JP7482675B2 - Friction stir welding attachment, friction stir welding head, friction stir welding device, and friction stir welding method - Google Patents

Description

The present invention relates to a friction stir welding attachment, a friction stir welding head, a friction stir welding device, and a friction stir welding method.

Friction stir welding is used as a method for joining materials.
In friction stir welding, in order to obtain sufficient frictional heat, a high torque is required for rotating the welding tool, and thus a dedicated friction stir welding device has been used in the past. On the other hand, a general-purpose machine tool can be used as the friction stir welding device if it can obtain a high torque (see Patent Document 1).
In the above-mentioned Patent Document 1, the rotation axis of the welding tool is disposed perpendicular to the surfaces of the workpieces to be welded. In contrast, the rotation axis of the welding tool is tilted and the tip side of the tool is displaced forward in the direction of movement, thereby improving the penetration into the workpieces and the ability to hold down the softened material.
Such an inclined posture of the rotation axis of the welding tool can be achieved by providing a tilting mechanism including a bending joint in a friction stir welding head including the welding tool or in a friction stir welding attachment to which the welding tool can be attached, or by adjusting the spindle of the machine tool to an inclined state.

JP 2017-127881 A

In the above-mentioned Patent Document 1, the weld line of the materials to be friction stir welded is a straight line, and the rotating welding tool is moved along this weld line.
In response to this, there is a demand for friction stir welding for more complicated shapes, such as weld lines that bend midway or curved weld lines.
However, in friction stir welding of a bending or curved weld line, there is a problem in that the above-mentioned method of tilting the welding tool cannot be applied as is.

That is, when performing friction stir welding on a bending or curved weld line, the rotating welding tool is moved along the weld line. For example, when performing friction stir welding along the weld line in the X-axis direction, the welding tool is moved in the X-axis direction with the rotation axis of the welding tool tilted in the X-axis direction.
If the welding line were to be bent at a right angle, the moving direction of the welding tool could be easily changed by the operation program, but the tilted attitude of the rotation axis of the welding tool could not be changed, resulting in a problem that the rotation axis of the welding tool would remain tilted toward the X-axis direction when the welding tool moves in a direction perpendicular to the X-axis.
In order to avoid such inconvenience, it has been required to be able to easily change not only the moving direction of the welding tool but also the tilt direction of the welding tool.

Furthermore, in addition to friction stir welding of the top surface of a workpiece, there is a demand for friction stir welding of the side surface of the workpiece. For friction stir welding of such side surfaces, in addition to a method in which the spindle is directly facing the side surface, a method in which an angle head and a welding tool are attached to a vertical spindle and the orientation of the welding tool is changed according to the orientation of the side surface is used. However, there are inconveniences such as the position control of the machine tool becoming complicated in order to change the orientation of the spindle and the angle head.
Even in such friction stir welding of the side surfaces of a workpiece, there was a demand for the angle head to be able to be oriented easily.

The object of the present invention is to provide a friction stir welding attachment, a friction stir welding head, a friction stir welding device, and a friction stir welding method that can easily change orientation.

The friction stir welding attachment of the present invention is
A main body to be attached to a spindle of a machine tool;
a processing shaft that is rotatably supported by the main body and to which a joining tool can be attached;
and a rotation drive unit that rotates the processing shaft.

In the present invention, a welding tool is attached to the processing shaft, and a main body is attached to the spindle of a machine tool. In the main body, the processing shaft and welding tool are rotated by a rotary drive unit, and the rotating welding tool is brought into contact with a workpiece, thereby performing friction stir welding of the workpiece. In this case, the rotary drive unit can be an air motor or the like that is driven by center-through air from the spindle, and is not dependent on the rotation of the spindle.
On the other hand, by rotating the spindle, the main body rotates together with the spindle, and the orientation of the processing axis and the joining tool in the main body can be changed.
This makes it possible to easily change the orientation, such as the tilt direction, of the welding tool by rotating the main shaft.

