overlapping portion is also formed while adjusting the overlap margin, more precise molding is possible. If the overlap margin (x) satisfies x ≦ 40 + 5t (unit is μm) as the plate thickness (t), both ends can be welded and connected even with an extremely thin metal foil.

  Since the welding is an electric resistance welding method, the welding is easy to control, and an extremely thin metal foil can be produced satisfactorily. Further, if a fixed electrode member is provided on a core rod serving as an inner mold, and a movable electrode member is provided so as to face the fixed electrode member, and both sides are energized, the both ends of the metal foil can be connected with high precision.

  Since the manufacturing apparatus of the present invention is provided with a forming apparatus that holds a metal foil base plate that can be closely separated from each other around a core rod having a circular cross section perpendicular to the axis, the sheet thickness is 10 to 100 μm. Even if there is, after forming so as to form the overlapped portion, the opposite sides thereof are welded, so that the tube can be surely finished.

  The molding is performed by winding the metal foil base plate around the core rod with a holding plate having a U-shape and a first pressing member and a second pressing member for pressing each piece so as to be in close contact with the outer periphery of the core rod, Since the opposite side edges are overlapped, extremely precise molding can be performed, and subsequent welding is also facilitated.

  Adjustment of the overlap allowance of the overlapping portion is also performed by eccentric devices (such as cams or rollers) provided inside or outside the core rod, by pressing the non-adhesive part of the metal foil base plate, or by pressing the metal toward the recess formed in the core rod. Since the pressing is performed by a pressing member into which the foil base plate is pushed, more precise molding is possible.

  In welding, a fixed electrode member is provided on a core rod serving as an inner mold, and a movable electrode member is provided opposite to the fixed electrode member. Electric current is applied between the two, so that both ends of the metal foil can be accurately connected. In addition, if the movable electrode member is an electrode wheel, smooth and accurate welding can be performed. If the hardness of each electrode member and the hardness of the metal foil base plate are almost the same, accurate welding can be performed in the long term. It becomes.

  If the metal foil tube after molding is ejected in the radial direction from the core rod or by using a separated core rod, the metal foil tube is easily separated from the core rod, and even extremely thin metal foil tubes can be easily removed. It becomes possible.

  Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.

<Metal foil tube>
The present invention is a metal foil tube obtained by joining or welding a metal foil having a thickness of 10 to 100 μm, preferably 20 to 50 μm. In the present invention, by using a novel metal foil tube described below, the metal has high elasticity and high rigidity, which are the characteristics of metal, is extremely thin and lightweight, has excellent durability, and has high thermal conductivity and is sharp. Rolls for toner printing and development of image forming apparatuses such as electrophotographic printers, laser beam printers (LBPs), copiers, and facsimile machines that require high rotational accuracy without vibration or rotational unevenness that adversely affect the full-color image quality A thin metal tube formed by joining or welding a metal foil having a thickness of 10 to 100 μm, which can be applied to a roll or the like, can be obtained. For this reason, in the conventional thinning technology, the surface is inevitably roughened, and it is difficult to make the surface smooth, and a material having a surface roughness Rz of 3 μm or less cannot be obtained. When a metal foil, for example, a rolled stainless steel foil is used by joining or welding, a material having a smooth surface and a surface roughness of 2 μm or less can be provided. As a result, it is possible to provide a metal foil tube having high rotation accuracy without vibration or rotation unevenness which adversely affects sharp full-color image quality. In addition, the conventional method of joining with a thermoplastic resin does not provide sufficient joining strength and is inferior in durability, but in the present invention, since the joining is metal, the joining strength is sufficient and the durability is poor. It has excellent properties. In addition, in the conventional method of joining with a thermoplastic resin, it is necessary to apply the thermoplastic resin to the metal foil surface so as to have a uniform thickness, resulting in high cost. It is not necessary, and is excellent in productivity and can provide a low-cost metal foil tube. Furthermore, low power consumption, excellent mechanical repetitive stress, excellent durability in fatigue tests and the like, long product life, without causing thermal embrittlement even at a high operating temperature range of about 200 to 400 ° C. The present invention can provide a metal foil tube which can be suitably used for a toner baking roll and the like and can use an alloy such as stainless steel. Further, the size and weight of an image forming apparatus such as an electrophotographic printer, a laser beam printer (LBP), a copying machine, a facsimile, and the like can be reduced, and energy can be saved.

  Here, when the thickness (wall thickness) of the metal foil tube of the present invention exceeds 100 μm, heat conduction becomes poor, so that it takes time to start up from the energy saving mode, the weight increases, and the foil becomes thin. Since it becomes difficult to achieve a reduction in thickness and weight by increasing the thickness, there is a possibility that it is not possible to sufficiently meet the demands of users and manufacturers who intend to reduce the size and weight. On the other hand, the smaller the thickness of the stainless steel foil is, the more desirable it is. However, if it is less than 10 μm, the strength and rigidity are low and it is difficult to handle.

  In the present invention, since the metal foil tube is formed by directly joining the metal foils as described above, the surface roughness Rz can be 2 μm or less, preferably 0.1 to 1 μm. This is because, as described above, the metal foil tube can be finished by joining (and further surface finishing) without impairing the surface roughness of the metal foil after rolling. Further, if the surface roughness Rz of the metal foil after rolling is less than 0.1 μm, the cost becomes high. Therefore, it is desirable that the surface roughness Rz of the metal foil be 0.1 μm or more. As a result, a metal foil tube that can be used for a toner baking roll, a developing roll, and the like of an image forming apparatus such as an electrophotographic printer, a laser beam printer (LBP), a copying machine, and a facsimile machine has high elasticity, high rigidity, and extremely high flexibility. An object of the present invention is to provide a thin, light-weight, excellent in durability, and a tube having good surface properties and high rotation accuracy without vibration or rotation unevenness which adversely affects sharp full-color image quality.

  In addition, the measuring method of the said surface roughness Rz can be performed by the measuring method prescribed | regulated to JISB0601-2001 (maximum height roughness), However, It is not limited to this.

  Next, the material used for the metal foil tube of the present invention is not particularly limited, and an optimum material may be appropriately selected according to the intended use, and an electrophotographic printer, a laser beam printer ( LBP), a fixing roll, a developing roll, a heating roll, etc. of an image forming apparatus such as a copying machine, a facsimile, etc., have high elasticity, high rigidity, extremely thin, light weight, excellent durability, and A stainless steel foil is desirable because it can provide a material having high rotation accuracy without vibration or rotation unevenness which has a bad effect on sharp full-color image quality. Specifically, the material is ferritic stainless steel, It is characterized in that it is one of site stainless steel, austenitic stainless steel, and precipitation hardening stainless steel. That. The precipitation hardening stainless steel is joined by electric resistance welding or the like to form a metal foil tube and subjected to finishing treatment such as polishing as in Example 7 described later, and then subjected to finishing treatment such as polishing. Along with, for example, solution heat treatment, if necessary, intermediate treatment, precipitation hardening heat treatment, etc. to perform precipitation hardening and obtain high yield strength, and the hardness of the base metal part and the welded part are almost the same This is advantageous in that the durability can be significantly improved. The optimum conditions for the solution heat treatment, intermediate treatment if necessary, and precipitation hardening heat treatment at this time are elucidated for each stainless steel type.

  In the present invention, a technique for directly joining metal foils has not been established at all.However, depending on the purpose of use, it can be widely used for various materials from soft stainless steel foil to hard stainless steel foil. Thus, it is possible to provide a metal foil tube that can be applied to a wide range of applications without being limited by any material used. However, the material of the metal foil tube of the present invention should not be limited to these, for example, Fe-based superalloy, Ni and Ni alloy, Co and Co alloy, Ti and Ti alloy, Nb and Nb alloy, Zr and a Zr alloy, Ta and a Ta alloy can also be used.

  As a material for the metal foil of the present invention, any one of a ferritic stainless steel, a martensitic stainless steel, an austenitic stainless steel, and a precipitation hardening stainless steel is used as a base plate, and thereafter, rolling is performed. As-rolled material, furthermore, annealed material obtained by performing annealing after rolling, and other materials such as a tension annealing material are suitable, but not limited thereto. Specifically, in addition to the ferritic stainless steel foil specified in JIS 400 series in JIS, SUSXM27 and Tp. Other than ferrite stainless steel such as 409 series, martensitic stainless steel foil specified in JIS in SUS400 series, and austenitic stainless steel foil specified in JIS in SUS200 and 300 series, SUSXM7, SUSXM15J1, Tp . 302B, Tp. An austenitic stainless steel such as 314 series, or a precipitation hardening stainless steel such as SUS630 and SUS631 is used as an original plate, and then as-rolled material obtained by performing rolling, and further subjected to annealing after rolling. Examples of the obtained annealed material and precipitation-treated material.

  Further, in the metal foil tube of the present invention, it is desirable that the metal foil tube is joined by electric resistance welding, and specifically, it is desirable that the electric resistance welding is seam welding, preferably mash seam welding. In the present invention, the surface smoothness is superior to that of the conventional thinning technique. However, in order to achieve such surface smoothness, the surface smoothness between the joint and the base material is required. In addition, it is necessary that the hardness difference between the joint portion and the base material portion be Vickers hardness of 25% or less of the hardness of the base material portion. For this purpose, it is desirable that the joints are joined by electric resistance welding, and specifically, the electric resistance welding is seam welding, preferably mash seam welding. In a metal tube using the above joining means, seam welding, which is a resistance welding method of a joint performed by applying an electrode pressing force, and further welding under a strong pressure with a disk electrode while crushing the joint portion, By adopting mash seam welding, which is a welding method to obtain a joint close to the joint, the foils of the joint can be continuously crushed by moderate electrode pressure to form a joint close to the butt joint. it can. For this reason, the thickness of the welded portion is flattened, and it is not necessary to apply an excessive load to the joint portion between the foils at the time of the subsequent surface finishing, and the smooth finishing after the joining is simple and good. Costs can be reduced. As a result, a smooth surface (joined portion) having a low surface roughness Rz as described above can be obtained.

  Further, in the metal foil tube of the present invention, the welded portion of the metal foil tube has a continuous nugget (melted and solidified portion) along the welding line or an intermittent portion of 50% or more along the welding line. Desirably a nugget is present. This is because when welding is performed by seam welding or the like that can be welded and pressed with almost non-melting, the welded portion is formed along a continuous nugget (melted and solidified portion) along the welding line or along the welding line. This is because the strength of the welded portion can be stably increased by the presence of the intermittent nugget in a portion of 50% or more.

  That is, in normal seam welding, once a nugget is generated, even if the disk-shaped electrode (see reference numeral 32 in FIG. 6) rotates, much of the current flows through the nugget portion having a small electric resistance (reactive current), Only a small amount of current flows at the interface to be newly joined due to high electric resistance. Therefore, this portion is brought into a pressure contact state without reaching the melting temperature. Once the press-contact portion is formed, the electric resistance is also reduced here, so that the nugget is prevented from being generated in the same manner as the nugget. In order to avoid such a vicious cycle, the present inventors perform seam welding using a pulsed power source, provide a relatively long non-energization time after a short energization time, and obtain a continuous nugget by repeating this cycle. succeeded in. In this case, the optimal ratio between the energizing time and the non-energizing time is 1/12 to 1/8, and if it is less than 1/12 or more than 1/8 to 1/6, an intermittent nugget is generated. According to the experiments of the present inventors, it has been found that even if it becomes an intermittent nugget, if the nugget covers 50% or more of the welding line, there is no problem in strength. In order to obtain a nugget covering 50% or more of the welding length, it is necessary to set the ratio of the energizing time to the non-energizing time to 1/15 to 1/7. In view of the above, it can be said that the metal foil tube of the present invention is desirably formed by seam welding using a pulse power source and setting the ratio of the energizing time to the non-energizing time to 1/15 to 1/7.

  Furthermore, in mash seam welding which can be welded and welded in a non-molten manner (there is an advantage that the hardness is not reduced because the molten portion cannot be formed due to the non-molten state), so that the strength of the welded portion can be increased more stably. It has been found that mash seam welding is preferably performed using a pulse power source, and in this case, there is also an optimum ratio between the energizing time and the non-energizing time. That is, in the metal foil tube of the present invention, one obtained by mash seam welding using a pulse power source and setting the ratio of the energizing time to the non-energizing time to 1/3 to 1/1 can be said to be one of the desirable modes.

