JP2007083295A - Method and device for treating rotary tool of friction spot welding device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To efficiently remove deposits by performing an adequate treatment when a part of a workpiece is deposited on a shoulder part of a rotary tool. <P>SOLUTION: In a rotary tool treatment device 60 of a friction spot welding device, a plurality of metallic members overlap each other, and a rotary tool 16 is rotatably pressed against the metallic members to perform the spot welding. The rotary tool treatment device 60 comprises a driving means for rotatably pressing the rotary tool 16 against the metallic members, a moving means for moving the rotary tool 16 to the welding position, a detection means for detecting any deposition state of the metallic members on a shoulder part 16b, and a control means which locates the rotary tool 16 facing a metallic member W3 for treatment by the moving means when the detection signal by the detection means indicates the deposition state of a predetermined value or over, presses a pin part 16c and a shoulder part 16b against the metallic member W3 for treatment while rotating the rotary tool 16 by the driving means, and performs the operation of removing deposits W1a. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  TECHNICAL FIELD The present invention relates to a friction point welding apparatus that stacks a plurality of metal members and spot-joins the metal members with frictional heat using a rotary tool, and more specifically, when a metal member adheres to the rotary tool. The present invention relates to a rotating tool processing method and apparatus.

2. Description of the Related Art In recent years, aluminum alloy materials and the like have come to be widely used in automobile bodies and the like for the purpose of weight reduction and the like, for example, members made of aluminum alloy materials are joined together or made of aluminum alloy materials. Opportunities for joining members and members made of iron or steel materials are increasing. Since it is difficult to perform such joining by welding, rivet joining is usually performed, but this rivet joining increases the cost.

  Therefore, friction point welding is known as a suitable method for performing such joining at a low cost. In this method, a plurality of metal members are overlapped, the pin part and the shoulder part are pressed against the metal member while rotating the rotary tool provided with the pin part protruding from the shoulder part, and the metal member is softened by frictional heat. The metal members are spot-bonded by causing plastic flow. In this joining, workpieces (metal members to be joined) are solid-phase joined (joining in a solid state without melting) at a temperature equal to or lower than the melting point.

For example, Patent Document 1 discloses a method and apparatus for friction point bonding of a galvanized steel plate and an aluminum plate. As shown in Patent Document 1, a rotary tool is generally a columnar shape and is driven to rotate around an axis. And the shoulder part formed in the edge part of the approximate cylinder is pressed against a work. A pin portion which is a minute protrusion is formed at the center of the shoulder portion.
JP 2005-34879 A

  For example, when the workpiece is an automobile panel or the like, since there are many joint points, it is efficient to perform friction point joining continuously. However, there is a case where a part of the workpiece adheres (attaches) to the shoulder portion while repeating the friction point joining many times. For example, in the case of joining dissimilar metals as shown in Patent Document 1, it is preferable that the shoulder portion has a shape in which the central portion excluding the pin portion is slightly recessed (an annular recess is formed). In such a case, adhesion to the shoulder portion is particularly likely to occur.

  When the friction spot welding is performed in a state where there are many adhered objects around the shoulder portion, in particular, the pin portion, the rotational runout of the rotary tool at the time of joining becomes large. Therefore, there is a possibility that the bonding quality is deteriorated. Moreover, there is a risk of damage to the rotary tool, its drive mechanism, or the surrounding jig.

  In view of the circumstances as described above, the present invention provides a rotation of a friction point joining apparatus capable of efficiently removing an adherent by performing an appropriate process when a part of a workpiece adheres to a shoulder portion of a rotary tool. An object is to provide a tool processing method and apparatus.

  The invention according to claim 1 for solving the above-mentioned problem is that the plurality of metal members are overlapped, and the pin part and the shoulder part are attached to the metal member while rotating a rotary tool having a pin part protruding from the shoulder part. A rotary tool processing method for a friction point joining apparatus that softens the metal member with frictional heat and causes plastic flow to cause spot welding of the metal members, after at least one joining. In the adhesion state detection step of detecting the adhesion state of the metal member to the shoulder portion by a detecting means, and in the adhesion state detection step, when the adhesion state is detected to be a predetermined value or more. An agglomerated material removal step that is performed, wherein the agglomerated material removing step removes the agglomerated material by pressing the pin portion and the shoulder portion against the processing metal member while rotating the rotary tool. And characterized in that.

  In the invention according to claim 2, a plurality of metal members are overlapped, and the pin part and the shoulder part are pressed against the metal member while rotating a rotary tool provided with a pin part protruding from the shoulder part. In the rotary tool processing apparatus of the friction point welding apparatus that softens the metal member and causes the metal members to spot-bond by causing plastic flow, the pin part and the shoulder part are rotated while the rotary tool is rotated. A driving unit that presses against the metal member; the rotating tool; and the driving unit, and a moving unit that moves the rotating tool to a joining position; When the detection means for detecting the adhesion state of the metal member and the detection signal by the detection means indicate that the adhesion state is equal to or greater than a predetermined value, the rotation means performs the rotation process. Is disposed opposite to the processing metal member, and while the rotating tool is rotated by the driving means, the pin portion and the shoulder portion are pressed against the processing metal member to remove the adhered matter. And a control means for performing the operation.

