JP4374274B2 - Friction stir welding method - Google Patents

Description

The present invention is, depending on the thickness of the workpiece to be Hodokoso machining, or displaced or selection of friction stir welding tool having suitable dimensions as a probe, or a roller for curving at the right displacement The present invention relates to a friction stir welding method for performing appropriate friction stir welding .

  For example, end faces of two plate materials are brought into contact with each other, and friction stir welding is widely performed at a corresponding contact portion with a friction stir welding tool. In this friction stir welding, a probe provided at the tip of the friction stir welding tool is buried in the contact location, and then the probe is linearly displaced along the contact location.

  When a plurality of identical products are continuously manufactured, the friction stir welding described above is repeatedly performed on separate plate materials. However, in this case, while there are products in which the contact portions are firmly bonded, there are some products whose bonding strength is not good because bonding defects such as unbonded portions remain.

  One reason for this is presumed to be that the thickness of the plate material varies within a tolerance range. That is, for example, if the actual thickness of a plate having a nominal thickness of 3.0 mm is 3.0 ± 0.1 mm, the thickness of the smallest plate is 2.9 mm, and the thickness of the largest is 3.1 mm. As can be understood from this, even if the same plate material has a nominal thickness of 3.0 mm, there may be a maximum thickness difference of 0.2 mm when the plate materials are compared.

  Therefore, the friction stir welding tool capable of satisfactorily friction stir welding plate materials having an actual thickness of 3.0 mm, and friction stir welding of plate materials having an actual wall thickness of 2.9 mm. When trying to do so, the probe tip surface buried in the contact portion and the lower end surface of the contact portion are relatively separated from each other. For this reason, even if the probe is rotated, the meat in the vicinity of the lower end surface is not sufficiently agitated.

  Moreover, in the bending process which roll-forms a board | plate material in cylindrical shape, it originates in the thickness of a workpiece | work being different, and the dimensional accuracy of a product falls. This is because the spring back generated in the workpiece having a small thickness is larger than that in the workpiece having a large thickness.

  In this way, in various machining processes, the thickness of the workpiece is different even though it is within the tolerance range, so that it is difficult to say that the bonding strength is sufficient, and products with poor dimensional accuracy are produced. This causes a malfunction.

  In order to solve such a problem, in the case of friction stir welding, the friction stir welding tool is configured as described in Patent Document 1, and the protruding amount of the probe is changed according to the thickness of the plate material. It is also conceived that the friction stir welding tool is displaced during the friction stir welding so that the amount of burying of the probe is constant (see Patent Document 2). Patent Document 3 proposes preparing a processing means based on the shape of a plate material in roll forming.

JP-A-10-71478 Japanese Patent No. 3314706 JP 2000-225418 A

  However, when a friction stir welding tool is configured as described in Patent Document 1, the tool body and the probe are separate members, so the number of components of the friction stir welding tool increases. Further, since a mechanism for projecting / withdrawing the probe and a control means for controlling the projecting / withdrawing amount are required, the configuration of the friction stir welding apparatus becomes complicated and there is an inconvenience that the cost is increased.

  Further, the apparatus described in Patent Document 2 also requires measuring means for measuring the distance from the friction stir welding tool to the workpiece, and control means for controlling the ascending / descending operation of the friction stir welding tool and its displacement amount. It becomes. Therefore, the configuration of the friction stir welding apparatus becomes complicated as in the above, and the cost increases.

  Furthermore, Patent Document 3 is a technique related to variously changing the position of a forming roll (die) based on the thickness of a workpiece, which is a raw material, for the purpose of obtaining final products having various dimensions. When the thickness is different within the tolerance range, the position of the forming roll is not changed, so that a product with good dimensional accuracy cannot be obtained continuously.

The present invention has been made to solve the above-described problems, and various kinds of machining can be reliably performed on the workpiece without complicating the apparatus configuration. For this reason, friction that is difficult to cause machining defects is achieved. It aims at providing the stirring joining method.

