JP4479401B2 - Friction spot welding method and apparatus - Google Patents

Description

  The present invention relates to a friction point joining method and apparatus for friction point joining by sandwiching a plurality of stacked metal plate members with first and second rotary tools.

  2. Description of the Related Art Conventionally, a friction point joining method is known by pinching stacked metal plate members while rotating first and second rotary tools each having a protrusion (see, for example, Patent Document 1).

That is, in the friction point joining method, while the first rotary tool is rotated about its axis, the stacked metal plate members are received by the first projecting portion projecting from the first tip surface, and the second While rotating the rotating tool around its axis, the second projecting portion protruding from the second tip surface is pushed into the metal plate member, and the joining part is softened by the frictional heat of both rotating tools and plastically flows to join. is doing. In this way, especially when three or more metal plate members are stacked, the second and third metal plates from the second rotating tool by biting into the metal plate member the first projecting portion protruding from the first tip surface. A more stable plastic flow can be caused to the member.
JP 2001-314983 A

  However, it is difficult to make the rotation axes of the first and second rotating tools completely coincide with each other and push the first and second protrusions into the metal plate member at the same time. When only the first and second protrusions first contact the metal plate member as in the conventional friction point joining method, if there is any deviation in the rotation axis or contact timing of both protrusions, Slip occurs, and the shift of the axial center between the first and second protrusions becomes significant. As a result, a horizontal reaction force against the pressing force of the second rotary tool acts on each rotary tool, and the direction of the horizontal reaction force is constantly changed by the rotation, so that finally a shake occurs. For this reason, even if the first and second protrusions do not sink into a predetermined position and the second tip surface comes into contact with the joint portion, there is no reaction force from the first tip surface. There was a problem that no heat was generated and stable bonding quality could not be obtained.

  Further, in order to reduce the influence of the above-mentioned slip, it is only necessary to increase the rigidity of the support structure of the first and second rotary tools so as to be able to withstand the run-out. Normally, the first and second rotary tools are The connecting gun is connected to the tip of a rotating shaft that is rotated and pressed by the rotating means and the pressing means, and the connecting gun is attached to the tip of the arm of the robot. As a result, there is a limit to the rigidity of the support structure that can be enhanced.

  The present invention has been made in view of such a point, and the object of the present invention is to prevent shake of the axial centers of the first and second rotary tools by adding a device to the configuration of the first rotary tool. It is to obtain a stable bonding quality.

  In order to achieve the above object, according to the present invention, the first projecting portion of the first rotating tool can be moved forward and backward with respect to the first tip surface thereof, and the contact area of the first rotating tool with respect to the metal plate member It can be changed.

  Specifically, the first invention is directed to a method in which a plurality of metal plate members are stacked, and the stacked metal plate members are sandwiched by first and second rotary tools and subjected to friction point bonding.

  Then, the first rotary tool is rotated around its axis in a state where the tip surface of the first protrusion is in the same plane as the first tip surface or is retracted from the first tip surface, After receiving the stacked metal plate members at one front end surface and pushing the second projecting portion protruding from the second front end surface into the metal plate member while rotating the second rotating tool about its axis. The first projecting portion of the first rotating tool is advanced from the first tip surface and pushed into the metal plate member, and the joining portion is softened by the frictional heat of both rotating tools, and is joined by plastic flow.

  According to the above configuration, the first rotary tool is in a state where the tip surface of the first protrusion is in the same plane as the first tip surface, or is retracted from the first tip surface to increase the contact area with the metal plate member. While rotating and receiving the metal plate members stacked on the first front end surface, the second protrusion of the rotating second rotating tool is pushed into the metal plate member to pinch the metal plate member. For this reason, compared with the case where the metal plate member is sandwiched by the first and second protrusions having a small contact area at the same time, the contact area with the metal plate member at the time of contact increases, and the first and second rotary tools have a large contact area. Even if there is a shift in the position of the shaft center or the contact timing, the shaft center of the first and second rotating tools is less likely to be shaken.

  In the second invention, after the second projecting portion of the second rotating tool is pushed into the metal plate member, the first end of the first rotating tool is brought into contact with the metal plate member when the second tip surface comes into contact with the metal plate member. Advance the protrusion.

