Title of Invention
FRICTION-STIR WELDING TOOL, FRICTION STIR WELDING DEVICE,
AND METHOD FOR MANUFACTURING WELDING MATERIAL
Technical Field
[0001]
The present invention relates to a friction-stir
welding tool used when plate materials are abutted to each
other to be welded, a friction stir welding device, and a
method for manufacturing welding material using the
friction-stir welding tool.
Background Art
[0002]
As a method for welding a work-piece configured of
two members, friction stir welding is known. Friction
stir welding is a welding method in which a tool is
rotated in a state where an abutment portion of the workpiece
is pressurized by a shoulder surface of the tool and
in which the work-piece is welded using friction heat
generated on the surface of the work-piece.
[0003]
Meanwhile, in the friction stir welding, a tool
referred to as a bobbin tool may be used. In the bobbin
tool, a front side shoulder having one shoulder surface is
disposed on a front surface side of the work-piece, a rear
side shoulder having the other shoulder surface opposing
the one shoulder surface is disposed on a rear surface
side of the work-piece, and the two shoulders are
connected to each other by a probe penetrating the workpiece.
In this way, the front surface and the rear
surface of the work-piece are interposed between the
shoulder surfaces of the two shoulders and pressurized,
frictional heat is generated, the work-piece is stirred by
the probe, and thus, the friction stir welding of the
work-piece is performed.
[0004]
Here, in the work-piece, non-uniformity of plate
thickness due to distortion or manufacturing errors may
Occur. Particularly, in an outer plate or the like which
is used in a vehicle of a track transportation system
referred to as an automated people mover (APM) or a train,
a long hollow panel is used. Moreover, in the long member,
significant change in the thickness in the length
direction occurs. In addition, for example, when the
plate thickness in the weld direction is thin, welding
pressure from the shoulder surfaces to the work-piece
decreases, and there is a concern that sufficient welding
quality may not be obtained.
[0005]
PTL 1 discloses a friction stir welding mechanism
which controls a gap between shoulder surfaces by allowing
a lower shoulder (rear side shoulder) to move close to and
move away from an upper shoulder (front side shoulder)
using hydraulic pressure according to a change in a plate
thickness of a work-piece, and can adjust welding pressure
with respect to the work-piece.
Citation List
Patent Literature
[0006]
[PTL 1] Japanese Unexamined Patent Application
Publication No. 2004-243375
Summary of Invention
Technical Problem
[0007]
However, although it is not specifically described
in PTL 1, in the mechanism, a control device which
controls the hydraulic pressure is separately required.
Accordingly, the entire friction stir welding device is
complicated, and thus, cost increases.
[0008]
The present invention provides a friction-stir
welding tool, a friction stir welding device, and a method
for manufacturing welding material capable of accurately
performing friction stir welding while decreasing cost
using a simple. structure.
Solution to Problem
[0009]
According to a first aspect of the present invention,
there is provided a friction-stir welding tool, including:
an axially extending front side shoulder; a rear side
shoulder which is provided to axially oppose the front
side shoulder, and comes into contact with plate materials
to interpose an abutment portion of the plate materials
between the front side shoulder and the rear side
shoulder; and a probe which is disposed to penetrate the
plate materials between the front side shoulder and the
rear side shoulder, extends in the axis direction, and
connects the front side shoulder and the rear side
shoulder to each other. The probe includes a first screw
part provided on at least one axial end section, and at
least one of the front side shoulder and the rear side
shoulder includes a second screw part, the second screw
part is in threaded engagement with the first screw part,
the state of the threaded engagement is changed so that
the front side shoulder and the rear side shoulder axially
move close to each other as the front side shoulder and
the rear side shoulder rotate relative to each other, and
the second screw part links at least one of the front side
e-
3
shoulder and the rear side shoulder with the probe due to
the threaded engagement between the first screw part and
the second screw part.
