Abstract: A friction stir welding spindle includes a support having a center bore. A spindle shaft is adapted to support a stir welding tool and extends within the bore. A bearing assembly allows simultaneous rotational and axial displacement of spindle shaft in the bore relative to the support. A sensing device is adapted to provide an output signal indicative of at least one of a force coincident with axial displacement of the spindle shaft and an axial position of the spindle shaft.

Abstract: Method of joining together two planar members, by a friction stir welding operation wherein a rotary tool having a probe is moved relative to a joint region defined between the mutually butted planar members such that the probe is rotated and inserted in the joint region. The welding operation is performed by using a tab plate having a cutout formed in its end face such that the cutout has a width not smaller than a radius of a peripheral circle to be described by the shoulder surface, and a depth not smaller than a minimum radius of the probe and not larger than the radius of the peripheral circle.

Abstract: The invention provides a friction stir welding apparatus and method and a processing apparatus and method, which are not easily affected by deformations of a work being processed. The friction stir welding apparatus inserts a rotating tool into the work and moves the rotating tool relative to the work to join members of the work. The friction stir welding apparatus and method and the processing apparatus and method of the invention, the latter cutting or grinding the work with a rotating cutter or grindstone, comprises controlling a relative distance between the tool, cutter or grindstone and the work under the joining or processing operation or an insertion depth so that the load factor or electric current of a spindle motor for rotating the tool, cutter or grindstone is within a predetermined range, and a controller therefor.

Abstract: A first metal member is contacted with a second metal member. A metal fastener is provided including a core and a cladding disposed upon the core. The fastener is driven through the first member and into the second member, inducing friction between the fastener, the first member and the second member for at least locally melting portions of the cladding, the first member and the second member to form a flowable material that solidifies and metallurgically bonds the fastener to the first member and the second member for attaching the members together.

Abstract: The invention provides a discontinuous friction stir welding apparatus and welding method having a compact machine head capable of corresponding to a wide usage. In a friction stir welding apparatus provided with a tool (1) having a shoulder portion (1a) with a large diameter and a pin portion (1b) with a small diameter protruding in an axial direction, and welding by inserting the tool to a material to be welded while rotating the tool, the tool, a moving mechanism of the tool and a backing member (5) for the welded material are received in one frame (10). The tool moving mechanism has a main axis motor (2) for rotating the tool, an axial moving apparatus (4, 13a, 13b, 14) for moving the tool in a direction of a rotation axis, and a welding direction moving apparatus (9, 17) for moving the tool along a weld line of the welded material.

Abstract: A stir friction pin tool has at least a portion of its distal end or tip which is either more rough than the cylindrical portion of the pin tool, or which has a surface roughness greater than 128 &mgr;″ regardless of the roughness of the cylindrical portion. The pin tool may include machined holes or slots, or may have an etched tip surface. The roughness aids in generating heat during the plunging portion of a stir friction welding or heating operation, to thereby reduce the overall time required for the operation.

Abstract: The apparatus for operating on a workpiece includes a die defining first and second apertures and an interior therebetween. The first aperture and the interior of the die are structured to receive the workpiece. The interior of the die can be structured to shape the workpiece into a predetermined configuration. The apparatus includes at least one rotatable pin extending at least partially into the interior of the die. The pin is structured to at least partially stir the workpiece as the workpiece moves through the interior of the die to thereby refine the grain structure of the workpiece.

Abstract: A friction stir welding method conducts contact welding on two welding target members having different high temperature deformation resistances by using a welding tool having a rotatable welding head, contacting the two welding target members having different high temperature deformation resistances against each other so as to generate a difference in height between the two welding target members on a surface side in a thickness direction, arranging the rotating head in a state in which the head is embedded into a contact section of the two welding target members or a neighborhood of the contact section from the surface side, and relatively moving the welding head to the two welding target members along the contact section in this state, is provided.

Abstract: Two beams 17 and 18 perpendicular to a moving trajectory Q are formed in an intake port opening 14 of a cylinder head material to serve as margins for interfering with deformation of the opening 14 due to softening of the material, thereby a deformation of the material and a void caused by the deformation can be prevented in the frictional stirring with the rotary tool.

