JP2008055430A - Friction point welding device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a friction point welding device where the bottom walls of recessed parts are welded at high quality while suppressing deformation caused by stress upon welding with a simple constitution. <P>SOLUTION: The friction point welding device comprises: a receiving fixture 71 receiving a second metal member W2 and positioning the same; a pressing fixture 72 moving between a pressing position A for pressing a space in the adjoining welding position P of the bottom wall 67a of the recessed part in a first metal member W1 from the upper part and a retreating position B for retreating from the welding position P; a moving mechanism 73 for moving the pressing fixture 72 between the pressing position A and the retreating position B; and a driving means for pressing the first metal member W1 from the upper part while rotating a rotary tool 16. The first metal member W1 and the second metal member W2 both having the recessed parts are superimposed in such a manner that the recessed parts are superimposed, and a part of the bottom wall 67a of the recessed part in the first metal member W1 is softened by frictional heat by the rotation and pressing of the rotary tool 16, so as to be plastically fluidized. Thus, the first and second metal members W1, W2 are spot-welded at a plurality of parts. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a friction spot welding apparatus that spot welds a plurality of metal members at a plurality of locations.

  2. Description of the Related Art In recent years, aluminum alloy materials and the like have been widely used in automobile bodies and the like for the purpose of reducing weight. Along with this, for example, there are increasing opportunities to join members made of an aluminum alloy material, or to join a member made of an aluminum alloy material and a member made of iron, steel material, or the like.

  A friction point welding apparatus is known as one that performs such joining. With this friction point joining device, a plurality of metal members are overlapped, pressed while rotating the rotary tool, softened by the frictional heat, and plastic flow is generated to spot-join the metal members. At this time, the metal members to be bonded are subjected to solid phase bonding (bonding in a solid state without melting) at a temperature equal to or lower than the melting point.

For example, Patent Document 1 discloses a spot welding apparatus using friction stir welding, in which an annular pressing unit that presses around a joint point around a rotary tool during joining is disclosed.
Japanese Patent Laid-Open No. 2002-120076

  However, in the above conventional friction point joining device, when the pressing means is installed, the size of the periphery of the rotary tool is increased, and when there are concave portions or convex portions in the shape near the joining position, depending on the shape of the concave portion or convex portion. Is difficult to be surely pressed by the pressing means, and there is a problem that the joining position is restricted.

  This invention is made | formed in view of this point, The place made into the objective is to join a recessed part bottom wall by high quality, suppressing the deformation | transformation by the stress at the time of joining.

  In order to achieve the above object, according to the present invention, the adjacent joining positions of the concave bottom wall of the first metal member are pressed by a pressing jig.

  Specifically, in the first invention, the first metal member and the second metal member both having a recess are overlapped so that the recess overlaps, and the bottom wall of the recess of the first metal member is rotated and pressed by the rotary tool. A friction point welding apparatus that performs spot welding of a first metal member and a second metal member at a plurality of locations by softening a part of the metal member with frictional heat and plastically flowing it.

And the said friction point joining apparatus is the receiving jig which receives and positions the 2nd metal member side of the above-mentioned 1st and 2nd metal member piled up, and
A pressing jig that moves from above to a pressing position that presses between adjacent bonding positions of the concave bottom wall of the first metal member, and a retreat position that retreats from the bonding position;
A moving mechanism for moving the pressing jig to the pressing position and the retracted position;
Drive means for pressing from the upper side to the first metal member side while rotating the rotary tool while pressing between the adjacent joining positions with the pressing jig.

  According to the above configuration, the first and second metal members are overlapped so that the concave portions are overlapped, and the pressure between the adjacent joining positions on the bottom wall of the concave portion of the first metal member is pressed from above by the pressing jig. While the tool is pressed against the first metal member side, the rotating tool is accessed to the joining position, and after joining one joining position, joining at another joining position is performed across the pressed location by the pressing jig. For this reason, even if it is a case where the circumference of a rotary tool does not enlarge and a recessed part exists in the shape of the joining position vicinity, since the 1st metal member side is reliably pressed by the pressing jig, it receives the restriction | limiting of a joining position. There is nothing. At this time, since the outer periphery of the joining position is kept rigid by the corner portion between the bottom wall and the side wall of the recess, even if the gap between adjacent joining positions is simply pressed from above with a pressing jig, Stress deformation is suppressed.

  In the second invention, the pressing jig includes a pressing portion disposed in the center, and a plurality of rotating tool insertion holes that are disposed so as to straddle the pressing portion and allow the tip of the rotating tool to be inserted therethrough. Yes.

