U.S. patent application number 12/805385 was filed with the patent office on 2010-11-25 for method of joining two members by friction stir welding.
Invention is credited to Kinya Aota, Yasuo Ishimaru, Tsuyoshi Takenaka.
Application Number | 20100297469 12/805385 |
Document ID | / |
Family ID | 13201704 |
Filed Date | 2010-11-25 |
United States Patent
Application |
20100297469 |
Kind Code |
A1 |
Aota; Kinya ; et
al. |
November 25, 2010 |
Method of joining two members by friction stir welding
Abstract
This invention provides a configuration of a joint that allows a
satisfactory welded joint to be formed with reduced deformation of
the joint region when two-face structures (panels) are
friction-welded end to end. The panels 31, 32 each have two
substantially parallel plates 33, 34 and a third member 35
connecting the two plates 33, 34. The end portions of the plates
33, 34 of one panel 32 are friction-welded to the end portions of
the plates 33, 34 of the other panel 32. At least one of the panels
has a plate 36 at its end for connecting the plates 33 and 34 and
has a rigidity to support a pressing force produced during the
friction welding.
Inventors: |
Aota; Kinya; (Kudamatsu-Shi,
JP) ; Takenaka; Tsuyoshi; (Yamaguchi-Ken, JP)
; Ishimaru; Yasuo; (Kudamatsu-Shi, JP) |
Correspondence
Address: |
ANTONELLI, TERRY, STOUT & KRAUS, LLP
1300 NORTH SEVENTEENTH STREET, SUITE 1800
ARLINGTON
VA
22209-3873
US
|
Family ID: |
13201704 |
Appl. No.: |
12/805385 |
Filed: |
July 28, 2010 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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11453147 |
Jun 15, 2006 |
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12805385 |
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10600573 |
Jun 23, 2003 |
7073701 |
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11453147 |
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08820231 |
Mar 18, 1997 |
6581819 |
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10600573 |
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Current U.S.
Class: |
428/615 |
Current CPC
Class: |
Y10T 428/12375 20150115;
B23K 20/122 20130101; B23K 2101/045 20180801; B61D 17/043 20130101;
Y10T 428/192 20150115; Y10T 428/1234 20150115; B23K 20/123
20130101; B23K 33/004 20130101; Y10T 428/24777 20150115; B23K
20/126 20130101; E04C 2/36 20130101; E04C 2/543 20130101; Y10T
403/478 20150115; E04C 2/08 20130101; Y10T 428/12 20150115; B23K
33/00 20130101; Y10T 428/12382 20150115; Y10T 428/12493
20150115 |
Class at
Publication: |
428/615 |
International
Class: |
B32B 15/01 20060101
B32B015/01 |
Foreign Application Data
Date |
Code |
Application Number |
Mar 19, 1996 |
JP |
8-62491 |
Claims
1. A structure of a panel friction stir welded to a plate member,
wherein: said panel comprises a first plate, a second plate
substantially parallel to said first plate, plural ribs for
connecting said first plate and said second plate, and a vertical
plate for connecting an end portion in a width direction of said
first plate and said second plate and being substantially
perpendicular to said first plate and said second plate; said first
plate of said panel and said plate member are friction stir welded;
and a friction stir welded bead formed between said first plate of
said panel and said plate member lies at least in a range of a
plate thickness of said vertical plate.
2. A structure according to claim 1, wherein a center in a width
direction of said friction stir welded bead lies in a range of said
plate thickness of said vertical plate of said panel.
3. A structure of a first panel friction stir welded to a second
panel, wherein: said first panel comprises a first plate, a second
plate substantially parallel to said first plate, plural ribs for
connecting said first plate and said second plate, and a vertical
plate for connecting an end portion in a width direction of said
first plate and said second plate and being substantially
perpendicular to said first plate and said second plate; said
second panel comprises a first plate, a second plate substantially
parallel to said first panel, and plural ribs for connecting said
first plate and said second plate; said first plate of said first
panel and said first plate of said second panel are friction stir
welded; and a friction stir welded bead formed between said first
plate of said first panel and said first plate of said second panel
lies at least in a range of a plate thickness of said vertical
plate of said first panel.