[0010]
According to this friction-stir welding tool, the
front side shoulder and the rear side shoulder are rotated
in the state where the plate materials are interposed
between the front side shoulder and the rear side shoulder,
and the plate materials are welded by the friction stir
welding. Here, since the rear side shoulder comes into
contact with the plate materials, a friction force is
applied to a portion between the rear side shoulder and
the plate materials during the welding. If the friction
force from the plate materials is applied to the rear side
shoulder, the rotation of the rear side shoulder is
suppressed by the friction force. Meanwhile, since the
front side shoulder rotates without interference due to
rotation, a force by which the front side shoulder and the
rear side shoulder are to be rotated relative to each
other is generated between the front side shoulder and the
rear side shoulder. In addition, in the present invention,
the state of the threaded engagement between the first
screw part and the second screw part is changed such that
the front side shoulder and the rear side shoulder move
closer to each other according to the relative rotation
thereof. Here, when the front side shoulder and the rear
side shoulder move to closer to each other and a gap
between the front side shoulder and the second-side
shoulder reaches a predetermined gap distance, a screwing
force (a force due to a friction force between the first
screw part and the second screw part) when the second
screw part is screwed into the first screw part and a
reaction force of a welding pressure of the rear side
shoulder receiving from the plate materials are balanced
with each other, and thus, the state of the threaded
engagement between the first screw part and the second
screw part is not changed. For example, when the plate
thickness of the plate material is thin during the welding,
the welding pressure applied from the rear side shoulder
to the plate material decreases. However, in this case,
the state of the threaded engagement between the first
screw part and the second screw part is changed so that
the front side shoulder and the rear side shoulder move
closer to each other, and the plate materials are
interposed between the front side shoulder and the rear
side shoulder in the state where the screwing force and
the reaction force are balanced with each other.
Therefore, it is possible to weld the plate materials.
Accordingly, the lead angles of the first screw part and
the second screw part or the like are set so that the
state where the forces are balanced with each other and
becomes the state where the welding pressure of the rear
side shoulder with respect to the plate material is
suitable during the welding. Therefore, it is possible to
perform the friction stir welding at a suitable welding
pressure in a state where the gap between the front side
shoulder and the rear side shoulder is automatically
maintained so as to be constant without providing a
complicated control device or the like.
[0011]
In addition, according to a friction-stir welding
tool of a second aspect of the present invention, in the
first aspect, the front side shoulder may include the
second screw part, and the rear side shoulder and the
probe may be integrated with each other.
[0012]
In this way, the integrated rear side shoulder and
the probe are screwed into the front side shoulder so that
the first screw part and the second screw part are in
threaded engagement with each other. Accordingly, it is
possible to perform the friction stir welding in the state
where the plate materials are easily interposed
therebetween.
[0013]
Moreover, according to a friction-stir welding tool
of a third aspect of the present invention, in the second
aspect, the second screw part may be a female screw
provided in a hole part which is formed toward a direction
moving away from the rear side shoulder axially from an
end surface of the front side shoulder, and a diameterexpanding
hole part having a larger inner diameter than an
outer diameter of the probe may be formed between the
second screw part and the end surface in the hole part.
[0014]
In this way, the second screw part is provided, and
the diameter-expanding hole part is formed. Accordingly,
even when the plate thickness of the plate material is
smaller than an axial size of a portion of the probe in
which the first screw is not provided, that is, a portion
of the probe which stirs the plate material, it is
possible to insert the stirring portion into the diameterexpanding
hole part. Therefore, it is possible to
decrease the gap between the front side shoulder and the
rear side shoulder in accordance with the plate thickness
of the plate material, it is possible to flexibly cope
with the change in the plate thickness of the plate
material, and it is possible to maintain a suitable
welding pressure applied from the rear side shoulder to
the plate material.