  According to a third aspect of the present invention, in the rotary tool processing apparatus of the friction point joining apparatus according to the second aspect, the detection means includes a detection plate disposed so as to be substantially in contact with the shoulder portion, and the shoulder portion. A displacement sensor that detects the amount of displacement of the detection plate when substantially contacting the detection plate, and the detection plate moves to the shoulder portion when the shoulder portion substantially contacts the detection plate. It is comprised so that it may displace by the displacement amount according to the adhesion state of said metal member.

  According to a fourth aspect of the present invention, in the rotary tool processing apparatus of the friction point joining apparatus according to the second or third aspect, the shoulder portion is formed with an annular concave portion surrounding the pin portion. And

  According to a fifth aspect of the present invention, in the rotary tool processing apparatus for a friction point welding apparatus according to any one of the second to fourth aspects, the moving means is a robot.

  According to the first aspect of the present invention, as described below, when a part of the workpiece adheres to the shoulder portion of the rotary tool, it is possible to efficiently remove the adhered matter by performing an appropriate process.

  Since the metal material adheres relatively firmly, it is difficult to remove by a pure mechanical removal method, for example, a method using a chisel or the like. Even if it can be removed, there is a great concern that the rotary tool is damaged.

  However, according to the present invention, by performing the adhering substance removing step, the adhering metal material (adhesive substance) is softened, plastic flow is caused, and this is transferred to the processing metal member. Adhesives can be easily removed without damaging the tool.

  Moreover, according to this invention, an adhesion thing removal process can be performed at the suitable timing when adhesion more than a predetermined value was detected. That is, efficiency can be improved by minimizing the frequency of execution of the agglomerate removal step.

  As described above, according to the present invention, when a part of the workpiece adheres to the shoulder portion of the rotary tool, it is possible to efficiently remove the adhered matter by performing an appropriate process. And by always keeping the adhesion state below the predetermined value, the rotational runout of the rotating tool during joining is suppressed, so it is possible to effectively suppress the deterioration of joining quality and damage to each part including the rotating tool. Can do.

  According to the invention of claim 2, the rotary tool processing device of the friction point joining device has the same effect as the effect described in claim 1.

  According to the invention of claim 3, by detecting the adhesion state to the shoulder portion via the detection plate, the adhesion state can be converted into the displacement of the detection plate and detected by the displacement sensor. Therefore, the adhesion state can be easily detected.

  In addition, since the detection plate can be easily displaced by appropriately amplifying the adhesion state of the shoulder portion, the detection accuracy can be improved with a simple structure.

  According to invention of Claim 4, it can apply especially effectively with respect to the rotary tool which has the cyclic | annular recessed part which adhesion occurs easily.

  According to the fifth aspect of the present invention, by using a robot having a high degree of freedom of movement as the moving means, it is possible to easily perform the operation of detecting the adhesion state and the operation of removing the adhered material. Further, these operations can be appropriately incorporated between the friction point joining operations of the workpieces so that the entire operation can be performed efficiently.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. First, the friction point joining apparatus 1 according to the present invention will be described.

  FIG. 1 is a schematic configuration diagram of a friction point welding apparatus 1. The friction point joining apparatus 1 includes a joining gun 10 and a robot 40 (moving means) including the joining gun 10 on a wrist as main components. As the robot 40, 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 and 54.55 and a relay 53. A control unit 50a (control means) is built in the control panel 50, and controls the robot 40 to operate the joining gun 10 so as to have a predetermined position and inclination set in advance. Further, the control unit 50a controls a pressing motor 14 and a rotating motor 15 (see FIG. 2), which will be described later, mounted on the joining gun 10, and the joining tool 18 including the rotating tool 16 and the receiving tool 17 A predetermined operation set in advance is performed.

  FIG. 2 is a front view of the joining gun 10, and FIG. 3 is a side view of the joining gun 10. As shown in these drawings, 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 the mounting box 11 above the arm 12. It has a main body case 13 attached to the side surface, a pressing motor 14 connected to a harness 54, and a rotating motor 15 connected to a 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, at the distal end portion of the arm 12, a receiving tool 17 that is the other of the welding tools 18 is provided facing the rotating tool 16 and the axial center X direction of the rotating tool 16.

  Friction point joining is performed by sandwiching a work (a plurality of superimposed metal members) between the rotary tool 16 and the support 17. Specifically, one surface of the workpiece is received in contact with the tip of the receiving tool 17, and the other surface of the workpiece is pressed against the tip of the rotary tool 16 that rotates about the axis X as described later. Is configured to perform friction point welding.

  4 is a cross-sectional view showing the internal structure of the main body case 13, and FIG. 5 is a cross-sectional view taken along the line VV of FIG. Inside the main body case 13, screw shafts (elevating shafts) 24 and spline shafts (rotating shafts) 25 extending in the vertical direction in parallel with each other are provided so as to be rotatable around respective axis centers. The upper ends of the shafts 24 and 25 penetrate the upper lid member 21 and reach the upper cover 22, where the driven pulleys 26 and 27 are assembled to the shafts 24 and 25, respectively. As shown in FIG. 5, the upper lid member 21 and the upper cover 22 protrude from the upper portion of the main body case 13 to the side of the main body case 13, and the pressing motor 14 and the rotation are formed on the lower surface of the protruding portion of the upper lid member 21. The motor 15 is fixed. The front end portions (upper end portions) of the output shafts 14a and 15a of both the motors 14 and 15 pass through the upper cover member 21 to reach the upper cover 22, where drive pulleys 14b and 15b are connected to the output shafts 14a and 15a. Each is assembled. A drive transmission belt 28.29 is wound around each of the drive pulleys 14b, 15b and the driven pulleys 26, 27, and the screw shaft 24 is rotated by the rotation of the pressing motor 14. 5 is rotated in the A direction (down direction) or the B direction (up direction), and the rotation of the motor 15 for rotation causes the spline shaft 25 to be rotationally driven in the C direction of FIG.