In the friction stir welding attachment of the present invention,
The rotary drive unit is preferably an air motor that is rotated by air supplied through the axis of the main shaft.
In the present invention, by using air from the main shaft, there is no need to supply external power, and a power source can be easily secured.
The power source for the rotation drive unit may be an electric motor that receives power from the spindle head via a fixed unit.

The friction stir welding attachment of the present invention is
The processing shaft is preferably arranged coaxially on the axis of the main shaft.
In this case, the processing axis is not completely coaxial with the axis of the main spindle, but can be inclined at a predetermined angle with respect to the axis of the main spindle.
In the present invention, the orientation of the main body is changed by the main shaft, so that the orientation of the processing axis and the joining tool, for example the inclined orientation of the joining tool, can be changed to any orientation.
Furthermore, if the processing axis is coaxial with the axis of the spindle, only the axial position of the joining tool is different from when the joining tool is directly attached to the spindle, and the position relative to the workpiece surface is the same. Therefore, the control program for when the joining tool is directly attached to the spindle can be used with only minimal changes, such as numerical corrections in the axial direction.

The friction stir welding attachment of the present invention is
The processing axis is preferably disposed in a direction intersecting with the axis of the main spindle.
In the present invention, for example, by mounting the machine tool on a vertical spindle, the machining shaft and the welding tool can be supported in the horizontal direction, and friction stir welding can be performed on the side surface of the workpiece. The orientation of the machine tool can be changed by changing the orientation of the main body using the spindle.

The friction stir welding attachment of the present invention is
It is preferable that the machining axis is positioned in a direction intersecting the axis of the main shaft so that when the joining tool is attached to the machining axis, the machining portion of the joining tool is on the axis of the main shaft.
In the present invention, the machining portion of the welding tool is on the axis of the spindle regardless of the orientation of the spindle or welding tool. Therefore, regardless of the orientation of the welding tool, it is easy to specify the machining position for the workpiece and to create a control program.

The friction stir welding head of the present invention is
The friction stir welding attachment of the present invention described above;
and the welding tool attached to the friction stir welding attachment.
In the present invention, the same effects as those of the above-mentioned friction stir welding attachment of the present invention can be obtained.

The friction stir welding apparatus of the present invention is
The friction stir welding attachment of the present invention described above;
The welding tool attached to the friction stir welding attachment;
and a machine tool to which the friction stir welding attachment is attached.
In the present invention, the same effects as those of the above-mentioned friction stir welding attachment of the present invention can be obtained.

The friction stir welding method of the present invention comprises the steps of:
Using the above-mentioned friction stir welding apparatus of the present invention,
The rotation drive unit rotates the welding tool to perform friction stir welding on the workpiece,
The orientation of the joining tool is changed by rotating the main shaft.
In the present invention, the same effects as those of the above-mentioned friction stir welding attachment of the present invention can be obtained.

The present invention provides a friction stir welding attachment, a friction stir welding head, a friction stir welding device, and a friction stir welding method that can easily change orientation.

1 is a perspective view showing a friction stir welding apparatus according to a first embodiment of the present invention; FIG. 2 is a side view showing the friction stir welding attachment according to the first embodiment. 5A to 5C are schematic diagrams showing a direction changing operation of the first embodiment. FIG. 5 is a side view showing a friction stir welding attachment according to a second embodiment of the present invention. 13A to 13C are schematic diagrams showing a direction changing operation of the second embodiment. FIG. 11 is a side view showing a friction stir welding attachment according to a third embodiment of the present invention. FIG. 13 is a side view showing a friction stir welding attachment according to a fourth embodiment of the present invention.

Hereinafter, a first embodiment of the present invention will be described with reference to the drawings.
In FIG. 1, a friction stir welding apparatus 1 of this embodiment is configured by mounting a friction stir welding attachment 10 based on the present invention and a general-purpose welding tool 20 for friction stir welding on a general-purpose machine tool 2 having a vertical spindle.

