JP3740125B2 - Friction stir welding apparatus and joining method thereof - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
  The present invention relates to a friction stir welding apparatus for joining single skin and double skin panels (two-sided hollow panels) used in manufacturing a structure such as a vehicle, an aircraft, a ship, and a building, and a joining method thereof. The present invention relates to a friction stir welding apparatus using a tool and a joining method thereof.
[0002]
[Prior art]
  For example, JP 7-505090 A (Patent Document 1) discloses a novel method for joining long materials as a solid-phase joining method by friction stirring. Such a joining method involves inserting a rotating tool made of a material substantially harder than the workpiece into a welded portion of the workpiece, and moving the rotating tool while rotating the rotating tool, the workpiece, This is a joining method in which workpieces are joined by plastic flow caused by frictional heat generated between the two. In this friction welding method, since the welded member can be joined in the solid phase state while the solid phase portion softened while being moved while rotating the rotating tool is integrated, there is no thermal distortion and the welding direction is substantially reduced. In particular, there is an advantage that even an infinitely long material can be continuously solid-phase bonded in the longitudinal direction. Furthermore, since the solid-phase bonding utilizing the plastic flow of metal caused by frictional heat between the rotating tool and the welding member, the bonding portion can be bonded without melting. Further, since the heating temperature is low, deformation after joining is small. Furthermore, since the joint is not melted, there are many advantages such as fewer defects.
[0003]
  Next, a rotary tool used for friction stir welding will be described. As disclosed in Patent Document 1, friction stir welding includes a probe type and a bobbin tool type rotary tool. The probe type tool plastically flows around the probe shaft by mechanical agitation of the probe shaft that penetrates the base material while applying frictional heat from the upper side of the base material with a shoulder. In this state, the rotary tool is moved along the joint line. As a result, the two materials are stirred and kneaded along the joint line while being plastically fluidized around the joint line, and moved to the rear side of the probe. As a result, the plastic flow material loses frictional heat at the rear side and rapidly cools and solidifies, so both panel plates are joined together with the materials mixed together, but with such a joining method, In order to generate frictional heat at the time of joining, it is necessary to press the rotary tool against the joining line side, and therefore a backing metal is used to cope with this reaction force. This backing metal is installed in close contact with the lower side of the face plate of the workpiece, and requires a large pressure.
[0004]
  In order to eliminate such drawbacks, a rotating tool called a bobbin tool 1 has been proposed as shown in FIG.
  Such a tool has a pair of shoulders 10 and 11 which are spaced apart so as to sandwich both front and back surfaces of the base material 3 to be joined.(Upper shoulder and lower shoulder)And a stirring shaft (pin shaft) 12 is provided between the pair of upper and lower shoulders 10 and 11, so that frictional heat can be generated on both surfaces of the joint surface, resulting in poor fusion on the lower side. Not only that, but since a pair of upper and lower shoulders 10 and 11 are subjected to the reaction force, a backing metal becomes unnecessary.
[0005]
  Various friction stir welding apparatuses using such a bobbin tool exist. For example, in Japanese Patent Laid-Open No. 2001-287053 (Patent Document 2), as shown in FIG. , A small-diameter pin portion (stirring shaft) 12 on the tool, and a shoulder larger than the pin portion 12 on both sides of the pin portion 12Da (Pressing member) 10 and 11, and the shawlDa 1The distance between 0 and 11 is the material to be joined (base material)3CThe material to be joined is reduced by the two shoulders 10 and 11.3CA technique for joining so as to sandwich the gap is disclosed.
[0006]
  Also, a friction stir welding apparatus using a bobbin tool that includes a lower pressing member and an upper pressing member and that has a variable gap between the pressing portions is known. For example, in Japanese Patent Application Laid-Open No. 2000-33484 (Patent Document 3), a coil spring is known. There is also a technique in which the lower surface pressing portion is made variable in the axial direction by using.
[0007]
[Patent Document 1]
  JP 7-505090 Gazette
[Patent Document 2]
  JP 2001-287053 A
[Patent Document 3]
  JP 2000-33484 A
[Problems to be solved by the invention]
[0008]
  However, both techniques have the following problems because the upper shoulder and the lower shoulder have the same diameter and rotate in the same direction.
  The first is a problem caused by equal shoulder diameters of the bobbin tool.
  When frictional heat input is performed with a bobbin tool with the same upper and lower shoulder diameters, the softened area that has been applied heat becomes symmetric in a cylindrical shape. As a result, a shearing force acts on the softened region portion of the base material sandwiched between the upper and lower shoulders, and the boundary between the base material and the softened region is easily sheared by the tool rotation.
