US20120118937A1 - Friction stir welding method and its device - Google Patents
Friction stir welding method and its device Download PDFInfo
- Publication number
- US20120118937A1 US20120118937A1 US13/280,576 US201113280576A US2012118937A1 US 20120118937 A1 US20120118937 A1 US 20120118937A1 US 201113280576 A US201113280576 A US 201113280576A US 2012118937 A1 US2012118937 A1 US 2012118937A1
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- work piece
- corner
- friction stir
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
- B23K—SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM
- B23K20/00—Non-electric welding by applying impact or other pressure, with or without the application of heat, e.g. cladding or plating
- B23K20/12—Non-electric welding by applying impact or other pressure, with or without the application of heat, e.g. cladding or plating the heat being generated by friction; Friction welding
- B23K20/122—Non-electric welding by applying impact or other pressure, with or without the application of heat, e.g. cladding or plating the heat being generated by friction; Friction welding using a non-consumable tool, e.g. friction stir welding
- B23K20/123—Controlling or monitoring the welding process
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
- B23K—SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM
- B23K20/00—Non-electric welding by applying impact or other pressure, with or without the application of heat, e.g. cladding or plating
- B23K20/12—Non-electric welding by applying impact or other pressure, with or without the application of heat, e.g. cladding or plating the heat being generated by friction; Friction welding
- B23K20/122—Non-electric welding by applying impact or other pressure, with or without the application of heat, e.g. cladding or plating the heat being generated by friction; Friction welding using a non-consumable tool, e.g. friction stir welding
- B23K20/123—Controlling or monitoring the welding process
- B23K20/1235—Controlling or monitoring the welding process with temperature control during joining
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- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
- Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
- Y10T409/00—Gear cutting, milling, or planing
- Y10T409/30—Milling
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
- Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
- Y10T409/00—Gear cutting, milling, or planing
- Y10T409/30—Milling
- Y10T409/300056—Thread or helix generating
- Y10T409/300112—Process
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
- Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
- Y10T409/00—Gear cutting, milling, or planing
- Y10T409/30—Milling
- Y10T409/300056—Thread or helix generating
- Y10T409/300168—Thread or helix generating with means to regulate operation by use of templet, card, or other replaceable information supply
- Y10T409/300336—Thread or helix generating with means to regulate operation by use of templet, card, or other replaceable information supply to regulate rate of motion [e.g., stopping, etc.]
Definitions
- the present invention relates to a friction stir welding method and its welding device in which jointing portions to be jointed of metal work piece are stirred to be flown in a plastic state due to friction heat generated by stirring and then the metal structure of the jointing portions is cooled down to be unified.
- Friction stir welding is a solid-state joining process without using fusion or filler materials, thereby the original metal characteristics being maintained to be unchanged as far as possible.
- a conventional friction stir welding method of this kind is disclosed in Japanese Patent NO. 4215179.
- This prior friction stir welding method has a tool with a small pin or nib, a drive electric motor that rotates the tool, an air cylinder that presses the tool on jointing portions of a work piece, and slide mechanisms that moves the tool on a horizontal surface (X-axial direction and Y-axial direction) and in a vertical direction (Z-axial direction).
- the tool has a shoulder portion, which is larger in radiator than the pin. The shoulder and the pin are pressed on the jointing portions, being rotated, so as to be inserted into them, and the tool is moved along the jointing portions in a state where a center axis of the tool is slanted along the moving direction so that the pin side is positioned forward.
- the tool with pin When the above-mentioned friction stir welding method is applied to a work piece which has straight sections connected with each other through a tight corner such as a square corner or a small round corner, the tool with pin is needed to change its moving direction at the corner.
- the tool with pin is rotated on the corner at a high total speed consisting of a rotating speed of the tool with pin and a direction changing speed thereof. Consequently, the heat generated on the corner rises to have a temperature higher than that generated at the straight sections of the work piece. This higher heat might cause the metal characteristics of the jointed portions to be changed due to the temperature higher than the melting point of the work piece, and/or it might deteriorate the durability of the pin.
- a first object of the present invention to provide a friction stir welding method which overcomes the foregoing drawbacks and can weld portions to be joined of a work piece as fast as possible, avoiding the temperature of the portions to be jointed of the work piece from reaching the melting point of the work piece at a tight corner such as a square corner and a small round corner during friction stir welding.
- a friction stir welding method in which a tool is moved being rotated along portions to be joined of a work piece, where the portions includes a corner with a smaller curvature that connect two portions with larger curvatures.
- the method comprising the steps of: setting the work piece on a supporting member, rotating the tool around a center axis of the tool, moving the tool toward the work piece to penetrate a portion of the tool into the work piece at the portions to be joined, and moving and turning the tool along the portions to be joined.
- a rotation speed of the tool around the center axis of the tool is decreased to be smaller at the corner with the smaller curvature than the rotation speed of the tool around the center axis of the tool at the portions with the larger curvatures.
- the method of the present invention can weld the portions to be joined of the work piece as fast as possible, avoiding the temperature of the portions to be jointed of the work piece from reaching the melting point of the work piece at the corner with smaller curvature, namely the tight corner, during friction stir welding.
- a friction stir welding device for welding portions to be jointed of a work piece having a corner with a smaller curvature that connect two portions with larger curvatures.
- the device includes a supporting member that supports the work piece, a horizontally moving mechanism capable of moving the work piece on a horizontal surface, a vertically moving mechanism capable of vertically moving tool so as to penetrate in and depart from the portions to be joined, a direction changing mechanism capable of changing an advance angle direction of the tool whose center axis is inclined relative to an upper surface of the portions to be joined, a rotating mechanism capable of rotating the tool around the center axis of the tool, and a controller capable of controlling the horizontally moving mechanism, the vertically moving mechanism, the direction changing mechanism, and the rotating mechanism in such a way that a rotation speed of the tool around the center axis of the tool is decreased to be smaller at the corner with the smaller curvature than the rotation speed of the tool around the center axis of the tool at the portions with the larger curvatures.
- the device of the present invention can weld the portions to be joined of the work piece as fast as possible, avoiding the temperature of the portions to be jointed of the work piece from reaching the melting point of the work piece at the corner with smaller curvature, namely the tight corner, during friction stir welding.
- the corner with the smaller curvature is one of a round corner and a square corner.
- the welding stir method and its device of the present invention are suitable to the work pieces having such corners.
- the tool has a tool main body having a cylindrical body shape, a pin that is provided on an end portion of the tool main body, and a shoulder surface provided on the end portion of the tool main body, and a travel direction of the tool is changed by a center axis of the tool being turned around a center point of the shoulder surface.
- welding zone can be pretended from departing the portions to be joined.
- FIG. 1 is a front view showing a friction stir welding device that performs a friction stir welding method of a first embodiment according to the present invention
- FIG. 2 is an exploded view showing a state where main parts, namely a pin and a tool shoulder, of the friction stir welding device shown in FIG. 1 are inserted into members to be jointed;
- FIG. 3 is a block diagram showing a controller that is used in the friction stir welding device shown in FIG. 1 and its control system;
- FIG. 4 is a time chart showing control contents that are carried out by the controller of the friction stir welding device shown in FIG. 1 ;
- FIG. 5 is a view showing a shape of portions to be joined of a work piece, to which the friction stir welding method of the first embodiment is applied;
- FIG. 6 is a view showing a shape of portions to be joined of a work piece, to which a friction stir welding method of a second embodiment according to the present invention is applied.
- FIG. 7 is a time chart showing control contents that are carried out in the friction stir welding method of the second embodiment.
- FIG. 1 of the drawing there is shown a friction stir welding device that can perform a friction stir welding method of a first preferred embodiment of the present invention.
- the friction stir welding deice of the first embodiment is equipped with a base 1 , a horizontally slidable table 2 , a main frame 3 , a vertically slidable frame 4 , a rotatable cylinder 5 , a spindle 7 with a tool chuck 7 a, a tool 8 , and a controller 9 .
- the base 1 is a strong metal frame having like a rectangular shape, and it is firmly placed on a floor to support the main parts of the friction stir welding device thereon.
- the horizontally slidable table 2 is placed on the base 1 to fix a work piece 10 thereon, and it includes an X-axial directional slide mechanism 21 and a Y-axial directional slide mechanism 22 so that the slide mechanisms 21 and 22 can move the work piece 10 relative to the base 1 on a horizontal surface.
- the X-axial directional slide mechanism 21 and the Y-axial directional slide mechanism 22 correspond to a horizontally moving mechanism of the present invention.
- the X-axial direction is a left and right direction in FIG. 1
- the Y-axial direction is a front and rear direction perpendicular to the X-axis in FIG. 1 .
- the X-axis directional movement of the horizontally slidable table 2 is executed by an X-axis servo motor 91 , which is provided at the outer side of the right portion of the main frame 3 and on the right portion of the base 1 to move a first carrier plate 21 a in the X-axial direction.
- the Y-axis directional movement of the horizontally slidable table 2 is executed by a Y-axis servo motor 92 , which is provided on the center front portion of the carrier plate 21 a of the X-axis directional slide mechanism 21 to move the second carrier plate 22 a in the Y-axis direction.
- a cramping table 2 a is fixed on the second carrier plate 22 a to cramp the work piece 10 thereon.
- the servo motors 91 and 92 rotate screw shafts 91 a, 92 a so that engaging portion provided under the first carrier plate 21 a and the second carrier plate 22 a so that the carrier plates 21 a and 22 a can move on the horizontal X-axial and Y-axial lines parallel to the screw shafts 91 a, 92 a, respectively.
- the X-axial directional slide mechanism 21 is arranged over the Y-axial directional slide mechanism 22 in the first embodiment, while the former may be arranged under the latter.
- the cramping table 22 a corresponds to a supporting member of the present invention.
- the main frame 3 is shaped like a gate, having a plurality of pillars 3 a, for example four pillars, and the lower portions of the pillars are firmly fixed on the upper surface portions of the base 1 .
- the main frame 3 supports the vertically slidable frame 4 , the rotatable cylindrical holder 5 , the tool supporting cylinder 6 , the spindle 7 , the tool 8 , servo motors 93 to 95 and others.
- the vertically slidable frame 4 includes a vertically slide mechanism 41 , a supporting plate member 4 a, and a plurality of Z-axis servo motors 93 .
- the vertically slidable frame 4 is supported on the pillars 3 a through the vertically slide mechanism 41 in such a way that the tool 8 is slidable in a vertical direction (Z-axial direction) along the pillars 3 a.
