U.S. patent application number 13/772886 was filed with the patent office on 2013-08-29 for active grill shutter vane design and vehicle system.
This patent application is currently assigned to Shape Corp.. The applicant listed for this patent is Shape Corp.. Invention is credited to Jeffrey A. Blair, Todd W. Pastrick, Charles A. Seiter, Samuel I. Smith.
Application Number | 20130223980 13/772886 |
Document ID | / |
Family ID | 49003057 |
Filed Date | 2013-08-29 |
United States Patent
Application |
20130223980 |
Kind Code |
A1 |
Pastrick; Todd W. ; et
al. |
August 29, 2013 |
ACTIVE GRILL SHUTTER VANE DESIGN AND VEHICLE SYSTEM
Abstract
An integrated assembly includes a vehicle bumper system, and
upper and lower air shutter sections with subassembled shutter
vanes movable between closed and open positions, an actuator
mechanism for moving the shutter members between positions. When in
the fully open position, the shutter vanes are aerodynamically
designed to minimize air drag, both as air flows past the vanes and
also during after-vane airflow (and during after-bumper-beam
airflow). When in the fully closed vane position, the vanes seal
against each other to provide a highly efficient and leak-resistant
air-blocking assembly.
Inventors: |
Pastrick; Todd W.; (Spring
Lake, MI) ; Smith; Samuel I.; (Allendale, MI)
; Seiter; Charles A.; (Howell, MI) ; Blair;
Jeffrey A.; (Zeeland, MI) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Shape Corp.; |
|
|
US |
|
|
Assignee: |
Shape Corp.
Grand Haven
MI
|
Family ID: |
49003057 |
Appl. No.: |
13/772886 |
Filed: |
February 21, 2013 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
61603003 |
Feb 24, 2012 |
|
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|
Current U.S.
Class: |
415/1 ;
415/148 |
Current CPC
Class: |
F01D 5/00 20130101; B60K
11/085 20130101; Y02T 10/88 20130101 |
Class at
Publication: |
415/1 ;
415/148 |
International
Class: |
F01D 5/00 20060101
F01D005/00 |
Claims
1. A shutter vane apparatus for use in an active grill shutter
apparatus for a vehicle, comprising: a vane body including opposing
first and second aerodynamic surfaces forming a leading end, a
middle, and a trailing end, with the trailing end tapering
generally to a narrow edge; the first surface including a concave
region defining a concavity along the leading end, and extending
along a convex region from a rear of the concavity to a thickest
part of the middle portion and then forming a first narrowing
tapering surface to the trailing end; the second surface including
a convex region extending from the leading end downwardly and
rearwardly to the thickest part and then forming a second narrowing
tapering surface to the trailing end.
2. An apparatus including first and second vanes each having a
shape of the vane body defined in claim 1, wherein the second
surface of the trailing end of the first vane is shaped to fit
mateably into the concavity in the leading end of the first surface
on the second vane.
3. The apparatus defined in claim 2, including a linkage connected
to the first and second vanes, and an actuator connected to the
linkage for selectively moving the first and second vane
simultaneously.
4. The apparatus defined in claim 1, wherein the vane body includes
outboard and inboard ends, each including a pivot pin for pivotally
mounting the vane body for rotation about a longitudinal axis
extending along the vane body.
5. The apparatus defined in claim 4, wherein at least one of the
outboard and inboard ends includes an arm extending away from the
longitudinal axis.
6. The apparatus defined in claim 5, wherein the arm includes a
pivot and a linkage connected to the pivot.
7. The apparatus defined in claim 6, including an actuator
connected to the linkage and adapted for connection to a vehicle
electrical control unit.
8. The apparatus defined in claim 1, wherein the vane body has a
cross section with a length to height ratio of 35:7.
9. The apparatus defined in claim 1, wherein the concavity is about
2-4 mm deep.
10. A grill shutter system for a vehicle having a front end
including a bumper reinforcement beam, a power plant, and a cooling
component, comprising: a shutter frame defining an opening for
passage of air and configured for attachment to the front end in
front of the cooling component; a plurality of vanes with
aerodynamic upper and lower surfaces that are operably positioned
in the shutter frame, the vanes being movable between a closed
position where mating surfaces of adjacent vanes abut to block
airflow through the shutter perimeter frame, an open position where
the aerodynamic upper and lower surfaces allow airflow through the
perimeter frame with minimal drag, and at least one partially-open
position therebetween that allows limited airflow; and an actuator
and linkage connected to the vanes for moving the vanes between the
operative positions.
11. The system defined in claim 10, including an engine control
unit operably connected to the actuator for operating the plurality
of vanes to optimize vehicle performance.
12. The system defined in claim 10, wherein one of the mating
surfaces of the vanes includes a longitudinal concavity defined
along a leading edge of each vane, and where another one of the
mating surfaces includes a trailing end shaped to fit matingly into
the concavity on an adjacent one of the vanes when in the closed
position.
