Air management system for a vehicle

Abstract

An air management system for a vehicle having a vehicle body and a plurality of wheels, comprising a reservoir tank for storing compressed air and for filling at least one air spring of the vehicle, and a compressed air supply unit for supplying compressed air. The compressed air supply unit comprises a compressed air port leading to the reservoir tank and to the at least one air spring, a discharge port leading to the ambient environment, and a pilot discharge valve connected to the compressed air port and configured to discharge the at least one air spring through the discharge port, the pilot discharge valve having a pilot control port. The reservoir tank is pneumatically connected to the pilot control port of the pilot discharge valve and is configured to provide the pilot control port with an opening pilot discharge valve control pressure during discharging the at least one air spring.

Description

[0001] Cross Reference to Related Applications

[0002] This disclosure claims priority to U.S. Provisional Application No. 63 / 549,901, filed February 5, 2024, the entire contents of which are incorporated herein by reference. TECHNICAL FIELD

[0003] The present disclosure relates generally to an air management system for a vehicle. BACKGROUND

[0004] Air suspension assemblies are known in the art and can be used in various vehicles including automobiles. Air suspension assemblies generally include a plurality of air springs, each of which is used to interconnect a vehicle body of a motor vehicle with one of the vehicle wheels to dampen relative forces between the vehicle body and the vehicle wheels and to adjust the height of the motor vehicle. One example of such an air suspension assembly is disclosed in U.S. Patent No. 5,465,209 to Sammut et al. The air suspension assembly includes a compressor for inflating the air springs and a plurality of valves disposed between the compressor and the air springs and controlled by a controller for regulating the flow of air from the compressor to the air springs.

[0005] Known air management systems can be relatively expensive, bulky and complex in design. Therefore, there remains a need for low cost improvements to such air management systems. SUMMARY

[0006] The present disclosure provides, in its broadest aspects, an air management system for a vehicle.

[0007] The present disclosure provides an air management system for a vehicle having a vehicle body and a plurality of vehicle wheels, the air management system comprising a reservoir tank for storing compressed air and for filling at least one air spring of the vehicle, and a compressed air supply unit for supplying compressed air. The compressed air supply unit comprises a compressed air port leading to the reservoir tank and to the at least one air spring, a discharge port leading to the ambient environment, and a pilot discharge valve. The pilot discharge valve is connected to the compressed air port and is configured to discharge the at least one air spring through the discharge port, the pilot discharge valve having a pilot control port. The reservoir tank is pneumatically connected to the pilot control port of the pilot discharge valve and is configured to provide the pilot control port with a control pressure for opening the pilot discharge valve during discharging the at least one air spring.

[0008] In an embodiment, the compressed air supply unit further comprises an exhaust valve connected to the pilot control port, and the reservoir tank is pneumatically connected to the pilot control port of the pilot discharge valve via the exhaust valve and selectively loads the pilot control port with pressure through the exhaust valve.

[0009] In an embodiment, the compressed air supply unit defines a reservoir port, the reservoir tank is pneumatically connected to the reservoir port by a reservoir air line, and the reservoir port is pneumatically connected to the control port of the exhaust valve by a pressure delivery line.

[0010] In an embodiment, the air management system further includes a manifold block pneumatically connected to at least one of the air springs, the compressed air port, and the reservoir tank; and the reservoir tank is pneumatically connected to the control port of the exhaust valve via the manifold block.

[0011] In an embodiment, the manifold block includes a boost valve and defines a boost outlet port, the compressed air supply unit defines a boost inlet port, and the reservoir tank is pneumatically connected to the control port of the exhaust valve via the boost valve, the boost outlet port, and the boost inlet port.

[0012] In an embodiment, the compressed air supply unit defines a non-boost inlet port, the manifold block defines a non-boost outlet port, and the reservoir tank is pneumatically connected to the control port of the exhaust valve via the non-boost outlet port and the non-boost inlet port.

[0013] In an embodiment, the manifold block includes a bleed control valve and defines a first bleed port; and the compressed air supply unit defines a second bleed port, and the reservoir tank is pneumatically connected to the control port of the exhaust valve via the bleed control valve, the first bleed port, and the second bleed port.

[0014] In an embodiment, the compressed air supply unit further includes an exhaust valve connected to a pilot bleed valve, and the reservoir tank is pneumatically connected to a pilot control port of the pilot bleed valve independent of the exhaust valve.

[0015] In an embodiment, the air management system further includes a manifold block pneumatically connected to at least one of the air springs, the compressed air port, and the reservoir tank; and the reservoir tank is pneumatically connected to a pilot control port of the pilot bleed valve via the manifold block independent of the exhaust valve.

