JP2004098172A - Friction stir welding equipment - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a friction stir welding apparatus capable of filling and joining a cavity in a short time.
SOLUTION: An insertion hole 35 is formed in a rotor 2 along a rotation axis L, and a pin shaft 36 is inserted therein. The pin shaft 36 protrudes from the shoulder 50 at the tip of the rotor 2. The switching of the direction of the linear movement of the pin shaft 36 relative to the rotor 2 is controlled by an electromagnetic brake. At the time of joining, the rotor 2 is lowered with the pin shaft protruding, the pin shaft 36 is inserted into the work, and pressed by the shoulder portion 50. At the end of joining, the pin shaft 36 is pulled up while maintaining the pressing force of the end surface of the shoulder portion 50 until the end surface of the rotor tip and the tip of the pin shaft 36 are flush. At this time, the workpiece softened by the frictional heat flows into the cavity generated by raising the pin shaft 36 due to the pressing force, and the cavity is filled.
[Selection diagram] Fig. 1

Description

The present invention relates to a friction stir welding apparatus that softens, stirs, and joins an object by frictional heat generated by rotation.

In friction stir welding, the pin is inserted into the work while rotating the rotor having the pin at the tip at a high speed, and the work is softened and agitated by friction heat and joined. In conventional friction stir welding, particularly spot welding, when the rotor is pulled up and the embedded pin is extracted, a cavity corresponding to the pin is formed at the welding site.

と When the cavity is formed in this way, stress is concentrated on the cavity, and the bonding strength is reduced. In particular, fatigue fracture is likely to occur. In addition, the appearance is deteriorated, which is not preferable in terms of aesthetic appearance, and stains are formed. As described above, various problems are caused in the application, and there is a problem in product quality.

In view of such a problem, the present inventor has proposed a method of suppressing the formation of a cavity by making the pin movable, pulling out the pin after joining, and then pressing again.

However, in the above-described method of pulling out the pins, there is a time lag between the operation of pulling out the pins and the operation of re-pressing, so that the time required for joining is increased by this time. Further, once the pin is pulled out, the base material is cooled and the cavity may not be sufficiently filled.

目的 An object of the present invention is to provide a friction stir welding apparatus capable of filling and joining a cavity in a short time.

The present invention moves a rotor that rotates at a high speed in the direction of the rotation axis, presses a rotor tip against a workpiece, and softens a contact portion between the rotor tip and the workpiece by frictional heat generated by rotation. In a friction stir welding apparatus that stirs and spot-welds the workpiece by stirring,
The rotor has an axial pin that is inserted into the rotor and is provided so as to be relatively linearly movable in the direction of the rotation axis.At the end of welding, the object to be welded is pressed against the end face of the end face of the rotor tip. While maintaining and pressing, the shaft-shaped pin is relatively moved, and by the pressing force, the object to be welded softened by frictional heat flows into the space from which the shaft-shaped pin is pulled out, and the space is moved. It is a friction stir welding apparatus characterized by filling.

The present invention is further characterized in that the rotor tip has a cylindrical ring portion, and the shaft-like pin is an inner shaft that is displaceably inserted into the ring portion.

Also, the present invention moves the rotor that rotates at high speed in the direction of the rotation axis, presses the rotor tip against the workpiece, and contacts the contact between the rotor tip and the workpiece by frictional heat due to rotation. In a friction stir welding apparatus that softens, stirs, and continuously joins workpieces,
The rotor has an axial pin that is inserted through the rotor and is provided so as to be relatively linearly movable in the direction of the rotation axis.At the time of joining, the object to be welded is pressed against the end face of the end of the rotor tip. While maintaining and pressing, the shaft-shaped pin is relatively moved, and by the pressing force, the workpiece softened by frictional heat flows into the space from which the shaft-shaped pin has been pulled out, thereby changing the space. It is a friction stir welding apparatus characterized by filling.

The present invention is also characterized in that the rotation of the rotor and the linear movement of the shaft-shaped pin relative to the rotor are performed by the same drive source.

Further, according to the present invention, a brake mechanism or a clutch mechanism switches between an integrated movement state in which the rotor and the shaft-shaped pin move in a straight line integrally and a relative movement state in which the rotor and the shaft-shaped pin relatively move. It is characterized by the following.