4. A structure according to claim 3, wherein a center in a width
direction of said friction stir welded bead lies in a range of said
plate thickness of said vertical plate of said first panel.
5. A structure of a first panel friction stir welded to a second
panel, wherein: said first panel comprises a first plate, a second
plate substantially parallel to said first plate, plural ribs for
connecting said first plate and said second plate, and a vertical
plate for connecting an end portion in a width direction of said
first plate and said second plate and being substantially
perpendicular to said first plate and said second plate; said
second panel comprises a first plate, a second plate substantially
parallel to said first plate of said second panel, and plural ribs
for connecting said first plate of the second panel and said second
plate of the second panel; said first plate of said first panel and
said first plate of said second panel are friction stir welded;
said second plate of said first panel and said second plate of said
second panel are friction stir welded; a friction stir welded bead
formed between said first plate of said first panel and said first
plate of said second panel lies at least in a range of a plate
thickness of said vertical plate of said first panel; and a
friction stir welded bead formed between said second plate of said
first panel and said second plate of said second panel lies at
least in said range of said plate thickness of said vertical plate
of said first panel.
6. A structure according to claim 5, wherein a respective center in
a width direction of both of the friction stir welded beads lies in
a range of said plate thickness of said vertical plate of said
first panel.
Description
[0001] This application is a Continuation application of
application Ser. No. 11/453,147, filed Jun. 15, 2006, which is a
Divisional application of application Ser. No. 10/600,573, filed
Jun. 23, 2003, which is a Divisional application of application
Ser. No. 08/820,231, filed Mar. 18, 1997, the contents of which are
incorporated herein by reference in their entirety.
BACKGROUND OF THE INVENTION
[0002] The present invention relates to a friction stir welding
method that is applicable to panel welding used, for example, in
aluminum alloy railway cars and buildings.
[0003] A two-face structure (panel) for railway cars using hollow
members is disclosed in Japanese Patent Laid-Open No. 246863/1990,
and another using laminated panels, such as honeycomb panels, is
disclosed in Japanese Patent Laid-Open No. 106661/1994.
[0004] The process of friction stir welding is performed by
rotating a round rod inserted in a joint region to heat and
plasticize the joint region thus forming a weld. This type of
welding is generally applied to a butt joint and a lap joint, and
is described in WO 93/10935 (which is the same as EP 061 5480B1 and
the Japanese Announcement laid-open publication No. Hei 7-505090
and in the publication Welding & Metal Fabrication, January
1995, pp. 13-16.
SUMMARY OF THE INVENTION
[0005] In friction stir welding, the reaction of the plasticized
metal being extruded from immediately beneath the rotating tool
(round rod) to the surface during the welding results in a downward
force acting on the joint region. Thus, when this welding method is
applied to a two-face structure (panel), this downward force causes
the joint material at the joint region to flow downward, deforming
the joint. This makes it impossible to produce a satisfactory weld.
Two-face structures (panels) include hollow members made of
extruded aluminum alloy and honeycomb panels. Joining such panels
has been accomplished by MIG welding and TIG welding. When friction
stir welding is applied to such a joint, the joint is bent down or
the material in the joint region is forced to flow down due to a
downward force produced during the friction stir welding.
[0006] The inventor has found the above phenomena in a variety of
experiments.
[0007] It is a first object of this invention to provide a
satisfactory welded joint by minimizing deformation of the joint
region when two faces are friction stir welded.
[0008] It is a second object of this invention to provide a
satisfactory welded joint when one face is friction stir
welded.
[0009] It is a third object of this invention to enable two faces
to be welded together in a short time with little deformation.
[0010] The first object can be achieved by placing at the joint
region a connecting member that joins two plates forming two
faces.
[0011] The second object is realized by providing the members at
the joint region with a raised portion that protrudes toward the
friction stir welding tool side.
