JP2013123746A - Friction stir welding device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a friction stir welding device which can easily and securely perform the friction stir welding of a fillet at a position along the join line of workpieces.SOLUTION: A main axis positioning mechanism 1 is formed from an X-axis table 5, holding workpieces 3a and 3b for fillet joining, and the Z-axis table 8 and Y-axis table 9 between a portal frame 6 and a main axis unit 7. The main axis unit 7 includes a friction stir welding tool 38 composed of a rotationally drivable probe 39 and a stationary type shoulder 40 whose lower edge part is made into a V shape by two workpiece contact faces. A load cell 44 is installed between the nut member 36 of the ball screw direct acting mechanism 31 of the Y-axis table 9 and a Y-axis table body 30. When friction stir welding is performed, the change of the contact pressure between the stationary type shoulder 40 and the workpieces 3a, 3b detected by the load cell 44 is monitored by a controller 45, a command is given to the servo motor 35 of the Y-axis table 9 so that a changed amount is made into zero when the contact pressure is changed, and the positional relation between the stationary type shoulder 40 and the workpieces 3a, 3b is held unchanged.

Description

  The present invention relates to a friction stir welding apparatus used for friction stir welding of fillet.

  In friction stir welding, the probe (rod-like protrusion, pin) equipped on the friction stir welding tool is pressed against the workpiece joint while rotating and immersed in the workpiece, and friction heat is generated at the workpiece joint. In this method, the joint is softened and a plastic flow region of the workpiece material is formed around the probe by the rotational force of the probe, and agitated and mixed to integrally join a plurality of workpieces. Such friction stir welding has been used mainly for joining thin aluminum alloy materials (less than 10 mm) with a small joining reaction force generated during friction stir welding.

  The friction stir welding tool used for friction stir welding is integrated with a shoulder for contacting the surface of the workpiece in the vicinity of the workpiece with a larger diameter than the probe on the proximal end side of the probe for immersing the workpiece in the joint. The type provided in was mainly used.

  The friction stir welding apparatus using the friction stir welding tool includes a spindle unit provided with the friction stir welding tool so as to be rotationally driven, a workpiece to be joined, an X axis direction that is a direction along a workpiece joining line, and a vertical direction. Since it is necessary to control the relative position between the Z-axis direction and the Y-axis direction, which is the horizontal direction orthogonal to the X-axis direction, the apparatus configuration is generally like a three-axis portal machine. .

  By the way, in the friction stir welding apparatus, when the friction stir welding is performed by moving the work in the X-axis direction (relatively moving the work and the friction stir welding tool in the X-axis direction), If the position of the joining line of the workpiece is displaced in the Y-axis direction, or the joining line is inclined from the X-axis direction in the plane of the workpiece, the position of the friction stir welding tool is It is relatively displaced from the workpiece joining line, resulting in poor bonding.

  Therefore, when performing the friction stir welding by the friction stir welding apparatus, the workpiece is accurately measured so that the position and the inclination of the joining line of the workpiece do not deviate from the X axis direction that is the traveling direction of the workpiece. It is necessary to perform positioning.

  However, when the work is very long, such as a ship interior material (Longi), which is several m to 20 m, the work advancing direction and the position of the joining line over the entire length of the work. It is very difficult to adjust the inclination accurately.

  Therefore, for example, in a friction stir welding apparatus that can control the position of the friction stir welding tool in the X, Y, and Z directions with a servo motor, the workpiece joining line in the forward direction of the friction stirring welding tool is photographed, and the workpiece joining line in the photographed image is captured. It has been conventionally proposed to calculate the amount of deviation from the reference position and to control the position of the friction stir welding tool with respect to the workpiece joining line by feedback control based on the amount of deviation (for example, , See Patent Document 1).

  By the way, although friction stir welding was originally applied when the joint part of a workpiece | work was flat, applying friction stir welding about the joining of the fillet of a workpiece | work has been proposed in recent years (for example, patent) Reference 2).