- the Z-axis servo motors 93 are provided on upper frame members of the main frame 3 near the pillows 3 a to rotate screw shafts 93 a so as to move engaging portions of the supporting plate member 4 a in the vertical direction.
- the vertically slidable frame 4 corresponds to a vertically moving mechanism of the present invention.
- the supporting frame member 4 a is formed to have a rectangular shape which is provided with a cylindrical portion 4 b to receive the rotatable cylinder 5 through bearings 53 arranged between the inner cylindrical surface of the cylindrical portion 4 b and the outer circumferential portion of a rotatable cylindrical holder 51 of the rotatable cylinder 5 .
- the cylindrical portion 4 b has a through-hole 4 c whose center axis Q is perpendicular to the base 1 and the horizontally slidable table 2 .
- the rotatable cylinder 5 includes the rotatable cylindrical holder 51 and a cylinder 52 .
- the rotatable cylindrical holder 51 is provided at its upper end portion with an enlarged disc portion 51 a with gear teeth 51 b on the outer circumferential portion thereof.
- the gear teeth 51 b are engaged with a worm 54 that is driven by a ⁇ -axis servo motor 94 so that the rotatable cylindrical holder 51 can rotate around the center axis Q relative to the supporting frame member 4 a.
- the ⁇ -axis servo motor 94 is fixed on the supporting frame member 4 a.
- the diameter of the enlarged disc portion 51 b is larger than that of the through-hole 4 c, so that the rotatable cylindrical holder 51 is inserted into the through-hole 4 c from upper side thereof.
- the rotatable cylindrical holder 51 is provided with a through-hole 51 c whose center axis S is inclined at the angle ⁇ to the center line Q of the through-hole 4 c of the cylindrical portion 4 b of the supporting frame member 4 a.
- the angle ⁇ is set to correspond to an advance angle of the tool 8 .
- the cylinder 52 is provided with a flange portion 52 a at its lower end portion, and the cylinder 52 is inserted into the through-hole 51 c from a lower side thereof.
- the flange portion 52 a is rotatably supported under the supporting frame member 4 a, being sandwiched by a tapered seat member 4 d and a lower tapered holding member 4 e.
- the cylinder 52 can be detached from the supporting frame member 4 a and the rotatable cylindrical holder 51 by removing the lower tapered holding member 4 e and pulling the cylinder 52 downward.
- the rotatable cylindrical holder 51 may be provided with the through-hole 51 c having the angle ⁇ different from that of the first embodiment.
- the rotatable cylindrical holders 51 may be replaced from that of the first embodiment to another one.
- the rotatable cylinder 5 corresponds to a direction changing mechanism of the present invention.
- the tool supporting cylinder 6 is received in the slanted cylinder 52 to rotatably support the spindle 7 , which penetrates through the tool supporting cylinder 6 .
- the top portion of the spindle 7 is connected with an S-axis servo motor 95 , and the lower end portion thereof is provided with the chuck 7 that can cramp the tool 8 .
- the tool 8 has a tool main body 81 shaped like a cylinder object and it is provided on the lower end portion of the tool main body 81 with a pin (probe or nib) 82 that is smaller in diameter than the tool main body 81 as shown in FIG. 2 .
- the cylindrical side surface of the tool main body 81 and the pin 82 are continuously connected by a shoulder surface 83 of the tool 8 .
- FIG. 2 shows the tool 8 moving in a direction indicated by an arrow G to weld the work piece 10 .
- the length of the pin 82 is set to be slightly less than the weld depth required and the pin 82 penetrates the work piece 10 , being rotated.
- a lower portion of the shoulder surface 83 of the inclined tool main body 81 is pressed on the top surface of the work piece 10 to rub the upper portion thereof.
- the vertical center axis Q passes through the center point O of the shoulder surface 83 , where the center point O is appropriately on the top surface of the work piece 10 .
- the spindle 7 and the tool 8 can be rotated around their center axis S by the S-axis servo motor 95 , they can be rotated around the center point O by the rotatable cylinder 5 that is driven by the ⁇ -axis servo motor 94 through the gear teeth 51 b and the worm 54 .
- the latter rotation movement is a gyro motion of the center axis S around the center point O and the center axis Q.
- the controller 9 is placed at the outer side of the left portion of the main frame 3 in FIG. 1 and on the right portion of the base 1 .
- the controller 9 is electrically connected to not-shown sensors, not-shown switches, the servo motors 91 to 95 , and so on. As shown in FIG.
- the controller 9 is equipped with an X-axis servo amplifier 91 a, a Y-axis servo amplifier 92 a, a Z-axis servo amplifier 93 a, a ⁇ -axis servo amplifier 94 a and an S-axis servo amplifier 95 a, which drive and control the X-axis servo motor 91 , the Y-axis servo motor 92 , the Z-axis servo motor 93 , the ⁇ -axis servo motor 94 and the S-axis servo motor 95 , respectively.
- the controller 9 controls the servo amplifiers 92 a to 95 a to output controlled electric power to the servo motors 92 to 95 , respectively.
- the drive rotation speed of the S-axis servo motor 95 is largely higher than those of the other servo motors 92 to 94 .
- the X-axis servo motor 91 , the Y-axis servo motor 92 , the X-axis servo amplifier 91 a, and the Y-axis servo amplifier 92 a correspond to the horizontally moving mechanism of the present invention.
- the Z-axis servo motor 93 , and the Z-axis servo motor 93 correspond to the vertically moving mechanism of the present invention.
- the ⁇ -axis servo amplifier 94 a and the ⁇ -axis servo motor 94 correspond to the direction changing mechanism of the present invention.
- the S-axis servo amplifier 95 a and the S-axis servo motor 95 correspond to the rotating mechanism of the present invention.
- the controller 9 executes servo-motor control according to a time chart shown in FIG. 4 when the portions to be jointed of the work piece 10 are formed in a rectangle shape consisting of a first straight line portion 11 , a second straight line portion 12 perpendicular to the first straight line portion 11 , a third straight line portion 13 parallel to the first straight line portion 11 , a fourth straight line portion 14 parallel to the second straight line portion 12 , and first to fourth square corners C 1 to C 4 that connect the adjacent straight line portions 11 to 14 , respectively, as shown in FIG. 5 .
- a stat point and an end point of the movement of the tool 8 are the same point indicated by F in FIG. 5 , and the tool 8 is moved according to the arrows shown in FIG. 5 , being turned at the first to fourth square corners C 1 to C 4 .
- the work piece 10 having the above-described portions be joined is placed and clamped on the cramping table 2 a.
- the controller 9 starts to drive the X-axis servo motor 91 and the Y-axis servo motor 92 to move the cramping table 2 a on which the work piece 10 is cramped so that the tool 8 can be positioned at the start point F when the tool 8 is moved down.
- This X-axial and Y-axial positioning control is not shown in the time chart shown in FIG. 4 .
- the controller 9 starts to drive the S-axis servo motor 93 , and when its rotation speed becomes stable at a predetermined high rotation speed, the controller 9 starts the Z-axis servo motors 93 to drive the vertically slide mechanism 41 , so that the vertically slidable frame 4 moves down toward the work piece 10 .
- the tool 8 is moved down and pressed on the work piece 10 at the start point F in such a way that the pin 82 and a portion of the shoulder surface 83 of the tool main body 81 are inserted into the portions to be joined of the work piece 10 .
- the controller 9 stops the Z-axis servo motors 93 .
- the advance angle direction of the tool 8 has been set to be a right direction on the first straight line portion 11 in FIG. 5 by using the ⁇ -axis servo motor 94 .
- the controller 9 starts the X-axis servo motor 91 to drive the tool 8 , which is rotating around the center axis S at a predetermined constant speed, in the right direction in FIG. 5 along the right half portion of the first straight line portion 11 toward the first square corner C 1 .
- frictional heat is generated primarily between the pin 82 and the material of the work piece 10 and additionally between the shoulder surface 82 and the material of the work piece 10 due to mechanical mixing therebetween.
- the heat causes the stirred material to soften without reaching the melting point of the material, and the plasticized material flows to deform in the solid state, involving dynamic recrystallization of the base material.
- the rotation speed and the travel speed of the tool 8 is set as fast as possible to facilitate its productivity, within the upper limit where the travel speed and the rotation speed do not cause the temperature of the material of the work piece 10 to reach its melting point and they do not deteriorates the durability of the tool 8 .
- the controller 9 starts to decrease the rotation speed of the X-axis servo motor 91 down to zero to stop the X-axis directional movement of the tool 8 .
- the controller 9 starts to decrease the rotation speed of the S-axis servo motor 95 down to a predetermined lower speed.
- the controller 9 starts to drive the ⁇ -axis servo motor 94 to turn the rotatable cylindrical holder 51 together with the tool 8 90° in a counterclockwise direction in FIG. 5 .
- the tool 8 is turned in such a way that the center point O of the shoulder surface 83 moves along the portion to be jointed, namely a welded line expected.
- the controller 9 stops the ⁇ -axis servo motor 94 to end the rotation of the rotatable cylindrical holder 51 , so that the advance angle direction of the tool 8 is turned upward in FIG. 5 at the first square corner C 1 .
- the welding trace at the first square corner C 1 is actually not 90°, the plastic flow of the material at the first square corner C 1 occurs in a certain area because the pin 82 and the shoulder surface 83 have certain mixing widths. Therefore, the portions at the first square corner C 1 are surely welded and joined.
- the rotation speed of the S-axis servo motor 95 is increased up to the predetermined high speed as the Y-axis servo motor 92 starts to drive the tool 8 so that the tool 8 can move along the second straight line portion 12 . Then the tool 8 moves near the second square corner C 2 at the predetermined constant speed, rotating at the predetermined high rotation speed, along the second straight line portion 12 to stir the material thereof.
- the controller 9 starts to decrease the rotation speed of the Y-axis servo motor 92 down to zero to stop the Y-axis directional movement of the tool 8 .
- the controller 9 starts to decrease the rotation speed of the S-axis servo motor 95 down to the predetermined lower speed.
- the controller 9 starts to drive the ⁇ -axis servo motor 94 to turn the rotatable cylindrical holder 51 together with the tool 8 90° in the counterclockwise direction in FIG. 5 . Accordingly, the tool 8 is turned in such a way that the center point O of the shoulder surface 83 moves along the portion to be jointed.
- the controller 9 stops the ⁇ -axis servo motor 94 , so that the advance angle direction of the tool 8 is turned in the left direction in FIG. 5 at the second square corner C 2 .