  In addition, since the welded portion according to the present invention is in a solid-state joining state in which no molten phase remains except for a portion of a nugget generated along a joining surface, the molten phase remains over the entire thickness of the welded portion, such as laser welding or plasma welding. As compared with the above, it is possible to suppress a decrease in strength due to a composition change (crystal structure change) at the junction. For this reason, when the metal foil tube is used for a toner baking roll or a developing roll of an image forming apparatus, mechanical properties such as hardness at the bonded portion and the non-bonded portion (base material portion) are substantially equal. Therefore, cracks and bond separation due to sudden metal fatigue due to stress concentration at the boundary portion and the joint surface between the joint and the base material are less likely to occur, and the durability is excellent, and a long life can be achieved. . However, when the material to be used is a soft material, it is possible to reduce the pressure difference at the time of welding to leave a molten phase in the welded portion and to reduce the difference in hardness from the base material. From the above, it can be said that it is desirable that at least a part of the joint surface of the welded portion according to the present invention is solid-phase joining. In this case, the bonding surface may be a part of the bonding surface or the whole may be the solid-phase bonding. In addition, if mash seam welding that can be welded and pressure-welded in a non-melting manner is used, it is possible to perform solid-state welding on all the joining surfaces of the welded portion without generating a nugget. Since a molten phase is not formed, it is desirable in that there is no reduction in strength due to a change in composition (change in crystal structure) at the joint.

  By welding and pressure welding substantially non-molten by the above-described electric resistance welding (including seam welding and mash seam welding), the overlap margin (x) of the joint is x ≦ 40 + 5t as the foil thickness (t) of the metal foil. Is preferable. Here, when the overlap margin (x) is larger than 40 + 5t, the surface finishing processing may be further performed. Here, the unit of the overlap margin (x) and the thickness of the metal foil (t) are both μm.

  In the metal foil tube of the present invention, the absolute value of the hardness difference between the welded portion and the base material portion (non-welded portion) is set to be 25% or less of the hardness of the base material portion in Vickers hardness (Hv). Is also desirable. If the absolute value of the hardness difference between the welded portion and the base material portion (non-welded portion) exceeds 25% of the hardness of the base material portion in Vickers hardness (Hv), the welded portion and the base material portion (non-welded portion) At the boundary of the metal part, the metallurgical notch effect due to the hardness difference easily causes cracks and cracks due to metal fatigue and the like. Further, in the conventional laser welding method, the welded portion is melted and the hardness remains low. The Vickers hardness (Hv) is measured according to JIS Z 2244 (1998). In the present invention, the hardness difference between the welded portion and the base material portion (non-welded portion) can be suppressed by appropriately selecting the welding method, the material, and the heat treatment method, and the durability of the entire metal foil tube can be increased. It is possible to realize high rotation accuracy without rotation unevenness and vibration due to mechanical strength (hardness difference).

In the present invention, as the stainless steel foil, a rolled material of ferritic stainless steel or martensitic stainless steel, in which a martensite phase is precipitated at a weld portion, can be suitably used. Specifically, ferritic stainless steels such as SUS410L and martensitic stainless steels such as SUS403, 410, 420, 431, and 440 can be exemplified as those in which a martensitic phase is precipitated at a welded portion. In the case of these steels, the weld is hardened by precipitation of martensite due to welding heat, and the base metal is hardened using work hardening by rolling to reduce the difference in hardness between the weld and the base metal. it can.
In addition, the hardness of martensitic stainless steel can be selected from a range of Hv 300 to 600 by performing a heat treatment at an appropriate temperature after welding.
A metal foil tube using a hard material as such a stainless steel foil can be suitably used, for example, for applications having a thickness of 30 μm or less. In particular, when the above hard material is used as the stainless steel foil, the mechanical properties of the welded portion can be enhanced. Therefore, the fatigue life can be prolonged, which can contribute to the improvement of durability. Further, the rise time from the power saving mode can be shortened.

  Further, in the present invention, an annealed material obtained by rolling and annealing an austenitic stainless steel specified in the 300 series of SUS specified by JIS such as SUS304. In a metal foil tube using a soft material as such a stainless steel foil, the welded portion is not so hardened and the base material portion is a soft material, so that a soft tube can be obtained as a whole. In this case, by using an electrode material having substantially the same hardness as the metal foil, it is possible to join both the electrode material and the metal foil without damaging them. In particular, when an austenitic stainless steel annealed material is used for the metal foil, it is advantageous in that a material having excellent electrical conductivity such as copper can be combined with the electrode material.

  When the austenitic stainless steel annealed material is used as the metal foil, it is preferable that the base material has a Vickers hardness (Hv) of 180 points or less. This has characteristics such as excellent workability in the production stage and easy molding into a tube. Also, when the metal foil is cut out (punched out) with high precision, the warpage is excellent in that the distortion of the peripheral portion hardly occurs. In addition, there is an electrode material having almost the same hardness as the metal foil, for example, molybdenum, alumina-dispersed copper alloy, etc., and since such an electrode material can be used, it is possible to suppress damage to the electrode material or the tube at the manufacturing stage. You can also.

  In the metal foil tube, the Vickers hardness (Hv) of the material is 300 to 600 points, preferably 400 to 500 points, from the viewpoint of excellent durability and abrasion resistance and prolonging the high cycle fatigue life. . That is, the Vickers hardness of the base material is desirably 180 points or less from the viewpoint of excellent workability at the manufacturing stage and easy formation into a tube. However, from the viewpoint of use performance, it is often desirable that the material of the tube be hard in order to prolong the high cycle fatigue life. Therefore, the metal foil tube obtained by joining or welding the metal foils is further subjected to cold working to reduce the wall thickness, smooth the joints, adjust the shape and surface roughness of the joints, and at least adjust the joints. The material of the part may be work hardened. As a result, the Vickers hardness (Hv) of the material including the joint can be increased to the range specified above, and the durability and abrasion resistance can be enhanced as the use performance. As a result, both workability at the welding stage and high cycle fatigue life from the viewpoint of service performance can be achieved at the same time.

  In the present invention, the entirety including the welded portion of the metal foil tube is processed to reduce the wall thickness, the welded portion is smoothed to adjust the shape and surface roughness of the welded portion, and the entire tube including the welded portion is provided. May be characterized in that the material is work-hardened. This is because, as described above, in the case of welding and pressure welding almost in a non-molten state as in the present invention, the use of a soft foil material makes it easier to crush the two-layered portion and reduces electrode flaws. From the viewpoint of use performance, it is often desirable that the tube material be hard in order to prolong the high cycle fatigue life. In a further refinement of the invention to resolve this inconsistency, the annealed foil is welded and then cold worked by swaging, split roller rolling, hole dies, spatula drawing or a combination of these methods. In this case, the thickness of the welded portion is smoothed, the shape of the welded portion and the surface roughness are adjusted, and the material is work-hardened at the same time. Thereby, the fatigue life of the metal foil tube can be extended.

  That is, as the metal foil tube suitable for the above-mentioned processing method, it is desirable to weld an annealed foil as described above, but this does not exclude the use of an unannealed foil. . That is, the metal foil tube obtained by joining or welding the metal foil is subjected to cold working to reduce the wall thickness, smooth the welded part, adjust the shape and surface roughness of the welded part, and simultaneously work harden the material. As long as the fatigue life of the metal foil tube can be prolonged by doing so, it is included in the above-mentioned technical scope of the present invention, even if it is formed by welding unannealed foil.

  As a processing method of the welded portion of the metal foil tube, for example, cold working by swaging, split roller rolling method, hole die method, spatula drawing method, or a combination of these methods can be performed. However, in the present invention, the method is limited to these cold working methods as long as the shape and the surface roughness of the welded part can be adjusted by smoothing the welded part and at least the material of the welded part can be work-hardened. It should not be.

  It is desirable that the weld is smoothened by performing cold working by the above-described processing method so that the weld is visually indistinguishable from the base material in shape, surface roughness and hardness. As a result, it is possible to achieve a high rotation accuracy without vibration or rotation unevenness that adversely affects sharp full-color image quality, and to provide a metal foil tube having a smooth tube surface and excellent durability.

  Similarly, by smoothing the welded portion, the surface roughness becomes 2.0 μm or less, preferably 0.1 to 1 μm, in the surface roughness Rz defined by JIS B0601-2001 (maximum height roughness). It is desirable to arrange as follows. In particular, the cold working by the working method is suitable for adjusting the surface roughness, and can be adjusted to a value close to the lower limit of the preferred range (see Table 1 in Example 9 described later). It is extremely effective in that respect.

  In addition, by performing cold working and work hardening the material, the Vickers hardness (Hv) of the material is adjusted to 300 to 600 points, preferably 400 to 600 points, more preferably 450 to 550 points. Is desirable. Accordingly, as described above, welding having excellent durability and abrasion resistance, which can be used as a toner baking roll or a developing roll of an image forming apparatus, and having an effective hardness for extending a long cycle fatigue life. A metal foil tube can be provided.

Further, when the austenitic stainless steel annealing material is used as the metal foil, when cutting (punching) the metal foil with high accuracy, wrinkles and cracks are not generated. It is desirable that the content of the nitrogen element in the (bulk) is 0.06% by mass or less, more preferably 0.03% by mass or less. At the same time, the maximum nitrogen concentration in the surface layer of the stainless steel foil is desirably 3% by mass or less. Here, the surface layer of the stainless steel foil means an oxide film formed on the surface by annealing. In general, the oxide film indicates a portion from the outermost layer to a depth from the peak of the oxygen concentration to 50%. When the nitrogen content of the stainless steel foil exceeds 0.06% by mass, the stainless steel foil becomes hard, so that the metal foil may be easily cracked (cut out) when it is cut out (punched) with high precision, and cracks may easily occur. This is because in a normal stainless steel sheet or a rolled stainless steel foil, the nitrogen content does not increase remarkably, but when annealing is performed at the manufacturing stage, N ₂ gas in the atmosphere is taken into the stainless steel foil, Significant nitridation occurs. Therefore, at the same time as the nitrogen content in the bulk increases, the nitrogen content in the surface oxide film also increases significantly. Since the nitrogen content of the surface layer portion is relatively increased with respect to the inside of the bulk, the hardness becomes higher than that of the inside of the bulk. As a result, when the metal foil is cut out (punched out) with high precision, it can be said that a shallow crack is generated in the surface layer portion, which proceeds in the thickness direction and leads to cracking.

  When the austenitic stainless steel annealing material is used as the metal foil, specifically, in the SUS series, the material is SUS304, SUS304L, SUS304J1 (with Cu added), SUS304J2 (17Cr-7Ni-4Mn-). 2US), SUS316L (Mo addition), SUS316L (Mo addition), SUS305, SUSXM7 (Cu addition), SUS317, SUS317L, SUS309S, etc., and YUS304UL, YUS316UL (Mo addition) Stainless steels such as YUS27A (added with Cu), YUS11OM (added with Cu, Si, and Mo), and YUS170 are used as base plates, and then rolled and annealed. Then There. Most widely used as stainless steel, it has already been marketed stably and inexpensively as a stainless steel sheet used for rolling, and the technology for processing into stainless steel foil by rolling has been established, and it is also suitable for annealing. It can be said that a material obtained by using the above-mentioned stainless steel such as SUS316 or SUS304 as a base plate, followed by rolling and annealing is more preferable. In particular, those using SUS304J1 (17Cr-7Ni-2Cu) and SUS304J2 (17Cr-7Ni-4Mn-2Cu) as base plates have a large effect of improving formability and aging cracking by reducing C and N and adding Cu. The moldability is the highest among those exemplified above. Further, those using an austenite stable system such as SUS316 or SUS305 as a base plate do not generate work-induced martensite and have no danger of aging cracking. In addition, SUS316Ti and SUS321 of Ti addition steel, SUS310S (25Cr-20Ni) of high Ni steel, SUS317J5L (21Cr-24Ni-4.5Mo-1.5Cu-low C), SUS384 (16Cr-18Ni), SUSXM15J1 (18Cr- 13Ni-4Si) and the like can also be used as a toner printing roll and a developing roll of an image forming apparatus such as an electrophotographic printer, a laser beam printer (LBP), a copying machine, and a facsimile.

  When a soft austenitic stainless steel (soft material) or a high-strength austenitic stainless steel (hard material) such as the austenitic stainless steel annealing material is used as the metal foil, preferred components of the stainless steel are used. The range is as follows.

