CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims the benefit of U.S. Provisional Patent Application No. 63/418,352, filed on October 21, 2022, which is incorporated herein by reference in its entirety.

BACKGROUND

[0002] The present invention relates to pilot operated hydraulic valves and more particularly to electrically operated pilot valves and high flow control valves.

BRIEF SUMMARY

[0003] A control valve (e.g., an electrohydraulic proportional valve (EHPV)) can be a two-stage proportional valve with variable restriction to flow, wherein a smaller, solenoid operated pilot stage controls a larger, main poppet, by engaging a pilot seat formed in the main poppet. A relief valve may be a valve which will open at a certain pressure range to allow fluid to pass to a lower pressure chamber. Aspects of the present disclosure provide a system e.g., a valve system) that combines these two functions, by combining the poppet of the relief valve with a seat of the pilot stage of the control valve. Thus, a valve system according to the present disclosure can provide the capability to relive pressure increases due to thermal expansion of fluid in cylinder mounted, load-holding applications.

[0004] According to one aspect of the disclosure, a valve system for controlling pressure in a hydraulic system can include a first control valve that includes a body including a first control chamber, a drain passage, and a first seat positioned between a first port and a second port. A first poppet can be moveably disposed within the body and can be configured to engage and disengage the first seat to selectively couple the first port and the second port. The valve system can further include a first electrohydraulic pilot valve configured to control a flow of a fluid between the first control chamber and the drain passage. The first electrohydraulic pilot valve can include an inlet in fluid communication with the first control chamber, an outlet in fluid communication with the drain passage, a second seat between the inlet and the outlet, and a second poppet configured to move relative to the second seat to selectively couple the inlet and the outlet. The second poppet can include a passage extending between a second control chamber and the outlet. The valve system can further include a solenoid actuator configured to move the second poppet to move relative to the second seat to selectively couple the inlet and the outlet.

[0005] In some non-limiting examples, the first control valve and the first electrohydraulic pilot valve can be coupled between a load-holding side of a hydraulic actuator and a second control valve. A third valve can be coupled between the load-holding side of the hydraulic actuator and a tank and can be configured to relief pressure from the load-holding side of the hydraulic actuator to the tank. A high pressure side of a control element of the third valve can reference the loadholding side of the hydraulic actuator and a low pressure side of the control element can be coupled to a spring. The low pressure side of the control element can be referenced to the second control valve, directly to the tank, and/or to atmosphere.

[0006] In some non-limiting examples, the third valve can be configured as a relief valve that can be coupled in parallel with the first control valve and the first electrohydraulic pilot valve between the load-holding side of the hydraulic actuator and the tank. In some non-limiting examples, the third valve can be configured as a sequence valve that can be coupled between the first control valve and the electrohydraulic pilot valve, to be in parallel with the electrohydraulic pilot valve. The third valve can be configured to close below a threshold pressure of the hydraulic actuator, and wherein the third valve can be configured to open at or above the threshold pressure of the hydraulic actuator.

[0007] In some non-limiting examples, the valve system can further include a second electrohydraulic pilot valve that can be configured to provide regenerative flow when a non-loadholding side of the hydraulic actuator is at a lower pressure than the load-holding side. The second electrohydraulic pilot valve can be coupled between the load-holding side of the hydraulic actuator and the non-load-holding side of the hydraulic actuator, and/or the second electrohydraulic pilot valve can be coupled between the non-load-holding side of the hydraulic actuator and the second control valve. The second electrohydraulic pilot valve can be coupled between the load-holding side of the hydraulic actuator and at least one of the first electrohydraulic pilot valve and the first control valve. A check valve can be coupled between the second electrohydraulic pilot valve and the hydraulic actuator to provide unidirectional flow from the load-holding side of the hydraulic actuator to the non-load-holding side of the hydraulic actuator. The check valve can be disposed within regeneration control valve that is coupled between the load-holding side of the hydraulic actuator and the second electrohydraulic pilot valve. [0008] In some non-limiting examples, the solenoid actuator can be configured move a third poppet to selectively block and unblock fluid communication between the second control chamber and the passage to change the pressure in the second control chamber and move the second poppet. The first electrohydraulic pilot valve can further include a fourth poppet movably disposed in the passage. The fourth poppet can define a pilot passage that is selectively blocked and unblocked by the third poppet.

[0009] The foregoing and other aspects and advantages of the disclosure will appear from the following description. In the description, reference is made to the accompanying drawings, which form a part hereof, and in which there is shown by way of illustration a preferred configuration of the disclosure. Such configuration does not necessarily represent the full scope of the disclosure, however, and reference is made therefore to the claims and herein for interpreting the scope of the disclosure.

BRIEF DESCRIPTION OF THE DRAWINGS

[0010] The disclosure will be better understood, and features, aspects, and advantages will become apparent when consideration is given to the following detailed description thereof. Such detailed description references to the following drawings.

[0011] FIG. 1 is a cross sectional view of a hydraulic control valve assembly, according to aspects of the disclosure.

[0012] FIG. 2 is a detail cross sectional view of an electrohydraulic pilot valve in the hydraulic control valve of FIG. 1.

[0013] FIG. 3 is a detail schematic view of a non-limiting example of a hydraulic system including an electrohydraulic pilot valve and a relief valve, according to aspects of the disclosure. [0014] FIG. 4 is a detail schematic view of the hydraulic system of FIG. 3 with the relief valve connected to an external tank.

[0015] FIG. 5 is a detail schematic view of the hydraulic system of FIG. 3 with the relief valve connected to an atmospheric valve.

[0016] FIG. 6 is a detail schematic view of the hydraulic system of FIG. 4 including a sequence valve instead of a relief valve.

[0017] FIG. 7 is a detail schematic view of the hydraulic system of FIG. 6 with the sequence valve connected to an atmospheric valve. [0018] FIG. 8 is a detail schematic view of another non-limiting example of a hydraulic system including a main control valve, an electrohydraulic pilot valve, and a relief valve, according to aspects of the disclosure.