- the rotation speed of the S-axis servo motor 95 is returned to the predetermined high rotation speed, and the X-axis servo motor 91 starts to rotate in the rotational direction opposite to the rotational direction (backward direction) at the first straight line portion 11 so that the tool 8 moves along the third straight line portion 13 toward the third square corner C 3 at the predetermined constant speed, rotating at the predetermined high speed to stir the material thereof.
- the rotation speed (the absolute value) of the X-axis servo motor 91 is decreased to zero and the rotation speed of the S-axis servo motor 95 is also decreased to the predetermined lower speed.
- the ⁇ -axis servo motor 94 starts to drive to turn the rotatable cylinder holder 51 90° in the counterclockwise direction, that is, to the fourth square corner C 4 at the third square corner C 3 .
- the controller 9 stops the ⁇ -axis servo motor 94 , so that the advance angle direction of the tool 8 is turned in the downward direction in FIG. 5 at the third square corner C 3 .
- the rotation speed of the S-axis servo motor 95 is returned to the predetermined high rotation speed, and the Y-axis servo motor 92 starts to rotate in the rotational direction opposite to the rotational direction at the second straight line portion 12 so that the tool 8 moves along the fourth straight line portion 13 toward the fourth square corner C 4 at the predetermined constant speed, rotating at the predetermined high speed to stir the material thereof.
- the rotation speed (the absolute value) of the Y-axis servo motor 92 is decreased to zero and the rotation speed of the S-axis servo motor 95 is also decreased to the predetermined lower speed.
- the ⁇ -axis servo motor 94 starts to drive to turn the rotatable cylinder holder 51 90° in the counterclockwise direction, that is, to the first square corner C 1 at the fourth square corner C 4 .
- the controller 9 stops the ⁇ -axis servo motor 94 , so that the advance angle direction of the tool 8 is turned in the right direction in FIG. 5 at the fourth square corner C 4 .
- the rotation speed of the S-axis servo motor 95 is returned to the predetermined high rotation speed, and the X-axis servo motor 91 starts to rotate in the same direction as that at the first straight line portion 11 so that the tool 8 moves along the first straight line portion 11 toward the first square corner C 1 at the predetermined constant speed, rotating at the predetermined high speed to stir the material thereof.
- the X-axis servo motor 91 is stopped when the tool 8 reaches the end point F, which corresponds to the start point, and stirs the material thereof. Then the Z-axis servo motor 93 is rotated in the rotational direction opposite to the rotational direction in which the vertically slidable frame 4 is moved downward. This moves the vertically slidable frame 4 with the tool 8 upward to depart from the work piece 10 . Then the S-axis servo motor 95 is stopped, so that the rotational movement of the tool 8 around the center axis S thereof also ends. Incidentally, the ⁇ -axis servo motor 94 is then turned in the opposite direction so as to prepare the next welding.
- the friction stir welding method and the friction stir welding method of the first embodiment has the following advantages.
- the rotation speed of the tool 8 is decreased at the square corners C 1 to C 4 , being turned to change the travel direction of the tool 8 , to be lower than those at the first to fourth straight line portions 11 to 14 of the work piece 10 , where the square corners C 1 to C 4 continuously connect the adjacent straight line portions 11 to 14 .
- the temperature of the material of the jointed portions at the square corners C 1 to C 4 can be avoided from reaching the melting point, and the tool 8 can be avoided from the deterioration in the durability thereof due to too high temperature thereof, although the tool 8 is moved as fast as possible to accelerate the productivity.
- the tool 8 is turned at the square corners C 1 to C 4 in such a way that the center axis S of the tool main body 81 turns around the center point O of the shoulder surface 83 of the tool main body 81 and also around the center axis Q, which is called as the gyro movement.
- one, which is driven, of the X-axis servo motor 91 and the Y-axis servo motor 2 is stopped to decrease the travel speed of the tool 8 when the tool 8 moves near the square corners C 1 to C 4 .
- the rotation speed of the S-axis servo motor 95 starts to be decreased at the same time when the rotation speed of driven one starts to decrease.
- the ⁇ -axis servo motor 94 starts to drive the tool 8 to turn when the tool 8 reaches the square corners C 1 to C 4 .
- the friction stir welding method of the second embodiment is carried out by using the friction stir welding device of the first embodiment.
- the shape of the portion to be joined of a work piece 10 is different from that of the first embodiment. Accordingly, the control of the tool 8 by using the servo motors 91 to 95 is slightly different from that of the first embodiment.
- FIG. 6 shows the shape of the portion to be joined of the work piece 10 in the second embodiment.
- the shape thereof is formed like a rectangular shape, which consists of a first straight line portion 11 , a second straight line portion 12 perpendicular to the first straight line portion 11 , a third straight line portion 13 parallel to the first straight line portion 11 , a fourth straight line portion 14 parallel to the second straight line portion 12 , and first to fourth small round corners D 1 to D 4 that connect the adjacent straight line portions 11 to 14 , respectively, as shown in FIG. 6 .
- the controller 9 executes servo-motor control according to a time chart shown in FIG. 7 when the portions to be jointed of the work piece 10 are formed in a rectangle shape consisting of a first straight line portion 11 , a second straight line portion 12 perpendicular to the first straight line portion 11 , a third straight line portion 13 parallel to the first straight line portion 11 , a fourth straight line portion 14 parallel to the second straight line portion 12 , and first to fourth small round corners D 1 to D 4 that connect the adjacent straight line portions 11 to 14 , respectively, as shown in FIG. 6 .
- a stat point and an end point of the movement of the tool 8 are the same point indicated by F in FIG. 6 , and the tool 8 is moved according to the arrows shown in FIG. 6 , being turned at the first to fourth small round corners D 1 to D 4 .
- the work piece 10 having the above-described portions be joined is placed and clamped on the cramping table 2 a.
- the controller 9 starts to drive the X-axis servo motor 91 and the Y-axis servo motor 92 to move the cramping table 2 a on which the work piece 10 is cramped so that the tool 8 can be positioned at the start point F when the tool 8 is moved down.
- This X-axial and Y-axial positioning control is not shown in the time chart shown in FIG. 7 .
- the controller 9 starts to drive the S-axis servo motor 93 , and when its rotation speed becomes stable at a predetermined high rotation speed, the controller 9 starts the Z-axis servo motors 93 to drive the vertically slide mechanism 41 , so that the vertically slidable frame 4 moves down toward the work piece 10 .
- the tool 8 is moved down and pressed on the work piece 10 at the start point F in such a way that the pin 82 and a portion of the shoulder surface 83 of the tool main body 81 are inserted into the portions to be joined of the work piece 10 .
- the controller 9 stops the Z-axis servo motors 93 .
- the advance angle direction of the tool 8 has been set to be a right direction on the first straight line portion 11 in FIG. 6 by using the ⁇ -axis servo motor 94 .
- the controller 9 starts the X-axis servo motor 91 to drive the tool 8 , which is rotating around the center axis S at a predetermined constant speed, in the right direction in FIG. 6 along the right half portion of the first straight line portion 11 toward the first small round corner D 1 .
- frictional heat is generated primarily between the pin 82 and the material of the work piece 10 and additionally between the shoulder surface 82 and the material of the work piece 10 due to mechanical mixing therebetween.
- the heat causes the stirred material to soften without reaching the melting point of the material, and the plasticized material flows to deform in the solid state, involving dynamic recrystallization of the base material.
- the rotation speed and the travel speed of the tool 8 is set as fast as possible to facilitate its productivity, within the upper limit where the travel speed and the rotation speed do not cause the temperature of the material of the work piece 10 to reach its melting point and they do not deteriorates the durability of the tool 8 .
- the controller 9 starts to rapidly decrease the rotation speed of the X-axis servo motor 91 to an intermediate level speed, and it gradually decreases the rotation speed from the start portion of the first small round corner D 1 to the end portion thereof.
- the rotation speed of the X-axis servo motor 91 becomes zero at the end portion of the first small round corner D 1 .
- the controller 9 starts to drive the Y-axis servo motor 92 in such a way that the rotation speed of Y-axis servo motor 92 gradually increases up to an intermediate level speed at the end portion of the first small round corner D 1 .
- controller 9 drives the ⁇ -axis servo motor 94 at a constant speed at the first small round corner D 1 .
- the tool 8 moves around along the portion to be joined of the work piece 10 to turn 90° in a counterclockwise direction in FIG. 6 .
- the controller 9 decreases the rotation speed down to a predetermined lower speed before and near the first small round corner D 1 , then it maintains the predetermined lower speed at the first small round corner D 1 .
- the tool 8 is turned in such a way that the center point O of the shoulder surface 83 moves quarter round along the portion to be jointed, namely a welded line expected.
- the controller 9 stops the ⁇ -axis servo motor 94 to stop the rotation of the rotatable cylindrical holder 51 , so that the advance angle direction of the tool 8 is turned upward in FIG. 6 at the first small round corner D 1 .
- the controller 9 When the tool 8 turned to the second small round corner D 2 at the first small round corner D 1 , the controller 9 rapidly drives the Y-axis servo motor 92 up to the predetermined higher rotation speed and it maintains this speed so that the tool 8 moves upward in FIG. 6 along the second straight line portion 12 . At the same time, the controller 9 drives the S-axis servo motor 95 up to the predetermined high rotation speed so as to rotate the tool 8 around the center axis S at high speed.
- the controller 9 rapidly decreases the rotation speed of the Y-axis servo motor 92 down to the intermediate level speed, then gradually decreasing the rotation speed of the Y-axis servo motor 92 from the start portion of the second small round corner D 2 to the end portion thereof.
- the controller 9 starts to drive the X-axis servo motor 91 in the rotational direction opposite to the rotational direction at the first straight line portion 11 so as to gradually increases the absolute value of its rotation speed up to an intermediate level speed from the start portion of the second small round corner D 2 to the end portion thereof.
- controller 9 drives the ⁇ -axis servo motor 94 at the constant speed while the tool 8 is on the second small round corner D 2 .
- the tool 8 is turned 90° in the counterclockwise direction in FIG. 6 to the third small round corner D 3 at the second small round corner D 2 .
- the controller 9 decreases the rotation speed of the
- S-axis servo motor 95 down to the predetermined lower speed, and then it maintains this speed while the tool 8 is on the second small round corner D 2 .
- the controller 9 starts to rapidly increase the absolute value of the rotation speed up to the predetermined constant rotation speed, then it maintains its rotation speed.
- the controller 9 drives the S-axis servo motor 95 to rapidly increase up to the predetermined high constant rotation speed, then maintaining this rotation speed.
