JP3045698B2 - Metal material joining method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of joining metal materials such as metal plates, extruded shapes, castings, and the like by friction stir welding.

[0002]

2. Description of the Related Art The following method has been proposed as a friction stir welding method, which is one of the solid-state welding methods. That is, FIG.
As shown in the figure, a large-diameter cylindrical rotor (11) and a pin-shaped small-diameter pin that is provided to protrude on the end axis of the rotor (11) and is harder than the metal materials (1) and (1). Probe (1
2) The joining portion (L) of the two plate-like metal materials (1) and (1) arranged in a butted state while rotating the rotor (11) at a high speed using a joining tool (10) having Alternatively, the probe (12) is inserted in the vicinity thereof. The probe (12) is inserted in the vicinity of the surface opposite to the surface of the metal material (1) (1) on the probe insertion side, that is, the butted portion (L).
Until it reaches the vicinity of the back surface. Usually, at this time, a shoulder (11) formed of a flat surface on the probe side of the rotor (11) is used.
a) is pressed against the surface of the butted portion (L) of both metal materials (1) and (1) on the probe (12) insertion side, that is, the upper surface of the butted portion (L). Then, the probe (12) is relatively moved along the butting portion (L) with the probe inserted. Frictional heat generated by the rotation of the probe (12),
Alternatively, the frictional heat generated due to the sliding between the shoulder (11a) of the rotor (11) and the two metal materials (1) and (1) causes
The two metal materials (1) and (1) are softened and agitated in the vicinity of the contact portion with the probe (12), and the softened and agitated portion reduces the traveling pressure of the probe (12) as the probe (12) moves. After receiving the plastic flow in a manner of wrapping backward in the traveling direction of the probe (12) so as to fill the passage groove of the probe, the frictional heat is rapidly lost, and the solidified material is cooled and solidified. This phenomenon is sequentially repeated with the movement of the probe (12), and finally the two metal materials (1) and (1) are joined and integrated at the butt portion (L). In the figure, (3) is a joint between the two metal materials (1) and (1) joined by the probe (12). Also,
Such a friction stir welding method is used not only for butt welding as shown in FIG.

According to the friction stir welding, since the solid-state welding is used, there is no restriction on the type of the metal material (1) or (1). Has the advantage that there is little deformation due to thermal distortion.

[0004]

However, in such friction stir welding, the probe (12) inserted and lifted up by the rotor (11) at the terminal end of the joining of the metal materials (1) and (1). When pulled out, a hole of the same diameter and the same depth as the probe will be created at the joint end,
The presence of the pull-up holes causes various problems in terms of application, and there is a problem that the commercial value is reduced due to deterioration of the appearance.

In order to close the pulling hole, a hole filling member may be embedded in the pulling hole.
In order to prevent the embedded filling member from inadvertently falling out of the lifting hole, the dimensional accuracy of the filling member must be set strictly. Special processing is required.

SUMMARY OF THE INVENTION The present invention has been made to solve such a problem, and it is possible to prevent a problem in application and a deterioration in appearance due to the presence of a pull-up hole in joining metal materials by friction stir welding. It is an object of the present invention to provide a method for joining metal materials, which can reduce the strictness of dimensional accuracy of the hole filling member.

[0007]

In order to achieve the above object, a method for joining metal materials according to the present invention is to relatively move a probe rotating along a joining line between metal materials in an inserted state. In friction stir welding in which both metal materials are joined and integrated, a rotating hole filling member is embedded in a pull-up hole generated by pulling up the probe at the welding end portion, and the rotation speed of the hole filling member is rapidly increased. , The hole filling member in the embedded state is torsionally broken and left on the metal material side.

According to this, the pull-up hole is closed by the insertion of the hole filling member, and it is possible to prevent the existence of the pull-up hole from hindering the application and deteriorating the appearance. Further, the torsional fracture of the hole filling member embedded in the pull-up hole is performed by torsional stress generated by rapidly changing the rotation speed of the hole filling member. Further, even when the hole filling member is not specially processed for finishing to the required dimensional accuracy, when the hole filling member is inserted into the pull-up hole, the hole filling member contacts the pull-up hole, and Due to wear and frictional heat caused by contact
Since the filling member and the pull-up hole are deformed to be compatible with each other, it is not necessary to strictly set the dimensions of the filling member.

[0009]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 2 shows the first embodiment, and FIG.
1 shows an embodiment.

FIG. 2 (i) shows a state in which the rotor (11) is pulled up at the joint end portion in the friction stir welding described with reference to FIG. 1 described above, and the joined aluminum or alloy thereof is shown. The metal plates (1) and (1) are formed with a pull-up hole (4) by pulling up the probe (12) of the inserted joining tool (10). Therefore, in this embodiment, in order to close the lifting hole (4), the same drawing (i)
As shown in i), a hole filling tool (20) having a hole filling member (22) that is embedded in the pulling hole (4) to close the pulling hole (4) is used.

