WO2014186931A1

WO2014186931A1 - Auto brake module

Info

Publication number: WO2014186931A1
Application number: PCT/CN2013/075890
Authority: WO
Inventors: Stephen Hill; Xisolin DENG; Darren DUNKLEY
Original assignee: Norgren, Inc.
Priority date: 2013-05-20
Filing date: 2013-05-20
Publication date: 2014-11-27

Abstract

An auto brake module (210, 310, 410) in a brake system (200, 300, 400) with a brake pipe (160), a brake cylinder pipe (170), and a brake cylinder (110) having a brake spring (114), a spring release chamber (116) and a service brake chamber (118), wherein the brake cylinder pipe (170) is fluidly coupled to the service brake chamber (118), the auto brake module (210, 310, 410) is provided. The auto brake module includes a brake spring release valve (212, 312) fluidly coupled to the spring release chamber (116) and the brake pipe (160) and a brake apply valve (214, 314) fluidly coupled to the spring release chamber (116), wherein the brake spring release valve (212, 312) is adapted to fluidly couple the brake pipe (160) to the spring release chamber (116) and the brake apply valve (214, 314) is adapted to exhaust the spring release chamber (116).

Description

AUTO BRAKE MODULE

TECHNICAL FIELD

The embodiments described below relate to brake systems, and more

particularly, to brake systems with a redundant pressure source.

BACKGROUND

Brake systems are often employed in the transportation industry to slow and stop moving vehicles. The brake systems may also hold vehicles in place when the vehicle is not in operation. The brake systems typically employ friction force to slow, stop and hold the vehicles. For example, the brake systems may employ a brake pad that presses onto a friction surface (e.g., disc, drum, etc.) that may be coupled to a wheel on the vehicle. Some brake systems employ pressurized fluids to press brake pads onto the friction surface. For example, a power source may pressurize a fluid in a conduit that is fluidly coupled to a brake cylinder. The brake cylinder may press the brake pad onto the friction surface. Accordingly, the pressurized fluid may slow, stop or hold the moving vehicle.

Sometimes the fluid is not pressurized which may cause a loss of the friction force. For example, the vehicle may not be in operation, such as when it is parked, and therefore may not have power available to pressurize the fluid. In another example, the power may be lost when the vehicle is in operation such as when the vehicle's engine fails. The fluid may also not be pressurized due to a failure in the conduit or brake cylinder that holds the fluid. To avoid the loss of the friction force, many brake systems include a redundant pressure source such as a spring to press the brake pad onto the friction surface when the power is not available. Such a system is described in the following with reference to FIG. 1.

FIG. 1 shows a prior art brake system 100 that employs a brake cylinder 110. As depicted, the brake cylinder 110 is coupled to a brake pad 120 which may be pressed against a friction disc 130 to create the friction force. The brake cylinder 110 includes a brake shaft 112 that is coupled to the brake pad 120 and a brake spring 114 depicted as pressed against the brake shaft 112. The brake cylinder 110 also includes a spring release chamber 116 and a service brake chamber 118. A manual application valve 140 may be fluidly coupled to the brake cylinder 110 via a brake release conduit 150. The manual application valve 140 is also depicted as fluidly coupled to a brake pipe 160. The manual application valve 140 has a manual application valve lever 142 and a manual application valve exhaust 144. Turning the manual application valve lever 142 may exhaust the spring release chamber 116. The brake release conduit 150 is coupled to the brake cylinder 110 at the spring release chamber 116. The prior art brake system 100 also includes a brake cylinder pipe 170 fluidly coupled to the brake cylinder 110 at the service brake chamber 118.

The brake cylinder 110 may be in one or more states when it is employed in the prior art brake system 100. For example, when the vehicle is moving, the brake cylinder 110 may be in a released state. In the released state, the brake cylinder 110 may not press the brake pad 120 onto the friction disc 130. To place the brake cylinder 110 in the released state, the brake pipe 160 pressure may oppose the brake spring 114 pressure in the brake cylinder 110. This may reduce or eliminate the brake spring 114 pressure on the brake shaft 112. For example, the brake spring 114 may be fully compressed.

When the vehicle is moving and being slowed down or is stopped and power is available, the brake cylinder 110 may be in a service state. In the service state, the brake cylinder 110 may press the brake pad 120 onto the friction disc 130 with a brake pressure. The brake pressure may be proportional to the brake cylinder pipe 170 pressure. For example, the brake pressure may be equal to the brake spring 114 pressure plus the brake cylinder pipe 170 pressure minus the brake pipe 160 pressure. The brake pressure may also be the same as the brake cylinder pipe 170 pressure (e.g., when the brake spring 114 is fully compressed). The brake cylinder pipe 170 pressure may be controlled by an operator.

When the vehicle is powered down or there is a loss of fluid pressure, the brake cylinder 110 may be in a redundant state. In the redundant state, the brake spring 114 may press the brake pad 120 onto the friction disc 130. In this state, the manual application valve 140 may exhaust the spring release chamber 116. Also in the redundant state, the service brake chamber 118 may have some or no pressure supplied by the brake cylinder pipe 170. For example, if the vehicle is powered down, the brake cylinder pipe 170 may not apply a pressure to the service brake chamber 118.

Accordingly, the brake spring 114 pressure may be the only pressure in the brake cylinder 110. Although the brake cylinder 110 may include the brake spring 114 as the redundant pressure source, there are several issues with the prior art brake system 100 depicted in FIG.1.