- the tool 8 moves in the left direction in FIG. 6 along the third straight line portion 13 of the work piece 10 .
- the controller 9 rapidly decreases the absolute value of the rotation speed of the X-axis servo motor 91 down to the intermediate level speed, and it also decreases the S-axis servo motor 95 down to the predetermined lower rotation speed.
- the controller 9 gradually decreases the rotation speed of the X-axis servo motor 91 down to zero from the start portion of the third small round corner D 3 to the end portion thereof.
- the controller 9 starts to drive the X-axis servo motor 92 so that the absolute value of the rotation speed thereof is gradually increased up to the intermediate level speed at the end portion of the third small round corner D 3 .
- the controller 9 drives the ⁇ -axis servo motor 94 at the constant rotation speed from the start portion of the third small round corner D 3 to the end portion thereof.
- the tool 8 is turned 90° in the counterclockwise direction in FIG. 6 to the fourth small round corner D 4 at the third small round corner D 3 .
- the controller 9 increases the absolute value of the rotation speed of the Y-axis servo motor 92 up to the higher constant rotation speed, then maintaining this speed, to move the tool 8 downward in FIG. 6 so that the tool 8 travels along the third straight line portion 13 toward the fourth small round corner D 4 .
- the controller 9 rapidly increases the rotation speed f the S-axis servo motor 95 up to the predetermined higher constant rotation speed.
- the controller 9 rapidly decreases the absolute value of the rotation speed of the Y-axis servo motor 92 , and it also decreases the rotation speed of the S-axis servo motor 95 down to the predetermined lower rotation speed.
- the controller 9 starts to gradually increase the rotation speed of the X-axis servo motor 91 up to the intermediate level speed while the tool 8 moves from the start portion of the fourth small round corner D 4 to the end portion thereof.
- the controller 9 gradually decreases the rotation speed from the start portion of the fourth small round corner D 4 down to zero at the end portion thereof.
- the controller 9 drives the ⁇ -axis servo motor 94 to maintain the constant rotation speed.
- the tool 8 is turned 90° in the counterclockwise direction in FIG. 6 to the first small round corner D 1 at the fourth small round corner D 4 .
- the controller 9 decreases and maintains the rotation speed of the S-axis servo motor 95 while the tool 8 travels on the fourth small round corner D 4 .
- the controller 9 rapidly increases the rotation speed of the X-axis servo motor 91 up to the predetermined higher constant rotation speed from the end portion of the fourth small round corner D 4 , and then it maintains this rotation speed to near the end point F.
- the tool 8 moves along the first straight line portion 11 to the end point F.
- the S-axis servo motor 95 is rapidly increased up to and maintained at the predetermined constant rotation speed to stir the material of the work piece 10 .
- the controller 9 stops the X-axis servo motor 91 and then the Z-axis servo motor 93 is rotated in the opposite rotational direction, so that the vertically slidable frame 4 with the tool 8 moves upward to depart from the work piece 10 . Then the S-axis servo motor 9 is stopped. At this time, the jointing portions required of the work piece 10 have been welded, and the work piece 10 can be brought out of the cramping table 2 a. This is the end of the friction stir welding of the work piece 10 .
- the friction stir welding method and the friction stir welding method of the second embodiment has the following advantages.
- the rotation speed of the tool 8 is decreased at the small round corners D 1 to D 4 , being turned to change the travel direction of the tool 8 , to be lower than those at the first to fourth straight line portions 11 to 14 of the work piece 10 , where the small round corners D 1 to D 4 continuously connect the adjacent straight line portions 11 to 14 .
- the temperature of the material of the jointed portions at the small round corners D 1 to D 4 can be avoided from reaching the melting point, and the tool 8 can be avoided from the deterioration in the durability thereof due to too high temperature thereof, although the tool 8 is moved as fast as possible to accelerate the productivity.
- the tool 8 is turned at the small round corners D 1 to D 4 in such a way that the center axis S of the tool main body 81 turns around the center point O of the shoulder surface 83 of the tool main body 81 and also around the center axis Q, which is called as the gyro movement.
- the processing traces formed by the pin 83 and the shoulder surface 83 are prevented from departing from the portions to be joined of the work piece 10 at the small round corners D 1 to D 4 .
- the rotation speed of one, which is driven, of the X-axis servo motor 91 and the Y-axis servo motor 2 and the rotation speed of the S-axis servo motor 95 are decreased at the same time when the tool 8 moves near the small round corners D 1 to D 4 . Therefore, it can remove a lag time between the control time to decrease the travel speed of the tool 8 and the control time to decrease the rotation speed of the tool 8 . This can shorten welding time, suppressing the temperature rise in the tool 8 and the portions to be joined at the small round corners D 1 to D 4 .
- the rotation speed of the other thereof is gradually increased, the ⁇ -axis servo motor 94 being driven, while the rotation speed of the driven one is gradually decreased at the first to fourth small round corners D 1 to D 4 .
- This enables the tool 8 to move square round along the first to fourth small round corners D 1 to D 4 .
- the vertical slidable frame 4 , the rotatable cylinder and so on may be replaced to the structures different from that of the first embodiment shown in FIG. 1 .
- the portions to be joined by using the friction stir welding method of the present invention may be different as long as they have a corner with a smaller curvature that connects two portions with larger curvatures.
- the corner with the smaller curvature includes the square corners C 1 to C 4 in the first embodiment and the small round corners D 1 to D 4 in the second embodiment.
- the portion with the larger curvature includes a straight line portion because the curvature of the straight line is unlimited.
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Abstract
Description
- 1. Field of the Invention
- The present invention relates to a friction stir welding method and its welding device in which jointing portions to be jointed of metal work piece are stirred to be flown in a plastic state due to friction heat generated by stirring and then the metal structure of the jointing portions is cooled down to be unified.
- 2. Description of the Related Art
- Friction stir welding is a solid-state joining process without using fusion or filler materials, thereby the original metal characteristics being maintained to be unchanged as far as possible.
- A conventional friction stir welding method of this kind is disclosed in Japanese Patent NO. 4215179. This prior friction stir welding method has a tool with a small pin or nib, a drive electric motor that rotates the tool, an air cylinder that presses the tool on jointing portions of a work piece, and slide mechanisms that moves the tool on a horizontal surface (X-axial direction and Y-axial direction) and in a vertical direction (Z-axial direction). The tool has a shoulder portion, which is larger in radiator than the pin. The shoulder and the pin are pressed on the jointing portions, being rotated, so as to be inserted into them, and the tool is moved along the jointing portions in a state where a center axis of the tool is slanted along the moving direction so that the pin side is positioned forward.
- However, in the above known conventional friction stir welding method, there is a problem in that the joining temperature in the jointing portions might reach the melting points of the metals and/or the durability of the pin deteriorates due to the friction stir welding that is carried out at the jointing portions in a case where the straight sections are contacted with each other through a square corner or through a small round corner.
- The reason is as follows. Normally the tool and pin are rotated at a constant speed and they are moved along a weld line (the portions to be jointed) of work piece at a constant speed, where the rotating pin penetrates the portions to be jointed to the depth slightly less than the weld depth required and the rotating tool shoulder is in contact with the portions to be joined. This mechanical mixing process generates heat, which causes the stirred material to soften without reaching its melting point.
- When the above-mentioned friction stir welding method is applied to a work piece which has straight sections connected with each other through a tight corner such as a square corner or a small round corner, the tool with pin is needed to change its moving direction at the corner. In this case, the tool with pin is rotated on the corner at a high total speed consisting of a rotating speed of the tool with pin and a direction changing speed thereof. Consequently, the heat generated on the corner rises to have a temperature higher than that generated at the straight sections of the work piece. This higher heat might cause the metal characteristics of the jointed portions to be changed due to the temperature higher than the melting point of the work piece, and/or it might deteriorate the durability of the pin.
- It is, therefore, a first object of the present invention to provide a friction stir welding method which overcomes the foregoing drawbacks and can weld portions to be joined of a work piece as fast as possible, avoiding the temperature of the portions to be jointed of the work piece from reaching the melting point of the work piece at a tight corner such as a square corner and a small round corner during friction stir welding.
- It is a second object of the present invention to provide a friction stir welding device which overcomes the foregoing drawbacks and can weld portions to be joined of a work piece as fast as possible, avoiding the temperature of the portions to be jointed of the work piece from reaching the melting point of the work piece at a tight corner such as a square corner and a small round corner during friction stir welding.
- According to a first aspect of the present invention there is provided a friction stir welding method in which a tool is moved being rotated along portions to be joined of a work piece, where the portions includes a corner with a smaller curvature that connect two portions with larger curvatures. The method comprising the steps of: setting the work piece on a supporting member, rotating the tool around a center axis of the tool, moving the tool toward the work piece to penetrate a portion of the tool into the work piece at the portions to be joined, and moving and turning the tool along the portions to be joined. A rotation speed of the tool around the center axis of the tool is decreased to be smaller at the corner with the smaller curvature than the rotation speed of the tool around the center axis of the tool at the portions with the larger curvatures.
- Therefore, the method of the present invention can weld the portions to be joined of the work piece as fast as possible, avoiding the temperature of the portions to be jointed of the work piece from reaching the melting point of the work piece at the corner with smaller curvature, namely the tight corner, during friction stir welding.
- According to a second aspect of the present invention there is provided a friction stir welding device for welding portions to be jointed of a work piece having a corner with a smaller curvature that connect two portions with larger curvatures. The device includes a supporting member that supports the work piece, a horizontally moving mechanism capable of moving the work piece on a horizontal surface, a vertically moving mechanism capable of vertically moving tool so as to penetrate in and depart from the portions to be joined, a direction changing mechanism capable of changing an advance angle direction of the tool whose center axis is inclined relative to an upper surface of the portions to be joined, a rotating mechanism capable of rotating the tool around the center axis of the tool, and a controller capable of controlling the horizontally moving mechanism, the vertically moving mechanism, the direction changing mechanism, and the rotating mechanism in such a way that a rotation speed of the tool around the center axis of the tool is decreased to be smaller at the corner with the smaller curvature than the rotation speed of the tool around the center axis of the tool at the portions with the larger curvatures.
- Therefore, the device of the present invention can weld the portions to be joined of the work piece as fast as possible, avoiding the temperature of the portions to be jointed of the work piece from reaching the melting point of the work piece at the corner with smaller curvature, namely the tight corner, during friction stir welding.
- Preferably, the corner with the smaller curvature is one of a round corner and a square corner. The welding stir method and its device of the present invention are suitable to the work pieces having such corners.