[0019] FIG. 9 is a detail schematic view of the hydraulic system of FIG. 8 with the relief valve connected to an external tank.

[0020] FIG. 10 is a detail schematic view of the hydraulic system of FIG. 8 with the relief valve connected to an atmospheric valve.

[0021] FIG. 11 is a detail schematic view of the hydraulic system of FIG. 9 including a sequence valve instead of a relief valve.

[0022] FIG. 12 is a detail schematic view of the hydraulic system of FIG. 11 with the sequence valve connected to an atmospheric valve.

[0023] FIG. 13 is a detail schematic view of yet another non-limiting example of a hydraulic system including a regeneration pilot valve and the pilot valve of FIG. 1, according to aspects of the disclosure.

[0024] FIG. 14 is a detail schematic view of the hydraulic system of FIG. 13 and further including and the main control valve of FIG. 1.

[0025] FIG. 15 is a detail schematic view of the hydraulic system of FIG. 14 and further including a regeneration control valve.

DETAILED DESCRIPTION

[0026] Before any aspects of the present disclosure are explained in detail, it is to be understood that the present disclosure is not limited in its application to the details of construction and the arrangement of components set forth in the following description or illustrated in the following drawings. The present disclosure is capable of other configurations and of being practiced or of being carried out in various ways. Also, it is to be understood that the phraseology and terminology used herein is for the purpose of description and should not be regarded as limiting. The use of “including,” “comprising,” or “having” and variations thereof herein is meant to encompass the items listed thereafter and equivalents thereof as well as additional items. Unless specified or limited otherwise, the terms “mounted,” “connected,” “supported,” and “coupled” and variations thereof are used broadly and encompass both direct and indirect mountings, connections, supports, and couplings. Further, “connected” and “coupled” are not restricted to physical or mechanical connections or couplings and may also indicate fluid couplings. [0027] As used herein, unless otherwise defined or limited, ordinal numbers are used herein for convenience of reference based generally on the order in which particular components are presented for the relevant part of the disclosure. In this regard, for example, designations such as “first,” “second,” etc., generally indicate only the order in which the relevant component is introduced for discussion and generally do not indicate or require a particular spatial arrangement, functional or structural primacy or order.

[0028] The following discussion is presented to enable a person skilled in the art to make and use aspects of the present disclosure. Various modifications to the illustrated configurations will be readily apparent to those skilled in the art, and the generic principles herein can be applied to other configurations and applications without departing from aspects of the present disclosure. Thus, aspects of the present disclosure are not intended to be limited to configurations shown but are to be accorded the widest scope consistent with the principles and features disclosed herein. The following detailed description is to be read with reference to the figures, in which like elements in different figures have like reference numerals. The figures, which are not necessarily to scale, depict selected configurations and are not intended to limit the scope of the present disclosure. Skilled artisans will recognize the non-limiting examples provided herein have many useful alternatives and fall within the scope of the present disclosure.

[0029] A wide variety of machines include moveable components which can be operated by a hydraulic actuator, which can be controlled by controlling a flow of fluid through hydraulic control valves. For example, hydraulic control valves can be used to control and direct a flow of fluid through a hydraulic system to move actuators and loads, which in turn can be used to operate a myriad of functions in a machine. Conventional hydraulic control valves can include a set of solenoid operated pilot control valves to control the flow of fluid through a pilot passage in a main valve poppet. Opening the pilot passage releases pressure in a control chamber, thereby allowing the main valve poppet to move away from a valve seat and create a path between an inlet and an outlet of the valve.

[0030] When an operator desires to move a component in a machine, an input device can be operated to produce electrical signals that are applied to one or more solenoid valves for a respective hydraulic actuator (e.g., a motor and/or a cylinder-piston combination associated with the machine component). In the case of a hydraulic cylinder, by varying the degree to which the solenoid valves are opened, the rate of the flow into the cylinder chamber can be varied, thereby moving the piston at proportionally different speeds. Additionally, operation of the solenoid can be used to provide load-holding capabilities, including regenerative functions where fluid can be metered from a load-holding side of the cylinder to the other.

[0031] Correspondingly, some hydraulic systems utilize flexible pipework (e.g., flexible hoses) to direct fluid flow through the system characteristics. Flexible pipework is often chosen for use in hydraulic systems because it is easy to install and maintain, and it also provides vibration absorption qualities to increase the stability of hydraulic systems. However, flexible pipework may burst due to a variety of factors, including high pressure, abrasions and wear, kinking, chemical degradation, impact damage, and fatigue over time. Such failures can pose safety risks to users and may also cause power loss in hydraulic machines, which can then lead to downtime and decreased production efficiency. Moreover, such failure can result in high repair and/or replacement costs on manufacturers.

[0032] Thus, there exists a need for hydraulic control valves with increased protection from hose burst failure. A hydraulic control valve assembly according to the present disclosure can include a main control valve with a high flow poppet and an electrohydraulic pilot valve to provide additional protection from hose burst failure and control local metering to a hydraulic actuator. When the control valve receives electrical signals from an input device, a pilot pin in the pilot valve can be actuated to open a pilot passage and allow fluid to flow therethrough, which in turn provides metering of fluid in the high flow poppet. The control valve can also incorporate relief and/or sequence valve protection to incorporate relief and/or sequence valve protection to relieve high pressure in the hydraulic actuator caused by thermal or other effects. Relief and/or sequence valve protection can further include, for example, venting, tank referencing, and/or atmosphere referencing.

[0033] In some aspects, a main control valve can include a body with a bore formed therein to slidably receive a main poppet therein. The body can also include a plurality of ports (e. ., a first port and a second port) that can be connected to inlets and or outlets of a control valve assembly and that can partially define a flow path in the main control valve. For example, fluid may flow between the plurality of ports, and the main poppet can be moved to close the flow path between the ports to selectively meter the flow of fluid through the main control valve. In addition, the body can include a first control chamber located on a remote side of the main poppet, and the and the main poppet can be moved to close a flow path formed between the plurality of ports and the first control chamber to further meter the flow of fluid through the main control valve. The first control chamber may be in fluid communication with an inlet of an electrohydraulic control valve, as will be discussed below in greater detail. In some aspects, the main poppet can be biased in a closed position using a main spring disposed in the main bore of a body of a main control valve, and/or movement of the main poppet can be determined by a relationship of pressures between the plurality of ports and/or the first control chamber.