  Returning to FIG. 4, the description will be continued. The elevating block 31 is screwed to the screw portion 24 a of the screw shaft 24, and the rotating cylinder 35 is splined to the spline portion 25 a of the spline shaft 25. The rotating cylinder 35 is rotatably provided inside an elevating cylinder 33 integrally coupled to the elevating block 31 via a coupling member 32. The spline shaft 25, the elevating cylinder 33, and the rotating cylinder 35 are arranged concentrically with each other. Hereinafter, an integrated body of the lifting block 31, the coupling member 32, and the lifting cylinder 33 is referred to as a lifting body 30.

  A cylindrical downward projecting portion 13a is formed on the lower surface of the main body case 13, and a lower cover 23 is provided at the lower end portion of the downward projecting portion 13a. The lower end portions of the elevating cylinder body 33 and the rotating cylinder body 35 penetrate the lower cover 23 and protrude downward. The rotating cylinder 35 on the inner side protrudes downward longer than the lifting cylinder 33 on the outer side, and the attachment member 36 is fixed to the lower end portion of the rotating cylinder 35. A base end portion that is an end portion on the opposite side of the tip end portion of the rotary tool 16 is detachably attached to the attachment member 36 (can be exchanged). The axis X of the attached rotary tool 16 is on the extension of the axis of the spline shaft 25. An extendable bellows member 34 is disposed between the lower cover 23 and the lower end of the elevating cylinder 33 to protect the outer surface of the elevating cylinder 33 from contamination outside the main body case 13. .

  A bearing 25b is provided between the spline shaft 25 and the upper lid member 21, a bearing 35a is provided between the elevating cylinder 33 and the rotating cylinder 35, and a bearing is provided between the elevating cylinder 33 and the mounting member 36. 33a are provided.

  The pressing motor 14 is preferably a servo motor that can easily control and detect the rotation angle, and the rotating motor 15 can be a servo motor that can also easily control and detect the rotation angle, or can easily control the rotation speed. Induction mode is preferred. The pressing motor 14 and the rotating motor 15 constitute driving means for pressing the rotating tool 16 (specifically, the shoulder portion 16b and the pin portion 16c of the rotating tool 16 shown in FIG. 6) while rotating the workpiece. .

  FIG. 6 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, which is the lower end surface of the cylindrical body 16a (the contour is circular), and the axis X of the rotary tool 16. A pin portion 16c having a diameter smaller than that of the shoulder portion 16b and projecting by a predetermined length h from the shoulder portion 16b; and an annular recess 16d provided in the shoulder portion 16b around the pin portion 16c; It consists of In the present embodiment, the bottom surface of the annular recess 16d is inclined so that the amount of recess becomes smaller toward the outside in the radial direction, and the annular recess 16d has a conical shape centering on the axis X of the rotary tool 16. It is recessed. 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, an annular recess The inclination angle θ of the bottom surface of 16d with respect to the shoulder portion 16b is set to 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, the number of workpieces 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. 6 is suitable particularly when joining different kinds of metal members having different melting points.

  Next, the operation | movement at the time of the friction point joining of the friction point joining apparatus 1 is demonstrated.

  First, the raising / lowering operation | movement and rotation operation | movement of the rotary tool 16 are demonstrated. The direction of the axis X of the rotary tool 16 can be freely changed by the robot 40. However, for convenience of explanation, the operation in the direction in which the rotary tool 16 approaches the receiving tool 17 is lowered and the receiving tool 17 is moved downward. Movement away is called ascending.

  When the screw shaft 24 is driven to rotate in the direction A in FIG. 5 by the rotation of the pressing motor 14, the elevating body 30 is lowered by screwing with the screw portion 24 a and is installed in the elevating cylinder 33 in the elevating body 30. The rotary cylinder 35 and the rotary tool 16 attached to the lower end portion of the rotary cylinder 35 via the attachment member 36 are lowered together. Conversely, when the screw shaft 24 is rotationally driven in the direction B of FIG. 5 by the rotation of the pressing motor 14, the elevating body 30 is lifted by screwing with the screw portion 24a, and the rotary cylinder 35 and the rotary tool 16 are moved. Rise together. In this way, the pressing motor 14 moves the rotary tool 16 forward and backward in the direction of the axis X of the rotary tool 16 with respect to the workpiece positioned between the rotary tool 16 and the receiving member 17 as will be described later. It will be configured. Further, the pressing motor 14 is configured to press the rotary tool 16 against the workpiece, and the pressing force at the time of pressing can be changed by a current supplied to the pressing motor 14. It has become.