- Preferably, the tool has a tool main body having a cylindrical body shape, a pin that is provided on an end portion of the tool main body, and a shoulder surface provided on the end portion of the tool main body, and a travel direction of the tool is changed by a center axis of the tool being turned around a center point of the shoulder surface.
- Therefore, welding zone can be pretended from departing the portions to be joined.
- The objects, features and advantages of the present invention will become apparent as the description proceeds when taken in conjunction with the accompanying drawings, in which:
-
FIG. 1 is a front view showing a friction stir welding device that performs a friction stir welding method of a first embodiment according to the present invention; -
FIG. 2 is an exploded view showing a state where main parts, namely a pin and a tool shoulder, of the friction stir welding device shown inFIG. 1 are inserted into members to be jointed; -
FIG. 3 is a block diagram showing a controller that is used in the friction stir welding device shown inFIG. 1 and its control system; -
FIG. 4 is a time chart showing control contents that are carried out by the controller of the friction stir welding device shown inFIG. 1 ; -
FIG. 5 is a view showing a shape of portions to be joined of a work piece, to which the friction stir welding method of the first embodiment is applied; -
FIG. 6 is a view showing a shape of portions to be joined of a work piece, to which a friction stir welding method of a second embodiment according to the present invention is applied; and -
FIG. 7 is a time chart showing control contents that are carried out in the friction stir welding method of the second embodiment. - Throughout the following detailed description, similar reference characters and numbers refer to similar elements in all figures of the drawings, and the descriptions thereof are omitted for eliminating duplication.
- Referring to
FIG. 1 of the drawing, there is shown a friction stir welding device that can perform a friction stir welding method of a first preferred embodiment of the present invention. - The friction stir welding deice of the first embodiment is equipped with a
base 1, a horizontally slidable table 2, amain frame 3, a verticallyslidable frame 4, arotatable cylinder 5, aspindle 7 with a tool chuck 7 a, atool 8, and acontroller 9. - The
base 1 is a strong metal frame having like a rectangular shape, and it is firmly placed on a floor to support the main parts of the friction stir welding device thereon. - The horizontally slidable table 2 is placed on the
base 1 to fix awork piece 10 thereon, and it includes an X-axialdirectional slide mechanism 21 and a Y-axialdirectional slide mechanism 22 so that theslide mechanisms work piece 10 relative to thebase 1 on a horizontal surface. The X-axialdirectional slide mechanism 21 and the Y-axialdirectional slide mechanism 22 correspond to a horizontally moving mechanism of the present invention. - Incidentally, the X-axial direction is a left and right direction in
FIG. 1 , while the Y-axial direction is a front and rear direction perpendicular to the X-axis inFIG. 1 . - The X-axis directional movement of the horizontally slidable table 2 is executed by an
X-axis servo motor 91, which is provided at the outer side of the right portion of themain frame 3 and on the right portion of thebase 1 to move afirst carrier plate 21 a in the X-axial direction. Similarly, the Y-axis directional movement of the horizontally slidable table 2 is executed by a Y-axis servo motor 92, which is provided on the center front portion of thecarrier plate 21 a of the X-axisdirectional slide mechanism 21 to move thesecond carrier plate 22 a in the Y-axis direction. A cramping table 2 a is fixed on thesecond carrier plate 22 a to cramp thework piece 10 thereon. Theservo motors rotate screw shafts first carrier plate 21 a and thesecond carrier plate 22 a so that thecarrier plates screw shafts - Incidentally, the X-axial
directional slide mechanism 21 is arranged over the Y-axialdirectional slide mechanism 22 in the first embodiment, while the former may be arranged under the latter. The cramping table 22 a corresponds to a supporting member of the present invention. - The
main frame 3 is shaped like a gate, having a plurality ofpillars 3 a, for example four pillars, and the lower portions of the pillars are firmly fixed on the upper surface portions of thebase 1. Themain frame 3 supports the verticallyslidable frame 4, the rotatablecylindrical holder 5, thetool supporting cylinder 6, thespindle 7, thetool 8,servo motors 93 to 95 and others. - The vertically
slidable frame 4 includes a verticallyslide mechanism 41, a supportingplate member 4 a, and a plurality of Z-axis servo motors 93. The verticallyslidable frame 4 is supported on thepillars 3 a through the verticallyslide mechanism 41 in such a way that thetool 8 is slidable in a vertical direction (Z-axial direction) along thepillars 3 a. The Z-axis servo motors 93 are provided on upper frame members of themain frame 3 near thepillows 3 a to rotatescrew shafts 93 a so as to move engaging portions of the supportingplate member 4 a in the vertical direction. The verticallyslidable frame 4 corresponds to a vertically moving mechanism of the present invention. - The supporting
frame member 4 a is formed to have a rectangular shape which is provided with acylindrical portion 4 b to receive therotatable cylinder 5 throughbearings 53 arranged between the inner cylindrical surface of thecylindrical portion 4 b and the outer circumferential portion of a rotatablecylindrical holder 51 of therotatable cylinder 5. Thecylindrical portion 4 b has a through-hole 4 c whose center axis Q is perpendicular to thebase 1 and the horizontally slidable table 2. - The
rotatable cylinder 5 includes the rotatablecylindrical holder 51 and acylinder 52. The rotatablecylindrical holder 51 is provided at its upper end portion with anenlarged disc portion 51 a withgear teeth 51 b on the outer circumferential portion thereof. Thegear teeth 51 b are engaged with aworm 54 that is driven by a θ-axis servo motor 94 so that the rotatablecylindrical holder 51 can rotate around the center axis Q relative to the supportingframe member 4 a. The θ-axis servo motor 94 is fixed on the supportingframe member 4 a. The diameter of theenlarged disc portion 51 b is larger than that of the through-hole 4 c, so that the rotatablecylindrical holder 51 is inserted into the through-hole 4 c from upper side thereof. The rotatablecylindrical holder 51 is provided with a through-hole 51 c whose center axis S is inclined at the angle α to the center line Q of the through-hole 4 c of thecylindrical portion 4 b of the supportingframe member 4 a. The angle α is set to correspond to an advance angle of thetool 8. - The
cylinder 52 is provided with aflange portion 52 a at its lower end portion, and thecylinder 52 is inserted into the through-hole 51 c from a lower side thereof. Theflange portion 52 a is rotatably supported under the supportingframe member 4 a, being sandwiched by a tapered seat member 4 d and a lower tapered holding member 4 e. Thecylinder 52 can be detached from the supportingframe member 4 a and the rotatablecylindrical holder 51 by removing the lower tapered holding member 4 e and pulling thecylinder 52 downward. - Incidentally, the rotatable
cylindrical holder 51 may be provided with the through-hole 51 c having the angle α different from that of the first embodiment. In this case, the rotatablecylindrical holders 51 may be replaced from that of the first embodiment to another one. - The
rotatable cylinder 5 corresponds to a direction changing mechanism of the present invention. - The
tool supporting cylinder 6 is received in the slantedcylinder 52 to rotatably support thespindle 7, which penetrates through thetool supporting cylinder 6. - The top portion of the
spindle 7 is connected with an S-axis servo motor 95, and the lower end portion thereof is provided with thechuck 7 that can cramp thetool 8. - The
tool 8 has a toolmain body 81 shaped like a cylinder object and it is provided on the lower end portion of the toolmain body 81 with a pin (probe or nib) 82 that is smaller in diameter than the toolmain body 81 as shown inFIG. 2 . The cylindrical side surface of the toolmain body 81 and thepin 82 are continuously connected by ashoulder surface 83 of thetool 8. -
FIG. 2 shows thetool 8 moving in a direction indicated by an arrow G to weld thework piece 10. In this state, the length of thepin 82 is set to be slightly less than the weld depth required and thepin 82 penetrates thework piece 10, being rotated. At the same time, a lower portion of theshoulder surface 83 of the inclined toolmain body 81 is pressed on the top surface of thework piece 10 to rub the upper portion thereof. - The vertical center axis Q passes through the center point O of the
shoulder surface 83, where the center point O is appropriately on the top surface of thework piece 10. On the other hand, thespindle 7 and thetool 8 can be rotated around their center axis S by the S-axis servo motor 95, they can be rotated around the center point O by therotatable cylinder 5 that is driven by the θ-axis servo motor 94 through thegear teeth 51 b and theworm 54. The latter rotation movement is a gyro motion of the center axis S around the center point O and the center axis Q. - The
controller 9 is placed at the outer side of the left portion of themain frame 3 inFIG. 1 and on the right portion of thebase 1. Thecontroller 9 is electrically connected to not-shown sensors, not-shown switches, theservo motors 91 to 95, and so on. As shown inFIG. 3 , thecontroller 9 is equipped with anX-axis servo amplifier 91 a, a Y-axis servo amplifier 92 a, a Z-axis servo amplifier 93 a, a θ-axis servo amplifier 94 a and an S-axis servo amplifier 95 a, which drive and control theX-axis servo motor 91, the Y-axis servo motor 92, the Z-axis servo motor 93, the θ-axis servo motor 94 and the S-axis servo motor 95, respectively. Thecontroller 9 controls theservo amplifiers 92 a to 95 a to output controlled electric power to theservo motors 92 to 95, respectively. The drive rotation speed of the S-axis servo motor 95 is largely higher than those of theother servo motors 92 to 94. - The
X-axis servo motor 91, the Y-axis servo motor 92, theX-axis servo amplifier 91 a, and the Y-axis servo amplifier 92 a correspond to the horizontally moving mechanism of the present invention. The Z-axis servo motor 93, and the Z-axis servo motor 93 correspond to the vertically moving mechanism of the present invention. The θ-axis servo amplifier 94 a and the θ-axis servo motor 94 correspond to the direction changing mechanism of the present invention. The S-axis servo amplifier 95 a and the S-axis servo motor 95 correspond to the rotating mechanism of the present invention. - Next, the friction stir welding control carried out by the
controller 9 will be explained. - The
controller 9 executes servo-motor control according to a time chart shown inFIG. 4 when the portions to be jointed of thework piece 10 are formed in a rectangle shape consisting of a firststraight line portion 11, a secondstraight line portion 12 perpendicular to the firststraight line portion 11, a thirdstraight line portion 13 parallel to the firststraight line portion 11, a fourthstraight line portion 14 parallel to the secondstraight line portion 12, and first to fourth square corners C1 to C4 that connect the adjacentstraight line portions 11 to 14, respectively, as shown inFIG. 5 . - In this embodiment, a stat point and an end point of the movement of the