[0015]
In addition, according to a friction-stir welding
tool of a fourth aspect of the present invention, in the
first aspect, the rear side shoulder may include the
second screw part, and the front side shoulder and the
probe may be integrated with each other.
[0016]
In this way, the integrated front side shoulder and
probe are screwed into the rear side shoulder so that the
first screw part and the second screw part are in threaded
engagement with each other. Accordingly, it is possible
to perform the friction stir welding in the state where
the plate materials are easily interposed therebetween.
[0017]
Moreover, according to a friction-stir welding tool
of a fifth aspect of the present invention, in the first
aspect, the front side shoulder and the rear side shoulder
may include the second screw part, and the probe may
include the first screw part on both axial end sections.
[0018]
The probe, the front side shoulder, and the rear
side shoulder are separate members, and thus, it is
possible to easily manufacture each member.
[0019]
In addition, according a sixth aspect of the present
invention, there is provided a friction stir welding
10
device including a friction-stir welding tool according to
any one of the first to fifth aspects; a main body part
which is provided on a front surface of the plate
material; and a tool holding
main body part, holds the
friction-stir welding tool,
part which is attached to the
front side shoulder in the
and rotates the front side
shoulder with respect to the main body part with the axis
as the center of rotation.
[0020]
According to the friction stir welding device, when
the plate thickness of the plate material is changed and
the welding pressure applied from the rear side shoulder
to the plate material decreases, the front side shoulder
and the rear side shoulder rotate relative to each other
using the friction-stir welding tool and the front side
shoulder and the rear side shoulder move closer to each
other. Thereafter, the screwing force generated when the
second screw part is screwed into the first screw part and
the reaction force of the rear side shoulder receiving
from the plate materials are balanced with each other, and
the state of the threaded engagement is not changed.
Accordingly, it is possible to perform the friction stir
welding at a suitable welding pressure in a state where
the gap between the front side shoulder and the rear side
shoulder is automatically maintained so as to be constant
- I twithout
providing a complicated control device or the like.
[0021]
In addition, according to a seventh aspect of the
present invention, there is provided a method for
manufacturing welding material by manufacturing a welding
material using a friction-stir welding tool including an
axially extending front side shoulder, a rear side
shoulder which is provided to axially oppose the front
side shoulder, and comes into contact with plate materials
to interpose an abutment portion of the plate materials
between the front side shoulder and the rear side shoulder,
and a probe which is disposed to penetrate the plate
materials between the front side shoulder and the rear
side shoulder, extends in the axis direction, and connects
the front side shoulder and the rear side shoulder to each
other, in which the probe includes a first screw part
provided on at least one axial end section, at least one
of the front side shoulder and the rear side shoulder
includes a second screw part, and the second screw part is
in threaded engagement with the first screw part to link
at least one of the front side shoulder and the rear side
shoulder with the probe, including: a preparation step of
disposing the front side shoulder and the rear side
shoulder to axially interpose the abutment portion of the
plate materials therebetween, and allowing the probe to
penetrate the plate materials; a connection step of
allowing the second screw part to be in threaded
engagement with the first screw part, and connecting the
front side shoulder and the rear side shoulder to each
other by using the probe; an adjustment step of adjusting
a fastening force between the first screw part and the
second screw part; and a welding step of rotating the
front side shoulder and the rear side shoulder about the
axis and performing friction stir welding to weld the
plate materials, in a state where the first screw part and
the second screw part are fastened to each other at a
predetermined fastening force, in the adjustment step.
The welding step includes an automatic adjustment step of
automatically changing the state of the threaded
engagement between the first screw part and the second
screw part so that the front side shoulder and the rear
side shoulder move closer to each other as the front side
shoulder and the rear side shoulder rotate relative to
each other.