13. The system defined in claim 10, wherein each of the vanes
includes a vane body with outboard and inboard ends, each including
a pivot pin for pivotally mounting the vane body for rotation about
a longitudinal axis extending along the vane body.
14. The system defined in claim 13, wherein one of the outboard and
inboard ends includes an arm extending away from the longitudinal
axis.
15. The system defined in claim 14, wherein the arm includes a
pivot connected to the linkage.
16. The system defined in claim 13, wherein the vane body has a
cross section with a length to height ratio of 35:7.
17. The system defined in claim 12, wherein the concavity is about
2-4 mm deep.
18. The system defined in claim 13, where an interior of the vane
body includes polymeric material and also gas pockets which reduce
a total weight of the vane body.
19. A method for a vehicle having a front end including a bumper
reinforcement beam, a power plant, and a cooling component,
comprising: providing a shutter frame defining an opening for
passage of air to the cooling component and configured for
attachment to the front end in front of the cooling component;
providing a plurality of vanes with aerodynamic upper and lower
surfaces that are operably positioned in the shutter frame, the
vanes being movable between a closed position where mating surfaces
of adjacent vanes abut to block airflow through the shutter
perimeter frame, an open position where the aerodynamic upper and
lower surfaces allow airflow through the perimeter frame with
minimal drag, and at least one partially-open position therebetween
that allows limited airflow; and selectively moving the vanes
between the operative positions to control air flow to the cooling
component.
20. The method defined in claim 19, wherein the mating surfaces
include a longitudinal concavity on a leading edge of each of the
vanes and a mating shape on a trailing edge of adjacent ones of the
vanes, and where the step of moving the vanes to the closed
position causes the trailing edge of the adjacent vanes to move
into the concavity of the mating surfaces on adjacent vanes.
Description
[0001] This application claims benefit under 35 USC .sctn.119(e) of
provisional application Ser. No. 61/603,003, filed Feb. 24, 2012,
entitled ACTIVE GRILL SHUTTER VANE DESIGN AND SYSTEM, the entire
contents of which are incorporated herein.
BACKGROUND
[0002] The present invention relates to grill shutter systems for
selectively controlling airflow to a vehicle engine/power plant or
other vehicle cooled component, and more particularly relates to a
shutter system with aerodynamic vanes for low drag pass through
when open but also non-leaking air blockage when closed.
[0003] Components, such as grills and the like, that affect airflow
around a vehicle front end and airflow into a vehicle engine
compartment are important for several reasons. For example, the
components must provide good airflow for engine cooling, stylistic
appearance for customer satisfaction and acceptance, aerodynamic
effect for good gas mileage, good impact characteristics (and good
repairability) in case of a vehicle crash, and a competitive cost
of manufacturing. This has traditionally been accomplished by using
static components, such as grills, baffles, stylish fascia, and the
like. However, some vehicle manufacturers are now looking for
airflow systems that provide an ability to actively manage and
selectively optimize airflow based on engine temperature and
operating conditions (such as during an engine cold start or after
engine warm up), vehicle speed (such as idle or at highway speeds),
and environmental conditions (such as hot humid day versus sub-zero
cold dry night). Notably, any such airflow control system must
preferably be reliable, durable, robust, cost-competitive to
manufacture and assemble, maintain design flexibility, not cause
other problems (such as noise and/or rattle concerns), and be
capable of integration into the overall vehicle design. Due to
conflicting design requirements, the details of any such system are
not clear.
SUMMARY OF THE PRESENT INVENTION
[0004] A shutter vane apparatus for use in an active grill shutter
apparatus for a vehicle, comprising a vane body including opposing
first and second aerodynamic surfaces forming a leading end, a
middle, and a trailing end, with the trailing end tapering
generally to a pointed edge, the first surface including a concave
region defining a concavity along the leading end, and extending
from the concavity to a thickest part of the middle portion and
then forming a first-narrowing tapering surface to the trailing
end, the second surface including a convex region extending from
the leading end downwardly and rearwardly to the thickest part and
then forming a second-narrowing tapering surface to the trailing
end.
[0005] An object of the present invention is to provide an active
grill shutter system for a vehicle that is aerodynamic and provides
minimal pressure drop when vanes are fully open, yet that resists
air leakage and blow-by when vanes are fully closed.
[0006] An object of the present invention is to provide an active
grill shutter system for a vehicle with vanes that are
aerodynamically shaped, but also sufficiently rigid and having
physical properties in terms of beam and bending and torsion
strengths sufficient to avoid undesired bending and distortion
under a wide range of operating conditions commonly encountered by
modern vehicles.
[0007] An object of the present invention is to provide an active
grill shutter system with vanes adapted to self-open via airflow
from vehicle motion when an actuator controlling vane-position
fails.
[0008] An object of the present invention is to provide an active
grill shutter system for a vehicle that is an effective air block
when vanes are closed but also provides minimal pressure drop when
fully open, and where the vanes are resistant to freezing in a
closed or open positions, and resistant to mud and dirt (or other
contaminations) causing malfunction, and resistant to damage from
object impacts.