  Further, when the spline shaft 25 is driven to rotate in the direction C in FIG. 5 by the rotation of the motor 15 for rotation, the rotating cylinder 35 is connected to the spline portion 25a independently of the movement of the elevating body 30 as described above. The rotating tool 16 that rotates in the same C direction as the spline shaft 25 by spline coupling and is attached to the rotating cylinder 35 also rotates in the same C direction as the spline shaft 25 around the axis X of the rotating tool 16. In addition, the rotation motor 15 can change the rotation speed of the rotary tool 16 around the axis X by a current supplied to the rotation motor 15.

  Next, a workpiece joining operation that accompanies the lifting and lowering operation of the rotary tool 16 will be described.

  FIG. 7 is a schematic view when the first metal member W1 and the second metal member W2 are subjected to friction point welding. The first and second metal members W1 and W2 are members constituting, for example, the body of an automobile. Here, the first metal member W1 is made of an aluminum alloy material (aluminum alloy plate), and the second metal member W2 is a steel material. (Steel plate). Further, it is assumed that a galvanized layer Z (see FIG. 8) is applied to the surface of the second metal member W2 as a rust prevention measure.

  In order to perform the friction point joining of the first metal member W1 and the second metal member W2 by the friction point joining apparatus 1, first, as illustrated in FIG. 7, the joining portion between the first metal member W1 and the second metal member W2. The portions including the five joint portions P in the illustrated example are overlapped, and this work is gripped and fixed by gripping means (not shown).

  Subsequently, by the operation of the robot 40, the joining gun 10 is brought close to one of the plurality of joints P to be joined in the workpiece, and the rotary tool 16 is positioned on the first metal member W1 side of the joint P. The receiver 17 is positioned on the second metal member W2 side of the joint P. Next, the entire joining gun 10 is moved to the first metal member W1 side, and the tip of the receiving member 17 is brought into contact with the lower surface of the second metal member W2.

  Then, in a state where the tip of the receiving member 17 is in contact with the second metal member W2, the rotating tool 16 is pressed against and bonded to the first metal member W1 by the above-described lowering operation and rotating operation. Specifically, the joining process is set so as to sequentially perform the initial movement process, the first pressing process, the second pressing process, and the third pressing process.

  First, in the initial movement step, the rotary tool 16 is lowered and moved to the initial position that is the 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. 8, 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.

  Note that the pressure applied to the first metal member W1 of the rotary tool 16 is determined by the current value supplied to the pressing motor 14, and therefore the control unit 50a uses the current supplied to the pressing motor 14 as the first pressing step. Then, it controls so that it may become the electric current value corresponding to the said 1st pressurizing force during the said 1st predetermined time. Further, since the rotation speed of the rotary tool 16 is determined by the current value supplied to the rotation motor 15, the control unit 50a uses the current supplied to the rotation motor 15 as the first pressing step (and the initial movement step). Then, control is performed so that the current value corresponds to the first rotation speed.

  The moving resistance value is determined by the frictional resistance generated in the mechanism for moving the lifting cylinder 33 (rotary tool 16), which is constituted by the screw shaft 24, the lifting body 30, and the like. It is not stable and varies due to the influence of the gap amount, grease, etc. between the movable part and the fixed part. For this reason, when the first applied pressure is less than or equal to the movement resistance value, the time until the first applied pressure actually acts on the first metal member W1 varies depending on the magnitude of the movement resistance value, and the first metal member The time for actually pressing W1 with the first applied pressure varies considerably with respect to the first predetermined time. However, in this embodiment, since the first pressing force is set to be larger than the moving resistance value, the rotary tool 16 with the first pressing force immediately after the start of the first pressing step is performed regardless of the magnitude of the moving resistance value. The shoulder portion 16b and the pin portion 16c are pressed against the first metal member W1, and the time during which the first pressure force actually acts on the first metal member W1 is substantially the same as the first predetermined time, Stabilize.

  The first pressurizing force is preferably set to be greater than or equal to 2.45 kN and less than or equal to 3.43 kN than the maximum value of the variation range of the movement resistance value. The first rotation speed is preferably set to 1500 rpm or more and 3500 rpm or less. Further, the first predetermined time is preferably set to 0.2 seconds or more and 2.0 seconds or less. With respect to 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 deep axis X side) 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 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 (the part where the bottom surface of the annular recess 16d is not in contact), and eventually to the entire joint P. The whole part (joint part P) facing the shoulder part 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 joint 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. Thus, by making the pin part 16c of a thin diameter contact | abut first, the positioning of the rotary tool 16 is made favorable and rotational runout is suppressed effectively (anchor function).

  In the subsequent second pressing step, as shown in FIG. 9, 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). 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 flows in the vertical direction in the figure. Thus, it is possible to suppress the flow from the portion immediately below the rotary tool 16 (joint portion P) to the outside. In addition, the second pressurizing force is concentrated on the joint 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 joint P at the joint interface between the two metal members Wl and W2, so that the new surface of the second metal member W2 is exposed and is not shown in the drawings. When the oxide film formed on the surface of the first metal member W1 is broken at the joint P by the oxygen, the new surface of the first metal member W1 is exposed.

  The second applied pressure is preferably set to 3.92 kN or more and 5.88 kN or less. The second rotation speed is preferably set to 2000 rpm or more and less than 3000 rpm. Further, the second predetermined time is preferably set to 1.0 second or more and 2.0 seconds or less. The second 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.

  The end of the second pressing step may end the joining at the joint P, but in the present embodiment, the third pressing step is further performed.

