JP3268207B2 - Friction welding 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 friction welding method utilizing plastic flow caused by frictional heat between a rotary tool and a workpiece, and is used for all structures such as vehicles, automobiles, ships, aviation, elevators, pressure vessels and the like. it can.

[0002]

2. Description of the Related Art Japanese Patent Laid-Open No. 5-963 discloses a friction welding method.
No. 85 is known. Conventional friction welding methods rotate the workpiece to be welded or both. For this reason, there are limitations on the shape and dimensions of the workpiece to be welded.

On the other hand, as a method for continuously friction welding in the longitudinal direction of a workpiece, Japanese Patent Application Laid-Open No. 7-505090 discloses that a tool made of a material substantially harder than the workpiece is used. insert the weld, the, by moving while rotating the tool, the welding method of welding a workpiece by plastic flow due to friction heat generated between the workpiece and the 該回 rolling tool are known.

In the conventional friction welding method, the workpieces are rotated and the workpieces are welded by frictional heat. On the other hand, Japanese Patent Publication No. 7-505050 discloses a method in which a welding member is fixed. The joining can be performed by moving the tool while rotating it. Therefore, there is an advantage that even a member that is substantially infinitely long in the welding direction can be continuously solid-phase bonded in the longitudinal direction. Furthermore, since the solid-state joining is performed by utilizing the plastic flow of the metal due to frictional heat between the rotating tool and the welding member, joining can be performed without melting the joint. Also,
Since the heating temperature is low, deformation after bonding is small. Since the joint is not melted, there are many advantages, such as fewer defects.

[0005]

SUMMARY OF THE INVENTION The above-mentioned Japanese translation of PCT application No. Hei 7-50
The rotary tool according 5090 JP inserted into the workpiece, when applying the method of welding by moving while rotating the 該回 rolling tool products, have the following problems.

[0006] (1) the welding method, the end position of the weld, or, position escape from the welding, that is, to stop the rotation of the rotary tool, the portion withdrawn 該回 rolling tool from the weld A cavity of approximately the same shape as the rotating tool results. That is, since the cavity remains as a defect in the processed member, there is a problem in reliability when applied to a structure.

(2) The above-mentioned welding method requires a support jig for supporting a workpiece on the opposite side (the back side of the welded portion) of the rotary tool. If the workpiece is long, the workpiece is deformed, such as by welding heat, the back surface of the pressurized Engineering was sometimes away from the fixture. In this case, the workpiece cannot withstand the load of the rotating tool, and a defect occurs at that portion.

( 3 ) The thickness of the joint is locally reduced by the cutting action of the rotating tool. That is, the surface of the welded portion is dented by friction with the rotating tool.
For this reason, since the thickness of the joint is substantially reduced, the strength of the weld is reduced. Therefore, there is a problem in the reliability of the workpiece joined by this welding method.

( 4 ) If there is a gap in the joint at the joint, a defect is likely to occur.

An object of the present invention is to easily repair defects caused by friction welding.

[0011]

Above object to an aspect of the said member and the member of the cavity portion into the cavity substantially the same shape produced welds arranged and placed in the cavity by friction welding
After fixing to the workpiece by welding, welding is again performed by the friction welding method described above.

[0012] [Operation] Place a repair section in the cavity of the friction welding unit (defect), the
After fixing the repair member to the workpiece, friction welding is performed again, so that defect-free friction welding can be performed.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiment 1 FIG. 1 is a perspective view showing a case where a workpiece 4 is welded by moving a rotary tool 1 in a direction 3 while rotating a rotary tool 1 in a direction 2 by the welding method. Show. FIG. 2 is a cross-sectional view illustrating an example of a welding defect generated in the welded portion 5 of FIG.

FIG. 3A is a cross section taken along the line AA in FIG.
The defect 6 in this case is likely to occur at the end of the weld or at the position where welding is stopped. The shape of the defect 6 is a cavity having substantially the same shape as the tip of the rotating tool. (B) is a cross section taken along the line BB. The defect 7 in this case is likely to occur when welding conditions are not appropriate. This defect 7 occurs almost continuously from the welding start point to the welding end point, and can often be visually observed from the surface of the welded portion. (C) is a cross section of the CC section, and the defect 8 in this case is also a defect that occurs when the welding conditions are inappropriate. The defect 8 often occurs discontinuously inside the weld.

The present invention resides in that a member having the same shape as each of the above-mentioned defects is inserted into each of the defective portions shown in FIG. 3 and welding is performed again by the above-mentioned welding method. Next, this embodiment will be described specifically. FIG.
Since the defect 6 in (a) is a columnar cavity, a member 9a having the same shape is inserted into this cavity. Since the defect 7 in (b) is a rectangular elongated cavity, a part of the defect is processed, and a member 9b having substantially the same shape as this is inserted.
In this case, since the inserted member is long,
It is fixed to the workpiece by welding.

