JP3947271B2 - T-joint forming method by friction stir welding - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method for forming a T-joint by friction stir welding, which is used for joining metal structural members such as aluminum.
[0002]
[Prior art]
As a method for joining metal structural members such as aluminum, there is a joining method called a friction stir welding method.
[0003]
In this friction stir welding method, structural members are solid-phase bonded to each other, and a rotor (1) as shown in FIG. 4 is used. In this rotor (1), a pin-like probe (3) having a diameter smaller than that of the cylindrical rotor main body (2) is coaxially projected at the tip shaft core portion of the cylindrical rotor main body (2). It is made of steel and other materials that are hard and have excellent heat resistance. Moreover, the predetermined | prescribed unevenness | corrugation is formed in the surrounding surface of the probe (3) so that a base material can be frictionally stirred effectively.
[0004]
As shown in FIG. 5, while joining the rotor (1) around its own axis, the tip of the pin-shaped probe (3) is joined to the butting boundary (8) of the workpiece (6) (7). ) In the pressed state, and the contact portion is softened and plasticized by the frictional heat. Then, the rotor (1) is further pressed against the workpieces (6) and (7), and the pin-like probe (3) is inserted in the thickness direction of the workpieces (6) and (7). The flat annular shoulder surface (4) at the tip of 2) is brought into contact with the workpieces (6) and (7) in a pressed state. Thereafter, the rotor (1) is moved along the abutting boundary portion (8) of the workpieces (6) and (7) while maintaining the state. At the butt boundary where the rotor (1) passes, the surrounding material is softened and agitated by frictional heat generated by the rotation of the rotor (1) and is applied to the shoulder surface (4) of the cylindrical rotor body (2). After the plastic flow so as to fill the passage groove of the pin-like probe (3) while the scattering is restricted, the heat is rapidly lost and it is solidified by cooling. Thus, the softening, adhesion deformation, stirring, and cooling and solidification of the material in the abutting portion (8) are sequentially repeated as the rotor (1) moves, and the workpieces (6) and (7) in the abutting portion (8). Are integrated with each other and sequentially joined.
[0005]
This friction stir welding method directly joins the workpieces (6) and (7) in a softened state without melting the material, and there is no problem in quality due to the thermal effect as in the case of welding. In addition, a high-quality and strong joint (12) can be formed, and the use of the rotor (1) as described above makes it possible to form the joint (12) with a clean and clean appearance without irregularities. Can do.
[0006]
[Problems to be solved by the invention]
However, in the friction stir welding method as described above, in the case of a T-joint type in which fillet welding is performed according to welding, it is practically very difficult to cause a rotor to act on a corner surrounded by a right-angle wall. Therefore, fillet joining by the friction stir welding method is difficult. Therefore, until now, the friction stir welding method has used the workpieces (6) ( 7) It was used only in the case where they were butted and joined so as to be flat.
[0007]
An object of the present invention is to establish a method of forming a T-joint by friction stir welding in order to expand the application range of the friction stir welding method in the above technical background.
[0008]
[Means for Solving the Problems]
The said subject combines a 1st workpiece | work and a 2nd workpiece | work in T shape, makes a rotor act from the back part side of the 1st workpiece | work used as both arms, and friction stir welding the 1st workpiece | work and a 2nd workpiece | work. This is solved by a method of forming a T joint by friction stir welding.
[0009]
That is, since the back side of the first workpiece is flat, it is easy to allow the rotor to act on the first workpiece. In this manner, the work is friction stir welded by causing the rotor to act from the back side of the first work and softening, stirring, and cooling the material at the boundary between both works, and a firm T joint is formed. The
[0010]
Moreover, since the friction stir welding is performed by softening the material without melting it as described above, even if the rotor is operated from the back side of the first workpiece, the first workpiece is bonded. There is no problem of quality deterioration due to large shape defects or thermal effects, and a high quality T joint with good shape accuracy can be obtained.
[0011]
As the rotor, for example, a pin-like probe having a diameter smaller than that of the columnar rotor main body and coaxially protruding from the tip axial core portion of the columnar rotor main body can be used. In this case, even in the formation of the T joint, it is possible to prevent the softening material from scattering on the shoulder surface of the cylindrical rotor body of the rotor, and to make the passage of the rotor clear and clean and have a clean appearance. it can.
[0012]
Moreover, in the said formation method, it is preferable that a recessed part is provided in the abdominal part side of a 1st workpiece | work, a 2nd workpiece | work is fitted in this recessed part, and friction stir welding is performed. Both workpieces can be easily combined with each other in a fixed and positioned state, a relative displacement during joining can be prevented, and a T joint with excellent combination accuracy can be obtained.
[0013]
DETAILED DESCRIPTION OF THE INVENTION
Next, embodiments of the present invention will be described with reference to the drawings.
[0014]
In the first embodiment (reference form) shown in FIG. 1, as shown in FIG. 1 (a), the first work (6) (7) is a horizontally oriented first work (6). 14) The upper edge part of the second workpiece (15) oriented vertically is simply combined with the middle part in the width direction of 14) in a T-shape. The rotor (1) is applied to the combined workpieces (14) and (15) from the back side of the first workpiece (14) as shown in FIG. When the pin-like probe (3) of the rotor (1) is inserted into the material, the tip of the pin-like probe (3) reaches the thickness of the second workpiece (15). It is preferable from the viewpoint of improving the strength. The arms (14a) (14a) of the first workpiece (14) are preferably supported by jigs (16) (16) from below. This jig (16) can prevent the deformation of the first workpiece (14) due to the softening of the material at the time of joining. As described above, the workpieces (14) and (15) are firmly joined and integrated by friction stir welding.