[0009] An object of the present invention is to provide an active
grill shutter system for a vehicle where vanes abuttingly engage
when in a fully closed position to provide a strong seal against
air leakage and blow-by.
[0010] These and other aspects, objects, and features of the
present invention will be understood and appreciated by those
skilled in the art upon studying the following specification,
claims, and appended drawings.
BRIEF DESCRIPTION OF DRAWINGS
[0011] FIG. 1 is a side view of a vehicle with an active grill
shutter vane system embodying the present invention;
[0012] FIG. 1A is a side exploded view of the bumper system and
shutter system of FIG. 1;
[0013] FIG. 2 is a front view, slightly perspective, of the shutter
system of FIG. 1;
[0014] FIGS. 3-4 are partial vertical cross-sectional (side) views
showing two vanes interconnected by a common link, the vanes being
shown in closed and open positions, respectively;
[0015] FIGS. 5-6 are perspective views, from opposite ends, of a
vane from FIG. 2;
[0016] FIG. 7 is a vertical cross-sectional view through the vane
in FIG. 5;
[0017] FIGS. 8A-8C are views of three vanes, FIG. 8A being in the
open position, FIG. 8B being in the halfway open position, and FIG.
8C being in a closed position;
[0018] FIG. 9 is a cross-sectional view of a vane from FIG. 7, and
showing airflow characteristics in the form of pressure gradient
lines around the vane during significant vehicle speeds such as
about 50 mph;
[0019] FIG. 10 is a cross-sectional view of a vane from FIG. 7, and
showing airflow characteristics in the form of velocity vectors
around the vane during significant vehicle speeds such as about 50
mph; and
[0020] FIGS. 11-12 are side elevational views showing air flowing
past a bumper reinforcement beam and across the present vanes and
into a radiator.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0021] It is to be understood that the present invention is not
limited to the particular embodiments of the invention described
below, as variations of the particular embodiments may be made and
still fall within the scope of the appended claims. It is also to
be understood that the terminology employed is for the purpose of
describing particular embodiments, and is not intended to be
unnecessarily limiting. Where a range of values is provided, it is
understood that each intervening value is encompassed within the
invention, including upper and lower limits, unless otherwise
stated.
[0022] The present invention is generally directed toward an
aerodynamically enhanced active grill shutter apparatus 100 (also
called an "assembly" or "system" herein) with improved
aerodynamically designed vanes for use in connection with a
vehicle, typically a passenger or commercial vehicle such as a car
or truck. In the present innovation, a cross-sectional profile of
the vanes has been developed so that when closed, the vanes
effectively seal their airflow opening, with minimal air leakage.
When the vanes are fully open, the vanes maximize airflow over and
under the vanes as well as minimize the trailing wake conditions of
airflow, thus minimizing drag, as will be discussed in more detail
herein. The vane design allows significant airflow velocity
increases as air flows across the vanes, thus decreasing air drag,
when compared to previously used vane shapes. The active grill
shutter vane design/system of the present invention can contain one
or more vanes. When a plurality of vanes are used, they make up a
shutter system that operates to seat one vane against the other
when the vanes are in a closed position.
[0023] The present disclosure focuses in particular on the present
aerodynamically-shaped vanes, and their use in a shutter system
that leads to a particularly advantageous vehicle grill shutter
system. More specifically, the aerodynamic shape of the present
vanes is believed to be very effective in assisting with improved
gas mileage and engine/vehicle performance. By way of illustration,
the FIGS. 1-2 focus on the environment and placement of the present
shutter system, and the FIGS. 3-12 focus more specifically on the
present aerodynamic vane shape. Notably, the present disclosure is
sufficient for a person skilled in this art to understand the
present invention and its potential uses. However, for the reader's
benefit, reference is made to a modular shutter system with vanes
as disclosed in pending U.S. application Ser. No. 13/186,949, by
inventors Evans et al, filed Jul. 20, 2011, entitled INTEGRATED
ENERGY ABSORBER AND AIRFLOW MANAGEMENT STRUCTURE. The entire
contents of that application '949 are incorporated herein for its
disclosure and teaching.
[0024] FIGS. 1-2 illustrate an integrated active grill shutter
assembly 100 as installed on a vehicle 101 having a vehicle front
end with a bumper system (including fascia 102, rigid bumper
reinforcement beam 103, polymeric energy absorber 104 with crush
lobes, and an optional low-positioned pedestrian impact bar or air
dam (not shown), a cooling component 106 (e.g. a radiator), a power
plant 107 (e.g. internal combustion engine), a hood 108, and front
wheels 109. The illustrated shutter assembly 100 includes a unitary
molding that includes an upper support section 111 (such as an
attachment flange or integral beam) for attachment to a front end
structure, an upper air shutter perimeter frame section 112,
bumper-attachment bracket members 113 (behind the beam 103), and a
lower air shutter perimeter frame section 114 with lower attachment
flanges 114A. It is noted that the components 111-114 can be a
single molding or can be multiple moldings, and that they can be
attached together as an assembly or supported independently on the
vehicle 101 front end. For example, the illustrated sections
111-114 are molded of a polymeric material as a single molding,
such as a structural polymer adapted for absorbing energy upon
receiving a crushing impact. Such polymers are commercially
available from several companies, including NetShape, a division of
Shape Corporation in Grand Haven, Mich. It is contemplated that the
sections 111-114 could be molded as two or more separate moldings
and assembled together as a unit, before or during vehicle
assembly.
