U.S. patent application number 11/215197 was filed with the patent office on 2007-03-01 for method for blind rivet welding.
Invention is credited to Robin Stevenson, Pei-Chung Wang.
Application Number | 20070044292 11/215197 |
Document ID | / |
Family ID | 37802040 |
Filed Date | 2007-03-01 |
United States Patent
Application |
20070044292 |
Kind Code |
A1 |
Stevenson; Robin ; et
al. |
March 1, 2007 |
Method for blind rivet welding
Abstract
A blind rivet assembly is inserted through aligned holes
provided in a top member and bottom member. The blind rivet
includes a rivet head that abuts the top member and a hollow rivet
shank integral with the rivet head. A mandrel includes a mandrel
stem that extends thorough the hollow rivet and a mandrel head that
abuts the terminal end of the rivet shank. A tool holds the rivet
head in contact with the top member and forcibly withdraws the
mandrel in the direction to exit the aligned holes to thereby cause
the mandrel head of axially collapse and radially expand the
terminal end of the rivet shank into engagement with the bottom
member to thereby attach the top member and the bottom member
together. Weld current is then applied to the rivet head to thereby
weld the blind rivet in place.
Inventors: |
Stevenson; Robin;
(Bloomfield, MI) ; Wang; Pei-Chung; (Troy,
MI) |
Correspondence
Address: |
GENERAL MOTORS CORPORATION;LEGAL STAFF
MAIL CODE 482-C23-B21
P O BOX 300
DETROIT
MI
48265-3000
US
|
Family ID: |
37802040 |
Appl. No.: |
11/215197 |
Filed: |
August 30, 2005 |
Current U.S.
Class: |
29/524.1 ;
29/525.06 |
Current CPC
Class: |
B21J 15/10 20130101;
B23K 11/0066 20130101; B23K 11/34 20130101; B23K 11/004 20130101;
Y10T 29/49956 20150115; Y10T 29/49943 20150115; B21J 15/043
20130101 |
Class at
Publication: |
029/524.1 ;
029/525.06 |
International
Class: |
B21D 39/00 20060101
B21D039/00 |
Claims
1. A method of blind riveting together a top member and a bottom
member provided with aligned rivet holes therein, comprising the
steps of: inserting a blind rivet assembly through the aligned
rivet holes of the top and bottom members, said blind rivet
assembly including a blind rivet and a mandrel, the blind rivet
having a rivet head abutting the top member and a hollow shank
reaching through the aligned holes of the top and bottom members
and having a terminal end, the mandrel including a stem extending
through the hollow shank of the rivet and a mandrel head adjacent
the terminal end of the rivet shank, forcibly withdrawing the
mandrel in the direction to exit the aligned holes to thereby cause
the mandrel head to axially collapse and radially expand the hollow
shank of the blind rivet into engagement with the bottom member to
thereby attach the top member and the bottom member; and applying
weld current to the rivet head to weld the blind rivet in
place.
2. The method of claim 1 comprising the further step of fracturing
the mandrel stem from the mandrel head after the mandrel head has
axially collapsed and radially expanded the hollow shank of the
blind rivet
3. The method of claim 2 further comprising the step of fracturing
the mandrel stem after applying the weld current.
4. The method of claim 2 further comprising the step of fracturing
the mandrel stem prior to applying the weld current.
5. The method of claim 2 further comprising the step of fracturing
the mandrel stem during the application of weld current.
6. The method of claim 1 in which an installation tool for
installing the blind rivet assembly includes an anvil that seats on
the rivet head and has a welder cable connected thereto so that the
anvil functions as an electrode to apply weld current to the rivet
head.
7. The method of claim 6 in which the installation tool includes an
electrode that is connected to a welder cable and seats against the
top member at a distance from the blind rivet so that weld current
is conducted through the blind rivet and through the top
member.
