JP2007061877A - Method of manufacturing cylindrical article - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method by which a sound cylindrical article having no defect such as an unwelded zone or a kissing bond in the rear side of a weld zone can be favorably manufactured. <P>SOLUTION: A blank 10 is formed by press blanking of a prescribed plate material, wherein the blank 10 has projections 12a, 12b and 14a, 14b having a prescribed width and each protruding laterally from both sides at each end to be butted, and has a semicircular recess opened in the butting face of the projections 12a, 14a on one corresponding side at each end. Then, such blank is rolled up and both ends are butted against each other to form a cylindrical shape, and corresponding protrusions at both ends are butted against each other. During the above process, by the butting of the semicircular recesses, a circular inserting hole 16 is formed which becomes a starting end in friction stir welding. Then, the butting part 22 of the cylindrical formed body 20 so obtained is joined by friction stir welding using a bobbin tool type revolving tool that is set to the inserting hole 16. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a method for manufacturing a wheel rim for a wheel of a cylindrical article, for example, an automobile, a truck, a track vehicle, a hoist, a bicycle, a two-wheeled vehicle, etc., and in particular, a rim on the outer periphery of a two-piece wheel is joined by bending a plate. It is related with the manufacturing method.

  Conventionally, cylindrical articles have been used in various applications, for example, as a kind of wheel wheel for two-wheeled or four-wheeled vehicles, track vehicles, hoists, bicycles, etc., and has a rim made of an aluminum alloy, A wheel is known in which a disk, spokes, and the like are integrally provided on the rim. Since this aluminum alloy rim is excellent in lightness and formability, a vehicle wheel having such a rim is suitably used as a wheel for automobiles, motorcycles, bicycles and the like. It is.

  By the way, in general, cylindrical articles such as aluminum alloy rims in such a wheel for a wheel are first rolled into a cylindrical shape from a plate material made of a desired material such as a 5000 series aluminum alloy having excellent strength. , The butt portion to be abutted in the circumferential direction is welded and integrated by MIG welding, TIG welding, flash butt welding, DC butt welding or the like, and a tubular body is obtained. Although it is manufactured by molding into a shape, in the case of adopting this conventional method of manufacturing an aluminum alloy rim or the like, the joining of the butt portion of the aluminum alloy plate material that gives such a rim or the like is used as a material. From the point of fusion welding consisting of melting, after welding the butt, a large amount of In some cases, there was a possibility that a welding failure specific to fusion welding such as blowholes or oxide entrainment might occur in the weld. is there.

  For this reason, an aluminum alloy that gives a rim of an automobile wheel by applying a friction stir welding method, which is a kind of solid phase bonding, which has been attracting attention in recent years, and does not melt the material by heating and is bonded in a solid state. It is clarified in Japanese Patent Application Laid-Open No. 2004-181517 (Patent Document 1), Japanese Patent Application Laid-Open No. 2005-52884 (Patent Document 2), and the like that the plate members are bonded together. One method was clarified in the publication (Patent Document 3).

  That is, in a manufacturing method of a cylindrical article such as an aluminum alloy rim using this friction stir welding method, generally, first, a butt portion of an appropriate plate material such as a 5000 series aluminum alloy rolled into a cylindrical shape is first used. Then, a pin provided concentrically at the tip of the rod-shaped rotating jig is inserted while rotating together with the rotating jig and moved relatively, thereby generating frictional heat. The abutting part is made into a state that can be plastically processed, and the structure of the abutting part is mixed with the stirring action by high-speed rotation of the pin, so that the abutting parts are joined without melting, A predetermined tube is formed. Thereafter, the obtained tubular body is subjected to a straightening process for correcting the joint portion in an arc shape, and further, if necessary, the tubular body is formed into a predetermined shape to obtain a desired rim. A cylindrical article such as is obtained. Therefore, according to such a manufacturing method, when joining a butt portion of a predetermined plate material, since the butt portion is not melted at all, it is different from the case of melting and welding such a butt portion. As a result, rims having excellent bonding quality and strength can be advantageously suppressed. Cylindrical articles can be advantageously produced with a high production efficiency.