The machine tool 2 includes a table 3 on which a workpiece 9 is fixed, a spindle 4 to the tip of which a tool can be attached, a spindle head 5 that supports the spindle 4 so that it can rotate freely, and a moving mechanism 6 that moves the spindle head 5 to any position.
The movement mechanism 6 has a slider 62 supported by a horizontal guide bar 61, and the spindle head 5 is supported facing downward by the slider 62. Therefore, by raising and lowering the spindle head 5 relative to the slider 62, the tip of the spindle 4 can be moved to a specified position in the Z-axis direction. Also, by moving the slider 62 along the guide bar 61, the tip of the spindle 4 can be moved to a specified position in the X-axis direction.

The spindle 4 has an axis R that is vertical (Z-axis direction), and can be rotated around the axis R (C-axis direction) by a drive motor in the spindle head 5 and can be stopped at a specified angular position.
The table 3 can be rotated around a vertical axis (C-axis direction) by a drive mechanism installed on the bed 7, and can be stopped at a specified angular position.
The table 3, the spindle 4, the spindle head 5 and the moving mechanism 6 are all mounted on the upper surface of a bed 7, and the whole can be enclosed by a cover 8 which can be opened and closed freely.

A welding tool 20 is attached to the spindle 4 via a friction stir welding attachment 10 based on the present invention. Here, by attaching the welding tool 20 to the friction stir welding attachment 10, the friction stir welding head 19 of the present invention is formed.

In FIG. 2, the friction stir welding attachment 10 has a main body 11 that is attached to the spindle 4 of the machine tool 2, a processing shaft 14 that is rotatably supported by the main body 11 and to which a welding tool 20 can be attached at its tip, and a rotation drive unit 15 that rotates and drives the processing shaft 14.

The main body 11 can be attached to the spindle 4 by a standard-based tapered shank 111 and has a center through hole 112 along the axis, through which center air can be supplied from the spindle 4 .
The rotary drive unit 15 is constituted by an air motor that is rotated by high-pressure air, and can be rotated by center through air supplied from the main shaft 4 via a center through hole 112.

In the main body 11 , the processing shaft 14 and the rotary drive unit 15 are installed at an angle to the axis R of the main spindle 4 .
The rotation axis Cc of the machining shaft 14 and the rotation drive unit 15 is inclined at an angle At of approximately 0 to 5 degrees relative to the main body 11, and the side where the tip side of the rotation axis Cc is inclined is the front side Dc of the friction stir welding attachment 10.
The tip (lower end in the figure) of the processing shaft 14 is exposed from the end face of the main body 11, and a joining tool 20 is attached to the tip.

Therefore, in the friction stir welding attachment 10 of this embodiment, by supplying center-through air from the spindle 4 through the center through hole 112 to the rotation drive unit 15, the processing shaft 14 and the welding tool 20 are rotated by the rotation drive unit 15 (rotational operation Rc), and friction stir welding of the workpiece 9 can be performed by the welding tool 20.
On the other hand, by rotating the main body 11 using the main shaft 4 (rotational motion Rs), the orientation of the front side Dc of the friction stir welding attachment 10 can be changed in accordance with the moving direction of the welding tool 20 .

In FIG. 3, for example, when the workpiece 9 has bent weld lines 91, 92, the direction of the front side Dc of the friction stir welding attachment 10 is changed at the intersection position.
First, the welding tool 20 is moved in the welding direction D1 along the welding line 91 while being rotated (rotational motion Rc). At this time, the friction stir welding attachment 10 faces its front side Dc in the welding direction D1. In this state, the rotation axis Cc of the welding tool 20 is inclined by an angle At with respect to the axis R of the spindle 4, and the tip of the welding tool 20 is inclined in the welding direction D1, which is the front side Dc.

When the joining tool 20 reaches the intersection of the joining line 91 and the joining line 92, the friction stir welding attachment 10 is rotated (rotational motion Rs) by the main shaft 4, and the direction of the angle Ar is changed so that the front side Dc faces the joining direction D2 of the joining line 92.
As a result, the tip of the welding tool 20 is inclined in the welding direction D2 while the rotation axis Cc of the welding tool 20 remains inclined at the angle At with respect to the axis R of the spindle 4. Therefore, even if the welding direction D1 is changed to the welding direction D2, the front side Dc which is the inclination direction of the welding tool 20 can always be directed in the movement direction, and friction stir welding of the workpieces 9 can be performed appropriately.

