U.S. patent application number 16/089413 was filed with the patent office on 2019-11-07 for member joining method.
The applicant listed for this patent is Nissan Motor Co., Ltd.. Invention is credited to Yutaka YANO.
Application Number | 20190338795 16/089413 |
Document ID | / |
Family ID | 60161418 |
Filed Date | 2019-11-07 |
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United States Patent
Application |
20190338795 |
Kind Code |
A1 |
YANO; Yutaka |
November 7, 2019 |
MEMBER JOINING METHOD
Abstract
A member joining method includes applying a first resin member
to a first member and a second resin member to a second member and
joining end portions of the first and second members together. The
member joining method further includes integrally joining the first
resin member of the first member and the second resin member of the
second member by heat deformation to mix arid cure areas adjacent
the end portions at a time of coating.
Inventors: |
YANO; Yutaka; (Kanagawa,
JP) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Nissan Motor Co., Ltd. |
Yokohama-shi,Kanagawa |
|
JP |
|
|
Family ID: |
60161418 |
Appl. No.: |
16/089413 |
Filed: |
April 28, 2016 |
PCT Filed: |
April 28, 2016 |
PCT NO: |
PCT/JP2016/063364 |
371 Date: |
September 28, 2018 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
B29C 44/128 20130101;
B62D 29/005 20130101; B62D 27/023 20130101; B29C 65/02 20130101;
B29C 66/5221 20130101; B62D 29/002 20130101; B62D 25/04 20130101;
F16B 11/006 20130101; B29C 69/00 20130101; B62D 27/026 20130101;
B29C 44/18 20130101 |
International
Class: |
F16B 11/00 20060101
F16B011/00; B62D 25/04 20060101 B62D025/04; B62D 27/02 20060101
B62D027/02 |
Claims
1. A member joining method wherein a first member and a second
member each includes an outer member and an inner member, which
form a closed cross-sectional space therebetween, and the member
joining method comprising: a step of arranging a first resin member
on either the outer member or the inner member of the first member;
a step of arranging a second resin member on either the outer
member or the inner member of the second member, which is on the
same side as the outer member or the inner member of the first
member on which the first resin member is disposed; a step of
joining to each other end portions of one of the outer member and
the inner member of the first member on which the first resin
member is disposed, and one of the inner member and the outer
member of the second member on which the second resin member is
disposed; a step of joining the outer member and the inner member
of the first member to cover the first resin member; a step of
joining the outer member and the inner member of the second member
to cover the second resin member; and a step of integrally joining
the first resin member positioned in the closed cross-sectional
space of the first member and the second resin member positioned in
the closed cross-sectional space of the second member by heat
deformation to mix and cure areas adjacent the end portions thereof
at a time of coating.
2. The member joining method according to claim 1, wherein the
first resin member and the second resin member are foamable epoxies
that foam when heated.
3. The member joining method according to claim 1, wherein the
first member and the second member are included in a front pillar
of an automobile.
4. (canceled)
5. The member joining method according to claim 2, wherein the
first member and the second member are included in a front pillar
of an automobile.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a U.S. national stage application of
International Application No. PCT/JP2016/063364, filed on Apr. 28,
2016.
BACKGROUND
Field of the Invention
[0002] The present invention relates to a member joining method for
joining members to each other.
Background Information
[0003] Japanese Laid Open Patent Application No. 61-116509 (Patent
Document 1) discloses filling a pillar with a foam by injecting a
foamed polyurethane into a pillar of an automobile body.
SUMMARY
[0004] The technique disclosed in Patent Document 1 provides a
vibration proofing and soundproofing effect by filling a pillar
with a foam, but does not consider improving the joining strength
between the members.
[0005] Therefore, an object of the present invention is to improve
the joining strength between members.
[0006] In the present invention, the end portions of a first member
and a second member are joined to each other, and a first resin
member and a second resin member inside the first member and the
second member are integrated by means of heat deformation when
coated onto the first member and the second member.
