JP4366257B2 - Friction stir welding equipment - Google Patents

Description

  The present invention relates to a friction stir welding apparatus for joining laminated portions formed by laminating a plurality of members.

  As a method of laminating members and joining the laminated portions, spot welding is common, but in recent years, joining by friction stir welding has been proposed. As such a friction stir welding apparatus that performs friction stir welding of a part, for example, the one described in Patent Document 1 can be cited.

  This type of friction stir welding apparatus 1 schematically shown in FIG. 5 includes a rotation operation motor (not shown) for rotating the friction stir welding tool 2 and the friction stir welding tool 2 in the vertical direction in FIG. And a displacement motor (not shown) for linearly displacing. The rotation motor is accommodated in the casing 3, and the displacement motor is accommodated in the sub casing 4. That is, in the friction stir welding apparatus 1, the friction stir welding tool 2 and the rotation operation motor are arranged on the same axis.

  When performing friction stir welding with the friction stir welding apparatus 1, the laminated portion 6 is placed on the receiving portion 5 disposed below, and the friction stir welding tool 2 that rotates is laminated under the action of the displacement motor. The probe 6 of the friction stir welding tool is finally buried in the laminated portion 6 while moving downward toward the portion 6. Along with this burying, the meat of the laminated portion 6 is agitated. In other words, the meat is plastically flowed.

Japanese Patent No. 3429475

  As described above, when the friction stir welding tool 2 and the motor for rotation operation are arranged on the same axis, the friction stir welding is easily performed if the members to be stacked are in the shape shown by the solid line L1 in FIG. can do. However, when the member has a shape as indicated by the imaginary line L2 or the imaginary line L3, the member interferes with the casing 3 or the like, so that the laminated portion 6 to be joined is below the friction stir welding tool 2. The problem that it becomes difficult to arrange | position to this arises.

  Further, when the gap remains between the stacked members, when performing friction stir welding, as shown in FIG. 6, the corner portion of the friction stir welding tool 2 is pressed and slidably contacted. The thickness of the workpiece W is reduced, and a hole is formed in some cases. For this reason, the malfunction that the intensity | strength of the upper workpiece | work W falls is caused.

  Furthermore, in this case, since the receiving part 5 on which the laminated part 6 is placed is flat, even if the probe 7 is buried from the upper end surface side of the laminated part 6 and the meat causes plastic flow, the meat is still on the lower end face. It cannot protrude from the side. That is, since the meat hardly flows even if the probe 7 is buried, the meat for which the probe 7 is buried flows out as burrs on the upper end surface side. Accordingly, a finishing process for cutting burrs is required, and the thickness of the portion where the probe 7 is buried becomes small, which causes a problem that the bonding strength of the laminated portion 6 becomes insufficient.

  The present invention has been made to solve the above-described problems, and it is possible to avoid interference with the members to be joined, and it is also possible to avoid reducing the thickness of the members. Another object of the present invention is to provide a friction stir welding apparatus capable of obtaining a laminated portion having excellent bonding strength.

In order to achieve the above object, the present invention is a friction stir welding apparatus for friction stir welding a laminated portion formed by laminating a plurality of members,
A first arm provided with a placement member for placing the laminated portion on the end;
A second arm connected to the first arm via a guide member;
A friction stir welding tool disposed at the tip of the second arm;
The second arm is rotatably and displaceable, and is rotated in a direction to approach or separate from the first arm, thereby causing the guide member to guide the second arm. A rotating member that is displaced in a direction toward or away from the first arm,
A belt member for synchronously rotating the rotating member and the friction stir welding tool;
Displacement rotating means for rotating the rotating member;
It is characterized by having.

  In the present invention, the friction stir welding tool is disposed at a position separated from the rotating means for rotating the friction stir welding tool. In other words, the friction stir welding tool and the rotating means are not arranged on the same axis. By setting it as such a structure, the dimension of the longitudinal direction of a friction stir welding apparatus becomes small. For this reason, it can avoid that a workpiece | work interferes with a friction stir welding apparatus. In other words, the types of workpieces that can be subjected to friction stir welding increase.

