U.S. patent application number 15/726172 was filed with the patent office on 2019-04-11 for net shaped substrate material for substrate joint.
This patent application is currently assigned to Ford Global Technologies, LLC. The applicant listed for this patent is Ford Global Technologies, LLC. Invention is credited to Amanda Kay Freis, Garret Sankey Huff.
Application Number | 20190105702 15/726172 |
Document ID | / |
Family ID | 65993758 |
Filed Date | 2019-04-11 |
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United States Patent
Application |
20190105702 |
Kind Code |
A1 |
Huff; Garret Sankey ; et
al. |
April 11, 2019 |
NET SHAPED SUBSTRATE MATERIAL FOR SUBSTRATE JOINT
Abstract
An assembly includes an upper substrate, a lower substrate, and
a self-piercing rivet. The lower substrate defines a preformed
interior cavity and a preformed exterior profile adjacent the
interior cavity to define a variable thickness wall. The
self-piercing rivet extends through the upper substrate and into
the preformed interior cavity of the lower substrate.
Inventors: |
Huff; Garret Sankey; (Ann
Arbor, MI) ; Freis; Amanda Kay; (Ann Arbor,
MI) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Ford Global Technologies, LLC |
Dearborn |
MI |
US |
|
|
Assignee: |
Ford Global Technologies,
LLC
Dearborn
MI
|
Family ID: |
65993758 |
Appl. No.: |
15/726172 |
Filed: |
October 5, 2017 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
F16B 5/04 20130101; B21C
23/142 20130101; B29C 65/64 20130101; B21J 15/147 20130101; B21J
15/025 20130101; B29C 66/742 20130101; B29L 2031/3002 20130101 |
International
Class: |
B21J 15/02 20060101
B21J015/02 |
Claims
1. An assembly comprising: an upper substrate; a lower substrate
defining a preformed interior cavity and a preformed exterior
profile adjacent the interior cavity to define a variable thickness
wall; and a self-piercing rivet extending through the upper
substrate and into the preformed interior cavity of the lower
substrate.
2. The assembly according to claim 1, wherein the preformed
interior cavity of the lower substrate is not plastically deformed
after installation of the self-piercing rivet.
3. The assembly according to claim 1, wherein the preformed
interior cavity of the lower substrate is plastically deformed
after installation of the self-piercing rivet.
4. The assembly according to claim 1, wherein the lower substrate
is an aluminum casting or an aluminum extrusion.
5. The assembly according to claim 1, wherein the lower substrate
is a composite material.
6. The assembly according to claim 1, wherein the preformed
interior cavity defines a circular trench having a raised central
region.
7. The assembly according to claim 1, wherein the preformed
exterior profile defines a closed cylinder.
8. The assembly according to claim 7, wherein the preformed
exterior profile further defines a radiused area extending between
a lower surface of the lower substrate and the cylinder.
9. The assembly according to claim 1, wherein the preformed
interior cavity is configured to direct flaring of the
self-piercing rivet.
10. A dimpled substrate for use in an assembly having joined
substrates, the dimpled substrate defining at least one preformed
interior cavity and at least one preformed exterior profile
adjacent the interior cavity to define a variable thickness wall,
wherein the preformed interior cavity is configured to receive a
fastening system that plastically deforms at least one of the
substrates during joining.
11. The substrate according to claim 10, wherein the dimpled
substrate defines a plurality of preformed interior cavities and a
corresponding plurality of preformed exterior profiles, the
plurality of preformed interior cavities being evenly spaced.
12. The substrate according to claim 10, wherein the lower
substrate is an aluminum casting or an aluminum extrusion.
13. The substrate according to claim 10, wherein the lower
substrate is a composite material.
14. The substrate according to claim 10, wherein the preformed
interior cavity defines a circular trench having a raised central
region.
15. The substrate according to claim 10, wherein preformed exterior
profile defines a closed cylinder.