[0016] In an embodiment, the manifold block includes a boost valve and defines a boost outlet port, the compressed air supply unit defines a boost inlet port, and the reservoir tank is pneumatically connected to a pilot control port of the pilot bleed valve via the boost valve, the boost outlet port, and the boost inlet port independent of the exhaust valve.

[0017] In an embodiment, the exhaust valve is a two-position, three-way valve, the control port of which is plugged; or the exhaust valve is a two-position, two-way valve.

[0018] In an embodiment, the compressed air supply unit further includes a compressor having at least one compressor stage, and a compressed air main line between the compressor and the compressed air port. The compressor is configured to provide compressed air to the reservoir tank, and a pilot discharge valve is disposed on the compressed air main line. The reservoir tank is configured to provide a control pressure to the pilot control port that is higher than a pressure in the compressed air main line during discharge of the at least one air spring independent of the pressure in the compressed air main line.

[0019] In an embodiment, the air management system further includes a central air line, at least one spring air line, and at least one suspension valve. The central air line is disposed between the at least one air spring and the compressed air port, and fluidly connected to the at least one air spring and the compressed air port. The spring air line extends between the central air line and the at least one air spring. The suspension valve is disposed along the at least one spring air line for selectively allowing and preventing flow of air between the at least one air spring and the central air line.

[0020] In an embodiment, the air management system further includes a reservoir air line, a first reservoir valve, and a second reservoir valve. The reservoir air line extends between the reservoir tank and the central air line. The first reservoir valve and the second reservoir valve are disposed along the reservoir air line, each of the first and second reservoir valves having an orifice that allows passage of air, and each of the first and second reservoir valves selectively allowing passage of air through the reservoir valve between the reservoir tank and the central air line.

[0021] In an embodiment, the compressed air supply unit includes a compressor having at least one compressor stage and configured to provide compressed air to the reservoir tank, and the compressed air supply unit defines a boost inlet port. The air management system further includes a boost valve between the reservoir air line and a boost air line connected to the boost inlet port for allowing passage of air from the reservoir tank to the compressor or the pilot control port via the boost inlet port.

[0022] In an embodiment, the air management system further includes an electronic control unit and a pressure sensor. The electronic control unit is electrically connected to each of the at least one suspension valve, the first reservoir valve, and the second reservoir valve to selectively open and close each of them. The pressure sensor is electrically coupled to the electronic control unit and connected to the central air line for reading a pressure of the at least one air spring.

[0023] In an embodiment, the air management system further comprises a dryer and a dryer isolation valve. The dryer is disposed within the compressed air supply unit and coupled to the compressed air port for reducing moisture in the air before the air supplied by the compressed air supply unit enters the reservoir tank and the at least one air spring. The dryer isolation valve is disposed in series with the compressed air port for allowing the central air line to be isolated from the dryer.

[0024] In an embodiment, the reservoir tank is an external tank located outside the compressed air supply unit and has a volume of 7 to 16 liters.

[0025] Embodiments of the present disclosure enable lower exhaust air pressure in a more cost-effective, more compact and simplified solution. BRIEF DESCRIPTION OF DRAWINGS

[0026] The advantages of the present disclosure will be readily appreciated as the same becomes better understood by reference to the following detailed description when considered in connection with the accompanying drawings wherein:

[0027] Figure 1 is a schematic diagram of an air management system according to a first exemplary embodiment of the present disclosure;

[0028] Figure 2 is Figure 1 a schematic diagram of the pilot exhaust valve and the exhaust valve of

[0029] Figure 3 is Figure 1 a schematic diagram of the pilot exhaust valve and the exhaust valve of

[0030] Figure 4 is a schematic diagram of an air management system according to a second exemplary embodiment of the present disclosure;

[0031] Figure 5 is a schematic diagram of an air management system according to a third exemplary embodiment of the present disclosure;

[0032] Figure 6 is a schematic diagram of an air management system according to a fourth exemplary embodiment of the present disclosure;

[0033] Figure 7 is a schematic diagram of an air management system according to a fifth exemplary embodiment of the present disclosure;

[0034] Figure 8 is a schematic diagram of an air management system according to a sixth exemplary embodiment of the present disclosure. DETAILED DESCRIPTION

[0035] The present disclosure will be described in detail with reference to the following embodiments.