[0022]
According the method for manufacturing welding
material, when the plate thickness of the plate material
is changed and the welding pressure applied from the rear
side shoulder to the plate material decreases while the
welding step is performed, the front side shoulder and the
rear side shoulder are rotated relative to each other and
the front side shoulder and the rear side shoulder move
closer to each other. Thereafter, the screwing force
generated when the second screw part is screwed into the
first screw part and the reaction force of the rear side
shoulder receiving from the plate materials are balanced
with each other, and the state of the threaded engagement
is not changed. Accordingly, it is possible to perform
the friction stir welding at a suitable welding pressure
in a state where the gap between the front side shoulder
and the rear side shoulder is automatically maintained so
as to be constant without providing a complicated control
device or the like.
[0023]
Moreover, according to a method for manufacturing
welding material of an eighth aspect of the present
invention, in the seventh aspect, a reverse rotation step
may be provided, in which the front side shoulder and the
rear side shoulder are rotated about the axis in a
direction opposite to the direction of the welding step at
a terminal of the welding portion after the plate
materials are welded in the welding step.
[0024]
According to the reverse rotation step, by reversely
rotating the front side shoulder and the rear side
—14—
shoulder after the plate materials are welded, the
rotation of the rear side shoulder is prevented by the
friction force applied to the rear side shoulder from the
plate material. Meanwhile, since the front side shoulder
is to be reversely rotated without interference from
rotation, the force by which the front side shoulder and
the rear side shoulder are to be rotated relative to each
other is generated between the front side shoulder and the
rear side shoulder. In addition, by rotating the front
side shoulder and the rear side shoulder relative to each
other, it is possible to change the state of the threaded
engagement between the first screw part and the second
screw part so that the front side shoulder and the rear
side shoulder move away from each other. Accordingly,
even when the front side shoulder and the rear side
shoulder adhere to each other during the welding, it is
possible to easily remove the rear side shoulder from the
front side shoulder. In addition, since it is possible to
widen the gap between the front side shoulder and the rear
side shoulder, it is possible to automatically prepare the
subsequent welding work.
Advantageous Effects of Invention
[0025]
According to a friction-stir welding tool, a
friction stir welding device, and a method for
manufacturing welding material of the present invention,
it is possible to accurately perform friction stir welding
while decreasing cost using a simple structure.
Brief Description of Drawings
[0026]
Fig. 1 is a front view showing a friction stir
welding device according to a first embodiment of the
present invention.
Fig. 2 is a front view showing a state where a tool
used in the friction stir welding device according to the
first embodiment of the present invention is disassembled.
Fig. 3 is a front view showing a state where the
tool used in the friction stir welding device according to
the first embodiment of the present invention is enlarged,
and shows a state during a welding step.
Fig. 4 is a flow chart showing a procedure of a
method for manufacturing welding material used in the
friction stir welding device according to the first
embodiment of the present invention.
Fig. 5 is a view showing a relationship between a
change of a plate thickness of a work-piece along a
welding direction and a change of a gap between an upper
shoulder and a lower shoulder in the friction stir welding
device according to the first embodiment of the present
invention.
- itFig.
6 is a view showing a relationship between a
change of a plate thickness of a work-piece along a
welding direction and a change of a gap between an upper
shoulder and a lower shoulder in a friction stir welding
device of a related art.
Fig. 7 is a front view showing a state where a tool
used in a friction stir welding device according to a
second embodiment of the present invention is disassembled.
Fig. 8 is a front view showing a state where the
tool used in the friction stir welding device according to
the second embodiment of the present invention is enlarged,
and shows a state during a welding step.
Fig. 9 is a front view showing a state where a tool
used in a friction stir welding device according to a
third embodiment of the present invention is disassembled.
Description of Embodiments
[0027]
[First Embodiment]
Hereinafter, a friction stir welding device 100 of a
welding material W according to a first embodiment of the
present invention will be described.
The friction stir welding device 100 is a device for
welding an abutment portion Wla of the plate materials W1
using friction stir welding and for manufacturing a
welding material W.