Abstract: In a frictional stirring weld apparatus for bonding elements with a rotary tool, a head is movable with respect to the elements to position and orient the rotary tool so that a pin of the rotary tool is aligned along a boundary between first surfaces and a shoulder of the rotary tool faces to second surfaces extending radially outward from the first surfaces, and to generate a relative movement between the rotary tool and the elements along the second surfaces, and a compensating member is capable of holding thereon the rotary tool, at least partially rotatable on the rotational axis with respect to the head to rotate the rotary tool, and supported on the head movably along the rotational axis with respect to the head so that a positional relationship between the rotary tool and a combination of the elements is adjustable in a direction parallel to the rotational axis.

Abstract: On a main shaft 30 of a numeric control type machine tool, a rotary tool 50 is installed. The main shaft 30 is not inclined in the machine tool. A first member 70 and a second member 76 to be subjected to friction stir welding are fixed on a table 20. Relative to an axial center of the rotary tool 50, a non-linear welding portion of the first member 70 and the second member 76 is inclined by inclining the table 20. Then, by rotating the table 20 and relatively moving the portion to be welded into contact with the rotary tool 50, welding of the first member to the second member is carried out according to friction stir welding. The above-stated inclination is the inclination required for the friction stir welding. In this way, welding along a path of ring shape or circular shape (including a circular arc) using friction stir welding can be carried out easily.

Abstract: In a method and apparatus for joining at least two adjoining workpieces by friction welding, a rotatable shaft is provided at its front end with a friction welding tool which is biased toward the workpieces to plasticize an area of the workpiece into which the tool enters while the plasticized material is displaced and stored in, or around, the tool. Upon passing through the top workpiece and entering the lowermost work piece, the tool is removed and the stored plasticized material is returned to the void provided by the tool upon removal thereof from the workpieces for joining the workpieces.

Abstract: In a railway car, extruded frame members of an aluminum base alloy containing Si of 0.4-0.9 wt % and Mg of 0.4-1.2 wt % are welded according to a friction stir welding method. In a structure, an aluminum base alloy plate containing Si of 0.4-0.9 wt % and Mg of 0.4-1.2 wt % is prepared, to one face of the aluminum base alloy plate a rib is formed, and the aluminum base alloy plate is an extruded frame member. Accordingly, a railway car having a low welding distortion and a structure having a low welding distortion can be obtained.

Abstract: This invention provides a configuration of a joint that allows a satisfactory welded joint to be formed with reduced deformation of the joint region when two-face structures (panels) are friction-welded end to end. The panels 31, 32. each have two substantially parallel plates 33, 34 and a third member 35 connecting the two plates 33, 34. The end portions of the plates 33, 34 of one panel 32 are friction-welded to the end portions of the plates 33, 34 of the other panel 32. At least one of the panels has a plate 36 at its end for connecting the plates 33 and 34 and has a rigidity to support a pressing force produced during the friction welding.

Abstract: This invention provides a configuration of a joint that allows a satisfactory welded joint to be formed with reduced deformation of the joint region when two-face structures (panels) are friction-welded end to end. The panels 31, 32 each have two substantially parallel plates 33, 34 and a third member 35 connecting the two plates 33, 34. The end portions of the plates 33, 34 of one panel 32 are friction-welded to the end portions of the plates 33, 34 of the other panel 32. At least one of the panels has a plate 36 at its end for connecting the plates 33 and 34 and has a rigidity to support a pressing force produced during the friction welding.

Abstract: This invention provides a configuration of a joint that allows a satisfactory welded joint to be formed with reduced deformation of the joint region when two-face structures (panels) are friction-welded end to end. The panels 31, 32 each have two substantially parallel plates 33, 34 and a third member 35 connecting the two plates 33, 34. The end portions of the plates 33, 34 of one panel 32 are friction-welded to the end portions of the plates 33, 34 of the other panel 32. At least one of the panels has a plate 36 at its end for connecting the plates 33 and 34 and has a rigidity to support a pressing force produced during the friction welding.

Abstract: A rotary tool (140) is relatively moved against members (30, 30) to be welded so as to perform friction stir welding of said members, while blades (145) mounted on the rotary tool (140) and a rotary brush (220) are used to cut the welded portion, and swarfs on the cut surface are removed through a suction opening (225), before medium liquid is supplied on said cut surface through a supply opening (240). Next, an inspection roller (250) is rotated on the surface of the welded portion for inspection. A probe (251) is provided within the roller (250). Upon detecting a defect, paint is applied to the position of defect by a marking device (270). Thereafter, based on said marking, the joint portion is cut and repaired by welding.

