JP3471317B2 - Friction stir welding equipment - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a friction stir welding apparatus for softening and stirring objects to be welded by frictional heat generated by rotation.

[0002]

2. Description of the Related Art FIG. 9 (a) is an enlarged view showing a tip of a rotor 1 of a conventional friction stir welding apparatus. The rotor 1 has a rotation axis L1, and a cylindrical shoulder portion 2 is formed at the tip, and a pin 3 projects from the center of an end surface 4 of the shoulder portion 2. In spot welding using friction stir welding, while rotating the rotor 1 at a high speed, the rotor 1 is lowered in the direction of the rotation axis L1 and the work is softened by the friction heat of the pin tip to insert the pin 3 into the work. And rotating pin 3
Also, the workpiece is agitated at the end face 4 of the shoulder portion and spot-joined.

[0003]

In friction stir welding, the shoulder end face 4 and the pin 3 which rotate at high speed during welding are used.
Since the work is agitated with, the base material scatters during joining. Due to such scattering of the base material, the bonding strength is reduced.

Further, since the softened work surface is pressed by the shoulder end surface 4, a protrusion 5 as shown in FIG. 10 is formed on the outer periphery of the shoulder end surface 4 to be pressed. As a result, the irregularities on the surface of the work become large,
The difference between the thick part and the thin part at the joint is remarkable. As a result, stress concentration occurs and the strength is reduced. Also,
Aesthetically unpleasant.

In view of the above problems, in order to reduce the scattering and improve the stirring efficiency at the shoulder portion, FIG.
Although there is a method of making the end surface 4 of the shoulder portion concave as shown in (b), the scattering cannot be completely eliminated. Also, swells are still formed.

An object of the present invention is to provide a friction stir welding apparatus capable of preventing the base material from scattering during welding and preventing the work surface from rising after welding.

[0007]

According to the present invention, a rotor that rotates at a high speed is moved in the direction of a rotation axis to press the tip end of the rotor against an article to be joined, so that the tip end of the rotor contacts the article to be joined. In a friction stir welding apparatus for softening the portion by frictional heat due to rotation and stirring to spot-join the objects to be welded, the rotor has a cylindrical shape that surrounds the rotor tip, and the rotor is rotatable about the rotation axis. Has an outer ring for contacting the tip with the surface of the object to be joined at the time of joining, a thrust bearing is interposed between the base end of the outer ring and the rotor, and the tip contacts the object to be joined. The friction stir welding device is characterized in that the outer ring does not rotate when the above is done.

According to the present invention, the outer ring is provided at the tip of the rotor, and the tip is brought into contact with the objects to be joined at the time of joining. As a result, it is possible to surely prevent the base material from being scattered by the outer ring being confined at the joint portion during the joint.
Further, by bringing the tip into contact with the surface of the article to be joined, it is possible to prevent the softened surface of the article to be joined from rising.

[0009]

Since the thrust bearing is interposed between the outer ring and the rotor, the outer ring is rotatably supported so that the outer ring does not rotate when the tip of the outer ring is brought into contact with the surface of the object to be joined at the time of joining. can do. As a result, it is possible to effectively suppress the swelling of the surfaces of the objects to be joined without damaging the work. Further, the present invention moves a rotor that rotates at a high speed in the direction of the rotation axis to press the rotor tip against an article to be welded, and the contact portion between the rotor tip and the article to be welded is rotated by friction heat. In a friction stir welding device for softening and stirring to spot-join objects to be welded, a cylindrical shape surrounding the rotor tip portion is provided on the rotor rotatably around a rotation axis, and at the time of joining, Has an outer ring that makes contact with the surface of the object to be welded, a thrust bearing is interposed between the base end of the outer ring and the rotor, and the outer ring does not rotate when the tip contacts the object to be welded. , A substantially flat shoulder surface is formed at the tip of the rotor, and the outer ring is
The friction stir welding apparatus is characterized in that the tip is arranged at a position retracted from the shoulder surface. According to the present invention, since the tip of the outer ring is at the position retracted from the shoulder surface, when the rotor is lowered at the time of joining, the shoulder surface first comes into contact with the article to be joined, and further descends so that a predetermined pressing force is applied. When it occurs, the tip of the outer ring contacts the surface of the object to be joined. Therefore, without providing a spring or the like, it is possible to reliably surround the protruding portion with the outer ring at the time of joining and prevent the base material from scattering. Further, the present invention moves a rotor that rotates at a high speed in the direction of the rotation axis to press the rotor tip against an article to be welded, and the contact portion between the rotor tip and the article to be welded is rotated by friction heat. In a friction stir welding device for softening and stirring to spot-join objects to be welded, a cylindrical shape surrounding the rotor tip portion is provided on the rotor rotatably around a rotation axis, and at the time of joining, Has an outer ring that makes contact with the surface of the object to be welded, a thrust bearing is interposed between the base end of the outer ring and the rotor, and the outer ring does not rotate when the tip contacts the object to be welded. The friction stir welding device is characterized in that a protruding portion protrudes from the center of the rotor tip, and the protruding portion is a pin or a cylindrical ring. INDUSTRIAL APPLICABILITY The present invention can be applied to either a pin-type friction stir welding apparatus having a pin at the rotor tip or a ring-type friction stir welding apparatus having a ring at the rotor tip.