[0036] Referring to the accompanying drawings, air management systems 20, 120, 220, 320, 420, and 520 are generally shown for controlling air suspension assemblies of vehicles having a body and wheels. In exemplary embodiments, the described air management systems 20, 120, 220, 320, 420, and 520 are depicted for use on motor vehicles with four wheels; however, it should be understood that the air management systems can be used on other vehicles with any number of wheels, including but not limited to motorcycles and all-terrain vehicles.

[0037] As in Figure 1 and Figures 4-8 As best shown, the air management systems 20, 120, 220, 320, 420, and 520 are connected to four air springs 22. Each of the air springs 22 interconnects one of the vehicle's body and one of the wheels, used to dampen the relative forces between the vehicle's body and the wheels and to raise and lower the vehicle to a desired height.

[0038] Figure 1 This is a schematic diagram of an air management system 20 according to a first exemplary embodiment of the present disclosure. Figure 2 yes Figure 1 A schematic diagram of the pilot discharge valve and exhaust valve, showing the pilot discharge valve in the closed state. Figure 3 yes Figure 1 A schematic diagram of the pilot exhaust valve and the exhaust valve, showing the pilot exhaust valve in the open state.

[0039] like Figure 1 As shown in the embodiment, the air management system 20 includes: a compressed air supply unit, which may be a compressor assembly 21 for supplying compressed air; a storage tank 38 for storing compressed air and filling air springs 22; and an intelligent air management module (IAMM), which may be an electro-pneumatic control unit (EPCU) 26 for controlling the raising and lowering of the vehicle.

[0040] The EPCU 26 includes a manifold block 27 having a plurality of valves 30, 32, 34, 36, 39 for controlling how the air springs 22 are filled and evacuated. The EPCU 26 also includes an Electronic Control Unit (ECU) 44 electrically connected to each of the valves 30, 32, 34, 36, 39 for selectively opening and closing each of them to control the air management system 20 to fill or evacuate the air springs 22. The air management system 20 can or can not include the air springs 22.

[0041] The height change capability of the air management system 20 can be used to perform functions such as maintaining the vehicle ride height due to load changes, lowering the vehicle speed to provide improved fuel economy, lowering the vehicle to allow easy ingress and egress from the vehicle, and adjusting the height of respective sides of the vehicle to compensate for side-to-side load changes of the vehicle.

[0042] The compressor assembly 24 includes the compressor 21 and defines an air inlet 46 for receiving air into the compressor 21. The compressor assembly 24 also defines a compressed air port 50 for fluidly connecting the compressor 21 with the reservoir tank 38 and the manifold block 26 and providing air to the reservoir tank 38 and the manifold block 27. The compressor 21 includes a motor 211 for drawing air through the air inlet 46. In the current case, the compressor 21 has a low pressure stage 212 and a high pressure stage 213 that are pneumatically connected to each other via an intermediate line 243, such that compressed air that is drawn in by the air inlet 46 and pre-compressed in the low pressure stage 212 can flow into the high pressure stage 213 and be further compressed there to a high pressure level for providing to the compressed air port 50.

[0043] The compressor assembly 24 also defines a bleed port 52 for releasing air from the air springs 22. Exemplarily, a muffler or silencer 28 is provided to define the bleed port 52 and reduce noise, such that the air leaving the system is quieter.

[0044] The compressor assembly 24 also includes a compressed air main line 41 between the compressor 21 and the compressed air port 50, and a Piloted Exhaust Valve (PEV) 11 arranged on the compressed air main line 41. The piloted exhaust valve 11 is connected to the bleed port 52 and can provide a much larger opening path for fast venting during the evacuation of the air springs 22 compared to a typical pneumatic solenoid valve with a 1.4 mm diameter orifice commonly used.

[0045] In particular, as Figure 2As shown, the pilot dump valve 11 is a pneumatic actuated valve and comprises a valve body 111, a spool 112 slidably disposed within the valve body 111, and a spring 113 disposed within the valve body 111 and abutting the spool 112. The valve body 111 defines a pilot control port 114, a first pneumatic port 115, a second pneumatic port 116, and a third pneumatic port 117. The reservoir tank 38 is pneumatically connected to the pilot control port 114. The first pneumatic port 115 is connected to the air main line 41, and the second pneumatic port 116 is connected to the dump port 52. The first pneumatic port 115 has a diameter of, for example, 6 mm, which is much larger than the diameter of a typical pneumatic solenoid valve. As shown, the spool 112 is configured as a large stepped piston, such that the control pressure from the reservoir tank 38 can act on the back of the stepped piston via the pilot control port 114 to move the spool 112 away from the first pneumatic port 115, thereby establishing a larger open path between the air main line 41 and the dump port 52 for rapid dumping of the air spring 22. As a result, the vehicle can be lowered in a very short time. Figure 2 As shown, the pilot dump valve 11 is normally closed, as the spool 112 cuts off the fluid communication between the first pneumatic port 115 and the second pneumatic port 116 under the force of the spring 113. To overcome the spring force, as shown Figure 3 As shown, the spool 112 is configured as a large stepped piston, such that the control pressure from the reservoir tank 38 can act on the back of the stepped piston via the pilot control port 114 to move the spool 112 away from the first pneumatic port 115, thereby establishing a larger open path between the air main line 41 and the dump port 52 for rapid dumping of the air spring 22. As a result, the vehicle can be lowered in a very short time.