In order to achieve the above object, the present invention provides a probe having a dimension corresponding to the thickness of each workpiece that differs within a tolerance range from a reference value when individually performing friction stir welding on a plurality of workpieces. select a friction stir welding tool having, a FSW method of performing friction stir welding at said friction stir welding tool,
A plurality of the workpieces, a thick group whose thickness is from the reference value to the maximum allowable value within the tolerance range, and a thin wall group whose thickness is from the reference value to the minimum allowable value within the tolerance range And separated
A first median value that is an intermediate value between the reference value and the maximum allowable value, and a second median value that is an intermediate value between the reference value and the minimum allowable value;
While the first friction stir welding tool having a probe having a dimension corresponding to the thickness of the first median value is selected as the friction stir welding tool for the thick wall group, the first median thickness according to the thickness of the second median value A second friction stir welding tool having a probe of a different size is selected as the friction stir welding tool for the thin-walled group ,
Friction stir welding is performed with the first friction stir welding tool for the thick-walled group, and friction stir welding is performed with the second friction stir welding tool for the thin-walled group .

  That is, according to the present invention, workpieces are classified into a thick wall group and a thin wall group according to the thickness, and workpieces belonging to the thick wall group can be processed with workpieces whose thickness is an intermediate value of the thick wall group. It is machined by a machining tool having a machining site of various dimensions. On the other hand, a workpiece belonging to the thin group is processed by a processing tool having a processing portion having a dimension capable of processing a workpiece whose thickness is an intermediate value of the thin group.

  In this way, the workpieces are separated according to the wall thickness, and the workpiece is selected from the thick wall group or the thin wall group by selecting the processing tool based on the intermediate value of each wall thickness after the separation instead of the nominal wall thickness. In any case, it can be processed into a product having a predetermined dimensional accuracy.

  In addition, in this case, when preparing a machining tool having a machining part with a dimension corresponding to each of those whose thickness is the median tolerance, what is the lower limit of the tolerance, and what is the upper limit of the tolerance As compared with the above, the number of machining tools is reduced. Therefore, the processing cost can be reduced.

When the workpiece is a plate material, and the plate material is friction stir welded to the end surfaces that are curved and abutted in a cylindrical shape, a plurality of rollers can be displaced with a roller displaceable prior to the friction stir welding. When performing the bending process individually, when performing the bending process on the thick wall group, the displacement amount of the roller is set as the first displacement amount according to the thickness of the first median value, When bending the thin wall group, the displacement amount of the roller is set as a second displacement amount according to the thickness of the second median value,
While performing the bending process with the first displacement amount for the thick-walled group, performing the bending process with the second displacement amount for the thin-walled group to bring the end surfaces of the plate members into contact with each other,
Thereafter, the friction stir welding may be performed with respect to the end surfaces in contact with each other .

Also in this case , according to said definition , a workpiece | work is divided into a thick group and a thin group according to thickness. The workpiece belonging to the thick wall group is processed by a roller displaced to a position where the workpiece whose thickness is an intermediate value of the thick wall group can be processed, while the workpiece belonging to the thin wall group has the thin wall thickness. The workpiece, which is an intermediate value of the group, is processed by a roller displaced to a position where it can be processed.

In this way, the workpiece is separated according to the wall thickness, and the workpiece is divided into either the thick wall group or the thin wall group by displacing the roller based on the intermediate value of each wall thickness after the separation instead of the nominal wall thickness. Even if it belongs, it can be processed into a product having a predetermined dimensional accuracy.

  Moreover, in this case, compared to the case where the wall thickness is the median tolerance, the tolerance lower limit, or the tolerance upper limit, the machining tool is displaced by an individually corresponding displacement amount. The advantage that the program for displacement amount control is simplified can be obtained.

According to the present invention, the friction stir welding tool is selected according to the thickness of the workpiece, or the amount of displacement of the bending roller performed prior to the friction stir welding is adjusted. Therefore, in this case, the apparatus configuration is not complicated.

  In addition, since it is easy to machine the workpiece with dimensional accuracy, machining defects are less likely to occur.

Preferred embodiments of the friction stir welding method according to the present invention will be described below in detail with reference to the accompanying drawings.

The friction stir welding method according to the present embodiment can be employed, for example, when producing a wheel rim that constitutes a wheel of a four-wheeled vehicle. Here, the wheel rim has a step of manufacturing the cylindrical body W2 shown in FIG. 2 by joining the end faces of the substantially rectangular workpiece W1 shown in FIG. A step of forming a drop portion that is depressed toward the peripheral wall side, a step of forming a curl portion at both ends of the cylindrical body W2, and a step of raising a part of the outer peripheral wall of the cylindrical body W2 to form a hump portion And a step of forming a valve hole and a drain hole. The wheel rim and the separately manufactured wheel disc are joined to manufacture the wheel.