[0009]
  Furthermore, at the beginning of friction stir welding, a hole into which the bobbin tool is inserted is drilled. Generally, the lower shoulder and the stirring shaft are connected with nuts, and the lower shoulder is removed. The shaft is inserted and the lower shoulder is connected to the nut after installation. However, it is difficult to connect the lower shoulder, such as a double skin panel (two-sided hollow panel), where the operator's hand is difficult to enter. It is.
[0010]
  For this reason, the hole diameter is made slightly larger than the outer diameter of the lower shoulder, and the joining is started with the stirring shaft fitted with a cylindrical filler of the same type as the hole diameter to close the hole. However, since the filling material and the hole are cylindrical, it is not possible to regulate the surface, so there is a risk of joining with a step at the start of joining, and high quality joining is difficult.
[0011]
  The second problem is that the upper shoulder 10 and the lower shoulder 11 rotate in the same direction as shown in FIG.
  That is,Upper shoulder 10 and lower shoulder 11The distance between the two upper shoulders is made smaller than the thickness of the material to be joined (base material) 3.10 and lower shoulder11, when the material to be joined 3 is sandwiched and rotated in the same direction 5A, 5A, as shown in the figure,The bobbin tool including the upper shoulder 10 and the lower shoulder 11 is advanced along the joining line.Even if the groove 5 located in front of the joining line is opened or the base materials 3 and 3 are fixed to each other by the fixing device 50, the base material 3 itself may be shifted back and forth as indicated by an arrow 51. is there.
[0012]
  SUMMARY OF THE INVENTION The present invention is intended to solve various problems in the case of joining using a bobbin tool in view of the problems of the prior art. The first problem is a softened region portion of a base material sandwiched between upper and lower shoulders. This is to prevent the possibility of tearing the softened area of the workpiece together with the shoulder.
  The second purpose is toUpper shoulder and lower shoulderIn this case, even when the workpiece is rotated so as to sandwich the material to be joined, it is possible to eliminate the possibility that the groove located in front of the joining line opens, or that the base material or the groove line shifts back and forth or from side to side.
  The third object is to join at the beginning of the friction stir welding in a state where the hole into which the bobbin tool is inserted is made small and the base material and the filler are easily flush with each other.
[0013]
[Means for Solving the Problems]
  In order to solve this problem, the present invention includes a lower pressing member and an upper pressing member, and the space between the pressing portions is fixed or variable.Stirring shaftThe two pressing parts by (probe shaft)MaterialIn a friction stir welding apparatus having a bobbin tool connected or opposed,
  The lower pressing member and the upper pressing member are made to have different diameters so that both the front and back surfaces of the base material are friction-heated, and the base material is in a position facing the base material that is in contact with the sliding surface in the vicinity of the outer periphery of the pressing member. A pressing mechanism is attached, and the two pressing members (hereinafter referred to as shoulders)The frictional heat input sliding portion in contact with the base material has a different heat capacity or has a different number of rotations, for example, the diameter or thickness of the lower pressing member is different from that of the upper pressing member, and both the front and back surfaces of the base material Different heat capacity for receiving heatTheIt is characterized by that.
[0014]
  Composed of upper shoulder and lower shoulderThe effect of varying the shoulder surface up and down (front and back) with different diameters or rotational speeds will be described with reference to FIG.
  As shown in FIG. 1 (B), when the tool 10 and 11 (shoulder) diameters are the same with the same rotation, the calorific value is the same, but the upper shoulder 10 releases heat to the processing machine spindle 90 side and goes to the upper shoulder 10. Therefore, the temperature of the lower shoulder 11 rises, and the amount of heat generated on the front and back surfaces of the base material 3 rises differently. As a result, the dent amount is smaller in the upper shoulder 10 than in the lower shoulder 11. Tend to be bigger.
  When it is desired to make the dent at the time of joining uniform, for example, as shown in FIG. 1A, the shoulder diameter of the lower shoulder 11 is reduced by reducing the diameter of the shoulder of the lower shoulder 11 or the length of the shoulder of the lower shoulder 11. It is better to increase the (thickness) and increase the heat capacity. Conversely, as shown in FIGS. 4B and 4D, the shoulder diameter of the lower shoulder 11 is increased to increase the heat generation amount on the back surface of the base material 3.You mayRemove the dent on the surface of the base material and make it flat or convexMay be.
  In the above operation, the rotating means of the upper shoulder 10 and the rotating means of the lower shoulder 11 are independently driven and controlled, and when the dents at the time of joining are made uniform, the rotational speed of the lower shoulder 11 is set to the upper shoulder 10. In order to reduce the dent on the surface of the base material and make it flat or convex, the rotational speed of the lower shoulder 11 may be made relatively higher than that of the upper shoulder 10.
[0015]
  The present invention also providesIf the shoulder diameter of the lower shoulder 11 is increased to increase the amount of heat generated on the back surface of the base material 3, the dent on the base material surface side can be eliminated.