[0046] The reservoir tank 38 is a large reservoir typically used in most air management systems for filling air springs and located outside the compressor assembly, the reservoir tank 38 is configured to directly provide control pressure to the pilot control port 114. The term “directly provide” is to be understood as providing control pressure without directing it through any additional accumulator. The reservoir tank 38 can have a volume of about 7 to 16 liters. It should be understood that the pressure in the large reservoir tank 38 is almost always much higher than the exhaust system pressure (e.g. the pressure in the compressed air main line 41). This means that the reservoir tank 38 is able to continuously provide such a high control pressure to the pilot control port 114, allowing the pilot dump valve 11 to remain open for a longer time, thereby achieving a lower exhaust pressure. This direct configuration eliminates the need for a separate pilot pressure accumulator (which in conventional systems is connected to the large reservoir tank via an accumulator check valve to capture the high pressure for actuating the pilot dump valve 11), thereby providing a more cost-effective, more compact and simpler solution.

[0047] The compressor assembly 24 further comprises an exhaust valve 29 pneumatically connecting the reservoir tank 38 to the pilot control port 114 of the pilot dump valve 11, such that the reservoir tank 38 can selectively pressurize the pilot control port 114 via the exhaust valve 29. The exhaust valve 29 is further connected to the third pneumatic port 117 of the pilot dump valve 11.

[0048] Exhaust valve 29 can be configured as a two-position, three-way solenoid valve having Figure 2 the de-energized closed state shown, exhaust valve 29 is used to establish fluid communication between pilot control port 114 and third pneumatic port 117 such that when no control pressure is input to pilot control port 114, the front and back sides of spool 112 are at equal pressure. When energized, exhaust valve 29 transitions from the de-energized closed state to the energized open state shown, in which exhaust valve 29 is used to establish fluid communication between reservoir tank 38 and pilot control port 114 for venting. Figure 3

[0049] Referring to Figure 1 , compressor assembly 24 defines a reservoir port 51 that is connected to reservoir tank 38 through a reservoir air line 66 and to a control port 291 of exhaust valve 29 through a pressure delivery line 53, thereby allowing air from reservoir tank 38 to flow through reservoir air line 66 into reservoir port 51, then through pressure delivery line 53 into control port 291 of exhaust valve 29, and finally be directed to pilot control port 114 through pilot valve line 55, in sequence.

[0050] Referring to Figure 1 , compressor assembly 24 includes a dryer 40 coupled to compressed air port 50 for reducing moisture in the air supplied by compressor 21 before entering reservoir tank 38 and air spring 22. Dryer 40 is disposed on compressed air main line 41 between pilot exhaust valve 11 and compressed air port 50. For example, dryer 40 typically includes a desiccant disposed therein for absorbing excess moisture in the system, such as delivered through compressed air main line 41. As air travels away from compressor 21 through dryer 40, the moisture content of the desiccant increases; as air passes through dryer 40 and out exhaust port 52, the moisture content of the desiccant decreases. Additional control valves in compressor assembly 24 can be utilized to direct flow.

[0051] Manifold block 27 fluidly connects air spring 22, compressor 21, dryer 40, and reservoir tank 38. Manifold block 27 defines a compressor inlet port 54, which can include a cover for protecting compressor inlet port 54 when not in use. A base air line 56 extends between compressed air port 50 and compressor inlet port 54 of manifold block 27 for delivering air between manifold block 27 and compressor assembly 24. Additionally, a central air line 63 is disposed inside manifold block 27 and connected to compressor inlet port 54 such that central air line 63 is fluidly connected to base air line 56.

[0052] ​The manifold block 27 also defines four suspension ports 58, each of which is fluidly connected to the central air line 63. Each of the plurality of spring air lines 60 extends between the central air line 63 and one of the air springs 22. Each of the spring air lines 60 includes a first portion disposed inside the manifold block 27 and extending from the central air line 63 to a suspension port 58, and a second portion disposed outside the manifold block 27 and extending from the suspension port 58 to one of the air springs 22.

