WO2016021538A1

WO2016021538A1 - Friction stir welding device

Info

Publication number: WO2016021538A1
Application number: PCT/JP2015/071929
Authority: WO
Inventors: 眞実安齋; 佐山　満; 佳佑蔦; 亮二北村
Original assignee: 本田技研工業株式会社; ファナック株式会社
Priority date: 2014-08-07
Filing date: 2015-08-03
Publication date: 2016-02-11

Abstract

The purpose of the present invention is to provide a lightweight and compact friction stir welding device equipped with an upper rotating body and a lower rotating body. This friction stir welding device (10) is configured so as to be equipped with: an upper rotating body (36); a lower rotating body (15); a rotating principal shaft (14) for passing through the interior of the upper rotating body and integrally provided with the lower rotating body; a first actuator (16) for imparting a rotational force on the rotating principal shaft; a second actuator (27) for moving the upper rotating body in the axial direction; a load sensor (39) for detecting an axial load applied to the second actuator; a load control unit (41) for controlling the load to be applied to a workpiece by the upper rotating body, on the basis of load information obtained from the load sensor; a position sensor (43) for detecting the position of the lower rotating body; and a controller (44) for controlling the position of the lower rotating body on the basis of the position information from the position sensor.

Description

Friction stir welding equipment

The present invention relates to a friction stir welding apparatus having an upper rotating body and a lower rotating body.

∙ Friction stir welding is known, in which a rotating body that rotates at high speed is applied to a workpiece to generate frictional heat and promote stirring. Furthermore, a joining technique in which a workpiece is sandwiched between an upper rotating body and a lower rotating body is known (for example, Patent Document 1).

The friction stir welding apparatus disclosed in Patent Document 1 includes an upper rotating body, an upper actuator that presses the upper rotating body against a workpiece with a predetermined load, a lower rotating body, and the lower rotating body with another predetermined load. A lower actuator that presses against the workpiece and a rotation actuator that rotates the upper and lower rotating bodies are provided.

That is, the apparatus according to Patent Document 1 requires three actuators, that is, an upper actuator, a lower actuator, and a rotation actuator.
In recent years, robots have been introduced as part of productivity improvements. Considering attaching the upper rotating body and the lower rotating body to the tip of the robot, further reduction in weight and size of the friction stir welding apparatus is required in order to reduce the burden on the robot.

US Pat. No. 6,1997,745

An object of the present invention is to provide a lightweight and compact friction stir welding apparatus in a friction stir welding apparatus including an upper rotating body and a lower rotating body.

The invention according to claim 1 is provided integrally with the upper rotating body disposed on the workpiece, the lower rotating body disposed below the workpiece, and the lower rotating body, and inside the upper rotating body. A rotating main shaft that passes through the first rotating shaft, a first actuator that applies a rotational force to the rotating main shaft, a second actuator that moves the upper rotating body in the axial direction, and a load that detects an axial load applied to the second actuator. A sensor, a load control unit that controls a load applied to the workpiece by the upper rotating body based on load information obtained from the load sensor, a position sensor that detects a position of the lower rotating body, and a position sensor And a controller for controlling the position of the lower rotating body based on the position information.

In the invention according to claim 2, preferably, the rotation spindle moves up and down by a robot controlled by a controller.

In the invention according to claim 3, preferably, the axis of the first actuator, the axis of the second actuator, and the rotation main axis are supported by the robot while being arranged in parallel.

In the invention which concerns on Claim 1, the lower side rotary body does not have the actuator for load control. As a result, the present invention can be accomplished with two actuators.
Therefore, according to the present invention, a lightweight and compact friction stir welding apparatus provided with an upper rotating body and a lower rotating body is provided.

In the invention according to claim 2, since the robot is excellent in position control capability, the position of the rotating spindle is directly controlled using this robot. From another point of view, it can be said that the friction stir welding apparatus of the present invention is small and light, and can be easily attached to a robot.

In the invention according to claim 3, the axis of the first actuator and the axis of the second actuator are arranged in parallel on the rotation main shaft. By reducing the distance between the shafts, the friction stir welding apparatus can be easily downsized.

1 is a front view of a friction stir welding apparatus according to the present invention. It is an effect | action figure of an upper side rotary body and a lower side rotary body. It is a figure which compares an Example and a comparative example. It is a figure which shows the example of a change of the friction stir welding apparatus which concerns on this invention. It is a figure which shows the further example of a change of the friction stir welding apparatus which concerns on this invention. It is a figure which shows the further example of a change of the friction stir welding apparatus which concerns on this invention. It is a figure which shows the further example of a change of the friction stir welding apparatus which concerns on this invention.

