RAM AIR FLAP SYSTEM
An assembly for increasing air flow to a vehicle cooling system includes a portion of a cooling fan shroud, the portion having a face defining an opening therethrough, and a plurality of support members extending from the face. A flap includes a plurality of apertures proximal to an edge. Each aperture of the plurality of apertures is formed to receive one of the plurality of support members for coupling the flap thereto. A clearance fit formed between the apertures and the support members permits movement of the flap from a first position generally parallel to the face to a second position in response to a flow of air.
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The present invention relates to ram air flap systems for vehicles, and specifically to a ram air flap system for increasing air flow to portions of a vehicle cooling system at increased vehicle speeds.
SUMMARYIn one embodiment of an assembly for increasing air flow to a vehicle cooling system, the assembly includes a portion of a cooling fan shroud, the portion having a face defining an opening therethrough, and a plurality of support members extending from the face. A flap includes a plurality of apertures proximal to an edge. Each aperture of the plurality of apertures is formed to receive one of the plurality of support members for coupling the flap thereto. A clearance fit formed between the apertures and the support members permits movement of the flap from a first position generally parallel to the face to a second position in response to a flow of air.
In one embodiment of a cooling fan shroud for a vehicle, the cooling fan shroud includes a cooling fan shroud face having a primary opening therethrough for a cooling fan, a plurality of secondary openings therethrough, and a plurality of support members extending from the face adjacent each secondary opening. A flap includes a plurality of apertures proximal to an edge, each aperture of the plurality of apertures formed to receive one of the plurality of support members for coupling the flap thereto. A clearance fit formed between the apertures and the support members permits movement of the flap from a first position generally parallel to the shroud face to a second position in response to a flow of air.
In one embodiment of a method of producing a cooling fan shroud, the method includes injection molding a shroud portion having a face defining an opening therethrough, a plurality of support members extending from the face, and a guide member adjacent the opening and extending from the face. The method further includes coupling a flap to the plurality of support members. The coupling includes flexing the flap to engage the support members of the plurality of support members.
In one embodiment of an assembly for increasing air flow to a vehicle cooling system, the assembly includes a portion of a cooling fan shroud. The portion has a face defining an opening therethrough and a plurality of support members extending from the face. A flap includes a plurality of apertures proximal to an edge, each aperture of the plurality of apertures formed to receive one of the plurality of support members for coupling the flap thereto. A clearance fit formed between the apertures and the support members permits movement of the flap from a first position generally parallel to the face to a second position in response to a flow of air. The flap is retained on the shroud portion at least partially by one or more elastic members attached to the shroud portion or formed as an integral part of the shroud portion. The elastic members are flexed during engagement of the apertures with the support members.
Other aspects of the invention will become apparent by consideration of the detailed description and accompanying drawings.
Before any embodiments of the invention are explained in detail, it is to be understood that the invention is not limited in its application to the details of construction and the arrangement of components set forth in the following description or illustrated in the following drawings. The invention is capable of other embodiments and of being practiced or of being carried out in various ways. Also, it is to be understood that the phraseology and terminology used herein is for the purpose of description and should not be regarded as limiting. The use of “including,” “comprising,” or “having” and variations thereof herein is meant to encompass the items listed thereafter and equivalents thereof as well as additional items. And as used herein and in the appended claims, the terms “upper”, “lower”, “top”, “bottom”, “front”, “back”, and other directional terms are not intended to require any particular orientation, but are instead used for purposes of description only.
The fan shroud 20 is preferably an injection-molded uniform component, of which separate portions include features of each individual flap assembly 100. The portions represent sections of the fan shroud 20 and are preferably integrally formed concurrently with the molding of the shroud 20, but in some applications may be separate injection-molded sections added to a fan shroud (with necessary modifications).
The portion 110 further includes a plurality of support members 144 extending from the rear face 128. The support members 144 are generally hook-shaped and define a contoured supporting surface 148 for securing the flap 120, further described below. The support members 144 can be evenly spaced laterally across the rear face 128, or may be offset toward one of the portion edges 142, or may alternatively be mirrored about an approximate centerline bisecting the width W of the portion 110.
