SYSTEM AND METHOD FOR CLAMPING A CHASSIS COVER
A system is provided for securing a cover having a first surface onto a chassis having a rim, the rim having a second surface. The system comprises a clamping rail and a fastener coupled to the rail. The clamping rail is configured to form a loop that circumferentially engages the first surface and the second surface and, when constricted, produces a first force substantially coplanar with the loop. The fastener is configured to constrict the rail, the rail and the first and second surfaces configured to produce a second force having a component substantially orthogonal to the loop when the rail is constricted.
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The present invention generally relates to clamps, and more particularly relates to a system for clamping a cover to a power electronic bay chassis.
BACKGROUND OF THE INVENTIONIn recent years, advances in technology have led to substantial changes in the design of automobiles. One of the principal changes involves the complexity, as well as the power usage, of various electrical systems within automobiles, particularly alternative fuel vehicles. During this time, the requirement for electrical power generation in automotive applications has risen dramatically. This trend had been in place for decades but has accelerated in the last few years largely due to the advent of hybrid, electric, and fuel cell based vehicles. Such vehicles often use electrochemical power sources, such as batteries, ultracapacitors, and fuel cells, to power the electric motors that drive the wheels, sometimes in addition to another power source, such as an internal combustion engine.
In hybrid and fuel cell vehicles, a Power Electronics Bay (PEB) performs many necessary functions related to power conversion and distribution. PEB enclosures or chassis are typically designed to provide housed components with both environmental protection and shielding from incoming and outgoing electromagnetic interference (EMI). A PEB chassis generally comprises a body and cover constructed of either stainless steel or aluminum, each member having a machined sealing flange along an outer edge, pre-drilled to accommodate fastening bolts. One or both of the flanges typically has a groove to support a metal-impregnated, conductive, silicone o-ring to form an environmental seal when the cover of the enclosure is bolted closed. EMI shielding is provided by the continuous conductive shrouding formed by the metallic structure of the body and cover in conjunction with the conductivity of the o-ring in the seam. Because strong and evenly distributed clamping pressure is needed to provide a reliable seal, reinforcement of sealing flanges is typically required to provide adequate rigidity and prevent warping from the substantial compressive forces generated by a plurality of bolts spaced 1″ to 2″ apart. As a result, part count and overall vehicle weight are increased along with the complexity of associated assembly processes. Further, conductive, EMI shielding o-rings are often nickel-filled and add additional expense while contributing no additional environmental protection compared to conventional, non-conducting silicone rubber o-rings.
Accordingly, it is desirable to provide a system for clamping a cover to a PEB chassis that is easily installable and eliminates the need for multiple fasteners. Further, it is desirable that such a system provides EMI shielding along the seams and corners of a PEB chassis without the use of a conductive o-ring. Furthermore, other desirable features and characteristics of the present invention will become apparent from the subsequent detailed description and the appended claims, taken in conjunction with the accompanying drawings and the foregoing technical field and background.
SUMMARY OF THE INVENTIONA system is provided for securing a cover having a first surface onto a chassis having a rim, the rim having a second surface. The system comprises a clamping rail and a fastener coupled to the rail. The clamping rail is configured to form a loop that circumferentially engages the first surface and the second surface and, when constricted, produces a first force substantially coplanar with the loop. The fastener is configured to constrict the rail, the rail and the first and second surfaces configured to produce a second force having a component substantially orthogonal to the loop when the rail is constricted.
A method is provided for clamping a cover having a first surface onto a chassis body having a rim, the rim having a second surface. The method comprises the steps of circumferentially aligning a clamping rail to the first and second surfaces, constricting the circumference of the clamping loop to engage the first and second surfaces with a first force substantially coplanar with the loop, the clamping loop and the first and second surfaces being configured to convert at least a portion of the first force to a second force substantially orthogonal to the loop that clamps the cover onto the rim, and fixing the clamping loop in its circumferentially restricted position.
The present invention will hereinafter be described in conjunction with the following drawing figures, wherein like numerals denote like elements, and
The automobile 10 may be any one of a number of different types of automobiles, such as, for example, a sedan, a wagon, a truck, or a sport utility vehicle (SUV), and may be two-wheel drive (2WD) (i.e., rear-wheel drive or front-wheel drive), four-wheel drive (4WD), or all-wheel drive (AWD). The automobile 10 may also incorporate any one of, or combination of, a number of different types of engines (or actuators), such as, for example, a gasoline or diesel fueled combustion engine, a “flex fuel vehicle” (FFV) engine (i.e., using a mixture of gasoline and alcohol), a gaseous compound (e.g., hydrogen and/or natural gas) fueled engine, or a fuel cell, a combustion/electric motor hybrid engine, and an electric motor.