  C: C is an austenite stabilizing element, but when it is higher, the material becomes harder. Therefore, when obtaining a soft material, the content is 0.05% by mass or less, and when obtaining a hard material, 0.05 to 0.2% by mass. %.

  Si: Si needs to be 0.05% by mass or more for deoxidation. Further, although it works effectively on oxidation resistance, it is a strong ferrite-forming element. If it exceeds 3.6% by mass, workability is impaired and descaling during hot rolling becomes difficult, so the upper limit is 3.6. % By mass.

  Mn: Mn is effective as an austenite stabilizing element, and is added to fix S and improve hot workability. However, when the content is less than 0.05% by mass, the effect is poor. On the other hand, when the content exceeds 1.0% by mass, the material becomes hard. When a hard material is obtained, the mass is 1.0 to 5.0 mass.

  Cr: Cr is a basic component of stainless steel, and requires at least 15% by mass to obtain excellent corrosion resistance. On the other hand, if it exceeds 26% by mass, the steel becomes brittle and the workability deteriorates, so the upper limit was made 26% by mass. A preferred range is 17 to 19% by mass.

  Ni: Ni is one of the basic components of austenitic stainless steel. It is an element effective for workability and corrosion resistance, and is added in an amount of 5% by mass or more. However, these effects reach saturation even when they are added in excess of 25% by mass or more, so that it is desirable to set the content in the range of 5 to 25% by mass.

  Mo: Mo is an element for improving corrosion resistance, and is added as necessary. However, if the content exceeds 2.5% by mass, the steel hardens, and if it exceeds 5.0% by mass, the steel becomes brittle. Therefore, when obtaining a soft material, the upper limit is set to 2.5% by mass, When obtaining, the upper limit was set to 5.0% by mass.

  Cu: Cu is an element that stabilizes austenite and improves workability and corrosion resistance, and is added as necessary. However, the effect reaches saturation even if the content exceeds 2.5% by mass in the case of the soft material and exceeds 4.0% by mass in the case of the hard material, so that when the soft material is obtained, the upper limit is 2.5% by mass. When a hard material is obtained, the upper limit is set to 4.0% by mass.

  N: N is a strong austenite stabilizing element and an element that improves corrosion resistance, and is added at 0.005% by mass or more. If the soft material content exceeds 0.06% by mass, the workability (high-precision cutting or punching workability) of the foil material after bright annealing is deteriorated, and cracks and cracks are likely to occur. On the other hand, if the content is less than 0.06% by mass, it is difficult to obtain sufficient strength for a hard material, and if the content exceeds 0.4% by mass, the workability of the foil material (high-precision cutting or punching workability). Deteriorates and cracks and cracks easily occur. From the above, when obtaining a soft material, the content is 0.06% by mass or less, more preferably in the range of 0.007 to 0.03% by mass, and when obtaining a hard material, more than 0.06% by mass to 0. 4% by mass.

  Further, the stainless steel may contain Ti, Ca, or the like as an added trace element.

  In addition, the stainless steel has the above components (including the added trace elements) in the above-mentioned range (the amount of the added trace elements is appropriate (usually, Ti: 0.2% by mass or less, Ca: 0%) depending on the purpose of use. .0050% by mass or less) as long as it is contained, and there is no particular limitation), with the balance being Fe and unavoidable impurities. Examples of the unavoidable impurity elements include P, S, Al, and O. The amount of inevitable impurities is usually P: 0.045% by mass or less, Al: 0.05% by mass or less, S: 0.030% by mass or less, and O: 0.01% by mass or less.

  Further, the metal foil tube of the present invention is characterized in that at least one of the surface and the inner surface of the foil tube obtained by joining and forming the metal foil by resistance welding or the like is surface hardened by a hard plating layer. is there. Hereinafter, the metal foil tube in which the surface and the inner surface of the foil tube of the present invention are hardened by a hard plating layer will be described in detail.

  In some cases, foreign matter is brought into the fixing roll of the printer together with the paper, and the roller is scratched, which may adversely affect the printing result. Therefore, the surface hardness of the roller is desirably 400 or more in Vickers. If less processing is performed after welding, this can be achieved by applying hard plating to the inner and outer surfaces of the foil tube. As a metal to be plated, a metal mainly composed of a metal such as chromium, nickel, cobalt and palladium can be used, and it is effective to add a small amount of an additive such as P in order to cure these metals. In the case of plating a Ni-P alloy, the concentration of P is desirably 1 to 14% by weight. The reason is that if it is less than 1%, the effect of hardening is small, and if it is more than 14%, the plating layer is brittle and cracks easily occur. Electroless plating or electroplating is possible as a plating method, but electroless plating is convenient for plating the inside (inner surface) of the foil tube. The present invention is not limited to the case where a hard plating layer is provided on both the surface and the inner surface of the foil tube as described above, and a hard plating layer may be provided on only one of the surfaces. That is, when used for a toner baking roll, a developing roll, a fixing roll, or the like, it is effective to cure the surface (outer surface) of the foil tube in contact with the photosensitive drum or other rolls or paper. is there. On the other hand, a heater may be installed in the roll. In such a case, it is effective to harden the inner surface of the foil tube. In this way, a hard plating layer may be provided on the inner and / or outer surfaces of the foil tube according to the intended use of the metal foil tube.

  Further, the metal foil tube of the present invention is characterized in that a stainless steel foil is joined to the foil tube by resistance welding or the like and further subjected to a heat treatment at a temperature of 800 to 1100 ° C.

  When seam welding stainless steel, since the surface passivation film of stainless steel is strong, in order to completely break these and obtain a strong metal bond over the entire length of the welding line, the current, voltage, welding speed, It is necessary to carefully examine the energization ratio and the like, and to perform welding within a considerably narrow range of welding conditions. In particular, in the case of mash seam welding in which two stacked foils are completely crushed to have a single thickness, the current density to a portion where the end faces of the foils are embedded is low. For this reason, the joint strength of this part is insufficient, and when it is repeatedly processed, an opening may be formed along the joint line. The present inventors have found that two methods are effective in solving this problem.

  One of them is to heat-treat a foil tube formed by joining or further forming a stainless steel foil by resistance welding or the like to diffusely join a joining line to reinforce strength. In this case, the heat treatment is preferably performed in a vacuum heat treatment or in an inert atmosphere. The heat treatment temperature is preferably from 800 to 1100 ° C. If the stainless steel is ferritic or martensitic, a lower temperature may be used, and if the stainless steel is austenitic, a higher temperature is required. On the other hand, when the temperature is lower than 800 ° C., diffusion bonding is not sufficiently performed, and when the temperature is higher than 1100 ° C., deformation is large during heat treatment, and crystal grains are undesirably coarsened. Further, the heat stress around the welded portion is released by the heat treatment, and there is also an effect of eliminating the rough feeling often seen around the welded portion. Further, when the above-mentioned hard plating is performed after the heat treatment, even small irregularities of the welded portion are hidden, so that the position of the welded portion cannot be recognized. Therefore, as the metal foil tube of the present invention, after the foil tube obtained by joining or further forming a stainless steel foil by resistance welding or the like is heat-treated at a temperature of 800 to 1100 ° C., at least one of the inner and outer surfaces of the foil tube is subjected to hard plating. It can be said that the following is desirable. Since the hard plating is as described above, the description is omitted here.

  The second method is that a metal foil before welding is previously formed with a Group 10 to 11 element such as Au, Ag, Cu, Ni or an alloy containing these elements (for example, a Ni-P alloy or the like), or Al In this method, a metal foil having a melting point of 1200 ° C. or less is plated in advance, and this is resistance-welded to obtain a metal foil tube. In this method, even if the bonding line does not reach the melting point of the metal foil such as stainless steel, if the melting point of the plating layer is exceeded, the plating layer is melted, and the passivation film on the surface of the metal foil such as stainless steel is accompanied. The part is pushed out of the joint along the joint line. Thus, a perfect metal bond is obtained along the weld line. Further, small grooves may be formed in the portion where the end face of the foil is embedded, but there is also an advantage that the plated molten metal is also buried in this portion so that a notch does not occur in the joint. Therefore, as the metal foil tube of the present invention, a Group 10 to 11 element such as Au, Ag, Cu, Ni, or an alloy containing one or more of these elements near at least one of the joints on both surfaces of the metal foil (For example, a Ni-P alloy or the like) or a metal (including an alloy) having a melting point lower than the melting point of a metal foil such as Al, preferably a metal (including an alloy) having a melting point of 1200 ° C. or less, Then, it can be said that the foil formed by resistance welding is desirable.

  In the metal foil tube of the present invention, the ratio of the wall thickness of the tube to the inner diameter of the tube (wall thickness / inner diameter) is desirably 1/300 or less, preferably 1/500 or less. The thickness and the inner diameter of the tube here have an allowable range error, so that an average value at a plurality of locations (for example, about 5 to 10 locations) is used.

  The inner diameter of the metal foil tube is not particularly limited and may be appropriately determined according to the intended use. For example, an electrophotographic printer, a laser beam printer (LBP), a copying machine, a facsimile, and the like may be used. Since there is a strong demand for downsizing and weight reduction of the toner baking roll and the developing roll of the image forming apparatus, any roll that can cope with an inner diameter of 50 mm or less currently used may be used. In particular, the manufacturing method and the manufacturing apparatus of the present invention described below can sufficiently cope with such a demand for miniaturization, and the miniaturization increases the curvature of the tube, thereby improving the workability when forming the tube. Even in the case where it is required, it is possible to sufficiently cope with a small diameter of about 10 to 15 mm by using an austenitic stainless steel annealing material among the above-mentioned stainless steel foils.

  Similarly, the length of the metal foil tube is not particularly limited, and may be appropriately determined according to the intended use. Examples thereof include an electrophotographic printer, a laser beam printer (LBP), a copying machine, and a facsimile. Since there is a strong demand for reduction in size and weight, the rolls for baking toner and developing rolls of image forming apparatuses such as those described above may be any rolls that can cope with the currently used length of 500 mm or less. In particular, the manufacturing method and the manufacturing apparatus of the present invention described below can sufficiently cope with such a demand for miniaturization. As the size is reduced, the contribution of the tolerance to the accuracy occupied increases, but in the present invention, by using the austenitic stainless steel annealing material, distortion or the like when cutting (punching) to a predetermined size is less likely to occur. Therefore, the dimensional accuracy of punching can be made extremely high, and it is possible to sufficiently cope with short cylinders.

The metal foil tube of the present invention has a durability of 1 × 10 ⁶ times or more, more preferably 2 × 10 ⁶ times or more, in a fatigue test in which a strain of 0.2% or less is given at a cycle of 60 cycles / min or more. It is desirable to have In the present invention, when it is used for a toner baking roll or a developing roll of an image forming apparatus such as an electrophotographic printer, a laser beam printer (LBP), a copying machine, a facsimile, etc. The specified test is generally performed, and if the durability in that case is about 1 to 2 million times or more, it can have extremely high durability sufficiently exceeding the durability of currently required parts. is there. If the result of the fatigue test of the metal foil tube is less than 1 to 2,000,000 times, the durability of the existing thin metal tube cannot be remarkably improved. The term “durability” as used herein refers to a condition where there is no abnormality such as cracks in the surface properties and no abnormality such as peeling of the joint is observed at the joint portion. If it is found, it shall not have durability. However, in the present invention, depending on the intended use, the metal foil tube may be sufficiently usable if the fatigue test result is 500,000 times or more.

  The use of the metal foil tube of the present invention is not particularly limited. For example, the metal foil tube may be used for an image forming apparatus such as an electrophotographic printer, a laser beam printer (LBP), a copying machine (copier), and a facsimile. It can be used for a toner baking roll, a developing roll, and the like, but is not limited thereto.

<Metal foil tube manufacturing equipment>
Next, an apparatus for manufacturing a metal foil tube according to the present embodiment will be described. FIG. 1A is a plan view of a metal foil base plate to be formed into a metal foil tube, FIG. 1B is a cross-sectional view of the metal foil tube before welding, and FIG. FIG. 1 (D) is a perspective view of a metal foil tube obtained by welding such that the joining portion has a spiral shape. 2 is a schematic side view of a metal foil tube manufacturing apparatus according to an embodiment of the present invention, FIG. 3 is a plan view of FIG. 2, and FIG. 4 is a cross-sectional view taken along line 4-4 of FIG.