Abstract: This invention provides a configuration of a joint that allows a satisfactory welded joint to be formed with reduced deformation of the joint region when two-face structures (panels) are friction-welded end to end. The panels 31, 32 each have two substantially parallel plates 33, 34 and a third member 35 connecting the two plates 33, 34. The end portions of the plates 33, 34 of one panel 32 are friction-welded to the end portions of the plates 33, 34 of the other panel 32. At least one of the panels has a plate 36 at its end for connecting the plates 33 and 34 and has a rigidity to support a pressing force produced during the friction welding.

Abstract: This invention provides a configuration of a joint that allows a satisfactory welded joint to be formed with reduced deformation of the joint region when two-face structures (panels) are friction-welded end to end. The panels 31, 32 each have two substantially parallel plates 33, 34 and a third member 35 connecting the two plates 33, 34. The end portions of the plates 33, 34 of one panel 32 are friction-welded to the end portions of the plates 33, 34 of the other panel 32. At least one of the panels has a plate 36 at its end for connecting the plates 33 and 34 and has a rigidity to support a pressing force produced during the friction welding.

Abstract: A method of stir welding T-joints comprises assembling and stir welding first and second members. The first member comprises a sheet portion of material and also comprises restraining surfaces. The second member comprises a rib. The rib is stir welded to the sheet portion with the edge margin of the rib being positioned between the restraining surfaces of the first member. During stir welding, the restraining surfaces of the first member limit movement of the rib relative to the first member. A tooling portion is preferably formed as a contiguous portion of the material of one of the first and second members. The first and second members are secured to a stir welding apparatus via the tooling portion during the stir welding. The method yet further comprises a step of separating the tooling portion from the first and second members after forming the stir welded T-joint.

Abstract: This invention provides a configuration of a joint that allows a satisfactory welded joint to be formed with reduced deformation of the joint region when two-face structures (panels) are friction-welded end to end. The panels 31, 32 each have two substantially parallel plates 33, 34 and a third member 35 connecting the two plates 33, 34. The end portions of the plates 33, 34 of one panel 32 are friction-welded to the end portions of the plates 33, 34 of the other panel 32. At least one of the panels has a plate 36 at its end for connecting the plates 33 and 34 and has a rigidity to support a pressing force produced during the friction welding.

Abstract: This invention provides a configuration of a joint that allows a satisfactory welded joint to be formed with reduced deformation of the joint region when two-face structures (panels) are friction-welded end to end. The panels 31, 32 each have two substantially parallel plates 33, 34 and a third member 35 connecting the two plates 33, 34. The end portions of the plates 33, 34 of one panel 32 are friction-welded to the end portions of the plates 33, 34 of the other panel 32. At least one of the panels has a plate 36 at its end for connecting the plates 33 and 34 and has a rigidity to support a pressing force produced during the friction welding.

Abstract: Disclosed is a friction stir welding technique which avoids occurrence of a dent, in adjoining region, extending to a level beneath the joined surfaces. At end portions of the frame members to be joined, at the joining region, thickened parts which project toward the rotary body joining tool are provided. Two adjoining thickened parts, of adjacent members to be joined, can form a trapezoid shape. The rotary body joining tool has a small-diameter tip portion and a larger diameter portion. The rotary body joining tool is inserted in the thickened parts. In a state where the rotary body joining tool has been inserted small-diameter tip and first, to a level where the larger diameter portion of the rotary body joining tool overlaps the thickened part but does not extend below the upper surface of the non-thickened surfaces of the members joined, the rotary body is rotated and moved along the joining region. Even when a gap exists between two thickened parts, a desirable joining can be carried out.

Abstract: It is an object of the present invention to provide a friction stir welding method and apparatus capable of maintaining a rotating tool and workpieces at a substantially constant geometrical relation for arbitrary curved surfaces having a three-dimensional shape, as well as a welded structure obtained thereby.

Abstract: Disclosed is a friction stir welding method of welding a butted portion of work pieces relatively easily and firmly with an improved finish after the butted portion is tack-welded. In the method, a plurality of work pieces are placed to be butted, a plurality of V-shaped grooves are intermittently formed along the butted portion, each of the grooves is tack-welded by using a welding material by TIG welding or MIG welding, deposits in the tack-welded sections are cut and removed so as to be substantially coplanar with a surface of the work pieces, and then friction stir welding is continuously performed over the entire length of the butted portion, and thus, the work pieces are joined.