[0012] The third object is realized by disposing rotary tools for
friction stir welding on both sides of the objects to be welded,
placing the rotation center of one of the tools on an extension of
the rotation center of the other tool, and performing friction stir
welding simultaneously.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] FIG. 1 is a vertical cross section of one embodiment of this
invention.
[0014] FIG. 2 is a vertical cross section of FIG. 1 after friction
stir welding.
[0015] FIG. 3 is a vertical cross section of another embodiment of
this invention.
[0016] FIG. 4 is a vertical cross section of FIG. 3 after friction
stir welding.
[0017] FIG. 5 is a vertical cross section of another embodiment of
this invention.
[0018] FIG. 6 is a vertical cross section of FIG. 5 after friction
stir welding.
[0019] FIG. 7 is a vertical cross section of still another
embodiment of this invention.
[0020] FIG. 8 is a vertical cross section of FIG. 7 after friction
stir welding.
[0021] FIGS. 9(A) to 9(D) are vertical cross sections showing steps
in the procedure of friction stir welding of a further embodiment
of this invention.
[0022] FIG. 10 is a vertical cross section of a further embodiment
of this invention.
[0023] FIG. 11 is a vertical cross section of a further embodiment
of this invention.
[0024] FIG. 12 is a vertical cross section of a further embodiment
of this invention.
[0025] FIG. 13 is a vertical cross section of a further embodiment
of this invention.
[0026] FIG. 14 is a vertical cross section of a further embodiment
of this invention.
[0027] FIG. 15 is a perspective view of a structural body of a
railway car.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0028] The embodiment shown in FIG. 1 has a joint configuration of
the abutting type between hollow members 31, 32 which are in the
form of panels. The hollow members 31, 32 have vertical plates 36,
36 at their ends in the width direction. Before the welding, the
vertical plates 36, 36 are disposed immediately beneath a rotary
tool 50. The vertical plates 36, 36 are opposed to and in contact
with each other. If they are spaced apart, the distance is small
and approximately 1 mm. On the extension of the interface between
the vertical plates 36, 36 lies the center of a projection 52. The
vertical plates 36, 36 have a stiffness which is sufficiently
strong to sustain the downward force mentioned earlier. The
vertical plates 36 are perpendicular to two plates 33, 34 in each
panel. The hollow members 31, 32 are formed by extruding an
aluminum alloy. The upper and lower faces of the hollow member 31
are flush with the corresponding upper and lower faces of the
hollow member 32.
[0029] That is, the hollow members 31, 32 have the same thickness.
This is true also of the succeeding embodiments. During the
friction stir welding process, the boundary 53 between a
large-diameter portion 51 and the projection 52 of a small-diameter
of the rotary tool 50 is situated above the upper surfaces of the
hollow members 31, 32. Numeral 35 designates a plurality of members
that are arranged in the form of trusses to connect the two plates
36, 36. The hollow members 31, 32 each have bilaterally symmetrical
end portions and are mounted on a bed (not shown) where they are
fixed immovably. The bed also lies under the vertical plates 36,
36.
[0030] The friction stir welding process is performed by rotating
the tool 50, plunging the projection 52 into the joint region of
the hollow members 31, 32, and moving the projection 52 along the
joint region. The rotating center of the projection 52 is located
between the two vertical plates 36, 36.
[0031] FIG. 2 shows the two panels after they have been friction
stir welded. Reference number 45 denotes the shape of a weld bead
after welding. On the extension of the border line between the
vertical plates 36, 36 the width center of the weld bead 45 is
situated. The bead 45 lies in an area on the extension of the
thickness of the vertical plates 36, 36. The depth of the weld bead
45 is determined by the height of the projection 52 at the lower
end of the rotary tool 50 inserted in the joint region.
[0032] With this construction, because the vertical plates 36, 36
perpendicular to the plates 33, 34 sustain the vertical force
produced during the friction stir welding, the joint region does
not bend, offering a satisfactory joint as shown in FIG. 2. The
vertical plate 36 is made perpendicular to the plates 33, 34 in
each panel as much as possible.