The hole filling tool (20) is a welding tool (1) used for friction stir welding of the metal materials (1) and (1).
The probe (12) of (0) is replaced with the filling member (22). That is,
The joining tool (10) used at the time of joining includes a large-diameter cylindrical rotor (11) as shown in FIG.
It has a pin-shaped probe (12) smaller in diameter than the metal material (1) and (1). Then, the probe (1
2) projecting on the end axis of the rotor (11) into a mounting hole (11b) provided at the center of the flat end face of the rotor (11). 11) is attached so as to be rotatable integrally and detachably. In FIG. 1 (i), the metal materials (1) and (1) are friction stir welded by using the welding tool (10) having such a configuration, and the rotor (11) is pulled up at the welding end portion, so that the metal material (1) is lifted. )
(1) has a pull-up hole (4) for the probe (12). Then, in order to close the lifting hole (4), the probe (12) of the joining tool (10) is attached to the mounting hole (11).
b), the hole-filling member (22) is projected on the end axis of the rotor (11) into the vacant mounting hole (11b) so as to be integrally rotatable with the rotor (11) and The hole filling tool (2)
0) is configured. In addition, in the same figure (ii)-(iv), the code | symbol of the rotor (21) of the said hole filling tool (20) adds 10 to the number given to the rotor (11) of the said joining tool (10). It is indicated by the added number.

The hole filling member (22) is a pin having a small diameter made of the same material as the metal materials (1) and (1), and has a diameter equal to or larger than the diameter of the pull-up hole (4). It is set slightly larger so that it can be fitted or tightly fitted in the lifting hole (4). Further, a protruding length of the hole filling member (22) from an end flat surface of the rotor (21) is set to substantially the same length as a depth of the pull-up hole (4). ) Can be completely filled to the bottom. In addition, (21a) is a shoulder formed of a flat surface of the rotor (21).

The hole filling tool (20) configured as described above.
Then, the lifting hole (4) is closed as follows. That is, the rotor (21) is rotated at a predetermined rotation speed, for example, the same rotation speed as the rotation speed of the rotor (11) of the welding tool (10) when friction stir welding is performed, and rotates integrally therewith. The hole filling member (22) is embedded in the lifting hole (4). In the embedded state of the hole filling member (22), as described above, the projecting length of the hole filling member (22) is set to substantially the same length as the depth of the pull-up hole (4). As shown in (iii), the shoulder (21) of the rotor (21)
a) contacts the upper surface of the metal material (1) (1). Friction heat generated by rotation of the filled hole filling member (22), or frictional heat generated by sliding between the shoulder (21a) of the rotor (21) and the upper surface of the metal material (1) (1). Accordingly, the outer peripheral portion of the hole filling member (22) and the inner peripheral portion of the pull-up hole (4) of the metal material (1) (1) are softened and agitated in the vicinity of the contact portion. Then, in this state, the rotation of the rotor (21), that is, the rotation of the hole filling member (22) is stopped at a stroke. Then, the softening and stirring portion rapidly loses the frictional heat and is cooled and solidified. As a result, the filled hole filling member (22) is fixed to the lifting hole (4), and the filled hole member (22) is twisted. Under the stress, it is torsionally broken at the opening of the pull-up hole (4) and remains in the pull-up hole (4) as shown in FIG. Thus, the lifting hole (4) is closed. In (iv) of FIG.
2a) is a fracture surface of the hole filling member (22).

Next, the mounting hole (21) of the rotor (21) is
b) Remove the remaining part in the mounting hole (21).
By reattaching the probe (12) to b), the above-mentioned joining tool (10) can be reconfigured.

The metal plates thus joined (1) (1)
Since the pull-up hole (4) formed at the end of the joint is closed, the pull-up hole (4) does not hinder the application and does not deteriorate the appearance, and has high commercial value. Moreover, since the lifting hole (4) is closed by the hole filling member (22) made of the same material as the metal materials (1) and (1),
It has homogeneous physical and chemical properties. Also,
The torsion breaking of the filling member (22) embedded in the pull-up hole (4) is extremely simple because the torsion stress is generated by stopping the rotation of the filling member (22) at once. Further, the hole filling member (2) has a diameter slightly larger than the diameter of the lifting hole (4).
Even if the size of 2) does not exactly fit with the pull-up hole (4), the hole filling member (22) is inserted into the pull-up hole (4) while the hole filling member (22) is being inserted into the pull-up hole (4). 4)
The hole-filling member (22) and the pull-up hole (4) are deformed to fit each other due to wear and frictional heat generated by this contact. Therefore, it is necessary to set the dimensions of the hole-filling member (22) strictly. Disappears. Furthermore, in this embodiment, since the hole filling tool (20) is constituted by merely replacing the probe (12) of the welding tool (10) for performing friction stir welding with the hole filling member (22), one welding operation is performed. It can be operated on line.