  However, the rotary tool used in such friction stir welding is generally a pin type tool having a pin having a length shorter by a predetermined dimension than the thickness of the plate material to be joined. Therefore, the metal cannot be sufficiently stirred in the portion where the pin does not reach the back surface side, and thus the pin cannot be penetrated, so that the back surface (inner surface of the cylindrical article) side of the joint portion is not In some cases, a joint or kissing bond may remain, which may reduce fatigue strength. In addition, such a bonding failure has a problem that it is difficult to detect since it is formed inside the cylindrical article.

  On the other hand, US Pat. No. 6,1997,745 (Patent Document 4), JP 7-505090 A (Patent Document 5), Japanese Patent Application Laid-Open No. 2004-42115 (Patent Document 6), etc. As the rotary tool, a bobbin type tool (pincushion type tool) or a bobbin tool type rotary tool having a structure different from the above-described pin type tool has been clarified. Such a rotary tool is generally provided coaxially between two shoulder members that provide a pair of shoulder surfaces facing each other so as to sandwich a plate material to be joined, and the two shoulder members. And a pin for connecting them. Also, there, frictional heat is generated on each surface by rotating the shoulder member and the pin integrally at high speed while pressing the surfaces on both sides so that the plate material is sandwiched between the two shoulder members. Can be done. For this reason, if friction stir welding is performed using such a bobbin type tool, the inner surface of the cylindrical article can also be reliably bonded, and hence the occurrence of a bonding failure such as a kissing bond as described above occurs. Since the pair of shoulder members receive (support) each other's pressing force, the advantage that the backing member is unnecessary can be enjoyed. is there.

  However, when such a friction stir welding tool (bobbin type tool) is used for friction stir welding of a butt portion of a plate material rolled into a cylindrical shape, the joining start end of the cylindrical shape is rolled. There is a problem that it is difficult to provide the plate material in terms of location and work, and in addition, problems such as scattering of materials and generation of burrs occur in the area around the starting end. Since the joint start and end ends inevitably remain in the joint product, it is necessary to cut off the joint start end, so that cylindrical products such as wheel rims that are joined individually one by one. Then, the cutting and removal allowance increases, and there is a problem that causes a large loss of material. In addition, problems such as time and labor required for cylindrical cutting after joining are inherent.

JP 2004-181517 A JP 2005-52884 A JP 2003-230970 A US Pat. No. 6,1997,745 JP 7-505090 Gazette JP 2004-42115 A

  Here, the present invention has been made in the background of such circumstances, and the problem to be solved is a healthy cylinder free from defects such as an unjoined portion or a kissing bond on the back surface of the joined portion. It is an object of the present invention to provide a method by which a shaped article can be produced advantageously.

  In the present invention, in order to solve such a problem, a plate-shaped material having a predetermined rectangular shape as a whole is rounded into a cylindrical shape and both end portions thereof are butted, and then the butted portion. When manufacturing an integral cylindrical article by friction stir welding, (a) as the plate material, projecting portions with a predetermined width projecting sideways on both sides of each end to be abutted. A blank material having a semicircular recess that opens on the abutting surface of the corresponding one side protrusion portion of each end portion is formed by press punching a predetermined plate material, and prepared And (b) rolling the blank material, butting both ends of the blank, making it cylindrical, but matching the corresponding protrusions at each end, and providing the protrusions on the one side And a step of forming a circular insertion hole serving as a starting end of the friction stir welding by butting the corresponding semicircular recesses, and (c) the butt portions of the blank material are arranged to face each other. A bobbin tool type rotary tool having a pair of shoulder members and a pin member disposed coaxially between the pair of shoulder members is used, and the pin member of the rotary tool is formed at the abutting portion of the protruding portion. After being set in a state of being inserted into the insertion hole, the abutting portion is frictionally stirred and joined by rotating the rotary tool and relatively moving along the abutting portion. The gist of the present invention is a method for producing a cylindrical article characterized by including the step of reaching the butted portion of the protruding portion on the opposite side.