The present invention is also characterized in that the direction of the relative movement is switched by switching the rotation direction of the rotor.

Further, the present invention is characterized in that at the end of joining, the shaft-shaped pin is moved and pressed until the end face of the rotor tip and the tip of the pin are flush with each other.

Further, the present invention is characterized in that the shaft-shaped pin is moved until the end face of the rotor tip and the tip of the pin are flush with each other, and then pressed for a predetermined time.

According to the present invention, the shaft-shaped pin is inserted into the rotor so as to be relatively linearly movable, and when the joining is completed, the shaft-shaped pin is pulled out. Here, in the present invention, since the to-be-joined object is pulled out while being pressed by the rotor tip, the surrounding base material flows into the space from which the shaft-shaped pin has been pulled out, and the cavity after the shaft-shaped pin has been drawn out is formed. Buried. In this way, the cavity can be filled faster than the above-described conventional technology. In addition, since the shaft-shaped pin is pulled out in a pressed state instead of filling in the cavity after being pulled out, the cavity can be reliably filled without cooling and hardening the softened base material.

According to the present invention, the present invention can be applied to a ring-type friction stir welding apparatus in which a ring portion is provided at the tip of the rotor.

According to the present invention, even in continuous joining, since the shaft-shaped pin is pulled out while the pressing of the article to be joined by the rotor tip is maintained, the surrounding base material flows into the space where the shaft-shaped pin has been drawn out, The cavity after pulling out the shaft pin is filled. In this way, the cavity can be filled faster than the above-described conventional technology. In addition, since the shaft-shaped pin is pulled out in a pressed state instead of filling in the cavity after being pulled out, the cavity can be reliably filled without cooling and hardening the softened base material. In addition, by using a common drive source, the weight of the device itself can be reduced, and the manufacturing cost can be reduced.

According to the present invention, by using a common drive source, the weight of the device itself can be reduced, and the manufacturing cost can be reduced.

According to the present invention, it is possible to switch between the integrated movement state and the relative movement state with a simple configuration such as a brake mechanism or a clutch mechanism.

According to the present invention, by switching the rotation direction of the rotor, the integrated movement state and the relative movement state are switched, so that the joining control is facilitated.

According to the present invention, by pressing with the flattened rotor tip, the work surface of the joining word can be flattened and the aesthetic appearance can be improved.

According to the present invention, by pressing the rotor for a predetermined period of time with the tip of the rotor being flat, the cavity can be more reliably filled and the recess can be prevented.

According to the present invention, since the shaft-shaped pin is pulled out while maintaining the pressing of the article to be joined by the rotor tip, the surrounding base material flows into the space where the shaft-shaped pin has been drawn out, and the shaft-shaped pin is removed. The cavity after withdrawal is filled.

Further, the present invention can be applied to a friction stir welding apparatus of a type in which a ring portion is provided at the tip of a rotor.
Further, the present invention can be applied to a case where continuous joining is performed.

According to the present invention, by using a common drive source, the weight of the device itself can be reduced, and the manufacturing cost can be reduced.

According to the present invention, it is possible to switch between the integrally moving state and the relative moving state with a simple configuration such as a brake mechanism or a clutch mechanism.

According to the present invention, since the direction of relative movement is switched by switching the rotation direction of the rotor, the joining control is facilitated.

According to the present invention, since the shaft is moved until the tip of the rotor is flat, the surface of the workpiece can be flat.

According to the present invention, by pressing the flattened rotor tip for a predetermined time, the cavity can be more reliably filled, and the surface of the workpiece can be flattened.

FIG. 1 is a view showing a configuration of a friction stir welding apparatus 1 according to an embodiment of the present invention. The friction stir welding apparatus 1 is mounted on, for example, a wrist of a six-axis vertical articulated robot and used as a welding gun.

The friction stir welding apparatus 1 includes a rotor 2, a rotating motor 3, a straight motor 4, and a gun arm (not shown) for supporting the rotor 2, and the gun arm is mounted on the wrist of the robot. The rotator 2 is held by a rotator holding member 5 and is supported by a gun arm so as to be rotatable about the rotation axis L and movable in the direction of the rotation axis L. The rotation motor 3 is an induction motor in the present embodiment, is fixed to the gun arm, and drives the rotor 2 to rotate about the rotation axis L. The rectilinear motor 4 is a servomotor in the present embodiment, is fixed to the gun arm, and drives the rotor 2 rectilinearly in the direction of the rotation axis L.