In the second embodiment shown in FIG. 3, a hole filling tool (30) used to close the pulling hole (4) includes:
A cylindrical rotor (31) having the same diameter as the rotor (11) of the welding tool (10), and a small-diameter elongated rod filling member (32) made of the same material as the metal materials (1) and (1). ). The hole filling member (32) is provided with an insertion holding hole (31) provided on the internal axis of the rotor (31).
b) is inserted and held so as to protrude on the end axis of the rotor (31) so as to be integrally rotatable with the rotor (31) and protrude therefrom.

The pull-up hole (4) formed at the joint end of the metal material (1) (1) is closed by using the hole filling tool (30) in the same procedure as in the first embodiment. Can come off.
The hole filling tool (30) after closing the lifting hole (4) is in a state where the tip of the hole filling member (32) is torsionally broken and the hole filling member (32) projects from the rotor (31). However, by projecting the hole filling member (32) by a required amount, the state returns to the original state. As described above, the hole filling tool (30) can continuously supply the hole filling member (32), and can improve work efficiency.

The embodiments of the present invention have been described above.
The present invention is not limited to these embodiments.
For example, in these embodiments, the torsional breaking of the hole filling members (22) and (32) embedded in the pull-up holes (4) is performed by stopping the rotation of the hole filling members (22) and (32) at once. The point is that the rotation speed of the hole filling members (22) and (32) is rapidly changed to generate a torsional stress in the hole filling members (22) and (32) in the inserted state, and the hole filling members (22) and (32) are generated. 32) may be torsionally broken. Also,
In the above embodiment, the case where the metal materials (1) and (1) are butt-joined is shown. However, it is needless to say that the metal materials (1) and (1) may be joined by lap joint or T-joint joint.

[0019]

As described above, according to the method of joining metal materials according to the present invention, in the friction stir welding, a rotating hole filling member is buried in a pull-up hole generated by pulling up a probe at a welding end portion. At the same time, by rapidly changing the rotation speed of the hole-filling member, the hole-filling member in the inserted state is torsionally broken and left on the metal material side. It is possible to solve the problem that the commercial value is lowered due to the deterioration of the appearance or the deterioration of the appearance, and thus it is possible to obtain a joined product having both high strength reliability and high commercial value. Moreover, the torsional breaking of the filling member inserted into the pull-up hole can be performed only by suddenly changing the rotation speed of the filling member, so that it is extremely simple. Further, even when the hole filling member is not specially processed for finishing to the required dimensional accuracy, when the hole filling member is inserted into the pull-up hole, the hole filling member contacts the pull-up hole, and Wear and frictional heat caused by contact may cause the filling member and the pull-up hole to be deformed to fit each other, eliminating the need to strictly set the dimensions of the filling member and strict dimensional accuracy of the filling member. The nature can be eased.

[Brief description of the drawings]

FIG. 1 is a perspective view for explaining a friction stir welding method.

FIG. 2 shows one embodiment (first embodiment) of a method for joining metal materials according to the present invention, in which (i) is a longitudinal sectional front view in a state where a rotor of a welding tool is pulled up at a welding end portion; ) Is a vertical sectional front view of a state immediately before the hole filling member of the hole filling tool is inserted into the lifting hole, (iii) is a vertical sectional front view of the state where the hole filling member is embedded in the lifting hole, and (iV) is a lifting hole. FIG. 4 is a longitudinal sectional front view showing a state in which a hole filling member embedded in a hole is torsionally broken.

FIG. 3 is a view corresponding to FIG. 2 (ii), showing a hole filling tool used in another embodiment (second embodiment) of the joining method.

[Explanation of symbols]

 L: Butting portion (joining line) 1: Metal material 4: Pull-up hole 10: Joining tool 12: Probe 20, 30 ... Hole filling tool 22, 32 ... Hole filling member

────────────────────────────────────────────────── ─── Continued on the front page (58) Field surveyed (Int. Cl. ⁷ , DB name) B23K 20/12, 20/24 B23K 31/00 JICST file (JOIS) WPI / L (QUESTEL)

Claims (1)

(57) [Claims] 1. A joining line (L) between metal materials (1) and (1).
In the friction stir welding in which the probe (12) rotating along the shaft is relatively moved in the inserted state to join the two metal materials (1) and (1) together, the frictional stir welding is caused by pulling up the probe at the joint end. The rotating filling member (22) (32) is embedded in the lifting hole (4), and the rotation speed of the filling member is rapidly changed to thereby fill the filling member (22) ( 32) A method for joining metal materials, wherein the metal material (1) is left torsionally fractured to leave it on the metal material (1) side.