[0034] Referring now to FIG. 1, a non-limiting example of a control valve assembly 100 can include a main control valve 104 (e.g., a first control valve) coupled to a pilot valve 108 (e.g., an electrohydraulic pilot valve). The control valve assembly 100 can be arranged in a hydraulic system so as to control metering of a flow of fluid through the hydraulic system. It is contemplated that the control valve assembly 100 may be compatible with a variety of different fluids that are commonly used in hydraulic systems. Moreover, it will be understood that the control valve assembly 100 can be coupled to a variety of other components within a hydraulic system, and the control valve assembly 100 can include other components in addition to the main control valve 104 and the pilot valve 108, as will be discussed below in greater detail.

[0035] In some aspects, the main control valve 104 can be configured as a high flow control valve that is configured to accommodate high volumes of fluid. To that end, the main control valve 104 can include a body 112 that defines a first port 120 and a second port 124 that can be in fluid communication with one another via a first bore 128 (e.g, a primary bore). Each of the first port 120 and the second port 124 can be configured to couple to various components of the hydraulic system to control the flow of fluid therein. For example, the first port 120 can be configured to couple to a pump or tank and the second port 124 can be configured to couple to an actuator (e.g, a hydraulic cylinder configured to manipulate a load).

[0036] To control fluid flow in a main control valve, and thus the hydraulic system and valve assembly, a control element can be disposed within a valve body to selectively couple a first port and a second port. In the illustrated non-limiting example, the body 112 can further define a first seat 134 (e.g., a valve seat) between the first port 120 and the second port 124 (e.g. , within the first bore 128). A first poppet 136 (e.g., a primary poppet) can be moveably disposed within the first bore 128 to selectively engage and disengage the first seat 134. Accordingly, when the first poppet 136 (e.g, a first end 140 thereof) is engaged with the first seat 134 (e.g, in a first configuration), the first poppet 136 can block flow from the first port 120 to the second port 124, and when the first poppet 136 is disengaged from the first seat 134 (e.g, in a second configuration), the first poppet 136 can allow flow from the first port 120 to the second port 124. [0037] Movement of the first poppet 136 can be controlled based, at least in part, on hydraulic pressure within the system. For example, as illustrated in FIG. 1, the first poppet 136 and first bore 128 can collectively define a first control chamber 130. The first control chamber 130 can be formed opposite about the first seat 134, relative to the first poppet 136 (e.g., at a second end 148 thereof), so that a force balance caused by the pressures in the first port 120 and first control chamber 130 cause movement of the first poppet 136. In some cases, the main control valve 104 may be configured as a normally closed valve, and may include a first spring 158 (e.g., a main spring) configured to bias the first poppet 136 into engagement with the first seat 134. Accordingly, a relationship of pressures between the first port 120 and the first control chamber 130 can determine the position of the first poppet 136.

[0038] To provide pressure to the first control chamber 130, the first control chamber 130 can be coupled to the first port 120. In some cases, as in the illustrated non-limiting example, the first control chamber 130 can be coupled to the first port 120 via the first poppet 136. Specifically, the first poppet 136 can define a first passage 144 that extends through the first poppet 136 from the first port 120 to the first control chamber 130 to provide a path for fluid flow therebetween. Accordingly, the pressure within the first control chamber 130 can be adjustable to control movement of the first poppet 136, as described in greater detail below.

[0039] In some cases, the main control valve 104 may optionally include a check valve 156 to provide unidirectional flow from the first port 120 to the first control chamber 130. As shown in the illustrated non-limiting example, the check valve 156 can be positioned within the first passage 144 of the first poppet 136. More specifically, the check valve 156 can be positioned at one end of the first passage 144 (e.g., an end of the first passage 144 distal with respect to the first seat 134, in the first poppet 136). The first check valve 156 may permit fluid to flow only from the first port 120 into the first control chamber 130 but may prevent fluid from flowing from the first control chamber 130 to the first port 120. Put another way, the first check valve 156 may prevent bidirectional flow through the main control valve 104. In some examples, the first check valve 156 only blocks the first passage 144 when a sufficient pressure threshold (e.g., a pressure differential between the first control chamber 130 and first port 120) is reached. In some cases, a spring 164 can be included to control movement of the check valve 156.

[0040] As discussed above, a main control valve can be operated by controlling pressure in a main control chamber. In some cases, the pressure in the main control chamber can be controlled using a pilot valve (e.g. , an electrohydraulic pilot valve), which selectively couple the main control chamber to a lower pressure port (e.g., a second port of the valve). Use of a pilot valve may provide more precise control of the flow metering in a hydraulic system in comparison to that available using a high flow valve by itself, while also reducing energy consumption requirements of hydraulic systems. This in turn can increase the safety of hydraulic systems and reduce the possibility of hose burst failure. In some aspects, a hydraulic pilot valve can receive a flow of fluid from the main control chamber in a main control valve and can meter the flow of fluid using solenoid actuators to selectively open and close openings within the pilot valve. Thus, a pilot valve according to the present disclosure can provide precise metering of fluid through a control valve assembly, which in turn can enhance the stability and safety of the control valve assembly.

[0041] With additional reference to FIG. 2, a pilot valve 108 can be positioned along a drain passage 176 extending between the control chamber 130 and the second port 124 (see FIG. 1). The pilot valve 108 can be configured to selectively couple the control chamber 130 and the second port 124 (see FIG. 1) (e.g., to control flow through the drain passage 176) to adjust the pressure in the control chamber 130 (see FIG. 1). For example, the pilot valve 108 can be configured to block the drain passage 176 so that fluid entering the control chamber 130 from the first port 120 cannot drain to the second port 124 (see FIG. 1). This causes pressure to increase within the control chamber 130, which moves the first poppet 136 into engagement with the first seat 134, blocking flow between the first port 120 and the second port 124 through the first seat 134 (see FIG. 1). Additionally, the pilot valve 108 can be configured to open the drain passage 176 so that fluid entering the control chamber 130 from the first port 120 drains to the second port 124 (see FIG. 1). This causes pressure to decrease within the control chamber 130, which moves the first poppet 136 to disengage from the first seat 134, allowing flow between the first port 120 and the second port 124 through the first seat 134 (see FIG. 1).