JP 2002-1550 A Japanese Patent No. 4240579

  However, in the method of applying friction stir welding to the joining of the fillet of the workpiece, when the workpiece is long, it is necessary to accurately match the traveling direction of the workpiece with the position and inclination of the joining line over the entire length of the workpiece. Although the problem that it is difficult arises, Patent Document 2 does not show any countermeasures.

  The method of controlling the friction stir welding shown in the above-mentioned Patent Document 1 needs to detect the position of the joining line of the workpiece by image analysis, and thus requires a camera and an image analysis device, which increases costs. There is. In addition, since the location where the position of the welding line of the workpiece is detected does not coincide with the location where the friction stir welding is performed by the friction stir welding tool, it is difficult to improve the accuracy of the copying control and malfunction. There is also a possibility.

  Therefore, in the present invention, when the friction stir welding of the fillet of the workpiece is performed, the position of the welding line of the workpiece and the inclination in the horizontal plane are shifted with respect to the relative movement direction of the friction stir welding tool and the workpiece. Even if it occurs, an object of the present invention is to provide a friction stir welding apparatus capable of easily and reliably performing fillet friction stir welding at a position along the joining line of the workpiece.

  In order to solve the above-described problems, the present invention provides a friction stir welding apparatus having a friction stir welding tool including a probe that can be driven to rotate and a fixed shoulder. Is provided with a V-shaped lower end portion by two workpiece contact surfaces for bringing the workpiece into contact with the surface sandwiching the joining line of workpieces to be joined, and the friction stir welding tool is friction stir A transverse axis for enabling movement in a horizontal direction perpendicular to the relative movement direction with respect to the workpieces during construction, and means for detecting contact pressure in a direction parallel to the transverse axis with respect to the workpieces of the fixed shoulder And a controller for giving a command for controlling the position of the friction stir welding tool to the transverse axis in accordance with a detected value of the contact pressure by the detecting means. And friction stir welding apparatus having a.

  In the above configuration, the controller monitors the detection value of the contact pressure input from the detection means, and the difference between the input detection value and the initial value of the detection value at the start of friction stir welding is zero. Thus, the transverse axis is provided with a function of performing load feedback control of the position of the friction stir welding tool.

According to the friction stir welding apparatus of the present invention, the following excellent effects are exhibited.
(1) In a friction stir welding apparatus having a friction stir welding tool provided with a probe that can be rotated and a fixed shoulder, the fixed shoulder is placed on a surface sandwiching a joining line of a workpiece to be joined to fillet. A horizontal direction perpendicular to the relative movement direction of the friction stir welding tool to the workpiece during construction of the friction stir welding is provided with a V-shaped lower end portion by two work contact surfaces for contact. A traverse axis for enabling movement to a position, means for detecting a contact pressure in a direction parallel to the traverse axis with respect to the work of the fixed shoulder, and the traverse according to a detected value of the contact pressure by the detection means And a controller for giving a command to control the position of the friction stir welding tool to the shaft. Even if there is a displacement or inclination in the relative movement direction of the friction stir welding tool and the workpiece during friction stir welding, the probe of the friction stir welding tool is copied to the workpiece joining line. Can be moved. Therefore, the friction stir welding at the position of the joining line of the workpiece can be carried out satisfactorily without performing precise positioning of the workpiece.
(2) Thereby, even when the workpiece is long, the friction stir welding of the workpiece can be easily performed.
(3) Furthermore, since the construction conditions for friction stir welding are stable, the quality of products manufactured by friction stir welding can be improved.

It is a schematic front view which shows one Embodiment of the friction stir welding apparatus of this invention. It is a schematic side view of the friction stir welding apparatus of FIG. The friction stir welding tool of the friction stir welding apparatus of FIG. 1 is enlarged and shown, (a) is a front view, (b) is a side view. It is a schematic side view which expands and shows the attachment location of the load cell in the friction stir welding apparatus of FIG.

  Hereinafter, embodiments for carrying out the present invention will be described with reference to the drawings.

  1 to 4 show an embodiment of a friction stir welding apparatus according to the present invention, and show an example of a type having a triaxial gate type main spindle positioning mechanism.

  Here, first, the three-axis portal type spindle positioning mechanism will be described.