As shown in Fig. 1, the friction stir welding device
100 includes a bed 101 which is a base, a surface plate
102 which is disposed on the bed 101, a gate-shaped device
main body 103 (main body part) which is provided on the
bed 101 to surround the periphery of the surface plate 102,
a machine head 104 (tool holding part) which is provided
on the device main body 103, and a friction-stir welding
tool 1 (hereinafter, simply referred to as a tool 1) which
is fixed to a lower end portion of the machining head 104.
[0028]
The bed 101 is formed in a plate shape and receives
a reaction force during the friction stir welding.
[0029]
In the surface plate 102, an upper surface of the
surface plate 102 becomes a reference surface (XY plane)
in a Z axis direction orthogonal to the bed 101, and plate
materials W1 which are welded members are fixed to an
upper surface 5a in a state where the plate materials W1
are abutted to each other.
[0030]
The device main body 103 is formed in a gate shape,
which rises upward from both sides in a right-left
direction (Y axis direction) of the surface plate 102 in
the bed 101, and thereafter, extends in a Y axis direction
above the surface plate 102. Moreover, the device main
-itbody
103 is able to move in an X axis direction orthogonal
to a plane parallel to the surface plate 102 in the Y axis
direction.
[0031]
The machining head 104 is attached to the device
main body 103 above the surface plate 102, extends
downward in the Z axis direction, and is provided so as to
be able to move in the Y axis direction with respect to
the device main body 103. In addition, the machining head
104 includes a rotary mechanism 105 which is attached to
the lower portion in the Z axis direction, and is able to
rotate about the Z axis.
In the present embodiment, when friction stir
welding is performed, the rotary mechanism 105 rotates in
a clockwise direction when viewed from above in the Z axis
direction (refer to arrows shown in the upper portions of
Figs. 1 and 3).
[0032]
As shown in Fig. 2, the tool 1 includes an upper
shoulder 6 (front side shoulder) which is disposed at the
upper portion in the Z axis direction with respect to the
abutment portion Wla of two plate materials W1 abutted to
each other in the Y axis direction, a lower shoulder 5
(rear side shoulder) which is disposed at the lower
portion, and a probe 7 which connects the upper shoulder 6
and the lower shoulder 5,
[0033]
The lower shoulder 5 is formed in a columnar shape
with an axis P parallel to the Z axis direction as the
center, and the upper surface 5a comes into contact with
the plate material W1 when friction stir welding is
performed.
[0034]
The probe 7 is formed in a columnar shape which is
formed so as to be coaxial with the lower shoulder 5, is
linked with the lower shoulder 5, and extends upward in
the Z axis direction along the axis P from the upper
surface 5a of the lower shoulder 5. Moreover, the probe 7
is a rod-shaped member having a smaller diameter than an
outer diameter of the lower shoulder 5, and is disposed so
as to penetrate the abutment portion Wla in the Z axis
direction. Moreover, the probe 7 includes a male screw
part 8 (first screw part) which is formed on the upper end
section in the Z axis direction. In the present
embodiment, the male screw part 8 is a right-hand screw.

Amended Claim (Article 19)
[Received by International Bureau on April 4, 2014]
[Claim 1] (Amended)
A friction-stir welding tool, comprising:
an axially extending front side shoulder;
a rear side shoulder which is provided to axially
oppose the front side shoulder, and comes into contact
with plate materials to interpose an abutment portion of
the plate materials between the front side shoulder and
the rear side shoulder; and
a probe which is disposed to penetrate the plate
materials between the front side shoulder and the rear
side shoulder, extends in the axis direction, and connects
the front side shoulder and the rear side shoulder to each
other,
wherein the probe includes a first screw part
provided on at least one axial end section,
wherein at least one of the front side shoulder and
the rear side shoulder includes a second screw part, the
second screw part is in threaded engagement with the first
screw part, the state of the threaded engagement is
changed so that the front side shoulder and the rear side
shoulder axially move closer to each other as the front
side shoulder and the rear side shoulder rotate relative
to each other, and the second screw part links at least
one of the front side shoulder and the rear side shoulder
with the probe due to the threaded engagement between the
first screw part and the second screw part, and
wherein lead angles of the first screw part and the
second screw part are set such that a state where a
screwing force when the state of the threaded engagement
is changed and the second screw part is screwed into the
first screw part and a reaction force of a welding
pressure of the rear side shoulder receiving from the
plate material are balanced with each other and become a
state where the welding pressure of the rear side shoulder
with respect to the plate material is suitable during the
welding.