  In addition, according to one of the preferable aspects of the manufacturing method of the cylindrical article according to the present invention, the blank material corresponding to the blank material is provided on at least one side of both ends to be abutted by the press punching operation. A projecting portion is formed on one of the butting surfaces of the projecting portion, and a recess is formed on the other, and the mating positions of the projecting portion and the recessed portion are configured to fix the butting positions of both end portions of the blank material.

  In the present invention, advantageously, the blank material is formed by press punching of an aluminum alloy sheet, while a wheel rim for a wheel is manufactured as the cylindrical article.

  According to such a method for manufacturing a cylindrical article according to the present invention, a so-called bobbin tool type having a structure capable of generating frictional heat on both sides of a butt portion of a blank material rolled into a cylindrical shape, respectively. Since the rotary tool is used as a friction stir welding tool, sufficient plasticization is realized even on the back side (cylindrical inside) of the butt portion, and the occurrence of unjoined parts or kissing bonds is effective. In addition, the friction stir welding operation using such a bobbin tool type rotary tool can be advantageously performed by using a blank material having a specific shape. It is.

  That is, in the present invention, on both sides of the butt end portion of the blank material to be rounded, a projecting portion having a predetermined width projecting laterally is provided, and further, the projecting on one side corresponding to each end portion is provided. Tabs that can be used as the starting end of friction stir welding on the side of the butt when the blank is rolled up by providing a semicircular recess that opens in the butt surface of each part. A board part will be formed by two corresponding protrusion parts which were faced | matched, respectively. Then, in one of the tab plate portions, a circular insertion hole serving as a starting end of friction stir welding is formed by abutting the corresponding semicircular recesses. In the state where the pin member of the bobbin tool type rotary tool is inserted, the friction stir welding operation by such a bobbin tool type rotary tool can be effectively performed, By starting the friction stir welding operation from one of the tab plate portions located on both sides of the butting portion and ending such friction stir welding operation on the other tab plate portion, the processing of the start and end of the joining is also possible. Since it is only necessary to cut and remove the tab plate parts on both sides, the problem of material loss in the joined product and the problem of cutting and removing work are also effective. Than it can be relaxed.

  Moreover, since the blank material having such a specific shape is formed by press punching of a predetermined plate material, the pin member of the bobbin tool type rotary tool is inserted and becomes the start end of the friction stir welding. In addition to the semicircular recess that provides a circular insertion hole, both sides of the butt end can also be formed with protrusions that protrude laterally at the same time as the blank material body. Therefore, it is possible to advantageously obtain a material to be used for friction stir welding in order to manufacture a cylindrical article, which can greatly contribute to simplification of the manufacturing process.

  Hereinafter, in order to clarify the present invention more specifically, embodiments of the present invention will be described in detail with reference to the drawings.

  First, FIG. 1 shows an example of a blank material used in the method for manufacturing a cylindrical article according to the present invention in a plan view in which an intermediate portion is omitted. In this case, the blank 10 is made of a plate material of a predetermined size that gives a target cylindrical article and has a rectangular shape as a whole, and is abutted when it is rolled into a cylindrical shape, FIG. Are provided with protruding portions 12a, 12b; 14a, 14b having predetermined widths protruding laterally by a predetermined length on both sides of the corresponding upper and lower ends. Here, the sizes of the projecting portions 12a and 12b; 14a and 14b are appropriately determined according to the size of the tab plate portions (24a and 24b) formed by the butting. Then, the projecting portions 12a and 14a on the corresponding one side (left side in FIG. 1) of each of the end portions of the blank material 10 to be abutted have semicircular shapes so as to open to their abutting surfaces, respectively. Recesses 16a and 16b are provided.