[0033] The vertical plate 36 may be perforated to achieve a lighter
weight. This is true also of the succeeding embodiments.
[0034] Welding of the lower side is carried out by turning the
hollow panel members upside down after the welding of the one side
is completed.
[0035] The embodiment of FIG. 3 has a vertical plate 36 at the end
of one hollow member 31, but not at the opposing end of the other
hollow member 32. Corners in the vertical direction of the vertical
plate 36 of the hollow member 31 are recessed so as to receive the
ends of projecting pieces 38, 38 of the hollow member 32. These
recessed portions are open in a direction of the thickness of the
hollow member 31 and in a direction perpendicular to the thickness
direction (toward the hollow member 32 side). When the projecting
pieces 38 are placed (superposed) on the recessed portions, there
is actually a clearance between them although they are in contact
with each other in the figure. There is also a gap between the
front ends of these members (i.e., between the projecting pieces
38, 38 and the corners 33a, 34b). The abutting joint portions on
the upper face side of the two hollow members 31, 32 and the
vertical plate 36 are situated directly below the center of the
rotary tool 50. The rotating center of the projection 52 of the
welding tool 50 is disposed on an extension of the center line of
the thickness of the vertical plate 36. That is, the joint region
of the plate 33 (34) and plate 33 (34) is situated on the extension
of the center line of the thickness of the vertical plate 36. The
corners 33b, 34b extending from the plates 33, 34 to the recessed
portions lie on an extension of the center line of the thickness of
the vertical plate 36. Considering the gap between the corners 33b,
34b and the projecting pieces 38, the corners 33b, 34b are situated
slightly to the left of the extension of the center line of the
thickness of the vertical plate 36. The vertical plate 36 has a
rigidity to support the downward force. The horizontal gap between
the front ends of the projecting pieces 38 and the hollow member 31
is similar to that shown in FIG. 1. The height of the projection 52
of the welding tool 50 is approximately equal to the thickness of
the projecting piece 38. The region that is plastic and fluid
extends below the projecting piece 38, and comes to have an area
larger than the diameter of the projection 52, and the two hollow
members 31, 32 are friction stir welded. It is desirable that the
friction stir weld be so formed as to extend beyond the contact
area between the underside of the projecting piece 38 and the
vertical plate 36.
[0036] FIG. 4 shows the state of the joint after being welded. The
weld bead 45 is formed such that the width center of the weld bead
45 is situated on an extension of the thickness center of the
vertical plate 36.
[0037] To support the vertical force, it is desirable for the
rotating center of the tool 50 to be located on the extension of
the center line of the thickness of the vertical plate 36. To make
the quantity of the joint of the left and right hollow members 31,
32 equal, it is desirable for the corners 33b, 34b to be situated
on the extension of the thickness center line of the vertical plate
36. While the projection 52 of the tool 50 should preferably be
placed in the range between extension lines of the thickness of the
vertical plate 36, the thickness of the vertical plate 36 is
determined by the vertical force, the position of the projection 52
and the strength of the vertical plate 36. Hence, there may be a
case in which the thickness of the plate 36 is smaller than the
diameter of the projection 52. In view of the possible errors of
the position of the rotary tool 50 and those of the corners 33b,
34b, it is desirable for the corners 33b, 34b to be positioned in
the range between extension lines of the thickness of the vertical
plate 36, and at least a part of the projection 52 of the tool 50
to be situated in this range. This arrangement enables the vertical
plate 36 to receive at least a part of the vertical force,
substantially preventing the deformation of the joint. As a result,
a satisfactory joint can be formed. When the bead 45 is taken as a
reference, although the bead 45 is slightly larger than the
projection 52, the same as above can be said. This is true also of
the other embodiments.