  First, as shown in FIG. 1, the first and second convex portions 10a and 10b, the third convex portion 10c and the fourth convex portion 10d extending along the joining direction (arrow A direction) are connected to each corner. A workpiece W1 at the corner is cut out from a sheet body having a nominal wall thickness of 3.0 mm.

  Since the actual thickness of the workpiece W1 having a nominal thickness of 3.0 mm varies within the tolerance range as described above, it is 2.9 to 3.1 mm. Therefore, the actual thickness of the cut workpiece W1 is individually measured. This measurement may be performed using, for example, a micro gauge.

  If the nominal wall thickness of 3.0 mm is sorted as a reference value, the plurality of workpieces W1 are divided into a thin wall group having a wall thickness of 2.9 to 3.0 mm and a thick wall group having a wall thickness of 3.0 to 3.1 mm. And classified. In addition, you may classify | categorize the workpiece | work W1 whose actual thickness is 3.0 mm of nominal thickness into either a thin group or a thick group.

  And if the median value of 2.9 to 3.0 mm which is the thickness range of the thin group and the median value of 3.0 to 3.1 mm which is the thickness range of the thick group are respectively calculated, 2.95 mm and 3.05 mm.

  In this way, after separating the workpiece W1 into a thin group and a thick group, the two lower forming rolls 20 and 22 shown in FIG. In a roll forming apparatus having a total of three forming rolls 20, 22, and 24, the first convex portion 10a and the second convex portion 10b, and the third convex portion 10c and the fourth convex portion 10d are in contact with each other. Next, it curves along the direction of arrow B in FIG.

  Here, when the clearance CL between the lower forming rolls 20 and 22 and the upper forming roll 24 is unchanged with a nominal thickness of 3.0 mm as a reference value, when the workpiece W1 belonging to the thin wall group is curved, A minute gap is generated between the workpiece W1 and the forming rolls 20, 22, and 24. For this reason, the workpiece W1 is not sufficiently curved, and in some cases, the first convex portion 10a and the second convex portion 10b, the third convex portion 10c and the fourth convex portion 10d do not come into contact with each other, but the distance is small. May be separated.

  On the other hand, when the workpiece W1 belonging to the thick wall group is bent, the workpiece W1 is excessively pressed by the forming rolls 20, 22, and 24, and therefore the workpiece W1 is excessively bent. As a result, the second convex portion 10b is laminated on the first convex portion 10a and the fourth convex portion 10d is laminated on the third convex portion 10c, or vice versa. The first protrusion 10a may be stacked on the second protrusion 10b, and the third protrusion 10c may be stacked on the fourth protrusion 10d.

  In order to avoid such a situation, in the present embodiment, when roll forming the workpiece W1 belonging to the thin group, the reference value is 2.95 mm, which is an intermediate value of the thickness width of the thin group. I am doing so. Specifically, the forming rolls 20, 22, and 24 are displaced, and the clearance CL between the lower forming rolls 20 and 22 and the upper forming roll 24 is set between the end faces of the workpiece W1 having a thickness of 2.95 mm. The distance is set such that a pressing force necessary to bend to the extent of contact can be applied.

  In this case, even if the thickness of the workpiece W1 is other than 2.95 mm, the thickness difference compared to 2.95 mm which is an intermediate value of the thickness width is within 0.05 mm. If the wall thickness difference is about this level, the workpiece W1 belonging to the thin wall group is bent with an appropriate pressing force even when roll forming is performed on the basis of 2.95 mm. As a result, the end surfaces of the workpiece W1 can be brought into contact with each other.

  On the other hand, when roll forming a thick group, the forming rolls 20, 22, and 24 have a wall thickness of 3.05 mm with a reference value of 3.05 mm which is an intermediate value of the thickness width of the thick group. The clearance CL is displaced so as to increase to a position where a pressing force necessary to bend to such an extent that the end surfaces of the workpiece W1 are brought into contact with each other can be applied.