Embodiments of the present invention will be described below with reference to the accompanying drawings.

As shown in FIG. 1, the friction stir welding apparatus 10 includes a substrate 11 that extends downward, a rotary spindle 14 that is rotatably supported on the substrate 11 by a pair of

bearings

12 and 13, and a rotary spindle 14 that extends downward. A lower rotary body 15 formed integrally with the lower end of the first actuator 16, a first actuator 16 attached to the substrate 11, and a first drive pulley 18 attached to the rotary shaft 17 of the first actuator 16. , A first driven pulley 19 provided on the rotary main shaft 14 at a position sandwiched between the pair of

bearings

12, 13, a first belt 21 spanning the first driven pulley 19 and the first drive pulley 18, and the rotary main shaft 14,

rails

22, 22 laid on the substrate 11 so as to be parallel to the board 14, a slider 23 movably attached to the

rails

22, 22, and a slider 23 attached to the slider 23. A ball nut 24, a ball screw 26 screwed into the ball nut 24 and rotatably supported on the substrate 11 by

support pieces

25, 25, a second actuator 27 attached to the substrate 11, A second drive pulley 29 attached to the rotating shaft 28 of the second actuator 27, a second driven pulley 31 provided on the ball screw 26 in the vicinity of one support piece 25, and the second driven pulley. 31 and a second belt 32 that spans the second drive pulley 29, a rotary cylinder 35 that is rotatably supported by the slider 23 via

bearings

33, 33, and a lower end of the rotary cylinder 35. And an upper rotating body 36. The rotary cylinder 35 surrounds the rotary spindle 14. The rotary cylinder 35 is connected to the rotary main shaft 14 via a spline 34.

The first actuator 16 is controlled by the rotation control unit 38.
A load sensor 39 is attached to the rotary shaft 28 of the second actuator 27. The load sensor 39 is, for example, a strain gauge that replaces the mechanical strain amount with an electrical signal. Alternatively, when the second actuator 27 is a servo motor, the load sensor 39 may detect a current and convert the current into a load.
The second actuator 27 is controlled by a load control unit 41 that controls the downward load of the upper rotating body 36 based on information from the load sensor 39.

In the present embodiment, the rotating shaft 17 of the first actuator 16, the rotating shaft 28 of the second actuator 27, and the rotating main shaft 14 are arranged in parallel to each other. The distance between the rotation main shaft 14 and the

rotation shafts

17 and 28 can be set arbitrarily. This can be done by adjusting the length of the

belts

21 and 32.
By reducing the distance between the shafts as much as possible, the friction stir welding apparatus 10 can be made compact, particularly the width in the horizontal direction can be reduced.

Since such a friction stir welding apparatus 10 is small and lightweight, it can be easily attached to the tip of the robot 42. The robot 42 has a position sensor 43 that monitors the coordinates of the tip and a controller 44 that controls the robot 42 while feeding back information from the position sensor 43.

The substrate 11 is carried to an arbitrary position by the robot 42. Since the rotation main shaft 14 is attached to the substrate 11 via the

bearings

12 and 13, the position (particularly the height position) of the lower rotating body 15 at the lower end of the rotation main shaft 14 is controlled by the controller 44.

On the other hand, the rotating cylinder 35 is connected to the rotating main shaft 14 by a spline 34 and is movable along the rotating main shaft 14. Therefore, when the ball screw 26 is rotated by the second actuator 27, the slider 23 is raised or lowered along the

rails

22 and 22. Then, the rotating cylinder 35 and the upper rotating body 36 move together with the slider 23. Therefore, the upper rotating body 36 is moved to an arbitrary position independently of the lower rotating body 15 using the second actuator 27 as a drive source, and the load control unit 41 performs load control.

When the rotating main shaft 14 is rotated by the first actuator 16, the rotating cylinder 35 is rotated through the spline 34. Therefore, the upper rotator 36 and the lower rotator 15 rotate in synchronization.

That is, in the friction stir welding apparatus 10, the lower rotating body 15 is integrally formed with the rotating main shaft 14, and the rotating main shaft 14 passes through the upper rotating body 36. The friction stir welding apparatus 10 includes a first actuator 16 that applies a rotational force to the rotary main shaft 14, a second actuator 27 that moves the upper rotating body 36 in the axial direction (moves in the axial direction), and a lower rotation. The controller 44 that controls the position of the body 15 is provided. The second actuator 27 performs load control based on the load obtained from the load sensor 39, and the controller 44 detects the position of the lower rotating body 15. Based on the information from the position sensor 43, the position of the lower rotating body 15 is controlled.