  In this case, the shoulder is not necessarily cylindrical, but may be a taper circle or a reverse taper circle. In short, the shoulder surface that frictionally heats the base metal may be different in diameter or rotational speed on the top and bottom (front and back).
[0016]
  According to this invention, the diameter of the upper and lower shoulders of the bobbin tool is made different from each other or the number of rotations is made different so that the softening area in the vertical direction of the workpiece cross section becomes asymmetric and softening by clamping the workpiece of the shoulder at the start of joining. Even if a shear force is generated in the region, the force can be applied in a direction to prevent this.
  Furthermore, the present invention provides a base material presser at a position facing the base material on the outer peripheral side of the small-diameter side pressing member while making the lower side pressing member and the upper side pressing member have different diameters to frictionally heat the both sides of the base material. By attaching the mechanism, generation of shearing force in the softened region from the small diameter side to the large diameter side can be suppressed.
[0017]
  The second invention includes a lower pressing member and an upper pressing member, and the space between the pressing portions is fixed or variable.TurbulenceIn a friction stir welding apparatus having a bobbin tool in which the two pressing members are opposed to each other by a stirring shaft (probe shaft), the lower pressing member is connected to the stirring shaft, and the upper pressing member is loosely fitted to the stirring shaft. While being freely fitted, the rotation direction of the upper pressing member is set in the opposite direction with respect to the lower pressing member.
  Claim5The described invention specifies the method of the device invention,A bobbin tool comprising a lower pressing member and an upper pressing member, wherein the two pressing members are connected to or opposed to each other by a stirring shaft (probe shaft) fixed or variable between the pressing portions, and the bobbin tool is used as a base material While advancing along the base material joint line formed by abutting each other, on the base material joint lineAbove the base metal jointUpper pressing member located atRotating sliding contact and lower sidePress memberThan the rotating sliding movementOn both upper and lower surfaces of base material jointAdd frictional heat inputBase materialIn the friction stir welding method for joining by plastic flow of the joint,
  SaidRotating sliding movementThe direction is different between the lower side and the upper side.Rotating sliding movementDirection isThe front side of the joining line in the direction in which the bobbin tool advancesStirring is performed so as to face the surface.
[0018]
  According to this invention, as shown in FIG.Of the one base material and the other base material that are abutted along the base material joint line formed by abutting the base materials, the base material located on the upper side in the figure is the upper side. When the base material 3A and the base material positioned on the upper and lower sides of the figure are defined as the lower base material 3B, the upper base material 3A and the lower base material 3B are opposite to the joint line between the base materials 3A and 3B. The left and right sides of the end line extending in the longitudinal direction (in other words, both the left and right sides of the end line extending in the longitudinal direction of each base material positioned parallel to the joint line on both ends in the width direction of the base material orthogonal to the joint line) )Is constrained by the fixing member 50, and therefore the force generated by the rotation of the bobbin tools 10 and 11The direction ofIn the case of the same rotation direction, the upper shoulder 10CounterclockwiseIn the direction 5A of the lower shoulder 11However, the counterclockwise direction 5A in the same direction as the upper shoulder 10 is shown.Therefore, the base material becomes a force that works in a direction deviating back and forth as shown by an arrow 51 across the joining line 5.
  In this state,Along with the base material joining line formed by abutting the base materials, for example, the bobbin tool located at the joining line where the base materials are abutted with each other is advanced along the joining line so that the upper base material 3A and the lower side When joining with the base material 3B,Upper base material3AThe meat is too thinOneLower base material3BSince there is not enough meat, the upper base metal is sandwiched between the joining wires 5 without sufficient frictional heat input.3AAnd lower base material3BA step is formed between the upper and lower base plates, and the upper and lower base plates are not joined together with the joining line 5 interposed therebetween.
  On the other handThe figureAs shown in 5 (B)The upper shoulder 10 and the lower shoulder 11In the case of reverse rotation,UpIn the side shoulder 10CounterclockwiseDirection5AIn the lower shoulder 11,ClockwiseDirection5BAs shown in FIG. 5C, the base material has both the front and back surfaces of the base material with the joining line 5 interposed therebetween.(Upper and lower surfaces)The direction that is shifted back and forth on the side becomes the canceling direction, and the upper base material with the joining wire 5 interposed therebetween3AAnd lower base material3BThere is no step between the two and smooth joining is possible.
[0019]
  Moreover, according to this invention,Front and back sides (Upper and lower)When the pair of shoulders are sandwiched between the two shoulders and friction stir welding is performed, the upper shoulder is rotated in the reverse direction with respect to the lower shoulder and the stirring shaft.Therefore, at the position in front of the joining direction of the bobbin tool traveling along the base metal joint line, the upper shoulder and the lower shoulderSliding contact rotation direction is joiningOn the lineBy stirring to faceBobbin tool toolForce acts in a direction that narrows the groove in front of the joint lineTherefore, the groove located in front of the joint line does not open,MoreSaidJoining position rearIn the position where the joining ofTo apply force in the direction away from the joint line on both sides around the joint line,motherThe possibility of shifting the material and groove line back and forth can be eliminated and smooth joining is possible.