  According to the above configuration, the first metal member is softened by frictional heat at the tip of the rotary tool that has passed through one of the rotary tool insertion holes from above in a state where the bottom wall of the recess is pressed by the pressing portion at the center of the pressing jig. After the first metal member and the second metal member are spot-bonded by plastic flow, bonding at another bonding position is performed at the tip of the rotary tool that has passed through the other rotary tool insertion hole across the pressing portion.

  In a third aspect of the invention, the moving mechanism includes a rotating arm that supports the pressing jig and rotates between a pressing position and a retracted position, and a drive cylinder that rotates the rotating arm.

  According to the above configuration, since the rotating arm that rotates the pressing jig between the pressing position and the retracted position is driven by the driving cylinder, the rotating tool is compared with the conventional lifting type driving method. Does not take up space around. For this reason, interference at the time of joining of the rotary tool is avoided, and the setting of the first and second metal members to the receiving jig is easy.

According to a fourth aspect of the present invention, the apparatus includes a joining gun on which the rotating tool, a receiving tool disposed to face the rotating tool, and the driving unit are mounted.
The receiving jig is fixed to the base member that supports the receiving jig, the joining gun is moved to the joining position, the receiving tool is brought into contact with the back side of the receiving jig or the base member, and the rotating tool is rotated. And moving means for pressing the first metal member side and spot joining the first and second metal members at each joining position.

  According to the above configuration, it is only necessary to insert the receiving tool of the joining gun into the space below the base member and contact the receiving jig or the back side of the base member at the time of joining, so there is no need to increase the space below the base member. . For this reason, since the support rigidity of a receiving jig can be made high, joining quality is stabilized.

In a fifth invention, the first metal member is an aluminum alloy plate,
The second metal member is a steel plate,
The first and second metal members are configured to be spot-bonded in a solid phase state.

  According to said structure, the oxide film currently formed in the surface of the 2nd metal member by the oxygen in the air is destroyed in a joining position, The new surface of a 2nd metal member is exposed, 1st metal member W1 and Since the mating surface portions of the second metal member are solid-phase bonded by friction point bonding, the bonding strength is stably increased.

  In the sixth invention, the surface of the second metal member is plated.

  According to the above configuration, during the joining, the plating material on the surface of the second metal member is melted by the frictional heat and mixed with the first metal member due to frictional heat, and the plating layer is peeled off to remove the first metal member and the second metal member. The metal member is securely crimped.

  According to 7th invention, the receiving jig is comprised so that the whole recessed part bottom wall of the said 2nd metal member may be supported.

  According to the above configuration, since the receiving jig supports the entire bottom wall of the concave portion of the second metal member, the plating on the surface of the second metal member can be performed compared to a case where only a part of the bottom surface of the concave portion is supported. It does not peel off and adhere to the receiving jig. For this reason, corrosion on the surface of the second metal member is avoided and unevenness due to plating adhesion is not formed on the surface of the receiving jig, so that the first and second metal members are reliably supported by the receiving jig.

  As described above, according to the present invention, the stress at the time of joining can be achieved with a simple configuration by reliably pressing between the joining positions of the concave bottom walls of the first metal member with the pressing jig. It is possible to join the bottom wall of the recess with high quality while suppressing deformation due to.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

-Configuration of friction spot welding device-
FIG. 1 is a schematic configuration diagram of a friction point welding apparatus 1. The friction point welding apparatus 1 includes, as main components, a joining gun 10 and a robot 40 as a moving unit that includes the joining gun 10 on a wrist. As this robot 40, for example, a general-purpose 6-axis vertical articulated robot is preferably used.

  The robot 40 is connected to the control panel 50 via a harness 51. The joining gun 10 is connected to the control panel 50 via harnesses 52, 54, 55 and a repeater 53. A control unit 50 a is built in the control panel 50. The control unit 50a controls the robot 40 to operate the bonding gun 10 so that a predetermined position and inclination are set in advance. Further, the control unit 50 a controls a pressing motor 14 and a rotating motor 15 (see FIG. 2), which will be described later, mounted on the joining gun 10, so that the joining tool 18 including the rotating tool 16 and the receiving tool 17 is provided. , And a predetermined operation set in advance.

  As shown in FIG. 2, the joining gun 10 includes a mounting box 11 for the robot 40, an L-shaped arm 12 extending downward from the lower surface of the mounting box 11, and a side surface of the mounting box 11 above the arm 12. A pressing motor 14 connected to the harness 54, and a rotating motor 15 connected to the harness 55.

  A rotating tool 16 that is one of the joining tools 18 is provided at the lower end of the main body case 13. On the other hand, a receiving tool 17 that is the other of the welding tool 18 is provided at the tip of the arm 12 so as to face the rotating tool 16 and the rotation axis X direction of the rotating tool 16.