[0007] According to the present invention, the first member and the
second member, whose end portions are joined to each other, are
integrated by the first resin member and the second resin member
being joined; therefore, the joining strength between the two is
improved.
BRIEF DESCRIPTION OF THE DRAWINGS
[0008] FIG. 1 is an exploded perspective view before joining a
first member and a second member according to the member joining
method of one embodiment of the present invention.
[0009] FIG. 2 is a perspective view illustrating a state after the
first member and the second member of FIG. 1 have been joined.
[0010] FIG. 3 is a perspective view illustrating a state in which a
plate member of the second member of FIG. 2 is joined to a bent
member.
[0011] FIG. 4 is a perspective view illustrating a state in which
foamable epoxies inside the first member and the second member
receive heat and are foamed and integrated.
[0012] FIG. 5 is a side view illustrating an example in which the
member joining method of the present invention is applied to a
front pillar of an automobile as seen from the outside of the
vehicle body.
[0013] FIG. 6 is a perspective view of the periphery of the front
pillar of FIG. 5 as seen from the front of the vehicle body.
[0014] FIG. 7 is a perspective view of the periphery of the front
pillar of FIG. 5 as seen from the inside of the vehicle body.
[0015] FIG. 8 is a cross-sectional view of the front pillar taken
along line A-A in FIG. 7.
[0016] FIG. 9 is a cross-sectional view of the front pillar taken
along line B-B in FIG. 7.
[0017] FIG. 10 is an assembly process view, illustrating a state in
which foamable epoxy is disposed on a pillar base portion of the
front pillar and on each outer member of a pillar body.
[0018] FIG. 11 is an assembly process view, illustrating a state in
which the pillar base portion and the outer members of the pillar
body are joined to each other by means of welding from the state of
FIG. 10.
[0019] FIG. 12 is a side view illustrating each inner member that
is joined to each outer member of FIG. 11 from the inner side of
the vehicle.
[0020] FIG. 13 is an assembly process view, illustrating a state in
which each inner member of FIG. 12 is joined to each outer member
of the pillar body and the pillar base portion illustrated in FIG.
11 by means of welding.
DETAILED DESCRIPTION OF THE EMBODIMENTS
[0021] Embodiments for implementing the present invention are
described in detail below with reference to the drawings.
[0022] The first member 1 and the second member 3 shown in FIG. 1
are integrated by the end portions thereof being joined to each
other, as illustrated in FIG. 3. The first member 1 is made of
metal and is composed of a bent member 5 having a hat-shaped cross
section, and a rectangular plate member 7. The bent member 5 has an
open portion 5a on one side surface, and forms a rectangular closed
cross-sectional space 9 with the plate member 7 by welding and
securing the plate member 7 so as to close the open portion 5a.
[0023] In the same manner, the second member 3 is also made of
metal and is composed of a bent member 11 having a hat-shaped cross
section, and a rectangular plate member 13. The bent member 11 has
an open portion 11 a on one side surface, and forms a rectangular
closed cross-sectional space 15 with the plate member 13 by
securing the plate member 13 by welding so as to close the open
portion 11a.
[0024] As illustrated in FIG. 1, the first member 1 accommodates a
foamable epoxy 17 prior to foaming as a first resin member adjacent
an opening 9a corresponding to one end portion of the closed
cross-sectional space 9 inside the bent member 5, before the plate
member 7 is secured by welding to the bent member 5. The foamable
epoxy 17 has a cross-sectional shape consisting of a cube or a
rectangular parallelepiped equivalent to that of the closed
cross-sectional space 9, and the outer surface thereof is
substantially in close contact with the inner surfaces of the bent
member 5 and the plate member 7.
[0025] A positioning hole 5b1 is formed on the surface 5b on the
opposite side of the open portion 5a of the bent member 5. On the
other hand, a positioning protrusion 17a is provided on a side of
the foamable epoxy 17 opposite the open portion 5a. By pushing and
inserting the foamable epoxy 17 from the open portion 5a of the
bent member 5, the protrusion 17a is inserted and positioned in the
positioning hole 5b1.