  In particular, when joining cylindrical materials having a semicircular cross section in the axial direction, there are many cases where they are in contact with each other at 180 ° symmetrical positions and have an end plate on the upper side. For this reason, since the deviation of the groove is likely to occur during the joining, it is very effective in preventing this deviation when the base material is a cylindrical body or other endless cylindrical body.
[0020]
  The third invention includes a lower pressing member and an upper pressing member, and the space between the pressing portions is fixed or variable.TurbulenceIn a friction stir welding method in which a base material is joined using a bobbin tool in which the two pressing members are connected to or opposed to each other by a stirrer shaft (probe shaft), a rotation restricting portion and an inner peripheral surface Friction stir after fitting the bobbin tool into the fitting hole in a state where the fitting hole provided with the axial direction restricting portion is provided and the filler to be fitted into the fitting hole is attached to the stirring shaft It is characterized by starting joining.
  That is, as a specific device, a lower pressing member and an upper pressing member are provided, and the pressing portionMaterialIn a friction stir welding apparatus provided with a bobbin tool in which the two pressing members are connected or opposed to each other by a fixed or variable stirring shaft (probe shaft),
  Lower side pressParts andUpper side pressElementThanSame diameter orThe filler that is formed into a small diameter and is fitted to the agitation shaft is pressed downward according to the shape of the fitting hole on the base material joining line start side.PartPress upward from material sidePartIt is characterized by having an axial direction restricting portion toward the material side.
  The rotation restricting portion may be a tooth shape such as a spline or an asymmetric shape such as an ellipse.
  Further, the axial direction restricting portion includes a step and a taper.
  According to this invention, since the rotation restricting portion is provided, the filler is rotated and softened together with the shaft, and furthermore, the friction stir welding can be started with the filler and the base material always flush with each other by the axial restricting portion.
  If the lower shoulder is made smaller in diameter, at the beginning of friction stir welding, the hole into which the bobbin tool is inserted can be made smaller, and the base material and the filler can be easily joined together with high quality. I can do it.
[0021]
DETAILED DESCRIPTION OF THE INVENTION
  Hereinafter, the present invention will be described in detail with reference to the embodiments shown in the drawings. However, unless otherwise specified, the dimensions, shapes, relative arrangements, and the like of the components described in this embodiment are merely illustrative examples and not intended to limit the scope of the present invention.
[0022]
  FIG. 4 is an embodiment of the present invention using the bobbin tool 1, and the upper shoulder 10 is a first hydraulic piston / cylinder 60 that applies a reaction force (load) that is small as if following the upper side of the workpiece (base material) 3. On the other hand, the lower shoulder 11 sandwiches the workpiece (base material) 3 on the upper shoulder 10 and applies a large reaction force (load) to generate a frictional force from the lower side. The bobbin tool 1 is connected to a piston / cylinder 62, and is driven to rotate in forward and reverse directions by a motor 72 and a reversing mechanism 82 incorporated therein.
[0023]
  More specifically, reference numeral 90 in the figure denotes a processing machine main shaft, which does not rotate. 9 is a bonding machine main body attached to the lower surface of the main shaft, and a cylindrical support outer frame 64 attached to the lower surface of the processing machine main shaft 90, and a first center attached to the upper central axis of the support outer frame 64. A hydraulic piston / cylinder 60; a support inner cylinder 66 suspended by a vertically movable support shaft connected to the hydraulic piston; and a second hydraulic piston / cylinder 62 built in the upper portion of the support inner cylinder 66; , A bobbin tool incorporated in a support cylinder below the second hydraulic piston / cylinder 62Mounting body70, a motor 72 is mounted around the bobbin tool attachment body 70, and the bobbin tool attachment body 70 is rotatably arranged with respect to the support inner cylinder 66.
[0024]
  The bobbin tool mounting body 70 receives the biasing displacement of the first hydraulic piston / cylinder 60 integrally with the support inner cylinder 66, and can move and displace in the Z-axis direction. 66, an upper shoulder mounting body 80 supported in 66, and a lower shoulder mounting shaft 78 penetrating through the upper shoulder 10 and having the lower shoulder 11 attached to the tip thereof via a pin shaft 12. The side shoulder mounting shaft 78 and the piston shaft 62B of the second hydraulic piston / cylinder 62 are connected via a bearing bearing 73, and move up and down on the support inner cylinder 66 regardless of the rotation of the lower shoulder mounting shaft 78 by the motor 72. The urging force of the second hydraulic piston / cylinder 62 is configured to be received through a freely supported piston shaft 62B.
