The present invention relates generally to motor vehicle air springs systems and inflatable air dam assemblies, and more particularly to an inflatable air dam assembly which is selectively inflated and deflated by integrated operation of the air springs system.
Motor vehicle air springs systems utilize compressed air operated leveling devices, as for example air springs and/or air spring over shock absorber modules or a combination thereof, to provide ride and leveling control of the vehicle. Such air suspension systems utilize an air compressor to provide a source of compressed air to the air operated leveling devices. In a typical configuration, as for example described in any of U.S. Pat. Nos. 4,829,436, 5,465,209, 6,698,778, and 7,617,031 the air compressor is selectively connected by electronically controlled solenoid valves to the air operated leveling devices, a compressed air reservoir (optional), an air intake, and an air exhaust. Most air suspension systems operate in an “open state” in the sense the excess air volume within the system is vented to the atmosphere at the exhaust and the source air for the compressor is drawn from the atmosphere at the intake; however, at least one air suspension system (see above cited U.S. Pat. No. 6,698,778) operates in a “closed state” in the sense that air is not exchanged with the atmosphere, wherein excess air volume is stored in an air reservoir and the source air for the compressor is either the air reservoir or the air springs.
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The motor vehicle air suspension system 10 includes four compressed air operated leveling devices 12 which may be air springs and/or air spring over shock absorber modules, or a combination thereof, a computer 14, a compressor/exhaust apparatus 16, an air drier 18, a pressure switch 20, a valve assembly 22, a plurality of air lines 24 and signal lines 26. The plurality of air lines 24 go to the four leveling devices 12 to provide pressurized air from the valve assembly 22. A road wheel 28 is associated with each leveling device 12. The computer 14 receives an ignition signal, vehicle speed signal and vehicle door disposition signal. The computer 14 controls the operation of each solenoid valve in the valve assembly 22. The computer 14 also receives input from four position sensors 32, one at each of the four road wheels 28 through the four signal lines 26, as well as other inputs 34, such as ignition, doors, speed, etc. The compressor/exhaust apparatus 16 selectively sources or vents air through the air drier 18. A master air line 30 runs from the pressure switch 20 to the valve assembly 22 which controls compressed air communication between the compressor/exhaust apparatus 16 and the individual leveling devices 12 in response to signals from the computer 14. The pressure switch 20 is optional, and is used to monitor the air pressure at each air leveling device 12.
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The air dam assembly 44 is comprised of a one-piece blow molded plastic assembly that includes generally a top wall 46, a bottom wall 48, a forward wall 50, and a rearward wall 52. These walls cooperate to define a hollow interior sealed air space 54, and the walls have thicknesses that prove the generally self supporting shape of
The forward wall 50 and the rearward wall 52 are each formed of a plurality of serially arranged horizontal extending pleats 66. A typical pleat 66 includes an upper pleat portion 68 and a lower pleat portion 70 that are joined together by an outer living hinge 72. Each of these pleats 66 is in turn connected to the adjacent pleat 66 by inner living hinges 74. Thus the forward wall 50 and the rearward wall 52 consist of alternating pleat portions 68 and 70 that are connected by living hinges 72 and 74 that are arranged in accordion fashion by which the forward and rearward walls can be folded and unfolded via flexure of the living hinges. These living hinges and pleats are formed in the blow-molding process of forming the air dam assembly 44.
The bottom wall 48 of the air dam assembly spaces apart the forward wall 50 and the rearward wall 52. A front lower lip structure 76 depends downwardly from the forward wall 50 and the bottom wall 48 to stiffen the lower edge of the air dam assembly 44.
The overall shape of the air dam assembly 44 is curved or arcuate when seen from above so that the air dam assembly will generally match the curvature of the front of the vehicle. More importantly, this curved shape of the air dam assembly 44 causes the pleats 66 to also follow the curved path and in so doing the curvature of the pleats 68 and 70 and living hinges 72 and 74 will cooperate to generally stiffen the forward wall 50 and the rearward wall 52 against movement that might be induced by the on rushing air stream as the vehicle is traveling at predefined speeds. Furthermore, the pleated shape of the forward wall 50 and rearward wall 52 will cooperate to maintain a reliable distance between the forward and rearward walls, thereby giving the air dam assembly 44 a predetermined shape against flexure in the fore and aft direction.
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It will be understood that the air dam assembly 44 can be blow molded in either the extended position of
A bidirectional deploy/stow system is utilized for moving the air dam assembly 44 between the extended (inflated) position of
Problematically, the addition of a separate compressor/motor, valves, air dryer, controller, etc, of the deploy/stow system for the inflatable air dam assembly 44 is not only costly, but contributes to increased vehicular weight and occupation of otherwise available space for other vehicular components.
Accordingly, what is needed in the prior art is some way to operate the deploy/stow functions of the air dam assembly utilizing the air springs system of the motor vehicle.
The present invention is an integrated pneumatic system for a motor vehicle in which inflatable air dam assembly inflation and deflation is operatively integrated with the air springs system of the motor vehicle, wherein the integration of shared components minimizes duplicity, thereby lowering vehicular weight and cost, while yet providing full functionality of all pneumatic systems of the motor vehicle.