  As shown by reference numeral 1 in FIGS. 1 and 2, the three-axis portal type spindle positioning mechanism places workpieces 3a and 3b on which a fillet is to be joined on a horizontal base 2, and the workpiece 3a And an X axis table 5 for moving along the extending direction of the joint line 4 (see FIGS. 3A and 3B).

  Further, the spindle positioning mechanism 1 includes a portal frame 6 straddling the X-axis table 5, and a spindle unit 7 disposed above the X-axis table 5 is disposed on the portal frame 6. A Z-axis table 8 for controlling the position in the vertical direction (Z-axis direction) and a horizontal direction (hereinafter referred to as Y-axis direction) orthogonal to the moving direction of the X-axis table 5 (hereinafter referred to as X-axis direction). ) Is attached via a Y-axis table 9 as a transverse axis for controlling the position.

  The X-axis table 5 includes a guide rail 10 provided on the gantry 2 so as to extend in the X-axis direction, and an X-axis that is slidably attached to the guide rail 10 via a guide block 11 as a horizontal flat plate shape. A table main body 12 and a ball screw linear motion mechanism 13 as a linear motion mechanism in the X-axis direction provided between the gantry 2 and the X-axis table main body 12 are configured.

  The ball screw linear motion mechanism 13 includes a screw shaft 15 disposed in parallel with the guide rail 10, a bearing member 14 that rotatably supports both ends of the screw shaft 15 in the axial direction of the screw shaft 15; The speed reducer 16 is connected to one end of the screw shaft 15 in the axial direction, the servo motor 17 is connected to the speed reducer 16, and the nut member 18 is attached to the middle portion of the screw shaft 15. The nut member 18 is attached to the X-axis table main body 12 via a bracket 12a.

  Thereby, the X-axis table 5 moves the X-axis table main body 12 together with the nut member 18 in the X-axis direction by the rotational drive of the screw shaft 15 via the speed reducer 16 by the servo motor 17. You can make it. At this time, in the X-axis table 5, a detection signal of the rotation amount of the servo motor 17 or a position detection means such as a linear gauge or a displacement sensor detects the position of the nut member 18 or the X-axis table body 12. Based on the signal, as will be described later, the position and moving speed of the workpieces 3a and 3b to be placed and held on the upper side of the X-axis table main body 12 can be controlled.

  The Z-axis table 8 includes a guide rail 19 in the vertical direction (Z-axis direction) installed on the portal frame 6 and a guide block 20 on the guide rail 19 as a flat plate shape along a vertical plane perpendicular to the X-axis direction. A Z-axis table main body 21 slidably mounted via a Z-axis table, and a ball screw linear motion mechanism 22 as a Z-axis direction linear motion mechanism provided between the portal frame 6 and the Z-axis table main body 21. ing.

  The ball screw linear motion mechanism 22 includes a screw shaft 24 arranged in parallel with the guide rail 19, and a bearing member 23 that rotatably supports both ends of the screw shaft 24 in the axial direction on the portal frame 6. A speed reducer 25 connected to the upper end of the screw shaft 24 in the axial direction, a servo motor 26 connected to the speed reducer 25, and a nut member 27 attached to an intermediate portion of the screw shaft 24. It is composed of The nut member 27 is attached to the Z-axis table main body 21 via a bracket 21a.

  As a result, the Z-axis table 8 moves the Z-axis table main body 21 together with the nut member 27 in the vertical direction by rotating the screw shaft 24 via the speed reducer 25 by the servo motor 26. It can be moved in the direction. At this time, the Z-axis table 8 detects the rotation amount of the servo motor 26 or the position of the nut member 27 or the Z-axis table main body 21 by position detection means (not shown) such as a linear gauge or a displacement sensor. Based on the signal, the position (height position) in the Z-axis direction of the spindle unit 7 held by the Z-axis table body 21 via the Y-axis table 9 can be controlled as will be described later.

  The Y-axis table 9 has a guide rail 28 in the Y-axis direction installed on the Z-axis table main body 21 and a flat plate shape along a vertical plane perpendicular to the X-axis direction via the guide block 29 to the guide rail 28. A Y-axis table main body 30 that is slidably mounted, and a ball screw linear motion mechanism 31 as a linear motion mechanism in the Y-axis direction provided between the Z-axis table main body 21 and the Y-axis table main body 30 are configured. .