[0015]
In the second embodiment shown in FIG. 2, a fitting groove (17) as a recess is provided in the middle portion in the width direction on the abdomen side of the first workpiece (14), as shown in FIG. The upper edge of the second workpiece (15) is fitted into the fitting groove (17) to combine the workpieces (14) and (15). By adopting such a fitting form, both the workpieces (14) and (15) can be easily fixed and combined with each other in a positioning state, and a relative displacement during joining can be prevented, and the shape accuracy is excellent. A T-joint can be obtained.
[0016]
In the third embodiment shown in FIG. 3, as shown in FIG. 3A, both works (14) and (15) are made of a slice cut product of an aluminum extrusion mold, and the abdomen of the first work (14). The fitting groove (17) formed in the intermediate portion in the width direction on the side is extruded so as to extend in the depth direction, and the circumferential wall surface surrounding the groove (17) has no corner in the circumferential direction. Extruded on a smooth surface. Correspondingly, the upper edge of the second workpiece (15) is extruded into a smooth outer peripheral shape corresponding to the inner peripheral shape of the fitting groove (17). The one end of the first work (14) is slidably fitted through one end of the fitting groove (17) to be fitted into the fitting groove (17) in an adapted state. . By adopting the combination structure as in this embodiment, not only can the fixing and positioning functions of both workpieces be improved, but also cracking and breakage due to stress concentration on the mating part is prevented, making it extremely strong. T-joints that are strong against
[0017]
As mentioned above, although embodiment of this invention was shown, this invention is not limited to these embodiment, A various change is possible. For example, the structure of the rotor (1) may be any structure that allows the workpieces (14) and (15) to be solid-phase bonded by friction stirring, and various structures may be used. The workpieces (14) and (15) may be made of various metal materials and other materials in addition to the aluminum material. Further, in addition to a T-joint structure composed of flat plates, the present invention can be applied to the formation of various T-joint structures such as fillet welds according to welding, such as a T-joint structure composed of flat plates and aggregates.
[0018]
【The invention's effect】
As described above, the T-joint forming method of the present invention combines the first work and the second work in a T shape, and causes the rotor to act from the back side of the first work serving as both arms. And the second workpiece are friction stir welded, making it easy to actuate the rotor, and softening, stirring and cooling the material at the boundary between the two workpieces to firmly stir both workpieces T-joints that are excellent in strength can be formed, and the application range of the friction stir welding method can be expanded. Further, in the case of fillet welding, two welding lines are usually required on both sides, but in the method of the present invention, a single bonding line may be used in the center, and productivity can be improved. Moreover, since the friction stir welding is performed by softening the material without melting it as described above, even if the rotor is operated from the back side of the first workpiece, the first workpiece is bonded. There is no problem of quality deterioration due to large shape defects or thermal effects, and a high quality T joint with good shape accuracy can be obtained.
[0019]
In addition, when using a rotor in which a pin-like probe having a diameter smaller than that of the columnar rotor main body is coaxially projected at the tip axial core portion of the columnar rotor main body, Also in the formation, it is possible to prevent the softening material from being scattered on the shoulder surface of the cylindrical rotor body of the rotor, and to make the passage trace of the rotor clear and clean with no irregularities.
[0020]
In the above forming method, a recess is provided on the abdomen side of the first workpiece, and the second workpiece is fitted into the recess to perform friction stir welding, thereby fixing and positioning the two workpieces to each other. The T-joint can be easily combined with the state, the relative displacement during joining can be prevented, and the combination accuracy is excellent.
[Brief description of the drawings]
FIG. 1 shows a first embodiment (reference form) , in which FIG. (A) is a sectional front view showing a combined state of workpieces, and (B) is a sectional front view during friction stir welding.
FIG. 2 shows a second embodiment, in which FIG. (A) is a sectional front view showing a combined state of workpieces, and (b) is a sectional front view during friction stir welding.
FIG. 3 shows a third embodiment, in which FIG. (A) is a sectional front view showing a combined state of workpieces, and (b) is a sectional front view during friction stir welding.
FIG. 4 shows a rotor used for friction stir welding, where FIG. (A) is a side view and FIG. (B) is a front end view.
5A and 5B show a conventional friction stir welding method, in which FIG. 1A is a cross-sectional front view of workpieces being joined, and FIG.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Rotor 2 ... Rotor main body 3 ... Probe 14 ... Work 15 ... Work 17 ... Fitting groove (recess)

Claims (4)

The first work and the second work are combined in a T-shape, the rotor is operated from the back side of the first work serving as both arms, and friction stir welding is performed by friction stir welding to join the first work and the second work. A method for forming a joint, comprising:
A method of forming a T joint by friction stir welding, wherein a recess is provided on the abdomen side of the first work, and the second work is fitted into the recess to perform the friction stir welding.   The method for forming a T joint by friction stir welding according to claim 1, wherein a fitting groove is provided as the recess.   The method for forming a T joint by friction stir welding according to claim 1 or 2, wherein both arms of the first workpiece are supported by a jig from below.   4. The rotor according to claim 1, wherein a pin-like probe having a diameter smaller than that of the cylindrical rotor main body is coaxially projected from a tip axis portion of the cylindrical rotor main body. A method for forming a T joint by friction stir welding according to one item.

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