[0025] The illustrated grill shutter assembly 100 includes four
airflow openings (also called "quadrants" herein), each holding a
set of vanes 140 movable between open, partially-open, and closed
positions. It is to be understood that a scope of the present
invention includes fewer or more airflow openings, differently
sized openings, and with each having more or fewer vanes therein.
The illustrated upper perimeter frame section 112 (FIG. 2) includes
walls 115-118 and 119-122 forming right and left openings, with the
top walls 115 and 119 and the bottom walls 116 and 120 forming
continuous frame-like structures across the vehicle's front end.
Multiple vanes 140 (three illustrated) include ends pivoted to the
side walls 117-118 and to the side walls 121-122 in the right and
left openings. A center wall 123 combines with inboard side walls
118 and 121 to form a cavity for receiving a vertical linkage 150
that attaches to an arm 141 on each vane 140. An actuator 154 is
attached to a top of the linkage 150 for operating the vanes 140 in
both right and left upper openings.
[0026] Similarly, the illustrated lower perimeter frame section 114
(FIG. 2) includes walls 125-128 and 129-132 forming right and left
openings, with the top walls 125 and 129 and the bottom walls 126
and 130 forming continuous structures across the vehicle front end.
Multiple vanes 140 (five illustrated) include ends pivoted to the
side walls 127-128 and to the side walls 131-132 in the right and
left openings. A center wall 133 combines with inboard side walls
128 and 131 to form a cavity for receiving a vertical linkage 134
that attaches to the arm 141 on each vane 140. (Depending on
functional requirements, the system can be designed with a single
arm only on one end of each vane, or potentially an arm on each end
of the vanes 140.) The illustrated brackets 113 are U-shaped and
form a rearwardly-facing (or forwardly-facing) cavity that mates
onto the bumper beam 103 so that the bumper beam 103 is generally
between the upper and lower frame sections 112 and 114. The
brackets 113 extend between the lower wall 116 (on the upper frame
section 112) and the top wall 125 (on the lower frame section 114).
The brackets 113 include an attachment site 136 for attachment to a
front of the bumper beam 103.
[0027] For convenience, only the upper left airflow opening and
vanes therein of the present grill shutter apparatus 100 are
described below. However, it is to be understood that the other
openings include similar structure and are operated similarly.
Notably the apparatus 100 can include a single actuating mechanism
(e.g. a single AC stepper motor) that operates all quadrants (i.e.
all vanes) simultaneously, or multiple actuating mechanisms that
operate all quadrants individually, depending on vehicle function
and control requirements. Also, the openings can be different
lateral widths or different heights.
[0028] For reference, the upper left quadrant/corner will be
referred to as shutter section 100A, and it controls airflow
through the opening in the left hand opening of shutter frame
section 112 toward the cooling component 106 in the engine
compartment of the vehicle 101 (i.e. a motor and/or generator
and/or power generating unit and/or batteries). Control of the
shutter section 100A (i.e. control of vane movement) is by the
vehicle engine control system, and is intended to optimize
operation of the vehicle's power plant.
[0029] Shutter section 100A includes a molded frame body comprising
walls 115-118 interconnected to form a window opening 145. A
plurality of horizontal shutter members (vanes 140) are positioned
in the opening 145, and are pivoted at each end at pivot locations
to rotate about an axis 146 (FIGS. 3-4) for movement between a
closed air-blocking position (FIG. 3) and an open air-passing
position (FIG. 4). The vertical linkage 150 (FIGS. 3-4) is attached
to the arm 141 of each vane 140 at location 151 which is spaced
from the vane's pivot location (axis 146), so that by pulling the
linkage 150 vertically, the vanes 140 are selectively
simultaneously rotated closed (FIG. 3) or opened (FIG. 4). A
trailing end 152 of the vane 140 includes a thinned tip, and the
relatively-thick-nosed leading end 153 includes a concavity 142 for
matably engaging the thinned tip on an adjacent vane when in the
closed position (FIG. 3). The engagement of the thinned tip into
the concavity 142 causes a good air seal, which results in very low
air leakage of the shutter section 100A when the vanes 140 are
fully closed, such as over 80 percent increase in air
restriction/blockage compared to earlier tested vanes.
