HK1226032B - Tire management system - Google Patents

Description

Tire Management System

This application is a divisional application of the invention patent application entitled “TIRE MANAGEMENT SYSTEM”, with an international application date of November 21, 2011, an international application number of PCT/US2011/061728, and a national application number of 201180055388.X.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority to U.S. Patent Application No. 61/415,733, filed November 19, 2010, entitled "Wide-Base Tire Management System," the entire contents of which are incorporated herein by reference.

Technical Field

The systems and methods disclosed herein generally relate to tire pressure maintenance.

Background Art

Wide-base tires and other types of tires experience changes in tire pressure as the vehicle on which they are mounted changes altitude, experiences braking, or is exposed to sunlight and darkness. A need exists for a tire management system that can adjust the tire pressure in wide-base tires or other types of tires to maintain a relatively constant tire pressure.

Summary of the Invention

A tire management system for a truck or trailer including an axle having a first tire mounted thereon, the tire management system comprising: an air pressure supply source connected to the first tire to permit sealed communication of pressurized air between the air pressure supply source and the first tire; and a first pilot-operated one-way valve in sealed fluid communication with the air pressure supply source and the first tire, the first pilot-operated one-way valve being configured such that when a pilot valve of the first pilot-operated one-way valve is not actuated, the first pilot-operated one-way valve permits air to flow only from the air pressure supply source to the first tire, and when the pilot valve of the first pilot-operated one-way valve is actuated, the first pilot-operated one-way valve permits air to flow between the first tire and the air pressure supply source.

1. A method of managing tire pressure on a truck or trailer including an axle having a tire mounted thereon, the method comprising: connecting an air pressure supply source to the tire to permit sealed communication of pressurized air between the air pressure supply source and the tire; and connecting a pilot-operated one-way valve to the air pressure supply source and the tire to permit sealed fluid communication between the pilot-operated one-way valve and the air pressure supply source and the tire, the pilot-operated one-way valve being configured such that when a pilot valve of the pilot-operated one-way valve is not actuated, the first pilot-operated one-way valve permits air to flow only from the air pressure supply source to the tire, and when the pilot valve of the pilot-operated one-way valve is actuated, the pilot-operated one-way valve permits air to flow between the tire and the air pressure supply source.

A tire management system for a truck or trailer having an axle mounted with a first tire, the tire management system comprising: a pressure device for providing pressurized air to the tire; and a flow device in sealed fluid communication with the pressure device and the tire so as to allow air to flow only from the pressure device to the tire when the flow device is not actuated, and to allow air to flow between the tire and the pressure device when the flow device is actuated.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows one embodiment of a vehicle having an automatic tire inflation system.

FIG. 2 shows an exemplary automatic tire inflation system.

FIG3 shows a schematic diagram of an embodiment of a tire management system.

FIG. 4 shows a flow chart of an embodiment of a process for pressurizing a tire based on tire pressure in the tire management system of FIG. 3 .

FIG. 5 shows a flow chart of an embodiment of a process for turning on an indicator light in the tire management system of FIG. 3 .

DETAILED DESCRIPTION

As shown in FIG1 , a vehicle 100 may include a truck 102 and a trailer 104. The truck 102 may include one or more drive axles 106 as part of the vehicle's drivetrain. The truck 102 may also include a steering axle (not shown in detail) having a pivotable spindle that provides steering capability for the vehicle 100. The trailer 104 may include one or more fixed axles (not shown). Each axle may have one or more wheels 108 mounted thereon. A pneumatic tire 110 may be mounted on each wheel 108. Each axle may have one tire 110 on each end of the axle, such as the wide-base tire 210 shown in FIG2 , or may have two or more tires attached at each end of the axle, such as the two tires 110 on each end of the drive axle 106 shown in FIG1 .

The vehicle 100 can be equipped with an automatic tire inflation system (ATIS) that uses the vehicle's air brake system or some other pressurized air supply source to maintain the tires 110 at a desired air pressure, such as various ATIS manufactured by Pressure Systems International, Inc. (PSI), Hendrickson, Airgo, Vigia, and others. An automatic tire inflation system can be used to control the air pressure in one or more tires 110 mounted on a steering axle (not shown), a drive axle 106, or a trailer axle (not shown). As shown in FIG1 , the automatic tire inflation system can include one or more air hoses 112 in fluid communication with each tire 110 for passing air from an air pressure supply source 114 to and from the one or more tires 110. These systems can provide pressurized air to the tires 110 via a rotary joint mounted on or in the wheel end assembly, thereby pressurizing the tires 110. Suitable swivels and other suitable tire inflation system components may include those disclosed in U.S. Pat. Nos. 6,698,482, 6,105,645, 6,325,124, 6,325,123, 7,302,979, 6,269,691, 5,769,979, 6,668,888, 7,185,688, 7,273,082, 6,145,559, 7,270,365, 6,425,427, 7,963,159, and U.S. Patent Publication No. 2009/0266460, the disclosures of which are incorporated herein by reference. These systems may direct air through hoses located outside the vehicle (e.g., Vigia's system) or through sealed or unsealed axles (e.g., PSI's system). These systems may be used to inflate trailer tires 110 and/or to inflate tires 110 mounted on the steer or drive axles 106 of heavy trucks.