[0053] The manifold block 27 also includes a plurality of suspension valves 30, each of which is disposed along one of the spring air lines 60 for blocking and allowing passage of air between the manifold block 27 and the respective air spring 22. Each of the suspension valves 30 is electrically connected with the electronic control unit 44 for selective movement between an open position and a closed position. More specifically, each suspension valve 30 allows passage of air between the air spring 22 and the central air line 63 when in the open position, and each suspension valve 30 blocks passage of air between the air spring 22 and the central air line 63 when in the closed position.

[0054] The reservoir tank 38 stores compressed air from the compressor assembly 24 for distribution to the air springs 22. Due to the stored energy of the compressed air in the reservoir tank 38, the air management system 20 is able to independently adjust the height of each wheel and can raise the vehicle more quickly than would be possible without the reservoir tank 38. The manifold block 27 defines a reservoir port 64 fluidly connected to the central air line 63. A portion of a reservoir tank air line 66 extends from the reservoir tank 38 to the central air line 63 for transporting air between the manifold block 27 and the reservoir tank 38. The reservoir air line 66 includes an inner segment inside the manifold block 27 between the central air line 63 and the reservoir port 64, and an outer segment disposed outside the manifold block 27 between the reservoir tank 38 and the reservoir port 64 and the reservoir port 51.

[0055] The manifold block 27 also includes a first reservoir valve 32 and a second reservoir valve 34, each of which is disposed in-line with the reservoir port 64 inside the manifold block 26 along the reservoir air line 66 for selectively blocking and allowing passage of air between the manifold block 26 and the reservoir tank 38. Each of the first reservoir valve 32 and the second reservoir valve 34 is electrically connected with the electronic control unit 44 for selectively opening and closing the first reservoir valve 32 and the second reservoir valve 34.

[0056] The first memory valve 32 and the second memory valve 34 are positioned in parallel, thereby allowing one or both of the first memory valve 32 and the second memory valve 34 to close at any given time. More specifically, the memory air line 66 branches into a first branch 69 and a second branch 74, and rejoins along a portion of the memory air line 66 that connects to the central air line 63. The first memory valve 32 is disposed along the first branch 69 and the second memory valve 34 is disposed along the second branch 74.

[0057] Each of the memory valves 32 and 34 includes an orifice through which air can pass. The orifice of the first memory valve 32 is smaller than that of the second memory valve 34. The orifice sizes of the memory valves 32 and 34 can be varied to provide different flow rates between the memory tank 38 and the manifold block 26. Because of the presence of this pair of memory valves 32 and 34, three different flow rates of air delivered through the memory valves 32 and 34 are possible: 1) maximum flow rate – when the first memory valve 32 and the second memory valve 34 are open; 2) half flow rate of the first memory valve 32 – when the first memory valve 32 is open and the other is closed; and 3) half flow rate of the second memory valve 34 – when the second memory valve 34 is open and the other is closed. It should be understood that under certain operating conditions, it may be necessary to utilize different air flow rates into the air spring 22 to fill the air spring 22 at a faster or slower rate.

[0058] like Figure 1 As shown, manifold 27 includes a booster valve 39 disposed within an inner section of the storage air line 66 and defining a booster outlet port 65. Compressor assembly 24 defines a booster inlet port 81, and a booster air line 83 extends between the booster outlet port 65 and the booster inlet port 81. The booster valve 39 is pneumatically connected to the booster air line 83 for selectively connecting directly to the storage tank 38 and the compressor 21. The booster valve 39 may be electrically connected to an electronic control unit 44 for selectively opening and closing the booster valve 39. It should be understood that the booster valve 39 can be used to reduce the starting torque of the compressor assembly 24 without purging manifold 27. The booster valve 39 can provide additional air pressure to the interstages of the compressor 21 through the booster inlet port 81 to increase flow output and thus accelerate the vehicle more quickly.

[0059] A pressure sensor 42 is provided in the manifold block 27 for measuring pressure in the compressor assembly 24, the reservoir tank 38, and / or the air springs 22. To obtain a separate reading for each of the air springs 22 or the reservoir tank 38, the manifold block 27 is vented and then the valve 30, 32, 34 for the in question device is immediately opened so that the pressure corresponding to the in question device can be measured. Thus, it should be understood that the pressure sensor 42 can be used to verify that the compressor assembly 24, the reservoir tank 38, and the valves 30, 32, 34 are functioning properly.