The rotor holding member 5 has a columnar shape, and the rotor 2 is mounted and fixed to the lower end portion with the rotation axis L being coaxial. A spline 10 is formed on the outer periphery of the rotor holding member 5 and is received by a spline receiver 11. The spline receiver 11 is fixedly supported on the gun arm by the bearing 12. A belt wheel is fixed to the outer periphery of the spline receiver 11, and a belt wheel 14 is also fixed to the output shaft of the rotation motor 3. The V belt is wound around the belt wheel 14 and the belt wheel of the spline receiver 11. With such a configuration, the rotor 2 can be driven to rotate around the rotation axis L at a high speed by driving the rotation motor 3. Further, since the rotational force is transmitted via the spline 10, it is possible to allow the linear movement along the rotation axis L while rotating.

直 A linear drive member 20 is attached to the lower end of the rotor holding member 5. The rectilinear driving member 20 has a cylindrical shape, and is connected to the rotor holding member 5 via a pair of bearings 21 so as to be rotatable around the rotation axis L and prevented from being displaced in the direction of the rotation axis L. . An outer screw is formed on the outer periphery of the linear drive member 20, and the ring-shaped inner screw member 22 is screwed to the outer screw of the linear drive member 20. The inner screw member 22 is attached to the gun arm via a bearing 23 fixed to the gun arm so as to be rotatable around the rotation axis L.

有 A toothed belt wheel is fixed to the outer periphery of the inner screw member 22. A toothed belt wheel 24 is also fixed to the output shaft of the linear motor 4, and a timing belt 25 is wound around the toothed belt wheel 24 and the toothed belt wheel of the inner screw member 22. A groove 27 parallel to the rotation axis L is formed in the outer peripheral portion of the linear drive member 20. A detent ring 26 (see FIG. 2), which has a ring shape and has a convex portion that fits in the groove 27, is fixedly supported on the gun arm on the outer periphery of the rectilinear driving member 20. This prevents the linear drive member 20 from rotating around the rotation axis L.

By driving the linear motor 4, the internal screw member 22 is driven to rotate via the timing belt 25, and the linear driving member 20 screwed to the internal screw member 22 moves linearly in the direction of the rotation axis L, thereby holding the rotor. The member 5 and the rotor 2 move straight in the direction of the rotation axis L. Further, since the linear drive member 20 and the rotor holding member 5 are connected via the bearing 21, the rotor 2 and the rotor holding member 20 are driven to rotate around the rotation axis L at a high speed while the rotation axis L It can move straight in the direction. In addition, since the linear driving member 20 that applies the linear driving force to the rotor 2 and the rotor holding member 5 applies the linear driving force with the rotation axis L as the common axis, the power transmission efficiency is good.

Further, a spline receiver 29 is fitted into the rotor holding member 5 at the center of the rotor holding member 5. The spline receiver 29 is rotatably supported on the gun arm by the bearing 28. With such a configuration, the rotor holding member 5 is supported so as to be able to move straight in the direction of the rotation axis L and to be rotatable about the rotation axis L.

挿 An insertion hole 35 is formed in the rotor 2 and the rotor holding member 5 along the rotation axis L, and a pin shaft 36 as an axial pin is inserted into the insertion hole 35. The pin shaft 36 is inserted from the rear end (upper end in FIG. 1) of the rotor holding member 5 to the front end of the rotor 2, and moves straight along the rotation axis L relative to the rotor 2 and the rotor holding member 5. It is provided movably.

At the rear end of the rotor holding member, there is provided a cylindrical shaft driving member 37 to which the pin shaft 36 is connected and integrated with the pin shaft 36. An outer screw is formed on the outer periphery of the shaft driving member 37. Further, an inner screw member 38 screwed to the outer screw of the shaft driving member 37 is fixed to the rear end of the rotor holding member 5. The driving member 37 has a cylindrical shape centered on the rotation axis L, and a spline shaft 39 is inserted into a rear portion (an upper portion in FIG. 1). That is, an insertion hole in which a spline receiver is formed at the rear portion of the driving member 37 is formed along the rotation axis L, and the spline shaft 39 is displaceable in the rotation axis L direction in this insertion hole. Rotation is prevented and inserted.