  In this case, since the rotating means rotates the friction stir welding tool via the belt member, the friction stir welding tool separated from the rotating means can be easily rotated.

  According to the present invention, since the friction stir welding tool is disposed at a position separated from the tool rotating operation means, the workpiece and the friction stir welding apparatus interfere with each other regardless of the shape of the stacked workpieces. It can be avoided.

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

A schematic overall longitudinal sectional view of the friction stir welding apparatus according to the present embodiment is shown in FIG. The friction stir welding apparatus 10 includes a first arm 12 that is positioned and fixed by being connected to a tip of an arm of an articulated robot (not shown), and a second arm 14 that approaches or separates from the first arm 12. The guide bars 16a and 16b that connect the first arm 12 and the second arm 14, the friction stir welding tool 18 disposed at the tip of the second arm 14, and the second arm 14 are connected to the first arm. having a rod 20 for closer or away from the 12, and a displacement rotary motor 24 for causing rotation operation together when displacing the friction stir welding tool 18 the rod 20 by rotation.

  The first arm 12 has a long portion 28 whose width gradually increases toward the right in FIG. 1 and an elbow portion 30 having a substantially trapezoidal cross section, and of these, the long portion 28 in FIG. As shown in FIG. 2, a placement member 34 for placing a laminated portion 32 formed by laminating the first workpiece W1 and the second workpiece W2 is positioned and fixed at the left end portion. In addition, a hollow cylindrical body-shaped concave portion 36 is provided in a substantially central portion of the upper end surface of the mounting member 34.

  On the other hand, the elbow part 30 is provided with through holes 38a and 38b, and the small diameter parts 40a and 40b of the guide bars 16a and 16b are passed through the through holes 38a and 38b. Moreover, the lower end surface of the elbow part 30 is provided with recesses 42a and 42b communicating with the through holes 38a and 38b, and the bolts 44a and 44b inserted into the recesses 42a and 42b are provided on the small diameter parts 40a and 40b. Screwed into the tip. That is, the small diameter portions 40a and 40b are blocked by the heads of the bolts 44a and 44b, thereby preventing the small diameter portions 40a and 40b from coming off from the through holes 38a and 38b.

  As shown in FIG. 2, the friction stir welding tool 18 installed on the end surface facing the first arm 12 at the left end of the second arm 14 is provided on the rotating body 48 and the tip of the rotating body 48. And a probe 52 having a threaded portion 50, and the rotary body 48 is connected to the rod 20. As the probe 52, a probe whose diameter is smaller than the opening diameter of the recess 36 is selected.

  Around the friction stir welding tool 18, a pressing member 56 that presses the laminated portion 32 at its lower end surface is disposed. In other words, the friction stir welding tool 18 is surrounded by the pressing member 56. Of course, a through hole 58 is provided in the lower end surface of the pressing member 56, and the probe 52 of the friction stir welding tool 18 protrudes from the through hole 58.

  The diameter of the tip portion of the pressing member 56 is set so that the curved portion R and the bent portion provided on the second work W2 on the upper side are flattened by pressing the stacked portion 32 over a wider range than necessary. It is set smaller than the abdomen. That is, the pressing member 56 is provided with a small diameter portion 60 and a large diameter portion 62.

  An annular stepped portion 64 is provided at the upper end portion of the large-diameter portion 62 by bending the upper end portion toward the outer diameter direction. The annular step portion 64 is blocked by an annular blocking portion 70 provided at the lower end portion of the spring cover 68 that accommodates the coil spring 66, thereby preventing the pressing member 56 from coming off from the spring cover 68. Yes.

  The rotating body 48 is accommodated in the rotating body cover 72. The upper end portion of the rotating body cover 72 is provided with an annular coupling allowance 74 that is bent toward the horizontal direction from the longitudinal direction (vertical direction) of the rotating body cover 72. These are connected and fixed to the side peripheral wall of the spring cover 68 by bolts (not shown).