Since the defect 8 in (c) occurs inside the welded portion, it is mechanically cut from the front or back surface of the welded portion to the position of the defect, and the hollow portion including the cut portion is mechanically cut. A member 9c having the same shape as the above is inserted.

As described above, after a member having the same shape as each defect is inserted into each defective portion (hollow portion), welding is performed again by the above-described welding method from the rear side of the position where the member is inserted.

The member to be inserted into the defective portion is desirably the same material as the processed member.

The length of the aluminum alloy in this embodiment is 5
m, thickness: 4 mm, width: 0.5 m, and welding conditions: the tip diameter of the rotating tool: 5 mm, the number of rotations: 1000 rpm, and the welding speed: 0.2 m / min. By the above method, a highly reliable welded portion was obtained, and this was applied to welding of railway vehicles.

Reference Example 1 FIG. 4 is a perspective view showing a method of fixing an insertion member by a roller mechanism.
FIG .

The present invention is for mechanically fixing the member 9 inserted into the defective portion by the roller 10. That is, when the defect is long in the welding direction, the insertion member 9 is pressed against the processing member 4 by the roller 10 in front of the rotary tool 1 with respect to the welding direction. Thereby, the insertion member 9 is fixed immediately before the rotating tool 1. The roller 10 moves in the welding traveling direction 3 in conjunction with the rotary tool 1.

On the other hand, the roller 10 has a mechanism 11 which can move up and down independently of the rotary tool 1 to follow the deformation of the processing member 4.
Is provided. The pressing force of the roller in this case is about 5
00 kg. The welding conditions and the dimensions of the processed members are those of the first embodiment.

REFERENCE EXAMPLE 2 FIG. 5 shows a method of joining honeycomb panels made of a face plate 12 and a core material 13 manufactured by extrusion, in which a rotary tool 1 is inserted into a portion of an edge material 14 and welded. Thus, a large honeycomb structure is manufactured by combining a plurality of honeycomb panels. In the present reference example, the thickness of the edge material of the welded portion where the rotary tool 1 contacts is increased by 1 mm. The width is 20 mm, which is almost the same as the outer shape of the rotating tool. Due to the shape of the welding portion, the strength does not substantially decrease even when the rotating tool 1 causes a dent in the joining portion. Furthermore, even if the gap at the joint is large, joining can be performed without defects. For this reason, a structure made of a highly reliable honeycomb panel can be manufactured efficiently and at low cost.
A high-speed vehicle was manufactured using this honeycomb panel as a railway vehicle body.

Reference Example 3 FIG. 6 shows a joint structure of a joint according to the present invention. FIGS. 6A and 6B show a joint structure in which the processing member 4 has an I-shaped groove.
(C) and (d) show the joint structure of a V-groove, and (e) and (f) show the joint structure of a V-groove. As shown in FIG. 6, by locally increasing the thickness of the welded portion, in the case of an I-shaped groove, welding can be performed without defects even when the gap is large.

[0025] In this reference example, when the thickness of the workpiece is welded to 5mm aluminum alloy I die opening destination (a), the gap of the groove can be welded without defects to 1 mm. further,
In the case of the C-grooves (c) to (d) and the V-grooves (e) and (f), the joint thickness is increased by increasing the thickness of the welded portion. To fill up the space in the gap, so that welding can be performed without defects.

REFERENCE EXAMPLE 4 FIG. 7 is a perspective view of the opposite side of the rotary tool 1, that is, the back side of the welding surface, in which the support jig 15 of the workpiece 4 having the rotation mechanism is arranged and welded. The workpiece 4 is fixed to a fixed base 16 and further supports the workpiece on the opposite side of the rotary tool so as not to be deformed by the load of the rotary tool 1. In this case, by providing the support jig 15 with a rotation mechanism, it can be operated with little frictional resistance with the workpiece. Support jig 15
Is linked to the movement of the rotating tool 1 in the welding direction 3 and
It moves in 18 directions while rotating in the direction. The support jig 15 also has a mechanism capable of automatically moving in the up-down direction 19 and the left-right direction 20 following the deformation of the workpiece 4 in the up-down direction or the left-right direction. Butt welding of an aluminum alloy having a length of 20 m, a width of 1 m, and a thickness of 5 mm was performed by a support jig 15 having a mechanism for moving vertically and horizontally in addition to the rotating mechanism. The welding conditions are the same as in the first embodiment.
By this welding, a high-speed vehicle was manufactured.

In the fourth embodiment , the work is fixed and the rotary tool 1 and the support jig 15 are moved in the welding direction. However, the object can also be achieved by fixing the work and moving the work.