According to this embodiment, the following effects can be obtained.
In this embodiment, a welding tool 20 is attached to the processing shaft 14 of the friction stir welding attachment 10, and a main body 11 is attached to the spindle 4 of the machine tool 2. In the main body 11, the processing shaft 14 and the welding tool 20 are rotated by a rotation drive unit 15, and the rotating welding tool 20 is brought into contact with the workpiece 9, thereby performing friction stir welding of the workpiece 9. In this case, the rotation drive unit 15 can be an air motor or the like that is driven by center-through air from the spindle 4, and is not dependent on the rotation of the spindle 4.
On the other hand, by rotating the spindle 4, the main body 11 rotates together with the spindle 4, and the orientation of the machining axis 14 and the joining tool 20 in the main body 11 (the orientation in which the rotation axis Cc is inclined) can be changed to any orientation.
This makes it possible to easily change the inclination direction (front side Dc) of the welding tool 20 by rotating the main shaft 4 .

In this embodiment, an air motor is used as the rotary drive unit 15, and center through air from the main shaft 4 is used, so that an external power supply is not required and a power source can be easily secured.
In this embodiment, since the processing axis 14 is coaxial with the axis R of the spindle 4, only the position of the welding tool 20 in the direction of axis R is different from the case where the welding tool 20 is directly attached to the spindle 4, and the position relative to the surface of the workpiece 9 is the same. Therefore, based on the control program for the case where the welding tool 20 is directly attached to the spindle 4, it can be diverted with only minimal changes such as numerical correction in the direction of axis R.

Next, a second embodiment of the present invention will be described with reference to FIGS.
The basic configuration of this embodiment is similar to that of the first embodiment described above, and therefore a duplicated description will be omitted.
In the first embodiment described above, the machining shaft 14 and the joining tool 20 are arranged coaxially with the axis R of the spindle 4, and the orientation of the front side Dc of the machining shaft 14 and the joining tool 20 in the main body 11 is changed by rotation of the spindle 4.
In contrast, in this embodiment, the processing shaft 14 and the welding tool 20 are arranged in a direction intersecting the axis R of the main shaft 4, and the rotation of the main shaft 4 changes the orientation of the rotation axis Cc of the processing shaft 14 and the welding tool 20.

In FIG. 4, a friction stir welding attachment 10A has a main body 11A that is attached to a spindle 4 of a machine tool 2.
The main body 11A has a tapered shank 111 and a center through hole 112 similar to those in the first embodiment at the end on the spindle 4 side. On the other hand, an expansion section 113 is formed at the end opposite the spindle 4, and an air passage 114 communicating with the center through hole 112 is formed in the expansion section 113.

The extension section 113 is provided with a processing shaft 14 to the tip of which a joining tool 20 can be attached, and a rotation drive section 15 that drives the processing shaft 14 to rotate.
The rotation axis Cc of the processing shaft 14 and the rotation drive unit 15 is disposed in a direction intersecting with the axis R of the main spindle 4 .
The rotation drive unit 15 is configured with an air motor as in the first embodiment, and is capable of rotating the processing shaft 14 using the center through air supplied from the main shaft 4 via an air passage 114 and a center through hole 112 as a power source.

The tip of the processing shaft 14 is exposed from the surface of the extension portion 113, and a joining tool 20 is attached to the tip.
The machining axis 14 is positioned in a direction intersecting the rotation axis Cc, i.e., the axis R of the spindle 4, such that when the joining tool 20 is attached to the machining axis 14, the machining site (tip position) of the joining tool 20 is on the axis R of the spindle 4.