[Claim 2]
The friction-stir welding tool according to claim 1,
wherein the front side shoulder includes the second
screw part, and
wherein the rear side shoulder and the probe are
integrated with each other.
[Claim 3]
The friction-stir welding tool according to claim 2,
wherein the second screw part is a female screw
provided in a hole portion which is formed toward a
direction moving away from the rear side shoulder axially
ttO
from an end surface of the front side shoulder, and
wherein a diameter-expanding hole part having a
larger inner diameter than an outer diameter of the probe
is formed between the second screw part and the end
surface in the hole part.
[Claim 4]
The friction-stir welding tool according to claim 1,
wherein the rear side shoulder includes the second
screw part, and
wherein the front side shoulder and the probe are
integrated with each other.
[Claim 5]
The friction-stir welding tool according to claim 1,
wherein the front side shoulder and the rear side
shoulder includes the second screw part, and
wherein the probe includes the first screw part on
both axial end sections.
[Claim 6]
A friction stir welding device, comprising:
a friction-stir welding tool according to any one of
claims 1 to 5;
a main body part which is provided on a front
surface of the plate material; and
a tool holding part which is attached to the main
body part, holds the front side shoulder in the friction-
4
stir welding tool, and rotates the front side shoulder
with respect to the main body part with the axis as the
center of rotation.
[Claim 7]
A method for manufacturing welding material by
manufacturing a welding material using a friction-stir
welding tool including an axially extending front side
shoulder, a rear side shoulder which is provided to
axially oppose the front side shoulder, and comes into
contact with plate materials to interpose an abutment
portion of the plate materials between the front side
shoulder and the rear side shoulder, and a probe which is
disposed to penetrate the plate materials between the
front side shoulder and the rear side shoulder, extends in
the axis direction, and connects the front side shoulder
and the rear side shoulder to each other, in which the
probe includes a first screw part provided on at least one
axial end section, at least one of the front side shoulder
and the rear side shoulder includes a second screw part,
and the second screw part is in threaded engagement with
the first screw part to link at least one of the front
side shoulder and the rear side shoulder with the probe,
comprising:
a preparation step of disposing the front side
shoulder and the rear side shoulder to axially interpose
the abutment portion of the plate materials therebetween,
and allowing the probe to penetrate the plate materials;
a connection step of allowing the second screw part
to be in threaded engagement with the first screw part,
and connecting the front side shoulder and the rear side
shoulder to each other by using the probe;
an adjustment step of adjusting a fastening force
between the first screw part and the second screw part;
and
a welding step of rotating the front side shoulder
and the rear side shoulder about the axis and performing
friction stir welding to weld the plate materials, in a
state where the first screw part and the second screw part
are fastened to each other at a predetermined fastening
force, in the adjustment step.
wherein the welding step includes an automatic
adjustment step of automatically changing the state of the
threaded engagement between the first screw part and the
second screw part so that the front side shoulder and the
rear side shoulder move closer to each other as the front
side shoulder and the rear side shoulder rotate relative
to each other.
[Claim 8]
The method for manufacturing welding material
according to claim 7, further comprising:
t(3
a reverse rotation step of rotating the front side
shoulder and the rear side shoulder about the axis in a
direction opposite to the direction of the welding step at
a terminal of the welding portion after the plate
materials are welded in the welding step.