8. A method of blind riveting together a top member and a bottom
member provided with aligned rivet holes therein, comprising the
steps of: inserting a blind rivet assembly through the aligned
rivet holes of the top and bottom members, said blind rivet
assembly including a blind rivet and a mandrel, the blind rivet
having a rivet head abutting the top member and a hollow shank
reaching through the aligned holes of the top and bottom members
and having a terminal end, the mandrel including a stem extending
through the hollow shank of the rivet and a mandrel head adjacent
the terminal end of the rivet shank, applying an installation tool
including an anvil seated on the rivet head and jaws for gripping
and forcibly withdrawing the mandrel to thereby cause the mandrel
head to axially collapse and radially expand the hollow shank of
the blind rivet into engagement with the bottom member to thereby
attach the top member and the bottom member; applying an electrode
to one of the top and bottom members at a distance from the blind
rivet, and conducting weld current between the anvil and electrode
so that the blind rivet is melted and metallurgically bonded with
at least the top member to thereby weld the blind rivet in
place.
9. The method of claim 8 in which the blind rivet is welded to both
the top member and the bottom member.
10. The method of claim 8 in which the mandrel is welded to the
blind rivet.
11. The method of claim 8 in which the electrode is a part of the
installation tool so that upon the application of the installation
tool to seat the anvil upon the rivet head, the electrode is
simultaneously placed against the top member.
12. The method of claim 8 in which at least a portion the mandrel
stem is fractured from the mandrel head.
13. A method of blind riveting together a top member and a bottom
member provided with aligned rivet holes therein, comprising the
steps of: inserting a blind rivet assembly through the aligned
rivet holes of the top and bottom members, said blind rivet
assembly including a blind rivet and a mandrel, the blind rivet
having a rivet head abutting the top member and a hollow shank
reaching through the aligned holes of the top and bottom members
and having a terminal end, the mandrel including a stem extending
through the hollow shank of the rivet and a mandrel head adjacent
the terminal end of the rivet shank, applying an installation tool
including an anvil seated on the rivet head and jaws for gripping
and forcibly withdrawing the mandrel in the direction to exit the
aligned holes to thereby cause the mandrel head to axially collapse
and radially expand the hollow shank of the blind rivet into
engagement with the bottom member to thereby attach the top member
and the bottom member, said installation tool further including an
electrode that seats against the upper member at a distance from
the rivet head; and conducting weld current between the anvil and
electrode so that the blind rivet is melted and metallurgically
bonded with the top member and the bottom member so that the weld
assists the blind rivet in attaching the top and bottom members
together.
14. The method of claim 13 in which the installation tool also
causes a fracture of at least a portion of the mandrel stem from
the mandrel head.
15. The method claim 14 in which the fracture of the mandrel stem
occurs one of either before, during or after the application of the
weld current.
16. The method of claim 13 in which the weld current causes the
mandrel head to become welded to the blind rivet.
17. The method of claim 13 in which the weld current causes the
rivet shank to become welded to at least one of the first member
and second member.
18. The method of claim 13 in which the weld current welds the
rivet shank to the first member and the second member.
19. The method of claim 13 in which the anvil of the installation
tool is constructed of a copper-based alloy.
Description
FIELD OF THE INVENTION
[0001] The present invention relates to an improved method for
blind riveting together a pair of members.
BACKGROUND OF THE INVENTION
[0002] It is known to attach together a pair of members using a
blind rivet assembly. The use of a blind rivet to attach members
together is particularly useful in the assembly or repair of
vehicle bodies or other applications in which access can be
obtained to only one side of one of the members (a top member),
with the other member (a bottom member) being hidden and
inaccessible below the top member.
[0003] It would be desirable to provide improvements in the blind
rivet method of attaching members together. For example,
improvements to make such attachments stronger and more vibration
proof would be desirable.
