U.S. patent application number 12/746948 was filed with the patent office on 2010-11-11 for resistive implant welding of thermoplastic materials with butt joints.
Invention is credited to Bradford D. Armstrong, Steven Grgac.
Application Number | 20100285261 12/746948 |
Document ID | / |
Family ID | 40755210 |
Filed Date | 2010-11-11 |
United States Patent
Application |
20100285261 |
Kind Code |
A1 |
Grgac; Steven ; et
al. |
November 11, 2010 |
Resistive Implant Welding of Thermoplastic Materials with Butt
Joints
Abstract
A method for forming butt joints between thermoplastic members
by resistive implant welding. A tongue is formed on one member to
be joined and a complementary groove is formed in the other member.
A resistive implant is placed between the tongue and the groove
which are then pressed together by an applied pressure. An electric
current is run through the resistive implant to melt a portion of
the thermoplastic material of both the tongue and groove, and the
melted plastic intermingles through the implant. When the electric
current is removed, the plastic cools, forming a weld.
Inventors: |
Grgac; Steven; (Mississauga,
CA) ; Armstrong; Bradford D.; (Barrie, CA) |
Correspondence
Address: |
MAGNA INTERNATIONAL, INC.
337 MAGNA DRIVE
AURORA
ON
L4G-7K1
CA
|
Family ID: |
40755210 |
Appl. No.: |
12/746948 |
Filed: |
December 11, 2008 |
PCT Filed: |
December 11, 2008 |
PCT NO: |
PCT/CA08/02141 |
371 Date: |
July 21, 2010 |
Related U.S. Patent Documents
|
|
|
|
|
|
Application
Number |
Filing Date |
Patent Number |
|
|
61007239 |
Dec 11, 2007 |
|
|
|
Current U.S.
Class: |
428/57 ;
156/273.7 |
Current CPC
Class: |
B29C 66/7212 20130101;
B29K 2105/06 20130101; B29C 66/1248 20130101; Y10T 428/19 20150115;
B29K 2023/10 20130101; B29K 2309/08 20130101; B29K 2023/12
20130101; B29K 2023/12 20130101; B29C 66/71 20130101; B29K 2309/08
20130101; B29C 66/8322 20130101; B29C 66/71 20130101; B29C 66/71
20130101; B29C 66/7212 20130101; B29C 66/73921 20130101; B29L
2031/30 20130101; B29C 65/344 20130101; B29C 66/12463 20130101;
B60R 13/00 20130101; B29C 66/12449 20130101; B29K 2101/12 20130101;
B29C 66/43 20130101; B29C 66/54 20130101; B29C 66/721 20130101;
B29C 65/3476 20130101; B29C 66/12469 20130101 |
Class at
Publication: |
428/57 ;
156/273.7 |
International
Class: |
B29C 65/30 20060101
B29C065/30; B32B 3/02 20060101 B32B003/02 |
Claims
1. An assembly connected together through the use of resistive
implant welding, comprising: a first panel; a groove formed in a
portion of said first panel; a second panel; a tongue portion
formed on a portion of said first panel, said tongue portion
complementary in shape in relation to said groove; and a resistive
implant operable for being substantially disposed within said
groove such that when said tongue portion is positioned in said
groove, said resistive implant is positioned between said tongue
portion and said groove, and a current is applied to said resistive
implant, generating heat to join said tongue portion and said
groove, thereby joining said first panel to said second panel.
2. The assembly connected together through the use of resistive
implant welding of claim 1, further comprising: a notch extending
along and formed on a portion of said first panel, said notch being
substantially parallel to said groove formed in a portion of said
first panel; and a flange extending along said second panel, said
flange being complementary in shape to said notch such that when
said first panel is joined to said second panel, said flange will
be engaged with said notch.
3. The assembly connected together through the use of resistive
implant welding of claim 1, further comprising: at least one
support member formed on a portion of said second panel; and at
least one slot formed between said at least one support member and
said tongue portion, said at least one slot abutting a rear outer
surface of said groove when said tongue portion is disposed in said
groove.
4. The assembly connected together through the use of resistive
implant welding of claim 3, wherein said at least one support
member is operable for preventing a bending moment about said
groove and said tongue when said tongue is disposed in said
groove.
5. The assembly connected together through the use of resistive
implant welding of claim 1, wherein pressure is applied to said
first panel and said second panel as said resistive implant is
heated to facilitate said first panel being joined with said second
panel.
6. The assembly connected together through the use of resistive
implant welding of claim 1, said resistive implant further
comprising a wire mesh.
7. The assembly connected together through the use of resistive
implant welding of claim 6, said wire mesh further comprising wires
of substantially 0.009 inches in diameter.