An electromagnetic brake 41 is connected to the rear end of the spline shaft 39 via a universal joint 40. The electromagnetic brake 41 is fixed to the gun arm, and when turned on and excited, prevents the rotation of the spline shaft 39, and when turned off, allows the rotation of the spline shaft 39.

先端 The tip of the rotor 2 has a conical shape, and a columnar shoulder 50 is formed at the tip, and an insertion hole 35 is opened at the center of the end face of the shoulder 50. When the pin shaft 36 moves straight to the distal end side, the pin shaft projects from the end surface of the shoulder portion 50. The protruding pin shaft 36 is a protruding portion, and the protruding pin shaft 36 is inserted into the work during friction stir welding. The pin shaft 36 can be switched between two states: a protruding state in which the pin shaft tip protrudes, and a flush state in which the pin shaft retracts and the pin shaft tip and the end face of the shoulder portion 50 are flush. . This switching is performed by a switching mechanism 51 provided at the rear end of the rotor holding member 5.

FIG. 3 is an enlarged view showing the switching mechanism 51. The switching mechanism 51 has a space 47 formed at the rear end of the rotor holding member 5, and the lower end of the shaft drive member 37 is exposed to the space 47. A flange is formed at the lower end of the shaft driving member 37, and this flange functions as a stopper 45.

The rotor holding member 5 is rotated around the rotation axis L by the rotation motor 3. At this time, when the clutch is off, the shaft driving member 37 also rotates together with the rotor holding member 5.

す る と When the electromagnetic brake is turned on, the rotation of the shaft drive member 37 stops. That is, the shaft driving member 37 rotates with respect to the screw member 38 of the rotor holding member 5, whereby the shaft driving member 37 and the pin shaft 36 are aligned with the rotor holding member 5 and the rotor 2 with respect to the axis. It moves relatively straight along L.

When the stopper 45 of the shaft drive member 37 reaches the lower surface 48 or the upper surface 49 of the space 47 in such a relative movement state, the movement of the shaft drive member 37 stops, and the shaft drive member 37 and the rotor holding member 5 are stopped. Move together and become an integrated movement state. In this way, the relative movement state and the integrated movement state are switched by the electromagnetic brake 41.

When the stopper 45 hits the lower surface 48, the tip of the pin shaft 36 projects from the end surface of the shoulder portion 50, and when the stopper 45 hits the upper surface 49, the pin shaft 36 is retracted and is flush. It becomes.

ば ね A spring member 46 is interposed between the stopper 45 of the shaft driving member 37 and the rotor holding member 5. Since a frictional force is generated between the spring member 46, the stopper 45, and the lower surface 48, when the electromagnetic brake 41 is in the OFF state and the rotor holding member 5 rotates, the rotor holding member 5 and the shaft driving member 37 are securely connected. Rotate together.

受 け A receiving portion (not shown) is attached to the gun arm so as to be opposed to the tip of the rotor. At the time of joining, the receiving portion and the tip of the rotor sandwich the work therebetween.

Next, the joining method of the friction stir welding apparatus of the present invention will be described with reference to the time chart of FIG. Here, it is assumed that two works superposed and arranged horizontally are spot-joined. The work is, for example, an aluminum alloy.

First, the robot positions the friction stir welding apparatus 1. That is, positioning of the friction stir welding apparatus 1 is performed so that the receiving portion is arranged below the welding point.

(1) First, in an initial state, the rotor 2 is disposed at an original position separated from the joining point by a predetermined distance, and the rotor 2 is reversely rotated by a rotation motor 3 at a predetermined speed, for example, at a high speed of about 2000 rpm (upward). Counterclockwise as viewed from above), and the pin shaft 36 is flush. At this time, the stopper 45 of the shaft drive member 37 is in contact with the upper surface 49 of the space 47. Also, since the electromagnetic brake 41 is OFF, the pin shaft 36 is rotating together with the rotor holding member 5 and the rotor 2.

(2) Next, the linear motor 4 is driven in accordance with the movement of the robot to move the rotor 2 forward (down).