  In the third pressing step, as shown in FIG. 10, while the rotary tool 16 is rotated at the third rotational speed by the rotation motor 15, the pressing motor 14 performs a third pressing force smaller than the second pressing force, 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 portion P is finished.

  The third pressure is preferably set to be 0.49 kN or more and 1.47 kN or less than the first pressure. The third rotation speed is preferably set to 1500 rpm or more and 3500 rpm or less. Furthermore, it is preferable that the third predetermined time is set to 0.5 seconds or more and 2.5 seconds or less. 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 joint P, and is oxidized. The coating is further destroyed, and the exposed range of the new surfaces of both metal members Wl and W2 is expanded (the range indicated by x in FIG. 10). As a result, the mating surface portions of both metal members are solid-phase bonded by friction point bonding, and the bonding strength is stably increased.

  In the vicinity of the joint P in the galvanized layer Z, a metal mixture layer Y of the metal of the first metal member W1 and the metal of the galvanized layer Z is generated.

  When the joining at the one joining portion P is completed, the rotary tool 16 is raised by rotating the screw shaft 24 in the direction B in FIG. The welding tool 18 is moved away from the work by being moved in the descending direction 16. In the joint P after the completion of the friction spot welding, as shown in FIG. 11, the marks of the shoulder portion 16b and the pin portion 16c remain on the surface of the workpiece (first metal member Wl), and the periphery of the shoulder portion 16b. Has a burr R.

  When the friction spot welding at the joint P is completed, the control unit 50 a moves the welding gun 10 to the next joint P by the robot 40. Then, the joining gun 10 is caused to repeatedly perform the same operation as described above, and the next joining portion P is joined. In this way, friction point joining (solid phase joining) is sequentially performed at the plurality of joining portions P.

  By the way, while repeating the friction spot welding at the plurality of joints P, as shown in FIG. 12, the adherend W1a may be generated around the shoulder portion 16b, particularly the pin portion 16c. The adhesion part W1a is softened at the time of joining, and the first metal member W1 plastically flowed adheres to the shoulder part 16b and is solidified. In particular, when the annular recess 16d is formed in the shoulder portion 16b, the adherend W1a is easily generated.

  When the adherend W1a is increased, the anchor function of the pin portion 16c in the first pressing step is lowered, and the rotational runout of the rotary tool 16 is increased. Therefore, there is a possibility that the bonding quality is deteriorated. In addition, there is a risk of damage to the rotary tool 16 and the driving mechanism of the joining gun 10 (for example, the bearing 25b, the bearing 35a, and the bearing 33a shown in FIG. 4) or the surrounding jigs.

  Therefore, in this embodiment, a rotary tool processing device 60 described below is provided to efficiently remove the adherend W1a at an appropriate timing. The rotary tool processing device 60 mainly includes an adhesion detection unit 70 (see FIG. 13) and an adhesion removal unit 80 (see FIG. 14). The rotary tool processing device 60 is provided within the movable range of the joining gun 10 by the robot 40. That is, the operation of the rotary tool 16 with respect to the rotary tool processing device 60 described below is configured to be performed by the operation of the robot 40 with the rotary tool 16 mounted on the joining gun 10.

  13A and 13B are diagrams showing the adhesion detection unit 70, where FIG. 13A is an overall configuration diagram, FIG. 13B is a detection operation diagram when there is almost no adhesion to the shoulder 16b, and FIG. 13C is the shoulder 16b. It is a detection operation figure in case the state of adhesion to is more than a predetermined value.

  As shown in FIG. 13A, the adhesion detection unit 70 includes a support column 61 extending vertically, a hinge pin 65 provided near the upper end of the support column 61 and having a horizontal axis, and a proximal end side swinging to the hinge pin 65. A steel plate detection plate 63 that is pivotally supported and has an upwardly bent portion 63a on the front end side, a receiving base 73 that supports the front end side of the detection plate 63 from below, and a support that extends vertically. A column 71 that supports the base 73, a sensor support portion 75 that is erected upward from the cradle 73, a laser displacement sensor 77 that is fixed near the upper end of the sensor support portion 75, and detection by the laser displacement sensor 77. And a cable 78 for transmitting a signal to the control unit 50a of the friction point welding apparatus 1.

  A through hole 67 is formed relatively close to the hinge pin 65 of the detection plate 63. The diameter of the through hole 67 is larger than the pin diameter D2 of the pin portion 16c by a predetermined value (for example, 1 mm).

  Since the detection plate 63 is swingable about the hinge pin 65, the tip side falls if the support 73 is not supported. The cradle 73 supports the detection plate 63 in order to prevent the fall, and is in a normal state (a state where the rotary tool 16 is sufficiently separated from the detection plate 63 as shown in FIG. 13A). Thus, the detection plate 63 is supported substantially horizontally.

  The detection plate 63 can swing in a direction in which the distal end side (the bent portion 63a) of the detection plate 63 is displaced upward from the normal state. When the bent portion 63a is displaced upward by the swing, the amount of movement in the vertical direction is referred to as the amount of displacement of the detection plate 63.

  The laser displacement sensor 77 is a known sensor and will not be described in detail. However, the laser displacement sensor 77 includes a laser light emitting part and a light receiving part, and receives the reflected light of the laser light emitted from the light emitting part. Is detected. In this embodiment, a laser displacement sensor 77 is used as a sensor for detecting whether or not the displacement amount of the detection plate 63 is equal to or greater than a predetermined determination threshold value. The light emitting portion of the laser displacement sensor 77 is set to emit laser light toward a space slightly above the upper end of the bent portion 63a when the displacement amount of the detection plate 63 = 0.

