Abstract:
A portion of the housing of an air operated leveling device is configured to integrally include an air valve receptacle which receives thereinside a solenoid valve. The housing carries an air fitting and an electrical connector which are interconnected with the solenoid valve receptacle, and, in turn, the solenoid valve. The solenoid valve communicates with the air fitting and the interior of the housing to regulate pressure inside the housing in response to electrical signals sent to the electrical connector.

Description:
TECHNICAL FIELD 
     The present invention relates generally to motor vehicle air suspension systems, and more particularly to the compressed air leveling devices thereof. Still more particularly, the present invention relates to an integrated solenoid valve and air leveling device for a motor vehicle air suspension system. 
     BACKGROUND OF THE INVENTION 
     Motor vehicle air suspension systems utilize compressed air operated leveling devices, as for example air springs and/or air controlled shock absorbers 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 and 6,698,778, the air compressor is selectively connected, by electronically controlled solenoid valves, to the air operated leveling devices, a compressed air reservoir, an air intake, and an air exhaust. Most air suspension systems operate in an “open state” in the sense the excess pressure 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 pressure is stored in an air reservoir and the source air for the compressor is either the air reservoir or the air springs. 
     Turning attention now to  FIG. 1 , an example of a prior art motor vehicle suspension system  10  is depicted, as generally also shown and described in aforementioned U.S. Pat. No. 4,829,436 to Kowalik et al, issued on May 9, 1989 and assigned to the assignee hereof, the disclosure of which is hereby incorporated herein by reference. 
     The motor vehicle air suspension system  10  includes four compressed air operated leveling devices  12  which may be air springs and/or air operated shock absorbers, 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  22 . 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 sensors in three of the four road wheels  28  through the three signal lines  26 . 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  also provides a signal to the computer  14  when the air pressure to any leveling device falls below 35 psi so that incremented pressure is automatically provided to that leveling device. 
     Problematically, the solenoid valves are external to the leveling devices. What remains needed in the art is an improved motor vehicle air suspension system wherein the solenoid valves are integrated into the leveling devices, whereby provided would be lower cost, weight, package size, and component complexity, as well as improved environmental protection and retained integrity of air compression even if the air line is untowardly damaged. 
     SUMMARY OF THE INVENTION 
     The present invention is an integrated solenoid valve and air operated leveling device, as for example an air spring, air spring over damper module, air spring over strut module, or air jounce bumper. 
     According to the present invention, a portion of the housing of an air operated leveling device is configured to include an air valve receptacle for receiving thereinside a solenoid valve, wherein the integrated solenoid valve is connected by an air line to, for example, an air suspension system of the motor vehicle. 
     In the preferred embodiment of the integrated solenoid valve and leveling device according to the present invention, the housing of an air spring includes an integral solenoid valve receptacle internally disposed with respect to the air spring housing. The solenoid valve receptacle is composed of a solenoid valve chamber and a chamber cover, which is selectively connectable to the solenoid valve chamber, as for example by a snap fit or by threading. Either the piston or the cap portion of the housing of the air spring integrally includes the solenoid valve chamber. An air line fitting is externally disposed in the housing, wherein the air line fitting communicates with the solenoid valve chamber. The chamber cover includes an air passage opening which communicates with the solenoid valve chamber when the chamber cover is attached to the solenoid valve chamber. An electrical connector is disposed externally with respect to the housing adjacent the solenoid valve chamber, whereby an electrical connection can be made therefrom into the solenoid valve chamber. 
     In assembly of the preferred embodiment of the integrated solenoid valve and leveling device according to the present invention, the air spring is opened, as for example the bellows thereof is unclamped at one end, and the chamber cover removed from the solenoid valve chamber. A solenoid valve is placed into the solenoid valve chamber, wherein one air passage thereof interfaces with the air line fitting. Electrical connection is made between the electrical connector and the solenoid valve. The chamber cover is reattached to the solenoid valve chamber, as for example by snapping thereon, wherein the other air passage of the air valve projects, in sealing relation to the solenoid valve chamber, through the air passage opening of the chamber cover. The bellows is again closed. An electrical plug of an air suspension system is interfaced with the electrical connector. An air line is connected to the air line fitting. 
     In operation of the preferred embodiment of the integrated solenoid valve and leveling device according to the present invention, in response to electrical signals from the air suspension system, the solenoid valve regulates the air pressure within the air spring and the motor vehicle is provided with an air suspension via flexing of the bellows. Should an untoward event occur to the air line, such as for example a cut or break wherein pressure is lost, the air valve will nonetheless independently maintain pressure within the air spring. 