Some issues may be present when the spring release chamber 116 is pressurized. The spring release chamber 116 pressure may maintain the brake cylinder 110 in the released state even though, for example, the brake cylinder pipe 170 and the brake pipe 160 do not have pressure. To place the brake cylinder 110 in the released state, the manual application valve 140 may apply pressure to the spring release chamber 116. However, this may require that the operator turn the manual application valve lever 142. Turning the manual application valve lever 142 may be laborious and time-consuming and may not be safe. For example, while the manual application valve lever 142 is being turned by the operator, the vehicle may shift or move. Accordingly, there is a need for an auto brake module. SUMMARY

An auto brake module in a brake system with a friction disc, a brake pipe, a brake cylinder pipe, and a brake cylinder having a brake spring, a spring release chamber and a service brake chamber, wherein the brake cylinder pipe is fluidly coupled to the service brake chamber is provided. According to an embodiment, the auto brake module comprises a brake spring release valve fluidly coupled to the spring release chamber and the brake pipe. The auto brake module further comprises a brake apply valve fluidly coupled to the spring release chamber, wherein the brake spring release valve is adapted to fluidly couple the brake pipe to the spring release chamber and the brake apply valve is adapted to exhaust the spring release chamber.

A method of forming an auto brake module for a brake system with a friction disc, a brake pipe, a brake cylinder pipe, and a brake cylinder having a brake spring, a spring release chamber and a service brake chamber, wherein the brake cylinder pipe is fluidly coupled to the service brake chamber is provided according to an embodiment. The method comprises forming a brake spring release valve and fluidly coupling the brake spring release valve to the spring release chamber and the brake pipe, and forming a brake apply valve. The method further comprises fluidly coupling the brake spring release valve to the spring release chamber, wherein the brake spring release valve is formed to fluidly couple the brake pipe to the spring release chamber and the brake apply valve is formed to exhaust the spring release chamber.

A method of automatically managing a brake cylinder having a spring release chamber and a service brake chamber in a brake system that has a friction disc, a brake pipe and a brake cylinder pipe is provided according to an embodiment. The method comprises fluidly decoupling the spring release chamber from an exhaust when the brake cylinder pipe pressure is sufficient to hold the friction disc. The method further comprises fluidly coupling the a brake pipe to the spring release chamber when a pressure in the brake system is sufficient to provide enough fluid to the brake cylinder pipe to hold the friction disc during pressure fluctuations in the brake system.

ASPECTS

According to an aspect, an auto brake module (210, 310, 410) in a brake system (200, 300, 400) with a friction disc (130), a brake pipe (160), a brake cylinder pipe (170), and a brake cylinder (110) having a brake spring (114), a spring release chamber (116) and a service brake chamber (118), wherein the brake cylinder pipe (170) is fluidly coupled to the service brake chamber (118), the auto brake module (210, 310, 410) comprises a brake spring release valve (212, 312) fluidly coupled to the spring release chamber (116) and the brake pipe (160), and a brake apply valve (214, 314) fluidly coupled to the spring release chamber (116), wherein the brake spring release valve (212, 312) is adapted to fluidly couple the brake pipe (160) to the spring release chamber (116) and the brake apply valve (214, 314) is adapted to exhaust the spring release chamber (116).

Preferably, the brake spring release valve (212, 312) is further adapted to fluidly couple the brake pipe (160) to the spring release chamber (116) when the brake pipe (160) pressure is over a brake spring release valve (212, 312) actuating pressure.

Preferably, the brake spring release valve (212, 312) actuating pressure is a pressure sufficient to place the brake cylinder (110) in a released state.

Preferably, the brake spring release valve (212, 312) actuating pressure of is a pressure sufficient to ensure the brake system (200, 400) provides enough fluid to the brake cylinder pipe (170) to hold the friction disc (130) during pressure fluctuations in the brake system (200, 400). Preferably, the brake apply valve (214, 314) is further adapted to exhaust the spring release chamber (116) when the brake pipe (160) pressure and the brake cylinder pipe (170) pressure are below one or more brake apply valve (214, 314) actuating pressures.

Preferably, the one or more brake apply valve (214, 314) actuating pressures are sufficient to hold the friction disc (130).

Preferably, the auto brake module (210, 310, 410) further comprises a release choke (216) that is adapted to restrict a flow of fluid from the brake pipe (160) to the spring release chamber (116).

Preferably, the auto brake module (210, 410) further comprises a BP choke (224) that is adapted to restrict a flow of the fluid from an actuator port on the brake apply valve (214).

Preferably, the auto brake module (210, 410) further comprises an actuator port on the brake apply valve (214) and a BC BP pilot shuttle (230) adapted to fluidly couple the actuator port to the brake pipe (160) when the brake pipe (160) pressure is greater than the brake cylinder pipe (170) pressure and to the brake cylinder pipe (170) when the brake cylinder pipe (170) pressure is greater than the brake pipe (160) pressure.

Preferably, the BC BP pilot shuttle (230) is further adapted to shuttle to couple the brake pipe (160) or the brake cylinder pipe (170) to the actuator port on the brake apply valve (214) when the brake pipe (160) pressure or the brake cylinder pipe (170) pressure is over a shuttle pressure.

According to an aspect, a method of forming an auto brake module (210, 310, 410) for a brake system (200, 300, 400) with a friction disc (130), a brake pipe (160), a brake cylinder pipe (170), and a brake cylinder (110) having a brake spring (114), a spring release chamber (116) and a service brake chamber (118), wherein the brake cylinder pipe (170) is fluidly coupled to the service brake chamber (118), the method comprises forming a brake spring release valve (212, 312) and fluidly coupling the brake spring release valve (212, 312) to the spring release chamber (116) and the brake pipe (160), and forming a brake apply valve (214, 314) and fluidly coupling the brake spring release valve (212, 312) to the spring release chamber (116), wherein the brake spring release valve (212, 312) is formed to fluidly couple the brake pipe (160) to the spring release chamber (116) and the brake apply valve (214, 314) is formed to exhaust the spring release chamber (116).