  A bearing 76 is interposed between the rotating body cover 72 and the upper part of the rotating body 48, and the presence of the bearing 76 prevents the rotating body cover 72 and the spring cover 68 from rotating. . In FIG. 2, reference numeral 78 denotes a bush.

  The lower end portion of the coil spring 66 is seated on the upper end surface of the annular step portion 64 of the pressing member 56, while the upper end portion is seated on the lower end surface of the annular coupling allowance 74 of the rotating body cover 72. Accordingly, the pressing member 56 is elastically biased toward the first arm 12 side by the coil spring 66. As described above, the annular stepped portion 64 of the pressing member 56 is blocked by the annular blocking portion 70 of the spring cover 68, so that the pressing member 56 is prevented from coming off from the spring cover 68.

  The upper portion of the rotating body 48 is connected to a rotating shaft 80 having a diameter larger than that of the rotating body 48. A small pulley 84 around which a timing belt 82 is wound is fitted on the side peripheral wall of the rotating shaft 80.

  The rotating shaft 80 is inserted into a through hole 86 provided at the left end portion of the second arm 14. A bearing 88 is interposed between the rotating shaft 80 and the second arm 14, and therefore, the rotating operation of the rotating shaft 80 is not hindered by the second arm 14.

  In the second arm 14, through holes 90 a and 90 b are provided in portions corresponding to the through holes 38 a and 38 b of the elbow part 30 of the first arm 12. The through holes 90 a and 90 b include a bush 92 and a bearing. The guide bars 16 a and 16 b are passed through 94.

  Further, a through hole 96 is further provided between the through holes 90 a and 90 b, and the rod 20 is passed through the through hole 96 through a bearing 98. A large pulley 104 is connected to the distal end surface of the rod 20 protruding from the through hole 96 via a bolt 100. The timing belt 82 is wound around the large pulley 104.

  Here, large-diameter portions 106 and 108 are formed so as to project from both the distal end portion and the substantially mid-abdominal portion of the rod 20, and both the through-holes 96 in the second arm 14 are formed by the large-diameter portions 106 and 108. A part near the opening is sandwiched.

  A casing 110 is connected above the right end of the second arm 14 via the guide bars 16a and 16b. That is, the casing 110 has a large-diameter portion 112 whose upper portion is reduced in a tapered shape, and the guide bars 16 a and 16 b are inserted into through holes 114 a and 114 b provided in the large-diameter portion 112. The tapered surface of the large diameter portion 112 is provided with recesses 116a and 116b, and bolts 118a and 118b inserted into the recesses 116a and 116b are screwed into the heads of the guide bars 16a and 16b.

  The guide bars 16a and 16b are fitted with washers 120a and 120b having a diameter larger than that of the through holes 114a and 114b. The washers 120a and 120b block the casing 110 so that the casing 110 Is positioned.

  A linear rotary bush 122 and a bearing 124 are interposed between the casing 110 and the upper end of the rod 20. Among these, the upper end surface of the linear rotary bushing 122 is connected to the displacement rotary motor 24. Accordingly, the linear rotary bushing 122 is driven by the rod 20 and by extension as the displacement rotary motor 24 is urged to rotate. It rotates with the large pulley 104.

  The rod 20, which is a hollow cylindrical body, moves down and as the screw nut 130 rotates inside the casing 110. That is, a screw portion 132 of a screw nut 130 is passed through the screw 131, and a connection allowance 134 of the screw nut 130 is connected to the upper end portion of the rod 20. Therefore, the screw nut 130 rotates and moves down and up while being guided by the screw 131, so that the rod 20 connected to the connecting margin 134 of the screw nut 130 moves down and up.

  The upper end portion of the screw 131 is connected and fixed to the casing 114, and therefore the screw 131 does not rotate.