[0060] The dryer isolation valve 36 is provided in series with the compressor inlet 54. The dryer control valve 36 is electrically connected to the electronic control unit 44 to selectively open and close the dryer control valve 36. In most cases, the dryer control valve 36 remains closed except for venting, to allow for one-way flow from the compressor 24 to the manifold block 27 via a slight spring valve seat. Thus, when individual pressure readings for any combination of the reservoir tank 38 or air springs 22 are needed, the dryer control valve 36 isolates the dryer volume from the manifold block 27. Since the manifold block 27 is primarily composed of small drilled holes connecting components together, there is very little air volume exposed to the pressure sensor 42 compared to the volumes of the manifold block 27, the dryer 40, and the base air line 56 with the dryer isolation valve 36 closed. This allows the pressure reading for a particular device to stabilize almost instantaneously and with very little air volume loss, thus making the reading faster and more efficient. As such, implementing the dryer isolation valve 36 improves the speed and efficiency of obtaining pressure readings.

[0061] Figure 4 is a schematic diagram of an air management system 120 according to a second exemplary embodiment of the present disclosure. Figure 4 The air management system 120 shown in Figure 1 differs from the system 20 shown in Figure 4 Specifically, as shown in Figure 1 the reservoir tank port 51 is eliminated. As shown in Figure 1 the pressure delivery line 53 shown in

[0062] In the case of a vehicle with a single compressor 21, the air management system 120 shown in Figure 4In the illustrated design, the pressure of the reservoir tank 38 is directed through the existing boost outlet port 65 and boost inlet port 81. This design allows air from the reservoir tank 38 to pass through the reservoir air line 66 into the reservoir port 64, then into the boost valve 39, through the boost air line 83 into the boost inlet port 81, through the pressure delivery line 53 into the control port 291 of the exhaust valve 29, and finally directed to the pilot control port 114 of the pilot exhaust valve 11. Since the reservoir pressure (i.e., the pressure from the reservoir tank 38) is almost always higher than the exhaust system pressure, this design also allows the pilot exhaust valve 11 to remain open longer to achieve lower exhaust pressures.

[0063] Figure 5 is a schematic of an air management system 220 according to a third exemplary embodiment of the present disclosure. Figure 5 The air management system 220 illustrated is similar to the system 20, 120, 220 illustrated in Figure 4 A significant difference between the system 120 illustrated and the system 20, 220 illustrated is the elimination of the boost valve 39, thereby saving cost. In this design, as Figure 3 As a result of the elimination of the boost valve 39, the boost air line 83 can more accurately be referred to as a non-boost air line, the boost inlet port 81 can be referred to as a non-boost inlet port, and the boost outlet port 65 can be referred to as a non-boost outlet port, as illustrated. The non-boost air line is partially located inside the manifold block 27. It should be understood that the term "non-boost" refers to the non-boost air line, non-boost inlet port, and non-boost outlet port not being associated with, e.g., not connected to, a boost valve. This design eliminates the boost function of the compressor 21, as this function is not always needed in every system.

[0064] Figure 6 is a schematic of an air management system 320 according to a fourth exemplary embodiment of the present disclosure. Figure 4 The air management system 320 illustrated is similar to the system 20, 120, 220 illustrated in Figure 1 , Figure 4 and Figure 5 A significant difference between the system 20, 120, 220 illustrated and the system 320 illustrated is the path from the reservoir tank 38 to the pilot control port 114 of the pilot exhaust valve 11. Specifically, the reservoir tank 38 is pneumatically connected to the pilot control port 114 of the pilot exhaust valve 11 independent of the exhaust valve 29. In other words, air from the reservoir tank 38 does not pass through the exhaust valve 29. In particular, Figure 2 The pressure delivery line 53 illustrated is changed to connect the boost inlet port 81 directly to the pilot control port 114 of the pilot exhaust valve 11.

[0065] This design allows air from the reservoir tank 38 to pass through the reservoir air line 66 into the reservoir port 64, then into the boost valve 39, through the boost air line 83 into the boost inlet port 81, and via the pressure delivery line 53 into the pilot control port 114, without passing through the exhaust valve 29. As a result, the high pressure from the reservoir tank 38 can keep the pilot exhaust valve 11 open for a longer period of time to achieve a lower exhaust pressure.

[0066] In this design, the boost valve 39 can be a two-way blocker valve that can activate the pilot exhaust valve 11 to the open position when energized (i.e., the boost valve 39 is open). To return the pilot exhaust valve 11 to its closed position, the boost valve 39 is de-energized, and the exhaust valve 29 is energized to exhaust the air pressure used to activate the pilot exhaust valve 11.