  Even in this case, the difference in thickness between the actual thickness of the workpiece W1 and 3.05 mm, which is an intermediate value of the thickness width of the thick group, is within 0.05 mm. If the wall thickness difference is about this level, the workpiece W1 belonging to the thick wall group is bent with an appropriate pressing force even when roll forming is performed with 3.05 mm as a reference. As a result, the end surfaces of the workpiece W1 can be brought into contact with each other without being stacked.

  As described above, when the workpiece W1 is divided into the thin wall group and the thick wall group and the workpiece W1 belonging to the thin wall group is curved, the intermediate value of the thickness width of the thin wall group is 2.95 mm. When bending the workpiece W1 belonging to the thick wall group, the end face of the workpiece W1 is displaced by displacing the forming rolls 20, 22, and 24 with reference to 3.05 mm which is an intermediate value of the thickness width of the thick wall group. The two can be reliably brought into contact with each other. As a result, as shown in FIG. 2, the first protrusions 28a are formed by the first protrusions 10a and the second protrusions 10b, and the second protrusions are formed by the third protrusions 10c and the fourth protrusions 10d. Part 30 is formed.

  Then, in the next step, the contacted end faces of the workpiece W1 are joined by friction stir welding, and a cylindrical body W2 shown in FIG. 2 is produced. In this friction stir welding, the workpiece W1, that is, the first projecting portion 28 and the second projecting portion 30 of the cylindrical body W2, are respectively supported by jigs (not shown). This support prevents the contacted end faces from being separated from each other.

Next, friction stir welding is performed on the cylindrical body W2 obtained by the above bending process.

  As shown in FIG. 4, the friction stir welding tool 40 includes a columnar rotating body 42 fixed to a spindle of a friction stir welding apparatus (not shown), and a first part of the workpiece W1 provided on the tip of the rotating body 42. It has the probe 44 buried in the contact | abutting location of the 1 convex part 10a and the 2nd convex part 10b. Usually, as the friction stir welding tool 40, a tool having a probe 44 having a length that does not cause an unjoined portion on the workpiece W1 having a nominal thickness with a nominal thickness of 3.0 mm as a reference is selected. Then, regardless of the thickness of the workpiece W1, the distance (gap) G between the probe 44 buried from the outer peripheral wall side of the workpiece W1 and the lower end surface on the inner peripheral wall side of the workpiece W1 is kept constant. Friction stir welding is performed.

  However, as shown in FIG. 4, when the friction stir welding is performed on the workpiece W1 belonging to the thin wall group, the rotating body 42 and the workpiece W1 are separated from each other. As a result, the protruding portion 46 is formed in the vicinity of the buried portion of the probe 44.

  On the other hand, as shown in FIG. 5, when the friction stir welding is performed on the workpiece W1 belonging to the thick wall group, the rotating body 42 is excessively buried in the workpiece W1, so that a part of the meat at the contact portion is As a result, the burr 48 is formed in the vicinity of the buried portion of the rotating body 42.

  Therefore, in the present embodiment, in order to avoid the occurrence of the above situation, when the workpiece W1 belonging to the thin wall group is friction stir welded and when the workpiece W1 belonging to the thick wall group is friction stir welded, Thus, a separate friction stir welding tool is used.

  That is, as shown in FIG. 6, the friction stir welding tool 40a for friction stir welding the workpieces W1 belonging to the thin-walled group includes a columnar rotating body 42a fixed to the spindle of a friction stir welding apparatus (not shown) and this rotation. A probe 44a is provided at the tip of the body 42a and buried in the contact portion between the first convex portion 10a and the second convex portion 10b of the workpiece W1.

  The length of the probe 44a is set with reference to 2.95 mm which is an intermediate value of the thickness width of the thin group. That is, as the friction stir welding tool 40a, when the friction stir welding is performed after the probe 44a is buried from one end surface to the workpiece W1 having a thickness of 2.95 mm, the gap G is appropriately maintained. A probe having a length of the probe 44a so that the raised portion 46 does not occur is selected.