[0026] Then, flanges 5c, 5d of the bent member 5 and the plate
member 7 are joined and secured by welding. At this time, the
opening 9a side end portions of the bent member 5 and the plate
member 7 are in the same surface position, and these end portions
and the end surface of the foamable epoxy 17 are substantially
matched to be in substantially the same surface position.
[0027] As illustrated in FIG. 1, the bent member 11 of the second
member 3 has an expanded portion 19 that is formed by bending an
opening 15a side, corresponding to one end portion of the closed
cross-sectional space 15 inside the bent member 11, so as to expand
outward over the entire perimeter. The end portion of the first
member 1 on the opening 9a side is inserted into the expanded
portion 19, as illustrated in FIGS. 2 and 3. The plate member 13
has a bent portion 13a corresponding to the expanded portion 19,
which is bent in a direction away from the expanded portion 19.
[0028] The second member 3 accommodates a foamable epoxy 21 prior
to foaming as a second resin member adjacent an opening 15a
corresponding to one end portion of the closed cross-sectional
space 15 inside the bent member 11, in a position interfering with
the expanded portion 19, before the plate member 13 is joined and
secured to the bent member 11. The foamable epoxy 21 has a
cross-sectional shape consisting of a cube or a rectangular
parallelepiped equivalent to that of the closed cross-sectional
space 15, and the outer surface thereof is substantially in close
contact with the inner surfaces of the bent member 11 and the plate
member 13.
[0029] A positioning hole 11b1 is formed on the surface 11b on the
opposite side of the open portion 11 a of the bent member 11. On
the other hand, a positioning protrusion 21a is provided on a side
of the foamable epoxy 21 opposite the open portion 11a. By pushing
and inserting the foamable epoxy 21 from the open portion 11a of
the bent member 11, the protrusion 21a is inserted and positioned
in the positioning hole 11b1.
[0030] Then, the end portion of the first member 1 on the side of
the opening 9a is inserted and disposed inside the expanded portion
19 of the bent member 11, and secured by welding, as illustrated in
FIG. 2. In as state in which the first member and the bent member
11 of the second member 3 are secured by welding as illustrated in
FIG. 2, the flanges 11c, 11d of the bent member 11 and the plate
member 13 are joined and secured by welding, as illustrated in FIG.
3. At this time the bent portion 13a of the plate member 13 is
positioned overlapping the plate member 7 in a position
corresponding to the expanded portion 19, and then secured by
welding.
[0031] In the state shown in FIG. 3, a gap 23 is formed between the
foamable epoxy 17 and the foamable epoxy 21. In order to form the
gap 23, the foamable epoxy 21 is disposed at a position that is
slightly separated from the expanded portion 19.
[0032] In the state shown in FIG. 3, a joined member 25, which is
obtained by welding and joining the first member 1 and the second
member 3, is heated at the time of coating, for example, in a
curing step, and the foamable epoxies 17, 21 therein are also
heated. The foamable epoxies 17, 21 foam and expand when heated,
and the mutually opposing portions approach each other so as to
fill the gap 23, and, in due time, come into contact and adhere to
each other. At this time the foamable epoxies 17, 21 are deformed
by receiving heat, and the areas adjacent the end portions of on
the sides of the openings 9a, 15a mix together and harden, thereby
enabling joining and integration.
[0033] Due to expansion at the time of foaming, the outer
peripheral surfaces of the foamable epoxies 17, 21 are respectively
pushed against, and thereby brought into close contact with and
joined to, the inner surfaces of the first member 1 and the second
member 3. FIG. 4 illustrates a joined foam 27 obtained when the
foamable epoxies 17, 21 are joined and integrated inside the joined
member 25.
[0034] Thus, in a state in which the first member 1 and the second
member 3 are joined by means of welding, the foamable epoxies 17,
21 disposed inside the closed cross-sectional spaces 9, 15,
respectively, are joined to each other and integrated to form the
joined foam 27. Consequently, in addition to the joining force due
to welding, the joining strength between the first member 1 and the
second member 3 resulting from the member joining method described
above is further improved by the joining force that is generated
due to the integration of the resin.