  According to said structure, after the 2nd front end surface of a 2nd rotary tool contacts a metal plate member, and the contact area becomes larger than when only the 2nd protrusion part is contacting, Since the first protrusion having a smaller diameter than the first tip surface is advanced from the first tip surface, the behavior of the first and second rotary tools is stabilized, and the influence of the shift of the axis between the two rotary tools is affected. Becomes even smaller.

  In 3rd invention, when the 1st protrusion part of the said 1st rotation tool is advanced, the rotation speed of this 1st rotation tool is increased.

  That is, when the first rotary tool is brought into contact with the metal plate member, since the first protruding portion is in a flat state in which the first projecting portion is retracted, there is no centering effect. However, in the present invention, when the first projecting portion of the first rotating tool advances and presses the metal plate member and starts to exert the centering effect, the rotational speed of the first rotating tool is increased. As a result, skidding does not occur and the occurrence of shake is prevented.

  In 4th invention, the said metal plate member shall consist of a metal plate piled up three sheets.

  According to the above configuration, when three metal plate members are stacked, only the second rotary tool can cause a stable plastic flow from the second rotary tool to the second and third metal plate members. Therefore, it is necessary to cause the first projecting portion of the opposing first rotating tool to project, and to cause a stable plastic flow to the second and third metal plate members at the first projecting portion. For this reason, presence of a 1st protrusion part becomes essential and the effect of this invention is exhibited notably.

  The fifth invention is directed to an apparatus for holding a plurality of stacked metal plate members by means of first and second rotary tools and performing friction point joining.

  The first rotating tool has a first protrusion that can be moved forward and backward with respect to the first tip surface, while the second rotating tool is disposed to face the first rotating tool, A first rotating means for rotating the first rotating tool; and a moving means for moving the first protruding part of the first rotating tool forward or backward. A second rotating means for rotating the second rotating tool; a pressing means for pressing the second rotating tool against the metal plate member; and the first rotating means to move the first rotating tool to the front end surface of the first projecting portion. Is in the same plane as the first tip surface, or is rotated around its axis in a state of being retracted from the first tip surface to support the metal plate members stacked on the first tip surface, and The second rotating tool is moved by the two rotating means. The second projecting portion is pushed into the metal plate member by the pressing means while rotating around the center, and then the first projecting portion of the first rotating tool is moved forward from the first tip surface by the moving means. And a control means for pressing into the metal plate member, softening the joining portion by the frictional heat of both rotary tools, and joining them by plastic flow.

  According to said structure, a control means makes the front end surface of a 1st protrusion part in the same plane as a 1st front end surface, or retracted rather than the 1st front end surface, and enlarged the contact area with respect to a metal plate member. In this state, the first rotating tool is rotated by the first rotating means, the second rotating tool is rotated by the second rotating means while receiving the metal plate members stacked on the first tip surface, and the second protrusion is pressed by the pressing means. The metal plate member is sandwiched by pushing the portion into the metal plate member. For this reason, compared with the case where the metal plate member is sandwiched by the first and second protrusions having a small contact area at the same time, the contact area with the metal plate member at the time of contact increases, and the first and second rotary tools have a large contact area. Even if there is a shift in the position of the shaft center or the contact timing, the shaft center of the first and second rotating tools is less likely to be shaken.

  In a sixth invention, the control means advances the first protrusion of the first rotary tool by the moving means when the second tip surface of the second rotary tool comes into contact with the metal plate member. It is configured as follows.

  According to said structure, after a 2nd front end surface contacts a metal plate member and the contact area becomes larger than when only the 2nd protrusion part is contacting, it is from the 1st front end surface of a 1st rotation tool. Since the first protrusion having a smaller diameter than that of the first tip surface is advanced, the behavior of the first and second rotary tools is stabilized, and the influence of the deviation of the axial center between the two rotary tools is further reduced.

  In a seventh aspect, the control means is configured to increase the number of rotations of the first rotating tool by the first rotating means when the first protrusion of the first rotating tool is advanced. Yes.

  That is, when the first rotating tool is brought into contact with the metal plate member, since the first protruding portion is in a flat state in which the first projecting portion is retracted, there is no centering effect. In the present invention, when the first protrusion of the first rotary tool advances and presses the metal plate member, the control means issues a command to the first rotary means to increase the rotation speed of the first rotary tool. Therefore, the side slip is prevented by the centering effect of the first projecting portion, and the occurrence of shake is prevented.

