U.S. patent application number 11/397270 was filed with the patent office on 2006-08-17 for automotive control module housing.
This patent application is currently assigned to Siemens VDO Automotive Corporation. Invention is credited to Michael Thorum.
Application Number | 20060181859 11/397270 |
Document ID | / |
Family ID | 30771106 |
Filed Date | 2006-08-17 |
United States Patent
Application |
20060181859 |
Kind Code |
A1 |
Thorum; Michael |
August 17, 2006 |
Automotive control module housing
Abstract
An automotive control module includes a plastic housing with a
snap-fit metal cover. A printed circuit board is positioned within
a cavity formed in the housing, and is attached to the housing with
a plurality of fasteners. Resilient tabs are formed on side walls
of the housing and grip a cover plate surface to define a snap-fit
attachment. Once the cover is attached to the plastic housing, the
printed circuit board is enclosed within the cavity between the
cover and the housing. The cover includes a plurality of heat
transfer fins and/or stamped indentations that form surfaces that
are positioned in close proximity to the printed circuit board. The
cover utilizes these fins and surfaces to form a heat sink for
cooling electronics mounted to the printed circuit board.
Inventors: |
Thorum; Michael; (Lake
Orion, MI) |
Correspondence
Address: |
SIEMENS CORPORATION;INTELLECTUAL PROPERTY DEPARTMENT
170 WOOD AVENUE SOUTH
ISELIN
NJ
08830
US
|
Assignee: |
Siemens VDO Automotive
Corporation
Auburn Hills
MI
|
Family ID: |
30771106 |
Appl. No.: |
11/397270 |
Filed: |
April 4, 2006 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
10990643 |
Nov 17, 2004 |
7050305 |
|
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11397270 |
Apr 4, 2006 |
|
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10610610 |
Jul 1, 2003 |
6881077 |
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10990643 |
Nov 17, 2004 |
|
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60397696 |
Jul 22, 2002 |
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Current U.S.
Class: |
361/719 |
Current CPC
Class: |
H05K 5/0013 20130101;
H05K 5/0052 20130101 |
Class at
Publication: |
361/719 |
International
Class: |
H05K 7/20 20060101
H05K007/20 |
Claims
1. An automotive electronic control module assembly comprising: a
housing defining an inner cavity; a printed circuit board
positioned within said inner cavity and mounted to said housing; a
cover plate positioned over said inner cavity to enclose said
printed circuit board within said housing; a plurality of resilient
members formed on said housing; and a retaining surface formed on
said cover plate wherein said plurality of resilient members engage
said retaining surface to securely attach said cover plate to said
housing.
2. The assembly as set forth in claim 1 wherein said cover plate is
positioned in an overlapping non-contact relationship with said
printed circuit board and is spaced apart from said printed circuit
board by a gap to form a heat sink.
3. The assembly as set forth in claim 2 wherein said cover plate is
comprised of a generally flat sheet portion having an upper surface
and a lower surface and includes at least one stamped indentation
defining an indentation bottom surface that is non-coplanar with
said upper and lower surfaces of said flat sheet portion.
4. The assembly as set forth in claim 3 wherein said gap has a
predefined minimum gap height of approximately 0.3 millimeters
between said indentation bottom surface and said printed circuit
board.
5. The assembly as set forth in claim 2 wherein said housing is
comprised of a plastic material and said cover plate is comprised
of a metallic material.
6. The assembly as set forth in claim 5 wherein said metallic
material comprises aluminum.
7. The assembly as set forth in claim 2 wherein said cover plate is
comprised of a base portion with a plurality of fins extending
outwardly from said base portion and away from said printed circuit
board.
8. The assembly as set forth in claim 1 wherein said cover plate
includes an upper portion and an indentation portion forming a heat
sink wherein said indentation portion comprises a non-contact
surface that is spaced apart from said printed circuit board to
form a gap between said non-contact surface and said printed
circuit board.
9. The assembly as set forth in claim 8 wherein said upper portion
includes a generally flat upper surface and said indentation
portion includes a generally flat indentation surface that is
non-coplanar to said flat upper surface.
10. The assembly as set forth in claim 1 wherein said plurality of
resilient members each comprise a resilient tab having a
transversely extending distal tip facing inwardly toward a center
of said inner cavity.
11. The assembly as set forth in claim 1 wherein said housing
includes a connector portion having structure for attachment to a
vehicle wiring harness.
12. The assembly as set forth in claim 1 wherein the automotive
electronic control module assembly generates a vehicle control
signal to control a vehicle powertrain system.