[0042] In some cases, the pilot valve 108 may itself be a pilot-operated valve that includes a valve sleeve 180 (e g., a second valve body) defining an inlet 184 in communication with the control chamber 130 (see FIG. 1) and an outlet 188 in communication with second port 124 (see FIG. 1), which can be in fluid communication with one another via a second bore 192. As illustrated, the inlet 184 can be formed in a side of the valve sleeve 180 and the outlet 188 can be formed in another side of the valve sleeve 180 (e.g., a nose side of the valve sleeve 180). Thus, depending on the application, the pilot valve 108 can be configured for nose-to-side metering, side- to-nose metering, or both. [0043] Additionally, a second seat 196 can be formed in the second bore 192 between the inlet 184 and the outlet 188. A second poppet 200 (e.g., a poppet assembly) can be moveably disposed within the second bore 192 to selectively engage and disengage the second seat 196, thereby allowing the flow of fluid between the inlet 184 and the outlet 188 to be selectively controlled (z. e. , metered). To that end, the second poppet 200 can define a nose 204 configured to engage the second seat 196 in a closed state to decouple the inlet 184 from the outlet 188 (e.g., to block the control chamber 130 from the second port 124), and to disengage the second seat 196 in an open state to couple the inlet 184 to the outlet 188 (e.g., to connect the control chamber 130 with the second port 124). The nose 204 can have a cylindrical or frustoconical profile that contacts and seals a correspondingly shaped surface on the second seat 196 when the pilot valve 108 is in the closed state. In some cases, the pilot valve 108 can be a normally closed valve and may include a spring configured to bias the second poppet 200 into engagement with the second seat 196.

[0044] Further, an orifice 210 can couple the inlet 184 to a pilot or second control chamber 208 formed in the second bore 192 by the second poppet 200, opposite the second seat 196. The orifice 210 allows fluid to flow from the first control chamber 130 (see FIG. 1) into the second control chamber 208, which can increase pressure in the second control chamber 208 to engage the second poppet 200 with the second seat 196. Correspondingly, the second poppet 200 can include a second passage 212 configured to couple the second control chamber 208 to the outlet 188. The second passage 212 allows fluid to flow from the second control chamber 208 to the second port 124 (see FIG. 1), which can decrease pressure in the second control chamber 208 to disengage the second poppet 200 from the second seat 196. Thus, by controlling the pressure in the second control chamber 208, the forces associated with pressure differential between the second control chamber 208 and the second port 124 (see FIG. 1) can move the second poppet 200 to selectively couple the first control chamber 130 to the second port 124 (see FIG. 1).

[0045] To control the pressure in the second control chamber 208, the pilot valve 108 can include a third poppet 216 (e.g., a pin) that can move to selectively engage and disengage a third poppet seat 220 formed by the second poppet 200, within the second control chamber 208 at the second passage 212. Put another way, the third poppet 216 can be actuated to selectively block and unblock fluid communication between the second control chamber 208 and the second passage 212 (i.e., the second control chamber 208 and the outlet 188). In some cases, a pilot poppet 222 (e.g., a fourth poppet) can be moveably disposed the second passage 212 and can define a pilot passage 226 that can be blocked by the third poppet 216. It is understood that pilot passage 226 can be considered to form part of the second passage 212.

[0046] In some cases, the third poppet 216 can be moved by an actuator. In the illustrated nonlimiting example, the pilot valve 108 includes a solenoid actuator 224 that can include an electromagnetic coil 228 and an armature 232, which can be configured to move the third poppet 216. The armature 232 can be moveably disposed within the second bore 192 and can be biased toward the second poppet 200 by a spring 236. In some examples, the spring 236 can exert a force on the armature 232 that can be varied by an adjusting the position of a screw (not shown) which can be secured within the second bore 192. Further, the electromagnetic coil 228 can be coupled to the valve sleeve 180. The coil 228 can be selectively energized to produce a magnetic field with acts on the armature 232, such that the armature 232 can be actuated away from second poppet 200 in response to the magnetic field generated by the coil 228. Correspondingly, the armature 232 may be actuated towards the second poppet 200 by the spring 236 in response to turning off the electromagnetic coil 228 or producing a different magnetic field using the electromagnetic coil 228 (e.g., a differently charged magnetic field).

[0047] For example, the third poppet 216 can engage the third poppet seat 220 when the solenoid actuator 224 is in a de-energized state (e.g., in the case of a monostable solenoid valve). Correspondingly, the third poppet 216 can be disengaged from the third poppet seat 220 when the solenoid actuator 224 is in an energized state. In this way, the solenoid actuator 224 can be used to precisely meter the flow of fluid in the pilot valve 108, which in turn allows the flow of fluid in the main control valve 104 and the control valve assembly 100 (see FIG. 1) to be regulated. As a result, movement of the armature 232 engages and disengages the third poppet 216 from the third poppet seat 220 to selectively couple the second control chamber 208 to the outlet 188, which in turn adjusts the pressure in the first control chamber 130 to move the first poppet 136 (see FIG. 1). [0048] Therefore, a pilot valve can be used to proportionally control, or modulate, the rate at which fluid is released from a primary control chamber and thus the distance that a main poppet may move away from a corresponding valve seat. This in turn can regulate the flow rate through the control valve assembly. Accordingly, the use of an electrohydraulic pilot valve can enable control of a separate, main poppet that governs high flow rates through the control valve assembly. [0049] As discussed above, a control valve assembly can be arranged within a hydraulic system to control and direct hydraulic fluid therethrough to move actuators and loads while regulating the pressure within the hydraulic system. For example, a control valve assembly according to the present disclosure can be connected to e.g., in fluid communication with) a hydraulic actuator and another control valve in a hydraulic system. In addition, it is contemplated that a control valve assembly can be connected to a variety of other components in a hydraulic system, include relief valves, sequencing valves, external tanks, atmospheric valves, and/or any combination thereof. Further, it is contemplated that a control valve assembly can be connected to other components in a hydraulic system using any suitable technique, including, for example, via rigid pipes, direct flange mountings, valve elements machined in a cylinder housing, flexible pipework, or any combination thereof.