  A reversing mechanism 82 for reversing the rotational force of the motor 72 is provided at a fitting portion between the lower shoulder mounting shaft 78 and the upper shoulder mounting body 80, and the lower shoulder mounting shaft 78 is connected to the piston shaft via the reversing mechanism 82. 62B is slidably connected to the lower shoulder 11 through the rotation direction of the motor 72 on the upper shoulder 10 side and the reversing mechanism.
  Although not shown, an independent motor may be attached in place of the reversing mechanism 82 so that the lower shoulder 11 and the upper shoulder 10 can independently control the rotation speed and the rotation direction. .
[0025]
  A ring-like engagement is provided at the facing position between the lower outer periphery of the support inner cylinder 66 and the lower inner periphery of the support outer frame 64 so that the support inner cylinder 66 can move up and down within a movement restricting range reduced in a step shape. A concave portion 88 and a ring-shaped engaging convex portion 89 are provided, and the hydraulic pistons / cylinders 60 and 62 of this embodiment are provided with hydraulic pressures 63A and 63B on both the upper and lower sides of the piston 61, and the pressure balance between them The shaft 61A is configured to move up and down. This facilitates control of copying and frictional pressure.
[0026]
  According to the friction stir welding apparatus, in the state where the workpiece (base material) 3 is sandwiched by the bobbin tool 1 (the lower shoulder 11 and the upper shoulder 10), the upper shoulder mounting body 80 and the reversing mechanism are firstly driven by the motor 72. After rotating in the opposite direction to the lower shoulder mounting shaft 78 connected via 82, the supporting inner cylinder 66 is suspended, and the upper shoulder 10 side is suspended via the piston shaft 61A and the supporting inner cylinder 66. In the first hydraulic piston / cylinder 60 biased by the pressure, a hydraulic pump (not shown) is driven so that the load on the upper shoulder 10 surface on the upper side of the workpiece (base material) 3 joint surface becomes 10 kgf.
  At the same time, in the second hydraulic piston / cylinder 62 that is built in the support inner cylinder 66 and is urged to the lower shoulder 11 side via the piston shaft 62B and the lower shoulder mounting shaft 78, the workpiece (base material) 3 is joined. A hydraulic pump (not shown) is driven so that the load of the lower shoulder 11 applied to the lower side of the surface becomes 200 kgf or more.
  At this time, the bonding machine main body 9 that rotatably supports the bobbin tool 1 includes a ring-shaped engagement concave portion 88 on the outer peripheral side of the support inner cylinder 66 and a ring-shaped engagement convex portion 89 on the inner peripheral side of the support outer frame 64. Supports vertical movement within the restricted range of movement.
[0027]
  The reason why the load on the lower shoulder 11 is controlled to be 200 kgf or more and the load applied to the upper shoulder 10 surface is significantly smaller than the load applied to the lower shoulder 11 is as follows.
  For example, when the base material 3 is a skin panel, since the joint structure of the joint portion is abutted, a gap (gap) is generated in the joint portion, but the plate on the lower side (hollow portion side) of the panel free end While increasing the thickness,Base material upper side and lower side (Front and back sides)By using the bobbin tool 1 to which frictional heat is input from the shoulder surface, the load applied to the lower shoulder 11 is greatly increased and friction stir welding is performed, so that heat input by frictional heat with the shoulder surface at the joint portion is performed. The lower softened part enters the bonding gap space, so that the upper side visible from the outside can be kept flat without generating any recesses, and the upper processing after bonding is basically unnecessary. For long objects like the body, the work is greatly simplified.
[0028]
  And like thisThe effect is,When the load applied to the upper shoulder 10 surface is made significantly smaller than the load applied to the lower shoulder 11 and a rotational rubbing motion is performed while applying a pressing force to both the front and back surfaces of the base material,Load on the lower shoulder 11Is significantly larger than the load on the lower shoulder 11While performing friction stir welding whileThe meat on the back side of the base metal softened by the rotary rubbing movement of the lower shoulderIn the gapAchieved by entering.
[0029]
  In the present invention, the lower shoulder 11 and the upper shoulder 10 are connected by the reversing mechanism 82 and rotated forward and backward. However, both may be configured so that the rotation can be controlled independently.
[0030]
  Further, according to the present embodiment, in the upper shoulder 10, the upper side of the workpiece (base material) 3 is the main function, so that the advantages of the air cylinder can be effectively utilized. That is, even in a joint in which the joint line is greatly curved in the vertical direction, the air cylinder has a smooth variation in the pressing force, and has better followability than the hydraulic cylinder.
  On the other hand, in the case of the lower shoulder 11 that requires a large pressing force due to smooth frictional heat input, it is preferable to use a hydraulic piston / cylinder.