As shown in FIGS. 1A and 1B, the metal foil base plate W used in the present embodiment has a rectangular overall shape. For example, the length S ₁ is about ₁ m, the width S ₂ is about 100 mm, and the like. However, the plate thickness t is as thin as 10 to 100 μm. In the present embodiment, the metal foil base plate W is rounded into a circular cross section, the opposite side ends are overlapped, the overlapped portion G is welded, and the metal foil tube P is formed. This metal foil tube P can be applied to various devices including a fixing roll of a copying machine, for example.

  The apparatus for manufacturing a metal foil tube according to the present embodiment roughly includes a molded part 10 and a welded part 30. The forming unit 10 does not roll the rectangular metal foil blank W at once into a cylindrical shape, but gradually contacts the core rod 13 corresponding to the inner mold with the forming device 15 corresponding to the outer mold. And the welding portion 30 welds the overlapped portion G at the end of the opposite side of the metal foil base plate W.

  First, the molding unit 10 will be described. In FIGS. 2 and 3, a forming part 10 includes a columnar core rod 13 cantilevered by a support part 12 erected on a base 11 and a lower part of the core rod 13. And a positioning member 16 for positioning the metal foil base plate W with respect to the core rod 13.

Core rod 13 is somewhat longer than the longitudinal length S ₁ of the metal foil element plate W, the thickness is in the width direction of the metal foil workpiece W length S ₂ is the degree to which one revolution, the core rod 13 will be described later in detail.

As shown in FIG. 4, the molding device 15 includes a positioning member 16, a holding plate 17, a first pressing member 18, and a second pressing member 19. The positioning member 16 is a member for positioning the center of substantially W and the center of the lower surface of the core rod 13. Holding plate 17 is located in the lower core rod 13, so as to close spaced kept always parallel state with the core rod 13 is coupled with the cylinder C ₁ provided on the base 11. The holding plate 17 has a flat upper surface, and a semicircular concave portion 20 formed in the center so that the core rod 13 can be fitted. The concave portion 20 and the core rod 13 are united to form a metal foil base plate. W is deformed and wound around the lower surface of the core rod 13 in a U-shape.

The first pressing member 18 presses the piece of the metal foil base plate W deformed into a U-shape, which is in the state of being erected on the side surface of the core rod 13, against the outer periphery of the core rod 13 to make close contact. As shown in FIG. 4, the first pressing member 18 is located on the holding plate 17 to the left of the core rod 13, and comes close to and away from the axis of the core rod 13 by the cylinder C _2. ing.

The second pressing member 19 also has a configuration similar to that of the first pressing member 18, is provided at a position symmetrical to the first pressing member 18 about the core rod 13, and is separated from the core rod 13 by the cylinder C _3. Thus, the other piece of the U-shaped metal foil plate W is pressed toward the outer periphery of the core rod 13.

  With the cooperation of the positioning member 16, the holding plate 17, the first pressing member 18, and the second pressing member 19, the metal foil base plate W is wound around the outer peripheral surface of the core bar 13, and the metal foil base plate is An overlapped portion G is formed in which opposite ends of W, that is, both ends in the width direction are overlapped.

  The carrying of the metal foil blank W onto the holding plate 17 of the forming device 15 is performed by a suitable transporting means (not shown) such as a negative pressure suction means.

The positioning member 16 is a rod that is inserted through a through-hole 21 formed in a semicircular recess 20 formed in the center of the molding device 15. located in the tip portion, it is provided so as to be close to or away from the lower surface of the core rod 13 by the cylinder C _4, respectively.

  The positioning member 16 abuts on the lower surface of the core rod 13 during this approach, and presses the metal foil base plate W to hold the metal foil base plate W in a fixed position. The timing at which the positioning member 16 operates is when the metal foil base plate W placed on the upper surface of the holding plate 17 is pushed up by the upward movement of the holding plate 17 and comes into line contact with the core rod 13.

  However, even if the positioning is performed by the positioning member 16, the overlapping portion G having a uniform width from the lower end to the tip of the core rod 13 is not always formed. Therefore, the forming section 10 of the present embodiment is provided with the overlap margin adjusting means 22 (see FIG. 5) for adjusting the overlap margin x (see FIG. 1B) of the overlapping section G. Here, FIG. 5 is an enlarged sectional view of a main part in FIG.

  The overlap margin adjusting means 22 sets the metal foil base plate W such that the overlap margin x of the overlapped portion G between the opposing sides becomes a predetermined value, for example, about 0.1 mm before the pressing by the second pressing member 19 is completed. A part of the circumference of is displaced in the radial (radial) direction.

More specifically, as shown in FIG. 5, the overlap margin adjusting means 22 provides an eccentric device (such as a cam or a roller) 23 inside the core rod 13 at least at the base end and the distal end of the core rod 13. the eccentric device (such as a cam or roller) 23 a driving device such as a motor driven by M _1, is obtained so as to displace the portion of the circumference of the metal foil material plate W in the radial direction.

  The amount of rotation of the eccentric device (cam or roller, etc.) 23 is controlled by a signal from the control unit 24 so that the overlap margin x becomes a predetermined value. The control unit 24 includes a detection device (such as a CCD camera) 25 that detects an overlap margin x of the superimposition unit G, and a calculation unit 26 that monitors the overlap margin x and determines a control amount by comparing with a predetermined value. ing.

The drive device (such as a motor) M ₁ is provided at a base end portion of the core rod 13, a proximal end, middle, (such as cams or rollers) eccentric device provided with a plurality tip like 23 may be collectively operated the but Alternatively, each eccentric device (such as a cam or a roller) 23 may be operated independently to adjust the overlap margin x.

  However, the present invention is not limited only to this. For example, as another overlap margin adjusting means 22, the eccentric device (cam or roller or the like) 23 may be provided outside the core rod 13 as shown by a chain line in FIG. Further, the metal foil base plate W is provided around the core bar 13 so that a non-adhered portion where the metal foil base plate W is not in close contact with the core bar 13 is generated, and a part of the circumference of the metal foil base plate W is pressed by a pressing member. It may be displaced in the radial direction.

  Further, as schematically shown in FIG. 6, a part of the circumference of the metal foil plate W is formed by a pressing member 25 provided outside the core bar 13 toward the concave portion 24 formed in the core bar 13. As shown by the upper broken line, pressure may be applied so as to be displaced in the radial direction. These pressing members may be any of a cam, a roll, a cylindrical body, and a rod-shaped member.

  Experiments have shown that it is desirable that the overlap margin (x) satisfies x ≦ 40 + 5t (unit is μm) as the plate thickness (t).

  Next, the welded portion 30 will be described. The welding in the present embodiment is a resistance welding method. This is because an extremely thin metal foil base plate W is welded, so that the welding method must be easy to control. In particular, among the resistance welding methods, a seam welding method is preferable, and a mash seam welding is more preferable. When this welding was used, the difference in hardness between the welded portion and the other portions was small, and favorable results were obtained. If laser welding, plasma welding, or the like is used, the difference in hardness will be 30% or more, which has been found to be impractical.

  FIG. 6 is an enlarged sectional view showing a welding state of the present embodiment. As shown in FIG. 6, the welding portion 30 includes a conductive fixed electrode member 31 provided on the outer surface of the core rod 13 along the axial direction, and a conductive movable member provided to face the fixed electrode member 31. And an electrode member 32. The overlapped portion G of the metal foil sheet W is sandwiched and welded between the two electrode members.

  The fixed electrode member 31 is a conductive member provided in a groove 33 formed on the outer surface of the core rod 13 along the axial direction. On the other hand, the movable electrode member 33 is a conductive electrode wheel (the reference numeral “32” is used) that rotates and moves while pressing the overlapping portion G.

  The fixed electrode member 31 is made of a copper material provided in a groove 33 provided on the top of the core rod 13. Since the electrode wheel 32 performs welding while rolling on the fixed electrode member 31, the fixed electrode member 31 is fixed. It is preferable that the upper surface of the member 31 be formed entirely flat. Therefore, as the fixed electrode member 31, for example, a flattened copper wire is used. However, the entire upper surface does not need to be a flat surface, and may be partially flat. On the other hand, if the upper surface of the fixed electrode member 31 is a flat surface, the outer peripheral surface is preferably a flat surface. However, if the upper surface of the fixed electrode member 31 is an arc surface, the outer peripheral surface has a concave shape. A thing, that is, a drum-shaped thing is preferable. The radius of curvature in this case is preferably larger than the radius of curvature of the arc-shaped surface of the fixed electrode member 31.

The electrode wheel 32 is connected to a power supply member 35 via a conductive flange-shaped rotating member 34 as shown in FIG. 4, but the power supply member 35 is supported by a non-conductive bracket 36. . The bracket 36 is movable up and down linked by a cylinder C _5. Cylinder C ₅ is attached to the moving block 37, the moving block 37, a pair of guide rods 38 (see FIG. 3) is slidably supported, a screw shaft provided so as to pass through a central 39 moves along the axis of the core rod 13. The screw shaft 39 is supported by a bearing portion 42 provided on the support 40, 41, connected to the drive device via a coupling 43 such as a motor is rotated by M _2. In other words, the electrode wheels 32 is adapted to move from the proximal end of the screw shaft 39 and the drive device (such as a motor) M ₂ by the core rod 13 while elevating the cylinder C ₅ to the tip.

  The hardness of each of the electrode members 31 and 32 is preferably substantially the same as the hardness of the metal foil base plate W to prevent uneven contact and uneven wear and perform reliable welding over a long period. Experiments have shown that if the Vickers hardness HV is 180 or less, there is little damage to the electrodes. In order to increase the high-temperature strength and the creep strength, at least a part of each of the fixed electrode member 31 and the movable electrode member 33 may be made of molybdenum or an alumina-dispersed copper alloy.

  In the present embodiment, the superposed portion G with a small overlap margin x of 0.1 mm of the extremely thin metal foil base plate W of 10 to 100 μm is welded, so that the current value and the feed speed are problems. The best results were obtained with a current value of about 700 to 1500 amps, a voltage of about 0.5 to 2.0 volts, and a feed rate of about 0.3 to 1.5 m / min.

  However, when an electric current is applied, the welded portion 30 is heated, and if the welding operation is performed for a long time, the heat may deform the thin metal foil base plate W, making it impossible to perform good welding. Since the metal foil base plate W is wound around the outer peripheral surface of the long core rod 13 to form the metal foil tube P, peeling or removal of the metal foil tube P is also a problem.

  Therefore, in the present embodiment, various measures are taken on the core rod 13 itself as a means for solving the cooling problem and the problem of taking out at once.

  First, since the core bar 13 also functions as a mold for forming the metal foil base plate W into a circular cross section, the core bar 13 has a circular cross section as a whole, but as shown in FIG. Is provided with a core portion 13a made of a normal carbon steel for machine structure having a Y-shaped cross section, and on this core portion 13a, made of chromium steel having excellent strength for holding the fixed electrode member 31 is provided. The electrode support portion 13b is attached, and a side plate portion 13c is provided on a side portion of the core portion 13a to finish the whole with a circular cross section.

  In this way, even if the fixed electrode member 31 is worn, it is easy to replace the fixed electrode member 31 and it is easy to form the whole when the fixed electrode member 31 is formed to have a circular cross section.

  A fluid passage 45 is formed inside the core rod 13 as shown in FIGS. The fluid passage 40 includes a central passage 45a formed at a central portion along the axis of the core rod 13, and a branch passage 45b formed radially from the central passage 40a. FIG. 7 is a schematic sectional view taken along the axis of the core rod.

  Air is introduced into the fluid passage 45 from a pipe 47 connected to an end of the core rod 13 via a rotary joint 46 (see FIG. 2), and the air is used to cool the core rod 13 and from the branch path 45b. Air is blown out, thereby floating the metal foil tube P from the surface of the core rod 13 to facilitate removal.

  The use of air has the effect of providing a clean work environment with good workability, but is not limited to this, and other fluids, such as water or cutting oil, can also be used. .

  Further, in order to easily remove the metal foil tube P from the core rod 13, a notch R (see FIG. 6) formed to extend in the axial direction may be provided on the outer peripheral surface of the core rod 13. The contact area between the metal foil base plate W and the core bar 13 is reduced, and the removal of the metal foil tube P becomes easier.