  Although not shown in detail, a screw shaft and a spline shaft that extend in the vertical direction in parallel with each other are provided in the main body case 13 so as to be rotatable around respective axis centers. The screw shaft is rotationally driven by the rotation of the pressing motor 14, and the spline shaft is rotationally driven by the rotation of the rotational motor 15. An elevating cylinder is integrally coupled to the block screwed to the screw shaft, and a rotating cylinder is splined to the spline shaft (both not shown). The rotating cylinder is rotatably provided inside the elevating cylinder. The spline shaft, the lifting cylinder and the rotating cylinder are arranged concentrically with each other.

  A cylindrical downward projecting portion 13 a is formed on the lower surface of the main body case 13. Lower ends of the elevating cylinder and the rotating cylinder protrude downward. The rotating cylinder on the inside protrudes downward longer than the lifting cylinder on the outside, and the attachment member 36 is fixed to the lower end of the rotating cylinder. A base end portion, which is an end portion on the opposite side of the distal end portion of the rotary tool 16, is attached to the attachment member 36 in a detachable (replaceable) manner. The rotation axis X of the attached rotary tool 16 is on an extension line of the axis of the spline shaft. Note that a space between the lower cover 23 and the lower end of the elevating cylinder is covered with an elastic bellows member 34 that protects the outer surface of the elevating cylinder from contamination outside the main body case 13.

  The pressing motor 14 and the rotating motor 15 constitute driving means that presses the work W while rotating the rotary tool 16.

  FIG. 3 is an enlarged view of the tip of the rotary tool 16. The tip of the rotary tool 16 is positioned on the shoulder 16b facing the workpiece W, which is the lower end surface of the cylindrical body 16a (the outline is circular), and the rotation axis X of the rotary tool 16. And a pin portion 16c that is smaller than the outer diameter of the shoulder portion 16b and protrudes by a predetermined length h from the shoulder portion 16b to the side facing the workpiece W, and a shoulder portion 16b around the pin portion 16c. And an annular recess 16d. In the present embodiment, the bottom surface of the annular recess 16d is inclined so that the dent amount decreases toward the radially outer side. The annular recess 16 d is recessed in a conical shape with the rotation axis X of the rotary tool 16 as the center. As specific dimensions of the rotary tool 16, for example, the diameter D1 of the shoulder portion 16b is 10 mm, the diameter D2 of the pin portion 16c is 2 mm, the protruding length h of the pin portion 16c is 0.3 mm to 0.35 mm, and the annular recess 16d. The inclination angle θ of the bottom surface with respect to the shoulder portion 16b is 5 ° to 7 °.

  However, the optimum shape of the rotary tool 16 is not uniquely determined, and varies depending on the application such as the material and thickness of the workpiece W, the number of workpieces W to be overlaid, and the like. Therefore, it is desirable to prepare a plurality of types of rotary tools 16 suitable for each application, and use them by appropriately replacing them according to the application. The shape of the rotary tool 16 having the annular recess 16d as shown in FIG. 3 is suitable particularly when joining different kinds of metal members having different melting points.

  As shown in FIGS. 4 to 6, generally, the friction point joining is performed by joining a workpiece W composed of a plurality of metal members (in the case of two pieces, a first metal member W1 and a second metal member W2). That is, the friction point joining is performed so as to sandwich the workpiece W overlapped by the rotary tool 16 and the receiving member 17. In the present embodiment, as shown in FIG. 6, the friction point joining apparatus 1 overlaps the first metal member W1 and the second metal member W2 both having the recesses 67 and 68 so that the recesses 67 and 68 overlap each other. It is designed to be held in a state. Then, by rotation and pressing of the rotary tool 16, a part of the bottom wall 67a of the concave portion 67 of the first metal member W1 is softened by frictional heat and plastically flowed, and the first and second metal members W1, W2 are moved at a plurality of locations. It is comprised so that spot joining may be carried out.

  Here, the workpiece | work W of this embodiment is demonstrated. FIG. 8 shows a usage state of the structural member of the automobile body as the workpiece W. The components of the automobile body include a reinforcement (first metal member W1) of the trunk lid 60 of the automobile and a bolt retainer (second metal member) for attaching a hinge 70 (shown in FIG. 9) to the trunk lid 60. W2). These members W1 and W2 are arranged in a pair of left and right inside the corner of a bag-structured trunk lid 60 in which the outer panel 61 and the inner panel 62 are joined by hemming at the peripheral edge. For example, the first metal member W1 is made of a 6000 series aluminum alloy (thickness 1.4 mm), and the second metal member W2 is made of a galvanized steel plate (thickness 1.0 mm). . The material of the first metal member W1 and the second metal member W2 may be the same or different.

