Patent Description:
A wide variety of electrohydraulic proportional pressure control valves are used to provide controlled pressure to working units, such as wheel brakes. Some typical valves are designed for use with an actuator, such as a pedal actuator, in which force is applied to by a user. These pressure control valves provide a linear output characteristic for pressure versus force applied by the user to the actuator.

Various applications require a deadband in travel of the pedal actuator before actuation of the brakes occurs. The deadband is useful to compensate for the operator resting their foot on the brake pedal. The deadband is also useful when combined with a rotary position sensor to provide regenerative braking of the vehicle at low actuations of the pedal actuator on electric vehicles.

Conventional reverse pedal modulation valves require the addition of springs to the underside of the pedal, external to the valve, to provide a deadband functionality. These conventional valves are expensive to implement and the springs are susceptible to oxidations or contamination from the environment.

Accordingly, it is desirable to provide an improved reverse modulation valve and a system including the same. Furthermore, other desirable features and characteristics will become apparent from the subsequent summary and detailed description and the appended claims, taken in conjunction with the foregoing technical field and background. <CIT> is related to to a control valve and, in particular, to a control valve for controlling multiple function in a fluid operated system. <CIT> discloses an evaporation fuel processing unit provided with a seal valve. <CIT> relates to a control of a hydraulic brake system, and more particularly to control of a hydraulic fluid pressure at wheel brakes in a hybrid-electric or battery-electric vehicle. <CIT> relates to a braking system for a vehicle to control a regenerative braking. <CIT> relates to a vehicle brake device boosted by a hydraulic pressure.

In one embodiment, a valve assembly is provided. The valve assembly includes a valve body defining a bore. The valve assembly further includes a pull rod disposed in the bore and defining a bolt cavity. The pull rod is moveable between a first pull rod position and a second pull rod position. The valve assembly further includes a bolt disposed in the bolt cavity and moveable with respect to the pull rod between a first bolt position and a second bolt position. The valve assembly further includes a spool disposed in the bore. The spool is operatively coupled to the pull rod to move between an energized position and a neutral position.

In this and other embodiments, the bolt is configured to receive a force from a user to move the bolt from the first bolt position to the second bolt position. The bolt is also configured to receive the force from the user to move the pull rod from the first pull rod position to the second pull rod position when the bolt is in the second bolt position.

In this and other embodiments, the valve assembly has a deadband state and an active state. The valve assembly may be in the deadband state when the bolt is moving between the first bolt position and the second bolt position. In the deadband state, movement of the bolt does not result in movement of the spool. In contrast, the valve assembly may be in the active state when the bolt is in the second bolt position. In the active state, movement of the bolt results in movement of the pull rod thereby resulting in movement of the spool.

It is believed that the valve assembly including the bolt and the return spring disposed within the pushrod provides an improved deadband functionality as compared to conventional valve assemblies including an external spring to provide deadband functionality. In particular, in various embodiments, by disposing the bolt and the return spring within the pushrod and configuring the bolt to be moveable relative to the pushrod, these components are isolated from wear or contamination resulting from the environment.

Other advantages of the disclosed subject matter will be readily appreciated, as the same becomes better understood by reference to the following detailed description when considered in connection with the accompanying drawings wherein:.

Except in the examples, or where otherwise expressly indicated, all numerical quantities in this description indicating amounts of material or conditions of reaction and/or use are to be understood as modified by the word "about" in describing the broadest scope of the invention. Practice within the numerical limits stated is generally preferred. Also, unless expressly stated to the contrary: percent, "parts of," and ratio values are by weight; the description of a group or class of materials as suitable or preferred for a given purpose in connection with the invention implies that mixtures of any two or more of the members of the group or class are equally suitable or preferred; description of constituents in chemical terms refers to the constituents at the time of addition to any combination specified in the description, and does not necessarily preclude chemical interactions among the constituents of a mixture once mixed; the first definition of an acronym or other abbreviation applies to all subsequent uses herein of the same abbreviation and applies mutatis mutandis to normal grammatical variations of the initially defined abbreviation; and, unless expressly stated to the contrary, measurement of a property is determined by the same technique as previously or later referenced for the same property.

It must also be noted that, as used in the specification and the appended claims, the singular form "a," "an," and "the" comprise plural referents unless the context clearly indicates otherwise. For example, reference to a component in the singular is intended to comprise a plurality of components.

Furthermore, there is no intention to be bound by any theory presented in the preceding background or the following detailed description.

A valve assembly is provided herein. In various embodiments, the valve assembly is suitable for controlling a working unit of a vehicle. A system for controlling a working unit of a vehicle is also provided herein. Non-limiting examples of suitable vehicles include off-highway vehicles.