  Regarding this removal, the core rod 13 itself may be composed of a plurality of members, and after the metal foil tube P is formed, it may be disassembled. FIG. 8 is a schematic cross-sectional view along another axis showing another example of the core rod. For example, as shown in FIG. 8, the core rod 13 is divided into two core rod members 13d and 13e by a tapered surface 50 intersecting the axis, and after forming a metal foil tube, one core rod member 13e is replaced with the other core rod. The metal foil tube P may be peeled from the core rod 13 by sliding in the axial direction with respect to the member 13d. However, when detaching using such a divided core rod 13, it is preferable that the core rod 13 is supported at both ends and one of the core rods 13 is configured to be movable in the axial direction.

  As shown in FIG. 1 (C), the metal foil tube obtained by the above embodiment can have a metal foil tube having a joint where the overlapped portion G is welded linearly. However, the present invention is not limited to these. For example, as shown in FIG. 1 (D), to obtain a metal foil tube having a joint where the overlapped portion G ′ is welded in a spiral shape. You can also. In this case, for example, a metal foil having an appropriate thickness is slit into an appropriate width, and this is spirally wound around an electrode rod made of a copper alloy. At this time, the overlap margin x between the foils is adjusted to about 0.1 mm using a detection device. Further, the electrode rod is slid left and right while rotating, and another electrode roller made of a copper alloy or the like is rolled on the overlapped portion, and a current flows between the electrode rod and the electrode roller, thereby causing an electric resistance. Welding (preferably seam welding, more preferably mash seam welding) may be performed. Thereafter, the tube is cut into an appropriate length, and the inner and outer surfaces near the joint are polished as necessary to obtain a desired metal foil tube.

  The ratio of the thickness of the metal foil plate to the inner diameter of the metal foil tube is preferably 1/300 or less, more preferably 1/500 or less. The thickness of the metal foil plate and the inner diameter of the metal foil tube used here have an allowable range error, so that an average value at a plurality of locations (for example, about 5 to 10 locations) is used.

  In the case where seam welding is performed by energizing between the electrode rod and the electrode rod, the welded portion may be a continuous nugget (melted and solidified portion) along the welding line or 50 negative along the welding line. %, The strength of the welded portion can be stably increased by the presence of the intermittent nugget in the portion of not less than%. That is, in seam welding, once a nugget is generated, much of the current flows through the nugget portion having a small electric resistance (reactive current) even if the disk-shaped electrode (see reference numeral 32 in FIG. 6) advances (reactive current). Only a small amount of current flows through the interface to be joined due to the high electrical resistance. Therefore, this portion is brought into a pressure contact state without reaching the melting temperature. Once the press-contact portion is formed, the electric resistance is also reduced here, so that the nugget is prevented from being generated in the same manner as the nugget. In order to avoid such a vicious cycle, the present inventors perform seam welding using a pulsed power source, provide a relatively long non-energization time after a short energization time, and obtain a continuous nugget by repeating this cycle. succeeded in. In this case, the optimal ratio between the energizing time and the non-energizing time is 1/12 to 1/8, and if it is less than 1/12 or more than 1/8 to 1/6, an intermittent nugget is generated. Further, according to the experiments of the present inventors, it has been found that even if the nugget becomes an intermittent nugget, if the nugget covers 50% or more of the welding line, there is no problem in strength. It is desirable to set the ratio of the non-energizing time to 1/15 to 1/7 and perform seam welding. Thereby, a nugget covering 50% or more of the welding length can be obtained.

  Similarly, when performing mash seam welding using a pulsed power source, as described above, it has been found that there is an optimal ratio between the energizing time and the non-energizing time in order to more stably increase the strength of the welded portion. It is a thing. That is, in mash seam welding, it is desirable to perform welding by using a pulse power source and setting the ratio of the energizing time to the non-energizing time to 1/3 to 1/1.

<Production method of metal foil tube>
The operation of the metal foil tube manufacturing apparatus thus configured and the method of manufacturing the metal foil tube will be described.

<Molding process>
The metal foil blank W having a thickness of 10 to 100 μm is placed on the holding plate 17 of the forming apparatus 15 by a conveying means such as a negative pressure suction means. The metal foil base plate W is held by a guide member (not shown), and set so that the center line thereof coincides with the center axis of the core rod 13 and the center line of the concave portion 20 formed in the holding plate 17.

While holding plate 17 from this state starts to increase by the cylinder C _1, the holding plate 17 is always kept a position parallel with the core rod 13. Therefore, when the metal foil base plate W comes into contact with the core rod 13, the metal foil base plate W has substantially the same width around the core rod 13. When the metal foil base plate W comes into contact with the core rod 13, the positioning member 16 operates.

The positioning member 16, the rod is actuated by a cylinder C _4, abuts from below the center of the core rod 13, sandwiching the metal foil workpiece W between the core rod 13 and the rod end. Since this pinching is performed at the base end, the center, and the distal end of the core rod 13, the metal foil W comes into contact with the core rod 13 over its entire length. Thus, the metal foil base plate W is positioned at substantially the center in the width direction.

After this positioning, the further actuating the cylinder C _1, the holding plate 17 is raised, the core rod 13 begins to enter into the recess 20 of the holding plate 17. As a result, the metal foil base plate W is gradually deformed into a U-shape. Then, when the core rod 13 enters the concave portion 20, the metal foil blank W is deformed into a part wound around the outer peripheral surface of the lower half of the core rod 13 and a pair of pieces standing upright from the side surface. .

First pressing member 18 is protruded by the operation of the cylinder C ₃ towards the piece of this one. This protrusion is performed until the arcuate surface portion 18a at the tip of the protrusion comes into contact with the outer periphery of the core rod 13, and the arcuate surface portion 18a presses a piece of the metal foil blank W onto the outer peripheral surface of the core rod 13 to make close contact therewith.

Next, the second pressing member 19 is operated similarly by the cylinder C _3, but arc surface portion 19a of the tip pushes the other piece of metal foil material plates W until it comes into contact with the outer periphery of the core rod 13, the pressing the final It stops just before the stage, so that the metal foil blank W does not completely adhere to the core rod 13.

  In other words, the metal foil base plate W is wound around the core rod 13 to form an overlapped portion G in which a pair of opposing side edges are overlapped at the top of the core rod 13, but the other piece is completely positioned. It is not a fixed state but a displaceable state.

In this displaceable state, the overlapping margin x of the overlapping portion G is adjusted. For this adjustment, a detection device (such as a CCD camera) 25 of the control unit 24 detects the overlap margin x amount, compares it with a predetermined value in an arithmetic unit 26, determines whether or not it is normal. (such as a motor) M ₁ eccentric device drives the (cam or roller, etc.) 23 to rotate and displace the metal foil workpiece W radius (radiation) in the direction.

When the overlap margin (x) in the overlap portion G satisfies x ≦ 40 + 5t (unit is μm) as the plate thickness (t), the adjustment of the overlap margin x is completed. In this state, the second pressing member 19 is actuated by the cylinder C <b> _3, and completely presses the other piece of the metal foil base plate W against the core rod 13. As a result, the metal foil base plate W is fixedly held on the core bar 13.

<Welding process>
When the holding of the metal foil base plate W is completed, the position of the overlapping portion G is between the tip of the first pressing member 18 and the tip of the second pressing member 19, and immediately above the fixed electrode member 31, Since the electrode wheel 32 can be moved up and down between the first pressing member 18 and the second pressing member 19, welding can be started.

  At the start of this welding, if the electrode wheel 32 is positioned at the base end of the core rod 13 and the whole is welded, accurate welding can be performed.

Welding is first performed from the operation of the cylinder C _5. When the cylinder C ₅ is operated, the piston rod is lowered and the bracket 36, the power supply member 35, the electrode wheels 32 via a flange-shaped rotary member 34 is lowered. The electrode wheel 32 enters between the distal end of the first pressing member 18 and the distal end of the second pressing member 19, and sandwiches the overlapping portion G with the fixed electrode member 31.

When applying current between the fixed electrode member 31 and the electrode wheels 32 together with the clamping, overlapping portions G are weld, but are welded to one another (such as a motor) at the same time drive unit M ₂ is also operated, the screw shaft 39 It rotates and the moving block 37 starts moving. Thereby, the electrode wheel 32 moves on the overlapped portion G at about 0.3 to 1.5 m / min, and welds to the end of the metal foil blank W.

  In some cases, the electrode wheel 32 may be positioned at the tip of the core rod 13 and the metal foil tube P may be pulled out while welding. In this way, quick welding with good workability can be performed.

<Finishing process>
When welding is completed, the welded portion is finished smoothly. This finishing is performed until the surface of the metal foil tube P becomes a smooth surface by polishing or lapping with a grindstone, crushing by roller burnishing, etc., but the description is omitted because it is well known.

  Then, the metal foil tube P is removed from the core rod 13. This removal is performed by supplying air to the fluid passage 45 from the end of the core rod 13 and ejecting air radially from the central passage 45a along the axis of the core rod 13 through the branch passage 45b. Is peeled off from the metal foil tube P. If air flows even slightly between the core rod 13 and the metal foil tube P, the metal foil tube P can be easily removed from the core rod 13. However, after the removal, the finishing may be performed.

  In the above-described embodiment, the movable electrode member travels on the fixed electrode member or the metal foil tube P is moved. However, the present invention is not limited to this, and when both electrode members move relatively or The case where the electrode member and the metal foil tube P move relatively may be used.

  The welded metal foil tube obtained by the above welding method can be widely used as it is as the welded metal foil tube of the present invention, and further, if necessary, obtained by the above welding method. The core metal is put into the welded metal foil tube, and then subjected to cold working by swaging, split roller rolling method, hole die method (drawing method), spatula drawing method or a combination of these methods to reduce the thickness of the welded metal tube. May be smoothed to adjust the shape and surface roughness of the welded portion, and the material may be work hardened.

  As a processing method of the welded portion of the metal foil tube, cold working by swaging, split roller rolling method, hole die method, spatula drawing method, or a combination of these methods can be performed. Since the swaging, the split roller rolling method, the hole die method, and the spatula drawing method are existing cold working techniques, the description of the working method here is omitted.

  In the present invention, since the welded portion of the welded metal foil tube is a target, it is difficult to handle it as it is. Therefore, a core metal is put in the metal foil tube in advance and can be applied to cold working (mainly plastic working). It can be said that each processing should be performed in the state.

  The core metal is, for example, a hardened material of S45C having an outer diameter that matches the inner diameter of the welding tube, and if the inner diameter of the tube changes due to processing, the outer diameter of the core metal is changed as needed. It is also desirable to replace them with those suitable for this.

  In swaging, the core is inserted into a welding tube, and the wall of the tube is made thinner while hitting the tube surface with three or four tools arranged outside the tube.

  In the split roller rolling method, after inserting the above core metal into the welding tube, multiple small diameter rollers arranged outside the tube are pressed with another jig or backup roll, and the tube and the multiple rollers are rotated relatively. While reducing the thickness of the tube.

  The hole die method is a method of squeezing a conical hole (die) through a slightly thicker material (here, a welding foil tube with a cored bar). If an appropriate lubricant is used, the thickness of the tube can be changed without changing the diameter of the tube. The thickness can be reduced.

  In the spatula drawing method, one or more spatulaes are pressed while rotating a welding foil tube containing a cored bar to reduce the wall thickness.

  In these cold workings, when the tube approaches the finished dimensions, the surface roughness of the tool or roller to be machined can be made sufficiently small, so that the shape of the welded part can be made uniform in thickness and smooth . In the present invention, the cold working is performed to reduce the wall thickness until the surface roughness Rz defined by JIS B0601-2001 (maximum height roughness) becomes 2.0 μm or less, preferably 0.1 to 1 μm. It is desirable that the weld be smoothed.

  Further, the Vickers hardness (Hv) of the material is 300 to 600 points, preferably 400 to 600 points, more preferably 450 to 550 points by performing the cold working to reduce the thickness and harden the material. It is desirable to be. As a result, as described above, it is possible to provide a welded metal foil tube having excellent durability and abrasion resistance and having a hardness effective for prolonging the high cycle fatigue life. Here, the Vickers hardness of the material includes the hardness of both the base material portion and the welded portion.