Preferably, the forming the brake spring release valve (212, 312) further comprises forming the brake spring release valve (212, 312) to fluidly couple the brake pipe (160) to the spring release chamber (116) when the brake pipe (160) pressure is over a brake spring release valve (212, 312) actuating pressure.

Preferably, the brake spring release valve (212, 312) actuating pressure is a pressure sufficient to ensure the brake system (200, 400) provides enough fluid to the brake cylinder pipe (170) to hold the friction disc (130) during pressure fluctuations in the brake system (200, 400).

Preferably, the forming the brake apply valve (214, 314) further comprises forming the brake apply valve (214, 314) to exhaust the spring release chamber (116) when the brake pipe (160) pressure and the brake cylinder pipe (170) pressure are below one or more brake apply valve (214, 314) actuating pressure.

Preferably, the one or more brake apply valve (214, 314) actuating pressure are sufficient to hold the friction disc (130).

Preferably, the forming the auto brake module (210, 310, 410) further comprises forming a release choke (216) to restrict a flow of fluid from the brake pipe (160) to the spring release chamber (116).

Preferably, the forming the auto brake module (210, 410) further comprises forming a BP choke (224) to restrict a flow of the fluid from an actuator port on the brake apply valve (214).

Preferably, the forming the auto brake module (210, 410) further comprises forming an actuator port on the brake apply valve (214) and forming a BC BP pilot shuttle (230) to fluidly couple the actuator port to the brake pipe (160) when the brake pipe (160) pressure is greater than the brake cylinder pipe (170) pressure and to the brake cylinder pipe (170) when the brake cylinder pipe (170) pressure is greater than the brake pipe (160) pressure.

Preferably, the forming the BC BP pilot shuttle (230) further comprises forming the BC BP pilot shuttle (230) to shuttle to couple the brake pipe (160) or the brake cylinder pipe (170) to the actuator port on the brake apply valve (214) when the brake pipe (160) pressure or the brake cylinder pipe (170) pressure is over a BC BP pilot shuttle (230) pressure.

According to an aspect, a method of automatically managing a brake cylinder (HO) having a spring release chamber (116) and a service brake chamber (118) in a brake system (200, 300, 400) that has a friction disc (130), a brake pipe (160) and a brake cylinder pipe (170), comprising fluidly decoupling the spring release chamber (116) from an exhaust when the brake cylinder pipe (170) pressure is sufficient to hold the friction disc (130), and fluidly coupling the a brake pipe (160) to the spring release chamber (116) when a pressure in the brake system (200, 400) is sufficient to provide enough fluid to the brake cylinder pipe (170) to hold the friction disc (130) during pressure fluctuations in the brake system (200, 400).

BRIEF DESCRIPTION OF THE DRAWINGS

The same reference number represents the same element on all drawings. It should be understood that the drawings are not necessarily to scale.

FIG. 1 shows a prior art brake system 100 that employs a brake cylinder 110.

FIG. 2 shows a pneumatic brake system 200 that includes a pneumatic brake module 210 according to an embodiment.

FIG. 3 shows an ECP brake system 300 that includes a ECP auto brake module 310 according to an embodiment.

FIG. 4 shows a hybrid brake system 400 that includes a hybrid auto brake module 410 according to an embodiment. DETAILED DESCRIPTION

FIGS. 1 - 4 and the following description depict specific examples to teach those skilled in the art how to make and use the best mode of embodiments of an auto brake module. For the purpose of teaching inventive principles, some conventional aspects have been simplified or omitted. Those skilled in the art will appreciate variations from these examples that fall within the scope of the present description. Those skilled in the art will appreciate that the features described below can be combined in various ways to form multiple variations of the auto brake module. As a result, the embodiments described below are not limited to the specific examples described below, but only by the claims and their equivalents.

Additionally, the embodiments disclosed in the following are not limited to the prior art brake system 100 described with reference to FIG. 1. For example, the brake spring 114 may not be a spring but may be separate hydraulic source that provides a redundant pressure source. Also, the brake shaft 112 may not be coupled to the brake pad 120 and, instead, may just press on the brake pad 120. The brake pad 120 and the friction disc 130 may be something other than the depicted friction based brake. For example, one of ordinary skill in the art would appreciate that the embodiments disclosed in the following may be applied to electromagnetic couplings to brake a wheel, disc, or something else that is spinning. Embodiments may also be applied to braking systems that are not employed on vehicles.

FIG. 2 shows a pneumatic brake system 200 that includes a pneumatic brake module 210 according to an embodiment. The pneumatic brake module 210 is depicted as fluidly coupled to the brake cylinder 110 via the brake release conduit 150 and the brake cylinder pipe 170. The pneumatic brake module 210 is also depicted as fluidly coupled to the brake pipe 160 and includes the manual application valve 140 that is fluidly coupled to the brake release conduit 150, a pneumatic brake spring release valve 212 and a pneumatic brake apply valve 214. The pneumatic brake spring release valve 212 is fluidly coupled to a release choke 216. The release choke 216 is fluidly coupled to a main reservoir inlet filter 218 and a brake pipe check valve 220. The brake pipe check valve 220 is depicted as fluidly coupled to the pneumatic brake spring release valve 212 via a pneumatic brake spring release valve 212 actuator port. The brake pipe check valve 220 is also fluidly coupled to a brake pipe inlet filter 222, a brake pipe (BP) choke 224, and a BP check valve 226. The brake pipe inlet filter 222 is fluidly coupled to the brake pipe 160. The BP choke 224 and the BP check valve 226 are fluidly coupled to a BP reservoir 228 and a BP BC pilot shuttle 230. The BP BC pilot shuttle 230 is fluidly coupled to the brake cylinder pipe 170. The main reservoir inlet filter 218 is fluidly coupled to a main reservoir pipe 240.