Further, the present invention is characterized in that a spring is provided between the thrust bearing and the base end portion of the outer ring to elastically press the tip of the outer ring against the surface of the article to be joined at the time of joining.

Further, the present invention is characterized in that the outer ring has elasticity in a rotation axis direction and elastically presses the tip of the outer ring against the surface of the article to be joined at the time of joining.

According to the present invention, at the time of joining, the rotor is lowered so that the protruding portion is brought into contact with the surface of the article to be joined. At this time, a spring is interposed between the outer ring and the rotor, or the outer ring itself has elasticity. When the rotor is lowered, the tip of the outer ring first comes into contact with the surface of the object to be joined, and by further lowering the rotor, the spring or outer ring is elastically compressed,
The tip of the outer ring is elastically pressed against the surface of the joined object.
In this way, the outer ring can allow the movement of the rotor, can reliably surround the protruding portion during joining, and can prevent the base material from scattering.

[0014]

[0015]

[0016]

[0017]

[0018]

FIG. 1 is a front view showing the vicinity of a rotor 11 of a friction stir welding apparatus 10 according to an embodiment of the present invention. The friction stir welding apparatus 10 is mounted on the wrist of an articulated robot, for example, and is used as a spot welding gun.

The rotor 11 is held by a rotor holding member 12 having a rotation axis L in common. Rotor holding member 12
Is supported by a frame (not shown) so as to be rotatable about the rotation axis L and linearly movable in the direction of the rotation axis L.
This frame is attached to the wrist of the robot. A rotation and rectilinear drive source (not shown) is provided on the frame, whereby the rotor holding member 12 and the rotor 1 are provided.
1 can be driven straight along the rotation axis L while rotating at high speed around the rotation axis L.

The tip of the rotor 11 is tapered, and a cylindrical shoulder portion 13 centered on the rotation axis L is formed at the tip.
Is formed. An outer ring 20 is provided on the outer periphery of the shoulder portion 13.
Fits in. Further, the end surface 14 of the shoulder portion 13 is
It is a flat surface perpendicular to the rotation axis L, and the rotation axis L is from the center.
The pin 15 projects downward along the direction.

A receiving portion 16 that opposes the tip of the rotor 11 is fixed to the frame. At the time of spot welding, the two workpieces W1 and W2 are sandwiched between the receiving portion 6 and the rotor 11 to perform welding.

FIG. 2 is an enlarged view showing the tip of the rotor 11. A cylindrical recess 21 is cut out along the outer circumference of the shoulder portion 13 at the tip of the rotor 11, and a cylindrical outer ring 20 is loosely fitted in the recess 21. 21 in the recess
A thrust bearing 23 is mounted on the bottom portion (upper end portion) of the spring 2 between the thrust bearing 23 and the outer ring 20.
2 is interposed. With such a configuration, the outer ring 20
Is provided so as to be rotatable about the rotation axis L and movable in the rotation axis L direction. The outer ring 20 is in a natural state,
The tip 20a is located at a position projecting below the pin 15.

Next, a method of joining the friction stir welding apparatus 10 will be described. Two work pieces W to be joined
1 and W2 are superposed and positioned by the robot so that the friction stir welding apparatus 10 is positioned so that the receiving portion 16 is placed below the welding point. The works W1 and W2 are
For example, aluminum alloy.

(1) First, the rotor 11 is, for example, 200
Rotate at a high speed of about 0 rpm. At this time, the outer ring 20
Rotates with the rotor 11.

(2) When the rotor 11 descends and the tip 20a of the outer ring 20 contacts the work W1, the outer ring 20a stops rotating. Since the thrust bearing 23 is attached to the base end portion 20b of the outer ring 20 via the spring 22, the rotation of the rotor 11 is not transmitted to the outer ring 20. Outer ring 20
And the work W1 are in close contact with each other and become one.