Reference Example 5 FIG. 8 is a sectional view showing a method for welding an aluminum alloy for a railway vehicle according to the present invention.

The workpiece in the present reference example has a length of 20 m,
It is an aluminum alloy plate having a thickness of 5 mm and a width of 500 mm. In addition, the height of the joint of the processing member is about 1 mm from other parts.
Is getting higher. The rotary tool 1 is attached to a mobile robot 21 and moves while rotating while being inserted into a welded portion of the processing member 4. In this case, a support jig 15 is arranged on the opposite side of the rotary tool 1. The support jig 15 has at least one of the functions of rotation, up, down, left, and right as in the fifth embodiment. On the other hand, the processing member 4 is fixed by fixing jigs 22 and 23 from above and below. In addition, this fixing jig 22 is for stably fixing a long processing member.
It has the same rotation mechanism as the support jig 15. The book
In the reference example, the processing member was fixed by the above-described method, and the rotary tool and the support jig were moved to perform welding under the same conditions as in the first embodiment.

FIG. 9 shows a vehicle structure manufactured according to the reference example. FIG. 10 is a perspective view of a railway vehicle in which the vehicle structure of FIG. 9 is further assembled by the welding method of the present invention. Although a part of the length of the joint 5 is 12.5 m, a maximum length of 25 m is formed from both front and back surfaces, and a railway vehicle is manufactured.

(1) A member having the same shape as the cavity is inserted into a defective portion (cavity) of the welded portion, and welding is performed again. In this case, since the member arranged in the cavity may move during welding by the rotating tool, it is desirable to fix the member in front of the rotating tool.

(2) The support jig for the workpiece arranged on the opposite side of the rotary tool has a rotary mechanism. further,
The workpiece fixing jig provided with the rotation mechanism moves in the vertical and horizontal directions following the deformation of the workpiece.

(3) The thickness of the joint of the processed member is locally higher than the thickness of the other parts.

[0034]

According to the present invention, a repair member is disposed in a cavity (defect portion) of a friction welding portion , and the repair member is used as a work piece.
Since it is fixed by welding and friction welding is performed again, friction welding without defects can be performed.

[Brief description of the drawings]

FIG. 1 is a schematic view of a friction welding method.

FIG. 2 is a diagram showing a defect when a friction weld is viewed from above.

FIG. 3 is a cross section at each position in FIG. 2;

FIG. 4 is a perspective view showing friction welding.

FIG. 5 is a longitudinal sectional view of a friction joint.

FIG. 6 is a longitudinal sectional view showing various types of joints.

FIG. 7 is a perspective view of a friction welding device.

8 is a longitudinal sectional view of a main part of FIG. 7;

FIG. 9 is a perspective view of a structure of a railway vehicle.

FIG. 10 is a perspective view of a vehicle body of a railway vehicle.

[Explanation of symbols]

1: rotating tool, 6, 7, 8: defect, 9a, 9b, 9
c: Repair member.

──────────────────────────────────────────────────続 き Continued on front page (72) Inventor Kinya Aota 794, Higashi-Toyoi, Kazamatsu, Kudamatsu-shi, Yamaguchi Prefecture Inside the Kasado Plant of Hitachi, Ltd. Inside the Kasado Plant (72) Inventor Yasuo Ishimaru 794, Higashi-Toyoi, Kazamatsu City, Yamaguchi Prefecture Inside the Kasado Plant, Hitachi, Ltd. (56) References JP-A-4-75726 (JP, A) 15542 (JP, B1) C.I. J. Dawes, An Introduction to Friction on Stil Welding and It's Development, Welding & Metal Fabrication, UK, International Trade Day, Vol. 13-14, 16, NDL accepted on February 13, 1995 J. Dawes & W. M. Thomas, Friction Sir Process Welds Aluminum Alloys, Welding Journal, United States, American Welding Society, May 13, 1996, Vol. 75, No. 3, National Institute of Health Sciences, Vol. (58) Field surveyed (Int.Cl. ⁷ , DB name) B23K 20/12

Claims (2)

(57) [Claims] 1. A method of inserting a rod-shaped rotary tool, which is made of a material substantially harder than a workpiece, into a joint of the workpiece and moving the tool while rotating the tool, the rotary tool and the workpiece being generated. In a friction welding method utilizing plastic flow due to frictional heat, a member having substantially the same shape as the cavity is disposed in a cavity formed in a welded portion by friction welding, and the member disposed in the cavity is subjected to the processing. Weld to object
And then re-welding by the friction welding method. 2. The workpiece according to claim 1, wherein said member and said workpiece are provided.
Wherein said welding is performed by TIG welding .