Therefore, in the friction stir welding attachment 10A of the present embodiment, by supplying center-through air from the spindle 4 to the rotation drive unit 15 through the center through hole 112 and the air passage 114, the processing shaft 14 and the welding tool 20 are rotationally driven (rotational operation Rc) by the rotation drive unit 15, and friction stir welding can be performed by the welding tool 20 even on a cylindrical workpiece 9A as shown in FIG. 5.
At this time, the welding tool 20 is oriented in a horizontal direction Di in which the rotation axis Cc intersects with the axis R, and friction stir welding can be performed on the vertical side surface of the workpiece 9A. The friction stir welding is performed by rotating the welding tool 20 and moving its tip horizontally in a direction intersecting with the direction of FIG. 4 (to the front side Dc).
On the other hand, by rotationally driving the main body 11A by the main shaft 4 (rotational motion Rs), the direction Di of the welding tool 20 can be changed.

In FIG. 5, when friction stir welding is performed on a cylindrical workpiece 9A from a start position 94 to an end position 95 on a peripheral surface 93 thereof, the direction Di and the front side Dc of the friction stir welding attachment 10A are changed as the welding operation progresses.
First, the welding tool 20 is moved in the direction Di while rotating (rotational motion Rc) and is pushed into the workpiece 9A at a start position 94 to start the welding operation. Then, the welding tool 20 is moved to the front side Dc and friction stir welding is performed up to an end position 95.
At this time, the main body 11A is rotationally driven (rotational motion Rs) by the spindle 4 so that the direction Di is perpendicular to the surface of the peripheral surface 93. As a result, the front side Dc of the friction stir welding attachment 10A is also changed in direction so as to be aligned with the peripheral surface 93.
As a result, the welding tool 20 is always oriented perpendicular to the peripheral surface 93, and appropriate friction stir welding can be performed even on the peripheral surface 93 of the cylindrical workpiece 9A.

Next, a third embodiment of the present invention will be described with reference to FIG.
The friction stir welding attachment 10B of this embodiment has the same basic configuration as that of the first embodiment described above, and therefore a duplicated description will be omitted.
In the first embodiment described above, the rotation drive unit 15 rotates the processing shaft 14 using the center through air supplied from the main shaft 4 via the center through hole 112 as a power source.
In contrast to this, in this embodiment, air is used that is supplied from the spindle head 5 through a fixed part 16 rotatably attached to the outside of the main body 11 .

The fixed portion 16 is attached to the main body 11 via a bearing (not shown), and the main body 11 and the main shaft 4 are capable of relative rotation around the axis R.
A portion of the fixing portion 16 extends radially outward, and a sub-shank 161 is formed at the tip of the portion.
When the tapered shank 111 is attached to the spindle 4 , the sub shank 161 is fitted into a receiving portion of the spindle head 5 , and an air passage 162 is formed through the sub shank 161 from the main body 11 to the spindle head 5 .
Between the main body 11 and the fixed portion 16, a coupling (not shown) is formed that allows air transfer even in a rotating state.

With this friction stir welding attachment 10B as well, it is possible to obtain the same effects as those of the first embodiment described above.
Furthermore, air can be supplied to the rotary drive unit 15 from the spindle head 5 using the sub-shank 161 of the fixed unit 16, and this can be easily implemented even in a machine tool 2 having a spindle 4 that is not center-through.

Next, a fourth embodiment of the present invention will be described with reference to FIG.
The friction stir welding attachment 10C of this embodiment has the same basic configuration as that of the second embodiment described above, and therefore a duplicated description will be omitted.
In the second embodiment described above, the rotation drive unit 15 rotates the processing shaft 14 using the center through air supplied from the spindle 4 via the center through hole 112 and the air passage 114 as a power source.
In contrast to this, in this embodiment, air is used that is supplied from the spindle head 5 through a fixed part 16 rotatably attached to the outside of the main body 11 .

The fixing portion 16 is similar to that of the third embodiment described above, and a duplicated description will be omitted.
With this friction stir welding attachment 10C as well, the same effects as those of the second embodiment described above can be obtained.
Furthermore, air can be supplied to the rotary drive unit 15 from the spindle head 5 using the sub-shank 161 of the fixed unit 16, and this can be easily implemented even in a machine tool 2 having a spindle 4 that is not center-through.