  As described above, according to the first and fifth aspects of the present invention, the stacked metal plate members are arranged such that the tip surface of the first protrusion is in the same plane as the first tip surface or from the first tip surface. The second projecting portion of the rotating second rotating tool is pushed and held while being received by the first tip surface of the first rotating tool rotating in the retracted state, and then the first projecting portion of the first rotating tool is moved to the first position. 1 It is advanced from the front end surface and pushed into the metal plate member, and the joining portion is joined by plastic flow by frictional heat of both rotary tools. For this reason, when the metal plate member is first sandwiched, it is supported by a large area portion of the first rotary tool, so that the shaft tip does not shake between the first and second rotary tools, and the second tip When the surface comes into contact with the joining portion, a sufficient reaction force is obtained from the first tip surface, so that a necessary heat input amount is generated at the joining portion. Therefore, stable joining quality can be obtained without increasing the rigidity of the support structure of the first and second rotary tools.

  According to the second and sixth inventions, when the second tip surface having a large contact area comes into contact with the metal plate member, the first protrusion is advanced from the first tip surface to press the metal plate member. ing. For this reason, the behavior of the first and second rotary tools is stabilized, the influence of the shift of the axis between the two rotary tools is reduced, and further stable joining quality can be obtained.

  In the said 3rd and 7th invention, when the 1st protrusion part of the 1st rotation tool is advanced, the rotation speed of the 1st rotation tool is increased. For this reason, the centering effect of the first protruding portion can surely prevent the run-out and obtain a stable joint quality.

  According to the fourth aspect of the present invention, the metal plate is formed by stacking three metal plate members. For this reason, in order to cause a stable plastic flow from the second rotary tool to the second and third metal plate members, the presence of the first protrusion is essential, and the effects of the present invention are remarkably exhibited.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In addition, the following embodiment is an essentially preferable illustration, Comprising: It does not intend restrict | limiting the range of this invention, its application thing, or a use.

-Configuration of friction spot welding device-
FIG. 1 shows a schematic configuration of a friction point welding apparatus 1 according to an embodiment of the present invention. The friction point joining apparatus 1 is configured to join a plurality of metal plate members made of light metal such as an aluminum alloy used for an automobile body or the like in a state of being stacked in a thickness direction.

  The joining apparatus includes a joining gun 2 that joins workpieces W. The work W includes three first to third metal plate members W1, W2, and W3 (shown in FIG. 2). The joining gun 2 is attached to the tip of the arm 3a of the robot 3 and is positioned by the robot 3 at the joining position of the workpiece W fixed to a jig (not shown) to join the workpiece W. Yes.

  As the robot 3, for example, a general-purpose 6-axis vertical articulated robot 3 can be used. The robot 3 is connected to a control panel 5 as control means by a robot harness 4. The joining gun 2 is also connected to the control panel 5 by a joining gun harness 7 via a relay box 6 provided in the robot 3.

  As shown in FIG. 2, the joining gun 2 includes a first rotating tool 20 and a second rotating tool 10.

  The second rotating tool 10 is disposed on the upper side of the joining axis X perpendicular to the overlapping surfaces S1, S2 of the stacked metal plate members W1, W2, W3, and is attached to the tip of the rotating shaft 9. . The second rotary tool 10 has a tip formed in a cylindrical shape, and a second projecting portion 12 (shown in FIG. 4) having a smaller diameter is joined to the second tip surface 11 of the tip. It protrudes so as to extend on X. The length of the second protrusion 12 is determined according to the thickness of the first metal plate member W1. The outer diameter is, for example, 2 to 5 mm. Although the mechanism inside the joining gun 2 is not described in detail, the second rotating tool 10 is rotated around the joining axis X (for example, by the second rotating shaft motor 13 as the second rotating means via the rotating shaft 9). It is configured to rotate counterclockwise in FIG. Further, the second rotary tool 10 is configured to move up and down on the joining axis X by operating a bolt-nut type moving mechanism (not shown) by a pressing shaft motor 14 as a pressing means to move the rotating shaft 9. Yes. An induction motor or a servo motor can be used as the second rotating shaft motor 13, and a servo motor can be used as the pressing shaft motor 14.