<FIG> and <FIG> are cross-sectional plan views illustrating a non-limiting embodiment of a valve assembly <NUM>. In certain embodiments, the valve assembly <NUM> is further defined as a reverse modulation valve assembly. However, it is to be appreciated that the valve assembly <NUM> may be appropriate for any valve assembly wherein a pressure decrease actuates a working unit.

The valve assembly <NUM> includes a valve body <NUM> defining a bore <NUM>. The bore <NUM> may be manufactured as a through bore extending through the valve body <NUM>. It is contemplated that the bore <NUM> may also be configured as a blind bore. For purposes of clarification, the valve body <NUM> will be described as having a first body end <NUM> and a second body end <NUM>. The valve assembly <NUM> further includes a cap <NUM> coupled to the first body end <NUM>. The cap <NUM> may define a void <NUM> extending through the cap <NUM> to the bore <NUM>. The cap <NUM> may be threaded to facilitate coupling of the cap <NUM> to the valve body <NUM>.

The valve assembly <NUM> further includes a pull rod <NUM> disposed in the bore <NUM>. The pull rod <NUM> may extend through the void <NUM> of the cap <NUM>. The pull rod <NUM> has a first pull rod end <NUM> and a second pull rod end <NUM> opposite the first pull rod end <NUM>. The pull rod <NUM> defines a bolt cavity <NUM> extending through the first pull rod end <NUM> and a compensating spring cavity <NUM> extending through the second pull rod end <NUM>. The pull rod <NUM> includes a pull rod shoulder <NUM> extending laterally about the second pull rod end <NUM>. As will be described in greater detail below, the pull rod <NUM> is operatively coupled to a spool <NUM> to facilitate operation of the valve assembly <NUM>.

The pull rod <NUM> is moveable between a first pull rod position and a second pull rod position. Movement of the pull rod <NUM> to the first pull rod position is directed toward the second body end <NUM> and movement of the pull rod <NUM> to the second pull rod position is directed toward the first body end <NUM>. The valve assembly <NUM> further includes a biasing spring <NUM> exhibiting a biasing spring force on the pull rod <NUM> to bias the pull rod <NUM> toward the first pull rod position. In various embodiments, the biasing spring <NUM> is disposed about the pull rod <NUM> and abutting the pull rod shoulder <NUM> of the pull rod <NUM> and the cap <NUM> to bias the pull rod <NUM> toward the first pull rod position.

According to the invention, pull rod <NUM> includes a nut <NUM>. The nut <NUM> may be coupled to the first pull rod end <NUM>. In various embodiments, both of the nut <NUM> and the first pull rod end <NUM> may be threaded for facilitating coupling of the nut <NUM> and pull rod <NUM> together. The nut <NUM> may have a base <NUM> and a side <NUM> transverse to the base <NUM>. The nut <NUM> may define a hole <NUM> having a hole diameter. The hole <NUM> may be defined on the base <NUM> of the nut <NUM> and extend through the nut <NUM> to the bolt cavity <NUM>. The nut <NUM> may further define a slot <NUM> transverse to the hole <NUM>. The slot <NUM> may be defined on the side <NUM> of the nut <NUM>.

The valve assembly <NUM> further includes a bolt <NUM> disposed in the bolt cavity <NUM>. The bolt <NUM> may have a shaft portion <NUM> extending to a head portion <NUM>. The bolt <NUM> may have a bolt shoulder <NUM> spaced from the nut <NUM>. The bolt shoulder <NUM> may be defined by a joint of the shaft portion <NUM> and the head portion <NUM>. The bolt <NUM> may have a first bolt end <NUM> and a second bolt end <NUM> opposite the first bolt end <NUM> with the head portion <NUM> disposed at the second bolt end <NUM>.

The bolt <NUM> is moveable with respect to the pull rod <NUM> between a first bolt position and a second bolt position. In various embodiments, movement of the bolt <NUM> to the first bolt position is directed toward the second body end <NUM> and movement of the bolt <NUM> to the second bolt position is directed toward the first body end <NUM>. The valve assembly <NUM> further includes a return spring <NUM> exhibiting a return spring force on the bolt <NUM> to bias the bolt <NUM> toward the first bolt position. The return spring <NUM> is disposed about the bolt <NUM>, and between the nut <NUM> and the bolt shoulder <NUM> to bias the bolt <NUM> toward the first bolt position. In certain embodiments, the bolt <NUM> extends through the hole <NUM> and is moveable with respect to the nut <NUM>.