The present invention is not limited to the above-described embodiment, and modifications within the scope of the present invention are included in the present invention.
In each of the above embodiments, the rotary drive unit 15 is an air motor. However, the rotary drive unit 15 may be an electric motor that receives power from the spindle head 5 via an external cable.
In the first and third embodiments, the rotation axis Cc of the rotary drive unit 15 and the machining shaft 14 is inclined at an angle At (0 to 5 degrees) with respect to the axis R of the main spindle 4, but this angle can be selected appropriately. In addition, the rotary drive unit 15 and the machining shaft 14 may be connected by a universal joint or the like, and the rotation center of the rotary drive unit 15 may be the axis R while the rotation axis Cc of the machining shaft 14 is inclined.
In each of the above-described embodiments, the rotation axis Cc of the machining shaft 14 and the joining tool 20 is set to a direction along the axis R of the spindle 4 (see FIGS. 2 and 6) or a direction perpendicular to the axis R (see FIGS. 4 and 7). However, the rotation axis Cc may be set to any angle in between, such as 45 degrees, and a rotation mechanism may be added to the extension portion 113 to make the angle selectable.
In the second and fourth embodiments, the position of the processing axis 14 is set so that the tip of the welding tool 20 is aligned with the axis R of the spindle 4 .

The present invention can be used in a friction stir welding attachment, a friction stir welding head, a friction stir welding device, and a friction stir welding method.

1...Friction stir welding device, 2...Machine tool, 3...Table, 4...Spindle, 5...Spindle head, 6...Moving mechanism, 61...Guide bar, 62...Slider, 7...Bed, 8...Cover, 9, 9A...Workpiece, 91...Welding line, 92...Welding line, 93...Circumference, 94...Start position, 95...End position, 10, 10A...Friction stir welding attachment, 11, 11A...Main body, 111...Tapered shank, 112...Center through hole, 113...extension part, 114...air passage, 14...machining shaft, 15...rotation drive part, 16...fixed part, 161...sub shank, 162...air passage, 19...friction stir welding head, 20...welding tool, Ar...tilt angle, At...orientation angle, Cc...rotation axis, D1...welding direction, D2...welding direction, Dc...front side of attachment, Di...orientation, R...axis of spindle, Rc...rotational movement of welding tool, Rs...rotational movement of spindle.

Claims (7)

a main body attached to a spindle rotatably supported on a spindle head of a machine tool;
a processing shaft that is rotatably supported by the main body and to which a joining tool can be attached;
A rotation drive unit that rotates the processing shaft;
a fixing part that is rotatably attached to the outside of the main body and is coaxial with the spindle and is connectable to the spindle head;
an air passage formed in the fixed portion for supplying air supplied from the spindle head to the rotary drive portion,
Friction stir welding attachment, characterized in that the rotation drive unit is an air motor that is rotated by air supplied from the air passage . The friction stir welding attachment according to claim 1 ,
A friction stir welding attachment, characterized in that the processing shaft is arranged coaxially on the axis of the main shaft. The friction stir welding attachment according to claim 1 ,
A friction stir welding attachment, characterized in that the processing shaft is arranged in a direction intersecting with an axis of the main shaft. The friction stir welding attachment according to claim 3 ,
A friction stir welding attachment, characterized in that the processing shaft is positioned in a direction intersecting the axis of the main shaft so that when the welding tool is attached to the processing shaft, the processing portion of the welding tool is on the axis of the main shaft. A friction stir welding attachment according to any one of claims 1 to 4 ,
and the welding tool attached to the friction stir welding attachment. A friction stir welding attachment according to any one of claims 1 to 4 ,
The welding tool attached to the friction stir welding attachment;
and a machine tool to which the friction stir welding attachment is attached. Using the friction stir welding apparatus according to claim 6 ,
The rotation drive unit rotates the welding tool to perform friction stir welding on the workpiece,
A friction stir welding method, comprising changing an orientation of the welding tool by rotating the spindle.

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