FIG2 illustrates in greater detail various embodiments of an automatic tire inflation system for trailer tires. A trailer 200 may include two axles 202 and 204. Some trailers may have dual tires 206 and 208 mounted at each end of axles 202 and 204, as can be seen relative to axle 202. Other trailers may have a single wide-base tire 210 mounted at each end of axles 202 and 204, as can be seen relative to axle 204. The automatic tire inflation system generally includes a pressure regulator 214 and one or more rotary air connections or swivels 216 and 218 mounted in or near the axle ends. The pressure regulator 214 may receive pressurized air from an air pressure supply 114 via a conduit 212. The air pressure supply 114 may include, for example, a vehicle air brake system air supply or a boost or intensifier pump. Pressure regulator 214 can control or reduce the air pressure from air pressure supply 114 to a level, such as 110 psi, suitable for inflating tires 206 , 208 , 210 . Pressurized air can flow from pressure regulator 214 to axles 202 and 204 through conduits 222 and 228 .

Axles 202 and 204 can be solid in whole or in part, or hollow in whole or in part, and can be constructed in various ways. For illustrative purposes only, axles 202 and 204 are shown as hollow. For example, in some embodiments, the axle can include a solid beam with a spindle (not shown) attached to each end. The axle spindle can be configured to allow for the installation of wheel bearings on which a wheel hub (not shown) can be rotatably mounted. In other embodiments, the axle can include a hollow tube with a spindle attached to each end. The spindle can be hollow, thereby creating a hollow axle that is open at each end. Alternatively, the spindle can be solid in whole or in part, thereby creating a hollow axle that is closed at each end.

If the axle is open at the ends, the axle can be sealed with a plug or cover, such as disclosed in U.S. Patent Nos. 5,584,949, 5,769,979, 6,131,631, 6,394,556, 6,892,778, and 6,938,658, thereby allowing the hollow axle to retain pressurized air and support an air duct or rotary air joint (or components thereof). The open ends can also be provided with a plug or cover, such as disclosed in one of U.S. Patent Nos. 6,325,124 and 7,273,082, which not only seals the hollow axle to retain pressurized air but also serves to support an air duct or rotary air joint (or components thereof).

In the embodiment of FIG. 2 , axles 202 and 204 can be hollow, sealed axles. In one embodiment, axle 204 can be hollow and sealed to serve as part of a pressurized air duct 222. Air duct 222 can be sealingly connected to axle 204, allowing pressurized air to flow from pressure regulator 214 to axle 204. As described in more detail below, pressurized air can flow through axle 204 to a rotary air connector 216 mounted in or near the end of a spindle. Air hose 112 can be connected to rotary air connector 216 leading to a valve stem 221 of a wheel 209 on which a tire 210 is mounted, thereby allowing pressurized air to flow into and/or out of tire 210.

In some embodiments, air duct 222 can be sealingly connected to T-piece 226, thereby allowing pressurized air to flow to axle 202 and axle 204. Air duct 228 can, for example, allow pressurized air to flow from T-piece 226 to duct 230 disposed within axle 202. Axle 202 can carry air duct 230, thereby communicating pressurized air to rotary air connector 218, such as disclosed in U.S. Patents 6,325,124 and 7,273,082. Air hoses 112, 232 can connect rotary air connector 218 to valve stem 219 of a wheel to which tires 206 and 208 are mounted, thereby enabling pressurized air to flow to and/or from tires 206 and 208. In other embodiments, if axle 202 is solid, a channel can be drilled into axle 202 to allow all or part of duct 230 to be located within axle 202.

The pressure in wide-base tires is more susceptible to temperature, atmospheric pressure, and altitude than in standard-width tires. Pressure can vary based on many factors, such as load, altitude, and temperature. Tire pressure is higher when carrying heavier loads. For example, the temperature of a stationary tire can rise from night to day and when the tire is exposed to sunlight, thereby increasing tire pressure. Similarly, tire temperature can increase during use, thereby increasing tire pressure. Alternatively, tire pressure can increase with changing atmospheric conditions (such as when a low-pressure weather system develops). Tire pressure can also increase when driving from a lower altitude to a higher altitude. Therefore, tire pressure often exceeds the target pressure of the automatic tire inflation system at many times of the day. Conversely, tire pressure can decrease when driving from a higher altitude to a lower altitude, as day turns to night, or when tires 206, 208, 210 come to rest. When tire pressure drops below the target pressure of the automatic tire inflation system, the automatic tire inflation system can increase pressure in tires 206, 208, 210.