Abstract: A turbine blade closure system composed of a closure member capable of being friction welded in an aperture in a hollow-cast turbine blade to prevent the escape of cooling fluids from an internal cavity in the turbine blade. In one embodiment, the aperture is formed in the turbine blade during the manufacturing process as a result of one or more support projections used to position a core block in a turbine blade mold.

Abstract: An internal channel in a metal body for use in applications where internal fluid flow within a metal body is desired, as in a heat exchanger. The internal channel is formed in the metal body by frictionally stirring with a pin plunged into the metal body, and traversing the metal body with the pin.

Abstract: A shaped metallic component is formed by friction stirring at least a segment of a single piece of bulk metal to impart superplasticity thereto and thereby yield a single superplastic metal blank from the single piece of bulk metal. The metal blank is then deformed by a metal deformation process such as forging, rolling, drawing, bending, extruding, gas forming, punching, and stamping.

Abstract: The present invention provides an improved structural assembly constructed of a plurality of structural members secured together. At least one of the plurality of structural members defines a first region characterized by comparatively high operational stress and a second region having a locally refined grain structure positioned such that the second region at least partially encompasses the first region to thereby enhance the strength, toughness and fatigue resistance of the at least one structural member in the first region. The present invention also provides a method for selectively improving the strength, toughness and fatigue resistance of a structural member in a region of high operational stress including the steps of casting the structural member in a pre-selected configuration. Regions of the structural member having comparatively high operational stress are identified. The structural member is secured to prevent movement.

Abstract: A machining device comprising five axial kinetic coordinate systems that can be controlled simultaneously, three axes of which are linear moving axes and two axes of which are rotary axes, with one axis of the five axes being provided with a tool rotating function, whereby said machining device is equipped with a cutting tool 51 and a friction stir welding tool 52. The current value observed when a large-diameter portion of said tool 52 contacts the work object is set in advance, and by observing the torque current of the rotary shaft of the tool 52 during friction stir welding, the insertion depth of the tool 52 can be controlled by maintaining the observed torque current above the preset current value, thus providing a good weld. A single device can provide both the cutting and the welding. Thus, it is possible to reduce equipment cost, installation space, plant area, lead time and production cost.

Abstract: A friction stir welding tool includes a friction stir welding head having a probe and spindle rotatably mounted at a first end. A support supports the stir welding head between the first end and a second end for movement about a pitch axis. A pitch actuator includes an elongated arm coupled to the stir welding head at a point longitudinally spaced from pitch axis to overcome the relatively large forces exerted at the probe. A turntable supports the stir welding head for movement about a yaw axis. A yaw actuator includes an elongated arm coupled to the turntable laterally spaced from the yaw axis, to overcome the relatively large forces exerted at the probe. A controller maintains an angle of attack of the probe with respect to direction of travel of the probe along the work piece.

Abstract: A machining device comprising five axial kinetic coordinate systems that can be controlled simultaneously, three axes of which are linear moving axes and two axes of which are rotary axes, with one axis of the five axes being provided with a tool rotating function, whereby said machining device is equipped with a cutting tool 51 and a friction stir welding tool 52. The current value observed when a large-diameter portion of said tool 52 contacts the work object is set in advance, and by observing the torque current of the rotary shaft of the tool 52 during friction stir welding, the insertion depth of the tool 52 can be controlled by maintaining the observed torque current above the preset current value, thus providing a good weld. A single device can provide both the cutting and the welding. Thus, it is possible to reduce equipment cost, installation space, plant area, lead time and production cost.

Abstract: There are provided an apparatus and method for friction welding structural members. The apparatus includes a connected shank and probe. The probe defines an absorption surface and a cavity extending thereto. The absorption surface is configured to receive electromagnetic radiation from an electromagnetic radiation source such as a light source or RF generator. The radiation heats the probe, supplementing the heat generated by friction between the probe and the structural members, and thereby increasing the speed at which the probe can be used to frictionally weld the structural materials.