  As shown in FIG. 9, the first metal member W <b> 1 is fixed to the inner panel 62 by appropriate means inside the corner of the trunk lid 60. Then, the second metal member W2 is overlapped on the first metal member W1 and is subjected to friction point bonding (the bonding position P is two places). The threaded portion of the bolt 65 coupled to the second metal member W2 by welding or the like protrudes outward from the inner panel 62, and the hinge 70 is tightened and fixed to the threaded portion of the bolt 65 with the nut 66 through the hinge 70. Here, the friction point joining between the first metal member W1 and the second metal member W2 is for temporarily fixing the second metal member W2 to the trunk lid 60 until the hinge 70 is assembled to the trunk lid 60. is there.

  In that case, the joining position P is provided on the bottom walls 67a and 68a of the recesses 67 and 68 formed in the first metal member W1 and the second metal member W2. These recesses 67 and 68 are provided to secure the rigidity of the first metal member W1 or to make a relief part of the burr R (see FIG. 14) generated by the friction point joining, and are clearly shown in FIG. As you can see, it is finished in a circular shape when viewed from the front.

  As shown in FIG. 4, the friction point joining apparatus 1 includes a receiving jig 71 that receives and positions the superimposed first and second metal members W1 and W2 on the second metal member W2 side. Specifically, the receiving jig 71 is formed in a block shape larger than the bottom surface of the bottom wall 68a so as to support the entire bottom wall 68a of the recess 68 of the second metal member W2.

  The friction point joining apparatus 1 moves to a pressing position A that presses between adjacent joining positions P of the bottom wall 67a of the concave portion 67 of the first metal member W1 and a retreat position B that retreats from the joining position P. A pressing jig 72 is provided.

  FIG. 7 is a perspective view of the pressing jig 72 as viewed obliquely from below. The pressing jig 72 has a three-stage structure including an uppermost base 72a, an interrupted middle stage 72b, and a lowermost pressing part 72c.

  The base 72a is flat and has bolt holes 72e at the four corners. The pressing jig 72 is fixed to the tip of a rotating arm 78 described later by a bolt (not shown) inserted through the bolt hole 72e.

  The middle step portion 72b has a disk shape in which an inner portion protrudes from the bolt hole 72e of the base portion 72a. And the hole 72d which penetrates the base 72a and the middle step part 72b is provided. The cross-sectional shape of the hole 72d is an oval shape that includes two joint positions P in plan view.

  The pressing portion 72c is a wall-shaped member that protrudes from the middle step portion 72b. The tip portion directly presses the portion between the joining positions P on the bottom wall 67a of the reinforcement (first metal member W1) to prevent the lifting at the time of friction point joining. The pressing portion 72c is provided so as to pass the straight portions of the oval hole portion 72d. Thus, the pressing portion 72c is provided so as to straddle the pair of rotary tool insertion holes 72f through which the tip of the rotary tool 16 is inserted, and rotates even when the rotary tool 16 is in a position corresponding to any joining position P. The tool 16 is not contacted (a state in which the rotary tool 16 is at a position corresponding to one joining position P is indicated by a two-dot chain line).

  With the above structure, the pressing jig 72 can favorably support a narrow portion between the two joining positions P without affecting the operation of the rotary tool 16 at the joining position P.

  Further, when the rotary tool 16 descends at the joining position P, it passes through the hole 72d of the pressing jig 72 and passes through the rotary tool insertion hole 72f so as not to interfere with the pressing part 72c. It is configured.

  As shown in FIG. 4, the friction point joining apparatus 1 includes a moving mechanism 73 that moves the pressing jig 72 to the pressing position A and the retracted position B. The moving mechanism 73 is attached to a workbench 76 having four leg portions 74 and a rectangular plate-like base member 75 supported by the leg portions 74. That is, on the side surface of the work bench 76, a trapezoidal movement mechanism attachment portion 76a is formed. A swing arm 78 that supports the pressing jig 72 and rotates between the pressing position A and the retracted position B and a drive cylinder 79 that rotates the rotating arm 78 swing on the moving mechanism attaching portion 76a. It is attached as possible. That is, the rotation arm 78 has a support portion 78a protruding vertically at an intermediate portion, and the tip of the support portion 78a is rotatably attached to the moving mechanism attachment portion 76a. A tip end of a cylinder rod 79a of the drive cylinder 79 is rotatably connected to the rear end side of the rotation arm 78. The upper corner of the tip of the cylinder body 79b of the drive cylinder 79 is rotatably attached to the moving mechanism attachment portion 76a. Because of such a configuration, it is possible to avoid the space around the rotary tool 16 and avoid interference when the rotary tool 16 is joined, as compared with the conventional lifting drive system, and the first and second metal members W1. , W2 can be easily set on the receiving jig 71.