16. An assembly comprising: an upper substrate; a lower substrate
defining a plurality of preformed interior cavities and a
corresponding plurality of preformed exterior profiles adjacent the
interior cavities to define variable thickness walls therebetween;
and a plurality of self-piercing rivets extending through the upper
substrate and into the preformed interior cavities of the lower
substrate, wherein the preformed interior cavities are configured
to direct flaring of the self-piercing rivets.
17. The assembly according to claim 16, wherein the lower substrate
is an aluminum casting or an aluminum extrusion.
18. The assembly according to claim 16, wherein the lower substrate
is a composite material.
19. The assembly according to claim 16, wherein preformed exterior
profiles define closed cylinders.
20. A motor vehicle having the assembly according to claim 16.
Description
FIELD
[0001] The present disclosure relates to the joining of various
materials in an assembly, including dissimilar materials having
advanced high strength and light weight.
BACKGROUND
[0002] The statements in this section merely provide background
information related to the present disclosure and may not
constitute prior art.
[0003] As the automotive industry continues to focus on reducing
the weight of vehicles to meet customer expectations on fuel
economy and CAFE (Corporate Average Fuel Economy) requirements,
interest in alternative materials including carbon fiber composite
applications has increased. In body-in-white structures, joining
methods have traditionally relied on resistance-spot welding (e.g.,
in steel structures).
[0004] In the case of aluminum intensive vehicles and other mixed
metal joining applications, self-piercing rivet technology
prevails. One advantage of self-piercing rivet technology is that
it is a high production volume assembly process. Self-piercing
rivet technology is compatible with adhesive and both methods can
be used together. The challenge often faced with self-piercing
rivet technology, however, is that the substrate material must be
ductile enough to form a "button", i.e., protrusion, which is the
result of creating the joint and the necessary deformation to
provide mechanical interlock. When composite parts do not have
sufficient ductility to form a button on the obverse side, fibers
may be exposed through cracks in this surface. Surface cracking and
fiber displacement are undesirable, as they may reduce the
durability of the joint and result in premature failure. With a
self-piercing rivet, fibers in the area where the rivet is inserted
may result in surface cracking or fiber displacement.
[0005] Composite materials, such as carbon fiber, glass fiber or
natural fiber composites, can be limited in application due to
challenges relating to joining parts together. Frequently, these
composites have limited ductility and are not well adapted to large
displacements and deformation required to join parts together with
self-piercing rivets. Other non-composite materials having higher
strength and light weight are also often brittle and challenging to
join using SPR technology.
[0006] The joining of advanced high strength and lightweight
materials, among other assembly issues, is addressed by the present
disclosure.
SUMMARY
[0007] In one form, an assembly is provided, which includes an
upper substrate, a lower substrate, and a self-piercing rivet. The
lower substrate defines a preformed interior cavity and a preformed
exterior profile adjacent the interior cavity to define a variable
thickness wall. The self-piercing rivet extends through the upper
substrate and into the preformed interior cavity of the lower
substrate. The preformed interior cavity of the lower substrate is
may or not be plastically deformed after installation of the
self-piercing rivet.
[0008] In one form, the lower substrate is an aluminum casting or
an aluminum extrusion. In another form, the lower substrate is a
composite material. The preformed interior cavity in one form
defines a circular trench having a raised central region, and in
another form, the preformed exterior profile defines a closed
cylinder. The preformed exterior profile may further define a
radiused area extending between a lower surface of the lower
substrate and the cylinder. Generally, the preformed interior
cavity is configured to direct flaring of the self-piercing
rivet.
[0009] In another form, a dimpled substrate for use in an assembly
having joined substrates is provided. The dimpled substrate defines
at least one preformed interior cavity and at least one preformed
exterior profile adjacent the interior cavity to define a variable
thickness wall. The preformed interior cavity is configured to
receive a fastening system that plastically deforms at least one of
the substrates during joining.