The pneumatic brake spring release valve 212 is depicted as a normally open 2/2 pneumatically actuated pneumatic valve although any appropriate valve may be employed. For example, the pneumatic brake spring release valve 212 may be a pilot operated valve. The pneumatic brake spring release valve 212 may be actuated by the brake pipe 160 pressure. In the depicted state, the pneumatic brake spring release valve 212 fluidly couples the main reservoir pipe 240 to the spring release chamber 116. Accordingly, the brake cylinder 110 may be placed in the released state by the main reservoir pipe 240 pressure.

The pneumatic brake apply valve 214 is depicted as a normally open 2/2 pneumatically actuated pneumatic valve although any appropriate valve may be employed. Similar to the pneumatic brake spring release valve 212, the pneumatic brake apply valve 214 may be a pilot operated valve. The pneumatic brake apply valve 214 may be actuated by the brake pipe 160 pressure or the brake cylinder pipe 170 pressure. The pneumatic brake apply valve 214 is depicted as actuated by the brake cylinder pipe 170 pressure. That is, the brake cylinder pipe 170 pressure is coupled to the pneumatic brake apply valve 214 actuator port via the BP BC pilot shuttle 230. In the depicted state, the pneumatic brake apply valve 214 decouples the spring release chamber 116 from the exhaust (shown but not enumerated). Accordingly, the brake pipe 160 pressure or the main reservoir pipe 240 pressure may be coupled to the spring release chamber 116 to place the brake cylinder 110 in the released state.

Both the pneumatic brake spring release valve 212 and the pneumatic brake apply valve 214 may actuate when the brake pipe 160 pressure and the brake cylinder pipe 170 pressure pass their respective actuating pressures. For example, the pneumatic brake spring release valve 212 may actuate when the brake pipe 160 pressure is sufficient to ensure the pneumatic brake system 200 provides enough fluid to the brake cylinder pipe 170 to hold the friction disc 130 (referred to as a brake spring release valve actuating pressure). An exemplary brake spring release valve actuating pressure may be about 400kPa to about 420kPa. The pneumatic brake system 200 may provide enough fluid to the brake cylinder pipe 170 to hold the friction disc 130 when the main reservoir pipe 240 pressure is over a desired amount. An exemplary desired main reservoir pipe 240 pressure may be 600-900kPa. Accordingly, the pneumatic brake spring release valve 212 may not place the brake cylinder 110 in the released state until the pneumatic brake system 200 can hold the friction disc 130.

Similarly, the pneumatic brake apply valve 214 may not return to its normally open state until the brake cylinder pipe 170 is below a brake apply valve actuating pressure. An exemplary brake apply valve actuating pressure is 180-200kPa.

Accordingly, the pneumatic brake apply valve 214 may exhaust the spring release chamber 116 when the brake cylinder pipe 170 pressure and the brake pipe 160 pressure are below the brake apply valve actuating pressure. The brake apply valve actuating pressure may be sufficient to hold the vehicle (e.g., at the maximum specified grade). In other words, the brake cylinder pipe 170 pressure may be sufficient to hold the friction disc 130 before the pneumatic brake apply valve 214 actuates to release the brake spring 114. Until brake apply valve actuating pressure is reached, the brake spring 114 may press the brake pad 120 onto the friction disc 130 with sufficient pressure to hold the vehicle. Accordingly, the brake cylinder 110 may always have sufficient pressure to hold the vehicle even when the brake pipe 160 and the brake cylinder pipe 170 pressures are not sufficient to hold the friction disc 130.

Still referring to FIG.2, the release choke 216 is depicted as a flow control valve although any appropriate fluid regulation device may be employed. In the depicted embodiment, the release choke 216 is a nozzle with a cross section opening of about 2.0 mm although any suitable cross section opening may be employed. The release choke 216 may restrict the flow of fluid to the spring release chamber 116. Accordingly, the spring release chamber may slowly pressurize so the brake spring 114 is not released before the brake cylinder pipe 170 pressure is applied to the brake cylinder 110.

The main reservoir inlet filter 218 and the brake pipe inlet filter 222 are depicted as pneumatic filters although any appropriate fluid processing device may be employed. In the depicted embodiment, the main reservoir inlet filter 218 may filter particulates from fluid flowing between the main reservoir pipe 240 and the pneumatic brake spring release valve 212. Similarly, the brake pipe inlet filter 222 may filter particulars or other fluid components from the fluid flow between the brake pipe 160 and the pneumatic brake spring release valve 212 actuator port. The main reservoir inlet filter 218 and the brake pipe inlet filter 222 may also include other devices such as driers that adsorb moisture from the air. The pneumatic brake spring release valve 212 may be 25-40μπι filters although any suitable filter may be employed. Although the release choke 216, the main reservoir inlet filter 218, and the brake pipe inlet filter 222 are depicted in FIG.