[0050] In some examples, a control valve assembly can be connected to a load-holding side of a hydraulic actuator, and another control valve such that fluid can be relived from the load-holding side of the hydraulic actuator, through the control valve assembly, and outward to the other control valve downstream in the hydraulic system. Correspondingly, a hydraulic system can be configured to provide pressure relief that can prevent an overpressure condition of the hydraulic system, and in particular, an overpressure condition during a load-holding operation. As described in greater detail below, such systems can include a relief valve or a sequence valve that can be connected in various ways to provide pressure relief, in particular pressure relief due to thermal expansion of the hydraulic fluid. Moreover, relief and/or sequence valves can be configured to protect against over pressure of a hydraulic actuator caused by mechanical forces or loads in the hydraulic system during operation of the hydraulic actuator (e.g., dynamic loading of the hydraulic actuator during operation).

[0051] Referring now to FIG. 3, a non-limiting example of a hydraulic system 300 (e.g., a valve system configured to provide load holding and hose burst protection) can include a control valve assembly 304 that can be connected to a hydraulic actuator 308 and a second or primary control valve 312. Specifically, the control valve assembly 304 can be positioned between the hydraulic actuator 308 and the primary control valve 312 such that the hydraulic actuator 308 and the primary control valve 312 are fluidly connected to one another through the control valve assembly 304. The hydraulic actuator 308 may include a load-holding side 316 (z.e., a side of a cylinder holding a load against gravity). For example, the hydraulic actuator 308 may include a rod 320 and a head 322, either of which may serve as the load-holding side 316 of the hydraulic actuator 308 depending on the particular application. Accordingly, the control valve assembly 304 can be connected to both the rod 320 and the head 322. Thus, it will be understood that the arrangement illustrated in FIG. 3 of the control valve assembly 304 is a non-limiting example in which the control valve assembly 304 is directly connected to the rod 320 that is acting as the loadholding side 316 of the hydraulic actuator 308, and that the control valve assembly 304 may also be directly coupled to the head 322 in some examples. In some aspects, a side of the hydraulic actuator 308 other than the load-holding side 316. can be directly coupled to the primary control valve 312.

[0052] The connection between the control valve assembly 304 and the hydraulic actuator 308 can allow fluid that exits the load-holding side 316 of the hydraulic actuator 308 to be directed through the control valve assembly 304 before exiting the hydraulic system 300 to the primary control valve 312. As discussed above, the control valve assembly 304 can have a variety of different configurations to effectively regulate pressure within the hydraulic system 300 and/or prevent unintended motion due to the failure (bursting) of a hose between the control valve assembly 304 and the primary control valve 312. In one non-liming example, the control valve assembly 304 includes an electrohydraulic valve (c. ., the pilot valve 108 discussed above for FIG. 1). In particular, the inlet 184 of the pilot valve 108 can be configured to receive fluid from the load-holding side 316 of the hydraulic actuator 308, and the outlet 188 can be configured to receive fluid from the inlet 184 and direct fluid to the primary control valve 312 or another component in the hydraulic system 300, as will be discussed below in greater detail. The pilot valve 108 can generally include a plurality of poppets (e.g., a poppet assembly) that may be actuated between different positions via the solenoid actuator 224 to selectively open and close openings (not shown) in the pilot valve 108. This in turn allows fluid to be selectively metered through the pilot valve 108 as discussed above.

[0053] In some examples, a control valve assembly can further include a third valve in addition to a main control valve and/or a pilot valve. For example, the third valve can be configured to provide protection against high pressures. By providing pressure relief to a hydraulic system, the use of a third valve in a hydraulic system limits the pressure in the load-holding side 316 of the hydraulic actuator 308 and increases the longevity of the other valves and components in the system. In some aspects, a third valve in a control valve assembly can be a relief valve, a sequence valve, or any combination thereof. It is contemplated that any suitable relief valve and/or sequence valve may be added to a control valve assembly.

[0054] In some non-limiting example, a relief or sequence valve can be referenced to another part of a control valve. For example, still referring to FIG. 3, the control valve assembly 304 can further include a relief valve 344. The relief valve 344 can be arranged in parallel with the pilot valve 108 such that an upstream side of the relief valve 344 is connected to the load-holding side 316 of the hydraulic actuator 308 (e.g., between the hydraulic actuator 308 and the pilot valve 108), and a downstream side of the relief valve 344 is connected to the primary control valve 312. The relief valve 344 can be a normally closed valve, with a first end (e.g., a low pressure reference) of a flow control element (e.g., a spool) being coupled to a spring 345 and referenced to a downstream connection of the relief valve 344 (e.g., the primary control valve 312), while a second end (e.g., a high pressure reference) of the flow control element is referenced to an upstream connection of the relief valve 344 (e.g., the load-holding side 316 of the hydraulic actuator 308). Accordingly, below a threshold pressure of the hydraulic actuator 308, the force on the first end can overcome the force on the second end to bias the relief valve 344 closed. Conversely, at or above the threshold pressure of the hydraulic actuator 308, the force on the second end can overcome the force on the first end to bias the relief valve 344 open and relieve pressure within the hydraulic actuator 308. Thus, the relief valve 344 can provide a relief path that may be independent of the pilot valve 108. Correspondingly, it is appreciated that the primary control valve 312 may include an open connection to a tank (e.g, tank 352, see FIG. 4) to allow fluid to drain through the relief valve 344. In some examples, the relief valve 344 can be arranged within the pilot valve 108 (e.g., in a poppet in the pilot valve 108).