[0035] In the present embodiment, the foamable epoxies 17, 21 are
heated by the heat that is generated when coating the first member
1 and the second member 3, which are joined to each other.
Accordingly, it is unnecessary to provide additional equipment such
as a dedicated heating furnace, thus contributing to cost
reduction.
[0036] Because the strength after curing is higher compared to
other foam materials, such as foamable urethane, foamable epoxy 17,
21 is extremely effective for increasing the joining strength
between the first member 1 and the second member 3.
[0037] The foamable epoxies 17, 21 expand smoothly due to foaming
after heating, thanks to the gap 23 provided therebetween, as
illustrated in FIGS. 2 and 3. As a result, it becomes easy for the
foamable epoxies 17, 21 to mix at the time of foaming, which
further improves the joining strength.
[0038] In addition, by providing the gap 23, it becomes possible to
prevent the foamable epoxies 17, 21 from coming into contact with
each other when the first member 1 and the second member 3, in the
state shown in FIG. 1, are abutted to achieve the state shown in
FIG. 2. Accordingly, it becomes easy to insert and dispose the end
portion of the first member 1 in a specified position inside the
expanded portion 19 of the second member 3, and to reliably join
the first member 1 and the second member 3.
[0039] In the embodiment described above, when forming the gap 23,
the foamable epoxy 21 is disposed in a position separated from the
expanded portion 19. Alternatively, the foamable epoxy 17 can be
shifted from the end portion of the first member 1 on the opening
9a side so as to be positioned inside the closed cross-sectional
space 9.
[0040] Additionally, with regard to the second member 3 in the
embodiment described above the bent member 11 is joined to the
first member 1 before the plate member 13 is joined, as illustrated
in FIG. 2. Alternatively, the end portion of the first member 1 can
be inserted in a space surrounded by the bent portion 13a and the
expanded portion 19 of the second member 3 and joined, after the
plate member 13 has been joined to the bent member 11.
Alternatively, the bent members 5, 11 can be joined to each other
first before the plate members 7, 13 are respectively joined to the
corresponding bent members 5, 11, and then the plate members 7, 13
can be sequentially joined.
[0041] The foamable epoxies 17, 21 can be inserted and disposed
inside the bent members 5, 11 either before or after the bent
members 5, 11 are joined to each other, as long as it is before the
plate members 7, 13 are respectively joined to the corresponding
bent members 5, 11. In addition, the foamable epoxies 17, 21 can be
pushed and inserted into the closed cross-sectional spaces 9, 15
from, for example, the openings 9a, 15a, after the plate members 7,
13 are respectively joined to the corresponding bent members 5, 11
to form the closed cross-sectional spaces 9, 15. Instead of
providing positioning protrusions 17a, 21a, the foamable epoxies
17, 21 can be secured to the inner surfaces of the first member 1
and the second member 3 by an adhesive. Positioning protrusions
17a, 21a and an adhesive can both be used.
[0042] FIGS. 5-7 illustrate a state in which the joined member 25
obtained by joining the first member 1 and the second member 3
shown in FIG. 4 by means of welding is applied to a body member of
an automobile, corresponding to a state after the joining of FIG.
4. The body member here is a front pillar 31 of a body 29 of an
automobile, and the front pillar 31 includes a first member and a
second member. In the figure, the direction indicated by the arrow
FR is the front of the body, and the direction indicated by the
arrow UP is the upper direction of the body. FIG. 5 is a side view
of the inner side of the vehicle as seen from the outside of the
vehicle, and FIG. 7 is a side view of the outside of the vehicle as
seen from the inner side of the vehicle, in contrast with FIG.
5.
[0043] The front pillar 31 includes a pillar base portion 33
positioned on the lower front fender side, and a pillar body 35
positioned on the upper roof side. The front pillar 31 is
configured by joining the end portions of the pillar base portion
33 and the pillar body 35 to each other. The foamable epoxy 37 on
the pillar base portion 33 side and the foamable epoxy 39 on the
pillar body 35 side are joined, in a state in which the pillar base
portion 33 and the pillar body 35 are joined, to form a joined foam
41 that is similar to the joined foam 27 of FIG. 4. Either one of
the foamable epoxies 37, 39 constitutes the first resin member,
while the other constitutes the second resin member.