  The ball screw linear motion mechanism 31 includes a screw shaft 33 arranged in parallel with the guide rail 28 and a bearing member 32 that rotatably supports both end portions of the screw shaft 33 in the axial direction on the Z-axis table main body 21. A reduction gear 34 connected to one end of the screw shaft 33 in the axial direction, a servo motor 35 connected to the reduction gear 34, and a nut member as a driven member attached to an intermediate portion of the screw shaft 33 36. The nut member 36 is attached to the Y-axis table main body 30 via a bracket 30a.

  Thereby, the Y-axis table 9 moves the Y-axis table body 30 in the Y-axis direction together with the nut member 36 by the rotational drive of the screw shaft 33 via the speed reducer 34 by the servo motor 35. You can make it. At this time, the Y-axis table 9 detects the position of the nut member 36 or the Y-axis table main body 30 by a detection signal of the rotation amount of the servo motor 35 or position detection means (not shown) such as a linear gauge or a displacement sensor. Based on the signal, the position in the Y-axis direction of the spindle unit 7 attached to the Y-axis table main body 30 can be controlled.

  The friction stir welding apparatus of the present invention further includes a jig 37 on the upper side of the X-axis table main body 12 for holding the workpieces 3a and 3b to be joined with fillets. As shown in FIG. 3 (a), the jig 37 has a posture in which the surfaces of the workpieces 3a and 3b, which are arranged with the joint line 4 interposed therebetween, are inclined surfaces. That is, the joint portion of the fillets of the workpieces 3a and 3b can be held in a V-shaped posture opened upward. The jig 37 has the workpieces 3a and 3b arranged in such a manner that the longitudinal direction of the joining line 4 is along the operation direction of the X-axis table 5, and the length of the joining line 4 in the workpieces 3a and 3b. It is assumed that a plurality of directions can be held. The workpieces 3a and 3b are held by the jig 37 so that a friction stir welding tool 38, which will be described later, is inserted into the joint between the workpieces 3a and 3b, and a probe 39 is inserted into the joint line 4 in order to perform friction stir welding. It is assumed that the workpieces 3a and 3b can be held so as not to be displaced even if they are pressed with such a large force that they can be applied.

  3A illustrates the case where the fillet joints of the workpieces 3a and 3b are square joints, the fillet joint may be a T-shaped joint, a lap joint, or a cross joint. . In these cases, the workpieces 3a and 3b are arranged in accordance with the postures when the workpieces 3a and 3b are arranged so that the surfaces of the workpieces 3a and 3b arranged on both sides of the joining line 4 are inclined surfaces. You may change suitably the shape of the said jig | tool 37 to hold | maintain.

  Further, as shown in FIG. 3 (a), the jig 37 has the workpieces 3a and 3b to be joined to fillet, and the surfaces of the workpieces 3a and 3b arranged with the workpiece joining line 4 interposed therebetween are vertical. It is preferable to be able to hold the workpieces 3a and 3b in a posture having an equal inclination angle from the direction. However, depending on the shape and arrangement of the joint for joining the workpieces 3a and 3b to the fillet, the jig 37 has the surfaces of the workpieces 3a and 3b arranged with the workpiece joining line 4 sandwiched at different angles from the vertical direction. Of course, it is good also as a form hold | maintained so that it may become an inclined surface.

  As shown in FIGS. 3 (a) and 3 (b), a friction stir welding tool 38 having a rotatable drive probe 39 and a fixed (non-rotating) shoulder 40 is provided at the lower end of the spindle unit 7. Equipped.

  The probe 39 is arranged such that the axial direction is the vertical direction, and a rotational drive shaft (probe shaft) 41 is connected to the upper end serving as the base end of the probe 39. The rotation drive shaft 41 is connected to a rotation drive device (not shown) provided in the spindle unit 7 so as to transmit a rotation drive force to the probe 39.