(3) When the opening of the gun (the distance between the receiving portion and the tip of the rotor) reaches a predetermined opening, the electromagnetic brake 41 is turned on for a predetermined time. Then, the rotation of the pin shaft 36 and the shaft driving member 37 that have been rotating together with the rotor 2 is restricted by the electromagnetic brake 41. However, since it is connected to the electromagnetic brake 41 via the spline shaft 39, the electromagnetic brake 41 can freely move in the direction of the rotation axis L. Further, since the outer screw of the shaft driving member 37 and the screw member 38 of the rotor holding member 5 are right-handed screws, by restricting the rotation of the shaft driving member 37, the rotor holding member 5 and the rotor 2 The shaft driving member 37 and the pin shaft 36 move downward. Then, the descent is continued until the stopper 45 of the shaft driving member 37 reaches the lower surface 48 of the space 47. In this way, the ON duration of the electromagnetic brake is set for a time slightly longer than the time required for the stopper 45 to hit the lower surface 48. The braking force of the electromagnetic brake 41 is set to be smaller than the rotational force when the stopper 45 hits and the shaft driving member 37 rotates together with the rotor holding member 5. In this manner, the pin shaft 36 moves relatively straight with respect to the rotor 2, so that the tip of the pin shaft 36 projects from the end face of the shoulder portion 50, and the stopper 45 hits and stops. Thus, the pin shaft 36 is in a protruding state.

(4) After the electromagnetic brake 41 is turned off, the rotation motor 3 is rotated forward. Further, the lowering of the rotor 2 is continued.

(5) The pin shaft 36 protruding from the tip of the rotor comes into contact with the work, and a pressing force is generated. Then, the work is softened by frictional heat between the tip of the pin shaft 36 and the work, and is pressed to insert the pin shaft 36 into the work.

(6) When the pin shaft 36 is inserted and the end surface of the shoulder portion 50 comes into contact with the work, further pressing force is generated. The state at this time is shown in FIG. Then, it is pressed for a predetermined time. During this time, the stirring is performed by the rotation of the pin shaft 36 and the end face of the shoulder portion 50, and the friction stir welding of the work is performed.

(7) When a predetermined time has elapsed, the electromagnetic brake 41 is turned on for a predetermined time. Then, contrary to (3), the rotation of the shaft driving member 37 is restricted in a state where the screw member 38 of the rotor holding member 5 is rotating clockwise as viewed from above, so that the shaft driving member 37 is restricted. Moves upward with respect to the rotor holding member 5. Then, the stopper 45 comes into contact with the upper surface 49 of the space 47 to be in a flush state. The state at this time is shown in FIG. In this way, when the pin shaft 36 moves up, the pressing force acting on the work from the end face of the shoulder portion 50 is maintained. When the pin shaft 36 is pulled up without being pressed, a cavity h is formed after the pulled up pin shaft as shown in FIG. 6 (A), but the state where the pin shaft 36 is pressed by the end face of the shoulder portion 50 as described above. When the pin shaft 36 is pulled out, as shown in FIG. 6B, the base material softened by frictional heat flows into the space from which the pin shaft 36 has been drawn out sequentially by the pressing force to fill the cavity.

(8) Then, the rotor tip is pressed for a predetermined time while the rotor tip is flush.
(9) After pressing for a predetermined time, the linear motor 4 is reversely rotated to raise the rotor 2. When the end face of the shoulder portion 50 separates from the work, the pressing force becomes zero. Then, when the opening degree reaches a predetermined value, the rotation motor 3 is rotated in reverse to prepare for the next spot joining point.

(10) When the rotor 2 reaches the original position, one cycle ends.
In this way, spot joining can be performed without forming a cavity.

動 く When it is not preferable that the pin shaft 36 moves, the pin shaft 36 may move due to the frictional force between the work and the pin shaft. Next, the undesirable case of the pin shaft 36 will be discussed.

(1) No contact between the work and the pin shaft 36.
(2) No contact between the work and the pin shaft 36.
(3) No contact between the workpiece and the pin shaft 36.
(4) No contact between the workpiece and the pin shaft 36.
(5) The workpiece contacts the pin shaft 36. Pin shaft protruding state. Rotation motor forward rotation → Undesirable direction of rising of pin shaft (6) Contact between work and pin shaft 36. Pin shaft protruding state. Rotation motor forward rotation → Undesirable direction of rising of pin shaft (7) Contact between workpiece and pin shaft 36. → Preferable direction of pin axis rise.
(8) The workpiece comes into contact with the pin shaft 36. → Preferable direction of pin axis rise.
(9) No contact between the workpiece and the pin shaft 36.
(10) No contact between the workpiece and the pin shaft.