In some embodiments, the support members 144 adjoin a lateral arcuate recess 152 that permits operational deflection of the flap 120 to an open position, as will be further described. The recess 152 is preferably molded with the fan shroud 20 but can optionally be machined or otherwise formed subsequent to the molding process. As shown most clearly in
As shown in
The flap 120 is sized to cover the opening(s) 132 when in a closed position, which can be considered substantially parallel to the rear face 128. A plurality of apertures 174, the edges of which are generally rounded to reduce stress concentration, are similarly punched or cut from the flap 120 near a top edge 178 and spaced to receive the plurality of support members 144.
Because the width of the assembly 100 can vary from application to application, a continuous film can be punched or cut to length to form a flap corresponding to a particular width and having a predetermined aperture separation. In such a situation, not all apertures 174 need to correlate with a support member 144. The flap itself may include areas of differing thickness for reinforcement purposes, for example, an additional supporting rib or ribs 180 formed during the extrusion process.
Referring to
Referring to
In operation, as the vehicle speed increases, the velocity of the air relative to the vehicle increases. The position of the assembly 100 within the cooling fan shroud 20 exposes the openings 132 frontally to this air. The interaction of air with the flap 120 (due to dynamic pressure effects) deflects the flap 120 from a first position rearward to a second position, shown in
Referring to
Referring to
As shown in
As illustrated, when the flap 240 is in a non-flexed condition, the apertures 250 are spaced wider than what would permit a simple passing of the apertures 250 over the support members 224. To secure the flap 240 to the shroud body 210, a user must force the first and second edges 248 toward each other, flexing the flap 240, as shown in
The shroud portion 262 includes two support members 276 extending from the front face and generally shaped as ‘mushrooms’ or buttons with an undercut surface 280. A flap 284 is a generally planar member with two apertures 288 geometrically configured for elastic expansion. For example, the primary oval shape of each aperture 288 in the flap 284 as shown in
Additional support structure and flap aperture configurations permit simplified assembly while preventing separation of the flap from the fan shroud during operation. For example,
During assembly, passing the flap apertures 324 over the respective support members 314 concurrently deflects the elastic element 330 frontward toward the recess 334. The deflection permits the flap 320 to pass fully over the support members 314. Once in position, the flap 320 is moved laterally (leftward in
The shroud and flap features of the aforementioned embodiments are in no way limiting and, for example, the support members may include one or three or more support members, which could embody differing shapes having the characteristic of retaining the flap to the shroud during operation. The shroud and flap may include additional surface finishes and treatments (e.g., stretching, coating, printing, or tempering) or other work subsequent to molding, e.g., rounding or bending of corners and edges, or the addition of further cutouts, notches, grooves, or indentations in an effort to improve aerodynamics and acoustics, and to minimize air leaks. In some applications, a sealing lip can be formed on a bottom edge of the flap for such a purpose. In other applications, the outer contour of the flap may contain recesses or other features to facilitate packaging and overcome space restraints.
Referring to
Referring to
In operation, the deflection of the flap 650 due to interaction with the oncoming ram air deflects the flap 650 upward from a first position to a second position, as shown most readily in
The ram air flap assemblies and systems herein described are relatively easy to manufacture and, because the flaps are punched or cut from a thick-walled, extruded or rolled film, reduce material and manufacturing costs. Because deformation is not necessary during operational opening and closing of the flap(s), the greater wall thickness provides a more robust design with which to withstand engine compartment operating or maintenance conditions, including moisture, heat, vehicle fuel, steam jet cleaning, gravel or particulate impact, and splash water. In addition, the straightforward linear movement of the flap onto the support members effects comparatively quicker and easier assembly.
Various features and advantages of the invention are set forth in the following claims.
Claims
1. An assembly for increasing air flow to a vehicle cooling system, the assembly comprising:
- a portion of a cooling fan shroud, the portion having a face defining an opening therethrough, and a plurality of support members extending from the face; and
- a flap including a plurality of apertures proximal to an edge, each aperture of the plurality of apertures formed to receive one of the plurality of support members for coupling the flap thereto, wherein a clearance fit formed between the apertures and the support members permits movement of the flap from a first position generally parallel to the face to a second position in response to a flow of air.
2. The assembly of claim 1, wherein the cooling fan shroud includes a recess integrally formed in the face adjacent the plurality of support members, wherein the recess accommodates movement of the edge as the flap moves from the first position to the second position.