3 , the disclosed tire management system 300 can provide pressurized air to wide-base tires 302, 304, 306, and 308, enabling drivers and maintenance personnel to not only detect abnormal tire pressure but also easily determine which tire 302, 304, 306, and 308 is experiencing the abnormal pressure. A tire inflation system (such as those described and incorporated by reference above) can be used as part of the tire management system 300 to provide air to tires 302, 304, 306, and 308. In some embodiments, tires 302, 304, 306, and 308 are wide-base tires mounted on the drive axles of heavy-duty trucks or on trailers. As described above, heavy-duty trucks and trailers typically include two tires mounted on each axle in a dual-tire configuration, i.e., four tires per axle. However, heavy-duty trucks are increasingly adopting a single wide-base tire instead of dual tires, i.e., two tires per axle. Thus, a dual-axle trailer may have only four wide-base tires 302, 304, 306, and 308, rather than eight standard-width tires. Wide-base tires 302, 304, 306, and 308 may include those manufactured by Michelin, such as the Super Single X One tire. However, the system disclosed herein is equally applicable to dual-tire or multi-tire configurations. In this case, the tires denoted by reference numerals 302, 304, 306, and 308 may each comprise a set of two or more tires.

An air pressure supply source 114 (e.g., an air pressure supply source for a truck's air brakes) can provide pressurized air to a regulator 214 via a conduit. An air filter 310 can be provided to clean the air passing to the regulator 214, and a shutoff valve 312 can be provided to selectively allow or prevent fluid communication between the air pressure supply source 114 and the regulator 214. The regulator 214 can be of any suitable type, such as the LR-1/8-D-0-mini-NPT model manufactured by Festo, and can be set to pass air at, for example, 100 psi or any other pressure suitable for maintaining the desired tire inflation pressure. The regulator 214 can pass air to one or more outlet ports 380, 382, and 384.

A pressure switch 316 may be connected to the first outlet port 380 to detect the air pressure at the outlet port 380 of the regulator 214. If the air at the outlet port 380 is below a predetermined pressure, the pressure switch 316 may not send a signal to the indicator light 362. If the air at the outlet port 380 is at or above a predetermined pressure, the pressure switch 316 may generate a signal to turn a light 362 on or off the control panel 360. The light 362 may, for example, be a green "system normal" light 362, indicating that the air pressure at the driver port 380 is at or above the predetermined pressure. Alternatively, when the light 362 receives a signal from the switch 316, the light 362 may turn off red and turn on green. The pressure switch 316 may also send a signal to a microprocessor or other mechanism for signal processing (e.g., A/D conversion and encoding). The signal may be transmitted wirelessly or via a wired transmission method. The signal may also be transmitted to a remote dispatch station for fleet management, for example, via satellite, cellular mode, or other wireless transmission methods. Light 362 can be mounted in the vehicle cab or in front of the trailer so that the driver can see the light reflected in the side mirror. Pressure switch 316 can alternatively or also send a signal to illuminate a light in the vehicle cab or elsewhere in the vehicle. The air pressure sensed by pressure switch 316 at port 380 can indicate the air pressure passing through regulator 214. When the air pressure in tires 302, 304, 306, and 308 is allowed to equalize between these tires 302, 304, 306, and 308, the air pressure sensed by pressure switch 316 at port 380 can also indicate the pressure at tires 302, 304, 306, and 308.

Solenoid valve 318 can be connected to third outlet port 384 of regulator 214 to receive pressurized air from regulator 214. Preferably, solenoid valve 318 in the unactuated position prevents pressurized air from flowing out of regulator 214 through solenoid valve 318. Solenoid valve 318 can be of any suitable type, such as model MFH-3-M5 manufactured by Festo (Hauppauge, NY, USA). The solenoid valve can be connected to the ignition control of truck 102 via a wireless or wired link so that the solenoid is actuated when the truck's ignition is on. When the truck's ignition is off, the solenoid is not actuated. When solenoid valve 318 is actuated, pressurized air can flow from regulator 214 through solenoid valve 318 to pilot-operated check valves 328, 330, 332, and 334. Of course, switches and relays can be implemented electronically using a PCB and appropriate software, and smaller or larger air valves can be used.