  In this case, even if the thickness of the workpiece W1 is other than 2.95 mm, the thickness difference compared to 2.95 mm which is an intermediate value of the thickness width is within 0.05 mm. If the thickness difference is this level, the friction stir welding tool 40a having the probe 44a capable of performing the friction stir welding without causing the raised portion 46 to the workpiece W1 having the thickness of 2.95 mm is used. Even in this case, the rotating body 42a and the workpiece W1 are not separated from each other. Therefore, it is possible to reliably avoid the formation of the raised portion 46 after performing the friction stir welding.

  On the other hand, when the workpiece W1 belonging to the thick-walled group is friction stir welded, as shown in FIG. 7, the intermediate value of the thickness width of the thick-walled group is set to 3.05 mm, and a length that meets this standard. The friction stir welding tool 40b having the probe 44b is selected. That is, the length of the probe 44b is such that when the friction stir welding is performed after the probe 44b is buried from one end side with respect to the workpiece W1 having a wall thickness of 3.05 mm, the gap G is appropriately maintained. , The dimension is set so that the burr 48 does not occur.

  Even in this case, the difference in thickness between the actual thickness of the workpiece W1 and 3.05 mm, which is an intermediate value of the thickness width of the thick group, is within 0.05 mm. If the thickness difference is this level, the friction stir welding tool 40b having the probe 44b capable of performing friction stir welding without causing the burr 48 on the workpiece W1 having a thickness of 3.05 mm was used. Even in this case, the rotating body 42a is not excessively buried in the work W1. Accordingly, it is possible to reliably avoid the formation of the burr 48 after the friction stir welding is performed.

  As described above, when the workpiece W1 is divided into the thin-wall group and the thick-wall group, and the friction stir welding is performed on the workpiece W1 belonging to the thin-wall group, the intermediate value of the thickness width of the thin-wall group is 2.95 mm. On the other hand, when performing friction stir welding on the workpiece W1 belonging to the thick wall group, the intermediate value of 3.05 mm which is an intermediate value of the thickness width of the thick wall group was met as a standard. By selecting and separating and using the friction stir welding tools 40a and 40b having the length probes 44a and 44b, the end faces of the workpiece W1 can be reliably bonded.

  The probes 44a and 44b are brought into contact with the first protrusions 28 directly above the contact portions of the first protrusions 10a and the second protrusions 10b. In this state, when the rotating bodies 42a and 42b and the probes 44a and 44b are rotated together as the spindle is urged to rotate, the corresponding contact occurs as the probe 44 slides on the contact portion. Friction heat is generated at and near the location, and the material in that region is softened. By this softening, the tip of the probe 44 is buried in the contact portion.

  Thereafter, when the probes 44a and 44b are displaced in the direction of the arrow A in FIG. 1, that is, from the first projecting portion 28 side to the second projecting portion 30 side along the contact portion, the softened meat becomes the probe 44a, It plastically flows as it is stirred at 44b. On the other hand, when the probes 44a and 44b are separated from each other and plastic flow does not occur, the meat is hardened at this portion. By sequentially repeating such a phenomenon, the end surfaces with which the workpiece W1 abuts are integrally solid-phase bonded to form a cylindrical body W2 (see FIG. 2).

  Thereafter, the cylindrical body W2 is inspected for the presence or absence of a bonding defect in the bonding portion by an ultrasonic flaw detection inspection apparatus or the like, and the cylindrical body W2 determined to have no bonding defect is transported to a station where the drop portion molding is performed. Is done.

  In the drop portion forming step, as shown in FIG. 8, the drop portion DP is formed on the outer peripheral wall of the cylindrical body W2 by performing a spinning process using a mold 50 that can be rotated and a forming disk 52. To do. In FIG. 8, the right side is a state before processing, and the left side is a state after processing.

  The mold 50 includes divided molds 54 and 56 that are slidable with respect to each other. The split mold 54 includes a placement portion 58 a, a tapered portion 60 a that is connected to the placement portion 58 a, and a convex portion 62 that fits into the split mold 56. The split mold 56 includes a mounting portion 58 b, a tapered portion 60 b provided continuously with the mounting portion 58 b, a stepped portion 64 that is recessed from the mounting portion 58 b, and a convex portion 62 of the split mold 54. And a recess 66 to be fitted. One molding disk 52 has a protruding portion 68 corresponding to the shape of the stepped portion 64 and the tapered portions 60a and 60b.