[0044] The pillar base portion 33 includes an outer member 43 on
the vehicle exterior OUT side, and an inner member 45 on the
vehicle interior IN side (dash side), as illustrated in FIG. 8,
which is a cross-sectional view taken along line A-A in FIG. 7.
When bent so as to protrude to the vehicle exterior OUT side, the
outer member 43 forms a closed cross-sectional space 47 with the
inner member 45. A reinforcing member 49 is provided on the inner
surface of a portion of the outer member 43 corresponding to the
closed cross-sectional space 47. The bracket 51 is joined and
secured to the outer member 43 at the joint portions 51a, 51b, as
illustrated in FIGS. 10 and 11, which are described later, and is
substantially in contact with the inner surface of the inner member
45, as illustrated in FIG. 8. Vehicle parts, which are disposed on
the vehicle interior IN side, and which are not shown, are attached
to the bracket 51.
[0045] A portion of the joined foam 41 corresponding to the
foamable epoxy 37 after foaming is disposed in the closed
cross-sectional space 47 illustrated in FIG. 8. In FIG. 8, a gap is
formed between the foamable epoxy 37 after foaming and the inner
wall of the closed cross-sectional space 47, but actually there is
almost no gap, and the epoxy and the inner wall are in close
contact.
[0046] A positioning hole 53 is provided by forming through-holes
43a and 49a in the outer member 43 and the reinforcing member 49,
respectively, as illustrated in FIG. 8. A positioning protrusion
37a, which is inserted into the positioning hole 53, is provided on
the foamable epoxy 37. The through-hole 49a is smaller than the
through-hole 43a, and when the positioning protrusion 37a has been
inserted into the positioning hole 53, the positioning protrusion
is locked in the through-hole 49a, and is prevented from falling
out. The lower positioning structure including the positioning
protrusion 37a and the positioning hole 53 is set in two locations
adjacent the two end portions of the foamable epoxy 37, in the
longitudinal direction, as illustrated in FIG. 5.
[0047] The pillar body 35 includes an outer member 55 on the
vehicle exterior OUT side, and an inner member 57 on the vehicle
interior IN side, as illustrated in FIG. 9, which is a
cross-sectional view taken along line B-B in FIG. 7. When bent so
as to protrude to the vehicle exterior OUT side, the outer member
55 forms a closed cross-sectional space 59 with the inner member
57. A portion of the joined foam 41 corresponding to the foamable
epoxy 39 after foaming is disposed in the closed cross-sectional
space 59. In FIG. 9, a gap is formed between the foamable epoxy 39
after foaming and the inner wall of the closed cross-sectional
space 59, but actually there is almost no gap, and the epoxy and
the inner wall are in close contact.
[0048] The outer member 55 is provided with a positioning hole 55a,
and the foamable epoxy 39 is provided with a positioning protrusion
39a, as illustrated in FIG. 5. The foamable epoxy 39 is positioned
on the outer member 55 by inserting the positioning protrusion 39a
into the positioning hole 55a. The upper positioning structure
including the positioning protrusion 39a and the positioning hole
55a is set in one location adjacent the end portion of the foamable
epoxy 39 on the far side from the foamable epoxy 37.
[0049] Next, the assembly procedure will be described with
reference to FIGS. 10-13.
[0050] FIG. 10 illustrates a state in which the foamable epoxy 37
and the foamable epoxy 39 before foaming are respectively disposed
on the outer member 43 of the pillar base portion 33 and the outer
member 55 of the pillar body 35. At this time, the positioning
protrusion 37a of the foamable epoxy 37 is inserted into the
positioning hole 53 and the positioning protrusion 39a of the
foamable epoxy 39 is inserted into the positioning hole 55a, to
thereby position the foamable epoxies 37, 39, as illustrated in
FIG. 8. When carrying out the positioning described above, a
portion of the foamable epoxy 37 is covered and held from the
vehicle interior IN side by an upper end portion of the bracket 51,
as illustrated in FIG. 10.