(3) When the rotor 11 is further lowered, the spring 22 is compressed, and at the same time, the pin 15 and the shoulder end surface 14 contact the work W1 (FIG. 3).

(4) The rotor 11 is further lowered and the pin 1
5 is inserted beyond the joining surface of the works W1 and W2, a predetermined pressing force is generated in the pin 15 and the shoulder portion 13, and the works are stirred at the joining point. Also at this time, the outer ring 20 is pressed against the surface of the work W1 in close contact with it, preventing the softened base material from scattering from the pin 13 and the shoulder portion 13, and at the same time, as shown in FIG. It is possible to prevent the base material from moving around the shoulder end surface 14 by the pressing of 14 and prevent the circumference of the shoulder 13 from rising.

(5) When the rotor 11 is raised after being pressed for a predetermined time, the pressing force of the pin 15 and the shoulder portion 13 becomes zero first. At this time, the outer ring 20 is still in close contact with the work W1.

(6) When the rotor is further raised, the outer ring 20 is also separated from the work W1 and returns to the state before pressing. As a result, as shown in FIG. 5, spot joining is performed in a state where there is no swelling around the shoulder portion.

FIG. 6 is a sectional view showing a rotor tip of a friction stir welding apparatus according to another embodiment of the present invention. In the present embodiment, the configuration other than the outer ring 30 is the same as that of the above-described embodiment, and therefore the corresponding components are designated by the same reference numerals and the description thereof is omitted.

The outer ring 30 of this embodiment is constructed integrally with the spring 31. That is, the outer ring 30 that fits into the recess 21 formed in the rotor is supported by the short cylindrical tip 32 that is mounted near the opening of the recess and the thrust bearing 23 that is mounted on the bottom of the recess 21. The base portion 33 and the tubular leaf spring 31 that connects the tip end portion 32 and the base portion 33 are integrally configured. The leaf spring 31 has a corrugated plate shape and can elastically expand and contract in the direction of the axis L. Even with the outer ring 30 having such a configuration, it is possible to prevent the base material from scattering at the time of joining and prevent the outer periphery of the shoulder portion 13 from rising, as in the above-described embodiment.

FIG. 7 is an enlarged sectional view showing a rotor tip of a friction stir welding apparatus according to still another embodiment of the present invention. In this embodiment as well, the configuration other than the outer ring 40 is the same as that of the above-described embodiment, so the same reference numerals are given to the corresponding configurations and the description thereof is omitted.

In this embodiment, no spring is provided and the outer ring 40 is directly supported by the thrust bearing 23. And
The tip 40 a of the outer ring 40 is the end surface 14 of the shoulder portion 13.
It is arranged at a position retracted upward by a distance L.

At the time of joining, the end surface 14 of the shoulder portion 13
Since the work is pressed by, the shoulder part 1
The end surface 14 of No. 3 is buried to a position slightly lower than the work surface. At this time, the distance L is determined so that the outer ring tip 40a just contacts the surface of the work. That is, when a predetermined pressing force is generated at the time of joining, the outer ring tip 40a just comes into close contact with the work surface. By setting in this way, the outer ring 40 at the time of joining,
It is possible to prevent the base material from scattering and prevent the work surface from rising at the outer ring tip 40a.

FIG. 8 is an enlarged sectional view showing a rotor tip of a friction stir welding apparatus according to still another embodiment of the present invention. In this embodiment, the configuration other than the pin is the same as that of the friction stir welding apparatus 10 described above, so the same reference numerals are given to the corresponding configurations and the description thereof will be omitted.

In this embodiment, the shoulder 13 is provided with a ring portion 50 instead of the pin 15.
Reference numeral 0 denotes a cylindrical member projecting from the center of the end surface 14 of the shoulder portion.
3 is integrally formed. By using such a ring portion 50, the contact area with the work is increased as compared with the pin,
Stirring efficiency is improved.

Even with this pin-type friction stir welding apparatus, by providing the outer ring 20, it is possible to prevent scattering of the base material and swelling of the work surface during welding. Further, this ring-type friction stir welding apparatus is used for the outer ring 2
In addition to 0, the outer ring 30 shown in FIG. 6 and the outer ring 40 shown in FIG. 7 may be applied.

[0038]

As described above, according to the present invention, at the time of joining, the tip of the outer ring is brought into close contact with the surface of the article to be joined, and the joining point is confined by the outer ring, so that the base material is reliably prevented from scattering. . Further, by bringing the tip into contact with the surface of the article to be joined, it is possible to prevent the softened surface of the article to be joined from rising. As a result, it is possible to prevent a decrease in strength and improve aesthetics.