  On the other hand, as shown in FIG. 3, the first rotary tool 20 is attached to the tip of a substantially L-shaped gun arm 8. Thus, the first rotary tool 20 and the second rotary tool 10 are arranged to face each other. The first rotary tool 20 has a cylindrical shape, and the first tip surface 21 which is the tip surface thereof has an outer shape equal to or larger than the second tip surface 11 of the second rotary tool 10. ing. Further, the first rotary tool 20 is provided with a through hole 22 extending in the axial direction at the center, and a cylindrical first that can be moved forward and backward with respect to the first tip surface 21 inside the through hole 22. A protruding portion 23 is provided. The outer diameter of the 1st protrusion part 23 shall be 2-5 mm, for example.

  And the 1st rotation motor (not shown) as a 1st rotation means which rotates the said 1st rotation tool 20 to the said joining gun 2, and the 1st protrusion part 23 of the 1st rotation tool 20 are moved forward or backward. Moving means 25 is provided.

  Specifically, the lower portion of the first rotary tool 20 is rotatably supported by three bearings 40 provided on the gun arm 8, and the second rotary tool 20 is driven by the timing belt 24 driven by the first rotary motor. It is rotated in the direction opposite to the rotary shaft motor 13 (clockwise in FIG. 4).

  The moving means 25 is composed of the following members. That is, the lower end portion of the first projecting portion 23 is coupled to the screw member 42 extending on the joining axis X by the joint 41. The screw member 42 is screwed with a ball spline 44 having a screw on the inner side and a first gear 43 on the outer periphery thereof. A lower end portion of the screw member 42 is rotatably supported by a support member 45 provided on the gun arm 8. The first gear 43 meshes with a second gear 46 having an axis that is perpendicular to the axis (joint axis X) of the screw member 42. The first gear 43 and the second gear 46 are immediately bevel gears. The second gear 46 is coupled to the rotation shaft of the third rotation shaft motor 47. With such a configuration of the moving unit 25, the rotation shaft of the third rotation shaft motor 47 rotates to rotate the second gear 46, and the rotational force is transmitted to the first gear 43. As a result, the ball spline 44 rotates and the screw member 42 moves up and down, so that the first protrusion 23 moves up and down.

  The control panel 5 includes the six axes of the robot 3, the first rotation motor provided on the joining gun 2, the second rotation axis motor 13, the pressing axis motor 14, and the third rotation axis motor 47 of the moving means 25. The total 10 axes are configured to be synchronously controlled. When the control panel 5 is driven by the first rotary motor, the front end surface of the first projecting portion 23 is in the same plane as the first front end surface 21 or retreats from the first front end surface 21. In this state, the metal plate members W1, W2, and W3 stacked on the first tip surface 21 are supported around the joint axis X, and the second rotating tool 10 is moved by the second rotating shaft motor 13. The second projecting portion 12 is pushed into the metal plate members W1, W2, and W3 by the pressing shaft motor 14 while rotating around the joining axis X, and then the first projecting of the first rotating tool 20 by the moving means 25. The portion 23 is advanced from the first tip surface 21 and pushed into the metal plate members W1, W2, and W3, and is softened by the frictional heat of the rotary tools 10 and 20, so that the joining portions are joined by plastic flow. To your.

-Work W Joining Method 1 (Monitoring Method)-
Next, the joining method 1 of the workpiece | work W by the friction point joining apparatus 1 concerning embodiment of this invention is demonstrated.

  (1) First, the initial state of the friction spot welding apparatus 1 will be described.

  The workpiece W is fixed by a jig (not shown). The first protrusion 23 of the first rotary tool 20 is in the same plane as the first tip surface 21 or is in a state of being retracted with respect to the first tip surface 21. The robot 3 is at the origin position, and the joining gun 2 is at the open end position (that is, the state where the second rotary tool 10 is farthest from the first rotary tool 20).

  (2) Next, the teaching work of the robot 3 will be described.

  First, the welding parameters such as the applied pressure, the rotation speed, and the time are input.

  Next, the origin position for monitoring the position of the second rotary tool 10 by the pressing shaft motor 14 is taught. That is, the state in which the metal plate members W1, W2, and W3 are sandwiched between the second rotary tool 10 and the first rotary tool 20 is taught. The encoder value of the pressing shaft motor 14 corresponding to the position of the second rotary tool 10 at that time is set to zero.

  Next, the timing at which the first projecting portion 23 of the first rotating tool 20 is advanced is determined by a predetermined distance from the origin in the pressing direction of the second rotating tool 10 (that is, the second projecting portion 12 of the second rotating tool 10). And the distance is input as a parameter.