[0055] In other non-limiting examples, a relief valve can be connected to one or more external reference components (i.e., not internal to the control valve assembly) to further provide overpressure protection of a hydraulic system. For example, referring to FIG. 4, the relief valve 344 can be referenced directly to a tank 352 of the hydraulic system 300. As illustrated, the downstream side of the relief valve 344 can be connected directly to the tank 352. Additionally, the first end of the flow control element (e.g., a spool) can be coupled to the spring 345 and referenced to the tank 352, while a second end of the flow control element can be referenced to the load-holding side 316 of the hydraulic actuator 308. Below a threshold pressure of the hydraulic actuator 308, the force on the first end can overcome the force on the second end to bias the relief valve 344 closed. Conversely, at or above the threshold pressure of the hydraulic actuator 308, the force on the second end can overcome the force on the first end to bias the relief valve 344 open and relieve pressure within the hydraulic actuator 308. Thus, fluid can be directed directly to the tank 352 from the relief valve 344 during an overpressure condition.

[0056] Referring now to FIG. 5, in some non-limiting examples, a relief valve can be referenced to the atmosphere. It is an advantage that an atmospheric vent can be used in a hydraulic system to provide enhanced pressure relief and increase the efficiency of hydraulic systems. Moreover, atmospheric vents may be retrofitted on existing hydraulic systems, meaning that hydraulic systems can easily be modified to include atmospheric vents. This is particular advantageous for manufacturers who wish to update hydraulic systems to comply with increasingly stringent safety regulations without purchasing entirely new machinery or making modification requiring extensively long downtimes. Thus, using an atmospheric vent in a control valve assembly can also decrease maintenance and repair costs while providing an effective way to regulate pressure in hydraulic systems, both new and existing.

[0057] For example, similar to FIG. 3, the relief valve 344 can be arranged in parallel with the pilot valve 108 such that an upstream side of the relief valve 344 is connected to the load-holding side 316 of the hydraulic actuator 308 (e.g, between the hydraulic actuator 308 and the pilot valve 108), and a downstream side of the relief valve 344 is connected to the primary control valve 312. However, the first end of the flow control element (e.g., a spool) can be coupled to the spring 345 and referenced to the atmosphere 356, and the second end of the flow control element is referenced to the load-holding side 316 of the hydraulic actuator 308. A filter or other vent 360 can be provided between the atmosphere and the first end of the flow control element of the relief valve 344. Thus, below a threshold pressure of the hydraulic actuator 308, the force on the first end can overcome the force on the second end to bias the relief valve 344 closed. Conversely, at or above the threshold pressure of the hydraulic actuator 308, the force on the second end can overcome the force on the first end to bias the relief valve 344 open and relieve pressure within the hydraulic actuator 308.

[0058] In some cases, a sequence valve may be used in place of a relief valve to relief pressure using various low pressure references. For example, FIGS. 6 and 7 illustrate the hydraulic system 300 with a sequence valve 348 configured to relieve pressure at a load-holding side of the hydraulic actuator 308. The sequence valve 348 is connected in series with the pilot valve 108 such that upstream side of the sequence valve 348 is coupled to the hydraulic actuator 308 via the second control chamber 208 of the pilot valve 108 (e.g, with the pilot valve 108 positioned between the hydraulic actuator 308 and the sequence valve 348). Similar to the relief valve 344, the downstream side of the sequence valve 348 can be coupled internally to the valve assembly, such as to the primary control valve 312 (see FIG. 6), or externally to the control valve assembly, such as to the tank 352 (see FIG. 7). Correspondingly, a second end of a control element (e.g, a high pressure reference) of the sequence valve 348 can be referenced to the hydraulic actuator 308 (e.g., via a connection between the pilot valve 108 and hydraulic actuator 308), while a first end of the control element (e.g., a low pressure reference) can be coupled to a spring 349 and referenced to a lower pressure connection. For example, in FIG. 6, the first end is referenced to the tank 352, while in FIG. 7, the first end is referenced to the atmosphere 356. Thus, below a threshold pressure of the hydraulic actuator 308, the force on the first end can overcome the force on the second end to bias the sequence valve 348 closed. Conversely, at or above the threshold pressure of the hydraulic actuator 308, the force on the second end can overcome the force on the first end to bias the sequence valve 348 open, which can also bias the second poppet 200 of the pilot valve 108 open and relieve pressure within the hydraulic actuator 308.

[0059] Similar arrangements of relief and sequence valves can be used to relieve pressure in other types of valve arrangement. In particular, such arrangements can be implemented in conjunction with the control valve assembly 100 illustrated in FIGS. 1 and 2 (e. ., with a high flow valve controlled by a pilot valve). For example, FIGS. 8-12 show a hydraulic system 400 (e.g., a valve system configured to provide thermal relief) that includes the control valve assembly 100, which is configured to control the hydraulic actuator 308. As illustrated, the first port 120 of the high-flow valve 104 is coupled to the load-holding side of the hydraulic actuator 308 and the second port 124 can be coupled to the primary control valve 312.

[0060] In some cases, the hydraulic circuit can include the relief valve 344, which can be coupled in parallel with the control valve assembly 100 to provide pressure relief for the hydraulic actuator 308. For example, in FIG. 8, the relief valve 344 is arranged similar to FIG. 3, with the upstream side of the relief valve 344 connected to the load-holding side 316 of the hydraulic actuator 308 (e.g., between the hydraulic actuator 308 and the first port 120), and the downstream side of the relief valve 344 connected to the primary control valve 312. The relief valve 344 can be a normally closed valve, with a first end of a flow control element (e.g., a spool) being coupled to the spring 345 and referenced to a downstream connection of the relief valve 344 (e.g, the primary control valve 312), while the second end of the flow control element is referenced to an upstream connection of the relief valve 344 (e.g., the load-holding side 316 of the hydraulic actuator 308). Accordingly, below a threshold pressure of the hydraulic actuator 308, the force on the first end can overcome the force on the second end to bias the relief valve 344 closed. Conversely, at or above the threshold pressure of the hydraulic actuator 308, the force on the second end can overcome the force on the first end to bias the relief valve 344 open and relieve pressure within the hydraulic actuator 308. Thus, the relief valve 344 can provide a relief path that may be independent of the pilot valve 108. It is appreciated that the primary control valve 312 may include an open connection to the tank 352 to allow fluid to drain through the relief valve 344.