[0067] In this design, as shown in Figure 6 , the boost function of the compressor assembly 24 is also eliminated, and the boost valve 39 is needed to control the application of reservoir air pressure to the pilot exhaust valve 11. At the same time, or preferably slightly earlier, the exhaust valve 29 must be energized to further prevent the reservoir pressure from escaping. In the same manner as the system shown in Figure 1 , Figure 4 , and Figure 5 , the exhaust valve 29 can be configured as a two-way, three-port solenoid valve, but with the difference that in this design the control port 291 of the exhaust valve 29 is blocked.

[0068] Figure 7 is a schematic diagram of an air management system 420 according to a fifth exemplary embodiment of the present disclosure. Figure 7 The air management system 420 shown in Figure 6 is significantly different from the system 320 shown in , in that the exhaust valve 29 is changed from a two-way, three-port solenoid valve to a lower cost two-way, two-port solenoid valve. In this design, the exhaust valve 29 can be configured as two two-way, two-port solenoid valves acting in series, i.e., the exhaust valve 29 and the boost valve 39.

[0069] Figure 8 is a schematic diagram of an air management system 520 according to a sixth exemplary embodiment of the present disclosure. Figure 8 The air management system 520 shown in Figure 1 is significantly different from the system 20 shown in Figure 8 , in that the path from the reservoir tank 38 to the control port 291 of the exhaust valve 29. Specifically, as shown in Figure 1 , a first exhaust port 68 and an exhaust control valve 71 are added to the manifold block 27, and, a second exhaust port 62 is added to the compressor assembly 24 in place ofThe storage port 51 is shown. The second vent port 62 is connected to the first vent port 68 through the external air line 72. In the same way as the system shown in Figure 1 The outer section of the storage air line 66, which is disposed outside the manifold block 27, is between the storage tank 38 and the storage port 64 in the same way as the system shown. Figure 1 The inner section of the storage air line 66, which is disposed inside the manifold block 27, is provided with the first storage valve 32 and the second storage valve 34 in a different way than the system shown. The vent control valve 71 is also provided. The vent control valve 71 is configured to selectively control the flow of air between the storage air line 66 and the normally closed control port 291 of the vent valve 29. In addition, the vent control valve 71 makes the design more reliable because it prevents pressure loss if the external air line 72 leaks. The vent control valve 71 and the vent valve 29 need to work in coordination to initiate the venting cycle.

[0070] In this design, as shown in Figure 8 The pressure of the storage tank 38 is directed through the storage port 64, the first vent port 68, and the second vent port 62 in this design. This design allows air from the storage tank 38 to pass through the storage air line 66 into the storage port 64, then into the vent control valve 71, through the first vent port 68 and the external air line 72 into the second vent port 62, via the pressure delivery line 53 into the control port 291 of the vent valve 29, and finally directed to the pilot control port 114 of the pilot vent valve 11. Since the storage pressure is almost always higher than the vent system pressure, this design can also keep the pilot vent valve 11 open for a longer time to achieve a lower venting pressure.

[0071] The foregoing description is not intended to be exhaustive or to limit the disclosure to the precise embodiments disclosed. Various elements or features of a particular embodiment are generally not limited to that particular embodiment, but are interchangeable with other embodiments, as applicable, and can be used in a selected embodiment, even if not specifically shown or described. It can also vary in many ways. Such variations should not be regarded as a departure from the disclosure, and all such modifications are intended to be included within the scope of the disclosure.

Claims

1. An air management system for a vehicle having a vehicle body and a plurality of wheels, the air management system comprising: a reservoir tank for storing compressed air and for charging at least one air spring of the vehicle; a compressed air supply unit for supplying the compressed air, the compressed air supply unit comprising: a compressed air port to the reservoir tank and to the at least one air spring; a vent port to an ambient environment; and a pilot vent valve connected to the compressed air port and configured to vent the at least one air spring through the vent port, the pilot vent valve having a pilot control port; a central air line disposed between the at least one air spring and the compressed air port and fluidly connected to the at least one air spring and the compressed air port; at least one spring air line extending between the central air line and the at least one air spring; and at least one suspension valve disposed along the at least one spring air line for selectively allowing and preventing air flow between the at least one air spring and the central air line; wherein the reservoir tank is pneumatically connected to the pilot control port of the pilot vent valve and is configured to provide the pilot control port with a control pressure for opening the pilot vent valve during venting of the at least one air spring.