Therefore, in order to oppose the frictional force between the work and the pin shaft in (5) and (6), the stopper 45 of the shaft driving member 37 and the lower surface 48 of the space 47 are provided as described with reference to FIG. A spring member 46 is interposed. Further, a structure without the spring member 46 may be adopted.

Further, in the above-described embodiment, the case of spot welding has been described. However, the pin-type friction stir welding apparatus 1 for projecting a pin shaft can be applied not only to spot welding but also to continuous welding. . In this case, in step (6), the friction stir welding apparatus 1 is moved by the robot while pressing the pin shaft in a protruding state, and the welding is continuously performed along the welding line. Also in the case of such a continuous joining, the joining can be performed without forming a cavity by pulling out the pin shaft while maintaining the pressing at the joining end point as described above.

Next, a ring-type friction stir welding apparatus as another embodiment of the friction stir welding apparatus of the present invention will be described. FIG. 7 is an enlarged cross-sectional view showing the tip of the rotor of the ring type friction stir welding apparatus. Since the ring-type friction stir welding apparatus has substantially the same configuration as the above-mentioned pin-type friction stir welding apparatus 1, the corresponding components are denoted by the same reference numerals and description thereof is omitted.

In the ring-type friction stir welding apparatus, a cylindrical ring portion 61 protrudes from an end surface to a shoulder portion 50 at a tip end of a rotor. The ring portion 61 is coaxial with the rotation axis L of the rotor 2 and is formed integrally with the shoulder portion 50. The insertion hole 35 formed in the rotor 2 penetrates the ring portion 61 and opens at the tip. The inner shaft 62 is inserted through the insertion hole 35, and moves straight in the direction of the rotation axis L with respect to the rotor 2. The inner shaft 62 is driven by the shaft drive member 37, similarly to the pin-type friction stir welding apparatus 1, and the moving direction of the shaft drive member 37 is switched by the switching mechanism 60.

FIG. 8 is an enlarged view showing the switching mechanism 60 of the ring-type friction stir welding apparatus. In the ring-type friction stir welding apparatus, contrary to the pin-type friction stir welding apparatus 1, when the inner shaft 62 is at the advanced position, the tip of the inner shaft 62 and the tip of the ring portion 61 coincide with each other to be flush. Thus, during normal joining, the inner shaft 62 is retracted to the same position as the end surface of the shoulder portion 50. As described above, since the operation is reverse to that of the pin-type friction stir welding apparatus 1, the switching mechanism 60 also differs in the position where the spring member 63 is interposed, as shown in FIG. 49.

Next, a joining method of the ring-type friction stir welding apparatus will be described with reference to a time chart of FIG.

(1) First, in an initial state, the rotor 2 is disposed at an original position separated from the joining point by a predetermined distance, the rotation motor 3 is rotating forward (clockwise as viewed from above), and the inner shaft is rotated. Reference numeral 62 denotes a flush state. At this time, the stopper 45 of the shaft drive member 37 is in contact with the lower surface 48 of the space 47. The electromagnetic brake 41 is off.

(2) Next, the linear motor 4 is driven in accordance with the movement of the robot to move the rotor 2 forward (down).

(3) When the opening of the gun reaches a predetermined opening, the electromagnetic brake 41 is turned on for a predetermined time. Then, the rotation of the shaft drive member 37 of the inner shaft 62 and the shaft drive member 37 that has been rotating together with the rotor 2 is restrained by the electromagnetic brake 41. However, since it is connected to the electromagnetic brake 41 via the spline shaft 39, the electromagnetic brake 41 can freely move in the direction of the rotation axis L. Further, since the outer screw of the shaft driving member 37 and the screw member 38 of the rotor holding member 5 are right-handed screws, by restricting the rotation of the shaft driving member 37, the rotor holding member 5 and the rotor 2 , The shaft drive member 37 and the inner shaft 62 move upward. Then, the shaft driving member 37 continues to rise until the stopper 45 of the shaft driving member 37 reaches the upper surface 49 of the space 47. In this way, the ON duration of the electromagnetic brake is set for a time slightly longer than the time required for the stopper 45 to hit. The braking force of the electromagnetic brake 41 is set to be smaller than the rotational force when the stopper 45 hits the upper surface 49 and the shaft driving member 37 rotates together with the rotor holding member 5. In this way, the inner shaft 62 moves straight and relatively with respect to the rotor 2, whereby the inner shaft 62 is retracted from the ring portion 61, and is in a retracted state.