The integrated pneumatic system according to the present invention includes a motor, air compressor, air dryer, valves (or valving), air lines and electronic controller, and provides pneumatic control over an inflatable air dam assembly and an air springs system, wherein the vehicle trim height adjustment of the air springs may be individual or collective, and wherein the vehicle trim height adjustment of the air springs and the inflation and deflation of the inflatable air dam assembly may be mutually coordinated with respect to vehicular speed and the duration of vehicular speed ranges so as to provide many advantages, including: optimized fuel mileage, improved vehicle ride quality minimized system mass and maximized system efficiency, as well as optimized vehicle road capability, head lamp leveling, etc.
Accordingly, it is an object of the present invention to provide an integrated pneumatic system for a motor vehicle in which inflatable air dam assembly inflation and deflation is operatively integrated with the air springs system of the motor vehicle, wherein the integration of shared components minimizes duplicity, thereby lowering vehicular weight and cost, while yet providing full functionality of all pneumatic systems of the motor vehicle.
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Each air spring 106, 108 is connected to a respective solenoid valve 110, 112 which are pneumatically connected in parallel to a first output 114 of a first three-way pneumatic valve 116. The motor 118 actuates the air compressor 120 which supplies compressed air to the input 122 of the first three-way pneumatic valve 116, after having passed through the air dryer 124. The air compressor 120 draws air from the atmosphere 126 via the output 128 and first input 130 of a second three-way pneumatic valve 132. A second output 136 of the first three-way pneumatic valve 116 connects to the input 138 of a third three-way pneumatic valve 140, wherein a first output 142 of the third three-way pneumatic valve connects to the inflatable air dam assembly 104. A second output 144 of the third three-way pneumatic valve 140 connects to the atmosphere 126. A second input 146 of the second three-way pneumatic valve 132 connects to the inflatable air dam assembly 104. The aforesaid connections are pneumatic connections provided by the pneumatic lines 148. The electronic controller 150 receives sensor data from sensors 156 as an input via data line 152, and outputs appropriate signals via data lines 154, based upon its programming, to the motor 118, the three-way pneumatic valves 116, 132, 140 and the solenoid valves 110, 112, 134, via data lines 154.
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From the foregoing disclosure, it will be evident that the following aspects pertain to the integrated pneumatic system according to the present invention. The system is preferably an open system, and jointly utilizes the motor, air compressor, air dryer, valves, and controller for both the air springs system and the inflatable air dam assembly.
Inflation and deflation of the inflatable air dam assembly and the raising and lowering of vehicle trim height provided by the air springs system, for example an air suspension system or a load leveling system, may be coordinated synergistically to cooperatively benefit operation of the motor vehicle. For example, for predetermined vehicle speeds for predetermined durations, the inflatable air dam assembly may be either inflated, deflated or held in the deflated or inflated configuration, and the air springs may raise, lower or hold steady the trim height (or height) of the vehicle, wherein the synergistic coordination is predetermined so as to optimize vehicle fuel economy, ride quality, vehicle appearance, road clearance, vehicle leveling, etc.
For example, when the vehicle speed is above a pre-defined speed threshold V1 for a duration T1, then the air compressor will be turned on and the valves set to inflate the inflatable air dam assembly; when the vehicle speed is below a pre-defined speed threshold V2 for a duration T2, then the air compressor will be turned on and the valves set to deflate the inflatable air dam assembly; when the vehicle speed is above a pre-defined speed threshold V3 for a duration T3, then the valves will be set to allow air to exhaust to atmosphere from (any one or all) of the air springs in order to lower the vehicle trim height; and when the vehicle speed is below a pre-defined speed threshold V4 for a duration T4, then the air compressor will be turned on and the valves set to deliver compressed air to (any one or all) of the air springs in order to raise the vehicle trim height, wherein the values of V1, V2, V3, V4, T1, T2, T3 and T4 are predetermined, as for example by modeling or empirical testing, for applicability to a certain vehicle and monitoring of road and vehicle operation conditions. Examples, merely for illustration and not limitation, of the aforesaid values may be as follows: V1=25 MPH (miles/hour), V2=20 MPH, V3=50 MPH, V4=45 MPH, T1=20 seconds, T2=20 seconds, T3=between 30 and 45 seconds, and T4=between 30 and 45 seconds.
Sensors for implementing the control logic of the controller may include: pressure sensors at various locations, preferably including over charge monitoring of the inflatable air dam assembly; trim height sensors; and inflatable air dam assembly configuration confirmation sensors. In this regard further, the integrated pneumatic system according to the present invention may further include an electronically controlled damping system for implementing a predetermined damping strategy; and system failure monitoring and failure mode diagnosis.
Each of the systems can be serviced separately. To service the air spring suspension system (air springs 106, 108, solenoid valves 110, 112), it is preferred to exhaust all the air from air spring first, as per
The dryer 124 can be regenerated during deflation of the air dam because air pressure and flow rate are relatively lower than that of the air springs. Another way to regenerate the air dryer 124, is to add a check valve (one end is between motor 120 and the dryer, and the other end between the motor 120 and the second three-way valve 132). To do this, set solenoid valves 110 or 112 to the open state, set the first three-way pneumatic valve 116 to the energized state, let air from air springs go through valves 110 or 112, 116, and 124, then the check valve, and then valve 132 to atmosphere 126. The check valve should be small orifice to limit the air flow rate.
To those skilled in the art to which this invention appertains, the above described preferred embodiment may be subject to change or modification. Such change or modification can be carried out without departing from the scope of the invention, which is intended to be limited only by the scope of the appended claims.