[0030] An actuator mechanism includes the vertical linkage 150 and
further includes the actuator 154 connected to the linkage 150 and
operably connected to the vehicle engine control system, so that
when actuated, the actuator 154 can lift (or lower) the linkage 150
vertically, thus rotating the vanes 140. When released, the linkage
150 drops, with the assistance of a spring bias (see spring 155,
FIGS. 3-4) and/or by gravity (and potentially assisted by a
power-down movement by the actuator 154, if desired). It is
contemplated that the actuator 154 can be any of a variety of
different extendable devices, such as electrical, air, hydraulic,
or other.
[0031] In the present innovation, the shutter members 140 are
aerodynamically designed and their pivots arranged so that if the
actuator 154 or linkage 150 becomes decoupled from the shutter
members 140, or if the actuator 154 become non-functional for some
reason, the pressure of airflow (from a moving vehicle) will tend
to move the shutter members 140 to an open position. This can be
accomplished by placing the pivot near to but slightly above a
center line of the vanes 140 so that a greater air pressure results
slightly below the center line.
[0032] Each vane 140 typically has an integrally-formed pivot pin
160 formed on each end of the vane. The pivot pin 160 snaps into a
mating pivot socket in the associated side wall of the frame
section 112 to allow rotational movement of the individual vane 140
in its perimeter frame. Each vane 140 includes an angularly and
upwardly extending drive arm 141 with offset pivot connection at
drive arm pin 151 that connects to the actuator-driven mechanical
linkage 150. As noted above, the linkage 150 and actuator 154
provide controlled movement of the individual vane 140 about the
pivot axis defined by the pivot pins 160 on each end of the vane
140. The present vane's physical and cross-sectional properties are
a significant improvement, not only in their ability to enhance
airflow characteristics, but also to provide torsional and tensile
and bending strength to the overall vane. Torsional, tensile and
bending strength are necessary to overcome binding and
vane-length-distortion due to severe environmental conditions such
as snow, ice, and mud buildup, as well as extreme environmental
factors such as temperature changes and conditions.
[0033] As discussed above, the individual vanes 140 of the present
invention are aerodynamically designed for a variety of improved
airflow characteristics including velocity and pressure gradients,
strength, and functionality. We consider the cross-sectional shape
of the present vanes to be particularly novel and unobvious because
of its ability to provide a tight air-blocking seal when the vanes
are in a fully closed position. Also, we consider the
cross-sectional shape of the present vanes to be particularly novel
and unobvious, because by using the present design, our testing
shows that a grill opening can pass approximately the same amount
of air whether the present vanes are present or not. In previous
vane designs, the grill opening had to be increased if vanes were
added due to resistance to air pass-through caused by those early
vane designs. This is seen as a tremendous benefit since modern
vehicles are becoming increasingly smaller and more aerodynamic.
Thus, any shutter design that eliminates the need for a larger air
pass-through opening is a significant advantage.
[0034] In particular, as shown in FIG. 7, each vane 140 has
aerodynamically shaped upper and lower surfaces 147, 148 that form
the bottle-nose-shaped leading end 153, a relatively thick but
slowly-narrowing tapered middle section, and a relatively thin and
more-rapidly-narrowing pointed trailing end 152 (also called "tail
end" herein). The upper surface and lower surfaces 147, 148 of the
vanes 140 have an aerodynamic shape to efficiently and effectively
pass air with minimal air drag when in the fully open position
(FIG. 8A), but have a mating shape so that the tail of one and
leading end of another abuts to efficiently and effectively
matingly engage and block passage of air with minimal air leakage
when closed (FIG. 8C). Specifically, as shown in FIG. 7, the upper
surface 147 of the leading end 153 includes a concave region 170
extending rearwardly and then upwardly from a leading point 169 on
the vane 140. The concave surface 170 thus forms a channel adjacent
the leading tip of the vane 150. A convex surface 171 extends from
the concave surface 170 rapidly building to a thickest
cross-sectional point 172 on the vane 140, and then extends
rearward and downward with a gradual taper to the tip of the tail
end 152 with an aerodynamic continuously-curved shape.
[0035] The lower surface of the leading end 153 includes a convex
surface 175 that extends vertically downward and then rearwardly
from the leading point 169 on the vane 140, rapidly building
thickness as it extends rearward toward a thickest point 176 (below
the thickest cross-sectional point 172), and then extends with a
gradual taper rearward and upward to the tip of the tail end 152. A
combination of the upper and lower surfaces 147 is reminiscent of a
cross-section of an airplane wing, with the exception that the vane
140 is designed for minimal air drag and easy pass-through of air
when fully open (and the present vane 140 is not designed to create
lift), and the vane 140 is designed for maximum blockage of air by
abutting engagement with adjacent vanes 140 when fully closed.
