US-12618424-B2 - Hydraulic control system and method with electro-proportional pressure valve and integral check

US12618424B2US 12618424 B2US12618424 B2US 12618424B2US-12618424-B2

Abstract

A hydraulic control assembly includes means for holding pressure in a cylinder to inhibit boom or arm drop of a machine in the event that a hose between the cylinder and a main control valve (MCV) ruptures. The pressure holding means of the hydraulic control assembly include a hydraulic valve and a parts-in-body check assembly both configured for insertion into a valve cavity defined by a valve body. The hydraulic valve comprises a proportional piloted valve that controls pressure.

Inventors

Travis Schmidt
Valeriy Kazak
Brian Del Bene

Assignees

HYDRAFORCE, INC.

Dates

Publication Date: 20260505
Application Date: 20240409

Claims (4)

1 . A method of controlling a hydraulic circuit, the hydraulic circuit including a pump, a main control valve (MCV), a body, a hydraulic valve, a check assembly, a housing, a pilot poppet, a cylinder, and a tank, wherein: the body defines a valve cavity, a first port, a second port, and a third port, each of the first port, the second port, and the third port being in fluid communication with the valve cavity, the first port being fluidly connected to the cylinder, the second port being fluidly connected to the MCV through which the second port is fluidly connected to a source of hydraulic fluid from the pump, and the third port being fluidly connected to the tank, the hydraulic valve being mounted to the body such that the hydraulic valve is at least partially disposed within the valve cavity, the hydraulic valve comprises an electro-proportional pressure valve and has a nose, and the check assembly is disposed within the valve cavity and is in abutting relationship with the hydraulic valve such that the check assembly is seated against the nose of the hydraulic valve, wherein the check assembly is configured to permit a flow of hydraulic fluid from the second port to the first port through the check assembly and to prevent the flow of hydraulic fluid from the first port to the second port through the check assembly, the housing fixed within the valve cavity of the body, the housing including a longitudinal passageway having an interior opening and an external opening, the longitudinal passageway being in communication with a transverse pilot passageway and a longitudinal bore, and the housing including a pilot seat circumscribing the interior opening of the longitudinal passageway, and the pilot poppet moveably disposed within the longitudinal bore of the housing, the pilot poppet adapted to sealingly engage the pilot seat, the method comprising: performing a lifting operation in which a flow of pressurized hydraulic fluid is conveyed from the second port to the first port through the check assembly; maintaining a coil of the hydraulic valve in a de-energized condition during the lifting operation.
2 . The method of claim 1 , further comprising: performing a lowering operation in which a flow of hydraulic fluid is conveyed from the first port to the second port through the hydraulic control valve; energizing the coil of the hydraulic valve during the lowering operation to proportionally reduce the effective force exerted by a main spring of the hydraulic cartridge valve.
3 . The method of claim 1 , further comprising: blocking, when a loss of hydraulic fluid in the hydraulic circuit occurs, the flow of hydraulic fluid from the cylinder to maintain the load in position by preventing the flow of hydraulic fluid from the first port to the second port through the check assembly.
4 . The method of claim 3 , further comprising: performing a pressure relieving operation when the pressure in the cylinder exceeds a predetermined limit in which hydraulic fluid is conveyed from the cylinder via the first port to the third port through the hydraulic valve by moving a movable member of the hydraulic valve by overcoming a force of a main spring of the hydraulic valve.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS This patent application is a continuation of U.S. patent application Ser. No. 17/179,130, filed Feb. 18, 2021, and entitled, “Hydraulic Control System and Method with Electro-Proportional Pressure Valve and Integral Check,” which, in turn, claims the benefit of priority to U.S. Provisional Patent Application No. 62/978,053, filed Feb. 18, 2020, and entitled, “Electro-Proportional Pressure Valve with Integral Check and Hydraulic Control System and Method,” which are incorporated in their entirety herein by this reference. TECHNICAL FIELD This patent disclosure relates generally to a hydraulic valve and, more particularly, to a hydraulic control assembly with an electro-proportional pressure valve and an integral check safety feature in the event of a loss in hydraulic fluid, such as when a hose ruptures or bursts. BACKGROUND Machines such, as excavators and backhoe loaders, typically include a lifting linkage comprising an assembly of parts (e.g., a combination of a boom and an arm) used for raising and lowering a lift point for use in an object handling process. The machine can include a linkage control system comprising a hydraulic circuit having a plurality of hydraulic control components used for raising and lowering the lift point in object handling applications. When such machines are used for object handling, a failure or rupture in the hydraulic circuit could endanger persons under raised loads and could damage the lifting linkage. These risks can be reduced by applying a lowering control device for controlled lowering of the load in the case of a hydraulic line failure or rupture. Conventional solutions use a pilot-operated proportional poppet that controls the flow between the boom and the main control valve. The proportional poppet is controlled via remote pilot pressure that can come from either a pilot-operated joystick or an electro-proportional pressure reducing/relieving valve. In some cases, the electro-proportional valve is integrated with the proportional poppet into one casting or manifold, but a separate component within the assembly. There is a continued need in the art to provide additional solutions to enhance the use and safety of hydraulic circuits over a range of conditions. For example, there is a continued need for techniques for maintaining a load in position and/or for controlled lowering of the load in the event that there is a loss of hydraulic fluid in the circuit, such as, in the case of a hydraulic line failure or rupture. It will be appreciated that this background description has been created by the inventors to aid the reader, and is not to be taken as an indication that any of the indicated problems were themselves appreciated in the art. While the described principles can, in some aspects and embodiments, alleviate the problems inherent in other systems, it will be appreciated that the scope of the protected innovation is defined by the attached claims, and not by the ability of any disclosed feature to solve any specific problem noted herein. SUMMARY The present disclosure, in one aspect, is directed to embodiments of a hydraulic control assembly. In embodiments, a hydraulic control assembly includes means for holding pressure in a cylinder to inhibit boom or arm drop of a machine in the event that a hose between the cylinder and a main control valve (MCV) ruptures. In one embodiment, a hydraulic control assembly includes a body, a hydraulic valve, and a check assembly. The body defines a valve cavity, a first port, a second port, and a third port. Each of the first port, the second port, and the third port are in fluid communication with the valve cavity. The first port is adapted to be fluidly connected to a cylinder of a hydraulic circuit, the second port is adapted to be fluidly connected to a main control valve (MCV) of the hydraulic circuit through which the second port is fluidly connected to a source of hydraulic fluid, and the third port is adapted to be fluidly connected to a tank of the hydraulic circuit. The hydraulic valve is mounted to the body such that the hydraulic valve is at least partially disposed within the valve cavity. The hydraulic valve comprises an electro-proportional pressure valve and has a nose. The check assembly is disposed within the valve cavity and in abutting relationship with the hydraulic valve such that the check assembly is seated against the nose of the hydraulic valve. The check assembly is configured to permit a flow of hydraulic fluid from the second port to the first port through the check assembly and to prevent the flow of hydraulic fluid from the first port to the second port through the check assembly. The hydraulic valve is configured to permit the flow of hydraulic fluid from the first port to the second port through the hydraulic valve once a load pressure at the first port exceeds a threshold pressure and to block the flow of hydraulic fluid from the first port to the second