  The fixed shoulder 40 has a lower end portion extending in the X-axis direction as a V-shape composed of two workpiece contact surfaces 42a and 42b. The workpiece contact surfaces 42a and 42b are provided with inclination angles respectively along the surfaces of the workpieces 3a and 3b held by the jig 37 on the X-axis table 5.

  Furthermore, the fixed shoulder 40 has a configuration in which a probe insertion hole 43 is provided in an intermediate portion in the longitudinal direction (X-axis direction) so as to penetrate in the vertical direction, and the probe insertion hole 43 is rotated and driven. As the state where the shaft 41 is inserted and arranged so that the probe 39 protrudes downward from the probe insertion hole 43, the upper end side of the fixed shoulder 40 is rotated to the lower end portion of the spindle unit 7. It is made to hold in the blocked state.

  As a result, the spindle unit 7 has the workpiece contact surfaces 42a and 42b of the fixed shoulder 40 of the friction stir welding tool 38 and the workpiece 3a held on the X-axis table 5 via the jig 37. The fixed shoulder 40 arranged so as to be pressed against the surfaces arranged with the joint line 4 of 3b pressed against each other, and the fixed shoulder 40 arranged in this manner protrudes below the fixed shoulder 40. The probe 39 is arranged at a position along the joining line 4 of the workpieces 3a and 3b to be joined to fillet.

  Further, as shown in FIG. 1, the friction stir welding apparatus of the present invention includes a detection means 44 for detecting the contact pressure in the Y-axis direction with respect to the workpieces 3a and 3b of the fixed shoulder 40, and the detection means 44. In response to the detected value of the contact pressure in the Y-axis direction, a command is given to the ball screw linear motion mechanism 31 that is the linear motion mechanism in the Y-axis direction of the Y-axis table 9, and the Y-axis table of the Y-axis table 9 A controller 45 is provided that gives a command for controlling the position of the friction stir welding tool 38 of the spindle unit 7 attached to the main body 30 in the Y-axis direction.

  The detection means 44 is, for example, a load cell 44 interposed between the nut member 36 that is a driven member in the ball screw linear motion mechanism 31 that is the linear motion mechanism in the Y-axis direction and the Y-axis table main body 30. (For convenience of explanation, the same reference numerals as those of the detection means 44 are given).

  The load cell 44 can detect an increase / decrease in pressure, that is, an increase / decrease in load load, in one direction along the Y-axis direction acting between the nut member 36 and the Y-axis table main body 30, for example, as shown in FIG. 4. As shown in FIG. 5, the nut member 36 and the Y-axis table main body 30 are integrated with the load cell 44 for detecting the compressive load in a state in which a pre-tension of a certain ratio within the load detection range of the load cell 44 is applied by the spring 46. The bracket 30a is interposed. The pretension applied to the load cell 44 may be about 30% to 50% of the load detection range.

  Alternatively, although not shown, when the load cell 44 is of a type that detects a compressive load, the load cell 44 is disposed in a pair on both sides of the nut member 36 in the Y-axis direction, and the nut member 36 is You may make it connect with the Y-axis table main body 30 via the load cell 44. FIG. Furthermore, when the load cell 44 is of a type that can detect a compression load and a tensile load, the load cell 44 may be directly interposed between the nut member 36 and the Y-axis table main body 30.

  When the controller 45 performs friction stir welding, the controller 45 monitors the detected value of the load applied in one direction along the Y-axis direction input from the load cell 44 so that the load is constant. A control command is given to the servo motor 35 of the Y-axis table 9.

  That is, as shown in FIGS. 1 and 3A, the friction stir welding tool 38 of the spindle unit 7 is cured on the X-axis table 5 by the Z-axis table 8 and the Y-axis table 9 in the spindle positioning mechanism 1. Arranged according to the positions of the workpieces 3a and 3b held via the tool 37, the workpiece contact surfaces 42a and 42b of the fixed shoulder 40 are arranged across the joining line 4 of the workpieces 3a and 3b. The probe 39 pressed and contacted with the corresponding surface and rotated is started to be immersed in the position of the joint line 4 between the workpieces 3a and 3b.

  With this state as the initial state, the controller 45 sets the load load value in one direction in the Y-axis direction detected by the load cell 44, for example, a load load with the right direction in FIGS. 1 and 3A as positive. Is stored as an initial value.