  Furthermore, in the method for manufacturing a metal foil tube of the present invention, when seam welding stainless steel, since the surface passivation film of stainless steel is strong, it completely breaks these to form a strong metal bond with the welding wire. In order to obtain the welding over the entire length, it is necessary to carefully examine the current, voltage, welding speed, energization ratio, and the like, and to perform welding within a considerably narrow range of welding conditions. In particular, in the case of mash seam welding in which two stacked foils are completely crushed to have a single thickness, the current density to a portion where the end faces of the foils are embedded is low. For this reason, the joint strength of this part is insufficient, and when it is repeatedly processed, an opening may be formed along the joint line. The present inventors have found that two methods are effective in solving this problem. One of them is to heat-treat a foil tube formed by joining or further forming a stainless steel foil by resistance welding or the like to diffusely join a joining line to reinforce strength. In this case, the heat treatment is preferably performed in a vacuum heat treatment or in an inert atmosphere. The heat treatment temperature is preferably from 800 to 1100 ° C. If the stainless steel is ferritic or martensitic, a lower temperature may be used, and if the stainless steel is austenitic, a higher temperature is required. On the other hand, when the temperature is lower than 800 ° C., diffusion bonding is not sufficiently performed, and when the temperature is higher than 1100 ° C., deformation is large during heat treatment, and crystal grains are undesirably coarsened. Further, the heat stress around the welded portion is released by the heat treatment, and there is also an effect of eliminating the rough feeling often seen around the welded portion. Further, when the above-mentioned hard plating is performed after the heat treatment, even small irregularities of the welded portion are hidden, so that the position of the welded portion cannot be recognized. As the metal to be hard-plated, a metal mainly composed of chromium, nickel, cobalt, palladium or the like can be used, and it is effective to add a small amount of an additive such as P in order to harden the metal. In the case of plating with a Ni-P alloy, the P concentration is preferably 1 to 14%. The reason is that if it is less than 1%, the effect of hardening is small, and if it is more than 14%, the plating layer is brittle and cracks easily occur. Electroless plating or electroplating is possible as a plating method, but electroless plating is convenient for plating the inside of the tube.

  A second method is to use a metal foil before welding on a metal foil of group 10 to 11 such as Au, Ag, Cu, Ni or an alloy containing these elements (for example, a Ni-P alloy), Al, or the like. A metal (including an alloy) having a melting point lower than the melting point of the metal foil described above, preferably a metal (including an alloy) having a melting point of 1200 ° C. or less, is plated and resistance-welded to obtain a metal foil tube. is there. In this method, even if the bonding line does not reach the melting point of the metal foil such as stainless steel, if the melting point of the plating layer is exceeded, the plating layer is melted, and the passivation film on the surface of the metal foil such as stainless steel is accompanied. The part is pushed out of the joint along the joint line. Thus, a perfect metal bond is obtained along the weld line. Further, small grooves may be formed in the portion where the end face of the foil is embedded, but there is also an advantage that the plated molten metal is also buried in this portion so that a notch does not occur in the joint.

  Further, in the method for manufacturing a metal foil tube according to the present invention, by welding the metal foil tube, the welded portion has a continuous nugget (melted and solidified portion) along the welding line or 50% or more along the welding line. It is desirable that there is an intermittent nugget in the portion. This is due to the fact that welds such as seam welds have a continuous nugget (melted and solidified portion) along the weld line or an intermittent nugget at 50% or more along the weld line. The reason for this is that the strength can be stably increased.

  Also, in seam welding, once a nugget is generated, much of the current flows through the nugget portion having a small electric resistance (reactive current) even if the disk-shaped electrode (see reference numeral 32 in FIG. 6) advances (reactive current), and a new nugget is generated. Only a small amount of current flows through the interface to be joined due to the high electrical resistance. Therefore, this portion is brought into a pressure contact state without reaching the melting temperature. Once the press-contact portion is formed, the electric resistance is also reduced here, so that the nugget is prevented from being generated in the same manner as the nugget. In order to avoid such a vicious cycle, the present inventors perform seam welding using a pulsed power source, provide a relatively long non-energization time after a short energization time, and obtain a continuous nugget by repeating this cycle. succeeded in. In this case, the optimal ratio between the energizing time and the non-energizing time is 1/12 to 1/8, and if it is less than 1/12 or more than 1/8 to 1/6, an intermittent nugget is generated. According to the experiments of the present inventors, it has been found that even if it becomes an intermittent nugget, if the nugget covers 50% or more of the welding line, there is no problem in strength. In order to obtain a nugget covering 50% or more of the welding length, it is necessary to set the ratio of the energizing time to the non-energizing time to 1/15 to 1/7. From the above, it can be said that in the method for producing a metal foil tube of the present invention, it is desirable to perform seam welding by using a pulse power source and setting the ratio of the energizing time to the non-energizing time to 1/15 to 1/7.

  Furthermore, the present inventors have found that even when performing mash seam welding using a pulse power source, in order to more stably increase the strength of the welded portion, there is an optimal ratio between the energizing time and the non-energizing time. It was found. That is, in the method for manufacturing a metal foil tube of the present invention, it is preferable to perform mash seam welding by using a pulse power source and setting the ratio of the energizing time to the non-energizing time to 1/3 to 1/1.

  The effects of the present invention will be described using the following examples and comparative examples. However, the technical scope of the present invention is not limited to the following examples. In addition, a dimensional unit that does not particularly indicate a unit is a “mm” unit.

Example 1
SUS410L (11Cr-0.02C) stainless steel is rolled to a thickness of 40 μm, respectively, so that the surface roughness Rz of the foil becomes 1.5 μm and 0.8 μm by appropriately controlling the roll surface roughness. Then, the as-rolled material was cut into 94.3 L × 250 W. Each of the foils having the two kinds of surface roughness was wound around a copper alloy jig having a diameter of 30φ, and a 100 μm overlapping portion was joined by mash seam welding. At this time, the periphery of both joints (a tube with a surface roughness Rz of 1.5 μm and a tube with a surface roughness Rz of 0.8 μm) is cut out and polished and polished, so that the hardness of the base material is around 270 in Hv. It was confirmed that the hardness of the joint was about 230 in Hv. As a result of etching the both polished samples and examining the metallographic structure, there was no melt-solidified phase at the joint, the low carbon martensite phase was observed at the joint surface in the solid-phase joined state. The thickness of both joints was 55 μm. Both tubes (see FIG. 1 (C)) were each cut to a length of 50 mm, and the inner and outer surfaces around the joint were polished to reduce the thickness of the joint to about 42 μm. In both cases, a hard sponge cylinder was inserted, and this was rotated while pressing it against the surface of a 120φ × 80 L steel roller, and the fatigue life was examined. At this time, the rotation speed of the test tube was 120 rpm, and the test tube was crushed by about 4 mm in a state of being pressed most against the steel roller. At this time, the strain applied to the test tube surface was 0.17%. As a result of the test, no abnormality was found in the test tube even after both tubes (the tube with the surface roughness Rz of 1.5 μm and the tube with the surface roughness Rz of 0.8 μm) were rotated more than 1,000,000 times. Was.

Example 2
SUS316L (16Cr-12Ni-2Mo) 30 μm thick annealed foil having a surface roughness Rz of 1.0 μm and 0.5 μm was slit to a width of 60 mm, respectively, and this was cut into a 30φ copper alloy electrode rod. Spirally wrapped around it. At this time, the overlap between the foils was adjusted to 100 μm for both the surface roughness Rz of 1.0 μm and the surface roughness Rz of 0.5 μm. Further, the electrode rod is slid left and right while rotating, and another copper alloy electrode roller is rolled on the overlapped portion, and electricity is supplied to the electrode rod to perform mash seam welding. Was. As a result of examining the hardness around both the joints in the same manner as in Example 1, both were about Hv200 at the base metal part and around 245 at the joint. In addition, the metal structures were examined, and it was confirmed that both had no melt-solidified phase. Further, both of these tubes (see FIG. 1D) were cut to a length of 50 mm, the inner and outer surfaces near the joint were polished, and a fatigue test was performed in the same manner as in Example 1.

  The strain applied to the test tube surface in the test was 0.13%. As a result, both of these tubes (the tube having a surface roughness Rz of 1.0 μm and the tube having a surface roughness Rz of 0.5 μm) survived a fatigue test of 1,000,000 times or more.

Example 3
Two types of foil tubes were prepared in the same manner as in Example 1 using a 50 μm thick fully annealed foil of SUS304 (18Cr-8Ni) having a surface roughness Rz of 0.3 μm and 0.8 μm. Incidentally, this stainless steel foil is annealed in Ar-H ₂ atmosphere, the nitrogen concentration in the surface was 1.2%. In both cases (the tube having a surface roughness Rz of 0.3 μm and the tube having a surface roughness Rz of 0.8 μm), the thickness of the joint was 75 μm, but was reduced to 60 μm by polishing the inner and outer surfaces. In this case, both the hardness of the base material portion was around 178 in Hv, and the joint portion was around 220 in Hv. As a result of performing a fatigue test in the same manner as in Example 1, both of the tubes (a tube having a surface roughness Rz of 0.3 μm and a tube having a surface roughness Rz of 0.8 μm) were subjected to a fatigue test of 1,000,000 times or more. Endured.

Example 4
A foil tube was prepared in the same manner as in Example 1 using a 50 μm-thick completely annealed foil of SUS304 (18Cr-8Ni) having a surface roughness Rz of 0.34 μm. The stainless steel foil was annealed in an ammonia decomposition gas, and the nitrogen concentration on the surface was 4.4%. The thickness of the joint portion was changed from 77 μm to 60 μm by polishing the inner and outer surfaces. In this case, the hardness of the base material portion was around 190 in Hv, and the joint portion was around 230 in Hv. As a result of performing a fatigue test in the same manner as in Example 1, the tube was subjected to a 500,000-time crack at the time of 500,000 times, and thus the fatigue test was stopped. It is durable and can be used sufficiently depending on the application.

Example 5
A foil tube was produced in the same manner as in Example 1 using a 50 μm thick hard material of SUS304 (18Cr-8Ni) having a surface roughness Rz of 0.5 μm. The thickness of the joint was 90 μm, but was reduced to 60 μm by polishing the inner and outer surfaces. In this case, the hardness of the base material portion was around 410 in Hv, the joint portion was around 230 in Hv, and the hardness difference between the joint portion and the base material portion was 43% of the base material hardness. As a result of performing a fatigue test in the same manner as in Example 1, the tube was broken at 500,000 times at the boundary between the joint and the base material due to cracking. Also in this case, it has a durability of up to 500,000 times depending on the intended use, and can be sufficiently used depending on the intended use.

Example 6
A foil tube was prepared in the same manner as in Example 1 using as-rolled foil of SUS420J1 (13Cr-0.18C) having a surface roughness Rz of 0.7 μm and having a thickness of 20 μm. The thickness of the joint portion was changed from 32 μm to 23 μm by polishing the inner and outer surfaces. In this case, the hardness of the base material was about 340 in Hv, and the joint was about 315 in Hv. As a result of performing a fatigue test in the same manner as in Example 1, this tube survived a fatigue test of 2,000,000 times or more.

Example 7
Using a 20 μm thick as-rolled foil of SUS630 (17Cr-4Ni-4Cu-0.2Nb-0.1Ta) having a surface roughness Rz of 0.9 μm, a foil tube was prepared in the same manner as in Example 1. did. The thickness of the joined portion was changed from 35 μm to 26 μm by polishing the inner and outer surfaces. Thereafter, the resultant was heated to 1040 ° C. in a vacuum heat treatment furnace, and then uniformly heated at 480 ° C. for 1 hour in a cooling process to precipitate and harden. In this case, the hardness of the base metal part and the hardness of the welded part were almost the same, and were about 380 in Hv. As a result of performing a fatigue test in the same manner as in Example 1, this tube survived a fatigue test of 2,000,000 times or more.

Example 8
Using a 25 μm thick as-rolled foil of YUS170 (Nippon Steel Standard: 24Cr-12Ni-0.7Mo-0.35N) having a surface roughness Rz of 0.85 μm, in the same manner as in Example 1, A tube was made. The thickness of the joint was 30 μm, but was reduced to 22 μm by polishing the inner and outer surfaces. In this case, the hardness of the base material was about 290 in Hv, and the joint was about 220 in Hv. As a result of performing a fatigue test in the same manner as in Example 1, the tube withstood a fatigue test of 1,000,000 times or more.

Comparative Example 1
In each of Examples 1 to 8, a foil tube for each stainless steel foil material was prepared in the same manner as in Examples 1 to 8, except that each stainless steel foil was joined by laser welding instead of electric resistance welding (mash seam welding). Were prepared and subjected to a fatigue test. In each case, cracks occurred at the boundary between the joined portion and the base material at 100,000 to 300,000 times, and fracture occurred.