8. The assembly connected together through the use of resistive
implant welding of claim 6, said wire mesh further comprising a
plain weave of approximately sixteen wires per inch.
9. The assembly connected together through the use of resistive
implant welding of claim 1, wherein as a current is applied to said
resistive implant, a portion of said groove will melt and a portion
of said tongue portion will melt, and when said groove and said
tongue portion are allowed to cool, said tongue portion will be
joined to said groove.
10. An assembly connected together through the use of resistive
implant welding comprising: a first panel; a groove formed in a
portion of said first panel; a notch formed in said first panel,
said notch extending along said first panel and is substantially
parallel to said groove; a second panel; a tongue portion formed in
a portion of said second panel, said tongue portion complementary
in shape to, and operable for being positioned in, said groove; a
flange formed on said second panel and complementary in shape to
said notch, said flange being operable to be engaged with said
notch when said tongue portion is positioned in said groove; and a
resistive implant operable for being positioned in said groove and
in contact with said tongue portion when said tongue portion is
positioned in said groove such that when a current is applied to
said resistive implant, heat is generated, causing a portion of
said tongue portion to melt, and a portion of said groove to melt,
and a melted portion of said tongue portion will join a melted
portion of said tongue portion after said tongue portion and said
groove are allowed to cool.
11. The assembly connected together through the use of resistive
implant welding of claim 10, further comprising: at least one
support member formed on a portion of and extending away from said
second panel; and at least one slot formed between said at least
one support member and said tongue portion, said at least one slot
operable for receiving an outer surface of said groove.
12. The assembly connected together through the use of resistive
implant welding of claim 11, wherein said at least one support
member is operable for preventing a bending moment about said
groove and said tongue when said tongue is disposed in said
groove.
13. The assembly connected together through the use of resistive
implant welding of claim 10, wherein as said current is applied to
said resistive implant, a pressure is applied to said first panel
and said second panel, further joining said first panel to said
second panel.
14. The assembly connected together through the use of resistive
implant welding of claim 10, said resistive implant further
comprising a wire mesh configured as a plain weave of approximately
sixteen wires per inch.
15. The assembly connected together through the use of resistive
implant welding of claim 14 said wire mesh further comprising wires
of substantially 0.009 inches in diameter.
16. The assembly connected together through the use of resistive
implant welding of claim 10, wherein as a current is applied to
said resistive implant, said melted portion of said tongue portion
and said melted portion of said groove will interface through said
resistive implant.
17. A method of forming a welded butt joint between first and
second thermoplastic components, the method comprising the steps
of: providing a first thermoplastic component; providing a second
thermoplastic component to be joined with said first thermoplastic
component; providing a resistive implant operable for facilitating
the joining of said first thermoplastic component to said second
thermoplastic component; forming a groove along an edge of said
first thermoplastic component; forming a tongue along an edge of
said second thermoplastic component; inserting said tongue into
said groove with said resistive implant located therebetween;
applying pressure to said first thermoplastic component and said
second thermoplastic component to urge said tongue into said groove
while applying an electric current to said resistive implant for a
pre-selected time to melt a portion of said thermoplastic material
of said tongue and said groove; and removing the electric current
and allowing the melted thermoplastic material to resolidify while
maintaining the pressure to form a welded butt joint between said
first thermoplastic component and said second thermoplastic
component.
18. The method of forming a welded butt joint between first and
second thermoplastic components of claim 17, further comprising the
steps of: forming a notch disposed along said first thermoplastic
component, such that said notch is substantially parallel to said
groove formed in said first thermoplastic component; forming a
flange on a portion of said second thermoplastic component; and
positioning said flange adjacent to said notch when said tongue is
disposed in said groove.
19. The method of forming a welded butt joint between first and
second thermoplastic components of claim 17, further comprising the
steps of: forming at least one support member on said second
thermoplastic component in proximity to said tongue; forming at
least one slot between a portion of said at least one support
member and said tongue; and abutting said at least one slot to a
rear outer surface of said groove when said tongue is disposed in
said groove.
20. The method of forming a welded butt joint between first and
second thermoplastic components of claim 17, further comprising the
steps of said at least one support member preventing a bending
moment about said groove and said tongue when said tongue is
disposed in said groove.
21. The method of forming a welded butt joint between first and
second thermoplastic components of claim 17, further comprising the
steps of forming said resistive implant from a wire mesh.
22. The method of forming a welded butt joint between first and
second thermoplastic components of claim 21, further comprising the
steps of forming said wire mesh from wires of substantially 0.009
inches in diameter.