  In the state where the friction stir welding of the workpieces 3a and 3b is started as described above, the position of the joining line 4 of the workpieces 3a and 3b is one direction in the Y-axis direction (the right direction in FIGS. 1 and 3A). ), The surface of the workpiece 3a is more strongly pressed against the workpiece contact surface 42a side in the fixed shoulder 40. Therefore, the fixed shoulder 40 is pushed in one direction in the Y-axis direction by the work 3a, and accordingly, between the spindle unit 7 and the nut member 36 of the ball screw linear motion mechanism 31. In the load cell 44 that is interposed, the load in one direction in the Y-axis direction increases from the initial value.

  Therefore, when the detected value of the load load in one direction of the Y axis of the monitored load cell 44 increases, the controller 45 moves the nut member 36 to the servo motor 35 of the Y axis table 9 to the Y axis. A control command is given so as to move in one direction. Thereby, as the nut member 36 moves in one direction in the Y-axis direction, the position of the fixed shoulder 40 of the friction stir welding tool 38 of the spindle unit 7 together with the Y-axis table main body 30 is It is displaced in one direction in the Y-axis direction. For this reason, the increase from the said initial value of the load load of the one direction of the said Y-axis comes to be eliminated.

  On the other hand, if the position of the joint line 4 between the workpieces 3a and 3b is shifted in the other direction in the Y-axis direction (the left direction in FIGS. 1 and 3A), the fixed shoulder 40 has the workpiece contact surface 42b side. In addition, the surface of the workpiece 3b is pressed more strongly. Therefore, the fixed shoulder 40 is pushed in the other direction of the Y-axis by the work 3b. Accordingly, in the load cell 44, the load load in one direction of the Y-axis is Decrease from the initial value.

  Therefore, when the detected load value in one direction in the Y-axis direction of the monitored load cell 44 decreases, the controller 45 moves the nut member 36 to the Y-axis table 9 to the servo motor 35. A control command is given to move the direction in the other direction. Thereby, as the nut member 36 moves in the other direction in the Y-axis direction, the position of the fixed shoulder 40 of the friction stir welding tool 38 of the spindle unit 7 together with the Y-axis table main body 30 is It is displaced in the other direction of the Y-axis direction. For this reason, the decrease from the initial value of the load applied in one direction in the Y-axis direction is eliminated.

  The amount of movement of the nut member 36 of the Y-axis table 9 based on the detection signal of the load cell 44 of the controller 45 is controlled by, for example, the detected value of the load load in one direction in the Y-axis direction by the load cell 44, It is preferable to perform load feedback control using a feedback control technique similar to that conventionally known based on the detection signal of the load cell 44 so that the difference from the initial value becomes zero. In this way, the controller 45 easily controls the servo motor 35 of the Y-axis table 9 to make the detected value constant with the initial value in accordance with the detected value of the load cell 44. And it becomes possible to implement efficiently.

  When the friction stir welding apparatus according to the present invention having the above-described configuration is used, the workpieces 3 a and 3 b to be joined to fillet are held on the X-axis table 5 via the jig 37.

  Next, the X-axis table 5, the Z-axis table 8, and the Y-axis table 9 are positioned and controlled, and the friction stir welding tool 38 of the spindle unit 7 is placed in the initial state described above. The positioning control function at this time may be provided in the controller 45, or may be provided in another controller (not shown) linked to the controller 45.

  Next, in a state where the probe 39 of the friction stir welding tool 38 is driven to rotate, the X-axis table 5 is operated, and the friction stir welding tool 38 is moved along the joining line 4 between the workpieces 3a and 3b. By relatively moving, the friction stir welding at the position of the joining line 4 of the workpieces 3a and 3b by the probe 39 is performed. At this time, load feedback control by the controller 45 is started.