[0038] Compared with the case of FIG. 1, this joint configuration
can minimize a sinking in the surface of the joint region even when
the horizontal gap between the projecting piece 38 and the hollow
member 31 is large. As a result, the joint has a good appearance
and requires a reduced amount of putty for painting. This is
because the gap between the two members is terminated at a depth
equal to the thickness of the projecting piece 38. It is also
considered that this joint configuration can reduce the weight.
Further, because one of the hollow members is fitted into the
other, the positioning in the height direction of the two members
can be accomplished easily. The ends of the hollow member 31 are
bilaterally symmetrical in shape.
[0039] The ends of hollow member 32 are also bilaterally
symmetrical. Alternatively, the hollow member 31 may have one end
shaped as shown in FIG. 3 and the other end shaped like the end of
the hollow member 32 of FIG. 3.
[0040] In the embodiment of FIG. 5, there is virtually no vertical
plate 36 immediately below the corners 33b, 34b of the recessed
portion of the hollow member 31. The right end of the vertical
plate 36 lies on the extension of the corners 33b, 34b. On this
extension the rotating center of the tool 50 is located. The end
portion of the hollow member 31 is given a rigidity to sustain the
vertical force by making the lower projecting piece 37 at the joint
thicker and increasing the size of the arcs extending from the
front ends of the projecting pieces 37 to the plate 36. The
projecting pieces 38 of the other hollow member 32 are received in
the recessed portions of the projecting pieces 37, as in the
preceding embodiment of FIG. 3. The second hollow member 32 has a
vertical plate 36 near the projections 38 for connecting the upper
and lower plates 33, 34. This arrangement prevents the joint region
from being defective even when there is no vertical plate 36
directly below the corners of the recessed portions. It is noted,
however, that below the range of the bead 45 there is a vertical
plate 36 of the panel 31. FIG. 6 shows the state after welding.
[0041] In the embodiment of FIG. 5, the plate 36 of the hollow
member 32 may be removed.
[0042] FIG. 7 shows another embodiment, representing a variation of
the preceding embodiment of FIG. 5, in which the joint region of
the two hollow members 31, 32 is provided with raised portions 37a,
38a protruding outside. This makes the joint region thick. The
heights of the raised portions 37a, 38a are equal. Other parts are
similar to those of FIG. 5, except that the vertical plate 36 and
the projections 37 are slightly thinner.
[0043] With this configuration, if there is a gap between the
raised portions 37a and 38a before welding, the gap is filled with
the material of the raised portions 37a, 38a, when welded,
improving the appearance and reducing the amount of putty
required.
[0044] In conventional welded joints, the weld bead has a sunken
portion or recess corresponding to the volume of the lost material
41 that has flowed down due to the downward force. In the joint
configuration of FIG. 7, the rotary tool 50 plasticizes the raised
portions 37a, 38a and forces them downward making up for the lost
volume of the material 41. Thus, formation of recess can be
prevented, providing a satisfactory welded joint. FIG. 8 shows the
shape of bead 45 after welding. After welding, unnecessary parts,
if any, are cut off as shown.
[0045] The raised portions 37a, 38a can also be applied to the
embodiments of FIGS. 1, 3 and 5 and to subsequent embodiments.
[0046] FIGS. 9(A)-9(D) show a further embodiment, which allows
welding at the upper and lower faces from only one side. The ends
of the hollow members 31, 32 on the lower side having projecting
pieces 34a, 34a protruding flush with the lower plates 34, 34
substantially toward the opposing hollow member sides. The front
ends of the projecting pieces 34a, 34a are virtually in contact
with each other. The front ends of the upper plates 33, 33 are
offset back from the front ends of the lower plates 34a, 34a. The
front ends of the upper plates 33, 33 are connected to the lower
plates 34, 34 through the vertical plates 36, 36. The vertical
plates 36, 36 are connected to intermediate portions of the lower
plates 34. The top portions of the vertical plates 36, 36 are
provided with recessed portions 39, 39 that receive a joint 60.