  The work table 76 is placed on a turntable 77. If the work table 76 comes to be directly under the robot 40 by rotating the turntable 77, it is not necessary to move the workpiece W by the robot 40.

  The receiving jig 71 is fixed to the upper surface of the flat base member 75. The robot 40 moves the joining gun 10 to the joining position P, brings the receiving member 17 into contact with the back side of the base member 75, presses the first metal member W1 while rotating the rotary tool 16, and The second metal members W1 and W2 are configured to be spot-bonded at each bonding position P.

-Operation of the friction spot welding device-
Next, the operation | movement at the time of the friction point joining of the friction point joining apparatus 1 is demonstrated.

  As shown in FIG. 5, first, the work W in a state where the concave portions 67 and 68 are overlapped with each other on the base member 75 of the work table 76 is manually positioned and positioned. That is, the workpiece W is positioned according to the reference pin 75a provided on the surface of the base member 75 and the convex portion 75b for preventing assembly errors. Then, as shown in FIG. 6, the head portion of the bolt 65 coupled to the second metal member W <b> 2 is housed and positioned in a bolt housing portion 71 a provided in the receiving jig 71. Thus, since the receiving jig 71 supports the entire bottom wall 67a of the recess 67, the surface of the second metal member W2 is plated compared to a case where only a part of the bottom wall 67a of the recess 67 is supported. Is peeled off and hardly adheres to the receiving jig 71. For this reason, corrosion on the surface of the second metal member W2 is avoided and unevenness due to the adhesion of plating is not formed on the surface of the receiving jig 71, so that the first and second metal members W1, W2 are surely received by the receiving jig 71. Supported by

  Next, as shown in FIG. 4, the cylinder rod 79 a of the drive cylinder 79 is extended to rotate the rotating arm 78 at the retracted position B to the pressing position A, and the first portion is pressed by the pressing portion 72 c of the pressing jig 72. The space between adjacent joint positions P of the bottom wall 67a of the recess 67 of the metal member W1 is pressed from above. This support prevents the portion between the joining positions P from being lifted away from the surface of the receiving jig 71 when the friction spot joining is performed.

  Next, the work table placed on the work table 76 is moved to the position of the robot 40 by rotating the turntable 77.

  Next, the operation | movement at the time of the friction point joining in the joining position P is demonstrated. In performing the friction spot joining at the joining position P, as shown in FIG. 10, first, the operation of the robot 40 brings the joining gun 10 close to the joining position P, and the rotary tool 16 is on the first metal member W1 side of the joining position P. The receiving member 17 is positioned on the back surface side of the base member 75 directly below the receiving jig 71.

  Next, the entire bonding gun 10 is moved to the back side of the base member 75. That is, the receiver 17 is brought close to the back surface of the base member 75. The stopper 17 is stopped at a position where the tip 17a of the receiving member 17 is in contact with the back surface of the base member 75. As described above, since the receiving tool 17 of the joining gun 10 is brought into contact with the back surface side of the base member 75 at the time of joining, it is only necessary to insert the receiving tool 17 into the space below the base member 75. It is not necessary to increase the size, and the support rigidity of the receiving jig 71 can be increased. For this reason, joining quality is stabilized.

  Next, in this state, the pressing motor 14 and the rotating motor 15 are used to approach the first metal member W1 while rotating the rotary tool 16, and are pressed and friction point joined as shown in FIG. . Specifically, the friction point joining process is set to sequentially perform an initial movement process, a first pressing process, a second pressing process, and a third pressing process. Hereinafter, these steps will be described in detail.

  First, in the initial movement step, the rotary tool 16 is lowered and moved to an initial position that is a proximity position of the first metal member W1. This initial position is a position where the tip of the pin portion 16c of the rotary tool 16 is slightly separated from the first metal member W1. In this initial movement process, the rotary tool 16 may be rotated or may not be rotated, but in the present embodiment, in order to be able to immediately shift to the next first pressing process, It is made to rotate at the same rotational speed (1st rotational speed).

  In the subsequent first pressing step, as shown in FIG. 11, the rotating tool 16 is rotated at the first rotation speed, and the pressing motor 14 causes the first higher resistance than the moving resistance value of the rotating tool 16 in the initial moving step. The shoulder portion 16b and the pin portion 16c of the rotary tool 16 are pressed and contacted with the first metal member W1 for the first predetermined time by the applied pressure. The right half of the figure shows a case where a gap S is provided between the first metal member W1 and the second metal member W2, and the left half shows a case where the gap S is not provided and the two are brought into close contact with each other.