  As a result, when performing friction stir welding, the above-mentioned X due to the manufacturing accuracy of the workpieces 3a and 3b, the accuracy when holding the workpieces 3a and 3b via the jig 37 with respect to the X-axis table 5, etc. When the parallelism between the traveling direction of the workpieces 3a and 3b accompanying the operation of the shaft table 5 and the joining line 4 is reduced, the workpiece contact surface 42a or 42b of the fixed shoulder 40 of the friction stir welding tool 38 The interference with the workpiece 3a or 3b is increased. Therefore, due to the increase of the interference, the load in the Y-axis direction as the horizontal direction orthogonal to the X-axis direction that is the traveling direction of the workpieces 3a and 3b changes from the initial value.

  When a change in the load in the Y-axis direction is detected by the load cell 44, a control command is given from the controller 45 to the servo motor 35 of the Y-axis table 9 based on a detection signal from the load cell 44. Thus, the position of the fixed shoulder 40 of the friction stir welding tool 38 is controlled together with the Y-axis table main body 30 so that the changed load load coincides with the initial value. Thereby, since the positional relationship of the fixed shoulder 40 of the friction stir welding tool 38 with respect to the workpieces 3a and 3b is the same arrangement as in the initial state, the position of the probe 39 is the joining line of the workpieces 3a and 3b. 4 is prevented from coming off the position 4.

  Thereafter, while continuing the load feedback control by the controller 45, the probe 39 of the friction stir welding tool 38 is moved over the entire length of the joining line 4 of the workpieces 3a and 3b, and the construction of the friction stir welding is completed. After the load feedback control by the controller 45 is finished, the Z-axis table 8 and the Y-axis table 9 are operated again by the positioning control, and the friction stir welding tool 38 is moved to a predetermined standby position. Try to evacuate.

  Thus, according to the friction stir welding apparatus of the present invention, the joining line 4 of the workpieces 3a and 3b is relative to the X-axis direction, which is the relative movement direction of the workpieces 3a and 3b and the friction stir welding tool 38. Even when the position is displaced in the Y-axis direction or when the joining line 4 is inclined in the horizontal plane, the probe 39 of the friction stir welding tool 38 is connected to the joining line 4. It can be moved following the above.

  In addition, the copying control of the friction stir welding tool 38 is based on the change in the contact pressure between the fixed shoulder 40 of the friction stir welding tool 38 and the workpieces 3a and 3b where the friction stir welding is performed by the probe 39. Therefore, the accuracy of the copying control can be increased, and malfunction can be prevented.

  Therefore, when the workpieces 3a and 3b are held on the X-axis table 5, the friction stir welding at the position of the joining line 4 between the workpieces 3a and 3b is performed without performing precise positioning of the workpieces 3a and 3b. It can be carried out well.

  Therefore, even when the workpieces 3a and 3b are long, the workpieces 3a and 3b can be easily held on the X-axis table 5 and the friction stir welding can be performed.

  Furthermore, in the friction stir welding apparatus of the present invention, the construction conditions of the friction stir welding are stabilized by controlling the probe 39 following the joining line 4 of the workpieces 3a and 3b. Can be improved.

  In addition, this invention is not limited only to the said embodiment, The workpiece | work contact surfaces 42a and 42b of the fixed type shoulder 40 of the friction stir welding tool 38, and the workpiece | work 3a and 3b used as fillet joining object are joined. A change in contact pressure in the Y-axis direction, which is a horizontal direction orthogonal to the relative movement direction of the friction stir welding tool 38 and the workpieces 3a and 3b, can be detected with respect to a surface arranged as an inclined surface across the line 4. If so, for example, a configuration in which a load cell is interposed at an attachment location of the fixed shoulder 40 in the spindle unit 7 or a load cell is provided at an attachment location of the spindle unit 7 in the Y-axis table main body 30 of the Y-axis table 9. You may employ | adopt the structure which installs a load cell in places other than illustration, such as a structure to wear. In these cases, the type and mounting structure of the load cell to be used may be appropriately set so that a change in the contact pressure in the Y-axis direction can be detected.