[0036] Restated, the individual vane 140 includes a top portion
that is smooth and aerodynamically shaped, for creating minimal
drag and maximum-pass through including a leading edge curvilinear
shape having a relatively early buildup of thickness and that
gradually tapers to the relatively-thin tail end. The tail end is
the leeward (wind-trailing) end of the vane, when the vane is in a
fully open position. The vane 140 has a windward (upstream) surface
that is generally bottlenose dolphin-shaped in the windward
(upstream) direction, as shown in FIG. 7. The windward surface has
an upper half that includes a convex downwardly extending portion
that transitions into a concave downwardly extending portion that
then transitions into the pointed tip portion. The tip portion
receives and overlaps a segment of the tail end of a second vane
when the vanes are in the closed position (see FIG. 8C). The tip
portion is designed with a recess (also called a "channel" herein)
to receive a segment of the bottom portion near the tail end of the
vane, thus providing a good air seal preventing air leakage when
the vanes are in a fully closed position. The bottom portion has an
upwardly curvilinear section that forms a part of the windward
surface, and extends between the tail end receiving portion and the
bottom portion of the vane 140. The vane 140 has a maximum
thickness near a rear of the convex curved part (generally
perpendicular to the bottom surface), and the surfaces have a
curvilinear aerodynamic shape and combine to form an aerodynamic
taper as they extend to the narrow trailing tip of tail end.
[0037] The pivot pin 160 (FIG. 6) on each vane 140 has a particular
shape to avoid malfunction in the harsh environment often
encountered by vehicles. The illustrated pivot pin 160 includes a
collar portion 180 and an outwardly extending cylindrical shaped
pin body 181. The pivot pin 160 further includes a cap portion 182.
The cap portion 182 has a plurality of tapered protrusions 183 that
meet at a circular center section 184 and form a generally
plus-shape when the pivot pin 160 is viewed from its outer end.
Each tapered protrusion 183 has a substantially flat top surface
and extends from the outwardly extending cylindrical pin body 181
to the circular center section 184. An aerodynamic side 185 of the
vane 140 has the upwardly extending angled planar drive arm 141
that extends from a location adjacent the pivot pin 160 on side 185
at an upward angle to a drive arm pin 151. A center of the drive
arm pin 151 (also called "linkage attachment pivot" herein) is
approximately above the tail end 152 of the vane 140 when the vane
140 is in a fully open position. The drive arm pin 151 has an
outwardly extending cylindrical-shaped body 186 that is divided
into two portions by a collar section 187. The outward facing
surface of the drive arm pin 151 is planar with curved side
sections extending circumferentially about the end to create a
smooth transition between the cap and side wall of the outwardly
extending body 186.
[0038] The linkage 150 (FIGS. 3-4) connects to the drive arm pin
151, allowing the actuator 154 (which is connected to one end of
the linkage 150, such as its upper end) to move the plurality of
vanes 140 simultaneously. As illustrated, a single electrical
actuator (e.g. a AC stepper motor) is connected to the upper end of
the linkage. However, it is contemplated that a single actuator can
be connected to any part of the linkage. Also, it is contemplated
that multiple actuators can be used (simultaneously or as desired),
or that a variety of different actuators (i.e. electrical motor,
electrical solenoid, pneumatic, hydraulic, etc.) could be used. The
illustrated arrangement includes a single actuator for moving all
shutter vanes simultaneously, but it is contemplated that different
actuators can be used to operate different sets of vanes, such as
for selectively opening or closing one area (such as the area in
front of a radiator) at a different time than another area (such as
an area in front of a transmission cooler or air conditioner
unit).
[0039] The present illustrated actuator 154 (FIGS. 3-4) is a
reversible AC electrical stepper motor capable of 2.5 N-m peak
torque output, and it drives the linkage 150 in part through
mechanical advantage. This peak torque allows the actuator 154 to
move the vanes 140, even when the vanes 140 are "stuck" (or are
resisting movement) in a given position due to mud, ice, or other
condition. Notably, the vanes must have sufficient strength
properties to endure such loads from the actuator 154 without
failure and without undergoing permanent deformation or undesired
bending. In short, the vanes must have sufficient physical
structure and properties to satisfy beam strength, bending
strength, torsion strength requirements, and impact requirements
for use in a grill opening in a vehicle front end. For example, the
illustrated present system is capable of freeing the vanes when
"adhered" together in the closed position by a 1 mm (or more)
thickness of mud. Notably, the present system controls will include
a sensor or other feature that identifies when the shutter vanes
fail to open.
[0040] A cross-sectional shape of a vane (also called a "blade"
herein) and of a shutter system can be varied depending on
functional requirements of particular applications/vehicles. As
shown in FIG. 7, the cross-sectional dimensions of a preferred vane
140 for a typical passenger vehicle, according to the present
invention, include an overall fore-aft length of the vane as
approximately 30-40 mm (or more preferably about 35 mm) and the
height of the vane as approximately 6-9 mm (or more preferably
about 7 mm). The channel (concavity 142) at the leading end 153 is
typically about 2-4 mm (preferably 3 mm) in length and about 2-4 mm
(preferably 3 mm) deep when compared to the thickest
cross-sectional point 172. The ratio of these dimensions may also
be employed to vary the size of the improved vane(s) for other
vehicles or perhaps other uses. The illustrated vane pivots 160 and
linkage attachment (pivot) 151 have a pivot diameter of about 6-9
mm or larger (or more preferably about 7 mm), and are designed to
avoid material failure at extreme test conditions.