13. A method for assembling an automotive electronic control module
comprising the steps of: a) mounting a printed circuit board within
a cavity formed within a housing; and b) enclosing the printed
circuit board within the cavity by snapping a cover plate into
gripping engagement with the housing to form a secure snap-fit
attachment between the housing and the cover plate.
14. The method set forth in claim 13 including unsnapping the cover
plate from the housing when necessary to perform service
operations.
15. The method set forth in claim 14 wherein step (b) further
includes forming the cover plate from aluminum to include a body
portion with at least one indentation, and positioning the at least
one indentation closer to the printed circuit board than the body
portion to form a heat sink that facilitates heat transfer from the
printed circuit board to the cover plate.
16. The method as set forth in claim 15 including spacing the at
least one indentation apart from the printed circuit board to form
a gap.
17. The method as set forth in claim 14 wherein step (b) further
includes forming a plurality of fins on an upper surface of the
cover plate with the plurality of fins extending outwardly from the
upper surface and away from the printed circuit board to facilitate
heat transfer from the printed circuit board to the cover
plate.
18. The method as set forth in claim 13 including forming a
connector portion in the housing for connection to a vehicle wire
harness.
19. The method as set forth in claim 13 wherein the printed circuit
board and associated control electronics comprise a control module
and including generating a vehicle control signal from the control
module to control a vehicle powertrain system.
20. The method as set forth in claim 13 including forming the
housing from plastic and forming the cover plate from metal.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] The application is a continuation of U.S. patent application
Ser. No. 10/990,643, filed Nov. 17, 2004, which is a divisional of
Ser. No. 10/610,610 filed on Jul. 1, 2003, which claims priority to
U.S. Provisional Application No. 60/397,696, which was filed on
Jul. 22, 2002.
BACKGROUND OF THE INVENTION
[0002] This invention relates to an automotive control module that
includes a unique base plate that is snap-fit to a module housing
with an integrated connector to enclose a printed circuit board
within the housing, and which simultaneously provides a heat sink
to cool the printed circuit board and associated electronics.
[0003] Automotive control modules include electronics and software
that are used to control various vehicle systems. For example,
control modules are used to control engines, automatic transmission
shifts, transfer case clutching and declutching, etc. Control
modules traditionally have a plastic or steel housing, a printed
circuit board (PCB) and associated electronics, and a connector
that connects to a vehicle wire harness. The housing is mounted to
a vehicle structure with fasteners.
[0004] During vehicle operation, the electronics on the PCB
generate a significant amount of heat, which must be drawn away
from the PCB to prevent over-heating. Traditionally, a heat sink
plate has been fastened first to the PCB, and then to the housing,
with a separate housing cover being used enclose the heat sink
plate and PCB within the housing. The housing cover is fastened to
the housing with rivets or screws to provide a secure
attachment.
[0005] This control module configuration has several disadvantages.
A significant number of components are required, which increases
material and manufacturing costs. Further, this configuration is
difficult and time consuming to assemble.
[0006] Thus, it is desirable to have a simplified automotive
control module that can provide sufficient cooling in an enclosed
environment for the PCB, as well as overcoming the other above
mentioned deficiencies with the prior art.
SUMMARY OF THE INVENTION
[0007] An automotive control module includes a housing with a
snap-fit cover plate that provides a heat sink and encloses control
electronics within the housing. The control electronics are mounted
to a printed circuit board (PCB) that is positioned within a cavity
formed in the housing. The PCB can have electronics mounted on
either or both of the upper or lower surfaces that form the
board.
[0008] The cover plate is preferably formed from aluminum and
includes a generally flat body portion with indentations that form
surfaces that are positioned in close proximity to the PCB, but do
not actually contact the PCB. The cover plate utilizes these
surfaces to form a heat sink for cooling the control electronics
mounted to the PCB. Optionally, or in addition to the indentations,
the cover plate includes a plurality of fins to improve heat
transfer from the PCB to the cover plate.
[0009] The housing is preferably formed from a plastic material and
includes a bottom portion, a first pair of opposing outer side
walls extending upwardly from the bottom portion, and a second pair
of opposing outer side walls extending between both of the first
pair of opposing outer side walls. The first and second pairs of
outer side walls cooperate with the bottom portion to define the
cavity. The housing also includes a pair of opposing inner side
walls positioned within the cavity in an orientation parallel to
and spaced apart from the first pair of opposing outer side
walls.