  Next, an adhesion state detection process and an adhesion state detection operation in the adhesion detection unit 70 will be described. For example, when a predetermined condition is satisfied, for example, when a predetermined number of friction spot weldings are performed, the control unit 50a executes the adhesion state detection step before executing the friction point welding at the next joint P. That is, the robot 40 and the joining gun 10 are caused to perform an adhesion state detection operation. In this adhesion state detection operation, as shown in FIG. 13A, the shoulder portion 16b of the rotary tool 16 faces upward, and the positions of the through hole 67 and the pin portion 16c of the detection plate 63 are aligned. This is an operation of bringing the rotary tool 16 closer to the detection plate 63 (arrow AW1). At this time, it is not necessary to rotate the rotary tool 16.

  FIG. 13B shows a state in which the rotary tool 16 having no adhesion to the shoulder portion 16b is moved to the detection position. This detection position is a position where the shoulder portion 16b substantially contacts (soft contact) with the detection plate 63. Teaching that causes the robot 40 (the control unit 50a) to recognize the detection position may be performed in advance using the rotary tool 16 without adhesion.

  If there is no adhesion in the shoulder portion 16b or if there is only a slight adhesion state, the pin portion 16c protruding from the shoulder portion 16b is completely fitted into the through hole 67. Therefore, as shown in FIG. 13B, the detection plate 63 is not displaced (displacement amount = 0).

  As shown in FIG. 13B, when the displacement amount of the detection plate 63 is 0, the laser beam 79 emitted from the light emitting portion of the laser displacement sensor 77 does not hit the bent portion 63a, and the light receiving portion is the bent portion. The reflected light from 63a is not received. At this time, no adhesion detection signal is sent from the laser displacement sensor 77 to the control unit 50a (an adhesion non-detection signal may be sent via the cable 78).

  FIG.13 (c) shows the case where the adhesion thing W1a exists around the pin part 16c of the shoulder part 16b. When the amount of adhered material W1a exceeds a certain level (size), when the rotary tool 16 is moved to the detection position, the adhered material W1a is obstructed and does not fit into the pin portion 16c or the through hole 67 completely. Then, the adherend W1a pushes up the detection plate 63. Then, the detection plate 63 swings around the hinge pin 65 and is displaced. The greater the adhesion state, that is, the greater the amount of the adhered material W1a, the greater the displacement of the detection plate 63.

  FIG. 13C shows a state in which the displacement amount = h1 and h1> the determination threshold value. When the displacement amount h1 exceeds a determination threshold (for example, about 6 mm), the laser light 79 from the laser displacement sensor 77 strikes the bent portion 63a and the reflected light is received by the light receiving portion. At this time, an adhesion detection signal is sent from the laser displacement sensor 77 to the control unit 50a via the cable 78.

  As described above, the adhesion detection unit 70 can easily detect the adhesion state by converting the adhesion state on the shoulder portion 16 b into the displacement amount of the detection plate 63.

  In addition, what is necessary is just to adjust the length (height) of the bending part 63a, the height of the sensor support part 75, the installation angle of the laser displacement sensor 77, etc. in order to change the said determination threshold value. Then, the relationship between the adhesion state and the displacement amount of the detection plate 63 is sampled in advance, and the determination threshold value may be set as appropriate within the range of the displacement amount in the adhesion state where no actual harm occurs.

  By the way, as shown in FIG. 13A, when the distance between the hinge pin 65 and the through hole 67 is L1, and the distance between the hinge pin 65 and the bent portion 63a is L2, the distance L1 <the distance L2. For this reason, the displacement amount of the detection plate 63 becomes larger than the push-up amount of the detection plate 63 by the adherend W1a. That is, the adhesion detection unit 70 has an amplifying function for amplifying and detecting the adhesion state. The amplification factor K is K = L2 / L1. The greater the amplification factor K, the higher the accuracy of detecting the adhesion state. Further, if the amplification factor K is reduced, the adhesion detector 70 can be reduced in size. An appropriate amplification factor K may be set in consideration of the balance.

  Next, the adhesion removing unit 80 of the rotary tool processing device 60 will be described. 14A and 14B are diagrams showing the adhesion removing unit 80, where FIG. 14A is an overall configuration diagram, FIG. 14B is an operation diagram during the adhesion removal operation, and FIG. 14C is an operation diagram after the adhesion removal operation. . The adhesion removal unit 80 removes the adhesion W1a adhered to the shoulder portion 16b of the rotary tool 16 when an adhesion detection signal is sent from the laser displacement sensor 77 to the control unit 50a in the adhesion detection unit 70. Is provided.

  As shown in FIG. 14A, the adhesion removing unit 80 includes a support column 81 that extends vertically, a pedestal 82 that is provided near the upper end of the support column 81 and extends in the horizontal direction, and is further upward from the vicinity of the upper end of the support column 81. An arm support portion 83 standing upright, a rotation shaft 86 provided near the upper end of the arm support portion 83, having a substantially horizontal axis, and being supported by the rotation shaft 86 and extending in a substantially horizontal direction, The arm 85 that is rotatable around the rotation shaft 86, the pressing portion 87 that is fixed to one end of the arm 85 and is provided at a position facing the cradle 82, and the rotation shaft 86 of the arm 85 are sandwiched. The hydraulic cylinder 84 which connects the edge part on the opposite side to the press part 87, and the support | pillar 81 is provided, and the process 1st metal member W3 clamped by the receiving stand 82 and the press part 87 is provided.