  In the first pressurizing force, the first rotation speed, and the first predetermined time, the rotary tool 16 has a part of the bottom surface of the annular recess 16d (the portion on the side of the rotation axis X having a deep depth) with respect to the first metal member W1. It sets so that it may be pushed to such an extent that the peripheral part of the shoulder part 16b and the pin part 16c may contact the 1st metal member W1, without contacting the 1st metal member W1.

  In the first pressing step, the peripheral portion of the shoulder portion 16b and the pin portion 16c are pressed and contacted with the first metal member W1 while rotating around the rotation axis X of the rotary tool 16, so that the two contacts are made. Friction heat is generated at the part, and this frictional heat is quickly diffused to the part between the two contact parts of the work W (the part where the bottom surface of the annular recess 16d is not in contact), and eventually to the entire joining position P. Then, the entire portion (joining position P) facing the shoulder portion 16b in the first metal member W1 is softened well. Further, the galvanized layer Z applied to the surface of the second metal member W2 is also softened at the joining position P. Thus, by setting the first pressurizing force, the first rotation speed, and the first predetermined time within the preferable ranges, the first metal member W1 can be favorably softened without being sheared. Become.

  Further, in the initial stage of the first pressing step, the pin portion 16c protruding by a predetermined length h from the shoulder portion 16b comes into contact with the first metal member W1 before the shoulder portion 16b. By first bringing the pin portion 16c having such a small diameter into contact with each other, the rotary tool 16 is satisfactorily positioned with a small frictional resistance, and rotational runout in the direction perpendicular to the rotation axis X is suppressed (anchor function). .

  In the subsequent second pressing step, as shown in FIG. 12, the rotating tool 15 is rotated at the second rotational speed by the rotating motor 15, and the second pressing force greater than the first pressing force is applied by the pressing motor 14. With pressure, the shoulder portion 16b and the pin portion 16c of the rotary tool 16 are pushed into the first metal member W1 for a second predetermined time.

  In this second pressing step, the shoulder portion 16b and the pin portion 16c of the rotary tool 16 gradually enter deeply into the first metal member W1 due to the increased pressure, and the entire bottom surface of the annular recess 16d, that is, the pin portion 16c. The entire shoulder portion 16b including the annular recess 16d contacts the first metal member W1. Accordingly, plastic flow is performed in addition to softening of the first metal member W1 (in the figure, the plastic flow Q is schematically indicated by a broken line). Here, when the clearance S is provided between the first metal member W1 and the second metal member W2, the first metal member W1 is pushed out to the second metal member W2 side by the plastic flow Q, and the two closely contact each other. .

  Further, in the plastic flow Q, since the annular recess 16d is provided in the shoulder portion 16b (particularly, the annular recess 16d has a conical shape), the first metal member W1 that plastically flows is in the vertical direction in the figure. It is suppressed from flowing out to the outside from the portion immediately below the rotary tool 16 (joining position P). Further, the second pressurizing force is concentrated at the joining position P by the annular recess 16d, and the plastic flow Q of the first metal member W1 is promoted. Further, the softened galvanized layer Z is pushed out from the joining position P at the joining interface between the first metal member W1 and the second metal member W2, so that the new surface of the second metal member W2 is exposed. However, the oxide film formed on the surface of the first metal member W1 by oxygen in the air is destroyed at the joining position P, so that the new surface of the first metal member W1 is exposed.

  The second applied pressure, the second rotation speed, and the second predetermined time are set so that the rotary tool 16 is not pushed deeper than the predetermined insertion position into the first metal member W1. The predetermined insertion position is a position where the first metal member W1 is excessively thinned and torn when the rotary tool 16 enters deeper than the insertion position.

  Thus, the second pressing step is completed. The completion of the second pressing step may end the bonding at the bonding position P. However, in the present embodiment, the third pressing step is further performed.

  In the third pressing step, as shown in FIG. 13, while the rotary tool 16 is rotated at the third rotational speed by the rotation motor 15, the third pressing force is smaller than the second pressing force by the pressing motor 14. The shoulder portion 16b and the pin portion 16c of the rotary tool 16 are pressed against the first metal member W1 for a third predetermined time.

  In the third pressing step, the rotating tool 16 is not pushed deeper than the predetermined insertion position into the first metal member W1 by making the applied pressure smaller than that in the second pressing step, and the second pressing step is completed. It will continue to be pressed at the time position. This prevents the first metal member W1 from being excessively thin and torn and maintains the same temperature as in the second pressing step, and good plastic flow is performed for a long time. . By the end of the third pressing step, the joining at one joining position P is finished.