[0010] In still another form, an assembly is provided, which
includes an upper substrate, a lower substrate, and a plurality of
self-piercing rivets. The lower substrate defines a plurality of
preformed interior cavities and a corresponding plurality of
preformed exterior profiles adjacent the interior cavities to
define variable thickness walls therebetween. The plurality of
self-piercing rivets extend through the upper substrate and into
the preformed interior cavities of the lower substrate. The
preformed interior cavities are configured to direct flaring of the
self-piercing rivets.
[0011] Further areas of applicability will become apparent from the
description provided herein. It should be understood that the
description and specific examples are intended for purposes of
illustration only and are not intended to limit the scope of the
present disclosure.
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] The present disclosure will become more fully understood
from the detailed description and the accompanying drawings,
wherein:
[0013] FIG. 1 is a cross-sectional view of a joined assembly
constructed in accordance with the teachings of the present
disclosure;
[0014] FIG. 2 is a top perspective view of a lower substrate of the
joined assembly of FIG. 1 having a preformed interior cavity
according to the teachings of the present disclosure;
[0015] FIG. 3 is a bottom perspective view of the lower substrate
of FIG. 2;
[0016] FIG. 4 is a cross-sectional view of the lower substrate of
FIG. 2;
[0017] FIG. 5 is a cross-sectional view of a variant of a lower
substrate of a joined assembly constructed in accordance with the
teachings of the present disclosure;
[0018] and
[0019] FIG. 6 is a cross-sectional view of an upper substrate and a
lower substrate with a self-piercing rivet tool including a riveter
punch and a back-up die with a self-piercing rivet in position to
be driven into the upper and lower substrates.
[0020] Corresponding reference numerals indicate corresponding
parts throughout the several views of the drawings.
DETAILED DESCRIPTION
[0021] The following description is merely exemplary in nature and
is not intended to limit the present disclosure, application, or
uses.
[0022] Referring to FIG. 1, a joined composite or assembly 10
includes a lower substrate 12, an upper substrate 14, and at least
one self-piercing rivet 20 that secures the lower substrate 12 to
the upper substrate 14. While only one self-piercing rivet 20 is
shown, the joined composite or assembly 10 may include a plurality
of self-piercing rivets 20 spaced across the surface of the joined
composite or assembly 10. The lower substrate 12 may be a dimpled
substrate and includes at least one preformed exterior profile in
the form of a button shaped protrusion or "button" 18. The button
18 extends downwardly from a lower surface 22 of the lower
substrate 12 and is disposed in a predetermined location where a
corresponding self-piercing rivet 20 is planned to be inserted into
the lower substrate 12. The upper substrate 14 may be made of
steel, aluminum, a fiber reinforced composite material, or other
materials. The lower substrate 12 may be a cast part, a molded
part, or a 3D-printed part, among others. In various forms of the
present disclosure, the substrate 12 is an aluminum casting, an
aluminum extrusion, or a composite material.
[0023] Referring to FIGS. 2 and 3, the button 18 of the lower
substrate 12 is configured to be a closed cylinder which has a
peripheral wall 24 and a bottom wall 26. The peripheral wall 24 and
the bottom wall 26 jointly define a preformed exterior profile
having a preformed interior cavity 28. The preformed interior
cavity 28 is configured to receive a fastening system, such as the
self-piercing rivet 20, which plastically deforms at least one of
the lower and upper substrates 12, 14 during joining.
[0024] Referring to FIG. 4, the bottom wall 26 has a variable
thickness and has the largest thickness adjacent a central region,
thereby defining a raised central region 30. A circular or annular
trench 32 is defined between the raised central region 30 and the
sidewall 24 of the button 18 and surrounds the raised central
region 30. The button 18 has a substantially flat bottom surface 34
in one form of the present disclosure. The raised central region 30
has a top surface 36 that is lower than a lower surface 22 of the
lower substrate 12.