  In addition, as a material of such a blank material 10, it selects suitably according to the target cylindrical article, for example, the aluminum member which consists of aluminum or an aluminum alloy, the copper member which consists of copper or a copper alloy, magnesium, or In addition to metal members such as magnesium members made of a magnesium alloy, various known materials that can be friction stir welded can be used. Among them, when a wheel rim for a wheel is used as a cylindrical article, a 5000 series aluminum alloy is preferably used.

  In addition, as is well known, the blank material 10 can generally be easily manufactured in one step by punching a predetermined plate material in the same manner as in the past by a press operation. . Of course, in order to obtain the blank material 10, it is possible to combine a plurality of pressing processes into a blank material having a desired outer shape, but in any case, by press punching a predetermined plate material, FIG. Can be formed, in particular, in which there are two sets of protrusions 12a, 12b; 14a, 14b and semicircular recesses 16a, 16b together with the body of the blank 10, It will be formed by press punching.

  Then, using the blank material 10 obtained in this way, as shown in FIG. 2, it is left with a predetermined width portion at both ends to be abutted by a known technique such as roll processing (roll forming). Then, it is bent (rounded) into a cylindrical shape to form the cylindrical molded body 20 in a form in which both ends are butted in the circumferential direction. Thus, in the cylindrical molded body 20, a butt portion 22 is formed by butting both ends of the blank material 10, and the butt portion 22 extends in the axial direction of the cylindrical molded body 20. It has become. Further, since both end portions of the blank material 10 to be abutted in the circumferential direction have flat portions with a predetermined width on both sides with the abutting portion 22 in between, a friction stir welding operation described later is easily performed. To get. In addition, by forming the cylindrical molded body 20, the protruding portions 12a, 14a and 12b, 14b provided on both sides of the butt end portion are combined to form tab plate portions 24a, 24b, respectively, In the tab plate portion 24a, the start end of the friction stir welding as described later is caused by abutment of the semicircular recesses 16a and 16b provided on the abutment surfaces of the two abutment projections 12a and 14a. Thus, the circular insertion hole 16 is formed. Further, the size of the insertion hole 16 is determined so as to have a diameter as small as possible so that a pin member (30) of a bobbin tool type rotary tool (31) described later can be inserted.

  In the present invention, the bobbin tool type rotary tool 31 is used for friction stir welding of the butt portion 22 of the cylindrical molded body 20 as described above. As shown in FIG. 3, the bobbin tool type rotary tool 31 has a pair of shoulders arranged so as to face each other so that the butting portion 22 of the blank 10 (cylindrical shaped body 20) can be sandwiched from both the upper and lower (inner and outer) sides. The members 26, 28 and a pin member 30 disposed coaxially between the shoulder members are configured. Specifically, here, the shoulder member 26 positioned above in the drawing has a cylindrical shape as a whole, and is a shoulder surface 26a composed of a flat annular surface whose front end surface extends in the horizontal direction. . Further, the shoulder member 28 positioned below has a thick disk shape as a whole, and a rod-shaped pin member 30 attached perpendicularly to the center of the shoulder member 28 penetrates the center hole of the shoulder member 26, The two shoulder members 26 and 28 and the pin member 30 are arranged so as to be rotatable at high speed around the axis. Further, a surface on the shoulder surface 26a side of the other shoulder member 26 of the shoulder member 28 is a shoulder surface 28a having the same outer diameter and inner diameter as the shoulder surface 26a and comprising a flat annular surface extending in the horizontal direction. Yes.