(4) After the electromagnetic brake 41 is turned off, the rotation motor 3 is rotated in the reverse direction. The lowering of the rotor 2 continues.

(5) The tip of the ring portion 61 projecting from the tip of the rotor comes into contact with the work, and a pressing force is generated. Then, the work is softened by frictional heat between the tip of the ring portion 61 and the work, and is pressed to insert the ring portion 61 into the work.

(6) When the ring portion 61 is inserted and the end face of the shoulder portion 50 comes into contact with the work, further pressing force is generated. The state at this time is shown in FIG. Then, it is pressed for a predetermined time. During this time, the stirring is performed by the rotation of the end faces of the ring portion 61 and the shoulder portion 50, and the friction stir welding of the work is performed. Since the ring portion 61 has a larger contact area with the work than the pin, the friction efficiency and the stirring efficiency can be improved.

(7) When a predetermined time has elapsed, the electromagnetic brake 41 is turned on for a predetermined time. Then, contrary to (3), the rotation of the shaft driving member 37 is restrained in a state where the screw member 38 of the rotor holding member 5 is rotating counterclockwise as viewed from above, so that the shaft driving member is 37 moves straight down with respect to the rotor holding member 5. At the same time as the electromagnetic brake 41 is turned on, the motor 4 is rotated in the reverse direction to raise the rotor 2 by the same amount as the amount by which the shaft drive member 37 is lowered. That is, the tip of the inner shaft 62 is at the same position as viewed from the workpiece. In this manner, the ring portion 61 is pulled out while the state of being pressed by the inner shaft 36 is maintained. Then, the shaft driving member 37 moves down until the stopper 45 reaches the lower surface 48 of the space 47, and the ring 61 rises, so that the tip of the ring is flush with the workpiece. At this stage, the pressing by the shoulder portion 50 is eliminated, and the pressing is changed to the pressing by the inner shaft 62 and the ring portion 61. Then, the operation is performed in which the inner shaft 62 is flush with the inner shaft 62 while being pressed by the ring portion 61 and the inner shaft 62.

(8) Then, the rotor tip is pressed for a predetermined time while the rotor tip is flush.
(9) After pressing for a predetermined time, the rotor 2 is raised. When the tip of the rotor separates from the work, the pressing force becomes zero. Then, when the opening degree reaches a predetermined value, the rotation motor 3 is rotated forward to prepare for the next spot joining point.

(10) When the rotor 2 reaches the original position, one cycle ends.
In this way, in the friction stir welding apparatus of the ring-type pin, when the ring portion 61 is pulled up, the inner shaft 62 is lowered so that the ring-shaped pin can be pulled up while maintaining the pressed state, and formed when the ring portion 61 is pulled up. Cavity can be filled.

Next, a case where the inner shaft 62 may move due to the frictional force between the work and the pin shaft in the ring-type friction stir welding apparatus will be considered.

(1) No contact between the work and the inner shaft 62.
(2) No contact between the work and the inner shaft 62.
(3) No contact between the work and the inner shaft 62.
(4) No contact between the workpiece and the inner shaft 62.
(5) No contact between the work and the inner shaft 62.
(6) The workpiece contacts the inner shaft 62. Inner shaft 62 retracted. Rotation motor reverse rotation → inner shaft protruding.
(7) The workpiece contacts the inner shaft 62. → The preferred direction of descending the inner shaft 62.
(8) The workpiece contacts the inner shaft 62. → The inner shaft 62 descends and hits. Preferred direction.
(9) No contact between the work and the inner shaft 62.
(10) No contact between the work and the inner shaft 62.

Therefore, in order to oppose the frictional force between the workpiece and the inner shaft 62 in the step (6), a spring member 49 is provided as shown in FIG. Further, a structure without the spring member 49 may be adopted.

In each of the embodiments described above, the electromagnetic brake is used to switch the driving of the pin shaft 36 and the inner shaft 62. However, the present invention is not limited to this, and the switching may be performed using an electromagnetic clutch. In the above-described embodiment, the induction motor is used as the straight drive motor, but a servo motor may be used. Thereby, the rotation direction of the motor can be quickly switched.