When mounted on the recessed portions 39, 39, the upper surface of
the joint 60 is flush with the upper face of the upper plates 33,
33. The distance between the two vertical plates 36, 36 is long
enough for the rotary tool 50 to be inserted and is as short as
possible. The relation between the vertical plates 36 and the
recessed portions 39 is the same as explained with reference to the
embodiments of FIG. 5 and FIG. 7.
[0047] The welding procedure will be described below. In the state
of FIG. 9(A), the abutting ends of the lower plates 34a, 34a are
welded by the rotary tool 50. At this time, the hollow members 31,
32, including the joint region of the plates 34a, 34a, are mounted
on a bed. The upper surface of the bed (that backs the bead) is
flat. The height of the projection 52 of the rotary tool 50 is
smaller than the thickness of the plates 34a, 34a. This design
ensures that the bottom surface after welding is flat. Thus, the
bottom side can easily be used as an outer surface of the structure
of a railway car or a building (the outer surface being the surface
on which no decorative plate is mounted). Generally, the upper face
of the friction stir welded joint tends to be uneven (at a boundary
portion 51).
[0048] Next, as shown in FIG. 9(B), the joint 60 is mounted between
the two hollow shape members 31, 32. The joint 60 in the
illustrated example is T-shaped in vertical cross section. When
both ends of the joint 60 are placed on the recessed portions 39,
39, the lower end of a vertical portion 61 has a clearance between
it and the weld bead on the lower plate. The vertical portion 61
may be omitted.
[0049] Next, as shown in FIG. 9(C), the joint portion between the
joint 60 and the hollow member 31 is friction stir welded by the
rotary tool 50. The rotary tool 50 need not be the same as used for
the weld illustrated in FIG. 9(A).
[0050] Then, as shown in FIG. 9(D), the joint portion between the
joint 60 and the hollow member 32 is friction stir welded by the
rotary tool 50.
[0051] This procedure allows the welding to be performed from one
side and eliminates the need for inversion of the panels. With the
inversion of the panels eliminated, there is an advantage that the
time required for inversion and positioning and need for an
inversion device are unnecessary, and even the assembly precision
is improved.
[0052] FIG. 10 shows another embodiment, in which both the upper
and lower sides of the hollow members 51, 52 are friction stir
welded at the same time. A rotary tool 50a for the lower side is
disposed vertically below the welding tool 50 for the upper side.
The projection 52 of the second welding tool 50a faces up. The two
welding tools 50, 50a facing each other are moved at the same speed
to perform friction stir welding. Denoted by 70, 70 are beds
(tables). The rotating centers of the tools 50 and 50a are on the
same line on which the joint region of the hollow shape members 31,
32 is located.
[0053] Because with this arrangement the rotating center of the
second tool 50a is positioned on the extension of the rotating
center of the first tool 50, the forces applied to the panels
balance with each other allowing the joint to be welded in a short
time with little deformation. Further, because there is no need to
invert the hollow members 31, 32, the welding can be performed in a
short time with little deformation of the joint.
[0054] This procedure can be applied to other embodiments.
[0055] The preceding embodiments have used hollow members as panels
to be joined. The following embodiments show friction stir welding
as applied to honeycomb panels. As shown in FIG. 11, the honeycomb
panels 80a, 80b comprise two surface plates 81, 82, core members 83
having honeycomb-like cells, and edge members 84 arranged along the
edges of the surface plates 81, 82, with the core members 83 and
the edge members 84 soldered to the surface plates 81, 82 to form
integral structures. The surface plates 81, 82, the core members 83
and the edge members 84 are made of aluminum alloy. The edge
members 84 are made by extrusion and have a rectangular cross
section. All sides of this rectangular cross section are greater in
thickness than the surface plates 81, 82. The vertical sides of the
mutually contacting edge members 84, 84 have the same thickness as
shown in FIG. 1. The two honeycomb panels 80a, 80b have the same
thickness.
[0056] The welding procedure in the embodiment of FIG. 11
corresponds to the one shown in FIG. 1. The height of the
projection 52 of the rotary tool 50 is larger than the thickness of
the face plates 81, 82. This allows the face plates 81, 82 and the
edge members 84, 84 to be welded. The load acting on the panels
80a, 80b is transmitted mainly by the edge members 84. After being
fabricated, the panels 80a, 80b are assembled and friction stir
welded.