[0041] The pivots 160 are designed to permit (facilitate) snap
assembly, as well as to reduce plugging and friction build-up
within the assembled pivots. The material of the vanes (and the
material of the mating components) can be varied to obtain the
coefficient of friction and other component properties desired. The
illustrated components were made from a glass-filled nylon or
glass-filled polypropylene, depending on the system functional
requirements. By way of example, the present illustrated vanes 140
successfully passed a 30 degree one-time twist test (assembly
condition simulation), a 15 degree permanent twist, and a low speed
bumper impact test, as well as passing airflow leakage/blockage
testing, an anti-squeak and rattle testing, splash testing
(simulating flooded road conditions), and vane torsional stiffness
and bending stiffness testing. Also, the illustrated vanes 140 were
twisted 90 degrees over 6 seconds and showed a 61 percent increase
in torsional rigidity over a base line drive vane, and showed a 35
percent increase in deflection strength over a baseline drive vane,
while providing improved/reduced sound pressure levels (dBAs of
squeaks and rattles) over other systems.
[0042] It is contemplated that these vanes can be molded in a
conventional manner out of glass filled nylon or polypropylene
resin with no additional additives necessary. However, it is to be
understood that the vanes 140 can be molded by alternative means.
For example, our testing shows they also can be molded using an
additive "foaming" or "blowing" agent, in pelletized form, blended
with the plastic resin pellets prior to the molding operation. This
is done to reduce a weight of the vane. During the molding process
these pellets break down into a liquid under pressure in the screw
barrel. Once this liquid enters the cavity and a pressure drop
occurs, they change to a gaseous form. These micro-bubbles stay
concentrated in the center of the mass and create a micro-porous
structure. This reduces mass and increases part stiffness as
indicated in the bar graphs. The vanes tend to skin and have a
thicker/denser surface layer and a lower-weight less-dense internal
structure, thus placing material at an outer area where the denser
material has a greatest positive effect on beam tensile, bending,
and torsion strength and physical properties, while also reducing
overall weight.
[0043] FIG. 8A shows a plurality of vanes 140 (three illustrated)
that operate in conjunction with each other to regulate airflow.
FIG. 8A shows the three vanes in a fully open position. FIG. 8B
shows the vanes in a 45 degree partial-open position, and FIG. 8C
shows three vanes in a fully closed position with the tail end
receiving portions of two of the vanes engaging the tail end
portions of the vanes above them. Notably, the uppermost vane 140
will engage the upper-adjacent structure in the perimeter frame
supporting the vanes, and the lowermost vane 140 will engage the
lower-adjacent structure in the perimeter frame, such that the
entire opening is closed and sealed against air pass-through when
the vanes are closed. Where desired, the upper-adjacent structure
and the lower-adjacent structure replicates the structure of a
mating vane, so that the air seal is optimal. The vanes are
interconnected by a linkage 150 to an actuator 154 (see FIGS. 3-4);
the actuator 154 being connected to vehicle electrical controls (or
pneumatic or other controls) for optimal control and airflow based
on engine and vehicle parameters. For example, in a vehicle with a
diesel (or gas) engine that is running in a very cold temperature,
the engine control may keep the shutter system (i.e. vanes) closed
for an extended period of time.
[0044] FIG. 9 schematically shows the airflow 138, and the airflow
characteristics/pressure gradients that result from air blowing
past a vane 140 according to an embodiment of the present
invention. Significantly, a lowest measured pressure (vacuum)
gradient 193 extends only a short distance past (e.g. a 2-3 mm) the
trailing end 152 of the vane 140 (FIG. 9), a next pressure gradient
194 extends a relatively small distance further, and a last
measured gradient 195 extends approximately 35 mm beyond the tail
end, such that considerably less drag is created than when
non-aerodynamic vanes (or less-aerodynamic vanes) are used. Note
FIGS. 11, 12 which compare similar pressure gradients in an
inefficiently-shaped vane 204 (FIG. 11) and in an
efficiently-shaped vane 140 (FIG. 12), which are discussed further
below. FIG. 10 schematically shows the airflow characteristics by
velocity vectors of airflow around a vane 140 according to the
present invention, with short arrows leading up to the vane showing
ambient air speed, and with the elongated arrows close to the vane
140 indicating an increased air speed, especially the doubly
elongated arrows adjacent the vane 140.
[0045] This increased air speed caused by the vane 140 allows the
present vane 140 to convey a same quantity of air past the vane 140
and through a "given opening size" without excessive resistance (as
compared to the absence of a vane in the "given opening size").