In the exemplary embodiment illustrated in
Referring to
Prior to clamping, cover 152 rests on the top of seal 188 forming a gap 218 between undersurface 200 and rim surface 198. The underside of rim 168 comprises a rim bevel 216 that extends outward from sidewall 148 terminating with a vertical rim lip 176. The top peripheral surface of cover 152 has an edge bevel 214 terminated by a short vertical cover lip 190. Rail 164 is configured to fit over edge bevel 214 and rim bevel 216 when clamped and comprises a center section 208 that couples together upper and lower arms 202 and 204 respectively. Each arm may terminate with an outwardly curving upper and lower leading edge 206 and 226 respectively, to facilitate aligning rail 164 with rim 168 and cover 152 prior to clamping. While rail 164 has been illustrated as having angled, symmetric upper and lower arms 202 and 204, it should be understood that arms may be asymmetric with respect to angle and/or length. For example, as illustrated in
Rail 164 provides EMI shielding over gap 218 all along its length including around chassis corners as will be described in further detail below. Such shielding results from factors that include the metallic construction and shape of rail 164, and reduces the amount of EMI passing between rim 168 and cover 152 from sources either internal or external to a chassis. Center section 208 of rail 164 may be configured to be substantially perpendicular to gap 218 to provide improved coverage and greater attenuation of such EMI signals.
While at least one exemplary embodiment has been presented in the foregoing detailed description, it should be appreciated that a vast number of variations exist. It should also be appreciated that the exemplary embodiment or exemplary embodiments are only examples, and are not intended to limit the scope, applicability, or configuration of the invention in any way. Rather, the foregoing detailed description will provide those skilled in the art with a convenient road map for implementing the exemplary embodiment or exemplary embodiments. It should be understood that various changes can be made in the function and arrangement of elements without departing from the scope of the invention as set forth in the appended claims and the legal equivalents thereof.
Claims
1. A system for securing a cover having a first surface onto a chassis having a rim, the rim having a second surface, the system comprising:
- a clamping rail configured to form a loop that circumferentially engages the first surface and the second surface and, when constricted, produces a first force substantially coplanar with the loop; and
- a fastener coupled to the rail configured to constrict the rail, the rail and the first and second surfaces configured to produce a second force having a component substantially orthogonal to the loop when the rail is constricted.
2. A system according to claim 1, wherein the fastener further comprises a threaded rod coupled to the rail, the threaded rod configured to adjustably constrict the rail.
3. A system according to claim 1, wherein the fastener further comprises a lever rotatably coupled to the rail and having a closed position, the lever configured to constrict the rail when the lever is actuated into the closed position.
4. A system according to claim 1, wherein the fastener is rotatably coupled to the clamping rail.
5. A system according to claim 1, wherein the clamping rail is coupled to a backing strap.
6. A system according to claim 1, wherein the fastener is coupled to a backing strap.
7. A system according to claim 1, wherein the clamping rail further comprises an upper arm that engages the first surface and a lower arm that engages the second surface.
8. A system according to claim 7, wherein the upper and lower arms have different lengths.
9. A system according to claim 7, wherein the rim further comprises a corner and the upper and lower arms of the rail are notched proximate to the corner.
10. A system according to claim 1, wherein the rail further comprises corner braces, and wherein the fastener is coupled to the corner braces and is configured to constrict the rail by adjusting the corner braces.
11. A system according to claim 1, wherein at least one of the rim and the cover further comprises a groove, and further comprising a seal that engages the groove and seals the chassis when the cover is clamped onto the rim.
12. A system according to claim 1, wherein the rim further comprises a corner and the fastener is configured to conform to the corner.
13. A system according to claim 1, wherein the clamping rail is further configured to reduce electromagnetic interference passing between the cover and the rim.
14. A method for clamping a cover having a first surface onto a vehicular chassis body having a rim, the rim having a second surface, the method comprising the steps of:
- circumferentially aligning a clamping loop to the first and second surfaces;
- constricting the circumference of the clamping loop to engage the first and second surfaces with a first force substantially coplanar with the loop, the clamping loop and the first and second surfaces being configured to convert at least a portion of the first force to a second force substantially orthogonal to the loop that clamps the cover onto the rim; and
- fixing the clamping loop in its circumferentially restricted position.
15. The method of claim 14, further comprising the step of inserting a seal between the cover and the rim.
16. The method of claim 14, wherein the clamping loop further comprises a first end and a second end and the step of fixing the clamping loop further comprises fixing the clamping loop by welding the first and second ends together.
17. A system for clamping a cover onto a rim of a vehicular chassis, the cover having a first surface residing in a first plane, and the rim having a second surface residing in a second plane, the system comprising:
- a clamping rail circumscribing the first and second surfaces, the clamping rail comprising: a first arm configured to engage the first surface and residing in a third plane; and a second arm configured to engage the second surface and residing in a fourth plane, the rail generating a clamping force that clamps the cover to the rim when the rail is constricted and at least one of the first plane and the second plane is different than the third plane and the fourth plane, respectively; and
- a fastener coupled to the rail configured to constrict the rail.
18. A system according to claim 17, wherein the chassis further comprises a corner, and the first and second arms are notched proximate to the corner.
Type: Application
Filed: Oct 31, 2008
Publication Date: May 6, 2010
Applicant: GM GLOBAL TECHNOLOGY OPERATIONS, INC. (Detroit, MI)
Inventors: George R. Woody (Redondo Beach, CA), Edward P. Yankoski (Corona, CA), Terence G. Ward (Redondo Beach, CA), Brooks S. Mann (Redondo Beach, CA)
Application Number: 12/263,155
International Classification: B65D 45/34 (20060101); B65D 45/32 (20060101);