  The processing first metal member W3 (processing metal member) is a plate made of the same material as the first metal member W1, that is, a plate made of an aluminum alloy material. The thickness is, for example, about 2 mm.

  The axis of the hydraulic cylinder 84 extends in the vertical direction, and the tip of the movable shaft 84 a is connected to the end of the arm 85. Therefore, the arm 85 can be rotated around the rotation shaft 86 by expanding and contracting the movable shaft 84a. Alternatively, it can be pushed and pulled in the rotating direction.

  As shown in FIG. 14A, in the setting state where the first metal member W3 for processing is sandwiched between the cradle 82 and the pressing portion 87, by applying a pressing force in the direction of extending the movable shaft 84a, A downward pressing force acts on the pressing portion 87 via the arm 85. The first metal member W3 for processing is securely fixed by this applied pressure.

  Further, by applying a force in the direction in which the movable shaft 84 a is contracted, an upward force is applied to the pressing portion 87 via the arm 85. As a result, the fixed state of the processing first metal member W3 is released, and it is possible to remove and replace the first metal member W3.

  Next, the agglomerated substance removing process and the agglomerated substance removing operation in the agglomerated substance removing unit 80 will be described. In the adhesion detection process, when an adhesion detection signal is sent from the laser displacement sensor 77 to the control unit 50a, the control unit 50a executes an adhesion removal process. That is, the robot 40 and the bonding gun 10 are caused to perform the adhesion removal operation.

  As shown in FIG. 14 (a), the adhered material removing operation is performed by positioning the rotary tool 16 opposite to the processing first metal member W3 by the robot 40, and then pressing the rotary tool 16 as shown in FIG. 14 (b). In this operation, the shoulder portion 16b and the pin portion 16c are pressed against the first metal member W3 for processing while the rotary tool 16 is rotated by the motor 14 for rotation and the motor 15 for rotation, and the adhered material is removed. This operation is performed by storing the operation in the control unit 50a in advance by teaching.

  The adhesion removal operation is similar to the operation of joining the workpieces at the friction point, but does not join the workpieces, and is also called discarding. For example, it is preferable to set the discarding condition to a pressure of about 3.43 kN, a rotational speed of about 2500 rpm, and a predetermined time of about 1.5 seconds.

  When thrown away, the adherend W1a and the first metal member for processing W3 are softened to cause plastic flow. Then, solid phase bonding occurs between the two, and bonding occurs. That is, the adherend W1a is transferred to the processing first metal member W3.

  Thereafter, when the rotary tool 16 and the receiving member 17 are separated from the processing first metal member W3, the adherend W1a remains on the processing first metal member W3 as shown in FIG. 14C. That is, the adherend W1a is easily removed from the shoulder portion 16b without damaging the rotary tool 16.

  In the present embodiment, discarding is performed twice per one agglomerate removal step, and the agglomerate W1a is more reliably removed.

  FIG. 15 is a flowchart of friction point joining including an adhesion state detection step and an adhesion removal step. When this flowchart starts in the control unit 50a, first, 0 is input to the joining counter F (step S10). Next, in the first joint P, friction point joining is performed from the initial movement process to the third pressing process through the first pressing process and the second pressing process (step S12). Next, it is determined whether or not the joining has been completed in all the joining portions P (step S14). If NO, 1 is added to the joining counter F (step S16). Next, it is determined whether or not the value of the bonding counter F has reached the predetermined number N1 (step S18). The predetermined number of times N1 is a value set in advance, and is a value for executing the adhesion state detection step every N1 times of joining. If it is determined NO in step S18 and the value of the joining counter F has not reached the predetermined number N1, the process proceeds to step S12, and the friction point joining is repeated at the next joining portion P.

  And when it determines with YES by step S18 and the value of the joining counter F reaches predetermined times N1, it transfers to step S20 and performs the said adhesion state detection process in the adhesion detection part 70. FIG. When the adhesion detection signal is not sent from the laser displacement sensor 77 in step S20 and it is determined that there is no adhesion (not an adhesion state of a predetermined value or more) (NO in step S22), the process returns to step S10, and the bonding counter F is reset to 0 and bonding is repeated. In this way, even after the predetermined number of times of joining N1 times, if the adhesion state has not reached the predetermined value, the unnecessary adhering substance removing step can be omitted by continuously repeating the joining. It is possible to improve efficiency.

  On the other hand, when an adhesion detection signal is sent from the laser displacement sensor 77 in step S20 and it is determined that there is adhesion (the adhesion state is equal to or greater than a predetermined value) (YES in step S22), the adhesion removal unit 80 The agglomerate removing step is executed (step S24). Then, it returns to step S10, resets the joining counter F to 0, and joining is repeated anew.

  Going back, when it is determined in step S14 that the joining at all the joints P has been completed (YES), an agglomerate removing process is executed in preparation for the next operation (step S30). Then, the rotary tool 16 is brought into a state where the adherend W1a has been removed, and the process ends.

  As mentioned above, although embodiment of this invention was described, this invention is not limited to the said embodiment, It can change suitably in a claim.