2, some embodiments may not include the release choke 216, the main reservoir inlet filter 218, and the brake pipe inlet filter 222. As depicted, the brake pipe check valve 220 is a pneumatic check valve although any appropriate directional fluid regulating device may be employed. In the depicted embodiment, the brake pipe check valve 220 regulates whether the main reservoir pipe 240 pressure or the brake pipe 160 pressure places the brake cylinder 110 in the released state. As depicted, the brake pipe check valve 220 is closed thereby fluidly decoupling the brake pipe 160 from the spring release chamber 116. Accordingly, the main reservoir pipe 240 pressure may place the brake cylinder 110 in the released state. When the main reservoir pipe 240 pressure is less than the brake pipe 160 pressure, the brake pipe check valve 220 may fluidly couple the brake pipe 160 with the spring release chamber 116. The brake pipe check valve 220 may also fluidly decouple the main reservoir pipe 240 from the spring release chamber 116. Accordingly, the brake pipe 160 pressure may place the brake cylinder 110 in a released state.

As depicted, the BP choke 224 is a nozzle with a 2.0 mm opening although any appropriate fluid regulation device may be employed. The BP choke 224 may limit flow between the brake cylinder pipe 170 and the pneumatic brake spring release valve 212 actuator port. Since the BP BC pilot shuttle 230 is depicted as decoupling the pneumatic brake spring release valve 212 actuator port from the brake cylinder pipe 170 fluid may not flow between the brake cylinder pipe 170 and the pneumatic brake spring release valve 212 actuator port.

The BP check valve 226 is depicted in a closed position. As a result, fluid flowing from the BP BC pilot shuttle 230 to the pneumatic brake spring release valve 212 actuator port may only flow through the BP choke 224. Fluid flowing from the brake pipe 160 to the pneumatic brake apply valve 214 may flow without going through the BP choke. Accordingly, the pneumatic brake apply valve 214 may actuate to exhaust the spring release chamber 116 before, for example, the brake cylinder pipe 170 loses its pressure.

The BP reservoir 228 is depicted as a gas bottle although any fluid source or reservoir may be employed. As depicted, the BP reservoir 228 may be a 1.5L bottle. The

BP reservoir 228 may be sized to provide sufficient fluid at a sufficient pressure to maintain the pneumatic brake spring release valve 212 and the pneumatic brake apply valve 214 actuator port in their opened and closed positions, respectively. The pneumatic brake spring release valve 212 and the pneumatic brake apply valve 214 positions may be maintained during temporary pressure drops in portions of the prior art brake system 100. For example, in the depicted embodiment, the BP reservoir 228 may provide stored compressed fluid to the pneumatic brake apply valve 214 actuator port via the BP BC pilot shuttle 230 when the BP BC pilot shuttle 230 shuttles to couple the brake pipe 160 with the pneumatic brake apply valve 214 actuator port. This may occur when the brake cylinder pipe 170 pressure drops below the brake pipe 160 pressure. Accordingly, the brake cylinder 110 may remain released during temporary changes in fluid pressures in the prior art brake system 100.

The BP BC pilot shuttle 230 is depicted as a shuttle valve although any appropriate valve may be employed. In the depicted state, the BP BC pilot shuttle 230 may fluidly decouple the brake pipe 160 from the pneumatic brake apply valve 214 actuator port. The BP BC pilot shuttle 230 may be in the depicted position when the brake cylinder pipe 170 pressure is greater than the brake pipe 160 pressure. When the brake pipe 160 pressure is greater than the brake cylinder pipe 170 pressure, the BP BC pilot shuttle 230 may fluidly couple the brake pipe 160 to and decoupled the brake cylinder pipe 170 from the pneumatic brake apply valve 214 actuator port. Accordingly, the pneumatic brake apply valve 214 may be actuated by the brake pipe 160 pressure or the brake cylinder pipe 170 pressure (e.g., when either one is greater than the brake apply valve actuating pressure.)

The brake cylinder 110 is depicted as placed in the released state by the pneumatic brake module 210. As depicted, the pneumatic brake module 210 may place the brake cylinder 110 in the released state by coupling the main reservoir pipe 240 to the spring release chamber 116. The main reservoir pipe 240 may be fluidly coupled to the manual application valve 140 by actuating the pneumatic brake spring release valve 212 with the brake pipe 160 pressure. Also in the state depicted in FIG. 2, the brake cylinder pipe 170 pressure may actuate the pneumatic brake apply valve 214 to decouple the spring release chamber 116 from the exhaust.

The pneumatic brake module 210 may place the brake cylinder 110 in a redundant state (e.g., spring actuated) state when there is a loss of pressure in the brake pipe 160, the brake cylinder pipe 170, or the main reservoir pipe 240. In the redundant state, the spring release chamber 116 in the brake cylinder 110 may be exhausted the brake spring 114 to press the brake pad 120 onto the friction disc 130. In one example, the brake pipe 160 pressure and the brake cylinder pipe 170 pressure may drop below the brake spring release valve actuating pressure and the brake apply valve actuating pressure, respectively. The pneumatic brake spring release valve 212 may also fluidly de-couple the main reservoir pipe 240 (which may still have pressure) from the spring release chamber 116. The drop in the brake pipe 160 and the brake cylinder pipe 170 pressures may be due to the vehicle being stopped and powered down. For example, the pneumatic brake module 210 may automatically place the brake cylinder 110 in the redundant state during routine matters such as parking the vehicle.

Although the foregoing describes an embodiment that manages the brake cylinder 110 states in a pneumatic braking system, embodiments may manage brake cylinder 110 in other types of brake systems such as electronically controlled pressure (ECP) or hybrid ECP/pneumatic brake systems. The following describe some of these additional embodiments with reference to FIGS. 3 and 4.