  The friction stir welding apparatus 10 according to the present embodiment is basically configured as described above. Next, the function and effect will be described.

  The articulated robot moves the friction stir welding apparatus 10 to the laminated portion 32 in which the first workpiece W1 and the second workpiece W2 are laminated, and the laminated portion 32 is moved between the mounting member 34 and the friction stir welding tool 18. It arrange | positions between the probes 52. At this time, since the friction stir welding tool 18 is disposed away from the displacement rotation motor 24, the workpiece is frictionally applied even when a workpiece having a shape shown by a virtual line in FIG. 3 is joined. There is no interference with the stir welding apparatus 10. Thus, by disposing the friction stir welding tool 18 away from the axis of the displacement rotation motor 24, the degree of freedom of the shape of the workpiece to be friction stir welded increases. In other words, the friction stir welding can be performed regardless of the shape of the workpiece.

  In this case, as the first workpiece W1 and the second workpiece W2, those made of so-called 5000 series aluminum whose JIS symbol number is in the 5000 range are selected.

  Next, the displacement rotation motor 24 is urged to rotate, whereby the screw nut 130 rotates. With this rotation operation, the screw nut 130 is lowered, and as a result, the rod 20 connected to the screw nut 130 is lowered. Following this, the second arm 14 held between both large diameter portions of the rod 20 moves downward while being guided by the guide bars 16a and 16b, so that the second arm 14 is directed to the first arm 12. Approach. Finally, as shown in FIGS. 2 and 3, the stacked portion 32 is sandwiched between the mounting member 34 and the pressing member 56, and covers the recess 36 of the mounting member 34 at this time.

  When the lowering operation of the rod 20 is further continued, the pressing member 56 is pressed by the stacked portion 32. As a result, the coil spring 66 (see FIG. 2) is contracted and the pressing member 56 moves upward. As a result, the probe 52 of the friction stir welding tool 18 reaches the through hole of the pressing member 56.

  On the other hand, when the displacement rotation motor 24 is urged to rotate, the large pulley 104 rotates following the rotation of the linear rotary bush 122 connected to the displacement rotation motor 24. The small pulley 84 (see FIG. 2), the rotary shaft 80, and the friction stir welding tool 18 rotate through the timing belt 82 wound around the large pulley 104.

  When the probe 52 of the friction stir welding tool 18 that rotates is brought into sliding contact with the upper end surface of the laminated portion 32, frictional heat is generated in the laminated portion 32. For this reason, the contact part of the probe 52 in the laminated part 32 and its vicinity soften, and the probe 52 is buried in the laminated part 32 as shown in FIGS. As a result, the meat of the laminated portion 32 flows into the recess 36. As described above, since the diameter of the horizontal section of the recess 36 is larger than the diameter of the probe 52, this inflow easily proceeds.

  The softened layered portion 32 is agitated (plastically flowed) by the probe 52. At this time, as described above, in the stacked portion 32, the meat in which the probe 52 is buried flows plastically into the recess 36, so that the meat does not rise from the buried portion of the probe 52. Therefore, no burr is formed. Thus, by providing the mounting member 34 with the recess 36, the laminated portion 32 can be friction stir welded without forming burrs. For this reason, since the thickness of the laminated portion 32 is not reduced, the bonding strength of the laminated portion 32 is increased.

  In addition, in this case, as shown in FIG. 4, since the laminated portion 32 is pressed over a wide range by the lower end surface of the pressing member 56, the gap between the first workpiece W1 and the second workpiece W2 is crushed. That is, since no gap is formed between the first workpiece W1 and the second workpiece W2, the corner portion of the rotating body 48 of the friction stir welding tool 18 that rotates is difficult to slidably contact the upper second workpiece W2. Thereby, it can avoid that a hole is formed in the 2nd workpiece | work W2.