In various embodiments, the bolt <NUM> is configured to move to the second bolt position prior to the pull rod <NUM> moving to the second pull rod position due to a ratio of the return spring force of the return spring <NUM> and the biasing spring force of the biasing spring <NUM>. The return spring force of the return spring <NUM> may be less than the biasing spring force of the biasing spring <NUM> thereby resulting in the return spring <NUM> being at least partially compressed by movement of the bolt <NUM> prior to the biasing spring <NUM> being at least partially compressed by movement of the pull rod <NUM>.

With specific reference to <FIG>, in certain embodiments, the bolt <NUM> comprises a pin <NUM> configured to cooperate with the slot <NUM> of the nut <NUM> to limit movement of the bolt <NUM> with respect to the pull rod <NUM> between the first bolt position and the second bolt position. For example, as the bolt <NUM> moves from the first bolt position to the second bolt position, the pin <NUM> moves along the slot <NUM> toward the base <NUM> of the nut <NUM>. When the pin <NUM> contacts the base <NUM> of the nut <NUM>, the bolt <NUM> may be limited from moving any further with respect to the pull rod <NUM>. In these embodiments, the position at which the pin <NUM> limits movement of the bolt <NUM> may be defined as the second bolt position. It is to be appreciated that the size of the pin <NUM> or the slot <NUM> may be adjusted to increase or decrease the amount movement permitted by the bolt <NUM> before moving the pull rod <NUM> (i.e., deadband as will be described below).

With specific reference to <FIG>, in other embodiments, the bolt <NUM> comprises a shell <NUM> configured to cooperate with the nut <NUM> to limit movement of the bolt <NUM> with respect to the pull rod <NUM> between the first bolt position and the second bolt position. The shell <NUM> may have a shell diameter with the shell diameter being greater than the hole diameter of the hole <NUM>. For example, as the bolt <NUM> moves from the first bolt position to the second bolt position, the shell <NUM> moves with the bolt <NUM> toward the base <NUM> of the nut <NUM>. When the shell <NUM> contacts the base <NUM> of the nut <NUM>, the bolt <NUM> may be limited from moving any further with respect to the pull rod <NUM>. In these embodiments, the position at which the shell <NUM> limits movement of the bolt <NUM> may be defined as the second bolt position. It is to be appreciated that the length of the shell <NUM> may be adjusted to increase or decrease the amount movement permitted by the bolt <NUM> before moving the pull rod <NUM> (i.e., deadband).

In various embodiments, the bolt <NUM> is configured to receive a force from a user to move the bolt <NUM> from the first bolt position to the second bolt position. In these and other embodiments, the bolt <NUM> is also configured to receive the force from the user to move the pull rod <NUM> from the first pull rod position to the second pull rod position when the bolt <NUM> is in the second bolt position. The force may be provided to the bolt <NUM> by any apparatus understood in the art for actuating a valve including, but not limited to, a pedal actuator, a lever, and the like. For example, as the force is applied to the bolt <NUM> to move the bolt from the first bolt position to the second bolt position, the bolt <NUM> moves toward the first body end <NUM> of the valve body <NUM>. When the bolt <NUM> reaches the second bolt position, the bolt <NUM> directly or indirectly contacts the nut <NUM> and the bolt <NUM> continues to move toward the first body end <NUM> of the valve body <NUM> to move the pull rod <NUM> from the first pull rod position to the second pull rod position. In one exemplary embodiment (e.g. as shown in <FIG>), the bolt <NUM> indirectly contacts the nut <NUM> through the pin <NUM> to move the pull rod <NUM> from the first pull rod position to the second pull rod position. In another exemplary embodiment (e.g. as shown in <FIG>), the bolt <NUM> indirectly contacts the nut <NUM> through the shell <NUM> to move the pull rod <NUM> from the first pull rod position to the second pull rod position.

As introduced above, the valve assembly <NUM> further includes a spool <NUM>. The spool <NUM> is disposed in the bore <NUM> and operatively coupled to the pull rod <NUM> to move between an energized position and a neutral position. The valve assembly <NUM> may further include a first compensating spring <NUM> disposed between the pull rod <NUM> and the spool <NUM> for operatively coupling the pull rod <NUM> and the spool <NUM>. In various embodiments, the first compensating spring <NUM> is disposed in the compensating spring cavity <NUM>. The valve assembly <NUM> may further include a second compensating spring <NUM> disposed opposite the first compensating spring <NUM> for biasing against the first compensating spring <NUM>. In various embodiments, movement of the pull rod <NUM> from the first pull rod position to the second pull rod position results in movement of the spool <NUM> from the energized position to the neutral position. Valve assemblies including a spool for facilitating operation are well understood in the art.