[0010] In one disclosed embodiment, resilient tabs are formed on
the first pair of opposing outer side walls. The resilient tabs
move outwardly from an initial position in response to a snap-fit
insertion force applied against the cover plate. The cover plate is
pushed against the housing until a bottom surface of the cover
plate abuts against a top edge surface of the inner side walls. The
resilient tabs then return to their initial position and grip a top
surface of the cover plate. Thus, the cover plate is sandwiched
between the resilient tabs and the top edge of the inner side walls
and serves as both a heat sink and a protective cover.
[0011] In one disclosed embodiment, resilient tabs are formed on
the opposing inner side walls of the housing and are snap-fit into
openings formed within transversely extending edge portions of the
cover. In this configuration, the cover includes a base portion
with the opposing edge portions being bent approximately ninety
degrees such that the edge portions can be inserted between the
inner and outer opposing side walls. The tabs gripping bore
surfaces that form the openings in the cover to secure the cover to
the housing. In this embodiment the cover also serves as both a
heat sink and a protective cover.
[0012] The subject automotive control module utilizes fewer
components, has decreased manufacturing costs, and is easier to
assemble than traditional control modules. These and other features
of the present invention can be best understood from the following
specifications and drawings, the following of which is a brief
description.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] FIG. 1 a schematic view of an automotive control module in
communication with a vehicle system.
[0014] FIG. 2 is an exploded view of an automotive control module
incorporating the subject invention.
[0015] FIG. 3 is a perspective view of the automotive control
module of FIG. 2 as assembled.
[0016] FIG. 4 is a view similar to FIG. 3 but with one corner cut
away in cross-section.
[0017] FIG. 5 is a cross-sectional view, partially broken away, of
an alternate embodiment.
[0018] FIG. 6 is a perspective view of an alternate embodiment of a
cover plate.
[0019] FIG. 7 is a perspective view of the cover plate of FIG. 6
attached to the automotive control module.
DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT
[0020] An automotive control module 10 generates a control signal
12 that is communicated to a vehicle system 14. The vehicle system
14 can be any of various vehicle systems such as engine management,
transmission management, wheel drive management, braking
management, or other similar vehicle systems. Preferably, the
control module 10 uses the control signal 12 to manage a vehicle
transfer case system 14 to achieve all-wheel drive under
predetermined conditions.
[0021] As shown in FIG. 2, the control module 10 includes a housing
16, a printed circuit board (PCB) 18, and a cover plate 20. The PCB
18 supports a variety of control electronics. The PCB 18 is
preferably mounted to the housing 16 with a plurality of fasteners
24.
[0022] A connector portion 26 is formed within the housing 16. The
connector portion 26 cooperates with a plurality of pins 28 that
are soldered or press-fit into holes formed in the PCB 18. The
connector portion 26 mates with a corresponding connector portion
30 on a vehicle wire harness 32.
[0023] The housing 16 is preferably made from a plastic material
and includes a base or bottom portion 34, a first pair of opposing
outer side walls 36 that extend upwardly from the bottom portion
34, and a second pair of opposing outer side walls 38 that extend
upwardly from the bottom portion 34 and interconnect the first pair
of opposing outer side walls 36 to define a cavity 40. In other
words, the bottom portion 34 and first 36 and second 38 pairs of
opposing side walls cooperate together to define a generally
rectangular housing with an open top.
[0024] The housing 16 also includes a pair of inner side walls 42
with one inner side wall 42 being parallel to and spaced apart from
a corresponding one of the first pair of opposing outer side walls
36. The PCB 18 is positioned within the cavity 40 between the inner
side walls 42. Posts 44 (only one is shown in FIG. 2) are formed
within the housing 16 to receive the fasteners 24 that attach the
PCB 18 to the housing 16.
[0025] The cover plate 20 is preferably made from aluminum or other
similar metallic material. The cover plate 20 includes a generally
flat body portion 46 with an upper surface 48 and a bottom or lower
surface 50. In the preferred embodiment, the body portion 46 is
formed from a stamped aluminum piece and includes at least one
indentation 52. The indentations 52 form a recess on the upper
surface 48 of the cover plate 20 and a corresponding extrusion on
the lower surface 50. The indentation 52 defines an indentation
surface 54 that is non-coplanar with both the upper 48 and lower 50
surfaces of the cover plate 20.
[0026] When the cover plate 20 is assembled to the housing 16, the
indentation 52 is positioned in close proximity to an upper surface
56 of the PCB 18, but does not actually contact the PCB 18. The
cover plate 20 utilizes the indentations 52 to form a heat sink for
cooling the control electronics 22 mounted to the PCB 18. A thermal
conductive paste 58 is applied the upper surface 56 of the PCB 18
in areas that do not interfere with the electronics 22. The paste
58 facilitates heat transfer from the PCB 18 to the cover plate 20
to cool the electronics 22. When the paste 58 cures, an approximate
distance of at least 0.3 millimeters is maintained between the
bottom surface of the indentations 52 and the PCB 18. This
configuration provides optimal heat transfer without risking
electrical shorts that could result if there were direct contact
between the cover plate 20 and the PCB 18.