[0031]
  FIG. 4 (B)These show the structure of the bobbin tool of FIG. 4 (A), and FIG.4 (C) is a figure which shows a softening area | region. 4 (B) and 4 (C), an upper shoulder 10 shown in the drawing is a first hydraulic piston / cylinder 60 (FIG. 4) that applies a reaction force (load) that is small as if it follows the upper side of the workpiece (base material) 3. 3 (A)), the diameter of which is d₁It is. On the other hand, the lower shoulder 11 is a second shoulder that applies a large reaction force (load) in order to generate a frictional force from the lower side with the workpiece (base material) 3 sandwiched between the upper shoulder 10 via the pin shaft 12. Is connected to a hydraulic piston / cylinder 62 of the same diameter.₂And larger diameter than upper shoulder 10 (d₂> D₁). As described above, these bobbin tools 1 are rotationally driven in opposite directions by the motor 72 and the reversing mechanism 82 incorporated therein.
[0032]
  In such an embodiment, the lower shoulder diameter d of the bobbin tool₂The diameter d of the upper shoulder 10 is large.₁Is small. When frictional heat input is performed with the bobbin tool 1 having different diameters of the upper and lower shoulders, the lower base of the softened region where the heat is input is d.₂And the top side is d₁The base material 3 moves up and down during the movement of the bobbin tool 1 in this state. In addition, even if the processing machine main shaft 90 supporting the bobbin tool 1 moves up and down, the softened region 4 portion of the base material 3 sandwiched between the upper and lower shoulders works in a direction to prevent the vertical movement. The shearing force generated in the softened region 4 of the workpiece can be suppressed.
[0033]
  Furthermore, this example is4As shown to (B), when a pair of shoulders 10 and 11 are pinched | interposed from the upper side and lower side of the to-be-joined material (base material) 3, and the friction stir welding is carried out, the upper shoulder 10 is made into the lower shoulder 11 and the stirring shaft (pin). When the rotation direction with respect to the shaft 12 is reversed and the agitation is performed so that the sliding contact rotation directions 5A and 5B face the front side of the groove 5 of the bonding line, the force in the direction in which the groove 5 in front of the bonding line is narrowed. In addition, since force is applied to both sides around the joining line even at the joining position rear 7 (see 7A and 7B), the groove 5 located in front of the joining line opens, the base material 3 and the groove line 5 Can eliminate the risk of shifting left and right.
  The stirring shaft (pin shaft) 12 is preferably constituted by a reverse screw (spiral direction in which an upward force is applied to the rotation of the main shaft).
[0034]
  When the upper shoulder 10 and the lower shoulder 11 and the stirring shaft (pin shaft) 12 are rotated in the reverse direction, as shown in FIG. The power is reversed back and forth on both the front and back sides with the joining line in between, and it is possible to prevent the front and back from shifting.
  In this case, the upper shoulder 10 is controlled to control the rotation speed of the lower shoulder 11, for example, the softened region 4 that has received heat is swelled at the bottom side of the lower side, and the top side is thinned up and down in an approximately upward truncated cone shape. It becomes asymmetric (a different diameter softening region that is symmetrical in the axial direction and has a larger diameter on the lower surface than the upper surface of the base material), and is similar to FIG.
  As shown in the right column of FIG. 5C, not only the upper shoulder 10 is rotated in the reverse direction of the lower shoulder 11 and the stirring shaft (pin shaft) 12 but also the motor 91, which is an independent motor 91, The rotation speed may be controlled in accordance with the rotation direction by controlling the rotation by the rotation control unit 93 in 92, thereby facilitating the control of the flatness and unevenness of the joint surface.
[0035]
  In particular, when cylindrical materials having a semicircular cross section are joined in the axial direction, since they are in contact with each other at 180 ° symmetrical positions, there is no place to release the left and right deviations. Therefore, when the base material 3 is a cylindrical body or other endless cylindrical body, it is very effective in preventing this deviation.
[0036]
  Furthermore, in this embodiment, as shown in FIG. 4D, a disk-shaped base 21 having a clearance above the shoulder surface at a position facing the outer peripheral base material of the upper shoulder 10 on the small diameter side. A recess is provided on the base material facing side of the pedestal, and a thrust bearing 23 in which an elastic force is urged in the vertical direction by the disc spring 22 is disposed in the recess to function as the base material pressing mechanism 20. . According to such a configuration, it is possible to prevent the softened region from being peeled from the small-diameter upper shoulder 10 to the large-diameter lower shoulder 11 and to prevent the bobbin tool from being moved by the pressing mechanism 20 even when the base material is inclined or fluctuated. This can be followed.
[0037]
  Now, at the beginning of the friction stir welding, as shown in FIGS. 5A and 5B, a hole 8 into which the bobbin tool 1 is inserted is formed. Generally, the lower shoulder 11 and the agitation shaft (pin shaft) 12 are nut-coupled, and the agitation shaft (pin shaft) 12 is inserted with the lower shoulder 11 removed, and the lower shoulder after the insertion. 11 is nut-coupled, but it is difficult to couple at a site where the operator's hand is difficult to enter on the lower side, such as a double skin panel (two-sided hollow panel).