With reference to <FIG>, in certain embodiments, the valve assembly <NUM> has a deadband state <NUM> and an active state <NUM>. The valve assembly <NUM> may be in the deadband state <NUM> when the bolt <NUM> is moving between the first bolt position and the second bolt position. In the deadband state <NUM>, movement of the bolt <NUM> does not result in movement of the spool <NUM>. In contrast, the valve assembly <NUM> may be in the active state <NUM> when the bolt <NUM> is in the second bolt position. In the active state <NUM>, movement of the bolt <NUM> results in movement of the pull rod <NUM> thereby resulting in movement of the spool <NUM>. It is believed that the valve assembly <NUM> including the bolt <NUM> and the return spring <NUM> disposed within bolt cavity <NUM> of the pushrod <NUM> provides an improved deadband functionality to the valve assembly as compared to conventional valve assemblies including an external spring to provide deadband functionality. In particular, in various embodiments, by disposing the bolt <NUM> and the return spring <NUM> within the bolt cavity <NUM> of the pushrod <NUM> and configuring the bolt <NUM> to be moveable relative to the pushrod <NUM>, the bolt <NUM> and the return spring <NUM> are isolated from wear or contamination resulting from the environment.

The deadband state <NUM> may be useful compensating for the user resting their foot on the pedal actuator. The deadband state <NUM> may also be useful to provide regenerative braking of the vehicle at low actuations of the pedal actuator on electric vehicles. In certain embodiments, the valve assembly <NUM> further includes a sensor (e.g. a rotary position sensor) adapted to determine position of the bolt <NUM> between the first bolt position and the second bolt position. In these and other embodiments, the sensor may activate the regenerative braking of the vehicle when the valve assembly <NUM> is in the deadband state <NUM>.

Non-embodiments of operation of the valve assembly <NUM> will now be described. The valve assembly <NUM> is utilized with a fluid source <NUM> (e.g., hydraulic pressure unit or hydraulic pump), a tank <NUM> (e.g., a hydraulic reservoir), and a working unit <NUM> (e.g., a hydraulic cylinder or wheel brake). In various embodiments, the fluid source <NUM> is configured to provide fluid force (e.g. hydraulic fluid pressure) to the valve assembly <NUM>. The valve body <NUM> defines a pressure port <NUM>, a work port <NUM>, and a tank port <NUM>. Each of the ports <NUM>, <NUM>, and <NUM> may be in fluid communication with the bore <NUM> of the valve body <NUM>. In certain embodiments, the ports <NUM>, <NUM>, and <NUM> provide connection locations for establishing fluid communication between the valve body <NUM> and the hydraulic pump <NUM>, the working unit <NUM>, and the tank <NUM>. Typical port connections include standard SAE straight threads or other configurations for allowing hoses or other conduits to be connected between the components.

The bore <NUM> may include a first annular surface <NUM> and a second annular surface <NUM>. These surfaces <NUM>, <NUM> may be utilized to provide fluid communication between the ports <NUM>, <NUM>, and <NUM>. In certain embodiments, the spool <NUM> includes a first annular portion <NUM> and a second annular portion <NUM>. The first annular portion <NUM> and the second annular portion <NUM> may be configured to cooperate with the first annular surface <NUM> and the second annular surface <NUM> of the bore <NUM>, respectively, for manipulating fluid communication between the ports <NUM>, <NUM>, and <NUM>. As introduced above, in various embodiments, when the pull rod <NUM> is in the first pull rod position, the valve assembly <NUM> is energized and the working unit <NUM> is deactivated by providing fluid communication between the pressure port <NUM> and the work port <NUM>. In these embodiments and other embodiments, when the pull rod <NUM> is in the second pull rod position, the valve assembly <NUM> is neutralized and the working unit <NUM> is activated by providing fluid communication between the work port <NUM> and the tank port <NUM>.

As introduced above, a system for controlling the working unit <NUM> is also provided herein. The system has the deadband state <NUM> and the active state <NUM>. The system includes a fluid source <NUM> configured to provide the fluid force. The system further includes the valve assembly <NUM> with the valve assembly <NUM> in fluid communication with the fluid source <NUM>. The valve assembly <NUM> includes the pull rod <NUM> defining the bolt cavity <NUM>. The pull rod <NUM> is moveable between the first pull rod position and the second pull rod position. The valve assembly <NUM> further includes the bolt <NUM> disposed in the bolt cavity <NUM> and moveable with respect to the pull rod <NUM> between the first bolt position and the second bolt position. The valve assembly <NUM> further includes the spool <NUM> operatively coupled to the pull rod <NUM> to move between an energized position and a neutral position.