Comparative Example 2
A foil tube for each stainless steel foil material was prepared in the same manner as in Examples 1 to 8, except that the stainless steel foils were joined by plasma welding instead of electric resistance welding (mash seam welding) in Examples 1 to 8. Were prepared and subjected to a fatigue test. In each case, cracks occurred at the boundary between the joined portion and the base material at 100,000 to 300,000 times, and fracture occurred.

Example 9
As in Example 1, using a completely annealed foil of SUS304 having a surface roughness Rz of 0.9 μm and a thickness of 60 μm (nitrogen concentration on the surface was 1.2%) annealed in an Ar—H ₂ atmosphere. Seven tubes of 24 to 30 mmφ × 250 mmL were produced by a mash seam welding method. After that, about 6 of these, a hardened S45C metal core was further inserted into the tube, and cold working was performed by swaging, split roller rolling, hole die, spatula drawing, or a combination of these methods. To reduce the wall thickness, smoothen the welded part, adjust the shape and surface roughness of the welded part, and simultaneously work harden the material to obtain foil tubes each having a thickness of about 30 μm. The dimensions, materials, fatigue life, and the like of these foil tubes before and after cold working (ie, unprocessed products and processed products) were measured, and the results are summarized in Table 1.

  The tube thickness in Table 1 indicates the thickness of the non-joined portion (base material portion).

  The hardness in Table 1 above indicates the Vickers hardness of the base material.

  The surface roughness Ra of the welded portion in Table 1 is measured according to (JIS B0601 2001 arithmetic average roughness).

  The surface roughness Rz of the welded portion in Table 1 is measured according to JIS B0601-2001 (maximum height roughness) of the metal foil.

  The fatigue life in Table 1 was determined by inserting a hard sponge cylinder into each foil tube and rotating it while pressing it against the surface of a 120 mmφ × 80 mmL steel roller, as in Example 1. At this time, the rotation speed of the test tube was 360 rpm, and the test tube was crushed by about 4 mm while being pressed most against the steel roller. The strain applied to the test tube surface at this time was 0.34, 0.16, 0.18, 0.19, 0.17, 0.16, and 0.17%, respectively. The test was performed until abnormalities such as cracks were confirmed in the foil tube, and the operating time (hr) during this period was defined as the fatigue life.

  The cold working conditions in Table 1 above were as follows.

    (2) Swaging; Starting from a 26 mmφ welding tube, the others are as described above.

    (3) Three-split roller rolling method; starting from a welding tube of 24 mmφ, the others are as described above.

    (4) Hole die method: Starting from a 30 mmφ welding tube, the others are as described above.

    (5) Spatula drawing method: Starting from a welding tube of 24 mmφ, the others are as described above.

    (2) + (3); starting from a welding tube of 24 mmφ, others as above.

    (5) + (4); Starting from a 26 mmφ welding tube, others as above.

Example 10
SUS301, SUS201, SUS316N, and YUS170 (24Cr-12Ni-0.3N) having a surface roughness Rz of 1.2 μm and annealed in an Ar—H ₂ atmosphere and a 25 μm-thick completely annealed foil (the nitrogen concentration of the surface is 1) And a tube of 30 mmφ × 250 mmL by a mash seam welding method in the same manner as in Example 1. Thereafter, a foil tube having a thickness of about 25 μm was obtained from these tubes by the same swaging and split roller rolling method (cold working of (2) + (3) above) as in Example 9. Table 2 summarizes the dimensions, materials, fatigue life, etc. of these foil tubes before and after cold working.

  The tube thickness (μm), hardness (Hv), weld surface roughness Ra (μm), weld surface roughness Rz (μm) and fatigue life (hr) in Table 2 are described in Table 1. As you did.

  The strain applied to the test tube surface in the fatigue life test was 0.28, 0.15, 0.28, 0.14, 0.28, 0.14, 0.28, and 0.14%, respectively. there were.

Example 11
A SUS316 foil having a thickness of 25 μm was seam-welded in the same manner as in Example 1 to obtain a foil tube of 30 mmφ × 250 mmL. This was subjected to hard Cr plating with a target thickness of 2 μm. On the inner surface of the foil tube, a rod-shaped Cr electrode was put, and Cr plating was performed on the inner and outer surfaces. In addition, another SUS316 foil tube welded in the same manner was subjected to electroless plating of Ni-8% P, Co, and Pd with a target thickness of 2 μm. The ends of these tubes were cut and the cross section was buried and polished, and the thickness of the plating film (layer) was examined. Separately, in order to measure the hardness of the plating layer, the same material as described above was plated on an iron plate to a thickness of about 30 μm, embedded in resin, polished, and the hardness was measured. Each of the above-mentioned plated foil tubes and a non-plated foil tube as a comparative material were incorporated into a fixing roll of a printer, and half a cup of iron powder was spread on the inner surface of the tube and then rotated for 10 minutes. Thereafter, the tube was removed, cut open, and the state of occurrence of internal flaws was observed. These results are summarized in Table 3.

  As shown in Table 3, the hardness of each plating layer was Hv of 400 or more, and these foil tubes did not generate flaws even in a poor environment where iron powder was sprayed on the inner surface of the fixing roll. . On the other hand, the unplated foil tube had many linear scratches.

Example 12
Electroless plating of Ni-2% P, Ni-8% P and Ni-12% P having a thickness of about 2 [mu] m was performed on both sides of a SUS316 foil having a thickness of 30 [mu] m. Separately from these, electroplating of Al and Ag having a thickness of about 2 μm was performed on the vicinity of the welded portion of the foil, that is, on both surfaces between 2 and 3 mm from the cut end surface of the foil. These foils were formed into tubes of 30 mmφ × 250 mmL by mash seam welding. The weld was cut out, embedded and polished, and the cross-sectional shape and metal structure of the weld were observed. As a result, while the thickness of the base material portion was 34 μm including the plating layer, the thickness of the welded portion where the two foils overlap was 35 to 37 μm, almost crushed to the thickness of the base material portion. I was Further, close bending was performed around the welded portion, and this was embedded in a resin, and the metal structure of the bent portion was observed. As a comparative material, an unplated SUS316 foil having a thickness of 40 μm was subjected to mash seam welding in the same manner, and a welded portion was cut out and bent tightly. Further, this portion was embedded in a resin and polished, and a metal structure was observed. As a result, the welded portion of the non-plated foil opened slightly at the portion where the joining line reached the foil surface due to close contact bending, but the contact bent portion of the welded portion of the plated foil did not open at all.

Example 13
SUS304 and SUS420J2 foils having a thickness of 40 μm were formed into tubes of 30 mmφ × 250 mmL by mash seam welding. After welding, the SUS304 tube was subjected to vacuum heat treatment at 1030 ° C. × 3 minutes, and the SUS420J2 was subjected to vacuum heat treatment at 880 ° C. × 10 minutes. The vicinity of the welded portion of the tube after the heat treatment was cut out, tightly bent around the welded portion, embedded and polished and etched, and the structure of the welded portion was observed. As a result, it was found that the welded portion was able to withstand tight bending without opening the mouth at all.

Example 14
Electroless plating of Ni-8% P was performed on the inner and outer surfaces of the SUS304 and SUS420J2 foil tubes prototyped in Example 13. Each of these tubes was subjected to the same flaw test with iron powder as in Example 11, but no linear marks were generated. Further, these tubes were subjected to the above-mentioned fatigue test, and no fracture of the weld was observed after 7.5 million cycles.

Example 15
A tube of 30 mmφ × 250 mmL was seam-welded using SUS316 foil having a thickness of 40 μm. At this time, a pulse power source was used as a welding power source, the ratio of the energizing time to the non-energizing time was changed variously, the metal structure of the weld was observed, and the state of nugget formation was observed. Table 4 shows the results.

  As shown in Table 4, when the energizing time / non-energizing time was set to 1/15 to 1/7, the nugget length was 50% or more along the welding line, indicating that good welding was performed.

(A) is a plan view of a metal foil base plate to be formed into a metal foil tube, (B) is a cross-sectional view of the metal foil tube before welding, (C) is a perspective view of a metal foil tube having a straight joining portion, (D) is a perspective view of a metal foil tube having a spiral joint. It is a schematic side view of a metal foil tube manufacturing device concerning an embodiment of the present invention. FIG. 3 is a plan view of FIG. 2. FIG. 4 is a sectional view taken along line 4-4 in FIG. 3. FIG. 4 is an enlarged sectional view of a main part. It is an expanded sectional view showing the welding state of this embodiment. It is a schematic sectional drawing which follows the axis of a core rod. It is the schematic which shows the other example of a core rod.

Explanation of reference numerals

13 core rod,
13d, 13e core rod member,
15 molding equipment,
16 positioning members,
17 holding plate,
18 a first pressing member,
19 a second pressing member,
20 recesses,
22 Overlap margin adjustment means,
23 eccentric devices (such as cams or rollers),
25 pressure member,
24 recess,
31 fixed electrode members,
32 movable electrode members (electrode wheels),
45 fluid passages,
G, G 'overlapping part,
P metal foil tube,
R Notch,
t board thickness (metal foil thickness),
W metal foil base plate,
x Overlay.

Claims (76)