FIG. 3 shows an ECP brake system 300 that includes an ECP auto brake module 310 according to an embodiment. As depicted, the ECP auto brake module 310 includes a solenoid brake spring release valve 312 that is fluidly coupled to the release choke 216 and the manual application valve 140. The ECP auto brake module 310 also includes a solenoid brake apply valve 314 that is fluidly coupled to the solenoid brake spring release valve 312 and the manual application valve 140. The solenoid brake apply valve 314 is also depicted as coupled to an exhaust (not enumerated). Similar to the pneumatic brake module 210 described with reference to FIG. 2, the ECP auto brake module 310 includes the brake pipe inlet filter 222 that is coupled to the release choke 216 and the brake pipe 160. As described with reference to FIGS. 1 and 2, the brake cylinder pipe 170 may be coupled to the brake cylinder 110.

The ECP brake system 300 is an electronic brake system. The ECP auto brake module 310 may place the brake cylinder 110 in the released position in a manner similar to that described with reference to FIGS. 1 and 2. The brake cylinder pipe 170 may fluidly couple the brake cylinder pipe 170 pressure to the brake cylinder 110. The brake cylinder pipe 170 pressure may be electronically controlled. Accordingly, if the ECP brake system 300 loses power, the brake cylinder pipe 170 may lose its pressure. As described in the following, the brake pad 120 may still be pressed onto the friction disc 130 by the brake spring 114. The solenoid brake spring release valve 312 is depicted as a normally vented 3/2 solenoid actuated pneumatic valve although any appropriate valve may be employed. In the depicted state, the solenoid brake spring release valve 312 may not fluidly couple the brake pipe 160 with the spring release chamber 116. Also, the spring release chamber 116 may be exhausted. When the solenoid brake spring release valve 312 is actuated, the solenoid brake spring release valve 312 may fluidly couple the brake pipe 160 with the spring release chamber 116, for example, by an electrical signal to the solenoid brake spring release valve 312. The solenoid brake spring release valve 312 may be actuated when the brake pipe 160 pressure passes the brake spring release valve actuating pressure. The brake pipe 160 pressure may be sensed by a pressure transducer (not shown) which in turn may actuate the solenoid brake spring release valve 312 to couple the brake pipe 160 to the spring release chamber 116. Similarly, the solenoid brake apply valve 314 is depicted as a normally vented 3/2 solenoid actuated pneumatic valve although any suitable valve may be employed. In the depicted vented state, the spring release chamber 116 is not exhausted.

As depicted, the solenoid brake spring release valve 312 and the solenoid brake apply valve 314 are shown in normally vented positions. The solenoid brake spring release valve 312 and the solenoid brake apply valve 314 may be in such position when electrical power is not applied to the solenoid brake spring release valve 312 and the solenoid brake apply valve 314 solenoids. The power may not be applied to the solenoid brake spring release valve 312 and the solenoid brake apply valve 314 solenoids when the ECP brake system 300 does not have power. Accordingly, the solenoid brake spring release valve 312 may exhaust the spring release chamber 116. The ECP brake system 300 may not have power when it is turned off when the vehicle is parked or a power source fails, or due to some other event. Due to the power loss in the ECP brake system 300, the solenoid brake spring release valve 312 solenoid may not be actuated by the solenoid and, therefore, may be in its normally vented position depicted in FIG. 3. In this position, the spring release chamber 116 may be exhausted thereby allowing the brake spring 114 to press the brake pad 120 onto the friction disc 130.

The solenoid brake apply valve 314 may actuate when it receives a signal from the ECP brake system 300 indicating that the spring release chamber 116 may be exhausted. The solenoid brake apply valve 314 is depicted in a normally vented position which does not exhaust the spring release chamber 116. The solenoid brake apply valve 314 may be in such a position when the solenoid brake apply valve 314 solenoid does not have a signal. The solenoid brake apply valve 314 may receive a signal from the ECP brake system 300 that causes the solenoid brake apply valve 314 solenoid to actuate the solenoid brake apply valve 314 to exhaust the spring release chamber 116. For example, the ECP brake system 300 may send the signal to the solenoid brake apply valve 314 when the vehicle is parked. In such a state, the brake cylinder 110 may apply the brake cylinder pipe 170 pressure. Accordingly, the brake pad 120 is pressed onto the friction disc 130 by either the brake cylinder pipe 170 pressure and/or by the brake spring 114.

Similar to the pneumatic brake spring release valve 212 and the pneumatic brake apply valve 214, both the solenoid brake spring release valve 312 and the solenoid brake apply valve 314 may actuate when pressures in the ECP brake system 300 are sufficient. For example, the solenoid brake spring release valve 312 may actuate when the main reservoir pipe 240 pressure is sufficient for the ECP brake system 300 to provide enough fluid to the brake cylinder pipe 170 to hold the friction disc 130 during pressure fluctuations in the ECP brake system 300. Similarly, the solenoid brake apply valve 314 may not return to its normally vented state until the brake cylinder pipe 170 is below a pressure sufficient to hold the friction disc 130. The ECP auto brake module 310 depicted in FIG. 3 may, in some embodiments, be combined with a pneumatic brake system. Such a hybrid system is described in the following with reference to FIG. 4.