  Furthermore, if it has a function as a traverse axis for controlling the position of the friction stir welding tool 38 in the horizontal direction orthogonal to the relative movement direction of the friction stir welding tool 38 and the workpieces 3a, 3b, the Y axis table 9 Instead of this, any linear motion mechanism may be employed. In this case, when the friction stir welding is performed, the linear motion mechanism applies a large downward pressing force to the probe 39 in order to immerse the probe 39 of the friction stir welding tool 38 into the joint between the workpieces 3a and 3b. As long as the position of the friction stir welding tool 38 can be controlled in the horizontal direction orthogonal to the relative movement direction of the friction stir welding tool 38 and the workpieces 3a and 3b, a trapezoidal screw linear motion mechanism, a linear motor Any type of linear motion mechanism other than the ball screw linear motion mechanism 31 such as a linear motion mechanism may be adopted. Furthermore, the detection means for detecting a change in the contact pressure in the horizontal direction orthogonal to the relative movement direction between the friction stir welding tool 38 and the workpieces 3a and 3b includes a driven member in the linear motion mechanism, and the friction stirrer. What is necessary is just to prepare for any part of the structure which connects the joining tool 38. FIG.

  In the above embodiment, the friction stir welding apparatus of the present invention has been shown as including the triaxial gate-type main shaft positioning mechanism 1 as the main shaft unit 7 positioning mechanism. However, the main shaft unit 7 is attached to the workpieces 3a and 3b. The main shaft unit 7 can be relatively displaced over the entire length of the joining line 4 of the workpieces 3a and 3b. A positioning mechanism for the main spindle unit 7 may be employed.

  The Z-axis table 8 has a configuration including a ball screw linear motion mechanism 22 as a linear motion mechanism for moving the Z-axis table main body 21 in the vertical direction (Z-axis direction). When the friction stir welding is performed, the reaction force of the downward large pressing force that acts on the probe 39 to immerse the probe 39 of the friction stir welding tool 38 into the joint portion of the workpieces 3a and 3b. Any type of linear motion mechanism other than the ball screw linear motion mechanism 22 such as a linear motion mechanism using a trapezoidal screw may be adopted.

  The X-axis table 5 has a configuration including a ball screw linear motion mechanism 13 as a linear motion mechanism for moving the X-axis table main body 12. However, when the friction stir welding is performed, the probe of the friction stir welding tool 38 is shown. The friction stir welding tool 38 and the workpieces 3a and 3b are connected to the workpieces 3a and 3b in a state where a large downward pressing force is applied to the probe 39 in order to immerse 39 in the joints of the workpieces 3a and 3b. Any type of linear motion mechanism other than the ball screw linear motion mechanism 13, such as a linear motion mechanism using a trapezoidal screw or a linear motion mechanism using a linear motor, can be used as long as it can be relatively moved in the direction along the weld line 4. A configuration may be adopted.

  The fixed shoulder 40 of the friction stir welding tool 38 may have any shape on the upper side as long as the lower end portion has a V shape including two workpiece contact surfaces 42a and 42b.

  Of course, various modifications can be made without departing from the scope of the present invention.

3a, 3b Workpiece 4 Joining line 9 Y-axis table (transverse axis)
38 Friction stir welding tool 39 Probe 40 Fixed shoulder 42a, 42b Workpiece contact surface 44 Load cell (detection means)
45 Controller

Claims (2)

In a friction stir welding apparatus having a friction stir welding tool having a probe capable of rotation and a fixed shoulder,
The fixed shoulder is configured to have a V-shaped lower end portion by two workpiece contact surfaces for bringing the fixed shoulder into contact with the surfaces sandwiching the joining line of the workpiece to be joined to the fillet.
Furthermore, a traverse axis for enabling the friction stir welding tool to move in a horizontal direction perpendicular to the direction of relative movement with the workpiece during friction stir welding,
Means for detecting a contact pressure in a direction parallel to the transverse axis with respect to the workpiece of the fixed shoulder;
A friction stir welding system comprising: a controller that gives a command for controlling the position of the friction stir welding tool to the transverse axis according to a detected value of the contact pressure by the detection means. apparatus.   The controller monitors the detection value of the contact pressure input from the detection means, and the difference between the input detection value and the initial value of the detection value at the start of friction stir welding is zero. 2. The friction stir welding apparatus according to claim 1, wherein the transverse axis has a function of performing load feedback control of the position of the friction stir welding tool.

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