[0057] The embodiment of FIG. 12 corresponds to the one shown in
FIG. 3. The edge member 84 of the honeycomb panel 80a has a
generally rectangular cross section and has recesses at the
corners. The edge member 84 of the honeycomb panel 80b is like a
channel, with its opening facing the honeycomb panel 80a. The open
ends of the edge member 84 are mounted on the recessed portions of
the edge member 84 of the honeycomb panel 80a.
[0058] The honeycomb panel corresponding to FIG. 5 can be
fabricated in a similar manner.
[0059] FIG. 13 shows still another embodiment that corresponds to
FIG. 7. After two honeycomb panels 80a, 80b are assembled, a plate
86 is placed on the face plates 81, 81 and temporarily welded to
them. The plate 86 makes up for the material that is plasticized
and flows out. In FIG. 12, one vertical piece of the edge member of
the honeycomb panel 80a is removed. The vertical force is supported
by the thickness of the horizontal piece of the edge member 84 and
the surrounding parts.
[0060] FIG. 14 shows a further embodiment of this invention. The
preceding embodiments up to FIG. 13 include panels having two faces
(face plates), whereas the embodiment of FIG. 14 includes panels
91, 92 having virtually a single face (face plates 94, 94).
Friction stir welding is performed at two locations, at the
abutting ends of the panels 91, 92, the outside with face plates 94
and the inner side with no face plates. Therefore, the joint
regions on the inner side are provided with narrow face plates
(face plates 93, 93). The narrow face plates 93, 93 are supported
by vertical plates 96, 96. In this example, too, the vertical
plates 96 are virtually perpendicular to the face plates 93,94. The
face plates 93, 94 are provided with raised portions 37a, 38a
similar to the ones shown in FIG. 7. The face plates 94, 94 have a
plurality of reinforcing ribs (plates) 95, 95 at specified
intervals. The ribs 95 are T-shaped in cross section. The top
surfaces of the ribs 95 are flush with those of the face plates 93
of the joint region. To the top surfaces reinforcing members (such
as pillars) may be welded, or the top surfaces serve as mounting
seats for articles. Further, the face plates 93, 93 also serve as a
seat for controlling the height of the tool 50. A movable body
carrying the tool 50 travels along the face plates 93, 93. Because
of the provision of the face plates 93, 94, the panels 91, 92 can
also be said to form a two-face structure. The panels 91, 92 are
extruded shape members.
[0061] While FIG. 14 shows the vertical plates 96, 96 of the panels
91 and 92 opposing each other at the joint region, as in the
configuration of FIG. 1, it is possible to place one of the
vertical plates over the other, as shown in FIGS. 3, 5 and 7.
[0062] FIG. 15 shows an example of application of this invention to
the structural body of a railway car. The structural body has side
bodies 101, a roof body 102, a floor body 103, and gable bodies 104
at the ends in the longitudinal direction. The side bodies 101 and
the roof body 102 have panels 31, 32, 80a, 80b, 91, 92 whose long
sides are oriented in the longitudinal direction of the car. The
joint between the side bodies 101 and the roof body 102 and between
the side bodies 101 and the floor body 103 is accomplished by MIG
welding. The roof body 102 and the side bodies 101 are often shaped
into arcs in cross section. When the panels 91, 92 are used for the
side bodies 101, the side having the vertical plates 96 and ribs 96
is made to face to the interior of the car and the reinforcing
members constitute pillars.
[0063] The panels 31, 32 of FIG. 9 may be combined in a
mirror-image arrangement. The end of the projecting plate 34a of
each panel is placed on the recessed portion 39 of the plate 33 of
the other panel. This obviates the use of the joint 60 and allows
for simultaneous friction stir welding of the joint region both
from above and below. The plates 33, 34a can be provided with
raised portions, as shown in FIG. 7.
* * * * *