  When the abutting portion 22 of the cylindrical molded body 20 is friction stir welded using the bobbin tool type rotary tool 31 having such a configuration, the end portions of the butted portion 22 of the cylindrical molded body 20 are joined to each other. In the state where the pin member 30 of the rotary tool 31 is inserted into the circular insertion hole 16 formed in one of the two tab plate portions 24a and 24b positioned, the two shoulder members 26 and 28 are relative to each other. The tab plate portion 24a is sandwiched between the shoulder surfaces 26a and 28a so as to come into contact with the front surface (outer surface) and the back surface (inner surface) of the tab plate portion 24a. , The shoulder members 26 and 28 and the pin member 30 are rotated at high speed around their axes to generate frictional heat. The target friction stir welding operation is performed by relatively moving the rotary tool 31 along the abutting portion 22 toward the other tab plate portion 24b with the insertion hole 16 as the start end of the friction stir welding. As shown in FIG. 4, the joining portion 32 in the form in which the friction stir zone is exposed on the surface is formed on the inner surface (back side) of the cylindrical molded body 20, as shown in FIG. 4. It is formed on the rear side in the traveling direction. Then, the friction stir welding operation using the rotary tool 31 is terminated after the rotary tool 31 reaches the other tab plate portion 24b in which the insertion hole 16 is not provided.

  In addition, in such a friction stir welding operation for the cylindrical molded body 20, the cylindrical shape of the arc-shaped portion excluding the flat portion in the vicinity of the butt portion 22 of the cylindrical molded body 20 can be maintained during the bonding operation. In addition, the arc-shaped portion of the cylindrical molded body 20 is restrained from the outside by a predetermined restraining jig as in the conventional case. At this time, as in the case of using a conventional pin type rotary tool. The backing jig is not disposed inside the cylindrical molded body 20. As a reaction force of the pressing force by the upper shoulder member 26 in the bobbin tool type rotary tool 31 used here, the lower shoulder member 28 presses the butting portion 22 from the inner side (back side) of the cylindrical molded body 20. Because it is.

  Thereafter, the friction stir welding product of the cylindrical molded body 20 thus obtained is subjected to a process of cutting off the tab plate portions 24a, 24b on both sides protruding in the axial direction from the cylindrical main body portion, The joining start end and end end, which are undesirable defects in the friction stir welding operation, are advantageously removed from the joined product while stopping the material loss at the tab plate portions 24a, 24b.

  Further, in such a bonded product, if necessary, the bonded portion 32 is polished, and the flat bonded portion 32 is rounded so as to have the same curvature as the arc shape of other portions. The straightening process for forming and correcting in an arc shape is performed by a known forming technique such as roll processing. As a result, a cylindrical product having no dents as a whole can be obtained. In addition, it goes without saying that conventionally known methods can be appropriately employed for such processing such as correction processing and conventional finishing processing depending on the target cylindrical article. .

  Thus, according to the above-described embodiment, the abutting portion 22 of the cylindrical molded body 20 is friction stir welded by the bobbin tool type rotary tool 31 from both sides, as shown in FIG. Also, on the back side (inside), an effective friction stir zone can be formed, and a sound bonded product without occurrence of defects such as unbonded cracks or kissing bonds can be obtained. For friction stir welding by the bobbin tool type rotary tool 31, the start end and the end end are tab plate portions 24a configured by protrusions 12a, 12b; 14a, 14b provided integrally with the blank material 10, In addition to being able to dispose of the start end and end end of the joint only by excision of the tab plate portions 24a, 24b by being positioned at 24b, The blank material having a specific shape can be skillfully formed by press punching a predetermined plate material, so that the manufacturing process of the intended bonded product, and thus the cylindrical article can be effectively simplified. It is.

  The exemplary embodiments of the present invention have been described in detail above. However, the embodiments are merely examples, and the present invention is limited in any way by specific descriptions according to such embodiments. It should be understood that it is not interpreted.