  In this way, the friction stir welding is performed, and at the same time, as the probe 52 is buried, the protrusion 142 is formed on the surface of the second workpiece W2 facing the first workpiece W1, and the second workpiece W1 is second. A depression 140 is formed on the surface facing the workpiece W <b> 2, and the protrusion 142 is fitted in the depression 140. In addition, the lower end part of the depression part 140 is a non-stirring part (plastic deformation part) in which the plastic flow of meat is not performed. That is, the protruding portion 142 is fitted into the depressed portion 140 formed into a shape corresponding to the concave portion 36 by plastic deformation, thereby providing a so-called caulking state. Thus, the joining strength of the laminated portion 32 is also improved by forming a caulking state between the first workpiece W1 and the second workpiece W2.

  After the agitation is started and the probe 52 is buried, the displacement rotation motor 24 is deenergized to stop the rotation of the probe 52, thereby stopping the plastic flow of the meat. Next, the displacement rotation motor 24 is urged to rotate in the direction opposite to the above, and the screw nut 130 is rotated in the reverse direction. As a result, the screw nut 130, and consequently the rod 20, moves upward while being guided by the guide bars 16a, 16b. As a result, the second arm 14 held between the large-diameter portions 106, 108 of the rod 20 moves upward, Finally, the second arm 14 is displaced in a direction away from the first arm 12. Further, the pressing member 56 separated from the laminated portion 32 is elastically biased toward the first arm 12 by the coil spring 66 and returns to the original position.

  During this time, the meat of the laminated portion 32 is cooled and solidified, and the first workpiece W1 and the second workpiece W2 are integrally solid-phase bonded. On the side of the first workpiece W1 in the laminated portion 32 joined in this way, there is a cylindrical convex portion that is formed to protrude as the meat flowing into the concave portion 36 cools and solidifies. That is, in this case, the outer diameter of the convex portion is substantially the same as the diameter of the concave portion 36.

  In the above-described embodiment, the case where two workpieces are friction stir welded is described as an example. However, the number of workpieces to be stacked is not limited to two, but three or more workpieces. You may make it laminate | stack.

  Further, it is not particularly necessary to fill the entire space of the concave portion 36 with the meat of the laminated portion 32.

1 is a schematic overall longitudinal sectional view of a friction stir welding apparatus according to the present embodiment. It is a principal part expansion schematic longitudinal cross-sectional view of the friction stir welding apparatus of FIG. It is a schematic whole longitudinal cross-sectional view which shows the state by which the friction stir welding apparatus of FIG. 1 was closed and the laminated part was clamped. It is a principal part expansion schematic longitudinal cross-sectional view which shows the state by which the tool for friction stir welding rotates and a laminated part is friction stir welded. It is a schematic whole side view of the friction stir welding apparatus which concerns on a prior art. It is a principal part expansion schematic plan view of the friction stir welding apparatus of FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Friction stir welding apparatus 12, 14 ... Arm 16 ... Guide bar 18 ... Friction stir welding tool 20 ... Rod 24 ... Displacement rotation motor 32 ... Lamination | stacking part 34 ... Mounting member 36 ... Recessed part 52 ... Probe 56 ... Pressing member 66 ... Coil spring 82 ... Timing belt 84, 104 ... Pulley 106, 108 ... Large diameter part 110 ... Casing 122 ... Linear rotary bush 130 ... Screw nut 131 ... Screw W1, W2 ... Workpiece

Claims (1)

A friction stir welding apparatus for friction stir welding a laminated portion formed by laminating a plurality of members,
A first arm provided with a placement member for placing the laminated portion on the end;
A second arm connected to the first arm via a guide member;
A friction stir welding tool disposed at the tip of the second arm;
The second arm is rotatably and displaceable, and is rotated in a direction to approach or separate from the first arm, thereby causing the guide member to guide the second arm. A rotating member that is displaced in a direction toward or away from the first arm,
A belt member for synchronously rotating the rotating member and the friction stir welding tool;
Displacement rotating means for rotating the rotating member;
A friction stir welding apparatus comprising:

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