Solenoid valve 318 can also be pneumatically actuated. In some embodiments, solenoid valve 318 can be pneumatically actuated and can be in fluid communication with an air pressure supply source, such as air pressure supply source 114. In some embodiments, air pressure supply source 114 can be the air pressure supply source for the air brakes. In many air brake systems, the default position of the air brakes is an engaged braking position. The air brakes are maintained in a disengaged, non-braking position by air pressure from the air pressure supply source. Air pressure can be released to apply the air brakes by pressing an air brake pressure release button in the cab of truck 102. The air brake button releases or "bleeds" the air pressure from the air brake system, thereby automatically moving the air brakes to the engaged braking position. In some embodiments, pneumatic solenoid valve 318 can be in fluid communication with the air in the air brake system and actuated while air pressure is present in the air brake system. When the air pressure in the air brake system is "bled," pneumatic solenoid valve 318 can move to the non-actuated position. Thus, the pneumatic solenoid valve 318 can be pneumatically operated by pressurized air from the air brake system. In other embodiments, the pneumatic solenoid valve 318 can be operated by other systems from the tractor or trailer, such as an air pump or a pressurizing pump.

Pilot-operated check valves 328, 330, 332, and 334 can be connected to the second outlet port 382 to allow pressurized air to communicate with the regulator 214. The pilot-operated check valves 328, 330, 332, and 334 can be of any suitable type, such as the HGL-1/8 NPT 34877 model manufactured by Festo. The pilot-operated check valves 328, 330, 332, and 334 can allow pressurized air to flow in only one direction (i.e., from the regulator 214 toward the tires 302, 304, 306, 308) unless inhibited by a pilot signal from the solenoid valve 318, as described below. If inhibited, the check valves will open to allow air to flow in both directions.

The pilot-operated check valves 328, 330, 332, and 334 may be connected to flow switches 336, 338, 340, and 342, respectively, which in turn may be connected to optional shutoff valves 346, 348, 352, and 354, respectively, to allow pressurized air to flow from the regulator 214 through the pilot-operated check valves 328, 330, 332, and 334, through the flow switches 336, 338, 342, and 344, through the shutoff valves 346, 348, 352, and 354 (if open), and to the tires 302, 304, 306, and 308.

When the solenoid valve 318 is not actuated, air can flow through the pilot-operated check valves 328, 330, 332, and 334 in only one direction (i.e., from the regulator 214 to the tires 302, 304, 306, and 308). When the solenoid valve 318 is actuated, pressurized air can flow from the solenoid valve 318 to the pilot-operated check valves 328, 330, 332, and 334, thereby causing the pilot piston to move or serving as a pilot signal or actuating the pilot signal. For example, in some embodiments, the pilot-operated check valves 328, 330, 332, and 334 can be electronic check valves, and the pilot signal can be actuated by an electronic pressure sensor. The pilot signal may change the one-way function of the one-way valve, thereby enabling air to flow in both directions, from the regulator 214 to the tires 302 , 304 , 306 , and 308 and from the tires 302 , 304 , 306 , and 308 to the regulator 214 .

Similarly, when solenoid valve 318 is not actuated and air flows solely through pilot-operated check valves 328, 330, 332, and 334 toward tires 302, 304, 306, and 308, the pressure in each tire is independent of the other tires. If tire 302 develops a leak, air cannot flow from tires 304, 306, and 308 toward tire 302 and lose pressure. This feature helps prevent, for example, a flat tire from causing all tires to go flat when a vehicle is parked overnight in a truck stop. Air can escape from the leaking tire 302, but not from tires 304, 306, and 308.

However, when the solenoid valve is actuated, thereby allowing air to flow back to the regulator 214 through the pilot-operated one-way valves 328, 330, 332, and 334, each tire 302, 304, 306, and 308 is in fluid communication with the other tires. This allows all tires to maintain the same pressure. For example, if one side of the vehicle faces the sun, the tires 302 and 304 on this side will be significantly warmer than the tires 306 and 308 on the side facing away from the sun, and will accordingly have a higher pressure. Allowing fluid communication between the tires 302, 304, 306, and 308 allows the pressure to equalize among these tires 302, 304, 306, and 308, thereby preventing wear on the pneumatic tires.

In another embodiment, system 300 may exclude solenoid valve 318 if the pilot-operated check valves 328, 330, 332, and 334 are electrically operated. The electrically operated pilot-operated check valves may be set to a one-way flow position by default and move to a two-way flow position upon actuation. The electronically operated pilot-operated check valves may be connected to the vehicle ignition and electrically actuated when the ignition is turned on and the vehicle is started. Alternatively, if the pilot-operated check valves 328, 330, 332, and 334 are pneumatically operated, they may be actuated by air from an air pressure supply (e.g., a truck's air brake system) as described above. Thus, when the air brake system is pressurized, the pilot-operated check valves 328, 330, 332, and 334 may be actuated to allow air to flow in both directions. If air is vented from the air brake system, such as when the truck is parked, the pilot-operated check valves may be deactivated, allowing only one-way air flow. Therefore, the solenoid valve 318 is optional.