  For example, in the cylindrical molded body 20 obtained by rounding the blank material 10 and butting both end portions thereof, the butted portion 22 projects from the blank material 10 as shown in FIG. Convex portions 34a and 34b are integrally provided on one of the projecting portions 12a and 12b, respectively, while the other projecting portions 14a and 14b are concave portions having shapes corresponding to the projecting portions 34a and 34b. 36a and 36b are provided, and when the projecting portions 12a and 14a and 12b and 14b are brought into contact with each other, the projecting portions 34a and 34b and the recessed portions 36a and 36b are respectively fitted with projections and recesses, and the blank 10 In order to facilitate the subsequent friction stir welding operation, it is possible to fix the abutting position of both rounded ends of the steel plate. It is effective. And these convex part 34a, 34b and recessed part 36a, 36b can be simultaneously formed by the press punching operation of the blank material 10, and after the end of the friction stir welding operation, the tab plate part 24a, By cutting 24b, it is possible to remove from the bonded product along with the beginning and end of the bond.

  When the friction stir welding operation according to the present invention is terminated at the tab plate portion 24b on the side where the insertion hole 16 is not provided, the movement of the rotary tool 31 is stopped on the tab plate portion 24b. It is also possible to stop the operation of the rotary tool 31 at the position where the tab plate portion 24b abuts, in other words, the position where it protrudes outward from the abutting portion of the protrusions 12b and 14b. A through hole similar to the insertion hole 16 may be formed in the tab plate portion 24b on the side, and the friction stir welding operation may be stopped when the rotary tool 31 reaches the through hole portion. It is.

  Furthermore, as shown in FIG. 3, the bobbin tool type rotary tool used in the present invention has a pair of shoulder members 26, 28 with a butting portion 22 sandwiched therebetween, and the pair of shoulder members 26. , 28 having a pin member 30 for coaxially connecting the shoulder members 26, 28 and the pin member 30, any known rotary tool can be used. Even if the shoulder surfaces 26a and 28a of the pair of shoulder members 26 and 28 are opposed to each other, not only a flat surface but also a concave shape that curves toward the center can be used. Conventionally known shapes can be appropriately employed.

  In addition, although not listed one by one, the present invention can be implemented in a mode with various changes, modifications, improvements, and the like based on the knowledge of those skilled in the art. It goes without saying that any one of them falls within the scope of the present invention without departing from the spirit of the invention.

  Hereinafter, representative examples of the present invention will be shown to clarify the present invention more specifically, but the present invention is not limited by the description of such examples. It goes without saying.

Example 1
First, a plate material (O material) of JIS5454 aluminum alloy having a thickness of 4 mm is prepared, and a pipe having an outer diameter: 400 mm and a length: 500 mm is provided from this plate material, as shown in FIG. A blank material having a protrusion at each end and a semicircular recess at the corresponding protrusion was produced by outline punching by a normal press punching operation.

  Then, the blank material is bent into a cylindrical shape by a known roll process, and both end portions formed integrally with protrusions on both sides in the width direction are butted against each other in the circumferential direction, and the cylindrical shape as shown in FIG. A formed body (outer shape: 400 mm, length: 500 mm) was formed. In addition, as shown in FIG. 3, the pin member of the rotary tool can be inserted with a slight gap into one of the two tab plate portions formed on both sides of the butt portion of the cylindrical molded body. An insertion hole having an extremely small hole diameter is formed. The obtained cylindrical molded body was fixed from the outside with a known restraining jig so that the cylindrical shape was maintained.

  Then, using a steel rotating tool having a structure as shown in FIG. 3, the pin member is inserted into an insertion hole corresponding to the pin diameter provided in advance in the tab plate portion of the cylindrical molded body, and further separated on the back side. After the shoulder member is positioned and fixed to the tip of the pin member, the rotary tool is rotated at a high speed to start friction stir welding, and the cylinder is rotated at a rotation speed of 1500 rpm and a welding speed of 500 mm / min. The friction stir welding operation was advanced by moving along the butted portion of the shaped molded body, and the friction stir welding operation was terminated when the other tab plate portion was reached.