  The third pressing force, the third rotation speed, and the third predetermined time continue to press the rotary tool 16 against the first metal member W1 at the position when the second pressing step is completed, and the first metal member W1. Each is set so that plastic flow occurs.

  In the third pressing step, the metal material extruded by the rotary tool 16 becomes a burr R and rises on the surface of the first metal member W1, and the galvanized layer Z is further extruded from the joining position P. The oxide films of the first metal member W1 and the second metal member W2 are further destroyed, and the exposed range of each new surface of the first metal member W1 and the second metal member W2 is expanded (the range indicated by the x mark in FIG. 13). ). As a result, the mating surface portions of the first metal member W1 and the second metal member W2 are solid-phase bonded by friction point bonding, and the bonding strength is stably increased.

  In the vicinity of the joining position P in the galvanized layer Z, a metal mixture layer Y of the metal (aluminum alloy) constituting the first metal member W1 and the metal constituting the galvanized layer Z is generated.

  When the joining at the joining position P is completed, the screw tool is rotated by the pressing motor 14 to raise the rotary tool 16 and the entire joining gun 10 as shown in FIG. 10B. The support 17 is moved away from the base member 75 by being moved in the descending direction of 16. In the joining position P after the completion of the friction spot joining, as shown in FIG. 14, the marks of the shoulder portion 16b and the pin portion 16c remain on the surface of the first metal member W1, and around the shoulder portion 16b, Burr R is generated.

  After spot joining at one joining position P of the first and second metal members W1, W2, joining at another joining position P is performed across the pressing portion 72c. When the friction point welding is completed, the control unit 50a places the welding gun 10 in the standby state by the robot 40. Or when there exists the following joining position P, the joining gun 10 is moved to the joining position P, and the friction point joining similar to the above is repeatedly performed.

  As described above, the pressing jig 72 presses between the adjacent joining positions P of the bottom wall 67a of the recess 67 of the first metal member W1 from above, so that the pressing metal 72 presses the first metal member W1. As it is, the rotary tool 16 is accessed to the joining position P to join one joining position P, and then the joining at the other joining position P is performed across the pressing position A by the pressing jig 72. For this reason, even if the periphery of the rotary tool 16 does not increase in size and the recesses 67 and 68 exist in the shape near the joint, the first metal member W1 is reliably pressed by the pressing jig 72. There is no restriction on the position P. At this time, the outer periphery of the joining position P is stressed at the time of joining due to the rigidity of the corners 67c and 68c (shown in FIG. 9) between the bottom walls 67a and 68a of the highly rigid recesses 67 and 68 and the side walls 67b and 68b. Deformation is suppressed.

-Effect of the embodiment-
As described above, according to the present embodiment, the pressing jig 72 surely presses between the adjacent joint positions P of the bottom wall 67a of the concave portion 67 of the first metal member W1, thereby simplifying the operation. With the configuration, the bottom walls 67a and 68a of the recesses 67 and 68 can be joined with high quality while suppressing deformation due to stress during joining.

(Other embodiments)
The present invention may be configured as follows with respect to the above embodiment.

  That is, in the above embodiment, the case where the present invention is applied to the friction point joining of the first metal member W1 (aluminum alloy) and the second metal member W2 (galvanized steel sheet) is described. You may apply to friction point joining. In this case, the material is not particularly limited, and may be a joining of members made of the same kind of material or a joining of members made of different materials. Further, the number of sheets is not limited to two, and three or more members may be joined at the same time.

  In addition, although a pair of rotary tool insertion holes 72f are provided so as to straddle the pressing portion 72c, two or more pairs may be provided.

  In the present embodiment, the distal end portion 17 a of the receiving member 17 is in contact with the workpiece W via the receiving jig 71 and the base member 75. However, an opening may be provided in the base member 75 so that the distal end portion 17 a of the receiving member 17 is brought into contact with the receiving jig 71. Moreover, you may make it the receptacle 17 contact | abut directly to the workpiece | work W, without passing through a jig | tool. By interposing the jig, it is possible to reliably avoid problems that occur when the receiving member 17 directly contacts the workpiece W. For example, in the case of this embodiment, it is possible to avoid the zinc plating layer Z of the second metal member W2 from adhering to the receiving member 17 due to heat and pressure applied during friction point joining. In addition, when the surface of the workpiece W that comes into contact with the receiving member 17 is the outer surface of the automobile panel, it is also possible to prevent the merchantability from being deteriorated by a slight indentation attached by the receiving member 17.