tool 8 are the same point indicated by F inFIG. 5 , and thetool 8 is moved according to the arrows shown inFIG. 5 , being turned at the first to fourth square corners C1 to C4. - At first, the
work piece 10 having the above-described portions be joined is placed and clamped on the cramping table 2 a. - The
controller 9 starts to drive theX-axis servo motor 91 and the Y-axis servo motor 92 to move the cramping table 2 a on which thework piece 10 is cramped so that thetool 8 can be positioned at the start point F when thetool 8 is moved down. This X-axial and Y-axial positioning control is not shown in the time chart shown inFIG. 4 . - Then, as shown in
FIG. 4 , thecontroller 9 starts to drive the S-axis servo motor 93, and when its rotation speed becomes stable at a predetermined high rotation speed, thecontroller 9 starts the Z-axis servo motors 93 to drive the vertically slidemechanism 41, so that the verticallyslidable frame 4 moves down toward thework piece 10. - Consequently, the
tool 8 is moved down and pressed on thework piece 10 at the start point F in such a way that thepin 82 and a portion of theshoulder surface 83 of the toolmain body 81 are inserted into the portions to be joined of thework piece 10. After thepin 82 and the portion of theshoulder surface 83 penetrates to a predetermined depth at the start point F, thecontroller 9 stops the Z-axis servo motors 93. Incidentally, the advance angle direction of thetool 8 has been set to be a right direction on the firststraight line portion 11 inFIG. 5 by using the θ-axis servo motor 94. - Then the
controller 9 starts theX-axis servo motor 91 to drive thetool 8, which is rotating around the center axis S at a predetermined constant speed, in the right direction inFIG. 5 along the right half portion of the firststraight line portion 11 toward the first square corner C1. As a result, frictional heat is generated primarily between thepin 82 and the material of thework piece 10 and additionally between theshoulder surface 82 and the material of thework piece 10 due to mechanical mixing therebetween. The heat causes the stirred material to soften without reaching the melting point of the material, and the plasticized material flows to deform in the solid state, involving dynamic recrystallization of the base material. - In this process, the rotation speed and the travel speed of the
tool 8 is set as fast as possible to facilitate its productivity, within the upper limit where the travel speed and the rotation speed do not cause the temperature of the material of thework piece 10 to reach its melting point and they do not deteriorates the durability of thetool 8. - When the
tool 8 reach near the first square corner C1, thecontroller 9 starts to decrease the rotation speed of theX-axis servo motor 91 down to zero to stop the X-axis directional movement of thetool 8. At the same time, thecontroller 9 starts to decrease the rotation speed of the S-axis servo motor 95 down to a predetermined lower speed. - In this state, when the
tool 8 moves at the first square corner C1, thecontroller 9 starts to drive the θ-axis servo motor 94 to turn the rotatablecylindrical holder 51 together with thetool 8 90° in a counterclockwise direction inFIG. 5 . Incidentally, in the first embodiment, thetool 8 is turned in such a way that the center point O of theshoulder surface 83 moves along the portion to be jointed, namely a welded line expected. - Then, the
controller 9 stops the θ-axis servo motor 94 to end the rotation of the rotatablecylindrical holder 51, so that the advance angle direction of thetool 8 is turned upward inFIG. 5 at the first square corner C1. - Although the welding trace at the first square corner C1 is actually not 90°, the plastic flow of the material at the first square corner C1 occurs in a certain area because the
pin 82 and theshoulder surface 83 have certain mixing widths. Therefore, the portions at the first square corner C1 are surely welded and joined. - When the
tool 8 is turned to the second square corner C2 at the first square corner C1, the rotation speed of the S-axis servo motor 95 is increased up to the predetermined high speed as the Y-axis servo motor 92 starts to drive thetool 8 so that thetool 8 can move along the secondstraight line portion 12. Then thetool 8 moves near the second square corner C2 at the predetermined constant speed, rotating at the predetermined high rotation speed, along the secondstraight line portion 12 to stir the material thereof. - When the
tool 8 reach near the second square corner C2, thecontroller 9 starts to decrease the rotation speed of the Y-axis servo motor 92 down to zero to stop the Y-axis directional movement of thetool 8. At the same time, thecontroller 9 starts to decrease the rotation speed of the S-axis servo motor 95 down to the predetermined lower speed. - In this state, when the
tool 8 moves at the second square corner C2, thecontroller 9 starts to drive the θ-axis servo motor 94 to turn the rotatablecylindrical holder 51 together with thetool 8 90° in the counterclockwise direction inFIG. 5 . Accordingly, thetool 8 is turned in such a way that the center point O of theshoulder surface 83 moves along the portion to be jointed. - Then, the
controller 9 stops the θ-axis servo motor 94, so that the advance angle direction of thetool 8 is turned in the left direction inFIG. 5 at the second square corner C2. The rotation speed of the S-axis servo motor 95 is returned to the predetermined high rotation speed, and theX-axis servo motor 91 starts to rotate in the rotational direction opposite to the rotational direction (backward direction) at the firststraight line portion 11 so that thetool 8 moves along the thirdstraight line portion 13 toward the third square corner C3 at the predetermined constant speed, rotating at the predetermined high speed to stir the material thereof. - When the
tool 8 reach near the third square corner C3, the rotation speed (the absolute value) of theX-axis servo motor 91 is decreased to zero and the rotation speed of the S-axis servo motor 95 is also decreased to the predetermined lower speed. The θ-axis servo motor 94 starts to drive to turn therotatable cylinder holder 51 90° in the counterclockwise direction, that is, to the fourth square corner C4 at the third square corner C3. - The
controller 9 stops the θ-axis servo motor 94, so that the advance angle direction of thetool 8 is turned in the downward direction inFIG. 5 at the third square corner C3. The rotation speed of the S-axis servo motor 95 is returned to the predetermined high rotation speed, and the Y-axis servo motor 92 starts to rotate in the rotational direction opposite to the rotational direction at the secondstraight line portion 12 so that thetool 8 moves along the fourthstraight line portion 13 toward the fourth square corner C4 at the predetermined constant speed, rotating at the predetermined high speed to stir the material thereof. - When the
tool 8 reach near the fourth square corner C4, the rotation speed (the absolute value) of the Y-axis servo motor 92 is decreased to zero and the rotation speed of the S-axis servo motor 95 is also decreased to the predetermined lower speed. The θ-axis servo motor 94 starts to drive to turn therotatable cylinder holder 51 90° in the counterclockwise direction, that is, to the first square corner C1 at the fourth square corner C4. - The
controller 9 stops the θ-axis servo motor 94, so that the advance angle direction of thetool 8 is turned in the right direction inFIG. 5 at the fourth square corner C4. The rotation speed of the S-axis servo motor 95 is returned to the predetermined high rotation speed, and theX-axis servo motor 91 starts to rotate in the same direction as that at the firststraight line portion 11 so that thetool 8 moves along the firststraight line portion 11 toward the first square corner C1 at the predetermined constant speed, rotating at the predetermined high speed to stir the material thereof. - The
X-axis servo motor 91 is stopped when thetool 8 reaches the end point F, which corresponds to the start point, and stirs the material thereof. Then the Z-axis servo motor 93 is rotated in the rotational direction opposite to the rotational direction in which the verticallyslidable frame 4 is moved downward. This moves the verticallyslidable frame 4 with thetool 8 upward to depart from thework piece 10. Then the S-axis servo motor 95 is stopped, so that the rotational movement of thetool 8 around the center axis S thereof also ends. Incidentally, the θ-axis servo motor 94 is then turned in the opposite direction so as to prepare the next welding. - At this time, the jointing portions required of the
work piece 10 have been welded, and accordingly thework piece 10 can be brought out of the cramping table 2 a. This is the end of the friction stir welding of thework piece 10. - As understood from the above-described explanation, the friction stir welding method and the friction stir welding method of the first embodiment has the following advantages.
- In the friction stir welding method and the friction stir welding device of the first embodiment, the rotation speed of the
tool 8 is decreased at the square corners C1 to C4, being turned to change the travel direction of thetool 8, to be lower than those at the first to fourthstraight line portions 11 to 14 of thework piece 10, where the square corners C1 to C4 continuously connect the adjacentstraight line portions 11 to 14. - Therefore, the temperature of the material of the jointed portions at the square corners C1 to C4 can be avoided from reaching the melting point, and the
tool 8 can be avoided from the deterioration in the durability thereof due to too high temperature thereof, although thetool 8 is moved as fast as possible to accelerate the productivity. - In the first embodiment, the
tool 8 is turned at the square corners C1 to C4 in such a way that the center axis S of the toolmain body 81 turns around the center point O of theshoulder surface 83 of the toolmain body 81 and also around the center axis Q, which is called as the gyro movement. - Therefore, the processing traces formed by the
pin 83 and theshoulder surface 83 are prevented from departing from the portions to be joined of thework piece 10 at the square corners C1 to C4. This ensures thetool 8 to easily move along the square corners C1 to C4 to weld the portions of thework piece 10 at the square corners C1 to C4. - In the first embodiment, one, which is driven, of the
X-axis servo motor 91 and the Y-axis servo motor 2 is stopped to decrease the travel speed of thetool 8 when thetool 8 moves near the square corners C1 to C4. The rotation speed of the S-axis servo motor 95 starts to be decreased at the same time when the rotation speed of driven one starts to decrease. Then the θ-axis servo motor 94 starts to drive thetool 8 to turn when thetool 8 reaches the square corners C1 to C4. - Therefore, it can remove a lag time between the control time to decrease the travel speed of the
tool 8 and the control time to decrease the rotation speed of thetool 8. This can shorten welding time, suppressing the temperature rise in thetool 8 and the portions to be joined at the square corners C1 to C4. - Next, a friction stir welding method of a second embodiment of the present invention will be described.
- The friction stir welding method of the second embodiment is carried out by using the friction stir welding device of the first embodiment.