SUMMARY OF THE INVENTION
[0004] In an improved method of blind rivet fastening aligned holes
are provided in the top and bottom members. A blind rivet assembly
is inserted through the aligned holes. The blind rivet includes a
rivet head that abuts the top member and a hollow rivet shank that
is integral with the rivet head and reaches through and beyond the
aligned holes and has a terminal end. The blind rivet assembly also
includes a mandrel, the mandrel having a mandrel stem that extends
thorough the hollow rivet and includes a mandrel head that abuts
the terminal end of the rivet shank. A tool holds the rivet head in
contact with the top member and forcibly withdraws the mandrel to
thereby cause the mandrel head to axially collapse and radially
expand the terminal end of the rivet shank into engagement with the
bottom member to thereby attach the top member and the bottom
member together. Weld current is then applied to the rivet head to
thereby weld the blind rivet in place.
[0005] Further areas of applicability of the present invention will
become apparent from the detailed description provided hereinafter.
It should be understood that the detailed description and specific
examples, while indicating exemplary embodiments of the invention,
are intended for purposes of illustration only and are not intended
to limit the scope of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0006] The present invention will become more fully understood from
the detailed description and the accompanying drawings,
wherein:
[0007] FIG. 1 is a section view through a top member and a bottom
member that are to be attached together and showing a blind rivet
assembly seated in aligned holes in the members;
[0008] FIG. 2 is a view similar to FIG. 1 but showing a tool
positioned over the blind rivet assembly;
[0009] FIG. 3 show that the jaws of the tool have gripped the
mandrel of the blind rivet assembly;
[0010] FIG. 4 shows that the jaws of the tool have been actuated to
withdraw the mandrel and thereby cause the head of the mandrel to
expand the rivet shank of the blind rivet into engagement with the
bottom member;
[0011] FIG. 5 shows that the mandrel has been fractured;
[0012] and FIG. 6 shows that weld current has been applied through
the tool to weld the blind rivet assembly in place.
DETAILED DESCRIPTION OF THE EXEMPLARY EMBODIMENTS
[0013] Referring to FIG. 1, a top member 10 is a sheet metal panel
and a bottom member 12 is a metal tube. The top member and the
bottom member are to be attached together.
[0014] A hole 14 is drilled, pierced, or otherwise provided through
the top member 10 and an aligned hole 16 is provided in the bottom
member 12.
[0015] A blind rivet assembly 18 is inserted through the aligned
holes 14 and 16. The blind rivet assembly 18 includes a blind rivet
22 and a mandrel 24.
[0016] The blind rivet 22 has a rivet head 26 and a hollow rivet
shank 28 that are integrally formed in one piece. The rivet head 26
rests on the top face 30 of the top member 10. The hollow rivet
shank 28 extends through the aligned holes 14 and 16 and is
somewhat longer than the combined thickness of the top and member
members 10 and 12 and has terminal end 32 that ends somewhat beyond
the bottom face 34 of the bottom member 12.
[0017] The mandrel 24 includes a stem 38 that extends through the
blind rivet 22 and has an enlarged mandrel head 40 at its terminal
end. As seen in FIG. 1, the mandrel 24 is longer than the length of
the blind rivet 22 so that the stem 38 extends well above the rivet
head 26 of the blind rivet 22. The mandrel head 40 is larger than
the inner diameter of the hollow rivet shank 28 of the blind rivet
22, but smaller than the diameter of the aligned holes 14 and 16 so
that the blind rivet assembly 18 can be inserted through the
aligned holes 14 and 16. The mandrel stem 38 has a weakness,
particularly a fracture notch at 42 to define a fracture region in
the stem 38, as will be discussed hereinafter.
[0018] Referring to FIG. 2, a blind rivet installation tool,
generally indicated at 48, is used to install the blind rivet
assembly 18. The tool includes an anvil 50 in the form of a hollow
sleeve and having an anvil end 52 that is pressed against the rivet
head 26. A plurality of opposed jaws, of which jaws 54 and 56 are
shown in the drawings, are situated within the anvil head 50 and
operated by an actuator and collet mechanism, not shown, by which
the jaws cooperate to grip the mandrel stem 38 and forcibly
withdraw the mandrel stem 38 in the upward direction as viewed in
the drawing Figures, as will be discussed hereinafter.