If all tires 302, 304, 306, and 308 experience an increase in pressure, for example due to a change in altitude, air can flow back to regulator 214 through pilot-operated one-way valves 328, 330, 332, and 334 upon actuation of solenoid valve 318. In some embodiments, pressure relief valves 320, 322, 324, 326 can be provided in connection with one or more of the pilot-operated one-way valves 328, 330, 332, and 334 to allow excess pressure to escape from tires 302, 304, 306, 308. In some embodiments, one or more pressure relief valves 320, 322, 324, 326 can be provided at any location between the air supply source and the tire volume. In the embodiment of FIG. 3 , pressure relief valves 320, 322, 324, and 326 are positioned adjacent to pilot-operated check valves, for example. In other embodiments, pressure relief valves 320, 322, 324, and 326 may be positioned between pressure relief valves 336, 338, 342, and 344 and shutoff valves 346, 348, 352, and 354. In some embodiments, pressure relief valves 336, 338, 342, and 344 are mechanically operated by releasing air when air pressure acting against a spring-operated valve exceeds a predetermined pressure. In some embodiments, the pressure relief valves are solenoid valves. The solenoid valves can open when air pressure sensed by a pressure sensor exceeds a predetermined pressure. The pressure sensor can generate a signal for opening and closing the solenoid valves. In some embodiments, because the solenoid valves can quickly move to an open or closed position upon receiving a signal from the pressure sensor, pressure can be released more quickly through the solenoid valves than with mechanically operated pressure relief valves. In some embodiments, as the pressure in tires 302 , 304 , 306 , and 308 gradually changes and exceeds the predetermined pressure, the mechanically operated pressure relief valve will transition more slowly between the open and closed positions.

In still other embodiments, regulator 214 can include a pressure relief valve that releases air when the pressure exceeds a pressure setting of regulator 214 (e.g., 100 psi). In some embodiments, pressure relief valves 320, 322, 324, 326 (e.g., the pressure relief valves from FIG. 3 ) can be set to release air when the tire is over-pressurized by a certain target value (e.g., +10 psi) above the desired pressure. Thus, if the target tire air pressure is set to 100 psi, then if the tire pressure exceeds 110 psi, pressure relief valves 320, 322, 324, 326 will release air from tire 110. Alternatively, the pressure relief valves can relieve pressure if the air pressure exceeds the desired target pressure by any amount.

Flow switches 336, 338, 342, and 344 can be actuated by airflow exceeding a predetermined volumetric flow rate. Typically, tire inflation systems add air in small amounts as needed, or at a constant flow rate. However, if a tire punctures or develops a significant leak, for example, more air will flow to that tire to maintain its inflation. For example, if tire 302 is leaking due to a cut in the sidewall, air can escape rapidly. More air will flow from regulator 214, through pilot-operated check valve 328, through flow switch 336, and then through shutoff valve 346 to tire 302. When flow switch 336 detects that the air flow exceeds a predetermined flow rate or air flow rate, the additional air flowing to the leaking tire 302 actuates flow switch 336. Upon actuation, flow switch 336 can send a signal, either wired or wirelessly, to illuminate a "low tire pressure" indicator light 356 and, in addition, a corresponding indicator light 363 on control panel 360. Alternatively, flow switch 336 can also actuate shutoff valve 346 to close, thereby preventing further air flow to tire 302. Preferably, even in the event that shutoff valve 346 prevents further air flow through flow switch 336 and thereby ceases actuation of flow switch 336, "low tire pressure" indicator light 356 will remain illuminated until reset switch 372 corresponding to indicator light 363 is pressed or triggered. Thus, each tire 302, 304, 306, 308 can be in fluid communication with flow switches 336, 338, 342, 344, respectively, which can actuate "low tire pressure" indicator light 356 and indicator lights 363, 364, 366, 368, respectively. Reset switches 372, 374, 376, and 378 can be used to reset indicator lights 363, 364, 366, 368, respectively.

In some embodiments, a high temperature warning system 358 (e.g., the PSI ThermAlert ^™ system disclosed in U.S. Patent Nos. 6,892,778 and 7,416,005, the disclosures of which are incorporated herein by reference) can be used in conjunction with the inflation system. This high temperature warning system can utilize pressurized air provided by the regulator 214. In these embodiments, a flow switch 340 can be fluidly connected to the second outlet port 382 of the regulator 214. The flow switch 340 can be connected to a shutoff valve 350, which can be connected to a temperature-activated pressure barrier, such as a plug having a eutectic alloy that melts when temperatures are reached that are dangerous for continued safe operation of the wheel end. Thus, air can flow from the regulator 214 through the flow switch 340 and the shutoff valve 350 to the pressure barrier. If the pressure barrier senses high temperatures, it releases pressurized air, thereby actuating the flow switch 340. When activated, the flow switch 340 can send a signal to illuminate an indicator light 358 positioned within the driver's field of view. As described above, the flow switch 340 can also send a signal to illuminate the "System OK" light 362 in a different color or to turn it off, depending on the situation. Having separate flow switches 340 and indicator lights 358 also allows the driver to determine whether low pressure is due to a tire leak or due to activation of the high temperature warning system.