The system further includes the working unit <NUM> in fluid communication with the valve assembly <NUM> and configured to deactivate in response to the fluid force. The system is in the deadband state <NUM> when the bolt <NUM> is between the first bolt position and the second bolt position. The system is in the active state <NUM> when the bolt <NUM> is in second bolt position.

In certain embodiments, the system further includes a pedal actuator operatively coupled to the bolt <NUM>. The pedal actuator is adapted to receive the force from the user to move the bolt <NUM> from the first bolt position to the second bolt position. The pedal actuator is also adapted to receive the force from the user to move the pull rod <NUM> from the first pull rod position to the second pull rod position when the bolt <NUM> is in the second bolt position. The system further includes a sensor adapted to monitor movement of the pedal actuator. Output from the sensor is used by the vehicle control system to do functions such as regenerative braking during the deadband state <NUM> of pull rod travel.

Although the invention has been described in connection with specific preferred embodiments, it should be understood that the invention as claimed should not be unduly limited to these specific embodiments. While at least one exemplary embodiment has been presented in the foregoing detailed description of the invention, it should be appreciated that a vast number of variations exist. It should also be appreciated that the exemplary embodiment or exemplary embodiments are only examples, and are not intended to limit the scope, applicability, or configuration of the invention in any way. Rather, the foregoing detailed description will provide those skilled in the art with a convenient road map for implementing an exemplary embodiment of the invention. It being understood that various changes may be made in the function and arrangement of elements described in an exemplary embodiment without departing from the scope of the invention as set forth in the appended claims.

Further, any ranges and subranges relied upon in describing various embodiments of the present invention independently and collectively fall within the scope of the appended claims, and are understood to describe and contemplate all ranges including whole and/or fractional values therein, even if such values are not expressly written herein. One of skill in the art readily recognizes that the enumerated ranges and subranges sufficiently describe and enable various embodiments of the present invention, and such ranges and subranges may be further delineated into relevant halves, thirds, quarters, fifths, and so on. As just one example, a range "of from <NUM> to <NUM>" may be further delineated into a lower third, i.e., from <NUM> to <NUM>, a middle third, i.e., from <NUM> to <NUM>, and an upper third, i.e., from <NUM> to <NUM>, which individually and collectively are within the scope of the appended claims, and may be relied upon individually and/or collectively and provide adequate support for specific embodiments within the scope of the appended claims. In addition, with respect to the language which defines or modifies a range, such as "at least," "greater than," "less than," "no more than," and the like, it is to be understood that such language includes subranges and/or an upper or lower limit. As another example, a range of "at least <NUM>" inherently includes a subrange of from at least <NUM> to <NUM>, a subrange of from at least <NUM> to <NUM>, a subrange of from <NUM> to <NUM>, and so on, and each subrange may be relied upon individually and/or collectively and provides adequate support for specific embodiments within the scope of the appended claims. Finally, an individual number within a disclosed range may be relied upon and provides adequate support for specific embodiments within the scope of the appended claims. For example, a range "of from <NUM> to <NUM>" includes various individual integers, such as <NUM>, as well as individual numbers including a decimal point (or fraction), such as <NUM>, which may be relied upon and provide adequate support for specific embodiments within the scope of the appended claims.

The present invention has been described herein in an illustrative manner, and it is to be understood that the terminology which has been used is intended to be in the nature of words of description rather than of limitation. Many modifications and variations of the present invention are possible in light of the above teachings. The present invention may be practiced otherwise than as specifically described within the scope of the appended claims. The subject matter of all combinations of independent and dependent claims, both single and multiple dependent, is herein expressly contemplated.

Claim 1:
A valve assembly (<NUM>), comprising:
a valve body (<NUM>) defining a bore (<NUM>);
a pull rod (<NUM>) disposed in the bore (<NUM>) and defining a bolt cavity (<NUM>), the pull rod (<NUM>) moveable between a first pull rod position and a second pull rod position;
a bolt (<NUM>) disposed in the bolt cavity (<NUM>) and moveable with respect to the pull rod (<NUM>) between a first bolt position and a second bolt position; and
a spool (<NUM>) disposed in the bore (<NUM>), the spool (<NUM>) operatively coupled to the pull rod (<NUM>) to move between an energized position and a neutral position,
characterised in that the pull rod (<NUM>) comprises a nut (<NUM>), the bolt (<NUM>) has a bolt shoulder (<NUM>) spaced from the nut (<NUM>), and a return spring (<NUM>) is disposed between the nut (<NUM>) and the bolt shoulder (<NUM>) with the return spring (<NUM>) exhibiting a return spring force on the bolt (<NUM>) to bias the bolt (<NUM>) toward the first bolt position.