FIG. 4 shows a hybrid brake system 400 that includes a hybrid auto brake module 410 according to an embodiment. The hybrid auto brake module 410 is similar to the pneumatic brake module 210 and the ECP auto brake module 310 described with reference to FIGS. 2 and 3 with additional features related to hybrid ECP/pneumatic brake systems. The additional features include a release valve shuttle 412 that is fluidly coupled to the solenoid brake spring release valve 312 and the pneumatic brake spring release valve 212. The release valve shuttle 412 is also fluidly coupled with the spring release chamber 116 via the manual application valve 140. Also included in the hybrid auto brake module 410 is a release valve pilot valve 414 that is fluidly coupled with the pneumatic brake spring release valve 212 actuator port and the brake pipe 160 via the brake pipe inlet filter 222. The release valve pilot valve 414 is also fluidly coupled to the BP choke 224 and the BP check valve 226. A BP pilot valve 416 is fluidly coupled to the release valve pilot valve 414 actuator port and the brake pipe 160.

The release valve shuttle 412 may be a pneumatic shuttle valve although any suitable valve may be employed. The release valve shuttle 412 may fluidly couple the solenoid brake spring release valve 312 with the spring release chamber 116 via the solenoid brake apply valve 314. The release valve shuttle 412 may shuttle to couple either the pneumatic brake spring release valve 212 or the solenoid brake spring release valve 312 with the spring release chamber 116. For example, if the brake pipe 160 pressure actuates the pneumatic brake spring release valve 212, the shuttle may fluidly couple the pneumatic brake spring release valve 212 to the spring release chamber 116.

The release valve pilot valve 414 is depicted as a normally open 3/2

pneumatically actuated vented pneumatic valve although any appropriate valve may be employed. The release valve pilot valve 414 is depicted in an open position. In such a position, the release valve pilot valve 414 may fluidly couple the brake pipe 160 with the pneumatic brake spring release valve 212 actuator port. Accordingly, the pneumatic brake spring release valve 212 may be held in an open position by the brake pipe 160 pressure.

The BP pilot valve 416 is a vented 3/2 solenoid actuated pneumatic valve although any appropriate valve may be employed. As depicted, the BP pilot valve 416 exhausts the release valve pilot valve 414 actuator port. Accordingly, the release valve pilot valve 414 may remain in the normally open position. When the BP pilot valve 416 is actuated, for example, by an electrical signal, the release valve pilot valve 414 may fluidly decouple the release valve pilot valve 414 from the exhaust. Also, the BP pilot valve 416 may also exhaust the release valve pilot valve 414 so the pneumatic brake spring release valve 212 may return to its normally open position. The BP pilot valve 416 may be actuated by the signal to place the brake cylinder 110 in the redundant state. In the redundant state, the solenoid brake spring release valve 312 may be in the normally vented position so the solenoid brake spring release valve 312 may not fluidly couple the brake pipe 160 with the spring release chamber 116. Accordingly, the brake pipe 160 may not pressurize the spring release chamber 116.

Similar to the description of the pneumatic brake module 210 and the ECP auto brake module 310 with respect to FIGS. 2 and 3, the solenoid brake apply valve 314 and the pneumatic brake apply valve 214 may exhaust the spring release chamber 116 when the brake pipe 160 or the brake cylinder pipe 170 drops to below their respective actuating pressures, the ECP fails or sends a signal to the solenoid brake apply valve 314 or other event occur in the hybrid brake system 400.

The embodiments described above provide an auto brake module. As explain above the auto brake module may manage the brake cylinder 110 states. Accordingly, the brake cylinder 110 states may be less expensive to manage and may be more safely operated. For example, if the ECP brake systems fail, the brake cylinder 110 may be placed into a parked state thereby slowing down or stopping the vehicle. Similarly, fluid pressure drops in portions of the pneumatic brake systems may apply pressure to the brakes. When a failure occurs in, for example, the ECP portion of the hybrid brake system, the hybrid auto brake module may operate to place the brake cylinder 110 into a parked state.

The detailed descriptions of the above embodiments are not exhaustive descriptions of all embodiments contemplated by the inventors to be within the scope of the present description. Indeed, persons skilled in the art will recognize that certain elements of the above-described embodiments may variously be combined or eliminated to create further embodiments, and such further embodiments fall within the scope and teachings of the present description. It will also be apparent to those of ordinary skill in the art that the above-described embodiments may be combined in whole or in part to create additional embodiments within the scope and teachings of the present description.

Thus, although specific embodiments are described herein for illustrative purposes, various equivalent modifications are possible within the scope of the present description, as those skilled in the relevant art will recognize. The teachings provided herein can be applied to other vibrating meters, and not just to the embodiments described above and shown in the accompanying figures. Accordingly, the scope of the embodiments described above should be determined from the following claims.

Claims

We claim:

1. An auto brake module (210, 310, 410) in a brake system (200, 300, 400) with a friction disc (130), a brake pipe (160), a brake cylinder pipe (170), and a brake cylinder (110) having a brake spring (114), a spring release chamber (116) and a service brake chamber (118), wherein the brake cylinder pipe (170) is fluidly coupled to the service brake chamber (118), the auto brake module (210, 310, 410) comprising:

a brake spring release valve (212, 312) fluidly coupled to the spring release chamber (116) and the brake pipe (160); and

a brake apply valve (214, 314) fluidly coupled to the spring release chamber (116), wherein:

the brake spring release valve (212, 312) is adapted to fluidly couple the brake pipe (160) to the spring release chamber (116) and the brake apply valve (214, 314) is adapted to exhaust the spring release chamber (116).

2. The brake spring release valve (212, 312) of claim 1 is further adapted to fluidly couple the brake pipe (160) to the spring release chamber (116) when the brake pipe (160) pressure is over a brake spring release valve (212, 312) actuating pressure.