In some embodiments, signals from each of the flow switches 336, 338, 340, 342, 344 and the pressure switch 316 can be transmitted via wired or wireless communication to an indicator panel in the truck cab, or wirelessly to a fleet dispatcher terminal. The indicator panel or terminal can provide a visual or audible indication of low tire pressure, and can also indicate which tire has low pressure, or whether a high temperature warning system has detected a high temperature at the wheel end assembly. Wireless transmission can be achieved using any suitable technology, such as satellite, Bluetooth, cellular network, WiFi, WiMax, etc.

In some embodiments, the disclosed tire management system 300 can be used in conjunction with a tire pressure monitoring system (e.g., a wireless tire pressure monitoring system provided by Pressure Pro.). For example, tire pressure sensors (not shown) can be located at the ends of the wheels, or can be located between the flow switches 336, 338, 342, 344 and the pilot-operated check valves 328, 330, 332, 334 for tires 302, 304, 306, 308. The tire pressure sensors can detect tire pressure and send a signal indicating the tire pressure to the driver or a remote dispatch center. For example, if the truck and trailer are parked with the ignition off and the pilot-operated check valves 328, 330, 332, and 334 only allow flow in one direction, the tire pressure sensors can still detect tire pressure and transmit it to the driver and/or a remote dispatch center.

In some embodiments, the disclosed tire management system 300 can be used in conjunction with load monitoring systems typically found on air-powered trailers. For example, a load sensor used in conjunction with the trailer's airbag suspension can sense the trailer load. For example, the trailer may have an airbag to cushion road loads and maintain the trailer bed at a constant height. In some embodiments, a leveling valve can be attached to the trailer frame and provided with a lever arm to open and close the valve. If the trailer is empty, the airbag may contain sufficient air pressure to maintain the trailer bed at a constant height. If the trailer is loaded and the trailer bed drops under its weight, the lever arm can contact a suspension component, opening the valve and allowing air to flow into the airbag. As pressure builds in the airbag, the trailer rises until the lever no longer contacts the suspension component, thereby closing the valve. Alternatively, the valve can be electronically actuated based on pressure from a pressure sensor in the airbag and/or a contact switch operated according to the trailer's height. The pressure in the airbag can indicate the weight of the trailer load.

In this embodiment, regulator 214 may be an electronic pressure regulator that utilizes a servo or solenoid valve mechanism to automatically increase or decrease air pressure based on signals from a processor. When the airbag pressure exceeds a certain threshold, indicating a certain trailer weight, an air pressure sensor in the airbag can send a signal to the processor. The processor can then send a corresponding signal to regulator 214 to increase or decrease the pressure threshold, thereby allowing air to flow through the regulator to add or release air to the tire as appropriate, until the airbag pressure re-exceeds the threshold. In other words, tire management system 300 can inflate or deflate the tire to meet the pressure threshold. Generally, if the airbag is deflated to accommodate a lighter load, air can be released from the tire to reduce tire pressure. Similarly, if the airbag is inflated to accommodate a heavier load, air can be added to the tire to increase tire pressure. In some embodiments, a microprocessor can be used to set various pressure thresholds for regulator 214 based on trailer load, allowing tire pressure to be adjusted accordingly. Thus, the regulator 214 or pressure threshold may be set or automatically adjusted based on the trailer load, and air may be added to the tire at increased pressure to accommodate the heavier load.

In some embodiments, the load can be determined by sensing the pressure in the air bladder. The load-specific tire pressure can be determined using an algorithm or a data table. The air bladder pressure sensor can send an air bladder pressure signal to the processor. The processor can calculate the load-specific tire pressure. A pressure sensor in fluid communication with the air in the tire can sense the tire pressure and send a signal corresponding to the tire pressure to the processor. The processor can compare the load-specific tire pressure with the tire pressure. If the tire pressure is higher than the load-specific tire pressure, air can be released from the tire. However, if the tire pressure is lower than the load-specific tire pressure, air can be added to the tire via the tire inflation system. In some embodiments, the tire can be inflated using an electronic pressure regulator, such as the QPV series regulator manufactured by Equilibar (Fletcher, NC), or a solenoid valve system in fluid communication with the air pressure supply source 114 and the tire. In some embodiments, air can be released from the tire via one or more electronically actuated pressure relief valves.