- In the second embodiment, the shape of the portion to be joined of a
work piece 10 is different from that of the first embodiment. Accordingly, the control of thetool 8 by using theservo motors 91 to 95 is slightly different from that of the first embodiment. -
FIG. 6 shows the shape of the portion to be joined of thework piece 10 in the second embodiment. The shape thereof is formed like a rectangular shape, which consists of a firststraight line portion 11, a secondstraight line portion 12 perpendicular to the firststraight line portion 11, a thirdstraight line portion 13 parallel to the firststraight line portion 11, a fourthstraight line portion 14 parallel to the secondstraight line portion 12, and first to fourth small round corners D1 to D4 that connect the adjacentstraight line portions 11 to 14, respectively, as shown inFIG. 6 . - The
controller 9 executes servo-motor control according to a time chart shown inFIG. 7 when the portions to be jointed of thework piece 10 are formed in a rectangle shape consisting of a firststraight line portion 11, a secondstraight line portion 12 perpendicular to the firststraight line portion 11, a thirdstraight line portion 13 parallel to the firststraight line portion 11, a fourthstraight line portion 14 parallel to the secondstraight line portion 12, and first to fourth small round corners D1 to D4 that connect the adjacentstraight line portions 11 to 14, respectively, as shown inFIG. 6 . - In this embodiment, a stat point and an end point of the movement of the
tool 8 are the same point indicated by F inFIG. 6 , and thetool 8 is moved according to the arrows shown inFIG. 6 , being turned at the first to fourth small round corners D1 to D4. - At first, the
work piece 10 having the above-described portions be joined is placed and clamped on the cramping table 2 a. - The
controller 9 starts to drive theX-axis servo motor 91 and the Y-axis servo motor 92 to move the cramping table 2 a on which thework piece 10 is cramped so that thetool 8 can be positioned at the start point F when thetool 8 is moved down. This X-axial and Y-axial positioning control is not shown in the time chart shown inFIG. 7 . - Then, as shown in
FIG. 7 , thecontroller 9 starts to drive the S-axis servo motor 93, and when its rotation speed becomes stable at a predetermined high rotation speed, thecontroller 9 starts the Z-axis servo motors 93 to drive the vertically slidemechanism 41, so that the verticallyslidable frame 4 moves down toward thework piece 10. - Consequently, the
tool 8 is moved down and pressed on thework piece 10 at the start point F in such a way that thepin 82 and a portion of theshoulder surface 83 of the toolmain body 81 are inserted into the portions to be joined of thework piece 10. After thepin 82 and the portion of theshoulder surface 83 penetrates to a predetermined depth at the start point F, thecontroller 9 stops the Z-axis servo motors 93. Incidentally, the advance angle direction of thetool 8 has been set to be a right direction on the firststraight line portion 11 inFIG. 6 by using the θ-axis servo motor 94. - Then the
controller 9 starts theX-axis servo motor 91 to drive thetool 8, which is rotating around the center axis S at a predetermined constant speed, in the right direction inFIG. 6 along the right half portion of the firststraight line portion 11 toward the first small round corner D1. As a result, frictional heat is generated primarily between thepin 82 and the material of thework piece 10 and additionally between theshoulder surface 82 and the material of thework piece 10 due to mechanical mixing therebetween. The heat causes the stirred material to soften without reaching the melting point of the material, and the plasticized material flows to deform in the solid state, involving dynamic recrystallization of the base material. - In this process, the rotation speed and the travel speed of the
tool 8 is set as fast as possible to facilitate its productivity, within the upper limit where the travel speed and the rotation speed do not cause the temperature of the material of thework piece 10 to reach its melting point and they do not deteriorates the durability of thetool 8. - When the
tool 8 reach near the first small round corner D1, thecontroller 9 starts to rapidly decrease the rotation speed of theX-axis servo motor 91 to an intermediate level speed, and it gradually decreases the rotation speed from the start portion of the first small round corner D1 to the end portion thereof. The rotation speed of theX-axis servo motor 91 becomes zero at the end portion of the first small round corner D1. - On the other hand, the
controller 9 starts to drive the Y-axis servo motor 92 in such a way that the rotation speed of Y-axis servo motor 92 gradually increases up to an intermediate level speed at the end portion of the first small round corner D1. - In addition, the
controller 9 drives the θ-axis servo motor 94 at a constant speed at the first small round corner D1. - As a result, the
tool 8 moves around along the portion to be joined of thework piece 10 to turn 90° in a counterclockwise direction inFIG. 6 . - Further, the
controller 9 decreases the rotation speed down to a predetermined lower speed before and near the first small round corner D1, then it maintains the predetermined lower speed at the first small round corner D1. Incidentally, in the second embodiment, thetool 8 is turned in such a way that the center point O of theshoulder surface 83 moves quarter round along the portion to be jointed, namely a welded line expected. - Then, at the end portion of the first small round corner D1, the
controller 9 stops the θ-axis servo motor 94 to stop the rotation of the rotatablecylindrical holder 51, so that the advance angle direction of thetool 8 is turned upward inFIG. 6 at the first small round corner D1. - When the
tool 8 turned to the second small round corner D2 at the first small round corner D1, thecontroller 9 rapidly drives the Y-axis servo motor 92 up to the predetermined higher rotation speed and it maintains this speed so that thetool 8 moves upward inFIG. 6 along the secondstraight line portion 12. At the same time, thecontroller 9 drives the S-axis servo motor 95 up to the predetermined high rotation speed so as to rotate thetool 8 around the center axis S at high speed. - When the
tool 8 reaches near the second small round corner D2, thecontroller 9 rapidly decreases the rotation speed of the Y-axis servo motor 92 down to the intermediate level speed, then gradually decreasing the rotation speed of the Y-axis servo motor 92 from the start portion of the second small round corner D2 to the end portion thereof. - At the same time, the
controller 9 starts to drive theX-axis servo motor 91 in the rotational direction opposite to the rotational direction at the firststraight line portion 11 so as to gradually increases the absolute value of its rotation speed up to an intermediate level speed from the start portion of the second small round corner D2 to the end portion thereof. - In addition, the
controller 9 drives the θ-axis servo motor 94 at the constant speed while thetool 8 is on the second small round corner D2. - Accordingly, the
tool 8 is turned 90° in the counterclockwise direction inFIG. 6 to the third small round corner D3 at the second small round corner D2. - On the other hand, the
controller 9 decreases the rotation speed of the - S-
axis servo motor 95 down to the predetermined lower speed, and then it maintains this speed while thetool 8 is on the second small round corner D2. - When the
tool 8 reach the end portion the second small round corner D2, thecontroller 9 starts to rapidly increase the absolute value of the rotation speed up to the predetermined constant rotation speed, then it maintains its rotation speed. - At the same time, the
controller 9 drives the S-axis servo motor 95 to rapidly increase up to the predetermined high constant rotation speed, then maintaining this rotation speed. - Accordingly, the
tool 8 moves in the left direction inFIG. 6 along the thirdstraight line portion 13 of thework piece 10. - When the
tool 8 reaches near the third small round corner D3, thecontroller 9 rapidly decreases the absolute value of the rotation speed of theX-axis servo motor 91 down to the intermediate level speed, and it also decreases the S-axis servo motor 95 down to the predetermined lower rotation speed. - Then the
controller 9 gradually decreases the rotation speed of theX-axis servo motor 91 down to zero from the start portion of the third small round corner D3 to the end portion thereof. At the same time, thecontroller 9 starts to drive theX-axis servo motor 92 so that the absolute value of the rotation speed thereof is gradually increased up to the intermediate level speed at the end portion of the third small round corner D3. - The
controller 9 drives the θ-axis servo motor 94 at the constant rotation speed from the start portion of the third small round corner D3 to the end portion thereof. - Accordingly, the
tool 8 is turned 90° in the counterclockwise direction inFIG. 6 to the fourth small round corner D4 at the third small round corner D3. - Then the
controller 9 increases the absolute value of the rotation speed of the Y-axis servo motor 92 up to the higher constant rotation speed, then maintaining this speed, to move thetool 8 downward inFIG. 6 so that thetool 8 travels along the thirdstraight line portion 13 toward the fourth small round corner D4. In this travel movement, thecontroller 9 rapidly increases the rotation speed f the S-axis servo motor 95 up to the predetermined higher constant rotation speed. - When the
tool 8 reaches near the fourth small round corner D4, thecontroller 9 rapidly decreases the absolute value of the rotation speed of the Y-axis servo motor 92, and it also decreases the rotation speed of the S-axis servo motor 95 down to the predetermined lower rotation speed. - Then the
controller 9 starts to gradually increase the rotation speed of theX-axis servo motor 91 up to the intermediate level speed while thetool 8 moves from the start portion of the fourth small round corner D4 to the end portion thereof. Thecontroller 9 gradually decreases the rotation speed from the start portion of the fourth small round corner D4 down to zero at the end portion thereof. In addition, thecontroller 9 drives the θ-axis servo motor 94 to maintain the constant rotation speed. - As a result, the
tool 8 is turned 90° in the counterclockwise direction inFIG. 6 to the first small round corner D1 at the fourth small round corner D4. - On the other hand, the
controller 9 decreases and maintains the rotation speed of the S-axis servo motor 95 while thetool 8 travels on the fourth small round corner D4. - Then, the
controller 9 rapidly increases the rotation speed of theX-axis servo motor 91 up to the predetermined higher constant rotation speed from the end portion of the fourth small round corner D4, and then it maintains this rotation speed to near the end point F. - Accordingly the
tool 8 moves along the firststraight line portion 11 to the end point F. - In addition, the S-
axis servo motor 95 is rapidly increased up to and maintained at the predetermined constant rotation speed to stir the material of thework piece 10. - At the end point F, the
controller 9 stops theX-axis servo motor 91 and then the Z-axis servo motor 93 is rotated in the opposite rotational direction, so that the verticallyslidable frame 4 with thetool 8 moves upward to depart from thework piece 10. Then the S-axis servo motor 9 is stopped. At this time, the jointing portions required of thework piece 10 have been welded, and thework piece 10 can be brought out of the cramping table 2 a. This is the end of the friction stir welding of thework piece 10. - As understood from the above-described explanation, the friction stir welding method and the friction stir welding method of the second embodiment has the following advantages.