  A metal foil tube obtained by joining or welding metal foil having a thickness of 10 to 100 μm. The metal foil is a stainless steel foil,
The metal foil tube according to claim 1, wherein the material of the stainless steel foil is any one of ferritic stainless steel, martensitic stainless steel, austenitic stainless steel, and precipitation hardening stainless steel.   The metal foil tube according to claim 1 or 2, wherein the metal foil tube is joined by electric resistance welding.   The metal foil tube according to any one of claims 1 to 3, wherein the electric resistance welding is seam welding.   5. The metal foil according to claim 4, wherein the seam welding is performed by using a pulsed power source and performing welding by setting a ratio of an energizing time to a non-energizing time to 1/15 to 1/7. tube.   The metal foil tube according to any one of claims 1 to 5, wherein the electric resistance welding is mash seam welding.   7. The metal according to claim 6, wherein the mash seam welding is performed by using a pulsed power source and setting the ratio of energizing time to non-energizing time to 1/3 to 1/1. Foil tube.   The metal foil tube according to any one of claims 1 to 7, wherein at least a part of the bonding surface is solid-phase bonding.   The metal foil tube according to any one of claims 1 to 8, wherein joining or welding lines are arranged in a straight line or a spiral shape.   The absolute value of the hardness difference between the joined or welded portion and the base material portion is not more than 25% of the hardness of the base material portion in Vickers hardness (Hv), 10. 2. The metal foil tube according to item 1.   The metal foil tube according to any one of claims 1 to 10, which is subjected to cold working to reduce the wall thickness, smoothen the joint, adjust the shape and surface roughness of the joint, and at least form the joint member. A metal foil tube obtained by work hardening.   The metal foil tube according to any one of claims 3 to 11, wherein the metal foil is a stainless steel foil, and the stainless steel foil is an austenitic stainless steel annealed material.   The Vickers hardness of a base material part is 180 or less, The metal foil tube as described in any one of Claims 1-12 characterized by the above-mentioned.   The Vickers hardness of a material is 300-600, The metal foil tube as described in any one of Claims 1-12 characterized by the above-mentioned.   The metal foil tube according to any one of claims 11 to 14, wherein the maximum nitrogen concentration in the surface layer of the stainless steel foil is 3% by mass or less. The bulk component is
C: 0.05% by mass or less,
Si: 0.05 to 3.6% by mass,
Mn: 0.05 to 1.0% by mass,
Cr: 15 to 26% by mass,
Ni: 5 to 25% by mass,
Mo: 2.5% by mass or less,
Cu: 2.5% by mass or less,
N: 0.06% by mass or less,
The metal foil tube according to any one of claims 3 to 15, wherein the metal foil tube comprises a soft austenitic stainless steel containing Fe and unavoidable impurities. The bulk component is
C: 0.05 to 0.2% by mass,
Si: 0.05 to 3.6% by mass,
Mn: 1.0 to 5.0 mass%,
Cr: 15 to 26% by mass,
Ni: 5 to 25% by mass,
Mo: 5.0% by mass or less,
Cu: 4.0% by mass or less,
N: more than 0.06% by mass to 0.4% by mass,
The metal foil tube according to any one of claims 3 to 11, wherein the metal foil tube is a high-strength austenitic stainless steel containing Fe and inevitable impurities.   The metal foil tube according to any one of claims 3 to 12, wherein the metal foil is an as-rolled material of ferritic stainless steel or martensitic stainless steel, and a martensite phase is precipitated at a weld.   The metal foil tube according to any one of claims 1 to 18, wherein at least one of the surface and the inner surface of the foil tube obtained by joining and forming the metal foil is surface hardened by a hard plating layer. .   20. The metal foil tube according to claim 19, wherein the composition of the plating layer is mainly one or more metals of chromium, nickel, cobalt, and palladium.   The metal foil tube according to claim 19, wherein the composition of the plating layer is a Ni-P-based alloy.   At least one of the two surfaces of the stainless steel foil is plated with a Group 10 to 11 element or an alloy containing one or more of these elements, or a metal having a melting point of 1200 ° C. or less, in the vicinity of at least one of the joints. The metal foil tube according to any one of claims 1 to 21, wherein the tube is welded.   The metal foil tube according to claim 21 or 22, wherein the composition of the plating layer is a Ni-P alloy containing 1 to 14% of P by weight ratio.   The metal foil tube according to any one of claims 1 to 18, wherein the foil tube obtained by joining or further forming a stainless steel foil is heat-treated at a temperature of 800 to 1100 ° C.   The heat treatment of the foil tube which joined or formed the stainless steel foil at a temperature of 800 to 1100 ° C., followed by hard plating at least one of the inner and outer surfaces of the foil tube. 2. The metal foil tube according to claim 1.   The welded portion of the metal foil tube may have a continuous nugget (melted and solidified portion) along a weld line or an intermittent nugget at a portion of 50% or more along a weld line. Item 26. The metal foil tube according to any one of items 1 to 25.   27. The overlap margin (x) of the joining portion of the metal foil tube satisfies x ≦ 40 + 5t (unit is μm) as the foil thickness (t) of the metal foil. The metal foil tube according to claim 1.   The metal foil tube according to any one of claims 1 to 27, wherein a ratio of a wall thickness of the tube to an inner diameter of the tube (wall thickness / inner diameter) is 1/500 or less.   29. The metal according to claim 1, wherein the metal foil tube has a surface roughness Rz defined by JIS B0601-2001 (maximum height roughness) of 2.0 μm or less. Foil tube. 30. The metal foil tube has a durability of 1 × 10 ⁶ times or more in a fatigue test in which a strain of 0.2% or less is given to the metal foil tube at a repetition cycle of 60 cycles / min or more. The metal foil tube according to claim 1.   The metal foil tube according to any one of claims 1 to 30, wherein the metal foil tube is used for a toner baking roll and / or a developing roll of an image forming apparatus.   A method for producing a metal foil tube, comprising: a forming step of forming a metal foil base plate having a thickness of 10 to 100 μm such that a pair of opposed sides are overlapped; and a welding step of welding the overlapped opposed sides.   The method for manufacturing a metal foil tube according to claim 32, further comprising a finishing step of finishing the welded portion smoothly.   The manufacturing of the metal foil tube according to claim 32 or 33, wherein the forming step includes a positioning step of positioning the metal foil base plate on a forming core bar before overlapping the opposing sides of the metal foil base plate. Method.   In the positioning step, the metal foil base plate is held in a molding device that is always close to and separated from the core bar while maintaining a parallel position, and the metal foil plate and the core bar are brought into line contact by bringing the molding device closer to the core bar. 35. The method for manufacturing a metal foil tube according to claim 34, wherein the metal foil base plate is pressed against the core bar and positioned at the time.   The molding step further approaches the molding device toward the core rod after the positioning step, and holds the metal foil base plate between the core rod and the semicircular concave portion formed in the molding device. The method for producing a metal foil tube according to claim 34 or 35, comprising a winding step of winding the metal foil base plate around a core rod.   37. The manufacturing of the metal foil tube according to claim 36, wherein the forming step includes a lap margin adjusting step of adjusting a lap margin by radially displacing a part of the circumference of the metal foil base plate after the winding step. Method.   The method for manufacturing a metal foil tube according to claim 36 or 37, wherein the overlap margin (x) satisfies x ≦ 40 + 5t (unit is μm) as the plate thickness (t).   The method for manufacturing a metal foil tube according to claim 32 or 33, wherein the welding is an electric resistance welding method.   The method for manufacturing a metal foil tube according to any one of claims 32 to 39, wherein the electric resistance welding is seam welding or mash seam welding.   Seam welding is performed by setting the ratio of energizing time and non-energizing time to 1/15 to 1/7 using a pulse power source, or the ratio of energizing time to non-energizing time is set to 1/3 to 1/1 using a pulse power source. 41. The method for producing a metal foil tube according to claim 40, wherein mash seam welding is performed with the setting being set to.   The welding includes a conductive fixed electrode member provided in a groove formed along the axial direction on the outer surface of the core rod, and a conductive movable electrode member provided to face the fixed electrode member. The method for producing a metal foil tube according to any one of claims 32, 33, and 39 to 41, characterized in that the method is performed by applying a current between the two.   43. The method for manufacturing a metal foil tube according to claim 42, wherein the fixed electrode member is formed such that part or all of an outer surface thereof is flat.   The method according to claim 42 or 43, wherein at least a part of each of the fixed electrode member and the movable electrode member is made of molybdenum or an alumina-dispersed copper alloy.   The method for manufacturing a metal foil tube according to any one of claims 42 to 44, wherein in the welding, the hardness of each of the electrode members and the hardness of the metal foil base plate are made substantially the same.   The metal according to any one of claims 34 to 36, wherein the metal foil tube is detached from the core rod by ejecting a fluid in the core rod in a radial direction and is removed. Manufacturing method of foil tube.   The said core rod is comprised from several members, The metal foil tube was made to peel from the said core rod by moving one part to an axial direction, The any one of Claims 34-37 characterized by the above-mentioned. 3. The method for producing a metal foil tube according to item 1.   The metal foil tube according to any one of claims 32 to 47, wherein a ratio of the thickness of the metal foil base plate to the inner diameter of the metal foil tube (plate thickness / inner diameter) is 1/500 or less. Manufacturing method.   A core metal is put into the metal foil tube obtained by the method according to any one of claims 32 to 48, and further cold-worked by swaging, split roller rolling, hole die, spatula drawing, or a combination of these methods. A method for producing a metal foil tube, comprising: reducing the thickness of a welded portion, smoothing the welded portion, adjusting the shape and surface roughness of the welded portion, and at least work hardening the material of the welded portion.   At least one of the two surfaces of the stainless steel foil is plated with a Group 10 to 11 element or an alloy containing at least one of these elements, or a metal having a melting point of 1200 ° C. or less, in the vicinity of at least one of the joints. The method for producing a metal foil tube according to any one of claims 32 to 49, wherein welding is performed.   The method for producing a metal foil tube according to any one of claims 32 to 50, wherein the foil tube to which the stainless steel foil is joined or further processed is heat-treated at a temperature of 800 to 1100 ° C.   The heat treatment of the foil tube which joined or formed further the stainless steel foil at the temperature of 800-1100 degreeC, Then, hard plating is applied to at least one of the inner surface and the outer surface of the foil tube. The method for producing a metal foil tube according to the above.   53. The method for producing a metal foil tube according to claim 50 or 52, wherein the plating composition is a Ni-P alloy containing 1 to 14% of P by weight.   Due to the welding of the metal foil tube, a continuous nugget (melted and solidified portion) along the weld line or an intermittent nugget at 50% or more along the weld line is present at the weld. A method for producing a metal foil tube according to any one of claims 32 to 53.   An apparatus for manufacturing a metal foil tube, comprising: a forming section for forming a metal foil sheet having a thickness of 10 to 100 μm into a predetermined shape; and a welding section for welding opposite sides of the metal foil sheet. The molding unit is a core rod having a circular cross section perpendicular to the axis, provided so as to be able to approach and separate from the core rod, a molding device for holding a metal foil base plate, and bringing the molding device closer to the core rod. At the point when the metal foil base plate and the core bar are in line contact, having a positioning member that presses the metal foil base plate and positions the core foil relative to the core bar,
56. The metal foil base plate approaching the core bar to the positioned metal foil base plate, and the metal foil base plate is previously wound in a U-shape around the core bar. Metal foil tube manufacturing equipment. The molding device is provided so as to be kept close to and separated from the core bar while always maintaining a position parallel to the core bar, and has a concave portion having a semicircular cross section around which the metal foil base plate is wound in a U-shape with the core bar. Plate, a first pressing member that presses one piece of the U-shaped metal foil element so as to be in close contact with the outer periphery of the core rod, and another piece of the U-shaped metal foil element sheet of the core rod. A second pressing member that presses toward the outer periphery,
57. The apparatus for manufacturing a metal foil tube according to claim 56, wherein after the winding, opposite ends of the metal foil base plate are overlapped to form an overlapped portion.   The forming part displaces a part of the circumference of the metal foil plate in the radial direction before the pressing by the second pressing member is completed, such that the overlapping margin of the overlapping part of the opposing sides becomes a predetermined value. 58. The apparatus for manufacturing a metal foil tube according to claim 56, further comprising an overlap margin adjusting unit.   59. The apparatus for manufacturing a metal foil tube according to claim 58, wherein the overlap margin adjusting means is constituted by an eccentric device provided inside the core rod.   59. The apparatus for manufacturing a metal foil tube according to claim 58, wherein the overlap margin adjusting means is constituted by an eccentric device provided outside the core bar.   59. The metal foil tube according to claim 58, wherein the overlap margin adjusting means presses a non-contact portion where the metal foil base plate is not in close contact with the core rod by a pressing member. apparatus.   59. The production of a metal foil tube according to claim 58, wherein the overlap margin adjusting means pushes a pressing member provided outside the core rod toward a concave portion formed in the core rod. apparatus.   63. The method according to claim 61 or 62, wherein the pressing member is any one of a cam, a roll, a cylindrical body, and a rod-shaped member, and is provided so as to individually operate at both axial end portions of the core rod. An apparatus for manufacturing a metal foil tube according to the above.   59. The apparatus for manufacturing a metal foil tube according to claim 57, wherein the overlap allowance (x) satisfies x ≦ 40 + 5t (unit is μm) as the plate thickness (t).   The apparatus for manufacturing a metal foil tube according to claim 55, wherein the welding is an electric resistance welding method.   The welding portion includes a conductive fixed electrode member provided on the outer surface of the core rod along the axial direction, and a movable electrode member provided to face the fixed electrode member. 55. The apparatus for manufacturing a metal foil tube according to claim 55, wherein the welding is performed in a state where the overlapped portion of the metal foil base plate is sandwiched between the metal foil base plates.   67. The apparatus for manufacturing a metal foil tube according to claim 66, wherein the fixed electrode member is formed such that a part or all of an outer surface thereof is a flat surface.   67. The apparatus for manufacturing a metal foil tube according to claim 66, wherein the movable electrode member is an electrode wheel that energizes the overlapping portion while applying pressure.   69. The apparatus for manufacturing a metal foil tube according to claim 66, wherein at least a part of each of the fixed electrode member and the movable electrode member is made of molybdenum or an alumina-dispersed copper alloy.   69. The apparatus for manufacturing a metal foil tube according to claim 66, wherein in the welding, the hardness of each of the electrode members and the hardness of the metal foil base plate are substantially the same.   The metal according to any one of claims 56, 57, and 66, wherein the metal foil tube is detached from the core rod by ejecting a fluid from the core rod in a radial direction, and is detached. Equipment for manufacturing foil tubes.   The apparatus for manufacturing a metal foil tube according to any one of claims 56, 57, and 66, wherein the core rod has a fluid passage for ejecting a fluid that separates the metal foil tube after welding from the core rod. .   70. The metal foil tube according to claim 56, wherein the core bar has a cutout on an outer peripheral surface thereof so that the metal foil base plate does not adhere to the core bar. apparatus.   The said core rod is comprised from several members, The metal foil tube was made to peel from the said core rod by moving one part to an axial direction, The any one of Claims 56, 57, 66 characterized by the above-mentioned. 3. The apparatus for manufacturing a metal foil tube according to claim 1.   75. The apparatus for manufacturing a metal foil tube according to any one of claims 55 to 74, wherein a ratio of a thickness of the metal foil base plate to an inner diameter of the metal foil tube is 1/500 or less.   A metal foil tube obtained by using the method for manufacturing a metal foil tube according to any one of claims 32 to 54 or the apparatus for manufacturing a metal foil tube according to any one of claims 55 to 75.

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