[0027] The cover plate 20 is also snap-fit to the housing 16 to
enclose the PCB 18 within the housing 16. Thus, the cover plate 20
serves a dual purpose of a heat sink and a protective cover. In the
embodiment shown in FIGS. 2-4, housing 16 includes resilient
members that grip the cover plate 20 in a snap-fit attachment.
These resilient members include at least one resilient tab 60 on
each of the first pair of opposing outer side walls 36. Preferably,
a pair of tabs 60 are formed on each of the outer side walls
36.
[0028] The tabs 60 are integrally formed on an inner surface 62 of
the outer side walls 36 and extend to a flexible tip 64. The tabs
60 and a portion of the outer side walls 36 flex outwardly away
from an initial position in response to a snap-in insertion force
being applied to the cover plate 20. The cover plate 20 is pushed
against the housing 16 until the lower surface 50 of the cover
plate 20 abuts against a top edge surface 66 of the inner side
walls 42. Once the cover plate 20 is in abutting contact with the
inner side walls 42, the tabs 60 and outer side walls 36 return to
their initial position with the flexible tips 64 now being in
gripping engagement with the upper surface 48 of the cover plate
20, as shown in FIG. 3. Thus, the cover plate 20 is sandwiched
between the tabs 60 and the top edge surface 66 of the inner side
walls 42, as shown in FIG. 4.
[0029] The cover plate 20 can be easily removed from the housing 16
by exerting a bending force against the outer side walls 36 to
reduce the gripping force between the tabs 60 and cover plate 20.
The cover plate 20 can then be popped out to provide access to the
PCB 18 and associated electronics 22. Thus, the control module 10
can be easily serviced or repaired and the cover plate 20 can be
easily re-installed.
[0030] An alternate snap-fit attachment is shown in FIG. 5. In this
embodiment, the cover plate 20 includes a pair of edge portions 70
(only one is shown) that extend transversely to a generally planar
main body portion 72. Preferably, the edge portions 70 are bent
approximately 90 degrees relative to the body portion 72 and are
positioned in a gap 74 formed between the inner 42 and outer 36
opposing side walls. A plurality of resilient tabs 76 is formed on
each of the inner opposing side walls 42. The tabs 76 are received
in openings 78 that are formed in the edge portions 70. The tabs 76
and associated wall portions bend away from an initial position as
the cover plate 20 is pushed against the housing 16 and return to
the initial position once distal ends 80 of the tabs 76 are
received in gripping engagement with bore surfaces that define the
openings 78.
[0031] An alternate embodiment of a cover 90 is shown in FIGS. 6
and 7. The cover 90 is comprised of a plate body 92 that defines an
upper surface 94 and a lower surface 96. A plurality of fins 98 are
formed on the upper surface 94 and extend away from the PCB 18. The
fins 98 preferably extend in a longitudinal direction along the
length of the plate body 92 and are spaced apart from one another
in a lateral direction across the width of the plate body 92.
[0032] Open spaces 100 on the upper surface 94 are formed such that
the fins 98 do not interfere with the tabs 60. The open spaces 100
can extend along the entire length of the plate body 92 as shown in
FIG. 6 or shorter fins 102 can be formed at these locations, as
shown in FIG. 7.
[0033] The cover 90 is preferably made from an extrusion process
and includes at least one indentation 104 that defines an
indentation lower surface 106 that is positioned in close proximity
to the PCB 18. The fins 98 formed on an upper indentation surface
108 are preferably taller than the fins extending from the upper
surface 94 of the plate body 92. The combination of the indentation
104 and variable height fins 98 greatly improves heat transfer from
the PCB 18 to the cover 90.
[0034] The subject provides an automotive control module that
requires fewer components, has decreased manufacturing costs, and
is easier to assemble than traditional control modules. Also, one
of the benefits with the subject invention is that the cover plate
20 serves as both a heat sink and a protective cover for the PCB
18. Further, the assembly process is improved and simplified
because the PCB 18 is mounted first to the housing 16 with the
cover plate 20 being snap-fit to the housing. Although a preferred
embodiment of this invention has been disclosed, a worker of
ordinary skill in this art would recognize that certain
modifications would come within the scope of this invention. For
that reason, the following claims should be studied to determine
the true scope and content of this invention.
* * * * *