Notably, our testing shows that the present system, including vanes
140, creates close-to-zero resistance to air pass-through when the
vanes are in the fully open position. We consider this significant,
because it is our understanding that some grill shutter systems
were (or are) being designed with an enlargement factor so that
sufficient air could pass through the shutter system and grill
opening. In other words, known grill shutter systems were being
designed larger than the "unobstructed" air opening would have to
be in order to allow sufficient air pass-through, because of the
air resistance present due to the grill shutter system. The present
grill shutter system does not require any such "oversized" opening,
which is a tremendous advantage in vehicle design since vehicles
are continuing to be designed as more compact and with smaller
"package space" for front end vehicle components.
[0046] FIG. 11 schematically shows a generally inefficient grill
shutter with inefficiently designed vane 204 where air flowing
through the inefficient shutter system forms small air dead spots
205, 206 for a considerable distance behind the vanes (i.e. the
dead spots extending approximately to the radiator) and also forms
a large dead spot 205 behind the bumper beam. FIG. 11 is intended
for comparative purposes to show inefficiencies that resulted when
testing an inefficient "early" vane design (as compared to the
present system shown in FIG. 12). Specifically in FIG. 11, a bumper
fascia 200 is shown supported by a rigid bumper reinforcement beam
201 and polymeric energy absorber 202, with a grill shutter system
with vanes 204 located above the beam 201. As shown in FIG. 11, the
arrangement causes a large dead spot 205 of dead air behind the
bumper system 200-202 (i.e. in front of the radiator/cooling system
of the vehicle). Further, in the illustrated design of FIG. 11,
smaller (but significant) dead spots 206 occur behind the
(inefficient) vanes 204, since the (inefficient) vanes 204 cause
small dead air spots of low pressure and non-uniform airflow into
and through the air conditioning condenser/radiator 203 generally
across the radiator 203, but especially behind the bumper system
200-202.
[0047] By contrast, as shown in FIG. 12, the present grill shutter
system 100 with vanes 140 according to an embodiment of the present
invention provides significantly increased mass airflow rate (see
elongated arrows passing along the aerodynamic surfaces 147-148 of
vane 140), and more uniform laminar distribution of airflow through
the shutter system to the cooling component 106 (for any given
grill opening size). Further, a curved-wall baffle 190 is attached
to the bumper beam 103 and includes a curvilinear wall that extends
along an aerodynamic line rearwardly and downwardly across the area
behind the bumper beam 103. A curved-wall baffle 190 assists in
directing airflow from a lower portion of the upper shutter
downwardly into the area behind the bumper beam 103, thus greatly
reducing a size and vacuum level in the dead space of air in that
area. By the present shutter apparatus 100, a more uniform and
effective stream of air is distributed to the cooling component
106, optimizing the cooling (heat transfer) process.
[0048] The present inventive vanes 140 can be made by many
different means, but in a preferred form the vanes are produced
from an injection mold of plastic utilizing an embedded carbon
dioxide or nitrogen gas in a melt flow forming process. This
process allows for internal expansion of the plastic and permits
the greater cross-sectional thickness of the vanes according to the
present invention.
[0049] The vanes of the present disclosure reduce drag in a number
of ways including:
[0050] 1. Directly minimizing the drag associated with incoming
airflow colliding with vanes and adjacent structures. Additionally,
this collection of components keeps the incoming air from
separating as the air flows past the vanes. Tips of the vanes
reduce turbulent airflow and cause a more laminar airflow into the
area of the vanes.
[0051] 2. Accelerating and compressing the incoming airflow as it
travels between the vanes and collection of components. Also, the
airflow over and between (and past) the vanes is more laminar and
uniform.
[0052] 3. Directing the attached high velocity incoming airflow
from the vanes as the air moves past the vanes keeps the airflow
"attached". Injecting this high velocity airflow into the wake
reduces the size of the wake and adds energy to it. This increases
the pressure in the wake, thereby reducing the resulting drag.
[0053] The present system offers several advantages. The
aerodynamic shape of the vanes provides enhanced airflow
characteristics, including secondary benefits of enhancing cooling
system performance and vehicle aerodynamics. Also, the aero vane
design includes a material modifier that enhances part
characteristics, including better dimensional stability,
minimization of part warpage, elimination of thick wall sink,
reduction in scrap on unbalanced cavitations, and potential for
density reduction. Also, the snap-fit design reduces assembly cost
on vane insertion and requires no flexing of the vane bodies during
insertion. The integrated duct/housing and perimeter frame design
(FIGS. 1-2) provides for reduced assembly cost post-molding. The
spring-assisted linkage design provides opening delay for increased
freeze break away, allows for mechanical advantage drive,
eliminated need for drive vane, and promotes even torque
distribution. The snap-in actuator design provides a robust motor
location and retention, eliminates actuator retention clip, and
otherwise facilitates assembly, repairability, durability, and
robustness of assembly. The present shutter design is flexible,
durable, robust, cost-competitive, and supports improved vehicle
performance, while maintaining a minimum vehicle weight.
[0054] It is to be understood that variations and modifications can
be made on the aforementioned structure without departing from the
concepts of the present invention, and further it is to be
understood that such concepts are intended to be covered by the
following claims unless these claims by their language expressly
state otherwise.
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