[0061] In FIG. 9, the relief valve 344 is arranged similar to FIG. 4, with the upstream side of the relief valve 344 connected to the load-holding side 316 of the hydraulic actuator 308 (e.g., between the hydraulic actuator 308 and the first port 120), and the downstream side of the relief valve 344 connected directly to the tank 352. Accordingly, the relief valve 344 can be referenced directly to a tank 352 of the hydraulic system 300. In particular, the first end of the flow control element (e.g., a spool) can be coupled to the spring 345 and referenced to the tank 352, while a second end of the flow control element is referenced to the load-holding side 316 of the hydraulic actuator 308. Below a threshold pressure of the hydraulic actuator 308, the force on the first end can overcome the force on the second end to bias the relief valve 344 closed. Conversely, at or above the threshold pressure of the hydraulic actuator 308, the force on the second end can overcome the force on the first end to bias the relief valve 344 open and relieve pressure within the hydraulic actuator 308. Thus, fluid can be directed directly to the tank 352 from the relief valve 344 during an overpressure condition.

[0062] In FIG. 10, the relief valve 344 is arranged similar to FIG. 5, with the upstream side of the relief valve 344 connected to the load-holding side 316 of the hydraulic actuator 308 (e.g., between the hydraulic actuator 308 and the first port 120), and the downstream side of the relief valve 344 connected to the primary control valve 312. Accordingly, the relief valve 344 can be referenced to the atmosphere 356 as the low-pressure reference, such that the first end of the flow control element (e.g., a spool) can be coupled to the spring 345 and referenced to the atmosphere 356, and the second end of the flow control element is referenced to the load-holding side 316 of the hydraulic actuator 308. A filter or other vent 360 can be provided between the atmosphere and the first end of the flow control element of the relief valve 344. Thus, below a threshold pressure of the hydraulic actuator 308, the force on the first end can overcome the force on the second end to bias the relief valve 344 closed. Conversely, at or above the threshold pressure of the hydraulic actuator 308, the force on the second end can overcome the force on the first end to bias the relief valve 344 open and relieve pressure within the hydraulic actuator 308.

[0063] In other non-limiting examples, the hydraulic system 400 can include the sequence valve 348, which can be coupled in series with the control valve assembly 100 to provide pressure relief for the hydraulic actuator 308. For example, in FIG. 11, the sequence valve 348 is arranged similar to FIG. 6, with the upstream side of the sequence valve 348 coupled to the control chamber 130 (e.g., between the control chamber 130 and the pilot valve 108), and the downstream side of the sequence valve 348 coupled to the tank 352. The first end of the flow control element (e.g., a spool) can be coupled to the spring 349 and referenced to the tank 352, while the second end of the flow control element is referenced to the load-holding side 316 of the hydraulic actuator 308. Below a threshold pressure of the hydraulic actuator 308, the force on the first end can overcome the force on the second end to bias the sequence valve 348 closed. Conversely, at or above the threshold pressure of the hydraulic actuator 308, the force on the second end can overcome the force on the first end to bias the sequence valve 348 open and relieve pressure within the hydraulic actuator 308. Thus, fluid can be directed directly to the tank 352 from the sequence valve 348 during an overpressure condition.

[0064] In FIG. 12, the sequence valve 348 is arranged similar to FIG. 7, with the upstream side of the sequence valve 348 coupled to the control chamber 130 (e.g., between the control chamber 130 and the pilot valve 108), and the downstream side of the sequence valve 348 coupled to the primary control valve 312. Accordingly, the sequence valve 348 can be referenced to the atmosphere 356 as the low-pressure reference, such that the first end of the flow control element (e.g., a spool) can be coupled to the spring 349 and referenced to the atmosphere 356, and the second end of the flow control element is referenced to the load-holding side 316 of the hydraulic actuator 308. A filter or other vent 360 can be provided between the atmosphere and the first end of the flow control element of the sequence valve 348. Thus, below a threshold pressure of the hydraulic actuator 308, the force on the first end can overcome the force on the second end to bias the sequence valve 348 closed. Conversely, at or above the threshold pressure of the hydraulic actuator 308, the force on the second end can overcome the force on the first end to bias the sequence valve 348 open and relieve pressure within the hydraulic actuator 308.

[0065] Similar arrangements of control valves and pilot valves can be used to relieve pressure and to provide regenerative flow in other types of valve arrangements. In particular, such arrangements can be implemented in conjunction with regeneration valves to provide regenerative flow by coupling a load-holding side of a hydraulic actuator with a non-load-holding side of a hydraulic actuator such that fluid from the load-holding side is directed to the non-load-holding side during motion of the hydraulic actuator. For example, FIGS. 13-15 show a hydraulic system 500 (e.g., a valve system configured to provide load holding and hose burst protection) that includes the control valve assembly 100, which is configured to control the hydraulic actuator 308, and a regeneration pilot valve (RPV) 504, which is configured to provide regenerative flow in the hydraulic system 500. While relief and sequence valves are not shown in FIGS. 8-12, it is contemplated that such valves can also be coupled to the hydraulic system 500 (e.g., in parallel or in series with the main control valve 104 and/or the pilot valve 108), as generally described above with respect to FIGS. 3-12. As illustrated, the outlet 188 of the pilot valve 108 can be coupled to the load-holding side 316 of the hydraulic actuator 308.