[0051] When being positioned on the outer member 43, the foamable
epoxy 37 is disposed in a position retracted inwardly from a joint
end portion 43b of the outer member 43, as illustrated in FIG. 10.
Conversely, when being positioned on the outer member 55, the
foamable epoxy 39 is disposed in a position protruding outwardly
from a joint end portion 55b of the outer member 55.
[0052] The foamable epoxy 37 is provided with a protruding portion
37b at an end portion on the joint end portion 43b side, which
protrudes toward the joint end portion 43b side on the lower side.
On the other hand, the foamable epoxy 39 is provided with a
recessed portion 39b on the vehicle exterior OUT side on the lower
side of an end portion on the side that protrudes outward. The
protruding portion 37b is inserted and disposed in the recessed
portion 39b.
[0053] From the state shown in FIG. 10, the outer member 43 of the
pillar base portion 33 and the outer member 55 of the pillar body
35 are joined by means of welding, by bringing the joint end
portions 43b, 55b close to each other in the state shown in FIG.
11. At this time, the respective end portions of the outer members
43, 55 overlap each other such that the outer member 43 of the
pillar base portion 33 is positioned closer to the vehicle interior
IN side (the front side of the page in FIG. 11) than the outer
member 55 of the pillar body 35. That is, the outer member 43 of
the pillar base portion 33 is inserted between the foamable epoxy
39 and the outer member 55 of the pillar body 35.
[0054] In a state in which the end portions of the outer members
43, 55 overlap each other, the protruding portion 37b of the
foamable epoxy 37 is inserted and disposed in the recessed portion
39b of the foamable epoxy 39, as illustrated in FIG. 11. When the
protruding portion 37b is inserted and disposed in the recessed
portion 39b, a lower surface 39b1 of the recessed portion 39b rests
on an upper surface 37b1 of the protruding portion 37b.
[0055] Additionally, in the state shown in FIG. 11 a distal end
surface 37b2 of the protruding portion 37b is separated from a
recess inner-end surface 39b2 of the recessed portion 39b, thus
forming a lower gap 61 therebetween. Furthermore, an end surface
39c of the foamable epoxy 39 on the side that protrudes outward is
separated from an end surface 37c of the foamable epoxy 37, thus
forming an upper gap 63 therebetween.
[0056] Because the foamable resin is provided with the positioning
structures at two locations configured by the two positioning
protrusions 37a with respect to the outer member 43, the position
of the foamable epoxy 37 is substantially fixed, as illustrated in
FIG. 5. However, by provided the positioning structure at one
location configured by one positioning protrusion 39a, on a side
away from the foamable epoxy 37, as illustrated in FIG. 5, it
becomes possible for the foamable epoxy 39 to be somewhat swingably
displaced in the vertical direction, with the positioning
protrusion 39a as the fulcrum.
[0057] As a result, the operation to place the lower surface 39b1
of the recessed portion 39b of the foamable epoxy 39 on the upper
surface 37b1 of the protruding portion 37b of the foamable epoxy 37
becomes easy, when joining the end portions of the outer member 43
of the pillar base portion 33 and the outer member 55 of the pillar
body 35 to each other.
[0058] Next, the inner member 45 and the inner member 57 shown in
FIG. 12 are placed on the outer member 43 and the outer member 55,
respectively, as shown in FIG. 11, so as to overlap each other, as
illustrated in FIG. 13, and the abutting portions are joined to
each other by means of welding. At this time, the end portion of
the inner member 57 is closer to the front surface side of the page
in FIG. 13 (vehicle interior IN side) than the end portion of the
inner member 45. As a result, the vehicle interior IN side of the
foamable epoxies 37, 39 are covered by the inner members 45, 57,
and will be housed and disposed inside the closed cross-sectional
spaces 47, 59. The foamable epoxies 37, 39 before foaming are
substantially in contact with, or form slight gaps with, the inner
wall surfaces of the respective closed cross-sectional spaces 47,
59, when accommodated and disposed in the closed cross-sectional
spaces 47, 59.