[0019] In FIG. 2, the tool is shown with the anvil 50 pressed
against the rivet head 26 and the jaws 54 and 56 in open positions
surrounding the mandrel stem 38.
[0020] FIGS. 3, 4 and 5 show the progressive actuation of the blind
rivet installation tool 48 to install the blind rivet assembly 18.
In FIG. 3, the jaws 54 and 56 have been partially withdrawn in the
upward direction and moved together into gripping relationship with
the mandrel stem 38. It will be appreciated that the jaws 54 and 56
are shown with teeth that assure effective gripping of the mandrel
stem 38. The mandrel stem 38 may also be provided with grooves, not
shown, to further promote gripping by the jaws 54 and 56.
[0021] In FIG. 4, the jaws 54 and 56 have been forcibly withdrawn
causing the mandrel stem 38 to have been drawn upwardly so that the
mandrel head 40 has contacted the terminal end 32 of the rivet
shank 28 and worked to axially collapse and radially expand the
rivet shank 28 to form an expanded head 60 that engages with the
underside 34 of the lower member 12. Thus, the top member 10 and
the bottom member 12 are tightly captured between the rivet head 22
and the expanded head 60 of the rivet shank 28, thereby fastening
together the top member 10 and the bottom member 12.
[0022] In FIG. 5, the jaws 54 and 56 have been further withdrawn so
that the mandrel stem 38 has fractured, as facilitated by the
fracture notch 42.
[0023] Referring to FIG. 6, it is seen that the anvil 50 of the
installation tool has an electrical cable 70 attached thereto. The
cable 70 connects to a resistance welder 72 so that the anvil 50
serves as an electrode. An electrode 74 is placed against the upper
member 10 a short distance from the rivet head 22. Cable 76
connects electrode 74 to the welder 72.
[0024] FIG. 6 shows that weld current has been applied to the anvil
50 and to the electrode 74 so that the rivet shank 28 of the blind
rivet 22 has become welded by the heat resulting from the
conduction of the weld current through the rivet assembly 18 and
the top member 10. Accordingly, the blind rivet 22 is held in
place, and the upper member 10 and the lower member 12 are
connected together, by both the welded connection and by the
mechanical clamping of the top and bottom member between the rivet
head 26 and the expanded head 60 of the hollow rivet shank 28.
[0025] The anvil 50 and the electrode 74 may be a copper material
in order to promote the welding process. A person of ordinary skill
in the art will recognize that the extent and quality of the weld
will be determined by control of the customary welding variables
such as the relative thickness and materials of the top and bottom
member 10, the size and materials of the blind rivet assembly 18,
the distance between the electrodes, the weld current, the duration
of the weld current, and the forces with which the electrodes are
held against the rivet head 26 and the top member 10 of the weld.
Accordingly, in some cases, the weld current may develop material
melting and metallurgical bonding between the mandrel 24 and the
rivet 22, as well as melting and bonding between the rivet and the
top and bottom members 10 and 12.
[0026] The forgoing description of the invention is merely
exemplary in nature and, thus, variations thereof are intended to
be within the scope of the invention. For example, the fracture of
the mandrel, as shown in FIG. 6, may occur either before, during,
or after the application of the weld current. Furthermore, its is
known that blind rivet assemblies are available in many shapes and
designs, and the present invention is not limited to the particular
style of blind rivet assembly shown in the drawings. In addition,
the electrode 74 may be mounted on a common tool support mechanism,
not shown, with the installation tool 48 and anvil 50 so that the
electrode 74 is forced against the top member 10 simultaneous with
the placement of the anvil 50 against the blind rivet head 26.
Alternatively, the electrode 74 may be separately moved into
contact with the top member 10 by its own support mechanism, not
shown. In addition, in that circumstance where the bottom member 12
is accessible, it may be desirable to place the electrode 74
against the bottom member 12 instead of against the top member
10.
* * * * *