  For example, the first metal member W1 and the second metal member W2 do not have to be a combination as in the above embodiment, and may be a combination of other metal materials (including the same kind of metals). The first metal member W3 for processing is desirably the same type of metal as the first metal member W1, but this is not necessarily the case.

  Further, the shape of the shoulder portion 16b of the rotary tool 16 does not have to be formed with the annular recess 16d. Since the one formed with the annular recess 16d tends to cause adhesion, the effect of the present invention is remarkably exhibited. However, other shapes, for example, the shoulder portion 16b is a flat surface perpendicular to the axis X. In addition, the effects of the present invention relating to the detection and removal of adhesion can be achieved.

  The rotary tool 16 or the joining gun 10 may not be mounted on the robot 40. However, when the rotary tool 16 and the joining gun 10 are mounted on the robot 40, there is an advantage that the adhesion state detection process and the adhesion removal process can be easily performed using the high degree of freedom of movement. . In addition, there is an advantage that these operations can be appropriately incorporated between the friction point joining operations of the workpieces so that the entire operation can be performed efficiently.

  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.

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 side view of the joining gun shown in FIG. It is sectional drawing which shows the internal structure of the main body case shown in FIG. It is the VV sectional view taken on the line of FIG. It is an enlarged view of the front-end | tip part of the rotary tool shown in FIG. It is the schematic at the time of carrying out friction point joining of the 1st metal member and the 2nd metal member. It is explanatory drawing of the 1st press process in friction point joining. It is explanatory drawing of the 2nd press process in friction point joining. It is explanatory drawing of the 3rd press process in friction point joining. It is a figure which shows the state after completion of friction point joining. It is a figure which shows the adhesion state of the adhesion thing in the shoulder part of a rotary tool. It is a figure which shows the adhesion detection part which is a part of rotary tool processing apparatus, (a) is a whole block diagram, (b) is a detection operation figure when there is almost no adhesion to a shoulder part, (c) is a figure. It is a detection operation | movement figure in case the adhesion state to a shoulder part is more than predetermined value. It is a figure which shows the adhesion removal part which is a part of rotary tool processing apparatus, (a) is a whole block diagram, (b) is an operation | movement figure during adhesion removal operation | movement, (c) is after adhesion removal operation | movement. FIG. It is a flowchart of friction point joining including an adhesion state detection process and an adhesion thing removal process.

Explanation of symbols

14 Pressing motor (drive means)
15 Motor for rotation (drive means)
16 Rotating tool 16b Shoulder portion 16c Pin portion 16d Annular recess 50a Control unit (control means)
60 Rotating Tool Processing Device 63 Detection Plate 70 Adhesion Detection Unit (Detection Means)
77 Laser displacement sensor (displacement sensor)
W1 First metal member (metal member)
w1a Adhesive W2 Second metal member (metal member)
W3 1st metal member for processing (metal member for processing)

Claims (5)

A plurality of metal members are superposed, the pin part and the shoulder part are pressed against the metal member while rotating a rotary tool provided with a pin part protruding from the shoulder part, the metal member is softened by frictional heat, and plastic It is a rotary tool processing method of a friction point joining apparatus that causes flow and causes the metal members to be spot-joined,
An adhesion state detection step of detecting an adhesion state of the metal member to the shoulder portion by a detection means after performing at least one joining;
In the adhesion state detection step, including an adherent removal step that is executed when the adhesion state is detected to be a predetermined value or more,
In the adhesion point removing step, the rotating tool of the friction point joining apparatus is characterized in that the adhesion part is removed by pressing the pin part and the shoulder part against the processing metal member while rotating the rotary tool. Processing method. A plurality of metal members are superposed, the pin part and the shoulder part are pressed against the metal member while rotating a rotary tool provided with a pin part protruding from the shoulder part, the metal member is softened by frictional heat, and plastic It is a rotary tool processing device of a friction point joining device that causes flow to cause spot joining of the metal members,
Driving means for pressing the pin part and the shoulder part against the metal member while rotating the rotary tool;
A moving means comprising the rotating tool and the driving means, and moving the rotating tool to a joining position;
Detecting means for detecting the adhesion state of the metal member to the shoulder portion after performing at least one joining;
When the detection signal from the detection means indicates that the adhesion state is equal to or greater than a predetermined value, the moving means positions the rotary tool opposite the processing metal member, and the driving means causes the rotary tool to move. A rotating tool process for a friction point joining apparatus, comprising: a control means for performing an adhesion removal operation for removing the adhesion by pressing the pin part and the shoulder part against the metal member for processing while rotating. apparatus. The detection means includes a detection plate disposed so as to be substantially in contact with the shoulder portion;
A displacement sensor for detecting a displacement amount of the detection plate when the shoulder portion is substantially in contact with the detection plate;
The detection plate is configured to be displaced by a displacement amount corresponding to an adhesion state of the metal member to the shoulder portion when the shoulder portion is substantially brought into contact with the detection plate. The rotary tool processing apparatus for a friction point welding apparatus according to claim 2.   The rotary tool processing device for a friction point welding device according to claim 2 or 3, wherein the shoulder portion is formed with an annular recess surrounding the pin portion.   The rotary tool processing apparatus for a friction point welding apparatus according to any one of claims 2 to 4, wherein the moving means is a robot.

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