Abstract: The present invention provides an improved method and apparatus for joining aluminum allow panels (eg. 2090-T83 aluminum lithium alloy). The method preliminarily positions two panels and skin panels next to each other so that a stringer panel overlaps a skin panel. A friction stir weld pin tool penetrates through one panel and at least partially into another panel. The panel material around the pin tool is frictionally heated, plasticized and joined until the faying surface is substantially consumed. In another embodiment, a tee-shaped structure is formed using friction stir welding to join three panels together.

Abstract: There is provided a mandrel for spin forming that has a backing plate with removably attached mandrel portions and mandrel spacers, such that the mandrel is adaptable to numerous configurations. The various configurations of the mandrel are used to provide different spin forming contour surfaces upon which metal sheets or other spin formable materials can be spin formed. The adaptable mandrel also provides the ability to create a desired spin formed product from either a single metal sheet or multiple metal sheets joined by friction stir welding or other suitable processes. A spin formed welded metal sheet may also undergo a trimming process to remove the portions of the welded metal sheet having sufficiently different material properties resulting from the weld process, including the weld joint.

Abstract: When pressurizing and relatively moving the objects to be bonded to each other relative to each other subject their metallic bonding portions to friction bonding for the friction bonding of the metallic bonding portions, the friction bonding operation is temporarily partway reduced or stopped.

Abstract: A cutting tool 60 cuts along the butted portion between two members 10, 20. A filling material 30 is inserted to the gap 40 formed by said cutting, and a roller 70 presses protrusions 12 and 22 to crimp said protrusions 12 and 22 so as to fix said filling material to position. Next, friction stir welding is performed to the protrusions 12, 22 and the filling material 30 using a rotary tool 80. In another example, instead of cutting, the filling material can be welded and filled to the gap. In yet another example, cutting can be performed so as to approximate the two members before performing the friction stir welding step.

Abstract: An apparatus and method for forming a friction stir weld joint in a workpiece are provided. The apparatus includes a friction stir welding tool having a shoulder and a rotatable pin extending therefrom. The rotational speed of the pin can be adjusted during a friction stir welding operation, e.g., cyclically and/or according to a predetermined schedule, so that the pin mixes the plasticized material of the workpiece. The workpiece can also be preheated before friction stir welding.

Abstract: In one aspect the invention provides a friction welded component, and a method of manufacture for such a component, comprising a pair of upstanding tubular members (6,8) which are friction welded at their respective end cross-sections, in coaxial concentric relationship, to a surface of a thin walled member (4). A reinforcement means (10) is provided in the region between the tubular members such that loads acting on the tubular members are more evenly distributed to the thin walled member. The wall thickness of the thin walled member is substantially the same as or greater than the wall thickness of the tubular members The invention finds particular application in the fabrication of bosses to gas turbine aero-engine casings.

Abstract: A joint between one or more structural members and an associated method are provided. The joint includes a friction weld joint or other connection between faying surfaces of the members, and an exothermically reacted sealant disposed in an interface defined by the faying surfaces. The exothermic reaction of the sealant in the interface can be initiated before, during, or after joining the structural members such that the sealant at least partially seals the interface. The sealant can fill the spaces between the structural members to prevent the entry of chemicals, moisture, debris, and other substances, thereby reducing the likelihood of corrosion of the joint or structural members at the interface. Further, the sealant can form a bond with the structural members, thereby increasing the strength of the connection between the members.

Abstract: We have discovered a method of producing a complex-shaped aluminum alloy article, where welding has been employed to form the article, where an anodized aluminum coating is produced over a surface of the article including the weld joint, and where the anodized aluminum coating is uniform, providing improved performance over that previously known in the art for welded articles exposed to a corrosive plasma environment.

Abstract: Method of manufacturing a tubular end product, wherein an aluminum plate is formed into a generally cylindrical body such that opposite end sections of the cylindrical body are flattened and butted together along a joint region extending parallel to an axis of the cylindrical body, and such that each of the opposite flattened end sections has a predetermined width L as measured normal to the joint region, and the opposite flattened end sections are joined together at the joint region, by a friction stir butt welding operation wherein a rotary tool having a circular shoulder surface and a probe extending from the shoulder surface is moved relative to the cylindrical body while the shoulder surface is in rubbing contact with the flattened end sections, with the probe being rotated with the rotary tool and inserted in the joint region.