2. The air management system of claim 1, wherein, the compressed air supply unit further comprises an exhaust valve connected to the pilot control port, and the reservoir tank is pneumatically connected to the pilot control port of the pilot vent valve via the exhaust valve and selectively loaded to pressure on the pilot control port through the exhaust valve.

3. The air management system of claim 2, wherein, the compressed air supply unit defines a reservoir port, the reservoir tank is pneumatically connected to the reservoir port by a reservoir air line, and the reservoir port is pneumatically connected to a control port of the exhaust valve by a pressure transfer line.

4. The air management system of claim 2, wherein, the air management system further comprises a manifold block pneumatically connecting the at least one air spring, the compressed air port, and the reservoir tank; and the reservoir tank is pneumatically connected to the control port of the exhaust valve via the manifold block.

5. The air management system of claim 4, wherein, the manifold block comprises a boost valve and defines a boost outlet port, the compressed air supply unit defines a boost inlet port, and the reservoir tank is pneumatically connected to the control port of the exhaust valve via the boost valve, the boost outlet port, and the boost inlet port.

6. The air management system of claim 4, wherein, the compressed air supply unit defines a non-boost inlet port, the manifold block defines a non-boost outlet port, and the reservoir tank is pneumatically connected to the control port of the exhaust valve via the non-boost outlet port and the non-boost inlet port.

7. The air management system of claim 4, wherein, the manifold block comprises a vent control valve and defines a first vent port; and the compressed air supply unit defines a second vent port, and the reservoir tank is pneumatically connected to the control port of the exhaust valve via the vent control valve, the first vent port, and the second vent port.

8. The air management system of claim 1, wherein, The compressed air supply unit further includes an exhaust valve connected to the pilot exhaust valve, and the reservoir tank is pneumatically connected to a pilot control port of the pilot exhaust valve independent of the exhaust valve.

9. The air management system of claim 8, wherein, The air management system further includes a manifold block pneumatically connecting the at least one air spring, the compressed air port, and the reservoir tank; and The reservoir tank is pneumatically connected to a pilot control port of the pilot exhaust valve via the manifold block independent of the exhaust valve.

10. The air management system of claim 9, wherein, The manifold block includes a boost valve and defines a boost outlet port, the compressed air supply unit defines a boost inlet port, and the reservoir tank is pneumatically connected to a pilot control port of the pilot exhaust valve via the boost valve, the boost outlet port, and the boost inlet port independent of the exhaust valve.

11. The air management system of claim 8, wherein, The exhaust valve is a two-position, three-way valve having a control port that is plugged; or The exhaust valve is a two-position, two-way valve.

12. The air management system of claim 1, wherein, The compressed air supply unit further includes: a compressor having at least one compressor stage for providing compressed air to the reservoir tank; a compressed air main line between the compressor and the compressed air port, the pilot exhaust valve being disposed on the compressed air main line; wherein the reservoir tank is configured to provide a control pressure to the pilot control port that is higher than a pressure in the compressed air main line independent of the pressure in the compressed air main line during discharge of the at least one air spring.

13. The air management system of claim 1, further comprising: a reservoir air line extending between the reservoir tank and the central air line; and first and second reservoir valves disposed along the reservoir air line, each of the first and second reservoir valves having an orifice that allows air to pass therethrough, and each of the first and second reservoir valves selectively allowing air to pass through the reservoir valve between the reservoir tank and the central air line.

14. The air management system of claim 13, wherein, The compressed air supply unit includes a compressor having at least one compressor stage for providing compressed air to the reservoir tank, and the compressed air supply unit defines a boost inlet port; and The air management system further includes a boost valve between the reservoir air line and a boost air line connected to the boost inlet port for allowing air from the reservoir tank to pass to the compressor or the pilot control port via the boost inlet port.

15. The air management system of claim 13, further comprising: an electronic control unit electrically connected to each of the at least one suspension valve, the first reservoir valve, and the second reservoir valve to selectively open and close each of them; and a pressure sensor electrically coupled to the electronic control unit and connected to the central air line for reading a pressure of the at least one air spring.

16. The air management system of claim 13, further comprising: a dryer disposed within the compressed air supply unit and coupled to the compressed air port for reducing moisture in the air before the air supplied by the compressed air supply unit enters the reservoir tank and the at least one air spring; and a dryer isolation valve disposed in series with the compressed air port for allowing the central air line to be isolated from the dryer.

17. The air management system of claim 1, wherein, The reservoir tank is an external tank located outside of the compressed air supply unit and has a volume of 7 to 16 liters.

Images