  Next, the maximum protrusion length by which the first protrusion 23 of the first rotary tool 20 is advanced is input as a parameter. The maximum protrusion length of the first protrusion 23 is 60 to 80% of the plate thickness of the third metal plate member W3, for example, about 0.6 to 3 mm.

  (3) Next, the operation of the robot 3 will be described.

  First, the robot 3 starts operating from the origin.

  Next, the joining gun 2 is positioned by the robot 3 at the teaching point immediately before the pressurizing point. Specifically, as shown in FIG. 4, the workpiece W is positioned between the first and second rotary tools 10 and 20 of the bonding gun 2 and the bonding portion of the workpiece W is positioned on the bonding axis X.

  Next, as shown in FIG. 5, the first rotating tool 20 is rotated around the joining axis X by the first rotating shaft motor in a state where the first protruding portion 23 is flush with the first tip surface 21. The stacked metal plate members W1, W2, and W3 are received by the first tip surface 21. At the same time, the second rotating tool 10 is rotated about the joining axis X by the second rotating shaft motor 13 while the second projecting portion 12 of the second rotating tool 10 is moved to the first metal plate member W1 by the pressing shaft motor 14. Push in. Thus, the metal plate members W1, W2, and W3 are held between the first and second rotary tools 10 and 20.

  Next, pressurization of the second rotary tool 10 is started. Thereby, the 2nd protrusion part 12 sinks in the 1st metal plate member W1.

  Next, the second rotary tool 10 is further pushed in, and the second protrusion 12 sinks to the area of the second metal plate member W2.

  Next, as shown in FIG. 6, when the second rotary tool 10 is further pushed in and the second tip surface 11 comes into contact with the first metal plate member W1, the first rotary tool is moved by the moving means 25. The 20 first protrusions 23 are advanced and pushed into the third metal plate member W3. Specifically, when the position of the second rotary tool 10 is monitored on the control panel 5 and the second rotary tool 10 has passed through a predetermined position taught (advanced to the length of the second protrusion 12). In addition, a command is issued to the moving means 25 to advance the first protrusion 23.

  Next, the 1st protrusion part 23 is moved to the largest protrusion length toward the inside of the workpiece | work W with the moving means 25, and a joining site | part is softened by the frictional heat of both rotary tools 10 and 20. FIG.

  As a result, as shown in FIG. 7, plastic flow occurs in the workpiece W, and the second protrusion 12 leaves a continuous interface S1 between the first metal plate member W1 and the second metal plate member W2. Thus, the first recess 31 is formed. On the outer side of the first recess 31, an annular first swelled portion 33 is formed in which the second plate material W2 swells toward the first plate material W1 over the entire circumference. Moreover, the 2nd recessed part 32 is formed leaving the continuous interface S2 between the 2nd metal plate member W2 and the 3rd metal plate member W3. On the outer side of the second recess 32, an annular second raised portion 34 is formed in which the second metal plate member W2 swells toward the third metal plate member W3 over the entire circumference.

  In addition, since the timing which advances the 1st protrusion part 23 is delayed rather than the time when the 2nd rotary tool 10 contact | abuts, it is between the press time by the 2nd protrusion part 12, and the press time by the 1st protrusion part 23. There is a difference. From this, in order to obtain stable joining quality, the plate thickness of the first metal plate member W1 on the second rotary tool 10 side is larger than the plate thickness of the third metal plate member W3 on the first rotary tool 20 side. It is desirable.

  Next, when the joining time reaches the time taught in advance, the operation is switched to the opening operation. Specifically, as shown in FIG. 7, the second rotary tool 10 is moved backward by the pressing shaft motor 14 and pulled out from the workpiece W while the first and second rotary tools 10 and 20 are rotated. As a result, the workpiece W is rapidly cooled, cured, and bonded.

  Next, the rotation of the first and second rotary tools 10 and 20 is stopped in a state of being separated from the joining position by a predetermined distance set in advance, and the first protrusion 23 of the first rotary tool 20 is moved to the first tip surface. Retreat to the same plane as 21.

  Next, the joining gun 2 is positioned at the teaching release point.

  Then, the joining gun 2 moves to the next teaching point, and the joining of the workpiece W is repeated.

-Work W joining method 2 (Method by time setting)-
Next, a joining method different from the joining method 1 for the workpiece W will be described. The joining method 1 is a joining method based on monitoring, whereas the joining method 2 is a joining method based on time setting.