- In the friction stir welding method and the friction stir welding device of the second embodiment, the rotation speed of the
tool 8 is decreased at the small round corners D1 to D4, being turned to change the travel direction of thetool 8, to be lower than those at the first to fourthstraight line portions 11 to 14 of thework piece 10, where the small round corners D1 to D4 continuously connect the adjacentstraight line portions 11 to 14. - Therefore, the temperature of the material of the jointed portions at the small round corners D1 to D4 can be avoided from reaching the melting point, and the
tool 8 can be avoided from the deterioration in the durability thereof due to too high temperature thereof, although thetool 8 is moved as fast as possible to accelerate the productivity. - In the second embodiment, the
tool 8 is turned at the small round corners D1 to D4 in such a way that the center axis S of the toolmain body 81 turns around the center point O of theshoulder surface 83 of the toolmain body 81 and also around the center axis Q, which is called as the gyro movement. - Therefore, the processing traces formed by the
pin 83 and theshoulder surface 83 are prevented from departing from the portions to be joined of thework piece 10 at the small round corners D1 to D4. This ensures thetool 8 to easily move along the small round corners D1 to D4 to weld the portions of thework piece 10 at the small round corners D1 to D4. - In the second embodiment, the rotation speed of one, which is driven, of the
X-axis servo motor 91 and the Y-axis servo motor 2 and the rotation speed of the S-axis servo motor 95 are decreased at the same time when thetool 8 moves near the small round corners D1 to D4. Therefore, it can remove a lag time between the control time to decrease the travel speed of thetool 8 and the control time to decrease the rotation speed of thetool 8. This can shorten welding time, suppressing the temperature rise in thetool 8 and the portions to be joined at the small round corners D1 to D4. - In addition, the rotation speed of the other thereof is gradually increased, the θ-
axis servo motor 94 being driven, while the rotation speed of the driven one is gradually decreased at the first to fourth small round corners D1 to D4. This enables thetool 8 to move square round along the first to fourth small round corners D1 to D4. - While there have been particularly shown and described with reference to preferred embodiments thereof, it will be understood that various modifications may be made therein, and it is intended to cover in the appended claims all such modifications as fall within the true spirit and scope of the invention.
- For example, the vertical
slidable frame 4, the rotatable cylinder and so on may be replaced to the structures different from that of the first embodiment shown inFIG. 1 . - The portions to be joined by using the friction stir welding method of the present invention may be different as long as they have a corner with a smaller curvature that connects two portions with larger curvatures. The corner with the smaller curvature includes the square corners C1 to C4 in the first embodiment and the small round corners D1 to D4 in the second embodiment. The portion with the larger curvature includes a straight line portion because the curvature of the straight line is unlimited.
- The entire contents of Japanese Patent Application No. 2010-255486 filed Nov. 16, 2010 are incorporated herein by reference.
Claims (8)
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP2010-255486 | 2010-11-16 | ||
JP2010255486A JP5631162B2 (en) | 2010-11-16 | 2010-11-16 | Friction stir welding method |
Publications (2)
Publication Number | Publication Date |
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US20120118937A1 true US20120118937A1 (en) | 2012-05-17 |
US8181843B1 US8181843B1 (en) | 2012-05-22 |
Family
ID=45318805
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Application Number | Title | Priority Date | Filing Date |
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US13/280,576 Expired - Fee Related US8181843B1 (en) | 2010-11-16 | 2011-10-25 | Friction stir welding method and its device |
Country Status (4)
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US (1) | US8181843B1 (en) |
EP (1) | EP2452773B1 (en) |
JP (1) | JP5631162B2 (en) |
CN (1) | CN102463411B (en) |
Cited By (12)
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US20150224605A1 (en) * | 2014-02-10 | 2015-08-13 | Ms Spaichingen Gmbh | Stand for a machine |
US9446476B2 (en) * | 2012-02-09 | 2016-09-20 | Esab Ab | Backing arrangement for use in friction stir welding |
US20160318120A1 (en) * | 2013-12-27 | 2016-11-03 | Kawasaki Jukogyo Kabushiki Kaisha | Friction stir spot welding apparatus, friction stir spot welding method, and perpendicular-to-plane detection device for use in friction stir spot welding |
CN109048039A (en) * | 2018-09-30 | 2018-12-21 | 佛山市三水区诺尔贝机器人研究院有限公司 | A kind of universal head and its welding method of the weldering of curved surface agitating friction |
US20210268599A1 (en) * | 2018-07-19 | 2021-09-02 | Nippon Light Metal Company, Ltd. | Method for manufacturing liquid-cooled jacket |
US20210370433A1 (en) * | 2018-11-05 | 2021-12-02 | Nippon Light Metal Company, Ltd. | Method for manufacturing liquid-cooling jacket and friction stir welding method |
US20220143768A1 (en) * | 2019-02-25 | 2022-05-12 | Stirtec Gmbh | Method for joining or machining and apparatus therefor |
US20220331897A1 (en) * | 2021-04-16 | 2022-10-20 | Stirweld | Friction Stir Welding Head And Method Using The Same |
CN115464251A (en) * | 2022-10-12 | 2022-12-13 | 常州星宇车灯股份有限公司 | Automobile lamp vibration friction welding method based on pressing and vibration directions |
US20230053077A1 (en) * | 2020-01-24 | 2023-02-16 | Nippon Light Metal Company, Ltd. | Method for manufacturing liquid-cooling jacket and friction stir welding method |
US20230135888A1 (en) * | 2020-01-24 | 2023-05-04 | Nippon Light Metal Company, Ltd. | Method for manufacturing liquid-cooling jacket and friction stir welding method |
TWI820726B (en) * | 2022-05-25 | 2023-11-01 | 國立臺東專科學校 | Constant loading device for friction stir welding |
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JPH04215179A (en) | 1990-12-13 | 1992-08-05 | Nec Eng Ltd | Automatic cash dispenser |
JP4215179B2 (en) * | 1998-10-27 | 2009-01-28 | 川崎重工業株式会社 | Friction welding apparatus and friction welding method |
JP4286962B2 (en) * | 1999-04-21 | 2009-07-01 | 昭和電工株式会社 | Friction stir welding method |
JP3763734B2 (en) * | 2000-10-27 | 2006-04-05 | 株式会社日立製作所 | Panel member processing method |
JP4195206B2 (en) * | 2001-04-04 | 2008-12-10 | 株式会社日立製作所 | Friction stir welding equipment |
JP3751236B2 (en) * | 2001-08-24 | 2006-03-01 | 株式会社日立製作所 | Friction stir welding method |
US6913186B2 (en) * | 2003-09-11 | 2005-07-05 | The Boeing Company | Apparatus and method for friction stir welding with a variable speed pin |
CN2815583Y (en) * | 2005-03-15 | 2006-09-13 | 中国航空工业第一集团公司北京航空制造工程研究所 | Planar-two-dimensional weld seam mixing friction welding spindle head |
US7597237B2 (en) * | 2005-04-22 | 2009-10-06 | Regents Of The University Of Michigan | Rotatable multi-pin apparatus, and process for friction driven stitch welding and structural modification of materials |
US20100178526A1 (en) * | 2006-08-21 | 2010-07-15 | Osaka University | Process for working metal members and structures |
JP5092333B2 (en) * | 2006-10-02 | 2012-12-05 | 日本軽金属株式会社 | Joining method |
CN102672342B (en) * | 2006-10-02 | 2015-09-02 | 日本轻金属株式会社 | Joint method |
JP2008194732A (en) * | 2007-02-14 | 2008-08-28 | Nippon Light Metal Co Ltd | Jointing method |
-
2010
- 2010-11-16 JP JP2010255486A patent/JP5631162B2/en not_active Expired - Fee Related
-
2011
- 2011-08-09 CN CN201110227765.5A patent/CN102463411B/en not_active Expired - Fee Related
- 2011-10-25 US US13/280,576 patent/US8181843B1/en not_active Expired - Fee Related
- 2011-11-11 EP EP11188777.4A patent/EP2452773B1/en not_active Not-in-force
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US9446476B2 (en) * | 2012-02-09 | 2016-09-20 | Esab Ab | Backing arrangement for use in friction stir welding |
US20160318120A1 (en) * | 2013-12-27 | 2016-11-03 | Kawasaki Jukogyo Kabushiki Kaisha | Friction stir spot welding apparatus, friction stir spot welding method, and perpendicular-to-plane detection device for use in friction stir spot welding |
US9839973B2 (en) * | 2013-12-27 | 2017-12-12 | Kawasaki Jukogyo Kabushiki Kaisha | Friction stir spot welding apparatus, friction stir spot welding method, and perpendicular-to-plane detection device for use in friction stir spot welding |
US9296071B2 (en) * | 2014-02-10 | 2016-03-29 | Ms Spaichingen Gmbh | Stand for a machine |
US20150224605A1 (en) * | 2014-02-10 | 2015-08-13 | Ms Spaichingen Gmbh | Stand for a machine |
US11794271B2 (en) * | 2018-07-19 | 2023-10-24 | Nippon Light Metal Company, Ltd. | Method for manufacturing liquid-cooled jacket |
US20210268599A1 (en) * | 2018-07-19 | 2021-09-02 | Nippon Light Metal Company, Ltd. | Method for manufacturing liquid-cooled jacket |
US20240009753A1 (en) * | 2018-07-19 | 2024-01-11 | Nippon Light Metal Company, Ltd. | Method for manufacturing liquid-cooled jacket |
CN109048039A (en) * | 2018-09-30 | 2018-12-21 | 佛山市三水区诺尔贝机器人研究院有限公司 | A kind of universal head and its welding method of the weldering of curved surface agitating friction |
US20210370433A1 (en) * | 2018-11-05 | 2021-12-02 | Nippon Light Metal Company, Ltd. | Method for manufacturing liquid-cooling jacket and friction stir welding method |
US20220143768A1 (en) * | 2019-02-25 | 2022-05-12 | Stirtec Gmbh | Method for joining or machining and apparatus therefor |
US11919118B2 (en) * | 2019-02-25 | 2024-03-05 | Stirtec Gmbh | Method for joining or machining and apparatus therefor |
US20230053077A1 (en) * | 2020-01-24 | 2023-02-16 | Nippon Light Metal Company, Ltd. | Method for manufacturing liquid-cooling jacket and friction stir welding method |
US20230135888A1 (en) * | 2020-01-24 | 2023-05-04 | Nippon Light Metal Company, Ltd. | Method for manufacturing liquid-cooling jacket and friction stir welding method |
US20220331897A1 (en) * | 2021-04-16 | 2022-10-20 | Stirweld | Friction Stir Welding Head And Method Using The Same |
US12023753B2 (en) * | 2021-04-16 | 2024-07-02 | Stirweld | Friction stir welding head and method using the same |
TWI820726B (en) * | 2022-05-25 | 2023-11-01 | 國立臺東專科學校 | Constant loading device for friction stir welding |
CN115464251A (en) * | 2022-10-12 | 2022-12-13 | 常州星宇车灯股份有限公司 | Automobile lamp vibration friction welding method based on pressing and vibration directions |
Also Published As
Publication number | Publication date |
---|---|
US8181843B1 (en) | 2012-05-22 |
EP2452773B1 (en) | 2016-01-20 |
EP2452773A1 (en) | 2012-05-16 |
JP2012106250A (en) | 2012-06-07 |
JP5631162B2 (en) | 2014-11-26 |
CN102463411B (en) | 2015-08-05 |
CN102463411A (en) | 2012-05-23 |
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