The position sensor 43 may be built in the controller 44. The driving

pulleys

18 and 29 and the driven

pulleys

19 and 31 may be gears. Further, the rotation main shaft 14 may be directly rotated by the first actuator 16 via a coupling. Similarly, the ball screw 26 may be directly rotated by the second actuator 27 via a coupling.
Therefore, the configuration of the friction stir welding apparatus 10 shown in FIG. 1 can be changed as appropriate.

Next, the operation of the friction stir welding apparatus 10 having the above configuration will be described.
As shown in FIG. 2A, the

workpieces

46 and 47 which are metal plates are brought into contact with each other. In this example, the

workpieces

46 and 47 may be overlapped with each other. In the case of superposition, two or more workpieces can be superposed and joined.
As shown in FIG. 2B, the upper rotator 36 and the lower rotator 15 are brought close to one end of the joint portion 48.

As shown in FIG. 2C, which is a CC arrow view of FIG. 2B, the lower rotating body 15 is applied to the lower surface of the work 46 and is held at that height. Next, the upper rotating body 36 is lowered and the upper surface of the work 46 is pressed with a predetermined load.
As shown in FIG. 2D, the upper rotating body 36 and the lower rotating body 15 are rotated at a predetermined rotation speed. Then, frictional heat is generated and fluidization occurs. In this state, it moves like an arrow.
As a result, as shown in FIG. 2 (e), the

workpieces

46 and 47 were joined together by the bead 49.

Next, the technology of the present invention is compared with the conventional technology.
In the embodiment shown in FIG. 3A, the position of the lower rotator 15 is controlled and the load of the upper rotator 36 is controlled.

On the other hand, in the comparative example shown in FIG. 3B, the lower rotating body 101 is pressed against the workpiece 103 with the upward load Fg2. Further, the upper rotating body 102 is pressed against the workpiece 103 with the downward load Fg1. That is, both the lower rotator 101 and the upper rotator 102 are subjected to load control. The workpiece 103 becomes soft due to the frictional heat. When the load is excessive, the lower rotating body 101 or the upper rotating body 102 bites into the work 103 excessively. As a countermeasure, reduce the load according to softening.
Now, when reducing the downward load Fg1 of the upper rotating body 102, the workpiece 103 may be lifted if the upward load Fg2 of the lower rotating body 101 is constant. Therefore, the upward load Fg2 of the lower rotating body 101 is reduced.

That is, when both the lower rotating body 101 and the upper rotating body 102 are subjected to load control, one affects the other, so-called hunting (the load signal fluctuates up and down) occurs, and the load increases or decreases more than necessary. Repeatedly, the load is not stable.
Further, the work 103 expands as the temperature rises. If left unattended, the load becomes excessive. Hunting also occurs at this time.

In this regard, in FIG. 3A, the position of the lower rotating body 15 is controlled and the load of the upper rotating body 36 is controlled, so that one does not affect the other. As a result, a stable joining operation can be maintained against the softening and expansion of the workpiece 46.

Next, a modified example of the present invention will be described.
The spline 34 described in FIG. 1 can be deleted.
That is, as shown in FIG. 4, the third actuator 51 is mounted on the extension 23 a of the slider 23, and the third drive pulley 52 is provided on the rotation shaft of the third actuator 51. Further, a third driven pulley 53 is provided on the rotating cylinder 35. The belt 54 is transferred to the third driven pulley 53 and the third drive pulley 52. The other components are the same as those in FIG.

The rotation control unit 38 controls the rotation speeds of the first actuator 16 and the third actuator 51. In addition to synchronizing the rotation speeds of the first actuator 16 and the third actuator 51, it is possible to make a difference. It is possible to change the heat input for each material in the case of dissimilar material overlapping joining by changing the vertical rotation speed.

The third actuator 51 described with reference to FIG. 4 can be deleted.
For example, as shown in FIG. 5, a first drive gear 56 and a third drive gear 57 are provided on the rotating shaft 17 of the first actuator 16. Further, a first driven gear 58 is provided on the rotation main shaft 14, and a first intermediate gear 59 is provided between the first driven gear 58 and the first drive gear 56. The first intermediate gear 59 is rotatably supported by the substrate 11 and plays a role of transmitting the rotation of the first drive gear 56 to the first driven gear 58.