  The cylindrical body W2 is fitted to the mounting portion 58a of the split mold 54 on the first protruding portion 28 side, and is fitted to the mounting portion 58b of the split mold 56 on the second protruding portion 30 side. In this state, the mold 50 and the molding disk 52 are rotated in opposite directions with the cylindrical body W2 interposed therebetween.

  Then, the split mold 54 is moved closer to the split mold 56, the molding disk 52 is moved closer to the cylindrical body W 2, and the cylindrical body W 2 is pressed from the outer peripheral wall side by the protrusion 68. The protruding portion 68 is finally fitted to the stepped portion 64 and the tapered portions 60a and 60b of the mold 50 through the cylindrical body W2. Thereby, the outer peripheral wall of the cylindrical body W2 is recessed toward the inner peripheral wall side, and a drop portion DP having a shape corresponding to the shape of the stepped portion 64 and the tapered portions 60a and 60b is formed.

  In the spinning apparatus configured as described above, when the displacement amount of the forming disk 52 is unchanged with the nominal thickness of 3.0 mm as a reference value, it is dropped on the cylindrical body W2 (work W1) belonging to the thin wall group. When the portion DP is provided, the protruding portion 68 of the molding disk 52 does not sufficiently contact the cylindrical body W2. That is, a so-called hit area is reduced. In this case, the cylindrical body W2 is not sufficiently processed and hardened, and for this reason, the elastic recovery scale (spring back) of the cylindrical body W2 when the molding disk 52 is separated increases. Eventually, the radius of the drop portion DP increases.

  On the other hand, when the drop part DP is provided for the cylindrical body W2 belonging to the thick wall group, the contact area of the protrusion 68 of the molding disk 52 with respect to the cylindrical body W2 becomes excessively large. For this reason, the cylindrical body W2 is excessively work-hardened. As a result, the spring back of the cylindrical body W2 when the forming disk 52 is separated is reduced, and the radius of the drop portion DP is reduced.

  Thus, the dimensional accuracy of the drop portion DP varies due to the difference in thickness of the cylindrical body W2. Therefore, in the present embodiment, when the drop portion DP is provided for the cylindrical body W2 (work W1) belonging to the thin wall group, the reference value is 2.95 mm, which is an intermediate value of the thickness width of the thin wall group. And so on. That is, the forming disk 52 is displaced to a position where the cylindrical body W2 having a wall thickness of 2.95 mm has a contact area where predetermined work hardening occurs.

  In this case, even if the thickness of the cylindrical body W2 is other than 2.95 mm, the thickness difference compared to 2.95 mm which is an intermediate value of the thickness width is within 0.05 mm. If the wall thickness difference is this level, the protrusion 68 of the molding disk 52 slides on the cylindrical body W2 belonging to the thin wall group with an appropriate contact area even when spinning processing is performed on the basis of 2.95 mm. Touch.

  On the other hand, when the drop portion DP is provided for the cylindrical body W2 belonging to the thick wall group, the molding disk 52 has a thickness of 3.05 mm, which is an intermediate value of the thickness width of the thick wall group, as a reference value. The cylindrical body W2 having a diameter of 3.05 mm is displaced to a position where the contact area is such that predetermined work hardening occurs. Of course, the work hardening in this case is equivalent to the work hardening generated in the cylindrical body W2 having a thickness of 2.95 mm.

  Even in this case, the thickness difference between the actual thickness of the cylindrical body W2 and 3.05 mm which is an intermediate value of the thickness width of the thick group is within 0.05 mm. If the wall thickness difference is this level, the protrusion 68 of the molding disk 52 slides on the cylindrical body W2 belonging to the thick wall group with an appropriate contact area even when spinning is performed with 3.05 mm as a reference. Touch.

  As can be understood from the above, according to the present embodiment, even if the cylindrical body W2 belongs to either the thick wall group or the thin wall group, the same processing is performed in the drop portion forming step (spinning processing step). The contact area of the protrusions 68, in other words, the amount of displacement of the molding disk 52 is controlled so that curing occurs.