Abstract: A tool for forming a friction stir weld joint in a workpiece is provided. According to one embodiment, the tool includes a rotatable pin having first and second ends and defining a stirring portion therebetween structured to frictionally engage the workpiece so as to at least partially form the friction stir weld joint. In particular, the stirring portion of the pin defines at least one groove and ridge, each of which extend generally circumferentially around an axis of the pin. The tool can also include a second shoulder opposing the first shoulder such that the pin extends therebetween.

Abstract: End portions of face plates 111 and 112 of a frame member 110 are connected by a rib 116A. To protrusion chips 117b1 and 117b2 end portions of face plates 101 and 102 of another frame member 100 are overlapped. The corners between the rib 116A and the rear faces of the face plates 111 and 112 are in the form of a convex circular arc 131 which protrudes into a hollow portion 119 of the frame member 110. Both end portions of the circular arc 131b1 are connected to the rib 116A and the face plates 111 and 112 by two smooth recessed circular arcs 132b1 and 133b1. Accordingly, since a flow-out of metal does not occur from this portion, the cross-section can be small and a light weight structure an be obtained. A structural body formed of hollow frame members which are joined by friction stir welding provides a light weight structure.

Abstract: This invention provides a configuration of a joint that allows a satisfactory welded joint to be formed with reduced deformation of the joint region when two-face structures (panels) are friction-welded end to end. The panels 31, 32 each have two substantially parallel plates 33, 34 and a third member 35 connecting the two plates 33, 34. The end portions of the plates 33, 34 of one panel 32 are friction-welded to the end portions of the plates 33, 34 of the other panel 32. At least one of the panels has a plate 36 at its end for connecting the plates 33 and 34 and has a rigidity to support a pressing force produced during the friction welding.

Abstract: This invention provides a configuration of a joint that allows a satisfactory welded joint to be formed with reduced deformation of the joint region when two-face structures (panels) are friction-welded end to end. The panels 31, 32 each have two substantially parallel plates 33, 34 and a third member 35 connecting the two plates 33, 34. The end portions of the plates 33, 34 of one panel 32 are friction-welded to the end portions of the plates 33, 34 of the other panel 32. At least one of the panels has a plate 36 at its end for connecting the plates 33 and 34 and has a rigidity to support a pressing force produced during the friction welding.

Abstract: This invention provides a configuration of a joint that allows a satisfactory welded joint to be formed with reduced deformation of the joint region when two-face structures (panels) are friction-welded end to end. The panels 31, 32 each have two substantially parallel plates 33, 34 and a third member 35 connecting the two plates 33, 34. The end portions of the plates 33, 34 of one panel 32 are friction-welded to the end portions of the plates 33, 34 of the other panel 32. At least one of the panels has a plate 36 at its end for connecting the plates 33 and 34 and has a rigidity to support a pressing force produced during the friction welding.

Abstract: An apparatus for friction welding a workpiece to a substrate, comprising an actuator producing a linear oscillating motion, a platform for supporting the workpiece, and a slide mechanism between the actuator and the platform. The slide mechanism converts the linear oscillating motion of the actuator into an arcuate oscillating motion of the platform. The slide could comprise a base and a guide engaging the platform.

Abstract: A laser-assisted friction stir welding method for joining workpieces, that includes the step of providing a side face for each workpiece between first and second workpiece surfaces, each side face shaped such that, in a pressed-together condition, the side faces touch each other at the second workpiece surface and are spaced from each other in a middle region of the side faces so that a gap exists between the side faces at the first workpiece surface. The method also includes pressing together the side faces so as to form a joint area, and advancing a welding probe, while the probe is in rotary motion, along the joint area at the first workpiece surface and irradiating workpiece material located in front of the welding probe using laser radiation so as to plasticize the workpiece material along the joint area. The method also includes removing the welding probe from the joint area before the workpiece material completely solidifies.

Abstract: This invention provides a configuration of a joint that allows a satisfactory welded joint to be formed with reduced deformation of the joint region when two-face structures (panels) are friction-welded end to end. The panels 31, 32 each have two substantially parallel plates 33, 34 and a third member 35 connecting the two plates 33, 34. The end portions of the plates 33, 34 of one panel 32 are friction-welded to the end portions of the plates 33, 34 of the other panel 32. At least one of the panels has a plate 36 at its end for connecting the plates 33 and 34 and has a rigidity to support a pressing force produced during the friction welding.