23. The method of forming a welded butt joint between first and
second thermoplastic components of claim 21, further comprising the
steps of forming said wire mesh from a plain weave of sixteen wires
per inch.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a PCT International Application of U.S.
Patent Application No. 61/007,239 filed on Dec. 11, 2007. The
disclosure of the above application is incorporated herein by
reference. This application claims the benefit of U.S. Provisional
Application No. 61/007,239, filed Dec. 11, 2007.
FIELD OF THE INVENTION
[0002] The present invention relates to resistive implant welding
of thermoplastic components. More specifically, the present
invention relates to a method and system for forming butt joints of
thermoplastic components using resistive implant welding.
BACKGROUND OF THE INVENTION
[0003] A need exists to join thermoplastic components, such as
those formed from glass fiber reinforced polypropylene or the like,
to other plastic components formed of similar materials. To date,
such joining has been achieved via adhesives, mechanical fasteners,
laser welding and/or sonic or vibration welding.
[0004] More recently, lap welds have been formed to join
thermoplastic components using resistive implant welding
techniques. In general, the technology of forming lap welds with
resistive implant welding is described in, "Resistive Implant
Welding of Glass Fiber Reinforced Polypropylene Compounds", by
Bates, Tan, Zak and Mah, published by the Society of Automotive
Engineers, SAE Technical Papers, document number 2006-01-0332 and
the contents of this paper are included herein, in its entirety, by
reference.
[0005] While resistive implant welding is proving to be a promising
technique for forming lap welds between thermoplastic materials, to
date resistive implant welding techniques have only been able to
form lap welds which limits the use of these techniques.
SUMMARY OF THE INVENTION
[0006] It is an object of the present invention to provide a novel
method and system for using resistive implant welding to form butt
joints of components formed of thermoplastic materials which
obviates or mitigates at least one disadvantage of the prior
art.
[0007] According to a first aspect of the present invention, there
is provided a method of forming a welded butt joint between first
and second thermoplastic components, the method comprising the
steps of: forming a tongue along an edge of a first thermoplastic
component to be joined; forming a groove along an edge of a second
thermoplastic component to be joined; inserting the tongue into the
groove with a resistive implant located therebetween; applying
pressure to the first thermoplastic component and the second
thermoplastic component to urge the tongue into the groove while
applying an electric current to the resistive implant for a
pre-selected time to melt a portion of the thermoplastic material
of the tongue and groove; and removing the electric current and
allowing the melted thermoplastic material to resolidify while
maintaining the pressure to form a welded butt joint between the
first and second thermoplastic components.
[0008] The present invention provides a method for forming butt
joints between thermoplastic members by resistive implant welding.
A tongue if formed on one member to be joined and a complementary
groove is formed in the other member. A resistive implant is placed
between the tongue and the groove which are then pressed together
by an applied pressure. An electric current is run through the
resistive implant to melt a portion of the thermoplastic material
of the tongue and groove and the melted plastic intermingles,
through the implant. When the electric current is removed, the
plastic cools, forming a weld.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] Preferred embodiments of the present invention will now be
described, by way of example only, with reference to the attached
Figures, wherein:
[0010] FIG. 1 shows a first exploded view of the rear sides of a
pair of thermoplastic components to be joined, according to the
present invention;
[0011] FIG. 2 shows a second exploded view, similar to that of FIG.
1, wherein a resistive implant has been positioned between a pair
of thermoplastic components to be joined, according to the present
invention;
[0012] FIG. 3 shows a sectional side view of the components shown
in FIG. 2; and
[0013] FIG. 4 shows sectional side view of the component of FIG. 2,
where the pair of thermoplastic components are positioned relative
to one another before the weld has been formed.
DETAILED DESCRIPTION OF THE INVENTION
[0014] As used herein, the term "plastic" is intended to comprise
thermoplastic materials in general and such thermoplastic materials
can include added materials, such as glass fibers, to alter their
mechanical properties. While some of the following discussion makes
specific reference to glass fiber reinforced polypropylene
plastics, the present invention is not limited to use with this
particular reinforced thermoplastic material.
[0015] As discussed above, resistive implant welding is known. In
general, the technology of resistive implant welding is described
in, "Resistive Implant Welding of Glass Fiber Reinforced
Polypropylene Compounds", by Bates, Tan, Zak and Mah, published by
the Society of Automotive Engineers, SAE Technical Papers, document
number 2006-01-0332 and the contents of this paper are included
herein, in its entirety, by reference.
[0016] However, existing resistive implant welding is used to
connect plastic components via lap joints. In many circumstances,
it is desired to have components joined by a butt joint. In
particular, as lap joints result in joints with changing profiles,
butt joints would be preferred for joints on cosmetically
significant thermoplastic components, such as exterior body panels
on a vehicle.