3. The brake spring release valve (212, 312) actuating pressure of claim 2 is a pressure sufficient to place the brake cylinder (110) in a released state.

4. The brake spring release valve (212, 312) actuating pressure of claim 2 is a pressure sufficient to ensure the brake system (200, 400) provides enough fluid to the brake cylinder pipe (170) to hold the friction disc (130) during pressure fluctuations in the brake system (200, 400).

5. The brake apply valve (214, 314) of claim 1 is further adapted to exhaust the spring release chamber (116) when the brake pipe (160) pressure and the brake cylinder pipe (170) pressure are below one or more brake apply valve (214, 314) actuating pressures.

6. The one or more brake apply valve (214, 314) actuating pressures of claim 5 are sufficient to hold the friction disc (130).

7. The auto brake module (210, 310, 410) of claim 1 further comprises a release choke (216) that is adapted to restrict a flow of fluid from the brake pipe (160) to the spring release chamber (116).

8. The auto brake module (210, 410) of claim 1 further comprises a BP choke (224) that is adapted to restrict a flow of the fluid from an actuator port on the brake apply valve (214).

9. The auto brake module (210, 410) of claim 1 further comprises an actuator port on the brake apply valve (214) and a BC BP pilot shuttle (230) adapted to fluidly couple the actuator port to the brake pipe (160) when the brake pipe (160) pressure is greater than the brake cylinder pipe (170) pressure and to the brake cylinder pipe (170) when the brake cylinder pipe (170) pressure is greater than the brake pipe (160) pressure.

10. The BC BP pilot shuttle (230) of claim 9 is further adapted to shuttle to couple the brake pipe (160) or the brake cylinder pipe (170) to the actuator port on the brake apply valve (214) when the brake pipe (160) pressure or the brake cylinder pipe (170) pressure is over a shuttle pressure.

11. A method of forming an auto brake module (210, 310, 410) for a brake system (200, 300, 400) with a friction disc (130), a brake pipe (160), a brake cylinder pipe (170), and a brake cylinder (110) having a brake spring (114), a spring release chamber

(116) and a service brake chamber (118), wherein the brake cylinder pipe (170) is fluidly coupled to the service brake chamber (118), the method comprising:

forming a brake spring release valve (212, 312) and fluidly coupling the brake spring release valve (212, 312) to the spring release chamber (116) and the brake pipe (160); and

forming a brake apply valve (214, 314) and fluidly coupling the brake spring release valve (212, 312) to the spring release chamber (116), wherein: the brake spring release valve (212, 312) is formed to fluidly couple the brake pipe (160) to the spring release chamber (116) and the brake apply valve (214, 314) is formed to exhaust the spring release chamber (116).

12. The forming the brake spring release valve (212, 312) of claim 11 further comprises forming the brake spring release valve (212, 312) to fluidly couple the brake pipe (160) to the spring release chamber (116) when the brake pipe (160) pressure is over a brake spring release valve (212, 312) actuating pressure.

13. The brake spring release valve (212, 312) actuating pressure of claim 12 is a pressure sufficient to place the brake cylinder (110) in a released state.

14. The brake spring release valve (212, 312) actuating pressure of claim 12 is a pressure sufficient to ensure the brake system (200, 400) provides enough fluid to the brake cylinder pipe (170) to hold the friction disc (130) during pressure fluctuations in the brake system (200, 400).

15. The forming the brake apply valve (214, 314) of claim 12 further comprises forming the brake apply valve (214, 314) to exhaust the spring release chamber (116) when the brake pipe (160) pressure and the brake cylinder pipe (170) pressure are below one or more brake apply valve (214, 314) actuating pressure.

16. The one or more brake apply valve (214, 314) actuating pressure of claim 15 are sufficient to hold the friction disc (130).

17. The forming the auto brake module (210, 310, 410) of claim 11 further comprises forming a release choke (216) to restrict a flow of fluid from the brake pipe (160) to the spring release chamber (116).

18. The forming the auto brake module (210, 410) of claim 11 further comprises forming a BP choke (224) to restrict a flow of the fluid from an actuator port on the brake apply valve (214).

19. The forming the auto brake module (210, 410) of claim 11 further comprises forming an actuator port on the brake apply valve (214) and forming a BC BP pilot shuttle (230) to fluidly couple the actuator port to the brake pipe (160) when the brake pipe (160) pressure is greater than the brake cylinder pipe (170) pressure and to the brake cylinder pipe (170) when the brake cylinder pipe (170) pressure is greater than the brake pipe (160) pressure.

20. The forming the BC BP pilot shuttle (230) of claim 19 further comprises forming the BC BP pilot shuttle (230) to shuttle to couple the brake pipe (160) or the brake cylinder pipe (170) to the actuator port on the brake apply valve (214) when the brake pipe (160) pressure or the brake cylinder pipe (170) pressure is over a BC BP pilot shuttle (230) pressure.

21. A method of automatically managing a brake cylinder (110) having a spring release chamber (116) and a service brake chamber (118) in a brake system (200, 300, 400) that has a friction disc (130), a brake pipe (160) and a brake cylinder pipe (170), comprising:

fluidly decoupling the spring release chamber (116) from an exhaust when the brake cylinder pipe (170) pressure is sufficient to hold the friction disc (130); and

fluidly coupling the a brake pipe (160) to the spring release chamber (116) when a pressure in the brake system (200, 400) is sufficient to provide enough fluid to the brake cylinder pipe (170) to hold the friction disc (130) during pressure fluctuations in the brake system (200, 400).