Further, a wide third driven gear 61 is provided on the upper portion of the rotary cylinder 35, and a third intermediate gear 62 is provided between the third driven gear 61 and the third drive gear 57. The third intermediate gear 62 is rotatably supported by the substrate 11 and plays a role of transmitting the rotation of the third drive gear 57 to the third driven gear 61.

Since the first drive gear 56, the third drive gear 57, the first driven gear 58, the first intermediate gear 59 and the third intermediate gear 62 are supported directly or indirectly on the substrate 11, Does not move in the axial direction. On the other hand, the third driven gear 61 moves in the axial direction together with the slider 23.
Since the third driven gear 61 is sufficiently wide, there is no fear that the third driven gear 61 will come off the third intermediate gear 62 even if it moves in the axial direction.

The first drive gear 56 and the third drive gear 57 are rotated by the rotating shaft 17. The lower rotating body 15 and the upper rotating body 36 can be rotated by the first actuator 16. The other components are the same as those in FIG.

By making a difference between the gear diameters of the first drive gear 56 and the third drive gear 57, it is possible to easily make a difference between the rotation speed of the lower rotating body 15 and the rotation speed of the upper rotating body 36.

Further, the

gears

56, 57, 58 and 61 shown in FIG. 5 can be replaced with pulleys, and the

gears

59 and 62 can be changed to belts. A specific example will be described with reference to FIG.

As shown in FIG. 6, the slider 23 extends to the vicinity of the first actuator 16. Then, the first drive pulley 18 is fixed to the distal end side of the rotary shaft 17 of the first actuator 16, and the third drive pulley 52 is attached to the rotary shaft 17 through the spline 66. The third drive pulley 52 is rotatably supported by the slider 23 by

bearings

67 and 67.

Since the rotary shaft 17 is long, the tip is supported by the slider 23 via a bearing 68.
A first driven pulley 19 is attached to the rotation main shaft 14 in the center of the drawing, and a first belt 21 is passed to the first driven pulley 19 and the first drive pulley 18. Further, a third driven pulley 53 is attached to the rotating cylinder 35, and the third belt 54 is passed to the third driven pulley 53 and the third drive pulley 52. Other configurations are the same as those in FIG.

When the upper rotating body 36 moves up or down together with the slider 23, the third drive pulley 52 moves along the rotating shaft 17 along the spline 66. Therefore, the rotational force is smoothly transmitted from the first actuator 16 fixed to the substrate 11 to the upper rotating body 36 that moves together with the slider 23.

When heat input to the upper workpiece is unnecessary, the upper rotating member 36 is not rotated. In this case, the structure shown in FIG. 7 can be adopted.
That is, as shown in FIG. 7, the support cylinder 64 is fixed to the slider 23, and the upper disk 65 is integrally formed at the tip of the support cylinder 64. Although the upper disk 65 corresponds to the upper rotating member 36 but is a non-rotating member, the name and the code are changed. Since only the lower rotating body 15 is rotated, a bead can be formed only on the lower side. The other components are the same as those in FIG.

The present invention is suitable for a friction stir welding apparatus that joins two or more metal plates by a friction stir welding method.

DESCRIPTION OF SYMBOLS 10 ... Friction stir welding apparatus, 14 ... Rotation main shaft, 15 ... Lower side rotating body, 16 ... 1st actuator, 17 ... Rotation axis (axis | shaft of 1st actuator), 27 ... 2nd actuator, 28 ... Rotation axis (Axis of second actuator), 36 ... upper rotating body, 39 ... load sensor, 41 ... load control unit, 42 ... robot, 43 ... position sensor, 44 ... controller, 46, 47 ... work, 48 ... joint, 49 ... Bead.

Claims

An upper rotating body arranged on the workpiece;
A lower rotating body arranged under the workpiece;
A rotating main shaft that integrally includes the lower rotating body and penetrates the upper rotating body;
A first actuator that applies a rotational force to the rotary spindle;
A second actuator for moving the upper rotating body in the axial direction;
A load sensor for detecting an axial load applied to the second actuator;
Based on load information obtained from the load sensor, a load control unit that controls a load applied to the workpiece by the upper rotating body,
A position sensor for detecting the position of the lower rotating body;
A friction stir welding apparatus comprising: a controller that controls the position of the lower rotating body based on position information from the position sensor.
The friction stir welding apparatus according to claim 1, wherein the rotating spindle moves up and down by a robot controlled by the controller.
The friction stir welding apparatus according to claim 2, wherein the axis of the first actuator, the axis of the second actuator, and the rotation main axis are supported by the robot while being arranged in parallel.