[0025] Referring to FIG. 5, a lower substrate 50 in accordance with
a variant of the present disclosure is structurally similar to the
lower substrate 12 of FIGS. 1 to 4 except for the configuration of
the button. More specifically, the lower substrate 50 includes a
button 52 defining a preformed internal cavity 54 and includes a
bottom wall 62. The bottom wall 62 has a variable thickness and has
the largest thickness adjacent a central region, thereby defining a
raised central region 64. An annular or circular trench 66 is
defined inside the preformed internal cavity 54 and surrounds the
raised central region 64. The raised central region 64 defines a
top surface 68 raised to a height above the lower surface 72 of the
lower substrate 50. The bottom surface 70 of bottom wall 70 of the
button 52 is substantially flat. The button 52 further includes a
radiused area 74 that joins the bottom surface 70 of the bottom
wall 70 to the lower surface 72 the lower substrate 50 where no
button is formed.
[0026] Referring to FIG. 6, to join the lower substrate 12 to the
upper substrate 14, the upper substrate 14 is placed over the lower
substrate 12 in a self-piercing rivet tool 80. The self-piercing
rivet tool 80 includes a riveter punch 82 and a back-up die 84. The
preformed interior cavity 28 of the button 18 of the lower
substrate 12 is closed by the upper substrate 14.
[0027] The self-piercing rivet 20 is placed inside the
self-piercing rivet tool 80 and immediately above the preformed
interior cavity 28 of the lower substrate 12. The self-piercing
rivet 20 has an insertion end 88 to pierce through the upper
substrate 14 and to be inserted into the preformed interior cavity
28 of the lower substrate 12 to engage the bottom wall 26 of the
button 18. It should be understood that the reference to a top side
is not limiting and that the lower and the upper substrates 12, 14
may be arranged in any orientation.
[0028] Referring back to FIG. 1, when the self-piercing rivet 20 is
completely inserted into the joined composite or assembly 10, the
insertion end 88 of the self-piercing rivet 20 is spread apart as
the self-piercing rivet 20 is driven through the upper substrate
14. The preformed interior cavity 28 is configured to direct
flaring of the self-piercing rivet 20. A portion of the upper
substrate 14 adjacent the self-piercing rivet 20 is plastically
deformed. Material from the upper substrate 14 may be deformed and
directed into the preformed interior cavity 28 to fill the
preformed interior cavity 28. Radially displaced material 92 fills
in between the side of the self-piercing rivet 20 and the button
18. Axially displaced material 94 fills in between the insertion
end 88 of the self-piercing rivet 20 and the bottom wall 26 of the
button 18 of the lower substrate 12.
[0029] The self-piercing rivet 20 penetrates the lower substrate 12
to create a mechanical interlock, thereby joining the lower
substrate 12 and the upper substrate 14 together. The preformed
interior cavity 28 of the lower substrate 12 may or may not be
plastically deformed after installation of the self-piercing rivet
20. The preformed button 18 and the preformed internal cavity 28
receive the displaced material 92, 94 and reduce the force exerted
on the lower substrate 12 in the area of the preformed button 18.
By preforming the button 18, any tendency for the button 18 to
crack or split is substantially reduced.
[0030] With the lower substrate 12 having a preformed exterior
profile, the lower substrate 12 may be made of a brittle material.
Therefore, a brittle material or a low-strain material may be
easily joined to another material by a self-piercing rivet.
[0031] The joined composite or assembly 10 constructed in
accordance with the teachings of the present application may be
used to form vehicle body and closure parts in automobiles or in
any applications which require joining of two or more layers of
materials.
[0032] It should be noted that the disclosure is not limited to the
embodiment described and illustrated as examples. A large variety
of modifications have been described and more are part of the
knowledge of the person skilled in the art. These and further
modifications as well as any replacement by technical equivalents
may be added to the description and figures, without leaving the
scope of the protection of the disclosure and of the present
patent.
* * * * *