[0066] In some cases, the hydraulic system 500 can include the RPV 504, which can be coupled in parallel with the control valve assembly 100 and/or the pilot valve 108 to provide pressure relief for the hydraulic actuator 308. In some examples, the RPV 504 can be positioned within the control valve assembly 100 (e.g., coupled to the pilot valve 108). For example, in FIG. 13, the RPV 504 is arranged in the hydraulic system 500 such that the upstream side of the RPV 504 can be coupled to the load-holding side 316 of the hydraulic actuator 308 (e.g., between the hydraulic actuator 308 and the inlet 184), and the downstream side of the RPV 504 can be coupled to the primary control valve 312 and the non-load-holding side 318 of the hydraulic actuator 308. In this way, an upstream side of the RPV 504 can be configured to receive fluid from the loadholding side 316 of the hydraulic actuator 308, and a downstream side of the RPV 504 can be configured to direct fluid to the non-load-holding side 318 of the hydraulic actuator 308 or the primary control valve 312. In addition, a check valve 508 can be coupled downstream of the RPV 504 (i.e., between the RPV 504 and the non-load-holding side 318 of the hydraulic actuator 308. The check valve 508 may permit unidirectional flow from the RPV 504 downstream, meaning that the check valve 508 can block fluid flowing upstream from the non-load-holding side 318 to the RPV 504. Thus, the RPV 504 can provide a fluid communication path between the load-holding side 316 and the non-load-holding side 318 of the hydraulic actuator 308 that may be independent of the pilot valve 108. In some examples, the RPV 504 can be a selectively opened and closed in response to commands from a control system or algorithm, which may also operate the control valve assembly 100. For example, the RPV 504 can be selectively opened to allow hydraulic actuator 308 fluid to flow from the load-holding side 316 to the non-load-holding side 318 of the hydraulic actuator 308 during an upstroke of the hydraulic actuator 308, which in turn can increase the stroke speed of the hydraulic actuator 308. During a downstroke of the hydraulic actuator 308, the fluid in the non-load-holding side 318 can then be directed to the primary control valve 312, and the process can be repeated. This regenerative flow of fluid to the non-load-holding side 318 of the hydraulic actuator 308 reduces the amount of flow needed from the control valve assembly 100, which increases the efficiency of the system by increasing the stroke speed of the hydraulic actuator 308 and/or consuming less energy used to generate pump flow through the control valve assembly 100.

[0067] In FIG. 14, the hydraulic system 500 further includes the high-flow valve 104 coupled to the pilot valve 108 (i.e., the control valve assembly 100 of FIG. 1) as discussed above. In particular, the first port 120 can be coupled to the load-holding side 316 of the hydraulic actuator 308 and an upstream side of the RPV 504, and the second port 124 can be coupled to the pilot valve 108 and the primary control valve 312. As discussed above, an upstream side of the RPV 504 can be configured to receive fluid from the load-holding side 316 of the hydraulic actuator 308, and a downstream side of the RPV 504 can be configured to direct fluid to the non-loadholding side 318 of the hydraulic actuator 308 or the primary control valve 312 during, for example, an upstroke of the hydraulic actuator 308. In some examples, the check valve 508 can be arranged within the RPV 504 (e.g., in a poppet in the pilot valve 108), or the check valve 508 can be arranged downstream of the RPV 504 (e.g., between the RPV 504 and the non-load-holding side 318 of the hydraulic actuator 308). Accordingly, the RPV 504 can be configured to provide metered regenerative flow to the non-load-holding side 318 of the hydraulic actuator 308 to increase the stroke speed of the hydraulic actuator 308 or reduce the flow required from the primary control valve 312 to fill the non-load-holding side 318 of the hydraulic actuator 308.

[0068] In FIG. 15, the hydraulic system 500 further includes a regeneration control valve (RCV) 512 coupled to the RPV 504. In particular, the RPV 504 and the RCV 512 can be positioned between the control valve assembly 100 with the upstream side of the RCV 512 coupled to the load-holding side 316 of the hydraulic actuator 308 (e.g., between the hydraulic actuator 308 and the first port 120), and the downstream side of the RCV 512 coupled directly to the non-loadholding side 318 of the hydraulic actuator 308 and the tank 352. In this way, an upstream side of the RCV 512 can be configured to receive fluid from the load-holding side 316 of the hydraulic actuator 308, and a downstream side of the RPV 504 can be configured to direct fluid to the nonload-holding side 318 of the hydraulic actuator 308 or the primary control valve 312 during, for example, an upstroke of the hydraulic actuator 308. In some examples, the check valve 508 can be arranged within the RPV 504 (e.g., in a poppet in the pilot valve 108), or the check valve 508 can be arranged downstream of the RPV 504 (e.g., between the RPV 504 and the non-load-holding side 318 of the hydraulic actuator 308). Similar to the control valve assembly 100, the RPV 504 and the RCV 512 may be configured to meter fluid through the hydraulic system 500 and further provide metered regenerative flow to the non-load-holding side 318 of the hydraulic actuator 308 to increase the stroke speed of the hydraulic actuator 308.

[0069] Thus, it is an advantage of the present disclosure that a regenerative valve can be used in a control valve assembly to reduce the amount of fluid that has to be pumped into the hydraulic system to move the hydraulic actuator. Put another way, a smaller or less powerful pump may be used in a hydraulic system with a regenerative valve, and/pr a pump that is used with a regenerative valve in a hydraulic system can create faster hydraulic actuator speeds. Accordingly, using regeneration valves can decrease operation costs and lead to a more efficient hydraulic system.

[0070] Within this specification embodiments have been described in a way which enables a clear and concise specification to be written, but it is intended and will be appreciated that embodiments may be variously combined or separated without parting from the invention. For example, it will be appreciated that all preferred features described herein are applicable to all aspects of the invention described herein.

[0071] Thus, while the invention has been described in connection with particular embodiments and examples, the invention is not necessarily so limited, and that numerous other embodiments, examples, uses, modifications and departures from the embodiments, examples and uses are intended to be encompassed by the claims attached hereto. The entire disclosure of each patent and publication cited herein is incorporated by reference, as if each such patent or publication were individually incorporated by reference herein.

[0072] Various features and advantages of the invention are set forth in the following claims.