  (1) First, the initial state is the same as that of the bonding method 1 described above.

  (2) Next, the teaching work of the robot 3 is almost the same as the joining method 1 described above, but the time at which the pressurization point taught by the second rotary tool 10 is reached during automatic operation is used as a time reference. When a predetermined time has passed from there, the first protrusion 23 is brought out.

  (3) Next, the operation of the robot 3 will be described.

  First, the robot 3 starts operating from the origin.

  Next, the joining gun 2 is positioned by the robot 3 at the teaching point immediately before the pressurizing point in a state where the joining axis X-axis coincides with the joining direction of the workpiece W.

  Next, similarly to the joining method 1, the first rotary tool 20 and the second rotary tool 10 are brought into contact with the metal plate members W1, W2, W3 at the same timing, and the metal plate members W1, W2, W3 are narrowed. Hold it.

  Next, pressurization of the second rotary tool 10 is started. Thereby, the 2nd protrusion part 12 sinks in the 1st metal plate member W1.

  Next, the second rotary tool 10 is further pushed in, and the second protrusion 12 sinks to the area of the second metal plate member W2.

  Next, when a predetermined time has elapsed since the second rotary tool 10 has started pressing (in contact with the first metal plate member W1), the moving means 25 causes the first rotary tool 20 to be The first protrusion 23 is advanced and pushed into the third metal plate member W3.

  Next, the 1st protrusion part 23 is moved to the largest protrusion length toward the inside of the workpiece | work W with the moving means 25, and a joining site | part is softened by the frictional heat of both rotary tools 10 and 20. FIG. The moving distance of the first protrusion 23 may be after a predetermined time has elapsed from the start of pressurization of the second shoulder, and the distance advanced by the predetermined distance is detected from the encoder value of the third rotary shaft motor 47. May be.

  Since the subsequent operation is the same as that of the bonding method 1, the description thereof is omitted.

-Effect of the embodiment-
Therefore, according to the friction point joining apparatus 1 according to the embodiment of the present invention, the stacked metal plate members W1, W2, and W3 are arranged so that the front end surface of the first protrusion 23 is in the same plane as the first front end surface 21. Alternatively, after receiving the first tip surface 21 of the first rotating tool 20 that rotates in a state of being retracted from the first tip surface 21, the second projecting portion 12 of the rotating second rotating tool 10 is pushed in and pinched, The first projecting portion 23 of the first rotary tool 20 is advanced from the first tip surface 21 and pushed into the metal plate members W1, W2, and W3, and the joint portion is plastically flowed by the frictional heat of the rotary tools 10 and 20. Are joined. For this reason, when the metal plate members W1, W2, W3 are initially held, they are supported by a wide area portion of the first rotary tool 20, so that the axial center between the first and second rotary tools 10, 20 is supported. When the second tip surface 11 is brought into contact with the joining portion without any shaking, a sufficient reaction force can be obtained from the first tip surface 21, so that a necessary heat input amount is generated at the joining portion. Therefore, stable joint quality can be obtained without increasing the rigidity of the support structure of the first and second rotary tools 10 and 20.

  In addition, when the second tip surface 11 having a large contact area comes into contact with the first metal plate member W1, the first protrusion 23 is advanced from the first tip surface 21 to press the third metal plate member W3. ing. For this reason, the behavior of the first and second rotary tools 10 and 20 is stabilized, the influence of the shift of the axial center between the rotary tools 10 and 20 is reduced, and further stable joining quality can be obtained.

  Furthermore, when the 1st protrusion part 23 of the 1st rotation tool 20 is advanced, the rotation speed of the 1st rotation tool 20 is made to increase. For this reason, the centering effect of the first projecting portion 23 can surely prevent misalignment and obtain stable joint quality.

  Moreover, it shall consist of a metal plate which laminated | stacked three metal plate members W1, W2, and W3. For this reason, in order to cause a stable plastic flow to the second and third metal plate members W2, W3, the presence of the first protrusion 23 is essential, and the operational effects of the present embodiment are remarkably exhibited.

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

  That is, in the said embodiment, although the workpiece | work W shall consist of the metal plate laminated | stacked three sheets, when 4 or more pieces may be sufficient, the case where one part is two pieces may be sufficient. In the case where a part is made of two metal plates, the two parts need only be subjected to friction point joining while the first projecting portion 23 is retracted, so that the process of replacing both rotary tools 10 and 20 is not necessary. , Work efficiency is greatly improved.