The present invention is capable of the following embodiments.
(1) The rotor that rotates at a high speed is moved in the direction of the rotation axis, the tip of the rotor is pressed against the workpiece, and the contact portion between the rotor tip and the workpiece is softened by frictional heat generated by rotation. In the friction stir welding apparatus that joins the workpieces by stirring, the rotor has a shaft-shaped pin that is inserted into the rotor and that is provided so as to be relatively linearly movable in the rotation axis direction. A friction stir welding apparatus wherein spot welding is performed, and at the end of welding, the shaft-shaped pin is relatively moved while pressing the object to be welded.

It is a figure showing the structure of pin-type friction stir welding device 1 which is one embodiment of the present invention. It is a figure which shows the detent 26. FIG. 4 is an enlarged view showing a switching mechanism 51. 4 is a time chart showing a joining method of the pin-type friction stir welding apparatus 1. It is sectional drawing which shows the state at the time of pin shaft insertion. It is sectional drawing which shows the state at the time of pulling out a pin shaft compared with the former. It is sectional drawing which shows the rotor front-end | tip part of the ring type friction stir welding apparatus which is another embodiment of this invention. It is a figure which expands and shows the switching mechanism 60 of a ring type friction stir welding apparatus. 5 is a time chart showing a joining method of a ring-type friction stir welding apparatus. It is sectional drawing which shows the state at the time of joining of a ring type friction stir welding apparatus.

Explanation of reference numerals

DESCRIPTION OF SYMBOLS 1 Friction stir welding apparatus 2 Rotor 3 Rotation motor 4 Straight motor 5 Rotor holding member 41 Electromagnetic brake

Claims (8)

The rotor that rotates at high speed is moved in the direction of the rotation axis, the tip of the rotor is pressed against the workpiece, and the contact portion between the tip of the rotor and the workpiece is softened by frictional heat generated by rotation and stirred. In the friction stir welding device that spot-welds the workpiece by welding,
The rotor has an axial pin that is inserted through the rotor and is provided so as to be relatively linearly movable in the direction of the rotation axis.At the time of joining, the object to be welded is pressed against the end face of the end of the rotor tip. While maintaining and pressing, the shaft-shaped pin is relatively moved, and by the pressing force, the workpiece softened by frictional heat flows into the space from which the shaft-shaped pin has been pulled out, thereby changing the space. A friction stir welding apparatus characterized by filling. The friction stir welding apparatus according to claim 1, wherein the rotor tip has a cylindrical ring portion, and the shaft-shaped pin is an inner shaft that is displaceably inserted into the ring portion. The rotor that rotates at high speed is moved in the direction of the rotation axis, the tip of the rotor is pressed against the workpiece, and the contact portion between the tip of the rotor and the workpiece is softened by frictional heat generated by rotation and stirred. In a friction stir welding apparatus that continuously welds the workpieces,
The rotor has an axial pin that is inserted through the rotor and is provided so as to be relatively linearly movable in the direction of the rotation axis.At the time of joining, the object to be welded is pressed against the end face of the end of the rotor tip. While maintaining and pressing, the shaft-shaped pin is relatively moved, and by the pressing force, the workpiece softened by frictional heat flows into the space from which the shaft-shaped pin has been pulled out, thereby changing the space. A friction stir welding apparatus characterized by filling. The friction stir welding according to any one of claims 1 to 3, wherein the rotation of the rotor and the linear movement of the shaft-shaped pin relative to the rotor are performed by the same drive source. apparatus. A brake mechanism or a clutch mechanism is used to switch between an integrated movement state in which the rotor and the shaft-shaped pin move in a straight line integrally and a relative movement state in which the rotor and the shaft-shaped pin relatively move. The friction stir welding apparatus according to claim 1. 6. The friction stir welding apparatus according to claim 5, wherein the direction of the relative movement is switched by switching the rotation direction of the rotor. 7. The method according to claim 1, wherein when the joining is completed, the axial pin is moved and pressed until the end face of the rotor tip and the tip of the pin are flush with each other. The friction stir welding apparatus according to any one of the first to third aspects. The friction stir welding apparatus according to claim 7, wherein the shaft-like pin is moved until the end face of the rotor tip and the tip of the pin are flush with each other, and then pressed for a predetermined time. .

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