FIG4 illustrates one embodiment of a method 400 for adjusting tire pressure based on a trailer load. The method may begin, and at 402, the pressure in the airbag may be sensed, for example, using a pressure sensor. At 404, the load-specific tire pressure may be determined. Then, at 406, the regulator may be adjusted to match the load-specific tire pressure. The pressure in the tire may also be sensed at 408. It may then be determined whether the actual tire pressure is greater than the load-specific tire pressure. If the actual tire pressure is greater than the load-specific tire pressure, a pressure relief valve may be actuated to release air. If the actual tire pressure is not greater than the load-specific tire pressure, the tire may be inflated as needed.

For example, the chart below shows load-specific tire pressures that may correspond to a load placed on a 445/50R22.5X2LRL tire.

Load (lbs.) Load-specific tire pressure (psi) 13880 75 14620 80 15360 85 16060 90 16780 95 17480 100 18180 105 18740 110 19560 115 20400 120

In some embodiments, the processor can receive the airbag pressure signal and can then calculate the approximate load on the trailer based on the airbag pressure using an algorithm. The processor can then calculate the load-specific tire pressure corresponding to the load using a chart similar to the above chart in a data table stored in an associated memory. The above chart can be generated or approximated using the following exemplary algorithm, which can be used to more accurately calculate the load-specific tire pressure based on the load:

y＝.006757x-18.7838

Where x is equal to the load, and y is equal to the load-specific tire pressure. Therefore, the processor can calculate the load-specific tire pressure using an algorithm similar to the previous algorithm.

Control panel 360 may include circuitry of conventional electrical components, such as relays, resistors, and switches, or may include an integrated circuit board and processor programmed to actuate indicator lights upon receiving and processing signals from flow switches 316, 336, 338, 340, 342, and 344. For example, as shown in FIG5 , a method for illuminating an indicator light in the tire management system of FIG3 begins at 500 , and air flow through the flow switch is sensed at 502 . A determination may then be made at 504 whether the sensed air flow meets or exceeds a predetermined air flow rate. If the sensed air flow rate does not meet or exceed the predetermined air flow rate, the corresponding indicator light may not be illuminated at 506 . If the sensed air flow rate meets or exceeds the predetermined air flow rate, the corresponding indicator light may be illuminated at 508 . The method 500 may then terminate.

The predetermined gas flow rate can be set slightly higher than the normal gas flow rate expected for normal operation of the system 300. The predetermined gas flow rate can be set by the user and can be set to different flow rates for different switches in the system 300. In some embodiments, the predetermined gas flow rate can be determined by a processor and can be changed by the processor.

In an exemplary embodiment, each flow switch 336, 338, 342, 344 can correspond to an indicator light 363, 364, 366, and 368, respectively, which can correspond to tires 302, 304, 308, and 306, respectively. Thus, a user can know which tire is experiencing increased flow by seeing which of the indicator lights 363, 364, 366, and 368 is illuminated. Those skilled in the art will appreciate that an indicator light can receive a signal and can illuminate, extinguish, change color, emit a sound, or perform some other indicator function to alert the driver.

Each of the indicator lights 362, 364, 366, and 368 may correspond to a reset switch 372, 374, 376, and 378, respectively, which may reset the indicator lights 362, 364, 366, and 368 after they have illuminated. Other reset switches (not shown) may correspond to the low tire pressure light 361 and the ThermAlert ^™ light 358. The process 400 then ends at 412.

Although the present invention and its advantages have been described in detail, it will be understood that various changes, substitutions and modifications may be made therein without departing from the scope of the invention as defined by the appended claims. Furthermore, the scope of this application is not intended to be limited to the specific embodiments of the processes, machines, manufactures, compositions of matter, means, methods and steps described in the specification. As will be readily understood from the disclosure, currently existing or subsequently developed processes, machines, manufactures, compositions of matter, means, methods or steps may be employed that perform substantially the same functions or achieve substantially the same results as the corresponding embodiments described herein. Therefore, the appended claims are intended to include within their scope such processes, machines, manufactures, compositions of matter, means, methods and steps.