  The joint product obtained in this way can be easily removed by cutting off the tab plate portions because the joint end portions are present on the tab plate portions at both ends of the joint portion. Moreover, no cracks are observed on the back side (inner side) of the joint, and the sound is healthy and no inconvenience is caused in the subsequent wheel manufacturing process. That is, the pipe-shaped joined product obtained above was spun into a wheel shape, and a wheel was produced by inserting a disk and joining by arc welding. However, there was no inconvenience in the production process. Was also not recognized.

Example 2
In order to obtain a cylindrical molded body as shown in FIG. 5, the blank material 10 in which the butted shape of the projecting portion of the tab plate portion was changed was obtained by the outer shape punching process by the press punching operation in the same manner as in Example 1.

  Next, the obtained blank is rolled into a pipe having an outer diameter of 400 mm and a length of 500 mm, both ends thereof are butted into a cylindrical molded body, and the outer periphery thereof is made the same as in the conventional case. And restrained so that the cylindrical shape can be maintained during the joining, because the tab plate portion was positioned by concave-convex fitting at the time of butting, the restraint was easy, The gap was able to be suppressed within 0.1 mm.

  Thereafter, the constrained cylindrical molded body was subjected to friction stir welding in the same manner as in Example 1 using a rotating tool made of a steel shoulder member and a pin member as shown in FIG. Thus, a sound bonded product (pipe) free from defects such as cracks on the back side of the bonded portion could be obtained advantageously.

It is plane explanatory drawing in which the intermediate part was abbreviate | omitted which shows an example of the blank material used in this invention. It is a perspective explanatory view which shows the cylindrical molded object obtained by rolling the blank material shown by FIG. It is front part explanatory drawing which shows an example of the bobbin tool type rotary tool used in this invention. It is a perspective partial explanatory view showing the friction stir welding state according to the present invention. It is explanatory drawing which looked at the butt | matching part from the front about the cylindrical molded object obtained using the other example of the blank material according to this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Blank material 12a, 12b; 14a, 14b Projection part 16 Insertion hole 16a, 16b Recess 20 Cylindrical molded body 22 Butt part 24a, 24b Tab board part 26, 28 Shoulder member 26a, 28a Shoulder surface 30 Pin member 31 Rotating tool 32 Joints 34a and 34b Convex parts 36a and 36b Concave parts

Claims (3)

When manufacturing an integral cylindrical article by rounding a plate-shaped material of a predetermined size, which has a rectangular shape as a whole, into a cylindrical shape, butting both ends thereof, and then friction-stir-joining the butted portions,
As the plate-like material, each of the end portions to be abutted has a projecting portion with a predetermined width projecting laterally on each side, and each of the end portions has a corresponding projecting portion on one side of the projecting surface. Forming a blank material having a semicircular recess to be opened by press punching a predetermined plate material;
The blank material is rounded, its both end portions are butted to make a cylindrical shape, and the corresponding projecting portion at each end is butted, and the corresponding semicircular recess provided on the one side projecting portion A step of forming a circular insertion hole serving as a starting end of the friction stir welding by the butt,
Using a bobbin tool type rotary tool provided with a pair of shoulder members arranged so as to sandwich the butting portion of the blank material and a pin member disposed coaxially between the pair of shoulder members After setting the pin member of the tool in a state of being inserted into the insertion hole formed in the abutting portion of the projecting portion, by rotating the rotating tool and relatively moving along the abutting portion, , The step of friction stir welding the butted portion to reach the butted portion of the protruding portion on the opposite side of the one side,
A manufacturing method of a cylindrical article characterized by including.   By the blanking operation of the blank material, a convex portion is formed on one of the butting surfaces of the corresponding projecting portion provided on at least one side of the both ends to be abutted, and a concave portion is formed on the other. The method for manufacturing a cylindrical article according to claim 1, wherein the butted positions of both end portions of the blank material are fixed by fitting the portion and the concave portion. The manufacturing method of the cylindrical article according to claim 1 or 2, wherein a wheel rim is manufactured as the cylindrical article while the blank is formed by press punching of an aluminum alloy sheet.

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