     Accordingly, it is an object of the present invention to provide an integrated solenoid valve and air operated leveling device, as for example an air spring, air spring over damper module, air spring over strut module, or air jounce bumper. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a schematic diagram of a prior art motor vehicle air suspension system. 
         FIG. 2  is a sectional view of an air spring with integrated solenoid valve according to a first embodiment of the present invention. 
         FIG. 3  is a detail sectional view of a portion of  FIG. 2 , showing in particular the solenoid valve and solenoid valve receptacle integrated with the housing of the air spring. 
         FIG. 4  is a detail sectional view, seen along line  4 - 4  of  FIG. 3 . 
         FIG. 5  is a sectional view of an air spring with integrated solenoid valve according to a second embodiment of the present invention. 
         FIG. 6  is a sectional view of an air spring with integrated solenoid valve according to a third embodiment of the present invention. 
         FIG. 7  is a sectional view of an air spring with integrated solenoid valve according to a fourth embodiment of the present invention. 
     
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Referring now to  FIGS. 2 through 7 , various aspects of an integrated solenoid valve and leveling device  100  according to the present invention are shown, wherein, merely by exemplification, the motor vehicle air suspension system  10  of  FIG. 1  may be interfaced therewith. 
     Referring now to  FIGS. 2 through 4 , a first preferred embodiment of the integrated solenoid valve and leveling device  100   a  is depicted. The leveling device is an air spring  104  having a housing  106  which includes a piston  106   p  and a cap  106   c . Flexibly interconnecting the piston  106   p  and the cap  106   c  is a bellows  108 . The bellows  108  is releasably connected at each of its ends to the housing  106 , wherein a first annular clamp  110   a  sealingly clamps a first end  108   a  of the bellows to an annular land  112  of the cap  106   c , and wherein a second annular clamp  110   b  sealingly clamps a second end  108   b  of the bellows to an annular land  115  of the piston  106   p . The air spring  104  is located in a motor vehicle suspension system, as for example the system  10 , wherein, for example, an axle floats relative to the frame based upon the cap  106   c  and the piston  106   p  being mutually separated by air pressure within the bellows. 
     Integrated with the housing  106  is a solenoid valve receptacle  114 . The solenoid valve receptacle  114  is composed of a solenoid valve chamber  116  which may be, for example, cylindrical, elliptical, or rectangular in shape, and a complementarily shaped chamber cover  118 , wherein the chamber cover is attached to the solenoid valve chamber so as to be selectively removable therefrom. 
     As shown at  FIG. 2 , the solenoid valve chamber  116  is integrally formed of the cap  106   c  portion of the air spring housing  106 . In this regard, the solenoid valve chamber has a sidewall  124  which depends from the cap head  138  of the cap  106   c  interiorly with respect to the air spring  104 , and terminates at a sidewall orifice  124   a . The chamber cover  118  removably attaches to the solenoid valve chamber  116  at the sidewall orifice  124   a . An example of a removable attachment modality (shown at  FIG. 3 ) is via the chamber cover having a peripheral lip  118   a  having an internally disposed notch  120  which snappingly interfaces with a peripheral barb  122  of the sidewall  124 ; or another removable attachment modality may be used, as for example by threading or by threaded fasteners. 
     An air line fitting  126  is externally disposed in the cap  106   c  such that the air line fitting communicates with the solenoid valve chamber  116 . The chamber cover  118  includes an air passage opening  128  which communicates with the solenoid valve chamber  116  when the chamber cover is attached to the sidewall  124  of the solenoid valve chamber. An electrical connector  130  is disposed externally with respect to the cap  106   c  adjacent the solenoid valve chamber  116 , wherein an electrical connection can be made therefrom into the solenoid valve chamber. 
     A solenoid valve  132  is disposed in the solenoid valve receptacle  114 , as may be more particularly understood by additional reference to  FIGS. 3 and 4 , which shows a nonlimiting exemplification thereof. 
     A first air passage  140  of the solenoid valve  132  is sealingly interfaced with the air line fitting  126 , as for example by a press-fit. Electrical leads  136  extend between the electrical connector  130  and the solenoid valve  132  and provide an electrical connection therebetween. 