Claims (18)

1. A tire pressure management system, comprising an axle on which a first tire and a second tire are mounted, the tire pressure management system comprising: An air pressure supply source is hermetically connected to the first tire and the second tire to allow a substantially continuous sealed communication of pressurized air between the air pressure supply source and the first tire and the second tire; A pressure regulator located between the air pressure supply source and the first tire and the second tire, and in sealed fluid communication with the air pressure supply source and the first tire and the second tire, the pressure regulator including a pressure setpoint to regulate the pressure of the air passing through the pressure regulator; A processor configured to control the pressure setpoint; and A load sensor is configured to generate a first electrical signal indicating the load weight sensed by the load sensor and to send the first electrical signal to a processor for controlling a pressure setpoint of the pressure regulator, wherein the processor is configured to receive the first electrical signal and automatically adjust the pressure setpoint based on the first electrical signal. 2. The tire pressure management system of claim 1, further comprising a pressure relief valve in sealed communication with the first tire and the second tire, the pressure relief valve being configured to release air from the first tire and the second tire when the pressure in the first tire and the second tire exceeds a pressure set value of the pressure regulator. 3. The tire pressure management system of claim 2, wherein the pressure regulator also includes a pressure relief valve configured to release excess tire pressure. 4. The tire pressure management system of claim 2 further includes a flow switch in sealed fluid communication with the first tire and the second tire, the flow switch being configured to generate a second electrical signal when the air flow through the flow switch exceeds a predetermined flow rate. 5. The tire pressure management system of claim 4, wherein the pressure regulator is in fluid communication with the flow switch. 6. The tire pressure management system of claim 2, wherein the load sensor is a pressure sensor that senses the load weight by sensing the pressure in the airbag. 7. The tire pressure management system of claim 2, wherein the tire pressure management system further comprises a tire pressure sensor that senses the tire pressure in one or both of the first tire and the second tire. 8. The tire pressure management system of claim 2, wherein the processor is adapted to receive the first electrical signal, determine a load-specific tire pressure based on the first electrical signal, and adjust the pressure regulator to match the load-specific tire pressure. 9. The tire pressure management system of claim 8, wherein the processor is adapted to determine the load weight based on the first electrical signal, and then determine the load-specific tire pressure corresponding to the load weight. 10. The tire pressure management system of claim 1, wherein the sealed fluid communication allows air to flow between the first tire and the second tire and the pressure regulator, thereby making the pressure in the first tire and the second tire substantially equal. 11. The tire pressure management system of claim 10, further comprising: A first pilot valve-operated check valve is located between the pressure regulator and the first tire, and is in sealed fluid communication with both the pressure regulator and the first tire. The second pilot valve operated check valve is located between the pressure regulator and the second tire, and is in sealed fluid communication with the pressure regulator and the second tire. Each of the first pilot valve-operated check valve and the second pilot valve-operated check valve is configured such that, when not actuated, air is allowed to flow only from the pressure regulator to the first tire and the second tire, respectively, while when actuated, air is allowed to flow between the pressure regulator, the first tire, and the second tire. 12. The tire pressure management system of claim 11, further comprising a solenoid valve in sealed fluid communication with the pressure regulator and in sealed fluid communication with a pilot valve of each of the first pilot valve-operated check valve and the second pilot valve-operated check valve, wherein the pilot valve of each of the first pilot valve-operated check valve and the second pilot valve-operated check valve is pneumatically actuated, and the solenoid valve is configured to allow pressurized air to flow from the pressure regulator to each pilot valve when the solenoid valve is actuated, thereby actuating the pilot valve. 13. The tire pressure management system of claim 12, wherein the solenoid valve is electrically operable and configured to be actuated when the vehicle ignition device is actuated. 14. The tire pressure management system of claim 12, wherein the solenoid valve is pneumatically operable and configured to be actuated when the vehicle's air braking system is pressurized. 15. The tire pressure management system of claim 11, further comprising: A first flow switch is in sealed fluid communication with the first tire, and the first flow switch is configured to generate a first signal when the air flow rate through the first flow switch exceeds a predetermined flow rate; A first visual indicator connected to the first flow switch and capable of being activated upon receiving the first signal from the first flow switch; A second flow switch, which is in sealed fluid communication with the second tire, is configured to generate a second signal when the airflow through the second flow switch exceeds a predetermined flow rate; and A second visual indicator connected to the second flow switch and capable of being activated when the second signal is received from the second flow switch. 16. The tire pressure management system of claim 15, wherein the first visual indicator and the second visual indicator are configured to remain actuated even when the first flow switch and the second flow switch respectively cease generating the first signal and the second signal; the tire pressure management system further includes a first reset switch connected to the first visual indicator and capable of stopping actuation of the second visual indicator, and a second reset switch connected to the second visual indicator and capable of stopping actuation of the second visual indicator. 17. The tire pressure management system of claim 11, further comprising: A pressure switch, which is in sealed fluid communication with the pressure regulator, thereby enabling the pressure switch to detect the air pressure passing through the pressure regulator, the pressure switch being configured to generate a third electrical signal when the air pressure passing through the pressure regulator drops below a threshold; and A visual indicator connected to the pressure switch and capable of being activated upon receiving the third electrical signal. 18. The tire pressure management system of claim 1, wherein the first tire and the second tire are wide-base tires.