  The rotary tool 16 or the joining gun 10 may not be mounted on the robot 40. However, when the rotary tool 16 or the joining gun 10 is mounted on the robot 40, there is an advantage that it can be easily performed even in a narrow place by utilizing its high degree of freedom of movement.

  Further, the shape of the shoulder portion 16b of the rotary tool 16 does not have to be formed with the annular recess 16d.

  Various parameters such as the shape (size of each part) and the applied pressure of the rotary tool 16 may be appropriately changed according to the application and various conditions.

  In addition, the above embodiment is an essentially preferable illustration, Comprising: It does not intend restrict | limiting the range of this invention, its application thing, or a use.

It is a schematic block diagram of the friction point joining apparatus which concerns on embodiment of this invention. It is a front view of the joining gun shown in FIG. It is a fragmentary sectional view which expands and shows the front-end | tip part of the rotary tool shown in FIG. It is a front view which shows the principal part of a friction point joining apparatus. It is a top view which shows the principal part of a friction point joining apparatus. It is a front view which expands and shows a mode that a pressing jig presses a workpiece | work. It is the perspective view which looked at the pressing jig from the lower side. It is the work which concerns on embodiment of this invention, Comprising: It is the top view seen from the inner panel side, partially notching the hinge attaching part of the trunk lid of a motor vehicle. FIG. 9 is a cross-sectional view taken along the line IX-IX in FIG. 8, where (a) is an exploded cross-sectional view showing a state before the hinge is attached to the trunk lid, and (b) is a cross-sectional view showing the assembled state. (A) is sectional drawing which shows the state in friction point joining, (b) is sectional drawing which shows the state immediately after friction spot joining. It is sectional drawing which shows the state of Fig.10 (a) in detail, and is explanatory drawing of the 1st press process in friction point joining. It is explanatory drawing of the 2nd press process following the said 1st press process. It is explanatory drawing of the 3rd press process following the said 2nd press process. It is sectional drawing which shows the state which completed the friction point joining after the said 3rd press process.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Friction point joining apparatus 10 Joining gun 14 Pressing motor (drive means)
15 Motor for rotation (drive means)
DESCRIPTION OF SYMBOLS 16 Rotating tool 17 Receiving tool 67, 68 Recessed part 67a, 68a Bottom wall 71 Receiving jig 72 Pressing jig 72c Pressing part 72f Rotating tool insertion hole 73 Moving mechanism 75 Base member 78 Rotating arm 79 Drive cylinder W1 1st metal member W2 Second metal member

Claims (7)

The first metal member and the second metal member both having recesses are overlapped so that the recesses overlap, and by rotating and pressing the rotary tool, a part of the recess bottom wall of the first metal member is softened by frictional heat to cause plastic flow. A friction spot welding device that spot-joins the first and second metal members at a plurality of locations,
A receiving jig for receiving and positioning the second metal member side of the superimposed first and second metal members;
A pressing jig that moves from above to a pressing position that presses between adjacent bonding positions of the concave bottom wall of the first metal member, and a retreat position that retreats from the bonding position;
A moving mechanism for moving the pressing jig to the pressing position and the retracted position;
A friction point joining apparatus, comprising: a driving unit that presses the first metal member from above while rotating the rotary tool while pressing between adjacent joining positions with the pressing jig. In the friction point welding apparatus according to claim 1,
The pressing jig includes a pressing portion disposed in the center and a plurality of rotating tool insertion holes that are disposed so as to straddle the pressing portion and allow the tip of the rotating tool to be inserted therethrough. Friction spot welding device. In the friction point welding apparatus according to claim 1 or 2,
The moving mechanism includes a rotating arm that supports a pressing jig and rotates between a pressing position and a retracted position, and a drive cylinder that rotates the rotating arm. . In the friction point joining device according to any one of claims 1 to 3,
A bonding gun equipped with the rotary tool, a receiving tool arranged to face the rotary tool, and the driving means;
The receiving jig is fixed to the base member that supports the receiving jig, the joining gun is moved to the joining position, the receiving tool is brought into contact with the back side of the receiving jig or the base member, and the rotating tool is rotated. A friction point joining apparatus comprising a moving means for pressing the first and second metal members at each joining position while pressing the first metal member while pressing. In the friction point welding device according to any one of claims 1 to 4,
The first metal member is an aluminum alloy plate,
The second metal member is a steel plate,
A friction point welding apparatus, wherein the first and second metal members are spot-bonded in a solid phase. In the friction point welding apparatus according to claim 5,
The surface of the second metal member is plated, and the friction point joining apparatus is characterized in that In the friction point welding apparatus according to claim 6,
The friction point joining apparatus, wherein the receiving jig is configured to support the entire bottom wall of the concave portion of the second metal member.