  Thus, when the cylindrical body W2 (work W1) is divided into the thin-wall group and the thick-wall group and the cylindrical body W2 belonging to the thin-wall group is curved, it is an intermediate value of the thickness width of the thin-wall group. On the other hand, when the cylindrical body W2 belonging to the thick wall group is curved, the cylinder 52 is displaced by displacing the molding disk 52 with respect to 3.05 mm which is an intermediate value of the thickness width of the thick wall group. A drop portion DP having a predetermined radius can be provided with high dimensional accuracy with respect to the body W2.

  The cylindrical body W2 provided with the drop portion DP is further provided with a curled portion at its end face, and then a hump portion is formed between the curled portion and the drop portion DP. Thereafter, a valve hole and a drain hole are formed at predetermined positions, and a wheel rim is obtained.

In the embodiments described above, it has been described as an example the case of manufacturing the e Irurimu, but the invention is not limited thereto, rather it can be employed in the case of producing the other member Not too long.

It is a schematic whole perspective view of the plate-shaped workpiece | work used as a wheel rim. It is a schematic whole perspective view of the cylindrical body formed by joining a contact location after the workpiece | work of FIG. 1 is curved. It is a principal part enlarged front view which shows arrangement | positioning of the three forming rolls which comprise the roll forming apparatus for curving the workpiece | work of FIG. It is a principal part expanded longitudinal cross-sectional view which shows the state which the probe of the tool for friction stir welding was buried in the contact location of the workpiece | work which belongs to a thin wall group. It is a principal part expanded longitudinal cross-sectional view which shows the state which the probe of the tool for friction stir welding was buried in the contact | abutting location of the workpiece | work which belongs to a thick group. It is a principal part expansion longitudinal cross-sectional view which shows the state by which the probe of the friction stir welding tool was buried in the contact location with respect to the workpiece | work which belongs to a thin wall group. It is a principal part expanded longitudinal cross-sectional view which shows the state by which the probe of the friction stir welding tool was embed | buried in the contact location with respect to the workpiece | work which belongs to a thick wall group. It is operation | movement description longitudinal cross-sectional view of the spinning processing apparatus for providing a drop part in a cylindrical body.

10a to 10d ... convex portions 20, 22, 24 ... forming rolls 28, 30 ... projecting portions 40, 40a, 40b ... friction stir welding tools 44, 44a, 44b ... probes 46 ... raised portions 48 ... burrs 50, 54, 56 ... Mold 52 ... Molding disk 68 ... Protrusion CL ... Clear DP ... Drop part G ... Gap W1 ... Work W2 ... Cylinder

Claims (2)

When performing friction stir welding on a plurality of workpieces individually, a friction stir welding tool having a probe with a dimension corresponding to the thickness of each workpiece that differs within a tolerance range from a reference value is selected, and the friction stir welding is selected. A friction stir welding method for performing friction stir welding with a stir welding tool,
A plurality of the workpieces, a thick group whose thickness is from the reference value to the maximum allowable value within the tolerance range, and a thin wall group whose thickness is from the reference value to the minimum allowable value within the tolerance range And separated
A first median value that is an intermediate value between the reference value and the maximum allowable value, and a second median value that is an intermediate value between the reference value and the minimum allowable value;
While the first friction stir welding tool having a probe having a dimension corresponding to the thickness of the first median value is selected as the friction stir welding tool for the thick wall group, the first median thickness according to the thickness of the second median value A second friction stir welding tool having a probe of a different size is selected as the friction stir welding tool for the thin-walled group ,
Friction against the thick group performs friction stir welding at said first friction stir welding tool, wherein for thin groups and performing friction stir welding at said second friction stir welding tool Stir welding method. In the friction stir welding method according to claim 1, when the workpiece is a plate material, and the plate material is subjected to friction stir welding with respect to end surfaces that are curved and faced to each other,
Prior to the friction stir welding, when a plurality of plate members are individually curved with a displaceable roller, when the thick group is curved, the displacement amount of the roller is set to the first displacement amount. While the first displacement amount is set according to the median thickness, when the bending process is performed on the thin wall group, the displacement amount of the roller is set to the second displacement value according to the second median thickness. Set as displacement amount,
While performing the bending process with the first displacement amount for the thick-walled group, performing the bending process with the second displacement amount for the thin-walled group to bring the end surfaces of the plate members into contact with each other,
Thereafter, friction stir joining method and performing the friction stir welding to the end faces abutting against.

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