Further, since the thrust bearing is interposed between the outer ring and the rotor, the outer ring is rotatably supported and does not rotate when the tip of the outer ring is brought into contact with the surface of the object to be joined at the time of joining. You can by this,
It is possible to effectively suppress the swelling of the surfaces of the objects to be joined without damaging the work. Further, by arranging the tip of the outer ring at a position retracted from the shoulder surface, the tip of the outer ring can be reliably brought into close contact with the tip of the object to be joined at the time of joining without providing a spring or the like.

Further, according to the present invention, since the spring is interposed between the outer ring and the rotor, the outer ring which is in close contact with the objects to be joined can allow the rotor to move, and the joining is ensured during the joining. The joint part can be surrounded, and the base material can be prevented from scattering.

[0041]

[Brief description of drawings]

FIG. 1 is a diagram showing the vicinity of a rotor 11 of a friction stir welding apparatus 10 according to an embodiment of the present invention.

FIG. 2 is an enlarged sectional view showing the tip of the rotor 11.

FIG. 3 is a cross-sectional view showing a rotor tip at the time of joining.

FIG. 4 is a diagram showing a state at the time of joining.

FIG. 5 is a cross-sectional view showing works W1 and W2 after joining.

FIG. 6 is an enlarged cross-sectional view showing a rotor tip of a friction stir welding apparatus using an outer ring 30 integrated with a spring 31.

FIG. 7 is an enlarged cross-sectional view showing a rotor tip of a friction stir welding apparatus that does not use a spring.

FIG. 8 is an enlarged sectional view showing a rotor tip of a ring-type friction stir welding apparatus using an outer ring.

FIG. 9 is a sectional view showing a conventional rotor tip.

FIG. 10 is a view showing a bulge formed around a shoulder portion.

[Explanation of symbols]

10 Friction stir welding equipment 11 rotor 12 Rotor holding member 13 Shoulder 14 Shoulder end face 15 pin 20,30,40 outer ring 50 Ring part

─────────────────────────────────────────────────── ─── Continuation of front page (58) Fields surveyed (Int.Cl. ⁷ , DB name) B23K 20/12

Claims (5)

(57) [Claims] 1. A rotor rotating at a high speed is moved in the direction of the rotation axis to press the rotor tip against an article to be joined, and the contact portion between the rotor tip and the article is rotated by friction heat. In a friction stir welding device for softening and stirring to spot-join objects to be welded, a cylindrical shape that surrounds the rotor tip portion is provided on the rotor rotatably around a rotation axis, and at the time of joining, An outer ring that contacts the surface of the article to be joined, a thrust bearing is interposed between the base end of the outer ring and the rotor, and the outer ring does not rotate when the tip contacts the article to be joined. A friction stir welding device characterized by: 2. A rotor that rotates at a high speed is moved in the direction of the rotation axis to press the tip of the rotor against the article to be joined, and the contact portion between the tip of the rotor and the article to be joined is rotated by friction heat. In a friction stir welding device for softening and stirring to spot-join objects to be welded, a cylindrical shape that surrounds the rotor tip portion is provided on the rotor rotatably around a rotation axis, and at the time of joining, Has an outer ring that makes contact with the surface of the object to be joined, a thrust bearing is interposed between the base end portion of the outer ring and the rotor, and the outer ring does not rotate when the tip contacts the object to be joined. A friction stir welding apparatus characterized in that a substantially flat shoulder surface is formed at the rotor tip, and the outer ring is arranged at a position where the tip is retracted from the shoulder surface. 3. A rotor rotating at a high speed is moved in the direction of the rotation axis to press the rotor tip against an object to be joined, and the contact portion between the rotor tip and the object is rotated by frictional heat. In a friction stir welding device for softening and stirring to spot-join objects to be welded, a cylindrical shape that surrounds the rotor tip portion is provided on the rotor rotatably around a rotation axis, and at the time of joining, Has an outer ring that makes contact with the surface of the object to be joined, a thrust bearing is interposed between the base end portion of the outer ring and the rotor, and the outer ring does not rotate when the tip contacts the object to be joined. , The protrusion protrudes from the center of the rotor tip, and this protrusion
A friction stir welding apparatus, which is a pin or a cylindrical ring. 4. A spring is provided between the thrust bearing and the base end portion of the outer ring to elastically press the tip of the outer ring against the surface of the object to be joined at the time of joining. The friction stir welding apparatus according to one of the above. 5. The outer ring has elasticity in a rotation axis direction, and elastically presses the tip of the outer ring against the surface of the article to be joined at the time of joining. Friction stir welding apparatus as described in 1.