[0017] To address this issue, the present inventors have developed
structures and methods for joining two or more panels of
thermoplastic materials via butt joints.
[0018] Specifically, FIG. 1 shows edge portions of a first panel 20
and a second panel 24, each of which is formed of a thermoplastic
material, which are to be joined by a butt joint.
[0019] Referring to the Figures generally, the first panel 20
includes a groove 28 along the rear face of the first panel 20 at
the edge to be joined. The first panel 20 also includes a small
notch 32 along the front face of panel 20 adjacent the edge to be
joined.
[0020] As is also shown, the second panel 24 includes a tongue 36,
which is complementary in shape to the groove 28. The tongue 36
runs along the rear face of second panel 24 at the edge to be
joined. The second panel also includes a flange 40 which is
complementary in shape to the notch 32, and the flange 40 extends
along the edge of second panel 24.
[0021] Second panel 24 further includes a series of support members
44, which extend at intervals along the edge of second panel 24 to
be joined. Each of the support members 44 extend perpendicularly
from the rear side of the second panel 24, and each of the support
members 44 also include a slot 48 which abuts the rear outer
surface of groove 28.
[0022] Each of the first panel 20 and second panel 24 may be formed
in any appropriate manner, such as by injection molding, which can
be used to form the panels 20 and 24 in the desired manner with the
above-described structures, including groove 28, notch 32, tongue
36, flange 40 and support members 44.
[0023] When it is desired to join first panel 20 and second panel
24 with a butt weld, a resistive implant 60 is placed between
tongue 36 and groove 28, as shown in FIGS. 2 and 3. In a presently
preferred embodiment of the invention, resistive implant 60 is a
stainless steel mesh with wires of 0.009 inches diameter woven in a
plain weave of sixteen wires to the inch. However, as will be
apparent to those of skill in the art, the present invention is not
limited to this type or configuration of resistive implant, and any
suitable resistive element, as will occur to those of skill in the
art, may be employed.
[0024] When resistive element 60 is properly placed, tongue 36 of
second panel 24 is inserted into groove 28 of first panel 20, as
shown in FIG. 4. The dimensions of the groove 28 and tongue 36 are
selected such that, when the resistive implant 60 is in place, a
substantially tight fit is obtained between the tongue 36 and
groove 28 to avoid any gaps, voids, or other empty volumes, except
any such volumes resulting from the structure of resistive implant
60, such as the gaps in the mesh if a resistive implant with a mesh
structure is employed.
[0025] Pressure is then applied, as indicated by arrows 64 and 68
in FIG. 4, to the interface between tongue 36 and groove 28. An
electric current is then passed through resistive implant 60
resulting in the heating of the interface between the groove 28 and
the tongue 36, melting the thermoplastic material. The melted
thermoplastic material of the groove 28 and the melted
thermoplastic material of the tongue 36 intermingle through the
mesh of the resistive implant 60 because of the pressure applied to
the first panel 20 and the second panel 24.
[0026] After a pre-selected time, the electric current is removed
from the resistive implant 60, the joint formed between the groove
28 and the tongue 36 is allowed to cool, and the pressure applied
to first panel 20 and second panel 24 is then removed. When
sufficiently cooled, the joint between the panels 20 and 24 is
complete.
[0027] Notch 32 and flange 40 serve to provide a smooth surface to
the weld on the front face of panels 20 and 24, and prevent any
over-engagement of panels 20 and 24 during the welding operation.
Further, the notch 32 and flange 40 cooperate with the support
members 44 to prevent any bending moment about the interface
between the groove 28 and the tongue 36 during the welding
operation.
[0028] As should be apparent to those of skill in the art, while it
is presently preferred that support members 44 be integrally formed
on at least the second panel 24, it is also contemplated that
support members 44 may be omitted, and support instead may be
provided by a die or other forming member which is placed adjacent
the rear of the groove 28 during the welding operation.
[0029] The present invention provides a method for forming butt
joints between thermoplastic members by resistive implant welding.
A tongue is formed on one member to be joined and a complementary
groove is formed in the other member. A resistive implant is placed
between the tongue and the groove which are then pressed together
by an applied pressure. An electric current is run through the
resistive implant to melt a portion of the thermoplastic material
of the tongue and groove; the melted plastic of the tongue and
groove intermingles through the implant. When the electric current
is removed, the plastic cools, forming a weld.
[0030] The above-described embodiments of the invention are
intended to be examples of the present invention and alterations
and modifications may be effected thereto, by those of skill in the
art, without departing from the scope of the invention which is
defined solely by the claims appended hereto.
* * * * *