  Moreover, in the said embodiment, although the 1st and 2nd protrusion parts 12 and 23 shall consist of solid pins, for example, while making a pin of a smaller diameter protrude from the front end surface of the 2nd protrusion part 12, A recess corresponding to the small-diameter pin may be provided on the distal end surface of the first protrusion 23, and the workpiece W may be caulked with the pin and the recess.

  As described above, the present invention is useful for a friction point joining method and apparatus for joining a plurality of metal plate members used in an automobile body or the like in a pointed state in a stacked state.

It is a schematic explanatory drawing of the friction point joining apparatus concerning the embodiment of the present invention. It is a side view of a joining gun. It is side surface sectional drawing which expands and shows the moving means of the 1st protrusion part of a 1st rotation tool. It is an expanded side view of the joining site | part vicinity of the workpiece | work which shows the process before joining. FIG. 5 is a view corresponding to FIG. 4 illustrating a process at the start of bonding. FIG. 5 is a view corresponding to FIG. 4 showing a process during bonding. FIG. 5 is a view corresponding to FIG. 4 illustrating a process after joining.

Explanation of symbols

1 Friction spot welding device 5 Control panel (control means)
DESCRIPTION OF SYMBOLS 10 2nd rotation tool 11 2nd front end surface 12 2nd protrusion part 13 2nd rotating shaft motor (2nd rotation means)
14 Press shaft motor (pressing means)
20 1st rotation tool 21 1st front end surface 23 1st protrusion part 25 Moving means W1, W2, W3 Metal plate member

Claims (7)

A method of stacking a plurality of metal plate members, and sandwiching the stacked metal plate members with first and second rotary tools to perform friction point joining,
The first tip is rotated around its axis in a state where the tip surface of the first protrusion is in the same plane as the first tip surface or retracted from the first tip surface. After receiving the stacked metal plate members on the surface and rotating the second rotating tool around its axis, the second protruding portion protruding from the second tip surface is pushed into the metal plate member,
The first projecting portion of the first rotating tool is advanced from the first tip surface and pushed into the metal plate member, and the joining portion is softened by the frictional heat of both rotating tools and joined by plastic flow. Friction spot joining method. In the friction point joining method according to claim 1,
After the second projecting portion of the second rotating tool is pushed into the metal plate member, the first projecting portion of the first rotating tool is advanced when the second tip surface comes into contact with the metal plate member. Friction point joining method characterized by the above. In the friction point joining method according to claim 1 or 2,
A friction point joining method, wherein when the first protrusion of the first rotating tool is advanced, the number of rotations of the first rotating tool is increased. In the friction point joining method according to any one of claims 1 to 3,
3. The friction point joining method according to claim 1, wherein the metal plate member is made of three stacked metal plates. In an apparatus for holding a plurality of stacked metal plate members with a first and second rotary tool to perform friction point joining,
The first rotating tool has a first protrusion that can be moved forward and backward with respect to the first tip surface, while the second rotating tool is disposed to face the first rotating tool, and the second Having a second protrusion fixed to the tip surface;
First rotating means for rotating the first rotating tool;
Moving means for advancing or retracting the first protrusion of the first rotating tool;
Second rotating means for rotating the second rotating tool;
Pressing means for pressing the second rotating tool against the metal plate member;
By means of the first rotating means, the first rotating tool is rotated about its axis in a state where the tip surface of the first protrusion is in the same plane as the first tip surface or is retracted from the first tip surface. The metal plate member stacked on the first tip surface is supported, and the second projecting portion is moved to the metal plate by the pressing means while the second rotating tool is rotated about its axis. After being pushed into the member, the first projecting portion of the first rotating tool is advanced from the first tip surface by the moving means and pushed into the metal plate member, and is softened by the frictional heat of both rotating tools. And a friction point joining apparatus characterized by comprising control means for joining by plastic flow. In the friction point welding apparatus according to claim 5,
The control means is configured to advance the first protrusion of the first rotary tool by the moving means when the second tip surface of the second rotary tool comes into contact with the metal plate member. A friction point welding apparatus characterized by that. In the friction point joining apparatus according to claim 5 or 6,
The control means is configured to increase the number of rotations of the first rotating tool by the first rotating means when the first protrusion of the first rotating tool is advanced. Friction spot welding device.

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