[0059] In the state shown in FIG. 13 the body 29 including the
front pillar 31 is heated at the time of coating, for example, in a
curing step, and the foamable epoxies 37, 39 therein are also
heated. The foamable epoxies 37, 39 foam and expand when heated,
and the mutually opposing portions approach each other so as to
fill the lower gap 61 and the upper gap 63, as illustrated in FIG.
11, and, in due time, come into contact and adhere to each other.
At this time, the foamable epoxies 37, 39 are deformed by receiving
heat, and the areas in the vicinities of the end portions of the
sides opposing each other, including the protruding portion 37b and
the recessed portion 39b, mix together and harden, thereby enabling
joining and integration to form a joined foam 41.
[0060] Additionally, due to expansion at the time of foaming, the
outer peripheral surfaces of the foamable epoxies 37, 39 are
respectively pushed against, and thereby brought into close contact
with and joined to, the inner wall surfaces of the closed
cross-sectional spaces 47, 59.
[0061] Thus, in a state in which the pillar base portion 33 and the
pillar body 35 of the front pillar 31 are joined by means of
welding, the foamable epoxies 37, 39 disposed inside the closed
cross-sectional spaces 47, 59 are joined to each other and
integrated so as to form the joined foam 41. Consequently, in
addition to the joining force due to welding, the joining strength
between the pillar base portion 33 and the pillar body 35 is
further improved by the joining force that is generated due to the
integration of the resin.
[0062] The first member and the second member whose end portions
are joined to each other are included in the front pillar 31 of the
body member. In this case, by increasing the joining strength
between the pillar base portion 33 and the pillar body 35 of the
front pillar 31, the crushing strength against a downward load
received by the roof of the body from above is increased.
[0063] In the member joining method for joining the pillar base
portion 33 and the pillar body 35 of the front pillar 31 described
above, the foamable epoxies 37, 39 are disposed on the outer
members 43, 55, respectively, before the end portions are joined to
each other. Thereafter, when the end portions of the outer members
43, 55 are joined to each other, the inner members 45, 57 are
joined to the outer members 43, 55, respectively. As a result, it
becomes possible to dispose the foamable epoxies 37, 39 in the
closed cross-sectional spaces 47, 59, which are formed between the
outer members 43, 55 and the inner members 45, 57. The end portions
of the foamable epoxies 37, 39 are reliably joined to each when
heated and foamed inside the closed cross-sectional spaces 47, 59
described above.
[0064] Embodiments of the present invention were described above,
but these embodiments are described in order to facilitate
understanding of the present invention, and the present invention
is not limited to the embodiments. The technical scope of the
present invention is not limited to the specific technical matters
disclosed in the above-described embodiments, and includes various
modifications, changes, and alternatives that can be easily derived
therefrom.
[0065] In the above-described embodiment, an example was described
in which foamable epoxy is used as the first resin member and the
second resin member, but the foam material is not limited to a
foamable epoxy. For example, the foam material can be foamable
urethane. In addition to a foam material, a resin member that is
joined by means of heating and glass transition or melting can be
used, for example nylon 66, which is a synthetic polyamide
fiber.
[0066] Since nylon 66 has flowability at the melting point, it
becomes necessary to provide a flow stopping member for preventing
outflow of molten resin on the opposite side of the joining surface
of the two resin members.
[0067] In the embodiment illustrated in FIGS. 5-11, the shapes of
the end portions of the foamable epoxies 37, 39 on the sides to be
joined are not limited to the shapes illustrated in FIGS. 10, 11.
For example, in the state shown in FIG. 11, the foamable epoxies
37, 39 may simply be respectively provided with flat joining
surfaces, with a gap therebetween, and without the protruding
portion 37b and the recessed portion 39b.
[0068] The present invention is applied to a member joining method
for joining members provided with closed cross-sectional
spaces.
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