[0038]
  Therefore, as shown in FIG. 1 (C), the diameter of the hole 8 is made slightly larger than the outer diameter of the lower shoulder 11, and a cylindrical packing material of the same type as the diameter of the hole 8 is provided on the stirring shaft 12 (pin shaft). Although it has been considered to start joining in a state where the hole 8 is closed by fitting 15, the bobbin tool 1 is inserted into the hole 8 of the base material 3 because both the filler 15 and the hole 8 are cylindrical. In this case, the base material 3 and the filler material 15 cannot be controlled to be flush with each other by being inserted deeper or shallower than the upper side of the base material. It is difficult to join. The stirring shaft (pin shaft) 12 is a reverse screw.
[0039]
  Therefore, in this embodiment, as shown in FIG. 2A, a fitting hole 8A provided with a spline groove-like rotation restricting portion 16 is formed on the inner peripheral surface, and the fitting is made on the stirring shaft (pin shaft) 12. After attaching the filler 15A of the same material as the taper (conical frustum) -like base material fitted with the hole 8A in a male-female shape and provided with a spline projection-like rotation restricting portion 17 on the outer peripheral surface, the filling is performed. By fitting the bobbin tool 1 provided with the material into the fitting hole 8A, the rotation restricting portions 16/17 are fitted to each other, and the filler 15A and the base material fitting hole 8A are formed by the tapered portion that restricts the axial direction. Always fit flush.
[0040]
  In this case, the diameter d of the lower shoulder 11₂Is the diameter d of the upper shoulder 10₁Therefore, at the beginning of the friction stir welding, the friction stirrer is performed with the hole 8A into which the bobbin tool is inserted being small and the base material 3 and the filler 15A being easily flush with each other. Joining can be started.
  In FIG. 2B, the fitting hole 8B is formed into a convex hole having a step, and the filler 15B is formed in the same convex shape as that of the step, and the surface is regulated through the step.
[0041]
  According to this embodiment, since the spline-like groove 16 and the protrusion 17 are fitted to each other to control the rotation, the filler 15B rotates together with the stirring shaft (pin shaft) 12 even at the beginning of the friction stir welding. And softened by frictional heat input and integrated with the base material 3.
[0042]
  In FIG. 2C, the top surface of the tapered fitting hole 8C is the outer diameter d of the upper shoulder 10.₁The smaller one, (D), makes the fitting hole 8D a convex hole having a step, and the top surface of the upper shoulder 10 has an outer diameter d.₁In any case, the filler is smoothly softened and integrated when the base material 3 is softened and joined by joining.
[0043]
  FIG. 3 shows the diameter d of the lower shoulder 11.₂The diameter d of the upper shoulder 10₁The top surfaces of the fillers 15E and 15F are the upper shoulder outer diameter d.₁It is larger and the flushing is regulated by the fillers 15E and 15F. In FIG. 3B, the top surface of the tapered fitting hole 8F is the upper shoulder outer diameter d.₁The larger one, (A), is a convex hole having a step in the fitting hole 8E, and the top surface thereof is the upper shoulder outer diameter d.₁The filler 15E having the spline 16 has the same diameter.
  According to this embodiment, as shown in FIG. 3C, at the beginning of the friction stir welding, the holes 8E and 8F into which the bobbin tool is inserted are formed in the diameter d of the lower shoulder 11 of the bobbin tool.₂The diameter d of the upper shoulder 10₁Since the top surfaces of the fillers 15E and 15F are expanded even if they have the same diameter as the base material 3,(The base material in which the upper base material 3A and the lower base material 3B are joined is referred to as the base material 3)The fillers 15E and 15F are easily flush with each other, and friction stir welding can be started in this state. In either case, the outer circumferences of the fillers 15E and 15F remain when the base material 3 is softened by joining, but the portion 59 may be cut and removed after joining.
[0044]
【The invention's effect】
  As described above, according to the present invention, various problems in joining using a bobbin tool can be solved, and in particular, the softened region portion of the base material sandwiched between the upper and lower shoulders, together with the shoulder, defines the softened region of the workpiece. The fear of tearing can be prevented.
  Further, according to the present invention, even when the material to be joined is rotated between two upper and lower shoulders, the groove located in front of the joining line is opened, or the base material and the groove line are displaced forward and backward or left and right. This can eliminate the fear of the occurrence of a bonding failure.
  Furthermore, according to the present invention, at the beginning of the friction stir welding, it is possible to join in a state where the hole into which the bobbin tool is inserted is small and the base material and the filler are easily flush with each other.
[Brief description of the drawings]
FIG. 1 is an explanatory diagram of the operation of the present invention, in which (A) is the present invention, and (B) and (C) are prior art correspondence diagrams.