     A second air passage  142  of the solenoid valve  132  passes through the air passage opening  128  of the chamber cover  118 . The shell  144  of the solenoid valve  132  and the second air passage  142  are sealed with respect to the chamber cover  118  at the second air passage  142  via an elastomeric O-ring  146 . 
     As can be discerned from  FIGS. 3 and 4 , the solenoid valve has a generally conventional construction, wherein an armature  150  biased by a return spring  152  is selectively retracted from an air metering valve seat  154  via a solenoid  156 . 
     In assembly of the integrated solenoid valve and leveling device  100 , the air spring  104  is opened by the bellows  108  being unclamped at the annular  112  of the cap  106   c . The chamber cover  118  is snapped off from the sidewall  124  of the solenoid valve chamber. A solenoid valve  132  is placed into the solenoid valve chamber, wherein the first air passage  140  is interfaced with the air line fitting  126 . Electrical connection of an electrical lead  166  (see  FIG. 3 ) is made to the electrical connector  130  and, thereby, to the solenoid valve  132 . An air line  168  (see  FIG. 3 ) is connected to the air fitting  126 . The chamber cover is snapped back onto the sidewall of the solenoid valve chamber, wherein the second air passage  142  projects, in sealing relation via the O-ring  146  to the solenoid valve chamber, through the air passage opening  128  of the chamber cover. The bellows is again clamped to the annular land of the cap. An electrical plug of an air suspension system (as for example the system  10 ) is interfaced with the electrical connector. An air line is connected to the air line fitting. 
     In operation of the integrated solenoid valve and leveling device  100 , in response to electrical signals from the air suspension system, the solenoid valve regulates the air pressure within the air spring and the motor vehicle is provided with an air suspension via flexing of the bellows. Should an untoward event occur to the air line, such as for example a cut or break wherein pressure is lost, the air valve will nonetheless independently maintain pressure within the air spring. 
     Referring now to  FIG. 5 , a second embodiment of the integrated solenoid valve and leveling device  100   b  is depicted. Now the air spring  104 ′ includes a solenoid valve receptacle  114 ′ which is integrally formed with the piston floor  160  of the piston  106   p ′ of an air spring  104 ′. The construction of the solenoid valve receptacle  114 ′ is as described hereinabove with respect to  FIGS. 2 through 4 , so that further description is obviated, wherein like parts have like numeral designations with primes. A solenoid valve  132 ′ is disposed within the solenoid valve chamber and interfaces as hereinabove described with respect to each of the air line fitting  126 ′, the electrical connector  130 ′ and the air passage opening  128 ′. Operation is as described hereinabove. 
     Referring now to  FIG. 6 , a third embodiment of the integrated solenoid valve and leveling device  100   c  is depicted. Now the air spring  104 ″ includes a solenoid valve receptacle  114 ″ which is integrally formed with the piston wall  162  of the piston  106   p ″ of an air spring  104 ″. The construction of the solenoid valve receptacle  114 ″ is as described hereinabove with respect to  FIGS. 2 through 4 , so that further description is obviated, wherein like parts have like numeral designations with double primes. A solenoid valve  132 ″ is disposed within the solenoid valve chamber and interfaces as hereinabove described with respect to each of the air line fitting  126 ″, the electrical connector  130 ″ and the air passage opening  128 ″. Operation is as described hereinabove. 
     Referring now to  FIG. 7 , a fourth embodiment of the integrated solenoid valve and leveling device  100   d  is depicted. The air spring  104 ′″ has a cap  106   c ′″ which includes a cap wall  164  extending between the head  138 ′″ and the annular land  112 ′″. Now the solenoid valve receptacle  114 ′″ is integrally formed with the cap wall  164  of the cap  106   c ′″ of an air spring  104 ′″. The construction of the solenoid valve receptacle  114 ′ is as described hereinabove with respect to  FIGS. 2 through 4 , so that further description is obviated, wherein like parts have like numeral designations with triple primes. A solenoid valve  132 ′″ is disposed within the solenoid valve chamber and interfaces as hereinabove described with respect to each of the air line fitting  126 ′″, the electrical connector  130 ′″ and the air passage opening  128 ′″. Operation is as described hereinabove. 
     To those skilled in the art to which this invention appertains, the above described preferred embodiment may be subject to change or modification. For example, as mentioned hereinabove, a solenoid valve housed within a solenoid receptacle may be adapted according to the teachings hereinabove to any air operated leveling devices, including an air spring, air spring over damper (shock absorber) module, air spring over strut module, jounce bumper, etc. 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.