3. The apparatus of claim 1, wherein the shroud portion further includes at least one guide member adjacent to the recess and extending from the face, the guide member cooperative with at least one support of the plurality of supports to limit movement of the flap to the second position.
4. The apparatus of claim 3, wherein the second position is approximately 60° from the first position.
5. The apparatus of claim 1, wherein the flap blocks the opening in the first position.
6. The apparatus of claim 1, wherein the flap is punched from one of an extruded and a rolled film.
7. The apparatus of claim 1, wherein the flap is cut from one of an extruded and a rolled film.
8. The apparatus of claim 1, wherein the flap is constructed of a thermoplastic, elastomer, or metal.
9. The apparatus of claim 1, wherein the opening is a first opening and wherein the face further defines a second opening therethrough, the second opening separated from the first opening by a support member.
10. The apparatus of claim 1, wherein the flap further includes a reinforcement member generally orthogonal to the edge.
11. The apparatus of claim 1, wherein the recess is arcuate in cross-section.
12. The apparatus of claim 1, wherein the shroud portion further includes opposing pivot supports projecting across a portion of the opening and defining a pivot axis operable to support a rotatable flap.
13. The method of claim 1, wherein the thickness of the flap is between 0.05 to 0.8 mm.
14. A cooling fan shroud for a vehicle, the cooling fan shroud comprising:
- a cooling fan shroud face having a primary opening therethrough for a cooling fan, a plurality of secondary openings therethrough, and a plurality of support members extending from the face adjacent each secondary opening; and
- a flap including a plurality of apertures proximal to an edge, each aperture of the plurality of apertures formed to receive one of the plurality of support members for coupling the flap thereto, wherein a clearance fit formed between the apertures and the support members permits movement of the flap from a first position generally parallel to the shroud face to a second position in response to a flow of air.
15. A method of producing a cooling fan shroud, the method comprising:
- injection molding a shroud portion having a face defining an opening therethrough, a plurality of support members extending from the face, and a guide member adjacent the opening and extending from the face; and
- coupling a flap to the plurality of support members, wherein the coupling includes flexing the flap to engage the support members of the plurality of support members.
16. The method of claim 15, wherein coupling a flap to the plurality of support members means coupling a flap having a plurality of apertures along a first edge, the apertures spaced to each receive one of the plurality of support members.
17. The method of claim 15 wherein coupling a flap to the plurality of support members means coupling a flap having a thickness of between 0.05 to 0.8 mm.
18. The method of claim 16, wherein coupling the flap to the plurality of support members includes elastically deforming the flap to position each of the plurality of apertures over each of the plurality of support members.
19. The method of claim 16, wherein coupling the flap to the plurality of support members includes elastically deforming the flap between the guide member and the plurality of support members such that an end of each support member of the plurality of support members extends through a respective aperture of the flap.
20. The method of claim 18, further including guiding the flap along the guide member into a recess.
21. The method of claim 15, wherein injection molding the shroud portion means injection molding the guide member to be disposed cooperatively with at least one support of the plurality of supports to limit operable movement of the flap.
22. An assembly for increasing air flow to a vehicle cooling system, the assembly comprising:
- a portion of a cooling fan shroud, the portion having a face defining an opening therethrough, and a plurality of support members extending from the face; and
- a flap including a plurality of apertures proximal to an edge, each aperture of the plurality of apertures formed to receive one of the plurality of support members for coupling the flap thereto, wherein a clearance fit formed between the apertures and the support members permits movement of the flap from a first position generally parallel to the face to a second position in response to a flow of air, and wherein the flap is retained on the shroud portion at least partially by one or more elastic members attached to the shroud portion or formed as an integral part of the shroud portion, the elastic members being flexed during engagement of the apertures with the support members.
Type: Application
Filed: Mar 15, 2013
Publication Date: Mar 27, 2014
Applicant: ROBERT BOSCH GMBH (Stuttgart)
Inventors: Markus Liedel (Pegnitz), Joseph Paolicchi (Novi, MI), Andrea DeSimone (Watertown, MA), Michael Sortor (Lexington, MA), Edward H. Gray (Rockingham, VT)
Application Number: 13/841,238
International Classification: F04D 29/52 (20060101);