Fig. 2 Diameter d of lower shoulder of bobbin tool₂The upper shoulder diameter d₁It is an operational view using the bobbin tool fitting hole at the beginning of the smaller friction stir welding, wherein (A) and (C) show tapered holes, and (B) and (D) show downward convex holes.
Fig. 3 Diameter d of lower shoulder of bobbin tool₂The upper shoulder diameter d₁Is the action diagram using the bobbin tool fitting hole at the beginning of friction stir welding with the same diameter as that of the filler stir welding, and (B) is a tapered hole, and (A) is a downward convex hole. Show. (C) is a top view which shows the state after joining.
4A is an overall configuration diagram showing an embodiment of the present invention of a friction stir welding apparatus using a bobbin tool, FIG. 4B is an enlarged view of the bobbin tool, and FIG. 4C is an explanation showing a softened region; FIG. 4D shows another embodiment provided with a base material pressing mechanism.
FIG. 5 shows the friction stir welding state, (A) is the prior art, (B) is the present embodiment, (C) the left column is an arrow indicating the urging force by the rotary tool on the both sides of the base material, and the right column is It is the Example provided with the rotation control part which controls a lower shoulder and an upper shoulder each independently.
FIG. 6 shows a configuration of a bobbin tool according to a conventional technique.
[Explanation of symbols]
  1 Bobbin tool
  3 Base material
  4 Softening area
  5 groove
8A-8E Mating hole
10 Upper shoulder
11 Lower shoulder
12 Stirring shaft (pin shaft)
15A-15E Filler
16/17 Rotation restriction part
20 Base material holding mechanism
72 motor
82 Inversion mechanism

Claims (6)

In a friction stir welding apparatus comprising a lower pressing member and an upper pressing member, and having a bobbin tool in which the two pressing members are connected to or opposed to each other by a fixed or variable stirring shaft (probe shaft) between the pressing portions.
The lower pressing member and the upper pressing member are made to have different diameters so that both the front and back surfaces of the base material are friction-heated, and at the position facing the base material in contact with the sliding surface in the vicinity of the outer periphery of the pressing member on the small diameter side. A friction stir welding apparatus comprising: a base material pressing mechanism; and a frictional heat input sliding portion in contact with the base material of the two pressing members having different heat capacities or different rotation speeds. . In the friction stir welding apparatus according to claim 1,
A friction stir welding apparatus characterized in that the heat capacity for receiving heat from both the front and back surfaces of the base material is made different by making the diameter or thickness of the lower pressing member different from that of the upper pressing member. Includes a lower press member and the upper pressing member, the friction stir welding apparatus having a bobbin tool the two pressing member is confronted by the pressing portion between the fixed or variable攪拌軸(probe shaft),
The lower pressing member is connected to the agitation shaft, and the upper pressing member is freely fitted to the agitation shaft, and the rotation direction of the upper pressing member is set in the opposite direction with respect to the lower pressing member. A friction stir welding apparatus characterized by the above. Includes a lower press member and the upper pressing member, the friction stir welding apparatus having a bobbin tool the two pressing member is linked or opposed by the pressing member between a fixed or variable攪拌軸(probe axis) In
And forming the same diameter or smaller diameter than the lower press member and the upper pressing member, filler fitted to the stirring shaft, the lower pressing unit in accordance with the shape of the base material bonding wire starting end fitting hole towards the upper push member side from the wood side, the friction stir welding apparatus characterized by being formed with an axial restriction portion. A bobbin tool comprising a lower pressing member and an upper pressing member, wherein the two pressing members are connected to or opposed to each other by a stirring shaft (probe shaft) fixed or variable between the pressing portions, and the bobbin tool is used as a base material while traveling along the base material bonding wire to each other is formed by abutting the rotational sliding movement and the lower press member of the upper pressing member located on its upper side across the preform joint base material bonding line In the friction stir welding method in which frictional heat is applied to the upper and lower surfaces of the base material joint from the rotational sliding contact motion of the base material and the base material joint is joined by plastic flow,
Said rotary sliding movement direction by varying the lower and upper rotation sliding movement direction, the friction stir welding method characterized in that stirring is carried out so as to face the welding line the front side in the direction of the bobbin tool progresses . Includes a lower press member and the upper pressing member, the bonding of the base material by using a bobbin tool the two pressing member is linked or opposed by the pressing portion between the fixed or variable攪拌軸(probe axis) In the friction stir welding method to be performed,
In the state where the friction stirring part start end is provided with a fitting hole provided with a rotation restricting portion and an axial restricting portion on the inner peripheral surface, and the filler that is fitted into the fitting hole is attached to the stirring shaft, A friction stir welding method, wherein the friction stir welding is started after the bobbin tool is fitted in the fitting hole.

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